Clostridioides difficile: Characterization of the circulating toxinotypes in an Argentinean public hospital / Clostridioides difficile: caracterización de los toxinotipos circulantes en un hospital público de Argentina

Abstract Clostridioides difficile is a spore-forming anaerobe microorganism associated to nosocomial diarrhea. Its virulence is mainly associated with TcdA and TcdB toxins, encoded by their respective tcdA and tcdB genes. These genes are part of the pathogenicity locus (PaLoc). Our aim was to characterize relevant C. difficile toxinotypes circulating in the hospital setting. The tcdA and tcdB genes were amplified and digested with different restriction enzymes: EcoRI for tcdA; HincII and AccI for tcdB. In addition, the presence of the cdtB (binary toxin) gene, TcdA and TcdB toxins by dot blot and the cytotoxic effect of culture supernatants on Vero cells, were evaluated. Altogether, these studies revealed three different circulating toxinotypes according to Rupnik's classification: 0, I and VIII, being the latter the most prevalent one. Even though more studies are certainly necessary (e.g. sequencing analysis), it is worth noting that the occurrence of toxinotype I could be related to the introduction of bacteria from different geographical origins. The multivariate analysis conducted on the laboratory values of individuals infected with the most prevalent toxinotype (VIII) showed that the isolates associated with fatal outcomes (GCD13, GCD14 and GCD22) are located in regions of the biplots related to altered laboratory values at admission. In other patients, although laboratory values at admission were not correlated, levels of urea, creatinine and white blood cells were positively correlated after the infection was diagnosed. Our study reveals the circulation of different toxinotypes of C. difficile strains in this public hospital. The variety of toxinotypes can arise from pre-existing microorganisms as well as through the introduction of bacteria from other geographical regions. The existence of microorganisms with different pathogenic potential is relevant for the control, follow-up, and treatment of the infections.

Resumen Clostridioides difficile es un anaerobio esporulado que se asocia con episodios de diarreas hospitalarias. Su virulencia se encuentra vinculada, principalmente, a las toxinas TcdA y TcdB, codificadas por sus respectivos genes, tcdA y tcdB, que son parte de un locus de patogenicidad (PaLoc). Nuestro objetivo fue caracterizar los toxinotipos de C. difficile circulantes en un hospital público. Los genes tcdA y tcdB fueron amplificados y digeridos con diferentes enzimas de restricción: EcoRI para tcdA; HincII y AccI para tcdB. Además, se evaluó la presencia de cdtB (gen de la toxina binaria B) y de las toxinas A y B (por dot blot), así como el efecto citotóxico de sobrenadantes de cultivo sobre células Vero. En conjunto, estos estudios revelaron tres toxinotipos circulantes según la clasificación de Rupnik: 0, I y VIII; el más prevalente fue el último. Aunque son necesarios más estudios (ej., secuenciación), es interesante notar que la presencia del toxinotipo I podría estar relacionada con la introducción de bacterias de diferente origen geográfico. En los pacientes infectados con el toxinotipo VIII, el análisis multivariante de los resultados de laboratorio mostró que los aislamientos asociados a decesos (GCD13, GCD14 y GCD22) estaban situados en regiones de los biplots relacionados con valores de laboratorio alterados al momento de la internación. En los otros pacientes, aunque no se observó correlación entre los valores de laboratorio al momento de la internación y la evolución clínica, los niveles de urea, creatinina y recuento de glóbulos blancos estuvieron correlacionados positivamente entre sí una vez diagnosticada la infección. Nuestro estudio revela la circulación de diferentes toxinotipos de C. difficile en un mismo hospital público. La variedad de toxinotipos puede originarse a partir de microorganismos preexistentes en la región, así como también por la introducción de bacterias provenientes de otras regiones geográficas. La existencia de microorganismos con diferente potencial patogénico es relevante para el control, el seguimiento y el tratamiento de las infecciones.

Clostridioides difficile: Characterization of the circulating toxinotypes in an Argentinean public hospital.

