Evaluation of two methods for detection of viable Bacillus anthracis simulant spores in maritime environmental samples

Analytical methods exist to detect biothreat agents in environmental samples during a response to biological contamination incidents. However, the coastal zone facilities and assets of the US Coast Guard (USCG), including response boats in diverse geographical areas and maritime environmental conditions, can pose complex and unique challenges for adapting existing analytical detection methods. The traditional culture (TC) and the rapid viability polymerase chain reaction (RV-PCR) methods were evaluated for their compatibility for maritime environmental surface and grab sample analysis to detect spores of Bacillus thuringiensis subspecies kurstaki (Btk), a surrogate for Bacillus anthracis. The representative samples collected from a USCG installation included surfaces, such as aluminum on boats, nonskid tread on decks of watercraft, computer touchscreens, and concrete piers, and grab samples of boat washdown water, soil, vegetation, and gravel from surrounding areas. Replicate samples were spiked with Btk spores at two to three tenfold increasing levels and analyzed. Out of a total of 150 samples collected and analyzed, the TC method gave 10 false-positive and 19 false-negative results, while the RV-PCR method-based analysis resulted in 0 false-positive and 26 false-negative results. An abundance of microbial background and particulates in some samples interfered with true results, while both methods gave similar results for samples with low microbial background and particulates. Improved and high-throughput sample processing methods are needed for analysis of complex environmental samples.

Industrialization and food safety for the Tsleil-Waututh Nation: An analysis of chemical levels in shellfish in Burrard Inlet

While Indigenous food systems remain critical for community well-being, traditionally harvested foods are a potential source of toxic exposures. The Tsleil-Waututh Nation (TWN) is seeking to restore shellfish harvesting in Burrard Inlet (British Columbia [BC], Canada), where the cumulative effects of industrial activity have nearly eliminated safe harvesting. The Trans Mountain Expansion project would triple the capacity to transport oil through the inlet, threatening TWN's progress to restore shellfish harvesting. To inform ongoing efforts we assessed contamination by heavy metals (arsenic, cadmium, lead, and mercury) and 48 polycyclic aromatic hydrocarbons (PAHs) congeners in different shellfish species (Softshell clams, Varnish clams, and Dungeness crab) in three areas. We compared our results against local screening values (SVs) established by the TWN and BC Ministry of Environment and Climate Change Strategy, as well as provincial and national benchmarks. In total, we analyzed 18 composite samples of Softshell clams and Varnish clams (5 individuals per sample), as well as 17 individual crabs. We found chemical contamination in all species at all sites. PAHs were most frequently detected in Softshell clams, highest in the site closest to the pipeline terminus. Clams presented higher levels of contamination than crabs for PAHs, but not for heavy metals. For Softshell and Varnish clams, all heavy metals across study sites exceeded at least one of the population-specific SVs. Of the 14 PAHs detected, benzo(a)pyrene presented a median concentration in Softshell clams of 3.25 μ/kg, exceeding local SV for subsistence fisher. Our results call for further assessment of human health impacts related to food harvesting within Burrard Inlet and establishing a long-term coordinated program co-led by the TWN to monitor contamination and inform future harvesting programs. The study draws attention to the need to consider locally-relevant toxicity benchmarks, and include potential health impacts of food contamination in appraising development project proposals.

Comparison of surface sampling methods for an extended duration outdoor biological contamination study

Bacillus anthracis, the causative agent for anthrax, is a dangerous pathogen to humans and has a history as a bioterrorism agent. While sampling methods have been developed and evaluated for characterizing and clearing contaminated indoor sites, the performance of these sampling methods is unknown for use in outdoor environments. This paper presents surface sampling data for Bacillus atrophaeus spores, a surrogate for B. anthracis, from a 210-day outdoor study that evaluated the detection and recovery of spores using five different sampling methods as follows: sponge sticks, 37-mm vacuum filter cassettes, residential wet vacuums, robotic floor cleaners, and grab samples of soil, leaves, and grass. The spores were applied by spraying a liquid suspension onto the surfaces. Both asphalt and concrete surfaces were sampled by all the surface sampling methods, excluding grab sampling. Stainless steel coupons placed outdoors were additionally sampled using sponge sticks. Sampling methods differed in their ability to collect detectable spores over the duration of the study. The 37-mm vacuums and sponge sticks consistently detected spores on asphalt through day 37 and robots through day 99. The wet vacuums detected spores on asphalt for days 1 and 4, but not again until day 210. On concrete, all samplers detected spores until day 210 except for sponge stick samplers that detected spores only up until the day 99 time point. For all sampling methods, spore recoveries were higher from concrete than from asphalt surfaces. There was no statistically significant difference in recoveries of sponge sticks and 37-mm vacuums from either asphalt or concrete surfaces. Processing of grab samples was challenging due to non-target background microorganisms resulting in high detection limits for the samples.

