Theses and Dissertations Collection

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Adaptation of reverse transcription loop- mediated isothermal amplification for field diagnosis of foot-and- mouth disease in Tanzania
(Sokoine University of Agriculture, 2016) Kandusi, Sengiyumva Emmanuel
Foot-and-mouth disease (FMD) is a highly contagious viral vesicular disease of cloven hoofed animals and poses major constraints to international trade in livestock production. Methods available for detection of FMD virus (FMDV) require specialized laboratory facilities and equipment. In this study, targeted laboratory- based experiments studies were conducted using reverse transcription loop-mediated isothermal amplification (RT-LAMP) for detection and serotyping of FMDV under field conditions. Pan-serotypic RT-LAMP utilizing labeled and unlabeled primers was used for detection of the virus. Serotype-specific primers for FMDV serotypes A and O were used to type the positive samples using RT-LAMP. Amplification was observed in real-time for unlabeled primers and by molecular lateral flow devices for labeled primers. Also, gel electrophoresis was used for examination of deoxyribonucleic acid (DNA) bands. A total of 35 samples (n = 35) were examined using RT-LAMP. Of these, 40% (n=14) were positive from different regions in Tanzania. The positive samples were from Iringa with 29% (n=4), Morogoro with 14.2% (n=2), as well Kilimanjaro, Mara, Tanga, Tabora, Mtwara, Kagera Dar es Salaam and Mwanza with 7.1% (n=1) each. All the pan- serotypic RT-LAMP positive samples revealed time for positivity ranging from 12-30 minutes. These findings indicate that the standardized RT-LAMP assay reported in this study can be used for field detection of FMDV in suspected FMD outbreaks in Tanzania. These findings suggest a potential use of serotype-specific RT-LAMP for typing FMDV field strains.
Arbovirus infections in aedes mosquitoes at the interface of human-livestock-wildlife ecosystem in Kilosa district, Tanzania
(Sokoine University of Agriculture, 2020) Machelle, I. S
Arboviruses refer to a group of viruses, which are transmitted by arthropods including mosquitoes and ticks. The objective of this study was to determine mosquito transmission potential of arboviruses at the interface of human-livestock-wildlife ecosystem in Kilosa district, Tanzania. Adult mosquitoes were collected using Mosquito Magnet® Liberty Plus traps. Reverse transcription polymerase chain reaction assay was performed on pooled adult Aedes mosquitoes to detect the presence of Dengue virus (DENV), Chikungunya virus (CHIKV), Rift Valley fever virus (RVFV) and Yellow fever virus (YFV). A total of 1340 mosquitoes belonging to four genera (Aedes, Anopheles, Culex and Mansonia) and 6 species were collected. Culex accounted for the largest (48.06%; n= 644) proportion of the mosquitoes while Anopheles for the lowest proportion (2.54%; n=34). Of the total mosquitoes collected, Aedes aegypti accounted for the majority of mosquito species (46%; n=613), followed by Culex quinquefasciatus (44.1%; n=591). Of the 36 Ae. aegypti pools tested for arbovirus 10 (28%) pools were positive. Dengue virus was detected in 3% (1/ 36) pools and CHIKV in 25% (9/ 36) pools. One pool that was positive for DENV also tested positive for CHIKV indicating the possibility of co-infection whereby, individuals may become infected by more than one arbovirus at a time thus risk of co-transmission to human and livestock. Nucleotide sequencing of polymerase chain reaction (PCR) products of the structural polyprotein region of DENV produced 511 bp fragment. Basic Local Alignment Search tool for nucleotides (BLASTn) and phylogenetic analysis showed that the (DENV3/TAN/Mikumi/2020 strain) (Accession number MW133786) obtained from this study clustered with DENV-3 strains reported in China and Kenya. This information is important as it gives knowledge on areas at high risk for arboviral disease outbreaks. The findings indicate that the presence of various mosquito vectors and detection of arboviruses in wild-caught Aedes mosquitoes leave the population of Kilosa district at a higher risk of transmission of DENV and CHIKV
Assessment of genetic diversity of maize landraces in Tanzania using Random Amplified Polymorhic DNA markers
(Sokoine University of Agriculture, 2016) Asigbee, T. W.
The knowledge and comprehension of the genetic variation of maize (Zea mays L.) landraces is pivotal for the implementation of measures to address conservation and improvement. The purpose of this study was to assess the genetic diversity and relationship among selected maize genotypes in Republic of Tanzania by screening twenty Random Amplified Polymorphic DNA molecular markers.DNA was extracted from 160 maize genotypes and PCR was conducted using twelve informative primers. Amplification revealed 104 polymorphic bands with an average of 8.67 polymorphic fragments per primer. The number of amplified fragments ranged from 7 (OPP-02) to 10 (OPK-08), with the amplicon sizes ranging from 75 to 2000 base pairs. The polymorphic information content (PIC) ranged from 0.7487 to 0.954 with an average of 0.8647 and gene diversity value ranged from 0.7531 to 0.9577 with an average of 0.8698.The dendrogram drawn based on Neighbour- Joining method revealed the diversity and genetic relatedness among the landraces in the various clusters but did not reflect the geographical locations of the studied maize genotypes. This might be attributed to the high gene flow in the various study locations.The analysis of the RAPD molecular markers revealed a high genetic diversity among the maize landraces and proved to be a practical method for assessing polymorphism in maize cultivars. These findings will be useful to establish and improve the current germplasm collection of landraces and help maximize the utility of maize genetic resources.