Clostridioides difficile is a spore-forming anaerobe microorganism associated to nosocomial diarrhea. Its virulence is mainly associated with TcdA and TcdB toxins, encoded by their respective tcdA and tcdB genes. These genes are part of the pathogenicity locus (PaLoc). Our aim was to characterize relevant C. difficile toxinotypes circulating in the hospital setting. The tcdA and tcdB genes were amplified and digested with different restriction enzymes: EcoRI for tcdA; HincII and AccI for tcdB. In addition, the presence of the cdtB (binary toxin) gene, TcdA and TcdB toxins by dot blot and the cytotoxic effect of culture supernatants on Vero cells, were evaluated. Altogether, these studies revealed three different circulating toxinotypes according to Rupnik's classification: 0, I and VIII, being the latter the most prevalent one. Even though more studies are certainly necessary (e.g. sequencing analysis), it is worth noting that the occurrence of toxinotype I could be related to the introduction of bacteria from different geographical origins. The multivariate analysis conducted on the laboratory values of individuals infected with the most prevalent toxinotype (VIII) showed that the isolates associated with fatal outcomes (GCD13, GCD14 and GCD22) are located in regions of the biplots related to altered laboratory values at admission. In other patients, although laboratory values at admission were not correlated, levels of urea, creatinine and white blood cells were positively correlated after the infection was diagnosed. Our study reveals the circulation of different toxinotypes of C. difficile strains in this public hospital. The variety of toxinotypes can arise from pre-existing microorganisms as well as through the introduction of bacteria from other geographical regions. The existence of microorganisms with different pathogenic potential is relevant for the control, follow-up, and treatment of the infections.

Efecto inhibitorio del dietilestilbestrol sobre aislamientos clínicos de Candida albicans sensibles y resistentes a los azoles / Inhibitory effect of diethylstilbestrol on clinical strains of Candida albicans susceptible and resistant to azoles

Antecedentes: Candida albicans es uno de los microorganismos más frecuentemente involucrados en diversas infecciones; la cavidad bucal del paciente, los nichos de caries o la enfermedad periodontal pueden actuar en ocasiones como reservorio. El desarrollo de resistencia a los medicamentos disponibles y otros factores justifican la búsqueda de nuevos antimicóticos. Objetivos: Estudiar de forma comparativa los efectos in vitro del medicamento antitumoral dietilestilbestrol (DES) y del fluconazol (FLZ) sobre el crecimiento de cepas clínicas de C. albicans aisladas de pacientes con enfermedades odontológicas y médicas. Métodos: Se emplearon siete cepas de C. albicans: a) la cepa de colección ATCC 90028, sensible a FLZ (ATCC); b) cuatro aislamientos bucales de sendas pacientes oncológicas con enfermedad periodontal (period 8, 9, 10 y 11); y c) dos aislamientos bucales de un paciente con sida y candidiasis orofaríngea: un aislamiento era sensible a FLZ (2-76) y el otro resistente (12-99). Se evaluó el crecimiento celular por técnicas espectrofotométricas estandarizadas (M27-A3, CLSI) y se calculó la concentración inhibitoria 50% (CI50) por análisis de funciones mediante el programa Graph Pad. Resultados: El DES inhibió el crecimiento de C. albicans, tanto sensible como resistente al FLZ. Los datos se ajustan adecuadamente a curvas teóricas saturables de tipo concentración del inhibidor versus respuesta. Las concentraciones inhibitorias mínimas fueron con DES y FLZ, respectivamente, las siguientes: 28,18µg/ml y 4,90µg/ml (ATCC); 17,16µg/ml y 3,14µg/ml (period); 27,64µg/ml y 4,22µg/ml (2-76); 6,16µg/ml y 438,19µg/ml (12-99). Conclusiones: El DES tiene actividad antimicótica sobre aislamientos de C. albicans de pacientes con enfermedades odontológicas y médicas. La mayor potencia antimicótica observada fue sobre el aislamiento resistente al FLZ

Background: Candida albicans is a microorganism frequently involved in several infections; the patient's oral cavity, caries niches or periodontal disease can sometimes be the reservoir.. The fungal resistance to the available treatments, among other reasons, has led to the search for new antifungal alternatives. Aims: To carry out a comparative study of the in vitro effects of diethylstilboestrol (DES) and fluconazole (FLZ) on the growth of clinical strains of C. albicans. Methods: Seven strains of C. albicans were used: a) one FLZ-sensitive culture collection strain, ATCC 90028 (ATCC); b) four oral isolates from four oncological patients with periodontal disease (period 8, 9, 10, and 11); and c) two oral isolates from an AIDS patient with oropharyngeal candidiasis: one FLZ- sensitive (2-76), and another FLZ- resistant (12-99). The MIC was evaluated by standard spectrophotometric techniques using the CLSI (M27-A3) guidelines. The inhibitory concentration 50% (IC50) was calculated using functional analysis with the Graph Pad software. Results: DES inhibited the growth of all C. albicans strains, whether sensitive or resistant to FLZ. Experimental data fitted non-linear functions of inhibitor concentration versus response. Minimum inhibitory concentrations (MIC) for DES and FLZ were as follows: 28.18µg/ml and 4.90µg/ml (ATCC); 17.16µg/ml and 3.14µg/ml (period); 27.64µg/ml and 4.22µg/ml (2-76); 6.16µg/ml and 438.19µg/ml (12-99), respectively. Conclusions: DES showed antifungal activity on all clinical C. albicans strains isolated from patients with dental and medical diseases. It showed the highest potency on the FLZ-resistant isolate

