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1.
Microbiol Spectr ; 10(2): e0223521, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35416695

RESUMO

Relebactam is a novel ß-lactamase inhibitor of Ambler class A and C ß-lactamases that has been developed in combination with imipenem/cilastatin for the treatment of carbapenem-resistant bacterial infections. In this study, we evaluated the in vitro antibacterial activity of imipenem/relebactam (IMR) against imipenem-nonsusceptible Enterobacterales and Pseudomonas aeruginosa isolates from Japan. Two sets of antibacterial susceptibility tests were conducted according to the susceptibility testing standard of the Clinical and Laboratory Standards Institute. In the first set, antibacterial susceptibility as measured by the MIC50/90 (MIC range) of IMR was assessed for the following 61 imipenem-nonsusceptible strains: 2 Enterobacter cloacae complex (not determined [0.25 µg/mL]), 33 Klebsiella aerogenes (0.5/1 µg/mL [0.5 to 1 µg/mL]), 2 Serratia marcescens (not determined [1 to 2 µg/mL]), and 24 P. aeruginosa (2/128 µg/mL [0.25 to >128 µg/mL]). In the second set, antibacterial susceptibility was assessed for the following 8 imipenem-nonsusceptible strains: 4 Escherichia coli, 1 E. cloacae complex and 3 Klebsiella pneumoniae. The MIC ranges of IMR for these strains were 0.25 to 0.5 µg/mL, 0.5 µg/mL, and 0.5 to 16 µg/mL, respectively. The antibacterial activity of IMR was similar to or lower than that of amikacin and comparable to or greater than those of other reference drugs. In conclusion, IMR has shown antibacterial activity against clinical isolates from Japan and, therefore, is expected to become a new therapeutic option for carbapenem-resistant infections in Japan. IMPORTANCE Carbapenem-resistant Enterobacterales and carbapenem-resistant Pseudomonas aeruginosa strains pose a global threat. Antibacterial activity of imipenem/relebactam (IMR) against clinical isolates of these bacteria from several global regions has been shown; however, as yet there are no reports on Japanese isolates. In this study, we evaluated the in vitro antibacterial activity of IMR against imipenem-nonsusceptible Enterobacterales and Pseudomonas aeruginosa isolates from Japan. The antibacterial activity of IMR against imipenem-nonsusceptible Enterobacterales was generally comparable to that of amikacin (AMK) and comparable to or higher than those of other reference drugs tested. The antibacterial activity of IMR against imipenem-nonsusceptible P. aeruginosa isolates was lower than that of AMK but comparable to or higher than those of other drugs. These results support the use of IMR as a new treatment option for infections due to Enterobacterales and P. aeruginosa strains that are resistant to existing ß-lactams and other antibacterial agents.


Assuntos
Amicacina , Imipenem , Amicacina/farmacologia , Antibacterianos/farmacologia , Compostos Azabicíclicos , Carbapenêmicos , Imipenem/farmacologia , Japão , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa
2.
Rev Esp Quimioter ; 35 Suppl 1: 46-49, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35488826

RESUMO

Imipenem combined with beta-lactamase inhibitor relebactam (IMI/REL) has an extensive bactericidal activity against Gram-negative pathogens producing class A or class C beta-lactamases, not active against class B and class D. The phase 3 clinical trial (RESTORE-IMI-2), double-blind, randomized, evaluated IMI/REL vs. piperacillin-tazobactam (PIP/TAZ) for treatment of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), demonstrated non-inferiority at all-cause mortality at 28 days (15.9% vs 21.3%), favorable clinical response at 7-14 days end of treatment (61% vs 59.8%) and with minor serious adverse effects (26.7% vs 32%). IMI/REL is a therapeutic option in HAP and VAP at approved dosage imipenem 500 mg, cilastatin 500 mg and relebactam 250 mg once every 6h, by an IV infusion over 30 min.


Assuntos
Antibacterianos , Quimioterapia Combinada , Pneumonia Associada à Ventilação Mecânica , Antibacterianos/uso terapêutico , Compostos Azabicíclicos/uso terapêutico , Cilastatina/uso terapêutico , Ensaios Clínicos Fase III como Assunto , Quimioterapia Combinada/efeitos adversos , Humanos , Imipenem/uso terapêutico , Gravidade do Paciente , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , Ensaios Clínicos Controlados Aleatórios como Assunto
3.
Rev Assoc Med Bras (1992) ; 68(3): 395-399, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35442370

RESUMO

OBJECTIVE: The aim of this study was to explore the efficacy of imipenem combined with glutamine in the treatment of severe acute pancreatitis with abdominal infection in mainland China using meta-analysis. METHODS: We searched China National Knowledge Network, Wanfang Medical Network, Chinese Science Citation Database, PubMed, and Embase Databases for publications of imipenem combined with glutamine in the treatment of severe acute pancreatitis abdominal infection. The search time limit was from the establishment of the database to April 10, 2021. Stata software version 12.0 was used for statistical analysis; the combined effect size odds ratio and standardized mean difference values were calculated for the count data and measurement data, respectively; and the heterogeneity test was performed in this study. RESULTS: A total of five randomized controlled trials were included. A total of 499 cases were included, with 251 in the observation group and 248 in the control group. Meta-analysis results showed that the efficacy of imipenem combined with glutamine in the treatment of severe acute pancreatitis with abdominal infection was significantly better than that of imipenem alone (odds ratio=0.78, 95%CI 0.71-0.86, p=0.040). CONCLUSION: Imipenem combined with glutamine can significantly improve the efficacy in the treatment of severe acute pancreatitis with abdominal cavity infection.


