Finnish Campylobacter jejuni Strains of Multilocus Sequence Type ST-22 Complex Have Two Lineages with Different Characteristics

Abstract

Background Campylobacter jejuni is the major cause of human bacterial gastroenteritis worldwide, and in a minority of cases, post-infectious complications may occur. ST-22 complex (usually Penner serotype 19) strains have been overrepresented among patients with postinfectious complications of campylobacteriosis. We here present a characterization of a collection of 27 Finnish C. jejuni strains of ST-22 complex, from humans (22 strains) and animal sources (five strains), with the aim of contributing to our knowledge of the pathogenesis of C. jejuni infections.Methodology/Principal FindingsAll strains were analyzed by pulsed-field gel electrophoresis (PFGE) genotyping, lipo-oligosaccharide (LOS) locus class, Y-glutamyl transpeptidase (GGT) activity, in vitro biofilm formation ability, invasion and adhesion in HeLa cells and induction of IL-8 production. ST-22 complex contained five STs (ST-22; ST-1947; ST-1966; ST-3892; ST-3996) which were homogeneous in having sialylated LOS class A1 but on the other hand were distinguished into two major lineages according to the major STs (ST-22 and ST-1947) by different PFGE genotypes and certain other characteristics. All ST-22 strains had similar SmaI PFGE profiles, were GGT positive, and formed biofilms, except one strain, while ST-1947 strains were all GGT negative, did not form biofilm, had significantly higher motility than ST-22 (p<0.05) and had their SmaI PFGE profile. Invasion and adhesion as well as induction of IL-8 production on HeLa cells were strain-dependent characteristics.Conclusions/SignificanceST-22 complex strains, reveal potential for molecular mimicry in host interactions upon infection as they all express sialylated LOS class A1. The two major STs, ST-22 and ST-1947 formed two homogeneous lineages, which differed from each other both phenotypically and genetically, suggesting that the strains may have evolved separately, perhaps by interacting with different spectra of hosts. Further studies are needed in order to understand if these two lineages are associated with different disease outcomes.

Induction of the NFκ-B signal transduction pathway in response to Corynebacterium diphtheriae infection

“…1a; Ott et al, 2010b). While this cell line is close to the natural situation at least for upper respiratory tract diphtheria, HeLa cells are the most widespread model in host-pathogen interaction studies used for a wide variety of organisms (for recent manuscripts, see Bose et al, 2012;Corbett et al, 2012;Revez et al, 2011) and were therefore tested in this study. In fact, C. diphtheriae was able to bind to this epithelial cell line, and up to 10-fold higher adhesion rates compared with Detroit562 cells were observed (Ott et al, 2010a, b).…”

Characterization of Swedish Campylobacter coli clade 2 and clade 3 water isolates

“…In addition, the earlier characterized clinical C . coli 76339 (Skarp‐de Haan et al., ) and C. jejuni 76577 (Revez et al., ) isolates, and the C. jejuni reference strain NCTC 11168 and the C . coli clade 1 reference strain LMG 6440 were used as experimental controls.…”

“…The isolates were positive for biofilm formation if a stained band was seen at the airliquid interface. The C. coli clade 1 reference strain LMG 6440 was included for comparison, the C. jejuni isolate 76577, previously identified as positive for biofilm formation (Revez et al, 2011), was used as a positive control and broth without addition of bacteria was used as a negative control.…”

“…The majority of clinical and farm animal C. coli isolates belong to the two clade 1 clonal complexes and clade 1 is associated with agricultureadapted C. coli with up to 23% of the genome originating from C. jejuni (Sheppard et al, 2013). Furthermore, whole-genome sequencing can be applied to study the underlying genetic interstrain differences responsible for phenotypical traits as shown for C. jejuni (Lehri et al, 2015;Revez et al, 2011). Thus, combining genomics data with phenotypic observations may lead to a better understanding of the biology of these organisms.…”

“…Biofilms can provide a protective environment and allow for dispersal of the bacteria, improving their chances to survive under harsh conditions. Biofilm studies focused on C. jejuni have shown differences between isolates belonging to different lineages (Asakura et al, 2012;Pascoe et al, 2015;Revez et al, 2011) and Sulaeman et al (2010) showed variation in the ability of C. coli to initiate biofilm formation, which was generally lower than for C. jejuni (Sulaeman et al, 2010).…”