Department of Animal Biology and Conservation Science (DABCS)
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Item Potential Transmission Of Zoonoses Between The Human-Domestic-Wildlife Interface And Its Implication For Sustainable Health.(University Of Ghana, 2021-09) Amoah, L.A.OZoonoses have been of great public health concern and a global phenomenon that continues to challenge both veterinary and human health systems. The risk of zoonoses is predicted to be higher in domestic settings where animals are constantly in close contact with humans and exposure to zoonotic pathogens is very high. In Ghana, some studies to identify zoonotic diseases transmitted by domestic animals or animals in the wild usually consider either the human-domestic interface or human-wildlife interface. Considering that in recent times diseases continue to emerge from unexpected reservoir hosts and through novel pathways, this study investigated zoonotic diseases that are potentially transmissible by domestic and wild animals to humans across the human-domestic-wildlife interface. It also assessed the awareness and knowledge of owners of companion animals on zoonoses in two human-dominated landscapes. The cross-sectional study involved fieldwork and laboratory processing of biological samples from dogs, cats, and rodents using molecular techniques. Specifically, Polymerase Chain Reaction (PCR) and gel electrophoresis were used to investigate the presence or absence of zoonotic pathogens in biological samples. In addition, questionnaires were administered to owners of companion animals in households and veterinary institutions in designated study areas. Secondary data on zoonotic diseases presented at selected health facilities were also accessed and evaluated to complement the field data. Overall, 404 animals comprising 185(45.8%) dogs, 15(3.7%) cats and 204 (50.5%) rodents were sampled from households, veterinary institutions and selected study sites. In all, seven (7) species of rodents were trapped with Arvicanthis niloticus and Praomys tullbergi identified as the dominant species in the urban and peri-urban areas, respectively. The prevalence of Babesia spp. was the highest (80.7%), followed by Staphylococcus spp. (72.5%) and the least was Ancylostoma spp. (18.1%). For zoonotic helminths (Toxocara canis, Strongyloides stercoralis and Ancylostoma spp.), a prevalence of 30.12% was recorded. The study found significant differences in the prevalence of T. canis (p<0.001), S. stercoralis (p=0.033), and Salmonella spp. (p<0.001), Staphylococcus spp. (p=0.017) and Babesia spp. (p=0.029) between the two human-dominated landscapes. Similarly, there were significant differences in the prevalence of T. canis (p=0.034), S. stercoralis (p<0.001) and Babesia spp. (p<0.001) between the households and veterinary institutions as well as among sampled animals (p<0.05). On the whole, 13.9% of sampled animals had a single or mono-zoonotic infection, while 80.9% were co-infected with multiple zoonotic pathogens. Additionally, medical records from Shai-Osudoku and Pentecost Hospitals revealed that helminth infections were the commonest zoonoses presented by clients, particularly those under 18 years old. Conversely, staphylococcal infections were the highest zoonotic infections reported by clients of the University of Ghana Hospital. Again, 33.8% of 230 respondents who participated in the survey owned companion animals for companionship or as part of the family. Remarkably, 38.9% of the respondents had never dewormed their companion animals. While 62% of respondents had vaccinated their animals, 10.1% did it over a year ago, implying that about 48.1% of these animals were at risk of infectious diseases and could transmit the same to their owners. Furthermore, significant positive associations were found between the educational level of respondents and the frequency of vaccinating pets (rs =0.254, p<0.001) as well as respondents’ knowledge of causes or sources of zoonoses (rs =0.141, p=0.049). On the contrary, there was a significant negative association between the frequency of deworming pets and the main reason for keeping such animals (rs =-0.203, p=0.011) besides the prevention of zoonoses (rs =-0.260, p=0.001). Findings from this study indicate companion animals and rodents are reservoir hosts to zoonotic pathogens of public health importance that can potentially be transmissible to their owners and the community. Also, because these animals are co-infected with multiple zoonotic pathogens, it suggests there could be serious implications for sustainable health, which SDG 3 seeks to achieve. Data from the animal interface and the medical records from the human interface indicate the potential transmission of zoonoses, especially helminthiasis, in the studied communities. In addition, the urban areas were identified to best support the potential transmission of zoonoses contrary to the peri-urban areas. Thus, active surveillance of zoonoses in animals in close contact with humans in our urban and peri-urban communities is urgently required. Again, respondents had some knowledge of zoonotic diseases from companion animals, although most were ignorant of zoonoses from rodents. Findings from the survey indicate that a high proportion of owners of companion animals in the study areas were engaged in activities that predispose them to zoonotic diseases. It is recommended that public education campaigns and awareness creation programmes using a one-health approach should be started in earnest to ensure the effective prevention and control of zoonotic diseases.Item Assessment Of Rearing Technique For The Black Soldier Fly And Termite Collection Technique For Use By Smallholder Poultry And Fish Farmers In Ghana.(University Of Ghana, 2020-11) Boafo, H.A.Insects offer a cheap source of protein for especially smallholder poultry and fish farmers. Insects contain about 40-70 % protein, 35 % fat, and other micro-nutrients. The black soldier fly (BSF) larvae and termites are promising insects that can replace the animal protein component of livestock feed. The full adoption of their use by farmers is however slow due to insufficient scientific data on the production of BSF larvae and termite collection techniques. In this study, the existing production techniques for BSF larvae and collection of termites were evaluated to recommend the most efficient for adoption by smallholder poultry and fish farmers. Six organic substrates (pito mash, millet porridge mash, pig manure, chicken manure, fruit waste, and waste from roots and tubers) known to be suitable for BSF larvae production were evaluated for their suitability as oviposition attractants and larval development. The substrates were first exposed outdoors to measure the quantity of eggs laid on them by naturally occurring BSF females. The quality of the substrate(s) as larval rearing media was also tested by placing a standard amount of egg mass to measure the