Epidemiology analysis of bovine acute mastitis

• Main Authors: Mei, Nien-Tzu, 梅念祖
• Other Authors: Frank Chiahung Mao
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/82739908425694756933

碩士 === 國立中興大學 === 獸醫學系 === 85 === A survey was conducted from July,1996 to June,1996. Milk sample and clinicaldata of cows suffered from acute mastitis were collected from dairy farm in the middle and southern parts of Taiwan.108 cows and 117 quarter samples were analyzed in total. 110 strains were isolated from these samples. No pathogen wasisolated from 9 quarter samples and 2 isolates in the same sample were found in 2 cases. The distribution of important pathogens of bovine acute mastitis were as followed:Coliform bacteria 42.8%(53/110),Staphylococci 24.5%(24/110),Streptococci8.2%(9/110),Bacillus spp.5.5%(6/110), Actinomyces pyogenes 3.6%(4/110),Pseudomonas aeruginosa 2.7%(3/110)and other pathogens 7.3%(8/110). 53 Coliform strains isolated during the whole program were selected to analyzethe antibiotic resistant patterns among 22 antibiotics, the highest resistant percentage were found on the following antibiotic:Amoxicillin 98.11%(52/53),Ampicillin 98.11%(52/53),Oxacillin 98.11%(52/53) and Penicillin 98.11%(52/53).No resistant strains were found to be against Ceftazidime and Netilmicin .The same test were performed on 9 isolated streptococci. The highest resistent percentage was found in Streptomycin 100%(9/9) and than Colistin 88.9%(8/9)and Oxytetracycline 88.9%(8/9). No resistant strains were found to be against Amoxicillin,Bacitracin,Ceftazidime,Netilmicin, Oxacillin and vancomycin. Test also conducted on the isolated Staphylococcus aureus, the highest resistent percentage was found in Colistin 100%(3/3), and no resistant strains were found to be against Amikacin, Amoxicillin, Cephalothin, Enrofloxacin, Erythromycin, Gentamicin,Novobiotin, OXacillin, Penicillin and Vacomycin.On 24 isolated coagulase negative staphylococci, highest resistent percentage was found in Penicillin 79.17%(19/24),then Colistin 70.83%(19/24). No resistant strains were found to be againstAmikacin, Cephalothin, Enrofloxacin, Erythromycin, Gentamycin, Novobiotin, Oxacillin, Penicillin and Vancomycin. On 24 isolated coagulase negative staphylococci, highest resistent percentage was found in Penicillin 79.17%(19/24). No resistant strains were found to be ahainst Amikacin, Amoxixillin,Cephalothin,Enrofloxacin,Erythromycin, Gentamycin,Novobiotin,Oxacillin,Penicillin and Vancomycin. In the aspect of clinical investigation, higher percentage of occurrence was found in hot and humid season than in cold and dry one, and the differnet was significant (p<0.01). The perscntage of occurrence raise with cow age. significant difference was detected among among cohorts(p<0.01). Posterior quarters have higher percentage of acute mastitis than anterior quarters(p<0.01). The percentage of local changes in actue mastitis were as follows:swelling 88.9%(104/117), pain 81.2%(95/117), hot 53.9%(63/117) and redness 46.2% (54/117). The forms of quarter in acute mastitis was highest in milking machine udder 23.08% (27/117), lowest in udder in the thighs 17.09%(20/117). In the forms of teat, highest was found in short teat 42.74%(50/117), lowest was in conical teat 4.27%(5/117). 67.3%(68/101) of affected cows have body temperatures higher than 39.5 C, thus most cows in acute mastitis have higher body temperature. In 89.7%(105/117) of the cases the change of milk appearance, 91.5%(107/117) with third grade of CMT reaction,and 77.8%(91/117) with basic milk. Data from 41 coliform and 53 non- coliformacute mastitis cases were analyzed using the method of discriminate analysis.Among them 10 indicators are related to coliform acute mastitism including change in milk appearance, milk color yellow, a watery consistency, hot of the affected quarter, redness of the affected quarter, elevated rectal temperature,previous mastitis in quarter, mastitis occurs within 4 weeks after calving,white flake in milk, milking-machine shape udder. Using the 10 indicators,35 out of 41 cases of acute mastitis causing from coliform pathogens can be grouped correctly, and 48 out of 53 cases of non-coliform caused ones can also be grouped corectly, the accuracy percentage is 88.29%(sensitivity=0.85,specificity==0.90)