Assessment of illegal bushmeat using high thoroughput molecular tools in transboundary villages bordering Serengeti ecosystem in Tarime District, Tanzania
(Sokoine University of Agriculture, 2018) Kilwanila, S. I.
Detection of illegal bush-meat in Africa has over the years relied on morphological identification technique, which is less effective due to post-hunting procedures. Therefore, the current study aimed at assessing bush-meat dynamics in trans-boundary areas of Tanzania and Kenya in the western part of Serengeti ecosystem. A cross-sectional design with two different methodologies was used. First, semi-structured questionnaires were administered to collect information on socio-demographic and other social factors leading to illegal bush-meat hunting, preference and consumption. Secondly, to augment the information obtained from the questionnaire, qPCR-HRM analysis was employed by using three different molecular markers 16s, Cytb and COI for molecular identification of assumed 138 collected sundried bush-meat samples. The results indicated that hunting occurs mostly in the dry season primarily using snares, and wildebeest was revealed to be the most hunted. Furthermore, young demonstrated high bush-meat consumption whereas immigrants showed high bush-meat preference. Likewise, highly educated young respondents indicated to have a high consumption and preference than less educated old respondents. Regarding molecular identification, 20 species were identified altogether, with zebra constituting the majority (n=51, 49.5%). It is recommended that high surveillance against poaching is needed by wildlife authorities during dry season; proper disposal of the unworthy wire cables by TANESCO; sensitization of both primary and secondary school students on legal harvesting of wildlife were made. Other recommendations focused on the need for proper execution of HRM procedures for bush- meat identification; and that for bush-meat samples to be accepted in court of law as exhibits should be analyzed using molecular procedures that proved to be reliable.
Assessment of pesticide residues in harvested tomato fruits at Makambako town council in Njombe Region, Tanzania.
(Sokoine University of Agriculture, 2021) Bilaro, Jansen Stanslaus
In modern agriculture, pest infestation has posed a great challenge to farmers. The use of pesticide has eventually become an important tool to ensure quality and quantity of crop yields. However, such chemicals might have residual impacts to consumers. This study was conducted to assess the extent of pesticide residues in harvested tomato fruits at Makambako Town Council in Njombe region, Tanzania. Specifically the study aimed at: (i) investigating adherence to recommended manufacturer’s instructions on pesticide application among tomato farmers (ii) determining level and frequency of occurrence of selected pesticide residues in tomato fruits and (iii) characterizing dietary risks associated with consumption of fresh tomato fruits containing pesticide residues. Forty seven (47) farmers were interviewed on pesticide types and their application using structured questionnaire. Forty two (42) fresh tomato fruits for laboratory analysis were sampled from interviewed farmers who were at harvesting season. QuEChERS (CEN) Method 15662.5 was employed for pesticide extraction and analyzed by Gas Chromatography Mass Spectrometer. It was found that all respondents mixed more than one pesticide in a single spray tank without adhering to recommended mixing procedures. The average withholding period was 5 days, below the recommended 7 days for mixture of mancozeb and metalaxyl which were commonly used fungicides at the study area. Eighty three percent of the respondents exceeded the mixing concentration of pesticide above the recommended mixing ratios. Residues of chlorpyrifos, profenofos, gamma cyhalothrin and cypermethrin were alternatingly detected in 78.51 % of analyzed samples. The average concentrations of residues were 0.014, 0.056, 0.003 and 0.2 mg/kg for chlorpyrifos, profenofos, gamma cyhalothrin and cypermethrin, and were all below Codex MRLs of 1, 10, 0.3 and 0.2 mg/kg respectively, as per FAO/WHO guidelines. The maximum residue concentration was 0.718 mg/kg for cypermethrin, which was above the Codex MRL of 0.2 mg/kg. Profenofos was the most frequently detected pesticide, occurring in 60 % of samples. The hazard indices for the selected pesticide indicate no potential health hazards to general population due to lifetime consumption of fresh tomato fruits from the study area. The study recommend regular training to farmers on good agricultural practices through extension officers and pesticide regulatory authority. Further research on pesticide residues and dietary risk assessment is recommended for other pesticide commonly used at the study area.
Association of Betaine Aldehyde Dehydrogenase 2.1 (Badh2.1) Gene Allele with aroma in popular traditional rice varieties in Tanzania
(Sokoine University of Agriculture, 2016) Moshi, W. E.
