Candida auris: An Overview of the Emerging Drug-Resistant Fungal Infection

Health Care-Associated Infections in Older Adults: Epidemiology and Prevention

Health care-associated infections (HAIs) are a global public health threat, which disproportionately impact older adults. Host factors including aging-related changes, comorbidities, and geriatric syndromes, such as dementia and frailty, predispose older individuals to infection. The HAI risks from medical interventions such as device use, antibiotic use, and lapses in infection control follow older adults as they transfer among a network of interrelated acute and long-term care facilities. Long-term care facilities are caring for patients with increasingly complex needs, and the home-like communal environment of long-term care facilities creates distinct infection prevention challenges.

Increasing Number of Cases Due to Candida auris in North Italy, July 2019-December 2022

Candida auris is an emerging fungus that represents a serious health threat globally. In Italy, the first case was detected in July 2019. Then, one case was reported to the Ministry of Health (MoH) on January 2020. Nine months later, a huge number of cases were reported in northern Italy. Overall, 361 cases were detected in 17 healthcare facilities between July 2019 and December 2022 in the Liguria, Piedmont, Emilia-Romagna, and Veneto regions, including 146 (40.4%) deaths. The majority of cases (91.8%) were considered as colonised. Only one had a history of travel abroad. Microbiological data on seven isolates showed that all but one strain (85.7%) were resistant to fluconazole. All the environmental samples tested negative. Weekly screening of contacts was performed by the healthcare facilities. Infection prevention and control (IPC) measures were applied locally. The MoH nominated a National Reference Laboratory to characterise C. auris isolates and store the strains. In 2021, Italy posted two messages through the Epidemic Intelligence Information System (EPIS) to inform on the cases. On February 2022, a rapid risk assessment indicated a high risk for further spread within Italy, but a low risk of spread to other countries.

Emergence of Clonally-Related South Asian Clade I Clinical Isolates of Candida auris in a Greek COVID-19 Intensive Care Unit

Candida auris has recently emerged as a multidrug-resistant yeast implicated in various healthcare-associated invasive infections and hospital outbreaks. In the current study, we report the first five intensive care unit (ICU) cases affected by C. auris isolates in Greece, during October 2020-January 2022. The ICU of the hospital was converted to a COVID-19 unit on 25 February 2021, during the third wave of COVID-19 in Greece. Identification of the isolates was confirmed by Matrix Assisted Laser Desorption Ionization Time of Flight mass spectroscopy (MALDI-TOF]. Antifungal susceptibility testing was performed by the EUCAST broth microdilution method. Based on the tentative CDC MIC breakpoints, all five C. auris isolates were resistant to fluconazole (≥32 μg/mL), while three of them exhibited resistance to amphotericin B (≥2 μg/mL). The environmental screening also revealed the dissemination of C. auris in the ICU. Molecular characterization of C. auris clinical and environmental isolates was performed by MultiLocus Sequence Typing (MLST) of a set of four genetic loci, namely ITS, D1/D2, RPB1 and RPB2, encoding for the internal transcribed spacer region (ITS) of the ribosomal subunit, the large ribosomal subunit region and the RNA polymerase II largest subunit, respectively. MLST analysis showed that all isolates possessed identical sequences in the four genetic loci and clustered with the South Asian clade I strains. Additionally, PCR amplification and sequencing of the CJJ09_001802 genetic locus, encoding for the "nucleolar protein 58" that contains clade-specific repeats was performed. Sanger sequence analysis of the TCCTTCTTC repeats within CJJ09_001802 locus also assigned the C. auris isolates to the South Asian clade I. Our study confirms that C. auris is an emerging yeast pathogen in our region, especially in the setting of the ongoing COVID-19 worldwide pandemic. Adherence to strict infection control is needed to restrain further spread of the pathogen.

Candida auris as an Emergent Public Health Problem: A Current Update on European Outbreaks and Cases

Candida auris is considered to be an emerging fungal pathogen and is related to high mortality rates, persistent candidemia, inconsistencies in susceptibility testing results and misidentification by available commercial identification systems. Multidrug-resistant (MDR) and pandrug-resistant (PDR) strains are increasingly detected. In Europe, hospital outbreaks caused by C. auris have been reported in the United Kingdom (UK), Italy and Spain; however, several cases have been sporadically detected in all European countries. C. auris is difficult to control despite enhanced control measures due to its ability to survive for a long time in environments and colonize patients for prolonged periods. An adequate laboratory diagnostic capacity and national surveillance are fundamental to rapidly detect new C. auris cases and to apply the correct measures to circumscribe them and prevent their spread. Our narrative review aims to highlight the primary C. auris outbreaks and case reports that have occurred in Europe.

Candidiasis and Other Emerging Yeasts

Purpose of Review

The review presents a comprehensive and updated information on the contemporary status of invasive candidiasis (IC), other emerging yeast infections, and the challenges they present in terms of at-risk population, specific virulence attributes, and antifungal susceptibility profile.

Recent Findings

With the advancement in medical field, there has been parallel expansion of vulnerable populations over the past two decades. This had led to the emergence of a variety of rare yeasts in healthcare settings, both Candida and non-Candida yeast causing sporadic cases and outbreaks. The advancements in diagnostic modalities have enabled accurate identification of rare Candida species and non-Candida yeast (NCY) of clinical importance. Their distribution and susceptibility profile vary across different geographical regions, thus necessitating surveillance of local epidemiology of these infections to improve patient outcomes.

Summary

The challenges in management of IC have been complicated with emergence of newer species and resistance traits. C. tropicalis has already overtaken C. albicans in many Asian ICUs, while C. auris is rising rapidly worldwide. Recent genomic research has reclassified several yeasts into newer genera, and an updated version of MALDI-TOF MS or ITS sequencing is necessary for accurate identification. Having a knowledge of the differences in predisposing factors, epidemiology and susceptibility profile of already established pathogenic yeasts, as well as new emerging yeasts, are imperative for better patient management.

Hydrophobic diversification is the key to simultaneously increased antifungal activity and decreased cytotoxicity of two ab initio designed peptides

The fact that some antimicrobial peptides have been utilized clinically and as food preservatives stimulated the efforts in search of new candidates. In our previous studies, we succeeded in designing potent peptides against methicillin-resistant Staphylococcus aureus (MRSA), severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), and Ebola viruses based on the database filtering technology. The designed peptides were proved highly potent. However, this ab initio method has not been utilized to design antifungal peptides. This study report two novel antifungal peptides with 21 and 15 amino acids designed by more effectively extracting the most probable parameters from ∼1200 antifungal peptides in the antimicrobial peptide database (APD). Subsequent hydrophobic diversification led to two peptide variants with enhanced activity against four fungal strains but reduced cytotoxicity to four mammalian cell lines. DFTAFP-1A (KWSGAAAKKLKSLLSGLGKLL) and DFTAFP-2A (KWSGLLLKLGAASKL) retained activity against Zygosaccharomyces bailii at pH 5.6 and 6.3 or after autoclave. The peptides could permeabilize fungal membranes and adopted helical conformations in membrane mimetic micelles. Collectively, this study demonstrated not only the successful design of two novel antifungal peptides based on the APD database but also optimization of desired peptide properties. This improved database approach may be utilized to design useful peptides to combat other drug-resistant pathogens as well.