Comparison of two PCR-based assays for detecting Mycoplasma genitalium in clinical specimens.
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Biomedical subjects
Publications and source records attributed to D Taylor-Robinson.
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OBJECTIVE: To determine how often Chlamydia trachomatis cervical infections are detected in women following completion of a currently recommended treatment regimen and the reason for recurrence. METHODS: A longitudinal follow-up study of 43 initially C trachomatis-positive women for periods of up to two years. RESULTS: C trachomatis was detected in three women, 19, 16 and about four months, respectively after completion of treatment. All specimens from the other 40 women which were taken during visits two to seven, that is periods of three to 700 days after treatment, were chlamydia-negative. CONCLUSION: Although C trachomatis is usually eradicated from the genital tract by conventional treatment, occasionally it may be found again. It is difficult to determine whether detection after treatment is due to persistence or reinfection and further studies are required.
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Thirty young adult mice, of strain BALB/c, treated previously with progesterone, were inoculated intravaginally (10 mice) or directly into the uterus (10 mice) with Mycoplasma pulmonis and 10 mice remained uninoculated. Ten mice not treated with the hormone were also inoculated intrauterinely with M. pulmonis. The same numbers of mice treated with oestradiol were inoculated in the same ways with M. hominis. Vaginal swab specimens were obtained from all mice 7, 14 and 28 days after inoculation and samples of genital tract tissue were collected from pairs of mice at the same time intervals. Large numbers of M. pulmonis and M. hominis organisms were isolated from the vagina throughout the course of the experiments and they were cultured also from the cervix and uterine horns. Mycoplasma-like bodies were demonstrated by scanning electron microscopy in the cervix and in the uterus, but neither mycoplasmal species was found attached to vaginal epithelium. The results of silver-enhanced immunogold labelling in conjunction with scanning microscopy provided assurance that the mycoplasma-like bodies were, in fact, mycoplasmas. The importance of hormone treatment was indicated by the diminished susceptibility of untreated mice to M. pulmonis and the almost complete insusceptibility to M. hominis, shown by culture and scanning electron microscopy.
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OBJECTIVE: To find out whether women with bacterial vaginosis detected early in pregnancy are at increased risk of preterm delivery. DESIGN: Prospective description cohort study. SETTING: Antenatal clinic in a district general hospital. SUBJECTS: 783 women examined during their first antenatal clinic visit and screened for recognised risk factors for preterm delivery and the presence of bacterial vaginosis or intermediate abnormal flora detected by examination of a vaginal smear stained by Gram's method. MAIN OUTCOME MEASURES: Gestational age at delivery classified as late miscarriage (16-24 weeks' gestation), preterm delivery (24-37 weeks' gestation), term delivery (> or = 37 weeks' gestation). RESULTS: Multiple logistic analysis showed that there was an increased incidence of preterm delivery in women with a previous preterm delivery (9/24; odds ratio 25; 95% confidence interval 9 to 70; P < 0.001) and bacterial vaginosis (9/115; 2.8; 1.1 to 7.4; P = 0.04). A further logistic analysis of data from women recruited before 16 weeks' gestation showed that preterm deliveries or late miscarriages occurred more often in women with bacterial vaginosis (12/77; 5.5; 2.3 to 13.3; P < 0.001). CONCLUSIONS: Late miscarriage and preterm delivery are associated with the presence of bacterial vaginosis in early pregnancy. This is independent of recognised risk factors such as previous preterm delivery.
Enzyme immunoassays (EIAs) are widely used to diagnose chlamydial infections in patients attending genitourinary medicine clinics. They are relatively easy to perform and are suitable for testing large numbers of samples. The objective of this study was to determine what proportion of women with chlamydial infection, defined as the presence of Chlamydia trachomatis in a cervical smear or deposit and/or in the urinary tract, detected by means of a sensitive direct fluorescent antibody test could also be identified by using two commercially available EIAs to test cervical samples. On hundred fifty-one women attending the genitourinary medicine clinic at St. Mary's Hospital, London, were enrolled. The use of the Chlamydiazyme (Abbott Diagnostics, UK) and MicroTrak (Syva, UK) EIAs resulted in the identification of only 56% and 63%, respectively, of women with chlamydial infection detected by direct fluorescent antibody staining. Thus, the EIAs available for detection of chlamydiae in cervical samples are inadequate for identifying all infected women. Improvement might be achieved by testing multiple samples or by resorting to tests of greater sensitivity.
Mycoplasma genitalium was sought in synovial fluids from 13 patients, of whom five had Reiter's syndrome, four had rheumatoid arthritis, and one each had systemic lupus erythematosus, psoriatic arthritis, rheumatic fever and undefined arthritis. The mycoplasma was detected by a PCR assay in the knee joint of a 25-year-old man with Reiter's syndrome, from whom urethral ureaplasmas were isolated and whose synovial fluid mononuclear cells responded to ureaplasmal antigens in a proliferation assay. Mycoplasma genitalium was also detected in the knee joint during an exacerbation of arthritis in a 58-year-old man who had had seronegative juvenile polyarthritis that had evolved to seronegative rheumatoid arthritis.
