title: [Surveillance and analysis on the pathogenic features of Salmonella in Guangdong province in 2010].
abstract: 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 surveillant 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 Salmonella isolation and culture. The isolated Salmonella strains were further analyzed via serotyping, antimicrobial susceptibility testing, and PFGE. The χ(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 results 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 (χ(2) = 27.29, P < 0.01). The isolated rates of Salmonella in different regions were as follows: Zhuhai 15.43% (25/162), Maoming 7.53% (18/239), Dongguan 6.51% (39/599), Yangjiang 3.64% (14/385), Zhongshan 3.03% (70/2309), Guangzhou 2.90% (126/4349) and Jiangmen 2.49% (9/362). The difference between regions was statistically significant (χ(2) = 100.75, P < 0.01). Except one strain of the isolated Salmonella cannot be serotyped, the other 300 strains were divided into 42 serotypes, of which Salmonella typhimurium and Salmonella enteritidis were dominant, account for 45.18% (136/301) and 10.96% (33/301) respectively. Although over 85% of Salmonella were sensitive to cephalosporin, ACSSuT resistance patterns (defined as resistance to at least ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline) reached 34.88% (105/301), the highest resistant rate was found 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.
  
  
  CONCLUSIONS
  Salmonella typhimurium and Salmonella enteritidis were the dominant serotypes causing infectious diarrhea in Guangdong province. Cephalosporin was the primary choice in clinical medicine. However, Salmonella typhimurium was resistant to drug most seriously in Guangdong province. There was no significant correlation between Salmonella resistance patterns and PFGE type.
authors.affiliation: Institute of Pathogenic Microorganisms, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 510300, China. gzhdm@21cn.com
authors.forename: Dong-mei
authors.initials: DM
authors.lastname: He
authors.forename: Bi-xia
authors.initials: BX
authors.lastname: Ke
authors.forename: Xiao-ling
authors.initials: XL
authors.lastname: Deng
authors.forename: Chang-wen
authors.initials: CW
authors.lastname: Ke
authors.forename: Zhao-ming
authors.initials: ZM
authors.lastname: Liang
authors.forename: Hai-ling
authors.initials: HL
authors.lastname: Tan
authors.forename: Bo-sheng
authors.initials: BS
authors.lastname: Li
authors.forename: Mei-zhen
authors.initials: MZ
authors.lastname: Liu
authors.forename: Jing-diao
authors.initials: JD
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003967:Diarrhea / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control*; D012477:Salmonella enteritidis / Q000145:classification / Q000302:isolation & purification; D012486:Salmonella typhimurium / Q000145:classification / Q000302:isolation & purification; D012703:Serotyping; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents