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1.
Acta Vet Scand ; 62(1): 57, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028379

RESUMO

BACKGROUND: An overall increase in poaching of white rhinoceros results in captive breeding becoming a significant component of white rhinoceros conservation. However, this type of conservation comes with its own difficulties. When wildlife is captured, transported and/or confined to a boma environment, they are more predisposed to diseases caused by bacterial organisms such as spore forming Clostridium spp. A southern white rhinoceros (Ceratotherium simum simum) population on a captive bred farm was suspected to be affected by Clostridium infections. These endangered animals were apparently exposed to Clostridium spp., in the conservation area previously used for cattle farming. The rhinoceros population on the breeding operation property was vaccinated with a multi-component clostridial vaccine registered for use in cattle. Multiple indirect enzyme-linked immunosorbent assays (iELISAs) were developed in order to evaluate the serum antibody titres of these vaccinated animals. In evaluating vaccine efficacy, the gold standard mouse neutralization test (MNT) was not available and therefore iELISAs were developed for the detection of serum antibodies to C. perfringens type A (alpha toxin), C. chauvoei (whole cell), C. novyi (alpha toxin), C. septicum (alpha toxin) and C. sordellii (lethal toxin) in the white rhinoceros population using international reference sera of equine origin. Antibody titres against each clostridial antigen was evaluated in the vaccinated white rhinoceros population (n = 75). Analytical specificity showed slight cross-reactions for C. chauvoei and C. perfringens type A with the other antigens. Individual assay cut-off values were calculated with 95% confidence. Coefficient of variance (CV) values for both the international reference sera and in-house control sera across all the antigens were well below 16%, indicating good assay repeatability. This convenient and fast assay is suitable for monitoring humoral immune responses to clostridial antigens in vaccinated white rhinoceroses. RESULTS: Checkerboard titrations indicated optimal antigen and antibody concentrations to be used for each respective iELISA developed. Each titration set of the respective international reference and in-house control sera showed good repeatability with low standard deviations and coefficient of variance values calculated between repeats for each antigen. Individual assays proved repeatable and showed good analytical sensitivity and specificity. CONCLUSIONS: The developed iELISAs are able to evaluate antibody profiles of phospholipase C, C. chauvoei whole cells, TcnA, ATX, TcsL in white rhinoceros serum using international reference sera.


Assuntos
Antígenos de Bactérias/imunologia , Infecções por Clostridium/imunologia , Clostridium/fisiologia , Ensaio de Imunoadsorção Enzimática/veterinária , Imunidade Humoral , Perissodáctilos , Vacinação/veterinária , Animais , Animais de Zoológico , Ensaio de Imunoadsorção Enzimática/métodos
2.
Sheng Wu Gong Cheng Xue Bao ; 36(6): 1190-1197, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597068

RESUMO

Clostridia inhabiting in jiupei and pit mud plays key roles in the formation of flavour during the fermentation process of Luzhou-flavour baijiu. However, the differences of Clostridial communities between jiupei and pit mud remains unclear. Here, the species assembly, succession, and metabolic capacity of Clostridial communities between jiupei and pit mud were analysed by high-throughput sequencing and pure culture approaches. The ratio of Clostridial biomass to bacterial biomass in the pit mud was relatively stable (71.5%-91.2%) throughout the fermentation process. However, it varied widely in jiupei (0.9%-36.5%). The dominant Clostridial bacteria in jiupei were Clostridium (19.9%), Sedimentibacter (8.8%), and Hydrogenispora (7.2%), while Hydrogenispora (57.2%), Sedimentibacter (5.4%), and Caproiciproducens (4.9%) dominated in the Clostridial communities in pit mud. The structures of Clostridial community in pit mud and jiupei were significantly different (P=0.001) throughout fermentation. Isolated Clostridial strains showed different metabolic capacities of volatile fatty acids in pure culture. Spatial and temporal heterogeneity of Clostridial communities existed in the baijiu fermentation pit, which was closely related to the main flavour components of Luzhou-flavour baijiu.


Assuntos
Bebidas Alcoólicas , Clostridium , Microbiologia de Alimentos , Bebidas Alcoólicas/microbiologia , Bactérias/classificação , Bactérias/metabolismo , Clostridium/fisiologia , Ácidos Graxos Voláteis/metabolismo , Fermentação
3.
J Vet Diagn Invest ; 32(2): 175-183, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32081096

RESUMO

Gas gangrene is a necrotizing infection of subcutaneous tissue and muscle that affects mainly ruminants and horses, but also other domestic and wild mammals. Clostridium chauvoei, C. septicum, C. novyi type A, C. perfringens type A, and C. sordellii are the etiologic agents of this disease, acting singly or in combination. Although a presumptive diagnosis of gas gangrene can be established based on clinical history, clinical signs, and gross and microscopic changes, identification of the clostridia involved is required for confirmatory diagnosis. Gross and microscopic lesions are, however, highly suggestive of the disease. Although the disease has a worldwide distribution and can cause significant economic losses, the literature is limited mostly to case reports. Thus, we have reviewed the current knowledge of gas gangrene in mammals.


