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1.
FEBS J ; 291(9): 1958-1973, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38700222

RESUMO

Serratia marcescens is an emerging health-threatening, gram-negative opportunistic pathogen associated with a wide variety of localized and life-threatening systemic infections. One of the most crucial virulence factors produced by S. marcescens is serratiopeptidase, a 50.2-kDa repeats-in-toxin (RTX) family broad-specificity zinc metalloprotease. RTX family proteins are functionally diverse exoproteins of gram-negative bacteria that exhibit calcium-dependent structural dynamicity and are secreted through a common type-1 secretion system (T1SS) machinery. To evaluate the impact of various divalent ligands on the folding and maturation of serratiopeptidase zymogen, the protein was purified and a series of structural and functional investigations were undertaken. The results indicate that calcium binding to the C-terminal RTX domain acts as a folding switch, triggering a disordered-to-ordered transition in the enzyme's conformation. Further, the auto-processing of the 16-amino acid N-terminal pro-peptide results in the maturation of the enzyme. The binding of calcium ions to serratiopeptidase causes a highly cooperative conformational transition in its structure, which is essential for the enzyme's activation and maturation. This conformational change is accompanied by an increase in solubility and enzymatic activity. For efficient secretion and to minimize intracellular toxicity, the enzyme needs to be in an unfolded extended form. The calcium-rich extracellular environment favors the folding and processing of zymogen into mature serratiopeptidase, i.e., the holo-form required by S. marcescens to establish infections and survive in different environmental niches.


Assuntos
Cálcio , Precursores Enzimáticos , Peptídeo Hidrolases , Dobramento de Proteína , Serratia marcescens , Cálcio/metabolismo , Serratia marcescens/enzimologia , Serratia marcescens/genética , Precursores Enzimáticos/metabolismo , Precursores Enzimáticos/química , Precursores Enzimáticos/genética , Metaloendopeptidases/química , Metaloendopeptidases/metabolismo , Metaloendopeptidases/genética , Modelos Moleculares , Conformação Proteica , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Ligação Proteica
2.
Org Biomol Chem ; 22(13): 2523-2538, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38456306

RESUMO

The decatungstate anion (W10O324-) appears to exhibit especially interesting properties as a photocatalyst. Because of its unique photocatalytic properties, it is now recognised as a promising tool in organic chemistry. This study examines recent advances in decatungstate chemistry, primarily concerned with synthetic and, to some degree, mechanistic challenges. In this short review we have selected to give a number of illustrative examples that demonstrate the various applications of decatungstate in the hydrogen atom transfer (HAT) process.

3.
RSC Adv ; 14(8): 5600, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38352673

RESUMO

[This corrects the article DOI: 10.1039/D3RA01364B.].

4.
RSC Adv ; 14(4): 2590-2601, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38226143

RESUMO

Photocatalysis has proven to be an effective approach for the production of reactive intermediates under moderate reaction conditions. The possibility for the green synthesis of high-value compounds using the synergy of photocatalysis and biocatalysis, benefiting from the selectivity of enzymes and the reactivity of photocatalysts, has drawn growing interest. Mechanistic investigations, substrate analyses, and photobiocatalytic chemical transformations will all be incorporated in this review. We seek to shed light on upcoming synthetic opportunities in the field by precisely describing mechanistically unique techniques in photobiocatalytic chemistry.

5.
Mol Divers ; 28(1): 61-71, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36609739

RESUMO

An efficient visible light mediated, eosin Y catalyzed direct C-H oxidative amination of benzoxazoles with secondary amines has been developed, which providing a straightforward, green, and environmentally benign access to a wide variety of substituted benzoxazole-2-amines under mild reaction conditions. The biological studies such as drug-likeness and molecular docking are also carried out on the molecule.


