Journal of Medical Bacteriology 2017. 6(1-2):45-55.

Phenotypic and Molecular Identification of Bacteria Involved in Decubitus Ulcers
Mehran Dolati, Sahar Honarmand jahromi, Abdolreza Javadi, Shohre Zare Kariz, Bahareh Ghobadi Saki


Background:    Bacterial secondary infection of pressure ulcers (bedsores), so called as decubitus ulcers, leads to ulcer development and it interferes with the healing process. Thus, such infections can be lethal due to the sepsis if no constructive medicinal measures regarded. Drug resistance of bacteria in pressure ulcers leads to healing inhibition. Molecular identification of bacteria involved in such infections seem necessary as culture and phenotypic approaches may result in misidentification. . The purpose of this study was to isolate and identify aerobic bacteria detected in bedsores in three Hospitals: Rasool-e-Akram, Imam Hossein and Tajrish Shohada Hospitals, Tehran, Iran.

Methods:    To this end, decubitus ulcer samples of 49 patients were obtained using sterile swabs. After direct microscopic examination, the swabs were used to streak BHI agar plates supplemented with %5 defibrinated sheep blood for enrichment of probable aerobic cultures. Bacterial isolates diagnosed by biochemical tests. Antibiotic susceptibility of the isolates determined based on CLSI guideline. For molecular identification, PCR amplification of the 16S rRNA gene performed using Eubacterial universal primers. Then, the PCR products were sequenced and the nucleotide sequences of the PCR products were analyzed by BLASTN similarity search program available at NCBI.

 Results:   Among the isolates, Pseudomonas aeruginosa (36%) had the highest frequency, followed by Staphylococcus aureus (32%) and Escherichia coli (30%). The frequencies of Klebsiella pneumonia and Proteus spp. were 10% and 8%, respectively. Most of the isolated bacteria showed a widespread antibiotic resistance. Molecular identification of the bacterial isolates resulted in 6 isolates of Escherichia coli, two isolates of each of Proteus mirabilis and Shigella spp., 4 isolates of Enterobacter cloacae, and 1 isolate of each of Cronobacter sakazakii and Morganella morganii.

Conclusion:   Results showed that Pseudomonas aeruginosa and Staphylococcus aureus as the most frequent bacterial species detected in pressure ulcers; however, bacterial prevalence may be different in different hospital wards.


PCR, 16S rRNA, Pressure ulcer, diagnosis, Bacterial secondary infection, Characterization.

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Rowling JT. Pathological changes in mummies. Proc R Soc Med 1961; 54(5): 409.

Zulkowski K, Langemo D, Posthauer ME. Coming to consensus on deep tissue injury. Adv Skin Wound Care 2005; 18(1): 28-9.

Bansal C, Scott R, Stewart D, et al. Decubitus ulcers: a review of the literature. Int J Dermatol 2005; 44(10): 805-10.

Gelis A, Dupeyron A, Legros P, et al. Pressure ulcer risk factors in persons with SCI: Part I: Acute and rehabilitation stages. Spinal Cord 2009; 47(2): 99-107.

Reddy M, Gill SS, Kalkar SR, et al. Treatment of pressure ulcers: a systematic review. Jama 2008; 300(22): 2647-62.

Guihan M, Garber SL, Bombardier CH, et al. Predictors of pressure ulcer recurrence in veterans with spinal cord injury. J Spinal Cord Med 2008; 31(5): 551-9.

Shea JD. Pressure Sores Classification and Management. Clin Orthop Relat Res 1975; 112: 89-100.

Ebright JR. Microbiology of chronic leg and pressure ulcers: clinical significance and implications for treatment. Nurs. Clin. North Am 2005; 40(2): 207-16.

Wolcott RD, Ehrlich GD. Biofilms and chronic infections. Jama 2008; 299(22): 2682-4.

Ramos NL, Dzung DTN, Stopsack K, et al. Characterisation of uropathogenic Escherichia coli from children with urinary tract infection in different countries. Eur J Clin Microbiol Infect Dis 2011; 30(12): 1587-93.

