Antimicrobial resistance and plasmid profiles of Campylobacter jejuni and Campylobacter coli from human and animal sources

Abstract

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.

Antimicrobial susceptibility of Campylobacter sp strains isolated from calves with and without diarrhea in Minas Gerais state, Brazil

“…In Brazil, some studies (9,17,24) show the occurrence of strains resistant to tetracycline. However, Aquino et al (4) did not find any Campylobacter sp strain isolated from men resistant to this antibiotic, but they reported resistance in strains isolated from swine. In the present study, 8% of the tested strains were moderately susceptible and 24% were resistant to this antibiotic, what is a remarkable finding, because tetracycline is one of the drugs of choice for treatment of C. jejuni and C. coli enteric infections.…”

Campylobacter

“…resulted in the emergence of the corresponding resistant isogenic strains suggesting that this organism is hypermutatable under these conditions [87]. Horizontal transfer of such resistance determinants (acquisition) together with any genetic modification of pre-existing genes through point mutations (intrinsic) or some other genetic event, are thought to be the main mechanisms contributing to bacterial resistance [2,10,140]. Self-transmissible elements including plasmids, transposons and bacteriophage all facilitate the acquisition and subsequent dissemination of resistance determinants.…”

“…from a Gram-positive coccus, and that divergence occurred over time. More recently, in Brazil, only 15.9% of the isolates analysed for plasmids contained these mobile elements and none of the tetracycline resistant strains were found to harbour plasmid DNA [10]. Chloramphenicol resistance, although rare in campylobacters [10], has also been reported to be plasmid mediated [140].…”

“…More recently, in Brazil, only 15.9% of the isolates analysed for plasmids contained these mobile elements and none of the tetracycline resistant strains were found to harbour plasmid DNA [10]. Chloramphenicol resistance, although rare in campylobacters [10], has also been reported to be plasmid mediated [140]. A chloramphenicol resistance determinant cloned from a C. coli plasmid was sequenced and found to have 43 and 57% homology with chloramphenicol acetyltransferase (CAT) proteins from other Gram-positive and -negative origins [186].…”

“…Horizontal gene transfer is a significant mechanism for disseminating antimicrobial resistance among unrelated bacterial populations [10,126]. Integron structures play a pivotal role and have been identified in several Gram-negative bacterial species including food-borne pathogens, such as Salmonella spp., E. coli and Shigella spp.…”