Assuntos
Animais Domésticos , Clostridium/fisiologia , Gangrena Gasosa/veterinária , Mamíferos , Animais , Infecções por Clostridium , Gangrena Gasosa/diagnóstico , Gangrena Gasosa/microbiologia
4.
J Vet Diagn Invest ; 32(2): 239-245, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32052697

RESUMO

Enteric disease in horses may be caused by a variety of microorganisms, including several clostridial species. Paeniclostridium sordellii (previously Clostridium sordellii) has been frequently associated with gas gangrene in humans and several animal species, including horses. However, its role in enteric diseases of animals has not been fully determined. We describe herein 7 cases of enteric disease in horses associated with P. sordellii infection. Grossly, the small and/or large intestines were necrotic, hemorrhagic, and edematous. Microscopically, there was severe mucosal necrosis and hemorrhage of the small and/or large intestine of all horses. P. sordellii was isolated and/or demonstrated by immunohistochemistry and/or PCR in the intestine of all horses. All other known causes of enteric disease in horses were ruled out in these 7 cases. P. sordellii should be considered among the differential diagnoses in cases of enteric disease in horses.


Assuntos
Infecções por Clostridium/veterinária , Clostridium/fisiologia , Enterocolite/veterinária , Doenças dos Cavalos/diagnóstico , Animais , Infecções por Clostridium/diagnóstico , Infecções por Clostridium/microbiologia , Clostridium sordellii , Diagnóstico Diferencial , Enterocolite/diagnóstico , Enterocolite/microbiologia , Doenças dos Cavalos/microbiologia , Cavalos , Intestino Grosso/patologia , Intestino Delgado/patologia
5.
J Vet Diagn Invest ; 32(2): 192-202, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31735127

RESUMO

Clostridia can cause hepatic damage in domestic livestock, and wild and laboratory animals. Clostridium novyi type B causes infectious necrotic hepatitis (INH) in sheep and less frequently in other species. Spores of C. novyi type B can be present in soil; after ingestion, they reach the liver via portal circulation where they persist in phagocytic cells. Following liver damage, frequently caused by migrating parasites, local anaerobic conditions allow germination of the clostridial spores and production of toxins. C. novyi type B alpha toxin causes necrotizing hepatitis and extensive edema, congestion, and hemorrhage in multiple organs. Clostridium haemolyticum causes bacillary hemoglobinuria (BH) in cattle, sheep, and rarely, horses. Beta toxin is the main virulence factor of C. haemolyticum, causing hepatic necrosis and hemolysis. Clostridium piliforme, the causal agent of Tyzzer disease (TD), is the only gram-negative and obligate intracellular pathogenic clostridia. TD occurs in multiple species, but it is more frequent in foals, lagomorphs, and laboratory animals. The mode of transmission is fecal-oral, with ingestion of spores from a fecal-contaminated environment. In affected animals, C. piliforme proliferates in the intestinal mucosa, resulting in necrosis, and then disseminates to the liver and other organs. Virulence factors for this microorganism have not been identified, to date. Given the peracute or acute nature of clostridial hepatitis in animals, treatment is rarely effective. However, INH and BH can be prevented, and should be controlled by vaccination and control of liver flukes. To date, no vaccine is available to prevent TD.


Assuntos
Clostridiales/fisiologia , Infecções por Clostridium/veterinária , Clostridium/fisiologia , Hemoglobinúria/veterinária , Hepatite Animal , Animais , Infecções por Clostridium/diagnóstico , Infecções por Clostridium/microbiologia , Infecções por Clostridium/prevenção & controle , Hemoglobinúria/diagnóstico , Hemoglobinúria/microbiologia , Hemoglobinúria/prevenção & controle , Hepatite Animal/diagnóstico , Hepatite Animal/microbiologia , Hepatite Animal/prevenção & controle , Necrose/diagnóstico , Necrose/microbiologia , Necrose/prevenção & controle , Necrose/veterinária
6.
Anaerobe ; 61: 102096, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31493499

RESUMO

An anaerobic, gram-positive, rod-shaped bacterium strain SP17-B1, isolated from dog saliva, was taxonomically characterized on the basis of phenotypic, chemotaxonomic, and genotypic characteristics. It was cultured in 4% (w/v) NaCl at a pH range of 5.0-8.0 (optimally at pH 7) and at 30°C-40 °C (optimally at 37 °C). Its major cellular fatty acids are C16:0 (36.3%), C17:0 cyclo (9.7%), C16:1ω9c (13.9%), and C18:1ω9c (10.7%), and its DNA guanine-cytosine content is 40.8 mol%. On the basis of the 16S rRNA gene sequence analysis, it was determined that the strain belonged to the genus Clostridium and was closely related to C. amygdalinum BR-10T (97.8%), C. saccharolyticum WM1T (97.8%), and C. celleracrescens DSM 5628T (97.7%). This strain showed a low level of DNA-DNA relatedness with the closely related strains, suggesting that it is a novel species in the genus Clostridium. Recent studies have demonstrated the production of succinic acid using Clostridium strains. Strain SP17-B1 produced 25.1 ±â€¯1.3 and 15.3 ±â€¯1.5 g/L of succinic acid from 40 g/L of glucose and 30 g/L of hevea wood waste hydrolysate (HH), respectively, after 24 h. When detoxified HH was used as a substrate, the lag phase was reduced and cell growth was enhanced by 7 fold (OD660 0.4-3.0) within 12 h. Detoxification using granular activated carbon may have reduced the levels of furfural and HMF without interfering with the amount of sugars in HH.


Assuntos
Clostridium/fisiologia , Fermentação , Hevea , Ácido Succínico/metabolismo , Resíduos , Madeira , Clostridium/química , Clostridium/classificação , Clostridium/isolamento & purificação , Genoma Bacteriano , Genômica/métodos , Genótipo , Técnicas de Genotipagem , Fenótipo , Filogenia
7.
Plant Dis ; 103(12): 3050-3056, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31642734

RESUMO

Flooding of sweetpotatoes in the field leads to development of soft rot on the storage roots while they remain submerged or on subsequent harvest and storage. Incidences of flooding after periods of intense rainy weather are on the rise in the southeastern United States, which is home to the majority of sweetpotato production in the nation. In an effort to characterize the causative agent(s) of this devastating disease, here we describe two distinct bacterial strains isolated from soft-rotted sweetpotato storage roots retrieved from an intentionally flooded field. Both of these anaerobic spore-forming isolates were identified as members of the genus Clostridium based on sequence similarity of multiple housekeeping genes, and both were confirmed to cause soft rot disease on sweetpotato and other vegetable crops. Despite these common features, the isolates were distinguishable by several phenotypic and biochemical properties, and phylogenetic analysis placed them in separate well-supported clades within the genus. Overall, our results demonstrate that multiple plant-pathogenic Clostridium species can cause soft rot disease on sweetpotato and suggest that a variety of other plant hosts may also be susceptible.


Assuntos
Clostridium , Ipomoea batatas , Raízes de Plantas , Clostridium/classificação , Clostridium/fisiologia , Genes Bacterianos/genética , Ipomoea batatas/microbiologia , Filogenia , Raízes de Plantas/microbiologia , Sudeste dos Estados Unidos
8.
Bioresour Technol ; 291: 121760, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31352165

RESUMO

A lab-scale stirred-tank bioreactor was reversibly retrofitted to a packed-bed and a trickle-bed biofilm reactor to study and compare the conversion of CO2/H2 with immobilised Clostridiumaceticum. The biofilm reactors were characterised and their functionality confirmed. Up to 8.6 g of C. aceticum were immobilised onto 300 g sintered ceramic carrier material, proving biofilm formation to be a robust means for cell retention of C. aceticum. Continuous CO2/H2-fermentation studies were performed with both biofilm reactor configurations as function of dilution rates, partial gas pressures and gas flow rates. The experiments showed that in the packed-bed biofilm reactor, the acetate space-time yield was independent of the dilution rate, because of low H2 gas-liquid mass transfer rates (≤17 mmol H2 L-1 h-1). The continuous operation of the trickle-bed biofilm reactor increased the gas-liquid mass transfer rates to up to 56 mmol H2 L-1 h-1. Consequently, the acetate space-time yield of up to 14 mmol acetate L-1 h-1 was improved 3-fold at hydrogen conversions of up to 96%.


