Mara Lucia Penna Queiroz

Isolation and serological identification of enteropathogenic Escherichia coli in pasteurized milk in Brazil

OBJECTIVE To evaluate the microbiological quality of pasteurized milk commercialized in Rio de Janeiro, Brazil, and determine serologically enteropathogenic Escherichia coli (EPEC) strains in E. coli isolates obtained from milk samples. METHODS Ninety samples of pasteurized milk - types B and C - of three different commercial brands, purchased in supermarkets and bakeries in Rio de Janeiro, were examined. The amount of total and fecal coliform bacteria was estimated using the Most Probable Number technique. Mesophilic, psychrotrophic, and thermoduric microorganism counts were determined by the Standard Plate Count technique. Isolation and identification of E. coli were carried out using conventional physiological tests. Commercial antisera were used for serological characterization of EPEC. RESULTS The three milk brands analyzed revealed bacterial counts above the regulated values of the Brazilian government. It was found that among 208 strains of E. coli isolated, 46 (22.1%) were serologically classified as EPEC. The most common EPEC serogroup was O55 (15.2%). CONCLUSIONS Though recent studies on virulence factors indicate that not all strains serologically classified as EPEC are able to attaching/effacing lesion, it is believed that the isolation of EPEC serogroups from pasteurized milk represent a potential risk for children, as well as an indicative of the presence of other enteropathogens.

Interactions of clinical and environmental Aeromonas isolates with Caco-2 and HT29 intestinal epithelial cells

Aim:  Evaluation of adherence and invasion of Aeromonas spp. to human colon carcinoma cell lines Caco‐2 and HT29 and assessment of cytotoxic activity.

Characterization of extended-spectrum beta-lactamases, antimicrobial resistance genes, and plasmid content in Escherichia coli isolates from different sources in Rio de Janeiro, Brazil.

We analyse the diversity of extended-spectrum beta-lactamases (ESBLs), antibiotic resistance genes, and plasmid content among Escherichia coli from a community and a hospital setting in Rio de Janeiro, Brazil. ESBL producers (CTX-M-2, CTX-M-9, CTX-M-59) belonged to different phylogroups/sequence types, and bla(CTX-M) were identified in IncA/C plasmids, reinforcing the possible intraplasmid evolution of bla(CTX-M-59) from bla(CTX-M-2) and the implication of IncA/C on bla(CTX-M) spread.

Antimicrobial resistance in Gram-negative bacilli isolated from infant formulas

A total of 90 samples of infant formula (IF) were collected from the lactary of a teaching hospital, during a 4-month period from July to August 1999. The sanitary conditions of the formulas were analyzed, and a physiological characterization of Gram-negative bacillus isolates and antimicrobial susceptibility testing were performed. Colony counts were considered to be unacceptable for the majority of the IF samples and the contamination rates were related to inadequate handling. Coliforms (35 degrees C and 45 degrees C growth) were detected in most of the IF tested. Klebsiella pneumoniae, Citrobacter freundii, Cedacea davisae, Klebsiella planticola and Enterobacter cloacae were the isolates most commonly identified. Antimicrobial susceptibility testing showed significant resistance rates, particularly to amoxicillin/clavulanic acid, cefoxitin, cephalotin or ampicillin. One extended-spectrum beta-lactamase-producing K. pneumoniae strain was also recovered.

First report of the emerging zoonotic agent Wohlfahrtiimonas chitiniclastica isolated from a retail frozen chicken in Rio de Janeiro, Brazil

Wohlfahrtiimonas chitiniclastica is an emerging zoonotic bacterium commensally living in larvae of particular flies. It has been associated with human and animal infections but never isolated from food. In the present study, a whole chicken carcass was rinsed in buffered peptone water which was then inoculated into BHI and the growth plated onto selective medium. Species identification was performed by MALDI–TOF MS. Those bacteria identified as W. chitiniclastica were subjected to 16S rRNA sequencing for confirmation and MEGA software was used to obtain their phylogenetic position. The findings of this study raise concerns regarding the abattoir, transport and stock practices of frozen meat carcasses and should be of interest with regard to microbiology, entomology and food production.

Avaliação Microbiológica, Detecção e Susceptibilidade Aos Antimicrobianos de Potenciais Enteropatógenos Das Famílias Enterobacteriaceae e Vibrionaceae em Mexilhões Perna Perna Coletados Na Praia de Itaipu, Niterói-Rj

Marcelly Miranda Aybal Jayme, Jorge Goncalo Caldeira Nunes de Matos, Alessandro Sales, Monica Conceicao NunesCarvalho, Mara Lucia Penna Queiroz, Angela Correa de Freitas-Almeida, Fabio Vieira Araujo.Avaliacao Microbiologica, Deteccao e Susceptibilidade Aos Antimicrobianos de Potenciais Enteropatogenos Das Familias Enterobacteriaceae e Vibrionaceae em Mexilhoes Perna Perna Coletados Na Praia de Itaipu, Niteroi-Rj. In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-185 Avaliacao Microbiologica, Deteccao e Susceptibilidade Aos Antimicrobianos de Potenciais Enteropatogenos Das Familias Enterobacteriaceae e Vibrionaceae em Mexilhoes Perna Perna Coletados Na Praia de Itaipu, Niteroi-RJ