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1.
Nature ; 574(7776): 117-121, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31534227

RESUMO

Immediately after birth, newborn babies experience rapid colonization by microorganisms from their mothers and the surrounding environment1. Diseases in childhood and later in life are potentially mediated by the perturbation of the colonization of the infant gut microbiota2. However, the effects of delivery via caesarean section on the earliest stages of the acquisition and development of the gut microbiota, during the neonatal period (≤1 month), remain controversial3,4. Here we report the disrupted transmission of maternal Bacteroides strains, and high-level colonization by opportunistic pathogens associated with the hospital environment (including Enterococcus, Enterobacter and Klebsiella species), in babies delivered by caesarean section. These effects were also seen, to a lesser extent, in vaginally delivered babies whose mothers underwent antibiotic prophylaxis and in babies who were not breastfed during the neonatal period. We applied longitudinal sampling and whole-genome shotgun metagenomic analysis to 1,679 gut microbiota samples (taken at several time points during the neonatal period, and in infancy) from 596 full-term babies born in UK hospitals; for a subset of these babies, we collected additional matched samples from mothers (175 mothers paired with 178 babies). This analysis demonstrates that the mode of delivery is a significant factor that affects the composition of the gut microbiota throughout the neonatal period, and into infancy. Matched large-scale culturing and whole-genome sequencing of over 800 bacterial strains from these babies identified virulence factors and clinically relevant antimicrobial resistance in opportunistic pathogens that may predispose individuals to opportunistic infections. Our findings highlight the critical role of the local environment in establishing the gut microbiota in very early life, and identify colonization with antimicrobial-resistance-containing opportunistic pathogens as a previously underappreciated risk factor in hospital births.


Assuntos
Cesárea/efeitos adversos , Microbioma Gastrointestinal , Doenças do Recém-Nascido/microbiologia , Transmissão Vertical de Doença Infecciosa/prevenção & controle , Infecções Oportunistas/congênito , Infecções Oportunistas/microbiologia , Feminino , Humanos , Recém-Nascido , Doenças do Recém-Nascido/etiologia , Infecções Oportunistas/etiologia , Gravidez
4.
Microb Pathog ; 133: 103545, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31112772

RESUMO

Commensal enteric microbes under specific conditions viz. immunocompromised system, altered microbiota or uncompetitive niche induce their otherwise dormant pathogenic phenotype to distort host cellular functioning. Here we investigate how under in vitro environment established by using Caco-2 cells, commensal gut microbe E. coli K12 (ATCC 14849) disrupt intestinal epithelial barrier function. Caco-2 cells exposed to E. coli showed the time dependent significant (P < 0.01) decrease in transepithelial electrical resistance (TEER) and concomitantly increased phenol red flux across cell monolayer in contrast to non infected control cells. E. coli infected intestinal cells were observed with suppressed (p < 0.05) mRNA levels of ZO-1, Claudin-1, Occludin and Cingulin-1 in contrast to significantly (p < 0.05) higher PIgR and hbd-2 mRNA fold changes. Immunofluorescent and electron micrographs revealed the disrupted distribution and localisation of specific tight junction proteins (Zo-1 and Claudin-1) and actin filament in E. coli infected Caco-2 cells that ultimately resulted in deformed cellular morphology. Taken together, E. coli K12 under compromised in vitro milieu disrupted the intestinal barrier functions by decreasing the expression of important tight junction genes along with the altered distribution of associated proteins that increased the intestinal permeability as reflected by phenol red flux and TEER values.


Assuntos
Escherichia coli K12/fisiologia , Escherichia coli K12/patogenicidade , Microbioma Gastrointestinal , Infecções Oportunistas/microbiologia , Simbiose , Células CACO-2/citologia , Células CACO-2/microbiologia , Claudina-1/metabolismo , Proteínas do Citoesqueleto , Impedância Elétrica , Células Epiteliais/metabolismo , Expressão Gênica , Interações entre Hospedeiro e Microrganismos , Humanos , Mucosa Intestinal/metabolismo , Intestinos/microbiologia , Proteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/metabolismo , Ocludina/genética , Ocludina/metabolismo , Permeabilidade , RNA Mensageiro , Proteínas de Junções Íntimas/metabolismo , Junções Íntimas/metabolismo , Proteína da Zônula de Oclusão-1/metabolismo , beta-Defensinas/metabolismo
5.
Pol J Microbiol ; 68(1): 93-104, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31050257

