Isolation and antibiotic susceptibility of Salmonella, Shigella, and Campylobacter from acute enteric infections in Egypt.

ABSTRACT

While Campylobacter, Salmonella, and Shigella remain major contributors to acute enteric infections, few studies on these pathogens have been conducted in Egypt. From January 1986 to December 1993, 869 Salmonella, Shigella and Campylobacter strains were isolated from stool specimens from 6,278 patients, presenting to the Abbassia Fever Hospital, Cairo, Egypt, with acute enteric infections. Salmonella predominated, totalling 465 isolates, followed by Shigella with 258 isolates, and Campylobacter with 146 isolates. Of the Shigella isolates, 124 were Shigella flexneri, 49 were S. sonnei, 47 were S. dysenteriae (mainly serotype 1, 2, and 3), and 38 were S. boydii. Campylobacter spp. comprised 92 Campylobacter jejuni and 54 C. coli isolates. Isolation of Salmonella was highest during the months of February-March, June-July, and October-November, while that of Shigella was maximal from July to October. Isolation of Campylobacter increased during May-June and again during August-October. Although Salmonella was sensitive to amikacin, aztreonam, ceftriaxone, and nalidixic acid, it was, however, resistant to erythromycin, streptomycin, ampicillin, chloramphenicol, and tetracycline. Shigella (> 80%) was sensitive to amikacin, ceftriaxone, cephalothin, sulphamethoxazole-trimethoprim (except S. sonnei), aztreonam, and nalidixic acid. Resistance (> 50%) was noted only for ampicillin, chloramphenicol, and tetracycline. C. jejuni and C. coli were resistant to cephalothin, aztreonam, and streptomycin. Some of the above antibiotics were employed to characterize the Egyptian isolates, but did not have any clinical utility in the treatment of diarrhoea. Significant differences (p < 0.05) were observed in the resistance profiles of Shigella and Salmonella between late 1980s and early 1990s. The results suggest the use of fluoroquinolones or a third-generation cephalosporin as an empirical treatment of enteric diseases. However, alternative control strategies, including the aggressive development of broadly protective vaccines, may be more effective approaches to curbing morbidity and mortality due to acute enteric infections.