Talebi M, Rahimi F, Katouli M, et al. Prevalence and antimicrobial resistance of enterococcal species in sewage treatment plants in Iran. Water Air Soil Pollut 2007; 185(1-4): 111.

Rahimi F, Bouzari M, Katouli M. Prophage and antibiotic resistance profiles of methicillin-resistant Staphylococcus aureus strains in Iran. Arch Virol 2012; 157(9): 1807-11.

Saba F, Papizadeh M, Khansha J, et al. A rapid and reproducible genomic DNA extraction protocol for sequence-based identification of archaea, bacteria, cyanobacteria, diatoms, fungi, and green algae. J Med bacteriol 2017; 5(3-4): 22–8.

Papizadeh M, Roayaei Ardakani M, Motamedi H (2017) Growth-phase dependent biodesulfurization of dibenzothiophene by Enterobacter sp. strain NISOC-03. Pollution 3(1):101–111.

Woo P, Lau S, Teng J, et al. Then and now: use of 16S rDNA gene sequencing for bacterial identification and discovery of novel bacteria in clinical microbiology laboratories. Clin Microbiol Infect 2008; 14(10): 908-34.

Fazli M, Bjarnsholt T, Kirketerp-Møller K, et al. Nonrandom distribution of Pseudomonas aeruginosa and Staphylococcus aureus in chronic wounds. J Clin Microbiol 2009; 47(12): 4084-9.

Jones SG, Edwards R, Thomas DW. Inflammation and wound healing: the role of bacteria in the immuno-regulation of wound healing. Int J Low Extrem Wounds 2004; 3(4): 201-8.

Robson MC. Wound infection: a failure of wound healing caused by an imbalance of bacteria. Surg Clin North Am 1997; 77(3): 637-50.

AhmadiNejad M, Rafiei H. Pressure ulcer incidence in intensive care unit patients in Bahonar Hospital, Kerman. J Iran Soc Anaesthesiol Intensive Care. 2011; 57: 10-6.

Cho I, Noh M. Braden scale: evaluation of clinical usefulness in an intensive care unit. J Adv Nurs 2010; 66(2): 293-302.

Shahin ES, Dassen T, Halfens RJ. Pressure ulcer prevention in intensive care patients: guidelines and practice. J Eval Clin Pract 2009; 15(2): 370-4.

Hossain S, Khundkar S. Bacteriological status of pressure sore-A study of 50 cases. Bangladesh Journal of Plastic Surgery 2013; 3(1): 19-23.

Keller PB, Wille J, van Ramshorst B, et al. Pressure ulcers in intensive care patients: a review of risks and prevention. Intensive Care Med 2002; 28(10): 1379-88.

Medicare Cf, Services M. Proposed changes to the hospital inpatient prospective payment systems and fiscal year 2009. 2008.

O’Meara S, Al-Kurdi D, Ologun Y, et al. Antibiotics and antiseptics for venous leg ulcers. Cochrane Database Syst Rev 2013; 12.

Ousey K, McIntosh C. Topical antimicrobial agents for the treatment of chronic wounds. Br J Community Nurs 2009; 14(Sup4): S6-S15.

Kirketerp-Møller K, Jensen PØ, Fazli M, et al. Distribution, organization, and ecology of bacteria in chronic wounds. J Clin Microbiol 2008; 46(8): 2717-22.

Rhoads DD, Cox SB, Rees EJ, et al. Clinical identification of bacteria in human chronic wound infections: culturing vs. 16S ribosomal DNA sequencing. BMC Infect Dis 2012; 12(1): 1.

Price LB, Liu CM, Melendez JH, et al. Community analysis of chronic wound bacteria using 16S rRNA gene-based pyrosequencing: impact of diabetes and antibiotics on chronic wound microbiota. PloSOne 2009; 4(7): e6462.

Davies CE, Hill KE, Wilson MJ, et al. Use of 16S ribosomal DNA PCR and denaturing gradient gel electrophoresis for analysis of the microfloras of healing and nonhealing chronic venous leg ulcers. J Clin Microbiol 2004; 42(8): 3549-57.


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