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1.
PLoS One ; 15(8): e0237474, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857767

RESUMO

The effective treatment of carbapenemase-producing Klebsiella pneumoniae infection has been limited and required novel potential agents. Due to the novel drug development crisis, using old antimicrobial agents and combination therapy have been highlighted. This study focused on fosfomycin which inhibits cell wall synthesis and has potential activity on Enterobacteriaceae. We evaluated fosfomycin activity against carbapenemase-producing K. pneumoniae and characterized fosfomycin resistance mechanisms. Fosfomycin revealed effective activity against only 31.8% of carbapenemase-producing K. pneumoniae isolates. The major resistance mechanism was FosA3 production. The co-occurrence of FosA3 overexpression with the mutation of glpT (or loss of glpT) and/or uhpT was mediated high-level resistance (MIC>256 mg/L) to fosfomycin. Moreover, fosA3 silenced in sixteen fosfomycin-susceptible isolates and the plasmid carrying fosA3 of these isolates increased 32- to 64-fold of fosfomycin MICs in Escherichia coli DH5α transformants. The in vitro activity of fosfomycin combination with amikacin by checkerboard assay showed synergism and no interaction in six (16.2%) and sixteen isolates (43.3%), respectively. No antagonism of fosfomycin and amikacin was observed. Notably, the silence of aac (6)'-Ib and aphA6 was observed in amikacin-susceptible isolates. Our study suggests that the combination of fosfomycin and amikacin may be insufficient for the treatment of carbapenemase-producing K. pneumoniae isolates.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/genética , Fosfomicina/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/metabolismo , Amicacina/farmacologia , Substituição de Aminoácidos , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/genética , Escherichia coli/metabolismo , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/patologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/isolamento & purificação , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Plasmídeos/metabolismo , RNA Mensageiro/metabolismo , beta-Lactamases/genética
2.
Mikrobiyol Bul ; 54(3): 378-391, 2020 Jul.
Artigo em Turco | MEDLINE | ID: mdl-32755515

RESUMO

Klebsiella pneumoniae is the cause of complicated and difficult-to-treat nosocomial infections such as sepsis, urinary tract infection, catheter related infections, pneumonia and surgical site infections in intensive care units. The biggest problem in infections with K.pneumoniae is that treatment options are limited due to multiple antibiotic resistance and consequently the increased morbidity and mortality. The widespread and improper use of carbapenems can lead to epidemics that are difficult to control, especially in intensive care units because of the acquired resistance to this group of antibiotics. Outbreaks and sporadic cases caused by carbapenem resistant K.pneumoniae (CRKP) species have been reported all over the world in recent years with increased frequency. The aim of this study was to determine the risk factors related to carbepenem resistance and mortality caused by K.pneumoniae infections in a university hospital anesthesia intensive care unit. The study was conducted between January 1st, 2016, and December 31st, 2018. Retrospective data were obtained from the patient and laboratory-based surveillance records. Adult patients (≥ 18 years) with K.pneumoniae growth in the blood, urine, abscess and tracheal aspirate samples collected 48 hours after admission to the intensive care unit were considered as the relevant infection locus-related agent and treated with antibacterial therapy. Clinical samples collected from patients were inoculated onto 5% sheep blood and eosin-methylene-blue (EMB) agar except the blood samples. Blood samples were cultured in blood culture bottles and incubated in an automated system. Gram staining was performed for the samples showing growth signal within five days and then inoculated onto 5% sheep blood and EMB agar media and were incubated for 18-24 hours at 35.5-37°C. Identification of the isolates was performed using Bruker IVD MALDI Biotyper 2.3 (Bruker Daltonik GmbH, Bremen, Almanya) based on "matrix-assisted laser desorption/ionization time-of-mass spectrometry (MALDI-TOF MS)". K.pneumoniae isolates were identified by obtaining reliability scores of 2.0 and above in the study. Antibiotic susceptibility tests were performed with Phoenix 100 (BD, New Jersey, ABD) automated system. Interpretations were made according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Combination disk diffusion test and polymerase chain reaction based tests were used to show the presence of carbapenemase in CRKP isolates. A total of 88 patients with K.pneumoniae infection were included in the study. The mean age of the patients was 74 ± 15 (range= 21-93) years and 60.2% were female. CRKP was detected in 32 patients (36.4%) and carbapenem-sensitive K.pneumoniae (CSKP) was detected in 56 patients. The presence of OXA-48 was found to be 68.8% in the carbapenem screening test performed by combination disc method in patients with CRKP. Multivariate logistic regression analysis showed that previous use of colistin [Odds ratio (OR)= 19.108; 95% confidence interval (CI)= 2.027-180.133; p= 0.010] and aminoglycoside (OR= 12.189; 95% CI= 1.256-118.334; p= 0.031) was an independent risk factor in terms of CRCP among the patients with K.pneumoniae infection. The 28-day mortality rates were 71.9% in the CRKP group (23/32) and 37.5% in the CSKP group (21/56). Presence of CRKP in terms of 28-day mortality (OR= 5.146; 95% CI= 1.839-14.398; p= 0.002) was an independent risk factor. The data obtained in this study will guide for conducting effective and continuous surveillance studies and implementing rational antibiotic programs to prevent the increase in CRKP.


