Retrospective study of Chlamydia trachomatis using the polymerase chain reaction on archival Papanicolaou-stained cytologic smears.

OBJECTIVE: To detect chlamydial DNA on archived Papanicolaou-stained (Pap) smears using the polymerase chain reaction (PCR) technique. STUDY DESIGN: A PCR assay was designed to identify chlamydial DNA using consensus sequences unique to the genus Chlamydia in the 16S rRNA gene. This assay produced a 109 base pair product containing a single Pvu II restriction site. One hundred cervicovaginal Pap smears from a teen clinic population were processed for DNA isolation and PCR. Amplifiable DNA was isolated from 93 of the 100 cases as determined by a human growth hormone gene. These specimens were subjected to chlamydial PCR. RESULTS: PCR analysis of the 93 samples yielded 6 that were positive for the chlamydial 16S rRNA sequence. The six positive chlamydial amplicons were purified and subjected to Pvu II restriction enzyme analysis to validate their identity. The analysis confirmed the identity of the products, as a single Pvu II restriction site resulted in 41 base pair and 68 base pair products, as predicted. CONCLUSION: PCR testing for Chlamydia trachomatis can be performed on DNA isolated from archival Pap smears. Using this methodology, 6.5% of young women in our teen clinic population were positive for chlamydial DNA.     

Sensitivity and specificity of the Papanicolaou-stained cervical smear in the diagnosis of Chlamydia trachomatis infection

Two hundred young women had simultaneously prepared cultures for Chlamydia trachomatis and cervical smears; they also completed a questionnaire. Twelve of the chlamydial cultures were positive. There was poor correlation between the culture results and the cytologic morphology or symptoms. On initial blind reading, only 10% of the smears cytologically interpreted as positive were actually positive by culture. Under the most favorable (non-blind) interpretation, only 23% of the smears cytologically interpreted as positive for chlamydial infection were also culture positive. Because of the high incidence of false positives, we conclude that routine cytologic examination of Papanicolaou-stained smears is not an acceptable method for the diagnosis of chlamydial infections of the cervix. Immunoperoxidase staining of duplicate smears did not appear to be a successful replacement for culture.     

Assay of avian leukosis viruses by indirect immunoperoxidase method

Chick embryo fibroblast cells (CEF) infected with avian leukosis viruses were stained selectively by the indirect immunoperoxidase method. Good results were obtained by the use of a successive combination of periodate-lysine-paraformaldehyde fixation and diaminobenzidine reaction mixture. Viral antigens were detected type-specifically on infected cells. Type-specific antisera determined by the neutralization test were absorbed by the homologous type of virus-infected CEF, but not by the heterologous type of these cells. This test was more effective for detecting virus infectivity than the resistance-inducing factor test. Viral antigen was observed 2 days after inoculation with a large amount of the virus. The minimum infective dose of the virus for the antigen detection was 100 resistance-inducing units (RIU) per plate 4 days after infection, or 1 RIU per plate in CEF after two passages.     

Detection of Chlamydia trachomatis by nucleic acid sandwich hybridization

Abstract Chromosomal DNA fragments from Chlamydia trachomatis serotype L2 were shotgun-cloned into pBR322. A C. trachomatis -specific clone was further subcloned to produce specific DNA reagents for the identification of C. trachomatis by nucleic acid sandwich hybridization. The chosen DNA reagents from serotype L2 also hybridized with all the other chlamydial serotypes tested, but not with the DNA from 41 unrelated organisms. The sensitivity of the sandwich hybridization test was 10⁶ DNA molecules. The applicability of the test for routine diagnostic use was demonstrated by a pilot study in which C. trachomatis was directly detected from genital specimens.     

Diagnosis of herpes simplex virus in routine smears by an immunoperoxidase technique

Routine Papanicolaou-stained cervicovaginal smears from 59 patients were cytologically screened for herpetic infection. Forty-one of the smears were positive for herpes, 2 were suspicious and 16 were negative. All 59 slides were then destained and restained by a commercial immunoperoxidase kit for the detection of herpes simplex virus (HSV). The immunoperoxidase stain was positive in 23 of the 41 cytologically positive slides. One of the 2 cytologically suspicious slides was also immunoperoxidase positive, as was 1 of the 16 cytologically negative slides. This study indicates that immunoperoxidase staining is very specific but not quite as sensitive as routine Papanicolaou-stained smears in the detection of HSV. The immunoperoxidase method is thus recommended for the confirmation of HSV cases rather than for the routine diagnosis of HSV infection.     

