Mycotoxin contamination and the nutritional content of corn targeted for animal feed.

Mycotoxin contaminated corn poses a risk to poultry production. Although mycotoxin regulatory guidelines are based on the hazards of individual mycotoxin contamination, feed and feed ingredients may be contaminated with multiple mycotoxins. The objective of this study was to assess mycotoxin co-contamination and its impact on the nutrient content of corn grain. Corn samples (n = 328) originating from various regions in the Southeastern U.S. were quantitatively analyzed for fumonisin (FUM), deoxynivalenol (DON), aflatoxin (AFB1) and zearalenone (ZEA) by HPLC-MS/MS. Nutritional content was analyzed by near-infrared spectroscopy, and color data were collected. All 328 samples were found to be contaminated with at least 1 mycotoxin: 100% contained FUM (19-24,680 µg/kg), 69.82% contained DON (0-9,640 µg/kg), 17.07% contained AFB1 (0-939 µg/kg), and 43.60% had detectable levels of ZEA (0-8,093.5 µg/kg). Most of the samples were contaminated with 2 or more mycotoxins, with only 18.29% of the samples containing a single mycotoxin. 38.41% of the samples had 2 mycotoxins present, 36.59 % had 3 mycotoxins, and 4.88% of the samples had all 4 tested mycotoxins present. Samples contaminated with AFB1 had significantly lower fat (P = 0.007) and lightness (P = 0.007); samples contaminated with DON had significantly higher starch (P < 0.001) and lower protein (P < 0.001). Samples contaminated with FUM had significantly higher protein (P = 0.008) and moisture (P = 0.019) and lower starch (P < 0.001). ZEA contaminated samples had significantly lower starch (P = 0.034). A correlation was observed between mycotoxin contamination and altered nutrient content in corn. This study provides further evidence that co-contamination of mycotoxins is the norm in corn, and that mycotoxin contamination correlates with impacts on the nutrient profile of feed corn.

Susceptibility of pESI positive Salmonella to treatment with biocide chemicals approved for use in poultry meat processing as compared to Salmonella without the pESI plasmid.

Salmonella is a common cause of human foodborne illness, which is frequently associated with consumption of contaminated or undercooked poultry meat. Serotype Infantis is among the most common serotypes isolated from poultry meat products globally. Isolates of serotype Infantis carrying the pESI plasmid, the most dominant strain of Infantis, have been shown to exhibit oxidizer tolerance. Therefore, 16 strains of Salmonella with and without pESI carriage were investigated for susceptibility to biocide chemical processing aids approved for use in US poultry meat processing: peracetic acid (PAA), cetylpyridinium chloride (CPC), calcium hypochlorite, and sodium hypochlorite. Strains were exposed for 15 s to simulate spray application and 90 min to simulate application in an immersion chiller. All strains tested were susceptible to all concentrations of PAA, CPC, and sodium hypochlorite when applied for 90 min. When CPC, calcium hypochlorite, and sodium hypochlorite were applied for 15 s to simulate spray time, strains responded similarly to each other. However, strains responded variably to exposure to PAA. The variation was not statistically significant and appears unrelated to pESI carriage. Results highlight the necessity of testing biocide susceptibility in the presence of organic material and in relevant in situ applications.

Macro-micro exploration on dynamic interaction between aflatoxigenic Aspergillus flavus and maize kernels using Vis/NIR hyperspectral imaging and SEM technology.

