Contagious Equine Metritis Organism Research Articles

Surveillance for the contagious equine metritis organism in the UK, 2005 to 2009

Surveillance for the contagious equine metritis organism in the UK, 2005 to 2009

An investigation into the suitability of a commercial real‐time PCR assay to screen for Taylorella equigenitalis in routine prebreeding equine genital swabs

Standard bacteriological methods for identifying Taylorella equigenitalis in cervical smears are time consuming. Therefore, a more rapid real-time PCR assay was evaluated for its suitability in screening swabs. To compare the results of a commercially available real-time PCR assay with routine microbiological culture for the identification of T. equigenitalis, the causative organism of contagious equine metritis, in equine genital swab samples, under 'field trial' conditions. Routine prebreeding genital swabs (n=2072) collected from Thoroughbred mares and stallions during 2009 were examined together with stored T. equigenitalis positive material. Swabs were cultured for T. equigenitalis using standard microbiological techniques. Bacterial lysates were isolated from the swabs and examined for the presence of a 16S DNA fragment of T. equigenitalis, using a commercial multiplex real-time PCR assay system. There was complete concordance between positive and negative results obtained by the 2 methods. Real-time PCR also detected T. equigenitalis DNA from swabs that were negative using standard microbiological culture after 6 months' storage at +4 degrees C but from which T. equigenitalis had been isolated following collection. The sensitivities of real-time PCR and bacterial culture were both 10(-3) (equivalent to 3 colony-forming units). Routine bacterial culture of T. equigenitalis requires an incubation period of not less than 7 days before a conclusive negative result can be obtained, whereas bacterial extraction and real-time PCR assay can be completed in less than 6 h. The commercially-available PCR assay tested provided a rapid and reliable method for the identification of T. equigenitalis from equine genital swabs and could be usefully employed for the screening of mares and stallions for preseason Horserace Betting Levy Board (HBLB) Code of Practice and in other situations such as for bloodstock sales screening requirements, overcoming the current delays imposed by bacterial culture requirements. Its use could be quality assured by the existing HBLB biannual testing scheme for designated laboratories.

Phylogenetic Position of Taylorella equigenitalis Determined by Analysis of Amplified 16S Ribosomal DNA Sequences

The 16S ribosomal DNA sequence of Taylorella equigenitalis (formerly Haemophilus equigenitalis), the causative organism of contagious equine metritis, was determined. A phylogenetic analysis of this sequence revealed a phylogenetic position of T. equigenitalis in the beta subclass of the class Proteobacteria apart from the position of Haemophilus influenzae, which belongs to the gamma subclass of Proteobacteria. A close phylogenetic relationship among T. equigenitalis, Alcaligenes xylosoxidans, and Bordetella bronchiseptica was detected; Spirillum volutans and Chromobacterium fluviatile (Iodobacter fluviatile) were in the same group but slightly removed. This relationship is surprising in view of the considerable differences in the G + C contents of the genomes of these bacteria.

Did vaccinia virus come from a horse?

Equine Veterinary JournalVolume 25, Issue 1 p. 8-10 Did vaccinia virus come from a horse? C. E. D. TAYLOR, C. E. D. TAYLOR Alnwick House, High Street, Little Shelford, Cambridge CB2 5ES UK. Dr Taylor retired from the post of Director of the Regional Public Health Laboratory in Cambridge 1988. During his term of office he was responsible for identifying the causal organism of contagious equine metritis now named Taylorella equigenitalis.Search for more papers by this author C. E. D. TAYLOR, C. E. D. TAYLOR Alnwick House, High Street, Little Shelford, Cambridge CB2 5ES UK. Dr Taylor retired from the post of Director of the Regional Public Health Laboratory in Cambridge 1988. During his term of office he was responsible for identifying the causal organism of contagious equine metritis now named Taylorella equigenitalis.Search for more papers by this author First published: January 1993 https://doi.org/10.1111/j.2042-3306.1993.tb02892.xCitations: 7 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume25, Issue1January 1993Pages 8-10 RelatedInformation

Identification of anatomic features of the equine clitoris as potential growth sites for Taylorella equigenitalis

Summary A median clitoral sinus, as a space canalized from epithelial cells, was distinguishable developmentally in equine fetuses from 33-mm crownrump length (crl) to 500-mm crl (including a mule of 21-mm crl). In saggital sections of the clitoris of a 480-mm crl fetus, indentations under the transverse frenular fold were identified as lateral sinuses of the clitoris. Unlike the median sinus, they were shallow; it therefore could not be anatomically substantiated that the lateral sinuses were of sufficient depth to support the growth of the partial anaerobe Taylorella equigenitalis, the organism of contagious equine metritis. This study indicated excision of the lateral clitoral sinuses was unnecessary for treatment of contagious equine metritis.

Specific antibody in the equine genital tract following local immunisation and challenge infection with contagious equine metritis organism (Taylorella equigenitalis)

Antibody in serum, uterine and vaginal secretions was measured following local immunisation and experimental infection with the organism of contagious equine metritis (Taylorella equigenitalis). Intrauterine immunisation with killed T equigenitalis stimulated a systemic IgG titre and a uterine IgA and IgM response. Subsequent challenge with the organism, however, resulted in a characteristic metritis in both control and vaccinated mares. Antibody in serum and secretions was increased following challenge infection, dwarfing the response to immunisation. The local response was restricted to the IgA and IgM classes in both uterine and vaginal secretions. There was no elevation in local IgG antibody, although there was an increase in serum IgG in response to challenge infection. A second experimental challenge, following natural resolution of the initial infection and a period of reimmunisation, resulted in reduced clinical signs and bacterial isolation rates from both control and vaccinated mares, but no absolute protection from infection.

Nonimmune binding of equine immunoglobulin by the causative organism of contagious equine metritis, Taylorella equigenitalis.

This study identifies nonimmune binding of equine immunoglobulin by the causative organism of contagious equine metritis. Immunoglobulin binding to the bacterium was strongest for immunoglobulin G (IgG) and less for IgM; IgA was not bound. Binding of equine IgG was inhibited by human IgG, but not by IgG of domestic animals. Immunoglobulin binding by the bacterium appeared to be directed towards an epitope in the hinge region of the immunoglobulin molecule.

Variable persistence of the contagious equine metritis organism in the genital tract of [formula omitted], [formula omitted], [formula omitted], [formula omitted] and congenitally thymus-deficient (nude) mice

Five inbred strains of mice, CBA J , CBA N , LAF 1, BALB c and congenitally thymus-deficient nude mice of BALB c background, varied considerably in their susceptibility to the contagious equine metritis organism (CEMO). Whereas all the strains were virtually refractive to vaginal challenge, LAF 1 and CBA N mice were readily infected by intra-uterine inoculation. Based on infection rate and nature of the bacteriological response, CBA N mice appeared the more susceptible of the 2 strains. Attempts to transmit CEMO to thymus-deficient nude mice were unsuccessful by both of these routes of challenge and by intraperitoneal inoculation, indicating that host resistance to the causal agent is independent of thymus-mediated immune phenomena. No clinical evidence of infection was observed in any of the experimentally infected mice. Although persistence of CEMO in the female reproductive tract varied widely, it could be isolated from some of the CBA N mice for as long as 19 weeks after challenge by the intra-uterine route. The organism was cultured from the ovaries and/or oviducts of a high percentage of one group of CBA N mice after 50 days, when it could no longer be recovered from the remainder of the genital tract. Limited attempts to achieve venereal transmission of CEMO between culture-positive female and companion male CBA N mice were unsuccessful. The relative susceptibility of the CBA N strain of mice to CEMO would suggest that host resistance to this infection is at least partly dependent on the presence of a fully functional B lymphocyte system. Further studies in this experimental model may elucidate some of the immunological mechanisms underlying development of resistance in the horse, more specifically as they relate to the occurrence of the carrier state in this disease.

Morphology of three strains of contagious equine metritis organism

Examination of recently isolated cultures of three strains of Contagious Equine Metritis Organism grown on specially formulated, serum-free, clear typing medium revealed the presence of numerous colonial opacity variants. These colonies were prepared by a number of fixation and staining techniques and examined by scanning and transmission electron microscopy. Opaque and transparent phenotypes produced copious amounts of extracellular material compared with intermediate-opacity phenotypes which produced little or none. Also unique to intermediate colonies were numerous thin intercellular strands, which may represent pili or polymers of extracellular material. The presence of an unusual fibrillar layer (with similar electron density to the extracellular material) on the outer leaf of the outer membrane also was confirmed. A number of other ultrastructural features also were noted, including an epilayer, a thin nonmembranous layer which covered colonies and adjacent agar.

Incubation times for primary isolation of the contagious equine metritis organism.

Incubation times for primary isolation of the contagious equine metritis organism.

Transmissibility of the contagious equine metritis organism for the cat

A group of SPF cats were moderately susceptible to the causal organism of contagious equine metritis (CEM) following intra-uterine or intrapreputial challenge with an Irish streptomycin resistant strain isolated from a clinically infected mare. Subclinical infections were established in only 50% of the cats, none of which became long-term carriers of the organism. Cytological examination of vaginal smears was of no diagnostic value in confirming infection in inapparently infected cats. Bacteriological responses after primary or secondary challenge with the CEM organism were essentially similar, with one exception, a female cat in which there was possible evidence of local immunity persisting after the primary infection. Efforts to reactivate shedding subsequent to the immediate post-challenge period were unsuccessful. Throughout the experimental period, the cats remained sero-negative to the complement-fixation test, and they failed to develop any significant increase in the levels of antibody activity as measured by the kinetics-based ELISA or KELA system. On day 89 after primary challenge, the cats were euthanized and various sites in the genitourinary tract and the internal iliac lymphatic glands subjected to bacteriological and pathological examination for evidence of CEM infection with negative results. The findings of this study, although establishing the transmissibility of the CEM organism for the cat, demonstrate the limited value of this species as an experimental model system for the disease in the horse.

