Identification of isothiazolones analogues as potent bactericidal agents against antibiotic resistant CRE and MRSA strains

Table 3 MIC (µg/mL) screening of MRM and isothiazol-3(2H)-ones against clinically isolated CRE strains carrying NDM-1 and additional β-lactamases

Compound	Escherichia coli06 (EC06)	Citrobacter freundii17 (CF17)	Enterobacter cloacae27 (ECL27)	Klebsiella pneumoniae14 (KP14)	Morganella morganii23 (MM23)
MRM	≥ 128	≥ 128	64	≥ 128	64
4a	8	16	16	16	16
4b	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
4c	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
5a	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
5b	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
5c	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
5d	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
5e	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
5f	16	16	16	8	16
5 g	≤ 2	≤ 2	≤ 2	≤ 2	≤ 2
6	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128
7	16	≥ 128	32	32	8
8	≥ 128	≥ 128	≥ 128	32	≥ 128
9	≥ 128	≥ 128	≥ 128	≥ 128	≥ 128

Clinical strains usually produce NDM-1 enzyme and other additional β-lactamases whose genes carried in different strains are detailed shown respectively. EC06 consists of CTX-M-3, CTX-M-14, SHV-12. CF17 consists of SHV-12. ECL27 consists of CTX-M-3, CTX-M-14, TEM-1, SHV-12. KP14 consists of CTX-M-14, KPC-2, SHV-12. MM23 only has NDM-1. MIC values were determined using the double dilution method in accordance with the CLSI guidelines and previous reports by which inhibition of bacterial growth was assessed by naked eye after overnight incubation. The results were obtained from MIC experiments performed at least triplicate

ISSN: 2661-801X