Staphylococcus aureus, Enterococus spp, Enterobacteriaceae and Pseudomonas aeruginosa isolated from the coastal water of the Gaza strip-Palestine

Objectives: To document the occurrence and distribution of antibiotic resistance of clinically important bacteria in the seawater of Gaza strip-Palestine. Methods: Seawater samples were collected at 16 location distributed along the coast of the Gaza strip. Sampling was accomplished during 12 months, from March 2014 to June 2015. The microbial composition including Enterobacteriaceae, Staphylococcus aureus, fecal streptococci and Pseudomonas aeruginosa was recorded and tested for their resistance to specific antimicrobial agents according to CLSI using the disc diffusion method. Results: A total of 816 isolates of Enterobacteriaceae (377), S. aureus (29), fecal enterococci (FS) (369), and P. aeruginosa (29) were recovered and identified. Enterobacteriaceae, P. aeruginosa, FS and S. aureus isolates exhibited the highest rates of resistance against β-lactam drugs. The isolates also showed resistance to at least one antimicrobial in the range between 99.7 to 78%. Multiple resistance occurred in almost 85% of all isolates; 99.2% of Enterobacteriaceae, 96.6% of P. aeruginosa, 72.1% of FS and 61% of S.aureus. The incidence of multiple resistance of isolates from all sampling locations ranged from 69.2 to 94.1%. Antibiotic resistance indices were found to be highest in P. aeruginosa (0.57), followed by E. coli (0.53), FS (0.49), Enterobacter (0.41), S. marcescens (0.40), Klebsiella (0.39) and finally Proteus (0.28). Most of the isolates showed multiple antibiotic resistance (MAR) index value higher than 0.2. Conclusions: This study demonstrated that the seawater of the Gaza strip is highly contaminated with antibiotic resistant bacteria which can be transmitted to humans through recreational and other activities. Therefore, there is a need to apply appropriate and rationale use of antibiotic to minimize the occurrence of multiple antibiotic resistant bacteria in the marine environment. Proper treatment of sewage before it is discharged to the sea is highly recommended.Keywords: Multiple antimicrobial resistance, Gaza strip, seawater, fecal enterococci, P. aeruginosa, Enterobacteriaceae, S. aureus.