Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important antibiotic-resistant bacteria that cause hospital-aquired infections.There is no information on MRSA in Kerbala hospitals. Therefor, a screening programme for MRSA in three main hospitals in Kerbala city (Maternity hospital , Al-Hussein General hospital ,Kerbala Pediatric hospital) has been done during the period from October,2008 till November,2009. The study included the collection of 98 MRSA isolate among 637 sample taken from inpatients,medical staff and hospitals wards environment. The sensitivity to methicillin and other antibiotics was tested. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of some antiseptics and disinfectants that used in hospitals was detected. The mutagenic effect of sub-inhibitory concentration of this chemicals on the conversion of methicillin sensitive Staphylococcus aureus to methicillin resistant Staphylococcus aureus was studied. Furthermore the plasmid profile of some MRSA and MSSA isolates that converted to MRSA was also studied.
The results of this study shown that the highest precentage of MRSA prevalence among inpatients of three hospitals was in maternity hospital (18.82%) and the precentage was approximate for both Al-Hussein General hospital and Kerbala Pediatric hospital (17.94% ,17.28%) respectivily.
Also the highest precentage of MRSA prevalence among medical staff of three hospitals was in maternity hospital (31.81%) followed by Al-Hussein General hospital (17.64%) and the lowest percentage was in Kerbala pediatric hospital (13.63%).
The highest precentage of MRSA prevalence among hospitals wards environment of three hospitals was in maternity hospital (22.5%) followed Kerbala pediatric hospital (11%) and the lowest percentage was in Al-Hussein General hospital (9.16%).
The results of antibiotic sensitivity showed that the highest percentage of antibiotic resistance was among the isolates of hospitals wards environment of the three hospitals but the lowest percentage was among the isolates of medical staff.
The highest percentage of antibiotic resistance among all isolates was to Methicillin and the lowest percentage was to Imipenem.
The result of The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of some antiseptics and disinfectants that used in hospitals such as ( Formalin ، Chlorine ، Ethyl Iodide ،Povidon-Iodine، Ethanol ،Chlorhexidin gluconate ) were(782.63 ، 24.45) µg/ ml, (1462.5 ، 731.25) µg/ ml , (1250 ، 625) µg/ ml, (12500 ، 6250) µg/ ml, ( 24519.9 ، 6129.9)µg/ ml , (39.06 ،0.15 ) µg/ ml respectively.
The study showed that MRSA isolate was less resistant to Chlorhexidin gluconate and Ethyl-iodide.
The sub-inhibitory concentration of antiseptics and disinfectants that used in hospitals had a mutagenic effect on the convertion of MSSA to MRSA.
The results of plasmid profile of six MRSA isolates and MSSA isolates that exposed to sub-inhibitory concentration of disinfectants and antiseptcs were had two small size plasmid bunds.