Assuntos
Carbapenêmicos , Farmacorresistência Bacteriana , Unidades de Terapia Intensiva , Infecções por Klebsiella , Klebsiella pneumoniae , Pneumonia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Feminino , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/mortalidade , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Fatores de Risco , Ovinos
3.
PLoS One ; 15(7): e0236505, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32701970

RESUMO

Multidrug resistance prompts the search for new sources of antibiotics with new targets at bacteria cell. To investigate the antibacterial activity of Cinnamomum cassia L. essential oil (CCeo) alone and in combination with antibiotics against carbapenemase-producing Klebsiella pneumoniae and Serratia marcescens. The antimicrobial susceptibility of the strains was determined by Vitek® 2 and confirmed by MALDI-TOF/TOF. The antibacterial activity of CCeo and its synergism with antibiotics was determined using agar disk diffusion, broth microdilution, time-kill, and checkboard methods. The integrity of the bacterial cell membrane in S. marcescens was monitored by protein leakage assay. CCeo exhibited inhibitory effects with MIC = 281.25 µg.mL-1. The association between CCeo and polymyxin B showed a decrease in terms of viable cell counts on survival curves over time after a 4 hour-treatment with a FIC index value of 0.006. Protein leakage was observed with increasing concentrations for CCeo and CCeo + polymyxin B treatments. CCeo showed antibacterial activity against the studied strains. When associated with polymyxin B, a synergistic effect was able to inhibit bacterial growth rapidly and consistently, making it a potential candidate for the development of an alternative treatment and drug delivery system for carbapenemase-producing strains.


Assuntos
Infecções por Klebsiella/tratamento farmacológico , Óleos Voláteis/farmacologia , Polimixina B/farmacologia , Infecções por Serratia/tratamento farmacológico , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/genética , Cinnamomum aromaticum/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Sinergismo Farmacológico , Humanos , Infecções por Klebsiella/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/patogenicidade , Infecções por Serratia/genética , Infecções por Serratia/microbiologia , Serratia marcescens/efeitos dos fármacos , Serratia marcescens/patogenicidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , beta-Lactamases/genética
4.
Proc Natl Acad Sci U S A ; 117(29): 17249-17259, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32641516

RESUMO

Control of infections caused by carbapenem-resistant Klebsiella pneumoniae continues to be challenging. The success of this pathogen is favored by its ability to acquire antimicrobial resistance and to spread and persist in both the environment and in humans. The emergence of clinically important clones, such as sequence types 11, 15, 101, and 258, has been reported worldwide. However, the mechanisms promoting the dissemination of such high-risk clones are unknown. Unraveling the factors that play a role in the pathobiology and epidemicity of K. pneumoniae is therefore important for managing infections. To address this issue, we studied a carbapenem-resistant ST-15 K. pneumoniae isolate (Kp3380) that displayed a remarkable adherent phenotype with abundant pilus-like structures. Genome sequencing enabled us to identify a chaperone-usher pili system (Kpi) in Kp3380. Analysis of a large K. pneumoniae population from 32 European countries showed that the Kpi system is associated with the ST-15 clone. Phylogenetic analysis of the operon revealed that Kpi belongs to the little-characterized γ2-fimbrial clade. We demonstrate that Kpi contributes positively to the ability of K. pneumoniae to form biofilms and adhere to different host tissues. Moreover, the in vivo intestinal colonizing capacity of the Kpi-defective mutant was significantly reduced, as was its ability to infect Galleria mellonella The findings provide information about the pathobiology and epidemicity of Kpi+ K. pneumoniae and indicate that the presence of Kpi may explain the success of the ST-15 clone. Disrupting bacterial adherence to the intestinal surface could potentially target gastrointestinal colonization.


Assuntos
Fímbrias Bacterianas/genética , Klebsiella pneumoniae/genética , Chaperonas Moleculares/genética , Células A549 , Animais , Antibacterianos , Aderência Bacteriana/efeitos dos fármacos , Aderência Bacteriana/genética , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Carbapenêmicos/farmacologia , Linhagem Celular , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/genética , Células Epiteliais/microbiologia , Europa (Continente) , Feminino , Deleção de Genes , Genes Bacterianos/genética , Humanos , Infecções por Klebsiella , Klebsiella pneumoniae/citologia , Klebsiella pneumoniae/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Tipagem de Sequências Multilocus , Óperon , Filogenia
5.
Int J Food Microbiol ; 331: 108750, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-32559710

