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Studies on the biosynthesis of clavulanic acid. III. Incorporation of DL-[3,4-13C2]glutamic acid.

The role of glutamate in clavulanic acid biosynthesis was investigated by feeding DL-[3,4-13C2]glutamate to a Streptomyces clavuligerus fermentation. The DL-[3,4-13C2]glutamate was synthesised by reacting [2-13C]diethylmalonate with O-tosyl-N-benzoyl-[3-13C]dehydroserine ethyl ester, which in turn was synthesised by condensing [13C]ethylformate with N-benzoylglycine ethyl ester. 13C NMR examination of the benzyl clavulanate derived from the fermentation revealed the predicted labelling of carbons 2 and 8 with accompanying 13C-13C spin-spin coupling. Other enrichments and couplings were observed which could be explained by metabolism of the labelled glutamate via the tricarboxylic acid cycle to give further clavulanic acid precursors. These results confirm that glutamate provides the oxazolidine carbon skeleton as predicted by previous experiments.

Anti-Bacterial Agents↗

Ticarcillin plus clavulanic acid in the treatment of pneumonia and other serious infections.

Clavulanic acid is a potent inhibitor of bacterial beta-lactamases, and ticarcillin is a potent antipseudomonal penicillin. The combination of ticarcillin disodium and clavulanate potassium provides an excellent spectrum of activity against the majority of bacterial pathogens responsible for serious infections in both normal and abnormal hosts. Eighteen courses of therapy were administered to 16 patients; 35 percent of the patients were in poor or critical condition, and all but one had severe underlying disease. Thirteen separate episodes of pneumonia were treated, of which nine were in patients with cystic fibrosis, and 11 involved Pseudomonas aeruginosa. Of the 13 cases of pneumonia, 11 showed clinical cure or improvement, whereas only three showed bacteriologic cure. Of the four nonpulmonary cases, three showed clinical improvement or cure, and one showed a bacteriologic cure. In two patients, phlebitis developed at the site of intravenous infusion. The combination of ticarcillin and clavulanic acid is safe and effective therapy for pneumonia in anatomically compromised hosts.

Adolescent↗

Combined application of amoxicillin and clavulanic acid after oral surgical interventions.

Antibiotics represent a powerful weapon against infections. As dentists we are faced almost on a daily basis with the need to prescribe antibiotics. At the same time, we can often see that the antibiotics use tends to get out of control or that they are used indiscriminately with no real need. The aim of this case study is to investigate the effectiveness of amoxicillin and clavulanic acid combination in various dental ailments but also to demonstrate possible difference in the severity of symptoms after the use of amoxicillin and antibiotic combination of amoxicillin and clavulanic acid after surgical and oral interventions. The investigation involved 102 patients who were divided into two groups (the first group consisting of 59 and the second one of 43 patients). Following surgical treatment the first group of patients was prescribed antibiotic combination of amoxicillin and clavulanic acid in the dosage of 625 mg, 3 times per day. The second group of 43 patients was prescribed amoxicillin in the dosage of 500 mg, 4 times per day. The recommended therapy for antibiotic combination of amoxicillin and clavulanic acid was 5 to 10 days after the operation and 8 to 10 days for amoxicillin. In other words, both groups of patients started to use antibiotics after the surgical or oral intervention such as operative removal of impacted wisdom teeth, apicoectomy or complicated extractions, and also after the treatment of odontogenic abscesses etc. The same parameters were measured prior to the surgical intervention in cases when patients demonstrated the symptoms before the operational treatment while in all other cases the parameters were measured 48 hours and seven days following the operation. The measured parameters were: pain, swelling, body temperature, dysfunction such as dysphagus trismus, chewing disorder and possible allergic or gastrointestinal reactions. All parameters observed were precisely set in order to harmonize the investigation criteria and facilitate statistical data processing. With respect to pain before the operation there was no substantial statistical difference, p>0.05 (t=0.56; t=0.69). With respect to the onset of pain and the use of antibiotics after 48 hours there is a significant difference in favor of antibiotic combination of amoxicillin and clavulanic acid (X= 14.83, p= 0.002; p <0.01). Thus, pain is less acute if antibiotic combination of amoxicillin and clavulanic acid is administered. With respect to swelling and administration of antibiotics 48 hours after the operation there is no significant difference between the use of the two antibiotic therapies (X= 4.89; p=0.18; p>0.05). The investigation conducted seven days after the operation with regard to pain and the use of either antibiotic therapies demonstrated significant statistical difference (X=9.35, p<0.01) in favor of antibiotic combination of amoxicillin and clavulanic acid. In other words, patients who used amoxicillin and clavulanic acid felt significantly less intense pain. With respect to swelling, significant statistical difference between the two groups of patients was established in favor of antibiotic combination of amoxicillin and clavulanic acid, i.e. p<0.05 (X=6.45, p=0.03). The combination of amoxicillin and clavulanic has proven to be significantly more effective in comparison with the use of amoxicillin after oral-surgical interventions, and therefore antibiotic combination of amoxicillin and clavulanic acid is recommended for use in further practice.

