Department of Veterinary Medicine and Public Health

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Acceptability of wastewater resource and its impact on crop production in Tanzania: the case of Dodoma, Morogoro and Mvomero wastewater stabilization ponds
(2013) Kilobe, B. M; Mdegela, R. H.; Mtambo, M.M.A
The study was carried out to assess the views of urban farmers in relation to acceptability of wastewater resource in agriculture and examine its impact for crop production. A total of 200 respondents were involved in this study. The study found that 90% of the 112 households using wastewater and 85% of the 88 households not using the resource indicated effluents from WSPs as main and reliable source of water for irrigation. Wastewater utilization in agriculture was accepted by 97.3% of farmers using wastewater and 64.8% of farmers not using it and the difference was significant (p<0.01). The study found that on average farmers utilizing wastewater produced 4.5 bags of rice per acre more than farmers not utilizing wastewater and the difference was significant (p<0.05). In conclusion, wastewater utilization in agriculture was accepted by both groups of farmers engaging in agriculture in urban and peri-urban areas and that high crop yield was realized by farmers utilizing wastewater in agriculture . Since some respondents indicated that the resource may have health effects to farmers and consumers of the produce, it is recommended that, more research on microbial analysis be carried out to establish evidence of health effects associated with the use of wastewater in agriculture from infectious agents
Aflatoxin contamination of marketed spices in Tanzania: a case study of Dar es salaam
(Sokoine University of Agriculture, 2018) Fundikira, S. S.
Aflatoxin contamination of spices, namely ginger, cinnamon, cardamom and cloves marketed in three districts of Ilala, Temeke and Kinondoni in Dar es Salaam region, Tanzania was investigated in the year 2017/18. Aflatoxin B1, B2, G1 and G2 and total aflatoxins were determined in 120 spice samples using immuno-affinity high performance liquid chromatography and post column derivatization. Fifty eight percent of the spice samples were contaminated and the mean total aflatoxins level in ginger, cinnamon, cloves and cardamom was 2.67, 2.88, 2.79 and 2.26 (μg/kg), respectively. Aflatoxin B1 level in ginger, cinnamon, cloves and cardamom was 0.65, 0.41, 0.40 and 1.09 (μg/kg), respectively. About 10% of the contaminated spices had total aflatoxins above the acceptable EU regulatory level of 10μg/kg and the highest level was 11.9μg/kg, whereas 20.4% of contaminated spices contained aflatoxin B1 above the acceptable EU regulatory level of 5μg/kg, of which the highest level was 11.23μg/kg. Thirty respondents, from whom the spice samples were collected, were interviewed through a structured questionnaire to assess their awareness on aflatoxins, handling and storage practices of spices. The majority (96.7%) of the participants had neither heard of aflatoxins nor attended any training related to food handling and storage. None of the participants were aware of the ill-health effects of aflatoxins on humans and animals. The odds of respondents with age between 36 and 44 years (OR = 0.326, 95%CI = 0.113 - 0.940, p = 0.038) was significantly associated with aflatoxin contamination of spices collected compared to other age groups. The odds of spices that were purchased from farmers (OR = 0.178, 95% CI = 0.061 - 0.525, p = 0.002) was also significantly associated with aflatoxin contamination of spices compared to other sources. The odds of storing spices for length of more than 14 days (OR = 3.608, 95%CI = 1.099 - 11.845, p = 0.034) was significantly associated with aflatoxin contamination of spices as compared to storing for shorter periods of time. It was concluded that the prevalence of aflatoxin contamination of the spices was high and the level of awareness on aflatoxins was very low in the study population. Hence, there was need for raising awareness and sensitization of stakeholders involved in spices and spice value chain.
Aflatoxins contamination in spices and associated predisposing factors in Morogoro region, Tanzania
(Sokoine University of Agriculture, 2021) Peter, Lilian G.
Aflatoxins contamination in spices can result to serious health impact to consumers. Little information is available about levels of aflatoxins in spices traded in Tanzania. This study investigated awareness on aflatoxins and handling, storage and packaging practices of spices in relation to aflatoxins contamination as well as levels in black pepper, cinnamon, cloves and turmeric in Morogoro, Tanzania. A total of 120 spices samples were collected from 52 spice dealers among spice traders and analyzed for aflatoxins B 1 , B 2 , G 1 , G 2 , total aflatoxins and moisture content. Aflatoxins were analyzed using HPLC with fluorescence detector. The association of aflatoxins contamination in spices with traders’ demographic and sociological characteristics, awareness and handling practices were determined using a questionnaire. Results showed that 24.2% of the spice samples were contaminated with aflatoxins; whereby 11.7% was with aflatoxin B 1 (AFB 1) . Spices from Morogoro rural had high rate of aflatoxin contamination (33.3%) compared to those from Morogoro municipality (15.0%). Turmeric had the lowest contamination rate of AFB 1 (0.0%) and total aflatoxins (3.3%) while cloves had highest contamination with 20% and 50.0% for AFB 1 and total aflatoxins, respectively. Lowest aflatoxins contamination was 0.2 μg/kg in cloves while the highest was 164.9 μg/kg in black pepper. Percentage of spice samples exceeded European Union regulatory limit was nine point two percent for AFB 1 and 13.3% for total aflatoxins. Majority (96.2%) of spice traders store their spices and storage time varied from 0 to 100 weeks. Among spice dealers who were doing storage, 34.9% of their samples had aflatoxin contaminations. Half of the respondents who were doing sorting, 65.4% of them discarded the rejected spices. Aflatoxin contaminations for the samples from respondent who were not doing sorting was 61.5%. Occurrence of aflatoxins in spices was associated (p>0.05) with sorting, criteria for sorting, handling of rejected spices, storage practices, awareness on causes of spoilage and awareness on aflatoxins in food. It is concluded that spices in the study area were highly contaminated with aflatoxins some of them beyond the maximum limit set by EU. The study revealed limited awareness and knowledge on aflatoxins contamination in spices among spice traders. Awareness creation on aflatoxins contamination in spices and preventive strategies need to be considered to reduce aflatoxins contamination to safeguard health of spices consumers in Morogoro, Tanzania.
