RESUMEN
Introduction: Our work aims at establishing a proof-of-concept for a method that allows the early prediction of the bactericidal and bacteriostatic effects of antibiotics on bacteria using scanning electron microscopy (SEM) as compared to traditional culture-based methods. Methods: We tested these effects using Imipenem (bactericidal) and Doxycycline (bacteriostatic) with several strains of sensitive and resistant Escherichia coli. We developed a SEM-based predictive score based on three main criteria: Bacterial Density, Morphology/Ultrastructure, and Viability. We determined the results for each of these criteria using SEM micrographs taken with the TM4000Plus II-Tabletop-SEM (Hitachi, Japan) following an optimized, rapid, and automated acquisition and analysis protocol. We compared our method with the traditional culture colony counting gold standard method and classic definitions of the two effects. Results: Our method revealed total agreement with the CFU method and classic definition by visualizing the effect of the antibiotic at 60 minutes and 120 minutes using SEM. Discussion: This early prediction allows a rapid and early identification of the bactericidal and bacteriostatic effects as compared to culture that would take a minimum of 18 hours. This has several future applications in the development of SEM-automated assays coupled to machine learning models that identify the antibiotic effect and facilitate determination of bacterial susceptibility.
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Antibacterianos , Doxiciclina , Escherichia coli , Imipenem , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana , Microscopía Electrónica de Rastreo , Antibacterianos/farmacología , Imipenem/farmacología , Doxiciclina/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/ultraestructura , Viabilidad Microbiana/efectos de los fármacos , Recuento de Colonia MicrobianaRESUMEN
BACKGROUND: Sepsis is a life-threatening organ dysfunction caused by an excessive host response to infection, manifested by elevated levels of inflammatory cytokines. At present, the use of hemoperfusion to remove inflammatory cytokines from the bloodstream has been expanding. Meanwhile, the pharmacokinetics and pharmacodynamics characteristics of antibiotics in critically ill patients may be impacted by hemoperfusion. CASE PRESENTATION: The patient was a 69-year-old male with poorly controlled type 2 diabetes. When admitted to the ICU, Multiple Organ Dysfunction Syndrome (MODS) appeared within 48 h, and he was suspected of septic shock due to acute granulocytopenia and significantly increased procalcitonin. Broad-spectrum antibiotics imipenem was administered according to Sepsis 3.0 bundle and hemoperfusion lasting 4 h with a neutron-macroporous resin device (HA-380, Jafron, China) five times was conducted to lower the extremely high value of serum inflammatory factors. Blood samples were collected to measure imipenem plasma concentration to investigate the effect of hemoperfusion quantitatively. This study showed that 4 h of hemoperfusion had a good adsorption ability on inflammatory factors and could remove about 75.2% of imipenem. CONCLUSIONS: This case demonstrated the high adsorption capacity of hemoperfusion on imipenem in critically ill patients. It implies a timely imipenem supplement is required, especially before hemoperfusion.
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Antibacterianos , Enfermedad Crítica , Hemoperfusión , Imipenem , Choque Séptico , Humanos , Masculino , Imipenem/uso terapéutico , Imipenem/administración & dosificación , Imipenem/farmacocinética , Anciano , Choque Séptico/tratamiento farmacológico , Choque Séptico/terapia , Hemoperfusión/métodos , Antibacterianos/farmacocinética , Antibacterianos/uso terapéutico , Antibacterianos/administración & dosificación , AdsorciónRESUMEN
Despite the high mortality rate, sepsis lacks specific and effective treatment options. Conventional antibiotics, such as TIENAM (TIE; imipenem and cilastatin sodium for injection), face challenges owing to the emergence of bacterial resistance, which reduces their effectiveness and causes adverse effects. Addressing resistance and judicious drug use is crucial. Our research revealed that aloin (Alo) significantly boosts survival rates and reduces inflammation and bacterial load in mice with sepsis, demonstrating strong antimicrobial activity. Using a synergistic Alo + TIE regimen in a cecal ligation and puncture (CLP)-induced sepsis model, we observed a remarkable increase in survival rates from 10 % to 75 % within 72 h compared with the CLP group alone. This combination therapy also modulated inflammatory markers interleukin (IL)-6, IL-1ß, and tumor necrosis factor (TNF)-α, mitigated tissue damage, regulated immune cells by lowering NK, activated CD8+ and CD4+ T cells while increasing peritoneal macrophages, and decreased the bacterial load in the peritoneal cavity. We noted a significant shift in the abdominal cavity microbiota composition post-treatment, with a decrease in harmful bacteria, such as Lachnospiraceae_NK4A136_group, Klebsiella, Bacillus, and Escherichia, and an increase in beneficial bacteria, such as Lactobacillus and Mucispirillum. Our study emphasizes the efficacy of combining Alo with TIE to combat sepsis, and paves the way for further investigations and potential clinical applications aiming to overcome the limitations of TIE and enhance the therapeutic prospects of Alo.
