An investigation of colonization of the conjunctival sac of sheep by bacteria and mycoplasmas

Diseases of Iberian ibex (Capra pyrenaica)

Iberian ibex (Capra pyrenaica) is an ecologically and economically relevant medium-sized emblematic mountain ungulate. Diseases participate in the population dynamics of the species as a regulating agent, but can also threaten the conservation and viability of vulnerable population units. Moreover, Iberian ibex can also be a carrier or even a reservoir of pathogens shared with domestic animals and/or humans, being therefore a concern for livestock and public health. The objective of this review is to compile the currently available knowledge on (1) diseases of Iberian ibex, presented according to their relevance on the health and demography of free-ranging populations; (2) diseases subjected to heath surveillance plans; (3) other diseases reported in the species; and (4) diseases with particular relevance in captive Iberian ibex populations. The systematic review of all the information on diseases affecting the species unveils unpublished reports, scientific communications in meetings, and scientific articles, allowing the first comprehensive compilation of Iberian ibex diseases. This review identifies the gaps in knowledge regarding pathogenesis, immune response, diagnostic methods, treatment, and management of diseases in Iberian ibex, providing a base for future research. Moreover, this challenges wildlife and livestock disease and wildlife population managers to assess the priorities and policies currently implemented in Iberian ibex health surveillance and monitoring and disease management.

Infectious keratoconjunctivitis in free-ranging mule deer in Wyoming: a retrospective study and identification of a novel alphaherpesvirus

We describe the clinicopathologic findings, relative prevalence, and pathogens associated with infectious keratoconjunctivitis in mule deer ( Odocoileus hemionus) in Wyoming. Seventeen cases with ocular lesions were identified among 1,036 mule deer postmortem submissions (1.6%) in an ~16 y period. Sixteen cases were observed in winter and most were in male (15 cases) and juvenile (13 cases) deer. Blindness was the most commonly reported clinical sign (10 cases). A herpesvirus was detected only in the 4 cases of bilateral necrotizing bulbar conjunctivitis. Phylogenetic analysis of glycoprotein amino acid sequences consistently identified this virus as a novel alphaherpesvirus. In 2 of these herpesvirus-positive cases, Actinomyces sp. and Moraxella ovis were also identified. Trueperella pyogenes was identified in 4 cases of unilateral ulcerative keratitis, keratoconjunctivitis, and panophthalmitis. M. ovis was cultured from 3 cases of bilateral conjunctivitis and keratoconjunctivitis. In the remaining cases, isolates included Moraxella bovis (1 case), Staphylococcus sp. and Streptococcus sp. (2), Flavobacterium sp. and Pseudomonas sp. (2), Escherichia coli and Enterobacter sp. (1), and bovine viral diarrhea virus 1 (1). No pathogens were identified in 2 cases. The relative prevalence of keratoconjunctivitis in mule deer in Wyoming appears to be low, and this disease is most commonly associated with infection by a novel alphaherpesvirus, T. pyogenes, and M. ovis.

Long-term dynamics of Mycoplasma conjunctivae at the wildlife-livestock interface in the Pyrenees

Functional roles of domestic and wild host populations in infectious keratoconjunctivitis (IKC) epidemiology have been extensively discussed claiming a domestic reservoir for the more susceptible wild hosts, however, based on limited data. With the aim to better assess IKC epidemiology in complex host-pathogen alpine systems, the long-term infectious dynamics and molecular epidemiology of Mycoplasma conjunctivae was investigated in all host populations from six study areas in the Pyrenees and one in the Cantabrian Mountains (Northern Spain). Detection of M. conjunctivae was performed by qPCR on 3600 eye swabs collected during seven years from hunted wild ungulates and sympatric domestic sheep (n = 1800 animals), and cluster analyses of the strains were performed including previous reported local strains. Mycoplasma conjunctivae was consistently detected in three Pyrenean chamois (Rupicapra p. pyrenaica) populations, as well as in sheep flocks (17.0% of sheep) and occasionally in mouflon (Ovis aries musimon) from the Pyrenees (22.2% in one year/area); statistically associated with ocular clinical signs only in chamois. Chamois populations showed different infection dynamics with low but steady prevalence (4.9%) and significant yearly fluctuations (0.0%– 40.0%). Persistence of specific M. conjunctivae strain clusters in wild host populations is demonstrated for six and nine years. Cross-species transmission between chamois and sheep and chamois and mouflon were also sporadically evidenced. Overall, independent M. conjunctivae sylvatic and domestic cycles occurred at the wildlife-livestock interface in the alpine ecosystems from the Pyrenees with sheep and chamois as the key host species for each cycle, and mouflon as a spill-over host. Host population characteristics and M. conjunctivae strains resulted in different epidemiological scenarios in chamois, ranging from the fading out of the mycoplasma to the epidemic and endemic long-term persistence. These findings highlight the capacity of M. conjunctivae to establish diverse interactions and persist in host populations, also with different transmission conditions.

