RESUMO
Updating the mosquito fauna occurring in a specific area is crucial, given that certain species serve as vectors capable of transmitting zoonotic arboviruses. This scientific note presents the first records of mosquitoes of the tribe Orthopodomyiini in the Yucatan Peninsula. Immature mosquitoes were collected on 2 occasions inside a large tree hole in Felipe Carrillo Puerto, Quintana Roo, Mexico. Thirteen adult specimens, reared from the immatures, were obtained and identified as Orthopodomyia kummi based on external characteristics of females and males. This species has been recorded in Panama, Costa Rica, El Salvador, Guatemala, Mexico, and marginally in the United States, but its presence in the Yucatan Peninsula had gone unnoticed until now. The knowledge about mosquitoes of the genus Orthopodomyia is limited, and their epidemiological importance remains uncertain. Therefore, further studies could provide insights into the ecological and infection dynamics associated with this species.
Assuntos
Distribuição Animal , Culicidae , Animais , México , Feminino , Masculino , Larva/crescimento & desenvolvimentoRESUMO
Mycobacteria, like other microorganisms, survive under different environmental variations by expressing an efficient adaptive response, oriented by regulatory elements, such as transcriptional repressors of the TetR family. These repressors in mycobacteria also appear to be related to cholesterol metabolism. In this study, we have evaluated the effect of a fatty acid (oleic-palmitic-stearic)/cholesterol mixture on some phenotypic and genotypic characteristics of a tetR-mutant strain (BCG_2177c mutated gene) of M. bovis BCG, a homologous of Rv2160A of M. tuberculosis. In order to accomplish this, we have analyzed the global gene expression of this strain by RNA-seq and evaluated its neutral-lipid storage capacity and potential to infect macrophages. We have also determined the macrophage response by measuring some pro- and anti-inflammatory cytokine expressions. In comparison with wild-type microorganisms, we showed that the mutation in the BCG_2177c gene did not affect the growth of M. bovis BCG in the presence of lipids but it probably modified the structure/composition of its cell envelope. Compared to with dextrose, an overexpression of the transcriptome of the wild-type and mutant strains was observed when these mycobacteria were cultured in lipids, mainly at the exponential phase. Twelve putative intracellular redox balance maintenance genes and four others coding for putative transcriptional factors (including WhiB6 and three TetR-like) were the main elements repeatedly overexpressed when cultured in the presence of lipids. These genes belonged to the central part of what we called the "genetic lipid signature" for M. bovis BCG. We have also found that all these mycobacteria genotypic changes affected the outcome of BCG-infected macrophages, being the mutant strain most adapted to persist longer inside the host. This high persistence result was also confirmed when mutant-infected macrophages showed overexpression of the anti-inflammatory cytokine TGF-ß versus pro-inflammatory cytokines. In summary, the lack of this TetR-like repressor expression, within a lipid environment, may help mycobacteria overcome intracellular redox stress and survive longer inside their host.
Assuntos
Infecções por Mycobacterium , Mycobacterium bovis , Mycobacterium tuberculosis , Vacina BCG , Colesterol/metabolismo , Citocinas/metabolismo , Humanos , Macrófagos/microbiologia , OxirreduçãoRESUMO
BACKGROUND: Maintaining viability of beneficial microorganisms applied to foods still constitutes an industrial challenge. Many microencapsulation methodologies have been studied to protect probiotic microorganisms and ensure their resistance from manufacturing through to consumption. However, in many Latin-American countries such as Argentina there are still no marketed food products containing microencapsulated beneficial bacteria. The objectives of this work were: (i) to obtain microcapsules containing Lactobacillus fermentum L23 and L. rhamnosus L60 in a milk protein matrix; and (ii) to evaluate the viability of microencapsulated lactobacilli exposed to long-term refrigerated storage, mid-high temperatures and simulated gastrointestinal conditions. RESULTS: The method of emulsification/rennet-catalyzed gelation of milk proteins used in this study led to high encapsulation yields for both strains (98.2-99%). Microencapsulated lactobacilli remained viable for 120 days at 4 °C, while free lactobacilli gradually lost their viability under the same conditions. Microencapsulation increased the resistance of lactobacilli to mid-high temperatures, since they showed survival rates of 95-99.3% at 50 °C, and of 72.5-74.4% at 65 °C. Under simulated gastric conditions, the microencapsulated lactobacilli counts were higher than 8.5 log CFU mL-1 and showed survival rates between 96.61% and 97.74%. Furthermore, in the presence of bile (0.5-2% w/v) the survival of microencapsulated strains was higher than 96%. CONCLUSION: The microencapsulation process together with the matrix of milk proteins used in this study protected beneficial Lactobacillus strains against these first simulated technological and physiological conditions. These findings suggest that this microencapsulation method could contribute to secure optimal amounts of living lactobacilli cells able to reach the intestine. © 2021 Society of Chemical Industry.
