Septic keratitis in dogs, cats, and horses in Switzerland: associated bacteria and antibiotic susceptibility

Abstract

Objective To evaluate the most common bacterial pathogens associated with septic keratitis in veterinary patients from Switzerland. The second objective was to analyze antibiotic susceptibility test results of the identified bacterial pathogens. The third objective was to evaluate potential breed predispositions to septic keratitis. Procedures Two hundred and fifty-five cultures and antibiotic susceptibility reports from dogs, cats, and horses with septic keratitis that were presented to the University of Zurich Veterinary Medical Teaching Hospital between 2009 and 2013 were reviewed. Odds ratios for the risk of having a septic keratitis were estimated for all dog and cat breeds compared to the general nonbrachycephalic hospital population. Results Ninety-six, 29, and 31 positive cultures were obtained from 89 canine, 28 feline, and 29 equine eyes, respectively. Repeat sampling accounted for the differences in numbers. Negative culture results were obtained in 50, 31, and 18 cases. Staphylococci and streptococci accounted for 66% of the isolates in dogs and 80% of the isolates in cats and horses. Staphylococcus spp. had a higher percentage of fluoroquinolone-resistant isolates compared to previous reports. Brachycephalic breeds had elevated odds ratios for the presence of septic keratitis. Conclusion Identified bacterial pathogens and their prevalence as well as the elevated odds ratios for septic keratitis in brachycephalics are roughly consistent with previous studies. Based on systemic breakpoint data, resistance to commonly used topical antibiotics, including the second-generation fluoroquinolones, was found.

Outcome of medical therapy for keratomalacia in dogs

“…, Suter et al . ). These studies suggest that antimicrobial therapy before susceptibility results are available in suspected cases of bacterial keratitis should include an antimicrobial from each susceptibility pattern.…”

“…Knowledge of the common pathogenic species and their differing antimicrobial susceptibilities in various geographic locations is important to assist in the choice of antimicrobial agents. Even though the antimicrobial susceptibility results often conflict between studies, the susceptibility patterns of Gram-positive cocci and P. aeruginosa to antimicrobials are found to be largely different (Tolar et al 2006, Lin & Peterson-Jones 2007, Hindley et al 2016, Suter et al 2018. These studies suggest that antimicrobial therapy before susceptibility results are available in suspected cases of bacterial keratitis should include an antimicrobial from each susceptibility pattern.…”

“…to fluoroquinolones and thus suggested an antimicrobial therapy protocol using a combination of ciprofloxacin with either chloramphenicol or a compounded cephalosporin. Suter et al (2018) described a high resistance rate of Staphylococcus spp. to fluoroquinolones and recommended the use of the neomycin-polymyxin B-bacitracin/gramicidin tripleantibiotic combination.…”

Methicillin-resistant coagulase-negative staphylococci in healthy dogs

“…The role of CoNS as animal pathogens is less understood (Karakulska et al 2012). Some species of CoNS are involved in disease; in pets they typically cause bacteraemia, pneumonia, rhinitis, furuncles, abscesses, pyoderma, keratitis, conjunctivitis, otitis externa and uterine infections (Kloos and Bannerman 1995;Litster et al 2007;Hariharan et al 2009;Suter et al 2017).…”

Streptococcus canis multilocus sequence typing in a case series of dogs with ulcerative keratitis

“…In a recent study by Suter et al, 2018, Streptococcus spp. were recovered from 25% of dogs with septic keratitis of which 76% were beta‐hemolytic streptococci . Only one case isolated S canis ; however, it was not reported if the subspecies of the other beta‐hemolytic streptococci had been identified in this study.…”