Abstract

Inaam M. N. Alrubayae, Ayat Al-laaeiby, Mohammed Hussein Minati, Shrouk A. H. ALibraheem

The incidence of yeast infections increased coinciding with the medical advancement and rising of the immunocompromised patient’s community. Few studies were conducted to identify the pathogenic agents that caused oral infections in the pediatric cancer patient in Iraq. This study was designed to identify pathogenic yeasts causing oral infections in the pediatric cancer patients and evaluate the genetic relationship among isolates by constructing the phylogenetic tree. The capacity of isolates to express two important virulence factors (biofilm formation and hydrolytic enzymes, proteinase and phospholipase) was investigated. To achieve these goals, 24 swab samples were obtained from patients and identified by both conventional and advance methods. The majority of isolates were Candida albicans, while Candida non-albicans was minor. The identified isolates of Candida non-albicans were classified as C. dubliniensis, C. glabrata, and C. tropical, in addition to Rhodotorula mucilaginosa, and Kluyveromyces marxianus respectively by analyzing the sequences of ITS regions. R. mucilaginosa was enrolled for the first time in Iraq by sequencing ITS region. The phylogenetic tree was constructed by Maximum Likelihood (ML) analyses, isolates were categories into five clusters comparing with reference strains and public database. The results found that the majority of isolates produced enzymes and formed biofilm strongly. In conclusion, identification of etiological agents employing comparison between ITS region sequence and public database was a simple, precise and accurate method.