Infectious bovine keratoconjunctivitis: isolation of Moraxella bovis from two groups of young beef cattle in fly control field trials during 1981

Abstract

The rate of infection with Moraxella bovis was determined for two herds of calves during the course of a year. High infection rates with the haemolytic variant were found in the herds while they were housed during their first winter but this infection rate fell steadily after turnout. A rise in infections with the non-haemolytic variant was observed during this time. The animals remained free from clinical infectious bovine keratoconjunctivitis during the summer, unlike similar groups of animals in previous years. Immunity, weather and flies are considered for their possible relevance to this observation.

Epidemiology of Infectious Keratoconjunctivitis in Cattle in South‐east Ethiopia

“…Animals with any degree of eye problem were identified from their tag number or name. These animals underwent further close examination and their lesions were categorized as described previously ( Hughes and Pugh, 1970; Msika, 1982; Cox et al, 1984). The severity of the lesions was categorized as: mild (lacrimation, congestion of corneal and/or conjunctival vessels), moderate (relatively small sized white patches on the cornea but without vision impairment) and severe [pink mucous membranes, cloudy cornea, protruded eye ball (intact or burst), purulent ocular discharge, annoyance with photophobia and emaciation].…”

Evaluation of the clinical efficacy of subconjunctival injection of clindamycin in the treatment of naturally occurring infectious bovine keratoconjunctivitis

“…Animals with any degree of ocular disease were identified from their tag number. These animals underwent further close examination and their lesions were categorized as described previously 13–15 . Clinical findings were categorized as mild (lacrimation, congestion of bulbar and palpebral conjunctiva), moderate (chemosis, photophobia, small, pale white to yellow opacity on the center of the cornea but without vision impairment), and severe [chemosis, corneal opacity, corneal ulceration (intact or perforated), purulent ocular discharge, pain, photophobia and blepharospasm].…”

“…Identification After incubation, isolated strains were identified on the basis of the following criteria: colony characteristics; Gram‐staining reaction and morphology; cellular elongation in the presence of penicillin, growth characteristics in trypticase soy broth (TSB); motility; oxidase; catalase; growth on MacConkey agar; growth at 20 °C; tolerance to 5% NaCl; oxidation‐fermentation (O‐F); carbohydrate (glucose, lactose, arabinose, xylose, mannose) fermentation; indole and hydrogen sulfide production; nitrate reduction; urease; tween 80 and casein hydrolysis; coagulated serum; and gelatine liquefaction 15–18 …”

Caracterización del fenotipo piliado de <i>Moraxella bovis</i>

“…Como indicamos, la hemolisina es uno de los factores de virulencia más importantes de M. bovis ya que las bacterias no hemolíticas no pueden iniciar la etapa de colonización de la córnea bovina (Huges and Pugh, 1970;Cox et al, 1984;Lepper and Barton, 1987; y las cepas aisladas de animales que están enfermos son predominantemente hemolíticas . Por esto es que la hemolisina de M. bovis ha sido propuesta como un candidato a antígeno vacunal (Beard and Moore, 1994; Billson et al, 1994) al igual que el pili tipo IV.…”