Efeito de extratos vegetais de Hamamelis virginiana, Persea americana, Cynara scolymus L e Stryphnodendron barbatiman Msobre a expressão fenotípica dos fatores de virulência em biofilmes de Candida albicans / Effect of Hamamelis virginiana, Persea americana, Cynara scolymus L and Stryphnodendron barbatiman M plant extracts on the phenotypic expression of virulence factors in biofilms of the Candida albicans

Objetivo: Analisar a expressão fenotípica de fatores de virulência em biofilmes de Candida albicans frente a extratos glicólicos de plantas. Material e Métodos: Os biofilmes de Candida albicans (ATCC 18804) obtidos a partir de incubação de 48 horas foram expostos por 5 minutos e 24 horas a diferentes concentrações de extratos glicólicos de Hamamelis virginiana e Persea americana, Cynara scolymus L e Stryphnodendron barbatiman M, a fim de verificar a ação antifúngica da proteinase, fosfolipase e hemolisina. Resultados: Todos os extratos foram eficazes na redução do biofilme. Em contato por 5 minutos. os extratos reduziram 50% do biofilme. Após 24 horas. o extrato de Persea americana apresentou o biofilme em 90%, seguido de Cynara scolymus, que o interrompeu em 85%. Houve mudança na intensidade da proteinase após 5 minutos e 24 horas, com uma atividade enzimática média de 0,69 em comparação com o controle de 0,49. Cynara scolymus foi o extrato com maior concentração média de 100 mg/ml; a intensidade da fosfolipase foi alterada com Stryphnodendron barbatiman sendo mais efetivo em 24 horas em relação ao controle (p< 0,0001). A secreção de hemolisina foi modificada por Hamamelis virginiana (12,5 mg/ml) após 5 minutos de exposição e em 24 horas. todos os extratos foram capazes de causar alterações na secreção. Conclusão: Os extratos testados apresentam potencial antifúngico em biofilmes de Candida albicans, implicando em redução significativa dos fatores de virulência. Assim, estes podem ser indicados como uma ferramenta terapêutica alternativa para reduzir a morbidade dessas infecções, já que em ambos os tempos de exposição investigados, eles foram capazes de reduzir a secreção enzimática do fungo (AU)

Objective: Analyze the phenotypic expression of virulence factors in Candida albicans biofilms against plant glycolicextracts. Material and Methods: The biofilms of Candida albicans (ATCC 18804) obtained from incubation for 48 hours were exposed for 5 minutes and 24 hours to different concentrations of glycolic extracts of Hamamelis virginiana and Persea americana, Cynara scolymus L and Stryphnodendron barbatiman M, in order to verify the antifungal activity of the proteinase, phospholipase and hemolysin. Results: All extracts were effective in reducing biofilm. In contact for 5 minutes. the extracts reduced 50% of the biofilm. After 24 hours, the Persea americanaextract showed the biofilm at 90%, followed by Cynara scolymus, which interrupted it at 85%, There was a change in proteinase intensity after 5 minutes and 24 hours. with an average enzymatic activity of 0.69 compared to the control of 0.49. Cynara scolymus was the extract with the highest mean concentration of 100 mg/ml; the phospholipase intensity was changed with Stryphnodendron barbatiman being more effective in 24 hours compared to the control (p< 0.0001). The hemolysin secretion was modified by Hamamelis virginiana (12.5 mg/ml) after 5 minutes of exposure, and in 24 hours. all extracts were capable to cause changes in secretion. Conclusion: The tested extracts have antifungal potential in Candida albicans biofilms, implying a significant reduction in virulence factors. Thus, these can be indicated as an alternative therapeutic tool to reduce the morbidity of these infections, as in both investigated exposure times. they were able to reduce theenzymatic secretion of the fungus (AU)

Antifungal activity of 2-chloro-N-phenylacetamide: a new molecule with fungicidal and antibiofilm activity against fluconazole-resistant Candida spp / Atividade antifúngica de 2-cloro-N-fenilacetamida: uma nova molécula com atividade fungicida e anti-biofilme contra Candida spp. resistentes a fluconazol

In the current context of emerging drug-resistant fungal pathogens such as Candida albicans and Candida parapsilosis, discovery of new antifungal agents is an urgent matter. This research aimed to evaluate the antifungal potential of 2-chloro-N-phenylacetamide against fluconazole-resistant clinical strains of C. albicans and C. parapsilosis. The antifungal activity of 2-chloro-N-phenylacetamide was evaluated in vitro by the determination of the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), inhibition of biofilm formation and its rupture, sorbitol and ergosterol assays, and association between this molecule and common antifungal drugs, amphotericin B and fluconazole. The test product inhibited all strains of C. albicans and C. parapsilosis, with a MIC ranging from 128 to 256 µg.mL-1, and a MFC of 512-1,024 µg.mL-1. It also inhibited up to 92% of biofilm formation and rupture of up to 87% of preformed biofilm. 2-chloro-N-phenylacetamide did not promote antifungal activity through binding to cellular membrane ergosterol nor it damages the fungal cell wall. Antagonism was observed when combining this substance with amphotericin B and fluconazole. The substance exhibited significant antifungal activity by inhibiting both planktonic cells and biofilm of fluconazole-resistant strains. Its combination with other antifungals should be avoided and its mechanism of action remains to be established.

No atual contexto de patógenos fúngicos resistentes emergentes tais como Candida albicans e Candida parapsilosis, a descoberta de novos agentes antifúngicos é uma questão urgente. Esta pesquisa teve como objetivo avaliar o potencial antifúngico da 2-cloro-N-fenilacetamida contra cepas clínicas de C. albicans e C. parapsilosis resistentes a fluconazol. A atividade antifúngica da substância foi avaliada in vitro através da determinação da concentração inibitória mínima (CIM), concentração fungicida mínima (CFM), ruptura e inibição da formação de biofilme, ensaios de sorbitol e ergosterol, e associação entre esta molécula e antifúngicos comuns, anfotericina B e fluconazol. O produto teste inibiu todas as cepas de C. albicans e C. parapsilosis, com uma CIM variando de 128 a 256 µg.mL-1, e uma CFM de 512-1,024 µg.mL-1. Também inibiu até 92% da formação de biofilme e causou a ruptura de até 87% de biofilme pré-formado. A 2-cloro-N-fenilacetamida não promoveu atividade antifúngica pela ligação ao ergosterol da membrana celular fúngica, tampouco danificou a parede celular. Antagonismo foi observado ao combinar esta substância com anfotericina B e fluconazol. A substância exibiu atividade antifúngica significativa ao inibir tanto as células planctônicas quanto o biofilme das cepas resistentes ao fluconazol. Sua combinação com outros antifúngicos deve ser evitada e seu mecanismo de ação deve ser estabelecido.

