Relatedness and Phylogeny Within the Family of Periplasmic Chaperones Involved in the Assembly of Pili or Capsule-Like Structures of Gram-Negative Bacteria

1997 ◽  
Vol 44 (3) ◽  
pp. 299-309 ◽  
Author(s):  
Alessandra Bonci ◽  
Alessandra Chiesurin ◽  
Patrizia Muscas ◽  
Gian Maria Rossolini
Keyword(s):  
Gram Negative Bacteria ◽  
Gram Negative ◽  
The Family ◽  
Periplasmic Chaperones

scholarly journals Lipopolysaccharide-Trap-Fc, a Multifunctional Agent To Battle Gram-Negative Bacteria

2009 ◽  
Vol 77 (7) ◽  
pp. 2925-2931 ◽  
Author(s):  
Philipp Groß ◽  
Katharina Brandl ◽  
Christine Dierkes ◽  
Jürgen Schölmerich ◽  
Bernd Salzberger ◽  
...  
Keyword(s):  
Myeloid Differentiation ◽  
Gram Negative Bacteria ◽  
Bacterial Sepsis ◽  
Tlr Signaling ◽  
Monocytic Cells ◽  
Gram Negative ◽  
The Family ◽  
Myeloid Differentiation Factor ◽  
Lps Treatment

ABSTRACT The family of Toll-like receptors (TLRs) plays a pivotal role in host defense against pathogens. However, overstimulation of these receptors may lead to uncontrolled general inflammation and eventually to systemic organ dysfunction or failure. With the intent to control overwhelming inflammation during gram-negative bacterial sepsis, we constructed soluble fusion proteins of the lipopolysaccharide (LPS)-receptor complex to modulate TLR signaling in multiple ways. The extracellular domain of mouse TLR4 and mouse myeloid differentiation factor 2 (MD-2) fusions (LPS-Trap) were linked to human immunoglobulin G Fc domains (LPS-Trap-Fc). In addition to the ability to bind LPS or gram-negative bacteria and to inhibit interleukin-6 secretion of monocytic cells after LPS treatment, LPS-Trap-Fc was able to opsonize fluorescent Escherichia coli particles. This led to enhancement of phagocytosis by monocytic cells which was strictly dependent on the presence of the Fc region. Moreover, only LPS-Trap-Fc- and not LPS-Trap-coated bacteria were sensitized to complement killing. Therefore, LPS-Trap-Fc not only neutralizes LPS but also, after binding to bacteria, enhances phagocytosis and complement-mediated killing and could thus act as a multifunctional agent to fight gram-negative bacteria in vivo.

scholarly journals Bactericidal/permeability-increasing protein in the reproductive system of male mice may be involved in the sperm–oocyte fusion

Reproduction ◽  
2013 ◽  
Vol 146 (2) ◽  
pp. 135-144 ◽  
Author(s):  
Kun Li ◽  
Yue Liu ◽  
Xiaoyu Xia ◽  
Li Wang ◽  
Meige Lu ◽  
...  
Keyword(s):  
Transport Proteins ◽  
Seminal Vesicles ◽  
Lipid Transport ◽  
Human Neutrophils ◽  
Gram Negative Bacteria ◽  
Male Mice ◽  
Gram Negative ◽  
Major Function ◽  
The Family ◽  
Lps Binding

Bactericidal/permeability-increasing protein (BPI) is a 455-residue (∼55 kDa) protein found mainly in the primary (azurophilic) granules of human neutrophils. BPI is an endogenous antibiotic protein that belongs to the family of mammalian lipopolysaccharide (LPS)-binding and lipid transport proteins. Its major function is to kill Gram-negative bacteria, thereby protecting the host from infection. In addition, BPI can inhibit angiogenesis, suppress LPS-mediated platelet activation, increase DNA synthesis, and activate ERK/Akt signaling. In this study, we found thatBpiwas expressed in the testis and epididymis but not in the seminal vesicles, prostate, and solidification glands. BPI expression in the epididymis increased upon upregulation of testosterone, caused by injection of GNRH. In orchidectomized mice, BPI expression was significantly reduced, but its expression was restored to 30% of control levels in orchidectomized mice that received supplementary testosterone. The number of sperm fused per egg significantly decreased after incubation with anti-BPI antiserum. These results suggest that BPI may take part in the process of sperm–oocyte fusion and play a unique and significant role in reproduction.

