nov

A comprehensive microbial surveillance was conducted at NASA's Mars 2020 spacecraft assembly facility (SAF), where whole-genome sequencing (WGS) of 110 bacterial strains was performed. One isolate, designated 179-BFC-A-HST, exhibited less than 80% average nucleotide identity (ANI) to known species, suggesting a novel organism. This strain demonstrated high-level resistance [minimum inhibitory concentration (MIC) >256 mg/L] to third-generation cephalosporins, including ceftazidime, cefpodoxime, combination ceftazidime/avibactam, and the fourth-generation cephalosporin cefepime. The results of a comparative genomic analysis revealed that 179-BFC-A-HST is most closely related to Virgibacillus halophilus 5B73CT, sharing an ANI of 78.7% and a digital DNA-DNA hybridization (dDDH) value of 23.5%, while their 16S rRNA gene sequences shared 97.7% nucleotide identity. Based on these results and the recent recognition that the genus Virgibacillus is polyphyletic, strain 179-BFC-A-HST is proposed as a novel species of a novel genus, Tigheibacillus jepli gen. nov., sp. nov (type strain 179-BFC-A-HST = DSM 115946T = NRRL B-65666T), and its closest neighbor, V. halophilus, is proposed to be reassigned to this genus as Tigheibacillus halophilus comb. nov. (type strain 5B73CT = DSM 21623T = JCM 21758T = KCTC 13935T). It was also necessary to reclassify its second closest neighbor Virgibacillus soli, as a member of a novel genus Paracerasibacillus, reflecting its phylogenetic position relative to the genus Cerasibacillus, for which we propose Paracerasibacillus soli comb. nov. (type strain CC-YMP-6T = DSM 22952T = CCM 7714T). Within Amphibacillaceae (n = 64), P. soli exhibited 11 antibiotic resistance genes (ARG), while T. jepli encoded for 3, lacking any known β-lactamases, suggesting resistance from variant penicillin-binding proteins, disrupting cephalosporin efficacy. P. soli was highly resistant to azithromycin (MIC >64 mg/L) yet susceptible to cephalosporins and penicillins.

IMPORTANCE

The significance of this research extends to understanding microbial survival and adaptation in oligotrophic environments, such as those found in SAF. Whole-genome sequencing of several strains isolated from Mars 2020 mission assembly cleanroom facilities, including the discovery of the novel species Tigheibacillus jepli, highlights the resilience and antimicrobial resistance (AMR) in clinically relevant antibiotic classes of microbes in nutrient-scarce settings. The study also redefines the taxonomic classifications within the Amphibacillaceae family, aligning genetic identities with phylogenetic data. Investigating ARG and virulence factors (VF) across these strains illuminates the microbial capability for resistance under resource-limited conditions while emphasizing the role of human-associated VF in microbial survival, informing sterilization practices and microbial management in similar oligotrophic settings beyond spacecraft assembly cleanrooms such as pharmaceutical and medical industry cleanrooms.

Full-dose challenge of moderate, severe, and unknown beta-lactam allergies in the emergency department

OBJECTIVE

This study aims to assess the outcome of challenging documented moderate, severe, or unknown beta-lactam allergies with full dose administration of a beta-lactam antibiotic in emergency department (ED) patients admitted for acute bacterial infection.

METHODS

A single-center, retrospective, descriptive study of adult patients challenged with a full dose of beta-lactam in the ED from January 2021 to December 2022 was conducted. Included patients had at least one documented moderate, severe, or unknown beta-lactam allergy in the electronic medical record (EMR) without documentation of prior tolerance. Patient demographics, prior beta-lactam antibiotic reaction, beta-lactam administered in the ED, inpatient beta-lactam continuation, adverse drug reactions, and updates to allergy profiles were collected. Descriptive statistics for data analysis were performed using SPSS Version 22.

RESULTS

Of the 184 ED encounters with full-dose beta-lactam challenges, five (2.7%) patients with documented moderate, severe, or unknown beta-lactam allergies experienced an allergic reaction after the challenge; one (0.5%) patient had an allergic reaction in the ED, and the remaining four (2.2%) occurred after admission. No anaphylactic reactions occurred. All allergic reactions were limited to mild rash or itching. Most patients (98.9%) were challenged with a cephalosporin. A beta-lactam was continued in 86.4% of cases, and the allergy profile was updated for future utilization in 73.4% of patients.

CONCLUSIONS

This study suggests that full-dose challenge of moderate, severe, or unknown beta-lactam allergies can be safely accomplished in the ED. This approach avoids unnecessary penicillin allergy skin testing and reduces utilization of suboptimal alternative antibiotic regimens.

Genomic epidemiology of third-generation cephalosporin-resistant Escherichia coli from Argentinian pig and dairy farms reveals animal-specific patterns of co-resistance and resistance mechanisms

Control measures are being introduced globally to reduce the prevalence of antibiotic resistance (ABR) in bacteria on farms. However, little is known about the current prevalence and molecular ecology of ABR in bacterial species with the potential to be key opportunistic human pathogens, such as Escherichia coli, on South American farms. Working with 30 dairy cattle farms and 40 pig farms across two provinces in central-eastern Argentina, we report a comprehensive genomic analysis of third-generation cephalosporin-resistant (3GC-R) E. coli, which were recovered from 34.8% (cattle) and 47.8% (pigs) of samples from fecally contaminated sites. Phylogenetic analysis revealed substantial diversity suggestive of long-term horizontal and vertical transmission of 3GC-R mechanisms. CTX-M-15 and CTX-M-2 were more often produced by isolates from dairy farms, while CTX-M-8 and CMY-2 and co-carriage of amoxicillin/clavulanate resistance and florfenicol resistance were more common in isolates from pig farms. This suggests different selective pressures for antibiotic use in these two animal types. We identified the β-lactamase gene blaROB, which has previously only been reported in the family Pasteurellaceae, in 3GC-R E. coli. blaROB was found alongside a novel florfenicol resistance gene, ydhC, also mobilized from a pig pathogen as part of a new composite transposon. As the first comprehensive genomic survey of 3GC-R E. coli in Argentina, these data set a baseline from which to measure the effects of interventions aimed at reducing on-farm ABR and provide an opportunity to investigate the zoonotic transmission of resistant bacteria in this region.

IMPORTANCE

Little is known about the ecology of critically important antibiotic resistance among bacteria with the potential to be opportunistic human pathogens (e.g., Escherichia coli) on South American farms. By studying 70 pig and dairy cattle farms in central-eastern Argentina, we identified that third-generation cephalosporin resistance (3GC-R) in E. coli was mediated by mechanisms seen more often in certain species and that 3GC-R pig E. coli were more likely to be co-resistant to florfenicol and amoxicillin/clavulanate. This suggests that on-farm antibiotic usage is key to selecting the types of E. coli present on these farms. 3GC-R E. coli and 3GC-R plasmids were diverse, suggestive of long-term circulation in this region. We identified the de novo mobilization of the resistance gene blaROB from pig pathogens into E. coli on a novel mobile genetic element, which shows the importance of surveying poorly studied regions for antibiotic resistance that might impact human health.

Genome sequence of an Acinetobacter pittii strain obtained from a red-lored parrot with pneumonia

Acinetobacter pittii 978-A_19 was obtained from a parrot with pneumonia. It is resistant to ampicillin, carbenicillin, cephalosporins, clindamycin, and trimethoprim + sulfamethoxazole. The genome encodes a new blaADC allele, a blaOXA-502 gene, possesses several virulence genes related to adherence and biofilm formation, and has types I, II, and IV secretion systems.

Predicting Beta-Lactam Target Non-Attainment in ICU Patients at Treatment Initiation: Development and External Validation of Three Novel (Machine Learning) Models

In the intensive care unit (ICU), infection-related mortality is high. Although adequate antibiotic treatment is essential in infections, beta-lactam target non-attainment occurs in up to 45% of ICU patients, which is associated with a lower likelihood of clinical success. To optimize antibiotic treatment, we aimed to develop beta-lactam target non-attainment prediction models in ICU patients. Patients from two multicenter studies were included, with intravenous intermittent beta-lactam antibiotics administered and blood samples drawn within 12-36 h after antibiotic initiation. Beta-lactam target non-attainment models were developed and validated using random forest (RF), logistic regression (LR), and naïve Bayes (NB) models from 376 patients. External validation was performed on 150 ICU patients. We assessed performance by measuring discrimination, calibration, and net benefit at the default threshold probability of 0.20. Age, sex, serum creatinine, and type of beta-lactam antibiotic were found to be predictive of beta-lactam target non-attainment. In the external validation, the RF, LR, and NB models confirmed good discrimination with an area under the curve of 0.79 [95% CI 0.72-0.86], 0.80 [95% CI 0.73-0.87], and 0.75 [95% CI 0.67-0.82], respectively, and net benefit in the RF and LR models. We developed prediction models for beta-lactam target non-attainment within 12-36 h after antibiotic initiation in ICU patients. These online-accessible models use readily available patient variables and help optimize antibiotic treatment. The RF and LR models showed the best performance among the three models tested.

Impact of Intermediate Susceptibility to Penicillin on Antimicrobial Treatment and Outcomes of Endocarditis Caused by Viridans and Gallolyticus Group Streptococci

BACKGROUND

Evidence supporting combination treatment with a beta-lactam plus an aminoglycoside (C-BA) for endocarditis caused by viridans and gallolyticus group streptococci (VGS-GGS) with intermediate susceptibility to penicillin (PENI-I) is lacking. We assessed the clinical characteristics and outcomes of PEN-I VGS-GGS endocarditis and compared the effectiveness and safety of C-BA with third-generation cephalosporin monotherapy.

