Degradation of ticarcillin by subcritical water oxidation method: Application of response surface methodology and artificial neural network modeling.

This study was performed to investigate the mineralization of ticarcillin in the artificially prepared aqueous solution presenting ticarcillin contaminated waters, which constitute a serious problem for human health. 81.99% of total organic carbon removal, 79.65% of chemical oxygen demand removal, and 94.35% of ticarcillin removal were achieved by using eco-friendly, time-saving, powerful and easy-applying, subcritical water oxidation method in the presence of a safe-to-use oxidizing agent, hydrogen peroxide. Central composite design, which belongs to the response surface methodology, was applied to design the degradation experiments, to optimize the methods, to evaluate the effects of the system variables, namely, temperature, hydrogen peroxide concentration, and treatment time, on the responses. In addition, theoretical equations were proposed in each removal processes. ANOVA tests were utilized to evaluate the reliability of the performed models. F values of 245.79, 88.74, and 48.22 were found for total organic carbon removal, chemical oxygen demand removal, and ticarcillin removal, respectively. Moreover, artificial neural network modeling was applied to estimate the response in each case and its prediction and optimizing performance was statistically examined and compared to the performance of central composite design.

Purification and biochemical characterization of IMP-13 metallo-beta-lactamase.

The IMP-13 metallo-ß-lactamase was overproduced in Escherichia coli BL21(DE3) and purified by chromatography. Analysis of kinetic parameters revealed some notable differences with other IMP-type enzymes, noteworthily a higher catalytic efficiency toward ticarcillin and piperacillin and a marked preference for imipenem over meropenem.

Enhancement of antibiotic susceptibility of Stenotrophomonas maltophilia using a polyclonal antibody developed against an ABC multidrug efflux pump.

Stenotrophomonas maltophilia is an emerging nosocomial pathogen capable of causing healthcare-associated infections, including pneumonia and bacteremia. Intrinsic resistance in S. maltophilia is exhibited towards many broad-spectrum antibiotics, and treatment recommendations are controversial. One of the major causes of antimicrobial resistance is attributed to a robust array of efflux pumps that extrude drug compounds from the cell. Using checkerboard and growth kinetic assays, we evaluated the in vitro activity of a polyclonal antibody raised against an ATP-binding cassette efflux protein in S. maltophilia. Six clinical strains of S. maltophilia and one type strain were challenged with co-trimoxazole, ticarcillin-clavulanate, and ciprofloxacin, alone and in combination with antibody. One clinical strain was tested by growth curve experiments for each antibiotic-antibody combination. The use of antibody resulted in significantly increased susceptibility in 71.4% (15/21) of treatments tested, with 33.3% displaying synergy and 38.1% an additive effect. In growth kinetic studies, synergy was obtained for each antibiotic-antibody combination. Thus, the use of antibody raised against multidrug efflux pumps for the treatment of multidrug-resistant organisms warrants further investigation. Antibody targeting substrate recognition sites, or other functionally important epitopes, may lead to inhibition of multiple efflux pumps that share the same substrate and is an attractive area that should be explored.

Heavy metal resistance and virulence profile in Pseudomonas aeruginosa isolated from Brazilian soils.

Pseudomonas aeruginosa is an opportunistic pathogen, which can have several virulence factors that confer on it the ability to cause severe, acute and chronic infections. Thus, the simultaneous occurrence of resistance to antibiotics and heavy metals associated with the presence of virulence genes is a potential threat to human health and environmental balance. This study aimed to investigate the resistance profile to heavy metals and the correlation of this phenotype of resistance to antimicrobials and to investigate the pathogenic potential of 46 P. aeruginosa isolates obtained from the soil of five Brazilian regions. The bacteria were evaluating for antimicrobial and heavy metal resistance, as well as the presence of plasmids and virulence genes. The isolates showed resistance to four different antibiotics and the majority (n = 44) had resistance to aztreonam or ticarcillin, furthermore, 32 isolates showed concomitant resistance to both of these antibiotics. A high prevalence of virulence genes was found, which highlights the pathogenic potential of the studied environmental isolates. Moreover, a high frequency of heavy metal resistance genes was also detected, however, the phenotypic results indicated that other genes and/or mechanisms should be related to heavy metal resistance.

