Virulence gene transcription, phylogroups, and antibiotic resistance of cervico-vaginal pathogenic E. coli in Mexico.

The pathogenicity of Escherichia coli strains that cause cervico-vaginal infections (CVI) is due to the presence of several virulence genes. The objective of this study was to define the variability regarding the genotype of antibiotic resistance, the transcription profiles of virulence genes after in vitro infection of the vaginal cell line A431 and the phylogroup composition of a group of cervico-vaginal E. coli strains (CVEC). A total of 200 E. coli strains isolated from Mexican women with CVI from two medical units of the Mexican Institute of Social Security were analysed. E. coli strains and antibiotic resistance genes were identified using conventional polymerase chain reaction (PCR), and phylogroups were identified using multiplex PCR. Virulence gene transcription was measured through reverse-transcriptase real-time PCR after infection of the vaginal cell line A431. The most common antibiotic resistance genes among the CVEC strains were aac(3)II, TEM, dfrA1, sul1, and qnrA. The predominant phylogroup was B2. The genes most frequently transcribed in these strains were fimH, papC, irp2, iroN, kpsMTII, cnf1, and ompT, mainly in CVEC strains isolated from chronic and occasional vaginal infections. The strains showed a large diversity of transcription of the virulence genes phenotype and antibiotic resistance genotype, especially in the strains of phylogroups, B2, A, and D. The strains formed 2 large clusters, which contained several subclusters. The genetic diversity of CVEC strains was high. These strains have a large number of transcription patterns of virulence genes, and one-third of them carry three to seven antibiotic resistance genes.

Development, validation and testing costs of an in-house real-time PCR assay for the detection of Chlamydia trachomatis.

PURPOSE: To improve the screening of Chlamydia trachomatis(C. trachomatis) in Brazil, an accurate and affordable method is needed. The objective of this study was to develop and assess the performance and costs of a new in-house real-time PCR (qPCR) assay for the diagnosis of C. trachomatis infection. METHODOLOGY: Asymptomatic women aged 14-25 years who attended primary health services in Manaus, Brazil, were screened for C. trachomatis using the Digene Hybrid Capture II CT-ID (HCII CT-ID) DNA test. A subset of cervical specimens were tested using an in-house qPCR and a commercial qPCR, ArtusC. trachomatis Plus RG PCR 96 CE (Artus qPCR) kit, as a reference test. A primer/probe based on the sequence of cryptic plasmid (CP) was designed. An economic evaluation was conducted from the provider's perspective. RESULTS: The primers were considered specific for C. trachomatis because they did not amplify any product from non-sexually transmitted bacterial species tested. Overall, 292 specimens were tested by both the commercial kit (Artus qPCR) and the in-house qPCR. Of those, one resulted in no amplification and was excluded from the analysis. The sensitivity, specificity, and positive and negative predictive values of the in-house qPCR were 99.5 % [95 % confidence interval (CI): 97.1-100], 95.1 % (95 % CI: 89-98.4), 97.4 % (95 % CI: 94-99.1) and 99.0 % (95 % CI: 94.5-100), respectively. The cost per case of C. trachomatis was £0.44 ($0.55) for HCII CT-ID, £1.16 ($1.45) for Artus qPCR and £1.06 ($1.33) for in-house qPCR. CONCLUSION: We have standardized an in-house qPCR to detect cervical C. trachomatis targeting CP. The in-house qPCR showed excellent accuracy and was more affordable than the commercial qPCR kit.

Comparison of Mycoplasma IES, Mycofast Revolution and Mycoplasma IST2 to detect genital mycoplasmas in clinical samples.

