Browsing by Author "Katakweba, A. S."

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Assessment of raw cow milk quality in smallholder dairy farms in Pemba Island Zanzibar, Tanzania
(Hindawi, 2018-03-12) Gwandu, S. H.; Nonga, H. E.; Mdegela, R. H.; Katakweba, A. S.; Suleiman, T. S.; Ryoba, R.
Milk quality depends on the physicochemical characteristics, hygienic standards, and nutritional quality; however, animal husbandry practices, unhygienic harvesting and processing, may affect its quality. A cross-sectional study was conducted between August 2010 and July 2011 to assess the hygiene of cow milk production environment, raw cow milk physicochemical characteristics, and microbial quality and estimate the prevalence of antimicrobial residues using standard methods in Pemba Island. A total of 98 raw cow milk samples from selected smallholder dairy farms were analyzed, and the judgement on the quality used the East African Standards. Generally, the milk production chain was done under the unhygienic condition, and dirty plastic containers were used for collection and storage of milk under room temperature. Some milk samples had abnormal colour (2.1%), abnormal smell (7.1%), and pH below normal (35.7%), clotted on alcohol test (9.2%), and had the specific gravity below normal (13.3%). All the milk samples had mineral contents within the recommended range. Milk samples with butterfat below normal were 29.6%, while 14.3% had total solids below recommended values. The mean total viable count (TVC) of milk container surfaces was log CFU/100 cm2, while total coliform count (TCC) was log CFU/100 cm2. Up to 55.1% of milk had TVC beyond the recommended levels. The milk mean TVC was log CFU/ml and TCC was log CFU/ml. Up to 26.5% of milk samples had the TCC beyond levels. Results on physicochemical characteristics and nutritional analysis show that the raw cow milk in Pemba Island is of inferior quality. Microbiological results of this study imply heavy contaminations of milk. Antimicrobial residues were detected in 83% of the samples and most of them were from Wete District. Unhygienic milk production chain accelerates microbial contaminations, and antimicrobial residues in milk are a big problem that needs urgent attention from the responsible authority.
spa typing and antimicrobial resistance of staphylococcus aureus from healthy humans, pigs and dogs in Tanzania
(The Journal Infection Developing Countries, 2016-07) Katakweba, A. S.; Muhairwa, A. P.; Espinosa -Gongora, C.; Guardabassi, L.; Mtambo, M. A.; Olsen, J. E.
Introduction: Staphylococcus aureus is an opportunistic pathogen causing infections in humans and animals. Here we report for the first time the prevalence of nasal carriage, spa typing and antimicrobial resistance of S. aureus in a Tanzanian livestock community. Methodology: Nasal swabs were taken from 100 humans, 100 pigs and 100 dogs in Morogoro Municipal. Each swab was enriched in Mueller Hinton broth with 6.5% NaCl and subcultured on chromogenic agar for S. aureus detection. Presumptive S. aureus colonies were confirmed to the species level by nuc PCR and analysed by spa typing. Antimicrobial susceptibility patterns were determined by disc diffusion method. Results: S. aureus was isolated from 22 % of humans, 4 % of pigs and 11 % of dogs. A total of 21 spa types were identified: 13, 7 and 1 in human, dogs, and pigs, respectively. Three spa types (t314, t223 and t084) were shared between humans and dogs. A novel spa type (t10779) was identified in an isolate recovered from a colonized human. Antimicrobials tested revealed resistance to ampicillin in all isolates, moderate resistances to other antimicrobials with tetracycline resistance being the most frequent. Conclusion: S. aureus carrier frequencies in dogs and humans were within the expected range and low in pigs. The S. aureus spa types circulating in the community were generally not shared by different hosts and majority of types belonged to known clones. Besides ampicillin resistance, moderate levels of antimicrobial resistance were observed irrespective of the host species from which the strains were isolated.
Spatio-temporal patterns in the distribution of the multi-mammate mouse, Mastomys natalensis, in rice crop and fallow land habitats in Tanzania
(Mammalia, 2015) Mulungu, L. S.; Sixbert, V.; Ngowo, V.; Mdangi, M.; Katakweba, A. S.; Tesha, P.; Mrosso, F. P.; Mchomvu, M.; Kilonzo, B. S.; Belmain, S. R.
