Real-world evidence (RWE) is clinical evidence on a medical product’s safety and efficacy that is generated using real-world data (RWD) resulting from routine healthcare delivery. This study evaluates the clinical ef...Real-world evidence (RWE) is clinical evidence on a medical product’s safety and efficacy that is generated using real-world data (RWD) resulting from routine healthcare delivery. This study evaluates the clinical efficacy of amoxicillin + clavulanic acid in children with pharyngitis, acute otitis, or acute rhinosinusitis with suspected bacterial origin under normal office and home conditions. Methods: This was a real-life, prospective, observational, pharmacovigilance study. It included children of both sexes between 2 and 12 years old, with a diagnosis of Rhinopharyngitis (tonsillitis), Acute Otitis Media and Rhinosinusitis. The main effectiveness variable evaluated was reduction and time to resolution of symptoms. All patients received Amoxicillin/Clavulanic Acid suspension 600 mg/42.9 mg/5 mL at a dose of 90 mg/Kg/day in two doses, every 12 hours for 7 days. The evaluations were carried out at the beginning, at 72 hours (3rd day) and at 7 days. All patients underwent culture and antibiogram. Results: The majority of cultures were negative for pathogenic germs, suspecting unidentifiable germs, or viral etiology despite the rigorous selection of subjects following validated scores. The most frequently isolated germ was Staphylococcus aureus;growth of gram-negative bacteria was reported in 33.33% of the cultures. There was a significant improvement in symptoms in children with tonsillitis and rhinosinusitis from the first 72 hours of treatment, persisting until the 7 days. In the otitis media group, returning to normal by the tenth day. During the conduction of this investigation, no adverse effects associated with the prescribed therapy were reported.展开更多
Introduction: The efficacy of amoxicillin combined with clavulanic acid in Acute Otitis Media (AOM) is not debatable, but studies report a high frequency of gastrointestinal adverse effects related to this interventio...Introduction: The efficacy of amoxicillin combined with clavulanic acid in Acute Otitis Media (AOM) is not debatable, but studies report a high frequency of gastrointestinal adverse effects related to this intervention. In this scenario, several studies about the antibiotic cefprozil report that it has the same efficacy as amoxicillin/clavulanate for the treatment of AOM with significantly fewer side effects. The aim of our study was to compare the efficacy and safety of both treatments in AOM. Methodology: We searched for clinical trials and systematic reviews with or without meta-analyses in the Cochrane Group Register and the MEDLINE database up to November 2013, comparing the two interventions mentioned. Results were expressed as a rate of treatment failures or favorable response rates (clinical and microbiological in both cases), and as the rate of adverse events. The analysis was carried out considering the fixed and random effects models. The significance level used in the test for heterogeneity was 0.05. Funnel plot was used to search for publication bias. Results: 7 clinical trials were included in the analysis and no significant difference was found for both interventions regarding clinical and bacteriological response (RR = 1.02, 95% CI, 0.97-1.06, p = 0.780 and RR = 1.02, 95% CI, 0.99-1.07, p = 0.228, respectively). However, a significant difference was found in the comparison of adverse effects, showing that amoxicillin/clavulanate has a significantly higher risk of developing side effects than cefprozil (RR = 0.52, 95% CI, 0.45-0.59, p = 0.000). Conclusion: Both treatments demonstrated equal clinical and microbiological efficacy. However, the use of cefprozil is significantly associated with a lower risk of adverse effects.展开更多
To study the bioequivalence of Clavulanate Potassium and Amoxicillin (1:7) dispersible tablets, a randomized cross over study was conducted in 18 healthy volunteers. A single oral dose of 1000 mg Clav ulanate Pot...To study the bioequivalence of Clavulanate Potassium and Amoxicillin (1:7) dispersible tablets, a randomized cross over study was conducted in 18 healthy volunteers. A single oral dose of 1000 mg Clav ulanate Potassium and Amoxicillin (1:7) dispersible tablets (Tested formulation, T) or Augmentin syrup (Reference formulation, R). Concentrations in plasma were determined with high performance liquid chromatography. The main paramaters of T were: for Clavulanate Potassium and Amoxicillin, C max : 2.46±1.11 μg/m l and 18.81±7.26 μg/ml, T max : 1.12±0.23h and 1.30±0.34h, AUC (0 - 6 h) : 5.18±2.24 μg·h/ml and 45.09±14.53 μg·h/ml, t 1/2 : 1.43±0.44 h and 1.09±0.22 h., respectively. The relative bioavailability of T to R were 9 6.5±19.2 % and 98.4±26.1 % , respectively. Statistical analysis showed that th e two formulations were bioequivalent.展开更多
