Abstract:In this work, we explore whether the ace gene of E. faecalis is beneficial to the biofilm formation by comparing the biofilm formation ability of E. faecalis ace positive and negative strains. The ability of biofilm formation of 46 clinical isolates of E. faecalis was detected by microtitration plate method, and the ace gene of E. faecalis was detected by PCR. The detection rates of ace gene of E. faecalis in biofilm positive and negative groups were compared. E.faecalis strains ATCC29212-ace+(clinical isolates),U8-ace-,EU8-ace-,ZU8-ace+ were cultivated in 96-well culture plate for 3hours,6hours,12hours,24hours,36hours,48hours, OD570 were detected after Gram crystal violet staining. The ability of biofilm formation of ace+ or ace- strains were detected and compared by microtiter plate assay; E. faecalis strains ATCC29212(ace+),U8-ace-,EU8-ace- and ZU8-ace+ strains were cultured on cover glasses in cell culture dish for 6-72 hours, the mean thickness and density of biofilms of ace+ or ace-E. faecalis strains at different incubation time were observed and compared by CLSM. It was shown that the detection rate of ace gene of Enterococcus in positive biofilm group was 76.67%, which was higher than that in negative biofilm group 31.25% (χ2= 9.04, P>0.05); all the OD570 value of wild strains ATCC29212(ace+)and transformed plants ZU8-ace+were greater than that of wild plants U8-ace- respectively at different culture time points, P<0.01, while there was no significant difference between the empty plasmid control strain and the wild strain, P>0.05; the mean thickness,density of biofilms of ATCC29212(ace+),ZU8-ace+ observed by CLSM were all greater than that of wild strains U8-ace- respectively (P<0.01). There was no significant difference between control strains and wild strains (P>0.05). It is concluded that E. faecalis ace might be in favor of the biofilm formation.
强华, 刘光英, 林任玺. 粪肠球菌ace阳性和阴性菌株体外生物被膜形成能力比较[J]. 中国人兽共患病学报, 2019, 35(7): 599-603.
QIANG Hua, LIU Guang-ying, LIN Ren-xi. Biofilm formation ability of Enterococcus faecalis ace positive and negative strains in vitro. Chinese Journal of Zoonoses, 2019, 35(7): 599-603.