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1.
J Virol ; 98(1): e0135923, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38084959

RESUMO

Phage therapy has shown great promise for the treatment of multidrug-resistant bacterial infections. However, the lack of a thorough and organized understanding of phage-body interactions has limited its clinical application. Here, we administered different purified phages (Salmonella phage SE_SZW1, Acinetobacter phage AB_SZ6, and Pseudomonas phage PA_LZ7) intravenously to healthy animals (rats and monkeys) to evaluate the phage-induced host responses and phage pharmacokinetics with different intravenous (IV) doses in healthy animals. The plasma and the organs were sampled after different IV doses to determine the phage biodistribution, phage-induced cytokines, and antibodies. The potential side effects of phages on animals were assessed. A non-compartment model revealed that the plasma phage titer gradually decreased over time following a single dose. Repeated doses resulted in a 2-3 Log10 decline of the plasma phage titer at 5 min compared to the first dose, regardless of the type of phage administered in rats. Host innate immune responses were activated including splenic enlargement following repeated doses. Phage-specific neutralization antibodies in animals receiving phages were detected. Similar results were obtained from monkeys. In conclusion, the mammalian bodies were well-tolerant to the administered phages. The animal responses to the phages and the phage biodistribution profiles could have a significant impact on the efficacy of phage therapy.IMPORTANCEPhage therapy has demonstrated potential in addressing multidrug-resistant bacterial infections. However, an insufficient understanding of phage-host interactions has impeded its broader clinical application. In our study, specific phages were administered intravenously (IV) to both rats and monkeys to elucidate phage-host interactions and evaluate phage pharmacokinetics (PK). Results revealed that with successive IV administrations, there was a decrease in plasma phage concentrations. Concurrently, these administrations elicited both innate and adaptive immune responses in the subjects. Notably, the observed immune responses and PK profiles exhibited variation contingent upon the phage type and the mammalian host. Despite these variations, the tested mammals exhibited a favorable tolerance to the IV-administered phages. This underscores the significance of comprehending these interactions for the optimization of phage therapy outcomes.


Assuntos
Infecções Bacterianas , Bacteriófagos , Terapia por Fagos , Animais , Humanos , Ratos , Infecções Bacterianas/terapia , Bacteriófagos/fisiologia , Mamíferos , Fagos de Pseudomonas , Distribuição Tecidual , Farmacorresistência Bacteriana Múltipla
2.
Nucleic Acids Res ; 51(15): 8005-8019, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37283060

RESUMO

Broad-host-range (BHR) plasmids in human gut bacteria are of considerable interest for their ability to mediate horizontal gene transfer (HGT) across large phylogenetic distance. However, the human gut plasmids, especially the BHR plasmids, remain largely unknown. Here, we identified the plasmids in the draft genomes of gut bacterial isolates from Chinese and American donors, resulting in 5372 plasmid-like clusters (PLCs), of which, 820 PLCs (comPLCs) were estimated with > 60% completeness genomes and only 155 (18.9%) were classified to known replicon types (n = 37). We observed that 175 comPLCs had a broad host range across distinct bacterial genera, of which, 71 were detected in at least two human populations of Chinese, American, Spanish, and Danish, and 13 were highly prevalent (>10%) in at least one human population. Haplotype analyses of two widespread PLCs demonstrated their spreading and evolutionary trajectory, suggesting frequent and recent exchanges of the BHR plasmids in environments. In conclusion, we obtained a large collection of plasmid sequences in human gut bacteria and demonstrated that a subset of the BHR plasmids can be transmitted globally, thus facilitating extensive HGT (e.g. antibiotic resistance genes) events. This study highlights the potential implications of the plasmids for global human health.


Assuntos
Microbioma Gastrointestinal , Humanos , Microbioma Gastrointestinal/genética , Filogenia , Especificidade de Hospedeiro , Plasmídeos/genética , Bactérias/genética , Transferência Genética Horizontal/genética
3.
Small ; : e2400771, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38751055

