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Summary : 1,890 cattle fecal, water, milk and feeds samples were routinely collected from seven dairy cattle farms at different localities of Kagoshima prefecture, southern Japan during a period from January 2005 to December 2009. The samples were examineThe obtained results were summarized as follows:1- Examination of 1890 samples collected from investigated dairy cattle herds revealed that S. enterica was recovered from 38 samples with overall prevalence 2.0 %. Besides, the isolated Salmonella serovars were S. Typhimurium, Stanley, Enteritidis, MuencRegarding, S. enterica serovars in cattle herds in relation to investigated farms, it was found that the prevalence of Salmonella isolates in all investigated farms were nearly similar with a lower prevalence ranged from 0.4 – 1.9%, except farm 3 in which2- Investigation of 1680 fecal samples collected from cattle of different ages showed that S. enterica was isolated from 38 samples with prevalence 2.3% and the most common serotype of Salmonella isolated was S. Typhimurium followed by S. Stanley and S. EThe percentages of isolated S. enterica in faeces of dairy cows, heifers, calves and fattening steers were 2.7, 0.6, 3.1 and 0%, respectively.Comparison of S. enterica isolates in faeces of different cattle groups revealed comparatively higher percentage in calves rather than other cattle groups.Seasonal investigations of S. enterica isolates from all examined fecal samples in different seasons clarified that the highest percentage was recorded in winter season.3- Prevalence of S. enterica serovars in dairy cattle herd fecal samples with relation to the total isolated Salmonella number revealed that Salmonella was isolated in 38 (2.3%) out of 1680 dairy cattle fecal samples during 2005-2009. Out of these isolate4- Examination of S. enterica serovars in drinking water, milk and feed samples collected from dairy cattle farms during the study period revealed no evidence of Salmonella.5- Salmonella genomic island 1 PCR results showed the expected sizes of approximately 500 and 515 bp for both the left and right SGI1junctions in most of S. enterica serovar typhimurium isolates (12 out of 19 isolates). While, other S. enterica isolates [6- Analysed the presence of some virulence genes amongst Salmonella isolates showed that all isolated S. enterica serovars possessed the invasion gene (invA).Concerning the occurrence of Salmonella plasmid virulence gene (spvC), 14 out of 19 S. Typhimurium isolates were positive yielded the expected size PCR amplification product. However, PCR results were negative for spvC gene in other S. enterica serovar TyExamination of S. enterica serovars for the detection of plasmid-encoded fimbriae (pefA) gene revealed that 13 isolates belonged to S. enterica serovar Typhimurium out of the total recovered isolates were positive for the pefA gene.Regarding PCR amplification of rck (resistance to complement killing) gene in isolated serovars showed that out of 19 S. enterica serovar Typhimurium isolates, 11 isolates were positive for the rck gene.7- The majority of Salmonella isolates were resistant to the most of the tested antimicrobials, resistance was frequently observed to streptomycin, sulfamethoxazole and oxytetracycline (78.9%, each), followed by ampicillin, chloramphenicol and kanamycin i8- On the basis of antibiotic susceptibility, Three R-types commonly observed among MDR Salmonella isolates were AMP, CHL, STR, TET, SUL+; AMP, CHL, STR, TET, SUL; and STR, TET, SUL. Furthermore, serovars Enteritidis, Thompson, Agona and Muenchen were ful9- The results of antimicrobial resistance determinants and class 1 integrons amongst MDR Salmonella isolates showed that the Serotype Typhimurium had class 1 integrons comprising variable regions with size ranging from 1.0 kb to 1.5 kb carried blaPSE-1, 10- The nucleotide sequence analysis of the obtained amplicons carried by the representative MDR S. Stanley isolates revealed the integration of two gene cassettes: aadA1 and dfrA12.11- The DNA fingerprints of S. Typhimurium isolates by PFGE revealed four distinct patterns. Also, analysis of the PFGE profiles showed a significant genetic variation between DT104 and non-DT104 isolates of S. Typhimurium.Regarding analysis of DNA fingerprints of S. enterica serovar Stanley isolates revealed two cluster groups responsible for the dissemination of resistance amongst cattle in the study area. Isolates in each cluster shared 100% similarity, whereas, the two XbaI-generated DNA fingerprints of S. enterica serovar Enteritidis classified the isolates into two groups. The first group consisted of three isolates shared 100% similarity, which designated as the common pattern.12- Multi-drug resistance profiles and DNA fingerprinting results indicated that Twelve out of nineteen (63.1%) isolates of S. typhimurium were S. Typhimurium phage type DT104 as they showed the typical penta-resistance pattern of S. Typhimurium phage typ13- Analysis of the plasmids carried by MDR Salmonella isolates clarified that S. Typhimurium isolates carried plasmids of variable sizes ranging from 3.5-100 kb. Moreover, MDR S. Stanley isolates harboured easily transferable plasmids of ca. 210 kb with
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