Candida auris in Dog Ears.

Candida auris is an emerging global public health threat and is resistant to most antifungal agents. Though fungi are significant pathogens for animals, the role of C. auris in animal health remains unexplored. Here, we analysed the microbial cultures of skin and ear swabs of 87 dogs in Delhi and performed fungal meta-barcode sequencing of ear and skin samples of 7 dogs with confirmed otitis externa (OE). Overall, 4.5% of dogs (4/87) with chronic skin infections contained evidence of C. auris in their ear canal (n = 3) and on their skin surface (n = 1). Of the three OE dogs with C. auris infection/colonisation, a diversity of fungi was observed, and their meta-barcode ITS sequence reads for C. auris ranged from 0.06% to 0.67%. Whole-genome sequencing of six C. auris strains obtained in culture from two dogs showed relatedness with Clade I clinical strains. The report highlights the isolation of C. auris from an animal source; however, the routes of transmission of this yeast to dogs and the clinical significance of transmission between dogs and humans remain to be investigated.

Candida auris Genetics and Emergence.

Candida auris is a multidrug-resistant fungal pathogen that presents a serious threat to global human health. Since the first reported case in 2009 in Japan, C. auris infections have been reported in more than 40 countries, with mortality rates between 30% and 60%. In addition, C. auris has the potential to cause outbreaks in health care settings, especially in nursing homes for elderly patients, owing to its efficient transmission via skin-to-skin contact. Most importantly, C. auris is the first fungal pathogen to show pronounced and sometimes untreatable clinical drug resistance to all known antifungal classes, including azoles, amphotericin B, and echinocandins. In this review, we explore the causes of the rapid spread of C. auris. We also highlight its genome organization and drug resistance mechanisms and propose future research directions that should be undertaken to curb the spread of this multidrug-resistant pathogen.

Genomic Analyses of a Fungemia Outbreak Caused by Lodderomyces elongisporus in a Neonatal Intensive Care Unit in Delhi, India.

Lodderomyces elongisporus is a recently emerging yeast pathogen predominantly reported in adult patients who had immunosuppression and/or intravenous access devices. Here, we report a fungemia outbreak caused by L. elongisporus in a neonatal intensive care unit (NICU) in Delhi, India, from September 2021 to February 2022. All 10 neonates had low birthweight, and nine of the patients survived after amphotericin B treatment. Whole-genome sequence analyses of the patient isolates as well as those from other sources in India grouped them into two clusters: one cluster consists of isolates exclusively from stored apples and the other cluster includes isolates from patients, clinical environments, and stored apples. All outbreak strains from patients were closely related to each other and showed highly similar heterozygosity patterns across all 11 major scaffolds. While overall very similar, strains from the inanimate environment of the same neonatal intensive care unit showed loss of heterozygosity at scaffold 2 (NW_001813676) compared to the patient strains. Interestingly, evidence for recombination was found in all samples. All clinical strains were susceptible to 10 tested antifungal drugs, and comparisons with strains with high fluconazole MICs derived from the surface of stored apples revealed significant genome divergence between the clinical and apple surface strains, including 119 nonsynonymous single nucleotide polymorphisms (SNPs) in 24 triazole resistance-related genes previously found in other Candida spp. Together, our results indicate significant diversity, recombination, and persistence in the hospital setting and a high rate of evolution in this emerging yeast pathogen. IMPORTANCE Lodderomyces elongisporus was initially considered a teleomorph of Candida parapsilosis. However, DNA sequence analyses revealed it as a distinctive species. Invasive infections due to L. elongisporus have been reported globally. We report an outbreak of fungemia due to L. elongisporus in a NICU affecting 10 preterm, low-birthweight neonates during a period of 6 months. The outbreak investigation identified two environmental sites, the railing and the temperature panel of the neonate open care warmer, harboring L. elongisporus. Whole-genome sequencing confirmed that the neonate isolates were closely related to each other whereas strains from the inanimate clinical environment were related to clinical strains but showed a marked loss of heterozygosity. Further, L. elongisporus strains recovered previously from the surface of stored apples showed high fluconazole MICs and alterations in triazole resistance-related genes. Genome-wide SNP comparisons revealed recombination as an important source for genomic diversity during adaptation of L. elongisporus to different environments.

Candida auris on Apples: Diversity and Clinical Significance.

Candida auris is a multidrug-resistant nosocomial fungal pathogen. While the marine environment was recently identified as a natural niche for C. auris, the environment(s) that might have contributed to the development and spread of antifungal resistance in C. auris remains a mystery. Because stored fruits are often treated with fungicides to prevent postharvest spoilage, we hypothesized that stored fruits could serve as a possible selective force for and a transmission reservoir of antifungal-resistant isolates of pathogenic yeasts, including C. auris. To test this hypothesis, we screened fruits to study the diversity of pathogenic yeasts and their antifungal susceptibility profiles. Among the 62 screened apples, the surfaces of 8 were positive for C. auris, and all were stored apples. Whole-genome sequencing (WGS) showed that C. auris strains from apples were genetically diverse and exhibited broad phylogenetic distribution among the subclades within clade I. Interestingly, strains from apples had closely related strains from other sources in India, including from patients, hospitals, and marine environments, and from clinical strains from other parts of the world. A broad range of fungicides, including dimethyl inhibitors (DMIs), were detected in stored apples, and all C. auris isolates exhibited reduced sensitivity to DMIs. Interestingly, C. auris was not isolated from freshly picked apples. Together, the results suggest a potentially complex ecology for C. auris with agriculture fungicide application on stored fruits as a significant selective force for drug resistance in clinics. IMPORTANCE In 2019, the U.S. Centers for Disease Control and Prevention classified the multidrug-resistant Candida auris as one of five pathogens posing the most urgent threats to public health. At present, the environment(s) that might have contributed to the development and spread of antifungal resistance in C. auris is unknown. Here, we tested whether fruits could be a source of multidrug-resistant C. auris. We identified genetically diverse C. auris strains with reduced sensitivity to major triazole dimethyl inhibitors fungicides on the surfaces of stored apples. The successful isolation of C. auris from apples here calls for additional investigations into plants as a reservoir of C. auris. Our findings suggest that C. auris in the natural ecosystem may come in contact with agriculture fungicides and that stored fruits could be a significant niche for the selection of azole resistance in C. auris and other human fungal pathogens.

