[Epidemiological characteristics of Salmonella in animal source foods in Hunan].
OBJECTIVE
To study the molecular epidemiological characteristics of Salmonella in animal source foods in Hunan.


METHODS
The fair trade markets and supermarkets of ten cities were chosen to sample animal source foods for isolating Salmonella in Hunan province in 2010. A total of 692 samples were collected by aseptic sampling, included 159 livestock meats, 152 poultry meats, and 381 aquatic products.Salmonella strains isolated were subjected to stereotyping, antimicrobial susceptibility testing and pulsed field gel electrophoresis (PFGE).


RESULTS
Salmonella was detected in 93 of 692 animal food samples with the detection rate of 13.4%. The detection rates of Salmonella in poultry meats, livestock meats and aquatic products were 23.0% (35/152), 22.6% (36/159) and 5.8% (22/381) respectively. Therefore, the detection rate in aquatic products was lower than that of poultry meats and livestock meats (χ(2) = 33.86, P < 0.05; χ(2) = 33.29, P < 0.05, respectively). The serotypes of isolates showed diversity, and Salmonella Derby (33/94, 35.1%) was the predominant serotypes.79.8% (75/94) strains showed resistant to more than one antibiotic used in the test, 31.9% (30/94) strains showed resistant to more than 5 antibiotics. A significant difference was observed for multidrug resistance between Salmonella isolated from poultry (47.2%, 17/36) and livestock meats (22.2%, 8/36) (χ(2) = 4.96, P < 0.05). And the highest resistant rate was found in tetracycline, as high as 62.8% (59/94). All the strains were divided into 69 PFGE subtypes.Furthermore the dominating subtypes were type 7 (6 strains), type 15 (4 strains), type 22 (6 strains).


CONCLUSIONS
Inspection results showed that Salmonella contamination in animal source foods were serious in Hunan province, and the isolates expressed high level resistance to the antibiotics.Furthermore the PFGE results indicated that there were epidemic strains of Salmonella in Hunan.
Hunan Provincial Center for Disease Control and Prevention, Key Laboratory of Microbial Molecular Biology of Hunan Province, Changsha 410005, China.
Huayun
H
Jia
Lidong
L
Gao
Yunchang
Y
Guo
Weiwei
W
Li
Lan
L
Wang
Shuai
S
Chen
Email: 931525821@qq.com.
Hong
H
Zhang
D000818:Animals; D000900:Anti-Bacterial Agents; D002681:China / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005516:Food Microbiology; D008460:Meat / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D011200:Poultry / Q000382:microbiology*; D012475:Salmonella / Q000145:classification; D019779:Salmonella enterica; D017747:Seafood / Q000382:microbiology*; D013753:Tetracycline Resistance
D000900:Anti-Bacterial Agents