Zoonotic Transmission of Campylobacter jejuni to Caretakers From Sick Pen Calves Carrying a Mixed Population of Strains With and Without Guillain Barré Syndrome-Associated Lipooligosaccharide Loci

Campylobacter jejuni Response When Inoculated in Bovine In Vitro Fecal Microbial Consortia Incubations in the Presence of Metabolic Inhibitors

Infection with the foodborne pathogen Campylobacter is the leading bacterial cause of human foodborne illness in the United States. The objectives of this experiment were to test the hypothesis that mixed microbial populations from the bovine rumen may be better at excluding Campylobacter than populations from freshly voided feces and to explore potential reasons as to why the rumen may be a less favorable environment for Campylobacter than feces. In an initial experiment, C. jejuni cultures inoculated without or with freshly collected bovine rumen fluid, bovine feces or their combination were cultured micro-aerobically for 48 h. Results revealed that C. jejuni grew at similar growth rates during the first 6 h of incubation regardless of whether inoculated with the rumen or fecal contents, with rates ranging from 0.178 to 0.222 h-1. However, C. jejuni counts (log10 colony-forming units/mL) at the end of the 48 h incubation were lowest in cultures inoculated with rumen fluid (5.73 log10 CFUs/mL), intermediate in cultures inoculated with feces or both feces and rumen fluid (7.16 and 6.36 log10 CFUs/mL) and highest in pure culture controls that had not been inoculated with the rumen or fecal contents (8.32 log10 CFUs/mL). In follow-up experiments intended to examine the potential effects of hydrogen and hydrogen-consuming methanogens on C. jejuni, freshly collected bovine feces, suspended in anaerobic buffer, were incubated anaerobically under either a 100% carbon dioxide or 50:50 carbon dioxide/hydrogen gas mix. While C. jejuni viability decreased <1 log10 CFUs/mL during incubation of the fecal suspensions, this did not differ whether under low or high hydrogen accumulations or whether the suspensions were treated without or with the mechanistically distinct methanogen inhibitors, 5 mM nitrate, 0.05 mM 2-bromosulfonate or 0.001 mM monensin. These results suggest that little if any competition between C. jejuni and hydrogen-consuming methanogens exists in the bovine intestine based on fecal incubations.

Genetic characteristics, antimicrobial susceptibility, and virulence genes distribution of Campylobacter isolated from local dual-purpose chickens in central China

Food-borne antibiotic-resistant Campylobacter poses a serious threat to public health. To understand the prevalence and genetic characteristics of Campylobacter in Chinese local dual-purpose (meat and eggs) chickens, the genomes of 30 Campylobacter isolates, including 13 C. jejuni and 17 C. coli from Jianghan-chickens in central China, were sequenced and tested for antibiotic susceptibility. The results showed that CC-354 and CC-828 were the dominant clonal complexes of C. jejuni and C. coli, respectively, and a phylogenetic analysis showed that three unclassified multilocus sequence types of C. coli were more closely genetically related to C. jejuni than to other C. coli in this study. Of the six antibiotics tested, the highest resistance rates were to ciprofloxacin and tetracycline (100%), followed by lincomycin (63.3%), erythromycin (30.0%), amikacin (26.7%), and cefotaxime (20.0%). The antibiotic resistance rate of C. coli was higher than that of C. jejuni. The GyrA T86I mutation and 15 acquired resistance genes were detected with whole-genome sequencing (WGS). Among those, the GyrA T86I mutation and tet(O) were most prevalent (both 96.7%), followed by the blaOXA-type gene (90.0%), ant(6)-Ia (26.7%), aac(6')-aph(3'') (23.3%), erm(B) (13.3%), and other genes (3.3%). The ciprofloxacin and tetracycline resistance phenotypes correlated strongly with the GyrA T86I mutation and tet(O)/tet(L), respectively, but for other antibiotics, the correlation between genes and resistance phenotypes were weak, indicating that there may be resistance mechanisms other than the resistance genes detected in this study. Virulence gene analysis showed that several genes related to adhesion, colonization, and invasion (including cadF, porA, ciaB, and jlpA) and cytolethal distending toxin (cdtABC) were only present in C. jejuni. Overall, this study extends our knowledge of the epidemiology and antibiotic resistance of Campylobacter in local Chinese dual-purpose chickens.

Triggers of Guillain-Barré Syndrome: Campylobacter jejuni Predominates

Guillain-Barré syndrome (GBS) is a rare immune-mediated acute polyradiculo-neuropathy that typically develops after a previous gastrointestinal or respiratory infection. This narrative overview aims to summarise and discuss current knowledge and previous evidence regarding triggers and pathophysiology of GBS. A systematic search of the literature was carried out using suitable search terms. The most common subtypes of GBS are acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). The most common triggers of GBS, in three quarters of cases, are previous infections. The most common infectious agents that cause GBS include Campylobacter jejuni (C. jejuni), Mycoplasma pneumoniae, and cytomegalovirus. C. jejuni is responsible for about a third of GBS cases. GBS due to C. jejuni is usually more severe than that due to other causes. Clinical presentation of GBS is highly dependent on the structure of pathogenic lipo-oligosaccharides (LOS) that trigger the innate immune system via Toll-like-receptor (TLR)-4 signalling. AIDP is due to demyelination, whereas in AMAN, structures of the axolemma are affected in the nodal or inter-nodal space. In conclusion, GBS is a neuro-immunological disorder caused by autoantibodies against components of the myelin sheath or axolemma. Molecular mimicry between surface structures of pathogens and components of myelin or the axon is one scenario that may explain the pathophysiology of GBS.