Evaluation of conjunctival bacterial flora in a herd of goats in the Midwestern United States

OBJECTIVE

To identify conjunctival bacterial flora in healthy adult and newborn kid goats in the Midwestern United States and to compare vaginal and ocular surface flora in dam-kid pairs.

ANIMALS STUDIED

Thirty mixed-breed (crosses between Boer, Kiko, and Syfan Spanish) goats, 20 adult does and 10 newborn kids.

PROCEDURES

One eye of 15 adult goats (n = 15 eyes) and 5 kids (n = 5 eyes) was randomly selected. A subset of 5 adults (n = 10 eyes) and 5 kids (n = 10 eyes) underwent bilateral sampling. Each recently kidded dam's vaginal canal (n = 10) was also sampled. Two swabs were collected from each sample site for aerobic bacterial culture and Mycoplasma and Chlamydia spp. PCR.

RESULTS

Of the animals with positive cultures, Staphylococcus and Streptococcus were the most common bacterial genera from the conjunctival sac of adult (16/17; 94%) and kid (5/5; 100%) goats; three adults and 5 kids had no growth of bacteria on aerobic culture. Moraxella bovoculi was the most common single bacteria in adults, in 9 eyes (36%) of 8 animals (40%). Staphylococcus equorum was identified in all 5 kids with positive cultures. Mycoplasma sp. DNA was detected in 7 animals. Chlamydia sp. DNA was not detected in any sample. Four of 10 dam-kid pairs had identical bacteria isolated from the dam's vaginal sample and the kid's conjunctival sample.

CONCLUSIONS

Staphylococcus and Streptococcus were the most common conjunctival bacterial genera in this goatherd. Moraxella bovoculi was the most common single bacteria isolated from adults, and Staphylococcus equorum was the most common bacteria in kids. Mycoplasma sp. occurred infrequently at the ocular surface of adult and kid goats. A convincing association between dam-kid vaginal-conjunctival samples was not identified.

Bacteriological investigation of infectious keratoconjunctivitis in Norwegian sheep

Contagious keratoconjunctivitis is a rather common disease in Norwegian sheep. Since the knowledge of its aetiology is limited, the present study was performed to determine the microorganisms involved. Local veterinarians throughout the country collected conjunctival swabs from both sick (n = 43) and healthy (n = 42) sheep on 15 farms with outbreaks of ovine keratoconjunctivitis, and further from healthy sheep (n = 50) on 17 farms not showing any signs of conjunctival disease. All samples were cultivated for bacteria and mycoplasma.

Listeria monocytogenes was isolated from 3 cases (1%) in one single herd. Staphylococcus aureus (5%), Corynebacterium spp. (2%) and Escherichia coli (4%) were isolated only in herds with keratoconjunctivitis, but from both sick and healthy animals. Moraxella (Branhamella) ovis was isolated from 28% of sampled animals in affected herds and from 10% of sampled animals in healthy herds. The corresponding numbers for Moraxella spp. were 9%/12%, for Pseudomonas spp. 7%/8%, for Staphylococcus spp. 22%/22%, for Bacillus spp. 12%/14%, for Micrococcus spp. 6%/2% and for Streptococcus/Enterococcus spp. 2%/2%. Mycoplasma conjunctivae was isolated from 16 animals with keratoconjunctivitis (37%) and from 3 animals without clinical signs (7%) in farms with keratoconjunctivitis. In farms without clinical signs of keratoconjunctivitis, M. conjunctivae was isolated in 4 animals (8%).

To our knowledge, this is the first time M. conjunctivae has been isolated in Norway. Other predisposing agents found were Moraxella (Branhamella) ovis and Listeria monocytogenes. The etiological importance of different microorganisms in ovine keratoconjunctivitis seems to vary; some are probably only present as secondary invaders. Other possible causes of ovine keratoconjunctivitis in Norway, such as Chlamydia psittaci, remain to be investigated.

Mycoplasma infections in small ruminants

Mycoplasmas have complex mechanisms of antigenic variation that allow them to evade the immune system. These organisms cause a variety of clinical syndromes that can have a significant economic effect on small ruminant production. The syndromes range from acute septicemia and death to chronic infection resulting in decreased production. Recent research findings have shed light on the means by which these organisms evade the host immune response and cause or contribute to the development of disease in the host. This article provides a review of the pathogenesis, clinical signs, and treatment options for common disease syndromes involving Mycoplasma spp. in small ruminants.