Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23.160
Filtrar
1.
Nat Commun ; 12(1): 4188, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234121

RESUMO

Klebsiella pneumoniae is a leading cause of antimicrobial-resistant (AMR) healthcare-associated infections, neonatal sepsis and community-acquired liver abscess, and is associated with chronic intestinal diseases. Its diversity and complex population structure pose challenges for analysis and interpretation of K. pneumoniae genome data. Here we introduce Kleborate, a tool for analysing genomes of K. pneumoniae and its associated species complex, which consolidates interrogation of key features of proven clinical importance. Kleborate provides a framework to support genomic surveillance and epidemiology in research, clinical and public health settings. To demonstrate its utility we apply Kleborate to analyse publicly available Klebsiella genomes, including clinical isolates from a pan-European study of carbapenemase-producing Klebsiella, highlighting global trends in AMR and virulence as examples of what could be achieved by applying this genomic framework within more systematic genomic surveillance efforts. We also demonstrate the application of Kleborate to detect and type K. pneumoniae from gut metagenomes.


Assuntos
Proteínas de Bactérias/genética , Infecção Hospitalar/microbiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Tipagem Molecular/métodos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecção Hospitalar/diagnóstico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Conjuntos de Dados como Assunto , Farmacorresistência Bacteriana Múltipla/genética , Monitoramento Epidemiológico , Microbioma Gastrointestinal/genética , Genoma Bacteriano , Humanos , Lactente , Recém-Nascido , Infecções por Klebsiella/diagnóstico , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/patogenicidade , Metagenoma/genética , Epidemiologia Molecular/métodos , Mutação , Filogenia , Software , Virulência/genética , Fatores de Virulência/genética , Sequenciamento Completo do Genoma , beta-Lactamases/genética
2.
BMC Infect Dis ; 21(1): 683, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34261450

RESUMO

BACKGROUND: Third-generation cephalosporin-resistant Gram-negatives (3GCR-GN) and vancomycin-resistant enterococci (VRE) are common causes of multi-drug resistant healthcare-associated infections, for which gut colonisation is considered a prerequisite. However, there remains a key knowledge gap about colonisation and infection dynamics in high-risk settings such as the intensive care unit (ICU), thus hampering infection prevention efforts. METHODS: We performed a three-month prospective genomic survey of infecting and gut-colonising 3GCR-GN and VRE among patients admitted to an Australian ICU. Bacteria were isolated from rectal swabs (n = 287 and n = 103 patients ≤2 and > 2 days from admission, respectively) and diagnostic clinical specimens between Dec 2013 and March 2014. Isolates were subjected to Illumina whole-genome sequencing (n = 127 3GCR-GN, n = 41 VRE). Multi-locus sequence types (STs) and antimicrobial resistance determinants were identified from de novo assemblies. Twenty-three isolates were selected for sequencing on the Oxford Nanopore MinION device to generate completed reference genomes (one for each ST isolated from ≥2 patients). Single nucleotide variants (SNVs) were identified by read mapping and variant calling against these references. RESULTS: Among 287 patients screened on admission, 17.4 and 8.4% were colonised by 3GCR-GN and VRE, respectively. Escherichia coli was the most common species (n = 36 episodes, 58.1%) and the most common cause of 3GCR-GN infection. Only two VRE infections were identified. The rate of infection among patients colonised with E. coli was low, but higher than those who were not colonised on admission (n = 2/33, 6% vs n = 4/254, 2%, respectively, p = 0.3). While few patients were colonised with 3GCR- Klebsiella pneumoniae or Pseudomonas aeruginosa on admission (n = 4), all such patients developed infections with the colonising strain. Genomic analyses revealed 10 putative nosocomial transmission clusters (≤20 SNVs for 3GCR-GN, ≤3 SNVs for VRE): four VRE, six 3GCR-GN, with epidemiologically linked clusters accounting for 21 and 6% of episodes, respectively (OR 4.3, p = 0.02). CONCLUSIONS: 3GCR-E. coli and VRE were the most common gut colonisers. E. coli was the most common cause of 3GCR-GN infection, but other 3GCR-GN species showed greater risk for infection in colonised patients. Larger studies are warranted to elucidate the relative risks of different colonisers and guide the use of screening in ICU infection control.


