RESUMO
BACKGROUND: The optimal administration of polymyxins for treating multidrug-resistant gram-negative bacterial (MDR-GNB) pneumonia remains unclear. This study aimed to systematically assess the efficacy and safety of three polymyxin-containing regimens by conducting a comprehensive network meta-analysis. METHODS: We comprehensively searched nine databases. Overall mortality was the primary outcome, whereas the secondary outcomes encompassed microbial eradication rate, clinical success, acute kidney injury, and incidence of bronchospasm. Extracted study data were analyzed by pairwise and network meta-analyses. Version 2 of the Cochrane risk-of-bias tool and the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) assessment tool were used to assess the risk of bias in randomized trials and cohort studies, respectively. RESULTS: This study included 19 observational studies and 3 randomized controlled trials (RCTs), encompassing 3318 patients. Six studies with high risk of bias were excluded from the primary analysis. In the pairwise meta-analysis, compared to the intravenous (IV) polymyxin-containing regimen, the intravenous plus inhaled (IV + IH) polymyxin-containing regimen showed a significant decrease in overall mortality, while no statistically significant difference was found in the inhaled (IH) polymyxin-containing regimen. The network meta-analysis indicated that the IV + IH polymyxin-containing regimen had significantly lower overall mortality (OR 0.67; 95% confidence interval [CI] 0.50-0.88), higher clinical success rate (OR 1.90; 95% CI 1.20-3.00), better microbial eradication rate (OR 2.70; 95% CI 1.90-3.90) than the IV polymyxin-containing regimen, and significantly better microbial eradication rate when compared with the IH polymyxin-containing regimen (OR 2.30; 95% CI 1.30-4.20). Furthermore, compared with IV + IH and IV polymyxin-containing regimens, the IH polymyxin-containing regimen showed a significant reduction in acute kidney injury. CONCLUSIONS: Our study indicates that among the three administration regimens, the IV + IH polymyxin-containing regimen may be the most effective for treating MDR-GNB pneumonia, with a significantly lower overall mortality compared to the IV regimen and a considerably higher microbial eradication rate compared to the IH regimen. The IH regimen may be considered superior to the IV regimen due to its substantially lower incidence of acute kidney injury, even though the reduction in overall mortality was not significant.
Assuntos
Antibacterianos , Farmacorresistência Bacteriana Múltipla , Infecções por Bactérias Gram-Negativas , Polimixinas , Humanos , Antibacterianos/uso terapêutico , Antibacterianos/administração & dosagem , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/mortalidade , Metanálise em Rede , Polimixinas/uso terapêutico , Polimixinas/administração & dosagemRESUMO
Patients with severe carbapenem-resistant Acinetobacter baumannii (CRAB) infections currently face significant treatment challenges. When patients display signs of infection and the clinical suspicion of CRAB infections is high, appropriate treatment should be immediately provided. However, current treatment plans and clinical data for CRAB are limited. Inherent and acquired resistance mechanisms, as well as host factors, significantly restrict options for empirical medication. Moreover, inappropriate drug coverage can have detrimental effects on patients. Most existing studies have limitations, such as a restricted sample size, and are predominantly observational or non-randomized, which report significant variability in patient infection severity and comorbidities. Therefore, a gold-standard therapy remains lacking. Current and future treatment options of infections due to CRAB were described in this review. The dose and considerable side effects restrict treatment options for polymyxins, and high doses of ampicillin-sulbactam or tigecycline appear to be the best option at the time of initial treatment. Moreover, new drugs such as durlobactam and cefiderocol have substantial therapeutic capabilities and may be effective salvage treatments. Bacteriophages and antimicrobial peptides may serve as alternative treatment options in the near future. The advantages of a combination antimicrobial regimen appear to predominate those of a single regimen. Despite its significant nephrotoxicity, colistin is considered a primary treatment and is often used in combination with antimicrobials, such as tigecycline, ampicillin-sulbactam, meropenem, or fosfomycin. The Infectious Diseases Society of America (IDSA) has deemed high-dose ampicillin-sulbactam, which is typically combined with high-dose tigecycline, polymyxin, and other antibacterial agents, the best option for treating serious CRAB infections. A rational combination of drug use and the exploration of new therapeutic drugs can alleviate or prevent the effects of CRAB infections, shorten hospital stays, and reduce patient mortality.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Antibacterianos , Carbapenêmicos , Acinetobacter baumannii/efeitos dos fármacos , Humanos , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , Carbapenêmicos/uso terapêutico , Carbapenêmicos/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Quimioterapia Combinada , Resistência beta-Lactâmica , Polimixinas/uso terapêutico , Polimixinas/farmacologia , Farmacorresistência Bacteriana MúltiplaAssuntos
