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PubMed2005

[Effect of lat disruption on clavulanic acid production].

A 1.8kb fragment of lat was obtained from Streptomyces clavuligerus 27064, and replacement plasmid of pXAL1 and pXAL2 were constructed. PXAL1 and pXAL2 were used to disrupt the lat gene by bi-parental conjugation from E. coli to Streptomyces clavuligerus. A Am(r)Thio(S) transformant, named as XAL863, was obtained. The genome of Streptomyces clavuligerus 27064 and XAL863 was analyzed by southern blot technique, and the activity of lysine epsilon-aminotransferase in the two strains was also tested. Both results proved that the lat was disrupted in the XAL863. Streptomyces clavuligerus and XAL863 were cultured in the shaken flask respectively, and the production of clavulanic acid was analyzed by HPLC with the different incubation time interval, and the yield was approximately 1.8 times higher in the XAL863 at their highest production point.

Anti-Bacterial Agents↗
PubMed1982

Complementary activity of mezlocillin and the combination of amoxicillin with clavulanic acid on Enterobacteriaceae.

The MICs of amoxicillin, mezlocillin and BRL 25,000, a combination of two parts amoxicillin and one part clavulanic acid (2AM + 1CA), were measured for 331 Enterobacteriaceae strains which produced beta-lactamases as demonstrated by nitrocefin. The MIC values for mezlocillin and the combination 2AM + 1CA were very similar for the total number of the strains investigated. When investigated separately according to the bacterial species, three different sensitivity groups were established for the above-mentioned preparations: 1) species with the same or similar sensitivity to mezlocillin and 2AM + 1CA (Escherichia coli and Shigella spp., amoxicillin-resistant strains); 2) species which were more sensitive to mezlocillin than to the combination 2AM + 1CA (Citrobacter spp., Enterobacter cloacae, Serratia spp. and indole-positive Proteus as well as strains of E. coli and Shigella spp. which produce a cephalosporinase and are sensitive to amoxicillin); 3) species which are more sensitive to 2AM + 1CA than to mezlocillin (amoxicillin-resistant Salmonella spp., Proteus mirabilis and Klebsiella pneumoniae). This complementary activity of mezlocillin and 2AM + 1CA against Enterobacteriaceae depended on the beta-lactamases produced.

Amoxicillin↗
PubMed1999

[In vitro demonstration of a true post-beta-lactamases inhibitor effect (PLIE) of clavulanic acid on Klebsiella pneumoniae and Haemophilus influenzae].

In vivo, serum concentrations of beta-lactamase inhibitors measured during the last part of the dosing interval are below the levels associated with in vitro activity. Nevertheless, beta-lactam plus beta-lactamase inhibitor combinations remain active in vivo throughout the dosing interval. One of the many reasons for this contradiction may be the PLIE. The PLIE can be evaluated only in the light of the postantibiotic effect (PAE). Also, accurate determination of the PLIE requires a careful investigation of all bacterial regrowth delays (BRDs) inherent to the technical procedures used. The purpose of the study reported herein was to determine the true in vitro PLIE of clavulanic acid (CA) against two beta-lactamase-producing strains, a Klebsiella pneumoniae strain (amoxicillin [AMX] MIC > 256 mg/L; CA MIC = 64 mg/L; and AMX + CA MIX = 4 mg/L) and a Haemophilus influenzae strain (AMX MIC = 32 mg/L; CA > 32 mg/L; AMX-CA = 1 mg/L). For each strain, a stationary phase inoculum of 10(7) was preexposed for 2 h to either CA alone or CA + AMX in various concentrations. Dilution to 10(-2) or 10(-3) was performed to eliminate the CA and/or AMX after the preexposition phase. Hourly bacterial counts were done between 0 and 8 h and after 24 h. Control cultures exposed to AMX after dilution showed a growth delay possibly ascribable to the time needed for bacteria to produce a large enough amount of beta-lactamases. Control experiments were done to unequivocally differentiate PLIE from PAE and BRD. The true PLIE values thus obtained ranged from 0 to 4.5 h for K. pneumoniae and from 0 to 15 h for H. influenzae. For both strains, a PLIE was demonstrated after exposure to CA alone.