individual and total weights of prepupae obtained, total number, and development time. The nutritional profile of the prepupae and the substrates were also determined. Furthermore, the production of BSF larvae under natural oviposition (in garden bins) was assessed by varying the rate of loading substrate (pito mash) and the quantities of the substrate on the overall prepupal harvest. The substrate used significantly influenced the quantity of eggs laid and the development of the resulting prepupae but the substrates most favourable for larval development were not the most favoured by gravid BSF for oviposition. In the oviposition tests, millet porridge mash was the most attractive substrate whereas only a few eggs were recovered from the other substrates. All substrates allowed the successful development of larvae but pig manure was more productive than the others. The crude protein content of the larvae ranged between 35 - 43%, with the shortest development time of 16 days. Applying small quantities of substrates at a constant rate (10 kg per week) in garden bins produced higher prepupal yields than larger quantities (20 kg). Unlike BSF larvae, termites cannot be easily produced but are obtained from chippings of mounds or by trapping using containers with filled organic matter. The commonly used termite collection method was assessed to quantify the amount of termites harvested with commonly used organic matter. Furthermore, indigenous knowledge on the use of termites as poultry feed in Ghana and factors affecting its use were assessed. Containers filled with the four commonly used organic matter (mango seed, maize cobs, dried cow dung, yam peels, and their mixtures) were placed on trails of termites to quantify the daily harvest. Surveys were also conducted in four regions in Ghana to collect information, by the administration of questionnaires, on the use of termites as poultry feed, termite species collected, species not used, and collection methods. Samples of termite species mentioned were collected and identified to the genus level. Twenty-three per cent and 19% of farmers mentioned that termites are always or often used to feed poultry whereas 11% never use termites. A binomial regression analysis showed that termite use was affected by region, sex, education, farm size, and income. Termites collected belonged to eight genera, the main ones being Macrotermes, Trinervitermes, and Odontotermes. Five collection methods are used to obtain termites and involve either breaking mounds or using containers as traps. Collection methods vary with species and region and the abundance of termite genera varies with season. Farmers identified some species as poisonous to poultry. A Kruskal-Wallis test showed that there were significant differences in the quantity of termites collected using different substrates for both Odontotermes species and Macrotermes species. A mixture of corn cobs and yam peels yielded the highest dry weight harvest of 14.8 g/day in Macrotermes species. Likewise, the mixture of mango seed and cow dung gave the highest average yield of 19.40 g/day dry weight of Odontotermes species. Termites and black soldier fly larvae are important in indigenous poultry production because they are a readily available and cheap protein source for local farmers.Item Antimicrobial Resistance Of Foodborne Pathogens In Stool Of Diarrhoea Patients In Two Selected Health Facilities And Food From Vendors In Selected Communities In Ghana(University Of Ghana, 2021-12) Dela, H.Foodborne pathogens (FBPs) have been implicated as the cause of so many food poisonings and outbreaks worldwide. Food borne bacteria are the second most common FBP after viruses in causing public health threat due to the gradual emergence of antimicrobial resistance (AMR) in the food chain. Although contaminated food is frequently implicated as the cause of diarrhoeal-related hospitalization, especially during outbreak investigations in Ghana, integrated surveillance has not been conducted to ascertain this fact. This study engaged the various transdisciplinary sectors in human and environmental health to show the holistic approach in understanding the occurrence of AMR of foodborne bacteria in Ghana. Stool of patients attending Maamobi General hospital and Kaneshie polyclinic were collected, and questionnaire administered to patients to understand the risk factors involved in diarrhoea transmission. Ready-to-eat (RTE) food and water were collected from food vendors, palm swabs of food vendors as well as responses on possible risk factors leading to food and water contamination were investigated. Common pathogens isolated in stool were E. coli, E. cloacae, K. pneumoniae in food, while K. pneumoniae, Aeromonas spp. and E. cloacae were isolated from food, water and palm samples from the Maamobi and Kaneshie communities. Among the stool isolates, a total of 69.7% (85/122) Enterobacteriaceae was recovered in the study with an overall ESBL occurrence of 26.5%, predominantly among E. coli (13.2%; 10/76), Klebsiella pneumoniae (35.7%; 5/14) and Proteus mirabilis (57.1%; 4/7). Among the ESBL genes detected, blaTEM (n=14) was common, followed by blaCTX-M (n=13) and blaSHV (n=4). Thirty-four E. coli isolates from the stool samples possessed the heat labile (Lt) gene of Enterotoxigenic E. coli (ETEC) in the stool samples. All the Enterobacteriaceae isolates were resistant to the penicillins and aminoglycosides apart from E. coli which showed reduced susceptibility to both drug classes. The food items showed the common occurrence of E. cloacae (16.8%), Citrobacter spp (10.1%), E. faecalis (7.8%), Pseudomonas spp (6.7%) and K. pneumoniae (4.0%). Resistance genes and Diarrhoeagenic E. coli (DEC) showed among two C. freundii isolates possessing the blaTEM gene and one E. coli possessing the Lt gene of ETEC. Over 50% resistance to penicillins and Rifampicin among most of the Enterobacteriaceae (E. cloacae, Citrobacter spp, Aeromonas spp), and non- Enterobacteriaceae (E. faecalis) were observed among the isolates recovered. Common pathogens recovered in water and palm were K. pneumoniae, Aeromonas spp. and E. cloacae with one K. pneumoniae isolate from the palm of a food vendor possessing the blaTEM gene. Resistance to majority of the antibiotics among the Enterobacteriaceae as well as non-Enterobacteriaceae (E. faecalis and Pseudomonas spp) was observed. Mean Total Plate Counts (TPC) of 1.4 X 105 CFU/g) of unsatisfactory interpretation was observed in stew as well as mean Total Coliform Counts (TCC) of 2.2 X 105 CFU/g and 1.7 X 105 CFU/g occurring in stew and ‘waakye’ respectively. Over 50% of all water types examined for mesophilic bacteria by TPC and TCC were considered impure with all palm swabs showing a 100% purity. Environmental samples (food and water) showed the effect of non-adherence to proper hand hygiene on food and water contamination during street food vending and the need for targeted education and enforcement