Department of Biology

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The Abo Blood Group and Plasmodium Falciparum Malaria in Awash, Metehara and Ziway Areas, Ethiopia.
(Addis Ababa University, 2008-07-05) Tekeste Zinaye; Petros Beyene (Professor)
The study aimed at investigating the relationship between blood group type and severe disease in P.falciparum malaria in three Ethiopian malaria endemic localities. A total of 210 cases of malaria (70 severe and 140 uncomplicated) and 190 healthy controls participated in the study. In the severe malaria category, there were 25 (35.7%), 15 (21.4%), 14 (20%) and 16 (22.9%) blood group A, B, AB and O patients respectively. Blood group O was the dominant blood type in both uncomplicated malaria (45.7%) and healthy controls (41.6 %). As compared to the uncomplicated malaria, a case of severe malaria was almost twice as likely to be of type A as to be of type O (O vs. A, odds ratio 0.42, 95% confidence interval 0.2007- 0.8789), and more than twice as likely to be of type B as to be of type O (O vs. B, odds ratio 0.38, 95% confidence interval 0.1638-0.8973), and in both cases the difference was statically significant (P=0.019 for O vs. A; P= 0.02 for O vs. B). Furthermore, individuals with severe malaria were about seven fold less likely to be of O as to be of type AB (O vs. AB, odds ratio 0.19, 95%; P=0.0005). There was significantly low mean hemoglobin concentration in the severe malaria patients than the uncomplicated malaria and healthy controls (P <.0001). Although the mean parasite density in individuals with severe malaria was higher than in those with uncomplicated malaria, the difference was not significant (P=0.35). Blood group O malaria patients had high mean hemoglobin concentration than those with blood group A, B, or AB, with significant difference only between blood group O and A (P=0.012), and blood group O and B (P=0.050). Furthermore, blood group O malaria patients were found to have a relatively low mean parasite density than patients with either blood group A or AB, but there was no significant difference in both cases (P=0.55 for O vs. A; P= 0.90 for O vs. AB) .The study revealed that on the basis of depressed hemoglobin concentration, patients with blood group O were less prone to severe P.falciparum malaria as compared to patients with blood groups A or B.
Abundance and Diversity of Top Soil Earthworms in Relation to Chemical Use in Golden Rose Agrofarm, Tefki Area, Ethiopia
(Addis Ababa University, 2007-07) Mergia, Addisu; Mengistou, Seyoum (PhD)
Despite the current environmental controversies, flower farms are becoming hot areas of investment in Ethiopia. Golden Rose Agro Farm is one of the largest, and the pioneer, flower industries in the country. To study the abundance and distribution of top soil earthworms in relation to chemical use in the farm, a total of 208 1mx1 m quadrates were marked on the ground in 10 randomly selected greenhouses. Similarly, 208 quadrates were marked in the outside chemical-free farm for comparison. Soil was then dug to a depth of 15 cm in all of the marked quadrates and hand-sorted to collect top soil earthworms. Eight plastic buckets, each filled with soil at 15 cm depth, were taken and 15 adult worms originally from chemical-free soil were introduced in to each and all were put in the greenhouses, some under chemical treatment and some free for comparison. Worms from the rose farm were also transferred to chemicalfree soil and changes were observed after 20 days. Earthworms were taxonomically identified to genus level using taxonomic keys. There was strong statistically significant variation in abundance of both adult and juvenile top soil earthworms between the two farms (P < 0.01, α=0.05). Out of the 75 adult worms introduced into the chemical-treated buckets, 98.7% (74) were dead, and in the Chemical-free buckets, out of the 45 worms originally introduced, about 95.6% (38 adult and 5 juveniles) were recaptured. About four genera of earthworms were identified in the study area, but majority of them belong to the genus Eiseniella and Dendrobaena. Seasonal variation in number and distribution of earthworms was also observed in the study. Chemical use in Golden Rose Agrofarm strongly affected abundance and distribution of top soil earthworms in the area
Abundance of Rodent on Different Land Management Intervention in Simien Mountains National Park, North Ethiopia
(Addis Ababa University, 2018-10-04) Deksios Derbe; Jebessa Habte (Professor)
This study deals with the abundance rodents in different land management intervention. Overgrazing is one of the conservation challenges of the Simien Mountains National Park . Overgrazing has been devastating the fragile afro-alpine Ecosystem. The objective of this study was to identify habitat quality and abundance of rodent by recording the new rodent hole and the common mole rat hill between May, 2017 (wet season) and January and February 2018 (dry season), assessed thirteen transect lines in average 2-4 km each. In more rodents captured were investigated in six major sites (within twelve) sub sites and the grids were established within representative vegetation covers.During dry season, five species of rodents Lophuromys flavopunctatus, Arvicanthis abyssinicus, Stenocephalemys grisiecauda, Otomys typus,Mus mahomet and one species of insectivores, Crocidiura baileyi, were recorded. There was significance variation in habitat quality among different land management intervention fresh rodent holes and common mole rat hills (p<0.002 and P<0.003), respectively. ANOVA analytical test result also indicated that rodents’ distribution were significantly different with different land management such as moderate, slightly grazed and overgrazed habitats across afro-alpine ecosystem of Simen Mountains National Park. There was also variation in species abundance in grazed, unglazed and completely grazed land management system. The highest abundance was Arvicanthus abysinicus 56% six major sites; in twelve subsets no rodent was recorded in overgrazed Wezahla one low abundance C.baileyi 0.6%. Density of rodents highest in Alchemilla plant species 8/km2and 0 in overgrazed Hypericum revolutum plant species. There was significant different in rodent abundance (P<0.04) in different land management intervention. In general, grazing pressure were negatively affected the habitat quality of rodent and common mole rats' abundances. . Therefore, to reduce overgrazing, it is recommended to strength habitat conservation to gain habitat quality. To follow participatory conservation reduce overgrazing allowing rotational cut and carry system with limited time bound exclude core area and it should be applied in local bases.