RESUMO

Staphylococcus aureus is a common human and livestock opportunistic pathogen, and there is evidence of animal to human transmission. This paper aimed to recognize properties of the isolates from collections of human and livestock S. aureus strains and to estimate compatibility of results based on phenotypic tests, microarrays and the spa typing methods. The second goal was to study differences between human and animal isolates in terms of specificity of their hosts and the strain transmission among various hosts. Most strains showed multi-susceptible profiles and produced enzymes on a high level, and they were phenotypically and genetically similar. However, in contrast to the Polish bovine mastitis strains, the Slovakian strains were multi-resistant. In this research, the strains showed significant differences in terms of their phenotypic manifestations and the presence of hemolysins genes; however, other enzyme-encoding genes correlated to a higher extent with the microarrays results. Interestingly, there was a lack of enterotoxin genes in human Poultry-like protein A+ strains in comparison to other human strains. Our study showed that differences between virulence profiles of the human and animal strains correlated with their origin rather than their hosts, and any trait allowed clearly distinguishing between them based on the microarray results.Staphylococcus aureus is a common human and livestock opportunistic pathogen, and there is evidence of animal to human transmission. This paper aimed to recognize properties of the isolates from collections of human and livestock S. aureus strains and to estimate compatibility of results based on phenotypic tests, microarrays and the spa typing methods. The second goal was to study differences between human and animal isolates in terms of specificity of their hosts and the strain transmission among various hosts. Most strains showed multi-susceptible profiles and produced enzymes on a high level, and they were phenotypically and genetically similar. However, in contrast to the Polish bovine mastitis strains, the Slovakian strains were multi-resistant. In this research, the strains showed significant differences in terms of their phenotypic manifestations and the presence of hemolysins genes; however, other enzyme-encoding genes correlated to a higher extent with the microarrays results. Interestingly, there was a lack of enterotoxin genes in human Poultry-like protein A+ strains in comparison to other human strains. Our study showed that differences between virulence profiles of the human and animal strains correlated with their origin rather than their hosts, and any trait allowed clearly distinguishing between them based on the microarray results.


Assuntos
Reservatórios de Doenças/microbiologia , Mastite Bovina/microbiologia , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/microbiologia , Animais , Antibacterianos/farmacologia , Bovinos , Farmacorresistência Bacteriana Múltipla/genética , Proteínas Hemolisinas/genética , Humanos , Gado/microbiologia , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Infecções Oportunistas/microbiologia
6.
Arch. Soc. Esp. Oftalmol ; 94(5): 237-241, mayo 2019. ilus
Artigo em Espanhol | IBECS | ID: ibc-180829

RESUMO

Varón de 30 años de edad con leucemia mieloblástica aguda y síndrome mielodisplásico secundario que desarrolló una enfermedad injerto contra huésped. El paciente fue tratado con ruxolitinib, un inhibidor de la Janus quinasa. A los 3 meses de haber iniciado el tratamiento se produjo una necrosis retiniana por Aspergillus, sin respuesta al tratamiento. El tratamiento con inhibidores de la Janus quinasa favorecería un aumento en la incidencia de infecciones oportunistas. El uso de estos fármacos podría dar lugar a una menor eficacia de los tratamientos empleados


A 30 year-old man with acute myeloblastic leukaemia and secondary myelodysplastic syndrome developed graft-versus-host disease. The patient was treated with ruxolitinib. After being treated for 3 months with ruxolitinib, an inhibitor of Janus kinase, he developed Aspergillus retinal necrosis resistant to common treatment. Treatment with Janus kinase inhibitors may lead to an increased incidence of opportunistic infections. Janus kinase inhibitor administration may result in poor treatment efficacy


Assuntos
Humanos , Masculino , Adulto , Síndrome de Necrose Retiniana Aguda/microbiologia , Infecções Oportunistas/microbiologia , Aspergilose/complicações , Janus Quinases/antagonistas & inibidores , Síndromes Mielodisplásicas/tratamento farmacológico , Evolução Fatal
7.
Prev Vet Med ; 166: 78-85, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30935508

