Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sensitive and specific PCR method to detect Treponema pallidum in clinical specimens was developed. PCR primers were designed based on two unique features of the DNA polymerase I gene (polA). The first distinctive characteristic is that the region codes for a high cysteine content and has low homology with similar regions of DNA polymerase I gene from known microorganisms. The second unique feature is the presence of four insertions in the gene. PCR tests using primers designed on the basis these regions reacted with various pathogenic T. pallidum subspecies but did not react with nonpathogenic treponemal species or other spirochetes. An additional 59 species of bacteria and viruses, including those that cause genital ulcers, tested negative. This PCR method is extremely robust and sensitive. The detection limit is about 10 to 25 organisms when analyzed on gel. However, the analytic sensitivity can be increased by at least 1 log, to a detection limit of a single organism, when the ABI 310 Prism Genetic Analyzer is used to detect fluorescence-labeled amplicons. We further used this test in a clinical setting and compared the results with results from a previously reported multiplex-PCR test (for T. pallidum, Haemophilus ducreyi, and herpes simplex virus). We tested 112 genital ulcer specimens by the polA PCR, obtaining a sensitivity of 95.8% and a specificity of 95.7%. These results suggest that the polA PCR is applicable as a routine clinical diagnostic test for syphilis.
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PMID:New tests for syphilis: rational design of a PCR method for detection of Treponema pallidum in clinical specimens using unique regions of the DNA polymerase I gene. 1132 18

A molecular-based subtyping system for Treponema pallidum was used during an investigation of increasing syphilis in Maricopa County, Arizona. Genital ulcer or whole blood specimens from patients with syphilis were assayed by a polymerase chain reaction (PCR) amplification of a T. pallidum DNA polymerase I gene. Positive specimens were typed on the basis of PCR amplification of 2 variable genes. In all, 41 (93%) of 44 of ulcer specimens and 4 (27%) of 15 blood specimens yielded typeable T. pallidum DNA. Twenty-four (53%) of 45 specimens were subtype 14f; other subtypes identified included 4f, 4i, 5f, 12a, 12f, 14a, 14d, 14e, and 14i. Only 2 specimens were from epidemiologically linked patients. This investigation demonstrates that multiple subtypes of T. pallidum can be found in an area with high syphilis morbidity, although 1 subtype (14f) was predominant. Four typeable specimens were from blood, a newly identified specimen source for subtyping.
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PMID:Molecular subtyping of Treponema pallidum in an Arizona County with increasing syphilis morbidity: use of specimens from ulcers and blood. 1134 8

Previous reports suggest that Treponema pallidum bacteremia occurs in persons with syphilis exposure ('incubating syphilis') and in persons with primary or secondary syphilis. During a recent syphilis outbreak, whole blood samples from 32 persons with suspected syphilis or syphilis exposure were screened using polymerase chain reaction (PCR) to amplify the DNA polymerase I gene (polA) of T. pallidum. Of the 32 samples, polA was amplified from 13 (41%). Of these 13, three were determined to have incubating syphilis; two had primary or secondary syphilis and eight had latent syphilis. This study demonstrates that spirochetemia can occur throughout the course of T. pallidum infection.
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PMID:Amplification of the DNA polymerase I gene of Treponema pallidum from whole blood of persons with syphilis. 1157 88

