The impact of changing the cut-off threshold of the interferon-gamma (IFN-γ) assay for diagnosing bovine tuberculosis in Ireland

In Ireland, the interferon-gamma (IFN-γ) assay is routinely used as an ancillary test interpreted in parallel with the single intradermal comparative tuberculin test (SICTT) to maximize the detection of bovine tuberculosis (bTB) infected animals. Up until 2018, a positive test result was recorded in the IFN-γ ELISA assay following whole blood stimulation with purified protein derivative (PPD)-bovine (B), PPD-avian (A) and nil sample (N), using the interpretation criteria, B-N > 50 optical density units (OD), B > 100 and B-A > 0. Following a review of available data, the threshold of the B-A component changed to B-A > 80. As predicting the impact of changing the cut-off thresholds for the IFN-γ test de novo is challenging, the aims of this study were to follow animals that initially tested negative using the new IFN-γ assay interpretation criteria and investigate their future risk of disclosure with bTB, with a focus on animals that otherwise would have been removed when using the older interpretation criteria (0 < B-A ≤ 80). Enrolled animals (n = 28,669 cattle from 527 herds) were followed up for two years (2019-2021), or to point of bTB detection or death. At the end of follow-up, 1151 (4.0%) of enrolled animals were bTB cases. The majority of these cases were diagnosed using SICTT (80.5%). The cumulative number of positive animals that would have been removed if the old cut-off (0 < B-A ≤ 80) was used amounted to 1680 cattle (5.9% of the enrolled cohort). Of these, 127 (7.5%) were diagnosed with bTB during follow-up. In contrast, 1024 of the 1151 cattle which subsequently tested positive during the study period following a negative IFN-γ test would not have been identified with the old or new IFN-γ cut-off criteria. Survival analysis showed that animals that would have been removed under the old interpretation criteria were at increased risk of a positive diagnosis with bTB during follow-up compared to other test negative animals. A newly developed risk prediction model (using a Cox proportional hazard model) showed that age, animal number of SICTT tests, number of inconclusive SICTT tests, B-A (IFN-γ assay), B-N (IFN-γ assay), animals from store herds and the percentage of the rest of the herd that were positive during the breakdown were statistically significantly associated with bTB detection. However, inclusion of the IFN-γ OD variables did not show added value in terms of prediction performance of the model.

Whole-Genome sequencing in routine Mycobacterium bovis epidemiology - scoping the potential

Mycobacterium bovis the main agent of bovine tuberculosis (bTB), presents as a series of spatially-localised micro-epidemics across landscapes. Classical molecular typing methods applied to these micro-epidemics, based on genotyping a few variable loci, have significantly improved our understanding of potential epidemiological links between outbreaks. However, they have limited utility owing to low resolution. Conversely, whole-genome sequencing (WGS) provides the highest resolution data available for molecular epidemiology, producing richer outbreak tracing, insights into phylogeography and epidemic evolutionary history. We illustrate these advantages by focusing on a common single lineage of M. bovis (1.140) from Northern Ireland. Specifically, we investigate the spatial sub-structure of 20 years of herd-level multi locus VNTR analysis (MLVA) surveillance data and WGS data from a down sampled subset of isolates of this MLVA type over the same time frame. We mapped 2108 isolate locations of MLVA type 1.140 over the years 2000-2022. We also mapped the locations of 148 contemporary WGS isolates from this lineage, over a similar geographic range, stratifying by single nucleotide polymorphism (SNP) relatedness cut-offs of 15 SNPs. We determined a putative core range for the 1.140 MLVA type and SNP-defined sequence clusters using a 50 % kernel density estimate, using cattle movement data to inform on likely sources of WGS isolates found outside of core ranges. Finally, we applied Bayesian phylogenetic methods to investigate past population history and reproductive number of the 1.140 M. bovis lineage. We demonstrate that WGS SNP-defined clusters exhibit smaller core ranges than the established MLVA type - facilitating superior disease tracing. We also demonstrate the superior functionality of WGS data in determining how this lineage was disseminated across the landscape, likely via cattle movement and to infer how its effective population size and reproductive number has been in flux since its emergence. These initial findings highlight the potential of WGS data for routine monitoring of bTB outbreaks.

Pilot testing the EARS-Vet surveillance network for antibiotic resistance in bacterial pathogens from animals in the EU/EEA

Introduction

As part of the EU Joint Action on Antimicrobial Resistance (AMR) and Healthcare-Associated Infections, an initiative has been launched to build the European AMR Surveillance network in veterinary medicine (EARS-Vet). So far, activities included mapping national systems for AMR surveillance in animal bacterial pathogens, and defining the EARS-Vet objectives, scope, and standards. Drawing on these milestones, this study aimed to pilot test EARS-Vet surveillance, namely to (i) assess available data, (ii) perform cross-country analyses, and (iii) identify potential challenges and develop recommendations to improve future data collection and analysis.

Methods

Eleven partners from nine EU/EEA countries participated and shared available data for the period 2016-2020, representing a total of 140,110 bacterial isolates and 1,302,389 entries (isolate-antibiotic agent combinations).

Results

Collected data were highly diverse and fragmented. Using a standardized approach and interpretation with epidemiological cut-offs, we were able to jointly analyze AMR trends of 53 combinations of animal host-bacteria-antibiotic categories of interest to EARS-Vet. This work demonstrated substantial variations of resistance levels, both among and within countries (e.g., between animal host species).

Discussion

Key issues at this stage include the lack of harmonization of antimicrobial susceptibility testing methods used in European surveillance systems and veterinary diagnostic laboratories, the absence of interpretation criteria for many bacteria-antibiotic combinations of interest, and the lack of data from a lot of EU/EEA countries where little or even surveillance currently exists. Still, this pilot study provides a proof-of-concept of what EARS-Vet can achieve. Results form an important basis to shape future systematic data collection and analysis.

