Objective: To determine the point prevalence of, and risk factors associated with MRSA carriage among resident physicians of surgical departments at the Ospital ng Maynila Medical Center. Methods: Design: Cross-sectional Study. Setting: Tertiary Government Training Hospital. Participants:51 resident physicians from different surgical departments (general surgery, obstetrics and gynecology, ophthalmology, otorhinolaryngology – head and neck surgery and dermatology) underwent nasal and pharyngeal swabs with microbial culture and sensitivity testing to identify MRSA carriers. Fisher Exact Test and logistic regression were utilized to determine associations between MRSA carriage and various risk factors including frequency of hand washing and departmental affiliation. Results: Overall prevalence rate of MRSA carriage was 9.8%. Otorhinolaryngology residents had the highest combined prevalence of MRSA of 42.9%, significantly higher compared to other departments and were used as a reference in logistic regression analyses. Notably, handwashing only once daily was associated with a 20-fold increase in the risk of MRSA carriage (OR 20.5, 95% CI: 1.82 to 230, p = .014). Other departments did not demonstrate statistically significant differences in MRSA carriage rates. Conclusions Otorhinolaryngology resident physicians had the highest combined prevalence of MRSA and nasal MRSA was found only in otorhinolaryngology residents. The surgical subspecialty and frequency of handwashing of the healthcare worker were identified as important risk factors to develop MRSA carriage. Targeted interventions (including enhanced infection control protocols and regular screening) are needed especially in high-risk departments.
Methicillin-Resistant Staphylococcus aureus ; Surgical Wound Infection

No abstract available.
Cross Infection* ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus*

PURPOSE: This study was undertaken to find two things. One was to reveal the infection route of methicillin resistant Staphylococcus aureus(MRSA) that causes serious nosocomial infection through epidemic study, and the other was to seek preventative methods through blocking the dispersion. MATERIALS AND METHODS: We cultured MRSA obtained by nasal cavity swabbing, from 82 doctors and 219 personnel in our hospital, between September 1997 and August 1999. In addition, swabs were taken from the nasal cavities and surgical sites of 57 orthopaedic surgery patients, who were free of wound infection. In this practice, we use the disc test for drug sensitivity, and pulse-field gel electrophoresis (PFGE) to separate colonies. RESULTS: MRSA was discovered in 8 doctors (10%) and in 13 personnels (6%) by nasal cavity sabbing, and these included 3 orthopaedic surgeons. MRSA was also found in the patients' group, there were 23 (40%) from nasal cavities and 14 ones (25%) from surgical sites. Their PFGE types of MRSA were of A type, which were also identified in two orthopaedic surgeons. SUMMARY: We noticed that nasal cavitiy infection could occur by cross infection between doctors and patients. Surgical wound infection may occur by infection from the nasal cavity. This study underlines the importance of MRSA infection and management.
Cross Infection ; Electrophoresis ; Humans ; Methicillin Resistance* ; Methicillin* ; Methicillin-Resistant Staphylococcus aureus ; Nasal Cavity ; Staphylococcus* ; Surgical Wound Infection ; Wound Infection

Staphylococcus aureus, the pathogen in acute pyogenic infection and one of the important microbes causing nosocomial infection, was isolated from the mouth and anterior nare of healthy personnel and patients and the air in the dental clinic. The patterns of antibiotic susceptibility of the isolated staphylococci were examined. mecA gene from the MRSA was detected by polymerase chain reaction (PCR). The isolation rate of S. aureus in the dental clinic was the highest in the mouth of dentists (29.4%) and the lowest in the air of the dental clinic (1.3%). In the study of PCR, MRSA and some methicillin susceptible staphylococci had mecA positive gene. These results suggest that staphylococci in the dental environment might be one of the important causes of nosocomial infection in the dental clinic.]]>
Cross Infection ; Dental Clinics ; Dentists ; Humans ; Methicillin ; Methicillin-Resistant Staphylococcus aureus ; Mouth ; Polymerase Chain Reaction ; Staphylococcus aureus ; Staphylococcus

Methicillin-resistant Staphylococcus aureus (MRSA) is a typical pathogen of nosocomial infection, and has recently emerged as an important community-acquired pathogen. MRSA is notorious as a multidrug-resistant organism. Its resistance to all beta-lactams is mediated by PBP2a which is encoded by mecA, and it is also resistant to many antimicrobials of other classes due to frequently co-carrying resistance genes, which accounts for becoming a clinical and laboratory issue. This article reviews the microbiological characteristics, surveillance methods, and molecular epidemiology of MRSA.
Adenosine ; beta-Lactams ; Carrier State ; Cross Infection ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Molecular Epidemiology

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent nosocomial pathogens in Korea. The prevalence of MRSA is nearly 70% of clinical isolates of S. aureus, and the importance of infection control has increased. Many DNA-based molecular techniques have been introduced to type MRSA strains, but no single method of molecular techniques is universally applicable. This review summarizes the molecular techniques in epidemiological analyses of MRSA, describing some practical applicatiais of these techniques.
Epidemiologic Methods* ; Infection Control ; Korea ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus* ; Prevalence