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Ciego , Emodina , Ratones Endogámicos C57BL , Sepsis , Animales , Sepsis/tratamiento farmacológico , Sepsis/inmunología , Sepsis/microbiología , Emodina/farmacología , Emodina/uso terapéutico , Emodina/análogos & derivados , Ciego/cirugía , Ciego/microbiología , Ratones , Masculino , Ligadura , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , Punciones , Modelos Animales de Enfermedad , Imipenem/uso terapéutico , Imipenem/farmacología , Citocinas/metabolismo , Quimioterapia Combinada , Microbioma Gastrointestinal/efectos de los fármacos , Antiinflamatorios/uso terapéutico , Antiinflamatorios/farmacología , Inflamación/tratamiento farmacológico , Microbiota/efectos de los fármacos , Carga Bacteriana/efectos de los fármacosRESUMEN
AIMS: Adequately and accurately identifying carbapenemase-producing Enterobacterales (CPE) is vital for selecting appropriate antimicrobial therapy and implementing effective infection control measures. This study aims to optimize the phenotypic detection method of carbapenemase for routine diagnostics in clinical microbiology laboratories. METHODS AND RESULTS: Carbapenemase genes in 2665 non-duplicate CRE clinical strains collected from various regions of China were confirmed through whole-genome sequencing (WGS). The carbapenemase inhibition test (CIT) was conducted and interpreted using different methods and breakpoints, then compared with the NG-Test CARBA 5 for carbapenemase detection. The diagnostic performance of the CIT method was optimal when the carbapenemase types were determined by comparing the inhibition zone diameters of the imipenem disc with 3-aminophenylboronic acid (APB) plus ethylenediaminetetraacetic acid (EDTA) to those of the imipenem disc with either APB or EDTA alone, with a breakpoint of 4 mm. The overall sensitivities of the current CIT, the modified CIT, and NG-Test CARBA 5 were 91.4%, 94.9%, and 99.9%, respectively. For detecting isolates co-producing Klebsiella pneumoniae carbapenemase (KPC) and metallo-ß-lactamases (MBLs), the modified CIT method had higher sensitivity than the current method (70.0% vs. 53.3%), though this difference was not statistically significant (P = 0.063). The NG-Test CARBA 5 showed excellent performance for multi-carbapenemases diagnosis, with sensitivity and specificity of 97.1% and 100%, respectively. CONCLUSIONS: Optimizing and standardizing the CIT method for clinical use is necessary. It has certain advantages in diagnosing multi-carbapenemase and rare carbapenemase production. However, for identifying common carbapenemase types, the NG-Test CARBA 5 demonstrated superior performance.
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Proteínas Bacterianas , beta-Lactamasas , beta-Lactamasas/metabolismo , beta-Lactamasas/análisis , Proteínas Bacterianas/metabolismo , Humanos , China , Imipenem/farmacología , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Sensibilidad y Especificidad , Secuenciación Completa del Genoma , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/enzimología , Enterobacteriaceae/aislamiento & purificación , Infecciones por Enterobacteriaceae/microbiologíaRESUMEN
BACKGROUND: Novel beta-lactams show activity against many multidrug-resistant Gram-negative bacteria that cause severe lung infections. Understanding pharmacokinetic/pharmacodynamic characteristics of these agents may help optimise outcomes in the treatment of pneumonia. OBJECTIVES: To describe and appraise studies that report pulmonary pharmacokinetic and pharmacodynamic data of cefiderocol, ceftazidime/avibactam, ceftolozane/tazobactam, imipenem/cilastatin/relebactam and meropenem/vaborbactam. METHODS: MEDLINE (PubMed), Embase, Web of Science and Scopus libraries were used for the literature search. Pulmonary population pharmacokinetic and pharmacokinetic/pharmacodynamic studies on adult patients receiving cefiderocol, ceftazidime/avibactam, ceftolozane/tazobactam, imipenem/cilastatin/relebactam, and meropenem/vaborbactam published in peer-reviewed journals were included. Two independent authors screened, reviewed and extracted data from included articles. A reporting guideline for clinical pharmacokinetic studies (ClinPK statement) was used for bias assessment. Relevant outcomes were included, such as population pharmacokinetic parameters and probability of target attainment of dosing regimens. RESULTS: Twenty-four articles were included. There was heterogeneity in study methods and reporting of results, with diversity across studies in adhering to the ClinPK statement checklist. Ceftolozane/tazobactam was the most studied agent. Only two studies collected epithelial lining fluid samples from patients with pneumonia. All the other phase I studies enrolled healthy subjects. Significant population heterogeneity was evident among available population pharmacokinetic models. Probabilities of target attainment rates above 90% using current licensed dosing regiments were reported in most studies. CONCLUSIONS: Although lung pharmacokinetics was rarely described, this review observed high target attainment using plasma pharmacokinetic data for all novel beta-lactams. Future studies should describe lung pharmacokinetics in patient populations at risk of carbapenem-resistant pathogen infections.
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Antibacterianos , Cefalosporinas , Combinación de Medicamentos , Bacterias Gramnegativas , Inhibidores de beta-Lactamasas , beta-Lactamas , Humanos , Inhibidores de beta-Lactamasas/farmacocinética , Inhibidores de beta-Lactamasas/uso terapéutico , Inhibidores de beta-Lactamasas/farmacología , Antibacterianos/farmacocinética , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , beta-Lactamas/farmacocinética , beta-Lactamas/uso terapéutico , beta-Lactamas/farmacología , Cefalosporinas/farmacocinética , Cefalosporinas/uso terapéutico , Cefalosporinas/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Tazobactam/farmacocinética , Tazobactam/uso terapéutico , Tazobactam/farmacología , Neumonía Bacteriana/tratamiento farmacológico , Compuestos de Azabiciclo/farmacocinética , Compuestos de Azabiciclo/uso terapéutico , Compuestos de Azabiciclo/farmacología , Carbapenémicos/farmacocinética , Carbapenémicos/uso terapéutico , Carbapenémicos/farmacología , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Ceftazidima/farmacocinética , Ceftazidima/uso terapéutico , Cefiderocol , Meropenem/farmacocinética , Meropenem/uso terapéutico , Meropenem/farmacología , Imipenem/farmacocinética , Imipenem/uso terapéutico , Farmacorresistencia Bacteriana Múltiple , Pruebas de Sensibilidad Microbiana , Combinación Cilastatina e Imipenem/farmacocinética , Combinación Cilastatina e Imipenem/uso terapéutico , Ácidos Borónicos , Compuestos Heterocíclicos con 1 AnilloRESUMEN
BACKGROUND This study aimed to detect the volatile organic compound (VOC), 3-hydroxy-2-butanone (acetoin) using gas chromatography-ion mobility spectrometry (GC-IMS) in antimicrobial-resistant Klebsiella pneumoniae (K. pneumoniae) carbapenemase (KPC)-producing bacteria. MATERIAL AND METHODS Using stromal fluid of blood culture bottles (BacT/ALERT® SA) as the medium, 3-hydroxy-2-butanone (acetoin) released by K. pneumoniae during growth was detected using GC-IMS. The impact of imipenem (IPM) and carbapenemase inhibitors [avibactam sodium or pyridine-2,6-dicarboxylic acid (DPA)] on the emission of 3-hydroxy-2-butanone (acetoin) from various carbapenemase-producing K. pneumoniae was further investigated. Subsequently, VOCal software was used to generate a pseudo-3D plot of 3-hydroxy-2-butanone (acetoin), and the relative peak volumes were exported for data analysis. Standard strains served as references, and the findings were validated with clinical isolates. RESULTS The pattern of temporal changes in the 3-hydroxy-2-butanone (acetoin) release from K. pneumoniae in the absence of IPM was consistent with the growth curve. After the IPM addition, carbapenemase-positive strains released significantly higher contents of 3-hydroxy-2-butanone (acetoin) than carbapenemase-negative strains at the late exponential growth phase (T2). Notably, adding avibactam sodium significantly decreased the 3-hydroxy-2-butanone (acetoin) content released from the class A carbapenemase-producing strains as compared to the absence of the carbapenemase inhibitor. Conversely, adding DPA significantly decreased the 3-hydroxy-2-butanone (acetoin) content released from the class B carbapenemase-producing strains (both standard and clinical strains, all P<0.05). CONCLUSIONS This study demonstrated the potential of 3-hydroxy-2-butanone (acetoin) as a VOC biomarker for detecting carbapenemase-producing K. pneumoniae, as revealed by GC-IMS analysis.
