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1.
Proc Natl Acad Sci U S A ; 120(1): e2212175120, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36574699

RESUMEN

The ability of bacterial pathogens to adapt to host niches is driven by the carriage and regulation of genes that benefit pathogenic lifestyles. Genes that encode virulence or fitness-enhancing factors must be regulated in response to changing host environments to allow rapid response to challenges presented by the host. Furthermore, this process can be controlled by preexisting transcription factors (TFs) that acquire new roles in tailoring regulatory networks, specifically in pathogens. However, the mechanisms underlying this process are poorly understood. The highly conserved Escherichia coli TF YhaJ exhibits distinct genome-binding dynamics and transcriptome control in pathotypes that occupy different host niches, such as uropathogenic E. coli (UPEC). Here, we report that this important regulator is required for UPEC systemic survival during murine bloodstream infection (BSI). This advantage is gained through the coordinated regulation of a small regulon comprised of both virulence and metabolic genes. YhaJ coordinates activation of both Type 1 and F1C fimbriae, as well as biosynthesis of the amino acid tryptophan, by both direct and indirect mechanisms. Deletion of yhaJ or the individual genes under its control leads to attenuated survival during BSI. Furthermore, all three systems are up-regulated in response to signals derived from serum or systemic host tissue, but not urine, suggesting a niche-specific regulatory trigger that enhances UPEC fitness via pleiotropic mechanisms. Collectively, our results identify YhaJ as a pathotype-specific regulatory aide, enhancing the expression of key genes that are collectively required for UPEC bloodstream pathogenesis.


Asunto(s)
Infecciones por Escherichia coli , Proteínas de Escherichia coli , Sepsis , Infecciones Urinarias , Escherichia coli Uropatógena , Animales , Ratones , Escherichia coli/genética , Escherichia coli/metabolismo , Infecciones Urinarias/microbiología , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Infecciones por Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Factores de Virulencia/genética , Escherichia coli Uropatógena/genética , Regulación Bacteriana de la Expresión Génica
2.
Infect Immun ; 92(6): e0013224, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38700334

RESUMEN

Adherent and invasive Escherichia coli (AIEC) is a pathobiont that is involved in the onset and exacerbation of Crohn's disease. Although the inducible expression of virulence traits is a critical step for AIEC colonization in the host, the mechanism underlying AIEC colonization remains largely unclear. We here showed that the two-component signal transduction system CpxRA contributes to AIEC gut competitive colonization by activating type 1 fimbriae expression. CpxRA from AIEC strain LF82 functioned as a transcriptional regulator, as evidenced by our finding that an isogenic cpxRA mutant exhibits reduced expression of cpxP, a known regulon gene. Transcription levels of cpxP in LF82 increased in response to envelope stress, such as exposure to antimicrobials compromising the bacterial membrane, whereas the cpxRA mutant did not exhibit this response. Furthermore, we found that the cpxRA mutant exhibits less invasiveness into host cells than LF82, primarily due to reduced expression of the type 1 fimbriae. Finally, we found that the cpxRA mutant is impaired in gut competitive colonization in a mouse model. The colonization defects were reversed by the introduction of a plasmid encoding the cpxRA gene or expressing the type 1 fimbriae. Our findings indicate that modulating CpxRA activity could be a promising approach to regulating AIEC-involved Crohn's disease.


Asunto(s)
Adhesión Bacteriana , Modelos Animales de Enfermedad , Células Epiteliales , Infecciones por Escherichia coli , Escherichia coli , Fimbrias Bacterianas , Regulación Bacteriana de la Expresión Génica , Animales , Ratones , Fimbrias Bacterianas/metabolismo , Fimbrias Bacterianas/genética , Escherichia coli/genética , Escherichia coli/patogenicidad , Células Epiteliales/microbiología , Infecciones por Escherichia coli/microbiología , Adhesión Bacteriana/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Humanos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Virulencia/genética , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Intestinos/microbiología , Femenino
3.
BMC Genomics ; 25(1): 609, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886681

RESUMEN

Adhesins are crucial factors in the virulence of bacterial pathogens such as Escherichia coli. However, to date no resources have been dedicated to the detailed analysis of E. coli adhesins. Here, we provide adhesiomeR software that enables characterization of the complete adhesin repertoire, termed the adhesiome. AdhesiomeR incorporates the most comprehensive database of E. coli adhesins and facilitates an extensive analysis of adhesiome. We demonstrate that adhesiomeR achieves 98% accuracy when compared with experimental analyses. Based on analysis of 15,000 E. coli genomes, we define novel adhesiome profiles and clusters, providing a nomenclature for a unified comparison of E. coli adhesiomes.