RESUMO

The objective of this study was to evaluate and compare different combinations of intervention strategies for contagious or opportunistic subclinical and clinical intramammary infections (IMI). We simulated two different Danish dairy cattle herds with ten different intervention strategies focusing on cow-specific treatment or culling, including three baseline strategies without subclinical interventions. In one herd, the main causative pathogen of IMI was Staphylococcus (S.) aureus. In the other herd, Streptococcus (St.) agalactiae was the main causative agent. For both herds, we investigated costs and effectiveness of all ten intervention strategies. Intervention strategies consisted of measures against clinical and subclinical IMI, with baselines given by purely clinical intervention strategies. Our results showed that strategies including subclinical interventions were more cost-effective than the respective baseline strategies. Increase in income and reduction of IMI cases came at the cost of increased antibiotic usage and an increased culling rate in relation to IMI. However, there were differences between the herds. In the St. agalactiae herd, the clinical intervention strategy did not seem to have a big impact on income and number of cases. However, intervention strategies which included cow-specific clinical interventions led to a higher income and lower number of cases in the S. aureus herd. The results show that intervention strategies including interventions against contagious or opportunistic clinical and subclinical IMI can be highly cost-effective, but should be herd-specific.


Assuntos
Controle de Doenças Transmissíveis/métodos , Indústria de Laticínios , Mastite Bovina/prevenção & controle , Infecções Estafilocócicas/veterinária , Infecções Estreptocócicas/veterinária , Animais , Infecções Assintomáticas/economia , Bovinos , Dinamarca , Feminino , Mastite Bovina/economia , Mastite Bovina/microbiologia , Infecções Oportunistas/economia , Infecções Oportunistas/microbiologia , Infecções Oportunistas/prevenção & controle , Infecções Oportunistas/veterinária , Infecções Estafilocócicas/economia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/fisiologia , Infecções Estreptocócicas/economia , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae/fisiologia
8.
J Mycol Med ; 29(2): 168-173, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30846319

RESUMO

BACKGROUND: Fungal infection with opportunistic fungi can cause a serious problem for immunocompromised persons such as organ-transplant recipients, cancer, and HIV/AIDS patients. Control of these organisms using natural products is an interesting strategy to avoid the use of heavy chemotherapy in patients. OBJECTIVE: This study aimed to use the extract of Forsskaolea tenacissima L. and Xanthium spinosum L. to suppress the growth of Candida albicans and Geotrichum candidum and to investigate their potential mode of action. MATERIALS AND METHODS: Different plant extracts were tested for their antifungal activity using disc diffusion method and their mode of action was explored using the scanning electron microscopy (SEM) and gas chromatography-mass spectrometry (GC-MS). RESULTS: The results showed that chloroform extract of X. spinosum was the most effective against G. candidum, inhibiting its growth at very low concentration (38µg/mL). Chloroform extract of F. tenacissima was the most effective against C. albicans, with a minimum inhibitory concentration of 39µg/mL. SEM demonstrated the fungitoxicity of the plant extracts against both pathogens. C. albicans treated with plant extract were invaginated and ruptured and the treated mycelia of G. candidum were distorted and squashed. GC-MS analysis showed that the chloroform extract of both plants had 13 different compounds. CONCLUSION: Due to these promising results, these extracts should be further investigated and tested on different strains of C. albicans and G. candidum towards validation of their efficacy as a natural drug.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Geotrichum/efeitos dos fármacos , Extratos Vegetais/farmacologia , Antifúngicos/química , Candida albicans/ultraestrutura , Candidíase/microbiologia , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Micélio/efeitos dos fármacos , Infecções Oportunistas/microbiologia , Extratos Vegetais/química , Folhas de Planta/química , Caules de Planta/química , Xanthium/química
9.
World J Microbiol Biotechnol ; 35(3): 39, 2019 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-30739255

