Antibacterial efficacy of silver nanoparticles and ethyl acetate’s metabolites of the potent halophilic (marine) bacterium, Bacillus cereus A30 on multidrug resistant bacteria

Abstract

Bacteria are generally responsible for the prevalence of several diseases and pathogenic bacteria are showing increasing resistance to different antibacterials. During the present study an extremophilic bacterium-A30 isolated from the marine waters was characterized and evaluated against four multi-drug resistant (MDR) pathogens, viz; Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The sensitivity pattern of the selected pathogens was tested with 31 antibiotics. Among the 47 marine microbial extracts tested on 4-MDR pathogens viz: Methicillin-resistant Staphylococcus aureus (MRSA), E. coli, K. pneumoniae and P. aeruginosa, only our strain A30 strain exhibited highest efficacy. This strain was subsequently subjected to 16S rDNA sequencing which confirmed its allocation as Bacillus cereus. Silver nanoparticle (AgNPs) synthesis and ethyl acetate extraction were performed using the supernatant of B. cereus. The synthesized AgNPs were characterized by UV-Visible, Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), Field emission-scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and Zeta potential analyses. The presence of functional groups and 13 bioactive components in the ethyl acetate extract were analyzed using FT-IR and gas chromatography-mass spectrometry (GC-MS). The synthesized of AgNPs and the ethyl acetate extract showed preponderant activity against P. aeruginosa and MRSA, respectively. The effects of AgNPs were significant when compared to ethyl acetate extract. Therefore, the halophilic bacterium, B. cereus mediated AgNPs could provide antibacterial applications in the biomedical industries.

Eco-friendly bio-larvicidal and antimicrobial activity of isolated bioactive compound from Kurthia gibsonii (Bacillales)

“…The 48 h freshly cultured was separated from the culture broth by centrifugation (8000 rpm at 4ºC) for 15 min. The secondary metabolites extract from the CFS of K. gibsonii was using diethyl ether solvent through an extraction method (acid-based techniques), were followed by Arul et al (2017).…”

Antibiotics Development and the Potentials of Marine-Derived Compounds to Stem the Tide of Multidrug-Resistant Pathogenic Bacteria, Fungi, and Protozoa

“…Fatty acids produced by Red Sea bacterium, Bacillus toyonensis strain GAD1 (Alexandria, Egypt), exhibited antifungal activity against C. albicans ATCC 10231 (8-15 mm) [48]. Metabolites (hentriacontane, distearyl thiodipropionate and 1,2-benzenedicarboxylic acid, and mono-(2-ethylhexyl)-ester) produced by a similar halophilic bacterium, Bacillus cereus A30 (Rameswaram, India) exhibited activity on multidrug-resistant bacteria, MDR E. coli, MDR K. pneumoniae, MDR MRSA, and MDR P. aeruginosa (MIC = > 25, 25, 12.5, and < 25 µg/mL, respectively) [49].…”

Nanoparticle–Plant Interactions: Two‐Way Traffic

“…Numerous investigations have tested the effect of Ag NPs on microbial and animal cells, but little information is available on the growth and development of the plants . The germination of the seeds and the synthesis of the proteins and carbohydrates increased in Bacopa monnieci after seed treatment with Ag NPs, whereas the phenol content, catalase activity, and peroxidase activity decreased 148a.…”