Assuntos
Glutamina , Pancreatite , Doença Aguda , China , Glutamina/uso terapêutico , Humanos , Imipenem/uso terapêutico , Pancreatite/tratamento farmacológico
4.
BMC Infect Dis ; 22(1): 385, 2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35436875

RESUMO

BACKGROUND: Since the available data for bloodstream infections in solid malignancy tumors are somewhat limited in Palestine, prevention of infection before the occurrence, controlling it when it occurs, and implementing stewardship programs are important ways in the whole therapy of solid tumor patients, which is becoming challenging recently with the evolution of more antimicrobial drug-resistant pathogens. Therefore, our study aims to assess the microbial spectrum and antimicrobial sensitivity and the overall outcome related to many clinical risk factors in patients with solid tumor patients seeking care in a referral hospital as an experience from a developing country. METHODS: From the onset of 2018 to the end of 2020, a total of 116 episodes with positive blood cultures were retrospectively studied and analyzed in 96 patients who had solid tumors in a referral hospital in Palestine. RESULTS: We identified 116 positive blood cultures in 96 patients with a male to female ratio of 1:1. The mean age was 58 years. Breast cancer was the tumor most frequently recorded (13.5%), followed by urinary tract tumors (10.4%). The most common source of episodes with positive blood culture was catheter-related. Gram-positive bacteria accounted for 52.6% of blood cultures with the predomination of Staphylococcus species. On the contrary, Gram-negative bacteria were documented in 39.7% of the cultures, with E. coli being the most frequent bacteria. Regarding fungi that were only Candida species, it was isolated in 15.5% of the cultures.28.4% of patients started on a single antimicrobial as an initial regimen, the remaining started combination antimicrobial therapy. The initial antimicrobials used most frequently were aminoglycosides in 29.3% of the episodes. All species of Staphylococcus were sensitive to vancomycin. Enterococcus species were fully resistant to ciprofloxacin. In the case of E. coli, the isolates were 100% sensitive to imipenem, meropenem, and amikacin and were mostly resistant to ampicillin, where the sensitivity was only about 19.5%. P.aeruginosa was sensitive in 83.3% of cultures to both piperacillin-tazobactam and gentamicin, but highly resistant to imipenem, in which sensitivity decreased to 50%. The isolates of Klebsiella species were 72.2% sensitive to gentamicin, meropenem, and imipenem and 100% resistant to ampicillin. A. baumannii was 50% sensitive to trimethoprim-sulfamethoxazole. Candida species showed high sensitivity to both caspofungin and flucytosine (83.3%), followed by 77.8% sensitivity to voriconazole. Death was reported in 27.6% of the episodes and there was a significant relationship between shock at presentation and death (p = 0.010). CONCLUSIONS: The findings of this investigation confirm the prevalent BSI seen in patients with solid malignancies and demonstrate a significant percentage of antibiotic resistance. Therefore, stewardship programs that dig deep before using any type of antimicrobials will help reduce the risk of resistance to antibiotics. In addition, the implementation of infection control surveillance plays an important role in decreasing the risk of contamination.


Assuntos
Escherichia coli , Neoplasias , Ampicilina , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Resistência a Medicamentos , Farmacorresistência Bacteriana , Feminino , Gentamicinas , Bactérias Gram-Negativas , Humanos , Imipenem , Masculino , Meropeném , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Estudos Retrospectivos , Staphylococcus , Centros de Atenção Terciária
5.
Diagn Microbiol Infect Dis ; 103(2): 115674, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35398608

RESUMO

OBJECTIVE: The objective of this study was to evaluate the in vitro activity of aztreonam plus imipenem-relebactam against clinical and isogenic strains of Escherichia coli and Klebsiella pneumoniae co-harboring NDM and >1 serine ß-lactamase. METHODS: Thirteen isolates were included: 4 clinical E. coli, 4 clinical K. pneumoniae, and 5 isogenic E. coli. Drugs were tested in time-kill analyses alone, in dual ß-lactam combinations, and in triple drug combinations against all strains. RESULTS: All isolates were resistant to imipenem and imipenem-relebactam, and 85% were aztreonam-resistant. Neither imipenem nor imipenem-relebactam was bactericidal alone while aztreonam was bactericidal against 54% of isolates. The combination of aztreonam+imipenem was bactericidal and synergistic against 7/13 and 10/13 isolates. The addition of relebactam to this combination resulted in synergy against all 11 aztreonam-resistant clinical isolates. CONCLUSION: Aztreonam plus imipenem-relebactam may be a viable treatment option for aztreonam-non-susceptible NDM and serine ß-lactamase-producing E. coli and K. pneumoniae.


Assuntos
Aztreonam , beta-Lactamases , Antibacterianos/farmacologia , Compostos Azabicíclicos/farmacologia , Aztreonam/farmacologia , Escherichia coli , Humanos , Imipenem/farmacologia , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Serina
6.
Sci Rep ; 12(1): 5140, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35332241

RESUMO

We aim to assess the antibacterial and anti-biofilm properties of Niosome-encapsulated Imipenem. After isolating Staphylococcus epidermidis isolates and determining their microbial sensitivity, their ability to form biofilms was examined using plate microtiter assay. Various formulations of Niosome-encapsulated Imipenem were prepared using the thin-film hydration method, Minimum Biofilm Inhibitory Concentration (MBIC) and Minimum Inhibitory Concentration (MIC) were determined, and biofilm genes expression was examined. Drug formulations' toxicity effect on HDF cells were determined using MTT assay. Out of the 162 separated S. epidermidis, 106 were resistant to methicillin. 87 MRSE isolates were vancomycin-resistant, all of which could form biofilms. The F1 formulation of niosomal Imipenem with a size of 192.3 ± 5.84 and an encapsulation index of 79.36 ± 1.14 was detected, which prevented biofilm growth with a BGI index of 69% and reduced icaD, FnbA, EbpS biofilms' expression with P ≤ 0.001 in addition to reducing MBIC and MIC by 4-6 times. Interestingly, F1 formulation of niosomal Imipenem indicated cell viability over 90% at all tested concentrations. The results of the present study indicate that Niosome-encapsulated Imipenem reduces the resistance of MRSE to antibiotics in addition to increasing its anti-biofilm and antibiotic activity, and could prove useful as a new strategy for drug delivery.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Antibacterianos/farmacologia , Biofilmes , Imipenem/farmacologia , Lipossomos/farmacologia , Resistência a Meticilina , Testes de Sensibilidade Microbiana , Prevalência , Staphylococcus epidermidis
7.
Drugs ; 82(5): 533-557, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35294769

