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1.
J Med Microbiol ; 69(1): 82-86, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31904319

RESUMO

In recent years, Serratia marcescens has emerged as an important agent of hospital-acquired infections, such as pneumonia, urinary tract infection, septicaemia and meningitis, particularly in vulnerable patients. Compared to Klebsiella pneumoniae and Escherichia coli, S. marcescens is less commonly associated with bla KPC genes, yet few cases of plasmid transmission at the gastrointestinal level from K. pneumoniae carbapenemase (KPC)-producing Enterobacterales to S. marcescens have been described. Here we report a case of in vivo acquisition, during a 3-month period of hospitalization in the intensive care unit, of a bla KPC-3 gene carried by a pKpQIL-IT plasmid, and its probable transmission at the bronchial level among different species of Enterobacterales, including K. pneumoniae and S. marcescens. By using whole genome sequence analyses we were able provide insight into the dynamics of carbapenem-resistance determinants acquisition in the lower respiratory tract, a novel anatomical region for such plasmid transmission events, that usually involve the gastrointestinal tract. The co-presence at the same time of both wild-type and resistant Enterobacterales could have been the critical factor leading to the spread of plasmids harbouring carbapenem-resistance genes, of particular importance during surveillance screenings. The possibility of such an event may have significant consequences in terms of antimicrobial treatment, with a potential limitation of therapeutic options, thereby further complicating the clinical management of high-risk critically ill patients.


Assuntos
Proteínas de Bactérias/genética , Transferência Genética Horizontal , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Plasmídeos , Serratia marcescens/enzimologia , Serratia marcescens/genética , beta-Lactamases/genética , Adulto , Infecção Hospitalar/microbiologia , Humanos , Unidades de Terapia Intensiva , Infecções por Klebsiella/microbiologia , Masculino , Infecções Respiratórias/microbiologia , Infecções por Serratia/microbiologia , Sequenciamento Completo do Genoma
2.
Infect Immun ; 88(1)2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31611270

RESUMO

Antibiotic-resistant Klebsiella pneumoniae isolates constitute a great clinical challenge. One important resistance mechanism in K. pneumoniae is the metallo-ß-lactamases (MBLs), which require zinc for their function. Thus, zinc chelation could be a strategy to resensitize K. pneumoniae to ß-lactams. However, the potential role for endogenous zinc chelators for this purpose remains to be explored. The aim was to search for endogenous factors that could resensitize MBL-expressing K. pneumoniae to cefotaxime (CTX). Clinical K. pneumoniae isolates expressing different MBLs were screened for sensitivity to CTX in supernatants from human HT-29 colonic epithelial cells. Factors influencing CTX susceptibility were isolated and identified with chromatographic and biochemical methods. Free zinc was measured with a Zinquin assay, the thiol content was assessed with a fluorometric thiol assay, and the reducing ability of the supernatant was measured with a fluorescent l-cystine probe. Urine samples from healthy volunteers were used to validate findings ex vivo VIM-1-expressing K. pneumoniae regained susceptibility to CTX when grown in supernatants from HT-29 cells. This effect was mediated via free thiols in the supernatant, including l-cysteine, and could be prevented by inhibiting thioredoxin reductase activity in the supernatant. Free thiols in urine samples appeared to have a similar function in restoring CTX activity against VIM-1-expressing K. pneumoniae in a zinc-dependent manner. We have identified l-cysteine as an endogenous zinc chelator resulting in the resensitization of VIM-1-expressing K. pneumoniae to CTX. These results suggest that natural zinc chelators in combination with conventional antibiotics could be used to treat infections caused by VIM-1-expressing pathogens.


Assuntos
Antibacterianos/farmacologia , Cefotaxima/farmacologia , Quelantes/metabolismo , Klebsiella pneumoniae/enzimologia , Compostos de Sulfidrila/metabolismo , Zinco/metabolismo , beta-Lactamases/metabolismo , Células HT29 , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Resistência beta-Lactâmica
3.
Ann Agric Environ Med ; 26(3): 405-408, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31559794

RESUMO

INTRODUCTION: Carbapenemase-producing Enterobacteriaceae have spread rapidly through the countries and continents to become a global concern. One of the main reservoirs of NDM-1 positive strains from the Enterobacteriaceae family is the Indian subcontinent (Bangladesh, Pakistan, India). MATERIAL AND METHODS: During June 2017 - June 2018, rectal swab samples were collected routinely in all patients returning to Poland from South and South-East Asia. During molecular examinations gene blaNDM-1 encoding NDM-1 carbapenemase was detected. RESULTS: 31 patients were examined after returning to Poland from a trip to South and South-East Asia. The presence of New Delhi Metallo-ß-lactamase-1 producing Escherichia coli and Klebsiella pneumoniae was confirmed in three patients (9.7%) returning to Poland from travels to India. All the positive patients were hospitalized during the trip in a New Delhi hospital. CONCLUSIONS: Digestive tract carriage of NDM in a group of Polish travelers is a significant health and epidemiological problem. The study confirms the necessity for screening for carbapenemase-producing Enterobacteriaceae (CPE), particularly among travellers. Rectal swabs should be collected in every case of patients returning from international trips, and the possibility of environment-associated infections should be emphasized.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/enzimologia , Klebsiella pneumoniae/enzimologia , Viagem , beta-Lactamases/metabolismo , Adulto , Proteínas de Bactérias/genética , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Feminino , Humanos , Índia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Polônia , beta-Lactamases/genética
4.
Lett Appl Microbiol ; 69(5): 333-338, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31536642

