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1.
Sci Rep ; 14(1): 8163, 2024 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589435

RESUMO

Despite several studies conducted to investigate housing factors, the effects of housing construction materials on childhood ARI symptoms in Bangladesh remain unclear. Hence, the study aimed to measure such a correlation among children under the age of five. A hospital-based case-control study was conducted, involving 221 cases and 221 controls from January to April 2023. Bivariate and multivariate binary logistic regression was performed to measure the degree of correlation between housing construction materials and childhood ARI symptoms. Households composed of natural floor materials had 2.7 times (95% confidence interval 1.27-5.57) and households composed of natural roof materials had 1.8 times (95% confidence interval 1.01-3.11) higher adjusted odds of having under-five children with ARI symptoms than household composed of the finished floor and finished roof materials respectively. Households with natural wall type were found protective against ARI symptoms with adjusted indoor air pollution determinants. The study indicates that poor housing construction materials are associated with an increased risk of developing ARI symptoms among under-five children in Bangladesh. National policy regarding replacing poor housing materials with concrete, increasing livelihood opportunities, and behavioral strategies programs encouraging to choice of quality housing construction materials could eliminate a fraction of the ARI burden.


Assuntos
Poluição do Ar em Ambientes Fechados , Infecções Respiratórias , Humanos , Criança , Lactente , Habitação , Estudos de Casos e Controles , Bangladesh/epidemiologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/prevenção & controle , Infecções Respiratórias/etiologia , Materiais de Construção , Poluição do Ar em Ambientes Fechados/efeitos adversos , Poluição do Ar em Ambientes Fechados/análise , Fatores de Risco
2.
Front Cell Infect Microbiol ; 13: 1222913, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37662005

RESUMO

Tick-borne Babesiosis is a parasitic infection caused by Babesia microti that can infect both animals and humans and may spread by tick, blood transfusions, and organ transplantation. The current therapeutic options for B. microti are limited, and drug resistance is a concern. This study proposes using computational drug design approaches to find and design an effective drug against B. microti. The study investigated the potentiality of nine natural compounds against the pathogenic human B. microti parasite and identified Vasicinone and Evodiamine as the most promising drugs. The ligand structures were optimized using density functional theory, molecular docking, molecular dynamics simulations, quantum mechanics such as HOMO-LUMO, drug-likeness and theoretical absorption, distribution, metabolism, excretion, and toxicity (ADMET), and pharmacokinetics characteristics performed. The results showed that Vasicinone (-8.6 kcal/mol and -7.8 kcal/mol) and Evodiamine (-8.7 kcal/mol and -8.5 kcal/mol) had the highest binding energy and anti-parasitic activity against B. microti lactate dehydrogenase and B. microti lactate dehydrogenase apo form. The strongest binding energy was reported by Vasicinone and Evodiamine; the compounds were evaluated through molecular dynamics simulation at 100 ns, and their stability when they form complexes with the targeted receptors was determined. Finally, the pkCSM web server is employed to predict the ADMET qualities of specific molecules, which can help prevent negative effects that arise from taking the treatment. The SwissADME web server is used to assess the Lipinski rule of five and drug-likeness properties including topological polar surface area and bioavailability. The Lipinski rule is used to estimate significant drug-likeness. The theoretical pharmacokinetics analysis and drug-likeness of the selected compounds are confirmed to be accepted by the Lipinski rule and have better ADMET features. Thus, to confirm their experimental value, these mentioned molecules should be suggested to carry out in wet lab, pre-clinical, and clinical levels.


Assuntos
Babesia microti , Gastrópodes , Parasitos , Animais , Humanos , Simulação de Acoplamento Molecular , Desenho de Fármacos , Descoberta de Drogas , L-Lactato Desidrogenase
3.
Heliyon ; 9(7): e18203, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37519685

RESUMO

A study was carried out in five sweet potato growing regions of Bangladesh, each characterized by suitable agro-ecologies, in order to demonstrate the most favorable varietal performance and trait correlations. A completely randomized block design with three replications was used to compare the varietal performance of BARI (Bangladesh Agricultural Research Institute) released sweet potato varieties (viz. BARI Mistialu-9, BARI Mistialu-10, BARI Mistialu-12, BARI Mistialu-15 and BARI Mistialu-17). During the 2021-22 cropping season, sweet potato varieties were tested in five districts of Bangladesh, namely Gazipur, Bogura, Jamalpur, Jashore, and Chattogram. The findings revealed that the BARI Mistialu-12 variety exhibited remarkable attributes, including a high marketable storage root yield of 39.88 t/ha. Additionally, it demonstrated exceptional performance in various yield components such as vine length, average storage root weight, and dry weight of the root. Furthermore, a positive correlation was observed between several traits and yield, as well as yield-attributing characteristics. This correlation suggests that enhancing these traits could potentially contribute to an overall increase in the storage root yield of sweet potatoes.

