ANAEROBIC BACTERIA ISOLATED FROM CLINICAL SPECIMENS IN A UNIVERSITY HOSPITAL AND RESISTANCE OF ANAEROBIC GRAM-NEGATIVE RODS TO ANTIBIOTICS

Year 2020, Volume: 83 Issue: 4, 397 - 406, 19.10.2020

Lütfiye Öksüz

Abstract

Objective: Although anaerobic bacteria are normal microbiota members in humans, they can cause endogenous and exogenous infections. The empirical treatment of anaerobic infections is based on reports of susceptibility patterns reported in various studies. This study aims to identify the anaerobic bacteria isolated from clinical samples in 2018 and to determine the resistance of anaerobic Gram-negative rods to antibiotics and to compare the results obtained with the results of anaerobic Gram-negative rods isolated between 2015 and 2017 in the same unit in this study. Material and Method: Specimens were inoculated on Schaedler Agar and Cooked Meat Broth and incubated in anaerobic conditions. Bacteria were identified by colony morphologies, conventional tests and anaerobic diagnostic discs. Antibiotic susceptibility tests were performed using the concentration gradient method and evaluated according to the criteria of CLSI. Results: Of the 1630 clinical samples sent for anaerobic culture, 41 (2.5%) anaerobic bacteria were isolated. Most of the bacteria were isolated from the Department of Gynecology and Obstetrics (29%), Otorhinolaryngology (29%) clinics and mostly abscess specimens (49%). Seventy-one percent of the isolated anaerobic bacteria were Gram-negative and 29% Gram-positive bacteria. The most frequently isolated anaerobic bacteria were Bacteroides fragilis group (24%) and Prevotella spp (22%). Clindamycin resistance was quite high and there was no carbapenem resistance in anaerobic Gram-negative rods, but one third of the isolates were resistant to amoxicillin+clavulanic acid. Conclusion: It was remarkable that more than half of the isolated anaerobic Gram-negative rods, especially the B. fragilis group, were resistant to clindamycin and about a third of amoxicillin+ clavulanate. Increased resistance to these antibiotics used empirically in the treatment of infections caused by anaerobic Gram-negative rods is anticipated to limit antibiotic treatment regimens in the future. Routine monitoring of resistance is necessary for proper empirical treatment.

Keywords

Anaerobic bacteria, antibiotic resistance, .

BİR ÜNİVERSİTE HASTANESİNDE KLİNİK ÖRNEKLERDEN İZOLE EDİLEN ANAEROP BAKTERİLER VE ANAEROP GRAM-NEGATİF ÇOMAKLARIN ANTİBİYOTİKLERE DİRENCİ