RESUMO

Due to increasing antibiotic resistance Klebsiella pneumoniae is a serious threat for the hospitalized patients. The aim of this study was the assessment of radiant catalytic ionization (RCI) efficacy on K. pneumoniae reduction in the air and on selected surfaces. Four K. pneumoniae NDM and ESBLs-producing strains were included in the study. Three types of surface were tested: cotton-polyester, terry and PVC. It was found that RCI significantly reduced the number of bacteria from all types of surface (terry: 0·56-1·22 log CFU m2 , cotton-polyester: 2·15-3·71 log CFU per m2 , PVC: 4·45-4·92 log CFU per m2 ) as well as from the air (1·80 log CFU per m3 ). The RCI technology may be a useful disinfection method in hospitals. SIGNIFICANCE AND IMPACT OF THE STUDY: Microbial contamination of air and surfaces in hospitals play an important role in healthcare-associated infections. The aim was the assessment of Klebsiella pneumoniae elimination using radiant catalytic ionization (RCI). K. pneumoniae are aetiological agent of nosocomial infections, such as: pneumonia, infections of urinary tract, blood, e.t.c. The strains producing the New Delhi metallo-ß-lactamases are one of the greatest epidemiological threat. The use of RCI eliminate the tested bacteria from the hospital environment, but can also be effective in food processing plants or public facilities, ensuring the safety of people and products. This research is scarce in references and has a large innovation and application potential.


Assuntos
Proteínas de Bactérias/metabolismo , Infecção Hospitalar/prevenção & controle , Infecções por Klebsiella/prevenção & controle , Klebsiella pneumoniae/efeitos da radiação , beta-Lactamases/metabolismo , Microbiologia do Ar , Proteínas de Bactérias/genética , Infecção Hospitalar/microbiologia , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/crescimento & desenvolvimento , Viabilidade Microbiana/efeitos da radiação , Radiação Ionizante
5.
Org Biomol Chem ; 17(37): 8571-8588, 2019 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-31517368

RESUMO

Ketoreductase from growing cells of Klebsiella pneumoniae (NBRC 3319) acts as an efficient reagent for converting racemic α-benzyl/cinnamyl substituted-ß-ketoesters to the corresponding ß-hydroxy esters with excellent yields and stereoselectivities (ee and de >99 %). The reactions described herein followed a biocatalytic dynamic kinetic reductive resolution (DKRR) pathway, which is reported for the first time with such substrates. It was found that the enzyme system can accept substituted mono-aryl rings with different electronic natures. In addition, it also accepts a substituted naphthyl ring and heteroaryl ring in the α-position of the parent ß-ketoester. The synthesized enantiopure ß-hydroxy esters were then synthetically manipulated to valuable tetrahydropyran building blocks.


Assuntos
Klebsiella pneumoniae/enzimologia , Oxirredutases/metabolismo , Piranos/metabolismo , Termodinâmica , Biocatálise , Cinética , Estrutura Molecular , Oxirredução , Piranos/química
6.
Acta Crystallogr D Struct Biol ; 75(Pt 9): 792-803, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31478902

RESUMO

Klebsiella pneumoniae pullulanase (KPP) belongs to glycoside hydrolase family 13 subfamily 13 (GH13_13) and is the only enzyme that is reported to perform an induced-fit motion of the active-site loop (residues 706-710). Comparison of pullulanase structures indicated that only KPP has Leu680 present behind the loop, in contrast to the glycine found in other GH13_13 members. Analysis of the structure and activity of recombinant pullulanase from K. pneumoniae ATCC 9621 (rKPP) and its mutant (rKPP-G680L) indicated that the side chain of residue 680 is important for the induced-fit motion of the loop 706-710 and alters the binding affinity of the substrate.


