Methicillin-susceptible Staphylococcus aureus

Goodacre, R. Rooney, P. I Kell, D. B. Discrimination between methicillin-resistant and methicillin-susceptible Staphylococcus aureus using pyrolysis mass spectrometry and artificial neural networks. J. Antimicrob. Chemother. 1998, 41, 27-34. 

Levofloxacin (1), the levo-isomer or the (5)-enantiomer of ofloxacin, received FDA approval in 1996 (Fish, 2003 Hurst et al., 2002 Mascaretti, 2003 Norrby, 1999 North et al., 1998). The initial approval covered community-acquired pneumonia, acute bacterial exacerbation of chronic bronchitis, acute maxillary sinusitis, uncomplicated skin and skin structure infections, acute pyelonephritis, and complicated urinary tract infections (North et al., 1998). Four years later, the levofloxacin indication list grew to include community-acquired pneumonia caused by penicillin-resistant Streptococcus pneumoniae. In addition, in 2002, nosocomial (hospital-acquired) pneumonia caused by methicillin-susceptible Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Haemophilus influenzae, Kliebsella pneumoniae, and Escherichia coli was added (Hurst et al., 2002). Finally in 2004, LVX was approved as a post-exposure treatment for individuals exposed to Bacillus anthracis, the microbe that causes anthrax, via inhalation (FDA, 2004). 

Mason, B.W., Howard, A.J., and Magee, J.T., Fusidic acid resistance in community isolates of methicilline-susceptible Staphylococcus aureus and fusidic acid prescribing. J. Antimicrob. Chemother. 51, 1033-1036, 2003. 

Shore AC, Rossney AS, O Connell B, Herra CM, Sullivan DJ, Humphreys H, Coleman DC (2008) Detection of staphylococcal cassette chromosome mec-associated DNA segments in multire-sistant methicillin-susceptible Staphylococcus aureus (MSSA) and identification of Staphylococcus epidermidis ccrAB4 in both methicilhn-resistant S. aureus and MSSA. Antimicrob Agents Chemother 52 4407-4419... 

The ferrocenyl bioconjugates of 6-aminopenicillanic acid 112 (Figure 3.7) have been evaluated for their antibacterial activity against S. aureus ATCC 29213 (MSSA, methicillin-susceptible Staphylococcus aureus), S. aureus ATCC 43300 (MRSA, methicillin-resistant Staphylococcus awrews), S. awrewsATCC 700787 (VRSA, vancomycin-resistant Staphylococcus aureus), and Staphylococcus epidermidis ATCC 12228 bacterial strains [86]. The minimum inhibitory concentration (MIC) of... 

The antibacterial effects of tea polyphenols extracted from Korean green tea (Camellia sinensis (L.) O. Kuntze (Theaceae)) against clinical isolates of methicil-lin-resistant Staphylococcus aureus (MRSA) were evaluated (Cho et al. 2008). Characterisation of the MIC of oxacillin for 30 Staphylococcus aureus strains isolated from patients treated with oxacillin identified 13 strains with an oxacillin MIC>4 pg/ml as MRSA (range 8-512 pg/ml), while 17 strains were methicillin-susceptible Staphylococcus aureus (MSSA range 0.25-0.5 pg/ml). The MICs of tea polyphenols ranged from 50 to 180 pg/ml for both the MSSA and the MRSA strains. The MICs of oxacillin for each of the 13 MRSA strains were reduced between 8- and 128-fold when these strains were coincubated with sub-MIC (<0.5 X MIC) levels of tea polyphenols, demonstrating that this combination was synergistic for all of the clinical MRSA isolates (Cho et al. 2008). 

Another important advance has been the application of PyMS with ANNs to discriminate between methicillin-resistant and methicillin-sensitive Staphylococcus aureusIn this study DFA and HCA showed that the major source of variation between the pyrolysis mass spectra of 15 methicillin-resistant (MRSA) and 22 methicillin-sensitive Staphylococcus aureus (MSSA) strains resulted from the phage group of the bacteria, rather than from their resistance or sensitivity to methicillin. By contrast, ANNs could recognize those aspects of the pyrolysis mass spectra that differentiated MRSA and MSSA strains. These results gave the first demonstration that the combination of PyMS with ANNs could provide a rapid and accurate antibiotic-susceptibility testing technique. 

S. A. Roberts, J. Robson, K. Read, N. Bak, J. Hurley, P.D.R. Johnson, A.J. Morris, B.C. Mayall, and M.L. Grayson (2004). Treatment outcomes for serious infections caused by methicillin-resistant Staphylococcus aureus with reduced vancomycin susceptibility. Clinical Infectious Diseases 38 521-528. 