scholarly journals Classifying β-Barrel Assembly Substrates by Manipulating Essential Bam Complex Members

2016 ◽  
Vol 198 (14) ◽  
pp. 1984-1992 ◽  
Author(s):  
Tara F. Mahoney ◽  
Dante P. Ricci ◽  
Thomas J. Silhavy
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Mechanistic Model ◽  
Outer Membrane Proteins ◽  
Permeability Barrier ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Content Type ◽  
Bam Complex ◽  
Periplasmic Chaperones

ABSTRACTThe biogenesis of the outer membrane (OM) ofEscherichia coliis a conserved and vital process. The assembly of integral β-barrel outer membrane proteins (OMPs), which represent a major component of the OM, depends on periplasmic chaperones and the heteropentameric β-barrel assembly machine (Bam complex) in the OM. However, not all OMPs are affected by null mutations in the same chaperones or nonessential Bam complex members, suggesting there are categories of substrates with divergent requirements for efficient assembly. We have previously demonstrated two classes of substrates, one comprising large, low-abundance, and difficult-to-assemble substrates that are heavily dependent on SurA and also Skp and FkpA, and the other comprising relatively simple and abundant substrates that are not as dependent on SurA but are strongly dependent on BamB for assembly. Here, we describe novel mutations inbamDthat lower levels of BamD 10-fold and >25-fold without altering the sequence of the mature protein. We utilized these mutations, as well as a previously characterized mutation that lowers wild-type BamA levels, to reveal a third class of substrates. These mutations preferentially cause a marked decrease in the levels of multimeric proteins. This susceptibility of multimers to lowered quantities of Bam machines in the cell may indicate that multiple Bam complexes are needed to efficiently assemble multimeric proteins into the OM.IMPORTANCEThe outer membrane (OM) of Gram-negative bacteria, such asEscherichia coli, serves as a selective permeability barrier that prevents the uptake of toxic molecules and antibiotics. Integral β-barrel proteins (OMPs) are assembled by the β-barrel assembly machine (Bam), components of which are conserved in mitochondria, chloroplasts, and all Gram-negative bacteria, including many clinically relevant pathogenic species. Bam is essential for OM biogenesis and accommodates a diverse array of client proteins; however, a mechanistic model that accounts for the selectivity and broad substrate range of Bam is lacking. Here, we show that the assembly of multimeric OMPs is more strongly affected than that of monomeric OMPs when essential Bam complex components are limiting, suggesting that multiple Bam complexes are needed to assemble multimeric proteins.

scholarly journals Multicenter Antimicrobial Susceptibility Survey of Gram-Negative Bacteria Isolated from Patients with Community-Acquired Infections in the People's Republic of China

2006 ◽  
Vol 50 (1) ◽  
pp. 374-378 ◽  
Author(s):  
Thomas K. W. Ling ◽  
Jianhui Xiong ◽  
Yunsong Yu ◽  
Ching Ching Lee ◽  
Huifen Ye ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Susceptibility ◽  
People’S Republic Of China ◽  
Gram Negative Bacteria ◽  
People's Republic Of China ◽  
Gram Negative ◽  
Republic Of China ◽  
Extended Spectrum ◽  
The Family

ABSTRACT A survey of 2,099 gram-negative bacilli from community infections at seven centers in the People's Republic of China is reported. The rates of resistance of 1,615 isolates of the family Enterobacteriaceae were as follows: 40.8% for ciprofloxacin, 32.2% for gentamicin, 0% for imipenem or ertapenem, and 14.7% for cefotaxime. The rates of extended-spectrum β-lactamase production were 16% for Escherichia coli and 17% for Klebsiella.

scholarly journals Boar Semen Contamination: Identification of Gram-Negative Bacteria and Antimicrobial Resistance Profile

Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Luminita Costinar ◽  
Viorel Herman ◽  
Elena Pitoiu ◽  
Ionica Iancu ◽  
Janos Degi ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Artificial Insemination ◽  
Bacterial Contamination ◽  
Bacterial Species ◽  
Reproductive Capacity ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
The Family ◽  
Boar Semen

