Subscapular lymph node abscessation as a result of metastatic Streptococcus equi subspecies equi infection: An atypical presentation of bastard strangles in a mare

The case reported here represents an atypical presentation of bastard strangles in an 18‐year‐old Arab mare. The horse initially presented for progressive neck pain characterised by reluctance to lateral and ventroflexion of the neck. Subsequent diagnostics revealed a subscapular abscess and aspirates of the mass cultured positive for Streptococcus equi ssp. equi. Surgical drainage and debridement of the abscess was performed under general anaesthesia. Six months post surgery, the mare had made a complete recovery.     

Sequelae and complications of Streptococcus equi subspecies equi infections in the horse

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.     

Molecular characterisation of 'strangles' outbreaks in the UK: the use of M-protein typing of Streptococcus equi ssp. equi

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.     

Lessons learned from a strangles outbreak on a large Standardbred farm

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.     

Prevalence and serum protein values of strangles (Streptococcus equi) affected mules at Remount Depot,Sargodha (Pakistan)

The prevalence of Streptococcus equi serovar equi (S.equi) in nasal discharge and pus samples from sub‐mandibular lymph nodes in mules at the Remount Depot, Sargodha was examined and total serum proteins, serum albumin, serum globulin and fibrinogen measured. A total of 250 nasal swabs and pus samples were collected from mules and examined microbiologically: 99 (39.6%) were positive for S. equi. A higher occurrence of S. equi was recorded in foals as compared to adults. The concentrations of total serum protein, serum globulin and fibrinogen were significantly increased (P<0.05), while the concentration of serum albumin significantly decreased (P<0.05) in strangles‐affected mules. It was concluded that increased total serum proteins, serum globulin and fibrinogen along with decreased serum albumin were important indicators of infection by S. equi in mules.     

Long-term successful outcome of a Streptococcus equi subspecies equi brain abscess

We previously described successful treatment, including surgical drainage, of a Streptococcus equi subspecies equi brain abscess that caused severe neurological deficits in a 7-year-old Quarter Horse mare. This report details the long-term successful outcome of the case, findings of a magnetic resonance imaging (MRI) study performed 14 years after surgery and necropsy findings 18 years after initial treatment. Despite persistent cerebral and midbrain lesions detected by MRI and at necropsy, the mare returned to serviceable function within a year of initial treatment and had a successful performance career for over 10 years until carpal arthritis prompted retirement. This case demonstrates that brain abscess in horses can be successfully managed by combined medical and surgical treatment.     

快速鉴定猪链球菌和马链球菌兽疫亚种双重PCR方法的建立

本试验旨在建立一种快速、特异、敏感的双重PCR鉴定猪链球菌和马链球菌兽疫亚种病原检测方法。根据猪链球菌GDH蛋白和马链球菌类 M 蛋白的基因保守区分别设计引物,优化了该双重PCR检测方法的引物浓度及比例,并筛选了其最佳退火温度;用该双重PCR反应体系以其他几株阴性菌株为对照,检测了该反应体系的特异性。以新鲜培养的猪链球菌倍比稀释后进行菌落计数,对该检测方法的敏感性进行了鉴定。M-like和GDH引物的加入量均为1 μL(20 pmol/L),最佳退火温度为52.3℃;该双重PCR反应体系有较高敏感性,检测马链球菌兽疫亚种和猪链球菌的敏感度分别达100和10 CFU;特异性试验结果显示,常见的5种病原菌在该双重PCR体系中无特异性条带出现;临床应用该方法分离鉴定了1株猪链球菌和2株马链球菌兽疫亚种。本试验建立了一种能同时检测猪链球菌和马链球菌兽疫亚种的双重PCR方法,且该方法应用快速、特异且敏感。     

Successful surgical debridement of a cerebral Streptococcus equi equi abscess by parietal bone flap craniotomy in a 2-month-old Warmblood foal

