Prevalence of antimicrobial resistance and characterization of fecal indicator bacteria and staphylococcus aureus from farm animals, wildlife, pets and humans in Tanzania

This thesis is prepared according to “Publishable manuscript” format of the Sokoine University of Agriculture. It is divided into four sections; the first section presents introduction, problem statement, objectives, rationale of the study and hypothesis while the second section is a review of literature in relation to the work performed. The third section contains four manuscripts which cover the research work done, whereas the last section details overall conclusions of the study. The first manuscript is about the findings on the awareness of risks associated with antimicrobials use and practices that contribute to selection for antimicrobial resistance in livestock. The second and the third Manuscripts present the prevalence of antimicrobial resistance in indicator bacteria namely S. aureus from nostrils, E. coli and Enterococci spp from faecal samples obtained from livestock, dogs and contact human beings, and the last manuscript presents findings on antimicrobial resistance in faecal indicator organisms from buffalo, wildebeest, zebra and cattle grazing with wild ungulates. The studies involved testing resistance using antibiotic discs, inclusion of antibiotics in the media and evaluating bacterial DNA for resistance genes against commonly used antibiotics in livestock. In response to the first objective presented in manuscript 1, awareness of human health risks due to use of antibiotics among livestock keepers and factors that contribute to selection of antibiotic resistance bacteria within livestock in Tanzania were determined. Looking at awareness on health risks among the livestock keepers surveyed, one hundred and sixty randomly selected Tanzanian small-scale livestock keepers were involved in the questionnaire-based survey. The results showed that 30% of the respondents were not aware of the concept of antibiotic resistance whereas 52% were not aware of the types of diseases that can be treated with antibiotics, 22% did not know the essence of withdrawal period after treatment of animals with antibiotics and 40% did not know if antibiotics used in livestock pose risk to human health. Side effects of antibiotics to human beings known by the respondents include drug resistance, allergy, poisoning, skin rashes and cancer. Further, it was found that the most commonly used antibiotics were oxytetracyline (TE) (62.9 %) followed by sulphadimidine/ trimethoprim / (STX) (23.2 %), penicillin-streptomycin (13.4 %) and gentamycin (CN) (0.5 %).Only 54% of the respondents obtained their antibiotics through prescription by veterinarians. Potential risk factors were identified to be the sources of development of antimicrobials resistance. These included livestock management systems, antibiotics handling and types of antibiotics used in the study areas. Points of selling antibiotics and their prescriptions were found to be handled by agriculture and veterinary input shops, veterinarians, livestock markets and exhibition areas. The study concludes that there is a gross lack of awareness on health threats associated with antibiotics resistance among the farming communities thus posing serious public health threats in Tanzania.DANID