Escherichia coli strains that cause nonbloody diarrhea in infants are known to present three distinct patterns of adherence to epithelial cells, namely, localized (LA), diffuse (DA), and aggregative (AA) adherence. Strains with LA (typical EnteropathogenicEscherichia coli [EPEC]) are well recognized as a cause of secretory diarrhea, but the role of strains with DA (DAEC) is controversial, and strains with AA (EAEC) have been more frequently related to persistent diarrhea whereas its relationship with acute diarrhea is not well defined. To determine the relationship of the different types of E. coli adherence patterns with acute diarrhea (lasting less than 14 days) and persistent diarrhea (lasting more than 14 days) in São Paulo, Brazil, we studied stool specimens from 40 infants under 1 year of age with diarrhea and 40 age-matched control infants without any gastrointestinal symptoms. Twenty-eight (35.0%) of eighty cases yielded adherent E. coli (HEp-2 cells). Strains with localized and aggregative adherence were associated with acute and persistent diarrhea. A total of 11.2% of the adherent strains were typical EPEC serotypes and hybridized with the enteroadherence factor probe; 5.0% were EAEC and hybridized with the EAEC probe. DAEC strains were isolated from 10.0% of patients and 7.5% of controls and did not hybridize with the two probes used (daaC and AIDA-I). Strains with a localized adherence-like pattern (atypical EPEC) were found significantly more frequently (P = 0.028) in cultures from children with diarrhea (17.5%) than in controls (2.5%).

In a prospective study carried out in two urban centers in northeastern Brazil, 195 HEp-2-adherent Escherichia coli strains were isolated; 110 were identified as the only pathogen in stools of children with diarrhea, and 85 were from controls. Enteropathogenic E. coli isolates were identified in 21 children with diarrhea (8.9%) and 7 children without diarrhea (3.0%), and they were significantly associated with diarrhea (P < 0.01). Enteroaggregative E. coli strains were isolated from 40 children with diarrhea (16.9%) and 38 children without diarrhea (16.4%) and showed no correlation with diarrhea (P > 0.5). In 49 children with diarrhea (20.7%) and 40 children without diarrhea (17.3%), diffusely adherent E. coli (DAEC) isolates were detected and were not found to be associated with diarrhea (P ‫؍‬ 0.41). However, after stratification, for children older than 12 months of age a significant correlation between DAEC infection and diarrhea was detected (P ‫؍‬ 0.01). These results suggest that DAEC isolates should be considered potential pathogens in northeastern Brazil and also confirm the association of DAEC with age-dependent diarrhea.Diarrhea remains an important public health problem for children in developing areas of northeastern Brazil. The bacterial pathogen most commonly associated with endemic forms of childhood diarrhea is Escherichia coli. At least five categories of diarrheagenic E. coli strains are recognized on the basis of distinct epidemiological and clinical features, specific virulence determinants, and an association with certain serotypes: enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli (EHEC), and enteroaggregative E. coli (EAEC) (13). Recently, diffusely adherent E. coli (DAEC) strains have been recognized as the sixth class of diarrheagenic E. coli and appear as a heterogeneous group (13). EPEC, EAEC, and DAEC isolates are characterized by their distinct patterns of adherence to cultured epithelial cells in vitro. EPEC strains bind to host cells in a pattern called localized adherence (LA), in which microcolonies form on the surfaces of the cells (15). EAEC isolates bind in an aggregative adherence (AA) pattern, which is characterized by a stacked brick-like arrangement on the surfaces of the cells as well as those of glass or plastic containers (13). DAEC strains are defined by a pattern of diffuse adherence (DA), in which the bacteria uniformly cover the entire cell surface (15). The implication of DAEC strains in diarrhea remains controversial, since some studies have reported that these strains are found similarly in children with and without diarrhea (6, 8). Tacket et al. (18) were unable to conclusively induce diarrhea with DAEC in adult volunteers but suggested that DAEC may cause disease in immunologically naive or malnourished children. Discrepancies among epidemiological studies could be explained by age-dependent susceptibility to diarrhea or by the use of an inappropriate detection method such as DNA probing ...

We evaluated the performance of several methods for the detection of methicillin resistance in Staphylococcus aureus using 101 clinical S. aureus isolates from pediatric patients in a tertiary hospital in Brazil; 50 isolates were mecA-positive and 51 were mecA-negative. The Etest and oxacillin agar screening plates were 100% sensitive and specific for mecA presence. Oxacillin and cefoxitin disks gave sensitivities of 96 and 92%, respectively, and 98% specificity. Alterations of CLSI cefoxitin breakpoints increased sensitivity to 98%, without decreasing specificity. Our results highlight the importance of a continuing evaluation of the recommended microbiological methods by different laboratories and in different settings. If necessary, laboratories should use a second test before reporting a strain as susceptible, especially when testing strains isolated from invasive or serious infections. With the new (2007) CLSI breakpoints, the cefoxitin-disk test appears to be a good option for the detection of methicillin resistance in S. aureus.

SUMMARYMethicillin-resistant Staphylococcus aureus (MRSA) are now a worldwide problem. Cystic fibrosis (CF) patients are commonly colonized and infected by MRSA. Accurate oxacillin susceptibility testing is mandatory for the adequate management of these patients. We performed a comparison of the accuracy of different tests in CF isolates, including methicillin-susceptible S. aureus and MRSA with different SCCmec types, and using the mecA gene as the gold-standard. The sensitivity and specificity of oxacillin disc, Etest, and oxacillin agar screening plate were 100%. Sensitivity of the cefoxitin disc was 85% and specificity was 100%. For clinically relevant isolates, laboratories may consider the use of a combination of two phenotypic methods.

A contaminação de hemocomponentes por bactérias presentes na pele do doador de sangue pode levar à infecção pós-transfusional no receptor da transfusão. O objetivo deste estudo foi avaliar a eficiência de quatro produtos antissépticos utilizados na antissepsia da pele do antebraço de doadores de sangue. Avaliamos 363 doadores que foram distribuídos em quatros grupos (A a D) de acordo com o produto utilizado. Grupo A: álcool e tintura de iodo; grupo B: álcool e clorexidine; grupo C: álcool e grupo D: álcool e polivilpirrolidona (PVPI). Foram realizadas culturas de swabs de pele antes e após a aplicação dos produtos e hemocultura do sangue coletado para avaliação da contaminação bacteriana. Observamos que os grupos A (82/94) e D (68/ 78), bem como a associação dos grupos B (69/91) e C (72/100) foram semelhantes quanto ao nível de redução bacteriana pré e pós-aplicação dos antissépticos. Houve maior redução no número de colônias bacterianas nos grupos A e D quando comparados ao B e C (p<0,001). Apenas uma amostra apresentou positividade na hemocultura. Concluímos que os produtos dos grupos A (álcool e tintura de iodo) e D (álcool e PVPI) apresentaram melhor eficiência na antissepsia de pele em doadores de sangue. Rev.

Mupirocin is a topical antimicrobial agent and part of most Staphylococcus aureus decolonization regimens. Thus, knowing the mupirocin susceptibility profile of colonizing S. aureus is paramount for the proper use of this agent. We evaluated S. aureus isolates from 128 colonized children, using disc diffusion (with 5 mcg and 200 mcg discs) and Etest. None were low-level or high-level mupirocin-resistant. Since mupirocin will be increasingly needed for the control of S. aureus infection, continuous monitoring of its susceptibility status is necessary.

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