Ultrastructural analysis of the effects of erythromycin on the morphology and developmental cycle of Chlamydia trachomatis HAR-13

1982 ◽  
Vol 133 (4) ◽  
pp. 278-282 ◽  
Author(s):  
Richard B. Clark ◽  
Peter F. Schatzki ◽  
Harry P. Dalton
Keyword(s):  
Chlamydia Trachomatis ◽  
Ultrastructural Analysis ◽  
Developmental Cycle

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 Quantitative Monitoring of the Chlamydia trachomatis Developmental Cycle Using GFP-Expressing Bacteria, Microscopy and Flow Cytometry

PLoS ONE ◽  
2014 ◽  
Vol 9 (6) ◽  
pp. e99197 ◽  
Author(s):  
François Vromman ◽  
Marc Laverrière ◽  
Stéphanie Perrinet ◽  
Alexandre Dufour ◽  
Agathe Subtil
Keyword(s):  
Flow Cytometry ◽  
Chlamydia Trachomatis ◽  
Developmental Cycle ◽  
Quantitative Monitoring

scholarly journals Transcriptional Expression of the ompA, cpaf, tarp, and tox Genes of Chlamydia trachomatis Clinical Isolates at Different Stages of the Developmental Cycle

2019 ◽  
Vol 7 (6) ◽  
pp. 153 ◽  
Author(s):  
Suvi Korhonen ◽  
Kati Hokynar ◽  
Laura Mannonen ◽  
Jorma Paavonen ◽  
Eija Hiltunen-Back ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chlamydia Trachomatis ◽  
Cultured Cells ◽  
Expression Patterns ◽  
Clinical Isolates ◽  
Gene Expression Patterns ◽  
Developmental Cycle ◽  
Passage Number ◽  
Low Passage ◽  
Reference Strains

The transcriptional gene expression patterns of Chlamydia trachomatis have mainly been studied using reference strains propagated in cultured cells. Here, using five low-passage-number C. trachomatis clinical isolates that originated from asymptomatic or symptomatic female patients, the in vitro expression of the ompA, cpaf, tarp, and tox genes was studied with reverse transcriptase real-time PCR during the chlamydial developmental cycle. We observed dissimilarities in the gene expression patterns between the low-passage-number clinical isolates and the reference strains. The expression of ompA and the peak of the tox expression were observed earlier in the reference strains than in most of the clinical isolates. The expression of cpaf was high in the reference strains compared with the clinical isolates at the mid-phase (6–24 hours post infection) of the developmental cycle. All of the strains had a rather similar tarp expression profile. Four out of five clinical isolates exhibited slower growth kinetics compared with the reference strains. The use of low-passage-number C. trachomatis clinical isolates instead of reference strains in the studies might better reflect the situation in human infection.

scholarly journals Expression, Processing, and Localization of PmpD of Chlamydia trachomatis Serovar L2 during the Chlamydial Developmental Cycle

PLoS ONE ◽  
2007 ◽  
Vol 2 (6) ◽  
pp. e568 ◽  
Author(s):  
Andrey O. Kiselev ◽  
Walter E. Stamm ◽  
John R. Yates ◽  
Mary F. Lampe
Keyword(s):  
Chlamydia Trachomatis ◽  
Developmental Cycle ◽  
Expression Processing

scholarly journals Characterization of Outer Membrane Proteins in Chlamydia trachomatis LGV Serovar L2

2001 ◽  
Vol 183 (8) ◽  
pp. 2686-2690 ◽  
Author(s):  
Regina J. Tanzer ◽  
Thomas P. Hatch
Keyword(s):  
Chlamydia Trachomatis ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Outer Membrane ◽  
Outer Membrane Protein ◽  
Outer Membrane Proteins ◽  
Major Outer Membrane Protein ◽  
Developmental Cycle ◽  
Reading Frame

ABSTRACT We used a photoactivatable, lipophilic reagent, 3′-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine, to label proteins in the outer membrane of elementary bodies ofChlamydia trachomatis LGV serovar L2 and mass spectrometry to identify the labeled proteins. The identified proteins were polymorphic outer membrane proteins E, G, and H, which were made late in the developmental cycle, the major outer membrane protein, and a mixture of 46-kDa proteins consisting of the open reading frame 623 protein and possibly a modified form of the major outer membrane protein.

scholarly journals Role for GrgA in Regulation of σ28-Dependent Transcription in the Obligate Intracellular Bacterial PathogenChlamydia trachomatis

2018 ◽  
Vol 200 (20) ◽  
Author(s):  
Malhar Desai ◽  
Wurihan Wurihan ◽  
Rong Di ◽  
Joseph D. Fondell ◽  
Bryce E. Nickels ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Chlamydia Trachomatis ◽  
Sigma Factor ◽  
Bacterial Pathogen ◽  
Direct Interaction ◽  
Developmental Cycle ◽  
Content Type ◽  
Sexually Transmitted ◽  
Obligate Intracellular ◽  
Specific Transcription Factor

