High-level resistance to aminoglycoside, vancomycin, and linezolid in enterococci strains

Öz

Amaç: Bu çalışmada, enterokok suşlarının antibiyotik duyarlılık oranlarının saptanması, vankomisin duyarlı enterokok (VSE) ve vankomisin dirençli enterokok (VRE) suşlarındaki yüksek düzey aminoglikozid direncinin karşılaştırılması amaçlandı. Yöntemler: Haydarpaşa Numune Eğitim ve Araştırma Hastanesi kliniklerinden gönderilen örneklerden, laboratuvarımızda izole edilen 100 adet VRE, 100 adet VSE suşu çalışma kapsamına alındı.Bulgular: VRE suşlarının tümü Enterococcus faecium olarak tanımlanmış olup, VSE suşlarının ise %53’ü Enterococcus faecalis, %42’si E. faecium, %3’ü Enterococcus durans, %2’si Enterococcus avium olarak tespit edildi. VRE suşlarının tümünde yüksek düzey vankomisin direnci (MİK, >256 µg/ml) belirlendi, teikoplanin MİK değerleri incelendiğinde beş suş orta duyarlı (MİK, 16µg/ml), 95 suş dirençli (MİK, >32 µg/ml) olarak saptandı. VRE suşlarından biri linezolid dirençli (MİK, 12 µg/ml), biri ise orta duyarlı (MİK, 4 µg/ml) olarak saptandı, diğer suşlar duyarlı (MİK, <2 µg/ml) olarak değerlendirildi. VRE suşlarında yüksek düzey gentamisin direnci (YDGD) %83, yüksek düzey streptomisin direnci (YDSD) %89, YDSD ve YDGD birlikteliği %78 olarak bulundu. VSE suşlarında YDGD %42, YDSD %48, YDSD ve YDGD birlikteliği %36 olarak tespit edilmiştir. VRE’lerde YDAD’nin VSE suşlarına göre yüksek olduğu belirlendi (p<0,005). Sonuç: Enterokok suşlarında antimikrobiyal direnç artmaktadır. Bu yüzden hem YDAD hem de vankomisin içeren direnç paternlerinin izlenmesi gereklidir

Anahtar Kelimeler

• Enterococcus spp, vankomisin, linezolid, aminoglikozid, direnç

High-level resistance to aminoglycoside, vancomycin, and linezolid in enterococci strains

Abstract

Objective: This study sought to identify antibiotic susceptibility rates of enterococcal strains, and to compare the high-level resistance to aminoglycosides (HLAR) in vancomycin-sensitive enterococcal species (VSE) and vancomycin-resistant enterococcal species (VRE). Materials and Methods: The study included 100 VRE and 100 VSE strains recovered from the samples sent to laboratory from various departments of Haydarpasa Numune Training and Research Hospital. Results: All VRE strains were defined as Enterococcus faecium, although of the VSE strains, 53% were identified to be as Enterococcus faecalis, 42% E. faecium, 3% Enterococcus durans, and 2% Enterococcus avium. High-level resistance to vancomycin (MIC, >256 &micro;g/ml) was determined in all VRE strains and when analyzing MIC values for teicoplanin, five strains were found to be moderately susceptible (MIC, 16 &micro;g/ml) and 95 strains were resistant (MIC, >32 &micro;g/ml). Of the VRE strains, one was linezolid-resistant (MIC, 12 &micro;g/ml) and the other was intermediately susceptible (MIC, 4 &micro;g/ml) and remainders were evaluated to be susceptible (MIC, <2 &micro;g/ml). In VRE strains, high-level gentamicin resistance (HLGR) was found to be 83% and high-level streptomycin resistance (HLSR) 89%, association of HLSR with HLGR was 78%. In VSE strains, HLGR was found to be 42% and, HLSR 48%, the association of HLSR with HLGR was found to be 36%. HLAR in VRE strains was found to be higher as compared with VSE strains (p <0.005). Conclusion: Antimicrobial resistance is increasing in enterococci strains. Therefore a follow-up is required resistance pattern including both vancomycin resistance and HLAR.

