Prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus and its antibiotic susceptibility pattern in healthcare workers at Namazi Hospital, Shiraz, Iran
ABSTRACT The aim of this study was to determine the prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among healthcare workers (HCWs) at Namazi Hospital, Shiraz, Iran.
This cross-sectional study was conducted from July to November 2006. Nasal swabs were taken from 600 randomly selected HCWs. The isolates were identified as S. aureus based on morphology, Gram stain, catalase test, coagulase test, and mannitol salt agar fermentation. To analyze sensitivity patterns of MRSA strains more precisely, minimum inhibitory concentrations (MICs) of antibiotics were determined by the E-test method. All methicillin-resistant isolates were examined for the existence of the mecA gene by total DNA extraction and PCR.
The prevalence of nasal carriage of methicillin-sensitive S. aureus (MSSA) was 25.7% and of MRSA was 5.3%, with the highest nasal carriage of MRSA in surgical wards and the emergency department. There was no significant difference between the sexes (p=0.247), age (p=0.817), and years of healthcare service (p=0.15) with regard to the nasal carriage of MRSA and MSSA. In the univariate analysis, a statistically significant difference was only found for occupation (p=0.032) between the carriage of MSSA and MRSA. In the multivariate analysis, the occupation 'nurse' was independently associated with MRSA carriage (p=0.012, odds ratio 3.6, 95% confidence interval 1.3-9.7). The highest resistance rate for both gentamicin and clindamycin (69%) was noted among the MRSA strains. None of the MRSA strains were resistant to mupirocin, linezolid, fusidic acid, or vancomycin. The existence of the mecA gene in all 32 methicillin-resistant isolates was observed by PCR.
This study revealed the prevalence of nasal carriage of S. aureus strains among HCWs to be lower than that found in other studies from Iran. The antibiotic susceptibility patterns also differed, perhaps as a result of the excessive use of antibiotics at our hospital. Only the occupation of nurse was an independent risk factor for MRSA carriage.
- SourceAvailable from: Davood Mehrabani[Show abstract] [Hide abstract]
ABSTRACT: Background: Blood infections are life-threatening if not detected and managed properly. This study investigatesthe correlation between fever and previous antibiotics therapy with differential time to positivity (DTP) at admittedpatients at Nemazee Hospital in Shiraz, southern Iran.Methods: From January 2005 to December 2006, 985 positive blood samples in Bactec bottles from the admittedpatients at Nemazee Hospital were analyzed. Sensitivity patterns of the bacteria to a panel of antibiotics weredetermined by the disk diffusion method.Results: S. epidermidis, S. aureus and Acinetobacter were the most prevalent isolates respectively. However,only 100 (20.7%) S. epidermidis samples were the true infections. The most susceptible Gram positive and negativebacteria were S. viridance, S. aureus, H. influenzae, and Brucella spp., respectively. Imipenem, amikacinand ciprofloxacin were the effective ones against Gram negative bacteria, while vancomycin, co-amoxiclav andchloramphenicol were effective against Gram positive ones. Cefuroxime and penicillin G were less effectiveantibiotics against both Gram negative and positive bacteria.Conclusion: As demonstrated, the combined prescription of vancomycin and imipenem seems to cover themajority of infective agents in the blood whenever an empirical therapy is to be initiated. Moreover, periodicsurveillance of antibacterial susceptibility patterns is warranted.
- [Show abstract] [Hide abstract]
ABSTRACT: The purpose of this study was to determine the nasal carriage rate of Staphylococcus aureus in hemodialysis patients and the antibiogram of all isolated S. aureus from carriers. A cross-sectional study was carried out from May to September 2007. 130 patients (49 females, 81 males; mean age 55.6 +/- 15.2 years) with chronic renal failure were included in the study. The patients had undergone hemodialysis for at least 12 months in the dialysis ward of Faghihi Hospital, a referral center in Shiraz, Iran. Swab specimens were taken from the anterior nares and skin of the patients and cultured microbiologically. Next, antibiotic susceptibility tests were performed for all of the isolated S. aureus. 32 (24.6%) patients (95% CI 17.5-32.9%) were nasal carriers of S. aureus versus 98 (75.4%) non-carriers. S. aureus was also isolated from skin of 5 (3.8%) patients who were nasal carriers as well. The isolated S. aureus were 100, 97.3, 73.0, 70.3, 40.5 and 21.6% sensitive to vancomycin, rifampin, ciprofloxacin, tetracycline, methicillin and erythromycin, respectively. Because the nasal carriage rate of S. aureus observed in dialysis patients in this study was relatively high, we recommend screening for S. aureus in hemodialysis patients to enable prompt prevention strategies.Medical Principles and Practice 01/2010; 19(5):379-83. DOI:10.1159/000316377 · 1.11 Impact Factor