Assuntos
Infecção Hospitalar , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli , Trato Gastrointestinal/microbiologia , Controle de Infecções , Unidades de Terapia Intensiva , Enterococos Resistentes à Vancomicina , Antibacterianos/farmacologia , Austrália/epidemiologia , Resistência às Cefalosporinas/genética , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Humanos , Controle de Infecções/métodos , Controle de Infecções/normas , Unidades de Terapia Intensiva/normas , Unidades de Terapia Intensiva/estatística & dados numéricos , Estudos Prospectivos , Enterococos Resistentes à Vancomicina/genética , Enterococos Resistentes à Vancomicina/isolamento & purificação
3.
BMC Infect Dis ; 21(1): 632, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34210275

RESUMO

BACKGROUND: Infection with Salmonella enterica usually results in diarrhea, fever, and abdominal cramps, but some people become asymptomatic or chronic carrier as a source of infection for others. This study aimed to analyze the difference in serotype, antimicrobial resistance, and genetic profiles between Salmonella strains isolated from patients and those from asymptomatic people in Nantong city, China. METHODS: A total of 88 Salmonella strains were collected from patients and asymptomatic people from 2017 to 2018. Serotyping, antimicrobial susceptibility testing, and PFGE analysis were performed to analyze the characteristics of these strains. RESULTS: Twenty serotypes belonging to 8 serogroups were identified in the 88 Salmonella strains. S. Typhimurium remained to be the predominant serotype in strains from both patients and asymptomatic people. Among the 27 strains from patients, S. Enteritidis and S. Rissen were shown as the other two major serotypes, while S. London, S. Derby, and S. Meleagridis were demonstrated as the other significant serotypes among the 61 strains from asymptomatic people. Antimicrobial resistance testing revealed that 84.1% of strains from both resources were multi-drug resistant. PFGE displayed a highly discriminative ability to differentiate strains belonging to S. Derby, S. Typhimurium, etc., but could not efficiently differentiate serotypes like S. Enteritidis. CONCLUSIONS: This study's results demonstrated that S. Typhimurium could cause human infection in both symptomatic and asymptomatic state; S. London, S. Derby, and S. Meleagridis usually cause asymptomatic infection, while S. Enteritidis infection mainly results in human diseases. The high multi-drug resistance rate detected in the antimicrobial resistance and diverse PFGE profiles of these strains implied that the strains were isolated from different sources, and the increased surveillance of Salmonella from both patients and asymptomatic people should be taken to control the disease.


Assuntos
Salmonella/classificação , Salmonella/genética , Salmonella/isolamento & purificação , Sorogrupo , Adolescente , Adulto , Idoso , Infecções Assintomáticas/epidemiologia , Criança , Pré-Escolar , China/epidemiologia , Farmacorresistência Bacteriana Múltipla , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Infecções por Salmonella/epidemiologia , Sorotipagem
4.
Molecules ; 26(11)2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34205065

RESUMO

Bacterial resistance to antibiotics due to increased efficiency of the efflux is a serious problem in clinics of infectious diseases. Knowledge of the factors affecting the activity of efflux pumps would help to find the solution. For this, fast and trustful methods for efflux analysis are needed. Here, we analyzed how the assay conditions affect the accumulation of efflux indicators ethidium (Et+) and tetraphenylphosphonium in Salmonella enterica ser. Typhimurium cells. An inhibitor phenylalanyl-arginyl-ß-naphtylamide was applied to evaluate the input of RND family pumps into the total efflux. In parallel to spectrofluorimetric analysis, we used an electrochemical assessment of Et+ concentration. The results of our experiments indicated that Et+ fluorescence increases immediately after the penetration of this indicator into the cells. However, when cells bind a high amount of Et+, the intensity of the fluorescence reaches the saturation level and stops reacting to the accumulated amount of this indicator. For this reason, electrochemical measurements provide more trustful information about the efficiency of efflux when cells accumulate high amounts of Et+. Measurements of Et+ interaction with the purified DNA demonstrated that the affinity of this lipophilic cation to DNA depends on the medium composition. The capacity of DNA to bind Et+ considerably decreases in the presence of Mg2+, Polymyxin B or when DNA is incubated in high ionic strength media.


Assuntos
DNA/química , Etídio/análise , Salmonella typhimurium/crescimento & desenvolvimento , Espermatozoides/química , Animais , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana Múltipla , Etídio/química , Masculino , Oniocompostos/química , Compostos Organofosforados/química , Salmão , Salmonella typhimurium/metabolismo , Espectrometria de Fluorescência , Espermatozoides/metabolismo
5.
BMC Genomics ; 22(1): 530, 2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-34247587

