Clinical and microbiological characteristics of OXA-23- and OXA-143-producing Acinetobacter baumannii in ICU patients at a teaching hospital, Brazil

ABSTRACT Background: Carbapenem-resistant Acinetobacter baumannii (CRAb) is an important cause of nosocomial infections especially in intensive care units. This study aimed to assess clinical aspects and the genetic background of CRAb among ICU patients at a Brazilian teaching hospital. Methods: 56 critically ill patients colonized or infected by CRAb, during ICU stay, were prospectively assessed. Based on imipenem MIC ≥ 4 µg/mL, 28 CRAB strains were screened for the presence of genes encoding metallo-β-lactamases and OXA-type β-lactamases. The blaOXA-type genes were characterized by PCR using primers targeting ISAba-1 or -3. Genetic diversity of blaOXA-positive strains was determined by ERIC-PCR analysis. Results: Patient's mean age (±SD) was 61 (±15.1), and 58.9% were male. Eighty-percent of the patients presented risk factors for CRAb colonization, mainly invasive devices (87.5%) and previous antibiotic therapy (77.6%). Thirty-three patients died during hospital stay (59.0%). Resistance to carbapenems was associated with a high prevalence of blaOXA-23 (51.2%) and/or blaOXA-143 (18.6%) genes. ERIC-PCR genotyping identified 10 clusters among OXA-producing CRAb. Three CRAb strains exhibited additional resistance to polymyxin B (MIC ≥ 4 µg/mL), whereas 10 CRAb strains showed tigecycline MICs > 2 µg/mL. Conclusions: In this study, clonally unrelated OXA-123- and OXA-143-producing A. baumannii strains in ICU patients were strongly correlated to colonization with infected patients being associated with a poor outcome.

Risk factors for laboratory-confirmed bloodstream infection in neonates undergoing surgical procedures

BACKGROUND: Healthcare Associated Infections constitute an important problem in Neonatal Units and invasive devices are frequently involved. However, studies on risk factors of newborns who undergo surgical procedures are scarce. OBJECTIVE: To identify risk factors for laboratory-confirmed bloodstream infection in neonates undergoing surgical procedures. METHODS: This case-control study was conducted from January 2008 to May 2011, in a referral center. Cases were of 21 newborns who underwent surgery and presented the first episode of laboratory-confirmed bloodstream infection. Control was 42 newborns who underwent surgical procedures without notification of laboratory-confirmed bloodstream infection in the study period. Information was obtained from the database of the Hospital Infection Control Committee Notification of infections and related clinical data of patients that routinely collected by trained professionals and follow the recommendations of Agência Nacional de Vigilância Sanitária and analyzed with Statistical Package for Social Sciences. RESULTS: During the study period, 1141 patients were admitted to Neonatal Unit and 582 Healthcare Associated Infections were reported (incidence-density of 25.75 Healthcare Associated Infections/patient-days). In the comparative analysis, a higher proportion of laboratory-confirmed bloodstream infection was observed in preterm infants undergoing surgery (p = 0.03) and use of non-invasive ventilation was a protective factor (p = 0.048). Statistically significant difference was also observed for mechanical ventilation duration (p = 0.004), duration of non-invasive ventilation (p = 0.04), and parenteral nutrition duration (p = 0.003). In multivariate analysis duration of parenteral nutrition remained significantly associated with laboratory-confirmed bloodstream infection (p = 0.041). CONCLUSIONS: Shortening time on parenteral nutrition whenever possible and preference ...

Fatores de risco e letalidade de infecção da corrente sanguínea laboratorialmente confirmada, causada por patógenos não contaminantes da pele em recém-nascidos / Risk factors and lethality of laboratory-confirmed bloodstream infection caused by non-skin contaminant pathogens in neonates

