Use of a commercial tissue dissociation system to detect Salmonella-contaminated poultry products.

Successful detection of bacterial pathogens in food can be challenging due to the physical and compositional complexity of the matrix. Different mechanical/physical and chemical methods have been developed to separate microorganisms from food matrices to facilitate detection. The present study benchmarked a commercial tissue digestion system that applies both chemical and physical methods to separate microorganisms from tissues against stomaching, a standard process currently utilized by commercial and regulatory food safety laboratories. The impacts of the treatments on the physical properties of the food matrix were characterized along with the compatibility of the methods with downstream microbiological and molecular detection assays. The results indicate the tissue digestion system can significantly reduce the average particle size of the chicken sample relative to processing via a stomacher (P < 0.001) without adversely affecting either real-time PCR (qPCR) or plate counting assays, which are typically used to detect Salmonella. Furthermore, inoculated chicken treated with the GentleMACS resulted in a significant increase (P < 0.003) in the qPCR's detection capabilities relative to stomached controls. Cohen kappa (κ) coefficient and McNemar's test indicate the plating assays and PCR results agree with measurements obtained via the 3 M Molecular Detection System as defined in the MLG standard (κ > 0.62; P > 0.08). Collectively, the results demonstrate that the technique enables detection of pathogens in meat at lower levels of contamination using current industry standard technologies.

Comparative Genomic Analysis of a Multidrug-Resistant Campylobacter jejuni Strain YH002 Isolated from Retail Beef Liver.

Campylobacter jejuni is a major cause of bacterial gastroenteritis worldwide. In this study, we report the comparative genomic and functional characteristics of C. jejuni YH002 recently isolated from retail beef liver. Whole-genome sequencing and annotation of the strain revealed novel genetic features, including an integrated intact phage element, multiple antimicrobial resistance (AMR) genes, virulence factors, and a Phd-Doc type toxin-antitoxin (TA) system. Phenotypic tests of AMR showed that C. jejuni YH002 was resistant to amoxicillin and tetracycline, which correlates with the AMR genes found in the strain. Comparative analysis of cell motility at genotypic and phenotypic levels identified discernible patterns of amino acid changes, which could explain the variations of motility among C. jejuni strains. Together, these results provide important clues to the genetic mechanisms of AMR and cell motility in C. jejuni. The finding of a Phd-Doc TA system in the genome of C. jejuni YH002 is the first report of this TA system in Campylobacter spp.

Personal exposure of dairy workers to dust, endotoxin, muramic acid, ergosterol, and ammonia on large-scale dairies in the high plains Western United States.

Dairy workers experience a high degree of bioaerosol exposure, composed of an array of biological and chemical constituents, which have been tied to adverse health effects. A better understanding of the variation in the magnitude and composition of exposures by task is needed to inform worker protection strategies. To characterize the levels and types of exposures, 115 dairy workers grouped into three task categories on nine farms in the high plains Western United States underwent personal monitoring for inhalable dust, endotoxin, 3-hydroxy fatty acids (3-OHFA), muramic acid, ergosterol, and ammonia through one work shift. Eighty-nine percent of dairy workers were exposed to endotoxin at concentrations exceeding the recommended exposure guidelines (adjusted for a long work shift). The proportion of workers with exposures exceeding recommended guidelines was lower for inhalable dust (12%), and ammonia (1%). Ergosterol exposures were only measurable on 28% of samples, primarily among medical workers and feed handlers. Milking parlor workers were exposed to significantly higher inhalable dust, endotoxin, 3-OHFA, ammonia, and muramic acid concentrations compared to workers performing other tasks. Development of large modern dairies has successfully made progress in reducing worker exposures and lung disease prevalence. However, exposure to endotoxin, dust, and ammonia continues to present a significant risk to worker health on North American dairies, especially for workers in milking parlors. This study was among the first to concurrently evaluate occupational exposure to assayable endotoxin (lipid A), 3-hydroxy fatty acids or 3-OHFA (a chemical measure of cell bound and noncell-bound endotoxins), muramic acid, ergosterol, and ammonia among workers on Western U.S. dairies. There remains a need for cost-effective, culturally acceptable intervention strategies integrated in OHS Risk Management and production systems to further optimize worker health and farm productivity.

