Phylogenetic Diversity and Susceptibility of Candida Species from Women using Contraceptive Devices in Central Nigeria

Abstract

Purpose: The use of contraceptive devices predisposes women to vulvovaginal candidiasis globally. Despite the high incidence of vulvovaginal candidiasis and antifungal resistance to azoles, the ge- netic diversity and resistance pattern among contraceptive users in Nigeria is poorly investigated. This study therefore sought to char- acterize and determine the phylogenetic breadth of Candida spp. as well as their resistance to antifungal agents from women using contraceptive devices in central Nigeria. Methods & Materials: This study recruited 1,600 women using contraceptive devices that visited gynaecology and obstetrics clin- ics in central Nigeria between August, 2018 to February, 2020. Can- dida spp. were isolated and characterized using conventional meth- ods and the sequencing of the internal transcribed spacer (ITS) re- gion of the ribosomal DNA (rDNA). Bayesian phylogenetic analysis was used to characterize the diversity of Candida spp. Agar well diffusion technique and primer-specific PCR were used for the de- termination of antifungal susceptibility profiles and the presence of resistant genes. Results: Five Candida spp. were identified from 710 contracep- tive users with vulvovaginal candidiasis. Although Candida albi- cans was the predominant (43.23%) Candida spp. isolated, other non-albicans Candida spp. included C. glabrata (19.01%) C. tropi-calis (15.77%) C. parapsilosis (8.87%) and C. akabanensis (13.09%) re- spectively. The molecular characterization of the different Candida spp. and their phylogenetic relationships were confirmed using the Bayesian analysis. All the Candida spp. revealed varying degrees of susceptibilities to voriconazole, fluconazole and nystatin. How- ever, C. albicans showed 29.0% resistance to fluconazole, C. tropi- calis showed 46.0% and 14.0% resistance to nystatin and voricona- zole while C. akabanensis showed 100% resistance to voriconazole and fluconazole, respectively. Kruskal-Wallis Chi-square test using ‘R’ (Version 3.2.2) showed nystatin as the most effective antifungal agent (Kruskal-Wallis χ2 = 786.03, df = 2, P < 0.001) against Can- dida spp. Also, resistant gene Erg11 was identified in all the Candida spp. resistant to the antifungal agents tested. Conclusion: Women using contraceptive devices in central Nigeria harbour phylogenetically diverse Candida spp. including C. akabanensis an uncommon cause of vulvovaginal candidiasis. Out of these Candida spp. C. albicans, C. tropicalis and C. akabanensis are notable for multidrug drug resistance as well as harbouring re- sistant gene Erg11.