Microbiological characteristics of bloodstream infections in a reference hospital in northeastern Brazil

Abstract Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Resumo A cultura sanguínea de rotina é usada para a detecção de infecções na corrente sanguínea por bactérias aeróbias e anaeróbias e por leveduras patogênicas comuns. Estudo retrospectivo realizado em hospital público de Maceió-AL, por meio da coleta de dados de todos os prontuários com culturas sanguíneas positivas. Das 2.107 culturas sanguíneas realizadas, 17% foram positivas com Staphylococcus coagulase negativo (51,14%), seguido por Staphylococcus aureus (11,21%) e Klebsiella pneumoniae (6,32%). As bactérias Gram-positiva predominaram entre as culturas de sangue positivas, destacando-se o grupo das Staphylococcus coagulase-negativo. Enquanto as bactérias Gram-negativas apresentaram um número maior de espécies entre as culturas de sangue positivas.

Microbiological characteristics of bloodstream infections in a reference hospital in northeastern Brazil / Características microbiológicas de infecções da corrente sanguínea em hospital de referência no nordeste do Brasil

Abstract Routine blood culture is used for the detection of bloodstream infections by aerobic and anaerobic bacteria and by common pathogenic yeasts. A retrospective study was conducted in a public hospital in Maceió-AL, by collecting data of all medical records with positive blood cultures. Out of the 2,107 blood cultures performed, 17% were positive with Staphylococcus coagulase negative (51.14%), followed by Staphylococcus aureus (11.21%) and Klebsiella pneumoniae (6.32%). Gram-positive bacteria predominated among positive blood cultures, highlighting the group of Staphylococcus coagulase-negative. While Gram-negative bacteria had a higher number of species among positive blood cultures.

Resumo A cultura sanguínea de rotina é usada para a detecção de infecções na corrente sanguínea por bactérias aeróbias e anaeróbias e por leveduras patogênicas comuns. Estudo retrospectivo realizado em hospital público de Maceió-AL, por meio da coleta de dados de todos os prontuários com culturas sanguíneas positivas. Das 2.107 culturas sanguíneas realizadas, 17% foram positivas com Staphylococcus coagulase negativo (51,14%), seguido por Staphylococcus aureus (11,21%) e Klebsiella pneumoniae (6,32%). As bactérias Gram-positiva predominaram entre as culturas de sangue positivas, destacando-se o grupo das Staphylococcus coagulase-negativo. Enquanto as bactérias Gram-negativas apresentaram um número maior de espécies entre as culturas de sangue positivas.

Genotyping of methicillin-resistant Staphylococcus aureus isolates obtained in the Northeast region of Brazil

Methicillin-resistant Staphylococcus aureus (MRSA) is a major agent of hospital infections worldwide. In Brazil, a multiresistant MRSA lineage (ST239-SCCmecIIIA), the so-called Brazilian epidemic clone (BEC), has predominated in all regions. However, an increase in nosocomial infections caused by non-multiresistant MRSA clones has recently been observed. In the present study, 45 clinical isolates of MRSA obtained from a university hospital located in Natal city, Brazil, were identified by standard laboratory methods and molecularly characterized using staphylococcal chromosome cassette mec (SCCmec) typing and pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was carried out using CLSI methods. The MRSA isolates studied displayed a total of 8 different pulsed-field gel electrophoresis patterns (types A to H) with predominance (73 percent) of pattern A (BEC-related). However, MRSA harboring SCCmec type IV were also identified, 3 (7 percent) of which were genetically related to the pediatric clone - USA800 (ST5-SCCmecIV). In addition, we found a considerable genetic diversity within BEC isolates. MRSA displaying SCCmecIV are frequently susceptible to the majority of non-β-lactam antibiotics. However, emergence of multiresistant variants of USA800 was detected.

Staphylococcus aureus e estafilococos coagulase negativosresistentes à vancomicina em um Hospital Universitário Brasileiro / Vancomycin-resistant Staphylococcus aureus and coagulase-negative staphylococci in a Brazilian University Hospital

Infecções hospitalares por Methicillin-Resistant S. aureus (MRSA) e Methicillin-Resistant Coagulase-Negative Staphylococci (MRCoNS) estão entre as mais frequentes mundialmente, justificando um aumento significativo no uso de vancomicina. Com o objetivo de avaliar a presença de estafilococos resistentes aos glicopeptídeos em pacientes em uso terapêutico desse antimicrobiano, internados no Hospital de Clínicas da Universidade Federal de Uberlândia, Uberlândia MG, foi realizado um estudo longitudinal prospectivo incluindo 41 pacientes, 21 adultos e 20 crianças, entre dezembro de 2000 e março de 2002. O monitoramento microbiológico foi realizado por meio de swabs coletados a partir da cavidade bucal e reto e cultivo primário em Ágar Manitol Salgado acrescido de 6 mg/mL de oxacilina. Amostras selecionadas foram testadas quanto à sensibilidade aos glicopeptídeos pelas técnicas de gel difusão e diluição em ágar e a análise de heterorresistência, pela semeadura utilizando inóculo correspondente à escala 0,5 de McFarland (108 UFC/mL) e análise do perfil populacional. Um único paciente, nefropata em programa de hemodiálise apresentou-se colonizado com uma amostra do fenótipo Vancomycin-Intermediate S. aureus (VISA) (CIM = 8 miug/mL) e em doze, foram isoladas amostras de estafilococos heterorresistentes, correspondendo oito hVISA e quatro hVICoNS. O estudo do perfil populacional, confirmou a presença de subpopulações de células resistentes, sendo seis hVISA e duas hVICoNS. A presença de amostras heterorresistentes à vancomicina pode representar um risco potencial no futuro.