RESUMO

BACKGROUND: Acinetobacter baumannii is a common nosocomial pathogen that poses a huge threat to global health. Owing to the severity of A. baumannii infections, it became necessary to investigate the epidemiological characteristics of A. baumannii in Chinese hospitals and find the reasons for the high antibiotic resistance rate and mortality. This study aimed to investigate the epidemiologic and genetic characteristics of A. baumannii isolated from patients with hospital acquired pneumonia (HAP), bloodstream infection (BSI) and urinary tract infection (UTI) in China and uncover potential mechanisms for multi-drug resistance and virulence characteristics of A. baumannii isolates. RESULTS: All isolates were classified into two primary clades in core gene-based phylogenetic relationship. Clonal complex 208 (CC208) mainly consisted of ST195 (32 %) and ST208 (24.6 %). CC208 and non-CC208 isolates had carbapenem resistance rates of 96.2 and 9.1 %, respectively. Core genes were enriched in 'Amino acid transport and metabolism', 'Translation', 'Energy production and conversion', 'Transcription', 'Inorganic ion transport and metabolism' and 'Cell wall/membrane/envelope synthesis'. Most isolates possessed virulence factors related to polysaccharide biosynthesis, capsular polysaccharide synthesis and motility. Eleven isolates belong to ST369 or ST191 (oxford scheme) all had the virulence factor cap8E and it had a higher positive rate in UTI (35.3 %) than in BSI (18.9 %) and HAP (12.9 %). ABGRI1 antibiotic resistance islands were responsible for streptomycin, tetracycline and sulfonate resistance. The blaOXA-23 gene was the most probable cause for carbapenem resistance, although the blaOXA-66 gene with nonsynonymous SNPs (F82L, I129L) was not. CONCLUSIONS: A. baumannii is a genomically variable pathogen that has the potential to cause a range of infectious diseases. There is high proportion of carbapenem resistance in isolates from all three infection sites (HAP, BSI and UTI), which can be attributed to the blaOXA-23 gene. CC208 is the predominant clone in blaOXA-23-carrying A. baumannii that should be monitored. Virulence factors involving bacteria motility and polysaccharide biosynthesis which are widespread in clinical A. baumannii strains deserve our attention.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Doenças Transmissíveis , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , China/epidemiologia , Farmacorresistência Bacteriana Múltipla , Genômica , Humanos , Testes de Sensibilidade Microbiana , Filogenia , beta-Lactamases/genética
6.
J Med Microbiol ; 70(7)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34236300

RESUMO

Introduction. Outbreaks of carbapenem-resistant A. baumannii and A. nosocomialis have occurred worldwide in healthcare settings. Rapid and reliable molecular typing of bacterial isolates is vital for the effective surveillance of institutional outbreaks. The Pan-PCR and OXA-PCR assays are two multiplex PCR-based assays for the molecular typing of Acinetobacter species.Gap statement. However, few studies have investigated the discriminatory power of two multiplex PCR assays in in the genotyping of Acinetobacter species.Aim. We aimed to evaluate the efficacies of the Pan-PCR and OXA-PCR assays for molecular typing of A. baumannii and A. nosocomialis.Methodology. A total of 105 carbapenem-resistant A. baumannii isolates (CRABs) and 93 carbapenem-resistant A. nosocomialis isolates (CRANs) obtained from blood cultures were used for molecular typing by the Pan-PCR and OXA-PCR assays and two multilocus sequence typing (MLST) schemes.Results. The isolates were individually divided into 12 and 21 different sequence types via the Pasteur and Oxford MLST schemes, respectively. Additionally, these isolates were distinguished into 18 different types by the Pan-PCR and OXA-PCR assays. The results of the Pan-PCR and OXA-PCR assays distinguished CRABs and CRANs with a sensitivity of 98.13 % and a specificity of 100 %.Conclusion. The Pan-PCR and OXA-PCR assays are promising alternative methods for rapid molecular typing of CRABs and CRANs in a routine laboratory setting.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Acinetobacter/efeitos dos fármacos , Acinetobacter/genética , Carbapenêmicos/farmacologia , Reação em Cadeia da Polimerase/métodos , Acinetobacter/classificação , Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/classificação , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Humanos , Taiwan/epidemiologia
7.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209998

RESUMO

Acne vulgaris, which is mostly associated with the colonization of Cutibacterium acnes (C. acnes), is a common skin inflammatory disease in teenagers. However, over the past few years, the disease has extended beyond childhood to chronically infect approximately 40% of adults. While antibiotics have been used for several decades to treat acne lesions, antibiotic resistance is a growing crisis; thus, finding a new therapeutic target is urgently needed. Studies have shown that phage therapy may be one alternative for treating multi-drug-resistant bacterial infections. In the present study, we successfully isolated a C. acnes phage named TCUCAP1 from the skin of healthy volunteers. Morphological analysis revealed that TCUCAP1 belongs to the family Siphoviridae with an icosahedral head and a non-contractile tail. Genome analysis found that TCUCAP1 is composed of 29,547 bp with a G+C content of 53.83% and 56 predicted open reading frames (ORFs). The ORFs were associated with phage structure, packing, host lysis, DNA metabolism, and additional functions. Phage treatments applied to mice with multi-drug-resistant (MDR) C.-acnes-induced skin inflammation resulted in a significant decrease in inflammatory lesions. In addition, our attempt to formulate the phage into hydroxyethyl cellulose (HEC) cream may provide new antibacterial preparations for human infections. Our results demonstrate that TCUCAP1 displays several features that make it an ideal candidate for the control of C. acnes infections.