African 2, a clonal complex of mycobacterium bovis epidemiologically important in East Africa
(American Society for Microbiology, 2011) Stefan, Berg, M; Borna, Müller; Elena, Hailu; Benon, Asiimwe; Kristin, Kremer; James, Dale M; Beatrice, Boniotti; Sabrina, Rodriguez; Markus, Hilty; Leen, Rigouts; Rebuma, Firdessa; Adelina, Machado; Custodia, Mucavele; Bongo, Nare R. N; Bruchfeld, Judith; Boschiroli, Laura; Müller, Annélle; Sahraoui, Naima; Pacciarini, Maria; Cadmus, Smeoni; Joloba, Moses; Joloba, Moses; Soolingen, Dick v; Michel, Anita L.; Djønne, Berit; Aranaz, Alicia; Zinsstag, Jakob; Portaels, Françoise; Kazwala, Rudovick; Källenius, Gunilla; Hewinson, Glyn; Aseffa, Abraham; Gordon, Stephen V.; Smith, Noel H.; Garcia-Pelayo, M. Carmen
We have identified a clonal complex of Mycobacterium bovis isolated at high frequency from cattle in Uganda, Burundi, Tanzania, and Ethiopia. We have named this related group of M. bovis strains the African 2 (Af2) clonal complex of M. bovis. Af2 strains are defined by a specific chromosomal deletion (RDAf2) and can be identified by the absence of spacers 3 to 7 in their spoligotype patterns. Deletion analysis of M. bovis isolates from Algeria, Mali, Chad, Nigeria, Cameroon, South Africa, and Mozambique did not identify any strains of the Af2 clonal complex, suggesting that this clonal complex of M. bovis is localized in East Africa. The specific spoligotype pattern of the Af2 clonal complex was rarely identified among isolates from outside Africa, and the few isolates that were found and tested were intact at the RDAf2 locus. We conclude that the Af2 clonal complex is localized to cattle in East Africa. We found that …
Alcelaphine herpesvirus-1 (Malignant Catarrhal Fever Virus) in wildebeest placenta: Genetic variation of ORF50 and A9.5 alleles
(PLoS ONE, 2015-05-13) Lankester, F.; Lugelo, A.; Mnyambwa, N.; Ndabigaye, A.; Keyyu, J.; Kazwala, R. R.; Grant, D. M.; Relf, V.; Haig, D. M.; Cleaveland, S.; Russell, G. C.
Alcelaphine herpesvirus–1 (AlHV-1), a causative agent of malignant catarrhal fever in cattle, was detected in wildebeest (Connochaetes taurinus) placenta tissue for the first time. Although viral load was low, the finding of viral DNA in over 50%of 94 samples tested lends support to the possibility that placental tissue could play a role in disease transmission and that wildebeest calves are infected in utero. Two viral loci were sequenced to examine variation among virus samples obtained from wildebeest and cattle: the ORF50 gene, encoding the lytic cycle transactivator protein, and the A9.5 gene, encoding a novel polymorphic viral glycoprotein. ORF50 was well conserved with six newly discovered alleles differing at only one or two base positions. In contrast, while only three new A9.5 alleles were discovered, these differed by up to 13% at the nucleotide level and up to 20% at the amino acid level. Structural homology searching performed with the additional A9.5 sequences determined in this study adds power to recent analysis identifying the four-helix bundle cytokine interleukin-4 (IL4) as themajor homologue. The majority of MCF virus samples obtained from Tanzanian cattle and wildebeest encoded A9.5 polypeptides identical to the previously characterized A9.5 allele present in the laboratory maintained AlHV-1 C500 strain. This supports the view that AlHV-1 C500 is suitable for the development of a vaccine for wildebeest-associated MCF.
Analysis of host genetic factors influencing African trypanosome species infection in a cohort of Tanzanian Bos indicus cattle
(Elsevier, 2011) Karimuribo, Esron D; Morrison, Liam J.; Black, Alana; Turner, Michael R.; Kambarage, Dominic M.; Ballingall, Keith T.
Trypanosomosis caused by infection with protozoan parasites of the genus Trypanosoma is a major health constraint to cattle production in many African countries. One hundred and seventy one Bos indicus cattle from traditional pastoral Maasai (87) and more intensively managed Boran (84) animals in Tanzania were screened by PCR for the presence of African animal trypanosomes (Trypanosoma congolense, Trypanosoma vivax and Trypanosoma bru- cei), using blood samples archived on FTA cards. All cattle screened for trypanosomes were also genotyped at the highly polymorphic major histocompatibility complex (MHC) class II DRB3 locus to investigate possible associations between host MHC and trypanosome infec- tion. Overall, 23.4% of the 171 cattle tested positive for at least one of the three trypanosome species. The prevalence of individual trypanosome species was 8.8% (T. congolense), 4.7% (T. vivax) and 15.8% (T. brucei). The high prevalence of T. brucei compared with T. congolense and T. vivax was unexpected as this species has previously been considered to be of lesser impor- tance in terms of African bovine trypanosomosis. Significantly higher numbers of Maasai cattle were infected with T. brucei (23.0%, p = 0.009) and T. congolense (13.8%, p = 0.019) com- pared with Boran cattle (8.3% and 3.6%, respectively). Analysis of BoLA-DRB3 diversity in this cohort identified extensive allelic diversity. Thirty-three BoLA-DRB3 PCR-RFLP defined alle- les were identified. One allele (DRB3*15) was significantly associated with an increased risk (odds ratio, OR = 2.71, p = 0.034) of T. brucei infection and three alleles (DRB3*35, *16 and *23) were associated with increased risk of T. congolense infection. While further work is required to dissect the role of these alleles in susceptibility to T. brucei and T. congolense infections, this study demonstrates the utility of FTA archived blood samples in combined molecular analyses of both host and pathogen.