INTRODUCTION: Culture is regarded as the gold standard for the detection of genital mycoplasma in clinical samples. Commercially available diagnostic kits, based on liquid broth cultures, provide interesting alternatives to conventional culture. We assessed the laboratory performances of Mycoplasma IES (IES), the Mycofast Revolution (REV) and Mycoplasma IST 2 (IST2) compared to A7 agar plates for the detection of Ureaplasma urealyticum and Mycoplasma hominis in clinical samples. METHODOLOGY: From April to July 2013, endocervical or vaginal samples were collected from sexually active women with abnormal vaginal discharge. Each specimen was tested in parallel using the three commercial kits and the A7 agar plates. RESULTS: A total of 303 samples were included in this study, 35.6% (108/303) of which were positive on A7 plates. Sensitivities for the detection of U. urealyticum of IES, REV and IST2 were 100%, 96.2% and 95.3%, respectively while those for M. hominis were of 92.8%, 92.8% and 85.7%, respectively. Specificity was 100% for the 3 methods. Concerning antimicrobial susceptibility testing, full agreement between IES and REV was documented. CONCLUSIONS: The Mycoplasma IES kit was found to be equivalent or superior compared to other commercial culture-based assays for a rapid and accurate identification of U. urealyticum and M. hominis and detection of resistance. It might be considered a cost-effective tool for detection of these organisms, particularly attractive in developing countries.

Evaluation of a dilution method for non-evaluable results in the detection of Chlamydia trachomatis and Neisseria gonorrhoeae with the Cobas 4800 platform. / Valoración de un método de dilución para la resolución de resultados no valorables en la detección de Chlamydia trachomatis y Neisseria gonorrhoeae con la plataforma cobas 4800.

INTRODUCTION: A variable percentage of samples analysed using the Cobas 4800 assay can give an invalid result by PCR inhibition or erroneous due to incorrect DNA extraction with the Cobas 4800 CT/NG test. METHOD: An analysis was performed using the vortex agitation and dilution protocol on the original sample (swab or urine) for a total of 116 samples. In order to analyse the sensitivity of this method, 100 samples (swabs and urine) with known results were retested. RESULTS: A total of 98.3% (114/116) of the samples analysed were resolved with this protocol with 100% agreement after reviewing clinical data, Gram stain, and other samples analysed in parallel from the same patient. DISCUSSION: The data indicate no loss of sensitivity with this protocol; thus Cobas 4800 users could use this method without the need for alternative methods.

Novel cost-effective quality control approach for the Cepheid Xpert CT/NG assay for the detection of Chlamydia Trachomatis and Neisseria Gonorrhoeae.

The Xpert CT/NG is a rapid assay for detection of Neisseria gonorrhoeae and Chlamydia trachomatis. QC materials must be formulated to emulate human specimens, and are prohibitively expensive. A creative, cost-effective QC approach is proposed. The acceptable sample types for the Xpert CT/NG assay were extended to include eye swabs.

Chlamydia trachomatis infection in HIV-infected women: need for screening by a sensitive and specific test.

Reproductive tract infection (RTIs)/sexually transmitted infections (STIs) are recognized as a major public health problem, particularly due to their relationship with HIV infection. Early detection and treatment of Chlamydia trachomatis infection (CTI) among HIV-infected and HIV-uninfected women may impact heterosexual HIV transmission. A total of 120 participants were enrolled: 30 HIV seropositive women with symptoms of RTIs, 30 HIV seropositive women without symptoms of RTIs, 30 HIV seronegative women with symptoms of RTIs, and 30 HIV seronegative women without symptoms of RTIs. One endocervical swab was collected from all participants and CTI was detected by real-time PCR (COBAS TaqMan CT Test, v2.0). CTI was detected in 4 (6.67%) HIV-infected women and in 1 (1.67%) HIV-uninfected woman (OR 4.214; 95% CI 0.457-38.865). Vaginal discharge was present in almost half of HIV-infected and HIV-uninfected women; lower abdominal pain was present in 11 (18.3%) of HIV-infected and in 9 (15%) of HIV-uninfected women. This study showed that CTI is more prevalent among HIV-infected females as compared to HIV-uninfected females. As the use of real-time PCR is not feasible in most hospitals, efforts should be made to develop a simple, sensitive, and specific test to identify women with CTI for prevention of sequelae and HIV transmission.

Assessment of best single sample for finding chlamydia in women with and without symptoms: a diagnostic test study.