Assuntos
Proteínas de Bactérias/química , Glicosídeo Hidrolases/química , Klebsiella pneumoniae/enzimologia , Proteínas Recombinantes/química , Domínio Catalítico , Estrutura Terciária de Proteína
7.
Indian J Med Res ; 149(4): 528-538, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31411177

RESUMO

Background & objectives: The global spread of carbapenem-resistant Enterobacteriaceae (CRE) is an emerging clinical problem. Hence, in this study, the plausible role of extended-spectrum beta-lactamases (ESBLs)/carbapenemases, OmpC/Ompk36, acrB and their combinations was explored among CRE. Methods: The minimum inhibitory concentration (MIC) of meropenem, enzyme-phenotypes (ESBLs/IR and metallo-beta-lactamase (MBL)/non-MBL carbapenemase), genotypes (blaTEM, blaSHV and blaCTX-M; blaNDM and blaVIM; blaKPC and blaOXA-48-like variants), acrB and outer membrane protein (OMP) expressions were analyzed with a total of 101 non-duplicate clinical isolates, obtained from various samples of patients visiting two tertiary care units of Eastern India during May 2013 - October 2016. This included Escherichia coli (n=36) and Klebsiella pneumoniae (n=65), categorized into two groups, namely Group I (resistant to all carbapenems; n=93; E. coli=34 and Klebsiella spp.=59) and Group II (non-resistant to all the carbapenems; n=8; E. coli=2 and Klebsiella spp.=6). Results: Though 88.17 per cent of Group I isolates exhibited ESBL property, the presence of carbapenemase activity (70.96%) and that of blaNDM gene (42/66: 63.63%) indicated their contributions towards the emergence of CRE. Further, porin loss and/or efflux pump activation among ESBL/carbapenemase-producing isolates heightened the MIC of meropenem from 64 to 256 mg/l (range exhibited by only ESBL/carbapenemase-producing isolates) to >256 mg/l. Interpretation & conclusions: These findings implied the major contribution of porin loss and/or efflux pump activation over the presence of ESBLs/carbapenemases in imparting carbapenem resistance in pathogenic bacteria.


Assuntos
Proteínas de Bactérias/genética , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Klebsiella/tratamento farmacológico , Porinas/genética , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/patogenicidade , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Feminino , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Humanos , Infecções por Klebsiella/genética , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidade , Masculino , beta-Lactamases/genética
8.
PLoS Pathog ; 15(8): e1008010, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31449551

RESUMO

Klebsiella pneumoniae (Kp), one of the most common causes of healthcare-associated infections, increases patient morbidity, mortality, and hospitalization costs. Kp must acquire nutrients from the host for successful infection; however, the host is able to prevent bacterial nutrient acquisition through multiple systems. This includes the innate immune protein lipocalin 2 (Lcn2), which prevents Kp iron acquisition. To identify novel Lcn2-dependent Kp factors that mediate evasion of nutritional immunity during lung infection, we undertook an InSeq study using a pool of >20,000 transposon mutants administered to Lcn2+/+ and Lcn2-/- mice. Comparing transposon mutant frequencies between mouse genotypes, we identified the Kp citrate synthase, GltA, as potentially interacting with Lcn2, and this novel finding was independently validated. Interestingly, in vitro studies suggest that this interaction is not direct. Given that GltA is involved in oxidative metabolism, we screened the ability of this mutant to use a variety of carbon and nitrogen sources. The results indicated that the gltA mutant has a distinct amino acid auxotrophy rendering it reliant upon glutamate family amino acids for growth. Deletion of Lcn2 from the host leads to increased amino acid levels in bronchioloalveolar lavage fluid, corresponding to increased fitness of the gltA mutant in vivo and ex vivo. Accordingly, addition of glutamate family amino acids to Lcn2+/+ bronchioloalveolar lavage fluid rescued growth of the gltA mutant. Using a variety of mouse models of infection, we show that GltA is an organ-specific fitness factor required for complete fitness in the spleen, liver, and gut, but dispensable in the bloodstream. Similar to bronchioloalveolar lavage fluid, addition of glutamate family amino acids to Lcn2+/+ organ lysates was sufficient to rescue the loss of gltA. Together, this study describes a critical role for GltA in Kp infection and provides unique insight into how metabolic flexibility impacts bacterial fitness during infection.


Assuntos
Citrato (si)-Sintase/metabolismo , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/crescimento & desenvolvimento , Lipocalina-2/metabolismo , Lipocalina-2/fisiologia , Animais , Citrato (si)-Sintase/genética , Modelos Animais de Doenças , Humanos , Infecções por Klebsiella/metabolismo , Klebsiella pneumoniae/enzimologia , Lipocalina-2/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
9.
Acta Microbiol Immunol Hung ; 66(3): 367-376, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31438725