Abundance, Composition and Habitat Association of Rodents in Wonji Sugarcane Area; Ethiopia
(Addis Ababa University, 2006-06) Takele Serekebirhan; Bekele Afework (Professor); M.Balakrishnan (Professor)
A study on the ecology of rodents was carried out in Wonji Sugarcane Plantation from August 2005 to March 2006. Three trapping grids were randomly selected in the sugarcane plantation based on the growth stage of the cane as- immature sugarcane plant (ISP), young sugarcane plant (YSP), and old sugarcane plant (OSP). An additional grid was selected from bushland area outside the sugarcane plantation. A total of 629 captures were made in 2940 trap nights. Out of these, 557 individuals represented eight species of rodents: Mastomys natalensis, Arvicanthis dembeensis, Arvicanthis niloticus, Stenocephalemys albipes, Pelomys harringtoni, Mus mahomet, Mus musculus, and Rattus rattus. The remaining 72 individuals represented two insectivore species; Crocidura flavescence and Crocidura fumosa. Abundance of species varied in different growth stages of the sugarcane plantation and bushland area. There was seasonal difference in the abundance of the rodents. However, species composition was the same in all the three growth stages of the sugarcane plants and in bushland area. Variation in trap success with different growth stages of the of sugarcane plantations was significant. All age groups were represented in the population of most species. Breeding was seasonal for most of the species. The pest status of rodents in the sugarcane plantation was assessed. Analysis of the stomach contents of snap trapped rodents from the plantations showed sugarcane fibers that confirm the pest status of rodents in the sugarcane plantation while monocot plants were dominant in rodents captured from bushland area. Population estimation using minimum number alive (MNA) showed decline in each trapping session.
Acaia Byssinica Hochst. Exbenth: Pod and Seed Characteristics, Germination Physiology and Potentials for Seedling Establishment on Degraded Land
(Addis Ababa University, 1998-06) Haile, Berhank; Negash, Legesse (PhD)
This study was conducted on pod and seed characteristics, gel1ninalion physiology as well as the potentials of Acacia abyssinica Hochst. ex Benlll ssp. abyssinica fOI' growing on degraded land. Mature pods of A. abyssinica were collected ji'01/l Irees found in alld around Addis Ababa (wilhin a radius of 35 km). One hundred pods pel' tree were collected ji'on, 26 diJ)erellt frees. Comparison of the lIIeans of pod lenglh, pod widlh and seed nUlllber per pod showed Significant dij)erences (p < 0.05) among samples obtained ji'om the dij)erent localities. Pod lenglh, pod width and number of seeds per pod ranged between 3.7 and 14.4 cm, 1.0 and 2.7 CIII and 2 and 13 respeclively. 11lere was no significant correlation benveen pod lenglh and widlh. Pod lenglh and number of seeds per pod were significanlly correlated (p ~ O. OOO). On the other hand, pod widlh and number of seeds pel' pod were negalively cOI1'elaled (p ~ 0.000). Seeds collecled ji'om 35 dij)erent h'ees were made into 17 bulks (each containing 1000 seeds). 111e weight oflhe bulks ranged ji'om 74.01 to 116.11 g. There were significant dij)erences (p ~ O. OOO) among Ihe mean weights of the 17 seed bulks. E.Dects of gibberrelic acid (GA;I, indole-3-aceclic acid (lAA) and kinetin wilh concenh'alions ranging ji'01n 1IJ' M to 11J7 JIIi on percentage gennination and radicle length of chemically scarified seeds ofA. abyssinica were exall/ined None of Ihe plant growth regulators significantly increased Ihe total percenlage gel1l1ination of seeds as compared to the control. Gennination percentage decreased Significantly at higher concenh'ations of fAA (IIJ' ,vi and 10-' Ai) and kinetin (I (f' ill!). 1AA at 11J' }.i delayed genllination for aboul a week as compared to the other concenh'alions of the same, Ihough 63% of the seeds genllinated wilhin 10-15 days after incubalioll. GA, (at 11J' ill!) Significantly increased radicle length, while 1AA at 10-' 1'v1, 1IJ'M and 11J7 ivi significantly decreased the radicle length as call/pared 10 the confrol. The investigation on the potential of Ihe species for growing on degraded land involved the growing of seedlings (GA, 10-' }v1 h'eated and Ihe conh'ol) in plastic bags in Ihe greenhouse. Soil samples ji'Oln degraded land were collecled ji'om geomorphicolly different locations ji'om an area co 4 km' along Ihe road on Ihe l'vfodjo-Zeway road, at aboul 81 km soulh of Addis Ababa. Soil samples that served as a control were collected ji'01l/ places in and orollnd Addis Ababa where A. abyssinica is currently found growing. Gel1ninants ji'om 10-' JIIi GA, and the conh'ol were plan led in bolh types of soils and were left 10 grow in Ihe greenhouse fOI' 12 weeks. All the seedlings slllvived until ha/vest. Chemical and physical analyses of the soil samples were conducled in Ihe National Soils Laborato/y in Addis Ababa. The results of the analyses indicate that 10talnih'Ogen, organic carbon and available phosphorus were Significantly higher (p < O. 05) in the soils collecled ji'om places where A. abyssinica is cun'enlly grolVing than those ji'om Ihe deg/'Qded land On fhe other hand pH, No, K, Co, and CEC were found Significantly higher (p ~ 0.00) ill the soils collectedjimll degraded land The JIIeall vollies of plant height. IIIlmber ofbrallches. IIl1l1/ber of leaves. shoot dry weight alld root dry weight were fOlllld to be sigllificalltly higher ill the controls. FroJII the resllits. it cOllld be cOllelllded that: (I) the presellce of hard seed coats is the most ill/portallt factor inhibitillg gel7nillalioll ill seeds of A. abyssillica; (2) provided that seeds are carejilily scarified (chemically or mechanically), no gennination stimulators are required for obtaining maximum percentage germination; and (3) the slllvival (IIntii hmvesl) of the seedlillgs ill soils collected ji'om degraded lalld cOllld illdicate that A. abyssillica has the potelllials for growillg ill degraded land provided that the minimllm moistllre reqllirements of the species is met.
