SEARCH · PubMed Health

Results for “Keratoconjunctivitis, Infectious”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

PubMed1986

Infectious bovine keratoconjunctivitis: contact transmission.

The transmission of Moraxella bovis was studied in calves in the absence of the face fly (Musca autumnalis) or environmental conditions that might insult the eye. Thirty calves were placed in 10 groups of 1 experimentally infected calf and 2 contact calves each. Over 40 days, only 1 eye in 1 contact calf developed clinical infectious bovine keratoconjunctivitis. The organism was recovered in only 8 of 20 contact calves, whereas infection and disease occurred in all experimentally infected calves. Transmission of M bovis occurring in the absence of some other intervening factor was probably of minimal importance. Seemingly, herd preventive treatment would be most effective when flies and environmental factors are at a minimum.

Animals↗

PubMed1986

Infectious bovine keratoconjunctivitis: evidence for genetic modulation of resistance in purebred Hereford cattle.

A vaccination study was conducted in a herd of purebred Hereford cattle representing 4 selection (genetic) lines. For each of 2 years, half of the cattle were vaccinated with a pilus-enriched Moraxella bovis bacterin. Cows were vaccinated before parturition, and calves were vaccinated at 2 to 3 months of age. None of the cattle was vaccinated for 1 year preceding and 1 year after the 2 years in which cattle were vaccinated. There was a significantly (P less than 0.05) lower percentage of infectious bovine keratoconjunctivitis (IBK) in calves during years cattle were vaccinated than during years cattle were not vaccinated. During years cattle were vaccinated, there were lower percentages of IBK in vaccinated calves when compared with the percentages of IBK in nonvaccinated calves. When calves were compared on the basis of selection lines, regardless of the vaccination group, there were consistent differences in the percentages that developed IBK. Although calves with pigmented and nonpigmented eyes (representing all 4 genetic lines) developed IBK, the genetic line of calves with the most pigmented eyes had the lowest (P less than 0.05) percentage of IBK. Also, across all genetic lines, there was less IBK in pigmented eyes than in nonpigmented eyes. Seemingly, vaccination of dams, before parturition, and young calves reduced the occurrence of severe IBK in a herd situation under natural exposure conditions. The resistance or susceptibility in cattle under good management may be influenced by genetic factors.

Animals↗

PubMed1995

The protective efficacy of cloned Moraxella bovis pili in monovalent and multivalent vaccine formulations against experimentally induced infectious bovine keratoconjunctivitis (IBK).

Calves were vaccinated with cloned Moraxella bovis pili of serogroup C (experiment 1) or B (experiment 2) either as a monovalent formulation or as part of a multivalent preparation with pili of six other serogroups. Within 4 weeks of the second vaccine dose vaccinated calves and non-vaccinated controls were challenged via the ocular route with either virulent M. bovis strain Dal2d (serogroup C) or M. bovis strain 3WO7 (serogroup B) in experiments 1 and 2, respectively. Calves vaccinated with multivalent vaccines had significantly lower antibody titres than those vaccinated with monovalent preparations. Nevertheless, the levels of protection against infectious bovine keratoconjunctivitis (IBK) achieved with multivalent vaccines were 72% and 83% for the groups challenged with M. bovis strains of serogroups B and C, respectively. The serogroup C monovalent vaccine gave 100% protection against experimentally induced IBK and M. bovis isolates cultured from the eyes 6 days post-challenge were identified as belonging solely to serogroup C. Unexpectedly, only 25% protection was achieved against homologous strain challenge of calves that received the monovalent serogroup B vaccine. Furthermore, the majority of M. bovis isolates recovered from calves in this group belonged to serogroup C, as did half of those isolates cultured from the multivalent vaccinates. The remaining bacterial isolates from the latter group, together with all isolates from the non-vaccinated controls, belonged to serogroup B. Results are consistent with the hypothesis that derivatives of the serogroup B challenge inoculum had expressed serogroup C pilus antigen within 6 days of the challenge, possibly as a result of pilus gene inversion occurring in response to the presence of specific antibody in eye tissues and tears.

Animals↗

PubMed1986

Infectious bovine keratoconjunctivitis: comparison of infection, signs of disease and weight gain in vaccinated versus nonvaccinated purebred Hereford heifer calves.