Aromatic rice is highly cherished in many countries of the world and commands premium prices at all levels of the global rice trade. The presence of aroma in aromatic rice is controlled by betaine aldehyde dehydrogenase 2.1 (BADH2.1) gene allele which results from an eight base pair deletion and three single nucleotide polymorphisims (SNPs) in exon seven of betaine aldehyde dehydrogenase 2 (BADH2) gene. This mutation is responsible for the introduction of premature stop codon which produce a truncated protein, this results in loss of function of the enzyme betaine aldehyde dehdrogenase 2 (BADH2) leading to accumulation of substrate (main aroma compound) 2-acetyl 1-pyrroline (2AP) in aromatic rice varieties. In this study, the association between BADH2.1 aromatic allele and aroma in Tanzanian rice varieties was investigated. Leaf and grain aromatic tests for aroma evaluation and screening for BADH2.1 gene allele using allele specific amplification (ASA) marker were conducted in 160 popular traditional rice landraces from different geographical regions of Tanzania. Of the 160 landraces genotyped and phenotyped; 95 varieties were classified as aromatic by the presence of aroma in both leaf and grain aromatic tests, most of these (91.6 %) carried BADH2.1 gene allele. Evidence from sequencing of BADH2/BADH2.1 alleles confirmed the association of BADH2.1 gene allele with aroma in aromatic rice landraces as it was shown that all aromatic genotypes had eight base pair deletion and three SNPs in exon seven of BADH2 locus. This suggests that BADH2.1 gene allele is the main aroma allele in most of the Tanzanian aromatic rice varieties. Phylogenetic analysis of BADH2/BADH2.1 nucleotide sequences, showed a large amount of genetic variability (39.41-100 % nucleotide sequence identity) among the varieties studied. These findings will contribute siginificantly in planning for effective rice breeding strategies especially in selection of appropriate parental materials for developing high yielding aromatic rice varieties in the country.
Bioactivity of Synadenium glaucescens (pax) extracts on helminth eggs and larvae from wastewater stabilization ponds in Morogoro municipality,Tanzania
(Sokoine University of Agriculture, 2015) Hassan, S.
The increased use of wastewater and sludge from wastewater stabilization ponds in agriculture predisposes the consumers to the health risks. The objective of this study was to evaluate the bioactivity of Synadenium glaucescens (Pax) extracts on helminth eggs and larvae from wastewater and sludge in Morogoro. Helminth eggs and larvae were recovered using Bailenger and Baerman methods, and then quantified using McMaster techniques. Extracts (S. Glaucescens) used during hatchability and larvicidal bioassays were obtained using hot and cold solvent extraction. The effect of S. glaucescens extracts on hatchability and larvicidal was tested using in vitro and in vivo methods. One litre of wastewater was collected from anaerobic, facultative and maturation ponds. One hundred grams of sludge were sampled from the ponds and piles. Lethal concentration fifty (LC50) and inhibitory concentration fifty (IC50) were used to determine larvicidal and hatchability effects. The identified helminth eggs were from nematodes including Ascarid, Strongylid and Trichuris. Minimum amount of ≤ 1 e.p.l. were found in wastewater sampled from maturation ponds, same amount recommended by WHO guideline of 2006, and a maximum of 700 e.p.l. from anaerobic ponds. It was found that sludge samples contained a minimum of ≤ 1 e.p.g. from maturation ponds and maximum of 100 e.p.g. in anaerobic pond. The ethanol extracts of root bark and leaves were the most effective with IC50 19.34 and 39.56 μgml-1. The two extracts also demonstrated the highest LC50 of 19.41 and 30.19 μgml-1 respectively. The root bark extracts were more active than leaves extracts. This study demonstrated a high potential of using S. glaucescens extract in controlling helminths in wastewater and sludge.
Cyanide levels in raw sweet cassava varieties and people’s perception on cyanide poisoning in Kagera and Morogoro regions of Tanzania
(Sokoine University of Agriculture, 2018) Mushumbusi, C. B.
Cassava (Manihot esculenta Crantz), an edible crop that is renowned out of its growth advantages over other crops, carries cyanide which is potentially poisonous to humans. The threat is intensified by human habit of consuming raw cassava tubers whose toxicological status is not established. Cases and indicators of cyanide poisoning due to cassava consumption are evident in Tanzania, particularly in Kagera and Morogoro regions. This study was launched to quantify cyanide in tubers of sweet cassava varieties grown in Kagera and Morogoro regions and thereafter to assess if it is safe for humans to consume raw tubers of sweet cassava varieties grown in the study area. Another objective was to assess whether the habit of consuming raw cassava tubers was out of people’s lack of awareness about cyanide and its poisoning effects or negligence. The study employed cross-sectional research design to collect participants’ responses on cyanide and its associated poisoning effects and to determine cyanide levels in sweet cassava tubers by using alkaline titration method. Sixty six tubers of 12 sweet cassava varieties from the study area were analyzed and 386 participants were involved in the study. The study findings showed that cyanide levels in the raw sweet cassava tubers were above the internationally accepted level in human consumables (10 mg/kg) and thus unfit for human consumption in their raw state. Some sweet varieties were found to be wrongly classified as sweet because their cyanide content was above 50 mg/kg. The inconsistency of cyanide levels in tubers of similar variety showed that a variety can exist in both sweet and bitter forms depending on environmental factors, making the categorization of varieties into sweet and bitter varieties misleading. Furthermore, the habit of consuming raw cassava tubers was found to be mostly cultivated by people’s lack of awareness with regard to the presence of cyanide in cassava tubers (86%) and on cyanide poisoning effects (81%) respectively. It was also found out that the slippery tissue and the inner tissue of the cassava parenchyma differ significantly in cyanide content so that the habit of scratching off the slippery tissue contributes to reduction of cyanide in cassava tubers. This research work recommends that the public should be sensitized on the issue of cyanide in cassava, the poisoning effects it has to human health as well as ways of identifying and dealing with the poison contained in cassava tubers prior to human consumption. Apart from inventing simple, inexpensive and efficient cyanide quantifying devices, genetically modified cassava varieties need be produced and disseminated in which the gene for cyanide expression is either masked or removed as an attempt to protect people against cyanide poisoning.