RESUMO

Periodontitis is the leading cause of adult tooth missing. Thorny bacterial biofilm and high reactive oxygen species (ROS) levels in tissue are key elements for the periodontitis process. It is meaningful to develop an advanced therapeutic system with sequential antibacterial/ antioxidant ability to meet the overall goals of periodontitis therapy. Herein, a dual-polymer functionalized melanin-AgNPs (P/D-MNP-Ag) with biofilm penetration, hydroxyapatite binding, and sequentially treatment ability are fabricated. Polymer enriched with 2-(Dimethylamino)ethyl methacrylate (D), can be protonated in an acid environment with enhanced positive charge, promoting penetration in biofilm. The other polymer is rich in phosphate group (P) and can chelate Ca2+, promoting the polymer to adhere to the hydroxyapatite surface. Melanin has good ROS scavenging and photothermal abilities, after in situ reduction Ag, melanin-AgNPs composite has sequentially transitioned between antibacterial and antioxidative ability due to heat and acid accelerated Ag+ release. The released Ag+ and heat have synergistic antibacterial effects for bacterial killing. With Ag+ consumption, the antioxidant ability of MNP recovers to scavenge ROS in the inflammatory area. When applied in the periodontitis model, P/D-MNP-Ag has good therapeutical effects to ablate biofilm, relieve inflammation state, and reduce alveolar bone loss. P/D-MNP-Ag with sequential treatment ability provides a reference for developing advanced oral biofilm eradication systems.

4.
Nucleic Acids Res ; 50(22): 13183-13197, 2022 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-36511873

RESUMO

Efforts have been made to reduce the genomes of living cells, but phage genome reduction remains challenging. It is of great interest to investigate whether genome reduction can make phages obtain new infectious properties. We developed a CRISPR/Cas9-based iterative phage genome reduction (CiPGr) approach and applied this to four distinct phages, thereby obtaining heterogeneous genome-reduced mutants. We isolated and sequenced 200 mutants with loss of up to 8-23% (3.3-35 kbp) of the original sequences. This allowed the identification of non-essential genes for phage propagation, although loss of these genes is mostly detrimental to phage fitness to various degrees. Notwithstanding this, mutants with higher infectious efficiency than their parental strains were characterized, indicating a trade-off between genome reduction and infectious fitness for phages. In conclusion, this study provides a foundation for future work to leverage the information generated by CiPGr in phage synthetic biology research.


Assuntos
Bacteriófagos , Edição de Genes , Virologia , Bacteriófagos/genética , Genoma Viral/genética , Virologia/métodos , Edição de Genes/métodos
5.
Anal Chem ; 94(32): 11124-11128, 2022 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-35920511

RESUMO

Herein, we report a sensitive scanning electrochemical microscopy (SECM) method based on the high transient current signals in carbon nanopipets (CNPs) under step potential waveforms. Taking advantage of the transient peak current, the approach curve can be conducted with very dilute (1 µM) or even no redox mediator and fitted by the scanning ion conductance microscopy (SICM) theory. In addition, a trace amount of electroactive species generated at the substrate can also be directly revealed from the transient current at the CNP tips. With the established feedback and generation/collection methods, we present the constant-height topography and electroactivity imaging of the substrates with only 1 µM K4Fe(CN)6. The developed new SECM method would allow the usage of CNPs to achieve both high sensitivity and spatial resolution with dilute or no redox mediator and thus find great potential applications in biological and electrocatalytic studies.


Assuntos
Carbono , Microscopia , Microscopia/métodos , Microscopia Eletroquímica de Varredura , Oxirredução
6.
Anal Chem ; 94(49): 16987-16991, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36449549

RESUMO

Conductive nanopipettes offer promising confined spaces to enable advanced electrochemical sensing applications in small spaces. Herein, a series of metal-decorated carbon nanopipettes (CNPs) were developed, in which Au, Ag, and Pt are modified at the inner walls of CNPs by a simple electrodeposition method. The fabricated tips show good sensing performances for a variety of important analytes, such as glucose, hydrogen peroxide, and chloride and hydrogen ions in biological and catalytic systems. This simple and effective approach can be further extended to prepare other functionalized nanopipette electrodes toward more versatile and powerful measurements in electrochemical sensing and imaging applications.


