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1.
J Sci Food Agric ; 100(2): 874-884, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31680264

RESUMO

BACKGROUND: The low cost of aminoglycoside (AMG) antibiotics facilitates their excessive use in animal husbandry and the agriculture sector. This scenario has led to the occurrence of residues in the food chain. After several years of AMG use in antibacterial therapy, resistance to streptomycin has begun to appear. Most of the detection methods developed for AMG antibiotics lacks specificity. A broad target specific nanoprobe would be ideal for detecting the entire class of AMGs. A rapid and sensitive method for the detection of AMGs is urgently needed. RESULTS: Gallic acid-coated silver nanoparticles (AgNPs) were demonstrated as a nanoprobe for the colorimetric detection of AMGs (yellow to orange / red). A linear dynamic range of 50-650 pmol L-1 was achieved readily by ratiometric spectrophotometry (A560 /A400 ) with a limit of detection (LOD) as low as 36 pmol L-1 . The amine-groups of the AMGs function as molecular linkers, so that electrostatic coupling interactions between neighboring particles drive the formation of AgNP aggregates. The assay can also be applied for the determination of streptomycin residues in serum and milk samples. CONCLUSION: This study revealed the potential of an AgNP probe for the rapid and cost-effective detection of low-molecular-weight target analytes, such as the AMGs. A ligand-induced aggregation of AgNPs coated with gallic acid was reported to be a rapid and sensitive assay for AMGs. Analysis of streptomycin was demonstrated with excellent picomolar-level sensitivity. Thus, the validated method can find practical applications in the ultrasensitive detection of AMGs in complex and diagnostic settings. © 2019 Society of Chemical Industry.


Assuntos
Antibacterianos/análise , Colorimetria/métodos , Resíduos de Drogas/análise , Leite/química , Soro/química , Estreptomicina/análise , Água/química , Animais , Antibacterianos/farmacologia , Bovinos , Colorimetria/instrumentação , Limite de Detecção , Nanopartículas Metálicas/química , Prata/química
2.
Food Chem ; 308: 125682, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31655479

RESUMO

In this work, a multifunctional food packaging composite coating with transparent, biodegradable, antifogging and antibacterial properties was designed and fabricated by quaternary ammonium salt modified chitosan (HACC) and poly (vinyl alcohol) (PVA) via a facile and environment-friendly solution casting method. A simple quaternization modification enabled the coating simultaneously to achieve excellent antifogging and antibacterial functions. The excellent antifogging property of the HACC/PVA composite coating was attributed to the strong water absorbency of quaternary ammonium chitosan and PVA. A nearly 98% transmittance ratio of coated glasses was achieved during antifogging test. In addition, the inhibition rate of the HACC/PVA composite coating kill against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Botrytis cinerea were up to ~99%. The antibacterial effect was demonstrated by each group of strawberries after storage for 1, 3, 5 days. The multifunctional coating has broad prospects in the application of fruit and vegetable packaging.


Assuntos
Compostos de Amônio/química , Antibacterianos/farmacologia , Quitosana/farmacologia , Embalagem de Alimentos , Quitosana/química , Escherichia coli/efeitos dos fármacos , Compostos de Amônio Quaternário , Staphylococcus aureus/efeitos dos fármacos
3.
Huan Jing Ke Xue ; 41(1): 313-320, 2020 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854932

RESUMO

Wastewater treatment plants hold a vast pool of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). The aim of this study is to analyze the ARB and ARGs in a pharmaceutical and chemical wastewater treatment plant using a metagenomic technique. The results of taxonomic annotation revealed that bacteria were the predominant domain. The most abundant phyla and genus was Proteobacteria and Hyphomicrobium, respectively. A total of 74 categories of ARGs were predicted using CARD with the most dominant types being sav 1866, dfrE, and mfd. Furthermore, a network analysis was conducted to investigate the co-occurrence patterns between ARGs and microbial taxa. ARGs were found to be highly connected to microbial taxa at the genus level. With respect to the antibiotic resistance mechanisms, antibiotic-specific efflux pumps appeared to be the most common mechanisms. Among these, resistance-nodulation-cell division (RND) was the major type. The most important functional pathway of this microbial community was metabolic correlation. Interestingly, there were many genes related to human diseases, among which bacterial infectious diseases were the main ones. On the one hand, these data further confirmed that pharmaceutical and chemical wastewater treatment plants are rich in ARB and ARGs. The accumulation of ARGs increases the potential environmental risks, and hence it is necessary to strengthen the active monitoring of ARB and ARGs in pharmaceutical and chemical wastewater treatment plants. On the other hand, research on ARB and ARGs offers important information for the selection of deep processing technology to effectively remove ARB and ARGs.


