Abstract:
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.
