Characterization of unstable pEntYN10 from enterotoxigenicEscherichia coli(ETEC) O169:H41

Abstract

Nishikawa (2015) Characterization of unstable pEntYN10 from enterotoxigenic Escherichiacoli (ETEC) O169:H41, Virulence, 6:8, 735-744, DOI: 10.1080/21505594.2015 Keywords: cell adhesion, Escherichia coli, ETEC, genetic diversity, plasmidEnterotoxigenic Escherichia coli (ETEC) serotype O169:H41 has been an extremely destructive epidemic ETEC type worldwide. The strain harbors a large unstable plasmid that is regarded as responsible for its virulence, although its etiology has remained unknown. To examine its genetic background specifically on the unstable retention and responsibility in the unique adherence to epithelial cells and enterotoxin production, the complete sequence of a plasmid, pEntYN10, purified from the serotype strain was determined. The length is 145,082 bp; its GC content is 46.15%. It contains 182 CDSs, which include 3 colonization factors (CFs), an enterotoxin, and large number of insertion sequences. The repertory of plasmid stability genes was extraordinarily scant. Uniquely, results showed that 3 CFs, CS6, CS8 (CFA/III)-like, and K88 (F4)-like were encoded redundantly in the plasmid with unique variations among previously known subtypes. These three CFs preserved their respective gene structures similarly to those of other ETEC strains reported previously with unique sequence variations respectively. It is particularly interesting that the K88-like gene cluster of pEntYN10 had 2 paralogous copies of faeG, which encodes the major component of fimbrial structure. It remains to be verified how the unique variations found in the CFs respectively affect the affinity to infected cells, host range, and virulence of the ETEC strain.

pEntYN10 a plasmid of Escherichia coli O169:H41 associated with adherence and toxin production

“…Although these observations are in keeping with those reported by Ban et al. 1 more studies are required to define the participation of the plasmids in the expression properties of E . coli O169:H41 wild strains as they relate to the bacteria's virulence.…”

“…Ban et al. 1 described the complete sequence results of the pEntYN10 plasmid of Escherichia coli O169:H41, which was isolated from an epidemic outbreak of diarrhea in Osaka, Japan in 1991. Since then, other outbreaks have been reported in different countries including the Republic of Korea, 2 Japan 3 and the USA.…”

“…9 Ban et al. 1 describe the complete sequence of the pEntYN10 plasmid identified in the E . coli O169:H41 strain.…”

Comparative genomic analysis and molecular examination of the diversity of enterotoxigenic Escherichia coli isolates from Chile

“…Interestingly, the three phylogroup A isolates selected for complete genome sequencing were very closely related based on the phylogeny (Fig 1), and each isolate has the same plasmid profile, and a very similar virulence factor profile (Table 1). While the early studies of ETEC plasmid diversity indicated that the plasmid content was extremely variable [13, 14, 60, 61, 67, 71], more studies [31], including the current study indicate the presence of stable combinations of ETEC chromosome and plasmids. The reasons for the stability of these combinations and instability of other chromosome:plasmid combinations is not clear and will require further functional analyses to examine in detail.…”

Prevalence of Diarrheagenic <i>Escherichia coli</i> in Foods and Fecal Specimens Obtained from Cattle, Pigs, Chickens, Asymptomatic Carriers, and Patients in Osaka and Hyogo, Japan

“…The variants that possessed est and or elt that were detected by our multiplex PCR assay might be porcine pathogens. However, Ban et al recently found that the ETEC O169:H41 strain possesses genes encoding proteins homologous to the colonization factor K88 found in pig ETEC (38). Since ETEC O169:H41 is an emerging DEC in both Japan and the United States (13,39), ETEC originating from pigs may be transmitted to humans via meat and foods, just as STEC carried by cattle is transmitted via beef products and water polluted by feces.…”