Assuntos
Biofilmes , Reatores Biológicos , Dióxido de Carbono/metabolismo , Clostridium/fisiologia , Hidrogênio/metabolismo , Ácido Acético/metabolismo , Fermentação
9.
J Microbiol Biotechnol ; 29(7): 1083-1095, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31216841

RESUMO

Butyrate is known to play a significant role in energy metabolism and regulating genomic activities that influence rumen nutrition utilization and function. Thus, this study investigated the effects of an isolated butyrate-producing bacteria, Clostridium saccharobutylicum, in rumen butyrate production, fermentation parameters and microbial population in Holstein-Friesian cow. An isolated butyrate-producing bacterium from the ruminal fluid of a Holstein-Friesian cow was identified and characterized as Clostridium saccharobutylicum RNAL841125 using 16S rRNA gene sequencing and phylogenetic analyses. The bacterium was evaluated on its effects as supplement on in vitro rumen fermentation and microbial population. Supplementation with 106 CFU/ml Clostridium saccharobutylicum increased (p < 0.05) microbial crude protein, butyrate and total volatile fatty acids concentration but had no significant effect on NH3-N at 24 h incubation. Butyrate and total VFA concentrations were higher (p < 0.05) in supplementation with 106 CFU/ml Clostridium saccharobutylicum compared with control, with no differences observed for total gas production, NH3-N and propionate concentration. However, as the inclusion rate (CFU/ml) of C. saccharobutylicum was increased, reduction of rumen fermentation values was observed. Furthermore, butyrate-producing bacteria and Fibrobacter succinogenes population in the rumen increased in response with supplementation of C. saccharobutylicum, while no differences in the population in total bacteria, protozoa and fungi were observed among treatments. Overall, our study suggests that supplementation with 106 CFU/ml C. saccharobutylicum has the potential to improve ruminal fermentation through increased concentrations of butyrate and total volatile fatty acid, and enhanced population of butyrate-producing bacteria and cellulolytic bacteria F. succinogenes.


Assuntos
Butiratos/metabolismo , Clostridium/fisiologia , Suplementos Nutricionais , Fermentação , Microbioma Gastrointestinal , Rúmen/microbiologia , Ração Animal/análise , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bovinos/metabolismo , Bovinos/microbiologia , Clostridium/classificação , Clostridium/genética , Clostridium/metabolismo , Ácidos Graxos Voláteis/análise , Ácidos Graxos Voláteis/metabolismo , Filogenia , RNA Ribossômico 16S/genética
10.
Appl Environ Microbiol ; 85(15)2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126939

RESUMO

In polyextremophiles, i.e., microorganisms growing preferentially under multiple extremes, synergistic effects may allow growth when application of the same extremes alone would not. High hydrostatic pressure (HP) is rarely considered in studies of polyextremophiles, and its role in potentially enhancing tolerance to other extremes remains unclear. Here, we investigated the HP-temperature response in Clostridium paradoxum, a haloalkaliphilic moderately thermophilic endospore-forming bacterium, in the range of 50 to 70°C and 0.1 to 30 MPa. At ambient pressure, growth limits were extended from the previously reported 63°C to 70°C, defining C. paradoxum as an actual thermophile. Concomitant application of high HP and temperature compared to standard conditions (i.e., ambient pressure and 50°C) remarkably enhanced growth, with an optimum growth rate observed at 22 MPa and 60°C. HP distinctively defined C. paradoxum physiology, as at 22 MPa biomass, production increased by 75% and the release of fermentation products per cell decreased by >50% compared to ambient pressure. This metabolic modulation was apparently linked to an energy-preserving mechanism triggered by HP, involving a shift toward pyruvate as the preferred energy and carbon source. High HPs decreased cell damage, as determined by Syto9 and propidium iodide staining, despite no organic solute being accumulated intracellularly. A distinct reduction in carbon chain length of phospholipid fatty acids (PLFAs) and an increase in the amount of branched-chain PLFAs occurred at high HP. Our results describe a multifaceted, cause-and-effect relationship between HP and cell metabolism, stressing the importance of applying HP to define the boundaries for life under polyextreme conditions.IMPORTANCE Hydrostatic pressure (HP) is a fundamental parameter influencing biochemical reactions and cell physiology; however, it is less frequently applied than other factors, such as pH, temperature, and salinity, when studying polyextremophilic microorganisms. In particular, how HP affects microbial tolerance to other and multiple extremes remains unclear. Here, we show that under polyextreme conditions of high pH and temperature, Clostridium paradoxum demonstrates a moderately piezophilic nature as cultures grow to highest cell densities and most efficiently at a specific combination of temperature and HP. Our results highlight the importance of considering HP when exploring microbial physiology under extreme conditions and thus have implications for defining the limits for microbial life in nature and for optimizing industrial bioprocesses occurring under multiple extremes.


Assuntos
Membrana Celular/química , Clostridium/química , Clostridium/fisiologia , Metabolismo Energético , Pressão Hidrostática , Temperatura
11.
Bioresour Technol ; 284: 240-247, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30947138

RESUMO

The silage quality of alfalfa and stylo without or with 25%, 50% Moringa oleifera leaves (MOL) was investigated, and microbial community after ensiling was analysed. Results showed that the silage samples with MOL have lower butyric acid (0.50 vs 1.20, 0.60 vs 14.5 g/kg dry matter (DM) in alfalfa and stylo silage, respectively), ammonia-N (152 vs 262, 109 vs 180 g/kg total N) content and DM loss (7.71% vs 14.6%, 6.49% vs 18.9%). The addition of MOL also influenced the bacterial community distribution. The relative abundance of Enterobacter decreased from 58.6% to 30.5%, 17.4% to 9.1% in alfalfa and stylo silage when 50% MOL was added. Clostridium decreased from 23.5% to 0.2% in stylo silage, whereas Lactobacillus abundance increased from 30.4% to 49.9%, 41.8% to 86.0% in alfalfa and stylo silage, respectively. In conclusion, mixing with MOL could be a feasible way to improve the quality of alfalfa and stylo silage.


Assuntos
Fermentação , Medicago sativa/metabolismo , Microbiota , Moringa oleifera/metabolismo , Silagem , Amônia/metabolismo , Ácido Butírico/metabolismo , Clostridium/fisiologia , Lactobacillus/fisiologia , Folhas de Planta/metabolismo , Silagem/microbiologia
12.
Bioelectrochemistry ; 127: 94-103, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30771661

RESUMO

Biofilm-coated electrodes and outer cell membrane-mimicked electrodes were examined to verify an extracellular electron transfer mechanism using Marcus theory for a donor-acceptor electron transfer. Redox couple-bound membrane electrodes were prepared by impregnating redox coenzymes into Nafion films on carbon cloth electrodes. The electron transfer was believed to occur sequentially from acetate to nicotinamide adenine dinucleotide (NAD), c-type cytochrome, flavin mononucleotide (FMN) (or riboflavin (RBF)) and the anode substrate. Excellent polarisation and power density characteristics were contributed by the modification of the cathode with a high-surface-area ordered mesoporous carbon or a hollow core-mesoporous shell carbon. The maximum power density of the microbial fuel cell (MFC) could be improved by a factor of two mainly due to the accelerated electron consumption by modifying the cathode surfaces within three-dimensionally interconnected mesoporous carbon particles, and the anode was coated with a mixed culture of anaerobic bacteria.


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Acetatos/metabolismo , Biofilmes/crescimento & desenvolvimento , Carbono/química , Clostridium/enzimologia , Clostridium/fisiologia , Citocromos c/metabolismo , Eletricidade , Eletrodos , Transporte de Elétrons , Mononucleotídeo de Flavina/metabolismo , NAD/metabolismo , Oxirredução , Porosidade , Proteobactérias/enzimologia , Proteobactérias/fisiologia
13.
Drug Metab Dispos ; 47(2): 86-93, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30409838

RESUMO

Intestinal bacteria play an important role in bile acid metabolism and in the regulation of multiple host metabolic pathways (e.g., lipid and glucose homeostasis) through modulation of intestinal farnesoid X receptor (FXR) activity. Here, we examined the effect of berberine (BBR), a natural plant alkaloid, on intestinal bacteria using in vitro and in vivo models. In vivo, the metabolomic response and changes in mouse intestinal bacterial communities treated with BBR (100 mg/kg) for 5 days were assessed using NMR- and mass spectrometry-based metabolomics coupled with multivariate data analysis. Short-term BBR exposure altered intestinal bacteria by reducing Clostridium cluster XIVa and IV and their bile salt hydrolase (BSH) activity, which resulted in the accumulation of taurocholic acid (TCA). The accumulation of TCA was associated with activation of intestinal FXR, which can mediate bile acid, lipid, and glucose metabolism. In vitro, isolated mouse cecal bacteria were incubated with three doses of BBR (0.1, 1, and 10 mg/ml) for 4 hours in an anaerobic chamber. NMR-based metabolomics combined with flow cytometry was used to evaluate the direct physiologic and metabolic effect of BBR on the bacteria. In vitro, BBR exposure not only altered bacterial physiology but also changed bacterial community composition and function, especially reducing BSH-expressing bacteria like Clostridium spp. These data suggest that BBR directly affects bacteria to alter bile acid metabolism and activate FXR signaling. These data provide new insights into the link between intestinal bacteria, nuclear receptor signaling, and xenobiotics.