of food safety policies in the country. These findings confirm the existence of AMR FBPs posing a threat to food safety due to the difficult to treat infections in case of transmission. Similar resistance to beta-lactams, Tetracyclines, Azithromycin and Penicillinase antibiotics among the clinical and environmental isolates shows common FBP transmission patterns which warrants the need for more AMR integrated surveillance in the food chain prior to consumption.Item Diversity And Some Aspects Of The Bioecology Of Aphids On Cabbage And Their Association With A Novel Necrotic Disease(University Of Ghana, 2021-12) Echep, F.E.Agriculture serves as a significant source of livelihood for many small-scale farmers, who account for the greatest share of agricultural production. Of the numerous varieties of exotic vegetables grown in Ghana, cabbage (Brassica oleracea var. capitata) is widely grown to meet the high demand of the ever-growing urban market, due to the many health benefits associated with its consumption. However, the devastating impacts of pests such as aphids and diseases on cabbage have resulted in significant yield losses. Aphids achieve this fate by developing resistance to many insecticides by rendering them ineffective, heavy infestations, development of sooty mould and transmission of viral diseases. Management interventions have been largely dependent on calendar spray regimes, with little or no knowledge on pest species and bioecology. While these interventions are an integral component of an integrated pest management approach on cabbage, identifying pest species, understanding their bioecology is important in the development and success of these pest management interventions. The current study sought to understand the diversity and bioecology of aphids on cabbage, and their role in the aetiology of a novel necrotic disease in Ghana. Surveys were conducted from 2019 to 2020, in nine regions of Ghana across five agroecological zones, noted for the production of cabbage to determine aphid species associated with cabbage and their distribution. Their regional abundance and spatiotemporal variation across agroecological zones were also assessed. In each region, cabbage farms in three districts were selected for the survey. Sampling was done by randomly sampling 20 plants per farm and aphids were counted, and some collected into vials containing 70% alcohol for identification. Two aphid species were identified to occur on cabbage, i. e. Lipaphis erysimi pseudobrassicae and Myzus persicae, with the former being the more abundant in all the regions. The highest aphid distribution and abundance was recorded in the Southern part of the country. There was significant variation in the population of these aphids across the different agroecological zones, with the highest recorded in the Deciduous Forest and Coastal Savannah zones. Aphid abundance was influenced by agroecological zones, vegetative cover and climatic conditions. The distribution of L. e. pseudobrassicae and M. persicae, in Ghana could not be ascertained by manually sampling all cabbage growing regions, hence, the rationale for the use of species distribution models to understand their spatial patterns and the underlying contributing climatic factors to map their suitable habitats. Occurrence data collected during the survey was used to determine aphid spatial distribution. A tree-based supervised machine learning algorithm, Random Forest was used to infer the underlying contributing factors, and to map the habitat suitability of both aphid species. Temperature and isothermality were the most important weather variables that affected the distribution of L. e. pseudobrassicae and M. persicae. The Southern Ghana was most suitable for the occurrence of both aphid species. Species distribution models can inform researchers about particular ecological adaptations of aphids and other insect pests in targeted areas, which can optimize efficiency and cost in pest control programmes.Item Association Between Single Nucleotide Polymorphisms In Insulin-Like Growth Factor 1 And Insulin-Like Growth Factor 2 Genes And Growth Traits, And Survivability In Three Local Chicken Ecotypes Of Ghana(University Of Ghana, 2022-07) Kanlisi, R.A.Local chickens have comparatively smaller body sizes and slower growth rates. As a result, many smallholder farmers often tend to cross them with heavier breeds of chicken with the aim of improving their growth traits, a process that can lead to the dilution of their genetic composition and subsequent loss of important adaptive traits. Insulin-like growth factor 1 (cIGF1) and Insulin-like growth factor 2 (cIGF2) hormones have been widely reported to be associated with embryonic and post-hatch growth and development of chicken and the genes that code them have also been reported as candidate genes for growth and carcass traits of chicken. This research was conducted with the aim of assessing the growth, carcass, and survivability traits of three chicken ecotypes of Ghana, to analyze the diversity of the cIGF1 and cIGF2 genes in these chicken ecotypes and assess the extent to which polymorphisms in these genes influence the growth and carcass traits of the three chicken ecotypes of Ghana. Eggs of the Forest (FO), Interior Savannah (IS) and Coastal Savannah (CS) chicken ecotypes of Ghana were obtained from breeder stocks at the Livestock and Poultry Research Center (LIPREC) of the University of Ghana. These eggs were hatched and reared by ecotype up till 22 weeks of age. During this period, the body weights were taken fortnightly up till the end of the experiment after which the chickens were all euthanized, and some carcass traits measured. The quantity of feed consumed per bird during this period and the number of deaths were recorded daily. From these measurements, growth rates, survivability, Feed Conversion Ratios, and carcass traits were computed. DNA was also extracted from the chicken, and Polymerase Chain Reaction used to amplify targeted regulatory and exonic regions of the two genes. Thereafter, Restriction Fragment Length Polymorphism was used to detect single nucleotide polymorphisms (SNPs) in the PCR amplicons. These polymorphisms were confirmed with the aid of sanger sequencing and sequence alignments. The results of this research showed that the IS and FO chicken ecotypes were heavier and grew at a faster rate than the CS ecotype. However, the FO ecotype had significantly (p<0.05) higher breast weight and breast yield than the IS and CS chicken ecotypes. The results also showed that the CS ecotype had the highest survival rate under intensive management conditions while the IS ecotype had the lowest survival rate. The three chicken ecotypes could therefore be used together in a breed improvement programmes that seek to enhance the growth and carcass traits of local chickens of Ghana by leveraging the higher growth rates of the Interior savannah chicken ecotype, the higher