RESUMO

The aim of the study was to find out the carbapenem resistance rate and prevalence of different carbapenemase genes in Klebsiella pneumoniae and Escherichia coli from a North Indian corporate hospital that receives both Indian and international patients. A total of 528 clinical isolates of E. coli and K. pneumoniae were included in the study. All isolates that were found resistant to carbapenems by MIC testing (Vitek II Compact®) were screened for NDM, OXA-48, VIM, and KPC genes by PCR. Sequencing of NDM gene and transmissibility by conjugation assay were checked on 22 randomly selected NDM-positive isolates. One hundred and fifty-six isolates (29.54%) were carbapenem-resistant. The rate of carbapenem resistance was significantly higher in K. pneumoniae as compared to E. coli (53.9% vs. 15.6%; p < 0.05). The NDM gene was found in 34.6% (54/156), OXA-48 in 31.4% (49/156), co-expression of NDM + OXA-48 in 15.3% (24/156) of the carbapenem-resistant isolates. VIM and KPC were absent in all isolates. NDM gene was significantly more prevalent in E. coli than K. pneumoniae (p < 0.05). All the tested isolates formed transconjugants and NDM-5 was the most common variant in both species (15/22). The presence of plasmid-based NDM calls for stricter surveillance measures in our hospital settings.


Assuntos
Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Escherichia coli/isolamento & purificação , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/isolamento & purificação , beta-Lactamases/genética , Antibacterianos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Carbapenêmicos/farmacologia , Conjugação Genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Infecções por Escherichia coli/epidemiologia , Feminino , Humanos , Índia/epidemiologia , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Plasmídeos/análise , Prevalência , Análise de Sequência de DNA
10.
Chin Med J (Engl) ; 132(16): 1894-1902, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31408445

RESUMO

BACKGROUND: Extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) are the important pathogens causing pneumonia. This study aimed to investigate the clinical characteristics and molecular epidemiology of ESBL-producing E. coli and K. pneumoniae causing pneumonia at a large teaching hospital in China. METHODS: We collected patient's clinical data and ESBL-producing E. coli and K. pneumoniae strains causing pneumonia (from December 2015 to June 2016) at a hospital in Wuhan. The susceptibilities, multi-locus sequence typing, homologous analysis, ESBL genes by polymerase chain reaction and sequencing were determined. RESULTS: A total of 59 ESBL-producing strains (31 E. coli and 28 K. pneumoniae) isolated from patients with pneumonia were analyzed. The majority of strains were isolated from patients were with hospital-acquired pneumonia (37/59, 62.7%), followed by community-acquired pneumonia (13/59, 22.0%), and ventilator-related pneumonia (9/59, 15.3%). The E. coli ST131 (9 isolates, 29.0%) and K. pneumoniae ST11 (5 isolates, 17.9%) were the predominant sub-types. The most prevalent ESBL gene was CTX-M-14, followed by SHV-77, CTX-M-3, SHV-11, and CTX-M-27. At least 33 (55.9%) of the ESBL-producing strains carried two or more ESBL genes. The ISEcp1 and IS26 were found upstream of all blaCTX-M (CTX-Ms) and of most blaSHV (SHVs) (57.6%), respectively. Moreover, three ESBL-producing K. pneumoniae ST11 strains which were resistant to carbapenems carried the blaNDM-1 and blaKPC-2, two of which also bearing blaOXA-48 were resistant to all antibiotics (including Tigecycline). CONCLUSIONS: Hospital-acquired pneumonia is more likely correlated with ESBL-producing E. coli and K. pneumoniae. ESBL-producing E. coli ST131 and multi-drug resistance ESBL-producing, as well as New Delhi metallo-ß-lactamase-1 (NDM-1) and Klebsiella pneumoniae carbapenemases-2 (KPC-2) bearing K. pneumoniae ST11 are spreading in patients with pneumonia in hospital.


Assuntos
Escherichia coli/enzimologia , Escherichia coli/patogenicidade , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/patogenicidade , Pneumonia/epidemiologia , Pneumonia/microbiologia , beta-Lactamases/metabolismo , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/transmissão , Humanos , Infecções por Klebsiella/transmissão , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase , beta-Lactamases/genética
11.
BMC Infect Dis ; 19(1): 611, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299943

RESUMO

BACKGROUND: Bloodstream infections (BSI) due to Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-Kp) have become an important problem and they are associated with a high mortality rate. The aim of our study was to evaluate the clinical and epidemiological characteristics of KPC-Kp from BSIs. METHODS: In this retrospective cohort study, conducted in a tertiary referral center in Italy, 112 patients with KPC-Kp BSIs diagnosed between February 2011 and December 2015 were identified. We evaluated the mortality at 30 days from the first positive blood culture. Survivor and non-survivor subgroups were compared to identify predictors of mortality. RESULTS: The overall crude mortality was 35%. APACHE II score ≥ 15, septic shock at BSI onset, immunosuppressive therapy during the 30 days before the BSI onset, and the lack of a combination therapy with at least 2 active drugs emerged as independent predictors of mortality. Excluding patients with inadequate therapy, the mortality decreased to 25% while an APACHE II score ≥ 15 and the presence of septic shock remained independently associated with a negative outcome. Two different pulsotypes were identified: pulsotype A belonged to ST512 and carried KPC-3 and pulsotype B belonged to ST307 and carried KPC-2. CONCLUSIONS: This study confirmed a high mortality rate of KPC-Kp BSIs. The outcome is heavily influenced by the patient's clinical conditions. A therapeutic approach including a combination with at least two active drugs in vitro can improve the prognosis, unless patients received an appropriate therapy.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Klebsiella/diagnóstico , Klebsiella pneumoniae/enzimologia , beta-Lactamases/metabolismo , Adulto , Idoso , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana/genética , Feminino , Humanos , Itália/epidemiologia , Estimativa de Kaplan-Meier , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/mortalidade , Klebsiella pneumoniae/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença , Choque Séptico/complicações , Choque Séptico/diagnóstico , Centros de Atenção Terciária
12.
Eur J Clin Microbiol Infect Dis ; 38(10): 1925-1931, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31278562

