Listeria Contamination in Fresh Fruits Identified in Nigerian Markets

Strategic Insights -

A new study published in The Microbe reveals that listeria contamination in fresh fruits is a significant issue in Nigeria, with a substantial portion of fruits examined found to be contaminated with the bacteria. The study, conducted by researchers at the Federal University of Agriculture in Ogun State, Nigeria, analyzed 270 fruits purchased from thirty markets in Southwest Nigeria and found that 100% of the fruits contained Listeria spp., with 28 strains identified as pathogenic and 9 as non-pathogenic. The researchers also detected antimicrobial resistance and virulence genes in the Listeria strains, with the highest prevalence of resistance found in fruits from Balogun, Agege, and Lekki in Lagos state.

Key Takeaways:

  • 270 fruits were analyzed from thirty markets in Southwest Nigeria, with 100% of the fruits found to contain Listeria spp.
  • 28 Listeria strains were identified as pathogenic, comprising 6 L. monocytogenes, 5 L. ivanovii, 8 L. seegligeri, and 9 non-pathogenic strains.
  • The highest prevalence of antimicrobial resistance was found in fruits from Balogun (60%).
  • The study detected virulence genes, including prfA, plcA, and plcB, in Listeria monocytogenes, L. ivanovii, and L. seegligeri.
  • The researchers concluded that fruits can be a versatile route for diverse virulent-resistant Listeria strains, causing constant listeriosis and spoilage.

Statistics:

  • 270 fruits analyzed from thirty markets in Southwest Nigeria.
  • 100% of the fruits contained Listeria spp.
  • 28 pathogenic Listeria strains identified.
  • 9 non-pathogenic Listeria strains identified.
  • 6 Listeria monocytogenes strains detected.
  • 5 Listeria ivanovii strains detected.
  • 8 Listeria seegligeri strains detected.
  • 60% of fruits from Balogun contained antimicrobial-resistant Listeria strains.

Sources:

  • Prevalence, persistence and diversity of Listeria strains with antimicrobial resistance and virulence genes from fresh fruits in Southwest Nigeria. The Microbe, 2025, 7():100286.
  • https://doi-org.sdpl.idm.oclc.org/10.1016/j.microb.2025.100286 (free version available)