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Nosocomial Infections Caused by Acinetobacter spp. — Therapeutic Problems
Published in E. Bergogne-Bénézin, M.L. Joly-Guillou, K.J. Towner, Acinetobacter, 2020
Siegman-Igra et al. (1993) reviewed 25 cases of nosocomial Acinetobacter meningitis secondary to invasive procedures. For seven patients, the empirical therapy (ureidopenicillin plus an aminoglycoside) matched in vitro susceptibilities. For 16 patients, it was necessary to alter the regimen following in vitro susceptibility tests, in some cases to include the use of local amikacin injections. Unfortunately, details of the different regimens used were not reported by the authors. Two patients received inappropriate antibiotics and two patients died before receiving therapy. Eighteen of the 21 patients who were treated appropriately recovered from infection. Schonwald et al. (1989) used ciprofloxacin (200 mg every 12 h) to treat 20 patients with meningitis caused by Gram-negative bacilli, including three cases caused by Acinetobacter. All patients, including the latter, were cured. Acinetobacter could not be recovered from the CSF after therapy for 24 h, but CSF levels of ciprofloxacin were not reported. Segev et al. (1990) used i.v. pefloxacin at a dosage of 800 mg twice a day to treat four patients with Acinetobacter meningitis. Eradication was obtained in all four patients, with a mean CSF pefloxacin concentration of 8.8 mg/L.
An Outbreak of Pseudomonas Aeruginosa in a Neonatal Intensive Care Unit
Published in Meera Chand, John Holton, Case Studies in Infection Control, 2018
Trupti A. Patel, Michael Kelsey
Individual cases should be managed with appropriate antimicrobials such as third- and fourth-generation cephalosporins, ureidopenicillin, carbapenems, fluoroquinolones, or aminoglycosides after discussion with the microbiologists. If the isolate is multidrug-resistant or part of a suspected outbreak strain, then cases will need to be isolated in side rooms or in cohorts. In a neonatal unit, it is often sufficient to isolate infected patients within a designated area of the ward because nursing is provided on a one-to-one basis and infants are contained within incubators. Staff should be reminded, however, of the importance of hand hygiene to prevent further transmission. Generally, with a limited number of single-rooms, these should be reserved for patients who have conditions that facilitate transmission of infectious material to others (for example, draining wounds, stool incontinence not contained within diapers, and uncontained secretions) or for those who are at increased risk of acquisition and adverse outcomes (for example, immunosuppression).
Penicillins
Published in Thomas T. Yoshikawa, Shobita Rajagopalan, Antibiotic Therapy for Geriatric Patients, 2005
Mezlocillin, azlocillin, and piperacillin belong to the ureidopenicillin group of antipseudomonal penicllins. Their antipseudomonal activity is superior to that of carboxypenicillins. The most important drug of this group is piperacillin. It is commonly used in combination with the P-lactamase inhibitor tazobactam (see also the chapter “P Lactam/p-lactamase Inhibitors”). Ureidopenicillins are dispensed as monosodium salts with lower sodium concentrations than carboxypenicillins; however, caution still needs to be exercised when treating elderly patients with cardiac or renal disease. These agents are minimally metabolized (< 10%) and mainly eliminated in active form by glomerular filtration and tubular secretion. They have considerable biliary excretion, which results in high levels in the biliary system. An important pharmacokinetic consideration is that increasing doses of these antibiotics result in nonlinear increased antibiotic levels and decreased clearance. Due to their structure, penetration of bacterial cell wall is enhanced and their affinity for PBP is also increased. An additional feature possessed by ueidopenicillins is inhibitory activity on the septum of the dividing bacteria (10).