RESUMO

Combination therapies are frequently used in the treatment of multidrug-resistant Klebsiella pneumoniae infection without consensus regarding which combination is the most effective. We compared bactericidal titres from sera collected from critically ill patients receiving meropenem plus tigecycline (n = 5), meropenem plus colistin (n = 5), or meropenem, colistin and tigecycline (n = 5) against K. pneumoniae isolates that included ESBL-producing (n = 7) and KPC-producing strains (n = 14) with varying sensitivity patterns to colistin and tigecycline. Meropenem concentrations (Cmin) were measured in all samples by LC-MS/MS, and indexed to respective pathogen MICs to explore differences in patterns of bactericidal activity for two versus three drug combination regimens. All combination regimens achieved higher SBTs against ESBL (median reciprocal titre 128, IQR 32-256) versus KPC (4, IQR 2-32) strains. Sera from patients treated with meropenem-colistin yielded higher median SBTs (256, IQR 64-512) than either meropenem-tigecycline (32, IQR 8-256; P < 0.001). The addition of tigecycline was associated with a lower probability of achieving a reciprocal SBT above 8 when meropenem concentrations were below the MIC (P = 0.04). Although the clinical significance is unknown, sera from patients receiving tigecycline-based combination regimens produce lower serum bactericidal titres against ESBL or KPC-producing K. pneumoniae. SBTs may represent a useful complimentary endpoint for comparing pharmacodynamics of combinations regimens for MDR Enterobacteriaceae.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae/efeitos dos fármacos , Meropeném/administração & dosagem , Meropeném/farmacocinética , beta-Lactamases/metabolismo , Idoso , Cromatografia Líquida , Colistina/administração & dosagem , Estado Terminal , Quimioterapia Combinada/métodos , Feminino , Humanos , Klebsiella pneumoniae/enzimologia , Masculino , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Pessoa de Meia-Idade , Soro/química , Espectrometria de Massas em Tandem , Tigeciclina/administração & dosagem
13.
Zoonoses Public Health ; 66(6): 603-617, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31264805

RESUMO

OBJECTIVES: This study investigates the frequency and characteristics of carbapenemase-producing Escherichia coli/Klebsiella pneumoniae (CPE/K) and extended-spectrum cephalosporinase-producing E. coli/K. pneumoniae (ESCE/K) in healthy humans and livestock in rural Cambodia. Additionally, household practices as risk factors for faecal carriage of ESCE/K are identified. METHODS: Faecal samples were obtained from 307 humans and 285 livestock including large ruminants, pigs and poultry living in 100 households in rural Cambodia in 2011. Each household was interviewed, and multilevel logistic model determined associations between household practices/meat consumption and faecal carriage of ESCE/K. CPE and ESCE/K were detected and further screened for colistin resistance genes. RESULTS: CPE/K isolates harbouring blaOXA-48 were identified in two humans. The community carriage of ESCE/K was 20% in humans and 23% in livestock. The same ESBL genes: blaCTX-M-15 , blaCTX-M-14 , blaCTX-M-27 , blaCTX-M-55 , blaSHV-2 , blaSHV-12 , blaSHV-28 ; AmpC genes: blaCMY-2 , blaCMY-42, blaDHA-1 ; and colistin resistance genes: mcr-1-like and mcr-3-like were detected in humans and livestock. ESCE/K was frequently detected in women, young children, pigs and poultry, which are groups in close contact. The practice of burning or burying meat waste and not collecting animal manure indoors and outdoors daily were identified as risk factors for faecal carriage of ESCE/K. CONCLUSIONS: Faecal carriage of E. coli and K. pneumoniae harbouring extended-spectrum cephalosporinase genes are common in the Cambodian community, especially in women and young children. Exposure to animal manure and slaughter products are risk factors for intestinal colonization of ESCE/K in humans.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Cefalosporinase/metabolismo , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/metabolismo , Adolescente , Adulto , Animais , Proteínas de Bactérias/genética , Camboja , Cefalosporinase/genética , Criança , Pré-Escolar , Colistina/farmacologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/enzimologia , Fezes/microbiologia , Feminino , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Humanos , Lactente , Klebsiella pneumoniae/enzimologia , Gado/microbiologia , Masculino , Fatores de Risco , População Rural , Zoonoses , beta-Lactamases/genética
14.
BMC Infect Dis ; 19(1): 565, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253101

