Last data update: Jun 03, 2024. (Total: 46935 publications since 2009)
Records 1-16 (of 16 Records) |
Query Trace: Smith SK [original query] |
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Rapid and sensitive point-of-care detection of Orthopoxviruses by ABICAP immunofiltration
Stern D , Olson VA , Smith SK , Pietraszczyk M , Miller L , Miethe P , Dorner BG , Nitsche A . Virol J 2016 13 (1) 207 BACKGROUND: The rapid and reliable detection of infectious agents is one of the most challenging tasks in scenarios lacking well-equipped laboratory infrastructure, like diagnostics in rural areas of developing countries. Commercially available point-of-care diagnostic tests for emerging and rare diseases are particularly scarce. RESULTS: In this work we present a point-of-care test for the detection of Orthopoxviruses (OPV). The OPV ABICAP assay detects down to 1 x 104 plaque forming units/mL of OPV particles within 45 min. It can be applied to clinical material like skin crusts and detects all zoonotic OPV infecting humans, including Vaccinia, Cowpox, Monkeypox, and most importantly Variola virus. CONCLUSIONS: Given the high sensitivity and the ease of handling, the novel assay could be highly useful for on-site diagnostics of suspected Monkeypox virus infections in areas lacking proper laboratory infrastructure as well as rapid on-site testing of suspected bioterrorism samples. |
A Multiplex PCR/LDR Assay for the Simultaneous Identification of Category A Infectious Pathogens: Agents of Viral Hemorrhagic Fever and Variola Virus.
Das S , Rundell MS , Mirza AH , Pingle MR , Shigyo K , Garrison AR , Paragas J , Smith SK , Olson VA , Larone DH , Spitzer ED , Barany F , Golightly LM . PLoS One 2015 10 (9) e0138484 CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF) syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR). The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus) as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively). The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus). |
Comparison of monkeypox virus clade kinetics and pathology within the prairie dog animal model using a serial sacrifice study design
Hutson CL , Carroll DS , Gallardo-Romero N , Drew C , Zaki SR , Nagy T , Hughes C , Olson VA , Sanders J , Patel N , Smith SK , Keckler MS , Karem K , Damon IK . Biomed Res Int 2015 2015 965710 Monkeypox virus (MPXV) infection of the prairie dog is valuable to studying systemic orthopoxvirus disease. To further characterize differences in MPXV clade pathogenesis, groups of prairie dogs were intranasally infected (8 x 103 p.f.u.) with Congo Basin (CB) or West African (WA) MPXV, and 28 tissues were harvested on days 2, 4, 6, 9, 12, 17, and 24 postinfection. Samples were evaluated for the presence of virus and gross and microscopic lesions. Virus was recovered from nasal mucosa, oropharyngeal lymph nodes, and spleen earlier in CB challenged animals (day 4) than WA challenged animals (day 6). For both groups, primary viremia (indicated by viral DNA) was seen on days 6-9 through day 17. CB MPXV spread more rapidly, accumulated to greater levels, and caused greater morbidity in animals compared to WA MPXV. Histopathology and immunohistochemistry (IHC) findings, however, were similar. Two animals that succumbed to disease demonstrated abundant viral antigen in all organs tested, except for brain. Dual-IHC staining of select liver and spleen sections showed that apoptotic cells (identified by TUNEL) tended to colocalize with poxvirus antigen. Interestingly splenocytes were labelled positive for apoptosis more often than hepatocytes in both MPXV groups. These findings allow for further characterization of differences between MPXV clade pathogenesis, including identifying sites that are important during early viral replication and cellular response to viral infection. |
In vitro efficacy of brincidofovir against variola virus
