Assessment of Airborne Extended Spectrum β-Lactamase Producing Enterobacteriaceae Isolates from Motor Parks in Benin City, Nigeria

Aim: The study was aimed at assessing airborne bacteria and extended spectrum β-lactamase producing Enterobacteriaceae isolated from the motor parks in Benin City.

Methodology: Airborne bacteria samples were collected in the motor parks (Central, Ugbowo, Agip, 19th Street, and Ekosodin Park), in Benin City using the settled plate method on Nutrient and MacConkey agar. Temperature, relative humidity, and airborne bacteria of the different parks were determined. The bacterial isolates were identified using phenotypic method. The antibiotic susceptibility profile was investigated by the disc diffusion method. The Enterobacteriaceae isolates were screened for Extended-spectrum β-lactamase (ESBL) production potentials. Virulence factor analysis and detection of ESBL genes (TEM, CTX-M, SHV, and OXA) were carried out on the selected ESBL producers.

Results: The relative humidity recorded at the parks at the point of agar plate exposure ranged from 82 ̶ 90%. The airborne heterotrophic bacterial and coliform counts from the motor parks ranged from 9.50±0.63 × 102 ̶ 1.18±0.02 ×103 cfu/m3 and 2,48±0.41×102 ̶ 3.30±0.41×102 cfu/m3 respectively. The identified Enterobacteriaceae were Citrobacter freundii, Serratia marcescens, Citrobacter koseri, Klebsiella pneumoniae, Morganella morganii, Klebsiella oxytoca, Shigella dysenteriae, Proteus mirabilis, Escherichia coli, Enterobacter cloacae and Citrobacter diversus. The isolate with highest frequency of occurrence was E. coli with values of 30.48 %. The isolate K. pneumoniae had the highest MAR index of 0.8. The isolate S. marcescens had the highest virulent factor of 60% and possessed all the ESBL genes detected.

Conclusion: Strong infection control measures should be put in place because more ESBL-producing Enterobacteriaceae have emerged in the surroundings of specific parks in Benin City.