RESUMO

For the first time, this study evaluates consumer exposure via poultry meat to Enterobacteriaceae with capacity to develop severe extraintestinal infections by either bacterial virulence and/or antibiotic resistance traits. The characterization of 256 isolates and the assessment of five parameters, showed that 96 of 100 poultry meat samples from supermarkets of northwest Spain posed ≥ one potential risk: i) 96% carried Enterobacteriaceae resistant to antimicrobials of categories A (64% to monobactams) or B (95% to cephalosporins 3rd and 4rd- generation, quinolones and/or polymixins) of the new categorization of EMA. ii) More than one extended-spectrum-ß-lactamase (ESBL)-producing Enterobacteriaceae species were recovered from 28% of poultry meat. iii) High-risk lineages of E. coli, including multidrug-resistant ST131-H22, were present in 62% of samples. iv) E. coli recovered from 25% of samples conformed the ExPEC status. v) E. coli from 17% of samples satisfied the UPEC status. Of note, the recovery from different samples of two E. coli CC10-A (CH11-54) carrying mcr-1.1-bearing IncX4 plasmids, and four E. coli CC10-A (eae-beta1) of the hybrid pathotype aEPEC/ExPEC. (ESBL)-producing K. pneumoniae were isolated from 27% of samples. In summary, poultry meat microbiota is a source of genetically diverse Enterobacteriaceae, resistant to relevant antimicrobials and potentially pathogenic for consumers.


Assuntos
Exposição Dietética/estatística & dados numéricos , Resistência a Múltiplos Medicamentos , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Microbiologia de Alimentos/estatística & dados numéricos , Carne/microbiologia , Animais , Antibacterianos/farmacologia , Galinhas/microbiologia , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli Extraintestinal Patogênica/genética , Escherichia coli Extraintestinal Patogênica/isolamento & purificação , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Plasmídeos/genética , Espanha/epidemiologia , Perus , Escherichia coli Uropatogênica/efeitos dos fármacos , Escherichia coli Uropatogênica/genética , Escherichia coli Uropatogênica/isolamento & purificação
6.
BMC Infect Dis ; 20(1): 416, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32539687

RESUMO

BACKGROUND: Klebsiella pneumoniae (KP) is the primary pathogen associated with pyogenic liver abscesses (PLAs). Moreover, there has been an increase in the proportion of extended-spectrum beta-lactamase (ESBL)-producing KP. However, the clinical and computed tomography (CT) features of liver abscesses caused by ESBL-producing KP have not been separately described. We aimed to compare the clinical and CT features present in patients with ESBL-producing and non-ESBL-producing KP as well as to determine the risk factors for ESBL-producing KP liver abscesses (KPLAs). METHODS: We performed a retrospective analysis of data obtained from the medical records of patients with a first episode of KPLA admitted to Shengjing Hospital of China Medical University between May 2015 and May 2019. We compared the clinical and CT features between patients with ESBL-producing and non-ESBL-producing KPLA. RESULTS: We enrolled 100 patients with KPLA (14 and 86 in the ESBL-producing and non-ESBL-producing groups, respectively). There was no significant between-group difference in the proportion of patients with comorbid diabetes (71.43% vs. 66.2%, p = 0.086). The ESBL-producing KPLA group had a greater proportion of patients with a history of biliary disease (78.57% vs. 26.74%, p < 0.001) and gastrointestinal malignancy (50% vs. 6.98%, p < 0.001). Multivariate regression analysis showed that a history of biliary disease was an independent risk factor for ESBL-producing KPLA. Compared with the non-ESBL-producing KPLA group, the ESBL-producing KPLA group had a significantly higher intensive care unit (ICU) admission rate (28.57% vs. 2.33%, p < 0.001). All ESBL-producing KP isolates were susceptible to carbapenems and amikacin. Only the presence of multiloculation on CT was found to be significantly different between the groups (50% vs. 82.56%, p = 0.012). CONCLUSIONS: The presence of biliary disease was an independent risk factor for ESBL-producing KPLA. Patients with ESBL-producing KPLA had a higher ICU admission rate, with only half of patients having evidence of multiloculation on CT.


Assuntos
Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/isolamento & purificação , Abscesso Hepático Piogênico/microbiologia , beta-Lactamases/biossíntese , Adulto , Antibacterianos/farmacologia , China/epidemiologia , Feminino , Humanos , Infecções por Klebsiella/diagnóstico por imagem , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/patologia , Klebsiella pneumoniae/efeitos dos fármacos , Abscesso Hepático Piogênico/diagnóstico por imagem , Abscesso Hepático Piogênico/epidemiologia , Abscesso Hepático Piogênico/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Tomografia Computadorizada por Raios X
7.
PLoS One ; 15(6): e0233704, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32516308

