Conjunctival aerobic bacterial flora in healthy Silesian foals and adult horses in Poland

Abstract

BackgroundCommensal bacterial and fungal flora of the conjunctival sac has been described in horses and other animals. The identification of commensal flora of the conjunctival sac may aid in the diagnosis of ocular inflammatory diseases, such as conjunctivitis or more severe ulcerative keratitis, common in horses. Moreover, damage of ocular protective barriers may lead to an opportunistic infection. The study was carried out in Silesian horses kept at a single breeding center in South-western Poland, in order to limit any breed-dependant and climate-dependant variables affecting the results. Following an ophthalmic examination that revealed no abnormalities, sterile swabs were collected from conjunctival sac in 26 adult horses and 11 foals. The obtained swabs were subjected to bacterial culture testing. In case of Staphylococcus spp. isolation, susceptibility to methicillin was evaluated.ResultsForty- three bacterial isolates, representing eleven genera of bacteria were cultured from 30 (81%) horses. Gram-positive bacteria were the dominant isolates (72%) (p < 0.001). The most commonly isolated Gram-positive bacteria were Staphylococcus spp., while Moraxella spp. were the most frequently isolated Gram-negative bacteria. There was no significant influence of sex and age on the frequency and type of microbial isolates.ConclusionsCommensal flora is present in the conjunctival sac of healthy horses in Poland. Age does not affect the abundance and type of microbial isolates.

Equine ulcerative keratitis in Belgium: Associated bacterial isolates and in vitro antimicrobial resistance in 200 eyes

“…isolated in this study were tested for methicillin susceptibility. Nearly 20% of all staphylococci were methicillin‐resistant and half of the Staphylococcus aureus were methicillin‐resistant (MRSA), whereas MRSA were not identified in previous reports of healthy or diseased horses eyes 3,9,11,13–15 . The high prevalence of MRSA in our ocular samples reflects the high frequency of horses carrying MRSA presented to Belgium equine hospitals.…”

“…This was in line with previous studies from Tennessee (USA), Switzerland, and Finland 3,11,13 . S. zooepidemicus is a β‐hemolytic coccus belonging to the Lancefield group C that is rarely found in conjunctival flora of healthy horses 15,18–20 . However, it is commonly found on mucus membranes of the upper respiratory tract and lower reproductive tract of healthy horses 21 .…”

Study on the current resistance of the ocular microflora of the horse – Suitable locally applicable antibiotics for the initial treatment of conjunctivitis and keratitis in the horse

“…Anzahl (Hampson et al 2018), bei einer Studie aus Polen niedriger (Zak et al 2018). Deutlich weniger positive Proben lagen bei einer Studie aus dem Vereinigten Königreich vor (Johns et al 2011).…”

“…In den Studien, die sich mit der bakteriellen Mikroflora des gesunden Pferdeauges beschäftigt haben, war die Mehrzahl der Isolate grampositiv (Andrew et al 2003, Araghi-Sooreh et al 2014, Cattabiani et al 1976, Gemensky-Metzler et al 2005, Hampson et al 2018, Johns et al 2011, Moore et al 1988, Zak et al 2018. Auch in dieser Arbeit war dies mit 55 % grampositiver Isolate der Fall -trotz Betrachtung erkrankter Augen.…”

“…Gramnegative Mikroorganismen konnten ebenfalls aus Tupfern gesunder Pferdeaugen angezüchtet werden, wenn auch seltener. Diese gehörten vor allem zu den Gattungen Moraxella (Andrew et al 2003, Cattabiani et al 1976, Gemensky-Metzler et al 2005, Moore et al 1988, Zak et al 2018, Acinetobacter (Cattabiani et al 1976, Gemensky-Metzler et al 2005, Johns et al 2011, Moore et al 1988 und Neisseria (Cattabiani et al 1976, Moore et al 1988.…”