Study on the mechanism of antibacterial action of magnesium oxide nanoparticles against foodborne pathogens.

BACKGROUND: Magnesium oxide nanoparticles (MgO nanoparticles, with average size of 20 nm) have considerable potential as antimicrobial agents in food safety applications due to their structure, surface properties, and stability. The aim of this work was to investigate the antibacterial effects and mechanism of action of MgO nanoparticles against several important foodborne pathogens. RESULTS: Resazurin (a redox sensitive dye) microplate assay was used for measuring growth inhibition of bacteria treated with MgO nanoparticles. The minimal inhibitory concentrations of MgO nanoparticles to 10(4) colony-forming unit/ml (CFU/ml) of Campylobacter jejuni, Escherichia coli O157:H7, and Salmonella Enteritidis were determined to be 0.5, 1 and 1 mg/ml, respectively. To completely inactivate 10(8-9) CFU/ml bacterial cells in 4 h, a minimal concentration of 2 mg/ml MgO nanoparticles was required for C. jejuni whereas E. coli O157:H7 and Salmonella Enteritidis required at least 8 mg/ml nanoparticles. Scanning electron microscopy examination revealed clear morphological changes and membrane structural damage in the cells treated with MgO nanoparticles. A quantitative real-time PCR combined with ethidium monoazide pretreatment confirmed cell membrane permeability was increased after exposure to the nanoparticles. In a cell free assay, a low level (1.1 µM) of H2O2 was detected in the nanoparticle suspensions. Consistently, MgO nanoparticles greatly induced the gene expression of KatA, a sole catalase in C. jejuni for breaking down H2O2 to H2O and O2. CONCLUSIONS: MgO nanoparticles have strong antibacterial activity against three important foodborne pathogens. The interaction of nanoparticles with bacterial cells causes cell membrane leakage, induces oxidative stress, and ultimately leads to cell death.

Rapid identification and classification of Campylobacter spp. using laser optical scattering technology.

Campylobacter jejuni and Campylobacter coli are the two important species responsible for most of the Campylobacter infections in humans. Reliable isolation and detection of Campylobacter spp. from food samples are challenging due to the interferences from complex food substances and the fastidious growth requirements of this organism. In this study, a novel biosensor-based detection called BARDOT (BActerial Rapid Detection using Optical scattering Technology) was developed for high-throughput screening of Campylobacter colonies grown on an agar plate without disrupting the intact colonies. Image pattern characterization and principal component analysis (PCA) of 6909 bacterial colonies showed that the light scatter patterns of C. jejuni and C. coli were strikingly different from those of Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes. Examination of a mixed culture of these microorganisms revealed 85% (34/40) accuracy in differentiating Campylobacter from the other three major foodborne pathogens based on the similarity to the scatter patterns in an established library. The application of BARDOT in real food has been addressed through the analysis of Campylobacter spiked ground chicken and naturally contaminated fresh chicken pieces. Combined with real-time PCR verification, BARDOT was able to identify Campylobacter isolates from retail chicken. Moreover, applying passive filtration to food samples facilitated the isolation of pure Campylobacter colonies and therefore overcame the interference of the food matrix on BARDOT analysis.

In-vitro methods for testing dermal absorption and penetration of toxic gases.