RESUMO

BACKGROUND: The pathogenic spectrum of bloodstream infections (BSIs) varies across regions. Monitoring the pathogenic profile and antimicrobial resistance is a prerequisite for effective therapy, infection control and for strategies aimed to counter antimicrobial resistance. The pathogenic spectrum of BSIs in blood cultures was analysed, focusing on the resistance patterns of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae, in Aljouf region. METHODS: This descriptive cross-sectional study analysed the culture reports of all non-duplicate blood samples collected from January 1 to December 31, 2019. Antibiograms of A. baumannii, E. coli, and K. pneumoniae were analysed for antibiotic resistance. The frequency and percentages of multi-drug, extensively-drug, pan-drug and carbapenem resistance were calculated. RESULTS: Of the 222 bloodstream infections, 62.2% and 36.4% were caused by gram-negative and gram-positive bacteria, respectively. Most BSIs occurred in patients aged ≥60 years (59.5%). Among the 103 isolates of the studied Gram-negative bacteria (GNB), 47.6%, 38.8%, and 2.9% were multi-drug, extensively drug and pan-drug resistant respectively. 46% of K. pneumoniae isolates were carbapenemase producers. Resistance to gentamycin, 1st-4th generation cephalosporins, and carbapenems was observed for A. baumannii. More than 70% of E. coli isolates were resistant to 3rd- and 4th-generation cephalosporins. Klebsiella pneumoniae presented a resistance rate of >60% to imipenems. CONCLUSIONS: Gram-negative bacteria dominate BSIs, with carbapenem-resistant K. pneumoniae most frequently detected in this region. Resistant GNB infections make it challenging to treat geriatric patients. Regional variations in antimicrobial resistance should be continually monitored.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/microbiologia , Carbapenêmicos/farmacologia , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/isolamento & purificação , Infecções por Acinetobacter/sangue , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Adulto , Antibacterianos/uso terapêutico , Bacteriemia/sangue , Bacteriemia/tratamento farmacológico , Bacteriemia/epidemiologia , Carbapenêmicos/uso terapêutico , Estudos Transversais , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Infecções por Klebsiella/sangue , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Arábia Saudita , Adulto Jovem
8.
Int J Biol Macromol ; 161: 936-938, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32534094

RESUMO

This short report is dedicated to the description of the wide antiviral and antibacterial activity of the immune-modulating agent Panavir®. Panavir® is a high-molecular-weight fraction of the polysaccharides extracted from the shoots of the Solanum tuberosum. It demonstrates activity against many types of viruses, including animal coronavirus and also against bacterial infections. These properties look very promising considering the COVID-19 epidemy and allow propose that Panavir® would be effective in the therapy of the SARS-CoV-2 infection.


Assuntos
Antivirais/farmacologia , Glicosídeos/farmacologia , Herpes Genital/tratamento farmacológico , Adulto , Animais , Antivirais/química , Antivirais/uso terapêutico , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Disenteria Bacilar/tratamento farmacológico , Feminino , Glicosídeos/química , Glicosídeos/uso terapêutico , Humanos , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Camundongos , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Shigella flexneri/efeitos dos fármacos , Adulto Jovem
9.
PLoS One ; 15(6): e0235059, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574199

RESUMO

BACKGROUND: To support effective antibiotic selection in empirical treatments, infection control interventions, and antimicrobial resistance containment strategies, many medical institutions collect antimicrobial susceptibility test data conducted at their facilities to prepare cumulative antibiograms. AIM: To evaluate how the setpoints of duplicate isolate removal period and data collection period affect the calculated susceptibility rates in antibiograms. METHODS: The Sakai City Medical Center is a regional core hospital for tertiary emergency medical care with 480 beds for general clinical care. In this study, all the Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae isolates collected at the Sakai City Medical Center Clinical Laboratory between July 2013 and December 2018 were subjected to antimicrobial susceptibility tests and the resulting data was analyzed. FINDINGS: The longer the duplicate isolate removal period, the fewer the isolates are available for every bacterial species. Differences in the length of the duplicate isolate removal period affected P. aeruginosa susceptibility rates to ß-lactam antibiotics by up to 10.8%. The setpoint of the data collection period affected the antimicrobial susceptibility rates by up to 7.3%. We found that a significant change in susceptibility could be missed depending on the setting of the data collection period, in preparing antibiogram of ß-lactam antibiotics for P. aeruginosa. CONCLUSIONS: When referring to antibiograms, medical professionals involved in infectious disease treatment should be aware that the parameter values, such as the duplicate isolate removal period and the data collection period, affect P. aeruginosa susceptibility rates especially to ß-lactam antibiotics. And antibiogram should be updated within the shortest time period that is practically possible, taking into account restrictions such as numbers of specimen.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Testes de Sensibilidade Microbiana/normas , Pseudomonas aeruginosa/efeitos dos fármacos , Algoritmos , Serviço Hospitalar de Emergência , Escherichia coli/isolamento & purificação , Escherichia coli/fisiologia , Hospitalização/estatística & dados numéricos , Humanos , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/fisiologia , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/fisiologia , Centros de Atenção Terciária , Fatores de Tempo
10.
Arch Microbiol ; 202(8): 2105-2115, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32500253

