Distribution of Genes Encoding Aminoglycoside Modifying Enzymes and Type Staphylococcal Chromosomal Cassette mec in Methicillin-resistant Staphylococcus aureus from Non-tertiary Hospitals.
- Author:
Young Hee JUNG
1
;
Kwang Wook KIM
;
Jeong Ok CHA
;
Kyeong Min LEE
;
Jae Il YOO
;
Jeong Sik YOO
;
Bong Su KIM
;
Young Ju OH
;
Hye Ryoung YOON
;
Yeong Seon LEE
Author Information
- Publication Type:Original Article
- Keywords: Aminoglycoside modifying enzyme; SCCmec; Methicillin resistant; Staphylococcus aureus
- MeSH: Adenosine; Amikacin; Amphotericin B; Anti-Bacterial Agents; Diffusion; Gentamicins; Kanamycin; Kanamycin Kinase; Methicillin; Methicillin Resistance; Methicillin-Resistant Staphylococcus aureus; Multiplex Polymerase Chain Reaction; Netilmicin; Plasmids; Sprains and Strains; Staphylococcus aureus; Tobramycin
- From: Infection and Chemotherapy 2008;40(1):32-39
- CountryRepublic of Korea
- Language:Korean
- Abstract: BACKGROUND: Many genes encoding aminoglycoside modifying enzymes (AMEs) on transposon or plasmid were transferred from one strain to another strain and inserted into a staphylococcal chromosomal cassette mec (SCCmec). There are very diverse subtypes in SCCmec type to the insertion of resistant genes. Therefore, we researched the resistance rates of antibiotics and distribution of AME genes according to SCCmec type in MRSA strains. MATERIALS AND METHODS: We isolated 640 Staphylococcus aureus from non-tertiary hospitals in 2004, detected mecA, aac(6')-aph(2"), aph(3')-IIIa, and ant(4')-Ia using the multiplex PCR method, tested antibacterial susceptibility disk diffusion and minimal inhibitory concentration, and determined SCCmec type. RESULTS: Of 640 S. aureus isolates, MRSA rate was 39.7% and all MRSA isolates carried mecA gene. Among 214 MRSA selected, aminoglycoside-resistant rates were 98.1% in kanamycin and tobramycin, 68.7% in gentamicin, 30.8% in amikacin, and 2.8% in netilmicin. The detection rates for aac(6')-aph(2"), aph(3')-IIIa, and ant(4')-Ia were 77.1%, 13.1%, and 53.3%, respectively. Also, SCCmec type was 50.9% in SCCmec type II, 16.4% in type III, and 32.7% in type IV. The genes encoding AMEs were distributed aac(6')-aph(2") (49.5%) and aac(6')-aph(2")/ant(4')-Ia (36.7%) in SCCmec type II, aph(3')-IIIa/aac(6')-aph(2") (60%) and aac(6')-aph(2") (31.4%) in type III, and aac(6')-aph(2")/ant(4')-Ia (41.4%) and ant(4')-Ia (50%) in type IV. CONCLUSION: 39.7% of S. aureus isolated from non-tertiary hospitals was resistant to methicillin. More than 90% of MRSA isolates were detected aac(6')-aph(2") in SCCmec type II and III, and ant(4')-Ia in type IV. With these results, the genes encoding AMEs may be closed related to SCCmec type.