Assuntos
Bactérias/classificação , Farmacorresistência Bacteriana , Genes Bacterianos , Águas Residuárias , Purificação da Água , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Humanos , Metagenoma , Preparações Farmacêuticas
4.
J Colloid Interface Sci ; 558: 47-54, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31580954

RESUMO

The unique antibacterial characteristics of Ag nanomaterials offer a wide potential range of applications, but achieving rapid and durable antibacterial efficacy is challenging. This is because the speed and durability of the antibacterial function make conflicting demands on the structural design: the former requires the direct exposure of Ag to the surrounding environment, whereas the durability requires Ag to be protected from the environment. To overcome this incompatibility, we synthesize sandwich-structured polydopamine shells decorated both internally and externally with Ag nanoparticles, which exhibit prompt and lasting bioactivity in applications. These shells are biocompatible and can be used in vivo to counter bacterial infection caused by methicillin-resistant Staphylococcus aureus superbugs and to inhibit biofilm formation. This work represents a new paradigm for the design of composite materials with enhanced antibacterial properties.


Assuntos
Antibacterianos/química , Materiais Biocompatíveis/química , Indóis/química , Nanopartículas Metálicas/química , Polímeros/química , Prata/química , Animais , Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Escherichia coli/efeitos dos fármacos , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Ratos , Ratos Sprague-Dawley
5.
J Sci Food Agric ; 100(1): 335-342, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31584691

RESUMO

BACKGROUND: Antibacterial activity of honey is not only crucial characteristic in selection of honey for medical usage but also an important honey quality marker. The aim of the study was to characterise the antibacterial potential of 29 honey samples representing the main types of multi-floral blossom and honeydew honeys produced in Switzerland. Antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa was expressed as a minimum inhibitory and bactericidal concentrations (MIC and MBC). Furthermore, the content of bee-derived glucose oxidase (GOX) and its enzymatic product, H2 O2 , were also evaluated. RESULTS: All honey samples successfully met basic defined criteria (moisture and hydroxymethylfurfural (HMF)) tested in this study. Honeydew honeys were the most effective honey samples and generated the highest levels of H2 O2 . A strong significant correlation was found between the overall antibacterial activity and the level of H2 O2 among all honey samples. Interestingly, the content of GOX in honey samples did not correlate with their antibacterial activity as well as H2 O2 production capacity. A weak antibacterial activity was determined in five floral honeys, most likely due to increased enzymatic activity of pollen-derived catalase. CONCLUSION: This study showed that antibacterial effect of Swiss honey samples is associated mainly with H2 O2 . © 2019 Society of Chemical Industry.


Assuntos
Antibacterianos/análise , Mel/análise , Animais , Antibacterianos/farmacologia , Abelhas , Catalase/análise , Glucose Oxidase/análise , Mel/classificação , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Suíça
6.
Gut ; 69(1): 83-91, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31611298

RESUMO

OBJECTIVE: The underlying microbial basis, predictors of therapeutic outcome and active constituent(s) of faecal microbiota transplantation (FMT) mediating benefit remain unknown. An international panel of experts presented key elements that will shape forthcoming FMT research and practice. DESIGN: Systematic search was performed, FMT literature was critically appraised and a 1-day round-table discussion was conducted to derive expert consensus on key issues in FMT research. RESULTS: 16 experts convened and discussed five questions regarding (1) the role of donor and recipient microbial (bacteria, viruses, fungi) parameters in FMT; (2) methods to assess microbiota alterations; (3) concept of keystone species and microbial predictors of FMT, (4) influence of recipient profile and antibiotics pretreatment on FMT engraftment and maintenance and (5) new developments in FMT formulations and delivery. The panel considered that variable outcomes of FMT relate to compositional and functional differences in recipient's microbiota, and likely donor-associated and recipient-associated physiological and genetic factors. Taxonomic composition of donor intestinal microbiota may influence the efficacy of FMT in recurrent Clostridioides difficile infections and UC. FMT not only alters bacteria composition but also establishes trans-kingdom equilibrium between gut fungi, viruses and bacteria to promote the recovery of microbial homeostasis. FMT is not a one size fits all and studies are required to identify microbial components that have specific effects in patients with different diseases. CONCLUSION: FMT requires optimisation before their therapeutic promise can be evaluated for different diseases. This summary will guide future directions and priorities in advancement of the science and practice of FMT.


