Antimicrobial activity of apitoxin from Apis mellifera in Salmonella enterica strains isolated from poultry and its effects on motility, biofilm formation and gene expression

• Published in: Microbial pathogenesis Vol. 137; p. 103771
• Main Authors: Arteaga, Vicente, Lamas, Alexandre, Regal, Patricia, Vázquez, Beatriz, Miranda, José Manuel, Cepeda, Alberto, Franco, Carlos Manuel
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2019
• Subjects: Animals; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Antimicrobial activity; Apitoxin; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bee; Bee Venoms - isolation & purification; Bee Venoms - pharmacology; Bees - chemistry; Biofilm; Biofilms - drug effects; Gene expression; Gene Expression Regulation, Bacterial - drug effects; Microbial Sensitivity Tests; Motility; Poultry; Poultry Diseases - microbiology; Salmonella; Salmonella enterica - drug effects; Salmonella enterica - genetics; Salmonella enterica - isolation & purification; Salmonella enterica - physiology; Salmonella Infections, Animal - microbiology; Salmonella; Antimicrobial activity; Apitoxin; Motility; Bee; Biofilm; Gene expression
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/j.micpath.2019.103771

Salmonella is a major global food-borne pathogen. One of the main concerns related to Salmonella and other food-borne pathogens is their capacity to acquire antimicrobial resistance and produce biofilms. Due to the increased resistance to common antimicrobials used to treat livestock animals and human infections, the discovery of new antimicrobial substances is one of the main challenges in microbiological research. An additional challenge is the development of new methods and substances to inhibit and destruct biofilms. We determined the antimicrobial and antibiofilm activities of apitoxin in 16 Salmonella strains isolated from poultry. In addition, the effect of apitoxin on Salmonella motility and the expression of biofilm- and virulence-related genes was evaluated. The minimum inhibitory concentrations (MIC) of apitoxin ranged from 1,024–256 μg/mL, with 512 μg/mL being the most common. Sub-inhibitory concentrations of apitoxin significantly reduced biofilm formation in 14 of the 16 Salmonella strains tested, with significant increases in motility. MIC concentrations of apitoxin destroyed the pre-formed biofilm by 27.66–68.22% (47.00% ± 10.91). The expression of biofilm- and virulence-related genes and small RNAs was differentially regulated according to the strain and the presence of apitoxin. The transcription of the small RNAs dsrA and csrB, related to antimicrobial resistance, was upregulated in the presence of apitoxin. We suggest that apitoxin is a potential antimicrobial substance that could be used in combination with other substances to develop new drugs and sanitizers against food-borne pathogens. •Apitoxin has antimicrobial activity against Salmonella enterica strains.•Sub-inhibitory concentrations of apitoxin increased Salmonella motility.•Minimum inhibitory concentration of apitoxin destroyed pre-formed biofilms.•Salmonella gene expression was influenced by subinhibitory concentrations of apitoxin.•Apitoxin is a promising alternative to common antimicrobials and biocides.