Genes required for assembly and function of the protein synthetic system in Chlamydia trachomatis are expressed early in elementary to reticulate body transformation

1997 ◽  
Vol 255 (6) ◽  
pp. 637-642 ◽  
Author(s):  
H. C. Gérard ◽  
J. A. Whittum-Hudson ◽  
A. P. Hudson
Keyword(s):  
Chlamydia Trachomatis ◽  
Reticulate Body ◽  
And Function

scholarly journals Effects ofMentha suaveolensEssential Oil onChlamydia trachomatis

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Rosa Sessa ◽  
Marisa Di Pietro ◽  
Fiorenzo De Santis ◽  
Simone Filardo ◽  
Rino Ragno ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Substantial Reduction ◽  
Developmental Cycle ◽  
Elementary Body ◽  
Promising Candidate ◽  
Common Cause ◽  
Sexually Transmitted ◽  
Reticulate Body ◽  
Preventative Strategy

Chlamydia trachomatis, the most common cause of sexually transmitted bacterial infection worldwide, has a unique biphasic developmental cycle alternating between the infectious elementary body and the replicative reticulate body.C. trachomatisis responsible for severe reproductive complications including pelvic inflammatory disease, ectopic pregnancy, and obstructive infertility. The aim of our study was to evaluate whetherMentha suaveolensessential oil (EOMS) can be considered as a promising candidate for preventingC. trachomatisinfection. Specifically, we investigated thein vitroeffects of EOMS towardsC. trachomatisanalysing the different phases of chlamydial developmental cycle. Our results demonstrated that EOMS was effective towardsC. trachomatis, whereby it not only inactivated infectious elementary bodies but also inhibited chlamydial replication. Our study also revealed the effectiveness of EOMS, in combination with erythromycin, towardsC. trachomatiswith a substantial reduction in the minimum effect dose of antibiotic. In conclusion, EOMS treatment may represent a preventative strategy since it may reduceC. trachomatistransmission in the population and, thereby, reduce the number of new chlamydial infections and risk of developing of severe sequelae.

scholarly journals Chlamydial infection and disease in the koala

2005 ◽  
Vol 26 (2) ◽  
pp. 65 ◽  
Author(s):  
Peter Timms
Keyword(s):  
Chlamydia Trachomatis ◽  
Chlamydial Infection ◽  
Developmental Cycle ◽  
Elementary Body ◽  
Obligate Intracellular ◽  
Molecular Approaches ◽  
Reticulate Body ◽  
Wide Range ◽  
The Family ◽  
Serious Disease

Chlamydiae are obligate intracellular bacterial pathogens able to infect and cause serious disease in humans, birds and a remarkably wide range of warm and cold-blooded animals. The family Chlamydiaciae have traditionally been defined by their unique biphasic developmental cycle, involving the interconversion between an extracellular survival form, the elementary body and an intracellular replicative form, the reticulate body. However, as with many other bacteria, molecular approaches including 16SrRNA sequence are becoming the standard of choice. As a consequence, the chlamydiae are in a taxonomic state of flux. Prior to 1999, the family Chlamydiaceae consisted of one genus, Chlamydia, and four species, Chlamydia trachomatis, C. psittaci, C. pecorum and C. pneumoniae. In 1999, Everett et al proposed a reclassification of Chlamydia into two genera (Chlamydia and Chlamydophila) and nine species (Chlamydia trachomatis, C. suis, and C. muridarum and Chlamydophila psittaci, C. pneumoniae, C. felis, C. pecorum, C. abortus, and C. caviae). While some of these species are thought to be host specific (C. suis ? pigs, C. muridarum ? mice, C. felis ? cats, C. caviae ? guinea pigs) many are known to infect and cause disease in a wide range of hosts.

scholarly journals Kinematics of Intracellular Chlamydiae Provide Evidence for Contact-Dependent Development

2009 ◽  
Vol 191 (18) ◽  
pp. 5734-5742 ◽  
Author(s):  
David P. Wilson ◽  
Judith A. Whittum-Hudson ◽  
Peter Timms ◽  
Patrik M. Bavoil
Keyword(s):  
Chlamydia Trachomatis ◽  
Developmental Stages ◽  
Elementary Body ◽  
Average Speed ◽  
Dependent Development ◽  
Reticulate Body ◽  
Size Type ◽  
The Relationship ◽  
Chlamydial Inclusion ◽  
Present Experimental Evidence