Aminoglicosídeos , Antibacterianos , Ventriculite Cerebral , Farmacorresistência Bacteriana Múltipla , Infecções por Bactérias Gram-Negativas , Injeções Espinhais , Meningites Bacterianas , Polimixinas , Humanos , Antibacterianos/uso terapêutico , Antibacterianos/administração & dosagem , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Ventriculite Cerebral/tratamento farmacológico , Ventriculite Cerebral/microbiologia , Resultado do Tratamento , Polimixinas/uso terapêutico , Polimixinas/administração & dosagem , Meningites Bacterianas/tratamento farmacológico , Meningites Bacterianas/microbiologia , Aminoglicosídeos/uso terapêutico , Aminoglicosídeos/administração & dosagem , Bactérias Gram-Negativas/efeitos dos fármacos , beta-Lactamas/uso terapêutico , beta-Lactamas/administração & dosagem , Inibidores de beta-Lactamases/uso terapêutico , Inibidores de beta-Lactamases/administração & dosagemRESUMO
BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a substantial healthcare challenge. This study assessed the in vitro efficacy of selected antibiotic combinations against CRKP infections. METHODS: Our research involved the evaluation of 40 clinical isolates of CRKP, with half expressing Klebsiella pneumoniae carbapenemase (KPC) and half producing Metallo-ß-lactamase (MBL), two key enzymes contributing to carbapenem resistance. We determined the minimum inhibitory concentrations (MICs) of four antibiotics: eravacycline, tigecycline, polymyxin-B, and ceftazidime/avibactam. Synergistic interactions between these antibiotic combinations were examined using checkerboard and time-kill analyses. RESULTS: We noted significant differences in the MICs of ceftazidime/avibactam between KPC and MBL isolates. Checkerboard analysis revealed appreciable synergy between combinations of tigecycline (35%) or eravacycline (40%) with polymyxin-B. The synergy rates for the combination of tigecycline or eravacycline with polymyxin-B were similar among the KPC and MBL isolates. These combinations maintained a synergy rate of 70.6% even against polymyxin-B resistant isolates. In contrast, combinations of tigecycline (5%) or eravacycline (10%) with ceftazidime/avibactam showed significantly lower synergy than combinations with polymyxin-B (P < 0.001 and P = 0.002, respectively). Among the MBL CRKP isolates, only one exhibited synergy with eravacycline or tigecycline and ceftazidime/avibactam combinations, and no synergistic activity was identified in the time-kill analysis for these combinations. The combination of eravacycline and polymyxin-B demonstrated the most promising synergy in the time-kill analysis. CONCLUSION: This study provides substantial evidence of a significant synergy when combining tigecycline or eravacycline with polymyxin-B against CRKP strains, including those producing MBL. These results highlight potential therapeutic strategies against CRKP infections.
Assuntos
Compostos Azabicíclicos , Proteínas de Bactérias , Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Klebsiella , Tetraciclinas , Humanos , Ceftazidima/uso terapêutico , Tigeciclina/farmacologia , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Klebsiella pneumoniae , Infecções por Klebsiella/tratamento farmacológico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , beta-Lactamases/farmacologia , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Testes de Sensibilidade MicrobianaRESUMO
INTRODUCTION: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections commonly cause hospital-acquired infections. The study aimed to compare the outcomes of CRKP infections between patients receiving ceftazidime avibactam +/- aztreonam and polymyxins in a hospital setting with a high prevalence of New Delhi Metallo Beta Lactamase production. METHODS: We conducted a retrospective cohort study from January 2020 to September 2022 in critically ill adult patients admitted to a non-COVID-19 medical intensive care unit with CRKP infection. The patients were followed up for a total of 30 days or death, whichever was later. RESULTS: Of a total of 106 patients included in the study, 65 patients received polymyxins and 41 patients received ceftazidime-avibactam +/- aztreonam. Higher 30-day mortality was noted in the polymyxin group (56.9% vs. 29.2%, P = 0.005). The mean time to event (mortality) in ceftazidime-avibactam +/- aztreonam was 23.9 + 1.5 days which was significantly higher compared to polymyxins (17.9 + 1.2 days, p = 0.006). On Cox regression analysis, after adjusting for the covariates, the hazard ratio for time to event with the use of polymyxin was 2.02 (95% CI: 1.03-3.9). CONCLUSION: Ceftazidime-avibactam + aztreonam is possibly associated with better clinical outcomes in patients infected with CRKP.
