Molecular Characterization of Methicillin Resistant and Extended Spectrum β-Lactamase Staphylococcus aureus Isolated from Burn Patients

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Shawnm Ahmed Aziz


Antibiotic resistance has become a major world health challenge and has limited the ability of physician's treatment. Staphylococcus aureus the most notorious pathogens causes morbidity and mortality especially in burn patients. However, Staphylococcus aureus rapidly acquired resistance to multiple antibiotics. Vancomycin, a glycopeptide antibiotic remains a drug of choice for treatment of severe Methicillin Resistance S. aureus infections. This study aimed to detect the emergence of beta-lactam and glycopeptide resistance genes. 50 clinical specimens of S. aureus collected from burn patients in burn and plastic surgery units in Sulaimani-Iraq city. All specimens were confirmed to be positive for S. aureus. All the isolates were assessed for their susceptibility to different antibiotics depending on NCCL standards, followed by Extended Spectrum Beta Lactamase detection by double disk diffusion synergy test. The production of β- lactamases was evaluated in the isolated strains by several routine methods and polymerase chain reaction. Among the isolates 94% were Methicillin resistance and 34.28% were Extended Spectrum Beta Lactamase producer. PCR based molecular technique was done for the bla genes related to β- lactamase enzymes by the specific primers, as well as genes which related to reduced sensitivity to Vancomycin were detected. The results indicated that all isolated showed the PBP1, PBP2, PBP3, PBP4, trfA and trfB, graSR, vraS except the vraR gene and the prolonged therapy of Methicillin resistance infection with teicoplanin have been associated with progress of resistance and the rise of tecoplanin resistance may be a prologue to evolving Vancomycin resistance. In conclusion, beta-lactam over taking can rise Vancomycin- Intermediate S. aureus strains leading to appearance of Vancomycin resistance although the treatment of Vancomycin resistant infections is challenging.


Methicillin Resistance Staphylococcus aureus, Extended Spectrum Beta Lactamase, Vancomycin, Penicillin Binding Proteins.