4.
PLoS One ; 18(4): e0284391, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37053255

RESUMO

BACKGROUND: The government of Bangladesh has been trying to encourage potato consumption to reduce pressure on rice consumption and earn foreign currency along with ensuring zero hunger that helps to achieve the Sustainable Development Goal. It is necessary to use farmers' resources and current technology more efficiently to meet the demand. Therefore, the authors aimed to evaluate the farm-level efficiency of potato farming in Bangladesh. METHODS AND MATERIALS: The Cobb-Douglas Stochastic Frontier Analysis (SFA) and the input-oriented Data Envelopment Analysis (DEA) methods are used to compute farm-level technical, allocative, and economic efficiencies and inefficiency of potato farming. The primary data were collected through interviews of 300 potato farmers from Munshigonj, Rangpur, Dinajpur, and Joypurhat districts of Bangladesh. RESULTS: The findings revealed that the efficiency score of the SFA model is higher than the DEA model, which implies that the SFA frontier fits better than the DEA frontier. In the case of DEA, variable returns to scale (VRS) technical efficiency (TE) enveloped data more closely than constant returns to scale (CRS) TE. Results of efficiency suggest significant economic, technical, and allocative inefficiencies in potato farming and there is a scope to increase potato production levels through efficiency improvement. Inefficiency analysis shows that infrastructure and socio-economic factors jointly influence potato production variability. CONCLUSIONS: The authors suggest for using the SFA to find efficiencies in the agriculture sector. To achieve efficiency in potato production, the government needs to pay attention for improving the allocative and economic efficiencies along with emphasizing to choose the appropriate technology and efficient use of resources for the scale of operation.


Assuntos
Solanum tuberosum , Humanos , Fazendas , Agricultura/métodos , Eficiência , Fazendeiros
5.
Cell ; 185(23): 4280-4297.e12, 2022 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-36323316

RESUMO

The gut microbiome has an important role in infant health and development. We characterized the fecal microbiome and metabolome of 222 young children in Dhaka, Bangladesh during the first two years of life. A distinct Bifidobacterium longum clade expanded with introduction of solid foods and harbored enzymes for utilizing both breast milk and solid food substrates. The clade was highly prevalent in Bangladesh, present globally (at lower prevalence), and correlated with many other gut taxa and metabolites, indicating an important role in gut ecology. We also found that the B. longum clades and associated metabolites were implicated in childhood diarrhea and early growth, including positive associations between growth measures and B. longum subsp. infantis, indolelactate and N-acetylglutamate. Our data demonstrate geographic, cultural, seasonal, and ecological heterogeneity that should be accounted for when identifying microbiome factors implicated in and potentially benefiting infant development.


Assuntos
Bifidobacterium longum , Lactente , Criança , Feminino , Humanos , Pré-Escolar , Bifidobacterium longum/metabolismo , Bifidobacterium/metabolismo , Desmame , Oligossacarídeos/metabolismo , Bangladesh , Leite Humano , Fezes/microbiologia
7.
Front Hum Neurosci ; 15: 748893, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34744663

RESUMO

Objective: To clarify whether long time constant (TC) is useful for detecting the after-slow activity of epileptiform discharges (EDs): sharp waves and spikes and for differentiating EDs from sharp transients (Sts). Methods: We employed 68 after-slow activities preceded by 32 EDs (26 sharp waves and six spikes) and 36 Sts from 52 patients with partial and generalized epilepsy (22 men, 30 women; mean age 39.08 ± 13.13 years) defined by visual inspection. High-frequency activity (HFA) associated with the apical component of EDs and Sts was also investigated to endorse two groups. After separating nine Sts that were labeled by visual inspection but did not fulfill the amplitude criteria for after-slow of Sts, 59 activities (32 EDs and 27 Sts) were analyzed about the total area of after-slow under three TCs (long: 2 s; conventional: 0.3 s; and short: 0.1 s). Results: Compared to Sts, HFA was found significantly more with the apical component of EDs (p < 0.05). The total area of after-slow in all 32 EDs under TC 2 s was significantly larger than those under TC 0.3 s and 0.1 s (p < 0.001). Conversely, no significant differences were observed in the same parameter of 27 Sts among the three different TCs. Regarding separated nine Sts, the total area of after-slow showed a similar tendency to that of 27 Sts under three different TCs. Significance: These results suggest that long TC could be useful for selectively endorsing after-slow of EDs and differentiating EDs from Sts. These findings are concordant with the results of the HFA analysis. Visual inspection is also equally good as the total area of after-slow analysis.

