Veterinary Microbiology

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STUDY ON BACTERIAL PATHOGENS OF FISH IN SOUTHERN GULF OF LAKE TANA WITH SPECIAL REFERENCE TO AEROMONAS HYDROPHILA AND EDWARDSIELLA TARDA
(2007-06) ANWAR, NURU; Dr. Bayleyegn Molla, Dr. Eshetu Yimer
A bacteriological study was conducted from September 2006 to March 2007 to estimate the occurrence and distribution of important Gram-negative bacteria with special reference to Aeromonas hydrophila and Edwardsiella tarda from the kidney and intestine of apparently healthy fish and their aquatic environment in the southern gulf of Lake Tana and carcasses of filleted fish (from commercial enterprises and local dealers) in Bahir Dar, Ethiopia. From a total of 510 swab samples taken from the kidney and intestine of 255 apparently healthy fish, different bacterial species, which belong to the family Aeromonadaceae, Vibrionaceae and Enterobacteriaceae were isolated and identified. Among the isolates Aeromonas (A.) hydrophila (7.1%), Aeromonas (A.) caviae (9.8%), Aeromonas (A.) sobria (15%), Edwardsiella (E.) tarda (2%), Vibrio spp (7.8%), Yersinia (Y.) ruckeri (3.1%), Edwardsiella (E.) ictaluri (1.2%) and atypical strains of Aeromonas (A.) salmonicida (13%) were isolated in both the kidney and intestinal samples. Proteus (P.) mirabilis (5.9%), Enterobacter (E.) aerogenes (5.1%), Plesiomonas (P.) shigelloides (4.3%), Yersinia (Y.) enterocolitica (3.1%), Escherichia (E.) coli (2.4%), Klebsiella (K.) pneumoniae (2.4%), Proteus (P.) vulgaris (1.6%), Shigella (S.) sonnei (0.8%), Citrobacter (C.) diverses (0.4%) and Citrobacter (C.) freundii (0.4%) were isolated only from the intestine of fish. From carcasses of filleted fish A. sobria constituted 13.2% of the total isolates followed by A. caviae (9.6%), atypical strains of A. salmonicida (6.4%), Y. enterocolitica (4.8%), A. hydrophila (3.6%), E. coli (2.4%), P. mirabilis (1.6%), C. diverses (1.2%), P. shigelloides (1.2%) and Vibrio spp (0.8%). Out of 62 water samples, 47 (75.8%) were positive for Aeromonadeceae and Enterobacteriaceae. All the bacterial species, which were isolated from the water samples, were also recovered from fish. Indicators of water pollution bacteria such as A. caviae and E. coli were more frequently isolated from sampling stations found in inshore littoral zone than stations found in sub-littoral and pelagic zones that are situated relatively far from the point source pollutions and hence less likely to be exposed to pollution. XIII From the results of the present study it was concluded that the intestine of fish have been found to be harboring a large group of bacterial species that may be a resident and/or transient microorganism. Isolation of similar types of bacteria from the fish, filleted fish and their aquatic environment has been recorded during the study period. The detection of similar bacterial species both in the fish and the water samples has some implications on the relationship between the fish and their aquatic environment (even though it requires some molecular characterizations of both isolates). Some of the bacterial isolates including Aeromonas hydrophila and Edwardsiella tarda are opportunistic pathogens of fish and may cause mortalities when the fish come under stress. Furthermore, the recovery of various organisms, which are potentially pathogenic to humans, in the kidney and alimentary tract of fish, and/or carcasses of filleted fish suggested that fish either improperly handled, undercooked or consumed raw might cause various diseases to susceptible individuals.
COMPARISON OF CLINICAL TRIALS OF BOVINE MASTITIS WITH THE USE OF ANTIBIOTICS AND HONEY
(2007-06) TAMRAT, TOMAS; Prof. A.R.S. Moorthy
A total of 423 representative randomly selected Holstein, Jersey and local zebu lactating cows located in Wolaita zone at Soddo Zuria Woreda of Southern Nation Nationalities and Peoples Regional State were examined. All the 46 lactating cows of Soddo dairy farm, 11 lactating cows from Soddo Veterinary Clinic, 103 lactating cows from urban dairy holders and the rest 263 were X randomly selected lactating dairy cows from 18 rural Kebeles were included and tested to determine the prevalence of mastitis by using mastitis detecting BOVI-VET (RUUSE, DENMARK), indicator paper and white side test. Milk samples were cultured from 329 cows infected with different grades of mastitis. Examination for mastitis infection in Soddo Zuria Woreda revealed that there were 99 (23.4 %) clinical and 230 (54.3 %) sub clinical cases. Out of 423 cows 99 clinical cases and 230 sub-clinical cases were recorded and grouped into grade I, II, III, IV level of infection and only clinical cases were subjected to antibiotics and honey intramammary infusion treatment. The prime objective of the study is to examine the safety and efficacy of honey compared to a known antibiotic infusion in lactating mastitic cows. Minimum Inhibitory Concentration (MIC) of honey was determined by using different dilutions and different species of bacteria available at the microbiology laboratory of FVM. And it was revealed that minimum concentration of honey that inhibited E. coli was 10 %; L. monocytogenes and K. pneumoniae inhibited at 20 %; Staphylococcus and Streptococcus spp, were inhibited at 30% concentration, where as Micrococcus spp. at 40 % concentration. Salmonella enteritidis was resistant (shown growth in all concentrations). Out of ninety-nine clinical cases, forty-eight cases were treated with antibiotic (Multiject IMM.) infusion and fifty cases were treated with Beza honey. Milk samples from the cows identified and recorded for treatment trial groups were re-cultured within one month post-treatment. Cases included in the analysis had at least one mastitis pathogen isolated from the initial milk samples. Overall bacteriological cure rate of treated cases was 54 % (53 of 98). The effectiveness of honey in clearing bacterial infection in the intramammary infusion for mastitis treatment revealed similar to antibiotic (54.2% (Multiject IMM.) treated cases. Antibiotic and non-antibiotic treatment responses were associated with grade of affection. Honey treatment was more effective 78.1% in grade III type of mastitis when compared to treatment of grade II type of mastitis (11.1%); where as multiject was more effective in grade II type of mastitis (41.9%) and slightly less curative rate (76.4%) for grade III type of mastitis when compared to honey. The present study indicated that honey treatment could be an alternative treatment to antibiotics so that indiscriminate use of antibiotics and emergence of antibiotic resistance strains of microorganisms could be avoided and at the same time financial benefits can be obtained. Treatment with honey is more economical i.e.7-8 times cheaper than the available mastitis treatment drugs in the country. As an alternative to antibiotic treatment for XI mastitis, 10 ml of 40% honey intramammary infusion for each quarter for 3 consecutive days can be tried.
