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Journal of Applied Microbiology Feb 2019This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme...
AIMS
This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme activity against the isolates of M. bovis, M. ovis and M. bovoculi in free form and in biofilms was determined.
METHODS AND RESULTS
In this study, 54 isolates of Moraxella sp. obtained from bovine and ovine clinical samples were evaluated in vitro for capacity of biofilm formation and lysozyme susceptibility in planktonic and sessile cells. In addition, biofilms produced by four Moraxella sp. isolates were visualized under scanning electron microscope (SEM). It was possible to demonstrate, for the first time, the ability to form biofilms by M. ovis and M. bovoculi. The isolates of Moraxella sp. have the capacity to form biofilms in different intensities, varying among weak, moderate and strong. It was verified that the lysozyme shows activity on Moraxella sp. in planktonic form. However, on biofilms there was a reduction in the production, but without impairing its formation, and on consolidated biofilms the lysozyme did not have the capacity to eradicate the preformed biofilms.
CONCLUSIONS
This work shows the capacity of biofilm formation by Moraxella sp. of veterinary importance. The lysozyme susceptibility of Moraxella sp. in planktonic form shows that this enzyme has bacteriostatic activity on this micro-organism and it reduced the production of biofilms.
SIGNIFICANCE AND IMPACT OF THE STUDY
Based on the results, it is possible to infer that the biofilm formation capacity by Moraxella sp. and the resistance to lysozyme concentrations equal to or greater than the physiological levels of the ruminant tear may be linked not only to the capacity to colonize the conjunctiva, but also to remain in this place even after healing of the lesions, being a reservoir of Moraxella sp. in a herd.
Topics: Animals; Biofilms; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Moraxella bovis; Moraxellaceae Infections; Muramidase; Sheep
PubMed: 30142702
DOI: 10.1111/jam.14086 -
Frontiers in Microbiology 2022() is regarded as a causative agent of infectious bovine keratoconjunctivitis (IBK), the most common ocular disease of cattle. Recently, whole genome sequencing...
() is regarded as a causative agent of infectious bovine keratoconjunctivitis (IBK), the most common ocular disease of cattle. Recently, whole genome sequencing identified the presence of two distinct genotypes within that differ in chromosome content, potential virulence factors, as well as prophage and plasmid profiles. It is unclear if the genotypes equally associate with IBK or if one is more likely to be isolated from IBK lesions. We utilized 39 strains of that had previously undergone whole genome sequencing and genotype classification to determine the utility of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) to accurately genotype strains. We successfully developed two biomarker models that accurately classified strains according to genotype with an overall accuracy of 85.8-100% depending upon the model and sample preparation method used. These models provide a practical tool to enable studies of genotype associations with disease, allow for epidemiological studies at the sub-species level, and can be used to enhance disease prevention strategies.
PubMed: 36569069
DOI: 10.3389/fmicb.2022.1057621 -
Microorganisms Jun 2019is an ocular bacterial pathogen isolated in cases of keratitis, conjunctivitis, and endophthalmitis. Gram-negative brick-shaped diplobacilli from ocular specimens, and...
is an ocular bacterial pathogen isolated in cases of keratitis, conjunctivitis, and endophthalmitis. Gram-negative brick-shaped diplobacilli from ocular specimens, and slow growth in culture, are early indications of ocular infection; however, identifying to species can be complex and inconsistent. In this study, bacteria consistent with were identified to species using: (1) DNA sequencing coupled with vancomycin susceptibility, (2) MALDI-TOF mass spectrometry, and (3) the Biolog ID system. Study samples consisted of nine ATCC controls, 82 isolates from keratitis, 21 isolates from conjunctivitis, and 4 isolates from endophthalmitis. The ATCC controls were correctly identified. For keratitis, 66 (80.5%) were identified as , 7 (9.0%) as , 5 (6%) as , 2 (2.5%) as , 1 (1.0%) as , and 1 (1.0%) as . For conjunctivitis, 9 (43.0%) were identified as , 6 (29.0%) as , 3 (14.3%) as , 2 (9.5%) as (), and 1 (4.5%) as . From endophthalmitis, 3 of 4 of the isolates were . Overall, . and were identified in 70% (75 of 107) and 13% (14 of 107) of cases, respectively, totaling 83% (89 of 107). and are important bacterial pathogens of the eye as determined by DNA sequencing, MALDI-TOF MS, and Biolog. Although is a clinical pathogen, other species of appear to have a prominent role in eye infections.
