Molecular detection of virulence factors (adhesion genes) in some Staphylococcus epidermidis locally isolated from different clinical sources


  • Rusul Muzher Hussein Department of Pharmacy, Al - Isra University College, Baghdad, Iraq.
  • Marrib Nazeeh Rasheed Genetic Engineering and Biotechnology Institute for Postgraduate Studies, University of Baghdad, Iraq.
  • Laith Fawzi Mahdi Al-karkh Health Directorate, Ministry of Health, Baghdad, Iraq.


Staphylococcus epidermidis, Virulence factor genes, Polymorphism


The icaA and icaD genes are found in bacterial cells. The icaA and icaD genes allow a bacterium to produce biofilm. Biofilms are an important virulence determinant in bacteria because biofilm formation significantly increases resistance to antibiotics and promotes host defenses. The ability of biofilm production can be determined by two phenotypic methods and genotypic methods of some adhesion factors (icaA and icaD). The phenotypic methods included the Congo-red agar (CRA) and Microtiter plate (Mtp). The results showed that 58 (69%) from 84 isolates were positive for producing biofilm on (CRA) plates and the 55 (65%) from 84 isolates were positive for adhesion and biofilm formation by (Mtp) on the O.D. 490nm. The extraction of DNA is subjected to use for polymerase chain reaction (PCR) which is used to amplify specific genes. The production of viscous layer of Staphylococcus epidermidis was investigated by using Molecular analysis (PCR) monoplex to amplify the virulence factor (icaA, icaD) genes (adhesion factors) with the amplicon sizes 188 bp and 198 bp, respectively. The results of the genes icaA and icaD represented as sixty for (46) 54.8% and thirty (30) 35.7%, respectively. The conclusion to these study detection to icaA and icaD genesis important virulence factor.


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Otto, M. (2009). Staphylococcus epidermidis - the 'accidental' pathogen. Nat. Rev. Microbiol., 7(8): 555–567.

Fey, P.D. & Olson, M.E. (2010). Current concepts in biofilm formation of Staphylococcus epidermidis. Future Microbiol., 5(6): 917–933.

Klingenberg, C., Aarag, E., Rønnestad, A., Sollid, J.E., Abrahamsen, T.G., Kjeldsen, G. & Flaegstad, T. (2005). Coagulase-negative staphylococcal sepsis in neonates. Association between antibiotic resistance, biofilm formation and the host inflammatory response. Pediatr. Infect. Dis. J., 24(9): 817–822.

Desgrandchamps, F., Moulinier, F., Daudon, M., Teillac, P. & Le Duc, A. (1997). An in vitro comparison of urease-induced encrustation of JJ stents in human urine. Br. J. Urol., 79(1): 24–27.

Yazdani, R., Oshaghi, M., Havayi, A., Pishva, E., Salehi, R., Sadeghizadeh, M. & Foroohesh, H. (2006). Detection of icaAD Gene and Biofilm Formation in Staphylococcus aureus Isolates from Wound Infections. Iran. J. Public Health, 35(2): 25–28.

El-Mahallawy, H.A., Loutfy, S.A., El-Wakil, M., El-Al, A.K. & Morcos, H. (2009). Clinical implications of icaA and icaD genes in coagulase negative staphylococci and Staphylococcus aureus bacteremia in febrile neutropenic pediatric cancer patients. Pediatr. Blood Cancer, 52(7): 824–828.

Cafiso, V., Bertuccio, T., Santagati, M., Campanile, F., Amicosante, G., Perilli, M.G., Selan, L., Artini, M., Nicoletti, G. & Stefani, S. (2004). Presence of the ica operon in clinical isolates of Staphylococcus epidermidis and its role in biofilm production. Clin. Microbiol. Infect., 10(12): 1081–1088.

Moyes, R.B., Reynolds, J. & Breakwell, D.P. (2009). Differential Staining of Bacteria: Gram Stain. Curr. Protoc. Microbiol., 15: A.3C.1-A.3C.8.

Türkyilmaz, S. & Kaya, O. (2006). Determination of some virulence factors in Staphylococcus spp. isolated from various clinical samples. Turkish J. Vet. Anim. Sci., 30(1): 127–132.

Anyanwu, N.C.J. & John, W.C. (2013). Conventional and Rapid Methods for Identification of Staphylococcus aureus from Clinical Specimens. American Journal of Biomedical and Life Sciences, 1(3): 41-43.

Freeman, D.J., Falkiner, F.R. & Keane, C.T. (1989). New method for detecting slime production by coagulase negative staphylococci. J. Clin. Pathol., 42(8): 872–874.