Detection and characterization of mosquito-borne viruses circulating in mosquitoes of Morogoro Municipality, Tanzania
(Sokoine University of Agriculture, 2016) Ahedor, Believe
Mosquito-borne viruses primarily infect animals and humans causing significant public and veterinary health threat. Transmitted by hematophagous mosquitoes, dengue virus and Rift Valley fever virus are the most common outbreaks that occurred in parts of Tanzania especially in malaria endemic areas. Several studies reported the presence of the viruses in circulation in animals and humans. Therefore, this study sought to investigate the diversity of mosquito-borne virus vectors and to assess the risk of mosquito-borne viral transmission in Morogoro municipality. Molecular detection of these viruses was carried out on Aedes aegypti using reverse transcription polymerase chain reaction (RT-PCR). A total of 7649 mosquitoes comprising of 7224 adults and 424 larvae belonging to five genera (Aedes, Anopheles, Culex, Eretmapodites, Mansonia) and 14 species were collected. The predominant specie was Culex quinquefasciatus 53.9% (n=3891) and Aedes aegypti 44.2% (n=3192), most of the species 43.7% (n= 3156) were collected in Mbuyuni, 22% (n=1587) from Kiwanja cha Ndege, 19.2% (n=1387) from Mwembesongo and Mazimbu and Kilakala with 7.6% (n=549 and 545) respectively. About 70% of the Aedes spp were collected from used car tyres - the major breeding sites. The mosquitoes’ 18S ribosomal ribonucleic acid (rRNA) and viral RNA were successfully amplified, but no specific viruses were detected. However, for the mosquito pools positive for flavivirus, by sequencing the generated PCR products, it was found that there could be false positives due to non-specific amplification of mosquito ribosomal RNA or amplification of arboviral-like sequences integrated into the Ae. Aegypti genome. Nonetheless, this result provides an insight into the abundance and distribution of potential vectors in these wards. The close proximity of these vectors to humans poses high risk of virus transmission in the municipality and calls for rational vector control measures
Detection of Arenaviruses in rodents, shrews and elephant shrews from selected wildlife-human interfaces in Tanzania
(Sokoine University of Agriculture, 2015) Maganga, Ruth
The present study was conducted to investigate the presence of Arenaviruses from rodents, shrews and elephant shrews captured in selected wildlife-human interfaces in Tanzania. The study involved six sites with high potential for contact between wildlife and humans namely; Ruaha, Kilombero, Mtwara, Mbeya, Mbinga and Mikumi. A total of 121 animals comprising 111 rodents, 3 shrews and 7 elephant shrews were screened for Arenaviruses using conventional Polymerase Chain Reaction (PCR). The genetic relatedness of Arenaviruses was evaluated by conducting phylogenetic analysis of partial sequences of the S gene. The association between age and sex with the presence of Arenaviruses was assessed. Of the 121 animals, 7 (5.8 %) were shedding Arenavirus. All positive animal samples were obtained from the Ruaha site at crop raiding and peridomestic interfaces. Eighty six percent of the infected animals were Mastomys sp. and 14 % were Arvicanthis sp. Age and sex of the animals were not significantly associated with occurrence of Arenaviruses in rodents, shrews and elephant shrews (P > 0.05). Additionally, Arenavirus detection in fecal specimens was not significantly different from the detection in oropharyngeal specimens (P > 0.05), clearly indicating that both specimens are useful for Arenavirus testing. Phylogenetic analysis showed that isolates obtained from this study were related to the Old World Arenaviruses, and include strains of Morogoro virus and a novel strain of Arenavirus. In conclusion, the present study has confirmed the presence of Arenaviruses closely related to other known Old World Arenaviruses in the Ruaha ecosystem.
Detection of Arenaviruses in rodents, shrews and elephant shrews from selected wildlife-human interfaces in Tanzania
(Sokoine University of Agriculture, 2015) Maganga, R.
