Efflux pump gene hefA of Helicobacter pylori plays an important role in multidrug resistance.

AIM To determine whether efflux systems contribute to multidrug resistance of H pylori. METHODS A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC11637) was developed. Multidrug-resistant (MDR) strains were selected and the minimal inhibitory concentration (MIC) of erythromycin, metronidazole, penicillin G, tetracycline, and ciprofloxacin in multidrug resistant strains and their parent strains was determined by agar dilution tests. The level of mRNA expression of hefA was assessed by fluorescence real-time quantitative PCR. A H pylori LZ1026 knockout mutant (delta H pylori LZ1026) for (putative) efflux protein was constructed by inserting the kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were evaluated. RESULTS The MIC of six multidrug-resistant strains (including 5 clinical isolates and H pylori NCTC11637) increased significantly (>or=4-fold) compared with their parent strains. The expression level of hefA gene was significantly higher in the MDR strains than in their parent strains (P=0.033). A H pylori LZ1026 mutant was successfully constructed and the delta H pylori LZ1026 was more susceptible to four of the 10 antibiotics. All the 20 strains displayed transcripts for hefA that confirmed the in vitro expression of these genes. CONCLUSION The efflux pump gene hefA plays an important role in multidrug resistance of H pylori.

[1]  Gilberto de Lima Lopes Junior,et al.  Controversies in colorectal cancer: First line treatment with epidermal growth factor inhibitors and RAS in 2014 , 2014, Indian Journal of Medical and Paediatric Oncology.

[2]  J. Rose,et al.  Detection of Helicobacter pylori in sewage and water using a new quantitative PCR method with SYBR® green , 2007, Journal of applied microbiology.

[3]  J. Kukor,et al.  Cloning and characterization of monofunctional catalase from photosynthetic bacterium Rhodospirillum rubrum S1. , 2007, Journal of microbiology and biotechnology.

[4]  H. Zgurskaya,et al.  Drug-Induced Conformational Changes in Multidrug Efflux Transporter AcrB from Haemophilus influenzae , 2007, Journal of bacteriology.

[5]  T Rokkas,et al.  Current concepts in the management of Helicobacter pylori infection: the Maastricht III Consensus Report , 2006, Gut.

[6]  Y. Que,et al.  Detection of Live and Antibiotic-Killed Bacteria by Quantitative Real-Time PCR of Specific Fragments of rRNA , 2006, Antimicrobial Agents and Chemotherapy.

[7]  M. Mulvey,et al.  Expression of the mef(E) Gene Encoding the Macrolide Efflux Pump Protein Increases in Streptococcus pneumoniae with Increasing Resistance to Macrolides , 2005, Antimicrobial Agents and Chemotherapy.

[8]  K. Poole,et al.  Induction of the MexXY Efflux Pump in Pseudomonas aeruginosa Is Dependent on Drug-Ribosome Interaction , 2005, Journal of bacteriology.

[9]  B. D. de Jonge,et al.  Compound Efflux in Helicobacter pylori , 2005, Antimicrobial Agents and Chemotherapy.

[10]  A. van der Ende,et al.  A Helicobacter pylori TolC Efflux Pump Confers Resistance to Metronidazole , 2005, Antimicrobial Agents and Chemotherapy.

[11]  S. Crowe Helicobacter infection, chronic inflammation, and the development of malignancy , 2005, Current opinion in gastroenterology.

[12]  R. Hunt,et al.  Helicobacter pylori Public Health Implications , 2004, Helicobacter.

[13]  M. Ullrich,et al.  NorM, an Erwinia amylovora Multidrug Efflux Pump Involved in In Vitro Competition with Other Epiphytic Bacteria , 2004, Applied and Environmental Microbiology.

[14]  V. Koronakis TolC – the bacterial exit duct for proteins and drugs , 2003, FEBS letters.

[15]  Xiao-kui Guo,et al.  Deletion of Helicobacter pylori vacuolating cytotoxin gene by introduction of directed mutagenesis. , 2003, World journal of gastroenterology.

[16]  M. Valvano,et al.  Cloning and characterization of the Burkholderia vietnamiensis norM gene encoding a multi-drug efflux protein. , 2002, FEMS microbiology letters.

[17]  K. Nelson,et al.  Comparative genomics of microbial drug efflux systems. , 2001, Journal of molecular microbiology and biotechnology.

[18]  A R Walmsley,et al.  The structure and function of drug pumps. , 2001, Trends in microbiology.

[19]  M. Putman,et al.  Molecular Properties of Bacterial Multidrug Transporters , 2000, Microbiology and Molecular Biology Reviews.

[20]  B. Ho,et al.  Expression of histo-blood group antigens by lipopolysaccharides of Helicobacter pylori strains from asian hosts: the propensity to express type 1 blood-group antigens. , 2000, Glycobiology.

[21]  J. Bina,et al.  Helicobacter pylori Uptake and Efflux: Basis for Intrinsic Susceptibility to Antibiotics In Vitro , 2000, Antimicrobial Agents and Chemotherapy.

[22]  G. Church,et al.  Alignment and structure prediction of divergent protein families: periplasmic and outer membrane proteins of bacterial efflux pumps. , 1999, Journal of molecular biology.

[23]  H. Nikaido Antibiotic resistance caused by gram-negative multidrug efflux pumps. , 1998, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[24]  C. O'Morain,et al.  Treatment of Helicobacter pylori , 2005, Helicobacter.

[25]  H. Nikaido,et al.  Active efflux of fluoroquinolones in Mycobacterium smegmatis mediated by LfrA, a multidrug efflux pump , 1996, Journal of bacteriology.

[26]  M. Saier,et al.  Two novel families of bacterial membrane proteins concerned with nodulation, cell division and transport , 1994, Molecular microbiology.

[27]  B. Marshall,et al.  UNIDENTIFIED CURVED BACILLI IN THE STOMACH OF PATIENTS WITH GASTRITIS AND PEPTIC ULCERATION , 1984, The Lancet.

[28]  BMC Molecular Biology BioMed Central Methodology article , 2006 .

[29]  M. Michéa-Hamzehpour,et al.  In vitro stepwise selection of resistance to quinolones, β-lactams and amikacin in nosocomial gram-negative bacilli , 2005, Infection.

[30]  H. Imberechts,et al.  The AcrB multidrug transporter plays a major role in high-level fluoroquinolone resistance in Salmonella enterica serovar typhimurium phage type DT204. , 2002, Microbial drug resistance.

[31]  S. Jo,et al.  A simple method to construct T-vectors using XcmI cassettes amplified by nonspecific PCR. , 2001, Plasmid.

[32]  Copyright © 1997, American Society for Microbiology , 1996 .