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 Extragenital Screening Is Essential for Comprehensive Detection of Chlamydia trachomatis and Neisseria gonorrhoeae in the Pediatric Population

2019 ◽  
Vol 57 (6) ◽  
Author(s):  
Priyanka Uprety ◽  
Ana María Cárdenas
Keyword(s):  
Chlamydia Trachomatis ◽  
Neisseria Gonorrhoeae ◽  
Diagnostic Yield ◽  
Pediatric Population ◽  
Transmitted Disease ◽  
Age Groups ◽  
The United States ◽  
Anatomic Site ◽  
Data Set ◽  
Content Type

ABSTRACT Chlamydia trachomatis and Neisseria gonorrhoeae are the two most common causes of sexually transmitted disease in the United States. Studies in adults, mostly in men who have sex with men, have shown that the prevalence of C. trachomatis and N. gonorrhoeae infections is much higher in extragenital sources compared to urogenital sources. A similar large sample of data on the burden of C. trachomatis and N. gonorrhoeae infections by anatomic site is lacking in children. We retrospectively analyzed data from 655 patients tested for C. trachomatis (887 specimens) and N. gonorrhoeae (890 specimens) at the Children’s Hospital of Philadelphia. We restricted the analysis to include patients between 2 and 17 years of age that had all three sources (urine, oropharynx, and rectum) collected at the same visit. The final data set included specimens from all three sources from 148 and 154 patients for C. trachomatis and N. gonorrhoeae, respectively. Specimens were tested for C. trachomatis and N. gonorrhoeae using a Gen-Probe Aptima Combo 2 assay. The burden of C. trachomatis and N. gonorrhoeae infection was significantly higher in the 14- to 17-year age group (24.7%, P = 0.041; 25.8%; P = 0.001) compared to the 10- to 13-year (5.9%; 5.6%), 6- to 9-year (4.6%; 4.6%), and 2- to 5-year (8.3%; 0%) age groups, respectively. The positivity rate for C. trachomatis was highest for rectal (16.2%), followed by urine (5.4%) and oropharyngeal (0.7%) sites. The positivity rate for N. gonorrhoeae was highest for rectal sites (10.4%), followed by oropharyngeal (9.7%) and urine (1.9%) sites. The source with highest diagnostic yield is rectum for C. trachomatis and rectum and oropharynx for N. gonorrhoeae. Hence, extragenital screening is critical for the comprehensive detection of C. trachomatis and N. gonorrhoeae in the pediatric population.

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 Evaluation of the Biostar Chlamydia OIA Assay with Specimens from Women Attending a Sexually Transmitted Disease Clinic

1998 ◽  
Vol 36 (8) ◽  
pp. 2183-2186 ◽  
Author(s):  
Mitchell S. Pate ◽  
Paula B. Dixon ◽  
Kim Hardy ◽  
Mark Crosby ◽  
E. W. Hook
Keyword(s):  
Cell Culture ◽  
Chlamydia Trachomatis ◽  
Fluorescent Antibody ◽  
Transmitted Disease ◽  
The United States ◽  
Chlamydia Screening ◽  
Test Results ◽  
Screening Assay ◽  
Predictive Values ◽  
Sexually Transmitted

Chlamydia trachomatis infections are the most prevalent sexually transmitted diseases (STDs) in the United States. In acute-care settings such as clinics and emergency rooms, a desirable chlamydia screening assay should exhibit good sensitivity and good specificity and should provide test results while the patient is still present. The Biostar Chlamydia OIA (Biostar, Inc., Boulder, Colo.) is an optical immunoassay (OIA) that provides test results in less than 30 min and that uses a test format that allows office-based testing. This assay is performed entirely at room temperature without the need for rotators or other specialized equipment. The goal of this study was to compare the performance of the Biostar Chlamydia OIA for the detection of C. trachomatis with the performance of cell culture, direct fluorescent-antibody (DFA) assay (Syva MicroTrak; Syva Co., Palo Alto, Calif.), and PCR (Roche Amplicor Chlamydia trachomatis; Roche, Branchburg, N.J.) for the detection ofC. trachomatis infections in women attending an urban STD clinic. For calculations of relative test performance (sensitivity, specificity, and positive and negative predictive values), patient specimens that yielded positive results by two or more of the four assays (cell culture, DFA assay, PCR, and OIA) were classified as “true infections.” By these criteria, 42 of 306 total specimens were classified as positive for C. trachomatis (positive prevalence, 13.7%), 11 (3.6%; 10 by PCR and 1 by DFA assay) were positive by a single assay, and 253 (82.7%) were negative by all four tests. All culture-positive specimens were also positive by at least one other assay. Among the culture-negative specimens, 14 (5%) specimens were positive by two of the three non-culture-based assays used. By using the criterion that positivity by at least two of the tests indicated a true infection, the relative sensitivities were as follows: culture and PCR, 92.9% each; Biostar Chlamydia OIA, 73.8%; and DFA assay, 59.5%.

