Campylobacter coli strains from Brazil can invade phagocytic and epithelial cells and induce IL-8 secretion

Campylobacter spp. have been a predominant cause of bacterial foodborne gastroenteritis worldwide, causing substantial costs to public healthcare systems. This study aimed to assess the invasion and pro-inflammatory cytokine production capacity of Campylobacter coli strains isolated in Brazil. A total of 50 C. coli isolated from different sources in Brazil were analyzed for their capacity of invasion in Caco-2 and U-937 cell lines. The production of pro-inflammatory cytokines was quantitatively measured in response to C. coli. All the strains studied showed invasion percentage ≥ 40% in polarized Caco-2 cells. In U-937 cells assay, 35 of 50 C. coli strains studied showed invasion percentage ≥ 50%. A significant increase in IL-8 production by infected U-937 cells was observed for 17.5% of the C. coli isolates. The high percentages of invasion in Caco-2 and U-937 cells observed for all studied strains, plus the increased production of IL-8 by U-937 cells against some strains, highlighted the pathogenic potential of the C. coli studied and bring extremely relevant data since it has never been reported for strains isolated in Brazil and there are a few data for C. coli in the literature.

Molecular Epidemiology and Resistance Profile of Campylobacter jejuni and Campylobacter coli Strains Isolated from Different Sources in Brazil

Aims: The objectives of this study were to genotype a total of 48 Campylobacter jejuni and 39 Campylobacter coli strains isolated in Brazil from 1995 to 2016 by multilocus sequence typing (MLST) and to determine their resistance profile. The presence or points of mutation in the related resistance genes was verified. Results: By MLST, C. jejuni strains were typed into 36 STs and C. coli strains were typed into 27 STs. A total of 70.8% of C. jejuni and 35.9% of C. coli were resistant to at least one antimicrobial tested. The tet(O) gene was detected in 43.7% C. jejuni and in 12.8% C. coli. The ermB gene was not detected and one C. jejuni presented the mutation in the 23S rRNA gene. Besides, 58.3% C. jejuni presented the substitution T86I in the quinolone resistance-determining region of gyrA and 15.4% C. coli presented the substitution T38I. The cmeB gene was detected in 97.9% C. jejuni and in 97.4% C. coli. Conclusion: The presence of C. jejuni and C. coli resistant to some antimicrobial agents of clinical use is of public health concern. The presence of STs shared between Brazilian strains and isolates of different countries is of concern since it might suggest a possible spread of these shared types.

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

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 under diagnosed 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.