RESUMO

BACKGROUND: To detect carbapenemase-producing Gram-negative bacteria in bacterial laboratories at medical settings, a new immunochromatographic assay for New Delhi metallo-ß-lactamases (NDMs) was developed. METHODS: The immunochromatographic assay for New Delhi metallo-ß-lactamases producers was developed using rat monoclonal antibodies against NDMs. The assessment was performed using 350 isolates of Gram-negative bacteria, including Acinetobacter baumannii (51 isolates), Enterobacteriaceae (163 isolates), and Pseudomonas aeruginosa (136 isolates) obtained from 2015 to 2017 in medical settings in Myanmar. Of them, 302 isolates were resistant to carbapenems, including imipenem and/or meropenem. The blaNDM genes were identified by PCR and sequencing. RESULTS: Of the 350 clinical isolates tested, 164 (46.9%) (60 isolates of Escherichia coli, 51 isolates of Klebsiella pneumoniae, 25 isolates of Enterobacter cloacae, 23 isolates of P. aeruginosa, and 5 isolates of A. baumannii) were positive on this assay, and all the positive isolates harbored genes encoding NDM-1, - 4, - 5 and - 7. The remaining 186 (53.1%) isolates negative on the assay did not harbor genes encoding NDMs. The assay had a specificity of 100% and a sensitivity of 100%. The assessment revealed that more than 90% of carbapenem-resistant Enterobacteriaceae produced NDMs. CONCLUSIONS: The immunochromatographic assay is an easy-to-use and reliable kit for detection of NDMs-producing Gram-negative bacteria. The assay revealed that NDM-producing Enterobacteriaceae isolates are wide-spread in medical settings in Myanmar.


Assuntos
Bactérias Gram-Negativas/isolamento & purificação , Imunoensaio/métodos , beta-Lactamases/imunologia , Acinetobacter baumannii/enzimologia , Acinetobacter baumannii/isolamento & purificação , Animais , Antibacterianos/farmacologia , Anticorpos Monoclonais/imunologia , Farmacorresistência Bacteriana , Enterobacteriaceae/enzimologia , Enterobacteriaceae/isolamento & purificação , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/genética , Humanos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Mianmar , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/isolamento & purificação , Ratos , beta-Lactamases/genética , beta-Lactamases/metabolismo
15.
Eur J Clin Microbiol Infect Dis ; 38(9): 1687-1691, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31165962

RESUMO

The aim of this study was to analyze the alarming spread of NDM-1- and OXA-48-co-producing Klebsiella pneumoniae clinical isolates, collected between October 2016 and January 2018 in a neonatal intensive care unit of the University Hospital, Catania, Italy, through whole genome sequencing. All confirmed carbapenem-resistant K. pneumoniae (CRKp) isolates were characterized pheno- and geno-typically, as well as by whole genome sequencing (WGS). A total of 13 CRKp isolates were identified from 13 patients. Pulsed-field gel electrophoresis (PFGE) was performed, and the multilocus sequence typing (MLST) scheme used was based on the gene sequence as published on the MLST Pasteur website. Core genome MLST (cgMLST) was also performed. All isolates co-carried blaoxa-48 and blaNDM-1 genes located on different plasmids belonging to the IncM/L and IncA/C2 groups, respectively. The 13 strains had identical PFGE profiles. MLST and cgMLST showed that K. pneumoniae was dominated by CRKp ST101 and two novel STs (ST3666 and ST3367), identified after submission to the MLST database for ST assignment. All isolates shared the same virulence factors such as type 3 fimbriae, genes for yersiniabactin biosynthesis, yersiniabactin receptor, and iron ABC transporter. They carried the wzi137 variant associated with the K17 serotype. To the best of our knowledge, this is the first report of two novel STs, 3366 and 3367, NDM-OXA-48-co-producing K. pneumoniae clinical isolates, in Italy.


Assuntos
Antibacterianos/farmacologia , Klebsiella pneumoniae/genética , beta-Lactamases/genética , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Carbapenêmicos/farmacologia , Surtos de Doenças , Eletroforese em Gel de Campo Pulsado , Humanos , Recém-Nascido , Terapia Intensiva Neonatal , Itália , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Sequenciamento Completo do Genoma
16.
Int J Antimicrob Agents ; 54(2): 233-239, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31173865

