ABSTRACT
Rabies is a fatal zoonotic disease that requires fast, accurate diagnosis to prevent disease in an exposed individual. The current gold standard for post-mortem diagnosis of human and animal rabies is the direct fluorescent antibody (DFA) test. While the DFA test has proven sensitive and reliable, it requires high quality antibody conjugates, a skilled technician, a fluorescence microscope and diagnostic specimen of sufficient quality. The LN34 pan-lyssavirus real-time RT-PCR assay represents a strong candidate for rabies post-mortem diagnostics due to its ability to detect RNA across the diverse Lyssavirus genus, its high sensitivity, its potential for use with deteriorated tissues, and its simple, easy to implement design. Here, we present data from a multi-site evaluation of the LN34 assay in 14 laboratories. A total of 2,978 samples (1,049 DFA positive) from Africa, the Americas, Asia, Europe, and the Middle East were tested. The LN34 assay exhibited low variability in repeatability and reproducibility studies and was capable of detecting viral RNA in fresh, frozen, archived, deteriorated and formalin-fixed brain tissue. The LN34 assay displayed high diagnostic specificity (99.68%) and sensitivity (99.90%) when compared to the DFA test, and no DFA positive samples were negative by the LN34 assay. The LN34 assay produced definitive findings for 80 samples that were inconclusive or untestable by DFA; 29 were positive. Five samples were inconclusive by the LN34 assay, and only one sample was inconclusive by both tests. Furthermore, use of the LN34 assay led to the identification of one false negative and 11 false positive DFA results. Together, these results demonstrate the reliability and robustness of the LN34 assay and support a role for the LN34 assay in improving rabies diagnostics and surveillance.
Subject(s)
Lyssavirus/genetics , RNA, Viral/genetics , Rabies , Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Animals , Diagnosis , Humans , Rabies/diagnosis , Rabies/geneticsABSTRACT
Although vector-borne diseases are specific to the region of the host, there is a necessity for surveillance or reference laboratories to perform standardized, high-throughput testing capable of meeting the needs of a changing military environment and response efforts. The development of standardized, high-throughput, semiquantitative real-time and reverse transcription real-time polymerase chain reaction (PCR) methods allows for the timely dissemination of data to interested parties while providing a platform in which long-term sample storage is possible for the testing of new pathogens of interest using a historical perspective. PCR testing allows for the analysis of multiple pathogens from the same sample, thus reducing the workload of entomologists in the field and increasing the ability to determine if a pathogen has spread beyond traditionally defined locations. US Army Public Health Command Region-Europe (USAPHCR-Europe) Laboratory Sciences (LS) has standardized tests for 9 pathogens at multiple life stages. All tests are currently under international accreditation standards. Using these PCR methods and laboratory model, which have universal Department of Defense application, the USAPHCR-Europe LS will generate quality data that is scientifically sound and legally defensible to support force health protection for the US military in both deployed and garrison environments.
Subject(s)
Arthropod Vectors , Bacterial Infections/diagnosis , Environmental Monitoring/standards , Polymerase Chain Reaction/methods , Protozoan Infections/diagnosis , Virus Diseases/diagnosis , Animals , Arthropod Vectors/microbiology , Arthropod Vectors/parasitology , Arthropod Vectors/virology , Bacterial Infections/transmission , Environmental Monitoring/methods , Humans , Laboratories/standards , Military Personnel , Protozoan Infections/transmission , Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Specimen Handling/methods , Transition Temperature , United States , United States Department of Defense , Virus Diseases/transmission , Viruses/isolation & purificationABSTRACT
In the course of our search for new bioactive compounds from basidiomycetes, four new compounds were isolated from fermentations of Limacella illinita. Illinitone A (1) exhibited weak phytotoxic and moderate nematicidal activities against Caenorhabditis elegans, illinitone B (2) was moderately cytotoxic, while limacellone (3) exhibited weak cytotoxic and phytotoxic activities. The muurolane sesquiterpene 4a was found to be inactive in the assays performed here. Limacellone (3), which appeared to be related with the illinitones 1 and 2, has a new C15 carbon skeleton. It is possible that compounds 1, 2 and 3 are terpenoids/ secoterpenoids, but their biosyntheses were not investigated.