scholarly journals Animal Models for Studying Female Genital Tract Infection with Chlamydia trachomatis

2013 ◽  
Vol 81 (9) ◽  
pp. 3060-3067 ◽  
Author(s):  
Evelien De Clercq ◽  
Isabelle Kalmar ◽  
Daisy Vanrompay
Keyword(s):  
Chlamydia Trachomatis ◽  
Animal Models ◽  
Genital Tract ◽  
Transmitted Disease ◽  
Female Genital Tract ◽  
Genital Tract Infection ◽  
Content Type ◽  
Genital Tract Infections ◽  
Tract Infections ◽  
Female Genital

ABSTRACTChlamydia trachomatisis a Gram-negative obligate intracellular bacterial pathogen. It is the leading cause of bacterial sexually transmitted disease in the world, with more than 100 million new cases of genital tract infections withC. trachomatisoccurring each year. Animal models are indispensable for the study ofC. trachomatisinfections and the development and evaluation of candidate vaccines. In this paper, the most commonly used animal models to study female genital tract infections withC. trachomatiswill be reviewed, namely, the mouse, guinea pig, and nonhuman primate models. Additionally, we will focus on the more recently developed pig model.

scholarly journals Inhibition of Indoleamine 2,3-Dioxygenase Activity by Levo-1-Methyl Tryptophan Blocks Gamma Interferon-Induced Chlamydia trachomatis Persistence in Human Epithelial Cells

2011 ◽  
Vol 79 (11) ◽  
pp. 4425-4437 ◽  
Author(s):  
Joyce A. Ibana ◽  
Robert J. Belland ◽  
Arnold H. Zea ◽  
Danny J. Schust ◽  
Takeshi Nagamatsu ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Epithelial Cells ◽  
Gamma Interferon ◽  
Developmental Cycle ◽  
Tryptophan Depletion ◽  
Content Type ◽  
Indoleamine 2,3 Dioxygenase ◽  
Human Epithelial Cells ◽  
Ifn Γ

ABSTRACTGamma interferon (IFN-γ) induces expression of the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO1) in human epithelial cells, the permissive cells for the obligate intracellular bacteriumChlamydia trachomatis. IDO1 depletes tryptophan by catabolizing it to kynurenine with consequences forC. trachomatis, which is a tryptophan auxotroph.In vitrostudies reveal that tryptophan depletion can result in the formation of persistent (viable but noncultivable) chlamydial forms. Here, we tested the effects of the IDO1 inhibitor, levo-1-methyl-tryptophan (L-1MT), on IFN-γ-inducedC. trachomatispersistence. We found that addition of 0.2 mM L-1MT to IFN-γ-exposed infected HeLa cell cultures restricted IDO1 activity at the mid-stage (20 h postinfection [hpi]) of the chlamydial developmental cycle. This delayed tryptophan depletion until the late stage (38 hpi) of the cycle. Parallel morphological and gene expression studies indicated a consequence of the delay was a block in the induction ofC. trachomatispersistence by IFN-γ. Furthermore, L-1MT addition allowedC. trachomatisto undergo secondary differentiation, albeit with limited productive multiplication of the bacterium. IFN-γ-induced persistent infections in epithelial cells have been previously reported to be more resistant to doxycycline than normal productive infectionsin vitro. Pertinent to this observation, we found that L-1MT significantly improved the efficacy of doxycycline in clearing persistentC. trachomatisforms. It has been postulated that persistent forms ofC. trachomatismay contribute to chronic chlamydial disease. Our findings suggest that IDO1 inhibitors such as L-1MT might provide a novel means to investigate, and potentially target, persistent chlamydial forms, particularly in conjunction with conventional therapeutics.