The present study was conducted to investigate the presence of Arenaviruses from rodents, shrews and elephant shrews captured in selected wildlife-human interfaces in Tanzania. The study involved six sites with high potential for contact between wildlife and humans namely; Ruaha, Kilombero, Mtwara, Mbeya, Mbinga and Mikumi. A total of 121 animals comprising 111 rodents, 3 shrews and 7 elephant shrews were screened for Arenaviruses using conventional Polymerase Chain Reaction (PCR). The genetic relatedness of Arenaviruses was evaluated by conducting phylogenetic analysis of partial sequences of the S gene. The association between age and sex with the presence of Arenaviruses was assessed. Of the 121 animals, 7 (5.8 %) were shedding Arenavirus. All positive animal samples were obtained from the Ruaha site at crop raiding and peridomestic interfaces. Eighty six percent of the infected animals were Mastomys sp. and 14 % were Arvicanthis sp. Age and sex of the animals were not significantly associated with occurrence of Arenaviruses in rodents, shrews and elephant shrews (P > 0.05). Additionally, Arenavirus detection in fecal specimens was not significantly different from the detection in oropharyngeal specimens (P > 0.05), clearly indicating that both specimens are useful for Arenavirus testing. Phylogenetic analysis showed that isolates obtained from this study were related to the Old World Arenaviruses, and include strains of Morogoro virus and a novel strain of Arenavirus. In conclusion, the present study has confirmed the presence of Arenaviruses closely related to other known Old World Arenaviruses in the Ruaha ecosystem.
Determination of the level of expression of OsCIPK15 salt responsive gene in selected Tanzanian Rice Landraces
(Sokoine University of Agriculture, 2016) Kamanga, Naomi Olga
This was an experiment to determine the presence and level of expression of OsCIPK15 salt responsive gene in Tanzanian rice breeders’ lines. Abiotic stress is one of the factors affecting rice cultivation in Tanzania. The calcineurin B- like protein interacting protein kinases (OsCIPKs) responsive genes have been observed to express in abiotic stress. The calcineurin B- like protein interacting protein kinases-15 (OsCIPK15) salt responsive gene, which is usually a silent gene expresses in saline soils which is abiotic factor affecting yield. In this experiment eighty-four breeders’ lines were used for the study. The lines were grown in sterilized sandy soil and grown for two weeks in the greenhouse. After this period the two week old seedlings were uprooted and the roots submerged in saline solution of 200mM concentration for forty-eight hours. Leaf samples were collected exactly twenty-four hours, twenty-nine and forty hours and stored at -80˚C The samples were thereafter analysed using quantitative real-time polymerase chain reaction (QRT-PCR). Of the eighty-four breeders’ lines twenty-two gave a quantifiable analysis using the Livak delta analysis. Of the lines CSR 27, TXMS 1-2, TXM 18-1 and TXM 27 were the most tolerant and expressed the gene highly and TXM 13-2-3, GIZA 179, TXMS 14 and TXM 13-2-1 were the least. This experiment proves that Tanzanian breeders’ rice have inherent ability to tolerate abiotic stress, such as salinity and the lines studied can be used in breeding programs to develop rice salt tolerant varieties to be cultivated in susceptible areas in order to provide profitable yield for paddy growing rice farmers.
Development and evaluation of a reverse transcription loop-mediated isothermal amplification assay for rapid typing of serotype “o” foot-and-mouth disease virus in endemic settings of Tanzania
(Sokoine University of Agriculture, 2021) Njeru, Sarah Mueni
The foot-and-mouth disease (FMD) is an economically important transboundary animal disease (TADs) affecting all cloven-hoofed animals. It is caused by foot-and- mouth disease virus (FMDV), which has seven antigenically distinct serotypes. FMD is endemic in Tanzania, with outbreaks caused by predominantly five serotypes. In order to improve the control of this disease, for instance using serotype-specific vaccines, rapid detection and identification of circulating FMDV strains is of paramount importance. This study describes the development and evaluation of a reverse transcription loop- mediated isothermal amplification (RT-LAMP) assay for diagnosis of serotype ‘O’ FMDV in endemic settings in Tanzania. A retrospective study design was employed for this research whereby a total of forty-four (n=44) archived epithelial tissue samples were analyzed by RNA extraction, reverse transcription polymerase chain reaction (RT-PCR), RT-LAMP and DNA sequencing. Primers for RT-LAMP targeting serotype ‘O’ FMDV isolates in Tanzania were developed and found to optimally amplify the targeted gene at 65.0 ̊C for 45 minutes in the presence of both Avian Myeloblastosis Virus (AMV) reverse transcriptase enzyme and loop primers. The results indicated that RT-LAMP assay could amplify the viral protein 1 (VP1) gene of serotype ‘O’ FMDV within a range of 13 to 26 minutes, with annealing temperatures of between 70.0 and 89.0°C. The findings indicate that RT-LAMP assay is highly specific as no cross- reactivity occurred between serotype ‘O’ primers with any of the other serotypes. The sensitivity as indicated by the detection limit of the assay was deduced to be 3.78 ×10 -2 ng/μl. This study concludes that RT-LAMP assay could be used to rapidly and accurately detect VP1 gene of serotype ‘O’ FMDV from Tanzania. It is advisable that further studiesare required to evaluate the comparative sensitivity of the assay and check whether the assay is field deployable. Further evaluation is also needed to determine whether the assay would be useful for detecting serotype ‘O’ FMDV strains circulating in other regions in Tanzania.
