Compassionate use of a novel ß-lactam enhancer-based investigational antibiotic cefepime/zidebactam (WCK 5222) for the treatment of extensively-drug-resistant NDM-expressing Pseudomonas aeruginosa infection in an intra-abdominal infection-induced sepsis patient: a case report.

Infections in critically-ill patients caused by extensively-drug-resistant (XDR)-Pseudomonas aeruginosa are challenging to manage due to paucity of effective treatment options. Cefepime/zidebactam, which is currently in global Phase 3 clinical development (Clinical Trials Identifier: NCT04979806, registered on July 28, 2021) is a novel mechanism of action based ß-lactam/ ß-lactam-enhancer combination with a promising activity against a broad-range of Gram-negative pathogens including XDR P. aeruginosa. We present a case report of an intra-abdominal infection-induced sepsis patient infected with XDR P. aeruginosa and successfully treated with cefepime/zidebactam under compassionate use. The 50 year old female patient with past-history of bariatric surgery and recent elective abdominoplasty and liposuction developed secondary pneumonia and failed a prolonged course of polymyxins. The organism repeatedly isolated from the patient was a New-Delhi metallo ß-lactamase-producing XDR P. aeruginosa resistant to ceftazidime/avibactam, imipenem/relebactam and ceftolozane/tazobactam, susceptible only to cefepime/zidebactam. As polymyxins failed to rescue the patient, cefepime/zidebactam was administered under compassionate grounds leading to discharge of patient in stable condition. The present case highlights the prevailing precarious scenario of antimicrobial resistance and the need for novel antibiotics to tackle infections caused by XDR phenotype pathogens.

Cost-effectiveness of ceftazidime/avibactam plus metronidazole versus meropenem as first-line empiric therapy for the treatment of complicated intra-abdominal infections: A study based on the in-vitro surveillance data in China.

BACKGROUND: With the increase in drug resistance rates of pathogens isolated from complicated intra-abdominal infections (cIAIs), ceftazidime/avibactam (CAZ-AVI) is increasingly used clinically. However, given the high drug cost and the fact that not yet covered by the health insurance payment, this study evaluated the cost-effectiveness of CAZ-AVI plus metronidazole versus meropenem as a first-line empiric treatment for cIAIs from the perspective of the Chinese healthcare system. METHODS: A decision analytic model with a one-year time horizon was constructed to assess the cost-effectiveness based on the entire disease course. Model inputs were mainly obtained from clinical studies, published literature, and publicly available databases. Primary outcomes were cost, quality-adjusted life years (QALYs), life years (Lys), and incremental cost-effectiveness ratio (ICER). One-way sensitivity analysis and probabilistic sensitivity analysis were also performed. RESULTS: In the base cases, compared to meropenem, CAZ-AVI plus metronidazole had a shorter mean hospital length of stay (-0.77 days per patient) and longer life expectancy (+0.05 LYs and +0.06 QALYs). CAZ-AVI plus metronidazole had an ICER of $25517/QALY, which is well below the threshold of $31509 per QALY in China. The one-way sensitivity analysis showed that the change of the treatment duration of CAZ-AVI plus metronidazole was the parameter that most influenced the results of the ICER. In probabilistic sensitivity analysis, CAZ-AVI plus metronidazole was the optimal strategy in 75% of simulations at $31510/QALY threshold. CONCLUSIONS: CAZ-AVI plus metronidazole could be considered as a cost-effective option for the empiric treatment of patients with cIAIs in China, and this benefit will be more evident when the price of CAZ-AVI decreases by 23.8%.

Are there differences between ceftolozane/tazobactam and ceftazidime/avibactam in treating patients with complicated abdominal infections? Evidence from clinical trials.

