Molecular identification, biofilm formation and antifungal susceptibility of Rhodotorula spp.

Background. Vulvovaginal candidiasis caused by Candida species is a prevalent fungal infection among women. It is believed that the pathogenesis of Candida species is linked with the production of biofilm which is considered a virulence factor for this organism. The aim of this study was molecular identification, antifungal susceptibility, biomass quantification of biofilm, and detection of virulence markers of Candida species. Methods. We investigated the molecular identification of 70 vaginal isolates of Candida species, antifungal resistance to amphotericin B, fluconazole, itraconazole, and voriconazole according to CLSI M27-A3 and M27-S4, biofilm formation, and frequency analysis of biofilm-related ALS1, ALS3, and HWP1 genes. Results. Our findings showed that the most common yeast isolated from vaginal discharge was C. albicans (67%), followed by the non-Candida albicans species (33%). All C. albicans complex isolates were confirmed as C. albicans by HWP-PCR, and all isolates of the C. glabrata complex were revealed to be C. glabrata sensu stricto using the multiplex PCR method. FLC resistance was observed in 23.4% of C. albicans and 7.7% of C. glabrata. The resistance rate to ITC was found in 10.6% of C. albicans. The frequency of ALS1, ALS3, and HWP1 genes among Candida species was 67.1%, 80%, and 81.4%, respectively. Biofilm formation was observed in 54.3% of Candida species, and the highest frequency detected as a virulence factor was for the ALS3 gene (97.3%) in biofilm-forming species. Discussion. Our results showed the importance of molecular epidemiology studies, investigating antifungal susceptibility profiles, and understanding the role of biofilm-related virulence markers in the pathogenesis of Candida strains.

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Molecular diagnosis and antifungal resistance and biofilm production profiles among Candida species isolated from immunocompromised patients at Menoufia University Hospitals

10.51429/ejmm29305 ◽

2020 ◽

Vol 29 (3) ◽

pp. 37-45

Author(s):

Mabrouk M Ghonaim ◽

Azza Z. Labeeb ◽

Alyaa I. Eliwa ◽

Eman H. Salem

Keyword(s):

Candida Species ◽

Biofilm Formation ◽

Antifungal Susceptibility ◽

High Sensitivity ◽

Antifungal Resistance ◽

Common Source ◽

Immunocompromised Patients ◽

University Hospitals ◽

Biofilm Production ◽

Vitek 2

Background: Accurate and rapid identification of Candida species is necessary for proper diagnosis and treatment of candidiasis due to emergences of drug-resistant strains especially among immunocompromised patients. Objectives: Identification of Candida clinical isolates to the species level using different phenotypic and molecular methods. Biofilm-forming ability and antifungal resistance were also studied. Methodology: Sixty-nine Candida strains were isolated from 220 immunocompromised patients. Identification was performed using chromogenic Candida agar, VITEK 2 system and multiplex polymerase chain reaction (PCR). Biofilm formation was detected by the tube method and antifungal susceptibility was tested using the VITEK2 system. Results: The most common source of Candida isolates was from urine (33.3%) and ICUs (56.6%). VITEK 2 system detected 9 spp.: C. albicans (34.8%), C. tropicalis (21.7%), C. famata (8.7%), C. lusitaniae (7.2%), C. cruzi (7.2%), C. ciferri (5.8%), C. dubliniensis (5.8%), C. parapsilosis (5.8 %) and C. glabrata. Candida isolates showed high resistance to flucytocine (49.3%), and high sensitivity to fluconazole, micafungin, voriconazole and caspofungin (88.4%, 81.2% and 81.2 % respectively). Only 30.4% of all Candida isolates were biofilm producers. There was a positive relationship between antifungal resistance and biofilm formation among Candida isolates. Conclusion: C. albicans was the predominant species. Chromogenic Candida agar and VITEK 2 system were valuable tests compared to PCR in speciation of Candida isolates. Antifungal susceptibility was significantly related to biofilm production and its evaluation is important for proper treatment..

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Biofilm Formation by and Antifungal Susceptibility of Candida Isolates from Urine

Applied and Environmental Microbiology ◽

10.1128/aem.02439-06 ◽

2007 ◽

Vol 73 (6) ◽

pp. 1697-1703 ◽

Cited By ~ 86

Author(s):

N. Jain ◽

R. Kohli ◽

E. Cook ◽

P. Gialanella ◽

T. Chang ◽

...

Keyword(s):

Risk Factors ◽

Growth Medium ◽

Biofilm Formation ◽

Chart Review ◽

Antifungal Susceptibility ◽

Retrospective Chart Review ◽

Urine Samples ◽

Rpmi Medium

ABSTRACT Biofilm formation (BF) in the setting of candiduria has not been well studied. We determined BF and MIC to antifungals in Candida spp. isolates grown from urine samples of patients and performed a retrospective chart review to examine the correlation with risk factors. A total of 67 Candida spp. isolates were grown from urine samples from 55 patients. The species distribution was C. albicans (54%), C. glabrata (36%), and C. tropicalis (10%). BF varied greatly among individual Candida isolates but was stable in sequential isolates during chronic infection. BF also depended on the growth medium and especially in C. albicans was significantly enhanced in artificial urine (AU) compared to RPMI medium. In nine of the C. albicans strains BF was 4- to 10-fold higher in AU, whereas in three of the C. albicans strains and two of the C. glabrata strains higher BF was measured in RPMI medium than in AU. Determination of the MICs showed that planktonic cells of all strains were susceptible to amphotericin B (AMB) and caspofungin (CASPO) and that three of the C. glabrata strains and two of the C. albicans strains were resistant to fluconazole (FLU). In contrast, all biofilm-associated adherent cells were resistant to CASPO and FLU. The biofilms of 14 strains (28%) were sensitive to AMB (MIC50 of <1 μg/ml). Correlation between degree of BF and MIC of AMB was not seen in RPMI grown biofilms but was present when grown in AU. A retrospective chart review demonstrated no correlation of known risk factors of candiduria with BF in AU or RPMI. We conclude that BF is a stable characteristic of Candida strains that varies greatly among clinical strains and is dependent on the growth medium. Resistance to AMB is associated with higher BF in AU, which may represent the more physiologic medium to test BF. Future studies should address whether in vitro BF can predict treatment failure in vivo.