[Inhibitory effect of diethylstilbestrol on clinical strains of Candida albicans susceptible and resistant to azoles]. / Efecto inhibitorio del dietilestilbestrol sobre aislamientos clínicos de Candida albicans sensibles y resistentes a los azoles.

BACKGROUND: Candida albicans is a microorganism frequently involved in several infections; the patient's oral cavity, caries niches or periodontal disease can sometimes be the reservoir.. The fungal resistance to the available treatments, among other reasons, has led to the search for new antifungal alternatives. AIMS: To carry out a comparative study of the in vitro effects of diethylstilboestrol (DES) and fluconazole (FLZ) on the growth of clinical strains of C. albicans. METHODS: Seven strains of C. albicans were used: a) one FLZ-sensitive culture collection strain, ATCC 90028 (ATCC); b) four oral isolates from four oncological patients with periodontal disease (period 8, 9, 10, and 11); and c) two oral isolates from an AIDS patient with oropharyngeal candidiasis: one FLZ- sensitive (2-76), and another FLZ- resistant (12-99). The MIC was evaluated by standard spectrophotometric techniques using the CLSI (M27-A3) guidelines. The inhibitory concentration 50% (IC50) was calculated using functional analysis with the Graph Pad software. RESULTS: DES inhibited the growth of all C. albicans strains, whether sensitive or resistant to FLZ. Experimental data fitted non-linear functions of inhibitor concentration versus response. Minimum inhibitory concentrations (MIC) for DES and FLZ were as follows: 28.18µg/ml and 4.90µg/ml (ATCC); 17.16µg/ml and 3.14µg/ml (period); 27.64µg/ml and 4.22µg/ml (2-76); 6.16µg/ml and 438.19µg/ml (12-99), respectively. CONCLUSIONS: DES showed antifungal activity on all clinical C. albicans strains isolated from patients with dental and medical diseases. It showed the highest potency on the FLZ-resistant isolate.

Effects of tamoxifen on periodontal disease and Candida albicans of patients with breast cancer and other pathologies.

Candida albicans is involved in periodontal disease, which is influenced by sex hormones. AIM: To study the effects of the estrogen antagonist tamoxifen (TAM) on periodontal disease of oncological patients; clinical oral strains of C. albicans. PATIENTS: With periodontitis and breast cancer and other with AIDS were used. MATERIALS & METHODS: Periodontal disease was evaluated by the academy of periodontology procedures and the growth of clinical C. albicans isolates were evaluated by the Clinical and Laboratory Standards Institute techniques. RESULTS: Women who consumed TAM for more than 2 years decreased periodontitis severity. In vitro, TAM inhibited the growth of both fluconazole-sensitive and resistant C. albicans. CONCLUSION: Administered TAM chronically improves periodontal health and has antifungal activity on oral strains isolated from patients with odontologic and medical pathologies.

Spread of Clonally Related Escherichia coli Strains Harboring an IncA/C1 Plasmid Encoding IMP-8 and Its Recruitment into an Unrelated MCR-1-Containing Isolate.

Ten IMP-8-producing Escherichia coli isolates were recovered from surveillance cultures of a neonatal intensive care unit; eight of the isolates were clonally related. A 168.2-kb blaIMP-8 plasmid was fully sequenced, and it corresponded to the recently described IncA/C1-ST13 plasmid. This plasmid was detected in all isolates, even in those that were not clonally related. One unrelated isolate was also resistant to colistin and positive for mcr-1 This marker was located in a 62.7-kb IncI2 plasmid, which was also fully sequenced.

Genetic-relatedness of peri-implants and buccal Candida albicans isolates determined by RAPD-PCR.

