A multiplex real-time PCR assay for the detection and differentiation of five bovine pinkeye pathogens

Zheng, Wanglong; Porter, Elizabeth; Noll, Lance; Stoy, Colin; Lu, Nanyan; Wang, Yin; Liu, Xuming; Purvis, Tanya; Peddireddi, Lalitha; Lubbers, Brian V.; Hanzlicek, Gregg; Henningson, Jamie; Liu, Zongping; Bai, Jianfa

doi:10.1016/j.mimet.2019.03.024

Cited by 25 publications

(18 citation statements)

References 24 publications

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“…and Moraxella spp. to be the major pathogens that predispose cattle to IBK [ 1 , 8 , 9 ]. The mean abundance of these taxa in the current dataset is shown in Figure S5 .…”

Section: Resultsmentioning

confidence: 99%

“…Although many factors contribute to an IBK infection, Moraxella bovis is typically the principal etiologic agent of IBK [ 7 ]. Other agents such as Moraxella bovoculi and Mycoplasma bovoculi have also been associated with IBK outbreaks and their presence may predispose the animal to disease [ 1 , 8 , 9 ]. It is suggested that Moraxella and Mycoplasma enter the eye via face flies or as an effect of secretion after irritation of the eye due to cuts from tall grass, feed, or UV light damage from the sun [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

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Longitudinal assessment of the bovine ocular bacterial community dynamics in calves

et al. 2021

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Background Infectious Bovine Keratoconjunctivitis (IBK), commonly known as pinkeye, is one of the most significant diseases of beef cattle. As such, IBK costs the US beef industry at least 150 million annually. However, strategies to prevent IBK are limited, with most cases resulting in treatment with antibiotics once the disease has developed. Longitudinal studies evaluating establishment of the ocular microbiota may identify critical risk periods for IBK outbreaks or changes in the microbiota that may predispose animals to IBK. Results In an attempt to characterize the establishment and colonization patterns of the bovine ocular microbiota, we conducted a longitudinal study consisting of 227 calves and evaluated the microbiota composition over time using amplicon sequence variants (ASVs) based on 16S rRNA sequencing data and culture-based approaches. Beef calves on trial consisted of both male (intact) and females. Breeds were composed of purebred Angus and composites with varying percentages of Simmental, Angus, and Red Angus breeds. Average age at the start of the trial was 65 days ±15.02 and all calves remained nursing on their dam until weaning (day 139 of the study). The trial consisted of 139 days with four sampling time points on day 0, 21, 41, and 139. The experimental population received three different vaccination treatments (autogenous, commercial (both inactivated bacteria), and adjuvant placebo), to assess the effectiveness of different vaccines for IBK prevention. A significant change in bacterial community composition was observed across time periods sampled compared to the baseline (p < 0.001). However, no treatment effect of vaccine was detected within the ocular bacterial community. The bacterial community composition with the greatest time span between sampling time periods (98d span) was most similar to the baseline sample collected, suggesting re-establishment of the ocular microbiota to baseline levels over time after perturbation. The effect of IgA levels on the microbial community was investigated in a subset of cattle within the study. However, no significant effect of IgA was observed. Significant changes in the ocular microbiota were identified when comparing communities pre- and post-clinical signs of IBK. Additionally, dynamic changes in opportunistic pathogens Moraxella spp. were observed and confirmed using culture based methods. Conclusions Our results indicate that the bovine ocular microbiota is well represented by opportunistic pathogens such as Moraxella and Mycoplasma. Furthermore, this study characterizes the diversity of the ocular microbiota in calves and demonstrates the plasticity of the ocular microbiota to change. Additionally, we demonstrate the ocular microbiome in calves is similar between the eyes and the perturbation of one eye results in similar changes in the other eye. We also demonstrate the bovine ocular microbiota is slow to recover post perturbation and as a result provide opportunistic pathogens a chance to establish within the eye leading to IBK and other diseases. Characterizing the dynamic nature of the ocular microbiota provides novel opportunities to develop potential probiotic intervention to reduce IBK outbreaks in cattle.

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“…and Moraxella spp. to be the major pathogens that predispose cattle to IBK [ 1 , 8 , 9 ]. The mean abundance of these taxa in the current dataset is shown in Figure S5 .…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Longitudinal assessment of the bovine ocular bacterial community dynamics in calves

et al. 2021

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“…The most notable and frequently isolated of these associated bacteria is Moraxella bovoculi (Angelos et al, 2007b). While M. bovoculi has been unsuccessful at inducing IBK experimentally (Gould et al, 2013), it is more frequently isolated from IBK lesions when compared to M. bovis, using both aerobic culture and molecular detection techniques (Loy and Brodersen, 2014;Zheng et al, 2019). Despite the lack of proven causation for M. bovoculi in IBK to date, in 2017 the USDA approved the first conditionally licensed M. bovoculi based vaccine product to be marketed for the prevention of IBK (USDA CVM code: 2A77.00, Addison Biological Laboratory).…”

Section: Introductionmentioning

confidence: 99%

MALDI-TOF MS Biomarker Detection Models to Distinguish RTX Toxin Phenotypes of Moraxella bovoculi Strains Are Enhanced Using Calcium Chloride Supplemented Agar

Hille

Clawson

Dickey

et al. 2021

Front. Cell. Infect. Microbiol.