Assuntos
Lactobacillus , Probióticos , Cápsulas , Lactobacillus/fisiologia , Viabilidade Microbiana , Proteínas do LeiteRESUMO
INTRODUCTION: Currently, severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection is a major public health problem worldwide. Although most patients present a mild infection, effective strategies are required for patients who develop the severe disease. Anti-inflammatory treatment with JAK inhibitors has been considered in SARS-CoV-2. METHODS: In this study, we presented our experience in a group of severe SARS-CoV-2 Chilean patients. This prospective study was performed on consecutive patients presenting severe respiratory failure owing to COVID-19 or high-risk clinical condition associated with SARS-CoV-2, and who were treated with ruxolitinib for management of associated inflammation. Overall, 18 patients presenting SARS-CoV-2 viral-induced hyperinflammation were treated with ruxolitinib, with 16 patients previously treated with steroids, 4 with tocilizumab, and 3 with both treatments. RESULTS: Ten patients evolved with favorable response, including 7 patients admitted with severe respiratory failure (PaFi less than 200 mm Hg in high-flow nasal cannula), presenting complete regression of hyperinflammation, regression of the lung lesions, and subsequent discharge. In the remaining 8 patients, 25% showed reduced inflammation, but early discharge was not achieved owing to the slow evolution of respiratory failure. Unfortunately, 3 patients demonstrated a severe respiratory failure. The early initiation of ruxolitinib was found to be associated with better clinical evolution (p < 0.005). CONCLUSION: In this study, ruxolitinib resolved hyperinflammatory state in 55% of the patients, regardless of the previous steroid or tocilizumab therapy. Unfortunately, few patients demonstrated severe evolution despite ruxolitinib therapy. Notably, the treatment starting time appears to play an important role in achieving good outcomes. Further validation in randomized controlled trials is crucial.
Assuntos
COVID-19/complicações , Inflamação/tratamento farmacológico , Nitrilas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/uso terapêutico , COVID-19/patologia , COVID-19/virologia , Chile , Feminino , Humanos , Inflamação/etiologia , Masculino , Pessoa de Meia-Idade , Nitrilas/efeitos adversos , Estudos Prospectivos , Inibidores de Proteínas Quinases/efeitos adversos , Pirazóis/efeitos adversos , Pirimidinas/efeitos adversos , Insuficiência Respiratória/tratamento farmacológico , Insuficiência Respiratória/etiologia , SARS-CoV-2/isolamento & purificação , Esteroides/uso terapêutico , Trombocitopenia/etiologia , Resultado do TratamentoRESUMO
The introduction of glyphosate-resistant (GR) crops revolutionized weed management; however, the improper use of this technology has selected for a wide range of weeds resistant to glyphosate, referred to as superweeds. We characterized the high glyphosate resistance level of an Amaranthus hybridus population (GRH)-a superweed collected in a GR-soybean field from Cordoba, Argentina-as well as the resistance mechanisms that govern it in comparison to a susceptible population (GSH). The GRH population was 100.6 times more resistant than the GSH population. Reduced absorption and metabolism of glyphosate, as well as gene duplication of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) or its overexpression did not contribute to this resistance. However, GSH plants translocated at least 10% more 14C-glyphosate to the rest of the plant and roots than GRH plants at 9 h after treatment. In addition, a novel triple amino acid substitution from TAP (wild type, GSH) to IVS (triple mutant, GRH) was identified in the EPSPS gene of the GRH. The nucleotide substitutions consisted of ATA102, GTC103 and TCA106 instead of ACA102, GCG103, and CCA106, respectively. The hydrogen bond distances between Gly-101 and Arg-105 positions increased from 2.89 Å (wild type) to 2.93 Å (triple-mutant) according to the EPSPS structural modeling. These results support that the high level of glyphosate resistance of the GRH A. hybridus population was mainly governed by the triple mutation TAP-IVS found of the EPSPS target site, but the impaired translocation of herbicide also contributed in this resistance.
