Basic and applied research on multiple aminoglycoside antibiotic resistance of actinomycetes: an old-timer's recollection

Abstract

A list of our research achievements on multiple aminoglycoside antibiotic (AG) resistance in AG-producing actinomycetes is outlined. In 1979, the author discovered a novel AG (istamycin)-producing Streptomyces tenjimariensis SS-939 by screening actinomycetes with kanamycin (KM)-resistance and plasmid profiles. This discovery directed our biochemical and genetic approaches to multiple AG resistance (AGR) of AG producers. In this article, the following discoveries will be outlined: 1. AGR profiles correlating with the productivity of AGs in AG-producers, 2. Wide distribution of multiple AG resistance in AG-nonproducing actinomycetes, 3. Involvement of ribosomal resistance and AG-acetylating enzymes as underlying AGR factors, 4. Activation by single nucleotide substitution of a silent gene coding for aminoglycoside 3-N-acetyltransferase, AAC(3), in S. griseus, 5. Discovery of a novel antibiotic indolizomycin through protoplast fusion treatment between S. tenjimariensis and S. griseus strains with different AGR phenotypes and 6. Double stage-acting activity of arbekacin (ABK; an anti-MRSA semisynthetic AG) discovered by acetylation of ABK with cloned AACs; i.e. both ABK and its acetylated derivatives showed remarkable antibiotic activities.

Screening, Identification, and Fermentation of a Biocontrol Strain against Peony Southern Blight and Extraction of Secondary Metabolites

“…Actinomycetes are a diverse group of microorganisms that are rich in valuable chemical compounds. For example, the antibiotics they produce are critical for the protection of plants, animals, and humans from harmful microorganisms [41][42][43][44]. Streptomyces species are the main microbes used for the biocontrol of plant diseases because of their wide host range.…”

Potentiality of Actinomycetia Prevalent in Selected Forest Ecosystems in Assam, India to Combat Multi-Drug-Resistant Microbial Pathogens

“…Similarly, Streptomyces sp. PBR36 contains smBGCs that encode for ulleungmycin [ 99 ], griseoviridin [ 100 ], tylactone [ 101 ], and istamycin [ 102 ], all of which have antimicrobial activity against MDR bacterial pathogens. PBR36 also encodes the biosynthesis of abyssomicin C and actinomycin D gene clusters.…”

Biological control and plant growth promotion properties of Streptomyces albidoflavus St-220 isolated from Salvia miltiorrhiza rhizosphere

“…The strains of Streptomyces genus employ their secondary metabolites as weapons to inhibit phytopathogenic fungi ( Amin et al, 2021 ; Hotta, 2021 ; Mahasneh et al, 2021 ; Terra et al, 2021 ). In this study, genome sequencing revealed that the chromosome of the St. albidoflavus St-220 contained 21 conserved biosynthesis gene clusters (BGCs), of which 10 showed high similarities in structure with known BGCs encoding terpenes, non-ribosomal peptides, polyketides, siderophores, and ectoines, which had been proven to participate in the regulation of antimicrobial activities of Streptomyces strains ( van Bergeijk et al, 2020 ).…”