METHODS

Retrospective analysis of prospectively collected data of a cohort of definite endocarditis caused by penicillin-susceptible and PENI-I VGS-GGS (penicillin minimum inhibitory concentration ranging from 0.25 to 2 mg/L) between 2008 and 2018 in 40 Spanish hospitals. We compared cases treated with monotherapy or with C-BA and performed multivariable analyses of risk factors for in-hospital and 1-year mortality.

RESULTS

A total of 914 consecutive cases of definite endocarditis caused by VGS-GGS with complete or intermediate susceptibility to penicillin were included. A total of 688 (75.3%) were susceptible to penicillin and 226 (24.7%) were PENI-I. Monotherapy was used in 415 (45.4%) cases (cephalosporin in 331 cases) and 499 (54.6%) cases received C-BA. In-hospital mortality was 11.9%, and 190 (20.9%) patients developed acute kidney injury. Heart failure (odds ratio [OR]: 6.06; 95% confidence interval [CI]: 1.37-26.87; P = .018), central nervous system emboli (OR: 9.83; 95% CI: 2.17-44.49; P = .003) and intracardiac abscess (OR: 13.47; 95% CI: 2.24-81.08; P = .004) were independently associated with in-hospital mortality among PEN-I VGS-GGS cases, while monotherapy was not (OR: 1.01; 95% CI: .26-3.96; P = .982).

CONCLUSIONS

Our findings support the use of cephalosporin monotherapy in PEN-I VGS-GGS endocarditis in order to avoid nephrotoxicity without adversely affecting patient outcomes.

Ceftiofur use and antimicrobial stewardship in the horse

Equine practitioners require recommendations that support antimicrobial stewardship and avoid generating resistance to medically important antibiotics. This review examines current inadequacies in antimicrobial stewardship standards within the veterinary community, related to antimicrobial categorisation and prescribing practices. Resistance to cephalosporin antibiotics in horses is also described. Properties of cephalosporin antibiotics are outlined and equine-specific studies of ceftiofur, a third-generation cephalosporin antibiotic with medical importance, are detailed. Readers are provided with recommendations that encourage appropriate use of ceftiofur, citing the evidence available in horses.

Comparison of Outcomes in Neonates Receiving Cefepime or Ceftazidime

OBJECTIVES

Cefepime and ceftazidime are alternatives to cefotaxime for management of Gram-negative infections in neonates. The objective was to evaluate neonatal outcomes when receiving cefepime or ceftazidime.

METHODS

This was a single center, retrospective analysis of neonates exposed to at least 24 hours of cefepime or ceftazidime between June 1, 2018, and June 1, 2021. The primary outcome was incidence of culture-positive, late-onset sepsis after initial exposure. Secondary outcomes included culture-negative, respiratory, urinary tract, and resistant infections; necrotizing enterocolitis; length of stay; age at discharge; mortality; and adverse effects.

RESULTS

A total of 105 neonates were included (cefepime, n = 50; ceftazidime, n = 55). Baseline characteristics were similar except more cumulative days of antibiotics (25.0 [IQR, 9.3-47.0] versus 9.0 [IQR, 4.0-23.5], p = 0.01), central line days (11.0 [IQR, 6.0-40.0] versus 6.5 [IQR, 0.0-11.5], p = 0.001), and ventilator days (13.0 [IQR, 2.3-48.0] versus 4.0 [IQR, 0.0-25.0], p = 0.02) were found in the cefepime group than in the ceftazidime group. There was no difference in culture-positive sepsis after the initial antibiotic course (8.0% versus 3.6%, p = 0.42). Statistical differences were seen in select secondary outcomes including treated respiratory infections (16.0% versus 1.8%, p = 0.01), length of stay greater than 30 days (72.0% versus 50.9%, p = 0.03), and mortality (26.0% versus 9.1%, p = 0.02). These differences were not observed in analyses adjusted for ventilator days.

CONCLUSIONS

This analysis found no difference in culture-positive sepsis in neonates exposed to cefepime versus ceftazidime. Moreover, there were no differences in secondary outcomes in adjusted analyses. Further research is needed to assess neonatal outcomes in a larger analysis.

Efficacy of ceftobiprole in a murine model of bacteremia and disseminated infection

Introduction. Ceftobiprole is an advanced-generation broad-spectrum parenteral cephalosporin with activity against MSSA and MRSA.Gap Statement. Ceftobiprole is not currently approved for use to treat S. aureus bacteremia and phase three clinical trials are taking place. Drug approval requires further pre-clinical evidence to support this new indication.Aim. The aim of this study was to evaluate the efficacy of ceftobiprole at the human equivalent efficacious exposure (considering a 500 mg q8h dosing regimen infused over 2 h) against MSSA and MRSA strains in a neutropenic murine model of bacteremia and disseminated infection.Methodology. Two bioluminescent-tagged strains (one MSSA and one MRSA strain) were selected based on their in vitro susceptibility and in vivo growth profiles. Bacterial c.f.u. counts in the blood, lung, kidney, and liver were determined 48 h post-infection or after death. The bioluminescent-tag allowed the visualization of the real-time effects of ceftobiprole therapy compared to the natural progression of the infection in untreated controls.Results. Treatment with ceftobiprole resulted in a significant reduction of the bacterial load with the bioluminescence reduced by 2-log units and bacterial c.f.u. counts reduced by 3- to 6-log units, depending on the organ and bacterial strain. Survival was 100 % in the ceftobiprole-treated group compared to only 0-20 % survival in the untreated control animals for both strains tested.Conclusion. These results suggest that treatment with ceftobiprole using a 500 mg q8h dosing regimen studied in several successful phase three trials, has potential as an antibiotic therapy to treat bacteremia and associated disseminated infections caused by either methicillin-susceptible or methicillin-resistant strains of S. aureus.

Impact of antimicrobial stewardship interventions on peripartum antibiotic prescribing in patients with penicillin allergy

BACKGROUND

Beta-lactam antibiotics (eg, penicillins, cephalosporins, and carbapenems) are preferred for group B streptococcus prophylaxis, intra-amniotic infection, and cesarean surgical site infection prophylaxis. Non-beta-lactam alternatives are associated with inferior efficacy and contribute to higher rates of surgical site infection and longer lengths of stay. Most patients who report a penicillin allergy can tolerate penicillins without any adverse reaction. There are low rates of cross-reactivity between penicillins and other beta-lactams, including cephalosporins and carbapenems. Efforts to evaluate penicillin allergy and promote the use of beta-lactams are needed.

OBJECTIVE

This study aimed to evaluate whether an antimicrobial stewardship intervention improved the use of first-line antibiotics for peripartum indications in patients with a reported penicillin allergy, following updates to institutional guidelines.

STUDY DESIGN

This was a retrospective study of adult patients presenting for vaginal or cesarean delivery at 2 hospitals within a healthcare system. Patients received at least 1 dose of antibiotics for a peripartum indication between May 1, 2018, and October 31, 2018 (preintervention group) and May 1, 2020, to October 31, 2020 (postintervention group). The stewardship intervention bundle, which was implemented between March 2019 and April 2020, included updates to institutional antibiotic guidelines, reclassification of severe penicillin allergy, development of obstetrical prophylaxis and treatment order sets, promotion of allergy referral services, and establishment of a physician champion. The primary outcome was the composite rates of patients with reported penicillin allergy who received a preferred antibiotic for a peripartum indication. The secondary measures included maternal and neonatal outcomes.

RESULTS

A total of 192 patients with a history of documented penicillin allergy were evaluated (96 patients in the preintervention group and 96 patients in the postintervention group). Hives were the most commonly reported index symptom in both groups (40/96 [41.7%] vs 39/96 [40.6%]; P=.883). After stewardship interventions, there was a significant increase in the rate of preferred antibiotic use (33/96 [34.3%] vs 81/96 [84.3%]; P<.001). The effect was the greatest in patients with nonsevere allergy (14/76 [18.4%] vs 68/82 [82.9%]; P<.001). There was no difference in the rates of postpartum endometritis, 30-day readmission, 90-day surgical site infection, or neonatal early-onset sepsis between the pre- and postintervention groups. Of note, 1 patient in the postintervention group experienced itching, and another patient developed a rash, both of which resolved with medical management.

CONCLUSION

A comprehensive antibiotic stewardship intervention was associated with a 50% increase in the use of preferred antibiotics for peripartum indications in patients with penicillin allergy. Allergic reactions with first-line beta-lactams were minimal and manageable.

Comparison of Epidemiological Characteristics Between ESBL and Non-ESBL Isolates of Clinically Isolated Escherichia coli from 2014 to 2022: A Single-Center Study

Purpose

This single-center study aims to investigate the epidemiological characteristics of clinically isolated Escherichia coli from 2014 to 2022.

Methods

In vitro drug sensitivity of E. coli to 20 antibiotics was examined using the microbroth dilution method. A total of 7580 clinical E. coli strains were isolated from 2014 to 2022, among which 56.9% were identified as extended spectrum beta-lactamase-producing strains. The data were analyzed using the software WHONET5.6 and the R language platform.

Results

Over the study period, carbapenem resistance rates increased by more than 50% (2022 [1.34%] vs 2014 [0.8%]) and the annual number of isolates showed an upward trend (1264 in 2022 vs 501 in 2014). Drug resistance rates were the highest for penicillin (75-85%) and lowest for imipenem (1%). The resistance rate of strains isolated from male patients and sputum was found to be higher than that of female patients and urine, except for quinolones (p <0.05). The drug resistance rates from high to low were penicillins (75-85%), tetracycline (64%), quinolones (64-67%), sulfamethoxazole (59.3%), cephalosporins (22-72%), aztreonam (34%), chloramphenicol (21%), amikacin (2.8%), colistin (1.4%), meropenem (1.1%), and imipenem (1%). Urine, sputum, and blood accounted for 51%, 16.6%, and 10.6% of the samples, respectively. A greater number of female patients were included more than male patients (4798[63.3%] vs 2782[26.7%]). Patients aged 50-80 accounted for 64.2% of those surveyed.

