Antimicrobial-resistant Salmonella is detected more frequently in feed milling equipment than in raw feed components or processed animal feed.

Food for human and animal consumption can provide a vehicle for the transfer of pathogenic and antimicrobial-resistant bacteria into the food chain. We investigated the antimicrobial susceptibility of 453 Salmonella isolates collected from raw feed components, equipment and finished feed from 17 commercial feed mills in Australia between 2012 and 2021. Previous studies have found Salmonella prevalence and the diversity of Salmonella serotypes are greatest in the raw feed components. We, therefore, hypothesised that we would find a greater proportion of antimicrobial-resistant Salmonella isolates in the raw feed components compared to other sample types. We found that of 453 isolates tested, 356 (0.80) were susceptible to all antimicrobials tested, 49 (0.11) were nonsusceptible to streptomycin only and 48 (0.11) were resistant to two or more antimicrobials. Of the 48 antimicrobial-resistant isolates, 44 were found in feed milling equipment, two in raw feed components and two in finished feed. Statistical analysis, using a logistic regression with random effects model, found that the population-adjusted mean probability of detecting antimicrobial-resistant Salmonella isolates from feed milling equipment of 0.39, was larger than the probability of detecting resistant isolates in raw feed components 0.01, (P < 0.001) and in finished feed, 0.11, (P = 0.006). This propensity for antimicrobial-resistant bacteria to colonise feed milling equipment has not been previously reported. Further studies are required to understand the ecology of antimicrobial-resistant Salmonella in the feed milling environment.

Salmonella monitoring programs in Australian feed mills: a retrospective analysis.

The availability of safe, commercially prepared stock feed for production animals is an important step in ensuring animal health and welfare and the safety of food animal products for human consumption. Animal feed quality assurance programs include microbiological monitoring of raw materials, mill equipment and finished feed. Over a period of 16 years, 23,963 samples for Salmonella culture and serotyping were collected from 22 stock feed mills. A multivariable generalized linear mixed model (GLMM) was used to identify mill and sample type factors that increase the odds of detecting Salmonella. The odds of detecting a Salmonella positive sample was greatest in samples from raw materials and in mills that processed restricted animal material (RAM). The percentage of positive samples ranged from 7.2% in 2003 to 2.8% in 2017. Of the 1,069 positive samples, 976 were serotyped with 61 different Salmonella serotypes isolated. The serotype most frequently isolated from raw materials was S. Agona, (n = 108) whilst S. Anatum was the serotype most frequently isolated from equipment and finished feed (n = 156). The diversity of Salmonella serotypes differed between mills and different stages of the production line. Microbiological monitoring in the commercial preparation of animal feed in Australian stock feed mills guides the implementation of quality control measures and risk mitigation strategies thereby reducing the prevalence and diversity of potentially zoonotic bacteria such as Salmonella, enhancing food safety for both animal and consumer.

Hypovitaminosis A in extensively grazed beef cattle.

CASE REPORT: Vitamin A deficiency was diagnosed in a herd of 97 19-month-old Braford heifers in the Mitchell Grass Downs (Astrebla spp.) bioregion of Hughenden in north-western Queensland during November 2015. Two heifers died after a 48-h history of sternal recumbency and of the 19 that had neurological signs, 7 were blind. Histological changes in the optic nerves of the two necropsied cattle were consistent with vitamin A deficiency. This diagnosis was supported by vitamin A concentrations in fresh liver samples of 5 and 6 mg/kg wet tissue (reference range, 100-175 mg/kg) despite treatment of the cattle with twice the recommended dose of parenteral vitamin A 3 weeks prior to sampling. Rainfall on the property during the 2 years before the outbreak was less than the annual rainfall average of 464 mm, with a total of 281 mm in 2014 and 117 mm from January to November in 2015, most of this falling in January. CONCLUSION: Plant assays for both ß-carotene and crude protein concentrations in dry matter (DM) were less than the recommended dietary requirements for beef cattle (0.30 mg/kg DM and 56 g/kg, respectively).

Fire and scald burn risks in urban communities: who is at risk and what do they believe about home safety?

