Antimicrobial susceptibility, virulence factors and biofilm formation among Staphylococcus aureus strains from hospital infections in Kerman, Iran

Yıl 2014, Cilt: 4 Sayı: 04, 152 - 158, 01.12.2014

Mohammad Reza Shakibaie Yasser Golkari Gholamabas Salagegheh

https://doi.org/10.5799/ahinjs.02.2014.04.0159

Cited By: 1

Öz

Amaç: Bu çalışma hastane kaynaklı Staphylococcus aureus suşlarının antimicrobial duyarlılık, virülans faktör ve biyofilm oluşturma özelliklerini belirlemeyi hedeflemektedir. Metotlar: İran, Kerman’da 30 adet, tekrarlamayan S. aureus suşu hastanelerden izole edildi. Antimicrobial duyarlılıklar disk diffüzyon metoduyla CLSI rehberinin sınırdeğerlerine göre çalışıldı. Vankomisin ve metisilin için minimum inhibitor konsantrasyonu (MİK) sıvı mikrodilüsyon ve E-test prosedürleri ile belirlendi. Bu suşlarla birlikte olan virülans faktörleri (proteaz, DNaz, lesitinaz, kapsül ve hemoliz) çalışıldı. Biyofilm değerlendirmesi mikrotitre tekniği ile miktarı belirleme şeklinde yapıldı. Bulgular: Toplam olarak 14 (% 46, 7) S. aureus suşu alt solunum yollarından, altı suş (% 20,0) üriner sistemden ve kalan 10 suş (% 33,3) yaralar, kan ve ortopedi hastalarından izole edildi. Bütün suşlar tigesikline duyarlıydı, sekiz suş (% 26,7) metisiline dirençli (MRSA) bulundu ve dört suş (% 13,3) vankomisine azalmış duyarlılık gösterdi. Suşların hiç biri vankomisine dirençli değildi (p≤0.05). MİK sonuçları; vankomisin için suşlardan dördünde (% 13,3) MİK 4 µg/mL olarak bulunurken beşinde (% 16,6) metisilin için MİK 32 µg/mL olarak bulundu. Suşlar aynı zamanda amoksisilin/klavulanik asit, tekrasiklin ve tobramisine dirençli idiler. MSSA suşları ile karşılaştırıldığında MRSA suşlarından 6’si (% 75,0) lesitinaz, yedisi (% 96,7) proteaz ve DNaz aktivitesi gösterdi. Yirmi suş (% 66,7) kuvvetli, yedi suş (% 23,3) orta ve üç suş (% 10,0) zayıf biyofilm yapmaktaydı.Sonuç: Bu sonuçlardan bu enfeksiyonlarda tedavi seçeneklerinin sınırlı olduğu anlaşılmaktadır. Bundan dolayı vankomisine duyarlılığı azalmış MRSA suşlarının etken olduğu enfeksiyonların izlenmesi ve yönetimi bu suşların hastane ortamına yayılmasının kontrolüyle yapılmalıdır

Anahtar Kelimeler

Staphylococcus aureus, metisilin direnci, MİK, virülans faktörleri, biyofilm

Antimicrobial susceptibility, virulence factors and biofilm formation among Staphylococcus aureus isolates from hospital infections in Kerman, Iran

Öz

Objective: The aims of present study were to determine the antimicrobial susceptibility, virulence factors and biofilm formation among MRSA hospital isolates of Staphylococcus aureus. Methods: Thirty non-repetitive strains of S. aureus isolated from three hospitals in Kerman, Iran. Antimicrobial sus­ceptibility was determined by disk diffusion breakpoints method according to CLSI guideline. The minimum inhibitory concentration (MIC) of vancomycin and methicillin were measured by the broth microdilution and E-test procedures. Virulence factors (protease, DNase, lecithinase, capsule and hemolysis) associated with the above isolates was studied. Biofilm was quantified by microtiter technique. Results: In total, 14 (46.7%) S. aureus were isolated from lower respiratory tract, six (20.0%) from urinary tract and re­maining 10 (33.3%) were recovered from wounds, blood and orthopedic patients. All of the isolates were susceptible to tigecycline, eight (26.7%) were found to be resistant to methicillin (MRSA) and 4 (13.3%) showed reduced susceptibility to vancomycin. No any vancomycin resistant isolate was detected (p≤0.05). MIC results showed that four of the isolates (13.3%) exhibited MIC 4 μg/mL to vancomycin while, five (16.6%) demonstrated MIC 32 μg/mL to methicillin. The iso­lates were also resistant to amoxicillin/clavulanic acid, tetracycline and tobramycin. It was found that, six (75 %) of MRSA strains produced lecithinase, seven (96.7%) demonstrated protease and DNase activities as compared to MSSA isolates. Biofilm analysis revealed that twenty (66.7%) isolates formed strong, seven (23.3%) formed moderate and three (10.0%) had weak biofilm. Conclusion: From the results, it can be concluded that, treatment options available for these infections are limited; therefore, monitoring, and management of infections due to MRSA with reduced susceptibility to vancomycin, must be done in order to control spread of these strains in the hospital environment.

