Comparison between Phenotypic Methods and Seminested PCR for Candida Species Identification

2012 ◽  
Vol 21 (4) ◽  
pp. 11-20
Author(s):  
Enas Daef ◽  
Ahmed Moharram ◽  
Salwa Seif Eldin
2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Seyedeh Zahra Sadrossadati ◽  
Mohammad Ghahri ◽  
Abbas Ali Imani Fooladi ◽  
Shirin Sayyahfar ◽  
Sedigheh Beyraghi ◽  
...  

Background and Purpose: Candidemia is one of the most important fungal infections caused by Candida species. Infections and mortality caused by Candida species have been on a growing trend during the past two decades. The resistance of yeasts to antifungal drugs and their epidemiological issues have highlighted the importance of accurately distinguishing the yeasts at the species level. The technique applied for yeast identification should be fast enough to facilitate the imminent initiation of the appropriate therapy. Candidemia has not been studied comprehensively in Iran yet. Regarding this, the current study aimed to assess the epidemiology of candidemia at Tehran hospitals and compare the results with the previous findings. Materials and Methods: This study was conducted on 204 positive blood cultures obtained from 125 patients hospitalized in several hospitals located in Tehran, Iran, within a period of 13 months. The yeast isolation and species identification were accomplished using several phenotypic methods (i.e., production of germ tube in human serum, culture on CHROMagar Candida, and Corn meal agar containing Tween 80) and molecular methods, such as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, unknown cases were subjected to PCR sequencing. These methods were then compared in terms of accuracy, sensitivity, and speed of identification. Results: According to the results, C. albicans (62.4%) was the most common isolate, followed by C. parapsilosis (n=36, 17.5%), C. glabrata (n=18, 8.8%), C. tropicalis (n=13, 6.3%), Trichosporon asahii (n=3, 1.5%), C. kefyr (n=2, 1.0%), C. lusitaniae (n=2, 1.0%), C. intermedia (n=1, 0.5%), C. guilliermondii (n=1, 0.5%), and C. krusei (n=1, 0.5%), respectively. Conclusion: As the findings indicated, the most common species causing candidemia were C. albicans, C. parapsilosis, and C. glabrata, respectively. Children less than one year old and people with cancer were at higher risk for candidemia, compared to other groups. Moreover, phenotypic and molecular methods resulted in the identification of 65.2% and 96.6% of the isolates, respectively. Consequently, PCR-RFLP could be concluded as a more favorable technique for species identification. Keywords: Candidemia, Blood culture, Epidemiology, PCR-RFLP


RSC Advances ◽  
2016 ◽  
Vol 6 (94) ◽  
pp. 92065-92072 ◽  
Author(s):  
Sónia Silva ◽  
Flávia Tobaldini-Valerio ◽  
Sofia Costa-de-Oliveira ◽  
Mariana Henriques ◽  
Joana Azeredo ◽  
...  

Accurate Candida species identification remains a challenge due to their phenotypic and genotypic similarity.


2015 ◽  
Vol 10 (7) ◽  
pp. 1133-1144 ◽  
Author(s):  
Sara Pinar Bilir ◽  
Cheryl P Ferrufino ◽  
Michael A Pfaller ◽  
Julie Munakata

2012 ◽  
Vol 50 (No. 12) ◽  
pp. 543-547 ◽  
Author(s):  
I. Kolackova ◽  
R. Karpiskova

The aim of this study was to compare the phenotypic and genotypic based methods for species identification of thermotolerant campylobacters of human and food origin from the Czech Republic. Phenotypic methods are time-consuming and sometimes lead to intermediate results, therefore replacement by more specific and rapid methods are needed. Out of a total of 911 campylobacter strains tested, 800 human isolates were received from the clinical bacteriology laboratories from 5 regions and 111 foodstuff isolates (raw chicken and pork meat from retail market) originated from the routine examination in our laboratory. Based on the PCR method 85.1% of these strains were identified as C. jejuni, 12.5% as C. coli and 2.3% as mixed cultures of C. jejuni and C. coli. When species determination of campylobacters was based on conventional methods (hippurate hydrolysis test), 28.5% of the isolates were not identified correctly. The mixed cultures of campylobacters have not been detected without further subculturing of strains, which takes several days and enormously extends the identification process. The use of the PCR method showed to be a useful tool for species identification of Campylobacter spp.


