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BMC Microbiology Oct 2022Moraxella bovis and Moraxella bovoculi both associate with infectious bovine keratoconjunctivitis (IBK), an economically significant and painful ocular disease that...
BACKGROUND
Moraxella bovis and Moraxella bovoculi both associate with infectious bovine keratoconjunctivitis (IBK), an economically significant and painful ocular disease that affects cattle worldwide. There are two genotypes of M. bovoculi (genotypes 1 and 2) that differ in their gene content and potential virulence factors, although neither have been experimentally shown to cause IBK. M. bovis is a causative IBK agent, however, not all strains carry a complete assortment of known virulence factors. The goals of this study were to determine the population structure and depth of M. bovis genomic diversity, and to compare core and accessory genes and predicted outer membrane protein profiles both within and between M. bovis and M. bovoculi.
RESULTS
Phylogenetic trees and bioinformatic analyses of 36 M. bovis chromosomes sequenced in this study and additional available chromosomes of M. bovis and both genotype 1 and 2 M. bovoculi, showed there are two genotypes (1 and 2) of M. bovis. The two M. bovis genotypes share a core of 2015 genes, with 121 and 186 genes specific to genotype 1 and 2, respectively. The two genotypes differ by their chromosome size and prophage content, encoded protein variants of the virulence factor hemolysin, and by their affiliation with different plasmids. Eight plasmid types were identified in this study, with types 1 and 6 observed in 88 and 56% of genotype 2 strains, respectively, and absent from genotype 1 strains. Only type 1 plasmids contained one or two gene copies encoding filamentous haemagglutinin-like proteins potentially involved with adhesion. A core of 1403 genes was shared between the genotype 1 and 2 strains of both M. bovis and M. bovoculi, which encoded a total of nine predicted outer membrane proteins.
CONCLUSIONS
There are two genotypes of M. bovis that differ in both chromosome content and plasmid profiles and thus may not equally associate with IBK. Immunological reagents specifically targeting select genotypes of M. bovis, or all genotypes of M. bovis and M. bovoculi together could be designed from the outer membrane proteins identified in this study.
Topics: Cattle; Animals; Moraxella bovis; Keratoconjunctivitis, Infectious; Phylogeny; Hemolysin Proteins; Hemagglutinins; Cattle Diseases; Moraxellaceae Infections; Genotype; Whole Genome Sequencing; Virulence Factors
PubMed: 36271336
DOI: 10.1186/s12866-022-02670-3 -
Veterinary and Animal Science Jun 2020Infectious bovine keratoconjunctivitis (IBK) is a widespread, contagious ocular disease that affects cattle, especially dairy breeds. The disease is caused by...
Infectious bovine keratoconjunctivitis (IBK) is a widespread, contagious ocular disease that affects cattle, especially dairy breeds. The disease is caused by Gram-negative bacteria mainly and its treatment consists of parenteral or topic antibiotic therapy. The topic treatment approach is used more commonly in lactating cows, to avoid milk disposal. However, treatment failures are common, because the antibiotic is removed during lacrimation. This study aimed to evaluate the susceptibility of commercial cloxacillin and evaluate the efficacy of nanostructured cloxacillin in clinical cases of IBK by . The minimum inhibitory concentration (MIC) of nanoparticle cloxacillin nanocoated, the nanoparticle without the antibiotic and the commercial cloxacillin were determined with field samples of (5) and (5). The efficiency of nanoparticles was tested in three cows naturally infected that were treated with 1.0 mL (with 0.32 mg of nanostructured cloxacillin) for the ocular route. was isolated and identified by biochemical and molecular methods before the treatment. The animals were treated every 12 h for six days. The cure was considered by the absence of clinical symptoms and bacteria after treatment. The mucoadhesive nanoparticle-based formulation promoted clinical cure with a low number of doses of antibiotics, probably due to the maintenance of the MIC in the ocular mucosa for longer due to the mucoadhesive characteristics of the nanoparticle. The results indicate that the use of nanocoated cloxacillin is possible to control infectious bovine keratoconjunctivitis.