This technical note provides details of an experimental technique for in-vitro skin studies with atmospheric chemical challenge. There appear to be major evidence gaps in relation to dermal exposure of gases. We describe a modification of standard OECD protocols for an atmospheric delivery system which can be used to understand interaction of toxic gases and the skin. The system can be used to examine the mechanisms by which skin uptake occurs. Auxiliary components which allow for parameter variation such as temperature and relative humidity are also described. Methodology presented in this technical note uses examples of gas challenges (ammonia, chlorine) to illustrate its application to gases of differing physicochemical properties. This adapted protocol can be applied in the context of HAZMAT scenarios involving atmospheric toxic chemical release and dermal absorption potential under variable exposure conditions.

Whole Genome Sequences, De Novo Assembly, and Annotation of Antibiotic Resistant Campylobacter jejuni Strains S27, S33, and S36 Newly Isolated from Chicken Meat.

Campylobacter is a leading bacterial cause of gastrointestinal infections in humans and has imposed substantial medical and public health burdens worldwide. Among a total of 39 species in the Campylobacter genus, C. jejuni is the most important species responsible for approx. 90% of human Campylobacter illness. Most cases of the infection were acquired by ingesting undercooked poultry meat due to the high prevalence of Campylobacter in the products. Here, we reported the dataset of raw sequences, de novo assembled and annotated genomes of C. jejuni strains S27, S33, and S36 recently isolated from retail chicken by using PacBio highly accurate long-read sequencing technology combined with bioinformatics tools. Our data revealed several virulence and antibiotic resistance genes in each of the chromosomes, a type IV secretion system in the plasmid (pCjS33) of C. jejuni S33, and a type VI secretion system and a phage in the plasmid (pCjS36) of C. jejuni S36. This study not only provides new sequence data but also extends the knowledge pertaining to the genomic and functional aspects of this important foodborne pathogen, including the genetic determinants of virulence and antibiotic resistance.

Detection and Isolation of Campylobacter spp. from Raw Meat.

This article presents a rapid yet robust protocol for isolating Campylobacter spp. from raw meats, specifically focusing on Campylobacter jejuni and Campylobacter coli. The protocol builds upon established methods, ensuring compatibility with the prevailing techniques employed by regulatory bodies such as the Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) in the USA, as well as the International Organization for Standardization (ISO) in Europe. Central to this protocol is collecting a rinsate, which is concentrated and resuspended in Bolton Broth media containing horse blood. This medium has been proven to facilitate the recovery of stressed Campylobacter cells and reduce the required enrichment duration by 50%. The enriched samples are then transferred onto nitrocellulose membranes on brucella plates. To improve the sensitivity and specificity of the method, 0.45 µm and 0.65 µm pore-size filter membranes were evaluated. Data revealed a 29-fold increase in cell recovery with the 0.65 µm pore-size filter compared to the 0.45 µm pore-size without impacting specificity. The highly motile characteristics of Campylobacter allow cells to actively move through the membrane filters towards the agar medium, which enables effective isolation of pure Campylobacter colonies. The protocol incorporates multiplex quantitative real-time polymerase chain reaction (mqPCR) assay to identify the isolates at the species level. This molecular technique offers a reliable and efficient means of species identification. Investigations conducted over the past twelve years involving retail meats have demonstrated the ability of this method to enhance recovery of Campylobacter from naturally contaminated meat samples compared to current reference methods. Furthermore, this protocol boasts reduced preparation and processing time. As a result, it presents a promising alternative for the efficient recovery of Campylobacter from meat. Moreover, this procedure can be seamlessly integrated with DNA-based methods, facilitating rapid screening of positive samples alongside comprehensive whole-genome sequencing analysis.

Non-stochastic sampling error in quantal analyses for Campylobacter species on poultry products.

Using primers and fluorescent probes specific for the most common food-borne Campylobacter species (Campylobacter jejuni and Campylobacter coli), we developed a multiplex, most probable number (MPN) assay using quantitative PCR (qPCR) as the determinant for binomial detection: i.e., number of p positive pathogen growth responses out of n = 6 observations each of 4 mL (V) per dilution. Working with media washes of thrice frozen-thawed chicken pieces which had been spiked with known levels of C. jejuni and C. coli, we found that about 20% of the experiments had a significant amount of error in the form of either greater than 25% MPN calculation error (Δε) and/or a low apparent recovery rate (R less than 1 = MPN observed ÷ CFU spiked). Assuming such errors were exacerbated by an excessively small n, we examined computer-generated MPN enumeration data from the standpoint of stochastic sampling error (Δ) and found that such binomial-based assays behaved identically to Poisson-based methods (e.g., counting data) except that fewer technical replicates (n) appeared to be required for the same number of cells per test volume (µ). This result implies that the qPCR detection-based MPN protocol discussed herein should accurately enumerate a test population with a µ ≥ 1 using n = 6 observations per dilution. For our protocol, this equates to ≥ 8 cells per 400-500 g of sampled product. Based on this analysis, the error rate we saw in spiked experiments (where µ >> 1) implied a non-stochastic source. In other experiments we present evidence that this source was, at least in part, related to the cell concentration step (i.e., centrifugation). We also demonstrate that the error rate lessened (from ~38% to ~13%) at lower Campylobacter levels (µ ≤ 40) as would most likely exist in nature. Using this protocol, we were able to quantify 14 to 1,226 MPN per 450 g of naturally contaminated chicken for skinless pieces and 11 to 244 MPN per 450 g for wings, breasts, legs, and thighs (skin on) whereupon about 50% of the 29 samples tested negative for both species. Four of these chicken wash samples did have substantially lower Campylobacter levels (1 to 6 MPN per 450 g) which might be better enumerated using a larger n. However, we established that the limit of quantification of this protocol diminishes for n > 6 because one is ever more diluting the sample, or lessening V, to achieve the requisite n.

A current affair: worker perceptions of noise exposure and occupational hearing loss in Australian coal mines.

BACKGROUND: The objective of the online survey was to determine worker attitudes towards, perceptions on hearing loss, and management of workplace noise; and to identify barriers within current strategies that prevent effective management of hearing health in Australian mines. DESIGN: This cross-sectional study utilized a modified survey design, initially designed for use by Safe Work Australia for a broader study published in 2010. STUDY SAMPLE: The survey questionnaire was made available online to volunteer participants, recruited with the assistance of State and National Health and Safety, and mining organizations. Volunteer participants were required to be proficient in English, be employed by an Australian underground or open cut mine, including coal processing plants; or work as a contractor on one of the specified mine sites. All mining employees, regardless of occupation, job title, and occupational hearing loss classification or status, were invited to complete the questionnaire. RESULTS: Almost 60% of respondents indicated that they had high noise exposure for than 10 yr or more, and have some trouble hearing, mostly associated with infrequent tinnitus. Nearly 71% of these workers believe that the noise control strategies in their workplaces are effective, but this mostly refers to the use of hearing protection devices. CONCLUSION: The results indicate that general knowledge on the cause and effect of noise exposure in the workplace is well understood. However, due to the long latency associated with the development of noise-induced hearing loss (NIHL), there is an issue urgency in terms of risk management. It is surprising that most of the respondents recommended more inspections and administrative controls, especially since most respondents were health, safety, and environment (HSE) professionals. HSE professionals should be advocating for higher order, more permanent solutions, and not purely administrative controls and personal protective equipment. These findings raise the question of whether there is a multifaceted working-culture issue that needs to be addressed, in combination with higher order control implementation.

Identifying occupational health and safety risks among environmental health officers in Australia and New Zealand through an online survey.

