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

Insights on the genomic diversity, virulence and resistance profile of a Campylobacter jejuni strain isolated from a hospitalized patient in Brazil

Campylobacteriosis is currently recognized as one of the major causes of foodborne bacterial diseases worldwide. In Brazil, there is insufficient data to estimate the impact of Campylobacter in public health. The aim of this present study was to characterize a C. jejuni CJ-HBSJRP strain isolated from a hospitalized patient in Brazil by its ability to invade human Caco-2 epithelial cells, to survive in U937 human macrophages, and to assess its phenotypic antimicrobial resistance profile. In addition, prophages, virulence and antimicrobial resistance genes were search using whole-genome sequencing data. The genetic relatedness was evaluated by MLST and cgMLST analysis by comparison with 29 other C. jejuni genomes isolated from several countries. The CJ-HBSJRP strain showed an invasion percentage of 50% in Caco-2 polarized cells, 37.5% of survivability in U937 cells and was phenotypically resistant to ampicillin, ciprofloxacin and nalidixic acid. A total of 94 virulence genes related to adherence, biofilm, chemotaxis, immune modulation, invasion process, metabolism, motility and toxin were detected. The resistance genes blaOXA-605 (blaOXA-61), cmeB and mutations in the QRDR region of gyrA were also found and none prophages were detected. The MLST analysis showed 23 different STs among the strains studied. Regarding cgMLST analysis, the CJ-HBSJRP strain was genetically distinct and did not group closely to any other isolate. The results obtained reinforce the pathogenic potential of the CJHBSJRP strain and highlighted the need for more careful attention to Campylobacter spp. infections in Brazil since this pathogen has been the most commonly reported zoonosis in several countries worldwide.

Correlation between Multilocus Sequence Typing and Antibiotic Resistance, Virulence Potential of Campylobacter jejuni Isolates from Poultry Meat

Campylobacter jejuni is a major foodborne pathogen and can be transmitted to human beings via the consumption of poultry products. This study aimed to determine antibiotic resistance and virulence potential of one hundred C. jejuni isolates from poultry meat and to explore the correlation between them and the multilocus sequence types (MLST). A total of 29 STs and 13 CCs were identified by MLST, of which 8 STs were first identified. The dominant ST was ST583 (21%), followed by ST42 (15%), ST61 (12%), and ST2276 (10%). Eighty-eight isolates showed resistance to at least one antibiotic. The resistance rate to fluoroquinolones was the highest (81%), followed by tetracycline (59%), whereas all the isolates were susceptible to erythromycin and telithromycin. Multi-antibiotic resistance was detected in 18 C. jejuni isolates. Great variability in the adhesion and invasion ability to Caco-2 cells was observed for the 100 isolates, with adhesion rates varying between 0.02% and 28.48%, and invasion rates varied from 0 to 6.26%. A correlation between STs and antibiotic resistance or virulence was observed. The ST61 isolates were significantly sensitive to CIP, while the TET resistance was significantly associated with ST354 and ST6175 complex. ST11326 showed substantially higher resistance to gentamicin and higher adhesion and invasion abilities to Caco-2 cells. The results helped improve our understanding of the potential hazard of different genotypes C. jejuni and provided critical information for the risk assessment of campylobacteriosis infection.