RESUMO

The correct identification of different genera and bacterial species is essential, especially when these bacteria cause infections and appropriate therapies need to be chosen. Bacteria belonging to the Burkholderia cepacia complex are considered important opportunistic pathogens, causing different types of infections in immunocompromised, principally in patients with cystic fibrosis. Twenty-one isolates were obtained from different soil samples and identified by sequencing of 16S rRNA, 23S rRNA, recA gene, MLST and by VITEK 2 and MALDI-TOF MS systems. Then, statistical analyses were performed. VITEK 2 and MALDI-TOF MS systems showed different bacterial genera. Sequencing of the 16S rRNA, 23S rRNA gene and amplification of recA gene showed that all the isolates belong to the B. cepacia complex. Sequencing of the recA gene showed a predominance of B. cenocepacia. The PCR of the recA gene showed a high specificity when it is necessary to identify the bacteria belonging to the B. cepacia complex in comparison with 16S and 23S rRNA genes sequencing. MLST analyzes showed a diversity of STs, which have not yet been correlated to the species. Phenotypic identification was not suitable for the identification of these pathogens since in many cases different genera have been reported, including identification by using MALDI-TOF MS.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Complexo Burkholderia cepacia/classificação , Complexo Burkholderia cepacia/genética , Complexo Burkholderia cepacia/isolamento & purificação , Filogenia , Microbiologia do Solo , Proteínas de Bactérias/genética , Infecções por Burkholderia/microbiologia , Fibrose Cística/microbiologia , DNA Bacteriano/genética , Tipagem de Sequências Multilocus/métodos , Infecções Oportunistas/microbiologia , Fenótipo , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Recombinases Rec A/genética , Análise de Sequência de DNA , Especificidade da Espécie , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
10.
Exp Clin Transplant ; 17(Suppl 1): 216-219, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30777558

RESUMO

OBJECTIVES: The aim of this study was to assess initial and follow-up computed tomography findings of invasive pulmonary aspergillosis in solid-organ transplant recipients and to examine the most common computed tomography patterns during hospitalization. MATERIALS AND METHODS: From January 2011 to September 2016, the total number of solid-organ transplant patients at our institution was 784. These patients consisted of 550 kidney, 164 liver, and 67 heart transplant recipients. Of these, 15 patients had a proven diagnosis of invasive pulmonary aspergillosis according to clinical and radiologic features with culture evidence of aspergillosis from bronchoalveolar lavage or lung biopsy. Computed tomography examinations were performed at initial diagnosis and at follow-up for evaluation of treatment. Computed tomography patterns were retrospectively evaluated by 2 experienced radiologists. Configurations and types of the largest lesions in each of the 15 patients were evaluated, and changes to lesions during treatment were recorded. Invasive pulmonary aspergillosis patterns were categorized into 6 main groups: ground-glass opacity, nodules, irregular nodules, patchy consolidation, cavity, and tree-in-bud patterns. RESULTS: The most common patterns were ground-glass opacity and irregular nodules, which were observed in 12 of 15 patients (80%), followed by regular nodules (73%), patchy consolidation and cavity (26%), and tree-in-bud pattern (20%). Long-term follow-up computed tomography studies showed that the regular nodules, tree-in-bud patterns, and groundglass opacity areas gradually reduced by 50% in 4 weeks. However, patchy consolidations and irregular nodules showed less regression than the other lesions over the 4-week period. CONCLUSIONS: Irregular nodules and ground-glass opacity were the most common computed tomography patterns in our solid-organ transplant recipients. Computed tomography patterns without irregular nodules and patchy consolidations may be associated with better prognosis due to their relatively rapid healing.


Assuntos
Aspergilose Pulmonar Invasiva/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Tomografia Computadorizada Multidetectores , Nódulos Pulmonares Múltiplos/diagnóstico por imagem , Infecções Oportunistas/diagnóstico por imagem , Transplante de Órgãos/efeitos adversos , Feminino , Humanos , Hospedeiro Imunocomprometido , Imunossupressores/efeitos adversos , Aspergilose Pulmonar Invasiva/imunologia , Aspergilose Pulmonar Invasiva/microbiologia , Pulmão/imunologia , Pulmão/microbiologia , Masculino , Nódulos Pulmonares Múltiplos/imunologia , Nódulos Pulmonares Múltiplos/microbiologia , Infecções Oportunistas/imunologia , Infecções Oportunistas/microbiologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Resultado do Tratamento
11.
Khirurgiia (Mosk) ; (1): 101-104, 2019.
Artigo em Russo | MEDLINE | ID: mdl-30789617

RESUMO

A clinical case of successful combined use of NPWT-therapy and Reamberin infusion in the treatment of a non-healing (over 5 months) trophic ulcer of the lower limb in an elderly patient is presented. It was manifested that introduction of antioxidant/antihypoxant drug reamberin on the background of NPWT-therapy in patient with slow healing wounds has a positive effect on metabolic processes, resulting in more active and rapid cleansing of wound surface from opportunistic microflora by the 5th day of therapy. Absence of adverse effects to drug application allows to recommend its inclusion in the complex treatment scheme in patients with this pathology.


