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1.

Background

Streptococcus equi ssp. equi is the causative agent of ‘Strangles’ in horses. This is a debilitating condition leading to economic loss, yard closures and cancellation of equestrian events. There are multiple genotypes of S. equi ssp. equi which can cause disease, but to date there has been no systematic study of strains which are prevalent in Ireland. This study identified and classified Streptococcus equi ssp. equi strains isolated from within the Irish equine industry.

Results

Two hundred veterinary isolates were subjected to SLST (single locus sequence typing) based on an internal sequence from the seM gene of Streptococcus equi ssp equi. Of the 171 samples which successfully gave an amplicon, 162 samples (137 Irish and 24 UK strains) gave robust DNA sequence information. Analysis of the sequences allowed division of the isolates into 19 groups, 13 of which contain at least 2 isolates and 6 groups containing single isolates. There were 19 positions where a DNA SNP (single nucleotide polymorphism) occurs, and one 3 bp insertion. All groups had multiple (2–8) SNPs. Of the SNPs 17 would result in an amino acid change in the encoded protein. Interestingly, the single isolate EI8, which has 6 SNPs, has the three base pair insertion which is not seen in any other isolate, this would result in the insertion of an Ile residue at position 62 in that protein sequence. Comparison of the relevant region in the determined sequences with the UK Streptococcus equi seM MLST database showed that Group B (15 isolates) and Group I (2 isolates), as well as the individual isolates EI3 and EI8, are unique to Ireland, and some groups are most likely of UK origin (Groups F and M), but many more probably passed back and forth between the two countries.

Conclusions

The strains occurring in Ireland are not clonal and there is a considerable degree of sequence variation seen in the seM gene. There are two major clades causing infection in Ireland and these strains are also common in the UK.  相似文献   

2.
Strangles is one of the most frequently diagnosed equine respiratory infectious diseases in the world. It is caused by Streptococcus equi subsp. equi (S. equi), and it is an acute infection characterized by pyrexia, nasal discharge, pharyngitis, and abscessation of lymph nodes. Frequently, healthy horses might continue to harbor S. equi after clinical recovery. Although the genetic distance between S. equi isolates is short, strains can be differentiated by pulsed-field gel electrophoresis (PFGE) and single locus sequence typing for epidemiological studies. The aim of this study was to characterize by PFGE Argentine isolates of S. equi obtained from horses with acute strangles and those that had recovered. Bacterial isolation and identification of 80 S. equi isolates by phenotypic and genotypic tests were performed using samples from 29 horses with acute strangles and 95 from healthy animals. Also, the isolates were characterized by PFGE using Bsp120I and SmaI. Visual comparison of macrorestriction patterns generated with both enzymes revealed three different DNA fragment profiles with variations of one or two bands. Interestingly, an identical profile was found in isolates from the same horse and from horses that were infected at the same time, and the horses recovered from strangles continue to carry the same strain. Some vaccinated horses have been mild infected for a different strain from that of carriers suggesting other source of infection. This is the first molecular characterization of Argentine isolates of S. equi, which shows the presence of three strains between 2010 and 2013 in Buenos Aires.  相似文献   

3.
Reasons for performing study: Strangles is the most commonly diagnosed and important infectious disease of horses worldwide. Very little is known about the temporo‐spatial and molecular epidemiology of strangles. The disease is not notifiable in the UK and there are few published data on the geographical locations of outbreaks. Objective: To investigate whether typing of a surface protein (SeM) of Streptococcus equi ssp. equi (S. equi), the causative agent of strangles, is a useful epidemiological tool. Methods: The variable region of the SeM gene was amplified from 145 isolates of S. equi by PCR and sequenced. Different SeM gene alleles were assigned based on the SeM database, grouped into phylogenetic clusters using split decomposition analysis and plotted against the submitting veterinary practices. Results: In this study 21 S. equi SeM alleles were found, including 9 previously unidentified alleles and representing 4 phylogenetic groups. S. equi containing SeM alleles 9 and 7 were the most commonly isolated and there was a high number of low frequency alleles. The occurrence of an outbreak cluster in the north‐west of the UK is also reported. Conclusions: Strangles outbreaks can be differentiated on the basis of their SeM allele sequences. The data provide further evidence of SeM mutation leading to the emergence of novel, but related SeM alleles that are geographically linked. Sequencing of the SeM gene is a useful tool for the elucidation of strangles epidemiology at a regional and a national level. Potential relevance: This technique may allow differentiation or linkage of strangles outbreaks and as such may be an effective tool for local as well as national and international disease surveillance.  相似文献   