Comparative in vitro analysis of the antifungal activity of different calcium silicate-based endodontic sealers

Aim: This study aimed to perform an in vitro comparative analysis of the antifungal activity of different calcium silicate-based endodontic sealers against three fungal species. Methods: The antifungal properties of three calcium silicate-based sealers were tested: Bio-C Sealer, Cambiar a Sealer Plus BC, and MTA-Fillapex. Two commonly used sealers were used as controls: AH Plus and Endomethasone. An agar diffusion test was performed to analyze the antifungal activity of the sealers against Candida albicans, Candida glabrata, Candida tropicalis, and a mixed microbial culture medium. The results were analyzed using ANOVA (p <0.05). Results: Endomethasone exhibited the highest inhibition against all strains examined, maintaining a consistent level of inhibition throughout 7 days. MTA-Fillapex demonstrated the best performance among the calcium silicate-based sealers for the three fungal species (p < 0.05), maintaining stable values over the 7 days, surpassing that of Endomethasone. Nevertheless, MTA-Fillapex only exhibited antimicrobial effect against the mixed culture for the first 24 hours, and no antimicrobial activity was observed at 48 hours, being surpassed by all tested sealers (p < 0.05). Conclusion: Of all silicate-based sealers tested, only MTA-Fillapex exhibited promising antifungal activity. Nevertheless, care must be taken when extrapolating these results, as MTA-Fillapex exhibited poor antimicrobial activity when tested in mixed microbial cultures

Atividade antifúngica de nanofibras de policaprolactona/nistatina: estudo in vitro e in vivo / Antifungal activity of polycaprolactone/nystatin nanofibers: in vitro and in vivo study

Este estudo avaliou a eficácia in vitro e in vivo de mantas de nanofibras (NF) de policaprolactona (PCL) incorporadas com nistatina (NIS) no tratamento da estomatite protética (EP) em modelos animais. NF foram sintetizadas com diferentes concentrações de NIS, totalizando quatro soluções: PCL puro, PCL/NIS 0,045 g, PCL/NIS 0,090 g e PCL/NIS 0,225 g. A liberação da NIS foi analisada por espectroscopia Ultravioleta-Visível. A capacidade das mantas de inibirem o biofilme de Candida albicans, principal fator etiológico da EP, dividindo-se cinco grupos (N=5) compostos por um grupo com controle de células de C. albicans e com PCL puro, além das três concentrações de NIS. A seguir, foi analisada a viabilidade celular em queratinócitos humanos (HaCat) por meio do teste colorimétrico de resazurina. Cinco grupos foram divididos (N=10): controle celular, PCL puro e as três concentrações de NIS. Em modelos animais de ratos Wistar albinos (N=18), dispositivos palatinos (DP) de resina acrílica foram confeccionados simulando próteses totais e utilizados para a indução da EP. Para isso, DP contaminados com C. albicans foram cimentados na região molar da cavidade bucal dos animais e permaneceram em boca por 48 h. Após esse período, os DP foram removidos e os animais foram divididos em três grupos: (C) controle; (B1) com tratamento por mantas de PCL/NIS 0,045 g e (B2) PCL/NIS 0,225 g, com N=6. Então novos DP, livres de contaminação, foram cimentados na cavidade oral dos animais e permaneceu por mais 48 h. Após esse período, os animais foram eutanasiados, a contagem de UFC/ mL foi realizada e os palatos foram coletados para a análise histológica. A curva padrão de NIS obtida apresentou R2 de 0,99. As três concentrações de NF apresentaram liberação de NIS, com pico no tempo de 6 h e valores de 66,26 µg/ mL para PCL/NIS 0,045 g, de 333,87 µg/ mL para PCL/NIS 0,090 g e 436,51 µg/ mL para PCL/NIS 0,225 g, constantes até o fim do experimento. Os grupos com NIS reduziram em 2,5 log10 de crescimento do biofilme fúngico em relação aos grupos sem tratamento, Controle e PCL, sem diferença estatística significativa. Não foi observada citotoxicidade nas células HaCat, com viabilidade celular de 93,7% para PCL/NIS 0,045 g, 72,6% para PCL/NIS 0,090 g e 72,4% para PCL/NIS 0,225 g. A indução da EP nos três grupos foi possível e, porém, sem redução significativa na contagem de UFC/ mL de C. albicans nos grupos B1 e B2. Na análise histológica do grupo C pôde-se observar infiltração de hifas de Candida na camada queratinizada, presença de células inflamatórias formando micro abscessos e um discreto infiltrado inflamatório no tecido conjuntivo subjacente ao epitélio infectado. Nos grupos B1 e B2 não foram encontradas alterações epiteliais, concluindo-se que as NF demonstraram atividade antifúngica in vitro e foram efetivas na prevenção da penetração de hifas no tecido palatino de animais com DP (AU)

This study evaluated the in vitro and in vivo efficacy of nanofiber (NF) mats of polycaprolactone (PCL) incorporated with nystatin (NIS) in the treatment of denture stomatitis (DS) in animal models. NFs were synthesized with different concentrations of NIS, totaling four solutions: pure PCL, PCL/NIS 0.045 g, PCL/NIS 0.090 g, and PCL/NIS 0.225 g. The release of NIS was analyzed by Ultraviolet-Visible spectroscopy. The ability of the mats to inhibit Candida albicans biofilm, the main etiological factor of DS, was assessed by dividing five groups (N=5) composed of a group with C. albicans cell control and with pure PCL, in addition to the three concentrations of NIS. Next, cell viability in human keratinocytes (HaCat) was analyzed using the resazurin colorimetric test. Five groups were divided (N=10): cell control, pure PCL, and the three concentrations of NIS. In albino Wistar rat animal models (N=18), palatal devices (PD) made of acrylic resin were fabricated to simulate total prostheses and used to induce DS. For this, PD contaminated with C. albicans were cemented in the molar region of the animals' oral cavity and remained in the mouth for 48 hours. After this period, the PDs were removed, and the animals were divided into three groups: (C) control; (B1) treated with PCL/NIS 0.045 g mats, and (B2) PCL/NIS 0.225 g, with N=6. Then new, uncontaminated PDs were cemented in the animals' oral cavity and remained for another 48 hours. After this period, the animals were euthanized, UFC/ mL counts were performed, and the palates were collected for histological analysis. The standard NIS curve obtained showed an R2 of 0.99. The three concentrations of NF showed NIS release, with a peak at 6 h and values of 66.26 µg/ mL for PCL/NIS 0.045 g, 333.87 µg/ mL for PCL/NIS 0.090 g, and 436.51 µg/ mL for PCL/NIS 0.225 g, remaining constant until the end of the experiment. The groups with NIS reduced fungal biofilm growth by 2.5 log10 compared to the untreated groups, Control and PCL, with no significant statistical difference. No cytotoxicity was observed in HaCat cells, with cell viability of 93.7% for PCL/NIS 0.045 g, 72.6% for PCL/NIS 0.090 g, and 72.4% for PCL/NIS 0.225 g. Induction of DS in the three groups was possible; however, there was no significant reduction in UFC/ mL counts of C. albicans in groups B1 and B2. Histological analysis of group C revealed infiltration of Candida hyphae in the keratinized layer, presence of inflammatory cells forming micro abscesses, and a discreet inflammatory infiltrate in the connective tissue underlying the infected epithelium. No epithelial alterations were found in groups B1 and B2, concluding that NFs demonstrated in vitro antifungal activity and were effective in preventing hyphal penetration into palatal tissue in animals with PD.(AU)

Antifungal activity of 2-chloro-N-phenylacetamide: a new molecule with fungicidal and antibiofilm activity against fluconazole-resistant Candida spp

Abstract In the current context of emerging drug-resistant fungal pathogens such as Candida albicans and Candida parapsilosis, discovery of new antifungal agents is an urgent matter. This research aimed to evaluate the antifungal potential of 2-chloro-N-phenylacetamide against fluconazole-resistant clinical strains of C. albicans and C. parapsilosis. The antifungal activity of 2-chloro-N-phenylacetamide was evaluated in vitro by the determination of the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), inhibition of biofilm formation and its rupture, sorbitol and ergosterol assays, and association between this molecule and common antifungal drugs, amphotericin B and fluconazole. The test product inhibited all strains of C. albicans and C. parapsilosis, with a MIC ranging from 128 to 256 µg.mL-1, and a MFC of 512-1,024 µg.mL-1. It also inhibited up to 92% of biofilm formation and rupture of up to 87% of preformed biofilm. 2-chloro-N-phenylacetamide did not promote antifungal activity through binding to cellular membrane ergosterol nor it damages the fungal cell wall. Antagonism was observed when combining this substance with amphotericin B and fluconazole. The substance exhibited significant antifungal activity by inhibiting both planktonic cells and biofilm of fluconazole-resistant strains. Its combination with other antifungals should be avoided and its mechanism of action remains to be established.