RESUMO

Sulopenem (formerly known as CP-70,429, and CP-65,207 when a component of a racemic mixture with its R isomer) is an intravenous and oral penem that possesses in vitro activity against fluoroquinolone-resistant, extended spectrum ß-lactamases (ESBL)-producing, multidrug-resistant (MDR) Enterobacterales. Sulopenem is being developed to treat patients with uncomplicated and complicated urinary tract infections (UTIs) as well as intra-abdominal infections. This review will focus mainly on its use in UTIs. The chemical structure of sulopenem shares properties of penicillins, cephalosporins, and carbapenems. Sulopenem is available as an oral prodrug formulation, sulopenem etzadroxil, which is hydrolyzed by intestinal esterases, resulting in active sulopenem. In early studies, the S isomer of CP-65,207, later developed as sulopenem, demonstrated greater absorption, higher drug concentrations in the urine, and increased stability against the renal enzyme dehydropeptidase-1 compared with the R isomer, which set the stage for its further development as a UTI antimicrobial. Sulopenem is active against both Gram-negative and Gram-positive microorganisms. Sulopenem's ß-lactam ring alkylates the serine residues of penicillin-binding protein (PBP), which inhibits peptidoglycan cross-linking. Due to its ionization and low molecular weight, sulopenem passes through outer membrane proteins to reach PBPs of Gram-negative bacteria. While sulopenem activity is unaffected by many ß-lactamases, resistance arises from alterations in PBPs (e.g., methicillin-resistant Staphylococcus aureus [MRSA]), expression of carbapenemases (e.g., carbapenemase-producing Enterobacterales and in Stenotrophomonas maltophilia), reduction in the expression of outer membrane proteins (e.g., some Klebsiella spp.), and the presence of efflux pumps (e.g., MexAB-OprM in Pseudomonas aeruginosa), or a combination of these mechanisms. In vitro studies have reported that sulopenem demonstrates greater activity than meropenem and ertapenem against Enterococcus faecalis, Listeria monocytogenes, methicillin-susceptible S. aureus (MSSA), and Staphylococcus epidermidis, as well as similar activity to carbapenems against Streptococcus agalactiae, Streptococcus pneumoniae, and Streptococcus pyogenes. With some exceptions, sulopenem activity against Gram-negative aerobes was less than ertapenem and meropenem but greater than imipenem. Sulopenem activity against Escherichia coli carrying ESBL, CTX-M, or Amp-C enzymes, or demonstrating MDR phenotypes, as well as against ESBL-producing Klebsiella pneumoniae, was nearly identical to ertapenem and meropenem and greater than imipenem. Sulopenem exhibited identical or slightly greater activity than imipenem against many Gram-positive and Gram-negative anaerobes, including Bacteroides fragilis. The pharmacokinetics of intravenous sulopenem appear similar to carbapenems such as imipenem-cilastatin, meropenem, and doripenem. In healthy subjects, reported volumes of distribution (Vd) ranged from 15.8 to 27.6 L, total drug clearances (CLT) of 18.9-24.9 L/h, protein binding of approximately 10%, and elimination half-lives (t½) of 0.88-1.03 h. The estimated renal clearance (CLR) of sulopenem is 8.0-10.6 L/h, with 35.5% ± 6.7% of a 1000 mg dose recovered unchanged in the urine. An ester prodrug, sulopenem etzadroxil, has been developed for oral administration. Initial investigations reported a variable oral bioavailability of 20-34% under fasted conditions, however subsequent work showed that bioavailability is significantly improved by administering sulopenem with food to increase its oral absorption or with probenecid to reduce its renal tubular secretion. Food consumption increases the area under the curve (AUC) of oral sulopenem (500 mg twice daily) by 23.6% when administered alone and 62% when administered with 500 mg of probenecid. Like carbapenems, sulopenem demonstrates bactericidal activity that is associated with the percentage of time that free concentrations exceed the MIC (%f T > MIC). In animal models, bacteriostasis was associated with %f T > MICs ranging from 8.6 to 17%, whereas 2-log10 kill was seen at values ranging from 12 to 28%. No pharmacodynamic targets have been documented for suppression of resistance. Sulopenem concentrations in urine are variable, ranging from 21.8 to 420.0 mg/L (median 84.4 mg/L) in fasted subjects and 28.8 to 609.0 mg/L (median 87.3 mg/L) in those who were fed. Sulopenem has been compared with carbapenems and cephalosporins in guinea pig and murine systemic and lung infection animal models. Studied pathogens included Acinetobacter calcoaceticus, B. fragilis, Citrobacter freundii, Enterobacter cloacae, E. coli, K. pneumoniae, Proteus vulgaris, and Serratia marcescens. These studies reported that overall, sulopenem was non-inferior to carbapenems but appeared to be superior to cephalosporins. A phase III clinical trial (SURE-1) reported that sulopenem was not non-inferior to ciprofloxacin in women infected with fluoroquinolone-susceptible pathogens, due to a higher rate of asymptomatic bacteriuria in sulopenem-treated patients at the test-of-cure visit. However, the researchers reported superiority of sulopenem etzadroxil/probenecid over ciprofloxacin for the treatment of uncomplicated UTIs in women infected with fluoroquinolone/non-susceptible pathogens, and non-inferiority in all patients with a positive urine culture. A phase III clinical trial (SURE-2) compared intravenous sulopenem followed by oral sulopenem etzadroxil/probenecid with ertapenem in the treatment of complicated UTIs. No difference in overall success was noted at the end of therapy. However, intravenous sulopenem followed by oral sulopenem etzadroxil was not non-inferior to ertapenem followed by oral stepdown therapy in overall success at test-of-cure due to a higher rate of asymptomatic bacteriuria in the sulopenem arm. After a meeting with the US FDA, Iterum stated that they are currently evaluating the optimal design for an additional phase III uncomplicated UTI study to be conducted prior to the potential resubmission of the New Drug Application (NDA). It is unclear at this time whether Iterum intends to apply for EMA or Japanese regulatory approval. The safety and tolerability of sulopenem has been reported in various phase I pharmacokinetic studies and phase III clinical trials. Sulopenem (intravenous and oral) appears to be well tolerated in healthy subjects, with and without the coadministration of probenecid, with few serious drug-related treatment-emergent adverse events (TEAEs) reported to date. Reported TEAEs affecting ≥1% of patients were (from most to least common) diarrhea, nausea, headache, vomiting and dizziness. Discontinuation rates were low and were not different than comparator agents. Sulopenem administered orally and/or intravenously represents a potentially well tolerated and effective option for treating uncomplicated and complicated UTIs, especially in patients with documented or highly suspected antimicrobial pathogens to commonly used agents (e.g. fluoroquinolone-resistant E. coli), and in patients with documented microbiological or clinical failure or patients who demonstrate intolerance/adverse effects to first-line agents. This agent will likely be used orally in the outpatient setting, and intravenously followed by oral stepdown in the hospital setting. Sulopenem also allows for oral stepdown therapy in the hospital setting from intravenous non-sulopenem therapy. More clinical data are required to fully assess the clinical efficacy and safety of sulopenem, especially in patients with complicated UTIs caused by resistant pathogens such as ESBL-producing, Amp-C, MDR E. coli. Antimicrobial stewardship programs will need to create guidelines for when this oral and intravenous penem should be used.