While largely preventable, fire and hot water-related injuries are common in the United States. Measures recommended to reduce these injuries are smoke alarms (SAs) and lowered hot water temperatures. This study aims to: (i) describe the prevalence of working SAs and safe water temperatures among low-income, urban communities and (ii) explore the relationship between these behaviors and individuals' knowledge and beliefs about them. In this cross-sectional study, the Health Belief Model was used as a guide for understanding the safety behaviors. A total of 603 households had their SAs and hot tap water temperatures tested and were surveyed about their knowledge and beliefs related to these safety behaviors. We found that 40% of households had working SAs on every level and 57% had safe hot water temperatures. Perceived severity and self-efficacy were significantly associated with SA coverage, whereas perceived susceptibility and beliefs about benefits were significantly associated with safe hot water temperatures. This study demonstrates the need to increase the number of homes with working SAs and safe hot water temperatures. Messages focused on a safe home environment could communicate the ease and harm reduction features of SAs and benefits and risk reduction features of safe hot water temperatures.

Development of an algorithm for assessing the risk to food safety posed by a new animal disease.

An algorithm was developed as a tool to rapidly assess the potential for a new or emerging disease of livestock to adversely affect humans via consumption or handling of meat product, so that the risks and uncertainties can be understood and appropriate risk management and communication implemented. An algorithm describing the sequence of events from occurrence of the disease in livestock, release of the causative agent from an infected animal, contamination of fresh meat and then possible adverse effects in humans following meat handling and consumption was created. A list of questions complements the algorithm to help the assessors address the issues of concern at each step of the decision pathway. The algorithm was refined and validated through consultation with a panel of experts and a review group of animal health and food safety policy advisors via five case studies of potential emerging diseases of cattle. Tasks for model validation included describing the path taken in the algorithm and stating an outcome. Twenty-nine per cent of the 62 experts commented on the model, and one-third of those responding also completed the tasks required for model validation. The feedback from the panel of experts and the review group was used to further develop the tool and remove redundancies and ambiguities. There was agreement in the pathways and assessments for diseases in which the causative agent was well understood (for example, bovine pneumonia due to Mycoplasma bovis). The stated pathways and assessments of other diseases (for example, bovine Johne's disease) were not as consistent. The framework helps to promote objectivity by requiring questions to be answered sequentially and providing the opportunity to record consensus or differences of opinion. Areas for discussion and future investigation are highlighted by the points of diversion on the pathway taken by different assessors.

Rational design of novel, potent piperazinone and imidazolidinone BACE1 inhibitors.

Guided by structure-based design, we synthesized two novel series of potent inhibitors of BACE1 and generated extensive SAR around both the prime and non-prime side binding pockets. The key feature of both series is a cyclic amine motif specifically crafted to achieve interactions with both the flap and with the S2' pocket.

An extended outbreak of congenital chondrodysplasia in calves in South East Australia.

OBJECTIVE: To report an outbreak of congenital chondrodystrophy in calves in South East Australia. METHODS: District veterinarians investigated reported cases of calf deformities. Owners of affected herds were interviewed using a standard questionnaire to identify potential risk factors. Dams of several affected calves were serologically tested for Akabane virus, Aino virus, pestivirus and bluetongue, and affected calves were tested for pestivirus antigen and serum immunoglobulin concentrations. Gross and histopathological examinations of numerous calves were performed, concentrating on the musculoskeletal system. RESULTS: A case definition of distinctive skeletal deformities was established, and 89 property owners reported calves with chondrodystrophy in Spring 2003, 2004 or 2005. Some 14 property owners reported affected calves in more than one year. Prevalence and severity of deformity varied greatly between and within properties. None of breed, sex, age of dam, lineage, pasture type, supplementary feeding, fertiliser use or toxic plants was consistently associated with the disease. All dams experienced hot, dry conditions during the first trimester of pregnancy and were exposed to adverse conditions thereafter. Consistently dams were reported to have been grazing undulating to hilly terrain during early pregnancy. All serological tests were negative for Akabane virus, Aino virus, pestivirus and bluetongue. Histopathology of affected skeletal samples showed chondrodysplasia. CONCLUSION: The outbreak had similarities with previous outbreaks reported in the region. No specific aetiology could be determined. There is some evidence that the cause of the deformities could be a manganese deficiency during foetal development. Ongoing work to test this hypothesis is therefore warranted.

Discovery of an orally efficaceous 4-phenoxypyrrolidine-based BACE-1 inhibitor.

Based on a lead compound identified from the patent literature, we developed patentably novel BACE-1 inhibitors by introducing a cyclic amine scaffold as embodied by 1a and 1b. Extensive SAR studies assessed a variety of isophthalamide replacements including substituted pyrrolidinones and ultimately led to the identification of 11. Due to its favorable overall profile, 11 has been extensively profiled in various in vivo settings.