Resumo No atual contexto de patógenos fúngicos resistentes emergentes tais como Candida albicans e Candida parapsilosis, a descoberta de novos agentes antifúngicos é uma questão urgente. Esta pesquisa teve como objetivo avaliar o potencial antifúngico da 2-cloro-N-fenilacetamida contra cepas clínicas de C. albicans e C. parapsilosis resistentes a fluconazol. A atividade antifúngica da substância foi avaliada in vitro através da determinação da concentração inibitória mínima (CIM), concentração fungicida mínima (CFM), ruptura e inibição da formação de biofilme, ensaios de sorbitol e ergosterol, e associação entre esta molécula e antifúngicos comuns, anfotericina B e fluconazol. O produto teste inibiu todas as cepas de C. albicans e C. parapsilosis, com uma CIM variando de 128 a 256 µg.mL-1, e uma CFM de 512-1,024 µg.mL-1. Também inibiu até 92% da formação de biofilme e causou a ruptura de até 87% de biofilme pré-formado. A 2-cloro-N-fenilacetamida não promoveu atividade antifúngica pela ligação ao ergosterol da membrana celular fúngica, tampouco danificou a parede celular. Antagonismo foi observado ao combinar esta substância com anfotericina B e fluconazol. A substância exibiu atividade antifúngica significativa ao inibir tanto as células planctônicas quanto o biofilme das cepas resistentes ao fluconazol. Sua combinação com outros antifúngicos deve ser evitada e seu mecanismo de ação deve ser estabelecido.

Abscesos renales bilaterales multifocales por Candida albicans / Bilateral multifocal kidney abscess due to Candida al bicans

Resumen Los abscesos renales son una complicación poco frecuente de las infecciones del tracto urinario y suelen asociarse con un aumento de la morbi-mortalidad. La mayoría de los casos ocurre en pacientes con factores predisponentes como la inmunosupresión. El diagnóstico requiere de una elevada sospecha clínica y el trata miento consiste en el uso de antibióticos y antifúngicos parenterales asociados o no a intervenciones quirúrgicas como nefrostomía y nefrectomía. Son pocos los casos publicados en la literatura médi ca de abscesos renales bilaterales multifocales y menos aún por Candida albicans. Se presenta el caso de una mujer de 20 años de edad con diabetes mellitus tipo 1 diagnosticada a los 8 años, múltiples internaciones por cetoacidosis diabética y reciente internación por can didemia (Candida albicans) completando tratamiento con fluconazol por 23 días. A los 18 días de su externación, consulta por dolor en flancos de tipo sordo y síntomas ge nerales; se realizó tomografía de abdomen con contraste que mostró abscesos multifocales bilaterales. Aislándose Candida albicans en una de las muestras obtenidas de las lesiones; recibió tratamiento con fluconazol 400 mg por 6 semanas endovenoso y 2 semanas vía enteral, evolu cionando favorablemente con mejoría clínica e image nológica continuando seguimiento clínico ambulatorio. Este reporte resalta la importancia del diagnóstico y tratamiento de esta complicación infrecuente en enfer medades complejas como la diabetes.

Abstract Renal abscesses are a rare complication of urinary tract infections and may be associated with increased morbidity and mortality. Most cases occur in patients with predisposing factors such as immunosuppression. Diagnosis requires high clinical suspicion and its treat ment consists in the use of parenteral antibiotics and antifungals associated or not with surgical interventions such as nephrostomy and nephrectomy. Few cases have been published in the medical literature of multifocal bilateral renal abscesses and even fewer due to Candida albicans. We present the case of a 20-year-old woman with type 1 diabetes mellitus, diagnosed at age 8, multiple hospitalizations for diabetic ketoacidosis, and recent hospitalization for candidemia (Candida albicans) treated with fluconazole for 23 days. Eighteen days after her discharge, she consulted for dull flank pain and gen eral symptoms. Contrast enhanced abdominal tomography showed bilateral multifocal abscesses and Candida albicans was isolated in one of the samples obtained from lesions. She received fluconazole 400 mg, 6 weeks i.v. and 2 weeks via enteral route, evolving favorably with clinical and imag ing improvement, continuing outpatient clinical monitoring. This report highlights the importance of diagnosis and treatment of this rare complication in complex diseases such as diabetes mellitus.

Impact on the clinical evolution of patients with COVID-19 from an Intensive Care Unit with isolation of Candida spp. in respiratory samples / Impacto na evolução clínica de pacientes com COVID-19 de uma Unidade de Terapia Intensiva com isolamento de Candida spp. em amostras respiratórias / Impacto en la evolución clínica de pacientes con COVID-19 de una Unidad de Cuidados Intensivos con aislamiento de Candida spp. en muestras respiratorias

Background and Objectives: several patients with COVID-19 require hospital admission due to severe respiratory complications and undergo intensive care with mechanical ventilation (MV) support. Associated with this situation, there is an increase in fungal co-infections, which has a negative impact on the outcome of COVID-19. In this regard, this study intended to compare Candida spp. incidence in the respiratory tract of patients admitted in the COVID and General Intensive Care Units (ICU) at a teaching hospital in 2021. Methods: the results of protected tracheal aspirate samples from 556 patients admitted to the COVID ICU and 260 to General ICU as well as the respective records. Results: of the patients analyzed, 38 revealed a positive sample for Candida in the COVID ICU and 10 in the General ICU, with an incidence of 68.3/1000 and 38.5/1000, respectively. Males were predominant in both wards. The most affected age group was the population over 60 years old, and the average hospital admission for the COVID ICU was 22.1 years, and for the General ICU, 24.2. Conclusion: Candida albicans was the most frequently isolated species, and the mortality rate in patients positive for Candida was higher in patients with COVID-19 compared to patients in the General ICU, suggesting that patients infected with SARS-CoV-2, admitted to the ICU under MV, are more predisposed to colonization by Candida spp., which can have a fatal outcome in these patients.(AU)

Justificativa e objetivos: muitos pacientes com COVID-19 necessitam de hospitalização devido às complicações respiratórias graves, e são submetidos a cuidados intensivos com suporte de ventilação mecânica (VM). Associado a esse quadro, verifica-se o aumento de coinfecções fúngicas, que tem impacto negativo no desfecho da COVID-19. Nesse sentido, este estudo pretendeu comparar a incidência de Candida spp. no trato respiratório de pacientes internados nas Unidades de Terapia Intensiva (UTI) COVID e Geral em um hospital escola em 2021. Métodos: foram avaliados os resultados de amostras de aspirado traqueal protegido provenientes de 556 pacientes internados na UTI COVID e 260 na UTI Geral, bem como os respectivos prontuários. Resultados: dos pacientes analisados, 38 revelaram amostra positiva para Candida na UTI COVID e 10 na UTI Geral, com incidência de 68,3/1000 e 38,5/1000, respectivamente. O sexo masculino foi predominante em ambas as alas. A faixa etária mais acometida foi a população acima de 60 anos, e a média de internação para a UTI COVID foi de 22,1 anos, e para a UTI Geral, 24,2. Conclusão: Candida albicans foi a espécie isolada com maior frequência, e a taxa de mortalidade em pacientes com positivos para Candida foi maior em pacientes com COVID-19 em relação aos pacientes da UTI Geral, sugerindo que pacientes infectados com SARS-CoV-2, internados em UTI sob VM, são mais predispostos à colonização por Candida spp., que pode ter um desfecho fatal nesses pacientes.(AU)

