The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform

Tanja Opriessnig - One of the best experts on this subject based on the ideXlab platform.

  • descriptive epidemiology of Moraxella bovis Moraxella bovoculi and Moraxella ovis in beef calves with naturally occurring infectious bovine keratoconjunctivitis pinkeye
    Veterinary Microbiology, 2012
    Co-Authors: Annette M Oconnor, H G Shen, Chong Wang, Tanja Opriessnig
    Abstract:

    Abstract Problem addressed Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that causes substantial weight loss in beef calves. Objective The objective of this study was to evaluate the association between Moraxella bovoculi , Moraxella bovis and Moraxella ovis and IBK incidence. Methods and approach A cohort design was used. From 239 calves and 478 eyes, 77 randomly chosen eyes were monitored for M. bovoculi , M. bovis , M. ovis and IBK incidence over 4 months. One hypothesis tested was that IBK hazard in eyes was not associated with detection of M. bovoculi , M. bovis and M. ovis . A secondary hypothesis tested that IBK cases were not associated with increased prevalence of M. bovoculi , M. bovis and M. ovis . Results 23% of 77 eyes developed IBK. M. ovis was identified in one IBK-negative eye. The adjusted hazard ratio (HR) for IBK incidence from eyes where M. bovoculi or M. bovis were recovered prior to disease occurrence were not statistically significant ( M. bovoculi HR = 1.38, 95% CI: 0.54–3.53, p  = 0.49, M. bovis HR = 1.60, 95% CI: 0.48–5.53, p  = 0.44). The adjusted hazard ratio for M. bovoculi in IBK lesions was 6.45 (95% CI: 3.35–12.44, p M. bovis in IBK lesions was 2.33 (95% CI: 1.22–4.45, p  = 0.01). Conclusion A temporal association between prior exposure to M. bovoculi or M. bovis and subsequent IBK incidence was not demonstrated. However, M. bovoculi and M. bovis are more frequently recovered from eyes with IBK lesions than unaffected eyes and this provides weak evidence for a causal role.

  • development and evaluation of a multiplex real time pcr assay for the detection and differentiation of Moraxella bovis Moraxella bovoculi and Moraxella ovis in pure culture isolates and lacrimal swabs collected from conventionally raised cattle
    Journal of Applied Microbiology, 2011
    Co-Authors: Huigang Shen, Tanja Opriessnig, Stacie A Gould, Joann M Kinyon, Annette M Oconnor
    Abstract:

    Aim:  To develop a multiplex real-time PCR assay for the detection and differentiation of Moraxella bovis (M. bovis), M. bovoculi and M. ovis. Methods and Results:  The multiplex real-time PCR assay was validated on three reference strains, 57 pure culture isolates and 45 lacrimal swab samples. All reference strains were identified correctly with no cross-reactions between species. Sequencing of 53 of the 57 culture isolates confirmed the results obtained with the multiplex real-time PCR, and the assay had 96·5% (55/57) concordance with a Moraxella spp. multiplex conventional PCR assay on the isolates. Among the lacrimal swab samples, the concordance between the multiplex real-time PCR and culture was 86·7% (39/45) for M. bovoculi and 75·6% (34/45) for M. bovis. Conclusions:  The multiplex real-time PCR assay is specific and sensitive and can be used directly on lacrimal swab samples. Significance and Impact of Study:  The lack of a rapid, specific and sensitive detection method is a barrier for determining the roles of M. bovis, M. bovoculi and M. ovis in infectious bovine keratoconjunctivitis cases, and the developed PCR assay will contribute to improved understanding of the epidemiology and pathogenesis of these three Moraxella species.

