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2.
BMC Infect Dis ; 21(1): 1099, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34702193

RESUMO

BACKGROUND: Pharmacokinetic-pharmacodynamic (PK/PD) targets of vancomycin therapy have been recognized for methicillin-resistant Staphylococcus aureus infections but not for other gram-positive bacterial infections. Therefore, we investigated whether vancomycin concentration targets such as the trough level and ratio of the area under the curve to minimum inhibitory concentration (AUC/MIC) are associated with the treatment outcome in enterococcal bacteremia. METHODS: A retrospective cohort analysis enrolled patients with bacteremia caused by vancomycin-susceptible Enterococcus faecium and Enterococcus faecalis who were treated with vancomycin from January 2007 to December 2017 at a tertiary hospital located in Seoul, South Korea. Patients without vancomycin concentrations were excluded from the study. The primary outcome was 28-day all-cause mortality. RESULTS: A total of 37 patients were enrolled-26 with E. faecium infection and 11 with E. faecalis infection. The 28-day all-cause mortality rate was 21.6 %. In univariate analysis, vancomycin trough level (≤ 15 µg/mL; p = 0.042), age (p = 0.044), and septic shock (p = 0.049) were associated with 28-day mortality but not AUC24/MIC (> 389; p = 0.479). In multivariate analysis, vancomycin trough concentration (≤ 15 µg/mL; p = 0.041) and younger age (p = 0.031) were associated with 28-day mortality in patients with enterococcal bacteremia. CONCLUSIONS: In this study, a vancomycin trough level of 15 µg/mL or lower was associated with 28-day mortality in enterococcal bacteremia. However, relatively large prospective studies are needed to examine the efficacy of vancomycin PK/PD parameters in patients with enterococcal bacteremia.


Assuntos
Bacteriemia , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Enterococcus , Humanos , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Infecções Estafilocócicas/tratamento farmacológico , Resultado do Tratamento , Vancomicina/uso terapêutico
3.
Poult Sci ; 100(11): 101455, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34607145

RESUMO

We used an embryo lethality assay (ELA) to assess virulence for different isolates from cases of bacterial chondronecrosis with osteomyelitis (BCO) in broilers. Lameness is among the most significant animal welfare issues in the poultry industry. Bacterial infections are a major cause of lameness and different bacterial species have been obtained from lame broilers. Reliable lab-based assays are required to assess relative virulence of bacteria obtained from lame broilers. ELA has been used to assess lethal dosage of Enterococcus faecalis and Enterococcus cecorum. We hypothesized that ELA could substitute for more laborious and costly assessments of BCO isolate pathogenicity using live birds. We evaluated 2 different levels of bacteria injected into eggs from layer and commercial broiler embryos. Significant findings include 1) Escherichia coli from neighboring farms operated by the same integrator had very different embryo lethality, 2) isolate Staphylococcus agnetis 908 had low virulence in ELA, even though this isolate can induce more than 50% BCO lameness, 3) Enterococcus cecorum 1415 also had low pathogenicity; even though it was recovered from severe bilateral tibial dyschondroplasia, 4) human and chicken BCO isolates of S. aureus had significant pathogenicity, 5) virulence for some isolates was highly variable possibly corresponding with quality of the embryos/fertile eggs used, and 6) ELA pathogenicity was much lower for our BCO isolates than previous reports which may reflect maternal environment. Overall, ELA virulence and BCO virulence are not always concordant indicating that ELA may not be an effective measure for assessing virulence with respect to BCO.


Assuntos
Infecções Bacterianas , Osteomielite , Doenças das Aves Domésticas , Animais , Infecções Bacterianas/veterinária , Galinhas , Enterococcus , Coxeadura Animal , Necrose/veterinária , Osteomielite/veterinária , Óvulo , Staphylococcus , Staphylococcus aureus , Virulência
4.
J Am Anim Hosp Assoc ; 57(6): 290-293, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34606588

RESUMO

A 13 yr old spayed female Yorkshire terrier was hospitalized for a dull mentation, anorexia, presumptive gastroenterocolitis, and a suspected gastrointestinal bleed with melena. Despite supportive therapy, the patient's clinical signs persisted. Throughout hospitalization, the patient became progressively dull to stuporous with a progressive hypernatremia. On day 3 of hospitalization, the patient acutely developed neurological signs with a neuroanatomical localization consistent with a process at the caudal cranial fossa. Per the owner's wishes, the patient was euthanized with necropsy performed. Histopathology revealed a suppurative meningoencephalitis, ventriculitis, hypophysitis, otitis interna, and an ulcerative pharyngitis. Aerobic culture collected from the area of the pituitary gland grew an Enterococcus spp. Enterococcal meningoencephalitis is rare in humans but has not been reported in veterinary medicine. In future cases of canine bacterial meningitis, Enterococcus spp. should be considered. Because of the inherent resistance patterns of Enterococcus spp., targeted antibiotic selection would be required for treatment.


Assuntos
Ventriculite Cerebral , Doenças do Cão , Hipofisite , Meningoencefalite , Animais , Ventriculite Cerebral/veterinária , Doenças do Cão/diagnóstico , Doenças do Cão/tratamento farmacológico , Cães , Enterococcus , Feminino , Humanos , Hipofisite/veterinária , Meningoencefalite/diagnóstico , Meningoencefalite/tratamento farmacológico , Meningoencefalite/veterinária
5.
Arch Microbiol ; 203(9): 5683-5694, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34468805

RESUMO

In the present study, metabolic characteristics, such as lactic acid, hydrogen peroxide, exopolysaccharide (EPS) production, and antimicrobial activities, of 17 Enterococcus faecium isolates from white cheese samples were assessed. In E. faecium isolates, the amount of lactic acid obtained between in MRS medium 0.61-1.22% and in skim milk 0.75-1.08%, and the amount of H2O2 was found between 0.57 and 3.17 µg mL-1. In MRS and skim milk, the amount of EPS production was 59-185 mg L-1, 155-255 mg L-1 for isolates, respectively. The antimicrobial activities of E. faecium isolates on eight different pathogenic bacteria were also performed by an agar well diffusion method. The highest inhibition zones 8.60 mm were observed with culture supernatants of RI-71 isolate against Escherichia coli ATCC 35218. The safety of the E. faecium isolates was assessed by determining gelatinase activity, hemolytic activity, the resistance to ten different antibiotics, biofilm forming, and virulence genes (van A, van B, gelE, cylA, cylB, esp, agg, and asa1, efaAfm, cob, ccf, hyl). The isolates did not show gelatinase activity, ß-hemolysis, and biofilm formation. All E. faecium isolates were susceptible to vancomycin, penicillin-G, tetracycline, ampicillin, and chloramphenicol. The efaAfm gene was detected most frequently (94%) followed by cob (82%), van B (59%), and ccf (53%). For enterococci to be recommended as co-starter or probiotic adjunct cultures, it is necessary to determine whether they have virulence genes and resistance to antibiotics.


Assuntos
Enterococcus faecium , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Enterococcus , Enterococcus faecium/genética , Peróxido de Hidrogênio , Testes de Sensibilidade Microbiana , Fatores de Virulência/genética
6.
World J Microbiol Biotechnol ; 37(10): 172, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34518944

RESUMO

The focus of the present study was to characterize antimicrobial peptide produced by potential probiotic cultures of Enterococcus durans DB-1aa (MCC4243), Lactiplantibacillus plantarum Cu2-PM7 (MCC4246) and Limosilactobacillus fermentum Cu3-PM8 (MCC4233) against Staphylococus aureus MTCC 96 and Escherichia coli MTCC118. The growth kinetic assay revealed 24 h of incubation to be optimum for bacteriocin production. The partially purified compound of all the three selected cultures after ion-exchange chromatography was found to be thermoresistant and stable under a wide range of pH. The compound was sensitive to proteinase-K, but resistant to trypsin, α-amylase and lipase. Comparatively, bacteriocins from L. fermentum Cu3-PM8 and L. plantarum Cu2-PM7 showed higher stability under studied parameter, hence was taken up for further investigation. The apparent molecular weight of bacteriocin from L. fermentum MCC4233 and L. plantarum MCC4246 was found to be 3.5 kDa. Further, plantaricin gene from MCC4246 was characterized in silico. The translated partial amino acid sequence of the plnA gene in MCC4246 displayed 48 amino acids showing 100 % similarity with plantaricin A of Lactobacillus plantarum (WP_0036419). The sequence revealed 7 ß sheets, 6 α sheets, 6 predicted coils and 9 predicted turns. The predicted properties of the peptide included an isoelectric point of 10.82 and a hydrophobicity of 48.6 %. The molecular approach of using Geneious Prime software and protein prediction data base for characterization of bacteriocin is novel and predicts "KSSAYSLQMGATAIKQVKKLFKKWGW" to be a peptide responsible for antimicrobial activity. The study provides information about a broad spectrum bacteriocin in native probiotic culture and paves a way towards its application in functional foods as a biopreservative agent.


