The prevalence and characteristics of eae-and stx-positive Escherichia coli strains in wild birds in the immediate environment of Tokyo Bay, Japan, was examined using cloacal swab samples taken from 447 birds belonging to 62 species. PCR screening showed that the prevalences of stx-and eae-positive strains of Escherichia coli were 5% (23/447) and 25% (113/447), respectively. Four strains of stx 2f -positive E. coli were isolated from two feral pigeons, an oriental turtle dove and a barn swallow. In contrast, 39 eae-positive E. coli strains were isolated, and most of the strains possessed a subtype of intimin that is classified as a minor group of human intimins, such as intimin , , and . Moreover, these strains did not possess any of the other pathogenic genes tested, such as stxs, ehxA, bfp, or irp. Thus, wild birds were considered to be a reservoir of atypical enteropathogenic E. coli.Pathogenic Escherichia coli, such as enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), and attaching and effacing E. coli, are food-borne pathogens that cause diarrhea in humans (13,16,20). The pathogenicity of these E. coli strains is, in large part, due to the fact that they express genes for Shiga toxins (stx genes) and/or for intimin, a virulence factor that is an outer membrane protein (eae). Ruminants are considered to be the main reservoir of Stx-producing E. coli (STEC). However, other domestic animals such as goats, pigs, poultry, cats, and dogs can also harbor STEC, in addition to intimin-producing E. coli (3,4). A recent investigation of the occurrence of STEC in wild birds (14,18,22,24) indicated that the latest stx 2 variant (stx 2f ) is found in pigeons (22); however, the carriage of stx-or eae-possessing E. coli strains in wild animals has not been thoroughly investigated. Some wild birds live in human habitats and others migrate between waste treatment plants, marketplaces, cattle pastures, and pig farms. Such interactions between humans and wild birds therefore make birds important vehicles for the spread of zoonotic infections.The goal of the present study was to analyze the role of wild birds as reservoirs of stx-and intimin-producing strains of E. coli. The prevalence of these E. coli strains in wild birds was examined using PCR analysis, and further genetic characterization of the various virulence genes of the isolated strains was performed.The E. coli strain O157:H7, used as a positive-control strain for analysis of the stx 1 , stx 2 , and eae genes by PCR, was obtained from the American Type Culture Collection (ATCC 35150). The E. coli strains Ch05031 and PGN28, used as positive-control strains in PCR analyses of the stx 2e and stx 2f genes, respectively, were derived from the stock culture collection of the National Institute of Animal Health, Japan. A total of 447 cloacal swab samples were collected from 62 species of wild birds that had been captured between 2003 and 2007 (Table 1). The birds were captured for various reasons, such as falling from nests or as a consequence of being hunt...

ABSTRACT. A total of 328 cloacal swabs and 163 footpads of wild birds were investigated for the presence of salmonellae. All 19 isolates from cloacal swabs were serotyped as Salmonella Typhimurium susceptible to all five conventional antimicrobial agents (ampicillin, chloramphenicol, streptomycin, oxytetracycline and nalidixic acid) tested. In contrast, 15 salmonellae isolated from footpads included S. Muenhen, S. Virchow, S. Bareily and S. Bovismorbificans, including S. Typhimurium; these non-Salmonella Typhimurium isolates showed multiple drug resistance. KEY WORDS: Salmonella, wild bird.

ABSTRACT. The prevalence of STEC in Japan was examined using rectal stool samples taken from 932 healthy dairy cows from 123 farms in 11 prefectures between 2006 and 2007. Screening with stx-PCRs revealed the prevalence to be 30.4% (283 animals), and STEC strains were isolated from 111 animals. Although ten O-serogroups (O8, O22, O84, O103, O111, O113, O116, O136, O153 and O157) were the major O-serogroup in healthy dairy cows in Japan in 1998, half of the 118 selected STEC strains were serotyped as O2, O8, O26, O153, or O163 in this study. Twenty-eight of the 118 STEC strains (24%) showed resistance to some conventional drugs, such as dihydrostreptomycin, oxytetracycline and aminobenzylpenicillin. Although STEC prevalence in cows decreased from 17% to 12%, the antimicrobial resistance ratio increased from 8.7% to 24% in the past decade in Japan. KEY WORDS: healthy dairy cow, O-serogroup, STEC.J. Vet. Med. Sci. 71(3): 363-366, 2009 The importance of Shiga toxin (Stx)-producing Escherichia coli (STEC) has increased since a food-borne infection caused by enterohemorrhagic E. coli (EHEC) was first described [13]. Cattle have been implicated as a principle reservoir of STEC [3,4,16]. The STEC strains are classified into a large number of O-serogroups [2,12]. Although, the potential of these STEC isolates to cause human disease is unclear [7], gaining knowledge of the prevalence and characteristics of STEC strains in cattle is crucial for analyzing the influence on human health. We previously described the prevalence of STEC in healthy cattle in Japan and genetically characterized various virulence genes of the STEC strains isolated in 1998 [8]. Since that investigation, ten years have passed. The aims of the present study were to show how the prevalence of O-serogroups and antimicrobial susceptibility of STEC in healthy dairy cows have changed over the past decade.Escherichia coli O157:H7 strain ATCC 35150, used as a positive control strain for both stxs and eae genes which encode Stx and bacterial outer membrane protein, respectively, was obtained from the American Type Culture Collection. Escherichia coli Ch05031 and PGN28, used as positive control strains for the stx2e and stx2f genes, respectively, were derived from the stock culture collection of the National Institute of Animal Health.A total of 932 rectal stool grab samples were collected from healthy dairy cows on 123 farms in 11 prefectures located in various regions of Japan between May 2006 and November 2007. All rectal stools were sampled by veterinarians from governmental animal hygiene centers. The samples were placed in a cool room (4 to 8°C) and taken to the laboratory for immediate processing (usually within 24 hr). Samples that could not immediately be taken to the laboratory for processing were frozen at below -20°C until being mailed to us. Each sample of one gram of stool sample was enriched in 19 ml of modified E. coli broth (mEC) (Eiken, Tokyo, Japan) at 37°C for 16 to 18 hr. Ten microliters of the Trypticase soy broth culture was inoculate...