title: Accessory gene regulator group polymorphisms in methicillin-resistant Staphylococcus aureus: an association with clinical significance.
abstract: OBJECTIVE
  Virulent gene expression in Staphylococcus aureus is controlled by regulators such as the accessory gene regulator (agr). Strains can be divided into four major agr groups (agr I-IV) on the basis of agrD and agrC polymorphisms. The purpose of this study was to define the proportion of agr I, II, and III polymorphisms and to compare the clinical characteristics between group I and non-group I polymorphisms of methicillin-resistant Staphylococcus aureus (MRSA) strains in a Korean tertiary care teaching hospital.
  
  
  METHODS
  A total of 158 clinical isolates were evaluated by RFLPs (restriction fragment length polymorphisms).
  
  
  RESULTS
  The mean age of the patients was 50.2 +/- 21.9 years old. There were 74 (49.3%), 66 (44.0%), 10 (6.7%), 7 (4.4%), and 1 (0.6%) strains in agr group I, II, III, I + II, and I + III polymorphisms, respectively. Only ear infections were a statistically significant clinical parameter according to univariate (p=0.001) and multivariate analysis (OR, 4.721 (1.273-17.508), p=0.020).
  
  
  CONCLUSIONS
  This study suggests that agr group I is the most prevalent in Korea, and ear infections are correlated with the group I polymorphism, which is a different clinical trend from western countries. It can also be inferred that community-acquired MRSA correlates with agr group I.
authors.affiliation: Department of Internal Medicine, Yongdong Severance Hospital, Yonsei University College of Medicine, 146-92 Dogok-Dong, Kangnam-Gu, Seoul, Korea.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Choi
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Lee
authors.forename: Dongeun
authors.initials: D
authors.lastname: Yong
authors.forename: June Myung
authors.initials: JM
authors.lastname: Kim
authors.forename: Young Goo
authors.initials: YG
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D001426:Bacterial Proteins / Q000235:genetics; D015897:Comorbidity; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008297:Male; D016106:Methicillin Resistance / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D015398:Signal Transduction / Q000235:genetics; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology; D013211:Staphylococcus aureus / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics
chemical_list: C095698:Agr protein, Staphylococcus aureus; D001426:Bacterial Proteins; D015534:Trans-Activators