Assuntos
Berberina/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/metabolismo , Amidoidrolases/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Ceco/efeitos dos fármacos , Ceco/metabolismo , Ceco/microbiologia , Clostridium/efeitos dos fármacos , Clostridium/isolamento & purificação , Clostridium/fisiologia , Microbioma Gastrointestinal/fisiologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Masculino , Metabolômica/métodos , Camundongos , Camundongos Endogâmicos C57BL , Ácido Taurocólico/metabolismo
14.
Vet Res ; 49(1): 123, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30572930

RESUMO

Epizootic rabbit enteropathy (ERE) represents one of the most devastating diseases affecting rabbit farms. Previous studies showing transmissibility of disease symptoms through oral inoculation of intestinal contents from sick animals suggested a bacterial infectious origin for ERE. However, no etiological agent has been identified yet. On the other hand, ERE is associated with major changes in intestinal microbial communities, pinpointing dysbiosis as an alternative cause for the disease. To better understand the role of intestinal bacteria in ERE development, we have performed a prospective longitudinal study in which intestinal samples collected from the same animals before, during and after disease onset were analyzed using high-throughput sequencing. Changes in hundreds of bacterial groups were detected after the initiation of ERE. In contrast, before ERE onset, the microbiota from rabbits that developed ERE did not differ from those that remained healthy. Notably, an expansion of a single novel Clostridium species (Clostridium cuniculi) was detected the day of ERE onset. C. cuniculi encodes several putative toxins and it is phylogenetically related to the two well-characterized pathogens C. botulinum and C. perfringens. Our results are consistent with a bacterial infectious origin of ERE and discard dysbiosis as the initial trigger of the disease. Although experimental validation is required, results derived from sequencing analysis, propose a key role of C. cuniculi in ERE initiation.


Assuntos
Infecções por Clostridium/veterinária , Clostridium/fisiologia , Microbioma Gastrointestinal , Enteropatias/microbiologia , Intestinos/microbiologia , Coelhos , Animais , Clostridium/classificação , Infecções por Clostridium/microbiologia , Estudos Longitudinais , Estudos Prospectivos
15.
PLoS One ; 13(10): e0205055, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30278071

RESUMO

OBJECTIVES: Clostridium difficile infection is a public health concern. C. difficile was found in healthy human intestine as a member of Clostridium XI. Because soluble fermentable fiber ingestion affects intestinal microbiota, we used fiber-containing diets to determine the intestinal microbial condition that could reduce the presence of Clostridium XI. METHODS: Newly weaned male mice were assigned to three published diets: Control AIN-93G purified diet with only poorly fermented cellulose; Control plus 5% purified fermentable fiber inulin; Chow with wheat, soybean and corn that provide a mixture of unpurified dietary fibers. Methods were developed to quantify 24-hour fecal microbial load and microbial DNA density. The relative abundance of bacterial genera and the bacterial diversity were determined through 16S rRNA sequence-based fecal microbiota analysis. RESULTS: Mice adjusted food intake to maintain the same energy intake and body weight under these three moderate-fat (7% w:w) diets. Chow-feeding led to higher food intake but also higher 24-h fecal output. Chow-feeding and 1-8 wk ingestion of inulin-supplemented diet increased daily fecal microbial load and density along with lowering the prevalence of Clostridium XI to undetectable. Clostridium XI remained undetectable until 4 weeks after the termination of inulin-supplemented diet. Fermentable fiber intake did not consistently increase probiotic genera such as Bifidobacterium or Lactobacillus. Chow feeding, but not inulin supplementation, increased the bacterial diversity. CONCLUSIONS: Increase fecal microbial load/density upon fermentable fiber ingestion is associated with a lower and eventually undetectable presence of Clostridium XI. Higher bacterial diversity or abundance of particular genera is not apparently essential. Future studies are needed to see whether this observation can be translated into the reduction of C. difficile at the species level in at-risk populations.


