Genotyping of Campylobacter coli strains isolated in Brazil suggests possible contamination amongst environmental, human, animal and food sources

Abstract

Campylobacter coli and Campylobacter jejuni are two of the most common causative agents of food-borne gastroenteritis in numerous countries worldwide. In Brazil, campylobacteriosis is underdiagnosed and under-reported, and few studies have molecularly characterized Campylobacter spp. in this country. The current study genotyped 63 C. coli strains isolated from humans (n512), animals (n521), food (n510) and the environment (n520) between 1995 and 2011 in Brazil. The strains were genotyped using pulsed-field gel electrophoresis (PFGE), sequencing the short variable region (SVR) of the flaA gene ( flaA-SVR) and high-resolution melting analysis (HRMA) of the clustered regularly interspaced short palindromic repeat (CRISPR) locus to better understand C. coli genotypic diversity and compare the suitability of these three methods for genotyping this species. Additionally, the discrimination index (DI) of each of these methods was assessed. Some C. coli strains isolated from clinical and non-clinical origins presented $80 % genotypic similarity by PFGE and flaA-SVR sequencing. HRMA of the CRISPR locus revealed only four different melting profiles. In total, 22 different flaA-SVR alleles were detected. Of these, seven alleles, comprising gt1647-gt1653, were classified as novel. The most frequent genotypes were gt30 and gt1647.This distribution reveals the diversity of selected Brazilian isolates in comparison with the alleles described in the PubMLST database. The DIs for PFGE, flaA-SVR sequencing and CRISPR-HRMA were 0.986, 0.916 and 0.550, respectively. PFGE and flaA-SVR sequencing were suitable for subtyping C. coli strains, in contrast to CRISPR-HRMA. The high genomic similarity amongst some C. coli strains confirms the hypothesis that environmental and food sources potentially lead to human and animal contamination in Brazil.

Molecular determination of genetic diversity among Campylobacter jejuni and Campylobacter coli isolated from milk, water, and meat samples using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR)

“…Campylobacters are commensal members of the gut microbiota of livestock, poultry [ 1 ], wild birds [ 2 ], and are also found in aquatic milieu [ 3 ]. Several Campylobacter species are known to cause infections and campylobacteriosis are largely caused by C. coli and C. jejuni [ 4 , 5 ]. Campylobacteriosis cases have been reported in several parts of the world including South America, Africa, North America, Asia, and Europe [ 6 ].…”

“…Campylobacteriosis cases have been reported in several parts of the world including South America, Africa, North America, Asia, and Europe [ 6 ]. Campylobacteriosis is usually associated with consumption of contaminated vegetables, fruits, raw milk, untreated water, foodstuffs, and undercooked meats [ 4 ]. About 50%–80% of human campylobacteriosis cases are caused by chicken consumption [ 7 ].…”

“…In developing countries, C. jejuni and C. coli are the two major Campylobacter species known as potential etiological agents of acute diarrhea especially in children [ 10 ]. Campylobacter infections are ecologically diverse [ 11 ] and as a result of the burdens and public health impact of Campylobacter species, studies on epidemiological analyses, genetic diversity, and similarity of these bacteria species are very significant [ 4 ]. Hence, molecular typing techniques are used for the determination of the similarities of isolates and these have shown in better detection of Campylobacter strains [ 12 ].…”

Molecular typing of Campylobacter jejuni strains: comparison among four different techniques

“…Agarose blocks were prepared with each 111 C. jejuni strains studied using the CDC PulseNet protocol for C. jejuni [8]. The plugs were digested with 40 U of SmaI (Life Technologies, Carlsbad, CA, USA) at 25°C for 2 h. Macrorestriction fragments were resolved by counter-clamped homogeneous electric field electrophoresis in a CHEF-DR III apparatus (Bio-Rad Laboratories) as described in details by Gomes et al [25]. The pulse times were ramped from 6.8 to 35.4 s over 19 h, as described by Ribot et al [8].…”

Genome sequencing and annotation of a Campylobacter coli strain isolated from milk with multidrug resistance

“…Recently the role of C . coli in human disease has been increasingly recognized as it accounts for up to 25% of the total Campylobacter -associated diarrhea and has been reported to cause bacteremia, meningitis, spontaneous abortion and community acquired inflammatory enteritis [2] , [3] , [4] . Despite the application of Whole Genome Sequencing (WGS) on Campylobacter isolates, especially C .…”