Dual Antimicrobial Effect of Medium-Chain Fatty Acids against an Italian Multidrug Resistant Brachyspira hyodysenteriae Strain

Abstract

The fastidious nature of Brachyspira hyodysenteriae limits an accurate in vitro pre-screening of conventionally used antibiotics and other candidate alternative antimicrobials. This results in a non-judicious use of antibiotics, leading to an exponential increase of the antibiotic resistance issue and a slowdown in the research for new molecules that might stop this serious phenomenon. In this study we tested four antibiotics (tylosin, lincomycin, doxycycline, and tiamulin) and medium-chain fatty acids (MCFA; hexanoic, octanoic, decanoic, and dodecanoic acid) against an Italian field strain of B. hyodysenteriae and the ATCC 27164 strain as reference. We determined the minimal inhibitory concentrations of these substances, underlining the multidrug resistance pattern of the field strain and, on the contrary, a consistent and stable inhibitory effect of the tested MCFA against both strains. Then, sub-inhibitory concentrations of antibiotics and MCFA were examined in modulating a panel of B. hyodysenteriae virulence genes (tlyA, tlyB, bhlp16, bhlp29.7, and bhmp39f). Results of gene expression analysis were variable, with up- and downregulations not properly correlated with particular substances or target genes. Decanoic and dodecanoic acid with their direct and indirect antimicrobial property were the most effective among MCFA, suggesting them as good candidates for subsequent in vivo trials.

Study on molecular mechanism of volatiles variation during Bupleurum scorzonerifolium root development based on metabolome and transcriptome analysis

“…In previous researches, 1-dodecanol, dodecanal and decanal were confirmed to have antibacterial, antiviral, tyrosinase inhibition, anxiolytic and sedative activities (Snipes et al, 1977;Davis-Hanna et al, 2007;Togashi et al, 2007;Hajhashemi et al, 2010;Hall et al, 2011;Mukherjee et al, 2013;Murray et al, 2019;Giovagnoni et al, 2022). These compounds were the dominant volatiles of BSVO and accumulated mainly at the fruiting stage.…”

Evaluation of antibacterial, antioxidant, and anti-inflammatory properties of GC/MS characterized methanol leaf extract of Terminalia superba (Combretaceae, Engl. & Diels)

“…This will lead to compromise in membrane integrity resulting in cell permeability, inhibition of growth, lysis, and ultimately death [61]. Decanoic acid (capric acid) is known for its excellent activity against resistant Brachyspira hyodysenteriae, Salmonella spp, E. coli, and Campylobacter jejuni [24,69]. Mohamed [48] showed that 1,2-Benzenedicarboxylic acid, butyl 2-ethylhexyl ester isolated from hemolymph of scarab beetle Scarabaeus sacer (Coleoptera Scarabaeidae) had good antibacterial activity against Enterobacter cloacae, Escherichia coli (both gram negative), Bacillus subtilis, and Staphylococcus aureus (gram positives) which is in agreement with this study.…”

Thymol as an Adjuvant to Restore Antibiotic Efficacy and Reduce Antimicrobial Resistance and Virulence Gene Expression in Enterotoxigenic Escherichia coli Strains

“…Bacterial RNA extraction and retrotranscription were performed as previously described [ 20 , 68 ]. Briefly, after incubation, tubes were centrifuged for 5 min at 5000× g , the supernatant was discarded, and the pellet was incubated for 10 min at 37 °C in a Tris-EDTA buffer with 1 mg/mL lysozyme.…”