Brain abscesses and intracranial masses have been regularly described in horses. Treatment often is difficult and unrewarding and mortality rate high. This case report describes the successful treatment of a cerebral abscess in a 2-month-old female Warmblood foal with severe neurological signs of acute onset. Computed tomography (CT) revealed a 3 × 4 × 4 cm cerebral mass in the left brain hemisphere with severe cerebral oedema. Craniotomy, using a parietal bone flap technique, allowed the abscess to be sampled, drained and lavaged. Immediately, post-surgery the foal showed significant clinical improvement. Sample culture confirmed Streptococcus equi equi infection. The foal was medically treated for 6 weeks, leading to complete clinical and radiographical recovery. Intracranial surgery in equine medicine is limited. Using a parietal bone flap instead of partial craniectomy to gain access to the cerebrum is a less invasive procedure leading to a better aesthetic result and should be considered for the treatment of cerebral masses in the horse.     

马腺疫链球菌fneB基因LAMP检测方法的建立及应用

为了建立快速简便的fneB-LAMP检测法用于马腺疫病原马链球菌马亚种(S.equi)的检测,本试验采用恒温水浴进行LAMP扩增,建立可视化fneB-LAMP检测方法.结果显示:对大肠埃希菌、无乳链球菌、金黄色葡萄球、蜡状芽孢杆菌和克雷伯杆菌5种菌与标准S.equi菌株检测,只能够检测出标准阳性菌株;对新疆昭苏县3个马...     

Rhodococcus equi (Prescottella equi) vaccines; the future of vaccine development

For decades researchers have been targeting prevention of Rhodococcus equi (Rhodococcus hoagui/Prescottella equi) by vaccination and the horse breeding industry has supported the ongoing efforts by researchers to develop a safe and cost effective vaccine to prevent disease in foals. Traditional vaccines including live, killed and attenuated (physical and chemical) vaccines have proved to be ineffective and more modern molecular‐based vaccines including the DNA plasmid, genetically attenuated and subunit vaccines have provided inadequate protection of foals. Newer, bacterial vector vaccines have recently shown promise for R. equi in the mouse model. This article describes the findings of key research in R. equi vaccine development and looks at alternative methods that may potentially be utilised.     

马链球菌兽疫亚种类M蛋白亚单位疫苗小鼠免疫试验

为获得控制猪链球菌病安全高效的疫苗，本试验进行了马链球菌兽疫亚种类M蛋白亚单位疫苗的研制。应用热酸法提取马链球菌兽疫亚种ATCC35246株类M蛋白，并分别采用羟基磷灰石（HAT）层析和冷酒精沉淀法进行纯化，结果得到较纯的类M蛋白。用热酸提取的粗制类M蛋白、2种纯化的类M蛋白及全菌苗免疫小鼠，结果保护率分别为92％（11／12）、100％（12／12）、100％（12／12）和83％（10／12），表明类M蛋白亚单位疫苗有进一步开发的必要。     

抗马链球菌马亚种组方加味优选及其体内抑菌作用研究

【目的】筛选可抑制马腺疫主要致病菌——马链球菌马亚种的最优中药组方,为临床马腺疫的防治提供参考。【方法】选用赤芍、大黄、山豆根等27种中药,首先通过体外抑菌试验(牛津杯法、最小抑菌浓度(MIC)、最小杀菌浓度(MBC)、联合药敏试验)结合L₈(2⁶)正交试验初步筛选抗马链球菌马亚种中药组方的最佳优选因素,再通过L₁₈(3⁶)正交试验进一步筛选基础组方最佳配比;最后在基础组方的基础上,根据中兽医方剂配伍理论,添加黄芪和当归2味补虚药,通过马腺疫小鼠模型体内抑菌试验筛选加味组方配比,结合组方保护率结果及组织脏器病理变化验证加味组方的体内抑菌作用。【结果】试验筛选出了马链球菌马亚种超敏和高敏的7味中药：浙贝母、赤芍、甘草、大黄、雪白睡莲、山豆根和苦参。大黄、雪白睡莲、山豆根、甘草、苦参和浙贝母的MIC分别为0.078、0.078、0.125、0.156、0.156和0.250 mg/mL。雪白睡莲、赤芍、山豆根、甘草、大黄、苦参和浙贝母的MBC分别为0.078、0.125、0.125、0.156、0.15...