Assuntos
Transplante de Microbiota Fecal/métodos , Antibacterianos/farmacologia , Clostridium difficile , Endoscopia Gastrointestinal , Enterocolite Pseudomembranosa/terapia , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/fisiologia , Humanos , Doenças Inflamatórias Intestinais/terapia , Prognóstico , Recidiva , Doadores de Tecidos , Resultado do Tratamento
7.
Equine Vet J ; 52(1): 112-119, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31033041

RESUMO

BACKGROUND: Horses are one of the potential reservoirs of antimicrobial resistance (AMR) determinants that could be transferred to human subjects. OBJECTIVE: To describe the AMR patterns of major bacteria isolated from diseased horses in France. STUDY DESIGN: Retrospective observational study. METHODS: Data collected between 2012 and 2016 by RESAPATH, the French national surveillance network for AMR, were analysed. Only antimicrobials relevant in veterinary and human medicine for the isolated bacteria were considered. Mono- and multidrug resistance were calculated. The resistance proportions of major equine diseases were assessed and compared. Where data permitted, resistance trends were investigated using nonlinear analysis (generalised additive models). RESULTS: A total of 12,695 antibiograms were analysed. The five most frequently isolated bacteria were Streptococcus spp., Escherichia coli, Pseudomonas spp., Staphylococcus aureus, Pantoea spp. and Klebsiella spp. The highest proportions of resistance to gentamicin were found for S. aureus (22.1%) and Pseudomonas spp. (26.9%). Klebsiella spp. and E. coli had the highest proportions of resistance to trimethoprim-sulfamethoxazole (15.5 and 26.2%, respectively). Proportions of resistance to tetracycline were among the highest for all the bacteria considered. Resistance to third-generation cephalosporins was below 10% for all Enterobacteriaceae. The highest proportions of multidrug resistance (22.5%) were found among S. aureus isolates, which is worrying given their zoonotic potential. From 2012 to 2016, resistance proportions decreased in Pseudomonas spp. isolates, but remained the same for S. aureus. For Streptococcus spp. and E. coli, resistance proportions to trimethoprim-sulfamethoxazole increased. MAIN LIMITATIONS: Since antibiograms are not systematic analyses, any selection bias could impact the results. CONCLUSIONS: Such studies are essential to estimate the magnitude of the potential threat of AMR to public health, to design efficient control strategies and to measure their effectiveness. These findings may also guide the initial empirical treatment of horse diseases.


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/veterinária , Farmacorresistência Bacteriana Múltipla , Doenças dos Cavalos/microbiologia , Animais , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/microbiologia , França/epidemiologia , Doenças dos Cavalos/epidemiologia , Cavalos , Saúde Pública , Estudos Retrospectivos
8.
Chemosphere ; 238: 124570, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31437629

RESUMO

Inhibition of anammox activities was tested with two ranges of chloramphenicol (CAP) concentration (5, 10, 20, 50, and 100 mg L-1) and (100, 500, and 1000 µg L-1). In a short-term study, strong inhibition of activity was dependent of CAP concentration in both attached-growth (SBR-A) and suspended-growth (SBR-S) systems. The activities of attached-growth cultures at all CAP concentrations were reversible after 1 day, while activities for suspended-growth cultures were only gradually reversible dependent on the CAP concentrations. In long-term studies with daily additions of 6 mg L-1 CAP, the anammox activity on day 41 in SBR-A had decreased to 18% baseline (SAA reduced from 0.528 to 0.096 mg N mg-1 VSS d-1). More rapid reduction of anammox activity was observed in SBR-S, down to 17% baseline after only 27 days (SAA decreased from 0.576 to 0.096 mg N mg-1 VSS d-1). Inhibition was irreversible in both SBR-S and SBR-A after the long-term study. With lower CAP additions (100-1000 µg L-1), the activities in both reactors were stable during daily CAP addition for two weeks. Attached-growth cultures tended to be more tolerant of CAP addition than suspended-growth cultures. Both un-competitive and non-competitive models could be used to compare anammox activities with the higher CAP concentrations. The SAAmax [fx] (the maximum specific anammox activity) and hKi (the inhibition constant) of SBR-A were 0.48 mg N mg-1 VSS d-1 and 98.3 mg L-1, respectively. The SAAmax[fx] and Ki of SBR-S were 1.25 mg N mg-1 VSS d-1and 71.1 mg L-1, respectively.