STUDY ON SHEEP BRUCELLOSIS IN SELECTED WOREDAS OFTHE EASTERN AMHARA REGIONAL STATE, NORTH EASTERN ETHIOPIA
(2008-06) SHIMELES, ABEGAZ; Prof. Muniyappa. L., Dr. Kelay Belihu
A cross-sectional study was conducted in South Wollo, North Wollo and North Showa Zones of the Amhara Regional state, between octobrr, 10, 2007 to march 1, 2008,with the objectives of determining the seroprevalence distribution and magnitude of brucellosis in sheep and identifying the potential risk factors associated with diseases. Two strata sampling methods were employing, sheep flock in extensive production (n=1838) and sheep flock in intensive production system (n=571) , with an overall serum sample of 2409, collected from sheep above 06 months of age without previous history of vaccination. The overall seroprevalence obtained by Rose Bengal Test was 4.98% (n=120), the 120 positive sera by RBPT was subjected to the Complement fixation (CFT) and 118 (4.89%) sera become positive for antibodies to brucella infection.. The subsequent analysis were based on the 4.89% (n=118) sera that were positive to both the RBPT and CFT (serial interpretation) test results. In the current study, a flock and individual level seroprevalence for brucella antibodies were conducted. A flock was said to be positive if at least one animal reacted positively by the test. The overall individual and flock level seroprevalence for brucella antibodies in sheep were 4.89% (n=118) and 22.26% (n=274) respectively. Analysis of the findings among the two production system indicated significant difference in both individual (p<0.05) and flock level (p< 0.05) seroprevalence. Brucella seroreactor female and male sheep vary significantly in the extensive production system (p<0.05) compared with intensive production system (p>0.05%). Analysis of the findings among different age groups indicated the existence of a significant difference (p<0.05) in extensive production, whereas in intensive production statistically no significant difference (p>0.05). The existence of seroprevalence in the three flock categories shows significant difference (p<0.05) in extensive production, while no difference (p>0.05) in intensive production system. Concerning breed level seroprevalence for brucella antibody in both production system reveal significant association (p>0.05). Moreover, this study was also assessed the association of reproduction and production performance in relation to brucella infection. Generally the present study disclosed the importance of brucella seroreactor sheep in the study areas, hence, care should be taken and warranting more focused investigation, so as to support intervention efforts in the region.
EPIDEMIOLOGICAL AND MICROBIOLOGICAL STUDIES ON CALF DIARRHOEA AND PNEUMONIA IN DEBRE ZEIT, HOLETA AND MUKE TURI DAIRY FARMS, ETHIOPIA
(2008-06) YENEHIWOT, BERHANU; Dr. Moses N. Kyule, Dr. Kelay Belihu
A six-month prospective study was conducted in Holeta, Debre Zeit and Muke Turi dairy farms between November, 2007 and April, 2008 with the major objective of determining both the cumulative incidences of neonatal calf diarrhoea (NCD) and pneumonia. In addition, determination of calf mortality rates, identification of agents of NCD, pneumonia and potential risk factors as well as determinations of the antibiotic sensitivity patterns of the bacterial pathogens. Cluster sampling was used. A total of 429 calves, from seven intensive dairy farms were followed up. The farms were described using a pre-tested questionnaire and personal observations. Study calves in each farm were visited weekly and appropriate test samples collected from diarrhoeic and pneumonic cases. Antigenic ELISA test was utilized to identify four major enteropathogens (rotavirus, coronavirus, Cryptosporidium parvum and E. coli K 99). Standard isolation techniques were used to identify Salmonella and other strains of E. coli from diarrhoiec cases (n=112) and Pasteurella species, Mannheimia species and Haemophilus somnus from pneumonic cases (n=28). In addition, the antimicrobial susceptibility pattern of the bacterial isolates was performed. The cumulative incidences (CI) of NCD in Holeta, Muke Turi and Debre Zeit dairy farms were 0.41, 0.63 and 0.37, respectively. While for pneumonia, they were 0.12, 0.09 and 0.07, respectively. Higher CI of NCD was recorded from Farm 1 with 0.65 followed by Farm 3 with 0.63. The least CI was observed in Farm 2 of 0.11. Highest calf pneumonia was observed in Farm 6 followed by Farm 1. No calf pneumonia was observed in Farm 5. Associations of the potential risk factors for NCD and pneumonia revealed significant results with young ages. Significant positive hazard rates of both diseases were recorded in young age-groups. Other risk factors (sex of calves, breed, etc) were not significantly associated with these diseases. The ELISA results showed that, C. parvum was prevalent in the majority of calves with diarrhoea followed by rotavirus, coronavirus and E. coli K 99. The bacterial isolates were 91.96 % of E. X coli other than the strain K 99 and 24.11 % of Salmonella species. Nasal swab samples taken for isolation of Pasteurella and Mannheimia species revealed 42.85 % positive reactors for Pasteurella and Mannheimia species. No Haemophilus somnus was isolated. Antimicrobial sensitivity test was performed for all the bacterial isolates. Norfloxacillin and gentamycin were highly sensitive and clindamycin the least sensitive. The susceptibility to other antimicrobial agents varied by different bacterial isolates, but resistance to all antimicrobials used were observed in most of the isolates. In conclusion, NCD is a serious problem among dairy calves followed by pneumonia. Both of them were influenced by the age of calves. These diseases have complex etiopathogenesis. Therefore, further epidemiological and microbiological studies of NCD and pneumonia with aims of designing and implementing appropriate prevention and control strategies are strongly recommended. In addition, the higher rate of antimicrobial resistance necessitates the strategic use of the drugs.
