Isolation and Drug Susceptibility of Candida parapsilosis Sensu Lato and other Species of C. parapsilosis Complex from Patients with Blood Stream Infections and Proposal of a Novel LAMP Identification Method for the Species

Abstract

Candida parapsilosis complex (CPC) is the third Candida species isolated in blood cultures of patients from our Hospital, following C. albicans and C. tropicalis. From 2006 to 2010, the median annual distribution of CPC was 8 cases/year. Records of 36 patients were reviewed. CPC were 31 (86.1%) C. parapsilosis; 4 (11.1%) C. orthopsilosis; and 1 (2.8%) C. metapsilosis. Clinical characteristics were central venous catheter, 34 (94.4%); parental nutrition, 25 (70%); surgery, 27 (57.9%); prior bacteremia, 20 (51.3%); malignancy, 18 (50%). General mortality was 47.2%. Death was higher in immunosuppressed patients (17 vs. 11; p = 0.003). Three out four (75%) patients with C. orthopsilosis and 14 out 31 (45.2%) with C. parapsilosis died (p = 0.558). Thirty-nine individual isolates were tested for susceptibility to seven antifungal drugs, with MICs values showing susceptibility to all of them. Two isolates, one C. orthopsilosis and one C. parapsilosis, had fluconazole MIC = 4 μg/mL. Differentiation among CPC has implication in caring for patients with invasive candidiasis since there are differences in virulence, pathogenicity and drug susceptibility. A method targeting the topoisomerase II gene based on loop-mediated isothermal amplification (LAMP) was developed. LAMP emerges as a promising tool for the identification of fungal species due to the high sensitivity and specificity. LAMP can be performed at the point-of-care, being no necessary the use of expensive equipment. In our study, the method was successful comparing to the DNA sequencing and proved to be a reliable and fast assay to distinguish the three species of CPC.

Simple, Low-Cost Detection of Candida parapsilosis Complex Isolates and Molecular Fingerprinting of Candida orthopsilosis Strains in Kuwait by ITS Region Sequencing and Amplified Fragment Length Polymorphism Analysis

“…parapsilosis by culture-based phenotypic methods. These species exhibit differences in minimum inhibitory concentrations (MICs) for antifungal drugs warranting species-specific identification [ 5 , 9 , 11 , 12 ]. Furthermore, it has been shown that the species identified from the catheter is not always responsible for the bloodstream infection [ 6 ].…”

“…Consistent with earlier reports, 14 of 15 C . orthopsilosis isolates were also susceptible to all antifungal drugs tested while only one isolate showed reduced susceptibility or resistance to some antifungal drugs [ 5 , 9 , 11 , 12 ]. Although C .…”

“…However, species-specific identification of C . parapsilosis complex is important in patient management and choosing the appropriate treatment due to differences in antifungal susceptibly profile [ 5 , 9 , 11 , 12 ]. Phenotypically, it is not possible to distinguish these closely related species.…”

Molecular identification and antifungal susceptibility profiles of Candida parapsilosis complex species isolated from culture collection of clinical samples

“…Although Trabasso et al (44) observed some fluctuations in MIC values between the three C. parapsilosis complex species, they also showed that these isolates were susceptible to echinocandin, with MIC values within those of the reference strain or the proposed MIC values (CLSI). However, 19.5% (17/87) of C. parapsilosis complex isolates studied in our work were less susceptible to CAS, with resistance detected in eight isolates of C. parapsilosis sensu stricto (Table 1).…”

Complexo Candida parapsilosis: identificação molecular das espécies, análise proteômica dos biofilmes por MALDI-TOF MS e investigação de um surto envolvendo isolados clínicos resistentes aos azólicos

“…Candida parapsilosis (sensu stricto) tem sido descrita como a espécie mais comum entre os isolados clínicos do complexo C. parapsilosis, representando mais de 80% do total (Xiao et al, 2015;Barchiesi et al, 2016;Lovero et al, 2016;Magobo et al, 2017;Moreno et al, 2017;Neji, Trabelsi, et al, 2017). Menos de 20% dos nossos isolados foram identificados como C. orthopsilosis e C. metapsilosis (Tabelas 4 e 5), em acordo com outros estudos brasileiros (Bonfietti et al, 2012;Trabasso et al, 2015;Ziccardi et al, 2015), e mostrando que a distribuição dessas espécies se mantém inalterada no país.…”