Aims: The purpose of this study was to determine the susceptibility of Campylobacter jejuni and Campylobacter coli isolates to antimicrobial agents and to investigate the presence of plasmid DNA. Methods and Results: A total of 15 clinical isolates from children faeces, and 29 animal isolates of Campylobacter jejuni (n 22) and Campylobacter coli (n 22) were tested for susceptibility to 9 antimicrobial agents using a disc diffusion method, and screened for the presence of plasmid DNA by agarose gel electrophoresis. Of the 44 isolates, 56á8% were resistant to sulphonamide, 25% to nor¯oxacin, 18á2% to erythromicin, cipro¯oxacin and ampicillin, and 13á6% to tetracycline. All isolates were susceptible to gentamicin, chloramphenicol and cefotaxime. Plasmids were detected in one Camp. jejuni (4á54%) strain isolated from sheep and in six (27á27%) Camp. coli strains isolated from rhesus monkey(3), swine(2), and poultry(1) with sizes ranging from 3á4 to 50 kb. Conclusions: The majority of the human isolates were susceptible to antibiotics commonly used for the treatment of campylobacteriosis. Signi®cance and Impact of the Study: The origin and spread of Campylobacter resistance to antibiotics are discussed, with particular respect to the current situation in Brazil.

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The most common bacterial mercury resistance mechanism is based on the reduction of Hg(II) to Hg 0 , which is dependent of the mercuric reductase enzyme (MerA) activity. The use of a 431 bp fragment of a conservative region of the mercuric reductase (merA) gene was applied as a molecular marker of this mechanism, allowing the identification of mercury resistant bacterial strains.

Campylobacter coli is an important species involved in human cases of enteritis, and chickens are carriers of the pathogen mainly in developing country. The current study aimed to evaluate the transmission of C. coli and its pathogenic effects in chicken embryos. Breeder hens were inoculated intra-esophageally with C. coli isolated from chickens, and their eggs and embryos were analyzed for the presence of bacteria using real-time PCR and plate culture. The viability of embryos was verified. In parallel, SPF eggs were inoculated with C. coli in the air sac; after incubation, the embryos were submitted to the same analysis as the embryos from breeder hens. In embryos and fertile eggs from breeder hens, the bacterium was only identified by molecular methods; in the SPF eggs, however, the bacterium was detected by both techniques. The results showed no relationship between embryo mortality and positivity for C. coli in the embryos from breeder hens. However, the presence of bacteria is a cause of precocious mortality for SPF embryos. This study revealed that although the vertical transmission is a possible event, the bacteria can not grow in embryonic field samples.

A multiplex polymerase chain reaction (PCR)