scholarly journals Single-Inclusion Kinetics of Chlamydia trachomatis Development

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Travis J. Chiarelli ◽  
Nicole A. Grieshaber ◽  
Anders Omsland ◽  
Christopher H. Remien ◽  
Scott S. Grieshaber
Keyword(s):  
Chlamydia Trachomatis ◽  
Mathematical Models ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Host Cells ◽  
Developmental Cycle ◽  
Cell Type ◽  
Content Type ◽  
Obligate Intracellular

ABSTRACT The obligate intracellular bacterial pathogen Chlamydia trachomatis is reliant on a 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 it does not replicate. The RB replicates in the host cell but is noninfectious. This developmental cycle is central to chlamydial pathogenesis. In this study, we developed mathematical models of the developmental cycle that account for potential factors influencing RB-to-EB cell type switching during infection. Our models predicted that two categories of regulatory signals for RB-to-EB development could be differentiated experimentally, an “intrinsic” cell-autonomous program inherent to each RB and an “extrinsic” environmental signal to which RBs respond. To experimentally differentiate between mechanisms, we tracked the expression of C. trachomatis development-specific promoters in individual inclusions using fluorescent reporters and live-cell imaging. These experiments indicated that EB production was not influenced by increased multiplicity of infection or by superinfection, suggesting the cycle follows an intrinsic program that is not directly controlled by environmental factors. Additionally, live-cell imaging revealed that EB development is a multistep process linked to RB growth rate and cell division. The formation of EBs followed a progression with expression from the euo and ihtA promoters evident in RBs, while expression from the promoter for hctA was apparent in early EBs/IBs. Finally, expression from the promoters for the true late genes, hctB, scc2, and tarp, was evident in the maturing EB. IMPORTANCE Chlamydia trachomatis is an obligate intracellular bacterium that can cause trachoma, cervicitis, urethritis, salpingitis, and pelvic inflammatory disease. To establish infection in host cells, Chlamydia must complete a multiple-cell-type developmental cycle. The developmental cycle consists of specialized cells, the EB cell, which mediates infection of new host cells, and the RB cell, 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 chlamydial growth and division. This study serves to further our understanding of the chlamydial developmental cycle that is central to the bacterium’s pathogenesis.

scholarly journals Ongoing evolution of Chlamydia trachomatis lymphogranuloma venereum: exploring the genomic diversity of circulating strains

2021 ◽  
Vol 7 (6) ◽  
Author(s):  
Helena M. B. Seth-Smith ◽  
Angèle Bénard ◽  
Sylvia M. Bruisten ◽  
Bart Versteeg ◽  
Björn Herrmann ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Genome Sequencing ◽  
Lymphogranuloma Venereum ◽  
Genomic Diversity ◽  
Invasive Infection ◽  
Content Type ◽  
Genomic Changes ◽  
Variable Domains ◽  
Sex With Men ◽  
Sexually Transmissible Infection

