Specific immunofluorescent staining of pathogenic treponemes with a monoclonal antibody

Specific detection of Treponema pallidum in clinical samples: validation of a qPCR assay combining two genomic targets

OBJECTIVES

We evaluated a real-time quantitative PCR (qPCR) for detection of the Treponema pallidum (TP) genome in clinical samples through simultaneous detection of two genomic targets.

METHODS

We performed qPCR with TaqMan technology using two TP genes, polA and tpp47, as targets, with an internal positive control. The qPCR assay was compared with syphilis diagnosis based on a combination of clinical examination, serological results and inhouse nested PCR (nPCR). Samples were analysed at the National Reference Center for STIs at Cochin Hospital in Paris.

RESULTS

In total, from October 2010 to December 2016, 320 documented clinical samples (mucosal and cutaneous swabs) were collected from patients with or without syphilis attending STI centres in France. The qPCR had an overall sensitivity of 89% (95% CI 85.1% to 92.1%), a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 88% (95% CI 84.3% to 91.5%). The agreement between qPCR and nPCR results was 94% (κ=0.88, 95% CI 0.83 to 0.93). Calibration of the qPCR assay, by cloning both the polA and tpp47 genes, defined the detection threshold as 1 copy/µL of DNA elution.

CONCLUSIONS

We validated a new qPCR for detecting the TP genome in clinical samples with excellent sensitivity and specificity. The cloning of polA and tpp47 genes for calibration would be interesting in the evaluation of bacterial loads in samples.

Case report of gastric syphilis in Korea: Clinical features, pathology, management, and prognosis

RATIONALE

Syphilis is a contagious infectious disease caused by Treponema pallidum. Gastric involvement of syphilis is rare and has nonspecific gastrointestinal symptoms and endoscopic findings. To date, 16 cases have been reported in Korea. Here, we report 2 additional cases of gastric syphilis in men in their 30 second.

PATIENTS CONCERNS

Two 35- and 33-year-old men presented with epigastric pain.

DIAGNOSIS

The serum venereal disease research laboratory and fluorescent treponemal antibody absorption tests were positive. Esophagogastroduodenoscopy showed multiple variable-sized flat elevated lesions and geographic ulcers with whitish exudates in the antrum and body. Warthin-Starry silver staining of endoscopic biopsy specimens confirmed gastric syphilis.

INTERVENTIONS

The patients were treated with an intramuscular injection of 2.4 million units of benzathine penicillin once a week for 3 weeks.

OUTCOMES

Clinical symptoms and gastric lesions were completely resolved.

LESSONS

First, gastric syphilis, despite its rarity and nonspecific symptoms and endoscopic findings, should be considered in a rare extracutaneous presentation of syphilis. Second, a high index of clinical suspicion and an accurate diagnosis based on a combination of clinical, radiological, endoscopic, serologic, and histopathologic findings provide an opportunity to identify and treat patients with gastric syphilis.

Laboratory Diagnostic Tools for Syphilis: Current Status and Future Prospects

With the increasing number of patients infected with syphilis in the past 20 years, early diagnosis and early treatment are essential to decline syphilis prevalence. Owing to its diverse manifestations, which may occur in other infections, the disease often makes clinicians confused. Therefore, a sensitive method for detecting T. pallidum is fundamental for the prompt diagnosis of syphilis. Morphological observation, immunohistochemical assay, rabbit infectivity test, serologic tests, and nucleic acid amplification assays have been applied to the diagnosis of syphilis. Morphological observation, including dark-field microscopy, silver-staining, and direct fluorescent antibody staining for T. pallidum, can be used as a direct detection method for chancre specimens in primary syphilis. Immunohistochemistry is a highly sensitive and specific assay, especially in the lesion biopsies from secondary syphilis. Rabbit infectivity test is considered as a sensitive and reliable method for detecting T. pallidum in clinical samples and used as a historical standard for the diagnosis of syphilis. Serologic tests for syphilis are widely adopted using non-treponemal or treponemal tests by either the traditional or reverse algorithm and remain the gold standard in the diagnosis of syphilis patients. In addition, nucleic acid amplification assay is capable of detecting T. pallidum DNA in the samples from patients with syphilis. Notably, PCR is probably a promising method but remains to be further improved. All of the methods mentioned above play important roles in various stages of syphilis. This review aims to provide a summary of the performance characteristics of detection methods for syphilis.

