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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #325315

Title: Discriminative power of Campylobacter phenotypic and genotypic typing methods.

item DUARTE, ALEXANDRA - Ghent University
item SELIWIORSTOW, TOMASZ - Ghent University
item Miller, William - Bill
item DE ZUTTER, LIEVEN - Ghent University
item UYTTENDAELE, MIEKE - Ghent University
item DIERICK, KATELIJNE - Scientific Institute Of Public Health
item BOTTELDOORN, NADINE - Scientific Institute Of Public Health

Submitted to: Journal of Microbiological Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2016
Publication Date: 3/18/2016
Citation: Duarte, A., Seliwiorstow, T., Miller, W.G., De Zutter, L., Uyttendaele, M., Dierick, K., Botteldoorn, N. 2016. Discriminative power of Campylobacter phenotypic and genotypic typing methods. Journal of Microbiological Methods. 125:33-39.

Interpretive Summary: The food-borne pathogen Campylobacter is a natural contaminant of most birds and livestock. Multiple typing methods exist for Campylobacter; however, the effectiveness of these typing methods depends on the size and identity of the sample set. Here, five typing methods were tested, alone and in pair-wise combinations, on a set of Campylobacter jejuni and Campylobacter coli strains isolated from chicken broiler carcasses in Belgium. The discriminatory power of each typing method varied, as expected. A DNA sequencing-based method, MLST, was the most discriminatory typing method. The addition of a second typing method, essentially adding an eighth DNA sequence to the MLST set of seven, slightly improved the typing capability of MLST. Since MLST is an easy typing method, readily available to and commonly used by clinical labs, use of this method is recommended for epidemiological surveillance of the food supply and outbreak investigations.

Technical Abstract: The aim of this study was to compare typing methods, individually and combined, to use in the routine surveillance of Campylobacter in broiler carcasses. C. jejuni (n=94) and C. coli (n=52) isolated from different broiler carcasses were characterized using different typing methods: multilocus sequence typing (MLST), flagellin gene A restriction fragment length polymorphism typing (flaA-RFLP), antimicrobial resistance profiling (AMRp), presence/absence of 5 putative virulence genes; and, exclusively for C. jejuni, determination of lipooligosaccharide (LOS) class. Discriminatory power was calculated by the Simpson’s index of diversity (SID) and the congruence was measured by the adjusted Rand index and adjusted Wallace coefficient. MLST was individually the most discriminative typing method for both C. jejuni (SID = 0.981) and C. coli (SID = 0.957). The most discriminative combination for both C. jejuni and C. coli with a SID of 0.992 was obtained by combining MLST with flaA-RFLP. The combination of MLST with flaA-RFLP is an easy and feasible typing method for short term surveillance.