Assuntos
Aminas , Benzoxazóis , Aminação , Simulação de Acoplamento Molecular , Catálise , Estrutura Molecular , Metais , Luz
6.
Biochem Soc Trans ; 51(3): 971-981, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37334845

RESUMO

Proteins that are destined to enter the secretory pathway are synthesized on the rough endoplasmic reticulum (ER) and then translocated into the ER lumen, where they undergo posttranslational modifications, folding, and assembly. After passing a quality control system, the cargo proteins are packaged into coat protein complex II (COPII) vesicles to exit the ER. In metazoans, most COPII subunits have multiple paralogs, enabling COPII vesicles the flexibility to transport a diverse range of cargo. The cytoplasmic domains of transmembrane proteins can interact with SEC24 subunits of COPII to enter the ER exit sites. Some transmembrane proteins may also act as cargo receptors that bind soluble secretory proteins within the ER lumen, enabling them to enter COPII vesicles. The cytoplasmic domains of cargo receptors also contain coat protein complex I binding motifs that allow for their cycling back to the ER after unloading their cargo in the ER-Golgi intermediate compartment and cis-Golgi. Once unloaded, the soluble cargo proteins continue maturation through the Golgi before reaching their final destinations. This review provides an overview of receptor-mediated transport of secretory proteins from the ER to the Golgi, with a focus on the current understanding of two mammalian cargo receptors: the LMAN1-MCFD2 complex and SURF4, and their roles in human health and disease.


Assuntos
Retículo Endoplasmático , Complexo de Golgi , Animais , Humanos , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Membrana/metabolismo , Transporte Proteico , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Mamíferos/metabolismo
7.
J Biophotonics ; 16(8): e202200385, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37140081

RESUMO

Biopsy is the gold standard for cancer detection, however the surge in breast cancer cases has made manual haematoxylin and eosin stained histopathological image examination difficult. Automatic cancer diagnosis is vital for a healthy life. It allows fast diagnosis without specific skills. This research proposes an intelligent full-field polarization-sensitive optical coherence tomography (FF-PS-OCT) system for ex-vivo breast classification using ensemble model corroborated by technique for order preference by similarity to ideal solution (TOPSIS). 220 samples image were scanned using the FF-PS-OCT to extract the phase information. The multilevel ensemble classifier has 94.8% precision, 92.5% recall, 93.7% F-score and 82.3% Mathews correlation coefficient on the testing dataset. The developed ensemble model corroborated by TOPSIS, outperforms the single model in terms of performance metrics. The initial results indicate that the rapid, non-contact and label-free FF-PS-OCT imaging modality using birefringent information is beneficial for making interventional decisions by clinicians.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Mama , Biópsia , Birrefringência
8.
RSC Adv ; 13(16): 10958-10986, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-37033422

RESUMO

The field of photoredox catalysis has been transformed by the use of organic photocatalysts, which give access to re-activities that were previously only possible with transition-metal photocatalysts. Recent advancements in the use of an acridinium photocatalyst in organic synthesis are covered in this review. Both the late-stage functionalization of biorelevant molecules and the activation of inert chemical bonds are explored, with an emphasis on their mechanistic features.

9.
Pers Ubiquitous Comput ; 27(3): 675-687, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-33173450

RESUMO

The world is currently facing a pandemic called COVID-19 which has drastically changed our human lifestyle, affecting it badly. The lifestyle and the thought processes of every individual have changed with the current situation. This situation was unpredictable, and it contains a lot of uncertainties. In this paper, the authors have attempted to predict and analyze the disease along with its related issues to determine the maximum number of infected people, the speed of spread, and most importantly, its evaluation using a model-based parameter estimation method. In this research the Susceptible-Infectious-Recovered model with different conditions has been used for the analysis of COVID-19. The effects of lockdown, the light switch method, and parameter variations like contact ratio and reproduction number are also analyzed. The authors have attempted to study and predict the lockdown effect, particularly in India in terms of infected and recovered numbers, which show substantial improvement. A disease-free endemic stability analysis using Lyapunov and LaSalle's method is presented, and novel methods such as the convalescent plasma method and the Who Acquires Infection From Whom method are also discussed, as they are considered to be useful in flattening the curve of COVID-19.

10.
RSC Adv ; 12(54): 35221-35226, 2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36540212

RESUMO

A visible-light-mediated method for the construction of N-monoalkylated products from easily available benzamides and benzyl alcohol in the presence of eosin Y has been developed. The reaction proceeded smoothly, for a wide range of derivatives of benzamides and benzyl alcohols, to give the desired products in good to excellent yields. Biological studies, such as those on drug-likeness and molecular docking, are carried out on the molecules.

