Time filter

Source Type

New Milford, CT, United States

Accurate genotyping of a human papilloma virus (HPV) isolated from clinical specimens depends on molecular identification of the unique and exclusive nucleotide base sequence in the hypervariable region of a highly conserved segment of the HPV L1 gene. Among other options, a heminested (nested) polymerase chain reaction (PCR) technology using two consecutive PCR replications of the target DNA in tandem with three consensus general primers may be used to detect a minute quantity of HPV DNA in crude proteinase K digestate of cervicovaginal cells, and to prepare the template for genotyping by automated direct DNA sequencing. A short target sequence of 40-60 bases excised from the computer-generated electropherogram is sufficient for BLAST determination of all clinically relevant HPV genotypes, based on the database stored in the GenBank. This chapter discusses the principle and the essential technical elements in performing nested PCR DNA amplification for the detection of HPV from clinical specimens and short target sequence genotyping for HPV, using standard molecular biology laboratory equipment and commercially available reagents. © 2012 Springer Science+Business Media New York. Source

Lee S.H.,Milford Hospital | Vigliotti J.S.,Milford Hospital | Vigliotti V.S.,Milford Hospital | Jones W.,Milford Hospital | And 2 more authors.
International Journal of Molecular Sciences | Year: 2014

A highly conserved 357-bp segment of the 16S ribosomal RNA gene (16S rDNA) of Borrelia burgdorferi sensu lato and the correspondent 358-bp segment of the Borrelia miyamotoi gene were amplified by a single pair of nested polymerase chain reaction (PCR) primers for detection, and the amplicons were used as the templates for direct Sanger DNA sequencing. Reliable molecular diagnosis of these borreliae was confirmed by sequence alignment analysis of the hypervariable regions of the PCR amplicon, using the Basic Local Alignment Search Tool (BLAST) provided by the GenBank. This methodology can detect and confirm B. burgdorferi and B. miyamotoi in blood samples of patients with off-season spirochetemia of low bacterial density. We found four B. miyamotoi infections among 14 patients with spirochetemia, including one patient co-infected by both B. miyamotoi and B. burgdorferi in a winter month when human exposure to tick bites is very limited in the Northeast of the U.S.A. We conclude that sensitive and reliable tests for these two Borrelia species should be implemented in the microbiology laboratory of hospitals located in the disease-endemic areas, for timely diagnosis and appropriate treatment of the patients at an early stage of the infection to prevent potential tissue damages. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source

Lee S.H.,Milford Hospital | Vigliotti V.S.,Milford Hospital | Pappu S.,Milford Hospital
Journal of Clinical Pathology | Year: 2010

Aims: Persistent infection indicated by detection of human papillomavirus 16 (HPV-16) on repeat testing over a period of time poses the greatest cervical cancer risk. However, variants of HPV-16, HPV-31 and HPV-33 may share several short sequence homologies in the hypervariable L1 gene commonly targeted for HPV genotyping. The purpose of this study was to introduce a robust laboratory procedure to validate HPV-16 detected in clinical specimens, using the GenBank sequence database as the standard reference for genotyping. Methods: A nested PCR with two pairs of consensus primers was used to amplify the HPV DNA released in crude proteinase K digest of the cervicovaginal cells in liquid-based Papanicolaou cytology specimens. The positive nested PCR products were used for direct automated DNA sequencing. Results: A 48-base sequence downstream of the GP5+ priming site, or a 34-base sequence upstream thereof, was needed for unequivocal validation of an HPV-16 isolate. Selection of a 45-base, or shorter, sequence immediately downstream of the GP5+ site for Basic Local Alignment Search Tool sequence analysis invariably led to ambiguous genotyping results. Conclusions: DNA sequence analysis may be used for differential genotyping of HPV-16, HPV-31 and HPV-33 in clinical specimens. However, selection of the signature sequence for Basic Local Alignment Search Tool algorithms is crucial to distinguish certain HPV-16 variants from other closely related HPV genotypes. Source

Lee S.H.,Milford Hospital | Vigliotti J.S.,Milford Hospital | Vigliotti V.S.,Milford Hospital | Jones W.,Milford Hospital | Shearer D.M.,Therapeutic Research Foundation
International Journal of Molecular Sciences | Year: 2014

The diagnoses of Lyme disease based on clinical manifestations, serological findings and detection of infectious agents often contradict each other. We tested 52 blind-coded serum samples, including 20 pre-treatment and 12 post-treatment sera from clinically suspect Lyme disease patients, for the presence of residual Lyme disease infectious agents, using nested PCR amplification of a signature segment of the borrelial 16S ribosomal RNA gene for detection and direct DNA sequencing of the PCR amplicon for molecular validation. These archived sera were split from the samples drawn for the 2-tier serology tests performed by a CDC-approved laboratory, and are used as reference materials for evaluating new diagnostic reagents. Of the 12 post-treatment serum samples, we found DNA evidence of a novel borrelia of uncertain significance in one, which was also positive for the 2-tier serology test. The rest of the post-treatment sera and all 20 control sera were PCR-negative. Of the 20 pre-treatment sera from clinically suspect early Lyme disease patients, we found Borrelia miyamotoi in one which was 2-tier serology-negative, and a Borrelia burgdorferi in two-one negative and one positive for 2-tier serology. We conclude that a sensitive and reliable DNA-based test is needed to support the diagnosis of Lyme disease and Lyme disease-like borreliosis. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source

Lee S.H.,Milford Hospital | Vigliotti J.S.,Milford Hospital | Vigliotti V.S.,Milford Hospital | Jones W.,Milford Hospital
Cancers | Year: 2014

The newly gained knowledge of the viral etiology in cervical carcinogenesis has prompted industrial interests in developing virology-based tools for cervical cancer prevention. Due to the long incubation period from viral infection to developing an invasive cancer, a process whose outcome is influenced by numerous life-style and genetic factors, the true efficacy of the genotype-specific human papillomavirus (HPV) vaccines in cervical cancer prevention cannot be determined for another 30 years. Most HPV DNA test kits designed to replace the traditional Papanicolaou (Pap) smears for precancer detection lack the analytical sensitivity and specificity to comprehensively detect all potentially carcinogenic HPVs and to perform reliable genotyping. The authors implemented the classic nested PCR and Sanger DNA-sequencing technology for routine HPV testing. The results showed a true negative HPV PCR invariably indicates the absence of precancerous cells in the cytology samples. However, 80.5% of single positive HPV-16 tests and 97.3% of single positive HPV-18 tests were associated with a negative or a largely self-reversible Pap cytology. Routine sensitive and reliable HPV type-specific or perhaps even variant-specific methods are needed to address the issues of persistence of HPV infection if a virology-based primary cervical screen is used to replace the Pap cytology screening paradigm. © 2014 by the authors; licensee MDPI, Basel, Switzerland. Source

Discover hidden collaborations