Assuntos
3-Fosfoshikimato 1-Carboxiviniltransferase/genética , Amaranthus/efeitos dos fármacos , Amaranthus/genética , Substituição de Aminoácidos , Glicina/análogos & derivados , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Argentina , Relação Dose-Resposta a Droga , Duplicação Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glicina/metabolismo , Glicina/farmacologia , Mutação/efeitos dos fármacos , Fosfatos/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/genética , Alinhamento de Sequência , Análise de Sequência de Proteína , Ácido Chiquímico/metabolismo , Glycine max , GlifosatoRESUMO
Amaranthus palmeri S. Watson is probably the worst glyphosate-resistant (GR) weed worldwide. The EPSPS (5-enolpyruvylshikimate-3-phosphate-synthase) gene amplification has been reported as the major target-site-resistance (TSR) mechanism conferring resistance to glyphosate in this species. In this study, TSR and non-target-site-resistance (NTSR) mechanisms to glyphosate were characterized in a putative resistant A. palmeri population (GRP), harvested in a GR soybean crop from Argentina. Glyphosate resistance was confirmed for the GRP population by dose-response assays. No evidence of TSR mechanisms, as well as glyphosate metabolism, was found in this population. Moreover, a susceptible population (GSP) that absorbed about 10% more herbicide than the GRP population was evaluated at different periods after treatment. The GSP population translocated about 20% more glyphosate to the remainder of the shoots and roots at 96 h after treatment than the control, while the GRP population retained 62% of herbicide in the treated leaves. This is the first case of glyphosate resistance in A. palmeri involving exclusively NTSR mechanisms.
Assuntos
Amaranthus/metabolismo , Glycine max/efeitos dos fármacos , Glicina/análogos & derivados , Herbicidas/metabolismo , Plantas Daninhas/metabolismo , 3-Fosfoshikimato 1-Carboxiviniltransferase/genética , 3-Fosfoshikimato 1-Carboxiviniltransferase/metabolismo , Amaranthus/efeitos dos fármacos , Argentina , Transporte Biológico , Glicina/metabolismo , Glicina/farmacologia , Resistência a Herbicidas , Herbicidas/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Glycine max/crescimento & desenvolvimento , GlifosatoRESUMO
Introducción: El Síndrome Metabólico (SM) es una epidemia y un problema de salud pública, debido a la creciente prevalencia de obesidad y estilos de vida poco saludables. Está asociado a un incremento de 5 veces de riesgo de Diabetes Mellitus tipo 2, y de 2 a 3 veces de aumento en el riesgo de enfermedad cardiovascular, con disminución en la supervivencia. Después de la menopausia, la prevalencia de SM aumenta todavía más, generando un aumento muy significativo del riesgo cardiovascular. Objetivos: Conocer la prevalencia de SM en pacientes internadas de enero a junio del 2017 en el Servicio de Ginecología HC-IPS y comparar la prevalencia de SM obtenida según criterios de la NCEP ATPIII y la IDF en mujeres pre menopáusicas y post menopáusicas. Metodología: Estudio retrospectivo, descriptivo de corte transversal. Resultados: De 380 pacientes observadas, el promedio de edades fue de 43 años.77 % tenían un IMC mayor a 25. 56,8 % eran pre menopáusicas y 43,1 % post menopáusicas. La prevalencia de SM fue diferente según criterios de NCEP ATPIII y la IDF, siendo 23,1 % con el primero y 63 % con el segundo. Se encontró que 80% de las pre menopáusicas y 90 % de las post menopáusicas presentaban IMC mayor a 25. La patología ginecológica mayormente asociada fue el engrosamiento endometrial, observado en un 18% de los casos de SM en las post menopáusicas. En las pre menopáusicas se observó que en el 40% el SM estaba relacionado a HUA y miomatosis uterina. El porcentaje de cáncer endometrial fue bastante importante siendo del 11%. Palabras claves: menopausia, hipertensión, diabetes.