Molecular techniques have been used in recent studies to identify a wide range of potential bacterial pathogens in periimplant pockets of the oral cavity. However, the prevalence and molecular epidemiology of yeasts and species distribution related to periimplantitis are as yet unknown. The aim of this study was to determine the prevalence and distribution of yeasts in periimplant biofilm and to study genetic relatedness of Candida albicans. Yeasts recovered from periimplant biofilm samples (n=89) and buccal samples (n=120) were studied in 40 immunocompetent nonsmoking patients who visited the dental clinic of the Asociación Implantodontológica Argentina, Buenos Aires, Argentina, and had received oral rehabilitation with implants for more than five years. Yeasts recovered from samples were studied by typing assays using RAPDPCR. The prevalence of yeasts in the periimplant sulcus was 73% (n=29). C. albicans was the most prevalent species identified in this study population. The RAPD analysis showed identical genotypes in most C. albicans spp. from the two different sampling sites: buccal and periimplant. These findings suggest that periimplant biofilm is an ecological niche that favors the growth of yeast species. Most C. albicans found in periimplant biofilm originate from the endogenous infection caused by commensal strains.

Las técnicas moleculares se han utilizado en estudios recientes para identificar una gran diversidad de patógenos bacterianos de surcos periimplantarios de cavidad bucal. Sin embargo, la prevalencia y epidemiología molecular de especies de levaduras en relación con la periimplantitis son aún desconocidas. El objetivo de este estudio fue determinar la prevalencia y distribución de las levaduras en la biopelícula periimplantaria y estudiar la relación genética de Candida albicans. Se estudiaron 40 pacientes inmunocompetentes no fumadores que se asistieron en la clínica dental de la Asociación Implantodontológica Argentina, Buenos Aires, Argentina, y que habían recibido rehabilitación oral con implantes durante más de cinco años. Las levaduras aisladas de las muestras de biopelícula periimplantaria (n = 89) y bucales (n = 120), fueron identificadas por métodos micológicos tradicionales y moleculares. Se obtuvo el ADN de C. albicans y se realizaron estudios moleculares por RAPD PCR. La prevalencia de levaduras en el surco alrededor del implante fue de 73 % (n = 29). C. albicans fue la especie más frecuente identificada en esta población de estudio. El análisis RAPD permitió identificar idénticos genotipos de C. albicans en ambos nichos ecológicos estudiados, periimplantar y bucal. Según los resultados obtenidos, el surco periiplantario es un nicho ecológico que favorece el crecimiento de especies de levaduras del género Candida. La mayoría de los aislamientos de C. albicans periimplantarios se originan a partir de la infección endógena causada por cepas comensales.

Genetic-relatedness of peri-implants and buccal Candida albicans isolates determined by RAPD-PCR / Relación genética de aislamentos de candida albicans por rapd-pcr en surcos en surcos peri-implantarios de cavidad bucal

Molecular techniques have been used in recent studies toidentify a wide range of potential bacterial pathogens inperi­implant pockets of the oral cavity. However, the prevalence and molecular epidemiology of yeasts and species distribution related to peri­implantitis are as yet unknown. The aim of thisstudy was to determine the prevalence and distribution of yeasts in peri­-implant biofilm and to study genetic relatedness of Candida albicans.Yeasts recovered from peri­implant biofilm samples (n=89) andbuccal samples (n=120) were studied in 40 immunocompetent non­-smoking patients who visited the dental clinic of the Asociación Implantodontológica Argentina, Buenos Aires, Argentina, and had received oral rehabilitation with implants for more than five years. Yeasts recovered from samples were studied by typing assays using RAPD­PCR. The prevalence of yeasts in the peri­implant sulcus was 73% (n=29). C. albicans was the most prevalent species identified in this study population. The RAPD analysis showed identical genotypes inmost C. albicans spp. from the two different sampling sites: buccal and peri­implant. These findings suggest that periimplant biofilm is an ecological niche that favors the growth of yeast species. Most C. albicans found in peri­implant biofilmoriginate from the endogenous infection caused by commensalstrains.