Assuntos
Compostos de Amônio/metabolismo , Antibacterianos/farmacologia , Bactérias Anaeróbias/crescimento & desenvolvimento , Bactérias Anaeróbias/metabolismo , Reatores Biológicos/microbiologia , Cloranfenicol/farmacologia , Anaerobiose , Nitrogênio , Oxirredução
9.
Food Microbiol ; 85: 103286, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31500709

RESUMO

Hispanic style soft non-fermented cheeses, such as queso fresco (QF) have been linked to outbreaks and recalls. Salmonella is one of the main causes of these incidents. Due to lack of ripening or post-processing antimicrobial treatments, incorporating GRAS antimicrobials to production process may be a suitable approach to minimize microbial risk in QF. The aim of this study was to evaluate the efficiency of nisin (N), caprylic acid (CA) and trans-cinnamaldehyde (CN) as single or combined treatments to reduce Salmonella populations in QF during storage. Batches of QF were inoculated after curding with approx. 4 Log CFU/g of 5-strain cocktails of Salmonella and stored at 8 °C for 20 days. The final Salmonella counts in control samples ranged from 6.96 to 7.14 Log CFU/g. Application of CN at 0.6 g/kg inhibited Salmonella growth during storage, resulting in at least 3 Log CFU/g difference with the untreated controls (p < 0.05). Addition of N (0.5 g/kg) and CA (0.4 g/kg) with CN (0.3 and 0.6 g/kg) further enhanced the antimicrobial activity resulting in complete suppression of growth and even caused a 1 Log CFU/g reduction by the end of the experimental period compared to initial counts. Samples treated with the combined treatment (N, CA, CN) were evaluated in a consumer panel (n = 112). Participants preferred the control and commercial QF to the treated samples. However, treated samples with 0.3 g/kg CN were still within the acceptable range of neutral to like slightly. Results obtained, revealed that combined treatment of N, CA and CN can provide a solution to reduce the count of Salmonella in QF, whether in process or during storage.


Assuntos
Antibacterianos/farmacologia , Queijo/microbiologia , Microbiologia de Alimentos/métodos , Viabilidade Microbiana/efeitos dos fármacos , Salmonella/efeitos dos fármacos , Caprilatos/farmacologia , Contagem de Colônia Microbiana , Manipulação de Alimentos , Conservação de Alimentos , Nisina/farmacologia
10.
Food Chem ; 308: 125633, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-31644968

RESUMO

The objective of this study was to evaluate the in vitro antimicrobial and antioxidant activities of different bran extracts and concentrations, and their influence on the parameters of a mayonnaise-type emulsion. To that end, first ethanol and then water were used to extract two rice bran extracts (RBE) from rice bran. Both these extracts were then added at two different concentrations (0.5 and 2%) to the emulsions that were subsequently analysed after seven days under two different storage temperatures, 4 °C and 20 °C. The antioxidant and antimicrobial ability of the extracts were evaluated, along with a control and a synthetic antioxidant. Results indicate the positive effect of rice bran extracts as additives in the food matrix. Ethanolic rice bran extract (EE) at 2% decreased the oxidation as well as mould and yeast proliferation and preserved the emulsion structure, while the other treatments acted in a similar way although their effect was less pronounced.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Oryza/química , Extratos Vegetais/farmacologia , Antibacterianos/química , Antioxidantes/química , Condimentos , Emulsões , Escherichia coli/efeitos dos fármacos , Listeria/efeitos dos fármacos , Oxirredução , Extratos Vegetais/química
11.
APMIS ; 128(1): 25-34, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31628820