Asunto(s)
Adhesinas de Escherichia coli , Escherichia coli , Programas Informáticos , Adhesinas de Escherichia coli/genética , Adhesinas de Escherichia coli/metabolismo , Escherichia coli/genética , Escherichia coli/clasificación , Genoma Bacteriano , Biología Computacional/métodos
4.
Mol Microbiol ; 120(1): 1-7, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36331175

RESUMEN

Bacteria deal with an unpredictable, and often hostile, environment by being unpredictable themselves. This article will link some contributions made by variable DNA topology and nucleoid-associated proteins to the generation of stochasticity in bacterial gene expression and describe how the associated mechanistic insights can elucidate the means by which diversity in antibody and neuronal cell development might be produced in humans and other higher organisms. The focus here will not be on mutation; instead, the article will address epigenetic effects on gene expression brought about by the modulation of topoisomerase activity in both prokaryotes and eukaryotes.


Asunto(s)
Proteínas de Unión al ADN , ADN , Humanos , Proteínas de Unión al ADN/metabolismo , ADN/genética , Mutación
5.
Small ; 20(26): e2310149, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38233200

RESUMEN

Bioinspired nanotopography is a promising approach to generate antimicrobial surfaces to combat implant-associated infection. Despite efforts to develop bactericidal 1D structures, the antibacterial capacity of 2D structures and their mechanism of action remains uncertain. Here, hydrothermal synthesis is utilized to generate two 2D nanoflake surfaces on titanium (Ti) substrates and investigate the physiological effects of nanoflakes on bacteria. The nanoflakes impair the attachment and growth of Escherichia coli and trigger the accumulation of intracellular reactive oxygen species (ROS), potentially contributing to the killing of adherent bacteria. E. coli surface appendages type-1 fimbriae and flagella are not implicated in the nanoflake-mediated modulation of bacterial attachment but do influence the bactericidal effects of nanoflakes. An E. coli ΔfimA mutant lacking type-1 fimbriae is more susceptible to the bactericidal effects of nanoflakes than the parent strain, while E. coli cells lacking flagella (ΔfliC) are more resistant. The results suggest that type-1 fimbriae confer a cushioning effect that protects bacteria upon initial contact with the nanoflake surface, while flagella-mediated motility can lead to elevated membrane abrasion. This finding offers a better understanding of the antibacterial properties of nanoflake structures that can be applied to the design of antimicrobial surfaces for future medical applications.


Asunto(s)
Escherichia coli , Propiedades de Superficie , Titanio , Titanio/química , Titanio/farmacología , Escherichia coli/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Especies Reactivas de Oxígeno/metabolismo , Nanoestructuras/química , Adhesión Bacteriana/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Antiinfecciosos/farmacología , Antiinfecciosos/química , Fimbrias Bacterianas/efectos de los fármacos , Fimbrias Bacterianas/metabolismo
6.
Arch Microbiol ; 206(9): 373, 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-39127787

RESUMEN

Adherence to both cellular and abiotic surfaces is a crucial step in the interaction of bacterial pathogens and commensals with their hosts. Bacterial surface structures known as fimbriae or pili play a fundamental role in the early colonization stages by providing specificity or tropism. Among the various fimbrial families, the chaperone-usher family has been extensively studied due to its ubiquity, diversity, and abundance. This family is named after the components that facilitate their biogenesis. Type 1 fimbria and P pilus, two chaperone-usher fimbriae associated with urinary tract infections, have been thoroughly investigated and serve as prototypes that have laid the foundations for understanding the biogenesis of this fimbrial family. Additionally, the study of the mechanisms regulating their expression has also been a subject of great interest, revealing that the regulation of the expression of the genes encoding these structures is a complex and diverse process, involving both common global regulators and those specific to each operon.