Aspergillus flavus and its toxic metabolites-aflatoxins infect and contaminate maize kernels, posing a threat to grain safety and human health. Due to the complexity of microbial growth and metabolic processes, dynamic mechanisms among fungal growth, nutrient depletion of maize kernels and aflatoxin production is still unclear. In this study, visible/near infrared (Vis/NIR) hyperspectral imaging (HSI) combined with the scanning electron microscope (SEM) was used to elucidate the critical organismal interaction at kernel (macro-) and microscopic levels. As kernel damage is the main entrance for fungal invasion, maize kernels with gradually aggravated damages from intact to pierced to halved kernels with A. flavus were cultured for 0-120 h. The spectral fingerprints of the A. flavus-maize kernel complex over time were analyzed with principal components analysis (PCA) of hyperspectral images, where the pseudo-color score maps and the loading plots of the first three PCs were used to investigate the dynamic process of fungal infection and to capture the subtle changes in the complex with different hardness of the maize matrix. The dynamic growth process of A. flavus and the interactions of fungus-maize complexes were explained on a microscopic level using SEM. Specifically, fungus morphology, e.g., hyphae, conidia, and conidiophore (stipe) was accurately captured on the microscopic level, and the interaction process between A. flavus and nutrient loss from the maize kernel tissues (i.e., embryo, and endosperm) was described. Furthermore, the growth stage discrimination models based on PLSDA with the results of CCRC = 100 %, CCRV = 97 %, CCRIV = 93 %, and the prediction models of AFB1 based on PLSR with satisfactory performance (R2C = 0.96, R2V = 0.95, R2IV = 0.93 and RPD = 3.58) were both achieved. In conclusion, the results from both macro-level (Vis/NIR-HSI) and micro-level (SEM) assessments revealed the dynamic organismal interactions in A. flavus-maize kernel complex, and the detailed data could be used for modeling, and quantitative prediction of aflatoxin, which would establish a theoretical foundation for the early detection of fungal or toxin contaminated grains to ensure food security.

Synergistic Effects of Essential Oils and Organic Acids against Aspergillus flavus Contamination in Poultry Feed.

Organic acids and essential oils are commonly used in the poultry industry as antimicrobials and for their beneficial effects on gut health, growth performance, and meat quality. A common postharvest storage fungal colonist, Aspergillus flavus, contaminates corn, the primary component of poultry feed, with the highly detrimental mycotoxin, aflatoxin. Aflatoxin adversely affects poultry feed intake, feed conversion efficiency, weight gain, egg production, fertility, hatchability, and poultry meat yield. Both organic acids and essential oils have been reported to inhibit the growth of A. flavus. Thus, we evaluated if the inhibitory synergy between combined essential oils (cinnamon, lemongrass, and oregano) and organic acids (acetic, butyric, and propionic) prevents A. flavus growth. The study confirmed that these compounds inhibit the growth of A. flavus and that synergistic interactions do occur between some of them. Overall, cinnamon oil was shown to have the highest synergy with all the organic acids tested, requiring 1000 µL/L air of cinnamon oil and 888 mg/kg of butyric acid to fully suppress A. flavus growth on corn kernels. With the strong synergism demonstrated, combining certain essential oils and organic acids offers a potentially effective natural method for controlling postharvest aflatoxin contamination in poultry feed.

Fusarium verticillioides NAT1 (FDB2) N-malonyltransferase is structurally, functionally and phylogenetically distinct from its N-acetyltransferase (NAT) homologues.

Fusarium endophytes damage cereal crops and contaminate produce with mycotoxins. Those fungi overcome the main chemical defence of host via detoxification by a malonyl-CoA-dependent enzyme homologous to xenobiotic metabolizing arylamine N-acetyltransferase (NAT). In Fusarium verticillioides (teleomorph Gibberella moniliformis, GIBMO), this N-malonyltransferase activity is attributed to (GIBMO)NAT1, and the fungus has two additional isoenzymes, (GIBMO)NAT3 (N-acetyltransferase) and (GIBMO)NAT2 (unknown function). We present the crystallographic structure of (GIBMO)NAT1, also modelling other fungal NAT homologues. Monomeric (GIBMO)NAT1 is distinctive, with access to the catalytic core through two "tunnel-like" entries separated by a "bridge-like" helix. In the quaternary arrangement, (GIBMO)NAT1 monomers interact in pairs along an extensive interface whereby one entry of each monomer is covered by the N-terminus of the other monomer. Although monomeric (GIBMO)NAT1 apparently accommodates acetyl-CoA better than malonyl-CoA, dimerization changes the active site to allow malonyl-CoA to reach the catalytic triad (Cys110, His158 and Asp173) via the single uncovered entry, and anchor its terminal carboxyl-group via hydrogen bonds to Arg109, Asn157 and Thr261. Lacking a terminal carboxyl-group, acetyl-CoA cannot form such stabilizing interactions, while longer acyl-CoAs enter the active site but cannot reach catalytic Cys. Other NAT isoenzymes lack such structural features, with (GIBMO)NAT3 resembling bacterial NATs and (GIBMO)NAT2 adopting a structure intermediate between (GIBMO)NAT1 and (GIBMO)NAT3. Biochemical assays confirmed differential donor substrate preference of (GIBMO)NAT isoenzymes, with phylogenetic analysis demonstrating evolutionary separation. Given the role of (GIBMO)NAT1 in enhancing Fusarium pathogenicity, unravelling the structure and function of this enzyme may benefit research into more targeted strategies for pathogen control.

