Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
BMC Vet Res. 2023 Oct 17;19(1):210. doi: 10.1186/s12917-023-03772-4.
Beta-hemolytic streptococci involving the upper respiratory tract cause strangles and strangles-like diseases in horses and cause severe economic damage to the equestrian club each year. Therefore, careful epidemiological study of these bacteria, evaluation of phylogenetic connections and SeM-typing can be useful to determine the source and epidemiological characteristics of the disease outbreak. Isolates were analyzed using molecular and phylogenetic methods and to determine antibiotic resistance pattern in Iranian isolates. Molecular and phylogenetic methods were used to evaluate Iranian streptococcal isolates, and the similarity of the Iranian SeM-97 sequence with other alleles was assessed using the Neighbor-joining method with the Kimura 2 Parameter statistical model. The amino acid sequence of this gene was compared with the predicted SeM-3 reference amino acid sequence (FM204883) using MEGA 7 software.
One type of SeM was found among streptococcal isolates. This type (SeM-97) was reported for the first time and was a new SeM. The relationship between streptococcal isolates and age, sex, race, clinical signs and geographical area was investigated. A significant relationship was observed between streptococcal isolates with age variables and clinical symptoms.
In our study, a Streptococcus equi subsp. equi genotype was identified. The 97 allele of this gene has not been officially reported anywhere and is only registered in the Public databases for molecular typing and microbial genome diversity (PubMLST)-SeM database by Katy Webb. This was the first isolate reported and registered in the mentioned database. The isolate (Tabriz61) had the SeM-97 allele with clinical signs including mucopurulent discharge, abnormal sounds in lung hearing, warmth and enlargement or discharge and abscess of retropharyngeal lymph node and fever. This isolate was sensitive to penicillin, meropenem, ampicillin, cefotaxime, tetracycline, erythromycin, azithromycin, chloramphenicol, enrofloxacin and ciprofloxacin antibiotics and resistant to trimethoprim-sulfamethoxazole and gentamicin antibiotics.
涉及上呼吸道的β-溶血性链球菌可引起马的马腺疫和类马腺疫疾病，并导致马术俱乐部每年遭受严重的经济损失。因此，对这些细菌进行仔细的流行病学研究、评估系统发育关系和 SeM 型分析有助于确定疾病爆发的来源和流行病学特征。本研究采用分子和系统发育方法对分离株进行分析，并确定伊朗分离株的抗生素耐药模式。采用分子和系统发育方法对伊朗链球菌分离株进行评估，并使用基于 Kimura 2 参数统计模型的邻接法（Neighbor-joining method）评估伊朗 SeM-97 序列与其他等位基因的相似性。使用 MEGA 7 软件比较该基因的氨基酸序列与预测的 SeM-3 参考氨基酸序列（FM204883）。
在链球菌分离株中发现了一种 SeM 型。这种类型（SeM-97）是首次报道，是一种新的 SeM。研究了链球菌分离株与年龄、性别、种族、临床症状和地理区域之间的关系。链球菌分离株与年龄变量和临床症状之间存在显著关系。
在本研究中，鉴定出一种马链球菌马亚种基因型。该基因的 97 等位基因尚未在任何地方正式报道，仅在分子分型和微生物基因组多样性公共数据库（PubMLST）-SeM 数据库中由 Katy Webb 注册。这是第一个在该数据库中报道和注册的分离株。分离株（Tabriz61）具有 SeM-97 等位基因，临床症状包括脓性分泌物、肺部听诊异常音、温热、咽后淋巴结肿大或排脓和脓肿以及发热。该分离株对青霉素、美罗培南、氨苄西林、头孢噻肟、四环素、红霉素、阿奇霉素、氯霉素、恩诺沙星和环丙沙星抗生素敏感，对甲氧苄啶-磺胺甲噁唑和庆大霉素抗生素耐药。