Prevalence of psammoma bodies in Papanicolaou-stained cervicovaginal smears

Reports from sequential series of 234,318 cervicovaginal smears from a period of three years were reviewed to ascertain the prevalence and significance of psammoma bodies. Seven smears contained psammoma bodies. Three of the seven were associated with benign conditions and four were associated with a cancer (two serous papillary endometrial adenocarcinomas, one ovarian serous cystadenocarcinoma and one serous papillary carcinoma of the peritoneum). The prevalence of psammoma bodies in benign cases was much higher than reported in previous studies, in which most findings of psammoma bodies were associated with malignancy, particularly ovarian carcinoma. A consistent and useful feature in distinguishing psammoma bodies associated with benign or malignant disease was the presence of a few adherent small bland-appearing glandular cells in benign disorders and adherent malignant glandular cells in cases of carcinoma. A more conservative work-up may be merited in young women with clearly benign cells associated with psamoma bodies in a cervicovaginal smear and an otherwise negative physical examination and noncontributory endometrial sampling.     

Significance of anucleated squames in Papanicolaou-stained cervicovaginal smears

The significance of anucleated squames in Papanicolaou-stained cervicovaginal smears as a marker of hyperkeratosis with an underlying significant atypia was evaluated. Over a two-year period, 785 (0.47%) of 168,215 cervicovaginal smears were signed out as demonstrating anucleated squames without any other abnormality. Cytologic or histologic follow-up specimens were available for 304 of those smears (42%). Histology or cytology showed condyloma or a more significant lesion in 13 cases (4.3%); histology showed hyperkeratosis without atypia in 25 cases (8.2%) and chronic cervicitis in 23 (7.5%); follow-up cytology demonstrated persistent anucleated squames in 47 cases (15.4%) and was negative in 196 (64.6%). During this same period, the rate of condyloma or a more significant lesion in all Papanicolaou smears examined was 1.69%. Thus, reporting the presence of anucleated squames in the absence of any other abnormality appears to be of marginal value as a screening procedure for predicting the existence of a significant lesion. Noting their presence in patients with a prior diagnosis of condyloma or dysplasia remains an important tool for detecting a persistent lesion. Lack of standardization among pathologists in the recognition of anucleated squames may partially explain the low predictive value of this finding: an informally conducted survey revealed a mean accuracy of 46% in the identification of true anucleated squames.     

Chlamydia trachomatis detection in cervical PreservCyt specimens from an Irish urban female population

Objective:  The aim of this study was to determine the prevalence of cervical Chlamydia trachomatis infection by polymerase chain reaction (PCR) in urban women undergoing routine cervical cytological screening and to investigate the relationship with age, cytology, smoking status and concurrent human papillomavirus (HPV) infection.
Methods:  A total of 996 women (age range 16–69 years) attending general practitioners for routine liquid-based cervical smear screening in the Dublin area were recruited in the study of prevalence of C. trachomatis . Informed consent was obtained and liquid-based cytology (LBC) specimens were sent for cytological screening. DNA was extracted from residual LBC and tested for C. trachomatis by PCR using the highly sensitive C. trachomatis plasmid (CTP) primers and for HPV infection using the MY09/11 primers directed to the HPV L1 gene in a multiplex format.
Results:  The overall prevalence of C. trachomatis was 5.4%. Prevalence was highest in the <25 years age group (10%). Coinfection with HPV and C. trachomatis occurred in 1% of the screening population. A higher rate of smoking was observed in women positive for C. trachomatis , HPV infections or those with abnormal cervical cytology. Chlamydia trachomatis infection was not associated with abnormal cytology.
Conclusions:  Women (5.4%) presenting for routine cervical screening are infected with C. trachomatis . Opportunistic screening for C. trachomatis from PreservCyt sample taken at the time of cervical cytological screening may be a possible strategy to screen for C. trachomatis in the Irish female population.     