Distribution and abundance of ticks on cattle and associated tick-borne pathogens from Kilombero and Iringa districts in Tanzania
(Sokoine University of Agriculture, 2023) Magesa. W. S
Ticks are a major group of arthropod vectors that transmit pathogens that cause devastating diseases in humans and animals. The information on tick infestation and related tick-borne pathogens in Tanzania is insufficient. Therefore, this study was conducted to determine tick prevalence and degree of infestation on cattle as well as associated tick-borne pathogens, in Kilombero and Iringa districts of Tanzania. A repeated cross-sectional study was conducted to collect ticks on cattle in wet and dry seasons from January to August 2021. Out of 740 cattle examined, 304 were infested with ticks. In total 1,780 ticks were counted on one side of the animal’s body and doubled, whereby a total of 3,560 ticks were recorded. A total of 1,889 tick were collected from the infected cattle including 109 more tick observed while collecting ticks based on the animal’s posture when restrained on ground. Thereafter, ticks were identified morphologically using published morphological keys under a stereomicroscope and confirmed using polymerase chain reaction (PCR) and sequencing of the mitochondrial CO1 and 16S rRNA genes. The tick-borne pathogens were detected using PCR. Fisher’s exact test was performed to detect the difference between the proportion of hard tick species and the study areas and season. One-way ANOVA was performed to compare mean tick burden between variables (including cattle age groups, body condition score and frequency of tick control). Out of 1,889 ticks, 1,377 fit in the genus Rhipicephalus, 459 in the genus Amblyomma and 53 in the genus Hyalomma. The most prevalent tick species identified were Rhipicephalus microplus (48.1%), Rhipicephalus evertsi (16.4%), and Amblyomma lepidum (16.4%). The sequencing results of the mitochondrial DNA fragments indicated high nucleotide identity (96-100%) with sequences in GenBank and Barcode of Life Database (BOLD) (OM974109-OM974112 and OM978262-OM978265). Seasonality results indicate no statistically significant difference in the prevalence of tick infestation on cattle during the dry (41.05%) and wet (41.11%) seasons. The DNA of Anaplasma spp. and Theileria/Babesia spp. were detected in (70.33%, n=64) of all tick pools. The detection rate of both Anaplasma and Theileria/Babesia spp. was high in Amblyomma lepidum (25.00%, n=16) followed by Rhipicephalus evertsi (23.44%, n=15) tick pools. The results showed high tick prevalence and abundance on cattle suggesting increased risk of tick- borne disease transmissions and reduced animal production and productivity. Therefore, tick infestation in the study areas highlight the need for strategic tick control approaches.
Diversity of extended-spectrum beta-lactamase genes in avian pathogenic Escherichia Coliin scavenging local chicken in Morogoro Municipality, Tanzania
(Sokoine University of Agriculture, 2016) Armah, Emmanuel Odartei
The poultry industry, especially chicken production has in recent times faced a major set-back due to devastating effects of Extended Spectrum Beta-Lactases (ESBL) producing organisms.This research aimed at investigating the diversity of ESBL genes in avian pathogenic Escherichia coli(APEC) among scavenging local chickens. A total of 400 cloacal and oropharyngeal swabs were obtained, out of which 192 Escherichia coli were isolated. By use of virulence factor profiling, these 192 samples were screened for the presence of 16 virulence factors by multiplex PCR. All 192 samples harbored at least one of the 16 virulence genes and 19 of them carried at least four, making them APEC. The virulence traits ibeA, iss, traT and chuA were observed to lead the chart with percentages of 84.21, 78.95, 63.16 and and 52.63respectively. In the pathogenesis of APEC, Iron acquisition, serum resistance, toxins and invasins were found to be very significant (P<0.05). The antimicrobial profiles of these APEC strains were determined by Kirby-Bauerdisc diffusion test using 10 antimicrobials. These include:augmentin (30μg), imipenem (10μg), cephalothin (30μg), cefotaxime (30μg), ceftazadime (30μg), ceftriaxone (30μg), nalidixic acid (30μg), ciprofloxacin (5μg), gentamycin (10μg) and trimethroprim-sulfamethoxazole(25μg). All APEC strains were found to be resistant to at least one of these drugs, with 10.52% of them being multi-drug resistant. By double-disc synergy test, eight of the APEC isolates were found to be ESBL producers. They were screened for the presence of beta-lactamase genes and the following were present: blaTEM-100%, blaOXA-1 -75.0%, blaCMY-2 62.5%, CTX-M group III (CTX-M-8)-50%, CTX-Mgroup IV (CTX-M -9)-37.5%, CTX-M group I(CTX-M -1,and-15) -12.5% and blaSHV-12.5%. Occurrence of virulence strains of APEC and ESBLs genes are also alarming
The effect of cold storage and cooking procedures on the levels of oxytetracycline residues in beef from Dodoma Region, Tanzania
(Sokoine University of Agriculture, 2018) Mgonja, F. R.