Characterization of mechanical properties of soft tissues using sub-microscale tensile testing and 3D-Printed sample holder

Obtaining the mechanical properties of soft tissues is critical in many medical fields, such as regenerative medicine and surgical simulation training. Although various tissue-characterization methods have been developed, such as AFM, indentation, and elastography, there remain some limitations on their accuracy and validity for measuring small and fragile soft tissues. This paper presents a tensile testing technique to measure the mechanical properties of soft tissues directly and accurately. Tensile testing was chosen as the primary method because of its simple procedure and ability to derive mechanical properties without requiring many assumptions or complicated models. However, tensile testing on soft tissues presents challenges related to gripping the tissue sample without affecting its inherent properties, applying minuscule forces to the sample, and measuring the cross-section area and strain of the sample. To solve these issues, this study presents a sub-micro scale tensile testing system that uses a flexure mechanism and a novel 3D-printed sample holder for gripping the tissue samples. The system also measures tested samples' cross-section area and strain using two high-resolution cameras. The system was validated by testing standard materials and used to characterize the elastic modulus, yield stress, and yield strain of lung tissue slices from six different mice. The results from the validation tests showed a less than 2.5% error for elastic modulus values measured using the tensile tester. At the same time, results from the mice lung tissue measurements revealed qualitative findings that closely matched those seen in the literature and displayed low coefficient of variation values, demonstrating the high repeatability of the system.

Understanding experiences of Aboriginal and/or Torres Strait Islander patients at the emergency departments in Australia

OBJECTIVES

The present study describes the experiences of Aboriginal and/or Torres Strait Islander patients and the factors that shaped their experiences of ED visits in regional settings.

METHODS

This is a qualitative descriptive study. We conducted semi-structured in-depth interviews with Aboriginal and/or Torres Strait Islander patients who used the ED services at three hospitals in New South Wales, Northern Territory and South Australia. We coded the collected data and analysed them using a thematic analysis technique.

RESULTS

A total of 33 Aboriginal and/or Torres Strait Islander patients participated. Analyses of their experiences revealed four themes, which included: (i) patients' waiting times in ED; (ii) cultural determinants of health; (iii) treatment services; and (iv) safety, security and privacy.

CONCLUSIONS

A holistic approach and a robust hospital commitment to address cultural needs while considering overall health, social and emotional wellbeing, will enhance Aboriginal and/or Torres Strait Islander patients' satisfaction for ED visits.

People living with HIV have low trabecular bone mineral density, high bone marrow adiposity, and poor trabecular bone microarchitecture at the proximal femur

People living with HIV (PLWH) have increased risk of osteoporosis and fractures. We assessed the proximal femur of PLWH and age-matched seronegative controls using quantitative computed tomography and magnetic resonance imaging. Results suggest that the trabecular compartment is compromised at fracture-prone regions in the proximal femur of PLWH.

INTRODUCTION

People living with HIV (PLWH) have increased risk of osteoporosis and fractures. However, studies assessing the main determinants of bone strength in the proximal femur exclude this vulnerable population. We assessed the proximal femur of 40 PLWH and 26 age-matched seronegative controls using quantitative computed tomography and magnetic resonance imaging.

METHODS

We examined cortical volumetric bone mineral density (Ct.vBMD), trabecular vBMD (Tb.vBMD), cortical thickness (Ct.Th), bone marrow adiposity (BMA), and trabecular number, separation, and bone volume fraction. Parametric comparisons between the two groups were made for the femoral head, femoral neck, trochanter, and total hip using linear regression adjusting for several covariates, including metrics of body composition. In addition, we investigated the associations of BMA with Tb.vBMD and trabecular microarchitecture with Spearman's rank partial correlations.

RESULTS

PLWH had lower Tb.vBMD and deteriorated trabecular microarchitecture in the femoral neck, trochanter and total hip, and elevated BMA in the femoral head, femoral neck, and total hip. Ct.vBMD and Ct.Th were not significantly different between the two groups. BMA was significantly associated with lower Tb.vBMD and deteriorated trabecular microarchitecture in both groups albeit at different femoral regions.

CONCLUSIONS

Our findings suggest that the trabecular, and not the cortical, compartment is compromised in the proximal femur of PLWH. The observed impairments in fracture-prone regions in PLWH indicate lower femoral strength and suggest higher fracture risk. The inverse associations of BMA with trabecular bone density and microarchitecture quality agree with findings at other anatomic sites and in other populations, suggesting that excess BMA possibly due to a switch from the osteoblast to the adipocyte lineage may be implicated in the pathogenesis of bone fragility at the femur in PLWH.

Protective immunity against tuberculosis in a free-living badger population vaccinated orally with Mycobacterium bovis Bacille Calmette-Guérin

Vaccination of badgers with Mycobacterium bovis Bacille Calmette-Guérin (BCG) has been shown to protect badgers against tuberculosis in experimental trials. During the 3-year County Kilkenny BCG vaccine field study, badgers were treated orally with placebo (100% in Zone A), BCG (100% in Zone C) or randomly assigned 50%: 50% treatment with BCG or placebo (Zone B). At the end of the study, 275 badgers were removed from the trial area and subjected to detailed post-mortem examination followed by histology and culture for M. bovis. Among these badgers, 83 (30.2%) were captured for the first time across the three zones, representing a non-treated proportion of the population. Analysis of the data based on the infection status of treated animals showed a prevalence of 52% (95% CI: 40%-63%) infection in Zone A (placebo), 39% (95% CI: 17%-64%) in Zone B (placebo) and 44% (95% CI: 20%-70%) in Zone B (BCG vaccinated) and 24% (95% CI: 14%-36%) in Zone C (BCG vaccinated). There were no statistically significant differences in the proportion of animals with infection involving the lung and thoracic lymph nodes, extra-thoracic infection or in the distribution and severity scores of histological lesions. Among the 83 non-treated badgers removed at the end of the study, the infection prevalence of animals in Zone A (prevalence = 46%, 95% CI: 32%-61%) and Zone B (prevalence = 44%, 95% CI: 23%-67%) was similar to the treated animals in these zones. However, in Zone C, no evidence of infection was found in any of the untreated badgers (prevalence = 0%, 95% CI: 0%-14%). This is consistent with an indirect protective effect in the non-vaccinated badgers leading to a high level of population immunity. The results suggest that BCG vaccination of badgers could be a highly effective means of reducing the incidence of tuberculosis in badger populations.