  • Descriptive epidemiology of Moraxella bovis, Moraxella bovoculi and Moraxella ovis in beef calves with naturally occurring infectious bovine keratoconjunctivitis (Pinkeye).
    Veterinary microbiology, 2011
    Co-Authors: A M O'connor, H G Shen, Chong Wang, Tanja Opriessnig
    Abstract:

    Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that causes substantial weight loss in beef calves. The objective of this study was to evaluate the association between Moraxella bovoculi, Moraxella bovis and Moraxella ovis and IBK incidence. A cohort design was used. From 239 calves and 478 eyes, 77 randomly chosen eyes were monitored for M. bovoculi, M. bovis, M. ovis and IBK incidence over 4 months. One hypothesis tested was that IBK hazard in eyes was not associated with detection of M. bovoculi, M. bovis and M. ovis. A secondary hypothesis tested that IBK cases were not associated with increased prevalence of M. bovoculi, M. bovis and M. ovis. 23% of 77 eyes developed IBK. M. ovis was identified in one IBK-negative eye. The adjusted hazard ratio (HR) for IBK incidence from eyes where M. bovoculi or M. bovis were recovered prior to disease occurrence were not statistically significant (M. bovoculi HR=1.38, 95% CI: 0.54-3.53, p=0.49, M. bovis HR=1.60, 95% CI: 0.48-5.53, p=0.44). The adjusted hazard ratio for M. bovoculi in IBK lesions was 6.45 (95% CI: 3.35-12.44, p<0.001). The adjusted hazard ratio for M. bovis in IBK lesions was 2.33 (95% CI: 1.22-4.45, p=0.01). A temporal association between prior exposure to M. bovoculi or M. bovis and subsequent IBK incidence was not demonstrated. However, M. bovoculi and M. bovis are more frequently recovered from eyes with IBK lesions than unaffected eyes and this provides weak evidence for a causal role. Copyright © 2011 Elsevier B.V. All rights reserved.

John A. Angelos - One of the best experts on this subject based on the ideXlab platform.

  • Differentiation of Moraxella bovoculi sp. nov. from other coccoid Moraxellae by the use of polymerase chain reaction and restriction endonuclease analysis of amplified DNA.
    Journal of Veterinary Diagnostic Investigation, 2007
    Co-Authors: John A. Angelos, Louise M. Ball
    Abstract:

    Moraxella ovis was historically the only coccoid Moraxella identified in cultures of ocular fluid from cattle with infectious bovine keratoconjunctivitis (IBK) and could be morphologically and biochemically differentiated from Moraxella bovis. Moraxella bovoculi sp. nov. is a recently characterized Moraxella isolated from ulcerated eyes of calves with IBK in northern California in 2002. Like Moraxella ovis, M. bovoculi sp. nov. is a gram-negative coccus/diplococcus. All 18 original isolates of M. bovoculi sp. nov. possessed phenylalanine deaminase (PADase) activity and could therefore be differentiated from M. ovis and M. bovis. During the characterization of 44 additional isolates of hemolytic gram-negative cocci that were cultured from ulcerated eyes of IBK-affected calves, 2 PADase-negative isolates were identified that could not be differentiated biochemically from M. ovis; however, the DNA sequence of the 16S-23S intergenic spacer region (ISR) of the isolates matched the 16S-23S ISR DNA sequence of M. bovoculi sp. nov. To facilitate the identification of PADase-negative Moraxellae, a polymerase chain reaction (PCR) coupled with restriction enzyme digestion analysis of amplified DNA was developed. Amplification of the 16S-23S ISR followed by AfaI digestion of amplified DNA could differentiate M. bovoculi sp. nov. from M. ovis and other Moraxellae. The DNA sequence analysis of the amplified 16S-23S ISR from the 42 PADase-positive isolates of hemolytic gram-negative cocci indicated that all were M. bovoculi sp. nov. and all possessed an AfaI site. A PCR coupled with restriction analysis of amplified DNA can aid in identifying M. bovoculi sp. nov.