Antibiotic susceptibility variations of Methicillin-resistant Staphylococcus aureus after gamma irradiation
Published in International Journal of Radiation Biology, 2020
Soroush Oskouee, Seyed Amir Hossein Feghhi, Neda Soleimani
It is appropriate to review antibiotics’ mechanism of actions (those that are used in this research) before proceeding further. Oxacillin is known to be from Beta-lactam antibiotics group, PBPs (penicillin binding proteins) are the primary targets of the β-lactam agents. It has been hypothesized that the β-lactam ring mimics the D-alanyl D-alanine portion of peptide chain that is normally bound by PBP. The PBPs interact with β-lactam ring and consequently are not available for the synthesis of new peptidoglycan (Džidic et al. 2008). Piperacillin is also a broad-spectrum β-lactam antibiotic of the ureidopenicillin class (Tan and File 1995). Azithromycin prevents bacteria from growing by interfering with their protein synthesis. It binds to the 50S subunit of the bacterial ribosome, hence inhibiting translation of mRNA while nucleic acid synthesis is not affected (Parnham et al. 2014). Polymyxin B Alters bacterial outer membrane permeability by binding to a negatively charged site in the lipopolysaccharide layer, which has an electrostatic attraction for the positively charged amino groups in the cyclic peptide portion (Schindler and Teuber 1975). Trimethoprim and Sulfamethoxazole inhibit successive steps in the folate synthesis pathway (Wormser et al. 1982). Rifampin specifically inhibits bacterial RNA polymerase, the enzyme responsible for DNA transcription, by forming a stable drug-enzyme complex (Wehrli 1983).
Synthesis and evaluation of polymeric micelle containing piperacillin/tazobactam for enhanced antibacterial activity
Published in Drug Delivery, 2019
Milani Morteza, Salehi Roya, Hamishehkar Hamed, Zarebkohan Amir, Akbarzadeh Abolfazl
Antibiotic treatment of this pathogen is extremely difficult due to multiple resistance mechanisms, such as b-lactamases, efflux pumps, and the impermeability of the outer membrane (Bassetti et al., 2018). In fact, this leads to a serious limitation of the options for the treatment of P. aeruginosa infections. Nowadays several antibiotics are used to treat P. aeruginosa infections. Piperacillin is a potent, broad-spectrum ureidopenicillin that is used against gram-negative, gram-positive and anaerobic bacteria. When combined with beta-lactamase inhibitors such as tazobactam, it demonstrates a broader spectrum of activity against lactamase-producing bacteria. For its spectrum of activity, Piperacillin/tazobactam is a β-lactam/β-lactamase inhibitor combination widely employed in first-line therapy, particularly for nosocomial infections (Grant et al., 2002; Fonseca et al., 2004; Lodise et al., 2007). Based on some studies, treatment with subinhibitory concentrations of antibiotics may be effective on bacterial virulence factors, such as adherence, motility and biofilm formation (Wolter & McCormack, 1998; Wilson et al., 2002; Fonseca et al., 2004). The emergence of multidrug-resistant pathogens including cephalosporins and fluoroquinolones has led to the use of Piperacillin/Tazobactam. On the other hand, Piperacillin/Tazobactam is considered a safe antimicrobial agent and has fewer side effects than penicillin derivatives.
Current and emerging pharmacotherapy for the treatment of bacterial peritonitis
Published in Expert Opinion on Pharmacotherapy, 2018
Alberto Enrico Maraolo, Ivan Gentile, Biagio Pinchera, Salvatore Nappa, Guglielmo Borgia
Piperacillin/tazobactam is a combination of beta-lactam/beta-lactamase inhibitor (BLBLI), putting together a semi-synthetic ureidopenicillin (piperacillin) with an extended spectrum of activity and an irreversible inhibitor of bacterial beta-lactamases (tazobactam) [67]. The main advantage over 3GCs, in addition to an antipseudomonal activity that is not shared by ceftriaxone or cefotaxime and its activity against many enterococci, is the activity against beta-lactamases-producers GNB in absence of other mechanisms of resistance [68]. Notwithstanding, there is some debate regarding the efficacy against ESBL producers [68].