Seasonal and Geographical Impact on the Mycotoxigenicity of Aspergillus and Fusarium Species Isolated from Smallholder Dairy Cattle Feeds and Feedstuffs in Free State and Limpopo Provinces of South Africa

Oluwasola Abayomi Adelusi; Sefater Gbashi; Janet Adeyinka Adebo; Adeola Oluwakemi Aasa; Oluwaseun Mary Oladeji; Glory Kah; Oluwafemi Ayodeji Adebo; Rumbidzai Changwa; Patrick Berka Njobeh

doi:10.3390/toxins15020128

Seasonal and Geographical Impact on the Mycotoxigenicity of Aspergillus and Fusarium Species Isolated from Smallholder Dairy Cattle Feeds and Feedstuffs in Free State and Limpopo Provinces of South Africa

Toxins (Basel). 2023 Feb 4;15(2):128. doi: 10.3390/toxins15020128.

Authors

Oluwasola Abayomi Adelusi¹, Sefater Gbashi¹, Janet Adeyinka Adebo², Adeola Oluwakemi Aasa¹, Oluwaseun Mary Oladeji³, Glory Kah¹, Oluwafemi Ayodeji Adebo⁴, Rumbidzai Changwa¹, Patrick Berka Njobeh¹

Affiliations

¹ Department of Biotechnology and Food Technology, Faculty of Science, Doornfontein Campus, University of Johannesburg, P.O. Box 17011, Johannesburg 2028, South Africa.
² Food Evolution Research Laboratory, School of Hospitality and Tourism, College of Business and Economics, University of Johannesburg, P.O. Box 17011, Johannesburg 2028, South Africa.
³ Department of Biology and Environmental Science, Faculty of Science, Sefako Makgatho Health Sciences University, P.O. Box 139, Pretoria 0204, South Africa.
⁴ Food Innovation Research Group, Department of Biotechnology and Food Technology, Doornfontein Campus, University of Johannesburg, P.O. Box 17011, Johannesburg 2028, South Africa.

Abstract

This study evaluated the impact of seasonal and geographical variations on the toxigenicity of Aspergillus and Fusarium strains previously isolated from smallholder dairy cattle feeds and feedstuffs sampled during summer and winter in the Free State and Limpopo provinces of South Africa (SA). In total, 112 potential toxigenic fungal species were obtained and determined for their capability to produce mycotoxins on solid Czapek Yeast Extract Agar (CYA); followed by liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Our result revealed that 41.96% of the fungal species produced their respective mycotoxins, including aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), and zearalenone (ZEN), with higher levels of AFB₁ (0.22 to 1045.80 µg/kg) and AFB₂ (0.11 to 3.44 µg/kg) produced by fungal species isolated from summer samples than those in winter [(0.69 to 14.44 µg/kg) and (0.21 to 2.26 µg/kg), respectively]. The same pattern was also observed for AFB₁ and AFB₂ in Limpopo (0.43 to 1045.80 µg/kg and 0.13 to 3.44 µg/kg) and Free State (0.22 to 576.14 µg/kg and 0.11 to 2.82 µg/kg), respectively. More so, ZEN concentrations in summer (7.75 to 97.18 µg/kg) were higher than in winter (5.20 to 15.90 µg/kg). A similar observation was also noted for ZEN in Limpopo (7.80 to 97.18 µg/kg) and Free State (5.20 to 15.90 µg/kg). These findings were confirmed via Welch and Brown-Forsythe tests with significantly (p ≤ 0.05) higher mycotoxin levels produced by fungal strains obtained in samples during summer than those in winter. In contrast, the concentrations of mycotoxins produced by the fungal species from both provinces were not significantly (p > 0.05) different.

Keywords: LC-MS/MS; South Africa; dairy cattle feeds; fungal species; mycotoxigenicity; mycotoxins.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animal Feed / analysis
Animals
Aspergillus
Cattle
Chromatography, Liquid
Food Contamination / analysis
Fusarium*
Mycotoxins* / analysis
Seasons
South Africa
Tandem Mass Spectrometry / methods
Zearalenone* / analysis

Substances

Mycotoxins
Zearalenone

Grants and funding

This research was funded by the National Research Foundation (NRF) via the LEAP-Agri 483, Grant number 115579.