Treviño-Rangel Rogelio de J, Bodden-Mendoza Byron A, Montoya Alexandra M, Villanueva-Lozano Hiram, Elizondo-Zertuche Mariana, Robledo-Leal Efrén, González Gloria M
Department of Microbiology, School of Medicine, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, Mexico.
Department of Microbiology and Immunology, School of Biological Sciences, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Nuevo León, Mexico.
Rev Iberoam Micol. 2018 Jan-Mar;35(1):17-21. doi: 10.1016/j.riam.2017.05.002. Epub 2017 Dec 26.
Candida tropicalis is an increasingly important human pathogen which usually affects neutropenic oncology patients with common hematogenous seeding to peripheral organs and high mortality rates. Candida pathogenicity is facilitated by several virulence attributes, including secretion of hydrolytic enzymes; however, little is known regarding the C. tropicalis ability to secrete them and their role in the disease.
To confirm by molecular means the identification of 187 clinical isolates (127 from blood, 52 from urine, and 8 from diverse clinical origins) phenotypically identified as C. tropicalis, and to investigate their in vitro aspartyl proteinase, phospholipase, esterase, hemolysin, DNase and coagulase activities.
The molecular confirmation was performed by ITS sequencing, and the enzymatic determinations were conducted using plate assays with specific substrates, with the exception of coagulase, which was determined by the classical tube test.
The majority of the strains exhibited a very strong or strong activity of aspartyl proteinase, phospholipase and esterase. A 4.7% of the bloodstream isolates were hemolysin producers, and all were negative for the coagulase and DNase assays.
Very strong activities of aspartyl proteinase, phospholipase and esterase profiles were detected, and a statistical association between phospholipase production and blood and urine isolates was found.
热带念珠菌是一种日益重要的人类病原体，通常影响中性粒细胞减少的肿瘤患者，常见血行播散至外周器官，死亡率高。念珠菌的致病性由多种毒力特性促成，包括水解酶的分泌；然而，关于热带念珠菌分泌这些酶的能力及其在疾病中的作用知之甚少。
通过分子手段确认187株临床分离株（127株来自血液，52株来自尿液，8株来自不同临床来源）的表型鉴定为热带念珠菌，并研究它们的体外天冬氨酸蛋白酶、磷脂酶、酯酶、溶血素、DNA酶和凝固酶活性。
通过ITS测序进行分子确认，除凝固酶采用经典试管试验测定外，酶活性测定采用含特定底物的平板试验。
大多数菌株表现出非常强或强的天冬氨酸蛋白酶、磷脂酶和酯酶活性。4.7%的血流分离株产生溶血素，所有菌株的凝固酶和DNA酶检测均为阴性。
检测到天冬氨酸蛋白酶、磷脂酶和酯酶的活性非常强，并且发现磷脂酶产生与血液和尿液分离株之间存在统计学关联。
