RESUMO
ANT3310 is a novel broad-spectrum diazabicyclooctane serine ß-lactamase inhibitor being developed in combination with meropenem (MEM) for the treatment of serious infections in hospitalized patients where carbapenem-resistant Gram-negative pathogens are expected. In this study, we evaluated the in vitro antibacterial activity of MEM in the presence of ANT3310 at 8 µg/mL against global clinical isolates that included Acinetobacter baumannii (n = 905), carbapenem-resistant Enterobacterales (CRE), carrying either oxacillinase (OXA) (n = 252) or Klebsiella pneumoniae carbapenemase (KPC) (n = 180) carbapenemases, and Pseudomonas aeruginosa (n = 502). MEM was poorly active against A. baumannii, as were MEM-vaborbactam, ceftazidime-avibactam, aztreonam-avibactam, cefepime-taniborbactam, cefepime-zidebactam, and imipenem-relebactam (MIC90 values of ≥32 µg/mL). On the other hand, MEM-ANT3310 displayed an MIC90 value of 4 µg/mL, similar to that observed with sulbactam-durlobactam, a drug developed to specifically treat A. baumannii infections. ANT3310 (8 µg/mL) additionally restored the activity of MEM against OXA- and KPC-producing CREs decreasing MEM MIC90 values from >32 µg/mL to 0.25 and 0.5 µg/mL, respectively. The combination of 8 µg/mL of both MEM and ANT3310 prevented growth of 97.5% of A. baumannii and 100% of OXA- and KPC-positive CREs, with ~90% of P. aeruginosa isolates also displaying MEM MICs ≤8 µg/mL. Furthermore, MEM-ANT3310 was efficacious in both thigh and lung murine infection models with OXA-23 A. baumannii. This study demonstrates the potent in vitro activity of the MEM-ANT3310 combination against both carbapenem-resistant A. baumannii and Enterobacterales clinical isolates, a key differentiator to other ß-lactam/ß-lactamase combinations.
Assuntos
Acinetobacter baumannii , Inibidores de beta-Lactamases , Humanos , Animais , Camundongos , Meropeném/farmacologia , Inibidores de beta-Lactamases/farmacologia , Lactamas , Antibacterianos/farmacologia , beta-Lactamases , Carbapenêmicos/farmacologia , Compostos Azabicíclicos/farmacologia , Combinação de Medicamentos , Testes de Sensibilidade MicrobianaRESUMO
Pseudomonas aeruginosa is a common pathogen in cystic fibrosis (CF) patients and a major contributor to progressive lung damage. P. aeruginosa elastase (LasB), a key virulence factor, has been identified as a potential target for anti-virulence therapy. Here, we sought to differentiate the P. aeruginosa isolates from early versus established stages of infection in CF patients and to determine if LasB was associated with either stage. The lasB gene was amplified from 255 P. aeruginosa clinical isolates from 70 CF patients from the Toulouse region (France). Nine LasB variants were identified and 69% of the isolates produced detectable levels of LasB activity. Hierarchical clustering using experimental and clinical data distinguished two classes of isolates, designated as 'Early' and 'Established' infection. Multivariate analysis revealed that the isolates from the Early infection class show higher LasB activity, fast growth, tobramycin susceptibility, non-mucoid, pigmented colonies and wild-type lasR genotype. These traits were associated with younger patients with polymicrobial infections and high pFEV1. Our findings show a correlation between elevated LasB activity in P. aeruginosa isolates and early-stage infection in CF patients. Hence, it is this patient group, prior to the onset of chronic disease, that may benefit most from novel therapies targeting LasB.
Assuntos
Coinfecção , Fibrose Cística , Humanos , Pseudomonas aeruginosa/genética , Fibrose Cística/complicações , Análise por Conglomerados , Elastase PancreáticaRESUMO
LasB elastase is a broad-spectrum exoprotease and a key virulence factor of Pseudomonas aeruginosa, a major pathogen causing lung damage and inflammation in acute and chronic respiratory infections. Here, we describe the chemical optimization of specific LasB inhibitors with druglike properties and investigate their impact in cellular and animal models of P. aeruginosa infection. Competitive inhibition of LasB was demonstrated through structural and kinetic studies. In vitro LasB inhibition was confirmed with respect to several host target proteins, namely, elastin, IgG, and pro-IL-1ß. Furthermore, inhibition of LasB-mediated IL-1ß activation was demonstrated in macrophage and mouse lung infection models. In mice, intravenous administration of inhibitors also resulted in reduced bacterial numbers at 24 h. These highly potent, selective, and soluble LasB inhibitors constitute valuable tools to study the proinflammatory impact of LasB in P. aeruginosa infections and, most importantly, show clear potential for the clinical development of a novel therapy for life-threatening respiratory infections caused by this opportunistic pathogen.