4.
The objective of this study was to use a new subtyping technique to determine the identity of five Streptococcus equi isolates from four outbreaks of strangles in Colorado during 2005−2006. All five of the isolates from the four strangles outbreaks in Colorado contained SeM allele 28. This SeM allele is typical of American isolates of S. equi and has previously been linked with strangles outbreaks in Minnesota in 1994 and Kentucky in 1995. Use of the new S. equi strain subtyping method allowed for characterization of recent S. equi isolates associated with outbreaks of strangles in Colorado. To our knowledge, this is the first report of typing of more recent isolates from North America. This approach, however, has been used in situations in the United Kingdom to differentiate the vaccine strain of S. equi from that of the wild type of the bacteria.  相似文献   

5.
Streptococcus equi subspecies (ssp.) equi infection (strangles) remains one of the most frequently diagnosed and costly infectious diseases of horses. Large breeding herds, where a disease outbreak competes for personnel and financial resources needed for foaling management, present a special challenge for equine practitioners. A 15‐month outbreak involving 62 clinical cases of strangles occurred on a large Standardbred breeding farm (average population of 1400 horses). Sixteen asymptomatic horses were found to be PCR (polymerase chain reaction)‐positive for S. equi ssp. equi. During the outbreak, serological samples from 48 clinically normal horses were found to be seropositive for S. equi ssp. equi, confirming herd‐wide exposure. After several clinical cases of strangles had been diagnosed, an intranasal S. equi ssp. equi vaccine was administered to clinically normal horses (n = 558) considered to be at risk of exposure. Strangles complications included 7 fatalities (none in vaccinated horses) and 6 cases of purpura haemorrhagica (4 in vaccinated horses). Midway through the outbreak, injectable, sustained release ceftiofur crystalline free acid (CCFA), given as an initial dose followed by a second dose 4 days later, was used exclusively for systemic antimicrobial treatment of clinically affected and PCR‐positive horses. This antimicrobial regimen coincided with a reduction in disease incidence and eventual resolution of the outbreak. Two horses with persistent guttural pouch infection were endoscopically confirmed as carrier horses. The herd history demonstrated that a strangles outbreak will often result in asymptomatic carrier horses and that identification and treatment of these horses are necessary to eliminate long‐term sources of infection. Ceftiofur crystalline free acid was found to be a suitable antimicrobial due to its activity against S. equi ssp. equi and the efficiencies associated with twice parenteral dosing during a 10‐day treatment period. Occurrence of purpura in 4 vaccinated horses suggests that vaccination should be reserved for healthy seronegative horses and avoided during an active outbreak.  相似文献   

6.
从新疆地区某驴养殖场获得了3株驴腺疫链球菌分离株HTP133、HTP123和HTP232.为了解这3株驴腺疫链球菌的生物学特性和确定其分子分型,本研究对其进行了生化特性、药敏特性的检测,对16S rRNA进行序列对比分析,并利用PCR扩增SeM等位基因和测序鉴定其基因型.研究结果表明3株分离菌均为马链球菌马亚种.药敏试...  相似文献   

7.
Strangles, caused by the Gram‐positive bacteria Streptococcus equi subspecies equi (S. equi), is a highly contagious upper respiratory infection in horses. The infection is transmitted by inhalation or direct contact with mucopurulent discharge from an infected animal, resulting in fever, depression, and submandibular and retropharyngeal lymph node enlargement that can lead to respiratory distress. Complications include secondary cellulitis at external abscessation sites, guttural pouch empyema and its persistence into the carrier state, purpura haemorrhagica, metastatic abscessation, emergency tracheostomies and rarely secondary S. equi pneumonia or myositis. Control of outbreaks requires strict isolation protocols and hygiene measures. Detection methods of the index case and carrier state are constantly being refined to assist in the identification and prevention of disease perpetuation.  相似文献   

