Latest News Archive

Please select Category, Year, and then Month to display items

UFS researchers investigate deadly fungi affecting millions in South Africa

12 June 2023 | Story André Damons | Photo Sonia Small

Prof Carolina Pohl-Albertyn — Prof Carlien Pohl-Albertyn, National Research Forum (NRF) SARChI Research Chair in Pathogenic Yeasts, leads the research team that is working on various research projects relating to fungi casing yeast.

Fungal infections affect more than one billion people each year, of which more than 150 million cases are severe and life-threatening, causing 1.7 million deaths a year. In South Africa it is estimated that diseases caused by fungal infections total more than three million cases a year. These figures are especially shocking given that prior to 1980, fungal infections were not a major health problem. The WHO has recently published a list of priority pathogens in which fungi are classified in critical, high- and medium- priority groups. Candida species are found in all three levels and Cryptococcus species in critical and medium groups,” says Prof Pohl-Albertyn.

It is for these reasons that researchers in the Department of Microbiology and Biochemistry at the University of the Free State (UFS) are working on various research projects investigating new treatment options beyond the established antifungals. Prof Carlien Pohl-Albertyn, National Research Forum (NRF) SARChI Research Chair in Pathogenic Yeasts, leads the team that is working on various research projects relating to fungi casing yeast.

Multidrug-resistant yeast

One of the yeasts being researched is Candida auris – a multidrug-resistant yeast that can cause severe infections in humans, particularly in people who are hospitalised or have weakened immune systems. C. auris was first identified in 2009 in Japan and has since been reported in over 49 countries.

According to Prof Pohl-Albertyn, C. auris is of concern because it is often resistant to multiple antifungal drugs, making it difficult to treat. In addition, it can survive on surfaces in healthcare settings, which can contribute to its spread between patients, causing outbreaks in hospitals. “Due to its multidrug resistance and potential for transmission, C. auris has been designated by the Centers for Disease Control and Prevention (CDC) as a serious global health threat and listed as the second most critical fungal pathogen in the World Health Organisation (WHO) fungal critical priority group.

“C. auris possesses virulence factors such as increased thermotolerance, high salinity tolerance, biofilm formation, and extra cellular enzyme secretion, which are the major contributing factors to its multidrug resistance profile and virulence. Even though C. auris has a variety of virulence factors that it employs against its human host to develop an infection, its virulence mechanisms remain unclear,” says Prof Pohl-Albertyn.

Therefore, several research projects investigate this pathogenic yeast. All of them started with the development of CRISP-Cas9 gene editing tools for this yeast, in order to be able to delete specific genes in this yeast to study their roles. These tools are also constantly being improved for greater efficiency by students under the supervision of Prof Koos Albertyn. Two current projects deal with the function of specific secreted enzymes in the virulence of C. auris.

Environmental yeast

Another yeast being researched, under the supervision of Prof Olihile Sebolai, is Cryptococcus neoformans, an environmental yeast found in trees and soil contaminated with bird droppings. Moreover, it can be airborne and when inhaled it lodges in the lungs (in alveoli) and can cause primary lung infection, explains Prof Pohl-Albertyn.

Cryptococcus neoformans causes AIDS-defining illnesses in people living with HIV/AIDS. To the point, it was not surprising when the WHO declared it as the first critical fungal pathogen of concern. Dissemination to other organs has been reported where it crosses the epithelium barrier by secreting proteases (a class of enzymes that break down proteins in the host) that compromise the tight junctions between the epithelial cells.

The current projects investigate the interaction between the proteases secreted by C. neoformans and co-infecting viruses, such as SARS-CoV-2 and influenza. The SARS-CoV-2 virus is activated by proteases in the host and proteases also help the influenza virus to enter and infect the host cells. Since the host proteases are similar to those secreted by C. neoformans, these projects are focused on determining if the yeast proteases can also help the viruses to cause infection. This project is also extended to study Candida albicans proteases as this is also a common co-infecting yeast in COVID-19 patients (for more detail on C. albicans).

Another project looks at the application of plants as sources for novel drugs against C. neoformans. This is important since 75-80% of African and Asian populations still rely on traditional or complementary/alternative medicines for their primary health-care needs. Coupled to this, modern medicines have become increasingly expensive and thus inaccessible to many in developing countries. Moreover, there is a shift to more “organic” and “vegan” lifestyles as well as the use of herbal medicines to prevent or manage the development of certain diseases.

Yeast contaminated water

“Considering the severity of invasive fungal infection, it is important to study the dissemination and proliferation of various pathogenic or potentially pathogenic fungal species in our surrounding environments. It is crucial to identify major vectors that aid in the spread of pathogenic yeast to prevent infections in susceptible individuals, which mainly include immunocompromised or immunosuppressed individuals.

“Candida, Cryptococcus and Rhodotorula species are commonly found in a variety of water sources with which humans are in frequent contact through daily activities like bathing, washing of clothes and cooking. This recent information further warrants the investigation into the possibility that fungal infections may occur through contact with yeast contaminated water,” concludes Prof Pohl-Albertyn.