RESUMO

Here we describe an outbreak due to NDM-1+CTX-M-15+DHA-1-producing Klebsiella pneumoniae (NDM-1-Kp) in Spain related to a patient previously admitted to a healthcare centre in an endemic area (Pakistan). Nine colonised patients were detected in the Neurosurgery ward between September 2015 and February 2016 during the R-GNOSIS European Project. NDM-1-Kp isolates from clinical samples were also recovered in three of these patients. Surveillance culture at admission was negative in the index case, but NDM-1-Kp colonisation was detected 27 days later after receiving antibiotic treatment. Co-colonisation with a second NDM-1-Kp isolate was identified in this patient 61 days post-admission. Overall length of stay (LOS = 75 days) (P < 0.01) and LOS until carbapenemase detection (LOS-1 = 36 days) was longer in NDM-1-Kp carriers than in patients with other carbapenemase-producing Enterobacterales. Intervention strategies were implemented after the outbreak declaration and NDM-1-Kp transmission was contained. Among the NDM-1-Kp isolates, two clones [ST437 (index case and Patient 2) and ST101 (index case and Patients 3-9)] with different IncFIB NDM-1-containing plasmids were identified. Whole-genome sequencing revealed a high content of antimicrobial resistance genes in both isolates in addition to a large number of virulence factors. Colonisation with other epidemic (OXA-48-ST11-K. pneumoniae and VIM-1-ST54-K. pneumoniae) and non-epidemic (VIM-1-ST908-K. pneumoniae and VIM-ST431-Escherichia coli) clones was also detected in two NDM-1 carriers. Implementation of adequate infection control measures and uninterrupted active surveillance programmes for detecting patients with a low colonisation status are crucial to prevent the introduction and dissemination of NDM-type enzymes in our region.


Assuntos
Proteínas de Bactérias/análise , Doenças Transmissíveis Importadas/epidemiologia , Surtos de Doenças , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/enzimologia , beta-Lactamases/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/genética , Doenças Transmissíveis Importadas/microbiologia , Doenças Transmissíveis Importadas/transmissão , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , Transmissão de Doença Infecciosa , Feminino , Humanos , Controle de Infecções , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/transmissão , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Paquistão , Espanha/epidemiologia , Viagem , beta-Lactamases/genética
17.
Future Microbiol ; 14: 691-704, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31148474

RESUMO

Aim: To determine the prevalence of New Delhi metallo-ß-lactamase (NDM)-producing Gram-negative pathogens isolated from children's samples. Materials & methods: Carbapenem-resistant clinical isolates (n = 117) were confirmed by VITEK® 2 compact system, matrix-assisted laser desorption ionization-time of flight and multilocus sequence typing. MIC (µg/ml) of various antibiotics was determined by VITEK 2 compact system. Molecular characterization of the isolates was performed by PCR, DNA sequencing, PFGE and DNA hybridization. Results: Out of 117 carbapenemase producers, 37 (31.6%) and 29 (24.7%) were Klebsiella pneumoniae and Acinetobacter baumannii, respectively. 72 (61.5%) isolates were NDM positive and among these 60, 9 and 3 were NDM-1, -5 and -7, respectively. Majority of the NDM-producing K. pneumoniae belonged to ST11 and ST273 while most of the Escherichia coli belonged to ST405 and ST101. blaNDM were mainly located on 150kb plasmids. MIC displayed high resistance against ß-lactams drugs including carbapenems, and the most sensitive drugs were tigecycline and colistin. Conclusion: Dissemination of blaNDM-producing pathogens, particularly in children clinical settings, is a matter of great public health concern.


Assuntos
Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/genética , beta-Lactamases/biossíntese , beta-Lactamases/genética , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/enzimologia , Acinetobacter baumannii/genética , Acinetobacter baumannii/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Criança , DNA Bacteriano/análise , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Feminino , Perfilação da Expressão Gênica , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Paquistão/epidemiologia , Plasmídeos , Análise de Sequência de DNA
18.
Artigo em Inglês | MEDLINE | ID: mdl-31179245

RESUMO

The emergence and spread of metallo-beta-lactamase-producing multidrug-resistant (MDR) Klebsiella pneumoniae is a serious public health threat, which is further complicated by the increased prevalence of colistin resistance. The link between antimicrobial resistance acquired by strains of Klebsiella and their unique metabolic capabilities has not been determined. Here, we reconstruct genome-scale metabolic models for 22 K. pneumoniae strains with various resistance profiles to different antibiotics, including two strains exhibiting colistin resistance isolated from Cairo, Egypt. We use the models to predict growth capabilities on 265 different sole carbon, nitrogen, sulfur, and phosphorus sources for all 22 strains. Alternate nitrogen source utilization of glutamate, arginine, histidine, and ethanolamine among others provided discriminatory power for identifying resistance to amikacin, tetracycline, and gentamicin. Thus, genome-scale model based predictions of growth capabilities on alternative substrates may lead to construction of classification trees that are indicative of antibiotic resistance in Klebsiella isolates.