Amoxicillin↗
PubMed1988

[Sensitivity to an amoxicillin-clavulanic acid combination, of deep tonsillar flora isolated in chronic tonsillitis].

Deep tonsillar flora were identified in tonsils removed from 48 patients, children and adults, with chronic tonsillitis and recurrent sore throats or obstructive hypertrophy. Most specimens (38/48) cultured multiple germs (2 to 5 different species) with aerobic and anaerobic Gram+ and Gram-forms, some being beta-lactamase producers. Of the total of 135 strains isolated, 104 were aerobic and 31 anaerobic. The species of aerobic germs most frequently isolated were: Apart from alpha-hemolytic streptococci of undertermined group (38 strains), Haemophilus sp. : 14 (including 3 beta-lactamase + strains), Staphylococcus aureus: 15 (including 11 beta-lactamase + strains), Streptococcus A : 10, Enterobacteriaceae : 6, Neisseria sp. : 8 (including 1 beta-lactamase + strain). And among the anaerobic germs: Peptococcus : 3, Veillonella alc : 10, Fusobacterium nucleatum : 9, Bacteroides melaninogenicus : 6, Other Bacteroides : 2. Of the 127 strains tested, 102 were sensitive to amoxicillin and 121 to amoxicillin and clavulanic acid combination. The presence of a beta-lactamase producing bacterium in 1 of 3 specimens suggests the risk of failure of treatment with penicillin, prescribed classically for this type of affection.

Adolescent↗
PubMed1994

Prediction of piperacillin-tazobactam susceptibility among Enterobacteriaceae, Pseudomonas aeruginosa, and other bacteria using ticarcillin-clavulanic acid, ceftazidime, and other broad-spectrum antimicrobial in vitro test results.

The ability of various in vitro beta-lactam susceptibility test results to predict the susceptibility of piperacillin-tazobactam (a new beta-lactam-beta-lactamase inhibitor combination) was assessed using more than 46,000 recent clinical isolates. The organisms were tested by reference-quality National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution procedures and interpreted by the currently published NCCLS criteria. The recommended antimicrobial tests that would accurately predict the piperacillin-tazobactam in vitro efficacy had an overall very major, false-susceptible rate of only 0.6% (< or = 1.5% is acceptable). The following drug tests can be used to judge piperacillin-tazobactam activity and spectrum (low patient risk) conservatively: for Enterobacteriaceae use ticarcillin-clavulanic acid results (0.6% very major error); for Pseudomonas aeruginosa use piperacillin (0.1%) results; for enterococci use ampicillin or ampicillin-sulbactam (1.8%) results; for Haemophilus influenzae and Moraxella catarrhalis use cefotaxime or cefuroxime or ceftriaxone (1.5%); and for staphylococci use oxacillin by NCCLS recommendations. When the piperacillin-tazobactam testing reagents become available, the direct testing of this combination should be applied to relevant clinical isolates. The piperacillin-tazobactam break points should be reassessed as indicated by the cited minimum inhibitory concentration population analysis to improve predictive accuracy; H. influenzae susceptibility modified to < or = 2/4 micrograms/ml and Enterococcus species susceptibility tested at < or = 16/4 micrograms.

Anti-Bacterial Agents↗
PubMedDate not supplied

Recurrent immuno-allergic hepatitis related to amoxicillin-clavulanic acid.

We report on a patient who presented, on 2 occasions at one-year interval after a treatment with the amoxicillin-clavulanic acid association, a clinical and biological picture in keeping with the diagnosis of immuno-allergic hepatocellular hepatitis. On liver biopsies, the most characteristic finding was portal and lobular eosinophilic infiltration without cholestasis and biliary ducts damage.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed1991

Antibiotic therapy of intra-abdominal sepsis in the elderly: experience with ticarcillin and clavulanic acid.

