Superantigen gene profiles and presence of exfoliative toxin genes in community-acquired meticillin-resistant Staphylococcus aureus isolated from Chinese children.
This study aimed to evaluate the distribution of superantigen gene profiles and the presence of exfoliative toxin genes in community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) isolated from Chinese children, and simultaneously to assess virulence gene profiles and genetic background. Of the CA-MRSA isolates, 88.9 % (88/99) harboured toxin genes, with sek as the most frequent toxin gene (62.6  %), followed by seq (61.6  %), seb (60.6  %) and sea (35.4  %). The eta gene was detected only in one ST398-IVa-spa t034 strain. The sed and etd genes were not found in any of the isolates tested. A total of 38 virulence genotypes were observed, of which the genotype seb-sek-seq (27.3  %, 24/88) comprised the majority, followed by sea-seb-sek-seq (18.2  %, 16/88). The enterotoxin gene cluster including seg-sei-sem-sen-seo-seu predominated at a rate of 15.1  %. The relationship among toxin genotypes, toxin genes encoding profiles of mobile genetic elements and genetic background was analysed. Among 66 clonal complex (CC) 59 isolates, 87.9 % (58/66) were positive for toxin genes, and 75.8  % (50/66) harboured the toxin gene combination seb-sek-seq. Among seb-sek-seq-positive CC59 strains, 42.0  % (21/50) also carried the sea gene. CC59 corresponded exclusively to accessory gene regulator 1 (agr-1). The data presented here enhance our current knowledge on the virulence determinants of CA-MRSA.
Wu
Dejing
D
Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China.
Li
Xiangmei
X
Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China.
Yang
Yonghong
Y
Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China.
Zheng
Yaojie
Y
Shenzhen Children's Hospital, 518026 Shenzhen, PR China.
Wang
Chuanqing
C
Pediatric Hospital of Fudan University, 201102 Shanghai, PR China.
Deng
Li
L
Guangzhou Children's Hospital, 510120 Guangzhou, PR China.
Liu
Lan
L
Chongqing Children's Hospital, 400014 Chongqing, PR China.
Li
Changcong
C
Affiliated Hospital of Wenzhou Medical College, 325000 Wenzhou, PR China.
Shang
Yunxiao
Y
Shenyang Shengjing Hospital, 110003 Shenyang, PR China.
Zhao
Changan
C
Guangzhou Maternal and Child Health Hospital, 510010 Guangzhou, PR China.
Yu
Sangjie
S
Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China.
Shen
Xuzhuang
X
Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China.
D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D002648:Child; D002681:China; D016000:Cluster Analysis; D017714:Community-Acquired Infections / Q000382:microbiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D005083:Exfoliatins / Q000235:genetics*; D005838:Genotype; D006801:Humans; D020071:Interspersed Repetitive Sequences; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000382:microbiology*; D018089:Superantigens / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D005083:Exfoliatins; D018089:Superantigens; D037521:Virulence Factors