Anti-invasion activities of heat-killed lactic acid bacteria isolates against Salmonella enterica serovar Typhimurium

• Published in: IRANIAN JOURNAL OF MICROBIOLOGY
• Main Authors: Adzuan, Anis Syahirah Saifor; Mohamad, Sharifah Aminah Syed; Iberahim, Rashidah; Kamal, Noor Nadia Syahira Mohd; Abd Mutalib, Nurliana; Hasbullah, Nur Intan; Alsaydi, Muneer; Hasan, Nor'aishah; Oon, Low Kheng; Ajibola, Olaide Olawunmi; Alias, Rozila; Mustakim, Maimunah; Rambely, Azlin Sham; Mohamed, Emida; Pourmand, Mohammad Reza
• Format: Article
• Language: English
• Published: UNIV MEDICAL SCIENCES-DANISHGAH-I ULUM-I PIZISHKI-I TIHRAN 2024
• Subjects: Microbiology
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-recordWOS:001374425800001
• ISSN: 2008-3289; 2008-4447

Background and Objectives: The most common cause of severe foodborne salmonellosis is S. Typhimurium. Its interaction with intestinal epithelial cells is little known. Lactic acid bacteria (LAB) were recognized as a prominent probiotic gastrointestinal microbiota of humans and animals that confer health-promoting and protective effects. This study aims to determine the anti-invasion and antibacterial effects of heat-killed LAB (HK-LAB) isolates against S. Typhimurium towards human intestinal cells. Materials and Methods: 12 HK-LAB isolates from 3 sources of origin (stingless bee, plant, and food) were tested to determine the adhesion of HK-LAB to Caco-2 cells, anti-invasion and antibacterial activities against S. Typhimurium, the adhesion and invasion pattern of S. Typhimurium on intestinal epithelial cells (Caco-2) and assessing the effect of LAB on the S . Typhimurium-host cell interaction. Results: Tairu isolates from food have the highest adhesion rate with 19 +/- 1.32/10 Caco-2 cells followed by HK-LAB R-isolate from plant 17 +/- 0.70/10 Caco-2 cells, which is similar to the control (Lactobacillus casei). In the anti-invasion assay, the two HK-LAB isolates that had the strongest adherence to Caco-2 cells, Tairu-isolate inhibited at 78.1 +/- 3.06% and R-isolate inhibited at 64.76 +/- 9.02% compared to the positive control (63.81 +/- 1.15%), which led to increased suppression of S. Typhimurium accordingly. Tairu and R isolates were tested for their antibacterial ability against S . Typhimurium. Both R and Tairu isolates displayed strong inhibition zones (27 +/- 0.06 mm, 23 +/- 0.06 mm) respectively. Conclusion: These findings suggest that the anti-invasion activities of HK-LAB R and Tairu may correlate to their bactericidal effects that serve to protect the host from infection.