Distribution of Major Pathogenic Bacteria of Cow Mastitis in Milk

[ Objective] To observe the distribution of major pathogenic bacteria of cow mastitis in milk in vitro. [ Method] The Staphylococcus auo reus and Escherichia coil （ E. coil） were added into the milk. After standing for 8, 12 and 24 h at 4 ℃, the milk were divided into upper, middle and lower three equal parts. The bacterial counts distributed in the three parts of milk were respectively determined by plating colony-counting method. [ Result] The counts of these two pathogenic bacteria in upper milk were higher than that in middle and lower milk significantly （ P 〈 0.001 ）, and no significant difference was found between middle milk and lower milk. [ Conclusion] The pathogenic bacteria of cow mastitis can float with fat droplet in milk and then invade into the deeper tissue of mammary gland.

Effect of Chinese Herbal Medicine on Pathogenic Bacteria of Cow Mastitis

[Objective]The paper was to analyze the clinical therapeutic effects of Chinese herbal medicine on pathogenic bacteria of cow mastitis.[Method]Eight Chinese herbs and three compound extracts were selected for the treatment of cow mastitis.Four kinds of pathogenic bacteria were successfully isolated from cows with mastitis by flat perforation irrigation method and tube double dilution method.In addition,in vitro antibacterial test was carried out,and in vitro inhibitory effects of single and compound Chinese medicine extracts on pathogenic bacteria causing cow mastitis were studied.[Result]A total of seven Chinese herbs had good inhibitory effect,such as Taraxacum mongolicum,Viola yedonensis and Polygala japonica,which received good effect of activating blood circulation and removing blood stasis,clearing away heat and toxic materials.[Conclusion]As good Chinese herbal medicines,T.mongolicum,V.yedonensis and P.japonica could be popularized.

First Report in China on the Identification and Drug Sensitivity of Mycobacterium elephantis Isolated from the Milk of a Cow with Mastitis

Objective In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study. Methods Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction （PCR） and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay. Results Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacteriurn elephantis （M. elephantis）. The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline. Conclusion To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China.

Multiple PCR for Detection of Subclinical Mastitis in Dairy Cow

[ Objective] To develop a rapid, sensitive, specific and accurate diagnostic method for subclinical mastitis in dairy cow. [ Method] A total of 70 samples of suspected clinical mastitis cows were detected in gene level by multiple PCR. [Result] The 58 samples were positive with the developed multiple PCR method and the positive rate was 82.5% （58/70）. The 53 samples were positive with the traditional biochemical method and the positive rate was 75.5% （53/70）. As a result, the coincidence rate of both methods was 92%. [ Conclusion] The multiple PCR method is rapid and specific for the detection of pathogenic subclinical mastitis in dairy cow.

Isolation and Identification of Pathogenic Bacteria Causing Bovine Subclinical Mastitis in Eastern Hebei Province

In this study, the milk samples of 1 021 cows in eight dairy farms in Eastern Hebei Province were collected and detected with LMT reagent and somatic cell count for subclinical mastitis. Pathogenic bacteria in subclinical mastitis positive milk samples were isolated and identified.The results showed that 60.63%（619/1 021） of the sampled cows were diagnosed with subclinical mastitis, and mixed infections accounted for 88.21%（546/619） of the cases. In addition, 82 strains of 14 species were isolated from the subclinical mastitis positive milk samples, including 36 strains of Staphylococcus（43.90%）, 33 strains of Streptococcus（40.24%）, 8 strains of Enterobacteriaceae（9.76%） and 5 strains of Corynebacterium（6.10%）, respectively. The results proved that Staphylococcus aureus and Streptococcus agalactiae are the main pathogenic bacteria causing bovine subclinical mastitis in Eastern Hebei Province.