Cefepime microbiologic profile and update

A review on current advancement in zebrafish models to study chronic inflammatory diseases and their therapeutic targets

Chronic inflammatory diseases are caused due to prolonged inflammation at a specific site of the body. Among other inflammatory diseases, bacterial meningitis, chronic obstructive pulmonary disease (COPD), atherosclerosis and inflammatory bowel diseases (IBD) are primarily focused on because of their adverse effects and fatality rates around the globe in recent times. In order to come up with novel strategies to eradicate these diseases, a clear understanding of the mechanisms of the diseases is needed. Similarly, detailed insight into the mechanisms of commercially available drugs and potent lead compounds from natural sources are also important to establish efficient therapeutic effects. Zebrafish is widely accepted as a model to study drug toxicity and the pharmacokinetic effects of the drug. Moreover, researchers use various inducers to trigger inflammatory cascades and stimulate physiological changes in zebrafish. The effect of these inducers contrasts with the type of zebrafish used in the investigation. Hence, a thorough analysis is required to study the current advancements in the zebrafish model for chronic inflammatory disease suppression. This review presents the most common inflammatory diseases, commercially available drugs, novel therapeutics, and their mechanisms of action for disease suppression. The review also provides a detailed description of various zebrafish models for these diseases. Finally, the future prospects and challenges for the same are described, which can help the researchers understand the potency of the zebrafish model and its further exploration for disease attenuation.

Review on Characterization, Properties, and Analytical Methods of Cefepime

Infection is one of the most important reasons for the increase in the number of deaths worldwide; it can be a bacterial or viral infection. As a result, there are many effective drugs against this infection, especially bacterial ones. Cefepime (CP) is one of the fourth generations of cephalosporins and is distinguished from others in that it can kill both positive and negative bacteria. Therefore, this study focused on the chemical properties of the drug, its uses, and its stability against bacteria. All analysis methods for this drug in pharmaceutical preparations, blood, or plasma were also presented. One of the important problems in these methods is using toxic solvents, which poses a danger to society and the environment. The presentation of these solvents will allow companies to manufacture and use more effective and less toxic solvents.

Cefepime use: A need for antimicrobial stewardship

OBJECTIVES

Unlike other 3GCs, Cefepime is a cephalosporin that has, in animal model studies, shown a low risk of selecting resistant mutants. It also enables carbapenems to be saved in treatment of Pseudomonasaeruginosa and the CESP group (Citrobacter, Enterobacter, Serratia and Providencia, as well as the genus Klebsiellaaerogenes, Morganella and Hafnia), consequently producing cephalosporinase. We aimed to determine whether its prescription in a French teaching hospital met criteria for proper use.

PATIENTS AND METHODS

We conducted a retrospective study of proper cefepime use between March 1st, 2018 and February 28th, 2019, to assess indication, antimicrobial stewardship, dosing schedule, microbiological documentation, reevaluation, and treatment duration. Prescriptions were then compared to local guidelines established from international literature.

RESULTS

Out of 142 cefepime prescriptions, 97.2% were prescribed as validated according to indication. The duration of the documented treatments matched the guidelines for 56.5% of patients, dosage was adapted to the indication for 77.4% and to kidney function for 97.2%. Bacteriological documentation was performed in all cases and an antibiogram was generated in 99.2% of cases. The treatment was reassessed between 48 and 72h and between the 7th and 10th day for 44.2% and 60.9% of the prescriptions respectively. The antimicrobial stewardship team managed half of the prescriptions. Only 13.4% of prescriptions met all criteria for proper use.

CONCLUSION

Notwithstanding a highly sizable majority of validated indications, a very small proportion of cefepime prescriptions met all the criteria for proper use. In the context of increased cefepime consumption, which is favored by its increased place in the latest recommendations published in 2019, proper use of cefepime prescriptions needs to be more effectively promoted.