Justificación y objetivos: muchos pacientes con COVID-19 requieren hospitalización debido a complicaciones respiratorias graves y se someten a cuidados intensivos con soporte de ventilación mecánica (VM). Asociado a esta situación, hay un aumento de las coinfecciones fúngicas, lo que repercute negativamente en el desenlace de la COVID-19. En este sentido, este estudio pretendió comparar la incidencia de Candida spp. en el tracto respiratorio de pacientes ingresados en las Unidades de Cuidados Intensivos (UCI) COVID y General de un hospital escuela en 2021. Métodos: los resultados de muestras de aspirado traqueal protegidas de 556 pacientes ingresados en la UCI COVID y 260 en el UCI General, así como los respectivos registros. Resultados: de los pacientes analizados, 38 presentaron muestra positiva a Candida en UCI COVID y 10 en UCI General, con una incidencia de 68,3/1000 y 38,5/1000, respectivamente. Los machos predominaban en ambas alas. El grupo de edad más afectado fue la población mayor de 60 años, y la hospitalización promedio en la UCI COVID fue de 22,1 años, y en la UCI General, de 24,2. Conclusiones: Candida albicans fue la especie aislada con mayor frecuencia, y la tasa de mortalidad en pacientes positivos para Candida fue mayor en pacientes con COVID-19 en comparación con los pacientes en la UCI General, lo que sugiere que los pacientes infectados con SARS-CoV-2, ingresados en la UCI bajo VM, están más predispuestos a la colonización por Candida spp., lo que puede tener un desenlace fatal en estos pacientes.(AU)

gDNA extraction from Candida albicans and Candida dubliniensis in subgingival samples in Argentina. Evaluation of different methods / Evaluación de diferentes métodos de extracción de gADN en Candida albicans y Candida dubliniensis en muestras subgingivales en Argentina

ABSTRACT The oral cavity constitutes a unique ecosystem with highly variable ecological niches that harbor a great variety of microorganisms, including yeasts. Molecular methods are currently considered the gold standard for identifying species, although they involve limitations associated with the disruption of yeast cell walls to release the genomic DNA (gDNA) for amplification. Aim: The aim of this study was to compare the performance of different methods for extracting gDNA from Candida albicans and Candida dubliniensis, subsequently amplifying DNA by PCR. Materials and Method: Fifty-two isolates (16 C. albicans and 36 C. dubliniensis) were obtained from subgingival biofilm of HIV+ patients with clinical signs of periodontal disease. The study evaluated 6 gDNA extraction methods and two PCR amplification methods. Furthermore, the presence of alleles of HWP1 gene was determined in C. albicans. Results: Comparisons of six methods show statistically significant differences (p<0.001) except for C. albicans in two of them. For C. dubliniensis, statistical differences were observed in all comparisons. Commercial methods were more efficient for concentrating gDNA than in-house methods, and both PCRs were effective. Ten heterozygous C. albicans isolates for this allele were positive for the HWP1-1 / HWP1-2 allele, one was homozygous for Wild Type HWP1-1 allele, and 5 were homozygous for novel/rare HWP1-2 allele. Conclusions: This study aims to provide simple, inexpensive strategies for phenotypic identification and molecular confirmation of Candida albicans and Candida dubliniensis for non-reference laboratories with low complexity and/or low budgets.

RESUMEN La cavidad oral constituye un ecosistema único con nichos ecológicos muy variables, capaz de albergar una gran variedad de microorganismos, incluidas las levaduras. Los métodos moleculares son considerados actualmente los métodos de identificación definitivos ya que a diferencia de los anteriores, nos brindan una correcta sensibilidad y especificidad. Sin embargo, existen limitaciones asociadas con la ruptura de las paredes celulares de estas levaduras para liberar el ADN genómico (gADN) necesario para la amplificación. Objetivo: El objetivo de este estudio fue comparar el rendimiento de diferentes métodos de extracción de gADN de Candida albicans y Candida dubliniensis, amplificando posteriormente por PCR. Materiales y Método: Se estudiaron 52 aislamientos, 16/52 de Candida albicans y 36/52 de Candida dubliniensis obtenidos de biofilm subgingival de pacientes VIH+ con signos clínicos de enfermedad periodontal. Se evaluaron seis métodos de extracción de gADN y la posterior amplificación se realizó por dos técnicas de PCR. Además en C. albicans se determinó la presencia de alelos para el gen HWP1. Resultados: Las comparaciones de seis métodos son estadísticamente significativas (p<0,001) excepto para C. albicans en dos de ellos. Para C. dubliniensis se observaron diferencias estadísticas en todas las comparaciones. Los métodos comerciales mostraron una mayor eficiencia en la concentración de gADN que los métodos caseros y ambos fueron efectivos en las dos PCR. 10 aislados de C. albicans resultaron positivos para el alelo HWP1-1/HWP1-2, siendo heterocigotos para este alelo. Solo un aislamiento fue homocigoto para el alelo HWP1-1 de tipo salvaje y 5 eran homocigotos para el alelo HWP1-2 nuevo/raro. Conclusiones: Este estudio tiene como objetivo proporcionar estrategias simples y económicas para la identificación fenotípica y confirmación molecular de Candida albicans y Candida dubliniensis para laboratorios de no referencia con baja complejidad y/o bajo presupuesto económico.

Expression of ERG11, ERG3, MDR1 and CDR1 genes in Candida tropicalis

Introduction. Drug resistance to azoles is a growing problem in the Candida genus. Objective. To analyze molecularly the genes responsible for fluconazole resistance in Candida tropicalis strains. Materials and methods. Nineteen strains, with and without exposure to fluconazole, were selected for this study. The expression of MDR1, CDR1, ERG11, and ERG3 genes was analyzed in sensitive, dose-dependent sensitive, and resistant strains exposed to different concentrations of the antifungal drug. Results. MDR1, ERG11 and ERG3 genes were significantly overexpressed in the different sensitivity groups. CDR1 gene expression was not statistically significant among the studied groups. Seven of the eight fluconazole-resistant strains showed overexpression of one or more of the analyzed genes. In some dose-dependent sensitive strains, we found overexpression of CDR1, ERG11, and ERG3. Conclusion. The frequency of overexpression of ERG11 and ERG3 genes indicates that they are related to resistance. However, the finding of dose-dependent resistant/sensitive strains without overexpression of these genes suggests that they are not exclusive to this phenomenon. More basic research is needed to study other potentially involved genes in the resistance mechanism to fluconazole.

Introducción. La farmacorresistencia a los azoles es un problema creciente en el género Candida. Objetivo. Analizar molecularmente los genes responsables de la resistencia a fluconazol en cepas de Candida tropicalis. Materiales y métodos. Para este estudio, se seleccionaron 19 cepas, con exposición a fluconazol y sin ella. Se analizó la expresión de los genes MDR1, CDR1, ERG11 y ERG3 en cepas sensibles, sensibles dependiente de la dosis, y resistentes, previamente expuestas a diferentes concentraciones del fármaco antifúngico. Resultados. Se encontró que los genes MDR1, ERG11 y ERG3 estaban significativamente sobreexpresados en los diferentes grupos de sensibilidad. La expresión del gen CDR1 no fue estadísticamente significativa entre los grupos estudiados. Siete de las ocho cepas resistentes a fluconazol mostraron sobreexpresión de uno o más de los genes analizados. En algunas cepas sensibles dependientes de la dosis, se encontró sobreexpresión de CDR1, ERG11 y ERG3. Conclusión. La sobreexpresión de los genes ERG11 y ERG3 indica que están relacionados con la resistencia de las cepas de Candida. Sin embargo, el hallazgo de cepas resistentes o sensibles según la dosis, sin sobreexpresión de estos genes, sugiere que pueden existir otros genes involucrados en este fenómeno. Se necesitan más investigaciones básicas que contribuyan al estudio de otros genes potencialmente involucrados en el mecanismo de resistencia al fluconazol.

