Drug Resistance Pattern of Diarrheogenic Enterobacteriaceae among HIV Seropositive Individuals on Cotrimoxazole Prophylaxis at St. Paul’s Hospital, Addis Ababa

Back ground: Reduced efficacy of available drugs and anti-microbial resistance are challenges for control of infectious diseases. In recent years multi-drug resistant strains of bacteria has posed major public health problems. Hence prevention and control strategies should be implemented based on the studies available on pattern of drug resistance and prevalence of infectious agents particularly in resource limited countries, furthermore periodic surveillance of antibiotic resistance and effectiveness against common bacterial infections should be monitored.  Objectives: To assess antibiotic resistance pattern of diarrheognic Enterobacteriaceae among HIV infected ART-Naive as well as ART-experienced individuals. Methods: A hospital based cross-sectional study was conducted on individuals taking co-trimoxazole prophylaxis and presented with complaints of diarrhea. Stool samples were collected and examined by culture and sensitivity testing was done to evaluate antibiotic resistance patterns of selected diarrheogenic Enterobacteriaceae. Result: From a total 162 HIV sero-positive co-trimoxazole taking patients presented with diarrhea, three types of bacterial isolates were observed in 14.8% of study participants. Most Prevalent bacterial isolates were Shigella species (6.8%), Salmonella paratyphi (4.9%) and Salmonella typhi (3.1%).  Most frequently recovered bacterial isolates were resistant to co-trimoxazole with over all resistance pattern of (91.7%) and this isolates were also susceptible  to Ceftraxone; next to Ceftraxone, the isolates was sensitive to Chloramphenicol (66.7%) than Naldixic acid and Nitroforantione. The most multi drug resistant bacteria isolates were S.typhi which is 100 resistant against co-cotrimoxazole, Ampicilline, Nitroforantine and Naldixic acid. Despite high resistance pattern of co-trimoxazole, statistically significant improvement of CD4 T cell level was seen  after cotrimoxazol prophylaxis and highly active anti-retroviral treatment, compared to baseline count with the mean difference of  169/mm3 CD4 T-cell (paired t-test, p<0.001). WHO clinical stage, types of water source and raw vegetable consumption did not show a significant association with enteric bacterial infection and antibiotic resistance. Conclusion: In present study, bacterial resistance to co-trimoxazole was found to be very high; hence, its use for routine treatment of acute diarrheal illness is questionable.