With the emergence of drug resistant tuberculosis, it is very urgent to find novel anti-tuberculosis drugs, especially novel anti-drug-resistant tuberculosis drugs. Because of the slow growth and the need to work in a biosafty environment of Mycobacterium tuberculosis, the development of evaluation of drug effect is severely impeded. In order to solve these issues, non-pathogenic fast-growing Mycobacterium smegmatis is introduced as test organism. The inhA is one of a target of isoniazid (INH) overexpression or mutation of this gene in Mycobacterium tuberculosis conferring resistant to INH. A recombinant plasmid bearing inhA was constructed and electroporated into Mycobacterium smegmatis, using shuttle expression vector pMV261. Transformants were induced to express a protein of inhA, identified by SDS-PAGE. Results show that Mycobacterium smegmatis containing inhA plasmids exhibited 100-fold or greater increased resistance to INH, but it conferred no increased resistance to others first-line anti-tuberculosis drugs. Resazurin microtiter assay plate testing of Mycobacterium smegmatis susceptibility to drugs is a rapid, simple, and inexpensive method and could decrease color background of drugs by detecting fluorescence. It will be benefit for high-throughout screening of drugs of anti-isoniazid-resistant Mycobacteria.
Anti-Bacterial Agents ; pharmacology ; Antibiotics, Antitubercular ; pharmacology ; Antitubercular Agents ; pharmacology ; Bacterial Proteins ; genetics ; metabolism ; Drug Resistance, Bacterial ; Electroporation ; Ethambutol ; pharmacology ; Isoniazid ; pharmacology ; Microbial Sensitivity Tests ; Mycobacterium smegmatis ; drug effects ; genetics ; metabolism ; Oxidoreductases ; genetics ; metabolism ; Plasmids ; Rifampin ; pharmacology ; Streptomycin ; pharmacology

OBJECTIVES: This study aimed to understand the nationwide patterns of antibiotic prescription after tooth extraction in adult patients.MATERIALS AND METHODS: This study analyzed dental records from the National Health Insurance Service–National Sample Cohort (NHIS–NSC) database on 503,725 tooth extractions performed in adults (≥19 years) during 2011–2015. Patient sex, age, household income, systemic disease (diabetes mellitus and hypertension), type of dental institution, region of dental institution, year of prescription, and type of tooth extraction procedure were considered. The antibiotic prescription rate and broad-spectrum antibiotic prescription frequency were analyzed using chi-squared tests. Factors affecting the prescription of broad-spectrum antibiotics were evaluated using multivariate logistic regression analysis.RESULTS: The rate of antibiotic prescription after tooth extraction was 81.85%. Penicillin was most commonly prescribed (45.25%), followed by penicillin with beta-lactamase inhibitors (18.76%), metronidazole (12.29%), and second- to fourth-generation cephalosporins (11.52%). The proportion of broad-spectrum antibiotics used among all prescribed antibiotics was 45.88%.CONCLUSION: The findings of this study demonstrate that the rate of antibiotic prescription after tooth extraction is higher in Korea than in other countries. Furthermore, broad-spectrum antibiotics are used more frequently, which may indicate unnecessary drug prescription, an important contributor to antibiotic resistance.
Adult ; Anti-Bacterial Agents ; beta-Lactamase Inhibitors ; Cephalosporins ; Cohort Studies ; Dental Records ; Drug Prescriptions ; Drug Resistance, Microbial ; Family Characteristics ; Humans ; Korea ; Logistic Models ; Metronidazole ; National Health Programs ; Penicillins ; Prescriptions ; Tooth Extraction ; Tooth

Multidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative pathogens, have emerged to be one of the world's greatest health threats. However, not only have recent decades shown a steady decline in the number of approved antimicrobial agents but a disappointing discovery also void. The development of novel antibiotics to treat MDR Gram-negative bacteria has been stagnated over the last half century. Though few compounds have shown activities in vitro, in animal models or even in clinical studies, the global antibiotic pipeline is not encouraging. There are a plethora of unexpected challenges that may arise and cannot always be solved to cause promising drugs to fail. This review intends to summarize recent research and development activities to meet the inevitable challenge in restricting the proliferation of MDR Gram-negative bacteria, with focus on compounds that have entered into clinical development stage. In addition to new analogues of existing antibiotic molecules, attention is also directed to alternative strategies to develop antibacterial agents with novel mechanisms of action.
Aminoglycosides ; pharmacology ; therapeutic use ; Animals ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Antibodies, Monoclonal ; pharmacology ; therapeutic use ; Drug Discovery ; Drug Resistance, Multiple, Bacterial ; Enzyme Inhibitors ; pharmacology ; therapeutic use ; Ferrous Compounds ; pharmacology ; therapeutic use ; Gram-Negative Bacteria ; drug effects ; Gram-Negative Bacterial Infections ; drug therapy ; Humans ; Peptides ; pharmacology ; therapeutic use ; Peptidomimetics ; pharmacology ; therapeutic use ; Tetracyclines ; pharmacology ; therapeutic use ; beta-Lactamase Inhibitors ; beta-Lactams ; pharmacology ; therapeutic use

INTRODUCTION: This study aimed to determine the in vitro susceptibility of standard isolates of common pathogens causing bacterial conjunctivitis to non-fluoroquinolone antimicrobial ophthalmic medications. METHODS: This is a single-blind experimental study which compared the in vitro susceptibility of Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa and Staphylococcus epidermidis to locally available non-fluoroquinolone ophthalmic medications, specifically chloramphenicol, tobramycin, fusidic acid, gentamicin sulfate, sulfacetamide and polymyxin-neomycin. Utilizing the disk diffusion method, zones of inhibition in millimeters for each bacterial isolate was recorded and tabulated. Kruskal-Wallis test was used to determine statistical differences. RESULTS: Both Staphylococci were sensitive to all antibiotics except sulfacetamide. Only chloramphenicol showed activity against all four isolates. Tobramycin showed the largest zone of inhibition against Pseudomonas aeruginosa. There was statistically significant difference in the median zone of inhibition in each antimicrobial medication against Staphylococcus aureus (p = 0.002) and Staphylococcus epidermidis (p < 0.001) with the largest mean zone of inhibition by fusidic acid of 34 and 38 millimeters, respectively. Streptococcus pneumoniae was least susceptible to antibiotics tested; only chloramphenicol and fusidic acid showed activity. There were also significant differences in the median zones of inhibition across the isolates. CONCLUSION The standard isolates are susceptible to at least one non-fluoroquinolone ophthalmic medication. The antibiotics tested showed differences in activity against the four isolates. The findings of this study may be used as a basis to review local practice patterns or/and initiate revisions in the guidelines for prescribing initial treatment of bacterial conjunctivitis.
Conjunctivitis, Bacterial ; Anti-Bacterial Agents

No abstract available.
Anti-Bacterial Agents

No abstract available.
Anti-Bacterial Agents* ; Appendicitis*

No abstract available.
Anti-Bacterial Agents* ; Appendicitis*

No abstract available.
Anti-Bacterial Agents*

No abstract available.
Anti-Bacterial Agents*

No abstract available.
Anti-Bacterial Agents ; Diarrhea*