Asunto(s)
Proteínas Fimbrias , Fimbrias Bacterianas , Regulación Bacteriana de la Expresión Génica , Chaperonas Moleculares , Fimbrias Bacterianas/metabolismo , Fimbrias Bacterianas/genética , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Proteínas Fimbrias/genética , Proteínas Fimbrias/metabolismo , Adhesión Bacteriana , Operón
7.
Arch Microbiol ; 206(3): 90, 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38315222

RESUMEN

Trueperella pyogenes (T. pyogenes) is an opportunistic pathogen that causes infertility, mastitis, and metritis in animals. T. pyogenes is also a zoonotic disease and is considered an economic loss agent in the livestock industry. Therefore, vaccine development is necessary. Using an immunoinformatics approach, this study aimed to construct a multi-epitope vaccine against T. pyogenes. The collagen adhesion protein, fimbriae, and pyolysin (PLO) sequences were initially retrieved. The HTL, CTL, and B cell epitopes were predicted. The vaccine was designed by binding these epitopes with linkers. To increase vaccine immunogenicity, profilin was added to the N-terminal of the vaccine construct. The antigenic features and safety of the vaccine model were investigated. Docking, molecular dynamics simulation of the vaccine with immune receptors, and immunological simulation were used to evaluate the vaccine's efficacy. The vaccine's sequence was then optimized for cloning. The vaccine construct was designed based on 18 epitopes of T. pyogenes. The computational tools validated the vaccine as non-allergenic, non-toxic, hydrophilic, and stable at different temperatures with acceptable antigenic features. The vaccine model had good affinity and stability to bovine TLR2, 4, and 5 as well as stimulation of IgM, IgG, IL-2, IFN-γ, and Th1 responses. This vaccine also increased long-lived memory cells, dendritic cells, and macrophage population. In addition, codon optimization was done and cloned in the E. coli K12 expression vector (pET-28a). For the first time, this study introduced a novel multi-epitope vaccine candidate based on collagen adhesion protein, fimbriae, and PLO of T. pyogenes. It is expected this vaccine stimulates an effective immune response to prevent T. pyogenes infection.


Asunto(s)
Proteínas Bacterianas , Toxinas Bacterianas , Proteínas Hemolisinas , Inmunoinformática , Vacunas , Femenino , Animales , Bovinos , Escherichia coli/metabolismo , Epítopos de Linfocito B/genética , Epítopos de Linfocito B/química , Colágeno , Biología Computacional
8.
Food Microbiol ; 121: 104519, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38637081

RESUMEN

Currently, fresh, unprocessed food has become a relevant element of the chain of transmission of enteropathogenic infections. To survive on a plant surface and further spread the infections, pathogens like Salmonella have to attach stably to the leaf surface. Adhesion, driven by various virulence factors, including the most abundant fim operon encoding type 1 fimbriae, is usually an initial step of infection, preventing physical removal of the pathogen. Adhesion properties of Salmonella's type 1 fimbriae and its FimH adhesin were investigated intensively in the past. However, there is a lack of knowledge regarding its role in interaction with plant cells. Understanding the mechanisms and structures involved in such interaction may facilitate efforts to decrease the risk of contamination and increase fresh food safety. Here, we applied Salmonella genome site-directed mutagenesis, adhesion assays, protein-protein interactions, and biophysics methods based on surface plasmon resonance to unravel the role of FimH adhesin in interaction with spinach leaves. We show that FimH is at least partially responsible for Salmonella binding to spinach leaves, and this interaction occurs in a mannose-independent manner. Importantly, we identified a potential FimH receptor as endo-1,3-ß-d-Glucanase and found that this interaction is strong and specific, with a dissociation constant in the nanomolar range. This research advances our comprehension of Salmonella's interactions with plant surfaces, offering insights that can aid in minimizing contamination risks and improving the safety of fresh, unprocessed foods.