Howe R.A., A. Monk, M. Wootton, T.R. Walsh, and M.C. Enright (2004). Vancomycin susceptibility within methicillin-resistant Staphylococcus aureus lineages. Emerging Infectious Diseases 10 855-857. 

Hiramatsu et al Methicillin resistant Staphylococcus aureus clinical strain with reduced vancomycin susceptibility. J Antimicrob Chemother 1997 40 135. [PMID 9249217]... 

Cephalosporins have been classified as first, second or third generation, largely on the basis of bacterial susceptibility patterns and resistance to p-lactamases (Figure 30.8). [Note They are ineffective against methicillin-resistant Staphylococcus aureus (MRSA), Listeria monocytogenes. Clostridium diffidle and the enterococci.]... 

Andersen BM, Bergh K, Steinbakk M, Syversen G, Magnaes B, Dalen H, Bruun JN. A Norwegian nosocomial outbreak of methicillin-resistant Staphylococcus aureus resistant to fusidic acid and susceptible to other antistaphylococcal agents. J Hosp Infect 1999 41(2) 123-32. 

Trakulsomboon S, Danchaivijitr S, Rongrungruang Y, Dhiraputra C, Susaemgrat W, Ito T, Hiramatsu K. First report of methicillin-resistant Staphylococcus aureus with reduced susceptibility to vancomycin in Thailand. J Clin Microbiol 2001 39(2) 591-5. 

While many natural products have been tested against hundreds of different strains of bacteria, the most common bacteria used in susceptibility tests include Bacillus cereus, Bacillus subtillis, Chlamydia pneumonia, Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Klebsiella pneumoniae, vancomycin-resistant Enterococcus (VRE), Pseudomonas aeruginosa and Helicobacter pylori [18, 19], As the amount of published data describing the in vitro, in vivo and clinical antibacterial activities of natural products is so vast it could easily fill a book (or two), this review focuses only on natural products for which there is in vitro, in vivo and some clinical antibacterial data, as well as a plausible mechanism of action. 

Aires de Sousa, M., Conceicao, T., Simas, C., and de Lencastre, H. (2005). Comparison of genetic backgrounds of methicillin-resistant and -susceptible Staphylococcus aureus isolates from Portuguese hospitals and the community. J. Clin. Microbiol. 43, 5150-5157. 

Carson, C.R, Cookson, B.D., Farrelly, H.D, Riley, T.V. 1995. Susceptibility of methicillin-resistant Staphylococcus aureus to the essential oil of Melaleuca alternifolia. 

Cantore, P.L., N.S. lacobellis, A. DeMarco et al., 2004. Antibacterial activity of Coriandrum sativum L. and Foeniculum vulgare Miller var. vulgare (Miller) essential oils. J. Agric. Food Chem., 52 7862-7866. Carson, C.F., B.D. Cookson, H.D. Farrelly et al., 1995. Susceptibility of methicillin resistant Staphylococcus aureus to the essential oil of Melaleuca altemifolia. J. Antimicrob. Chemother., 35 421 424. 

Majcherczyk PA, McKenna T, Moreillon P, Vaudaux P. The discriminatory power of MALDI-TOF mass spectrometry to differentiate between isogenic teicoplanin-susceptible and teico-planin-resistant strains of methicillin-resistant Staphylococcus aureus. FEMS Microbiol Lett. 2006 255 233-9. 

Enany S, Yoshida Y, Yamamoto T. Exploring extra-cellular proteins in metliicillin susceptible and methicillin resistant Staphylococcus aureus by liquid chromatography tandem mass spectrometry. World J Microbiol Biotechnol. 2014 30 1269 83. doi 10.1007/sll274-013-1550-7. 

Callaway TR, Carr MA, Edrington TS, Anderson RC, Nisbet DJ (2009) Diet, Escherichia coli 0157 H7, and cattle a review after 10 years. Curr Issues Mol Biol 11 67-80 Calsamiglia S, Busquet M, Cardozo PW et al (2007) Invited review essential oils as modifiers of rumen microbial fermentation. J Dairy Sci 90 2580-2595 Carson CF, Cookson BD, Farrelly HD, Riley TV (1995) Susceptibility of methicillin-resistant Staphylococcus aureus to the essential oil of Melaleuca alternifolia. J Antimicrob Chemother 35 421 24... 

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