Abstract

Amaç: Anaerop bakteriler, insanda normal mikrobiyota üyesi olmakla birlikte endojen ve ekzojen enfeksiyonlara neden olabilmektedir. Anaerobik enfeksiyonların ampirik tedavisi, çeşitli araştırmalarda bildirilen duyarlılık paterni raporlarına dayanmaktadır. Bu çalışmada, 2018 yılında klinik örneklerden izole edilen anaerop bakterilerin tanımlanarak anaerop Gram-negatif çomakların antibiyotiklere direnç durumlarının belirlenmesi ve elde edilen sonuçların aynı birimde 2015-2017 yılları arasında izole edilen anaerop Gram-negatif çomaklara ait sonuçlarla karşılaştırılması amaçlanmıştır. Gereç ve Yöntem: Klinik örnekler Schaedler agar ve kıymalı buyyon besiyerlerine ekilerek anaerop ortam sağlayıcı ile birlikte anaerop ortamda inkübe edilmiştir. Bakteri tanımlaması koloni morfolojisi, konvansiyonel testler ve anaerop tanı diskleri ile yapılmıştır. Antibiyotik duyarlılık deneyleri, konsantrasyon gradiyent yöntemi kullanılarak gerçekleştirilmiş ve CLSI kriterlerine göre değerlendirilmiştir. Bulgular: Anaerop kültür için gönderilen 1630 klinik örnekten 41 (%2,5) anaerop bakteri izole edilmiştir. Anaerop bakteri izole edilen örneklerin en çok Kadın Hastalıkları ve Doğum Kliniği (%29) ve Kulak-Burun-Boğaz (%29) kliniklerinden ve en fazla abse (%49) örneklerinden izole edildiği belirlenmiştir. İzole edilen anaerop bakterilerin %71’inin Gram-negatif, %29’unun Gram-pozitif bakteriler olduğu, en sık izole edilen anaerop bakterilerin Bacteroides fragilis grubu (%24) ve Prevotella cinsi (%22) bakteriler olduğu bulunmuştur. Klindamisin direncinin oldukça yüksek olduğu, anaerop Gram-negatif çomaklarda karbapenem direncinin olmadığı, ancak suşların üçte birinin amoksisilin+klavulanik asite dirençli olduğu bulunmuştur. Sonuç: Özellikle B. fragilis grubunda olmak üzere, izole edilen anaerop Gram-negatif çomakların yarısından fazlasının klindamisine ve yaklaşık üçte birinin amoksisilin+klavulanata dirençli olması dikkat çekicidir. Ampirik olarak kullanılan antibiyotiklere karşı artan direncin, gelecekteki antibiyotik tedavi rejimlerini kısıtlayacağı tahmin edilmektedir. Uygun ampirik tedavi için direncin rutin olarak izlenmesi gereklidir.

