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Antimicrobial resistance is one of the critical public health issues in the world. There is an urgent need to develop effective broad-spectrum antibiotics to treat the infection of multi-drug resistant Gram-negative bacilli. Cefiderocol, developed by the Shionogi Inc. in Japan, is a new type of iron carrier cephalosporin antibiotics, which overcomes the drug resistance of Gram-negative bacilli due to the down-regulation of outer membrane pore protein and the up-regulation of efflux pump, and has good stability to serine- and metallo-carbapenemases. This drug has a broad spectrum and strong antibacterial activity against carbapenem-resistant Enterobacteriaceae (CRE), Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. Cefiderocol can be used to treat complex urinary tract infections (including pyelonephritis), hospital-acquired pneumonia, and ventilator-associated pneumonia. By summarizing the chemical structure, antibacterial mechanism, in vitro antibacterial activity, pharmacokinetics, pharmacodynamics, and clinical treatment of cefiderocol, this review shows the application potential of cefiderocol as a new iron carrier cephalosporin in the treatment of multi-drug resistant Gram-negative bacilli infections.
Subject(s)
Cephalosporins/therapeutic use , Gram-Negative Bacteria , Microbial Sensitivity Tests , Siderophores/pharmacologyABSTRACT
Objective:To investigate the in vitro antibacterial effects of imipenem combined with common antibiotics on bla KPC-2 type carbapenem resistant klebsiella pneumoniae (CRKP) targeting bla KPC-2 gene. Methods:Six strains of unrepeated bla KPC-2 type confirmed by polymerase chain reaction and DNA sequence were isolated in Yueqing People's Hospital, China between January 2018 and January 2019 were included in this study. The susceptibility rate of imipenem against nine conventionally used antibiotics was determined. The sensitivity test of imipenem combined with eight antibiotics was performed with the checkerboard method. Fractional inhibitory concentration was calculated to assess the efficacy of imipenem combined with common antibiotics. The in vitro treatment time-antibacterial effect curve was drawn to evaluate the antibacterial effects. Results:The resistance rate of six strains of bla KPC-2 type was 100.00% (6/6) for imipenem, meropenem, ceftazidime, ciprofloxacin, rifampicin and cefotaxime, and it was 66.67% (4/6) for minocycline and clavulanic acid and 33.33% (2/6) for tigecycline. Imipenem combined with tigecycline had a better antibacterial effect and exhibited a synergistic effect on four strains of bla KPC-2 type CRKP and an additive effect on two strains of Bla KPC-2 type CRKP. The curve of time for in vitro treatment of KPN2 with imipenem combined with tigecycline against bactericidal effect revealed that the antibacterial rate of imipenem at the 1/2 minimum inhibitory concentration combined with tigecycline at the 1/4 minimum inhibitory concentration was > 95% at (t+2) and the antibacterial effect could maintain (t+10) hours to (t+12) hours. The antibacterial rate of imipenem combined with tigecycline against strain 002 was gradually decreased with time, and the growth curve of strain 002 rised gradually. Conclusion:In vitro drug sensitivity test revealed that imipenem combined with tigecycline exhibits a good synergistic effect on bla KPC-2 type CRKP. Findings from this study provide a reference for clinical treatment of bla KPC-2 type CRKP.
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Aim: To analyze the antibacterial effects of 95% ethanol extract of chicory roots and stems from Xinjiang on Staphylococcus aureus and Enterococcus faecalis, and provide reference data for identifying the better antibacterial efficacy parts of chicory. Methods: The diameters of the inhibition zone of roots and stem extracts were determined by the Oxford Cup method; the minimum inhibitory concentrations (MIC) of roots and stem extracts on the bacteria were determined by the half - dilution method; the roots and stem extracts to observe the effects on bacterial proliferation were determined by the growth curve method; and the concentration of alkaline phosphatase (AKP) in bacterial extracellular solution enzyme was determined by labeling method. Results: The 95% ethanol extract of chicory roots and stems had significant inhibitory effects on the growth of Staphylococcus aureus and Enterococcus faecalis. Chicory roots' minimum inhibitory concentration to both bacteria was 64 g · L-1, and the minimum inhibitory concentration of chicory stems to both bacteria was 50g· L-1,64g· L-1, respectively. And the 95% ethanol extract of chicory stems had better inhibitory effect on Staphylococcus aureus, while the 95% ethanol extract of chicory roots had better inhibitory effect on Enterococcus faecalis; the ethyl acetate extract of chicory roots had better antibacterial effect on both bacteria than extract of 95% ethanol did (P <0. 01). Conclusions: The 95% ethanol extract of chicory roots and stems can significantly inhibit the proliferation of both bacteria, and the inhibitory effect of chicory stems on Staphylococcus aureus is more obvious, and the inhibitory effect of chicory roots on Enterococcus faecalis is better; the best antibacterial effect of chicory roots is ethyl acetate extraction.