breast yield of the Forest chicken ecotype and the higher survival rate of the Coastal savannah chicken ecotype. The RFLP digestion of cIGF1 and subsequent sequencing revealed a HinfI C>A single nucleotide polymorphism (SNP) in the 5’ UTR, a PstI T>C SNP in the promoter of the 5’ flanking region, and a BstBI T>C SNP in the 3’UTR, while a NlaIII C>T SNP was identified in exon 3 of cIGF2. At the HinfI C>A locus, the AC heterozygote was the predominant genotype amongst the FO and CS ecotypes, while the CC genotype was predominant in the IS ecotype. The C allele had the highest frequency amongst all the three chicken ecotypes. The observed heterozygosity values were higher than the expected heterozygosity values in the FO and CS ecotype populations. There was no significant association of the HinfI C>A SNP with body weights, weight gain and the carcass traits. This SNP locus may therefore not be an ideal molecular marker for selection to improve body weight and carcass traits in Ghanaian local chickens. At the PstI T>C locus, the CT heterozygote was the most predominant genotype among the three Ghanaian chicken ecotypes, with the T allele having the highest frequency. The observed heterozygosity amongst the FO and CS chicken ecotypes was higher than the expected heterozygosity. PstI T>C was associated with body weights at hatch and at 16 and 22 weeks of age (p<0.05) but it did not influence the carcass traits that were investigated. PstI T>C could therefore be a potential molecular marker for use in marker-assisted selection for the improvement of body weight in the local chicken ecotypes of Ghana. At the BstBI T>C locus, CT heterozygote was the common genotype among the three chicken ecotypes while the C allele had the highest frequency. The observed heterozygosity of this polymorphism was higher in the FO and CS ecotypes than in the IS ecotype. BstBI T>C was significantly (p<0.05), associated with body weights at hatch, 2, and 10 weeks of age, but it was not associated with any of the carcass traits studied. This SNP locus could be useful in future marker-assisted selection for the improvement of body weight traits in the local chicken ecotypes of Ghana. An analysis of the diversity of the NlaIII C>T SNP showed that the AB heterozygote was the predominant genotype amongst the FO and CS ecotypes while the BB genotype was predominant in the IS ecotype. The A allele had the highest frequency in the FO ecotype, while the B allele was the predominant allele in the CS and IS ecotypes. The FO and IS ecotypes had lower observed heterozygosity values than the expected heterozygosity values. However, in the CS ecotype, the observed heterozygosity was higher than the expected heterozygosity. NlaIII C>T had no significant effect on body weights and any of the carcass traits studied. NlaIII C>T would therefore not be a good molecular marker for use in selection to improve body weight of chicken ecotypes in Ghana. The results of this research suggest that PstI T>C and BstBI T>C could be useful molecular markers for the improvement of body weight in future marker-assisted breeding programmes of local chicken ecotypes in Ghana. However, HinfI C>A, PstI T>C, BstBI T>C and NlaIII T>C SNPs may not be the ideal molecular makers for carcass traits improvement among the three chicken ecotypes of Ghana. These studies conclude that genetic improvements in the economic traits of importance of the local chicken ecotypes of Ghana such as body weight could be carried out by taking advantage of the higher growth rates of the IS chicken ecotype, the higher breast yield of the FO chicken ecotype and the higher survival rate of the CS chicken ecotype. Furthermore, the PstI T>C and BstBI T>C SNPs could be considered as molecular markers for the improvement of body weight in future marker-assisted breeding programmes of local chicken ecotypes in GhanaItem Foraging Ecology of Sanderling Calidris Alba on the Western Coast of Ghana(University of Ghana, 2018-12) Quartey, J.K.Migration is an important process in the annual cycle of shorebirds that enables them to escape unfavourable conditions at certain times of the year and provides them opportunity to breed in one area and spend the non-breeding season in other latitudes. The selection of a suitable non-breeding habitat by migrants is dependent on a number of factors which define the quality of the habitat, namely: levels of disturbances, predatory risk, suitable environmental and climatic conditions such as depth and temperature of water, abundance and availability of food. The Esiama beach on the Ghana coast is important for sanderlings of the East Atlantic Flyway during the non-breeding season, supporting 40-70% of all sanderlings along the Ghana coast. The overall aim of this study was to investigate and document the foraging ecology of sanderlings on the western coast of Ghana; and using the species as a model, describe and assess the quality of Esiama beach as a suitable and preferred non-breeding site for sanderlings in Ghana. Specifically, this study sought to measure the variations in the distribution, availability and quality of benthic macroinvertebrates as prey for sanderlings and assess the spatio-temporal variation in the distribution of sanderlings in relation to food availability. The study also focused on describing foraging behaviour and strategies employed by sanderlings, determine prey preference and evaluate the impact of human disturbances and other pressures on the foraging behaviour of sanderlings. Data for this study were obtained through direct field observations of foraging birds, benthic macroinvertebrate sampling, mist netting, faecal collection; laboratory analysis of macroinvertebrates and estimation of biomass; as well as experiments to determine intake rates and prey preference of captive sanderlings. A total of 62,000 macroinvertebrates belonging to four Phyla: Mollusca (Donax pulchellus, D. rugosus, Hastula aciculina and Agaronia acuminata), Arthropoda/ Crustacea (Excirolana chiltoni, Emerita talpoida, Mysid shrimp), Annelida (Glycera spp., Nereis sp.) and Nemertea were recorded in benthic samples. Donax pulchellus, E. chiltoni and Glycera spp. constituted 91.66%, 6.45% and 1.40% respectively of all individuals in benthic samples. About 95.0% of all macroinvertebrates in benthic samples were present in the top 3 cm depth and therefore were considered available to sanderlings. About 99.18% of all D. pulchellus individuals were available to sanderlings. About 99.68% of all available macroinvertebrates were distributed within the low- and inter-tidal zones and was dominated by D. pulchellus. Excirolona chiltoni was the most abundant prey within the high tide zone. The diet of sanderlings from the analysis of faecal samples was made up of bivalves, gastropods, polychaetes, isopods and fish. Donax pulchellus was the most abundant prey found in droppings of sanderlings, occurring in about 78.0% of all faecal samples and constituted