To determine whether the carrier state of Moraxella bovis could be prevented under natural conditions of exposure by vaccination, purebred Hereford calves were vaccinated twice; once in June 1982, and again in September 1982. Eyes of calves were examined for signs of infectious bovine keratoconjunctivitis (IBK) and cultured for M. bovis in June 1982, September 1982, January 1983 and June 1983. When calves were compared on the basis of selection lines (four genetic groups), there were significant (P less than 0.05) differences in the percentages of infection, disease and weight gain between selection line calves, regardless of their vaccination status. Results suggest that vaccination, in conjunction with clinical infectious, bovine keratoconjunctivitis, reduces the carrier state of M. bovis in the herd but the immunity lasted less than 9 months. The disproportionate representation of the most genetically resistant calves among nonvaccinated calves probably accounted for the equivocal results between vaccinated and nonvaccinated calves.

Animals↗

PubMed1989

Infectious bovine keratoconjunctivitis epizootic associated with area-wide emergence of a new Moraxella bovis pilus type.

Pilus-mediated adherence is a virulence attribute of Moraxella bovis. Several pilus types have been shown to exist among strains of this bacterium, but correlation between pilus type and specific field cases of the disease has not been done. During the summer of 1987, an epizootic of infectious bovine keratoconjunctivitis was reported in 7 Iowa counties. Eight isolates of M bovis were secured from 12 episodes studied. All 8 of the isolates were nearly homogeneous in biochemical properties and had the same plasmid biotype. Pilus typing performed by immunofluorescence and immunogold electron microscopy identified a single new pilus type among 5 of the 8 isolates. This pilus type was identified in field cases that developed within a narrow time frame and over large distances. The implication of these findings is that infectious bovine keratoconjunctivitis epizootics may be associated with emergence of a novel pilus type, and that rapid dissemination over wide distances can occur, presumably by transportation of carrier cattle.

Animals↗

PubMed1993

A Moraxella bovis pili vaccine produced by recombinant DNA technology for the prevention of infectious bovine keratoconjunctivitis.

Pili (fimbriae) were prepared from Moraxella bovis strain Dalton 2d (Dal2d) and from a derivative of Pseudomonas aeruginosa K/2PfS that contained a plasmid-borne Dal2d pilin gene and produced pili having serogroup-specific identity to Dal2d. Nine calves were vaccinated with two doses each of 30 micrograms authentic M. bovis Dal2d pili in oil adjuvant and 10 calves were vaccinated with a similar dose of P. aeruginosa-derived Dal2d pili in the same formulation. All 19 calves and 10 non-vaccinated controls were challenged by instillation of 1 x 10(9) virulent M. bovis Dal2d cells into both conjunctival sacs 19 days after the second vaccine dose. The serological response to vaccination and the degree of protection against experimentally induced infectious bovine keratoconjunctivitis (IBK) were assessed. None of the nine calves vaccinated with authentic M. bovis Dal2d pili developed IBK while two of those vaccinated with P. aeruginosa-derived Dal2d pili developed lesions which accounted for a mean group lesion score of 0.3. In contrast, 9 of the 10 non-vaccinated calves developed IBK lesions, the majority of which were progressive, required early treatment and accounted for a mean group lesion score of 1.5. These results demonstrate the potential of a relatively low dose of pili produced by recombinant DNA technology for development of an effective vaccine against IBK.

Animals↗

PubMed1992

The protective efficacy of pili from different strains of Moraxella bovis within the same serogroup against infectious bovine keratoconjunctivitis.

Three groups of ten calves were each immunised with a total of 400 micrograms pili prepared from three separate strains of Moraxella bovis in Alhydrogel-oil adjuvant as two divided, equal doses 21 days apart. Groups 1 and 2 each received a monovalent vaccine made from strain 4L and S276R respectively, which belonged to pili serogroup A. Group 3 received vaccine made from pili of strain Maff1, belonging to serogroup F. A further group of ten calves served as non-vaccinated controls. Calves in groups 1 and 2 had developed serogroup A-specific antibody and those in group 3 developed serogroup F-specific antibody, and some evidence of cross-reacting antibody was also detected when measured by an agglutination test using formalin-killed piliated cells of serogroup A strain 4L. Although antibody titres measured against purified pili by ELISA were highest with homologous serogroup antigens, cross-reactive titres to shared epitopes of M. bovis pili were also detected by this method. Ocular challenge of the 40 calves with virulent M. bovis of serogroup A strain S276R was carried out 14 days after the second vaccine dose. All non-vaccinated calves developed infectious bovine keratoconjunctivitis (IBK). The percentage protection in groups 1 (strain 4L) and 2 (strain S276R) was 60% and 80% respectively (P less than 0.05), with mean lesion scores of 0.7 and 0.3 out of a possible 6.0. The percentage protection of calves in group 3 (strain Maff1) was only 30%, with a mean lesion score of 1.4 compared with 2.2 for non-vaccinated controls. The present findings, together with other evidence indicating that immunity to IBK is serogroup-specific, suggest that inclusion of pili from one representative strain from each of the seven Australian and British serogroups in a polyvalent, subunit vaccine should effectively protect the majority of cattle against IBK caused by most field strains of M. bovis encountered in Australia and the United Kingdom.