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Molecular identification and antifungal susceptibility of clinical fungal isolates from onychomycosis (uncommon and emerging species)

Mycoses ◽

10.1111/myc.12854 ◽

2018 ◽

Vol 62 (2) ◽

pp. 128-143 ◽

Cited By ~ 5

Author(s):

Iman Haghani ◽

Masoomeh Shams-Ghahfarokhi ◽

Abdolhossein Dalimi Asl ◽

Tahereh Shokohi ◽

Mohammad Taghi Hedayati

Keyword(s):

Molecular Identification ◽

Antifungal Susceptibility ◽

Fungal Isolates

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Molecular identification and antifungal susceptibility among clinical isolates of dermatophytes in Shiraz, Iran (2017‐2019)

Mycoses ◽

10.1111/myc.13226 ◽

2020 ◽

Author(s):

Zahra Zareshahrabadi ◽

Alireza Totonchi ◽

Ali Rezaei‐Matehkolaei ◽

Macit Ilkit ◽

Mehdi Ghahartars ◽

...

Keyword(s):

Molecular Identification ◽

Antifungal Susceptibility ◽

Clinical Isolates

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Molecular Identification and In Vitro Antifungal Susceptibility of Aspergillus Isolates Recovered from Otomycosis Patients in Western China

Mycopathologia ◽

10.1007/s11046-020-00448-7 ◽

2020 ◽

Vol 185 (3) ◽

pp. 527-535

Author(s):

LiLi Zhang ◽

Xiaodong Wang ◽

Jos Houbraken ◽

Huan Mei ◽

Wanqing Liao ◽

...

Keyword(s):

Molecular Identification ◽

Antifungal Susceptibility ◽

Western China ◽

In Vitro Antifungal Susceptibility

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Virulence Factors Contributing to Pathogenicity ofCandida tropicalisand Its Antifungal Susceptibility Profile

International Journal of Microbiology ◽

10.1155/2014/456878 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 55

Author(s):

Sachin C. Deorukhkar ◽

Santosh Saini ◽

Stephen Mathew

Keyword(s):

Virulence Factors ◽

Biofilm Formation ◽

Antifungal Susceptibility ◽

Common Species ◽

Blood Cultures ◽

Haemolytic Activity ◽

Phospholipase Activity ◽

Fluconazole Resistance ◽

Activity Maximum ◽

The Past

The incidence of invasive candidiasis has increased over the past few decades. AlthoughCandida albicansremains by far the most common species encountered, in recent years shift towards non-albicans Candidaspecies likeCandida tropicalisis noted. Here in this study we determined the virulence factors and antifungal susceptibility profile of 125C. tropicalisisolated from various clinical specimens. Biofilm formation was seen in 53 (42.4%) isolates. Coagulase production was noted in 18 (14.4%) isolates. Phospholipase enzyme was the major virulent factor produced byC. tropicalisisolates. A total of 39 biofilm forming isolates showed phospholipase activity. Proteinase activity was demonstrated by 65 (52%) isolates. A total of 38 (30.4%) isolates showed haemolytic activity. Maximum isolates demonstrated resistance to fluconazole. Fluconazole resistance was more common inC. tropicalisisolated from blood cultures. Antifungal resistance was more in isolates possessing the ability to produce phospholipase and biofilm.C. tropicalisexhibit a great degree of variation not only in their pathogenicity but also in their antifungal susceptibility profile. The identification of virulence attributes specific for each species and their correlation with each other will aid in the understanding of the pathogenesis of infection.

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In vitro antifungal susceptibility of candidemia agents and detection of their biofilm production by two different methods

Microbiology Research ◽

10.4081/mr.2017.6916 ◽

2017 ◽

Vol 8 (1) ◽

Author(s):

Yasemin Oz ◽

Iman Qoraan ◽

Egemen Gokbolat

Keyword(s):

Production Rate ◽

Biofilm Formation ◽

Colorimetric Assay ◽

Formation Rate ◽

Antifungal Susceptibility ◽

Reference Method ◽

Antifungal Resistance ◽

Detection Methods ◽

Biofilm Production

Candida bloodstream infections are a significant cause of morbidity and mortality in hospitalized patients. The most important contribution of biofilm is the higher antifungal resistance than planktonic cells. We aimed to investigate the biofilm formation rate and antifungal susceptibility characteristics of our bloodstream isolates, and evaluate two different biofilm detection methods. A total of 200 bloodstream Candida isolates were included. The biofilms were formed on 96-well microtiter plates and measured by spectrophotometric percent transmittance and 2,3-bis(2- methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium- 5-carboxanilide colorimetric assay. In addition antifungal susceptibilities of these isolates were evaluated against caspofungin, anidulafungin and amphotericin B by reference method. Biofilm production rate was considerably high among our bloodstream isolates. The most important biofilm producer species was C. tropicalis; C. glabrata had the lowest biofilm production rate. The consistency rate between biofilm detection methods was 66%. Remarkable antifungal resistance was not observed among our isolates in general. In conclusion, biofilm production in Candida species is an important virulence factor, and its rate is considerably high in bloodstream isolates. At present, a standardized method has not been established to detect the biofilm formation.

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