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1.
J Med Microbiol ; 69(2): 228-232, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31922949

RESUMO

Introduction. Rapid and reliable detection of carbapenemase-producing Enterobacterales (CPE) from surveillance cultures is critical in supporting a good infection control programme. We implemented a new algorithm for CPE detection incorporating the NG Test CARBA 5 in January 2019.Aim. Our goals were to compare turnaround time (TAT), costs and staff requirements between the old and new algorithm, and to evaluate the performance of the CARBA 5 test directly on colonies grown on CARBA Smart agar.Methodology. We analysed and compared the TAT of CPE surveillance cultures processed using the old and new CPE screening algorithm. The total actual reagent costs and staff requirements for the new CPE algorithm were compared with the estimated costs and staff requirements of the old CPE algorithm.Results. Of 197 isolates included in the evaluation of the new algorithm, 64 were positive for carbapenemases by both CARBA 5 and Xpert Carba-R assay. Of the 133 that were negative, two were found to harbour NDM and IMI genotypes. Significant improvements in TAT were achieved with 88.7 % of cultures with CPE, reported on the same day as growth was observed on CARBA Smart agar compared to none in the old algorithm. The new algorithm incurred lower costs and, based on our workload, the new algorithm is estimated to save 28.9 man-hours annually.Conclusion. CARBA 5 performs well on colonies growing on CARBA Smart agar and significant improvements in TAT can be achieved without incurring additional costs or staff requirements.


Assuntos
Proteínas de Bactérias/metabolismo , Técnicas de Laboratório Clínico/métodos , Contagem de Colônia Microbiana/métodos , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/crescimento & desenvolvimento , Enterobacteriaceae/isolamento & purificação , Ensaios Enzimáticos/métodos , Algoritmos , Proteínas de Bactérias/genética , Técnicas de Laboratório Clínico/economia , Contagem de Colônia Microbiana/economia , Enterobacteriaceae/enzimologia , Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/diagnóstico , Ensaios Enzimáticos/economia , Humanos , Sensibilidade e Especificidade , beta-Lactamases/genética , beta-Lactamases/metabolismo
2.
Food Microbiol ; 87: 103381, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948622

RESUMO

Indirect impedance has been used for the detection and enumeration of bacteria, however there is limited data regarding the ability of the method to measure growth and inhibition of microorganisms in food in response to preservatives. The aim of this study was to evaluate the suitability of the technique to determine maximum growth rates of Listeria innocua (used as a surrogate for Listeria monocytogenes) in complex food matrices to which multiple preservative factors had been applied and assess the suitability of the data for use in predictive microbiology. Growth of L. innocua in laboratory medium (BHI broth) and two food matrices (zucchini purée and béarnaise sauce) under varying conditions of pH (5 & 5.3), water activity (0.93, 0.96 & 0.98) and acetic and propionic acid concentration (0, 1 & 2 mM) was monitored by the conductimetric Rapid Automated Bacterial Impedance Technology (R.A.B.I.T) system by means of CO2 emission for up to 120 h. Growth rates of L. innocua were determined for several conditions across the three test matrices and a good correlation between detection times and initial inoculum level was observed in most cases (R2 ≥ 0.82). However, growth of L. innocua was not detected in a large number of conditions and comparison of growth rates determined by indirect impedance to those determined by plate counts indicated that in general, the R.A.B.I.T. system under-estimated growth. This study demonstrates that there are limitations associated with the technology, and as a result the system may be unsuitable for measuring microbial growth rates in complex food matrices under the environmental conditions tested and within the time duration of the study.


Assuntos
Contagem de Colônia Microbiana/métodos , Técnicas Eletroquímicas/métodos , Microbiologia de Alimentos/métodos , Listeria/química , Listeria/crescimento & desenvolvimento , Dióxido de Carbono/análise , Dióxido de Carbono/metabolismo , Impedância Elétrica , Contaminação de Alimentos/análise , Concentração de Íons de Hidrogênio , Listeria/metabolismo , Listeria monocytogenes/química , Listeria monocytogenes/crescimento & desenvolvimento , Listeria monocytogenes/metabolismo , Água/análise , Água/metabolismo
3.
Acta Med Port ; 32(9): 568-575, 2019 Sep 02.
Artigo em Português | MEDLINE | ID: mdl-31493359