  • Identification and characterization of complete RTX operons in Moraxella bovoculi and Moraxella ovis.
    Veterinary microbiology, 2007
    Co-Authors: John A. Angelos, Louise M. Ball, John F Hess
    Abstract:

    To determine if Moraxella bovoculi (M. bovoculi), a recently characterized coccoid Moraxella that was isolated from the eyes of calves affected with infectious bovine keratoconjunctivitis (IBK), and Moraxella ovis (M. ovis), originally isolated from sheep with conjunctivitis, possessed genes encoding RTX proteins, genomic DNA was amplified with oligonucleotide primers targeting RTX operon genes of Moraxella bovis (M. bovis). Complete classical RTX operons composed of RTXCABD genes closely linked to a putative secretion accessory protein encoding gene (tolC) were identified in M. bovoculi and M. ovis and were designated mbvCABDtolC and movCABDtolC, respectively. These genes were closely related to M. bovis mbxCABDtolC. Polyclonal rabbit antiserum against the carboxy terminus of M. bovoculi MbvA neutralized hemolytic activity of both M. bovoculi and M. ovis; this antiserum did not neutralize the hemolytic activity of M. bovis. M. bovoculi and M. ovis possess genes that encode proteins related to pathogenic factors of M. bovis.

  • Moraxella bovoculi sp. nov., isolated from calves with infectious bovine keratoconjunctivitis.
    International journal of systematic and evolutionary microbiology, 2007
    Co-Authors: John A. Angelos, Louise M. Ball, Phillip Q Spinks, L. W. George
    Abstract:

    Eighteen isolates of a Gram-negative coccus (strain 237(T)) were cultured from the eyes of dairy and beef calves affected with infectious bovine keratoconjunctivitis (IBK; 'pinkeye') in northern California, USA, during summer 2002. These isolates had near full-length (1397 bp) 16S rRNA gene sequences that clustered into three groups with 99.9 % sequence similarity. On the basis of 16S rRNA gene sequence, the isolates were most closely associated with Moraxella bovis and Moraxella ovis in clade I of the classical Moraxellae. Biochemically, the novel isolates could be distinguished from the other members of the genus Moraxella isolated from animals on the basis of phenylalanine deaminase activity. The results of partial sequence analysis of six housekeeping genes, the 16S-23S rRNA gene interspacer region and partial 23S rRNA gene provide strong support for the inclusion of these isolates in a novel taxon, for which the name Moraxella bovoculi sp. nov. is proposed. The type strain is strain 237(T) (=ATCC BAA-1259(T)=CCUG 52049(T)).

Louise M. Ball - One of the best experts on this subject based on the ideXlab platform.

  • Differentiation of Moraxella bovoculi sp. nov. from other coccoid Moraxellae by the use of polymerase chain reaction and restriction endonuclease analysis of amplified DNA.
    Journal of Veterinary Diagnostic Investigation, 2007
    Co-Authors: John A. Angelos, Louise M. Ball
    Abstract:

    Moraxella ovis was historically the only coccoid Moraxella identified in cultures of ocular fluid from cattle with infectious bovine keratoconjunctivitis (IBK) and could be morphologically and biochemically differentiated from Moraxella bovis. Moraxella bovoculi sp. nov. is a recently characterized Moraxella isolated from ulcerated eyes of calves with IBK in northern California in 2002. Like Moraxella ovis, M. bovoculi sp. nov. is a gram-negative coccus/diplococcus. All 18 original isolates of M. bovoculi sp. nov. possessed phenylalanine deaminase (PADase) activity and could therefore be differentiated from M. ovis and M. bovis. During the characterization of 44 additional isolates of hemolytic gram-negative cocci that were cultured from ulcerated eyes of IBK-affected calves, 2 PADase-negative isolates were identified that could not be differentiated biochemically from M. ovis; however, the DNA sequence of the 16S-23S intergenic spacer region (ISR) of the isolates matched the 16S-23S ISR DNA sequence of M. bovoculi sp. nov. To facilitate the identification of PADase-negative Moraxellae, a polymerase chain reaction (PCR) coupled with restriction enzyme digestion analysis of amplified DNA was developed. Amplification of the 16S-23S ISR followed by AfaI digestion of amplified DNA could differentiate M. bovoculi sp. nov. from M. ovis and other Moraxellae. The DNA sequence analysis of the amplified 16S-23S ISR from the 42 PADase-positive isolates of hemolytic gram-negative cocci indicated that all were M. bovoculi sp. nov. and all possessed an AfaI site. A PCR coupled with restriction analysis of amplified DNA can aid in identifying M. bovoculi sp. nov.

