Multidrug resistance in bacteria isolated from indoor air of female hostels in a tertiary institution

Objective: To determine the occurrence of multidrug resistant bacteria from the indoor environment of female hostels in a tertiary institution in order to provide epidemiological data. Methods: The bacterial quality of the three female hostels was evaluated using the settle plate method, where Petri dishes containing different types of culture media were opened in the rooms. Isolated bacteria were identified using standard microbiological procedures. Using disc diffusion method, the antibiogram of the isolates was determined and based on this, the multiple antibiotics resistance index was also determined. Results: The total heterotrophic colony forming units (CFU) for Hall A ranged from 2.09 x102 to 1.73 x103 CFU/m3 while that of Hall B ranged from 4.71 x102 to 1.10 x103 CFU/m3 and a statistically significant difference between the counts of both halls was observed (P=0.04). Microorganisms isolated included Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Corynebacterium sp., Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. All the isolates exhibited multidrug resistance to amoxycillin-clavulanic acid, cefuroxime and ceftriaxone. Proteus mirabilis, Klebsiella pneumoniae and Corynebacterium sp. had the least multiple antibiotic resistance index with 0.2 while Staphylococcus aureus had the highest with 0.8. Conclusions: Female university hostels may become sources of exchange of microorganisms, especially in overcrowded rooms. A large percentage of isolates were multidrug resistant which could pose difficulty and increased cost of treatment of their resulting infections. Regular surveillance and control of the agents that encourage the growth of these bacteria present in indoor air is needed.