of 79.0% of the total number of prey items found in faecal samples. The mean length, biomass and quality of D. pulchellus were 6.9 ± 1.7 mm, 1.42 ± 0.04 mg AFDMflesh and 1.04 kJ/ g and for E. chiltoni 5.2 ± 1.4 mm, 1.44 ± 0.06 mg AFDMflesh and 7.75 kJ/g. There were two recruitment periods for D. pulchellus; between July – October and January – March. Peak densities of D. pulchellus occurred in August – October and January – March, which explained the occurrence of high numbers of sanderlings along the beach, coinciding with the autumn and spring migrations respectively. Spatially, densities of D. pulchellus declined towards the estuaries (p < 0.001) with mean densities up to 15,509 individuals/ m2 whiles densities of E. chiltoni increased towards the Ankobra estuary (p < 0.001) with mean densities up to 960 individuals/ m2. The spatial distribution of sanderlings was explained by the densities of D. pulchellus (p < 0.001), but not E. chiltoni (p = 0.91). Sanderlings spent 60.45%, 36.93%, 1.15% and 1.48% of the 12-hour day time foraging, resting, in locomotion and engaged in comfort activities respectively. The time-activity budgets of sanderlings could be explained by the tidal cycle, diurnal time, number of sanderlings on the beach and density of prey. For example, more sanderlings foraged between 0600 – 0900 GMT and 1500 – 1700 GMT which coincided with 2 hours before and after high tide. Such observation suggests that sanderlings take an optimal course of foraging action, maximizing foraging opportunities presented by tidal action. Three foraging methods were described for sanderlings in exploiting their prey: pecking, probing and sewing. Pecking was a visual foraging method whereas probing and sewing were tactile methods. Sanderlings in captivity were also observed to use sewing methods to search for the appropriate prey size. Foraging rates of sanderlings varied with prey densities and sanderling numbers. For example, sanderlings pecked more when density of prey was high (25.24 ± 19.29 pecks/min) than when prey densities was lower (15.19 ± 13.74 pecks/min; p < 0.0001), and also when sanderlings were abundant on the beach (25.04 ± 19.01 pecks/min) than when there were fewer sanderlings (17.66 ± 16.16 pecks/min; p < 0.0001). Sanderlings also spent more time probing when bird numbers were high (9.80 ± 12.74 s/min) than when they were low (6.23 ± 8.19 s/min). Foraging rates of sanderlings increased with flock size below 28 individuals (p < 0.0001), beyond this threshold, foraging rates declined (p = 0.04). Due to competition for limited resource. Foraging rates of sanderlings also increased with nearest neighbour distance for conspecifics foraging in flock size greater than 28 individuals. Highest foraging rates were observed for sanderlings immediately upon arrival on the beach and peak sanderling count periods. The variation in foraging rates could be explained by competition for food in line with actual or apparent decline of prey densities. There was no significant difference in foraging rates in the field (23.68 ± 18.54 pecks/min) and in captivity (25.13 ± 14.03 pecks/min; W = 3810, p = 0.37). The intake rate of D. pulchellus by sanderlings in captivity was 1.61 ± 0.73 individuals/ min but varied between small size (1.61 ± 1.03 individuals/min) and medium size (0.44 ± 0.36 individuals/min). The estimated biomass of prey consumed in a 12-hour period from faecal samples were: D. pulchellus (0.72 ± 0.62 g AFDM), E. chiltoni (0.49 ± 0.42 g AFDM) and Glycera spp. (0.36 ± 0.26 g AFDM) making a total of 1.57 ± 0.96 g AFDM. The biomass of E. chiltoni was likely to be underestimated due to the time of faecal collection. Therefore, University of Ghana http://ugspace.ug.edu.gh using estimates of intake rates of isopods from literature, a value of 7.34 g AFDM was estimated as the total biomass consumed in a 12-hour period. Sanderlings showed preference for E. chiltoni to D. pulchellus (p = 0.01). Between small and medium size D. pulchellus, sanderlings preferred the former (p < 0.001). Several disturbance activities were observed along the beach: human related activities (74.0%); predators such as yellow-billed kite Milvus migrans parasitus (13.0%) and dogs (6.0%); scavengers (5.0%) and engine-driven machines (2.0%). Out of the proportion of human-related disturbances, fishing activities, passers-by, shellfish harvesting and recreational activities accounted for 45.0%, 37.0%, 14.0% and 4% respectively of the observed activities. The mean encounter rate of fishing activity was 0.5±0.3 activity/km with an average human density of 21±11 individuals/activity. The spatial distribution of sanderlings was related to distribution of D. pulchellus (p < 0.05), human densities (p < 0.001) but not E. chiltoni (p = 0.6). The impact of the disturbances along the beach by sanderlings was determined using the Minimal Approach Distance (MAD) method. Sanderlings could tolerate approaching humans up to a distance of 25.51±10.03 m and kites up to a height of 11.93 ± 6.29 m beyond which they showed signs of being disturbed. Multiple linear regression of all possible factors indicated that the MAD for sanderlings to humans depended on flock size and width of the beach for foraging sanderlings (R2 = 0.27, df=5, p = 0.0002). The findings of this study provide additional information on the foraging ecology of sanderlings along the Esiama beach, describe the quality of the Esiama beach as a habitat for sanderlings and make a case for protection of the Esiama beach and associated Amansuri wetlands as a Ramsar site (i.e. an internationally important wetland). University of Ghana http://ugspace.ug.edu.ghItem Forest and Water- Birds as Reservoirs of Some Pathogenic and Antimicrobial-Resistant Bacteria(University of Ghana, 2018-12) Sawyerr, L.Wild birds, particularly, migratory species can move from one place to the other within a short time. Their ability to fly over distances presents them with the potential to pick and spread pathogens. Despite their potential to acquire and spread pathogens, not many researchers have investigated their gastrointestinal flora. Apparently healthy birds have received little attention when it comes to surveillance for the occurrence of enteric pathogens. Many of the studies that have been conducted have focussed on a few species of birds or were conducted in the event of disease outbreaks with high mortality. In this study, apparently healthy wild birds were investigated for gram-negative enteric bacteria. Gram-negative bacteria were considered because they are the commonest in the environment. Similarly, enteric pathogens were considered because they can be found along the gastrointestinal tract and are mainly obtained from the diet of the bird. The birds were sampled from the Ankasa Conservation Area, Esiama beach and the Densu Delta Ramsar Site. Birds that were sampled from the Ankasa Conservation Area were forest birds and birds from the Densu Delta Ramsar Site and