Emerging utility of endovascular thrombectomy in the Philippines: A single-center clinical experience

Background and Objective@#Stroke has remained one of the primary causes of significant morbidity and mortality. Among the therapeutic options for acute stroke management, endovascular thrombectomy is intended to remove the thrombi within the intracerebral vasculature and restore adequate perfusion to the surrounding penumbra. It is recommended up to 24 hours from onset of neurologic symptom. In the Philippines, only a few tertiary healthcare institutions are able to offer and perform endovascular thrombectomies. The aim was to describe the profile and discharge outcomes of endovascular thrombectomy for acute ischemic stroke at a tertiary hospital in our country. @*Methods@#We conducted a retrospective records review among 924 patients admitted for acute ischemic stroke from October 2018 to August 2021 who underwent mechanical thrombectomy. Clinical and functional outcomes were measured using the National Institutes of Health Stroke Scale (NIHSS) and Modified Rankin Score (mRS). @*Results@#Among 31 patients included in the study, 29 subjects (93.5%) had moderate to severe disability (mRS 3–5), and 25 (80.6%) had moderate stroke (NIHSS 6–21) on admission. The identified site of the cerebrovascular thrombi was within the M1 segment of the middle cerebral artery (41.9%, n=13). The stent retriever approach was performed in 19 participants (61.2%). Upon discharge, only 7 (22.6%) had favorable functional outcomes (MRS 0–2), and 9 (29.0%) resulted in mortality. Successful reperfusion was achieved in 92.3% of the patients.@*Conclusion@#Overall, endovascular thrombectomy is a possible treatment option for large vessel acute ischemic stroke in developing countries.

Survey of Meat Collected from Commercial Broiler Processing Plants Suggests Low Levels of Semicarbazide Can Be Created during Immersion Chilling.

ABSTRACT: Semicarbazide (SEM) is routinely employed as an indicator for the use of nitrofurazone, a banned antimicrobial. The validity of SEM as a nitrofurazone marker has been scrutinized because of other possible sources of the compound. Nonetheless, a U.S. trade partner rejected skin-on chicken thighs because of SEM detection and suspected nitrofurazone use. Because nitrofurazone has been banned in U.S. broiler production since 2003, we hypothesized that incidental de novo SEM formation occurs during broiler processing. To assess this possibility, raw leg quarters were collected from 23 commercial broiler processing plants across the United States and shipped frozen to our laboratory, where liquid chromatography-mass spectrometry was used to quantitatively assess for SEM. Leg quarter samples were collected at four points along the processing line: hot rehang (transfer from the kill line to the evisceration line), prechill (before the chilling process), postchill (immediately following chilling), and at the point of pack. Thigh meat with skin attached was removed from 535 leg quarters and analyzed in triplicate for SEM concentrations. The concentrations ranged from 0 to 2.67 ppb, with 462 (86.4%) of 535 samples below the regulatory decision level of 0.5 ppb of SEM. The 73 samples over the 0.5-ppb limit came from 21 plants; 53 (72.6%) of positive samples were in meat collected after chilling (postchill or point of pack). The difference in both prevalence and concentration of SEM detected before and after chilling was highly significant (P < 0.0001). These data support our hypothesis that SEM detection in raw broiler meat is related to de novo creation of the chemical during processing.