To identify the occupational health and safety (OHS) risks among environmental health officers (EHOs) in Australia and New Zealand. The objectives were to profile and compare OHS experiences from different countries and regions to gain a regional perspective on OHS hazards that impact EHOs. An online hazard exposure survey was conducted among 339 EHOs (Australia: n = 301, 88.8%; New Zealand: n = 38, 11.2%). The Mann-Whitney U test was used to compare 2 ordinal data groups, the Kruskal-Wallis H test was used for more than 2 ordinal groups, and the independent samples t test was used to compare the means of 2 independent groups where the dependent variables were normally distributed. Multiple regression techniques were used to analyze workplace incidents and age groups. A high degree of similarity in the types of workplace exposures and risk perceptions as well as concerns with organizational OHS management commitment were observed among EHOs from the 2 countries. Workplace violence and physical and psychosocial demands were the most commonly reported OHS hazards. Employer type, sex, and age group were significantly related to workplace exposure and OHS experience among EHOs in both countries. This study provides a profile of workplace exposure in the environmental health profession in the 2 countries and offers recommendations for the implementation of preventive action.

Complete Genome Sequence of Campylobacter jejuni BSD5, a Multidrug-Resistant Isolate from a Poultry Processing Facility in the United States.

Raw poultry can harbor microbial pathogens. Campylobacter jejuni BSD5, isolated from a critical control point within a poultry production plant, was sequenced. Genome annotation revealed several virulence genes including antibiotic resistance genes in agreement with the phenotypic results, indicating a potential risk of this strain to public health.

Complete Genome Sequences of Multidrug-Resistant Campylobacter coli Strains YH501, YH503, and YH504, from Retail Chicken.

Campylobacter coli is an important foodborne pathogen that can cause inflammation of the intestine and diarrhea in humans. The complete genomes, including megaplasmids, of C. coli strains YH501, YH503, and YH504 from retail chicken were sequenced and de novo assembled. Whole-genome analysis revealed a number of virulence and antibiotic resistance genes, suggesting significant potential for these poultry-originating isolates to cause human disease.

Pathogenic Potential of Respirable Spodumene Cleavage Fragments following Application of Regulatory Counting Criteria for Asbestiform Fibres.

Health risks from exposure to lithium-bearing spodumene cleavage fragments are unknown. While asbestiform fibres can lead to fibrosis, mesothelioma and lung cancer, controversy remains whether non-asbestiform cleavage fragments, having equivalent dimensions, elicit similar pathologic responses. The mineralogy of respirable particles from two alpha (α)-spodumene concentrate grades (chemical and technical) were characterised using semi-quantitative X-ray diffraction (XRD). Particles were measured using scanning electron microscopy (SEM) and the dimensions (length [L], diameter [D], aspect ratio [AR]) applied to regulatory counting criteria for asbestiform fibres. Application of the current World Health Organization (WHO) and National Occupational Health and Safety Commission (NOHSC) counting criteria, L ˃ 5 µm, D ˂ 3 µm, AR ˃ 3:1, to 10 SEM images of each grade identified 47 countable particles in the chemical and 37 in the technical concentrate test samples. Of these particles, 17 and 16 in the chemical and technical test samples, respectively, satisfied the more rigorous, previously used Mines Safety and Inspection Regulations 1995 (Western Australia [WA]) criteria, L ˃ 5 µm and D ≤ 1 µm. The majority of the countable particles were consistent with α-spodumene cleavage fragments. These results suggest elongated α-spodumene particles may pose a health risk. It is recommended the precautionary principle be applied to respirable α-spodumene particles and the identification and control of dust hazards in spodumene extraction, handling and processing industries be implemented.

Estimated Financial Impacts of Inaccurate Obese Patient Data Recorded by the Western Australian Country Health Service.

