Primary clarithromycin resistance in Italy assessed on Helicobacter pylori DNA sequences by TaqMan real‐time polymerase chain reaction

Abstract

SUMMARY BackgroundHelicobacter pylori clarithromycin resistance is increasing worldwide and different mutations are involved in its mechanisms. Recently, molecular methods have been proposed to assess these mutations.

Susceptibility of Helicobacter pylori to Antibiotics Including Tigecycline

“…All the strains isolated from children were susceptible to tetracycline [3]. Earlier studies conducted in Italy showed that primary resistance to clarithromycin was high (18.4% -26.7%) in Central and South Italy and similar to 23% reported in another Italian study [9][10][11][12]. These percentages are higher than 1.8% and 14% found in studies conducted about ten years ago [13,14] suggesting an increase of resistance rate over time.…”

“…Primary clarithromycin resistance has emerged worldwide. In Italy, a primary resistance of 26.7% for clarithromycin and of 17.2% for metronidazole has been reported [9,10]. A study conducted to assess the primary antibacterial resistance rates of H. pylori in 18 European countries found a H. pylori resistance rate in adults of 17.5% for clarithromycin, 14.1% for levofloxacin, 34.9% for metronidazole, 0.7% for amoxicillin, 0.9% for tetracycline and 1.1% for rifabutin.…”

Clarithromycin-resistant Helicobacter pylori in Recife, Brazil, directly identified from gastric biopsies by polymerase chain reaction

“…This was probably due to the design of the qPCR assay. First, it was built with TaqMan ® minor groove binding (MGB) probes (2) . The efficiency of MGB probes for distinguishing a singlebase mismatch on DNA targets has been established (5,20) .…”

“…qPCR assays were directed for detecting four alleles in domain V of the 23S rRNA gene, the wild-type, and the point mutations A2142G, A2143G, and A2142C, associated with macrolide resistance in H. pylori (10,19) . For molecular tests, we used an identical TaqMan ® PCR technique, with probes and primers exactly as previously designed (2) . Primers and probes, synthesized by Applied Biosystems, Incorporated, Foster City, CA.…”

“…The aims of this study were to determine the prevalence of clarithromycin resistance in Recife, a city in Northeast Brazil; identify the point mutations responsible for this resistance; and to compare the TaqMan ® qPCR assay (2) directly applied to gastric biopsies with matched isolates examined by Etest.…”