RESUMO

INTRODUCTION: Urinary tract infections in the community setting are quite common. It is necessary to be aware of antibiotic susceptibility patterns in order to provide rational empirical therapy. The aim of this study is to determine the frequency and antimicrobial susceptibility of the strains responsible for urinary tract infections in primary health care, in the district of Coimbra, Portugal. MATERIAL AND METHODS: In this observational and cross-sectional study, we analyzed 7134 positive urine cultures of outpatient laboratories in the district of Coimbra, over one year. In most cases, a positive culture was defined by a threshold of 105 colony-forming units per milliliter and was conducted by the automated system VITEK® 2, by bioMérieux. We used descriptive and inferential statistics to determine the prevalence and antimicrobial susceptibility of bacteria and to ascertain whether there were differences associated with sex and age. RESULTS: From the total of positive cultures, 83.4% pertained to females and 41.0% to individuals over 75 years old. Escherichia coli was the most frequent strain (63.9%), although its prevalence was lower (p < 0.001) in males and individuals over 75 years old. Its susceptibility to fosfomycin and nitrofurantoin was higher than 95% and with ciprofloxacin and trimethoprim/sulfamethoxazole it was lower than 80%. Resistances were more frequent (p < 0.001) in males and in the elderly. DISCUSSION: Escherichia coli was the most frequent strain, revealing less resistance to fosfomycin and nitrofurantoin. Antimicrobial susceptibility was lower in the elderly and in males, populations in whom empirical therapy may be less successful. CONCLUSION: In order to improve clinical results, we recommend periodic surveillance of antimicrobial susceptibility, which could enable the provision of efficient information to clinicians, namely those who prescribe empirically for such infections, as well as standardization of identification methods of bacterial strains diagnosis and of the antibiotic kits to be tested.


Assuntos
Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Infecções Urinárias/tratamento farmacológico , Fatores Etários , Anti-Infecciosos Urinários/farmacologia , Técnicas Bacteriológicas/métodos , Contagem de Colônia Microbiana/métodos , Estudos Transversais , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Feminino , Humanos , Masculino , Portugal , Fatores Sexuais , Infecções Urinárias/microbiologia
4.
Int J Food Microbiol ; 305: 108245, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31295678

RESUMO

This study aimed to evaluate the performance of Hicrome Bacillus™ agar for isolation and rapid identification of the aerobic spore-forming bacteria most frequently found in honey samples. A collection of 197 bacterial isolates of Bacillus, Brevibacillus, Lysinibacillus, Paenibacillus, and Rummeliibacillus belonging to different species that have been reported in honey were screened for their abilities to grow and for their colony colors and medium appearance in HiCrome Bacillus agar. Also, 21 strains from culture collections were used for comparison and quality controls. A flowchart utilizing a combination of colony and media characteristics in the chromogenic medium and a set of simple biochemical and morphological tests were elaborated for quick presumptive identification. A procedure for direct isolation from honey samples was developed. In conclusion, HiCrome Bacillus agar in combination with simple microbiological tests was highly useful for rapid and reliable identification of most Bacillus, Brevibacillus, Lysinibacillus and Paenibacillus species commonly found in honey samples facilitating isolation from polymicrobial honey.


Assuntos
Bacillaceae/isolamento & purificação , Bacillus/isolamento & purificação , Contagem de Colônia Microbiana/métodos , Mel/microbiologia , Bacillaceae/classificação , Bacillaceae/genética , Bacillaceae/crescimento & desenvolvimento , Bacillus/classificação , Bacillus/genética , Bacillus/crescimento & desenvolvimento , Contagem de Colônia Microbiana/instrumentação , Microbiologia de Alimentos
5.
BMC Infect Dis ; 19(1): 646, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324234

