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1.
J Reprod Immunol ; 80(1-2): 49-56, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19361867

ABSTRACT

Chlamydophila abortus is a Gram-negative obligate intracellular bacterium that causes infectious abortion in sheep (ovine enzootic abortion, OEA) and humans. Infected placentas recovered from sheep that experience OEA have thickened membranes, contain dense inflammatory cellular infiltrates and show evidence of intravascular thrombosis. Despite widespread inflammation, chlamydial multiplication is restricted to the chorionic trophoblast cells. To investigate the potential role of trophoblast in the initiation and propagation of placental inflammation during OEA, the AH-1 ovine trophoblast cell line was experimentally infected with C. abortus and analysed for the release of pro-inflammatory mediators. C. abortus was found to induce the release of both tumour necrosis factor-alpha (TNFalpha) and CXCL8 (interleukin-8) from AH-1 cells in a dose- and time-dependent manner. Ultra-violet (UV)-killed organisms did not elicit this profile, indicating that intracellular multiplication of C. abortus was required for release of these pro-inflammatory mediators. Exposure of AH-1 cells to recombinant ovine TNFalpha alone resulted in the release of CXCL8, suggestive of a self-propagating inflammatory cytokine and chemokine cascade. These data indicate a primary role for trophoblast in the initiation and propagation of placental inflammation during chlamydial abortion.


Subject(s)
Abortion, Veterinary/immunology , Chlamydophila Infections/veterinary , Chlamydophila/immunology , Interleukin-8/metabolism , Pregnancy Complications, Infectious/veterinary , Trophoblasts/metabolism , Tumor Necrosis Factor-alpha/metabolism , Animals , Cell Line , Cell Proliferation , Chlamydophila/growth & development , Chlamydophila Infections/immunology , Chlamydophila Infections/pathology , Chlamydophila Infections/physiopathology , Dose-Response Relationship, Immunologic , Female , Homeostasis/immunology , Inflammation/immunology , Interleukin-8/genetics , Interleukin-8/immunology , Pregnancy , Pregnancy Complications, Infectious/immunology , Pregnancy Complications, Infectious/pathology , Pregnancy Complications, Infectious/physiopathology , Sheep , Thrombosis/immunology , Trophoblasts/immunology , Trophoblasts/microbiology , Trophoblasts/pathology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunology
2.
Virology ; 377(2): 440-5, 2008 Aug 01.
Article in English | MEDLINE | ID: mdl-18570973

ABSTRACT

Studying the replication of the chlamydiaphages presents significant challenges. Their host bacteria, chlamydiae, have a unique obligate intracellular developmental cycle. Using qPCR, immunochemistry, and electron microscopy, the life cycle of chlamydiaphage Chp2 was characterised. Chp2 infection has a dramatic inhibitory effect on bacterial cell division. The RB to EB transition is arrested and RBs enlarge without further division. There is a phase of rapid Chp2 genome replication 36 to 48 h post infection that is coincident with the expression of viral proteins and the replication of the host chromosome. The end stage of Chp2 replication is characterised by the appearance of paracrystalline structures followed by bacterial cell lysis. These data indicate that the Chp2 life cycle is closely coordinated with the developmental cycle of its bacterial host. This is a remarkable adaptation by a microvirus to infect and replicate in a bacterial host that has an obligate intracellular developmental cycle.


Subject(s)
Cell Cycle , Chlamydophila/virology , Microviridae/physiology , Cell Division , Cell Line , Chlamydophila/growth & development , DNA Replication , DNA, Viral/biosynthesis , Gene Expression Regulation, Bacterial , Microviridae/genetics
3.
J Bacteriol ; 189(13): 4957-9, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17468245

ABSTRACT

The obligate intracellular nature of chlamydiae presents challenges to the characterization of its phages, which are potential tools for a genetic transfer system. An assay for phage infectivity is described, and the infectious properties of phage Chp2 were determined.


Subject(s)
Chlamydophila/virology , Microviridae/growth & development , Animals , Bacterial Proteins/genetics , Cell Line , Chlamydophila/genetics , Chlamydophila/growth & development , Genome, Bacterial , Inclusion Bodies/ultrastructure , Microscopy, Electron, Transmission , Microviridae/ultrastructure , Polymerase Chain Reaction , Virion/growth & development , Virion/ultrastructure
4.
BMC Microbiol ; 4: 24, 2004 Jul 01.
Article in English | MEDLINE | ID: mdl-15230981

ABSTRACT

BACKGROUND: Chlamydiae produce a set of proteins, termed Inc proteins, that are localized to the inclusion membrane and exposed to the host cell cytosol. Little information exists regarding the interaction of Inc proteins with the eukaryotic cell. To examine these interactions, Vaccinia virus vectors and mammalian plasmid-based systems were used to express inc genes in mammalian cells. RESULTS: Cells transfected with plasmids expressing Chlamydophila caviae incA were not productively infected by C. caviae. Expression of C. caviae incA also reduced inclusion formation by Chlamydia trachomatis, but not to the degree seen for C. caviae. Chlamydia trachomatis incA did not block development of either C. trachomatis or C. caviae. Deletion mutagenesis was used to demonstrate that plasmids encoding either the amino or carboxy-terminal regions of the protein, as well as the changing of a single amino acid within IncA (serine 17) could not block C. caviae infection. Immunoblot analysis of truncated IncA in a Vaccinia virus system provided evidence that serine 17 of C. caviae IncA is a target for phosphorylation. CONCLUSIONS: These experiments provide insight into the interaction of Inc proteins with the host cell and introduce a model system where these interactions can be explored further.