Worldwide, there is an increased use of antimicrobial drugs due to occurrence of diseases of human and animals. The general objective was to study the effect of cooking procedures and cold storage on the levels of Oxytetracycline (OTC) residues in beef in Tanzania. The study used a cross-sectional research design whereby both quantitative and qualitative data were collected from Dodoma region, Tanzania. The household survey was conducted to assess knowledge, attitude and practice on beef consumption among 254 residents. The results show that community based health education and promotion of proper antimicrobial use in animals and preventing drug residues is highly recommended to this population. Beef samples were also analyzed by using High Performance Liquid Chromatography Mass-Spectrometry (HPLC-MS). The quantitative data were analyzed using the IBM Statistical Package for Social Science (SPSS) software version 20 and Epi info version 7. A simple and sensitive method for the detection of OTC levels in ready-to- eat beef by HPLC-MS was modified and validated and used for beef analysis in this study. The advantages of the modified method were cleaning by Supelclean ENVI-carb active coal is cheaper compared to solid phase extraction and samples drying using a stream of liquid nitrogen is cheaper and more than six samples can be dried at a time. For the raw beef, the results indicate that the mean concentration level of OTC was very low (0.69 ± 0.09 ng/g). The boiled and barbecued beef, the mean concentration was 69.4 ±41.93 ng/g and 69.40±38.91 ng/g, respectively. The results indicate that one should not count on heat- treatment to eliminate residues of OTC from beef. The effect of the cold storage on the concentration of OTC residues in beef stored at -20 °C for 60 and 120 days showed that the mean concentration of OTC residues before freezing was 191.71 ± 90.21 ng/g. The mean concentration of OTC after freezing at -20 oC for 60 and 120 days were 166.40 ± 86.49 ng/g and 133.50 ± 83.24 ng/g respectively. These results revealed a significant (p<0.05) reduction of OTC residues of 30% after 60 days and 65% after 120 days of freezing at -20 °C.
The effect of cold storage and cooking procedures on the levels of oxytetracycline residues in beef from Dodoma region, Tanzania
(Sokoine University of Agriculture, 2018) Mgonja, F.
Worldwide, there is an increased use of antimicrobial drugs due to occurrence of diseases of human and animals. The general objective was to study the effect of cooking procedures and cold storage on the levels of Oxytetracycline (OTC) residues in beef in Tanzania. The study used a cross-sectional research design whereby both quantitative and qualitative data were collected from Dodoma region, Tanzania. The household survey was conducted to assess knowledge, attitude and practice on beef consumption among 254 residents. The results show that community based health education and promotion of proper antimicrobial use in animals and preventing drug residues is highly recommended to this population. Beef samples were also analyzed by using High Performance Liquid Chromatography Mass-Spectrometry (HPLC-MS). The quantitative data were analyzed using the IBM Statistical Package for Social Science (SPSS) software version 20 and Epi info version 7. A simple and sensitive method for the detection of OTC levels in ready-to- eat beef by HPLC-MS was modified and validated and used for beef analysis in this study. The advantages of the modified method were cleaning by Supelclean ENVI-carb active coal is cheaper compared to solid phase extraction and samples drying using a stream of liquid nitrogen is cheaper and more than six samples can be dried at a time. For the raw beef, the results indicate that the mean concentration level of OTC was very low (0.69 ± 0.09 ng/g). The boiled and barbecued beef, the mean concentration was 69.4 ±41.93 ng/g and 69.40±38.91 ng/g, respectively. The results indicate that one should not count on heat- treatment to eliminate residues of OTC from beef. The effect of the cold storage on the concentration of OTC residues in beef stored at -20 °C for 60 and 120 days showed that the mean concentration of OTC residues before freezing was 191.71 ± 90.21 ng/g. The mean concentration of OTC after freezing at -20 oC for 60 and 120 days were 166.40 ± 86.49 ng/g and 133.50 ± 83.24 ng/g respectively. These results revealed a significant (p<0.05) reduction of OTC residues of 30% after 60 days and 65% after 120 days of freezing at -20 °C.
Effect of vitamin B6 supplements on glucose tolerance, blood hemoglobin level and body weight in female mice taking combined oral contraceptive
(Sokoine University of Agriculture, 2018) Komba, R.
An increasing number of women worldwide are using some form of contraceptive drugs for family planning including combined oral contraceptives (COC). However, the use of COC has been associated with some adverse effects such as anemia and impaired energy metabolism in some users. A cross-sectional study was, therefore, carried out to investigate the effect of vitamin B6 supplementation on plasma glucose tolerance, hemoglobin levels and body weight using experimental mice model. Forty five adult female mice at their reproductive age (6 - 12 weeks) were randomly divided into three groups of 15 mice each. G1 saved as a control group and received maize basal diet, G2 received 0.061 mg and G3 received 0.061 mg COC together with 0.028 g vitamin B6 at the same time for 56 consecutive days. Glucose tolerance test was taken and hemoglobin levels were tested weekly for 56 days period of the study. Measurement of body weight was done before and after treatment. Results obtained showed that vitamin B6 has significant effect on blood glucose intolerance and hemoglobin level (P < 0.05) and body weight changes (P < 0.05) caused by COC between treated groups. From the study it is recommended that the use of COC by women of reproductive age should be accompanied by concurrent use of vitamin B6 to reduce the effects associated with oral contraceptive.