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Moraxella bovoculi is the bacterium most often cultured from ocular lesions of cattle with infectious bovine keratoconjunctivitis, also known as bovine pinkeye. Some strains of M. bovoculi contain operons encoding for a repeats-in-toxin (RTX) toxin, which is a known virulence factor of multiple veterinary pathogens. We explored the utility of MALDI-TOF MS and biomarker detection models to classify the presence or absence of an RTX phenotype in M. bovoculi. Ninety strains that had undergone whole genome sequencing were classified by the presence or absence of complete RTX operons and confirmed with a visual assessment of hemolysis on blood agar. Strains were grown on Tryptic Soy Agar (TSA) with 5% sheep blood, TSA with 5% bovine blood that was supplemented with 10% fetal bovine serum, 10 mmol/LCaCl2, or both. The formulations were designed to determine the influence of growth media on toxin production or activity, as calcium ions are required for toxin secretion and activity. Mass spectra were obtained for strains grown on each agar formulation and biomarker models were developed using ClinProTools 3.0 software. The most accurate model was developed using spectra from strains grown on TSA with 5% bovine blood and supplemented with CaCl2, which had a sensitivity and specificity of 93.3% and 73.3%, respectively, regarding RTX phenotype classification. The same biomarker model algorithm developed from strains grown on TSA with 5% sheep blood had a substantially lower sensitivity and specificity of 68.0% and 52.0%, respectively. Our results indicate that MALDI-TOF MS biomarker models can accurately classify strains of M. bovoculi regarding the presence or absence of RTX toxin operons and that agar media modifications improve the accuracy of these models.

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“…There are several pathogens were incriminated as etiologic agent responsible for IKC. However, Moraxella with and/or without other pathogens was implicated as a major pathogen causes IKC in small and large ruminants (Abdullah et al, 2015;Gelormini, et al, 2017 andZheng et al, 2019). Moreover, frequent isolation of different microorganisms from ruminants with signs of IKC may attributed to the synergistic action between environmental risk factors and opportunistic pathogens habitat eye (Sağlam etal., 2018).…”

Section: Introductionmentioning

confidence: 99%

Clinical study on Moraxella-associated infectious keratoconjunctivitis (IKC) of small ruminants

Zaitoun

Elseleny

khabaz

2021

Benha Veterinary Medical Journal

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Infectious keratoconjunctivitis (IKC) represents an important health problem in semi-desert and desert areas. The present study tries to investigate the possible role of Moraxella as a causative agent of IKC. A total number of 140 sterile conjunctival swabs from the diseased animals (93 sheep and 47 goats) of different ages showed signs of IKC were subsequently collected, bacteriologically examined to isolate Moraxella spp, which was successively isolated from 19 animals (11 sheep and 8 goats) with infection rate about 13.6%. In relation to age, a higher infection rate (19.2%) was recorded among sheep in the age group ≥ 12 to < 24 months and among goats in the age group ≥ 3 to < 6 months. Antimicrobial sensitivity test of obtained isolates revealed that Moraxella was 100% sensitive to Ciprofloxacin, Gentamicin, and Tylosin, and 79% to Oxytetracycline. All tested isolates were resistant to Vancomycin, Ampicillin plus Sulbactam, and Sulfamethoxazole plus Trimethoprim. Therapeutically, two therapeutic regimens were carried out to treat the diseased cases under field conditions and the results were illustrated in detail. Infectious keratoconjunctivitis Moraxella small ruminantsAntimicrobial sensitivity test and field therapeutic trials

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A multiplex real-time PCR assay for the detection and differentiation of five bovine pinkeye pathogens

Cited by 25 publications

References 24 publications

Longitudinal assessment of the bovine ocular bacterial community dynamics in calves

Longitudinal assessment of the bovine ocular bacterial community dynamics in calves

MALDI-TOF MS Biomarker Detection Models to Distinguish RTX Toxin Phenotypes of Moraxella bovoculi Strains Are Enhanced Using Calcium Chloride Supplemented Agar

Clinical study on Moraxella-associated infectious keratoconjunctivitis (IKC) of small ruminants

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