Analysis of Biofilms Formation and Associated Genes Detection in Staphylococcus Isolates from Bovine Mastitis

Objective The objective of the study is to investigate biofilm forming ability, distribution of biofilm associated genes of the clinically isolated bovine mastitis Staphylococcus and the correlation of them. Methods Silver staining, SEM and crystal violet staining were conducted for the detection of biofilm forming ability in 24-well plates. Genes of bap, icaAD, icaBC, sar, agr, sigB, clfaA, clfaB, fnbpA and fnbpB were amplified by PCR. Results Formation of biofilm could be found macroscopically in 120 out of 137 strains by silver stainning, the biofilm formation rate of 87.6%. It showed that 5 strains didn’t adhere to the surface of silica gel by crystal violet staining, while the rest 132 ones did. Bap was amplified in 57 isolates and icaAD and icaBC in 43 and 54 strains respectively; sigB, sar and agr are amplified in 73, 49 and 38 isolates, and clfaA and clfaB in 76 and 50 strains respectively; fnbpA was present in 52 strains and fnbpB in 26 isolates. Conclusion It revealed that bap, sigB, sar, icaAD and icaBC may be crucial biofilm associated genes, for these genes are present more in biofilm-positive strains than in biofilm-negative strains. There is no obvious difference between the frequency of agr in biofilm-positive strains and that in biofilm-negative strains, which may because the role of agr in biofilm developmemt is still in controversial. The disAnalysis of Biofilms Formation and Associated Genes Detection in Staphylococcus Isolates from Bovine Mastitis