Assuntos
Antibacterianos/farmacologia , Enterococcus/química , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Probióticos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Sequência de Aminoácidos , Antibacterianos/química , Antibacterianos/metabolismo , Simulação por Computador , Enterococcus/genética , Enterococcus/metabolismo , Peso Molecular , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Probióticos/química , Probióticos/metabolismo , Staphylococcus aureus/crescimento & desenvolvimento
7.
Molecules ; 26(18)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34577049

RESUMO

A novel family of [1,4]thiazino[2,3,4-ij]quinolin-4-ium derivatives was synthesized by annulation reactions of 8-quinolinesulfenyl chloride with unsaturated heteroatom and heterocyclic compounds. It was found that the reactions with 4-pentenoic and 5-hexenoic acids, allyl chloride and bromide, allyl cyanate and vinyl heterocyclic compounds (N-vinyl pyrrolidin-2-one and 1-vinylimidazole) proceeded in a regioselective mode but with the opposite regiochemistry. The reactions with vinyl heterocyclic compounds included electrophilic addition of the sulfur atom of 8-quinolinesulfenyl chloride to the ß-carbon atom of the vinyl group. In the case of other substrates, the annulation proceeded with the attachment of the sulfur atom to the α-carbon atom of the vinyl group. The antibacterial activity of novel water-soluble compounds against Enterococcus durans, Bacillus subtilis and Escherichia coli was evaluated. Compounds with high antibacterial activity were found.


Assuntos
Antibacterianos , Enterococcus , Compostos Heterocíclicos , Anti-Infecciosos , Enxofre/química
8.
PLoS One ; 16(9): e0257681, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34543338

RESUMO

Anti-nutritional compounds such as non-starch polysaccharides (NSP) are present in viscous cereals used in feed for poultry. Therefore, exogenous carbohydrases are commonly added to monogastric feed to degrade these NSP. Our hypothesis is that xylanase not only improves laying hen performance and digestibility, but also induces a significant shift in microbial composition within the intestinal tract and thereby might exert a prebiotic effect. In this context, a better understanding on whether and how the chicken gut microbial population can be modulated by xylanase is required. To do so, the effects of dietary supplementation of xylanase on performance, apparent total tract digestibility (ATTD) and cecal microbiome in laying hens were evaluated in the present study. A total of 96 HiSex laying hens were used in this experiment (3 diets and 16 replicates of 2 hens). Xylanase was added to the diets at concentrations of 0, 45,000 (15 g/t XygestTM HT) and 90,000 U/kg (30 g/t Xygest HT). The diets were based on wheat (~55%), soybean and sunflower meal. The lowest dosage, 45,000 U/kg, significantly increased average egg weight and improved feed efficiency compared to the control treatment (P<0.05). Egg quality parameters were significantly improved in the experiment in response to the xylanase addition. For example, during the last 28 days of the trial, birds receiving the 45,000 U/kg and the 90,000 U/kg treatments exhibited an increase in Haugh units and albumin heights (P<0.05). Compared with the control, the ATTD of organic matter and crude protein were drastically improved in the 45,000 U/kg treatment group (P<0.05). Furthermore, gross energy and the ATTD of crude fat were improved significantly for birds fed 90,000 U/kg group compared to the control. Importantly, 16S rRNA gene analysis revealed that xylanase at 45,000 U/kg dosage can exert a change in the cecal microbiome. A significant increase in beneficial bacteria (Bacilli class; Enterococcaceae and Lactobacillales orders; Merdibacter, Enterococcus and Nocardiopsis genera; Enterococcus casseliflavus species) was documented when adding 45,000 U/kg xylanase to the diet of laying hens. In conclusion, dietary supplementation of xylanase 45,000 U/kg significantly improved laying hen performance and digestibility. Furthermore, microbiome data suggest that xylanase modulates the laying hen bacterial population beneficially, thus potentially exerting a prebiotic effect.


