scholarly journals In vitro assessment of the effect of clavulanic acid at concentrations achieved in human serum on the bactericidal activity of amoxicillin at physiological concentrations against Staphylococcus aureus: implications for dosage regimens.

1997 ◽  
Vol 41 (6) ◽  
pp. 1403-1405 ◽  
Author(s):  
L Aguilar ◽  
M Martín ◽  
I P Balcabao ◽  
M L Gómez-Lus ◽  
R Dal-Ré ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Human Serum ◽  
Clavulanic Acid ◽  
Beta Lactamase ◽  
Postantibiotic Effect ◽  
Initial Inoculum ◽  
Dosage Regimens ◽  
Amoxicillin Clavulanic Acid ◽  
In Vitro Assessment

The effects on Staphylococcus aureus viability and beta-lactamase activity of concentrations that simulated those in human serum after a combined dose of 875 mg of amoxicillin and 125 mg of clavulanic acid were studied in an in vitro pharmacodynamic model. Six hours of preexposure to concentrations of the amoxicillin-clavulanic acid combination that were higher than the amoxicillin-clavulanic acid MIC led to a reduction of the initial inoculum of >90% and to a significant decrease of beta-lactamase activity versus those of the control even from 6 h, when concentrations were subinhibitory. The postantibiotic effect and post-beta-lactamase inhibitor effect contributed to these results.

scholarly journals In Vitro Activities of Co-Amoxiclav at Concentrations Achieved in Human Serum against the Resistant Subpopulation of Heteroresistant Staphylococcus aureus: a Controlled Study with Vancomycin

1998 ◽  
Vol 42 (7) ◽  
pp. 1574-1577 ◽  
Author(s):  
J. Prieto ◽  
L. Aguilar ◽  
M. J. Giménez ◽  
D. Toro ◽  
M. L. Gómez-Lus ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Human Serum ◽  
Clavulanic Acid ◽  
Bacterial Population ◽  
Controlled Study ◽  
Initial Inoculum ◽  
Amoxicillin Clavulanic Acid ◽  
And Control ◽  
Over Time

The effects of concentrations that simulated those in human serum after a single intravenous dose of amoxicillin (2 g), amoxicillin-clavulanic acid (2,000 and 200 mg, respectively), or vancomycin (500 mg), on the viability and β-lactamase activity of two isogenic (β-lactamase and non-β-lactamase producer) heteroresistant Staphylococcus aureus strains were studied in an in vitro pharmacodynamic model. A reduction of ≥97% of the initial inoculum was obtained with vancomycin and amoxicillin-clavulanic acid against both strains, with respect to the total bacterial population and the oxacillin-resistant subpopulation. The same pattern was observed with amoxicillin and the β-lactamase-negative strain. β-Lactamase activity in the β-lactamase-positive strain changed over time parallel to viability, decreasing with amoxicillin-clavulanic acid or vancomycin and increasing in the amoxicillin and control groups. Clavulanic acid concentrations achievable in serum that changed over time allowed amoxicillin to act against the β-lactamase-producing methicillin-resistant S. aureus to a similar extent as vancomycin.

scholarly journals The Antistaphylococcal Activity of Amoxicillin/Clavulanic Acid, Gentamicin, and 1,8-Cineole Alone or in Combination and Their Efficacy through a Rabbit Model of Methicillin-Resistant Staphylococcus aureus Osteomyelitis

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Soukayna Hriouech ◽  
Ahmed A. Akhmouch ◽  
Aouatef Mzabi ◽  
Hanane Chefchaou ◽  
Mariam Tanghort ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bone Marrow ◽  
Synergistic Effect ◽  
Clavulanic Acid ◽  
Rabbit Model ◽  
Methicillin Resistant ◽  
Antistaphylococcal Activity ◽  
Amoxicillin Clavulanic Acid

The aim of this research paper is to test the antistaphylococcal effect of 1,8-cineole, amoxicillin/clavulanic acid (AMC), and gentamicin, either separately or in combination against three Staphylococcus aureus strains isolated from patients suffering from osteomyelitis. This activity was tested in vitro by using the microdilution method and the checkerboard assay. The efficacy of these three antibacterial agents was then tested in vivo by using an experimental model of methicillin-resistant S. aureus osteomyelitis in rabbits. This efficacy was assessed after four days of treatment by counting the number of bacteria in the bone marrow. The obtained results in vitro showed that the combination of the AMC with gentamicin did not induce a synergistic effect, whereas the combination of the two antibiotics with 1,8-cineole did. This effect is stronger when AMC is combined with 1,8-cineole as a total synergistic effect was obtained on the three strains used (FIC ≤ 0.5). In vivo, a significant reduction was noted in the number of colonies in the bone marrow when rabbits were treated with AMC associated with either 1,8-cineole or gentamicin compared to rabbits treated with AMC, gentamicin, or 1,8-cineole alone. These results demonstrated that 1,8-cineole showed a synergistic effect in combination with both AMC and gentamicin, which offer possibilities for reducing antibiotic usage. Also, the AMC associated with 1,8-cineole could be used to treat MRSA osteomyelitis.

scholarly journals Antimicrobial susceptibilities of Campylobacter jejuni and Campylobacter coli to 12 beta-lactam agents and combinations with beta-lactamase inhibitors.

