ABSTRACT
Staphylococcus aureus es un patógeno responsable de diversos cuadros clínicos. Los marcadores moleculares son útiles para el estudio de la epidemiología microbiana. Se estudiaron 22 aislamientos de S. aureus resistentes a meticilina (SARM) y 23 sensibles a meticilina (SASM) mediante mecA, cassette SCCmec, leucocidina de Panton Valentine (LPV) y polimorfismo spa; se analizaron datos de los pacientes. SASM predominó en muestras distintas de piel y partes blandas de internados, mientras SARM en partes blandas. Predominó el SCCmec tipo IV seguido del I. Se encontró baja presencia de LPV. En SARM hubo 11 tipos de spa diferentes, t019 fue el más frecuente y en pacientes ambulatorios. En SASM se hallaron 17 tipos con prevalencia del t189. El spa t002 estuvo presente en SASM y SARM. Se hallaron 11 tipos de spa no reportados en nuestro país.
Staphylococcus aureus is a pathogen associated a different kind of infection. Molecular markers are useful tools to study microbial epidemiology. Twenty two methicillin-resistant S. aureus (MRSA) and 23 methicillin-susceptible S. aureus (MSSA) were studied by mecA gene, SCCmec cassette, Panton Valentine leucocidin (PVL) and spa polymorphism. The clinical data patients were analyzed. MSSA was prevalent in samples different from skin and soft tissue (SST) and in hospitalized patients, whereas MRSA in SST. SCCmec type IV was predominant, followed spa; by type I. Low presence of PVL was found. In MRSA 11 different types of spa were detected, SCCmec; t019 was the most frequent and associated with outpatient, 17 types were found in MSSA and Panton Valentine t189 was prevalent. spa t002 was present in MSSA and MRSA. We found 11 types of spa not leucocidin reported in our country.
Subject(s)
Adult , Humans , Staphylococcal Infections , Staphylococcus aureus , Methicillin-Resistant Staphylococcus aureus , Hospitals , Argentina , Bacterial Proteins , Bacterial Toxins , Microbial Sensitivity Tests , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/genetics , Anti-Bacterial AgentsABSTRACT
Candida africana taxonomical status is controversial. It was proposed as a separate species within the Candida albicans species complex; however, phylogenetic analyses suggested that it is an unusual variety of C. albicans. The prevalence of C. albicans-related species (Candida dubliniensis and C. africana) as vulvovaginal pathogens is not known in Argentina. Moreover, data on antifungal susceptibility of isolates causing vulvovaginal candidiasis is scarce. The aims of this study were to establish the prevalence of C. dubliniensis and C. africana in vaginal samples and to evaluate the antifungal susceptibilities of vaginal C. albicans species complex strains. We used a molecular-based method coupled with a new pooled DNA extraction methodology to differentiate C. dubliniensis and C. africana in a collection of 287 strains originally identified as C. albicans isolated from an Argentinian hospital during 2013. Antifungal susceptibilities to fluconazole, clotrimazole, itraconazole, voriconazole, nystatin, amphotericin B and terbinafine were evaluated by using the CLSI M27-A3 and M27-S4 documents. Of the 287 isolates, 4 C. dubliniensis and one C. africana strains (1.39% and 0.35% prevalence, respectively) were identified. This is the first description of C. africana in Argentina and its identification was confirmed by sequencing the ITS2 region and the hwp1 gene. C. dubliniensis and C. africana strains showed very low MIC values for all the tested antifungals. Fluconazole-reduced-susceptibility and azole cross-resistance were observed in 3.55% and 1.41% of the C. albicans isolates, respectively. These results demonstrate that antifungal resistance is still a rare phenomenon in this kind of isolates.
La clasificación taxonómica de Candida africana está en discusión, es considerada una nueva especie dentro del complejo C. albicans o una variedad inusual de C. albicans. La prevalencia de las especies relacionadas a C. albicans (C. dubliniensis y C. africana) como agentes de vulvovaginitis en Argentina se desconoce. Los objetivos de este trabajo fueron determinar la prevalencia de C. dubliniensis y C. africana en muestras vaginales y evaluar la sensibilidad a los antifúngicos de aislamientos vaginales de las especies del complejo C. albicans. Para diferenciar C. dubliniensis y C. africana utilizamos un método molecular asociado a un nuevo método de extracción de ADN. Se utilizó una colección de 287 cepas originalmente identificadas como C. albicans aisladas durante 2013 en un hospital de Argentina. Se evaluó la sensibilidad a fluconazol, clotrimazol, itraconazol, voriconazol, nistatina, anfotericina B y terbinafina utilizando los documentos M27-A3 y M27-S4 del CLSI. De los 287 aislamientos, se identificaron 4 C. dubliniensis y 1 C. africana (1,39 y 0,35% de prevalencia, respectivamente). Esta es la primera descripción de C. africana en Argentina. Su identificación fue confirmada por secuenciación de la región ITS2 y del gen hwp1. Las cepas identificadas como C. dubliniensis y C. africana mostraron valores de CIM muy bajos para todos los antifúngicos probados. En los aislamientos de C. albicans, la sensibilidad reducida al fluconazol y la resistencia cruzada a todos los azoles se observó en el 3,55% y el 1,41%, respectivamente. Estos resultados demuestran que la resistencia a los antifúngicos es todavía un fenómeno raro en este tipo de aislamientos.