Molecular Interactions of Cephalosporins with the Deep Binding Pocket of the RND Transporter AcrB

The drug/proton antiporter AcrB, part of the major efflux pump AcrABZ-TolC in Escherichia coli, is characterized by its impressive ability to transport chemically diverse compounds, conferring a multidrug resistance phenotype. However, the molecular features differentiating between good and poor substrates of the pump have yet to be identified. In this work, we combined molecular docking with molecular dynamics simulations to study the interactions between AcrB and two representative cephalosporins, cefepime and ceftazidime (a good and poor substrate of AcrB, respectively). Our analysis revealed different binding preferences of the two compounds toward the subsites of the large deep binding pocket of AcrB. Cefepime, although less hydrophobic than ceftazidime, showed a higher affinity than ceftazidime for the so-called hydrophobic trap, a region known for binding inhibitors and substrates. This supports the hypothesis that surface complementarity between the molecule and AcrB, more than the intrinsic hydrophobicity of the antibiotic, is a feature required for the interaction within this region. Oppositely, the preference of ceftazidime for binding outside the hydrophobic trap might not be optimal for triggering allosteric conformational changes needed to the transporter to accomplish its function. Altogether, our findings could provide valuable information for the design of new antibiotics less susceptible to the efflux mechanism.

Gram-Negative Bacterial Resistance to Cephalosporins in Community-Acquired Infections in Turkey

Cephalosporins are widely used and trustworthy antibiotics in daily medical practice. Although antibacterial resistance has been reported in hospital wards, there are less data for community-acquired infections. In this study we investigated the cephalosporin susceptibility profiles of community-acquired Gram-negative bacteria isolates in Sivas Kizilay Medical Center (Turkey) between March 2002 and March 2003. In our study, 949 Escherichia coli, 165 Proteus spp., 97 Enterobacter spp., 24 Klebsiella spp and 84 Pseudomonas aeruginosa strains were evaluated. Cefepime seemed to be the most effective antibiotic against our community-acquired Gram-negative isolates. Resistance to this drug was 19.3% for P. aeruginosa and around 0-10.6% for enteric bacteria. Enteric pathogen resistance ranged between 44.3-100% for cefazolin, 25-51.9% for cefuroxime, 4.8-25.3% for ceftriaxone, 5.4-14.5% for ceftazidime. Resistance in enteric pathogens to gentamicin ranged between 5.8-15.4%, to amikacin between 3.8-6.25%, to ciprofloxacin between 6.7-20%. 8.1% of P. aeruginosa were resistant to ciprofloxacin. With these profiles the aminoglycosides and ciprofloxacin resemble highly effective cephalosporins like cefepime. On the contrary, first- and second-generation cephalosporins, trimethoprim-sulfamethoxazole, ampicillin and ampicillin-sulbactam are no longer used in probable Gram-negative bacterial infections in our region. Since treatment based on cephalosporins was less efficacious than expected in community-acquired infections, urgent measures are needed to limit antibacterial resistance outside of hospitals.

Cefepime

Cefepime (Maxipime), Maxcef, Cepimax, Cepimex, Axepim, a parenteral fourth-generation cephalosporin, is active against many organisms causative in pneumonia. Cefepime has in vitro activity against Gram-positive organisms including Staphylococcus aureus and penicillin-sensitive, -intermediate and -resistant Streptococcus pneumoniae similar to that of cefotaxime and ceftriaxone. Cefepime also has good activity against Gram-negative organisms, including Pseudomonas aeruginosa, similar to that of ceftazidime. Importantly, cefepime is stable against many of the common plasmid- and chromosome-mediated beta-lactamases and is a poor inducer of AmpC beta-lactamases. As a result, it retains activity against Enterobacteriaceae that are resistant to third-generation cephalosporins, such as derepressed mutants of Enterobacter spp. Cefepime may be hydrolyzed by the extended-spectrum beta-lactamases produced by some members of the Enterobacteriaceae, but to a lesser extent than the third-generation cephalosporins. Monotherapy with cefepime 1 or 2g, usually administered intravenously twice daily, was as effective for clinical and bacteriological response as ceftazidime, ceftriaxone or cefotaxime monotherapy (1 or 2g two or three times daily) in a number of randomized, clinical trials in hospitalized adult, or less commonly, pediatric, patients with generally moderate to severe community-acquired or nosocomial pneumonia. More limited data indicated that monotherapy with cefepime 2g three times daily was also as effective in treating patients with nosocomial pneumonia as imipenem/cilostatin 0.5g four times daily, and when combined with amikacin, cefepime was as effective as ceftazidime plus amikacin. Patients with pneumonia who failed to respond to previous antibacterial therapy with penicillins or other cephalosporins responded to treatment with cefepime. Cefepime is generally well tolerated, with a tolerability profile similar to those of other parenteral cephalosporins. In clinical trials, the majority of adverse events experienced by cefepime recipients were mild to moderate and reversible. The most common adverse events with a causal relationship to cefepime reported in clinical trials included rash and diarrhea. Other, less common, adverse events included pruritus, urticaria, nausea, vomiting oral candidiasis, colitis, headache, fever, erythema and vaginitis.

