Different types of fimbriae were reported to be associated with STEC diarrhea in animals of different age groups [15–18]. The Yersinia high-pathogenicity island (HPI) carrying fyuA (find more encoding the pesticin receptor) and irp (encoding the siderophore yersiniabactin) is also present in certain non-O157 STEC lineages and was previously reported only in stx 2e carrying human isolates [19]. Domestic ruminants, especially cattle, are the major
reservoirs of STEC. Other animals like sheep, goats have been confirmed as important natural reservoirs in some countries [2, 20–22]. Swine also play an important role as a carrier of this pathogen. STEC strains that produce Stx2e can cause edema disease in pigs [23] and can also been isolated from human stools at low frequency. STEC carried by healthy pigs may pose a potential risk to humans [24–27]. Relatively little is known about the prevalence and characteristics of STEC in pigs
in China. In this GDC 0032 mw study, we isolated and characterized STEC from different pig slaughter houses and pig farms from 3 geographical regions, Beijing city, Chongqing city and Guizhou province in China. Results Prevalence of STEC in swine samples Out of 1003 swine samples collected in this study, 25.42% (255/1003) were stx-positive by PCR. A total of 93 STEC isolates was obtained from 62 samples, giving a culture positive rate of 24.31% (62/255) of all stx-positive Epacadostat in vivo samples. Different stx-positive rates in small intestine contents (10.83%), colon contents (47.24%) and feces (19.33%) samples were Y-27632 2HCl observed. The colon contents samples gave the highest stx-positive rate (P < 0.05) and also the highest culture positive rate (18.09%) (P < 0.05) (Table 1). Table 1 Prevalence of STEC in swine samples Sample location (city/province)
No. of samples Type of samples (N, %) stx positive samples (N, %) Samples with STEC isolates (N, %) STEC isolates (N, %) Beijing 523 SC (248, 24.73) SC (30, 8.55) SC (3, 0.85) SC (7, 1.99) CC (275, 27.42) CC (139, 42.64) CC (36, 11.04) CC (57, 17.48) Chongqing 326 F (326, 32.50) F (63, 19.33) F (17, 5.21) F (23, 7.06) Guizhou 154 SC (103, 10.27) SC (8, 2.28) SC (4, 1.14) SC (4, 1.14) CC (51, 5.08) CC (15, 4.60) CC (2, 0.61) CC (2, 0.61) Total 1003 SC (351, 35.00) SC (38, 10.83) SC (7, 1.99) SC (11, 3.13) CC (326, 32.50) CC (154, 47.24) CC (38, 11.66) CC (59, 18.09) F (326, 32.50) F (63, 19.33) F (17, 5.21) F (23, 7.06) Sample codes: F, fecal samples; CC, colon contents samples; SC, small intestine contents samples. The number (N) and rate (%) are showed in the parentheses. Only a single isolate was recovered from 44 stx-positive samples each. But 2 isolates per sample were recovered from 15 samples, 3 isolates per sample from 3 samples, 4 isolates per sample from 2 samples and 5 isolates per sample from 1 sample. Serogroups and serotypes The 93 STEC isolates were typed into 19 serotypes, comprising 12 O serogroups and 15 H types.