8.
mSphere ; 6(6): e0068621, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34756056

RESUMO

Acute respiratory infections (ARIs) are one of the most common causes of morbidity and mortality in young children. The aim of our study was to examine whether variation in maternal FUT2 (α1,2-fucosyltransferase 2) and FUT3 (α1,3/4-fucosyltransferase 3) genes, which shape fucosylated human milk oligosaccharides (HMOs) in breast milk, are associated with the occurrence of ARIs in breastfed infants as well as the influence of the nasopharyngeal microbiome on ARI risk. Occurrences of ARIs were prospectively recorded in a cohort of 240 breastfed Bangladeshi infants from birth to 2 years. Secretor and Lewis status was established by sequencing of FUT2/3 genes. The nasopharyngeal microbiome was characterized by shotgun metagenomics, complemented by specific detection of respiratory pathogens; 88.6% of mothers and 91% of infants were identified as secretors. Maternal secretor status was associated with reduced ARI incidence among these infants in the period from birth to 6 months (incidence rate ratio [IRR], 0.66; 95% confidence interval [CI], 0.47 to 0.94; P = 0.020), but not at later time periods. The nasopharyngeal microbiome, despite precise characterization to the species level, was not predictive of subsequent ARIs. The observed risk reduction of ARIs among infants of secretor mothers during the predominant breastfeeding period is consistent with the hypothesis that fucosylated oligosaccharides in human milk contribute to protection against respiratory infections. However, we found no evidence that modulation of the nasopharyngeal microbiome influenced ARI risk. IMPORTANCE The observed risk reduction of acute respiratory infections (ARIs) among infants of secretor mothers during the predominant breastfeeding period is consistent with the hypothesis that fucosylated oligosaccharides in human milk contribute to protection against respiratory infections. Respiratory pathogens were only weak modulators of risk, and the nasopharyngeal microbiome did not influence ARI risk, suggesting that the associated protective effects of human milk oligosaccharides (HMOs) are not conveyed via changes in the nasopharyngeal microbiome. Our observations add to the evidence for a role of fucosylated HMOs in protection against respiratory infections in exclusively or predominantly breastfed infants in low-resource settings. There is no indication that the nasopharyngeal microbiome substantially modulates the risk of subsequent mild ARIs. Larger studies are needed to provide mechanistic insights on links between secretor status, HMOs, and risk of respiratory infections.


Assuntos
Bactérias/classificação , Aleitamento Materno , Fucosiltransferases/metabolismo , Microbioma Gastrointestinal , Leite Humano/metabolismo , Bactérias/crescimento & desenvolvimento , Bangladesh , Feminino , Humanos , Lactente , Masculino , Mães , Infecções Respiratórias/microbiologia
9.
Odontology ; 109(3): 661-671, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33475895

RESUMO

The aim of this study was to determine whether histone deacetylase inhibitors (HDACi), including entinostat (MS-275), valproic acid (VPA), trichostatin A (TSA), and sodium butyrate (NaB), promoted the odontogenic differentiation of the odontoblast-like cell line, MDPC-23 in the absence of an osteoblast mineralization medium. The cells were cultured in basal medium (Dulbecco's modified Eagle medium) with and without (controls) the inhibitors. The cell viability and migration were assessed using the cell proliferation reagent WST-1 and a scratch wound healing assay, respectively. The mRNA expression levels of bone morphogenetic protein (Bmp)-2 and -4, collagen 1 alpha 1 (Col1α1), osteocalcin (Oc), dentin matrix protein 1 (Dmp1), dentin sialophosphoprotein (Dspp), runt-related transcription factor 2 (Runx2), Krueppel-like factor 5 (Klf5), and Msh homeobox 1 (Msx1) were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Alizarin red and alkaline phosphatase assays were performed to determine the extent of mineralization in the culture systems. No significant differences in cell numbers were observed between the controls and the MS-275-, VPA-, and NaB-treated cells; however, a significant difference was observed with TSA (concentration, 1000 nM). The scratch wound healing assay showed no effect of cell migration in the MS-275 (1.0 µM)-treated cells when compared with the controls at 24 h. Furthermore, MS-275, VPA, and NaB increased the mRNA expression levels of Bmp-2 and -4, Oc, and Runx2 followed by the mineralization of the cells. Only MS-275 significantly increased the expression levels of Dmp1, Dspp, Klf5, and Msx1 in the cells. These findings indicated that MS-275 may be considered as a reliable candidate for the odontogenic differentiation of dental pulp cells.