Bekir, K., Abdallah, F.B., Ellafi, A. & Bakhrouf, A. (2011). Adherence assays and slime production of Staphylococcus aureus strains after their incubation in seawater microcosms. Ann. Microbiol., 61(4): 819–823.

Brooks , G.F., Carroll, K.C., Butel, J.S. & Morse, S.A. (2007). Jawetz, Melnick & Adelberg’s Medical Microbiology. 24th ed., McGraw-Hill, New York. pp. 224-232.

Jain, A. & Agarwal, A. (2009). Biofilm production, a marker of pathogenic potential of colonizing and commensal staphylococci. J. Microbiol. Methods, 76(1): 88–92.

Prasad, S., Nayak, N., Satpathy, G., Nag, H.L., Venkatesh, P., Ramakrishnan, S., Ghose, S. & Nag, T.C. (2012). Molecular & phenotypic characterization of Staphylococcus epidermidis in implant related infections. Indian J. Med. Res., 136(3): 483–490.

Arciola, C.R., Campoccia, D., Baldassarri, L., Donati, M.E., Pirini, V., Gamberini, S. & Montanaro, L. (2006). Detection of biofilm formation in Staphylococcus epidermidis from implant infections. Comparison of a PCR-method that recognizes the presence of ica genes with two classic phenotypic methods. J. Biomed. Mater. Res. Part A, 76A(2): 425–430.

Chaieb, K., Mahdouani, K. & Bakhrouf, A. (2005). Detection of icaA and icaD loci by polymerase chain reaction and biofilm formation by Staphylococcus epidermidis isolated from dialysate and needles in a dialysis unit. J. Hosp. Infect., 61(3): 225–230.

Mack, D., Becker, P., Chatterjee, I., Dobinsky, S., Knobloch, J.K., Peters, G., Rohde, H. & Herrmann, M. (2004). Mechanisms of biofilm formation in Staphylococcus epidermidis and Staphylococcus aureus: functional molecules, regulatory circuits, and adaptive responses. Int. J. Med. Microbiol., 294: 203–212.

Maira-Litran, T., Kropec, A., Goldmann, D. & Pier, G.B. (2004). Biologic properties and vaccine potential of the staphylococcal poly-N-acetyl glucosamine surface polysaccharide. Vaccine, 22(7): 872–879.

O'Gara, J.P. (2007). ica and beyond: biofilm mechanisms and regulation in Staphylococcus epidermidis and Staphylococcus aureus. FEMS Microbiol. Lett., 270(2): 179–188.

Stevens, N.T., Tharmabala, M., Dillane, T., Greene, C.M., O'Gara, J.P. & Humphreys, H. (2008). Biofilm and the role of the ica operon and aap in Staphylococcus epidermidis isolates causing neurosurgical meningitis. Clin. Microbiol. Infect., 14(7): 719–722.

Ziebuhr, W., Heilmann, C., Götz, F., Meyer, P., Wilms, K., Straube, E. & Hacker, J. (1997). Detection of the intercellular adhesion gene cluster (ica) and phase variation in Staphylococcus epidermidis blood culture strains and mucosal isolates. Infect. Immun., 65(3): 890–896.

Cho, S.H., Naber, K., Hacker, J. & Ziebuhr, W. (2002). Detection of the icaADBC gene cluster and biofilm formation in Staphylococcus epidermidis isolates from catheter-related urinary tract infections. Int. J. Antimicrob. Agents, 19(6): 570–575.

Mempel, M., Feucht, H., Ziebuhr, W., Endres, M., Laufs, R. & Grüter, L. (1994). Lack of mecA transcription in slime-negative phase variants of methicillin-resistant Staphylococcus epidermidis. Antimicrob. Agents Chemother., 38(6): 1251–1255.

Mertens, A. & Ghebremedhin, B. (2013). Genetic determinants and biofilm formation of clinical Staphylococcus epidermidis isolates from blood cultures and indwelling devises. Eur. J. Microbiol. Immunol., 3(2): 111–119.

Růzicka, F., Holá, V., Votava, M., Tejkalová, R., Horvát, R., Heroldová, M. & Woznicová, V. (2004). Biofilm detection and the clinical significance of Staphylococcus epidermidis isolates. Folia Microbiol., 49(5): 596–600.


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Hussein, R. M., Rasheed, M. N., & Mahdi, L. F. (2018). Molecular detection of virulence factors (adhesion genes) in some Staphylococcus epidermidis locally isolated from different clinical sources. Advances in BioScience, 9(4), 106–110. Retrieved from