Analysis of mutation rate of 17 y-chromosome short tandem repeats loci using Tanzanian father-son paired samples
(Sokoine University of Agriculture, 2015) Charles, Fidelis
In the present study, 100 unrelated father-son buccal swab sample pairs from consented Tanzanian population were examined to establish mutation rates using 17 Y-STRs loci DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385a, DYS385b, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, and Y- GATA-H4 of the AmpFlSTRYfiler kit used in forensics and paternity testing. Prior to 17 Y-STRs analysis, father-son pair biological relationships were confirmed using 15 autosomal STRs markers and found to be paternally related. A total of four single repeat mutational events were observed between father and sons. Two mutations resulted in the gain of a repeat and the other two resulted in a loss of a repeat in the son. All observed mutations occurred at tetranucleotide loci DYS389II, DYS385a and DYS385b. The locus specific mutation rate varied between 0 and 1.176 x10 -3 and the average mutation rate of 17 Y-STRs loci in the present study was 2.353x10 -3 (6.41x10 -4 - 6.013x10 -3 ) at 95% CI. Furthermore the mean fathers’ age with at least one mutation at son’s birth was 32 years with standard error 2.387 while the average age of all fathers without mutation in a sampled population at son’s birth was 26.781 years with standard error 0.609. The results shows that fathers’ age at son’s birth may have confounding effect on Y-STRs mutation rate analysis though this age difference is statistically not significant using un paired samples t-test (p = 0.05). As a consequence of observed mutation rates in this study, the precise and reliable understanding of mutation rate at Y chromosome short tandem repeats loci is necessary for a correct evaluation and interpretation of DNA typing results in forensics and paternity testing involving males. The criterion for exclusion in paternity testing should be defined, so that an exclusion from paternity has to be based on exclusion constellations at the minimum of two 17 Y-STRs loci.
Anthrax outbreaks in the humans - livestock and wildlife interface areas of Northern Tanzania: A retrospective record review 2006–2016
(BMC, 2018-02-15) Mwakapeje, E. R.; Høgset, S.; Fyumagwa, R.; Nonga, H. E.; Mdegela, R. H.; Skjerve, E.
Background: Anthrax outbreaks in Tanzania have been reported from the human, livestock and wildlife sectors over several years, and is among the notifiable diseases. Despite frequent anthrax outbreaks, there is no comprehensive dataset indicating the magnitude and distribution of the disease in susceptible species. This study is a retrospective review of anthrax outbreaks from the human, livestock, and wildlife surveillance systems from 2006 to 2016. The objectives were to identify hotspot districts, describe anthrax epidemiology in the hotspot areas, evaluate the efficiency of the anthrax response systems and identify potential areas for further observational studies. Methods: We prepared a spreadsheet template for a retrospective comprehensive record review at different surveillance levels in Tanzania. We captured data elements including demographic characteristics of different species, the name of health facility, and date of anthrax diagnosis. Also, we collected data on the date of specimen collection, species screened, type of laboratory test, laboratory results and the outcome recorded at the end of treatment in humans. After establishing the database, we produced maps in Quantum GIS software and transferred cleaned data to Stata software for supportive statistical analysis. Results: Anthrax reported incidences over 4 years in humans were much higher in the Arusha region (7.88/100,000) followed by Kilimanjaro region (6.64/100,000) than other regions of Tanzania Mainland. The health facility based review from hotspot districts in parts of Arusha and Kilimanjaro regions from 2006 to 2016, identified 330 human anthrax cases from the selected health facilities in the two regions. Out of 161 livestock and 57 wildlife specimen tested, 103 and 18 respectively, were positive for anthrax. Conclusion: This study revealed that there is gross under-reporting in the existing surveillance systems which is an obstacle for estimating a true burden of anthrax in the hotspot districts. Repeated occurrences of anthrax in livestock, wildlife and humans in the same locations at the same time calls for the need to strengthen links and promote inter–disciplinary and multi-sectoral collaboration to enhance prevention and control measures under a One Health approach.
Anti-trypanosomal and cytotoxic effects of extracts from commiphora swynnertonii burtt 1935
(Sokoine University of Agriculture, 2018) Nagagi, Yakob Petro
Application of trypanocides both curatively and prophylactically is a key component of beset with many problems including drug toxicity and treatment failure due to widespread resistance ofthe parasites. Given little progress in vaccine development, there is a pressing need for discovery of new alternative trypanocidal molecules that can further be developed into trypanocidal drugs. Plants are one such source from which alternative trypanocidal molecules could be obtained. Commiphora swynnertonii is a member of the family Burseraceae which is reported to possess a number of compounds active against protozoa. This thesis provides Commiphora swynnertonii extracts, and its potential as a source of lead molecules for development of alternative trypanocidal drug for trypanosomosis control. The main results are presented in two published papers and one submitted manuscript. The first paper presents the in vitro trypanocidal activity of Commiphora swynnertonii extracts on Trypanosoma congolense in which, the motility of T. congolense was evaluated after incubation for 20 minutes with ethanolic stem-bark and resin extracts at concentration of2 mg/ml and 4 mg/ml. In the second study, T. congolense was incubated with the extracts at concentrations of 0.4 mg/ml and 2 mg/ml for 36 - 56 min after which 0.08 ml of the aliquots were inoculated intraperitoneally into mice to assess infectivity. In both studies, negative (phosphate buffered saline with glucose without the extract) and positive (diminazene diaceturate) controls were used. The findings showed that C. swynnertonii ethanolic stem bark extract caused complete cessation of T. congolense motility in 30 minutes at the concentration of 4 mg/ml. Resin extract had a delayed effect on the cessation of T. congolense motility observed after 90 and 100 minutes of incubation at concentrations of 4 mg/ml and 2 mg/ml respectively. The drug incubation showed that ethanolic stem bark extract reduced significantly (P=0.000) the infectivity of T. congolense at concentration of 2 mg/ml compared to negative control and was not significantly (P=0.S97) different from the positive control. It was concluded that, C. swynnertonii ethanolic stem bark extract possesses in vitro trypanocidal activity. The second paper presents the results ofin vivo activity of C. swynnertonii ethanolic stem bark extract on T. congolense parasitaemia and its effect on immunological components in mice. Groups of