We describe a patient in whom HIV-associated nephropathy developed in association with the detection of Mycoplasma fermentans. This mycoplasma was found in renal tissue by means of a polymerase chain reaction when nephropathy was first evident, and subsequently in urine, blood and the throat. The evidence presented strengthens the causal association of this micro-organism with HIV-induced nephropathy.
Little is known of the in vivo role of the immune system in controlling human papillomavirus infection in the genital tract. The authors have studied 125 closely monitored patients with genital warts. Of these 125 patients, wart regression was seen in 28 patients. This study provides evidence that clearance of human papillomavirus from the genital tract is characterized by an active cell-mediated immune response. Regressing warts (n = 14) contained significantly more T lymphocytes (P < .05, Wilcoxon rank sum test) and macrophages (P < .01) than did nonregressing controls (n = 14). CD4-positive lymphocytes predominated in regression, both within the wart stroma and the surface epithelium, where there was a significant change in the ratio of CD4+ to CD8+ cells (P < .01). Lymphocytes in regression also showed greater expression of activation markers, and the majority were of the "antigen-experienced" phenotype. There was no difference in Langerhans cell numbers, although there was significant induction of the immune accessory molecules HLA-DR and ICAM1 (P < .05) on keratinocytes, and E-selectin and VCAM1 (P < .05) on endothelial cells in regressing warts. The changes in regression are consistent with a delayed-type hypersensitivity reaction to foreign antigen, and the ability to induce and mount such a response may be a critical determinant of effective natural immunity to the genital HPVs. Specific targeting of delayed-type hypersensitivity responsiveness may increase the efficacy of strategies for immuno-intervention against HPV infection in the genital tract.
Resistance against vaginal colonisation by Mycoplasma pulmonis in strain TO mice after exposure to the mycoplasma was investigated. Eighteen mice from which M. pulmonis had been eliminated from the vagina, either naturally or by antibiotic therapy, were resistant to vaginal recolonisation. Specific antibody was measured by an indirect microimmunofluorescence technique and the geometric mean titre (GMT) for each group of mice is presented. Almost all of 31 mice that had developed circulating antibody (GMT 83) or local antibody (GMT 40), or both, after vaginal exposure were resistant to re-colonisation, as were those in which antibodies could not be detected. Seven other mice which had been colonised only in the oropharynx previously and which possessed antibody--circulating (GMT 64) or local (GMT 30), or both--were resistant to vaginal colonisation, but 13 mice with little or no antibody after lack of colonisation at either anatomical site were susceptible. All of 15 mice given killed M. pulmonis organisms intravenously, despite developing circulating antibody in high titre (GMT 122), were susceptible to vaginal colonisation, as were 14 of 15 mice that developed circulating (GMT 15) and local antibodies after being given killed organisms intravaginally. However, 25 mice with high titres of circulating (GMT 154-170) or local (GMT 20) antibody, or both, after receiving live organisms intravenously, were less susceptible to vaginal colonisation (17 becoming colonised) than were 21 non-immunised mice (all becoming colonised) and the organisms were eradicated more rapidly from the former. Despite this, the mice that were colonised following intravenous inoculation of live organisms had pre-challenge antibody titres that were as great as those that were not colonised.(ABSTRACT TRUNCATED AT 250 WORDS)
OBJECTIVE: To determine the longitudinal changes in the incidence of vaginosis in pregnancy. DESIGN: A prospective study of women during pregnancy. SETTING: A District General Hospital in North-West London. SUBJECTS: Seven hundred and eighteen pregnant women attending antenatal clinics. At their first attendance and subsequently, Gram-stained vaginal smears were examined and Mycoplasma hominis and Gardnerella vaginalis were sought by culture. RESULTS: Initially, 87 (12%) women had bacterial vaginosis diagnosed on Gram-stained reading of the vaginal smears. Examination of further smears, obtained from 176 women at 36 weeks of gestation, showed that those whose vaginal flora was normal initially, and who went to term, rarely developed vaginosis (three of 127, 2.4%). Samples were obtained at 36 weeks gestation from 32 women who had bacterial vaginosis initially, and went to term. In almost 50% (15 of 32) of these a normal lactobacillus-dominated flora had regenerated. Thirty-five women (5%) had initial vaginal smears graded as intermediate. From this group, six of the 17 (35%) women from whom samples were obtained at 36 weeks gestation still had flora of an intermediate pattern; 10(59%) now had normal flora and only one (6%) had developed bacterial vaginosis. Women with bacterial vaginosis were more likely to be culture-positive for M. hominis than those with normal flora (34/78 versus 10/563, odds ratio 42.73 (18.9 to 102.3) P < 0.001), or to be culture-positive for G. vaginalis than those with normal flora (35/78 versus 21/563, odds ratio 21.0 (10.75 to 41.2) P < 0.001). CONCLUSION: Pregnant women do not commonly develop bacterial vaginosis after 16 weeks gestation, and if present, it remits spontaneously in approximately half of those who reach term. As bacterial vaginosis is associated with increased rates of second trimester miscarriage and preterm delivery, any treatment aimed at its eradication in pregnancy should be given no later than the beginning of the second trimester of pregnancy.
