Objective: To determine the predominant serotype and antibiotic sensitivity pattern of Shigella isolates during 2004 and 2005 in Zimbabwe.
Design: Cross sectional study.
Setting: National Microbiology Reference Laboratory (NMRL), Harare, Zimbabwe.
Sample: 259 clinical isolates of Shigella species isolated during 2004 and 2005 in Zimbabwe were studied. These samples had been referred to the NMRL for further testing.
Main outcome measures: Serotype and antibiotic sensitivity pattern of Shigella species.
Results: Of the 259 clinical isolates of Shigella tested the following species were serotyped; 141 (54.4%) were S. flexneri; 70 (27%) S. sonnei; 38 (14.7%) S. dysenteriae and 10 (3.9%) S. boydii. About 4% of all Shigella isolates tested showed full sensitivity to commonly used antibiotics, 20.8% were resistant to one antibiotic only while 75.3% were resistant to at least two antibiotics. The most common resistance among Shigella species was to cotrimoxazole (89%), tetracycline (73%), ampicillin (49%) and chloramphenicol (41%). High susceptibility among Shigella species was observed to nalidixic acid (86%), ciprofloxacin (99%) and ceftazidine (99%).
Conclusion: There was a low drug resistance of Shigella species to nalidixic acid, a drug of choice in Zimbabwe, except among Shigella dysenteriae type 1 strains. Continuous monitoring of the susceptibility patterns of Shigella species is important in order to detect the emergence of drug resistance and to update guidelines for antibiotic treatment in shigellosis.