mice infected with T. congolense were treated with the stem bark extracts at 1000 mg/kg, 1500 mg/kg and 2000 mg/kg, twice a day in one set and thrice a day in another setting for three days consecutively, and parasitaemia monitored. In the other setting, uninfected mice randomized in five groups were treated with the extract that was categorized as thorough mixed extract (TME) and supernatant extract (SE)) each at 500 mg/kg and 1500 mg/kg, in 8 hourly intervals respectively for three days consecutively. The groups that received the extracts (1000 mg/kg and 2000 mg/kg) at eight hourly intervals had drastically reduced parasitaemia (P<0.05). It was concluded that C. swynnertonii ethanolic stem bark extract possesses in vivo trypanocidal activity. On the other hand, SE at the dose of 1500 mg/kg significantly (P<0.05) reduced the percentage of peripheral lymphocytes. Both doses (500 mg/kg and 1500 mg/kg) of TME significantly (P<0.05) reduced lymphocytes percent while neutrophils and monocytes percent increased significantly (P<0.05). Histopathology of the spleen in the mice treated with 1500 mg/kg of SE and TME showed apoptosis of lymphocytes around the marginal zone and lymphoid follicles. Hence, it was concluded that C. swynnertonii ethanolic stem bark extract within anti-trypanosomal therapeutic dose range possesses cytotoxic effect on lymphocytes. The submitted manuscript provides the results on anti-trypanosomal activities of fractions and sub-fractions of C. swynnertonii ethanolic stem bark extract against T. congolense. Negative (phosphate buffered saline with glucose without the extract) and positive (diminazene diaceturate) controls were used. In addition, chromatographic techniques were employed to determine bioactive molecules in the sub-fractions. The findings indicated that anti-trypanosomal activity in the fractions of aqueous, dichloromethane and petroleum ether were decreasing in that order. In this study, four terpenoids (bomeol, geranylgeraniol, coronopilin and 4,8,13-duvatriene-l,3-diol) were detected and were considered to be likely responsible for trypanocidal activity of Commiphora swynnertonii ethanolic stem bark extract. Further studies to evaluate the in vivo trypanocidal potential are recommended. As a general conclusion, this study has shown that C. swynnertonii stem bark extract possesses in vitro and in vivo trypanocidal activity. The in vivo trypanocidal activity is probably affected by cytotoxic effect on lymphocytes at the therapeutic dosage. It was further found that bomeol, geranylgeraniol, coronopilin and 4,8,13-duvatriene-l,3-diol could be responsible for observed trypanocidal efficacy of C. swynnertonii stem bark extract. Further studies to determine their therapeutic trypanocidal potentials are recommended
Antibiotic resistance and virulence profiles of staphylococcus aureus and escherichia coli from rodents, humans and chicken coexisting in Karatu, Tanzania.
(Sokoine University of Agriculture, 2022) Sonola, V. S.
Antimicrobial resistance (AMR) is a rapidly growing multifaceted problem which threatens global security, public health and the economy. Currently, about 700 000 humans worldwide lose lives annually due to AMR infections that are difficult to treat which are also associated with higher health care costs, elongated time spent in hospitals and increased animal production costs. This study was conducted in Karatu district, northern Tanzania, to investigate antibiotic resistance and virulence profiles of Staphylococcus aureus and Escherichia coli isolated from humans, rodents, chicken and soil in households. Interaction of rodents with humans and livestock in households’ environment has frequently been reported in Karatu, facilitating wide spread of resistant bacterial infections among different hosts in the community. The main objective of this study was to determine the antibiotic resistance and virulence profiles of Staphylococcus aureus and Escherichia coli isolated from rodents, chicken, humans and their surrounding environment in Karatu District. S. aureus were isolated from 284 human nasal swabs, 101 rodents’ deep pharyngeal swabs, 286 chicken cloaca swabs and 285 household soil samples. Specimens were plated into Mannitol Salt Agar (Oxoid, Basingstoke, UK) and incubated aerobically at 37 °C for 24 h. Presumptive colonies of S. aureus were subjected to Gram staining, catalase, deoxyribonuclease (DNAse) and coagulase tests for identification. Antibiotic susceptibility testing (AST) was performed by using Kirby-Bauer disc diffusion method on Mueller-Hinton Agar (Oxoid, Basingstoke, UK). The antibiotics tested were tetracycline (30 μg), erythromycin (15 μg), gentamicin (10 μg), ciprofloxacin (5 μg), iii clindamycin (2 μg) and amoxicillin-clavulanate (20 μg/10 μg). S. aureus strain American Type Culture Collection (ATCC) 25923 was used as a standard organism. Results were interpreted according to Clinical and Laboratory Standard Institute (CLSI) guideline of 2020. The samples used for E. coli isolation included 288 chicken cloaca swabs, 281 human stool, 101 rodents’ intestinal contents and 290 household soils. The specimens were plated onto MacConkey agar (Oxoid Ltd., Detroid, Michigan, USA) and incubated aerobically at 37 ºC for 24 h. Presumptive E. coli colonies were subjected to motility test and later indole, methyl red, Voges-Proskauer and citrate utilization (IMViC) tests for identification. E. coli strain ATCC 29522 was used as a reference organism. AST was performed by using Kirby-Bauer disc diffusion method on Mueller-Hinton Agar plates (Oxoid, Basingstoke, UK). The antibiotics tested were; tetracycline (30 μg), imipenem (10 μg), gentamicin (10 μg), ciprofloxacin (5 μg) cefotaxime (30 μg) and amoxicillin clavulanate (20 μg/10 μg). The results were interpreted by using CLSI (2020) guideline. Results of this investigation revealed high frequencies of isolation for S. aureus and E. coli in rodents, humans, and chicken and soil samples. For S. aureus, the isolation frequencies were 52.1%, 66.5%, 74.3% and 24.5% in samples from chicken, human, rodent and soil, respectively. The isolation frequencies of E. coli from chicken, humans, rodents and soil were 81.6 %, 86.5 %, 80.2 % and 31.0 %, respectively. Based on AST phenotypic results, S. aureus isolates displayed resistance to clindamycin (51%), erythromycin (50.9%) and tetracycline (62.5%) while E. coli isolates showed high resistance against tetracycline (73.7%), imipenem (79.8%) and cefotaxime (79.7%). MDR E. coli (n=50) and S. aureus (n=57) isolates that exhibited high levels of phenotypic resistance to various classes of antibiotics were subjected to molecular analysis using iv multiplex polymerase chain reaction (PCR) technique to detect presence of antibiotic resistance (ARGs) and virulence genes (VGs). ARGs detected in MDR E. coli were; blaTEM (46%), blaCTX-M (26%), blaSHV (22%), tetA (46%), tetB (14%), qnrA (24%), qnrB (8%), blaOXA-48 (12%) and blaKPC (6%) while VGs detected included; ompA (72%), traT (26%), east (18%), bfp (10%), eae (2%) and stx-1 (4%). For MDR S. aureus, ARGs were; tetK (31.6%), tetL (8.9%), ermC (1.8%) and mecA (28.1%) while VGs detected were; clfB (10.5%), coa (14.0%), clfA (1.8%), hlg (1.8%), ebpS (3.5%), fnbB (3.5%), luk-PV (10.5%) and tst (1.8%). Positive and negative correlations between resistance and virulence genes were observed. For MDR E. coli, positive correlations were found between blaTEM and traT genes (r=0.51) and qnrB and bfp genes (r=0.63), while negative correlations were found between blaOXA-48 and ompA (r= -0.05), blaSHV and traT (r=-0.44) and tetA and east (r=-0.10). For S. aureus, positive correlations were found between resistance (ermC) and clfA (r=0.57), hlg (r=1.00) and clfB (r=0.43), tetK and clfB (r=0.39); tetK and coa (r=0.36). The principal component analysis (PCA) results for S. aureus showed that, resistance genes (tetK and mecA) and virulence determinants (clfB, coa and luk-PV) were common in all sample sources. The PCA also revealed that, MDR E. coli and S. aureus isolates from rodents and chicken had more ARGs and VGs compared to isolates from soil and humans. Besides, MDR E. coli isolates harboured traT, east, eae, stx-1, bfp and ompA genes indicating ability of isolates to cause various infections. Based on findings, this study documents high levels of antimicrobial resistance including MDR in E. coli and S. aureus isolated from chicken, humans, rodents and soil samples in Karatu, northern Tanzania. According to PCA results, E. coli isolates from rodents had more ARGs and VGs while for S. aureus these genes were found more in rodents and soil v environment implying that both subjects are potential reservoirs and can be sources of transmission. The increased prevalence of both resistance and virulence genes in the isolates suggests the ability of the pathogens to cause infections that are difficult to treat. Comprehensive one health interventions, are urgently needed and should include improving; i) improving hygiene and control of rodents in household environments. ii) Future studies should base on adequate understanding of the human-livestock environment interphase using well-designed genomic studies such as whole genomic sequencing (WGS) which provides a comprehensive picture on the pattern and magnitude of AMR and virulence genes spread. The advances and accessibility of genomic sequencing and analytical methods are essential in improving our understanding of AMR transmission dynamics at the human-livestock/animal-environment interface. Genomic studies should be coupled with behavioural, epidemiological, clinical and modelling using One Health approaches. This will ensure that the key drivers of resistance and virulence transmission between human-livestock-environment are accurately identified and the most appropriate interventions adopted. It is important to understand the importance of each component of the human-livestock/animal-environment. A One Health approach should be deployed to ensure involvement of relevant multisectoral and multidisciplinary to attain an optimal public health and ensure a safe environment.
Antimicrobial activity study and chemical characterization of pure compounds from synadenium glaucescens pax
(Sokoine University of Agriculture, 2017) Rwegoshora, F.
The modern medicine particularly drugs’ discovery and their development is a result of improvement of the local knowledge of the health practitioners on the medicinal plants and animal products. This study aimed at isolating and testing the bioactive compounds from Synadenium glaucescens collected from Njombe Region; Tanzania. Extraction was done using Soxhlet method while the isolation involved a series of chromatographic techniques. Nuclear magnetic resonance (NMR) technique was used for compound identification. Colour reaction was done using Vanillin reagent. Microdilution and agar well diffusion methods were used to test for antimicrobial activity of the isolates and/or compounds. The crude extracts obtained were 1.99 % and 6.25 % by weight of the pulverized stem wood and the stem bark respectively. The percentage composition of the pure compounds from crude extracts ranged between 0.5 % – 8.25 %. Out of nine isolates (5 from stem bark and 4 from stem wood (coded C1 – C9), two compounds C6 and C9 were identified. All compound isolates were conjugated except C2. The majority of fractional extracts reacted bluish purple with vanillin reagent which implies the characteristics of terpenoids. The NMR data were compared to literature, and indicated compound C6 to be a fatty acid and compound C9 showed to have lupeol acetate backbone based on the 1H and 13C NMR spectroscopic data. All tested isolates were bioactive against the tested standard bacterial and fungal strains at different efficacies. Isolate C7 demonstrated the highest activity of MIC (0.01 mg/ml) against A. baumannii and S. enterica, and the largest zone of inhibition (27 mm) against C. tropicalis. These results are recorded for the first time for this plant and present a good direction towards drugs discovery. Further studies on identification and bioassays of the compounds from stem of S. glaucescens are recommended.
Antimicrobial and phytochemical properties of plant extracts from Sterculia Africana, Acacia Sieberiana and Cassia abbreviata ssp. abbreviata
(Sokoine University of Agriculture, 2017) Kirabo, I.
The study of self-medication in non-human primates sheds new light on the complex interaction of animal, plant and parasite. The main objective of this study was to evaluate the antimicrobial properties and phytochemical profile of crude extracts from Sterculia Africana, Acacia sieberiana and Cassia abbreviata ssp. abbreviata, plants present in the yellow baboon diet in Mikumi National Park, Tanzania. Specifically aimed at assessing antibacterial activity of the crude extracts through in vitro studies using standard strains and to establish the phytochemical profile of the crude extracts using chromatography methods. Minimum Inhibitory Concentration (MIC) technique was employed to assess antibacterial activity whereas Thin layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC) techniques were used to assess the plants’ chemical profile. Acacia sieberiana and Cassia abbreviata ssp. abbreviata showed the lowest MIC values of 0.31mg/ml against the Gram negative strains whereas 0.63 mg/ml was the lowest value against the Gram positive strains used in this study. Total extraction was done by maceration and the highest extraction yields of 9.66% and 6.22% were obtained from the root bark of Cassia abbreviata ssp. abbreviata and the leaves of Acacia sieberiana respectively. Findings from Thin Layer Chromatography (TLC) indicated presence of saturated and unsaturated compounds while colour reactions with Vanillin reagent inferred presence of triterpene group of compounds in the ethanolic crude plant extracts. The chemical profile obtained from the HPLC for the plant extracts was comparable to the one from the TLC profile. Antibacterial studies revealed presence of pharmacological activity in the crude plant extracts suggesting that non–human primates feed on the nutrient poor parts of these plants for self-medication. Chromatography analysis offers a starting point in isolation of pure compounds for the purpose of drug development since these plant extracts exhibit activity against bacteria of medical and veterinary importance.