RESUMO

In this study, the antibacterial, anti-efflux, anti-biofilm, anti-slime (exopolysaccharide) production and urease inhibitory efficacies of green synthesized gold nanoparticles (AuNPs) coated Anthemis atropatana extract against multidrug- resistant (MDR) Klebsiella pneumoniae strains were evaluated. The green synthesized AuNPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffractometer (XRD), particle size distribution, zeta potential and Fourier-transform infrared spectroscopy (FTIR). Then, antibacterial, anti-slime (exopolysaccharide) production, anti-biofilm and anti-efflux activities of AuNPs were investigated using micro-dilation, Congored agar, microtiter plate and MIC of ethidium bromide methods, respectively. Subsequently, the expression of mrkA, wzm and acrB genes was evaluated using quantitative Real-Time PCR (qRT-PCR). The synthesized AuNPs exhibited antibacterial activity against MDR strains of K. pneumoniae (minimum inhibitory concentration (MIC) of 6.25-50 µg/ml), as well as showed significant anti-slime (exopolysaccharide) production, anti-biofilm and anti-efflux activities against MDR strains. AuNPs showed significant inhibition against jack-bean urease and down-regulated the expression of mrkA, wzm and acrB genes. Moreover, the in vitro cytotoxic activity confirmed by MTT assay on the HEK-293 normal cell line showed negligible cytotoxicity. Thus, the present study suggests the potential use of AuNPs in the development of novel therapeutics for the prevention of biofilm-associated K. pneumoniae infections.


Assuntos
Anthemis/química , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Ouro/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Nanopartículas Metálicas , Extratos Vegetais/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Ouro/química , Células HEK293 , Humanos , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Urease/metabolismo
11.
Medicine (Baltimore) ; 99(21): e20360, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32481328

RESUMO

RATIONALE: Invasive community-acquired infections, including pyogenic liver abscesses, caused by hypervirulent Klebsiella pneumoniae (hvKp) strains have been well recognized worldwide. Among these, sporadic hvKp-related community-acquired pneumonia (CAP) is an acute-onset, rapidly progressing disease that can likely turn fatal, if left untreated. However, the clinical diagnosis of hvKp infection remains challenging due to its non-specific symptoms, lack of awareness regarding this disease, and no consensus definition of hvKp. PATIENT CONCERNS: A 39-year-old man presented with high-grade fever and sudden-onset chest pain. Laboratory testing revealed an elevated white blood cell count of 11,600 cells/µl and C-reactive protein level (>32 mg/dl). A chest X-ray and computed tomography revealed a focal consolidation in the left lower lung field. DIAGNOSIS: Diagnosis of fulminant CAP caused by a hvKp K2-ST86 strain was made based upon multilocus sequencing typing (MLST). INTERVENTIONS: The patient was treated with ampicillin/sulbactam. OUTCOMES: The pneumonia became fulminant. Despite intensive care and treatment, he eventually died 15.5 hours after admission. LESSONS: This is the first case of fatal fulminant CAP caused by a hvKp K2-ST86 strain reported in Japan. MLST was extremely useful for providing a definitive diagnosis for this infection. Thus, we propose that a biomarker-based approach should be considered even for an exploratory diagnosis of CAP related to hvKp infection.


Assuntos
Pneumonia Associada a Assistência à Saúde/diagnóstico , Klebsiella pneumoniae/efeitos dos fármacos , Virulência/imunologia , Adulto , Dor no Peito/etiologia , Infecções Comunitárias Adquiridas/complicações , Infecções Comunitárias Adquiridas/fisiopatologia , Febre/etiologia , Pneumonia Associada a Assistência à Saúde/complicações , Pneumonia Associada a Assistência à Saúde/fisiopatologia , Humanos , Japão , Infecções por Klebsiella/complicações , Infecções por Klebsiella/etiologia , Infecções por Klebsiella/terapia , Klebsiella pneumoniae/patogenicidade , Masculino , Tipagem de Sequências Multilocus/métodos , Virulência/efeitos dos fármacos
12.
Emerg Top Life Sci ; 4(2): 129-136, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32463087

RESUMO

As the Royal Society for Biology (RSB) was forming 10 years ago, antimicrobial resistance (AMR) was being heralded as the next threat with a magnitude on a par with global warming. Just a few years later, in 2016, Jim O'Neill's report was published laying out recommendations for tackling drug-resistant infections globally. Where are we now, and what are the challenges ahead? As a slow burner, how will the impact of AMR compare against the recent rapid devastation of the COVID-19 pandemic, and how can we channel some of the good things that come from it (like the awareness and technique of effective hand hygiene) to help us combat AMR speedily and definitively?


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Farmacorresistência Bacteriana/efeitos dos fármacos , Betacoronavirus/efeitos dos fármacos , Biofilmes , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/prevenção & controle , Humanos , Controle de Infecções , Klebsiella pneumoniae/efeitos dos fármacos , Pandemias/prevenção & controle , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/prevenção & controle , Saúde Pública
13.
Rev Soc Bras Med Trop ; 53: e20200064, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32401864