Introduction: The Metabolic Syndrome (MS) is an epidemic and a public health problem, due to the growing prevalence of obesity and unhealthy lifestyles. It is associated with a 5-fold increase in the risk of Diabetes Mellitus type 2, and a 2 to 3-fold increase in the risk of cardiovascular disease, with a decrease in survival. After menopause, the prevalence of MS increases even more, generating a very significant increase in cardiovascular risk. Objectives: To know the prevalence of MS in patients hospitalized from January to June 2017 in the HC-IPS Gynecology Service and to compare the prevalence of MS obtained according to NCEP ATPIII and IDF criteria in premenopausal and postmenopausal women. Methodology: Retrospective, descriptive crosssectional study. Results: Of 380 patients observed, the average age was 43.77% had a BMI greater than 25. 56.8% were premenopausal and 43.1% postmenopausal. The prevalence of MS was different according to the criteria of NCEP ATPIII and the IDF, being 23.1% with the first and 63% with the second. It was found that 80% of premenopausal and 90% of postmenopausal women had a BMI greater than 25. The gynecological pathology most associated was endometrial thickening, observed in 18% of cases of MS in postmenopausal women. In premenopausal women it was observed that in 40% the MS was related to HUA and uterine myomatosis. The percentage of endometrial cancer was quite important being 11%. Keywords: menopause, hypertension, diabetes
Assuntos
Humanos , Feminino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/complicações , Diabetes Mellitus/metabolismo , Ginecologia/estatística & dados numéricos , Hipertensão/metabolismo , Obesidade/complicaçõesRESUMO
Isolates of the Mycobacterium chelonae-M. abscessus complex are subdivided into four clusters (CHI to CHIV) in the INNO-LiPA® Mycobacterium spp DNA strip assay. A considerable phenotypic variability was observed among isolates of the CHII cluster. In this study, we examined the diversity of 26 CHII cluster isolates by phenotypic analysis, drug susceptibility testing, whole genome sequencing and single-gene analysis. Pairwise genome comparisons were performed using several approaches, including average nucleotide identity (ANI) and genome-to-genome distance (GGD) among others. Based on ANI and GGD the isolates were identified as M. chelonae (14 isolates), M. franklinii (2 isolates) and M. salmoniphium (1 isolate). The remaining 9 isolates were subdivided into three novel putative genomospecies. Phenotypic analyses including drug susceptibility testing, as well as whole genome comparison by TETRA and delta differences, were not helpful in separating the groups revealed by ANI and GGD. The analysis of standard four conserved genomic regions showed that rpoB alone and the concatenated sequences clearly distinguished the taxonomic groups delimited by whole genome analyses. In conclusion, the CHII INNO-LiPa is not a homogeneous cluster; on the contrary, it is composed of closely related different species belonging to the M. chelonae-M. abscessus complex and also several unidentified isolates. The detection of these isolates, putatively novel species, indicates a wider inner variability than the presently known in this complex.
RESUMO
Isolates of the Mycobacterium chelonae-M. abscessus complex are subdivided into four clusters (CHI to CHIV) in the INNO-LiPA® Mycobacterium spp DNA strip assay. A considerable phenotypic variability was observed among isolates of the CHII cluster. In this study, we examined the diversity of 26 CHII cluster isolates by phenotypic analysis, drug susceptibility testing, whole genome sequencing and single-gene analysis. Pairwise genome comparisons were performed using several approaches, including average nucleotide identity (ANI) and genome-to-genome distance (GGD) among others. Based on ANI and GGD the isolates were identified as M. chelonae (14 isolates), M. franklinii (2 isolates) and M. salmoniphium (1 isolate). The remaining 9 isolates were subdivided into three novel putative genomospecies. Phenotypic analyses including drug susceptibility testing, as well as whole genome comparison by TETRA and delta differences, were not helpful in separating the groups revealed by ANI and GGD. The analysis of standard four conserved genomic regions showed that rpoB alone and the concatenated sequences clearly distinguished the taxonomic groups delimited by whole genome analyses. In conclusion, the CHII INNO-LiPa is not a homogeneous cluster; on the contrary, it is composed of closely related different species belonging to the M. chelonae-M. abscessus complex and also several unidentified isolates. The detection of these isolates, putatively novel species, indicates a wider inner variability than the presently known in this complex. (AU)
Assuntos
Classificação , Mycobacterium chelonae , Mycobacterium abscessus , Sequenciamento Completo do GenomaRESUMO
The aim of the present study was to investigate the inhibitory activity of lactic acid bacteria (LAB) isolated from brewer's grains on Aspergillus section Flavi growth and aflatoxin B1 production. The Aspergillus strains tested were inhibited by all the LAB strains assayed. The isolates Lactobacillus brevis B20, P. pentosaceus B86, Lactococcus lactis subsp. lactis B87, L. brevis B131, and Lactobacillus sp. B144 completely suppressed the fungal growth and reduced aflatoxin B1 production. In conclusion, LAB isolated from brewer's grains show a high inhibitory activity on fungal growth and aflatoxin biosynthesis by Aspergillus flavus and Aspergillus parasiticus. Further studies must be conducted to evaluate the success of in vitro assays under food environment conditions and to elucidate the antifungal mechanism of these strains.