ABSTRACTThe obligate intracellular bacterial pathogenChlamydia trachomatishas a unique developmental cycle consisting of two contrasting cellular forms. Whereas the primaryChlamydiasigma factor, σ66, is involved in the expression of the majority of chlamydial genes throughout the developmental cycle, expression of several late genes requires the alternative sigma factor, σ28. In prior work, we identified GrgA as aChlamydia-specific transcription factor that activates σ66-dependent transcription by binding DNA and interacting with a nonconserved region (NCR) of σ66. Here, we extend these findings by showing GrgA can also activate σ28-dependent transcription through direct interaction with σ28. We measure the binding affinity of GrgA for both σ66and σ28, and we identify regions of GrgA important for σ28-dependent transcription. Similar to results obtained with σ66, we find that GrgA's interaction with σ28involves an NCR located upstream of conserved region 2 of σ28. Our findings suggest that GrgA is an important regulator of both σ66- and σ28-dependent transcription inC. trachomatisand further highlight NCRs of bacterial RNA polymerase as targets for regulatory factors unique to particular organisms.IMPORTANCEChlamydia trachomatisis the number one sexually transmitted bacterial pathogen worldwide. A substantial proportion ofC. trachomatis-infected women develop infertility, pelvic inflammatory syndrome, and other serious complications.C. trachomatisis also a leading infectious cause of blindness in underdeveloped countries. The pathogen has a unique developmental cycle that is transcriptionally regulated. The discovery of an expanded role for theChlamydia-specific transcription factor GrgA helps us understand the progression of the chlamydial developmental cycle.

scholarly journals Interrogating Genes That Mediate Chlamydia trachomatis Survival in Cell Culture Using Conditional Mutants and Recombination

2016 ◽  
Vol 198 (15) ◽  
pp. 2131-2139 ◽  
Author(s):  
Julie A. Brothwell ◽  
Matthew K. Muramatsu ◽  
Evelyn Toh ◽  
Daniel D. Rockey ◽  
Timothy E. Putman ◽  
...  
Keyword(s):  
Cell Culture ◽  
Chlamydia Trachomatis ◽  
Genome Sequencing ◽  
Transmitted Disease ◽  
Temperature Shift ◽  
Open Reading Frames ◽  
Developmental Cycle ◽  
Temperature Sensitive ◽  
Genetic Dissection ◽  
Content Type

ABSTRACTIntracellular bacterial pathogens in the familyChlamydiaceaeare causes of human blindness, sexually transmitted disease, and pneumonia. Genetic dissection of the mechanisms of chlamydial pathogenicity has been hindered by multiple limitations, including the inability to inactivate genes that would prevent the production of elementary bodies. Many genes are alsoChlamydia-specific genes, and chlamydial genomes have undergone extensive reductive evolution, so functions often cannot be inferred from homologs in other organisms. Conditional mutants have been used to study essential genes of many microorganisms, so we screened a library of 4,184 ethyl methanesulfonate-mutagenizedChlamydia trachomatisisolates for temperature-sensitive (TS) mutants that developed normally at physiological temperature (37°C) but not at nonphysiological temperatures. Heat-sensitive TS mutants were identified at a high frequency, while cold-sensitive mutants were less common. Twelve TS mutants were mapped using a novel markerless recombination approach, PCR, and genome sequencing. TS alleles of genes that play essential roles in other bacteria and chlamydia-specific open reading frames (ORFs) of unknown function were identified. Temperature-shift assays determined that phenotypes of the mutants manifested at distinct points in the developmental cycle. Genome sequencing of a larger population of TS mutants also revealed that the screen had not reached saturation. In summary, we describe the first approach for studying essential chlamydial genes and broadly applicable strategies for genetic mapping inChlamydiaspp. and mutants that both define checkpoints and provide insights into the biology of the chlamydial developmental cycle.IMPORTANCEStudy of the pathogenesis ofChlamydiaspp. has historically been hampered by a lack of genetic tools. Although there has been recent progress in chlamydial genetics, the existing approaches have limitations for the study of the genes that mediate growth of these organisms in cell culture. We used a genetic screen to identify conditionalChlamydiamutants and then mapped these alleles using a broadly applicable recombination strategy. Phenotypes of the mutants provide fundamental insights into unexplored areas of chlamydial pathogenesis and intracellular biology. Finally, the reagents and approaches we describe are powerful resources for the investigation of these organisms.

scholarly journals Translational gene expression control in Chlamydia trachomatis.

