title: Improvement of Karmali agar by addition of polymyxin B for the detection of Campylobacter jejuni and C. coli in whole-chicken carcass rinse.
abstract: The Karmali agar was modified by supplementation with a high concentration of polymyxin B. The goal of the study was to evaluate the effect of a high concentration of polymyxin B on the ability and selectivity of the modified Karmali agar to isolate Campylobacter jejuni and Campylobacter coli from whole chicken carcass rinse. A total of 80 whole chickens were rinsed with 400 mL of buffer peptone water. The rinsed samples were incubated with 2× blood-free modified Bolton enrichment broth for 48 h, and then streaked onto unmodified Karmali agar and modified Karmali agar supplemented with 100000 IU/L polymixin B (P-Karmali agar). The suspected colonies were finally confirmed by colony PCR. The P-Karmali agar exhibited a significantly better (P < 0.05) isolation rate than the unmodified Karmali agar (P-Karmali agar, 73.8%; unmodified Karmali agar, 33.8%). Moreover, the selectivity of the P-Karmali agar was also better (P < 0.05) than that of the other selective agar when comparing the number of contaminated plates (P-Karmali agar, 68.8%; unmodified Karmali agar, 87.5%) and growth index of competing flora (P-Karmali agar, 1.4; unmodified Karmali agar, 2.7). The improved selective agar excluded competing flora resistant to antibiotic agents in unmodified Karmali agar, increasing isolation rate and selectivity for C. jejuni and C. coli.
authors.affiliation: KU Center for Food Safety, College of Veterinary Medicine, Konkuk Univ., Seoul, The Republic of Korea.
authors.forename: Jung-Whan
authors.initials: JW
authors.lastname: Chon
authors.forename: Hyunsook
authors.initials: H
authors.lastname: Kim
authors.forename: Jin-Hyeok
authors.initials: JH
authors.lastname: Yim
authors.forename: Kwang-Young
authors.initials: KY
authors.lastname: Song
authors.forename: Jin-San
authors.initials: JS
authors.lastname: Moon
authors.forename: Young-Jo
authors.initials: YJ
authors.lastname: Kim
authors.forename: Kun-Ho
authors.initials: KH
authors.lastname: Seo
mesh_terms: D000362:Agar / Q000737:chemistry*; D000818:Animals; D002021:Buffers; D017000:Campylobacter coli / Q000302:isolation & purification*; D016123:Campylobacter jejuni / Q000302:isolation & purification*; D002645:Chickens / Q000382:microbiology*; D015169:Colony Count, Microbial; D003470:Culture Media / Q000737:chemistry; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D010461:Peptones / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011112:Polymyxin B / Q000737:chemistry*
chemical_list: D002021:Buffers; D003470:Culture Media; D010461:Peptones; D000362:Agar; D011112:Polymyxin B