Spatio-temporal patterns of Aspergillus flavus infection and aflatoxin B1 biosynthesis on maize kernels probed by SWIR hyperspectral imaging and synchrotron FTIR microspectroscopy.

The dynamics mechanisms regulating the growth and AFB1 production of Aspergillus flavus during its interactions with maize kernels remain unclear. In this study, shortwave infrared hyperspectral imaging (SWIR-HSI) and synchrotron radiation Fourier transform infrared (SR-FTIR) microspectroscopy were combined to investigate chemical and spatial-temporal changes in incremental damaged maize kernels induced by A. flavus infection at macroscopic and microscopic levels. SWIR-HSI was employed to extract spectral information of A. flavus growth and quantitatively detect AFB1 levels. Satisfactory full-spectrum models and simplified multispectral models were obtained respectively by partial least squares regression (PLSR) for three types of samples. Furthermore, SR-FTIR microspectroscopy coupled with two-dimensional correlation spectroscopy (2DCOS) was utilized to reveal the possible sequence of dynamic changes of nutrient loss and trace AFB1 in maize kernels. It exhibited new insights on how to quantify the spatio-temporal patterns of fungal infection and AFB1 accumulation on maize and provided theoretical basis for online sorting.

Transcriptomic Responses of Fusarium verticillioides to Lactam and Lactone Xenobiotics.

The important cereal crops of maize, rye, and wheat constitutively produce precursors to 2-benzoxazolinone, a phytochemical having antifungal effects towards many Fusarium species. However, Fusarium verticillioides can tolerate 2-benzoxazolinone by converting it into non-toxic metabolites through the synergism of two previously identified gene clusters, FDB1 and FDB2. Inspired by the induction of these two clusters upon exposure to 2-benzoxazolinone, RNA sequencing experiments were carried out by challenging F. verticillioides individually with 2-benzoxazolinone and three related chemical compounds, 2-oxindole, 2-coumaranone, and chlorzoxazone. These compounds all contain lactam and/or lactone moieties, and transcriptional analysis provided inferences regarding the degradation of such lactams and lactones. Besides induction of FDB1 and FDB2 gene clusters, four additional clusters were identified as induced by 2-benzoxazolinone exposure, including a cluster thought to be responsible for biosynthesis of pyridoxine (vitamin B6), a known antioxidant providing tolerance to reactive oxygen species. Three putative gene clusters were identified as induced by challenging F. verticillioides with 2-oxindole, two with 2-coumaranone, and two with chlorzoxazone. Interestingly, 2-benzoxazolinone and 2-oxindole each induced two specific gene clusters with similar composition of enzymatic functions. Exposure to 2-coumranone elicited the expression of the fusaric acid biosynthetic gene cluster. Another gene cluster that may encode enzymes responsible for degrading intermediate catabolic metabolites with carboxylic ester bonds was induced by 2-benzoxazolinone, 2-oxindole, and chlorzoxazone. Also, the induction of a dehalogenase encoding gene during chlorzoxazone exposure suggested its role in the removal of the chlorine atom. Together, this work identifies genes and putative gene clusters responsive to the 2-benzoxazolinone-like compounds with metabolic inferences. Potential targets for future functional analyses are discussed.

Transcriptomic Response of Fusarium verticillioides to Variably Inhibitory Environmental Isolates of Streptomyces.

Fusarium verticillioides is a mycotoxigenic fungus that is a threat to food and feed safety due to its common infection of maize, a global staple crop. A proposed strategy to combat this threat is the use of biological control bacteria that can inhibit the fungus and reduce mycotoxin contamination. In this study, the effect of multiple environmental isolates of Streptomyces on F. verticillioides was examined via transcriptome analysis. The Streptomyces strains ranged from inducing no visible response to dramatic growth inhibition. Transcriptionally, F. verticillioides responded proportionally to strain inhibition with either little to no transcript changes to thousands of genes being differentially expressed. Expression changes in multiple F. verticillioides putative secondary metabolite gene clusters was observed. Interestingly, genes involved in the fusaric acid gene cluster were suppressed by inhibitory strains of Streptomyces. A F. verticillioides beta-lactamase encoding gene (FVEG_13172) was found to be highly induced by specific inhibitory Streptomyces strains and its deletion increased visible response to those strains. This study demonstrates that F. verticillioides does not have an all or nothing response to bacteria it encounters but rather a measured response that is strain specific and proportional to the strength of inhibition.