Conclusion

Carbapenems remain the optimal choice for treating extended spectrum beta-lactamase-producing E. coli infections (sensitivity rate: 98%). Colistin (87.7%) and amikacin (87%) exhibited good antibacterial activities against carbapenem-resistant E. coli. Long-term and continuous epidemiological surveillance of E. coli can facilitate the development of preventive strategies and control policies.

Efficacy of prophylactic antibiotics for preterm premature rupture of membranes: a systematic review and network meta-analysis

OBJECTIVE

Various prophylactic antibiotic regimens are used in the management of preterm premature rupture of membranes. We investigated the efficacy and safety of these regimens in terms of maternal and neonatal outcomes.

DATA SOURCES

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from inception to July 20, 2021.

STUDY ELIGIBILITY CRITERIA

We included randomized controlled trials involving pregnant women with preterm premature rupture of membranes before 37 weeks of gestation and a comparison of ≥2 of the following 10 antibiotic regimens: control/placebo, erythromycin, clindamycin, clindamycin plus gentamicin, penicillins, cephalosporins, co-amoxiclav, co-amoxiclav plus erythromycin, aminopenicillins plus macrolides, and cephalosporins plus macrolides.

METHODS

Two investigators independently extracted published data and assessed the risk of bias with a standard procedure following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Network meta-analysis was conducted using the random-effects model.

RESULTS

A total of 23 studies that recruited a total of 7671 pregnant women were included. Only penicillins (odds ratio, 0.46; 95% confidence interval, 0.27-0.77) had significantly superior effectiveness for maternal chorioamnionitis. Clindamycin plus gentamicin reduced the risk of clinical chorioamnionitis, with borderline significance (odds ratio, 0.16; 95% confidence interval, 0.03-1.00). By contrast, clindamycin alone increased the risk of maternal infection. For cesarean delivery, no significant differences were noted among these regimens.

CONCLUSION

Penicillins remain the recommended antibiotic regimen for reducing maternal clinical chorioamnionitis. The alternative regimen includes clindamycin plus gentamicin. Clindamycin should not be used alone.

An Overview of Cefiderocol's Therapeutic Potential and Underlying Resistance Mechanisms

Antimicrobial resistance continues to increase globally and treatment of difficult-to-treat (DTT) infections, mostly associated with carbapenem-resistant (CR) Pseudomonas aeruginosa, CR Acinetobacter baumannii, and CR- and third-generation-cephalosporins-resistant Enterobacterales remains a challenge for the clinician. The recent approval of cefiderocol has broaden the armamentarium for the treatment of patients with DTT infections. Cefiderocol is a siderophore cephalosporin that has shown excellent antibacterial activity, in part due to its innovative way of cell permeation. It is relatively stable compared to most commonly found carbapenamases. However, some resistant mechanisms to cefiderocol have already been identified and reduced susceptibility has developed during patient treatment, highlighting that the clinical use of cefiderocol must be rational. In this review, we summarize the current available treatments against the former resistant bacteria, and we revise and discuss the mechanism of action of cefiderocol, underlying the biological function of siderophores, the therapeutic potential of cefiderocol, and the mechanisms of resistance reported so far.

Data-Driven Two-Stage Framework for Identification and Characterization of Different Antibiotic-Resistant Escherichia coli Isolates Based on Mass Spectrometry Data

In clinical microbiology, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is frequently employed for rapid microbial identification. However, rapid identification of antimicrobial resistance (AMR) in Escherichia coli based on a large amount of MALDI-TOF MS data has not yet been reported. This may be because building a prediction model to cover all E. coli isolates would be challenging given the high diversity of the E. coli population. This study aimed to develop a MALDI-TOF MS-based, data-driven, two-stage framework for characterizing different AMRs in E. coli. Specifically, amoxicillin (AMC), ceftazidime (CAZ), ciprofloxacin (CIP), ceftriaxone (CRO), and cefuroxime (CXM) were used. In the first stage, we split the data into two groups based on informative peaks according to the importance of the random forest. In the second stage, prediction models were constructed using four different machine learning algorithms-logistic regression, support vector machine, random forest, and extreme gradient boosting (XGBoost). The findings demonstrate that XGBoost outperformed the other four machine learning models. The values of the area under the receiver operating characteristic curve were 0.62, 0.72, 0.87, 0.72, and 0.72 for AMC, CAZ, CIP, CRO, and CXM, respectively. This implies that a data-driven, two-stage framework could improve accuracy by approximately 2.8%. As a result, we developed AMR prediction models for E. coli using a data-driven two-stage framework, which is promising for assisting physicians in making decisions. Further, the analysis of informative peaks in future studies could potentially reveal new insights. IMPORTANCE Based on a large amount of matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) clinical data, comprising 37,918 Escherichia coli isolates, a data-driven two-stage framework was established to evaluate the antimicrobial resistance of E. coli. Five antibiotics, including amoxicillin (AMC), ceftazidime (CAZ), ciprofloxacin (CIP), ceftriaxone (CRO), and cefuroxime (CXM), were considered for the two-stage model training, and the values of the area under the receiver operating characteristic curve (AUC) were 0.62 for AMC, 0.72 for CAZ, 0.87 for CIP, 0.72 for CRO, and 0.72 for CXM. Further investigations revealed that the informative peak m/z 9714 appeared with some important peaks at m/z 6809, m/z 7650, m/z 10534, and m/z 11783 for CIP and at m/z 6809, m/z 10475, and m/z 8447 for CAZ, CRO, and CXM. This framework has the potential to improve the accuracy by approximately 2.8%, indicating a promising potential for further research.

Inaccurate penicillin allergy labels: Consequences, solutions, and opportunities for rhinologists

BACKGROUND

Nasal airway obstruction (NAO) is a highly prevalent disorder. Septal swell body (SSB) hypertrophy is an often-overlooked contributor to NAO. SSB treatment may relieve symptoms of NAO. The objective of this study was to assess the clinical use of a temperature-controlled radiofrequency (TCRF) device to treat SSBs to improve symptoms in adults with NAO.

METHODS

In this prospective, multicenter, open-label, single arm study, patients with severe or extreme NAO related to SSB hypertrophy received bilateral TCRF treatment in the SSB area. The primary endpoint was improvement in Nasal Obstruction Symptom Evaluation (NOSE) scale scores from baseline to 3 months post-procedure. A subset of study patients underwent computed tomography (CT) imaging to evaluate post-treatment changes in SSB size.

RESULTS

Mean NOSE scale scores significantly improved from 73.5 (SD 14.2) at baseline to 27.9 (SD 17.2) at 3 months post-procedure; a reduction of -45.3 (SD 21.4), (95% confidence interval [CI]: -50.4 to -40.1; p< 0.0001): the responder rate was 95.7% (95% CI: 0.88 to 0.99; p < 0.0001). CT evaluation at 3 months showed statistically significant reductions in the SSB with the greatest reduction in the middle thickness: (mean change -3.4 [SD 1.8] millimeters [95% CI: -4.0 to -2.8; p<.0001]). Minimal adverse events with any relationship to the device or procedure were reported, none were serious in nature and no septal perforations occurred.

CONCLUSIONS

This study demonstrates that temperature-controlled radiofrequency treatment of SSB hypertrophy is well-tolerated and effective at reducing both SSB size and symptoms of NAO at 3 months post-treatment.

Clinical significance of preoperative antibiotic use in mild to moderate acute inflammatory gallbladder disease: A randomized controlled trial

BACKGROUND

Many patients receive empirical antibiotics for the prevention of postoperative infectious complications following cholecystectomy due to acute cholecystitis (AC). The purpose of this study was to investigate the clinical significance of preoperative antibiotics in mild to moderate AC patients undergoing emergency laparoscopic cholecystectomy.

METHODS

This was a double-blind, placebo-controlled, randomized study. Patients with AC eligible for emergency laparoscopic cholecystectomy were randomly assigned to an antibiotic or a placebo group. Clinical outcomes including infectious complications were reviewed.

RESULTS

An imputed per-protocol analysis of 234 patients showed that the postoperative infection rate was 8.6% (10 of 116 patients) in the antibiotic group and 7.6% (9 of 118 patients) in the placebo group (absolute difference, 1%; 95% CI: -8.1% to 6.1%; P = .815). Based on a noninferiority margin of 10%, the lack of preoperative antibiotic treatment was not associated with worse clinical outcomes than antibiotic treatment. Surgical site infection was the most common complication among the infectious complications, and there was no significant difference between the two groups (7.8% in the antibiotic group vs 7.6%, in the placebo group, P = .53).

CONCLUSIONS

The absence of prophylactic antibiotics has no significant impact on the incidence of infectious complications in mild to moderated AC.

Cotransfer of resistance to cephalosporins, colistin, and fosfomycin mediated by an IncHI2/pSH16G4928-like plasmid in ESBL-producing monophasic Salmonella Typhimurium strains of pig origin

AIMS

To assess the co-transmission risk of phenotypic and genetic resistance to cephalosporins, colistin, and fosfomycin in Salmonella strains collected along the whole pork production chain.