Bacteria in the apical root canals of teeth with apical periodontitis

BACKGROUND/PURPOSE

Bacteria in the tooth root canal may cause apical periodontitis. This study examined the bacterial species present in the apical root canal of teeth with apical periodontitis. Antibiotic sensitivity tests were performed to evaluate whether these identified bacterial species were susceptible to specific kinds of antibiotics.

METHODS

Selective media plating and biochemical tests were used first to detect the bacterial species in samples taken from the apical portion of root canals of 62 teeth with apical periodontitis. The isolated bacterial species were further confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

RESULTS

We found concomitant presence of two (32 teeth) or three species (18 teeth) of bacteria in 50 (80.6%) out of 62 tested teeth. However, only 34 bacterial species were identified. Of a total of 118 bacterial isolates (83 anaerobes and 35 aerobes), Prophyromonas endodontalis was detected in 10; Bacteroides, Dialister invisus or Fusobacterium nucleatum in 9; Treponema denticola or Enterococcus faecalis in 8; Peptostreptococcus or Olsenella uli in 6; and Veillonella in 5 teeth. The other 25 bacterial species were detected in fewer than five teeth. Approximately 80-95% of bacterial isolates of anaerobes were sensitive to ampicillin/sulbactam (Unasyn), amoxicillin/clavulanate (Augmentin), cefoxitin, and clindamycin. For E. faecalis, 85-90% of bacterial isolates were sensitive to gentamicin and linezolid.

CONCLUSION

Root canal infections are usually caused by a mixture of two or three species of bacteria. Specific kinds of antibiotic can be selected to control these bacterial infections after antibiotic sensitivity testing.

The endemic treponematoses

The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents.

Comparative analysis of immunohistochemistry, polymerase chain reaction and focus-floating microscopy for the detection of Treponema pallidum in mucocutaneous lesions of primary, secondary and tertiary syphilis

BACKGROUND

The incidence of syphilis is increasing in many parts of the world including a re-emergence in Western Europe and North America. Depending on the disease stage, direct detection of Treponema pallidum in mucocutaneous lesions of syphilis may be difficult and histopathological findings are not always straightforward. Thus, the correct histological diagnosis may be challenging.

OBJECTIVES

Comparatively to evaluate the evidence for infection with T. pallidum by immunohistochemistry (IHC), polymerase chain reaction (PCR) and focus-floating microscopy (FFM).

METHODS

A series of 86 paraffin-embedded skin biopsy samples from patients with primary, secondary or tertiary syphilis was assessed for detection of T. pallidum by IHC and FFM; 45 specimens were also investigated by a T. pallidum-specific PCR analysis. Histopathological reaction patterns and number and distribution of treponemes were studied, and all data were re-evaluated by clinicopathological correlation.

RESULTS

Using a polyclonal antibody directed against T. pallidum, we detected the presence of T. pallidum by IHC in 42/86 (49%) samples [6/9 (67%) primary, 34/62 (55%) secondary and 2/15 (13%) tertiary syphilis]. T. pallidum-specific DNA was detected in 31/45 (69%) specimens [4/4 (100%) primary, 26/34 (76%) secondary and 1/7 (14%) tertiary syphilis]. In comparison, FFM analysis resulted in an overall detection rate of 82/86 (95%) [9/9 (100%) primary, 60/62 (97%) secondary and 13/15 (87%) tertiary syphilis]. Significant differences were observed concerning amount and distribution of organisms (epitheliotropic vs. endotheliotropic) in correlation to the three disease stages and to histopathological reaction patterns.

CONCLUSIONS

FFM is a highly sensitive and specific method to detect T. pallidum in tissue from mucocutaneous syphilis lesions. Our results indicate that a combination of PCR and FFM, as the most sensitive approach, could provide an additional benefit for the histopathological diagnosis of (late) secondary and tertiary syphilis and may be helpful in cases where serological testing of T. pallidum antibodies has failed, but the clinical suspicion for syphilis remains.