Asunto(s)
Manosa , Salmonella typhimurium , Salmonella typhimurium/genética , Manosa/metabolismo , Spinacia oleracea , Proteínas Fimbrias/genética , Proteínas Fimbrias/química , Proteínas Fimbrias/metabolismo , Adhesinas Bacterianas/genética , Adhesión Bacteriana/genética
9.
Euro Surveill ; 29(31)2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39092529

RESUMEN

As other European countries, France is experiencing a resurgence of pertussis in 2024. Between 1 January and 31 May 2024, 5,616 (24.9%) positive Bordetella pertussis qPCR tests were identified, following a 3-year period of almost null incidence. Of 67 cultured and whole genome sequenced B. pertussis isolates, 66 produced pertactin and 56 produced FIM2, in contrast to pre-COVID-19 years. One isolate of genotype Bp-AgST4 was resistant to macrolides. Pertussis resurgence may favour isolates that produce FIM2 and pertactin.


Asunto(s)
Antibacterianos , Bordetella pertussis , Macrólidos , Tos Ferina , Bordetella pertussis/genética , Bordetella pertussis/aislamiento & purificación , Bordetella pertussis/efectos de los fármacos , Humanos , Francia/epidemiología , Macrólidos/farmacología , Tos Ferina/epidemiología , Tos Ferina/microbiología , Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Pruebas de Sensibilidad Microbiana , Proteínas de la Membrana Bacteriana Externa/genética , Secuenciación Completa del Genoma , Factores de Virulencia de Bordetella/genética , Genotipo , Adulto , Niño , Incidencia , Preescolar
10.
Foodborne Pathog Dis ; 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38593459

RESUMEN

Escherichia coli are present in the human and animal microbiome as facultative anaerobes and are viewed as an integral part of the whole gastrointestinal environment. In certain circumstances, some species can also become opportunistic pathogens responsible for severe infections in humans. These infections are caused by the enterotoxinogenic E. coli, enteroinvasive E. coli, enteropathogenic E. coli and the enterohemorrhagic E. coli species, frequently present in food products and on food matrices. Severe human infections can be caused by consumption of meat contaminated upon exposure to animal feces, and as such, farm animals are considered to be a natural reservoir. The mechanisms by which these four major species of E. coli adhere and persist in meat postslaughter are of major interest to public health and food processors given their frequent involvement in foodborne outbreaks. This review aims to structure and provide an update on the mechanistic roles of environmental factors, curli, type I and type IV pili on E. coli adherence/interaction with meat postslaughter. Furthermore, we emphasize on the importance of bacterial surface structures, which can be used in designing interventions to enhance food safety and protect public health by reducing the burden of foodborne illnesses.

11.
Genes Cells ; 27(11): 657-674, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36057789

RESUMEN

Escherichia coli (E. coli) has multiple copies of the chaperone-usher (CU) pili operon in five fimbria groups: CU pili, curli, type IV pili, type III secretion pili, and type IV secretion pili. Commensal E. coli K-12 contains 12 CU pili operons. Among these operons, Sfm is expressed by the sfmACDHF operon. Transcriptome analyses, reporter assays, and chromatin immunoprecipitation PCR analyses reported that FimZ directly binds to and activates the sfmA promoter, transcribing sfmACDHF. In addition, FimZ regularly induces constant cell elongation in E. coli, which is required for F-type ATPase function. The bacterial two-hybrid system showed a specific interaction between FimZ and the α subunit of the cytoplasmic F1 domain of F-type ATPase. Studies performed using mutated FimZs have revealed two active forms, I and II. Active form I is required for constant cell elongation involving amino acid residues K106 and D109. Active form II additionally required D56, a putative phosphorylation site, to activate the sfmA promoter. The chromosomal fimZ was hardly expressed in parent strain but functioned in phoB and phoP double-gene knockout strains. These insights may help to understand bacterial invasion restricted host environments by the sfm γ-type pili.


