Chlamydia trachomatis, Elementary Bodies

Chlamydiaceae exists in two morphologically distinct forms, the small (9300-400nm) infectious Elementary Body (EB) and the larger (800-1000nm) noninfectious Reticulate Body (RB). EB is very resistant to harsh environmental factors. Chlamydiaceae does not replicate in the EB form. EBs bind to receptors on host cells and stimulate uptake by the infected cell. The RB is the metabolically active, replicating chlamydial form. This form is osmotically fragile. They are protected by their intracellular location.\n\nChlamydiaceae have the following properties of bacteria: Possess inner and outer membranes similar to those of gram negative bacteria; Contains both DNA and RNA (genome size of approximately 500-1000kB); Possess prokaryotic ribosomes; Synthesizes their own proteins, nucleic acids and lipids; Are susceptible to numerous antibacterial antibiotics. Unlike bacteria, Chlamydiaceae lack a peptidoglycan layer. The outer membrane is extensively cross-linked by disulfide bonds between cystein residues.\n\nOther structural components of Chlamydiaceae are a genus-specific lipopolysaccharide (LPS) that can be detected in a complement fixation test and species- and strain-specific outer membrane proteins.\n\nColonization of Chlamydia begins with attachment to sialic acid receptors on the eye, throat or genitalia. It persists at body sites that are inaccessible to phagocytes, T-cells, and B-cells. The growth cycle is initiated when the infectious EBs attach to the microvilli of susceptible cells. Followed by active penetration into the host cells. After internalization, the bacteria remain within cytoplasmic phagosomes, where the replicatve cycle proceeds. The fusion of the cellular lysosomes with the EB-containing phagosome and subsequent intracellular killing is inhibited. Phagolysosomal fusion is prevented if the outer membrane is intact. If the outer membrane is damaged or the bacteria are inactivated by heat or coated with antibodies, phagolysosomal fusion occurs with subsequent bacteral killing.\n\nWithin 6-8 hours after entering the host cell, the EBs reorganize into the metabolically active RBs. RBs are able to synthesize their own DNA, RNA and proteins. They lack the necessary metabolic pathways to produce their own high energy phospahte compounds. Chlamydiaceae have been termed energy parasite. Some strains depend upon the host to provide specific amino acids. RBs replicate by binary fussion, which continues for the next 18-24 hours. Approximately 18-24 hours after infection, the RBs begin reorganizing into the smaller EBs. Between 48-72 hours, the host cell ruptures, releasing the infective EBs.\n\nChlamydiaceae exists as 15 different serotypes. These serotypes cause four major diseases in humans: endemic trachoma (caused by serotypes A and C), sexually transmitted disease and inclusion conjunctivitis (caused by serotypes D and K), and lymphogranuloma venereum (caused by serotypes L1, L2, and L3). Studies reveal that Chlamydia, because of its cell wall, is able to inhibit phagolysosome fusion in phagocytes. The cell wall is proposed to be gram-negative in that it contains an outer lipopolysaccharide membrane, but it lacks peptidoglycan in its cell wall. This lack of peptidoglycan is shown by the inability to detect muramic acid and antibodies directed against it. It may, however, contain a carboxylated sugar other than muramic acid. The proposed structure consists of a major outer membrane protein cross-linked with disulfide bonds. It also contain cysteine-rich proteins (CRP) that may be the functional equivalent to peptidoglycan. This unique structure allows for intracellular division and extracellular survival.\n\nApplications:\nSuitable for use in Indirect Immunofluorescence, Conjugation. May be used in place of neat antiserum in most antibody-based technique. Other applications not tested.\n\nRecommended Dilution:\nIndirect Immunofluorescence: 1:1000-1:3000 (Against all serovars (A-K, L1-L3).\nOptimal dilutions to be determined by researcher.\n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. For long-term storage and to avoid repeated freezing and thawing, add sterile glycerol (40-50%), aliquot and store at -20 degrees C. Aliquots are stable for at least 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

C4250-06

Size

1ml

Applications

IF

Hosts

Rabbit

Form

Supplied as a liquid in PBS, pH 7.2, 0.1% sodium azide. No stabilizing proteins added.

P Type

Pab

Purity

>95% pure. Purified by Protein A chromatography.

Isotype

IgG

Additional Info

Recognizes purified, disrupted EBs of Chlamydia trachomatis. Crossreacts with Chlamydia psittacii & Chlamydia pneumoniae (TWAR). Negative vs. HEp-2 cells and egg yolk sac.