Identification Of Pathogenic Bacteria Isolated From Dairy Cow Mastitis In Ningxia And Virulence Gene Analysis Of S. Aureus

The study are 94 heads of clinical mastitis cows and other 70 heads of recessive mastitis cows which came from different dairy farm around to Yinchuan (that five of them in the area of Yinchuan, seven of them in southern area and other five of them in the northern area).40 kinds of bacteria were identified from 159 strains of pathogenic bacteria which separated from milk samples of clinical mastitis cow, which included 41 strains of staphylococcus aureus (25.79%),6 strains of streptococcus (3.78%), other 20 kinds of G+ cocci strains (12%),74 strains of G- bacilli (46%) and 18 strains of yeast (11.32%).33 kinds of bacteria were identified from 94 strains of pathogenic bacteria which separated from milk samples of recessive mastitis cow, which included 28 strains of staphylococcus aureus(29.79%),2 strains of streptococcus suis (2.13%), other 15 stains of G+ cocci strains (15.96%), and 45 stains of G- bacillus (47.87%). Drug sensitive test were operated to 12 strains of bacteria and 7 strains of fungi which had high detection rate by 15 kinds of antibacterial drugs and 4 kinds of antifungal drugs. The experiment found that the species of pathogenic bacteria which could caused mastitis for dairy cow showed diversified and complicated trend. It is different with three main bacteria for staphylococcus aureus, streptococcus, and e. coli in usual mind that most of infections are mixed by two or more than two kinds of bacteria. The species of bacteria for mastitis presents different distribution in different areas, even in the same area, even the same dairy farms, pathogenic bacteria species may also be affected by the facts of operation specification and environmental health.Testing of 14 kinds of virulence genes of staphylococcus aureus which are nuc, nuc, Hla、Hlb, fnbp A, fnbp B and nine enterotoxin’s genes. The result shows that the detection rate of nuc, Hla、Hlb, fnbp A, fnbp B and SEI gene were higher, and the detection rate of SHE, SEA, SEB, the SEC, SED, SEG, SEJ gene were lower or can not found simultaneously. It prompt that the gene of nuc, Hla、Hlb, fnbp A, fnbp B and SEI are main species of pathogenic factor of dairy cow mastitis in the region of ningxia.