Keywords

• Enterococcus spp.
• vancomycin
• linezolid
• aminoglycoside
• resistance

References

1. Sood S, Malhotra M, Das BK, Kapil A. Enterococcal infections & antimicrobial resistance. Indian J Med Res 2008;128:111-121.
2. Fisher K, Phillips C. The ecology, epidemiology and virulence of Enterococcus. Microbiology 2009;155:1749-1757.
3. Adhikari L. High-level aminoglycoside resistance and reduced sus- ceptibility to vancomycin in nosocomial enterococci. J Glob Infect Dis 2010;2:231-235.
4. Arias CA, Murray BE. Enterococcus species, Steptococcus bovis group, and Leuconostoc species. In: Mandell GL, Bennett JE, Dolin R, editors. Douglas and Bennett’s Principles and Practice of Infectious Disease 7th ed. Philadelphia, Churchill Livingstone; 2010:2643-2653.
5. Clinical and Laboratory Standards Institute Performance Stan- dards for Antimicrobial Susceptibility Testing. Seventeenth Infor- mational Supplement. M100-S17, 2007. CLSI, Wayne, PA.
6. Shouten MA, Hoogkamp-Korstanje JA, Meis JF, Voss A; European VRE Study Group. Prevalence of vancomycin-resistant entero- cocci in Europe. Eur J Clin Microbiol Infect Dis 2000;19:816-822.
7. Moaddab SR, Rafi A. Prevalence of vancomycin and high level aminoglycoside resistant enterococci among high-risk patients. Southeast Asian J Trop Med Public Health. 2003; 34:849-854.
8. Cuellar-Rodriguez J, Galindo-Fraga A, Guevara V, et al. Van- comycin-resistant enterococci, Mexico City. Emerg Infect Dis 2007;13:798-799.

9. Centers for Disease Control and Prevention. Recommendations for preventing spread of vancomycin resistance. Infect Control Hosp Epidemiol 1995;16:105-113.
10. Vural T, Sekercioglu AO, Ogunc D, et al. Vancomycin resistant Enterococcus casselifavus isolate. Ankem Derg 1998;12:113.
11. Yazgi H, Ertek M, Erol S, Ayyıldız A. A comparison of high-level aminoglycoside resistance in vancomycin-sensitive and van- comycin–resistant Enterococcus species. J Int Med Res 2002; 30:529-534.
12. Karagoz G, Kadanalı A, Ak O, Ozer S. Vancomycin-resistant en- terococci rectal colonization in an intensive care unit. A report from Turkey. Am J Infect Control 2012;40:83-84.
13. Cicekler-Tok N, Ozturk Engin D, Tok B, et al. Vancomycin-resis- tant enterococci (VRE) scan in rectal swab samples of a patient admitted to the department of Anesthesiology and Reanimation. The Medical Journal of Haydarpasa Numune Training and Re- search Hospital 2007;48:38-41.
14. Kacmaz B, Aksoy A. Antimicrobial resistance of enterococci in Turkey. Int J Antimicrob Agents 2005; 25:535-538.
15. Oncu S, Punar M, Eraksoy H. Susceptibility patterns of entero- cocci causing infections. Tohoku J Exp Med 2004; 202:23-29.
16. Mendiratta DK, Kaur H, Deotale V, et al. Status of high level ami- noglycoside resistant Enterococcus faecium and Enterococcus feacalis in a rural hospital of Central India. Indian J Med Microbiol 2008;26:369-371.
17. Mihajlovic Ukropina M, Jelesic Z, Gusman V, Milosavljevic B. Fre- quency of vancomycin-resistant enterococci isolated from blood cultures from 2008 to 2010. Med Pregl 2011;64:481-485.
18. Yildirim M, Sencan I, Ozdemir D, et al. Investigation of vancomy- cin and high-level aminoglycoside resistant enterococus carriage and the risk factors related to resistance in hospitalized patients. Mikrobiol Bult 2007;41:271-277.
19. Arias CA, Contreras GA, Murray BE. Management of multi- drug-resistant enterococcal infections. Clin Microbiol Infect 2010;16:555-562.