Asunto(s)
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Fimbrias/genética , Proteínas Fimbrias/metabolismo , Regulación Bacteriana de la Expresión Génica , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Chaperonas Moleculares/genética , Adenosina Trifosfatasas/genética
12.
Appl Environ Microbiol ; 89(7): e0057523, 2023 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-37310347

RESUMEN

This study is a continuation by the Environmental Biotechnology Group of the University of Tübingen in memoriam to Reinhard Wirth, who initiated the work on Mth60 fimbriae at the University of Regensburg. Growth in biofilms or biofilm-like structures is the prevailing lifestyle for most microbes in nature. The first crucial step to initiate biofilms is the adherence of microbes to biotic and abiotic surfaces. Therefore, it is crucial to elucidate the initial step of biofilm formation, which is generally established through cell-surface structures (i.e., cell appendages), such as fimbriae or pili, that adhere to biotic and abiotic surfaces. The Mth60 fimbriae of Methanothermobacter thermautotrophicus ΔH are one of only a few known archaeal cell appendages that do not assemble via the type IV pili assembly mechanism. Here, we report the constitutive expression of Mth60 fimbria-encoding genes from a shuttle-vector construct and the deletion of the Mth60 fimbria-encoding genes from the genomic DNA of M. thermautotrophicus ΔH. For this, we expanded our system for genetic modification of M. thermautotrophicus ΔH using an allelic-exchange method. While overexpression of the respective genes increased the number of Mth60 fimbriae, deletion of the Mth60 fimbria-encoding genes led to a loss of Mth60 fimbriae in planktonic cells of M. thermautotrophicus ΔH compared to the wild-type strain. This, either increased or decreased, number of Mth60 fimbriae correlated with a significant increase or decrease of biotic cell-cell connections in the respective M. thermautotrophicus ΔH strains compared to the wild-type strain. IMPORTANCE Methanothermobacter spp. have been studied for the biochemistry of hydrogenotrophic methanogenesis for many years. However, a detailed investigation of certain aspects, such as regulatory processes, was impossible due to the lack of genetic tools. Here, we amend our genetic toolbox for M. thermautotrophicus ΔH with an allelic exchange method. We report the deletion of genes that encode the Mth60 fimbriae. Our findings provide the first genetic evidence of whether the expression of these genes underlies regulation and reveal a role of the Mth60 fimbriae in the formation of cell-cell connections of M. thermautotrophicus ΔH.


Asunto(s)
Biopelículas , Fimbrias Bacterianas , Fimbrias Bacterianas/genética , Methanobacteriaceae/genética , Methanobacteriaceae/metabolismo
13.
Vet Res ; 54(1): 99, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37875985

RESUMEN

Initial stages of Salmonella Typhimurium infection involve a series of coordinated events aimed at reaching, attaching to, and invading host cells. Virulence factors such as flagella, fimbriae, and secretion systems play crucial roles in these events and are regulated in response to the host environment. The first point of contact between the pathogen and host is the intestinal epithelial layer, which normally serves as a barrier against invading pathogens, but can also be an entry site for pathogens. The integrity of this barrier can be modulated by the hypoxic environment of the intestines, created by the presence of trillions of microbes. Variable oxygen concentrations can strongly affect many functions of the gut, including secretion of cytokines and growth factors from the host site and affect the ability of Salmonella to persist, invade, and replicate. In this study, we investigated the first stages of Salmonella Typhimurium infection under hypoxic conditions in vitro and found that low oxygen levels significantly decreased bacterial adhesion. Using adhesion and motility assays, biofilm formation tests, as well as gene expression and cytokine secretion analysis, we identified a hypoxia-specific cross-talk between the expression of type 1 fimbriae and flagella, suggesting that altered flagellin expression levels affect the motility of bacteria and further impact their adhesion level, biofilm formation ability, and innate immune response. Overall, understanding how Salmonella interacts with its variable host environment provides insights into the virulence mechanisms of the bacterium and information regarding strategies for preventing or treating infections. Further research is required to fully understand the complex interplay between Salmonella and its host environment.


