Synergistic effects of sulopenem in combination with cefuroxime or durlobactam against Mycobacterium abscessus.

Mycobacterium abscessus (Mab) affects patients with immunosuppression or underlying structural lung diseases such as cystic fibrosis (CF). Additionally, Mab poses clinical challenges due to its resistance to multiple antibiotics. Herein, we investigated the synergistic effect of dual ß-lactams [sulopenem and cefuroxime (CXM)] or the combination of sulopenem and CXM with ß-lactamase inhibitors [BLIs-avibactam (AVI) or durlobactam (DUR)]. The sulopenem-CXM combination yielded low minimum inhibitory concentration (MIC) values for 54 clinical Mab isolates and ATCC19977 (MIC50 and MIC90 ≤0.25 µg/mL). Similar synergistic effects were observed in time-kill studies conducted at concentrations achievable in clinical settings. Sulopenem-CXM outperformed monotherapy, yielding ~1.5 Log10 CFU/mL reduction during 10 days. Addition of BLIs enhanced this antibacterial effect, resulting in an additional reduction of CFUs (~3 Log10 for sulopenem-CXM and AVI and ~4 Log10 for sulopenem-DUR). Exploration of the potential mechanisms of the synergy focused on their interactions with L,D-transpeptidases (Ldts; LdtMab1-LdtMab4), penicillin-binding-protein B (PBP B), and D,D-carboxypeptidase (DDC). Acyl complexes, identified via mass spectrometry analysis, demonstrated the binding of sulopenem with LdtMab2-LdtMab4, DDC, and PBP B and CXM with LdtMab2 and PBP B. Molecular docking and mass spectrometry data suggest the formation of a covalent adduct between sulopenem and LdtMab2 after the nucleophilic attack of the cysteine residue at the ß-lactam carbonyl carbon, leading to the cleavage of the ß-lactam ring and the establishment of a thioester bond linking the LdtMab2 with sulopenem. In conclusion, we demonstrated the biochemical basis of the synergy of sulopenem-CXM with or without BLIs. These findings potentially broaden the selection of oral therapeutic agents to combat Mab. IMPORTANCE: Treating infections from Mycobacterium abscessus (Mab), particularly those resistant to common antibiotics like macrolides, is notoriously difficult, akin to a never-ending struggle for healthcare providers. The rate of treatment failure is even higher than that seen with multidrug-resistant tuberculosis. The role of combination ß-lactams in inhibiting L,D-transpeptidation, the major peptidoglycan crosslink reaction in Mab, is an area of intense investigation, and clinicians have utilized this approach in the treatment of macrolide-resistant Mab, with reports showing clinical success. In our study, we found that cefuroxime and sulopenem, when used together, display a significant synergistic effect. If this promising result seen in lab settings, translates well into real-world clinical effectiveness, it could revolutionize current treatment methods. This combination could either replace the need for more complex intravenous medications or serve as a "step down" to an oral medication regimen. Such a shift would be much easier for patients to manage, enhancing their comfort and likelihood of sticking to the treatment plan, which could lead to better outcomes in tackling these tough infections. Our research delved into how these drugs inhibit cell wall synthesis, examined time-kill data and binding studies, and provided a scientific basis for the observed synergy in cell-based assays.

Durlobactam, a Diazabicyclooctane ß-Lactamase Inhibitor, Inhibits BlaC and Peptidoglycan Transpeptidases of Mycobacterium tuberculosis.