Assuntos
Inibidores de Histona Desacetilases , Odontoblastos , Benzamidas , Diferenciação Celular , Linhagem Celular , Polpa Dentária , Inibidores de Histona Desacetilases/farmacologia , Osteoblastos , Piridinas
10.
Front Pediatr ; 9: 728382, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35083183

RESUMO

Objectives: Risk factors for acute respiratory infections (ARIs) in community settings are not fully understood, especially in low-income countries. We examined the incidence and risk factors associated with ARIs in under-two children from the Microbiota and Health study. Methods: Children from a peri-urban area of Dhaka (Bangladesh) were followed from birth to 2 years of age by both active surveillance of ARIs and regular scheduled visits. Nasopharyngeal samples were collected during scheduled visits for detection of bacterial facultative respiratory pathogens. Information on socioeconomic, environmental, and household conditions, and mother and child characteristics were collected. A hierarchical modeling approach was used to identify proximate determinants of ARIs. Results: Of 267 infants, 87.3% experienced at least one ARI episode during the first 2 years of life. The peak incidence of ARIs was 330 infections per 100 infant-years and occurred between 2 and 4 months of age. Season was the main risk factor (rainy monsoon season, incidence rate ratio [IRR] 2.43 [1.92-3.07]; cool dry winter, IRR 2.10 [1.65-2.67] compared with hot dry summer) in the first 2 years of life. In addition, during the first 6 months of life, young maternal age (<22 years; IRR 1.34 [1.01-1.77]) and low birth weight (<2,500 g; IRR 1.39 [1.03-1.89]) were associated with higher ARI incidence. Conclusions: Reminiscent of industrialized settings, cool rainy season rather than socioeconomic and hygiene conditions was a major risk factor for ARIs in peri-urban Bangladesh. Understanding the causal links between seasonally variable factors such as temperature, humidity, crowding, diet, and ARIs will inform prevention measures.

11.
Epilepsy Behav Case Rep ; 11: 18-21, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30591883

RESUMO

To clarify the effects of sleep on cortical irritability in benign adult familial myoclonus epilepsy (BAFME), we retrospectively compared epileptiform discharges of electroencephalographies (EEGs) between awake and sleep periods in 5 patients (mean age: 49.6 ±â€¯20.3 years). We also analyzed polysomnography (PSG) of 1 patient. Epileptiform discharges were significantly more frequent during the awake period (1.3 ±â€¯1.2/min) than those during light sleep stages (0.02 ±â€¯0.04/min) (P < 0.05). Regarding PSG analysis, epileptiform discharges were also reduced during all sleep stages compared to those during awake periods. Our study suggests a relative reduction in cortical irritability during sleep in BAFME.

