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1.
Lett Appl Microbiol ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658187

RESUMO

Species from Candida parapsilosis complex are frequently found in neonatal candidemia. The antifungal agents to treat this infection are limited and the occurrence of low in vitro susceptibility to echinocandins such as micafungin has been observed. In this context, the chaperone Hsp90 could be a target to reduce resistance. Thus, the objective of this research was to identify isolates from the C. parapsilosis complex and verify the action of Hsp90 inhibitors associated with micafungin. The fungal identification was based on genetic sequencing and mass spectrometry. Minimal Inhibitory Concentrations were determined by broth microdilution method according to CLSI. The evaluation of the interaction between micafungin with Hsp90 inhibitors was realized using the checkerboard methodology. According to the polyphasic taxonomy C. parapsilosis sensu stricto was the most frequently identified, followed by C. orthopsilosis and C. metapsilosis, and one isolate of Lodderomyces elongisporus was identified by genetic sequencing. The Hsp90 inhibitor geladanamycin associated with micafungin showed a synergic effect in 31.25% of the isolates, a better result was observed with radicicol that shows synergic effect in 56.25% tested yeasts. The results obtained demonstrate that blocking Hsp90 could be effective to reduce antifungal resistance to echinocandins.

2.
Clin Oral Investig ; 28(4): 225, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38514526

RESUMO

OBJECTIVE: To investigate how delayed blood centrifugation affects the composition of the resultant platelet rich fibrin membrane (PRF, a concentrated growth factor preparation) and its biological effects towards gingival fibroblasts. MATERIALS AND METHODS: Blood samples were collected from 18 healthy individuals and centrifuged immediately (T-0), or after a 1-6-minute delay (T-1-6, respectively), to generate PRF. Each PRF membrane was weighed. T-0 and T-6 membranes were incubated for 48 h in cell culture medium at 37 °C to create PRF "releasates" (soluble factors released from the PRF). Human gingival fibroblasts were incubated for 48 h with or without the releasates, followed by RNA isolation and real-time polymerase chain reaction to measure expression of select genes associated with granulation tissue formation, angiogenesis and wound contraction. Additional T-0 and T-6 membranes were used for visualization of leucocyte nuclei and platelets by immunostaining. RESULTS: Immediate centrifugation (T-0) resulted in the largest membranes, T-6 membranes being on average 29% smaller. Leucocytes and platelets were significantly more abundant in T-0 than in T-6 samples. Majority of the fibroblast genes studied were consistently either upregulated or downregulated by the T-0 PRF releasates. However, centrifugation after a 6-minute delay significantly weakened the fibroblast responses. CONCLUSIONS: Delayed centrifugation resulted in smaller PRF membranes with fewer leucocytes and platelets and also significantly reduced on the expression of a set of healing-related gingival fibroblast genes. CLINICAL RELEVANCE: The higher expression of wound healing-related genes in gingival fibroblasts by the immediately-centrifuged PRF membranes may increase their biological properties in clinical use.


Assuntos
Fibrina Rica em Plaquetas , Humanos , Plaquetas , Cicatrização , Leucócitos , Centrifugação/métodos
3.
Immunobiology ; 229(1): 152748, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38128238

RESUMO

The present study aimed to inspect the serum levels of the soluble receptors, sTNFR1 and sTNFR2, in patients with COVID-19. The large production of inflammatory cytokines is an essential process in the pathogenesis of COVID-19. TNF is a multifaceted proinflammatory cytokine which has soluble and membrane receptors. Thus, knowing the role of these receptors will help better understand this disease's immunopathogenesis. We included 131 patients confirmed for SARS-CoV-2, separated into three groups: ward patients without O2 support, group A (n = 14); ward patients with O2 support, group B (n = 85), and patients in an intensive care unit (ICU), group C (n = 32), making up the receptors dosed by flow cytometry. The results showed that sTNFR1 and sTNFR2 are associated with disease severity, being higher in group C when compared to group A. As for the levels of receptors and their relationship with the degree of lung involvement, we found higher values of sTNFR1 in patients in group 1 (pulmonary involvement < 25%), suggesting that inflammatory processes related to TNF are not necessarily associated with the primary site of infection. When we analysed the patients who passed away compared to those who recovered, both receptors significantly increased the mortality numbers. These findings suggest a relevant influence of soluble receptors in the inflammatory processes involved in the pathogenesis of COVID-19. Wherefore, we suggest using these receptors as biomarkers of severity and mortality of the disease.