Olson VA , Smith SK , Foster S , Li Y , Lanier ER , Gates I , Trost LC , Damon IK . Antimicrob Agents Chemother 2014 58 (9) 5570-1 Brincidofovir (CMX001), a lipid conjugate of the acyclic nucleotide phosphonate cidofovir, is under development for smallpox treatment using "the Animal Rule," established by FDA in 2002. Brincidofovir reduces mortality caused by orthopoxvirus infection in animal models. Compared to cidofovir, brincidofovir has increased potency, oral administration, and no evidence of nephrotoxicity. Here we report the brincidofovir EC50 against five variola virus strains in vitro averaged 0.11 muM, nearly 100-fold more potent than cidofovir. |
Orthopoxvirus variola infection of Cynomys ludovicianus (North American Black tailed prairie dog)
Carroll DS , Olson VA , Smith SK , Braden ZH , Patel N , Abel J , Li Y , Damon IK , Karem KL . Virology 2013 443 (2) 358-62 Since the eradication of Smallpox, researchers have attempted to study Orthopoxvirus pathogenesis and immunity in animal models in order to correlate results human smallpox. A solely human pathogen, Orthopoxvirus variola fails to produce authentic smallpox illness in any other animal species tested to date. In 2003, an outbreak in the USA of Orthopoxvirus monkeypox, revealed the susceptibility of the North American black-tailed prairie dog (Cynomys ludovicianus) to infection and fulminate disease. Prairie dogs infected with Orthopoxvirus monkeypox present with a clinical scenario similar to ordinary smallpox, including prodrome, rash, and high mortality. This study examines if Black-tailed prairie dogs can become infected with O. variola and serve as a surrogate model for the study of human smallpox disease. Substantive evidence of infection is found in immunological seroconversion of animals to either intranasal or intradermal challenges with O. variola, but in the absence of overt illness. |
Phylogenetic and ecologic perspectives of a monkeypox outbreak, southern Sudan, 2005.
Nakazawa Y , Emerson GL , Carroll DS , Zhao H , Li Y , Reynolds MG , Karem KL , Olson VA , Lash RR , Davidson WB , Smith SK , Levine RS , Regnery RL , Sammons SA , Frace MA , Mutasim EM , Karsani ME , Muntasir MO , Babiker AA , Opoka L , Chowdhary V , Damon IK . Emerg Infect Dis 2013 19 (2) 237-45 Identification of human monkeypox cases during 2005 in southern Sudan (now South Sudan) raised several questions about the natural history of monkeypox virus (MPXV) in Africa. The outbreak area, characterized by seasonally dry riverine grasslands, is not identified as environmentally suitable for MPXV transmission. We examined possible origins of this outbreak by performing phylogenetic analysis of genome sequences of MPXV isolates from the outbreak in Sudan and from differing localities. We also compared the environmental suitability of study localities for monkeypox transmission. Phylogenetically, the viruses isolated from Sudan outbreak specimens belong to a clade identified in the Congo Basin. This finding, added to the political instability of the area during the time of the outbreak, supports the hypothesis of importation by infected animals or humans entering Sudan from the Congo Basin, and person-to-person transmission of virus, rather than transmission of indigenous virus from infected animals to humans. |
The pox in the North American backyard: Volepox virus pathogenesis in California mice (Peromyscus californicus)
Gallardo-Romero NF , Drew CP , Weiss SL , Metcalfe MG , Nakazawa YJ , Smith SK , Emerson GL , Hutson CL , Salzer JS , Bartlett JH , Olson VA , Clemmons CJ , Davidson WB , Zaki SR , Karem KL , Damon IK , Carroll DS . PLoS One 2012 7 (8) e43881 Volepox virus (VPXV) was first isolated in 1985 from a hind foot scab of an otherwise healthy California vole (Microtus californicus). Subsequent surveys in San Mateo County, CA, revealed serological evidence suggesting that VPXV is endemic to this area, and a second viral isolate from a Pinyon mouse (Peromyscus truei) was collected in 1988. Since then, few studies have been conducted regarding the ecology, pathology, and pathogenicity of VPXV, and its prevalence and role as a potential zoonotic agent remain unknown. To increase our understanding of VPXV disease progression, we challenged 24 California mice (Peromyscus californicus) intranasally with 1.6x10(3) PFU of purified VPXV. By day five post infection (pi) we observed decreased activity level, conjunctivitis, ruffled hair, skin lesions, facial