A STUDY ON BOVINE AND HUMAN BRUCELLOSIS IN URBAN AREAS AND IN CATTLE BREEDING CENTERS, NORTH WESTERN AMHARA REGION, ETHIOPIA
(2008-06) TADDESSE, YAYEH; Dr. Girma Zewde, Dr. Ermias W/mariam
A cross-sectional study was conducted from October 2007 to March 2008 in urban areas (Bahir Dar and Chagni towns) and in cattle breeding centers (Andassa Livestock Research Center and Metekel Cattle Breeding and Improvement Center) to determine the seroprevalence and to identify potential risk factors associated with bovine brucellosis, to find out its association with reproductive disorders and to assess the public health hazard. Sampling units were selected by one-stage cluster sampling method. Samples were tested serologically for brucellosis and questionnaire data was collected. In cattle breeding centers, all eligible cattle were sampled. Sera of 2,224 cattle from 183 herds were subjected to Rose Bengal Plate Test and those positives were further tested by Complement Fixation Test. An overall individual and herd level seroprevalences of 0.49% (11 of 2,224) and 4.9% (9 of 183), respectively were found. Statistically significant difference in seroprevalence was found between urban areas 1.1% (5 of 443) and cattle breeding centers 0.3% (6 of 1,781) (P< 0.05). The potential risk factors such as sex, age, breed, parity, herd size, pregnancy status and source of replacement stock were not significantly associated with brucellosis seroprevalence. Among the reproductive disorders, abortion was significantly associated with seroprevalence of brucellosis (P<0.05). Furthermore, management and husbandry risk factors were not significantly associated with brucellosis seropositivity. Out of 79 individuals tested for human brucellosis, 6.3% (5) were positive seroreactors. However, there were no statistical associations between brucellosis and potential risk factors (occupation, sex, age, consumption of raw milk and raw meat as well as contact with fetal membrane). In conclusion, the seroprevalence of bovine brucellosis in urban areas and in cattle breeding centers was very low. Thus, slaughter of positive reactors and enhancing the management and husbandry practices were recommended.
Study on mycobacterium bovis using conventional and molecular methods in cattle slaughtered in Kombolcha Elfora Meat processing plant
(2008-06) Fekadu, Desta; Dr. Yilkal Asfaw, Dr. Gobena Ameni,
A cross-sectional study was conducted on 1138 heads of cattle at Kombolcha ELFORA meat processing plant, South-Wello Administrative Zone, Amarha Regional State from November 2007 to May 2008. The objectives of the study were to estimate the prevalence of bovine tuberculosis in cattle slaughtered at Kombolcha ELFORA meat processing plant, and to isolate and characterize the strains of mycobacteria from tuberculousis suspicious lesions. Detailed post mortem examination, bacteriological culturing, regions of difference-bases polymerase chain reaction and spoligotyping were used. The prevalence of bovine tuberculosis was 5.0 % (57/1138) in cattle slaughtered at Kombolcha ELFORA meat processing plant on the basis of detailed post-mortem examination. There was no significance difference in prevalence between male and female (P > 0.05), as well as among the age groups (P > 0.05). Mycobacteria were able to be isolated from 28 of the 57 cattle with gross lesion. A total of 49 isolates were recovered from the different tissues of these 28 cattle, and 20 isolates showed signal for M. tuberculosis complex species of which 19 were M. bovis while one isolate was M. tuberculosis. Further characterization of the strains of M. bovis using spoligotyping revealed the presence of five different cluster of spoligotyping pattern, which include Ethiopian M. bovis train 1, SB1176, SB0134, SB0133 and new strain. The binary number representation of the new strain is 1100000101010110111111111111111101111100000 where 1 indicates the presence of a spacer and 0 indicates a loss. The new spoligotyping was not reported previously from elsewhere to the M. bovis database (www.mbovis.org). The findings of this study indicated that tuberculous lesions were common in cattle slaughtered at Kombolcha ELFORA meat processing plant, and hence detailed post mortem meat inspection procedures are required to minimize the risk of its transmission to the public through meat consumption. In addition, appropriate cooking of meat is required before consumption.