Acomparative Study on the Efficacy of Some Ethiopian Traditional Taenicides As Tested on the Earthworm
(Addis Ababa University, 1993-06) Gesare, Geraldine; Haile, Fisseha (PhD)
Intestinal parasitic infections represent serious medical and public health problems in many developing countries especially in the tropical regions. Taeniasis and cysticercosis have been recognized as important problems not only because of their impact on health but also because of economic losses resulting from condemnation of infected carcasses. The most frequently sold traditional medicines in Ethiopia are the taenicides. This is apparently due to the high prevalence of taeniasis in this country. Although a number of writers have mentioned a list of traditional taenicidal drugs in Ethiopia, very little serious work has been carried out to determine their relative efficacy. The present study is a contribution towards that end. TWelve traditional drugs used against human taeniasis in Ethiopia were screened for their taenicidal properties using the earthworm. The drugs were extracted using water and ethanol. The potency of the traditional drug extracts was compared with that of a commercial taeniacide, niclosamide. Results showed that Hagenia abyssinica (Kosso) is the most potent traditional taeniacide, followed by Glinus lotoides (Mettere), Albizia anthelmintica (Musenna), and, Myrsine africana (Ketchemo) in that order.
Actinomycetes From Unexplored Environmental Niches in Ethiopia and Their Biotechnological Potentials for Antimicrobial Compound Production
(Addis Ababa University, 2018-06-04) Kibret Moges; Abate Dawit (PhD); Zotchev Sergey B Professer); Rollinger Judith M. (Professer)
Actinomycetes have a widely recognized potential for the production of significant bioactive compounds. The major aim of this study was to isolate, screen and evaluate the biotechnological potential of selected actinomycete isolates particularily for antimicrobial compound production using standard bioassays methods, LC-MS, high resolution mass spectrometry (HR-MS) and NMR techniques. It consists of six distinct chapters. In the first chapter, general introduction, statement of the problem and major objectives are presented. The second chapter deals with the review of related literatures. The rest four chapters (3-6) are the experimental sections of the work. Hence, the third chapter concentrated on the isolation, screening, bioactivity detection and phylogenetic analysis of promising actinomycetes capable of producing bioactive secondary metabolites from various unexplored niche habitats in Ethiopia. Among the 416 isolates screened for bioactivities, 101 (24%) isolates were inhibiting the growth of C. albicans, and 88 (21%) isolates were inhibiting both C. albicans (ATCC 62376) and C. neoformans (clinical isolate). Ten isolates having considerable activities were chosen for further investigation and taxonomic identification studies. The polyphasic identification results of these isolates found to be in consistent with the genus Streptomyces described in Bregay’s manual of systematic bacteriology. Identification of the isolates have been verified by the analysis of the 16s rRNA gene sequence. The phylogenetic relationships of the isolates to type strains and best matches based on BLAST search were inferred using the Maximum Likelihood algorithm in MEGA 7 software and confirmed that all the isolates belong to genus Streptomyces. The fourth chapter deals with the cultivation of five promising isolates namely Ac-029, Ac-125, Rv-355, Ac-464 and Go-475 for bioactive secondary metabolite production and subsequently evaluation of SSF process parameters on metabolite yield. Depending on the types of the isolates, variations were observed ii in optimal fermentation process parameters on bioactive secondary metabolite production. It was demonstrated that wheat bran in the presence of supplementary nutrients, an initial moisture content of 65%, a pH value of 7.5, incubation temperature of 30 oC, an inoculum size of 3x107 CFU/mL and incubation period of 12 days were the optimal SSF conditions for most of the isolates studied. The fifth chapter focused on antimicrobial potential of Streptomyces sp. Rv-355 cultivated in submerged culture. In its bioactivity profile, Streptomyces sp. Rv-355 produced antimicrobial compounds with wider spectrum of activities against yeasts, Gram positive and Gram negative bacterial pathogens. It was found that biomass production and bioactivity profiles of Streptomyces sp. Rv- 355 are positively correlated. Bioactivity guided analysis of the crude extract from Streptomyces sp. Rv-355 using TLC, column chromatography, HPLC, LC-MS showed the presence of potential compounds. The partially purified extract showed MIC values of 50μg/mL against Candida albicans and 100μg/mL against Bacillus subtilis. The result is found to be a prelude for further analysis of the crude extract from Rv-355 using HR-MS, and NMR methods. The sixth chapter was targeted on the bioactivity guided identification and structural elucidation of members of benz[a]anthraquinone antibiotics, 8-O-methyltetrangomycin and 8-O-methyltetrangulol from Streptomyces sp. Go-475 extracts using LC-MS, HR-MS/MS and 1H NMR 13C NMR methods. Streptomyces sp. Go-475 displayed potent activity against both yeasts and Gram-positive bacteria with MIC values of the crude extracts 100μg/mL and 50μg/mL against Candida albicans ATCC62376 and Bacillus subtilis ATCC6633 respectively. The analysis revealed that Streptomyces sp. Go-475 is able to produce at least three known secondary metabolites (4-Methoxy-1(3H)-isobenzofuranone, 3-Phenylpropionic acid or 1, 2- Benzenediol and Dehydrocineromycin B) that were not detected in the SmF extract. However, betaine was detected in both SSF and SmF extracts of this isolate. Two important anti-bacterial iii compounds were purified from methanol extract of Streptomyces sp. Go-475 and their structures were elucidated by NMR and HR-MS/MS as 8-O-methyltetrangomycin and 8-Omethyltetrangulol. Besides, many potentially novel metabolites were detected, the majority of which were produced in SSF method. The findings enable us to conclude that Streptomyces sp. Go-475 and other isolates from Ethiopian soil have the capacity to produce potentially new antifungal secondary metabolites and warrant further investigations. The results also proved that SSF as promising economical and best option to produce potential bioactive secondary metabolites from Streptomyces spp. The genome sequence of Streptomyces sp. Go-475 was obtained using a hybrid assembly approach of high quality Illumina short read and low quality Oxford Nanopore long read data. The complete linear chromosome of 8,570,609 bp, featuring a G+C content of 71.96%, contains 7,571 predicted coding sequences, 83 t(m)RNA genes, and six rrn operons. Analysis of the genome for secondary metabolite biosynthesis gene clusters allowed us to connect certain clusters with experimentally confirmed molecules. The findings also verified great potential of Streptomyces sp. Go-475 for the production of chemically diverse secondary metabolites.
