Institudo de Ciencias Clínicas Veterinarias, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
Institudo de Ciencias Clínicas Veterinarias, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile; Departamento de Patologia, UNESP, Teriogenologia e Saúde Única-Faculdade de Ciências Agrárias e Veterinarias Universidade Estadual Paulista (FCAV), Jaboticabal, São Paulo 14884-900, Brazil.
Acta Trop. 2021 Oct;222:106046. doi: 10.1016/j.actatropica.2021.106046. Epub 2021 Jul 15.
This study aimed to perform a molecular survey and identification of hemotropic Mycoplasma spp. in domestic South American Camelids from Southern Chile. Conventional PCR (cPCR) for hemotropic Mycoplasma spp. based on 16S rRNA gene (620bp fragment) was performed in 87 EDTA-blood samples taken from 48 llamas (Lama glama) and 39 and alpacas (Vicugna pacos) from to Temuco, La Araucanía region and Valdivia, Los Rios region, Southern Chile. 16S rRNA hemotropic Mycoplasma PCR-positive were sequenced for species identification, phylogenetic and haplotype analyses, and further tested by cPCR targeting a fragment (160-210 bp) of the RNaseP (rnpB) gene. Based upon 16S rRNA cPCR results, the overall hemotropic Mycoplasma spp. occurrence in Southern camelids was 9.2% (8/87 [95% CI (4.0-17.3%)]), with five positive alpacas (12.8%; 5/39 [95% CI (4.3-27.4%)]) and three llamas (6.3%; 3/48 [95% CI (1.7-17.2%)]). All 16S rRNA PCR-positive samples were negative for the rnpB gene. Obtained 16S sequences presented high identity (99-100%) by BLASTn analysis to 'Candidatus Mycoplasma haemolamae' from an alpaca in the United Kingdom. Phylogenetic and haplotype analyses of the 16s rRNA gene showed high similarity among 'Candidatus M. haemolamae' sequences of this study and the ones from North America, Europe, and Asia evidencing a low diversity of Chilean samples, with only one haplotype detected (#1). Haplotype #1 from South American Camelids in Chile was worldwide distributed and observed in North America, Europe, and Asia. 'Candidatus M. haemolamae' detected for the first time in South American camelids in Southern Chile had low diversity and was worldwide spread.
本研究旨在对智利南部的南美驼羊进行血液传染病原体的分子调查和鉴定。从智利南部特木科（Temuco）的拉拉米加（Lama glama）和瓦尔迪维亚（Valdivia）的洛斯里奥斯（Los Rios）地区的 48 只美洲驼和 39 只羊驼采集 87 份 EDTA 抗凝血样本，采用常规 PCR（cPCR）检测血传支原体属 16S rRNA 基因（620bp 片段）。对 16S rRNA 阳性的血传支原体进行测序以确定种属，进行系统发育和单倍型分析，并进一步采用 cPCR 检测 RNaseP（rnpB）基因的 160-210bp 片段进行检测。根据 16S rRNA cPCR 结果，南美驼羊血传支原体的总检出率为 9.2%（8/87 [95%CI（4.0-17.3%）]），其中阳性羊驼 12.8%（5/39 [95%CI（4.3-27.4%）]），阳性美洲驼 6.3%（3/48 [95%CI（1.7-17.2%）]）。所有 16S rRNA PCR 阳性样本 rnpB 基因均为阴性。通过 BLASTn 分析，获得的 16S 序列与英国一只羊驼的“候选血支原体”具有高度同一性（99-100%）。16S rRNA 基因的系统发育和单倍型分析表明，本研究的“候选血支原体”序列与来自北美的“候选血支原体”序列高度相似，与欧洲和亚洲的“候选血支原体”序列高度相似，表明智利样本的多样性较低，仅检测到一个单倍型（#1）。智利南美驼羊的单倍型#1在全球范围内分布，在北美、欧洲和亚洲都有发现。本研究首次在智利的南美驼羊中检测到低多样性的“候选血支原体”，且分布广泛。
