The prevalence of Shiga toxin-producing Escherichia coli (STEC) in Japan was examined by using stool samples from 87 calves, 88 heifers, and 183 cows on 78 farms. As determined by screening with stx-PCR, the prevalence was 46% in calves, 66% in heifers, and 69% in cows; as determined by nested stx-PCR, the prevalence was 100% in all animal groups. Of the 962 isolates picked by colony stx hybridization, 92 isolates from 54 farms were characterized to determine their O serogroups, virulence factor genes, and antimicrobial resistance. Of these 92 isolates, 74 (80%) could be classified into O serogroups; 50% of these 74 isolates belonged to O serogroups O8, O26, O84, O113, and O116 and 1 isolate belonged to O serogroup O157. Locus of enterocyte effacement genes were detected in 24% of the isolates, and enterohemorrhagic E. coli (EHEC) hlyA genes were detected in 72% of the isolates. Neither the bundle-forming pilus gene nor the enteropathogenic E. coli adherence factor plasmid was found. STEC strains with characteristics typical of isolates from human EHEC infections, which were regarded as potential EHEC strains, were present on 11.5% of the farms.

The aim of this study was to examine the occurrence of bacterial, mycoplasmal and viral pathogens in the lower respiratory tract of calves in all-in all-out calf-rearing units. According to clinical status, non-medicated calves with and without respiratory disease signs were selected of the 40 herds investigated to analyse the micro-organisms present in healthy and diseased calves. Tracheobronchial lavage (TBL) and paired serum samples were analysed for bacteria, mycoplasmas, respiratory syncytial virus (RSV), parainfluenza virus 3 (PIV3), bovine corona virus (BCV) and bovine adenovirus (BAV). Pasteurella multocida was the most common bacterial pathogen. It was isolated from 34% of the TBL samples in 28 herds and was associated with clinical respiratory disease (p < 0.05) when other pathogenic bacteria or mycoplasma were present in the sample. Mannheimia spp. and Histophilus somni were rarely found. Mycoplasma bovis was not detected at all. Ureaplasma diversum was associated with clinical respiratory disease (p < 0.05). TBL samples from healthy or suspect calves were more often negative in bacterial culture than samples from diseased calves (p < 0.05). No viral infections were detected in six herds, while 16-21 herds had RSV, BCV, BAV or PIV3. In the herds that had calves seroconverted to BCV, respiratory shedding of BCV was more frequently observed than faecal shedding. This study showed that the microbial combinations behind BRD were diverse between herds. M. bovis, an emerging pathogen in many countries, was not detected.

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Methods were developed for the polyacrylamide gel electrophoretic analysis of capsular polysaccharides of bacteria with Escherichia coli Kl as a model. Conditions were determined for the rapid and gentle extraction of the Kl polysaccharide by incubation of the bacteria in a volatile buffer and for the subsequent removal of the putative phospholipid moiety attached to the reducing end of the polysaccharide. Detection of the polysaccharides after gel electrophoresis was carried out by fluorography of samples labeled by sodium borotritiide reduction or by combined alcian blue and silver staining. The smaHest components could be detected only by fluorography, owing to diffusion during staining. Components of the E. coli Kl polysialic acid capsule ranging from monomers to 80 sialic-acid-unit-containing polymers could be separated as distinct bands in a ladderlike pattern. A maximum chain length of 160 to 230 sialyl residues was estimated for the bulk of the Kl polysaccharide from the nearly linear reciprocal relationship between the logarithm of the molecular size and the distance of migration. Gel electrophoresis of capsular polysaccharides of other bacterial species revealed different electrophoretic mobilities for each polysaccharide, with a ladderlike pattern displayed by the fastest-moving components. There are many potential applications of this facile method for the determination of the sizes of molecules present in a polydisperse polysaccharide sample. When combined with the simple method for the isolation of the capsule, as in the case of the Kl capsule, it provides an efficient tool for the characterization and comparison of the capsular polysaccharides of bacteria.Capsular polysaccharides are important bacterial surface determinants that consist of polymers with repeating units of one or more monosaccharides (15,16,30). Characterization of bacterial proteins and lipopolysaccharides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis is a commonly applied method in comparative and structural studies. Similar methods have not been available for capsular polysaccharides, and their characterization has therefore been hampered by the need for cumbersome analytical procedures. The chain length of the polysaccharides has been determined with methods like gel filtration, ion-exchange chromatography, determination of the ratio of the terminal and internal residues in the polysaccharide chain, and highperformance liquid chromatography (13,19,20,26,30).One of the most extensively studied capsules is the Escherichia coli Kl capsule, a homopolymer with up to 200 sialic acid residues and ax2-8 linkages (4,21,26). Capsular antibodies and capsule-specific bacteriophages seem to recognize conformational determinants in the polysaccharide chain. In the case of the Kl capsule, mono-and polyclonal anti-Kl antibodies (8, 27) require about eight sialyl residues for binding (6, 7), whereas different Kl-specific bacteriophages containing capsule-degrading endosialidases differ in their minimum substrate size and capsule-...

Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) is a zoonotic pathogen for persons in contact with horses. In horses, S. zooepidemicus is an opportunistic pathogen, but human infections associated with S. zooepidemicus are often severe. Within 6 months in 2011, 3 unrelated cases of severe, disseminated S. zooepidemicus infection occurred in men working with horses in eastern Finland. To clarify the pathogen’s epidemiology, we describe the clinical features of the infection in 3 patients and compare the S. zooepidemicus isolates from the human cases with S. zooepidemicus isolates from horses. The isolates were analyzed by using pulsed-field gel electrophoresis, multilocus sequence typing, and sequencing of the szP gene. Molecular typing methods showed that human and equine isolates were identical or closely related. These results emphasize that S. zooepidemicus transmitted from horses can lead to severe infections in humans. As leisure and professional equine sports continue to grow, this infection should be recognized as an emerging zoonosis.

ABSTRACT. The role of birds as sources of Shiga toxin-and intimin-producing Escherichia coli was studied. Fecal samples from live gulls (n=86), pigeons (n=33) and broiler chickens (n=199) from 23 flocks were analyzed for stx and eae by PCR. No stx positive samples were detected. In contrast, eae E. coli were highly prevalent among gulls (40%), and was also found in pigeons (7%) and chickens (57% of the flocks contaminated). The eae positive isolates were analyzed genetically and O-serogrouped. One isolate from a pigeon was found to have stx 2f . The isolates of gulls differed from those of pigeons and chickens, and all eae E. coli isolates from birds differed from human pathogenic strains by the lack of EHEC-hlyA and bfp/EAF as well as distribution of O-serogroups. Thus, birds cannot be regarded as important carriers of zoonotic stx or eae E. coli in Finland. KEY WORDS: bird, eae, Escherichia coli. J. Vet. Med. Sci. 64(11): 1071-1073, 2002 Enterohemorrhagic Escherichia coli (EHEC), enteropathogenic E. coli (EPEC) and attaching and effacing E. coli (AEEC) are food-borne pathogens that can cause diarrhea in humans [8,10,12]. These pathogenic E. coli often possess genes for Shiga toxins (stxs) and/or for intimin outer membrane protein (eae). Escherichia coli strains with stxs are called Shiga toxin (Stx)-producing Escherichia coli (STEC). Ruminants are considered to be the main reservoir of STECs. Other domestic animals, such as goats, pigs, poultry, cats and dogs can also harbor STECs and intiminproducing E. coli [2,3]. Recently, occurrence of STECs in wild birds was investigated [14,15] and a new Stx2 variant was found in pigeons [14]. However, carriage of STEC or eae possessing E. coli in wild animals has not been thoroughly investigated.Gulls and pigeons inhabit places where human beings live and migrate between waste treatment plants, harbors, marketplaces and cattle pastures, being thus important vehicles for the spread of zoonotic infections. This study was undertaken to analyze the role of wild birds (gulls and pigeons), as well as that of broiler chickens, as reservoirs of Stx-and intimin-producing E. coli. We investigated the prevalence of these E. coli by PCR, and genetically characterized various virulence genes of the isolated strains.Escherichia coli O157:H7 strain ATCC 35150 (American Type Culture Collection, Manassas, Va) was used as a positive control for stxs, eae and intimin type γ (intimin γ). The E. coli strains 166, VR299-2 and EPEC108, used as positive control strains for intimin β, intimin ε, bundleforming pilus (bfp) and "EPEC adherence factor" (EAF) plasmid, were derived from the stock culture collection of the National Veterinary and Food Research Institute, Finland. Cloacal swabs were collected from 86 healthy gulls (Larus ridibundus n=54, and L. argentatus n=32) and 29 healthy pigeons (Culumba palumbus) between June and August 1998. A total of 115 wild birds were caught alive by net for another research purpose, and swab sampling was carried out at the same time of that investigation. ...

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Mycoplasma bovis infections are responsible for substantial economic losses in the cattle industry, have significant welfare effects and increase antibiotic use. The pathogen is often introduced into naive herds through healthy carrier animals. In countries with a low prevalence of M. bovis, transmission from less common sources can be better explored as the pathogen has limited circulation compared to high prevalence populations. In this study, we describe how M. bovis was introduced into two closed and adequately biosecure dairy herds through the use of contaminated semen during artificial insemination (AI), leading to mastitis outbreak in both herds. Epidemiological analysis did not reveal an infection source other than semen. In both farms the primary clinical cases were M. bovis mastitis in cows inseminated with the semen of the same bull four weeks before the onset of the disease. One semen straw derived from the semen tank on the farm and other semen lots of this bull were positive for M. bovis. In contrast, semen samples were negative from other bulls that had been used for insemination in previous or later oestrus to those cows with M. bovis mastitis. Furthermore, cgMLST of M. bovis isolates supported the epidemiological results. To our knowledge this is the first study describing the introduction of M. bovis infection into a naive dairy herd via processed semen. The antibiotics used in semen extenders should be re-evaluated in order to provide farms with M. bovis-free semen or tested M. bovis-free semen should be available.