Mycobacterium bovis BCG Danish Strain 1331 isolated from a periarticular lesion in a domestic cat

A 7-year-old male neutered domestic shorthair outdoor cat was referred for chronic left forelimb lameness, which had been treated with intra-articular injections of triamcinolone acetonide. A soft tissue swelling around the elbow joint, extending from the distal humerus to the proximal ulna, was surgically explored and biopsy samples obtained. Mycobacterium bovis was cultured from samples from the soft tissue and bone. The mycobacteria from the media were killed and the DNA extracted and tested on a multiplex real-time PCR for the absence of specific genes and the presence of mycobacterial genus markers. The PCR revealed bacillus Calmette-Guérin Danish Strain 1331; this was also isolated from the prescapular lymph node, muscle and bone, obtained at post mortem examination. Badgers had been vaccinated with the bacillus Calmette-Guérin vaccine SSI (Statens Serum Institute) in the area where the cat lived, in the spring and autumn of the previous year. To the authors' knowledge, this is the first report of infection with M. bovis bacillus Calmette-Guérin Danish Strain 1331 in a domestic cat, potentially associated with annual vaccination of badgers in the proximity of the cat's home.

Mycobacterium bovis genomics reveals transmission of infection between cattle and deer in Ireland

Control of bovine tuberculosis (bTB), caused by Mycobacterium bovis, in the Republic of Ireland costs €84 million each year. Badgers are recognized as being a wildlife source for M. bovis infection of cattle. Deer are thought to act as spillover hosts for infection; however, population density is recognized as an important driver in shifting their epidemiological role, and deer populations across the country have been increasing in density and range. County Wicklow represents one specific area in the Republic of Ireland with a high density of deer that has had consistently high bTB prevalence for over a decade, despite control operations in both cattle and badgers. Our research used whole-genome sequencing of M. bovis sourced from infected cattle, deer and badgers in County Wicklow to evaluate whether the epidemiological role of deer could have shifted from spillover host to source. Our analyses reveal that cattle and deer share highly similar M. bovis strains, suggesting that transmission between these species is occurring in the area. In addition, the high level of diversity observed in the sampled deer population suggests deer may be acting as a source of infection for local cattle populations. These findings have important implications for the control and ultimate eradication of bTB in Ireland.

Individual and herd-level milk ELISA test status for Johne's disease in Ireland after correcting for non-disease-associated variables

Antibody-detecting tests for Mycobacterium avium ssp. paratuberculosis (MAP) have low sensitivity and imperfect specificity for detection of infection. Sensitivity increases as the disease progresses. Aside from infection status and stage of disease, several factors affect test performance. These factors have not yet been studied in dairy cows producing lower volumes of milk with higher solids concentration, such as those managed in low-input, pasture-based production systems. Furthermore, the effect of correcting for these associations on individual and herd test status is also unknown. The first objective of this study was to examine the relationship between MAP antibody response in milk and milk yield, somatic cell count (SCC), fat and protein contents, and stage of lactation in dairy cows enrolled in the national Johne's Disease Control Programme (JDCP) in Ireland. The second objective was to examine the effect of correcting the antibody response for these associations on the test status of individual cows and herds, given that individual tests are often used to define a herd's status. Data were extracted for herds in the JDCP from January 2014 to December 2015 inclusive, consisting of 42,657 milk recordings from 18,569 cows across 187 dairy herds. Two linear regression models were constructed to investigate the association between log-transformed MAP sample-to-positive ratio and milk recording data and in primi- and multiparous cows. Days in milk was modeled as a B-spline in each model, and cow and herd were included as random effects. Across both models, natural log-transformed MAP antibody response was negatively associated with milk yield, positively associated with protein and fat production, and had a curvilinear association with log-transformed SCC. The association between MAP antibody response and days in milk varied over the course of the lactation. However, when combined, these variables explained only 5.1% of the variation in the antibody response of the population. After correcting for these associations, 93 multiparous cows and 20 primiparous cows changed category (negative, suspect, or positive). When considered at the herd-test level, out of a total of 531 herd tests, 1 herd changed from negative to positive, and 5 herds changed from positive to negative. This study provides useful information to aid in the interpretation of antibody results for herds testing animals for the presence of MAP infection. At an overall population level, correction of the serological response for non-disease-associated factors has the potential to change the status of only a small number of cows. At the herd level, the proportion of herds changing status was minimal. However, depending on the implications of a herd-level serological diagnosis, consideration should be given to correcting for these non-disease-associated variables within the context of national JD control programs.

Identification of microRNAs in bovine faeces and their potential as biomarkers of Johne's Disease

Extracellular microRNAs (miRNAs) are detectable in the peripheral blood and have been touted as potential biomarkers for a range of maladies. The presence and biomarker potential of miRNAs in other biofluids has been less thoroughly explored, particularly in the veterinary realm. Faecal miRNAs are a case in point; while they have been identified largely in rodents and humans, they have not been reported in cattle but may have prognostic or diagnostic value for Johne's Disease (JD) in cattle, a chronic granulomatous inflammation of the ileum caused by Mycobacterium avium subspecies paratuberculosis (MAP). The aim of this study was thus to characterise the bovine faecal miRNome and to determine the utility of these transcripts as biomarkers for JD. Real-time PCR arrays consisting of 752 miRNA targets, optimised for detection of human miRNA, were used to screen RNA purified from faecal samples obtained from confirmed JD clinical cases vs. healthy controls. Two hundred and fifty-eight miRNAs were detected in bovine faeces, three of which are potentially novel orthologs of known human miRNAs. Differential abundance of three miRNA was evident in animals with clinical JD as compared to healthy controls. Our study has therefore identified a variety of miRNAs in bovine faeces and has demonstrated their utility in differentiating healthy animals from those with late-stage JD, providing potential biomarkers for MAP infection and disease progression.