CONCLUSION

Cefepime is an established and generally well tolerated parenteral drug with a broad spectrum of antibacterial activity which, when administered twice daily, provides coverage of most of the pathogens that may be causative in pneumonia. In randomized clinical trials in hospitalized patients with generally moderate to severe community-acquired or nosocomial pneumonia, cefepime monotherapy exhibited good clinical and bacteriological efficacy. Cefepime may become a preferred antibacterial agent for infections caused by Enterobacter spp. With prudent use in order to prevent the emergence of resistant organisms, cefepime will continue to be a suitable option for the empiric treatment of pneumonia.

Pathogens resistant to antibacterial agents

Resistance to antimicrobial drugs is increasing at an alarming rate among both gram-positive and gram-negative bacteria. Traditionally, bacteria resistant to multiple antimicrobial agents have been restricted to the nosocomial environment. A disturbing trend has been the recent emergence and spread of resistant pathogens in nursing homes, in the community, and in the hospital. This article reviews the epidemiology, molecular mechanisms of resistance, and treatment options for pathogens resistant to antimicrobial drugs.

Antibacterial agents in pediatrics

Antibiotics are among the most frequently used drugs in children. Although antibacterials have been available for decades, many agents have not been studied to assess their safety and efficacy in the pediatric population. This article describes the pharmacologic characteristics and therapeutic use of the most commonly prescribed antibacterials for pediatric patients. Newer agents currently under clinical investigation are discussed as well.

Comparisons of parenteral broad-spectrum cephalosporins tested against bacterial isolates from pediatric patients: report from the SENTRY Antimicrobial Surveillance Program (1998–2004)

A contemporary collection of 12737 strains from pediatric patients (<18 years) isolated over a 7-year period (1998-2004) from 52 sentinel hospitals in North America was tested to determine the comparative antimicrobial potency of broad-spectrum parenteral cephalosporins and selected comparator agents. Most of the strains (84.1%) were isolated from blood stream or respiratory tract infections. The rank order of the top 10 pediatric pathogens analyzed was Streptococcus pneumoniae (15.5%) >Haemophilus influenzae (14.6%) >Staphylococcus aureus (13.8%) >Moraxella catarrhalis = coagulase-negative staphylococci (8.0%) >Escherichia coli (7.8%) >Pseudomonas aeruginosa (5.2%) >Klebsiella spp. (4.8%) >Enterococcus spp. (4.7%) > beta-hemolytic streptococci (4.4%). Both cefepime and ceftriaxone (MIC(90), 1 microg/mL; 93.9% and 93.7% susceptible, respectively) were highly active against S. pneumoniae. However, the S. pneumoniae strains showed reduced susceptibility to ceftazidime (56.6%), as well as penicillin (56.6%) < trimethoprim-sulfamethoxazole (57.1%) < erythromycin (66.2%) < tetracycline (71.4%). beta-Hemolytic streptococci showed 100.0% susceptibility to penicillin, cefepime, and ceftriaxone. Cefepime and ceftriaxone exhibited high activity against oxacillin (methicillin)-susceptible S. aureus, (MIC(90), 4 microg/mL; 100.0% and 99.8% susceptible, respectively), whereas ceftazidime (MIC(90), 16 microg/mL) was active against only 86.7% of strains. H. influenzae strains showed complete susceptibility to cefepime, ceftriaxone, and levofloxacin (MIC(90), < or =0.5 microg/mL; 100.0%), and 34.0% of H. influenzae and 99.2% of M. catarrhalis strains produced beta-lactamase. Although the 3 cephalosporins tested (cefepime, ceftriaxone, and ceftazidime) were very active (98.6-99.6% susceptible) against E. coli, cefepime (99.0% susceptible) was slightly more active than ceftriaxone and ceftazidime (96.4% and 95.1% susceptible, respectively) against Klebsiella spp. Cefepime was also the most active beta-lactam agent tested against Enterobacter spp. (MIC(90), 2 microg/mL; 99.3% susceptible), whereas the susceptibility rates of other broad-spectrum beta-lactams (ceftriaxone, ceftazidime and piperacillin-tazobactam) were significantly lower (78.4-81.5%). Against P. aeruginosa, imipenem and piperacillin-tazobactam showed the highest susceptibility rates (94.4% and 93.3%, respectively), whereas imipenem and cefepime showed the lowest resistance rates (1.4% and 2.3%, respectively). Our results indicate that cefepime was the most broad-spectrum cephalosporin analyzed and remains a very potent alternative for the treatment of contemporary pediatric infections in North America.