Potent pyrrolidine- and piperidine-based BACE-1 inhibitors.

Based on lead compound 1 identified from the patent literature, we developed novel patentable BACE-1 inhibitors by introducing a cyclic amine scaffold. Extensive SAR studies on both pyrrolidines and piperidines ultimately led to inhibitor 2f, one of the most potent inhibitors synthesized to date.

Chondrodysplastic calves in Northeast Victoria.

Outbreaks of chondrodysplasia in calves occur sporadically every 10-15 years, particularly following prolonged drought conditions, throughout Northeastern Victoria and the Southern Tablelands of New South Wales, Australia. An outbreak spanning 2 calving seasons (2003-2004) involving numerous losses through stillbirth, perinatal loss, and poor growth was investigated. Investigations of 4 representative cases are presented here with a definition of the gross and histopathologic defects and an overview of epidemiologic data gathered from affected farms. Calves showed variable disproportionate dwarfism without arthrogryposis. Long bones were shortened and showed axial rotation. Articular surfaces were distorted with misshapen weight-bearing surfaces associated with variable thickness of articular cartilage. Physes were distorted and variable in thickness with occasional foci of complete closure. The major histologic abnormality in the physes was disorderly development of the zones of cartilage hypertrophy, with reduced number and irregular arrangement of hypertrophic chondrocytes; similar less severe changes were present in the zones of cartilage proliferation. Histochemical staining of the cartilage matrix was variable in intensity, and there was evidence of abnormal resorption of cartilage matrix at the level of the primary spongiosa. Osteoid formation and subsequent bone remodelling seemed unaffected, and diaphyseal cortical bone appeared normal at the gross and light microscopic level. No infectious agents were identified, and other known causes for chondrodysplasia in calves were excluded. The most likely cause for the syndrome was considered to be congenital manganese deficiency. Further surveys of tissue and blood manganese levels from cows and calves with and without clinical signs from the region are planned.

Comparison of the V1b antagonist, SSR149415, and the CRF1 antagonist, CP-154,526, in rodent models of anxiety and depression.

Vasopressin and corticotropin releasing factor (CRF) are both critical regulators of an animal's stress response and have been linked to anxiety and depression. As such, antagonists of the CRF1 and V1b receptor subtypes are being developed as potential treatments for affective disorders. The two most characterized V1b and CRF1 antagonists are SSR149415 and CP-154,526, respectively, and the present studies were designed to compare these two compounds in acute animal models of affective disorders. We employed five anxiety models: Separation-induced pup vocalizations (guinea pig and rat), elevated plus-maze (EPM), conditioned lick suppression (CLS), and marble burying (mouse); as well as three depression models: forced swim test (FST; mouse and rat) and tail suspension test (TST; mouse). SSR149415 (1-30 mg/kg) was active in the vocalization, EPM and CLS models, but inactive in marble burying. CP-154,526 (1-30 mg/kg) was active in vocalization models, but inactive in EPM, CLS, and marble burying. SSR149415 was inactive in all depression models; CP-154,526 was active in rat FST but inactive in mouse models. This work demonstrates the different profiles of V1b and CRF1 receptor antagonists and supports both approaches in the treatment of affective disorders.

Characterization of the nociceptin receptor (ORL-1) agonist, Ro64-6198, in tests of anxiety across multiple species.

RATIONALE: Previous studies have demonstrated behaviors indicative of anxiolysis in rats pretreated with the nociceptin receptor (opioid receptor like-1, ORL-1) agonist, Ro64-6198. OBJECTIVES: The aim of this study was to examine the effects of Ro64-6198 in anxiety models across three species: rat, guinea pig, and mouse. In addition, the receptor specificity of Ro64-6198 was studied, using the ORL-1 receptor antagonist, J-113397, and ORL-1 receptor knockout (KO) mice. Finally, neurological studies examined potential side effects of Ro64-6198 in the rat and mouse. RESULTS: Ro64-6198 (3-10 mg/kg) increased punished responding in a rat conditioned lick suppression test similarly to chlordiazepoxide (6 mg/kg). This effect of Ro64-6198 was attenuated by J-113397 (10 mg/kg), but not the mu opioid antagonist, naltrexone (3 mg/kg). In addition, Ro64-6198 (1-3 mg/kg) reduced isolation-induced vocalizations in rat and guinea pig pups. Ro64-6198 (3 mg/kg) increased the proportion of punished responding in a mouse Geller-Seifter test in wild-type (WT) but not ORL-1 KO mice, whereas diazepam (1-5.6 mg/kg) was effective in both genotypes. In rats, Ro64-6198 reduced locomotor activity (LMA) and body temperature and impaired rotarod, beam walking, and fixed-ratio (FR) performance at doses of 10-30 mg/kg, i.e., three to ten times higher than an anxiolytic dose. In WT mice, Ro64-6198 (3-10 mg/kg) reduced LMA and rotarod performance, body temperature, and FR responding, but these same measures were unaffected in ORL-1 KO mice. Haloperidol (0.3-3 mg/kg) reduced these measures to a similar extent in both genotypes. These studies confirm the potent, ORL-1 receptor-mediated, anxiolytic-like effects of Ro64-6198, extending the findings across three species. Ro64-6198 has target-based side effects, although the magnitude of these effects varies across species.