Assuntos
Galinhas , Ração Animal , Animais , Dieta , Digestão , Enterococcus , RNA Ribossômico 16S
9.
Arch Microbiol ; 203(10): 6267-6274, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34581832

RESUMO

In this study, we screened bacterial strains to identify specific probiotics to treat pig diarrhea caused by Escherichia coli or Salmonella. The potential probiotics were assayed for their survival in gastrointestinal solution, their antimicrobial activity, cell-surface properties, adhesion to Caco-2 cells, and inhibition of pathogen adhesion. Nine out of the 20 strains tested showed high tolerance of a simulated gastrointestinal environment and six strains exerted antagonistic effects against enterohemorrhagic E. coli (EHEC) O157:H7 and Salmonella Typhimurium MQ. Lactobacillus johnsonii pDX1e exhibited a higher potent antibacterial activity. Four strains (pDX1a, pDX1e, pDX3a, and pDX5a) displayed auto-aggregation, hydrophobicity, and adhesion to Caco-2 cells similar to those of the reference strain Lacticaseibacillus rhamnosus GG (LGG). Enterococcus durans pDX5a showed the highest adhesion capacity (13.86%), followed by the reference strain LGG (11.20%). All the tested strains competitively suppressed the attachment of pathogens to Caco-2 cells (by 30.73-55.18%); L. johnsonii pDX1e and Ent. durans pDX5a significantly inhibited the adhesion of pathogens by substitution and exclusion, respectively. Therefore, pDX1e and pDX5a were selected as probiotic strains for further investigation and application.


Assuntos
Escherichia coli O157 , Probióticos , Animais , Aderência Bacteriana , Células CACO-2 , Enterococcus , Humanos , Lactobacillus , Salmonella typhimurium , Suínos
10.
Sci Total Environ ; 801: 149763, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34438135

RESUMO

Solar driven advanced oxidation processes (AOPs) (an alternative solar photo Fenton like process (SPF), sunlight/H2O2 (SHP) and sunlight/chlorine (SCL)) and respective dark conditions, were compared for the first time to conventional (chlorination and UV-C radiation) disinfection processes, in the inactivation of E. coli and Entero strains inoculated in real roof-harvested rainwater (RHRW), to evaluate their possible safe use for crop irrigation. In this regard, bacterial regrowth was also evaluated 6, 12, 24 and 48 h after disinfection treatment. The SPF, using iminodisuccinic acid (IDS)-Cu complex as catalyst, was optimized (H2O2/IDS-Cu 55/1 best molar ratio) under mild conditions (spontaneous pH) and sunlight. The faster inactivation kinetics were observed for the SCL process (k = 1.473 min-1, t1/2 = 0.47 min for E. coli and k = 1.193 min-1, t1/2 = 0.57 min for Entero), while the most effective processes in controlling bacterial regrowth were SPF and SCL. Although UV-C radiation (0-1.3 × 104 µW s cm-2 dose range) was the second faster disinfection process (k = 1.242 min-1, t1/2 = 0.55 min for E. coli and k = 1.150 min-1, t1/2 = 0.60 min for Entero), it was the less effective process in controlling bacterial regrowth (>10 CFU 100 mL-1 already after 6 h post-treatment incubation). According to the bacterial inactivation and regrowth tests carried out in this work, SPF and SCL are interesting options for RHRW disinfection, in case of effluent use for crop irrigation.


Assuntos
Desinfecção , Purificação da Água , Enterococcus , Escherichia coli , Peróxido de Hidrogênio , Luz Solar , Águas Residuárias
11.
Science ; 373(6558): 1040-1046, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34446607

RESUMO

The antitumor efficacy of cancer immunotherapy can correlate with the presence of certain bacterial species within the gut microbiome. However, many of the molecular mechanisms that influence host response to immunotherapy remain elusive. In this study, we show that members of the bacterial genus Enterococcus improve checkpoint inhibitor immunotherapy in mouse tumor models. Active enterococci express and secrete orthologs of the NlpC/p60 peptidoglycan hydrolase SagA that generate immune-active muropeptides. Expression of SagA in nonprotective E. faecalis was sufficient to promote immunotherapy response, and its activity required the peptidoglycan sensor NOD2. Notably, SagA-engineered probiotics or synthetic muropeptides also augmented anti-PD-L1 antitumor efficacy. Taken together, our data suggest that microbiota species with specialized peptidoglycan remodeling activity and muropeptide-based therapeutics may enhance cancer immunotherapy and could be leveraged as next-generation adjuvants.