Asunto(s)
Flagelina , Salmonella typhimurium , Animales , Salmonella typhimurium/genética , Factores de Virulencia/metabolismo , Hipoxia/veterinaria , Oxígeno/metabolismo , Proteínas Bacterianas/genética , Adhesión Bacteriana
14.
Avian Pathol ; 52(6): 412-419, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37526573

RESUMEN

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a zoonotic pathogen that can infect both humans and animals. Among the 13 types of fimbrial operons in S. Enteritidis, the highly conserved Peg fimbriae play a crucial role in the adhesion and invasion of S. Enteritidis into host cells but are not well studied. In this study, we identified the ATP synthase subunit alpha (ATPase α) as a ligand of Peg fimbriae using ligand blotting and mass spectrometry techniques. We confirmed the in vitro binding of ATPase α to the purified adhesion protein (PegD). Furthermore, we used siRNA to suppress the expression of ATPase α gene Atp5a1 in Leghorn male hepatoma (LMH) cells, which resulted in a significant reduction in the adhesion rate of S. Enteritidis to the cells (P < 0.05). The findings in this study provide insight into the mechanism of S. Enteritidis infection through Peg fimbriae and highlight the importance of ATPase α in the adhesion process.RESEARCH HIGHLIGHTS Ligand blotting was performed to screen the ligand of S. Enteritidis Peg fimbriae.Binding assay confirmed that ATPase α is the ligand of the Peg fimbriae.siRNA targeting ATPase α gene (Atp5a1) significantly reduced S. Enteritidis adhesion.


Asunto(s)
Salmonelosis Animal , Salmonella enteritidis , Animales , Masculino , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Pollos/genética , Proteínas Fimbrias/genética , Proteínas Fimbrias/metabolismo , Ligandos , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Salmonella enteritidis/genética
15.
BMC Vet Res ; 19(1): 187, 2023 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-37789311

RESUMEN

BACKGROUND: Avian Escherichia coli (E.coli) type 1 fimbriae adhere to avian tracheal epithelial cells through the FimH protein. However, the adhesion-related antigen is still unknown. The purpose of this study was to analyze the antigenicity of the type 1 fimbrial FimH protein of wild-type avian E. coli, screen antigen epitopes, and prepare monoclonal antibodies (mAbs) that can block the adhesion of avian E. coli. RESULTS: In this study, the nucleic acid homologies of MG2 (O11), TS12 (O18), and YR5 (O78) with K12 were 97.7%, 99.6%, and 97.7%, respectively, and the amino acid sequence similarity reached 98.7%, 99.3%, and 98.0%, respectively. The epitopes and hydrophilicities of the FimH proteins of these three strains were similar. The more obvious lectin domain epitopes were located at FimH protein positions 111-124 and 154-162. The mAbs 7C2 and 7D8 against these two epitopes were prepared. An adhesion inhibition test showed that 7C2 and 7D8 blocked bacterial adhesion to avian tracheal epithelial cells. The mAb 7C2 against the 111-124 epitope inhibited O78 strain adhesion by 93%, and the mAb 7D8 against the 154-162 epitope inhibited O78 strain adhesion by 49%, indicating that these two epitopes are closely related to the adhesion of type 1 fimbriae. However, only the 111-124 epitope-recognizing mAb 7C2 inhibited bacterial agglutination of erythrocytes, indicating that host cell receptor binding and erythrocyte agglutination are not mediated by the same spatial locations within the FimH protein. CONCLUSIONS: The results demonstrate that the mAbs 7C2 and 7D8 against FimH protein positions 111-124 and 154-162 could inhibit the adhesion of E.coli to the chicken trachea.


