Changes in the vaginal flora of goats following a short-term protocol of oestrus induction and synchronisation with intravaginal sponges as well as their antimicrobial sensitivity

The aim of this study was to characterise the changes in the vaginal flora of goats subjected to the induction and synchronisation of oestrus using intravaginal sponges (IVSs). Mucous samples were collected from the vaginas of 32 Toggenburg goats using sterile swabs. Samples were obtained on the day that the IVSs inserted (D0), the day they were withdrawn (D6), and 24 h (D7), 48 h (D8), and a week (D13) after the sponges were withdrawn. The samples were transferred to the laboratory in transport medium, inoculated on 5% sheep blood agar, and incubated at 37 °C (aerobic culture only). The susceptibility of the cultured bacteria to eight of the most frequently employed antimicrobial agents was determined using the disc diffusion method in Mueller-Hinton agar. Fewer colony-forming units (CFUs) were obtained from the samples that were taken before sponge insertion (D0) compared with those obtained on the other days. After the sponges were inserted, the number of CFUs obtained from the vaginal samples increased, reaching the highest value at the time of sponge withdrawal (D6), when 62.1% (18/29) of the samples yielded ≥105 CFU/ml. At this time, more than one type (genus) of bacterial colony was detected. The most prevalent bacterium belonged to the genus Staphylococcus sp., except at the time of sponge withdrawal, when the most prevalent bacterium was Escherichia coli. The results of this study demonstrated that changes in the prevalent bacterial isolate and the number of CFUs in the vaginal flora of goats subjected to a short-term protocol of oestrus induction and synchronisation using IVS occurred while the IVSs were present and that there was a rapid re-establishment of the normal microbiota after the IVSs were removed.