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Objective@#To investigate the in vitro antibacterial activity of triclosan combined with different antibacterial agents against triclosan-resistant multidrug-resistant Acinetobacter baumannii (A.baumannii).@*Methods@#A total of 626 A. baumannii strains were collected from the First Affiliated Hospital of Wenzhou Medical University from 2016 to 2017. The sensitivity of these A. baumannii strains to common antibiotics was detected by VITEK 2-compact automatical microbiological analyzer and the minimum inhibitory concentrations (MIC) of triclosan were detected by agar dilution method. Checkerboard method was used to detect the changes in MIC values of triclosan against 16 triclosan-resistant multidrug-resistant A. baumannii strains after it was used in combination with four external ointments, including gentamicin, erythromycin, chloramphenicol and kanamycin, and three common antibiotics of imipenem, meropenem and ciprofloxacin, respectively. Fractional inhibitory concentration index (FICI) was used to evaluate the joint bacteriostatic effects.@*Results@#Among the 626 A. baumannii strains, 17 were resistant to triclosan with a drug resistance rate of 2.7% (17/626). These triclosan-resistant strains had high MIC values for ciprofloxacin, imipenem, ceftazidime and other commonly used clinical antibiotic and most of them were multidrug-resistant. After triclosan was used in combination with seven different antibacterial drugs, the MIC values of all drugs decreased to various degrees compared with those when they were used alone. Triclosan in combination with gentamicin, chloramphenicol and ciprofloxacin showed synergistic effects on 62.5%, 56.25% and 62.5% of the 16 strains and additive effects on 37.5%, 43.75% and 37.5%, respectively. When it was used in combination with erythromycin, kanamycin, imipenem and meropenem, synergistic effects on 37.5%, 25%, 12.5% and 12.5%, additive effects on 37.5%, 56.25%, 62.5% and 62.5%, and indifferent effects on 25%, 18.75%, 25% and 25% of the strains were detected, respectively. No antagonistic effect was found between triclosan and any of the above antibiotics.@*Conclusions@#Triclosan combined with gentamicin, chloramphenicol and ciprofloxacin had better in vitro antibacterial effects against the triclosan-resistant multidrug-resistant A. baumannii strains in this study with synergistic and additive effects. Some indifferent effects were found between triclosan and kanamycin, erythromycin, imipenem and meropenem, but no antagonistic effects were detected.
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Objective To investigate the in vitro antibacterial activity of triclosan combined with different antibacterial agents against triclosan-resistant multidrug-resistant Acinetobacter baumannii ( A. bau-mannii) . Methods A total of 626 A. baumannii strains were collected from the First Affiliated Hospital of Wenzhou Medical University from 2016 to 2017. The sensitivity of these A. baumannii strains to common an-tibiotics was detected by VITEK 2-compact automatical microbiological analyzer and the minimum inhibitory concentrations ( MIC) of triclosan were detected by agar dilution method. Checkerboard method was used to detect the changes in MIC values of triclosan against 16 triclosan-resistant multidrug-resistant A. baumannii strains after it was used in combination with four external ointments, including gentamicin, erythromycin, chloramphenicol and kanamycin, and three common antibiotics of imipenem, meropenem and ciprofloxacin, respectively. Fractional inhibitory concentration index ( FICI) was used to evaluate the joint bacteriostatic effects. Results Among the 626 A. baumannii strains, 17 were resistant to triclosan with a drug resistance rate of 2. 7％ (17/626). These triclosan-resistant strains had high MIC values for ciprofloxacin, imipenem,ceftazidime and other commonly used clinical antibiotic and most of them were multidrug-resistant. After tri-closan was used in combination with seven different antibacterial drugs, the MIC values of all drugs de-creased to various degrees compared with those when they were used alone. Triclosan in combination with gentamicin, chloramphenicol and ciprofloxacin showed synergistic effects on 62. 5％, 56. 25％ and 62. 5％of the 16 strains and additive effects on 37. 5％, 43. 75％ and 37. 5％, respectively. When it was used in combination with erythromycin, kanamycin, imipenem and meropenem, synergistic effects on 37. 5％, 25％, 12. 5％ and 12. 5％, additive effects on 37. 5％, 56. 25％, 62. 5％ and 62. 5％, and indifferent effects on 25％, 18. 75％, 25％ and 25％ of the strains were detected, respectively. No antagonistic effect was found between triclosan and any of the above antibiotics. Conclusions Triclosan combined with genta-micin, chloramphenicol and ciprofloxacin had better in vitro antibacterial effects against the triclosan-resist-ant multidrug-resistant A. baumannii strains in this study with synergistic and additive effects. Some indiffer-ent effects were found between triclosan and kanamycin, erythromycin, imipenem and meropenem, but no antagonistic effects were detected.
