Equine infectious keratitis in Finland: Associated microbial isolates and susceptibility profiles

Abstract

ObjectiveTo retrospectively describe laboratory findings, treatment, and outcome associated with equine infectious keratitis in Finland.Animals and proceduresMedical records of horses diagnosed with infectious keratitis in University of Helsinki Equine Hospital from January 2007 to June 2018 were reviewed.ResultsForty‐seven cases were included. Keratomycosis was diagnosed in 27 eyes and bacterial keratitis in 20 eyes. Aspergillus flavus was the most frequent fungal isolate (9/17, 53%), followed by Cylindrocarpon sp. (3/17, 18%) and Aspergillus fumigatus (2/17, 12%). Susceptibility was tested for 10/11 Aspergillus sp. isolates; all were susceptible to voriconazole while only two were susceptible to amphotericin B. Cylindrocarpon sp. isolates were resistant to both agents. Streptococcus equi subsp. zooepidemicus was the most frequent bacterial isolate (9/19, 47%), followed by other streptococci (4/19, 21%). All 13 Streptococcus sp. isolates were susceptible to penicillin, and all tested isolates (n = 11) were also susceptible to chloramphenicol. Mean duration of medical treatment was longer in fungal keratitis (38 days) than in bacterial keratitis (25 days) (P < .001). Twenty‐six of the eyes underwent globe‐sparing surgery in addition to medical therapy. Recovery was achieved in 66% (31/47) of all cases and in 59% (16/27) and 75% (15/20) (P = .264) of cases with keratomycosis and bacterial keratitis, respectively.ConclusionsAlthough Aspergillus sp. and S zooepidemicus were the most frequently encountered isolates, cytology, culture, and susceptibility testing are essential to differentiate bacterial and fungal keratitis and guide the clinician to choose the most efficient treatment.

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

“…Bacteria were not always isolated when infection was clinically suspected (mucopurulent discharge, keratomalacia, stromal cellular infiltration, and/or anterior chamber inflammation) while bacteria were isolated in some cases when clinical signs of infection were not present. In accordance with previous published data based on culture‐dependent methods, gram‐positive bacteria were most commonly identified (80.6%) in horses with an infectious ulcerative keratitis in Belgium 3,9,11–14 . Staphylococcus spp.…”

“…A variation in bacterial isolate and antimicrobial susceptibility has been demonstrated to depend on geographical location, season, and previous antimicrobial therapy 3,9–11 . Currently, there are no publications on equine ulcerative keratitis in Belgium.…”

Epidemiological and Molecular Investigation of Ocular Fungal Infection in Equine from Egypt

“…Given the little difference on the frequency and the prevalence of the isolated fungi, Aspergillus flavus, Aspergillus fumigatus, and Aspergillus niger were the most common etiological agents have been isolated from eyes of healthy and diseased equine, which is consistent with several previous studies [35,40,41,43]. Similar studies revealed that Aspergillus and Fusarium counts for one-third of all major causes of traumatic keratitis [35,40,49], while some other fungal genera could be isolated such as Candida, Penicillium, and Alternaria [11,14,23,42]. In the same line, several previous works concluded that mixed infections of Aspergillus and Pseudomonas spp.…”

“…This may relate to the fact that a higher number of equines were examined in our study versus the majority of the previous reports worldwide [ 17 , 40 ]. Alternatively, the difference in the prevalence of fungal infection compared to our study might be attributed to the hypothesis that the seasonal variation and temperature conditions, housing and management conditions might influence the epidemiological pattern of keratomycosis [ 35 , 49 ]. Along the same line, equine fungal keratitis is usually recorded in warm and humid climate regions, which suggest that seasonal variation is an important factor influencing the occurrence of the disease [ 31 , 50 , 51 ].…”

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

“…Lagen Keratitiden vor, gehörten die isolierten Bakterien am häufigsten zu den grampositiven Gattungen Streptococcus und Staphylococcus (Keller und Hendrix 2005, Moore et al 1995, Mustikka et al 2020, Sauer et al 2003, sowie zu den gramnegativen Gattungen Pseudomonas (Keller und Hendrix 2005, Moore et al 1995, Moore et al 1983, Sauer et al 2003 und Acinetobacter (Moore et al 1995, Moore et al 1983 und zur Familie der Enterobacteriaceae (Moore et al 1995, Moore et al 1983.…”