Tuberculin PPD Potency Assays in Naturally Infected Tuberculous Cattle as a Quality Control Measure in the Irish Bovine Tuberculosis Eradication Programme

The Irish Bovine Tuberculosis (bTB) eradication programme operates under national legislation and fulfills OIE and EU trade requirements. Tuberculin purified protein derivative (PPD), a preparation obtained from the heat-treated products of growth and lysis of Mycobacterium bovis or Mycobacterium avium (as appropriate), is critical to the diagnosis of tuberculosis (TB). Standardization of Tuberculin PPD potency, the relative activity in sensitized animals compared to a reference standard, is essential to underpin the reliability of certification for international trade and to ensure that disease eradication programmes are effective and efficient. A Bovine International Standard Tuberculin PPD (BIS) was established by the WHO in 1986 and is used to determine comparative potencies of Tuberculin PPDs. Ideally, Tuberculin PPD potency should be evaluated in the species in which the tuberculin will be used but due to practical difficulties in performing potency assays in cattle, for routine PPD production, they are usually assayed in guinea pigs. Low potency tuberculin PPD is less efficient and thus inferior for bTB diagnosis. Difficulties experienced in the Irish bTB eradication programme have included the supply of sub-standard potency, and thus inferior, bovine (M. bovis) Tuberculin PPD in the late 1970s. The purpose of this paper is to outline the critical role of Tuberculin PPD assays carried out on naturally infected tuberculous cattle, as required by the OIE and under EU legislation in the quality control for the Irish Bovine Eradication Programme. Such assays ensure that the Tuberculin PPD used meets the diagnostic sensitivity and specificity requirements to underpin a successful national eradication programme.

A prospective clinical study of regenerative endodontic treatment of traumatized immature teeth with necrotic pulps using bi-antibiotic paste

AIM

To evaluate the treatment outcomes of a revitalization endodontic technique (RET) for the management of traumatized immature teeth with necrotic pulps in children.

METHODOLOGY

Fifteen healthy children (age range = 7-10 years) with traumatized immature maxillary incisors with necrotic pulps treated with bi-antibiotic revitalization endodontic technique were prospectively assessed over approximately two years (mean = 22 months). One operator undertook all treatments, clinical reviews and standardized radiographic exposures with radiographic analysis being carried out by two calibrated experienced clinicians. Crown colour change was assessed using an objective published methodology. Wilcoxon signed-rank test was used to compare root lengths, root dentinal widths and apical foramen widths over time.

RESULTS

Interoperator measurement reliability was consistently strong for all measurements. There was no significant difference in root lengths or root dentinal wall widths following RET. A significant difference in apical foramen widths was observed after 2 years (P = 0.013) with resolution of clinical signs of infection in all cases. Despite omitting minocycline and using Portland cement (nonbismuth containing cement), a noticeable crown colour change (yellower, redder and lighter), as measured by an objective colour measurement system with ΔE = 7.39, was recorded. Most patients, however, were satisfied with the aesthetic outcome.

CONCLUSION

Traumatized immature teeth with necrotic pulps treated with revitalization endodontic technique did not demonstrate continuation of root development or dentine formation when assessed by periapical radiographs. However, apical closure and periodontal healing were observed. A measurable change in crown colour (yellower, redder and lighter), with mostly no aesthetic concern to the patients/parents, was also observed.

Evaluation of testing strategies to identify infected animals at a single round of testing within dairy herds known to be infected with Mycobacterium avium ssp. paratuberculosis

As part of a broader control strategy within herds known to be infected with Mycobacterium avium ssp. paratuberculosis (MAP), individual animal testing is generally conducted to identify infected animals for action, usually culling. Opportunities are now available to quantitatively compare different testing strategies (combinations of tests) in known infected herds. This study evaluates the effectiveness, cost, and cost-effectiveness of different testing strategies to identify infected animals at a single round of testing within dairy herds known to be MAP infected. A model was developed, taking account of both within-herd infection dynamics and test performance, to simulate the use of different tests at a single round of testing in a known infected herd. Model inputs included the number of animals at different stages of infection, the sensitivity and specificity of each test, and the costs of testing and culling. Testing strategies included either milk or serum ELISA alone or with fecal culture in series. Model outputs included effectiveness (detection fraction, the proportion of truly infected animals in the herd that are successfully detected by the testing strategy), cost, and cost-effectiveness (testing cost per true positive detected, total cost per true positive detected). Several assumptions were made: MAP was introduced with a single animal and no management interventions were implemented to limit within-herd transmission of MAP before this test. In medium herds, between 7 and 26% of infected animals are detected at a single round of testing, the former using the milk ELISA and fecal culture in series 5 yr after MAP introduction and the latter using fecal culture alone 15 yr after MAP introduction. The combined costs of testing and culling at a single round of testing increases with time since introduction of MAP infection, with culling costs being much greater than testing costs. The cost-effectiveness of testing varied by testing strategy. It was also greater at 5 yr, compared with 10 or 15 yr, since MAP introduction, highlighting the importance of early detection. Future work is needed to evaluate these testing strategies in subsequent rounds of testing as well as accounting for different herd dynamics and different levels of herd biocontainment.