Assuntos
Pseudomonas aeruginosa , Fatores de Virulência , Animais , Camundongos , Cinética , Modelos Animais , Elastase PancreáticaRESUMO
The global dissemination of metallo-ß-lactamase (MBL)-producing carbapenem-resistant Enterobacterales (CRE) is a serious public health concern. Specifically, NDM (New Delhi MBL) has been a major cause of carbapenem therapy failures in recent years, particularly as effective treatments for serine-ß-lactamase (SBL)-producing Enterobacterales are now commercially available. Since the NDM gene is carried on promiscuous plasmids encoding multiple additional resistance determinants, a large proportion of NDM-CREs are also resistant to many commonly used antibiotics, resulting in limited and suboptimal treatment options. ANT2681 is a specific, competitive inhibitor of MBLs with potent activity against NDM enzymes, progressing to clinical development in combination with meropenem (MEM). Susceptibility studies have been performed with MEM-ANT2681 against 1,687 MBL-positive Enterobacterales, including 1,108 NDM-CRE. The addition of ANT2681 at 8 µg/ml reduced the MEM MIC50/MIC90 from >32/>32 µg/ml to 0.25/8 µg/ml. Moreover, the combination of 8 µg/ml of both MEM and ANT2681 inhibited 74.9% of the Verona integron-encoded MBL (VIM)-positive and 85.7% of the imipenem hydrolyzing ß-lactamase (IMP)-positive Enterobacterales tested. The antibacterial activity of MEM-ANT2681 against NDM-CRE compared very favorably to that of cefiderocol (FDC) and cefepime (FEP)-taniborbactam, which displayed MIC90 values of 8 µg/ml and 32 µg/ml, respectively, whereas aztreonam-avibactam (ATM-AVI) had a MIC90 of 0.5 µg/ml. Particularly striking was the activity of MEM-ANT2681 against NDM-positive Escherichia coli (MIC90 1 µg/ml), in contrast to ATM-AVI (MIC90 4 µg/ml), FDC (MIC90 >32 µg/ml), and FEP-taniborbactam (MIC90 >32 µg/ml), which were less effective due to the high incidence of resistant PBP3-insertion mutants. MEM-ANT2681 offers a potential new therapeutic option to treat serious infections caused by NDM-CRE.
Assuntos
Ácidos Borínicos , Inibidores de beta-Lactamases , Antibacterianos/farmacologia , Ácidos Carboxílicos , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/genéticaRESUMO
Ever since the first ß-lactam antibiotic, penicillin, was introduced into the clinic over 70 years ago, resistance has been observed because of the presence of ß-lactamase enzymes, which hydrolyze the ß-lactam ring of ß-lactam antibiotics. Early ß-lactamase enzymes were all of the serine ß-lactamase (SBL) type, but more recently, highly resistant Gram-negative strains have emerged in which metallo-ß-lactamase (MBL) enzymes are responsible for resistance. The two types of ß-lactamase enzymes are structurally and mechanistically different but serve the same purpose in bacteria. The SBLs use an active serine group as a nucleophile to attack the ß-lactamase ring, forming a covalent intermediate that is subsequently hydrolyzed. In contrast, the MBLs use a zinc ion to activate the ß-lactam toward nucleophilic attack by a hydroxide anion held between two zinc ions. In this Account, we review our recent contribution to the field of ß-lactamase inhibitor design in terms of both SBL and MBL inhibitors. We describe how we have approached these challenges from the particular perspective of a small biotechnology company, identifying new inhibitors when faced with either a paucity of starting points for medicinal chemistry (MBL inhibitors) or else an abundance of prior research necessitating a search for novelty, improvement, and differentiation (SBL inhibitors). During the journey from the beginning of lead optimization to successful identification of a preclinical candidate for development, we encountered and solved a range of issues. For example, in the MBL inhibitor series we were able to prevent metabolic cleavage of a glycinamide moiety by circulating amidases while still retaining the activity by converting the amino group into a guanidine. In the SBL inhibitor series, the structure-activity relationship led us to consider introducing a fluorine substituent adjacent to a urea functionality. At first sight this grouping would appear to be chemically unstable. However, deeper theoretical considerations suggested that this would not be the case, and in practice the compound is remarkably stable. Both examples serve to illustrate the importance of scientific insight and the necessity to explore speculative hypotheses as part of the creative medicinal chemistry process.