Ticarcillin vs carbenicillin: clinical pharmacokinetics.

The pharmacokinetic characteristics of ticarcillin, a semisynthetic penicillin more active than carbenicillin against Pseudomonas, were compared to those of carbenicillin in 12 healthy volunteers. Following an intravenous infusion of 2 gm in 5 min, there was a lower average serum level for ticarcillin (218 mug/ml) than for carbenicillin (301 mug/ml), but after 2 hr the differences were not significant. The biologic half-life of ticarcillin was slightly longer than that of carbenicillin (72 and 65 min, P smaller than 0.01) and its volume of distribution was larger (15.7 and 12.3 l, P smaller than 0.01). Eighty-six per cent of the dose of ticarcillin and 99 percent of the dose of carbenicillin was recovered in the urine in 24 hr. Similar but much less marked blood level differences were noted with 2 gm, 30-min infusions. An intravenous infusion of 1 gm/hr gave average steady-state blood levels of about 124 mug/ml for both antibiotics. Probenecid, administered 1 hr before the infusion, caused significant and similar increases in blood levels, half-lives, and volumes of distribution of the 2 antibiotics. Protein binding in 100 percent human serum was 50 percent and 65 percent for carbenicillin and ticarcillin, respectively. These relatively small but definite differences in the pharmacokinetics of ticarcillin and carbenicillin are not likely to be of clinical significance.

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.

Clinical pharmacology and efficacy of ticarcillin in infants and children.

Ticarcillin was evaluated in 82 neonates and young infants with suspected sepsis and in 16 older children with chronic Pseudomonas infection of the mastoids. The infants also received kanamycin. Individual ticarcillin doses of 75 or 100 mg/kg were given every four, six, or eight hours by intramuscular injection or by a 30-minute intravenous infusion. Mean plasma concentrations one hour after a dose were from 125 to 189 microgram/ml, depending on dosage, age, and maturity. Mean plasma half-lives were approximately 5 hours in the first week of life, 2 hours in infants from 1 to 8 weeks, and 0.9 hours in older children. Volume of distribution was approximately twice as great in infants as in children, and plasma clearance rates correlated inversely with age. Limited efficacy data suggest that ticarcillin is a suitable alternative to ampicillin or carbenicillin, when given concurrently with an aminoglycoside, for newborn infections. When given for several days before mastoidectomy and tympanoplasty, ticarcillin sterilized the mastoids in the majority of patients. A new dosage schedule for ticarcillin in pediatric patients is proposed.

Ticarcillin: a review of its pharmacological properties and therapeutic efficacy.

Ticarcillin is a semisynthetic penicillin for parenteral administration. The antibacterial activity of ticarcillin is similar to that of carbenicillin except that it is two to four times more active in vitro against Pseudomonas aeruginosa, generally less active against Gram-positive cocci and more active against most Gram-negative bacilli. As the pharmacokinetics of ticarcillin and carbenicillin are also similar, ticarcillin should theoretically be clinically effective when administered at a lower dosage than carbenicillin. There is some evidence that ticarcillin is comparable in efficacy with carbenicillin when given in half to two-thirds the dosage, when the drugs are given in combination with an aminoglycoside and in clinical situations where these drugs are agents of choice. Ticarcillin has been used successfully in the treatment of complicated urinary tract infection, pulmonary infection in cystic fibrosis and bacteraemia and is effective when combined with an aminoglycoside in severe infections in patients with granulocytopenia. The efficacy in anaerobic infections is at present poorly documented, although preliminary results are promising. Tolerability has generally been good with hypokalaemia being the most frequently reported side effect. At the dosages used, bleeding and fluid overload have seldom occurred.

Val-237 for Ala substitution in the TEM-2 beta-lactamase dramatically alters the catalytic efficiencies towards carbenicillin and ticarcillin.