Las técnicas moleculares se han utilizado en estudios recientespara identificar una gran diversidad de patógenos bacterianosde surcos periimplantarios de cavidad bucal. Sin embargo, laprevalencia y epidemiología molecular de especies de levadurasen relación con la periimplantitis son aún desconocidas. Elobjetivo de este estudio fue determinar la prevalencia ydistribución de las levaduras en la biopelícula periimplantaria yestudiar la relación genética de Candida albicans. Se estudiaron40 pacientes inmunocompetentes no fumadores que se asistieronen la clínica dental de la Asociación ImplantodontológicaArgentina, Buenos Aires, Argentina, y que habían recibidorehabilitación oral con implantes durante más de cinco años.Las levaduras aisladas de las muestras de biopelículaperiimplantaria (n = 89) y bucales (n = 120), fueron identificadaspor métodos micológicos tradicionales y moleculares. Se obtuvoel ADN de C. albicans y se realizaron estudios moleculares porRAPD ­PCR. La prevalencia de levaduras en el surco alrededordel implante fue de 73 % (n = 29). C. albicans fue la especie másfrecuente identificada en esta población de estudio. El análisisRAPD permitió identificar idénticos genotipos de C. albicans enambos nichos ecológicos estudiados, periimplantar y bucal.Según los resultados obtenidos, el surco periiplantario es unnicho ecológico que favorece el crecimiento de especies delevaduras del género Candida. La mayoría de los aislamientosde C. albicans periimplantarios se originan a partir de lainfección endógena causada por cepas comensales.

Rapid identification of Histoplasma capsulatum directly from cultures by multiplex PCR.

The multiplex PCR developed from a suspension of the yeast fungi correctly identified fifty-one clinical of H. capsulatum var. capsulatum strains isolated from clinical samples and soil specimens. The multiplex PCR was developed by combining two pairs of primers, one of them was specific to the H. capsulatum and the other one, universal for fungi, turned out to be specific to H. capsulatum, regardless of the fungus isolate studied. Primers designed to amplify a region of about 390-bp (Hc I-Hc II) and a region of approximately 600-bp (ITS1-ITS4) were used to identify a yeast isolated as H. capsulatum when both regions could be amplified. Absolute agreement (100 % sensitivity) could be shown between this assay and the cultures of H. capsulatum according to their morphological characteristics. Failure to amplify the target DNA sequence by PCR with primers Hc I-Hc II in the presence of the ITS1-ITS4 amplicon in isolates of P. brasiliensis, Cryptococcus neoformans, Trichosporon spp, Candida glabrata, C. albicans, C. tropicalis, C. parapsilosis, C. krusei, or Penicillium marneffei was an unequivocal sign of the high specificity of this assay. The assay specificity was also found to be 100 %. Incipient yeast forms obtained from clinical samples were identified as H. capsulatum by the PCR assay described before the morphological characteristics were registered shortening the time of diagnosis.

Nasal carriage of Staphylococcus aureus and Candida species in immunocompetent individuals.

The aim of this study was to analyze the prevalence of Staphylococcus aureus and Candida species in samples of nasal mucosa from 100 immunocompetent subjects of both sexes, aged 18-70 years, during stomatological clinical examination. Samples were taken from the mucosa of both nasal fossae using sterile swabs. Samples were observed fresh, stained with Gram and Giemsa, and cultured on selective differential media at 37 degrees C to isolate and identify the selected microorganisms; conventional biochemical tests and commercial equipment and molecular studies using PCR were performed. A digital thermometer-hygrometer was used to measure room temperature at the time of sampling, which was on average 25 +/- 2 degrees C, with relative ambient humidity 66 +/- 11%. S. aureus was isolated from 38% of the samples; 4% of the samples were methicillin-resistant (MRSA) strains, with 2% identified genetically as community-acquired (CA-MRSA) and 2% as hospital-acquired (HA-MRSA). Candida was identified in 23% of the samples, with prevalence of C. albicans (19%) followed by C. dubliniensis (3%) and C. krusei (1%). There was significant association between Candida and S. aureus (Chi-squared = 27.75; df = 1; (p < 0.001). The nasal cavity is a reservoir and the identification of genus and species contributes to adequate epidemiological surveillance.

