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1.
Appl Environ Microbiol ; 88(23): e0155122, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36374022

RESUMO

Enterococcus faecalis is an important intestinal colonizing bacteria and can cause various tissue infections, including invasive blood infection (BI). The annual incidence of E. faecalis BI has been estimated to be ~4.5 per 100,000, with a fatality rate that can reach 20%. However, whether bacterial colonization or invasive infections are tissue based has not been thoroughly studied. In this study, we analyzed 537 clinical isolates from 7 different tissues to identify the key genomic elements that facilitate the colonization and invasive infection of E. faecalis. Comparative genomic analysis revealed that the BI E. faecalis isolates had the largest genome size but the lowest GC content, fsr quorum-sensing system genes were enriched in the BI E. faecalis, and the fsr gene cluster could enhance biofilm formation and serum resistance ability. Our findings also provide deep insight into the genomic differences between different tissue isolates, and the fsr quorum-sensing systems could be a key factor promoting E. faecalis invasion into the blood. IMPORTANCE First, we conducted an advanced study on the genomic differences between colonizing and infecting E. faecalis, which provides support and evidence for early and accurate diagnoses. Second, we discovered that fsr was significantly associated with blood infections, which also provides additional information for studies exploring the invasiveness of E. faecalis. Most importantly, we found that fsr played an important role in both biofilm formation and serum resistance ability in E. faecalis.


Assuntos
Enterococcus faecalis , Sepse , Humanos , Enterococcus faecalis/genética , Enterococcus faecalis/metabolismo , Regulação Bacteriana da Expressão Gênica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Percepção de Quorum/genética
2.
Clin Infect Dis ; 73(9): e2814-e2817, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33086379

RESUMO

Intrahost analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomic sequences identified 2 viral haplotypes comprised of 3 genetically linked mutations from the respiratory and intestinal tracts of a patient with coronavirus disease 2019. Spatiotemporal data suggest that this patient initially had dual infection of 2 SARS-CoV-2 variants, which subsequently redistributed into the 2 systems.


Assuntos
COVID-19 , SARS-CoV-2 , Genômica , Humanos , Sistema Respiratório
3.
Microbes Infect ; 24(6-7): 104977, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35413454

RESUMO

Interactions between the microbiota and immune system play a vital role in the host homeostasis. Increasing studies have investigated environmental perturbations affecting the microbiota. However, studies also are needed to model how an organ-specific immune response affects the microbiota to understand the dynamic changes between the immune system and microbiota. We constructed a murine Klebsiella oxytoca infection model, in which mice were gavaged with K. oxytoca, and the microbiota and immune responses of both the digestive tract and respiratory tract were compared for 1-2 weeks after infection. Metagenomic and cytokine analysis of the samples displayed a delayed colonization of K. oxytoca, but an early immune response in the respiratory tract, as compared with that in the digestive tract, suggested niche-specific characteristics of bacterial colonization and the corresponding immune response. Furthermore, we constructed an interaction map of K. oxytoca in both the digestive tract and respiratory tract that furthers our understanding of the host-microbe biology in K. oxytoca-infected hosts.


Assuntos
Infecções por Klebsiella , Microbiota , Animais , Citocinas , Imunidade , Infecções por Klebsiella/microbiologia , Klebsiella oxytoca/genética , Camundongos
4.
Cell Rep ; 41(6): 111609, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36351400

RESUMO

Bacterial type IV secretion systems (T4SSs) are the specific devices that mediate the dissemination of antibiotic resistant genes via horizontal gene transfer (HGT). Multi-drug-resistant Enterococcus faecalis (E. faecalis) represents a clinical public health threat because of its transferable plasmid with a functional plasmid-encoded (PE)-T4SS. Here, we report a chromosome-encoded (CE)-T4SS that exists in 40% of E. faecalis isolates. Compared with the PE-T4SS, CE-T4SS displays distinct characteristics in protein architecture and is capable of mediating large and genome-wide gene transfer in an imprecise manner. Reciprocal exchange of CE-T4SS- or PE-T4SS-associated origin of transfer (oriT) could disrupt HGT function, indicating that CE-T4SS is an independent system compared with PE-T4SS. Taken together, the CE-T4SS sheds light on the knowledge of HGT in gram-positive bacteria and triggers us to explore more evolutionary mechanisms in E. faecalis.


Assuntos
Enterococcus faecalis , Transferência Genética Horizontal , Enterococcus faecalis/genética , Enterococcus faecalis/metabolismo , Transferência Genética Horizontal/genética , Plasmídeos/genética , Sistemas de Secreção Tipo IV/metabolismo , Cromossomos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
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