The mutant 554 of TEM-2 beta-lactamase was selected for a decrease in the resistance to carbenicillin of an Escherichia coli K12 carrier. The amino acid sequence of the mutant beta-lactamase was determined by manual Edman degradation analysis of proteolytic peptides. A single substitution Val for Ala was localized at position 237. The mutant exhibited only 2% of the catalytic efficiency of the wild-type enzyme towards carbenicillin and ticarcillin, whereas it retained 30-60% of the hydrolytic activity towards other penicillin and cephalosporin substrates. Carfecillin, the phenyl ester of the side-chain carboxyl group of carbenicillin, was hydrolysed as a good substrate. This suggests that the behaviour of the mutant enzyme towards carbenicillin may result from ionic rather than steric constraints. A molecular model of the Val-237 TEM-2 mutant suggests possible electrostatic interaction between Glu-171 and the carboxylic group of the side chain of carbenicillin.

Simultaneous determination of ticarcillin and clavulanate in rabbit serum and tissue cage fluid by liquid chromatography.

A gradient elution HPLC method with a wavelength switch technique was developed to simultaneously analyze the beta-lactam ticarcillin and the beta-lactamase inhibitor clavulanate in rabbit serum and tissue cage fluid (TCF). A C18 reversed-phase column with a programmable UV detector changing the wavelength from 218 to 254 nm at 9 min was used for chromatographic separation. The mobile phase consisted of acetonitrile, phosphate buffer and tetrabutylammonium hydrogen sulfate by following a gradient elution program at a flow-rate of 1 ml/min. Sample processing was carried out with liquid-liquid extraction. Good linearity, recoveries, precision and accuracy were obtained. The ranges of the standard curves were 1-100 microg/ml for ticarcillin, and 0.2-20 microg/ml for clavulanate. This assay has been successfully applied to analyze ticarcillin and clavulanate in rabbit serum and tissue cage fluid samples from a pharmacokinetic study.

Ticarcillin: pharmacokinetics in man according to different administration schedules.

The pharmacokinetic characteristics of ticarcillin, a semisynthetic penicillin more active than carbenicillin against Pseudomonas, were studied. Following a rapid intravenous infusion of 1 g, 2 g, 5 g and 10 g ticarcillin respectively the serum half-life was 72-4 minutes independent of the dosage administered. If ticarcillin is administered under steady-state conditions, e.g. continuous infusion of either 2g/hr or 1g/hr following a loading dose of 1g (total dose 5 g) the average steady-state serum concentrations are 125 microgram/ml and 105 microgram/ml respectively.

Pharmacokinetics of ticarcillin in the horse after intravenous and intramuscular administration.

Serum and peritoneal fluid concentrations of ticarcillin were measured in 10 healthy adult horses from 0.5 to 8 hours after IV or IM administration of 44 mg/kg of body weight. After IV injection, the serum concentration at 30 minutes was 104.3 +/- 6.1 mg/L and the mean peak peritoneal fluid concentration (61.4 +/- 29.0 mg/L) occurred 2 hours after injection. The peak serum (28.3 +/- 5.5 mg/L) and the peak peritoneal fluid concentrations (19.2 +/- 6.0 mg/L) occurred 2 hours after the IM injection. Ticarcillin (greater than or equal to 2 mg/L) persisted in serum and peritoneal fluid for 6 hours after IV injection and 8 hours after IM injection. The half-life of ticarcillin was 0.94 hour after IV injection and the bioavailability of ticarcillin administered IM was 64.9%.

Pharmacokinetics of ticarcillin in the dog.

Five healthy adult dogs were given a single IV dose (40 mg/kg of body weight) of ticarcillin disodium. Serum concentrations were measured serially over a period of 12 hours. Five days later, the drug was administered IM to the dogs at the same dose rate, and serum concentrations were measured serially for 12 hours. The mean peak serum concentration after IM administration was 120.5 micrograms/ml at 1.5 hours. Pharmacokinetic values following IV administration were (i) elimination rate constant = 0.8/hour-1, (ii) half-life = 0.8 hour, (iii) serum clearance = 292 ml/hr/kg, and (iv) apparent volume of distribution = 347 ml/kg. Estimated values after IM administration were (i) elimination rate constant = 0.6/hour, (ii) half-life = 1.1 hours, (iii) serum clearance = 218 ml/hr/kg, and (iv) apparent volume of distribution = 345 ml/kg; only the elimination rate constants were significantly different between the 2 routes of administration.

