The spreading of diseases through foods is a worldwide concern. Here, molecular and in vitro cell-culture assays were employed to characterize 63 Brazilian Listeria monocytogenes isolates (food, 47; clinical, 16). Serotype 4b was the most predominant (49%) followed by (1/2)b (30%), (1/2)a (10%), (1/2)c (6%), 3c (3%) and 3b (2%). Ribotyping yielded 17 ribopatterns, which were grouped into four phylogenetic clusters. Cluster A comprised of 39/63 isolates primarily of food origin, and clusters B, C and D contained both food and clinical isolates. Isolates were positive for virulence determinants prfA, hlyA and inlA: clinical isolates were more invasive to Caco-2 cells and expressed high levels of inlA transcripts than the food isolates. Highly invasive isolates also provoked more Ped-2E9 cells to die by apoptosis than the weakly-invasive strains. These data demonstrate a strong genetic relatedness among clinical and food isolates and suggest transmission of a subset of L. monocytogenes strains from food to humans.

Considering the lack of information available in Brazil concerning listeriosis, the present study aimed to analyze phenotypic and genotypically Listeria monocytogenes clinical isolates from the Southwestern region of the State of São Paulo, Brazil. From January 1995 to May 2005, thirteen isolates of L. monocytogenes from twelve patients with listeriosis were sent to the Adolfo Lutz Institute (Campinas Regional Laboratory, São Paulo, Brazil). The antimicrobial susceptibility of the isolates was evaluated by the microdilution broth method for ampicillin, gentamicin, trimethoprim, sulfamethoxazole and vancomycin. They were also serotyped (Denka Seiken, Japan), and sub-typed by PFGE employing ApaI and AscI and the American CDC protocol. None of the isolates showed resistance to the antibiotics tested; however, seven of them presented increased values for sulfamethoxazole MICs. Ten isolates belonged to serotype 4b, two to serotype 1/2a and only one to serotype 1/2b. After digestion with ApaI and AscI, the strains were distributed in 3 different groups according to their profile. It was observed that the spatial or temporally unrelated strains exhibited similar PFGE profiles, indicating a possible clonal relationship among them.

The hemolytic, lecithinase or phosphatidylinositol-specific phospholipase C activities of Listeria monocytogenes can be used to differentiate this pathogenic bacteria from L. innocua, apathogenic, frequently isolated from environmental sources and food. However, the interpretation of these characteristics is problematic because of the variation in the expression of virulence factors by L. monocytogenes, which can be influenced by environmental conditions. We used a cheap, simple plate assay to monitor this expression in strains obtained from various sources and grown under different culture conditions. The results were increasingly significant and were obtained adding activated charcoal and different salts to the culture media, and in some cases changing the culture temperature, all with a rigorous control on the process of media sterilization.

A infecção humana por Salmonella Enteritidis está associada ao consumo de ovos crus ou mal cozidos e seus derivados e, a partir de 1993, emergiu como um problema de saúde pública no Brasil. Neste trabalho foram analisados os surtos por S. Enteritidis ocorridos entre os anos de 1995 e 2008 na região sudeste do Estado de São Paulo, bem como a importância da elaboração do inquérito epidemiológico para a sua elucidação. A análise conjunta de dados resultantes de análises de alimentos, coprocultura e dos inquéritos recebidos pelo laboratório mostrou a ocorrência de 167 surtos positivos para S. Enteritidis, dos quais foram obtidos 59 (35,3%) inquéritos epidemiológicos. Do total de surtos, 48 (28,7%) foram elucidados somente pela análise de alimentos; 25 (15%) pela análise de alimentos e coprocultura, e 94 (56,3%) somente por coprocultura. Dentre os alimentos envolvidos nos surtos, o mais frequente foi a maionese caseira (58,2%). Verifica-se a continuidade no desconhecimento da população em relação ao consumo de alimentos que contenham ovos crus ou mal cozidos e a necessidade de introduzir melhorias na investigação epidemiológica dos surtos, para que se possa identificar a fonte de infecção no maior número possível dessas ocorrências.

We describe the draft genome sequence of the clinical Vibrio vulnificus strain 03_7315, isolated in 2016 from the blood of a diabetic patient who died of septicemia after ingestion of seafood. The draft genome, with 4,755,588 bp covering two chromosomes, presented 4,434 genes, 4,213 coding sequences, and 117 pseudogenes.