Assuntos
Antígeno B7-H1/antagonistas & inibidores , Enterococcus/metabolismo , Inibidores de Checkpoint Imunológico/uso terapêutico , Melanoma Experimental/terapia , N-Acetil-Muramil-L-Alanina Amidase/metabolismo , Peptidoglicano/metabolismo , Animais , Carga Bacteriana , Proteínas de Bactérias/metabolismo , Enterococcus/enzimologia , Enterococcus faecalis/metabolismo , Enterococcus faecium/metabolismo , Microbioma Gastrointestinal , Imunoterapia , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Proteína Adaptadora de Sinalização NOD2/metabolismo , Fragmentos de Peptídeos/metabolismo , Probióticos , Transdução de Sinais
12.
Biomolecules ; 11(7)2021 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-34356651

RESUMO

In recent years, multidrug-resistant (MDR) bacteria have increased rapidly, representing a major threat to human health. This problem has created an urgent need to identify alternatives for the treatment of MDR bacteria. The aim of this study was to identify the antibacterial activity of selenium nanoparticles (SeNPs) and selenium nanowires (SeNWs) against MDR bacteria and assess the potential synergistic effects when combined with a conventional antibiotic (linezolid). SeNPs and SeNWs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), zeta potential, and UV-visible analysis. The antibacterial effects of SeNPs and SeNWs were confirmed by the macro-dilution minimum inhibitory concentration (MIC) test. SeNPs showed MIC values against methicillin-sensitive S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), vancomycin-resistant S. aureus (VRSA), and vancomycin-resistant enterococci (VRE) at concentrations of 20, 80, 320, and >320 µg/mL, respectively. On the other hand, SeNWs showed a MIC value of >320 µg/mL against all tested bacteria. Therefore, MSSA, MRSA, and VRSA were selected for the bacteria to be tested, and SeNPs were selected as the antimicrobial agent for the following experiments. In the time-kill assay, SeNPs at a concentration of 4X MIC (80 and 320 µg/mL) showed bactericidal effects against MSSA and MRSA, respectively. At a concentration of 2X MIC (40 and 160 µg/mL), SeNPs showed bacteriostatic effects against MSSA and bactericidal effects against MRSA, respectively. In the synergy test, SeNPs showed a synergistic effect with linezolid (LZD) through protein degradation against MSSA and MRSA. In conclusion, these results suggest that SeNPs can be candidates for antibacterial substitutes and supplements against MDR bacteria for topical use, such as dressings. However, for use in clinical situations, additional experiments such as toxicity and synergistic mechanism tests of SeNPs are needed.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Selênio/farmacologia , Antibacterianos/química , Proteínas de Bactérias/metabolismo , Contagem de Colônia Microbiana , Sinergismo Farmacológico , Enterococcus/efeitos dos fármacos , Linezolida/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/metabolismo , Testes de Sensibilidade Microbiana , Nanopartículas , Nanofios/química , Selênio/química , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Environ Sci Pollut Res Int ; 28(36): 50941-50965, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34386920

RESUMO

Coastal water quality in urban cities is increasingly impacted by human activities such as agricultural runoff, sewage discharges, and poor sanitation. However, environmental factors controlling bacteria abundance remain poorly understood. The study employed multiple indicators to assess ten beach water qualities in Ghana during minor wet seasons. Environmental parameters (e.g. temperature, electrical conductivity, total dissolved solids) were measured in situ using the Horiba multiple parameter probe. Surface water samples were collected to measure total suspended solids, nutrients, and chlorophyll-a via standard methods and bacteria determination through membrane filtration. Environmental parameters measured showed no significant variation for the sample period. However, bacteria loads differ significantly (p = 0.024) among the beaches and influenced significantly by nitrate (55.3%, p = 0.02) and total dissolved solids (17.1%, p = 0.017). The baseline study detected an increased amount of total coliforms and faecal indicator bacteria (Escherichia coli and Enterococcus spp.) in beach waters along the coast of Ghana, suggesting faecal contamination, which can pose health risks. The mean ± standard deviations of bacteria loads in beach water are total coliforms (4.06 × 103 ± 4.16 × 103 CFU/100 mL), E. coli (7.06 × 102 ± 1.72 × 103 CFU/100 mL), and Enterococcus spp. (6.15 × 102 ± 1.75 × 103 CFU/100 mL). Evidence of pollution calls for public awareness to prevent ecological and health-related risks and policy reforms to control coastal water pollution. Future research should focus on identifying the sources of contamination in the tropical Atlantic region.