PubMed: 32734103
DOI: 10.1016/j.vas.2020.100089 -
Animal Microbiome Nov 2023Infectious bovine keratoconjunctivitis (IBK) is a common cause of morbidity in cattle, resulting in significant economic losses. This study aimed to characterize the...
BACKGROUND
Infectious bovine keratoconjunctivitis (IBK) is a common cause of morbidity in cattle, resulting in significant economic losses. This study aimed to characterize the bovine bacterial ocular surface microbiome (OSM) through conjunctival swab samples from Normal eyes and eyes with naturally acquired, active IBK across populations of cattle using a three-part approach, including bacterial culture, relative abundance (RA, 16 S rRNA gene sequencing), and semi-quantitative random forest modeling (real-time polymerase chain reaction (RT-PCR)).
RESULTS
Conjunctival swab samples were obtained from eyes individually classified as Normal (n = 376) or IBK (n = 228) based on clinical signs. Cattle unaffected by IBK and the unaffected eye in cattle with contralateral IBK were used to obtain Normal eye samples. Moraxella bovis was cultured from similar proportions of IBK (7/228, 3.07%) and Normal eyes (1/159, 0.63%) (p = 0.1481). Moraxella bovoculi was cultured more frequently (p < 0.0001) in IBK (59/228, 25.88%) than Normal (7/159, 4.40%) eyes. RA (via 16 S rRNA gene sequencing) of Actinobacteriota was significantly higher in Normal eyes (p = 0.0045). Corynebacterium variabile and Corynebacterium stationis (Actinobacteriota) were detected at significantly higher RA (p = 0.0008, p = 0.0025 respectively) in Normal eyes. Rothia nasimurium (Actinobacteriota) was detected at significantly higher RA in IBK eyes (p < 0.0001). Alpha-diversity index was not significantly different between IBK and Normal eyes (p > 0.05). Alpha-diversity indices for geographic location (p < 0.001), age (p < 0.0001), sex (p < 0.05) and breed (p < 0.01) and beta-diversity indices for geographic location (p < 0.001), disease status (p < 0.01), age (p < 0.001), sex (p < 0.001) and breed (p < 0.001) were significantly different between groups. Modeling of RT-PCR values reliably categorized the microbiome of IBK and Normal eyes; primers for Moraxella bovoculi, Moraxella bovis, and Staphylococcus spp. were consistently the most significant canonical variables in these models.
CONCLUSIONS
The results provide further evidence that multiple elements of the bovine bacterial OSM are altered in the context of IBK, indicating the involvement of a variety of bacteria in addition to Moraxella bovis, including Moraxella bovoculi and R. nasimurium, among others. Actinobacteriota RA is altered in IBK, providing possible opportunities for novel therapeutic interventions. While RT-PCR modeling provided limited further support for the involvement of Moraxella bovis in IBK, this was not overtly reflected in culture or RA results. Results also highlight the influence of geographic location and breed type (dairy or beef) on the bovine bacterial OSM. RT-PCR modeling reliably categorized samples as IBK or Normal.
PubMed: 37996960
DOI: 10.1186/s42523-023-00282-4 -
Brazilian Journal of Microbiology :... Sep 2021Infectious keratoconjunctivitis (IKC) is the most frequent ocular disease in livestock worldwide and is primarily caused by Moraxella bovis, M. ovis, and/or M. bovoculi....