Assuntos
Farmacorresistência Bacteriana Múltipla/genética , Genômica , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , beta-Lactamases/genética , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Colistina/farmacologia , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Egito , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/crescimento & desenvolvimento , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Fenótipo
19.
Biomed Res Int ; 2019: 9757625, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31179337

RESUMO

Carbapenemase-producing Enterobacteriaceae (CPE) are well known to cause many serious infections resulting in increasing mortality rate, treatment cost, and prolonged hospitalization. Among the widely recognized types of carbapenemases, New Delhi ß-lactamase (NDM) and Klebsiella pneumoniae carbapenemase (KPC) are the most important enzymes. However, in Vietnam, there are only scattered reports of CPE due to the lack of simple and affordable methods that are suitable to laboratory conditions. This study aims to survey the characteristics of carbapenem-resistant E. coli and K. pneumoniae (CR-E/K) at two hospitals in Southern Vietnam and perform some simple methods to detect the two enzymes. A total of 100 CR-E/K strains were collected from clinical isolates of Gia Dinh People's Hospital and Dong Nai General Hospital, Vietnam, from November 2017 to May 2018. The patient-related information was also included in the analysis. We conducted real-time polymerase chain reaction (PCR), Modified Hodge Test (MHT), and combined disk test (CDT) on all isolates. Carbapenemase-encoding genes were detected in 47 isolates (36 NDM, 10 KPC, and one isolate harboring both genes). The E. coli strain carrying simultaneously these two genes was the first case reported here. Most of isolates were collected from patients in ICU, Infectious Disease Department, and Department of Urologic Surgery. Urine and sputum were two common specimens. The true positive rate (sensitivity, TPR) and specificity (SPC) of the imipenem-EDTA (ethylen diamine tetra acetic acid) for NDM detection and the imipenem-PBA (phenylboronic acid) for KPC detection on E. coli were 93.8%, 97.1% and 66.7%, 95.7%, respectively. Meanwhile, the imipenem-EDTA for NDM detection and the imipenem-PBA for KPC detection among K. pneumonia achieved 90.5%, 100% and 100%, 92.9% TPR and SPC, respectively. However, MHT showed low sensitivity and specificity. Our findings showed that CP-E/K were detected with high prevalence in the two hospitals. We suggest that CDT can be used as a low-priced and accurate method of detection.


Assuntos
Proteínas de Bactérias/genética , Infecções por Escherichia coli/genética , Escherichia coli , Infecções por Klebsiella/genética , Klebsiella pneumoniae , Reação em Cadeia da Polimerase , beta-Lactamases/genética , Estudos Transversais , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/enzimologia , Infecções por Escherichia coli/epidemiologia , Feminino , Humanos , Infecções por Klebsiella/enzimologia , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Masculino , Vietnã/epidemiologia , beta-Lactamases/metabolismo
20.
Int J Antimicrob Agents ; 54(2): 223-227, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31200021

RESUMO

Klebsiella pneumoniae is a common cause of urinary tract infections (UTIs). Nitrofurantoin (NIT), with high therapeutic concentrations in urine, is recommended as the first-line drug for both empiric treatment and chemoprophylaxis of UTIs. Although NIT resistance in K. pneumoniae is relatively high, the resistance mechanism is not well understood. This study collected a NIT-resistant K. pneumoniae [NRKP, minimum inhibitory concentration (MIC)=128 mg/L] and investigated the resistance mechanism. Addition of efflux pump inhibitors increased the susceptibility of NRKP to NIT (MIC decreased from 128 to 32 mg/L), implying the important role of efflux pumps in NIT resistance. Quantitative reverse transcriptase polymerase chain reaction analysis showed that NRKP had >100-fold increased expression of ramA, which was demonstrated to be caused by ramR mutation. Deletion of ramA led to a four-fold decrease in the MIC of NIT, and the expression levels of efflux pumps acrB and oqxB were downregulated by four- to seven-fold. Complementation of ramA restored both the MIC value and the expression level of acrB and oqxB in the ramA mutant strain. In order to confirm the role of acrB and oqxB in NIT resistance, gene knockout strains were constructed. Deletion of acrB or oqxB alone led to a four-fold decrease in the MIC of NIT, and deletion of acrB and oqxB simultaneously led to a 16-fold decrease in the MIC of NIT. These results demonstrate that AcrAB and OqxAB contribute to NIT resistance in K. pneumoniae.


Assuntos
Anti-Infecciosos Urinários/farmacologia , Farmacorresistência Bacteriana , Klebsiella pneumoniae/efeitos dos fármacos , Proteínas de Membrana Transportadoras/metabolismo , Nitrofurantoína/farmacologia , Anti-Infecciosos Urinários/metabolismo , Transporte Biológico Ativo , Deleção de Genes , Perfilação da Expressão Gênica , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Proteínas de Membrana Transportadoras/genética , Testes de Sensibilidade Microbiana , Nitrofurantoína/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Infecções Urinárias/microbiologia
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