The recognition of Pneumocystis carinii in routine Papanicolaou-stained smears

Using definite criteria it is possible to accurately evaluate routine Papanicolaou-stained cytologic smears for the presence or absence of Pneumocystis carinii. Strict attention must be paid to the cellular environment and the background material intimately associated with the cells. In 133 cytology specimens evaluated from proximal and deep bronchial washings and brushings, 71 were considered positive for P. carinii and 62 were called negative. Ten of the latter were either unsatisfactory or equivocal. The 71 positives correlated in every instance with parallel Grocott methenamine silver-stained transbronchial biopsies or brushings. Fifty-one of the 52 satisfactory cytologic negatives also correlated with the biopsy and brushing findings. There was a single false negative. This high degree of correlation indicates that the Papanicolaou-stained specimen can be a valuable tool in the early diagnosis of pneumocystosis.     

Detection of Chlamydia trachomatis in clinical specimens by nucleic acid spot hybridization

A nucleic acid spot hybridization assay was used to detect Chlamydia trachomatis DNA. The hybridization probes included DNA isolated from elementary bodies of lymphogranuloma venereum (LGV) strains and cloned fragments of both chromosomal and plasmid DNA. The sensitivity of the test was in the range 10 to 100 pg homologous DNA and 10 in vitro infected cells. Cross-reactivity with bacterial DNA was avoided when purified chlamydia-specific DNA fragments were used as probes. C. trachomatis was detectable in most of the clinical specimens with large amounts of infectious particles. Also some isolation-negative specimens gave a positive signal in the test.     

Demonstration of fibronectin in human articular cartilage by an indirect immunoperoxidase technique

Summary Fresh frozen tissue sections of human articular cartilage was treated without and with human testicular hyaluronidase (2×10⁶ units/l) for 60 min at 37° C and stained by the indirect immunoperoxidase technique with rabbit antihuman fibronectin. The rabbit antihuman fibronectin was purified by affinity chromatography on human fibronectin-Sepharose. Fibronectin was only found on the acellular surface of the articular cartilage in tissue sections not treated with hyaluronidase. In this surface layer, probably identical to lamina splendens, the arrangement of fibronectin was as a membrane. No collagen was seen in this area by van Gieson staining. No staining for fibronectin was found in the cartilage matrix or in the chondrocytes. Treatment of the cartilage tissue with hyaluronidase resulted in visualization of high amount of fibronectin in the cartilage matrix, with the highest intensity around the chondrocytes. The staining of the acellular surface layer of the articular cartilage was identical with the results obtained without hyaluronidase treatment. These results indicate that articular cartilage is rich in fibronectin probably in complex with hyaluronic acid, and that the chondrocytes produce fibronectin in situ. It also demonstrates the steric hindrance of hyaluronic acid aggregates in diffusion of the antibody and the value of hyaluronidase treatment of tissue before demonstration of fibronectin.     

Detection of surface-exposed epitopes on Chlamydia trachomatis by immune electron microscopy

The cell surfaces of two Chlamydia trachomatis serovars were explored by immune electron microscopy with monoclonal antibodies that recognize a number of chlamydial outer-membrane components. Species, subspecies and serovar-reactive epitopes on the major outer-membrane protein (MOMP) of a lymphogranuloma venereum biovar strain, L2/434/Bu, and a trachoma biovar strain, F/UW-6/Cx, were exposed on the surfaces of both elementary bodies (EBs) and reticulate bodies (RBs). Three epitopes on MOMP were inaccessible on EBs and RBs of both strains. These included a genus-reactive, species-reactive, and a subspecies-reactive epitope. In contrast, genus-specific epitopes on lipopolysaccharide (LPS) were not detected on the EB surface, but were clearly expressed on RBs of both L2/434/Bu and F/UW-6/Cx chlamydiae. Antibodies specific for the 60 kDa and 12 kDa 'cysteine-rich' outer-membrane proteins did not react with surface epitopes on either EBs or RBs. These data provide evidence that MOMP is a major surface antigen of both morphological forms, whereas some portions of the LPS molecule are exposed on the RB surface but become inaccessible to antibody after conversion to the infectious EB form.     