Gastric syphilis: a systematic review of published cases of the last 50 years

The authors conducted a systematic review of the English literature for cases of Gastric Syphilis (GS) in the last 50 years. The 34 studies which met selection criteria included 52 patients with GS. Of the reviewed patients, only 13% had a history of syphilis diagnosis and 46% had prior or concurrent clinical manifestations of the disease. Epigastric pain/fullness was the most common presenting symptom (92%) and epigastric tenderness being the most common sign. Gastric bleeding of variable intensity was documented in 35% of the cases. In the radiologic examinations, fibrotic narrowing and rigidity of the gastric wall was the most common finding (43%), followed by hypertrophic and irregular folds, while in endoscopy the most common lesion types were multiple ulcerations (48%), nodular mucosa, and erosions. The antrum was the most commonly affected area (56%). The majority of the patients received penicillin (83%) with a rapid resolution of their symptoms. Seventeen percent of the patients were treated surgically either due to a complication or due to strong suspicion of infiltrating tumor or lymphoma. The nonspecific clinical, radiologic, and pathologic characteristics of GS can establish it as a great imitator of other gastric diseases. GS should be considered in the differential diagnosis in patients at risk for sexually transmitted diseases who present with abdominal complaints and unusual endoscopic lesions and no other diagnosis is made, irrespective of the presence of H. pylori. The absence of primary or secondary luetic lesions should not deter one from considering GS.

Cerebral syphilitic gummata: a case presentation and analysis of 156 reported cases

OBJECTIVE

Cerebral syphilitic gummata are rare manifestations of tertiary, meningovascular syphilis. No extensive characterization of these lesions has been published recently, and only a few small reviews containing imaging findings have been published to date. To better characterize cerebral gummata, we present a case seen at Tulane University, followed by an extensive review of the literature.

CLINICAL PRESENTATION

A 56-year-old man with a history of treated syphilis presented with seizures and confusion. A rapid plasma reagin titer was reactive in serum but Venereal Disease Research Laboratory results were negative in cerebrospinal fluid. Neuroimaging demonstrated an occipital lesion and the patient underwent subtotal resection. The pathological examination demonstrated a syphilitic gumma containing Treponema pallidum visualized by fluorescence immunostaining.

METHODS

An extensive literature search was performed for published case reports of cerebral gummata.

RESULTS

One hundred fifty-six cases containing 185 lesions were located. Patients presented with signs and symptoms based on location. Lesions are more common in men (64%) and those aged 18 to 39 years. Cerebrospinal fluid syphilis tests were positive in 64%. Lesions are located everywhere but are most common on the convexities (66%). Computed tomography usually reveals a hypodense lesion that enhances. Magnetic resonance imaging usually demonstrates hypointensity on T1, hyperintensity on T2, and enhancement with gadolinium. Most patients are responsive to antiluetic therapy, with the majority demonstrating complete or near-complete imaging and symptom resolution.

CONCLUSION

Cerebral gummata are rare lesions. Intravenous penicillin G with imaging follow-up is recommended for most patients. Surgery should be reserved for those unresponsive to antibiotics or those with acutely elevated intracranial pressure.

Molecular characterization of syphilis in patients in Canada: azithromycin resistance and detection of Treponema pallidum DNA in whole-blood samples versus ulcerative swabs

Although detection of Treponema pallidum DNA in whole-blood specimens of syphilis patients has been reported, it is uncertain at what stage of the disease such specimens are most suitable for the molecular diagnosis of syphilis. Also, few studies have directly compared the different gene targets for routine laboratory diagnostic usage in PCR assays. We examined 87 specimens from 68 patients attending two urban sexually transmitted disease clinics in Alberta, Canada. PCR was used to amplify the T. pallidum tpp47, bmp, and polA genes as well as a specific region of the 23S rRNA gene linked to macrolide antibiotic susceptibility. In primary syphilis cases, PCR was positive exclusively (75% sensitivity rate) in ulcerative swabs but not in blood specimens, while in secondary syphilis cases, 50% of the blood specimens were positive by PCR. Four out of 14 (28.6%) of our PCR-positive syphilis cases were found to be caused by an azithromycin-resistant strain(s). Our results confirmed that swabs from primary ulcers are the specimens of choice for laboratory diagnostic purposes. However, further research is required to determine what specimen(s) would be most appropriate for molecular investigation of syphilis in secondary and latent syphilis.