Assuntos
Bacteriúria , Staphylococcus aureus Resistente à Meticilina , Pró-Fármacos , Infecções Urinárias , Monofosfato de Adenosina/farmacologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriúria/induzido quimicamente , Bacteriúria/tratamento farmacológico , Carbapenêmicos/farmacologia , Cefalosporinas/farmacologia , Ciprofloxacina/farmacologia , Ertapenem , Escherichia coli , Feminino , Fluoroquinolonas/farmacologia , Bactérias Gram-Negativas , Cobaias , Humanos , Imipenem/farmacologia , Lactamas , Masculino , Proteínas de Membrana/farmacologia , Meropeném/farmacologia , Camundongos , Probenecid/farmacologia , Pró-Fármacos/farmacologia , Staphylococcus aureus , Infecções Urinárias/tratamento farmacológico , beta-Lactamases/farmacologia
8.
Front Public Health ; 10: 765624, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35309213

RESUMO

The carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) poses a severe therapeutic challenge to global public health, and research on CR-hvKP in older patients remain limited. In this study, we aimed to investigate the clinical and molecular characteristics and risk factors of CR-hvKP infections in older patients. We retrospectively investigated older patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) infections in the intensive care unit (ICU) between January 2020 and December 2020. The clinical data, and microbiological data including antimicrobial susceptibility testing, phenotype experiment and detection of carbapenemases, string test, virulence genes, capsular serotype-specific (cps) genes, and multilocus sequence typing, of the CR-hvKP group defined by the presence of any one of the virulence genes, including rmpA, rmpA2, iucA, iroN, and peg-344 were compared with those of CR-non-hvKP strains. Of the 80 CRKP strains, 51 (63.8%) met the definition of CR-hvKP. The main mechanism of resistance to carbapenems was the presence of the bla KPC-2 gene. Sequence type (ST)11 (81.3%, 65/80) and ST15 (16.3%, 13/80) were the most common STs in CRKP strains. The minimum inhibitory concentration (MIC)50 values of the CR-hvKP group against the six tested antibiotics (ceftazidime, ceftazidime-avibactam, imipenem-avibactam, tigecycline, levofloxacin, and Cefoperazone-Sulbactam) exhibited elevated levels than the CR-non-hvKP group. Ceftazidime and imipenem by combining avibactam (4 µg/mL) significantly decreased the MIC90 values more than 16-fold than ceftazidime and imipenem alone against Klebsiella pneumoniae carbapenemase (KPC)-2-producing K. pneumoniae. Cardiovascular disease [odds ratio (OR) = 11.956] and ST11-K64 (OR = 8.385) appeared to be independent variables associated with CR-hvKP infection by multivariate analysis. In conclusion, higher MICs of the last line antibiotic agents (ceftazidime-avibactam, tigecycline) might be a critical consideration in the clinical management of older patients where the concentration of these toxic antibiotics matters because of underlying comorbidities. Caution regarding KPC-2-producing ST11-K64 CR-hvKP as being new significant "superbugs" is required as they are widespread, and infection control measures should be strengthened to curb further dissemination in nosocomial settings in China.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Idoso , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Carbapenêmicos/farmacologia , Ceftazidima , Humanos , Imipenem , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Estudos Retrospectivos , Tigeciclina
9.
Antimicrob Agents Chemother ; 66(4): e0217921, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35293781

RESUMO

We show that a previously described Klebsiella pneumoniae variant that is resistant to ceftazidime-avibactam plus meropenem-vaborbactam, has a ramR plus ompK36 mutation, and produces the V239G variant KPC-3 (V240G per the standard numbering system) exhibits resistance to ceftazidime-avibactam plus aztreonam and imipenem-relebactam but not cefepime-taniborbactam. The V239G variant does not generate collateral ß-lactam susceptibility like many KPC-3 variants associated with ceftazidime-avibactam resistance. Additional mutation of ompK35 and production of the OXA-48-like carbapenemase OXA-232 were required to confer cefepime-taniborbactam resistance.


