Rosiéli Martini

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.

INVESTIGATION OF BIOFILM FORMATION IN COAGULASE-NEGATIVE STAPHYLOCOCCI ISOLATED FROM PLATELET CONCENTRATE BAGS

Platelet Concentrates (PCs) are the blood components with the highest rate of bacterial contamination, and coagulase-negative staphylococci (CoNS) are the most frequently isolated contaminants. This study investigated the biofilm formation of 16 contaminated units out of 691 PCs tested by phenotypic and genotypic methods. Adhesion in Borosilicate Tube (ABT) and Congo Red Agar (CRA) tests were used to assess the presence of biofilm. The presence of icaADC genes was assessed by means of the Polymerase Chain Reaction (PCR) technique. With Vitek(r)2, Staphylococcus haemolyticus was considered the most prevalent CoNS (31.25%). The CRA characterized 43.8% as probable biofilm producers, and for the ABT test, 37.5%. The icaADC genes were identified in seven samples by the PCR. The ABT technique showed 85.7% sensitivity and 100% specificity when compared to the reference method (PCR), and presented strong agreement (k = 0.8). This study shows that species identified as PCs contaminants are considered inhabitants of the normal skin flora and they might become important pathogens. The results also lead to the recommendation of ABT use in laboratory routine for detecting biofilm in CoNS contaminants of PCs.

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.

Staphylococcal scalded skin syndrome in a premature newborn caused by methicillin-resistant Staphylococcus aureus: case report

CONTEXT Staphylococcal scalded skin syndrome is an exfoliative skin disease. Reports of this syndrome in newborns caused by methicillin-resistant Staphylococcus aureus are rare but, when present, rapid diagnosis and treatment is required in order to decrease morbidity and mortality. CASE REPORT A premature newly born girl weighing 1,520 g, born with a gestational age of 29 weeks and 4 days, developed staphylococcal scalded skin syndrome on the fifth day of life. Cultures on blood samples collected on the first and fourth days were negative, but Pseudomonas aeruginosa and Enterococcus sp. (vancomycin-sensitive) developed in blood cultures performed on the day of death (seventh day), and Pseudomonas aeruginosa and Serratia marcescens were identified in cultures on nasopharyngeal, buttock and abdominal secretions. In addition to these two Gram-negative bacilli, methicillin-resistant Staphylococcus aureus was isolated in a culture on the umbilical stump (seventh day). The diagnosis of staphylococcal scalded skin syndrome was based on clinical criteria.

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.

Contaminação bacteriana em concentrados plaquetários: identificação, perfil de sensibilidade aos antimicrobianos e sepse associada à transfusão

INTRODUCTION Bacterial sepsis associated with the transfusion of platelet concentrates (PCs) results in serious clinical implications for patients. Given these implications, certain procedures have been integrated into the preparation and quality control of blood components to reduce the risk of bacterial contamination. This article describes the prevalence of bacterial contamination on transfused PCs, the bacterial spectrum detected and their antimicrobial susceptibility profile and transfusion reactions in receptors. METHODS A total of 292 PCs (278 random and 14 per apheresis) from the Blood Center of the State of Rio Grande do Sul (HEMORGS), located in the city of Santa Maria, were tested. Quantities of 100 μL and 200 μL were collected from platelet bag tubing and seeded using two methodologies. RESULTS Using the qualitative methodology, bacteria were isolated in five units (1.7%; 5/292), while only one was isolated using the quantitative methodology. Staphylococcus epidermidis was the microorganism identified in all samples. Two patients died of transfusion-related sepsis. CONCLUSIONS Bacterial contamination due to PC transfusion is considered a major public health problem due to its association with high rates of morbidity and mortality. In this study only gram-positive microorganisms were isolated and none of the samples obtained by apheresis presented contamination.

Necrotizing fasciitis caused by Streptococcus agalactiae in a diabetic patient - case report

OBJETIVOS: Descrever um caso de fasciite necrosante e choque septico ocasionado por Streptococcus agalactiae, que acometeu uma paciente com diabetes mellitus. Esta analise foi realizada atraves dos dados do prontuario e resultados de exames laboratoriais da paciente, que estava internada no Hospital Universitario de Santa Maria, em Santa Maria, Rio Grande do Sul. DESCRICAO DO CASO: Paciente do genero feminino, 73 anos, diagnosticada com diabetes mellitus e cirrose micronodular, foi internada com suspeita de septicemia, simultânea a uma infeccao no membro inferior esquerdo, cuja hipotese diagnostica inicial foi de celulite. Pelas caracteristicas do quadro clinico, foi feito o diagnostico de fasciite necrosante. Hemoculturas de dois sitios diferentes positivaram para S. agalactiae. A paciente foi a obito por choque septico. CONCLUSOES: O relato deste caso enfatiza a gravidade da fasciite necrosante, que pode ocorrer principalmente em pacientes portadores de fatores predisponentes como diabetes mellitus e cirrose.Objetivos: Descrever um caso de fasciite necrosante e choque septico ocasionado por Streptococcus agalactiae, que acometeu uma paciente com diabetes mellitus. Esta analise foi realizada atraves dos dados do prontuario e resultados de exames laboratoriais da paciente, que estava internada no Hospital Universitario de Santa Maria, em Santa Maria, Rio Grande do Sul.Descricao do caso: Paciente do genero feminino, 73 anos, diagnosticada com diabetes mellitus e cirrose micronodular, foi internada com suspeita de septicemia, simultânea a uma infeccao no membro inferior esquerdo, cuja hipotese diagnostica inicial foi de celulite. Pelas caracteristicas do quadro clinico, foi feito o diagnostico de fasciite necrosante. Hemoculturas de dois sitios diferentes positivaram para S. agalactiae. A paciente foi a obito por choque septico.Conclusoes: O relato deste caso enfatiza a gravidade da fasciite necrosante, que pode ocorrer principalmente em pacientes portadores de fatores predisponentes como diabetes mellitus e cirrose. Aims: To report an unusual case of necrotizing fasciitis and septic shock caused by Streptococcus agalactiae, which affected a patient with diabetes mellitus. This analysis was performed using data from medical records and laboratory tests results, who was admitted to the University Hospital of Santa Maria, in Santa Maria, Rio Grande do Sul, Brazil.Case description: Female patient, 73 years old, diagnosed with diabetes mellitus and micronodular cirrhosis, was admitted with suspected septicemia simultaneous with an infection in the left lower limb, which initial diagnostic hypothesis was cellulitis. Based on characteristics of the clinical picture, the diagnosis of necrotizing fasciitis was done. Blood cultures from two different sites were positive for S. agalactiae. The patient died with septic shock.Conclusions: This case report emphasizes the severity of necrotizing fasciitis, which may occur especially in patients with predisposing factors such as diabetes mellitus and cirrhosis.

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.