Bacterial contamination of boar semen occurs with some frequency in artificial insemination centers and may have a negative effect on the quality of the semen as well as on the sows’ reproductive capacity. Normally, the source of bacterial contamination in pig seminal doses is the own boar. However, distilled water or laboratory equipment used to elaborate the seminal doses can be an important source of bacterial contamination. This study focused on the identification of gram-negative bacteria in boar semen, and impact on the quality of ejaculates obtained from boar, as well as on the establishment of antimicrobial resistance patterns of isolated gram-negative bacteria. Semen samples were collected from 96 boars, ranging in age from 12–36 month, from three artificial insemination centers from the North-West of Romania. Bacterial species were identified by two methods: matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and API 20 E (BioMerieux, France). The main bacteria isolated from the doses diluted semen were gram-negative bacteria (47.91%), with a majority of the contaminant bacteria belonging to the family Enterobacteriaceae: Seratia marcescens 19.56%, Proteus mirabilis 15.21% and Escherichia coli 10.86% and to the family Pseudomonaceae: Ralstonia picketii 17.39%, Burkholderia cepacia 10.86%, Pseudomonas aeruginosa 8.69%, and Pseudomonas fluorescens 4.34%, respectively. More than half of these isolates (56.52%) were resistant to gentamycin and 58.69% were resistant to penicillin. These antibiotics are very frequently added in sperm diluent in the centers for the processing of sperm from boars in Romania. Regular monitoring for bacterial contamination is an important aspect of a control program.

scholarly journals Complete Genome Sequence of the Citrobacter freundii Type Strain

2020 ◽  
Vol 9 (19) ◽  
Author(s):  
Kenneth H. Wan ◽  
Soo Park ◽  
Becky M. Hess ◽  
Michael J. Neff ◽  
Benjamin W. Booth ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Type Strain ◽  
Gram Negative Bacteria ◽  
Citrobacter Freundii ◽  
Gram Negative ◽  
Content Type ◽  
The Family ◽  
Facultative Anaerobic

Citrobacter freundii is a species of facultative anaerobic Gram-negative bacteria of the family Enterobacteriaceae. The complete genome is composed of a single chromosomal circle of 4,957,773 bp with a G+C content of 52%.

Activité antimicrobienne d'antioxydants phénoliques

1978 ◽  
Vol 24 (11) ◽  
pp. 1306-1320 ◽  
Author(s):  
Pierre Turcotte ◽  
Samir A. Saheb
Keyword(s):  
Culture Media ◽  
Osmotic Shock ◽  
Bacterial Species ◽  
Butylated Hydroxytoluene ◽  
In Vitro Assays ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
The Family ◽  
Increased Sensitivity

The antimicrobial activity of three antioxydants, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and ethoxyquin (ETO) was studied. In vitro assays showed that when these antioxydants are added to the culture media at concentrations lower or equal to that used in nutrition, they inhibit or decrease the growth of certain microorganisms. BHT showed the most marked effect, affecting Gram-positive bacteria at a higher degree than the Gram-negative bacteria belonging to the family Enterobacteriaceae. Inactivation study of different bacterial species by BHT revealed differences in sensitivity among a single genus and between strains of the same species. The association of ETO with BHT results in an increase of the inhibitory activity. The increased sensitivity to BHT resulting from the osmotic shock of Escherichia coli cells suggests that the resistance to BHT of the Gram-negative bacteria belonging to the family Enterobacteriaceae might be due in part to the structure of their cell wall.

scholarly journals Genetic and Transcriptional Analyses of theVibrio cholerae Mannose-Sensitive Hemagglutinin Type 4 Pilus Gene Locus

1999 ◽  
Vol 181 (4) ◽  
pp. 1110-1117 ◽  
Author(s):  
Jane W. Marsh ◽  
Ronald K. Taylor
Keyword(s):  
Gene Locus ◽  
Mobile Genetic Element ◽  
Direct Repeat ◽  
The Other ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
The Family ◽  
Colonization Factors ◽  
El Tor

