Publications by authors named "Nagaraja Thirumalapura"
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been reported in multiple animal species besides humans. The goal of this study was to report clinical signs, infection progression, virus detection and antibody response in a group of wild felids housed in adjacent but neighboring areas at the Pittsburgh Zoo. Initially, five African lions () housed together exhibited respiratory clinical signs with viral shedding in their feces in March of 2021 coinciding with infection of an animal keeper.
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- An obligate intracellular bacterium is responsible for Potomac horse fever (PHF), and diagnosis involves detecting antibodies, isolating the bacterium, or using a PCR assay to find its DNA.
- A new duplex real-time PCR assay was developed by adding primers and probes, targeting two gene locations to enhance detection for diagnosing PHF in horses.
- The modified assay, tested on samples from 56 horses, showed reliable detection without cross-reacting with common horse pathogens, but some fecal samples yielded false positives when only tested for one of the detected gene targets.
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- The study aimed to determine how common Anaplasma phagocytophilum and Borrelia burgdorferi infections are in horses across Pennsylvania, involving 271 horses suspected of tick-borne infections.
- Results showed that 7% of horses tested positive for A phagocytophilum using PCR, while B burgdorferi was undetected in any horse blood samples.
- Serology testing revealed that 44.3% of horses had antibodies for A phagocytophilum, and 77.1% had antibodies for B burgdorferi, indicating both diseases are prevalent in the region, with variations in detection between testing methods.
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- - A 5-day-old Boer goat in Pennsylvania died from infection and septicemia, showing significant hemorrhage during an autopsy, particularly around the urachus and urinary bladder.
- - Microscopic analysis revealed the presence of a specific bacterium in various tissues, confirmed through advanced identification methods like MALDI-TOF mass spectrometry and PCR testing.
- - An investigation revealed a 70% mortality rate among goats in the 2019 kidding season, pinpointing a breach in biosecurity as the likely source of the zoonotic bacteria, which was spread through the farm's poultry.
Background And Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), besides causing human infection, has been shown to naturally infect several susceptible animal species including large cats (tigers, lions, pumas, spotted leopards), dogs, cats, ferrets, gorillas and minks. Cats and minks are continuing to be the most reported species with SARS-CoV-2 infections among animals but it needs to be investigated further.
Methods And Results: We report the detection of SARS-CoV-2 from a domestic cat that exhibited respiratory disease after being exposed to SARS-CoV-2 virus from humans in the same household.
Metagenomic sequencing of clinical diagnostic specimens has a potential for unbiased detection of infectious agents, diagnosis of polymicrobial infections and discovery of emerging pathogens. Herein, next generation sequencing (NGS)-based metagenomic approach was used to investigate the cause of illness in a subset of horses recruited for a tick-borne disease surveillance study during 2017-2019. Blood samples collected from 10 horses with suspected tick-borne infection and five apparently healthy horses were subjected to metagenomic analysis.
View Article and Find Full Text PDFsubspecies , a zoonotic bacterial pathogen caused a series of outbreaks with high mortality affecting swine herds in multiple locations of the USA and Canada in 2019. Further genetic analysis revealed that this agent clustered with ATCC 35246, a strain associated with high mortality outbreaks in swine herds of China originally reported in 1977. Rapid and accurate diagnosis is absolutely critical for controlling and limiting further spread of this emerging disease of swine.
View Article and Find Full Text PDFWhole-genome sequencing (WGS) has changed our understanding of bacterial pathogens, aiding outbreak investigations and advancing our knowledge of their genetic features. However, there has been limited use of genomics to understand antimicrobial resistance of veterinary pathogens, which would help identify emerging resistance mechanisms and track their spread. The objectives of this study were to evaluate the correlation between resistance genotypes and phenotypes for Staphylococcus pseudintermedius, a major pathogen of companion animals, by comparing broth microdilution antimicrobial susceptibility testing and WGS.
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- * PCR testing is being used more in labs for detecting MAP in feces, proving to be fast and reliable compared to traditional fecal cultures, although extracting DNA from fecal samples can be tricky.
- * A study tested a specific nucleic acid extraction method combined with a gene PCR and found it accurately identified all test samples for both positive and negative results, demonstrating its effectiveness for diagnosing MAP in cattle.
Draft genome sequences of two outbreak isolates of subsp. from a Pennsylvania swine herd affected with high mortality and morbidity are reported here. The genome analysis revealed that the isolates are closely related to a virulent strain originally identified in China.
View Article and Find Full Text PDF, the black-legged tick, harbors multiple organisms and transmits several pathogens to animals and humans. To determine the presence of tick-borne microorganisms carried by in Pennsylvania, 299 adult ticks were collected from across the state and tested with a multiplex bead panel targeting 20 microorganisms. The Luminex bead-based xMAP MultiFLEX Mega Tick Panel detected microorganisms in these ticks, including spp.
View Article and Find Full Text PDFNeospora caninum is an apicomplexan protozoan parasite that is a leading cause of abortion in cattle. Detection of parasite-specific DNA by PCR is a highly sensitive method for identifying the presence of N. caninum in a variety of tissues.