METHODS AND RESULTS

From a total of 107 Salmonella isolates from samples collected in pig slaughterhouses and markets, 15 ESBL-producing Salmonella strains resistant to cefotaxime were identified by broth microdilution method and clavulanic acid inhibition test, including 14 monophasic Salmonella Typhimurium strains and one Salmonella Derby strain. Whole genome sequence analysis showed that nine monophasic S. Typhimurium strains coresistant to colistin and fosfomycin carried the resistance genes blaCTX-M-14, mcr-1, and fosA3. Conjugational transfer tests demonstrated that the phenotypic and genetic resistance to cephalosporins, colistin, and fosfomycin could cotransfer back and forth between Salmonella and Escherichia coli via an IncHI2/pSH16G4928-like plasmid.

CONCLUSIONS

This study reports the cotransmission of phenotypic and genetic resistance to cephalosporins, colistin, and fosfomycin via an IncHI2/pSH16G4928-like plasmid in Salmonella strains of animal origin, giving an alarm for the prevention of the development and spread of bacterial multidrug resistance.

Structural and Biochemical Features of OXA-517: a Carbapenem and Expanded-Spectrum Cephalosporin Hydrolyzing OXA-48 Variant

OXA-48-producing Enterobacterales have now widely disseminated throughout the world. Several variants have now been reported, differing by just a few amino-acid substitutions or deletions, mostly in the region of the loop β5-β6. As OXA-48 hydrolyzes carbapenems but lacks significant expanded-spectrum cephalosporin (ESC) hydrolytic activity, ESCs were suggested as a therapeutic option. Here, we have characterized OXA-517, a natural variant of OXA-48- with an Arg214Lys substitution and a deletion of Ile215 and Glu216 in the β5-β6 loop, capable of hydrolyzing at the same time ESC and carbapenems. MICs values of E. coli expressing bla_OXA-517 gene revealed reduced susceptibility to carbapenems (similarly to OXA-48) and resistance to ESCs. Steady-state kinetic parameters revealed high catalytic efficiencies for ESCs and carbapenems. The bla_OXA-517 gene was located on a ca. 31-kb plasmid identical to the prototypical IncL bla_OXA-48-carrying plasmid except for an IS1R-mediated deletion of 30.7-kb in the tra operon. The crystal structure of OXA-517, determined to 1.86 Å resolution, revealed an expanded active site compared to that of OXA-48, which allows for accommodation of the bulky ceftazidime substrate. Our work illustrates the remarkable propensity of OXA-48-like carbapenemases to evolve through mutation/deletion in the β5-β6 loop to extend its hydrolysis profile to encompass most β-lactam substrates.

Structural Analysis and Protein Binding of Cephalosporins

Cephalosporins are a widely used subclass of β-lactam antibiotics that demonstrate variable protein binding independent of generation or antibiotic coverage. Prior work analyzed carbon 3 (C3) and carbon 7 (C7) substituents (locations of R2 and R1 groups respectively) for protein binding interactions. This study builds upon these results with statistical analysis of additional agents of the class. Chemical structures of 23 cephalosporins were used to identify the presence of 40 functional groups, and correlative relationships were identified using established protein binding data. Four functional groups were significantly correlated with protein binding: tetrazole (positive association), pyridinium, primary amine, and quaternary amine (negative associations). Cephalosporins with a negative charge at physiological pH were associated with increased protein binding. Analysis of tetrazole-containing cephalosporins and ceftriaxone indicates the need for further study of the potential role in protein binding of neutral or negatively charged aromatic nitrogen heterocycles linked at the C3 position by a thiomethylene group.

Effect of Antimicrobial Exposure in Pregnancy on Adverse Pregnancy Outcomes and Admission Rate to the Neonatal Intensive Care Unit: A Multi-Center Cohort Study

Purpose

Antimicrobial agents are frequently prescribed during pregnancy. This study aims to explore the association between antimicrobial exposure and pregnancy outcomes.

Patients and Methods

A multi-center retrospective cohort study of pregnant patients (n=370) was conducted in 22 tertiary hospitals in China. Adverse pregnancy outcomes and admission of neonate to neonatal intensive care unit (NICU) were considered as outcomes. The effect of antimicrobial exposure on pregnancy outcomes was assessed using a multivariate logistic regression model.

Results

Use of first-generation cephalosporins during pregnancy was associated with a significantly higher risk of adverse pregnancy outcomes (odds ratio [OR]: 3.64 [95% confidence interval, CI: 1.43-9.24], P = 0.007) and admission of neonate to the NICU (OR: 3.41, 95% CI: 1.37-8.53, P=0.009) compared with use of third-generation cephalosporins, after adjusting for gestational age of exposure to antimicrobial agents, cesarean section, and antimicrobial dose. Similarly, a higher risk of adverse pregnancy outcomes (OR: 14.76, 95% CI: 4.43-49.11) and neonatal NICU admission (OR: 11.74, 95% CI: 3.59-38.35) were observed among women with first-generation cephalosporins use compared with mothers with no antimicrobial use.

Conclusion

Both first- and third-generation cephalosporins use was associated with an increased risk of adverse pregnancy and neonatal outcomes. In addition, first-generation cephalosporins were associated with an increased risk of those pregnant and neonatal outcomes, when compared with third-generation cephalosporins. We should require to determine the indications and contraindications for use of cephalosporins during pregnancy.

Cefepime-Induced Neutropenia: A Case Report and Literature Review

Cefepime is a fourth-generation cephalosporin utilized in treatment of multiple Gram-negative and -positive infections. The current report presents a case of 50-year-old man admitted with epidural abscess who developed neutropenia after prolonged use of cefepime. The neutropenia developed after 24 days of cefepime treatment and resolved 4 days after cessation of cefepime. Assessment of the patient's profile indicated no other possible cause for neutropenia. A literature review was done, and is presented herein to compare and identify the pattern of cefepime-induced neutropenia in 15 patients. The data presented in this article highlight that despite its rarity, cefepime-induced neutropenia should be considered by clinicians when planning a prolonged course of cefepime.

Characterization of cephalosporin and fluoroquinolone resistant Enterobacterales from Irish farm waste by whole genome sequencing

Background

The Enterobacterales are a group of Gram-negative bacteria frequently exhibiting extended antimicrobial resistance (AMR) and involved in the transmission of resistance genes to other bacterial species present in the same environment. Due to their impact on human health and the paucity of new antibiotics, the World Health Organization (WHO) categorized carbapenem resistant and ESBL-producing as critical. Enterobacterales are ubiquitous and the role of the environment in the transmission of AMR organisms or antimicrobial resistance genes (ARGs) must be examined in tackling AMR in both humans and animals under the one health approach. Animal manure is recognized as an important source of AMR bacteria entering the environment, in which resistant genes can accumulate.

Methods

To gain a better understanding of the dissemination of third generation cephalosporin and fluoroquinolone resistance genes between isolates in the environment, we applied whole genome sequencing (WGS) to Enterobacterales (79 E. coli, 1 Enterobacter cloacae, 1 Klebsiella pneumoniae, and 1 Citrobacter gillenii) isolated from farm effluents in Ireland before (n = 72) and after (n = 10) treatment by integrated constructed wetlands (ICWs). DNA was extracted using the MagNA Pure 96 system (Roche Diagnostics, Rotkreuz, Switzerland) followed by WGS on a MiSeq platform (Illumina, Eindhoven, Netherlands) using v3 chemistry as 300-cycle paired-end runs. AMR genes and point mutations were identified and compared to the phenotypic results for better understanding of the mechanisms of resistance and resistance transmission.

Results

A wide variety of cephalosporin and fluoroquinolone resistance genes (mobile genetic elements (MGEs) and chromosomal mutations) were identified among isolates that mostly explained the phenotypic AMR patterns. A total of 31 plasmid replicon types were identified among the 82 isolates, with a subset of them (n = 24), identified in E. coli isolates. Five plasmid replicons were confined to the Enterobacter cloacae isolate and two were confined to the Klebsiella pneumoniae isolate. Virulence genes associated with functions including stress, survival, regulation, iron uptake secretion systems, invasion, adherence and toxin production were identified.

Conclusion

Our study showed that antimicrobial resistant organisms (AROs) can persist even following wastewater treatment and could transmit AMR of clinical relevance to the environment and ultimately pose a risk to human or animal health.

Increasing Consumption of Antibiotics during the COVID-19 Pandemic: Implications for Patient Health and Emerging Anti-Microbial Resistance

The emergence of COVID-19 infection led to the indiscriminate use of antimicrobials without knowing their efficacy in treating the disease. The gratuitous use of antibiotics for COVID-19 treatment raises concerns about the emergence of antimicrobial resistance (AMR). In this systematic review, we performed a thorough systematic search using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines of scientific databases (Scopus, Web of Science, and PubMed) to identify studies where antibiotics were prescribed to treat COVID-19 (December 2019 to December 2021). Of 970 identified studies, 130 were included in our analyses. Almost 78% of COVID-19 patients have been prescribed an antibiotic. Cephalosporins were the most prescribed (30.1% of patients) antibiotics, followed by azithromycin (26% of patients). Antibiotics were prescribed for COVID-19 patients regardless of reported severity; the overall rate of antibiotic use was similar when comparing patients with a severe or critical illness (77.4%) and patients with mild or moderate illness (76.8%). Secondary infections were mentioned in only 11 studies. We conclude that concerns related to COVID-19 and the lack of treatment strategy led to the overuse of antibiotics without proper clinical rationale. Based on our findings, we propose that antimicrobial stewardship should be retained as a priority while treating viral pandemics.

