Prevalence of methicillin resistance and virulence determinants of Staphylococcus aureus in diabetic foot ulcers


  • Sumeet Sandhu Department of Infectious Diseases Program, Institute of Health & Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
  • Irani Udeshika Rathnayake Department of Infectious Diseases Program, Institute of Health & Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
  • Flavia Huygens Department of Infectious Diseases Program, Institute of Health & Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia


Diabetic foot ulcer, Polymerase chain reaction, Staphylococcus aureus, Methicillin resistant Staphylococcus aureus, Virulence


Background: Diabetic foot ulceration (DFU) is a multifactorial process and is responsible for considerable morbidity and contributes to the increasing cost of health care worldwide. The diagnosis and identification of these ulcers remains a complex problem. Bacterial infection is promoted in the diabetic foot wound by decreased vascular supply and impaired host immune response. As conventional clinical microbiological methods are time-consuming and only identifies about 1% of the wound microbiota, detection of bacteria present in DFUs using molecular methods is highly advantageous and efficient. The aim of this study was to assess the virulence and methicillin resistance profiles of Staphylococcus aureus detected in DFUs using DNA-based methods.

Methods: A total of 223 swab samples were collected from 30 patients from March to October 2012. Bacterial DNA was extracted from the swab samples using standard procedures and was used to perform polymerase chain reaction (PCR) using specific oligonucleotide primers. The products were visualized using agarose gel electrophoresis.

Results: S. aureus was detected in 44.8% of samples. 25% of the S. aureus was methicillin-resistant S. aureus harboring the mecA gene. The alpha-toxin gene was present in 85% of the S. aureus positive samples. 61% of the S. aureus present in DFU samples harbored the exfoliatin factor A gene. Both the fibronectin factor A and fibronectin factor B gene were detected in 71% and 74% of the S. aureus positive samples.

Conclusions: DNA-based detection and characterization of bacteria in DFUs are rapid and efficient and can assist in accurate, targeted antibiotic therapy of DFU infections. The majority of S. aureus detected in this study were highly virulent and also resistant to methicillin. Further studies are required to understand the role of S. aureus in DFU trajectory.


Mendes JJ, Marques-Costa A, Vilela C, Neves J, Candeias N, Cavaco-Silva P, et al. Clinical and bacteriological survey of diabetic foot infections in Lisbon. Diabetes Res Clin Pract. 2012;95(1):153-61.

Eleftheriadou I, Tentolouris N, Argiana V, Jude E, Boulton AJ. Methicillin-resistant Staphylococcus aureus in diabetic foot infections. Drugs. 2010;70(14):1785-97.

Pappu AK, Sinha A, Johnson A. Microbiological profile of diabetic foot ulcer. Calicut Med J. 2011;9:1-4.

Frykberg RG. An evidence-based approach to diabetic foot infections. Am J Surg. 2003;186(5A):44S-54.

Roberts AD, Simon GL. Diabetic foot infections: the role of microbiology and antibiotic treatment. Semin Vasc Surg. 2012;25(2):75-81.

Kandemir O, Akbay E, Sahin E, Milcan A, Gen R. Risk factors for infection of the diabetic foot with multi-antibiotic resistant microorganisms. J Infect. 2007;54(5):439-45.

Dowd SE, Wolcott RD, Sun Y, McKeehan T, Smith E, Rhoads D. Polymicrobial nature of chronic diabetic foot ulcer biofilm infections determined using bacterial tag encoded FLX amplicon pyrosequencing (bTEFAP). PLoS One. 2008;3(10):e3326.

Zubair M, Malik A, Ahmad J. Incidence, risk factors for amputation among patients with diabetic foot ulcer in a North Indian tertiary care hospital. Foot (Edinb). 2012;22(1):24 30.

Crouzet J, Lavigne JP, Richard JL, Sotto A, Nîmes University Hospital Working Group on the Diabetic Foot (GP30). Diabetic foot infection: a critical review of recent randomized clinical trials on antibiotic therapy. Int J Infect Dis. 2011;15(9):e601-10.

Murali TS, Paul B, Parikh H, Singh RP, Kavitha S, Bhat MK, et al. Genome sequences of four clinical Staphylococcus aureus strains with diverse drug resistance profiles isolated from diabetic foot ulcers. Genome Announc. 2014;2(2).

Zubair M, Malik A, Ahmad J. Prevalence of metallo-ß-lactamase-producing Pseudomonas aeruginosa isolated from diabetic foot ulcer patients. Diabetes Metab Syndr. 2011;5(2):90-2.

Gadepalli R, Dhawan B, Sreenivas V, Kapil A, Ammini AC, Chaudhry R. A clinico-microbiological study of diabetic foot ulcers in an Indian tertiary care hospital. Diabetes Care. 2006;29(8):1727-32.