Assuntos
Aztreonam , Klebsiella pneumoniae , Antibacterianos/farmacologia , Compostos Azabicíclicos/farmacologia , Aztreonam/farmacologia , Proteínas de Bactérias/genética , Ácidos Borínicos , Ácidos Borônicos , Ácidos Carboxílicos , Cefepima/farmacologia , Ceftazidima/farmacologia , Combinação de Medicamentos , Imipenem/farmacologia , Klebsiella pneumoniae/genética , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
10.
Antimicrob Agents Chemother ; 66(4): e0212421, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35311523

RESUMO

ß-Lactamase-mediated resistance to ceftazidime-avibactam (CZA) is a serious limitation in the treatment of Gram-negative bacteria harboring Klebsiella pneumoniae carbapenemase (KPC). Herein, the basis of susceptibility to carbapenems and resistance to ceftazidime (CAZ) and CZA of the D179Y variant of KPC-2 and -3 was explored. First, we determined that resistance to CZA in a laboratory strain of Escherichia coli DH10B was not due to increased expression levels of the variant enzymes, as demonstrated by reverse transcription PCR (RT-PCR). Using timed mass spectrometry, the D179Y variant formed prolonged acyl-enzyme complexes with imipenem (IMI) and meropenem (MEM) in KPC-2 and KPC-3, which could be detected up to 24 h, suggesting that IMI and MEM act as covalent ß-lactamase inhibitors more than as substrates for D179Y KPC-2 and -3. This prolonged acyl-enzyme complex of IMI and MEM by D179Y variants was not observed with wild-type (WT) KPCs. CAZ was studied and the D179Y variants also formed acyl-enzyme complexes (1 to 2 h). Thermal denaturation and differential scanning fluorimetry showed that the tyrosine substitution at position 179 destabilized the KPC ß-lactamases (KPC-2/3 melting temperature [Tm] of 54 to 55°C versus D179Y Tm of 47.5 to 51°C), and the D179Y protein was 3% disordered compared to KPC-2 at 318 K. Heteronuclear 1H/15N-heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy also revealed that the D179Y variant, compared to KPC-2, is partially disordered. Based upon these observations, we discuss the impact of disordering of the Ω loop as a consequence of the D179Y substitution. These conformational changes and disorder in the overall structure as a result of D179Y contribute to this unanticipated phenotype.


Assuntos
Ceftazidima , Infecções por Klebsiella , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Compostos Azabicíclicos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Ceftazidima/farmacologia , Combinação de Medicamentos , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Imipenem/farmacologia , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae , Espectroscopia de Ressonância Magnética , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , beta-Lactamases/genética , beta-Lactamases/metabolismo
11.
Microbiol Spectr ; 10(2): e0274021, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35315696

RESUMO

Extensively drug-resistant Pseudomonas aeruginosa (XDRPA) infection is a significant public health threat due to a lack of effective therapeutic options. New ß-lactam-ß-lactamase inhibitor combinations, including ceftazidime-avibactam (CZA), have shown a high resistance rate to XDRPA. This study was therefore conducted to describe the underlying genomic mechanism of resistance for CZA nonsusceptible XDRPA strains that are non-metallo-ß-lactamase (MBL) producers as well as to examine synergism of CZA and other antipseudomonal agents. Furthermore, the synergistic antibacterial activity of the most effective antimicrobial combination against non-MBL-producing XDRPA was evaluated through in vitro experiments. The resistance profiles of 15 CZA-resistant XDRPA strains isolated from clinical specimens in China-Japan Friendship Hospital between January 2017 to December 2020 were obtained by whole-genome sequencing (WGS) analysis. MBL genes blaIMP-1 and blaIMP-45 were found in 2 isolates (2/15, 13.3%); the other underlying CZA-resistance mechanisms involved the decreased OprD porin (13/13), blaAmpC overexpression (8/13) or mutation (13/13), and upregulated efflux pumps (13/13). CZA-imipenem (CZA-IPM) combination was identified to be the most effective against non-MBL-producing XDRPA according to the results of WGS analysis and combined antimicrobial susceptibility tests, with an approximately 16.62-fold reduction in MICs compared to CZA alone. Furthermore, the results of checkerboard analysis and growth curve displayed the synergistic antimicrobial activity of CZA and IPM against non-MBL-producing XDRPA. Electron microscopy also revealed that CZA-IPM combination might lead to more cellular structural alterations than CZA or IPM alone. This study suggested that the CZA-IPM combination has potential for non-MBL-producing XDRPA with blaAmpC overexpression or mutation, decreased OprD porin, and upregulated efflux pumps. IMPORTANCE Handling the infections by extensively drug-resistant Pseudomonas aeruginosa (XDRPA) strains is challenging due to their complicated antibiotic resistance mechanisms in immunosuppressed patients with pulmonary diseases (e.g., cystic fibrosis, chronic obstructive pulmonary disease, and lung transplant), ventilator-associated pneumonia, and bloodstream infections. The current study suggested the potentiality of the ceftazidime-avibactam-imipenem combination against XDRPA with blaAmpC overexpression or mutation, decreased OprD porin, and/or upregulated efflux pumps. Our findings indicate the necessity of combined drug sensitivity tests against XDRPA and also lay a foundation for the development of prevention, control, and treatment strategies in XDRPA infections.