Ceftolozane/tazobactam (C/T) and ceftazidime/avibactam (CZA) are new possibilities of antimicrobial treatment that combined a ß-lactam with a ß-lactamase inhibitor. The United States (US) and European regulatory agencies approved their clinical use in adults with complicated intra-abdominal infections. This study aims to know if one of the two antibiotics obtain better efficacy in adults with complicated intra-abdominal infections and by specific pathogens such as P. aeruginosa or E. coli. A search of all trials in MEDLINE, Scopus, and Web of Science comparing a C/T or CZA based antimicrobial regimen with other treatments in patients with intraabdominal infections until August 2021 was performed. To make indirect comparisons, we used a frequentist approach using the R package netmeta.The effects have been expressed through the relative risk (RR) with its confidence interval. Considering the clinical cure and failure rates between the different trial populations (mMITT, CE, ME) and the mortality at the end of the study, we have not found significant differences between CZA and C/T. In the case of Pseudomonas, the RR of treatment failure between these two antibiotics is 1 (95% CI 0.55-1.18). In the case of E. Coli, although it seems that CZA would have a worse result than C/T, differences did not reach statistical significance (RR1.06; 95% CI 0.9-1.14). In conclusion, we have not found statistically significant differences between ceftolozane-tazobactam and ceftazidime-avibactam in treating cIAI. In regards to E. Coli, our results do not reach significance, but it would be possible that C/T and meropenem had better results than CZA. Perhaps new trials would allow a better profile of the role in different types of patients or infections caused by specific microorganisms in the future.

First case of abdominal infection caused by bacteroides fluxus.

Bacteroides fluxus is a Gram-negative anaerobic bacillus isolated from human faeces in healthy individuals. Until now, this bacterium had not been involved in human diseases. We report the first case of abdominal infection due to this microorganism in an elderly patient. A 76-year-old man with a history of chronic pulmonary obstructive disease presented with dyspnea, orthopnea and cough. The clinical evolution worsened with both a colonic ischemia and further diffuse peritonitis of pancreatic origin. Peritoneal fluid was obtained and the culture yielded B. fluxus in pure culture. Resistance to penicillin, amoxicillin-clavulanate, clindamycin and moxifloxacin was documented. Treatment with meropenem + linezolid was started, but the patient finally died due to a multiorganic failure.

Considerations in the Selection of Renal Dosage Adjustments for Patients with Serious Infections and Lessons Learned from the Development of Ceftazidime-Avibactam.

An extensive clinical development program (comprising two phase 2 and five phase 3 trials) has demonstrated the efficacy and safety of ceftazidime-avibactam in the treatment of adults with complicated intra-abdominal infection (cIAI), complicated urinary tract infection (cUTI), and hospital-acquired pneumonia (HAP), including ventilator-associated pneumonia (VAP). During the phase 3 clinical program, updated population pharmacokinetic (PK) modeling and Monte Carlo simulations using clinical PK data supported modified ceftazidime-avibactam dosage adjustments for patients with moderate or severe renal impairment (comprising a 50% increase in total daily dose compared with the original dosage adjustments) to reduce the risk of subtherapeutic drug exposures in the event of rapidly improving renal function. The modified dosage adjustments were included in the ceftazidime-avibactam labeling information at the time of initial approval and were subsequently evaluated in the final phase 3 trial (in patients with HAP, including VAP), providing supportive data for the approved U.S. and European ceftazidime-avibactam dosage regimens across renal function categories. This review describes the analyses supporting the ceftazidime-avibactam dosage adjustments for renal impairment and discusses the wider implications and benefits of using modeling and simulation to support dosage regimen optimization based on emerging clinical evidence.

Eravacycline: a new treatment option for complicated intra-abdominal infections in the age of multidrug resistance.

Aim: Recently approved for use in complicated intra-abdominal infection, eravacycline is a novel fluorocycline with broad spectrum of activity against resistant Gram-negative pathogens. This manuscript is a pooled analysis of two Phase III trials. Clinical efficacy: Clinical cure rates were 86.8% for eravacycline versus 87.6% for ertapenem, and 90.8% for eravacycline versus 91.2% for meropenem in the Intent to Treat (micro-ITT) populations, and 87.0% for eravacycline versus 88.8% ertapenem, and 92.4 versus 91.6% for meropenem in the Modified Intent to Treat (MITT) populations. Safety: Eravacycline is well tolerated, with lower rates of nausea, vomiting and diarrhea than other tetracyclines. Conclusion: Eravacycline is an effective new option for use in complicated intra-abdominal infections, and in particular, for the treatment of extended-spectrum ß-lactamase- and carbapenem-resistant Enterobacteriaceae-expressing organisms.

Eravacycline for the treatment of complicated intra-abdominal infections.

