HARTFORD, Conn.--(BUSINESS WIRE)--During the winter month of February 2014, Sin Hang Lee, M.D., of Milford Molecular Diagnostics laboratory in Milford, Conn., detected an unusual strain of Borrelia burgdorferi with two homeologous 16S rRNA genes by DNA sequencing in the blood of a boy discharged from a psychiatric hospital. This is the second novel strain of borrelia detected in a patient’s blood samples by Dr. Lee, as reported in an April 21, 2016 article in International Medical Case Reports Journal (https://www.dovepress.com/article_26575.t53729944).
As reported, a teenager living in Massachusetts was initially diagnosed with Lyme disease and treated with a full 28-day course of antibiotics. However, he subsequently developed a variety of peculiar symptoms, the severity of which prevented him from attending school for a year. A Lyme disease consultant, called in to review the case, found the serology test results non-diagnostic of Lyme disease. Based on the consultant’s opinion, the patient was then hospitalized for pure psychiatric disorders at a psychiatric hospital for seven weeks. After discharge from the psychiatric hospital, a venous blood sample taken from the boy by his primary care physician was tested positive for Borrelia burgdorferi by 16S rRNA gene sequencing. The patient was then referred to a major general medical center in Boston for treatment. Further analysis of the sequencing data revealed that the Borrelia burgdorferi detected in this case has two partially homologous (homeologous) 16S rRNA genes, a hitherto unrecognized gene organization in Lyme disease spirochetes.
In a separate instance, occurring approximately two years ago, Dr. Lee reported uncovering another novel strain of borrelia through DNA sequencing in an archived serum sample from a patient from another state. The patient had been treated for neurologic Lyme disease, also by 16S rRNA gene sequencing http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3975398/.
Each bacterial species has its unique 16S rRNA gene needed for initiating protein synthesis and for life maintenance. Researchers using pure bacterial cultures as the study materials in the past showed that all spirochete isolates from Lyme disease patients in North America belong to the species of Borrelia burgdorferi sensu stricto and all have only one copy of 16S rRNA gene. The commercial serology test kits for Lyme disease are designed for the diagnosis of infections caused by this one species of Lyme disease spirochetes. However, other uncultivatable borrelial strains with different genetic makeups can also cause Lyme disease but with atypical serology patterns which are considered non-diagnostic by the criteria promulgated by these diagnostic test kits, as Dr. Lee explained in this case report.
In the current report, Dr. Lee said, “Using a pair of genus-specific PCR primers to perform same-nested PCR for amplification of the borrelial 16S rRNA gene, followed by direct Sanger sequencing of the PCR amplicon, can detect and validate a wide range of Borrelia species, including novel Borrelia strains causing Lyme and related borrelioses. Direct DNA sequencing should be implemented in hospital laboratories in Lyme disease-endemic areas for early reliable diagnosis of this infectious disease and for further studies of the diversity of the causative agents of Lyme borreliosis.”
“People living in or visiting Lyme disease endemic areas should be aware of possible infections by not yet recognized borrelial strains which cannot be diagnosed by the standard test kits,” said Dr. Lee.
Dr. Lee, who has been practicing pathology in New Haven County Connecticut since 1971, is the director of Milford Molecular Diagnostics laboratory in Milford, Connecticut (http://www.dnalymetest.com/). He has been using DNA sequencing for molecular diagnosis of Lyme and related borrelioses since 2009 when he was a pathologist at Milford Hospital.