Anatol J Clin Investig 2012;6(1):238-241
HELICOBACTER PYLORI ISOLATES RECOVERED FROM ANTRAL GASTRIC BIOPSIES OF PATIENTS WITH DYSPEPTIC SYMPTOMS: ANTIMICROBIAL RESISTANCE OF METRONIDAZOLE, CLARITHROMYCIN AND AMOXICILLIN DİSPEPTİK YAKINMALARI OLAN HASTALARIN ANTRAL GASTRİK BİYOPSİLERİNDEN İZOLE EDİLEN HELİCOBACTER PYLORİ SUŞLARININ METRANİDAZOL, KLARİTROMİSİN VE AMOKSİSİLİNE DİRENCİ
Fatma Kalem1, Mehmet Özdemir2, Metin Başaranoğlu3, Hatice Toy4, Bülent Baysal1 1
Konya Numune Hastanesi, Mikrobiyoloji Laboratuvarı, Konya. Selçuk Üniversitesi, Meram Tıp Fakültesi, Tıbbi Mikrobiyoloji AD., Konya. 3 Selçuk Üniversitesi, Meram Tıp Fakültesi İç Hastalıkları AD, Gastroenteroloji Bilim Dalı., Konya. 4 Selçuk Üniversitesi Meram Tıp Fakültesi Tıbbi patoloji AD., Konya. 2
Abstract Drug resistance in Helicobacter pylori infection is increasing worldwide. This is the main cause of failure of eradication therapy. The aim of this study was to determine in vitro resistance of commonly used antibiotics in H. pylori strains isolated from city of Konya in Turkey. 103 patients with dyspeptic symptoms were included in this study. Upper gastrointestinal endoscopy was performed in each patient. Biopsy specimens obtained were cultured on selective medium Pylori agar. The MIC for amoxicillin, clarithromycin, and metronidazole were determined by the Epsilometer test on Mueller-Hinton 7% sheep blood agar plates. Of the 103 specimens, 40 (38.8%) were positive for culture. Of the 40 strains, 28 were tested for in vitro antibiotic susceptibility of metronidazole, clarithromycin and amoxicillin by E-test method. All strains were susceptible to amoxicillin. Resistance to clarithromycin and metronidazole were detected in 8 (28.5%) and 11 (39.2%) isolates, respectively. As resistance patterns in H. pylori isolates differ according to the geographical variation by time, it should be monitored locally for current recommending treatment regimen in every year. It was considered that performing culture and sensitivity testing of H. pylori resistance for prospective surveillance should be useful. (Anatol J Clin Investig 2012;6(1):238-241). Key Words: H. pylori, resistance, culture, amoxicillin, clarithromycin, metronidazole Özet Helicobacter pylori infeksiyonu tedavisinde kullanılan ilaçlara karşı direnç dünya çapında artmaktadır. Eradikasyon tedavisindeki başarısızlığın ana nedeni budur. Bu çalışmanın amacı, Konya ilinde izole edilen H.pylori suşlarında tedavide sık kullanılan antibiyotiklere karşı in vitro direnci tespit etmektir. Çalışmaya dispeptik semptomları olan 103 hasta dahil edildi. Her hastaya üst gastrointestinal sistem endoskopisi uygulandı. Alınan biyopsi örneklerinden seçici besiyeri Pylori agara sürüntü şeklinde ekim yapıldı Amoksisilin, klaritromisin ve metronidazol için MIC değerleri Mueller-Hinton % 7 koyun kanlı agar plaklarında Epsilometer testi ile araştırıldı. 103 örneğin 40’ında(% 38.8), kültürde üreme tespit edildi. 40 suştan 28’inde E-test yöntemi ile metronidazol, klaritromisin ve amoksisiline karşı duyarlılık test edildi. Tüm suşlar amoksisiline duyarlı bulundu. Klaritromisin ve metronidazole karşı direnç sırasıyla 8 (% 28.5) ve 11 (% 39.2) izolatta tespit edildi. H.pylori izolatları direnç paternleri coğrafi varyasyona göre ve zamanla değiştiğinden dolayı güncel tedavi rejimindeki direnç bölgesel olarak her yıl izlenmelidir. Prospektif sürveyans çalışmalarında H.pylori direnç profilini saptamak amaçlı kültür ve duyarlılık testi yapılmasının yararlı olacağı kanaatine varılmıştır. (Anatol J Clin Investig 2012;6(1):238-241). Anahtar Sözcükler: H.pilori, rezistans, kültür, amoksisilin, klaritromisin, metronidazol
Introduction Helicobacter pylori (H.pylori) is a common pathogen in the human stomach which causes gastritis, gastric and duodenal ulcer and several lymphomas. H. pylori is also strongly associated with gastric malignancies [1,2]. It has been classified as a class I carcinogen in the stomach according to the World Health Organization (WHO) [3,4]. In developing countries; the prevalence of H. pylori infection is approximately
70-90% (4). If H. pylori is isolated in patients with peptic ulcer disease, this infection must be treated with appropriate antibacterial therapy because eradication of the bacteria prevents gastric diseases and relapses. However, it is still not clear that how these resistant organisms spread and cause treatment failure [4,5]. Treatment for H. pylori infection is often started empirically. If the infecting strain is resistant, the
Fatma Kalem Konya Numune Hastanesi, Mikrobiyoloji Laboratuvarı E-mail:
[email protected] Makalenin gönderilme tarihi:14.07.2011 Makalenin kabul edilme tarihi: 24.10.2011
Helicobacter Pylori and antimicrobial resistance of Metronidazole, Clarithromycin And Amoxicillin
success of eradication decreases sharply [6]. In Turkey, the recommended current triple-drug therapy for H. pylori eradication includes a proton pump inhibitor (PPI) and amoxicillin and clarithromycin or metronidazole combination. The prevalence of clarithromycin, metronidazole and amoxicillin resistance differs worldwide. The prevalence of clarithromycin-resistant H. pylori isolates is increasing by time too [5,7]. The rate of resistance is higher in developing countries than developed countries [8]. Therefore, it is particularly important to know antibiotic resistance pattern of local H. pylori strains particularly for developing countries, such as Turkey. The purpose of this study was to investigate in vitro susceptibility of H. pylori isolated from patients with symptoms of dyspepsia undergone upper gastrointestinal endoscopy. Material and Methods Between January 2006 and December 2009, 103 patients were included in this study. All patients undergone upper gastrointestinal endoscopic evaluation for dyspeptic symptoms at the endoscopy unit of Gastroenterology Department of Meram Medical Faculty. Antral gastric biopsy specimens were obtained, and sent to the laboratory in sterile saline solutions within an hour. The biopsy specimens were cultured on selective medium “Pylori agar (bioMerieuxFrance)”. Patients who had records of taking antimicrobials, H2 blockers, PPIs or bismuth subsalicylate within 4 weeks prior to endoscopic examination were excluded from the study. This study was approved by the Ethics Committee of the Selcuk University Meram Medical Faculty and informed content was obtained from each patient. Isolates were identified as H. pylori based on colony morphology, negative Gram staining, positive biochemical reactions for urease, catalase, and oxidase. H. pylori NCTC 11637 was used as the control strain. The minimum inhibitory concentration (MIC) for amoxicillin, clarithromycin, and metronidazole were determined by the Epsilometer test (E-test; AB Biodisk, Sweden) on Mueller-Hinton 7% sheep blood agar plates (GBL–Gul BiologyTurkey). Inocula were prepared from fresh growth. Suspensions of inoculum which have a turbidity equivalent to 2 McFarland standard were swabbed all over agar plates and E-test strips that were placed on to the surface. Plates containing E-test strips were incubated for 72 hour under microaerophilic conditions. GENbag (bioMerieux-France) was used for providing microaerophilic conditions. The MIC was defined by the point of intersection of the inhibitory zone with the strip (8). In the E-test, the break-points of resistance for amoxicillin, clarithromycin and
metronidazole were accepted as ≥1.0, ≥1.0 and ≥8.0 respectively [9]. Results Sixty males and 43 female patients were included in this study. The mean age of patients undergone upper gastrointestinal endoscopic evaluation was 502+4.1 years old. Of the 103 antral biopsy specimens cultured, H. pylori was isolated from 40 (38.8%) specimens in the cultures. Susceptibility to amoxicillin, clarithromycin and metronidazole were detected in 28 of the isolates. All strains were susceptible to amoxicillin by E-test. Resistance to clarithromycin and metronidazole were found 28.5% and 39.2%, respectively (Table 1). Discussion H. pylori is transmitted by fecal-oral route such as exposure to contaminated food and water. Additionally, it is believed that one of the main transmission routes is within family members [10]. Antimicrobial resistance is an important problem in the treatment of H. pylori infections. The use of antibiotics for treatment of other infections like gynecologic, parasitic or upper respiratory infections seems to be the major risk factor for the development of resistance [11]. Antimicrobial resistance in clinical H. pylori isolates is extensive, especially in high-risk populations. Because of H. pylori resistance patterns vary according to the geographical variation, each country must provide local data to make the recommendation for the most effective therapy. Testing the antimicrobial susceptibility of H. pylori is important because acquired resistance to various drugs can decrease the efficacy of the treatment of gastric infections. If treatment is inefficient due to the antimicrobial resistance, continued symptoms lead to increased morbidity and prolonged suffering from the disease and further diagnostic tests for H. pylori [7]. Moreover, persistent inflammation may lead to gastric cancer [6,12]. In this study, we evaluated antimicrobial susceptibility of amoxicillin, clarithromycin and metronidazole. Despite a wide use, resistance rate of amoxicillin in H. pylori isolates is generally low. Studies from Northeast Italy, France, Sweden, The Netherlands and our presented study reported that all H. pylori strains were amoxicillin susceptible [9,11,13,14]. A multicenter study showed amoxicillin resistance rate as 0.9% [15] in the USA. Indian population studies showed a considerable difference between the rates of amoxicillin resistance of H. pylori from 32.8% to 4% [7,16]. To the best of our knowledge,
239
Anatol J Clin Investig 2012;6(1):238-241
KALEM F.
resistance to amoxicillin has not been reported in Turkey so far [17,18]. Clarithromycin is one of the most commonly used drug in the therapy of H. pylori infection. Resistance to H. pylori is usually due to A2142G and A2143G transition mutations in the 23S r RNA gene. Thus, the affinity of clarithromycin binding to ribosome decreases. It is well-known that particularly H. pylori strains become resistant to clarithromycin if they are given to the patients in the past at sub-MIC levels [19]. Kobayashi et al detected clarithromycin resistance at a high frequency after eradication therapy with clarithromycin [19]. Clarithromycin resistance is the main cause of treatment failure and this resistance is increasing [5]. Treatment should achieve an eradication rate of >80%. The threshold of clarithromycin resistance at which this antibiotic should not be used without clarithromycin susceptibility test is 15–20% [20]. The rate of clarithromycin resistance seems to be population dependent [11]. Previous studies from Taiwan, Northeast Italy, United States, France and India reported the rate of clarithromycin resistance as 13.5%, %1.8, 12.9%, 22.8%, and 44.7%, respectively [8,9,15,11,16]. The prevalence of resistance patterns to H.pylori differs according to the geographical region and population. Tolia et al have reported the antimicrobial susceptibility rate as 59% in the USA [12]. Three different studies from Turkey reported the rate of clarithromycin resistance as 54.5%, 18.2%, and 20.5% by using the E-test method [17,21,22]. A recent study from Turkey reported that clarithromycin resistance increased from 16.7% to 37.5 % in Turkish population since 2001 [23]. In our study; it was found that 8 (28.5%) strains were resistant to clarithromycin by E-test. Metronidazole is a frequently used antibacterial agent for intestinal and gynecological problems, besides in general medical practice. This drug shows a higher resistance patterns. Chi-Tan Hu et al [8] from Taiwan and Mishra [7] and Thyagarajan et al [16] from India reported resistance rates to metronidazole in H. pylori strains as follows, 51.9%, 64% and 77.9%, respectively. A higher resistance rate with 80%
was reported from Mexico [24]. A multicenter study from the USA showed metronidazole resistance as 25.1% [15]. This relatively low resistance rate from the USA may be due to a restrictive antibiotic consumption in the USA compared to other countries. It is well-known that the prevalence of resistance is higher in developing countries than developed countries [25,26]. In Turkey, previous studies reported the rate of metronidazole resistance as 36.4% and 49% (17,18). In our current study; the resistance of H. pylori isolates was 11 (39.2% and this rate was between these two studies. In vitro resistance to metronidazole may not accurately reflect in vivo resistance. For this reason metronidazole testing is not recommended routinely in clinical practice [20]. Culture is a gold standard for detection of H. pylori, and has a high specificity. After the identification of the pathogen by culture, susceptibility to antibiotics may be possible to detect. Culture and antimicrobial susceptibility before treatment are not performed routinely in general practice because of invasive and very expensive procedures [12]. If antibiotic therapy is performed according to the results of antimicrobial susceptibility pattern, the success of H. pylori eradication treatment will be increased [5]. However, the prevalence of antibiotic resistance for H. pylori is also increasing [15]. Sensitivity of culture is lower than the other diagnostic tests and performing this test needs a long-time. In conclusion, resistance patterns in H. pylori isolates differ according to the geographical region and during the time. So resistance patterns should be monitored locally for current treatment regimen especially in the case of increasing resistance to clarithromycin in every year. Also in the failure of empirical antibiotic treatment, culture and sensitivity testing of H. pylori should be done. Acknowledgement The authors gratefully thank to Prof Dr Yakut Akyon from Hacettepe University, Department of Clinical Microbiology for support and validation of the Helicobacter pylori strains for this study.
Table 1. Resistance determined for 28 H. pylori isolates using the E-test Antimicrobial agent
Number of resistant strains
Resistance (%)
Amoxicillin
0
0
Clarithromycin
8
28.5
240
Helicobacter Pylori and antimicrobial resistance of Metronidazole, Clarithromycin And Amoxicillin
Metronidazole
11
39.2
References 1. 2. 3. 4. 5. 6.
7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
17. 18. 19. 20. 21. 22. 23. 24. 25. 26.
Sharara A, Chedid M, Araj G et al. Prevalence of Helicobacter pylori resistance to metronidazole, clarithromycin, amoxycillin and tetracycline in Lebanon. Int J Antimicrob Agents 2002;19:155–8. Ndip R, MacKay W, Farthing M, Weaver L. Culturing Helicobacter pylori from Clinical Specimens: Review of Microbiologic Method. J Pediatr Gastroenterol Nutr 2003;36:616–22. Ricci C, Holton J, Vaira D. Diagnosis of Helicobacter pylori: Invasive and non-invasive tests. Best Pract Res Clin Gastroenterol 2007;21:299-313. Baglan P, Bozdayi G, Ozkan M, et al. Clarithromycin Resistance Prevalence and Icea Gene Status in Helicobacter pylori Clinical Isolates in Turkish Patients with Duodenal Ulcer and Functional Dyspepsia. J Microbiol 2006;8:409-16. Lee J, Shin J, Roe I et al. Impact of Clarithromycin Resistance on Eradication of Helicobacter pylori in Infected Adults. Antimicrob Agents Chemother 2005;49;1600-3. Boyanovaa L, Gergovaa G Nikolovb R, et al. Prevalence and evolution of Helicobacter pylori resistance to 6 antibacterial agents over 12 years and correlation between susceptibility testing methods. Diagn Microbiol Infect Dis 2008;60:409-15. Mishra K, Srivastava S, Garg A, Ayyagari A. Antibiotic Susceptibility of Helicobacter pylori Clinical Isolates: Comparative Evaluation of Disk-Diffusion and E-Test Methods. Curr Microbiol. 2006; 53: 329–34. Hu C, Wu C, Lin C et al. Resistance rate to antibiotics of Helicobacter pylori isolates in eastern Taiwan J Gastroenterol Hepatol 2007;22:720-3. Pilotto A, Rassul M, Leandro G et al. Prevalence of Helicobacter pylori resistance to antibiotics in Northeast Italy: a multicentre study. Dig Liver Dis 2000;32:763-8. Malaty H. Epidemiology of Helicobacter pylori infection. Best Pract Res Clin Gastroenterol 2007;21: 205-14. Kalacha N, Serhala L, Asmara E et al. Helicobacter pylori primary resistant strains over 11 years in French children. Diagn Microbiol Infect Dis 2007;59:217–22. Tolia V, Brown W, El-Baba M et al. Helicobacter pylori culture and antimicrobial susceptibility from pediatric patients in Michigan. Pediatr Infect Dis J 2000;19:1167–71. Storskrubb T, Aro P, Ronkainen J et al. Antimicrobial Susceptibility of Helicobacter pylori strains in a random Adult Swedish Population. Helicobacter 2006;11:224-30. Debets-Ossenkopp Y, Herscheid A, Pot R et al. Prevalence of Helicobacter pylori resistance to metronidazole, clarithromycin, amoxycillin, tetracycline and trovafloxacin in The Netherlands. J Antimicrob Chemother 1999;43:511-5. Duck W, Sobel J, Pruckler J et al. Antimicrobial Resistance Incidence and Risk Factors among Helicobacter pylori– Infected Persons, United States. Emerg Infect Dis 2004;10:1088-94. Thyagarajan SP, Ray P, Das B et al. Resistant Helicobacter pylori Geographical Difference in antimicrobial resistance pattern of Helicobacter pylori clinical isolates from Indian patients: Multicentric study. J Gastroenterol Hepatol 2003;18:1373-8. Ozçay F, Koçak N, Temizel IN et al. Helicobacter pylori infection in Turkish children: comparison of diagnostic tests, evaluation of eradication rate, and changes in symptoms after eradication. Helicobacter 2004;9:242-8. Kantarçeken B, Yıldırım B, Karıncaoğlu M et al. Helicobacter pylori and antibiotic resistance. Turk J Gastroenterol 2000;11:141-5. Kobayashi I, Saika T, Muraoka H et al. Helicobacter pylori isolated from patients who later failed H. pylori eradication triple therapy readily develop resistance to clarithromycin. J Med Microbiol 2006;55:737–40. Malfertheiner P, Megraud F, O'Morain C et al. Current concepts in the management of Helicobacter pylori infection The Maastricht III Consensus Report. Gut 2007;56:772-81. Bağlan P, Bozdayı G, Özkan M, Özden A. Comparison of E-test ve Agar dilution methods in detection of Claritromycine resistant Helicobacter pylori. Academic Gastroenterology Derg 2005;4:83-7. Can F, Demirbilek M, Selçuk H, et al. Clarithromycin resistance of Helicobacter pylori strains isolated from antral biopsy samples. Mikrobiyol Bul 2004;38:349-53. Şimşek H, Balaban Y, Güneş D. Alarming Clarithromycin resistance of Helicobacter pylori in Turkish population. Helicobacter 2005;10(4):360-1. Torres J, Camorlinga-Ponce M, Pe´Rez-Pe´Rez G, et al. Increasing Multidrug Resistance in Helicobacter pylori Strains Isolated from Children and Adults in Mexico. J Clin Microbiol 2001;39:2677–80. Lang L, García F. Comparison of E-test and disk diffusion assay to evaluate resistance of Helicobacter pylori isolates to amoxicillin, clarithromycin, metronidazole and tetracycline in Costa Rica. Int J Antimicrob Agents 2004;24:572–7. Jenks P, Edwards D. Metronidazole resistance in Helicobacter pylori. Int J Antimicrob Agents 2002;19:1–7.
241