ABSTRACT A crucial process of chlamydial development involves differentiation of the replicative reticulate body (RB) into the infectious elementary body (EB). We present experimental evidence to provide support for a contact-dependent hypothesis for explaining the trigger involved in differentiation. We recorded live-imaging of Chlamydia trachomatis-infected McCoy cells at key times during development and tracked the temporospatial trajectories of individual chlamydial particles. We found that movement of the particles is related to development. Early to mid-developmental stages involved slight wobbling of RBs. The average speed of particles increased sharply at 24 h postinfection (after the estimated onset of RB to EB differentiation). We also investigated a penicillin-supplemented culture containing EBs, RBs, and aberrantly enlarged, stressed chlamydiae. Near-immobile enlarged particles are consistent with their continued tethering to the chlamydial inclusion membrane (CIM). We found a significantly negative, nonlinear association between speed and size/type of particles, providing further support for the hypothesis that particles become untethered near the onset of RB to EB differentiation. This study establishes the relationship between the motion properties of the chlamydiae and developmental stages, whereby wobbling RBs gradually lose contact with the CIM, and RB detachment from the CIM is coincidental with the onset of late differentiation.

Expression of recombinant DNA introduced into Chlamydia trachomatis by electroporation

1994 ◽  
Vol 40 (7) ◽  
pp. 583-591 ◽  
Author(s):  
Jeffrey E. Tam ◽  
Carolyn H. Davis ◽  
Priscilla B. Wyrick
Keyword(s):  
Chlamydia Trachomatis ◽  
Plasmid Dna ◽  
Southern Hybridization ◽  
Recombinant Dna ◽  
Chloramphenicol Acetyltransferase ◽  
Developmentally Regulated ◽  
Reticulate Body ◽  
Body Development ◽  
Coli Plasmid

Electroporation was used to introduce DNA into the elementary bodies of the obligate parasitic bacterium Chlamydia trachomatis. The source of DNA for these experiments was the chimeric plasmid pPBW100, which was constructed from the well-characterized 7.5-kb plasmid of C. trachomatis and the Escherichia coli plasmid pBGS9. To select directly for C. trachomatis carrying pPBW100, an in-frame gene fusion between the chlamydial promoter P7248 and a promoterless chloramphenicol acetyltransferase (cat) cassette was incorporated into the plasmid. After infection of McCoy cells with electroporated elementary bodies containing pPBW100, the following were observed: (i) the plasmid DNA was detected inside the chloramphenicol-resistant chlamydial inclusions by in situ and Southern hybridization analyses; (ii) both physical and biochemical evidence showed that chloramphenicol acetyltransferase was synthesized by the electroporated C. trachomatis; (iii) expression of P7248::cat was developmentally regulated and occurred during the early stages of chlamydial reticulate body development; and (iv) although the expression from P7248::cat was mainly transient, there were rare instances where chloramphenicol-resistant C. trachomatis were observed after four passages.Key words: chlamydia, electroporation, chimeric plasmid, expression.

scholarly journals Distinct Defensin Profiles in Neisseria gonorrhoeae and Chlamydia trachomatis Urethritis Reveal Novel Epithelial Cell-Neutrophil Interactions

2005 ◽  
Vol 73 (8) ◽  
pp. 4823-4833 ◽  
Author(s):  
Edith Porter ◽  
Huixia Yang ◽  
Sujata Yavagal ◽  
Gloria C. Preza ◽  
Omar Murillo ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Neisseria Gonorrhoeae ◽  
Defense Mechanism ◽  
Differential Distribution ◽  
Sexually Transmitted ◽  
Innate Defense ◽  
Peptide Profiles ◽  
And Function