RESUMO

BACKGROUND: The aim of this study was to establish a set of assessment methods suitable for evaluating the complex indoor environment of hospital wards and to ascertain the composition of bacteria and microbial ecology of hospital wards. METHODS: Colony-forming units (CFUs), PM2.5 detection, real-time PCR, and adenosine triphosphate (ATP) bioluminescence assay were employed to evaluate the complexity of indoor air in 18 wards of nine departments in a hospital and two student dormitories in a university. Subsequently, the microbial samples were quantified and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). RESULTS: Although the studied indices were relatively independent, the PM2.5 content was correlated with bacterial CFUs determined by passive sedimentation method, bacterial and fungal counts measured by real-time PCR, and ATP bioluminescence assay. The composition of microorganisms in the air of hospital wards differed from that in the air of student dormitories. The dominant genera in hospital wards were Staphylococcus (39.4%), Micrococcus (21.9%), Corynebacterium (11.7%), Kocuria (4.4%), Bacillus (2.9%), Streptococcus (1.6%), Moraxella (1.6%), and Enterococcus (1.3%), and the microbial ecology differed between Respiration Dept. III and other hospital departments. Additionally, 11.1 and 27.3% of bacteria in hospital wards and student dormitories were not identified, respectively. CONCLUSIONS: Assessment of environmental quality of hospital wards should be based on comprehensive analysis with multiple indicators. There may be imbalances in the microbial diversity in the hospital wards, therefore, monitoring of the environmental quality of hospitals is important in the prevention of nosocomial infections.


Assuntos
Microbiologia do Ar , Poluição do Ar em Ambientes Fechados/análise , Hospitais , Medições Luminescentes/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Trifosfato de Adenosina/análise , Carga Bacteriana/métodos , China , Contagem de Colônia Microbiana/métodos , Humanos , Material Particulado/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Staphylococcus
6.
J Perinat Med ; 47(7): 741-749, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31339859

RESUMO

Background Bisphenol-A (BPA) is a widespread pollutant whose effects on pregnant women are poorly understood. Therefore, we investigated the effects of BPA on basal and bacteria-stimulated production of proinflammatory cytokines [interleukin (IL)-1ß, tumor necrosis factor-α (TNF-α) and IL-6], anti-inflammatory mediators [soluble glycoprotein 130 (sgp) 130, heme oxidase-1 (HO-1) and IL-10] and biomarkers for neurodevelopment [brain-derived neurotrophic factor (BDNF)], and oxidative stress [8-isoprostane (8-IsoP)] by the placenta. Methods Placental explant cultures were treated with BPA (0-10,000 nM) in the presence or absence of 107 colony-forming unit (CFU)/mL heat-killed Escherichia coli for 24 h. Biomarker concentrations in conditioned medium were quantified by the enzyme-linked immunosorbent assay (ELISA). Results Under basal conditions, IL-1ß and IL-6 production was enhanced by BPA in a dose-dependent manner. Sgp130, a soluble receptor that reduces IL-6 bioactivity, was suppressed by BPA at 1000-10,000 nM. BPA also enhanced BDNF production at 1000 and 10,000 nM, and 8-IsoP expression at 10 and 100 nM. For bacteria-treated cultures, BPA increased IL-6 production at 100 nM and reduced sgp130 at 1000 nM but had no effect on IL-1ß, TNF-α, BDNF, HO-1, 8-IsoP or IL-10 production. Conclusion BPA may increase placental inflammation by promoting IL-1ß and IL-6 but inhibiting sgp130. It may also disrupt oxidative balance and neurodevelopment by increasing 8-IsoP and BDNF production.


Assuntos
Compostos Benzidrílicos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Citocinas , Escherichia coli/crescimento & desenvolvimento , Inflamação , Fenóis , Placenta , Poluentes Ocupacionais do Ar/efeitos adversos , Poluentes Ocupacionais do Ar/metabolismo , Compostos Benzidrílicos/efeitos adversos , Compostos Benzidrílicos/metabolismo , Biomarcadores/metabolismo , Contagem de Colônia Microbiana/métodos , Citocinas/classificação , Citocinas/metabolismo , Estrogênios não Esteroides/efeitos adversos , Estrogênios não Esteroides/metabolismo , Feminino , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fenóis/efeitos adversos , Fenóis/metabolismo , Placenta/efeitos dos fármacos , Placenta/imunologia , Placenta/metabolismo , Gravidez
7.
Methods Mol Biol ; 1997: 319-345, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31119632

RESUMO

Neisseria gonorrhoeae (Gc) infection of its obligate human host results in a robust neutrophil-driven immune response. Despite neutrophils' intrinsic ability to neutralize microbes, Gc can survive in the presence of neutrophils. To interrogate how this pathogen evades killing by neutrophils, we employ an ex vivo model of Gc infection with Interleukin-8-primed and adhered primary human neutrophils. This chapter will describe how primary human neutrophils are purified from venous blood, how Gc is prepared for infection, how to assess Gc survival in the presence of human neutrophils by enumeration of colony forming units, and how to determine Gc internalization by human neutrophils using an immunofluorescence-based approach.