Peptidoglycan synthesis is an underutilized drug target in Mycobacterium tuberculosis (Mtb). Diazabicyclooctanes (DBOs) are a class of broad-spectrum ß-lactamase inhibitors that also inhibit certain peptidoglycan transpeptidases that are important in mycobacterial cell wall synthesis. We evaluated the DBO durlobactam as an inhibitor of BlaC, the Mtb ß-lactamase, and multiple Mtb peptidoglycan transpeptidases (PonA1, LdtMt1, LdtMt2, LdtMt3, and LdtMt5). Timed electrospray ionization mass spectrometry (ESI-MS) captured acyl-enzyme complexes with BlaC and all transpeptidases except LdtMt5. Inhibition kinetics demonstrated durlobactam was a potent and efficient DBO inhibitor of BlaC (KI app 9.2 ± 0.9 µM, k2/K 5600 ± 560 M-1 s-1) and similar to clavulanate (KI app 3.3 ± 0.6 µM, k2/K 8400 ± 840 M-1 s-1); however, durlobactam had a lower turnover number (tn = kcat/kinact) than clavulanate (1 and 8, respectively). KI app values with durlobactam and clavulanate were similar for peptidoglycan transpeptidases, but ESI-MS captured durlobactam complexes at more time points. Molecular docking and simulation demonstrated several productive interactions of durlobactam in the active sites of BlaC, PonA1, and LdtMt2. Antibiotic susceptibility testing was conducted on 11 Mtb isolates with amoxicillin, ceftriaxone, meropenem, imipenem, clavulanate, and durlobactam. Durlobactam had a minimum inhibitory concentration (MIC) range of 0.5-16 µg/mL, similar to the ranges for meropenem (1-32 µg/mL) and imipenem (0.5-64 µg/mL). In ß-lactam + durlobactam combinations (1:1 mass/volume), MICs were lowered 4- to 64-fold for all isolates except one with meropenem-durlobactam. This work supports further exploration of novel ß-lactamase inhibitors that target BlaC and Mtb peptidoglycan transpeptidases.

The burden of RSV, hMPV, and PIV amongst hospitalized adults in the United States from 2016 to 2019.

BACKGROUND: Respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and parainfluenza virus (PIV) hospitalize many people yearly. Though severe lower respiratory tract disease has been described in children, the elderly, and the immunocompromised, there is a gap in our understanding of RSV, hMPV, and PIV in hospitalized adults. We sought to evaluate the association of RSV, hMPV, and PIV with severe respiratory disease requiring noninvasive or mechanical ventilation and death in hospitalized adults in the United States. METHODS: We conducted a retrospective, pooled, cross-sectional study of general medicine hospitalizations in the United States from 2016 to 2019 using the National Inpatient Sample published by the Agency for Healthcare Quality and Research. We used multivariable Poisson regression to estimate the likelihood of severe respiratory disease or death. We used linear regression to estimate the mean difference in length of stay for those hospitalized with and without a respiratory virus. RESULTS: We found that RSV (incidence rate ratio [IRR]: 1.68, 95% confidence interval [CI]: 1.61-1.74, p < .001), hMPV (IRR: 1.82, 95% CI: 1.71-1.93, p < .001), and PIV (IRR: 1.81, 95% CI: 1.68-1.94, p < .001) were independently associated with severe respiratory disease, even after adjustment. Additionally, we found the presence of a respiratory virus prolonged hospitalizations by (0.79 ± 0.27 days, p < .003) for RSV, (0.88 ± 0.28 days, p < .002) for hMPV, and (1.43 ± 0.30 days, p < .001) for PIV. CONCLUSIONS: RSV, hMPV, and PIV have a significant burden on hospitalized adults, even without classic risk factors.

Case Commentary: Another prong of attack? Topical antibiotic instillation with negative pressure wound therapy for nontuberculous mycobacterial skin and soft tissue infections.

Nontuberculous mycobacteria (NTM) skin infections remain therapeutically challenging. Given the diversity in infections, host responses, and antimicrobials, clinical guidelines are often built on case series and observational studies. In this commentary, we respond to a paper by Stemkens et al. that introduces an emerging strategy: adjunctive negative pressure wound therapy with instillation and dwell time combined with topical antibiotics for refractory NTM skin and soft tissue infections. We delve into the primary considerations surrounding this innovative approach.

The Role of Postoperative Nasal Stents in Cleft Rhinoplasty: A Systematic Review.