Assuntos
Acne Vulgar/terapia , Terapia por Fagos/métodos , Propionibacterium acnes/virologia , Siphoviridae/classificação , Sequenciamento Completo do Genoma/métodos , Acne Vulgar/microbiologia , Animais , Composição de Bases , Celulose/química , Modelos Animais de Doenças , Composição de Medicamentos , Farmacorresistência Bacteriana Múltipla , Tamanho do Genoma , Genoma Viral , Voluntários Saudáveis , Humanos , Injeções Intradérmicas , Camundongos , Fases de Leitura Aberta , Filogenia , Propionibacterium acnes/fisiologia , Siphoviridae/genética , Siphoviridae/isolamento & purificação , Pele/virologia
8.
BMC Infect Dis ; 21(1): 526, 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34090384

RESUMO

BACKGROUND: Klebsiella spp. are important pathogens associated with bacteremia among admitted children and is among the leading cause of death in children < 5 years in postmortem studies, supporting a larger role than previously considered in childhood mortality. Herein, we compared the antimicrobial susceptibility, mechanisms of resistance, and the virulence profile of Klebsiella spp. from admitted and postmortem children. METHODS: Antimicrobial susceptibility and virulence factors of Klebsiella spp. recovered from blood samples collected upon admission to the hospital (n = 88) and postmortem blood (n = 23) from children < 5 years were assessed by disk diffusion and multiplex PCR. RESULTS: Klebsiella isolates from postmortem blood were likely to be ceftriaxone resistant (69.6%, 16/23 vs. 48.9%, 43/88, p = 0.045) or extended-spectrum ß-lactamase (ESBL) producers (60.9%, 14/23 vs. 25%, 22/88, p = 0.001) compared to those from admitted children. blaCTX-M-15 was the most frequent ESBL gene: 65.3%, 9/14 in postmortem isolates and 22.7% (5/22) from admitted children. We found higher frequency of genes associated with hypermucoviscosity phenotype and invasin in postmortem isolates than those from admitted children: rmpA (30.4%; 7/23 vs. 9.1%, 8/88, p = 0.011), wzi-K1 (34.7%; 8/23 vs. 8%; 7/88, p = 0.002) and traT (60.8%; 14/23 vs. 10.2%; 9/88, p < 0.0001), respectively. Additionally, serine protease auto-transporters of Enterobacteriaceae were detected from 1.8% (pic) to 12.6% (pet) among all isolates. Klebsiella case fatality rate was 30.7% (23/75). CONCLUSION: Multidrug resistant Klebsiella spp. harboring genes associated with hypermucoviscosity phenotype has emerged in Mozambique causing invasive fatal disease in children; highlighting the urgent need for prompt diagnosis, appropriate treatment and effective preventive measures for infection control.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Enterobacteriaceae/mortalidade , Klebsiella/efeitos dos fármacos , Klebsiella/genética , Fatores de Virulência/genética , Autopsia , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Pré-Escolar , Infecções por Enterobacteriaceae/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Klebsiella/isolamento & purificação , Masculino , Testes de Sensibilidade Microbiana , Moçambique/epidemiologia , beta-Lactamases/genética
10.
Biomolecules ; 11(5)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067685

RESUMO

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum ß-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25-50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Antivirais/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Antivirais/química , Candida albicans/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dimerização , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , SARS-CoV-2/efeitos dos fármacos
11.
Int J Nanomedicine ; 16: 3755-3773, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34103914

RESUMO

Purpose: Acinetobacter baumannii antibiotic resistant infections in high-risk patients are a great challenge for researchers and clinicians worldwide. In an effort to achieve potent bactericidal outcomes, a novel chitosan-mastoparan nanoconstruct (Mast-Cs NC) was designed and assessed for its therapeutic potential through in silico, in vitro and in vivo experimentation against clinical multidrug-resistant (MDR) A. baumannii. Methods: Optimized 3D structures of mastoparan and chitosan were coupled computationally through an ionic cross-linker to generate a circular ring of chitosan encasing mastoparan. The complex was assessed for interactions and stability through molecular dynamic simulation (MDS). Binding pocket analysis was used to assess the protease-peptide interface. Mast-Cs NC were prepared by the ionic gelation method. Mast-Cs NC were evaluated in vitro and in vivo for their therapeutic efficacy against drug-resistant clinical A. baumannii. Results: MDS for 100 ns showed stable bonds between chitosan and mastoparan; the first at chitosan oxygen atom-46 and mastoparan isoleucine carbon atom with a distance of 2.77 Å, and the second between oxygen atom-23 and mastoparan lysine nitrogen atom with a distance of 2.80 Å, and binding energies of -3.6 and -7.4 kcal/mol, respectively. Mast-Cs complexes approximately 156 nm in size, with +54.9 mV zeta potential and 22.63% loading capacity, offered >90% encapsulation efficiency and were found to be geometrically incompatible with binding pockets of various proteases. The MIC90 of Mast-Cs NC was significantly lower than that of chitosan (4 vs 512 µg/mL, respectively, p<0.05), with noticeable bacterial damage upon morphological analysis. In a BALB/c mouse sepsis model, a significant reduction in bacterial colony count in the Mast-Cs treated group was observed compared with chitosan and mastoparan alone (p<0.005). Mast-Cs maintained good biocompatibility and cytocompatibility. Conclusion: Novel mastoparan-loaded chitosan nanoconstructs signify a successful strategy for achieving a synergistic bactericidal effect and higher therapeutic efficacy against MDR clinical A. baumannii isolates. The Mast-Cs nano-drug delivery system could work as an alternative promising treatment option against MDR A. baumannii.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Quitosana/química , Simulação por Computador , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Nanopartículas/química , Venenos de Vespas/farmacologia , Acinetobacter baumannii/crescimento & desenvolvimento , Acinetobacter baumannii/isolamento & purificação , Adolescente , Adulto , Animais , Antibacterianos/farmacologia , Criança , Pré-Escolar , Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Simulação de Dinâmica Molecular , Nanopartículas/ultraestrutura , Peptídeo Hidrolases/metabolismo , Peptídeos/química , Peptídeos/farmacologia , Adulto Jovem
12.
BMC Infect Dis ; 21(1): 547, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34107903