MICROBIOLOGICAL STUDY OF BACTERIAL CAUSE BOVINE MASTITIS AND ITS ANTIBIOTICS SUSCEBTIBILITY PATTERNS IN EAST SHOA ZONE OROMIA REGIONAL STATE
(2009-06) REDEAT, BELAYNEH; Prof. Mniyyaapa, Dr. Kelay Belihu
Mastitis is inflammation of mammary gland and primarily results from invasion of pathogenic microorganisms through teat canal. Mastitis has great effect on milk quality, production, composition and economy, and public health significance. Mastitic milk losses its appearance, flavor, maintenance of original nutritional qualities and has no long shelf life. Factors that influence infection rate with mastitic organisms are host factor, environmental factor and pathogenic factor. Mastitis can be classified as contagious and environmental depending on the source of infection. A variety of diagnostic tests can be employed to screen and detect mastitis, as well as to isolate and identify the causative agents. The study was conducted in east shoa zone Adama and Akaki woredas with the objectives of determining the prevalence of clinical and subclinical mastitis to identify risk factor of bovine mastitis, to isolate and identify the bacterial causes of bovine mastitis and to conduct in-vitro antimicrobial susceptibility test of isolated pathogens from September 2008 to 2009. For this study, 102 and 46 small holder dairy farms and 303 and 200 dairy cows were selected .by one stage cluster sampling in Adama and Akaki woredas respectively. Questionnaire survey was administered to the small holder dairy farm owners to collect data on clinical examination of animal and farm attribute. Farms inspection and clinical examination of cow was performed to associated mastitis with farm based factors and animal factors. California mastitis test (CMT) was used as screening for selection of culture samples for the cow under study. Strict aseptic producers were used when collected milk samples in order to prevent contamination with microorganism. The bacteriological culture was performed following the standard microbiological technique to diagnose the occurrence of clinical and sub clinical mastitis. All collected data analyzed by using descriptive statistics SPSS and Stata. In both the study farms the prevalence of clinical and sub-clinical mastitis were made at herd, caw and quarter level. Based on clinical manifestation for clinical mastitis prevalence and on California mastitis test for sub-clinical mastitis prevalence infections. In the result revealed that the prevalence of clinical mastitis at herd, cow and quarter level (15.6%, 5, 9% and 2.9%) and (17.3%, 3.0% and 1.5%) in Adama and Akaki respectively. X The prevalence of subclinical mastitis at herd, cow and quarter level (57.8%, 33.6%and 20.8%) and (60.8%, 25.0 % and12.7%) in Adama and Akaki respectively. The major isolates of pathogen in both areas from subclinical mastitis cases were S.aureus (26.8% and 34.8%), S.intermidiua (2.48% and 0.49%) ,CNS (18.7% and 20.9%) , St. agalactiae (5.77%and5.8%), St dysgalactaie (1.99% and1.16%), St uberis (4.47% and 1.16%) ,Bacillus Species (7.96% and9.3%), E.coli (6.46% and 6.98% ).and from clinical mastitis S.aureus (2.48% and 2.38% ), St agalactiae (_3.84% and 3.48%) in Adama and Akaki woredas respectivly . Regarding to association risk factor with prevalence of mastitis, the univariate logistic regression in cow level showed that among the risk factor considered, stage of lactation (p< 0.05), parity number (p< 0.05) and presence of teat lesion (p<0.05) significant effect of sub clinical mastitis in both woredas, milking mastitis cow last (p<0.05) in both woredas in herd level was significant effect .In considering multivariate logistic regression only stage of lactation had significant on sub clinical mastitis in both woredas in cow level. Regarding the antimicrobial tests comparing the over all efficiency (on all isolates) Gentamycine, Kanamycine, Chloramphenicol and Vancomycine were the most effective antibiotics were found susceptible in both woredas. Fallowing that Streptomycin and penicilline were effecective. The least effective drug was Bacitracine. Amoxaciline was also with relatively weak efficacy.
STUDY ON THE PREVALENCE OF BACILLUS CEREUS AND ASSOCIATED RISK FACTORS IN BOVINE RAW MILK IN DEBRE ZEIT, ETHIOPIA
(2012-06) ALEMNEH, KASSA; Dr. Girma Zewde, Dr. Tesfaye Sisay
The objectives of this study were to determine the prevalence of B. cereus, evaluate the load of B. cereus and assess risk factors associated with B. cereus load and its public health implication in raw milk samples collected from dairy farms in Debre Zeit, Ethiopia. A total of 384 raw milk samples were collected from eleven randomly selected dairy farms. The overall prevalence of B. cereus in raw milk sample was 15.4% (59). The B. cereus count ranges from 2.3 x 104 - 5.4 x 105 CFU/ml. From positive samples, 58 (15.1%) of total samples have significant counts (> 105 CFU/ml) which was above legal limit in raw milk intended for human consumption. The mean of B. cereus counts differed significantly between farms and within parities (p < 0.05). An attempt was made to assess hygienic keeping quality of milk at farm level by using semi structured questionnaire survey. Our study results indicated that raw milk samples collected from both zero-grazing and semi-intensive farm management systems were highly contaminated with B. cereus, exceeding the legal limit set for raw milk (> 105 CFU/ml), suggesting effective hygienic measures should be introduced in milk value chains during milk production, distribution and processing and food service establishments to avoid public health hazards.
SERO-PREVALENCE AND PARTICIPATORY STUDY OF CONTAGIOUS CAPRINE PLUEROPNEUMONIA IN GULINA WEREDA, AFAR NATIONAL REGIONAL STATE, ETHIOPIA
(2012-06) AMARE, GETU; Dr. Tesfaye Sisay
A cross sectional study of Contagious Caprine Pleuro pneumonia (CCPP) in goats was conducted from October 2007 to April 2008 to determine sero prevalence in Gulina district of Afar National Regional State. A total of 446 sera were collected from goats. Complement Fixation Test (CFT) was carried out at National Veterinary Institute. The Participatory approaches are holistic in nature where by all aspects of the phenomenon questions are studied by the use of multiple methods in a process referred to as triangulation. Camels had the highest proportion (44.6%) followed by 30.6% of goats to the relative importance of livestock species to pastoralists. The possible source of CCPP is watering followed by grazing (31.9%) due to goats gathered from different sites for the search of feed and water. The main control tactic for CCPP is Isolation of the affected goat(s). Among the cases in the area 34.7% were pasteurellosis followed by CCPP. Significant numbers of goat were lost due to CCPP (32.6%) next to PPR (38.7%). Drought (65%) is a major challenge to their livestock. The overall sero prevalence was 42.8% (n = 191). The age group sero prevalences were 42.4, 36.8 and 49% in age group less than 1, 1-3 years and >3 years older respectively. Sex specific sero prevalence observed was 40.9% in males and 43.7% in females. Because of few male goats compared to females in each flock, the contribution of males to the total sero positivity was only 32.9%. High significance association was found between Flock size 51-150 and greater than 150 (OR=25.6, P=0.000) to CFT test. Goats of less than 1 year were found to be safer (OR=0.974, P=0.324).