Disaster mycology

Natural and human-made disasters have long played a role in shaping the environment and microbial communities, also affecting non-microbial life on Earth. Disaster microbiology is a new concept based on the notion that a disaster changes the environment causing adaptation or alteration of microbial populations-growth, death, transportation to a new area, development traits, or resistance-that can have downstream effects on the affected ecosystem. Such downstream effects include blooms of microbial populations and the ability to colonize a new niche or host, cause disease, or survive in former extreme conditions. Throughout history, fungal populations have been affected by disasters. There are prehistoric archeological records of fungal blooms after asteroid impacts and fungi implicated in the fall of the dinosaurs. In recent times, drought and dust storms have caused disturbance of soil fungi, and hurricanes have induced the growth of molds on wet surfaces, resulting in an increased incidence of fungal disease. Probably, the anticipated increase in extreme heat would force fungi adaptation to survive at high temperatures, like those in the human body, and thus be able to infect mammals. This may lead to a drastic rise of new fungal diseases in humans.

Los desastres naturales o los causados por el hombre impactan la formación de ecosistemas y comunidades microbianas, y también afectan las formas de vida no microbianas. Este concepto es conocido como "microbiología de desastres", una subespecialización de la microbiología, basada en los cambios ambientales generados por un desastre y las posibles adaptaciones o alteraciones de las poblaciones microbianas -crecimiento, muerte, trasporte a una nueva región, o adquisición de resistencia o de nuevas características- que influirán en el moldeamiento del ecosistema transformado. Algunos de los efectos de estas adaptaciones pueden ser: el surgimiento de poblaciones microbianas, la habilidad de colonizar nuevos nichos u huéspedes, la generación de nuevas enfermedades, o el crecimiento de microorganismos en condiciones que antes eran "extremas" para ellos. A lo largo de la historia, varias poblaciones de hongos han sido afectadas por desastres. Existen registros arqueológicos prehistóricos que evidencian la presencia y el crecimiento de hongos luego del impacto de asteroides, y otros de hongos relacionados con la extinción de los dinosaurios. Actualmente, las sequías y las tormentas de polvo causan perturbaciones en las comunidades de hongos del suelo, y los huracanes inducen el crecimiento de hongos filamentosos en superficies húmedas, lo que aumenta la cantidad de enfermedades por hongos. Además, con el aumento de las temperaturas extremas es posible que los hongos puedan adaptarse para sobrevivir a temperaturas más altas, equivalentes a las temperaturas corporales, y nuevas especies puedan infectar mamíferos. Esto puede llevar a un aumento drástico de las infecciones fúngicas en humanos.

Candida auris: a global pathogen that has taken root in Colombia

Candida auris has been recognized as an emerging multidrug-resistant pathogen with a significant public health burden, causing cases of invasive infection and colonization due to its persistence on inanimate surfaces, ability to colonize skin of some patients, and high transmissibility in healthcare settings. The first sporadic report of the isolation of this species from the ear canal of a patient in Asia was in 2009 and reports from other regions of the world soon followed. However, it was not until 2015 that global epidemiological alerts were communicated as a result of an increasing number of reports of invasive infections caused by C. auris in several countries. Colombia was soon added to this list in 2016 after an unusual increase in the number of C. haemulonii isolates was reported, later confirmed as C. auris. Since the issuing of a national alert by the Colombian National Institute of Health together with the Ministry of Health in 2016, the number of cases reported reached over 2,000 by 2022. Colombian isolates have not shown pan resistance to available antifungals, unlike C. auris strains reported in other regions of the world, which leaves patients in Colombia with therapeutic options for these infections. However, increasing fluconazole resistance is being observed. Whole-genome sequencing of Colombian C. auris isolates has enhanced molecular epidemiological data, grouping Colombian isolates in clade IV together with other South American isolates. Data from Colombia showed that public health authorities, scientific community, and the general public need to be aware of fungal diseases as they present an often-deadly threat to patients.

Candida auris ha sido reconocido como un agente patógeno multirresistente emergente con una carga significativa en la salud pública. Genera casos de infección invasiva y colonización debido a su persistencia en superficies inanimadas, su capacidad para colonizar fácilmente la piel de algunos pacientes y su alta transmisibilidad en el ambiente hospitalario. El primer reporte esporádico de esta especie fue en Asia en el 2009 cuando se realizó su aislamiento a partir del conducto auditivo de un paciente, y pronto le siguieron reportes en otras regiones del mundo. Sin embargo, no fue hasta 2015 que se conocieron las alertas epidemiológicas a nivel mundial debido a un aumento en el número de casos de infecciones causadas por C. auris en varios países. Colombia se sumó a la lista en 2016 luego de un aumento inusual en el número de aislamientos de C. haemulonii informados, que luego se confirmaron como C. auris. Desde que el Instituto Nacional de Salud junto con el Ministerio de Salud emitieron la Alerta Nacional en el 2016, el número de casos reportados superó los 2.000 en el 2022. Los aislamientos colombianos no han mostrado resistencia generalizada a los antifúngicos disponibles, contrario a lo reportado para cepas de C. auris en algunas regiones del mundo, por lo que los pacientes en Colombia aún cuentan con opciones terapéuticas para estas infecciones. No obstante, se ha observado un aumento en la resistencia al fluconazol. La secuenciación del genoma completo agrupó los aislamientos colombianos en el Ciado IV, junto con otros sudamericanos de C. auris, y aportó al conocimiento de los datos epidemiológicos moleculares de esta especie. Los datos de Colombia evidencian que las autoridades de salud pública, la comunidad científica y el público en general deben ser conscientes de las enfermedades fúngicas, ya que a menudo representan una amenaza mortal para los pacientes.

Tipificación bioquímica y evaluación de la patogenicidad de aislamientos vulvovaginales del complejo Candida albicans

Introducción. Candida albicans, C. dubliniensis y C. africana forman el complejo Candida albicans. Objetivo. Identificar las características fenotípicas y patogénicas de aislamientos del complejo C. albicans conservados en una colección. Materiales y métodos. Se evaluaron 300 aislamientos identificados presuntivamente como del complejo C. albicans, utilizando CHROMagarTM Candida. Se determinó la producción del tubo germinal mediante tres métodos, se evaluó la producción de clamidosporas, se caracterizaron las colonias en agares artesanales (Rosmarinus officinalis y Nicotiana tabacum) y se utilizó MALDI-TOF como prueba de referencia para la identificación. Para detectar factores de patogenicidad, se evaluó la actividad hemolítica de los aislamientos independientes y en cocultivo con Staphylococcus aureus, la producción de enzima coagulasa y la formación de biopelículas. Resultados. El 43,7 % de los aislamientos produjo tubo germinal en caldo de medio infusión de cerebro-corazón y el 47 % generó clamidosporas. En los medios artesanales, en el 6 % de los aislamientos se obtuvieron colonias de color café en agar romero y, en el 5 %, en agar tabaco. Ninguna de las cepas hemolizó el agar sangre comercial (ni en presencia o ausencia de S. aureus), mientras que el 50 % hemolizó el agar papa dextrosa suplementado con sangre. Todos los aislamientos produjeron enzima coagulasa y la producción de biopelículas fue variable. Para la producción de tubo germinal, el método de suero humano mostró igual positividad que el de caldo de leche. Todos los aislamientos fueron identificados como C. albicans por MALDITOF. Conclusiones. Se requieren herramientas de proteómica y pruebas moleculares, o la combinación de métodos, para poder discriminar entre especies.