OBJECTIVE: To compare vulvovaginal swabs with endocervical swabs as optimal diagnostic sample for detection of Chlamydia trachomatis infection. DESIGN: A diagnostic test study. SETTING: An urban sexual health centre. PARTICIPANTS: 3973 women aged ≥ 16 years requesting testing for sexually transmitted infections. INTERVENTIONS: Participants took a vulvovaginal swab before routine examination, and clinicians took an endocervical swab during examination. MAIN OUTCOME MEASURE: Diagnosis of chlamydia infection with samples analysed using the Aptima Combo-2 assay; positive results confirmed with the Aptima CT assay. RESULTS: Of the 3973 participants, 410 (10.3%) were infected with C trachomatis. Infected women were significantly younger (22 v 25 years, P<0.0001) and more likely to have symptoms suggestive of a bacterial sexually transmitted infection (53% v 41%, odds ratio 1.63 (95% CI 1.30 to 2.04)), be a contact of someone with a sexually transmitted infection (25% v 5%, odds ratio 6.18 (4.61 to 8.30)), clinically diagnosed with cervicitis (17% v 4%, odds ratio 4.92 (3.50 to 6.91)), and have pelvic inflammatory disease (9% v 3%, odds ratio 2.85 (1.87 to 4.33)). When women co-infected with gonorrhoea were included in the analysis, there was an association with mixed ethnicity (10% v 7%, odds ratio 1.53 (1.07 to 2.17)); but when those with gonorrhoea were removed, women of white ethnicity were significantly more likely to have chlamydia (85% v 80%, odds ratio 1.40 (1.03 to 1.91)). On analysis of complete paired results, vulvovaginal swabs were significantly more sensitive than endocervical swabs (97% (95% CI 95% to 98%) v 88% (85% to 91%), P<0.00001); corresponding specificities were 99.9% and 100%. In women with symptoms suggestive of a bacterial sexually transmitted infection, vulvovaginal swabs were significantly more sensitive than endocervical swabs (97% (93% to 98%) v 88% (83% to 92%), P=0.0008), as they were in women without symptoms (97% (94% to 99%) v 89% (84% to 93%), P=0.002). CONCLUSIONS: Vulvovaginal swabs are significantly better than endocervical swabs at detecting chlamydia in women with and without symptoms suggestive of sexually transmitted infections. In those with symptoms, using endocervical samples rather than vulvovaginal swabs would have missed 9% of infections, or 1 in every 11 cases of chlamydia. TRIAL REGISTRATION: ISRCTN42867448.

Assessment of self taken swabs versus clinician taken swab cultures for diagnosing gonorrhoea in women: single centre, diagnostic accuracy study.

OBJECTIVE: To compare gonorrhoea detection by self taken vulvovaginal swabs (tested with nucleic acid amplification tests) with the culture of urethral and endocervical samples taken by clinicians. DESIGN: Prospective study of diagnostic accuracy. SETTING: 1 sexual health clinic in an urban setting (Leeds Centre for Sexual Health, United Kingdom), between March 2009 and January 2010. PARTICIPANTS: Women aged 16 years or older, attending the clinic for sexually transmitted infection (STI) testing and consenting to perform a vulvovaginal swab themselves before routine examination. During examination, clinicians took urethral and endocervical samples for culture and an endocervical swab for nucleic acid amplification testing. INTERVENTIONS: Urethra and endocervix samples were analysed by gonococcal culture. Vulvovaginal swabs and endocervical swabs were analysed by the Aptima Combo 2 (AC2) assay; positive results from this assay were confirmed with a second nucleic acid amplification test. MAIN OUTCOME MEASURES: Positive confirmation of gonorrhoea. RESULTS: Of 3859 women with complete data and test results, 96 (2.5%) were infected with gonorrhoea (overall test sensitivities: culture 81%, endocervical swabs with AC2 96%, vulvovaginal swabs with AC2 99%). The AC2 assays were more sensitive than culture (P<0.001), but the endocervical and vulvovaginal assays did not differ significantly (P=0.375). Specificity of all Aptima Combo 2 tests was 100%. Of 1625 women who had symptoms suggestive of a bacterial STI, 56 (3.4%) had gonorrhoea (culture 84%, endocervical AC2 100%, vulvovaginal AC2 100%). The AC2 assays were more sensitive than culture (P=0.004), and the endocervical and vulvovaginal assays were equivalent to each other. Of 2234 women who did not have symptoms suggesting a bacterial STI, 40 (1.8%) had gonorrhoea (culture 78%, endocervical AC2 90%, vulvovaginal AC2 98%). The vulvovaginal swab was more sensitive than culture (P=0.008), but there was no difference between the endocervical and vulvovaginal AC2 assays (P=0.375) or between the endocervical AC2 assay and culture (P=0.125). The endocervical swab assay performed less well in women without symptoms of a bacterial STI than in those with symptoms (90% v 100%, P=0.028), whereas the vulvovaginal swab assay performed similarly (98% v 100%, P=0.42). CONCLUSION: Self taken vulvovaginal swabs analysed by nucleic acid amplification tests are significantly more sensitive at detecting gonorrhoea than culture of clinician taken urethral and endocervical samples, and are equivalent to endocervical swabs analysed by nucleic acid amplification tests. Self taken vulvovaginal swabs are the sample of choice in women without symptoms and have the advantage of being non-invasive. In women who need a clinical examination, either a clinician taken or self taken vulvovaginal swab is recommended.