ABSTRACT Defensins are key participants in mucosal innate defense. The varied antimicrobial activity and differential distribution of defensins at mucosal sites indicate that peptide repertoires are tailored to site-specific innate defense requirements. Nonetheless, few studies have investigated changes in peptide profiles and function after in vivo pathogen challenge. Here, we determined defensin profiles in urethral secretions of healthy men and men with Chlamydia trachomatis- and Neisseria gonorrhoeae-mediated urethritis by immunoblotting for the epithelial defensins HBD1, HBD2, and HD5 and the neutrophil defensins HNP1 to -3 (HNP1-3). HBD1 was not detectable in secretions, and HBD2 was only induced in a small proportion of the urethritis patients; however, HD5 and HNP1-3 were increased in C. trachomatis infection and significantly elevated in N. gonorrhoeae infection. When HNP1-3 levels were low, HD5 appeared mostly as the propeptide; however, when HNP1-3 levels were >10 μg/ml, HD5 was proteolytically processed, suggesting neutrophil proteases might contribute to HD5 processing. HD5 and HNP1-3 were bactericidal against C. trachomatis and N. gonorrhoeae, but HD5 activity was dependent upon N-terminal processing of the peptide. In vitro proteolysis of proHD5 by neutrophil proteases and analysis of urethral secretions by surface-enhanced laser desorption ionization substantiated that neutrophils contribute the key convertases for proHD5 in the urethra during these infections. This contrasts with the small intestine, where Paneth cells secrete both proHD5 and its processing enzyme, trypsin. In conclusion, we describe a unique defensin expression repertoire in response to inflammatory sexually transmitted infections and a novel host defense mechanism wherein epithelial cells collaborate with neutrophils to establish an antimicrobial barrier during infection.

scholarly journals Inhibitory Activity of Pyrroloisoxazolidine Derivatives against Chlamydia trachomatis

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Min Ni ◽  
Shunxin Xu ◽  
Ziyi Liu ◽  
Yin Xue ◽  
Wenxia Xie ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Inhibitory Activity ◽  
Dependent Manner ◽  
Human Pathogens ◽  
High Concentration ◽  
Obligate Intracellular ◽  
Reticulate Body ◽  
Ic50 Values ◽  
Dose Dependent

The obligate intracellular bacterium Chlamydia trachomatis is a group of worldwide human pathogens that can lead to serious reproductive problems. The frequent clinical treatment failure promoted the development of novel antichlamydial agents. Here, we firstly reported a group of pyrroloisoxazolidine-inhibited C. trachomatis in a dose-dependent manner in vitro. Among them, compounds 1 and 2 exhibited the strongest inhibitory activity with IC50 values from 7.25 to 9.73 μM. The compounds disturbed the whole intracellular life cycle of C. trachomatis, mainly targeting the middle reticulate body proliferation stages. Besides, the compounds partially inhibited the chlamydial infection by reducing elementary body infectivity at high concentration. Our findings suggest the potential of pyrroloisoxazolidine derivatives as promising lead molecules for the development of antichlamydial agents.

scholarly journals A 2-pyridone amide inhibitor of transcriptional activity in Chlamydia trachomatis

2021 ◽  
Author(s):  
Carlos Núñez-Otero ◽  
Wael Bahnan ◽  
Katarina Vielfort ◽  
Jim Silver ◽  
Pardeep Singh ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Treatment Options ◽  
Normal Growth ◽  
Resistant Bacteria ◽  
Developmental Cycle ◽  
Rnase Iii ◽  
Antibiotic Resistant ◽  
Sexually Transmitted ◽  
Commensal Flora ◽  
Reticulate Body

Chlamydia trachomatis is a strict intracellular bacterium that causes sexually transmitted infections and eye infections that can lead to life-long sequelae. Treatment options are limited to broad-spectrum antibiotics that disturb the commensal flora and contribute to selection of antibiotic-resistant bacteria. Hence, development of novel drugs that specifically target C. trachomatis would be beneficial. 2-pyridone amides are potent and specific inhibitors of Chlamydia infectivity. The first generation compound KSK120, inhibits the developmental cycle of Chlamydia resulting in reduced infectivity of progeny bacteria. Here, we show that the improved, highly potent second-generation 2-pyridone amide KSK213 allowed normal growth and development of C. trachomatis and the effect was only observable upon re-infection of new cells. Progeny elementary bodies (EBs) produced in the presence of KSK213 were unable to activate transcription of essential genes in early development and did not differentiate into the replicative form, the reticulate body (RB). The effect was specific to C. trachomatis since KSK213 was inactive in the closely related animal pathogen C. muridarum and in C. caviae. The molecular target of KSK213 may thus be different in C. trachomatis or non-essential in C. muridarum and C. caviae. Resistance to KSK213 was mediated by a combination of amino acid substitutions in both DEAD/DEAH RNA helicase and RNAse III, which may indicate inhibition of the transcriptional machinery as the mode of action. 2-pyridone amides provide a novel antibacterial strategy and starting points for development of highly specific drugs for C. trachomatis infections.

scholarly journals Cell Type Development in Chlamydia trachomatis Follows a Program Intrinsic to the Reticulate Body