Pharmacokinetics and endometrial tissue concentrations of ticarcillin given to the horse by intravenous and intrauterine routes.

Plasma and endometrial tissue concentrations of ticarcillin were measured in healthy mares. In the first of the 3 separate phases comprising the study, ticarcillin disodium (30 mg/kg) was administered IV. The mean peak concentration in endometrial tissue, 12.9 micrograms/g, was attained at 30 minutes. The plasma half-life of the drug in the 6 mares was 0.83 +/- 0.22 hour. Six grams of the drug was diluted in 250 ml of sodium chloride injection USP (2nd phase) and in 60 ml of sodium chloride injection USP (3rd phase). These dilutions were administered by intrauterine infusion. In phase 2, the mean peak concentrations of the drug in plasma and endometrium were 2.76 micrograms/ml and greater than 150 micrograms/g, respectively, at 60 minutes after it was administered. Endometrial concentrations greater than 150 micrograms of ticarcillin/g persisted through 2 hours after the drug was administered. Mean peak plasma and endometrial concentrations of the drug in phase 3 were 2.78 micrograms/ml and greater than 150 micrograms/g at 45 and 30 minutes after administration was done, respectively. At 1 hour after the drug was administered, endometrial concentrations of ticarcillin were significantly higher (P less than 0.01) after the drug was infused intrauterinely in the 250-ml volume than those after the 60-ml volume was infused. It was concluded that the volume of fluid in which the drug was infused into the uterus markedly influenced the duration of concentrations greater than 20 micrograms/g in endometrial tissue.

[Chemotherapy of biliary tract infections. XIV. Biliary excretion and gallbladder tissue levels of piperacillin (author's transl)].

Piperacillin, a new injectable synthetic penicillin, was evaluated against biliary tract infections. 1. Two grams of piperacillin was intravenously administered to patients received cholecystectomy. The mean level in gallbladder bile of PIPC was 795.6 microgram/ml except for 3 cases in obstruction of the cystic duct. The mean gallbladder tissue level was 31.2 microgram/g. The gallbladder tissue level in the cases with obstruction of the cystic duct was high levels as 71.3 microgram/g and 79.5 microgram/g. 2. The excretion of PIPC into bile was compared with TIPC and APPC using crossover method. When administered 2 g of PIPC, the peak biliary levels were 950 microgram/ml to 2,120 microgram/ml at 2 hours and 20 minutes to 2 hours and 40 minutes after the administration, and biliary recoveries during 6 hours were 2.84% to 11.6%. The peak levels and biliary recoveries were lower after administration of TIPC 2 g. Mn and Zn were excreted enormously together with APPC into human bile. 3. The influence on clinical laboratory findings was negligible. Therefore, PIPC may be expected to show excellent effects of biliary tract infections except rare occurrence of drug eruption.

Comparative pharmacokinetics of low- and high-dose ticarcillin.

Certain antipseudomonal penicillins, such as mezlocillin, exhibit a nonlinear pharmacokinetic disposition with increasing doses. We evaluated the effect of a single low dose (50 mg/kg) compared with a high dose (80 mg/kg) on the pharmacokinetics of ticarcillin in a crossover trial of eight healthy volunteers. No significant alteration in plasma clearance (130.1 +/- 36.5 versus 120.5 +/- 38.0 ml/min), nonrenal clearance (36.5 +/- 8.4 versus 33.4 +/- 18.5 ml/min), or volume of distribution at steady state (12.8 +/- 3.5 versus 12.3 +/- 4.5 liters) was observed between the low- and high-dose regimens, respectively. The elimination half-life remained unchanged between the two doses (67.9 +/- 14.3 versus 68.0 +/- 12.2 min). Unlike other newer antipseudomonal penicillins, ticarcillin did not display dose-dependent pharmacokinetic behavior with the range of doses used in the clinical setting.