Candida auris is an emerging, multidrug-resistant fungal pathogen that has become a public health threat with an increasing incidence of infections worldwide. Candida auris spreads easily among patients within and between hospitals. Infections and outbreaks caused by C. auris have been reported in the Middle East region including Oman, Kuwait, Saudi Arabia, and Qatar; however, the origin of these isolates is largely unknown. Pathogen whole genome sequencing (WGS) was used to determine the epidemiology and drug resistance mutations of C. auris in Qatar. Forty-four samples isolated from patients in three hospitals and the hospital environment were sequenced by Illumina NextSeq. Core genome single nucleotide polymorphisms (SNPs) revealed that all isolates belonged to the South Asian lineage with genetic heterogeneity that suggests previous acquisition from foreign healthcare. The genetic variability among the outbreak isolates in the two hospitals (A and B) was low. Four environmental isolates clustered with the related clinical isolates, and epidemiologically linked isolates clustered together, suggesting that the ongoing transmission of C. auris could be linked to infected/colonized patients and the hospital environment. Prominent mutations Y132F and K143R in ERG11 linked to increased fluconazole resistance were detected.

Aspergillus are ubiquitous mold species that infect immunocompetent and immunocompromised patients. The symptoms are diverse and range from allergic reactions, bronchopulmonary infection, and bronchitis, to invasive aspergillosis. The aim of this study was to characterize 70 Aspergillus isolates recovered from clinical specimens of patients with various clinical conditions presented at Hamad general hospital in Doha, Qatar, by using molecular methods and to determine their in vitro antifungal susceptibility patterns using the Clinical and Laboratory Standards Institute (CLSI) M38-A2 reference method. Fourteen Aspergillus species were identified by sequencing β-tubulin and calmodulin genes, including 10 rare and cryptic species not commonly recovered from human clinical specimens. Aspergillus welwitschiae is reported in this study for the first time in patients with fungal rhinosinusitis (n = 6) and one patient with a lower respiratory infection. Moreover, Aspergillus pseudonomius is reported in a patient with fungal rhinosinusitis which is considered as the first report ever from clinical specimens. In addition, Aspergillus sublatus is reported for the first time in a patient with cystic fibrosis. In general, our Aspergillus strains exhibited low MIC values for most of the antifungal drugs tested. One strain of Aspergillus fumigatus showed high MECs for echinocandins and low MICs for the rest of the drugs tested. Another strain of A. fumigatus exhibited high MIC for itraconazole and categorized as non-wild type. These findings require further analysis of their molecular basis of resistance. In conclusion, reliable identification of Aspergillus species is achieved by using molecular sequencing, especially for the emerging rare and cryptic species. They are mostly indistinguishable by conventional methods and might exhibit variable antifungal susceptibility profiles. Moreover, investigation of the antifungal susceptibility patterns is necessary for improved antifungal therapy against aspergillosis.

With the evolving COVID-19 pandemic, increasing concerns about invasive fungal infections have been reported particularly with the use of potent immunosuppressant medications to treat the immunological storms in patients with severe COVID-19 illnesses. Trichosporon asahii (T. asahii) is an emerging highly resistant pathogen with considerable mortality particularly in critically ill patients and immunocompromised individuals. We describe a case of a 58-year-old patient who developed T. asahii fungemia after using immunosuppressant agents for his severe COVID-19 related cytokines release syndrome. Pseudohyphae, arthroconidia, and lateral blastoconidia were seen in the stain, and later confirmed to be T. asahii. Voriconazole successfully treated this multi-drug-resistant fungal infection. The clinical presentation, assessment, and management are reviewed to raise awareness of the circumstances leading to coinfection with this emerging resistant yeast.

Candida dubliniensis is an emerging yeast and demonstrated a high adherence property to cystic fibrosis respiratory tract. Therefore, it is important to determine the persistence of C. dubliniensis and to assess the possible relationship to the body mass index (BMI) and forced expiratory volume in 1st second (FEV1). Candida isolates were identified by MALDI-TOF MS to species level from 40/52 (76.9%) cystic fibrosis patients. C. dubliniensis was the most common organism isolated from 50/77 (65%) lower respiratory specimens of 29 patients. Patients with persistent C. dubliniensis isolates have higher mean BMI in comparison to intermittent C. dubliniensis group. However, this difference did not reach statistical significance (P = 0.539). In contrast, patients with persistent C. dubliniensis isolates have significantly lower FEV1% mean in comparison to intermittent C. dubliniensis group particularly at initial two visits (P < 0.05); however, at subsequent visit the difference observed was not statistically significant (P = 0.456). The persistence of C. dubliniensis is more frequent in adults having more advanced disease, co-infections with chronic P. aeruginosa, cystic fibrosis related diabetes, long-term nebulized tobramycin and oral Zithromax therapy than patients with intermittent C. dubliniensis. Patients with persistent C. dubliniensis have lower FEV1 percentage and higher BMI than the intermittent C. dubliniensis.