8.
Present study was undertaken to study the prevalence of β-haemolytic streptococci in equine of northern temperate region of Jammu and Kashmir, India. One hundred and forty one samples were collected in duplicate from nasopharyngeal tract of diseased (53) and apparently healthy equine (88) for isolation and direct PCR. A total of 77 isolates of streptococci were recovered from 141 samples with an overall prevalence rate of 54.60%. Out of these 77 isolates, 52 were from diseased and 25 from apparently healthy animals. Of the 77 isolates, 4 were identified as Streptococcus equi subsp. equi, 56 as S. equi subsp. zooepidemicus and 17 as S. dysgalactiae subsp. equisimilis. Thus the overall prevalence of S. equi subsp. equi, S. equi subsp. zooepidemicus and S. dysgalactiae subsp. equisimilis was 2.83, 39.71 and 12.05% respectively. The sensitivity of the PCR for the detection of S. equi species was found higher when attempted from direct swab samples.  相似文献   

9.
Streptococcus equi ssp. equi infection in the horse, or strangles, commonly results in abscessation of the submandibular, submaxillary or retropharyngeal lymph nodes. Although this classical presentation of strangles is associated with a low mortality rate, complications and sequlae may worsen the prognosis and increase mortality rates. This article reviews sequelae and complictions of S. equi ssp. equi infection in the horse, including guttural pouch empyema, bastard strangles and immune mediated diseases such as purpura haemorrhagica, myopathies and myocarditis.  相似文献   

10.
Genome sequencing data for Streptococcus equi subspecies equi and zooepidemicus were used to develop a novel diagnostic triplex quantitative PCR (qPCR) assay targeting two genes specific to S. equi (eqbE and SEQ2190) and a unique 100 base pair control DNA sequence (SZIC) inserted into the SZO07770 pseudogene of S. zooepidemicus strain H70. This triplex strangles qPCR assay can provide results within 2 h of sample receipt, has an overall sensitivity of 93.9% and specificity of 96.6% relative to the eqbE singlex assay and detects S. equi at levels below the threshold of the culture assay, even in the presence of contaminating bacteria.  相似文献   

11.
This study aimed to validate a point-of-care polymerase chain reaction (PCR) assay for detection of Streptococcus equi subsp. equi (S. equi) in rostral nasal swabs from horses with suspected acute strangles and to compare the results against the molecular gold standard of quantitative polymerase chain reaction (qPCR). Two hundred thirty-two individual swabs of rostral nasal passages were characterized by qPCR as S. equi positive, S. equi subsp. zooepidemicus (S. zooepidemicus) positive, or S. equi and S. zooepidemicus negative. The specificity and sensitivity of the point-of-care PCR assay were 89% and 84%, respectively. The limits of detection of the qPCR assay and the point-of-care PCR analyzer were 3 and 277 eqbE target genes of S. equi, respectively. Overall agreement and short turnaround time make the point-of-care PCR assay a potential molecular diagnostic platform that will enhance the capability of equine veterinarians to timely support a diagnosis of strangles and institute proper biosecurity protocols.  相似文献   

12.
In this study, to evaluate the influence of strangles vaccination on serological test results, we investigated the changes in strangles serum antibody levels in horses after vaccination and subsequent intranasal challenge with S. equi. The horses were vaccinated for strangles with either a component vaccine (Group C) or a live vaccine (Group L). We measured changes in strangles serum antibody levels weekly for 20 weeks after vaccinating horses twice for strangles over a 3-week interval, and for 7 weeks after intranasal challenge with S. equi in the same horses. Serum antibody responses to the proline-glutamic acid-proline-lysine (PEPK) antigen with five repetitions (PEPK-5R) were higher at all times (up to 2.4-fold) following vaccination in Group C than in Group L, and the value peaked at 2.9-fold above the initial value after the second vaccination in Group C horses. However, the value was lower than that in horses infected with S. equi, and it gradually decreased, reaching the initial (week 0) value by the 15th week. Serum antibody responses to PEPK-5R after challenge with S. equi increased in both groups of horses, but the value tended to be lower than that reported for unvaccinated horses. In addition, the average value in Group C was 2.6-fold higher than that of Group L. These results suggest the serum antibody responses of horses infected with S. equi varies according to the type of vaccine with which they have been vaccinated. Although the serological diagnostic test for strangles in which PEPK-5R is used as an antigen is effective for the investigation of serum antibodies to strangles in vaccinated horses, the present data suggest it is necessary to consider the vaccination history when interpreting the results.  相似文献   