RESUMO

INTRODUCTION: Carbapenem-resistant Klebsiella pneumoniae infection lacks treatment options and is associated with prolonged hospital stays and high mortality rates. The production of carbapenemases is one of the most important factors responsible for this multi-resistance phenomenon. METHODS: In the present study, we analyzed the presence of genes encoding carbapenemases in K. pneumoniae isolates circulating in one of the public hospitals in the city of Aracaju, Sergipe, Brazil. We also determined the best combination of drugs that display in vitro antimicrobial synergy. First, 147 carbapenem-resistant K. pneumoniae isolates were validated for the presence of blaKPC, bla GES, bla NDM, bla SPM, bla IMP, bla VIM, and bla OXA-48 genes using multiplex polymerase chain reaction. Thereafter, using two isolates (97 and 102), the role of double and triple combinational drug therapy as a treatment option was analyzed. RESULTS: Seventy-four (50.3%) isolates were positive for bla NDM, eight (5.4%) for bla KPC, and one (1.2%) for both bla NDM and bla KPC. In the synergy tests, double combinations were better than triple combinations. Polymyxin B and amikacin for isolate 97 and polymyxin B coupled with meropenem for isolate 102 showed the best response. CONCLUSIONS: Clinicians in normal practice use multiple drugs to treat infections caused by multi-resistant microorganism; however, in most cases, the benefit of the combinations is unknown. In vitro synergistic tests, such as those described herein, are important as they might help select an appropriate multi-drug antibiotic therapy and a correct dosage, ultimately reducing toxicities and the development of antibiotic resistance.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/genética , Brasil , DNA Bacteriano , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Prevalência
14.
Proc Natl Acad Sci U S A ; 117(20): 10639-10644, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32350139

RESUMO

The lack of rapid antibiotic susceptibility tests adversely affects the treatment of bacterial infections and contributes to increased prevalence of multidrug-resistant bacteria. Here, we describe an all-electrical approach that allows for ultrasensitive measurement of growth signals from only tens of bacteria in a microfluidic device. Our device is essentially a set of microfluidic channels, each with a nanoconstriction at one end and cross-sectional dimensions close to that of a single bacterium. Flowing a liquid bacteria sample (e.g., urine) through the microchannels rapidly traps the bacteria in the device, allowing for subsequent incubation in drugs. We measure the electrical resistance of the microchannels, which increases (or decreases) in proportion to the number of bacteria in the microchannels. The method and device allow for rapid antibiotic susceptibility tests in about 2 h. Further, the short-time fluctuations in the electrical resistance during an antibiotic susceptibility test are correlated with the morphological changes of bacteria caused by the antibiotic. In contrast to other electrical approaches, the underlying geometric blockage effect provides a robust and sensitive signal, which is straightforward to interpret without electrical models. The approach also obviates the need for a high-resolution microscope and other complex equipment, making it potentially usable in resource-limited settings.


Assuntos
Antibacterianos/toxicidade , Microfluídica/métodos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Impedância Elétrica , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/fisiologia , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/métodos , Microfluídica/instrumentação
15.
J Infect Public Health ; 13(9): 1330-1335, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32439355

RESUMO

BACKGROUND: Extended-spectrum ß-lactamase producing Enterobacteriaceae (ESBL-PE) and carbapenem-resistant Enterobacteriaceae (CRE) are disseminated worldwide posing a serious public health concern. Although, the presence of ESBL-PE and CRE in Sri Lanka has been reported, the prevalence is unknown. This study aimed to provide up-to-date epidemiological data on multidrug-resistant Enterobacteriaceae and to characterize the molecular determinants of carbapenemase-producing Enterobacteriaceae (CPE) in Sri Lanka. METHODS: A prospective cross-sectional study was conducted at a tertiary care hospital in Sri Lanka between December 2017 and February 2018. ESBL-PE and CRE were identified by disc diffusion method. Carbapenemase production was determined by carbapenem inactivation method and the presence of selected carbapenemase genes were detected by PCR. RESULTS: Five hundred and ninety three Enterobacteriaceae were isolated from variety of clinical samples. Overall prevalence of ESBL-PE and CRE were 26.0% (n = 154) and 9.6% (n = 57), respectively. The highest rate of ESBL-PE (30.8%) was found in urine samples, while the highest occurrence of CRE (20.8%) was seen in respiratory specimens. The most common CRE species identified was K. pneumoniae (n = 46, 80.7%), followed by C. freundii (n = 4, 7.0%), E. coli (n = 3, 5.3%), P. rettgeri (n = 2, 3.5%), E. cloacae (n = 1, 1.7%), and K. aerogenes (n = 1, 1.7%). Carbapenemase production was observed in 54 (94.7%) of CRE isolates. Fifty eight carbapenemase encoding genes were identified in 54 CPE. The most prevalent carbapenemase gene was blaOXA-48-like (n = 48, 88.9%), followed by blaNDM (n = 8, 14.8%), and blaKPC (n = 2, 3.7%). CONCLUSION: This study reports an alarming rate of CRE and the emergence of blaKPC harboring K. pneumoniae in Sri Lanka. The need for preventive measures is highlighted to limit the spread of these difficult-to-treat bacteria in the country.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Klebsiella pneumoniae/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Carbapenêmicos/farmacologia , Criança , Pré-Escolar , Estudos Transversais , Enterobacteriaceae/efeitos dos fármacos , Feminino , Humanos , Lactente , Recém-Nascido , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Prospectivos , Sri Lanka/epidemiologia , Adulto Jovem , Resistência beta-Lactâmica/genética , beta-Lactamases/genética
16.
PLoS One ; 15(5): e0232710, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32384111

