Bacterial Proteins ; Humans ; Metronidazole/pharmacology* ; Mycobacterium tuberculosis ; NAD ; Nitroreductases ; Tuberculosis, Lymph Node

OBJECTIVETo demonstrate the correlation of rdxA gene mutation and metronidazole (MTZ) resistance of H.pylori isolates in the local area.

METHODSClinical strains of H.pylori were isolated from gastric biopsy of patients. Resistance to metronidazole of the isolates was determined by using diffusion test and two fold dilution test. Genome DNAs of the isolates were prepared for PCR to detect rdxA gene. The target amplification products were sequenced after T-A cloning. The sequences were compared with the reported sequences from Hp26695 and 134 other strains of H.pylori.

RESULTSMTZ resistance rate was 76.1% in 21 clinical isolates. The target fragment 886 bp in length containing rdxA gene could be successfully amplified. In comparison with the reported corresponding sequence of H.pylori stain 26695, homologies of the nucleotide sequences from the amplification products were 90.1% approximate, equals 95.1%. Mutations caused by base insertion/deletion and substitution in the MTZ resistance isolates were found. Among these mutations, two types of insertion mutations have not been reported in literatures. No same mutations were present in the MTZ sensitive isolates.

CONCLUSIONThe rdxA gene mutation may play an important role in MTZ resistance of H.pylori.

Amino Acid Sequence ; Drug Resistance, Bacterial ; Helicobacter pylori ; drug effects ; genetics ; Metronidazole ; pharmacology ; Molecular Sequence Data ; Mutation ; Nitroreductases ; chemistry ; genetics

OBJECTIVETo investigate the prevalence of resistance of Helicobacter pylori (H. pylori) to metronidazole (MTZ) and the distribution change of minimal inhibitory concentrations (MICs) in H. pylori from local children, evaluate the applicability of E-test for MIC determination, and display the propensity of acquired-resistance to MTZ after induction of resistance in vitro.

METHODSOne group of 44 H. pylori isolates obtained from Oct. 2002 to Nov. 2003 and another 83 H. pylori isolates obtained from Dec. 2004 to Jul. 2005 from the local children who underwent gastroscopy in the Children's Hospital affiliated to Zhejiang University Medical School and were diagnosed as H. pylori-associated gastritis or peptic ulcer were studied. Susceptibility was tested by agar dilution method or E-test method. In 11 randomly selected metronidazole-sensitive isolates (MTZ(S)), resistance was induced in vitro with MTZ.

RESULTSThe resistance rate was 31.8% (14/44) in the 44-islates obtained from Oct. 2002 to Nov. 2003 and 51.8% (43/83) (chi(2) = 4.64, P < 0.05) in 83-isolates obtained from Dec. 2004 to Jul. 2005, respectively. The distribution of MICs were < 0.125 - 128 mg/L and 0.25- > 256 mg/L, in which, the MIC(50) was 0.5 mg/L and 16 mg/L, the MIC(90) was 128 mg/L, respectively. Comparing to agar dilution method which is recommended by National Committee for Clinical Laboratory Standards (NCCLS) for MIC, E-test was significantly associated with agar dilution method (chi(2) = 32.38, P < 0.001). The sensitivity, specificity, agreement rate of E-test were 73.08%, 100%, 87.27%, respectively, while there were factors of 2(2) to 2(6) difference in MICs between the results obtained by E-test and agar dilution. For all the 11 MTZ(S) isolates inducted resistance in vitro with MTZ, 16 MICs were achieved through 7 - 9 (7.2 +/- 0.6) passages of induction in vitro, and 100% acquired-resistance to MTZ through 8 - 10 generations; as a result, 10 of 11 MTZ(S) isolates achieved stable high-level resistance (256 mg/L for 2 and > 256 mg/L for 8) and 1 stable 64 mg/L resistance to MTZ.

CONCLUSIONSThe prevalence of resistance to MTZ seems to be increasing in H. pylori from local children. To avoid missed diagnosis of H. pylori resistant to MTZ (MTZ(R)), agar dilution method was needed when detecting susceptibility of H. pylori to MTZ. Resistance to MTZ of H. pylori from children is readily induced in vitro.

Anti-Bacterial Agents ; pharmacology ; Child ; Helicobacter Infections ; drug therapy ; epidemiology ; Helicobacter pylori ; drug effects ; Humans ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; Prevalence

AIMTo prepare bioadhesive microspheres of metronidazole (Metro) with prolonging resident time in the stomach and sustaining drug release.

METHODSThe microspheres were prepared by a drying-in-liquid method. The appearance, particle size and drug release in vitro were examined. The factors influencing bioadhesive property and drug release, such as ethyl cellulose (EC)/carbopol 934P (CP) ratio, particle size and Metro content were investigated.