Amoxicillin/clavulanate is associated with liver injury, mostly of a cholestatic pattern. While outcomes are usually benign, progression to cirrhosis and death has been reported. The role of immunosuppressive therapy ...Amoxicillin/clavulanate is associated with liver injury, mostly of a cholestatic pattern. While outcomes are usually benign, progression to cirrhosis and death has been reported. The role of immunosuppressive therapy for patients with a protracted course is unclear. We report the case of an elderly patient who developed prolonged cholestasis secondary to amoxicillin/clavulanate. Vanishing bile duct syndrome was confirmed by sequential liver biopsies. The patient responded to prednisone treatment, but could not be weaned off corticosteroids, even when azathioprine was added. Complete withdrawal of both prednisone and azathioprine was possible by using mycophenolate mofetil, an inosine monophosphate dehydrogenase inhibitor. Sustained remission has been maintained for more than 3 years with low-dose mycophenolate mofetil.展开更多
Objective To assess the activities of biapenem against multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis. Methods Biapenem/clavulanate(BP/CL) was evaluated for in vitro activity against Myc...Objective To assess the activities of biapenem against multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis. Methods Biapenem/clavulanate(BP/CL) was evaluated for in vitro activity against Mycobacterium tuberculosis(Mtb) multidrug-resistant(MDR) isolates, extensively drug-resistant(XDR) isolates, and the H37 RV strain. BP/CL activity against the H37 Rv strain was assessed in liquid cultures, in macrophages, and in mice. Results BP/CL exhibited activity against MDR and XDR Mtb isolates in liquid cultures. BP/CL treatment significantly reduced the number of colony forming units(CFU) of Mtb within macrophages compared with control untreated infected macrophages. Notably, BP/CL synergized in pairwise combinations with protionamide, aminosalicylate, and capreomycin to achieve a fractional inhibitory concentration for each pairing of 0.375 in vitro. In a mouse tuberculosis infection model, the efficacy of a cocktail of levofloxacin + pyrazinamide + protionamide + aminosalicylate against Mtb increased when the cocktail was combined with BP/CL, achieving efficacy similar to that of the positive control treatment(isoniazid + rifampin + pyrazinamide) after 2 months of treatment. Conclusion BP/CL may provide a new option to clinically treat MDR tuberculosis.展开更多
A simple, fast, precise, accurate and rugged stability indicating high performance liquid chromatography (HPLC) method has been developed for simultaneous estimation of Amoxicillin and Clavulanic acid from injectable ...A simple, fast, precise, accurate and rugged stability indicating high performance liquid chromatography (HPLC) method has been developed for simultaneous estimation of Amoxicillin and Clavulanic acid from injectable dosage form. The stability indicating capability of the method was proven by subjecting the drugs to stress conditions as per ICH recommended test conditions such as alkaline and acid hydrolysis, oxidation, photolysis, thermal degradation and resolution of the degradation products formed therein. The separation was obtained using a mobile phase composition at a ratio of 95:5 (v/v) of pH 5.0 buffer and methanol on Inertsil C18 column (250 × 4.0 mm, 4 μm) with UV detection at 220 nm at a flow rate of 1 ml/minute. The photodiode array detector was used for stress studies. The order of elution of peaks was Clavulanic acid followed by Amoxicillin. The linear calibration range was found to be 79.51 to 315.32 μg/ml for Amoxicillin and 17.82 to 67.90 μg/ml for Clavulanic acid. The Amoxicillin and Clavulanic acid were found to be stable in solution up to 24 hours. The method validation data showed excellent results for precision, linearity, specificity, limit of detection, limit of quantification and robustness. The present method can be successfully used for routine quality control and stability studies.展开更多
A simple, rapid and selective liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) assay method has been developed and fully validated for the simultaneous quantification of ...A simple, rapid and selective liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) assay method has been developed and fully validated for the simultaneous quantification of cefadroxil (CF) and clavulanic acid (CA) in human plasma. Analytes and internal standard (IS) were extracted from human plasma by solid- phase extraction (SPE) technique using Sam prep (3 mL, 100 mg) extraction cartridge. The extracted samples were chromatographed on a reverse phase Cls column using a mixture of methanol: acetonitrile: 2 mM ammonium acetate (pH 3.5) (25:25:50, v/v/v) as the mobile phase at a flow rate of 0.8 mL/min. Quantification of the analytes and IS were carried out using single quadrupole LC-APCI-MS through selected-ion monitoring (SIM) at m/z 362 and m/z 198, for CF and CA, respectively. Method validation was performed as per the FDA guidelines and the results met the acceptance criteria. Plasma concentration of CF and CA followed by the oral administration of CF/CA (500/125 mg) pill to healthy male volunteers (n= 12) was measured. Area under plasma concentration-time curve from 0 to 12 h (AUC0-12 h) and 0 h extrapolated to infinity (AUC0-∞) were calculated. The ratio of AUC0-12 h/AUC0-∞ was found to be 〉 85% for all the subjects, as recommended by the FDA guidelines.展开更多