Amoxicillin↗

Antibacterial activities of amoxicillin alone and in combination with clavulanic acid correlated with beta-lactamase production.

Amoxicillin, a beta-lactam antibiotic, was tested for its effect in combination with clavulanic acid, a beta-lactamase inhibitor, against 9 species of bacteria isolated from clinical specimens. A total of 698 strains of bacteria were tested for beta-lactamase production by the rapid chromogenic cephalosporin method. Their susceptibilities to amoxicillin alone and in combination with clavulanic acid were tested by the agar dilution method. The percentage of beta-lactamase producing strains ranged from 46.6% in Proteus mirabilis to 100% in Klebsiella pneumoniac. In general, beta-lactamase nonproducers were more susceptible to amoxicillin than beta-lactamase producers. For beta-lactamase producers, clavulanic acid decreased the MICs of amoxicillin prominently in strains of Neisseria gonorrhoeae, Haemophilus influenzae, Escherichia coli, K. pneumoniae, P. mirabilis, Enterobacter cloacae and Bacteroides fragilis, when combining clavulanic acid with amoxicillin in the ratio of 1:2. Their MIC50s, MIC90s and geometric means of MICs all decreased 4 folds or greater. For beta-lactamase non-producing strains, the MICs did not show significant differences by adding clavulanic acid in most species we tested, including methicillin-sensitive Staphylococcus aureus, N. gonorrhoeae, H. influenzae, Proteus vulgaris and E. cloacae.

Amoxicillin↗

Amoxycillin with clavulanic acid and tetracycline in periodontal therapy.

The effects of tetracycline and amoxycillin with clavulanic acid on the clinical parameters and subgingival flora of eight patients with rapidly progressive periodontitis was assessed. Subjects received either tetracycline 250 mg four times daily or amoxycillin 250 mg with clavulanic acid 125 mg three times daily for a period of 2 weeks together with subgingival scaling and root planning. Both treatment regimens produced significant reductions in bleeding on probing and probing pocket depths which were still present 16 weeks after the antibiotic therapy. A significant reduction in the mean percentage of black-pigmented Bacteroides spp., Fusobacterium nucleatum and anaerobic corroding bacilli was also obtained. Both treatment regimens were equally effective in reducing the clinical parameter and altering the subgingival flora. The MIC values for Bacteroides gingivalis (Porphyromonas gingivalis). Bacteroides intermedius (Prevotella intermedia) and F. nucleatum to amoxycillin with clavulanic acid remained constant throughout the period of investigation. The MIC values of these organisms to tetracycline increased.

Amoxicillin↗

Prospective randomized study comparing amoxicillin-clavulanic acid with cefazolin as antimicrobial prophylaxis in laparotomic gynecologic surgery.

BACKGROUND: To compare amoxicillin-clavulanic acid with cefazolin as ultra-short-term prophylaxis in laparotomic gynecologic surgery. MATERIALS AND METHODS: A prospective randomized study was conducted to compare two antimicrobial regimens in surgical prophylaxis of laparotomic surgery. Patients were randomly allocated to receive amoxicillin-clavulanic acid (2.2 g) [Group A] or cefazolin (2 g) [Group B] as a single dose 30 min before surgery. Each patient was assessed daily until discharge to evidence febrile status and the presence of infections at the operative site, urinary tract, and respiratory tract. RESULTS: In the amoxicillin-clavulanic acid (Group A) and cefazolin (Group B) groups, overall 346 and 352 patients, respectively, were evaluable for prophylactic efficacy at hospital discharge. Infectious complications were infrequent in both arms. Febrile morbidity occurred in 21 (6.1%) and 26 (7.4%) patients, respectively, in the amoxicillin-clavulanic acid and cefazolin groups. Wound infection and urinary tract infection were also higher, but not significantly in the cefazolin group (0.5% vs. 1.1% and 2.0% vs. 2.5%, respectively). There was one respiratory tract infection (0.2%) in Group B, and no septic death in either groups. CONCLUSION: Ultra-short-term prophylaxis with both amoxicillin-clavulanic acid and cefazolin is safe in elective laparotomic gynecologic surgery.

