Antigens of the sheep scab mite Psoroptes ovis.

Sheep scab caused by the mite Psoroptes ovis (Hering) is a highly contagious disease of sheep. As a first step in developing a mite-derived vaccine for controlling the disease, the soluble antigens in mite extracts which induce an immune response in sheep were identified by electrophoretic and immunoblotting techniques. At least 22 proteins were present in P. ovis extracts as revealed by Coomassie Blue staining. Mite-infested sheep serum recognised six antigenic bands in the extracts with approximate relative molecular weights ranging from 12 to 183 kDa. A deeply staining band at 31.2 kDa and another at 41.8 kDa are of particular diagnostic value. Immunoblotting studies showed that there was no cross reactivity between P. ovis and two other ectoparasites of sheep in the UK, the sheep louse Bovicola ovis (Schrank) and the sheep tick Ixodes ricinus L.

Antibodies to Chlamydia species in patients attending a genitourinary clinic and the impact of antibodies to C. pneumoniae and C. psittaci on the sensitivity and the specificity of C. trachomatis serology tests.

In a retrospective study, the prevalence of antibodies to Chlamydia trachomatis serovars D to K, C. pneumoniae, and C. psittaci in cases attending a genitourinary clinic was examined. Blood samples were collected from 7,002 cases attending the clinic in Doncaster, England between May 1983 and May 1990. Sera from these samples were tested by a modified microimmunofluorescence test using panels of microdots of egg-grown, purified elementary bodies representing a pool of C. trachomatis D to K, a single C. pneumoniae agent, a single C. psittaci agent, and a negative control. Serum specimens were tested for the presence of IgG and IgM at starting dilutions of 1/16 and 1/8, respectively. Chlamydial IgG at a level of 1/16 or higher and IgM at a level of 1/8 or higher was present in 66.6% and 2.6% of samples, respectively. Species-specific or cross-reactive IgG against C. trachomatis D to K, C. pneumoniae, and C. psittaci was present in 32.6%, 25.1%, and 0.1% of the samples, respectively. In 8.7% of samples, the level of IgG was similar against two or all three species (group-specific). IgM against C. trachomatis D to K, C. pneumoniae, or C. psittaci was present in 2.5%, 0.03%, and 0.04% of the samples, respectively. The results of the study show that antibodies to C. pneumoniae and C. psittaci account for up to half of all chlamydia IgG positive cases attending genitourinary clinics.(ABSTRACT TRUNCATED AT 250 WORDS)

Causes of conjunctivitis and keratoconjunctivitis in Karachi, Pakistan.

The causes of conjunctivitis and keratoconjunctivitis in 388 patients who attended eye casualty departments in Karachi, Pakistan, during a 5 month period were investigated. Most of these infections were diagnosed as adenovirus (291, 75%) or bacterial (71, 18.3%). Of the remainder, 9 cases (2.3%) were caused by herpes simplex virus and 7 (1.8%) by Chalmydia trachomatis. There was no evidence of typical active trachoma in this urban population. Bacteria or Candida albicans were also grown from 44 of the adenovirus cases (15%). Many of the bacteria grown from eyes in this study were resistant to antibiotics, probably because of inadequate and/or inappropriate self-medication with antibiotics in this community.

Experimental conjunctival infection of lambs with a strain of Chlamydia psittaci isolated from the eyes of a sheep naturally affected with keratoconjunctivitis.

Five ram-lambs were inoculated into the left conjunctival sac with the 15R isolate of Chlamydia psittaci, recovered from a sheep with keratoconjunctivitis. A sixth ram-lamb was kept in contact with them. The five lambs developed varying degrees of acute conjunctivitis and 14 days later C psittaci could be recovered from the inoculated eyes, from which Branhamella ovis was also isolated. The eyes were examined regularly for four months; C psittaci could not be re-isolated but the eyes developed varying degrees of follicular conjunctivitis. After four months the sheep were treated with corticosteroids in an attempt to reactivate a latent chlamydial infection but no chlamydiae could be isolated. Five months after the start of the experiment the six lambs were inoculated with 15R into the left conjunctival sacs. Acute conjunctivitis developed which was not as severe as after the first inoculation, but C psittaci could only be recovered from the left eyes of three sheep three days after inoculation. The eyes remained chronically affected by follicular conjunctivitis. Six months after the start of the experiment the left eyes were again inoculated with 15R; on this occasion acute conjunctivitis did not develop and chlamydiae could not be isolated. Chronic follicular conjunctivitis persisted until the experiment was terminated three months later.

Clinical and immunological responses of ewes following vaccination with an experimental formalin-inactivated Chlamydia psittaci (ovis) vaccine and subsequent challenge with the live organism during pregnancy.

