Evaluation of molecular typing methods for some scab-causing Streptomyces strains from Turkey.

This study was conducted for identifying phylogenetic relationships between 15 scab-causing Streptomyces species including S. bottropensis, S. europaeiscabiei, S. scabiei, S. stelliscabiei and, other 11 Streptomyces sp. All of the strains were originally isolated from symptomatic potatoes in Erzurum Province, The Eastern Anatolia Region of Turkey. Some morphological and biochemical properties of the strains were defined in our former research. Then, 16 s rRNA regions of them were sequenced. After the sequence data assembly, phylogenetic analyzes were performed. The phylogenetic analyses revealed that the strains are involved in the same major group and, substantially similar to reference strains. Additionally, some subgroup formations were also recorded. Moreover, Repetitive element-based PCR (Rep-PCR), Enterobacterial repetitive intergenic consensus (ERIC-PCR), and BOX-PCR fingerprinting molecular typing methods were used for as molecular typing methods. According to our knowledge, this is the first report on phylogenetic relationships of scab-causing Streptomyces species from Turkey. However, the identification of most pathogenic strains remained at the species level.

Enhancing bactericidal strategy with selected aromatic compounds: in vitro and in silico study.

ß-Lactamases are enzymes that catalyze the hydrolysis of the ß-lactam ring, resulting in loss of function in ß-lactam antibiotics. In this report, the inhibition of ß-lactamase enzyme by group-based selected aromatic compounds, especially containing flavone ring, was investigated in vitro and in silico. For this purpose, the inhibitory effects of 7-hydroxy-4'-nitroisoflavone, myricetin, formononetin, 3-methylflavone-8-carboxylic acid, 6-fluoroflavone and caffeic acid on ß-lactamase from Bacillus cereus enzyme activity were investigated. IC50 values of these compounds were determined to range from 53 to 346 mM. 7-hydroxy-4'-nitroisoflavone, formononetin and myricetin inhibited the enzyme with the Ki values of 27.65 ± 4.22, 58.92 ± 12.83 and 67.42 ± 5.77 µM, respectively. To evaluate the potential enzyme binding positions of the active compounds, docking studies were performed. In addition to kinetic and in silico studies, the synergistic effects of the compounds with penicillin on Klebsiella pneumoniae (ATCC 700603) and Escherichia coli (ATCC 35128) were tested in vitro. Our results indicated that 7-hydroxy-4'-nitroisoflavone, 3-methylflavone-8-carboxylic acid and myricetin that combined with penicillin completely precluded the bacterial growth.Communicated by Ramaswamy H. Sarma.