Comprehensive assessment of sociodemographic and behavioral risk factors for Mycoplasma genitalium infection in women.

BACKGROUND: Neisseria gonorrhoeae and Chlamydia trachomatis are characterized by different risk factors, thus control strategies for each also differ. In contrast, risk factors for Mycoplasma genitalium have not been well characterized. METHODS: Between 2000 and 2006, 1090 women ages 14 to 45 attending the Public Health-Seattle & King County Sexually Transmitted Diseases Clinic in Seattle, WA, underwent clinical examination and computer-assisted survey interview. M. genitalium was detected by transcription mediated amplification from self-obtained vaginal swab specimens. C. trachomatis and N. gonorrhoeae were detected by culture from cervical swab specimens. RESULTS: Prevalent M. genitalium infection was detected in 84 women (7.7%), C. trachomatis in 63 (5.8%), and N. gonorrhoeae in 26 (2.4%). Age <20 and nonwhite race were associated with increased risk for all 3 organisms. In addition, risk for M. genitalium was higher for women with a black partner (adjusted odds ratio [AOR]: 3.4; 95% confidence interval = 1.83-6.29), those never married (AOR: 2.6; 1.08-6.25), using Depo-Provera (AOR: 2.3; 1.19-4.46), and smoking (AOR: 1.7; 1.03-2.83). Drug use, history of STI in the past year, ≤high school education, meeting and having intercourse the same day, anal sex, douching, and hormonal contraception were associated with N. gonorrhoeae or C. trachomatis, but not with M. genitalium. Number of partners was not associated with any of the 3 organisms. CONCLUSIONS: The limited number of risk factors for prevalent infection common to all 3 pathogens suggests that M. genitalium may circulate in different sexual networks than N. gonorrhoeae or C. trachomatis. The predominance of sociodemographic risk factors for M. genitalium, rather than high-risk sexual behaviors, suggests broad-based testing may be the most effective control strategy.

Pooling samples: the key to sensitive, specific and cost-effective genetic diagnosis of Chlamydia trachomatis in low-resource countries.

The aims of this study were to compare the performance characteristics and cost-effectiveness of pooling endocervical samples for screening and diagnosis of Chlamydia trachomatis, and to investigate the prevalence of C. trachomatis infection in women in Leningrad Oblast, Russia. A total of 1500 endocervical samples were tested individually and when pooled in groups of 5 and 10 samples, respectively. A previously evaluated in-house diagnostic polymerase chain reaction (PCR) assay was utilized. The sensitivity and specificity of the PCR were not affected by either pooling strategy. The estimated prevalence of genital C. trachomatis infection was 6.6%, 6.1% and 6.0% based on individually tested samples, and pools of 5 and 10, respectively. For diagnosis of individual samples, the pooling strategies resulted in cost savings of 53.3% (5 samples per pool) and 44.0% (10 samples per pool). Pooling samples for PCR detection of C. trachomatis is an accurate and cost-saving approach for diagnosis and large-scale prevalence studies in St Petersburg, Russia.

Pooling of clinical specimens prior to testing for Chlamydia trachomatis by PCR is accurate and cost saving.

