Diferença de tempo de positividade: método útil no diagnóstico de infecção de corrente sanguínea relacionada com cateter? / Differential time to positivity: a useful tool for the diagnosis of catheter-related infections?

INTRODUÇÃO: As infecções de corrente sanguínea relacionadas com cateter (ICSRCs) apresentam impacto significativo na morbidade e na mortalidade de pacientes internados, além de elevar custos hospitalares. A utilização de equipamentos automatizados no processamento de hemoculturas gerou uma alternativa para diagnóstico de ICSRC por meio da análise da diferença de tempo de positividade (DTP) entre hemoculturas pareadas (coletadas simultaneamente) de sangue periférico e sangue de cateter. Um diagnóstico acurado e rápido dessas infecções pode otimizar as condutas clínicas e terapêuticas, poupando a retirada precoce dos cateteres. OBJETIVOS: Avaliar na rotina a DTP como ferramenta auxiliar no diagnóstico de ICSRC e determinar os principais microrganismos isolados. MÉTODOS: Foram avaliadas retrospectivamente hemoculturas coletadas no complexo do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC/FMUSP) de maio a agosto de 2008. Somente amostras que apresentaram DTP maior que 120 minutos foram consideradas possíveis ICSRCs pelo critério laboratorial. RESULTADOS: A seção processou 11.017 hemoculturas aeróbias durante o período de estudo; somente 5% foram coletadas de forma pareada. Destas, 148 (28%) foram positivas, sendo 9% com crescimento somente em sangue periférico, 41% somente em sangue de cateter e 50% em ambas as amostras com 88% de homologia de microrganismos identificados. A DTP apresentou valores acima de 120 minutos em 50% dos casos e os microrganismos mais isolados foram Staphylococcus aureus (22%), Candida spp. (18%), Klebsiella spp. (7%) e Enterobacter spp. (7%). CONCLUSÃO: A determinação da DTP como ferramenta auxiliar no diagnóstico de ICSRC é viável e fácil de ser executada em laboratórios de rotina com automação, porém o processo de coleta das amostras pareadas deve ser rigidamente padronizado.

INTRODUCTION: Not only do catheter related bloodstream infections (CRBSIs) have considerable impact on morbidity and mortality in hospitalized patients, but they also raise hospital costs. The use of automated equipment in blood culture processing has allowed an alternative diagnosis of CRBSI by analyzing the differential time to positivity (DTP) of paired blood cultures (collected simultaneously) of peripheral blood and catheter blood. A rapid and accurate diagnosis of these infections may optimize clinical and therapeutic management, which prevents early catheter removal. OBJECTIVES: To assess DTP as an auxiliary tool for the diagnosis of CRBSI as well as to determine the main isolated microorganisms. METHODS: We evaluated blood cultures that had previously been collected in the complex Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC/FMUSP) from May to August 2008. According to the laboratory criteria, only DTP higher than 120 minutes was regarded as possible CRBSI. RESULTS: During the investigation period 11,017 aerobic blood cultures were processed, from which only 5% were paired samples. One hundred forty-eight (28%) samples were positive, from which 9% showed growth in peripheral blood, 41% only in catheter blood and 50% in both blood samples with 88% homology of identified microorganisms. DTP higher than 120 minutes occurred in 50% of the cases. The most common isolated microorganisms were: Staphylococcus aureus (22%), Candida spp. (18%), Klebsiella spp (7%). and Enterobacter spp (7%). CONCLUSION: The determination of the DTP as an auxiliary tool for the diagnosis of CRBSI is feasible and easily performed in clinical laboratories with automation, although the process of paired sample collection must be rigidly standardized.

Candidemia epidemiology and susceptibility profile in the largest Brazilian teaching hospital complex

INTRODUCTION: Although the spectrum of fungi causing bloodstream fungal infections continues to expand, Candida spp. remains responsible for the majority of these cases. OBJECTIVE: The purpose of this study was to characterize the candidemia epidemiology, species distribution and antifungal susceptibility patterns at a Brazilian tertiary teaching public hospital with 2,500 beds. METHODS: Records from the microbiology laboratory were used to identify patients with positive blood cultures during 2006. The in vitro activity of amphotericin B, caspofungin, itraconazole, fluconazole, voricanozole, and posaconazole were determined using the Etest method. RESULTS: One hundred and thirty-six cases of candidemia were identified and 100 strains were available for antifungal susceptibility testing. The overall incidence of candidemia was 1.87 cases/1.000 admissions and 0.27 cases/1.000 patient-days. Among the patients, 58.1 percent were male, and the median age was 40 years old. C. albicans was the most common species (52.2 percent), followed by C. parapsilosis (22.1 percent), C. tropicalis (14.8 percent), and C. glabrata (6.6 percent). All strains were susceptible to amphotericin B with a MIC90 of 0.5 µg/mL. Overall susceptibility for voriconozole, fluconazole, and caspofungin was > 97 percent with a MIC90 of 0.064, 4.0 and 1.0 µg/mL, respectively. For itraconazole the susceptibility rate was 81 percent with a MIC90 of 0.5 µg/mL. Posaconazole also demonstrated good in vitro activity with a MIC90 of 0.25 µg/mL. CONCLUSION: This is the first antifungal susceptibility report in our institution.