Esiama beach were waterbirds. Overall, 15 gram-negative enterobacteria genera were obtained from 377 cloacal swabs from the sampled birds. The overall prevalence of gram-negative bacteria in the birds was 61.8% (233/377). The prevalence in forest and water- birds were 65.2% (90/138) and 59.8% (143/239) respectively. Common genera of bacteria isolated from the birds were Escherichia (22.3%), Yersinia (19.4%), Enterobacter (12.2%) and Klebsiella (11.4%). On the whole, the most frequently isolated genus was Escherichia, which was obtained from 20 species of sampled birds. However, in the waterbird samples, the genus Yersinia was frequently isolated. The genera Ochrobactrum (0.5%), Morganella (0.3%), Achromobacter (0.3%) and Alcaligenes (0.3%) were the least isolated. Though wild birds do not use antimicrobial agents and rarely come into contact with antimicrobials in the wild, bacteria isolated from 15.5% of the birds were resistant to Colistin by the agar dilution method. The prevalence of Colistin-resistant bacteria in the forest and water- birds were 10% (9/90) and 18.8% (27/143) respectively. Colistin-resistant isolates were recorded in seven forest bird species and six waterbird species. Similarly, the overall prevalence of Ciprofloxacin-resistant bacteria in the birds was 41.7% (97/233). The prevalence in forest and water- birds were 35.6% (32/90) and 41.3% (59/143). Ciprofloxacin-resistant isolates were recorded in 11 forest bird species and nine waterbird species. When the Colistin-resistant isolates (106) were subjected to multidrug resistance tests by the disc diffusion method, the prevalence of gram-negative bacteria resistant to antimicrobial agents tested were Ampicillin (73.6%), Streptomycin (50.9%), Oxytetracycline (52.8%) and Ciprofloxacin (8.5%). Colistin and Ciprofloxacin- resistant isolates were further investigated for plasmid-mediated resistance genes. Plasmid mediated polymyxin-resistant genes mcr-1, mcr-2, mcr-3, mcr-4 and, mcr-5 were recorded in bacteria isolated from the birds. The mcr-3 gene was the most prevalent polymyxin-resistant gene in this study and was recorded in bacterial isolates from both forest and water- birds. The mcr-1 gene was recorded in bacterial isolate from a forest bird, while mcr-2, mcr-4 and mcr-5 were recorded in bacterial isolates from waterbirds. Similarly, plasmid-mediated quinolone-resistant genes (qnrB, qnrD, qnrS and qnrVC) were recorded in bacteria isolates from sampled birds. The prevalent gene was qnrVC and occurred in 9.8% (16/164) of the Ciprofloxacin-resistant isolates. Moreover, bacterial isolates belonging to the gram-negative bacteria genera Salmonella, Escherichia, Yersinia and Shigella were examined for the occurrence of the species Yersinia pseudotuberculosis, Yersinia enterocolitica, Shigella flexneri, Shigella dysentariae, Enterotoxigenic E. coli, and Salmonella enterica. These species are known to cause severe diarrhoeal infections in humans. Only enterotoxigenic E. coli (ETEC) was detected among the isolates. The prevalence of ETEC was 38.6% and 62.5% in forest and water- birds respectively. Phylogenetic analysis of all E. coli isolates obtained from this study showed that 60.6% of the E. coli isolates belonged to virulent phylogenetic groups, while 39.4% belonged to commensal groups. The results obtained from this study suggest that wild birds are reservoirs of enteric bacteria and may serve as sources of infection to humans, domestic animals, and other wild animals. The findings also suggest that wild birds harbour antimicrobial-resistant bacteria that carry plasmid-mediated genes. These genes are reported to have the potential to confer resistance to other bacteria isolates. Evidence from the study shows that enterotoxigenic E. coli occurs in the wild birds and these birds may serve as sources of infection to humans. In conclusion, apparently healthy wild birds harbour pathogenic gram-negative bacteria, though they may seem asymptomatic. Therefore, is it important to monitor wild birds for the occurrence of pathogenic bacteria as well as antimicrobial-resistant bacteria. Although prevalence may be low, the potential to spread pathogens is considerable. From a conservation standpoint, the occurrence of antimicrobial-resistant bacteria could hamper conservation efforts as birds carrying resistant bacteria could serve to disperse bacteria between widely separated locations and from hotspots to vulnerable populations.Item Forest and Water- Birds as Reservoirs of Some Pathogenic and Antimicrobial-Resistant Bacteria(University of Ghana, 2018-12) Sawyerr, L.Wild birds, particularly, migratory species can move from one place to the other within a short time. Their ability to fly over distances presents them with the potential to pick and spread pathogens. Despite their potential to acquire and spread pathogens, not many researchers have investigated their gastrointestinal flora. Apparently healthy birds have received little attention when it comes to surveillance for the occurrence of enteric pathogens. Many of the studies that have been conducted have focussed on a few species of birds or were conducted in the event of disease outbreaks with high mortality. In this study, apparently healthy wild birds were investigated for gram-negative enteric bacteria. Gram-negative bacteria were considered because they are the commonest in the environment. Similarly, enteric pathogens were considered because they can be found along the gastrointestinal tract and are mainly obtained from the diet of the bird. The birds were sampled from the Ankasa Conservation Area, Esiama beach and the Densu Delta Ramsar Site. Birds that were sampled from the Ankasa Conservation Area were forest birds and birds from the Densu Delta Ramsar Site and Esiama beach were waterbirds. Overall, 15 gram-negative enterobacteria genera were obtained from 377 cloacal swabs from the sampled birds. The overall prevalence of gram-negative bacteria in the birds was 61.8% (233/377). The prevalence in forest and water- birds were 65.2% (90/138) and 59.8% (143/239) respectively. Common genera of bacteria isolated from the birds were Escherichia (22.3%), Yersinia (19.4%), Enterobacter (12.2%) and Klebsiella (11.4%). On the whole, the most frequently isolated genus was Escherichia, which was obtained from 20 species of sampled birds. However, in the waterbird samples, the genus Yersinia was frequently isolated. The genera Ochrobactrum (0.5%), Morganella (0.3%), Achromobacter (0.3%) and Alcaligenes (0.3%) were the least isolated. Though wild birds do not use antimicrobial agents and rarely come into contact with antimicrobials in the wild, bacteria isolated from 15.5% of the birds were resistant to Colistin by the agar dilution method. The prevalence of Colistin-resistant bacteria in the forest and water- birds were 10% (9/90) and 18.8% (27/143) respectively. Colistin-resistant isolates were recorded in seven forest bird species and six waterbird