Evaluation of selective supplements used in media for the isolation of the causative organism of contagious equine metritis.

Evaluation of selective supplements used in media for the isolation of the causative organism of contagious equine metritis.

Activity of cefotaxime, a beta-lactam antibiotic, against the contagious equine metritis organism

Activity of cefotaxime, a beta-lactam antibiotic, against the contagious equine metritis organism

Comparison of Haemophilus Equigenitalis (Contagious Equine Metritis Organism) and Other Haemophilus Species by Disc Electrophoresis of Acid-Phenol-Soluble Proteins

SUMMARY Comparison of the structural proteins of Haemophilus equigenitalis with those of other Haemophilus spp. by electrophoresis of acid-phenol-soluble proteins failed to reveal any similarity. In contrast the other Haemophilus spp. showed a close similarity to each other in protein migration patterns.

Lesions of contagious equine metritis in mares.

Twenty-three mares were infected with contagious equine metritis organism by intrauterine inoculation, and necropsied after intervals of two to 116 days. Severe diffuse subacute salpingitis was seen in one mare, and mild multifocal subacute salpingitis was common. Severe diffuse endometritis and cervicitis initially were acute and became more severe, subacute and predominantly plasmacytic by 14 days, then declined but persisted as mild diffuse or multifocal inflammation for the rest of the experimental period. Vaginitis arose in parallel but resolved after 70 days. There were no lesions in the clitoral fossa or clitoral sinus.

Interaction of Haemophilus equigenitalis (contagious equine metritis organism) with lectins.

Interaction of Haemophilus equigenitalis (contagious equine metritis organism) with lectins.

Characterization of the major antigens of Haemophilus equigenitalis (contagious equine metritis organism).

Immunoelectrophoresis of ultrasonically disrupted Haemophilus equigenitalis (contagious equine metritis organism) cells against rabbit and equine antisera disclosed at least 11 precipitating antigens. Two of these, a polysaccharide and a lipopolysaccharide-protein complex, were of high molecular weight and located on the cell surface. The remaining antigens were intracellular and were small- to medium-sized proteins. The surface antigens were the most significant in relation to the serological response in infected horses. They also reacted with sera from apparently healthy cattle, but the reason for this was not determined. No serological cross-reaction between H. equigenitalis and species of Achromobacter and Moraxella was detected.

Isolation of the contagious equine metritis organism from colts and fillies in the United Kingdom and Ireland.

Between January 1978 and August 1982 the streptomycin resistant strain of the contagious equine metritis organism (CEMO) was isolated from 15 colts and two fillies in the United Kingdom and Ireland. A first season stallion was also suspected of having initiated an outbreak of contagious equine metritis (CEM) at the beginning of the 1982 breeding season. A detailed investigation of the breeding history of the dams and sires of each positive individual indicated that in a number of cases the CEMO was acquired either in utero or following transmission at the time of parturition. In several other cases the retrospective evidence suggested that the genital tract of colt foals became contaminated with vaginal discharge from mares showing clinical signs of the disease during the nursing period. The findings emphasise the need for a thorough examination of the genital tract of colts and fillies as recommended in the code of practice for the control of CEM when they begin their breeding career.

Phagocytosis and intracellular killing of the contagious equine metritis organism by equine neutrophils in serum.

Equine neutrophils were combined with Haemophilus equigenitalis (contagious equine metritis organism; CEMO) or Escherichia coli in low- and high-antibody-titer serum to evaluate the neutrophils ability to phagocytize and kill these bacteria. More E. coli than CEMO were phagocytized at each time period. After 120 min in low-antibody-titer serum, 56.3% of the E. coli and 34.3% of the CEMO were phagocytized. A total of 45% of CEMO and 74.9% of E. coli were phagocytized by 120 min when neutrophils were in high-antibody-titer serum. More than 75% of the ingested E. coli and 90% of the ingested CEMO were killed within 210 min of incubation. Fewer E. coli than CEMO were killed at any given time period. Ultrastructural examination showed CEMO to be degraded in the neutrophil. Degradation was the most extensive in neutrophils in high-titer serum. It is suggested that CEMO is a pathogenic extracellular bacterium incapable of prolonged intracellular survival and that it is slower to be phagocytized than a nonpathogenic E. coli.

Improved selective medium for isolation of the contagious equine metritis organism

Improved selective medium for isolation of the contagious equine metritis organism