Candidemia epidemiology and susceptibility profile in the largest Brazilian teaching hospital complex.

INTRODUCTION: Although the spectrum of fungi causing bloodstream fungal infections continues to expand, Candida spp. remains responsible for the majority of these cases. OBJECTIVE: The purpose of this study was to characterize the candidemia epidemiology, species distribution and antifungal susceptibility patterns at a Brazilian tertiary teaching public hospital with 2,500 beds. METHODS: Records from the microbiology laboratory were used to identify patients with positive blood cultures during 2006. The in vitro activity of amphotericin B, caspofungin, itraconazole, fluconazole, voricanozole, and posaconazole were determined using the Etest method. RESULTS: One hundred and thirty-six cases of candidemia were identified and 100 strains were available for antifungal susceptibility testing. The overall incidence of candidemia was 1.87 cases/1.000 admissions and 0.27 cases/1.000 patient-days. Among the patients, 58.1% were male, and the median age was 40 years old. C. albicans was the most common species (52.2%), followed by C. parapsilosis (22.1%), C. tropicalis (14.8%), and C. glabrata (6.6%). All strains were susceptible to amphotericin B with a MIC90 of 0.5 µg/mL. Overall susceptibility for voriconozole, fluconazole, and caspofungin was > 97% with a MIC90 of 0.064, 4.0 and 1.0 µg/mL, respectively. For itraconazole the susceptibility rate was 81% with a MIC90 of 0.5 µg/mL. Posaconazole also demonstrated good in vitro activity with a MIC90 of 0.25 µg/mL. CONCLUSION: This is the first antifungal susceptibility report in our institution.

Listeria monocytogenes peritonitis in cirrhotic patients: first description in Brazil / Peritonite bacteriana espontânea causada por Listeria monocytogenes em pacientes com cirrose: primeiro relato de caso no Brasil

Two cases of spontaneous bacterial peritonitis (SBP) caused by Listeria monocytogenes in cirrhotic patients are reported. In one of the cases, the microorganism was isolated from pleural effusion and ascites. SBP is a serious and common complication of patients with ascites caused by hepatic cirrhosis and the culture of the ascitic fluid is an important tool for the diagnosis and for the more appropriate treatment. Although a third generation cephalosporin has usually been employed for empiric treatment of SBP, it does not provide adequate coverage against Listeria spp. In such cases the use of ampicillin (with or without sulbactam) or sulfamethoxazole-trimethoprim is recommended. The last one is used for secondary prophylaxis, instead of norfloxacin. To summarize, Listeria monocytogenes infection is a rare cause of SBP, whose treatment should be specific for the bacteria.

Foram relatados dois casos de peritonite bacteriana espontânea (PBE) por Listeria monocytogenes em pacientes com cirrose. Em um dos casos isolamos também o agente no líquido pleural. A PBE é uma complicação comum e grave de pacientes com ascite por cirrose e a cultura do líquido ascítico é de grande importância para o diagnóstico e para o tratamento mais adequado. Embora uma cefalosporina de terceira geração seja geralmente utilizada para o tratamento empírico da PBE, ela não oferece cobertura adequada contra a Listeria spp. Nesses casos, recomenda-se o uso de ampicilina (com ou sem sulbactam) ou sulfametoxazol-trimetoprim. Para a profilaxia secundária indica-se o uso deste último, ao invés da norfloxacina. Em resumo, a infecção por Listeria monocytogenes é uma causa rara de PBE e o tratamento específico deve ser administrado.

Rhodotorula spp. isoladas de hemocultura no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo: características clínicas e microbiológicas / Rhodotorula spp. isolated from blood cultures in Hospital das Clínicas School of Medicine University of São Paulo: clinical and microbiological aspects

Foi realizado um estudo para verificar a ocorrência de leveduras do gênero Rhodotorula, em hemocultura por um período de 8 anos. Os pacientes identificados foram descritos clinicamente segundo variáveis de interesse incluindo dados sobre terapêutica e desfecho. Determinou-se também as concentrações inibitórias mínimas de 20 cepas frente a diferentes antifúngicos de acordo com NCCLS e EUCAST. Realizou-se tipagem molecular através da cariotipagem eletroforética em campo pulsátil.

A study was conducted to verify the frequency of occurrence of Rhodotorula spp. from blood cultures over an 8-year period, clinically and microbiologically characterizing patients affected, including data regarding antifungal treatment and outcome. The minimal inhibitory concentrations of antifungal agents were determined against 20 isolates. Molecular typing of the strains were performed using pulsed field gel electrophoresis method.