Assuntos
Aflatoxina B1/metabolismo , Ração Animal/microbiologia , Aspergillus flavus/crescimento & desenvolvimento , Agentes de Controle Biológico , Microbiologia de Alimentos , Lactobacillus , Pediococcus , Animais , Argentina , Aspergillus flavus/metabolismo , Biomarcadores/metabolismo , SuínosRESUMO
PURPOSE: To analyze the effect of germline mutations in BRCA1 and BRCA2 on mortality in patients with ovarian cancer up to 10 years after diagnosis. EXPERIMENTAL DESIGN: We used unpublished survival time data for 2,242 patients from two case-control studies and extended survival time data for 4,314 patients from previously reported studies. All participants had been screened for deleterious germline mutations in BRCA1 and BRCA2. Survival time was analyzed for the combined data using Cox proportional hazard models with BRCA1 and BRCA2 as time-varying covariates. Competing risks were analyzed using Fine and Gray model. RESULTS: The combined 10-year overall survival rate was 30% [95% confidence interval (CI), 28%-31%] for non-carriers, 25% (95% CI, 22%-28%) for BRCA1 carriers, and 35% (95% CI, 30%-41%) for BRCA2 carriers. The HR for BRCA1 was 0.53 at time zero and increased over time becoming greater than one at 4.8 years. For BRCA2, the HR was 0.42 at time zero and increased over time (predicted to become greater than 1 at 10.5 years). The results were similar when restricted to 3,202 patients with high-grade serous tumors and to ovarian cancer-specific mortality. CONCLUSIONS: BRCA1/2 mutations are associated with better short-term survival, but this advantage decreases over time and in BRCA1 carriers is eventually reversed. This may have important implications for therapy of both primary and relapsed disease and for analysis of long-term survival in clinical trials of new agents, particularly those that are effective in BRCA1/2 mutation carriers.
Assuntos
Genes BRCA1 , Genes BRCA2 , Mutação em Linhagem Germinativa , Neoplasias Epiteliais e Glandulares/genética , Neoplasias Epiteliais e Glandulares/mortalidade , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/mortalidade , Idoso , Carcinoma Epitelial do Ovário , Feminino , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Neoplasias Epiteliais e Glandulares/patologia , Neoplasias Ovarianas/patologia , Prognóstico , Análise de SobrevidaRESUMO
UNLABELLED: Strong evidence supports the idea that fatty acids rather than carbohydrates are the main energy source of Mycobacterium tuberculosis during infection and latency. Despite that important role, a complete scenario of the bacterium's metabolism when lipids are the main energy source is still lacking. Here we report the development of an in vitro model to analyze adaptation of M. tuberculosis during assimilation of long-chain fatty acids as sole carbon sources. The global lipid transcriptome revealed a shift toward the glyoxylate cycle, the overexpression of main regulators whiB3, dosR, and Rv0081, and the increased expression of several genes related to reductive stress. Our evidence showed that lipid storage seems to be the selected mechanism used by M. tuberculosis to ameliorate the assumed damage of reductive stress and that concomitantly the bacilli acquired a slowed-growth and drug-tolerant phenotype, all characteristics previously associated with the dormant stage. Additionally, intergenic regions were also detected, including the unexpected upregulation of tRNAs that suggest a new role for these molecules in the acquisition of a drug-tolerant phenotype by dormant bacilli. Finally, a set of lipid signature genes for the adaptation process