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Tallmadge, R. L.

Publications and source records attributed to Tallmadge, R. L..

3 recordsLinked to original sources

TICKHUNTER: A Targeted Hybridization-Capture Sequencing Approach for the Detection and Characterization of Tick-borne Pathogens and Blood Meals

As weather systems quickly change, vector communities and their pathogens evolve faster than assay panels can be redesigned. Additionally, PCRs narrow target range makes it structurally unable to catch divergent or reassorted agents. We developed a hybrid capture next-generation sequencing enrichment platform that provides comprehensive detection and characterization of tick-borne agents alongside ecological vertebrate host identification with low-pass sequencing. Analytical validation demonstrated performance comparable to qPCR with superior variant tolerance and multiplexing capacity. Field deployment in subtropical, metropolitan New York detected Anaplasma phagocytophilum strains (n=3) linked to human granulocytic anaplasmosis and a Babesia microti-like species in urban raccoon (Procyon lotor) populations. Tick vector screening revealed a putatively novel chimeric Flavi-like virus in invasive Haemaphysalis longicornis ticks combining segmented and unsegmented genomic features, with codon adaptation analysis indicating strong human compatibility. Serology revealed high Flavivirus seropositivity in NYC raccoons, suggesting an unrecognized urban reservoir role. Blood meal analysis simultaneously revealed complex ecological pathogen transmission networks spanning multiple vertebrate hosts. This integrated surveillance system enables comprehensive pathogen discovery, real-time evolutionary monitoring, and ecological risk assessment, transforming our capacity to detect emerging tick-borne threats in rapidly changing environments and prevent spillovers.

microbiology↗

A multiplex real-time PCR assay for detection of equine herpesvirus 1 and equine herpesvirus 4

Equine herpesvirus (EHV) 1 and EHV-4 are common viral pathogens of horses that can cause upper respiratory disease, neurological disease, abortion, or death. As characteristic alphaherpesviruses, both EHV-1 and EHV-4 can establish latency, resulting in a lifelong carrier state in infected animals. Here we describe the development and validation of a rapid and sensitive multiplex real-time PCR assay (EHV1-4MP) that simultaneously detects EHV-1 and EHV-4 and includes an endogenous internal control targeting the equid genome. The EHV1-4MP assay analytical sensitivity was determined to be 15 genome copies for EHV-1, EHV-4, and equid MC1R per reaction. Analytical specificity was determined using a panel of 28 equine respiratory pathogens and commensal equine microorganisms. The EHV1-4MP assay detected reference and clinical isolates of EHV-1 and EHV-4, and did not detect other equine herpesviruses such as EHV-2, EHV-3, EHV-5, or several other viral and bacterial pathogens of horses. Importantly, the EHV1-4MP assay developed here has improved specificity compared to existing assays and is able to exclude the closely related EHV-3, EHV-8, and -9 viruses. Diagnostic performance was evaluated using 60 clinical samples including upper respiratory swabs and washes, blood, placenta, lung, and brain. The EHV1-4MP assay results were in 100% concordance with singleplex EHV-1 and EHV-4 assays. Our results demonstrate that the EHV1-4MP real-time assay developed here offers rapid, sensitive, and simultaneous detection of EHV-1 and EHV-4. ImportanceEquine herpesvirus (EHV) 1 and -4 are highly contagious and ubiquitous pathogens that commonly cause fever and respiratory disease, and can lead to outbreaks, abortion, neurological disease, or death. Here we describe the development and validation of a rapid and sensitive multiplex real-time PCR assay (EHV1-4MP) that simultaneously detects EHV-1 and EHV-4 as well as an endogenous equid control and an exogenous DNA control, with improved specificity compared to existing assays.

microbiology↗

Isolation of Actinomyces cricetomyis sp. nov from orocervicofacial abscesses of African giant pouched rats (Cricetomys ansorgei)

African giant pouched rats are of interest for their unique sense of smell and can be trained for a variety of applications including detection of explosives and infectious diseases. A colony housed at a university animal care facility developed abscesses associated with the jaw and eye in multiple animals. The predominant bacterial species in each case was a catalase-positive Actinomyces-like Gram-positive bacillus. The isolates from different sites and animals matched each other genetically but had sequences and biochemical profiles inconsistent with previously described species of this group. Based on whole genome sequence, biochemical characterization, and fatty acid profile, a novel species of the genus Actinomyces is proposed, namely Actinomyces cricetomyis (type strain 186855T). The type strain is deposited at ATCC (TSD-310) and BCCM/LMG (LMG 32803).

microbiology↗