Antimicrobial resistance in human and animal pathogens in Zambia, Democratic Republic of Congo, Mozambique and Tanzania
(Annals of clinical microbiology and Antimicrobials, 2013-12) Mshana, Stephen E; Matee, Mecky; Rweyemamu, Mark
A review of the published and unpublished literature on bacterial resistance in human and animals was performed. Sixty-eight articles/reports from the Democratic Republic of Congo (DRC), Mozambique, Tanzania and Zambia were reviewed. The majority of these articles were from Tanzania. There is an increasing trend in the incidence of antibiotic resistance; of major concern is the increase in multidrug- resistant Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Vibrio cholera, non-typhoid Salmonella and other pathogens responsible for nosocomial infections. The increase in methicillin- resistant Staphylococcus aureus and extended-spectrum beta-lactamase (ESBL) producers in the countries under review confirms the spread of these clones worldwide. Clinical microbiology services in these countries need to be strengthened in order to allow a coordinated surveillance for antimicrobial resistance and provide data for local treatment guidelines and for national policies to control antimicrobial resistance. While the present study does not provide conclusive evidence to associate the increasing trend in antibiotic resistance in humans with the use of antibiotics in animals, either as feed additives or veterinary prescription, we strongly recommend a one-health approach of systematic surveillance across the public and animal health sectors, as well as the adherence to the FAO (Food and Agriculture Organization)-OIE (World Organization of animal Health) –WHO(World Health Organization) recommendations for non-human antimicrobial usage.
Antimicrobial usage in cattle and poultry production in Dar es Salaam, Tanzania: pattern and quantity
(BMC Veterinary Research, 2022) Azabo Rogers; Mshana Stephen; Matee Mecky; Kimera Sharadhuli I.
Background: Antimicrobials are extensively used in cattle and poultry production in Tanzania. However, there is dearth of information on its quantitative use. A questionnaire-based cross-sectional study was conducted from August to September 2019 in randomly selected poultry and small-scale dairy farms, in three districts of Dar es Salaam City eastern, Tanzania, to assess the practice and quantify antimicrobial use. Descriptive and statistical analyses were performed at a confidence interval of 95%. The ratio of Used Daily Dose (UDD) and Defined Daily Dose (DDD) were used to determine whether the antimicrobial was overdosed or under dosed. Results: A total of 51 poultry and 65 small-scale dairy farms were involved in the study. The route of antimicro- bial administration was 98% orally via drinking water and 2% in feeds for poultry and for small-scale dairy farms, all through parenteral route. Seventeen types of antimicrobials comprising seven classes were recorded in poultry farms while nine belonging to six classes in the small dairy farms. Majority of the farms (poultry, 87.7% and small scale dairy, 84.3%) used antimicrobials for therapeutic purposes. About 41% of the poultry and one third (34%) of the dairy farm- ers’ were not compliant to the drug withdrawal periods. Beta-lactams, fluoroquinolones, sulphonamides, tetracyclines and macrolides were the commonly used antimicrobials on these farms. In the poultry farms both those with records and those which relied on recall, antimicrobials were overdosed whereas in the small dairy farms, sulfadimidine, oxytetracycline and neomycin were within the appropriate dosing range (0.8–1.2). The majority (58.6%) of farmers had adequate level of practices (favorable) regarding antimicrobial use in cattle and poultry production. This was associ- ated with the age and level of education of the cattle and poultry farmers. Conclusion: The study revealed a widespread misuse of antimicrobials of different types and classes in both poultry and small-scale dairy farming in Dar es Salaam, Tanzania. This result gives insight into the antimicrobial use practices and its quantification. The information obtained can guide and promote prudent use of antimicrobials among the farmers by developing mitigate strategies that reduce antimicrobial resistance risk potentials.
Antimicrobial use and resistance in food- producing animals and the environment: an African perspective
(BMC, 2020-05) Kimera, Zuhura I; Mshana, Stephen E; Rweyemamu, Mark M; Mboera, Leonard E. G; Matee, Mecky I. N
The overuse of antimicrobials in food animals and the subsequent contamination of the environment have been associated with development and spread of antimicrobial resistance. This review presents information on antimicrobial use, resistance and status of surveillance systems in food animals and the environment in Africa.
