Maísa Kraulich Tizotti

Bacteriological analysis of platelets and cases of septic reactions associated with transfusion of contaminated samples.

INTRODUCTION For years, platelet transfusion therapy has been playing an important role in controlling patients with hematological and oncological diseases. However, platelet transfusion represents a serious risk for bacterial sepsis. This study aimed to verify the bacterial contamination index in platelet concentrates (PCs) obtained from the Blood Center of the State of Rio Grande do Sul (HEMORGS). METHODS All 612 samples of PCs from HEMORGS were analyzed in August 2009 and January 2010. We used a qualitative methodology which was modified manually in order to detect bacterial contamination. The patients who received the platelet units with confirmed positive cultures had their medical records analyzed. After the prospective study, a retrospective analysis of the samples of PCs checked by the bacteriological control from HEMORGS since its foundation (2008) until 2010 was made. RESULTS Four hundred and eighty samples (10 monthly samples of plateletpheresis and 10 of whole blood-derived platelets) were analyzed in order to compare the contamination index for both studies. Of 1092 samples, 15 were found to be contaminated (6 of retrospective analysis and 9 of prospective). In prospective study, isolated microorganisms were nine Staphylococcus epidermidis, but in retrospective two Staphylococcus sp., two glucose non-fermenting gram negative bacilli, one Streptococcus sp. and one Proteus mirabilis. We report 3 feasible cases of bacterial sepsis associated with the transfusion of CPs analyzed by prospective study. CONCLUSION Bacterial sepsis associated with platelet transfusion is today the most frequent infectious complication of transfusion medicine. Although complex, it is important to recognize transfusion sepsis in patients to reduce morbidity and mortality.

Oxacillin-resistant coagulase-negative Staphylococci bacteremia at a teaching hospital in Santa Maria, State of Rio Grande do Sul, Brazil

INTRODUCTION This study aimed to characterize the prevalence and susceptibility profile to oxacillin-resistant Coagulase-negative Staphylococci strains isolated from blood cultures in a teaching hospital, located in Santa Maria, RS. In addition, different methodologies for phenotypic characterization of mecA-mediated oxacillin resistance were compared with genotypic reference testing. METHODS After identification (MicroScan - Siemens), the isolates were tested for antimicrobial sensitivity using disk diffusion and automation (MicroScan - Siemens). The presence of mecA gene was identified by the polymerase chain reaction molecular technique. RESULTS The most common species was Staphylococcus epidermidis (n=40, 67%). The mecA gene was detected in 54 (90%) strains, while analysis of the sensitivity profiles revealed a high rate of resistance to multiple classes of antimicrobial drugs. However, all isolates were uniformly sensitive to vancomycin and tigecycline. The cefoxitin disk was the phenotypic method that best correlated with the gold standard. CONCLUSIONS Analysis of the clinical significance of CoNS isolated from hemocultures and the precise detection of oxacillin resistance represent decisive factors for the correct choice of antibiotic therapy. Although vancomycin constitutes the normal treatment in most Brazilian hospitals, reduction in its use is recommended.

PREVALÊNCIA E PERFIL DE SENSIBILIDADE DE Staphylococcus aureus ISOLADOS EM UM HOSPITAL ESCOLA NA CIDADE DE SANTA MARIA, BRASIL

Objetivou-se caracterizar a prevalencia e o perfil de suscetibilidade de Staphylococcus aureus isolados no Hospital Universitario de Santa Maria (HUSM), atraves de levantamento de dados junto ao Laboratorio de Analises Clinicas, durante o periodo de abril a junho de 2009. Foram solicitadas 3270 culturas, sendo que 1123 (34%) resultaram positivas. A prevalencia de S. aureus em relacao as culturas positivas foi de 89 (7,93%). Verificou-se que 33% das cepas foram resistentes a oxacilina e que 34,45% apresentaram resistencia relacionada ao gene erm. Elevada sensibilidade ao sulfametoxazol-trimetoprima (72/80%) foi evidenciada pela automacao e nenhuma cepa mostrou-se resistente a vancomicina. Portanto, a prevalencia de S. aureus no HUSM e a resistencia a oxacilina foram inferiores ao observado em outros hospitais terciarios brasileiros. The objective ofthis study was to characterize the prevalence and susceptibility prof ile ofStaphylococcus aureus isolates at University Hospital ofSantaMaria, through data collection at the Laboratory ofClinicalAnalysis, duringApril to June 2009. Were requested 3270 cultures and 1123 (34%) were positive. The prevalence of S. aureus in relation to positive cultures was 89 (7,93%). It was f ound that these strains, 33% were resistant to oxacillin and 34.45% showed resistance related erm gene. High sensitivity to trimethoprim-sulf amethoxazole (72/80%) was detected f or the automation and no strain showed resistance to vancomycin. Theref ore, the prevalence of S. aureus and oxacillin resistance at HUSM were lower than observed in other tertiary hospitals in Brazil. Descritors: Prevalence; Staphylococcus aureus; Bacterial inf ection, Oxacillin.

CARACTERIZAÇÃO DE CULTURAS DE URINA REALIZADAS NO LABORATÓRIO DE ANÁLISES CLÍNICAS DO HOSPITAL UNIVERSITÁRIO DE SANTA MARIA – SANTA MARIA, RS, NO PERÍODO DE 2007 À 2010

A infeccao do trato urinario (ITU) e considerada uma das doencas mais comuns de origem bacteriana. Objetivou-se determinar a prevalencia de ITU em pacientes atendidos no Hospital Universitario de Santa Maria, o agente mais isolado, a incidencia entre os sexos e a faixa etaria mais acometida. Realizou-se um estudo retrospectivo das uroculturas solicitadas no HUSM, no periodo de 2007 a 2010, as quais foram cultivadas no setor de Microbiologia do Laboratorio de Analises Clinicas. Dos 34.898 exames solicitados, 6.190 (17,74%) foram positivos. O sexo feminino apresentou o maior percentual de positividade (72,94%) e a faixa etaria feminina mais acometida foi entre 14 a 40 anos (37,6%) e a masculina entre 41 a 64 anos (10,6%). O microrganismo prevalente foi a Escherichia coli com 31,9%. A partir deste estudo pode-se verificar que os bacilos gram-negativos (BGN) foram os patogenos prevalentes, alem disso, ocorreu um significativo numero de isolados de Candida sp.

Evaluation of bacterial growth inhibition by mercaptopropionic acid in metallo-β-lactamase detection on multidrug-resistant Acinetobacter baumannii

INTRODUCTION Metallo-β-lactamase (MBL) has been reported all over the world. METHODS The inhibitory effect of mercaptopropionic acid (MPA) on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC) for multidrug-resistant Acinetobacter baumanni strains. RESULTS MPA significantly inhibited growth of the strains. CONCLUSIONS The use of MPA can affect the results in phenotypic methods of MBL detection.