Co-occurrence of heavy metals and antibiotics resistance in bacteria isolated from metal-polluted soil

Joseph, Oluwarotimi John; Ogunleye, Gbemisola Elizabeth; Oyinlola, Kubrat Abiola; Balogun, Augustina I.; Olumeko, Damilola Tolulope

doi:2023.38.4.e2023024

Environ Anal Health Toxicol > Volume 38:2023 > Article

Original Article

Published online November 17, 2023

Environmental Analysis Health and Toxicology 2023;38(4):e2023024-0. doi: https://doi.org/10.5620/eaht.2023024

Co-occurrence of heavy metals and antibiotics resistance in bacteria isolated from metal-polluted soil

Oluwarotimi John Joseph¹

, Gbemisola Elizabeth Ogunleye¹

, Kubrat Abiola Oyinlola²

, Augustina I. Balogun¹, Damilola Tolulope Olumeko¹

¹Department of Biological Sciences, Faculty of Applied Sciences, KolaDaisi University, Ibadan, Nigeria
²Department of Microbiology, Faculty of Science, University of Ibadan, Ibadan, Nigeria

Corresponding Author: Oluwarotimi John Joseph ,Email: oluwarotimi.joseph@koladaisiuniversity.edu.ng

Received: August 1, 2023; Accepted: October 20, 2023.

ABSTRACT

The indiscriminate deposition of metal-containing substances into the environment contributes significantly to high concentrations of metals in the soil resulting in resistance to metals and consequentially to antibiotics by inherent microbes which may eventually spread to other pathogenic microbes thereby elevating disease burden due to antibiotic resistance. The study aimed at determining the co-occurrence of resistance of bacteria isolated from metal-contaminated soil to heavy metals and subsequently, antibiotics. Metal-tolerant bacteria were randomly isolated from top soils from a battery waste site using the pour plate method. Selected isolates were identified using biochemical tests, then, subjected to elevating supplemented concentrations of different metal salts at 100-500 μg/mL to determine the minimum inhibitory concentration. Isolates tolerant to minimum three metals up to 400 μg/mL were subjected to Sulfamethoxazole-trimethoprim (25 μg), Imipenem (10 μg), Amoxicillin (30 μg), Ciprofloxacin (10 μg) and Tigecycline (15 μg) and observations interpreted using the guiding principle of the Clinical and Laboratory Standards Institute. Metal concentrations in the soils exceeded permissible limits. In total, 16 isolates were selected and identified as Proteus sp. (1), Pseudomonas spp. (5), Enterobacter spp. (2), Klebsiella spp. (2), Escherichia spp. (3), Raoultella spp. (2) and Rahnella sp. (1). Thirteen (81.25 %) of all isolates showed multi-resistance to the metals and seven exhibited multidrug-resistance, with 4 (57.1 %) showing resistance to three different classes of antibiotics and 3 (42.9 %) showed resistance to four antibiotic classes. Heavy metal-tolerant bacteria isolated from this study possess co-selection potentials as they showed resistance to different metals and antibiotics classes which is a concern to public health.

Keywords: Heavy metals, Antibiotics, Antibiotic resistance, Metal resistance, Pseudomonas sp