Infectious keratoconjunctivitis (IKC) is the most frequent ocular disease in livestock worldwide and is primarily caused by Moraxella bovis, M. ovis, and/or M. bovoculi. The economic impact of IKC is mainly due to ocular damage, which leads to weight loss, management difficulties, pain and discomfort, and cost of treatments. In horses, limited information is available on the association of Moraxella spp. with keratoconjunctivitis. The present report describes two cases of equine keratoconjunctivitis caused by members of the genus Moraxella. Both animals presented with lacrimation, conjunctivitis, photophobia, mucoid or purulent secretions, blepharitis, and conjunctival hyperemia. The diagnosis of IKC was based on the epidemiological and clinical findings; the etiological agent was identified through bacteriological (culture and biochemistry assays) and molecular testing (PCR and nucleotide sequencing). Our study reports the isolation of Moraxella bovoculi (SBP 88/19) and a putative new species/mutant of Moraxella (SBP 39/19) recovered from ocular secretions in horses. Thus, we suggest the inclusion of Moraxella spp. infection in the differential diagnosis of conjunctivitis in horses in Southern Brazil.
Topics: Animals; Brazil; Horses; Keratoconjunctivitis, Infectious; Moraxella; Moraxellaceae Infections
PubMed: 33931826
DOI: 10.1007/s42770-021-00507-1 -
Veterinary World Sep 2023Infectious bovine keratoconjunctivitis (IBK) causes a significant economic loss to cattle industries in many countries, including Kazakhstan. Although is recognized as...
BACKGROUND AND AIM
Infectious bovine keratoconjunctivitis (IBK) causes a significant economic loss to cattle industries in many countries, including Kazakhstan. Although is recognized as an etiologic agent of IBK, other bacterial and viral agents have been suspected to play a role in the pathogenesis of this disease. This study aimed to evaluate samples collected from the eyes of IBK-affected cattle in Eastern Kazakhstan at different stages of IBK for the presence of , , , , and Bovine Herpes Virus Type 1 (BHV-1) and to characterize gene sequence diversity from positive samples.
MATERIALS AND METHODS
Individual ocular swabs (n = 168) were collected from cattle that had clinical signs of IBK during the summer of 2022 on farms in the Abay region of Kazakhstan. Eye lesion scores (1, 2, and 3) were assigned depending on the degree of ocular damage. Infectious bovine keratoconjunctivitis-associated organisms were detected using a multiplex real-time polymerase chain reaction assay. The gene was sequenced from positive samples.
RESULTS
and BHV-1 were not detected in any of the collected samples. was identified in the majority of samples overall, usually in mixed infection with spp. was detected in 76.2% of animals and predominated in animals with eye lesion scores 2 and 3. was detected only in association with and/or in animals with eye lesion scores 2 and 3. was found in 57.7% of animals and was always identified in association with another organism. Sequencing of the gene in 96 samples from positive samples identified five PilA groups. The majority belonged to PilA group A. However, three new PilA groups were identified and designated PilA groups N, O, and P.
CONCLUSION
The results indicate a high prevalence of and in eyes of cattle with IBK on livestock farms in Eastern Kazakhstan. Additional novel PilA groups were identified.
PubMed: 37859972
DOI: 10.14202/vetworld.2023.1833-1839 -
Microbial Pathogenesis May 2023Infectious bovine keratoconjunctivitis (IBK) is the most important eye disease in ruminants worldwide. Moraxella bovis and Moraxella bovoculi can form biofilm and are...
Infectious bovine keratoconjunctivitis (IBK) is the most important eye disease in ruminants worldwide. Moraxella bovis and Moraxella bovoculi can form biofilm and are frequently isolated from affected animals. Antimicrobials are used worldwide to treat clinical cases of IBK, although they have limited success in clearing the infection. Therefore, photodynamic therapy using porphyrins as photosensitizing molecules is an alternative method to eliminate microorganisms, including biofilms. We evaluated the antibacterial activity of a zinc(II) metalloporphyrin (ZnTMeP) against M. bovis and M. bovoculi biofilms since this compound can efficiently inactivate planktonic Moraxella spp. This study was carried out with two reference strains of Moraxella spp. (M. bovis: ATCC® 10900 and M. bovoculli: ATCC® BAA1259). The antibacterial activity of 4.0 μM of the ZnTMeP porphyrin was evaluated on forming and consolidate biofilms with three 30-min cycles of white-light exposure for three days. The ZnTMeP porphyrin reduced M. bovis and M. bovoculi biofilm formation. In addition, ZnTMeP partially destroyed consolidated M. bovoculi biofilms in the second white-light irradiation cycle, although the porphyrin had no effect against the consolidated biofilm of M. bovis. Despite the biofilm still not being completely inactivated, our findings are promising and encourage further experiments using the phototherapy protocol.