Methicillin-resistant Staphylococcus aureus (MRSA) and Methicillin-resistant Coagulase-negative Staphylococci (MRCoNS) are among the most frequent hospital infections around the world, and are associated with a significant rise in the use of vancomycin. In order to assess the presence of staphylococci resistant to glycopeptides in patients taking this antibiotic in Uberlândia Federal University Hospital, Uberlândia (MG, Brazil), a prospective longitudinal study of 41 patients (21 adults and 20 children) was performed between December 2000 and March 2002. Microbiological monitoring was carried out by means of swabs collected from the oral cavity and rectum, screened by culturing in Salt Mannitol Agar plus 6 ?g/mL oxacillin. Selected samples were tested for susceptibility to glycopeptides, by the techniques of gel diffusion and dilution in agar, and for heteroresistance, by seeding with an inoculum at a density of 0.5 on the McFarland scale (108 CFU/mL) and performing a population analysis profile (PAP). A single nephropathy patient was colonized with a strain of vancomycin intermediate S. aureus (VISA) phenotype (MIC = 8 miug/mL). In twelve patients, heteroresistant staphylococci were isolated, corresponding to eight hVISA and four hVICoNS. The PAP study confirmed the presence of six hVISA and two hVICoNS. The presence of heteroresistant vancomycin samples may pose a potential risk in the future.

Hospital surface contamination in wards occupied by patients infected with MRSA or MSSA in a Brazilian university hospital

The hospital environment, especially surfaces, represents a secondary reservoir for pathogens such as Staphylococcus aureus. The present study was carried out at the Hospital de Clínicas da Universidade Federal de Uberlândia (HC-UFU) in Brazil, from January to August 2004, with the aim of qualitatively and quantitatively assessing the presence of S. aureus on surfaces touched by hands (bed rail, bedside table and door handle), on the floor and in the air, in wards where the patients were infected or not infected with this organism. Twenty-six wards with at least one infected patient and 26 wards with uninfected patients were investigated. Surfaces and air were sampled during bedmaking, by means of sterile 10cm2 adhesive tapes and 90mm-diameter exposed culture plates, respectively. Cultures were carried out on Egg Yolk Salt Agar, containing 7.5% NaCl and 1% egg yolk, and colonies identified by lecithinase and coagulase tests and Gramstain. About 50% of the wards were S. aureus contaminated, without significant differences between the groups (46.1% in the infected patient wards versus 53.8% in controls); the correlation between counts of the pathogen on the surfaces and in the air was 66.7%. Inspite of the fact that these bacteria were frequently present in the assessed wards, the microbial density waslow (less than 1 CFU/cm2). The association between environmental contamination and the epidemiology of S. aureus nosocomial infections is complex and thus further investigations are needed to reach a better understanding of this relationship.

Fecal loss and clearance of alpha-1-antitrypsin in children with persistent diarrhea

1. Daily fecal loss and daily clearance of alpha-1-antitrypsin were determined in 30 infants without intestinal disorders and in 21 with persistent diarrhea. 2. Stools were collected during a 48-h period and a randomly obtained single sample was also collected. Blood samples were also collected from the infants, and alpha-1-antitrypsin was measured by radial immunodiffusion in both stool and serum. 3. No difference in daily fecal loss (mg/d) of alpha-1-antitrypsin was detected between the control group and the group with persistent diarrhea (11 +/- 9.3 vs 18.5 +/- 20 mg/d). No difference in daily alpha-1-antitrypsin clearance (ml/d) was detected between the control group and the group with persistent diarrhea (4.3 +/- 3.6 vs 5.2 +/- 4.8 ml/d). 4. There was a strong correlation between daily fecal loss and daily clearance of alpha-1-antitrypsin (N = 50). There was a weak correlation between the concentrations of alpha-1-antitrypsin in randomly obtained single samples and daily fecal loss of the antiprotease (N = 25; r = -0.183; P < 0.01). 5. We conclude that: a) there is no increased fecal loss of alpha-1-antitrypsin persistent in diarrhea; b) fecal alpha-1-antitrypsin clearance is not necessary to estimate the enteric loss of the antiprotease; c) the determination of alpha-1-antitrypsin in random samples of feces is not a reliable method.

Etomidato e fentanil em cirurgia cardíaca / Etomidate and fentanyl in cardiac surgery

Estudaram-se os efeitos do etomidato como agente de induçäo em 20 pacientes submetidos à cirurgia cardíaca com circulaçäo extracorpórea. Verificou-se que os efeitos hemodinâmicos foram mínimos quando se empregou 50 micrograma.kg-1 de fentanil. Chama-se atençäo a utilizaçäo do flunitrazepam (0,03 mg.kg-1) como medicaçäo pré-anestésica, contribuindo para uma suave induçäo com etomidato. Concluiu-se que o etomidato é excelente opçäo para induçäo em pacientes portadores de coronariopatias e submetidos à cirurgia cardíaca