Antimicrobial use, prevalence of extended spectrum beta-lactamase producing escherichia coli and economic effects on cattle and poultry in Dar es salaam Tanzania
(SOKOINE UNIVERSITY OF AGRICULTURE, 2023) Azabo R.R
Antimicrobial usage (AMU) in livestock production provides a basis for improving animal health and productivity. However, it is evident that the over-dependence of animal production on antimicrobial agents is one of the major factors driving the emergence of antimicrobial resistance (AMR) in bacteria that can be transmitted via the food chain or environment to humans. This thesis aims to assess antimicrobial use in cattle and poultry production in relation to resistance in Extended Spectrum Beta-Lactamase (ESBL) producing Escherichia coli (E. coli) and also gain insight into economic effects (cost and benefit) of antimicrobial use reduction in animal production inIlala, Kinondoni and Ubungo districts which form part of the Dar es Salaam region, Tanzania with the following objectives.(i) To conduct a systematic review on the methods and metrics used to quantify and assess MU in cattle and poultry production in Sub-Saharan Africa, (ii) To determine the quantity, quality and pattern of antimicrobial use in cattle and poultry production in Dar es Salaam, Tanzania, (iii) To assess antimicrobial consumption in food-producing animals in Dar es Salaam, Tanzania, (iv) To determine the prevalence and antimicrobial resistance pattern of ESBL producing E.coli isolates from cattle and poultry production, and (v) To estimate the economic effects (costs and benefits) of antimicrobial use reduction in cattle and poultry production. In view of these objectives, the findings of this thesis are presented in five scientific papers. Paper 1: A systematic literature review was conducted to provide an overview of methods of measuring AMU and metrics used, reviewing existing data on AMU in cattle and poultry production in order to identify gaps in Sub-Saharan Africa. The study revealed a deficit of studies on estimate of quantity and quality of antimicrobials used in food-producing animals in Sub-Saharan Africa. Paper 2: A cross-sectional study was conducted on 116 farms (51 poultry and 65 small-scale dairy cattle) in Ilala, Kinondoni and Ubungo Districts of Dar-es-Salaam region, Eastern Tanzania from 15th August to 30th September 2019 to investigate the level of antimicrobial use practice, type and quantity (amount) of antimicrobials consumed. The study revealed that 23 (19.8%) of the farms visited had records while 93 (80.2%) relied on recall, 58.6% of the livestock farmers had adequate level of practices (favorable) in accordance to antimicrobial use based on their responses, the most commonly used class of antimicrobials in poultry production were: Fluoroquinolones (25.5%), sulphonamides (21.6%), tetracycline (11.8%) while in the small-scale dairy farms, tetracycline (20.0%), beta-lactams (18.5%), sulphonamides (12.3%) were most commonly used. Quantitatively, in the poultry farms, the frequently used antimicrobial class sulphonamides (46.1%), tetracycline (19%) and Macrolides (14.2%). In the small-scale dairy farms, the use beta-lactams (36.4%), sulphonamides (22.3%), tetracycline (14.3%) were predominant. For Paper 3: a cross-sectional study, using data extraction form to collate antimicrobial use data from sales records (three consecutive years) of five established licensed veterinary pharmaceutical wholesales/outlets which were purposively selected in Ilala, Kinondoni and Ubungo. The study revealed that 178.4 tonnes of antimicrobials (by weight of active ingredients) were consumed during the 3 year study period (2016-2018), with an average of 59.5 ± 3.8 tonnes/year. The commonly sold antimicrobials were tetracycline (44.4%), sulphonamides (20.3%) and aminoglycosides (10.3%). Regarding veterinary antimicrobial use importance to human medicine, 34.4% were critically important antimicrobials; 4.1% were reserve and 51% were watch groups according to AWaRe categorization of WHO. Overall, a mean of 7.44 ± 0.81 mg/PCU (population correction unit) was consumed by food-producing animals during the three-year study period. Paper 4: A cross-sectional study was conducted in 54 of the previously visited farms where a pre-tested questionnaire on antimicrobial (antibiotics) usage was completed. A total of 121 E. coli isolates were obtained from 201 sampled small-scale dairy cattle rectal swabs. Looped rectal swab specimens from Stuart transport medium, were streaked directly onto plain MacConkey agar (Oxoid, Basingstoke, UK) and aerobically incubated at 370C for 24 hours. Presumptive E. coli colonies were Gram stained and then subjected to biochemical tests (Indole test, Methyl red test, Voges-Proskauer test and Citrate Utilisation test; IMViC test) for identification. E. coli strain ATCC 29522 was used as a reference organism. Antimicrobial susceptibility testing (AST) was performed against eight types of antimicrobials: (Tetracycline, (TE) (30 μg), Ampicillin, (AMP) (10 μg), Gentamicin, (CN) (10 μg), Ciprofloxacin,(CIP) (5 μg), Cefotaxime,(CTX) (30 μg), Nalidixic Acid, (NA) (30 μg), Trimethoprim/Sulfamethoxazole, (SXT) (1.25/23.75μg) and Chloramphenicol,(C) (30 μg)). The highest prevalence of AMR was against AMP (96.7%), CTX (95.0%), TE (50.4%) and SXT (42.1%). The 121 isolates of E. coli belong to 41 different phenotypes showing a variation of resistance. The most frequently observed phenotypes were AMP-SXT-CTX with a prevalence of 12.4%, followed by the combination AMP-CTX with 10.7% and TE-AMP-CTX and NA+TE+AMP+CTX with 8.3% each. Fifteen different phenotypes that produce Extended Spectrum Beta-Lactamases (ESBLs) were detected with a prevalence of 42.9% and 74.4% of E.coli isolates exhibited multidrug resistance (MDR). This probably confirms that antimicrobial use is unregulated and thus inappropriate use which led to the emergence and development of resistance. Paper 5: A cross-sectional study was conducted on randomly sampled broiler farms which were in production for one year in Kinondoni and Ubungo Districts in Dar es Salaam region of Tanzania from February to March 2021. A pre-tested questionnaire was used to capture data required to complete the model for the estimation of the economic effects (costs and benefits) on reduction of antimicrobial use. Data collected included: number of chicks bought and dead on the farm (mortality), observed clinical signs; signs of respiratory infections (coughing, wheezing, sneezing and nasal discharge), enteric infection (diarrhea) and lameness (locomotive signs) (morbidity). A Mclnerney model built on biological and economic parameters of disease effects on livestock production was used to analyze the data. The net costs and benefits were estimated within a partial budgeting framework in the model. The results of this study showed that antimicrobial use reduction will have an effect on mortality and morbidity and thus increase the cost of production due to changes in additional management changes (animal health management and technical management). Findings from this thesis recommend that rational AMU should be emphasized by targeting cattle and poultry production in Tanzania in general and Dar es Salaam in particular.
Antiviral activity of crude extracts of Synadenium glaucescens (Pax) against infectious bursal disease and fowlpox virus
(2013-04-10) Mabiki, F. P.; Mdegela, R. H.; Mosha, R. D.; Magadula, J. J.
