Tag: Candida auris

Drug-resistant C. auris Confirmed to Spread Rapidly in European Hospitals

The latest survey from the European Centre for Disease Prevention and Control (ECDC), the fourth of its kind, confirms that Candidozyma auris (formerly Candida auris) continues to spread quickly across European hospitals, posing a serious threat to patients and healthcare systems. Case numbers are rising, outbreaks are growing in scale, and several countries report ongoing local transmission. The findings highlight the importance of early detection and control of transmission to avoid widespread rapid dissemination.

Candidozyma auris (C. auris) is a fungus that usually spreads within healthcare facilities, is often resistant to antifungal drugs, and can cause severe infections in seriously ill patients. Its ability to persist on different surfaces and medical equipment and to spread between patients makes it particularly challenging to control. Between 2013 and 2023, EU/EEA countries reported over 4 000 cases, with a significant jump to 1 346 cases reported by 18 countries in 2023 alone. Five countries – Spain, Greece, Italy, Romania, and Germany – have accounted for most of the cases over the decade.

C. auris has spread within only a few years – from isolated cases to becoming widespread in some countries. This shows how rapidly it can establish itself in hospitals,” said Dr Diamantis Plachouras, Head of ECDC’s Antimicrobial Resistance and Healthcare-Associated Infections Section. “But this is not inevitable,” he added. “Early detection and rapid, coordinated infection control can still prevent further transmission.”

Recent outbreaks have been reported in Cyprus, France and Germany, while Greece, Italy, Romania and Spain have indicated they can no longer distinguish specific outbreaks due to widespread regional or national dissemination. In several of these countries, sustained local transmission has occurred within only a few years after the first documented case, highlighting a critical window for early interventions to stop its spread.

While some countries have showed positive results in limiting C. auris outbreaks, many are facing key gaps. Despite rising case numbers, only 17 of 36 participating countries currently have a national surveillance system in place for C. auris. Only 15 countries have developed specific national infection prevention and control guidance. Laboratory capacity is comparatively stronger, with 29 countries reporting access to a mycology reference or expert laboratory and 23 offering reference testing for hospitals.

While the number of C. auris infections is clearly rising, without systematic surveillance and mandatory reporting, the true scale of the problem is likely under-reported.

ECDC has regularly assessed the epidemiological situation, laboratory capacity and preparedness for C. auris in four surveys since 2018 and published rapid risk assessments including options for infection prevention and control. This is to support Member States in improving their preparedness and early response capacities to prevent or contain C. auris outbreaks in a timely manner and prevent further transmission.

Source: EurekAlert!

Plant Compound could Prove to be a Potent Tool against Candida

Photo by CDC on Unsplash

A new study published in the journal ACS Infectious Diseases has found that a natural compound found in many plants inhibits the growth of drug-resistant Candida fungi – including its most virulent species, Candida auris, an emerging global health threat.

Led by Emory University researchers, the study used in vitro experiments that showed that the natural compound, a water-soluble tannin known as PGG, blocks 90% of the growth in four different species of Candida fungi. The researchers also discovered the mechanism by which PGG inhibits the growth: It grabs up iron molecules, essentially starving the fungi of an essential nutrient.

By starving the fungi rather than attacking it, the PGG mechanism does not promote the development of further drug resistance, unlike existing antifungal medications. In vitro testing also showed minimal toxicity of PGG to human cells.

“Drug-resistant fungal infections are a growing healthcare problem but there are few new antifungals in the drug-development pipeline,” says Cassandra Quave, senior author of the study and assistant professor at Emory University. “Our findings open a new potential approach to deal with these infections, including those caused by deadly Candida auris.”

C. auris is often multidrug-resistant and has a high mortality rate, leading the Centers for Disease Control and Prevention (CDC) to label it a serious global health threat.

“It’s a really bad bug,” says Lewis Marquez, first author of the study and a graduate student in Emory’s molecular systems and pharmacology programme. “Between 30 to 60% of the people who get infected with C. auris end up dying.”

An emerging threat

Some species of Candida, a yeast commonly found on the skin or in the digestive tract, can cause infection, which can be invasive and life-threatening. Immunocompromised people, including many hospital patients, are most at risk for invasive Candida infections, which are rapidly evolving drug resistance.

In 2007, the new Candida species, C. auris, emerged in a hospital patient in Japan. Since then, C. auris has caused health care-associated outbreaks in more than a dozen countries around the world with more than 3000 clinical cases reported in the United States alone.

A ‘natural’ approach to drug discovery

Quave is an ethnobotanist, studying how traditional people have used plants for medicine to search for promising new candidates for modern-day drugs. Her lab curates the Quave Natural Product Library, which contains 2500 botanical and fungal natural products extracted from 750 species collected at sites around the world.

“We’re not taking a random approach to identify potential new antimicrobials,” Quave says. “Focusing on plants used in traditional medicines allows us to hone in quickly on bioactive molecules.”

Previously, the Quave lab had found that the berries of the Brazilian peppertree, a plant used by traditional healers in the Amazon for centuries to treat skin infections and some other ailments, contains a flavone-rich compound that disarms drug-resistant staph bacteria. They had also found that the leaves of the Brazilian peppertree contain PGG, a compound that has shown antibacterial, anticancer and antiviral activities in previous research.

A 2020 study by the Quave lab, for instance, found that PGG inhibited growth of Carbapenem-resistant Acinetobacter baumannii, a bacterium that infects humans and is categorised as one of five urgent threats by the CDC.

