Molecular identification of Candida species isolated from candiduria and its risk factors in neonates and children

Abstract

Background and purpose: The present study was performed to raise attention on the frequency of Candida spp. and evaluation of risk factors of candiduria in neonates and children.

Materials and methods: In total, 60 urine samples were collected from the suspected neonates and children. Identification of Candida at species level was performed using the polymerase chain reaction-restriction fragment length polymorphism approach.

Results: The restriction fragment length polymorphism fingerprint analysis revealed that Candida parapsilosis (n=17; 28.33 %) is the most prevalent isolated species followed by Candida albicans (n=9; 15%), Candida tropicalis (n=4; 9.52%), and C. glabrata (n=2; 4.76%). All of the C. albicans and C. parapsilosis complex strains were identified as C. albicans with HWP1 gene primers and using the NlaIII restriction enzyme activity, respectively. In this study, none of the mentioned factors was the cause of infection, but they could be considered risk factors. The mean hospital stay was 21 days (range: 7-21 days). More than 90% of the patients had a urinary catheter, and about 26% of them received antibiotics. Regarding the risk factors, there was no significant difference between the two groups of candidiasis in terms of C. albicans and non-albicans Candida (P<0.01).

Conclusion: Candiduria has always been a challenging issue, especially in children admitted to hospitals. Outcome of candiduria in patients with generally healthy is little.

Keywords: Candiduria; Children; Neonates; Risk factors; Candida species.

Figure 1

Agaros gel electrophoresis pattern of polymerase chain reaction products of Candida. a: before digestion with the restriction enzyme, lane 1-8: bands are all located between 524 and 871 bp which suggests that they possibly belonged to the Candida genus. b: enzymatic digestion pattern with MspI restriction enzyme for differentiation of Candida spp. a: C. albicans (297-238 bp): 1, 3; C. glabrata (314-557 bp): 2; C. tropicalis (184-340 bp):4; M: 100 bp DNA size marker.

Figure 2

Amplification pattern of HWP1 genes for identification of Candida albicans complex. L: 100 bp DNA size marker. The lanes in the picture belong to Candida albicans (900 bp).

Figure 3

Identification of Candida parapsilosis complex after digestion with NlaIII restriction enzyme. L: 100 bp DNA size marker. Lane 1. C. parapsilosis complex before digestion; lanes 1-6. C. parapsilosis spp.