The accuracy and cost savings of pooling specimens prior to testing for Chlamydia trachomatis by PCR were evaluated with genital and urine specimens (n = 2,600). There was a 60% reduction in tests without significant loss of accuracy. The efficiency of pooling vaginal swabs is demonstrated for the first time.

Diagnostic assessment of Mycoplasma genitalium in culture-positive women.

Detection of Mycoplasma genitalium-mediated, chlamydia-negative nongonococcal urethritis and other M. genitalium-linked infectious etiologies has been very challenging. Although M. genitalium is considered a leading cause of genitourinary symptoms in men and women, extreme difficulties in its cultivation due to its highly fastidious nature and the lack of routine and effective diagnostic tests have slowed the generation of clinical data which directly implicate the presence of M. genitalium in disease pathogenesis. In this study, we compared enzyme-linked immunosorbent assays (ELISAs) and immunoblot and PCR assays in M. genitalium culture-positive women over 1 to 3 years of clinical visits to determine the usefulness of independent diagnostic strategies. Furthermore, the value of combinatorial diagnostic assessments is described, which provides insights into the dynamics of M. genitalium-host interactions. Overall, we show that neither ELISA nor PCR, alone or in combination, provides the sensitivity required to confidently predict the existence of viable M. genitalium organisms in cervical and vaginal samples. Additionally, culture-positive women exhibited a range of antibody responsiveness to M. genitalium based upon ELISA and immunoblot assessments, indicating immune diversity among this high-risk population.

An assessment of the Roche Amplicor Chlamydia trachomatis/Neisseria gonorrhoeae multiplex PCR assay in routine diagnostic use on a variety of specimen types.

The Roche Cobas Amplicor Chlamydia trachomatis/Neisseria gonorrhoeae polymerase chain reaction (PCR) assay can simultaneously detect both C. trachomatis and N. gonorrhoeae, and has been cleared by United States Food and Drug Administration (FDA) for the testing of endocervical and urethral swabs and urine specimens. The Amplicor N. gonorrhoeae PCR target sequence is known to be present in some strains of commensal Neisseria species, including N. cinerea and N. subflava, necessitating the use of a second PCR assay to confirm positive results. This study analyses the performance of the assay on 7,007 unselected specimens submitted to the laboratory for the PCR diagnosis of N. gonorrhoeae and C. trachomatis; compares the PCR assay with culture for the detection of N. gonorrhoeae; examines the performance of the assay with specimens from different body sites; and briefly compares two confirmatory PCR assays. Confirmation rates for an initial Amplicor N. gonorrhoeae positive result varied widely by specimen type, ranging from 86.2 per cent for penile/urethral swabs to 5.6 per cent for oropharyngeal swabs, indicating all positive Amplicor N. gonorrhoeae results should be confirmed by a second method to maintain adequate specificity. Overall there was 98.1 per cent agreement between the confirmed PCR assay and culture, with confirmed PCR showing a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 81.7 per cent, 99.5 per cent, 92.7 per cent and 98.5 per cent respectively, compared with N. gonorrhoeae culture. When confirmed C. trachomatis/N. gonorrhoeae PCR assay performance was analysed against culture using only FDA-cleared specimens (553 penile/ urethral swabs, urines and cervical/vaginal swabs), sensitivity, specificity, PPV and NPV and percent agreement were 96.7 per cent, 99.8 per cent, 98.9 per cent, 99.4 per cent and 99.3 per cent respectively. No significant differences were found between the two confirmatory PCR assays used during the study period. Limitations of Amplicor for the detection of N. gonorrhoeae and the appropriate use of combined C. trachomatis/N. gonorrhoeae PCR in a routine diagnostic setting are discussed.

Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections--2002.