Asunto(s)
Escherichia coli , Proteínas Fimbrias , Animales , Escherichia coli/genética , Proteínas Fimbrias/genética , Epítopos/metabolismo , Adhesinas de Escherichia coli/genética , Adhesinas de Escherichia coli/química , Aglutininas/metabolismo , Adhesión Bacteriana
16.
Genomics ; 114(6): 110509, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36273742

RESUMEN

The compatibility of plasmids with new host cells is significant given their role in spreading antimicrobial resistance (AMR) and virulence factor genes. Evaluating this using in vitro screening is laborious and can be informed by computational analyses of plasmid-host compatibility through rates of protein-protein interactions (PPIs) between plasmid and host cell proteins. We identified large excesses of such PPIs in eight important plasmids, including pOXA-48, using most known bacteria (n = 4363). 23 species had high rates of interactions with four blaOXA-48-positive plasmids. We also identified 48 species with high interaction rates with plasmids common in Escherichia coli. We found a strong association between one plasmid and the fimbrial adhesin operon pil, which could enhance host cell adhesion in aqueous environments. An excess rate of PPIs could be a sign of host-plasmid compatibility, which is important for AMR control given that plasmids like pOXA-48 move between species with ease.


Asunto(s)
Bacterias
17.
Odontology ; 111(3): 719-727, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36525152

RESUMEN

Periodontopathic bacteria cause an inflammatory disease localized in the periodontal tissue and are associated with various conditions in other body parts. The distribution of periodontopathic bacterial species in the tonsils is unknown, even though the tonsils are located close to the oral cavity, and inflammation of the tonsils causes various systemic diseases. We detected the major periodontopathic bacterial species residing in saliva and tonsil specimens from 25 subjects undergoing tonsillectomy. Nine of the ten major periodontopathic bacterial species were detected by polymerase chain reaction of tonsil specimens, among which Campylobacter rectus was the most common (80.0%), followed by Porphyromonas gingivalis (36.0%). The other seven types of periodontopathic bacterial species were distributed with 0% to 25.0% abundance in the tonsil specimens. C. rectus had a high detection rate in tonsil specimens (> 75.0%), regardless of whether it was detected in the corresponding saliva specimens. However, the detection rate for P. gingivalis in tonsil specimens was significantly higher in subjects with P. gingivalis-positive saliva (77.8%) than in those with P. gingivalis-negative saliva (6.3%; P < 0.001). Furthermore, 75.0% of P. gingivalis in tonsil specimens did not have the known fimA gene that encodes the 41-kDa filamentous appendage protein FimA, which is expressed on the cell surface of the bacteria. Our results suggest that certain periodontopathic bacterial species are detected in the tonsils either independently of or depending on their distribution in the oral cavity and may be involved in tonsil-related diseases.


Asunto(s)
Bacteroides , Placa Dental , Humanos , Bacteroides/genética , Tonsila Palatina/química , Saliva/química , Placa Dental/microbiología , Porphyromonas gingivalis , ADN Bacteriano/análisis
18.
Indian J Microbiol ; 63(4): 632-644, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38034905

RESUMEN

Surface-growing antibiotic-resistant pathogenic Salmonella is emerging as a global health challenge due to its high economic loss in the poultry industry. Their pathogenesis, increasing antimicrobial resistance, and biofilm formation make them challenging to treat with traditional therapy. The identification of antimicrobial herbal ingredients may provide valuable solutions to solve this problem. Therefore, our aim is to evaluate the potency of nano garlic as the  alternative of choice against multidrug-resistant (MDR) Salmonella isolates using disc diffusion and microdilution assays. Then, checkerboard titration in trays was applied, and FIC was measured to identify the type of interaction between the two antimicrobials. A disc diffusion assay revealed that neomycin was the drug of choice. The range of nano garlic MIC was 12.5-25 µg/ml, while the neomycin MIC range was 32-64 µg/ml. The FIC index established a synergistic association between the two tested drugs in 85% of isolates. An experimental model was used including nano garlic and neomycin alone and in combination against Salmonella infection. The combination therapy significantly improved body productivity and inhibited biofilm formation by more than 50% down regulating the CsgBAD, motB, and sipA operons, which are responsible for curli fimbriae production and biofilm formation in Salmonella serotypes.