Animals↗

PubMed1977

Induced infectious bovine keratoconjunctivitis: vaccination with whole cell bacterins of Moraxella bovis mixed with Freund's incomplete adjuvant.

Our studies on vaccination against infectious bovine keratoconjunctivitis were extended to include the use of adjuvant bacterins. Seventeen calves were given 2 doses of killed Moraxella bovis mixed with Freund's incomplete adjuvant; 15 calves were given 2 doses of whole cell bacterin without adjuvant. Four weeks later, all vaccinated and non-vaccinated (control) calves were challenge exposed by the conjunctival administration of virulent M bovis. The incorporation of Freund's incomplete adjuvant did not enhance the immunogenicity of M bovis bacterin for protection of calves against infectious bovine keratoconjunctivitis. Results indicated that the use of Freund's incomplete adjuvant does not compensate for a reduction in the number of doses which are required for protective vaccination of cattle.

Animals↗

PubMed2001

Mycoplasma conjunctivae infection is self-maintained in the Swiss domestic sheep population.

Bacteriological and serological investigations were performed to assess whether the domestic sheep population is a reservoir of Mycoplasma conjunctivae in Switzerland. Among a sample of 69 sheep showing clinical signs of infectious keratoconjunctivitis (IKC) in three Swiss cantons, M. conjunctivae was identified 53 times (76.8%). A commercially prepared indirect ELISA was used to detect M. conjunctivae antibodies in 674 sera of adult sheep. We analysed a stratified random sample of 123 sheep herds from 25 out of the 26 Swiss cantons. At least one positive animal was detected in 89.4% of the herds. In positive herds (n=110), 57.1% of the individual animals tested positive. To assess the importance of sheep's age in the spread of M. conjunctivae, 209 sera of adult sheep and 93 lamb sera among eight sheep herds were analysed using the indirect ELISA. Seroprevalence in 2-6-month-old lambs was 50.5%, indicating that the IKC agent is spread in sheep flocks during raising. Lambs experimentally infected with M. conjunctivae carried the agent for 8 and 23 weeks, respectively, depending on the strain used for challenge. We conclude that the M. conjunctivae-infection is endemic and self-maintained in the domestic sheep population in Switzerland.

Animals↗

PubMed2003

Characterization of LppS, an adhesin of Mycoplasma conjunctivae.

A serine-rich membrane protein named LppS from Mycoplasma conjunctivae, the aetiological agent of infectious keratoconjunctivitis (IKC) of domestic and wild Caprinae, was characterized. Gene cloning and sequence analysis of the lppS gene revealed that it encoded a membrane protein precursor. The protein had a typical signal sequence and a signal peptidase II cleavage site followed by a cysteine residue representing a potential acylation site. The mature LppS protein had an apparent molecular mass of 150 kDa and was found in the detergent-associated fraction of Tween 20 extracted M. conjunctivae proteins. It possessed a serine-rich domain of 41 aa with 37 (90.2 %) serine residues. Twenty-seven of these serine residues were contiguous. The protein adhered to lamb joint synovial cells. Using an in vitro adhesion model, Fab fragments from IgG directed against recombinant purified LppS were shown to specifically inhibit adhesion of M. conjunctivae to lamb cells. Thus, LppS is likely to be an adhesin of M. conjunctivae that may play an important role in the pathogenesis of IKC.

Adhesins, Bacterial↗

PubMed2003

Molecular epidemiology of Mycoplasma conjunctivae in Caprinae: transmission across species in natural outbreaks.