Central melanocortin system modulates energy intake and expenditure of obese and lean Zucker rats.

Melanocortins play a critical role in appetite and body weight regulation, because manipulations of this pathway can lead to the development of obesity in several animal models. The purpose of this study was to use a melanocortin receptor agonist and antagonist to evaluate the involvement of melanocortins in feeding, energy metabolism, and body weight regulation in lean and obese Zucker rats. Central administration of a melanocortin receptor antagonist (SHU9119) elevated food intake and body weight of lean Zucker rats but had little effect in obese Zucker rats. In contrast, the melanocortin receptor agonist MTII reduced food intake in both lean and obese rats but was more potent in the obese Zucker rats. These data indicate the existence of functional melanocortin receptors in both lean and obese Zucker rats but suggest that obese Zucker rats have reduced endogenous melanocortin tone. In addition to its effects on food intake, MTII infusion elevated oxygen consumption and decreased respiratory quotient dose dependently during the light cycle. Our data suggest that a melanocortin receptor agonist can induce weight loss by increasing energy expenditure and promoting body fat utilization in addition to its inhibitory effects on food intake in both obese and lean Zucker rats.

GP2, a GPI-anchored protein in the apical plasma membrane of the pancreatic acinar cell, co-immunoprecipitates with src kinases and caveolin.

We previously showed that endocytosis at the apical plasma membrane (APM) of the pancreatic acinar cell is activated by the cleavage of GP2, a GPI-linked protein, from the apical cell surface. This endocytic process, as measured by horseradish peroxidase uptake into pancreatic acinar cells, is blocked by the tyrosine kinase inhibitors genistein and tyrphostin B42 as well as by disruption of actin filaments with cytochalasin. This suggests that the cleavage of GP2 from the cell membrane may activate endocytosis through a tyrosine kinase-regulated pathway. However, the mechanism by which GP2 and tyrosine kinases act together to activate endocytosis at the APM remains unknown. In this study, we demonstrate that pp60, p62yes, caveolin, and annexin, which have previously been implicated in endocytosis in other cell lines, were present in high abundance in GPI-enriched membranes by Western blot analysis. pp60, p62yes, and caveolin all co-immunoprecipitated with GP2 except annexin. An 85-kDa protein whose tyrosine-dependent phosphorylation is correlated with the activation of endocytosis in intact acinar cells also was present in these immunoprecipitates. This suggests that in pancreatic acini, GP2 may exist in a complex with src kinases, caveolin, and an 85-kDa phosphorylated substrate to regulate endocytosis at the APM.

Rapamycin, but not FK506 and GPI-1046, increases neurite outgrowth in PC12 cells by inhibiting cell cycle progression.

Immunophilin ligands such as rapamycin, FK506 and GPI-1046 have been reported to increase neurite outgrowth in vitro and to have neuroprotective activity in vitro and in vivo. In this study, however, FK506 and GPI-1046 (0.1-1000 nM) had little effect on neurite outgrowth in PC12 cells in either the presence or absence of nerve growth factor. In contrast, rapamycin markedly increased neurite outgrowth in PC12 cells in the presence of a low concentration of nerve growth factor (EC(50)=10 nM). Unlike FK506 and GPI-1046, rapamycin is an inhibitor of cell cycle progression. Other cell cycle inhibitors such as ciclopirox and flavopiridol also increased neurite outgrowth in PC12 cells in the presence of a low concentration of nerve growth factor (EC(50)=250 nM and 100 nM, respectively). The neuroprotective effects of FK506, rapamycin and GPI-1046 were also tested in a rodent model of permanent focal cerebral ischemia. FK506 and rapamycin decreased infarct volume by 40% and 37%, respectively, whereas GPI-1046 was ineffective. These data do not support the previous suggestion that FK506 and GPI-1046 increase neurite outgrowth of PC12 cells in vitro. Rapamycin increases neurite outgrowth of PC12 cells, an effect that can be ascribed to its ability to inhibit cell cycle progression. The neuroprotective effect of FK506 and rapamycin against cerebral ischemia is probably not due to differentiation of neuronal precursors or stimulation of neuronal regeneration.