Multiplexed IHC analysis to enable Hodgkin lymphoma differential diagnosis on a single slide

e19536

Background: Routine diagnosis of classical Hodgkin lymphoma is performed with a panel of immunohistochemistry markers to evaluate the biomarker expression profile of the relatively rare Hodgkin cells. One of the key challenges of this technique is that serial immunostains are used and hence it can be difficult or impossible to locate the same Hodgkin cell on adjacent slides. Given the rarity of the Hodgkin cells coupled with the number of markers that are needed for a definitive diagnosis, we developed a new technique in which a single patient slide is multiplexed with nine different antibodies . Methods: One FFPE tissue section from 11 cases was probed for the following nine biomarkers: CD30, CD15, CD45, Pax5, CD20, CD79a, OCT2, Bob1, and CD3. An initial 10x whole slide fluorescent image of CD30 was acquired and presented to the pathologist who based on this staining selected regions of interest for higher magnification (40x) imaging of the CD30 and the other antibodies. The fluorescent images acquired were processed for interpretation using an in-house developed viewing tool. The pathologist was able to view each biomarker as a standard grayscale, monochromatic image, an overlay of two or more biomarkers, or as a virtually created molecular DAB image. Results: A correct diagnosis of classical Hodgkin lymphoma vs. other was able to be made using the MultiOmyx platform in all cases. Subjectively, the pathologist noted that the novel methodology allowed for a significantly more confident assessment of marker expression on the Hodgkin cells in the seven cases of classical Hodgkin lymphoma, eliminating many issues of staining ambiguity and allowing recognition of subtle nuances of staining intensity in the Hodgkin cells. The CD30+ cells in the four other cases, three cases of B-cell lymphoma and one case of lymphocyte predominance Hodgkin lymphoma, showed a B-cell profile that was distinguishable from the classical Hodgkin cell phenotype. Conclusions: This new method of fluorescent multiplexing on a single tissue section allows more accurate interpretation of the biomarker expression profile on the same Hodgkin cell. It is likely that this paradigm can be expanded to a greater range of challenging cases in hematopathology.

Abstract P3-05-05: HER2 Expression and Gene copy analysis by Immunofluorescence and Fluorescence in situ Hybridization, on a Single formalin-fixed paraffin-embedded tissue section

Introduction: Breast cancer is the most common cancer for women worldwide. HER2 expression and gene copy number are important when determining eligibility for adjuvant therapy and/or chemotherapy medications. One challenging issue for breast cancer testing is intratumoral heterogeneity of HER2 gene amplification. Intratumoral heterogeneity can make it difficult to localize target cells of interest. Serial tissue sections used for independent H&E, IHC and FISH stains also increase the difficulty to localize targets due to cellular truncation. We have developed a system to assess both HER2 expression and gene copy number on the same cell.

Method: Immunofluorescence (IF) and Fluorescence in situ Hybridization (FISH) were performed on tissue sections from 19 patients with invasive ductal breast carcinoma. Cases were selected based on prior HER2 FISH results (HER2:Chromosome 17 = ratio) representing unamplified (&lt;2.0), amplified (≥2.0) and equivocal (1.8–2.2). Samples were collected from June 2011 – February 2012. Tissue sections were cut at 4uM from formalin-fixed paraffin-embedded tissue blocks. Slides were stained with antibodies for HER2 (Clone #D8F12, Cell Signaling, Danvers, MA), cytokeratin (Clone #AE1, eBioscience, San Diego, CA) and Pan cytokeratin (Clone #PCK-26, Sigma-Aldrich, St. Louis, MO). The whole tissue imaging was performed on the In-Cell (GE Healthcare, Chalfont St. Giles, UK) at 10X. Proprietary software developed by GRC (GE Global Research, Niskayuna, NY) controlled the hardware and performed numerous algorithmic functions. Regions of Interest (ROI) were selected by a pathologist on a whole tissue image and coordinates were recorded by the software. The slides were then imaged at 40x using the previously recorded ROI's. The same slides were stained with the PathVysion HER2/CEP17 FISH kit (Abbott Molecular, Des Plaines, IL). Slides were registered to the previous IF scan using recorded coordinates and tissue morphology recognition algorithms. The sections were imaged for FISH at 40X using the previous ROI selections. Cases were assessed for successful protein and genetic expression using proprietary visualization tools for combined analysis.

Results: We evaluated a total of 22 breast cancer cases with 19 cases detecting both protein and gene expression. Of the three cases that could not be evaluated the rationale is as follows: tissue damage incurred during imaging, insufficient focus during the FISH imaging portion, and poor signal to noise of the FISH dots.

Conclusion: The reported incidence of intratumoral HER2 amplification heterogeneity is as high as 30%. The challenges associated with tumor heterogeneity may benefit from a standardize analysis method. Using integrated images generated by this system, pathologist is able to select the appropriate cells for HER2 copy number enumeration based on the expression level of HER2 protein, in the same cell, allowing rapid identification of intratumoral heterogeneity.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-05-05.

Salmonella in meats, water, fruit and vegetables as disclosed from testing undertaken by Food Business Operators in Ireland from 2005 to 2009

Abstract

Food Business Operators (FBO) are responsible for the safety of the food they produce and in Ireland those under the regulatory control of the Department of Agriculture, Food and Marine are required to provide summary data on microbiological tests undertaken as part of their food safety controls. These data are provided to the National Reference Laboratory through the 25 private laboratories undertaking the testing.

Results

Over the five-year period Salmonella sp. was isolated from 0.7% of the 254,000 raw meat or raw meat products tested with the annual prevalence ranging from 0.5 to 1.1%. Poultry meats were consistently more contaminated than other meats with higher recovery rates in turkey (3.3%), duck (3.3%), and chicken (2.5%) compared with meats of porcine (1.6%), ovine (0.2%) and bovine origin (0.1%). Salmonella sp. was also isolated from 58 (0.06%) of the 96,115 cooked or partially cooked meat and meat products tested during the reporting period with the annual percentage positive samples ranging from 0.01 to 0.16%. A total of 50 different serotypes were recovered from raw meats over this period with the greatest diversity found in poultry samples (n = 36). Four serotypes, Kentucky, Typhimurium, Agona and Derby accounted for over 70% of all isolates detected on FBO testing over the period 2005 to 2009.