Assuntos
Antioxidantes/administração & dosagem , Úlcera da Perna/terapia , Meglumina/análogos & derivados , Tratamento de Ferimentos com Pressão Negativa , Succinatos/administração & dosagem , Idoso , Terapia Combinada , Humanos , Infusões Intravenosas , Úlcera da Perna/microbiologia , Úlcera da Perna/fisiopatologia , Meglumina/administração & dosagem , Infecções Oportunistas/microbiologia , Infecções Oportunistas/fisiopatologia , Infecções Oportunistas/terapia
12.
J Infect Chemother ; 25(5): 351-354, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30711257

RESUMO

BACKGROUND: Pneumocystis jirovecii pneumonia (PCP) is an opportunistic infection in patients on steroid therapy for connective tissue diseases. The standard agent for primary PCP prophylaxis is trimethoprim/sulfamethoxazole (TMP-SMX), although this agent can cause common adverse reactions, including myelosuppression and renal toxicity, that result in cessation. Aerosolized pentamidine and oral atovaquone are alternatives for PCP prophylaxis. The efficacies of atovaquone, pentamidine, and TMP-SMX to prevent PCP in patients with connective tissue diseases have never been compared. METHODS: Hospitalized patients with connective tissue diseases who started steroid therapy and PCP prophylaxis were enrolled. PCP prophylaxis regimens were oral TMP-SMX, aerosolized pentamidine, or oral atovaquone. Information was retrospectively collected from medical records about laboratory findings, duration of PCP prophylaxis, and reasons for terminating PCP prophylaxis. RESULTS: Ninety-six patients received PCP prophylaxis. All of them were initially treated with TMP-SMX, but this was replaced during the study period with pentamidine in 33 patients and with atovaquone in 7. Forty-one (43%) patients discontinued TMP-SMX because of adverse events, and 5 (15%) also discontinued pentamidine. None of the patients discontinued atovaquone. The most frequent causes of TMP-SMX and pentamidine cessation were cytopenia (N = 15) and asthma (N = 2). The rates of continuing treatment with TMP-SMX, pentamidine, and atovaquone at one year after starting PCP prophylaxis were 55.3%, 68.6%, and 100%, respectively (P = 0.01). None of the patients developed PCP. CONCLUSION: Although TMP-SMX for PCP prophylaxis had to be discontinued in 43% of patients with connective tissue diseases, pentamidine and atovaquone were well tolerated.


Assuntos
Antibioticoprofilaxia/métodos , Doenças do Tecido Conjuntivo/complicações , Infecções Oportunistas/prevenção & controle , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/prevenção & controle , Administração por Inalação , Administração Oral , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibioticoprofilaxia/efeitos adversos , Asma/induzido quimicamente , Asma/epidemiologia , Atovaquona/uso terapêutico , Quimioterapia Combinada/efeitos adversos , Quimioterapia Combinada/métodos , Feminino , Doenças Hematológicas/induzido quimicamente , Doenças Hematológicas/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Oportunistas/microbiologia , Pentamidina/uso terapêutico , Pneumonia por Pneumocystis/microbiologia , Estudos Retrospectivos , Resultado do Tratamento , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico , Adulto Jovem
13.
PLoS One ; 14(2): e0211989, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30802260