RESUMO

BACKGROUND: The rise of Multidrug-resistant organisms (MDROs) poses a considerable burden on the healthcare systems, particularly in low-middle income countries like Pakistan. There is a scarcity of data on the carriage of MDRO particularly in the pediatrics population therefore, we aimed to determine MDRO carriage in pediatric patients at the time of admission to a tertiary care hospital in Karachi, Pakistan, and to identify the risk factors associated with it. METHODS: A cross-sectional study conducted at the pediatric department of Aga Khan University Hospital (AKUH) from May to September 2019 on 347 children aged 1-18 years. For identification of MDRO (i.e., Extended Spectrum Beta-Lactamase (ESBL) producers, Carbapenem Resistant Enterobacteriaceae (CRE), Vancomycin Resistant Enterococci (VRE), Methicillin Resistant Staphylococcus aureus (MRSA), Multidrug-resistant (MDR) Acinetobacter species and MDR Pseudomonas aeruginosa), nasal swabs and rectal swabs or stool samples were cultured on specific media within 72 h of hospitalization. Data was collected on a predesigned structured questionnaire on demographics, prior use of antibiotics for > 48 h in the last 6 months, history of vaccination in last 6 months, exposure to health care facility regardless of the time of exposure, ICU stay for > 72 h, and about the prior use of medical devices (urinary catheter, central venous lines etc.) in last 1 year. Statistical analysis was performed by Standard statistical software. RESULTS: Out of 347 participants, 237 (68.3%) were found to be MDRO carriers. Forty nine nasal swabs from 346 children (14.2%) showed growth of MRSA. The majority of the stool/rectal swabs (n = 222 of 322; 69%) collected were positive for MDRO. The most isolated species were ESBL Escherichia coli 174/222 (78.3%) followed by ESBL Enterobacter species 37/222 (16.7%) and ESBL Klebsiella pneumoniae 35/222 (15.8%). On univariate analysis, none of the risk factors showed statistically significant association with MDRO carriage. CONCLUSION: Overall, a high prevalence of MDRO carriage was identified among admitted pediatric patients. Implementation of systematic screening may help to identify true burden of MDROs carriage in the health care settings.


Assuntos
Farmacorresistência Bacteriana Múltipla , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Hospitalização , Humanos , Lactente , Masculino , Paquistão/epidemiologia , Admissão do Paciente , Pediatria , Prevalência , Fatores de Risco , Centros de Atenção Terciária
13.
Int J Mol Sci ; 22(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073939

RESUMO

An amphipathic α-helical peptide, Hp1404, was isolated from the venomous gland of the scorpion Heterometrus petersii. Hp1404 exhibits antimicrobial activity against methicillin-resistant Staphylococcus aureus but is cytotoxic. In this study, we designed antimicrobial peptides by substituting amino acids at the 14 C-terminal residues of Hp1404 to reduce toxicity and improve antibacterial activity. The analog peptides, which had an amphipathic α-helical structure, were active against gram-positive and gram-negative bacteria, particularly multidrug-resistant Acinetobacter baumannii, and showed lower cytotoxicity than Hp1404. N-phenyl-1-naphthylamine uptake and DisC3-5 assays demonstrated that the peptides kill bacteria by effectively permeating the outer and cytoplasmic membranes. Additionally, the analog peptides inhibited biofilm formation largely than Hp1404 at low concentrations. These results suggest that the analog peptides of Hp1404 can be used as therapeutic agents against A. baumannii infection.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escorpiões/química , 1-Naftilamina/análogos & derivados , 1-Naftilamina/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/efeitos adversos , Peptídeos Catiônicos Antimicrobianos/química , Benzotiazóis/metabolismo , Biofilmes/efeitos dos fármacos , Carbocianinas/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Escherichia coli/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Conformação Proteica em alfa-Hélice , Pseudomonas aeruginosa/efeitos dos fármacos , Salmonella/efeitos dos fármacos
14.
Medicine (Baltimore) ; 100(23): e25907, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34114986