Asunto(s)
Acetoína , Proteínas Bacterianas , Biomarcadores , Espectrometría de Movilidad Iónica , Klebsiella pneumoniae , beta-Lactamasas , Klebsiella pneumoniae/metabolismo , Klebsiella pneumoniae/efectos de los fármacos , Proteínas Bacterianas/metabolismo , beta-Lactamasas/metabolismo , Biomarcadores/metabolismo , Humanos , Acetoína/metabolismo , Espectrometría de Movilidad Iónica/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Imipenem/farmacología , Infecciones por Klebsiella/microbiología , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/metabolismo , Antibacterianos/farmacología , Compuestos de Azabiciclo/farmacologíaRESUMEN
Mycobacterium abscessus pulmonary infections are increasingly problematic, especially for immunocompromised individuals and those with underlying lung conditions. Currently, there is no reliable standardized treatment, underscoring the need for improved preclinical drug testing. We present a simplified immunosuppressed mouse model using only four injections of cyclophosphamide, which allows for sustained M. abscessus lung burden for up to 16 days. This model proved effective for antibiotic efficacy evaluation, as demonstrated with imipenem or amikacin.
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Amicacina , Antibacterianos , Ciclofosfamida , Modelos Animales de Enfermedad , Infecciones por Mycobacterium no Tuberculosas , Mycobacterium abscessus , Animales , Ciclofosfamida/farmacología , Mycobacterium abscessus/efectos de los fármacos , Ratones , Infecciones por Mycobacterium no Tuberculosas/tratamiento farmacológico , Infecciones por Mycobacterium no Tuberculosas/microbiología , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Amicacina/farmacología , Amicacina/uso terapéutico , Imipenem/farmacología , Imipenem/uso terapéutico , Pulmón/microbiología , Pulmón/efectos de los fármacos , Huésped Inmunocomprometido , FemeninoRESUMEN
The use of ß-lactam/ß-lactamase inhibitors constitutes an important strategy to counteract ß-lactamases in multidrug-resistant (MDR) Gram-negative bacteria. Recent reports have described ceftazidime-/avibactam-resistant isolates producing CTX-M variants with different amino acid substitutions (e.g., P167S, L169Q, and S130G). Relebactam (REL) combined with imipenem has proved very effective against Enterobacterales producing ESBLs, serine-carbapenemases, and AmpCs. Herein, we evaluated the inhibitory efficacy of REL against CTX-M-96, a CTX-M-15-type variant. The CTX-M-96 structure was obtained in complex with REL at 1.03 Å resolution (PDB 8EHH). REL was covalently bound to the S70-Oγ atom upon cleavage of the C7-N6 bond. Compared with apo CTX-M-96, binding of REL forces a slight displacement of the deacylating water inwards the active site (0.81 Å), making the E166 and N170 side chains shift to create a proper hydrogen bonding network. Binding of REL also disturbs the hydrophobic patch formed by Y105, P107, and Y129, likely due to the piperidine ring of REL that creates clashes with these residues. Also, a remarkable change in the positioning of the N104 sidechain is also affected by the piperidine ring. Therefore, differences in the kinetic behavior of REL against class A ß-lactamases seem to rely, at least in part, on differences in the residues being involved in the association and stabilization of the inhibitor before hydrolysis. Our data provide the biochemical and structural basis for REL effectiveness against CTX-M-producing Gram-negative pathogens and essential details for further DBO design. Imipenem/REL remains an important choice for dealing with isolates co-producing CTX-M with other ß-lactamases.