PURPOSE: Pressure on Australia's healthcare system is increasing annually due to corresponding increases in chronic diseases such as obesity and rapidly ageing population growth across Australia, resulting in requirements for increased funding. This study investigates the financial impact to hospitals due to inaccurate obese patient recording and coding. BACKGROUND: Australian healthcare organisations receive Activity-Based Funding (ABF) which provides reimbursement of costs relating to the type of patient care delivered and the resources required for the patient treatment. Accurate healthcare data are essential to ensure accuracy of ABF and appropriate reimbursement of costs incurred by hospitals that manage obese patients. Managing obese patients results in operational funding requirements such as increased staffing and purchasing of equipment such as hoists, bariatric wheelchairs and bariatric beds, and hospitals must ensure that these clinical requirements are documented accurately in order to be reimbursed of these costs by way of ABF. METHODS: This study identifies the financial implications of inaccurate obesity data within the Western Australian Country Health Service (WACHS) and examines factors that may affect obesity data recording accuracy. The study involves 85 cases of identified obesity data recording inaccuracy that were adjusted by entering corrected obesity codes, which then adjusted Diagnosis-related Groups, National Weighted Activity Units and Activity-Based Funding results. RESULTS: The study demonstrated estimated annual lost funding opportunities of $2.23 million due to obesity coding inaccuracy. An annual average of 616 cases of obesity data inaccuracy was calculated with an average lost funding opportunity of $3625 per case. CONCLUSION: Improvements are required in the clinical recording and coding of patient obesity, such as mandatory recording of patient weight and height data and automated BMI calculations within electronic patient records. Enhanced obesity recording and coding accuracy will result in increased funding opportunities and reduced cost burdens that hospitals currently experience when required to fund obesity-related clinical and safety requirements within operational budgets.

Evaluating the Effectiveness of a Clinical Practice Intervention in Increasing Obesity Data Recording at a Western Australian Country Health Service Hospital: A Quasi-Experimental Controlled Trial.

PURPOSE: Identification and mitigation of obesity-related risks to staff and healthcare organisations can occur using patient obesity data; however, a 2017/18 audit of obesity data accuracy was assessed to be poor. This study investigates the results of an intervention to improve obesity data recording and coding accuracy at an Australian hospital. BACKGROUND: Increasing population obesity rates result in increased organisational and financial risks to hospitals. Australian obesity prevalence has steadily increased since 1995, and 42% of the Australian population is predicted to be obese in 2035. To reduce risks to healthcare staff who care for obese patients, complete and accurate obesity recording is required. METHODS: Following a previous audit of obesity recording and coding accuracy of patients admitted to hospital with Type II diabetes, a 12-month intervention was undertaken, comprising staff education, introduction of tape measures and obesity decision-making tools, recording of patient volunteered height, regular reinforcement of obesity recording requirements and enhanced clinical coding of obesity. A re-audit was subsequently conducted to determine if the intervention impacted obesity recording and coding at the previously audited site. RESULTS: Improved recording of obesity-related measures and obesity data accuracy were observed, including increased patient BMI, impacted by increased patient height measurements and increased patient weight measurements. Obesity recording accuracy increased due to the intervention, including increased sensitivity, increased negative predictive values and reduced false negatives. CONCLUSION: The obesity recording intervention was successful; however, as hospitals increasingly use electronic health records, improvement opportunities should be considered such as compulsory recording of patient weight and height, embedded BMI calculators and "check boxes" for recording impacts of obesity conditions on treatment. Immediate improvement of obesity recording in manual patient files can be achieved in the meantime by implementing targets of 100% weight, height and BMI recording, introducing education programs and auditing compliance.

Opportunistic Premise Plumbing Pathogens. A Potential Health Risk in Water Mist Systems Used as a Cooling Intervention.

Water mist systems (WMS) are used for evaporative cooling in public areas. The health risks associated with their colonization by opportunistic premise plumbing pathogens (OPPPs) is not well understood. To advance the understanding of the potential health risk of OPPPs in WMS, biofilm, water and bioaerosol samples (n = 90) from ten (10) WMS in Australia were collected and analyzed by culture and polymerase chain reaction (PCR) methods to detect the occurrence of five representative OPPPs: Legionella pneumophila, Pseudomonas aeruginosa, Mycobacterium avium, Naegleria fowleri and Acanthamoeba. P. aeruginosa (44%, n = 90) occurred more frequently in samples, followed by L. pneumophila serogroup (Sg) 2-14 (18%, n = 90) and L. pneumophila Sg 1 (6%, n = 90). A negative correlation between OPPP occurrence and residual free chlorine was observed except with Acanthamoeba, rs (30) = 0.067, p > 0.05. All detected OPPPs were positively correlated with total dissolved solids (TDS) except with Acanthamoeba. Biofilms contained higher concentrations of L. pneumophila Sg 2-14 (1000-3000 CFU/mL) than water samples (0-100 CFU/mL). This study suggests that WMS can be colonized by OPPPs and are a potential health risk if OPPP contaminated aerosols get released into ambient atmospheres.