RESUMO

Eradication failure of Helicobacter pylori infection could play a causal role in progression of gastric disorders. In this study, infection with H. pylori was followed in gastric biopsies of symptomatic adult patients at two phases during 1-year period. Analyses were done to show association of therapeutic regimens with the refractory infection, changes in sequence types (STs) and minimum inhibitory concentration (MIC) values, and progression of histopathological changes. Infection with H. pylori was confirmed in 32.3% (57/170) of the patients. Persistent infection with H. pylori was confirmed in 14 out of the 25 patients (56%) who participated at the second phase of the study. A difference between primary and secondary resistance rates to clarithromycin (49% vs 64.3%), metronidazole (76.36% vs 100%), and ciprofloxacin (45% vs 57.1%) was detected. Although the re-emerged strains in patients with refractory infection did not show alteration in STs, their MIC50 values showed twofold increases for clarithromycin and ciprofloxacin. While ciprofloxacin containing regimens were more successful, failure of metronidazole containing regimens was detected in 77% of the patients. Consequently, inappropriate medication has an impact on refractory H. pylori infection, which could cause to a rise in resistance levels to antibiotics and progression of pathological disorders.


Assuntos
Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana Múltipla , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/patologia , Helicobacter pylori/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Biópsia , Ciprofloxacino/farmacologia , Claritromicina/farmacologia , Feminino , Seguimentos , Técnicas Histológicas , Humanos , Concentração Inibidora 50 , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tipagem de Sequências Multilocus , Estômago/microbiologia , Estômago/patologia
12.
APMIS ; 128(1): 41-47, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31692136

RESUMO

Campylobacteriosis is one of the most frequently reported zoonoses worldwide. The well-documented increase in the ciprofloxacin resistance has increased the importance of rapid detection of the resistance. The incidence of ciprofloxacin resistance was investigated using real-time PCR. Identification of one hundred and fifty-eight strains was performed by PCR. Minimum inhibitory concentration (MIC) of ciprofloxacin was determined by Epsilometer test. Following the confirmation of the efficiencies of singleplex real-time PCR methods using two different probes, a cytosine to thymine point mutation at codon 86 was detected by allelic discrimination. Of the 158 strains, 114 (72.2%) were determined to be resistant to ciprofloxacin. The MIC50 and the MIC90 of ciprofloxacin were found to be 8 and ≥32 mg/L, respectively. By real-time PCR, the presence of the mutation was confirmed in all, but one, resistant strains and the absence of the mutation was demonstrated in all, but one, susceptible strains. The rate of resistance is high among C. jejuni strains and ciprofloxacin should not be used in the treatment of such infections in Turkey. A cytosine to thymine mutation is the most frequently detected mechanism for the resistance. Real-time PCR can be used for the quick screening of the resistance.


Assuntos
Antibacterianos/farmacologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/genética , Ciprofloxacino/farmacologia , Farmacorresistência Bacteriana/genética , Mutação Puntual , Alelos , Infecções por Campylobacter/epidemiologia , Infecções por Campylobacter/microbiologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Eletroforese em Gel de Campo Pulsado , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Fenótipo , Prevalência , Turquia
13.
APMIS ; 128(1): 48-60, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31693234

RESUMO

Klebsiella pneumoniae is an important opportunistic pathogen with significant potential for virulence and multidrug resistance. Treatment failure often occurs because the pathogen may couple virulence and drug resistance with the stringent response. This study assessed the role of the spoT gene in environmental and nutritional stress tolerance, exopolysaccharide capsule production and biofilm formation. spoT mutants were constructed using the lambda red recombinase technique, and mutant and wild-type (WT) strains were exposed to limiting concentrations of carbon (glucose), phosphate and aminoacid, and environmental stresses of ethanol, salt and heat. Cell viability, capsule production and cell length were assessed as well as the ability to grow biofilm under antibiotic pressure using gentamicin and ceftazidime. spoT mutants were more susceptible to stresses versus WT; the reverse was true for survival during biofilm susceptibility assay (p < 0.05), especially when carbon and phosphate were present. spoT mutants were elongated and lacked a capsule versus WT and non-starved strains. The inability to produce capsule in mutants before and after starvation was likely a general effect of spoT mutation. These data suggest that the spoT-mediated stringent response is important for K. pneumoniae in conditions of nutrient limitation, environmental stress and antimicrobial pressure.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/fisiologia , Estresse Fisiológico , Aminoácidos/química , Farmacorresistência Bacteriana , Etanol/farmacologia , Regulação Bacteriana da Expressão Gênica , Glucose/química , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Fosfatos/química , Cloreto de Sódio/farmacologia , Virulência/genética , Fatores de Virulência
14.
Bratisl Lek Listy ; 120(12): 935-940, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31855054