Assuntos
Neisseria gonorrhoeae/imunologia , Neutrófilos/imunologia , Cultura Primária de Células/métodos , Células Cultivadas , Contagem de Colônia Microbiana/métodos , Humanos , Evasão da Resposta Imune , Viabilidade Microbiana/imunologia , Neisseria gonorrhoeae/crescimento & desenvolvimento , Fagocitose
8.
ISME J ; 13(9): 2162-2172, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31053828

RESUMO

Relationships between microbial genes and performance are often evaluated in the laboratory in pure cultures, with little validation in nature. Here, we show that genomic traits related to laboratory measurements of maximum growth potential failed to predict the growth rates of bacteria in unamended soil, but successfully predicted growth responses to resource pulses: growth increased with 16S rRNA gene copy number and declined with genome size after substrate addition to soils, responses that were repeated in four different ecosystems. Genome size best predicted growth rate in response to addition of glucose alone; adding ammonium with glucose weakened the relationship, and the relationship was absent in nutrient-replete pure cultures, consistent with the idea that reduced genome size is a mechanism of nutrient conservation. Our findings demonstrate that genomic traits of soil bacteria can map to their ecological performance in nature, but the mapping is poor under native soil conditions, where genomic traits related to stress tolerance may prove more predictive. These results remind that phenotype depends on environmental context, underscoring the importance of verifying proposed schemes of trait-based strategies through direct measurement of performance in nature, an important and currently missing foundation for translating microbial processes from genes to ecosystems.


Assuntos
Bactérias/crescimento & desenvolvimento , Bactérias/genética , Contagem de Colônia Microbiana/métodos , Microbiologia do Solo , Bactérias/classificação , Bactérias/metabolismo , Meios de Cultura/metabolismo , DNA Bacteriano/genética , Ecossistema , Tamanho do Genoma , Genômica , Fenótipo , RNA Ribossômico 16S/genética , Solo/química
9.
BMC Microbiol ; 19(1): 65, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30898089

RESUMO

BACKGROUND: Quantification of viable microorganisms is an important step in microbiological research as well as in microbial product formulation to develop biological control products or probiotics. Often, the efficiency of the resulting product is dependent on the microbial cell density and their viability, which may decrease over time. Commonly, the number of viable cells is determined by serial dilution and plating techniques or flow cytometry. In 2017, we developed a mathematical model for isothermal microcalorimetry (IMC) data analysis and showed that the new method allows for a more rapid quantification of viable fresh and freeze-dried anaerobic Lactobacillus reuteri cells than traditional viable count methods. RESULTS: This study developed the new method further by applying it to well-known aerophilic plant-beneficial microbial species (Pseudomonas brassicacearum, Bacillus amyloliquefaciens subsp. plantarum and Clonostachys rosea) used in biological control products. We utilized IMC to quantify viable cells in microbial pure cultures as well as when coated onto wheat seeds. The results from this study confirmed that thermal viable count methods are more rapid and sensitive than traditional viable count techniques. Most interestingly, a thermal viable count method was able to quantify microbes coated on seeds despite the presence of the natural microbiota of the seeds. Our results also showed that, in contrast to plating techniques for which clustered cells skew the results, IMC does not require single cells for accurate viable counts. CONCLUSIONS: Thermal viable count methods are novel methods for the rapid quantification of divergent bacterial and fungal species and enhance the speed, sensitivity, and accuracy of routine viable counts of pure cultures and controlled microbiomes such as plant seed coatings.