Assuntos
Compostos Azabicíclicos , Infecção Hospitalar , Infecções por Klebsiella , Adulto , Humanos , Ceftazidima/uso terapêutico , Aztreonam/uso terapêutico , Antibacterianos/uso terapêutico , Klebsiella pneumoniae , Polimixinas/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Estudos Retrospectivos , Combinação de Medicamentos , beta-Lactamases , Carbapenêmicos , Testes de Sensibilidade Microbiana , Infecções por Klebsiella/tratamento farmacológicoRESUMO
OBJECTIVE: Carbapenem-resistant Enterobacteriaceae (CRE) pose a significant threat to human health and have emerged as a major public health concern. We aimed to compare the efficacy and the safety of ceftazidime-avibactam (CAZ-AVI) and polymyxin in the treatment of CRE infections. METHODS: A systematic review and meta-analysis was performed by searching the databases of EMBASE, PubMed, and the Cochrane Library. Published studies on the use of CAZ-AVI and polymyxin in the treatment of CRE infections were collected from the inception of the database until March 2023. Two investigators independently screened the literature according to the inclusion and exclusion criteria, evaluated the methodological quality of the included studies and extracted the data. The meta-analysis was performed using RevMan 5.4 software. RESULTS: Ten articles with 833 patients were included (CAZ-AVI 325 patients vs Polymyxin 508 patients). Compared with the patients who received polymyxin-based therapy, the patients who received CAZ-AVI therapy had significantly lower 30-days mortality (RR = 0.49; 95% CI 0.01-2.34; I2 = 22%; P < 0.00001), higher clinical cure rate (RR = 2.70; 95% CI 1.67-4.38; I2 = 40%; P < 0.00001), and higher microbial clearance rate (RR = 2.70; 95% CI 2.09-3.49; I2 = 0%; P < 0.00001). However, there was no statistically difference in the incidence of acute kidney injury between patients who received CAZ-AVI and polymyxin therapy (RR = 1.38; 95% CI 0.69-2.77; I2 = 22%; P = 0.36). In addition, among patients with CRE bloodstream infection, those who received CAZ-AVI therapy had significantly lower mortality than those who received polymyxin therapy (RR = 0.44; 95% CI 0.27-0.69, I2 = 26%, P < 0.00004). CONCLUSIONS: Compared to polymyxin, CAZ-AVI demonstrated superior clinical efficacy in the treatment of CRE infections, suggesting that CAZ-AVI may be a superior option for CRE infections.
Assuntos
Compostos Azabicíclicos , Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Enterobacteriaceae , Humanos , Antibacterianos/uso terapêutico , Polimixinas/uso terapêutico , Infecções por Enterobacteriaceae/tratamento farmacológico , Testes de Sensibilidade Microbiana , Ceftazidima/uso terapêutico , Combinação de MedicamentosRESUMO
IMPORTANCE: This study provides insights into the mechanisms of polymyxin resistance in K. pneumoniae clinical isolates and demonstrates potential strategies of polymyxin and vancomycin combinations for combating this resistance. We also identified possible mechanisms that might be associated with the treatment of these combinations against carbapenem- and polymyxin-resistant K. pneumoniae clinical isolates. The findings have significant implications for the development of alternative therapies and the effective management of infections caused by these pathogens.
Assuntos
Infecções por Klebsiella , Polimixinas , Humanos , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Vancomicina/farmacologia , Vancomicina/uso terapêutico , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Infecções por Klebsiella/tratamento farmacológicoRESUMO
Polymyxin antibiotics are the last resort for treating patients in intensive care units infected with multiple-resistant Gram-negative bacteria. Due to their polycationic structure, their mode of action is based on an ionic interaction with the negatively charged lipid A portion of the lipopolysaccharide (LPS). The most prevalent polymyxin resistance mechanisms involve covalent modifications of lipid A: addition of the cationic sugar 4-amino-L-arabinose (L-Ara4N) and/or phosphoethanolamine (pEtN). The modified structure of lipid A has a lower net negative charge, leading to the repulsion of polymyxins and bacterial resistance to membrane disruption. Genes encoding the enzymatic systems involved in these modifications can be transferred either through chromosomes or mobile genetic elements. Therefore, new approaches to resistance diagnostics have been developed. On another note, interfering with these enzymatic systems might offer new therapeutic targets for drug discovery. This literature review focuses on diagnostic approaches based on structural changes in lipid A and on the therapeutic potential of molecules interfering with these changes.