OBJECTIVE: To evaluate risk factors and lethality of late onset laboratory-confirmed bloodstream infection (ICSLC) in a Brazilian neonatal unit for progressive care (NUPC). Methods: This was a case-control study, performed from 2008 to 2012. Cases were defined as all newborns with late onset ICSLC, excluding patients with isolated common skin contaminants. Controls were newborns who showed no evidence of late onset ICSLC, matched by weight and time of permanence in the NUPC. Variables were obtained in the Hospital Infection Control Committee (HICC) database. Analysis was performed using the Statistical Package for the Social Sciences (SPSS). The chi-squared test was used, and statistical significance was defined as p < 0.05, followed by multivariate analysis. RESULTS: 50 patients with late onset ICSLC were matched with 100 patients without late onset ICSLC. In the group of patients with late onset ICSLC, a a significant higher proportion of patients who underwent surgical procedures (p = 0.001) and who used central venous catheter (CVC) (p = 0.012) and mechanical ventilation (p = 0.001) was identified. In multivariate analysis, previous surgery and the use of CVC remained significantly associated with infection (p = 0.006 and p = 0.047; OR: 4.47 and 8.99, respectively). Enterobacteriacea was identified in 14 cases, with three (21.4%) deaths, and Staphylococcus aureus was identified in 20 cases, with three (15%) deaths. CONCLUSIONS: Surgical procedures and CVC usage were significant risk factors for ICSLC. Therefore, prevention practices for safe surgery and CVC insertion and manipulation are essential to reduce these infections, in addition to training and continuing education to surgical and assistance teams.

OBJETIVO: Avaliar os fatores de risco e a letalidade da infecção da corrente sanguínea laboratorialmente confirmada (ICSLC) de início tardio em uma Unidade Neonatal de Cuidados Progressivos (UNCP) brasileira. MÉTODOS: Trata-se de um estudo caso-controle realizado de 2008 a 2012. Os casos foram definidos como todos os recém-nascidos com ICSLC de início tardio, excluindo pacientes isolados com contaminantes da pele comuns. Os controles foram recém-nascidos que não mostraram qualquer evidência de ICSLC de início tardio, sendo separados por peso e tempo de permanência na UNCP. As variáveis foram obtidas na base de dados da Comissão de Controle de Infecção Hospitalar (CCIH). A análise foi realizada utilizando o Pacote Estatístico para Ciências Sociais. O teste χ² foi utilizado e a relevância estatística foi definida como p < 0,05, seguida pela análise multivariada. RESULTADOS: No estudo, 50 pacientes com ICSLC de início tardio foram combinados com 100 pacientes sem ICSLC de início tardio. No grupo de pacientes com ICSLC de início tardio, identificamos uma proporção significativamente maior de pacientes que foram submetidos a procedimentos cirúrgicos (p = 0,001) e que usaram cateter venoso central (CVC) (p = 0,012) e ventilação mecânica (p = 0,001). Na análise multivariada, cirurgia prévia e uso de CVC permaneceram significativamente associados à infecção (p = 0,006 e p = 0,047; OU: 4,47 e 8,99, respectivamente). A Enterobacteriacea foi identificada em 14 casos, com três (21,4%) óbitos, e Staphylococcus aureus foi identificado em 20 casos, com três (15%) óbitos. CONCLUSÕES: Procedimentos cirúrgicos e uso de CVC constituíram fatores de risco significativos para ICSLC. Portanto, práticas de prevenção para cirurgia segura, inserção e manipulação de CVC são essenciais para reduzir essas infecções, além de treinamento e educação contínua às equipes cirúrgicas e de assistência.

Conduta em infecções relacionadas a cateter venoso central em um hospital de referência / Care conduct for central venous catheter-related infectionsat an excellence hospital

Objetivos: avaliar a adesão às recomendações para diagnóstico de sepse relacionada a cateter (SRC), verificando a realização simultânea cultura de ponta de cateter (CPC) e hemocultura de sangue periférico (HP), em um hospital de referência. Métodos: trata-se de estudo transversal, realizado no Hospital das Cínicas da Universidade Federal de Minas Gerais, no período de janeiro de 2007 a outubro de 2009. Os dados foram coletados por profissionais especializados da Comissão de Controle de Infecção Hospitalar. Os critérios de base basearam-se nos critérios de notificação do National Healthcare Safety Network e diretrizes da Infectious Diseases Society of America (IDSA). Os dados foram digitados e analisados pelo Statistical Package for the Social Sciences (SPSS) versão 14.0. Resultados: de 683 CPC com crescimento de microrganismos, apenas 220 (32,2%) apresentaram isolamento de microrganismo em HP concomitante. Desses 220 casos, 74,1% apresentaram crescimento do mesmo microrganismo, com mesmo perfil fenotípico, em ambas as amostras. Nos casos de HP com resultado negativo e casos em que a HP não foi realizada, antimicrobianos foram prescritos em 25,7 e 31,5% dos casos, respectivamente, embora não tenha havido critérios para definição de SRC. Conclusão: apenas da recomendação de realização de CPC pareada com HP, este estudo reflete a prática de realização de CPC isolada e pode estar relacionada ao uso inapropriado de antimicrobianos, aumentando custos da assistência e favorecendo a seleção de resistência bacteriana. O diagnóstico e tratamento da SRC devem ser melhorados e os profissionais devem ser conscientizados das práticas adequadas de manejo de cateter venoso central...

