The yeast, the antifungal, and the wardrobe: a journey into antifungal resistance mechanisms of Candida tropicalis

2020 ◽  
Vol 66 (6) ◽  
pp. 377-388
Author(s):  
Jonathas Sales de Oliveira ◽  
Vandbergue Santos Pereira ◽  
Débora de Souza Collares Maia Castelo-Branco ◽  
Rossana de Aguiar Cordeiro ◽  
José Júlio Costa Sidrim ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Intensive Care ◽  
Candida Tropicalis ◽  
Clinical Management ◽  
Candida Species ◽  
Genetic Basis ◽  
Antifungal Susceptibility ◽  
Resistance Mechanisms ◽  
Antifungal Resistance ◽  
Resistant Strains

Candida tropicalis is a prominent non-Candida albicans Candida species involved in cases of candidemia, mainly causing infections in patients in intensive care units and (or) those presenting neutropenia. In recent years, several studies have reported an increase in the recovery rates of azole-resistant C. tropicalis isolates. Understanding C. tropicalis resistance is of great importance, since resistant strains are implicated in persistent or recurrent and breakthrough infections. In this review, we address the main mechanisms underlying C. tropicalis resistance to the major antifungal classes used to treat candidiasis. The main genetic basis involved in C. tropicalis antifungal resistance is discussed. A better understanding of the epidemiology of resistant strains and the mechanisms involved in C. tropicalis resistance can help improve diagnosis and assessment of the antifungal susceptibility of this Candida species to improve clinical management.

scholarly journals Antifungal Resistance Pattern of Candida Species Isolated from High Vaginal Swabs of Women Attending a Hospital in Enugu State, Nigeria

2020 ◽  
pp. 62-72
Author(s):  
Joachim Ohiakwu Ezeadila ◽  
Ikechukwu Okoli ◽  
Christie Amaechi Oyeka
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Candida Tropicalis ◽  
Candida Species ◽  
Candida Glabrata ◽  
Candida Parapsilosis ◽  
Inhibition Zone ◽  
Candida Krusei ◽  
Antifungal Resistance ◽  
Resistance Pattern

There is an increase in non-albicans Candida (NAC) vulvovaginal candidiasis which is attributed to overuse of antifungal therapy and this has led to antifungal resistance. This study was aimed at determining the antifungal resistance pattern of some clinical isolates of Candida species. Eighty-eight (88) isolates were used which included Candida tropicalis (34), Candida Parapsilosis (21), Candida albicans (20), Candida krusei (7) and Candida glabrata (6). The drugs used were Fluconazole (25µg), Ketoconazole (10µg), Voriconazole (1µg), Nystatin (100Units), Amphotericin B (20µg), Flucytosine (1µg), Clotrimazole (10µg) and Itraconazole (50µg). The susceptibility testing was carried out using the M44-A standard method for yeast disk diffusion testing. Results showed that the percentages of Candida species resistant to Fluconazole, Ketoconazole, Voriconazole, Amphotericin B, Flucytosine, Clotrimazole and Itraconazole and Nystatin were 52.3%, 61.9%, 35.2%, 19.3%, 86.4%, 34.1%,  45.5% and 44.3%,  with inhibition zone diameters ≤14mm, ≤20mm, ≤13mm, <10mm, ≤11mm, ≤11mm, ≤13mm and no inhibition zone diameter respectively. Candida krusei was the most resistant species with 100% resistance to each of Fluconazole, Ketoconazole and Flucytosine. Candida tropicalis was the species with the highest susceptibility (79.4%) to Amphotericin B followed by Candida parapsilosis with inhibition zone diameters ≥15mm. While Candida glabrata showed 100% resistance to each of Flucytosine and Itraconazole, Candida albicans showed 100% resistance to Flucytosine only. Candida glabrata was the only Candida species with 0% resistance to Amphotericin B. The drug to which most of the Candida species were susceptible was Amphotericin B followed by Voriconazole while Flucytosine was the drug with the highest resistance followed by Ketoconazole and Fluconazole. The highest number of susceptible-dose dependent Candida isolates was observed with Ketoconazole (25%), followed by Clotrimazole and Itraconazole, each recording 23.9%. Based on the findings of the present study, Voriconazole is recommended for vaginal candidiasis especially in the study area and also especially for infections caused by Fluconazole-resistant Candida species. This suggests that routine sensitivity testing is pertinent to guiding the choice of antifungal therapy. Thus, indiscriminate use of antifungal drugs should be avoided to reduce the development and spread of resistance.

scholarly journals Changing Trends of Candida Species and Antifungal Susceptibility Profile of Candida Bloodstream Isolates: A 5-Year Retrospective Survey

2022 ◽  
Vol 14 (12) ◽  
Author(s):  
Ahmet Cem Yardimci ◽  
Dilek Arman
Keyword(s):  
Candida Albicans ◽  
Candida Species ◽  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Bloodstream Infections ◽  
Antifungal Resistance ◽  
Hemopoietic Stem Cell ◽  
Candida Spp ◽  
Study Results ◽  
Significant Difference