Introduction: Complicated intra-abdominal infections (cIAIs) are among the most frequent infections, contributing to significant morbidity and healthcare costs. Several medical needs remain unmet, related to the pharmacokinetic capacities of the available drugs and their limited spectrum of activity for targeting multidrug-resistant Gram-negative and Gram-positive bacteria. Eravacycline, a new synthetic fluorocycline, could have useful properties in cIAIs.Areas covered: The antimicrobial activity of eravacycline against the microorganisms most frequently cultured in cIAIs has been confirmed in worldwide panels of clinical isolates, including enterococci, ESBL-producing Enterobacteriaceae, Acinetobacter baumannii and anaerobes. Pharmacokinetic data demonstrate interesting characteristics with good tissue concentrations including biliary tract and digestive tissues. At a conventional dosage of 1 mg/kg q12h, no adjustment is required on the basis of race or gender, or in elderly (≥ 65 years old) patients, patients with renal impairment or patients undergoing hemodialysis. Phase 2 and 3 trials assessing the clinical efficacy and safety of eravacycline demonstrated non-inferiority versus carbapenems and a good safety profile.Expert opinion: Eravacycline may be particularly suitable for the treatment of cIAIs. Results from clinical trials and real-world data are now expected in specific subgroups of patients to confirm the safety profile and efficacy observed in registration trials.

Safety and Efficacy of Ceftazidime-Avibactam Plus Metronidazole in the Treatment of Children ≥3 Months to <18 Years With Complicated Intra-Abdominal Infection: Results From a Phase 2, Randomized, Controlled Trial.

BACKGROUND: Ceftazidime-avibactam plus metronidazole is effective in the treatment of complicated intra-abdominal infection (cIAI) in adults. This single-blind, randomized, multicenter, phase 2 study (NCT02475733) evaluated the safety, efficacy and pharmacokinetics of ceftazidime-avibactam plus metronidazole in children with cIAI. METHODS: Hospitalized children (≥3 months to <18 years) with cIAI were randomized 3:1 to receive intravenous ceftazidime-avibactam plus metronidazole, or meropenem, for a minimum of 72 hours (9 doses), with optional switch to oral therapy thereafter for a total treatment duration of 7-15 days. Safety and tolerability were assessed throughout the study, along with clinical and microbiologic outcomes, and pharmacokinetics. A blinded observer determined adverse event (AE) causality, and clinical outcomes up to the late follow-up visit. RESULTS: Eighty-three children were randomized and received study drug (61 ceftazidime-avibactam plus metronidazole and 22 meropenem); most (90.4%) had a diagnosis of appendicitis. Predominant Gram-negative baseline pathogens were Escherichia coli (79.7%) and Pseudomonas aeruginosa (33.3%); 2 E. coli isolates were ceftazidime-non-susceptible. AEs occurred in 52.5% and 59.1% of patients in the ceftazidime-avibactam plus metronidazole and meropenem groups, respectively. Serious AEs occurred in 8.2% and 4.5% of patients, respectively; none was considered drug related. No deaths occurred. Favorable clinical/microbiologic responses were observed in ≥90% of patients in both treatment groups at end-of-intravenous treatment and test-of-cure visits. CONCLUSIONS: Ceftazidime-avibactam plus metronidazole was well tolerated, with a safety profile similar to ceftazidime alone, and appeared effective in pediatric patients with cIAI due to Gram-negative pathogens, including ceftazidime-non-susceptible strains.

Trend of antibiotics usage for acute pyelonephritis in Korea based on national health insurance data 2010-2014.

BACKGROUND: The objective of this study is to describe the changes in prescribing practices of antibiotics to treat acute pyelonephritis (APN) in Korea. METHODS: The claim data base of the Health Insurance Review and Assessment Service in Korea was used to select patients with ICD-10 codes N10 (acute tubulo-interstitial nephritis) or N12 (tubulo-interstitial nephritis, not specified as acute nor chronic) as the primary discharge diagnosis during 2010-2014. Consumption of each class of antibiotics was converted to Defined Daily Dose (DDD)/event. RESULTS: Throughout the five-year period, the average antibiotic consumption were 11.3 DDD per inpatient event and 6.0 DDD per outpatient event. The annual average antibiotic consumption increased for inpatients (P = 0.002), but remained stable for outpatients (P = 0.066). The use of parenteral antibiotics increased for inpatients (P < 0.001), but decreased for outpatients (P = 0.017). As for the the antibiotic classes, 3rd generation cephalosporins (3rd CEPs) was the most commonly prescribed (41.4%) for inpatients, followed by fluoroquinolones (FQs) (28.5%); for outpatient, FQs (54.8%) was the most commonly prescribed, followed by 3rd CEPs (13.1%). The use of 3rd CEPs (P < 0.001), beta-lactam/beta-lactamase inhibitors (P = 0.007), and carbapenems (P < 0.001) increased substantially for the treatment of hospitalized APN patients. In particular, carbapenems use increased 3.1-fold over the 5 years. CONCLUSIONS: Prescription of broad-spectrum antibiotics increased much for the treatment of APN in Korea during 2010-2014.

