High levels of antibiotic-resistant superbugs have been found in both indoor and outdoor environments in Delhi, raising concerns for public health. A study conducted by researchers at Jawaharlal Nehru University focused on the prevalence and diversity of staphylococci, including methicillin-resistant staphylococci (MRS), in bioaerosols across various urban settings in Delhi, India. The air samples collected showed significantly elevated staphylococcal loads, surpassing the WHO’s recommended limit for microbial exposure.
The research revealed seasonal variations in airborne MRS levels, peaking during winter and decreasing with monsoon rains. The study identified eight staphylococcal species, with Staphylococcus epidermidis and Staphylococcus arlettae being the most common human- and animal-associated species, respectively. Alarmingly, 73% of the MRS isolates exhibited multidrug resistance (MDR), showing resistance to various commonly used antibiotics such as macrolides and beta-lactams.
Genotypic analysis confirmed the presence of antibiotic resistance genes (ARGs) among airborne MRS, encoding resistance to multiple antibiotic classes. Notably, a significant proportion of MDR isolates carried the mecA gene, responsible for methicillin resistance. The researchers emphasized the urgent need for comprehensive environmental surveillance of antimicrobial resistance (AMR) to develop effective strategies for mitigation.
The study underscores the importance of monitoring and reporting on environmental AMR, including both antibiotic-resistant bacteria and their associated genetic markers. The researchers stressed the necessity of such efforts to accurately assess the extent of the AMR threat and to guide the development of integrated action plans to address the growing challenges posed by AMR in urban settings.