Objective: To explore the genotoxic potential and histopathological changes induced in liver, kidney, testis, brain and heart after using the antibiotic drug amoxicillin/clavulanic acid(4:1).Methods: The study include...Objective: To explore the genotoxic potential and histopathological changes induced in liver, kidney, testis, brain and heart after using the antibiotic drug amoxicillin/clavulanic acid(4:1).Methods: The study included chromosomal aberration analysis in bone-marrow and mouse spermatocytes, induction of sperm morphological abnormalities and histopathological changes in different body organs. The drug was administrated orally at a dose of81 mg/kg body weight twice daily(Total = 162 mg/kg/day) for various periods of time equivalent to 625 mg/men(twice daily).Results: The results revealed non-significant chromosomal aberrations induced after treatment with amoxicillin/clavulanic acid(AC) in both bone marrow and mouse spermatocytes after 7 and 10 days treatment. On the other hand, statistically significant percentages of sperm morphological abnormalities were recorded. Such percentage reached 8.10 ± 0.55, 9.86 ± 0.63 and 12.12 ± 0.58 at the three time intervals tested(7, 14 and 35 days after the 1 st treatment respectively)(treatment performed for 5 successive days) compared with 2.78 ± 0.48 for the control. The results also revealed histopathological changes in different body organs after AC treatment which increased with the prolongation of the period of therapy. Congestion of central vain, liver hemorrhage and hydropic changes in hepatocytes were noticed in the liver. Degenerative changes were found in kidney glomerulus and tubules while testis showed atrophy of seminiferous tubules, and reduction of spermatogenesis. AC also induced neurotoxicity and altered brain neurotransmitter levels. Hemorrhage in the myocardium, disruption of cardiac muscle fibers and pyknotic nuclei in cardiomyocytes were recorded as side effects of AC in heart tissue.Conclusions: The results concluded that AC treatment induced sperm morphological abnormalities and histopathological changes in different body organs. Clinicians must be aware of such results while describing the drug.展开更多
Aim: To assess the quality and in vitro efficacy of five brands of amoxicillin/clavulanic acid tablet, suspension and injectable preparations selected from pharmacies in the Central Region of Ghana. Method: Using a St...Aim: To assess the quality and in vitro efficacy of five brands of amoxicillin/clavulanic acid tablet, suspension and injectable preparations selected from pharmacies in the Central Region of Ghana. Method: Using a Stratified Representation Sampling method, forty preparations (tablets, suspensions and injectable powders) containing amoxicillin and clavulanic acid were sampled from nine different locations within the Central Region of Ghana. To determine drug quality, several procedures, namely, content assay, disintegration and dissolution testing were employed. In vitro drug efficacy was determined by comparing the Minimum Inhibitory Concentrations (MIC’s) obtained with published values. Results: All tablets passed the disintegration test, with disintegration time ranging between six (6) and fifteen (15) minutes. Analyses of all the tablets for drug content showed 100% failure (14 out of 14) for amoxicillin and 14% failure (2 out of 14) for clavulanic acid. Injectable formulations showed similar results. All four (4) samples analyzed for content failed the amoxicillin content assay (0 out of 4) but all passed clavulanic acid assay (4 out of 4). For tablet dissolution tests, there was a 93% (13 out of 14) pass rate for both amoxicillin and clavulanic acid. Content analysis of all suspension formulations involved twenty-two (22) samples from five (5) brands. Only 41% (9 out of 22) passed for both amoxicillin and clavulanic acid. All the other samples failed for either amoxicillin, clavulanic acid or both. Results obtained from drug quality tests were confirmed by in vitro efficacy tests against selected microorganisms. Conclusion: The samples were therefore not of good quality, since content assay is the most crucial test. It is hypothesized that this is due to poor storage conditions, and recommendations, such as air conditioning and more structured procedures along the supply chain, are put forward to counteract this.展开更多
To evaluate the comparative activity of seven oral antimicrobial agents against 100 strains of Streptococcus pneumoniae (S pneumoniae) Methods Total 100 strains of S pneumoniae were collected from gener...To evaluate the comparative activity of seven oral antimicrobial agents against 100 strains of Streptococcus pneumoniae (S pneumoniae) Methods Total 100 strains of S pneumoniae were collected from general hospitals in Beijing from June 1996 to June 1997 E test method was used to detect the minimum inhibitory concentration (MIC) values of the following seven drugs against S pneumoniae : penicillin, amoxicillin/clavulanate, cefaclor, cefuroxime, ceftriaxone, azithromycin and ofloxacin The breakpoint of susceptibility categories was defined according to NCCLS Results 74% of isolates were susceptible (S, MIC 0 06?mg/L) to penicillin, and 5% were penicillin resistant (R, MIC 2?mg/L). The intermediately resistant (I, MIC 0 1-1?mg/L) rate to penicillin was 21% The total rates of R or I were 26% for penicillin, 6% for both amoxicillin/clavulanate and ceftriaxone, 9% for cefuroxime, 66% and 68% for azithromycin and ofloxacin respectively Overall 94%, 94% and 91% of the pneumococcal isolates were susceptible to amoxicillin/clavulanate, ceftriaxone and cefuroxime respectively S pneumoniae was highly resistant to azithromycin tested as a representative of macrolides (MIC 50 and MIC 90 both >256?mg/L, R rate 66%), and had a highly intermediately resistant rate to ofloxacin (I rate 62%) Conclusions Our data suggest that in vitro activity of oral amoxicillin/clavulanate was as good as ceftriaxone and cefuroxime It can be considered as an alternative compound in the treatment of community acquired pneumoniae and other respiratory tract infections caused by multiresistant S pneumoniae展开更多
The glycerol utilization (gyl) operon is involved in clavulanic acid (CA) production by Streptomyces clavuligerus, and possibly supplies the glyceraldehyde-3-phosphate (G3P) precursor for CA biosynthesis. The gyl oper...The glycerol utilization (gyl) operon is involved in clavulanic acid (CA) production by Streptomyces clavuligerus, and possibly supplies the glyceraldehyde-3-phosphate (G3P) precursor for CA biosynthesis. The gyl operon is regulated by GylR and is induced by glycerol. To enhance CA production in S. clavuligerus, an extra copy of ccaR expressed from Pgyl (the gyl promoter) was integrated into the chromosome of S. clavuligerus NRRL 3585. This construct coordinated the transcription of CA biosynthetic pathway genes with expression of the gyl operon. In the transformants carrying the Pgyl-controlled regulatory gene ccaR, CA production was enhanced 3.19-fold in glycerol-enriched batch cultures, relative to the control strain carrying an extra copy of ccaR controlled by its own promoter (PccaR). Consistent with enhanced CA production, the transcription levels of ccaR, ceas2 and claR were significantly up-regulated in the transformants containing Pgyl-controlled ccaR.展开更多
We developed a colorimetric assay to quantify clavulanic acid (CA) in culture broth of Streptomyces clavuligerus, to facilitate screening of a large number of S. clavuligerus mutants. The assay is based on a β-1act...We developed a colorimetric assay to quantify clavulanic acid (CA) in culture broth of Streptomyces clavuligerus, to facilitate screening of a large number of S. clavuligerus mutants. The assay is based on a β-1actamase-catalyzed reaction, in which the yellow substrate nitrocefin (λmax=390 nm) is converted to a red product (λmax=486 nm). Since CA can irreversibly inhibit β-1actamase activity, the level of CA in a sample can be measured as a function of the A390]A486 ratio in the assay mixture. The sensitivity and detection window of the assay were determined to be 50 μg L -1 and 50 μg L to 10 mg L-1, respectively. The reliability of the assay was confirmed by comparing assay results with those obtained by HPLC. The assay was used to screen a pool of 65 S. clavuligerus mutants and was reliable for identifying CA over-producing mutants. Therefore, the assay saves time and labor in large-scale mutant screening and evaluation tasks. The detection window and the reliability of this assay are markedly better than those of previously reported CA assays. This assay method is suitable for high throughput screening of microbial samples and allows direct visual observation of CA levels on agar plates.展开更多
The usefulness of genetic/metabolic engineering for further improvement of industrial strains is subject of discussion because of the general lack of knowledge on genetic alterations introduced by iterative cycles of ...The usefulness of genetic/metabolic engineering for further improvement of industrial strains is subject of discussion because of the general lack of knowledge on genetic alterations introduced by iterative cycles of random mutagenesis in such strains.An industrial clavulanic acid(CA)-overproducer Streptomyces clavuligerus DEPA was assessed to understand proteome-wide changes that have occurred in a local industrial CA overproducer developed through succesive mutagenesis programs.The proteins that could be identified corresponded to 33 distinct ORFs for underrepresented ones and 60 ORFs for overrepresented ones.Three CA biosynthetic enzymes were overrepresented in S.clavuligerus DEPA;carboxyethylarginine synthase(Ceas2),clavaldehyde dehydrogenase(Car)and carboxyethyl-arginine betalactam-synthase(Bls2)whereas the enzymes of two other secondary metabolites were underrepresented along with two important global regulators[two-component system(TCS)response regulator(SCLAV_2102)and TetR-family transcriptional regulator(SCLAV_3146)]that might be related with CA production and/or differentiation.g-butyrolactone biosynthetic protein AvaA2 was 2.6 fold underrepresented in S.clavuligerus DEPA.The levels of two glycolytic enzymes,2,3-bisphosphoglycerate-dependent phosphoglycerate mutase and phosophoglycerate kinase were found decreased while those of dihydrolipoyl dehydrogenase(E3)and isocitrate dehydrogenase,with two isoforms were found as significantly increased.A decrease