19.
J Bacteriol ; 204(9): e0017222, 2022 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-36005809

RESUMEN

Klebsiella spp. commonly cause both uncomplicated urinary tract infection (UTI) and recurrent UTI (rUTI). Klebsiella quasipneumoniae, a relatively newly defined species of Klebsiella, has been shown to be metabolically distinct from Klebsiella pneumoniae, but its type 1 and type 3 fimbriae have not been studied. K. pneumoniae uses both type 1 and type 3 fimbriae to attach to host epithelial cells. The type 1 fimbrial operon is well conserved between Escherichia coli and K. pneumoniae apart from fimK, which is unique to Klebsiella spp. FimK contains an N-terminal DNA binding domain and a C-terminal phosphodiesterase (PDE) domain that has been hypothesized to cross-regulate type 3 fimbriae expression via modulation of cellular levels of cyclic di-GMP. Here, we find that a conserved premature stop codon in K. quasipneumoniae fimK results in truncation of the C-terminal PDE domain and that K quasipneumoniae strain KqPF9 cultured bladder epithelial cell association and invasion are dependent on type 3 but not type 1 fimbriae. Further, we show that basal expression of both type 1 and type 3 fimbrial operons as well as cultured bladder epithelial cell association is elevated in KqPF9 relative to uropathogenic K. pneumoniae TOP52. Finally, we show that complementation of KqPF9ΔfimK with the TOP52 fimK allele reduced type 3 fimbrial expression and cultured bladder epithelial cell attachment. Taken together these data suggest that the C-terminal PDE of FimK can modulate type 3 fimbrial expression in K. pneumoniae and its absence in K. quasipneumoniae may lead to a loss of type 3 fimbrial cross-regulation. IMPORTANCE K. quasipneumoniae is often indicated as the cause of opportunistic infections, including urinary tract infection, which affects >50% of women worldwide. However, the virulence factors of K. quasipneumoniae remain uninvestigated. Prior to this work, K. quasipneumoniae and K. pneumoniae had only been distinguished phenotypically by metabolic differences. This work contributes to the understanding of K. quasipneumoniae by evaluating the contribution of type 1 and type 3 fimbriae, which are critical colonization factors encoded by all Klebsiella spp., to K. quasipneumoniae bladder epithelial cell attachment in vitro. We observe clear differences in bladder epithelial cell attachment and regulation of type 3 fimbriae between uropathogenic K. pneumoniae and K. quasipneumoniae that coincide with a structural difference in the fimbrial regulatory gene fimK.


Asunto(s)
Vejiga Urinaria , Infecciones Urinarias , Codón sin Sentido/metabolismo , Células Epiteliales , Escherichia coli/genética , Femenino , Fimbrias Bacterianas/metabolismo , Humanos , Klebsiella , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/metabolismo , Hidrolasas Diéster Fosfóricas/genética , Factores de Virulencia/genética
20.
Infect Immun ; 90(3): e0066221, 2022 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-34978926

RESUMEN

Adherent-invasive Escherichia coli (AIEC) is involved in onset and/or exacerbation of Crohn's disease (CD). AIEC adapts to the gut environment by altering gene expression programs, leading to successful gut-lumen colonization. However, the underlying mechanism of gut colonization is still far from clarified. Here, we show the role of UvrY, a response regulator of bacterial two-component signal transduction systems, in AIEC gut colonization. An AIEC mutant lacking the uvrY gene exhibited impairment of competitive colonization in the murine intestinal tract. UvrY contributes to functional expression of type 1 fimbriae by activating expression of small RNA CsrB, which confers adherence and invasion into epithelial cells on AIEC. In contrast, acetate suppresses the UvrY-dependent expression of type 1 fimbriae, resulting in less efficient cell invasion and attenuated gut colonization. Our findings might lead to therapeutic interventions for CD, in which inhibitions of UvrY activation and acetate supplementation reduce the colonization levels of AIEC by decreasing type 1 fimbria expression.


Asunto(s)
Enfermedad de Crohn , Infecciones por Escherichia coli , Acetatos/metabolismo , Animales , Adhesión Bacteriana/genética , Enfermedad de Crohn/microbiología , Células Epiteliales/microbiología , Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Fimbrias Bacterianas/genética , Fimbrias Bacterianas/metabolismo , Mucosa Intestinal/metabolismo , Ratones
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