Adult↗

Utilization of ornithine and arginine as specific precursors of clavulanic acid.

Ornithine and arginine (5 to 20 mM), but not glutamic acid or proline, exerted a concentration-dependent stimulatory effect on the biosynthesis of clavulanic acid in both resting-cell cultures and long-term fermentations of Streptomyces clavuligerus. Ornithine strongly inhibited cephamycin biosynthesis in the same strain. [1-14C]-, [5-14C]-, or [U-14 C] ornithine was efficiently incorporated into clavulanic acid, whereas the incorporation of uniformly labeled glutamic acid was very poor. [U-14C] citrulline were not incorporated at all. Mutant nca-1, a strain that is blocked in clavulanic acid biosynthesis, did not incorporate arginine into clavulanic acid. S. clavuligerus showed arginase activity, converting arginine into ornithine, but not amidinotransferase activity. Both arginase activity and clavulanic acid formation were enhanced simultaneously by supplementing the production medium with 10 mM arginine.

Arginine↗

Simulation of human serum pharmacokinetics of ticarcillin-clavulanic acid and ceftazidime in rabbits, and efficacy against experimental Klebsiella pneumoniae meningitis.

The penetration into cerebrospinal fluid (CSF) and efficacy of ticarcillin-clavulanic acid, ticarcillin alone, and ceftazidime were compared in rabbits with experimentally induced Klebsiella pneumoniae meningitis. The compounds were administered to simulate in rabbit plasma the concentration-versus-time curves observed in humans after 30-min infusions of Timentin (3 g of ticarcillin plus 100 mg of clavulanic acid), ticarcillin (3 g), and ceftazidime (2 g). Single- and multiple-dosing schedules were used. The penetrations of clavulanic acid into CSF (expressed as [area under the concentration-time curve for CSF/area under the curve for plasma] x 100) after the two dosing schedules were 28 and 24.5%, similar to that for ceftazidime (21%; multiple-dosing only) and greater than those for ticarcillin (8.4 and 9.3%). Ticarcillin was ineffective in reducing viable counts in CSF but, in the presence of clavulanic acid, reduced bacterial numbers by approximately 99% at 4 h after a single dose and by 99.99% at 12 h after three doses given at 4-h intervals. Two doses of ceftazidime given 8 h apart were more effective than the three doses of ticarcillin-clavulanic acid, in keeping with the in vitro activities of these compounds against the infecting organism. These results illustrate the ability of clavulanic acid to penetrate the blood-CSF barrier such that concentrations of the inhibitor in CSF potentiate the activity of ticarcillin against the ticarcillin-resistant, beta-lactamase-producing strain of K. pneumoniae.

Animals↗

Pharmacology of ticarcillin combined with clavulanic acid in humans.

Serum and urine levels of ticarcillin and clavulanic acid after administration of doses of 50 mg/kg and 1.7 mg/kg or 50 mg/kg and 3 g/0.1 g, respectively, are potentially toxic to susceptible bacteria. Both compounds are widely distributed in body tissues and fluids, with concentrations exceeding the minimal inhibitory concentrations of most pathogens. Excretion is primarily renal, although there is some metabolism of clavulanate in the body. Due to accumulation, dosage adjustment is required for patients with renal insufficiency. Both ticarcillin and clavulanic acid are cleared by hemodialysis.

Clavulanic Acid↗

Antibiotic interaction of amoxycillin and clavulanic acid against 132 beta-lactamase positive Haemophilus isolates: a comparison with some other oral agents.

We studied the specific beta-lactamase inhibitory activity of clavulanic acid in association with amoxycillin against 132 beta-lactamase producing Haemophilus isolates. Inhibitory synergy between amoxycillin and clavulanic acid (ratio 2:1) was found in 131/132, partial synergy or antagonism in none; bactericidal synergy was found in 124/131, partial synergy in 4 and antagonism in 1. In comparison, inhibitory synergy between trimethoprim and sulphamethoxazole (ratio 1:19) was found in only 39/104 beta-lactamase positive strains, partial synergy in 42 and antagonism in 3 and bactericidal synergy in 18/104, partial synergy in 8 and antagonism in 3. The amoxycillin-clavulanic acid combination expressed significantly (P less than 0.001) more frequent synergy, at both inhibitory and bactericidal levels, than the trimethoprim-sulphamethoxazole combination. The synergy of amoxycillin-clavulanic acid resulted in a significant decrease of MIC90 (greater than or equal to 32.0-2.0 mg/l) and MBC90 (greater than or equal to 32.0-4.0 mg/l) of amoxycillin; the synergy of trimethoprim-sulphamethoxazole resulted in a significant decrease of MIC90 (8.0-2.0 mg/l) of trimethoprim but did not change MBC90. The amoxycillin-clavulanic acid combination was also more active than cefaclor or erythromycin alone against the 132 beta-lactamase producing strains.