of amino acid metabolism,methionine biosynthesis in particular,as well as S-adenosylmethionine synthetase appeared as one of the prominent mechanisms of success of S.clavuligerus DEPA strain as a prolific producer of CA.The levels of two enzymes of shikimate pathway that leads to the production of aromatic amino acids and aromatic secondary metabolites were also underrepresented.Some of the overrepresented stress proteins in S.clavuligerus DEPA included polynucleotide phosphorylase/polyadenylase(PNPase),ATP-dependent DNA helicase,two isoforms of an anti-sigma factor and thioredoxin reductase.Downregulation of important proteins of cell wall synthesis and division was recorded and a protein with b-lactamase domain(SCLAV_p1007)appeared in 12 isoforms,5 of which were drastically overrepresented in DEPA strain.These results described herein provide useful information for rational engineering to improve CA production in Streptomyces clavuligerus.展开更多
文摘Real-world evidence (RWE) is clinical evidence on a medical product’s safety and efficacy that is generated using real-world data (RWD) resulting from routine healthcare delivery. This study evaluates the clinical efficacy of amoxicillin + clavulanic acid in children with pharyngitis, acute otitis, or acute rhinosinusitis with suspected bacterial origin under normal office and home conditions. Methods: This was a real-life, prospective, observational, pharmacovigilance study. It included children of both sexes between 2 and 12 years old, with a diagnosis of Rhinopharyngitis (tonsillitis), Acute Otitis Media and Rhinosinusitis. The main effectiveness variable evaluated was reduction and time to resolution of symptoms. All patients received Amoxicillin/Clavulanic Acid suspension 600 mg/42.9 mg/5 mL at a dose of 90 mg/Kg/day in two doses, every 12 hours for 7 days. The evaluations were carried out at the beginning, at 72 hours (3rd day) and at 7 days. All patients underwent culture and antibiogram. Results: The majority of cultures were negative for pathogenic germs, suspecting unidentifiable germs, or viral etiology despite the rigorous selection of subjects following validated scores. The most frequently isolated germ was Staphylococcus aureus;growth of gram-negative bacteria was reported in 33.33% of the cultures. There was a significant improvement in symptoms in children with tonsillitis and rhinosinusitis from the first 72 hours of treatment, persisting until the 7 days. In the otitis media group, returning to normal by the tenth day. During the conduction of this investigation, no adverse effects associated with the prescribed therapy were reported.
文摘Introduction: The efficacy of amoxicillin combined with clavulanic acid in Acute Otitis Media (AOM) is not debatable, but studies report a high frequency of gastrointestinal adverse effects related to this intervention. In this scenario, several studies about the antibiotic cefprozil report that it has the same efficacy as amoxicillin/clavulanate for the treatment of AOM with significantly fewer side effects. The aim of our study was to compare the efficacy and safety of both treatments in AOM. Methodology: We searched for clinical trials and systematic reviews with or without meta-analyses in the Cochrane Group Register and the MEDLINE database up to November 2013, comparing the two interventions mentioned. Results were expressed as a rate of treatment failures or favorable response rates (clinical and microbiological in both cases), and as the rate of adverse events. The analysis was carried out considering the fixed and random effects models. The significance level used in the test for heterogeneity was 0.05. Funnel plot was used to search for publication bias. Results: 7 clinical trials were included in the analysis and no significant difference was found for both interventions regarding clinical and bacteriological response (RR = 1.02, 95% CI, 0.97-1.06, p = 0.780 and RR = 1.02, 95% CI, 0.99-1.07, p = 0.228, respectively). However, a significant difference was found in the comparison of adverse effects, showing that amoxicillin/clavulanate has a significantly higher risk of developing side effects than cefprozil (RR = 0.52, 95% CI, 0.45-0.59, p = 0.000). Conclusion: Both treatments demonstrated equal clinical and microbiological efficacy. However, the use of cefprozil is significantly associated with a lower risk of adverse effects.
文摘To study the bioequivalence of Clavulanate Potassium and Amoxicillin (1:7) dispersible tablets, a randomized cross over study was conducted in 18 healthy volunteers. A single oral dose of 1000 mg Clav ulanate Potassium and Amoxicillin (1:7) dispersible tablets (Tested formulation, T) or Augmentin syrup (Reference formulation, R). Concentrations in plasma were determined with high performance liquid chromatography. The main paramaters of T were: for Clavulanate Potassium and Amoxicillin, C max : 2.46±1.11 μg/m l and 18.81±7.26 μg/ml, T max : 1.12±0.23h and 1.30±0.34h, AUC (0 - 6 h) : 5.18±2.24 μg·h/ml and 45.09±14.53 μg·h/ml, t 1/2 : 1.43±0.44 h and 1.09±0.22 h., respectively. The relative bioavailability of T to R were 9 6.5±19.2 % and 98.4±26.1 % , respectively. Statistical analysis showed that th e two formulations were bioequivalent.
