Antifungal susceptibility testing and determination of local epidemiological cut-off values for Candida species isolated from women with vulvovaginal candidiasis.

Kroustali V ，Kanioura L ，Resoulai E ，Siopi M ，Antonopoulou S ，Meletiadis J ... -  《Microbiology Spectrum》

Epidemiology of Vulvovaginal Candidiasis in Greece: A 2-Year Single-Centre Study.

The epidemiology of vulvovaginal candidiasis (VVC) in Greece remains poorly reported and outdated. We therefore conducted a 2-year retrospective survey to assess the epidemiological aspects of the infection among symptomatic Greek patients. High vaginal swab samples were collected from adult women with clinically suspected VVC attending a private diagnostic laboratory in Athens. VVC was confirmed through microscopic examination of a wet mount preparation revealing yeasts and Candida-positive culture. Species were identified by MALDI-ToF MS, and in vitro susceptibility was determined according to the EUCAST-E.Def 7.4. Predisposing host factors were associated with the occurrence of the infection and isolated Candida spp. using Fisher's exact test, and epidemiological changes over time were analysed with the χ2 test for trend. Among 1300 women screened, 283 VVC episodes were recorded among 233 (18%) patients, whereof 11 (5%) had recurrent VVC (RVVC) and 19 (8%) had mixed Candida infections. Coinfection with other pathogens and recent prior use of antifungals were associated with RVVC. Candida albicans was the most prevalent pathogen (50%), followed by Candida parapsilosis sensu stricto (SS) (35%), Nakaseomyces glabratus (former Candida glabrata) (10%), Pichia kudriavzevii (former Candida krusei) (3%), Candida orthopsilosis (1.5%) and Clavispora lusitaniae (former Candida lusitaniae) (0.5%). Regarding the RVVC cases, 54% were attributed to C. albicans, 37% to N. glabratus and 9% to C. parapsilosis SS. Resistance to fluconazole was found in 4% of C. albicans and 23% of N. glabratus strains with cross-resistance to other azoles. Fluconazole-resistant isolates were recovered from 5 of 11 RVVC patients, whereof 4 of 5 had previous exposure to azoles. During the study period, an increase in N. glabratus VVC and fluconazole resistance was noted. VVC is common in our region, with C. albicans as the predominant species, followed by C. parapsilosis SS and N. glabratus. Fluconazole resistance is low in C. albicans but high in N. glabratus, emphasising the need for targeted antifungal strategies.

Kroustali V ，Resoulai E ，Kanioura L ，Siopi M ，Meletiadis J ，Antonopoulou S ... -  《-》

Vulvovaginal candidiasis, an increasing burden to women in the tropical regions attending Bharatpur Hospital, Chitwan.

Subedi A ，Upreti MK ，Rana JC ，Sapkota RP ，Thapa Shrestha U ... -  《-》

Increasing rate of non-Candida albicans yeasts and fluconazole resistance in yeast isolates from women with recurrent vulvovaginal candidiasis in Leeds, United Kingdom.