Cerebral syphilitic gumma in HIV-infected patients: case report and review

Neurosyphilis presenting as a cerebral gumma is an uncommon event. To date there are seven cases of cerebral gumma reported in human immunodeficiency virus (HIV)-infected patients. We describe a HIV-infected patient with neurosyphilis presenting as an expanding central nervous system lesion and unremarkable cerebrospinal fluid analysis. This case report illustrates the clinical and therapeutic aspects of syphilitic gumma in HIV-infected patients.

Diagnosing Treponema pallidum in Secondary Syphilis by PCR and Immunohistochemistry

Epidemiological aspects of syphilis in Western countries have undergone a significant change with respect to the number of cases. Detection of Treponema pallidum is difficult, and the correct diagnosis of secondary syphilis can be critical. In this study, biopsy samples from skin lesions of 12 patients with secondary syphilis were used. Diagnosis of syphilis was based on clinical presentation, dark-field microscope analysis, and serological tests. Using a polyclonal antibody directed against T. pallidum, we show the presence of T. pallidum in 90% of the samples studied with the bacteria located in the epidermis and the upper dermis. The T. pallidum 47-kDa surface protein gene could be amplified by PCR in 75% of the skin lesions. When combining both techniques, T. pallidum was detected in 92% of the samples from patients with secondary syphilis but not in the control samples. Our work suggests that both immunohistochemistry and PCR could be useful for the diagnosis of secondary syphilis and may be helpful in some rare cases when serological assays failed to detect T. pallidum antibodies.

Monoclonal Antibodies Against LipL32, The Major Outer Membrane Protein of PathogenicLeptospira: Production, Characterization, and Testing in Diagnostic Applications

Pathogenic serovars of Leptospira have a wide antigenic diversity attributed mainly to the lipopolysaccharide present in the outer membrane. In contrast, antigens conserved among pathogenic serovars are mainly represented by outer membrane proteins. Surface exposure of a major and highly conserved outer membrane lipoprotein (LipL32) was recently demonstrated on pathogenic Leptospira. LipL32 in its recombinant form (rLipL32) was used to immunize BALB/c mice to develop murine monoclonal antibodies (MAbs). Three MAbs against rLipL32 were produced, isotyped, and evaluated for further use in diagnostic tests of leptospirosis using different approaches. MAbs were conjugated to peroxidase and evaluated in a native protein enzyme-linked immunosorbent assay (ELISA) with intact and heat-treated leptospiral cells, conjugated to fluorescein isothiocyanate (FITC) for indirect immunofluorescence with intact and methanol fixed cells and were used for LipL32 immunoprecipitation from leptospiral cells. rLipL32 MAbs conjugated to peroxidase or used as primary antibody bound to intact and heat-treated cells in ELISA, proving that they could be used in enzyme immunoassays for detection of the native protein. In immunofluorescence assay, MAbs labeled bacterial cells either intact or methanol fixed. Two MAbs were able to immunoprecipitate the native protein from live and motile leptospiral cells and, adsorbed onto magnetic beads, captured intact bacteria from artificially contaminated human sera for detection by polymerase chain reaction (PCR) amplification. Results of this study suggest that the MAbs produced can be useful for the development of diagnostic tests based on detection of LipL32 leptospiral antigen in biological fluids.

Diagnosis of gastric syphilis by direct immunofluorescence staining and real-time PCR testing

We report on a case of gastric syphilis in a patient with chronic dyspepsia. The diagnosis was established by serology and the demonstration of spirochetes in diffusely inflammed gastric mucosa by staining with a fluorescent monoclonal antibody specific for pathogenic treponemes and by the detection of specific treponemal DNA sequences by a real-time PCR.