species. Similarly, the overall prevalence of Ciprofloxacin-resistant bacteria in the birds was 41.7% (97/233). The prevalence in forest and water- birds were 35.6% (32/90) and 41.3% (59/143). Ciprofloxacin-resistant isolates were recorded in 11 forest bird species and nine waterbird species. When the Colistin-resistant isolates (106) were subjected to multidrug resistance tests by the disc diffusion method, the prevalence of gram-negative bacteria resistant to antimicrobial agents tested were Ampicillin (73.6%), Streptomycin (50.9%), Oxytetracycline (52.8%) and Ciprofloxacin (8.5%). Colistin and Ciprofloxacin- resistant isolates were further investigated for plasmid-mediated resistance genes. Plasmid-mediated polymyxin-resistant genes mcr-1, mcr-2, mcr-3, mcr-4 and, mcr-5 were recorded in bacteria isolated from the birds. The mcr-3 gene was the most prevalent polymyxin-resistant gene in this study and was recorded in bacterial isolates from both forest and water- birds. The mcr-1 gene was recorded in bacterial isolate from a forest bird, while mcr-2, mcr-4 and mcr-5 were recorded in bacterial isolates from waterbirds. Similarly, plasmid-mediated quinolone-resistant genes (qnrB, qnrD, qnrS and qnrVC) were recorded in bacteria isolates from sampled birds. The prevalent gene was qnrVC and occurred in 9.8% (16/164) of the Ciprofloxacin-resistant isolates. Moreover, bacterial isolates belonging to the gram-negative bacteria genera Salmonella, Escherichia, Yersinia and Shigella were examined for the occurrence of the species Yersinia pseudotuberculosis, Yersinia enterocolitica, Shigella flexneri, Shigella dysentariae, Enterotoxigenic E. coli, and Salmonella enterica. These species are known to cause severe diarrhoeal infections in humans. Only enterotoxigenic E. coli (ETEC) was detected among the isolates. The prevalence of ETEC was 38.6% and 62.5% in forest and water- birds respectively. Phylogenetic analysis of all E. coli isolates obtained from this study showed that 60.6% of the E. coli isolates belonged to virulent phylogenetic groups, while 39.4% belonged to commensal groups. The results obtained from this study suggest that wild birds are reservoirs of enteric bacteria and may serve as sources of infection to humans, domestic animals, and other wild animals. The findings also suggest that wild birds harbour antimicrobial-resistant bacteria that carry plasmid-mediated genes. These genes are reported to have the potential to confer resistance to other bacteria isolates. Evidence from the study shows that enterotoxigenic E. coli occurs in the wild birds and these birds may serve as sources of infection to humans. In conclusion, apparently healthy wild birds harbour pathogenic gram-negative bacteria, though they may seem asymptomatic. Therefore, is it important to monitor wild birds for the occurrence of pathogenic bacteria as well as antimicrobial-resistant bacteria. Although prevalence may be low, the potential to spread pathogens is considerable. From a conservation standpoint, the occurrence of antimicrobial-resistant bacteria could hamper conservation efforts as birds carrying resistant bacteria could serve to disperse bacteria between widely separated locations and from hotspots to vulnerable populations.Item Characterization of Onchocerca Volvulus Response to Ivermectin Treatment and Identification of Single Nucleotide Polymorphisms Associated With These Responses in Some Onchocerciasis Endemic Regions in Ghana(University of Ghana, 2016-12) Frempong, K.K.In Ghana, onchocerciasis control with mass ivermectin treatment began in 1987. Despite over two decades of interventions, the disease remains persistent with reports of sub-optimal/poor parasite responses to the drug. Some treated patients are observed with higher microfilarial repopulation rates in skin than expected, an indication of sub-optimal response. Although ivermectin is still effective in reducing microfilaridermias, it is uncertain if its embryostatic effect has been compromised. This thesis was to assess the impact of the first 3 years of biannual treatment strategy in Ghana and quantify responses to standard dose of ivermectin in hosts’ skin, assess the drug’s effect on the reproductive capacities of adult female worms and explore any genetic changes in beta-tubulin (β-tub) and P-glycoprotein (P-gp) genes that are believed to be associated with poor response phenotype. The study was carried out in 10 sentinel communities which had received between 15 and 24 years of annual treatment. A community-wide skin snipping was performed on 956 consenting adults aged ≥20 years to assess the community prevalence and intensity of microfilariae. A cohort of 217 participants who were microfilaria positive and/or had palpable nodules at baseline were followed up over the first two rounds of biannual treatment to estimate the rates of microfilarial repopulation. Nodulectomies were performed on consenting participants three months after the third round of treatment. Adult worms (male and female) were isolated from nodules using the collagenase technique. Embryogram analyses were performed and adult female worms classified into three response groups (good, intermediate and poor). DNA was extracted from 60 worms which accurately fitted the response classifications. Polymerase Chain Reaction (PCR) amplifications were performed using specific primers for one region within β-tub and 6 regions within P-gp genes. The amplified products were sequenced and analysed for single nucleotide polymorphisms (SNPs) associated with these responses. The biannual treatment substantially reduced infection intensities in most communities, although infections were detected in all communities even after 4 or 5 rounds of biannual treatments. Asubende, Kyingakrom and New-Longoro communities were identified (all having been previously recognized as responding sub-optimally to ivermectin) with statistically significantly high microfilarial repopulation rates. A total of 225 nodules were excised from 106 participants with an average of about 2 female worms and 1 male worm per nodule. A significantly higher number of female worms (72%) were observed without normal/viable microfilariae (P < 0.0001). There were no clear associations between the years of annual ivermectin treatment prior to biannual and microfilarial repopulation rates or reproductive status of female worms. A multiple sequence alignment showed 10 SNPs that were polymorphic and analysed for any associations. Three of these SNPs were statistically significantly associated with a poor response phenotype i.e. two at positions 1308C/T (P = 0.016) and 1545A/G (P = 0.008) within β-tub and one at position 5546A/G (P = 0.023) within P-gp. Within the β-tub, there was selection at position 1308C/T and some genotypes were present in good responders but absent in poor responders, vice versa. The heterozygosity was found to be reduced within worms sampled from Kintampo/Pru districts compared to those from