Assuntos
Carga Bacteriana/efeitos dos fármacos , Clostridium/fisiologia , Fibras na Dieta/farmacologia , Suplementos Nutricionais , Fezes/microbiologia , Fermentação , Microbioma Gastrointestinal/efeitos dos fármacos , Animais , Clostridium/efeitos dos fármacos , Fibras na Dieta/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
16.
Cell Syst ; 7(3): 245-257.e7, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30195437

RESUMO

The diversity and number of species present within microbial communities create the potential for a multitude of interspecies metabolic interactions. Here, we develop, apply, and experimentally test a framework for inferring metabolic mechanisms associated with interspecies interactions. We perform pairwise growth and metabolome profiling of co-cultures of strains from a model mouse microbiota. We then apply our framework to dissect emergent metabolic behaviors that occur in co-culture. Based on one of the inferences from this framework, we identify and interrogate an amino acid cross-feeding interaction and validate that the proposed interaction leads to a growth benefit in vitro. Our results reveal the type and extent of emergent metabolic behavior in microbial communities composed of gut microbes. We focus on growth-modulating interactions, but the framework can be applied to interspecies interactions that modulate any phenotype of interest within microbial communities.


Assuntos
Clostridium/fisiologia , Eubacterium/fisiologia , Microbioma Gastrointestinal/fisiologia , Lactobacillus/fisiologia , Interações Microbianas , Animais , Técnicas de Cocultura , Simulação por Computador , Humanos , Redes e Vias Metabólicas , Metaboloma , Camundongos , Modelos Biológicos , Modelos Teóricos , Análise de Componente Principal
17.
J Proteome Res ; 17(9): 3075-3085, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-30109807

RESUMO

Bottom-up proteomics is increasingly being used to characterize unknown environmental, clinical, and forensic samples. Proteomics-based bacterial identification typically proceeds by tabulating peptide "hits" (i.e., confidently identified peptides) associated with the organisms in a database; those organisms with enough hits are declared present in the sample. This approach has proven to be successful in laboratory studies; however, important research gaps remain. First, the common-practice reliance on unique peptides for identification is susceptible to a phenomenon known as signal erosion. Second, no general guidelines are available for determining how many hits are needed to make a confident identification. These gaps inhibit the transition of this approach to real-world forensic samples where conditions vary and large databases may be needed. In this work, we propose statistical criteria that overcome the problem of signal erosion and can be applied regardless of the sample quality or data analysis pipeline. These criteria are straightforward, producing a p-value on the result of an organism or toxin identification. We test the proposed criteria on 919 LC-MS/MS data sets originating from 2 toxins and 32 bacterial strains acquired using multiple data collection platforms. Results reveal a > 95% correct species-level identification rate, demonstrating the effectiveness and robustness of proteomics-based organism/toxin identification.


Assuntos
Toxinas Bacterianas/isolamento & purificação , Ciências Forenses/métodos , Peptídeos/análise , Proteômica/estatística & dados numéricos , Bacillus/química , Bacillus/patogenicidade , Bacillus/fisiologia , Toxinas Bacterianas/química , Cromatografia Líquida , Clostridium/química , Clostridium/patogenicidade , Clostridium/fisiologia , Interpretação Estatística de Dados , Desulfovibrio/química , Desulfovibrio/patogenicidade , Desulfovibrio/fisiologia , Escherichia/química , Escherichia/patogenicidade , Escherichia/fisiologia , Ciências Forenses/instrumentação , Ciências Forenses/estatística & dados numéricos , Humanos , Peptídeos/química , Probabilidade , Proteômica/métodos , Pseudomonas/química , Pseudomonas/patogenicidade , Pseudomonas/fisiologia , Salmonella/química , Salmonella/patogenicidade , Salmonella/fisiologia , Sensibilidade e Especificidade , Shewanella/química , Shewanella/patogenicidade , Shewanella/fisiologia , Espectrometria de Massas em Tandem , Yersinia/química , Yersinia/patogenicidade , Yersinia/fisiologia
18.
Avian Dis ; 62(2): 241-246, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29944407

RESUMO

Focal duodenal necrosis (FDN) is an intestinal disease of egg-laying chickens, characterized by multifocal mucosal erosions in the duodenal loop and proximal jejunum. It is currently considered by the Association of Veterinarians in Egg Production and the United States Animal Health Association as one of the top five disease concerns of the table egg industry in the United States. Previous studies have associated this condition with Clostridium species. The purpose of this study was to investigate the epidemiologic characteristics of table egg layer flocks affected with FDN. An online questionnaire was distributed to commercial layer operations in different states in the United States. Layer farms that had diagnosed FDN within the past 12 mo were surveyed. The questionnaire had 45 questions about management, nutrition, housing, and methods for disease prevention and control. Thirty-seven surveys were sent and 21 were completed, which represents a response rate of 56.7%. The survey results showed the presence of FDN in five egg-layer genetic lines or breed crosses of different ages, with most cases reported between 30-39 wk of age. The pullets were cage-reared in all affected flocks and the majority of flocks in production were housed in traditional cages. Most of the FDN-affected flocks received more than 12 different feed formulations from pre-lay to 60 wk of age. Distiller's dried grain with solubles was a common ingredient added to the feed in the majority of affected flocks, and all flocks were provided with limestone as a calcium source for egg production. Most surveys reported that coccidiosis and roundworm parasitism were not problems in affected flocks in production; however, pests such as flies and rodents were reported as problems in most affected flocks. Additionally, most affected farms never washed feeders, cages, and houses before disinfection, which may not be sufficient to prevent the persistency and transmission of the causative agent of FDN. In conclusion, several management practices that have been associated with enteric disease, including clostridial-associated enteritis, were described by the majority of FDN-affected flocks. Additional studies are needed to determine if management and health practices identified in this survey represent risk factors for FDN.


