Scholarlink

Background <p>The escalating threat of antimicrobial resistance (AMR) in aquaculture presents a significant challenge to the sustainability of fish farming and global health. Excessive and improper use of antibiotics in aquaculture is a primary driver of AMR, particularly in regions like Nigeria, where fish farming is a key sector of aquaculture. This study investigated the antimicrobial capability of Lactic Acid Bacteria (LAB) isolated from the intestines of African Catfish (<i>Clarias gariepinus</i>) in Nigeria as natural alternatives to antibiotics in animal feed. The aim was to assess LAB’s effectiveness against enteric pathogens from African Catfish that demonstrated resistance to multiple antibiotics commonly used in aquaculture.</p> Methodology <p>LAB and enteric pathogens were isolated from the intestines of African Catfish using selective growth media. Phenotypic identification methods, including morphological and biochemical tests, were initially employed, followed by confirmation of the most active strains through 16&#xa0;S rRNA gene sequencing. Additionally, the antibiotic resistance profiles of both LAB and enteric pathogens were established using standard disc diffusion methods. The most resistant pathogens were selected for challenge tests to evaluate the antimicrobial efficacy of the LAB isolates.</p> Results <p>A total of 38 LAB isolates and 30 enteric pathogens were assessed, with 61% of the LAB isolates showing resistance to at least four of the eight antibiotics tested. In contrast, 50% of the enteric pathogens were susceptible to at least six of the antibiotics tested. When the LAB isolates were tested against the most resistant pathogens, which were molecularly identified as <i>Enterobacter cancerogenus FP4C</i> and <i>Enterobacter cloacae FP5A</i>, 48% of the LAB isolates demonstrated significant antimicrobial activity, with inhibition zones measuring ≥ 20&#xa0;mm. DNA sequencing of the most active LAB isolates revealed a diverse range of species, including <i>Weissella confusa</i> (40%), <i>Pediococcus pentosaceus</i> (27%), <i>Lactobacillus reuteri</i> (20%), <i>Lactobacillus murinus</i> (7%), and <i>Lactobacillus vaginalis</i> (7%).</p> Conclusion <p>Our findings demonstrate the diverse LAB species present in the intestines of Nigerian catfish and their invitro antimicrobial effectiveness against resident AMR enteric pathogens. Although these LAB isolates show promise as potential antimicrobial agents, further testing, including in vivo studies and safety assessments, is required to confirm their suitability as probiotics in aquaculture applications.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Antimicrobial activity of lactic acid bacteria isolated from the gut of African catfish (Clarias gariepinus) against multi-drug-resistant resident pathogens

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年7月4日

查看全文
  • Mercy Mayowa Olorunshola,
  • Taiwo Samuel Agidigbi,
  • Bolanle Alake Adeniyi

摘要

Background

The escalating threat of antimicrobial resistance (AMR) in aquaculture presents a significant challenge to the sustainability of fish farming and global health. Excessive and improper use of antibiotics in aquaculture is a primary driver of AMR, particularly in regions like Nigeria, where fish farming is a key sector of aquaculture. This study investigated the antimicrobial capability of Lactic Acid Bacteria (LAB) isolated from the intestines of African Catfish (Clarias gariepinus) in Nigeria as natural alternatives to antibiotics in animal feed. The aim was to assess LAB’s effectiveness against enteric pathogens from African Catfish that demonstrated resistance to multiple antibiotics commonly used in aquaculture.

Methodology

LAB and enteric pathogens were isolated from the intestines of African Catfish using selective growth media. Phenotypic identification methods, including morphological and biochemical tests, were initially employed, followed by confirmation of the most active strains through 16 S rRNA gene sequencing. Additionally, the antibiotic resistance profiles of both LAB and enteric pathogens were established using standard disc diffusion methods. The most resistant pathogens were selected for challenge tests to evaluate the antimicrobial efficacy of the LAB isolates.

Results

A total of 38 LAB isolates and 30 enteric pathogens were assessed, with 61% of the LAB isolates showing resistance to at least four of the eight antibiotics tested. In contrast, 50% of the enteric pathogens were susceptible to at least six of the antibiotics tested. When the LAB isolates were tested against the most resistant pathogens, which were molecularly identified as Enterobacter cancerogenus FP4C and Enterobacter cloacae FP5A, 48% of the LAB isolates demonstrated significant antimicrobial activity, with inhibition zones measuring ≥ 20 mm. DNA sequencing of the most active LAB isolates revealed a diverse range of species, including Weissella confusa (40%), Pediococcus pentosaceus (27%), Lactobacillus reuteri (20%), Lactobacillus murinus (7%), and Lactobacillus vaginalis (7%).

Conclusion

Our findings demonstrate the diverse LAB species present in the intestines of Nigerian catfish and their invitro antimicrobial effectiveness against resident AMR enteric pathogens. Although these LAB isolates show promise as potential antimicrobial agents, further testing, including in vivo studies and safety assessments, is required to confirm their suitability as probiotics in aquaculture applications.