Molecular Detection of Dermatophytes and Nondermatophytes in Onychomycosis in Antalya, Turkey.

BACKGROUND: Onychomycosis is a chronic nail infection, and dermatophytes, yeasts, and nondermatophytic molds may be the causative agents. This study aimed to determine the etiological agents of onychomycosis by using conventional and molecular methods. METHODS: Between June 2020 and July 2021, 37 patients with a presumptive diagnosis of onychomycosis and mycological evidence (culture and/or EUROArray Dermatomycosis assay) were included in the study. Organisms detected in cultured nail specimens were identified by combined phenotypic characteristics and by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). An EUROarray Dermatomycosis assay was used for molecular detection of fungal pathogens. RESULTS: The EUROArray Dermatomycosis assay was positive for a single fungal target in 23 samples, and 14 samples were positive by culture. The most common pathogen was Trichophyton rubrum in both methods. Coinfection was detected in 14 samples by using molecular methods, and Trichophyton rubrum and Fusarium solani (9 samples) were the most common pathogens detected together. Trichophyton spp., nondermatophyte molds, and Candida spp. were detected in 33 (89.2%), 16 (43.2%), and 6 (16.2%) samples, respectively, when the two methods were evaluated together. CONCLUSIONS: Our results revealed that fungal culture allows the diagnosis of onychomycosis, but it is not as sensitive as the EUROArray Dermatomycosis test, especially in patients receiving antifungal therapy.

Candidemia Cases Caused by Candida parapsilosis Complex Species: Epidemiology and Antifungal Susceptibility of Strains.

BACKGROUND: Candida parapsilosis is a common non-albicans Candida species isolated from blood cultures. The increase in fluconazole-resistant C. parapsilosis complex isolates is worrying, especially in strains with Y132F changes in the ERG11 gene since this ultimately leads to outbreaks. This study aimed to investigate the distribution and antifungal susceptibility of C. parapsilosis complex species isolated from bloodstream, clinical characteristics of patients, prevalence of risk factors, and to determine ERG11 gene region mutations in strains that were not susceptible to fluconazole. METHODS: Between 2014 and 2018, 96 patients with C. parapsilosis candidemia were evaluated. Thermo Scientific SensititerTM YeastOneTM YO10 was used for antifungal susceptibility testing. The ERG11 gene region sequence analysis was performed for fluconazole non-susceptible isolates. RESULTS: All the strains were defined as C. parapsilosis sensu stricto. The rate of fluconazole resistance was 6.3%, and that of susceptibility to fluconazole at an increased dose was 2.1%. Two isolates showed Y132F or G458S ERG11 changes associated with azole resistance, with the most common change being identified as R398I, which was shown not to encode azole resistance. No resistance to echinocandins and amphotericin B was observed. The use of broad-spectrum antibiotics (83.3%) was the most common risk factor. CONCLUSIONS: This study highlights the importance of susceptibility testing when making a decision to use fluconazole in the treatment of C. parapsilosis candidemia. The presence of resistance associated with ERG11 Y132F changes indicated that azole resistance should be closely monitored. Increasing awareness of fluconazole-resistant C. parapsilosis candidemia will help identify strategies to overcome these infections.

Evaluation of the BD Phoenix CPO Detect Test for the detection of carbapenemase-producing Enterobacterales.

Aims: This study aimed to evaluate the performance of the BD Phoenix CPO Detect Test (BD Diagnostic Systems) for the detection and classification of carbapenemase-mediated carbapenem resistance. Methods: A total of 447 Enterobacterales strains were included in the study. All strains were tested with the BD Phoenix CPO Detect Test and the modified carbapenem inactivation method. Results: Carbapenemase production was detected in 157 of 159 carbapenemase producers, including 95.7% of class B and 99.2% of class D isolates using the BD Phoenix CPO Detect Test. BD Phoenix CPO Detect has a sensitivity of 98.7% and a specificity of 95.5% in detecting carbapenemase production. Conclusion: The classification of OXA-48 and class B carbapenemases, the most common carbapenemases circulating in Turkey, was highly accurate.

