Multidrug-resistant bacteria are a growing issue worldwide. This study developed a convenient and effective method to downregulate the expression of a specific gene to produce a novel antimicrobial tool using a small (140 nucleotide) RNA with a 24-nucleotide antisense (as) region from an arabinoseinducible expression phagemid vector in Escherichia coli. Knockdown effects of rpoS encoding RNA polymerase sigma factor were observed using this inducible artificial as RNA approach. as RNAs targeting several essential E. coli genes produced significant growth defects, especially when targeted to acpP and ribosomal protein coding genes rplN, rplL, and rpsM. Growth inhibited phenotypes were facilitated in hfq(-)conditions. Phage lysates were prepared from cells harboring phagemids as a lethal-agent delivery tool. Targeting the rpsM gene by phagemid-derived M13 phage infection of E. coli containing a carbapenem-producing F-plasmid and multidrug-resistant Klebsiella pneumoniae containing an F-plasmid resulted in the death of over 99.99% of infected bacteria. This study provides a possible strategy for treating bacterial infection and can be applied to any F-pilus producing bacterial species. (C) 2020 The Author(s). Published by Elsevier Inc.