View Article and Find Full Text PDFBackground: Antimicrobial resistance (AMR) of bacterial pathogens is an emerging public health threat. This threat extends to pets as it also compromises our ability to treat their infections. Surveillance programs in the United States have traditionally focused on collecting data from food animals, foods, and people.
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- - The study assessed three different DNA extraction methods to confirm the presence of Mycobacterium avium subspecies paratuberculosis in bovine feces samples.
- - The DNA Extract All Reagents Kit™ showed the highest efficiency, successfully extracting amplifiable DNA from 96.29% of known positive samples.
- - In contrast, the other methods, Chelex-100 resin and polyethylene glycol, had significantly lower success rates at 25.92% and 0%, respectively.
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- * Organism identification was confirmed using MALDI-TOF mass spectrometry, which indicated the isolates as Brucella species.
- * Further analysis including phenotypic and genotypic characteristics confirmed the isolates as B. canis, and their mass spectral profiles were added to a reference library for easier future identification.
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- Diverse pathogens, like Ehrlichiae, thrive in host endosomes and can cause long-lasting infections, transmitted mainly by ticks.
- In the study, CD4(+) T cells were examined in relation to Ehrlichia muris infection in mice, revealing that IL-10 levels influenced T cell effectiveness and bacterial clearance.
- Blocking IL-10 during early infection stages improved CD4(+) T cell responses, highlighting the importance of understanding CD4(+) T cell development for better immune protection against persistent infections.
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- Researchers developed a mouse model for studying ehrlichiosis using the human pathogen Ehrlichia muris-like agent (EMLA) to better understand this tick-borne disease.* -
- Three strains of mice were infected with EMLA via different methods, revealing that infection severity varied based on the route and dose, with effects similar to human infections.* -
- The new EMLA mouse model shows promise for investigating disease mechanisms, immune responses, and transmission of ehrlichiosis.*
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- The complete genome sequence of Ehrlichia muris strain AS145(T) was obtained, which was isolated from a wild mouse in Japan in 1983.
- *E. muris is known to create lasting infections in laboratory mice.
- *It serves as a model pathogen for studying ehrlichiosis in mice.
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- Ehrlichioses are tick-borne bacterial diseases with no available vaccines, caused by intracellular bacteria from the Ehrlichia genus; various immunoreactive proteins play a role in the immune response.
- In a study, the protein E. muris P29 was evaluated as a subunit vaccine in mice and showed significant protection against challenge infections, contrasting with other Ehrlichia proteins that contained tandem repeats.
- The successful immunization with E. muris P29 led to strong antibody responses, particularly IgG, highlighting the role of CD4+ T cells in targeting the protein during infection, while persistent infection impaired the IgG antibody response.
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- * This study focused on designing peptides from two Ehrlichia proteins, P28-19 and Hsp60, which showed potential for use in diagnosing ehrlichiosis and provided protection in vaccinated mice.
- * The findings highlight the effectiveness of structural vaccinology as a promising strategy for developing vaccines against dangerous pathogens like Ehrlichia.
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- The bacterium Ehrlichia chaffeensis causes human monocytotropic ehrlichiosis (HME), a serious tick-borne disease in the U.S.
- Current strategies for combating HME focus on the immune response, specifically activating CD4(+) and CD8(+) T cells, but there are no available vaccines.
- A study using proteins from a related bacterium, Ehrlichia muris, found that specific outer membrane proteins can generate long-term immune responses and reduce bacterial loads in vaccinated mice, highlighting the potential for new vaccine development.
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- Human monocytotropic ehrlichiosis, caused by the bacterium Ehrlichia chaffeensis, leads to fatal disease characterized by CD8(+) T cell damage and an imbalance in immune responses with excessive cytokine production.
- In a study involving mice, it was found that lethal infections caused a reduction in NKT cell numbers and an increase in activated NK cells in the liver, correlating with liver damage.
- Depletion of NK cells resulted in less liver injury, reduced inflammation markers, and improved bacterial clearance, suggesting that NK cells contribute to harmful immune responses that hinder effective anti-ehrlichial actions.
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- Human monocytotropic ehrlichiosis (HME) is a serious tick-borne disease caused by the bacterium Ehrlichia chaffeensis, which can be modeled in mice using Ehrlichia muris and Ixodes ovatus Ehrlichia (IOE).
- Researchers found that persistent E. muris infection helps mice develop immune memory that protects against subsequent IOE infections, while a sublethal dose of IOE does not offer the same protection.
- The study showed that untreated mice with persistent E. muris infections had more memory T cells and regulatory T cells, indicating that ongoing infections enhance the immune response, while those treated with doxycycline were more susceptible to later infections with IOE.
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- * Mice primed with the non-virulent E. muris developed strong immune responses, resulting in 100% protection against subsequent lethal infections with virulent strains.
- * In contrast, mice initially primed with virulent strains showed severe immune responses leading to tissue damage and fatal outcomes, underscoring the importance of a strong T cell response for effective immunity.