Assuntos
Carbono , Nanopartículas Metálicas , Técnicas Eletroquímicas/métodos , Eletrodos , Peróxido de Hidrogênio
7.
Anal Chem ; 93(48): 15821-15825, 2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34816713

RESUMO

The electrical double layer (EDL) at solid-liquid interfaces is key to interfacial transport and reaction processes and numerous emerging applications exploiting such processes. Herein, by studying hysteresis ion-transport processes in nanopipettes near charged substrates, we found the resulting cross-point potential (Vcp) to represent the surface potential of both nanopipettes and substrates. After the subtraction of Vcp in bulk solution, the remaining ΔVcp shows excellent exponential decay with respect to the separation distance from the substrates and agrees very well with the classical double-layer theory. The revealed new hysteresis ion transport in nanopipettes would provide a new way for the simple and direct EDL imaging of various interfaces of interest with nanoscale resolution in scanning ion conductance microscopy.

8.
J Virol ; 94(10)2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32132234

RESUMO

A novel lytic bacteriophage, ValSw3-3, which efficiently infects pathogenic strains of Vibrio alginolyticus, was isolated from sewage water and characterized by microbiological and in silico genomic analyses. Transmission electron microscopy indicated that ValSw3-3 has the morphology of siphoviruses. This phage can infect four species in the Vibrio genus and has a latent period of 15 min and a burst size of 95 ± 2 PFU/infected bacterium. Genome sequencing results show that ValSw3-3 has a 39,846-bp double-stranded DNA genome with a GC content of 43.1%. The similarity between the genome sequences of ValSw3-3 and those of other phages recorded in the GenBank database was below 50% (42%), suggesting that ValSw3-3 significantly differs from previously reported phages at the DNA level. Multiple genome comparisons and phylogenetic analysis based on the major capsid protein revealed that phage ValSw3-3 is grouped in a clade with five other phages, including Listonella phage phiHSIC (GenBank accession no. NC_006953.1), Vibrio phage P23 (MK097141.1), Vibrio phage pYD8-B (NC_021561.1), Vibrio phage 2E1 (KX507045.1), and Vibrio phage 12G5 (HQ632860.1), and is distinct from all known genera within the Siphoviridae family that have been ratified by the International Committee on Taxonomy of Viruses (ICTV). An in silico proteomic comparison of diverse phages from the Siphoviridae family supported this clustering result and suggested that ValSw3-3, phiHSIC, P23, pYD8-B, 2E1, and 12G5 should be classified as a novel genus cluster of Siphoviridae A subsequent analysis of core genes also revealed the common genes shared within this new cluster. Overall, these results provide a characterization of Vibrio phage ValSw3-3 and support our proposal of a new viral genus within the family SiphoviridaeIMPORTANCE Phage therapy has been considered a potential alternative to antibiotic therapy in treating bacterial infections. For controlling the vibriosis-causing pathogen Vibrio alginolyticus, well-documented phage candidates are still lacking. Here, we characterize a novel lytic Vibrio phage, ValSw3-3, based on its morphology, host range and infectivity, growth characteristics, stability under various conditions, and genomic features. Our results show that ValSw3-3 could be a potent candidate for phage therapy to treat V. alginolyticus infections due to its stronger infectivity and better pH and thermal stability than those of previously reported Vibrio phages. Moreover, genome sequence alignments, phylogenetic analysis, in silico proteomic comparison, and core gene analysis all support that this novel phage, ValSw3-3, and five unclassified phages form a clade distant from those of other known genera ratified by the ICTV. Thus, we propose a new viral genus within the Siphoviridae family to accommodate this clade, with ValSw3-3 as a representative member.


Assuntos
Genoma Viral , Genômica , Siphoviridae/genética , Vibrio alginolyticus/virologia , Composição de Bases , Proteínas do Capsídeo/classificação , DNA Viral , Especificidade de Hospedeiro , Microscopia Eletrônica de Transmissão , Filogenia , Proteômica , Esgotos/virologia , Siphoviridae/classificação , Siphoviridae/isolamento & purificação , Siphoviridae/fisiologia , Vibrio alginolyticus/genética , Sequenciamento Completo do Genoma
9.
Arch Virol ; 165(10): 2393-2396, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32719957

RESUMO

Pseudomonas phages PaGz-1 and PaZq-1, two new phages infecting Pseudomonas aeruginosa, were isolated from fresh water in Guangdong province, China. The genomes of these two phages consist of 93,975 bp and 94,315 bp and contain 175 and 172 open reading frames (ORFs), respectively. The genome sequences of PaGz-1 and PaZq-1 share 95.8% identity with a query coverage of 94%, suggesting that these two phages belong to two different species. Based on results of nucleotide sequence alignment, gene annotation, and phylogenetic analysis, we propose PaGz-1 and PaZq-1 as representative isolates of two species in the genus Pakpunavirus within the family Myoviridae.


