Gökhan METAN, Belgin ALTUN, Serhat ÜNAL, Pınar ZARAKOĞLU, Gülşen HASÇELİK

Hacettepe Üniversitesi erişkin hastanesi’nde izole edilen hastane enfeksiyonu etkeni metisiline dirençli Staphylococcus aureus suşlarının antimikrobiyallere duyarlılık, indüklenebilir makrolid-linkozamid-streptogramin B direnç ve klonal benzerlik durumları

Amaç: Metisiline dirençli Staphylococcus aureus (MRSA)’a bağlı gelişen nozokomiyal enfeksiyonlartedavide az sayıda seçenek olması nedeniyle önemli bir sorun oluşturmaktadır. Bu çalışmadaHacettepe Üniversitesi Erişkin Hastanesi’nde 2002-2004 yılları arasında hastane enfeksiyonu etkeniolarak izole edilen mecA geni pozitif 109 Staphylococcus aureus suşunun vankomisin, teikoplanin,linezolid, tigesiklin, eritromisin, gentamisin, siprofloksasin, rifampin, trimethoprim-sulfametoksazolve klindamisine karşı duyarlılık, indüklenebilir makrolid-linkozamid-streptogramin B (iMLSB) dirençve klonal benzerlik durumlarının belirlenmesi amaçlanmıştır.Yöntem ve gereçler: Farklı klinik örneklerden (58 kan, 45 püy, 6 kateter) izole edilen S. aureussuşlarının tür düzeyindeki tanımlaması Sceptor (Becton Dickinson, ABD) otomatize sistemi ileyapılmıştır. Otomatize sistemden metisiline dirençli S. aureus (MRSA) olarak rapor edilen izolatlarınmecA geni varlığı PZR yöntemiyle gösterilmiştir. Vankomisin, teikoplanin, linezolid ve tigesiklin içinduyarlılık testleri Etest (AB Biodisk, İsveç) ile üretici firma önerilerine uygun olarakgerçekleştirilmiştir. Diğer antibiyotiklere karşı duyarlılık disk difüzyon yöntemi ile belirlenip, sonuçlarCLSI kriterlerine göre yorumlanmıştır. İMLSB direnci çift disk difüzyon, suşlar arasındaki klonalbenzerlik ‘pulse field gel electrophoresis (PFGE)’ yöntemi ile belirlenmiştir.Bulgular: MRSA izolatlarının vankomisin, teikoplanin, linezolid ve tigesiklin MİK90 değerlerisırasıyla 2, 2, 2 ve 0,25 μg/ml ve tümü bu antibiyotiklere duyarlı olarak saptanmıştır. Bununla birliktetüm izolatlar gentamisin, siprofloksasin ve rifampisine yüksek oranda (≥% 90) dirençli; trimetoprim/sülfametaksazole % 89, klindamisine % 62 ve eritromisine % 46 oranında duyarlı bulunmuştur.MRSA izolatlarının % 13’ünde iMLSB direnci saptanmıştır. PFGE analizi sonucunda 13 farklı klonsaptanmış, izolatların % 80’inin belli bir tek klonda yer aldığı gözlenmiştir.Sonuç: Vankomisin, teikoplanin, linezolid ve tigesiklin hastanemizde izole edilen MRSA suşlarınakarşı yüksek düzeyde aktivite göstermektedir. MRSA enfeksiyonlarının tedavisi için etkinseçeneklerimiz olmasına rağmen, klonal analiz sonuçlarına göre hastalar arasında yüksek orandaçapraz bulaş saptanması endişe uyandırmaktadır. Bu durum enfeksiyon kontrol önlemlerine dahafazla dikkat göstermemiz gerektiğini göstermektedir.

Anahtar Kelimeler:

Metisiline Dirençli Staphylococcus aureus (MRSA), antibiyotiklere duyarlılık, makrolid-linkozamid-streptogramin direnci (iMLSB), pulse field gel electrophoresis (PFGE)

Antimicrobial susceptibility, inducible macrolide-lincosamide-streptogramin B, and clonal diversity patterns of nosocomial methicillin-resistant Staphylococcus aureus strains isolated in Hacettepe University adult hospital