BACKGROUND: It is now recognized that screening for methicillin-resistant Staphylococcus aureus (MRSA) in hospital is an effective infection control measure, and selective media-based methods have been commonly used. MRSASelect (MRSAS; Bio-Rad, Hercules, CA, USA) is MRSA selective agar incorporating chromogenic enzymatic substrates, and have been found to be more sensitive and specific than other selective media. The aim of present study was to evaluate MRSAS for discrimination of MRSA from other staphylococci by comparison with mannitol-salt agar with oxacillin (MSO) which is widely used as a MRSA selective medium. METHODS: Ninety-eight staphylococcal strains which were isolated from blood culture specimen, representing 16 MRSA, 6 methicillin-susceptible S. aureus, 59 methicillin-resistant coagulase- negative staphylococci (MRCNS), and 17 methicillin-susceptible coagulase-negative staphylococci were tested. The isolated colonies from pure culture were directly inoculated onto MSO and MRSAS respectively. On MRSAS any growth appearing pink after 24 hours incubation, and on MSO any growth appearing yellow after 48 hours incubation was interpreted as positive for the presence of MRSA. RESULTS: Sensitivities of MRSAS and MSO for MRSA detection were equal (93.8%). Specificities for MRSA discrimination from other staphylococci were 98.8% and 89.0%, and especially from MRCNS were 100% and 84.7%, for MRSAS and MSO, respectively. CONCLUSIONS: The MRSAS showed equal sensitivity compared with MSO for the detection of MRSA. MRSAS showed higher specificity than MSO in discrimination MRSA from MRCNS. It was suggested that the implementation of MRSAS in MRSA screening could decrease the work needed for MRCNS identification.
Agar ; Discrimination (Psychology) ; Infection Control ; Mass Screening ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Oxacillin ; Sensitivity and Specificity

BACKGROUND: This study investigated the effectiveness of reinforced contact precautions and active surveillance cultures (ASCs) in reducing the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and other healthcare-associated infections (HAIs). METHODS: A before- and after-experimental study was performed at the intensive care unit (ICU) in a university-affiliated hospital. Reinforced contact precautions were applied to all patients, and ASCs for MRSA were performed for newly admitted patients at the time of admission and once a week thereafter. The HAIs were investigated in accordance with the National Nosocomial Infections Surveillance (NNIS) definitions and compared before and after the interventions. The data were analyzed using descriptive statistics. RESULTS: The number of HAIs caused by MRSA decreased from 2.2 to 0.5 per 100 patients discharged (P=0.02) and from 3.6 to 1.0 per 1,000 patient-days (P=0.032). The number of overall HAIs decreased from 7.6 to 4.0 per 100 patients discharged (P=0.011) and from 12.7 to 7.3 per 1,000 patient-days (P=0.034). The invasive device-associated infections caused by MRSA and other pathogens decreased, but the decrease was not statistically significant. CONCLUSION: Reinforced contact precautions and ASCs were effective in decreasing both MRSA infections and overall HAIs in the ICU. Further, it was assumed that the incidence of device-associated infections would have decreased if the intervention period was extended.
Cross Infection ; Humans ; Incidence ; Critical Care ; Intensive Care Units ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the important causative microbes for nosocomial infection and has been isolated from the dental environment. The purpose of this study was to investigate the antimicrobial activity of linalool and alpha-terpineol against MRSA isolates from a Korean population. In the experiments, we determined the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these two compounds against 18 strains of MRSA. The data revealed that the MIC90/MBC90 values of linalool and alpha-terpineol against MRSA were >12.8 mg/ml and 6.4 mg/ml, respectively. These results indicate that alpha-terpineol has more potent antimicrobial activity against MRSA than linalool and may have utility as an anti-MRSA cleansing agent for dental instruments and dental unit chairs.
Cross Infection ; Cyclohexenes ; Dental Instruments ; Detergents ; Methicillin Resistance ; Methicillin-Resistant Staphylococcus aureus ; Microbial Sensitivity Tests ; Monoterpenes

BACKGROUND: A rapid and sensitive surveillance culture has a pivotal role in infection control of methicillinresistant Staphylococcus aureus (MRSA). This study was aimed to compare the performance of MRSASelect (Bio-Rad, France) to that of mannitol salt agar containing 6 microgram/mL of oxacillin (MSA-OX) for detecting MRSA in surveillance cultures. METHOD: From May to June 2006, 86 nasal swabs and 21 sputum specimens were enrolled. All specimens were inoculated onto MRSASelect and MSA-OX, which were incubated for 2 days and 3 days, respectively, and colonies were read daily by a technologist. Pink colonies on MRSASelect and yellow colonies on MSA-OX were examined with Gram stain, Pastorex(R) Staph-plus (Bio-Rad) and mecA-PCR. After the final reading, both media were re-examined by a superviser. RESULTS: Of the 107 specimens cultured, 32 (29.9%) were positive for MRSA. Of these, 27 were detected by both media, one by MSA-OX only, and 4 by re-examination. The day-1 and day-2 sensitivities/specificities of MRSASelect were 78.1%/97.3% and 84.4%/97.3%, respectively, while those of MSA-OX were 53.1%/100% and 78.1%/92.1%, respectively. With MRSASelect, two more positives were detected at day 2, but their incubation was less than 18 hour at day 1. There were six false positive organisms detected: three Enterobacter spp., one Acinectobacter spp., and two coagulase-negative staphylococci (CNS). But, the two CNS grew on MSA-OX only. CONCLUSION: MRSASelect with 1-day incubation showed a sensitivity equivalent to and a specificity better than MSA-OX with 2-day incubation. MRSASelect should be a useful medium for MRSA surveillance when it is read after an incubation of 18-28 hours with the confirmatory Gram stain of screen-positives.
Agar ; Enterobacter ; Infection Control ; Mannitol ; Methicillin Resistance* ; Methicillin-Resistant Staphylococcus aureus* ; Oxacillin ; Sensitivity and Specificity ; Sputum ; Staphylococcus aureus