PubMed: 31167433
DOI: 10.3390/microorganisms7060163 -
Genetics and Molecular Biology 2020The objective of this study was to evaluate the genetic diversity of Moraxella bovis and Moraxella bovoculi bacteria isolated from infectious bovine keratoconjunctivitis...
The objective of this study was to evaluate the genetic diversity of Moraxella bovis and Moraxella bovoculi bacteria isolated from infectious bovine keratoconjunctivitis (IBK) outbreaks in the state of Rio Grande do Sul, Brazil. The genetic diversity among Moraxella spp. was evaluated by RAPD-PCR, JWP1-JWOPA07-PCR, ERIC-PCR and by sequencing the 16S-23S intergenic regions. Based on the dendrogram, two genetically differentiated clades were observed; 14 isolates were classified as M. bovis and 17 as M. bovoculi. Genetic distances between the M. bovis samples ranged from 0.0379 to 0.4285, while for M. bovoculi the dissimilarities ranged from zero to 0.7297. Alternatively, based on sequencing analyses of the 16S-23S intergenic region, M. bovis and M. bovoculi isolates were grouped into the same two different clades, but it was not possible to differentiate between isolates within clades. PCR techniques were demonstrated to be a satisfactory tool to unravel the genetic variability among Moraxella spp., while sequencing of the 16S-23S intergenic region was only able to differentiate two species of the Moraxella genus. Despite sampling geographically close regions, we demonstrate considerable genetic diversity in M. bovis and M. bovoculi strains and genetically distinct M. bovis strains co-infecting the same animal.
PubMed: 32478794
DOI: 10.1590/1678-4685-GMB-2018-0380 -
Revista Argentina de Microbiologia Feb 2024Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that affects bovines and has significant economic and health effects worldwide. Gram negative bacteria...
Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that affects bovines and has significant economic and health effects worldwide. Gram negative bacteria Moraxella bovis and Moraxella bovoculi are its main etiological agents. Antimicrobial therapy against IBK is often difficult in beef and dairy herds and, although vaccines are commercially available, their efficacy is variable and dependent on local strains. The aim of this study was to analyze for the first time the genomes of Uruguayan clinical isolates of M. bovis and M. bovoculi. The genomes were de novo assembled and annotated; the genetic basis of fimbrial synthesis was analyzed and virulence factors were identified. A 94% coverage in the reference genomes of both species, and more than 80% similarity to the reference genomes were observed. The mechanism of fimbrial phase variation in M. bovis was detected, and the tfpQ orientation of these genes confirmed, in an inversion region of approximately 2.18kb. No phase variation was determined in the fimbrial gene of M. bovoculi. When virulence factors were compared between strains, it was observed that fimbrial genes have 36.2% sequence similarity. In contrast, the TonB-dependent lactoferrin/transferrin receptor exhibited the highest percentage of amino acid similarity (97.7%) between strains, followed by cytotoxins MbxA/MbvA and the ferric uptake regulator. The role of these virulence factors in the pathogenesis of IBK and their potential as vaccine components should be explored.
PubMed: 38403533
DOI: 10.1016/j.ram.2023.12.003 -
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 -
Journal of the Association of Medical... Jun 2022We report a rare case of bacteremia and polyarticular septic arthritis in a 37-year-old pregnant woman with HIV who injects drugs. Two sets of blood cultures obtained 5...
CASE PRESENTATION
We report a rare case of bacteremia and polyarticular septic arthritis in a 37-year-old pregnant woman with HIV who injects drugs. Two sets of blood cultures obtained 5 hours apart were positive for gram-negative bacilli, and purulent fluid was present intra-operatively from both her left knee and her right third MCP joints.
DIAGNOSIS
Organism identification using ligation sequencing confirmed both her blood culture and synovial tissue isolates as . Her infection was initially treated with third-generation cephalosporins and later changed to moxifloxacin because of a drug reaction; although she defervesced clinically with improvement in her C-reactive protein levels, she died most likely as a result of a non-traumatic fat embolism after an elective cesarean delivery.
DISCUSSION
In contrast to , other species are rarely associated with disease in human hosts. is classically associated with infectious bovine keratoconjunctivitis in cattle; interestingly, our patient denied significant animal exposure. To the authors' knowledge, this is the first case describing infection secondary to in an adult host.
PubMed: 36337353
DOI: 10.3138/jammi-2021-0027