: An understanding of the dispersion patterns of a pest is an important pre-requisite for developing an effective management programme for the pest. In this study, rodents were trapped in two rice fields and two fallow fields for three consecutive nights each month from June 2010 to May 2012. Mastomys natalensis was the most abundant rodent pest species in the study area, accounting for > 95% of the trapped rodent community. Rattus rattus, Dasymys incomtus, Acomys spinosissimus and Grammomys dolichurus comprised relatively small proportions of the trapped population. Morisita’s index of dispersion was used to measure the relative dispersal pattern (aggregate, random, uniform) of individuals across each trapping grid as a means of comparing rodent distribution in rice and fallow fields over time. This analysis revealed that the rodents in rice fields generally exhibited an aggregated spatio-temporal distribution. However, the rodents in fallow fields were generally less aggregated, approaching a random distribution in some habitats and seasons. Heat maps of trapping grids visually confirmed these dispersal patterns, indicating the clumped or random nature of captured rodents. ANOVA showed that the parameters of habitat (rice, fallow), crop stage (transplanting, vegetative, booting, maturity) and cropping season (wet, dry) all significantly impacted the number of rodents captured, with the vegetative, dry season, fallow habitat having the highest number of rodents; and the transplanting, wet season, rice habitat with the least number of rodents. Therefore, such spatio-temporal patterns can serve as a tool for developing stratified biodiversity sampling plans for small mammals and decision making for rodent pest management strategies.
Spiny mice of the Zambezian bioregion – phylogeny, biogeography and ecological differentiation within the Acomys spinosissimus complex
(ELSEVIER, 2018-03-23) Katakweba, A. S.; Petruzela, J.; Sumbera, R.; Aghova, T.; Bryjova, A.; Sabuni, C. A.; Chitaukali, W. N.; Bryja, J.
Despite the high degree of biological diversity in the Zambezian region, little information is available regarding the evolutionary history of its biota, and this is especially true for the fauna and flora of non-forested habitats. Here we use the most comprehensive multi-locus genetic dataset available to (1) reconstruct the phylogeny of spiny mice of the Acomys spinosissimus complex and to describe the spatial distribution of its genetic diversity; (2) to assess the level of reproductive isolation between genetic clades; (3) to analyse differences in climatic niche between potential species; and (4) to model their current and past distribution. The complex comprises four main genetic clades that correspond to four nominal species living in the east of the Zambezian region. Their distribution is delimited by important geographical divides including the Eastern Arc Mountains, Lake Malawi and the Zambezi River. Two species considered Tanzanian endemics, A. ngurui and A. muzei, are now known to be more widespread than previously thought and they have their centres of genetic diversity just north of the Zambezi. The first split between the extant members of the A. spinosissimus complex is estimated at 3 Mya. Most intraspecific diversification events are thought to have occurred in the Pleistocene, suggesting that climatic oscillations played an important role in their diversification. The climatic niches of parapatric taxa differ significantly; hence, local adaptations have likely played an important role in reproductive isolation. Species distribution modelling predicts a dramatic reduction of occurrence probability across the area during the last interglacial period, facilitating allopatric diversification of fragmented populations. Our results strongly suggest the combined role of Pleistocene climatic change, biogeographical barriers and local adaptation in forming current taxa diversity in east African savannah-like habitats. While such processes have frequently been observed in forest-living organisms (theory of allopatric diversification in forest refugia), similar mechanisms were likely also working in open ecosystems ("savannah refugia").
Survival and recruitment of the multimammate mouse, Mastomys natalensis (smith 1834), in a rice agro-ecosystem
(Mammalia, 2016) Mulungu, L. S.; Ngowo, V.; Mdangi, M. E.; Katakweba, A. S.; Tesha, P.; Mrosso, F. P.; Mchomvu, M.; Massawe, A. W.; Monadjem, A.; Kilonzo, B.; Belmain, S. R.
We investigated the recruitment and survival of the multimammate mouse, Mastomys natalensis, within irrigated rice and fallow field habitats at different time periods related to rice crop growth stages. Capture-Mark- Recapture data were collected for M. natalensis each month from June 2010 to May 2012, and both recruitment and survival were estimated in relation to land use (irrigated rice or fallow field) within the agro-ecosystem. Higher recruitment and survival were observed in rice fields than in fallow fields suggesting the relationship was compensatory when there was a higher quality food resource. In terms of management, farmers in the study area should implement management strategies in rice fields at both transplanting and maturity stages of crop growth in order to maintain recruitment and survival at low levels.