ABSTRACT The mannose-sensitive hemagglutinin (MSHA) of the Vibrio cholerae O1 El Tor biotype is a member of the family of type 4 pili. Type 4 pili are found on the surface of a variety of gram-negative bacteria and have demonstrated importance as host colonization factors, bacteriophage receptors, and mediators of DNA transfer. The gene locus required for the assembly and secretion of the MSHA pilus has been localized to a 16.7-kb region of the V. cholerae chromosome. Sixteen genes required for hemagglutination, including five that encode prepilin or prepilin-like proteins, have been identified. Examination of MSHA-specific cDNAs has localized two promoters that drive expression of these genes. This evidence indicates that the MSHA gene locus is transcriptionally organized into two operons, one encoding the secretory components and the other encoding the structural subunits, an arrangement unique among previously characterized type 4 pilus loci. The genes flanking the MSHA locus encode proteins that show homology to YhdA and MreB ofEscherichia coli. In E. coli, theyhdA and mreB genes are adjacent to each other on the chromosome. The finding that the MSHA locus lies between these two E. coli homologs and that it is flanked by a 7-bp direct repeat suggests that the MSHA locus may have been acquired as a mobile genetic element.

scholarly journals Epidemiology of bacterial colonization at intensive care unit admission with emphasis on extended-spectrum β-lactamase- and metallo-β-lactamase-producing Gram-negative bacteria – an Indian experience

2010 ◽  
Vol 59 (8) ◽  
pp. 955-960 ◽  
Author(s):  
Afzal Azim ◽  
Mayank Dwivedi ◽  
P. Bhaskar Rao ◽  
A. K. Baronia ◽  
R. K. Singh ◽  
...  
Keyword(s):  
Risk Factors ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Bacterial Colonization ◽  
Empiric Antibiotic Therapy ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Extended Spectrum ◽  
The Family

An important risk factor for nosocomial infection in an intensive care unit (ICU) is prior colonization. This study was undertaken to determine the spectrum of bacterial colonization and predisposing risk factors in patients being admitted to an ICU in India, with special emphasis on extended-spectrum β-lactamase (ESBL)- and metallo-β-lactamase (MBL)-producing Gram-negative bacteria. Nasal, oral and rectal swab samples were collected and processed for isolation of ESBL-producing Gram-negative bacteria and MBL-producing Pseudomonas aeruginosa and Acinetobacter species. Bacterial colonization (of one or more sites) on admission was detected in 51 out of 96 patients included in the study. Non-fermenters, i.e. P. aeruginosa and Acinetobacter baumannii, were the most common colonizers, present in 37 patients, with simultaneous colonization in 12 patients. A total of 16 patients were colonized with MBL-producing members of the family Enterobacteriaceae, out of which 11 isolates (from 5 patients) were also carrying ESBL-encoding genes. As for MBLs, most of our patients have shown colonization with ESBL-producing bacteria. On admission, 47 of 51 patients (92 %) have been colonized by ESBL-producing members of the family Enterobacteriaceae, at one or more of the three anatomical sites. The most common MBL subtype was bla IMP (51.56 %), whereas bla CTX was the most common gene (84.9 %) identified among ESBL producers. Risk factors for colonization on admission to the ICU were hospitalization for more than 48 h, use of ≥3 groups of antibiotics, co-morbidities and mechanical ventilation for more than 48 h prior to ICU admission. There is an increasing incidence of MBLs and ESBLs in the Indian population. The identified risk factors can be used as a guide for empiric antibiotic therapy targeted to these resistant bacteria.

scholarly journals CLINICAL CASE PRESENTATION LEPTOTRIHOZ LANGUAGE

2014 ◽  
Vol 10 (6) ◽  
pp. 24-27
Author(s):  
Г. Флейшер ◽  
G. Fleischer ◽  
Э. Воронцова ◽  
E. Vorontsova ◽  
И. Фомичев ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Humoral Immunity ◽  
Clinical Case ◽  
Oral Candidiasis ◽  
Gram Negative Bacteria ◽  
Case Presentation ◽  
Gram Negative ◽  
The Family

<p>Currently, the practice of doctors and dentists are increasingly found a variety of diseases of organs and tissues of the oral cavity associated with the weakening of local and humoral immunity, the development of oral candidiasis. One such disease is leptotrihoz language. The authors describe the clinical case of a 40 year-old woman referred to the clinic complaining of difficulty in swallowing food, presence of redness on the tongue. Microbiological studies revealed leptotrihii (Leptotrichia) – anaerobic gram-negative bacteria belonging to the family Fusobacteriaceae. The features of the therapy and prevention of this disease. </p>

Sign in / Sign up

Export Citation Format

Share Document