Helicobacter pylori suşlarında genotipik farklılıkların ve ilaç direncinin saptanması
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Date
2008
Authors
Özbey, Saliha Bakır
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Publisher
Uludağ Üniversitesi
Abstract
Helicobacter pylori enfeksiyonu dünyada yaygın olarak görülen kronik bakteriyel enfeksiyonlardan biridir. H pylori enfeksiyonu kronik gastrit, peptik ülser ve gastrik kanser ile illşkilidir. H pylori’de antibiyotiklere karşı gelişen direnç tedavide başarısızlığa neden olmaktadır. Son yıllarda bu direnç oranı giderek artmaktadır. cag patojenite adası (cagPAI) H pylori’nin majör virulans faktörüdür. Ancak, H pylori enfeksiyonunun klinik sonucu cagA, cagT ve cagE de dahil olmak üzere bazı cagPAI genlerinin analiziyle tam olarak öngörülememektedir. Bu çalışmada 31 H pylori izolatının klaritromisin, amoksisilin, metronidazol, tetrasiklin ve siprofloksasin duyarlılığı E test yöntemi ile çalışıldı. Sırasıyla %41.9, %3.2, %41.9, %3.2 ve %45.2 oranlarında direnç saptandı. Tek antibiyotiğe direnç %32.2, çoklu direnç ise %45.2 oranında bulundu. Klaritromisin direnci ayrıca FISH (Floresan In Situ Hibridizasyon) yöntemi ile çalışıldı. Klaritromisin direncini saptamada her iki yöntem arasında fark saptanmadı. Ayrıca 50 H pylori isolatı (21 ülser, 20 gastrit ve 9 nonülser dispepsi) PCR ile incelendi. Sekiz primer çifti (cagA1, cagA2, cagAP1, cagAP2, cagE, cagT, LEC1 ve LEC2) kullanılarak cag PAI genlerinden beş farklı lokusun (cagA, cagA promoter bölgesi ve cagE’nin olduğu cagPAI-I bölgesi ile cagT ve LEC’in olduğu cagPAI-ІІ bölgesi ) varlığı incelendi. On hastada (%20) intakt cagPAI saptandı. Suşların %36’sında cagA geni bulunurken cagE ve cagT genleri sırasıyla %64 ve %58 olarak saptandı. cagPAI genleri ile klinik sonuçlar arasında anlamlı bir ilişki saptanmadı. Bu çalışma cagE’nin varlığının cagA ile değil cagT ile ilişkili olduğunu göstermiştir. (p=0.003). Bununla birlikte cag promoter bölgesi %58 ve LEC bölgesi de %56 oranında saptandı. Bu da, bu iki genin de virülansa katkıda bulunduğunu desteklemektedir.
Helicobacter pylori infection is one of the common seen chronic bacterial infections in the world. H pylori infection is associated with a variety of clinical outcomes ranging from to chronic gastritis, peptic ulcer disease and gastric cancer. H pylori acquired resistance to antimicrobial agent treatment failure occurs. The resistance rate has been increasing in the past years. The cag pathogenicity island (cagPAI) is on of the majör virulence determinants of H pylori. Howover, the clinical outcome of H pylori infection is not reliably predicted by analyzing several genes of the cagPAI, including cagA, cagT and cagE. In this study 31 H pylori isolates examined for sensitivity to clarithromycin, amoxicillin, metronidazole, tetracycline and ciprofloxacin by E-test method The resistance rates were 41.9%, 3.2%, 41.9%, 3.2%, and 45.2%.respectively. The single resistance rate to antibiotics was found to be 32.2%, the multiple resistance rate on the other hand was found to be 45.2%. Susceptibility to clarithromycin was tested by E-test and FISH (Fluorescent In Situ Hybridization). No discrepancies were found between both methods. In addition, H pylori strains from 50 patients (21 ulser, 20 gastritis and 9 nonulser dispepsi) were analyzed using PCR. Eight pairs of oligonucleotid primers (cagA1, cagA2, cagAP1, cagAP2, cagE, cagT, LEC1 ve LEC2) of five different loci (cagA, cagA promoter region, cagE which represents cagPAI-I region and cagT, LEC representing cagPAI-II region) were used to detect the presence of the cag PAI genes. Intact cagPAI has been determined in 10 patients (20%). CagA gene was present in 36% of strain while cagE and cag T genes were present in 64% and 58% respectively. No association could be discerned between the presence of cagPAI genes and the clinical outcome. This study revealed consistency in the presence of cagE with cagT but not cagA. (p=0.003). Howover, the cag promoter region and the LEC region has been determined for 58%, 56% respectively. This supports that these two genes have an impact on the virulence.
Helicobacter pylori infection is one of the common seen chronic bacterial infections in the world. H pylori infection is associated with a variety of clinical outcomes ranging from to chronic gastritis, peptic ulcer disease and gastric cancer. H pylori acquired resistance to antimicrobial agent treatment failure occurs. The resistance rate has been increasing in the past years. The cag pathogenicity island (cagPAI) is on of the majör virulence determinants of H pylori. Howover, the clinical outcome of H pylori infection is not reliably predicted by analyzing several genes of the cagPAI, including cagA, cagT and cagE. In this study 31 H pylori isolates examined for sensitivity to clarithromycin, amoxicillin, metronidazole, tetracycline and ciprofloxacin by E-test method The resistance rates were 41.9%, 3.2%, 41.9%, 3.2%, and 45.2%.respectively. The single resistance rate to antibiotics was found to be 32.2%, the multiple resistance rate on the other hand was found to be 45.2%. Susceptibility to clarithromycin was tested by E-test and FISH (Fluorescent In Situ Hybridization). No discrepancies were found between both methods. In addition, H pylori strains from 50 patients (21 ulser, 20 gastritis and 9 nonulser dispepsi) were analyzed using PCR. Eight pairs of oligonucleotid primers (cagA1, cagA2, cagAP1, cagAP2, cagE, cagT, LEC1 ve LEC2) of five different loci (cagA, cagA promoter region, cagE which represents cagPAI-I region and cagT, LEC representing cagPAI-II region) were used to detect the presence of the cag PAI genes. Intact cagPAI has been determined in 10 patients (20%). CagA gene was present in 36% of strain while cagE and cag T genes were present in 64% and 58% respectively. No association could be discerned between the presence of cagPAI genes and the clinical outcome. This study revealed consistency in the presence of cagE with cagT but not cagA. (p=0.003). Howover, the cag promoter region and the LEC region has been determined for 58%, 56% respectively. This supports that these two genes have an impact on the virulence.
Description
Keywords
Helicobacter pylori, Cag patojenite adası, Antibiyotik direnci, E test, FISH, Cag pathogenicity island, Antibiotic resistance
Citation
Özbey, S. B. (2008). Helicobacter pylori suşlarında genotipik farklılıkların ve ilaç direncinin saptanması. Yayınlanmamış uzmanlık tezi. Uludağ Üniversitesi Tıp Fakültesi.