edema, and crusty noses. A mortality rate of 54% was noted by day eight pi. In addition, internal organ necrosis and hemorrhages were observed during necropsy of deceased or euthanized animals. Viral loads in tissues (brain, gonad, kidney, liver, lung, spleen, submandibular lymph node, and adrenal gland), bodily secretions (saliva, and tears), and excretions (urine, and/or feces) were evaluated and compared using real time-PCR and tissue culture. Viral loads measured as high as 2x10(9) PFU/mL in some organs. Our results suggest that VPXV can cause extreme morbidity and mortality within rodent populations sympatric with the known VPXV reservoirs. |
Progressive vaccinia: case description and laboratory-guided therapy with vaccinia immune globulin, ST-246 and CMX001
Lederman ER , Davidson W , Groff HL , Smith SK , Warkentien T , Li Y , Wilkins KA , Karem KL , Akondy RS , Ahmed R , Frace M , Shieh WJ , Zaki S , Hruby DE , Painter WP , Bergman KL , Cohen JI , Damon IK . J Infect Dis 2012 206 (9) 1372-85 Progressive vaccinia (PV) is a rare but potentially lethal complication which develops in smallpox vaccine recipients with severely impaired cellular immunity. We report a patient with PV requiring treatment with vaccinia immune globulin and who received two investigational agents, ST-246 and CMX001. We describe the various molecular, pharmacokinetic, and immunologic studies which provided guidance to escalate and then successfully discontinue therapy. Despite development of resistance to ST-246 during treatment, the patient had resolution of his PV. This case demonstrates the need for continued development of novel anti-orthopoxvirus pharmaceuticals and the importance of both intensive and timely clinical and laboratory support in management of PV. |
Analysis of variola and vaccinia neutralization assays for smallpox vaccines
Hughes CM , Newman FK , Davidson WB , Olson VA , Smith SK , Holman RC , Yan L , Frey SE , Belshe RB , Karem KL , Damon IK . Clin Vaccine Immunol 2012 19 (7) 1116-8 Possible smallpox re-emergence drives research for third-generation vaccines that effectively neutralize variola virus. Comparison of neutralization assays using different substrates, variola and vaccinia (Dryvax and MVA), showed significantly different 90% neutralization titers; Dryvax underestimated while MVA overestimated variola neutralization. Third-generation vaccines may rely upon neutralization as a correlate of protection. |
Investigation of the first laboratory-acquired human cowpox virus infection in the United States.
McCollum AM , Austin C , Nawrocki J , Howland J , Pryde J , Vaid A , Holmes D , Weil MR , Li Y , Wilkins K , Zhao H , Smith SK , Karem K , Reynolds MG , Damon IK . J Infect Dis 2012 206 (1) 63-8 BACKGROUND: Cowpox virus is an Orthopoxvirus that can cause infections in humans and a variety of animals. Infections occur in Eurasia; human nor animal infection has been reported in the United States. This report describes the occurrence of the first known human case of laboratory-acquired cowpox virus infection in the United States and ensuing investigation. METHODS: The patient and laboratory personnel were interviewed, and laboratory activities were reviewed. Real-time PCR and serologic assays were used to test the patient's specimens. PCR assays were used to test specimens obtained during the investigation. RESULTS: The patient's lesion tested positive for cowpox virus DNA. Genome sequencing revealed a recombinant region consistent with a strain of cowpox virus stored in the research laboratory's freezer. Cowpox virus contamination was detected in six additional laboratory stocks of viruses. Orthopoxvirus DNA was present in three of twenty environmental swabs taken from laboratory surfaces. CONCLUSIONS: The handling of contaminated reagents or contact with contaminated surfaces was likely the mode of transmission. Delays in recognition and diagnosis of this infection in a laboratory researcher underscore the importance of a thorough patient history--including occupational information--and laboratory testing to facilitate a prompt investigation and application of control and remediation measures. |