OBJECTIVE: To evaluate the role of postoperative nasal stenting in preserving nasal shape and preventing nostril stenosis in cleft rhinoplasty, and to develop a classification system for postoperative nasal stents. DESIGN: Systematic review. METHODS: Electronic and manual searches of scientific literature were conducted from 3 databases (PubMed, SCOPUS, OVID). Primary evidence that described postoperative nasal stenting in cleft rhinoplasty were included. Exclusion criteria included secondary evidence, non-English articles, and studies focusing on preoperative nasal stents. PATIENTS AND PARTICIPANTS: Patients with cleft lip/nose of any type were included. MAIN OUTCOME MEASURE(S): Role in preservation of nasal shape & symmetry, role in prevention of nostril stenosis, complications with the use of postoperative nasal stent. RESULTS: Of the 13 articles, 9 papers described the preservation of nasal shape with nasal stents and three studies with a control group showed improved symmetry score. No studies evaluated the prevention of nostril stenosis; however, 2 studies reported improvement of nostril stenosis in secondary cleft rhinoplasty. The results of the included studies had significant heterogeneity. Nasal stents were classified into five types: Type I-spare parts assembled, Type II-prefabricated commercial, Type IIIa-patient specific 3D-printed static, Type IIIb-patient specific dynamic, and Type IV-internal absorbable. Total complications were 6.0%, including irritation (0.9%), infection (0.3%), and stent loss (4.6%). CONCLUSION: Despite the lack of consensus with postoperative nasal stents, this review suggests its safety and role in preserving shape and improving stenosis. Our classification system highlights variability and the need for better quality studies to determine the efficacy of nasal stents.

Practice Trends in the Management of Asymptomatic Breast Reconstruction Patients with Textured Implants: A Survey Analysis.

Despite the increasing prevalence of breast implant associated anaplastic large cell lymphoma, there remains a paucity of literature guiding management of asymptomatic patients with textured breast implants. This risk can be anxiety provoking in breast reconstruction patients given their history of cancer or increased future risk. The purpose of this study is to evaluate current practice trends when managing the concerned asymptomatic patient following textured implant-based breast reconstruction. Methods: An electronic survey was distributed to members of the American Society of Plastic Surgeons, regarding management of asymptomatic breast reconstruction patients with textured devices. Anonymous responses were collected, and statistical analysis was performed. Results: A total of 304 responses were received. Of respondents, 237 (92%) have managed asymptomatic patients with textured devices. Historically, the overwhelming majority (89%) used textured devices; however, only 25% report current use. Regarding management of asymptomatic breast reconstruction patients, 87% recommend conservative management, while 13% recommend surgical management. When surgery is performed, 16.3% of respondents elected for implant exchange, 33.8% recommended implant exchange with partial capsulectomy, and 49.8% elected for implant exchange with total capsulectomy. Evaluation of practice patterns based on demographics demonstrated statistically significant differences in current use of textured devices and management of acellular dermal matrix. Conclusions: Despite decreased current use, there is a significant population of asymptomatic breast reconstruction patients with a history of textured devices concerned for risk of breast implant associated anaplastic large cell lymphoma. This survey demonstrates ongoing variability in surgeon recommendations regarding conservative and surgical management of these patients and the need for continued development of evidence-based guidelines.

Tailored Treatment Based on Helicobacter pylori Genetic Markers of Resistance Is Associated With Higher Eradication Success.

INTRODUCTION: Increasing antimicrobial resistance with Helicobacter pylori infection has focused efforts to tailor eradication therapy based on identifying genetic markers of resistance to predict antimicrobial susceptibility. METHODS: In this retrospective study, we report the effect of routine inclusion of antimicrobial susceptibility testing and recommendations for eradication therapy with gastric specimens with H. pylori . RESULTS: The use of a recommended treatment regimen based on genetic markers of resistance was associated with an 84% rate of eradication success and 4.4 greater odds of eradication relative to unrecommended treatment. DISCUSSION: This is the first study describing the use of H. pylori genetic resistance testing as standard of care.

Inhibiting Mycobacterium abscessus Cell Wall Synthesis: Using a Novel Diazabicyclooctane ß-Lactamase Inhibitor To Augment ß-Lactam Action.

Mycobacterium abscessus (Mab) infections are a growing menace to the health of many patients, especially those suffering from structural lung disease and cystic fibrosis. With multidrug resistance a common feature and a growing understanding of peptidoglycan synthesis in Mab, it is advantageous to identify potent ß-lactam and ß-lactamase inhibitor combinations that can effectively disrupt cell wall synthesis. To improve existing therapeutic regimens to address serious Mab infections, we evaluated the ability of durlobactam (DUR), a novel diazobicyclooctane ß-lactamase inhibitor to restore in vitro susceptibilities in combination with ß-lactams and provide a biochemical rationale for the activity of this compound. In cell-based assays, susceptibility of Mab subsp. abscessus isolates to amoxicillin (AMOX), imipenem (IMI), and cefuroxime (CXM) was significantly enhanced with the addition of DUR. The triple drug combinations of CXM-DUR-AMOX and IMI-DUR-AMOX were most potent, with MIC ranges of ≤0.06 to 1 µg/mL and an MIC50/MIC90 of ≤0.06/0.25 µg/mL, respectively. We propose a model by which this enhancement may occur, DUR potently inhibited the ß-lactamase BlaMab with a relative Michaelis constant (Ki app) of 4 × 10-3 ± 0.8 × 10-3 µM and acylation rate (k2/K) of 1 × 107 M-1 s-1. Timed mass spectrometry captured stable formation of carbamoyl-enzyme complexes between DUR and LdtMab2-4 and Mab d,d-carboxypeptidase, potentially contributing to the intrinsic activity of DUR. Molecular modeling showed unique and favorable interactions of DUR as a BlaMab inhibitor. Similarly, modeling showed how DUR might form stable Michaelis-Menten complexes with LdtMab2-4 and Mab d,d-carboxypeptidase. The ability of DUR combined with amoxicillin or cefuroxime and imipenem to inactivate multiple targets such as d,d-carboxypeptidase and LdtMab2,4 supports new therapeutic approaches using ß-lactams in eradicating Mab. IMPORTANCE Durlobactam (DUR) is a potent inhibitor of BlaMab and provides protection of amoxicillin and imipenem against hydrolysis. DUR has intrinsic activity and forms stable acyl-enzyme complexes with LdtMab2 and LdtMab4. The ability of DUR to protect amoxicillin and imipenem against BlaMab and its intrinsic activity along with the dual ß-lactam target redundancy can explain the rationale behind the potent activity of this combination.

"One-Two Punch": Synergistic ß-Lactam Combinations for Mycobacterium abscessus and Target Redundancy in the Inhibition of Peptidoglycan Synthesis Enzymes.

Mycobacterium abscessus subsp. abscessus is one of the most difficult pathogens to treat and its incidence in disease is increasing. Dual ß-lactam combinations act synergistically in vitro but are not widely employed in practice. A recent study shows that a combination of imipenem and ceftaroline significantly lowers the minimum inhibitory concentration of clinical isolates, despite both drugs targeting the same peptidoglycan synthesis enzymes. The underlying mechanism of this effect provides a basis for further investigations of dual ß-lactam combinations in the treatment of M. abscessus subsp. abscessus, eventually leading to a clinical trial. Furthermore, dual ß-lactam strategies may be explored for other difficult mycobacterial infections.

Pediatric Case of Severe COVID-19 With Shock and Multisystem Inflammation.

While the majority of pediatric coronavirus disease 2019 (COVID-19) cases have not been critical, occurrences of a multisystem inflammatory syndrome in children (MIS-C) have been emerging as the pandemic progresses. Herein, we report our experience with a pediatric COVID-19 case that presented with shock and multisystem inflammation. Our patient notably had multiple negative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction (RT-PCR) assays but tested positive for SARS-CoV-2 IgG antibody. This case not only highlights the utility of SARS-CoV-2 IgG in the diagnosis of COVID-19 when RT-PCR is negative but suggests MIS-C may be a post-infectious immune-mediated process.

The Clinical and Molecular Epidemiology of CTX-M-9 Group Producing Enterobacteriaceae Infections in Children.

INTRODUCTION: The pandemic of extended-spectrum beta-lactamase-(ESBL)-producing Enterobacteriaceae (Ent) is strongly linked to the dissemination of CTX-M-type-ESBL-Ent. We sought to define the epidemiology of infections in children due to an emerging resistance type, CTX-M-9-group-producing-Ent (CTX-M-9-grp-Ent). METHODS: A retrospective matched case-control analysis of children with CTX-M-9-grp-Ent infections who received medical care at three Chicago area hospitals was performed. Cases were defined as children possessing extended-spectrum cephalosporin-resistant (ESC-R) infections due to blaCTX-M-9. PCR and DNA analysis assessed beta-lactamase (bla) genes, multi-locus sequence types (MLST) and phylogenetic grouping of E. coli. Controls were children with ESC-susceptible (ESC-S)-Ent infections matched one case to three controls by age, source, and hospital. The clinical-epidemiologic predictors of CTX-M-9-grp-Ent infection were assessed. RESULTS: Of 356 ESC-R-Ent isolates from children (median age 4.1 years), the CTX-M-9-group was the solely detected bla gene in 44 (12.4%). The predominant species was E. coli (91%) of virulent phylogroups D (60%) and B2 (40%). MLST revealed multiple strain types. On multivariable analysis, CTX-M-9-grp-Ent occurred more often in E. coli than other Ent genera (OR 7.4, 95% CI 2.4, 27.2), children of non-Black-White-Hispanic race (OR 7.4, 95% CI 2.4, 28.2), and outpatients (OR 4.5, 95% CI 1.7, 12.3), which was a very unexpected finding for infections due to antibiotic-resistant bacteria. Residents of South Chicago had a 6.7 times higher odds of having CTX-M-9-grp-Ent infections than those in the reference region (West), while residence in Northwestern Chicago was associated with an 81% decreased odds of infection. Other demographic, comorbidity, invasive-device, and antibiotic use differences were not found. CONCLUSION: CTX-M-9-grp-Ent infection may be associated with patient residence and is occurring in children without traditional in-patient exposure risk factors. This suggests that among children, the community environment may be a key contributor in the spread of these resistant pathogens.

Possible Garcinia cambogia-Induced Mania With Psychosis: A Case Report.

Garcinia cambogia is a Southeast Asian fruit becoming increasingly popular as a weight management supplement. Hydroxycitric acid (HCA) is the primary active ingredient which demonstrates serotonergic- and muscarinic-enhancing properties via inhibition of selective serotonin reuptake and acetylcholinesterase. We report a young adult female with no history of bipolar disorder who developed mania and psychosis approximately 1 week following initiation of G cambogia and the Cleanse and Detox™ dietary supplement manufactured by Apex Vitality Health. She presented with a predominantly expansive mood, psychomotor agitation, disorganized and pressured speech, flight of ideas, grandiosity, delusions, and auditory hallucinations. Following discontinuation of G cambogia and the initiation of lithium and quetiapine, the patient experienced rapid and progressive mood stabilization and was discharged after 8 days. Seven previous case reports associating (hypo)mania and/or psychosis with G cambogia consumption have been published. The chronology of mania and/or psychosis onset may appear between 1 and 8 weeks following initiation of G cambogia. Psychiatric symptoms have resolved with G cambogia discontinuation in some instances and may not require chronic pharmacotherapy. Our report should encourage further research and case reports regarding this adverse event and the reconciliation of complete herbal supplement use at clinic visits and hospital admissions.

A Multi-Centered Case-Case-Control Study of Factors Associated With Klebsiella pneumoniae Carbapenemase-Producing Enterobacteriaceae Infections in Children and Young Adults.

BACKGROUND: Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae (KPC-CRE) are multidrug-resistant organisms causing morbidity and mortality worldwide. KPC-CRE prevalence is increasing in pediatric populations, though multi-centered data are lacking. Identifying risk factors for KPC-CRE infection in children and classifying genotypes is a priority in this vulnerable population. METHODS: A case-case-control study of patients (0-22 years) at 3 tertiary-care Chicago-area medical centers, 2008-2015, was conducted. Case group 1 children possessed KPC-CRE infections; case group 2 harbored carbapenem-susceptible Enterobacteriaceae (CSE) infections; controls had negative cultures. Case-control matching was 1:1:3 by age, infection site and hospital. Statistical and molecular analyses were performed. RESULTS: Eighteen KPC-CRE infections were identified; median patient age was 16.5 years. Of 4 available KPC-CRE, 2 were unrelated, non-ST258 KP strains harboring blaKPC-2, one was a ST258 KP harboring blaKPC-3, and the last was an E. coli containing blaKPC-2. KPC-CRE and CSE-infected patients had more multidrug-resistant organisms infections, long-term care facility admissions and lengths of stay (LOS) > 7 days before culture. KPC-CRE and CSE patients had more gastrointestinal comorbidities (odds ratios [Ors], 28.0 and 6.4) and ≥ 3 comorbidities (Or 15.4 and 3.5) compared with controls; KPC-CRE patients had significantly more pulmonary and neurologic comorbidities (both ORs 4.4) or GI and pulmonary devices (ORs, 11.4 and 6.1). Compared with controls, CSE patients had more prior fluoroquinolone use (OR, 7.4); KPC-CRE patients had more carbapenem or aminoglycoside use (ORs, 10.0 and 8.0). Race, gender, LOS and mortality differences were insignificant. CONCLUSIONS: Pediatric patients with KPC-CRE infection suffer from high multi-system disease/device burdens and exposures to carbapenems and aminoglycosides. Different from adult reports, non-ST258 KP strains were more common, and LOS and mortality rates were similar in all groups. Pediatric CRE control in should focus on modifiable risk factors including antibiotic and device utilization.

Treatment of Breast Animation Deformity in Implant-Based Reconstruction with Selective Nerve Ablation.

Breast animation deformity is a known complication of subpectoral implant placement that is usually corrected by repositioning the implant to the prepectoral position. Other less common treatment options include performing the muscle splitting biplanar technique, triple plane technique, neuromodulator injections, and secondary neurotomies via transection of the pectoral muscle. We report a patient with animation deformity successfully treated with direct identification and ablation of the medial and lateral pectoral nerves using selective bipolar electrocautery. The patient is a woman with a history of invasive ductal carcinoma who underwent bilateral mastectomy and breast reconstruction with subpectoral implant placement and autologous fat grafting. Within 1 year of her breast reconstruction, she developed hyperactive pectoralis muscle contraction with resulting distortion of both breasts. Given the disadvantages of repositioning the implant to the prepectoral position and transecting the pectoralis muscles via secondary neurotomy, we chose to directly identify and selectively ablate distal branches of the medial and lateral pectoral nerves. This offers a novel technique for correcting breast animation deformity without transecting the pectoralis muscles, causing muscle atrophy, and preserving the subpectoral implant position.Level of Evidence V This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the table of contents or the online instructions to authors www.springer.com/00266 .

The Dieulafoy's Lesion: An Update on Evaluation, Diagnosis, and Management.

Dieulafoy's lesion (DL) is a persistently wide caliber artery that is observed more frequently at the fifth decade of life in the male population with multiple comorbidities. There are a variety of endoscopic therapies that have been used to treat DL; however, there are no clear guidelines on the best treatment modality. This article systematically reviews the diagnosis, the most commonly reported therapies of DL, and offers a suggested algorithm based upon efficacy of treatment such as initial hemostasis, rebleeding rates, and mortality.