Virulence Characteristics and Public Health Significance of Bacteria Isolated from University of Ibadan Libraries

Abstract

Aims: To verify the possibility of isolating virulent microorganisms from books and indoor air in University of Ibadan libraries and to investigation the virulent characteristics and antibiotics sensitivities of these microorganisms and their public health significance. Study Design: The study made use of a purposive sampling method. Place and Duration: Department of Microbiology, University of Ibadan, Ibadan between August, 2014 and February, 2015. Methodology: Forty swab samples from books and 20 indoor air samples were collected and analyzed. The settle plate method was used to collect the air sample while book surfaces were swabbed using sterile swabs. Results: The mean bacterial count in the indoor ranged from 0.23 x 103± 0.065 Colony Forming Unit/m3 to 1.99 x 103 ± 0.655 Colony Forming Unit (cfu)/m3 while that of swab samples ranged from 5.83 x 104 ± 0.0247 cfu/ml to 1.32 x 104 ± 0.0283 cfu/ml. Some of the bacteria isolated were: Bacillus subtilis, B. cereus, B. megaterium, B. pumilus, Staphylococcus aureus, S. arlattae, S. chonii, S. haemolyticus S. muscae, Proteus mirabilis, Micrococcus luteus, M. carouselicus, Yersinia enterolitica, Erwinia mallotivora, Klebsiella pneumoniae, Serratia marcenscens, Pseudomonas aeruginosa and Providencia sp. Exactly 62.5% of the isolates were susceptible to ciprofloxacin, 52.5% were susceptible to Trimethoprim/sulfamethoxazole. The isolates were mostly resistant to Tetracycline (75%). Virulence test results showed that most isolates were positive to DNase (83.3%) and Haemolysin (75%) tests, while 50% positive to Lecithinase test. Only 16.7% of the isolates were positive to coagulase test. Staphylococcus aureus and Staphylococcus haemolyticus were isolates that survived the acid liability test. Conclusion: Bacteria of public health concern were isolated and the ability of any of them to show multiple antibiotic resistances, survive at low pH, produces three or more virulent factors was considered a possibility of pathogenicity of that organism.