Activity Pattern, Feeding Ecology and Population Survey of De Brazza’s Monkey (Cercopithecus Neglectus) in Bilo Nopa Woreda, Ilu Aba Bor Zone, Oromia Regional State, South Western Ethiopia.
(Addis Ababa University, 2018-08-08) Chewaka Diriba; Jebessa Habte (PhD)
The present study was conducted on the population status and behavior of De Brazzas monkeys in the Bilo Nopa Woreda, Ilu Aba Bor Zone, Oromia Regional State, South-Western Ethiopia, from October 2017 to May 2018. The objectives of this study were to assess the population survey, determine activity pattern, examine feeding ecology and of de Brazza’s in Bilo Nopa woreda. Materials used during the study period included digital camera, geographic positioning system (GPS), and note books. Activity pattern, feeding ecology and population survey were studied for 5 minutes with 15 minutes interval scan sampling. The result was a total of 25 de Brazza's monkeys in 3 groups and 1 solitary; including 16 adults, 4 youngsters and 5 infants. The overall activity time budgets of the De Brazza’s monkeys were given in figure 8. De Brazza’s monkeys in spent 47.91% of their time in feeding, 19.97% moving and 20.65% resting, 3.51% of its time playing, 2.33% aggression, 5.13% grooming and 0.5% sexual activities. Individuals in average spent more time in feeding (48.97%) during the wet season than during the dry season (48.64%). They spent more time moving (19.84%) and resting (20.74%) during the wet season than during the dry season (16.94%) and (21.37%), respectively. They spent more time in social activities such as playing (33.61%) and aggression (2.4%) during the dry season than during the wet season, where they spent (2.74%) playing and (1.66%) aggression. More time was also spent on other activities such as grooming (6.78%) during dry than during wet season (5.67%) and sexual activity (0.37) during the wet season than during dry season sexual activity (0.36%). De Brazza’s monkeys depended most on fruits, which accounting for 76.95% of the overall diet (n= 1332 feeding records), young leaves (13.13%) made the second largest parts of their diet. Other important food items consumed were matured leaves (3.34%), seeds and gums (2.43%) and blossoms were (1.25%). Of the 21 plant species that contributed for the overall diets of de Brazza’s, based on total percentage contribution of plant food items, Ficus species were the most consumed species. All individuals in spent more time feeding on fruit during the dry season (80.32%) than during the wet season (77.37%). Deforestation by the local people for coffee plantation, agricultural expansion, trapping, over grazing and commercial purposes could impose threat to the de Brazza’s monkey populations in the future. Therefore, it is recommended that management action should be taken to conserve the most important food resources such as Ficss species and S. guineense plant trees and further investigation should be conducted to determine the sustainable and beneficial level to integrate the local people in the conservation of wildlife.
Activity Pattern and Feeding Behaviour of African Jacana (Actophilornis Africanus) in Lake Hawassa
(Addis Ababa University, 2018-06-04) Ameha, Kidest; Afework, Bezawork (PhD)
The present study documents activities and diet of African jacana (Actophilornis africanus) in Lake Hawassa. Data were collected during the wet (July- August) and dry (January- February) seasons in 2017 using scan and focal sampling methods. Repeated observations were administered to collect data on activity pattern and foraging behaviour of African jacanas. Activity patterns including feeding, scanning, flying, preening, resting and others were observed. African jacana feed primarily on insects (63.7%). They also feed on worms (16.2), larvae (5.4), snails (5%), seed (3.7%) and other (6%) during the wet season and during the dry season insects (55.6%), worms (12.2 %), larvae (8.2%), snails (7.1%) seed (6.5%) and other (10.3%) There was significance difference in the type of food consumed by African jacana during the wet season (F1 39 = 7.86, P< 0.05) and during the dry season (F1 39 = 3.11, P< 0.05). There was no significance difference in the type of food consumed between seasons (F1 39 =1.48, P> 0.05). Major activities of the species were mainly feeding 95.8 ± 5.6 and 149.3 ± 8.9 during the wet and dry seasons respectively. Feeding activity was intensive and reached its peak in the morning (6:00 - 9:00) and late afternoon hours (4:00 – 6:00). Resting was more during the mid-day (12:00 – 1:00). During the dry season, there was significant difference in the rates of feeding (F0.05, 118 = 15.24, P < 0.05) in the three time periods. The mean feeding rates were significantly higher in the morning than late afternoon (Post hoc Tukey HSD, p < 0.05). There were significant differences in the mean rates for scanning (F0.05, 118= 6.9, p < 0.05), flying (F0.05, 118= 5.03, p< 0.05), resting (F0.05, 118=4.33, p < 0.05) during the different periods. Further ecological studies on African jacana should be conducted to get more information about the bird and facilitate conservation measures in the study area.
