Molecular Epidemiology and Antimicrobial Resistance of Methicillin-resistant Staphylococcus aureus Isolated from Nasal Swab at Intensive Care Unit.

Kwak, Om Sub; Kwon, Mee Hye; Jeong, Ji Hyun; Kang, Mi il; Cheun, Ji Young; Lee, Go Eun; Kim, Young Keun; Choi, Eu Gene; Na, Moon Jun; Kwon, Hee Uk; Son, Ji Woong

doi:2008.65.2.91

Tuberc Respir Dis > Volume 65(2); 2008 > Article

Original Article

Tuberculosis and Respiratory Diseases 2008;65(2):91-98.
DOI: https://doi.org/10.4046/trd.2008.65.2.91 Published online August 1, 2008.

Molecular Epidemiology and Antimicrobial Resistance of Methicillin-resistant Staphylococcus aureus Isolated from Nasal Swab at Intensive Care Unit.

Om Sub Kwak, Mee Hye Kwon, Ji Hyun Jeong, Mi il Kang, Ji Young Cheun, Go Eun Lee, Young Keun Kim, Eu Gene Choi, Moon Jun Na, Hee Uk Kwon, Ji Woong Son

¹Department of Internal Medicine, College of Medicine, Konyang University, Daejeon, Korea. sk1609@hanmail.net
²Department of Anesthesiology and Pain Medicine, College of Medicine, Konyang University, Daejeon, Korea.

Abstract

BACKGROUND
Methicillin-resistant Staphylococcus aureus (MRSA) is the most common organism associated with nosocomial infections. MRSA infections are becoming increasing important because they have emerged no only as healthcare-associated (HA) infections but also as community-associated (CA) ones. This study examined the moleculo-epidemiology of MRSA, which was isolated from nasal swabs in the intensive care unit (ICU) at Konyang University Hospital. MRSA are classified into HA-MRSA and CA-MRSA. METHODS: From June to September 2006, 353 patients who were admitted to the ICU in Konyang University Hospital were enrolled in this study. Single nasal swabs were obtained for culture in the ICU on the 1st day. Pulsed-field gel electrophoresis and the antimicrobial resistant patterns were analyzed between HA- and CA-MRSA. An antimicrobial sensitivity test was also performed. RESULTS: Forty two strains of MRSA were isolated from 353 patients (11.9%). Among the 42 isolates, HA-MRSA and CA-MRSA were found in 33 (78.6%), and 9 (21.4%), respectively. Eleven different PFGE types (type A to K) were identified. Types A (n=9) and B (n=7) were the most common for HA-MRSA, and types A (n=2) and B (n=2) were identified in CA-MRSA. The proportion of types A and B in CA-MRSA (44.4%) was similar to that in HA-MRSA (48.5%). The rates of resistance rates to erythromycin and ciprofloxacin were higher in HA-MRSA than in CA-MRSA. CONCLUSION: The rate of isolation of MRSA in an ICU setting was 11.9%. HA-MRSA was isolated more frequently than CA-MRSA. The rate of resistance of HA-MRSA to erythromycin and ciprofloxacin was higher than that of CA-MRSA. Despite the small number of subjects, the main isolates (type A and B) of CA-MRSA were similar to those of HA-MRSA.

Key Words: Methicillin-resistance, Staphylococcus aureus, Pulsed-field gel electrophoresis