Conjunctival bacterial and fungal flora in healthy horses in the UK

Abstract

The microbial species isolated are comparable with studies performed in other countries, although the frequency of Acinetobacter isolation was higher which may reflect a geographic difference. The topical antimicrobials gentamicin and chloramphenicol are appropriate first line antimicrobials for empirical treatment of corneal ulcers in the UK.

Bacterial culture and antibiotic sensitivity from the ocular conjunctiva of horses

“…Such discrepancy has been attributed to the ambient temperature and management to which the animal is subjected (PISANI et al, 1997;JOHNS et al, 2011); although, some authors have not identified any significant difference in the number or types of microorganisms isolated during different seasons of the year (ANDREW et al, 2003). Of the 200 samples collected in the present study, 131 (65.5%) showed bacterial growth (Table 1).…”

“…Similar findings were respectively reported by SANTOS et al (2009) andFOTI et al (2013) in studies with dogs and horses with healthy eyes. JOHNS et al (2011), meanwhile, reported the genus Acinetobacter as the most representative for the group of gram-negative bacteria, and did not identify Proteus mirabilis in their study. In accordance with these authors, we reported a high prevalence of Acinetobacter sp., probably due to the contamination of the environment around the horse's skin, besides being considered part of the normal microflora of the human skin.…”

“…In the literature, there is a variation of 52% to almost 100% with respect to the frequency of bacteria isolated from the ocular conjunctiva of horses without eye problems (VIDAL et al, 2010;JOHNS et al, 2011;FOTI et al, 2013;TAMARZADEH & ARAGHI-SOOREH, 2014). Such discrepancy has been attributed to the ambient temperature and management to which the animal is subjected (PISANI et al, 1997;JOHNS et al, 2011); although, some authors have not identified any significant difference in the number or types of microorganisms isolated during different seasons of the year (ANDREW et al, 2003).…”

“…Plates were incubated for 24h in an incubator, and growth inhibition around each disk was then analyzed, classifying the bacteria as sensitive, intermediate or resistant to the antibiotic. The criteria for the choice of antimicrobials testes were based on the active principles most frequently used in the ophthalmic routine of horses in the Federal District, in addition, topical gentamicin and chloramphenicol are the antibiotics indicated for the preventive treatment of corneal ulcers in horses (SAUER et al, 2003;WADA et al, 2010;JOHNS et al, 2011), with chloramphenicol being still effective against strains of MRS, an emerging infection among equines (KURODA et al, 2015).…”

“…In different animal species, including horses (ANDREW et al, 2003;JOHNS et al, 2011), mules (TAMARZADEH & ARAGHI-SOOREH, 2014), donkeys (FOTI et al, 2013), sheep (BONELLI et al, 2014), dogs (PRADO et al, 2005) and rabbits (ORIÁ et al, 2014). Bacterial population often isolated from healthy eyes is composed of gram-positive bacteria, although strains of methicillin-resistant to Staphylococcus (MRS) and gran negative strains, have also been identified (SANTOS et al, 2009;JOHNS et al, 2011;WILLCOX, 2013;MOUNEY et al, 2013). Some eye infections, however, can be caused by resident microorganisms, which become potentially pathogenic after their virulence is increased by external factors, such as trauma, stress, aging and reduction in commensal microbiota (COGEN et al 2008;WILLCOX, 2013).…”