RESUMO

With the growing threat of antimicrobial resistance worldwide, uncovering the molecular epidemiology is critical for understanding what is driving this crisis. We aimed to evaluate the prevalence of plasmid-mediated-quinolone-resistance (PMQR) and extended-spectrum beta-lactamase- (ESBL) producing gram-negative organisms among primigravid women with bacteriuria. We collected urine specimens from primigravid women attending their first antenatal visit at Gandhi Hospital during October 1, 2015 to September 30, 2016. We determined antimicrobial susceptibility and ESBL and quinolone resistance using VITEK-2. We performed polymerase chain reaction amplification on resistant isolates for detection of ESBL-encoding genes (TEM, SHV, CTX-M) and PMQR genes (qnrA, qnrB, qnrD, qnrS, aac (6')-Ib-cr). Of 1,841 urine samples, 133 demonstrated significant bacterial growth with gram-negative bacilli accounting for 85% of isolates, including Escherichia coli (n = 79), Klebsiella pneumoniae (n = 29), Sphingomonas (n = 3), Enterobacter (n = 1), and Citrobacter (n = 1). We found 65% of E. coli isolates and 41% of K. pneumoniae isolates were ESBL positive. Of ESBL-positive isolates, the most common genes conferring resistance were TEM-1 (66.7%) followed by CTX-M-15 (33.3%). Fifty-seven percent of ESBL-positive E. coli also demonstrated resistance to quinolones with the most common PMQR genes being qnr-S (62.5%) and aac (6')-Ib-cr (37.5%). We did not find any resistance to quinolones among ESBL-positive K. pneumoniae isolates. Across different classes of antibiotics we found a strong clustering of multi-drug resistance in E. coli with over 45% of ESBL-positive isolates demonstrating resistance to at least three classes of antibiotics. This study emphasizes the high prevalence of plasmid-mediated ESBL and quinolone resistance in community-acquired urinary tract infections of primigravid women. The overall abundance of multi-drug-resistant isolates in this population is alarming and may present therapeutic challenges.


Assuntos
Resistência Microbiana a Medicamentos/genética , Plasmídeos/genética , Infecções Urinárias/microbiologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Feminino , Genes Bacterianos , Humanos , Índia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Fenótipo , Gravidez , Quinolonas/farmacologia , beta-Lactamases/genética
17.
PLoS One ; 15(4): e0231503, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32282829

RESUMO

OBJECTIVES: The first hospital outbreak of carbapenemase-producing Enterobacteriaceae in Slovenia occurred in 2014-2016. Whole genome sequencing was used to analyse the population of carbapenem-resistant Klebsiella pneumoniae collected in Slovenia in 2014-2017, including OXA-48 and/or NDM-1 producing strains from the outbreak. METHODS: A total of 32 K. pneumoniae isolates were analysed using short-read sequencing. Multi-locus sequence typing and core genome multi-locus sequence typing were used to infer genetic relatedness. Antimicrobial resistance markers, virulence factors, plasmid content and wzi types were determined. Long-read sequencing was used for six isolates for detailed analysis of plasmids and their possible transmission. RESULTS: Overall, we detected 10 different sequence types (STs), the most common being ST437 (40.6%). Isolates from the initial outbreak belonged to ST437 (12/16) and ST147 (4/16). A second outbreak of four ST15 isolates was discovered. A new ST (ST3390) and two new wzi types (wzi-556, wzi-559) were identified. blaOXA-48 was found in 17 (53.1%) isolates, blaNDM-1 in five (15.6%), and a combination of blaOXA-48/NDM-1 in seven (21.9%) isolates. Identical plasmids carrying blaOXA-48 were found in outbreak isolates sequenced with long-read sequencing technology. CONCLUSIONS: Whole genome sequencing of Slovenian carbapenem-resistant K. pneumoniae isolates revealed multiple clusters of STs, two of which were involved in the first hospital outbreak of carbapenem producing K. pneumoniae in Slovenia. Transmission of the plasmid carrying blaOXA-48 between two STs was likely to have occurred. A previously unidentified second outbreak was also discovered, highlighting the importance of whole genome sequencing in detection and/or characterization of hospital outbreaks and surveillance of drug-resistant bacterial clones.


Assuntos
Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , beta-Lactamases/genética , Antibacterianos/uso terapêutico , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Carbapenêmicos/uso terapêutico , Surtos de Doenças , Humanos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Tipagem de Sequências Multilocus/métodos , Plasmídeos/genética , Eslovênia , Sequenciamento Completo do Genoma/métodos
18.
BMC Infect Dis ; 20(1): 312, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32345218