Evaluation of proposed cytomorphologic criteria for the diagnosis of Chlamydia trachomatis in Papanicolaou smears

To evaluate the proposed cytomorphologic criteria for the cervical cytologic diagnosis of Chlamydia trachomatis infection, a study was made of 171 endocervical smears. All cytomorphologic elements that could be ascribed to Chlamydia trachomatis infection were correlated with the diagnostic confirmation of this microorganism by monoclonal antibody (MAb) staining. The presence of Chlamydia trachomatis was detected in 21 samples (12.28%) by MAb staining. Comparing the cytomorphologic results with the MAb results, the sensitivities and specificities of the Papanicolaou smear diagnoses were 19% and 86% using the cytologic criteria proposed by Gupta and coworkers, 38% and 87% using the criteria proposed by Kiviat and coworkers and 23% and 91% using the criteria proposed by Shiina. In view of (1) its low sensitivity, (2) the subjective elements and individual variations in the proposed cytologic criteria, (3) the similarity with Trichomonas vaginalis-produced exudates and (4) the implications of a misdiagnosis of a sexually transmitted disease, it is concluded that cervical cytology is not useful for ascertaining the presence of Chlamydia trachomatis.     

Chlamydia trachomatis persistence: an update

Chlamydial persistence is a reversible state generated during conditions deleterious to growth. In persistence, Chlamydia trachomatis remains viable but atypical, with an enlarged, aberrant form and quiescent metabolism. It favours chronic chlamydiosis, leading to serious sequelae. Although the mechanism of persistence formation is still unknown, more reliable molecular approaches tend to confirm that its occurs in vivo, even lasting 3 years. One approach consists of identifying unprocessed rRNA found only in viable Chlamydia, when infection is not apparent. Another approach, referring to the fact that immunity is type-specific, consists of showing by genotyping that multiple recurrences are due to the same genovar. At the molecular level, persistence is characterized by increased expression of ct755, one of the three heat shock protein (hsp60)-coding genes. In addition, chromosomal replication occurs continuously, and cell division is blocked possibly due to the repression of genes such as ftsW and amiA. At the immunological level, persistence reveals the failure of host-defence mechanisms because of reduced or suppressed pro-inflammatory or cytotoxic responses.     

Human papillomavirus DNA detection in Papanicolaou-stained cervical smears with a nonradioactive, in situ hybridization assay.

Archived Papanicolaou-stained cervical smears from women with different cervical pathologies were processed for human papillomavirus (HPV) DNA detection and typing with an in situ hybridization (ISH) assay that employed commercial biotinylated HPV DNA probes. Two HPV DNA probes were utilized: one included HPV genotypes 6/11 and the other, 16/18. The method yielded positive results for HPV DNA 6/11 in 5 cases with condylomata acuminata (100%) and in 2 of 47 with flat warty lesions (4.2%), whereas HPV DNA 16/18 was detected in 29/47 of the latter group (61.7%). In cases with cervical intraepithelial III or invasive squamous cell carcinoma the yield was lower: positive results for HPV DNA 16/18 were obtained in only one of the five cases with one or the other cervical pathology (20%). An analysis of the results showed that the sensitivity of the assay correlated with evidence in the Papanicolaou specimens of pathognomonic cell injury from HPV infection. In the presence of such cytologic features, HPV DNA typing was possible in 37/52 cases (65.4%). In view of the modest difficulty and relatively quick execution of the nonradioactive ISH assay, the authors believe that Papanicolaou cervical smears with cytologic changes of HPV infection could be processed by this method in order to acquire information on the HPV type or types involved in the cervical infection.     

Purification of Chlamydia trachomatis by a simple and rapid filtration method

A simple method for filter purification of Chlamydia trachomatis from cell culture is described. Crude homogenates of chlamydiae-infected cells were passed through a glass prefilter and a 0.6 microns pore diameter polycarbonate filter. The filtrate was then passed through a 0.2 microns pore diameter filter on which the chlamydiae were trapped. This filter was then back-washed to collect the organisms. These procedures removed cell debris and soluble protein, and yielded particles with a narrow size distribution. The mean yield of viable chlamydiae purified by filtration was 64% when the filters were washed at each stage of the process.     

Detection by multiplex polymerase chain reaction and typing of Chlamydia trachomatis isolates

Abstract The multiplex polymerase chain reaction (PCR) was applied for the detection of the Chlamydia trachomatis chromosome and plasmid. The multiplex PCR demonstrated a sensitivity of 0.8 fg of chlamydial DNA, corresponding to the detection of about 5 copies of the plasmid. Analysis of 195 genital specimens collected randomly from a female population, showed that the multiplex PCR is more sensitive and rapid than culturing for detecting Chlamydia trachomatis . Moreover, sequencing of the II variable domain of the ompl gene, directly from DNA of the clinical specimens, appears to be a simple and rapid method for determining serovar isolates.