Prevalence of Chlamydia trachomatis in women attending a family planning clinic in Papua New Guinea.

OBJECTIVE: To determine the prevalence of Chlamydia trachomatis infection in women attending a family planning clinic in Papua New Guinea, in the period between April and June 1991. SETTING: The outpatient department of Obstetrics and Gynaecology of Port Moresby General Hospital, Port Moresby, Papua New Guinea, the departments of Dermato-Venereology and Clinical Microbiology of the Erasmus University, Rotterdam, The Netherlands and the National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands. PATIENTS: A total of 254 consecutive women who attended the family planning clinic at Port Moresby General Hospital, Papua New Guinea were enrolled into this study. METHODS: Cervical infections with C trachomatis were diagnosed using the direct immunofluorescent assay (DFA) and the polymerase chain reaction (PCR). Serum IgM and IgG antibodies directed against C trachomatis were detected using the enzyme-linked fluorescent assay (ELFA). RESULTS: The prevalence of C trachomatis was 14.6% using the PCR, 9.1% using the DFA and 17.3% when the results of the PCR and the DFA were combined. An elevated IgM titre was observed in 14.2% of the women, whereas 44.1% had an elevated IgG titre. The titres of IgM or IgG were significantly higher in women who were positive using the PCR or the DFA than in those who were negative in both the PCR and the DFA (p = 0.032 and p = 0.0046, respectively). CONCLUSION: Cervical infection by C trachomatis can be considered a major health problem in at least the studied population in Papua New Guinea. The prevalence of C trachomatis infection is at least comparable with that in groups with a high prevalence in industrialized countries. Effective screening and treatment programmes are imperative to combat this problem.

Chlamydia trachomatis-specific antibodies in patients with pelvic inflammatory disease: comparison with isolation in tissue culture or detection with polymerase chain reaction.

OBJECTIVE: The detection of acute phase antibodies against C trachomatis and its comparison with tissue culture or polymerase chain reaction (PCR) on samples of cervix and urethra obtained from patients with pelvic inflammatory disease (PID). METHODS: In the academic hospital Dijkzigt, Rotterdam, The Netherlands, prospective investigations were performed on 49 consecutive patients who were admitted with the diagnosis of PID. Infections with C trachomatis were traced using tissue culture, PCR or by determining acute phase IgG and IgM antibodies. Differences between the sensitivities of serology and tissue culture or PCR were calculated using the Fisher exact test. RESULTS: C trachomatis infection was detected more often in PID patients using serology in comparison with PCR (p < 0.05) or tissue culture (p < 0.05). All patients who were positive in tissue culture also had acute phase antibodies. CONCLUSION: The establishing of acute C trachomatis infections in PID patients on the basis of serology was superior to either tissue culture or PCR on samples obtained from cervix and urethra.

[Successful culture of Chlamydia pneumoniae in 2 asymptomatic patients]. / Succesvolle kweek van Chlamydia pneumoniae bij twee asymptomatische patiënten.

In two women, partners of 41 and 36 years old, positive cultures of Chlamydia pneumoniae were repeatedly obtained from the throat. Both individuals were asymptomatic during the period described. Eradication was not achieved despite treatment with doxycycline. C. pneumoniae on the basis of serological data is considered a common cause of respiratory tract infections. However, this micro-organism has only been isolated in the Netherlands once. Carrier status has been described in the literature, although its frequency is unknown.

The effects of medium and rate of freezing on the survival of chlamydias after lyophilization.

The effects of suspension media and rate of freezing on the survival of Chlamydia trachomatis LGV2 and Chlamydia pneumoniae after lyophilization were assessed. The highest loss in infectious elementary bodies (EBs) occurred during lyophilization. The survival was higher after freezing at a rate of 1 degree C min-1 and lyophilization than that after rapid freezing at -70 degrees C or -196 degrees C. The recovery (+/- 5%) was higher when fetal calf serum (FCS) containing glucose, saccharose or lactose were used as lyophilization media than that (0.5-3%) when yolk-sac, skimmed milk or phosphate buffer containing sucrose, glutamine and 10% FCS (SPG) were used. After lyophilization, the survival was not affected in the tested range from 10(4) to 5 x 10(6) inclusion-forming units (ifu) ml-1 prior to freezing. After storage for 4 months at 4 degrees C, the numbers of ifu of both Chlamydia serovars that were recovered were identical to the numbers of ifu immediately after lyophilization. It was concluded that chlamydias can be stored and transported in lyophilized form. However, a loss of 95% in infectious EBs should be taken into account.