Assuntos
Bactérias/isolamento & purificação , Calorimetria/métodos , Contagem de Colônia Microbiana/métodos , Viabilidade Microbiana , Modelos Teóricos , Temperatura Ambiente , Anaerobiose , Citometria de Fluxo , Congelamento , Lactobacillus reuteri/isolamento & purificação , Reprodutibilidade dos Testes , Sementes/microbiologia , Sensibilidade e Especificidade
10.
Vet Microbiol ; 230: 265-272, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30827399

RESUMO

Enumeration of Mycobacterium avium subsp. paratuberculosis (MAP) from clinical samples or from inoculum suspensions for challenge studies is an essential pre-requisite for paratuberculosis research. However, MAP organisms are slow and challenging to grow in vitro, with a strong tendency to clump. Standard bacteriological methods are not well suited to enumerate MAP. Enumeration can be achieved by culture-based methods, direct microscopic counts, turbidimetry, pelleted weights and quantitative PCR. There is an unresolvable discrepancy between culture-based methods, enumerating cultivable MAP organisms, and other methods enumerating total MAP organisms irrespective of viability, hence these methods are not directly comparable. However, they are complementary and should be used in parallel when accuracy is required. We review currently available methods, their principles, limitations and equivalence between methods.


Assuntos
Técnicas Bacteriológicas/métodos , Contagem de Colônia Microbiana/métodos , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Mycobacterium avium subsp. paratuberculosis/crescimento & desenvolvimento , Paratuberculose/microbiologia , Reação em Cadeia da Polimerase/métodos
11.
J AOAC Int ; 102(4): 1138-1144, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30651164

RESUMO

Background: The MC-Media Pad™ Yeast and Mold (YM) is a ready-to use culture device that combines a test pad coated with medium and water-absorption polymers that is designed for the rapid quantification of yeast and mold in food products. Objective: The MC-Media Pad YM was compared with the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) for the enumeration of yeast and mold in frozen orange juice concentrate. Methods: The candidate method was evaluated using a paired study design in a multilaboratory collaborative study following the current AOAC Validation Guidelines. Three target contamination levels (low, 10-100 CFU/g; medium, 100-1000 CFU/g; and high 1000-10 000 CFU/g) and an uninoculated control level (0 CFU/g) were evaluated. MC-Media Pad YM devices were enumerated after 48 and 72 h of incubation. Results: Plate count obtained by both methods were log-transformed and the difference of means (including 95% confidence intervals), repeatability SD, and SD were determined for each contamination level. Conclusions: No statistical difference was observed between the MC-Media Pad YM (for both 48 and 72 h) and the FDA BAM for each contamination level. Highlights: The new method offers a convenient alternative to the reference method (FDA BAM) for detection of yeast and mold contamination in food products, yielding reliable and comparable results in 48 h compared to 5 days for the reference method.


Assuntos
Aspergillus fumigatus/isolamento & purificação , Contagem de Colônia Microbiana/métodos , Contaminação de Alimentos/análise , Microbiologia de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Leveduras/isolamento & purificação , Citrus sinensis/microbiologia
12.
J Microbiol Methods ; 157: 93-99, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30629964

RESUMO

With increasing antibiotic resistance observed amongst clinical isolates of Neisseria gonorrhoeae, the second most prevalent sexually transmitted bacterial disease in the United States, there is still a need for antimicrobial susceptibility testing (AST). The current method recommended by the Clinical and Laboratory Standards Institute is agar dilution. In this study, we show that a commercially available version of Fastidious Broth is capable of supporting N. gonorrhoeae in the evaluation of minimum inhibitory concentrations of 4 antibiotics (ceftriaxone, azithromycin, ciprofloxacin, and tetracycline), when comparing the agar dilution (AD) versus microbroth dilution (MBD) method and the susceptibilities obtained for 32 N. gonorrhoeae isolates. Herein, 3 out of the 4 antibiotics tested showed 94% or greater essential agreement (EA) and 91% or greater categorical agreement (CA) respectively, when comparing the MBD versus AD methods.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/fisiologia , Gonorreia/tratamento farmacológico , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/crescimento & desenvolvimento , Azitromicina/farmacologia , Ceftriaxona/farmacologia , Ciprofloxacino/farmacologia , Contagem de Colônia Microbiana/métodos , Meios de Cultura/química , Humanos , Testes de Sensibilidade Microbiana/métodos , Neisseria gonorrhoeae/isolamento & purificação , Tetraciclina/farmacologia
13.
mSphere ; 4(1)2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30602526