2021 ◽  
Vol 10 (4) ◽  
pp. e59810414462
Author(s):  
Cicero Pinheiro Inácio ◽  
Fernanda Gomes Beserra ◽  
Cynthia Regina Pedrosa Soares ◽  
Luciana Maria Delgado Romaguera ◽  
Paulo Sergio Ramos de Araújo ◽  
...  

Trends in epidemiology and antifungal susceptibility of Candida species in Brazil between 2019–2020 are reported. A total of 22 isolates diagnosed from candidemia episodes were analyzed. Candida species were identified by specie specific primer and/or sequencing of 28S rDNA. Antifungal susceptibility was determined by CLSI method. C. tropicalis accounted for 11 (50%) cases followed by C. albicans (n=5, 22.73%), C. parapsilosis (n=4, 18.19%), Issatchenkia orientalis (n= 1, 4.54%), and Saccharomyces cerevisiae (n= 1, 4.54%). All Candida isolates were susceptible to amphotericin B and micafungin, and one was dose-dependent to anidulafungin. Eight of 20 Candida isolates were resistant to fluconazole and four sensitive doses dependent. Sixteen of 20 Candida isolates were resistant to voriconazole, and one resistant and one sensitive dose-dependent on caspofungin. Besides, the respective MIC50 and MIC90 values ​​were calculated with fluconazole (MIC50 and MIC90 of 4 and 64µg/mL, respectively) and voriconazole (MIC50 and MIC90 of 16µg/mL) showing the lowest potencies. The spread of fluconazole-resistant in one of major concerns, especially to C. tropicalis. The high use of antifungal drug may be a possible cause related to this scenario. Thus, the susceptibility profile test may be used to know the best way to introduce appropriateness empirical antibiotics therapy. Changing trends in incidence and antifungal susceptibility patterns of six Candida species causing candidemia in Kuwait between 2006–2017 are reported. A total of 2075 isolates obtained from 1448 patients were analyzed. Identity of Candida species isolates was determined by phenotypic methods and confirmed by PCR amplification/PCR-sequencing of rDNA and/or MALDI-TOF MS. Antifungal susceptibility was determined by Etest. C. albicans accounted for 539 (37.22%) cases followed by C. parapsilosis (n = 502, 34.67%), C. tropicalis (n = 210, 14.5%), C. glabrata (n = 148, 10.22%), C. krusei (n = 27, 1.81%) and C. dubliniensis (n = 22, 1.5%). The comparative percent distribution of Candida species causing candidemia between 2006–2011 and 2012–2017 was as follows: C. albicans 41.8% and 33.1%, C. parapsilosis complex 32.01% and 37.04%, C. tropicalis 13.59% and 15.31%, and C. glabrata 8.77% and 11.51%, C. krusei 2.0% and 1.7%, and C. dubliniensis 1.75 and 1.3%, respectively. Three of 371 C. albicans isolates during 2006–2011 and five of 363 during 2012–2017 were resistant to fluconazole. Among C. parapsilosis isolates, one of 310 during 2006–2011 and 21 of 446 during 2012–2017 were resistant to this drug. Furthermore, at an epidemiologic cutoff value (ECV) of ≤0.5 μg/ml, 70.1% C. albicans isolates were wild-type for fluconazole during 2006–2011 as compared to 58.1% during 2012–2017. Likewise, at an ECV of ≤2 μg/ml, 98.0% of C. parapsilosis isolates were wild-type during 2006–2011 as compared to 93.4% during 2012–2017. Clonal spread of fluconazole-resistant C. parapsilosis in one major hospital was documented. An 8.8% shift in favor of non-albicans Candida species with concomitant increase in MICs between the two periods preludes emergence of fluconazole-resistant candidemia cases in Kuwait.Changing trends in incidence and antifungal susceptibility patterns of six Candida species causing candidemia in Kuwait between 2006–2017 are reported. A total of 2075 isolates obtained from 1448 patients were analyzed. Identity of Candida species isolates was determined by phenotypic methods and confirmed by PCR amplification/PCR-sequencing of rDNA and/or MALDI-TOF MS. Antifungal susceptibility was determined by Etest. C. albicans accounted for 539 (37.22%) cases followed by C. parapsilosis (n = 502, 34.67%), C. tropicalis (n = 210, 14.5%), C. glabrata (n = 148, 10.22%), C. krusei (n = 27, 1.81%) and C. dubliniensis (n = 22, 1.5%). The comparative percent distribution of Candida species causing candidemia between 2006–2011 and 2012–2017 was as follows: C. albicans 41.8% and 33.1%, C. parapsilosis complex 32.01% and 37.04%, C. tropicalis 13.59% and 15.31%, and C. glabrata 8.77% and 11.51%, C. krusei 2.0% and 1.7%, and C. dubliniensis 1.75 and 1.3%, respectively. Three of 371 C. albicans isolates during 2006–2011 and five of 363 during 2012–2017 were resistant to fluconazole. Among C. parapsilosis isolates, one of 310 during 2006–2011 and 21 of 446 during 2012–2017 were resistant to this drug. Furthermore, at an epidemiologic cutoff value (ECV) of ≤0.5 μg/ml, 70.1% C. albicans isolates were wild-type for fluconazole during 2006–2011 as compared to 58.1% during 2012–2017. Likewise, at an ECV of ≤2 μg/ml, 98.0% of C. parapsilosis isolates were wild-type during 2006–2011 as compared to 93.4% during 2012–2017. Clonal spread of fluconazole-resistant C. parapsilosis in one major hospital was documented. An 8.8% shift in favor of non-albicans Candida species with concomitant increase in MICs between the two periods preludes emergence of fluconazole-resistant candidemia cases in Kuwait.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S206-S207
Author(s):  
Kaitlin Forsberg ◽  
Meghan Lyman ◽  
Sudha Chaturvedi ◽  
Emily C Schneider ◽  
Jill Fischer ◽  
...  