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Objective:To study the in vitro bacteriostasis of water extract of humulus. Methods:By using double dilution method and 96-well plates trace broth dilution method, the inhibitory test of water extract of humulus was conducted on Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The minimum inhibitory concentration ( MIC ) , minimum bactericidal concentration ( MBC) and the diameter of inhibition zone were determined. Results: The drug showed different sensitive degree on the test strains. MIC and MBC for Escherichia coli were 31. 25 mg·ml-1 , that for Staphylococcus aureus were 3. 91 mg·ml-1 , and that for Pseudo-monas aeruginosa was 125 and 250 mg·ml-1 . Conclusion:With the water extract of humulus as the research object, the study on the in vitro bacteriostasis effect of humulus scandens is closer to the clinical application form, which provides reference for the further re-search on the related preparation of humulus scandens.
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Objective To evaluate the inhibitory activity of Herba Taraxaci extract on Escherichia coli DH5α (E. coli DH5α) and to investigate proteomic response of E. coli. Methods Medicinal powder of Herba Taraxaci was extracted with the solvents of different polarity ( n-hexane, ethyl acetate, distilled water) , and then the obtained 8 different extracts were subjected to thin layer chromatography ( TLC) analysis. Microdilution method was performed to detect the minimum inhibitory concentration ( MIC) of different extracts and the growth curves were described. The protein expression profiles of E . coli treated with the extracts were analyzed by sodium dodecyl sulfate polyacrylamide gel electropheresis ( SDS-PAGE) and two dimensional electrophoresis (2-DE) . Results Water decoction of Herba Taraxaci could obviously suppress the growth of E. coli with a MIC of 1.95 mg/mL. The different extractions exhibited no antibacterial activity except ethyl acetate phase 3 with a MIC of 0.13 mg/mL, which was equal to 19.23 mg/mL of crude drugs. The results of TLC analysis showed that chlorogenic acid was undetectable in n-hexane extract and ethyl acetate phase 1 extract, and ethyl acetate phase 2 and 3 extracts showed obviously increased spots. The results of SDS-PAGE and 2-DE showed that water decoction of Herba Taraxaci had inhibitory effect on the expression of functional protein. The results of 2-DE showed that after treatment with ethyl acetate phase 3 at the concentration of 2 × MIC for 21 hours, the amount of protein spots were 92 less than those of the blank control group, the spots of E. coli DH5α soluble protein with expression amount down-regulated doubly were 24, and those with expression amount up-regulated doubly were 19. Ethyl acetate phase 3 extract had an effect on down-regulating the protein expression of E. coli DH5α soluble protein pH3-10, and water decoction of Herba Taraxaci had inhibitory effect on E. coli DH5αprotein expression. Conclusion Herba Taraxaci has significant antibacterial activity on E. coli DH5α, and the water-soluble fraction of chlorogenic acid and caffeic acid might be the active components. The possible antibacterial mechanism may be related with the regulation of bacterial protein expression.