RESUMO

ABSTRACT: If wounds are infected with bacteria resistant to an empirical antibiotic regimen, effective wound treatment will be delayed. This can delay wound healing and lengthen hospital stays, increasing the costs to patients. Long-term antibiotic use can also result in minor and major complications, such as diarrhea, antibiotic resistance, or life-threatening leukopenia. Multidrug-resistant (MDR) bacteria make wound treatment even more difficult. Traditionally, surgeons thought that adequate infection control should be established before soft tissue coverage. However, wounds infected by MDR do not heal well with this traditional method and there are no optimal treatment guidelines for MDR bacteria-contaminated wounds.We reviewed 203 patients who underwent vascularized flap surgery from 2012 to 2019 to cover wounds. Class IV and I wounds were compared according to the Centers for Disease Control and Prevention classification. Class IV was further classified as antibiotic-resistant (ARB) and antibiotic-sensitive (ASB) bacteria. Wound size, mode, location, pathogens, healing time, and basic demographics were evaluated. Data were compared using Cramer's V and one-way ANOVA or independent t tests.The average healing time was longer in the ARB (19.7 [range 7-44] days) and ASB (17.9 [range 2-36] days) groups than in the Clean group (16.5 [range 7-28] days). Healing time differed in the 3 groups (P = .036). It was longer in the class IV group than in the class I group (P = .01). However, it was not statistically different between the ARB and ASB groups (P = .164).In our study the difference in healing time was small when vascularized tissue transfer was done in ARB-infected wound compared with ASB-infected and clean wound. It is necessary to perform surgery using vascularized tissue for the infected wound of antibiotic-resistant bacteria.


Assuntos
Antibacterianos , Bactérias , Alotransplante de Tecidos Compostos Vascularizados , Infecção dos Ferimentos , Antibacterianos/administração & dosagem , Antibacterianos/efeitos adversos , Antibacterianos/classificação , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Avaliação de Processos e Resultados em Cuidados de Saúde , República da Coreia/epidemiologia , Retalhos Cirúrgicos , Alotransplante de Tecidos Compostos Vascularizados/efeitos adversos , Alotransplante de Tecidos Compostos Vascularizados/métodos , Cicatrização , Infecção dos Ferimentos/epidemiologia , Infecção dos Ferimentos/microbiologia , Infecção dos Ferimentos/fisiopatologia , Infecção dos Ferimentos/terapia
15.
Int J Mol Sci ; 22(10)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069596

RESUMO

Acinetobacter baumannii is a serious nosocomial pathogen with multiple drug resistance (MDR), the control of which has become challenging due to the currently used antibiotics. Our main objective in this study is to determine the antibacterial and antibiofilm activities of the antimicrobial peptide, Octominin, against MDR A. baumannii and derive its possible modes of actions. Octominin showed significant bactericidal effects at a low minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of 5 and 10 µg/mL, respectively. Time-kill kinetic analysis and bacterial viability tests revealed that Octominin showed a concentration-dependent antibacterial activity. Field-emission scanning electron microscopy (FE-SEM) analysis revealed that Octominin treatment altered the morphology and membrane structure of A. baumannii. Propidium iodide (PI) and reactive oxygen species (ROS) generation assays showed that Octominin increased the membrane permeability and ROS generation in A. baumannii, thereby causing bacterial cell death. Further, a lipopolysaccharides (LPS) binding assay showed an Octominin concentration-dependent LPS neutralization ability. Biofilm formation inhibition and eradication assays further revealed that Octominin inhibited biofilm formation and showed a high biofilm eradication activity against A. baumannii. Furthermore, up to a concentration of 100 µg/mL, Octominin caused no hemolysis and cell viability changes in mammalian cells. An in vivo study in zebrafish showed that the Octominin-treated group had a significantly higher relative percentage survival (54.1%) than the untreated group (16.6%). Additionally, a reduced bacterial load and fewer alterations in histological analysis confirmed the successful control of A. baumannii by Octominin in vivo. Collectively, these data suggest that Octominin exhibits significant antibacterial and antibiofilm activities against the multidrug-resistant A. baumannii, and this AMP can be developed further as a potent AMP for the control of antibiotic resistance.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/metabolismo , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Biofilmes/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Sinergismo Farmacológico , Cinética , Viabilidade Microbiana/efeitos dos fármacos , Modelos Animais , Fragmentos de Peptídeos/metabolismo , Peixe-Zebra
16.
BMC Infect Dis ; 21(1): 611, 2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34174823

