Trachoma-inclusion Conjunctivitis Agents Research Articles

Chlamydial infection in women with cervical dysplasia

The prevalence of antibodies to chlamydiae, particularly to TRIC (trachoma-inclusion conjunctivitis) agents, was studied in women with cervical dysplasia and in women attending selected clinics (obstetrics, cancer-screening, and gynecology). In addition, attempts were made to isolate TRIC agents and herpesviruses from the cervices of these women. TRIC agent recovery rates were 4.1 per cent for women with dysplasia, 5.4 per cent for pregnant women, 7.8 per cent in the women's clinic, and 0.8 per cent in the cancer-screening clinic. Herpesvirus recovery rates were lower, on the order of 1 per cent or less in each clinic. Complement-fixing antibodies to chlamydial group antigen were detected in 21.5 per cent of women with dysplasia. With a more sensitive fluorescent antibody method, 77.6 per cent of the women with dysplasia or cervical cancer were shown to have antibodies to chlamydiae. In general, antichlamydial antibodies were less prevalent in the other clinic populations. The results of this study indicate that women with cervical dysplasia or cancer may have a high prevalence of antibodies to sexually transmitted agents other than herpesvirus type 2.

Some properties of the polysaccharide from cell cultures infected with TRIC agent (Chlamydia trachomatis).

The polysaccharide, elaborated in trachoma-inclusion conjunctivitis (TRIC) agent inclusions, was isolated from baby hamster kidney (BHK) cells grown and infected in suspension cultures. It was characterized by physical, chemical and enzymic methods as a glycogen with an average chain length of 14 to 16 glucose units.

Dissemination and immunogenicity of live TRIC agent in baboons after parenteral injection. II. Experiments with a 'slow-killing' strain.

SUMMARYAfter a single subcutaneous injection into baboons the MRC-4 strain of trachoma/inclusion conjunctivitis (TRIC) agent underwent limited multiplication at the injection site, but was then eliminated rapidly from the skin and regional lymph nodes. Forty-eight hours after a single intravenous injection, but not thereafter, it appeared in the peripheral lymph nodes and spleen. The single parenteral injections failed to immunize baboons against conjunctival challenge with the homologous strain. These findings contrasted with those previously reported for the more virulent mutant, MRC-4 f, which multiplied readily in the skin, lymph nodes and spleen, persisted in these tissues up to 3 weeks after injection, and conferred good immunity to conjunctival challenge with MRC-4. The difference in behaviour of MRC-4 and MRC-4 f might be accounted for, at least in part, by the use of a smaller inoculum of live MRC-4; but similar findings in guinea-pigs, reported elsewhere, suggest that the differences observed are real. In conjunction with previous work, the present study suggests that the immunogenicity of TRIC agent is closely related to the mass of antigen that can be administered to or propagated within the recipient.We are grateful to Mr D. Venters for his able technical assistance.

INVESTIGATION OF NEONATAL CONJUNCTIVITIS IN THE GAMBIA

Of 297 babies born in the general hospital in Bathurst, Gambia, 101 contracted conjunctivitis within 2 weeks of birth. The bacteria most often isolated from their eyes were staphylococci. 4 infants had gonococcal ophthalmia, which responded rapidly to antibiotics. 4 others were infected with trachoma/inclusion-conjunctivitis (TRIC) agent. In them, the syndrome was characteristic of trachoma rather than inclusion conjunctivitis, but spontaneous resolution without damaging sequels was complete within six months. TRIC agent was not demonstrated in the genital tracts of the mothers. One of them had cervicitis; her husband had a urethral infection, from which TRIC agent was isolated. It is likely that these 4 infants acquired their trachoma at birth from the maternal genital tract.