2021 ◽  
Author(s):  
Nicole A Grieshaber ◽  
Travis J Chiarelli ◽  
Cody R Appa ◽  
Grace Neiswanger ◽  
Kristina Peretti ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chlamydia Trachomatis ◽  
Translational Control ◽  
Regulatory Protein ◽  
Inducible Promoter ◽  
Cloning And Expression ◽  
Developmental Cycle ◽  
Expression Control ◽  
Gene Expression Control ◽  
Wide Range

The human pathogen Chlamydia trachomatis proceeds through a multi phenotypic developmental cycle with each cell form specialized for different roles in pathogenesis. Understanding the mechanisms regulating this complex cycle has historically been hampered by limited genetic tools. In an effort to address this issue, we developed a translational control system to regulate gene expression in Chlamydia using a synthetic riboswitch. Here we demonstrate that translational control via a riboswitch can be used in combination with a wide range of promoters in C. trachomatis. The synthetic riboswitch E, inducible with theophylline, was used to replace the ribosome binding site of the synthetic promoter T5-lac, the native chlamydial promoter of the pgp4plasmid gene and an anhydrotetracycline responsive promoter. In all cases the riboswitch inhibited translation, and high levels of protein expression was induced with theophylline. Combining the Tet transcriptional inducible promoter with the translational control of the riboswitch resulted in strong repression and allowed for the cloning and expression of the potent chlamydial regulatory protein, HctB. The ability to control the timing and strength of gene expression independently from promoter specificity is a new and important tool for studying chlamydial regulatory and virulence genes.

scholarly journals Stochastic modelling of chlamydial infections

2020 ◽  
Vol 61 ◽  
pp. C89-C103
Author(s):  
Torrington Callan ◽  
Stephen Woodcock
Keyword(s):  
Mathematical Model ◽  
Immune Response ◽  
Chlamydia Trachomatis ◽  
Chlamydial Infection ◽  
Branching Processes ◽  
Stochastic Modelling ◽  
Cell Aggregation ◽  
Computational Techniques ◽  
Developmental Cycle ◽  
Ascending Infection

Chlamydia trachomatis is a bacterial pathogen that can cause serious reproductive harm. We describe a class of stochastic branching processes and their application in modelling the growth of an infection by Chlamydia. Using simulations we show that the model can reproduce biological phenomena of interest, and we show the variability in outcomes of infections under the same parameter conditions. We further speculate how this model might be used to explain long-term adverse reproductive sequelae. References Y. M. AbdelRahman and R. J. Belland. The chlamydial developmental cycle. FEMS Microbio. Rev., 29(5):949–959, 2005. doi:10.1016/j.femsre.2005.03.002. T. E. Harris. Branching processes. Ann. Math. Stat., 19(4):474–494, 12 1948. doi:10.1214/aoms/1177730146. C. Jacob. Branching processes: Their role in epidemiology. Int. J. Env. Res. Public Health, 7(3):1186–1204, 2019. doi:10.3390/ijerph7031204. N. Low, M. Egger, J. A. C. Sterne, R. M. Harbord, F. Ibrahim, B. Lindblom, and B. Herrmann. Incidence of severe reproductive tract complications associated with diagnosed genital chlamydial infection: The Uppsala women's cohort study. Sexually Trans. Infect., 82(3):212–218, 2006. doi:10.1136/sti.2005.017186. D. Mallet, M. Bagher-Oskouei, A. Farr, D. Simpson, and K. Sutton. A mathematical model of chlamydial infection incorporating movement of chlamydial particles. Bull. Math. Bio., 75:2257–2270, 10 2013. doi:10.1007/s11538-013-9891-9. H. K. Maxion, W. Liu, M.-H. Chang, and K. A. Kelly. The infecting dose of chlamydia muridarum modulates the innate immune response and ascending infection. Infect. Immun., 72(11):6330–6340, 2004. doi:10.1128/IAI.72.11.6330-6340.2004. S. Menon, P. Timms, J. A. Allan, K. Alexander, L. Rombauts, P. Horner, M. Keltz, J. Hocking, and W. M. Huston. Human and pathogen factors associated with chlamydia trachomatis-related infertility in women. Clinic. Microbio. Rev., 28(4):969–985, 2015. doi:10.1128/CMR.00035-15. D. P. Wilson. Mathematical modelling of chlamydia. In J. Crawford and A. J. Roberts, editors, Proc. of 11th Computational Techniques and Applications Conference CTAC-2003, ANZIAM J., volume 45, pages C201–C214, 2004. doi:10.21914/anziamj.v45i0.883. D. P. Wilson and D. L. S. McElwain. A model of neutralization of chlamydia trachomatis based on antibody and host cell aggregation on the elementary body surface. J. Theor. Bio., 226(3):321–330, 2004. doi:10.1016/j.jtbi.2003.09.010. D. P. Wilson, P. Timms, and D. L. S. McElwain. A mathematical model for the investigation of the Th1 immune response to chlamydia trachomatis. Math. Biosci., 182(1):27–44, 2003. doi:10.1016/S0025-5564(02)00180-3.

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