Assuntos
Ceftazidima , Infecções por Pseudomonas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Compostos Azabicíclicos , Ceftazidima/farmacologia , Ceftazidima/uso terapêutico , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Imipenem/farmacologia , Imipenem/uso terapêutico , Inosina Monofosfato/farmacologia , Inosina Monofosfato/uso terapêutico , Testes de Sensibilidade Microbiana , Porinas/farmacologia , Porinas/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , beta-Lactamases/genética
12.
Appl Microbiol Biotechnol ; 106(7): 2471-2480, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35316383

RESUMO

The evolution of metallo-beta-lactamase CphA in discontinuous gradient concentration of imipenem was investigated in this work. The results suggested that single-base mutations K218R, K249T, K249M, Q253H, and a frameshift mutation M1 were observed. Compared with wild type, the minimum inhibitory concentration (MICs) of K249T, K249M, and M1 increased by at least 128 times and that of K218R increased by 64 times. And the catalytic efficiency increased by 312% and 653%, respectively. It is speculated from the details of the structural changes revealed by molecular dynamics simulations that the carbon skeleton migration caused by the outward motion of the loop 3 in the mutant may have significantly increased the cavity volume of the binding pocket, which is more conducive to the entry and expulsion of imipenem and its hydrolytic product. And the conformational change of the TDRAGGN (71-77) is located at the bottom of the binding pocket from order α-helix to disorder random coil enabled the binding pocket to be more conducive to accommodate and hold the imipenem respectively. All these indicated that during the repeated drug resistance, the wild-type achieved gene mutations and conformational change and evolved to the mutant enzymes with a more delicate structure and stronger hydrolysis ability. KEY POINTS: • The mutation and evolution of CphA under the selective pressure of imipenem. • The CphA evolved to the mutants with stronger hydrolysis capacity. • A novel pathway for the resistance of super bacteria.


Assuntos
Imipenem , beta-Lactamases , Bactérias/metabolismo , Imipenem/química , Imipenem/metabolismo , Imipenem/farmacologia , Testes de Sensibilidade Microbiana , Mutação , beta-Lactamases/metabolismo
13.
J Antimicrob Chemother ; 77(5): 1301-1305, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35165715

RESUMO

OBJECTIVES: To investigate the antibacterial activity of the novel ß-lactamase inhibitor BLI-489 combined with imipenem or meropenem against diverse carbapenemase-producing carbapenem-resistant Enterobacterales (CRE) in vivo and in vitro. METHODS: Twenty-five CRE strains, including Klebsiella pneumoniae (n = 10), Escherichia coli (n = 6) and Enterobacter cloacae (n = 9), were used in chequerboard assays to evaluate the synergistic effect of BLI-489 combined with imipenem or meropenem. A cytotoxicity test was used to detect the toxicity of BLI-489 monotherapy or combination therapy. Three isolates producing class A, B and D carbapenemases, respectively, were selected to further confirm the synergistic effect in vitro by time-kill assays and in vivo by the Galleria mellonella infection model. RESULTS: Chequerboard assays demonstrated that BLI-489 combined with imipenem had a synergistic effect on 7/10, 7/9 and 5/6 of carbapenem-resistant K. pneumoniae, E. cloacae and E. coli, respectively, while BLI-489 and meropenem had a synergistic effect on 8/10, 9/9 and 6/6 of the isolates, respectively. No cytotoxicity was observed when BLI-489 was used alone or in combination with imipenem or meropenem at the test concentrations. In the time-kill assays, combination therapy had a synergistic effect on DC5114 carrying blaKPC-2, FK8401 carrying blaNDM-5 and CG996 carrying blaOXA-23. The synergistic effect in vivo was confirmed by the G. mellonella infection model. CONCLUSIONS: The novel ß-lactamase inhibitor BLI-489 possesses a synergistic effect against diverse carbapenemase-producing CRE combined with imipenem or meropenem.


Assuntos
Imipenem , Inibidores de beta-Lactamases , Antibacterianos/farmacologia , Proteínas de Bactérias/farmacologia , Carbapenêmicos/farmacologia , Escherichia coli , Imipenem/farmacologia , Klebsiella pneumoniae , Lactamas , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Monobactamas/farmacologia , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/farmacologia
14.
Infect Genet Evol ; 98: 105234, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35121093

RESUMO

Empedobacter falsenii is an emerging opportunistic pathogen that has been occasionally implicated in various human infections. In this study, we described the genomic features of a multidrug resistant E. falsenii Q1655 obtained from a patient attending a public hospital in Sokoto, northwest Nigeria. The isolate, E. falsenii Q1655, was isolated from the stool sample of a patient in Sokoto, Nigeria. The identity of the isolate was confirmed by MALDITOF-MS. The disc diffusion test and modified Carba-NP test were used for phenotypic antibiotic susceptibility test and carbapenemase enzyme production test, respectively. The whole genome of the strain was sequenced using the Illumina MiSeq technique. Resistome analysis was done by annotation of the WGS against the ARG-ANNOT database. The isolate was resistant to all ß-lactam antibiotics with the exception of cefepime. The MICs of imipenem and ertapenem as determined by E-test were 12 µg/ml and 2 µg/ml, respectively. Modified Carba NP test showed that the strain was carbapenemase producing. Resistome analysis revealed the presence of a novel metallo-ß-lactamase, a chromosomal blaEBR-4, which exhibited 94.92% and 97.02% nucleotide and protein sequence identities respectively with blaEBR-3 gene of E. falsenii 174,820. Seven and eight amino-acid substitutions were observed with the blaEBR-1 and blaEBR-2, respectively. We reported the first isolation and genomic description of an extensively drug resistant isolate of Empedobacter falsenii in Nigeria. This report broadens our knowledge of carbapenem resistance in E. falsenii and it will serve as a useful guide in the development of antibiotic use policy.