文摘Amoxicillin/clavulanate is associated with liver injury, mostly of a cholestatic pattern. While outcomes are usually benign, progression to cirrhosis and death has been reported. The role of immunosuppressive therapy for patients with a protracted course is unclear. We report the case of an elderly patient who developed prolonged cholestasis secondary to amoxicillin/clavulanate. Vanishing bile duct syndrome was confirmed by sequential liver biopsies. The patient responded to prednisone treatment, but could not be weaned off corticosteroids, even when azathioprine was added. Complete withdrawal of both prednisone and azathioprine was possible by using mycophenolate mofetil, an inosine monophosphate dehydrogenase inhibitor. Sustained remission has been maintained for more than 3 years with low-dose mycophenolate mofetil.
基金supported by the Beijing Medical Award Foundation [YJHYXKYJJ-104]
文摘Objective To assess the activities of biapenem against multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis. Methods Biapenem/clavulanate(BP/CL) was evaluated for in vitro activity against Mycobacterium tuberculosis(Mtb) multidrug-resistant(MDR) isolates, extensively drug-resistant(XDR) isolates, and the H37 RV strain. BP/CL activity against the H37 Rv strain was assessed in liquid cultures, in macrophages, and in mice. Results BP/CL exhibited activity against MDR and XDR Mtb isolates in liquid cultures. BP/CL treatment significantly reduced the number of colony forming units(CFU) of Mtb within macrophages compared with control untreated infected macrophages. Notably, BP/CL synergized in pairwise combinations with protionamide, aminosalicylate, and capreomycin to achieve a fractional inhibitory concentration for each pairing of 0.375 in vitro. In a mouse tuberculosis infection model, the efficacy of a cocktail of levofloxacin + pyrazinamide + protionamide + aminosalicylate against Mtb increased when the cocktail was combined with BP/CL, achieving efficacy similar to that of the positive control treatment(isoniazid + rifampin + pyrazinamide) after 2 months of treatment. Conclusion BP/CL may provide a new option to clinically treat MDR tuberculosis.
文摘A simple, fast, precise, accurate and rugged stability indicating high performance liquid chromatography (HPLC) method has been developed for simultaneous estimation of Amoxicillin and Clavulanic acid from injectable dosage form. The stability indicating capability of the method was proven by subjecting the drugs to stress conditions as per ICH recommended test conditions such as alkaline and acid hydrolysis, oxidation, photolysis, thermal degradation and resolution of the degradation products formed therein. The separation was obtained using a mobile phase composition at a ratio of 95:5 (v/v) of pH 5.0 buffer and methanol on Inertsil C18 column (250 × 4.0 mm, 4 μm) with UV detection at 220 nm at a flow rate of 1 ml/minute. The photodiode array detector was used for stress studies. The order of elution of peaks was Clavulanic acid followed by Amoxicillin. The linear calibration range was found to be 79.51 to 315.32 μg/ml for Amoxicillin and 17.82 to 67.90 μg/ml for Clavulanic acid. The Amoxicillin and Clavulanic acid were found to be stable in solution up to 24 hours. The method validation data showed excellent results for precision, linearity, specificity, limit of detection, limit of quantification and robustness. The present method can be successfully used for routine quality control and stability studies.
文摘A simple, rapid and selective liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) assay method has been developed and fully validated for the simultaneous quantification of cefadroxil (CF) and clavulanic acid (CA) in human plasma. Analytes and internal standard (IS) were extracted from human plasma by solid- phase extraction (SPE) technique using Sam prep (3 mL, 100 mg) extraction cartridge. The extracted samples were chromatographed on a reverse phase Cls column using a mixture of methanol: acetonitrile: 2 mM ammonium acetate (pH 3.5) (25:25:50, v/v/v) as the mobile phase at a flow rate of 0.8 mL/min. Quantification of the analytes and IS were carried out using single quadrupole LC-APCI-MS through selected-ion monitoring (SIM) at m/z 362 and m/z 198, for CF and CA, respectively. Method validation was performed as per the FDA guidelines and the results met the acceptance criteria. Plasma concentration of CF and CA followed by the oral administration of CF/CA (500/125 mg) pill to healthy male volunteers (n= 12) was measured. Area under plasma concentration-time curve from 0 to 12 h (AUC0-12 h) and 0 h extrapolated to infinity (AUC0-∞) were calculated. The ratio of AUC0-12 h/AUC0-∞ was found to be 〉 85% for all the subjects, as recommended by the FDA guidelines.