Introduction. Candida albicans, C. dubliniensis, and C. africana form the Candida albicans complex. Objective. To identify the phenotypic and pathogenic characteristics of isolates of the C. albicans complex preserved in a collection. Materials and methods. Three hundred presumptive strains of the C. albicans complex were evaluated using CHROMagarTM Candida. Germ tube production was determined by three methods, chlamydospores formation was assessed and colonies were characterized in artisanal agars (Rosmarinus officinalis and Nicotiana tabacum). MALDI-TOF was used as the gold standard identification test. To detect pathogenicity factors, we evaluated the hemolytic activity of each isolate and cocultured with Staphylococcus aureus, coagulase enzyme production, and biofilm formation. Results. Out of the 300 isolates, 43.7% produced germ tube in the heart-brain infusion broth and 47% of the isolates produced chlamydospores. In the artisan media, 6% of the isolates produced brown colonies on rosemary agar and 5% did so on tobacco agar. None of the strains hemolyzed the blood agar alone or cocultured with S. aureus. However, 50% of the isolates hemolyzed the potato dextrose agar supplemented with blood. All strains were coagulase producers, and biofilm production was variable. For germ tube production, the human serum method showed the same positivity as the milk broth method. All isolates were identified as C. albicans by MALDI-TOF. Conclusions. The use of proteomics, molecular tests or a combination of methods is required for species identification.

Actividad de fosfolipasas y proteasas en aislamientos de especies de Candida colonizadoras y causantes de vulvovaginitis en mujeres gestantes / Phospholipase and proteinase activities of isolatesof colonizing Candida spp. causing vulvovaginitis in pregnant women

Introducción. Las proteasas y las fosfolipasas son factores de virulencia de Candida spp. que cumplen un papel importante en la invasión de los tejidos. Entre los factores relacionados con el huésped, se encuentran algunos asociados con las características ambientales y otros con la colonización. Objetivo. Determinar la actividad de fosfolipasas y proteasas en aislamientos de especies colonizadoras y patógenas de Candida spp., aisladas de mujeres gestantes de Cartagena de Indias. Materiales y métodos. Se determinó la actividad de fosfolipasas y proteasas en 56 aislamientos mediante degradación del sustrato y cálculo del coeficiente de actividad enzimática. Se compararon las actividades de fosfolipasas y proteasas, entre los aislamientos colonizadores y los patógenos. Resultados. La actividad de la fosfolipasa fue "muy alta" (< 0,69) en 34 aislamientos e, igualmente, la de la proteasa en 14. No hubo diferencias significativas al comparar las actividades de las fosfolipasas y de las de las proteasas, entre los aislamientos colonizadores y los patógenos. Conclusiones. La actividad de las fosfolipasas predominó como factor de virulencia en los aislamientos estudiados. No obstante, no se encontró una diferencia significativa entre los grupos de aislamientos colonizadores y los patógenos, en cuanto a las actividades de fosfolipasas y proteasas.

Introduction. Proteases and phospholipases are virulence factors of Candida spp. that play an important role in tissue invasion. Among the factors related to the host some are associated with environmental characteristics and others with Candida colonization. Objectives. To determine phospholipase and protease activities in colonizing and pathogenic strains, isolated from pregnant women in Cartagena de Indias. Materials and methods. Phospholipase and protease activity was determined in 56 isolates, evaluating substrate degradation and calculating the enzyme activity coefficient. Phospholipase and protease activities were compared between colonizing and pathogenic strains. Results. "Very high" (<0.69) phospholipase and protease activity was found in 34 and 14 isolates, respectively. There was no significant difference when comparing phospholipase and protease activities between colonizing and pathogenic isolates. Conclusions. Phospholipase activity predominated as a virulence factor in the studied strains, but no significant difference was found between colonizing and pathogenic strains for phospholipase and protease activities.

Candidiasis oral mixta en pacientes con diabetes de tipo 2: identificación y espectro de sensibilidad / Mixed oral candidiasis in type 2 diabetic patients: Identification and spectrum of sensitivity

Introducción. Los pacientes con diabetes mellitus de tipo 2 son propensos a adquirir infecciones por Candida spp., en ocasiones, causadas por más de una especie. La resistencia de algunas de ellas puede resultar en complicaciones médicas por falla del tratamiento. Objetivos. Determinar la frecuencia y las variedades clínicas de la candidiasis oral mixta en pacientes con diabetes mellitus de tipo 2, las especies de Candida involucradas y sus espectros de sensibilidad a los antifúngicos utilizados como tratamiento. Materiales y métodos. Se hizo un estudio transversal analítico en pacientes con diabetes mellitus de tipo 2, hiperglucemia (superior o igual al 7 % de la hemoglobina glucosilada, HbA1C) y con diagnóstico clínico de candidiasis oral. Mediante técnicas microbiológicas, se identificaron las especies causales de la candidiasis oral. Las pruebas de sensibilidad se llevaron a cabo con el método de difusión en placa con tiras (E-test®). Resultados. Se incluyeron 72 pacientes: 32 (44 %) hombres y 40 (56 %) mujeres, clasificados en tres grupos de edad: jóvenes adultos (17 %), adultos (74 %) y ancianos (9 %), con una media de 51 años. No se encontraron diferencias significativas en la candidiasis oral según los grupos de sexo y edad, ni entre las candidiasis orales mixtas y el sexo, el porcentaje de HbA1C, el tratamiento antihiperglucemiante o el tiempo de diagnóstico de la diabetes mellitus de tipo 2. En el grupo etario de adultos, se encontró una correlación con las candidiasis mixtas o simples. Se encontraron 8 (13 %) casos de candidiasis mixtas: siete con coinfección por dos especies de Candida y uno con coinfección por tres especies. Las especies identificadas en ellos, fueron: Candida albicans, C. glabrata, C. dubliniensis, C. kefyr, C. tropicalis y C. krusei. La mayoría de estas especies presentó sensibilidad a ketoconazol y fluconazol, y mayor resistencia a itraconazol. Conclusiones. Las candidiasis orales mixtas se presentan, aproximadamente, en el 10 % de los pacientes con diabetes mellitus de tipo 2 y el tratamiento puede ser ineficaz cuando no se identifica el agente etiológico.

Introduction. Patients with type 2 diabetes mellitus are susceptible to acquire Candida spp. infections, sometimes involving more than one species. The resistance of some species to antimycotic agents can cause treatment failure. Objectives. To determine the frequency and clinical varieties of mixed oral candidiasis in patients with type 2 diabetes mellitus, the involved species, and its sensitivity spectra when exposed to antifungals used as candidiasis treatment. Materials and methods. We developed an analytical cross-sectional study with 72 patients with type 2 diabetes mellitus with hyperglycemia (HbAIC s 7%) and an oral candidiasis diagnosis. The causal species of oral candidiasis were identified through microbiological techniques, and sensitivity tests were carried out using the diffusion method in a plate with strips (E-test ®). Results. We included 72 patients in the study, 32 (44%) males and 40 (56%) females. Patients were divided into three age groups: young adults (17%), adults (74%), and older adults (9%). The mean age of the patients was 51 years. No significant differences were found between mixed oral candidiasis and groups (sex and age), or between mixed oral candidiasis and gender, glycosylated hemoglobin level (HbA1C), antihyperglycemic treatment, or type 2 diabetes mellitus time of diagnosis. We found a correlation between the adult group and development of mixed or simple oral candidiasis. The results showed eight (13%) cases of mixed oral candidiasis: seven with a coinfection of two species and one with a coinfection of three species. The identified species were Candida albicans, C. glabrata, C. dubliniensis, C. kefyr, C. tropicalis, and C. krusei. Most of these species presented sensitivity against ketoconazole and fluconazole, and higher resistance to itraconazole. Conclusions. Mixed oral candidiasis occurs in approximately 10% of the patients with type 2 diabetes mellitus and its treatment can be ineffective when the etiological agent is not identified.