  • Identification and characterization of complete RTX operons in Moraxella bovoculi and Moraxella ovis.
    Veterinary microbiology, 2007
    Co-Authors: John A. Angelos, Louise M. Ball, John F Hess
    Abstract:

    To determine if Moraxella bovoculi (M. bovoculi), a recently characterized coccoid Moraxella that was isolated from the eyes of calves affected with infectious bovine keratoconjunctivitis (IBK), and Moraxella ovis (M. ovis), originally isolated from sheep with conjunctivitis, possessed genes encoding RTX proteins, genomic DNA was amplified with oligonucleotide primers targeting RTX operon genes of Moraxella bovis (M. bovis). Complete classical RTX operons composed of RTXCABD genes closely linked to a putative secretion accessory protein encoding gene (tolC) were identified in M. bovoculi and M. ovis and were designated mbvCABDtolC and movCABDtolC, respectively. These genes were closely related to M. bovis mbxCABDtolC. Polyclonal rabbit antiserum against the carboxy terminus of M. bovoculi MbvA neutralized hemolytic activity of both M. bovoculi and M. ovis; this antiserum did not neutralize the hemolytic activity of M. bovis. M. bovoculi and M. ovis possess genes that encode proteins related to pathogenic factors of M. bovis.

  • Moraxella bovoculi sp. nov., isolated from calves with infectious bovine keratoconjunctivitis.
    International journal of systematic and evolutionary microbiology, 2007
    Co-Authors: John A. Angelos, Louise M. Ball, Phillip Q Spinks, L. W. George
    Abstract:

    Eighteen isolates of a Gram-negative coccus (strain 237(T)) were cultured from the eyes of dairy and beef calves affected with infectious bovine keratoconjunctivitis (IBK; 'pinkeye') in northern California, USA, during summer 2002. These isolates had near full-length (1397 bp) 16S rRNA gene sequences that clustered into three groups with 99.9 % sequence similarity. On the basis of 16S rRNA gene sequence, the isolates were most closely associated with Moraxella bovis and Moraxella ovis in clade I of the classical Moraxellae. Biochemically, the novel isolates could be distinguished from the other members of the genus Moraxella isolated from animals on the basis of phenylalanine deaminase activity. The results of partial sequence analysis of six housekeeping genes, the 16S-23S rRNA gene interspacer region and partial 23S rRNA gene provide strong support for the inclusion of these isolates in a novel taxon, for which the name Moraxella bovoculi sp. nov. is proposed. The type strain is strain 237(T) (=ATCC BAA-1259(T)=CCUG 52049(T)).

Chong Wang - One of the best experts on this subject based on the ideXlab platform.

  • descriptive epidemiology of Moraxella bovis Moraxella bovoculi and Moraxella ovis in beef calves with naturally occurring infectious bovine keratoconjunctivitis pinkeye
    Veterinary Microbiology, 2012
    Co-Authors: Annette M Oconnor, H G Shen, Chong Wang, Tanja Opriessnig
    Abstract:

    Abstract Problem addressed Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that causes substantial weight loss in beef calves. Objective The objective of this study was to evaluate the association between Moraxella bovoculi , Moraxella bovis and Moraxella ovis and IBK incidence. Methods and approach A cohort design was used. From 239 calves and 478 eyes, 77 randomly chosen eyes were monitored for M. bovoculi , M. bovis , M. ovis and IBK incidence over 4 months. One hypothesis tested was that IBK hazard in eyes was not associated with detection of M. bovoculi , M. bovis and M. ovis . A secondary hypothesis tested that IBK cases were not associated with increased prevalence of M. bovoculi , M. bovis and M. ovis . Results 23% of 77 eyes developed IBK. M. ovis was identified in one IBK-negative eye. The adjusted hazard ratio (HR) for IBK incidence from eyes where M. bovoculi or M. bovis were recovered prior to disease occurrence were not statistically significant ( M. bovoculi HR = 1.38, 95% CI: 0.54–3.53, p  = 0.49, M. bovis HR = 1.60, 95% CI: 0.48–5.53, p  = 0.44). The adjusted hazard ratio for M. bovoculi in IBK lesions was 6.45 (95% CI: 3.35–12.44, p M. bovis in IBK lesions was 2.33 (95% CI: 1.22–4.45, p  = 0.01). Conclusion A temporal association between prior exposure to M. bovoculi or M. bovis and subsequent IBK incidence was not demonstrated. However, M. bovoculi and M. bovis are more frequently recovered from eyes with IBK lesions than unaffected eyes and this provides weak evidence for a causal role.