Nasal carriage of Staphylococcus aureus and Candida species in immunocompetent individuals

El propósito de este trabajo fue analizar la prevalencia de Staphylococcus aureus y especies de Candida en muestras demucosa nasal de 100 individuos inmunocompetentes de ambos sexos con edades entre 18-70 años, durante el examen clínico estomatológico. Las muestras fueron obtenidas con hisoposestériles sobre la mucosa de ambas fosas nasales. Se realizó observación en fresco, tinción de Gram, Giemsa y cultivos en medios selectivos y diferenciales a 37ºC para el aislamiento e identificación de los microorganismos seleccionados, pruebas bioquímicas convencionales y equipos comerciales y estudios moleculares mediante la prueba de PCR. Con un termo higrómetro digital se midió la temperatura ambiente cuyo promedio en el momento de la toma en el consultoriofue de 25±2 oC y la humedad relativa ambiente fue del 66±11 por ciento.S aureus se aisló en el 38 por ciento de las muestras y dentro del mismo, 4 por ciento fueron meticilino resistentes (MRSA) siendo genéticamente 2 por ciento de la Comunidad (MRSA-CA) y 2 por ciento Hospitalarios (MRSA-HA).En el 23 por ciento de las muestras fue identificada Candida siendo la especie prevalente C. albicans: 19 por ciento y en menor proporción C. dubliniensis: 3 opr ciento , C. krusei: 1 por ciento. Se registró una asociación significativa entre Candida y S. aureus (Chi-cuadrado=27,75; gl=1; (p<0,001). La cavidad nasal constituye un reservorio yla identificación de género y especie contribuye a la adecuada vigilancia epidemiológica.(AU)

Nasal carriage of Staphylococcus aureus and Candida species in immunocompetent individuals

El propósito de este trabajo fue analizar la prevalencia de Staphylococcus aureus y especies de Candida en muestras demucosa nasal de 100 individuos inmunocompetentes de ambos sexos con edades entre 18-70 años, durante el examen clínico estomatológico. Las muestras fueron obtenidas con hisoposestériles sobre la mucosa de ambas fosas nasales. Se realizó observación en fresco, tinción de Gram, Giemsa y cultivos en medios selectivos y diferenciales a 37ºC para el aislamiento e identificación de los microorganismos seleccionados, pruebas bioquímicas convencionales y equipos comerciales y estudios moleculares mediante la prueba de PCR. Con un termo higrómetro digital se midió la temperatura ambiente cuyo promedio en el momento de la toma en el consultoriofue de 25±2 oC y la humedad relativa ambiente fue del 66±11 por ciento.S aureus se aisló en el 38 por ciento de las muestras y dentro del mismo, 4 por ciento fueron meticilino resistentes (MRSA) siendo genéticamente 2 por ciento de la Comunidad (MRSA-CA) y 2 por ciento Hospitalarios (MRSA-HA).En el 23 por ciento de las muestras fue identificada Candida siendo la especie prevalente C. albicans: 19 por ciento y en menor proporción C. dubliniensis: 3 opr ciento , C. krusei: 1 por ciento. Se registró una asociación significativa entre Candida y S. aureus (Chi-cuadrado=27,75; gl=1; (p<0,001). La cavidad nasal constituye un reservorio yla identificación de género y especie contribuye a la adecuada vigilancia epidemiológica.

Prevalence of Candida species in necrotic pulp with chronic periapical processes.

The aim of this study was to identify species of the genus Candida in mucosa of oral cavity and in single-rooted teeth with pulp necrosis with chronic endodontic periapical processes, with radiographic images 2+/-4 mm and without clinical symptomatology, in immunocompetent patients. The study included 82 immunocompetent patients of both sexes aged 18-70 years with a clinical dental diagnosis of septic pulp necrosis. Samples were taken from root canals with sterile # 25 paper points and from oral mucosa with a sterile swab. Seven different Candida species were identified (C. albicans, C. dubliniensis, C. guilliermondii, C. krusei, C. parapsilopsis, C. tropicalis and C. glabrata). All of them were present in oral mucosa, while two of them (C. parapsilopsis and C. glabrata) were not identified in the periapical zone of necrotic canals. Considering all the samples isolated from oral mucosa, there was a significantly greater frequency of C. albicans than there was in the periapical zone of necrotic canals.

Antibiotic susceptibility of Staphylococcus aureus isolates in oral mucosa and pockets of patients with gingivitis-periodontitis.