LUMPY SKIN DISEASE (LSD): OUTBREAK INVESTIGATION, ISOLATION AND MOLECULAR DETECTION OF LSDV IN SELECTED AREAS OF EASTERN SHEWA, ETHIOPIA
(2012-06) RGBE, HAFTU; Dr. Tesfaye Sisay, Dr. Gelagay Ayelet
The study was undertaken to investigate outbreaks of lumpy skin disease (LSD), isolate and identify LSDV at molecular level, to asses the economic significance of lumpy skin disease in the study area, and to asses the protection of the vaccine for lumpy skin disease given at field condition. The study was conducted from September 2011-April 2012 in selected areas of eastern Shewa. LSD Outbreaks were reported from 4 different areas of Eastern Shewa; Adama (5 intensive fattening farms), Wenji (4 intensive fattening farms), Mojo (small holders) and Welenchit (small holders). In total 2174 local Zebu breed cattle, the majority composed of males (98.8%), were visited and clinically diagnosed. From the total of visited cattle 296 (13.78%), 108 (5.03%) and 1 (3.84%) morbidity, mortality and abortion rates were recorded respectively. Analysis of the outbreak statistics revealed a relatively consistent morbidity rate with highest value in Adama (15.67%) followed by Wenji (10.26%), Wolenchit (8.8%), and Mojo (7.01%) was recorded respectivly. Highest mortality rate was observed in Adama (5.99%) followed by Wenji (3.42%), Welenchit (2.4%) and Mojo (0%) respectively. Isolation and identification of the agent was conducted based on cell culture and PCR results. LSDV genome was extracted and identified in all 22 skin nodules by PCR. Furthermore, LSD causes a great economic loss in the study area. Questionnaire survey based assessment on protection of the vaccine showed that the current vaccine (KSGPV) used in the area was not protective and high percentage of morbidity (15.1%) and mortality (5.37%) rates were reported among vaccinated animals but efficacy test of the vaccine under laboratory protocol in six seronegative calves showed that the vaccine was immunologically protective.
BACTERIOLOGICAL STUDIES ON THE RESPIRATORY TRACTS OF APPARENTLY HEALTHY AND PNEUMONIC CAMELS (CAMELUS DROMEDARIES) IN SELECTED DISTRICTS OF AFAR REGION, ETHIOPIA
(2012-06) MU’UZ, GEBRU; Dr. Tesfaye Sisay, Dr. Genene Tefera
A cross-sectional study was conducted to isolate and characterize the normal bacterial flora and bacterial agents implicated in pneumonia from the respiratory tract of the apparently healthy and pneumonic camels in the selected districts of Asayita and Dubti woredas of Afar Region. A total of 532 samples including 384 nasal swabs, 74 lung tissues and the same number of corresponding tracheal swabs were collected for bacteriological examination from September 2011 to May 2012. Generally, 903 bacterial isolates that constituted 14 different genera were identified from both the field and abattoir based study. The 384 nasal specimens collected yielded a total of 641 bacterial isolates. CNS, 28.6%, Bacillus, 13.5%, S. aureus, 13.3% and E. coli, 7.8% were the leading bacterial species isolated from the nasal tracts of apparently healthy camels. Nasal swabs collected from the pneumonic camels revealed S. aureus, CNS, Bacillus species and K. pneumoniae at a rate of 28.0%, 11.7%, 11.3% and 7.0%, respectively. E. coli, 12.7%, Proteus species, 10.9%, and K. pneumoniae, 9.1% were recognized at higher proportions among the 55 bacteria identified from the normal lungs. On the other side, S. aureus, S. equi subsp. equi and P. multocida were the frequently encountered species in the pneumonic lungs with the incidence of 16.3%, 13.0% and 10.9%, respectively. The majority of the isolates colonized all the anatomical sites investigated. However, a general decrease in the isolation rate was observed as one goes down the respiratory passageways. There was a statistically significant difference between the health status of the camels as well as along the anatomical sites studied with the isolation rates of the major camel respiratory pathogens (p<0.05). Streptococcus equi subsp. equi, S. equi subsp. zooepidemicus and S. pneumoniae were identified using the Omnilog®-Biolog identification system at the Institute of Biodiversity Conservation, Addis Ababa. The majority of the strains of the camel respiratory pathogens were found susceptible to norfloxacin, streptomycin and gentamicin but resistant to the action of ampicillin and tetracycline on the invitro test. Further studies on the demonstration of the role of other microorganisms, the pathogenicity of S. equi subsp. equi, identification of the serotypes involved and development of polyvalent vaccine are recommended to allow the progress of preventive methods.