Assuntos
Lipopolissacarídeos , Polimixinas , Humanos , Polimixinas/uso terapêutico , Polimixinas/farmacologia , Lipopolissacarídeos/química , Lipídeo A/química , Farmacorresistência Bacteriana/genética , Antibacterianos/uso terapêutico , Antibacterianos/farmacologiaRESUMO
In recent years, the detection rate of multidrug-resistant and pandrug-resistant Klebsiella pneumoniae has increased year on year, so polymyxin has received increasing attention as an antibiotic that is still sensitive to most of the multidrug-resistant strains. However, widespread use of polymyxin is likely to lead to the emergence of polymyxin-resistant Klebsiella pneumoniae. At the same time, the polymyxin hetero-resistance has made clinical prevention and treatment difficult. In addition to relying on the combination of polymyxins with other antibiotics, the search for new antibacterial drugs has also become a research hotspot. Research into early detection methods for polymyxin resistance can also help to optimize and improve the diagnosis and treatment strategies. This article reviewed the epidemic status, mechanism, detection methods and prevention measures of polymyxin-resistant Klebsiella pneumoniae.
Assuntos
Infecções por Klebsiella , Polimixinas , Humanos , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Polimixina B/farmacologia , Polimixina B/uso terapêutico , Klebsiella pneumoniae , Farmacorresistência Bacteriana Múltipla , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Testes de Sensibilidade Microbiana , Infecções por Klebsiella/diagnóstico , Infecções por Klebsiella/tratamento farmacológicoRESUMO
BACKGROUND: Our aim in this retrospective cohort study was to assess the impact on mortality of the empirical use of polymyxin as therapy for carbapenem-resistant gram-negative bacteria (CR-GNB) in septic patients. The study was performed at a tertiary academic hospital in Brazil, from January 2018 to January 2020, the pre-coronavirus disease 2019 period. METHODS: We included 203 patients with suspected sepsis. The first doses of antibiotics were prescribed from a "sepsis antibiotic kit", which contained a selection of drugs, including polymyxin, with no preapproval policy. We developed a logistic regression model to assess risk factors associated with 14-day crude mortality. Propensity score for polymyxin was used to control biases. RESULTS: Seventy (34%) of 203 patients had infections with at least 1 multidrug-resistant organism isolated from any clinical culture. Polymyxins in monotherapy or in combination therapy were prescribed to 140 of the 203 (69%) patients. The overall 14-day mortality rate was 30%. The 14-day crude mortality was associated with age (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 1.01-1.05; P = .01), SOFA (sepsis-related organ failure assessment) score value (aOR, 1.2; 95% CI, 1.09-1.32; P < .001), CR-GNB infection (aOR, 3.94; 95% CI, 1.53-10.14; P = .005), and time between suspected sepsis and antibiotic administration (aOR, 0.73; 95% CI, .65-.83; P < .001). The empirical use of polymyxins was not associated with decreased crude mortality (aOR, 0.71; 95% CI, .29-1.71; P = .44). CONCLUSIONS: Empirical use of polymyxin for septic patients in a setting with high CR-GNB prevalence was not associated with decreased crude mortality.
Assuntos
COVID-19 , Infecções por Bactérias Gram-Negativas , Sepse , Humanos , Polimixinas/uso terapêutico , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Estudos Retrospectivos , Antibacterianos/uso terapêutico , Bactérias Gram-Negativas , Sepse/tratamento farmacológico , Sepse/epidemiologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologiaRESUMO
The emergence and spread of multidrug-resistant (MDR) Klebsiella pneumoniae strains have increased worldwide, posing a significant health threat by limiting the therapeutic options. This study aimed to investigate the antimicrobial potential of cinnamaldehyde against MDR-K. pneumoniae strains in vitro and in vivo assays. The presence of resistant genes in MDR- K. pneumoniae strains were evaluated by Polymerase Chain Reaction (PCR) and DNA sequencing. Carbapenem-resistant K. pneumoniae strains show the blaKPC-2 gene, while polymyxin-resistant K. pneumoniae presented blaKPC-2 and alterations in the mgrB gene. Cinnamaldehyde exhibited an inhibitory effect against all MDR- K. pneumoniae evaluated. An infected mice model was used to determine the in vivo effects against two K. pneumoniae strains, one carbapenem-resistant and another polymyxin-resistant. After 24 h of cinnamaldehyde treatment, the bacterial load in blood and peritoneal fluids decreased. Cinnamaldehyde showed potential effectiveness as an antibacterial agent by inhibiting the growth of MDR-K. pneumoniae strains.