Cefepime versus ceftazidime: considerations for empirical use in critically ill patients

Sepsis and nosocomial infections continue to be a significant problem in intensive care, contributing heavily to mortality and prolonged hospital stay. Early and appropriate antibiotic therapy is critical for optimising outcomes. However, the emergence of highly resistant bacteria, coupled with reduced development of novel antibiotics, means that there is a real threat of development of untreatable nosocomial infections. Cefepime and ceftazidime are broad-spectrum cephalosporins that are widely used to treat Gram-negative nosocomial infections in critically ill patients. Available data suggest that cefepime may have advantages over ceftazidime owing to a broader spectrum of activity and reduced potential for development of bacterial resistance. However, whether either of these agents is superior can only be determined by a head-to-head study evaluating clinical and bacteriological outcomes. Such a study to determine whether apparent differences translate into clinically relevant differences in outcome is indicated.

Potency and spectrum trends for cefepime tested against 65746 clinical bacterial isolates collected in North American medical centers: results from the SENTRY Antimicrobial Surveillance Program (1998-2003)

We evaluated the antimicrobial spectrum and potency of cefepime and selected comparators agents against clinical bacterial strains collected in North America over a 6-year period (1998-2003). Isolates were consecutively collected from bloodstream (44%), respiratory tract (41%), urinary tract (6%), and skin/soft tissue (5%) infections in 48 medical centers. Isolates were susceptibility tested by reference broth microdilution methods in a central laboratory. Oxacillin-resistant staphylococci and enterococci were excluded from the analysis. Imipenem (MIC90 = 1 microg/mL, 99.9% susceptible) was the most active compound tested against Enterobacteriaceae (22860 isolates tested) followed by cefepime (MIC90 = 0.25 microg/mL, 99.5% susceptible) > amikacin (99.4% susceptible) > ceftriaxone (95.6% susceptible) > aztreonam (95.1% susceptible). Among comparators, the lowest susceptibility rate for Enterobacteriaceae was observed with ciprofloxacin (92.8% susceptible). Imipenem was also the most active compound against ESBL-producing Klebsiella spp. and Escherichia coli (99.3% and 100% susceptible, respectively), followed by amikacin (81.4% and 97.2% susceptible, respectively) and cefepime (92.5% and 93.8% susceptible, respectively). Cefepime activity against Pseudomonas aeruginosa (85.2% susceptible) was similar to that of imipenem (86.9% susceptible). Against oxacillin-susceptible Staphylococcus aureus, cefepime (MIC90 = 4 microg/mL, 100.0% susceptible) was 4-fold more active than ceftazidime (MIC90 = 16 microg/mL, 86.4% susceptible) and showed a higher susceptibility rate than ciprofloxacin (93.2% susceptible). Cefepime was the most active compound tested against Streptococcus pneumoniae (MIC90 = 1 microg/mL, 97.4% susceptible), ranked after gatifloxacin and levofloxacin (99.2% susceptible). The activity of cefepime remained stable during the study period evaluated with the susceptibility rates varying from 99.3% to 99.8% among the Enterobacteriaceae and 84.4% to 88.4% among P. aeruginosa isolates. In summary, cefepime has retained broad activity and spectrum against Enterobacteriaceae, P. aeruginosa, and Gram-positive cocci (except oxacillin-resistant staphylococci and enterococci) isolated from North American medical centers in the 1998-2003 period. Continued resistance surveillance is critical to monitor the effectiveness of widely used parenteral antimicrobial agents such as cefepime.

Fourth-Generation Cephalosporins: In vitro Activity against Nosocomial Gram-Negative Bacilli Compared with β-Lactam Antibiotics and Ciprofloxacin

The in vitro activity of two new expanded spectrum fourth-generation cephalosporins, cefepime and cefpirome, was compared with that of five antibacterial agents, ceftazidime, cefoperazone, cefotaxime, imipenem, and ciprofloxacin, that are commonly used in the treatment of serious infections caused by aerobic gram-negative bacteria. The agar dilution method described by the US National Committee for Clinical Laboratory Standards was used to determine the minimum inhibitory concentrations of antibiotics tested. Three hundred and two clinical isolates, representing a cross-section of Klebsiella and Enterobacter species and Pseudomonas aeruginosa were tested. The most potent beta-lactams were imipenem, cefepime, and cefpirome, which demonstrated significant activity against the majority of strains in all three genera of bacteria, as did ciprofloxacin. Ceftazidime was active against P. aeruginosa, but was less potent against Klebsiella and Enterobacter species. Cefoperazone and cefotaxime were less active than ceftazidime against P. aeruginosa. Cefepime had slightly greater activity than cefpirome against the gram-negative bacteria tested. These data indicate that cefepime and cefpirome are highly active against many frequently resistant nosocomial bacterial strains that are traditionally responsible for difficult-to-treat infections.

Pharmacodynamics of cefepime alone and in combination with various antimicrobials against methicillin-resistant Staphylococcus aureus in an in vitro pharmacodynamic infection model

Treatment options for gram-positive resistant bacteria are limited; therefore, efforts to evaluate therapy options in the critical care population are warranted. Cefepime has broad-spectrum activity against gram-negative and gram-positive organisms. We have previously demonstrated that the combination of cefepime with vancomycin, linezolid, or quinupristin-dalfopristin had an improved or enhanced effect against methicillin-resistant Staphylococcus aureus (MRSA). We investigated various regimens of cefepime alone and in combination against two clinical MRSA isolates (R2481 and R2484) in an established in vitro pharmacodynamic model. Human pharmacokinetic regimen simulations were as follows: cefepime, 2 g every 8 h (q8h) (C8) and 12 h (C12), continuous-infusion 2-g loading dose followed by 4 g alone or in combination with gentamicin and tobramycin (1.0 or 2.0 [G1 and G2 or TB1 and TB2] mg/kg of body weight q12h and 5.0 [G5 or TB5] mg/kg q24h), arbekacin (ARB) (100 mg q12h), linezolid (LIN) (600 mg q12h), tigecycline (TIG) (100 mg q24h), or daptomycin (DAP) (6 mg/kg q24h) for 48 h. The MICs for cefepime, gentamicin, tobramycin, ARB, LIN, TIG, and DAP for the two clinical MRSA isolates (R2481 and R2484) were 4 and 4, 0.25 and 0.5, 128 and 0.5, 0.5 and 0.125, 2 and 4, 0.25 and 0.25, and 0.0625 and 0.125 microg/ml, respectively. At 48 h, combinations of C12 and C8 plus ARB, G1, or G5 (range, -2.05- to -4.32-log(10) decrease) demonstrated enhanced lethality against R2481 (resistant to tobramycin) (P < 0.05). A similar relationship was demonstrated against R2484 with cefepime plus ARB, gentamicin, or tobramycin (range, -2.05- to -3.63-log(10) decrease) (P < 0.05). A 99.9% kill was achieved with cefepime plus aminoglycoside combinations as early as 2 h and maintained throughout the 48-h period. TIG was antagonistic when combined with C12 against both isolates. DAP alone achieved 99.9% kill for up to 48 h for both isolates and was the most active agent against R2481 and R2484 (-2.89- and -3.61-log(10) decrease at 48 h); therefore, combination therapy did not enhance lethality. Overall, the most potent combinations noted were cefepime in combination with low- and high-dose aminoglycosides. Further investigations with combination therapies are warranted.