Assuntos
COVID-19 , Receptores Tipo I de Fatores de Necrose Tumoral , Humanos , Receptores Tipo II do Fator de Necrose Tumoral , SARS-CoV-2 , Citocinas , Fator de Necrose Tumoral alfa
4.
Biofouling ; 39(7): 719-729, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37698054

RESUMO

The present study aimed to: (1) evaluate the influence of the steroid hormones (SH) on biofilm development; (2) investigate the formation of persister cells (PC) in biofilms; and (3) investigate the influence of SH on PC formation. Biofilms were derived from vulvovaginal candidiasis (VVC) samples and evaluated by three models: microcosm biofilms grown in Vaginal Fluid Simulator Medium (MiB-VFSM); monospecies biofilms grown in VFSM (MoB-VFSM) and RPMI media (MoB-RPMI). SH altered cell counting and biomass of biofilms grown in VSFM; MoB-RPMI were negatively affected by SH. SH stimulated the formation of PC in MiB-VFSM but not MoB-VFSM; MoB-RPMI showed a lower number of PC in the presence of SH. The results showed that SH altered the dynamics of biofilm formation and development, depending on the study model. The data suggest the influence of hormones on the physiology of Candida biofilms and reinforce the importance of PC in the pathogenesis of VVC.

5.
Braz J Microbiol ; 54(3): 1513-1521, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37540461

RESUMO

The aim of this study was to evaluate the efficacy and non-toxicity of ciclopirox olamine-loaded liposomes against Cryptococcus neoformans clinical isolates. Initially, 24-1 fractional experimental design was carried out to obtain an optimized formulation of liposomes containing CPO (CPO-LipoC), which were then used to prepare stealth liposomes (CPO-LipoS). Liposomal formulations were characterized by their mean size diameter, polydispersity index (PDI), and drug encapsulation efficiency (EE%). Immunosuppressed mice were exposed to CPO-LipoS at 0.5 mg/kg/day for 14 days to verify possible histopathological alterations in the liver and kidneys. Immunosuppressed mice infected with C. neoformans were treated with CPO-LipoS at 0.5 mg/kg/day for 14 days to quantify the fungal burden in spleen, liver, lungs, and brain. CPO-LipoS presented a mean size diameter, PDI, and EE% of 101.4 ± 0.7 nm, 0.307, and 96.4 ± 0.9%, respectively. CPO-LipoS was non-toxic for the liver and kidneys of immunosuppressed mice. At the survival curve, all infected animals submitted to treatment with CPO-LipoS survived until the end of the experiment. Treatment with CPO-LipoS reduced C. neoformans cells in the spleen (59.3 ± 3.4%), liver (75.0 ± 3.6%), lungs (75.7 ± 6.7%), and brain (54.2 ± 3.2%). CPO-LipoS exhibit antifungal activity against C. neoformans, and the encapsulation of CPO into stealth liposomes allows its use as a systemic drug for treating cryptococcosis.


Assuntos
Criptococose , Cryptococcus neoformans , Animais , Camundongos , Ciclopirox/uso terapêutico , Lipossomos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Criptococose/tratamento farmacológico , Criptococose/microbiologia
6.
Viruses ; 15(5)2023 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-37243290

