Antimicrobial resistance in Salmonella enterica serovar Enteritidis in Morocco

Introduction: Salmonella enterica is recognised worldwide as one of the major agents of human gastrointestinal infections. The aim of the present work is to ascertain the antimicrobial susceptibilities of 150 Salmonella enterica serovar Enteritidis isolates from humans in Morocco during the period from 2000 to 2008. Methodology: Antimicrobial resistance determination was performed by disk diffusion method using seven antibiotics. The minimal inhibitory concentration (MIC) of ciprofloxacin was determined for nalidixic acid-resistant (NAR) isolates using E-test strips. Results: Sixty-one (42%) isolates were resistant to at least one class of antimicrobial agent. The largest numbers of resistant isolates were observed for nalidixic acid with 53 isolates (36%) followed by ampicillin with 7 isolates (5%), tetracycline with 6 isolates (4%), and trimethoprim/sulfamethoxazole with 2 isolates (1%). The resistant isolates were grouped in seven different resistance patterns of which two isolates were resistant to three antibiotics. Among the 53 (36%) NAR isolates, 37 (76%) had a reduced susceptibility to ciprofloxacin. Conclusion: Resistance rates of Salmonella enterica serovar Enteritidis from Morocco are generally low but the resistance to nalidixic acid is worryingly common. Continual surveillance of antibiotic resistance is of primary importance.