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Objective To measure the in vitro antibacterial activity of tigecycline against carbapenems-resistant Acinetobacter calcoacetcus-Acinetobacter baumannii complex.Methods The isolated strains of carbapenems-resistant Acinetobacter calcoacetcus-Acinetobacter baumannii complex were collected in our hospital from December 2013 to February 2014.The MIC test strip was a-dopted to measure the MIC value of tigecycline.The break point adopted the judgment criteria published by FDA.Results All 61 strains of carbapenems-resistant Acinetobacter calcoacetcus-Acinetobacter baumannii complex had extremely high drug resistant rate to the commonly used antimicrobial agents.The sensitive rate of tigecycline was 80.3%,intermediation was 19.7% and no re-sistant strain was found in this study.MIC50 and MIC90 were 2 μg/mL and 3 μg/mL respectively.Conclusion Tigecycline has bet-ter in vitro antibacterial activity to the carbapenems-resistant Acinetobacter calcoacetcus-Acinetobacter baumannii complex isolated in our hospital.
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<p><b>OBJECTIVE</b>To assess the in-vitro antibacterial activity and anti-inflammatory activity of orally administered different extracts (Hydro-alcoholic, methanolic, ethyl acetate and hexane) of Rauvolfia tetraphylla (R. tetraphylla) root bark in Carrageenan induced acute inflammation in rats.</p><p><b>METHODS</b>In-vitro antibacterial activity was evaluated for extracts against four Gram positive and four Gram negative bacteria by using cylinder plate assay. Hydro-alcoholic extract (70% v/v ethanol) at 200, 400 and 800 mg/kg doses and methanolic, ethyl acetate and hexane extracts at doses 100, 200 and 400 mg/kg were tested for anti-inflammatory activity in Carrageenan induced rat paw oedema model and paw thickness was measured every one hour up to 6 hrs.</p><p><b>RESULTS</b>All extracts of R. tetraphylla root bark showed good zone of inhibition against tested bacterial strains. In Carrageenan induced inflammation model, hydro-alcoholic and methanolic extract of R. tetraphylla root bark at three different doses produced significant (P<0.001) reduction when compared to vehicle treated control group and hexane, ethyl acetate extracts.</p><p><b>CONCLUSIONS</b>In the present study extracts of R. tetraphylla root bark shows good in-vitro antibacterial activity and in-vivo anti-inflammatory activity in rats.</p>
Subject(s)
Animals , Female , Male , Rats , Anti-Bacterial Agents , Pharmacology , Anti-Inflammatory Agents , Pharmacology , Bacteria , Carrageenan , Disease Models, Animal , Edema , Drug Therapy , Microbial Sensitivity Tests , Plant Bark , Chemistry , Plant Extracts , Pharmacology , Plant Roots , Chemistry , Rauwolfia , ChemistryABSTRACT
To assess the in-vitro antibacterial activity and anti-inflammatory activity of orally administered different extracts (Hydro-alcoholic, methanolic, ethyl acetate and hexane) of Rauvolfia tetraphylla (R. tetraphylla) root bark in Carrageenan induced acute inflammation in rats. Methods: In-vitro antibacterial activity was evaluated for extracts against four Gram positive and four Gram negative bacteria by using cylinder plate assay. Hydro-alcoholic extract (70% v/v ethanol) at 200, 400 and 800 mg/kg doses and methanolic, ethyl acetate and hexane extracts at doses 100, 200 and 400 mg/kg were tested for anti-inflammatory activity in Carrageenan induced rat paw oedema model and paw thickness was measured every one hour up to 6 hrs. Results: All extracts of R. tetraphylla root bark showed good zone of inhibition against tested bacterial strains. In Carrageenan induced inflammation model, hydro-alcoholic and methanolic extract of R. tetraphylla root bark at three different doses produced significant (P<0.001) reduction when compared to vehicle treated control group and hexane, ethyl acetate extracts. Conclusions:In the present study extracts of R. tetraphylla root bark shows good in-vitro antibacterial activity and in-vivo anti-inflammatory activity in rats.
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OBJECTIVE:To eualuate in vitro antibacterial activities of silver nitrate and povidone-iodine for preventing ophthalmia neonatorum. METHODS:Minimal inhibitory concentration(MIC) and mininmal bactericidal concentration (MBC) were deter-mined by double broth dilution method. RESULTS:For Stapanrens Streppnenmonia and N gonorhveae,the MIC50 of silver nitrate were＜4～8μg.ml－1 and its MIC90 were 8～32μg.ml－1.The MIC50 of povidone-iodine were64～256μg.ml－1 and its MBC90were 512 μg.ml-1. CONCLUSION: Silver nitrate and povidone-iodine exhibited activities against common pathogens of ophthalmia neonatorum isolates.Silver nitrate was more active than povidone-iodine.
