Aims: This study investigates the indoor microbiological air quality of twelve primary schools by characterizing airborne viable bacteria and assessing their antibiotic resistance and biofilm-production ability.Methodology and results: Indoor bacterial density was quantified in twelve primary schools in the Mascara region of Algeria using the settle plate method.Fifty-six bacterial isolates were tested for antibiotic resistance and biofilm formation.Airborne bacteria significantly contaminated all classrooms, with cultivable bacterial concentrations ranging from 3.3 10 2 to 7.6 10 2 CFU/m 3 .The agar diffusion method revealed substantial resistance to penicillin (39.28%), and amoxicillin (25%), and 14.28% of isolates exhibited -lactamase production.A semi-quantitative microplate assay (TCP) showed that 61.53% of the isolates produced biofilms.Molecular analysis identified Enterobacter and Staphylococcus as the dominant genera, with lower proportions of Kocuria, Acinetobacter, Bacillus, Exiguobacterium, and Pseudomonas.Notably, this study reports the first isolation of an Enterobacter hormaechei strain from an indoor school environment. Conclusion, significance and impact of study:The elevated levels of airborne, multidrug-resistant, and biofilmproducing bacteria represent a significant health concern for pupils.Inhalation of these bioaerosols may adversely affect children's health and scholastic performance.
Chentouf et al. (Sun,) studied this question.