Halim Rohaya Abdul, Halim Hasseri, Hussain Rosnani Hanim Mohd, Aazmi Shafiq, Khan Naveed Ahmed, Siddiqui Ruqaiyyah, Anuar Tengku Shahrul
Centre for Medical Laboratory Technology Studies, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Selangor, Malaysia.
Faculty of Pharmacy, Universiti Teknologi MARA, Puncak Alam Campus, Selangor, Malaysia.
J Water Health. 2024 Dec;22(12):2289-2303. doi: 10.2166/wh.2024.162. Epub 2024 Dec 4.
Free-living amoebae of the genus are causative agents of keratitis and amoebic encephalitis. They are widely found in various ecological environments. Therefore, the present study brings results that can help to better understand the genotypes of the environmental isolates and their pathogenicity. This study procured 26 isolates from three recreational lakes in 2022. Polymerase chain reaction amplification was performed on positive samples. The thermotolerance, osmotolerance, and cytopathogenicity in human keratinocyte (HaCaT) cells of the samples were also evaluated. The phylogenetic analysis demonstrated that 12 isolates were of genotype T4, two (T9), six (T17), four (T8), and one each from T5 and T11. The thermo- and osmotolerance assays indicated that eight samples were potentially pathogenic. Two T4 and one T9 genotype also recorded 33-, 42-, and 133-kDa serine-type proteases, respectively. The HaCaT cell monolayer revealed that three T4 and one T9 samples achieved cytopathic effects within the 50-100% range, hence significantly cytotoxic. The lactate dehydrogenase secretion results demonstrated that three (T4) and one (T9) sample exhibited exceptional toxicity (over 40%) compared to the other samples. The responses of members with similar genotypes to pathogenicity indicator assays varied considerably, rendering correlation of pathogenicity with specific genotypes challenging.
属的自由生活阿米巴是角膜炎和阿米巴性脑炎的病原体。它们广泛存在于各种生态环境中。因此,本研究带来的结果有助于更好地了解环境分离株的基因型及其致病性。本研究在2022年从三个休闲湖泊中采集了26株分离株。对阳性样本进行聚合酶链反应扩增。还评估了样本在人角质形成细胞(HaCaT)中的耐热性、耐渗性和细胞致病性。系统发育分析表明,12株分离株为T4基因型,两株为T9基因型,六株为T17基因型,四株为T8基因型,T5和T11基因型各有一株。耐热性和耐渗性测定表明,八个样本具有潜在致病性。两个T4基因型和一个T9基因型样本还分别记录到了33 kDa、42 kDa和133 kDa的丝氨酸型蛋白酶。HaCaT细胞单层显示,三个T4基因型和一个T9基因型样本在50%-100%范围内产生了细胞病变效应,因此具有显著的细胞毒性。乳酸脱氢酶分泌结果表明,与其他样本相比,三个(T4基因型)和一个(T9基因型)样本表现出极高的毒性(超过40%)。具有相似基因型的成员对致病性指标检测的反应差异很大,使得致病性与特定基因型之间的关联具有挑战性。