Molla, Bayleyegn PhD.Wakwoya, Assefa2021-10-202023-11-082021-10-202023-11-082005-06http://etd.aau.edu.et/handle/123456789/28265A cross-sectional bacteriological study of goal milk with special reference mastitis was carried out from September 2004 to March 2005 in Adami-Tulu Jiddo Kombolcha district A total of 680 milk samples were colleted from 30 flocks having 340 lactating goats.The Prevalence of mastitis was 69.4% at goat level and 55% at halve level. The prevalence of clinical mastitis at animal level was 67.1% and 53% respectively. of all the flocks examined 30(100%) at an least one animal was found infected with a mastitis pathoge. The flock prevalence ranged from 17.5% to 100% of animals and from 11.8% to 95% of the halves. Two hundred seventy eight (40.9%) milk samples were CMT positive Considering culture as a gold standard the sensitivity. Specificity and agreemen were 66.9% 90.9 and 0.56 respectively This indicates that CMT can be used for detecaion of subclinical mastitis in indigenous goats. A total of 405. isolates were identified from 374 halves of 236 goats and they were diversified in species .The major organisms isolated were Staphylococcus spp.representing (22.5%) of the total isolates and 57.1% of the Staphylococcus species Staphylococcus epidermidis accounted for 9.6% of the total isolates and 57.1% of the Staphylococcus species Staphlococcus epidermidis accounted for 9.6% of the total isolates and 42.9% of the Staphylococcus spp Bacillus spp.were the second frequently isolates bacterial spp accouning for 10.4% of the total isolates.other bacteria isolated were E.coli (7.9%), P. aeuroginosa (7.9%) K pneumoniae (5.7%) Acinetobacter spp. (4.9%). Micrococcus spp (4.7%).C bovis (4.%).C ulcerans (4%). B cereus (3.5%). Streptococcus spp. (3.5%). A pyogenes and E. aerogenes each (3.2%). C pseudouberculosis (3%). S.marscenes (2.7%). P. mirablis (1.2%) R.equi (1.2%). C freundii.C diversus Actinobacillus equlli and P. hemolytica (each 0.9%). Y enterocolitica and Candida albicans (each 0.5%).Enterococcus fecalis, E agglomerans pseudotuberculosis p vulgaris and p multocida (each 0.3%) Drug susceptibility test was conducted on frequently isolated bacteria and major pathogenic species against eleven antimicrobials (Oxoid. Hamshire. England) .All S.aureus spp. (100%),17 (43.6%) S.epidermidis, 14 (100%) Streptococcus spp. 13 (100%) A pyogenes. 10 (71.4%) B. methicillin. cefoxitin. naidixic acid. erythromycin. cloxacillin. sulfonamide. chloramphenicol. gentamycin. penicillin G. streptomycin and oxytetracycline. Penicillin G was tested only for Staphylococcus spp. When considering the over all antimicrobial resistance pattern, 75.7% of the tested ioslates were susceptible to the antimicrobials. The most effective drugs were gentamycin. Polymixin B.sulfonamide and erythomycins.Nalidixic acid, cloxacillin. Methicillin and streptomycin were less effective against the tested pathogens. The most resistant bacteria were K. pneumoniae and E.aerogenus. However they were 100% susceptible to polymyxin B.nalidixic acid and gentamycin. Escherichia coli were resistant to methicillin.erythromycin and cefoxitin similar to K.pneumoniae and E.aerogens. The most effective drug against E coli were polymyxin B. nalidixic acid and gentamycin Corynebacterium species and Arcanobacter pyogenes were generally susceptible to all isolateas of S.aureus were susceptible to sulfonamide and gentamycin. Abous 82.7% of the S. aureus spp. Were susceptible to methicillin whereas 17.3% were resistant. Host risk factors such as udder characteristics (pendulous or non pendulous) and parity has got relation (p<0.05) with prevalence of mastitis High producing goats with pendulous udder and multiparious goats were more susceptible intrammary infection.enLactating goats,mastitis, prevalence,CMT,Other