Conclusions

Capturing microbiological data generated by Food Business Operators allows the regulatory sector access to a substantial amount of valuable data with the minimum financial outlay.

Use of a multiplex enzyme-linked immunosorbent assay to detect a subpopulation of Mycobacterium bovis-infected animals deemed negative or inconclusive by the single intradermal comparative tuberculin skin test

Although the single intradermal comparative tuberculin skin test (SICTT) remains the most effective assay for detecting cattle infected with Mycobacterium bovis, not all infected animals are detected with the SICTT. This has made it difficult to control bovine tuberculosis using a single assay. Use of the gamma interferon assay in conjunction with the SICTT has improved the level of detection but some infected animals still go undetected. This could be in part attributable to both assays being reliant on a cell-mediated immune response. The present study was undertaken to determine if a multiplex assay can improve the level of detection of infected animals when used in combination with the SICTT. The Enferplex TB assay is a multi-antigen ELISA designed for the detection of antibody in animals at different stages of infection and disease. Sixty cattle that were confirmed by histopathology and/or culture to be infected with M. bovis and that were SICTT negative (43.3%) or difficult to evaluate (56.7% inconclusive) were used in the study. Fifty-three (88.3%) of the animals were positive in multiplex ELISA. The results show that the level of detection of M. bovis-infected animals can be improved by the combined use of the SICTT and the multiplex ELISA.

The use of psychotherapeutic interventions by primary care GPs in Ireland in the treatment of their methadone patients: a grounded theory study

BACKGROUND

The methadone protocol placed responsibility on general practitioners (GPs) for the methadone treatment of stabilised drug-addicted patients. The protocol emphasised a medico-pharmacological model with minor reference to psychotherapeutic treatment.

AIM

This qualitative study investigated how primary care GPs in Ireland use psychotherapeutic interventions in the treatment of methadone patients.

METHOD

A grounded theory methodology was used.

FINDINGS

There is a wide variation in the beliefs and knowledge of methadone-prescribing GPs regarding the efficacy of psychotherapeutic interventions for patients on methadone maintenance. GPs do not formally integrate psychotherapeutic interventions into methadone patient treatment. Accessing psychotherapeutic services raises concerns for GPs in terms of availability, location and quality. Primary care GPs who offer methadone maintenance view opiate abuse as a health issue similar to other such issues within their community. They take a holistic view of their methadone patient and, without formal guidelines, develop individual approaches to the use of psychotherapeutic interventions. The absence of a framework for the use of psychotherapeutic interventions in primary care methadone treatment in Ireland militates against the development of a basis for improving practice.

Rare Bilateral Lipoma of the Internal Auditory Canals

About 10% of all intracranial tumors are localized in the cerebellopontine angle and in the internal auditory canal. Less than 2% of these are lipomas. Furthermore, it can be expected that lipomas in this position with a bilateral localization are exceedingly rare. We describe a 70-year-old-woman with lipomas in both internal auditory canals presented in the literature for the first time and include a detailed literature research.

Antibody response to various single-factor o antigens of salmonella

The relative agglutinin responses to various single O-antigenic (Kauffmann-White) factors were measured after immunization of rabbits with several strains of heat-killed salmonella organisms. As expected, the relative strength of the responses to the various O factors was quite varied and in some cases depended on the presence or absence of other single factors. For example, antibodies to factor 12(2) were formed rapidly and to extremely high levels in rabbits immunized with either Salmonella typhi (O 9,12(1),12(2),12(3)) or S. paratyphi B (O 1,4,5,12(1),12(2)), whereas factor 12(3) in S. typhi and factor 1 in S. paratyphi B induced only minimal responses. However, rabbits immunized with S. paratyphi A var. durazzo (O 2,12(1),12(3)), which lacks factor 12(2), produced high levels of agglutinins to the 12(3) antigenic determinant. In general, most of the agglutinin responses to the various single factors measured were formed in parallel, but there were several exceptions. For instance, the responses to factors 4 and 5 were relatively strong in rabbits receiving three graded doses of S. paratyphi B. However, agglutinins to factor 4 did not appear until after the second injection, and not at all in rabbits given the full amount of antigen in one injection. In contrast, antibodies to factor 4 were formed rapidly in rabbits receiving three graded doses of a strain of S. typhimurium (O 1,4,12) lacking factor 5. Good overall agreement was obtained between agglutination and hemagglutination assays of antibodies, as demonstrated by the responses to the various O factors of S. friedenau. It was concluded that measurement of the antibody responses to the various single-factor O antigens throughout the immunization program was necessary for effective evaluation of the relative significance of these factors in antibody formation against intact bacteria.

An evaluation of Irish cattle herds with inconclusive serological evidence of bovine brucellosis

Since 1998, there has been a steady decline in herd restrictions and de-populations in Ireland due to bovine brucellosis. There is concern that the interpretation of laboratory results may become increasingly problematic, as brucellosis prevalence falls in Ireland. Therefore, the purpose of the current study was to evaluate the infection status of Irish herds and animals with inconclusive serological evidence of bovine brucellosis. During 12 months from September 1, 2004, laboratory and observational epidemiological data were collected from all Irish herds where animal testing identified at least one animal with a complement fixation test (CFT) reading greater than zero and/or a positive result to the indirect enzyme-linked immunosorbent assay (iELISA). Due to the observational nature of the study, we have robust estimates of the relative, but not the absolute, performance of the CFT, iELISA and brucellin skin test (BST). Herds were divided into three categories (Group A, B or C) on the basis of test results at initial assessment. A total of 639 herds were enrolled into the study, and observed for at least two years following enrolment. A rising CFT titre, with a CFT reading of 111 International CFT Units (IU) or greater at the subsequent blood test, was generally associated with herds where other evidence of infection was also available. Knowledge of the CFT reading at the initial and a subsequent blood test proved useful in distinguishing false-positive and true-positive brucellosis results. There was poor correlation between the CFT and iELISA results, and between the CFT and BST results. As a result of this study, national policy has been modified to include re-sampling of all animals with CFT readings of 20 IU or greater. This project has also led to a reduction in the number of herds restricted, as well as restriction duration. It has also contributed to a reduction in the number of herds listed for contiguous tests, and therefore the potential for contiguity testing of false positive results.

