Isolation and Characteristics of Shiga Toxin 2f-Producing Escherichia coli among Pigeons in Kyushu, Japan

Abstract

An increasing number of Shiga toxin 2f-producing Escherichia coli (STEC2f) infections in humans are being reported in Europe, and pigeons have been suggested as a reservoir for the pathogen. In Japan, there is very little information regarding carriage of STEC2f by pigeons, prompting the need for further investigation. We collected 549 samples of pigeon droppings from 14 locations in Kyushu, Japan, to isolate STEC2f and to investigate characteristics of the isolates. Shiga toxin stx 2f gene fragments were detected by PCR in 16 (2.9%) of the 549 dropping samples across four of the 14 locations. We obtained 23 STEC2f-isolates from seven of the original samples and from three pigeon dropping samples collected in an additional sampling experiment (from a total of seven locations across both sampling periods). Genotypic and phenotypic characteristics were then examined for selected isolates from each of 10 samples with pulsed-field gel electrophoresis profiles. Eight of the stx 2f gene fragments sequenced in this study were homologous to others that were identified in Europe. Some isolates also contained virulence-related genes, including lpfA O26, irp 2, and fyuA, and all of the 10 selected isolates maintained the eae, astA, and cdt genes. Moreover, five of the 10 selected isolates contained sfpA, a gene that is restricted to Shiga toxin-producing E. coli O165:H2 and sorbitol-fermenting Shiga toxin-producing E. coli O157:NM. We document serotypes O152:HNM, O128:HNM, and O145:H34 as STEC2f, which agrees with previous studies on pigeons and humans. Interestingly, O119:H21 was newly described as STEC2f. O145:H34, with sequence type 722, was described in a German study in humans and was also isolated in the current study. These results revealed that Japanese zoonotic STEC2f strains harboring several virulence-related factors may be of the same clonal complexes as some European strains. These findings provide useful information for public health-related disease management strategies in Japan.

Whole-Genome Characterization and Strain Comparison of VT2f-ProducingEscherichiacoliCausing Hemolytic Uremic Syndrome

“…VT2f-producing E. coli strains isolated from uncomplicated human cases of diarrhea have been reported in the literature as being ST20 ( 11 ), which is the same sequence type we identified in most pigeon isolates; this ST was also described in VT2f-producing E. coli isolated from pigeons in Japan ( 40 ). The same study also described an animal isolate of ST722, which was found in 1 strain isolated from human diarrheal feces in our study (Table 2).…”

“…All VT2f strains from HUS that we examined were positive for pathogenicity island OI-122 ( 28 ) and the large virulence plasmid first described in VTEC O157 (Table 2) ( 39 ); the strains from pigeons or from humans with uncomplicated diarrhea did not have these virulence-associated mobile genetic elements (Table 2) ( 10 – 12 , 32 , 40 ). …”

Escherichia coli H-Genotyping PCR: a Complete and Practical Platform for Molecular H Typing

“…Most STEC outbreaks and sporadic cases have been attributed to O157:H7, O26:H11, O111:H8, O45:H2, O103:H2, O145:H28, and O121:H19 (or the nonmotile isolates) (14,(19)(20)(21)(22)(23)(24)(25). Additionally, other STEC serotypes, such as O6:H10, O91:H10/H14/H21, O103: H11/H25, O111:H11/H21, O145:H25/H34, O165:H25, and O178:H19, from foods, animals, and humans, have also been reported (14,22,(24)(25)(26)(27)(28)(29)(30)(31). Two multiplex PCR kits developed in this study, MP-A and MP-B, are particularly useful for distinguishing these H types.…”

A scoping review on the prevalence of Shiga‐toxigenic Escherichia coli in wild animal species

“…Previous studies investigated the prevalence of STEC among urban exploiter species such as rats (Himsworth et al, ) or pigeons (Gargiulo et al, ; Kobayashi, Pohjanvirta, & Pelkonen, ; Murakami et al, ; Silva, Nicoli, Nascimento, & Diniz, ). Likewise, other wild animal species have been investigated such as deer (Asakura et al, ; Carrillo‐Del Valle et al, ; Dunn, Keen, Moreland, & Alex, ) and gulls (Makino et al, ).…”