Azoles have been the mainstay of recurrent vulvovaginal candidiasis (RVVC) for many years. Because of a recent anecdotal increase in non-Candida albicans yeasts (NCAY) and azole-resistant C. albicans cases, their prevalence was calculated from cultures for yeasts in women with complicated/RVVC over 3 years. Retrospective data search of vaginal cultures from adult women in Leeds, UK between April 2018 and March 2021 was conducted. Samples with clinical details of complicated/RVVC had full yeast identification and antifungal susceptibility performed. Differences in prevalence between 12-month periods were determined using χ2 tests. Over the 3 years, cultures were performed on 5461 vaginal samples from women with clinical information indicating they had complicated/RVVC, RVVC, with 1828 (33.5%) growing yeasts.Over 85% of yeasts each year were C. albicans, however the proportion declined yearly with an increase in NCAY species. Nakaseomyces glabrata was the most frequent NCAY species isolated, increasing from 2.8% in 2018-19 to 6.8% in 2020-21. Total NCAY species increased from 6.0% in 2018-19 to 12.6% in 2020-21. Fluconazole-sensitive dose-dependant (SDD) and resistant isolates increased from 3.5% in 2018-19 to 7.7% in 2019-20 and 9.6% in 2020-21. Most resistance was in C. albicans and the majority of cases were seen in primary care. Most fluconazole non-sensitive isolates were either SDD or resistant to itraconazole (77% and 23%, respectively) and were intermediate or resistant to voriconazole (36.4% and 60%, respectively). There was a significant increase in the prevalence of NCAY and fluconazole-resistant C. albicans in complicated/RVVC cultures over these 3 years. Successful treatment of such cases can be very challenging. The exact reasons for this increase remain unclear but it follows a policy change that encouraged a clinical diagnosis and empirical treatment of vulvovaginal candidiasis, rather than fungal culture, in primary care.

Ratner JC ，Wilson J ，Roberts K ，Armitage C ，Barton RC ... -  《-》

Comparative evaluation of antifungal susceptibility testing methods of invasive Candida species and detection of FKS genes mutations in caspofungin intermediate and resistant isolates.

Fungal invasive infections caused by Candida species pose a substantial public health risk with limited therapeutic options. Antifungal susceptibility testing (AFST) is necessary to optimize the therapy. The study aimed to compare different AFST methods of Candida spp. and detect FKS gene mutations among caspofungin-intermediate and resistant isolates. A total of 60 non-replicative invasive Candida isolates recovered from various clinical samples were included. In-vitro AFST was carried out using the ATB FUNGUS 3, Vitek-2 AST-YS08, and E-test. Hotspot (HS) regions of FKS genes were sequenced for caspofungin-intermediate and resistant isolates. Candida albicans (58.3%) was the most predominant spp., followed by C. glabrata (28.3%). Based on the clinical breakpoints (CBPs), fluconazole resistance was found in C. albicans (45.7%), C. tropicalis (25%), and the C. parapsilosis isolate, while 35.3% of C. glabrata were susceptible dose-dependent (SDD). None of C. albicans, C. tropicalis, or C. parapsilosis isolates were resistant to voriconazole. Using the epidemiological cut-off values (ECVs) for amphotericin B, 6.7% of isolates were non-wild type (non-WT), including C. guilliermondii (50%), C. tropicalis (25%), and C. glabrata (11.8%), while all C. albicans, C. parapsilosis, and C. kefyr isolates were classified as wild-type (WT). ATB FUNGUS 3 and Vitek-2 had the highest categorical agreement (CA) (83.1%) for amphotericin B, while a lower concordance was detected with voriconazole (23.2%) and fluconazole (52.2%). For caspofungin, Vitek-2 and E-test had a CA of 89.8%. Eleven isolates (10 C. glabrata and one C. parapsilosis) exhibited resistance or intermediate susceptibility to caspofungin (MICs: 0.25‒>32 µg/ml). Molecular characterization of the FKS gene demonstrated that FKS1 mutations V47I, V52K, V56T, D57S, L62F, I71Y, I71Q in the HS1 region, and G7S, P11H mutations in the HS2 region were associated with increased caspofungin MIC values (16 µg/ml). Mutations at the HS1 of the FKS2 gene; K33V, W35K, and W35V; were associated with the highest caspofungin MICs of > 32 µg/ml. ATB FUNGUS 3 demonstrated acceptable performance for AFST, however, azole activity against Candida spp. should be interpreted carefully. Novel mutations within HS regions of FKS genes elucidated different levels of caspofungin resistance in C. glabrata and C. parapsilosis isolates.

ElFeky DS ，El-Wakil DM ，Mwafy MM ，Atia MMA ，Gohar NM ... -  《BMC INFECTIOUS DISEASES》