Amoxicillin↗

Influence of dissolved oxygen and shear conditions on clavulanic acid production by Streptomyces clavuligerus.

Clavulanic acid (CA), a potent beta-lactamase inhibitor, is produced by a filamentous bacterium. Here, the effect of DO and shear, expressed as impeller tip velocity, on CA production was examined. Cultivations were performed in a 4 L fermentor with speeds of 600, 800 and 1,000 rpm and a fixed air flow rate (0.5 vvm). Also, cultivation with automatic control of dissolved oxygen, at 50% air saturation, by varying stirrer speed and using a mixture of air and O(2) (10% v/v) in the inlet gas, and a cultivation with fixed stirrer speed of 800 rpm and air flow rate of 0.5 vvm, enriched with 10% v/v O(2), were performed. Significant variations in CA titer, CA production rate and O(2) uptake-rate were observed. It was also found that the DO level has no remarkable effect on CA production once a critical level is surpassed. The most significant improvement in CA production was related to high stirrer speeds.

Bioreactors↗

Effect of clavulanic acid on minimal inhibitory concentrations of 16 antimicrobial agents tested against Legionella pneumophila.

A total of 15 Legionella pneumophilia isolated were tested against 16 antimicrobial agents used singly and in combination with clavulanic acid. When combined with clavulanic acid, 4 of the 16 antimicrobial agents produced no enhanced effect. However, the minimal inhibitory concentrations of 12 of the antimicrobial agents were reduced by one-half to one-third when in combination with clavulanic acid. These reductions reflected only a one-dilution decrease, however, in the original minimal inhibitory concentrations. Thus, clavulanic acid combinations appear to be only nominally effective beta-lactamase inhibitors against L. pneumophilia.

Anti-Bacterial Agents↗

[A simple enzyme assay for the simultaneous determination of penicillin derivatives and clavulanic acid in biological fluids].

A simple enzymatic assay for simultaneous determinations of amino-/ureidopenicillins and clavulanic acid concentrations in various body fluids is described; no pretreatment of the samples is required. The assay is based on the competitive inhibition of the chromogenic compound Padac by clavulanic acid in the presence of Proteus vulgaris beta-lactamase. Detection limit for clavulanic acid amounts 0.02 mg/l. Interferences with other antibiotics such as aminoglycosides, macrolides, quinolones etc. can be ruled out.

Binding, Competitive↗

In vitro and in vivo synergism between amoxicillin and clavulanic acid against ampicillin-resistant Haemophilus influenzae type b.

Eight strans of ampicillin-resistant beta-lactamase-producing Haemophilus influenzae type b were studied in vitro for synergy between amoxicillin and clavulanic acid. The minimal inhibitory concentrations for amoxicillin alone were 6.25 to 12.5 microgram/ml, and for clavulanic acid alone they were 12.5 to 25 microgram/ml. However, seven of eight strains were inhibited by a combination of 0.36 microgram of amoxicillin and 0.36 microgram of clavulanic acid per ml. Infant rat models of bacteremia and meningitis were used to test the efficacy of amoxicillin and clavulanic acid alone and in combination upon four strains of ampicillin-resistant H. influenzae. Neither amoxicillin alone (27 animals) nor clavulanic acid alone (20 animals) sterilized the blood or cerebrospinal fluid of the animals. In contrast, 30 of 33 blood cultures and 29 of 33 cerebrospinal fluid cultures were sterile when a combination of the two drugs in the same dosages was used. The observed in vitro and in vivo synergism between amoxicillin and clavulanic acid suggests that the combination may be effective therapy for invasive infections in humans caused by ampicillin-resistant H. influenzae type b.

Amoxicillin↗

Amoxicillin-clavulanic acid versus cefotaxime in the therapy of bacterial infections in cirrhotic patients.