Pharmacological characterization of the cloned neuropeptide Y y(6) receptor.

Neuropeptide Y has potent appetite stimulating effects which are mediated by hypothalamic receptors believed to be of the neuropeptide Y Y(1) and/or neuropeptide Y Y(5) subtype. In mice, the neuropeptide Y y(6) receptor is also expressed in the hypothalamus, suggesting that it too may function as a feeding receptor in this species. Several laboratories have studied the pharmacology of the neuropeptide Y y(6) receptor, but their results are not in agreement. Using neuropeptide Y and a variety of peptide analogs and small molecule antagonists, we have determined that the pharmacology of the cloned mouse neuropeptide Y y(6) receptor is distinct from that of the other known neuropeptide Y receptors. The rank order of binding affinity for the mouse neuropeptide Y y(6) receptor is [(Ile, Glu,Pro,Dpr,Tyr,Arg,Leu,Arg,Tyr-NH(2))(2)human peptide YY=human, rat neuropeptide Y=human, rat neuropeptide Y-(2-36)=human, rat [Leu(31), Pro(34)porcine (Cys(2))-neuropeptide Y-(1-4)-8-aminooctanoyl-(D-Cys(27)porcine [D-Trp(32)rat pancreatic polypeptide=human pancreatic polypeptide. A similar rank order of potency is seen for inhibition of forskolin-stimulated cyclic AMP. The neuropeptide Y Y(5) receptor antagonist trans-naphthalene-1-sulfonic acid ¿4-[4-amino-quinazolin-2-ylamino)-methyl]-cyclohexylmethy l¿-amide hydrochloride (CGP 71683A) and the neuropeptide Y Y(1) receptor antagonist ((R)-N(2)-diphenylacetyl)-N-[(4-hydroxyphenyl)methyl]-argininam ide) (BIBP3226) bind weakly to the neuropeptide Y y(6) receptor (K(i)10, 000 nM, respectively). Although the function of the neuropeptide Y y(6) receptor remains to be elucidated, its pharmacology is not consistent with a role in appetite regulation.

[D-Trp(34)] neuropeptide Y is a potent and selective neuropeptide Y Y(5) receptor agonist with dramatic effects on food intake.

The neuropeptide Y (NPY) Y(5) receptor has been proposed to mediate several physiological effects of NPY, including the potent orexigenic activity of the peptide. However, the lack of selective NPY Y(5) receptor ligands limits the characterization of the physiological roles of this receptor. Screening of several analogs of NPY revealed that [D-Trp(34)]NPY is a potent and selective NPY Y(5) receptor agonist. Unlike the prototype selective NPY Y(5) receptor agonist [D-Trp(32)]NPY, [D-Trp(34)]NPY markedly increases food intake in rats, an effect that is blocked by the selective NPY Y(5) receptor antagonist CGP 71683A. These data demonstrate that [D-Trp(34)]NPY is a useful tool for studies aimed at determining the physiological roles of the NPY Y(5) receptor.

A membrane lipid imbalance plays a role in the phenotypic expression of cystic fibrosis in cftr(-/-) mice.

A deficiency in essential fatty acid metabolism has been reported in plasma from patients with cystic fibrosis (CF). However, its etiology and role in the expression of disease is unknown. The objective of this study was to determine whether alterations in fatty acid metabolism are specific to CF-regulated organs and whether they play a role in the expression of disease. A membrane lipid imbalance was found in ileum, pancreas, and lung from cftr(-/-) mice characterized by an increase in phospholipid-bound arachidonic acid and a decrease in phospholipid-bound docosahexaenoic acid (DHA). This lipid imbalance was observed in organs pathologically affected by CF including lung, pancreas, and ileum and was not secondary to impaired intestinal absorption or hepatic biosynthesis of DHA. As proof of concept, oral administration of DHA to cftr(-/-) mice corrected this lipid imbalance and reversed the observed pathological manifestations. These results strongly suggest that certain phenotypic manifestations of CF may result from remediable alterations in phospholipid-bound arachidonic acid and DHA levels.