Keywords

Anaerop bakteri, antibiyotik direnci

References

• 1. Baysallar M, Bedir O. Anaerobic Bacteriology. In: Garcia LS, Isenberg HD, editors. The Handbook of Clinical Microbiology Methoods (Translate eds: Başustaoğlu A, Yıldıran ŞT). ASM Press: Washington; 2014, s. 4.0.1.
• 2. Jousimies-Somer HR, Summanen P, Citron DM, Baron EJ, Wexler HM, Finegold SM, editors. Waddsworth-KTL Anaerobic Bacteriology Manual. Chapter 1: Introduction to Anaerobic Bacteriology. Star Publishing Company: California; 2002, p.1.
• 3. Tunçkanat F. Anaerobic bacteria: General characteristics. In: Topçu AW, Söyletir G, Doğanay M, editors. Infectious Diseases and Microbiology. Nobel Medical Bookstores: İstanbul; 2017, s.2036.
• 4. Cohen-Poradosu R, Kasper DL. Anaerobic Infections: General concepts. In: Bennett JE, Dolin R, Blaser MJ editors. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. Elseiver: USA; 2015, s.2736-43.
• 5. Yenen OŞ. Infections of anaerobic bacteria. In: Brooks GF, Carroll KC, Butel JS, Morse SA, Mietzner TA, editors. Jawetz, Melnick, Adelberg Medical Microbiology. Nobel Medical Bookstores: İstanbul; 2014, s.295.
• 6. Syndman Dr, Jacobus NV, Mc Dermott LA, Ruthazer R, Golan Y, Goldstein EJ, et al. National Survey on the Susceptibility of Bacteroides fragilis Group: Report and Analysis of Trends in the United States from 1997 to 2004. Antimicrob Agents Chemother 2007;51(5):1649-55. [CrossRef]
• 7. Liu CY, Huang YT, Liao CH, Yen LC, Lin HY, Hsueh PR. Increasing Trends in Antimicrobial Resistance among Clinically Important Anaerobes and Bacteroides fragilis Isolates Causing Nosocomial Infections: Emerging Resistance to Carbapenems. Antimicrob Agents Chemother 2008;52(9):3161-8. [CrossRef]
• 8. Procop GW, Church DL, Hall GS, William M. Janda WM, Koneman EW, Schreckenberger PC, Woods GL, editors. Koneman’s Color Atlas & Textbook of Diagnstic Microbiology. The anaerobic bacteria. Lipincott Williams & Wilkins: Philadelphia; 2017, p.983-1071.
• 9. Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. 27th ed. CLSI supplement M100, 2017. S-26.
• 10. Jousimies-Somer HR, Summanen P, Citron DM, Baron EJ, Wexler HM, Finegold SM, editors. Waddsworth-KTL Anaerobic Bacteriology Manual. Chapter 8. Susceptibility testing of anaerobic bacteria. Star Publishing Company: California; 2002, s.143.
• 11. Öksüz L, Gürler N. Resistance of anaerobic bacteria isolated from clinical specimens to antibiotics: A three-year surveillance. 33. Antimicrobial Chemothearpy Congress, Oral presentation, S130, 2-6 May 2018, Fethiye.
• 12. Dubreuil L, Odou MF. Anaerobic bacteria and antibiotics: What kind of unexpected resistance could I find in my laboratory tomorrow? Anaerobe 2010;16:555-9. [CrossRef]
• 13. Hecth DW. Anaerobes: Antibiotic resistance, clinical significance, and the role of susceptibility testing. Anaerobe 2006;12:115-21. [CrossRef]
• 14. Gajdacs M, Spengler G, Urban E. Identification and Antimicrobial Susceptibility Testing of Anaerobic Bacteria: Rubik’s Cube of Clinical Microbiology? Antibiotics 2017;6:1- 29. [CrossRef]
• 15. Gürler N. Anaerobic cocci. In: Topçu AW, Söyletir G, Doğanay M. Infectious Diseases and Microbiology. s. 2046. Nobel Medical Bookstores: İstanbul; 2017.
• 16. Könönen E, editor. Anaerobic cocci and anaerobic Grampositive nonsporulating bacilli. In: Bennett JE, Dolin R, Blaser MJ. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. Elseiver: USA; 2015, s.2781-6.
• 17. Murray PR, Rosenthal KS, Pfaller MA, editors. Medical Microbiology. Philadephia; 2009, s.399-404.
• 18. Bahar H, Mamal Torun M, Demirci M, Sever N, İstanbullu A. Anaerobic bacteria isolated from clinical specimens of pediatric patients and resistance to antibiotics. ANKEM Derg 2002;16(4):486-91.
• 19. Bahar H, Mamal Torun M, Demirci M, Kocazeybek B. Antimicrobial resistance and beta lactam production of clinical isolates of Prevotella and Porphyromonas species. Chemotherapy 2005;51:9-14. [CrossRef]
• 20. Kiremitçi A, Türkkan AA, Akgün Y, Durmaz G, Kaşifoğlu N. Isolation of anaerobic bacteria from clinical samples and determination of antibiotic susceptibility. Bulletin of ANKEM 2008;22(3):132-44.