RESUMO

BACKGROUND: Carbapenem-resistant Enterobacter cloacae complex (CREC) is a new emerging threat to global public health. The objective of the study was to investigate the clinical characteristics and molecular epidemiology of CREC infections in the medical center of northeast China. METHODS: Twenty-nine patients were infected/colonized with CREC during a ten-year period (2010-2019) by WHONET analysis. Antibiotic susceptibilities were tested with VITEK 2 and micro broth dilution method (for polymyxin B and tigecycline). Carbapenemase encoding genes, ß-lactamase genes, and seven housekeeping genes for MLST were amplified and sequenced for 18 cryopreserved CREC isolates. Maximum likelihood phylogenetic tree was built with the concentrated sequences to show the relatedness between the 18 isolates. RESULTS: There was a rapid increase in CREC detection rate during the ten-year period, reaching 8.11% in 2018 and 6.48% in 2019. The resistance rate of CREC isolates to imipenem and meropenem were 100.0 and 77.8%, however, they showed high sensitivity to tigecycline, polymyxin B and amikacin. The 30-day crude mortality of CREC infection was 17.4%, indicating that it may be a low-virulence bacterium. Furthermore, molecular epidemiology revealed that ST93 was the predominant sequence type followed by ST171 and ST145, with NDM-1 and NDM-5 as the main carbapenemase-encoding genes. Moreover, E. hormaechei subsp. steigerwaltii and E. hormaechei subsp. oharae were the main species, which showed different resistance patterns. CONCLUSION: Rising detection rate of CREC was observed in a tertiary hospital, which showed heterogeneity in drug resistance patterns, resistance genes, and MLST types. Effective infection prevention and control measures should be taken to reduce the spread of CREC.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Carbapenêmicos/uso terapêutico , Farmacorresistência Bacteriana Múltipla , Enterobacter cloacae , Infecções por Enterobacteriaceae/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , China/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/genética , Enterobacter cloacae/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Feminino , História do Século XXI , Humanos , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Filogenia , Centros de Atenção Terciária/estatística & dados numéricos , Adulto Jovem , beta-Lactamases/genética
17.
Braz J Biol ; 82: e239991, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34190801

RESUMO

High resistance to antimicrobials is associated with biofilm formation responsible for infectious microbes to withstand severe conditions. Therefore, new alternatives are necessary as biofilm inhibitors to control infections. In this study, the antimicrobial and antibiofilm activities of Fagonia indica extracts were evaluated against MDR clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica has antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against multidrug resistant (MDR) clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica had antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against MDR isolates. The maximum inhibitory effects of Fagonia indica chloroform extract on biofilm formation was observed on Staphylococcus aureus (71.84%) followed by Klebsiella pneumoniae (70.83%) after 48 hrs showing that inhibition is also time dependent. Our results about bacterial cell protein leakage indicated that MDR isolates treated with chloroform extract of Fagonia indica showed maximum protein leakage of K. pneumoniae (59.14 µg mL-1) followed by S. aureus (56.7 µg mL-1). Cell attachment assays indicated that chloroform extract resulted in a 43.5-53.5% inhibition of cell adherence to a polystyrene surface. Our results revealed that extracts of Fagonia indica significantly inhibited biofilm formation among MDR clinical isolates, therefore, could be applied as antimicrobial agents and cost effective biofilm inhibitor against these MDR isolates.


Assuntos
Extratos Vegetais , Staphylococcus aureus , Bactérias , Biofilmes , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia
18.
Rev Peru Med Exp Salud Publica ; 38(1): 130-135, 2021.
Artigo em Espanhol, Inglês | MEDLINE | ID: mdl-34190905

RESUMO

The present report is the original description of bla TEM-176. The mechanisms of resistance to antimicrobial agents were determined in an enterotoxigenic Escherichia coli, determining the susceptibility to 22 antimicrobials classified in 15 different groups by agar diffusion and establishing the phylogenetic group, mechanisms of resistance and presence of Class 1 and 2 integrons. Integrons and ß-lactam resistance genes were sequenced. The isolate, belonging to phylogenetic group A, showed the presence of resistance or diminished susceptibility to a ampicillin, amoxicillin plus clavulanic acid, nalidíxic acid, ciprofloxacin, streptomycin, kanamycin, tetracycline, trimethoprim, sulfisoxazole, cotrimoxazole, azithromycin and nitrofurantoin, carrying bla TEM, aadA1/2, aphA1, sul3, tet(A) and a Class 2 integron containing a dfrA1 gene. Quinolone resistance was related to the substitution Ser83Ala. The TEM sequencing showed the presence of the new substitution Ala222Val, which led to the description of the new ß-lactamase bla TEM-176.