2020 ◽  
Author(s):  
Travis J Chiarelli ◽  
Nicole A Grieshaber ◽  
Anders Omsland ◽  
Christopher H Remien ◽  
Scott S Grieshaber
Keyword(s):  
Cell Division ◽  
Chlamydia Trachomatis ◽  
Mathematical Models ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Developmental Cycle ◽  
Cell Type ◽  
Obligate Intracellular ◽  
Reticulate Body ◽  
A Cell

AbstractThe obligate intracellular bacterial pathogen Chlamydia trachomatis (Ctr) is reliant on an unusual developmental cycle consisting of two cell forms termed the elementary body (EB) and the reticulate body (RB). The EB is infectious and utilizes a type III secretion system and preformed effector proteins during invasion, but does not replicate. The RB replicates in the host cell but is non-infectious. This developmental cycle is central to chlamydial pathogenesis. In this study we developed mathematical models of the chlamydial developmental cycle that account for potential factors influencing the timing of RB to EB cell type switching during infection. Our models predicted that two broad categories of regulatory signals for RB to EB development could be differentiated experimentally; an “intrinsic” cell autonomous program inherent to each RB or an “extrinsic” environmental signal to which RBs respond. To experimentally differentiate between these hypotheses, we tracked the expression of Ctr developmental specific promoters using fluorescent reporters and live cell imaging. These experiments indicated that EB production was not influenced by increased MOI or by superinfection, suggesting the cycle follows an intrinsic program that is not influenced by environmental factors. Additionally, live cell imaging of these promoter constructs revealed that EB development is a multistep process linked to RB growth rate and cell division. The formation of EBs followed a cell type gene expression progression with the promoters for euo and ihtA active in RBs, while the promoter for hctA was active in early EBs/intermediate cells and finally the promoters for the true late genes, hctB, scc2, and tarp active in the maturing EB.ImportanceChlamydia trachomatis is an obligate intracellular bacteria that can cause trachoma, cervicitis, urethritis, salpingitis, and pelvic inflammatory disease. To establish infection in host cells Chlamydia must complete a multi cell type developmental cycle. The developmental cycle consists of two specialized cells; the EB which mediates infection of new cells and the RB which replicates and eventually produces more EB cells to mediate the next round of infection. By developing and testing mathematical models to discriminate between two competing hypotheses for the nature of the signal controlling RB to EB cell type switching. We demonstrate that RB to EB development follows a cell autonomous program that does not respond to environmental cues. Additionally, we show that RB to EB development is a function of cell growth and cell division. This study serves to further our understanding of the chlamydial developmental cycle that is central to the bacterium’s pathogenesis.

scholarly journals The effect of penicillin on Chlamydia trachomatis DNA replication

Microbiology ◽  
2006 ◽  
Vol 152 (9) ◽  
pp. 2573-2578 ◽  
Author(s):  
Paul R. Lambden ◽  
Mark A. Pickett ◽  
Ian N. Clarke
Keyword(s):  
Dna Replication ◽  
Chlamydia Trachomatis ◽  
Plasmid Dna ◽  
Host Cells ◽  
Developmental Cycle ◽  
Chromosomal Dna ◽  
Rapid Phase ◽  
Reticulate Body ◽  
Transmission Electron ◽  
Infected Cells

Chlamydia trachomatis L2 was used to infect BGMK cells at an m.o.i. of 1.0, and the developmental cycle was followed by transmission electron microscopy and quantitative PCR (QPCR) for both chromosomal and plasmid DNA. Samples were taken at sequential 6 h time points. Subsequent analysis by QPCR showed that there was an initial slow replication period (0–18 h), followed by a rapid phase (18–36 h) coinciding with exponential division when the DNA doubling time was 4.6 h. Chromosomal DNA was amplified 100–200-fold corresponding to 7–8 generations for the complete developmental cycle. Penicillin (10 and 100 units ml−1) was added to cultures at 20 h post-infection (p.i.). This blocked binary fission and also prevented reticulate body (RB) to elementary body transition. However, exposure to penicillin did not prevent chromosomal or plasmid DNA replication. After a short lag period, following the addition of penicillin, chlamydial chromosomal DNA replication resumed at the same rate as in control C. trachomatis-infected cells. C. trachomatis-infected host cells exposed to penicillin did not lyse, but instead harboured large, aberrant RBs in massive inclusions that completely filled the cell cytoplasm. In these RBs, the DNA continued to replicate well beyond the end of the normal developmental cycle. At 60 h p.i. each aberrant RB contained a minimum of 16 chromosomal copies.

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