Pathogenic Molds and Multidrug-Resistant Respiratory Bacterial Pathogens Isolated From Air Samples Collected From a Clinic in Johannesburg, South Africa

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 of 2025, air samples were collected within a Johannesburg clinic directly onto 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 categorized as pathogens or opportunistic pathogens. All Gram-negative (n = 77; 100%) and almost all Gram-positive (n = 52/54; 96.30%) isolates were categorized 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 characterized 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 program at the clinic in question be reviewed and that monitoring continue.