Abstract Background Many U.S. clinical laboratories lack capacity to definitively identify fungi or perform antifungal susceptibility testing (AFST). To expand testing access, CDC’s Antibiotic Resistance Laboratory Network (AR Lab Network) provides Candida species identification and AFST to U.S. facilities for clinical and public health purposes. We describe the first three years of Candida AR Lab Network resistance data. Methods Isolates from any body site with species identification and AFST performed July 2016–June 2019 are included. Submissions were based on clinical and public health need. Patients may have multiple isolates. The 7 AR Lab Network regional laboratories used matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) or DNA sequencing for species identification. AFST was performed using broth microdilution for azoles and echinocandins (anidulafungin and micafungin) and Etest for amphotericin B. This analysis focuses on non-albicans Candida species with Clinical and Laboratory Standards Institute M60 minimum inhibitory concentration breakpoints and C. auris, which has CDC-proposed tentative breakpoints. Results Participation increased from healthcare facilities from 2 states submitting in 2016 to 35 states in 2019. Species identification was performed on 5,234 non-albicans isolates. AFST was performed on 4,222 (81%) isolates, including 2,395 C. glabrata, 815 C. auris, 267 C. parapsilosis, 125 C. tropicalis, 35 C. guilliermondii, and 32 C. krusei. Of isolates with AFST and body site indicated, 22% (900/4,102) were from blood. We found 85% of C. auris, 8% of C. glabrata, and 5% of C. parapsilosis isolates were resistant to azoles; 33% of C. auris isolates were resistant to amphotericin B; and 2% of C. glabrata, 1% of C. auris, and 1% of C. parapsilosis isolates were resistant to echinocandins. Although intrinsically resistant to fluconazole, C. krusei isolates were not resistant to voriconazole. Multidrug resistance was present in 32% of C. auris and 1% of C. glabrata isolates. Conclusion AR Lab Network has expanded access to rapid Candida testing, including AFST, and provides real-time surveillance. Results can be used to detect emerging species and resistance and guide public health action and healthcare practices. Disclosures All Authors: No reported disclosures


Sign in / Sign up

Export Citation Format

Share Document