Assuntos
Enteropatias/veterinária , Doenças das Aves Domésticas/epidemiologia , Adulto , Animais , Galinhas , Clostridium/fisiologia , Duodeno/microbiologia , Duodeno/patologia , Feminino , Humanos , Enteropatias/epidemiologia , Enteropatias/microbiologia , Masculino , Pessoa de Meia-Idade , Necrose , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/patologia , Fatores de Risco , Inquéritos e Questionários , Estados Unidos/epidemiologia
19.
Meat Sci ; 143: 69-73, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29715662

RESUMO

"Blown pack" spoilage is primarily caused by Clostridium estertheticum. The primary source of contamination is probably pelts, faeces and soil during opening cuts and de-hiding. Peroxyacetic acid (POAA) based fogs are commonly included in an abattoir's routine cleaning process. Hydrogen peroxide (H2O2) is a powerful oxidizing agent that penetrates microbe cell walls causing cell death. In this study, we compared the ability of H2O2 and OXYSAN ZS (POAA containing 1-hydroxyethylidine-1,1-diphosphonic acid as a stabilizer) in different formats to inactivate C. estertheticum spores. Hydrogen peroxide treatment using Phytagel™ gel as carrier was effective on fleece against both naturally contaminating microflora and C. estertheticum spores. This is the first time an antimicrobial treatment has been shown to inactivate C. estertheticum spores on such a complex and highly contaminated matrix. Both H2O2 and OXYSAN ZS treatments inactivated C. estertheticum spores on stainless steel indicating their potential use as an in-plant decontamination procedure or inclusion in routine in-process cleaning.


Assuntos
Antibacterianos/farmacologia , Clostridium/efeitos dos fármacos , Desinfetantes/farmacologia , Peróxido de Hidrogênio/farmacologia , Ácido Peracético/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Matadouros , Pelo Animal/efeitos dos fármacos , Pelo Animal/microbiologia , Animais , Antibacterianos/química , Carga Bacteriana/efeitos dos fármacos , Clostridium/crescimento & desenvolvimento , Clostridium/fisiologia , Desinfetantes/química , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Géis , Peróxido de Hidrogênio/química , Indústria de Embalagem de Carne/métodos , Viabilidade Microbiana/efeitos dos fármacos , Nova Zelândia , Ácido Peracético/química , Carneiro Doméstico , Esporos Bacterianos/crescimento & desenvolvimento , Esporos Bacterianos/fisiologia , Aço Inoxidável , Volatilização
20.
Chemosphere ; 203: 521-525, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29649694

RESUMO

The production of nanoparticles through biosynthesis is a reliable, non-toxic, and sustainable alternative to conventional chemical and physical methods of production. While noble metals, such as palladium, gold, and silver, have been formed via bioreduction, biologically-induced reduction of electroactive elements to a metallic state has not been reported previously. Herein, we report the reduction of an electroactive element, molybdenum, via microbial reduction using Clostridium pasteurianum. C. pasteurianum was able to reduce 88% of the added Mo6+ ions. The bioreduced molybdenum was shown to be metallically bonded in a prototypical crystal structure with an average particle size of 15 nm. C. pasteurianum was previously shown to degrade azo dyes using in situ formed Pd nanoparticles, but this study shows that in situ formed Mo particles also act as catalysts for degradation of azo dyes. C. pasteurianum cultures with the bioformed Mo nanoparticles were able completely degrade 155 µM methyl orange within 6 min, while controls with no Mo took 36 min. This research demonstrates, for the first time, that the bioreduction of active elements and formation of catalytic particles is achievable.


Assuntos
Compostos Azo/metabolismo , Clostridium/fisiologia , Molibdênio/metabolismo , Compostos Azo/química , Biocatálise , Nanopartículas Metálicas/química , Molibdênio/química
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