RESULTSThe average diameter of the Metro-EC-CP microspheres was 559.9 microns. The release profiles of metronidazole were shown to fit to first-order equations well. With the increase of CP content in the Metro-EC-CP microspheres, the microspheres showed better mucoadhesion and faster drug release. The drug release rate decreased with the increase of particle size and the decrease of Metro content.

CONCLUSIONThe Metro-EC-CP microspheres have a sound mucoadhsive property and sustained drug release when the ratio of EC and CP was 17:3 and Metro content was 25%. The drug release was shown to last for 8 h in 0.1 mol.L-1 hydrochloric acid.

Acrylates ; Animals ; Anti-Infective Agents ; administration & dosage ; pharmacology ; Cell Adhesion ; Delayed-Action Preparations ; Female ; Fluorocarbons ; chemistry ; Gastric Mucosa ; physiology ; Metronidazole ; administration & dosage ; pharmacology ; Microspheres ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo isolate and culture the predominant anaerobes from the periodontal abscesses, and to test the antibiotic susceptibility and drug resistant genes of the strains.

METHODSThe isolated strains were identified by both API20A biochemical method and polymerase chain reaction (PCR) method. The antibiotic susceptibility test was performed by agar dilution method. The resistant genes of the drug-resistant strains obtained were screened by PCR.

RESULTSThe anaerobes were detected in 48% (28/58) of the samples and Prevotella melaninogenica (Pm) was mostly identified in 43% (12/28). API20A biochemical method had 82% (23/28) agreement with the 16SrRNA method in identification rate. Anaerobes were resistant to metronidazole, clindamycin and cefmetazole. The erythromycin-resistant methylase genes F (ermF) gene was detected in three of eight clindamycin resistant strains. None of them was found coded on bacterial plasmids. However, no metronidazole resistant gene was detected on drug resistant strains.

CONCLUSIONSPm was the predominant species dectected in the periodontal abscess of the patients. The antibiotic agents should be used based on the genotypes and general condition of the patients.

Adult ; Anti-Bacterial Agents ; pharmacology ; Bacteria, Anaerobic ; isolation & purification ; Cefmetazole ; pharmacology ; Clindamycin ; pharmacology ; Drug Resistance, Bacterial ; genetics ; Erythromycin ; pharmacology ; Female ; Genes, Bacterial ; Humans ; Male ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Periodontal Abscess ; microbiology ; Prevotella ; isolation & purification

OBJECTIVETo investigate the resistance of Helicobacter pylori (H. pylori) to antimicrobial agents in adolescents.

METHODSOne hundred and eight adolescents (6-18 years old) underwent a gastroscopy examination. H. pylori strains were isolated from gastric mucosa. Antimicrobial susceptibility testing was performed by means of Kirby-Baner.

RESULTSThirty-six H. pylori strains were identified. The resistant rate of H. pylori strains to clarithromycin, fruranzolidone and amoxicillin was 8.3%, 16.7% and 33.3%, respectively. H. pylori strains showed a high resistance to metronidazole (94.4%), while no strain was resistant to gentamicin and levofloxacin.

CONCLUSIONSThe H. pylori strains from the adolescents in Zhejiang showed a high resistance to metronidazole and amoxicillin but a low resistance to clarithromycin and fruranzolidone. All of H. pylori strains were susceptive to gentamicin and levofloxacin.

Adolescent ; Amoxicillin ; pharmacology ; Anti-Infective Agents ; pharmacology ; Child ; Clarithromycin ; pharmacology ; Drug Resistance, Bacterial ; Female ; Gastroscopy ; Helicobacter pylori ; drug effects ; Humans ; Levofloxacin ; Male ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; Ofloxacin ; pharmacology

One of the most common drugs used against a wide variety of anaerobic protozoan parasites is metronidazole. However, this drug is mutagenic for bacteria and is a potent carcinogen for rodents. Thymus vulgaris is used for cough suppression and relief of dyspepsia. Also it has antibacterial and antifungal properties. The aim of this study was to investigate antiamebic effect of Thymus vulgaris against Entamoeba histolytica in comparison with metronidazole. One hundred gram air-dried T. vulgaris plant was obtained and macerated at 25 degrees C for 14 days using n-hexane and a mixture of ethanol and water. For essential oil isolation T. vulgaris was subjected to hydrodistillation using a clevenger-type apparatus for 3 hr. E. histolytica, HM-1: IMSS strain was used in all experiments. It was found that the minimal inhibitory concentration (MIC) for T. vulgaris hydroalcoholic, hexanic extracts, and the essential oil after 24 hr was 4 mg/mL, 4 mg/mL, and 0.7 mg/mL, respectively. After 48 hr the MIC for T. vulgaris hydroalcoholic and hexanic extracts was 3 and 3 mg/mL, respectively. Therefore, it can be concluded that the Iranian T. vulgaris is effective against the trophozoites of E. histolytica.
Animals ; Antiprotozoal Agents/chemistry/*pharmacology ; Dose-Response Relationship, Drug ; Entamoeba histolytica/*drug effects ; Iran ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Plant Extracts/chemistry/*pharmacology ; Plant Oils/chemistry/pharmacology ; Thymus Plant/*chemistry

OBJECTIVETo investigate the prevalence of Helicobacter pylori (Hp) resistant to clarithromycin, amoxicillin and metronidazole in children.