Subject(s)
Humans , Female , Candida albicans/isolation & purification , Candida albicans/drug effects , Candidiasis, Vulvovaginal/drug therapy , Antifungal Agents/therapeutic use , Vulvovaginitis/microbiology , Candida albicans/classificationABSTRACT
We herein present the case of an adult male patient who consulted for lower extremity edema, a 2- month history of fever and oppressive chest pain radiating to the left arm. He referred neither contact with breeding animals nor consumption of unpasteurized dairy products. A diagnosis of endocarditis was confirmed by cardiac studies. Since the empirical treatment with cephalotin, ampicillin and gentamicin failed, the patient underwent aortic valve replacement. A total of four blood cultures were positive with a gram-negative rod. Bacterial identification was performed using the API 20 NE technique (bioMÞrieux), the Phoenix automated method (BD) and conventional biochemical tests which were unable to classify the isolate as to genus and species. The strain was sent to the INEI-ANLIS "Dr. Carlos G. Malbrán" where it was identified as Brucella canis. The antimicrobial treatment was switched to doxycycline, rifampicin and trimethoprim-sulfamethoxazole with good evolution of the patient. The clinical significance of this case report lies in the possible failure of the empiric antibiotic therapy administered for endocarditis, since B. canis did not respond to the conventional antimicrobial treatment for this pathology.
Subject(s)
Brucella canis/isolation & purification , Brucellosis/microbiology , Endocarditis, Bacterial/microbiology , Adult , Argentina/epidemiology , Bacteremia/microbiology , Brucella canis/drug effects , Brucellosis/surgery , Brucellosis/epidemiology , Brucellosis/drug therapy , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Chest Pain/etiology , Doxycycline/therapeutic use , Edema/etiology , Endocarditis, Bacterial/surgery , Endocarditis, Bacterial/epidemiology , Endocarditis, Bacterial/drug therapy , Drug Resistance, Multiple, Bacterial , Fever/etiology , Humans , Heart Valve Prosthesis Implantation , Male , Rifampin/therapeutic use , Combined Modality Therapy , Bacterial Typing Techniques , Aortic Valve/surgery , Aortic Valve/microbiologyABSTRACT
Se ha investigado, mediante estudios de cinética de muerte celular, el efecto inhibidor de una cepa de Lactobacillus casei, aislada de un alimento cárnico fermentado producido en la región santafesina (Argentina), y de su sobrenadante libre de células (SLC), frente a tres cepas de Escherichia coli O157:H7. La cepa de L. casei 206/1 se seleccionó sobre la base de resultados obtenidos en estudios previos donde, aplicando la técnica de agar spot, se determinó que su SLC produjo el mayor efecto inhibitorio sobre E. coli O157:H7. En los ensayos de cinética de muerte celular se observó una reducción significativa de las cepas de E. coli O157:H7 estudiadas, tanto en cocultivos como en el ensayo con el SLC, no detectándose bacterias viables luego de 24 horas de incubación. Estos resultados demuestran que cepas de bacterias ácido lácticas aisladas a partir de un determinado ecosistema regional, pueden convertirse en una herramienta biotecnológica útil para controlar a E. coli O157:H7 en alimentos.
Through the study of cell death kinetics, we have analyzed the inhibiting effect of a Lactobacillus casei strain isolated from a fermented meat product produced at the Santa Fe region in Argentina, and of its cell-free supernatant (CFS), against three Escherichia coli O157:H7 strains. The L. casei 206/1 strain was selected on the basis of results obtained in previous studies where using the agar spot technique, it was determined that CFS produced the greatest inhibitory effect over E. coli O157:H7. The studies of cell death kinetics showed a significant reduction of the E. coli O157:H7 strains tested, both in cocultures and in assays with CFS, and no viable bacteria were detected after 24-hours of incubation. These results show that lactic acid bacterial strains isolated from a determined regional ecosystem, can become a useful biotechnological tool for controlling E. coli O157:H7 in food.