RESUMO

Cryptococcal meningitis is a serious infection of the central nervous system that is predominant in developing countries, caused by fungi of the genus Cryptococcus, and which affects immunosuppressed patients, especially those with HIV. Here, we aim to diagnose and characterize the clinical-epidemiological profile of cryptococcosis in patients admitted to two tertiary public hospitals in northeastern Brazil. The study is divided into three moments: (1) the isolation of fungus and diagnosis from biological samples collected between 2017 and 2019, (2) a description of the clinical and epidemiological characteristics of the patients, and (3) the experimental tests related to an in vitro susceptibility antifungal profile. The species were identified by MALDI-TOF/MS. Among the 100 patients evaluated, 24 (24.5%) were diagnosed with cryptococcosis based on positive culture. Clinical-epidemiological analysis showed a slightly higher prevalence in men between 30 and 39 years. When comparing the date of HIV diagnosis and the development of cryptococcosis, it was observed that 50% received the diagnosis of infection by cryptococcosis after or equal to a period of 12 months from being diagnosed with HIV; the other 50% received it within the first 30 days of the HIV diagnosis. Neurocryptococcosis was the most prevalent clinical form, and, at the time of hospital admission, the most common clinical signs were high fever (75%), intense headache (62.50%), and neck stiffness (33.33%). The cerebrospinal fluid showed 100% sensitivity and positivity for direct examination by India ink, and fungal culture. The mortality rate in this study was 46% (11/24), a lower rate than in the other literature. An antifungigram showed that 20 (83.33%) isolates were susceptible to amphotericin B and 15 (62.5%) to fluconazole. Mass spectrometry identified 100% of the isolates as Cryptococcus neoformans. In Brazil, this infection is not mandatory notifiable. Therefore, although there is little information on the subject, it is obsolete and does not express the reality of the facts, mainly in the northeast region, where this information is insufficient. The data obtained in this research contribute to the epidemiological knowledge of this mycosis in Brazil and will serve as a basis for future globally comparative epidemiological studies.


Assuntos
Criptococose , Cryptococcus neoformans , Infecções por HIV , Masculino , Humanos , Brasil/epidemiologia , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Criptococose/epidemiologia , Criptococose/complicações , Criptococose/diagnóstico , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Infecções por HIV/microbiologia
7.
Mem Inst Oswaldo Cruz ; 118: e220251, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36946852

RESUMO

Meningitis is a potentially life-threatening infection characterised by the inflammation of the leptomeningeal membranes. The estimated annual prevalence of 8.7 million cases globally and the disease is caused by many different viral, bacterial, and fungal pathogens. Although several genera of fungi are capable of causing infections in the central nervous system (CNS), the most significant number of registered cases have, as causal agents, yeasts of the genus Cryptococcus. The relevance of cryptococcal meningitis has changed in the last decades, mainly due to the increase in the number of people living with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and medications that impair the immune responses. In this context, coronavirus disease 19 (COVID-19) has also emerged as a risk factor for invasive fungal infections (IFI), including fungal meningitis (FM), due to severe COVID-19 disease is associated with increased pro-inflammatory cytokines, interleukin (IL)-1, IL-6, and tumour necrosis factor-alpha, reduced CD4-interferon-gamma expression, CD4 and CD8 T cells. The gold standard technique for fungal identification is isolating fungi in the culture of the biological material, including cerebrospinal fluid (CSF). However, this methodology has as its main disadvantage the slow or null growth of some fungal species in culture, which makes it difficult to finalise the diagnosis. In conclusions, this article, in the first place, point that it is necessary to accurately identify the etiological agent in order to assist in the choice of the therapeutic regimen for the patients, including the implementation of actions that promote the reduction of the incidence, lethality, and fungal morbidity, which includes what is healthy in the CNS.


Assuntos
COVID-19 , Cryptococcus , Infecções por HIV , Meningite Criptocócica , Humanos , Inflamação , Fatores de Risco , Infecções por HIV/complicações
8.
Front Cell Infect Microbiol ; 13: 1033707, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36756619

RESUMO

Objective: To describe the clinical-epidemiological features of patients colonized by Candida auris in the largest outbreak in Brazil and to show the biofilm formation capacity of yeast strains. Methods: Clinical yeasts suspected of C. auris isolated from urine and surveillance samples were seeded on chromogenic media at 30°C and Sabouraud agar at 42°C. matrix-assisted laser desorption/ionization-time of flight mass spectometry was used for reliable identification. After proteomic confirmation, the genomic approach and culture on Chromagar Candida Plus media were carried out. Biofilm formation was investigated based on metabolic activity, and the clinical-epidemiological profile of patients was described. Results: A total of 11 C. auris clinical yeasts from nine patients were identified between the end of December 2021 and March 2022. Two clinical yeasts were isolates from urine and nine clinical yeasts were isolates from axillary and inguinal surveillance swabs. No case is related to previous Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, all the yeasts showed a high ability of biofilm formation. Conclusion: C. auris requires great vigilance as its high capacity to colonize and form biofilms contributes to its dissemination. The rapid and precise identification of this species is essential for the management, control, and prevention of infections.