11.
Langmuir ; 38(49): 15077-15087, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36455281

RESUMO

Casein finds application as an eco-friendly adhesive for paper, wood, glass, etc. Casein being a protein can undergo conformational and microstructural changes during various processing steps involved in interfacial bonding. This study aims at understanding the multiscale contributions of these changes in casein to its adhesion to cellulose pressboards. Investigations spanning from molecular structure to macroscopic adhesion characteristics have been used in this work. The lap shear strength of casein bonded cellulose pressboards is found to increase with the increase in casein concentration. It was observed from Fourier transform infrared spectroscopy (FTIR) investigations along with microscopy and rheological studies that casein dispersions result in more α-helical conformations during the preconcentration process of casein dispersions. This results in increased hydrophobicity of the casein particles/aggregates, which in turn affects the wetting characteristics and the adhesion behavior. Casein compositions lacking α-helices were found to enhance the bonding strength of casein with cellulose. The present study shows that the adhesion between casein and microporous cellulose substrate has contributions at the multiscale originating from the polar-polar interactions of casein and cellulose molecules, conformational changes in the protein structure of casein during drying, microstructure of casein particles in the dispersion, and the microporous nature of the cellulose boards. These interactions at multiple scales can be tuned to suit different adhesive applications using casein.


Assuntos
Caseínas , Celulose , Caseínas/química , Celulose/química , Espectroscopia de Infravermelho com Transformada de Fourier , Interações Hidrofóbicas e Hidrofílicas , Reologia
12.
RSC Adv ; 12(49): 31891, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36383498

RESUMO

[This retracts the article DOI: 10.1039/C7RA05444K.].

13.
RSC Adv ; 12(46): 29826-29839, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36321108

RESUMO

Photoredox catalysis has been explored for chemical reactions by irradiation of photoactive catalysts with visible light, under mild and environmentally benign conditions. Furthermore, this methodology permits the activation of abundant chemicals into valuable products through novel mechanisms that are otherwise inaccessible. In this context, MoS2 has drawn attention due to its excellent solar spectral response and its notable electrical, optical, mechanical and magnetic properties. MoS2 has a number of characteristic properties like tunable band gap, enhanced absorption of visible light, a layered structure, efficient photon electron conversion, good photostability, non-toxic nature and quantum confinement effects that make it an ideal photocatalyst and co-catalyst for chemical transformations. Recently, MoS2 has gained synthetic utility in chemical transformations. In this review, we will discuss MoS2 properties, structure, synthesis techniques, and photochemistry along with modifications of MoS2 to enhance its photocatalytic activity with a focus on its applications and future challenges.

14.
mSphere ; 7(5): e0027022, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36073800