The protection afforded by an experimental, killed, adjuvanted vaccine derived from the A22 strain of Chlamydia psittaci (ovis) against ovine enzootic abortion was studied. The vaccine was used undiluted (group A), at a dilution of 10(-3) (group B) and at a dilution of 10(-6) (group C). A fourth control group (group D) was inoculated with all components of the vaccine except the chlamydial antigen. A group of rams (group R) was also vaccinated with the chlamydial antigen diluted to 10(-3). Animals were challenged 70 days after mating with the A22 strain of C. psittaci (ovis) and were studied throughout pregnancy and the subsequent lambing period. Their cell-mediated immune responses were examined using a skin test and their humoral immune responses were studied using an ELISA. Tests for excretion of chlamydiae in their faeces and genital tract during pregnancy and after parturition and in the faeces of their lambs were made. The reproductive performance of the ewes was assessed by calculating the average weight of lambs produced per ewe in each group. The experimental vaccine protected the ewes in groups A and B against challenge with C. psittaci (ovis) as none showed clinical signs of OEA or excreted chlamydiae. The average weight of lambs produced per ewe in both groups was greater than 4 kg. Both groups seroconverted after vaccination but not all of them were positive to the skin test. The experimental vaccine at 10(-6) dilution of antigen did not protect the ewes as three of 10 ewes displayed clinical OEA and excreted chlamydiae in the products of parturition.(ABSTRACT TRUNCATED AT 250 WORDS)

Protection of ewes vaccinated with A22 strain Chlamydia psittaci (ovis) against challenge in pregnancy with homologous and heterologous strains of the organism.

Fifty ewes were randomly divided into four groups. Groups A and B were vaccinated with an experimental vaccine derived from the A22 isolate of Chlamydia psittaci (ovis), an isolate known to cause ovine enzootic abortion (OEA). Groups C and D were unvaccinated controls. In mid-pregnancy, animals in group A and C were challenged with live A22 C. psittaci (ovis) and those in B and D were challenged with a field isolate of the organism (BS) against which the commercially available A22 vaccine appeared to offer poor protection. In group A, three animals showed clinical signs of OEA and six excreted chlamydiae. In group B, five ewes showed clinical signs of OEA and excreted chlamydiae. In group C, three ewes had clinical signs of OEA but seven excreted chlamydiae. In group D, all 11 ewes showed clinical signs of OEA and excreted chlamydiae in the products of parturition. This group produced only four live lambs with an average weight of viable lamb per ewe of 1.4 kg, whereas the other groups each produced 12 or 13 lambs with an average weight of viable lamb per ewe of more than 4 kg. The BS isolate was much more virulent than the A22 isolate for unvaccinated, pregnant ewes. However, the A22 vaccine offered significant protection against the heterologous BS isolate although on this occasion it did not appear to alter the course of disease produced by the less pathogenic A22 isolate.

Management and prevention of ocular viral and chlamydial infections.

A majority of cases of preventable and/or curable ocular morbidity and blindness are caused by ocular infections. They may account for 70 to 90% of all ocular morbidity seen by family doctors, general practitioners, health centers, and local ophthalmologists in both developed and developing countries. Unfortunately, most health authorities and doctors, including ophthalmologists, consider these diseases to be of little or no importance because they are not fully aware of the high prevalence of these infections and the blinding sequelae which may occur following incorrect diagnosis and treatment. Also, they are not aware of the social and economic impact of these infections in the absence of proper management and implementation of preventive measures. In this review, we examine present knowledge of chlamydial and common viral ocular infections. We discuss the problems of diagnosis, management, and prevention and propose solutions relevant to developed and developing countries.

Colposcopy, biopsy, and cytology results in women with chlamydial cervicitis.

Colposcopy and biopsy were carried out at diagnosis and at follow up of 222 women. Of 322 cervical biopsy specimens taken, 174 were from women with chlamydial cervicitis (patients) and 48 from control women (both at diagnosis) and 100 from 76 patients and seven controls at follow up. Of the 174 patients with chlamydial cervicitis, 158 (91%) had erythema compared with 9/48 (19%) controls, and 140 (81%) had "follicles" and lumps compared with three (6%) controls. The cervical polymorphonuclear leucocyte (PMNL) count in a high power (x 1000) field (HPF) was 85 in patients compared with 47/HPF in controls. Cervical ectopia was found in 154 (89%) patients compared with 32 (67%) controls. After treating the 174 patients, we found erythema in nine (5%) and "follicles" in 16 (9%); both conditions were disappearing. Lymphocytic germinal follicles were found on histology in only 5/165 patients compared with none in controls or in patients at follow up examination (after treatment for chlamydial cervicitis). Inclusions were found in 6/165 patients compared with none in controls or patients at follow up. Chlamydiae were found on electron microscopy in slides from seven out of 159 patients compared with none from controls or 81 subjects at follow up. Estimating numbers of inflammatory cells and measuring vascularity showed diffuse increases in lymphocytes and plasma cells and increases in vascularity in both endocervical and exocervical tissue of patients with chlamydial cervicitis. These increases were lessened by treatment.

Dual infection of the conjunctiva with herpes simplex virus and Chlamydia trachomatis.

We describe a homosexual man with simultaneous infection of the conjunctiva by Herpes simplex virus and Chlamydia trachomatis. This dual infection was associated with a genital and disseminated Herpes simplex virus infection as well as asymptomatic chlamydial infection of the rectum and "nonspecific" urethritis. The findings in this case show the importance of laboratory investigation in cases of conjunctivitis associated with genital infection.

