Molecular characterization of Candida auris outbreak isolates in Qatar from patients with COVID-19 reveals the emergence of isolates resistant to three classes of antifungal drugs.

OBJECTIVES: During the COVID-19 pandemic in Qatar, many patients who were severely ill were colonized and infected by Candida auris, an invasive multidrug-resistant yeast pathogen that spreads through nosocomial transmission within healthcare facilities. Here, we investigated the molecular epidemiology of these C. auris isolates and the mechanisms associated with antifungal drug resistance. METHODS: Whole genomes of 76 clinical C. auris isolates, including 65 from patients with COVID-19 collected from March 2020 to June 2021, from nine major hospitals were sequenced on Illumina NextSeq. Single nucleotide polymorphisms were used to determine their epidemiological patterns and mechanisms for antifungal resistance. The data were compared with those published prior to the COVID-19 pandemic from 2018 to 2020 in Qatar. RESULTS: Genomic analysis revealed low genetic variability among the isolates from patients with and without COVID-19, confirming a clonal outbreak and ongoing dissemination of C. auris among various healthcare facilities. Based on antifungal susceptibility profiles, more than 70% (22/28) of isolates were resistant to both fluconazole and amphotericin B. Variant analysis revealed the presence of multi-antifungal resistant isolates with prominent amino acid substitutions: Y132F in ERG11 and V704L in CDR1 linked to reduced azole susceptibility and the emergence of echinocandin resistance samples bearing mutations in FKS1 in comparison with pre-COVID-19 pandemic samples. One sample (CAS109) was resistant to three classes of antifungal drugs with a unique premature stop codon in ERG3 and novel mutations in CDR2, which may be associated with elevated amphotericin B and azole resistance. DISCUSSION: Candida auris isolates from patients with COVID-19 and from most patient samples without COVID-19 in Qatar were highly clonal. The data demonstrated the emergence of multidrug-resistant strains that carry novel mutations linked to enhanced resistance to azoles, echinocandins, and amphotericin B. Understanding the epidemiology and drug resistance will inform the infection control strategy and drug therapy.

Pneumatic vs laser lithotripsy for mid-ureteric stones: Clinical and cost effectiveness results of a prospective trial in a developing country.

OBJECTIVE: To compare the management of large ureteric stones (>10 mm) with ureterorenoscopy (URS) and laser or pneumatic lithotripsy, and their associated costs. PATIENTS AND METHODS: Our prospective study followed the tenets of the Declaration of Helsinki and included 101 patients with large mid-ureteric stones eligible for URS and lithotripsy, and was conducted between January 2018 and August 2019. Patients were randomly divided into two groups: Group 1 had laser lithotripsy, while the Group 2 had lithotripsy using a pneumatic energy source. RESULTS: Operative time was significantly longer in cases using pneumatic lithotripsy (P < 0.001). The stone-free rate (SFR) on the first postoperative day was 94% and 92.5% for laser and pneumatic lithotripsy respectively, and there were no statistically significant differences in terms of early (day 1) or late (day 30) SFRs between the groups. Complications were classified according to the Clavien-Dindo Grading System, all complications were Grade