Molecular Identification of Kocuria Species Isolated from Pediatric Teaching Hospital in Sulaymaniyah, Iraq

Abstract

Abstract Background: Kocuria species is now increasingly being recognized as an emerging human pathogen, suggesting that this genus has mostly been neglected or misidentified. Objective: This study attempts to use molecular techniques to correctly identify Kocuria species isolated from inpatient children, and to compare between the identification results obtained from two methods: VITEK 2 and 16S rRNA gene sequencing. Materials and Methods: VITEK 2, an automated system, was used to identify clinical isolates. Isolates identified as Kocuria spp. were submitted to DNA extraction and polymerase chain reaction testing. A partial sequence of the 16S rRNA gene was constructed and compared to GenBank sequences of the 16S rRNA gene. To confirm the strains’ identity, a phylogenetic tree including all Kocuria species was constructed. Results: Three isolates of Kocuria spp. were identified; the first two isolates were confirmed as K. kristinae by VITEK 2, pairwise 16S rRNA sequencing, and phylogenetic tree. However, the third isolate was identified as K. rosea, contradicting the pairwise 16S rRNA sequencing and phylogenetic tree identification as K. turfanensis. Conclusion: It is crucial to utilize molecular techniques for correctly identifying Kocuria species. In this study, it is found that K. turfanensis emerges as a pathogenic species and the first known cause of meningitis in humans and K. kristinae is identified as the first known cause of pediatric urinary tract infections.