ISOLATION AND IDENTIFICATION OF Corynebacterium pseudotuberculosis FROM SUPERFICIAL LYMPHNODES OF SHEEP AND GOAT AT ORGANIC EXPORT ABBATOIR, MODJO ETHIOPIA
(2012-06) DANIEL, ABEBE; Dr. Tesfaye Sisay
Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis (CLA), a disease characterized by the formation of suppurative abscesses, particularly in superficial and internal lymph nodes, and in internal organs in small ruminants. The present study was conducted from November to April 2011/ 2012 only on the superficial lymph nodes and carcass of small ruminants. Out of 768 small ruminants slaughtered at Organic slaughterhouse during the study period, 82 (68 in goats and 14 in sheep) were found to have gross evidence of abscess or caseous lymphadenitis. The typical gross lesion is a discrete abscess distended by thick and often dry, greenish yellow or white, purulent exudates. The most frequent sites of abscesses in goats occurred in the prescapular, prefemoral and poplitial lymph node and carcass 34(5.54%), 24(3.91%), 2(0.33%) and 8(1.30%) respectively. In sheep 7(4.54%) in the prescapular , 5(3.25%) in prefemoral and 0% in poplitial lymph node and 2(1.23%) abscess on carcass were found. The study indicated that in both species young animals are more in number than adult, however, caseous lymphadenitis was found to be higher in adult than young animals in both species. There was statistically significant difference in the occurrence of CLA between age groups (P<0.05). Out of 68 bacterial cultures from goats 18 and 50, pure and mixed colonies, respectively, were obtained; while out of 14 bacterial cultures from sheep 4 and 10, pure and mixed colonies, respectively, were obtained. Corynebacterium pseudotubrculosis isolates were obtained from 59 out of 82 collected abscessed lymph nodes and carcass. Bacterial colonies were identified on the basis of morphological characteristics, primary and secondary biochemical tests, i.e. catalase, urease, trehalose, xylose, maltose, and glucose fermentation tests and reverse CAMP test (antagonistic haemolysis between C. pseudotuberculosis and Staphylococcus aureus). Isolates positive for catalase, urease, maltose, and glucose, but with inhibiting β- haemolysin of S. aureus by pospholipase D of C. pseudotuberculosis and negative for trehalose, and xylose were considered as C. pseudotuberculosis. The susceptibility pattern of C. pseudotuberculosis to antimicrobial agents varied among isolates. Out of 59 isolates of C. pseudotuberculosis isolated from lesions of caseous lymphadenitis in goats and sheep were susceptible to the antibiotics norfloxacin, tetracycline, doxycyline HCl and kanamycine.
ISOLATION AND MOLECULAR CHARACTERIZATION OF GOAT POXVIRUS FROM ETHIOPIAN SHEEP AND GOAT
(2014-06) Teferi, Degefa; Dr. Gezahegne Mamo, Dr. Esayas Gelaye
The present study was conducted from November 2013 to May 2014 in areas where suspected pox disease outbreaks occurred in sheep and goats population. Skin lesion samples were collected from six different geographical areas with the aim of isolation and molecular characterization of the virus responsible for causing pox lesion in sheep and goats. The study was employed questionnaire, outbreak search, virus isolation, and genotyping methods. The questionnaire survey indicated that sheep and goat pox is the most common disease in all study areas and the disease is more frequent during rainy season followed by spring and autumn seasons. Purposive sampling method was used to get samples for laboratory investigation. A total of six pox suspected outbreaks were assessed for virus isolation and genotyping during the study period. Out of 102 sheep examined, 35 sheep (34.3%) developed pox lesions on their skins where as from 50 goats examined eight goats (16%) were found to be positive for pox. Virus was isolated from 14 skin samples (n=16; 14 sheep and 2 goat). The virus developed characteristic pox virus cytopathic effect of cell syncytia, ballooning, aggregation and detaching of cells on Vero cell culture. Similarly, the conventional genotyping PCR revealed 14 out of 16 tested samples were positive by developing band of 172 bp (Goat poxvirus) whereas two of them could not produce any band on gel electrophoresis. The real-time genotyping PCR analysis also indicated that 14 samples were properly amplified and genotyped as goat poxvirus only while 2 samples not. Even though the existing knowledge suggested that Capri pox virus is strictly host specific, this genotyping assay confirmed that sheep are affected by goat pox virus similar to goats. Classification of poxvirus based on infected host in small ruminants has been found to be inconclusive. Thus, genotyping of the isolates should be conducted carefully instead of naming the virus genotype based on the name of animals from which the samples has been collected. Hence, further genotyping studies are needed to differentiate sheep pox virus and goat pox virus with respect to their host specificity in order to select appropriate vaccine candidate and challenge virus for the control of pox in the small ruminants.
ISOLATION AND ANTIMICROBIAL SUSCEPTIBILITY OF STAPHYLOCOCCUS AUREUS AND OCCURRENCE OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS (MRSA) IN MASTITIC DAIRY COWS IN THE SELALE/FITCHE AREA, NORTH SHOWA, ETHIOPIA
(2014-06) SHIMELS, TESFAYE; Dr.Bruk Tesfaye, Dr.Tesfaye Sisay
Bovine mastitis is of the most significant problems associated with high milk production loss in Ethiopia. Staphylococcus aureus is still a major cause of bovine mastitis. MRSA is any strain of Staphylococcus aureus that has developed resistance to beta-lactam antibiotics. It has been known by a significant public health problem infected animals with MRSA might serve as a potential source of human infection. This study was carried out with the aim that to determine the prevalence of Staphylococcus aurous mastitis from the total of clinical and subclinical mastitis and identify associated risk factors, isolates and identify Staphylococcus aurous and MRSA strains from mastitic milk samples and conduct in vitro antimicrobial susceptibility test on the isolates. Quarter milk samples from cows were examined to determine the prevalence of Staphylococcus aureus, MRSA and different antibiotic resistant pattern were determined in a cross-sectional study design. A total of 403 samples were collected and screened for the presence of S. aureus. The overall prevalence of mastitis at cow and quarter levels were 128 (83.1%) and 403 (65.42%) respectively. A total of 164 (40.69%) S. aureus isolates were obtained and out of these isolates 60 (36.6%) were found MRSA isolates during this study. The risk factors of mastitis like age group and pregnancy status had no effect on (p>0.05) Staphylococcus aureus isolation whereas, stage of lactation and previous mastitis history had significant effect on (p<0.05) isolates of S. aurous. A total of 61 isolate of S. aureus species were tested for antimicrobial sensitivity for 12 different types of antibiotics. The S. aureus isolates showed highest sensitivity towards Amoxicillin-clavulinic acid (80%), Chloroamphenicol (78.7%), Nitrofuration (73.8), Cefoxitin (67.2%), Sulphamethoxazole-trimethoprim (59%) and also uncommonly 70.1% of S. aureus isolates were found resistant to Vancomicin. The most frequent multidrug resistance pattern consisting of three drugs is exhibited for, gentamicin, ceftazidime and streptomycin with a resistance of 7 (9.46%) of the isolates. Sixty four (86.46% of the isolates) were resistant to different combinations of two or above tested antibiotics.