Molecular subtyping of Treponema pallidum from North and South Carolina

Patients from five clinics in North and South Carolina who had lesions suggestive of primary or secondary syphilis were evaluated using molecular techniques that allow the differentiation of Treponema pallidum strains on the basis of two variable genes, tpr and arp. Lesion samples were screened for the presence of T. pallidum DNA using PCR for polA, which represents a segment of the polymerase I gene that is unique to the spirochete. Twenty-seven of 154 lesion samples were found to contain T. pallidum, 23 of which had typeable DNA. Seven molecular subtypes were found (10f, 12f, 13f, 14f, 14g, 15f, and 16f); one to four subtypes were identified at each clinic. Subtype 14f was found in 52% of the typeable specimens and was distributed in four of the five clinics. Subtype 16f was found in 22% of specimens and was concentrated at one clinic. Further data are needed to define the role of this technique in examining the epidemiology of syphilis.

The endemic treponematoses

Treponemal diseases comprise venereal syphilis (Treponema pallidum subsp. pallidum) and the endemic (non-venereal) treponematoses, i.e. yaws (T. pallidum subsp. pertenue), endemic syphilis (T. pallidum subsp. endemicum) and pinta (T. carateum). Treponemal diseases are distinguished on the basis of epidemiological characteristics and clinical manifestations. They are at present indistinguishable by morphological, immunological or serological methods. Several minor genetic differences have been identified among the subspecies. The endemic treponematoses have not yet been eliminated and are currently thought to affect at least 2.5 million persons. Renewed action towards the elimination of these diseases should be undertaken.

Syphilis: review with emphasis on clinical, epidemiologic, and some biologic features

Syphilis is a chronic disease with a waxing and waning course, the manifestations of which have been described for centuries. It occurs worldwide, and the incidence varies significantly with geographic location. Transmission is mainly by sexual contact. The causative organism, Treponema pallidum, was first described in 1905, but because of the inability to culture the organism and the limitations of direct microscopy, serologic testing is the mainstay of laboratory diagnosis. The disease has been arbitrarily divided into several stages. The primary stage is defined by a chancre at the site of inoculation. The secondary stage is characterized by a polymorphic rash, lymphadenopathy, and other systemic manifestations. A variable asymptomatic latent period follows, which for epidemiologic purposes is divided into early (<1 year) and late (>1 year) stages. The early stages (primary, secondary, and early latent) are potentially infectious. The tertiary stage is the most destructive and is marked by cardiovascular and neurologic sequelae and gummatous involvement of any organ system. Congenital infection may result in protean early or late manifestations. Unlike many other bacteria causing infectious diseases, the organism remains sensitive to penicillin, and this remains the mainstay of therapy.

Syphilis seroprevalence among pregnant women and its role as a risk factor for stillbirth in Maputo, Mozambique

OBJECTIVE

To elucidate the role of current syphilis as a risk factor for foetal death.

METHODS

Sera were obtained from 57 women with third trimester foetal death (cases) and 58 women with foetus alive (controls) matched for age and parity. All sera reactive in qualitative Rapid Plasma Reagin (RPR) analyses were tested with serial twofold dilutions to determine endpoint flocculation titres and tested with the micro-haemagglutination assay for Treponema pallidum (MHA-TP). Placental biopsies were sectioned and stained by haematoxylin-eosin and Warthin-Starry for light microscopy.

SETTING

Central Hospital, in Maputo, Mozambique, from January 1990 to June 1991.

RESULTS

The MHA-TP was reactive in 42% of cases and in 12% of controls (OR = 5.3; 95% CI: 1.9-15.4). The RPR card test was reactive at the dilution of 1.32 or greater in 28% of cases and in 7% of controls. All these results were confirmed by MHA-TP (OR = 5.3; 95% CI: 1.5-15.4). In 9/28 (32%) MHA-TP seroreactive women (7 cases and 2 controls) placental morphological changes indicated syphilitic infection.

CONCLUSION

MHA-TP seroreactivity and high titre RPR were associated with stillbirth. Morphological changes presumptive of syphilis infection were found in 32% placentas histologically studied. Syphilis is a risk factor for foetal death in Maputo, Mozambique.