Assuntos
Genoma Viral , Myoviridae/genética , Fases de Leitura Aberta , Filogenia , Fagos de Pseudomonas/genética , Pseudomonas aeruginosa/virologia , Sequência de Bases , China , Água Doce/microbiologia , Ontologia Genética , Anotação de Sequência Molecular , Myoviridae/classificação , Myoviridae/isolamento & purificação , Fagos de Pseudomonas/classificação , Fagos de Pseudomonas/isolamento & purificação , Pseudomonas aeruginosa/isolamento & purificação , Alinhamento de Sequência , Sequenciamento Completo do Genoma
10.
Arch Virol ; 164(5): 1475-1478, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30850860

RESUMO

Salmonella phages SenALZ1 and SenASZ3, two novel phages infecting Salmonella enterica, were isolated and analyzed. The genomes of these two phages consist of 154,811 and 157,630 base pairs (bp), with G+C contents of 44.56% and 44.74%, respectively. Fifty-nine of 199 open reading frames (ORFs) in the SenALZ1 genome, and 60 of the 204 in the SenASZ3 genome show similarity to reference sequences in the NCBI nr database that encode putative phage proteins with predicted functions. Based on the results of transmission electron microscopy (TEM) examination, complete genome sequence alignment, phylogenetic analysis, and gene annotation, we propose that these two phages are representative isolates of two new species of the genus Cba120virus, subfamily Cvivirinae, family Ackermannviridae.


Assuntos
Caudovirales , Fagos de Salmonella/isolamento & purificação , Salmonella enterica/virologia , Composição de Bases/genética , Sequência de Bases , Caudovirales/classificação , Caudovirales/genética , Caudovirales/isolamento & purificação , DNA Viral/genética , Genoma Viral/genética , Microscopia Eletrônica de Transmissão , Fases de Leitura Aberta/genética , Filogenia , Rios/virologia , Fagos de Salmonella/classificação , Fagos de Salmonella/genética , Análise de Sequência de DNA
11.
Antonie Van Leeuwenhoek ; 112(4): 641-649, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30374915

RESUMO

An aerobic, Gram-stain negative, rod-shaped and non-motile strain, BJC16-A31T, was isolated from the wetland soil sample taken from Daxing'anling, Heilongjiang, People's Republic of China. Strain BJC16-A31T was found to be oxidase- and catalase-positive, and produced light orange colonies on modified R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BJC16-A31T is closely related to Mucilaginibacter gotjawali SA3-7T with 96.54% sequence similarity and it formed a separate lineage in the genus Mucilaginibacter. Strain BJC16-A31T contained menaquinone-7 (MK-7) as the predominant isoprenoid quinine. Anteiso-C15:0, C16:0 and anteiso-C15:0 were the major fatty acids. The major polar lipids were phosphatidylethanolamine, six unidentified polar lipid, two unidentified aminophospholipids and one unidentified aminolipid. The genome is composed of a circular 5,301,339 bp chromosome with average G + C percentage of 42.25%. The Average Nucleotide Identity (ANI) between strain BJC16-A31T and M. gotjawali SA3-7T was 77.51%. Combined phenotypic, chemotaxonomic, phylogenetic and genomic characteristics support the conclusion that strain BJC16-A31T represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter xinganensis sp. nov. is proposed. The type strain is BJC16-A31T (= CGMCC 1.12728T = NBRC 110384T).


Assuntos
Bacteroidetes/isolamento & purificação , Fenantrenos/metabolismo , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Bacteroidetes/classificação , Bacteroidetes/genética , Bacteroidetes/metabolismo , Biodegradação Ambiental , China , DNA Bacteriano/genética , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Solo/química , Áreas Alagadas
12.
Arch Virol ; 163(7): 1985-1988, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29556775

RESUMO

In this study, two bacteriophage isolates, AhSzq-1 and AhSzw-1 that specifically infect Aeromonas hydrophila strain KT998822, were isolated from seawater and characterized. One-step growth curves showed that the latent period of AhSzq-1 and AhSzw-1 are 50 min and 60 min, respectively. The sequence similarities between AhSzq-1 and AhSzw-1 were 88% at the DNA and 83% at the protein level, suggesting that these two phages are representatives of two different species. The virion morphology, DNA genome size and terminal repeats of these two phages are similar to those of viruses classified as T5virus phages. Both phylogenetic analyses and proteomic comparison show that AhSzq-1 and AhSzw-1 group with members of the T5virus genus. We thus propose these two phages as representative isolates of two new species within the T5virus genus.