12.
Am J Gastroenterol ; 113(9): 1363-1375, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30171215

RESUMO

BACKGROUND: Postinfection irritable bowel syndrome (PI-IBS) and functional dyspepsia (PI-FD), though reported from the temperate countries, have not been studied in the tropics; PI-malabsorption syndrome (MAS), which mimics PI-IBS, is reported from the tropics. No report till date on PI-IBS excluded PI-MAS. We studied: (i) the frequency of continuing bowel dysfunction after acute gastroenteritis (AG), (ii) its predictors, and (iii) PI-MAS among patients with PI-IBS. METHODS: 345 consecutive subjects each, with AG and age- and gender-matched healthy controls were followed up 3-monthly for 12 months using a translated-validated questionnaire and functional gastrointestinal disorders (FGIDs) were diagnosed by Rome III criteria. Symptom duration >3 months but <6 months was diagnosed as chronic bowel dysfunction (CBD) and dyspeptic symptoms, respectively. MAS was diagnosed if 2/3 tests (D-xylose H2 breath test, Sudan III-stained stool microscopy, and duodenal histology) were abnormal. Fecal microbiological studies were performed in 245/345 (71%) patients. RESULTS: AG patients more often developed PI-IBS and PI-FD than controls (16.5 vs. 2.6% and 7.4 vs. 0.6%, respectively; p<0.001). Presence of FD was a risk factor for PI-IBS and IBS for PI-FD. On multivariate analysis, dyspeptic symptoms, CBD, and weight loss were the risk factors for PI-FGIDs. The frequency of PI-IBS following Vibrio cholera and other bacterial infection was comparable. Malabsorption was present among 2/23 (9%) patients with PI-IBS. CONCLUSION: FGIDs are common after AG; dyspeptic symptoms, CBD, and weight loss were risk factors for PI-FGIDs. Vibrio cholerae infection caused PI-FGID, which was never reported. About 9 % patients fulfilling the criteria for PI-IBS had PI-MAS.


Assuntos
Infecções Bacterianas/complicações , Diarreia/complicações , Dispepsia/epidemiologia , Gastroenterite/complicações , Síndrome do Intestino Irritável/epidemiologia , Adulto , Bactérias/isolamento & purificação , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Bangladesh/epidemiologia , Estudos de Casos e Controles , Doença Crônica/epidemiologia , Diarreia/diagnóstico , Diarreia/microbiologia , Dispepsia/diagnóstico , Dispepsia/etiologia , Feminino , Seguimentos , Gastroenterite/diagnóstico , Gastroenterite/microbiologia , Humanos , Incidência , Síndrome do Intestino Irritável/diagnóstico , Síndrome do Intestino Irritável/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Inquéritos e Questionários/estatística & dados numéricos , Redução de Peso , Adulto Jovem
13.
Environ Microbiol ; 20(9): 3278-3293, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30051571

RESUMO

Bacteriophage therapy is a commonly used treatment for Staphylococcus aureus infections in countries of the former Soviet Union, using both single phages and phage cocktails. The scarce data available on Eastern phage cocktails prompted an investigation into commercially-available Pyophage cocktails from two different manufacturers used to treat skin and wound infections. Comparison of the metagenomic composition of two Pyophage products from Georgia and Russia revealed substantial differences in phage-types targeting Escherichia, Enterococcus, Salmonella, Pseudomonas aeruginosa and Proteus, therefore indicating multiple strategies for composing phage cocktails against these bacterial pathogens. Closely-related Kayvirus-like Myoviruses were, however, a shared component against S. aureus within all products, except for the inclusion of a secondary S. aureus Podovirus in one Microgen cocktail. Metagenomic analysis also revealed the presence of several probable prophage sequences but detected no genetic safety risks in terms of virulence factors or antibiotic resistance genes. The safety of broad-spectrum cocktails was tested by comparing the effects of nasal and oral exposure to Eliava Pyophage, a monospecies counterpart and placebo in healthy human carriers of S. aureus. The lack of adverse effects in any treatment groups supports the clinical safety of S. aureus phages administered as a single phage or as phage cocktail.


Assuntos
Bacteriófagos/fisiologia , Portador Sadio/terapia , Myoviridae/fisiologia , Podoviridae/fisiologia , Infecções Estafilocócicas/terapia , Staphylococcus aureus/virologia , Adulto , Bacteriófagos/genética , Portador Sadio/microbiologia , Feminino , Georgia , República da Geórgia , Humanos , Masculino , Metagenoma , Myoviridae/genética , Terapia por Fagos , Podoviridae/genética , Pseudomonas aeruginosa/genética , Federação Russa , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/fisiologia , Adulto Jovem
14.
Environ Microbiol ; 20(6): 2256-2269, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29786169

RESUMO

We report streptococcal dysbiosis in acute diarrhoea irrespective of aetiology. Compared with 20 healthy local controls, 71 Bangladeshi children hospitalized with acute diarrhoea (AD) of viral, mixed viral/bacterial, bacterial and unknown aetiology showed a significantly decreased bacterial diversity with loss of pathways characteristic for the healthy distal colon microbiome (mannan degradation, methylerythritol phosphate and thiamin biosynthesis), an increased proportion of faecal streptococci belonging to the Streptococcus bovis and Streptococcus salivarius species complexes, and an increased level of E. coli-associated virulence genes. No enteropathogens could be attributed to a subgroup of patients. Elevated lytic coliphage DNA was detected in 2 out of 5 investigated enteroaggregative E. coli (EAEC)-infected patients. Streptococcal outgrowth in AD is discussed as a potential nutrient-driven consequence of glucose provided with oral rehydration solution.