Immunogenicity of experimental trachoma vaccines in baboons: III. Experiments with inactivated vaccines

Heating at 37° C. for 5 days completely abolished the capacity of a trachoma/inclusion conjunctivitis (TRIC) vaccine to protect baboons against conjunctival infection. Treatment with formalin also impaired or abolished immunogenicity.The rate of inactivation of TRIC agent by ultraviolet light was exponential, and was about 7 times faster than that of a suspension of vaccinia virus of comparable turbidity. By contrast with vaccinia, irradiation of TRIC agent with twice the dose of ultraviolet light needed to destroy infectivity resulted in loss of immunogenicity.The deleterious action of these inactivation procedures on the potency of TRIC vaccines may be explained in terms of damage to a protective antigen; alternatively, live vaccines may be more immunogenic because TRIC agents are capable of multiplying within primate hosts after parenteral injection.Unlike the same type of variant of another strain of inclusion conjunctivitis, the ‘fast-killing’ variant of MRC-4 was still pathogenic for the baboon conjunctiva.

Immunogenicity of experimental trachoma vaccines in baboons. II. Experiments with adjuvants, and tests of cross-protection.

A mineral oil adjuvant failed to enhance or to prolong the somewhat shortlived immunity induced in baboons by trachoma/inclusion conjunctivitis (TRIC) vaccines, and was of little or no value in increasing or prolonging the formation of group complement-fixing (CF) antibody. Vaccines prepared with protamine sulphate or with calcium phosphate were no more immunogenic than the untreated parent suspensions.Cross tests with aqueous vaccines revealed antigenic differences in the TRIC agents examined, in terms of their ability to protect against conjunctival challenge. Strain MRC–1/OT differed from MRC–17 and from MRC–4, and MRC–187 from MRC–4f.The four Gambian trachoma agents tested were much less effective than the MRC–4 strain of inclusion conjunctivitis in inducing group CF antibody in baboons. The titre of circulating antibody bore no relation to the state of immunity to conjunctival challenge.In three baboons given mineral oil adjuvant vaccine and in one given aqueous vaccine the conjunctival responses to subsequent challenge were significantly enhanced. This reaction may be an expression of a hypersensitive state induced by relatively ineffective vaccines; like immunity, it is unrelated to the titre of CF antibody in the serum.

SEROLOGICAL STUDIES ON GROUP- AND SPECIES-SPECIFIC ANTIGENS OF TRACHOMA AND INCLUSION CONJUNCTIVITIS (TRIC) AGENTS.

Group-reactive ether soluble psittacosis and boiled mouse pneumonitis antigens were tested in parallel, with 85 serum specimens. The results indicate that the group-specific C.F. antigens of these organisms are indistinguishable when tested against sera of trachoma patients, monkeys infected with trachoma or against sera of other individuals.Sera of rabbits immunized with viable trachoma-inclusion conjunctivitis (TRIC) organisms, grown in tissue culture, were absorbed with boiled elementary body suspension of mouse pneumonitis agent, which removed the group reactive antibodies, and resulted in a species-specific anti-TRIC serum.The absorbed and unabsorbed TRIC sera were titrated against purified E.B. suspensions, which were prepared both from yolk and from tissue culture grown organisms, of homologous TRIC strains and from other heterologous Bedsonia organisms.Results of absorption experiments indicate that group reactive antigens prepared from mouse pneumonitis and psittacosis are indistinguishable by C.F. test from the group-specific component of the TRIC antigens. The species-specific antigen of the TRIC agents was well distinguished from the species-specific antigen of the psittacosis agent. However, the C.F. test did not distinguish the strains isolated from trachoma from those isolated from cases of inclusion conjunctivitis.The stabilizing effect of sucrose and albumin upon the species-specific C.F. antigen of purified elementary bodies of TRIC organisms was found to be pronounced.Our attempts to produce a species-specific antigen preparation, free from group component, failed.We have pleasure in thanking Dr F. B. Gordon for suggestions; Dr B. V. Birtašević, Mr H. R. Dressler, Dr E. S. Murray and Dr A. J. Vargosko for procuring sera of patients or organisms grown in tissue culture; Dr T. A. Strike for the help with statistical computations; HMC P. R. Hill, HM3 C.O. Wiese and Mr B. L. Ward for invaluable technical assistance.