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Improvement of Karmali Agar by Addition of Polymyxin B for the Detection of Campylobacter jejuni and C. coli in Whole‐Chicken Carcass Rinse
Author(s) -
Chon JungWhan,
Kim Hyunsook,
Yim JinHyeok,
Song KwangYoung,
Moon JinSan,
Kim YoungJo,
Seo KunHo
Publication year - 2013
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/1750-3841.12096
Subject(s) - agar , campylobacter jejuni , campylobacter , polymyxin b , microbiology and biotechnology , isolation (microbiology) , agar plate , food science , biology , bacteria , antibiotics , genetics
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 1 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 .