Assuntos
Enterococcus , Escherichia coli , Bactérias , Biomarcadores , Monitoramento Ambiental , Fezes , Humanos , Saúde Pública , Microbiologia da Água
14.
Waste Manag ; 134: 32-41, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34403994

RESUMO

This study examined the combined effect of hydraulic retention time (HRT), organic loading rate (OLR) and heat pretreatment of manure (70 °C, 1 h) on the fate of E. coli, enterococci, C. perfringens, C. difficile, and on chemical parameters (volatile fatty acids and ammonia) that may inactivate pathogens. Semi-continuous mesophilic anaerobic reactors were fed with pig manure and horse feed. The operating conditions were 2, 3, 4 COD.L-1.d-1 (OLR), 24, 35, 46 days (HRT) and use or not of a thermal pretreatment. The levels of the chemical parameters did not reach concentrations capable of inactivating the four bacteria. Anaerobic digestion led to a Log10 removal > 3 (E. coli), 0.9-2.1 (enterococci), 0.1-0.6 (C. perfringens) and 0-1 (C. difficile). Increasing HRT only reduced the concentration of E. coli in the digestate. Increasing OLR reduced the Log10 removal of enterococci and C. difficile. The heat pretreatment led to non-detection of E. coli in the digestate, reduced the concentration of C. perfringens by 0.8-1.3 Log10 and increased the concentration of C. difficile by 0.04-0.7 Log10. Enterococci, not detected in the heated manure, were present in the digestate. The distribution of genes encoding virulence factors of C. difficile (tcdA and tcdB) and C. perfringens (cpa, cpb2 and cpb) was not impacted by anaerobic digestion or by the heat pretreatment. Enterococci, C. perfringens, C. difficile were present in the digestate at relatively stable concentrations regardless of the operating conditions, indicating that even with heat pretreatment, the biosafety of digestate cannot be guaranteed in mesophilic conditions.


Assuntos
Toxinas Bacterianas , Clostridioides difficile , Anaerobiose , Animais , Reatores Biológicos , Clostridioides , Clostridium perfringens , Enterococcus , Escherichia coli , Cavalos , Esterco , Metano , Suínos
15.
Artigo em Inglês | MEDLINE | ID: mdl-34402778

RESUMO

Enterococcus lactis and the heterotypic synonym Enterococcus xinjiangensis from dairy origin have recently been identified as a novel species based on 16S rRNA gene sequence analysis. Enterococcus faecium type strain NCTC 7171T was used as the reference genome for determining E. lactis and E. faecium to be separate species. However, this taxonomic classification did not consider the diverse lineages of E. faecium, and the double nature of hospital-associated (clade A) and community-associated (clade B) isolates. Here, we investigated the taxonomic relationship among isolates of E. faecium of different origins and E. lactis, using a genome-based approach. Additional to 16S rRNA gene sequence analysis, we estimated the relatedness among strains and species using phylogenomics based on the core pangenome, multilocus sequence typing, the average nucleotide identity and digital DNA-DNA hybridization. Moreover, following the available safety assessment schemes, we evaluated the virulence profile and the ampicillin resistance of E. lactis and E. faecium clade B strains. Our results confirmed the genetic and evolutionary differences between clade A and the intertwined clade B and E. lactis group. We also confirmed the absence in these strains of virulence gene markers IS16, hylEfm and esp and the lack of the PBP5 allelic profile associated with ampicillin resistance. Taken together, our findings support the reassignment of the strains of E. faecium clade B as E. lactis.