Acute human immunodeficiency virus (HIV) seroconversion illness is a difficult diagnosis to make because of its nonspecific and protean manifestations. We present such a case in an adolescent. A 15-year-old boy presented with a 5-day history of fever, sore throat, vomiting, and diarrhea. The patient also reported a nonproductive cough, coryza, and fatigue. The patient's only risk factor for HIV infection was a history of unprotected intercourse with 5 girls. Physical examination was significant for fever, exudative tonsillopharyngitis, shotty cervical lymphadenopathy, and palpable purpura on both feet. Laboratory studies demonstrated lymphopenia and mild thrombocytopenia. Hemoglobin, serum creatinine, and urinalysis were normal. The following day, the patient remained febrile. Physical examination revealed oral ulcerations, conjunctivitis, and erythematous papules on the thorax; the purpura was unchanged. Serologies for hepatitis B, syphilis, HIV, and Epstein-Barr virus were negative. Bacterial cultures of blood and stool and viral cultures of throat and conjunctiva showed no pathogens. Coagulation profile and liver enzymes were normal. Within 1 week, all symptoms had resolved. The platelet count normalized. Repeat HIV serology was positive, as was HIV DNA polymerase chain reaction. Subsequent HIV viral load was 350 000, and the CD4 lymphocyte count was 351/mm3. HIV is the seventh leading cause of death among people aged 15 to 24 in the United States, and up to half of all new infections occur in adolescents. Our patient presented with many of the typical signs and symptoms of acute HIV infection: fever, fatigue, rash, pharyngitis, lymphadenopathy, oral ulcers, emesis, and diarrhea. Other symptoms commonly reported include headache, myalgias, arthralgias, aseptic meningitis, peripheral neuropathy, thrush, weight loss, night sweats, and genital ulcers. Common seroconversion laboratory findings include leukopenia, thrombocytopenia, and elevated transaminases. The suspicion of acute HIV illness should prompt virologic and serologic analysis. Initial serology is usually negative. Diagnosis therefore depends on direct detection of the virus, by assay of viral load (HIV RNA), DNA polymerase chain reaction, or p24 antigen. Both false-positive and false-negative results for these tests have been reported, further complicating early diagnosis. Pediatricians should play an active role in identifying HIV-infected patients. Our case, the first report of acute HIV illness in an adolescent, emphasizes that clinicians should consider acute HIV seroconversion in the appropriate setting. Recognition of acute HIV syndrome is especially important for improving prognosis and limiting transmission. It is imperative that we maintain a high index of suspicion as primary care physicians for adolescents who present with a viral syndrome and appropriate risk factors.
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PMID:Acute human immunodeficiency virus syndrome in an adolescent. 1452 19

Venereal syphilis is a multi-stage, sexually transmitted disease caused by the spirochetal bacterium Treponema pallidum (Tp). Herein we describe a cohort of 57 patients (age 18-68 years) with secondary syphilis (SS) identified through a network of public sector primary health care providers in Cali, Colombia. To be eligible for participation, study subjects were required to have cutaneous lesions consistent with SS, a reactive Rapid Plasma Reagin test (RPR-titer > or = 1 : 4), and a confirmatory treponemal test (Fluorescent Treponemal Antibody Absorption test- FTA-ABS). Most subjects enrolled were women (64.9%), predominantly Afro-Colombian (38.6%) or mestizo (56.1%), and all were of low socio-economic status. Three (5.3%) subjects were newly diagnosed with HIV infection at study entry. The duration of signs and symptoms in most patients (53.6%) was less than 30 days; however, some patients reported being symptomatic for several months (range 5-240 days). The typical palmar and plantar exanthem of SS was the most common dermal manifestation (63%), followed by diffuse hypo- or hyperpigmented macules and papules on the trunk, abdomen and extremities. Three patients had patchy alopecia. Whole blood (WB) samples and punch biopsy material from a subset of SS patients were assayed for the presence of Tp DNA polymerase I gene (polA) target by real-time qualitative and quantitative PCR methods. Twelve (46%) of the 26 WB samples studied had quantifiable Tp DNA (ranging between 194.9 and 1954.2 Tp polA copies/ml blood) and seven (64%) were positive when WB DNA was extracted within 24 hours of collection. Tp DNA was also present in 8/12 (66%) skin biopsies available for testing. Strain typing analysis was attempted in all skin and WB samples with detectable Tp DNA. Using arp repeat size analysis and tpr RFLP patterns four different strain types were identified (14d, 16d, 13d and 22a). None of the WB samples had sufficient DNA for typing. The clinical and microbiologic observations presented herein, together with recent Cali syphilis seroprevalence data, provide additional evidence that venereal syphilis is highly endemic in this region of Colombia, thus underscoring the need for health care providers in the region to be acutely aware of the clinical manifestations of SS. This study also provides, for the first time, quantitative evidence that a significant proportion of untreated SS patients have substantial numbers of circulating spirochetes. How Tp is able to persist in the blood and skin of SS patients, despite the known presence of circulating treponemal opsonizing antibodies and the robust pro-inflammatory cellular immune responses characteristic of this stage of the disease, is not fully understood and requires further study.
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PMID:Secondary syphilis in cali, Colombia: new concepts in disease pathogenesis. 2050 22