title: Characterization of Staphylococcus xylosus isolated from broiler chicken barn bioaerosol.
abstract: In this study we isolated and characterized Staphylococcus xylosus, a coagulase-negative staphylococcal species considered as commensal and one of the prevalent staphylococcal species found in poultry bioaerosol. Isolates were obtained using air samplers and selective phenylethyl alcohol agar for gram-positive bacteria during 35-d periods at different times of the day. A total of 200 colonies were recovered and after basic biochemical tests were performed, presumptive staphylococci were subsequently identified by API Staph strips. A total of 153 (76.5%) staphylococci were found, among which 84 were S. xylosus (46 and 38 isolated inside and outside, respectively). Biofilm formation was observed in 86.9% of S. xylosus isolates, whereas 79.8% of them showed hemolytic activity. There was a strong correlation (92.5%) between biofilm formation and hemolytic activity. All 84 S. xylosus isolates were susceptible to amikacin, ampicillin/sulbactam, chloramphenicol, ciprofloxacin, gentamycin, kanamycin, linezolid, trimethoprim/sulfamethoxazole, and vancomycin. Resistance to nalidixic acid (86.9%), novobiocin (85.7%), penicillin (70.2%), lincomycin (46.4%), oxacillin (42.9%), ampicillin (27.4%), tetracycline (21.4%), erythromycin (11.9%), bacitracin (10.7%), and streptomycin (2.4%) was observed among the isolates. Resistance to tetracycline, lincomycin, erythromycin, and β-lactam antibiotics was occasionally linked to the tetK, linA, ermB, and blaZ genes, respectively. Random amplification of polymorphic DNA results showed similarity of 15 to 99% between isolates collected outside and inside the barn, indicating genetic diversity of these isolates. Our study indicates that characterization of poultry bioaerosol coagulase-negative staphylococcal species such as S. xylosus is necessary for assessing their safety status for both poultry and humans.
authors.affiliation: Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Agassiz, BC, Canada V0M 1A0; and.
authors.forename: Javier
authors.initials: J
authors.lastname: Vela
authors.forename: Kelsie
authors.initials: K
authors.lastname: Hildebrandt
authors.forename: Andrew
authors.initials: A
authors.lastname: Metcalfe
authors.forename: Heidi
authors.initials: H
authors.lastname: Rempel
authors.forename: Shabtai
authors.initials: S
authors.lastname: Bittman
authors.forename: Edward
authors.initials: E
authors.lastname: Topp
authors.forename: Moussa
authors.initials: M
authors.lastname: Diarra
mesh_terms: D000336:Aerosols; D000391:Air Microbiology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002645:Chickens; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial; D006799:Housing, Animal; D011110:Polymorphism, Genetic; D013045:Species Specificity; D013210:Staphylococcus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D059467:Transcriptome
chemical_list: D000336:Aerosols; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial