Comparison of loop-mediated isothermal amplification assay and conventional culture methods for detection of Campylobacter jejuni and Campylobacter coli in naturally contaminated chicken meat samples.
We investigated the efficacy of a loop-mediated isothermal amplification (LAMP) assay for detection of chicken meat samples naturally contaminated with Campylobacter jejuni and Campylobacter coli. A total of 144 Preston enrichment broth cultures from chicken meat samples were assessed by using the LAMP assay and conventional culture methods, which consist of a combination of Preston enrichment culturing and plating onto Butzler and modified charcoal cefoperazone deoxycholate agars. Compared with C. jejuni-C. coli isolation using the conventional culture test, the LAMP results showed 98.5% (67/68) and 97.4% (74/76) sensitivity and specificity, respectively, and the positive and negative predictive values were 97.1% (67/69) and 98.7% (74/75), respectively. The conventional culture test required more than 3 to 4 days to isolate and identify C. jejuni and C. coli in the Preston enrichment cultures. In contrast, the LAMP assay was markedly faster, requiring less than 90 min from the beginning of DNA extraction to final detection and differentiation of C. jejuni and C. coli. In total, the LAMP assay required 23.5 to 25.5 h from the beginning of the enrichment culture to final determination. These results suggest that our LAMP assay is a powerful tool for rapid, sensitive, and practical detection of C. jejuni and C. coli which may facilitate surveillance and control of C. jejuni-C. coli contamination in chicken, as well as investigations of food poisoning incidents caused by these organisms. This is the first report of a highly sensitive and specific LAMP assay to detect and differentiate C. jejuni and C. coli in chicken meat samples.
Yamazaki
Wataru
W
Division of Bacteriology, Osaka Prefectural Institute of Public Health, 1-3-69 Nakamichi, Higashinari-ku, Osaka 537-0025, Japan. wataru@iph.pref.osaka.jp
Taguchi
Masumi
M
Kawai
Takao
T
Kawatsu
Kentaro
K
Sakata
Junko
J
Inoue
Kiyoshi
K
Misawa
Naoaki
N
D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods*; D017000:Campylobacter coli / Q000302:isolation & purification*; D016123:Campylobacter jejuni / Q000302:isolation & purification*; D002645:Chickens; D008460:Meat / Q000382:microbiology*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors