Morgan Q. S. Wendling

Preliminary microRNA analysis in lung tissue to identify potential therapeutic targets against H5N1 infection.

Within the past decade, human infections with the highly pathogenic avian influenza H5N1 have resulted in approximately 60% mortality and increased the need for vaccines and therapeutics. Understanding the molecular events associated with pathology can aid this effort; therefore, this study was conducted to assess microRNA (miRNA) expression in mouse lungs infected with H5N1 A/Vietnam/1203/04. Intranasal administration of 1500 median tissue culture infectious dose of H5N1 promoted differences in the number and expression pattern of miRNA from lung tissue collected at 2, 4, 6, 24, and 96 h post-exposure that mapped to common biological functions. Informatics analysis identified miRNA-specific predicted genes known to be therapeutic drug targets in which Furin was common to all time periods. This study provides insight into the differential miRNA expression with respect to the host-pathogen relationship and identification of potential therapeutic drug targets.

Inactivation of vegetative bacterial threat agents on environmental surfaces.

Following a wide-area biological terror attack, numerous decontamination technologies, techniques, and strategies will be required for rapid remediation. Establishing an understanding of how disinfectants will perform under field conditions is of critical importance. The purpose of this study was to determine the efficacy of several liquid decontaminants, when used to inactivate vegetative biological agents on environmental surfaces. Aluminum, carpet, concrete, glass, and wood coupons were inoculated with 1×10(8) CFU of Burkholderia mallei, Francisella tularensis, Vibrio cholerae, or Yersinia pestis. Using spray-based application methods, decontamination was then attempted with pH-adjusted bleach, 1% citric acid, 70% ethanol, quaternary ammonia, or Pine-Sol®. Results indicated that decontamination efficacy varied significantly by decontaminant and organism. Materials such as wood are difficult to decontaminate, even when using sporicides. The data presented here will help responders develop efficacious remediation strategies following a large-scale contamination incident.

The effects of environmental conditions on persistence and inactivation of Brucella suis on building material surfaces.

Aims:  The purpose of this study was to evaluate the effects of environmental conditions and material type on persistence and inactivation of Brucella suis.

MicroRNA expression in mice infected with seasonal H1N1, swine H1N1 or highly pathogenic H5N1.

Influenza virus infections in humans remain a healthcare concern, and the need for vaccines, therapeutics and prophylactics remains a high priority. Understanding the molecular events associated with influenza-virus-induced pathology may lead to the identification of clinical disease biomarkers and novel antiviral targets. MicroRNAs (miRNAs) are well-conserved endogenous non-coding RNAs known to regulate post-transcriptional gene expression as well as play a major role in many biological processes and pathways. Animal studies have demonstrated that miRNAs are involved in viral disease and controlling inflammation. In this study, we examined the differences in the miRNA expression profiles associated with the lung in mice infected with influenza viruses that varied in virulence and pathogenicity. A statistical model was employed that utilized changes in miRNA expression to identify the virus that was used to infect the mice. This study identified a unique fingerprint of viral pathogenicity associated with seasonal H1N1, swine H1N1 and highly pathogenic H5N1 in the mouse model, and may lead to the identification of novel therapeutic and prophylactic targets.

An assessment of transcriptional changes in porcine skin exposed to bromine vapor

Bromine is an industrial chemical that can cause severe cutaneous burns. This study was a preliminary investigation into the effect of cutaneous exposure to bromine vapor using a weanling swine burn model and microarray analysis. Ventral abdominal sites were exposed to a mean calculated bromine vapor concentration of 0.69 g L−1 for 10 or 20 min. At 48 h postexposure, total RNA from skin samples was isolated, processed, and hybridized to Affymetrix GeneChip Porcine Genome Arrays. Expression analysis revealed that bromine vapor exposure for 10 or 20 min promoted similar transcriptional changes in the number of significantly modulated probe sets. A minimum of 83% of the probe sets was similar for both exposure times. Ingenuity pathways analysis revealed eight common biological functions among the top 10 functions of each experimental group, in which 30 genes were commonly shared among 19 significantly altered signaling pathways. Transcripts encoding heme oxygenase 1, interleukin‐1β, interleukin 2 receptor gamma chain, and plasminogen activator inhibitor‐1 were identified as common potential therapeutic targets for Phase II/III clinical trial or FDA‐approved drugs. The present study is an initial assessment of the transcriptional responses to cutaneous bromine vapor exposure identifying molecular networks and genes that could serve as targets for developing therapeutics for bromine‐induced skin injury.

Inactivation of Brucella Suis, Burkholderia pseudomallei, Francisella tularensis, and Yersinia pestis using Vaporous Hydrogen Peroxide

This study evaluated the inactivation of Brucella suis, Burkholderia pseudomallei, Francisella tularensis, and Yersinia pestis on glass, Hypalon® rubber glove, and stainless steel using vaporous hydrogen peroxide fumigation of a ∼15 m3 chamber. A suspension of approximately 1 × 108 colony forming units (CFU) of each organism was dried on coupons of each type of test surface and exposed to vaporous hydrogen peroxide. A significant reduction in the log10 CFU of each organism on all test materials was observed between the controls evaluated after a 1-hour drying time and unexposed controls evaluated after decontamination. For all organisms, qualitative growth assessments showed that vaporous hydrogen peroxide exposure completely inactivated bacterial viability on all replicates of the test materials incubated up to 7 days post-exposure. In parallel, all Geobacillus stearothermophilus biological indicators (BI) exposed to vaporous hydrogen peroxide exhibited no growth after 1 and 7 days incubation. This study provides information on using a combination of quantitative and qualitative growth assessments to evaluate vaporous hydrogen peroxide for the surface decontamination of B. suis, B. pseudomallei, F. tularensis, and Y. pestis within a large-scale chamber.