Phylogenomic Analysis of a 55.1-kb 19-Gene Dataset Resolves a Monophyletic Fusarium that Includes the Fusarium solani Species Complex.

Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.

Identifying candidate Aspergillus pathogenicity factors by annotation frequency.

BACKGROUND: Members of the genus Aspergillus display a variety of lifestyles, ranging from saprobic to pathogenic on plants and/or animals. Increased genome sequencing of economically important members of the genus permits effective use of "-omics" comparisons between closely related species and strains to identify candidate genes that may contribute to phenotypes of interest, especially relating to pathogenicity. Protein-coding genes were predicted from 216 genomes of 12 Aspergillus species, and the frequencies of various structural aspects (exon count and length, intron count and length, GC content, and codon usage) and functional annotations (InterPro, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes terms) were compared. RESULTS: Using principal component analyses, the three sets of functional annotations for each strain were clustered by species. The species clusters appeared to separate by pathogenicity on plants along the first dimensions, which accounted for over 20% of the variance. More annotations for genes encoding pectinases and secondary metabolite biosynthetic enzymes were assigned to phytopathogenic strains from species such as Aspergillus flavus. In contrast, Aspergillus fumigatus strains, which are pathogenic to animals but not plants, were assigned relatively more terms related to phosphate transferases, and carbohydrate and amino-sugar metabolism. Analyses of publicly available RNA-Seq data indicated that one A. fumigatus protein among 17 amino-sugar processing candidates, a hexokinase, was up-regulated during co-culturing with human immune system cells. CONCLUSION: Genes encoding hexokinases and other proteins of interest may be subject to future manipulations to further refine understanding of Aspergillus pathogenicity factors.

Pyrrocidine, a molecular off switch for fumonisin biosynthesis.

Sarocladium zeae is a fungal endophyte of maize and can be found co-inhabiting a single seed with Fusarium verticillioides, a major mycotoxigenic food safety threat. S. zeae produces pyrrocidines A and B that inhibit the growth of F. verticillioides and may limit its spread within the seed to locations lacking S. zeae. Although coinhabiting single seeds, the fungi are generally segregated in separate tissues. To understand F. verticillioides' protective physiological response to pyrrocidines we sequenced the F. verticillioides transcriptome upon exposure to purified pyrrocidine A or B at sub-inhibitory concentrations. Through this work we identified a F. verticillioides locus FvABC3 (FVEG_11089) encoding a transporter critical for resistance to pyrrocidine. We also identified FvZBD1 (FVEG_00314), a gene directly adjacent to the fumonisin biosynthetic gene cluster that was induced several thousand-fold in response to pyrrocidines. FvZBD1 is postulated to act as a genetic repressor of fumonisin production since deletion of the gene resulted in orders of magnitude increase in fumonisin. Further, pyrrocidine acts, likely through FvZBD1, to shut off fumonisin biosynthesis. This suggests that S. zeae is able to hack the secondary metabolic program of a competitor fungus, perhaps as preemptive self-protection, in this case impacting a mycotoxin of central concern for food safety.

Genome-wide analysis of Fusarium verticillioides reveals inter-kingdom contribution of horizontal gene transfer to the expansion of metabolism.