Assuntos
Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Desenho de Fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/metabolismo , Antibacterianos/síntese química , Antibacterianos/química , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Inibidores de beta-Lactamases/síntese química , Inibidores de beta-Lactamases/químicaRESUMO
Why is P. aeruginosa LasB elastase an attractive target for antivirulence therapy and what is the state-of-the art in LasB inhibitor design and development?
Assuntos
Antibacterianos/uso terapêutico , Proteínas de Bactérias/antagonistas & inibidores , Metaloendopeptidases/antagonistas & inibidores , Elastase Pancreática/antagonistas & inibidores , Infecções por Pseudomonas/tratamento farmacológico , Animais , Proteínas de Bactérias/metabolismo , Desenvolvimento de Medicamentos , Humanos , Metaloendopeptidases/metabolismo , Elastase Pancreática/metabolismo , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/patogenicidade , VirulênciaRESUMO
Novel therapies are required to treat chronic bacterial infections in cystic fibrosis (CF) sufferers. The most common pathogen responsible for these infections is Pseudomonas aeruginosa, which persists within the lungs of CF sufferers despite intensive antibiotic treatment. P. aeruginosa elastase (also known as LasB or pseudolysin) is a key virulence determinant that contributes to the pathogenesis and persistence of P. aeruginosa infections in CF patients. The crucial role of LasB in pseudomonal virulence makes it a good target for the development of an adjuvant drug for CF treatment. Herein we discuss the discovery of a new series of LasB inhibitors by virtual screening and computer assisted drug design (CADD) and their optimization leading to compounds 29 and 39 (K i = 0.16 µM and 0.12 µM, respectively).
RESUMO
Resumen: A partir del año 2017, la Facultad de Medicina de la Universidad de la República (UdelaR) incorpora la enseñanza en reanimación cardíaca avanzada como actividad curricular obligatoria durante el Ciclo Internado Rotatorio (CIR). Esto se justifica dada la relevancia que presenta en términos de morbilidad y mortalidad la patología cardiovascular, en particular los paros cardiorrespiratorios y específicamente la muerte súbita. Los cursos de reanimación permiten la adquisición de habilidades técnicas y no técnicas para dar respuesta tanto a esta patología tan prevalente como a la falta de estos cursos en la formación médica. Los objetivos del trabajo son comunicar y evaluar la primera experiencia durante el CIR 2017-2018. Para dichos objetivos se realizó un estudio transversal donde se analizaron los números de participantes y el porcentaje de aprobados. Además, se realizó una encuesta de valoración de autopercepción de habilidades previas y posteriores al curso y una evaluación de conformidad con éste. De los resultados se desprende la amplia aprobación en una primera instancia del curso y la valoración positiva que se realiza. También es positiva la mejora en la autopercepción de habilidades identificadas por los internos. Como debilidad se desprende el uso de un cuestionario no validado y que la evaluación no fue completada por todos los internos, ambos aspectos a mejorar en futuras evaluaciones. Como conclusión, se logró comunicar la experiencia, los cursos de Resucitación cardíaca avanzda (RCA) son una fortaleza en sí mismos y han sido un avance significativo en la formación profesional del futuro médico.
Summary: In 2017 the School of Medicine of the University of the Republic included advanced cardiopulmonary resuscitation as a mandatory curricular activity during the rotating internship. The decision is justified by morbility and mortality rates of heart disease, in particular cardiopulmonary arrests and sudden death. Resuscitation courses enable the acquisition of technical and non- technical skills to respond to a prevalent condition and to compensate the absence of this specific training in the training of medical doctors. The study aimed to communicate and evaluate the first experience during the 2017-2018 rotating internship. A transversal study was conducted to analyse the number of participants and the percentage of successful candidates. Likewise, a survey was designed to assess self-perception of skills prior to the course and skills acquired during the course, as well as a course satisfaction. Results revealed the high acceptance rate of this first instance of the course and its positive assessment. Similarly, interns evidenced improvement in their self-perception of identified skills. As to a weaknesses found, the questionnaire used had not been validated and not all Interns completed the assessment, both aspects that will be improved in future assessments. To conclude, we managed to inform about the experience, advanced cardiopulmonary resuscitation courses are an advantage in itself, and it has been a significant advance in the professional training of future medical doctors.
Resumo: A partir de 2017, a Faculdade de Medicina da Universidad de la República (UdelaR) incorporou o ensino de ressuscitação cardíaca avançada como atividade curricular obrigatória durante o ciclo de estágio rotativo (CIR). Isso se justifica dada a relevância das doenças cardiovasculares em termos de morbimortalidade, em especial a parada cardiorrespiratória e especificamente a morte súbita. Os cursos de reanimação permitem a aquisição de competências técnicas e não técnicas para responder, tanto a esta patologia prevalente, como à falta destes cursos na formação médica. Os objetivos deste trabalho são comunicar e avaliar a primeira experiência durante o Ciclo de Estágios Rotativo 2017-2018. Com esse fim foi realizado um estudo transversal onde foram analisados o número de participantes e o percentual de aprovação. Além disso, foi realizada uma pesquisa para avaliar a autopercepção de habilidades antes e depois do curso, bem como uma avaliação da adesão ao curso. Os resultados mostram a ampla aprovação na primeira instância do curso e a avaliação positiva que se faz do mesmo. A melhora na autopercepção das habilidades identificadas pelos estagiários também é positiva. Como fragilidade, surge a utilização de um questionário não validado e que a avaliação não foi respondida por todos os internos, aspectos que devem ser melhorados em avaliações futuras. Como conclusão foi possível comunicar a experiência, os cursos RCA são uma força em si e têm sido um avanço significativo na formação profissional do futuro médico.
Assuntos
Reanimação Cardiopulmonar/educação , Internato e Residência , Medicina Clínica/métodos , Educação MédicaRESUMO
The diazabicyclooctanes (DBOs) are a class of serine ß-lactamase (SBL) inhibitors that use a strained urea moiety as the warhead to react with the active serine residue in the active site of SBLs. The first in-class drug, avibactam, as well as several other recently approved DBOs (e.g., relebactam) or those in clinical development (e.g., nacubactam and zidebactam) potentiate activity of ß-lactam antibiotics, to various extents, against carbapenem-resistant Enterobacterales (CRE) carrying class A, C, and D SBLs; however, none of these are able to rescue the activity of ß-lactam antibiotics against carbapenem-resistant Acinetobacter baumannii (CRAB), a WHO "critical priority pathogen" producing class D OXA-type SBLs. Herein, we describe the chemical optimization and resulting structure-activity relationship, leading to the discovery of a novel DBO, ANT3310, which uniquely has a fluorine atom replacing the carboxamide and stands apart from the current DBOs in restoring carbapenem activity against OXA-CRAB as well as SBL-carrying CRE pathogens.
Assuntos
Acinetobacter/efeitos dos fármacos , Antibacterianos/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Octanos/química , beta-Lactamases/química , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Sítios de Ligação , Carbapenêmicos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Farmacorresistência Bacteriana/efeitos dos fármacos , Meia-Vida , Camundongos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Octanos/metabolismo , Octanos/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade , Inibidores de beta-Lactamases/química , Inibidores de beta-Lactamases/metabolismo , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/metabolismoRESUMO
Enterobacteriaceae that produce metallo-ß-lactamases (MBLs) are an emerging threat to public health. The metallo-ß-lactamase inhibitor (MBLi) ANT2681 inhibits the enzymatic activity of MBLs through interaction with the dinuclear zinc ion cluster present in the active site that is common to these enzymes. ANT2681 is being codeveloped, with meropenem as the partner ß-lactam, as a novel combination therapy for infections caused by MBL-producing bacteria. The pharmacokinetics/pharmacodynamics of meropenem-ANT2681 were studied in a murine neutropenic thigh model of NDM-producing Enterobacteriaceae Dose-ranging studies were performed with both meropenem and ANT2681. Dose fractionation experiments were performed to identify the relevant pharmacodynamic index of ANT2681 when coadministered with meropenem. A background of meropenem at 50 mg/kg of body weight every 4 h (q4h) subcutaneously (s.c.) had minimal antibacterial effect. On this background, half-maximal effect was observed with an ANT2681 dose of 89 mg/kg q4h intravenously (i.v.). The dose fractionation study showed that area under the concentration-time curve (AUC) was the relevant pharmacodynamic index for the inhibitor. The magnitude of the meropenem-ANT2681 exposure required to achieve stasis was explored using 5 NDM-producing strains. A 3-dimensional surface fitted to the pharmacodynamic data from the 5 strains suggested that stasis was achieved with an fT > potentiated meropenem MIC of 40% and ANT2681 AUC of 700 mg · h/liter. These data and analyses provide the underpinning evidence for the combined use of meropenem and ANT2681 for clinical infections.
Assuntos
Infecções por Enterobacteriaceae , Inibidores de beta-Lactamases , Animais , Antibacterianos/farmacologia , Enterobacteriaceae , Infecções por Enterobacteriaceae/tratamento farmacológico , Meropeném/farmacologia , Camundongos , Testes de Sensibilidade Microbiana , Monobactamas , Inibidores de beta-Lactamases/farmacologia , beta-LactamasesRESUMO
The clinical effectiveness of the important ß-lactam class of antibiotics is under threat by the emergence of resistance, mostly due to the production of acquired serine- (SBL) and metallo-ß-lactamase (MBL) enzymes. To address this resistance issue, multiple ß-lactam/ß-lactamase inhibitor combinations have been successfully introduced into the clinic over the past several decades. However, all of those combinations contain SBL inhibitors and, as yet, there are no MBL inhibitors in clinical use. Consequently, there exists an unaddressed yet growing healthcare problem due to the rise in recent years of highly resistant strains which produce New Delhi metallo (NDM)-type metallo-carbapenemases. Previously, we reported the characterization of an advanced MBL inhibitor lead compound, ANT431. Herein, we discuss the completion of a lead optimization campaign culminating in the discovery of the preclinical candidate ANT2681, a potent NDM inhibitor with strong potential for clinical development.
Assuntos
Enterobacteriaceae , Inibidores de beta-Lactamases , Antibacterianos/farmacologia , Meropeném/farmacologia , Monobactamas , Inibidores de beta-Lactamases/farmacologiaRESUMO
Chronic infection by Pseudomonas aeruginosa in cystic fibrosis (CF) patients is a major contributor to progressive lung damage and is poorly treated by available antibiotic therapy. An alternative approach to the development of additional antibiotic treatments is to identify complementary therapies which target bacterial virulence factors necessary for the establishment and/or maintenance of the chronic infection. The P. aeruginosa elastase (LasB) has been suggested as an attractive anti-virulence target due to its extracellular location, its harmful degradative effects on host tissues and the immune system, and the potential to inhibit its activity using small molecule inhibitors. However, while the relevance of LasB in acute P. aeruginosa infection has been demonstrated, it is still unclear whether this elastase might also play a role in the early phase of chronic lung colonization. By analyzing clinical P. aeruginosa clonal isolates from a CF patient, we found that the isolate RP45, collected in the early phase of persistence, produces large amounts of active LasB, while its clonal variant RP73, collected after years of colonization, does not produce it. When a mouse model of persistent pneumonia was used, deletion of the lasB gene in RP45 resulted in a significant reduction in mean bacterial numbers and incidence of chronic lung colonization at Day 7 post-challenge compared to those mice infected with wild-type (wt) RP45. Furthermore, deletion of lasB in strain RP45 also resulted in an increase in immunomodulators associated with innate and adaptive immune responses in infected animals. In contrast, deletion of the lasB gene in RP73 did not affect the establishment of chronic infection. Overall, these results indicate that LasB contributes to the adaptation of P. aeruginosa to a persistent lifestyle. In addition, these findings support pharmacological inhibition of LasB as a potentially useful therapeutic intervention for P. aeruginosa-infected CF patients prior to the establishment of a chronic infection.
RESUMO
The clinical effectiveness of carbapenem antibiotics such as meropenem is becoming increasingly compromised by the spread of both metallo-ß-lactamase (MBL) and serine-ß-lactamase (SBL) enzymes on mobile genetic elements, stimulating research to find new ß-lactamase inhibitors to be used in conjunction with carbapenems and other ß-lactam antibiotics. Herein, we describe our initial exploration of a novel chemical series of metallo-ß-lactamase inhibitors, from concept to efficacy, in a survival model using an advanced tool compound (ANT431) in conjunction with meropenem.
Assuntos
Antibacterianos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Infecções por Enterobacteriaceae/tratamento farmacológico , Inibidores de beta-Lactamases/química , Carbapenêmicos/farmacologia , Cristalografia por Raios X , Concentração Inibidora 50 , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Ácidos Picolínicos/química , Ácidos Picolínicos/farmacologia , Ligação Proteica , Relação Estrutura-Atividade , Inibidores de beta-Lactamases/farmacologia , beta-LactamasesRESUMO
There is evidence that relations between physicians and nurses within healthcare institutions might be shaped by informal aspects of such relations and by links to people external to the organization, with an impact on work performance. Social network analysis is underutilized in exploring such associations. The paper aims to describe physicians’ and nurses’ relationships outside their clinical units and to explore what kind of ties are related to job performance. A network analysis was performed on cross-sectional data. The study population consisted of 196 healthcare employees working in a public hospital and a primary healthcare centre in Spain. Relational data were analysed using the UCINET software package. Measures included: (i) sample characteristics; (ii) social network variables; and (iii) team performance ratings. Descriptive statistics (means, medians, percentages) were used to characterize staff and performance ratings. A correlational analysis was conducted to examine the strength of relationships between four different types of ties. Our findings suggest that external ties only contribute to improving the performance of physicians at both the individual and team level. They are focused on the decision-making process about the therapeutic plan and, therefore, might need to seek advice outside the workplace. In contrast, external ties are not relevant for the work performance of nurses, as they need to find solutions to immediate problems in a short period of time, having strong ties in the workplace. Social network analysis can illuminate relations within healthcare organizations and inform the development of innovative interventions.
Assuntos
Pessoal de Saúde/psicologia , Rede Social , Desempenho Profissional , Estudos Transversais , Atenção à Saúde , Avaliação de Desempenho Profissional , Feminino , Humanos , Masculino , Espanha , Local de TrabalhoRESUMO
Infections caused by carbapenem-resistant Enterobacteriaceae (CRE) are increasingly prevalent and have become a major worldwide threat to human health. Carbapenem resistance is driven primarily by the acquisition of ß-lactamase enzymes, which are able to degrade carbapenem antibiotics (hence termed carbapenemases) and result in high levels of resistance and treatment failure. Clinically relevant carbapenemases include both serine ß-lactamases (SBLs; e.g., KPC-2 and OXA-48) and metallo-ß-lactamases (MBLs), such as NDM-1. MBL-producing strains are endemic within the community in many Asian countries, have successfully spread worldwide, and account for many significant CRE outbreaks. Recently approved combinations of ß-lactam antibiotics with ß-lactamase inhibitors are active only against SBL-producing pathogens. Therefore, new drugs that specifically target MBLs and which restore carbapenem efficacy against MBL-producing CRE pathogens are urgently needed. Here we report the discovery of a novel MBL inhibitor, ANT431, that can potentiate the activity of meropenem (MEM) against a broad range of MBL-producing CRE and restore its efficacy against an Escherichia coli NDM-1-producing strain in a murine thigh infection model. This is a strong starting point for a chemistry lead optimization program that could deliver a first-in-class MBL inhibitor-carbapenem combination. This would complement the existing weaponry against CRE and address an important and growing unmet medical need.
