Epidemiology of yeast species causing bloodstream infection in Tehran, Iran (2015–2017); superiority of 21-plex PCR over the Vitek 2 system for yeast identification

Abstract

Introduction. Given the limited number of candidaemia studies in Iran, the profile of yeast species causing bloodstream infections (BSIs), especially in adults, remains limited. Although biochemical assays are widely used in developing countries, they produce erroneous results, especially for rare yeast species. Aim. We aimed to assess the profile of yeast species causing BSIs and to compare the accuracy of the Vitek 2 system and 21-plex PCR. Methodology. Yeast blood isolates were retrospectively collected from patients recruited from two tertiary care training hospitals in Tehran from 2015 to 2017. Relevant clinical data were mined. Identification was performed by automated Vitek 2, 21-plex PCR and sequencing of the internal transcribed spacer region (ITS1-5.8S-ITS2). Results. In total, 137 yeast isolates were recovered from 107 patients. The overall all-cause 30-day mortality rate was 47.7 %. Fluconazole was the most widely used systemic antifungal. Candida albicans (58/137, 42.3 %), Candida glabrata (30/137, 21.9 %), Candida parapsilosis sensu stricto (23/137, 16.8 %), Candida tropicalis (10/137, 7.3 %) and Pichia kudriavzevii ( Candida krusei ) (4/137, 2.9 %) constituted almost 90 % of the isolates and 10 % of the species detected were rare yeast species (12/137; 8.7 %). The 21-plex PCR method correctly identified 97.1 % of the isolates, a higher percentage than the Vitek 2 showed (87.6 %). Conclusion. C. albicans was the main cause of yeast-derived fungaemia in this study. Future prospective studies are warranted to closely monitor the epidemiological landscape of yeast species causing BSIs in Iran. The superiority of 21-plex PCR over automated Vitek 2 indicates its potential clinical utility as an alternative identification tool use in developing countries.

A High Rate of Recurrent Vulvovaginal Candidiasis and Therapeutic Failure of Azole Derivatives Among Iranian Women

“…albicans constituted 79% of the isolates and was the most abundant Candida species responsible for VVC and RVVC. This observation is consistent with previous studies on VVC ( Sharifynia et al, 2017 ; Ghajari et al, 2018 ), oral candidiasis ( Arastehfar et al, 2019a ), and candidemia ( Arastehfar et al, 2020d ; Kord et al, 2020 ) in Iran, which documented the abundance of C. albicans among Iranian patients, whereas C . glabrata was reported the most prevalent Candida species among Indian patients ( Mohanty et al, 2007 ).…”

“…Although Candida albicans has been historically known as the most prevalent causative agent of fungal vulvovaginitis, new lines of evidence reveal an increasing incidence of non- albicans Candida (NAC) species, which generally respond to higher MICs of azoles ( Makanjuola et al, 2018 ) and which may contribute to complications associated with RVVC. Since the vast majority of RVVC cases are recorded in developing countries ( Denning et al, 2018 ), the shift toward NAC species could be problematic for their healthcare institutions, where the diagnosis and treatment of fungal infections are inadequate ( Arastehfar et al, 2019a , b , c , d ; Arastehfar et al, 2020d ; Kord et al, 2020 ; Megri et al, 2020 ).…”

Molecular Identification, And Antifungal Susceptibility Patterns of Candida Species Isolated From Candidemia Patients in Yasuj, Southwestern Iran

“…However, 40.7% of our patients were not treated with antifungal drugs. This result disagrees with other studies that reported uconazole was the most antifungal drug received in candidemia patients (21,22). The low mortality rate (14.8%) were obtained in our study was mostly lower than other reported in Iran (28-47%) (21,22).…”

“…This result disagrees with other studies that reported uconazole was the most antifungal drug received in candidemia patients (21,22). The low mortality rate (14.8%) were obtained in our study was mostly lower than other reported in Iran (28-47%) (21,22). It seems that this difference may due to different conditions of candidemia patients such as underlying disease, antifungal therapy, the type of Candida species, and the length of hospitalization.…”

Clonal Candidemia Outbreak by Candida parapsilosis Carrying Y132F in Turkey: Evolution of a Persisting Challenge

“…Drug exposure included the recorded data of the preceding six months and if needed records of the previous hospitalizations were checked. Thirty-day mortality was defined when death occurred ≤ 30 days after the first positive blood culture ( Kord et al., 2020 ). Candida parapsilosis blood isolates were inoculated onto Sabouraud glucose agar (Merck, Darmstadt, Germany) and chromogenic agar (Candi Select ™ 4, Bio-Rad, Hercules, CA, USA) plates and incubated at 37°C for 24–48 h. Species identification was performed using primers targeting internal transcribed spacer 1 (ITS1; TCCGTAGGTGAACCTGCGG) and ITS 4 (GCATATCAATAAGCGGA) ( Stielow et al., 2015 ).…”