RESUMO

OBJECTIVES: We focused on detecting the most frequent resistance mechanisms in selected multidrug-resistant (MDR) strains and determining their antimicrobial resistance. BACKGROUND: MDR pathogens pose urgent public health threat due to limited treatment options, rigorous control measures and significant mortality. METHODS: We confirmed extended-spectrum ß-lactamase (ESBL) and carbapenemase producing Enterobacteriaceae through guidelines, as well following ß-lactamases: AmpC by cloxacillin, class A carbapenemase with phenylboronic acid, class B metallo-ß-lactamase with ethylenediaminetetraacetic acid. Multilocus sequence typing was used to investigate 20 Escherichia coli strains. RESULTS: Overall 205 mostly ESBL Escherichia coli demonstrated resistance against amikacin (4.7 %), tigecycline (1.2 %), and no resistance to ceftazidime/avibactam, meropenem, nitrofurantoin and fosfomycin. Out of 41 Klebsiella species (spp.), 37 (90.2 %) showed carbapenemase activity, 13 (35.1 %) of class A and 24 (64.9 %) of class B. Resistance was following: meropenem 66.7 %, tigecyclin 10.2 % and colistin 0 %. From Enterobacter spp. 21 strains, 14 (66.7 %) were ESBL, 5 produced ESBL and/or AmpC and 2 were MDR. We ascertained 14 (70 %) E. coli sequence type - ST131. CONCLUSIONS: The study revealed various resistance mechanisms in concert with different agents and association of specific ST131 within E. coli. These characteristics considerably contribute to emergence of antimicrobial resistance (Tab. 4, Ref. 30).


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriaceae/enzimologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Klebsiella pneumoniae/efeitos dos fármacos , beta-Lactamases/metabolismo , Adulto , Idoso , Proteínas de Bactérias/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Farmacorresistência Bacteriana , Enterobacteriaceae/classificação , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , beta-Lactamases/genética
15.
Cell Physiol Biochem ; 53(6): 1015-1028, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31854953

RESUMO

BACKGROUND/AIMS: Pulmonary infections with Pseudomonas aeruginosa (P. aeruginosa) or Staphylococcus aureus (S. aureus) are of utmost clinical relevance in patients with cystic fibrosis, chronic obstructive pulmonary disease, after trauma and burn, upon ventilation or in immuno-compromised patients. Many P. aeruginosa and S. aureus strains are resistant to many known antibiotics and it is very difficult or often impossible to eradicate the pathogens in patient´s lungs. We have recently shown that the sphingoid base sphingosine very efficiently kills many pathogens, including for instance P. aeruginosa, S. aureus or Acinetobacter baumannii, in vitro. In vivo experiments of our group on cystic fibrosis mice indicated that inhalation of sphingosine prevents or eliminates existing acute or chronic pneumonia with P. aeruginosa or S. aureus in these mice. We also demonstrated that sphingosine is safe to use for inhalation up to high doses, at least in mice. To facilitate development of sphingosine to an anti-bactericidal drug that can be used in humans for inhalation, safety data on non-rodents, larger animals are absolutely required. METHODS: Here, we inhaled mini pigs with increasing doses of sphingosine for 10 days and analyzed the uptake of sphingosine into epithelial cells of bronchi as well as into the trachea and lung and the systemic circulation. Moreover, we measured the generation of ceramide and sphingosine 1-phosphate that potentially mediate inflammation, the influx of leukocytes, epithelial cell death and disruption of the epithelial cell barrier. RESULTS: We demonstrate that inhalation of sphingosine results in increased levels of sphingosine in the luminal membrane of bronchi and the trachea, but not in systemic accumulation. Inhaled sphingosine had no side effects up to very high doses. CONCLUSION: In summary, we demonstrate that inhalation of sphingosine results in an increase of sphingosine concentrations in the luminal plasma membrane of tracheal and bronchial epithelial cells. The inhalation has no systemic or local side effects.


