Abstract
BackgroundStaphylococci species are the major constituents of infectious bioaerosols, particularly methicillin-resistant Staphylococci (MRS) have serious health impacts. Here, the bacterial burden was quantified, especially prevalence of MRS in bioaerosols collected from indoors of Dr. B.R. Ambedkar Central Library (DBRACL) and Central Laboratory Animal Resources (CLAR) of Jawaharlal Nehru University, New Delhi, India. Air samplings from DBRACL and CLAR were done using the settle plate method and SKC biosampler, respectively.ResultsThis study showed a maximum 6757 CFU/m2/hr of bacterial load in the DBRACL reading room, while unacceptable bacterial loads (> 1000 CFU/m3 of air) at different sites of CLAR. Further, at both the sampling sites the predominance of coagulase negative Staphylococci (CNS) was observed. A total 22 and 35 Staphylococci isolates were isolated from DBRACL and CLAR bioaerosols, respectively. Majority (16/22) of the Staphylococcal isolates from DBRACL belonged to human-associated Staphylococci where S. haemolyticus (5/22) was the most dominating species. However, in CLAR facility centre, animal-associated Staphylococci (19/35) were dominating, where S. xylosus (12/35) was the most dominating species. Further, antibiotic sensitivity tests revealed 41% MRS and 73% multidrug resistant (MDR) among airborne Staphylococci from DBRACL indoor bioaerosols. Similarly, in CLAR facility, approximately, 66% Staphylococci isolates were methicillin resistant, out of which 2 isolates showed high MIC value ≥ 16 μg/mL. Further, we confirmed the presence of 49% multidrug resistant Staphylococci in the indoor air of CLAR facility.ConclusionsThis study suggested that the exposure of workers and students in CLAR to such a high concentration of drug-resistant Staphylococci should not be undermined, as these bacterial concentrations are the direct representative of inhalable particulate matter (PM2.5) as per collection procedure. Simultaneously, passive sampling from DBRACL assessed the risks due to microbial contamination in particle agglomerates, which may deposit on the crucial surfaces such as wounds/ cuts or on the frequently used items.
Highlights
Staphylococci species are the major constituents of infectious bioaerosols, methicillinresistant Staphylococci (MRS) have serious health impacts
Using the active sampling in Central Laboratory Animal Resources (CLAR) facility, we evaluated an inhalable exposure of humans and animals to microbial contamination, where we observed an unacceptable exposure (≥ 1100 to as much as 6360 Colony forming unit (CFU)/ m3) of total airborne bacteria at all the indoor locations of animal facility (Fig. 2a)
Overall, this study identified that both the facilities contained an unacceptable airborne Staphylococcal loads with a huge proportion of MR-coagulase negative Staphylococci (CNS) and Multidrug resistant- coagulase negative Staphylococci (MDR-CNS), which could affect human health, especially people with compromised immunity
Summary
Staphylococci species are the major constituents of infectious bioaerosols, methicillinresistant Staphylococci (MRS) have serious health impacts. Results: This study showed a maximum 6757 CFU/m2/hr of bacterial load in the DBRACL reading room, while unacceptable bacterial loads (> 1000 CFU/m3 of air) at different sites of CLAR At both the sampling sites the predominance of coagulase negative Staphylococci (CNS) was observed. The increasing microbiological air pollution that is caused by the contaminated bioaerosols, has huge impact on the human health [1, 2] Both the culturable and non-culturable bioaerosols can act as an important reservoir for antimicrobial resistance genes (ARG) by virtue of their free mobility, putting people with compromised immunity at risk of catching infections [3,4,5]. Of total 47 Staphylococcal species, 7 (1 CPS and 6 CNS) belong to human-associated Staphylococci, which colonize in humans, these are; S. aureus, S. capitis, S. caprae, S. epidermidis, S. haemolyticus, S. hominis, S. lugdunensis, S. saprophyticus, and S. warneri [12]. It is very difficult to eradicate CNS infections due to their species diversity leading to different anti-biograms and minimum inhibitory concentration (MIC) breakpoints [12, 17]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