Lymphogranuloma venereum (LGV), the invasive infection of the sexually transmissible infection (STI) Chlamydia trachomatis , is caused by strains from the LGV biovar, most commonly represented by ompA-genotypes L2b and L2. We investigated the diversity in LGV samples across an international collection over seven years using typing and genome sequencing. LGV-positive samples (n=321) from eight countries collected between 2011 and 2017 (Spain n=97, Netherlands n=67, Switzerland n=64, Australia n=53, Sweden n=37, Hungary n=31, Czechia n=30, Slovenia n=10) were genotyped for pmpH and ompA variants. All were found to contain the 9 bp insertion in the pmpH gene, previously associated with ompA-genotype L2b. However, analysis of the ompA gene shows ompA-genotype L2b (n=83), ompA-genotype L2 (n=180) and several variants of these (n=52; 12 variant types), as well as other/mixed ompA-genotypes (n=6). To elucidate the genomic diversity, whole genome sequencing (WGS) was performed from selected samples using SureSelect target enrichment, resulting in 42 genomes, covering a diversity of ompA-genotypes and representing most of the countries sampled. A phylogeny of these data clearly shows that these ompA-genotypes derive from an ompA-genotype L2b ancestor, carrying up to eight SNPs per isolate. SNPs within ompA are overrepresented among genomic changes in these samples, each of which results in an amino acid change in the variable domains of OmpA (major outer membrane protein, MOMP). A reversion to ompA-genotype L2 with the L2b genomic backbone is commonly seen. The wide diversity of ompA-genotypes found in these recent LGV samples indicates that this gene is under immunological selection. Our results suggest that the ompA-genotype L2b genomic backbone is the dominant strain circulating and evolving particularly in men who have sex with men (MSM) populations.

scholarly journals Neisseria gonorrhoeae clustering to reveal major European whole-genome-sequencing-based genogroups in association with antimicrobial resistance

2020 ◽  
Author(s):  
Miguel Pinto ◽  
Vítor Borges ◽  
Joana Isidro ◽  
João Carlos Rodrigues ◽  
Luís Vieira ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Neisseria Gonorrhoeae ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Type Species ◽  
Transmitted Disease ◽  
Epidemiological Surveillance ◽  
Whole Genome ◽  
Content Type ◽  
Link Type

Neisseria gonorrhoeae , the bacterium responsible for the sexually transmitted disease gonorrhoea, has shown an extraordinary ability to develop antimicrobial resistance (AMR) to multiple classes of antimicrobials. With no available vaccine, managing N. gonorrhoeae infections demands effective preventive measures, antibiotic treatment and epidemiological surveillance. The latter two are progressively being supported by the generation of whole-genome sequencing (WGS) data on behalf of national and international surveillance programmes. In this context, this study aims to perform N. gonorrhoeae clustering into genogroups based on WGS data, for enhanced prospective laboratory surveillance. Particularly, it aims to identify the major circulating WGS-genogroups in Europe and to establish a relationship between these and AMR. Ultimately, it enriches public databases by contributing with WGS data from Portuguese isolates spanning 15 years of surveillance. A total of 3791 carefully inspected N. gonorrhoeae genomes from isolates collected across Europe were analysed using a gene-by-gene approach (i.e. using cgMLST). Analysis of cluster composition and stability allowed the classification of isolates into a two-step hierarchical genogroup level determined by two allelic distance thresholds revealing cluster stability. Genogroup clustering in general agreed with available N. gonorrhoeae typing methods [i.e. MLST (multilocus sequence typing), NG-MAST ( N. gonorrhoeae multi-antigen sequence typing) and PubMLST core-genome groups], highlighting the predominant genogroups circulating in Europe, and revealed that the vast majority of the genogroups present a dominant AMR profile. Additionally, a non-static gene-by-gene approach combined with a more discriminatory threshold for potential epidemiological linkage enabled us to match data with previous reports on outbreaks or transmission chains. In conclusion, this genogroup assignment allows a comprehensive analysis of N. gonorrhoeae genetic diversity and the identification of the WGS-based genogroups circulating in Europe, while facilitating the assessment (and continuous monitoring) of their frequency, geographical dispersion and potential association with specific AMR signatures. This strategy may benefit public-health actions through the prioritization of genogroups to be controlled, the identification of emerging resistance carriage, and the potential facilitation of data sharing and communication.

scholarly journals Septins Arrange F-Actin-Containing Fibers on the Chlamydia trachomatis Inclusion and Are Required for Normal Release of the Inclusion by Extrusion

mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Larisa Volceanov ◽  
Katharina Herbst ◽  
Martin Biniossek ◽  
Oliver Schilling ◽  
Dirk Haller ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Mammalian Cells ◽  
Binding Proteins ◽  
Higher Order ◽  
Host Cells ◽  
Developmental Cycle ◽  
Content Type ◽  
Gtp Binding Proteins ◽  
Gtp Binding ◽  
Chlamydial Inclusion

