Nosocomial infection caused by methicillin-resistant Staphylococcus aureus in Palestine

Nasal carriage of methicillin resistant Staphylococcus aureus among health care workers at Al Shifa hospital in Gaza Strip

Background

Nasal carriage of Staphylococcus aureus among hospital personnel is a common cause of hospital acquired infections. Emergence of drug resistant strains especially methicillin resistant S. aureus (MRSA) is a serious problem in hospital environment. Therefore, the aim of this study was to determine the nasal carriage rate of S. aureus and MRSA among Health Care Workers (HCWs) at Al Shifa Hospital, the major hospital in Gaza Strip.

Methods

A cross sectional study was conducted on 200 HCWs. Nasal swabs were collected during February — April 2015, and cultured on blood and mannitol salt agar. The isolates were identified as S. aureus based on morphology, coagulase test, DNase test and mannitol salt agar fermentation. Disk diffusion antibiotic susceptibility tests were performed according to the guidelines of the Clinical and Laboratory Standards Institute. MRSA were confirmed by detection of the mecA gene by PCR.

Results

Out of the 200 healthcare workers, 62 (31%) carried S. aureus, of which 51 (82.3%) were MRSA. Therefore, 25.5% of all HCWs were identified as MRSA carriers. MRSA carriage rate was highest among nurses (30.4%) whereas the carriage rate among doctors was (16%). The majority of MRSA carriers were workers of internal medicine department and surgical wards (41.3 and 35% respectively). Out of the 51 MRSA isolates identified by oxacillin disc resistance, 40 were confirmed by PCR targeting the mecA gene. Penicillin showed the highest rate of resistance among MRSA and MSSA isolates (100%).

Conclusions

The high rate of nasal MRSA carriage among healthcare workers found in this study is alarming and highlights the need for adjusted infection control measures to prevent MRSA transmission from HCWs to the vulnerable patient.

MRSA clonal complex 22 strains harboring toxic shock syndrome toxin (TSST-1) are endemic in the primary hospital in Gaza, Palestine

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen in both community and healthcare-related settings worldwide. Current knowledge regarding the epidemiology of S. aureus and MRSA in Gaza is based on a single community-based carriage study. Here we describe a cross-sectional analysis of 215 clinical isolates collected from Al-Shifa Hospital in Gaza during 2008 and 2012.

Methods

All isolates were characterized by spa typing, SCCmec typing, and detection of genes encoding Panton-Valentine leukocidin (PVL) and toxic shock syndrome toxin (TSST-1). Representative genotypes were also subjected to multilocus sequence typing (MLST). Antibiotic susceptibility testing was performed using VITEK2 and MicroScan.

Results

MRSA represented 56.3% of all S. aureus strains, and increased in frequency from 2008 (54.8%) to 2012 (58.4%). Aside from beta-lactams, resistance was observed to tetracycline, erythromycin, clindamycin, gentamicin, and fluoroquinolones. Molecular typing identified 35 spa types representing 17 MLST clonal complexes (CC), with spa 998 (Ridom t223, CC22) and spa 70 (Ridom t044, CC80) being the most prevalent. SCCmec types I, III, IV, V and VI were identified among MRSA isolates, while type II was not detected. PVL genes (lukF/S-PV) were detected in 40.0% of all isolates, while the TSST-1 gene (tst) was detected in 27.4% of all isolates, with surprisingly high frequency within CC22 (70.4%). Both PVL and TSST-1 genes were found in several isolates from 2012.

Conclusions

Molecular typing of clinical isolates from Gaza hospitals revealed unusually high prevalence of TSST-1 genes among CC22 MRSA, which is noteworthy given a recent community study describing widespread carriage of a CC22 MRSA clone known as the ‘Gaza strain’. While the latter did not address TSST-1, tst-positive spa 998 (Ridom t223) has been detected in several neighboring countries, and described as endemic in an Italian NICU, suggesting international spread of a ‘Middle Eastern variant’ of pandemic CC22 strain EMRSA-15.

Molecular characterization of methicillin-resistant Staphylococcus aureus isolates in three different Arab world countries

Molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolates in three different Arab world countries (West Bank of Palestine, Jordan, and Iraq) was the aim of the study presented here. This is done on the basis of spa sequencing and staphylococcal cassette chromosome mec (SCCmec) typing. The majority (92%) of the spa-tested isolates belonged to spa type t932 and possessed the (SCCmec) type III. These data suggest that MRSA clone, which harbors the spa type t932 and (SCCmec) type III, had been transferred throughout the three studied countries.

Trimethoprim-sulfamethoxazole for methicillin-resistant Staphylococcus aureus: a forgotten alternative?

Methicillin-resistant Staphylococcus aureus (MRSA) is a growing infectious concern, mainly in the context of its rapid adaptation to novel antibiotic options for its treatment and the growing morbidity, mortality, and healthcare costs associated with its emergence. the authors sought to investigate whether an older antibiotic, such as trimethoprim-sulfamethoxazole (SXT), may have a role in treating MRSA-related infections, according to the available literature on the subject. The authors reviewed literature data on: resistance of MRSA to SXT worldwide in recent years, efficacy of SXT for MRSA decolonization or prophylaxis from MRSA infections, and clinical therapeutic efficacy of SXT in treating mild or severe community-acquired or hospital-acquired MRSA infections. Resistance varies worldwide, in general being low in the industrialized world and higher in developing countries. SXT is one of the numerous understudied options for MRSA decolonization and is growingly recognized as potentially effective in preventing MRSA infections in certain settings. Limited data on its therapeutic efficacy are encouraging, at least for mild, community-acquired infections. SXT may represent a cost-effective alternative weapon against MRSA. Its utility against this increasingly threatening pathogen need clarification through further clinical trials.