Both oral cavity and subgingival pocket are ecological niches conducive to hosting microorganisms that may act as opportunistic pathogens, such as Staphylococcus aureus and especially methicillin-resistant Staphylococcus aureus (MRSA). Early detection of MRSA is a matter of concern to Public Health. The aim of our study was to determine phenotypic and genotypic detection of methicillin resistance of S. aureus in oral mucosa and subgingival pocket in 102 patients with gingivitis-periodontitis. The prevalence of S. aureus was 10.8% (n = 11) in subgingival pocket and 19.6% (n = 20) in oral mucosa. We obtained 31 isolates of S. aureus of which 13 were mecA positive and 18 were mecA negative. Detection of mecA gene by PCR was used as the reference method to compare the results of phenotypic methods to determine methicillin resistance. Early, accurate detection of S. aureus through phenotyping and genotyping methods is crucial for assessing the colonization and preventing the spread of MRSA.

Prevalence of Candida species in necrotic pulp with chronic periapical processes

El propósito de este estudio fue identificar especies del géneroCandida en mucosa de cavidad bucal y dientes unirradiculares con necrosis pulpar con procesos periapicales crónicos de origen endodóntico con imágenes radiográficas entre 2±4 mm sin sintomatología clínica en pacientes inmunocompetentes. El estudio incluyó 82 pacientes inmunocompetentes de ambos sexos con edades entre 18-70 años con diagnóstico clínico dentario de necrosis pulpar séptica. Las muestras fueron obtenidas del conducto radicular con conos de papel estéril # 25 y de lamucosa bucal mediante hisopo estéril. Se identificaron 7 especies diferentes de Candida (C. albicans, C. dubliniensis,C. guilliermondii, C. krusei, C. arapsilopsis, C. tropicalis y C. glabrata). Todas estuvieron presentes en mucosa bucal, mientras que dos de ellas (C. parapsilopsis y C. glabrata) nose identificaron en zona periapical de conductos con necrosis Del total de las muestras aisladas de mucosa bucal hubo una frecuencia significativamente mayor de C. albicans que la proporción de estas levaduras en la zona periapical en conductos con necrosis.

Prevalence of Staphylococcus spp and Candida spp in the oral cavity and periodontal pockets of periodontal disease patients.

The oral cavity can act as a reservoir of certain pathogens that can cause systemic infections. The periodontal pocket is an ecological niche appropriate for hosting microorganisms that could act as opportunistic pathogens. The ability of Staphylococcus spp and Candida spp to form a biofilm and live within certain niches allows them to develop mechanisms that increase persistence, such as the evasion of host defenses and antibiotic efficacy. These microorganisms can easily be or become resistant to antibiotics and lead to superinfection. The aims of this study were to assess the presence of Staphylococcus aureus and Staphylococcus spp in biofilm in subgingival plaque and oral cavity of individuals with gingival-periodontal disease, to identify isolates and the relationship with Candida spp. The study included eighty-two patients, aged 18-70 years with periodontal disease and at least two sites with probing depth > or = 3 mm. Participants' data were evaluated individually. Subgingival biofilm samples were obtained using Gracey curettes 7/8, after supragingival biofilm removal, and a sample from the oral cavity (buccal mucosa, tongue and cheek mucosa) by sterile swab. Of all the patients studied, 42.7% exhibited Staphylococcus spp in the periodontal pocket and 69.5% in the oral cavity while 25.6% exhibited Candida spp in the periodontal pocket and 42.7% in the oral cavity. However, 13.4% had both microorganisms in the periodontal pocket and 36.6% in the oral cavity. The prevalence of Staphylococcus aureus was 13.4% in the periodontal pocket and 15.8% in the oral cavity. Candida albicans was the most prevalent yeast in the periodontal pocket (76.2%) and in the oral cavity (63.0%).

Prevalence of Staphylococcus spp and Candida spp in the oral cavity and periodontal pockets of periodontal disease patients

The oral cavity can act as a reservoir of certain pathogens that can cause systemic infections. The periodontal pocket is an ecological niche appropriate for hosting microorganisms that could act as opportunistic pathogens. The ability of Staphylococcus spp and Candida spp to form a biofilm and live within certain niches allows them to develop mechanisms that increase persistence, such as the evasion of host defenses and antibiotic efficacy. These microorganisms can easily be or become resistant to antibiotics and lead to superinfection. The aims of this study were to assess the presence of Staphylococcus aureus and Staphylococcus spp in biofilm in subgingival plaque and oral cavity of individuals with gingival-periodontal disease, to identify isolates and the relationship with Candida spp. The study included eighty-two patients, aged 18-70 years with periodontal disease and at least two sites with probing depth ≥3 mm. Participants’ data were evaluated individually. Subgingival biofilm samples were obtained using Gracey curettes 7/8, after supragingival biofilm removal, and a sample from the oral cavity (buccal mucosa, tongue and cheek mucosa) by sterile swab. Of all the patients studied, 42.7% exhibited Staphylococcus spp in the periodontal pocket and 69.5% in the oral cavity while 25.6% exhibited Candida spp in the periodontal pocket and 42.7% in the oral cavity. However, 13.4% had both microorganisms in the periodontal pocket and 36.6% in the oral cavity. The prevalence of Staphylococcus aureus was 13.4% in the periodontal pocket and 15.8% in the oral cavity. Candida albicans was the most prevalent yeast in the periodontal pocket (76.2%) and in the oral cavity (63.0%).

