The discovery of antibiotics is a big revolution in human history, and its clinical application has saved countless lives. However, with the widespread and abuse of antibiotics, many pathogens have developed resistance, and even "Super Bacteria" resistance to multiple drugs have evolved. In the arms race between humans and pathogens, humans are about to face a situation where no medicine is available. Research on microbial antibiotic resistance genes, resistance mechanisms, and the spread of resistance has attracted the attention of many scientific researchers, and various antibiotic resistance gene databases and analysis tools have emerged. In this review, we collect the current databases that focus on antibiotics resistance genes, and discuss these databases in terms of database types, data characteristics, antibiotics resistance gene prediction models and the types of analyzable sequences. In addition, a few gene databases of anti-metal ions and anti-biocides are also involved. It is believed that this summary will provide a reference for how to select and use antibiotic resistance gene databases.
Anti-Bacterial Agents/pharmacology* ; Bacterial Infections ; Drug Resistance, Bacterial/genetics* ; Drug Resistance, Microbial/genetics* ; Humans ; Metals

To understand the genetic diversity and drug resistance status of Mycobacterium tuberculosis (M. tuberculosis) circulating in Xuzhou of China, the spacer-oligonucleotide typing (Spoligotyping) and multi-loci VNTRs (variable number tandem repeats) analysis (MLVA) were utilized for the genotyping of the isolates. Drug susceptibility test (DST) was performed by the proportion method on the Lowenstein-Jensen (L-J) medium using isoniazid, rifampicin, ethambutol, and streptomycin. By Spoligotyping, 287 M. tuberculosis isolates were differentiated into 14 clusters. Then with 15-loci MLVA, these strains could be divided into 32 clusters, 228 genotypes. Of 15 VNTRs, 6 loci had the highly discriminatory powers, 6 loci presented moderate discrimination and 3 loci demonstrated less polymorphism. The DST results showed that 46 strains were resistant to at least one first-line anti-tuberculosis agent. There was a difference in the isoniazid resistance between Beijing and non-Beijing genotype strains. We concluded that the combination of Spoligotyping and 15 VNTR loci as the genotyping in our study was applicable for this region, the drug resistant isolates were identified, and the Beijing family was the most prevalent genotype in the rural counties of Xuzhou.
China ; Drug Resistance, Bacterial ; genetics ; Genotyping Techniques ; Mycobacterium tuberculosis ; genetics

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

Bacterial multi-drug resistance (MDR) is a global challenge in the fields of medicine and health, agriculture and fishery, ecology and environment. The cross-region spread of antibiotic resistance genes (ARGs) among different species is one of the main cause of bacterial MDR. However, there is no effective strategies for addressing the intensifying bacterial MDR. The CRISPR-Cas system, consisting of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR associated proteins, can targetedly degrade exogenous nucleic acids, thus exhibiting high application potential in preventing and controlling bacterial MDR caused by ARGs. This review briefly introduced the working mechanism of CRISPR-Cas systems, followed by discussing recent advances in reducing ARGs by CRISPR-Cas systems delivered through mediators (e.g. plasmids, bacteriophages and nanoparticle). Moreover, the trends of this research field were envisioned, providing a new perspective on preventing and controlling MDR.
Anti-Bacterial Agents ; Bacteriophages/genetics* ; CRISPR-Cas Systems ; Drug Resistance, Bacterial/genetics* ; Plasmids/genetics*

Anti-Bacterial Agents ; Clostridium Infections ; diagnosis ; microbiology ; Clostridium difficile ; genetics ; Drug Resistance, Bacterial ; genetics ; Humans

Objective: To understand the antimicrobial resistance and genome characteristics of Campylobacter isolates recovered from retailed poultry meat samples in 20 provinces in China in 2020. Methods: In 2020, 265 Campylobacter strains including 244 Campylobacter jejuni and 21 Campylobacter coli collected from retailed poultry meat samples in China were tested for antimicrobial resistance to 9 antimicrobial compounds by using the agar dilution method. Forty-two selected isolates were sent for whole genome sequencing and 38 high-quality genomes were analyzed for their antimicrobial resistance genes, virulence genes, sequence types and genetic diversity. Results: The resistance rates of Campylobacter isolates from poultry meats to tetracycline, nalidixic acid and ciprofloxacin were the highest (84%-100%), with 53.2% of the isolates showing multidrug resistance in this study. The resistance rates of C. coli to erythromycin, azithromycin, telithromycin, gentamicin and clindamycin were significantly higher than those of C. jejuni (P<0.05). The resistance genes conferring resistance to β-lactams (100%, 38/38), quinolones (94.7%, 36/38), tetracycline (81.6%, 31/38) and aminoglycosides (50%, 19/38) were the most frequently detected among 38 Campylobacter genomes. C. jejuni carried more virulence genes than C. coli. In total, 19 and 17 sequence types (ST) were obtained from 20 sequenced C. jejuni and 18 C. coli isolates, respectively, including 5 novel STs. The isolates showed a high genetic diversity based on their sequence types. Conclusion: The phenomenon of antimicrobial resistance in Campylobacter from poultry meat sources in China is relatively serious, and resistance and virulence genes are widely distributed in Campylobacter. There is genetic diversity in Campylobacter.
Humans ; Animals ; Anti-Bacterial Agents/pharmacology* ; Campylobacter/genetics* ; Poultry ; Drug Resistance, Bacterial/genetics* ; Genomics ; China ; Tetracycline