Since publication of CDC's 1993 guidelines (CDC, Recommendations for the prevention and management of Chlamydia trachomatis infections, 1993. MMWR 1993;42[No. RR-12]:1-39), nucleic acid amplification tests (NAATs) have been introduced as critical new tools to diagnose and treat C. trachomatis and Neisseria gonorrhoeae infections. NAATs for C. trachomatis are substantially more sensitive than previous tests. When using a NAAT, any sacrifice in performance when urine is substituted for a traditional swab specimen is limited, thus reducing dependence on invasive procedures and expanding the venues where specimens can be obtained. NAATs can also detect both C. trachomatis and N. gonorrhoeae organisms in the same specimen. However, NAATs are usually more expensive than previous tests, making test performance from an economic perspective a key consideration. This report updates the 1993 guidelines for selecting laboratory tests for C. trachomatis with an emphasis on screening men and women in the United States. (In this report, screening refers to testing persons in the absence of symptoms or signs indicating C. trachomatis or N. gonorrhoeae infection.) In addition, these guidelines consider tests from an economic perspective and expand the previous guidelines to address detection of N. gonorrhoeae as well as C. trachomatis infections. Because of the increased cost of NAATs, certain laboratories are modifying manufacturers' procedures to improve test sensitivity without incurring the full cost associated with screening with a NAAT. Such approaches addressed in these guidelines are pooling of specimens before testing with a NAAT and additional testing of specimens whose non-NAAT test result is within a gray zone. This report also addresses the need for additional testing after a positive screening test to improve the specificity of a final diagnosis. To prepare these guidelines, CDC staff identified pertinent concerns, compiled the related literature published during 1990 or later, prepared tables of evidence, and drafted recommendations. Consultants, selected for their expertise or disciplinary and organizational affiliations, reviewed the draft recommendations. These final guidelines are the recommendations of CDC staff who considered contributions from scientific consultants. These guidelines are intended for laboratorians, clinicians, and managers who must choose among the multiple available tests, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients.

The microbiological effects of endovaginal sonographic assessment of cervical length.

OBJECTIVE: To determine whether performance of endovaginal sonography for the measurement of cervical length results in a statistically significant change in endocervical culture results. METHODS: Women attending a routine prenatal clinic were offered enrollment in the study. Exclusion criteria included the presence of a cervical cerclage, vaginal examination or coitus within the preceding 24 hours, antibiotic therapy within the preceding 7 days, or the presence of ruptured membranes. A sterile speculum examination and collection of cervical cultures were performed before (initial) and immediately after (final) endovaginal sonographic measurement of cervical length. Quantitative cultures were completed and evaluated for differences in growth by a standardized 4-quadrant technique. RESULTS: A total of 25 women enrolled and completed the study protocol. Quantitative assessment of colony growth showed that the mean growth in the initial samples +/- SD was 3.48+/-1.74, with 1+ indicating growth in 1 quadrant; 2+, growth in the first and second quadrants; 3+, growth in the first, second, and third quadrants; and 4+, growth in all quadrants. The mean growth cultured in the final sample was 3.79+/-2.26 (P = .364; 95% confidence interval of the difference, -1.00 to +381). CONCLUSIONS: The results of this study do not show a statistically significant inoculation effect associated with performance of endovaginal sonography for the measurement of cervical length.

The natural course of asymptomatic Chlamydia trachomatis infections: 45% clearance and no development of clinical PID after one-year follow-up.

The natural course of asymptomatic Chlamydia trachomatis infections in women was studied during one year in a cohort based nested case-control study. Healthy women (n = 744, from four company health services in Amsterdam) with a medical check-up prior to job engagement were included. C. trachomatis-positive women (n = 30, cases) and a randomly selected control group of C. trachomatis-negative women (n = 186, controls) were followed for one year. Urine specimens (at one, six and 12 months) were analysed for the presence of C. trachomatis-DNA and the C. trachomatis-serovars, and questionnaires were filled in. The C. trachomatis prevalence and natural course in relation to demographic and sexual characteristics after one, six and 12 months were studied. The main outcome measures were 1) the prevalence of C. trachomatis using urine specimens; 2) self-reported complaints; 3) clinical symptoms reported to the coordinating physicians. The prevalence of asymptomatic C. trachomatis infections was 4% and there was no correlation with demographic and sexual characteristics. The person/year clearance rate was 44.7% per year. None of the C. trachomatis-positive women developed clinical symptoms or used C. trachomatis specific antibiotic treatment. Women with or without an asymptomatic infection had the same number of self-reported urogenital complaints during follow-up. In persisting infections twice as many C. trachomatis-serovar E infections were detected as compared to clearing infections. Our findings showed that almost half of the asymptomatic C. trachomatis infections in women cleared during one year of follow-up and none developed clinical pelvic inflammatory disease (PID), which is a much lower figure than previously suggested. Therefore these data are important for cost effectiveness calculations in screening programmes for asymptomatic C. trachomatis infections.

