Strain Sw-9 initially identified
as CTEC-II O84:NM by biochemical test was re-identified as E. albertii, a newly emerging diarrheagenic pathogen , by a MLS analysis and sugar utilization tests. This may be the first report showing isolation of E. albertii from swine in Japan. Furthermore, this finding prompted us to reinvestigate if previously identified CTEC-II strains were of E. albertii or not. Indeed the CTEC-II strain AH-5, previously identified as OUT:NM , was found to be E. albertii (Figure 2). Ooka et al.  recently reported that 26 out of 179 eaeA gene-positive E. coli strains, isolated from humans, birds and the environment in Japan, were identified as E. albertii by MLS analysis and cdtB gene www.selleckchem.com/products/sbi-0206965.html of CDT-II/III/V subtypes group was detected by PCR in all the E. albertii strains except 1 strain. EPEC isolates, previously identified as E. coli O86:K61 and contained the cdtB gene, Selleckchem Ferrostatin-1 were also identified as E. albertii. The cdt genes of E. albertii strain 19982 (GenBank: AY696755) are highly homologous to the cdt-II genes present in E. coli strains. These data suggest that E. albertii might have been misidentified as not only EPEC but also CTEC-II. Since there is no reliable
method to identify E. albertii other than MLS analysis to date, the development of simple and reliable identification method of E. albertii is required. The cdt-II genes could be one of useful genetic markers for this purpose although discrimination of E. albertii from true CTEC-II is still necessary. Conclusions
We could isolate a number of CTEC strains from cattle and swine, which had PF-01367338 price diverse variations in serotype and genotype. Some of the CTEC strains possessed virulence genes associated with human over diseases and serotype that are frequently detected among human clinical strains. Thus, cattle and swine could be possible reservoirs of CTEC and serve as potential sources of infection to human. To the best of our knowledge, this might be the first report regarding comprehensive surveillance and characterization of CTEC strains isolated from healthy food animals. Because of the limited number of animals and farms examined, further studies are of course needed to verify the probability that these animals are indeed the source of CTEC infection to humans. Methods Sample collection In August 2004 in Japan, stool specimens from the rectum of 102 cattle (around 1 year of age), including 95 cross breeding cattle (from Bv-1 to Bv-95) and 7 Holstein cow (Bv-96 to Bv-102), and rectal swabs from 45 cross breeding swine (<6 month-old) and 45 broiler chickens (<1 year-old) were collected in Nara, Japan. The cattle were kept in several barns in a farm, the swine in several pens in a barn, and the chickens in a windowless broiler house. All the animals were healthy and asymptomatic. The samples were transported to the laboratory at ambient temperature and processed within 6 h of collection.