Experts have sounded the alarm after finding multidrug-resistant bacteria, including those resistant to medicines for serious infections, in the air at a Johannesburg clinic, calling for mandatory routine air quality monitoring, reports TimesLIVE.
The study – published in the journal Indoor Air – by University of Johannesburg researchers, found that all the Gram-negative bacteria tested and 96.3% of the Gram-positive bacteria were resistant to multiple types of antibiotics.
The scientists had looked at a clinic in a crowded, high-rise part of central Johannesburg. Air samples were taken in 40 areas, including treatment rooms, passages, reception areas and bathrooms, in the early mornings of February 2025 and March 2025, before the clinic began its daily work.
The researchers also grew 77 moulds from the clinic air. Of those, 22 were different enough to be identified by DNA testing, with the teams finding that all but three of the mould species were pathogens or opportunistic pathogens, meaning they can cause illness, especially in people with weak immune systems.
Several are also signs of damp in a building.
Dr Lee Heine, the lead author of the study and a researcher at UJ’s Water and Health Research Centre, said the findings were particularly concerning given South Africa’s high rates of HIV and TB, increasing the risk of lower respiratory tract infections (LRIs) caused by these bacteria.
Infections like bronchitis, bronchiolitis and pneumonia can be life-threatening, particularly for people whose immune systems are weakened.
“All of these infections can be fatal,” she added. “This is because ESKAPE (Enterococcus faecium, Staphylococcus aureus [including MRSA], Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species, as well as Escherichia coli) bacteria tend to be multidrug-resistant or even extensively drug-resistant.
“If patients are already immunocompromised, then the risk of death from pneumonia caused by a multidrug-resistant strain of one of these bacteria increases, as they are likely to spread to the bloodstream and cause sepsis.”
The researchers tested bacteria belonging to the ESKAPE group, which are associated with healthcare-related infections and are known for their ability to resist antibiotics.
The study found resistance to several antibiotics commonly used as first-line treatments.
Among the Gram-negative bacteria tested, 85.7% were resistant to cefuroxime, while 67.5% were resistant to ceftazidime. Resistance was also found to more advanced antibiotics. About 31.2% of the bacteria tested were resistant to ertapenem, while 26% were resistant to meropenem.
The researchers classified 3.9% of the Gram-negative bacteria as extensively drug-resistant, meaning they were resistant to antibiotics across all but one or two categories of treatment.
This leaves doctors with fewer options when treating infections caused by these bacteria.
The study also raised concern about Staphylococcus aureus, a bacterium that can cause infections ranging from skin infections to more serious illnesses. Heine said the bacterium could spread easily between people.
“Worldwide, 10% of people are carriers of S. aureus in their nasal passages or armpits,” she said.
She said healthcare workers identified as carriers needed appropriate treatment to clear methicillin-resistant Staphylococcus aureus (MRSA) from their bodies before returning to contact with patients.
In a related study, Heine and UJ Water and Health Research Centre director Professor Tobias Barnard identified antibiotic-resistant ESKAPE bacteria in the neonatal intensive care unit of a public hospital in the same city. The researchers collected surface swabs from incubators and handwash samples from nurses, doctors, cleaners and clerks working in the unit.
More than 85% of the ESKAPE bacteria identified were classified as multidrug-resistant, highlighting concerns about infections among vulnerable patients, including newborn babies whose immune systems are still developing.
“Using antibiotics to treat infection relies on an intact immune system. The body works with antibiotics to eliminate bacteria. Without an intact immune system, treatment can be prolonged or unsuccessful,” she said.
The researchers also pointed to unreliable water supplies as a challenge for healthcare facilities, as water shortages can affect disinfection and infection prevention measures. They said antimicrobial resistance was a growing problem in South Africa and globally.
“Antimicrobial resistance (AMR) is increasing for all bacteria in South Africa and globally, with AMR bacteria thriving in hospital and clinics,” said Heine.
The researchers said guidelines existed for acceptable levels of bacteria in water and on surfaces in certain settings, but comparable standards for airborne bacteria and fungi in indoor environments were lacking.
Heine called for air quality monitoring to become a routine part of infection prevention and control in healthcare facilities. “There are no stipulated allowable number of respiratory pathogens for a given volume of air. Monitoring bacterial and fungal air quality should be mandatory in clinics and hospitals.
“Routine air quality monitoring needs to be added to their infection prevention and control protocols.”
The researchers cautioned that the study was conducted at a single clinic, with samples collected over two months in 2025. The findings therefore cannot be assumed to reflect conditions at all facilities.
They also said the presence of resistant bacteria in the air showed a potential source of exposure but did not establish that the bacteria had directly infected patients.
Study details
Pathogenic Moulds and Multidrug-Resistant Respiratory Bacterial Pathogens Isolated From Air Samples Collected From a Clinic in Johannesburg, South Africa
Lee Heine, Robyn Theresa Dodds, Atheesha Singh.
Published in Indoor Air on 12 September 2026
Abstract
Background
Poor air quality contributes to the global burden of respiratory disease, with both bacteria and fungi contributing to the number of deaths associated with community- and healthcare-associated infections, especially those caused by antimicrobial-resistant microbes.
Methods
During February and March 2025, air samples were collected within a Johannesburg clinic directly on to Brilliance Escherichia coli/Coliform Selective, MacConkey Agar, and Potato Dextrose Agar (Oxoid, United Kingdom), which were incubated at 37°C and 32°C, respectively. Resulting bacterial isolates were identified and subjected to antimicrobial susceptibility testing using the Vitek 2 compact system (BioMérieux Inc., France), and unique fungal isolates were identified using polymerase chain reaction amplification of internal transcribed spacer regions and subsequent sequencing.
Results
After identification, all but three fungal isolates were categorised as pathogens or opportunistic pathogens. All Gram-negative (n = 77; 100%) and almost all Gram-positive (n = 52/54; 96.30%) isolates were categorised as multidrug-resistant. Significant proportions of both Gram-negative and Gram-positive isolates, including members of the ESKAPEE group of pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species, and E. coli), were found to be resistant to antimicrobials used as first-line treatments for respiratory and other infections and antimicrobials of last resort such as colistin and vancomycin.
Conclusion
Almost all microbes identified and characterised in the present study pose a significant risk of infection and a source of spread of antimicrobial resistance. It is, therefore, recommended that the infection prevention and control programme at the clinic in question be reviewed and that monitoring continue.
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