Prevalence of Extended-Spectrum β-Lactamase-Resistant Genes in Escherichia coli Isolates from Central China during 2016-2019

The emergence and dissemination of Escherichia coli (E. coli) strains that produce extended-spectrum beta-lactamases (ESBLs) represents a major public health threat. The present study was designed to evaluate the prevalence and characteristics of ESBL-producing Escherichia coli isolates from chickens in central China during 2016-2019. A total of 407 E. coli strains isolated from 581 chicken swabs were identified conventionally and analyzed for various cephalosporin susceptibility by disk-diffusion assay. ESBL-producing strains were screened using the double=disk synergy test and ESBL-encoding genes were carried out by PCR/sequencing. A total of 402 E. coli isolates exhibited strong resistance to first- to fourth-generation cephalosporins and monobactam antibiotics, especially cefazolin (60.69%), cefuroxime (54.05%), cefepime (35.14%), ceftriaxone (54.30%), and aztreonam (40.29%). Piperacillin/tazobactam (1.72%) was the most effective drug against the strains, but the resistance rates increased each year. Among the isolates, 262 were identified as ESBL producers and the isolation rates for the ESBL producers increased from 63.37% to 67.35% over the four years. CTX-M (97.33%) was the most prevalent type, followed by TEM (76.72%) and SHV (3.05%). The most common ESBL genotype combination was bla_TEM + bla_CTX-M (74.46%), in which the frequency of carriers increased steadily, followed by bla_CTX-M + bla_SHV (3.05%). In addition, the most predominant specific CTX-M subtypes were CTX-M-55 (48.47%) and CTX-M-1 (17.94%), followed by CTX-M-14 (11.01%), CTX-M-15 (8.02%), CTX-M-9 (6.11%), CTX-M-65 (4.58%), and CTX-M-3 (1.15%). Moreover, a novel multiplex qPCR assay was developed to detect bla_CTX-M, bla_TEM, and bla_SHV, with limits of detection of 2.06 × 10¹ copies/μL, 1.10 × 10¹ copies/μL, and 1.86 × 10¹ copies/μL, respectively, and no cross-reactivity with other ESBL genes and avian pathogens. The assays exhibited 100% sensitivity and specificities of 85%, 100%, and 100% for bla_CTX-M, bla_TEM, and bla_SHV, respectively. In conclusion, our findings indicated that ESBL-producing E.coli strains isolated from chickens in central China were highly resistant to cephalosporins and frequently harbored diversity in ESBL-encoding genes. These isolates can pose a significant public health risk. The novel multiplex qPCR method developed in this study may be a useful tool for molecular epidemiology and surveillance studies of ESBL genes.

Synthesis and Antimicrobial Evaluation of New Cephalosporin Derivatives Containing Cyclic Disulfide Moieties

Due to a steady increase in microbial resistance, there is a need to increase the effectiveness of antibiotic performance by involving additional mechanisms of their penetration or retention for their better action. Cephalosporins are a successful group of antibiotics to combat pathogenic microorganisms, including drug-resistant strains. In this study, we investigated the effect of newly synthesized cephalosporin derivatives with cyclic disulfide modifications against several Gram-positive and Gram-negative strains as well as against biofilm formation. The incorporation of asparagusic acid was found to be effective in improving the activity of the drug against Gram-negative strains compared to the all carbon-control compounds. Furthermore, we could demonstrate the successful reduction of biofilm formation for Staphylococcus aureus and Pseudomonas aeruginosa at similar concentrations as obtained against planktonic cells. We propose that the incorporation of cyclic disulfides is one additional strategy to improve antibiotic activity and to combat bacterial infections.

Occurrence and potential transmission of extended-spectrum beta-lactamase-producing extraintestinal pathogenic and enteropathogenic Escherichia coli in domestic dog faeces from Minnesota

Interactions between humans and pets are increasingly valued in western countries, leading to more extensive contact between humans and their pets within households. Although the magnitude of the risk of transfer of Escherichia coli between humans and their companion animals is undefined, that such transmission occurs has been established and warrants attention. This study examined 186 fresh faecal samples from companion dogs visiting 22 municipal dog parks in the Minneapolis/Saint Paul metropolitan area, Minnesota, USA. Samples were processed to isolate 3rd-generation cephalosporin-resistant E. coli, which were further characterized using PCR-based virulence genotyping, antimicrobial susceptibility profiling and whole-genome sequencing. Of the 186 faecal samples, 29% yielded cephalosporin-resistant E. coli, and 2.2% yielded extended-spectrum beta-lactamase producers. Co-resistance to sulfonamides was typical (77.3% of isolates), and multidrug resistance (i.e. to ≥3 antimicrobial classes), including to combinations of tetracyclines, phenicols, quinolones and aminoglycosides, was substantial (18.9% of isolates). Identified beta-lactamase genes included bla_CMY-2 , bla_TEM-1B , bla_TEM-1 , bla_CTX-M-24 , bla_CTX-M-15 and bla_OXA-1 . Genome sequencing of 14 isolates identified genes typical of extraintestinal pathogenic E. coli or enteropathogenic E. coli. In three instances, closely related isolates were recovered from different dogs, within either the same park-suggesting transfer of E. coli between dogs within the park-or different parks-suggesting that dogs may be pre-disposed to carry certain E. coli types, such as those from serogroups O4, O71 and O157. This study adds to the existing evidence that companion dogs can harbour and share antimicrobial-resistant E. coli with presumed intestinal or extraintestinal pathogenic potential.

Effect of Reduced Fluoroquinolone Use on Cephalosporin Use, Susceptibilities and Clostridioides difficile Infections

Background: Overuse of fluoroquinolones has led to concerning rates of resistance, particularly among Gram-negative organisms. They are also highly implicated as a risk factor for Clostridioides difficile infection, and reports of other serious adverse events led to recommendations to restrict their use. Our health system began targeting the reduction in unnecessary fluoroquinolone prescribing in 2018, aiming to promote their safe and effective use. Broad-spectrum cephalosporins are often used as an alternative to fluoroquinolones. We sought to evaluate whether decreased fluoroquinolone use was associated with increased third- and fourth-generation cephalosporin use and whether these changes in utilization impacted other outcomes, including C. difficile infection (CDI) rates and susceptibilities among Gram-negative organisms. Methods: This retrospective descriptive analysis included adult patients who received a fluoroquinolone or broad-spectrum cephalosporin in a three-year time period across a large healthcare system. The primary objective was to evaluate the change in days of therapy (DOT) of fluoroquinolones and third- and fourth-generation cephalosporins. Secondary objectives included rates of resistance among common Gram-negative organisms, CDI, and analyses stratified by antibiotic indication. Results: Cephalosporin use increased by an average of 1.70 DOT/1000 PD per month (p < 0.001). Additionally, fluoroquinolone use decreased by an average of 1.18 DOT/1000 PD per month (p < 0.001). C. difficile infections decreased by 0.37 infections/10,000 patient-days per month (p < 0.001). Resistance to fluoroquinolones remained stable from 2018 to 2020, and a declining trend was observed in 2021. Conclusion: This study demonstrated that reduced fluoroquinolone use in a large healthcare system was associated with increased usage of broad-spectrum cephalosporins, decreased CDI and improvements in resistance patterns.

Cephem-Pyrazinoic Acid Conjugates: Circumventing Resistance in Mycobacterium tuberculosis

Tuberculosis (TB) is a leading source of infectious disease mortality globally. Antibiotic-resistant strains comprise an estimated 10 % of new TB cases and present an urgent need for novel therapeutics. β-lactam antibiotics have traditionally been ineffective against M. tuberculosis (Mtb), the causative agent of TB, due to the organism's inherent expression of β-lactamases that destroy the electrophilic β-lactam warhead. We have developed novel β-lactam conjugates, which exploit this inherent β-lactamase activity to achieve selective release of pyrazinoic acid (POA), the active form of a first-line TB drug. These conjugates are selectively active against M. tuberculosis and related mycobacteria, and activity is retained or even potentiated in multiple resistant strains and models. Preliminary mechanistic investigations suggest that both the POA "warhead" as well as the β-lactam "promoiety" contribute to the observed activity, demonstrating a codrug strategy with important implications for future TB therapy.

In Vitro Activity of Cefiderocol against Extensively Drug-Resistant Pseudomonas aeruginosa: CANWARD, 2007 to 2019

Cefiderocol was evaluated by broth microdilution versus 1,050 highly antimicrobial-resistant Pseudomonas aeruginosa clinical isolates from the CANWARD study (2007 to 2019). Overall, 98.3% of isolates remained cefiderocol susceptible (MIC, ≤4 μg/mL), including 97.4% of extensively drug-resistant (XDR) (n = 235) and 97.9% of multidrug-resistant (MDR) (n = 771) isolates. Most isolates testing not susceptible to ceftolozane-tazobactam, ceftazidime-avibactam, and imipenem-relebactam remained susceptible to cefiderocol. In vitro data suggest that cefiderocol may be a treatment option for infections caused by MDR and XDR P. aeruginosa. IMPORTANCE After testing cefiderocol against a large collection of clinical isolates of highly antimicrobial-resistant Pseudomonas aeruginosa, we report that cefiderocol is active versus 97.4% of extensively drug-resistant (XDR) and 97.9% of multidrug-resistant (MDR) (n = 771) isolates. These data show that cefiderocol may be a treatment option for infections caused by MDR and XDR P. aeruginosa.