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[1] R. Aftab, and I. Iqbal, “Bacteriological agent of neonatal sepsis in NICU at Nishter hospital Multan,” Journal of Coll Physicians Surg Pak. 16(3) pp.216–219,2006.
[2] A. Severin, K. Tabei, F. Tenover, M. Chung, N. Clarke, and A. Tomasz, “High level oxacillin and vancomycin resistance and altered cell wall composition in Staphylococcus aureus carrying the Staphylococcal mecA and the Enterococcal vanA gene complex,” Journal of Biol. Chem. 279, pp. 3398–3407, 2004.
[3] A. Severin, S. W. Wu, K. Tabei, and A. Tomasz, “High-level β-lactam resistance and cell wall synthesis catalyzed by the mecA homologue of Staphylococcus sciuri introduced into Staphylococcus aureus,” Journal of Bacteriol. 187, pp. 6651–6658, 2005.
[4] M. G. Pinho, H. de Lencastre, and A. Tomasz, “Cloning, characterization, and inactivation of the gene pbpC, encoding penicillin-binding protein 3 of Staphylococcus aureus,” Journal of Bacteriol. 182, pp.1074–1079, 2000.
[5] M. G. Pinho, H. de Lencastre, and A. Tomasz, “An acquired and a native penicillin-binding protein cooperate in building the cell wall of drugresistant staphylococci,” Proc. Natl. Acad. Sci. USA 98, pp. 10886–1089, 2001.
[6] M. Kuroda, H. Kuroda, T. Oshima, F. Takeuchi, H. Mori, and K. Hiramatsu, “Two-component system VraSR positively modulates the regulation of cell-wall biosynthesis pathway in Staphylococcus aureus,” Mol. Microbiology,49, pp.807–821, 2003.
[7] S.R. Gill, D.E. Fouts, G.L. Archer, E.F. Mongodin, R.T. DeBoy, J. Ravel, et al, “Insights on evolution of virulence and resistance from the complete genome analysis of an early methicillin-resistant Staphylococcus aureus strain and a biofilm-producing methicillin-resistant Staphylococcus epidermidis strain,” Journal of Bacteriol.;187(7), pp. 2426-38, 2005.
[8] C.O. Esan, O. Famurewa, J. Lin, A.O, “Shittu. Characterizationof Staphylococcus aureus isolates obtained from health careinstitutions in Ekiti and Ondo States, South-Western Nigeria.Afr,” Journal of Microbiol Res;3, pp.962—8, 2009.
[9] M.C. Timbury, A. McCartney, and B.Thakker , “ Notes on medical microbiology.Churchill living stone,” Elsever Limited, New work,USA,pp.31-34. 2002.
[10] B.P Howden, DJ Smith, A. Mansell, PD. Johnson, PB. Ward, TP. Stinear, et al, “Different bacterial gene expression patterns and attenuated host immune responses are associated with the evolution of low-level vancomycin resistance during persistent methicillin-resistant Staphylococcus aureus bacteraemia,” BMC Microbiol.;8(1):1, 2008.
[11] M. Falord, U. Ma¨der, A. Hiron, M. De´barbouille´, T. Msadek , “Investigation of the Staphylococcus aureus GraSR Regulon Reveals Novel Links to Virulence, Stress Response and Cell Wall Signal Transduction Pathways,” PLoS ONE 6(7): e21323. doi:10.1371, journal. pone.0021323,2011.
[12] F. McAleese, Wu SW, K. Sieradzki, P. Dunman, E. Murphy, S. Projan,” Overexpression of genes of the cell wall stimulon in clinical isolates of Staphylococcus aureus exhibiting Vancomycin-Intermediate-S. aureus-type resistance to vancomycin,” Journal of Bacteriol. 188(3), pp.1120-33, 2006.
[13] A. Renzoni, WL. Kelley, C. Barras, A. Monod, E. Huggler, P. François, et al.,” Identification by genomic and genetic analysis of two new genes playing a key role in intermediate glycopeptide resistance in Staphylococcus aureus. Antimicrob Agents Chemother,” 53(3) pp.903-11, 2009.
[14] S. F. F. Pereira, A. O. Henriques, M. G. Pinho, H. de Lencastre, and A. Tomasz,”Role of PBP1 in Cell Division of Staphylococcus aureus,”, 2007.
[15] J. Finan, GL. Archer, MJ Pucci, MW. Climo,” Role of penicillin-binding protein 4 in expression of vancomycin resistance among clinical isolates of oxacillin-resistant Staphylococcus aureus,” Antimicrob Agents Chemother. 45(11), pp.3070-5, 2001.
[16] CLSI, Performance Standards for Antimicrobial Susceptibility Testing, CLSI Suppl M100, Clinical and Laboratory Standards Institute, Wayne, PA, USA, 27th edition, 2017.
[17] D. F. Brown, D.I. Edwards, and p. M. Hawkey, “Guidelines for the laboratory diagnoses and susceptibility testing of methicillin resistance Staphylococcus aureus (MRSA),” Journal of antimicrobial chemotherapy 56:1000-1018, 2005.