RESUMO

Many microbiological assays include colonies that produce a luminescent or fluorescent (here generalized as "luminescent") signal, often in the form of luminescent halos around the colonies. These signals are used as reporters for a trait of interest; therefore, exact measurements of the luminescence are often desired. However, there is currently a lack of high-throughput methods for analyzing these assays, as common automatic image analysis tools are unsuitable for identifying these halos in the presence of the inherent biological noise. In this work, we have developed CFQuant-automatic, high-throughput software for the analysis of images from colony luminescence assays. CFQuant overcomes the problems of automatic identification by relying on the luminescence halo's expected shape and provides measurements of several features of the colonies and halos. We examined the performance of CFQuant using one such colony luminescence assay, where we achieved a high correlation (R = 0.85) between the measurements of CFQuant and known protein expression levels. This demonstrates CFQuant's potential as a fast and reliable tool for analysis of colony luminescence assays.IMPORTANCE Luminescent markers are widely used as reporters for various biologically interesting traits. In colony luminescence assays, the levels of luminescence around each colony can be used to compare the levels of traits of interest for different strains, treatments, etc., using quantitative measurements of the luminescence. However, automatic methods of obtaining this data are underdeveloped, making this a laborious manual process, especially in analyzing large numbers of colonies. The significance of this work is in developing an automatic, high-throughput tool for quantitative analysis of colony luminescence assays, which will allow fast collection of qualitative data from these assays and thus increase their overall usability.


Assuntos
Ensaios de Triagem em Larga Escala/instrumentação , Processamento de Imagem Assistida por Computador , Luminescência , Software , Contagem de Colônia Microbiana/métodos
14.
Methods Mol Biol ; 1880: 679-690, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30610731

RESUMO

Bacteria that escape from membrane-enclosed vacuoles to the cytosol of cells are targeted by autophagy, which recognizes and captures bacteria into autophagosomes wherein their proliferation is restricted. Here we discuss two means by which antibacterial autophagy is assessed: (1) the visualization and enumeration of autophagy protein recruitment to the vicinity of cytosolic bacteria by means of immunofluorescence microscopy and (2) the measurement of autophagy-dependent restriction of bacterial proliferation by means of colony-forming unit assay.


Assuntos
Autofagossomos/imunologia , Autofagia/imunologia , Bioensaio/métodos , Interações Hospedeiro-Patógeno/imunologia , Autofagossomos/microbiologia , Bioensaio/instrumentação , Técnicas de Cultura de Células/instrumentação , Técnicas de Cultura de Células/métodos , Contagem de Colônia Microbiana/instrumentação , Contagem de Colônia Microbiana/métodos , Células HeLa , Humanos , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Interferência de RNA , Salmonella typhimurium/genética , Salmonella typhimurium/imunologia , Salmonella typhimurium/isolamento & purificação , Transformação Bacteriana , Vacúolos/imunologia , Vacúolos/microbiologia
15.
J Matern Fetal Neonatal Med ; 32(16): 2702-2710, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29478370