Mycoplasma conjunctivae is the etiological agent of infectious keratoconjunctivitis, a highly contagious ocular infection that affects both domestic and wild Caprinae species in the European Alps. In order to study the transmission and spread of M. conjunctivae across domestic and wild Caprinae populations, we developed a molecular method for subtyping and identifying strains of M. conjunctivae. This method is based on DNA sequence determination of a variable domain within the gene lppS, a gene that encodes an antigenic lipoprotein of M. conjunctivae. This domain of lppS shows variations among different strains but remains constant upon generations of individual strains on growth medium and thus allows identification of individual strains and estimation of their phylogenetic intercorrelations. The variable domain of lppS is amplified by PCR using primers that match conserved sequences of lppS flanking it. Sequence analysis of the amplified fragment enables fine subtyping of M. conjunctivae strains. The method is applicable both to isolated strains and to clinical samples directly without requiring the cultivation of the strain. Using this method, we show that M. conjunctivae was transmitted between domestic and wild animals that were grazing in proximate pastures. Certain animals also presented infections with two different strains simultaneously.

Adhesins, Bacterial↗

PubMed2000

Immune responses to Mycoplasma conjunctivae in alpine ibex, alpine chamois, and domestic sheep in Switzerland.

The humoral immune response of three alpine chamois (Rupicapra rupicapra rupicapra), two alpine ibex (Capra ibex ibex) and three domestic sheep naturally affected with infectious keratoconjunctivitis (IKC), and four ibex and two sheep experimentally infected with Mycoplasma conjunctivae was analysed. In addition, the local immune response to M. conjunctivae was analysed using conjunctival washes from chamois and sheep. Immunoblot analysis of sera using whole cell antigens of M. conjunctivae revealed the major immunogenic proteins which had molecular masses of 175, 83, 68, 60, 50, 42, 36, and 33 kDa. Major antigens were found at 83, 68, 60, and 42 kDa in both sera and conjunctival washes from naturally infected animals of all three Caprinae species. In experimentally infected animals, antibodies to the 68 and 60 kDa antigens were dominant. Naturally infected animals showed much stronger immune reactions than those experimentally infected, and specific antibodies appeared 2 to 4 wk after experimental infection. To evaluate possible cross-reactions, whole cell antigen of M. conjunctivae was analysed by immunoblot against hyperimmune sera of closely related Mycoplasma spp. Antibodies to the 175, 73, 68, 60, and 33 kDa antigens appeared to be specific to M. conjunctivae. Cross-reactions mainly with 83, 50, and 42 kDa antigens were detected, in particular with M. ovipneumoniae and M. bovoculi hyperimmune sera, but also with antisera against M. capricolum capricolum and M. putrefaciens.

Animals↗

PubMed2000

Bacteria and nematodes in the conjunctiva of mule deer from Wyoming and Utah.

Swabs of conjunctiva were collected from 44 live and 226 hunter-harvested mule deer (Odocoileus hemionus) from Wyoming and Utah (USA). We identified 29 gram negative and 22 gram positive bacterial taxonomic categories, but many isolates from hunter-harvested animals were environmental contaminants. Staphylococcus spp. and Micrococcus spp. were the most common gram positive bacteria isolated, and Enterobacter spp., Escherichia coli, and Pseudomonas spp. were common gram negative bacteria isolated. Thelazia californiensis were found in 15% of hunter-harvested deer in Utah in 1994 and in 8% in 1995. Nematodes were found in 40% of live deer in 1995 and 66% in 1996. Three live animals showed clinical signs of infectious keratoconjunctivitis (IKC) in 1996, but pathogenic bacteria were not isolated from these individuals. Hemolytic, non-piliated Moraxella ovis was isolated from two clinically normal live deer in 1996 and isolates were similar to those cultured from IKC cases from Wyoming and Utah.

Animals↗

PubMed1988

[Species-forming involution of pathogenic bacteria as a biological pattern (exemplified by bacteria of the genus Moraxella)].

The author advances a hypothesis stating that a species disappearing as a result of new conditions evolving in a colonized animal or human body, unfavorable for the existence of this species, does not become extinct, but reverts into newly developing species due to the loss of its properties and acquiring new properties corresponding to new conditions. Thus the genus is preserved through the loss of species characteristics by individual organisms. The advanced hypothesis is substantiated by the analysis of the relevant processes observed in cases of infectious keratoconjunctivitis in humans and cattle, caused by bacteria of the genus Moraxella. The data indicating the possibility of such reversion in the genera Neisseria and Bordetella are presented.

Animals↗

PubMed1984

Serotypes and antibiotic sensitivity of Moraxella bovis isolated from an outbreak of infectious bovine keratoconjunctivitis.