Assuntos
Antibacterianos/metabolismo , Esfingosina/metabolismo , Administração por Inalação , Animais , Antibacterianos/farmacologia , Brônquios/metabolismo , Brônquios/patologia , Ceramidas/análise , Humanos , Pulmão/patologia , Lisofosfolipídeos/análise , Espectrometria de Massas , Pseudomonas aeruginosa/efeitos dos fármacos , Esfingosina/análogos & derivados , Esfingosina/análise , Esfingosina/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Suínos , Porco Miniatura , Traqueia/metabolismo , Traqueia/patologia
16.
Zhongguo Zhong Yao Za Zhi ; 44(22): 4864-4873, 2019 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-31872594

RESUMO

Fifteen limonoids were isolated from 95% ethanol extracts of the dry seeds of neem( Azadirachta indica) by various column chromatography techniques including silica gel,Pharmadex LH-20 gel and ODS resin. Based on spectroscopic analysis,their structures were determined as nimbocinol( 1),17ß-hydroxynimbocinol( 2),1α,3α,7α-triacetylvilasinin( 3),7α-benzoyltrichilinin( 4),1,3-diacetyl-7-tigloyl-12-hydroxyvilasinin( 5),3-deacetylsalannin( 6),1-O-acetyl-1-detigloylsalannin( 7),2'( R),3'-dihydrosalannin( 8),2'( S),3'-dihydrosalannin( 9),2,3-dihydronimbolide( 10),6-homodesacetylnimbin( 11),gedunin( 12),7-deacetyl-7-epi-dihydrogedunin( 13),7-deacetoxy-7α-hydroxygedunin( 14) and nimbinene( 15). Compound 7 is a new natural product. 4,8,9,13 and 14 are isolated from the genus Azadirachta for the first time. Compound 2 showed inhibitory activity against Escherichia coli and Staphylococcus epidermidis,with MIC values of 32 and 128 mg·L~(-1),respectively. Compound 10 showed moderate inhibitory activity against S. epidermidis with a MIC value of 64 mg·L~(-1). Compound 11 inhibited the growth of E. coli and Pseudomonas aeruginosa,both with MIC values of 128 mg·L~(-1). Compound 15 exhibited inhibitory activity against P. aeruginosa,with a MIC value of128 mg·L~(-1).


Assuntos
Antibacterianos/farmacologia , Azadirachta , Limoninas , Extratos Vegetais/farmacologia , Escherichia coli , Sementes
17.
Huan Jing Ke Xue ; 40(7): 3263-3269, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854727

RESUMO

The high content of tetracycline in municipal sludge may result in vermicomposting products carrying a high abundance of antibiotic resistance genes, thus lowering the utilization value of the vermicompost. Hence, this study aimed to reveal the underlying effects of tetracycline concentrations on the resistance genes involved in vermicomposting systems for sludge recycling. For this purpose, fresh sludge substrates with different concentrations of tetracycline (100, 500, and 1000 mg·kg-1) were vermicomposted for 60 days using Eisenia foetida. In parallel, sludge treatment without the addition of the tetracycline was used as a control. During the experiment, changes in bacterial communities, tetracycline resistance genes (tetC, tetG, tetM, tetW, and tetX), and class 1 integron (intI1) were detected using high-throughput sequencing and qualitative PCR, respectively. The results showed that the addition of tetracycline reduced the abundance of Proteobacteria but increased the abundance of Bacteroidetes in the sludge vermicompost. Furthermore, the concentrations of tetracycline had a significant negative correlation with Shannon and Pielou indexes of bacterial diversity. In addition, tetracycline increased intI1 genes and tetracycline resistance genes in the sludge by 4.25 times and 4.7-186.9 times, respectively. Moreover, there was a significantly positive correlation between the abundance of tetM genes and tetracycline concentration. This study suggests that higher concentration of tetracycline in sludge can modify the microbial community structure of vermicompost, enhancing the abundance of antibiotic resistance genes and their associated dissemination risks.


Assuntos
Antibacterianos/farmacologia , Compostagem , Resistência Microbiana a Medicamentos/genética , Microbiota , Esgotos/microbiologia , Tetraciclina/farmacologia , Animais , Genes Bacterianos , Oligoquetos , Resistência a Tetraciclina/genética
18.
Huan Jing Ke Xue ; 40(7): 3270-3275, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854728