Horizontal gene transfer (HGT) is believed to shape genomes by facilitating the rapid acquisition of adaptive traits. We hypothesized that the economically important fungus Fusarium verticillioides is an excellent candidate for investigating the potential impact of HGT on the expansion of metabolic activities given its soilborne nature and versatile lifestyle as both a symptomless endophyte as well as a maize pathogen. To test this hypothesis, we used a phylogenomic pipeline followed by manual curation to perform a genome-wide identification of inter-kingdom derived HGT events. We found strong support for 36 genes in F. verticillioides putatively acquired from bacteria. Functional enrichment assessment of these 36 candidates suggested HGT potentially influenced several biochemical activities, including lysine, glycine and nitrogen metabolism. The expression of 25 candidate HGT genes was detected among RNA-Seq datasets from normal and various stress-related growth conditions, thus indicating potential functionality. FVEG_10494, one of the HGT candidates with homologs in only a few Fusarium species, was highly and specifically up-regulated under nitric oxide (NO) challenge. Functional analysis of FVEG_10494 suggests the gene moderately enhanced NO-triggered protective responses and suppressed expression of the F. verticillioides secondary metabolism gene cluster responsible for production of fusarin C. Overall, our global analysis of HGT events in F. verticillioides identified a well-supported set of transferred genes, providing further evidence that HGT offers a mechanism by which fungi can expand their metabolic capabilities, which in turn may enhance their adaptive strategies.

Application of Data Provenance in Healthcare Analytics Software: Information Visualisation of User Activities.

Data provenance is a technique that describes the history of digital objects. In health data settings, it can be used to deliver auditability and transparency, and to achieve trust in a software system. However, implementing data provenance in analytics software at an enterprise level presents a different set of challenges from the research environments where data provenance was originally devised. In this paper, the challenges of reporting provenance information to the user is presented. Provenance captured from analytics software can be large and complex and visualizing a series of tasks over a long period can be overwhelming even for a domain expert, requiring visual aggregation mechanisms that fit with complex human cognitive activities involved in the process. This research studied how provenance-based reporting can be integrated into a health data analytics software, using the example of Atmolytics visual reporting tool.

Fusarium verticillioides: Advancements in Understanding the Toxicity, Virulence, and Niche Adaptations of a Model Mycotoxigenic Pathogen of Maize.

The importance of understanding the biology of the mycotoxigenic fungus Fusarium verticillioides and its various microbial and plant host interactions is critical given its threat to maize, one of the world's most valuable food crops. Disease outbreaks and mycotoxin contamination of grain threaten economic returns and have grave implications for human and animal health and food security. Furthermore, F. verticillioides is a member of a genus of significant phytopathogens and, thus, data regarding its host association, biosynthesis of secondary metabolites, and other metabolic (degradative) capabilities are consequential to both basic and applied research efforts across multiple pathosystems. Notorious among its secondary metabolites are the fumonisin mycotoxins, which cause severe animal diseases and are implicated in human disease. Additionally, studies of these mycotoxins have led to new understandings of F. verticillioides plant pathogenicity and provide tools for research into cellular processes and host-pathogen interaction strategies. This review presents current knowledge regarding several significant lines of F. verticillioides research, including facets of toxin production, virulence, and novel fitness strategies exhibited by this fungus across rhizosphere and plant environments.

Characterization of two catalase-peroxidase-encoding genes in Fusarium verticillioides reveals differential responses to in vitro versus in planta oxidative challenges.

Catalase-peroxidases (KatGs) are a superfamily of reactive oxygen species (ROS)-degrading enzymes believed to have been horizontally acquired by ancient Ascomycota from bacteria. Subsequent gene duplication resulted in two KatG paralogues in ascomycetes: the widely distributed intracellular KatG1 group and the phytopathogen-dominated extracellular KatG2 group. To functionally characterize FvCP01 (KatG1) and FvCP02 (KatG2) in the maize pathogen Fusarium verticillioides, single and double gene deletion mutants were examined in response to hydrogen peroxide (H2 O2 ). Both ΔFvCP01 and ΔFvCP02 were more sensitive to H2 O2 than the wild-type in vitro, although their sensitivity differed depending on the type of inoculum. Inoculations using mycelial agar plugs demonstrated an additive effect of the mutants, with the ΔFvCP01/ΔFvCP02 double deletion being the most sensitive to H2 O2 . In general, conidia were much more sensitive than agar plugs to H2 O2 , and conidial inoculations indicated that FvCP01 conferred more H2 O2 tolerance than FvCP02. Transcriptional analysis showed the induction of FvCP01, but decreased expression of FvCP02, in both mycelia and spores in the wild-type after H2 O2 exposure, but this trend was reversed when the fungus was grown on germinating maize seeds. This interaction with the plant increased the expression of FvCP02, but not FvCP01, indicating that FvCP02 may be responsive to plant-derived H2 O2 . Yet, FvCP01 was induced more than three-fold in the ΔFvCP02 mutant grown on germlings, suggesting that FvCP01 can compensate for the loss of FvCP02. Given the differential responses of these two F. verticillioides genes to in vitro versus in planta challenges, a model is proposed to illustrate the differing roles of FvCP01 and FvCP02 in protective responses against H2 O2 -derived oxidative stress.

Insurance workers' and physiotherapists' perceptions of their roles in the management of workers with injuries in the Western Australian workers' compensation system.

BACKGROUND: Insurance workers and physiotherapists are important stakeholders in the rehabilitation of workers with an injury and subsequent musculoskeletal pain. Understanding perceptions of roles may facilitate communication between these stakeholders. OBJECTIVE: Increase knowledge around, (i) the self-perception of and (ii) the external perception of the insurance workers and physiotherapists roles in the management of a worker with an injury in an Australian workers' compensation environment. METHODS: A cross-sectional study assessed the perceptions of insurance workers and physiotherapists related to the roles of these two professions in managing a worker with an injury via questionnaire. Respondents were also asked about potential communication barriers. RESULTS: Insurance workers (n = 48) and physiotherapists (n = 80) reported contrasting role perceptions, with their perception of the other profession leaning towards negative attributes. There was greater alignment of their beliefs of roles in the 'ideal' situation. The perception of barriers to communication also differed between the two professions. Effective and efficient communication was identified as a central component of mismatched role perceptions between stakeholders, but recognised as a critical attribute of 'ideal' stakeholder roles. CONCLUSION: Insurance workers and physiotherapists self-perception of their roles differs from external perceptions. This information highlights the importance of a shared understanding of stakeholder roles in the management of a worker with an injury.

Fungal Lactamases: Their Occurrence and Function.

Fungi are absorptive feeders and thus must colonize and ramify through their substrate to survive. In so doing they are in competition, particularly in the soil, with myriad microbes. These microbes use xenobiotic compounds as offensive weapons to compete for nutrition, and fungi must be sufficiently resistant to these xenobiotics. One prominent mechanism of xenobiotic resistance is through production of corresponding degrading enzymes. As typical examples, bacterial ß-lactamases are well known for their ability to degrade and consequently confer resistance to ß-lactam antibiotics, a serious emerging problem in health care. We have identified many fungal genes that putatively encode proteins exhibiting a high degree of similarity to ß-lactamases. However, fungal cell walls are structurally different from the bacterial peptidoglycan target of ß-lactams. This raises the question, why do fungi have lactamases and what are their functions? Previously, we identified and characterized one Fusarium verticillioides lactamase encoding gene (FVEG_08291) that confers resistance to the benzoxazinoid phytoanticipins produced by maize, wheat, and rye. Since benzoxazinoids are γ-lactams with five-membered rings rather than the four-membered ß-lactams, we refer to the predicted enzymes simply as lactamases, rather than ß-lactamases. An overview of fungal genomes suggests a strong positive correlation between environmental niche complexity and the number of fungal lactamase encoding genes, with soil-borne fungi showing dramatic amplification of lactamase encoding genes compared to those fungi found in less biologically complex environments. Remarkably, Fusarium species frequently possess large (>40) numbers of these genes. We hypothesize that many fungal hydrolytic lactamases are responsible for the degradation of plant or microbial xenobiotic lactam compounds. Alignment of protein sequences revealed two conserved patterns resembling bacterial ß-lactamases, specifically those possessing PFAM domains PF00753 or PF00144. Structural predictions of F. verticillioides lactamases also suggested similar catalytic mechanisms to those of their bacterial counterparts. Overall, we present the first in-depth analysis of lactamases in fungi, and discuss their potential relevance to fitness and resistance to antimicrobials in the environment.