Kpandai district. Although the biannual treatment in Ghana has made an impact, transmission still exists within some communities, and this is suggested to be driven by a few sub-optimally responding female worms in each community. These sub-optimal responses are also associated with some level of genetic changes. Regular monitoring of parasite responses to ivermectin treatment is necessary to avoid a completely resistant population emerging. Based on these findings, it is uncertain if increasing the frequency of ivermectin treatment (in Ghana) will be sufficient to meet the World Health Organization’s goals of onchocerciasis elimination by 2025.Item Ecology of Fruit Bats in Ghana, With Special Focus on Epomophorus Gambianus, And the Role of Fruit Bats in Zoonotic Disease Transmission(University of Ghana, 2017-07) Amponsah-Mensah, K.Bats are a unique order of mammals that are known to play vital roles in ecosystems and are also an important source of emerging zoonotic diseases of significant health importance. Knowledge of the ecology for several species, particularly fruit bats (Pteropodidae) is lacking and this limits our understanding of the role bats play in ecosystem functioning, disease transmission and hinders their management and conservation. The overall aim of this study was to describe the ecology of fruit bats in Ghana with particular reference to Epomophorus gambianus, and the role fruit bats play in possible emergence and transmission of zoonotic diseases. Specifically, this study sought to document the distribution of fruit bats in Ghana, determine demographic parameters and reproductive characteristics and describe aspects of the roosting and feeding ecology of E. gambianus. The study also focused on providing further serological evidence for prevalence of zoonotic viruses in fruit bats in Ghana and identifies human bat interactions that can serve as potential routes for zoonotic disease transmission. The study used direct field observations involving roost searches and mapping, mist netting, radio-tagging, faecal collection and plant phenological studies, as well as an innovative citizen science approach and questionnaire administration to collect empirical and biological data to address the aims of the study. Ten of the 13 species of fruit bats reported for the West African sub-region were recorded in this study. These were Epomophorus gambianus, Eidolon helvum, Nanonycteris veldkampii, Epomops franqueti, Epomops buettikoferi, Hypsignathus monstrosus, Lissonycteris angolensis, Megaloglossus woermanni, Rousettus aegyptiacus and Micropteropus pusillus. Roosts belonging to five species of fruit bats were identified in 74 different locations across the country. This is the first study that has attempted the nationwide description of the distribution of roost sites for fruit bats in Ghana. Most of the colonies identified occurred in close proximity to humans and in densely populated places. Majority of the roosts identified belonged to E. helvum and E. gambianus and several roosts were identified for the first time, although they had been occupied or used intermittently by bats for ten or more years. Trapping of bats at eleven different sites showed that E. gambianus and E. helvum were the most common fruit bat species in Ghana. Out of the 6,132 bats captured the two species accounted for 75%. By analyzing faecal and ejecta pellets collected under day roosts and from captured bats over a two year period, E. gambianus was found to utilise fruits and flowers from 35 plant species, including some economically important ones. Monthly monitoring of plants for fruit and flower abundance indicated that fruits were relatively available throughout the year but in varying quantities, with peaks during the rainy seasons. Flowers were mostly abundant during the dry season and potentially contributed up to 79% of the diet of bats during this season. Roost selection analysis showed that E. gambianus was more likely to select trees species such as Magnifera indica, Ficus sp., Azadirachta indica, and Polyalthia longifolia trees for roosting, and showed preference for bigger, taller trees. Roosting sites were also more likely to be closer to buildings and less likely to occur in areas with high tree densities. Roosts with higher number of bats, and were more frequently occupied by bats were more likely to be utilised as maternal roosts. Radio-tracking of 60 bats suggested a fission-fusion roosting system in E. gambianus. Female bats used a relatively smaller roosting area compared to males. Based on the proportion of adult females detected to be pregnant and lactating for each month, the reproductive rate of E. gambianus was estimated to vary between 0.56-1.0 offspring per female per reproductive season, while that for M. pusillus varied between 0.80 to 1.0 offspring per female per reproductive season. This study confirmed the reported reproductive chronology of E. gambianus and M. pusillus as continuous bimodal polyoestry, with post partum oestrus in Ghana. There was strong synchrony in parturition among most of the fruit bat species that were assessed in this study. The overall sex ratio for E. gambianus was male biased but varied for each age class and over different years. Capture-recapture analysis gave an estimated monthly survival of 0.81 (95% CI-0.74-0.86) for E. gambianus with slight variation between sexes and age groups. Monthly survival for M. pusillus varied between 0.92 (95% CI-0.62-0.99) for adult males to 0.77 (95% CI-0.65-0.86) for immature females. This is the first study to provide estimates of these important demographic parameters for a colony of E. gambianus and M. pusillus in Africa. Females of E. gambianus attained sexual maturity at 6 months, while males matured after about 11 months. Juveniles that were born and grew through the rainy seasons were significantly bigger (forearm length: 77±4 mm vs. 74±4 mm; p<0.0001) and heavier (weight: 67±12 g vs. 59±12 g; p<0.0001) than those that were born and grew through the dry seasons. A cross-sectional sero-survey conducted for 1,047 blood samples from six species of fruit bats that were sampled during this study indicated the presence of antibodies to Hendra virus, Nipah virus and Cedar virus in several of these species of fruit bats. Seroprevalence of henipaviruses were highest in E. Helvum, with evidence of sex and age effect on seroprevalence rates. Hunting of bats, fruit collection, contact with bat urine and faeces under roosts were identified as some of the common potential human-bat interaction pathways that could facilitate spillover of zoonotic pathogens from bats. The findings of this study are important in bridging the knowledge gap about the ecology of fruit bats and provide important estimates which can be incorporated in future analysis of infection and spillover dynamics in bats and how bat ecology can influence and drive disease dynamics.
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