was also identified. This in vitro model represents a suitable condition to illustrate the participation of reductive stress in drugs' activity against dormant bacilli, an aspect scarcely investigated to date. This approach provides a new perspective to the understanding of latent infection and suggests the participation of previously undetected molecules. IMPORTANCE: Mycobacterium tuberculosis establishes long-lasting highly prevalent infection inside the human body, called latent tuberculosis. The known involvement of fatty acids is changing our understanding of that silent infection; however, question of how tubercle bacilli globally adapt to a lipid-enriched environment is still an unanswered. With the single change of providing fatty acids as carbon sources, the bacilli switch on their program related to dormant stage: slowed growth, accumulation of lipid bodies, and development of drug tolerance. In this stage, unexpected and previously unknown participants were found to play putatively important roles during the process. For the first time, this work compares the global transcriptomics of bacteria by using strand-specific RNA sequencing under two different growth conditions. This study suggests novel targets for the control of tuberculosis and provides a new straightforward in vitro model that could help to test the activity of drugs against dormant bacilli from a novel perspective.
Assuntos
Adaptação Biológica , Interação Gene-Ambiente , Metabolismo dos Lipídeos , Mycobacterium tuberculosis/fisiologia , Fenótipo , Carbono/metabolismo , Metabolismo Energético , Ácidos Graxos/metabolismo , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Modelos BiológicosRESUMO
Group B streptococci (GBS) are bacterial species that colonize the vagina in pregnant women and as such may cause serious infections in neonates that passed through the birth channel. The objective of this work was to study the inhibitory activities produced by each bacteriocin-like inhibitory substance (BLIS) of Lactobacillus rhamnosus L60 and Lactobacillus fermentum L23, and the effects of the combined BLIS-es of these lactobacilli on GBS. The interactions between the BLIS-es were assessed by qualitative and quantitative methods on agar plates. The minimum inhibitory concentrations (MICs) and fractional inhibitory concentrations (FICs) were determined by a modification of the broth microdilution and checkerboard methods, respectively. Antibiotic susceptibilities of all S. agalactiae strains were assayed and the results of these tests were evaluated for statistical significance. A 7.5% of GBS isolates were recovered from 760 pregnant women and 91% of those strains were susceptible to each BLIS produced by L. fermentum, L. rhamnosus, and also to a mixture of them. The comparisons among the BLIS-es showed statistically significant differences, with a combination of the BLIS-es from the two Lactobacillus species being better than the BLIS of each one alone (P < 0.05) as GBS growth inhibitors. Synergistic activities between the BLIS-es were found on 100% of susceptible GBS strains, MICs ranges of BLIS of L23 and L60 were 80-160 and 160-320 UA ml(-1), respectively. By the checkerboard method, the BLIS-es combination showed synergistic effect on all sensitive strains tested, with values of FICs ranging from 0.131 to 0.218. The BLIS-es produced by these lactobacilli of vaginal origin were able to inhibit S. agalactiae isolates. The results indicate that these strains may have probiotic potential for the control of GBS in women and may consequently prevent GBS infections in newborns.
Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Sinergismo Farmacológico , Lacticaseibacillus rhamnosus/metabolismo , Limosilactobacillus fermentum/metabolismo , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/crescimento & desenvolvimento , Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Feminino , Humanos , Limosilactobacillus fermentum/classificação , Limosilactobacillus fermentum/genética , Limosilactobacillus fermentum/isolamento & purificação , Lacticaseibacillus rhamnosus/classificação , Lacticaseibacillus rhamnosus/genética , Lacticaseibacillus rhamnosus/isolamento & purificação , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Filogenia , Gravidez , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Infecções Estreptocócicas/microbiologia , Streptococcus agalactiae/isolamento & purificação , Vagina/microbiologiaRESUMO
The diagnosis of tuberculosis in developing countries still relies on direct sputum examination by light microscopy, a method that is easy to perform and that is widely applied. However, because of its poor sensitivity and requirement for significant labor and training, light microscopy examination detects the bacilli in only 45 to 60% of all people whose specimens are culture positive for Mycobacterium tuberculosis. Therefore, new diagnostic methods that would enable the detection of the undiagnosed infected population and allow the early commencement of antituberculosis treatment are needed. In this work, the potential use of mycobacterial cyan autofluorescence for the detection of Mycobacterium tuberculosis was explored. The tubercle bacilli were easily visualized as brilliant fluorescent bacilli by microscopy and were easily tracked ex vivo during macrophage infection. Assays with seeded sputum and a 96-well microplate reader fluorimeter indicated that <10(6) bacilli ml(-1) of sputum could be detected. Moreover, the use of microplates allowed the examination of only 200 microl of sputum per sample without a loss of sensitivity. Treatment with heat or decontaminating chemical agents did not interfere with the autofluorescence assay; on the contrary, they improved the level of bacterial detection. Autofluorescence for the detection of bacilli is rapid and easy to perform compared to other methodologies and can be performed with minimal training, making this method suitable for implementation in developing countries.
Assuntos
Técnicas Bacteriológicas/métodos , Fluorescência , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/diagnóstico , Humanos , Microscopia de Fluorescência/métodos , Mycobacterium tuberculosis/química , Sensibilidade e EspecificidadeRESUMO
Human clinical isolates of the Mycobacterium avium complex, from hospitals in Bogotá, were studied using a wide range of molecular tests including PCR restriction-enzyme analysis (PRA) of the hsp65 gene. Up to 21 of the isolates were identified as M. avium PRA variant III (Mav III), a variant obtained only from isolates on the American continent. In contrast to previous reports, restriction fragment length polymorphism analysis using IS1245 and IS1311 showed a single copy for each insertion sequence (IS) in the majority (19/21) of the Colombian Mav III isolates under study. In order to analyse whether the ISs were inserted in a relevant genomic region, experimental conditions were established to determine the insertion loci of each single copy of both ISs in the genome. Analysis of genomic insertion loci indicated that both IS1245 and IS1311 were present in areas containing putatively truncated integrases and/or transposases, which may have an influence on the mobility of the inserted IS. In addition, a conserved genomic region was identified for the insertion of IS1311; this region could be part of the IS1311 itself.
Assuntos
Elementos de DNA Transponíveis , Genoma Bacteriano , Complexo Mycobacterium avium/classificação , Complexo Mycobacterium avium/genética , Infecção por Mycobacterium avium-intracellulare/microbiologia , Proteínas de Bactérias/genética , Sequência de Bases , Análise por Conglomerados , Colômbia , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , Genótipo , Hospitais , Humanos , Integrases/genética , Dados de Sequência Molecular , Complexo Mycobacterium avium/isolamento & purificação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Sequência de DNA , Transposases/genéticaRESUMO
Forty-five mycobacterial strains isolated from 23 Colombian HIV-positive patients were identified as members of the Mycobacterium avium complex (MAC) and were characterized using different molecular approaches. Seven of the isolates showed characteristic features that allowed them to be differentiated from other members of the complex. The isolates had a novel 16S-23S rRNA internal transcribed spacer (ITS 1) gene sequence which is described as a new sequevar, MAC-X. All of the seven novel isolates gave a positive result with the MAC-specific AccuProbe (Gen-Probe), but tested negative for Mycobacterium avium and Mycobacterium intracellulare species-specific probes (64 and 100 % of the isolates, respectively). The novel isolates could be differentiated phenotypically from other members of the MAC on the basis of the production of urease and by a consistent mycolic acid pattern. The novel isolates shared some characteristics with M. avium, such as the avium variant I (av-I) pattern of the hsp65 gene as determined by PCR restriction analysis and a positive PCR result for the mig (macrophage-induced) gene. However, the novel isolates showed a unique 16S rRNA gene sequence. DNA-DNA relatedness values, from 24 to 44 %, confirmed the distinction of the novel isolates from other members of the MAC at the genetic level and their status as members of a separate species. The novel isolates are proposed as representatives of a novel species, Mycobacterium colombiense sp. nov., that is closely related to M. avium within the MAC. The type strain is 10B(T) (=CIP 108962(T)=CECT 3035(T)).