Eravacycline, a newly approved fluorocycline.

Complicated intra-abdominal infections (cIAIs) are commonly associated with multimicroorganisms and treatment choices are becoming narrower due to developing resistance, especially in the gram-negative Enterobacteriaceae species. Eravacycline is a newly developed, fully synthetic tetracycline derivative that has shown potent broad-spectrum activity against a wide variety of microorganisms, including those such as extended spectrum ß-lactamase producing Enterobacteriaceae and Acinetobacter. Eravacycline has shown activity against many gram-positive organisms such as methicillin-resistant S. aureus and vancomycin resistant Enterococcus faecalis and Enterococcus faecium (VRE), gram-negative organisms such as Escherichia coli, and anaerobic species of microorganisms such as Bacteroides. This fluorocycline has been compared to ertapenem and meropenem for the treatment of complicated intra-abdominal infections and levofloxacin for the treatment of complicated urinary tract infections. Eravacycline was shown to be noninferior to ertapenem but did not meet noninferiority criteria in comparison to levofloxacin. Oral and IV formulations on eravacycline were tested in clinical trials, but at this time, only the IV formulation is FDA approved. Eravacycline has been noted to have a half-life of 20 h with protein binding around 80%; AUC over minimum inhibitory concentration (MIC) has also been shown to be eravacycline's best predictor of efficacy. Of note, eravacycline does not require any renal dose adjustments, as the majority of its clearance is by nonrenal pathways.

The 2018 Lebanese Society of Infectious Diseases and Clinical Microbiology Guidelines for the use of antimicrobial therapy in complicated intra-abdominal infections in the era of antimicrobial resistance.

BACKGROUND: The Lebanese Society of Infectious Diseases and Clinical Microbiology (LSIDCM) is involved in antimicrobial stewardship. In an attempt at guiding clinicians across Lebanon in regards to the proper use of antimicrobial agents, members of this society are in the process of preparing national guidelines for common infectious diseases, among which are the guidelines for empiric and targeted antimicrobial therapy of complicated intra-abdominal infections (cIAI). The aims of these guidelines are optimizing patient care based on evidence-based literature and local antimicrobial susceptibility data, together with limiting the inappropriate use of antimicrobials thus decreasing the emergence of antimicrobial resistance (AMR) and curtailing on other adverse outcomes. METHODS: Recommendations in these guidelines are adapted from other international guidelines but modeled based on locally derived susceptibility data and on the availability of pharmaceutical and other resources. RESULTS: These guidelines propose antimicrobial therapy of cIAI in adults based on risk factors, site of acquisition of infection, and clinical severity of illness. We recommend using antibiotic therapy targeting third-generation cephalosporin (3GC)-resistant gram negative organisms, with carbapenem sparing as much as possible, for community-acquired infections when the following risk factors exist: prior (within 90 days) exposure to antibiotics, immunocompromised state, recent history of hospitalization or of surgery and invasive procedure all within the preceding 90 days. We also recommend antimicrobial de-escalation strategy after culture results. Prompt and adequate antimicrobial therapy for cIAI reduces morbidity and mortality; however, the duration of therapy should be limited to no more than 4 days when adequate source control is achieved and the patient is clinically stable. The management of acute pancreatitis is conservative, with a role for antibiotic therapy only in specific situations and after microbiological diagnosis. The use of broad-spectrum antimicrobial agents including systemic antifungals and newly approved antibiotics is preferably restricted to infectious diseases specialists. CONCLUSION: These guidelines represent a major step towards initiating a Lebanese national antimicrobial stewardship program. The LSIDCM emphasizes on development of a national AMR surveillance network, in addition to a national antibiogram for cIAI stratified based on the setting (community, hospital, unit-based) that should be frequently updated.

Monitoring the antimicrobial susceptibility of Gram-negative organisms involved in intraabdominal and urinary tract infections recovered during the SMART study (Spain, 2016 and 2017).

OBJECTIVE: Continuous antimicrobial resistance surveillance is recommended by Public Health authorities. We up-dated data from the SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance study in Spain. METHODS: The antimicrobial susceptibility data and extended-spectrum beta-lactamase (ESBL) production in isolates recovered from intra-abdominal (IAI) (n=1,429) and urinary tract (UTI) (n=937) infections during the 2016- 2017 SMART study in 10 Spanish hospitals were analysed. RESULTS: Escherichia coli was the most frequently microorganism isolated (48.3% and 53.7%) followed by Klebsiella spp. (11.5% and 21.9%) in IAIs and UTIs, respectively. Figures for Pseudomonas aeruginosa were 9.0% and 6.1%, being more frequently recovered from patients with nosocomial infections. Overall, 9.9% (IAI) and 14.0% (UTI) of E. coli, Klebsiella spp. and Proteus mirabilis isolates were ESBL-producers, being Klebsiella pneumoniae (34.5%) from UTI of nosocomial origin the most frequent. ESBL-producers were higher in patients >60 years in both IAIs and UTIs. As in previous years, amikacin (96.3%-100% susceptibility), ertapenem (84.2%-100%) and imipenem (70.3%- 100%) were the most active antimicrobials tested among Enterobacterales species. The activity of amoxicillin-clavulanic, piperacillin-tazobactam, and ciprofloxacin susceptibility was lower, particularly among ESBL-producers. Ertapenem susceptibility (88.9%-100%) was retained in ESBL-E. coli isolates that were resistant to these antimicrobials but decreased (28.6%-100%) in similar isolates of K. pneumoniae. CONCLUSIONS: Continuous antimicrobial resistance surveillance from the SMART study reveals overall maintenance of ESBL-producers in Spain, although with higher presence in isolates from UTIs than from IAIs. Moreover, ertapenem activity was high in E. coli irrespective of ESBL production but decreased in K. pneumoniae, particularly among ESBL-producers.

Antimicrobial susceptibilities of specific syndromes created with organ-specific weighted incidence antibiograms (OSWIA) in patients with intra-abdominal infections.

BACKGROUND: The aim was to evaluate the value of organ-specific weighted incidence antibiogram (OSWIA) percentages for bacterial susceptibilities of Gram-negative bacteria (GNB) collected from intra-abdominal infections (IAIs) during SMART 2010-2014. METHODS: We retrospectively calculated the OSWIA percentages that would have been adequately covered by 12 common antimicrobials based on the bacterial compositions found in the appendix, peritoneum, colon, liver, gall bladder and pancreas. RESULTS: The ESBL positive rates were 65.7% for Escherichia coli, 36.2% for Klebsiella pneumoniae, 42.9% for Proteus mirabilis and 33.1% for Klebsiella oxytoca. Escherichia coli were mainly found in the appendix (76.8%), but less so in the liver (32.4%). Klebsiella pneumoniae constituted 45.2% of the total liver pathogenic bacteria and 15.2-20.8% were found in 4 other organs, except the colon and appendix (< 10%). The percentages of Pseudomonas aeruginosa infections were higher in the gall bladder, intra-abdominal abscesses, pancreas and colon (10.2-13.2%) and least (5.4%) in the appendix. The susceptibilities of hospital acquired (HA) and community acquired (CA) IAI isolates from appendix, gall bladder and liver showed ≥80% susceptibilities to amikacin (AMK), imipenem (IPM), piperacillin-tazobactam (TZP) and ertapenem (ETP), while the susceptibility of isolates in abscesses and peritoneal fluid showed ≥80% susceptibility only to amikacin (AMK) and imipenem (IPM). In colon CA IAI isolates susceptibilities did not reach 80% for AMK and ETP, and in pancreatic IAIs susceptibilities of HA GNBs did not reach 80% to AMK, TZP and ETP, and CA GNBs to IMP and ETP. In addition, besides circa 80% susceptibility of HA and CA IAI isolates from appendix to cefoxitin (FOX), IAI isolates from all other organs had susceptibilities between 7.6 and 67.9% to all cephalosporins tested, 28.3-75.2% to fluoroquinolones and 7.6-51.0% to ampicillin-sulbactam (SAM), whether they were obtained from CA or HA infections. CONCLUSION: The calculated OSWIA susceptibilities were specific for different organs in abdominal infections.

Clinical activity of ceftazidime/avibactam against MDR Enterobacteriaceae and Pseudomonas aeruginosa: pooled data from the ceftazidime/avibactam Phase III clinical trial programme.

Objectives: This analysis evaluated the clinical activity of ceftazidime/avibactam against MDR Enterobacteriaceae and Pseudomonas aeruginosa isolates pooled from the adult Phase III clinical trials in patients with complicated intra-abdominal infection (cIAI), complicated urinary tract infection (cUTI) or nosocomial pneumonia (NP) including ventilator-associated pneumonia (VAP). Methods: Baseline isolates from five Phase III randomized controlled trials of ceftazidime/avibactam versus predominantly carbapenem comparators in patients with cIAI (RECLAIM 1 and 2; NCT01499290 and RECLAIM 3; NCT01726023), cUTI (RECAPTURE 1 and 2; NCT01595438 and NCT01599806), NP including VAP (REPROVE; NCT01808092) and cIAI or cUTI caused by ceftazidime-non-susceptible Gram-negative pathogens (REPRISE; NCT01644643) were tested for MDR status and susceptibility to ceftazidime/avibactam and carbapenem-based comparators using CLSI broth microdilution methodology. Microbiological and clinical responses for patients with ≥1 MDR Enterobacteriaceae or P. aeruginosa isolate were assessed at the test-of-cure (TOC) visit. Results: In the pooled microbiologically modified ITT population, 1051 patients with MDR Enterobacteriaceae and 95 patients with MDR P. aeruginosa isolates were identified. Favourable microbiological response rates at TOC for all MDR Enterobacteriaceae and MDR P. aeruginosa were 78.4% and 57.1%, respectively, for ceftazidime/avibactam and 71.6% and 53.8%, respectively, for comparators. The proportions of patients with ≥1 MDR isolate who were clinically cured at TOC were similar in the ceftazidime/avibactam (85.4%) and comparator (87.9%) arms. Conclusions: Ceftazidime/avibactam demonstrated similar clinical efficacy to predominantly carbapenem comparators against MDR Enterobacteriaceae and P. aeruginosa, and may be a suitable alternative to carbapenem-based therapies for cIAI, cUTI and NP/VAP caused by MDR Gram-negative pathogens.

Ceftolozane/tazobactam dose regimens in severely/morbidly obese patients with complicated intra-abdominal infection or complicated urinary tract infection.

Ceftolozane/tazobactam is approved for treatment of complicated intra-abdominal infection (cIAI) and complicated urinary tract infection (cUTI) with renal function-based dose adjustment. Given that creatinine clearance, body weight and sex are highly correlated in severely/morbidly obese patients, this study investigated whether approved dosing regimens for ceftolozane/tazobactam are appropriate in severely/morbidly obese patients based on simulated pharmacokinetic/pharmacodynamic target attainment, with confirmation from observed clinical outcomes data from the phase 3 clinical development programme. Using a previously published population pharmacokinetic model, 1000 patients were randomly sampled from an internal pooled database of 201 severely/morbidly obese patients (BMI ≥ 35 kg/m2) and were used for Monte Carlo simulation to test whether the labelled dose regimens can achieve ≥90% probability of a target of 32.2% (1-log kill) time above free ceftolozane concentration against pathogens at an MIC up to 8 mg/L. Clinical outcomes data for severely/morbidly obese patients with cIAI or cUTI from pivotal phase 3 studies were summarised to calculate clinical and composite cure rates as a complimentary support. With the approved renal function-based dosing regimens, >90% target attainment of bactericidal activity was achieved at MICs up to 8 mg/L in the simulated severely/morbidly obese patients with cIAI or cUTI, similar to target attainment in non-obese patients and further confirmed by phase 3 outcomes where cure rates in severely/morbidly obese patients and non-obese patients are similar. Approved dosing regimens of ceftolozane/tazobactam, adjusted according to renal function, can achieve adequate target attainment and high clinical cure rates in severely/morbidly obese patients with cIAI or cUTI.

Clinical experience with ceftazidime/avibactam for treatment of antibiotic-resistant organisms other than Klebsiella pneumoniae.

BACKGROUND: Ceftazidime/avibactam is a newly approved ß-lactam/ß-lactamase inhibitor combination with activity against antibiotic-resistant Gram-negative organisms, including many carbapenem-resistant strains. Although this agent may offer a promising treatment option for serious infections with limited alternatives available, clinical experience with ceftazidime/avibactam in treatment of infections caused by multidrug-resistant Gram-negative organisms other than Klebsiella pneumoniae is limited. METHODS: A retrospective case series was performed to evaluate patients treated with ceftazidime/avibactam for infections caused by organisms other than K. pneumoniae at our institution over a 1-year period. Patients aged at least 18 years who received at least one dose of ceftazidime/avibactam were eligible for inclusion. Clinical and microbiological data were collected, and investigators assessed adverse effects, microbiological cure, clinical success, and 30-day in-hospital mortality following completion of ceftazidime/avibactam therapy. RESULTS: Ten patients were included. The most common index infection was pneumonia (n = 6/13, 46%) and the most frequently isolated organism was Pseudomonas aeruginosa (n = 8/21, 38%). Fifty percent of patients received ceftazidime/avibactam as monotherapy. Microbiological cure was achieved in 67% (n = 6/9) of patients and 70% (n = 7/10) of patients met criteria for clinical success. The 30-day in-hospital mortality rate was 30%. No patients experienced adverse events because of ceftazidime/avibactam therapy. CONCLUSIONS: For infections caused by antibiotic-resistant Gram-negative organisms other than K. pneumoniae, clinical and microbiological success rates for patients treated with ceftazidime/avibactam were similar to those that have been reported for K. pneumoniae. Ceftazidime/avibactam appears to be a promising treatment option for infections caused by a variety of resistant Gram-negative organisms when limited alternatives exist.

Moxifloxacin in Pediatric Patients With Complicated Intra-abdominal Infections: Results of the MOXIPEDIA Randomized Controlled Study.

BACKGROUND: This study was designed to evaluate primarily the safety and also the efficacy of moxifloxacin (MXF) in children with complicated intra-abdominal infections (cIAIs). METHODS: In this multicenter, randomized, double-blind, controlled study, 451 pediatric patients aged 3 months to 17 years with cIAIs were treated with intravenous/oral MXF (N = 301) or comparator (COMP, intravenous ertapenem followed by oral amoxicillin/clavulanate; N = 150) for 5 to 14 days. Doses of MXF were selected based on the results of a Phase 1 study in pediatric patients (NCT01049022). The primary endpoint was safety, with particular focus on cardiac and musculoskeletal safety; clinical and bacteriologic efficacy at test of cure was also investigated. RESULTS: The proportion of patients with adverse events (AEs) was comparable between the 2 treatment arms (MXF: 58.1% and COMP: 54.7%). The incidence of drug-related AEs was higher in the MXF arm than in the COMP arm (14.3% and 6.7%, respectively). No cases of QTc interval prolongation-related morbidity or mortality were observed. The proportion of patients with musculoskeletal AEs was comparable between treatment arms; no drug-related events were reported. Clinical cure rates were 84.6% and 95.5% in the MXF and COMP arms, respectively, in patients with confirmed pathogen(s) at baseline. CONCLUSIONS: MXF treatment was well tolerated in children with cIAIs. However, a lower clinical cure rate was observed with MXF treatment compared with COMP. This study does not support a recommendation of MXF for children with cIAIs when alternative more efficacious antibiotics with better safety profile are available.

Efficacy ratio: A tool to enhance optimal antimicrobial use for intra-abdominal infections.

BACKGROUND: Antimicrobial resistance and inappropriate antibiotic regimen hamper a favorable outcome in intra-abdominal infections. Clinicians rely on the minimum inhibitory concentration (MIC) value to choose from the susceptible antimicrobials. However, the MIC values cannot be directly compared between the different antibiotics because their breakpoints are different. For that reason, efficacy ratio (ER), a ratio of susceptible MIC breakpoint and MIC of isolate, can be used to choose the most appropriate antimicrobial. MATERIALS AND METHODS: A prospective, observational study conducted during 2015 and 2016 included 356 Escherichia coli and 158 Klebsiella spp. isolates obtained from the intra-abdominal specimens. MIC was determined by microbroth dilution method, and ER of each antibiotic was calculated for all the isolates. RESULTS: For both E. coli and Klebsiella spp., ertapenem, amikacin, and piperacillin/tazobactam had the best activities among their respective antibiotic classes. DISCUSSION: This is the first study calculating ER for deciding empiric treatment choices. ER also has a potential additional value in choosing the use of susceptible drugs as monotherapy or combination therapy. A shift in ERs over a period of time tracks rising MIC values and predicts antimicrobial resistance development. CONCLUSION: Estimation of ER could be a meaningful addition for the interpretation of an antimicrobial susceptibility report, thus helping the physician to choose the best among susceptible antimicrobials for patient management.

Do bacteria isolated from ICU patients 'ESKAPE' antibiotic treatment? In vitro susceptibility of the Enterobacteriaceae family to tigecycline.

BACKGROUND: Enterobacteriaceae are currently causing the majority of healthcare-associated infections (HAI) and simultaneously expressing increasing levels of antibiotic resistance. The purpose of this study is to assess the in vitro sensitivity of MDR strains from the family Enterobacteriaceae to tigecycline in relation to their origin from patients hospitalized in intensive care units (ICUs) and non-ICUs. METHODS: The study involved 156 clinically significant strains of the Enterobacteriaceae family isolated from patients with complicated intraabdominal infections (cIAIs) and/or complicated skin and skin structure infections (cSSSIs) hospitalized in ICUs and other surgical departments. Tigecycline MICs were determined by Etest. RESULTS: The highest percentage of tigecycline non-susceptible (intermediate + resistant strains) in vitro strains among the Enterobacteriaceae species were observed for Serratia spp. 77.3%, followed by Citrobacter spp. (76.9%) and Enterobacter spp. (70%); whereas K. pneumoniae and E. coli showed 73-73.8% tigecycline susceptibility rates. CONCLUSION: Tigecycline demonstrates a high level of antimicrobial in vitro activity when tested against E. coli and K. pneumoniae, even those with the ESBL-phenotype. Tigecycline retained activity against merely 22-30% of Enterobacter, Citrobacter and Serratia genera.

EUropean prospective cohort study on Enterobacteriaceae showing REsistance to CArbapenems (EURECA): a protocol of a European multicentre observational study.

INTRODUCTION: The rapid worldwide spread of carbapenem-resistant Enterobacteriaceae (CRE) constitutes a major challenge. The aim of the EUropean prospective cohort study on Enterobacteriaceae showing REsistance to CArbapenems (EURECA), which is part of the Innovative Medicines Initiative Joint Undertaking (IMI JU) funded COMBACTE-CARE project, is to investigate risk factors for and outcome determinants of CRE infections to inform randomised clinical trial designs and to provide a historical cohort that could eventually be used for future comparisons with new drugs targeting CRE. METHODS: A multicentre (50 sites), multinational (11 European countries), analytical observational project was designed, comprising 3 studies. The aims of study 1 (a prospective cohort study) include characterising the features, clinical management and outcomes of hospitalised patients with intra-abdominal infection, pneumonia, complicated urinary tract infections and bloodstream infections caused by CRE (202 patients in each group). The main outcomes will be 30-day all-cause mortality and clinical response. Study 2 (a nested case-control study) will identify the risk factors for target infections caused by CRE; 248 selected patients from study 1 will be matched with patients with carbapenem-susceptible Enterobacteriaceae (1:1) and with hospitalised patients (1:3) and will provide a historical cohort of patients with CRE infections. Study 3 (a matched cohort study) will follow patients in study 2 in order to assess mortality, length of stay and hospital costs associated with CRE. All patients will be followed for 30 days. Different, up-to-date statistical methods will be applied to come to unbiased estimates for all 3 studies. ETHICS AND DISSEMINATION: Before-study sites will be initiated, approval will be sought from appropriate regulatory agencies and local Ethics Committees of Research or Institutional Review Boards (IRBs) to conduct the study in accordance with regulatory requirements. This is an observational study and therefore no intervention in the diagnosis, management or treatment of the patients will be required on behalf of the investigation. Any formal presentation or publication of data collected from this study will be considered as a joint publication by the participating physician(s) and will follow the recommendations of the International Committee of Medical Journal Editors (ICMJE) for authorship. TRIAL REGISTRATION NUMBER: NCT02709408.