She says it is thus important to investigate the presence and antifungal susceptibility of yeast found in water as well as to identify ways to monitor potential fungal outbreaks, possibly through wastewater surveillance. The research aims to identify potentially pathogenic yeast species as well as to quantify levels of azole, specifically fluconazole, in wastewater. In addition, the fluconazole susceptibility of these isolates will be assessed in an attempt to link azole pollution of the environment to antifungal drug resistance development.

News Archive

Bloemfontein's quality of tap water compares very favourably with bottled water

2009-08-04

The quality of the drinking water of five suburbs in Bloemfontein is at least as good as or better than bottled water. This is the result of a standard and chemical bacterial analysis done by the University of the Free State’s (UFS) Centre for Environmental Management in collaboration with the Institute for Groundwater Studies (IGS).

Five samples were taken from tap water sources in the suburbs of Universitas, Brandwag, Bain’s Vlei, Langenhoven Park and Bayswater and 15 samples were taken of different brands of still and unflavoured bottled water. The samples were analysed at the laboratory of the IGS, while the interpretation of the analysis was done by the Centre for Environmental Management.

“We wanted to evaluate the difference in quality for human consumption between tap water and that of the different brands of bottled water,” said Prof. Maitland Seaman, Head of the Centre for Environmental Management.

“With the exception of two samples produced by multinational companies at their plants in South Africa, the different brands of bottled water used for the study were produced by South African companies, including a local small-scale Bloemfontein producer,” said Prof. Seaman.

According to the labels, the sources of the water vary from pure spring water, to partial reverse osmosis (as an aid to standardise salt, i.e. mineral, content), to only reverse osmosis (to remove salts). (Reverse osmosis is a process in which water is forced under pressure through a pipe with minute pores through which water passes but no – or very low concentrations of – salts pass.)

According to Prof. Seaman, the analysis revealed some interesting findings, such as:

• It is generally accepted that drinking water should have an acceptable level of salt content, as the body needs salts. Most mineral contents were relatively higher in the tap water samples than the bottled water samples and were very much within the acceptable range of drinkable water quality. One of the bottled samples, however, had a very low mineral content, as the water was produced by reverse osmosis, as stated on the bottle. While reverse osmosis is used by various producers, most producers use it as an aid, not as a single method to remove nearly all the salts. Drinking only such water over a prolonged period may probably have a negative effect on the human physiology.

• The pH values of the tap water samples (8,12–8,40) were found to be slightly higher (slightly alkaline), like in all south-eastern Free State rivers (from where the water is sourced) than the pH of most of the bottled water samples, most of which are sourced and/or treated in other areas. Two brands of bottled water were found to have relatively low pH levels (both 4,5, i.e. acidic) as indicated on their bottles and as confirmed by the IGS analysis. The health implication of this range of pH is not significant.

• The analysis showed differences in the mineral content given on the labels of most of the water bottles compared to that found by IGS analysis. The possibility of seasonal fluctuation in content, depending on various factors, is expected and most of the bottling companies also indicate this on their labels. What was a rather interesting finding was that two pairs of bottled water brands claimed exactly the same mineral content but appeared under different brand names and were also priced differently. In each case, one of the pair was a well-known house brand, and the other obviously the original producer. In one of these paired cases, the house brand stated that the water was spring water, while the other (identical) “original” brand stated that it was spring water treated by reverse osmosis and oxygen-enriched.

• Nitrate (NO3) levels were uniformly low except in one bottled sample, suggesting a low (non-threatening) level of organic pollution in the source water. Otherwise, none of the water showed any sign of pollution.

• The bacterial analysis confirmed the absence of any traces of coliforms or E.coli in any of the samples, as was also indicated by the bottling companies. This is very reassuring. What is not known is how all these waters were sterilised, which could be anything from irradiation to chlorine or ozone treatment.

• The price of the different brands of bottled water, each containing 500 ml of still water, ranged between R3,99 and R8,99, with R5,03 being the average price. A comparison between the least expensive and the most expensive bottles of water indicated no significant difference in quality. In fact, discrepancies were observed in the most expensive bottle in that the amount of Calcium (Ca) claimed to be present in it was found to be significantly different from what the analysis indicated (29,6 mg/l versus 0,92 mg/l). The alkalinity (CaCO3 mg/l) indicated on the bottle was also found to differ considerably (83 mg/l versus 9,4 mg/l). The concentration of Total Dissolved Salts (TDS) was not given on the product.

“The preference for bottled water as compared to Bloemfontein’s tap water from a qualitative perspective as well as the price discrepancy is unjustifiable. The environmental footprint of bottled water is also large. Sourcing, treating, bottling, packaging and transporting, to mention but a few of the steps involved in the processing of bottled water, entail a huge carbon footprint, as well as a large water footprint, because it also requires water for treating and rinsing to process bottled water,” said Prof. Seaman.

Media Release
Lacea Loader
Deputy Director: Media Liaison
Tel: 051 401 2584
Cell: 083 645 2454
E-mail: loaderl.stg@ufs.ac.za
3 August 2009

Back

Economic and Management Sciences

Education

Health Sciences

The Humanities

Law

Natural and Agricultural Sciences

Theology and Religion

Open Distance Learning

Business School

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept