PATTERNS OF HELICOBACTER PYLORI ISOLATE RESISTANCE TO FLUOROQUINOLONES, AMOXICILLIN, CLARITHROMYCIN AND METRONIDAZOLES

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PATTERNS OF HELICOBACTER PYLORI ISOLATE RESISTANCE TO FLUOROQUINOLONES, AMOXICILLIN, CLARITHROMYCIN AND METRONIDAZOLES Widyasari Kumala 1 and Aziz Rani 2 1 Department of Microbiology, Faculty of Medicine, Trisakti University, Jakarta; 2 Division of Gastroenterology, Department of Internal Medicine, Faculty of Medicine, Indonesia University and Dr Cipto Mangunkusumo General National Hospital, Jakarta, Indonesia Abstract. Helicobacter pylori eradication using the three antibiotic regimen of amoxicillin, clarithromycin and metronidazole often fails, making it imperative to find substitutes. The following study made use of 72 H. pylori isolates derived from pyloric antrum mucosa biopsies of gastritis and chronic dyspepsia patients treated at the Cipto Mangunkusumo National General Hospital and three private hospitals in Jakarta. Testing for H. pylori sensitivity to various antimicrobials was conducted using the disk diffusion method (Kirby Bauer) and procedures determined by the Clinical and Laboratory Standards Intitute (CLSI)/NCCLS. The resistance rates of the isolates were 100% for metronodazole, 27.8% for clarithromycin, 19.4% for amoxicillin, 6.9% for ciprofloxacin, norfloxacin and ofloxacin, 2.8% for sparfloxacin and gatifloxacin, and 1.4% for levofloxacin and moxifloxacin. Fluoroquinolons have the lowest resistance compared to amoxicillin, clarithromycin and metronidazole. INTRODUCTION Warren and Marshall discovered in 1983 that Helicobacter pylori plays a major role in active chronic gastritis, stomach ulcers, duodenum ulcers and gastric carcinoma (Blaser et al, 1995; Lee, 1996; Marshall, 1996; Kupier, 1999). Prevalence of H. pylori infection is considerably higher in developing countries, such as Indonesia (Ketut, 1995). Infection is associated with geographical, socioeconomic and environmental sanitation factors (Rourke et al, 2003). H. pylori infection is prevalent in nearly 95% of those with duodenal ulcers and in 80% and 90% of those with gastric ulcers (Mitchell, 1999). Correspondence: Widyasari Kumala, Department of Microbiology, Faculty of Medicine, Trisakti University, Kyai Tapa, no 260 (Kampus B) Grogol, 11440, Jakarta, Indonesia. Tel: 62 215482808; Fax: 62 215325775 During the initial stage of infection, the disease generally proceeds without symptoms. Patients come to know they are infected with H. pylori when the infection is chronic, producing ulcers or cancer. Treatment of H. pylori is important in the prevention of ulcers and gastric carcinoma. To date there have been frequent relapses. Resistance to amoxicillin, clarithromycin and metronidazole, three antibiotics currently employed to eradicate the bacteria, has been on the increase in a number of countries (Megraud, 2004). There is an urgent need to find other antibiotics, such as the fluoroquinolone group, to combat H. pylori. MATERIALS AND METHODS Study samples were gastric antrum biopsies. Biopsies was taken by endoscopy in 126 patients suffering from chronic gastritis and dyspepsia. There were 67 males, age 25 970 Vol 37 No. 5 September 2006

PATTERNS OF H. PYLORI RESISTANCE TO SOME ANTIBIOTICS to 65 years (average 30), and 59 females age 22 to 65 years (average 28) treated as out patients at Cipto Mangunkusumo National General Hospital and three private hospitals in Jakarta. Biopsies were taken after informed consent was given. The gastric biopsy samples were placed in Stuart transport medium, stored in a cold thermos flask (using ice), then immediately transported to the microbiology laboratory, Faculty of Medicine, Trisakti University. Isolation and identification Isolation for H. pylori was conducted at the Microbiology Department, Faculty of Medicine, Trisakti University, by placing the finely cut biopsy tissues in Brucella blood agar (Brucella agar containing 5% sheep blood and 0.2% vitamin K) and Dent selective medium (Brucella agar with 5% sheep blood and Dent supplement from Oxoid). They were incubated at 37ºC for 3 to 5 days in a humid place with 5% oxygen and 10% carbon dioxide. Incubation was done using an anaerobic jar containing Campylobacter BR 56 and BR 46 catalyst from Oxoid. By 3 to 5 days, if fine, translucent colonies were seen in the Brucella agar medium and greyish colonies in the Dent medium, then these colonies were assumed to be H. pylori. The colonies were then microscopically identified and biochemically tested. Bacteria samples were subjected to Gram staining. Gram-negative bacteria and in spirals with two S or U curves, are most probably H. pylori. Biochemical testing was made with a rapid urease test using motility indole urease (MIU) (Kumala et al, 2001), catalase, and oxydase. All tested isolates were put in tryptic soy broth with 10% glycerol as stock before being stored at -70ºC. The isolates were stored at this temperature until antibiotic sensitivity was testing. Antibiotic sensitivity testing The disk diffusion method was performed according to Kirby Bauer method H. pylori colonies were suspended in Brain Heart Infusion broth to MacFarland 2 turbidity standard. The solution (0.1 ml) was then spread evenly on Brucella blood agar. Antibiotic disks for ciprofloxacin, gatifloxsacin, moxifloxasin, levofloxasin, norflosxacin, ofloxacin, amoxicillin, clarithromycin and metronidazole were placed on the Brucella blood agar. Each agar culture plate had three kinds of antibiotics tested and was processed duplo-wise. H. pylori ATCC 43504 served as a quality control unit. The plate was subsequently incubated similar to the H. pylori isolation method. The inhibition zone diameter was measured in millimeters. Sensitivity of H. pylori to an antibiotic was in accordance with the Clinical and Laboratory Standards Institute (CLSI/NCCLS, 2005). RESULTS Of the 126 samples, 2 were excluded due to contamination with Candida sp. Seventytwo (56.1%) were isolated and tested for antibiotic sensitivities (Table 1). The total H. pylori Table 1 Resistance pattern of H. pylori to fluoroquinolones, amoxicillin, clarithromycin and metronidazole. Antibiotics Total of resistant isolates n (%) Metronidazole (5 µg) 72 (100) Clarithromycin (15 µg) 20 (27.8) Amoxicillin (20 µg) 14 (19.4) Ciprofloxacin (5 µg) 5 (6.9) Norfloxacin (10 µg) 5 (6.9) Ofloxacin ( 5 µg) 5 (6.9) Sparfloxacin ( 5 µg) 2 (2.8) Gatifloxacin ( 5 µg) 2 (2.8) Moxifloxacin ( 5 µg) 1 (1.4) Levofloxacin ( 5 µg) 1 (1.4) Total number of isolates = 72; n = number of total of resistant isolates Vol 37 No. 5 September 2006 971

isolates resistant to metronidazole were 72 (100%), clarithromycin 20 (27.8%), and amoxicillin 14 (19,4%). The resistance to other antibiotics was as follows: fluoroquinolone ciprofloxacin, norfloxacin and ofloxacin 5 (6.9%), and sparfloxacin and gatifloxacin 2 (2.8%). Only one H. pylori isolate (1.4%) was resistant to levofloxacin and moxifloxacin. DISCUSSION H. pylori was totally resistant to metronidazole. The data are consistent with earlier research conducted in several areas of Indonesia, such as Malang (Achmad, 1996) and Bali (Suate and Suyasa, 1995). Central Africa has reported 70-90% resistance (Walt, 1996) and Costa Rica 95.1% (Quintana- Guzman et al, 1998). This may be due to frequent use of metronidazole in the treatment of diarrhea caused by ameba, trichomoniasis in women and other anaerobic bacterial infections when incorrect observing dosing and duration of medication are used (Jenks et al 1999). Another cause is gene mutation. Mutation of the rdxa gene accelerates H. pylori resistance to metronidazole (Kwon et al, 2000; Paul et al, 2001). Other studies regarding amoxicillin and clarithromycin have also revealed resistance. H. pylori resistance to various antibiotics has been found in a number of countries (Wu et al, 2000; Torres et al, 2001; Megraud, 2004). Resistance to clarithromycin was found in 27.8%. This is because clarithromycin is frequently used in the treatment of upper and lower respiratory tract infections in children and adults (Loivukene et al, 2002; Perez et al, 2002). Another factor contributing to resistance is mutation of the H. pylori 235 rrna gene, and A2143G (Matsumura et al, 2001; Francesco et al, 2006). H. pylori sensitivity to amoxicillin is still acceptable, although 19.4% resistance cannot be ignored. Frequent use of this antibiotic for the treatment of respiratory and skin infections in our country may contribute to bacterial resistance. A study by Achmad in 1996 found H. pylori resistance to amoxicillin to be present in more than 90%. The difference in results from this study may be attributed to different bacterial strains in different regions (Achmad, 1996; Thyagarajan et al, 2003), the density of different inoculums (Berger et al, 1993), medium and incubation time (Hartzen et al, 1997). Paul et al in 2001 proved that H. pylori pbpl gene mutation makes it resistant to amoxicillin. Resistance to ciprofloxacin in a current study (6.9%) is consistent with the literature which found resistance to ciprofloxacin is still low at 5-15% (Zeiler and Grohe, 1984). Similar results have been seen in studies carried out in France and Eastern European countries where resistance rates were 3.8% and 3.9%, respectively (Birac et al, 1999; Boyanova et al, 2002). Our study found the ciprofloxacin resistance rate was higher than that for sparfloxacin, gatifloxacin, levofloxacin and moxifloxacin. A reason for this high resistance may be that ciprofloxacin is often used in the treatment of urinary tract and respiratory infections (Stamm and Stapleton, 1998). In this study, only one H. pylori isolate was resistant either to levofloxacin or moxifloxacin. Levofloxacin has better tissue penetration and fewer side effects than ciprofloxacin (Croom and Goa, 2003). Moxifloxacin has good penetration and accumulates in the gastric mucosa (Wirtz et al, 2004). Based on this study, most H. pylori isolates in Jakarta are beginning to be resistant to antibiotics, notably those often used in standard treatment, such as clarithromycin, metronidazole and amoxicillin. Metronidazole, due to 100% resistance, is no longer effective in the eradication of H. pylori. Instead, the fluoroquinolone group may be more effective in eradicating H. pylori. 972 Vol 37 No. 5 September 2006

PATTERNS OF H. PYLORI RESISTANCE TO SOME ANTIBIOTICS ACKNOWLEDGEMENTS The authors wish to thank dr Bambang Handana for kindly providing biopsy tissue from the Endoscopy Unit, Graha Medika Hospital in Jakarta. Also thanks to Dr Ari Fahrial Syam, Department of Internal Medicine, Faculty of Medicine. Indonesia University and Dr Cipto Mangunkusumo General National Hospital. REFERENCES Achmad H. Pola uji resistensi in vitro isolat Helicobacter pylori daerah Malang terhadap antibiotik (In vitro resistance pattern against antibiotic in Malang). Malang, Indonesia. Pharos Bull 1996; 3: 3-7 (In Indonesian). Berger SA, Gorea A, Moskowitz M, et al. Effect of inoculum size on antimicrobial susceptibility of Helicobacter pylori. Eur I Clin Microbiol Infect Dis 1993; 12: 782-3. Birac C, Bouchard S, Camou C, et al. Six years follow-up of resistance to antibiotics of Helicobacter pylori in Bordeaux, France.Gut 1999 ;45(suppl 3): A107. Blaser MJ, Chyou PH, Nomura A. Age at establishment of Helicobacter pylori infection and gastric carcinoma, gastric ulcer and duodenal ulcer risk. Research 1995; 55: 562-5. Boyanova L, Mentis A, Gubina M, et al. The status of antimicrobial resistance of Helicobacter pylori in eastern Europe. Clin Microbiol Infect 2002; 8: 388-96. Clinical and Laboratory Standards Intitute (CLSI)/ NCCLS. Performance standards for antimicrobial disk susceptibility tests. 8 th ed. Approved Standard M2-A8. Wayne, PA: CLSI/NCCLS, 2005. Croom KF, Goa KL. Levofloxacin: a review of its use in the treatment of bacterial infections in United State. Drugs 2003; 63: 2769-802. Francesco VD, Margiotta M, Zullo A, et al. Clarithromycin resistant genotypes and eradication of Helicobacter pylori. Ann Int Med 2006;144: 94-100. Hartzen SH, Andersen LP, Bremmelgaard A, Colding H, Arpi M, Kristiansen J. Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time. Antimicrob Agents Chemother 1997; 41: 2634-9. Jenks PJ, Labigne A, Ferrero LR. Exposure to metronidazol in vivo readily induces resistance in Helicobacter pylori and reduces the efficacy of eradication therapy in mice. Antimicrob Agents Chemother 1999; 43: 777-81. Ketut M. Prevalensi Helicobacter pylori pada evaluasi histopatologik biopsy endos-kopi penderita gastritis kronik (Prevalence of Helicobacter pylori in gastric biopsies histopathology evaluation of chronic gastritis). Proceedings of the National Symposium Helicobacter pylori and Gastroduodenal disease. Denpasar Bali, 25 Mar 1995: 13-26. Kumala W, Rahim A, Sudarmono P, Rani A. Motility indole urease as an alternative diagnostic method for identifying Helicobacter pylori. Indon J Gastroenterol Hepatol Dig Endosc 2001; 2: 5-7. Kupiers EJ. Review article: exploring the link between Helicobacter pylori and gastric cancer. Aliment Pharmacol Ther 1999; 13 (suppl 1): 3-11. Kwon DH, Pena JA, Osato MS, et al. Frameshift mutations in rdxa and metronodazole resistance in North America Helicobacter pylori isolates. J Antimicrob Chemother 2000; 46: 793-6. Lee A. Update in Helicobacter pylori infection and its link to malignancy: Pathogenesis of infection. Singapore: Proceeding of the 5 th Western Pacific Congress on Chemotherapy and Infectious Diseases. 1-4 Dec 1996: 187-90. Loivukene K, Maaroos HI, Kolk H, et al. Prevalence of antibiotic resistant Helicobacter pylori isolates in Estonia during 1995-2000 in comparison to the consumption of antibiotics used intreatment regimens. Clin Microbiol infect 2002; 8: 598-603. Marshall BJ. Helicobacter pylori. The etiologic agent for peptic ulcer. JAMA SEA 1996; 12: 28-30. Matsumura M, Hikiba Y, Ogura K, et al. Rapid detection of mutations in the 23S rrna gene of Vol 37 No. 5 September 2006 973

Helicobacter pylori that confers resistance to clarithromycin treatment to the bacterium. J Clin Microbiol 2001; 39: 691-5. Megraud F. H.pylori antibiotic resistanc: prevalence, importance and avances in testing. GUT 2004; 53: 1374-84. Mitchell HM. The epidemiology of Helicobacter pylori. Curr Top Microbiol Immunol 1999; 241: 11-30. Paul R, Postius S, Melchers K, et al. Mutations of the Helicobacter pylori genes rdxa and pbp1cause resistance against metronidazole and amoxicillin. Antimicrob Agents Chemother 2001; 45: 962-5. Perez AL, Kato M, Nakagawa S, et al. The relationship between consumption of antimicrobial agents and the prevalence of primary Helicobacter pylori resistance. Helicobacter 2002; 7: 306-9. Quintana-Guzman EM, Arias-Echandi ML, Chaves SP, Davidovich-Rose H, Schosinsky- Neverman K. Helicobacter pylori: susceptibility to amoxycillin, erythromycin, tetracycline, ciprofloxacin, nitrofurantoin and metronidazole in Costa Rica. Rev Biomed 1998; 9: 92-6. Rourke OK, Goodman KJ, Grazioplene M, Redlinger T, Day SR. Determinants of geographic variation in Helicobacter pylori infection among children on the US-Mexico border. Am J Epidemiol 2003; 158: 816-24. Stamm WE, Stapleton AE. Approach to the patient with urinary tract infection. In: Gorbach St, Barlett JG, Blacklow NR, eds. Infectious diseases. Philadelpia: Saunders Comp, 1998: 443-54. Suate K, Suyasa GN. Helicobacter pylori: Aspek mikrobiologik dan pola kepekaannya terhadap antimikroba (Microbiology aspect and resistant pattern against antimicrobial agents). Proceedings of the National Symposium on Helicobacter pylori and Gastroduodenal Disease. Denpasar Bali, 25 Mar 1995: 13-26. Thyagarajan SP, Ray P, Das BK, et al. Geographical difference in antimicrobial resistance pattern of Helicobacter pylori clinical isolates from India patients: multicentric study. J Gastroenterol Hepatol 2003; 18: 1373-8. Torres J, Camorlinga-Ponce M, Perez-Perez G, et al. Increasing multidrug resistance in Helicobacter pylori strains isolated from children and adults in Mexico. J Clin Microbiol 2001; 9: 2677-80. Walt RP. Metronidazole resistant Helicobacter pylori of questional clinical importance. Lancet 1996; 348: 489-90. Wirtz M, Kleeff J, Swoboda S, et al. Moxifloxacin penetration into human gastrointestinal tissues. J Antimicrob Chemother 2004; 53: 875-7. Wu H, Shi XD, Wang HT, et al. Resistsance of Helicobacter pylori to metronidazole, tetracycline and amoxicillin. J Antimicrob Chemother 2000; 46: 121-3. Zeiler HJ, Grohe K. The in vitro and in vivo activity of ciprofloxacin. Eur J Clin Microbiob 1984; 3: 339-43. 974 Vol 37 No. 5 September 2006