Comparative analysis of Campylobacter spp. isolated from wild birds and chickens using MALDI-TOF, 16S rDNA PCR/sequencing, and conventional biochemical testing

Rapid, accurate diagnosis and differentiation of bacterial pathogens potentially shared among wildlife, domestic animals, and humans is an essential function of microbiology diagnostic laboratories. While conventional... [ view full abstract ]

Rapid, accurate diagnosis and differentiation of bacterial pathogens potentially shared among wildlife, domestic animals, and humans is an essential function of microbiology diagnostic laboratories. While conventional biochemical methods are still widely used, MALDI-TOF is increasingly used as a front-line diagnostic tool for identification and differentiation at the genus, species, and strain level. Wild birds are commonly infected with Campylobacter, and the sharing of habitat by backyard poultry and wild birds provides a potential route of entry for strains to infect chickens and humans. This studied aimed to determine if MALDI-TOF accurately identifies, to a species level, Campylobacter from wild birds and backyard chickens. In this study, we compared MALDI-TOF, conventional biochemical methods, and 16s rRNA and hippurate gene sequencing for species level identification of Campylobacter isolates obtained from backyard chickens (n=8), and wild American crows (Corvus americana, n=17), Mallard duck (Anas platyrhynchos, n=1), and Western Scrub Jay (Aphelocoma californica, n=1). There was 100% agreement between MALDI-TOF and the combined results of 16s rRNA and hippurate gene sequencing (P=0.0027, Kappa =1), while biochemical testing alone mis-classified 5 isolates of C. jejuni as C. coli (P = 0.1573, Kappa = 0.0857). These results confirm that MALDI-TOF is a fast, reliable way to identify and differentiate Campylobacter species from wild birds and chickens.