BACKGROUND/AIM: Cefotaxime is considered the first-choice antibiotic for empirical treatment in cirrhotic patients developing bacterial infections. It has been suggested that amoxicillin-clavulanic acid could be an alternative to cefotaxime, particularly in patients developing bacterial infections while on prophylactic norfloxacin. The aim of the present study was to compare amoxicillin-clavulanic acid with cefotaxime in the treatment of bacterial infections in cirrhosis. METHODS: Ninety-six hospitalized cirrhotic patients with suspicion of bacterial infection were prospectively included and randomized into two groups: one group (n=48) received amoxicillin-clavulanic acid, first intravenously 1 g-0.2 g every 8 h, and then orally 500 mg-125 mg every 8 h, and the other group (n=48) received intravenous cefotaxime 1 g every 6 h. Patients were stratified for previous prophylaxis with norfloxacin and ascitic fluid infection. RESULTS: Sixteen patients were excluded from the analysis because bacterial infection was not demonstrated or because of secondary peritonitis. Therefore, 38 patients from the amoxicillin-clavulanic acid group and 42 from the cefotaxime group were finally analyzed. There were 24 ascitic fluid infections in each group. Infection resolution (86.8% vs 88%, 95% CI: -0.15 to 0.13, p NS), spontaneous bacterial peritonitis resolution (87.5% vs 83.3%, 95% CI: -0.15 to 0.24, p NS), duration of treatment, incidence of complications, time of hospitalization and hospital mortality were similar in both groups. Considering patients on prophylactic norfloxacin, infection resolution was also similar (100% vs 83.3%, 95% CI: -0.04 to 0.37, p NS). No adverse events were observed in either of the two groups. The cost of antibiotics was statistically lower in the amoxicillin-clavulanic acid group (p<0.001). CONCLUSIONS: Amoxicillin-clavulanic acid is as effective as cefotaxime in the treatment of bacterial infections in cirrhotic patients, but is less expensive and can be administered orally. These results suggest that amoxicillin-clavulanic acid is an effective alternative to cefotaxime for the empirical treatment of bacterial infections in cirrhosis.

Aged↗

[Clinical evaluation of a ticarcillin-clavulanic acid combination in severe infections in adults].

Timentin (ticarcillin (TCR) + clavulanic acid (AC)) was given for severe bacterial infections to sixteen hospitalized patients (10 male and 6 female; 16 to 75 years of age; normal renal function in 12). Infections included 8 septicemias (of which 4 were secondary to pyelonephritis), 6 pyelonephritis (in addition to the four above-mentioned cases), and 3 suppurated cellulitis of the lower limbs (with septicemia in one case). The following bacteria were recovered: 10 Escherichia coli, 1 Pseudomonas aeruginosa, 1 Enterobacter cloacae, 1 Providencia stuartii, 1 Salmonella typhi, 1 Klebsiella pneumoniae, and 1 Staphylococcus aureus. The sixteen strains were all susceptible to timentin (MICs determined by agar dilution: TCR + AC 4 mg/l: 0.5-16 mg/l; TCR + AC 8 mg/l: 0.2-16 mg/l). Thirteen strains were susceptible to TCR (MIC less than or equal to 16 mg/l), and three (1 E. coli, 1 K. pneumoniae, and 1 S. aureus) were resistant to TCR (MIC greater than or equal to 256 mg/l). 14 patients received timentin alone, while two were also given dibekacin. Timentin was given in one-hour IV infusions in a dosage of 9.6 g/24 h (3.2 g X 3) in 10 patients and 6.4 g/24 h (3.2 g X 2) in 6. Duration of therapy was 14 to 16 days in half of cases (range 5 to 21 days). At termination of the infusion, serum concentrations of ticarcillin and clavulanic acid (determined in ten patients) were greater than 50 mg/l and 3-7.4 mg/l respectively, and serum bactericidal activity (evaluated in ten cases) was consistently less than 1/2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Clavulanic acid inhibition of beta-lactamase I from Bacillus cereus 569/H.

Inactivation of beta-lactamase I by clavulanic acid was investigated. Clavulanic acid induced inhibition of the enzyme was found to be progressive with time. Benzylpenicillin provided protection against the adverse effects of the inhibitor initially, however, the enzyme was irreversibly inhibited in a progressive manner even in the presence of substrate. Reaction of beta-lactamase I with clavulanic acid, in the presence of ampicillin, led to a very rapid inactivation of the enzyme.

Ampicillin↗