[18] A. F. Betty, F. S. Dannie, and S. W. Aliece, “Diagnostic microbiology,” 10th Ed, Mossy, P611, 1998.
[19] S. A. Hama, “Immunological and bacteriological study on chemical bombardment survivors in Halabja,” Msc thesis. Univ. of Sulaimani. College of Science, Bio Dept., 2002.
[20] S. Claudia, C. Paulo, and A. Hector, “Evolution and Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Epidemic and Sporadic Clones in Cordoba, Argentina,” Journal of CLINICAL MICROBIOLOGY, Vol. 44, No. 1, pp. 192–200 2006.
[21] W. D. Beck, B. Berger-Bachi, and F. H. Kayser, “Additional DNA in methicillin-resistant Staphylococcus aureus and molecular cloning of mec specific DNA,” Journal of Bacteriol. 165:373–378, 1986.
[22] Y. Katayama, T. Ito, and K. Hiramatsu, “A new class of genetic element, Staphylococcus cassette chromosome mec, encodes methicillin resistance in Staphylococcus aureus,” Antimicrob. Agents Chemother. 44: pp. 1549– 1555, 2000.
[23] G.L. Archer, D.M Niemeyer, and J.A. Thanassi, “Dissemination among staphylococci of DNA sequences associated with methicillin resistance,” Antimicrob Agents Chemother. 38: pp.447–454, 1994.
[24] B. G. Layer, W. Ko¨nig, and T. Takagi, “Heterogeneity of Methicillin-Susceptible Staphylococcus aureus Strains at a German niversity Hospital Implicates the Circulating-Strain Pool as a Potential Source of Emerging Methicillin-Resistant S. aureus Clones,” Journal of Clin. Microbiol., pp. 2179–2185, 2006.
[25] M. D. Martin, P. M. Orwin, and P. M. Schlievert, “Exotoxins of Staphylococcus aureus,” Clinical Microbiology Reviews, Vol. 13, No. 1, pp. 16-34, 2000.
[26] A. W. Wyke; J. B. Ward; M. V. Hayes; and N. A. Curtis., “A role in vivo for penicillin-binding protein-4 of Staphylococcus aureus,” Eur. Journal of Biochem. 119: pp.389–393, 1981.
[27] B. J. Hartman, and A Tomasz, “Low-affinity penicillin-binding protein associated with β-lactam resistance in Staphylococcus aureus,” Journal of Bacteriol; 158: pp. 513–516, 1984.
[28] U. U. Henze; and B. Berger-Bachi., “Staphylococcus aureus penicillinbinding protein 4 and intrinsic _-lactam resistance,” Antimicrob. Agents Chemother.39, pp. 2415–2422, 1995.
[29] K. Sieradzki, and A. Tomasz, “Gradual alterations in cell wall structure and metabolism in vancomycin-resistant mutants of Staphylococcus aureus,” Journal of Bacteriol, 181: pp.7566–7570, 1999.
[30] Vikas Nirvana, Savitha Nadig, Varun Sood,1 K. Prasad, Gayathri Arakere, and B. Gopal., “Molecular Basis for the Role of Staphylococcus aureus Penicillin Binding Protein 4 in Antimicrobial Resistance,” Journal of BACTERIOLOGY, Vol. 192, No. 1, pp. 134–144, 2010.
[31] Vikas Navratna , Savitha Nadig, Varun Sood,1 K. Prasad, Gayathri Arakere , and B. Gopal , “ Molecular Basis for the Role of Staphylococcus aureus Penicillin Binding Protein 4 in Antimicrobial Resistance,” Journal of BACTERIOLOGY, Vol. 192, No. 1,pp. 134–144. 2010.
[32] M. Kuroda, H. Kuroda, T. Oshima, F. Takeuchi, H. Mori, and K. Hiramatsu, “Two-component system VraSR positively modulates the regulation of cell-wall biosynthesis pathway in Staphylococcus aureus,” Mol. Microbiol.49: pp.807–821, 2003.
[33] S. Gardete, S. W. Wu, S. Gill; and A. Tomasz, “Role of VraSR inantibiotic resistance and antibiotic-induced stress response in Staphylococcus aureus,” Antimicrob. Agents Chemother. 50:3424–3434, 2006.

[34] I. A. Hassan, P. R. Chadwick, and A. P. Johnson, “Clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to tecoplanin in North west England,” Journal of antimicrobial chemotherapy 48, 454-5, 2001.
[ 35] Mélanie Roch, Perrine Clair,f Adriana Renzoni,g Marie-Elisabeth Reverdy,f Olivier Dauwalder,, Michèle Bes ,Annie Martra,f Anne-Marie Freydière,f Frédéric Laurent, Philippe Reix, Oana Dumitrescu, François Vandenesch, “ Exposure of Staphylococcus aureus to Subinhibitory Concentrations of _-Lactam Antibiotics Induces Heterogeneous Vancomycin- Intermediate Staphylococcus aureus ,” Journal of Antimicrobial Agents and Chemotherapy 58(9):pp. 5306–5314, 2014.
[36] K. Hiramatsu, “Vancomycin resistance in Staphylococci,” Drug Resistance Updates 1,135-50. 1998.