Assuntos
Antibacterianos/farmacologia , Ertapenem/farmacologia , Flavobacteriaceae/genética , Genoma Bacteriano , Imipenem/farmacologia , beta-Lactamases/genética , Flavobacteriaceae/enzimologia , Testes de Sensibilidade Microbiana , beta-Lactamases/metabolismo
15.
FEMS Microbiol Lett ; 369(1)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35147175

RESUMO

The carbapenem-resistant Escherichia coli has aroused increasing attention worldwide, especially in terms of imipenem (IMP) resistance. The molecular mechanism of IMP resistance remains unclear. This study aimed to explore the resistance mechanisms of IMP in E. coli. Susceptible Sx181-0-1 strain was induced into resistance strains by adaptive laboratory evolution. The drug resistance spectrum was measured using the disk diffusion and microbroth dilution methods. Whole-genome sequencing and resequencing were used to analyze the nonsynonymous single-nucleotide polymorphisms (nsSNPs) between the primary susceptible strain and resistant strains. The expression levels of these genes with nsSNPs were identified by real-time quantitative PCR (RT-qPCR). Resistance phenotype appeared in the induced 15th generation (induction time = 183 h). Sx181-32 and Sx181-256, which had the minimum inhibitory concentrations of IMP of 8 and 64 µg ml-1, were isolated during continuous subculture exposed to increasing concentrations of IMP, respectively. A total of 19 nsSNPs were observed both in Sx181-32 and Sx181-256, distributed in rpsU, sdaC, zwf, ttuC, araJ, dacC, mrdA, secF, dacD, lpxD, mrcB, ftsI, envZ, and two unknown function genes (orf01892 and orf01933). Among these 15 genes, five genes (dacC, mrdA, lpxD, mrcB, and ftsI) were mainly involved in cell wall synthesis. The mrdA (V338A, L378P, and M574I) and mrcB (P784L, A736V, and T708A) had three amino acid substitutions, respectively. The expression levels of rpsU, ttuC, and orf01933 were elevated in both Sx181-32 and Sx181-256 compared to Sx181-0-1. The expression levels of these genes were elevated in Sx181-256, except for araJ. Bacteria developed resistance to antimicrobials by regulating various biological processes, among which the most involved is the cell wall synthesis (dacC, mrdA, lpxD, mrcB, and ftsI). The combination mutations of mrdA, envZ, and ftsI genes may increase the resistance to IMP. Our study could improve the understanding of the molecular mechanism of IMP resistance in E. coli.


Assuntos
Proteínas de Escherichia coli , Imipenem , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Genômica , Imipenem/farmacologia , Testes de Sensibilidade Microbiana , Proteínas de Ligação às Penicilinas/genética , beta-Lactamases/genética
17.
J Med Chem ; 65(5): 3913-3922, 2022 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-35188771

RESUMO

Drug-resistant pathogens pose a global challenge to public health as they cause diseases that are extremely difficult to cure. Metallo-ß-lactamases (MBLs) are a diverse set of zinc-containing enzymes that catalyze the hydrolysis of ß-lactam drugs, including carbapenems, which are considered as the last resort to fight severe infections. To restore the activity of current ß-lactam antibiotics and to offer an orthogonal strategy to the discovery of new antibiotics, we have identified a series of polar N-aryl mercaptopropionamide derivatives as potent inhibitors of several class B1 MBLs. We have identified a hit structure with high selectivity restoring the effect of imipenem and reducing minimum inhibitory concentration (MIC) values up to 256-fold in resistant isolates from Escherichia coli. Furthermore, the combination of imipenem with our inhibitor showed in vivo efficacy in a Galleria mellonella model, increasing the survival rate of infected larvae by up to 31%.


Assuntos
Inibidores de beta-Lactamases , beta-Lactamases , Antibacterianos/química , Antibacterianos/farmacologia , Escherichia coli , Imipenem/química , Imipenem/farmacologia , Testes de Sensibilidade Microbiana , Inibidores de beta-Lactamases/química , Inibidores de beta-Lactamases/farmacologia , beta-Lactamases/química , beta-Lactamas/farmacologia
18.
J Clin Microbiol ; 60(3): e0224521, 2022 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-35107303

RESUMO

The emergence of Klebsiella pneumoniae isolates carrying novel blaKPC variants conferring ceftazidime-avibactam (CAZ/AVI) resistance is being increasingly reported. We evaluated the accuracy of phenotypic methods commonly used in routine clinical laboratories in the detection of novel K. pneumoniae carbapenemase (KPC) enzymes. Additionally, we characterized by whole-genome sequencing (WGS) the KPC-ST307-K. pneumoniae isolates recovered in our hospital before and after CAZ/AVI therapy. Rectal colonization or infection by carbapenem-resistant KPC-3 K. pneumoniae isolates (imipenem MIC, 16 mg/L; meropenem MIC, 8 to >16 mg/L) and CAZ/AVI-susceptible isolates (CAZ/AVI MIC, 1 to 2 mg/L) were first detected in three intensive care unit (ICU) patients admitted between March 2020 and July 2020. KPC K. pneumoniae isolates with increased CAZ/AVI MICs (8 to 32 mg/L) and carbapenem susceptibility (imipenem and meropenem MIC, <1 mg/L) were recovered within 6 to 24 days after CAZ/AVI treatment. WGS confirmed that all KPC K. pneumoniae isolates belonged to the sequence type 307 (ST307) high-risk clone and carried identical antimicrobial resistance genes and virulence factors. The presence of the novel blaKPC-46, blaKPC-66, and blaKPC-92 genes was confirmed in the K. pneumoniae isolates with increased CAZ/AVI MICs and restored carbapenem activity. KPC production was confirmed by immunochromatography, the eazyplex Superbug CRE system, and the Xpert Carba-R assay in all KPC K. pneumoniae isolates, but not in any isolate using chromogenic agar plates for carbapenemase producers (ChromID-CARBA), the KPC/MBL/OXA-48 Confirm kit, and the ß-CARBA test. Nevertheless, all grew in chromogenic agar plates for extended-spectrum ß-lactamase (ESBL) producers (ChromID-ESBL). We report the failure of the most common phenotypic methods used for the detection of novel KPC carbapenemases but not of rapid molecular or immunochromatography assays, thus highlighting their relevance in microbiology laboratories.