Background: Candida species have emerged as one of the most common causes of bloodstream infections (BSIs). There are limited data on the distribution of Candida spp. and susceptibility by year. Objectives: In this study, we analyzed changes in the distribution of Candida spp. and their antifungal susceptibility profiles from blood cultures. Methods: Records from January 2016 to December 2020 were obtained from the microbiology laboratory in Istanbul. Antifungal susceptibility tests were performed using the VITEK 2 compact system and evaluated according to EUCAST breakpoints. A total of 241 unique candidemia episodes were included in this study. Results: Candida albicans was the predominant pathogen (n = 95, 39.42%), followed by C. parapsilosis (n = 82, 34.02%), C. glabrata (n = 18, 7.47%), C. tropicalis (n = 17, 7.05%), C. krusei (n = 15, 6.22%), and other Candida spp. (n = 14, 5.79%). There was no statistically significant difference in the percentage of episodes of Candida spp. After data analysis, a tendency to shift from C. albicans to C. parapsilosis was observed in the period analyzed in this study. Candida albicans was the most common species in intensive care units (ICUs), hematology and hemopoietic stem cell transplantation units, and surgical clinics, with C. parapsilosis predominant in medical clinics. In general, micafungin susceptibility was the highest, and fluconazole was the lowest. There was reduced sensitivity to fluconazole and voriconazole for C. albicans and C. parapsilosis over 5 years. Conclusions: Detecting changes in the distribution of Candida spp. and antifungal susceptibility over time will lead to the selection of appropriate empirical therapy and monitor phenomena of antifungal resistance. Empirical treatment with antifungal agents is associated with high costs, toxicities, and risk of antifungal resistance. Therefore, it is mandatory to determine and monitor Candida spp. and antifungal susceptibility testing to select appropriate antifungal agents.

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

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..

scholarly journals Synergistic Antifungal Activity of Chitosan with Fluconazole against Candida albicans, Candida tropicalis, and Fluconazole-Resistant Strains

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5114
Author(s):  
Wei-Hsuan Lo ◽  
Fu-Sheng Deng ◽  
Chih-Jung Chang ◽  
Ching-Hsuan Lin
Keyword(s):  
Candida Albicans ◽  
Antifungal Activity ◽  
Candida Tropicalis ◽  
Inhibitory Effect ◽  
Antifungal Drugs ◽  
Drug Resistant ◽  
Combinational Treatment ◽  
Fluconazole Resistant ◽  
Resistant Strains ◽  
Drug Resistant Strains

(1) Background: Few antifungal drugs are currently available, and drug-resistant strains have rapidly emerged. Thus, the aim of this study is to evaluate the effectiveness of the antifungal activity from a combinational treatment of chitosan with a clinical antifungal drug on Candida albicans and Candida tropicalis. (2) Methods: Minimum inhibitory concentration (MIC) tests, checkerboard assays, and disc assays were employed to determine the inhibitory effect of chitosan with or without other antifungal drugs on C. albicans and C. tropicalis. (3) Results: Treatment with chitosan in combination with fluconazole showed a great synergistic fungicidal effect against C. albicans and C. tropicalis, but an indifferent effect on antifungal activity when challenged with chitosan-amphotericin B or chitosan-caspofungin simultaneously. Furthermore, the combination of chitosan and fluconazole was effective against drug-resistant strains. (4) Conclusions: These findings provide strong evidence that chitosan in combination with fluconazole is a promising therapy against two Candida species and its drug-resistant strains.

scholarly journals Prevalence and Antifungal Susceptibility of Candida albicans Causing Vaginal discharge Among Pregnant Women in Lebanon

2019 ◽  
Author(s):  
Nahed Ghaddar ◽  
Elie Anastasiadis ◽  
Rawad Halimeh ◽  
Ali Ghaddar ◽  
Rita Dhar ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Pregnant Women ◽  
Candida Species ◽  
Vaginal Discharge ◽  
Antifungal Susceptibility ◽  
Test Method ◽  
Neonatal Outcomes ◽  
Vaginal Candidiasis ◽  
Adverse Neonatal Outcomes ◽  
Susceptibility Tests

Abstract Background: Vaginal candidiasis is frequently prevalent in pregnant women and is associated with sepsis and adverse neonatal outcomes. This study determined the presence of Candida species in symptomatic pregnant women and evaluated the antifungal susceptibility profile of the isolated strains. It also aimed to explore whether Candida species predicts gestational complications and adverse neonatal outcomes. Methods: A total of 258 pregnant women at 35 to 37 week of gestation participated in this study. Vaginal swabs from these patients were collected at various obstetrics and gynecology clinics in Lebanon for a period of 12 months. Candida isolates were identified at species level and antifungal susceptibility of Candida albicans to fluconazole (FCZ), amphotericin B (AMB), itraconazole (ICZ) and voriconazole (VCZ) was determined by the agar-based E-test method. Results: Among 258 women tested, 100 (39%) were positive for Candida species. C. albicans, C. glabrata and C. krusei were isolated from 42%, 41% and 17% of the women, respectively. C. albicans had significant positive associations with gestational diabetes while C. kreusi or C. glabrata had significant positive associations with gestational complications and vaginal discharge. The antifungal susceptibility tests of C. albicans isolates revealed 97.5%, 90%, 87.5% and 97.5% susceptibility to AMB, FCZ, ICZ and VCZ, respectively. Conclusion: The current study revealed high incidence of both C. albicans and non-C. albicans strains causing vulvovaginitis among pregnant women in Beirut, Lebanon. Whereas the susceptibility rates of C. albicans against AMB and VCZ were high, FCZ and ICZ proved comparatively less efficacious. The resistance profile of circulating C. albicans among pregnant women can predict the best outcome of appropriate prophylaxis or treatment of neonatal candidiasis. Vaginal candida colonization might lead to adverse neonatal outcome or gestational complications thus Candida screening as antennal follow up is advised.