Assuntos
Aeromonas hydrophila/virologia , Bacteriófagos/genética , Genoma Viral , Água do Mar/virologia , Siphoviridae/genética , Aeromonas hydrophila/isolamento & purificação , Bacteriófagos/classificação , Bacteriófagos/crescimento & desenvolvimento , Bacteriófagos/isolamento & purificação , DNA Viral/genética , Genômica , Filogenia , Proteômica , Água do Mar/microbiologia , Análise de Sequência de DNA , Siphoviridae/classificação , Siphoviridae/crescimento & desenvolvimento , Siphoviridae/isolamento & purificação , Vírion/genética
13.
Arch Virol ; 163(11): 3195-3197, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30094514

RESUMO

AsXd-1, a bacteriophage that infects Aeromonas salmonicida, was isolated from the wastewater of a seafood market in Shenzhen, China. The 39,014-bp genome of this phage contains 52 open reading frames (ORFs), 30 of which were found to be homologous to reference sequences that putatively encode functional phage proteins. Nine out of the remaining 22 ORFs with unknown functions were unique to AsXd-1. Gene annotation suggests that AsXd-1 has both lysogenic and lytic life cycles. Furthermore, both phylogenetic analysis based on the large subunit of terminase and genome sequence comparisons show that AsXd-1 is closely related to phages belonging to the genus Hk97virus. We thus propose AsXd-1 as a new member of the genus Hk97virus within the family Siphoviridae.


Assuntos
Aeromonas/virologia , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Genoma Viral , Siphoviridae/classificação , Siphoviridae/isolamento & purificação , Bacteriófagos/classificação , Sequência de Bases , China , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA , Siphoviridae/genética , Proteínas Virais/genética
14.
J Virol ; 88(9): 4786-97, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24522917

RESUMO

UNLABELLED: Human papillomavirus (HPV) causes a number of neoplastic diseases in humans. Here, we show a complex normal HPV community in a cohort of 103 healthy human subjects, by metagenomics analysis of the shotgun sequencing data generated from the NIH Human Microbiome Project. The overall HPV prevalence was 68.9% and was highest in the skin (61.3%), followed by the vagina (41.5%), mouth (30%), and gut (17.3%). Of the 109 HPV types as well as additional unclassified types detected, most were undetectable by the widely used commercial kits targeting the vaginal/cervical HPV types. These HPVs likely represent true HPV infections rather than transitory exposure because of strong organ tropism and persistence of the same HPV types in repeat samples. Coexistence of multiple HPV types was found in 48.1% of the HPV-positive samples. Networking between HPV types, cooccurrence or exclusion, was detected in vaginal and skin samples. Large contigs assembled from short HPV reads were obtained from several samples, confirming their genuine HPV origin. This first large-scale survey of HPV using a shotgun sequencing approach yielded a comprehensive map of HPV infections among different body sites of healthy human subjects. IMPORTANCE: This nonbiased survey indicates that the HPV community in healthy humans is much more complex than previously defined by widely used kits that are target selective for only a few high- and low-risk HPV types for cervical cancer. The importance of nononcogenic viruses in a mixed HPV infection could be for stimulating or inhibiting a coexisting oncogenic virus via viral interference or immune cross-reaction. Knowledge gained from this study will be helpful to guide the designing of epidemiological and clinical studies in the future to determine the impact of nononcogenic HPV types on the outcome of HPV infections.


