Attachment of Treponema pallidum to fibronectin, laminin, collagen IV, and collagen I, and blockage of attachment by immune rabbit IgG.Fitzgerald, T J; Repesh, L A; Blanco, D R; Miller, J N
doi: 10.1136/sti.60.6.357pmid: 6394096
As shown by scanning electron and phase contrast microscopy, Treponema pallidum attached in vitro to basement membranes purified from kidney cortex tissues or from retinal vessels. This organism also attached to the extracellular matrix remaining after cultured cells had been solubilised with Triton X. Fibronectin, laminin, collagen, IV, collagen I, and hyaluronic acid are structural components of basement membranes and extracellular matrices. Experiments were performed to investigate the in vitro attachment of T pallidum to each of these components. Viable or heat inactivated treponemes were added to glass coverslips precoated with different concentrations of each component. After various times of incubation, coverslips were washed and the attached organisms were counted. Large numbers of viable organisms attached to each of these five components. In contrast, heat inactivation sharply reduced numbers of attached organisms. The IgG fractions of immune and non-immune rabbit serum samples were affinity purified using protein A. T pallidum was preincubated with both fractions, then incubated with either intact cultured cells or with coverslips coated with the five tissue components. The IgG from immune serum blocked treponemal attachment to the cultured cells and to fibronectin, laminin, collagen IV, and collagen I, but not to hyaluronic acid. These results are discussed in terms of attachment mechanisms of T pallidum and potential applications to in vivo infection.
Treponema pallidum specific IgM haemagglutination test for serodiagnosis of syphilis.Sato, T; Kubo, E; Yokota, M; Kayashima, T; Tomizawa, T
doi: 10.1136/sti.60.6.364pmid: 6394097
The Treponema pallidum specific IgM haemagglutination (TP-IgM-HA) test uses erythrocytes sensitised with antiserum to human IgM to separate IgM from IgG in serum. Specific antitreponemal IgM captured in this way is detected by adding a second reagent comprising erythrocytes sensitised with T pallidum antigen. Eighty two serum samples from 82 patients with untreated syphilis, 521 samples from 73 patients with treated syphilis, and 1872 samples from people who did not have syphilis were examined by the 19S(IgM)-TPHA (T pallidum haemagglutination), IgM-FTA-ABS (fluorescent treponemal antibody absorbed), TP-IgM-ELISA (enzyme linked immunosorbent assay), and TP-IgM-HA tests for the presence of 19S(IgM) antibodies specific to treponemes. The sensitivity of the TP-IgM-HA test was 97.6% and the specificity was 99.7%. We also traced IgM specific to treponemes in untreated patients with primary syphilis by four different tests. The TP-IgM-HA test results clearly reflected the effect of the treatment.
Susceptibility to antimicrobials of Neisseria gonorrhoeae isolated in Singapore: implications on the need for more effective treatment regimens and control strategies.Sng, E H; Lim, A L; Yeo, K L
doi: 10.1136/sti.60.6.374pmid: 6240311
The antimicrobial susceptibility of gonococci isolated in Singapore has been studied over several years. In 1983, the prevalence of penicillinase producing Neisseria gonorrhoeae (PPNG) was 33.5% and 64% of non-PPNG isolates had minimum inhibitory concentrations (MICs) of penicillin of greater than or equal to 0.5 mg/l. After a control programme, the isolation of the gonococcus from prostitutes was reduced and there was improvement in its susceptibility to antimicrobials. The incidence of PPNG strains was stabilised with a change in the treatment regimen. An influx of foreign prostitutes, however, had an unfavourable impact on these variables. Countries in South East Asia have a high prevalence of PPNG and non-PPNG strains that have reduced susceptibility to antimicrobials. In view of increased air travel the problem should be seen from a global perspective. Better treatment regimens and control strategies are urgently needed.
Comparison between bacampicillin and amoxycillin in treating genital and extragenital infection with Neisseria gonorrhoeae and pharyngeal infection with Neisseria meningitidis.Edwards, L D; Gartner, T
doi: 10.1136/sti.60.6.380pmid: 6440658
Sixty three patients presumed to have genital gonorrhoea who gave histories of extragenital sexual practices were randomly treated with amoxycillin 3 g or bacampicillin 4.8 g (equivalent to 3.5 g ampicillin) with probenecid 1 g to compare the efficacy of the drugs in treating gonorrhoea at all sites. Three patients were initially culture negative, and seven failed to return for follow up. Twenty seven of 28 patients receiving bacampicillin and all 25 receiving amoxycillin gave negative genital cultures for Neisseria gonorrhoeae five to nine days after treatment. Twenty two of 60 patients had extragenital gonorrhoea. One failed to return, but all eight who had received amoxycillin and 12 of 13 who had received bacampicillin gave negative pharyngeal and anorectal cultures after treatment. N meningitidis was isolated from the pharynx in 17 of 60 patients on initial attendance. Three of 14 were still colonised with the meningococcus after treatment. Two of 32 patients receiving amoxycillin and 12 of 31 receiving bacampicillin reported experiencing gastrointestinal side effects.
Erythromycin stearate in treating chlamydial infection of the cervix.Hunter, J M; Sommerville, R G
doi: 10.1136/sti.60.6.387pmid: 6518350
A total of 157 women attending departments of genitourinary medicine were treated for chlamydial infection of the cervix with erythromycin stearate 500 mg twice a day. Chlamydiae were eradicated from the cervix in 64/80 women treated for seven days and in 51/77 women treated for 14 days. In 12 of those treated for seven days and 15 of those treated for 14 days, reinfection was the probable cause of reisolation after treatment. The possibility of latent infection with Chlamydia trachomatis could not be excluded in five women, but was not more likely to occur with the shorter treatment course. Erythromycin stearate 500 mg twice daily for seven days appears to be an effective regimen for the treatment of uncomplicated chlamydial infection of the cervix.