Staphylococcus aureus enterotoxin D is secreted in milk and stimulates specific antibody responses in cows in the course of experimental intramammary infection

An enterotoxin D (SED)-producing strain of Staphylococcus aureus was used to infect one mammary gland of each of 17 lactating dairy cows. All glands became infected and shed bacteria over a sampling period of 3 weeks. Serum and milk antibodies specific for SED were monitored by an enzyme-linked immunosorbent assay for 12 weeks. Elevated anti-SED antibodies were detected in all cows after infection, and immunoglobulin of the G2 subclass comprised most of the specific serum response. SED was detected in mastitic milk samples from two cows at levels of 5 to 10 ng/ml. An in vitro lymphocyte proliferation assay showed that SED at levels below 10 pg/ml induced proliferation of bovine lymphocytes and that sheep antiserum specific for SED neutralized this proliferative response. Sera obtained from the cows pre- and postinfection inhibited lymphocyte proliferation at SED concentrations of 10 and 50 ng/ml, respectively. The addition of SED to whole blood or to isolated neutrophils had no significant effect on neutrophil function in vitro. The results show that SED is secreted during mammary gland infection, is mitogenic for bovine lymphocytes, and stimulates the production of specific antibodies.

Enzyme immunoassay for the diagnosis of brucellosis: chimeric Protein A–Protein G as a common enzyme labeled detection reagent for sera for different animal species

A recombinant protein combining the immunoglobulin binding sites of Proteins A and G, conjugated with horseradish peroxidase was used as a universal detection reagent for the assessment of antibodies against Brucella spp. The reagent was applied in an indirect enzyme immunoassay for detection of antibodies to smooth lipopolysaccharide antigen in sera from Brucella spp. exposed and non-exposed cattle, sheep, goats and pigs and to antibodies to rough lipopolysaccharide in sheep, dogs and cattle. The results were similar to those obtained when murine monoclonal antibody-enzyme conjugates were used. An added advantage was that a universal cut-off for all tests using the proteins A and G detection reagent could be established, simplifying diagnostic interpretation of the data.

Rough Lipopolysaccharide ofBrucella abortusRB51 as a Common Antigen for Serological Detection ofB. ovis,B. canis, andB. abortusRB51 Exposure Using Indirect Enzyme Immunoassay and Fluorescence Polarization Assay

Rough lipopolysaccharide (RLPS) antigens were prepared from cultures of Brucella abortus RB51, B. ovis, and B. canis. The preparations were standardized by weight and tested with sera from cattle immunized with B. abortus RB51, sheep infected with B. ovis, and dogs infected with B. canis. Populations of unexposed animals of each species were also tested. The tests used were the indirect enzyme immunoassay (IELISA) using RLPS and the fluorescence polarization assay (FPA) using RLPS core fractions, labeled with fluorescein isothiocyanate. The IELISA using B. abortus RB51 RLPS antigen resulted in sensitivity and specificity values of 94.8% and 97.3%, respectively, when testing bovine sera, 98.5% and 97.8% when testing ovine sera, and 95.8% and 100% when testing dog sera. The IELISA using B. ovis RLPS antigen gave sensitivity and specificity values of 80.5% and 91.7%, respectively with bovine sera, 98.9% and 93.8% with sheep sera, and 70.8% and 79.8% with dog sera. The IELISA using B. canis RLPS antigen resulted in sensitivity and specificity values of 97.0% and 97.4%, respectively, with bovine sera, 96.2% and 96.3% with sheep sera, and 95.8% and 98.8% with dog sera. Labeling RLPS core from B. ovis and B. canis with fluorescein was not successful. B. abortus RB51 core labeled with fluorescein resulted in sensitivity and specificity values of 93.5% and 99.8%, respectively, with bovine sera and 78.1% and 99.0% with sheep sera. It was not possible to test the dog sera in the FPA.

Staphylococcus aureus capsular polysaccharide type 5 conjugate and whole cell vaccines stimulate antibody responses in cattle

Dairy heifers were immunized subcutaneously with one of four different vaccines which contained preparations of Staphylococcus aureus capsular polysaccharide type 5 (CP5) and a mineral oil adjuvant, or received a placebo containing saline and adjuvant. The vaccine containing a CP5-human serum albumin conjugate (CP5-HSA) and the vaccine with formaldehyde inactivated whole cells expressing CP5, both elicited strong anti-CP5 antibody responses. After two injections three weeks apart and a third injection 10 months later, the mean level and duration of the anti-CP5 antibody response was significantly higher in the whole cell group. No differences were found between the two groups with regard to the relative proportion of IgG subclasses, and the antibody responses to the polysaccharide were composed of both the IgG1 and IgG2. Vaccines containing only free CP5 or CP5 mixed with HSA produced weak and transient humoral immune responses. Only animals vaccinated with the whole cell vaccine or the conjugate vaccine showed responses to CP5 in a lymphocyte proliferation assay conducted one year after the third vaccination. This study indicates that CP5 expressed on the surface of formaldehyde inactivated whole cells, emulsified in an oil adjuvant, gives a strong and long lasting immune response in cattle. The use of conjugation technology, although effective, might not be necessary in order to achieve an immune response against S. aureus CP5 in cattle.