Anahtar Kelimeler

Staphylococcus aureus, methicillin resistance, MIC, virulence factor, biofilm

Kaynakça

• Rubinstein E, Kollef MH, Nathwani D. Pneumonia caused by methicillin-resistant Staphylococcus aureus. Clin Infect Dis 2008; 46:378-385.
• David MZ, Daum RS. Community associated methicillin resis- tant Staphylococcus aureus: epidemiology and clinical con- sequences of an emerging epidemic. Clinic Microbiol Rev 2010; 23:616-687.
• National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 through June 2003, issued August 2003. Am J Infect Control 2003; 31: 481-498.
• Klevens RM, Morrison MA, Nadle J, et al. Invasive methicil- lin-resistant Staphylococcus aureus infections in the United States. JAMA 2007; 298:1763-1771.
• Fischbach MA, Walsh CT. Antibiotics for emerging pathogens. Science 2009; 325:1089-1093.
• Rodvold KA and McConeghy KW. Methicillin resistant Staphy- lococcus aureus therapy: past, present, and future. Clin In- fect Dis 2014; 58: S20-S27.
• Weinstein RA and Fridkin SK. Vancomycin intermediate and resistant Staphylococcus aureus: What the infectious dis- ease specialist needs to know. Clin Infect Dis 2001; 32 (1): 108-115.
• Hiramatsu K, Hanaki H, Ino T, et al. Methicillin-resistant Staph- ylococcus aureus clinical strain with reduced vancomycin susceptibility. Antimicrob Chemother 1997; 40: 135-136.
• Brumfitt W, Hamilton-Miler JM. The worldwide problem of methicillin resistant Staphylococcus aureus. Drugs Exp Clin Res 1990; 16: 205-14.
• Noskin GA, Rubin RJ, Schentag JJ, et al. The burden of Staphylococcus aureus infections on hospitals in the United States. Arch Intern Med 2005; 65:1756-1761.
• Azimian A, Najar-pirayeh S, Mirab-Samiee S, et al. Occur- rence of methicillin resistant Staphylococcus aureus (MRSA) among clinical samples in Tehran-Iran and its correlation with polymorphism of specific accessory gene regulator (agr) groups. Braz J Microbiol 2012; 43:779-785.
• Hasani A, Sheikhalizadeh V, Hasani A, et al. Methicillin re- sistant and susceptible Staphylococcus aureus: Appraising therapeutic approaches in the Northwest of Iran. Iran J Mi- crobiol 2013; 5:56-62.
• Melzer M, Eykyn SJ, Gransden WR, Chinn S. Is methicillin- resistant Staphylococcus aureus more virulent than methi- cillin-susceptible S. aureus? A comparative cohort study of British patients with nosocomial infection and bacteremia. Clin Infect Dis 2003; 37: 1453-1460.
• Blot S, Vandewoude KH, Hoste EA, Colardyn FA. Patients with bacteremia involving methicillin susceptible and meth- icillin-resistant Staphylococcus aureus. Arch Intern Med 2002; 162:2229-2235.
• Cabrera-Contreras R, Morelos-Ramírez R, Galicia-Macho N, et al. Antibiotic resistance and biofilm production in Staphylo- coccus epidermidis strains, isolated from a tertiary care hos- pital in Mexico City. SRN Microbiology 2013; http: //dx.doi. org/ 10.1155/2013/918921.
• Shikh-Bardsiri H, and Shakibaie MR. Antibiotic resistance pattern among biofilm producing and non-producing Proteus strains isolated from hospitalized patients; Matter of Hospital Hygiene and Antimicrobial Stewardship. Pak J Biol Scienc 2013; 16 (22):1496-1502.
• Kateete D, Kimani C, Katabazi F, et al. Identification of Staph- ylococcus aureus: DNase and manitol salt agar improve the efficiency of the tube coagulase test. Ann Clinic Microbiol and Antimicrob 2010; 9:23-28.