Topics: Cattle; Animals; Porphyrins; Keratoconjunctivitis, Infectious; Cattle Diseases; Moraxella; Anti-Bacterial Agents; Moraxellaceae Infections; Biofilms; Photochemotherapy
PubMed: 36948363
DOI: 10.1016/j.micpath.2023.106081 -
The Veterinary Clinics of North... Jul 2021Infectious bovine keratoconjunctivitis (IBK) involves multiple factors and opportunistic pathogens, including members of the genus Moraxella, specifically M bovis. The... (Review)
Review
Infectious bovine keratoconjunctivitis (IBK) involves multiple factors and opportunistic pathogens, including members of the genus Moraxella, specifically M bovis. The causal role of M bovis is clear, where the presence of virulence factors that facilitate colonization (pili) and host cytotoxicity (RTX toxins) are well characterized, and IBK has been reproduced in many models. Experimental infection with M bovoculi has failed to reproduce IBK-typical lesions in cattle thus far. However, recent work using genomics and mass spectrometry have found genomic diversity and recombination within these species, making species differentiation complex and challenging the ability to assign IBK causality to these organisms.
Topics: Animals; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Moraxellaceae Infections
PubMed: 34049659
DOI: 10.1016/j.cvfa.2021.03.004 -
Animal : An International Journal of... Jun 2021Infectious bovine keratoconjunctivitis (IBK) is a common ocular disease in cattle that causes economic losses to producers and negatively impacts animal welfare. In a... (Review)
Review
Infectious bovine keratoconjunctivitis (IBK) is a common ocular disease in cattle that causes economic losses to producers and negatively impacts animal welfare. In a 2016 survey of cow-calf producers in California, IBK was identified as the disease for which antimicrobials are most frequently used. The presented scoping review examined the available literature for methods to prevent IBK and for alternatives to antimicrobials to treat the disease that can be applied in cow-calf operations. Online databases were searched for publications about IBK in cattle populations that were reported from 1950 to 2020. Citations were systematically evaluated in a multi-stage approach using commercial software and summarized in a scoping review format. For the studies included in the review, most research (n = 50) has focused on the development of vaccines for the prevention of IBK. Although the quality of publications has improved over time, there is a lack of consistent evidence for vaccine efficacy against IBK in post-2000 experimental and conventional vaccine trials. A systematic analysis of vaccine studies is warranted. A limited number (n = 6) of studies evaluated the prevention of IBK through fly control, where most have found efficacy of this control measure. Several treatment options (n = 5) that do not include the use of antimicrobials have been investigated but remain at the preliminary stage of testing. Differences in breed susceptibility has been demonstrated with breeds belonging to the Bos indicus subspecies less frequently affected compared to those belonging to the Bos taurus subspecies. Hereford cattle and those lacking pigmentation around the eyelid margin are more frequently affected than other breeds. At present, there are few evidence-based measures that producers can utilize to reduce the burden of IBK in their herds and more research into the efficacy of fly control measures, non-antimicrobial treatment options, the continued search for a viable vaccine, as well as identifying genetic markers associated with traits that confer resistance to the disease are needed.
Topics: Animals; Cattle; Cattle Diseases; Female; Keratoconjunctivitis; Moraxellaceae Infections; Phenotype
PubMed: 34062463
DOI: 10.1016/j.animal.2021.100245 -
World Journal of Microbiology &... May 2022Infectious bovine keratoconjunctivitis (IBK) is an ocular disease affecting bovine herds worldwide, and it causes significant economic loss. The etiologic agent of IBK...
