Isolation of a potent antibiotic producer bacterium, especially against MRSA, from northern region of the Persian Gulf

Abstract

Nowadays, emergence and prevalence of MRSA (Methicillin Resistant Staphylococcus aureus) strain have become a great global concern in  st century, so, it is necessary to discover new antibiotics against this pathogen. Th e aim of this study was isolation and evaluation marine bacteria from the Persian Gulf in order to fi nding antibiotic compounds against some pathogenic bacteria. For this purpose, water and sediment samples were collected from the Persian Gulf during March to October . Th e antibacterial activity of the isolated bacteria was assessed using disc diff usion method. Th e Growth Curve Interference (GCI) parameter against MRSA was determined for the high potential antibiotic producing strain. Th e most important factors aff ecting fermentation conditions in antibiotic production were also optimized. Defi nite identifi cation of intended isolate was confi rmed by S rRNA sequencing. Altogether,  bacterial colony was isolated and among them only  bacterium showed antibacterial activity. Pseudoalteromonas piscicida PG- isolated from a sediment sample was chosen as the best antibiotic producing strain. Th is strain was eff ective against all tested Gram-positive bacteria, had good anti-MRSA activity and also GCI value against MRSA was two times lower than MIC value. Among the optimized fermentation parameters, carbon and nitrogen sources play major role in effi cacy of optimized antibiotic production. Ultrastructural study on the eff ect of intended antibiotic compounds on MRSA using TEM revealed that the target site for this compound is cell wall. Considering the antibacterial eff ect of PG- strain especially against MRSA, intended antibiotic compounds can gives hope for treatment of diseases caused by multi-drug resistant bacteria.

Characterization and activity of antimicrobial polypeptide of Bacillus spp from wastelands of Kathmandu valley

“…The highest number of antibiotic producing isolate was B. subtilis (40.09%) and the least number of antibiotic producing isolate belonged to the species B. circulans (4.54%). This result is contrasting to a study carried out in soil of marine environment where antibiotic producers of genus Bacillus were all identified as B. subtilis (21). The highest number of antibiotic producers were found in basic soil (45.45%) whereas the least were found in acidic soil (13.6%).…”

“…In a study similar like this where the activity of the antibiotic producers was only tested against Gram positive bacteria, 5.88% showed antibacterial activity against Gram-positive bacteria, and also had good activity against MRSA (21). (Darabpour et al 2012 9.09% colonies had a broad spectrum activity.…”

“…In a study similar like this where the activity of the antibiotic producers was only tested against Gram positive bacteria, 5.88% showed antibacterial activity against Gram-positive bacteria, and also had good activity against MRSA (21). (Darabpour et al 2012 9.09% colonies had a broad spectrum activity. Abdulkadir and Waliyu (23) and Darabapour et al (21) also found Bacillus alvei inhibited the growth of both Gram positive and Gram negative bacteria and they were indicated as broad spectrum antibiotic producer.…”

Time-kill profiles and cell-surface morphological effects of crude Polycephalomyces nipponicus Cod-MK1201 mycelial extract against antibiotic-sensitive and -resistant <i>Staphylococcus aureus</i>

“…Similar cell wall effects have been reported in S. aureus treated with bacteria-derived antibiotics [24,25].…”

Anti-methicillin Resistant Staphylococcus aureus Compound Isolation from Halophilic Bacillus amyloliquefaciens MHB1 and Determination of Its Mode of Action Using Electron Microscope and Flow Cytometry Analysis

“…Previous studies reported the isolation of anti-MRSA substances, especially from marine Pseudomonas species. Darabpour et al [26] collected the sediment samples from Persian Gulf and isolated the Pseudoalteromonas piscicida PG-01 showing potent anti-MRSA activity. Similarly, Pseudoalteromonas phenolica O-BC30 [7] and Pseudomonas sp.…”