Isolation And Identification Of Salmonella In Swine And Chickens Of Partial Areas Of Shaanxi Province And Analysis Of Drug Sensitivity

Salmonella is one of the most serious pathogenic bacteria which is harmful to the development of the animal husbandry. It has a wide spectrum of infections, and can be directly or indirectly spread between people and animals, people and people, animals and animal. Due to improper use of antimicrobials, the drug resistance caused by salmonella is very serious. Thus, the survey to Salmonella infections in farms and the analysis of drug sensitivity can provide important theoretical basis for the rational use of antimicrobials in the farms and for the prevention and treatment of various infectious diseases.200 anus swab samples in pigs and 150 cloaca swab samples in chickens were collected in the farms of Lintong, Tongchuan, Hu county, Tongguan county of Shaanxi province. The color medium was used to isolate and purify the bacteria. The isolated bacteria were identified by biochemical tests, PCR amplification of inc A gene. The results showed that the single colony of aubergine and smooth surface appeared on the chromogenic medium, a single colony with round, colorless, translucent, medium size, smooth surface appeared on nutrient agar medium. The biochemical test result confirmed the characteristics of Salmonella.The amplification of Salmonella inc A gene by PCR showed a target fragment about 284 bp.38 strains of Salmonella were isolated from 200 samples collected from pigs, the isolation rate is 19%; 21 strains of Salmonella were isolated from 150 samples collected from chickens,the isolation rate is 14%.The slide agglutination tests were used to identified the 38 Salmonella strains from pigs and 21 strains from chickens, respectively, by Salmonella diagnosis serum kit. The results showed that 38 pig Salmonella strains distribute in B and C1 groups, two strains, S. derby10.53%(4/38) and S. typhimurium34.21% are in group B, and one strain S. risen 55.26%(21/38) is in group C1. 21 chicken Salmonella strains distribute in B and D groups, two strains, S. derby 19.05%(4/21) and S. typhimurium(7/21) are in group B, and two strains, S.gallinarum 23.81%(5/21) and S. pullbrum23.81%(5/21) are in group D. S. rissen and S.typhimurium are predominant species.The sensitivity test of 13 kinds of antimicrobial agents was made by using the freeze dried bacteria quantitative drug sensitivity(MIC) test kit. The results showed that 38 Salmonella strains from pigs are most sensitive to CEF, with a 100% sensitive rate, thesensitive rate to CL is 97.37%, to A/C is 89.47%, to GM and ENR are 86.84%, to OFL is84.21%, to FFC is 60.53%, to AM and SXT are 34.21%, and the 38 strains are total resistant to DOX, TE and SF, with 100% drug resistance. 21 Salmonella strains from chickens are most sensitive to CEF and CL, with a 95.24% sensitive rate, the sensitive rate to OFL is76.19%, to GM is 71.43%, to SXT is 52.38%, to A/C is 47.62%, to FFC is 42.86%, to ENR is33.33%, to DOX is 28.57%, to TE is 23.81%, and the resistance rate of 21 strains of chicken Salmonella to SF is 95.24%, to AM is 90.48%.