Assuntos
Voluntários Saudáveis , Microbiota , Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/virologia , Coinfecção/epidemiologia , Coinfecção/virologia , Feminino , Humanos , Metagenômica , Papillomaviridae/genética , Infecções por Papillomavirus/epidemiologia , Prevalência , Análise de Sequência de DNA
15.
World Neurosurg ; 187: e383-e398, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38657790

RESUMO

OBJECTIVE: Unilateral biportal endoscopic decompression (UBED) offers the advantages of minimal tissue damage, operational flexibility, and clear visualization, positioning it as an innovative and minimally invasive endoscopic technique. Nevertheless, the clinical evidence supporting the use of UBED in the treatment of degenerative lumbar diseases is limited and conflicting. METHODS: As of October 1, 2023, a comprehensive search was conducted across databases including Web of Science, PubMed, Embase, and the Cochrane Library to identify all published studies on minimally invasive UBED for the treatment of degenerative lumbar diseases. Data pertaining to patient demographics, fluoroscopy time, operative duration, intraoperative hemorrhage, hospitalization length, visual analog scale (VAS) score for back and leg pain, MacNab criteria, Oswestry Disability Index (ODI), and complication rates were extracted. The Newcastle-Ottawa scale was utilized to assess the quality. RESULTS: Twelve articles were included, involving 816 patients. The back VAS score (95% confidence interval [CI]: -0.09-0.07, P = 0.75), MacNab criteria (95% CI: 0.52-2.3, P = 0.82), fluoroscopy time (95% CI: -7.03 to -0.4, P = 0.08), and the incidence of complications (95% CI: 0.5-1.73, P = 0.82) were not significantly different, while the leg VAS score (95% CI: 0.01-0.18, P = 0.03), ODI score (95% CI: -1.03 to -0.09, P = 0.02), operation time (95% CI: 5.76-20.62, P = 0.0005), hospitalization length (95% CI: 0.41-2.76, P = 0.008), and intraoperative hemorrhage (95% CI: 21.92-72.44, P = 0.0003) were significantly different. CONCLUSIONS: UBED offers superiority in ODI, flexibility, and visual field clarity. Conversely, percutaneous endoscopic lumbar decompression presents advantages in terms of operation duration, blood loss, hospitalization length, and leg VAS score. These factors should be thoroughly considered when selecting a surgical approach.


Assuntos
Descompressão Cirúrgica , Degeneração do Disco Intervertebral , Vértebras Lombares , Humanos , Descompressão Cirúrgica/métodos , Vértebras Lombares/cirurgia , Degeneração do Disco Intervertebral/cirurgia , Resultado do Tratamento , Neuroendoscopia/métodos , Endoscopia/métodos , Duração da Cirurgia
16.
Mater Today Bio ; 26: 101091, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38800565

RESUMO

Oral biofilm is the leading cause of dental caries, which is difficult to completely eradicate because of the complicated biofilm structure. What's more, the hypoxia environment of biofilm and low water-solubility of conventional photosensitizers severely restrict the therapeutic effect of photodynamic therapy (PDT) for biofilm. Although conventional photosensitizers could be loaded in nanocarriers, it has reduced PDT effect because of aggregation-caused quenching (ACQ) phenomenon. In this study, we fabricated an oxygen self-sufficient nanodroplet (PFC/TPA@FNDs), which was composed of fluorinated-polymer (FP), perfluorocarbons (PFC) and an aggregation-induced emission (AIE) photosensitizer (Triphenylamine, TPA), to eradicate oral bacterial biofilm and whiten tooth. Fluorinated-polymer was synthesized by polymerizing (Dimethylamino)ethyl methacrylate, fluorinated monomer and 1-nonanol monomer. The nanodroplets could be protonated and behave strong positive charge under bacterial biofilm acid environment promoting nanodroplets deeply penetrating biofilm. More importantly, the nanodroplets had extremely high PFC and oxygen loading efficacy because of the hydrophobic affinity between fluorinated-polymer and PFC to relieve the hypoxia environment and enhance PDT effect. Additionally, compared with conventional ACQ photosensitizers loaded system, PFC/TPA@FNDs could behave superior PDT effect to ablate oral bacterial biofilm under light irradiation due to the unique AIE effect. In vivo caries animal model proved the nanodroplets could reduce dental caries area without damaging tooth structure. Ex vivo tooth whitening assay also confirmed the nanodroplets had similar tooth whitening ability compared with commercial tooth whitener H2O2, while did not disrupt the surface microstructure of tooth. This oxygen self-sufficient nanodroplet provides an alternative visual angle for oral biofilm eradication in biomedicine.