Samples of conjunctival fluid of four calves, from a herd with infectious bovine keratoconjunctivitis, were collected five times at monthly intervals and from another 16 calves in the initial stages of the disease, were collected only once. Moraxella bovis was recovered from 82.3% of the samples. Twenty-six isolates were typed with polyvalent sera and 25 with monovalent sera. The antibiotic sensitivity of 13 isolates was also studied. Twenty of the 26 isolates reacted with polyvalent sera and 16 of 25 tested isolates, reacted with monovalent sera. The isolates recovered from the same animal in a different collection or from a different animal in the same collection did not always belong to the same serogroup. Different serotypes were prevalent in each collection. Differences in the antibiotic sensitivity of the isolates were also detected.

Animals↗

PubMed1982

The role of face flies in an episode of infectious bovine keratoconjunctivitis.

Cattle partially protected from face flies (Musca autumnalis) had much less infectious bovine keratoconjunctivitis and yielded fewer isolated of hemolytic Moraxella bovis than did similar cattle that received no face fly protection. The number of new isolated of M bovis from the unprotected cattle was highly correlated with the number of face files observed on the cattle. Close physical proximity to cattle infected with M bovis was important in the spread of the bacteria to previously uninfected cattle; however, it did not require physical contact among the cattle to spread from herd to herd. Moraxella bovis first began to spread from herd to herd after face fly populations exceeded 10/animal for 1 month. Keratoconjunctivitis was not observed in 53% of the cattle from which M bovis was isolated. Moraxella bovis was isolated from 4 of 45 pools of face files collected from animals in the untreated herds.

Animals↗

PubMed2004

[Infectious bovine keratoconjunctivitis (IBK) in cows, clinical and lab review at four farms].

After several reports to the GD (Dutch Animal Health Service) from practitioners in The Netherlands concerning serious Infectious Bovine Keratoconjunctivitis (IBK) in dairy herds during summer and autumn 2003, the GD has carried out a pilot-study to determine the most responsible agent. This pilot was thought to be important because of the painfulness of the illness and problems like, (for the farmer) an intensive and difficult therapy. Also the report of a Chlamydophilae infection causing IBK in a dairy herd in the UK prompted to this study. The most frequently isolated infectious agent in our study was Moraxella, probably M. bovis. For the presence of Chlamydophila, mycoplasmata or BHV1 viruses were no indications.

Animals↗

PubMed1982

Infectious bovine keratoconjunctivitis in cattle vaccinated and medicated against Moraxella bovis before parturition.

A vaccination and prophylactic treatment study for infectious bovine keratoconjunctivitis (IBK) was conducted on selection line purebred Hereford and recombination mixed-breed cattle. In February, prepartum cows were allotted to 4 groups: group 1--mixed-breed cows vaccinated with a formalin-killed trivalent Moraxella bovis bacterin; group 2--Hereford cows vaccinated and treated with tylosin; group 3--Hereford cows treated with tylosin; and group 4--mixed-breed cows neither vaccinated nor treated (controls). Groups 2 and 3 were pastured together greater than 3 km for other cattle; cattle added to groups 2 and 3 were treated before being added. Groups 1 and 4 cattle were pastured together; cattle added to groups 1 and 4 were not treated. Cows, and subsequently their calves, were observed cursorily for clinical signs of IBK during the spring and early summer. The eyes of calves were examined in September and October 1979, and their eye secretions were examined for M bovis. The first clinical signs of IBK were seen in the herds in late July, and the largest percentages of acute disease were seen in mid-August. There were no significant differences (P = 0.18) in the percentages of calves that developed IBK, regardless of whether (or not) their dams were vaccinated. A larger percentage of the calves from tylosin-treated cows developed IBK than did calves from nontreated cows. The smallest percentage of disease was seen in calves of cows that were vaccinated only, but the differences were not significant (P greater than 0.10). The percentages of isolations of M bovis were similar (P = 0.23) among the 4 groups of calves. When compared on the basis of breed, the percentage of Hereford calves (62%) that developed IBK was greater than that of the mixed-breed calves (47%). When compared on the basis of color pattern, the percentages with IBK were significantly different (P less than 0.001). The percentages of IBK in calves were: red white-face (70%), black white-face (52%), black black-face with some white on body (40%), black (34%), and others (all color patterns not conforming to the 4 other groups; 21%). When compared on the basis of sire, the percentages of IBK in Hereford calves were significantly different (P less than 0.05). The percentages of affected calves ranged from 80% to 31%; the percentages of affected eyes ranged from 67% to 22%. When compared on the basis of sire, the percentages of IBK in mixed-breed calves were significantly different from each other (P less than 0.001). The percentages of affected calves ranged from 63% to 27% and the percentages of affected eyes ranged from 49% to 16%.

Animals↗