• Clinical Laboratory Standards Institute (CLSI) (2012) Guide- lines. Performance Standards for antimicrobials disk sus- ceptibility tests. Approved standard. 11th ed. CLSI document M100-S22. Wayne, PA: CLSI.
• Bjorklind A, and Arvids S. Occurrence of an extracellular ser- ine proteinase among Staphylococcus aureus strains. Acta Pathol Microbiol Scand 1977; 5:277-280.
• Matos JE, Harmon RJ, Langlois BE: Lecithinase reaction of Staphylococcus aureus strains of different origin on Baird- Parker medium. Lett Appl Microbiol 1995; 21:334-335.
• Welch PG, Fattom A, Moore J, et al. Safety and immuno- genicity of Staphylococcus aureus type 5 capsular polysac- charide Pseudomonas aeruginosa a recombinant exoprotein a conjugate vaccine in patients on hemodialysis. Am Soc Nephrol 1996; 7:247-253.
• Shakibaie M, Forootanfar H, Yaser Golkari Y, et al. Anti-bio- film activity of biogenic selenium nanoparticles and selenium dioxide against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis. Journal of Trace Elements in Medicine and Biology 2015; 29: 235-241. doi:10.1016/j.jtemb.2014.07.020
• Stepanovic S, Vukovic D, Hola V, et al. Quantification of bio- film in microtiter plates: overview of testing conditions and practical recommendations for assessment of biofilm pro- duction by Staphylococci. APMIS 2007; 115: 891-899.
• Fatholahzadeh B, Emaneini M, Gilbert G, et al. Staphylo- coccal Cassette Chromosome mec (SCCmec) Analysis and Antimicrobial Susceptibility Patterns of Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates in Tehran, Iran. Mi- crob Drug Resist 2008; 14: 217-220.
• Japoni A, Alborzi A, Orafa F, et al. Distribution Patterns of Methicillin Resistance genes (mecA) in Staphylococcus au- reus isolated from clinical specimens. Iranian Biomedical Journal 2004; 8: 173-178.
• Shakibaie MR, Mansouri S, Hakak S. Plasmid Pattern of an- tibiotic resistance in β-lactamase producing Staphylococcus aureus isolated from hospitals in Kerman, Iran. Archive of Iranian Medicine 1999; 2:93-97.
• Lin SY, Chen TC, Chen FJ, et al. Molecular epidemiology and clinical characteristics of hetero-resistant vancomycin intermediate Staphylococcus aureus bacteremia in a Taiwan medical center. Microbiol Immunol Infect 2012; 45:435-441.
• Golan Y, Baez-Giangreco C, O’Sullivan C, et al. Trends in vancomycin susceptibility among consecutive MRSA iso- lates. In: Abstracts of the Forty-fourth Annual Meeting of the Infectious Diseases Society of America, Toronto, Ontario, Canada, 2006. Abstract LB-11, p. 238. Infectious Diseases Society of America, Alexandria, VA, USA.
• Soriano A, Martínez JA, Mensa J, et al. Pathogenic signifi- cance of methicillin resistance for patients with Staphylococ- cus aureus bacteremia. Clin Infect Dis 2000; 30:368-73.
• Chen YH, Liu CU, Ko WC, et al. Trends in the susceptibility of methicillin-resistant Staphylococcus aureus to nine antimi- crobial agents, including ceftobiprole, nemonoxacin, and ty- rothricin: results from the Tigecycline In Vitro Surveillance in Taiwan (TIST) study, 2006-2010. Eur J Clin Microbiol Infect Dis 2014; 33:233-239.
• Rezaei M, Moniri R, Mousavi SA et al. Prevalence of bio- film formation among methicillin resistance Staphylococcus aureus iso lated from nasal carriers. Jundishapur Journal of Microbiology 2013; 6(6): e9601. DOI: 10.5812/jjm.9601