title: [Investigation of enterotoxin gene in clinical isolates of Staphylococcus aureus].
abstract: OBJECTIVE
  To detect the enterotoxin genes of Staphylococcus aureus (SA) isolated from clinical specimens and analyze the correlation between enterotoxin genes and drug resistance of SA.
  
  
  METHODS
  The mecA gene and enterotoxin genes A-F of clinical SA isolates were identified by polymerase chain reaction (PCR), and the genes were sequenced to investigate the correlation of these genes to drug resistance.
  
  
  RESULTS
  The detection rate of enterotoxin genes was 100% in 67 methicillin- resistant SA (MRSA), showing no significant difference from the rate in 57 methicillin-sensitive SA (MSSA) (83.5%, χ(2)=0.203, P>0.05). Of the 116 strains carrying enterotoxin genes (93.5%), the detection rates of SEA, SEB, SEC, SED and SEF were 90.5%, 6.9%, 61.3%, 5.2%, 25.9% and 93.5%, respectively, and none of the strains were positive for SEE gene. In these strains, 78 (67.2%) carried 2 or more enterotoxin genes, and the main genotypes were SEA and SEC (33.6%), SEA and SEF (7.8%), and SEA and SEC and SEF (13.8%). Compared with the strains carrying a single enterotoxin gene, those with multiple enterotoxin genes showed a higher drug resistance rate, among which 75% of the SA strains carrying SEA+SEC+SEF were resistant to SXT, significantly higher than the rates of SA carrying SEA (28.6%) and SEA+SEC (38.7%) (P<0.05). The SA strains carrying SEA+SEC+SEF and SEA+SEF showed significantly higher amikacin resistance rates than SA strain carrying SEA (75.0%, 77.0%, 21.5%, respectively, P<0.05).
  
  
  CONCLUSIONS
  Clinical isolates of SA carrying multiple enterotoxin genes have a higher drug resistance rate than those with a single enterotoxin gene, suggesting the the important role of enterotoxin in multidrug resistance.
authors.affiliation: Department of Clinical Laboratory, Central South University, Changsha, China. caohong02917@163.com
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Zheng
authors.forename: Xianping
authors.initials: X
authors.lastname: Li
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Yunsheng
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yifen
authors.initials: Y
authors.lastname: Yang
mesh_terms: D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004768:Enterotoxins / Q000235:genetics*; D006801:Humans; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*
chemical_list: D004768:Enterotoxins