ISOLATION AND IDENTIFICATION OF METHICILIN RESISTANT S. aureus FROM BOVINE MASTITIC MILK IN AND AROUND WOLAITA SODO, SOUTHERN ETHIOPIA
(2014-06) Biniam, Tadesse; Dr. Biruk Tesfaye, Dr. Tesfaye Sisay
A cross sectional study was conducted from November 2013 to May 2014 in and around Wolaita Sodo town, Southern Ethiopia, to isolate and identify methicilin resistant S. aureus and their resistance to different antimicrobials and also identify risk factors associated with occurrence of dairy cow mastitis. A total of 257 dairy cows were included during the study period. Total of 1020 quarters were examined to detect clinical and subclinical mastitis by physical examinations of udder and milk and California mastitis Test (CMT), respectively. The prevalence of mastitis was 40.9%. Out of this, 4.66% and 36.18% were clinical and subclinical respectively. The univariate logistic regression showed that among potential risk factors considered from the farm attributes, age, milking hygiene, parity, lactation period, farm floor and previous mastitis treatment had significant (p=<0.05) effect on the prevalence of mastitis. However, breed was not a significant potential risk factor. 39 (15.1%) S. aureus was isolated and out of this, 8(3.11%) and 31(12.06%) were from clinical mastitis and subclinical mastitis respectively. The result showed a significant association of S. aureus with mastitis (p=0.025). The present study showed the resistance of S. aureus to penicillin G (100%), cefoxtin (71.8%), amoxicillin-clavulinic acid (61.5%), tetracycline (69.2%), streptomycin (66.7%), chloramphenicol (35.9%), sulphamethoxazole-trimethoprim (43.6%) and vancomycin (56.4%). In the present observation, 28 (71.8 %) S. aureus isolates not only showed MRSA but also multidrug resistance (MRSA) primarily to penicillin G, cefoxtin, tetracycline and streptomycin because of resistance to β-lactams and frequent use. Association of MRSA with age of cows was also highly significant (p = 0.000) and all MRSA were isolated from adult and old cows. 92.8% of MRSA isolates was found in previously mastitis treated animal showed significant association (p=0.001). The development of antimicrobial resistance is nearly always as a result of repeated therapeutic and/or indiscriminate use of them. Regular antimicrobial sensitivity testing helps to select effective antibiotics and to reduce the problems of drug resistance development towards commonly used antibiotics.
PREVALENCE AND ANTIMICROBIAL SUSCEPTIBLITY PROFILE OF SALMONELLA IN SLAUGHTERED CATTLE AND LACTATING COWS IN CENTRAL ETHIOPIA
(2014-06) Bulako, Chebo; Dr. Bedaso Mamo, Dr. Ashenafi Feyissa
The survey was conducted on 133 apparently healthy slaughtered cattle and 202 lactating dairy cattle at selected towns of central Ethiopia (Addis Ababa, Bishoftu, Adama, Holeta and Asella) from December 2013 to June 2014. The objectives were to estimate the prevalence and distribution of Salmonella in lactating cows and slaughtered cattle, Assess the antimicrobial resistance pattern of Salmonella isolates and find out some of the risk factors of milk and carcass contamination. A total of 984 samples from farms and abattoirs consisting of udder milk, tank milk, pooled buckets swab, pooled tank swab, feces from lactating animals, milkers’ hand swab, carcass swab, cecal content from slaughtered animals, mesenteric lymph node, pooled butchers’ hand swab, pooled carcass hanging materials swab and pooled knives swab were collected. The samples were examined for the presence of Salmonella following standard techniques and procedures outlined by the international organization for standardization. In a total of 335 animals examined, 29 (8.7%) were positive of these, 13(9.8%) were slaughtered cattle and 16 (7.92%) were lactating cows. In a total of 984 different samples Salmonella was isolated 66(6.71%). In 545 samples originated from farms Salmonella was isolated in 26(4.77%) of which 4(1.91%) was udder milk, 1(2.94%) tank milk, 1(2.94%) pooled buckets swab, 3(8.82%) pooled tank swab, 16(7.92%) feces from lactating animals and 1(2.94%) milkers’ hand swab. From 439 samples collected from abattoirs Salmonella was isolated in 40(9.11%) of which 13(7.10%) carcass swab, 7(5.34) cecal content from slaughtered animals, 6(12.72%) mesenteric lymph node, 4(15.38%) pooled butchers’ hand swab, 5(23.80%) pooled carcass hanging materials swab and 5(17.85%) pooled buchers’ knives swab. Salmonellae were detected from all test samples obtained from farms and abattoirs. Up on assessment of association of milk contamination with risk factors, carrier animals and Salmonella contaminated tanks were found to be potential risk factors. Up on assessment of carcass contamination with potential risk factors, carcass hoisted on Salmonella positive hanging materials was found to be four times more likely to be contaminated with Salmonella compared to carcass hoisted on Salmonella negative hanging materials. Total 66 isolates obtained from the study were tested for ten different antimicrobials that were commonly used in human as well as 2 animal treatment, and available in the market. 56 (84.8%) were resistant to one or more of the tested antimicrobials. Of the resistant isolates, 87.5% (49 of 56) of them developed resistant to more than one drug.
Escherichia Coli0157:H7: Prevalence and Sources of Contamination of Cattle Meat at Municipal Abattoir and Butcheries as Well as its Public Health Importance in Debre Brerhan, Ethiopia
(AAU, 2014-06) Abdissa, Rosa; Mamo, Bedaso(Dr
The study was carried out from November 20 13 to April 2014 with the objecti ves of determining the prevalence and source of contamination of E. coli 0157: H7 from municipal abattoir and butcher houses, to assess the public health importance of this organism and to lest the drug sensitivity pattern of the isolates in Oebre-Berhan. A total of 1,132 samples from abattoir and 40 samples from butcher hOllses were examined. Samples from abattoir included hide swabs, internal and external carcass swabs. fecal sample, intestinal mucosal swabs and environmental samples (carcass in contacts, i.c. knife, workers hand, and clothing). Likewise, the samples from butcher houses were swab from carcass, butcher man's hand, cutting board and knife. In addition, stool samples from suspect individuals visiting Debre-Berhan referral hospital were collected. The samples were transportcd in Buffered peptone waler to laboratory of the department of Biological science, Oebre Berhan University in ice box and scrutinized according to international standards. From 220 animals slaughtered, a total of 1100 sampl es were taken and only 6 (0.54%) were found to be positive of £. coli 0157:117. E. coli 0157:H7 was isolated from 2 (0.91 %) of hide swab samples, 3 (1.36%) of feces samples and I (0.45%) of intestinal mucosal swab. There were no isolate found from 32 environmental sampl es, 20 stool samples and 40 swab samples from butcher shops. Prevalence of E. coli 0157:H7 was significantly associated with the cleanness of the hide (P=0.036). All E. coli 0157:H7 isolates were then checked for their susceptibility pattern against ten selected antibiotics. The isolates were completely suscepti ble to 7 antibiotics tested, namely Tetracycline (TE, 30 Ilg), Chloramphenicol (C, 30Ilg), Sulfamethoxazole-Trimitoprim (SXT, 251lg), Ciprofloxacine (eIP, 5Ilg), Nalidixic acid (NA, 30llg), Kenamycine (K . 30llg) and Sterptomycine (S, JOllg) but they were resistant to Amoxicillin (AML, 25 Ilg). Though, the prevalence of E. coli 0157:1-17 in present study is low, the impact of the pathogen should not be underestimated.
ANTIMICROBIAL RESISTANCE TEST OF SALMONELLA ISOLATES FROM MILK AND FECAL SAMPLES OF APPARENTLY HEALTHY DAIRY CATTLE IN DEBREZEIT
(2014-06) Yemisrach, Mulugeta; Dr. Biruk Tesfaye, Dr. Getachew Tadesse
A cross sectional study to determine the antimicrobial profile of salmonella isolated from milk and fecal samples of apparently healthy cattle found in dairy farms of Debrezeit was undertaken from November 2013- April 2014. A total of 296 samples (148 fecal and milk each) were collected and processed in college of veterinary medicine and agriculture debrezeit. The overall prevalence of salmonella was found to be 12.8%. Prevalence of 2.0 and 10.8% was observed from milk and fecal samples respectively. The isolates were tested for the effect of 11 antimicrobial by disk diffusion technique they have indicated 89.5%, 100%, 42.1%, 63.3%, 15.8%, 10.5%, 31.6%,42.1%, 52.6% resistant to amoxacyline, tetracycline and gentamycin, kanamycin, trimetoprim, streptomycin, cotrimoxazol, chloramphenicol, nalidixic acid and cefoxitin respectively no resistance has been found for ciprofloxacin. However no statistical difference (P>0.05) was observed between milk and fecal samples. Totally 8 Multiple Drug Resistance (MDR) pattern were also observed. The highest MDR was for three antibiotics with the combination Amc, Te, Cn being more frequent. In general MDR to three, seven and eight antibiotics dominate the resistance patterns (31.6%, and 21.1% each). From this study we conclude that milk can be a potential source of drug resistant salmonella infection and multidrug resistance is developing due to unmonitored and inappropriate use of drugs in dairy farm which needs due consideration as it affects the dairy industry and the people at large.
Isolation and Molecular Characterization of Marek's Disease Virus isolates Circulating in Central Tthiopian Chickens
(Addis Ababauniversity, 2014-06) Demeke, Berhan; Ayelet, Gelagay (PhD)
Marek´s Disease (MD) is a lymphoproliferative and neuropathic disease of domestic chickens, and less commonly, turkeys and quails, caused by a highly contagious, cell-associated, oncogenic herpesvirus. In Ethiopia MD is believed to be introduced with the exotic and cross-breeds, and has been reported to be a potential threat to both local and exotic breeds in backyard and commercial farming systems. Therefore, the objective of this study was to isolate, identify and molecular characterization of MD virus circulating in the chicken population of the country. Clinical and post-mortem examination was carefully conducted from September, 2013 to December, 2013 in central Ethiopia on clinically diseased chickens suspected of MD virus infection. Representative post-mortem feather follicle and spleen samples were collected under sterile condition and virus isolation was performed using chicken fibroblast cell culture. Cell cultures inoculated with suspension of pathological samples developed characteristic MD virus cytopathic effect of rounding of the cells and small plaques. Further confirmation of the virus was conducted by conventional polymerase chain reaction using MD virus specific primers targeting to amplify the ICP4 gene on twelve samples and revealed the expected band size of 318 base pair of the 11 samples. Eleven positive PCR products were further subjected for sequencing using the amplification primers and the sequence analysis result using the available bioinformatics software’s confirmed that the chickens were infected with MD virus. Phylogenetic tree construction was performed to see the genetic relatedness of the present virus isolates with the reference MD virus strains retrieved from the Genbank and revealed that the virus infected the Ethiopian chickens were clustered under Gallid Herpes virus type 2. To our knowledge, the present study is the first report conducted on virus isolation, molecular characterization and sequencing of MD virus isolates in Ethiopia. xiii Further research work on isolation and molecular characterization of MD virus is recommended by observing chickens at all age groups showing clinical signs of the disease reared under backyard and commercial farming system. Finally, production of an effective MD vaccine in the country which could help in protecting the chickens from the circulating virus type is highly recommended. Key words: Marek’s disease, Marek’s disease virus, molecular characterization, polymerse chain reaction, virus isolation, sequencing
Department of Veterinary Microbiology, Immunology and Veterinary Public Health
(AAU, 2014-06) Muktar, Yimer; Mamo, Beda 0 ( Dr

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