  • Descriptive epidemiology of Moraxella bovis, Moraxella bovoculi and Moraxella ovis in beef calves with naturally occurring infectious bovine keratoconjunctivitis (Pinkeye).
    Veterinary microbiology, 2011
    Co-Authors: A M O'connor, H G Shen, Chong Wang, Tanja Opriessnig
    Abstract:

    Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that causes substantial weight loss in beef calves. The objective of this study was to evaluate the association between Moraxella bovoculi, Moraxella bovis and Moraxella ovis and IBK incidence. A cohort design was used. From 239 calves and 478 eyes, 77 randomly chosen eyes were monitored for M. bovoculi, M. bovis, M. ovis and IBK incidence over 4 months. One hypothesis tested was that IBK hazard in eyes was not associated with detection of M. bovoculi, M. bovis and M. ovis. A secondary hypothesis tested that IBK cases were not associated with increased prevalence of M. bovoculi, M. bovis and M. ovis. 23% of 77 eyes developed IBK. M. ovis was identified in one IBK-negative eye. The adjusted hazard ratio (HR) for IBK incidence from eyes where M. bovoculi or M. bovis were recovered prior to disease occurrence were not statistically significant (M. bovoculi HR=1.38, 95% CI: 0.54-3.53, p=0.49, M. bovis HR=1.60, 95% CI: 0.48-5.53, p=0.44). The adjusted hazard ratio for M. bovoculi in IBK lesions was 6.45 (95% CI: 3.35-12.44, p<0.001). The adjusted hazard ratio for M. bovis in IBK lesions was 2.33 (95% CI: 1.22-4.45, p=0.01). A temporal association between prior exposure to M. bovoculi or M. bovis and subsequent IBK incidence was not demonstrated. However, M. bovoculi and M. bovis are more frequently recovered from eyes with IBK lesions than unaffected eyes and this provides weak evidence for a causal role. Copyright © 2011 Elsevier B.V. All rights reserved.

L. W. George - One of the best experts on this subject based on the ideXlab platform.

  • Moraxella bovoculi sp. nov., isolated from calves with infectious bovine keratoconjunctivitis.
    International journal of systematic and evolutionary microbiology, 2007
    Co-Authors: John A. Angelos, Louise M. Ball, Phillip Q Spinks, L. W. George
    Abstract:

    Eighteen isolates of a Gram-negative coccus (strain 237(T)) were cultured from the eyes of dairy and beef calves affected with infectious bovine keratoconjunctivitis (IBK; 'pinkeye') in northern California, USA, during summer 2002. These isolates had near full-length (1397 bp) 16S rRNA gene sequences that clustered into three groups with 99.9 % sequence similarity. On the basis of 16S rRNA gene sequence, the isolates were most closely associated with Moraxella bovis and Moraxella ovis in clade I of the classical Moraxellae. Biochemically, the novel isolates could be distinguished from the other members of the genus Moraxella isolated from animals on the basis of phenylalanine deaminase activity. The results of partial sequence analysis of six housekeeping genes, the 16S-23S rRNA gene interspacer region and partial 23S rRNA gene provide strong support for the inclusion of these isolates in a novel taxon, for which the name Moraxella bovoculi sp. nov. is proposed. The type strain is strain 237(T) (=ATCC BAA-1259(T)=CCUG 52049(T)).