Detection of infection or infectious agents by use of cytologic and histologic stains

A wide variety of stains are useful for detection of different organisms or, for viruses, the cytopathologic changes they induce, in smears prepared directly from clinical specimens and in tissue sections. Other types of stains, such as hematoxylin and eosin, are used routinely to stain tissue sections and are most valuable for assessing the immunologic response of the host to the invading pathogen. In many cases, the pattern of inflammation provides important clues to diagnosis and helps to guide the selection of additional "special" stains used predominantly for diagnosis of infectious diseases. A stain may be nonspecific, allowing detection of a spectrum of organisms, as do the Papanicolaou stain and silver impregnation methods, or detection of only a limited group of organisms, as do the different acid-fast techniques. Some nonspecific stains, such as the Gram stain, are differential and provide valuable preliminary information concerning identification. Immunohistochemical stains, on the other hand, are specific for a particular organism, although in some cases cross-reactions with other organisms occur. Despite the wealth of information that can be gleaned from a stained smear or section of tissue, however, the specific etiology of an infection often cannot be determined on the basis of only the morphology of the organisms seen; culture data are essential and must be considered in the final diagnosis.

Pathology of the umbilical cord in congenital syphilis: analysis of 25 specimens using histochemistry and immunofluorescent antibody to Treponema pallidum

Identification of Treponema pallidum in the placenta is important for diagnosis of congenital syphilis; however, spirochetes are difficult to observe in chorionic villi. To determine the sensitivity of umbilical cord examination for T pallidum, and the association of spirochetes with cord pathology, placentas were prospectively obtained from 25 women with untreated syphilis. The most common finding using hematoxylin-eosin staining was a normal-appearing umbilical cord (48%); necrotizing funisitis was the most frequent pathological lesion (36%). Spirochetes were detected using silver and immunofluorescent staining in 89% of cords, including 92% of histologically normal and 84% of abnormal cords. Three specimens showed subamnionic aggregates of spirochetes, consistent with amniotic fluid infection. Necrotizing funisitis was strongly associated with umbilical artery infection by spirochetes (P = .008). There was a 100% correlation between results of silver and immunofluorescent staining. The umbilical cord is a sensitive site for morphological confirmation of T pallidum; it is significant for the pathologist that spirochetes may often be detected in the absence of overt tissue inflammation or necrosis.

Laboratory diagnosis and interpretation of tests for syphilis

The lack of a method for demonstrating the presence of Treponema pallidum by growth necessitates the use of alternative methods. Traditionally, these methods are divided into direct detection methods (animal inoculation, dark-field microscopy, etc.) and serologic tests for the presence of patient antibody against T. pallidum. Serologic methods are further divided into two classes. One class, the nontreponemal tests, detects antibodies to lipoidal antigens present in either the host or T. pallidum; examples are the Venereal Disease Research Laboratory and rapid plasma reagin and tests. Reactivity in these tests generally indicates host tissue damage that may not be specific for syphilis. Because these tests are easy and inexpensive to perform, they are commonly used for screening, and with proper clinical signs they are suggestive of syphilis. The other class of test, the treponemal tests, uses specific treponemal antigens. Confirmation of infection requires a reactive treponemal test. Examples of the treponemal tests are the microhemagglutination assay for antibodies to T. pallidum and the fluorescent treponemal antibody absorption test. These tests are more expensive and complicated to perform than the nontreponemal tests. On the horizon are a number of direct antigen, enzyme-linked immunosorbent assay, and PCR techniques. Several of these techniques have shown promise in clinical trials for the diagnosis of congenital syphilis and neurosyphilis that are presently difficult to diagnose.

A case of secondary syphilis with mucous patches on the hard palate

A rare case of secondary syphilis showing mucous patches on the hard palate is reported. A 31-year-old male had two erosive patches which were slightly raised on his hard palate. A linear lesion was also present on the inside of his right alveolar process. Many red-brown macules on his abdomen and bilateral inguinal lymphadenopathy accompanied these symptoms. The serological tests for syphilis were positive: VDRL test 1:512, TPHA test 1:20,480, and IgM-FTA-ABS test 1:40. Immunohistochemical staining with rabbit monoclonal antibody to Treponema pallidum by the biotin-streptoavidin system detected treponemal organisms in the paraffin-embedded specimen from his mucous patch. A diagnosis of secondary syphilis was made, and he was given amoxicillin (AMPC) at 750 mg per day for 4 weeks. His eruptions, including the mucous patch, healed in a week.

