The distribution of minimal inhibitory concentrations (MIC) for amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, and fluoroquinolone (ciprofloxacin, levofloxacin, and moxifloxacin) have shifted to higher concentrations from 1987 to 2003 in Helicobacter pylori (H. pylori) strains isolated from Korean patients. MIC values of secondary isolates were higher than those of primary isolates. Of treatment-failure patients, 16.4% showed mixed infections with both antibiotic-susceptible and -resistant H. pylori strains. A total of 89.6% of patients with treatment failure and 52.3% of patients without antibiotic treatment had H. pylori strains resistant to two or more antimicrobial agents (multi-drug resistance, MDR). The most common antibiotics showing MDR were clarithromycin, metronidazole, and azithromycin. The resistance rates to both amoxicillin and clarithromycin were 34.3% in secondary isolates and 6.2% in primary isolates. The resistance rates to both clarithromycin and metronidazole were 73.1% in secondary isolates and 7.7% in primary isolates. In addition, there was a significant difference in antibiotic resistance between two institutions located at Seoul and Gyeonggi provinces. To provide adequate informations about susceptible antibiotics to clinicians, continuous surveillance of antibiotic susceptibilities is needed in Korea.
*Drug Resistance, Bacterial ; Drug Resistance, Multiple, Bacterial ; Helicobacter pylori/*drug effects/isolation & purification ; Humans ; Korea ; Microbial Sensitivity Tests

Anti-Bacterial Agents ; administration & dosage ; adverse effects ; therapeutic use ; Bacteria ; drug effects ; metabolism ; Bacterial Infections ; drug therapy ; Drug Resistance, Bacterial ; drug effects ; Humans ; Infant, Newborn ; Superinfection ; drug therapy

OBJECTIVE7 variable but nonculturable-state strains of Enterotoxigenic Escherichia coli (ETEC) during the routine bacterial subculture were found in our lab and their morphology and antigen studied. Biological features, antigens and pathogenicity of the revertants were also tested and compared to that of the initial strains in order to detect their variations.

METHODSBiological variations between the variable but nonculturable-state and the revertant of every strain were detected, using the routine gram-staining, reverting the isolates in animal intestinal, reverting their pathogenicity, serological agglutination, biochemical identifications and antibiotic resistance tests.

RESULTSFor the 7 variable but nonculturable-state strains of ETEC,other than the trains that had changed into sphero vegetale cells, there were no other obvious variations found. However, high pathogenicity of these strains still remained.

CONCLUSIONThe presence of variable but nonculturable-state strains suggested that the routine method of bacteria storage should be changed and more attention should be paid to realize the existence of this kind of bacteria during the routine surveillance of the communicable diseases.

Antigens, Bacterial ; Drug Resistance, Bacterial ; Enterotoxigenic Escherichia coli ; drug effects ; immunology ; pathogenicity ; Microbiological Techniques

OBJECTIVETo discuss the possible mechanism of drug resistance transmission between Staphylococcus and Escherichia coli.

METHODSThe chloramphenicol resistance plasmid of Staphylococcus aureus was extracted to transform the sensitive Escherichia coli, and the drug-resistant Escherichia coli were screened by drug sensitivity test.

RESULTSThe drug-resistant Escherichia coli were successfully obtained.

CONCLUSIONStaphylococcus may have a natural shuttle plasmid of drug resistance, which can transform Escherichia coli under specific conditions.

Drug Resistance, Bacterial ; genetics ; Escherichia coli ; drug effects ; genetics ; Plasmids ; Staphylococcus ; genetics ; Transformation, Bacterial

Acinetobacter baumannii ; drug effects ; Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Microbial Sensitivity Tests

