IN VITRO PHAGOCYTOSIS OF METHICILLIN RESISTANT AND METHICILLIN SENSITIVE STAPHYLOCOCCUS AUREUS BY HUMAN POLYMORPHONUCLEAR LEUCOCYTES
AbstractBackground: Staphylococcus aureus is a gram positive bacterium that causes a number of diseasessuch as abscesses, infective endocarditis, septic arthritis, etc. It is acquiring resistance against manyantibiotics like methicillin; therefore its control is becoming increasingly difficult. Peripheral bloodphagocytes particularly polymorphonuclear leucocytes play an important role in the protectivemechanisms against these organisms. Phagocytes interact with bacteria and phagocytose thesemicroorganisms to kill them. Methods: Phenotypically different isolates of Staphylococcus aureusincluding methicillin resistant Staphylococcus aureus (MRSA) and methicillin sensitiveStaphylococcus aureus (MSSA) were collected from various hospitals of Lahore, Pakistan. Freshpolymorphonuclaer leucocytes were obtained from healthy individuals by centrifugation using FicolHypaque gradient combined with dextran sedimentation. Microbiological method was used for thedetermination of phagocytic index of phenotypic variants of Staphylococcus aureus. Results: Asignificant difference was observed between the phagocytic index of both bacterial groups. MSSAgroup showed the Mean±SD of 79.46%±3.9 while MRSA group showed 72.35%±2.5. Conclusion:Significant difference in phagocytic index indicates that it can be one of the mechanisms of MRSAto evade host immune system as compare to MSSA.Keywords: MRSA, MSSA, Phagocytic index, Polymorphonuclear leucocytes
Joachim D. Methicillin resistant Staphylococcus aureus
(MRSA): Diagnostic, clinical relevance and therapy. J Dtsch
Dermatol Ges. 2009. Available online at:
Garau J, Bouza E, Chastre J, Gudiol F, Harbarth S.
Management of methicillin- resistant Staphylococcus aureus
infections. Clin Microbiol Infect 2009;15:125–36.
Deurenberg RH, Stobberingh EE. The evolution of
Staphylococcus aureus. Infect Genet Evol 2008;8:747–63.
Ito T, Ma XX, Takeuchi F, Okuma K, Yuzawa H, Hiramatsu
K. Novel type V staphylococcal cassette chromosome mec
driven by a novel cassette chromosome recombinase, ccrC.
Antimicrob Agents Chemother 2004;48:2637–51.
Lieberman JM. Appropriate antibiotic use and why it is
important: the challenges of bacterial resistance. Pediatr
Infect Dis J 2003;22:1143–51.
Janeway J, Medzhitov R. Innate immune recognition. Annu
Rev Immunol 2002;20:197–16.
Choi EY, Santoso S, Chavakis T. Mechanisms of neutrophil
transendothelial migration. Front Biosci 2009;14:1596–605.
DeLeo FR, Diep BA, Otto M. Host defense and pathogenesis
in Staphylococcus aureus infections. Infect Dis Clin North
Cunnion KM, Zhang HM, Frank MM. Availability of
complement bound to Staphylococcus aureus to interact
with membrane complement receptors influences efficiency
of phagocytosis. Infect Immun 2003;71:656–62.
Rooijakkers SH, Van KP, Van SJ. Staphylococcal innate
immune evasion. Trends Microbiol 2005;13:596–601.
J Ayub Med Coll Abbottabad 2009;21(2)
Kantari C, Pederzoli M, Witko SV. The role of neutrophils
and monocytes in innate immunity. Contrib Microbiol
Annemick BS, Jeanette HW. Mac-1 (CD11b/CD18) is
essential for Fc receptor-mediated neutrophil cytotoxicity and
immunologic synapse formation. Blood 2001;97:2478–86.
Ofek I, Keisari J, Sharon N. Nonopsonic phagocytosis of
microorganisms. Annu Rev Microbiol 1995;49:239–76.
Witko-Sarsat V, Rieu P, Descamps-Latscha B, Lesavre P,
Halbwachs-Invest L. Neutrophils: molecules, functions and
pathophysiological aspects. Lab 2000; 80:617–53.
Chambers HF. The changing epidemiology of
Staphylococcus aureus. Emerg Infect Dis 2001;7:178–82.
Salgado MM, Pignatari AC, Bellinati-Pires R. Phagocytosis
and Killing of Epidemic Methicillin-Resistant
Staphylococcus aureus by Human Neutrophils and
Monocytes. Braz J Infect Dis 2004;8:80–9.
Pramanik T, Thapa M, Saikia TC. Effect of temperature on
phagocytic activity of neutrophils. Nepal Med Coll J
Bukovsky M, Koscova H, Dubnickova M, Sirotkova L.
Comparative study of disintegrated cells influence of
Staphylococcus aureus, Escherichia coli and Candida
albicans on human and mouse immune mechanisms. Bratisl
Lek Listy 2001;102:314–7.
Peacock JE, Moorman DR, Wenzel RP, Mandell GL.
Methicillin-resistant Staphylococcus aureus: Microbiologic
characteristics, antimicrobial susceptibilities, and assessment
of virulence of an epidemic strain. J Infect Dis
Jordens JZ, Duckworth GJ, Williams RJ. Production of
“virulence factors” by “epidemic” methicillin-resistant
Staphylococcus aureus in vitro. J Med Microbiol
Mekontso-Dessap A, Honoré S, Kirsch M, Plonquet A,
Fernandez E, Touqui L, et al. Blood neutrophil bactericidal
activity against methicillin-resistant and methicillin-sensitive
Staphylococcus aureus during cardiac surgery. Shock