Assuntos
Infecção Hospitalar , Enterococcus faecium , Enterococcus/classificação , Filogenia , Antibacterianos , Técnicas de Tipagem Bacteriana , Composição de Bases , Infecção Hospitalar/microbiologia , DNA Bacteriano/genética , Enterococcus faecium/classificação , Ácidos Graxos/química , Humanos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
16.
Antimicrob Agents Chemother ; 65(10): e0108321, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34252296

RESUMO

Linezolid is an important last-resort antibiotic for the treatment of multidrug-resistant enterococci. The aim of this study was to further characterize the genetic context of optrA and poxtA in 10 florfenicol-resistant enterococci isolated from flowing surface water. In most genomes, optrA and poxtA were embedded in transposition units integrated into plasmids or into the chromosomal radC. For the first time, a chromosomally integrated optrA in an Enterococcus raffinosus isolate is described.


Assuntos
Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Enterococcus , Enterococcus faecalis , Humanos , Suíça , Tianfenicol/análogos & derivados , Água
17.
Sci Rep ; 11(1): 13858, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226601

RESUMO

The disease caused by Enterococcus lacertideformus is multisystemic and ultimately fatal. Since its emergence, the bacterium has significantly impacted the captive breeding programs of the extinct in the wild Christmas Island Lister's gecko (Lepidodactylus listeri) and blue-tailed skink (Cryptoblepharus egeriae). The bacterium's pathogenicity, inability to grow in-vitro, and occurrence beyond the confines of Christmas Island necessitated the development of an experimental infection and treatment model. Asian house geckos (Hemidactylus frenatus) were challenged with a single dose of E. lacertideformus inoculum either by mouth, application to mucosal abrasion or skin laceration, subcutaneous injection, coelomic injection, or via co-housing with an infected gecko. Five healthy geckos acted as controls. Each transmission route resulted in disease in at least 40% (n = 2) geckos, expanding to 100% (n = 5) when E. lacertideformus was applied to skin laceration and mucosal abrasion groups. Incubation periods post-infection ranged between 54 and 102 days. To determine the efficacy of antibiotic treatment, infected geckos were divided into six groups (enrofloxacin 10 mg/kg, per os (PO), every 24 h (q24), amoxicillin-clavulanic acid 10 mg/kg, PO, q24, enrofloxacin 10 mg/kg combined with amoxicillin-clavulanic acid 10 mg/kg, PO, q24, rifampicin 15 mg/kg, PO, q24, clarithromycin 15 mg/kg, PO, q24, and untreated controls) for 21 days. Response to treatment was assessed by the change in lesion size, bacterial dissemination, and histological evidence of a host immune response. Irrespective of the antibiotic given, histology revealed that geckos inoculated by skin laceration were observed to have more extensive disease spread throughout the animal's body compared to other inoculation routes. The reduction in the average surface area of gross lesions was 83.6% for geckos treated with enrofloxacin, followed by the combination therapy amoxicillin-clavulanic acid and enrofloxacin (62.4%), amoxicillin-clavulanic acid (58.2%), rifampicin (45.5%), and clarithromycin (26.5%). Lesions in geckos untreated with antibiotics increased in size between 100 and 300%. In summary, enrofloxacin and amoxicillin-clavulanic acid show promising properties for the treatment of E. lacertideformus infection in geckos. The Asian house gecko E. lacertideformus infection model therefore provides foundational findings for the development of effective therapeutic treatment protocols aimed at conserving the health of infected and at-risk reptiles.


Assuntos
Antibacterianos/farmacologia , Infecções Bacterianas/microbiologia , Enterococcus/patogenicidade , Lagartos/microbiologia , Combinação Amoxicilina e Clavulanato de Potássio/farmacologia , Animais , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/transmissão , Claritromicina/farmacologia , Modelos Animais de Doenças , Enrofloxacina/farmacologia , Humanos
18.
Water Res ; 202: 117403, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34274900