RESUMO

Human rotavirus (HRV) is a major cause of childhood diarrhea in developing countries where widespread malnutrition contributes to the decreased oral vaccine efficacy and increased prevalence of other enteric infections, which are major concerns for global health. Neonatal gnotobiotic (Gn) piglets closely resemble human infants in their anatomy, physiology, and outbred status, providing a unique model to investigate malnutrition, supplementations, and HRV infection. To understand the molecular signatures associated with immune enhancement and reduced diarrheal severity by Escherichia coli Nissle 1917 (EcN) and tryptophan (TRP), immunological responses and global nontargeted metabolomics and lipidomics approaches were investigated on the plasma and fecal contents of malnourished pigs transplanted with human infant fecal microbiota and infected with virulent (Vir) HRV. Overall, EcN + TRP combined (rather than individual supplement action) promoted greater and balanced immunoregulatory/immunostimulatory responses associated with greater protection against HRV infection and disease in malnourished humanized piglets. Moreover, EcN + TRP treatment upregulated the production of several metabolites with immunoregulatory/immunostimulatory properties: amino acids (N-acetylserotonin, methylacetoacetyl-CoA), lipids (gamma-butyrobetaine, eicosanoids, cholesterol-sulfate, sphinganine/phytosphingosine, leukotriene), organic compound (biliverdin), benzenoids (gentisic acid, aminobenzoic acid), and nucleotides (hypoxathine/inosine/xanthine, cytidine-5'-monophosphate). Additionally, the levels of several proinflammatory metabolites of organic compounds (adenosylhomocysteine, phenylacetylglycine, urobilinogen/coproporphyrinogen) and amino acid (phenylalanine) were reduced following EcN + TRP treatment. These results suggest that the EcN + TRP effects on reducing HRV diarrhea in neonatal Gn pigs were at least in part due to altered metabolites, those involved in lipid, amino acid, benzenoids, organic compounds, and nucleotide metabolism. Identification of these important mechanisms of EcN/TRP prevention of HRV diarrhea provides novel targets for therapeutics development. IMPORTANCE Human rotavirus (HRV) is the most common cause of viral gastroenteritis in children, especially in developing countries, where the efficacy of oral HRV vaccines is reduced. Escherichia coli Nissle 1917 (EcN) is used to treat enteric infections and ulcerative colitis while tryptophan (TRP) is a biomarker of malnutrition, and its supplementation can alleviate intestinal inflammation and normalize intestinal microbiota in malnourished hosts. Supplementation of EcN + TRP to malnourished humanized gnotobiotic piglets enhanced immune responses and resulted in greater protection against HRV infection and diarrhea. Moreover, EcN + TRP supplementation increased the levels of immunoregulatory/immunostimulatory metabolites while decreasing the production of proinflammatory metabolites in plasma and fecal samples. Profiling of immunoregulatory and proinflammatory biomarkers associated with HRV perturbations will aid in the identification of treatments against HRV and other enteric diseases in malnourished children.


Assuntos
Infecções por Escherichia coli , Transplante de Microbiota Fecal , Desnutrição , Infecções por Rotavirus , Triptofano , Animais , Humanos , Lactente , Aminobenzoatos , Biliverdina/metabolismo , Colesterol , Coenzima A/metabolismo , Coproporfirinogênios , Citidina/metabolismo , Diarreia , Escherichia coli/metabolismo , Vida Livre de Germes , Inosina/metabolismo , Lipídeos , Desnutrição/terapia , Desnutrição/complicações , Metaboloma , Microbiota , Nucleotídeos/metabolismo , Fenilalanina/metabolismo , Rotavirus , Sulfatos , Suínos , Triptofano/farmacologia , Urobilinogênio/metabolismo , Xantinas
15.
RSC Adv ; 12(28): 18245-18265, 2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35800311

RESUMO

Graphitic carbon nitride (g-C3N4) has emerged as a new research hotspot, attracting broad interdisciplinary attention in the form of metal-free and visible-light-responsive photocatalysts in the field of solar energy conversion and environmental remediation. These photocatalysts have evolved as attractive candidates due to their non-toxicity, chemical stability, efficient light absorption capacity in the visible and near-infrared regions, and adaptability as a platform for the fabrication of hybrid materials. This review mainly describes the latest advances in g-C3N4 photocatalysts for chemical transformations. In addition, the typical applications of g-C3N4-based photocatalysts involving organic transformation reactions are discussed (synthesis of heterocycles, hydrosulfonylation, hydration, oxygenation, arylation, coupling reactions, etc.).