Objectives: This study aims to assess compliance with recommendations for the diagnosis of catheter-related bloodstream infection (CRBSI) at an excellence hospital by verifying simultaneous performance of catheter tip culture (CTC) and peripheral blood culture (PBC). Methods: This is a cross-sectional study conducted at UFMG University Hospital from January 2007 through October 2009. Data were collected by specialized professionals of the Hospital Infection Control Committee. The notification criteria followed those prescribed by the National Healthcare Safety Network and the Infectious Diseases Society of America (IDSA). Database and statistical analysis was performed using SPSS (Statistical Package for the Social Sciences) version 14.0. Results: Concurrent peripheral blood culture was performed for only 220 (32.2%) of the 683 CTC samples presenting microorganism growth. This points to low compliance with the existing guidelines. Out of the 220 positive CTC paired with PBC results, 74.1% presented the same microorganism, with the same phenotypic profile in both samples. As for negative PBC results and no blood culture testing, antibiotics were prescribed in 25.7 and 31.5% of the cases respectively, despite the inexistence of criteria to determine CRBSI. Conclusions: Despite recommendations for pairing CTC and PBC results, this study points to the common practice of performing isolated CTC tests. This may lead to inappropriate use of antimicrobials, increasing health care costs and selection of resistant bacteria. CRBSI diagnosis and treatment should be improved, and professionals should be aware of adequate practices and management of central venous catheter...

Microbiota indígena de seres humanos / Indigenous microbiota of human beings

As superfícies do corpo humano são colonizadas por uma comunidade de organismos, principalmente bactérias, que constitui a microbiota indígena. A composição desta microbiota se altera ao longo da vida e é influenciada por diversos fatores, tais como dieta e status imunológico do hospedeiro. A microbiota pode agir de maneira benéfica ou, em algumas situações, pode ser prejudicial para o indivíduo. Podem ser distinguidas a microbiota residente, constituída por organismos específicos, encontrados, freqüentemente, em determinadas áreas e a microbiota transitória, que consiste de microrganismos provenientes do ambiente, que habitam a pele e as superfícies mucosas por horas ou poucas semanas. Trato gastrointestinal, vagina, cavidade oral e pele possuem a microbiota mais rica e diversificada do corpo humano. O conhecimento da constituição da microbiota indígena é extremamente relevante para os médicos, principalmente para orientar a interpretação de resultados de exames microbiológicos e a escolha da terapia antimicrobiana empírica mais adequada. Deve-se salientar que a microbiota geralmente é benéfica. Por esse motivo, é fundamental que se tenha consciência dos riscos do rompimento da homeostasia entre microbiota e hospedeiro.

Body surfaces are colonized by a community of organisms that are recognized as indigenous microbiota, that is mainly constituted by bacteria. Its constitution changes with time and is influenced by several conditions such as diet and the immune status of the individual, among others. There are now evidences that the microbiota could be beneficial or, in some instances, dangerous to human health. It could be classified as resident, composed by fixed organisms, frequently found in certain areas, or as transitory, consisting of organisms from the environment that inhabits skin and mucosa for hours to few weeks. The gastrointestinal tract, vagina, oral cavity and skin show the richest and most diverse microbiota of the human body. The knowledge of the constitution of the indigenous microbiota is extremely important for clinicians, mainly because it can help them to interpret results of microbiological tests and to choose appropriate empirical therapy. It should be pointed out that microbiota is, in general, harmless and beneficial; for these reason, physicians must keep in mind that the disruption of the homeostasis between microbiota and host should be avoided.