Trimethoprim-sulfamethoxazole (CTX) has been recommended by the World Health Organization as a prophylactic drug for HIV/AIDS-patients against opportunistic infections. However, daily use of CTX may reduce its efficacy to enteric Escherichia coli, thus increasing the burden of CTX-resistant pathogens. Resistance of enteric pathogens to CTX may affect empiric treatment approaches especially in HIV/AIDS patients. We prospectively investigated incidences of fecal E. coli resistance to CTX in 188 HIV-infected patients of 15-72 years of age, and determined changes in susceptibility patterns. The study was conducted in Dar es Salaam, Tanzania involving collection of stool specimens from HIV-patients prior and after initiation of CTX prophylaxis. Specimens were collected on 1 st , 4 th , and 24 th weeks upon commencing CTX prophylaxis. Susceptibility profiling of E. coli and other enteric bacteria to CTX and other widely used antibiotics were done using Kirby-Bauer disk diffusion method. On the first visit, 143(76.1%) enteric bacteria were isolated. Of those, 123(86%) were E. coli. About 98.6% were resistant to CTX. On the second visit, 103(54.2%) bacteria were isolated; of those, 100(98.4%) of them exhibited resistance to CTX. On the third visit, 64(34%) out of 188 patients had significant enteric bacteria, and of those 63 (98.4%) were resistant to CTX. About 53.2% of bacterial isolates were resistant to ciprofloxacin and ampicillin. Majority (95.2%) of the patients had initiated CTX prophylaxis prior to testing at the care and treatment clinics. About 32% of the patients reported to have skipped some doses of CTX prophylaxis. Non-adherence to CTX prophylaxis and self-medication among patients may have attributed to the observed high prevalence rate of E. coli resistance to CTX and other commonly used antibiotics. For better understanding of the observed pattern of bacterial resistance to CTX, phenotypic and/or genotypic characterization of the isolated bacteria needs to be conducted. the need to use antibiotics more cautiously. Unless we act now, we face a future of untreatable bacterial infections. Immune-compromised patients such as people living with HIV/AIDS (PLHA) are the most likely to be affected by resistant bacterial and fungal infections. As in many other developing countries, conditions that may foster antibiotic resistance in Tanzania differ from developed countries, and so resistance prevalence. Faecal pollution and other traits of overcrowded cities with poor sanitary conditions might create ideal settings for selecting, exchanging and maintaining resistance traits. In addition, medical abuse of antibiotics, along with low-quality drugs are also prevalent [13]. Self-medication, a common yet unmeasured practice among Tanzanian population, may also contribute to increased resistance rates [15]. Therefore, knowledge of antimicrobial resistance trends among bacterial isolates is essential in order to provide clinically appropriate and cost effective therapy. Microbial infections such as NTS and Salmonella fo...