1996 ◽  
Vol 40 (8) ◽  
pp. 1924-1925 ◽  
Author(s):  
P Tajada ◽  
J L Gomez-Graces ◽  
J I Alós ◽  
D Balas ◽  
R Cogollos
Keyword(s):  
Clavulanic Acid ◽  
Susceptibility Testing ◽  
Campylobacter Coli ◽  
Beta Lactamase ◽  
In Vitro Activity ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Thermophilic Campylobacter ◽  
Amoxicillin Clavulanic Acid

The in vitro activities of 12 beta-lactam agents against 100 thermophilic Campylobacter strains were tested. Beta-Lactamase production was detected in 88% of all strains tested. Clavulanic acid was the best inhibitor by susceptibility testing. The beta-lactams which displayed high levels of in vitro activity against Campylobacter isolates were imipenem, amoxicillin-clavulanic acid, and cefepime and, to a lesser degree, amoxicillin, ampicillin, and cefotaxime.

scholarly journals Evaluation of amoxicillin-clavulanic acid resistance in the Bifidobacterium genus

2021 ◽  
Author(s):  
Leonardo Mancabelli ◽  
Walter Mancino ◽  
Gabriele Andrea Lugli ◽  
Chiara Argentini ◽  
Giulia Longhi ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Clavulanic Acid ◽  
Acid Resistance ◽  
Resistance Mechanisms ◽  
Western World ◽  
Beneficial Effects ◽  
Amoxicillin Clavulanic Acid ◽  
High Level ◽  
The Impact

Amoxicillin-Clavulanic acid (AMC) is one of the most frequently prescribed antibiotic formulations in the Western world. Extensive oral use of this antimicrobial combination influences the gut microbiota. One of the most abundant early colonizers of the human gut microbiota is represented by different taxa of the Bifidobacterium genus, which include many members that are considered to bestow beneficial effects upon their host. In the current study, we investigated the impact of AMC administration on the gut microbiota composition, comparing the gut microbiota of 23 children that had undergone AMC antibiotic therapy to that of 19 children that had not been treated with antibiotics during the preceding six months. Moreover, we evaluated AMC sensitivity by Minimal Inhibitory Concentration (MIC) test of 261 bifidobacterial strains, including reference strains for the currently recognized 64 bifidobacterial (sub)species, as well as 197 bifidobacterial isolates of human origin. These assessments allowed the identification of four bifidobacterial strains, which exhibit a high level of AMC insensitivity, and which were subjected to genomic and transcriptomic analyses to identify the putative genetic determinants responsible for this AMC insensitivity. Furthermore, we investigated the ecological role of AMC-resistant bifidobacterial strains by in vitro batch-cultures. Importance Based on our results, we observed a drastic reduction in gut microbiota diversity of children treated with antibiotics, also affecting the abundance of Bifidobacterium, a bacterial genus commonly found in the infant gut. MIC experiments revealed that more than 98% of bifidobacterial strains tested were shown to be inhibited by the AMC antibiotic. Isolation of four insensitive strains and sequencing of their genome revealed the identity of possible genes involved in AMC resistance mechanisms. Moreover, gut-simulating in-vitro experiments revealed that one strain, i.e. B. breve PRL2020, is able to persist in the presence of a complex microbiota combined with AMC antibiotic.

scholarly journals Novel Antibiotic Combinations of Diverse Subclasses for Effective Suppression of Extensively Drug-Resistant Methicillin-Resistant Staphylococcus aureus (MRSA)

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shumyila Nasir ◽  
Muhammad Sufyan Vohra ◽  
Danish Gul ◽  
Umm E Swaiba ◽  
Maira Aleem ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clavulanic Acid ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
Methicillin Resistant ◽  
Development Of Resistance ◽  
Amoxicillin Clavulanic Acid ◽  
Combination Antibiotics ◽  
Time Kill

The emergence of multidrug-resistant pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), the chief etiological agent for a range of refractory infections, has rendered all β-lactams ineffective against it. The treatment process is further complicated with the development of resistance to glycopeptides, primary antibiotics for treatment of MRSA. Antibiotic combination therapy with existing antimicrobial agents may provide an immediate treatment option. Minimum inhibitory concentrations (MICs) of 18 different commercially available antibiotics were determined along with their 90 possible pairwise combinations and 64 triple combinations to filter out 5 best combinations. Time-Kill kinetics of these combinations were then analyzed to find collateral bactericidal combinations which were then tested on other randomly selected MRSA isolates. Among the top 5 combinations including levofloxacin-ceftazidime; amoxicillin/clavulanic acid-tobramycin; amoxicillin/clavulanic acid-cephradine; amoxicillin/clavulanic acid-ofloxacin; and piperacillin/tazobactam-tobramycin, three combinations were found to be collaterally effective. Levofloxacin-ceftazidime acted synergistically in 80% of the tested clinical MRSA isolates. First-line β-lactams of lower generations can be used effectively against MRSA infection when used in combination. Antibiotics other than glycopeptides may still work in combination.

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