Inhibiting plasmid mobility: The effect of isothiocyanates on bacterial conjugation

Awo Afi Kwapong, Paul Stapleton, Simon Gibbons

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17 Citations (Scopus)


Bacterial conjugation is the main mechanism for the transfer of multiple antimicrobial resistance genes among pathogenic micro-organisms. This process may be controlled by compounds that inhibit bacterial conjugation. In this study, the effects of allyl isothiocyanate, L-sulforaphane, benzyl isothiocyanate, phenylethyl isothiocyanate and 4-methoxyphenyl isothiocyanate on the conjugation of broad-host-range plasmids harbouring various antimicrobial resistance genes in Escherichia coli were investigated, namely plasmids pKM101 (IncN), TP114 (IncI 2 ), pUB307 (IncP) and the low-copy-number plasmid R7K (IncW). Benzyl isothiocyanate (32 mg/L) significantly reduced conjugal transfer of pKM101, TP114 and pUB307 to 0.3 ± 0.6%, 10.7 ± 3.3% and 6.5 ± 1.0%, respectively. L-sulforaphane (16 mg/L; transfer frequency 21.5 ± 5.1%) and 4-methoxyphenyl isothiocyanate (100 mg/L; transfer frequency 5.2 ± 2.8%) were the only compounds showing anti-conjugal specificity by actively reducing the transfer of R7K and pUB307, respectively.

Original languageEnglish
Pages (from-to)629-636
Number of pages8
JournalInternational Journal of Antimicrobial Agents
Issue number5
Early online date24 Jan 2019
Publication statusPublished - May 2019


  • Bacterial conjugation
  • Conjugative plasmid
  • Effector protein
  • Horizontal gene transfer
  • Isothiocyanate
  • Plasmid incompatibility group

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