Analysis of the relationship between the MecA gene and resistance of β-lactam antibiotics.
10.3969/j.issn.1672-7347.2012.06.005
- Author:
Hui HUANG
1
;
Jiandang ZHOU
;
Xinmin NIE
;
Qifeng YI
Author Information
1. Department of Nursing, Third Xiangya Hospital, Central South University, Changsha 410013, China.
- Publication Type:Journal Article
- MeSH:
Anti-Bacterial Agents;
pharmacology;
Bacterial Proteins;
genetics;
metabolism;
Cefoxitin;
pharmacology;
Drug Resistance, Multiple, Bacterial;
Methicillin-Resistant Staphylococcus aureus;
drug effects;
genetics;
metabolism;
Microbial Sensitivity Tests;
methods;
Oxacillin;
pharmacology;
Penicillin-Binding Proteins
- From:
Journal of Central South University(Medical Sciences)
2012;37(6):567-571
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE:To investigate the mechanisms by which MecA gene expression leads to β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA), and to study the resistance mechanism of MRSA at the molecular level.
METHODS:A variety of molecular biological techniques were employed, including screening MRSA using cefoxitin paper disk method, extraction of MRSA mRNA, reverse transcription into cDNA, real-time fluorescence PCR for quantitation of MecA gene expression, and agar dilution method for assessment of minimum inhibitory concentrations in MRSA treated with cefoxitin, oxacillin, vancomycin, or linezolid.
RESULTS:According to the level of resistance of MRSA to cefoxitin, 40 MRSA strains were divided into a low resistance group (n=12), a middle resistance group (n=15), and a high resistance group (n=13). The expression level of the MecA gene in the low resistance group, the middle resistance group, and the high resistance group was 58.87±30.30, 363.37±200.05, and 1257.72±446.63, respectively. MRSA resistance to cefoxitin and oxacillin was 100%; MRSA resistance to vancomycin or linezolid could not be detected. For all 40 MRSA strains the MIC90 for vancomycin was 2.0 μg/mL.
CONCLUSION:MecA gene expression levels may correlate with the MRSA level of resistance to cefoxitin within a certain range of concentration.