Elimination of E. faecalis and C. albicans Biofilm: A comparison between single and multiple file systems in an Ex Vivo study

To evaluate whether the WaveOne Gold and Reciproc single file instrumentation systems, are effective in reducing the microbial load of a mixed biofilm and the cleaning of apical third compared to the Twisted File Adaptive system (multiple- file system). Seventy mesial roots of the first and second molars were included and randomly divided into three experimental groups (n=20, n=10 controls). Biofilms were formed inside canals over 31 days. After instrumentation with the unique file systems, WaveOne Gold and Reciproc and the multiple file system Twisted File Adaptive, using 2.25% sodium hypochlorite as an irrigant in all cases, a count of colony forming units was performed using serial dilutions, cleaning of the apical third was evaluated using scanning electron microscopy. Comparisons amongst groups were made by using parametric and non-parametric statistics, according to a normal or non-normal data distribution, respectively. No significant differences in the reduction of the microbial load after employing a single-file system in comparison to the multiple-file system were found; in addition, the cleaning of the apical third was similar for the three different instrumentation systems. The single-file system is equal in effectiveness compared with the multiple-file system in reducing the microbial load.

Evaluar si los sistemas de instrumentación de lima única, como WaveOne Gold y Reciproc son efectivos para reducir la carga microbiana de un biofilm mixto y la limpieza del tercio apical, comparado con los sistemas de limas múltiples, como Twisted File Adaptive. Setenta raíces mesiales de primeros y segundos molares fueron incluidos y divididos de forma aleatoria en tres grupos experimentales (n=20, n=10 controles). El biofilm fue formado en el interior de los conductos durante 31 días. Después se instrumentó con los sistemas de lima única (WaveOne Gold y Reciproc) y el sistema de limas múltiples Twisted File Adaptive, usando hipoclorito de sodio al 2.5% en todos los casos. El conteo de unidades formadoras de colonias se realizó usando diluciones seriales, la limpieza del tercio apical se evaluó empleando el microscopio electrónico de barrido. La comparación entre grupos se realizó con pruebas paramétricas y no paramétricas, de acuerdo con la distribución normal y no normal de los datos, respectivamente. No hubo una diferencia significativa en la reducción de la carga microbiana después de emplear los sistemas de lima única en comparación a los de limas múltiples, además, la limpieza del tercio apical fue similar en los 3 diferentes sistemas de instrumentación. Los sistemas de lima única son igual de efectivos para reducir la carga microbiana comparados con los sistemas de limas múltiples.

Antifungal activity and physical characterization of an experimental dentifrice containing carvacrol

Introduction: The successful treatment of oral candidiasis depends on three essential principles, namely: early and accurate diagnosis, correlation with predisposing factors or underlying diseases that compromise immunity, and appropriate use of antifungal drugs. Objectives: To determine the minimum inhibitory concentration of carvacrol against Candida albicans and to develop and evaluate the in vitro antifungal activity (diameter of inhibition zone) and physical properties (foaming capacity, spreadability and cleaning capacity) of an experimental dentifrice containing carvacrol. Methods: The carvacrol was incorporated into a dentifrice base at different concentrations and tested for its minimum inhibitory concentration and agar diffusion against Candida albicans and the physical properties. Data were analysed by ANOVA. Results: The minimum inhibitory concentration of carvacrol was 1041.67 ± 360.84 µg/mL. The dentifrice containing carvacrol C1 e C2 produced an inhibition zone of 27.50 ± 2.12 mm and 36.66 ± 2.08 mm, respectively (p<0.05). As for the physical properties, the dentifrices showed no foaming capacity, while their cleaning capacity and spreadability remained unaltered. Conclusions: The experimental dentifrices containing carvacrol showed antifungal activity. The incorporation of carvacrol significantly altered the foaming capacity of the formulations, without any significant effects on their cleaning capacity and spreadability.

Introducción: El tratamiento exitoso de la candidiasis oral depende de tres principios esenciales, a saber: diagnóstico temprano y preciso, correlación con factores predisponentes o enfermedades subyacentes que comprometan la inmunidad y uso apropiado de medicamentos antimicóticos. Objetivos: Determinar la concentración inhibitoria mínima de carvacrol contra Candida albicans y desarrollar y evaluar la actividad antifúngica in vitro (diámetro de la zona de inhibición) y las propiedades físicas (capacidad espumante, esparcibilidad y capacidad de limpieza) de un dentífrico experimental que contiene carvacrol. Métodos: El carvacrol se incorporó a una base dentífrica a diferentes concentraciones y se probó su concentración mínima inhibitoria y difusión en agar contra Candida albicans y las propiedades físicas. Los datos fueron analizados por ANOVA. Resultados: La concentración mínima inhibitoria de carvacrol fue 1041,67 ± 360,84 µg/mL. El dentífrico con carvacrol C1 y C2 produjo un halo de inhibición de 27,50 ± 2,12 mm y 36,66 ± 2,08 mm, respectivamente (p < 0,05). En cuanto a las propiedades físicas, los dentífricos no mostraron capacidad espumante, mientras que su capacidad de limpieza y esparcibilidad permanecieron inalteradas. Conclusiones: Los dentífricos experimentales que contenían carvacrol mostraron actividad antifúngica. La incorporación de carvacrol alteró significativamente la capacidad espumante de las formulaciones, sin efectos significativos sobre su capacidad de limpieza y esparcibilidad.

Evaluación antifúngica del ozono contra Candida albicans: estudio in vitro / Antifungal evaluation of ozone against Candida albicans: in vitro study

Introducción: la Candida albicans (C. albicans) es un patógeno fúngico que puede causar infecciones superficiales o potencialmente mortales. Los biofilms de C. albicans muestran rasgos fenotípicos únicos, el más destacado es su notable resistencia a una amplia variedad de agentes antimicóticos. Una de las alternativas para inhibir el crecimiento de este microorganismo es el ozono debido a sus propiedades bactericidas, fungicidas y virucidas; sin embargo, escasa información ha sido reportada en C. albicans. Objetivo: el objetivo de este estudio fue evaluar el efecto fungicida del ozono en C. albicans. Material y métodos: la metodología consistió en agregar ozono a tubos de ensayo con medios de caldo nutritivo en diversas concentraciones y tiempos de ozonización. El efecto fungicida fue determinado con la determinación del número de colonias de C. albicans en agar nutritivo a través de procedimiento microbiológicos estandarizados por triplicado. Resultados: todas las muestras con ozono mostraron adecuados niveles de inhibición de crecimiento del microorganismo. Además, el efecto fungicida del ozono se encontró para ser significativamente dependiente del tiempo de ozonización y de la concentración. Conclusión: el uso de terapia con ozono podría tener potencial en el control de infecciones micóticas causadas por la presencia de C. albicans (AU)