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Compuestos de Azabiciclo , Inhibidores de beta-Lactamasas , beta-Lactamasas , Compuestos de Azabiciclo/farmacología , Compuestos de Azabiciclo/química , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , beta-Lactamasas/química , Inhibidores de beta-Lactamasas/farmacología , Inhibidores de beta-Lactamasas/química , Cristalografía por Rayos X , Antibacterianos/farmacología , Imipenem/farmacología , Imipenem/química , Ceftazidima/farmacología , Pruebas de Sensibilidad Microbiana , Dominio CatalíticoRESUMEN
Treatment outcomes for Mycobacteroides abscessus (Mab, also known as Mycobacterium abscessus) disease are still unsatisfactory, mainly due to issues with drug toxicity, tolerability, and efficacy. Treating Mab disease is challenging due to its high baseline antibiotic resistance, initial requirement for intravenous therapy, and poor medication tolerance. Omadacycline, a new tetracycline, is active against Mab. Since any new antibiotic effective against Mab is expected to be used in combination with other antibiotics, we evaluated the efficacy of two triple-drug combinations comprising omadacycline, omadacycline + amikacin + imipenem, and omadacycline + clofazimine + linezolid against two contemporary Mab clinical isolates in a mouse model of Mab lung disease. Antibiotic administration was initiated 1-week post-infection and was given daily, with Mab burden in the lungs at treatment completion serving as the endpoint. Omadacycline alone moderately reduced Mab levels and maintained better health in mice compared to untreated ones, which typically suffered from the infection. The omadacycline + clofazimine + linezolid combination showed immediate bactericidal activity and enhanced efficacy over 6 weeks, particularly against the more resistant strain (M9507). However, the clofazimine + linezolid combination lacked early bactericidal activity. When combined with amikacin and imipenem, omadacycline did not improve the regimen's effectiveness over 4 weeks of treatment. Our study showed that omadacycline + clofazimine + linezolid exhibited significant bactericidal activity over an extended treatment duration. However, adding omadacycline to amikacin and imipenem did not improve regimen effectiveness against the evaluated clinical isolates within 4 weeks. Further research in Mab disease patients is needed to determine the most effective omadacycline-containing regimen.IMPORTANCEMycobacteroides abscessus is a common environmental bacterium that causes infections in people with compromised lung function, including those with bronchiectasis, cystic fibrosis, chronic obstructive pulmonary disease, and weakened immune systems, especially among older individuals. Treating M. abscessus disease is challenging due to the limited effectiveness and toxicity of current antibiotics, which often require prolonged use. Omadacycline, a new antibiotic, shows promise against M. abscessus. Using a mouse model that mimics M. abscessus disease in humans, we studied the effectiveness of including omadacycline with recommended antibiotics. Adding omadacycline to clofazimine and linezolid significantly improved treatment outcomes, rapidly clearing the bacteria from the lungs and maintaining effectiveness throughout. This oral combination is convenient for patients. However, adding omadacycline to amikacin and imipenem did not improve treatment effectiveness within 4 weeks. Further study with M. abscessus patients is necessary to optimize omadacycline-based treatment strategies for this disease.
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Amicacina , Antibacterianos , Clofazimina , Modelos Animales de Enfermedad , Quimioterapia Combinada , Imipenem , Linezolid , Infecciones por Mycobacterium no Tuberculosas , Mycobacterium abscessus , Tetraciclinas , Animales , Clofazimina/administración & dosificación , Clofazimina/uso terapéutico , Linezolid/administración & dosificación , Linezolid/uso terapéutico , Ratones , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Amicacina/administración & dosificación , Amicacina/uso terapéutico , Tetraciclinas/administración & dosificación , Tetraciclinas/uso terapéutico , Tetraciclinas/farmacología , Mycobacterium abscessus/efectos de los fármacos , Imipenem/administración & dosificación , Imipenem/uso terapéutico , Imipenem/farmacología , Infecciones por Mycobacterium no Tuberculosas/tratamiento farmacológico , Infecciones por Mycobacterium no Tuberculosas/microbiología , Femenino , Resultado del Tratamiento , Pruebas de Sensibilidad Microbiana , Enfermedades Pulmonares/tratamiento farmacológico , Enfermedades Pulmonares/microbiología , Administración Oral , Pulmón/microbiologíaRESUMEN
The Gram-negative ESKAPE bacterium Pseudomonas aeruginosa has become a pathogen of serious concern due its extensive multi-drug resistance (MDR) profile, widespread incidences of hospital-acquired infections throughout the United States, and high occurrence in wound infections suffered by warfighters serving abroad. Bacteriophage (phage) therapy has received renewed attention as an alternative therapeutic option against recalcitrant bacterial infections, both as multi-phage cocktails and in combination with antibiotics as synergistic pairings. Environmental screening and phage enrichment has yielded three lytic viruses capable of infecting the MDR P. aeruginosa strain PAO1. Co-administration of each phage with the carbapenem antibiotics ertapenem, imipenem, and meropenem generated enhanced overall killing of bacteria beyond either phage or drug treatments alone. A combination cocktail of all three phages was completely inhibitory to growth, even without antibiotics. The same 3× phage cocktail also disrupted PAO1 biofilms, reducing biomass by over 75% compared to untreated biofilms. Further, the phage cocktail demonstrated broad efficacy as well, capable of infecting 33 out of 100 diverse clinical isolate strains of P. aeruginosa. Together, these results indicate a promising approach for designing layered medical countermeasures to potentiate antibiotic activity and possibly overcome resistance against recalcitrant, MDR bacteria such as P. aeruginosa. Combination therapy, either by synergistic phage-antibiotic pairings, or by phage cocktails, presents a means of controlling mutations that can allow for bacteria to gain a competitive edge.
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Antibacterianos , Carbapenémicos , Farmacorresistencia Bacteriana Múltiple , Terapia de Fagos , Infecciones por Pseudomonas , Pseudomonas aeruginosa , Pseudomonas aeruginosa/virología , Pseudomonas aeruginosa/efectos de los fármacos , Carbapenémicos/farmacología , Antibacterianos/farmacología , Infecciones por Pseudomonas/terapia , Infecciones por Pseudomonas/microbiología , Biopelículas/efectos de los fármacos , Bacteriófagos/fisiología , Pruebas de Sensibilidad Microbiana , Humanos , Fagos Pseudomonas/fisiología , Imipenem/farmacologíaRESUMEN
Characterizing the physiological response of bacterial cells to antibiotics is crucial for designing diagnostic techniques, treatment choices, and drug development. While bacterial cells at sublethal doses of antibiotics are commonly characterized, the impact of exposure to high concentrations of antibiotics on bacteria after long-term serial exposure and their effect on withdrawal need attention for further characterization. This study investigated the effect of increasing imipenem concentrations on carbapenem-susceptible (S) and carbapenem-resistant (R) E. coli on their growth adaptation and cell surface structure. We exposed the bacterial population to increasing imipenem concentrations through 30 exposure cycles. Cell morphology was observed using a 3D laser scanning confocal microscope (LSCM) and transmission electron microscope (TEM). Results showed that the exposure resulted in significant morphological changes in E. coli (S) cells, while minor changes were seen in E. coli (R) cells. The rod-shaped E. coli (S) gradually transformed into round shapes. Further, the exposed E. coli (S) cells' surface area-to-volume ratio (SA/V) was also significantly different from the control, which is non-exposed E. coli (S). Then, the exposed E. coli (S) cells were re-grown in antibiotic-free environment for 100 growth cycles to determine if the changes in cells were reversible. The results showed that their cell morphology remained round, showing that the cell morphology was not reversible. The morphological response of these cells to imipenem can assist in understanding the resistance mechanism in the context of diagnostics and antibacterial therapies.
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Antibacterianos , Carbapenémicos , Escherichia coli , Imipenem , Pruebas de Sensibilidad Microbiana , Escherichia coli/efectos de los fármacos , Antibacterianos/farmacología , Imipenem/farmacología , Carbapenémicos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Microscopía Electrónica de Transmisión , Biomarcadores , Microscopía ConfocalRESUMEN
Pseudomonas aeruginosa is one of the most important nosocomial pathogens that possess the ability to produce multiple antibiotic resistance and virulence factors. Elastase B (LasB) is the major factor implicated in tissue invasion and damage during P. aeruginosa infections, whose synthesis is regulated by the quorum sensing (QS) system. Anti-virulence approach is now considered as potential therapeutic alternative and/or adjuvant to current antibiotics' failure. The aim of this study is primarily to find out the impact of the efflux pump inhibitor (EPI) phenylalanine arginyl ß-naphthylamide (PAßN) on the production of elastase B and the gene expression of lasI quorum sensing and lasB virulence factor in clinical isolates of P. aeruginosa. Five P. aeruginosa isolates recovered from patients with respiratory tract infections were examined in this study. Antimicrobial susceptibility of isolates was performed by the disk agar diffusion method. Effect of the PAßN on imipenem susceptibility, bacterial viability, and elastase production was evaluated. The expression of lasB and lasI genes was measured by quantitative real-time PCR in the presence of PAßN. All isolates were identified as multidrug-resistant (MDR) and showed resistance to carbapenem (MIC = 64-256 µg/mL). Susceptibility of isolates to imipenem was highly increased in the presence of efflux inhibitor. PAßN significantly reduced elastase activity in three isolates tested without affecting bacterial growth. In addition, the relative expression of both lasB and lasI genes was diminished in all isolates in the presence of inhibitor. Efflux inhibition by using the EPI PAßN could be a potential target for controlling the P. aeruginosa virulence and pathogenesis. Furthermore, impairment of drug efflux by PAßN indicates its capability to be used as antimicrobial adjuvant that can decrease the resistance and lower the effective doses of current drugs.
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Antibacterianos , Proteínas Bacterianas , Dipéptidos , Imipenem , Pruebas de Sensibilidad Microbiana , Elastasa Pancreática , Infecciones por Pseudomonas , Pseudomonas aeruginosa , Percepción de Quorum , Factores de Virulencia , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/aislamiento & purificación , Percepción de Quorum/efectos de los fármacos , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Elastasa Pancreática/genética , Elastasa Pancreática/metabolismo , Antibacterianos/farmacología , Humanos , Infecciones por Pseudomonas/microbiología , Dipéptidos/farmacología , Imipenem/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Farmacorresistencia Bacteriana , MetaloendopeptidasasRESUMEN
INTRODUCTION: Novel beta-lactam/beta-lactamase inhibitor (BIBLI) combinations are commercially available and have been used for treating carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. Continuous surveillance of susceptibility profiles and resistance mechanism identification are necessary to monitor the evolution of resistance within these agents. OBJECTIVE: The purpose of this study was to evaluate the susceptibility rates of ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam in CRKP isolated from patients with bloodstream infections who underwent screening for a randomized clinical trial in Brazil. METHODS: Minimum inhibitory concentrations (MICs) were determined for meropenem, ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam using the gradient diffusion strip method. Carbapenemase genes were detected by multiplex real-time polymerase chain reaction. Klebsiella pneumoniae carbapenemase (KPC)-producing isolates showing resistance to any BLBLI and New Delhi Metallo-beta-lactamase (NDM)-producing isolates with susceptibility to any BLBLI isolates were further submitted for whole-genome sequencing. RESULTS: From a total of 69 CRKP isolates, 39 were positive for blaKPC, 19 for blaNDM and 11 for blaKPC and blaNDM. KPC-producing isolates demonstrated susceptibility rates above 94â¯% for all BLBLIs. Two isolates with resistance to meropenem/vaborbactam demonstrated a Gly and Asp duplication at the porin OmpK36 as well as a truncated OmpK35. All NDM-producing isolates, including KPC and NDM coproducers, demonstrated susceptibility rates to ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam of 0â¯%, 9.1-21.1â¯% and 9.1-26.3â¯%, respectively. Five NDM-producing isolates that presented susceptibility to BLBLIs also had porin alterations CONCLUSIONS: This study showed that, although high susceptibility rates to BLBLIs were found, KPC-2 isolates were able to demonstrate resistance probably as a result of porin mutations. Additionally, NDM-1 isolates showed susceptibility to BLBLIs in vitro.
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Antibacterianos , Compuestos de Azabiciclo , Enterobacteriaceae Resistentes a los Carbapenémicos , Ceftazidima , Combinación de Medicamentos , Infecciones por Klebsiella , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana , Inhibidores de beta-Lactamasas , beta-Lactamasas , Humanos , Brasil , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/aislamiento & purificación , Inhibidores de beta-Lactamasas/farmacología , Infecciones por Klebsiella/microbiología , Compuestos de Azabiciclo/farmacología , Ceftazidima/farmacología , beta-Lactamasas/genética , Antibacterianos/farmacología , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Proteínas Bacterianas/genética , Meropenem/farmacología , Imipenem/farmacología , Bacteriemia/microbiología , Ácidos Borónicos/farmacología , Compuestos Heterocíclicos con 1 AnilloRESUMEN
Prompt and precise identification of carbapenemase-producing organisms is crucial for guiding clinical antibiotic treatments and limiting transmission. Here, we propose modifying the Blue Carba test (BCT) and Carba NP-direct (CNPd) to identify molecular carbapenemase classes, including dual carbapenemase strains, by adding specific Class A and Class B inhibitors. We tested 171 carbapenemase-producing Gram-negative bacilli strains-21 in Class A (KPC, NMC, SME), 58 in Class B (IMP, VIM, NDM, SPM), and 92 with dual carbapenemase production (KPC+NDM, KPC+IMP, KPC+VIM), all previously positive with BCT or CNPd. We also included 13 carbapenemase non-producers. ß-lactamases were previously characterized by PCR. The improved BCT/CNPd methods detect imipenem hydrolysis from an imipenem-cilastatin solution, using pH indicators and Class A (avibactam) and/or Class B (EDTA) inhibitors. Results were interpreted visually based on color changes. CNPd achieved 99.4% sensitivity and 100% specificity in categorizing carbapenemases, while BCT had 91.8% sensitivity and 100% specificity. Performance varied by carbapenemase classes: both tests classified all Class A-producing strains. For Class B, the CNP test identified 57/58 strains (98.3%), whereas the BCT test, 45/58 strains (77.6%), with non-fermenters posing the greatest detection challenge. For Classes A plus B dual producers, both tests performed exceptionally well, with only one indeterminate strain for the BCT. The statistical comparison showed both methods had similar times to a positive result, with differences based on the carbapenemase class or bacterial group involved. This improved assay rapidly distinguishes major Class A or Class B carbapenemase producers among Gram-negative bacilli, including dual-class combinations, in less than 2 hours. IMPORTANCE: Rapid and accurate identification of carbapenemase-producing organisms is of vital importance in guiding appropriate clinical antibiotic treatments and curbing their transmission. The emergence of negative bacilli carrying multiple carbapenemase combinations during and after the severe acute respiratory syndrome coronavirus 2 pandemic has posed a challenge to the conventional biochemical tests typically used to determine the specific carbapenemase type in the isolated strains. Several initiatives have aimed to enhance colorimetric methods, enabling them to independently identify the presence of Class A or Class B carbapenemases. Notably, no previous efforts have been made to distinguish both classes simultaneously. Additionally, these modifications have struggled to differentiate between carriers of multiple carbapenemases, a common occurrence in many Latin American countries. In this study, we introduced specific Class A and Class B carbapenemase inhibitors into the Blue Carba test (BCT) and Carba NP-direct (CNP) colorimetric assays to identify the type of carbapenemase, even in cases of multiple carbapenemase producers within these classes. These updated assays demonstrated exceptional sensitivity and specificity (≥ 90%) all within a rapid turnaround time of under 2 hours, typically completed in just 45 minutes. These in-house enhancements to the BCT and CNP assays present a rapid, straightforward, and cost-effective approach to determining the primary carbapenemase classes. They could serve as a viable alternative to molecular biology or immuno-chromatography techniques, acting as an initial diagnostic step in the process.
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Antibacterianos , Proteínas Bacterianas , Bacterias Gramnegativas , Pruebas de Sensibilidad Microbiana , beta-Lactamasas , beta-Lactamasas/análisis , beta-Lactamasas/metabolismo , Proteínas Bacterianas/metabolismo , Bacterias Gramnegativas/enzimología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/clasificación , Humanos , Antibacterianos/farmacología , Sensibilidad y Especificidad , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Gramnegativas/diagnóstico , Imipenem/farmacologíaRESUMEN
BACKGROUND: Elizabethkingia spp. are emerging as nosocomial pathogens causing various infections. These pathogens express resistance to a broad range of antibiotics, thus requiring antimicrobial combinations for coverage. However, possible antagonistic interactions between antibiotics have not been thoroughly explored. This study aimed to evaluate the effectiveness of antimicrobial combinations against Elizabethkingia infections, focusing on their impact on pathogenicity, including biofilm production and cell adhesion. METHODS: Double-disc diffusion, time-kill, and chequerboard assays were used for evaluating the combination effects of antibiotics against Elizabethkingia spp. We further examined the antagonistic effects of antibiotic combinations on biofilm formation and adherence to A549 human respiratory epithelial cells. Further validation of the antibiotic interactions and their implications was performed using ex vivo hamster precision-cut lung sections (PCLSs) to mimic in vivo conditions. RESULTS: Antagonistic effects were observed between cefoxitin, imipenem and amoxicillin/clavulanic acid in combination with vancomycin. The antagonism of imipenem toward vancomycin was specific to its effects on the genus Elizabethkingia. Imipenem further hampered the bactericidal effect of vancomycin and impaired its inhibition of biofilm formation and the adhesion of Elizabethkingia meningoseptica ATCC 13253 to human cells. In the ex vivo PCLS model, vancomycin exhibited dose-dependent bactericidal effects; however, the addition of imipenem also reduced the effect of vancomycin. CONCLUSIONS: Imipenem reduced the bactericidal efficacy of vancomycin against Elizabethkingia spp. and compromised its capacity to inhibit biofilm formation, thereby enhancing bacterial adhesion. Clinicians should be aware of the potential issues with the use of these antibiotic combinations when treating Elizabethkingia infections.
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Antibacterianos , Biopelículas , Infecciones por Flavobacteriaceae , Imipenem , Pruebas de Sensibilidad Microbiana , Vancomicina , Animales , Imipenem/farmacología , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Humanos , Vancomicina/farmacología , Infecciones por Flavobacteriaceae/microbiología , Infecciones por Flavobacteriaceae/tratamiento farmacológico , Flavobacteriaceae/efectos de los fármacos , Adhesión Bacteriana/efectos de los fármacos , Células A549 , Cricetinae , Interacciones Farmacológicas , Pulmón/microbiologíaRESUMEN
Rhodococcus hoagii is a gram positive actinomycete found in horses and cattle. Humans can be infected by ingestion or inhalation through contaminated food or soil. The organism usually infects immunosuppressed hosts with pneumonia being the common presentation. We present a case of an 89 years old, apparently immunocompetent host presenting with fever, encephalopathy and arthritis who grew Rhodococcus hoagii in blood and synovial fluid, The patient responded well to a combination of vancomycin, azithromycin and imipenem-cilastatin. Our case demonstrates that extra-pulmonary manifestations such as septic arthritis and bacteremia can be seen in immune competent hosts.
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Infecciones por Actinomycetales , Antibacterianos , Artritis Infecciosa , Bacteriemia , Humanos , Artritis Infecciosa/microbiología , Artritis Infecciosa/tratamiento farmacológico , Artritis Infecciosa/diagnóstico , Bacteriemia/microbiología , Bacteriemia/tratamiento farmacológico , Bacteriemia/diagnóstico , Masculino , Antibacterianos/uso terapéutico , Anciano de 80 o más Años , Infecciones por Actinomycetales/microbiología , Infecciones por Actinomycetales/tratamiento farmacológico , Infecciones por Actinomycetales/diagnóstico , Vancomicina/uso terapéutico , Imipenem/uso terapéutico , Cilastatina/uso terapéutico , Azitromicina/uso terapéutico , Líquido Sinovial/microbiología , Combinación Cilastatina e Imipenem/uso terapéutico , Resultado del Tratamiento , Sangre/microbiologíaRESUMEN
OBJECTIVES: Mycobacterium abscessus complex (MABC) is the most common rapidly growing Mycobacterium species in structural pulmonary diseases and can be life-threatening. This study aimed to assess the clinical characteristics and drug-susceptibility statuses of different M. abscessus (MAB) subspecies in the Zhejiang Province. METHODS: DNA sequencing was used to differentiate clinical MABC subspecies isolates. The Clinical and Laboratory Standards Institute guidelines were used to determine in vitro susceptibility of imipenem-relebactam (IMP-REL), omadacycline, and other conventional antibiotics. Patient clinical characteristics were collected and analysed. RESULTS: In total, 139 M. abscessus, 39 Mycobacterium massiliense, and 1 Mycobacterium bolletii isolates were collected, accounting for 77.7%, 21.8%, and 0.5% of the MABC isolates, respectively. Patients with M. abscessus pulmonary disease (M.ab-PD) had higher proportions of older adults, tuberculosis history, chronic pulmonary disease, and malignancy than those with M. massiliense pulmonary disease (M.ma-PD). Patients with M.ab-PD had higher rates of bilateral middle- and lower-lobe involvement than patients with M.ma-PD. Both subspecies showed high resistance rates to doxycycline and moxifloxacin, and clarithromycin-induced resistance was more common in M.ab than in M.ma. IMP-REL resulted in a twofold reduction in the minimum inhibitory concentration (MIC) value compared with imipenem alone among MAB; furthermore, the MIC was lower in M.ab than in M.ma. Omadacycline and tigecycline had comparable in vitro susceptibility, and the MIC showed no statistically significant difference between M.ab and M.ma. CONCLUSIONS: M.ab is the most prevalent MABC subspecies in the Zhejiang Province. Patients with M.ab-PD have complex underlying diseases and broader lobar lesions. IMP-REL and omadacycline are promising antibiotics for MABC infection treatment.
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Antibacterianos , Pruebas de Sensibilidad Microbiana , Infecciones por Mycobacterium no Tuberculosas , Mycobacterium abscessus , Humanos , Mycobacterium abscessus/efectos de los fármacos , Mycobacterium abscessus/aislamiento & purificación , Mycobacterium abscessus/genética , Mycobacterium abscessus/clasificación , Antibacterianos/farmacología , Infecciones por Mycobacterium no Tuberculosas/microbiología , Infecciones por Mycobacterium no Tuberculosas/tratamiento farmacológico , Persona de Mediana Edad , Femenino , Masculino , Anciano , China , Adulto , Imipenem/farmacología , Enfermedades Pulmonares/microbiología , Enfermedades Pulmonares/tratamiento farmacológicoRESUMEN
OBJECTIVES: Acinetobacter pittii has emerged as an opportunistic nosocomial pathogen associated with hospital-acquired infections. The purpose of this study was to investigate the genetic structures of plasmids carrying carbapenemase genes blaOXA-58 and blaOXA-72 in A. pittii strains AR3676 and AR3651 isolated from patients. METHODS: Antimicrobial susceptibility testing was performed using broth microdilution. Whole-genome sequencing and bioinformatics analysis were performed to characterize the genome of A. pittii AR3676 and AR3651. Conjugation experiments were conducted to evaluate plasmid transferability. Phylogenetic and comparative genomic analysis were performed to explore the characteristics of carbapenem-resistant A. pittii isolates worldwide. RESULTS: The AR3676 strain showed resistance to imipenem. The 19 700-bp plasmid pAR3676-OXA-58 harboured blaOXA-58 with genetic contexts consisting of a truncated ISAba3-like-blaOXA58-ISAba3. Additionally, the AR3651 strain showed resistance to imipenem and meropenem. The AR3651 genome comprised one 9,837-bp RepA_AB plasmid pAR3651-OXA-72 harbouring blaOXA-72. This blaOXA-72 was flanked by XerC/XerD recombination sites. The conjugation of plasmids pAR3676-OXA-58 and pAR3651-OXA-72 from A. pittii to Acinetobacter baumannii ATCC 17978RIFR failed three independent times. Phylogenetic analysis of A. pittii strains AR3676, AR3651, and a further 504 A. pittii strains collected between 1966 and 2022 from various geographic localities revealed genetic diversity with a heterogeneous distribution of carbapenemase genes. CONCLUSIONS: A. pittii strains with a plasmid carrying blaOXA-58 or blaOXA-72 may serve as an important reservoir of carbapenemase genes. Carbapenemase genes on a single plasmid may facilitate their dissemination and persistence. Additionally, pdif sites and mobile elements play an important role in the mobilization of resistance genes and plasmid evolution.