Activity Patterns and Feeding Ecology of the Gelada Baboon (Theropithecus Gelada Arsi) and Human – Gelada Conflicts in Amigna, Eastern Arsi, Ethiopia
(Addis Ababa University, 2018-04-03) Abu Kelil; Balakrishnan M. (Professor)
Activity Patterns and Feeding Ecology of the Gelada Baboon (Theropithecus gelada arsi) and Human–Gelada Conflicts in Amigna, Eastern Arsi, Eethiopia Kelil Abu, PhD Dissertation, Addis Ababa University, 2017 Geladas are Old World monkeys found almost exclusively in the Afroalpine grasslands of the northern and central highlands of Ethiopia. However, a single cluster of gelada populations does exist south of the Great Ethiopian Rift Valley in the Arsi Region. This population was studied during June 2015–July 2017, focusing on activity patterns, diet, ranging ecology and Human–Gelada conflicts in the Amigna, eastern Arsi. Activity types and dietary data were gathered using instantaneous scan sampling method on an average of 10 consecutive days per month. Home range and day range length were determined for each unit based on point to point movements of the units between consecutive GPS locations recorded. These were calculated from the map using measuring tools in the GIS software ArcGIS’9. Human–gelada conflicts in the present study was carried out by means of questionnaire, field observation, and focus group discussions. The gelada baboon faecal dropping samples were also collected to compare the results with the questionnaire survey. Data were analyzed using descriptive statistics and responses compared using Chi-square test and one-way ANOVA. Logistic regression model was used to analyze the attitude of respondents towards gelada baboon and to determine the factors that cause crop loss by gelada baboon. The activity patterns observation showed that, feeding accounted for 40.31% of the activity budget, followed by movement (20.16%), rest (16.56%) and social (22.98%) activities. Geladas spent significantly more time in feeding (P < 0.05) and moving (P < 0.05) during the dry season compared to the time spent in the wet season. They spent significantly more time in resting (P < 0.05), playing (P < 0.05), grooming (P < 0.05) and aggression (P < 0.05) during the wet season compared to the dry season. Geladas diet mainly included grass blades (48.07% of feeding scans), iv though they also consumed grass roots (18.14%) and leaves of forbs (10.96%). Arsi geladas consumed a total of eight plant species. Among these, the top four accounted for 81.16% of their overall diet. Hyparrhenia hirta contributed for 64.76% of the overall diet of gelada baboons. Ipomoea hildrbrandii ranked second, Euclea racemosa third and Ficus vasta fourth accounting for 10.84%, 5.56% and 4.53% of the overall diet, respectively. There was significant differences in the total time spent in feeding on Ipomoea hildrbrandii (P < 0.05) and Opuntia strcta (P < 0.05) between dry and wet seasons. The average daily range lengths during the wet seasons was 792.60 m and during the dry seasons was 1022.87 m. The home range areas of gelada groups over the course of the study period was 3.26 km2 and 5.44 km2 during wet and dry seasons, respectively. Among the respondent, 79.85% reported that crop damage faced by gelada baboons were increasing from time to time. As distance from the gelada habitat increased, crop damage by gelada baboons was decreased and vice versa. There was a direct relationship between the type of crops grown and the type of crops damaged by geladas (r = 0.23, P < 0.05). Among the respondents, 25.84% had negative attitude towards gelada baboon, whereas 74.16% had positive. As crop loss by gelada baboon increased, good attitude of respondents towards gelada baboon was decreased and vice versa. In general, there was strong conflict between gelada baboon and the surrounding people in most parts of the study area. Narrow ecological niche, limited geographic distribution, and conflict with local people place Arsi gelada at the risk of extinction. To ensure long-term survival of Arsi geladas, appropriate management actions should be taken to conserve the species and to minimize human–wildlife conflict.
Adoptive Transfer of Lymphocytes and its Role in Protection against Schitosoma Mansoni Infection in Arvicanthus Species
(Addis Ababa,University, 1982-07) Mengestou, Seyoum; Belehu, Ayele (PhD)
Adoptive transfe r o f pr o t f!c tio n f rom i nf 'ctcd don or J.rvicanthus !.E. rats t o uninfec t ed r c cl pient~ was t!l ttt!mpted by va ~ y ing s omc pilram ~~b.! rs such a s the i ntl:ction pe riod o f donor r ats a nd the tine of tra ns f L; r r e l ati ve to c ha l ll.;nge . Concurre nt inve stigation o n t he e ffect of h~'~ r o l o g ous infec tion and fra ctio na tion o f c e ll s 11(l!:; ~lso carri(:d out. It wa s f ound tha t cPlls from 2 mo n th- lnfLctcd dono rs had high ability t o tra n s f c r r e sista ncl.! to rc:d,p i €..nt r ats while c el ls f r om 10 75 a nd 3 month- infL:ctcc' Jonor s s howed pa rtial a bi l ity and tho s e fr om 2 . 5 mo nth- infl:ctcd donors showed an une xpe cted inhi b i t ory e f fect on t ransfe r r e cipi e nts. Transfe rs d o ne c l o s e t o ch a ll L:ng~ nay c onfe r almo s t c omple t e i mmunity t o r e cipie nt rats , \0,:.':"_ Heterologous c e stode infe ction in t hes(! r-~ts appt:"!<'Ir t o play t!I s econdary r o l e in pro t ecting aguinst ,5 •• mansoni infe ctions, while it wa s a l so f ound t hat u nfr~Ltio n a t ed cells have mo r e ability t o tr n ~sf e r r c sis t~ n cc than fr actio na t ed ce lls . Po s s ible i~mun o l o gic a l me cha nisms involved dur i ng t hese e ve nts and the pr actica l s ignifica nce of thL: Hark arc briefly discuss ed .
Adoptive Transferor Lymphocytes And Its Role In Protecton Against Schist soma Manzoni Infection In Arvcicanthus Sp Rats
(Addis Ababa University, 1982-07) Nengestou, Seyoum; Belehu, Ayele (PhD)
adoptive transfer of protection from inducted donor acanthus !!l? rats to uninstructed recipients was attempted by va~yj.ng some parameters such as the inf8ction period of donor rats and the time of transfer relative to challenge. Concurrent investigation on the effect of.': 11ctorologous infection and fractionation of cells "idS also carried out. It ",as found that cells from 2 month .. ;.nf8ctcd donors had high ability to transfer resistance to recipient rats ) while cells f"om 1. 75 and 3 month-infected donors shO\.,ed partial abi Ii ty and those from 2.5 mont11",infected donors sho"led an unexpected inhibitory effect on transfer recipients. Transfers done close to challengu day confer almost complete immunity to recipient rCl"ts, \,:,.~, .. '" Heterologous cestode infection in these rc:ts appear to playa secondary role in protecting against Eo !~ansoni infections, ,.,hile it ",as also found that unfrilctionated cells have more ability to transfer resistance thul1 fractionated cells. Possible immunological mechanisms involvGd during these events ~nd the practical significance of the work are briefly discussed.