Objective: To understand the antimicrobial resistance and genome characteristics of Campylobacter isolates recovered from retailed poultry meat samples in 20 provinces in China in 2020. Methods: In 2020, 265 Campylobacter strains including 244 Campylobacter jejuni and 21 Campylobacter coli collected from retailed poultry meat samples in China were tested for antimicrobial resistance to 9 antimicrobial compounds by using the agar dilution method. Forty-two selected isolates were sent for whole genome sequencing and 38 high-quality genomes were analyzed for their antimicrobial resistance genes, virulence genes, sequence types and genetic diversity. Results: The resistance rates of Campylobacter isolates from poultry meats to tetracycline, nalidixic acid and ciprofloxacin were the highest (84%-100%), with 53.2% of the isolates showing multidrug resistance in this study. The resistance rates of C. coli to erythromycin, azithromycin, telithromycin, gentamicin and clindamycin were significantly higher than those of C. jejuni (P<0.05). The resistance genes conferring resistance to β-lactams (100%, 38/38), quinolones (94.7%, 36/38), tetracycline (81.6%, 31/38) and aminoglycosides (50%, 19/38) were the most frequently detected among 38 Campylobacter genomes. C. jejuni carried more virulence genes than C. coli. In total, 19 and 17 sequence types (ST) were obtained from 20 sequenced C. jejuni and 18 C. coli isolates, respectively, including 5 novel STs. The isolates showed a high genetic diversity based on their sequence types. Conclusion: The phenomenon of antimicrobial resistance in Campylobacter from poultry meat sources in China is relatively serious, and resistance and virulence genes are widely distributed in Campylobacter. There is genetic diversity in Campylobacter.
Humans ; Animals ; Anti-Bacterial Agents/pharmacology* ; Campylobacter/genetics* ; Poultry ; Drug Resistance, Bacterial/genetics* ; Genomics ; China ; Tetracycline

OBJECTIVETo investigate the homology and resistant mechanism of vancomycin-resistant Enterococci (VRE) isolates.

METHODSA total of 9 VRE isolates were collected from 2006 to 2007 at PUMC hospital. The susceptibility of these isolates to 10 different antibiotics including vancomycin was tested by E-test. These strains were processed by brain heart infusion agar screening in the presence of vancomycin (6 microg/ml), and were analyzed for genotypic characteristics using the multiplex PCR. The homology of the isolates was determined by pulsed-field gel electrophoresis (PFGE).

RESULTSAll the 9 VRE isolates were identified as Enterococci faecium. The visual analysis of PFGE patterns revealed 6 different PFGE types. The vanA gene was confirmed by PCR and sequencing in 9 VRE isolates, which were consistent between phenotype and genotype for glycopeptides resistance.

CONCLUSIONSOnly vanA genotype was detected in PUMC hospital. Clonal dissemination, horizontal gene transfer, and the selective pressure of antimicrobial agents may contribute to the increase of VRE.

Bacterial Proteins ; genetics ; Bacterial Typing Techniques ; Drug Resistance, Multiple, Bacterial ; Enterococcus faecium ; classification ; drug effects ; genetics ; isolation & purification ; Gram-Positive Bacterial Infections ; microbiology ; Humans ; Vancomycin Resistance

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

OBJECTIVETo investigate the drug resistance of enteric bacilli and its relation to the drug resistance gene cassette in the variable region and molecular evolution of class-I integron.

METHODSK-B assay was applied to measure the drug resistance of E.coli, E.cloacae and A.baumannii isolated against twelve antibiotics. The class-I integron and drug resistance gene cassettes in the variable region of the integron were detected by PCR and sequencing of amplification products. The molecular evolution of drug resistance genes in the class-I integrons was analyzed using Clustal X and MEGA software.

RESULTS54.2%-100% of A.baumannii isolates were resistant to the penicillin and cephem antibiotics, while E.coli and E.cloacae isolates had resistance rates of 41.6%-62.5% to cephem antibiotics. 62.5%(15/24) of E.coli, 67.9%(19/28) of E.cloacae and 83.3%(20/24) of A.baumannii isolates were positive for class-I integrons. 81.5% (44/54) of class-I integrons showed 4 different single band spectrums and the other class-I integrons displayed 3 different double band spectrums. In the drug resistance gene cassettes in variable regions of class-I integrons there were 7 types in 4 groups of drug resistance genes, including aac(6'), sad(3"), aad(2"), cat(4') and dfr (types 7, A13 and 15), which induced the resistance to aminoglycosides and sulfamido antibiotics and chloromycin. The class-I integrons in the isolates might be divided into 4 molecular evolution groups according to the diversity of dihydrofolate reductase encoding gene sequences.

CONCLUSIONThe enteric bacilli have a high drug resistance and frequently carry class-I integrons with 7 drug resistance gene cassettes which present 4 different evolutionary pathways.

Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Multiple, Bacterial ; genetics ; Enterobacteriaceae ; drug effects ; genetics ; Evolution, Molecular ; Integrons ; genetics