Assuntos
Escherichia coli , beta-Lactamases , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Integrons/genética , Testes de Sensibilidade Microbiana , Filogenia , beta-Lactamases/genética
19.
Int J Mol Sci ; 22(9)2021 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-34065133

RESUMO

Low-molecular-weight organic ammonium salts exert excellent antimicrobial effects by interacting lethally with bacterial membranes. Unfortunately, short-term functionality and high toxicity limit their clinical application. On the contrary, the equivalent macromolecular ammonium salts, derived from the polymerization of monomeric ammonium salts, have demonstrated improved antibacterial potency, a lower tendency to develop resistance, higher stability, long-term activity, and reduced toxicity. A water-soluble non-quaternary copolymeric ammonium salt (P7) was herein synthetized by copolymerizing 2-methoxy-6-(4-vinylbenzyloxy)-benzylammonium hydrochloride monomer with N, N-di-methyl-acrylamide. The antibacterial activity of P7 was assessed against several multidrug-resistant (MDR) clinical isolates of both Gram-positive and Gram-negative species. Except for colistin-resistant Pseudomonas aeruginosa, most isolates were susceptible to P7, also including some Gram-negative bacteria with a modified charge in the external membrane. P7 showed remarkable antibacterial activity against isolates of Enterococcus, Staphylococcus, Acinetobacter, and Pseudomonas, and on different strains of Escherichia coli and Stenotrophomonas maltophylia, regardless of their antibiotic resistance. The lowest minimal inhibitory concentrations (MICs) observed were 0.6-1.2 µM and the minimal bactericidal concentrations (MBC) were frequently overlapping with the MICs. In 24-h time-kill and turbidimetric studies, P7 displayed a rapid non-lytic bactericidal activity. P7 could therefore represent a novel and potent tool capable of counteracting infections sustained by several bacteria that are resistant to the presently available antibiotics.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Compostos de Benzilamônio/química , Compostos de Benzilamônio/farmacologia , Polímeros , Antibacterianos/síntese química , Bactérias/efeitos dos fármacos , Compostos de Benzilamônio/síntese química , Técnicas de Química Sintética , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Polimerização , Polímeros/química , Análise Espectral
20.
Int J Food Microbiol ; 351: 109268, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34098467

RESUMO

The increase in multidrug-resistant Salmonella enterica and its spread from food to humans are considered a serious public health concern worldwide. Little is currently known about the prevalence of extended-spectrum ß-lactamase (ESBL)-producing S. enterica in fish in Africa. Therefore, this study aimed to investigate the existence of ESBL-producing S. enterica in retail fish in Egypt. In total, 200 fish samples were collected randomly from various retail fish markets in Egypt. S. enterica were detected in 19 (9.5%; 95% CI: 5.8-14.4) of the fish samples analyzed. Of the 19 non-repetitive S. enterica isolates, 18 were serologically categorized into eight S. enterica serovars and a non-typable serovar. All 19 S. enterica isolates (100%) showed multidrug-resistant phenotypes to at least three classes of antimicrobials, and 11 (57.9%) exhibited an ESBL-resistant phenotype and harbored at least one ESBL-encoding gene. The ESBL-producing S. enterica serovars were as follows: Kentucky (3 isolates; 15.8%), Enteritidis (2 isolates; 10.5%), Typhimurium (2 isolates; 10.5%), and 1 isolate (5.3%) each of Infantis, Virchow, Paratyphi B, and Senftenberg. The identified ß-lactamase-encoding genes included ESBL-encoding genes blaCTX-M-3, blaCTX-M-14, blaCTX-M-15, blaSHV-1, blaSHV-2 and blaSHV-12; the AmpC ß-lactamase-encoding gene blaCMY-2; and the narrow-spectrum ß-lactamase-encoding genes blaTEM-1 and blaOXA-1. All S. enterica isolates were negative for carbapenemase-encoding genes. Molecular analysis of plasmid transferability and replicon typing revealed that most plasmids (with ß-lactamase-encoding genes) were transferrable, and the most common incompatibility groups were IncI1, IncA/C, IncHI1, and IncN. To the best of our knowledge, this is the first report for molecular characterization of ESBL-producing S. enterica in fish in Egypt. The occurrence of ESBL-producing S. enterica in retail fish constitutes a potential public health threat with the possibility of transmission of these strains with resistance genes to humans. Such transmission would exacerbate the resistance to an important class of antibiotics commonly used in hospitals to treat typhoid and non-typhoidal Salmonella infections.


Assuntos
Peixes/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/metabolismo , beta-Lactamases/metabolismo , Animais , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Egito/epidemiologia , Humanos , Plasmídeos/genética , Prevalência , Saúde Pública , Salmonelose Animal/epidemiologia , Salmonella enterica/efeitos dos fármacos , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , beta-Lactamases/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...