METHODSA total of 44 Hp clinical isolates were cultured from children patients with Hp gastritis and peptic ulcer who underwent gastroscopy during the period from October 2002 to November 2003 in Children's Hospital affiliated to Medical College of Zhejiang University. Nineteen of the patients were girls and 25 boys. The mean age was 8.66 +/- 2.66 years (3 approximately 14 years). The susceptibilities of the 44 Hp strains to clarithromycin, amoxicillin and metronidazole were tested by agar dilution test to determine minimum inhibitory concentration (MIC)(50), MIC(90) and resistance rates were also calculated.

RESULTSAmong the 44 Hp strains isolated from children, 8, 4, and 14 strains were resistant to clarithromycin, amoxicillin and metronidazole and the resistant rate was 18.2% (8/44), 9.1% (4/44) and 31.8% (14/44), with MICs for all strains ranging from < 0.125 microg/ml to 64 microg/ml, < 0.125 microg/ml to 64 microg/ml and < 0.125 microg/ml to 128 microg/ml, respectively. MIC(50) and MIC(90) of clarithromycin, amoxicillin and metronidazole were < 0.125 microg/ml, 8 microg/ml; < 0.125 microg/ml, 0.5 microg/ml; 0.5 microg/ml, 128 microg/ml, respectively. The prevalence of Hp resistant to clarithromycin was higher in children than that in adults, while to metronidazole was lower than that in adults with high MICs (32 - 128 microg/ml) and MIC(90) (128 microg/ml) of metronidazole for resistant isolates. Three multidrug resistant strains (6.8%) were simultaneously resistant to these three antibiotics.

CONCLUSIONSThe prevalence of Helicobacter pylori resistant to metronidazole was high in children, and the rate of resistance to clarithromycin was higher than that isolated from adults. Amoxicillin-resistant strains were now found, and multidrug resistant strains which resistant to the three antibiotics also emerged.

Adolescent ; Amoxicillin ; pharmacology ; Anti-Bacterial Agents ; pharmacology ; Child ; Child, Preschool ; Clarithromycin ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Female ; Gastritis ; microbiology ; Gastroscopy ; Helicobacter pylori ; drug effects ; isolation & purification ; Humans ; Male ; Metronidazole ; pharmacology ; Microbial Sensitivity Tests ; Peptic Ulcer ; microbiology ; Prevalence

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.
Amoxicillin/pharmacology ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Aza Compounds/pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; *Drug Resistance, Bacterial ; Female ; Helicobacter Infections/*epidemiology/microbiology ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Male ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Ofloxacin/pharmacology ; Quinolines/pharmacology ; Republic of Korea/epidemiology ; Tetracycline/pharmacology

BACKGROUND/AIMS: This study was performed to compare the prevalence rates of primary antibiotic resistance in Helicobacter pylori (H. pylori) isolates among different regions of Korea. METHODS: H. pylori were isolated from gastric mucosal biopsy specimens of 99 Koreans who lived in Gyeonggi (n=40), Kangwon province (n=40) and Busan (n=19) from April to August in 2008. All the patients had no history of H. pylori eradication therapy. The susceptibilities of the H. pylori isolates to amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin were tested according to the agar dilution method. RESULTS: There was a difference in resistance to clarithromycin in three institutes located among Gyeonggi (32.5%), Kangwon province (12.5%) and Busan (42.1%) by One way ANOVA test (p=0.027) and nonparametric Kruskal Wallis test (p=0.027). However, by post-hoc analysis, there was no statistically significant difference among three regions. Similarly, the other 7 antibiotics (amoxicillin, metronidazole, tetracycline, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin) did not show any significant difference. CONCLUSIONS: There was no significant regional difference of the primary antibiotic resistance of H. pylori. However, the included patient number might not be enough for this conclusion demanding further evaluations.
Amoxicillin/pharmacology ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Aza Compounds/pharmacology ; Azithromycin/pharmacology ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; *Drug Resistance, Bacterial ; Female ; Helicobacter Infections/*epidemiology/microbiology ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Male ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Middle Aged ; Ofloxacin/pharmacology ; Quinolines/pharmacology ; Republic of Korea/epidemiology ; Tetracycline/pharmacology