Age is a major factor in determining the outcome for older patients with intra-abdominal sepsis. Poor outcome in these patients may be related to a number of physiologic and immunologic changes associated with aging. The treatment of intra-abdominal sepsis can itself pose special risks for the elderly. Standard regimens containing aminoglycosides have a substantial risk of nephrotoxicity, which is magnified in elderly patients. Alternatives to standard aminoglycoside-containing regimens, therefore, are desirable. Most intra-abdominal infections involve multiple pathogens, usually both aerobic and anaerobic. The polymicrobial nature of intra-abdominal sepsis mandates antimicrobial chemotherapy effective against a broad range of organisms. In the past several years, a host of new antibiotics have been introduced that used alone or in combination with other drugs has the potential of safely avoiding aminoglycosides in many patients with intra-abdominal sepsis. One such agent, ticarcillin with clavulanate potassium, is active against a wide spectrum of aerobic and anaerobic pathogens. In a prospective, randomized, open label trial, ticarcillin and clavulanate was compared with gentamicin and clindamycin. Although the sample size was too small to allow meaningful statistical comparisons of efficacy and safety, both regimens were effective and well tolerated. In general, prolonged administration of aminoglycosides is rarely indicated for the treatment of intra-abdominal sepsis in the elderly, although initial empiric use of aminoglycosides may sometimes be warranted.

Age Factors↗
PubMed1986

Augmentin (amoxycillin-clavulanic acid) compared with amoxycillin alone in the treatment of urinary tract infections in the elderly.

Sixty-seven patients (mean age 82 years) with urinary tract infection were treated with either Augmentin or amoxycillin in a double-blind randomised trial. Of the 52 patients who completed 5 days treatment, 21/24 (87.5%) responded to Augmentin but only 12/28 (43%) responded to amoxycillin. Five of eight patients who had failed to respond to amoxycillin responded to Augmentin.

Aged↗
PubMed1987

In vitro susceptibility of Mycobacterium tuberculosis, Mycobacterium africanum, Mycobacterium bovis, Mycobacterium avium, Mycobacterium fortuitum, and Mycobacterium chelonae to ticarcillin in combination with clavulanic acid.

The in vitro susceptibility of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium africanum, Mycobacterium avium, Mycobacterium fortuitum, and Mycobacterium chelonae (M. chelonei) to ticarcillin in combination with calvulanic acid (CA) was studied by the agar dilution method. All the M. tuberculosis, M. bovis, and M. africanum strains were inhibited at a ticarcillin concentration of 32 micrograms/ml or lower in combination with 5 micrograms of CA. M. chelonae and M. avium strains proved resistant to more than 128 micrograms of ticarcillin plus 5 micrograms of CA per ml. M. fortuitum strains needed 128 micrograms of ticarcillin plus 5 micrograms of CA to inhibit approximately 30% of the isolates.

Clavulanic Acid↗
PubMed1994

[A new therapeutic strategy using a ofloxacin-amoxicillin-clavulanic acid combination in the treatment of upper gynecologic infections. Apropos of 123 cases].

OBJECTIVE: To evaluate a new antibiotic strategy with a combination of ofloxacin + co-amoxiclav in the treatment of pelvic infectious diseases. DESIGN: An open-non-comparative multicentre (10) study. SUBJECTS: 123 patients (118 salpingitis and 5 endometritis) were included clinical, laparoscopic and bacteriological assessments were performed before treatment and a laparoscopic control was done in 35% of cases. Among positive bacteriological samples before treatment 48.7% C. trachomatis were isolated; 56.1% of salpingitis were considered as severe (COGIT score > 6). TREATMENT: Patients received at entry oral ofloxacin 200 mg bid in combination with parenteral co-amoxiclav 2 to 4 g following by oral route. Total duration of treatment was 21 days. RESULTS: With respectively 97.2% and 91.6% satisfactory clinical and bacteriological results, this combination should take a major place in the treatment of pelvic infectious diseases.

Adolescent↗
PubMed1997

Molecular diversity and evolution of blaTEM genes encoding beta-lactamases resistant to clavulanic acid in clinical E. coli.

