Browsing by Author "Olsen, J.E"

Now showing 1 - 3 of 3

Isolation of vancomycin-resistant Enterococcus from apparently healthy human animal attendants, cattle and cattle wastes in Tanzania
(2018-01) Muhairwa, A.P; Lupindu, A.M; Madoshi, B.P; Mtambo, M.M.A; Olsen, J.E
Aim: The study aimed to isolate and characterize Enterococcus species from apparently healthy waste attendants, cattle and cattle waste in Tanzania. Emphasis was given to antimicrobial resistance and in particular occurrence of vancomycin (VA)-resistant enterococci. Methods and Results: Faecal samples were collected from healthy cattle, cattle waste attendants and cattle house wastes, and isolation of Enterococcus species was performed using Slanetz Bartley agar. Isolates were characterized with regard to species, antimicrobial susceptibility and presence of VA resistance genes. Enterococcus faecalis was the most prevalent species from all sources of isolation (43 5%), followed by Enterococcus faecium (38 4%). Isolates of E. faecium showed a higher number of phenotypic antimicrobial resistance than isolates of E. faecalis. Fifty-eight isolates, which showed resistance or intermediate resistance to VA by disc diffusion test, were analysed for VA- resistant Enterococcus (VRE) by PCR. The vanA gene was detected in 14 isolates of E. faecium and 12 isolates of E. faecalis, while vanB was detected in three isolates. No isolates were found to carry vanC1-gene. Conclusion: VRE was detected in both human and cattle samples, despite no known use of antimicrobial agents that can select for VRE in livestock in Tanzania. Enterococcus faecalis was the most commonly isolated species from cattle and humans. Significance and Impact of the Study: The study provides information on the prevalence of VRE in human and nonhuman samples in Tanzania calling for further studies on the origin of VRE in such isolates, since no selection mechanism in Tanzania are known.
Molecular epidemiology of Salmonella gallinarum in chickens in Tanzania
(2010-06-17) Mdegela, R. H.; Yongolo, M; Minga, U.M; Olsen, J.E
A molecular epidemiological investigation of Salmonella gallinarum infection in scavenging local chickens and commercial layers in Tanzania was conducted between August 1997 and April 1998. A total of 1152 chickens were randomly selected from 10 villages and seven commercial farms. For serological and cultural prevalence studies, 1152 blood samples and 912 cloacal swabs were collected. In scavenging local chickens, the individual serological and cultural prevalences were 6.3 and 0%, while the prevalences were significantly higher in commercial layers at 18.4 and 2.6% (P < 0.001), respectively. The risk of infection in flocks of scavenging local chickens that had contact with commercial chickens was six times greater than the risk of infection in flocks of scavenging local chickens that had no contact with commercial chickens. Thirty-four S. gallinarum isolated from commercial chickens in this study, together with 29 Tanzanian historical isolates, were characterized using plasmid profiling and ribotyping. Fifty-one isolates contained both 85 and 2.5 kb plasmids, five isolates contained only one plasmid of 85 kb, and seven isolates had no plasmids. Ribotyping using HindIII restriction endonuclease demonstrated seven different ribotypes. Forty-seven isolates had similar results in both typing systems, suggesting they belonged to one clone. It is concluded that S. gallinarum infection in chickens in Tanzania is more prevalent in commercial layers than in scavenging local chickens. One strain of S. gallinarum from chickens first isolated in a Dar es Salaam hatchery was found to be common throughout the country.
Rural poultry in Tanzania; the untapped potential: a short review
(Proceedings of the 1 st University Wide Scientific Conference, 5t h – 7th April, 2000: Volume 4., 2000-04) Minga, U.M; Yongolo, M.G.S; Lawrence, P; Mwalusanya, N.A; Katule, A; Gwakisa, P.S; Mlozi, M.R.S; Olsen, J.E
This is a short review of the studies made on the scavenging local chicken (SLC) in Tanzania. According to recent estimates, there are approximately 28 million poultry in Tanzania and of these, 27 million are chickens, mainly scavenging local chickens (93.3%) and relatively few commercial broilers and layers (6.7%). The other poultry are Ducks and geese (743,500), turkeys (63,400) and Guinea fowl (38,000). Poultry are kept by about 2.5 million households out of 3.7 million agricultural households, compared to 1.0 million households which keep cattle. This large potential of the rural chicken is yet to be fully tapped. The main constraints to realising the potential are poor husbandry, low genetic potential and disease and, of the diseases, Newcastle disease has been singled out to be the most important. Due to those factors, the productivity indices are low and the off take rate is also low. Thus the average egg production per hen per year is about 70 whereas the average adult weight of hens is 1.54kg and for cocks is 1.85kg. However recent studies have revealed that the scavenging local chickens (SLC) differ phenotypically and that so far five ecotypes have been identified in Tanzania, namely Kuchi (originating from Mwanza), Singamagazi (Tabora), Mbeya (Mbeya), Morogoro medium (Morogoro), Ching’wekwe or Morogoro Short (Morogoro). The ecotypes differ in their productivity indeces. The average adult body weights of cocks and hens of the ecotypes are 2.71kg and 1.83; 2.92 kg and 2.02 kg; 1.62 kg and 1.40 kg, 1.85 and 1.11 kg, 2.10 kg and 1.44 kg respectively. It is suggested that the economic and nutritional potential of the SLC can be fully realised if husbandry is improved, selective breeding is practised and diseases control through vaccination of especially Newcastle disease is regularly conducted. It is estimated that the chicken industry is worth 40.5 billion shillings or about US dollars 50.6 million and that with the ideal off-take rate, the industry can generate over 155.1 billion shillings or US dollars 193.9 million through the sale of about 103.4 million surplus growers alone. The way forward is proposed.