Assuntos
Diarreia/etiologia , Diarreia/microbiologia , Streptococcus/isolamento & purificação , Bangladesh/epidemiologia , Estudos de Casos e Controles , Pré-Escolar , Diarreia/epidemiologia , Fezes/microbiologia , Feminino , Humanos , Lactente , Masculino , Microbiota , Virulência/genética
16.
Reprod Med Biol ; 16(2): 170-178, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-29259466

RESUMO

Aim: Endometriosis is defined as the presence of endometrial glandular and stromal cells outside of the uterine cavity. A previous study reported that microRNA (miR)-542-3p plays a critical role in eutopic endometrial decidualization. This study aims to clarify the potential role of miR-542-3p and the target gene, IGFBP-1 (insulin-like growth factor-binding protein 1), in the impairment of the decidualizing capacity of human ectopic endometrial stromal cells (HEcESCs). Methods: In vitro analysis of primary undifferentiated and decidualizing human eutopic endometrial stromal cells (HEuESCs) and HEcESCs was conducted. The primary HEuESCs or HEcESCs were expanded in culture and decidualized with 8-bromo-cyclic adenosine monophosphate (8-bromo-cAMP) and medroxyprogesterone acetate (MPA). Results: The morphological and biological differentiating capacities of the HEcESCs were markedly impaired. In contrast to the HEuESCs, the HEcESCs that were treated with the decidual stimulus retained the mesenchymal phenotype and capacity for migration. The down-regulation of miR-542-3p in the HEcESCs treatment with 8-bromo-cAMP and MPA was much weaker than that of the HEuESCs. High expression of miR-542-3p led to a significant decrease in the expression of IGFBP1 in the HEcESCs. Conclusion: Impairment of the differentiating capacity by the overexpression of miR-542-3p could influence the capacity for migration and invasion of endometriotic cells in an ectopic environment.

17.
Environ Microbiol ; 19(8): 2926-2934, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28474475

RESUMO

In 1890, Robert Koch has formulated postulates describing what criteria a parasite has to fulfil to qualify as an aetiological agent for an infectious disease. Since then Koch's postulates have experienced reformulations by nearly every generation of microbiologists reflecting new discoveries changing the understanding of infectious diseases pathogenesis. The latest addition to this discussion is the role of the host commensal microbiota in turning infections into disease. After an overview of the historical developments of the postulates, data on diarrhoea aetiology from Bangladesh with respect to Koch's postulates were analysed. In countries with a low environmental hygiene standard, some recognized bacterial enteropathogens appear as a necessary, but not sufficient condition for diarrhoea. The possibility emerges that the loss of a physiological commensal gut microbiota equilibrium ('dysbiosis') is an important co-factor for some bacterial pathogens to induce diarrhoea. Koch's hypothesis '1 pathogen + 1 host = 1 disease' is therefore better formulated as 'X (pathogen/s) + Y (local milieu) + Z (individual host susceptibility) = disease'.


Assuntos
Diarreia , Suscetibilidade a Doenças/fisiopatologia , Disbiose/microbiologia , Microbioma Gastrointestinal , Bangladesh , Diarreia/diagnóstico , Diarreia/microbiologia , Diarreia/fisiopatologia , Humanos , Higiene , Simbiose/fisiologia
18.
Environ Microbiol ; 19(1): 237-250, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27750388

RESUMO

A T4-like coliphage cocktail was given with different oral doses to healthy Bangladeshi children in a placebo-controlled randomized phase I safety trial. Fecal phage detection was oral dose dependent suggesting passive gut transit of coliphages through the gut. No adverse effects of phage application were seen clinically and by clinical chemistry. Similar results were obtained for a commercial phage preparation (Coliproteus from Microgen/Russia). By 16S rRNA gene sequencing, only a low degree of fecal microbiota conservation was seen in healthy children from Bangladesh who were sampled over a time interval of 7 days suggesting a substantial temporal fluctuation of the fecal microbiota composition. Microbiota variability was not associated with the age of the children or the presence of phage in the stool. Stool microbiota composition of Bangladeshi children resembled that found in children of other regions of the world. Marked variability in fecal microbiota composition was also seen in 71 pediatric diarrhea patients receiving only oral rehydration therapy and in 38 patients receiving coliphage preparations or placebo when sampled 1.2 or 4 days apart respectively. Temporal stability of the gut microbiota should be assessed in case-control studies involving children before associating fecal microbiota composition with health or disease phenotypes.