Enterobacterales are a type of bacteria that usually live harmlessly in the gut of humans. However, if the bacteria get access to the bladder or bloodstream, they can cause infection. Carbapenemase-producing Enterobacterales (CPE) are a type of bacteria that can cause carbapenem antibiotic-resistant infections, a group of powerful antibiotics. The rapid spread of CPE will pose an increasing threat to public health and medical treatment practices; therefore, rapid detection of CPE is crucial. This study assessed the performance of the BD Phoenix CPO Detect Test for the detection of carbapenemase-producing Enterobacterales. The BD Phoenix CPO Detect Test offers both the detection of carbapenemase production and antimicrobial susceptibility testing simultaneously and can be clinically useful for determining possible treatment options.

In vitro Activity of Cefiderocol and Ceftazidime-Avibactam, Against Carbapenemase-Producing Enterobacterales.

BACKGROUND: Carbapenemase production is an issue of significant clinical and public health concern, because of the shortage of effective antimicrobial agents available for treatment. Here, we present antimicrobial susceptibility data of ceftazidime-avibactam, cefiderocol, and other clinically relevant antibiotics for carbapenemase-producing Enterobacterales bloodstream isolates, in accordance with European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. METHODS: A total of 133 carbapenemase producing Enterobacterales bloodstream isolates from May 2010 to September 2018 were included in the study. Species were identified using matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (Bruker Daltonics, Germany). The presence of the blaKPC, blaNDM, blaOXA-48, blaVIM, and blaIMP carbapenemase genes were investigated by BD Max CRE assay (Becton Dickinson, USA) and in-house PCR. Antimicrobial susceptibility testing was performed by the BD Phoenix automated system (Becton Dickinson, USA), except cefiderocol and colistin. Cefiderocol and colistin susceptibility was determined by disk diffusion and broth microdilution method, respectively. RESULTS: Except for cefiderocol and ceftazidime-avibactam, the percentage of susceptible isolates did not exceed 90% for any of the antibiotics tested. Although none of the isolates were resistant to cefiderocol, the ceftazidime-avibactam resistance rate was 9.8%. All of the ceftazidime-avibactam resistant strains were NDM (New Delhi metallo-beta-lactamases) producers. Among the other clinically relevant antibiotics tested, only amikacin, colistin, tigecycline, and fosfomycin susceptibility rates exceeded 50%. Of the 133 isolates 22.6% were resistant to colistin which is the preferred antibiotic with a second active agent for infections caused by metallo-beta-lactamase producing Enterobacterales in Turkey. CONCLUSIONS: In our study, resistance to ceftazidime-avibactam was detected only in metallo-beta-lactamase producing Enterobacterales isolates, while cefiderocol was found to be effective against all strains. It is important to monitor regional antimicrobial susceptibility data, as the emergence of antimicrobial resistant phenotypes is directly linked to the use of any given antimicrobial agent.

The Evaluation of the Performance of C. Diff Quik Chek Complete and Toxin A + B (Clostridium difficile) DUO Diagnostic Tests Compared with Toxigenic Culture in the Diagnosis of Clostridium difficile Infection.

BACKGROUND: Clostridium difficile is an important cause of nosocomial diarrhea and the best standard laboratory method for the diagnosis of C. difficile infection is controversial. In this study, we aimed to investigate the performance of Toxin A + B (Clostridium difficile) DUO kit which detects C. difficile toxin A and B by the immunochromatographic method and C. Diff Quik Chek Complete (QCC) rapid membrane immunoassay kit which determines the presence of glutamate dehydrogenase (GDH) and C. difficile toxin A and B in stool samples, compared with toxigenic culture in the diagnosis of C. difficile infection. METHODS: One hundred ninety-three stool samples from patients suspected of having C. difficile infection were included in the study. The performances of two commercial tests were compared with toxigenic culture which was accepted as the reference method. RESULTS: The sensitivity and specificity of the GDH component of QCC were 94.4% and 97.7%, the sensitivity and specificity of the toxin component were 92.3% and 100%, respectively. The sensitivity and specificity of Toxin A + B (Clostridium difficile) DUO test were found as 53.8% and 87.8%, respectively. CONCLUSIONS: C. Diff Quik Chek Complete test, which is a rapid test with high sensitivity and specificity, can be used alone for the diagnosis of C. difficile infection while Toxin A + B (Clostridium difficile) DUO test cannot be used for the same purpose due to the low sensitivity and specificity of the test.