Assuntos
Antifúngicos , COVID-19 , Humanos , Candida auris , Brasil/epidemiologia , Proteômica , SARS-CoV-2 , Biofilmes , Testes de Sensibilidade Microbiana
9.
Antonie Van Leeuwenhoek ; 116(5): 447-462, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36841923

RESUMO

Freshwater cetaceans play a significant role as sentinel animals, providing important data on animal species and aquatic ecosystem health. They also may serve as potential reservoirs of emerging pathogens and host virulence genes in their microbiota. In this study, we evaluated virulence factors produced by Gram-negative bacteria recovered from individuals belonging to two populations of free-ranging Amazon river dolphins (Inia geoffrensis). A total of 132 isolates recovered from the oral cavity, blowhole, genital opening and rectum of 21 river dolphins, 13 from Negro River and 8 from Tapajós River, Brazil, were evaluated for the production of virulence factors, such as biofilms and exoproducts (proteases, hemolysins and siderophores), in planktonic and biofilm forms. In planktonic form, 81.1% (107/132) of the tested bacteria of free-ranging Amazon river dolphins were able to produce virulence factors, with 44/132 (33.4%), 65/132 (49,2%) and 54/132 (40,9%) positive for protease, hemolysin and siderophore production, respectively. Overall, 57/132 (43.2%) of the isolates produced biofilms and, under this form of growth, 66/132 (50%), 88/132 (66.7%) and 80/132 (60.6%) of the isolates were positive for protease, hemolysin and siderophore production. In general, the isolates showed a higher release of exoproducts in biofilm than in planktonic form (P < 0.001). The present findings show that Amazon river dolphins harbor potentially pathogenic bacteria in their microbiota, highlighting the importance of monitoring the micro-organisms from wild animals, as they may emerge as pathogens for humans and other animals.


Assuntos
Golfinhos , Humanos , Animais , Fatores de Virulência/genética , Ecossistema , Proteínas Hemolisinas , Sideróforos , Bactérias Gram-Negativas , Peptídeo Hidrolases
10.
Braz J Microbiol ; 54(1): 169-177, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36480120

RESUMO

INTRODUCTION: Psoriasis is a chronic inflammatory disease that affects over 125 million people worldwide. Many studies have shown the importance of the microbiome for psoriasis exacerbation. AIM: Explore the fungal load and species composition of cultivable yeasts on the skin of psoriatic patients (PP) and healthy volunteers living in a tropical area and evaluate the susceptibility to antifungals. METHODOLOGY: A cross-sectional study with 61 participants (35 patients and 26 healthy controls) was performed during August 2018 and May 2019. Clinical data were collected from patient interviewing and/or medical records review. Samples were collected by swabbing in up to five anatomic sites. Suggestive yeast colonies were counted and further identified by phenotypical tests, PCR-REA, and/or MALDI-TOF. Susceptibility of Malassezia spp. and Candida spp. to azoles, terbinafine, and amphotericin B was evaluated by broth microdilution. RESULTS: Nearly 50% of the patients had moderate to severe psoriasis, and plaque-type psoriasis was the most common clinical form. Yeast colonies count was significantly more abundant among PP than healthy controls. Malassezia and Candida were the most abundant genus detected in all participants. Higher MIC values for ketoconazole and terbinafine were observed in Malassezia strains obtained from PP. Approximately 42% of Candida isolates from PP showed resistance to itraconazole in contrast to 12.5% of isolates from healthy controls. MIC values for fluconazole and amphotericin B were significantly different among Candida isolates from PP and healthy individuals. CONCLUSION: This study showed that Malassezia and Candida strains from PP presented higher MIC values to widespread antifungal drugs than healthy individuals.


Assuntos
Malassezia , Psoríase , Humanos , Antifúngicos/farmacologia , Anfotericina B , Candida , Terbinafina , Estudos Transversais , Saccharomyces cerevisiae , Fluconazol , Itraconazol , Testes de Sensibilidade Microbiana , Farmacorresistência Fúngica
12.
Mem. Inst. Oswaldo Cruz ; 118: e220251, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1430848