OBJECTIVE: To evaluate the role of Ureaplasma urealyticum (Uu) in the pathogenesis of Reiter's syndrome (RS). METHODS: Infection with Uu was determined in 31 patients with RS and 28 patients with other arthritides by urethral, cervical and synovial fluid (SF) culture and by measuring anti-Uu serum antibody. Infection with Chlamydia trachomatis was determined by examining SF by a direct immunofluorescence technique, by a polymerase chain reaction and by measuring anti-C. trachomatis serum antibody. The proliferative response of SF and peripheral blood mononuclear cells (PBMC) to Uu antigens in patients with RS was compared to that of a control group. The effect that treatment of 6 patients with RS with ciprofloxacin had on repeated cultures, on titer of anti-Uu antibody and on mononuclear cell reactivity was measured sequentially. RESULTS: The colonization rate of Uu in patients with RS (74%) was significantly greater than in patients with other arthritides (14%). Genital C. trachomatis isolation and serum anti-C. trachomatis antibody were uncommon in both groups (11 and 13%, respectively). SF mononuclear cells of the patients with RS proliferated specifically in response to Uu antigens [up to 6.9 stimulation index (SI)], as did their PBMC (up to 14.5 SI). In some patients, high anti-Uu antibody titers were measured in the serum. Clinical remission was observed in 4 of 6 patients and correlated with eradication of Uu, decrease in antibody titers and disappearance of mononuclear cell reactivity to Uu antigens. CONCLUSION: Our findings suggest that Uu might be a causative agent or a trigger in the development of sexually acquired RS.
Chlamydia trachomatis is known to be a cause of acute non-gonococcal urethritis (NGU), though the aetiology of this disorder is not fully understood. Mycoplasma genitalium has been isolated from a few men with NGU, but culture has remained difficult and reliable detection became possible only with a specific polymerase chain reaction (PCR). We have used the PCR to examine the role of M genitalium in NGU. M genitalium was detected in urethral samples from 24 (23%) of 103 men with symptoms, signs, or both, of acute NGU, but from only 3 (6%) of 53 men without NGU (p < 0.006). This association was independent of the presence of C trachomatis and could not be explained by differences in age, ethnic, origin, lifetime number of sexual partners or a change in sexual partner during the previous 3 months. The clinical response of the mycoplasma-positive men to doxycycline treatment was at least as satisfactory as that of the chlamydia-positive men. These findings suggest that the association of M genitalium with NGU is likely to be causal, a notion consistent with the known virulence characteristics of this microorganism and its ability to cause urethritis in male sub-human primates.
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Mycoplasmas have been suggested as a co-factor to explain various puzzling features of infection by human immunodeficiency virus 1 (HIV-1). We sought Mycoplasma fermentans by means of a semi-nested polymerase chain reaction (PCR) in samples of peripheral-blood mononuclear cells (PBMC), throat swabs, and urine samples from 117 HIV-seropositive patients (of whom 114 were homosexual men). M fermentans was detected in 12 (10%) PBMC samples, 15 (23%) of 65 throat samples, and 4 (8%) of 55 urine samples from the seropositive subjects. The organism was detected in similar proportions among 73 HIV-seronegative patients recruited from a sexually transmitted diseases clinic (9%, 20%, and 6%, respectively); again, most of the men (40 of 50) in this group were homosexual. We found no association between infection by the mycoplasma and stage of disease, CD4 count, or HIV-1 load. These findings do not, however, eliminate the possibility that the mycoplasmal infection could affect the speed of disease progression.
A survey of previous evidence for the intracellular localization of mycoplasmas within nonphagocytic cells indicated that it was insufficient to conclude unequivocally that such localization occurred. Illustrations of the seemingly intracellular existence of Mycoplasma fermentans in the tissues of patients with AIDS and other patients rekindled interest in the topic of mycoplasmal entrance into epithelial cells. Accordingly, the "incognitus" and PG18 strains of M. fermentans were sought and demonstrated within HeLa cells by electron microscopy following treatment of the cell cultures with gold-labeled antiserum specific to the mycoplasma, together with ruthenium red staining. The phenomenon is not unique to this mycoplasma, being demonstrated also with Mycoplasma hominis. In hindsight, some of the earlier investigators who hinted at intracellular localization were probably correct in doing so.