Basu S, Ramchuran Panray T, Bali Singh T, Gulati AK, Shukla VK. A prospective, descriptive study to identify the microbiological profile of chronic wounds in outpatients. Ostomy Wound Manage. 2009;55(1):14-20.

Chand G, Mishra AK, Kumar S, Agarwal A. Diabetic foot. Clinical Queries. Nephrology. 2012;0102:144-50.

Richard JL, Sotto A, Jourdan N, Combescure C, Vannereau D, Rodier M, et al. Risk factors and healing impact of multidrug-resistant bacteria in diabetic foot ulcers. Diabetes Metab. 2008;34:363-9.

Gardner SE, Hillis SL, Heilmann K, Segre JA, Grice EA. The neuropathic diabetic foot ulcer microbiome is associated with clinical factors. Diabetes. 2013;62(3):923-30.

Yates C, May K, Hale T, Allard B, Rowlings N, Freeman A, et al. Wound chronicity, inpatient care, and chronic kidney disease predispose to MRSA infection in diabetic foot ulcers. Diabetes Care. 2009;32(10):1907-9.

Ambrosh A, Haefner S, Jude E, Lobmann R. Diabetic foot infections: microbiological aspects, current and future antibiotic therapy focussing on methicillin-resistant Staphyloccus aureus. Int Wound J. 2011;8(6):567-77.

Otto M. Staphylococcus aureus toxins. Curr Opin Microbiol. 2014;17:32-7.

Djahmi N, Messad N, Nedjai S, Moussaoui A, Mazouz D, Richard JL, et al. Molecular epidemiology of Staphylococcus aureus strains isolated from inpatients with infected diabetic foot ulcers in an Algerian University Hospital. Clin Microbiol Infect. 2013;19(9):E398-404.

Bowling FL, Jude EB, Boulton AJ. MRSA and diabetic foot wounds: contaminating or infecting organisms? Curr Diab Rep. 2009;9(6):440-4.

Goldstein EJ, Citron DM, Nesbit CA. Diabetic foot infections. Bacteriology and activity of 10 oral antimicrobial agents against bacteria isolated from consecutive cases. Diabetes Care. 1996;19(6):638-41.

Lipsky BA, Richard JL, Lavigne JP. Diabetic foot ulcer microbiome: one small step for molecular microbiology one giant leap for understanding diabetic foot ulcers? Diabetes. 2013;62(3):679-81.

Huygens F, Inman-Bamber J, Nimmo GR, Munckhof W, Schooneveldt J, Harrison B, et al. Staphylococcus aureus genotyping using novel real-time PCR formats. J Clin Microbiol. 2006;44(10):3712-9.

Ge Y, MacDonald D, Hait H, Lipsky B, Zasloff M, Holroyd K. Microbiological profile of infected diabetic foot ulcers. Diabet Med. 2002;19(12):1032-4.

El-Tahawy AT. Bacteriology of diabetic foot. Saudi Med J. 2000;21(4):344-7.

Tentolouris N, Jude EB, Smirnof I, Knowles EA, Boulton AJ. Methicillin-resistant Staphylococcus aureus: an increasing problem in a diabetic foot clinic. Diabet Med. 1999;16(9):767-71.

Abdulrazak A, Bitar ZI, Al-Shamali AA, Mobasher LA. Bacteriological study of diabetic foot infections. J Diabetes Complications. 2005;19(3):138-41.

Stanaway S, Johnson D, Moulik P, Gill G. Methicillin resistant Staphylococcus aureus (MRSA) isolation from diabetic foot ulcers correlates with nasal MRSA carriage. Diabetes Res Clin Pract. 2007;75(1):47-50.

Aragón-Sánchez FJ, Cabrera-Galván JJ, Quintana Marrero Y, Hernández-Herrero MJ, Lázaro-Martínez JL, García Morales E, et al. Outcomes of surgical treatment of diabetic foot osteomyelitis: a series of 185 patients with histopathological confirmation of bone involvement. Diabetologia. 2008;51(11):1962-70.

Mehta VJ, Kikani KM, Mehta SJ. Microbiological profile of diabetic foot ulcers and its antibiotic susceptibility pattern in a teaching hospital, Gujarat. Int J Basic Clin Pharmacol. 2014;3:92-5.




How to Cite

Sandhu, S., Rathnayake, I. U., & Huygens, F. (2017). Prevalence of methicillin resistance and virulence determinants of Staphylococcus aureus in diabetic foot ulcers. International Journal of Basic & Clinical Pharmacology, 3(6), 978–982. Retrieved from



Original Research Articles