16.
Microbiol Spectr ; 10(3): e0267421, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35579462

RESUMO

The impact of obesity on the human microbiota, immune maturation, and influenza virus infection has not been yet established in natural host animal models of influenza. In this study, gnotobiotic (Gn) pigs were colonized with human fecal microbiota (HFM) of obese (oHFM) or healthy lean (hHFM) children and infected at different periods (2-, 3-, and 5-weeks post-transplantation) using a zoonotic influenza virus strain. The infected oHFM pigs were characterized by lower levels of Firmicutes (Lactococcus, Lactobacillus, Turicibacter, and Streptococcus) and Actinobacteria (Bifidobacterium), which was associated with higher levels of Proteobacteria (Klebsiella), Bacteroidetes, and Verrucomicrobia (Akkermansia) compared with the infected hHFM group (P < 0.01). Furthermore, these genera significantly correlated with the expression of immune effectors, immune regulators, and inflammatory mediators, and displayed opposite trends between oHFM and hHFM groups (P < 0.01). The lymphoid and myeloid immune cell frequencies were differently modulated by the oHFM and hHFM colonization, especially apparent in the 5-weeks HFM colonized piglets. In addition, oHFM group had higher pro-inflammatory cytokines (IL-6, IL-12, TNF-α, and IFNγ) gene expression in the respiratory tract compared with the hHFM colonized pigs was detected. In conclusion, pigs colonized for longer duration, established oHFM increased the immune maturation favoring the activation of inflammatory mediators, however, the influenza virus load remained comparable with the hHFM group. Further, a longer duration of microbial colonization (5 weeks) may be required to reveal the impact of microbiome on the host immune maturation and susceptibility to influenza virus infection in the humanized Gn pig model. IMPORTANCE The diversity of gut microbiome of obese people differs markedly from that of lean healthy individuals which, in turn, influences the severity of inflammatory diseases because of differential maturation of immune system. The mouse model provides crucial insights into the mechanism(s) regulating the immune systems mediated by the gut microbiota but its applicability to humans is questionable because immune cells in mice are poorly activated in microbiota humanized mice. Several important strains of Bifidobacterium, Lactobacillus, and Clostridium fails to colonize the murine gut. Thus, understanding the role of certain important commensal gut bacterial species influences upon health and disease, a suitable large animal model like pig that supports the growth and colonization of most of the important human gut bacteria and possess comparable immunology and physiology to humans is beneficial to improve health.


Assuntos
Microbioma Gastrointestinal , Influenza Humana , Orthomyxoviridae , Obesidade Infantil , Animais , Bifidobacterium , Criança , Vida Livre de Germes , Humanos , Mediadores da Inflamação , Lactobacillus , Camundongos , Sistema Respiratório , Suínos
17.
Microbiol Spectr ; 10(3): e0028622, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35583333

RESUMO

Avian pathogenic Escherichia coli (APEC) associated with colibacillosis results in high morbidity and mortality, and severe economic losses to the poultry industry. APEC is a zoonotic pathogen and can infect humans through contaminated poultry products. Vaccination and antibiotic treatment are currently used to control APEC infections; however, the limited effect of vaccines and the emergence of antibiotic-resistant strains have necessitated the development of novel therapeutics. Here, we evaluated seven quorum sensing inhibitors (QSI) identified in our previous study, in APEC-infected chickens. QSIs were administered orally (~92 to 120 µg/bird) and chickens were challenged subcutaneously with APEC. Among them, QSI-5 conferred the best protection (100% reduction in mortality, 82% to 93% reduction in lesions [airsacculitis, perihepatitis, lung congestion, pericarditis] severity, and 5.2 to 6.1 logs reduction in APEC load). QSI-5 was further tested in chickens raised on built-up floor litter using an optimized dose (1 mg/L) in drinking water. QSI-5 reduced the mortality (88.4%), lesion severity (72.2%), and APEC load (2.8 logs) in chickens, which was better than the reduction observed with currently used antibiotic sulfadimethoxine (SDM; mortality 35.9%; lesion severity up to 36.9%; and APEC load up to 2.4 logs). QSI-5 was detected in chicken's blood after 0.5 h with no residues in muscle, liver, and kidney. QSI-5 increased the body weight gain with no effect on the feed conversion ratio and cecal microbiota of the chickens. Metabolomic studies revealed reduced levels of 5'-methylthioadenosine in QSI-5-treated chicken serum. In conclusion, QSI-5 displayed promising effects in chickens and thus, represents a novel anti-APEC therapeutic. IMPORTANCE Avian pathogenic Escherichia coli (APEC), a subgroup of ExPEC, is a zoonotic pathogen with public health importance. Quorum sensing is a mechanism that regulates virulence, biofilm formation, and pathogenesis in bacteria. Here, we identified a novel quorum sensing autoinducer-2 inhibitor, QSI-5, which showed higher anti-APEC efficacy in chickens compared to the currently used antibiotic, sulfadimethoxine at a much lower dose (up to 4,500 times). QSI-5 is readily absorbed with no residues in the tissues. QSI-5 also increased the chicken's body weight gain and did not impact the cecal microbiota composition. Overall, QSI-5 represents a promising lead compound for developing novel anti-virulence therapies with significant implications for treating APEC infections in chickens as well as other ExPEC associated infections in humans. Further identification of its target(s) and understanding the mechanism of action of QSI-5 in APEC will add to the future novel drug development efforts that can overcome the antimicrobial resistance problem.


Assuntos
Infecções por Escherichia coli , Escherichia coli Extraintestinal Patogênica , Doenças das Aves Domésticas , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Peso Corporal , Galinhas/microbiologia , Escherichia coli , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/microbiologia , Percepção de Quorum , Sulfadimetoxina/farmacologia , Sulfadimetoxina/uso terapêutico
18.
Probiotics Antimicrob Proteins ; 14(6): 1012-1028, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34458959

RESUMO

Avian pathogenic E. coli (APEC), an extra-intestinal pathogenic E. coli (ExPEC), causes colibacillosis in poultry and is also a potential foodborne zoonotic pathogen. Currently, APEC infections in poultry are controlled by antibiotic medication; however, the emergence of multi-drug-resistant APEC strains and increased restrictions on the use of antibiotics in food-producing animals necessitate the development of new antibiotic alternative therapies. Here, we tested the anti-APEC activity of multiple commensal and probiotic bacteria in an agar-well diffusion assay and identified Lacticaseibacillus rhamnosus GG and Bifidobacterium lactis Bb12 producing strong zone of inhibition against APEC. In co-culture assay, L. rhamnosus GG and B. lactis Bb12 completely inhibited the APEC growth by 24 h. Further investigation revealed that antibacterial product(s) in the culture supernatants of L. rhamnosus GG and B. lactis Bb12 were responsible for the anti-APEC activity. The analysis of culture supernatants using LC-MS/MS identified multiple novel bioactive peptides (VQAAQAGDTKPIEV, AFDNTDTSLDSTFKSA, VTDTSGKAGTTKISNV, and AESSDTNLVNAKAA) in addition to the production of lactic acid. The oral administration (108 CFU/chicken) of L. rhamnosus GG significantly (P < 0.001) reduced the colonization (~ 1.6 logs) of APEC in the cecum of chickens. Cecal microbiota analysis revealed that L. rhamnosus GG moderated the APEC-induced alterations of the microbial community in the cecum of chickens. Further, L. rhamnosus GG decreased (P < 0.05) the abundance of phylum Proteobacteria, particularly those belonging to Enterobacteriaceae (Escherichia-Shigella) family. These studies indicate that L. rhamnosus GG is a promising probiotic to control APEC infections in chickens. Further studies are needed to optimize the delivery of L. rhamnosus GG in feed or water and in conditions simulating the field to facilitate its development for commercial applications.


Assuntos
Bifidobacterium animalis , Infecções por Escherichia coli , Lacticaseibacillus rhamnosus , Doenças das Aves Domésticas , Probióticos , Animais , Escherichia coli , Galinhas , Cromatografia Líquida , Espectrometria de Massas em Tandem , Infecções por Escherichia coli/microbiologia , Probióticos/farmacologia , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/prevenção & controle , Doenças das Aves Domésticas/microbiologia , Antibacterianos/farmacologia , Aves Domésticas , Peptídeos/farmacologia
19.
PeerJ ; 9: e12120, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34616608