Aim: Nosocomial infections due to methicillin resistant Staphylococcus aureus (MRSA) are an important problem with limited therapeutic options. The aim of this study was to determine the vancomycin, teicoplanin, linezolid, tigecycline, erythromycin, gentamicin, ciprofloxacin, rifampin, trimethoprim/sulfamethoxazole, and clindamycin susceptibility, inducible macrolide-lincosamide-streptogramin B (iMLSB) resistance, and clonal diversity patterns of 109 mecA positive Staphylococcus aureus strains isolated from patients with nosocomial infections in Hacettepe University Adult Hospital between 2002 and 2004. Materials and methods: The nosocomial isolates of S. aureus from various clinical samples (58 blood, 45 pus, 6 catheter) were identified by Sceptor (Becton Dickinson, USA) automated system. Polymerase chain reaction (PCR) was performed for the presence of mecA gene of the MRSA isolates. The susceptibility to vancomycin, teicoplanin, linezolid, and tigecycline was determined by Etest (AB Biodisk, Sweden) and to the other antibiotics by disk diffusion methods according to the CLSI recommendations. Inducible macrolide-lincosamide-streptogramin B (iMLSB) resistance phenotypes were determined by the double disk method. Pulse field gel electrophoresis (PFGE) was performed to examine the clonal diversity. Results: All MRSA strains were susceptible to vancomycin, teicoplanin, linezolid, and tigecycline with MIC90 (µg/mL) values of 2, 2, 2, and 0.25, respectively. The isolates were highly resistant (≥90%) to gentamicin, ciprofloxacin, and rifampin, whereas the susceptibility to trimethoprim/sulfamethoxazole was 89%, to clindamycin was 62%, and to erythromycin was 46%. iMLSB resistance was determined among 13% of the MRSA strains. Thirteen different clones were shown by PFGE, whereas 80% of the isolates were in a dominant clone. Conclusion: Vancomycin, teicoplanin, linezolid, and tigecycline were highly active against nosocomial isolates of MRSA in our hospital. Although these are effective therapeutic options for MRSA, the high rate of cross-contamination of the patients is a matter of concern. We should pay more attention to infection control practices.

Keywords:

Key words: Methicillin-resistant Staphylococcus aureus (MRSA), antibiotic susceptibility, inducible macrolide-lincosamide-streptogramin B (iMLSB), pulse field gel electrophoresis (PFGE),

