• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.399-405
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• 2004

Haemophilus somnus, Mycoplasma bovis and Pasteurella multocida were responsible for respiratory diseases in bovine. Methods for identifying these bacteria had poor sensitivity and specificity. In this paper, PCR assays were applied for rapid identification of H. somnus, M. bovis, P. multocida B:2 and P. multocida capsular types. The specific PCR products were amplified from H. somnus, but not from other bacteria. Ten-fold diluted H. somnus were mixed with P. multocida and then the mixed cultures were inoculated on agar plates. After incubation, PCR was performed with harvest from agar plates and could detect as few as 3.4 CFU/ml of H. somnus. The primers MboF and MboR produced an amplification product unique to M. bovis and sensitivity of PCR was as low as 100 pg of DNA. Only serotype B:2 of P. multocida, the causal agent of haemorrhagic septicemia in bovine, was specifically amplified in PCR among the 16 reference serotypes. The multiplex capsular PCR typing for P. multocida was produced the P. multocida specific product as well as the capsular serogroup-specific product. The present PCR assays should be useful for the rapid identification of bacterial pathogens from bovine respiratory diseases.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.427-432
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• 2004

The objective of this study was to determine the prevalence of pneumonic bacteria in lungs and nasal swabs of cattle with respiratory diseases. From 95 pneumonic lungs of slaughtered cattle, 41 (43.2%) positive lungs were yielded with 54 pneumonic bacteria, which corresponded to P. multocida (n = 34), A. pyogenes (n = 14) and P. haemolytica (n = 6). One-hundred sixty seven pneumonic bacteria were isolated from 195 nasal swabs in calves, 64.7% (108 isolates) belonged to P. multocida, 16.2% to A. pyogenes, 13.8% to P. haemolytica and 5.4% to H. somnus. Fifty percents (n = 6) of isolates from pneumonic lungs of calves were identified as P. multocida. All isolates of P. multocida belonged to type A according to hyaluronidase test. Antimicrobial susceptibility tests showed that most isolates of P. multocida and P. haemolytica were sensitive to amoxicillin/clavulanic acid, cephalothin, ciprofloxacin, enrofloxacin, fluorophenicol and norfloxacin. The emergence of antimicrobial resistant Pasteurella spp. observed in this study, however, might limit such application. According to histopathological examination, pneumonia by mycoplasma or/and bacteria accounted for 92.8% among 69 pneumonic lungs of slaughtered cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1461-1468
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• 2014

This study was aimed to examine the antibacterial and antioxidative properties of seven edible plants from Thailand to develop alternative antibiotics as feed additives. The plants include Citrus aurantifolia Swingle (Lime) fruits and its leaves, Sesbania grandiflora L. (Agati sesbania) leaves, Piper sarmentosum Roxb (Wild betal) leaves, Curcuma domestica Valeton (Turmeric) roots, Morinda citrifolia L. (Beach mulberry) leaves, Cassia siamea britt (Siamea cassia) leaves, and Cocos nucifera L. (Coconut) peels. The plants were extracted by methanol, n-hexane, chloroform, ethyl acetate, butanol and water. Antibacterial activities with minimum inhibitory concentration (MIC) were determined by agar diffusion assay against Escherichia coli, Burkholderia sp., Haemopilus somnus, Haemopilus parasuis, and Clostridium perfringens that were considered pathogenic strains in livestock infection. Methanol extracts of C. aurantifolia Swingle fruits and leaves showed the broadest spectrum of antibacterial activities except for C. perfringens. Butanol extract of S. grandiflora L. leaves showed the strongest activity against Burkholderia sp. with MIC, $135{\mu}g/mL$. P. sarmentosum Roxb leaves showed antibacterial activities against E. coli, Burkholderia sp. and H. parasuis. Ethyl acetate and water extracts from C. domesitca Valeton roots showed MIC of $306{\mu}g/mL$ and $183{\mu}g/mL$, respectively against only C. perfringens. Antioxidative activity was determined by 2-diphenyl-2-picryl hydrazyl photometric assay. The methanol extracts of C. aurantifolia Swingle fruits and P. sarmentosum Roxb leaves showed the highest antioxidant activity among all the extracts with 3.46 mg/mL and 2.70 mg/mL effective concentration 50% ($EC_{50}$) values, respectively. Total contents of phenolics and flavonoids were measured from the plant extracts. Methanol extracts of S. grandiflora L. and chloroform extracts of C. domestica Valeton were found to have the highest amount of total phenolics, 41.7 and $47.8{\mu}g/mL$, respectively. Flavonoid content of methanol extracts in S. grandiflora L. T was $22.5{\mu}g/mL$ and the highest among plant extracts tested. These results indicated that C. aurantifolia Swingle, S. grandiflora L., P. sarmentosum Roxb, and C. domestica Valeton have antibacterial and antioxidant activities and can be used as alternative antibiotics or potential feed additives for the control of animal pathogenic bacteria.