Evaluation of Antibiotic Resistance Pattern, Alginate and Biofilm Production in Clinical Isolates of Pseudomonas aeruginosa
Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa.
Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively.
Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were Multidrug-Resistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates.
Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.
2. Owlia P, Nosrati R, Alaghehbandan R, Lari AR (2014). Antimicrobial susceptibility differences among mucoid and non-mucoid Pseudomonas aeruginosa isolates. GMS Hyg Infect Control, 9(2): Doc13.
3. Ryan K, Ahmad N, Alspaugh JA et al (2014). Sherris Medical Microbiology. 6th edition. McGraw-Hill Education. New York.
4. Hall-Stoodley L, Costerton JW, Stoodley P (2004). Bacterial biofilms: from the natural environment to infectious diseases. Nat Rev Microbiol, 2(2): 95-108.
5. Ghotaslou R, Salahi Eshlaqghi B (2013). Biofilm of Pseudomonas aeruginosa and New Preventive Measures and Anti- Biofilm Agents. J Rafsanjan Univ Med Sci,12(9): 747-68.
6. Cotton LA, Graham RJ, Lee RJ (2009). The role of alginate in P. aeruginosa PAO1 biofilm structural resistance to gentamicin and ciprofloxacin. J Exp Microbiol Immunol, 13: 58-62.
7. May TB, Shinabarger D, Maharaj R et al (1991). Alginate synthesis by Pseudomonas aeruginosa: a key pathogenic factor in chronic pulmonary infections of cystic fibrosis patients. Clin Microbiol Rev, 4(2): 191-206.
8. Tille P (2013). Bailey & Scott's Diagnostic Microbiology. 13th edition. Mosby. Missouri.
9. Saderi H, Owlia P (2015). Detection of multidrug resistant (MDR) and extremely drug resistant (XDR) P. aeruginosa isolated from patients in Tehran, Iran. Iran J Pathol, 10(4): 265-71.
10. Clinical and Laboratory Standards Institute (CLSI) (2018) Performance Standards for Antimicrobial Susceptibility Testing, 28th edition. CLSI supplement M100.
11. Magiorakos AP, Srinivasan A, Carey RB et al (2012). Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance. Clin Microbiol Infect, 18(3): 268-81.
12. Müsken M, Di Fiore S, Römling U et al (2010). A 96-well-plate–based optical method for the quantitative and qualitative evaluation of Pseudomonas aeruginosa biofilm formation and its application to susceptibility testing. Nat Protoc, 5(8): 1460-9.
13. Knutson CA, Jeanes A (1968). A new modification of the carbazole analysis: application to heteropolysaccharides. Anal Biochem, 24(3): 470-81.
14. Gómez MI, Prince A (2007). Opportunistic infections in lung disease: Pseudomonas infections in cystic fibrosis. Curr Opin Pharmacol, 7(3): 244-51.
15. Pournajaf A, Razavi S, Irajian G et al (2018). Integron types, antimicrobial resistance genes, virulence gene profile, alginate production and biofilm formation in Iranian cystic fibrosis Pseudomonas aeruginosa isolates. Infez Med, 26(3): 226-36.
16. Gilpin D, Graham J, Elborn J et al (2008). Biofilm formation and antimicrobial susceptibility of P. aeruginosa isolates cultured before and after antibiotic treatment of an acute exacerbation of pulmonary infection. J Cyst Fibros, 7: S39.
17. Valadbeigi H, Sadeghifard N, Rafiei Tabatabaei R et al (2012). A Study on The Frequency of Toxin A, Alginate Genes, And of Clinical Pseudomonas aeroginosa Strains. J Ilam Univ Med Sci, 20(1): 58-64.
18. Pourzereshki N, Naserpour T, Peymani A (2015). Presence of alginate among multidrug resistant Pseudomonas aeruginosa isolated from clinical samples in Qazvin and Tehran hospitals. J Clin Res Paramed Sci, 3(4): 257-63.
19. Heidari H, Hadadi M, Ebrahim-Saraie HS et al (2018). Characterization of virulence factors, antimicrobial resistance patterns and biofilm formation of Pseudomonas aeruginosa and Staphylococcus spp. strains isolated from corneal infection. J Fr Ophtalmol, 41(9): 823-9.
|Issue||Vol 50 No 2 (2021)|
|Alginate Antibiotic resistance Biofilm Pseudomonas aeruginosa|
|Rights and permissions|
|This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.|