RESUMO

BACKGROUND: Transplant recipients are at risk of pulmonary nocardiosis, a life-threatening opportunistic infection caused by Nocardia species. Given the limitations of conventional diagnostic techniques (i.e., microscopy and culture), a polymerase chain reaction (PCR)-based assay was developed to detect Nocardia spp. on clinical samples. While this test is increasingly being used by transplant physicians, its performance characteristics are not well documented. We evaluated the performance characteristics of this test on bronchoalveolar lavage (BAL) fluid samples from lung transplant recipients (LTRs). METHODS: We prospectively included all BAL samples from LTRs undergoing bronchoscopy at our institution between December 2016 and June 2017 (either surveillance or clinically-indicated bronchoscopies). Presence of microbial pathogens was assessed using techniques available locally (including microscopy and 10-day culture for Nocardia). BAL samples were also sent to the French Nocardiosis Observatory (Lyon, France) for the Nocardia PCR-based assay. Transplant physicians and patients were blinded to the Nocardia PCR results. RESULTS: We included 29 BAL samples from 21 patients (18 surveillance and 11 clinically-indicated bronchoscopies). Nocardiosis was not diagnosed in any of these patients by conventional techniques. However, Nocardia PCR was positive in five BAL samples from five of the patients (24%, 95% confidence interval: 11-45%); four were asymptomatic and undergoing surveillance bronchoscopy, and one was symptomatic and was later diagnosed with influenza virus infection. None of the five PCR-positive patients died or were diagnosed with nocardiosis during the median follow-up of 21 months after the index bronchoscopy (range: 20-23 months). CONCLUSIONS: In this prospective study, Nocardia PCR was positive on BAL fluid from one fourth of the LTRs. Nocardia PCR-based assays should be used with caution on respiratory samples from LTRs because of the possible detection of airway colonization using this technique. Larger studies are required to determine the usefulness of the Nocardia PCR-based assay in transplant recipients.


Assuntos
Transplante de Pulmão/efeitos adversos , Nocardiose/diagnóstico , Nocardia/isolamento & purificação , Infecções Oportunistas/microbiologia , Adulto , Idoso , Bélgica , Líquido da Lavagem Broncoalveolar/microbiologia , Feminino , Humanos , Pessoa de Meia-Idade , Nocardia/genética , Projetos Piloto , Reação em Cadeia da Polimerase , Estudos Prospectivos , RNA Ribossômico 16S/genética , RNA Viral/genética , Sensibilidade e Especificidade
15.
Chemosphere ; 219: 971-980, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30682762

RESUMO

Drinking water distribution systems (DWDS) may be a "Trojan Horse" for some waterborne diseases caused by opportunistic pathogens (OPs). In this study, two simulated DWDS inoculated with groundwater were treated with chlorine (Cl2) and ultraviolet/chlorine (UV/Cl2) respectively to compare their effects on the OPs distributed in four different phases (bulk water, biofilms, corrosion products, and loose deposits) of DWDS. 16S rRNA genes sequencing and qPCR were used to profile microbial community and quantify target genes of OPs, respectively. Results showed that UV/Cl2 was more effective than single Cl2 to control the regrowth of OPs in the water with the same residual chlorine concentration. However, the OPs inhabiting the biofilms, corrosion products, and loose deposits seemed to be tolerant to UV/Cl2 and Cl2, demonstrating that OPs residing in these phases were resistant to the disinfection processes. Some significant microbial correlations between OPs and Acanthamoeba were found by Spearman correlative analysis (p < 0.05), demonstrating that the ecological interactions may exist in the DWDS. 16S rRNA genes sequencing of water samples revealed a significant different microbial community structure between UV/Cl2 and Cl2. This study may give some implications for controlling the OPs in the DWDS disinfected with UV/Cl2.


Assuntos
Cloro , Desinfecção/métodos , Infecções Oportunistas/microbiologia , Raios Ultravioleta , Purificação da Água/métodos , Biofilmes/efeitos dos fármacos , Desinfetantes/farmacologia , Água Potável , Microbiota , RNA Ribossômico 16S/análise
17.
Nat Commun ; 10(1): 27, 2019 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-30604752

RESUMO

Bacterial persisters are phenotypic variants that tolerate exposure to lethal antibiotics. These dormant cells are responsible for chronic and recurrent infections. Multiple mechanisms have been linked to persister formation. Here, we report that a complex, consisting of an extracellular poly(dC) and its membrane-associated binding protein RmlB, appears to be associated with persistence of the opportunistic pathogen Pseudomonas aeruginosa. Environmental stimuli triggers a switch in the complex physiological state (from poly(dC)/RmlB to P-poly(dC)/RmlB or RmlB). In response to the switch, bacteria decrease proton motive force and intracellular ATP levels, forming dormant cells. This alteration in complex status is linked to a (p)ppGpp-controlled signaling pathway that includes inorganic polyphosphate, Lon protease, exonuclease VII (XseA/XseB), and the type III secretion system. The persistence might be also an adaptive response to the lethal action of the dTDP-L-rhamnose pathway shutdown, which occurs due to switching of poly(dC)/RmlB.


