title: Tetracycline Resistance Genes in Campylobacter jejuni and C. coli Isolated From Poultry Carcasses.
abstract: BACKGROUND
  Campylobacter is one of the leading bacterial species causing foodborne illnesses in humans. Antimicrobial agents have been extensively used for treatment of Campylobacter infections; but in the recent years, both animal and human isolates of this bacterium have shown resistance to several antibiotics such as tetracycline.
  
  
  OBJECTIVE
  The aim of this study was to investigate the presence of genetic determinants of tetracycline resistance in Campylobacter spp. recovered from poultry carcasses in Shiraz, Iran.
  
  
  METHODS
  Eighty-three thermophilic Campylobacter spp. Isolates were first identified based on multiplex polymerase chain reaction (PCR) and then screened for presence of tetracycline resistance genes (tet (A), tet (B), tet (O) and te (S)) by PCR.
  
  
  RESULTS
  The overall prevalence of Campylobacter jejuni and C. coli among the examined isolates was 51.8% and 48.2%, respectively. Tetracycline resistance genes of tet (B) and tet (S) were not seen among these Campylobacter spp. Isolates, whereas the most common tet gene identiﬁed was tet (O), found in 83.1% (69/83) of all the isolates. The tet (O) gene sequence comparison between C. jejuni and C. coli showed 100% similarity and these sequences (JX853721and JX853722) were also identical to the homologous sequences of other strains of Campylobacter spp. existing in the GenBank databases. In addition, tet (A) was found in 18% (15/83) of Campylobacter spp. isolates. To our knowledge, this represents the first report of tet (A) in Campylobacter spp. There was 100% homology between the sequences of tet (A) from this study (JX891463 and JX891464) and the tet (A) sequences mentioned for other bacteria in the GenBank databases.
  
  
  CONCLUSIONS
  The high prevalence of tet (O) resistance gene along with new detection of tet (A) resistance gene in Campylobacter spp. isolated from poultry carcasses revealed an extensive tetracycline resistance among Campylobacter isolates from poultry in Iran. It emphasized the need for cautious use of tetracycline in poultry production to decrease the extension of tetracycline-resistant Campylobacter spp.
authors.affiliation: Poultry Diseases Research Center, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran.
authors.forename: Bahman
authors.initials: B
authors.lastname: Abdi-Hachesoo
authors.affiliation: Department of Food Hygiene, Faculty of Veterinary Medicine, Amol University of Special Modern Technologies, Amol, IR Iran.
authors.forename: Rahem
authors.initials: R
authors.lastname: Khoshbakht
authors.affiliation: Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Sharifiyazdi
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Tabatabaei
authors.affiliation: Department of Food Hygiene and Public Health, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran.
authors.forename: Saeid
authors.initials: S
authors.lastname: Hosseinzadeh
authors.affiliation: Poultry Diseases Research Center, School of Veterinary Medicine, Shiraz University, Shiraz, IR Iran.
authors.forename: Keramat
authors.initials: K
authors.lastname: Asasi
keywords: Campylobacter; Tetracycline Resistance