RESUMO

BACKGROUND: The majority of early preterm births are associated with intrauterine infections, which are thought to occur when microbes traffic into the uterus from the lower genital tract and seed the placenta. Bacterial vaginosis (BV) is associated with heterogeneous bacterial communities in the vagina and is linked to preterm birth. The extent to which trafficking into the uterus of normal and BV-associated vaginal bacteria occurs is unknown. The study objective was to characterize in parallel the distribution and quantities of bacteria in the vagina, uterus, and placental compartments. METHODS: Pregnant women at term (≥37 weeks) presenting for delivery were recruited prospectively. Swabs were collected in parallel from the vagina, chorioamnion. Choriodecidual swabs were collected if a cesarean section was performed. Samples were analyzed by culture, broad-range 16S rRNA gene PCR, and bacterial species-specific quantitative PCR (qPCR) for DNA from Lactobacillus and a panel of BV-associated bacteria. Results were correlated with placental histopathology. RESULTS: Of the 23 women enrolled, 15 were delivered by cesarean section (N = 10 without labor; N = 5 in labor) and eight were delivered vaginally. BV was diagnosed in two women not in labor. Placental histopathology identified chorioamnionitis or funisitis in six cases [1/10 (10%) not in labor; 5/13 (38%) in labor]. Among non-laboring women, broad-range 16S qPCR detected bacteria in the chorioamnion and the choriodecidua (4/10; 40%). Among laboring women, Lactobacillus species were frequently detected in the chorioamnion by qPCR (4/13; 31%). In one case, mild chorioamnionitis was associated with qPCR detection of similar microbes in the chorioamnion and vagina (e.g. Leptotrichia/Sneathia, Megasphaera), along a quantitative gradient. CONCLUSIONS: Microbial trafficking of lactobacilli and fastidious bacteria into the chorioamniotic membranes and choriodecidua occurs at term in normal pregnancies. In one case, we demonstrated a quantitative gradient between multiple bacterial species in the lower genital tract and placenta. Not all bacterial colonization is associated with placental inflammation and clinical sequelae. Further studies of the role of placental colonization with Lactobacillus in normal pregnancy and fastidious bacteria in chorioamnionitis may improve prevention and treatment approaches for preterm labor.


Assuntos
Corioamnionite/microbiologia , DNA Bacteriano/isolamento & purificação , Lactobacillus/isolamento & purificação , Trabalho de Parto Prematuro/microbiologia , Vagina/microbiologia , Vaginose Bacteriana/microbiologia , Adulto , Contagem de Colônia Microbiana/métodos , DNA Bacteriano/genética , Feminino , Humanos , Lactobacillus/genética , Gravidez , RNA Ribossômico 16S/isolamento & purificação , Útero/microbiologia , Adulto Jovem
16.
Food Chem ; 270: 445-451, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30174070

RESUMO

Rapid and efficient detection of pathogenic bacteria from food is critical to prevent epidemic food poisoning. However, the isolation of pathogenic bacteria from spoiled food is hampered by the lack of proper cell cultivation and/or isolation methods. Most of currently used methods suffer from complex, time-consuming culturing steps, low scalability, and high operation cost. Herein, we developed an alternative approach for the isolation of pathogenic bacteria directly from food using a surface-modified, highly porous sponge via initiated chemical vapor deposition (iCVD) process. A hydrophobic polymer, poly(2,4,6,8-tetravinyl-2,4,6,8-tetramethyl cyclotetra-siloxane) (pV4D4), was deposited conformally on amphiphilic 3-dimensional (3D) melamine sponge to incorporate hydrophobicity as well as oleophilicity to the porous sponge surface, which is appropriate for absorbing oil component selectively from food extracts. Furthermore, the surface-modified sponge was capable of the isolation of Escherichia coli O157:H7 (E. coli O157:H7) from heterogeneous mixture with oil/water/food particles with undistinguisible efficiency compare to artificial model system. The surface-modified sponge developed in this study will be a novel platform for oil/water separation and isolation of foodborne pathogens directly from heterogeneous mixture to enhance the efficiency of molecular diagnostics.


Assuntos
Contagem de Colônia Microbiana/métodos , Escherichia coli O157/isolamento & purificação , Microbiologia de Alimentos , Infecções por Escherichia coli/prevenção & controle , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Porosidade
17.
J Hosp Infect ; 103(1): e61-e67, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30365969

RESUMO

BACKGROUND: Large imaging systems in hybrid operating rooms are used increasingly. However, the effect of these ceiling-mounted imaging systems on air quality during surgical procedures has not been studied to date. AIM: To evaluate the level of colony-forming units (cfu)/m3 near the surgical wound and near the instrument table during surgery. METHODS: Measurements were performed in four hybrid operating rooms at four different hospitals. During surgical procedures, at least three samples were taken with active slit air samplers. At the end of the day's surgical schedule, simulations involving movement of the ceiling-mounted system were also performed. The threshold value for the average cfu level during a surgical procedure was set at ≤10 cfu/m3, and for individual samples was set at ≤30 cfu/m3. RESULTS: The median value near the surgical wound was 1 cfu/m3 and at the instrument table was 2 cfu/m3. However, in one hybrid operating room (two procedures out of 16) where the instrument table was not positioned directly under the unidirectional flow (UDF) system, the threshold value for the average cfu level at the instrument table was exceeded. For one of these procedures, the maximum value for an individual sample was also exceeded. CONCLUSIONS: A ceiling-mounted imaging system in combination with a UDF system can result in cfu levels near the surgical wound and at the instrument table that are well below the threshold value of 10 cfu/m3 during surgery. If the instrument table is not positioned directly under the UDF system, the cfu level is higher.