Association between abnormal microbiological flora of the lower genital tract in early pregnancy and socio-economic, demographic and environmental risk factors.

BACKGROUND: The main aim of this study was to determine the socioeconomic, demographic and environmental factors which may be associated with the occurrence of pathological microflora of the lower genital tract in early pregnancy. MATERIAL AND METHODS: A group of 96 pregnant women was selected at random from the patients of 10 district maternity units in the Lodz region of Poland. Only singleton pregnancies below 24 weeks were qualified for inclusion in the survey. A standard questionnaire covering medical, socio-economic, demographic, constitutional, and environmental items was administered to every subject and checked against medical records. Based on microbiological results, two groups of pregnant women were distinguished: Group I, with normal cervicovaginal flora, predominantly Lactobacillus spp. with coagulase-negative staphylococci and viridans streptococci, and Group II, with abnormal flora. The latter included two subgroups: IIA, intermediate microbial flora, dominated by M. hominis, U. urealyticum, G. vaginalis, gram-negative anaerobic rods, Ch. trachomatis, and few Lactobacillus spp, and IIB, highly abnormal flora, containing similar microbial components as in IIB but without Lactobacillus spp. RESULTS: Based on the results of microbiological culturing, 18 (18.7%) of the 96 women examined were classified to Group I, and 78 (81.2%) to Group II: 32 (33.3%) in group IIA and 46 (47.9%) in IIB. Groups IIA and IIB were combined for further analysis. An excessive risk of abnormal vaginal flora was observed in connection with such socio-economic factors as marital status, unemployment, and smoking, Moreover, the first pregnancy was also found to be a potential risk factor for this pathology. The risk of developing abnormal vaginal flora, although exceeding unity for each of these factors, was not considered statistically significant. CONCLUSIONS: Socio-economic and environmental factors may influence the course and outcome of pregnancy. Pregnant women who present with risk factors for abnormal cervicovaginal microflora should be included in comprehensive prenatal surveillance, which enables early detection and treatment of this pathology.

Multisite pooling study using ligase chain reaction in screening for genital Chlamydia trachomatis infections.

BACKGROUND: Ligase chain reaction (LCR), a nucleic acid amplification assay, is a highly specific and sensitive test for detecting Chlamydia trachomatis in cervical and urethral swabs as well as first-void urine specimens. GOAL: To examine the suitability of using the LCR test to detect C trachomatis in pooled cervical specimens. STUDY DESIGN: The performance of LCR in pooled specimens was compared with individual specimen testing at six laboratories using 3,170 cervical swab specimens randomly selected from specimens received for routine testing in the participating laboratories. These samples then were combined consecutively into 634 pools of 5 specimens and 317 pools of 10 specimens. A reduced sample to cutoff ratio of 0.2 or more was used for the pooled specimens. RESULTS: Of the 188 positive specimens (98.9%), 186 were identified when single specimens were analyzed. When pools of 5 or 10 specimens were evaluated, 99.5% and 98.9% of the positive swabs, respectively, were identified correctly. Two positive specimens were detected only through pooling. CONCLUSIONS: Pooling samples for detection of C trachomatis by LCR is sensitive and specific. Depending on the prevalence of infection (positivity), LCR testing may result in cost savings, as compared with individual testing of specimens.

NAATs to diagnose Chlamydia trachomatis genital infection: a promise still unfulfilled.

Nucleic acid amplification tests (NAATs) have created a revolution in our ability to diagnose chlamydial infections. They are markedly more sensitive (while maintaining exquisite specificity) than previously used tests. They can be used with noninvasively collected specimens (first-catch urine for men or women and vaginal swabs from women). This allows their use in screening asymptomatic individuals who represent the bulk of prevalent infections. Mishandling of urine specimens can lead to false-negative results and few are aware of that potential for getting incorrect results. The leading deterrent to the acceptance of NAATs has been their perceived cost. This is based on the purchase price of tests and fails to consider the total cost of testing, which also includes costs of specimen collection, where NAATs have a major advantage.