The molecular diversity of inhibitor-resistant TEM (IRT) enzymes was explored using a strategy which involved DNA amplification by polymerase chain reaction (PCR), analysis of restriction fragment length polymorphism (RFLP), and direct nucleotide sequencing. The study of plasmid-borne genes from 27 strains, resistant to amoxicillin and beta-lactamase-inhibitor combinations, identified mutations resulting in amino acid change at positions 69, 244, 275, and 276 known to be associated with the IRT phenotype and a mutation at nucleotide position 162 in the promoter region. These mutations were found to lie on two different gene sequences, described here as "TEM-1B like" and "TEM-2 like" restriction linkage groups. Further analysis, of nucleotide sequences of promoter and coding regions of the beta-lactamases, confirmed that a given mutation causing IRT phenotype could be associated with two different gene sequence frameworks and two different causal mutations could lie on identical gene sequence framework. These data argue in favor of convergent phenotypic evolution of IRT enzymes under the selective pressure imposed by the intensive clinical use of beta-lactam-beta-lactamase inhibitor combinations.

Amoxicillin↗
PubMedDate not supplied

[Amoxycillin-clavulanic acid and cefuroxime axetil in the treatment of acute sinusitis. A clinical, radiological and bacteriological evaluation].

Cefuroxime axetil (CAE), an orally absorbed product of cefuroxime, and amoxycillin/clavulanate (AAC), were evaluated for their efficacy and safety in the treatment of acute sinusitis. A total of 47 patients were enrolled in a randomized study to compare cefuroxime axetil 500 mg. b.d. for 8 days (25 patients) with amoxycillin/clavulanate 500 mg. t.d.s for 8 days (22 patients). All patients were evaluable for clinical, radiological and bacteriological response. Of 25 clinically assessable patients treated with CAE, 24 were cured, 1 improved and 1 relapsed (96% success rate). Of 22 assessable patients given AAC, 14 were cured and 8 improved (100% success rate). Two out of 25 (8%) patients treated with CAE experienced drug-related adverse events, including 4% with diarrhoea. In the AAC group, 3 out of 22 (13%) patients had a drug-related adverse event, including 13% with diarrhoea. In conclusion, CAE appears to be as safe and effective as AAC in the treatment of acute sinusitis.

Acute Disease↗
PubMed1987

A comparative trial of moxalactam plus ticarcillin and clavulanic acid or piperacillin as empiric antibiotic therapy for febrile cancer patients.

Resistance of bacteria to beta-lactam antibiotics remains a difficult clinical problem that can be compounded in infected patients with serious underlying illness, especially those who are immunocompromised. In a prospective randomized safety and efficacy trial, febrile cancer patients received either ticarcillin disodium combined with the beta-lactamase inhibitor clavulante potassium (Timentin, Beecham Laboratories, Bristol, TN) plus moxalactam (T+M), or piperacillin plus moxalactam (P+M) as initial empiric antimicrobial therapy. Sixty-six febrile episodes in 53 patients were studied. In the T+M group, 14 (78%) of 18 clinically evaluable infections in patients with profound granulocytopenia improved as did all 14 (100%) such infections in the P+M group. In the T+M group 17 of 21 (81%) similarly evaluable infections improved irrespective of granulocyte count, as did 14 (88%) of 16 of such infections in the P+M group. These results are not statistically significantly different. Serious side effects were infrequent and comparable with both regimens. There was one antibiotic related hemorrhage in the P+M group and a serious episode of nephrotoxicity in a patient who died without recovering renal function in the T+M group. These results suggest that the overall safety and efficacy of Timentin plus moxalactam, and piperacillin plus moxalactam are comparable and similar to previous empiric antibiotic trials.

Bacterial Infections↗
PubMed1983

Prevention of wound sepsis in amputations by peri-operative antibiotic cover with an amoxycillin-clavulanic acid combination.

In a series of 44 patients with lower limb ischaemia requiring amputation for major limb sepsis, the performance of a new antibiotic combination with beta-lactamase-inhibiting properties, amoxycillin plus clavulanic acid (A-CA) (Augmentin; Beecham), was compared with that of penicillin in the prevention of wound infection. The sepsis rate of 12,9% in the group of patients receiving peri-operative A-CA was significantly lower than the 76,9% in the penicillin control group (x2 = 14,48; P less than 0,001). It is concluded that there is a need for peri-operative antibiotic cover in this situation and that A-CA appears to be highly effective. No statistical difference was found as regards development of sepsis in wounds closed primarily or left open while under A-CA cover.