Environmental persistence of vaccinia virus on materials.

Smallpox is caused by the variola virus, and ranks as one of the most serious diseases that could originate from a biological weapon. However, limited data exist on the persistence of variola and related viruses on materials (that may act as fomites), under controlled environmental conditions. To fill these data gaps, we determined the persistence of the vaccinia virus (an established surrogate for the variola virus) as a function of temperature, relative humidity and material. Experiments were conducted with vaccinia virus in a freeze‐dried form, using four materials under four sets of environmental conditions. After elapsed times ranging from 1 to 56 days, the virus was extracted from small coupons and quantified via plaque‐forming units (PFU). The vaccinia virus was most persistent at low temperature and low relative humidity, with greater than 104 PFU recovered from glass, galvanized steel and painted cinder block at 56 days (equivalent to only a c. 2 log reduction). Thus, vaccinia virus may persist from weeks to months, depending on the material and environmental conditions. This study may aid those responsible for infection control to make informed decisions regarding the need for environmental decontamination following the release of an agent such as variola.

A Novel Approach for Conducting Room-scale Vaporous Hydrogen Peroxide Decontamination of Virulent Bacillus Anthracis Spores

Studies have been conducted to determine the efficacy of various decontamination technologies against virulent B. anthracis and surrogate spores within small, bench-scale chambers. This study assessed an approach for evaluating room-scale (∼2,700 ft3) decontamination efficacy of vaporous hydrogen peroxide fumigation against B. anthracis Ames and B. subtilis spores deposited onto porous and non-porous indoor surface materials. Approximately 1times108 colony-forming units (CFU) of B. anthracis and B. subtilis spores were dried onto galvanized metal and ceiling tile coupons and then exposed to vaporous hydrogen peroxide. The materials contaminated with B. anthracis spores were placed inside a Class III biosafety cabinet (BSC III) that circulated vaporous hydrogen peroxide from within the decontaminated room, into and out of the BSC III. Identical materials inoculated in the same manner and at the same density with B. subtilis were placed both inside and outside of the BSC III to compare decontamination efficacy. Three fumigations were conducted using two sets of cycle parameters. The first set of cycle parameters for vaporous hydrogen peroxide exposure (10 minutes of conditioning at 12 g/min; 75 minutes of decontamination at 11 g/min) yielded log reductions in viable B. anthracis and B. subtilis spores ranging from 6.1 to 7.0 on all materials, while only 76% of the commercial biological indicators (1times106 CFU) evaluated in parallel were completely inactivated. The second set of cycle parameters (12 minutes of conditioning at 12 g/min; 104 minutes of decontamination at 8 g/min) yielded log reductions in viable B. anthracis and B. subtilis spores ranging from 6.7 to 7.4 on all materials and complete inactivation of biological indicators. These results demonstrate this method as a viable approach to assess room-scale fumigant decontamination efficacy against B. anthracis Ames spores.

Inactivation of Burkholderia pseudomallei on environmental surfaces using spray-applied, common liquid disinfectants.

Five commercially available liquid antimicrobials were evaluated for their ability to decontaminate common environmental surface materials, contaminated with Burkholderia pseudomallei, using a spray‐based disinfectant delivery procedure. Tests were conducted at both an ambient temperature (c. 20°C) and a lower temperature (c. 12°C) condition. Nonporous materials (glass and aluminium) were more easily decontaminated than porous materials (wood, concrete and carpet). Citric acid (1%) demonstrated poor efficacy in all test conditions. Bleach (pH‐adjusted), ethanol (70%), quaternary ammonium and PineSol®, demonstrated high (>6 log10 reduction) efficacies on glass and aluminium at both temperatures, but achieved varying results for wood, carpet and concrete. Temperature had minimal effect on decontamination efficacy during these tests.

Temporal effects in porcine skin following bromine vapor exposure.

Bromine is an industrial chemical that causes severe cutaneous burns. When selecting or developing effective treatments for bromine burns, it is important to understand the molecular mechanisms of tissue damage and wound healing. This study investigated the effect of cutaneous bromine vapor exposure on gene expression using a weanling swine burn model by microarray analysis. Ventral abdominal sites were exposed to a mean calculated bromine vapor concentration of 0.51 g/L for 7 or 17 min. At 6 h, 48 h, and 7 days post-exposure, total RNA from skin samples was isolated, processed, and analyzed with Affymetrix GeneChip® Porcine Genome Arrays (N = 3 per experimental group). Differences in gene expression were observed with respect to exposure duration and sampling time. Ingenuity Pathways Analysis (IPA) revealed four common biological functions (cancer, cellular movement, cell-to-cell signaling and interaction, and tissue development) among the top ten functions of each experimental group, while canonical pathway analysis revealed 9 genes (ARG2, CCR1, HMOX1, ATF2, IL-8, TIMP1, ESR1, HSPAIL, and SELE) that were commonly shared among four significantly altered signaling pathways. Among these, the transcripts encoding HMOX1 and ESR1 were identified using IPA as common potential therapeutic targets for Phase II/III clinical trial or FDA-approved drugs. The present study describes the transcriptional responses to cutaneous bromine vapor exposure identifying molecular networks and genes that could serve as targets for developing therapeutics for bromine-induced skin injury.