17.
Microbiol Spectr ; 12(1): e0188223, 2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38014983

RESUMO

IMPORTANCE: Phage therapy is gaining traction as an alternative to antibiotics due to the rise of multi-drug-resistant (MDR) bacteria. This study assessed the pharmacokinetics and safety of PA_LZ7, a phage targeting MDR Pseudomonas aeruginosa, in mice. After intravenous administration, the phage showed an exponential decay in plasma and its concentration dropped significantly within 24 h for all dosage groups. Although there was a temporary increase in certain plasma cytokines and spleen weight at higher dosages, no significant toxicity was observed. Therefore, PA_LZ7 shows potential as an effective and safe candidate for future phage therapy against MDR P. aeruginosa infections.


Assuntos
Bacteriófagos , Infecções por Pseudomonas , Fagos de Pseudomonas , Animais , Camundongos , Fagos de Pseudomonas/genética , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Infecções por Pseudomonas/terapia , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa
18.
Adv Sci (Weinh) ; : e2309972, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38937990

RESUMO

Klebsiella pneumoniae, a major clinical pathogen known for causing severe infections, is attracting heightened attention due to its escalating antibiotic resistance. Phages are emerging as a promising alternative to antibiotics; however, their specificity to particular hosts often restricts their use. In this study, a collection of 114 phages is obtained and subjected to analysis against 238 clinical K. pneumoniae strains, revealing a spectrum of lytic behaviors. A correlation between putative tail protein clusters and lysis patterns leads to the discovery of six receptor-binding protein (RBP) clusters that determine host capsule tropism. Significantly, RBPs with cross-capsular lysis capabilities are identified. The newly-identified RBPs provide a toolbox for customizing phages to target diverse capsular types. Building on the toolbox, the engineered phages with altered RBPs successfully shifted and broadened their host capsule tropism, setting the stage for tunable phage that offer a precise and flexible solution to combat K. pneumoniae infections.

19.
mSystems ; 8(5): e0064623, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37594262

RESUMO

IMPORTANCE: Salmonella infection is a significant threat to global public health, and the increasing prevalence of antibiotic resistance exacerbates the situation. Therefore, finding new and effective ways to combat this pathogen is essential. Phages are natural predators of bacteria and can be used as an alternative to antibiotics to kill specific bacteria, including drug-resistant strains. One significant limitation of using phages as antimicrobial agents is their low cellular uptake, which limits their effectiveness against intracellular bacterial infections. Therefore, finding ways to enhance phage uptake is crucial. Our study provides a straightforward strategy for displaying cell-penetrating peptides on non-model phages, offering a promising novel and effective therapeutic approach for treating intracellular and drug-resistant bacteria. This approach has the potential to address the global challenge of antibiotic resistance and improve public health outcomes.


Assuntos
Infecções Bacterianas , Bacteriófagos , Peptídeos Penetradores de Células , Humanos , Infecções Bacterianas/terapia , Resistência Microbiana a Medicamentos , Antibacterianos/farmacologia
20.
Plant Physiol Biochem ; 199: 107710, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37087887

RESUMO

Radish is an economical cool-season root vegetable crop worldwide. Heat shock protein 70 (HSP70) plays indispensable roles in plant growth, development and abiotic stress responses. Nevertheless, little information is available regarding the identification and functional characterization of HSP70 gene family in radish. Herein, a total of 34 RsHSP70 genes were identified at the radish genome level, among which nine and 25 RsHSP70s were classified into the HSP110/SSE and DnaK subfamilies, respectively. RNA-seq analysis revealed that some RsHSP70 genes had differential expression profile in radish leaf, root, stamen and pistil. A range of RsHSP70 genes exhibited differential expression under several abiotic stresses such as heat, salt and heavy metals. Intriguingly, the expression of four RsHSP70 genes (RsHSP70-7, RsHSP70-12, RsHSP70-20 and RsHSP70-22) was dramatically up-regulated under heat stress (HS). RT-qPCR and transient LUC reporter assay indicated that both the expression and promoter activity of RsHSP70-20 was strongly induced by HS. Notably, overexpression of RsHSP70-20 significantly enhanced thermotolerance by decreasing reactive oxygen species and promoting proline accumulation in radish, whereas its knock-down plants exhibited increased thermosensitivity, indicating that RsHSP70-20 positively regulate HS response in radish. These results would provide valuable information to decipher the molecular basis of RsHSP70-mediated thermotolerance in radish.


Assuntos
Raphanus , Raphanus/genética , Raphanus/metabolismo , Resposta ao Choque Térmico , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas
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