The effect of crude extracts from different morphological parts of Synadenium glaucescens against infectious bursal disease virus (IBDV) and fowlpox (FP) virus using an in ovo assay were investigated. Viable 9 days embryonated chicken eggs were challenged with viral strains then treated with S. glaucescens extracts at concentration of 0.2 mg/ml. Un-inoculated group were saved as negative control and groups inoculated with virus and diluent saved as positive controls. The treatments were observed daily and embryo weights were measured 5 days post-inoculation. Embryo survival and mean embryo weight were significantly higher (P ≤ 0.001) in groups treated with S. glaucescens extracts than the positive control. More than 50% of the extract prevented death and deformation of embryo and formation of pock lesions in embryos. Furthermore, the treatments with ethanolic extract of the root bark demonstrated significantly higher mean embryo weight compared to other extract for both viruses (P ≤ 0.001). The mean embryo weights from eggs challenged with infectious bursal disease virus and fowlpox virus treated with the extract were 6.3 ± 2 and 5.9 ± 0.5 g, respectively. These findings demonstrate potential and feasibility of using S. glaucescens extracts for treatment of the viral diseases. Furthermore, it validates the ethnoveterinary exploitation at community level.
Application of real-time RT-PCR assay for detection and typing of foot-and-mouth disease virus in Tanzania
(Sokoine University of Agriculture, 2015) Mero, Herieth R.
Speed is paramount in the diagnosis of highly infectious Foot-and-mouth disease (FMD). Recent developments in molecular biology have enabled specific detection of FMD virus by real-time RT-qPCR and sequencing in endemic settings in Africa. In this study, a laboratory-based experimental design was used to standardize real-time RT-qPCR assay for detection and typing of FMDV in selected regions of Tanzania. The optimized conditions for both pan-serotypic and serotype-specific real-time RT-qPCR assays were: reverse transcription (at 60°C for 30minutes), denaturation of reverse transcriptase and activation of DNA polymerase (at 95°C for 10minutes followed by 95°C for 15 seconds), annealing and elongation temperature (at 60°C for 1 minute) for 52 cycles. FMD virus were detected in 100% (n = 14) archived samples that were collected between 2010 and 2013 from confirmed FMD-cases. The standardized real-time RT-qPCR assays revealed 100% sensitivity and 100% specificity for detection and typing of FMDV, respectively.The frequency of FMDV detection among FMD-suspected cases of cattle collected from 2008 to 2014 in selected regions of Tanzania was 92% (n = 23). Of the 23 positive samples, 56.5% (n = 13), 8.7% (n = 2), 21.7% (n = 5), and 8.7% (n = 2) were typed into serotypes O, A, SAT 1 and SAT 2 respectively. One sample (4.3%) was positive for both serotype A and SAT 1. These findings indicate that the standardized pan-serotypic and serotype-specific real-time RT-qPCR assays have a potential use in detection and typing of FMDV field strains in endemic settings of Tanzania and Africa at large. Application of standardized real-time RT-qPCR assays could hasten diagnosis of FMDV that guide selection of effective FMD-control measures in the region. In-depth studies, including sequencing of one sample that revealed positive for two serotypes, are required to elucidate the possibility of mixed infection among FMD cases.
Are we prepared for emerging and re-emerging diseases? Experience and lessons from epidemics that occurred in Tanzania during the last five decades
(2011-12) Rweyemamu, Mark M; Mmbuji, Peter; Kivaria, Fredrick M; Simba, Azma; Mbugi, Erasto; Karimuribo, Esron D; Mboera, Leonard E.G
This paper reviews preparedness for containing and controlling emerging and re-emerging diseases drawing lessons from disease events that occurred in animal and human populations in the last five decades (1961-2011). A comprehensive analysis based on retrieval and analysis of grey and published literature as well as reported cases was carried out to document type and trend of occurrence of emerging and re-emerging infectious diseases in different parts of Tanzania. Overall, the majority of diseases reported in the country were viral in nature followed by bacterial diseases. The trend for the occurrence shows a number of new emerging diseases as well as re-occurrence of old diseases in both animal (domestic and wild) and human populations. In humans, the major disease epidemics reported in the last five decades include cholera, influenza A H1N1, plague and rubella. In animals, the major epidemic diseases reported were Contagious Bovine Pleuropneumonia, Contagious Caprine Pleuropneumonia, Peste des petits ruminants and Giraffe Ear and Skin Diseases. Some epidemics have been reported in both human and animal populations including Rift Valley fever and anthrax. The emergence of the ‘fit-for purpose’ approaches and technologies such as the discipline of One Health, use of participatory epidemiology and disease surveillance and mobile technologies offers opportunity for optimal use of limited resources to improve early detection, diagnosis and response to disease events and consequently reduced impact of such diseases in animal and human populations.
Are we prepared for emerging and re-emerging diseases? experience and lessons from epidemics that occurred in Tanzania during the last five decades
(2012-03) Karimuribo, E.D; Mboera, L. E.G; Mbugi, Erasto; Simba, Azma; Kivaria, F. M; Mmbuji, Peter; Rweyemamu, M. M
his paper reviews preparedness for containing and controlling emerging and re-emerging diseases drawing lessons from disease events that occurred in animal and human populations in the last five decades (1961-2011). A comprehensive analysis based on retrieval and analysis of grey and published literature as well as reported cases was carried out to document type and trend of occurrence of emerging and re-emerging infectious diseases in different parts of Tanzania. Overall, the majority of diseases reported in the country were viral in nature followed by bacterial diseases. The trend for the occurrence shows a number of new emerging diseases as well as re-occurrence of old diseases in both animal (domestic and wild) and human populations. In humans, the major disease epidemics reported in the last five decades include cholera, influenza A H1N1, plague and rubella. In animals, the major epidemic diseases reported were Contagious Bovine Pleuropneumonia, Contagious Caprine Pleuropneumonia, Peste des petits ruminants and Giraffe Ear and Skin Diseases. Some epidemics have been reported in both human and animal populations including Rift Valley fever and anthrax. The emergence of the ‘fit-for purpose’ approaches and technologies such as the discipline of One Health, use of participatory epidemiology and disease surveillance and mobile technologies offers opportunity for optimal use of limited resources to improve early detection, diagnosis and response to disease events and consequently reduced impact of such diseases in animal and human populations. ____________________________

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