The Brazilian peppertree is a member of the poison ivy family. “PGG has popped up repeatedly in our laboratory screens of plant compounds from members of this plant family,” Quave says. “It makes sense that these plants, which thrive in really wet environments, would contain molecules to fight a range of pathogens.”

Experimental results

The Quave lab decided to test whether PGG would show antifungal activity against Candida.

In vitro experiments demonstrated that PGG blocked around 90% of the growth in 12 strains from four species of CandidaC. albicans, multidrug-resistant C. auris and two other multidrug-resistant non-albicans Candida species.

PGG is a large molecule known for its iron-binding properties. The researchers tested the role of this characteristic in the antifungal activity.

“Each PGG molecule can bind up to five iron molecules,” Marquez explains. “When we added more iron to a dish, beyond the sequestering capacity of the PGG molecules, the fungi once again grew normally.”

Dish experiments also showed that PGG was well-tolerated by human kidney, liver and epithelial cells.

“Iron in human cells is generally not free iron,” Marquez says. “It is usually bound to a protein or is sequestered inside enzymes.”

A potential topical treatment

Previous animal studies on PGG have found that the molecule is metabolised quickly and removed from the body. Instead of an internal therapy, the researchers are investigating its potential efficacy as a topical antifungal.

“If a Candida infection breaks out on the skin of a patient where a catheter or other medical instrument is implanted, a topical antifungal might prevent the infection from spreading and entering into the body,” Marquez says.

The researchers will bext test PGG as a topical treatment for fungal skin infections in mice.

Meanwhile, Quave and Marquez have applied for a provisional patent for the use of PGG for the mitigation of fungal infections.

“These are still early days in the research, but another idea that we’re interested in pursuing is the potential use of PGG as a broad-spectrum microbial,” Quave says. “Many infections from acute injuries, such as battlefield wounds, tend to be polymicrobial so PGG could perhaps make a useful topical treatment in these cases.”

Source: Emory University

The Emerging Treatment-resistant Fungus Threat

Professor Rodney E. Rohde, a public health and clinical microbiology expert at Texas State University, warned in article for The Conversation of the growing threat of fungal resistance — a problem drawing much less attention than antibiotic resistance. 

 Athlete’s foot, thrush, ringworm and other ailments are caused by fungi, and some are serious risks to health and life. Among these is Candida auris, a pathogenic fungus. Fungi generally have not caused major disease, so there is a lack of funding in this area and there are limited antifungal agents that can treat C. auris.

Most fungal infections around the world are caused by the genus Candida, particularly the species called Candida albicans. But there are others, including Candida auris, which gets its name ‘auris’, Latin for ear, because it was first identified from an external ear canal discharge in 2009.

Candida normally lives on the skin and inside the body, such as in the mouth, throat, gut and vagina, without causing any problems. It exists as a yeast and is thought of as normal flora, harmless microbes. However when the body is immuno-compromised, these fungi become opportunistic pathogens, something happening around the world with multidrug-resistant C. auris.

The threat of Candida auris

C. auris infections, or fungaemia, have been reported in 30 or more countries. They are often found in the blood, urine, sputum, ear discharge, cerebrospinal fluid and soft tissue, and occur in people of all ages. According to the US Centers for Disease Control, the mortality rate in the US has been reported to be between 30% to 60% in many patients who had other serious illnesses. In a 2018 review of research on the global spread of the fungus, researchers estimated mortality rates of 30% to 70% in C. auris outbreaks among critically ill patients in intensive care.

Recent surgery, diabetes and broad-spectrum antibiotic and antifungal use are risk factors. Furthermore, immuno-compromised patients are at greater risk than those with healthy immune systems.

C. auris can be difficult to identify with conventional microbiological culture techniques, which leads to frequent mis-identification and under recognition. This yeast is also known for its tenacity to easily colonise the human body and environment — including medical devices. People in nursing homes and patients with catheters, on ventilation etc seem to be at highest risk.

The CDC has set C. auris infections at an “urgent” threat level because 90% are resistant to at least one antifungal, 30% to two antifungals, and there are some resistant to all three available classes of antifungals. This multidrug resistance has led to outbreaks in health care settings, especially hospitals and nursing homes, that are extremely difficult to control.

The double threat of COVID and C. auris

For hospitalised COVID patients, antimicrobial-resistant infections may be a particularly devastating risk. The mechanical ventilators often used to treat serious COVID are breeding grounds and highways for entry of environmental microbes like C. auris. Further, according to a September 2020 paper, hospitals in India treating COVID have detected C. auris on surfaces including “bed rails, IV poles, beds, air conditioner ducts, windows and hospital floors.” The researchers termed the fungus a “lurking scourge” amid the COVID pandemic. Termed ‘white fungus’, these fungal infections typically arise a week to 10 days after being in the ICU.

The same authors reported in a November 2020 CDC article that of 596 COVID-confirmed patients in a New Delhi ICU from April 2020 to July 2020, 420 patients required mechanical ventilation. Of these, 15 were infected with candidemia fungal disease and eight of those infected (53%) died. Ten of the 15 patients were infected with C. auris; six of them died (60%).

How to deal with this?

With fewer and fewer antifungal options,  CDC is recommending a focus on preventing C. auris infections. This involves better hand hygiene and improving infection prevention and control in medical care settings, judicious and thoughtful use of antimicrobial medications, and stronger regulation limiting the over-the-counter availability of antibiotics.

Source: The Conversation

Journal information: Anuradha Chowdhary et al, The lurking scourge of multidrug resistant Candida auris in times of COVID-19 pandemic, Journal of Global Antimicrobial Resistance (2020). DOI: 10.1016/j.jgar.2020.06.003