RESUMO

Meningitis is a potentially life-threatening infection characterised by the inflammation of the leptomeningeal membranes. The estimated annual prevalence of 8.7 million cases globally and the disease is caused by many different viral, bacterial, and fungal pathogens. Although several genera of fungi are capable of causing infections in the central nervous system (CNS), the most significant number of registered cases have, as causal agents, yeasts of the genus Cryptococcus. The relevance of cryptococcal meningitis has changed in the last decades, mainly due to the increase in the number of people living with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and medications that impair the immune responses. In this context, coronavirus disease 19 (COVID-19) has also emerged as a risk factor for invasive fungal infections (IFI), including fungal meningitis (FM), due to severe COVID-19 disease is associated with increased pro-inflammatory cytokines, interleukin (IL)-1, IL-6, and tumour necrosis factor-alpha, reduced CD4-interferon-gamma expression, CD4 and CD8 T cells. The gold standard technique for fungal identification is isolating fungi in the culture of the biological material, including cerebrospinal fluid (CSF). However, this methodology has as its main disadvantage the slow or null growth of some fungal species in culture, which makes it difficult to finalise the diagnosis. In conclusions, this article, in the first place, point that it is necessary to accurately identify the etiological agent in order to assist in the choice of the therapeutic regimen for the patients, including the implementation of actions that promote the reduction of the incidence, lethality, and fungal morbidity, which includes what is healthy in the CNS.

13.
J Med Case Rep ; 16(1): 429, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36345027

RESUMO

BACKGROUND: Opportunistic infections are frequent in people living with the human immunodeficiency virus who either do not have access to antiretroviral therapy (ART) or use it irregularly. Tuberculosis is the most frequent infectious disease in PLHIV and can predispose patients to severe fungal infections with dire consequences. CASE PRESENTATION: We describe the case of a 35-year-old Brazilian man living with human immunodeficiency virus (HIV) for 10 years. He reported no adherence to ART and a history of histoplasmosis with hospitalization for 1 month in a public hospital in Natal, Brazil. The diagnosis was disseminated Mycobacterium tuberculosis infection. He was transferred to the health service in Recife, Brazil, with a worsening condition characterized by daily fevers, dyspnea, pain in the upper and lower limbs, cough, dysphagia, and painful oral lesions suggestive of candidiasis. Lymphocytopenia and high viral loads were found. After screening for infections, the patient was diagnosed with tuberculous pericarditis and esophageal candidiasis caused by Candida tropicalis. The isolated yeasts were identified using the VITEK 2 automated system and matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry. Antifungal microdilution broth tests showed sensitivity to fluconazole, voriconazole, anidulafungin, caspofungin, micafungin, and amphotericin B, with resistance to fluconazole and voriconazole. The patient was treated with COXCIP-4 and amphotericin deoxycholate. At 12 days after admission, the patient developed sepsis of a pulmonary focus with worsening of his respiratory status. Combined therapy with meropenem, vancomycin, and itraconazole was started, with fever recurrence, and he changed to ART and tuberculostatic therapy. The patient remained clinically stable and was discharged with clinical improvement after 30 days of hospitalization. CONCLUSION: Fungal infections should be considered in patients with acquired immunodeficiency syndrome as they contribute to worsening health status. When mycoses are diagnosed early and treated with the appropriate drugs, favorable therapeutic outcomes can be achieved.


Assuntos
Candidíase , Esofagite , Micoses , Pericardite Tuberculosa , Masculino , Humanos , Adulto , Fluconazol/uso terapêutico , Voriconazol/uso terapêutico , Pericardite Tuberculosa/complicações , Pericardite Tuberculosa/diagnóstico , Pericardite Tuberculosa/tratamento farmacológico , Candidíase/tratamento farmacológico , Micoses/tratamento farmacológico , Antifúngicos/uso terapêutico , Esofagite/tratamento farmacológico , HIV
15.
MycoKeys ; 91: 169-197, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36760892

RESUMO

In recent decades, commercial Eucalyptus plantations have expanded toward the warm and humid regions of northern and northeastern Brazil, where Calonectria leaf blight (CLB) has become the primary fungal leaf disease of this crop. CLB can be caused by different Calonectria species, and previous studies have indicated that Calonectria might have high species diversity in Brazil. During a disease survey conducted in three commercial plantations of Eucalyptus in northeastern Brazil, diseased leaves from Eucalyptus trees with typical symptoms of CLB were collected, and Calonectria fungi were isolated. Based on phylogenetic analyses of six gene regions (act, cmdA, his3, rpb2, tef1, and tub2) and morphological characteristics, two new species of Calonectria were identified. Five isolates were named as C.paragominensis sp. nov. and four were named as C.imperata sp. nov. The pathogenicity to Eucalyptus of both species was confirmed by fulfilling the Koch's postulates.