Aerobic Grm1--Negative Pharyngeal Bacilli of Adult Ethiopians: Carriage Rates and Antibiograms
(Addis Ababa University, 1985-10) Mengistu,Yohannes; Gedebou, Messele (Professor )
The study was conducted to identify the types of Gramnegative pharyngeal bacilli and to determine their prevalence and antibiotic susceptibilities. One~thousand pharyngeal sHab specimens were processed: 300 from students, 303 from adult employees of Berhanena-· Selam Printing Press (BSP), 200 from hospital staff and 197 from patients. The isolates were iden'tified by standard biochemical tests. All isolates were tested for their sensitivities to 11 antibietics using the Kirby-Bauer technique. Forty-five (15%) students, 53 (17.5%) employees of BSP, 27(13.5%) hospital staff and 54(27.4%) patients were carriers of one or more Gram-negative bacilli (GNB). The pharyngeal carriage rates of GNB were similar among the various groups of healthy subjects (P>O.l) but they were lower than that of the patients (peO.Ol). The increase in prevalence vIaS not correlated to antimicrobial therapy, but seems to be associated vlith underlying disease and duration of hospitalization. There was no association between isolation rates of GNB and age or sex. Two hundred and nineteen strains of more than 18 species of Enterobacteriaceae or nonfermenting Gram-negative bacilli were isolated. Colony counts of these organisms were lower among healthy subjects than among pa'tients. Klebsiella Vias most frequently ir;olated (37%), followed by _~seudo2!'-0Tl_a.? (13.2%), -E-n-te-r-o-b-a"ct-e-r (12.8%) and -A=c-i-n--e-t-o-b-a_c ... -t-e--r (10%). Others were less frequently isolated. The frequency of isolation of Klebsiell~ was higher from students (49%) than from the other three study groups (32.5%; P<0.05). The J)ol}rhospital isolates were more sensi ti ve than the hospital isolates. Over 70% of the nonhospital isolat*s were sensitive to 8 of the 11 antibiotics but 55%, 32% and 30% were sensitive to cephalothin, carbenicillin and ampicillin respectively. Over 74% of the hospital isolates were sensitive to':only polymyxin, gen-tamicin and trimethoprim<'sulphamethoxazole. About 59-64% of the hospital isolates were sensitive to chloramphenicol, kanamycin and sulphadiazine, while to the other antibiotics only below 33% were sensitive. Only 4.4% of nonhospital isolates were sensitive to all. A few strains showed intermediate susceptibilities to antibiotics. Nultiple antibiotic resistance Has higher among the hospital isolate (88.5%) than among the nonhospital isolates (59.6%; P
Aerobic Heterotrophic Bacterial Flor1ff one of Shalla Hot Springs
(Addis Ababa University, 1991-06) Kibret Mulugeta; Abegaz Berhanu (PhD)
Four sites in one of the hot springs of Shalla were selected for the study. The water from the sites merge to form a stream lqhich forms a temperature gradient. In this sttldy four' media were compared for the cuI ti vation and isolation of aerobic heterotrophic bacteria. The pH of the hot spring was 8.7 with a temperature of 96-560C. The formulated media were adjusted to pH values of 7.0-13.0. However,high counts of bacteria (lxl03-7xl01 cfu/ml) was only registered when the pH lqas adjusted between 8.0 and 9.0. A medium containing normal concentration of Trypton Soya Agar (TSA) was effective in supporting the growth of bacteria than a medium containing onequarter strength of TSA or supplement of tl'ace minerals. Replacing trace minerals ld th hot spring water improved the total number of bacteria growing and also the number of isolates. Thermophiles were numerous (lxl03-7xl01 cfu/ml) than thermotolerants (2xl02-2xlOI cfu/ml) at all si tes. The population of Bacillus brevis, Bacillus sphaericus, Bacillus stearothermophilus and Hicrococcus sp. was found to be low at lOlqer environmental temperatures than at higher environmental temperatures. In the course of this study a total of 44 microorganisms were isolated and characterized. Twenty nine were identified. to the species level and were found to be members of genus Bacillus. Three isolates were Gr~n-positive cocci identified to the genus level - Micrococcus. The remaining 12 isolates were either Gram-positive, filamentous or non-filamentous rods which need a detailed biochemical analysis for identification. To identify if any of the isolates may have industrial applications, they were checked for production of amylase and protease. Fifteen of the isolates produced protease, 18 amylase and eleven produced both amylase and protease.
Aerobic Heterotrophic Bacterial Flora of one of Shalla Hot Springs
(Addis Ababa,University, 1991-06) Kibret, Mulugeta; A. Gashe, Berhanu (PhD)
Four sites i n one ot the ho t.. springs ot Shalla were selec ted for the study. The wate r fr om t he sites me rge to form a s t ream whic h forms a te mperature gradient . In this study f our media we r e compa1;' ed tOI? the c ultivation and i solation o f aerobic heter otrophic bac ter i a. The pH of the ho t spring was 8. 7 with a temperature of 9G-56'C . The f o rmulated Illedia were adjusted to pH values o f 7 .0-13 .0. Howeve r , hlgh count s of bacte ria (lxlOl - 7x lOt c f u/ mll was only r egis tered when the pH was ad juste d be twee n 8.0 and 9.0. A medi um containing normal conce ntra tion of Trypton Soya Agar (TSA) was effective i n s uppo rt ing the growth of bacteria t han a med i um c on taining one quarte r strength of TSA o r supplement o f trace minerals. Replaci ng trac e minerals wi th hot s pri ng "" ate r improved the total numbe r of bacteria irowlng and also the number or i so l ates. Thcrmophl1ea were nume r o us (l:d Ol __ 1x l 0' clu/rol) than the rmo tol e r ants (2xlOl_2xl O( c fu/ml) at all sites . The population of Bac illus brevis , Bac illus spbae ricu8, Bacillus s t e arothermQphilu3 and Mi c r ococcus sp. was found to be low at l owe r e nvironmental temperatures than at hliher environmental temperatures . In t he course of t hi s s tudy a total of 44 micro organisms we r e isolated and char.cterlJ1ed. Twenty nine we r e identified to the s pecies level and were touftd to be membe r s o f genus Baci llus . Three isolates were Cram-positive cocci id e ntified t o the ge nus l eve l - Micrococcus. The r e main i ng 12 isolates were ei ther Gram-positi ve , filame ntous or no n- filamentous r od s wh ich need a deta il ed bioc he mi c al analysis for i denlifi c ation . To identify if any o f the isolates may have industrial applications , they we r e c hecked f o r product i on o f amylase and protease . Fifteen o f the isolates produced protease, 18 amylase and eleven I-roduced both amylase and protease.