Antimicrobial Activity of Ceftaroline and Comparator Agents Against Ceftriaxone-Nonsusceptible Streptococcus pneumoniae from the United States (2008-2020)

We evaluated the activity of ceftaroline against clinical isolates of ceftriaxone-nonsusceptible Streptococcus pneumoniae from United States medical centers. Streptococcus pneumoniae isolates (n = 21,750) were consecutively collected from 201 medical centers in 2008-2020 and tested for susceptibility by broth microdilution method. Among these isolates, 1,419 (6.5%) were ceftriaxone-nonsusceptible (ceftriaxone minimum inhibitory concentration [MIC], ≥2 mg/L). Other resistant subgroups analyzed included multidrug-resistant (MDR; nonsusceptibility to ≥3 classes of agents; n = 4,454) and extensively drug-resistant (XDR; nonsusceptibility to ≥5 classes; n = 1,708) isolates. Ceftriaxone susceptibility increased from 89.0% (2008-2011) to 98.1% (2018-2020). Ceftaroline was active against 99.9% of ceftriaxone-nonsusceptible isolates (MIC_50/90, 0.25/0.25 mg/L) and retained potent activity against MDR (n = 4,454; MIC_50/90, 0.12/0.25 mg/L; >99.9% susceptible) and XDR (n = 1,708; MIC_50/90, 0.25/0.25 mg/L; 100.0% susceptible) isolates. Only one isolate had a ceftaroline MIC ≥0.5 mg/L. In summary, ceftaroline demonstrated potent and consistent activity over time (2008-2020) against a large collection of S. pneumoniae from U.S. medical centers, including ceftriaxone-nonsusceptible, MDR, and XDR isolates.

Cefonicid Benzathine Salt: A Convenient, Lean, and High-Performance Protocol to Make an Old Cephalosporin Shine

Cefonicid is a second-generation cephalosporin sold under the brand name Sintocef™. It is an injectable drug obtained via a freeze-drying process and is also available for oral preparations. The high-quality standard required is very challenging to satisfy, and current production protocols are characterized by steps that are lengthy and cumbersome, making the product unattractive for the international market. Industrial R&D is constantly working on the process optimization for API synthesis, with the aim of increasing productivity and decreasing production costs and waste. We herein report a new and efficient method for the synthesis of the cefonicid benzathine salt that provides a good yield and high product stability. The double-nucleophilic and lipophilic nature of N',N″-dibenzylethylene diacetate enables the deformylation of the OH-protected group on the mandelic moiety and also enables product crystallization to occur. We demonstrate that the formyl group in the peculiar position has high reactivity, promoting an amidation reaction that deprotects a hydroxy group and generates a new C-N bond in the reaction by-product. Several amines and OH-protected groups have been studied, but none were able to replicate the excellent results of benzathine diacetate.

Treatment of carbapenem-resistant Pseudomonas aeruginosa infections: a case for cefiderocol

INTRODUCTION

Carbapenem-resistant (CR) Pseudomonas aeruginosa infections constitute a serious clinical threat globally. Patients are often critically ill and/or immunocompromised. Antibiotic options are limited and are currently centered on beta-lactam-beta-lactamase inhibitor (BL-BLI) combinations and the siderophore cephalosporin cefiderocol.

AREAS COVERED

This article reviews the mechanisms of P. aeruginosa resistance and their potential impact on the activity of current treatment options, along with evidence for the clinical efficacy of BL-BLI combinations in P. aeruginosa infections, some of which specifically target infections due to CR organisms. The preclinical and clinical evidence supporting cefiderocol as a treatment option for P. aeruginosa involving infections is also reviewed.

EXPERT OPINION

Cefiderocol is active against most known P. aeruginosa mechanisms mediating carbapenem resistance. It is stable against different serine- and metallo-beta-lactamases, and, due to its iron channel-dependent uptake mechanism, is not impacted by porin channel loss. Furthermore, the periplasmic level of cefiderocol is not affected by upregulated efflux pumps. The potential for on-treatment resistance development currently appears to be low, although more clinical data are required. Information from surveillance programs, real-world compassionate use, and clinical studies demonstrate that cefiderocol is an important treatment option for CR P. aeruginosa infections.

Outpatient penicillin allergy evaluation during pregnancy and associated clinical outcomes

BACKGROUND

Beta-lactam antibiotics are often clinically indicated in the peripartum period, posing a challenge for pregnant women who report a penicillin allergy. Allergy verification testing is rarely performed during pregnancy even though most women do not have a true allergy.

OBJECTIVE

To evaluate a hospital-wide multidisciplinary program introduced in August 2020 to identify, refer, evaluate, and test pregnant women with unverified penicillin allergies, and assess its association with maternal and neonatal outcomes.

STUDY DESIGN

We conducted a retrospective cohort study at a large academic hospital of all pregnant women with a penicillin allergy documented in the electronic medical record who delivered from September 2020 to October 2021. Data were abstracted by chart review. Women referred for penicillin allergy evaluation were compared to those who were not. Maternal outcomes were alternative antibiotic (clindamycin or vancomycin) use, postpartum infection, and maternal length of postpartum hospital stay. Neonatal outcomes were intensive care unit admission, postnatal blood draw, antibiotic treatment, and birth hospitalization length of hospital stay. Bivariate and multivariable analyses were performed.

RESULTS

Of 689 women with a documented penicillin allergy, 232 (33.7%) were referred for allergy evaluation during the study period. Of those referred, 175 (75.4%) underwent allergy consultation and 167 (95.4%) of them were considered appropriate for allergy verification testing. 117 (70.1%) underwent skin testing with or without graded oral amoxicillin drug challenge, and all but one (99.1%) were found to be penicillin tolerant. Five additional women were de-labeled of their penicillin allergy based on history and pharmacy confirmation of penicillin tolerance subsequent to index reaction. Referred women had a 62% lower likelihood of receiving an alternative antibiotic than those who were not referred, and this significance persisted even after adjusting for potential confounders (aOR 0.49, 95% CI 0.27-0.89). Other maternal and neonatal adverse outcomes were less frequent in those referred, but these associations did not reach statistical significance.

CONCLUSION

This study documents the feasibility, safety, and clinical benefit of an outpatient penicillin allergy referral program for pregnant women. Referred patients were significantly less likely to receive alternative antibiotics, however, more patients are needed to assess whether there are additional clinical benefits.

Global Distribution of Extended Spectrum Cephalosporin and Carbapenem Resistance and Associated Resistance Markers in Escherichia coli of Swine Origin - A Systematic Review and Meta-Analysis

Third generation cephalosporins and carbapenems are considered critically important antimicrobials in human medicine. Food animals such as swine can act as reservoirs of antimicrobial resistance (AMR) genes/bacteria resistant to these antimicrobial classes, and potential dissemination of AMR genes or resistant bacteria from pigs to humans is an ongoing public health threat. The objectives of this systematic review and meta-analysis were to: (1) estimate global proportion and animal-level prevalence of swine E. coli phenotypically resistant to third generation cephalosporins (3GCs) and carbapenems at a country level; and (2) measure abundances and global distribution of the genetic mechanisms that confer resistance to these antimicrobial classes in these E. coli isolates. Articles from four databases (CAB Abstracts, PubMed/MEDLINE, PubAg, and Web of Science) were screened to extract relevant data. Overall, proportion of E. coli resistant to 3GCs was lower in Australia, Europe, and North America compared to Asian countries. Globally, <5% of all E. coli were carbapenem-resistant. Fecal carriage rates (animal-level prevalence) were consistently manifold higher as compared to pooled proportion of resistance in E. coli isolates. bla_CTX–M were the most common 3GC resistance genes globally, with the exception of North America where bla_CMY were the predominant 3GC resistance genes. There was not a single dominant bla_CTX–M gene subtype globally and several bla_CTX–M subtypes were dominant depending on the continent. A wide variety of carbapenem-resistance genes (bla_{NDM–, VIM–, IMP–, OXA–48}, _andKPC–) were identified to be circulating in pig populations globally, albeit at very-low frequencies. However, great statistical heterogeneity and a critical lack of metadata hinders the true estimation of prevalence of phenotypic and genotypic resistance to these antimicrobials. Comparatively frequent occurrence of 3GC resistance and emergence of carbapenem resistance in certain countries underline the urgent need for improved AMR surveillance in swine production systems in these countries.

Ceftazidime pharmacokinetics in dogs after intravenous injection and delivered with the RxActuator Mini-Infuser infusion pump

OBJECTIVE

To test the feasibility of an SC mini-infusion pump to deliver ceftazidime in dogs and produce plasma concentrations sufficient to reach a therapeutic target for 48 hours.

SETTING

University research laboratory.

ANIMALS

Six healthy Beagle dogs.

INTERVENTIONS

Ceftazidime was administered by 2 routes to 6 healthy Beagle dogs. The first route was an IV bolus injection into a cephalic vein at a dose of 25 mg/kg. Blood samples were collected for 8 hours following injection. The second route was a SC infusion for 48 hours using the RxActuator Mini-Infuser wearable SC constant rate infusion pump. Blood samples were collected for 58 hours following application of the pump. All plasma samples were analyzed by high-pressure liquid chromatography and subject to pharmacokinetic analysis.

MAIN RESULTS

After the IV bolus injection, there was rapid distribution and elimination. The elimination half-life was 0.95 hours, and the clearance was rapid at 0.176 ml/h/kg. After the 48-hour SC infusion, the half-life was slightly shorter, and the clearance was higher. The percent bioavailability from the SC infusion was approximately 72%. The SC infusion maintained plasma concentration near our target of 8 μg/ml for most of the dose interval but slightly lower after 24 hours. The concentrations below the target were attributed to slight drug loss, less than 100% bioavailability, and faster clearance from SC administration.

CONCLUSIONS

This study demonstrated the successful application of the RxActuator Mini-Infuser wearable SC constant rate infusion pump for delivering an antimicrobial needed for serious, and sometimes resistant, infections in dogs.

A Rare Pediatric Case of Cefixime Induced Toxic Epidermal Necrolysis

Cefixime is a third-generation cephalosporin that has been used for the treatment of a wide range of infections in children and adults. The incidence of cefixime induced toxic epidermal necrolysis (TEN) is less than 2% in adults, but it is infrequent among pediatric patients. We report a rare case of cefixime induced TEN in a 7-year-old boy. In this case, the child presented with symptoms of TEN after 2 days of administration of cefixime. This case highlights the need to select structurally different antibiotics in case of antibiotic-induced severe cutaneous adverse reaction (SCAR) to avoid recurrence of SCAR. Furthermore, concluded that irrational use of antibiotics could be disastrous as it can result in TEN as the incidence of antibiotics induced TEN ranges from 29% to 42%.