Effective antiviral treatment of systemic orthopoxvirus disease: ST-246 treatment of prairie dogs infected with monkeypox
Smith SK , Self J , Weiss S , Carroll D , Braden Z , Regnery RL , Davidson W , Jordan R , Hruby DE , Damon IK . J Virol 2011 85 (17) 9176-87 Smallpox preparedness research has led to development of antiviral therapies for treatment of serious orthopoxvirus infections. Monkeypox virus is an emerging, zoonotic orthopoxvirus which can cause severe and transmissible disease in humans generating concerns for public health. Monkeypox infection results in a systemic, febrile-rash illness closely resembling smallpox. Currently, there are no small-molecule antiviral therapeutics approved to treat orthopoxvirus infections of humans. The prairie dog, using monkeypox virus as a challenge virus, has provided a valuable non-human animal model in which monkeypox infection closely resembles human systemic orthopoxvirus illness. Here, we assess the efficacy of the anti-orthopoxvirus compound ST-246 in prairie dogs against 65 X LD(50) challenge with monkeypox virus. Animals were infected intranasally and administered ST-246 for 14 days, beginning on days 0, 3, or post rash onset. Swab and blood samples were collected every 2 days and analyzed for presence of viral DNA by real-time PCR and viable virus by tissue culture. Seventy-five percent of infected animals that received vehicle alone succumbed to infection. One hundred percent of animals that received ST-246 survived challenge, and animals that received treatment before symptom onset remained largely asymptomatic. Viable virus and viral DNA were undetected or at greatly reduced levels in animals that began treatment on 0 or 3 days post infection, as compared to control animals or animals treated post rash onset. Animals treated after rash onset manifest illness but all recovered. Our results indicate ST-246 can be used therapeutically, following onset of rash illness, to treat systemic orthopoxvirus infections. |
Establishment of the black-tailed prairie dog (Cynomys ludovicianus) as a novel animal model for comparing smallpox vaccines administered pre-exposure in both high and low-dose monkeypox challenges
Keckler MS , Carroll DS , Gallardo-Romero NF , Lash RR , Salzer JS , Weiss SL , Patel N , Clemmons CJ , Smith SK , Hutson CL , Karem KL , Damon IK . J Virol 2011 85 (15) 7683-98 The 2003 Monkeypox virus (MPXV) outbreak and subsequent laboratory studies demonstrated that the black-tailed prairie dog was susceptible to MPXV infection and that the ensuing rash illness was similar to human systemic orthopoxvirus (OPXV) infections - including a 7 to 9-day incubation period and likely, in some cases, a respiratory route of infection - which distinguishes this model from others. The need for safe and efficacious vaccines for both endemic and epidemic OPVX disease is important to protect an increasingly OPXV naive population. In this study, we tested current and investigational smallpox vaccines for safety, induction of anti-OPXV antibodies, and protection against mortality and morbidity in two MPXV challenges. None of the smallpox vaccines caused illness in this model and all vaccinated animals showed anti-OPXV antibody responses and neutralizing antibody. We tested vaccine efficacy by challenging the animals with 10(5) or 10(6) pfu Congo Basin MPXV 30 days post vaccination and evaluating morbidity and mortality. Our results demonstrate that vaccination with either Dryvax(R) or Acambis2000(R) protected the animals from death with no rash illness. Vaccination with IMVAMUNE(R) also protected the animals from death, albeit with (modified) rash illness. Based on the results of this study, we believe prairie dogs offer a novel and potentially useful small animal model for the safety and efficacy testing of smallpox vaccines in pre- and post-exposure vaccine testing, which is important for public health planning. |
Vaccinia virus infections in martial arts gym, Maryland, USA, 2008