Effect of women empowerment on sustainable household food security: a case of Monduli district in Tanzania
(Sokoine University of Agriculture, 2022) Muhoze, Linda-Darlene
Food security exists when all people, at all times, have physical and economic access to sufficient, safe, and nutritious food that meets their dietary needs and food preferences for active and healthy life. Food insecurity continues to be a significant problem for public health nutrition in developing and developed countries, and women are the most affected. Similarly, women's empowerment has been used as a strategy to improve household food security and nutrition. Women invest in household food needs, increase household consumption, and improve children's nutritional status compared to men. The objective of this study was to determine the effect of women empowerment on sustainable household food security in Monduli District in Tanzania. A cross-sectional study was conducted between March 2021 and April 2021. A total of 245 households and 491 women between 15 and 49 years of age fully participated in household survey using questionnaire about household food security and women empowerment. Data were analyzed using SPSS for windows (Version 21.0. SPSS Inc., Chicago, IL, USA). The Household Food Insecurity Access Scale (HFIAS) and Minimum Dietary Diversity-Women(MDD-W) revealed that most households were food insecure (73%) and did not reach minimum dietary diversity (95.7%). Women’s Empowerment in Agriculture Index (WEAI) only categorized (16.9%) as empowered women. The low status of women’s empowerment was expressed by their non-involvement in household decision matters, less control over resources, and a low level of education. The positive effect of women empowerment on sustainable household food security in Monduli District (OR=3.15; 95% CI: 1.93-5.13, p<0.05) was determined by using multivariate logistic regression and backward Wald methods. Government policies reienforcement on social mechanisms that allows higher percentage of women to be enrolled in education, gender equality promotion, land ownership, decision- making ,involvement in leadership and programs that access women's participation in off- farm income-generating activities will reduce and prevent household food insecurity in Monduli.
Establishment of long-read nanopore sequencing and proficient nanobodies against peste des petits ruminants virus on the road to develop diagnostic and therapeutic tools
(Sokoine University of Agriculture, 2022) Kinimi, Edson
Peste des petits ruminants virus (PPRV) causes a highly devastating disease of sheep and goats, peste des petits ruminants (PPR), that threatens food security, animal production and the conservation of wild small ruminants. Growing body of evidence suggests that multiple wildlife and atypical host species can be infected with PPRV, posing a serological diagnostic challenge in multi-host environment. Recent studies confirmed that single- domain antigen binding fragments (nanobodies) derived from heavy-chain-only camelid antibodies and nanopore sequencing have proven to be powerful technologies for the development of cost-effective and robust therapeutic and diagnostic tools, respectively. Therefore, the main objective of this study was to generate PPRV-reactive nanobodies in order to set pace for the development of diagnostic and possible therapeutic nanobodies in the future, alongside with establishment of rapid complete genome nanopore sequencing of PPRV. Firstly, a strategy was developed to generate nanobodies against PPRV, whereby an alpaca (Vicugna pacos) was immunized with live attenuated vaccine strain (PPRV/Nigeria/75/1) to raise an affinity-matured immune response in the heavy-chain- only antibody classes. An immune nanobody library with approximately 64 million independent transformants was engineered, of which 100% contained an insert with the proper size of nanobody gene. Following phage display and in vitro affinity selection (biopanning), nine nanobodies that specifically recognise PPRV were identified on enzyme-linked immunosorbent assay. They showed superb potency in identifying rapidly PPRV, which is likely to open a new perspective in the diagnosis and possible treatment of PPRV infection. Secondly, prior to the full genome sequencing of PPRV, nanopore sequencing protocol was tested for amplification and sequencing of PPRV. With this protocol, there were no DNA fragments and nucleotide sequences in the GC-rich region between matrix (M) and fusion (F) genes at the genome position between 4,444 and 5,526. Thus, a tiling multiplex polymerase chain reaction method was developed to amplify the missing DNA fragments. Following redesigning of three pairs of overlapping long read primers and cascade of optimization, the GC rich region was successfully amplified and sequenced (accession numbers: MW580394, MW580395 and MW580396). These three pairs of primers targeting the GC-rich region were used along with other 22 pairs of primers in tiling multiplex PCR for complete PPRV genome sequencing. The resulting PCR amplicons were used for nanopore library preparation and ultimate sequencing. This method has resulted into complete genomes of PPRV, with 15,948 nucleotides long for both isolates that were produced within four hours of sequencing (Accession numbers MW960272 and MZ322753). Phylogenetic analysis of the complete genomes revealed a high nucleotide identity between 96.19 and 99.24% with lineage III PPR viruses currently circulating in East Africa indicating a common origin. The nanopore sequencing platform can be deployed to overcome PPR diagnostic and surveillance challenges, unanticipated variations in virus pathogenicity, circulation of disease in wildlife populations and to service remote and nomadic communities with challenging geographical landscapes. However, further investigations are recommended for PPRV reactive nanobodies especially on diagnostic and therapeutic applications. Once validated, these technologies have great potential for use in the field as rapid and cost-effective tools in context of planned PPR Global Control and Eradication Programme.

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