Molecular Evidence for the Thriving of Campylobacter jejuni ST-4526 in Japan

Abstract

Campylobacter jejuni is a leading cause of human gastroenteritis worldwide. This study aimed at a better understanding of the genetic diversity of this pathogen disseminated in Japan. We performed multilocus sequence typing (MLST) of Campylobacter jejuni isolated from different sources (100 human, 61 poultry, and 51 cattle isolates) in Japan between 2005 and 2006. This approach identified 62 sequence types (STs) and 19 clonal complexes (CCs), including 11 novel STs. These 62 STs were phylogenetically divided into 6 clusters, partially exhibiting host association. We identified a novel ST (ST-4526) that has never been reported in other countries; a phylogenetic analysis showed that ST-4526 and related STs showed distant lineage from the founder ST, ST-21 within CC-21. Comparative genome analysis was performed to investigate which properties could be responsible for the successful dissemination of ST-4526 in Japan. Results revealed that three representative ST-4526 isolates contained a putative island comprising the region from Cj0737 to Cj0744, which differed between the ST-4526 isolates and the reference strain NCTC11168 (ST-43/CC-21). Amino acid sequence alignment analyses showed that two of three ST-4526 isolates expressed 693aa- filamentous hemagglutination domain protein (FHA), while most of other C. jejuni strains whose genome were sequenced exhibited its truncation. Correspondingly, host cell binding of FHA-positive C. jejuni was greater than that of FHA-truncated strains, and exogenous administration of rFHA protein reduced cell adhesion of FHA-positive bacteria. Biochemical assays showed that this putative protein exhibited a dose-dependent binding affinity to heparan sulfate, indicating its adhesin activity. Moreover, ST-4526 showed increased antibiotic-resistance (nalidixic acid and fluoroquinolones) and a reduced ability for DNA uptake. Taken together, our data suggested that these combined features contributed to the clonal thriving of ST-4526 in Japan.

Molecular Typing of Fluoroquinolone-ResistantCampylobacter jejuniIsolated from Broilers in Japan Using Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis

“…In England, Sweden, Switzerland, and New Zealand, CC-21, CC-45, and CC-48 were found to be most prevalent among broiler samples (Griekspoor et al, 2010;Müllner et al, 2010;Wirz et al, 2010), while only one CC-45 strain was isolated in our study. CC-21, CC-45, CC-48, CC-353, and CC-443 were isolated in previous studies conducted in Japan (Yabe et al, 2010;Asakura et al, 2012;Yano et al, 2013). Nevertheless, it is difficult to compare these previous results with those of the present study due to the relatively limited geographical area covered and the lack of information on antimicrobial resistance provided in the previous studies.…”

“…Since then, fluoroquinolones have been approved for use against both avian colibacillosis and avian mycoplasmosis. A significant increase in fluoroquinolone-resistant strains of C. jejuni from broilers was observed in the second stage (2004)(2005)(2006)(2007) Recent studies have reported the molecular typing of C. jejuni from broilers using mainly multilocus sequence typing (MLST) within a limited area of Japan (Yabe et al, 2010;Asakura et al, 2012;Yano et al, 2013). Nonetheless, the epidemiological relationship between fluoroquinoloneresistant C. jejuni strains from broilers is still unclear.…”

Local genes for local bacteria: Evidence of allopatry in the genomes of transatlantic Campylobacter populations

“…In simple attribution models using MLST data, C. jejuni and C. coli isolates from chickens in the Netherlands, Senegal and the United States have been more closely related to UK chicken isolate populations rather than to populations from other host species in the same country (Sheppard, Colles et al., ). While genomic signatures of host association can transcend geographical structuring within C. jejuni and C. coli populations, there can be differences in the genotypes that are isolated from different countries (Asakura et al., ; Islam et al., ; Kivisto et al., ; Mohan et al., ; Prachantasena et al., ). This presents challenges, not only for attributing the source of infections among travellers returning from foreign locations (Mughini‐Gras et al., ), but also for understanding disease epidemiology in the context of a global food industry.…”

“…In C. jejuni, host‐associated clonal complexes can be identified based upon the frequency with which particular genotypes are isolated from different hosts (Sheppard et al., , ). Many of these lineages are globally distributed (Sheppard, Colles et al., ) but despite this strong host signal, there is evidence for phylogeographical structuring and the proliferation of distinct lineages in different countries (Asakura et al., ; McTavish et al., ).…”

Caracterização molecular de linhagens de Campylobacter coli isoladas de origens diversas

“…O MLST possui a vantagem de ser altamente reprodutível além do fato de que seus resultados podem ser disponibilizados em bancos de dados online, o que possibilita a análise comparativa da diversidade genética de bactérias isoladas em diferentes regiões do mundo (Maiden et al, 1998 Campylobacter spp., sendo considerada, atualmente, o método de tipagem "padrão ouro" para esse gênero (Dingle et al, 2001;Schouls et al, 2003;Ragimbeau et al, 2008;Asakura et al, 2012;Duarte et al, 2014). …”