Hughes CM , Blythe D , Li Y , Reddy R , Jordan C , Edwards C , Adams C , Conners H , Rasa C , Wilby S , Russell J , Russo KS , Somsel P , Wiedbrauk DL , Dougherty C , Allen C , Frace M , Emerson G , Olson VA , Smith SK , Braden Z , Abel J , Davidson W , Reynolds M , Damon IK . Emerg Infect Dis 2011 17 (4) 730-3 Vaccinia virus is an orthopoxvirus used in the live vaccine against smallpox. Vaccinia virus infections can be transmissible and can cause severe complications in those with weakened immune systems. We report on a cluster of 4 cases of vaccinia virus infection in Maryland, USA, likely acquired at a martial arts gym. |
Variola and monkeypox utilize conserved mechanisms of virion motility and release that depend on Abl- and Src-family tyrosine kinases
Reeves PM , Smith SK , Olson VA , Thorne SH , Bornmann W , Damon IK , Kalman D . J Virol 2010 85 (1) 21-31 Vaccinia virus (VacV) enters mammalian cells, replicates extranuclearly, and produces virions that move to the cell surface along microtubules, fuse with the plasma membrane, and move from infected cells towards apposing cells on actin-filled membranous protrusions or actin tails. To form actin tails, cell-associated enveloped virions (CEV) require Abl- and Src-family tyrosine kinases. Further, release of CEV from the cell requires Abl- but not Src-family tyrosine kinases, and is blocked by imatinib mesylate (STI-571; Gleevec), an Abl-family kinase inhibitor used to treat chronic myelogenous leukemia in humans. Here we demonstrate that the Poxviridae family members Monkeypox (MPX) and Variola (VarV) used conserved mechanisms for actin motility and EEV release. Furthermore, we show that imatinib mesylate is effective in a mouse model of infection with VacV, whether delivered prophylactically or post-infection, and restricts spread of virions from the site of innoculation. While inhibitors of both Src- and Abl-family kinases, such as dasatinib (BMS-354825, Sprycel), are effective in limiting dissemination VacV, VarV, and MPX in vitro, members of this class of drugs appear to have immunosuppressive effects in vivo that preclude their use as anti-infectives. Together, these data suggest a possible utility for imatinib mesylate in treating smallpox or MPX infections, or complications associated with vaccination. |
Dosage comparison of Congo Basin and West African strains of monkeypox virus using a prairie dog animal model of systemic orthopoxvirus disease
Hutson CL , Carroll DS , Self J , Weiss S , Hughes CM , Braden Z , Olson VA , Smith SK , Karem KL , Regnery RL , Damon IK . Virology 2010 402 (1) 72-82 The prairie dog is valuable for the study of monkeypox virus (MPXV) virulence and closely resembles human systemic orthopoxvirus disease. Herein, we utilize a variable dose intranasal challenge with approximately 10(3), 10(4), 10(5), and 10(6)PFU for each clade to further characterize virulence differences between the two MPXV clades. A trend of increased morbidity and mortality as well as greater viral shedding was observed with increasing viral challenge dose. Additionally, there appeared to be a delay in onset of disease for animals challenged with lower dosages of virus. Mathematical calculations were used to determine LD(50) values and based on these calculations, Congo Basin MPXV had approximately a hundred times lower LD(50) value than the West African clade (5.9x10(3) and 1.29x10(5) respectively); reinforcing previous findings that Congo Basin MPXV is more virulent. |
Evaluation of smallpox vaccines using variola neutralization
Damon IK , Davidson WB , Hughes CM , Olson VA , Smith SK , Holman RC , Frey SE , Newman F , Belshe RB , Yan L , Karem K . J Gen Virol 2009 90 1962-6 The search for a 'third'-generation smallpox vaccine has resulted in the development and characterization of several vaccine candidates. A significant barrier to acceptance is the absence of challenge models showing induction of correlates of protective immunity against variola virus. In this light, virus neutralization provides one of few experimental methods to show specific 'in vitro' activity of vaccines against variola virus. Here, we provide characterization of the ability of a modified vaccinia virus Ankara vaccine to induce variola virus-neutralizing antibodies, and we provide comparison with the neutralization elicited by standard Dryvax vaccination. |
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