Assuntos
Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/fisiologia , Hidroliases/metabolismo , Poli C/metabolismo , Pseudomonas aeruginosa/fisiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Exodesoxirribonucleases/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Infecções Oportunistas/tratamento farmacológico , Infecções Oportunistas/microbiologia , Fosforilação , Protease La/metabolismo , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Ramnose/metabolismo , Sistemas de Secreção Tipo III/metabolismo
19.
Acta Parasitol ; 64(1): 103-111, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30644064

RESUMO

BACKGROUND : Microsporidia may cause infection in both immunocompromised and immunocompetent populations. The best strategy to control microsporidiosis is obtaining thorough knowledge of its outbreak and pathogenicity. PURPOSE : Because of the lack of precise estimation of microsporidia prevalence among Iranian children with cancer, the current study aimed at evaluating the rate of intestinal microsporidia in children undergoing chemotherapy. METHODS:  Patients with cancer undergoing chemotherapy in a children's hospital in Northwestern Iran were studied; 132 stool samples were collected and stained by the Weber and Ryan-blue modified trichrome staining techniques. The extracted DNA samples were evaluated by the nested polymerase chain reaction (PCR) method. All positive isolates were sequenced for genotyping and phylogenetic analysis. RESULTS: A total of 17 (12.8%) samples were microscopically positive for microsporidia infection, whereas only 14 (10.6%) cases were positive based on nested PCR results. In the positive samples detected with nested PCR, the frequency of Enterocytozoon bieneusi and Encephalitozoon intestinalis infections was 71.4% (n = 10) and 28.6% (n = 4), respectively. After sequencing and phylogenetic analysis, the genotype of E. bieneusi was type D and the sequences of the isolated species were similar to those of the registered ones. CONCLUSION: E. bieneusi is a major contributor to microsporidiosis in young immunocompromised patients in Iran. Microsporidia species are well-detected when confirmatory techniques such as molecular methods are in agreement with staining. So, to ensure this, a suggestion has been made to introduce a certain diagnostic test for microsporidiosis.


Assuntos
Encephalitozoon/classificação , Encephalitozoon/isolamento & purificação , Encefalitozoonose/epidemiologia , Encefalitozoonose/microbiologia , Neoplasias/complicações , Infecções Oportunistas/epidemiologia , Infecções Oportunistas/microbiologia , Criança , DNA Fúngico/química , DNA Fúngico/isolamento & purificação , Encephalitozoon/genética , Encefalitozoonose/patologia , Fezes/microbiologia , Genótipo , Humanos , Irã (Geográfico) , Infecções Oportunistas/patologia , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Análise de Sequência de DNA
20.
PLoS One ; 14(1): e0210218, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30633757

RESUMO

Enterococcus faecalis is a major opportunistic pathogen that readily forms protective biofilms leading to chronic infections. Biofilms protect bacteria from detergent solutions, antimicrobial agents, environmental stress, and effectively make bacteria 10 to 1000-fold more resistant to antibiotic treatment. Extracellular proteins and polysaccharides are primary components of biofilms and play a key role in cell survival, microbial persistence, cellular interaction, and maturation of E. faecalis biofilms. Degradation of biofilm components by mammalian proteases is an effective antibiofilm strategy because proteases are known to degrade bacterial proteins leading to bacterial cell lysis and growth inhibition. Here, we show that human matrix metalloprotease-1 inhibits and disrupts E. faecalis biofilms. MMPs are cell-secreted zinc- and calcium-dependent proteases that degrade and regulate various structural components of the extracellular matrix. Human MMP1 is known to degrade type-1 collagen and can also cleave a wide range of substrates. We found that recombinant human MMP1 significantly inhibited and disrupted biofilms of vancomycin sensitive and vancomycin resistant E. faecalis strains. The mechanism of antibiofilm activity is speculated to be linked with bacterial growth inhibition and degradation of biofilm matrix proteins by MMP1. These findings suggest that human MMP1 can potentially be used as a potent antibiofilm agent against E. faecalis biofilms.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Metaloproteinase 1 da Matriz/farmacologia , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Enterococcus faecalis/fisiologia , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Metaloproteinase 1 da Matriz/isolamento & purificação , Metaloproteinase 1 da Matriz/uso terapêutico , Testes de Sensibilidade Microbiana , Infecções Oportunistas/tratamento farmacológico , Infecções Oportunistas/microbiologia , Proteólise/efeitos dos fármacos , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Vancomicina/farmacologia
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