EFFECTS OF MUSICAL SOUNDS ON THE GROWTH AND SUSCEPTIBILITY OF SOME PATHOGENIC MICROORGANISMS TO SOME SELECTED ANTIBIOTICS

Abstract

Four musical selections of varied characteristics were used in this exploratory work to determine the effects of different kinds of music (audible sound wave) on the susceptibility pattern of selected microorganisms to selected antibiotics. A total of nine (9) bacterial isolates and five (5) fungal isolates were used in this study. The experiment was conducted by dividing stock cultures of test organisms into two groups. One group serving as the control was placed in a sound-free box, the other group was further subdivided and each group subjected to the respective test music selections played at the sound volume of 50dB and frequencies 2, 4 and 6 kHz. Differences between control and test groups were compared for susceptibility, growth rate of organisms, death rate and membrane leakage. The susceptibility patterns of bacterial isolates except Enterobacter aerogenes, Proteus vulgaris, Staphylococcus aureus, Escherichia coli and Streptococcus pneumonia remained the same under test and control conditions. All the music selections played at 2 kHz induced slight changes in the susceptibilities of E. aerogenes, P. vulgaris and S. Pneumoniae to ciprofloxacin and Sparfloxacin, Gentamycin and septrin respectively. Playing at 6 kHz, all music selections increased the susceptibility of S.aureus to chloramphenicol (from 16mm to 18mm) while all but soul music increased susceptibility of E.coli to Streptomycin and sparfloxacin with zone diameter increasing from 12mm to values ranging from 15mm to 17mm. Susceptibilities of fungal isolates were almost constant for both test and control conditions while only the soul music played at 6 kHz increased the susceptibility of A.flavus to fluconazole. This is shown by a rise in the percentage inhibition of A.flavus by fluconazole from 63% to 72%. The soul music played at 2 kHz caused a significant increase (p≤0.05) in growths of P.vulgaris; E.aerogenes; E.coli; S.typhi and S.aureus by 29.5%; 54.2%; 29.2%; 37.5% and 29% respectively when compared with the control groups, while rock music played at frequencies of 4 and 6 kHz as well as soul music played at 6 kHz reduced the growth of Aspergillus flavus from 9.17×105 SFU/ml (control) to values ranging from 7.14×105 SFU/ml to 7.77×105 SFU/ml. Though the death rates of fungal isolates were not significantly affected by exposure to the musical selections (at p≥0.05), treatment with the rock music significantly increased the death rates of Bacillus cereus, S.aureus, E.coli and E.aerogenes. Playing rock music at 6 kHz enhanced death rate of these bacterial isolates except E.aerogenes whose death rate was increased by rock music playing at 4 kHz. Increase in the leakage of sodium (Na+) and potassium (K+) ions due to treatment with some of the musical selections was found only in antibiotic-treated cultures of Candida albicans and A.flavus. Specifically, rock music played at 6 kHz led to a significant increase (p≤0.05) in the amount of both Na+ and K+ leaked from C.albicans but only Na+ in A.flavus.