16.
Ecohealth ; 18(3): 383-396, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34709509

RESUMO

Studies on the microbiota of freshwater cetaceans are scarce and may provide important data on animal and environmental health. This study aimed to evaluate the antimicrobial susceptibility of Gram-negative bacteria recovered from two populations of free-ranging Amazon river dolphins (Inia geoffrensis). Twenty-one animals were captured and released, 13 from Negro River and 8 from Tapajós River, Brazil. Swab samples were obtained from the oral cavity, blowhole, genital opening and rectum and were cultured on MacConkey agar. Isolates were biochemically identified, and antimicrobial susceptibility was assessed by disk diffusion method. Overall, 132 isolates were recovered, of which 71 were recovered from animals from Negro River and 61 from Tapajós River. The most commonly recovered bacterial species were Enterobacter cloacae, Morganella morganii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Overall, 51.6% (63/122) of the isolates were not-susceptible (intermediate resistance and resistance), of which 28/122 (22.9%) were resistant to at least one antimicrobial. Cephalothin, cefuroxime and cefepime were the drugs to which more resistant and intermediate results were observed (P < 0.001). The results indicate that free-ranging Amazon river dolphins host resistant bacteria, contributing for their maintenance in the environment. This study highlights the importance of the One Health approach to monitor the emergence of antimicrobial resistance. Summary Gram-negative bacteria recovered from 21 free-ranging Amazon river dolphins (Inia geoffrensis) from the Negro River and the Tapajós River populations were evaluated for their antimicrobial susceptibility. Overall, 51.6% (63/122) of the isolates were not-susceptible (intermediate resistance and resistance), of which 28/122 (22.9%) were resistant to at least one antimicrobial. Cephalothin, cefuroxime and cefepime were the drugs to which more resistant and intermediate results were observed. Thus, free-ranging Amazon river dolphins, never treated with antimicrobials, host resistant bacteria, contributing for their maintenance in the environment and highlighting the importance of the One Health approach to monitor the emergence of antimicrobial resistance.


Assuntos
Golfinhos , Saúde Única , Animais , Antibacterianos/farmacologia , Bactérias , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana
17.
Front Cell Infect Microbiol ; 11: 642658, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34277464

RESUMO

Cryptococcosis is an infectious disease of worldwide distribution, caused by encapsulated yeasts belonging to the phylum Basidiomycota. The genus Cryptococcus includes several species distributed around the world. The C. gattii/neoformans species complex is largely responsible for most cases of cryptococcosis. However, clinical series have been published of infections caused by Papiliotrema (Cryptococcus) laurentii and Naganishia albida (Cryptococcus albidus), among other related genera. Here, we examined the pathogenic potential and antifungal susceptibility of C. gattii/neoformans species complex (clades I and II) and related genera (Papiliotrema and Naganishia) isolated from environmental and clinical samples. P. laurentii (clade III), N. liquefasciens/N. albidosimilis (clade IV); and N. adeliensis/N. albida (clade V) strains produced higher levels of phospholipase and hemolysins, whereas the C. gattii/neoformans species complex strains (clades I and II) had markedly thicker capsules, produced more biofilm biomass and melanin, which are known virulence attributes. Interestingly, 40% of C. neoformans strains (clade II) had MICs above the ECV established for this species to amphotericin B. Several non-C. gattii/neoformans species complex (clades III to V) had MICs equal to or above the ECVs established for C. deuterogattii and C. neoformans for all the three antifungal drugs tested. Finally, all the non-C. gattii/neoformans clinical isolates (clades III to V) produced more melanin than the environmental isolates might reflect their particularly enhanced need for melanin during in vivo protection. It is very clear that C. gattii/neoformans species complex (clades I and II) strains, in general, show more similar virulence phenotypes between each other when compared to non-C. gattii/neoformans species complex (clades III to V) isolates. These observations together with the fact that P. laurentii and Naganishia spp. (clades III to V) strains were collected from the outside of a University Hospital, identify features of these yeasts important for environmental and patient colonization and furthermore, define mechanisms for infections with these uncommon pathogens.