Fluorescence polarization assay for the diagnosis of bovine brucellosis: adaptation to field use

A fluorescence polarization assay (FPA) was used to test whole blood samples prepared by mixing blood cells from cattle without exposure to Brucella abortus (B. abortus) with sera from animals with confirmed (bacteriologically) infection. A cut-off value between negative and positive values was initially established to be 87.2mP. This value was changed to 95mP to increase assay specificity without loss of sensitivity when testing blood samples from negative animals. The FPA technology was applied to whole blood samples in the field and to stored whole blood samples using two diluent buffers. Relative sensitivity and specificity values for the FPA performed in the field, based on buffered antigen plate agglutination test and competitive enzyme immunoassay results were 95.3 and 97.3%, respectively. However, to obtain maximum sensitivity and specificity, a cut-off value of 105mP was determined for fresh whole blood samples. The relative sensitivity and specificity values of the FPA when testing stored whole blood samples were 100% each using a 95mP cut-off.The usefulness of the FPA for testing whole blood samples in the field was demonstrated.

Characterisation of isolates of Staphylococcus aureus from acute, chronic and subclinical mastitis in cows in Norway

Eighty-six Staphylococcus aureus isolates from cases of bovine mastitis were characterised biochemically and with respect to serotype, multilocus enzyme electrophoresis genotypes, antibiotic sensitivity, and production of enterotoxins A through D (SEA-D) and toxic shock syndrome toxin-1 (TSST-1). The samples were obtained from 81 different cows from 79 Norwegian dairy herds in 10 different counties in southern Norway. There was an equal representation of isolates from cases of acute, chronic and subclinical mastitis. Multilocus enzyme electrophoresis using 13 genetic loci showed that 69 of 86 isolates had the same electrophoretic type. This common electrophoretic type comprised isolates that differed in the expression of other phenotypical characteristics studied. Fifty-eight percent of the isolates produced one or more enterotoxins, predominantly a combination of SEC and TSST-1. Capsular serotyping revealed that 95% of the isolates belonged to serotype 8. No correlation was found between the factors studied and the clinical classification of mastitis. It appears that the majority of S. aureus isolates recovered from cases of bovine mastitis in Norway are genetically closely related and express common phenotypical characteristics.

Genetic and serologic evaluation of capsule production by bovine mammary isolates of Staphylococcus aureus and other Staphylococcus spp. from Europe and the United States

Bovine mastitis caused by Staphylococcus aureus is responsible for major economic losses to the dairy industry, and more-effective therapeutic or preventive approaches are sorely needed. The predominance of staphylococcal capsular polysaccharide types 5 and 8 among human isolates from many sources is well documented, but there seems to be a greater variation in the distribution of capsular serotypes among isolates from cows. A total of 636 isolates of S. aureus from cases of bovine mastitis in Sweden, Denmark, Finland, Iceland, Ireland, and the United States were investigated for production of capsular polysaccharide types 5 and 8. Approximately half of all the European isolates tested were of serotype 8, although variation among countries and among isolates of clinical and subclinical origin was observed. Sweden had the highest frequency (87%) of serotypeable isolates, and Finland had the lowest (48%). Capsule types 5 and 8 accounted for only 42% of the U.S. isolates tested. A few isolates showed weak reactivity with CP5 antiserum in a colony blot assay, and an enzyme-linked immunosorbent assay inhibition method confirmed that the levels of capsule produced by these strains were <10% of those produced by control strains. Fifty isolates that failed to react with capsular antisera all possessed the genes for production of capsular polysaccharide type 5 or 8. These results underscore the variability in capsule production by bovine isolates of S. aureus from different geographic regions. This information is important for the rational design of a capsule-based vaccine to prevent S. aureus bovine mastitis.

Creutzfeldt-Jakob disease in Oman: report of two cases

Sporadic Creutzfeldt-Jakob disease (CJD) was diagnosed in two Oman Arab men, aged 50 and 75 years respectively, both with a history of rapidly developing dementia and myoclonic jerks. Illness developed over a period of 3 months in the first case and over six months in the second. Electroencephalography in both subjects showed periodic triphasic sharp waves characteristic of CJD. In neither case was it possible to obtain a brain biopsy or perform autopsy (autopsy is contrary to Islamic practice in the Middle East), however, electrophoresis of cerebrospinal fluid from the second patient revealed the distinctive double protein spots characteristic of CJD. This is the first report of CJD from Oman.

Standardized evaluation of work capacity

A standardized method of evaluation of the work capacity of persons who are impaired by soft-tissue injuries is described. A demonstration project which involved testing 64 impaired subjects is described. The Cal-FCP test battery can be administered independently by a properly trained professional or by a technician under a physician's supervision and requires two hours or less to complete. This study demonstrated that the results of the test battery are unbiased in terms of both gender and age and can be applied to a standardized disability rating system.

Production of enterotoxins and toxic shock syndrome toxin by bovine mammary isolates of Staphylococcus aureus

The production of staphylococcal enterotoxin A (SEA), SEB, SEC, SED, and SEE and toxic shock syndrome toxin 1 by bovine mammary isolates of Staphylococcus aureus was evaluated. Enterotoxin secretion was detected by immunodiffusion using specific polyclonal antisera. Of 262 isolates examined, 75 (28.6%) produced one or more toxins. The most common pattern was secretion of both SEC and SED and toxic shock syndrome toxin 1. No isolates secreted SEE, one produced SEA, and seven secreted SEB.

Secretion of alpha-hemolysin by bovine mammary isolates of Staphylococcus aureus

A total of 262 strains of Staphylococcus aureus isolated from the mammary gland of dairy cows were examined for the production of alpha-hemolysin. Strains were cultured in a liquid medium of casein hydrolysate and yeast extract in an atmosphere of 7% (v/v) CO2 in air. The assay consisted of a dot immunoblotting technique employing bacterial culture supernatants and a mouse monoclonal antibody specific for alpha-hemolysin. Ninety-four percent (247) of 262 strains were positive for alpha-hemolysin by this method, when cultured in the laboratory. This figure is compared with those obtained in previous studies which typically based their results on the hemolytic patterns of isolates on blood agar plates.