Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-4 (of 4 Records) |
Query Trace: Robinson LK[original query] |
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Genetic typing of isolates of Rickettsia typhi.
Kato CY , Chung IH , Robinson LK , Eremeeva ME , Dasch GA . PLoS Negl Trop Dis 2022 16 (5) e0010354 ![]() ![]() Murine typhus, which is caused by Rickettsia typhi, has a wide range of clinical manifestations. It has a low mortality rate but may result in meningoencephalitis and interstitial pneumonia in severe cases. Comparisons of complete genome sequences of R. typhi isolates from North Carolina, USA (Wilmington), Myanmar (B9991PP), and Thailand (TH1527) identified only 26 single nucleotide polymorphism (SNP) and 7 insertion-deletion (INDEL) sites in these highly syntenic genomes. Assays were developed to further define the distribution of these variant sites among 15 additional isolates of R. typhi with different histories from Asia, the USA, and Africa. Mismatch amplification mutation assays (MAMA) were validated for 22 SNP sites, while the 7 INDEL sites were analyzed directly on agarose gels. Six SNP types, 9 INDEL types, 11 total types were identified among these 18 isolates. Replicate DNA samples as well as comparisons of isolates with different passage and source histories gave consistent genetic typing profiles. Comparison of the SNP and INDEL markers to R. typhi's nearest neighbor Rickettsia prowazekii demonstrated that the majority of the SNPs represent intra-species variation that arose post divergence of these two species while several INDEL sites also exhibited intraspecies variability among the R. prowazekii genomes that have been completely sequenced. The assays for the presence of these SNP and INDEL sites, particularly the latter, comprise a low technology gel method for consistently distinguishing R. typhi and R. prowazekii as well as for differentiating genetic types of R. typhi. |
Analytically sensitive Rickettsia species detection for laboratory diagnosis
Chung IH , Robinson LK , Stewart-Juba JJ , Dasch GA , Kato CY . Am J Trop Med Hyg 2022 106 (5) 1352-7 Clinical and laboratory diagnosis of rickettsial diseases is challenging because of the undifferentiated symptoms (commonly fever, headache, and malaise) and low bacteremia (< 100 genomic copies [gc]/mL) during the early acute stage of illness. Early treatment with doxycycline is critical for a positive outcome, especially in Rickettsia rickettsii (Rocky Mountain spotted fever) infections where cases may be fatal within 5 to 10 days from symptom onset, emphasizing the need for more sensitive diagnostics. A real-time reverse transcriptase polymerase chain reaction (PCR) assay, RCKr, was developed and validated for Rickettsia spp. nucleic acid detection in human clinical samples. The limit of detection for RCKr was determined to be 20 gc/mL, compared with our 2013 (Kato etal.) laboratory developed test, PanR8 at 1,800 to 2,000 gc/mL. Inclusivity, exclusivity, accuracy, and precision results correlated as expected. From an evaluation of 49 banked clinical samples, RCKr detected 35 previously positive samples, as well as two specimens that were PanR8 real-time PCR negative yet clinically diagnosed as possible rickettsiosis. Ct values from RCKr clinical sample testing show a 100-fold increase relative to PanR8. Additional testing is needed to understand the clinical sensitivity of RCKr; however, this study demonstrates RCKr to have high analytical specificity and sensitivity for Rickettsia detection. |
Methods for surveillance of fetal alcohol syndrome: the Fetal Alcohol Syndrome Surveillance Network II (FASSNetII) - Arizona, Colorado, New York, 2009 - 2014
O'Leary LA , Ortiz L , Montgomery A , Fox DJ , Cunniff C , Ruttenber M , Breen A , Pettygrove S , Klumb D , Druschel C , Frias JL , Robinson LK , Bertrand J , Ferrara K , Kelly M , Gilboa SM , Meaney FJ . Birth Defects Res A Clin Mol Teratol 2015 103 (3) 196-202 Surveillance of fetal alcohol syndrome (FAS) is important for monitoring the effects of prenatal alcohol exposure and describing the public health burden of this preventable disorder. Building on the infrastructure of the Fetal Alcohol Syndrome Surveillance Network (FASSNet, 1997-2002), in 2009 the Centers for Disease Control and Prevention awarded 5-year cooperative agreements to three states, Arizona, Colorado, and New York, to conduct population-based surveillance of FAS. The Fetal Alcohol Syndrome Surveillance Network II (FASSNetII, 2009-2014) developed a surveillance case definition based on three clinical criteria: characteristic facial features, central nervous system abnormalities, and growth deficiency. FASSNetII modified the FASSNet methods in three important ways: (1) estimation of a period prevalence rather than birth prevalence; (2) surveillance of FAS among school-age children (ages 7-9 years) to better document the central nervous system abnormalities that are not apparent at birth or during infancy; and (3) implementation of an expert clinical review of abstracted data for probable and confirmed cases classified through a computerized algorithm. FASSNetII abstracted data from multiple sources including birth records, medical records from child development centers or other specialty clinics, and administrative databases such as hospital discharge and Medicaid. One challenge of FASSNetII was its limited access to non-medical records. The FAS prevalence that could be estimated was that of the population identified through an encounter with the healthcare system. Clinical and public health programs that identify children affected by FAS provide critical information for targeting preventive, medical and educational services in this vulnerable population. |
Assessment of real-time PCR assay for detection of Rickettsia spp. and Rickettsia rickettsii in banked clinical samples.
Kato CY , Chung IH , Robinson LK , Austin AL , Dasch GA , Massung RF . J Clin Microbiol 2012 51 (1) 314-7 ![]() Two novel real-time PCR assays were developed for the detection of Rickettsia spp. One assay detects all tested Rickettsia spp.; the other is specific for Rickettsia rickettsii. Evaluation using DNA from human blood and tissue samples showed both assays to be more sensitive than nested PCR assays currently in use at the CDC. |
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