Assuntos
Basidiomycota , Cryptococcus gattii , Cryptococcus neoformans , Antifúngicos/farmacologia , Humanos , Virulência , Fatores de Virulência
19.
Rev. bras. anal. clin ; 53(2): 163-166, 20210630.
Artigo em Português | LILACS | ID: biblio-1349052

RESUMO

Os esforços envidados para o controle e extinção da pandemia do novo Coronavírus-2019 (COVID-19) não estão obtendo êxito, e já atingiram critérios epidemiológicos alarmantes, tendo infectado mais de dez milhões de pessoas no Brasil e mais de 100 milhões no mundo. A infecção por este vírus pode causar a síndrome respiratória aguda grave, com danos diretos ao epitélio das vias aéreas, permitindo a instalação de patógenos secundários de origem bacteriana e fúngica, como exemplo os fungos do gênero Aspergillus, que podem causar complicações nas manifestações clínicas e aumentar a taxa de mortalidade. Porém, mesmo com a alta probabilidade de infecção por estes fungos, verifica-se que são poucos os estudos direcionados a este assunto, como também, em alguns países, não há critério para identificar os fungos patógenos em geral, sendo possível que o verdadeiro número de coinfecções e a necessidade de internação em UTI seja maior. Portanto, neste artigo, revisamos estudos anteriores sobre a CAPA em bancos de dados eletrônicos e discutimos a necessidade do diagnóstico da aspergilose invasiva para aumento da sobrevida dos pacientes envolvidos. Neste trabalho recomendamos o diagnóstico correto e precoce das infecções fúngicas invasivas em pacientes com COVID-19, e que novos estudos sobre o tema sejam realizados para padronizar um diagnóstico eficaz e comprovado.


The new corona virus 2019 (COVID-19) is becoming unstoppable, and has already reached alarming epidemiological criteria, having infected more than 10,000,000 in Brazil and more than 100,000,000 worldwide. Infection with this virus can cause severe acute respiratory syndrome, which causes direct damage to the airway epithelium, allowing the invasion of secondary pathogens of bacterial and fungal origin, such as fungi of the genus Aspergillus, which can cause complications in clinical manifestations. and increase the mortality rate, however, even with the high probability of infection by these fungi, it appears that there are few studies directed to this subject, and also, in some countries there is no criterion to identify pathogenic fungi in general, it is possible that the true number of co-infections and the need for ICU admission is greater. Therefore, in this article, we reviewed previous studies on CAPA in electronic databases, and discussed the need for the diagnosis of invasive aspergillosis to increase the survival of the patients involved. Therefore, in this work, we recommend the correct and early diagnosis of invasive fungal infections in patients with COVID-19, and that further studies on the subject be carried out to standardize an effective and proven diagnosis.


Assuntos
Coronavirus , Erros de Diagnóstico , Aspergilose Pulmonar Invasiva , COVID-19
20.
Front Cell Infect Microbiol ; 11: 645812, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33968802

RESUMO

Persister cells are metabolically inactive dormant cells that lie within microbial biofilms. They are phenotypic variants highly tolerant to antimicrobials and, therefore, associated with recalcitrant infections. In the present study, we investigated if Trichosporon asahii and T. inkin are able to produce persister cells. Trichosporon spp. are ubiquitous fungi, commonly found as commensals of the human skin and gut microbiota, and have been increasingly reported as agents of fungemia in immunocompromised patients. Biofilms derived from clinical strains of T asahii (n=5) and T. inkin (n=7) were formed in flat-bottomed microtiter plates and incubated at 35°C for 48 h, treated with 100 µg/ml amphotericin B (AMB) and incubated at 35°C for additional 24 h. Biofilms were scraped from the wells and persister cells were assayed for susceptibility to AMB. Additionally, we investigated if these persister cells were able to generate new biofilms and studied their ultrastructure and AMB susceptibility. Persister cells were detected in both T asahii and T. inkin biofilms and showed tolerance to high doses of AMB (up to 256 times higher than the minimum inhibitory concentration). Persister cells were able to generate biofilms, however they presented reduced biomass and metabolic activity, and reduced tolerance to AMB, in comparison to biofilm growth control. The present study describes the occurrence of persister cells in Trichosporon spp. and suggests their role in the reduced AMB susceptibility of T. asahii and T. inkin biofilms.


Assuntos
Trichosporon , Antifúngicos , Basidiomycota , Biofilmes , Humanos , Testes de Sensibilidade Microbiana
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