The Aetiological Causes of Tuberculous Lymphadenitis in Butajira, Ethiopia
(Addis Ababa University, 2001-06) Habte, Abebe; Olobo, Josph (PhD); Harboe, Morten (Professor); Lakew, Mekuria (PhD)
The utility of MPB70 antigen in serodiagnosis of Mtuberculosis complex infection and the polymerase chain reaction (PCR) for rapid identification of the causative agent if cervical lymphadenitis were investigated. The PCR assay was based on detecting a 506-bp DNA segment belonging to the alpha 32 kDa antigen (85B) common in the genus Mycobacterium, a 984-bp DNA segment belonging to the insertion sequence IS 6110 specific for the M tuberculosis complex, and a 185-bp pncA gene segment at position 169 allele-specific for genetic differentiation of Mtuberculosis from M bovis. For the ELISA purpose, sera from 25 tuberculous lymphadenitis (TBLN), 14 non-tuberculous lymphadenitis (NTBLN), 11 pulmonary tuberculosis (PTB) patients and 10 healthy control (HC) subjects were tested. For PCR, in 39 clinically diagnosed tuberculous lymphadenitis patients, fine needle aspirates (FNA) were processed and tested. Of these, which 14 were considered as non-tuberculous lymphadenitis by fine needle aspirate cytology (FNAC). Of the 39 clinically diagnosed TBLN, 27 (69%) were positive by ELISA. When this was compared with the assumed gold standard (FNAC), it showed 64% sensitivity, 21% specificity, 49% efficiency, 59% positive predictive value and 25% negative predictive value. With PCR, 29 (74%) of 39 were positive, showing 72% sensitivity, 21 % specificity, 54% efficiency, 62% positive predictive value and 30% negative predictive value. When it was compared with FNAC.Of the 29 PCR positive for genus Mycobacterium and Mtuberculosis complex, 18(62%) of them were identified as M tuberculosis, 3 (10%) of them were M. bovis and 8 8%)of them were found co-amplifying M.tuberculosis and M. bovis. These data indicated that both serodiagnosis with MPB70 antigen of the M.tuberculosis complex and peR assay are useful for rapid identification of tuberculous lymphadenitis and better management of patients.
Aflatoxins (B1, B2, G1 And G2) and Aflatoxigenic Fungi In Export Standard White and Red Sesame Seeds (Sesamum Indicum L.) Grown In Humera and Wollega, Ethiopia
(Addis Ababa University, 2017-06-03) Makiso, Markos; Zewdu, Ashagrie (PhD)
The oilseed sector is one of the fastest growing sectors in Ethiopia, both in terms of its foreign exchange earnings and as source of income for millions of Ethiopians. Oilseed crops are recognized to be potentially suitable substrates for the production of aflatoxins by aflatoxigenic fungi. This study aimed to evaluate Knowledge attitude and practice (KAP) of sesame exporters about aflatoxin contamination, analyze thousand seed weight, moisture, crude fat and peroxide value of white and red sesame collected from Humera and Wollega varieties. Determining the level of aflatoxins of white and red Ethiopian sesame seeds. Compare the level of aflatoxins between white and red Humera and Wollega varieties. Isolate and identify aflatoxigenic fungi from sesame seeds. A total of 27 sesame samples were collected from Ethiopian Agricultural commodities warehouse service enterprise, located in Addis Ababa. Semi-structured questionnaires used for knowledge, attitude and practice survey of sesame exporters and Thousand seed weight, moisture, crude fat and peroxide value of sesame seeds have been done according to American oil chemists society (AOCS) method. Analysis of aflatoxins was done by using HPLC with solid phase extraction clean up method. Isolation and identification of aflatoxigenic fungi has been done by culturing sesame samples on Potato dextrose agar (PDA) media. Sixty percent of exporters doesn't have any idea about aflatoxins and all of them cannot make aflatoxins test for sesame seed before export. Thousand seed weight, moisture, crude fat and peroxide value were ranged 2.89-3.22g/1000 seed, 3.33-4.99 %, 46.75-57.75% and 2-8.2 meq/kg, respectively. Aflatoxins detected from 93 % of samples in the range of (0.44 - 48.28 ng/g). Average content of AFB1, AFB2, AFG1, AFG2 and total aflatoxins are 0.83 ng/g, 6.82 ng/g, 17.25 ng/g, 1.17 ng/g and 26.07 ng/g, respectively. AFB1 and AFG2 detected below European union (EU) maximum limit for individual aflatoxin (2 ng/g). AFB2, AFG1 and total aflatoxins content is above the permissible limit set by EU for both individual and total aflatoxins (15 ng/g). Red sesame variety indicates relatively higher level of aflatoxins contamination as compared with white Humera and white Wollega sesame. Aspergillus flavus, A. parasiticus and A. niger isolates identified. Based on the finding, the contamination level may affect national economy.