Risks to Healthcare Organizations and Staff Who Manage Obese (Bariatric) Patients and Use of Obesity Data to Mitigate Risks: A Literature Review.

This literature review explores obesity risks to healthcare staff and organizations that manage and caring for obese (bariatric) patients. These risks are anticipated to increase due to Australian population obesity rate projections increasing from 31% in 2018 to 42% by the year 2035, which will result in increased hospital admissions of patients with obesity. Literature searches were conducted through the Cumulative Index to Nursing and Allied Health Literature (CINAHL), MEDLINE, Scopus, and Web of Science. Thirty studies met the inclusion criteria and were tabulated and critiqued using appropriate appraisal techniques. High risk of injury to healthcare staff was identified relating to bariatric patient handling tasks. High liability and financial risks of organizations were also identified relating to workers' compensation and common law claims by injured staff and medical negligence claims by patients with obesity. Availability of obesity data was identified within clinically captured information, which could be utilized to inform obesity risk management programs. Future research should focus on improving the use and quality of obesity data to better understand obesity risks to healthcare organizations and staff, including accurate identification of obese patient admissions, enhanced ability to measure bariatric patient handling hazards and related staff injuries and improved assessment of bariatric intervention effectiveness.

Pulsed-Field Gel Electrophoresis Typing of Staphylococcus aureus Strains.

Pulsed-field gel electrophoresis (PFGE) is one of the most effective genotyping methods for the study of genetic relatedness of microorganisms as well as for epidemiologic investigation of outbreaks caused by pathogenic bacteria, including Staphylococcus aureus. The technique relies on the size patterns of large DNA fragments generated by the cleavage of intact bacterial chromosomes with a rare cutting restriction enzyme, and subsequently resolved by pulsed-field electrophoresis with periodic changes of the orientation of the electrical field across the gel. The high discriminatory power, improved reproducibility by standardization of experimental protocols and data analysis guidelines, and establishment of a national PFGE database of S. aureus profiles have made it a valuable means for global tracking of S. aureus infection sources and determination of genetic relatedness of the strains.

Assessment of Worker Exposure to Occupational Organic Dust in a Hemp Processing Facility.

The cultivation and processing of industrial hemp, Cannabis sativa L., is a developing industry in Australia. Exposure to hemp dust is demonstrated as producing reactive and respiratory health effects, potentially causing permanent lung disease or damage. The aim of this study was to assess the airborne organic dust concentrations generated in an Australian hemp processing facility. Personal sampling, in the breathing zone of exposed workers was undertaken for exposure to respirable dust, along with parallel static sampling for airborne concentrations of inhalable and respirable dust fractions. Both static and personal sampling showed that respirable dust concentrations (mg m-3) exceeded the Australian Institute of Occupational Hygienists (AIOH) recommended maximum exposure limit of 1 mg m-3 (respirable fraction) for dusts not otherwise specified, with mean exposures (mg m-3) of M = 1.33, standard deviation (SD) = 1.09 (range 0.07-3.67 mg m-3) and M = 4.49, SD = 4.49 (range 0.77-11.08 mg m-3). The results of the investigation indicate that workers in the hemp processing industry are at risk of developing permanent and disabling respiratory disease due to high dust exposure. There is no Australian occupational exposure limit specifically for hemp dust. It is recommended further research is needed and industry-specific guidance material or model code of practice developed to effectively control exposures.