Cefotaxime Mediated Synthesis of Gold Nanoparticles: Characterization and Antibacterial Activity

Cefotaxime (CTX) is a third-generation cephalosporin antibiotic with broad-spectrum activity against Gram negative and Gram positive bacteria. However, like other third-generation cephalosporin antibiotics, its efficacy is declining due to the increased prevalence of multidrug-resistant (MDR) pathogens. Recent advances in nanotechnology have been projected as a practical approach to combat MDR microorganisms. Therefore, in the current study, gold nanoparticles (AuNPs) were prepared using cefotaxime sodium, which acted as a reducing and capping agent, besides having well-established antibacterial activity. The synthesized cefotaxime-loaded gold nanoparticles (C-AuNPs) were characterized by UV-Visible spectroscopy, FTIR, TEM and DLS. In addition, the in vitro antibacterial activity of C-AuNPs was assessed against both Gram-positive and Gram-negative bacteria. UV-Visible spectroscopy verified the formation of C-AuNPs, while TEM and DLS verified their nano-size. In addition, CTX loading onto AuNPs was confirmed by FTIR. Furthermore, the colloidal stability of the synthesized C-AuNPs was ascribed to the higher net negative surface charge of C-AuNPs. Most importantly, the synthesized C-AuNPs showed superior antibacterial activity and lower minimum inhibitory concentration (MIC) values against Gram-negative (Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria, compared with pure CTX. Collectively, CTX was successfully adopted, as reducing and capping agent, to synthesize stable, nano-sized spherical C-AuNPs. Furthermore, loading CTX onto AuNPs could efficiently restore and/or boost the antibacterial activity of CTX against resistant Gram-negative and Gram-positive bacteria.

Cefiderocol: A new Antimicrobial for Complicated Urinary Tract Infection (CUTI) Caused by Carbapenem-resistant Enterobacteriaceae (CRE)

The incidence of carbapenem-resistant gram-negative (CRGNB) bacterial infections has increased globally. The wide diversity of strains, multiplicity of infections, and rapid development and spread of resistance are a matter of great concern both in community and hospital settings. Cefiderocol is a novel injectable siderophore containing cephalosporin with potent microbicidal activity against most carbapenem-resistant Enterobacteriaceae (CRE). It has recently been approved by USFDA for the treatment of complicated urinary tract infections (cUTI) caused by susceptible gram-negative microorganisms. This review focuses on the salient pharmacological profile of the drug and the clinical studies that were undertaken. Cefiderocol is first in class injectable siderophore cephalosporin showing potency against carbapenem- resistant Enterobacteriaceae. It has recently been approved by US FDA for the treatment of adult patients with complicated urinary tract infections (cUTI) caused by susceptible Gram-negative microorganisms, where there are limited or no alternative treatment options.

Photocatalytic Degradation of Cefixime Trihydrate by Bismuth Ferrite Nanoparticles

The present work was carried out to synthesize bismuth ferrite (BFO) nanoparticles by combustion synthesis, and to evaluate the photocatalytic activity of synthesized bismuth ferrite nanoparticles against cefixime trihydrate. BFO nanoparticles were successfully synthesized using bismuth (III) nitrate and iron (III) nitrate by a combustion synthesis method employing different types of fuels such as maltose, succinic acid, cinnamic acid, and lactose. The effects of the different types of fuels on the morphology and size of the bismuth ferrite nanoparticles were investigated. Characterization of the as-obtained bismuth ferrite nanoparticles was carried out by different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy-Dispersive Spectroscopy (EDS), N₂-sorption analysis, Fourier-transform infrared spectroscopy (FT-IR), and ultraviolet-visible (UV-vis) spectroscopy. Photoluminescence studies were also carried out for the various bismuth ferrite nanoparticles obtained. Degradation of cefixime trihydrate was investigated under sunlight to evaluate the photocatalytic properties of the bismuth ferrite nanoparticles, and it was found that the bismuth ferrite nanoparticles followed first-order degradation kinetics in solar irradiation in the degradation of antibiotic, cefixime trihydrate.

β-lactam Resistance in Pseudomonas aeruginosa: Current Status, Future Prospects

Pseudomonas aeruginosa is a major opportunistic pathogen, causing a wide range of acute and chronic infections. β-lactam antibiotics including penicillins, carbapenems, monobactams, and cephalosporins play a key role in the treatment of P. aeruginosa infections. However, a significant number of isolates of these bacteria are resistant to β-lactams, complicating treatment of infections and leading to worse outcomes for patients. In this review, we summarize studies demonstrating the health and economic impacts associated with β-lactam-resistant P. aeruginosa. We then describe how β-lactams bind to and inhibit P. aeruginosa penicillin-binding proteins that are required for synthesis and remodelling of peptidoglycan. Resistance to β-lactams is multifactorial and can involve changes to a key target protein, penicillin-binding protein 3, that is essential for cell division; reduced uptake or increased efflux of β-lactams; degradation of β-lactam antibiotics by increased expression or altered substrate specificity of an AmpC β-lactamase, or by the acquisition of β-lactamases through horizontal gene transfer; and changes to biofilm formation and metabolism. The current understanding of these mechanisms is discussed. Lastly, important knowledge gaps are identified, and possible strategies for enhancing the effectiveness of β-lactam antibiotics in treating P. aeruginosa infections are considered.

A Genome-Scale Antibiotic Screen in Serratia marcescens Identifies YdgH as a Conserved Modifier of Cephalosporin and Detergent Susceptibility

Serratia marcescens, a member of the order Enterobacterales, is adept at colonizing health care environments and is an important cause of invasive infections. Antibiotic resistance is a daunting problem in S. marcescens because, in addition to plasmid-mediated mechanisms, most isolates have considerable intrinsic resistance to multiple antibiotic classes. To discover endogenous modifiers of antibiotic susceptibility in S. marcescens, a high-density transposon insertion library was subjected to sub-MICs of two cephalosporins, cefoxitin, and cefepime, as well as the fluoroquinolone ciprofloxacin. Comparisons of transposon insertion abundance before and after antibiotic exposure identified hundreds of potential modifiers of susceptibility to these agents. Using single-gene deletions, we validated several candidate modifiers of cefoxitin susceptibility and chose ydgH, a gene of unknown function, for further characterization. In addition to cefoxitin, deletion of ydgH in S. marcescens resulted in decreased susceptibility to multiple third-generation cephalosporins and, in contrast, to increased susceptibility to both cationic and anionic detergents. YdgH is highly conserved throughout the Enterobacterales, and we observed similar phenotypes in Escherichia coli O157:H7 and Enterobacter cloacae mutants. YdgH is predicted to localize to the periplasm, and we speculate that it may be involved there in cell envelope homeostasis. Collectively, our findings provide insight into chromosomal mediators of antibiotic resistance in S. marcescens and will serve as a resource for further investigations of this important pathogen.

Effect of an Intensified Antibiotic Stewardship Program at an Orthopedic Surgery Department

Background: Institutional programs such as antibiotic stewardship (ABS) programs offer possibilities to monitor and modify antibiotic usage with the aim of reducing antibiotic resistance. In orthopedic units that treat peri-prosthetic joint infections (PJIs), ABS programs are still rare, however, there is extensive use of high-risk antibiotic agents and an increased risk for the occurrence of Clostridium difficile infections (CDIs). Patients and Methods: An ABS program was implemented at the Department of Orthopedic Surgery at a university hospital. Quarterly antibiotic consumption was measured in defined daily doses (DDDs) per 100 patient-days (PDs) at 10 quarters before the intervention and seven quarters after the intervention. The effect of the new antibiotic policy on drug use rates was evaluated using an interrupted time-series analysis. Estimated changes over time in the incidence of CDIs (cases per 1,000 PDs) were analyzed. Results: A remarkable percentual reduction in second-generation cephalosporin use of 83% (p < 0.001; pre-intervention level, 81.486 DDDs/100 patient-days; post-intervention level, 13.751 DDDs/100 PDs) and clindamycin administration of 78% (p < 0.001; pre-intervention level, 18.982 DDDs/100 PDs; post-intervention level, 4.216 DDDs/100 PDs) was observed after implementation of ABS interventions. Total antibiotic use declined by 25% (p < 0.001; pre-intervention level, 129.078 DDDs/100 PDs; post-intervention level, 96.826 DDDs/100 PDs). Conclusions: This research assessed the positive impact of an intensified ABS program at an orthopedic department specializing in PJIs. Antibiotic stewardship program interventions encourage the reduction of total antibiotic usage and especially high-risk antibiotic agents, associated with the development of antimicrobial resistance.

Repurposing Cefazolin-Avibactam for the Treatment of Drug Resistant Mycobacterium tuberculosis

Background: While tuberculosis (TB) is curable and preventable, the most effective first-line antibiotics cannot kill multi-drug resistant (MDR) Mycobacterium tuberculosis (Mtb). Therefore, effective drugs are needed to combat MDR-TB, especially in children. Our objective was to repurpose cefazolin for MDR-TB treatment in children using principles of pharmacokinetic/pharmacodynamics (PK/PD).

Methods: Cefazolin minimum inhibitory concentration (MIC) was identified in 17 clinical Mtb strains, with and without combination of the β-lactamase inhibitor, avibactam. Next, dose-ranging studies were performed using the intracellular hollow fiber model of TB (HFS-TB) to identify the optimal cefazolin exposure. Monte Carlo experiments were then performed in 10,000 children for optimal dose identification based on cumulative fraction of response (CFR) and Mtb susceptibility breakpoint in three age-groups.

Results: Avibactam reduced the cefazolin MICs by five tube dilutions. Cefazolin-avibactam demonstrated maximal kill of 4.85 log₁₀ CFU/mL in the intracellular HFS-TB over 28 days. The % time above MIC associated with maximal effect (EC₈₀) was 46.76% (95% confidence interval: 43.04–50.49%) of dosing interval. For 100 mg/kg once or twice daily, the CFR was 8.46 and 61.39% in children <3 years with disseminated TB, 9.70 and 84.07% for 3–5 years-old children, and 17.20 and 76.13% for 12–15 years-old children. The PK/PD-derived susceptibility breakpoint was dose dependent at 1–2 mg/L.

Conclusion: Cefazolin-avibactam combination demonstrates efficacy against both drug susceptible and MDR-TB clinical strains in the HFS-TB and could potentially be used to treat children with tuberculosis. Clinical studies are warranted to validate our findings.

Pharmacokinetics and Safety of Ceftobiprole in Pediatric Patients

BACKGROUND

Ceftobiprole, the active moiety of the prodrug ceftobiprole medocaril, is an advanced-generation, broad-spectrum, intravenous cephalosporin, which is currently approved for the treatment of adults with hospital-acquired or community-acquired pneumonia.

METHODS

Noncompartmental pharmacokinetics and safety were analyzed from 2 recently completed pediatric studies, a single-dose, phase 1 study in neonates and infants up to 3 months of age (7.5 mg/kg) and a phase 3 study in patients 3 months to 17 years of age with pneumonia (10-20 mg/kg with a maximum of 500 mg per dose every 8 hours for up to 14 days).

RESULTS

Total ceftobiprole plasma concentrations peaked at the end of infusion. Half life (median ranging from 1.9 to 2.9 hours) and overall exposure (median AUC ranging from 66.6 to 173 μg•h/mL) were similar to those in adults (mean ± SD, 3.3 ± 0.3 hours and 102 ± 11.9 μg•h/mL, respectively). Calculated free-ceftobiprole concentrations in the single-dose study remained above a minimum inhibitory concentration (MIC) of 4 mg/L (fT > MIC of 4 mg/L) for a mean of 5.29 hours after dosing. In the pneumonia study, mean fT > MIC of 4 mg/L was ≥5.28 hours in all dose groups. Ceftobiprole was well tolerated in both studies.

CONCLUSIONS

Pharmacokinetic parameters of ceftobiprole characterized in the pediatric population were within the range of those observed in adults. In the pneumonia study, the lowest percentage of the dosing interval with fT > MIC of 4 mg/L was 50.8%, which suggests that pharmacokinetic-pharmacodynamic target attainment can be sufficient in pediatric patients. Ceftobiprole was well tolerated.

Simple and accurate quantitative analysis of cefiderocol and ceftobiprole in human plasma using liquid chromatography-isotope dilution tandem mass spectrometry: interest for their therapeutic drug monitoring and pharmacokinetic studies

OBJECTIVES

Cefiderocol and ceftobiprole are new generation cephalosporin antibiotics that exhibit high inter-individual plasma concentration variability that potentially impact their efficacy or toxicity. The aim of this study was to develop and validate a selective, simple, and fast UPLC-MS/MS method for simultaneous quantification of cefiderocol and ceftobiprole in human plasma to enable their therapeutic drug monitoring (TDM) and support PK and PK/PD studies, in particular in critically ill patients.

METHODS

After a simple and fast single-step protein precipitation, cefiderocol and ceftobiprole were separated on a Waters Acquity UPLC BEH C18 column by linear gradient elution; with subsequent detection by Shimadzu MS 8060 triple quadrupole tandem mass spectrometer in a positive ionization mode.

RESULTS

Analysis time was 5 min per run. The analytical performance of the method in terms of specificity, sensitivity, linearity, precision, accuracy, matrix effect (ME), extraction recovery (ER), limit of quantification, dilution integrity, and stability of analytes under different conditions met all criteria for a bioanalytical method for the quantification of drugs. The calibration curves were linear over the range of 1-200 mg/L for cefiderocol and 0.5-100 mg/L for ceftobiprole with a linear regression coefficient above 0.995 for both.

CONCLUSIONS

A simple, fast, and selective liquid chroma-tography-tandem mass spectrometry method was developed and validated for the simultaneous quantification of cefiderocol and ceftobiprole. This new method was successfully applied to the measurement of plasma concentration of cefiderocol and ceftobiprole in critically ill patients and showed good performance for their therapeutic monitoring and optimizing antibiotic therapy.

Pharmacokinetics of a Single Intramuscular Injection of Ceftiofur Crystalline Free Acid in Bald Eagles (Haliaeetus leucocephalus)

The objective of this study was to evaluate the pharmacokinetic properties of ceftiofur crystalline free acid (CCFA) administered intramuscularly at dosages of 10 and 20 mg/kg in bald eagles (BAEAs) (Haliaeetus leucocephalus). Ceftiofur crystalline free acid is a long-acting, injectable, third-generation cephalosporin antibiotic drug. A prospective, randomized, complete crossover design was used for this pharmacokinetic investigation. CCFA (10 or 20 mg/kg) was administered intramuscularly, and blood samples were obtained from 6 adult, nonreleasable, healthy BAEAs at predetermined sampling times. After a 4-week washout period, the protocol was repeated with each bird receiving the dose not given during the initial sample collection according to the randomized crossover design. Plasma ceftiofur free acid equivalents were quantified and data were analyzed by a noncompartmental pharmacokinetic approach. The mean observed peak plasma concentrations were 9.23 µg/mL and 15.08 µg/mL for 10 and 20 mg/kg CCFA IM administration, respectively. The mean observed time to maximum plasma concentration was 18 and 17.6 hours, and the mean terminal elimination half-life was 32.38 and 38.08 hours for intramuscular administration of 10 and 20 mg/kg CCFA, respectively, in the BAEAs. Reported minimum inhibitory concentrations of raptor bacterial isolates from a prior study was used to determine the target minimum inhibitory concentration of 1 µg/mL selected for this investigation. From the previously published information, a target plasma concentration of 4 µg/mL was determined for the CCFA in the BAEAs. From the results of this study, CCFA may be dosed every 60 and 110 hours at 10 mg/kg IM, and every 80 and 160 hours at 20 mg/kg IM in BAEAs.

Status and Safety Signals of Cephalosporins in Children: A Spontaneous Reporting Database Study

Introduction: Cephalosporins are widely used in clinical treatment of children, but it is difficult to carry out clinical trials and there is no strong evidence of their safety. Therefore, adverse drug reactions (ADR) of cephalosporins can be a public health problem that deserves attention. Methods: ADR reports collected by the Hubei Adverse Drug Reaction Monitoring Center from 2014 to 2019 were analysed. The safety of Cephalosporins was described by descriptive analysis and three signal mining methods, including the reporting odd ratio (ROR), proportional reporting ratio (PRR), and comprehensive standard method (MHRA). Results: The findings indicated that the age groups of 0-1 and 2-3 years had the highest rates of reporting ADRs. Children aged 0-4 years reported more ADRs, while the proportion of severe ADRs was lower than the average (6.63%). Among the 37 cephalosporins, the severe ADRs of ceftezole, ceftazidime, cefoperazone/sulbactam, cefotaxime, ceftriaxone were reported more and the proportion of severe ADRs was higher. The proportion of severe ADRs of most cephalosporin compound preparations was higher than that of corresponding single components. A total of 99.18% of the cases improved after treatment. There were four deaths whose ADRs were mainly anaphylactic shock, dyspnoea, and anaphylactoid reaction. In signal mining, the three methods produced 206 signals that were the same, and 73 of them were off-label ADRs. Conclusion: ADRs were common but not serious in children aged 0-4 years. And the reported rate of serious ADRs in children aged over 4 years increased with age. ADR reports of ceftezole, ceftazidime, cefoperazone/sulbactam, cefotaxime, ceftriaxone were numerous and serious, and the safety of cephalosporin compound preparations in children was doubtful. Ceftezole may cause off-label ADRs including tremor, face oedema, cyanosis, pallor, rigors, and palpitation. The labeling of ADRs in children in cephalosporin instructions and the record of allergic history need to be improved.

Impact of a training session for prescribers on the relative prescription of cefotaxime over ceftriaxone in elderly patients

BACKGROUND

The prescription of ceftriaxone should be limited to patients with biliary tract infections and those lacking intravenous access. A specific training session for prescribers about the clinical relevance and economic value of prescribing cefotaxime instead of ceftriaxone might decrease the use of the latter in geriatric medicine.

OBJECTIVES

To determine the clinical and economic impact of a training session for prescribers on the subsequent prescription of third-generation cephalosporin, that is, the percentage of appropriate prescriptions and the cost of third-generation cephalosporin administration before and after the training session.

METHODS

In a preliminary observational quasi-experimental, open-label study, appropriateness of cefotaxime and ceftriaxone prescription over a 4-week period immediately before the training session were compared with those during a 4-week period immediately afterwards.

KEY FINDINGS

For 46 patients (29 before the training session and 17 afterwards), the proportion of cefotaxime prescriptions increased (from 3% to 35%; P = 0.007), and the proportion of appropriate prescriptions increased at the start of treatment (from 45% to 76%; P = 0.064) and at the end (from 76% to 88%; P = 0.450). The daily per-patient cost of treatment was €8 for cefotaxime and from €1.63 to €3.42 for ceftriaxone, depending on the administration route.

CONCLUSIONS

A training session for prescribers was associated with a decrease in ceftriaxone prescriptions encouraging further studies to improve the training session and then evaluate medico-economic impact through randomized clinical trials.