Distribution and Antimicrobial Resistance Pattern of Bacteria Isolated from Operation Theaters at Gaza Strip

A five month prospective study was fulfilled to determine the prevalence of bacterial contamination in operation theaters at main hospitals of Gaza Strip, types and frequency of these bacteria and their antibiotic resistance pattern.

The bacterial isolates were identified by conventional methods and the antibiotic susceptibility profiles were determined by the standard disc diffusion method according to CLSI guidelines. 

Out of a total of 243 swabs investigated, 24.7% were contaminated and yielded bacterial genera. There were seven bacterial genera isolated with highest prevalence of Staphylococcus spp. (45.3%), followed by Enterobacter spp. (23.4%), Escherichia coli, Klebsiella spp. and Acinetobacter spp. (7.8% for each). The other genera include Pseudomonas spp. (4.7%) and Streptococcus spp. (3.1%). Most of the recovered isolates of the genus Staphylococcus were coagulase negative staphylococci accounting  89.7% of the total isolated staphylococci.

The antibiotic susceptibility profiles of Gram negative isolates revealed that the most effective antibiotics were imipenem and tobramycin with no resistance rate (0.0%), then amikacin with resistance rate of 6.1%, gentamicin 15.2%, and ciprofloxacin 27.3%. However, the highest resistance was against ampicillin and amoxicillin with 93.9% for each, followed by cefazolin 81.8%. On the other hand, Gram positive isolates (all are staphylococci) were also found to be highly resistant against penicillin and ampicillin (93.1%, 86.2 respectively). All isolates were completely sensitive and there was a lack of resistant isolates against vancomycin. However, low resistance pattern was revealed against rifampin, doxycycline (3.4% each) and ciprofloxacin (24.1%).

Among Gram negative isolates, there were 9.1% extended spectrum beta-lactamase producers which were from Escherichia coli (40%) and Klebsiella spp. (20%). Methicillin resistance was detected in 62.1% of staphylococci isolates, where methicillin resistance Staphylococcus aureus (MRSA) and methicillin resistance coagulase-negative staphylococci (MR-CoNS) account for 33.3% and 65.4% respectively.

In conclusion, this study demonstrated presence of moderate bacterial contamination in operation theaters with increased potential to the commonly used antimicrobial agents.

Keywords: Antimicrobial resistance pattern, Bacteria, Operation theaters, ESBL, MRSA.