Assuntos
Bacteriófagos/fisiologia , Terapia Biológica , Diarreia/terapia , Infecções por Escherichia coli/terapia , Escherichia coli/virologia , Bangladesh , Terapia Biológica/efeitos adversos , Criança , Pré-Escolar , Diarreia/microbiologia , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Fezes/virologia , Feminino , Humanos , Masculino , RNA Ribossômico 16S
19.
EBioMedicine ; 4: 124-37, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26981577

RESUMO

BACKGROUND: Antibiotic resistance is rising in important bacterial pathogens. Phage therapy (PT), the use of bacterial viruses infecting the pathogen in a species-specific way, is a potential alternative. METHOD: T4-like coliphages or a commercial Russian coliphage product or placebo was orally given over 4 days to Bangladeshi children hospitalized with acute bacterial diarrhea. Safety of oral phage was assessed clinically and by functional tests; coliphage and Escherichia coli titers and enteropathogens were determined in stool and quantitative diarrhea parameters (stool output, stool frequency) were measured. Stool microbiota was studied by 16S rRNA gene sequencing; the genomes of four fecal Streptococcus isolates were sequenced. FINDINGS: No adverse events attributable to oral phage application were observed (primary safety outcome). Fecal coliphage was increased in treated over control children, but the titers did not show substantial intestinal phage replication (secondary microbiology outcome). 60% of the children suffered from a microbiologically proven E. coli diarrhea; the most frequent diagnosis was ETEC infections. Bacterial co-pathogens were also detected. Half of the patients contained phage-susceptible E. coli colonies in the stool. E. coli represented less than 5% of fecal bacteria. Stool ETEC titers showed only a short-lived peak and were otherwise close to the replication threshold determined for T4 phage in vitro. An interim analysis after the enrollment of 120 patients showed no amelioration in quantitative diarrhea parameter by PT over standard care (tertiary clinical outcome). Stool microbiota was characterized by an overgrowth with Streptococcus belonging to the Streptococcus gallolyticus and Streptococcus salivarius species groups, their abundance correlated with quantitative diarrhea outcome, but genome sequencing did not identify virulence genes. INTERPRETATION: Oral coliphages showed a safe gut transit in children, but failed to achieve intestinal amplification and to improve diarrhea outcome, possibly due to insufficient phage coverage and too low E. coli pathogen titers requiring higher oral phage doses. More knowledge is needed on in vivo phage-bacterium interaction and the role of E. coli in childhood diarrhea for successful PT. FUNDING: The study was supported by a grant from Nestlé Nutrition and Nestlé Health Science. The trial was registered with Identifier NCT00937274 at ClinicalTrials.gov.


Assuntos
Colífagos/patogenicidade , Diarreia/terapia , Infecções por Escherichia coli/terapia , Terapia por Fagos , Administração Oral , Adolescente , Bangladesh , Criança , Diarreia/microbiologia , Escherichia coli Enteropatogênica/virologia , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Masculino
20.
Int J Pediatr ; 2015: 387159, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26435718

RESUMO

The hematological and clinical chemistry profile for children aged 6 months to 5 years with acute diarrhoea was measured in a double blind clinical trial. Subjects were randomized to the study group (N = 44) given a bioactive polyphenol dietary supplement in oral rehydration solution (ORS) or to the control group (N = 41) given distilled water as a placebo in ORS twice daily for up to 4 days. All subjects received 10 mg zinc daily for the 4 days in the study. Venous blood was collected for complete blood count, electrolytes, liver function, and creatinine upon enrollment (baseline) and at the end of 4 days (end of study); mean values were compared by 95% confidence intervals. Overall, blood factors measured either remained the same over the 4 days or increased or decreased at the same levels between the two groups during the study period. All values were within accepted ranges for paediatric subjects except serum AST (SGOT), where the mean value of the study group approached the upper bound of the range on day 4 but was comparable to the value of the control group. Consumption of this supplement twice daily for 4 days is safe for children and infants.

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