Assuntos
Antibacterianos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/genéticaRESUMO
Background: Research suggests that policymakers often use personal contacts to find information and advice. However, the main sources of information for public health policymakers are not known. This study aims to describe policymakers' sources of information. A questionnaire survey of public health policymakers across Greater Manchester (GM) was carried out (response rate 48%). All policy actors above Director level involved in public health policy (finding, analyzing or producing information, producing or implementing policy) in GM were included in the sampling frame. Respondents were provided with a list of sources of information and asked which they used (categorical data) and to name specific individuals who acted as sources of information (network data). Data were analyzed using frequencies and network analysis. The most frequently chosen sources of information from the categorical data were NICE, government websites and Directors of Public Health. However, the network data showed that the main sources of information in the network were actually mid-level managers in the NHS, who had no direct expertise in public health. Academics and researchers did not feature in the network. Both survey and network analyses provide useful insights into how policymakers access information. Network analysis offers practical and theoretical contributions to the evidence-based policy debate. Identifying individuals who act as key users and producers of evidence allows academics to target actors likely to use and disseminate their work.
Assuntos
Pessoal Administrativo/estatística & dados numéricos , Comportamento de Busca de Informação , Prática de Saúde Pública , Humanos , Formulação de Políticas , Prática de Saúde Pública/estatística & dados numéricos , Inquéritos e QuestionáriosRESUMO
Valente and Fujimoto (2010) proposed a measure of brokerage in networks based on Granovetter's classic work on the strength of weak ties. Their paper identified the need for finding node-based measures of brokerage that consider the entire network structure, not just a node's local environment. The measures they propose, aggregating the average change in cohesion for a node's links, has several limitations. In this paper we review their method and show how the idea can be modified by using betweenness centrality as an underpinning concept. We explore the properties of the new method and provide point, normalized, and network level variations. This new approach has two advantages, first it provides a more robust means to normalize the measure to control for network size, and second, the modified measure is computationally less demanding making it applicable to larger networks.
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Cell migration is fundamental to the inflammatory response, but uncontrolled cell migration and excess recruitment of neutrophils and other leukocytes can cause damage to the tissue. Here we describe the use of an in vivo model - the Tg(mpx:GFP)(i114) zebrafish line, in which neutrophils are labelled by green fluorescent protein (GFP) - to screen a natural product library for compounds that can affect neutrophil migratory behaviour. Among 1040 fungal extracts screened, two were found to inhibit neutrophil migration completely. Subfractionation of these extracts identified sterigmatocystin and antibiotic PF1052 as the active components. Using the EZ-TAXIScan chemotaxis assay, both compounds were also found to have a dosage-dependent inhibitory effect on murine neutrophil migration. Furthermore, neutrophils treated with PF1052 failed to form pseudopods and appeared round in shape, suggesting a defect in PI3-kinase (PI3K) signalling. We generated a transgenic neutrophil-specific PtdIns(3,4,5)P3 (PIP3) reporter zebrafish line, which revealed that PF1052 does not affect the activation of PI3K at the plasma membrane. In human neutrophils, PF1052 neither induced apoptosis nor blocked AKT phosphorylation. In conclusion, we have identified an antibiotic from a natural product library with potent anti-inflammatory properties, and have established the utility of the mpx:GFP transgenic zebrafish for high-throughput in vivo screens for novel inhibitors of neutrophil migration.
Assuntos
Antibacterianos/farmacologia , Quimiotaxia/efeitos dos fármacos , Naftalenos/farmacologia , Neutrófilos/citologia , Pirrolidinonas/farmacologia , Esterigmatocistina/farmacologia , Animais , Animais Geneticamente Modificados , Apoptose , Membrana Celular/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Humanos , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos , Neutrófilos/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Frações Subcelulares , Transgenes , Peixe-ZebraRESUMO
BACKGROUND: Persistent health inequalities encourage researchers to identify new ways of understanding the policy process. Informal relationships are implicated in finding evidence and making decisions for public health policy (PHP), but few studies use specialized methods to identify key actors in the policy process. METHODS: We combined network and qualitative data to identify the most influential individuals in PHP in a UK conurbation and describe their strategies to influence policy. Network data were collected by asking for nominations of powerful and influential people in PHP (n = 152, response rate 80%), and 23 semi-structured interviews were analysed using a framework approach. RESULTS: The most influential PHP makers in this conurbation were mid-level managers in the National Health Service and local government, characterized by managerial skills: controlling policy processes through gate keeping key organizations, providing policy content and managing selected experts and executives to lead on policies. Public health professionals and academics are indirectly connected to policy via managers. CONCLUSIONS: The most powerful individuals in public health are managers, not usually considered targets for research. As we show, they are highly influential through all stages of the policy process. This study shows the importance of understanding the daily activities of influential policy individuals.