Sensitivity of mitomycin-C treated McCoy cells for isolation of Chlamydia trachomatis from genital specimens.

A new cell culture method was developed for the diagnostic isolation of Chlamydia trachomatis using McCoy cells pretreated with mitomycin-C. This drug acts on the cell by producing cross links between strands of DNA and results in the production of large, flat cells, which are similar to irradiated cells, and large chlamydial inclusions. In tests using a laboratory isolate of Chlamydia trachomatis, there were significantly more inclusions produced in mitomycin-treated monolayers than in cycloheximide-treated monolayers. Using clinical specimens, significantly more isolates were obtained in mitomycin-treated cells than in cycloheximide-treated cells. The new cell culture technique therefore offers a cell culture method which has the advantages of producing large inclusions similar to irradiated cells but with the convenience of drug treatment.

Diagnosis of ophthalmia neonatorum.

Ninety consecutively seen babies with eye discharge in the first three weeks of life were examined. Four babies had "sticky eyes" with no evidence of ophthalmia and had uniformly negative cultures and test results for antichlamydial antibody; these babies were excluded. Of the 86 babies with ophthalmia neonatorum, Neisseria gonorrhoeae was isolated from eight, Chlamydia trachomatis from 44, other bacteria alone from 20, and 14 had negative cultures. Three babies with negative cultures had longstanding conjunctivitis and had been treated with chloramphenicol eye ointment; all had antichlamydial IgM antibodies, indicating that the conjunctivitis was chlamydial. Hence the total number of babies whose conjunctivitis was chlamydial was 47. The result of the Gram stained conjunctival smear correlated well with that of culture and final assessment by the microimmunofluorescence test, enabling an immediate presumptive diagnosis to be made of gonococcal, chlamydial, or bacterial conjunctivitis. Prompt and effective treatment of babies was started. Explanation to the mother and contact tracing were carried out when the confirmatory cultures and antibody tests were completed. The Gram stained conjunctival smear is a highly sensitive, specific, and predictive test for the aetiological agent of ophthalmia neonatorum. By virtue of its simplicity and rapidity the test may be useful in developing countries.

Value and cost effectiveness of double culture tests for diagnosis of ocular viral and chlamydial infections.

Swabbings from the eyes of 4132 patients attending ophthalmic casualty and outpatients clinics were tested for chlamydiae, adenovirus, and herpes simplex virus. Laboratory isolation tests gave positive results for one of these three agents in 696 (16.8%) cases. When a positive isolation was obtained, only 341 (49%) agreed with the clinical diagnosis while 355 (51%) either had no definite diagnosis marked on the request card or had been clinically diagnosed incorrectly. Routine testing of ocular specimens for all likely organisms can enable the correct treatment to be started sooner than doing one test at each visit, thereby reducing the number of times the patient has to visit the clinic and the expenses involved.

Chlamydial pelvic infection in cats: a model for the study of human pelvic inflammatory disease.

The inoculation of feline keratoconjunctivitis agent (Chlamydia psittaci) directly into the oviducts of eight cats produced an acute disease that was characterised by hyperaemia of the tissue and pronounced polymorphonuclear leucocyte infiltration of the epithelium and subepithelial stroma. The lumens of the tubes contained exudates of desquamated epithelial cells and polymorphonuclear leucocytes. After about 30 days the disease subsided leaving chronic inflammation with the tissue infiltrated with both polymorphonuclear and mononuclear cells. Fimbrial scarring and formation of adhesions were apparent by 40 to 50 days after inoculation. Chlamydiae were isolated in McCoy cell cultures from most cats, in one for as long as 51 days after inoculation. Inclusions were seen in histological sections or smears of cells from the fimbriae of four of the eight cats. Six of the eight cats developed antibodies to feline keratoconjunctivitis agent, which were detectable as early as 12 days after inoculation. To facilitate repeated examinations of the cats' fallopian tubes, techniques for laparoscopy in cats and for the collection of specimens while under laparoscopic examination were developed. The latter technique has since been applied successfully in man.

Evidence of chlamydial infection in infertile women with and without fallopian tube obstruction.

This study investigates the prevalence of Chlamydia trachomatis antibodies in 164 infertile women who underwent diagnostic laparoscopy and dye insufflation as part of routine infertility investigations. C. trachomatis antibodies were found in 36 (22%) of 164 infertile women, which was significantly more than the prevalence of antibodies in a control group (22 of 200, 11%). C. trachomatis antibodies were found in 25 (35.7%) of 70 infertile women who had laparoscopically verified peripheral tubal disease. This was significantly more than the prevalence of C. trachomatis antibodies in infertile women with normal fallopian tubes (6 of 52, 11.5%). The prevalence of C. trachomatis antibodies in infertile patients with laparoscopically verified cornual disease was similar to those without cornual disease. C. trachomatis was not isolated from any of the patients studied. This study confirms that past chlamydial salpingitis is associated with the development of peripheral fallopian tube obstruction with resultant infertility.