Adult↗
PubMed2002

[Sinusal penetration of amoxicillin-clavulanic acid. Formulation 1 g./125 mg., twice daily versus formulation 500 mg./125 mg., three times daily].

INTRODUCTION: In order to meet the evolution of pneumococcus resistance to beta-lactam antibiotics, a new formulation of amoxicillin (AMX) and clavulanic acid (CA), with twice as much AMX (1 g/125 mg vs. 500 mg/125 mg) was developed for the treatment of acute pneumonia in patients at risk. This formulation can also be used in the treatment of acute maxillary sinusitis using a 1 g/125 mg regimen twice-daily. OBJECTIVES: Compare the sinusal penetration of AMX and CA (1 g/125 mg twice-daily vs. 500 mg/125 mg three times a day) when administered at both regimens to demonstrate equivalent pharmacokinetic and pharmacodynamic behaviour of the former when compared to the latter. METHODS: Concentrations of AMX and CA were measured in the anterior ethmoid, maxillary, posterior ethmoid sinus and in the middle nasa concha in 62 patients undergoing surgery for nasosinusal polyps. Patients randomised in two groups corresponding to 2 oral regimens, received either 1 g/125 mg twice a day or 500 mg/125 mg three times a day for 4 days. The last dose in both groups was administered 1 h 30, 3, 5 or 8 hrs prior to surgery. Serum samples were taken simultaneously to tissue samples. AMX and CA were measured by high performance liquid chromatography. Exogenous and above all endogenous blood contamination were taken into account with the hematocrit as well as blood and tissue haemoglobin concentrations. Comparisons of tissue concentrations were made for each sampling time, according to values obtained for a specific tissue with both doses on one hand, and on the other to values obtained with a specific dose in different tissues. The calculated pharmacodynamic parameters, which are considered to be predictive for bacteriological and clinical efficacy, result directly from tissue concentrations of AMX. tissue inhibitory quotients (IQtissue = Tissue concentration/MIC). time above MICs for serum and tissue concentrations (T > MIC). RESULTS: As regards AMX, whatever the dose, at 1 h 30 and at 3 hrs, tissue concentrations did not differ significantly whatever the tissue studied (from 1.1 to 2.5 micrograms/g). Conversely, at 5 and 8 hrs, they were greater than after the 1 g/125 mg regimen given twice-daily (0.06-0.7 vs. 0.7-1.8 micrograms/g). If we consider a given dose, the comparison between the various tissues showed identical concentrations in the four tissues studied at each sampling time, except in two cases with the dose of 500 mg/125 mg 3 times a day. T > MIC for serum and tissue showed higher values than those required for AMX/pneumococcus association (40-50%) with, nevertheless, greater tissue values for the 1 g/125 mg dose given twice-daily when MIC was of 1 microgram/ml (40-52% vs. 50-66%). The maximum tissue inhibitory quotients were also greater with the twice-daily 1 g/125 mg dose, when calculated with MIC 50 or 90 of S. Pneumoniae, H. influenzae, M. catarrhalis or S. pyogenes. As for CA, concentrations were equivalent for both doses at each sampling time and greater than those required in vitro during respectively 4 and 5 hours for beta-lactamases H. influenzae and M. catarrhalis. DISCUSSION-CONCLUSION: A least an equivalence between both dose regimens was observed, with occasionally a superiority of the twice-daily 1 g/125 mg dose, in terms of pharmacokinetics, tissue penetration and pharmacodynamics for both AMX and CA. This new regimen therefore appears more appropriate for the treatment of acute maxillary sinusitis in adults.

Acute Disease↗
PubMed2004

Effect of amoxicillin-clavulanic acid on human fecal flora in a gnotobiotic mouse model assessed with fluorescence hybridization using group-specific 16S rRNA probes in combination with flow cytometry.

Predominant groups of bacteria from a human fecal flora-associated mouse model challenged with amoxicillin-clavulanic acid were quantified with fluorescence in situ hybridization combined with flow cytometry using specific 16S rRNA targeted oligonucleotide probes. This approach provides a useful tool with high throughput to evaluate fecal microflora under antibiotic treatment.

Amoxicillin-Potassium Clavulanate Combination↗