Development of a Multiplex PCR Short Tandem Repeat Typing Scheme for Candida krusei.

Candida krusei is a human-pathogenic yeast that can cause candidemia with the lowest 90-day survival rate in comparison to other Candida species. Infections occur frequently in immunocompromised patients, and several C. krusei outbreaks in health care facilities have been described. Here, we developed a short tandem repeat (STR) typing scheme for C. krusei to allow the fast and cost-effective genotyping of an outbreak and compared the identified relatedness of 10 isolates to single nucleotide polymorphism (SNP) calling from whole-genome sequencing (WGS). From a selection of 14 novel STR markers, 6 were used to develop two multiplex PCRs. Additionally, three previously reported markers were selected for a third multiplex PCR. In total, 119 C. krusei isolates were typed using these nine markers, and 79 different genotypes were found. STR typing correlated well with WGS SNP typing, as isolates with the same STR genotype varied by 8 and 19 SNPs, while isolates that differed in all STR markers varied by at least tens of thousands of SNPs. The STR typing assay was found to be specific for C. krusei, stable in 100 subcloned generations, and comparable to SNP calling by WGS. In summary, this newly developed C. krusei STR typing scheme is a fast, reliable, easy-to-interpret, and cost-effective method compared to other typing methods. Moreover, the two newly developed multiplexes showed the same discriminatory power as all nine markers combined, indicating that multiplexes M3-1 and M9 are sufficient to type C. krusei.

A High Frequency of Candida auris Blood Stream Infections in Coronavirus Disease 2019 Patients Admitted to Intensive Care Units, Northwestern India: A Case Control Study.

BACKGROUND: The ongoing pandemic of coronavirus disease 2019 (COVID-19) has overwhelmed healthcare facilities and raises an important novel concern of nosocomial transmission of Candida species in the intensive care units (ICUs). METHODS: We evaluated the incidence and risk factors for development of candidemia in 2384 COVID-19 patients admitted during August 2020-January 2021 in ICUs of 2 hospitals (Delhi and Jaipur) in India. A 1:2 case-control matching was used to identify COVID-19 patients who did not develop candidemia as controls. RESULTS: A total of 33 patients developed candidemia and accounted for an overall incidence of 1.4% over a median ICU stay of 24 days. A 2-fold increase in the incidence of candidemia in COVID-19 versus non-COVID-19 patients was observed with an incidence rate of 14 and 15/1000 admissions in 2 ICUs. Candida auris was the predominant species (42%) followed by Candida tropicalis. Multivariable regression analysis revealed the use of tocilizumab, duration of ICU stay (24 vs 14 days), and raised ferritin level as an independent predictor for the development of candidemia. Azole resistance was observed in C auris and C tropicalis harboring mutations in the azole target ERG11 gene. Multilocus sequence typing (MLST) identified identical genotypes of C tropicalis in COVID-19 patients, raising concern for nosocomial transmission of resistant strains. CONCLUSIONS: Secondary bacterial infections have been a concern with the use of tocilizumab. In this cohort of critically ill COVID-19 patients, tocilizumab was associated with the development of candidemia. Surveillance of antifungal resistance is warranted to prevent transmission of multidrug-resistant strains of nosocomial yeasts in COVID-19 hospitalized patients.

Evaluation of hypoglycemic and anti-hyperglycemic potential of Tridax procumbens (Linn.).

BACKGROUND: Diabetes is a metabolic disorder affecting carbohydrate, fat and protein metabolism. Tridax procumbens Linn. (Family-Asteraceae; common name-Dhaman grass) is common herb found in India. Traditionally, the tribal inhabitants of Udaipur district in Rajasthan (India) uses the leaf powder (along with other herb) orally to treat diabetes. There is a need to evaluate extracts of this plant in order to provide scientific proof for it's application in traditional medicine system. METHODS: Extraction of whole plant of T. procumbens using 50%methanol. The extract was tested for acute and sub-chronic anti-hyperglycemic activity in alloxan induced diabetic rats and for acute toxicity test among normal rats. Observations on body weight as well as on the oral glucose tolerance levels were also recorded. RESULTS: Oral administration of acute and sub chronic doses (250 and 500 mg/kg b.wt.) of T. procumbens extract showed a significant (p < 0.05) reduction in fasting blood glucose levels in diabetic rats, however the decline in blood sugar levels in normal rats was not observed. In acute study the maximum percent blood glucose reduction (68.26% at 250 mg/kg and 71.03% at 500 mg/kg body weight) in diabetic rats was observed at 6 h. The anti-hyperglycemic effects were not dependent of dose and the OGTT and Body weight supported the antihyperglycemic action of the drug. The results of anti-diabetic effect of T. procumbens were compared with the reference standard drug Glibenclamide (10 mg/kg b.wt.). CONCLUSION: These test results support traditional medicinal use of, T. procumbens for the treatment of diabetes mellitus with corrections in body weight and oral glucose tolerance and no visible signs or symptoms of toxicity in normal rats indicating a high margin of safety. These results warrant follow-up through bioassay-directed isolation of the active principles.