• 21. Ülger Toprak N, Uzunkaya ÖD, Soki J, Söyletir G. Susceptibility profiles and resistance genes for carbapenems (cfiA) and metronidazole (nim) among Bacteroides species in a Turkish University Hospital. Anaerobe 2012;18:169-71. [CrossRef]
• 22. Ulger Toprak N, Veloo ACM, Urban E, et al. A multicenter survey of antimicrobial susceptibility of Prevotella species as determined by E test methodology. Anaerobe 2018;52:9- 15. [CrossRef]
• 23. Keşli R, Demir C. Identification of Anaerobic Gram- Negative Bacilli Isolated from Various Clinical Specimens and Determination of Antibiotic Resistance Profiles with E-Test Methods. Mikrobiyol Bul 2018;52(1):72-9. [CrossRef]
• 24. Galvao BPGV, Meggersee RL, Abratt VR. Antibiotic resistance and adhesion potential of Bacteroides fragilis clinical isolates from Cape Town, South Africa. Anaerobe 2011;17:142-6. [CrossRef]
• 25. Syndman DR, Jacobus NV, Mc Dermott LA, Golan Y, Goldstein EJ, Harrel L, et al. Update on resistance of Bacteroides fragilis group and related species with special attention to carbapenems 2006-2009. Anaerobe 2011;17:147-51.
• 26. Ülger Toprak N, Çelik C, Çakıcı Ö, Söyletir G. Antimicrobial susceptibilities of Bacteroides fragilis and Bacteroides thetaiotamicron strains isolated from clinical specimens and human intestinal microbiota. Anaerobe 2004;10(5):255- 9. [CrossRef]
• 27. Gürler N, Zandi H, Töreci K. Comparison of agar dilution, E test and broth disc elution methods in determining the susceptibility of anaerobic bacteria. Bulletin of ANKEM 1997;11(4):487-92.
• 28. Tunçkanat F. Susceptibility tests of anaerobic bacteria and resistance status. Alıntılama tarihi: 09.07.2018. Available from: http://www.tmc-online.org/userfiles/file/AKG_ Sunumlar/22nisan/ferda_tunckanat_anaerop_bakterilerin_ duyarlilik_testleri.pdf.
• 29. Garrett WS, Onderdonk AB. Bacteroides, Prevotella, Porphyromonas, and Fusobacterium Species (and Other Medically Important Anaerobic Gram-Negative Bacilli). In: Bennett JE, Dolin R, Blaser MJ, editors. Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases. Elseiver: USA; 2015, s.2773-80.
• 30. Syndman DR, Jacobus NV, McDermott LA, Golan Y, Hecht DW, Goldstein EJ, et al. Lessons Learned from the Anaerobe Survey: Historical Perspective and Review of the Most Recent Data (2005-2007) Clin Infect Dis 2010;50(Suppl 1):S26-33. [CrossRef]
• 31. Yamazoe K, Kato N, Kato H, et al. Distribution of the cfiA Gene among Bacteroides fragilis Strains in Japan and Relatedness of cfiA to Imipenem Resistance. Antimicrob Agent Chemother 1999;43(11):2808-10. [CrossRef]
• 32. Ülger Toprak N. Susceptibility tests and data Turkey: Anaerobes. Gülhane Microbiology Days, Antimicrobial Chemotherapy Laboratory Applications and Innovations. 20-22 Nisan 2010, İstanbul.
• 33. Byun BH, Kim M, Lee Y, Lee K, Chong Y. Antibiotic susceptibility patterns of anaerobic bacterial clinical isolates from 2014-2016, including recently named or renamed species. Ann Lab Med 2019;36:190-9. [CrossRef]
• 34. Nagy E, Urban E, Nord CE. Antimicrobial susceptibility of Bacteroides fragilis group isolates in Europe: 20 years of experience. Clin Microb Infect 2011;17:371-9. [CrossRef]
• 35. Bouchillon S, Renteria M, Hackel M, Johnson B, Dowzicky M. Gram-negative anaerobe susceptibility rates in six European countries, 2007-2009. 20th ECCMID Congress, P1293, Vienna, 10-13 April 2010.
• 36. Rodloff AC, Dowzicky MJ. In vitro activity of tigecycline and comparators against a European collection of anaerobes collected as part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) 2010-2016. Anaerobe 2018;51:78- 88. [CrossRef]
• 37. Wüst J, Hardegger U. Comparison of the E test and a reference agar dilution method for susceptibility testing of anaerobic bacteria. Eur J Clin Microbiol Infect Dis 1992;11(12):1169-73. [CrossRef]
• 38. Biomerieux, E test application guide. 2012/07. Available from: https://www.biomerieux-usa.com/sites/subsidiary_ us/files/supplementary_inserts_-_16273_-_b_-_en_-_ eag_-_etest_application_guide-3.pdf Alıntılama tarihi: 15.05.2020.