ABSTRACTChlamydia trachomatisis an obligate intracellular human pathogen that grows inside a membranous, cytosolic vacuole termed an inclusion. Septins are a group of 13 GTP-binding proteins that assemble into oligomeric complexes and that can form higher-order filaments. We report here that the septins SEPT2, -9, -11, and probably -7 form fibrillar structures around the chlamydial inclusion. Colocalization studies suggest that these septins combine with F actin into fibers that encase the inclusion. Targeting the expression of individual septins by RNA interference (RNAi) prevented the formation of septin fibers as well as the recruitment of actin to the inclusion. At the end of the developmental cycle ofC. trachomatis, newly formed, infectious elementary bodies are released, and this release occurs at least in part through the organized extrusion of intact inclusions. RNAi against SEPT9 or against the combination of SEPT2/7/9 substantially reduced the number of extrusions from a culture of infected HeLa cells. The data suggest that a higher-order structure of four septins is involved in the recruitment or stabilization of the actin coat around the chlamydial inclusion and that this actin recruitment by septins is instrumental for the coordinated egress ofC. trachomatisfrom human cells. The organization of F actin around parasite-containing vacuoles may be a broader response mechanism of mammalian cells to the infection by intracellular, vacuole-dwelling pathogens.IMPORTANCEChlamydia trachomatisis a frequent bacterial pathogen throughout the world, causing mostly eye and genital infections.C. trachomatiscan develop only inside host cells; it multiplies inside a membranous vacuole in the cytosol, termed an inclusion. The inclusion is covered by cytoskeletal “coats” or “cages,” whose organization and function are poorly understood. We here report that a relatively little-characterized group of proteins, septins, is required to organize actin fibers on the inclusion and probably through actin the release of the inclusion. Septins are a group of GTP-binding proteins that can organize into heteromeric complexes and then into large filaments. Septins have previously been found to be involved in the interaction of the cell with bacteria in the cytosol. Our observation that they also organize a reaction to bacteria living in vacuoles suggests that they have a function in the recognition of foreign compartments by a parasitized human cell.

scholarly journals Host and Bacterial Glycolysis during Chlamydia trachomatis Infection

2020 ◽  
Vol 88 (12) ◽  
Author(s):  
Rachel J. Ende ◽  
Isabelle Derré
Keyword(s):  
Chlamydia Trachomatis ◽  
Host Cell ◽  
Time Course ◽  
Glycolytic Enzyme ◽  
Glycolytic Enzymes ◽  
Pcr Analysis ◽  
Developmental Cycle ◽  
Transmitted Infection ◽  
Content Type ◽  
Aldolase A

ABSTRACT The obligate intracellular pathogen Chlamydia trachomatis is the leading cause of noncongenital blindness and causative agent of the most common sexually transmitted infection of bacterial origin. With a reduced genome, C. trachomatis is dependent on its host for survival, in part due to a need for the host cell to compensate for incomplete bacterial metabolic pathways. However, relatively little is known regarding how C. trachomatis is able to hijack host cell metabolism. In this study, we show that two host glycolytic enzymes, aldolase A and pyruvate kinase, as well as lactate dehydrogenase, are enriched at the C. trachomatis inclusion membrane during infection. Inclusion localization was not species specific, since a similar phenotype was observed with C. muridarum. Time course experiments showed that the number of positive inclusions increased throughout the developmental cycle. In addition, these host enzymes colocalized to the same inclusion, and their localization did not appear to be dependent on sustained bacterial protein synthesis or on intact host actin, vesicular trafficking, or microtubules. Depletion of the host glycolytic enzyme aldolase A resulted in decreased inclusion size and infectious progeny production, indicating a role for host glycolysis in bacterial growth. Finally, quantitative PCR analysis showed that expression of C. trachomatis glycolytic enzymes inversely correlated with host enzyme localization at the inclusion. We discuss potential mechanisms leading to inclusion localization of host glycolytic enzymes and how it could benefit the bacteria. Altogether, our findings provide further insight into the intricate relationship between host and bacterial metabolism during Chlamydia infection.

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