Disease relevance of Trachoma

• The new azalide antibiotic azithromycin is effective as a single oral dose in the chemotherapy of genital Chlamydia trachomatis infections, and we have assessed its efficacy for trachoma treatment [1].
• A common antigenic determinant on the chlamydial major outer membrane protein was detected on each of the three Chlamydia trachomatis biovars (trachoma, lymphogranuloma venereum, and mouse) [2].
• We evaluated the validity of clinically determined active trachoma as a surrogate for chlamydial eye infection in 1059 children from the Egyptian arm of the Azithromycin in the Control of Trachoma study [3].
• Chlamydia trachomatis is a strict human pathogen producing infections that cause medically important chronic inflammatory diseases, such as blinding trachoma and tubal factor infertility [4].
• Impact of community-based azithromycin treatment of trachoma on carriage and resistance of Streptococcus pneumoniae [5].

High impact information on Trachoma

• The chlamydial major outer membrane protein (MOMP) is thought to play an important role in the development of protective immunity against chlamydial infection, and is therefore considered to be a promising candidate antigen in the development of a trachoma vaccine [6].
• Thus, the Th cell epitopes contained within these peptides, in combination with different trachoma serovar-specific B cell neutralizing determinants, may be useful in the development of a synthetic or recombinant trivalent trachoma vaccine [6].
• Both vitamin A deficiency and trachoma are important causes of preventable ocular diseases [7].
• We assessed the potential of community-wide azithromycin treatment for trachoma control [8].
• Programmes to prevent blindness due to trachoma are based on community-wide treatment with topical tetracycline [8].

Chemical compound and disease context of Trachoma

• The currently recommended treatment of active trachoma with repeated doses of tetracycline eye ointment has many disadvantages [1].
• We carried out a randomised single-blind comparison of azithromycin (a single oral dose of 20 mg/kg) with conventional treatment (6 weeks of topical tetracycline plus erythromycin for severe cases) in two villages with endemic trachoma in The Gambia [1].
• Deltamethrin spray is effective for fly control and may be useful for reducing trachoma and diarrhoea in some situations, but further research on sustainable fly-control methods is needed [9].
• We demonstrated that the trachoma and LGV biovars compete for the same receptor(s) on host cells and that their infectivity was inhibited by heparin or heparan sulphate [10].
• In contrast, MAb L2-15k, which recognized an epitope located on the 15-kDa protein of the LGV-434 strain, reacted with the 15- and 14-kDa, cysteine-rich proteins of both LGV and trachoma biovar strains, but did not react with related proteins of two Chlamydia psittaci strains [11].

Biological context of Trachoma

• Although the host immune response to the 60-kDa chlamydial heat shock protein (hsp60) has been implicated in trachoma pathogenesis, no studies have examined mucosal immune responses to hsp60 in populations for which chlamydia is endemic [12].
• Pharmacokinetics of azithromycin in trachoma patients: serum and tear levels [13].
• Significantly, attachment could be fully restored for heparitinase-treated organisms of both biovars with exogenous heparan sulfate; however, the coating of the trachoma biovar organisms with heparan sulfate rendered the trachoma biovar similar to the phenotype of the LGV biovar by > 90% sensitivity to heparin inhibition of attachment [14].
• Visual acuity, cause of vision loss, trachoma, and vitamin A deficiency were included in the clinical examination [15].
• Epidemiology of trachoma in the West Bank and Gaza Strip [16].

Anatomical context of Trachoma

• Chlamydiae from mouse fibroblasts (McCoy cells) persistently infected with a trachoma strain (G17) of Chlamydia trachomatis repeatedly established new persistent infections in wild McCoy cells more rapidly than did wild chlamydiae [17].
• Antibody-secreting cells (ASCs) specific to chlamydial major outer membrane protein (MOMP), heat shock protein 60, and whole elementary bodies were detected in children with no evidence of ocular disease, and the immunoglobulin (IgA) response was significantly increased in those with follicular trachoma [18].
• Expression of MHC class II antigens by conjunctival epithelial cells in trachoma: implications concerning the pathogenesis of blinding disease [19].
• Zymography revealed that gelatinase B levels in trachoma specimens were significantly higher than the levels found in normal conjunctiva (1739.6 (1078.3) v 609.3 (395.9) scanning units; p = 0.0127) [20].
• Activated macrophages with giant cell morphology clearly stained with the gelatinase B specific monoclonal antibody were observed in trachoma specimens [20].

Gene context of Trachoma

• In addition, quantitative zymography was used to compare the activity of gelatinase B in conjunctival biopsy specimens from seven patients with active trachoma and seven control subjects [20].
• Relationship between Tear TNF-alpha, TGF-beta1, and EGF levels and severity of conjunctival cicatrization in patients with inactive trachoma [21].
• One cluster included all Chlamydia trachomatis ompA alleles (trachoma group) [22].
• Cytoplasmic IL-1 alpha and IL-1 beta expression was noted in the conjunctival epithelium in all trachoma specimens [23].
• Tear tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta 1 (TGF-beta1), and epidermal growth factor (EGF) levels were determined in patients with inactive trachoma, and a possible relation between these cytokines and conjunctival cicatrization severity was investigated [21].

Analytical, diagnostic and therapeutic context of Trachoma

• Direct amplification of the major outer membrane protein (MOMP) gene by polymerase chain reaction (PCR) was used to identify Chlamydia trachomatis in eye swabs from clinically active cases of endemic trachoma in a Gambian village [24].
• When treatment was continued for 12 months, a marked decrease in the prevalence of trachoma and in the grades of intensity of inflammatory responses as well as the positivity rate for Chlamydia trachomatis was observed in the groups treated with the topical oxytetracycline or oral doxycycline compared with the control group [25].
• The prevalence of trachoma was equally low (7%) in all three groups following retreatment with tetracycline [26].

References