Department of Parasitology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Acta Parasitol. 2024 Mar;69(1):609-615. doi: 10.1007/s11686-024-00805-2. Epub 2024 Jan 29.
Acanthamoeba spp. can be found in natural and artificial environments, which reflects their high adaptability to different conditions. Based on the available data, there is scarce information about the isolation of amoeba from milk. This study aimed to investigate the probable presence of Acanthamoeba in milk used for calf feeding.
200 milk samples from 50 industrial and traditional farms were collected. The samples were filtered and cultured on the 1.5% Non-nutrient agar medium. The amoebic growth was examined with an inverted microscope daily. DNA was extracted from the positive plates, and a PCR reaction was undertaken using the primers amplifying the Acanthamoeba 18 S rRNA gene. Five samples were purified and sequenced using specific primers. Maximum likelihood reconstructions were performed using the phylogenetic program MEGA software. The osmo and thermotolerance of isolated trophozoites were examined as well.
Out of 200 milk samples, Acanthamoeba was isolated from 27 (13.5%). The phylogenetic tree represents that all the isolates belonged to the genotype T4. Results of thermo and osmotolerance tests showed that isolates could develop at 37 and 43 ◦C. Besides, trophozoites survived at 0.5 M mannitol and 1 M.
For the first time, Acanthamoeba spp. were isolated from milk used to feed dairy calves. Due to Acanthamoeba's neglected role in pathogen persistence and survival, hygiene instructions should be reconsidered.
棘阿米巴属可在自然和人工环境中被发现，这反映了它们对不同条件的高度适应性。根据现有数据，关于从牛奶中分离出阿米巴的信息很少。本研究旨在调查用于犊牛喂养的牛奶中可能存在的棘阿米巴。
采集了来自 50 个工业和传统农场的 200 份牛奶样本。对这些样本进行过滤并在 1.5%非营养琼脂培养基上培养。每天用倒置显微镜检查阿米巴的生长情况。从阳性平板中提取 DNA，使用扩增棘阿米巴 18S rRNA 基因的引物进行 PCR 反应。对 5 个样本进行纯化和测序，使用特定引物。使用系统发育程序 MEGA 软件进行最大似然重建。还检查了分离的滋养体的耐渗透压和耐热性。
在 200 份牛奶样本中，从 27 份（13.5%）中分离出棘阿米巴。系统发育树表明，所有分离株均属于基因型 T4。耐热和耐渗透压试验的结果表明，分离株可以在 37 和 43°C 下生长。此外，滋养体在 0.5M 甘露醇和 1M 下存活。
首次从用于喂养奶牛犊的牛奶中分离出棘阿米巴属。由于棘阿米巴在病原体存活和生存中的作用被忽视，因此应重新考虑卫生说明。
