Paulo Roberto da Silva

Formigas como vetores mecânicos de microorganismos no Hospital Escola da Universidade Federal do Triângulo Mineiro

The pathogens associated with ants at the teaching hospital of the Federal University of the Triângulo Mineiro, in Uberaba, MG, were studied. Three species of ants were identified: Tapinoma melanocephalum, Pheidole sp and Paratrechina longicornis. The principal microorganisms found were Staphylococcus sp, Gram-positive bacilli, Pseudomonas sp and Micrococcus sp. The results from the collections were analyzed according to the number of colonies and the different microorganisms isolated, using Students t test. The statistical analysis showed that there was a significant difference only with regard to Staphylococcus sp. (p =0.005). It is possible that ants and pathogenic agents have mutualistic associations, and that analysis of such relationships may lead to new pest control strategies, with an emphasis not only on the insects but also especially on which agent is associated with these insect species.

Trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital: a 4-year study

INTRODUCTION In the past two decades members of the genus Enterococcus have emerged as important nosocomial pathogens worldwide. This study prospectively analyzed the distribution of species and trends in antimicrobial resistance among clinical isolates of enterococci in a Brazilian tertiary hospital from 2006-2009. METHODS Enterococcal species were identified by conventional biochemical tests. The antimicrobial susceptibility profile was performed by disk diffusion in accordance with the Clinical and Laboratory Standards Institute (CLSI). A screening test for vancomycin was also performed. Minimal inhibitory concentration (MIC) for vancomycin was determined using the broth dilution method. Molecular assays were used to confirm speciation and genotype of vancomycin-resistant enterococci (VRE). RESULTS A total of 324 non-repetitive enterococcal isolates were recovered, of which 87% were E. faecalis and 10.8% E. faecium. The incidence of E. faecium per 1,000 admissions increased significantly (p < 0.001) from 0.3 in 2006 to 2.3 in 2009. The VRE rate also increased over time from 2.5% to 15.5% (p < 0.001). All VRE expressed high-level resistance to vancomycin (MIC >256 µg/ mL) and harbored vanA genes. The majority (89.5%) of VRE belonged to E. faecium species, which were characteristically resistant to ampicillin and quinolones. Overall, ampicillin resistance rate increased significantly from 2.5% to 21.4% from 2006-2009. Resistance rates for gentamicin, chloramphenicol, tetracycline, and erythromycin significantly decreased over time, although they remained high. Quinolones resistance rates were high and did not change significantly over time. CONCLUSIONS The data obtained show a significant increasing trend in the incidence of E. faecium resistant to ampicillin and vancomycin.

Suscetibilidade a antifúngicos de variedades de Cryptococcus neoformans isoladas de pacientes em hospital universitário

This study identified Cryptococcus neoformans varieties isolated from 35 patients at teaching hospital of the Federal University of the Triângulo Mineiro and evaluated the susceptibility to antifungal agents among these samples using the protocol M27-A2 from the National Committee for Clinical Laboratory Standards. The gattii variety was identified in 11.4% of the cases (n = 4). The minimum inhibitory concentration (mg/ml) of Cryptococcus neoformans neoformans isolates ranged from 0.062 to 2.000 (amphotericin B), 0.250 to 8.000 (fluconazole), 0.062 to 1.000 (itraconazole) and 0.125 to 1.000 (ketoconazole). The gattii variety presented a minimum inhibitory concentration range of 0.125 to 2.000 (amphotericin B), 0.250 to 16.00 (fluconazole), 0.062 to 1.000 (itraconazole) and 0.125 to 4.000 (ketoconazole). Two isolates resistant to itraconazole and two resistant to amphotericin B (one isolate of each variety per antifungal agent) were found. These data show the importance of determining the variety and minimum inhibitory concentration of Cryptococcus neoformans isolates, in order to monitor resistance development and enable better treatment for cryptococcosis.

Avaliação da presença de Staphylococcus aureus nos leitos do Centro de Terapia Intensiva do Hospital Escola da Faculdade de Medicina do Triângulo Mineiro, em relação à posição no colchão antes e após a limpeza

By means of culture medium, it was researched the position of the colony of Staphylococcus aureus on the mattress, to evaluate the efficaciousness of the methods of cleaning and disinfection of the river bed in the Faculdade de Medicina do Triângulo Mineiros School Hospital (Uberaba). It were evaluated fifty mattresses on the period of October 22nd (2000) to January 16th (2001). The samples were collected and grown, the exhaustion technique draining, on two different nutrient bases (blood agar and mannitol salt agar) followed by catalase and coagulase tests. For the statistical analysis, were used non-parametrics tests Mann-Whitney, Kruskal-Wallis, Wilcoxon Matched Pairs Test with significance level p < 0.05 were used. Six hundred dishes of culture medium have been used. There was growing in 94 (15.6%), being 82 (87.2%) before and 12 (12.8%) after cleaning and disinfection. Concerning the position on the bed, the samples obtained from mannitol salt agar medium showed significant retention on the lower position of bed. The results alert to flaws in the procedure for cleaning and disinfection from the mattresses studied by us.

Non-biting flying insects as carriers of pathogenic bacteria in a Brazilian hospital

INTRODUCTION Insects have been described as mechanical vectors of nosocomial infections. METHODS Non-biting flying insects were collected inside a pediatric ward and neonatal-intensive care unit (ICU) of a Brazilian tertiary hospital. RESULTS Most (86.4%) of them were found to carry one or more species of bacteria on their external surfaces. The bacteria isolated were Gram-positive bacilli (68.2%) or cocci (40.9%), and Gram-negative bacilli (18.2%). CONCLUSIONS Insects collected inside a hospital were carrying pathogenic bacteria; therefore, one must consider the possibility they may act as mechanical vectors of infections, in especially for debilitated or immune-compromised patients in the hospital environments where the insects were collected.