Assuntos
Anti-Infecciosos , Infecções por Klebsiella , Camundongos , Animais , Klebsiella pneumoniae/genética , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Infecciosos/farmacologia , Carbapenêmicos/farmacologia , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Testes de Sensibilidade MicrobianaRESUMO
Klebsiella pneumoniae, a pathogen of critical clinical concern, urgently demands effective therapeutic options owing to its drug resistance. Polymyxins are increasingly regarded as a last-line therapeutic option for the treatment of multidrug-resistant (MDR) Gram-negative bacterial infections. However, polymyxin resistance in K. pneumoniae is an emerging issue. Here, we report that gallium nitrate (GaNt), an antimicrobial candidate, exhibits a potentiating effect on colistin against MDR K. pneumoniae clinical isolates. To further confirm this, we investigated the efficacy of combined GaNt and colistin in vitro using spot dilution and rapid time-kill assays and growth curve inhibition tests and in vivo using a murine lung infection model. The results showed that GaNt significantly increased the antimicrobial activity of colistin, especially in the iron-limiting media. Mechanistic studies demonstrated that bacterial antioxidant activity was repressed by GaNt, as revealed by RNA sequencing (RNA-seq), leading to intracellular accumulation of reactive oxygen species (ROS) in K. pneumoniae, which was enhanced in the presence of colistin. Therefore, oxidative stress induced by GaNt and colistin augments the colistin-mediated killing of wild-type cells, which can be abolished by dimethyl sulfoxide (DMSO), an effective ROS scavenger. Collectively, our study indicates that GaNt has a notable impact on the antimicrobial activity of colistin against K. pneumoniae, revealing the potential of GaNt as a novel colistin adjuvant to improve the treatment outcomes of bacterial infections. IMPORTANCE This study aimed to determine the antimicrobial activity of GaNt combined with colistin against Klebsiella pneumoniae in vitro and in vivo. Our results suggest that by combining GaNt with colistin, antioxidant activity was suppressed and reactive oxygen species accumulation was induced in bacterial cells, enhancing antimicrobial activity against K. pneumoniae. We found that GaNt functioned as an antibiotic adjuvant when combined with colistin by inhibiting the growth of multidrug-resistant K. pneumoniae. Our study provides insight into the use of an adjuvant to boost the antibiotic potential of colistin for treating infections caused by multidrug-resistant K. pneumoniae.
Assuntos
Anti-Infecciosos , Infecções por Klebsiella , Camundongos , Animais , Colistina/farmacologia , Klebsiella pneumoniae/genética , Espécies Reativas de Oxigênio , Antioxidantes/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Infecciosos/farmacologia , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Testes de Sensibilidade Microbiana , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Farmacorresistência Bacteriana MúltiplaRESUMO
Acinetobacter baumannii infection presents a high mortality rate and few therapeutic options. This study aimed to evaluate clinical-microbiological characteristics and prognosis factors of patients diagnosed with A. baumanni. infections treated with oral doxycycline. A retrospective cohort of hospitalized patients with confirmed Acinetobacter spp. infection between 2018 and 2020 receives at least 3 days of oral doxycycline. Clinical and microbiological data were evaluated, including the outcome and molecular characterization of A. baumannii. Doxycycline minimal inhibitory concentrations were evaluated by the broth dilution method. One hundred patients were included with a median age of 51 years. The leading site of infection was pulmonary (n = 62), followed by the soft tissues and skin (n = 28). A. baumannii resistant to carbapenem was found on 94%. The gene blaOXA-23 and blaOXA-51 were amplified in all recovered isolates of A. baumannii (n = 44). Doxycycline MIC50 and MIC90 were 1 µg/mL and 2 µg/mL, respectively. Death rate at 14 days and 28 days of follow-up was 9% and 14%, respectively. The prognostic factors related to death at end of follow-up were age > 49 years [85.7% vs. 46%, CI 95% 6.9 (1.4-32.6), P = 0.015] and hemodialysis [28.6% vs. 7%, CI 95% 5.33 (1.2-22.1), P = 0.021]. Patients treated with doxycycline to A. baumannii presented a relatively low death rate, and risk factors related to death were age and hemodialysis. Further and larger studies should compare polymyxin to doxycycline to better understand the differences between these therapeutic options.
Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Humanos , Pessoa de Meia-Idade , Doxiciclina/farmacologia , Doxiciclina/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Polimixinas/uso terapêutico , Estudos Retrospectivos , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Testes de Sensibilidade Microbiana , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/microbiologia , beta-Lactamases/genéticaRESUMO
Treating multidrug-resistant infections has increasingly relied on last-resort antibiotics, including polymyxins, for example colistin. As polymyxins are given routinely, the prevalence of their resistance is on the rise and increases mortality rates of sepsis patients. The global dissemination of plasmid-borne colistin resistance, driven by the emergence of mcr-1, threatens to diminish the therapeutic utility of polymyxins from an already shrinking antibiotic arsenal. Restoring sensitivity to polymyxins using combination therapy with sensitizing drugs is a promising approach to reviving its clinical utility. Here we describe the ability of the biotin biosynthesis inhibitor, MAC13772, to synergize with colistin exclusively against colistin-resistant bacteria. MAC13772 indirectly disrupts fatty acid synthesis (FAS) and restores sensitivity to the last-resort antibiotic, colistin. Accordingly, we found that combinations of colistin and other FAS inhibitors, cerulenin, triclosan and Debio1452-NH3, had broad potential against both chromosomal and plasmid-mediated colistin resistance in chequerboard and lysis assays. Furthermore, combination therapy with colistin and the clinically relevant FabI inhibitor, Debio1452-NH3, showed efficacy against mcr-1 positive Klebsiella pneumoniae and colistin-resistant Escherichia coli systemic infections in mice. Using chemical genomics, lipidomics and transcriptomics, we explored the mechanism of the interaction. We propose that inhibiting FAS restores colistin sensitivity by depleting lipid synthesis, leading to changes in phospholipid composition. In all, this work reveals a surprising link between FAS and colistin resistance.
Assuntos
Colistina , Infecções por Escherichia coli , Animais , Camundongos , Colistina/farmacologia , Colistina/uso terapêutico , Farmacorresistência Bacteriana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Infecções por Escherichia coli/microbiologia , Ácidos Graxos/farmacologiaRESUMO
BACKGROUND: With the difficulties in choosing colistin sulfate and polymyxin B sulfate (PBS) for carbapenem-resistant gram-negative bacteria (CR-GNB), we compared the efficacy and safety of these two old polymyxins in treatment of critically ill patients infected with CR-GNB infection. METHODS: One hundred four patients infected with CR-GNB in ICU were retrospectively grouped by PBS (68 patients) or colistin sulfate (36 patients). Clinical efficacy including symptoms, inflammatory parameters, defervescence, prognosis and microbial efficacy were analyzed. Hepatotoxicity, nephrotoxicity, and hematotoxicity were evaluated by TBiL, ALT, AST, creatinine, and thrombocytes. RESULTS: Demographic characteristics between colistin sulfate and PBS were not significantly different. Most of the CR-GNB were cultured in respiratory tract (91.7% vs 86.8%), and almost all were polymyxin-sensitive (98.2% vs 100%, MIC ≤ 2 µg/ml). The microbial efficacy in colistin sulfate (57.1%) was significantly higher than PBS (30.8%) (p = 0.022), however, no significant difference in clinical success was seen in both groups (33.8% vs 41.7%), as well as mortality, defervescence, imaging remission, days in the hospital, microbial reinfections, and prognosis, and almost all patients defervesce within 7 days (95.6% vs 89.5%). CONCLUSIONS: Both polymyxins can be administrated in critically ill patients infected with CR-GNB and colistin sulfate is superior to PBS in microbial clearance. These results highlight the necessity of identifying CR-GNB patients who may benefit from polymyxin and who are at higher risk of mortality.