Assuntos
Microbiologia do Ar , Contagem de Colônia Microbiana/métodos , Salas Cirúrgicas , Imagem Óptica/métodos , Humanos , Infecção da Ferida Cirúrgica/prevenção & controle , Ventilação/métodos
18.
Food Chem ; 274: 925-932, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30373029

RESUMO

A noise-free bacterial colony counting method identifying noise (i.e., sausage, bacon, and millet fragments) with similar colors or shapes to those of colonies was developed for food quality assessment. First, spectral features corresponding to colony cluster regions and background regions (agar medium and food fragments) were extracted after collection of hyperspectral images. A cluster-segmenting calibration model that could identify colony clusters and background regions was developed. Second, spectral features of colony centers and borders were extracted, and a colony-separating calibration model that could separate single colonies from clusters (multiple colonies contacting each other) was developed. Third, each pixel of an agar plate hyperspectral image was identified using established calibration models, enabling the colonies on the agar plate to be counted successfully (R2 = 0.9998). The results demonstrated that the proposed method could identify the noises caused by food fragments with similar colors or shapes to those of colonies.


Assuntos
Contagem de Colônia Microbiana/métodos , Microbiologia de Alimentos/métodos , Ágar , Calibragem , Contagem de Colônia Microbiana/instrumentação , Meios de Cultura/química , Processamento de Imagem Assistida por Computador , Produtos da Carne
19.
Int J Food Microbiol ; 289: 209-214, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30384192

RESUMO

The presence of biofilms in food industrial environments is one of the main causes associated with food product contamination by L. monocytogenes. Biofilm control in the food industry is very relevant to public health and finding reliable and realistic quantification methods is essential. The aim of this study is to compare five L. monocytogenes biofilm quantification methods - conventional plate count, TEMPO, DEM, VIDAS and qPCR - and to examine a biodetector to visually detect biofilms in industrial settings. Results show that depending on the biofilm matrix production, the recovery of cells that conform the biofilm can be low and therefore, if it is an indirect method, microbial counts can be underestimated. At a species level, the methods that did not present significant differences were plate count, TEMPO (P = 0.998), DEM and qPCR (P = 0.508), so correlation studies were performed which established high correlation for plate count and TEMPO, but not for DEM and qPCR. The VIDAS method was adjusted so that it could quantify the biofilms, but the standard curve only allowed counts from 7 Log CFU cm-2. Results also revealed that the different strains of L. monocytogenes possess different biofilm-forming abilities, although it was not possible to correlate the capacity to produce these structures with the distinct serotypes. Last, visually detecting biofilms on stainless steel coupons proved that in industrial environments nowadays they can be rapidly and qualitatively detected so that relevant decisions can immediately be taken.


Assuntos
Biofilmes , Contagem de Colônia Microbiana/métodos , Indústria de Processamento de Alimentos/métodos , Listeria monocytogenes/fisiologia , Técnicas In Vitro , Aço Inoxidável
20.
Curr Protoc Microbiol ; 52(1): e71, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30398694

RESUMO

Anabaena sp. strain PCC 7120 is a multicellular, filamentous, freshwater cyanobacterium that is capable of differentiating specialized heterocyst cells for nitrogen fixation. This unit includes protocols for the growth and maintenance of Anabaena appropriate for a research or teaching laboratory. Controlled induction and assessment of heterocyst development is also covered. © 2018 by John Wiley & Sons, Inc.


Assuntos
Anabaena/crescimento & desenvolvimento , Contagem de Colônia Microbiana/métodos , Criopreservação/métodos , Coloração e Rotulagem/métodos , Anabaena/genética , Anabaena/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Contagem de Colônia Microbiana/instrumentação , Meios de Cultura/metabolismo , Regulação Bacteriana da Expressão Gênica , Fixação de Nitrogênio
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