Considerations for estimating microbial environmental data concentrations collected from a field setting

In the event of an indoor release of an environmentally persistent microbial pathogen such as Bacillus anthracis, the potential for human exposure will be considered when remedial decisions are made. Microbial site characterization and clearance sampling data collected in the field might be used to estimate exposure. However, there are many challenges associated with estimating environmental concentrations of B. anthracis or other spore-forming organisms after such an event before being able to estimate exposure. These challenges include: (1) collecting environmental field samples that are adequate for the intended purpose, (2) conducting laboratory analyses and selecting the reporting format needed for the laboratory data, and (3) analyzing and interpreting the data using appropriate statistical techniques. This paper summarizes some key challenges faced in collecting, analyzing, and interpreting microbial field data from a contaminated site. Although the paper was written with considerations for B. anthracis contamination, it may also be applicable to other bacterial agents. It explores the implications and limitations of using field data for determining environmental concentrations both before and after decontamination. Several findings were of interest. First, to date, the only validated surface/sampling device combinations are swabs and sponge-sticks on stainless steel surfaces, thus limiting availability of quantitative analytical results which could be used for statistical analysis. Second, agreement needs to be reached with the analytical laboratory on the definition of the countable range and on reporting of data below the limit of quantitation. Finally, the distribution of the microbial field data and statistical methods needed for a particular data set could vary depending on these data that were collected, and guidance is needed on appropriate statistical software for handling microbial data. Further, research is needed to develop better methods to estimate human exposure from pathogens using environmental data collected from a field setting.

Fulcrum for the future: the creation of a values-driven culture

This article describes the efforts of a small children's specialty hospital to prepare for a difficult period of restructuring in the marketplace by using the organization's core values as a force for direction, stabilization, and leverage. A best practices model was used to identify values that were a central part of the hospital's cultural heritage but were also critical for ensuring future institutional success. Principles for values definition and implementation provide guidance for other health care institutions.

Adenosine A2 receptor activation attenuates reperfusion injury by inhibiting neutrophil accumulation, superoxide generation and coronary endothelial adherence

This study tests the hypothesis that adenosine A2 receptor activation reduces reperfusion injury by inhibiting neutrophils in a canine model of ischemia and reperfusion. In 16 anesthetized, open-chest dogs, the left anterior descending coronary artery was ligated for 60 min and reperfused for 3 hr. An intracoronary infusion of either the selective adenosine A2 agonist CGS-21680 at 0.2 microgram/kg/min (n = 8) or vehicle (n = 8) was started 5 min before reperfusion and discontinued after 60 min. The area at risk was comparable between vehicle-treated and CGS-21680-treated groups (39.6 +/- 4.1 vs. 37.1 +/- 2.5% of left ventricle). Infarction size, determined with triphenyltetrazolium chloride, was smaller in the CGS-21680-treated group than in the vehicle-treated group (15.4 +/- 2.9 vs. 29.8 +/- 2.3% of area at risk, P < .05 vs. vehicle-treated group). CGS-21680 significantly reduced neutrophil accumulation (myeloperoxidase activity) in the nonnecrotic area at risk tissue, compared with the vehicle-treated group (2.12 +/- 0.5 vs. 6.47 +/- 0.6 U/g of tissue, P < .05 vs. vehicle-treated group). In in vitro studies, CGS-21680 reduced platelet-activating factor (PAF)-activated canine neutrophil adherence to the endothelial surface of normal homologous coronary artery segments. Compared with PAF-stimulated neutrophils (188.4 +/- 9.4 adhered neutrophils/mm2), CGS-21680 reduced adherence close to base-line levels (46.6 +/- 5.8 adhered neutrophils/mm2) at concentrations of 10 microM (65.6 +/- 8.2 adhered neutrophils/mm2, P < .05 vs. PAF-stimulated group) and 50 microM (56.6 +/- 4.6 adhered neutrophils/mm2, P < .05 vs. PAF-stimulated group). Superoxide anion production (cytochrome c reduction) by activated neutrophils was reduced by CGS-21680 from 33.8 +/- 5.0 to 8.9 +/- 3.6 nmol/5 min/5 x 10(5) cells (P < .05 vs. PAF-stimulated group). We conclude that specific A2 receptor stimulation with CGS-21680 at reflow reduces reperfusion injury by inhibiting neutrophil-related processes.

Germinal HPRT splice donor site mutation results in multiple RNA splicing products in T-lymphocyte cultures

We have used peripheral blood T-lymphocyte cultures to analyze the hprt mutation in two Lesch-Nyhan syndrome males who are cousins and to confirm the carrier status of female members of the family. Both cDNA and genomic DNA sequencing studies show that this patient carries a hitherto undescribed single base deletion in the exon 5 donor splice site sequence (I5: +1, delta G, base number 31635). The largest cDNA product contained all nine hprt exons plus an insertion of 66 bases of intron 5, consistent with the use of a cryptic splice site in intron 5 (aag67/gtaagc). This splicing error would result in a chain terminating codon immediately after exon 5 (I5:2-4, taa) and predicts a polypeptide of 133 amino acids. This loss of the normal splice donor site also results in multiple hprt mRNA species, combining the use of the cryptic splice site in intron 5 and splicing errors involving exons 2-6. In addition to defining a new Lesch-Nyhan mutation (hprtHenryville), these results provide insight into aberrant splicing of hprt mRNA in T-lymphocytes.

Computer-Assisted Instruction: A Learner's Viewpoint

Computer-assisted instruction (CAI) is becoming increasingly common in nursing. Insight into factors that facilitate or impede this process was gained through interviews with nursing students who had used one of four computer programs. Content analysis of these interviews found that the CAI experience includes many components. Three overall categories of comments emerged, pertaining to (a) the learner, (b) the learning environment, and (c) software design, including interactive features, how the learning design uses these features to achieve the learning objectives, and the content. This paper discusses elements that facilitate or hinder learning in each area and illustrates each with quotes from the interviews. This article also suggests positive actions that can increase learning through CAI use.