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Objective To evaluate the in- vitro antibacterial activity of e thanol- extract of Galla Chinensis against Staphycoccus aureus (S. aureus).Meth ods The minimum inhibitory concentration (MIC50) of ethanol- extract of Galla Chinensis against 112 strains of S. aureus was detected by using agar dilution method.Results The MIC50 and MIC90 of ethanol- extract of Galla Chinensis aga inst 84 strains of MRSA (methicillin- resistant staphylococcus aureus) were 0. 315, 0.315 mg/mL, and those against 28 strains MSSA (methicillin- sensitive sta phylococcus aureus) were 0.63 and 0.315 mg/mL respectively.Conclusion Ethanol - extract of Galla Chinensis has a strong antibacterial activity against S.aure us.
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OBJECTIVE:Using in vitro studies,we evaluated the antibacterial activity of amoxicillin/tazobactam against 128 strains of pathogens isolated from patients and compared with amoxicillin/clavulanic acid and amoxicillin/sulbactam.METHODS:To detect the minimum inhibitory concentrations (MIC)of four ?-lactams against 128 clinically isolated strains with agar dilution method.RESULTS:The results indicated that the in vitro antibacterial activity of amoxicillin/tazobactam(2∶1) was the best.The MIC50 of amoxicillin/tazobactam(2∶1) is 1/4～1/8 times than those of amoxicillin/sulbutam and amoxicillin/clavulanic acid.The MIC90 of amoxicillin/tazobactam(2∶1) was 1/2～1/4 of those of amoxicillin/sulbutam and amoxicillin/clavulanic acid.The combination ratio 2∶1(amoxicillin/tazobactam)of the two compounds was more suitable than other combination ratios(4∶1 and 8∶1)for inactivating ?-lactamase.CONCLUSION:The in vitro antibacterial activities of amoxicillin/tazobactam(2∶1) against MRSA,MRSE,MSSA and E.coli are high.It showed that amoxicillin/tazobactam(2∶1)is stable to ?-lactamase and is an effective bactericidal agent.
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Objective: To study in vitro antibacterial activity of faropenem.Methods: The minimum inhibitory concentration(MIC) of faropenem,cefoperazone/sulbactam or cefotaxime against 194 clinical isolates was determined by agar dilution method.MIC50,MIC90 and the susceptible rate were counted.Results: MIC50 and MIC90 of faropenem were lower than or equal to 1?g/ml and 4?g/ml for all 194 clinical isolates respectively.All susceptible rates of faropenem were more than 90%.MIC90 of faropenem was similar to that of cefoperazone/sulbactam against beta-lactamase producing Escherichia coli and klebsierlla peumoniae,but was 1/32 MIC90 of cefotaxime.MIC90 of three antibiotics was similar against Proteus spp,Moraxella catarrhalis and Streptococcus pneumoniae.MIC90 of faropenem was marked lower than that of cefoperazone/sulbactam or cefotaxime against Staphylococcus aureus,Staphylococcus epidermidis and Enterococcus faecalis.Conclusion: Antibacterial activity of faropenem against clinical isolates is very strong and it is also strongly against beta-lactamase producing bacteria.It can be expected that faropenem will be used widely in clinic in china.
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Object:To study in vitro antibacterial activity of prulifloxacin against pathogenic bacteria of respiratory tract and urinary tract infections.Methods:The minimum inhibitory concentration(MIC) of prulifloxacin and levofloxacin against 221 pathogenic bacteria of respiratory tract and urinary tract infections was determined by agar dilution method.Results:MIC50,MIC90 and the susceptible rate of prulifloxacin were≤0.03~1?g/ml,0.5~4?g/ml and 67%~100%,respectively.Those of levofloxacin were 0.125~2?g/ml,0.5~8?g/ml and 61%~100%,respectively.MIC90 of prulifloxacin was half that of levofloxacin against Escherichia coli,Enterobacter cloacae,Pseudomonas aeruginosa and Moraxella catarrhalis.MIC90 of prulifloxacin was equal to that of levofloxacin against Klebsiella pneumoniae,Proteus spp,Staphlococcus epidermidis,Streptococcus pneumoniae and Enterococus faecalis.MIC90 of prulifloxacin was two times that of levofloxacin against Haemophilus influenzae and Staphylococcus aureus.Conclusion:Prulifloxacin had a broad-spectrum antibacterial activity against pathogenic bacteria of respiratory tract and urinary tract infections.