Assuntos
Colistina , Infecções por Bactérias Gram-Negativas , Humanos , Colistina/efeitos adversos , Polimixina B/efeitos adversos , Antibacterianos/uso terapêutico , Carbapenêmicos/uso terapêutico , Estudos Retrospectivos , Estado Terminal , Bactérias Gram-Negativas , Polimixinas/uso terapêutico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologiaRESUMO
Polymyxin-carbapenem-resistant Klebsiella pneumoniae (PCR-Kp) with pan (PDR)- or extensively drug-resistant phenotypes has been increasingly described worldwide. Here, we report a PCR-Kp outbreak causing untreatable infections descriptively correlated with bacterial genomes. Hospital-wide surveillance of PCR-Kp was initiated in December-2014, after the first detection of a K. pneumoniae phenotype initially classified as PDR, recovered from close spatiotemporal cases of a sentinel hospital in Rio de Janeiro. Whole-genome sequencing of clinical PCR-Kp was performed to investigate similarities and dissimilarities in phylogeny, resistance and virulence genes, plasmid structures and genetic polymorphisms. A target phenotypic profile was detected in 10% (12/117) of the tested K. pneumoniae complex bacteria recovered from patients (8.5%, 8/94) who had epidemiological links and were involved in intractable infections and death, with combined therapeutic drugs failing to meet synergy. Two resistant bacterial clades belong to the same transmission cluster (ST437) or might have different sources (ST11). The severity of infection was likely related to patients' comorbidities, lack of antimicrobial therapy and predicted bacterial genes related to high resistance, survival, and proliferation. This report contributes to the actual knowledge about the natural history of PCR-Kp infection, while reporting from a time when there were no licensed drugs in the world to treat some of these infections. More studies comparing clinical findings with bacterial genetic markers during clonal spread are needed.
Assuntos
Infecções por Klebsiella , Polimixinas , Humanos , Polimixinas/farmacologia , Polimixinas/uso terapêutico , Klebsiella pneumoniae , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/genética , Brasil , Genoma Bacteriano , Surtos de Doenças , Carbapenêmicos/uso terapêutico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Testes de Sensibilidade Microbiana , beta-Lactamases/genética , Proteínas de Bactérias/genéticaRESUMO
Infection with P. aeruginosa, one of the most relevant opportunistic pathogens in hospital-acquired infections, can lead to high mortality due to its low antibiotic susceptibility to limited choices of antibiotics. Polymyxin as last-resort antibiotics is used in the treatment of systemic infections caused by multidrug-resistant P. aeruginosa strains, so studying the emergence of polymyxin-resistant was a must. The present study was designed to define genomic differences between paired polymyxin-susceptible and polymyxin-resistant P. aeruginosa strains and established polymyxin resistance mechanisms, and common chromosomal mutations that may confer polymyxin resistance were characterized. A total of 116 CRPA clinical isolates from patients were collected from three tertiary care hospitals in China during 2017-2021. Our study found that polymyxin B resistance represented 3.45% of the isolated carbapenem-resistant P. aeruginosa (CRPA). No polymyxin-resistant isolates were positive for mcr (1-8 and 10) gene and efflux mechanisms. Key genetic variations identified in polymyxin-resistant isolates involved missense mutations in parR, parS, pmrB, pmrA, and phoP. The waaL and PA5005 substitutions related to LPS synthesis were detected in the highest levels of resistant strain (R1). The missense mutations H398R in ParS (4/4), Y345H in PmrB (4/4), and L71R in PmrA (3/4) were the predominant. Results of the PCR further confirmed that mutation of pmrA, pmrB, and phoP individually or simultaneously did affect the expression level of resistant populations and can directly increase the expression of arnBCADTEF operon to contribute to polymyxin resistance. In addition, we reported 3 novel mutations in PA1945 (2129872_A < G, 2130270_A < C, 2130272_T < G) that may confer polymyxin resistance in P. aeruginosa. Our findings enriched the spectrum of chromosomal mutations, highlighted the complexity at the molecular level, and multifaceted interplay mechanisms underlying polymyxin resistance in P. aeruginosa.