13.
Strangles is a serious respiratory disease in horses caused by Streptococcus equi subspecies equi (S. equi). Transmission of the disease occurs by direct contact with an infected horse or contaminated equipment. Genetically, S. equi strains are highly homogenous and differentiation of strains has proven difficult. However, the S. equi M-protein SeM contains a variable N-terminal region and has been proposed as a target gene to distinguish between different strains of S. equi and determine the source of an outbreak. In this study, strains of S. equi (n=60) from 32 strangles outbreaks in Sweden during 1998-2003 and 2008-2009 were genetically characterized by sequencing the SeM protein gene (seM), and by pulsed-field gel electrophoresis (PFGE). Swedish strains belonged to 10 different seM types, of which five have not previously been described. Most were identical or highly similar to allele types from strangles outbreaks in the UK. Outbreaks in 2008/2009 sharing the same seM type were associated by geographic location and/or type of usage of the horses (racing stables). Sequencing of the seM gene generally agreed with pulsed-field gel electrophoresis profiles. Our data suggest that seM sequencing as a epidemiological tool is supported by the agreement between seM and PFGE and that sequencing of the SeM protein gene is more sensitive than PFGE in discriminating strains of S. equi.  相似文献   

14.
Streptococcus equi subsp. zooepidemicus is the pathogen most commonly isolated from the uterus of mares. S. zooepidemicus is an opportunistic pathogen and part of the resident flora in the caudal reproductive tract. The aim of this study was to investigate whether a genotypically distinct subpopulation of S. zooepidemicus is associated with endometritis in the mare, by genotyping and comparing uterine S. zooepidemicus strains with isolates from the vagina and clitoral fossa. Mares with (n = 18) or without (n = 11) clinical symptoms of endometritis were included. Uterine samples were obtained using a guarded endometrial biopsy punch, whereas a swab was used to recover samples from the cranial vagina and the clitoral fossa. If S. zooepidemicus was present, up to three colonies were selected from each anatomical location (max. 9 isolates per mare). Bacterial isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). S. zooepidemicus was isolated from the endometrium of 12 mares. A total of 88 isolates were analyzed by PFGE: 31 from the endometrium, 26 from the cranial vagina and 31 isolates from the clitoral fossa. For MLST 21 isolates were chosen. Results demonstrated a higher genetic similarity of the isolates obtained from infectious endometritis compared to isolates obtained from the caudal reproductive tract. In conclusion, we demonstrate for the first time that a genetically distinct group of S. zooepidemicus is associated with infectious endometritis in the mare.  相似文献   

15.
Although the strangles disease of Streptococcus equi was discovered many decades ago in 1,251 by Jordanus Ruffus, it has still remained a major frequently diagnosed infection in horses all over the world. The S. equi subspecies pathogen is known to be often resistant to antibiotic treatment, and it makes the antibiotics inefficient; hence, this review was conducted to study how the disease can be managed. The age-long sign of this infection is the oozing of pus through the mucous and skin membranes. Affected horses lose appetite, develop fever, and become depressed, which result in them losing weight and becoming lethargic, reducing their physical activity especially when they are being raised for athletic and sport purposes. This article reviews various solutions proffered by several researchers about the healthy performance impacts of S. equi in equine.  相似文献   

16.
Rhodococcus equi causes suppurative pneumonia in foals aged 1–3 months; moreover, it has emerged as a pathogenic cause of zoonotic diseases. After the initial report of the ruminant-pathogenic factor VapN encoded by the novel virulence plasmid pVAPN, several reports have described ruminant infections caused by vapN-harboring R. equi. Herein, we conducted a serological epidemiological surveillance in goats at a breeding farm (Farm A) and characterized the vapN-harboring R. equi isolates from this farm. First, we established a simple screening enzyme-linked immunosorbent assay (ELISA) using recombinant glutathione S-transferase–tagged VapN as an immobilized antigen. This method revealed that the VapN antibody titers were elevated in 12 of 42 goats. Subsequently, we attempted to isolate R. equi from the goat feces and soil of Farm A. choE+/vapN+ R. equi was isolated from the feces of Goat No. 27 and a soil sample near the shed. The pulsed-field gel electrophoresis (PFGE) patterns of five vapN-harboring R. equi strains isolated from Farm A in 2013 and 2019 were investigated and found to be the same except for the strain (OKI2019F1). However, no difference was observed in VapN expression and growth in macrophages among these vapN-harboring R. equi isolates. Our results revealed that some goats had histories of vapN-harboring R. equi infections, and two genomic types of vapN-harboring R. equi were found in isolates from Farm A. Ruminant-specific (pVAPN-carrying) R. equi might be an unrecognized pathogen in Japan and further studies are required to determine its prevalence and distribution.  相似文献   