基金supported by the project in National Research Centre under grant number: 10090013, Cairo, Egypt
文摘Objective: To explore the genotoxic potential and histopathological changes induced in liver, kidney, testis, brain and heart after using the antibiotic drug amoxicillin/clavulanic acid(4:1).Methods: The study included chromosomal aberration analysis in bone-marrow and mouse spermatocytes, induction of sperm morphological abnormalities and histopathological changes in different body organs. The drug was administrated orally at a dose of81 mg/kg body weight twice daily(Total = 162 mg/kg/day) for various periods of time equivalent to 625 mg/men(twice daily).Results: The results revealed non-significant chromosomal aberrations induced after treatment with amoxicillin/clavulanic acid(AC) in both bone marrow and mouse spermatocytes after 7 and 10 days treatment. On the other hand, statistically significant percentages of sperm morphological abnormalities were recorded. Such percentage reached 8.10 ± 0.55, 9.86 ± 0.63 and 12.12 ± 0.58 at the three time intervals tested(7, 14 and 35 days after the 1 st treatment respectively)(treatment performed for 5 successive days) compared with 2.78 ± 0.48 for the control. The results also revealed histopathological changes in different body organs after AC treatment which increased with the prolongation of the period of therapy. Congestion of central vain, liver hemorrhage and hydropic changes in hepatocytes were noticed in the liver. Degenerative changes were found in kidney glomerulus and tubules while testis showed atrophy of seminiferous tubules, and reduction of spermatogenesis. AC also induced neurotoxicity and altered brain neurotransmitter levels. Hemorrhage in the myocardium, disruption of cardiac muscle fibers and pyknotic nuclei in cardiomyocytes were recorded as side effects of AC in heart tissue.Conclusions: The results concluded that AC treatment induced sperm morphological abnormalities and histopathological changes in different body organs. Clinicians must be aware of such results while describing the drug.
文摘Aim: To assess the quality and in vitro efficacy of five brands of amoxicillin/clavulanic acid tablet, suspension and injectable preparations selected from pharmacies in the Central Region of Ghana. Method: Using a Stratified Representation Sampling method, forty preparations (tablets, suspensions and injectable powders) containing amoxicillin and clavulanic acid were sampled from nine different locations within the Central Region of Ghana. To determine drug quality, several procedures, namely, content assay, disintegration and dissolution testing were employed. In vitro drug efficacy was determined by comparing the Minimum Inhibitory Concentrations (MIC’s) obtained with published values. Results: All tablets passed the disintegration test, with disintegration time ranging between six (6) and fifteen (15) minutes. Analyses of all the tablets for drug content showed 100% failure (14 out of 14) for amoxicillin and 14% failure (2 out of 14) for clavulanic acid. Injectable formulations showed similar results. All four (4) samples analyzed for content failed the amoxicillin content assay (0 out of 4) but all passed clavulanic acid assay (4 out of 4). For tablet dissolution tests, there was a 93% (13 out of 14) pass rate for both amoxicillin and clavulanic acid. Content analysis of all suspension formulations involved twenty-two (22) samples from five (5) brands. Only 41% (9 out of 22) passed for both amoxicillin and clavulanic acid. All the other samples failed for either amoxicillin, clavulanic acid or both. Results obtained from drug quality tests were confirmed by in vitro efficacy tests against selected microorganisms. Conclusion: The samples were therefore not of good quality, since content assay is the most crucial test. It is hypothesized that this is due to poor storage conditions, and recommendations, such as air conditioning and more structured procedures along the supply chain, are put forward to counteract this.
文摘To evaluate the comparative activity of seven oral antimicrobial agents against 100 strains of Streptococcus pneumoniae (S pneumoniae) Methods Total 100 strains of S pneumoniae were collected from general hospitals in Beijing from June 1996 to June 1997 E test method was used to detect the minimum inhibitory concentration (MIC) values of the following seven drugs against S pneumoniae : penicillin, amoxicillin/clavulanate, cefaclor, cefuroxime, ceftriaxone, azithromycin and ofloxacin The breakpoint of susceptibility categories was defined according to NCCLS Results 74% of isolates were susceptible (S, MIC 0 06?mg/L) to penicillin, and 5% were penicillin resistant (R, MIC 2?mg/L). The intermediately resistant (I, MIC 0 1-1?mg/L) rate to penicillin was 21% The total rates of R or I were 26% for penicillin, 6% for both amoxicillin/clavulanate and ceftriaxone, 9% for cefuroxime, 66% and 68% for azithromycin and ofloxacin respectively Overall 94%, 94% and 91% of the pneumococcal isolates were susceptible to amoxicillin/clavulanate, ceftriaxone and cefuroxime respectively S pneumoniae was highly resistant to azithromycin tested as a representative of macrolides (MIC 50 and MIC 90 both >256?mg/L, R rate 66%), and had a highly intermediately resistant rate to ofloxacin (I rate 62%) Conclusions Our data suggest that in vitro activity of oral amoxicillin/clavulanate was as good as ceftriaxone and cefuroxime It can be considered as an alternative compound in the treatment of community acquired pneumoniae and other respiratory tract infections caused by multiresistant S pneumoniae
基金supported by grants from the Ministry of Science and Technology of China (2009CB118905)
文摘The glycerol utilization (gyl) operon is involved in clavulanic acid (CA) production by Streptomyces clavuligerus, and possibly supplies the glyceraldehyde-3-phosphate (G3P) precursor for CA biosynthesis. The gyl operon is regulated by GylR and is induced by glycerol. To enhance CA production in S. clavuligerus, an extra copy of ccaR expressed from Pgyl (the gyl promoter) was integrated into the chromosome of S. clavuligerus NRRL 3585. This construct coordinated the transcription of CA biosynthetic pathway genes with expression of the gyl operon. In the transformants carrying the Pgyl-controlled regulatory gene ccaR, CA production was enhanced 3.19-fold in glycerol-enriched batch cultures, relative to the control strain carrying an extra copy of ccaR controlled by its own promoter (PccaR). Consistent with enhanced CA production, the transcription levels of ccaR, ceas2 and claR were significantly up-regulated in the transformants containing Pgyl-controlled ccaR.