Assuntos
Polimixinas , Infecções por Pseudomonas , Humanos , Polimixinas/farmacologia , Polimixinas/metabolismo , Polimixinas/uso terapêutico , Pseudomonas aeruginosa , Farmacorresistência Bacteriana/genética , Proteínas de Bactérias/genética , Antibacterianos/uso terapêutico , Carbapenêmicos/farmacologia , Genômica , Testes de Sensibilidade Microbiana , Infecções por Pseudomonas/microbiologiaRESUMO
The incidence of infections caused by resistant Gram-negative pathogens has become a critical factor in public health due to the limitation of therapeutic options for the control of infections caused, especially, by Enterobacteriaceae (Escherichia coli and Klebsiella pneumoniae), Pseudomonas spp., and Acinetobacter spp. Thus, given the increase in resistant pathogens and the reduction of therapeutic options, polymyxins were reintroduced into the clinic. As the last treatment option, polymyxins were regarded as the therapeutic key, since they were one of the few classes of antimicrobials that had activity against multidrug-resistant Gram-negative bacilli. Nonetheless, over the years, the frequent use of this antimicrobial has led to reports of resistance cases. In 2015, mcr (mobile colistin resistance), a colistin resistance gene, was described in China. Due to its location on carrier plasmids, this gene is characterized by rapid spread through conjugation. It has thus been classified as a rising threat to public health worldwide. In conclusion, based on several reports that show the emergence of mcr in different regional and climatic contexts and species of isolates, this work aims to review the literature on the incidence of the mcr gene in Brazil in different regions, types of samples identified, species of isolates, and type of carrier plasmid.
Assuntos
Colistina , Proteínas de Escherichia coli , Colistina/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Brasil/epidemiologia , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Polimixinas/uso terapêutico , Proteínas de Escherichia coli/genética , Plasmídeos/genética , Testes de Sensibilidade MicrobianaRESUMO
This study was aimed at investigating risk factors for mortality in patients suffering from KPC-producing Klebsiella pneumoniae (KPC-Kp) bloodstream infections (BSIs), evaluating the impact of rapid diagnostics and ceftazidime/avibactam use. This observational retrospective study (January 2017-May 2021) included all patients with a KPC-Kp BSI. Uni-multivariable analyses were carried out to evaluate the effect of clinical variables on both in-hospital death (IHD) and 30-day all-cause mortality, and the role of the combination of ceftazidime/avibactam plus polymyxin. One hundred and ninety-six patients met the study's inclusion criteria. Older age, having undergone renal replacement therapy during the 30 days preceding the KPC-Kp BSI onset, having an INCREMENT-CPE score ≥ 8, and having suffered from a superimposed and/or following KPC-Kp BSI treatment candidemia were found to be the main factors associated with both mortality rates. Among protective factors, the centrality of ceftazidime/avibactam in monotherapy (IHD: OR: 0.34; CI 95%: 0.11-1.00-30-day all-cause mortality: OR: 0.18; CI 95%: 0.04-0.77) or combination (IHD: OR: 0.51; CI 95%: 0.22-1.19-30-day all-cause mortality: OR: 0.62; CI 95%: 0.21-1.84) emerged and became even more evident once the effect of ceftazidime/avibactam plus polymyxin was removed. Rapid diagnostics may be useful to adopt more effective strategies for the treatment of KPC-Kp BSI patients and implement infection control measures, even if not associated with higher patient survival. Ceftazidime/avibactam, even when used alone, represents an important option against KPC-Kp, while combined use with polymyxin might not have altered its efficacy. Patient comorbidities, severity of BSI, and complications such as candidemia were confirmed to have a significant burden on survival.
Assuntos
Candidemia , Infecções por Klebsiella , Humanos , Ceftazidima/uso terapêutico , Ceftazidima/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Klebsiella pneumoniae , Estudos Retrospectivos , Testes de Diagnóstico Rápido , Candidemia/tratamento farmacológico , Mortalidade Hospitalar , Infecções por Klebsiella/diagnóstico , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , beta-Lactamases , Combinação de Medicamentos , Polimixinas/uso terapêutico , Polimixinas/farmacologia , Proteínas de Bactérias , Testes de Sensibilidade MicrobianaRESUMO
Polymyxins are a class of antibiotics that were discovered in 1947 from programs searching for compounds effective in the treatment of Gram-negative infections. Produced by the Gram-positive bacterium Paenibacillus polymyxa and composed of a cyclic peptide chain with a peptide-fatty acyl tail, polymyxins exert bactericidal effects through membrane disruption. Currently, polymyxin B and colistin (polymyxin E) have been developed for clinical use, where they are reserved as "last-line" therapies for multidrug-resistant (MDR) infections. Unfortunately, the incidences of strains resistant to polymyxins have been increasing globally, and polymyxin heteroresistance has been gaining appreciation as an important clinical challenge. These phenomena, along with bacterial tolerance to this antibiotic class, constitute important contributors to polymyxin treatment failure. Here, we review polymyxins and their mechanism of action, summarize the current understanding of how polymyxin treatment fails, and discuss how the next generation of polymyxins holds promise to invigorate this antibiotic class.