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Infecciones por Acinetobacter , Acinetobacter , Antibacterianos , Proteínas Bacterianas , Pruebas de Sensibilidad Microbiana , Filogenia , Plásmidos , Secuenciación Completa del Genoma , beta-Lactamasas , Plásmidos/genética , beta-Lactamasas/genética , China , Humanos , Acinetobacter/genética , Acinetobacter/efectos de los fármacos , Acinetobacter/enzimología , Acinetobacter/aislamiento & purificación , Infecciones por Acinetobacter/microbiología , Proteínas Bacterianas/genética , Antibacterianos/farmacología , Imipenem/farmacología , Genoma BacterianoRESUMEN
OBJECTIVES: The treatment options available for infections caused by multidrug-resistant Gram-negative pathogens are often limited. Cefiderocol (CFDC) is a novel siderophore cephalosporin that exhibits activity against these pathogens. Several studies have reported the in vitro activity of CFDC against isolates from Europe, the United States, and China, but the activity against carbapenem-resistant bacteria with IMP-type carbapenemase has not been extensively studied. We, therefore, studied the in vitro activities of CFDC against carbapenem-resistant bacteria with available genomic backgrounds based on whole-genome sequencing (WGS) in Japan, where the IMP-type is the predominant carbapenemase produced by Gram-negative rods. METHODS: We selected 603 isolates (528 Enterobacterales, 18 Pseudomonas aeruginosa, and 57 Acinetobacter spp.) from a collection of Gram-negative clinical isolates collected during a Japan Antimicrobial Resistance Bacterial Surveillance program and evaluated the antimicrobial activities of CFDC, ceftolozane/tazobactam (CTLZ/TAZ), imipenem-relebactam (IPM/REL), and ceftazidime/avibactam (CAZ/AVI) against carbapenemase-producing Enterobacterales, carbapenemase-non-producing meropenem-non-susceptible Enterobacterales, and carbapenemase-producing nonfermentative bacteria. RESULTS: Among these, 97.7% of carbapenemase-producing Enterobacterales (99.2% of IMP-type carbapenemase-producing Enterobacterales), 100% of carbapenemase-producing P. aeruginosa, and 91.2% of carbapenemase-producing Acinetobacter spp. were susceptible to CFDC, showing better antimicrobial activity than the other antimicrobial agents evaluated in this study. CFDC was highly effective against class A-, B-, and D ß-lactamase-harbouring isolates when compared to the other antimicrobial agents. In addition, the relationship between CFDC resistance and three genetic factors involved in resistance was discussed. CONCLUSIONS: This is the first large-scale study to systematically demonstrate the efficacy of CFDC against IMP-type carbapenemase-producing strains with known genomic backgrounds.
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Acinetobacter , Antibacterianos , Proteínas Bacterianas , Cefiderocol , Cefalosporinas , Bacterias Gramnegativas , Meropenem , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa , Secuenciación Completa del Genoma , beta-Lactamasas , beta-Lactamasas/genética , beta-Lactamasas/metabolismo , Cefalosporinas/farmacología , Japón , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Antibacterianos/farmacología , Meropenem/farmacología , Humanos , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/enzimología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/genética , Bacterias Gramnegativas/enzimología , Acinetobacter/efectos de los fármacos , Acinetobacter/genética , Acinetobacter/aislamiento & purificación , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Bacterias Gramnegativas/microbiología , Compuestos de Azabiciclo/farmacología , Tazobactam/farmacología , Combinación de Medicamentos , Imipenem/farmacología , Ceftazidima/farmacología , Monitoreo EpidemiológicoRESUMEN
Sepsis is a systemic inflammatory response syndrome caused by the invasion of pathogenic microorganisms. Despite major advances in diagnosis and technology, morbidity and mortality remain high. The level of neutrophil extracellular traps (NETs) is closely associated with the progression and prognosis of sepsis, suggesting the regulation of NET formation as a new strategy in sepsis treatment. Owing to its pleiotropic effects, atorvastatin, a clinical lipid-lowering drug, affects various aspects of sepsis-related inflammation and immune responses. To align closely with clinical practice, we combined it with imipenem for the treatment of sepsis. In this study, we used a cecum ligation and puncture-induced lung injury mouse model and employed techniques including western blot, immunofluorescence, and enzyme-linked immunosorbent assay to measure the levels of NETs and other sepsis-related lung injury indicators. Our findings indicate that atorvastatin effectively inhibited the formation of NETs. When combined with imipenem, it significantly alleviated lung injury, reduced systemic inflammation, and improved the 7-day survival rate of septic mice. Additionally, we explored the inhibitory mechanism of atorvastatin on NET formation in vitro, revealing its potential action through the ERK/NOX2 pathway. Therefore, atorvastatin is a potential immunomodulatory agent that may offer new treatment strategies for patients with sepsis in clinical settings.