基金supported by the Young Scientists Fund (Grant No. 31000025) from the National Natural Science Foundation of ChinaNational High Technology Research and Development Program of China (Grant No. 2012AA021302)
文摘We developed a colorimetric assay to quantify clavulanic acid (CA) in culture broth of Streptomyces clavuligerus, to facilitate screening of a large number of S. clavuligerus mutants. The assay is based on a β-1actamase-catalyzed reaction, in which the yellow substrate nitrocefin (λmax=390 nm) is converted to a red product (λmax=486 nm). Since CA can irreversibly inhibit β-1actamase activity, the level of CA in a sample can be measured as a function of the A390]A486 ratio in the assay mixture. The sensitivity and detection window of the assay were determined to be 50 μg L -1 and 50 μg L to 10 mg L-1, respectively. The reliability of the assay was confirmed by comparing assay results with those obtained by HPLC. The assay was used to screen a pool of 65 S. clavuligerus mutants and was reliable for identifying CA over-producing mutants. Therefore, the assay saves time and labor in large-scale mutant screening and evaluation tasks. The detection window and the reliability of this assay are markedly better than those of previously reported CA assays. This assay method is suitable for high throughput screening of microbial samples and allows direct visual observation of CA levels on agar plates.
基金We acknowledge the Scientific and Technical Research Council of Turkey[TÜB_ITAK-KBAG,Grant No:114Z648]Middle East Technical University Research Fund[BAP-07-02-2014-007-050]for partially supporting this study.
文摘The usefulness of genetic/metabolic engineering for further improvement of industrial strains is subject of discussion because of the general lack of knowledge on genetic alterations introduced by iterative cycles of random mutagenesis in such strains.An industrial clavulanic acid(CA)-overproducer Streptomyces clavuligerus DEPA was assessed to understand proteome-wide changes that have occurred in a local industrial CA overproducer developed through succesive mutagenesis programs.The proteins that could be identified corresponded to 33 distinct ORFs for underrepresented ones and 60 ORFs for overrepresented ones.Three CA biosynthetic enzymes were overrepresented in S.clavuligerus DEPA;carboxyethylarginine synthase(Ceas2),clavaldehyde dehydrogenase(Car)and carboxyethyl-arginine betalactam-synthase(Bls2)whereas the enzymes of two other secondary metabolites were underrepresented along with two important global regulators[two-component system(TCS)response regulator(SCLAV_2102)and TetR-family transcriptional regulator(SCLAV_3146)]that might be related with CA production and/or differentiation.g-butyrolactone biosynthetic protein AvaA2 was 2.6 fold underrepresented in S.clavuligerus DEPA.The levels of two glycolytic enzymes,2,3-bisphosphoglycerate-dependent phosphoglycerate mutase and phosophoglycerate kinase were found decreased while those of dihydrolipoyl dehydrogenase(E3)and isocitrate dehydrogenase,with two isoforms were found as significantly increased.A decrease of amino acid metabolism,methionine biosynthesis in particular,as well as S-adenosylmethionine synthetase appeared as one of the prominent mechanisms of success of S.clavuligerus DEPA strain as a prolific producer of CA.The levels of two enzymes of shikimate pathway that leads to the production of aromatic amino acids and aromatic secondary metabolites were also underrepresented.Some of the overrepresented stress proteins in S.clavuligerus DEPA included polynucleotide phosphorylase/polyadenylase(PNPase),ATP-dependent DNA helicase,two isoforms of an anti-sigma factor and thioredoxin reductase.Downregulation of important proteins of cell wall synthesis and division was recorded and a protein with b-lactamase domain(SCLAV_p1007)appeared in 12 isoforms,5 of which were drastically overrepresented in DEPA strain.These results described herein provide useful information for rational engineering to improve CA production in Streptomyces clavuligerus.