RESUMO

BACKGROUND: Cull sows are a unique population on swine farms, often representing poor producing or compromised animals, and even though recent studies have reported that the microbiome is associated with susceptibility to diseases, the microbiome of the cull sow population has not been explored. The main objective of this study was to investigate whether there were differences in fecal and upper respiratory tract microbiota composition for groups of sows of different health status (healthy, cull, and compromised/ clinical sows) and from different farms (1 to 6). METHODS: Six swine farms were visited once. Thirty individual fecal samples and nasal swabs were obtained at each farm and pooled by five across health status and farm. Samples underwent 16S rRNA gene amplicon sequencing and nasal and fecal microbiota were analyzed using QIIME2 v.2021.4. RESULTS: Overall, the diversity of the nasal microbiota was lower than the fecal microbiota (p < 0.01). No significant differences were found in fecal or nasal alpha diversity by sow's health status or by farm. There were significant differences in nasal microbial composition by farm and health status (PERMANOVA, p < 0.05), and in fecal microbiota by farm (PERMANOVA, p < 0.05), but not by health status. Lastly, at the L7 level, there was one differentially abundant taxa across farms for each nasal and fecal pooled samples. DISCUSSION: This study provided baseline information for nasal and fecal microbiota of sows under field conditions, and results suggest that farm of origin can affect microbial diversity and composition. Furthermore, sow's health status may have an impact on the nasal microbiota composition.

20.
Microbiol Spectr ; 9(2): e0000621, 2021 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-34468186

RESUMO

Avian pathogenic Escherichia coli (APEC), a subgroup of extraintestinal pathogenic E. coli (ExPEC), causes colibacillosis in chickens and is reportedly implicated in urinary tract infections and meningitis in humans. A major limitation for the current ExPEC antibiotic therapy is the development of resistance, and antibacterial drugs that can circumvent this problem are critically needed. Here, we evaluated eight novel membrane-affecting anti-APEC small molecule growth inhibitors (GIs), identified in our previous study, against APEC infection in chickens. Among the GIs tested, GI-7 (the most effective), when administered orally (1 mg/kg of body weight), reduced the mortality (41.7%), severity of lesions (62.9%), and APEC load (2.6 log) in chickens. Furthermore, GI-7 administration at an optimized dose (60 mg/liter) in drinking water also reduced the mortality (14.7%), severity of lesions (29.5%), and APEC load (2.2 log) in chickens. The abundances of Lactobacillus and oleate were increased in the cecum and serum, respectively, of GI-7-treated chickens. Pharmacokinetic analysis revealed that GI-7 was readily absorbed with minimal accumulation in the tissues. Earlier, we showed that GI-7 induced membrane blebbing and increased membrane permeability in APEC, suggesting an effect on the APEC membrane. Consistent with this finding, the expression of genes essential for maintaining outer membrane (OM) integrity was downregulated in GI-7-treated APEC. Furthermore, decreased levels of lipopolysaccharide (LPS) transport (Lpt) proteins and LPS were observed in GI-7-treated APEC. However, the mechanism of action of GI-7 currently remains unknown and needs further investigation. Our studies suggest that GI-7 represents a promising novel lead compound that can be developed to treat APEC infection in chickens and related human ExPEC infections. IMPORTANCE APEC is a subgroup of ExPEC, and genetic similarities of APEC with human ExPECs, including uropathogenic E. coli (UPEC) and neonatal meningitis E. coli (NMEC), have been reported. Our study identified a novel small molecule growth inhibitor, GI-7, effective in reducing APEC infection in chickens with an efficacy similar to that of the currently used antibiotic sulfadimethoxine, notably with an 8-times-lower dose. GI-7 affects the OM integrity and decreases the Lpt protein and LPS levels in APEC, an antibacterial mechanism that can overcome the antibiotic resistance problem. Overall, GI-7 represents a promising lead molecule/scaffold for the development of novel antibacterial therapies that could have profound implications for treating APEC infections in chickens, as well as human infections caused by ExPECs and other related Gram-negative bacteria. Further elucidation of the mechanism of action of GI-7 and identification of its target(s) in APEC will benefit future novel antibacterial development efforts.


Assuntos
Antibacterianos/farmacologia , Membrana Externa Bacteriana/patologia , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli Extraintestinal Patogênica/efeitos dos fármacos , Inibidores do Crescimento/farmacologia , Animais , Carga Bacteriana/efeitos dos fármacos , Membrana Externa Bacteriana/efeitos dos fármacos , Galinhas/microbiologia , Modelos Animais de Doenças , Escherichia coli Extraintestinal Patogênica/crescimento & desenvolvimento , Humanos , Doenças das Aves Domésticas/tratamento farmacológico , Doenças das Aves Domésticas/microbiologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia
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