title: Modification of Karmali agar by supplementation with potassium clavulanate for the isolation of Campylobacter from chicken carcass rinses.
abstract: The detection ability and selectivity of Karmali agar was improved by supplementation of an extended-spectrum β-lactamase inhibitor, potassium clavulanate. The optimum concentration of potassium clavulanate (0.5 μg/ml) in Karmali agar was determined by inoculation of 50 Campylobacter and 30 extended-spectrum β-lactamase-producing E. coli strains onto normal and modified Karmali agar containing various concentrations of the agent. Eighty retail carcasses were rinsed with 400 ml of buffered peptone water. The rinse samples were enriched in 2 × blood-free Bolton enrichment broth at 42°C for 48 h and then were streaked onto normal and modified Karmali agar containing 0.5 μg/ml potassium clavulanate. The suspicious colonies were subcultured on Columbia blood agar and confirmed by colony PCR. In chicken carcass samples, the modified Karmali agar showed a significantly greater isolation rate than normal Karmali agar (42.5 versus 21.3%; P < 0.05). Furthermore, the selectivity of the modified Karmali agar was also significantly higher (P < 0.05) than that of the normal Karmali agar, as seen by comparison of the number of contaminated agar plates (83.8 versus 97.5%) and the growth index (1.67 versus 2.91) of the non-Campylobacter colonies.
authors.affiliation: College of Veterinary Medicine, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Jung-Whan
authors.initials: JW
authors.lastname: Chon
authors.affiliation: College of Veterinary Medicine, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Hong-Seok
authors.initials: HS
authors.lastname: Kim
authors.affiliation: College of Veterinary Medicine, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Dong-Hyeon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: College of Veterinary Medicine, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Hyunsook
authors.initials: H
authors.lastname: Kim
authors.affiliation: College of Veterinary Medicine, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Choi
authors.affiliation: Department of Food Science and Biotechnology and Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, Kangwon 200-701, Republic of Korea.
authors.forename: Deog-Hwan
authors.initials: DH
authors.lastname: Oh
authors.affiliation: College of Veterinary Medicine, Konkuk University, Seoul 143-701, Republic of Korea. bracstu3@konkuk.ac.kr.
authors.forename: Kun-Ho
authors.initials: KH
authors.lastname: Seo
mesh_terms: D000362:Agar / Q000737:chemistry; D000818:Animals; D002167:Campylobacter / Q000254:growth & development* / Q000302:isolation & purification* / Q000378:metabolism; D002645:Chickens; D019818:Clavulanic Acid / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry* / Q000378:metabolism; D005516:Food Microbiology; D008460:Meat / Q000382:microbiology*; D016133:Polymerase Chain Reaction
chemical_list: D003470:Culture Media; D019818:Clavulanic Acid; D000362:Agar