Comparison of molecular and microscopic techniques for detection of Treponema pallidum in genital ulcers

We compared the ability of direct immunofluorescent staining (DFA) and the PCR to detect Treponema pallidum in specimens from patients with genital ulcer disease. Touch preparations from 156 patients with genital lesions were fixed in acetone and stained with a fluorescein-labeled monoclonal antibody specific for the 37-kDa antigen of T. pallidum. After microscopic examination, the smear was removed from the slide with a swab. DNA was extracted with phenol-chloroform and precipitated with isopropanol. Ten microliters of the extracted DNA was amplified by PCR using primers for the gene encoding the 47-kDa protein of T. pallidum and hybridized to an internal probe. Twenty-two of 156 specimens were positive for T. pallidum by DFA and PCR, while 127 were negative by both methods, yielding a concordance of 95.5% (kappa = 0.84). Four specimens were positive by PCR and negative by DFA, while three specimens were negative by PCR and positive by DFA. The DFA-negative, PCR-positive specimens may have resulted from the presence of large numbers of leukocytes on the slides, obscuring visualization of treponemes. The DFA-positive, PCR-negative results were not due to inhibition of the PCR since purified T. pallidum DNA was amplified when added to aliquots of these specimens. Negative results in these specimens were most likely due to inefficient recovery of their DNA. These data suggest that DFA and PCR are equivalent methods for detection of T. pallidum on touch preparations of genital lesions. Further refinements of the PCR assay are necessary for it to significantly improve the detection of T. pallidum in genital lesions.

New methodologies for the pathologic diagnosis of placental infections-immunohistochemistry, immunofluorescence, in situ nucleic acid hybridization and polymerase chain reaction

A variety of highly sensitive laboratory techniques is now available for the detection and localization of infectious agents in the placenta. This communication discusses, the role of immunohistochemistry, immunofluorescence, in situ nucleic acid hybridization, and polymerase chain reaction for infectious disease diagnosis in formalinfixed placental tissues. These techniques, as well as other sophisticated molecular methods currently in development, will greatly facilitate characterizing the role of infectious agents in a variety of perinatal and pediatric conditions, including birth defects, intrauterine growth retardation, and stillbirth.

Polypeptides of Treponema pallidum: progress toward understanding their structural, functional, and immunologic roles. Treponema Pallidum Polypeptide Research Group

Treponema pallidum subsp. pallidum, the spirochete that causes syphilis, is unusual in a number of respects, including its small genome size, inability to grow under standard in vitro culture conditions, microaerophilism, apparent paucity of outer membrane proteins, structurally complex periplasmic flagella, and ability to evade the host immune responses and cause disease over a period of years to decades. Many of these attributes are related ultimately to its protein content. Our knowledge of the activities, structure, and immunogenicity of its proteins has been expanded by the application of recombinant DNA, hybridoma, and structural fractionation techniques. The purpose of this monograph is to summarize and correlate this new information by using two-dimensional gel electrophoresis, monoclonal antibody reactivity, sequence data, and other properties as the bases of polypeptide identification. The protein profiles of the T. pallidum subspecies causing syphilis, yaws, and endemic syphilis are virtually indistinguishable but differ considerably from those of other treponemal species. Among the most abundant polypeptides are a group of lipoproteins of unknown function that appear to be important in the immune response during syphilitic infection. The periplasmic flagella of T. pallidum and other spirochetes are unique with regard to their protein content and ultrastructure, as well as their periplasmic location. They are composed of three core proteins (homologous to the other members of the eubacterial flagellin family) and a single, unrelated sheath protein; the functional significance of this arrangement is not understood at present. Although the bacterium contains the chaperonins GroEL and DnaK, these proteins are not under the control of the heat shock regulon as they are in most organisms. Studies of the immunogenicity of T. pallidum proteins indicate that many may be useful for immunodiagnosis and immunoprotection. Future goals in T. pallidum polypeptide research include continued elucidation of their structural locations and functional activities, identification and characterization of the low-abundance outer membrane proteins, further study of the immunoprotective and immunodiagnostic potential of T. pallidum proteins, and clarification of the roles of treponemal proteins in pathogenesis.