scholarly journals Prevalence and Antifungal Susceptibility Pattern of Candida species Isolated from Patients with Urinary Tract Infections

2021 ◽  
Vol 7 (4) ◽  
pp. 328-335
Author(s):  
IA Lawal ◽  
OA Osinupebi ◽  
OV Adeosun
Keyword(s):  
Candida Albicans ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Candida Species ◽  
Antifungal Susceptibility ◽  
Diffusion Method ◽  
Susceptibility Pattern ◽  
Agar Disc ◽  
Sensitivity Pattern ◽  
Tract Infections

Background: The presence of Candida species in the urine is termed candiduria, and it is a common form of urinary tract infection (UTI). Many other species of Candida organism apart from Candida albicans are known with increasing the occurrence of resistance to available antifungal agents. Objectives: To determine the prevalence and sensitivity pattern of Candida isolates obtained from urine samples of diagnosed urinary tract infections. Methods: Midstream urine of patients attending the Lagos University Teaching Hospital, Ikeja Lagos, were collected and inoculated on Sabouraud Dextrose Agar (SDA). Microbiological processing was done with Gram reaction, germ tube test, CHROME agar TM and sugar fermentation test using API 32C system. Antifungal susceptibility tests were done using the agar disc diffusion method. Results: Candida species were obtained from 36 (12.9%) of 280 patients with UTI. Candida albicans (CA) had the highest frequency (12; 33.3%) compared to 24 (66.7%) for Non-albicans Candida (NAC). The speciation of Candida using Chrome Agar showed some misidentification from the API32C identification, but there was a significant correlation between API32C and Chrome Agar methods (r = 0. 9793). Half of the C. albicans species were sensitive to fluconazole while C. hellenica was only sensitive to Nystatin. The C. parapsilopsis had the highest susceptibility pattern, with 86% and 71% for fluconazole and ketoconazole, respectively. Generally, ketoconazole had the highest effectiveness on Candida species. Conclusion: This study demonstrated the role of Candida species in UTIs and their high susceptibility to ketoconazole.

scholarly journals Candida Species and Antifungal Susceptibility Isolated in Intensive Care Units: A Three-year Study

2021 ◽  
Vol 28 (3) ◽  
pp. 459-465
Author(s):  
Sule Batcık ◽  
İlkay Bahçeci ◽  
Leyla Kazancioglu ◽  
Hizir Kazdal ◽  
Mustafa Özcan
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Candida Species ◽  
Antifungal Susceptibility

scholarly journals Epidemiology and Molecular Characterizations of Azole Resistance in Clinical and Environmental Aspergillus fumigatus Isolates from China

2016 ◽  
Vol 60 (10) ◽  
pp. 5878-5884 ◽  
Author(s):  
Yong Chen ◽  
Zhongyi Lu ◽  
Jingjun Zhao ◽  
Ziying Zou ◽  
Yanwen Gong ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Antifungal Susceptibility ◽  
Public Health Problem ◽  
Wide Distribution ◽  
Resistance Mechanisms ◽  
Azole Resistance ◽  
Common Mutation ◽  
Content Type ◽  
Environmental Resistance ◽  
Resistant Strains

ABSTRACTAzole resistance inAspergillus fumigatushas emerged as a worldwide public health problem. We sought here to demonstrate the occurrence and characteristics of azole resistance inA. fumigatusfrom different parts of China. A total of 317 clinical and 144 environmentalA. fumigatusisolates from 12 provinces were collected and subjected to screening for azole resistance. Antifungal susceptibility,cyp51Agene sequencing, and genotyping were carried out for all suspected azole-resistant isolates and a subset of azole-susceptible isolates. As a result, 8 (2.5%) clinical and 2 (1.4%) environmentalA. fumigatusisolates were identified as azole resistant. Five azole-resistant strains exhibit the TR34/L98H mutation, whereas four carry the TR34/L98H/S297T/F495I mutation in thecyp51Agene. Genetic typing and phylogenetic analysis showed that there was a worldwide clonal expansion of the TR34/L98H isolates, while the TR34/L98H/S297T/F495I isolates from China harbored a distinct genetic background with resistant isolates from other countries. High polymorphisms existed in thecyp51Agene that produced amino acid changes among azole-susceptibleA. fumigatusisolates, with N248K being the most common mutation. These data suggest that the wide distribution of azole-resistantA. fumigatusmight be attributed to the environmental resistance mechanisms in China.

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