RESUMO

BACKGROUND: While there is increasing knowledge about the gut microbiome, the factors influencing and the significance of the gut resistome are still not well understood. Infant gut commensals risk transferring multidrug-resistant antibiotic resistance genes (ARGs) to pathogenic bacteria. The rapid spread of multidrug-resistant pathogenic bacteria is a worldwide public health concern. Better understanding of the naïve infant gut resistome may build the evidence base for antimicrobial stewardship in both humans and in the food industry. Given the high carriage rate of extended spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in Asia, we aimed to evaluate community prevalence, dynamics, and longitudinal changes in antibiotic resistance gene (ARG) profiles and prevalence of ESBL-producing E. coli and K. pneumoniae in the intestinal microbiome of infants participating in the Growing Up in Singapore Towards Healthy Outcomes (GUSTO) study, a longitudinal cohort study of pregnant women and their infants. METHODS: We analysed ARGs in the first year of life among 75 infants at risk of eczema who had stool samples collected at multiple timepoints using metagenomics. RESULTS: The mean number of ARGs per infant increased with age. The most common ARGs identified confer resistance to aminoglycoside, beta-lactam, macrolide and tetracycline antibiotics; all infants harboured these antibiotic resistance genes at some point in the first year of life. Few ARGs persisted throughout the first year of life. Beta-lactam resistant Escherichia coli and Klebsiella pneumoniae were detected in 4 (5.3%) and 32 (42.7%) of subjects respectively. CONCLUSION: In this longitudinal cohort study of infants living in a region with high endemic antibacterial resistance, we demonstrate that majority of the infants harboured several antibiotic resistance genes in their gut and showed that the infant gut resistome is diverse and dynamic over the first year of life.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Eczema/diagnóstico , Microbioma Gastrointestinal/efeitos dos fármacos , Aminoglicosídeos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Eczema/etiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/isolamento & purificação , Estudos Longitudinais , Masculino , Risco , beta-Lactamases/genética , beta-Lactamases/metabolismo , beta-Lactamas/farmacologia
19.
Nucleic Acids Res ; 48(8): 4357-4370, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32232417

RESUMO

The Klebsiella pneumoniae species complex includes important opportunistic pathogens which have become public health priorities linked to major hospital outbreaks and the recent emergence of multidrug-resistant hypervirulent strains. Bacterial virulence and the spread of multidrug resistance have previously been linked to toxin-antitoxin (TA) systems. TA systems encode a toxin that disrupts essential cellular processes, and a cognate antitoxin which counteracts this activity. Whilst associated with the maintenance of plasmids, they also act in bacterial immunity and antibiotic tolerance. However, the evolutionary dynamics and distribution of TA systems in clinical pathogens are not well understood. Here, we present a comprehensive survey and description of the diversity of TA systems in 259 clinically relevant genomes of K. pneumoniae. We show that TA systems are highly prevalent with a median of 20 loci per strain. Importantly, these toxins differ substantially in their distribution patterns and in their range of cognate antitoxins. Classification along these properties suggests different roles of TA systems and highlights the association and co-evolution of toxins and antitoxins.


Assuntos
Evolução Molecular , Klebsiella pneumoniae/genética , Sistemas Toxina-Antitoxina/genética , Simulação por Computador , Farmacorresistência Bacteriana/genética , Genoma Bacteriano , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/patogenicidade , Fenótipo , Fatores de Virulência/genética
20.
Zhonghua Liu Xing Bing Xue Za Zhi ; 41(3): 423-428, 2020 Mar 10.
Artigo em Chinês | MEDLINE | ID: mdl-32294847

RESUMO

Objective: To investigate the isolation rate, antimicrobial resistance phenotype, and molecular type characteristics of Klebsiella pneumoniae from infectious diarrhea outpatients in Tai'an. Methods: A total of 866 stool samples were collected from infectious diarrhea cases in sentinel hospitals in 6 counties of Tai'an from 2013 to 2017. The strains were isolated from stool samples of the cases and identified by biochemical test. Micro broth dilution method was used to detect the drug resistance of the strains. The molecular typing was conducted by using pulsed field gel electrophoresis (PFGE). Results: The detection rate of Klebsiella pneumoniae in the stool samples was 7.97% (69/866), with significant differences among the 6 counties (χ(2)=39.627, P=0.000). Sixty- eight out of the 69 strains were resistant to 15 antibiotics with resistance rate 98.55%(68/69). The resistance to ampicillin (AMP) was highest (84.06%) (58/69), followed by sulfamethoxazole (SOX) (72.46%)(50/69). There were 40 drug resistance profiles, and the predominant resistance profile was AMP-SOX detected (n=10). The multi-drug resistant (MDR) strains accounted for 33.33% (23/69). The 69 strains could be divided into 65 PFGE patterns, and no predominant PFGE pattern or cluster was observed. Conclusions: Klebsiella pneumoniae was detected in the stool samples of diarrhea- syndrome outpatients, indicating the risk for community-acquired infection; the strains were resistant to multiplex antibiotics, with wide drug-resistance profiles and high multi-drug resistance rates. The PFGE patterns were diverse, which showed no correlation with drug resistance profiles. Our study indicated that it necessary to strengthen the surveillance and detection of Klebsiella pneumoniae from diarrhea outpatients, which could facilitate the prevention of the emergence and spread of drug resistance strains and the protection of susceptible population.


Assuntos
Farmacorresistência Bacteriana , Disenteria/microbiologia , Infecções por Klebsiella/diagnóstico , Klebsiella pneumoniae , Pacientes Ambulatoriais/estatística & dados numéricos , Antibacterianos/farmacologia , China , Eletroforese em Gel de Campo Pulsado , Humanos , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Tipagem Molecular
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