Cefepime versus ceftazidime + amikacin as empirical therapy for febrile neutropenia in children with cancer: a prospective randomized trial of the treatment efficacy and cost

The efficacy, safety, and cost of cefepime and ceftazidime + amikacin as empirical therapy in children with febrile neutropenia is compared. A prospective randomized study in children with cancer was conducted. Patients were randomly assigned to receive either cefepime 150 mg/kg/day or ceftazidime 150 mg/kg/day combined with amikacin 15 mg/kg/day. Treatment modification was defined as all the changes in the empirical antimicrobials after the first 72 h. Overall treatment success was defined as cure of febrile episode with or without modification. Costs of hospitalization, antimicrobial drugs, and supportive therapy were calculated. Fifty febrile netropenic episodes were evaluated. Infectious agents were microbiologically identified in 28% of episodes. The incidence of gram-negative and gram-positive isolates was equal. Overall treatment success was 100% and success of initial empirical therapy without modification was 52 and 40% in the cefepime and cefepime + amikacin groups, respectively. The response rate after glycopeptides were added to the regimen was 64 and 52 % in the cefepime and cefepime + amikacin arms, respectively. Glycopeptide and antifungal drugs were added more frequently in the ceftazidime + amikacin group. Duration of fever, hospitalization, and antimicrobial drug administration were longer in the ceftazidime + amikacin arm. The costs of the antimicrobial drugs, hospitalization, and total cost were lower in the cefepime arm. Cefepime monotherapy is as effective as ceftazidime + amikacin combination in febrile neutropenia of pediatric cancer patients and must be preferred due to shorter defervescence of fever, shorter hospitalization, and lower therapy cost.

Acute Bacterial Meningitis in Children

Despite advances in recent decades in management, including new and effective antimicrobials, children with bacterial meningitis still incur significant morbidity and mortality. Pathophysiologic processes including colonization and migration of the bacteria to blood, seeding of the meninges, and meningeal and brain inflammation have been largely elucidated, but more specific knowledge could lead to new effective therapies. Outside of the neonatal period, the most common causative organisms have been Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis. However, conjugate vaccines, especially the H influenzae type b preparation, have contributed significantly to steep declines in the incidence of meningitis. Optimal management consists of rapid diagnosis and administration of bactericidal antibiotics with properties allowing adequate penetration of the inflamed blood-brain barrier. Recently, development of microbial resistance has resulted in changes to recommended empiric antibiotic regimens. Novel therapies are under investigation; however, until controlled trials can be conducted, these therapies cannot be recommended.

Empiric use of cefepime in the treatment of lower respiratory tract infections in children

BACKGROUND

These studies were designed to assess the efficacy and safety of cefepime, a fourth generation cephalosporin, for the treatment of serious infections, including lower respiratory tract infections (LRTI) in children.

METHODS

Four clinical trials of cefepime for the treatment of serious bacterial infections enrolled 259 children with LRTI. In 3 trials cefepime was compared with ceftazidime (n = 166), cefotaxime (n = 16) or cefuroxime (n = 12). One trial was noncomparative (n = 65).

RESULTS

Treatment with cefepime 50 mg/kg/ dose administered every 8 to 12 h produced a satisfactory clinical response (clinical signs of infection resolved or improved with no evidence of recurrent infection at posttreatment follow-up) in 88 to 100% of patients, comparable with comparator therapy. In children from whom a causative pathogen was identified, bacteriologic eradication was comparable between cefepime and comparator therapy. Cefepime was as safe and well-tolerated as comparator therapy. Few treatment-related clinical or laboratory adverse events were noted and were equivalent to comparator in all studies.

CONCLUSION

Cefepime is as effective, safe and well-tolerated for the empiric treatment of children with LRTI as comparator agents but offers the advantage of an enhanced spectrum of activity for Gram-positive and Gram-negative pathogens compared with second or third generation cephalosporins.