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Lencastre H, Cauto I, Santos I, Melo-Cristino J, Torres-Pereira A, Tomasz A: Methicillin-Resistant Staphylococcus aureus disease in a Portuguese Hospital: Characterization of clonal types by a combination of DNA typing methods. Eur J Clin Microbiol Infect Dis 1994; 13: 64-73.
Tiemersma EW, Bronzwaer SL, Lyytikäinen O, Degener JE, Schrijnemakers P, Bruinsma N et al and European Antimicrobial Resistance Surveillance System Participants. Methicillin-resistant Staphylococcus aureus in Europe, 1999- 2002. Emerg Inf Dis 2004; 10(9): 1627-34.
Nosocomial Infections Surveillance Report of Hacettepe University Adult Hospital, 2000-2004.
Tosun I, Udo EE, Noronha B, Caylan R, Aydin F, Yetiskul S et al. Emergence of rifampicin resistance in methicillin-resistant Staphylococcus aureus isolated at a Turkish university hospital. Microb Drug Resist 2005; 11: 48-52.
Samra Z, Ofer O, Shmuely H. Susceptibility of methicillin- resistant Staphylococcus aureus to vancomycin, teicoplanin, linezolid, pristinamycin and other antibiotics. Isr Med Assoc J 2005; 7: 148-50.
Delialioglu N, Aslan G, Ozturk C, Baki V, Sen S, Emekdas G. Inducible clindamycin resistance in staphylococci isolated from clinical samples. Jpn J Infect Dis 2005; 58: 104-6.
Azap OK, Arslan H, Timurkaynak F, Yapar G, Oruc E, Gagir U. Incidence of inducible clindamycin resistance in staphylococci: first results from Turkey. Clin Microbiol Infect 2005; 11: 582- 584.
Siberry GK, Tekle T, Carroll K, Dick J. Failure of clindamycin treatment of methicillin-resistant Staphylococcus aureus expressing inducible clindamycin resistance in vitro. Clin Infect Dis 2003; 37: 1257-60.
Navaneeth BV. A preliminary in vitro study on inducible and constitutive clindamycin resistance in Staphylococcus aureus from a South Indian tertiary care hospital. Int J Infect Dis 2006; 10: 184-185.
Fridkin SK, Hageman J, McDougal LK, Mohammed J, Jarvis WR, Perl TM et al. Vancomycin-intermediate Staphylococcus aureus Epidemiology Study Group. Epidemiological and microbiological characterization of infections caused by Staphylococcus aureus with reduced susceptibility to vancomycin, United States, 1997-2001. Clin Infect Dis 2003; 36: 429-439.
Hiramatsu K, Hanaki H, Ino T, Yabuta K, Oguri T, Tenover FC. Methicillin-resistant Staphylococcus aureus clinical strain with reduced vancomycin susceptibility. J Antimicrob Chemother 1997; 40: 135-136.
Liu C, Chambers HF. Staphylococcus aureus with heterogeneous resistance to vancomycin: epidemiology, clinical significance, and critical assessment of diagnostic methods. Antimicrob Agents Chemother 2003; 47: 3040-3045.
Centers for Disease Control and Prevention. Vancomycin- resistant Staphylococcus aureus-Pennsylvania. MMWR Morbid Mort Week Rep. 2002; 51: 902.
Chang S, Sievert DM, Hageman JC, Boulton ML, Tenover FC, Downes FP et al and the Vancomycin-Resistant Staphylococcus aureus Investigative Team. Infection with vancomycin-resistant Staphylococcus aureus containing the vanA resistance gene. N Engl J Med 2003; 348: 1342-1347.
Ploy MC, Grelaud C, Martin C, De Lumley L, Denis F. First clinical isolate of vancomycin-intermediate Staphylococcus aureus in a French hospital. Lancet 1998; 351: 1212. 25. Reverdy
ME, Jarraud S, Bobin-Dubreux S, Boulton ML, Tenover
FC, Downes FP et al. Incidence of Staphylococcus aureus with
reduced susceptibility to glycopeptides in two French hospitals.
Clin Microbiol Infect 2001; 7: 267-272.
Borg MA, Zerafa R, Morrison D, Cuschieri P. Incidence of glycopeptide hetero-intermediate Staphylococcus aureus strains in Maltese hospitals. Clin Microbiol Infect 2005; 11: 405-7.
Sancak B, Ercis S, Menemenlioglu D, Colakoglu S, Hascelik G. Methicillin-resistant Staphylococcus aureus heterogeneously resistant to vancomycin in a Turkish university hospital. J Antimicrob Chemother 2005; 56: 519-23.
Nakipoglu Y, Derbentli S, Cagatay AA, Katranci H. Investigation of Staphylococcus strains with heterogeneous resistance to glycopeptides in a Turkish university hospital. BMC Infect Dis 2005; 5: 31.
Soriano A, Marco F, Martínez JA, Pisos E, Almela M, Dimova VP et al. Influence of vancomycin minimum inhibitory concentration on the treatment of methicillin-resistant Staphylococcus aureus bacteremia. Clin Infect Dis 2008; 46: 193- 200.
Jones RN, Ross JE, Castanheira M, Mendes RE. United States resistance surveillance results for linezolid (LEADER Program for 2007). Diagn Microbiol Infect Dis 2008; 62: 416-26.
Tsiodras S, Gold HS, Sakoulas G, Eliopoulos GM, Wennersten C, Venkataraman L et al. Linezolid resistance in a clinical isolate of Staphylococcus aureus. Lancet 2001; 358: 207-8.
Wilson P, Andrews JA, Charlesworth R, Walesby R, Singer M, Farrell DJ et al. Linezolid resistance in clinical isolates of Staphylococcus aureus. J Antimicrob Chemother 2003; 51: 186- 8.
Tunger A, Aydemir S, Uluer S, Cilli F. In vitro activity of linezolid and quinupristin/dalfopristin against gram-positive cocci. Indian J Med Res 2004; 120(6): 546-52.
Baysallar M, Kilic A, Aydogan H, Cilli F, Doganci L. Linezolid and quinopristin/dalfopristin resistance in vancomycin- resistant enterococci and methicillin-resistant Staphylococcus aureus prior to clinical use in Turkey. Int J Antimicrob Agents 2004; 23: 510-2.
Sharpe JN, Shively EH, Polk HC Jr. Clinical and economic outcomes of oral linezolid versus intravenous vancomycin in the treatment of MRSA-complicated, lower-extremity skin and soft-tissue infections caused by methicillin-resistant Staphylococcus aureus. Am J Surg 2005; 189: 425-8.
Weigelt J, Kaafarani HM, Itani KM, Swanson RN. Linezolid eradicates MRSA better than vancomycin from surgical-site infections. Am J Surg 2004; 188: 760-6.
Kohno S, Yamaguchi K, Aikawa N, Sumiyama Y, Odagiri S, Aoki N et al. Linezolid versus vancomycin for the treatment of infections caused by methicillin-resistant Staphylococcus aureus in Japan. J Antimicrob Chemother 2007; 60: 1361-9.
Hoban DJ, Bouchillon SK, Johnson BM, Johnson JL, Dowzicky MJ; Tigecycline Evaluation and Surveillance Trial (TEST Program) Group. In vitro activity of tigecycline against 6792 Gram-negative and Gram-positive clinical isolates from the global Tigecycline Evaluation and Surveillance Trial (TEST Program, 2004).Diagn Microbiol Infect Dis 2005; 52: 215-27.
Grolman DC. Therapeutic applications of tigecycline in the management of complicated skin and skin structure infections. Int J Infect Dis 2007; 11 Suppl 1: S7-15
Florescu I, Beuran M, Dimov R, Razbadauskas A, Bochan M, Fichev G et al. 307 Study Group. Efficacy and safety of tigecycline compared with vancomycin or linezolid for treatment of serious infections with methicillin-resistant Staphylococcus aureus or vancomycin-resistant enterococci: a Phase 3, multicentre, double-blind, randomized study. J Antimicrob Chemother 2008; 62 Suppl 1: i17-28.