Infectious bovine keratoconjunctivitis (IBK) is an ocular disease affecting bovine herds worldwide, and it causes significant economic loss. The etiologic agent of IBK is considered to be Moraxella bovis, but M. ovis and M. bovoculi are frequently recovered of animals presenting clinical signs of IBK. The therapeutic measures available for its control have limited efficacy. Antimicrobial photodynamic therapy (aPDT) using porphyrins as photosensitizing molecules is an alternative method that can be used to reduce microbial growth. We evaluated the antibacterial activity of aPDT using two water-soluble tetra-cationic porphyrins (HTMeP and ZnTMeP) against 22 clinical isolates and standard strains of Moraxella spp. in vitro and in an ex vivo model. For the in vitro assay, 4.0 µM of porphyrin was incubated with approximately 1.0 × 10 CFU/mL of each Moraxella sp. isolate and exposed to artificial light for 0, 2.5, 5, and 7.5 min. Next, 50 µL of this solution was plated and incubated for 24 h until CFU measurement. For the ex vivo assay, corneas excised from the eyeballs of slaughtered cattle were irrigated with Moraxella spp. culture, followed by the addition of zinc(II) porphyrin ZnTMeP (4.0 μM). The corneal samples were irradiated for 0, 7.5, and 30 min, followed by swab collection, plating, and CFU count. The results demonstrated the in vitro inactivation of the strains and clinical isolates of Moraxella spp. after 2.5 min of irradiation using ZnTMeP, reaching complete inactivation until 7.5 min. In the ex vivo experiment, the use of ZnTMeP resulted in the most significant reduction in bacterial concentration after 30 min of irradiation. These results encourage future in vivo experiments to investigate the role of metalloporphyrin ZnTMeP in the inactivation of Moraxella spp. isolates causing IBK.
Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Cattle; Cattle Diseases; Keratoconjunctivitis; Keratoconjunctivitis, Infectious; Moraxella; Moraxellaceae Infections; Photochemotherapy; Porphyrins; Sheep
PubMed: 35501420
DOI: 10.1007/s11274-022-03291-8 -
Vaccines Jun 2022A randomized control trial was performed over a five-year period to assess the efficacy and antibody response induced by autogenous and commercial vaccine formulations...
A Five Year Randomized Controlled Trial to Assess the Efficacy and Antibody Responses to a Commercial and Autogenous Vaccine for the Prevention of Infectious Bovine Keratoconjunctivitis.
A randomized control trial was performed over a five-year period to assess the efficacy and antibody response induced by autogenous and commercial vaccine formulations against infectious bovine keratoconjunctivitis (IBK). Calves were randomly assigned each year to one of three arms: an autogenous vaccine treatment that included (), , and antigens, a commercial vaccine treatment, or a sham vaccine treatment that consisted only of adjuvant. A total of 1198 calves were enrolled in the study. Calves were administered the respective vaccines approximately 21 days apart, just prior to turnout on summer pastures. Treatment effects were analyzed for IBK incidence, retreatment incidence, 205-day adjusted weaning weights, and antibody response to the type IV pilus protein (pili) of as measured by a novel indirect enzyme-linked immunosorbent screening assay (ELISA). Calves vaccinated with the autogenous formulation experienced a decreased cumulative incidence of IBK over the entire study compared to those vaccinated with the commercial and sham formulations (24.5% vs. 30.06% vs. 30.3%, respectively, = 0.25), and had less IBK cases that required retreatment compared to the commercial and sham formulations (21.4% vs. 27.9% vs. 34.3%, respectively, = 0.15), but these differences were not significant. The autogenous formulation induced a significantly stronger antibody response than the commercial ( = 0.022) and sham formulations ( = 0.001), but antibody levels were not significantly correlated with IBK protection ( = 0.37).
PubMed: 35746524
DOI: 10.3390/vaccines10060916