Isolation of microorganisms from infected onions (Allium cepa) popularly consumed by low income earners in Ibadan, Nigeria

Salami O. O., Ayanda O. E., Aluko O. I., Abimbola O. T. and Obero J. O.

Microbiology Research International
Published: August 16 2019
Volume 7, Issue 3
Pages 17-23
DOI: https://doi.org/10.30918/MRI.73.19.023

Abstract

Samples of three (3) different varieties of infected onion bulbs were collected from different locations at Oja-oba, Muslim, Oke-ado and Bode markets of Ibadan. Isolation of microorganisms from infected onions (Allium cepa) was carried out. The results revealed that the infected onion bulbs were associated with Escherichia coli, Klebsiella sp., Salmonella sp., Proteus sp., Aspergillus niger, Aspergillus flavus, Rhizopus stolonifer and Aspergillus fumigatus. It was also observed that the market where samples were collected and the variety of onions have no significant effect on the level of bacterial infestation. The mean total bacteria count ranges from 2.2 × 10³ to 8.5 × 10³. Furthermore, the market where samples were obtained and types of onions had no significant effect on the fungal infestation level. The level of infestation ranges from 1.1 × 10¹ to 3.1 × 10¹. E. coli had the lowest bacterial prevalence of 8.3% in the study area when compared to Klebsiella sp. (33.3%), Proteus sp. (30.6%) and Salmonella sp. (27.8%). Aspergillus niger had the highest fungal prevalence of 44.8% while Aspergillus flavus, Aspergillus fumigatus and Rhizopus stolonifer had prevalence of 26.9, 14.9 and 13.4% respectively. It shows that the different varieties of onions purchased at the selected markets in Ibadan, Oyo State contained different pathogenic microorganisms. Adequate care should be taken in processing onions (Allium cepa) to prevent food poisoning.

Keywords: Markets, low income earners, infected onions, microorganism.

Full Text PDF