Assuntos
Infecções por Klebsiella , Klebsiella pneumoniae , Ágar , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Compostos Azabicíclicos , Proteínas de Bactérias/genética , Carbapenêmicos/uso terapêutico , Ceftazidima/farmacologia , Células Clonais , Combinação de Medicamentos , Humanos , Imipenem/uso terapêutico , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Meropeném , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
19.
J Bacteriol ; 204(3): e0059321, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35156836

RESUMO

With the increasing morbidity and mortality rates associated with multidrug-resistant bacteria, interest in bacteriophage therapy has been revived. However, bacterial resistance to phage infection threatens the usefulness of phage therapy, especially its inclusion in modern medicine. Multidrug-resistant Acinetobacter baumannii is a top-priority pathogen requiring urgent intervention and new therapeutic approaches, such as phage therapy. Here, we experimentally adapted A. baumannii WHG40004 to its lytic phage P21 and thereafter isolated a phage-resistant bacterial mutant, named Ev5-WHG. We then aimed to identify potential agents to aid phage killing of Ev5-WHG by analyzing its genome and that of the wild-type strain. The enriched Gene Ontology (GO) analysis based on genetic alterations in minor alleles and mutations showed that pathways such as zinc ion transport and cell membrane synthesis could play certain roles in phage resistance. Remarkably, the combination of zinc acetate and P21 showed increased bactericidal effect on Ev5-WHG. Significantly also, we showed that P21 completely prevented the growth of wild-type WHG40004 in the presence of antibiotics (meropenem and imipenem). The results from this study indicate that the analysis of phage resistance signatures during adaptation of bacteria to a lytic phage can inform the choice of agents to work cooperatively with phage to limit and/or reverse resistance. This approach could be important for guiding future successful phage therapy. IMPORTANCE Bacteriophages have proven very useful as alternative therapeutic agents in combating multidrug-resistant bacterial infections; however, bacterial resistance to phages threatens their use. In this study, we showed a new strategy of leveraging genetic signatures that accompany phage resistance in bacteria to predict agents that can be used with lytic phages to combat multidrug-resistant Acinetobacter baumannii. Significantly, this approach was helpful in suggesting the use of zinc acetate to reduce resistance in phage-resistant bacteria, as well as the use of phage with antibiotics meropenem and imipenem to prevent resistance in a wild-type strain of multidrug-resistant A. baumannii. The approach of this study will be helpful for improving the outcome of phage therapy and in overcoming antimicrobial resistance.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Bacteriófagos , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriófagos/genética , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Imipenem/farmacologia , Imipenem/uso terapêutico , Meropeném/farmacologia , Meropeném/uso terapêutico , Acetato de Zinco/farmacologia , Acetato de Zinco/uso terapêutico
20.
Trop Biomed ; 39(1): 11-16, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35225295

RESUMO

Trimethoprim-sulfamethoxazole is an active agent against Burkholderia pseudomallei and is being used in intensive and maintenance phases of melioidosis therapy. In this study, we evaluated the bactericidal activities of ß-lactams (imipenem, ceftazidime and amoxicillin- clavulanate) alone and in combinations with trimethoprim-sulfamethoxazole against B. pseudomallei . Four clinical strains of B. pseudomallei were selected based on different genotypes that are frequently found in Malaysia. The minimum inhibitory concentrations of trimethoprim-sulfamethoxazole, ceftazidime, imipenem and amoxicillin-clavulanate were determined using microdilution broth method. The bactericidal activities and synergy effects of ß-lactams and/or trimethoprim-sulfamethoxazole were evaluated by checkerboard and static time-kill analyses at 1×MIC concentration of each antibiotic. Using checkerboard method, the ß-lactam/trimethoprim-sulfamethoxazole combinations exhibited ΣFIC of 0.75-4.00. In time-kill analysis, ceftazidime/trimethoprim-sulfamethoxazole combination demonstrated synergy against three strains (less 2.25-2.41 log 10 CFU/mL compared to the most active antibiotic monotherapy) whereas imipenem/trimethoprim-sulfamethoxazole combination regimen showed synergy against one strain (less 3.32 log 10 CFU/mL). No antagonist effect or major re-growth was observed in all combination regimens, whereas 11 out of 12 of ß-lactam monotherapy regimens were associated with re-growth of bacteria. However, all ß-lactam monotherapy regimens exhibited rapid and stronger killing activities against BUPS/07/14, in the initial 12 hours compared to ß-lactam/ trimethoprim- sulfamethoxazole combination regimens. The combination of ß-lactams with trimethoprim- sulfamethoxazole demonstrated better killing effect at 24 hours compared to monotherapy and no major bacterial regrowth was observed. Nevertheless, delay in killing activities of ß-lactam/trimethoprim-sulfamethoxazole combination regimens against BUPS/07/14 need further examination because this phenomenon can lead to treatment failure in some patients.


Assuntos
Antibacterianos , Burkholderia pseudomallei , Combinação Trimetoprima e Sulfametoxazol , Amoxicilina/farmacologia , Antibacterianos/farmacologia , Burkholderia pseudomallei/efeitos dos fármacos , Ceftazidima/farmacologia , Ácido Clavulânico/farmacologia , Imipenem/farmacologia , Malásia , Testes de Sensibilidade Microbiana , Combinação Trimetoprima e Sulfametoxazol/farmacologia
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