RESUMO

The presence of antibiotic resistance in wastewater sparked a great interest in investigating the inactivation of antibiotic-resistant bacteria by disinfecting agents. In this study, the inactivation kinetics of multidrug-resistant E. coli and enterococci by an emerging environmentally-friendly disinfectant, peracetic acid (PAA), in wastewater and phosphate buffer at pH 6.5 and pH 7.5, were characterized. It was demonstrated that the inactivation of the studied multidrug-resistant bacteria was governed by their exposure to PAA, i.e., integral of the PAA concentration over time (integral CT or ICT). Both regimes of the PAA inactivation of bacteria, i.e., initial resistance followed by a faster inactivation, were described well by an ICT-based Chick-Watson inactivation kinetic model. In wastewater at pH 7.5, the model-predicted ICT requirements showed that the multidrug-resistant enterococci were less susceptible to PAA than E. coli, e.g., to achieve a 3-log reduction, an ICT of 32.7 mg min/L and 23.4 mg min/L was needed, respectively. No regrowth of the studied bacteria was observed after 72 h from PAA disinfection at 25 ± 1 °C. Soluble constituents of wastewater decreased the PAA inactivation of both multidrug-resistant bacteria, i.e., higher inactivation was observed in phosphate buffer than wastewater at the same pH of 7.5. In phosphate buffer, a lower pH of 6.5 resulted in higher inactivation of multidrug-resistant E. coli compared with pH 7.5, but it did not affect the PAA inactivation of multidrug-resistant enterococci. A comparison with the most commonly used chemical disinfectant, chlorine, showed higher inactivation of both multidrug-resistant bacteria by chlorine and higher chlorine decay than PAA. The results of the present study may have implications in designing a PAA disinfection process, aiming at controlling antibiotic resistance, in terms of selecting a suitable fecal indicator and optimizing disinfectant dosing.


Assuntos
Desinfetantes , Purificação da Água , Cloro , Desinfetantes/farmacologia , Desinfecção , Enterococcus , Escherichia coli , Cinética , Ácido Peracético/farmacologia , Águas Residuárias
19.
Sci Total Environ ; 793: 148641, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34328980

RESUMO

An increase in the number of advisories issued for recreational beaches across south Florida (due to the fecal indicator bacteria, enterococci) has been observed in recent years. To evaluate the possible reasons for this increase, we reviewed weekly monitoring data for 18 beaches in Miami-Dade County, Florida, for the years 2000-2019. Our objective was to evaluate this dataset for trends in enterococci levels and correlations with various factors that might have influenced enterococci levels at these beaches. For statistical analyses, we divided the 20-year period of record into 5-year increments (2000-2004, 2005-2009, 2010-2014, and 2015-2019). The Wilcoxon rank sum test was used to identify statistically significant differences between the geometric mean of different periods. When all 18 beaches were collectively considered, a significant increase (p = 0.03) in enterococci was observed during 2015-2019, compared to the prior 15-year period of record. To better understand the potential causes for this increase, correlations were evaluated with environmental parameters (rainfall, air temperature, and water temperature), global oceanic changes (sea level and Sargassum), community populations (county population estimates and beach visitation numbers), and wastewater infrastructure (sewage effluent flow rates to ocean outfalls and deep well injection). In relation to the enterococci geometric mean, the correlation with Sargassum was statistically significant at a 95% confidence interval (p = 0.035). Population (p = 0.078), air temperature (p = 0.092), and sea level (p = 0.098) were statistically significant at 90% confidence intervals. Rainfall, water temperature, beach visitation numbers, and sewage effluent flow rates via deep well injection had positive correlations but were not significant factors. Sewage effluent flow rates to ocean outfalls had a negative correlation.


Assuntos
Praias , Enterococcus , Monitoramento Ambiental , Fezes , Água do Mar , Águas Residuárias , Microbiologia da Água
20.
ACS Infect Dis ; 7(8): 2445-2454, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34265205

RESUMO

Enterococcal cytolysin is a hemolytic virulence factor linked to human disease and increased patient mortality. Produced by pathogenic strains of Enterococcus faecalis, cytolysin is made up of two small, post-translationally modified peptides called CylLL" and CylLS". They exhibit a unique toxicity profile where lytic activity is observed for both mammalian cells and Gram-positive bacteria that is dependent on the presence of both peptides. In this study, we performed alanine substitution of all residues in CylLL" and CylLS" and determined the effect on both activities. We identified key residues involved in overall activity and residues that dictate cell type specificity. All (methyl)lanthionines as well as a Gly-rich hinge region were critical for both activities. In addition, we investigated the binding of the two subunits to bacterial cells suggesting that the large subunit CylLL" has stronger affinity for the membrane or a target molecule therein. Genome mining identified other potential two-component lanthipeptides and provided insights into potential evolutionary origins.


Assuntos
Enterococcus faecalis , Enterococcus , Animais , Citotoxinas , Enterococcus faecalis/genética , Humanos , Relação Estrutura-Atividade , Fatores de Virulência/genética
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