Introduction: Candida albicans (C. albicans) is a fungal pathogen that can cause superficial or life-threatening infections. Biofilms of C. albicans display unique phenotypic traits, the most prominent being their remarkable resistance to a wide variety of antifungal agents. One of the alternatives to inhibit the growth of this microorganism is ozone due to its bactericidal, fungicidal and virucidal properties; however, little information has been reported on C. albicans. Objective: the objective of this study was to evaluate the fungicidal effect of ozone on C. albicans. Material and methods: the methodology consisted in adding ozone to test tubes with nutrient broth media in various concentrations and ozonation times. The fungicidal effect was determined by determining the number of colonies of C. albicans in nutrient agar through standardized microbiological procedures in triplicate. Results: all the ozone samples showed adequate levels of growth inhibition of the microorganism. Furthermore, the fungicidal effect of ozone was found to be significantly dependent on ozonation time and concentration. Conclusion: the use of ozone therapy could have potential in the control of fungal infections caused by the presence of C. albicans (AU)

Epithelial responses and Candida albicans pathogenicity are enhanced in the presence of oral streptococci

Abstract Experimental models that consider host-pathogen interactions are relevant for improving knowledge about oral candidiasis. The aim of this study was to assess the epithelial immune responses, Candida penetration of cell monolayers, and virulence during mixed species culture infections. Single species cultures of Candida albicans and mixed cultures (C. albicans, Streptococcus mutans, and Streptococcus sanguinis) were used to infect monolayers of HaCaT and FaDu ATCC HTB-43 cells for 12 h. After infection, IL-18 and IL-34 gene expression was measured to assess epithelial cell immune responses, and lactate dehydrogenase (LDH) activity was measured as an indicator of cell damage. Microscopy determined C. albicans morphology and penetration of fungal cells through the keratinocyte monolayer. Monolayers devoid of infection served as controls. Data were analyzed by an ANOVA one-way test followed by Tukey's post-hoc test (α = 0.05). The results found that IL-18 and IL-34 gene expression and LDH activity were significantly (p < 0.05) upregulated for both cell lines exposed to mixed species cultures compared with C. albicans alone. Candida albicans yeast and hyphae were evident in C. albicans only infections. In contrast, monolayers infected by C. albicans, S. mutans, and S. sanguinis exhibited higher microbial invasion with several hyphal aggregates detected. The presence of streptococci in C. albicans infection enhances the virulence and pathogenicity of the fungus with associated increased immune responses and tissue damage. Extrapolation of these findings to oral infection would indicate the added potential benefit of managing bacterial components of biofilms during treatment.

Resumo O objetivo deste estudo foi avaliar a resposta epithelial imune, a colonização da Candida albicans em monocamadas celulares e sua virulência em resposta a infecções de culturas de biofilme multiespécie. Culturas de biofilme monoespécie de C. albicans e culturas mistas (C. albicans, Streptococcus mutans e Streptococcus sanguinis) foram utilizadas para infectar monocamadas de células HaCaT e FaDu por 12 h. Após a infecção, a expressão dos genes IL-18 e IL-34 foi medida para avaliar as respostas imunes das células epiteliais. A atividade da lactato desidrogenase (LDH) foi medida como um indicador de dano celular. A microscopia determinou a morfologia de C. albicans e a penetração das células fúngicas através da monocamada de queratinócitos. Monocamadas em que não houve infecção serviram como controles. Os dados foram analisados por um teste ANOVA one-way seguido pelo teste post-hoc de Tukey (α = 0,05). Os resultados demonstraram que a expressão gênica de IL-18 e IL-34 e a atividade de LDH foram (p < 0,05) reguladas positivamente para ambas as linhagens de células expostas a culturas de espécies mistas em comparação com C. albicans isoladamente. Leveduras de C.albicans e hifas foram evidentes em infecções apenas por C. albicans. Entretanto, monocamadas infectadas por C. albicans, S. mutans e S. sanguinis exibiram maior invasão microbiana com vários agregados de hifas detectados. Dessa maneira, a presença de estreptococos na infecção por C. albicans aumentou a virulência e a patogenicidade do fungo com respostas imunes aumentadas associadas a danos nos tecidos. A extrapolação desses achados para a infecção oral indicaria o potencial benéfico do controle dos componentes bacterianos em biofilmes durante a terapia da candidíase

Candida albicans the main opportunistic pathogenic fungus in humans / Candida albicans el principal hongo patógeno oportunista en humanos

Abstract Candida albicans is a commensal of the mammalian microbiome and the primarypathogenic fungus of humans. It becomes a severe health problem in immunocompromisedpatients and can cause a wide variety of mucosal and systemic infections. The interactionbetween C. albicans and host cells is characterized by the expression of virulence factors suchas adhesins and invasins, the secretion of hydrolytic enzymes, a transition from yeast to fil-amentous hyphae form, and the ability to form biofilms; these features collectively result in cell adhesion, invasion, and damage. This review describes complex commensal interactions of C. albicans with host cells and the cellular events that it triggers in a pathogenic environment. We also review the host immune response induced by C. albicans antigens and the mechanisms developed by this fungus to avoid the action of antifungal agents.

Resumen Candida albicans es un comensal del microbioma de mamíferos y el principal hongopatógeno de humanos. En pacientes inmunocomprometidos se convierte en un grave problemade salud por causar una amplia variedad de infecciones en mucosas y sistémicas. La interacciónentre C. albicans y las células del huésped lleva a la expresión de factores de virulencia, comoadhesinas e invasinas, a la secreción de enzimas hidrolíticas y a la transición de levadura a hifa filamentosa, capaz de para formar biopelículas, lo que genera adherencia, invasión y dano celular. En esta revisión describimos la compleja interacción comensal de C. albicans con la célula huésped y los eventos celulares que ejecuta en un ambiente patogénico. También se revisa la respuesta inmunitaria del huésped inducida por antígenos de C. albicans y los mecanismos desarrollados por este hongo para evitar la acción de agentes antifúngicos.

Healthcare-associated blood stream infections: An evaluation of blood culture as indicator

Background: A nosocomial infection or healthcare-associated illness that develops in patients after they are admitted to the hospital but was not present or incubating at the time of admission is referred to as a hospital acquired infection. In patients with severe viral and fungal infections today, it is one of the most prevalent and life-threatening consequences. Blood culture is one of the most important diagnostic tools for the diagnosis of hospital acquired infections. It can also help in providing a clinical as well as an etiological diagnosis. Aims and Objectives: The aim of the study is early detection of blood stream infections along with its antibiotic susceptibility pattern. Materials and Methods: All samples were obtained and processed using conventional microbiological techniques, and an antibiotic sensitivity test was carried out in accordance with CLSI recommendations. Results: Total 160 samples were processed, out of which 54 (34%) samples were positive. Out of 54 positive blood sample, maximum samples were from NICU (28) 52%, followed by causality (10) 18%, PICU (4) 7%, HDU (2) 3%, intensive careunit (4) 7%, surgery (6) 11%, and overall males contributed to higher positivity rate. Total nine different organisms were isolated, out of which Gram negative bacilli were comprised 40 (74%), Gram positive cocci 8 (14%) and Candida were 6 (11%). Among Gram-negative bacilli of most common species were Klebsiella pneumonia (30%), Acinetobacter baumanii (18%), Pseudomonas aeruginosa (11%), Burkhoderia cepacia (11%), and Serratia fonticola (3%). The most prevalent isolated species of gram-positive cocci were Staphylococcus aureus (11%), Coagulase negative S. aureus (3%), and Enterococcus faecalis (3%). Conclusion: This study on blood culture gives insight to magnitude of hospital acquired infections in our set up. Again result of antibiotic susceptibility tests gives overview of drug resistance problem at our set up. This may help in antibiotic stewardship program.