Subject(s)
Bacterial Proteins/genetics , Chlamydophila/genetics , HeLa Cells/microbiology , Phosphoproteins/genetics , Animals , Bacterial Proteins/biosynthesis , CHO Cells , Cell Line , Cell Line, Tumor , Chlamydia trachomatis/genetics , Chlamydia trachomatis/growth & development , Chlamydophila/growth & development , Cricetinae , Cricetulus , Cytoplasm/chemistry , Cytoplasm/metabolism , Cytoplasm/microbiology , Genetic Vectors/biosynthesis , HeLa Cells/chemistry , HeLa Cells/metabolism , HeLa Cells/virology , Humans , Membrane Proteins/biosynthesis , Membrane Proteins/genetics , Models, Genetic , Phosphoproteins/biosynthesis , Transfection/methods , Vaccinia virus/genetics
5.
Emerg Infect Dis ; 9(12): 1642-4, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14720414

ABSTRACT

We report the first documented case of an extragestational infection with Chlamydophila abortus in humans. The pathogen was identified in a patient with severe pelvic inflammatory disease (PID) by sequence analysis of the ompA gene. Our findings raise the possibility that Chlamydiaceae other than Chlamydia trachomatis are involved in PID.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Chlamydophila Infections/microbiology , Chlamydophila/growth & development , Doxycycline/therapeutic use , Pelvic Inflammatory Disease/microbiology , Adult , Antibodies, Bacterial/blood , Chlamydophila/genetics , Chlamydophila Infections/diet therapy , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Enzyme-Linked Immunosorbent Assay , Female , Humans , Polymerase Chain Reaction , Sequence Analysis, DNA
6.
Infect Immun ; 70(5): 2690-3, 2002 May.
Article in English | MEDLINE | ID: mdl-11953413

ABSTRACT

The BeWo trophoblast cell line does not constitutively express the tryptophan degrading enzyme indolamine 2,3-dioxygenase (IDO), nor can IDO expression be induced by gamma interferon. This correlates with the inability of BeWo cells to control the growth of Chlamydophila abortus, in contrast to effects observed in HeLa cells treated with gamma interferon.


Subject(s)
Abortion, Spontaneous/etiology , Chlamydophila/drug effects , Interferon-gamma/pharmacology , Trophoblasts/microbiology , Tryptophan Oxygenase/biosynthesis , Chlamydophila/growth & development , Chlamydophila/pathogenicity , Chlamydophila psittaci , Enzyme Induction/drug effects , Female , HeLa Cells , Humans , Indoleamine-Pyrrole 2,3,-Dioxygenase , Pregnancy , Tumor Cells, Cultured
7.
FEMS Microbiol Lett ; 190(1): 103-8, 2000 Sep 01.
Article in English | MEDLINE | ID: mdl-10981698

ABSTRACT

Strain-specific primer sequences derived from the helicase gene of an ovine abortifacient strain (S26/3) of Chlamydophila abortus (Chlamydia psittaci) were evaluated for the diagnosis of enzootic abortion in ewes (EAE) by polymerase chain reaction (PCR). C abortus DNA was amplified from tissues submitted from ovine abortion cases using genus-specific and strain-specific primers in a standard thermal cycler. Amplification was followed by Southern blotting and hybridisation with a strain-specific probe. Real-time PCR was also evaluated using strain-specific primers in a microvolume fluorimeter-based thermal cycler (LightCycler). Detection using both PCR methods was compared with other diagnostic methods against the standard of McCoy cell culture isolation. In this paper we report the application of strain-specific PCR as a fast, sensitive, specific method for the detection of EAE.


Subject(s)
Abortion, Veterinary/diagnosis , Antigens, Bacterial , Bacterial Outer Membrane Proteins , Chlamydophila Infections/diagnosis , Chlamydophila/isolation & purification , Polymerase Chain Reaction/methods , Sheep Diseases/diagnosis , Abortion, Veterinary/microbiology , Animals , Blotting, Southern , Cells, Cultured , Chlamydophila/genetics , Chlamydophila/growth & development , Chlamydophila Infections/microbiology , Chlamydophila Infections/veterinary , DNA Primers , Female , Fluorometry , Membrane Proteins/genetics , Pregnancy , Sensitivity and Specificity , Sheep , Sheep Diseases/microbiology , Species Specificity
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