RESUMO

Municipal sludge contains large amounts of enterococci, which can harbor antibiotic resistance genes (ARGs) and virulence genes (VGs). ARG- and VG-containing enterococci therefore present potential resistance and virulence and, as a consequence, represent a significant health risk to humans. Therefore, the resistance phenotype of enterococci and the prevalence of ARGs and VGs in the enterococci isolated from the mesophilic (40℃) and thermophilic (55℃) anaerobic digestion of thermal hydrolyzed sludge was investigated. Results showed that the enterococci isolated from thermal hydrolyzed sludge showed significantly higher resistance to azithromycin than that to spiramycin and tetracycline. Thermophilic anaerobic digestion resulted in a greater reduction of enterococci abundance (by two orders of magnitude and one order of magnitude, respectively), and a greater reduction in the antibiotic resistance rates of the enterococci. However, thermophilic digestion can promote the expression of tetracycline resistance genes in the enterococci. Furthermore, both mesophilic and thermophilic digestion can facilitate horizontal genes transfer (HGT) between enterococci, which might result in an increase in the occurrence of double- or multiple-resistance. Mesophilic digestion reduced the prevalence of co-occurring ARGs and VGs in enterococci, while thermophilic digestion had the opposite effect. This research improves understanding of the occurrence and fate of ARGs and VGs in potential pathogens during the treatment of municipal sludge.


Assuntos
Resistência Microbiana a Medicamentos/genética , Enterococcus/genética , Genes Bacterianos , Esgotos/microbiologia , Anaerobiose , Antibacterianos/farmacologia , Virulência/genética
19.
Medicine (Baltimore) ; 98(51): e18396, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31861004

RESUMO

Hydrogen formed by small intestinal bacterial overgrowth in patients with non-constipated irritable bowel syndrome has an inverse relationship with obesity. However, the effect of eradicating small intestinal hydrogen-producing bacterial overgrowth on the body weight of these patients has not yet been reported. The aim of this study was to investigate body weight changes after eradicating small intestinal bacterial overgrowth with rifaximin treatment in patients with non-constipated irritable bowel syndrome.We reviewed the charts of patients with non-constipated irritable bowel syndrome who showed abdominal symptoms with documented lactulose hydrogen breath test results in order to diagnose small intestinal bacterial overgrowth. A total of 153 patients were enrolled in the study and divided into quartiles according to body mass index (BMI) and body weight.In the lowest body weight quartile, the BMI and body weight were significantly increased (0.4 kg/m, P = .038; 0.6 kg, P = .010, respectively) in patients with negative lactulose hydrogen breath tests after rifaximin treatment. However, there was no significant change in body weight in the other quartiles. Despite treatment with rifaximin for 12 weeks, there was no change in BMI or body weight in any group of patients with consistently positive lactulose hydrogen breath tests.Eradication of hydrogen formed by small intestinal bacterial overgrowth does not cause clinically significant changes in body weight.


Assuntos
Antibacterianos/uso terapêutico , Peso Corporal/efeitos dos fármacos , Disbiose/tratamento farmacológico , Enteropatias/tratamento farmacológico , Rifaximina/uso terapêutico , Antibacterianos/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rifaximina/farmacologia
20.
Expert Rev Pharmacoecon Outcomes Res ; 19(6): 685-692, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31847613

RESUMO

Introduction: Governments need to do far more to help curb the emergence and transmission of antibiotic resistance and help protect the efficacy of any new antibiotics that come to the market. Industry is an important stakeholder that must be brought on-board such efforts given its influence on the direction and scale of antibiotic sales. Financial incentives supporting industry R&D of novel antibiotics should structurally remove the drivers of superfluous sales and encourage access to newer antibiotics where infections are otherwise resistant to treatment. Indeed, the use of public money provides an important opportunity to prioritize these public health goals within market structures such that we both adequately reward industry for their efforts and prolong antibiotic efficacy for as long as possible.Areas covered: This work discusses possible financial 'pull' incentives that fully delink the reward paid to the developer from unit sales, examining their primary advantages and limitations.Expert opinion: Pharmaceutical companies need to be rewarded generously for their efforts to develop new, badly needed antibiotics. But the current marketplace does not provide a sustained financial lure and its reliance on unit-sales for profitability jeopardizes the efficacy of antibiotics both new and old. Fully delinked models can make antibiotic R&D more financially appealing and create a market environment that is far less threatening to public health.


Assuntos
Antibacterianos/farmacologia , Indústria Farmacêutica/economia , Farmacorresistência Bacteriana , Antibacterianos/economia , Comércio/economia , Desenvolvimento de Medicamentos/economia , Humanos , Saúde Pública/economia , Apoio à Pesquisa como Assunto/economia
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