2010年广东省沙门菌监测及其病原学特征分析

Surveillance and analysis on the pathogenic features of Salmonella in Guangdong province in 2010

目的了解广东省腹泻患者沙门菌感染情况，分析沙门菌菌株的血清型分布、耐药性和分子特征。方法2010年对广东省广州、中山、东莞、珠海、茂名、阳江和江门等地的16家哨点医院的8405例腹泻患者进行了沙门菌监测，收集到8405份粪便标本，进行分离培养。对分离到的沙门菌进行血清分型、药物敏感试验和PFGE分子分型。应用x。检验分析不同季节、不同地区沙门菌分离情况的差异；应用BioNumerics软件对电泳图谱进行分析，确定菌株问的相关性。结果2010年广东省沙门菌监测阳性率为3．58％（301／8405），男女之比为1．34：1（166／124）；各年龄段均可感染沙门菌，以婴儿为主，占57．48％（173／301）。春、夏、秋、冬各季节沙门菌的分离率分别为3．48％（61／1751）、4．97％（134／2695）、3．08％（73／2370）、2．08％（33／1589），不同季节间比较，差异有统计学意义（X^2=27．29，P〈0.01）。不同地区沙门菌分离率分别为：珠海15．43％（25／162）、茂名7．53％（18／239）、东莞6．51％（39／599）、阳江3．64％（14／385）、中山3．03％（70／2309）、广州2．90％（126／4349）、汀门2．49％（9／362），地区之间比较，差异有统计学意义（X^2=100．75，P〈0．01）。除1株沙门菌末能分型外，其余300株菌分为42种血清型，以鼠伤寒沙门菌和肠炎沙门菌为主，分别占45．18％（136／301）和10．96％（33／301）。沙门菌虽然对头孢类抗菌药物敏感率达85％以上，但卅现ACSSuT耐药谱（埘氨苄两林、氯霉素、链霉素、磺胺甲二唑和四环素多重耐药）总耐药率达34．88％（105／301），而鼠伤寒沙门菌总耐药率更高，达65．44％（89／136）。136株鼠伤寒沙门菌分成51个PFGE型，表现出较大的遗传多样性。33株肠炎沙门菌分成18个PFGE型。PFGE图谱相同者可有不同的耐药谱，反之亦然。结论在广东省引起感染性腹泻的沙门菌主要为鼠伤寒沙门菌和肠炎沙门菌。鼠伤寒沙门菌是广东省耐药最严重的血清型。沙门菌耐药谱和PFGE图谱无明显关联。

[ Objective In order to better understand the nature of Salmonella infection in diarrheal patients in Guangdong province, the study analyzed the serum types, antibiotic resistance and molecular determinants of the isolated Salmonella strains. Methods In year 2010, 8405 diarrhea patients from 16 smveillant hospital in Guangzhou, Zhongshan, Dongguan, Zhuhai, Maoming, Yangjiang and Jiangmen cities in Guangdong province, were recruited in the study. A total of 8405 fecal specimen were collected and subjected to SalmoneUa isolation and culture. The isolated Salmonella strains were further analyzed via serotyping, antimicrobial susceptibility testing, and PFGE. The X^2 test was applied to compare the differences between the isolated Salmonella strains in different seasons and districts. BioNumerics software was used to analyze the PFGE resuhs in order to determine the correlation between different Salmonella strains. Results The positive rate of the surveillant Salmonella in Guangdong province was 3.58% （301/8405） in 2010; with the gender ratio at 1.34：1 （166/124）. Salmonella infection was found in all age groups, and most in infants, accounting for 57.48% （ 173/301 ） . The isolated rates of Salmonella were separately 3.48% （61/1751）, 4.97% （ 134/2695）, 3.08% （73/2370） and 2. 08% （33/1589） in the four seasons; and the difference was statistically significant （ X^2 = 27.29, P 〈 0. 01 ）. The isolated rates of Salmonella indifferent regions were as fifllows： Zhuhai 15.43% （ 25/162 ） , Maoming 7.53% （18/239） , Dongguan 6. 51% （39/599） , Yang.jiang 3.64% （ 14/385 ） , Zhongshan 3.03% （70/2309） , Guangzhou 2.90% （ 126/4349 ） and Jiangmen 2.49% （9/362）. The dift）renee between regions was statistically significant （ X^2 = 100. 75, P 〈 0. 01 ） . Except one strain of tile isolated Salmonella eannot be serotyped, the other 300 strains were divided into 42 serntypes, of which Sahnonella typhimurium aud S（dmonella enteritidis were dominant, account for 45. 18% （ 136/301 ） and 10. 96% （ 33/301 ） respectively. Ahhnugh over 85% of Salmonella were sensitive to eephalospnrin, ACSSuT resistance patterns （ defined as resistance to at least arnpicillin, ehloramphenicol, streptomycin, sultamethoxazole and tetracycline） reached 34. 88% （105/ 301 ） , the highest resistant rate was tound in serotype Salmonella typhimurium, as high as 65.44% （89/ 136）. 136 strains of Salmonella typhimurium were divided into 51 PFGE types, showed great genetic diversity. 33 strains of Salmonella enteritidis were divided into 18 PFGE types. The strains with same PFGE pattern may have different drug-resistant patterns, and vice versa. Conclusion Salmonella typhimurium and Salmonella enteritidis were the dominant serntypes causing infectinus diarrhea in Guangdong province. Cephalosporin was the primary ehniee in elinical medicine. However, Sahnonella typhimurium was resistant to drug most seriously in Guangdong province. There was no significant eorrelation between Salmonella resistance patterns and PFGE type.