Age Sex Malaria Prevalence Plasmodium Falciparum, Plasmodium Vivax
(Addis Ababa University, 2015-06) Mulugeta, Solomon; Getu, Emana(Professor)
is one of the deadly disease caused by four main species of protozoan: P.Vivax P.falciparum, P.ovale and P.malariae. The 5th species P. knowlesi also infect human being occasionally. Malaria is transmitted by female anopheles mosquito. The aim of this study was to assess and analyze the trends of malaria prevalence from 2006 to 2015 G.C. at Atat primary hospital and associated risk factor to malaria infection. For this study data were taken from the hospital registration log book for a period of ten years from 2006 to 2015 G.C. Moreover, data for risk factors were collected from randomly selected households to which structured questionnaires were provided. Among the recorded malaria cases there is no clear trends idea as to which sex is more affected by malaria. In 2006, 2007 and 2011 roughly, 4%, 3%, 5%, , males were, respectively infected by malaria. Conversely in 2008, 2009, 2012, 2013, 2014, 2015 about 3%, 4%,2%, 4%, 1% and 4% females were, respectively infected with malaria. As to which species of Plasmodium dominantly infect heman being in the study hospital in 2006, 2007, 2008, 2009, 2010, 2011, and 2013 over 50% of malaria was caused by P. vivax, while in 2012, 2014, 2015 the highest proportion was caused by P. falciparum. Among malaria cases in different age groups, there is no clear trend as it varies from year to year. The highest record of malaria was in October to December followed April- June and the least was from January to March for all years. The prevalence of malaria with regard to sex, and age are statistically insignificant (P>0.05), The prevalence of malaria with seasonal variation is statistically significant P<0.05. Improper utilization of long lasting insecticidal bed nets, insufficient indoor residual spraying, the presence of mosquito breeding area were identified as the associated risk factors. All the above risk factors were found to be significantly associated with the risk of getting malaria parasite (P<0.05). It can be recommended that proper use of net should be practiced by all members of the households and indoor residual spraying should be done regularly. key words: Age, Sex, Malaria Prevalence, Plasmodium falciparum, Plasmodium vivax
Age and growth determination of tilapia, Oreochromis niloticus L. (Pisces: Cichlidae) in some lakes in Ethiopia
(Addis Ababa University, 1998-12) Admassu Demeke; Mengistou Seyoum (PhD)
Tilapia, Oreochromis niloticus L. is the most important fish in Ethiopia. Knowledge on age and growth of the fish is essential for fisheries management, and for further detailed studies. In this study, age and growth of O. niloticus in Lakes Zwa\, Langeno and Chamo was studied from microzones and macrozones in otoliths. The usefulness of otoliths to determine age was established by examining the existence of regularly formed translucent and opaque macrozones. The effect of subtle changes in temperature on body growth and on otolith macrozone formation was also experimentally tested. The growth of the fish in various lakes was also compared. Two translucent macrozones, each associated with biannulus (a type of annulus formed twice a year), were fOlmed each year in otoliths of O. niloticus in Lake Zwai. Biannulus formation was connected to fluctuations in temperature, quality and quantity of food, and to intensive spawning activity. Translucent macrozone was fOlmed in otoliths, and somatic tissue growth was slow, in tilapia that were transferred from 240C to slightly lower temperature treatments. Fish that were transferred from 240 C to higher temperatures grew rapidly, and more opaque material was deposited in their otoliths. At the high test temperatures, translucent macrozone was formed in otoliths of fish that had dpening or dpe gonads. O. niloticus in Lake Zwai has two spawning peaks, hence two major annual recruitment cohorts. Fish from the two cohorts were discriminated and age was determined from the number of biannulus in otoliths by relating median hatch-dates with the dates of capture. Ages determined in this manner (macrozonal ages) were highly correlated (r2 = 0.85) with microzonal ages. Growth of juvenile O. niloticus in Lakes Chamo, Zwai and Langeno was described by Gompertz model fitted to length and microzonal age data. Growth was most rapid in Lake Chamo, intennediate in Lake Zwai and slowest in Lake Langeno. Rapid growth of juvenile O. niloticus in Lake Chamo was attributed mainly to warm temperature and better food quality in this lake. The growth of adult O. niloticus in Lakes Zwai, Awassa and Haiq was described by von Bertalanffy model fitted to mean length and macrozonal age data. Growth rate was most rapid in Lake Haiq, intermediate in Awassa and least in Zwai. Rapid growth in Haiq was attdbuted to better quality food in this lake.
Age and Growth of Oreochromis Niloticus (Pisces:Cichlidae) in Lake Hayq, Ethiopia
(Addis Ababa University, 1995-06) Alemu, Kebede; Tefera, Getachew (PhD); Admassu, Demeke (PhD)
otoliths from 447 mature and 308 immature Oreochromis niloticus (10 to 304 mm total length) from Lake Hayq were measured and examined for translucent and opaque macrozones. Microzone analysis was also conducted on the 308 immature O. niloticus otoliths. Macrozonal daily age estimate was determined by extrapolating the number of days between the date of capture and calender birth dates. utilization of the number of macrozones, condition on the edge of otoliths and date of capture enabled the separation of fish into recruitment groups. Microzones on the otoliths were enumerated and used as a measure of age in days and to hind cast hatch dates. The relationship between otolith size and fish total length 11as also examined. It appears that the breeding of o.niloticus in Lake Hayq is continuous with high peaks during !·larch-May and July-October. Two translucent macrozones '''ere formed per year during January-February and June-July. Fish spa~ned between January and May and July and November of the same year form the first translucent zone associated with biannuli at different times. The close agreement between macrozonal and microzonal daily age estimates (r=O. 84) sUbstantiates the usefulness macrozone analysis to assess the age of O.niloticus. There was a strong linear relationship between otolith size and fish size and also between microzone count and fish length. HOI-leVer, a linear relationship underestimates fish size at later ages. Values of size-at-age estimates obtained from macro zone and microzone analysis and fish total length-otolith radius relationship were close to each other. This demonstrates the usefulness of results from the latter method in supporting conclusions drawn from macrozone and microzone analysis.

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