Comparison of the efficacy of enrofloxacin and lactobacillus plantarum cell-free supernatant treatments on vaginitis in ewes

Abstract

The aim of the study was to investigate the effect of different intravaginal treatment strategies on the vaginal discharge score, vaginal microbiota, bacterial and Enterobacteriaceae counts in nulliparous Merino ewes. All ewes (n=45) received intravaginal sponges containing 60 mg medroxyprogesterone acetate for 7 days and allocated into three equal groups (n=15). Sponges were injected Lactobacillus plantarum cell-free supernatant (SUPER), enrofloxacin (ENRO), or physiologic saline (CON) prior to sponge insertion. At sponge removal, 500 IU equine chorionic gonadotropin (eCG) were administered in all ewes. For the detection of vaginal microbiota, bacterial and Enterobacteriaceae counts, samples were collected prior to sponge insertion, at sponge withdrawal, and 48 h later after sponge withdrawal. Vaginal discharge score was not different in ENRO (2.26±0.18) and SUPER (2.20±0.14) compared to CON (2.46±0.16). The time-dependent alteration was significant for the mean bacterial and Enterobacteriaceae count in all groups (P<0.05). Bacterial counts were found to be lower in ENRO (5.50±0.17) than SUPER (6.31±0.19) and CON (6.07±0.15) at sponge removal (P<0.05). In addition, SUPER (3.74±0.21) and ENRO (3.49±0.27) had lower Enterobacteriaceae counts compared to CON (4.78±0.21) at sponge removal (P<0.01). The most frequently isolated bacteria species were Trueperella pyogenes (28.9%) and Escherichia coli (46.7%). In conclusion, treatment with enrofloxacin or cell-free supernatant decreased the Enterobacteriaceae counts in ewes. Comprehensive studies are needed to assess the effectiveness of lactic acid bacteria as an antibiotic-free treatment strategy on vaginitis in ewes that were synchronized with progesterone impregnated intravaginal sponge.