Ampicillin

molecular genetics, bacteriology, tissue culture Inhibits cell-wall synthesis by interfering with peptidoglycan cross-linking working concentration for stringent plasmids is 20μg/ml working concentration for relaxed plasmids is 50μg/ml store at 4°C, warm to room temperature before using

Adsorption and release of ampicillin antibiotic from ordered mesoporous silica.[Pubmed:28285049]

J Colloid Interface Sci. 2017 Jul 1;497:217-225.

In this work the adsorption and the release of Ampicillin - a beta-lactam penicillin-like antibiotic - from MCM-41, SBA-15, and (amino functionalized) SBA-15-NH2 ordered mesoporous silica (OMS) materials were investigated. The silica matrices differ for their pore size (SBA-15 vs. MCM-41) mainly, and also for surface charge (SBA-15 and MCM-41, vs. SBA-15-NH2). OMS samples were characterized through small-angle X-rays scattering (SAXS), transmission electron microscopy (TEM), N2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and potentiometric titrations. The quantification of immobilized and released Ampicillin was monitored by mean of UV-Vis spectroscopy. Experimental adsorption isotherms evidenced that Ampicillin's loading is not related to the pore size (dBJH) of the adsorbent. Indeed the maximal loadings were 237mg/g for SBA-15 (dBJH=6.5nm), 278mg/g for MCM-41 (dBJH=2.2nm), and 333mg/g for SBA-15-NH2 (dBJH=5.6nm). Loading seems, instead, to be related to the surface charge density (sigma) of the sorbent surface. Indeed, at pH 7.4 Ampicillin drug is negatively charged and likely prefers to interact with SBA-15-NH2 (sigmaSBA-15-NH2=+0.223Cm(-2)) rather than the slightly negatively charged silicas (sigmaSBA-15=-0.044Cm(-2) and sigmaMCM-41=-0.033Cm(-2)). Similarly, Ampicillin release is affected by interfacial interactions. Indeed, we found a burst release from pure silica samples (SBA-15 and MCM-41), whereas a sustained one from SBA-15-NH2 sample. We explain this behavior as a result of an attractive interaction between the protonated amino group of SBA-15-NH2 and the negatively charged carboxylate group of Ampicillin. In summary, in order to obtain a sustained drug release, the chemical nature of the matrix's surface plays a role which is more important than its textural features. SBA-15-NH2 matrix is hence a suitable candidate for local sustained release of antibiotic drugs.

Efficacy of Telavancin Alone and in Combination with Ampicillin in a Rat Model of Enterococcus faecalis Endocarditis.[Pubmed:28320712]

Antimicrob Agents Chemother. 2017 May 24;61(6). pii: AAC.02489-16.

We first assessed telavancin (TLV) pharmacokinetics in rats after a single subcutaneous dose of 35 mg/kg of body weight. The pharmacokinetic data were used to predict a TLV dose that simulates human exposure, and the efficacy of TLV was then evaluated using a TLV dose of 21 mg/kg every 12 h against Enterococcus faecalis OG1RF (TLV MIC of 0.06 mug/ml) in a rat endocarditis model with an indwelling catheter. Therapy was given for 3 days with TLV, daptomycin (DAP), or Ampicillin (AMP) monotherapy and with combinations of TLV plus AMP, AMP plus gentamicin (GEN), and AMP plus ceftriaxone (CRO); rats were sacrificed 24 h after the last dose. Antibiotics were given to simulate clinically relevant concentrations or as used in other studies. TLV treatment resulted in a significant decrease in bacterial burden (CFU per gram) in vegetations from 6.0 log10 at time 0 to 3.1 log10 after 3 days of therapy. Bacterial burdens in vegetations were also significantly lower in the TLV-treated rats than in the AMP (P = 0.0009)- and AMP-plus-GEN (P = 0.035)-treated rats but were not significantly different from that of the AMP-plus-CRO-treated rats. Bacterial burdens from vegetations in TLV monotherapy and TLV-plus-AMP-and-DAP groups were similar to each other (P >/= 0.05). Our data suggest that further study of TLV as a therapeutic alternative for deep-seated infections caused by vancomycin-susceptible E. faecalis is warranted.

Indole-Induced Activities of beta-Lactamase and Efflux Pump Confer Ampicillin Resistance in Pseudomonas putida KT2440.[Pubmed:28352264]

Front Microbiol. 2017 Mar 14;8:433.

Indole, which is widespread in microbial communities, has received attention because of its effects on bacterial physiology. Pseudomonas putida and Pseudomonas aeruginosa can acquire Ampicillin (Amp) resistance during growth on indole-Amp agar. Transcriptome, mutant, and inhibitor studies have suggested that Amp resistance induced by indole can be attributed to increased gene expression of ttgAB encoding two genes of RND-type multidrug efflux operons and an ampC encoding beta-lactamase. Expression, enzyme activities, and mutational analyses indicated that AmpC beta-lactamase is important for acquiring Amp resistance of P. putida in the presence of indole. Here, we show, for the first time, that volatile indole increased Amp-resistant cells. Consistent with results of the volatile indole assay, a low concentration of indole in liquid culture promoted growth initially, but led to mutagenesis after indole was depleted, which could not be observed at high indole concentrations. Interestingly, ttgAB and ampC gene expression levels correlate with the concentration of indole, which might explain the low number of Amp-mutated cells in high indole concentrations. The expression levels of genes involved in mutagenesis, namely rpoS, recA, and mutS, were also modulated by indole. Our data indicates that indole reduces Amp-induced heterogeneity by promoting expression of TtgABC or MexAB-OprM efflux pumps and the indole-induced beta-lactamase in P. putida and P. aeruginosa.

Recurrent trimethoprim-sulfamethoxazole-induced aseptic meningitis with associated ampicillin-induced myoclonic twitches.[Pubmed:28291512]

Int J Clin Pharmacol Ther. 2017 Jul;55(7):627-629.

OBJECTIVE: To report a case of recurrent trimethoprim-sulfamethoxazole-induced aseptic meningitis with associated Ampicillin-induced myoclonic twitches. MATERIALS AND METHODS: The patient was investigated using cerebral computed tomography, magnetic resonance imaging, cerebrospinal fluid examination, and electroencephalography. Written informed consent was obtained from the patient for access to clinical files for research purposes and publication. RESULTS: We present a middle-aged woman with two recurrent episodes of aseptic meningitis after treatment with trimethoprim-sulfamethoxazole. Additionally, she developed myoclonic twitches as a rare side effect of Ampicillin. CONCLUSION: Aseptic meningitis is a rare adverse reaction to medications like antibiotics. The pathogenesis of trimethoprim-sulfamethoxazole-induced aseptic meningitis is not yet completely understood, but an immune-mediated hypersensitivity reaction is suspected. If patients with an antibiotic therapy due to a systemic or local infection present with severe headache, not only common diagnosis of a parainfectious headache, but also antibiotic-induced aseptic meningitis should be considered..