La cavidad bucal puede actuar como reservorio de ciertos patógenos que pueden producir infecciones sistémicas. La bolsa periodontal es un nicho ecológico propicio para albergar microorganismos que podrian actuar como patógenos oportunistas. La posibilidad que Staphylococcus spp y Candida spp puedan formar un biofilm o biopelícula y vivir dentro de ciertos nichos les permite a estos microorganismos desarrollar ciertos mecanismos que aumentan su persistencia como ser la capacidad de eludir las defensas del huésped y la terapia antimicrobiana. Estos microorganismos pueden ser o fácilmente convertirse en resistentes a los antibióticos y dar origen a una supeinfección. El propósito de este estudio fue evaluar la presencia de Staphylococcus aureus y Staphylococcus spp en biofilm placa subgingival y en cavidad oral en sujetos con enfermedad gingivoperiodontal, identificar los microorganismos aislados y su relación con la portación de Candida spp. El estudio incluyo ochenta y dos pacientes, de edades entre 18 a 70 anos de edad, con enfermedad periodontal, y al menos dos sitios con la profundidad de sondaje ≥ 3 mm. Se evaluaron los datos individuales. Las muestras de biofilm subgingival fueron obtenidas con cureta tipo Gracey 7/8, previa remoción del biofilm supragingival y una muestra de cavidad oral (mucosa, lengua y carrillo) mediante hisopo estéril. Del total de los pacientes estudiados, el 42,7% mostraron Staphylococcus spp en la bolsa y el 69,5% en la cavidad oral, mientras que 25,6% mostraron Candida spp en la bolsa y 42,7% en la cavidad oral. Sin embargo, el 13,4% tenían ambos microorganismos en la bolsa y el 36,6% en la cavidad oral. La prevalencia de Staphylococcus aureus en la bolsa periodontal fue de 13,4% y 15,8% en la cavidad oral. Candida albicans fue la levadura más frecuente en la bolsa periodontal (76,2%) y en la cavidad oral (63,0%).

Phenotypic and genotypic characterization of Aspergillus lentulus and Aspergillus fumigatus isolates in a patient with probable invasive aspergillosis.

Characteristic morphological and phylogenetic analyses demonstrated the presence of Aspergillus fumigatus and Aspergillus lentulus as the aetiological agents in a case of probable invasive aspergillosis (IA). This is believed to be the first report of an A. lentulus strain isolated from a patient with probable IA in Argentina.

Genetic relatedness of subgingival and buccal Candida dubliniensis isolates in immunocompetent subjects assessed by RAPD-PCR.

BACKGROUND: It is recognized that Candida dubliniensis commonly colonizes oral and subgingival sites in immunocompetent subjects with periodontal disease. OBJECTIVE: Since there are few data available on genetic characterization of C. dubliniensis in periodontal pockets and other oral sites, the aim of this study was to characterize subgingival and mucosal C. dubliniensis isolates recovered from immunocompetent subjects and to assay the genetic similarity of such isolates from both niches in the same patient by random amplified polymorphic DNA (RAPD). DESIGN: C. dubliniensis recovered from subgingival plaque and from buccal cavity samples were studied in 240 immunocompetent non-smoking individuals. Arbitrary amplification was carried out by RAPD-polymerase chain reaction (PCR). RESULTS: RAPD analysis showed identical genotypes of C. dubliniensis in different sampling sites (buccal cavity and subgingival areas) in eight of 10 patients except for those derived from two participants who presented presumably unrelated isolates. CONCLUSIONS: On the basis of the findings presented, the origin of the colonization of C. dubliniensis in subgingival biofilm seems to be the buccal cavity in a single patient. Consequently, it may be assumed that most of C. dubliniensis in these sites arise from the endogenous commensal strains.