Genetics of antimicrobial resistance
ABSTRACT Antimicrobial resistant strains of bacteria are an increasing threat to animal and human health. Resistance mechanisms to circumvent the toxic action of antimicrobials have been identified and described for all known antimicrobials currently available for clinical use in human and veterinary medicine. Acquired bacterial antibiotic resistance can result from the mutation of normal cellular genes, the acquisition of foreign resistance genes, or a combination of these two mechanisms. The most common resistance mechanisms employed by bacteria include enzymatic degradation or alteration of the antimicrobial, mutation in the antimicrobial target site, decreased cell wall permeability to antimicrobials, and active efflux of the antimicrobial across the cell membrane. The spread of mobile genetic elements such as plasmids, transposons, and integrons has greatly contributed to the rapid dissemination of antimicrobial resistance among several bacterial genera of human and veterinary importance. Antimicrobial resistance genes have been shown to accumulate on mobile elements, leading to a situation where multidrug resistance phenotypes can be transferred to a susceptible recipient via a single genetic event. The increasing prevalence of antimicrobial resistant bacterial pathogens has severe implications for the future treatment and prevention of infectious diseases in both animals and humans. The versatility with which bacteria adapt to their environment and exchange DNA between different genera highlights the need to implement effective antimicrobial stewardship and infection control programs in both human and veterinary medicine.
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ABSTRACT: The purpose of this study was to explore antimicrobial effect of four plant extracts Mentha cervina , Mentha longifolia,Ocimum basilicum and Origanum vulgare against multi-drug resistance (MDR) Staphylococcus aureus isolated from wound infections in Al madinah Almounawarah, Saudi Arabia. MRSA is resistant to not only methicillin and other β- lactam antibacterial agents but also other antibacterial agents; therefore new agents are needed to treat MRSA. Antibacterial activity of the medicinal plant extract was determined using well diffusion assays and paper disc diffusion method. The medicinal plant extract exhibited antibacterial activity against multi-drug resistance (MRSA) Staphylococcus aureus. The synergetic effect was clearly observed with Mentha longifolia were combined with Ocimmum basilicum , and followed by Mentha longifolia + Origanum vulgare, Mentha longifolia + Mentha cervina and Ocimmum basilicum + Mentha cervina then , Origanum vulgare + Ocimmum basilicum and Origanum vulgare + Mentha cervina and showed the strongest antimicrobial activity. our result confirmed that ethanolic extracts, could be a possible source to obtain new and effective herbal medicines to treat infections caused by multi-drug resistant strains of microorganisms from community as well as hospital settings. In addition ethanolic extracts of our medicinal plants may have the potential to restore the effectiveness of β-lactam Antibacterial agents against MRSA.
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ABSTRACT: Adiantum capillus veneris is a medicinally essential plant used for the treatment of diverse infectious diseases. The study of phytochemical and antimicrobial activities of the plant extracts against multidrug-resistant (MDR) bacteria and medically important fungi is of immense significance. Extracts from the leaves, stems, and roots of Adiantum capillus veneris were extracted with water, methanol, ethanol, ethyl acetate, and hexane and screened for their antimicrobial activity against ten MDR bacterial strains and five fungal strains isolated from clinical and water samples. Ash, moisture, and extractive values were determined according to standard protocols. FTIR (Fourier transform infrared Spectroscopy) studies were performed on different phytochemicals isolated from the extracts of Adiantum capillus Veneris. Phytochemical analysis showed the presence of flavonoids, alkaloids, tannins, saponins, cardiac glycosides, terpenoids, steroids, and reducing sugars. Water, methanol, and ethanol extracts of leaves, stems, and roots showed significant antibacterial and antifungal activities against most of the MDR bacterial and fungal strains. This study concluded that extracts of Adiantum capillus veneris have valuable phytochemicals and significant activities against most of the MDR bacterial strains and medically important fungal strains.The Scientific World Journal 01/2014; 2014:269793. DOI:10.1155/2014/269793 · 1.73 Impact Factor