Detection of IgG, IgM and IgA antibodies in patients with uncomplicated Chlamydia trachomatis infection: a comparison between enzyme linked immunofluorescent assay and isolation in cell culture.

The diagnostic value of serum IgG, IgM and IgA in patients with uncomplicated urogenital Chlamydia trachomatis infection was compared with isolation in cell culture. C. trachomatis specific antibodies were determined with an enzyme linked immunofluorescent assay using elementary bodies from C. trachomatis serotypes E,F,H,I,J and LGV2 as antigens. At least two sera from each patient were tested and cultures were also established on the same day. Excluding the IgM titres in men, significantly more IgG, IgA and IgM and combinations of these antibodies were observed in culture positive patients. The sensitivity with which IgG titres in men or IgG and/or IgM titres in men and women could be determined, was significantly lower using C. trachomatis LGV2 as the only antigen than when all 6 antigens were used. The presence of 10 or more leucocytes in the urine sediment of men correlated positively with an IgG or an IgG and/or IgM titre.

Factors influencing the infectivity of Chlamydia pneumoniae elementary bodies on HL cells.

The influence of variations in the pH, NaCl concentration, temperature, and concentrations of calcium and magnesium ions on the survival of Chlamydia pneumoniae elementary bodies (EBs) outside the host cells was investigated. The survival was determined after various incubation periods by counting the inclusion-forming units after C. pneumoniae was cultured for 72 h on monolayers of HL cells. The normal physiological conditions were restored prior to infecting the HL cells with C. pneumoniae. Declines in the infectivities of C. pneumoniae EBs were observed at pH values of lower than 5 and higher than 8 or at NaCl concentrations of less than 80 mM. The viability of C. pneumoniae EBs in SPG medium decreased as the temperature and/or incubation period increased. Incubation temperatures of up to 20 degrees C and incubation periods of up to 48 h did not affect the viability of C. pneumoniae. One hundred percent of the C. pneumoniae EBs were infective after 1 h of incubation at 35 degrees C, whereas 90, 50, and 40% survived after incubations of 8, 24, and 48 h, respectively. The viability of C. pneumoniae was unaffected within the investigated range of Ca2+ and Mg2+ ion concentrations in the medium. The presence of 10% fetal calf serum in the incubation medium had a stabilizing effect on the viability of C. pneumoniae. This effect became more pronounced as the incubation period increased.

Membrane properties of oxysterols. Interfacial orientation, influence on membrane permeability and redistribution between membranes.

The membrane properties of cholesterol auto-oxidation products, 7-ketocholesterol, 7 beta-hydroxycholesterol, 7 alpha-hydroxycholesterol and 25-hydroxycholesterol were examined. Monolayer studies show that these oxysterols are perpendicularly orientated at the interphase. Only 7 beta-hydroxycholesterol and 7 alpha-hydroxycholesterol are tilted at low surface pressures. In mixed monolayers with dioleoylphosphatidylcholine, 7-ketocholesterol, 7 beta-hydroxycholesterol and 7 alpha-hydroxycholesterol show a condensing effect in this order, although to a lesser extent that that observed for cholesterol. In liposomes these oxysterols also reduce glucose permeability and in the same order as their condensing effect. On the other hand 25-hydroxycholesterol shows no condensing effect in monomolecular layers whereas glucose permeability in liposomes is enormously increased. The permeability increase is already maximal at 2.5 mol% 25-hydroxycholesterol. Differential scanning calorimetry experiments reveal that all four oxysterols tested reduce the heat content of the gel----liquid-crystalline phase transition. It is concluded that 7-ketocholesterol, 7 beta-hydroxycholesterol and 7 alpha-hydroxycholesterol have a cholesterol like effect, although less efficient than cholesterol, whereas 25-hydroxycholesterol showing no condensing effect acts as a spacer molecule. Packing defects in the hydrophobic core of the bilayer due to the presence of the C-25 hydroxyl group are believed to cause the permeability increase. The transfer of radiolabelled (oxy)sterols from the monolayer to lipoproteins or vesicles in the subphase was studied. The transfer rate increases in the following order 7-ketocholesterol, 7 beta-hydroxycholesterol, 7 alpha-hydroxycholesterol, 25-hydroxycholesterol. The difference in rate between 7-ketocholesterol and 25-hydroxycholesterol is 20-fold. A higher rate of transfer is observed in the presence of high density lipoproteins and small unilamellar vesicles. A transfer rate for cholesterol is hardly measurable under these conditions. The transfer measured is consistent with the involvement of a water-soluble intermediate.