[Risk Factors of nasal carriage of methicillin-resistant staphylococcus aureus and its antibiotic susceptibility pattern in Namazi hospital healthcare workers in Shiraz, Iran]

Methicillin-resistant Staphylococcus aureus [MRSA] is a major nosocomial pathogen worldwide. The aim of this study was to determine the risk factors of nasal carriage of MRSA and its antibiotic susceptibility pattern among healthcare workers at Namazi Hospital [Shiraz-Iran]. In a cross-sectional study from July to November 2006, nasal swabs were taken from 600 stratified randomly selected health care workers. The isolates were identified as S. aureus based on morphology, gram stains, catalase test, coauglase test and DNase Agar. To differentiate Methicillinsusceptible S. aureus [MSSA] and Methicillin Resistant S. aureus [MRSA], agar screen plate was used. All methicillin-resistant isolates were examined for mecA genes existence by PCR performance. The sensitivity patterns of S.aureus isolates were determined by disc diffusion and E-test method. Nasal screening identified 186 [31%] S. aureus carriers of whom, 154 ones [82.8%] were MSSA and 32 ones [17.2%] were MRSA. There was no significant association between related risk factors and gender, age, years of healthcare service and level of education. In the univariate analysis, a statistically significant difference was found only based on occupation [P=0.032] between carriers of MSSA and MRSA. In multivariate analysis [logistic regression], having nursing occupation [p=0.012, OR=3.6, 95%CI=1.3-9.7] was independently associated with MRSA carriage. All of the MRSA strains were sensitive to mupirocin. This study revealed that having nursing occupation is independently associated with MRSA carriage since all S.aureus isolates were susceptible to mupirocin, topical mupirocin could be used successfully to eradicate nasal staphylococcal colonization and carriers

[Risk factors of rectal colonization of vancomycin-resistant enterococci in Shiraz Namazi Hospital]

Risk factors for Vancomycin-resistant Enterococci [VRE] colonization are patient-related factors such as underlying disease or amount of prescribed antibiotics, and hospital-related factors such as duration of hospitalization, type of performed therapeutic procedures, and antibiotic prescription. This nested case control study was performed to determine risk factors of rectal VRE colonization at Shiraz Namazi Hospital. During December 2003 to July 2004 serial rectal swabs were yielded from all hospitalized patients every 5 days. Susceptibility of detected Enterococci was tested by Minimum Inhibitory concentration dilution method. More than 1000 rectal swabs were taken. A total of 99 of 700 patients [14%] were colonized with VRE [cases] and 59 patients were colonized with Vancomycin-sensible strains [VSE], serving as controls. In the univariate analysis, history of antibiotic use [P=0.04], underlying disease [P=0.01], renal failure due to dialysis [P=0.03], use of vancomycin [P=0.04], use of third generation Cephalosporins [P=0.04], and duration of vancomycin therapy [>7 days] [p=0.02] showed statistically significant differences between the two groups. In the multivariate analysis [logistic regression], presence of underlying disease [OR, 2.43; 95% CI, 1.2 - 4.9; P=0.013] and duration of Vancomycin use [>7 days] were independently associated with VRE colonization. This study, which was the first study on the prevalence of VRE in Iran, demonstrated that VRE prevalence is high in Shiraz, and confirmed earlier observations regarding risk factors for VRE in other countries and determined risk factors that may be considered in interventional strategies for the control of VRE