Organic solvents are usually toxic to microorganisms for destroying the physiological functions. Recently, some studies have revealed that some bacteria are capable of living in conditions with high concentration of solvents through tolerant and adaptive mechanisms. This discovery inspires the research on adaptation and alteration of industrial bacteria, especially for those producing solvents or degrading toxic organic compounds. For a deep understanding and a wide application of the tolerant mechanisms, we address here the recent discoveries on solvents toxicity to bacteria by the parameter logP, and tolerant mechanisms of solvent-tolerant-bacteria to solvents, such as changes in cell membrane including cis-trans isomerisation, the saturated-to-unsaturated fatty acids ratio and the phospholipids head-groups, changes in outer membrane and cell morphology, and other stress responses. Moreover, our experiences in screening novel solvent-tolerant-bacteria and methods in increasing solvent tolerance of industrial microbes are introduced to give a promising strategy for improving solvent production.
Adaptation, Physiological ; drug effects ; Bacteria ; drug effects ; Drug Resistance, Bacterial ; drug effects ; Industrial Microbiology ; methods ; Organic Chemicals ; pharmacology ; Solvents ; pharmacology

INTRODUCTIONTigecycline is an antibiotic belonging to the glycylcycline class with in vitro activity against most Gram-negative bacteria, other than Pseudomonas aeruginosa. This study investigated the in vitro activity of tigecycline against multi-resistant isolates of Enterobacteriaceae and Acinetobacter spp. isolated from clinical specimens in Singapore.

MATERIALS AND METHODSMinimum inhibitory concentrations (MICs) to tigecycline were determined for 173 isolates of multi-resistant Escherichia coli, Klebsiella spp., Enterobacter spp. and Acinetobacter spp. using agar dilution.

RESULTSThe MIC required to inhibit the growth of 90% of organisms varied from 0.5 to 4 mg/L for the study isolates. Based on a resistance breakpoint of >or=8 mg/L, resistance rates varied from 0% to 9%.

CONCLUSIONSTigecycline demonstrates good in vitro activity against multi-resistant strains of Enterobacteriaceae, with more variable activity against multi-resistant strains of Acinetobacter spp.

Acinetobacter ; drug effects ; Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Enterobacteriaceae ; drug effects ; Escherichia coli ; drug effects ; Klebsiella ; drug effects ; Minocycline ; analogs & derivatives ; pharmacology ; Singapore

OBJECTIVEThis article aimed to review the incidence of Helicobacter pylori (H. pylori) infection and its therapy.

DATA SOURCESRelevant articles published in English were identified by searching in PubMed from 2000 to 2013, with keywords "H. pylori". Important references from selected articles were also retrieved from Elsevier, Wiley, EBSCO, and SPRINGER. The Chinese articles published were searched from China National Knowledge Infrastructure (CNKI).

STUDY SELECTIONArticles about "prevalence", "gastric carcinoma", "peptic ulcer", "gastroesophageal reflux disease", "functional dyspepsia", "pathogenic mechanism", "therapy", "eradication rate", "antibiotic resistance", and "gene polymorphisms" were selected.

RESULTSThe decreased infection rates of H. pylori could also be linked to the changed disease spectrum, such as the decreased morbidity and recurrence rate of H. pylori-related peptic ulcer, and the increased morbidity of gastroesophageal reflux. Although different treatment regimens have been used for H. pylori infection, the H. pylori eradication rate declined gradually. Due to primary resistance to antibiotics, the gene polymorphism of host and infected strain, and the therapy regimes, H. pylori eradication became even more difficult.

CONCLUSIONSThe prevalence of H. pylori infection had been decreasing, but the rate of eradication failure has dramatically risen in many countries due to resistance to antibiotic. H. pylori therapy in clinical practice is becoming progressively more difficult.

Drug Resistance, Bacterial ; genetics ; Helicobacter Infections ; drug therapy ; epidemiology ; Helicobacter pylori ; drug effects ; genetics ; pathogenicity ; Humans

Carbapenems ; pharmacology ; Drug Resistance, Bacterial ; Humans ; Klebsiella Infections ; drug therapy ; microbiology ; Klebsiella pneumoniae ; drug effects

Anti-Bacterial Agents ; pharmacology ; Bacterial Infections ; therapy ; Bacteriophages ; physiology ; Drug Resistance, Bacterial ; drug effects ; Humans ; Probiotics ; pharmacology ; therapeutic use