17.
Rhodococcus equi pneumonia is a major cause of morbidity and mortality in neonatal foals. Much effort has been made to identify preventative measures and new treatments for R. equi with limited success. With a growing focus in the medical community on understanding the genetic basis of disease susceptibility, investigators have begun to evaluate the interaction of the genetics of the foal with R. equi. This review describes past efforts to understand the genetic basis underlying R. equi susceptibility and tolerance. It also highlights the genetic technology available to study horses and describes the use of this technology in investigating R. equi. This review provides readers with a foundational understanding of candidate gene approaches, single nucleotide polymorphism‐based, and copy number variant‐based genome‐wide association studies, and next generation sequencing (both DNA and RNA).  相似文献   

18.
Theileria equi (T. equi) is an obligate intra- and extra-erythrocytic parasite that causes equine theileriosis (ET) in equids. Equine theileriosis is considered a notifiable disease of global significance, a major constraint to the international movement of horses, and endemic in many countries. This disease may be difficult to diagnose, as it can produce variable and nonspecific clinical signs. A cross-sectional study was designed for the molecular characterisation of T. equi and to investigate the associated risk factors of ET accompanied by its consequences on haematological and sero-biochemical parameters. A convenience sampling of 500 blood samples were collected from ET suspect horses from January to December 2017. PCR was performed on all blood samples targeting the 18S rRNA gene of T. equi followed by sequencing; 9% animals tested positive with confirmed sequences. The isolates of this study showed high homology with Cuban, Russian and Brazilian isolates of T. equi (accession numbers KY111762.2 , MG551915.1 and KY952237.1 , respectively). Based on multivariate analysis, the principal risk factors consisted of absence of dogs on the premises and presence of tick infestation. The haemato-biochemical parameters showed a decrease in granulocytes and erythrocytes, and an increase in lymphocytes, monocytes, mean corpuscular volume, mean corpuscular haemoglobin, mean platelet volume, glucose, phosphorus and aspartate aminotransferase in positive horses. This is the first study which identified ET in Punjab (Pakistan) using molecular techniques and risk factors together with the haemato-biochemical variations in horses.  相似文献   

19.
Theileriosis is a worldwide protozoal tick-borne disease caused by Theileria equi, which may produce a variety of clinical signs and turn infected horses into lifetime carriers. This study has aimed to perform a serological and molecular detection of T. equi and associated factors in sports horses from six areas of northeastern Brazil. In overall, 59.6% horses were positive by indirect immunofluorescence assay and 50.4% by polymerase chain reaction. No significant association was found when presence of ticks, age, gender, anemia or total plasma proteins was analyzed with seropositivity and molecular techniques. Although a significant association of infection was found in two cities. Thus, local risk factors other than presence of ticks, horse age, gender, anemia and total plasmatic proteins may dictate prevalence of T. equi infection in sports horses, even in highly endemic areas with no control of infection prior to horse competitions.  相似文献   

20.
A cross-sectional study was carried out on equids (horses, mules and donkeys) in Andalusia, Southern Spain, to assess the level of exposure to equine piroplasmosis and to investigate risk factors associated with these infections. At least one animal seropositive for Theileria equi and/or Babesia caballi was detected in 222/380 (58.4%) herds sampled by competitive inhibition ELISAs. The seroprevalences for B. caballi and T. equi were 13.2% and 56.1%, respectively; there was serological evidence of co-circulation of both piroplasms in 10.8% of herds. Antibodies against equine piroplasms were detected in 286/537 (53.3%) animals; 61 (11.4%) were seropositive for B. caballi, 270 (50.3%) were seropositive for T. equi and 24 (8.4%) were seropositive for both T. equi and B. caballi.There was a significantly higher seroprevalence of B. caballi in mules (32.1%) compared with donkeys (17.0%) and horses (7.9%), and a significantly higher seroprevalence of T. equi in mules (66.1%) in comparison with horses (48.6%), but not donkeys (47.2%). There were significant differences in prevalence of both piroplasms among locations; the seroprevalence of B. caballi ranged from 0 to 22.5%, while the seropositivity to T. equi ranged from 26.7 to 63.3%. A multiple logistic regression model indicated that the risk factors associated with a higher T. equi seroprevalence were increased age, presence of ticks and vaccination against other diseases. Risk factors associated with a higher seroprevalence of B. caballi were species (mules compared to horses), entry of horses in the last 6 months, presence of ticks and presence of shelter. The findings indicate widespread exposure to equine piroplasmosis in Southern Spain.  相似文献   

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