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Background: Several studies have indicated the role of quantitative hepatitis B surface antigen (HBsAg) evaluation in managing and prognosis of hepatitis B virus (HBV) infection. Thus, quantitative evaluation of HBsAg using cost-effective assays can be an important approach to managing HBV patients. Objectives: This study aimed to set up and apply an in-house quantitative enzyme-linked immunosorbent assay (ELISA) to evaluate HBsAg in research and diagnosis. Methods: New Zealand white rabbits were immunized with HBsAg. Sera were collected 28 days after immunization, and polyclonal HBsAb (antibody to hepatitis B surface antigen) were purified and evaluated. Then, the in-house quantitative ELISA was optimized. Finally, the functional characteristics of the assay were evaluated using 200 plasma samples compared to commercial ELISA and quantitative TaqMan real-time PCR. Results: The assay has a limit of detection (LOD) of 0.5 ng/mL with a specificity and sensitivity of 94% and 97%, respectively. The assay's highest coefficient of variation (CV) values for intra- and inter-assays were 7.23% and 8.59%, respectively. The correlation of the developed assay with commercial ELISA was 0.987 (P-value = 0.024). The correlations of the developed assay and commercial ELISA with quantitative TaqMan real-time PCR were 0.739 and 0.658, respectively (P-value = 0.017). Conclusions: The developed assay has a suitable sensitivity and specificity. It is also reproducible and well-correlated with commercial assays. Most importantly, it is cost-effective and, thus, can be used for detecting and quantifying HBsAg in research and diagnosis. [ABSTRACT FROM AUTHOR]

Background Patients without human immunodeficiency virus (HIV) are increasingly recognized as being at risk for cryptococcosis. Knowledge of characteristics of cryptococcosis in these patients remains incomplete. Methods We conducted a retrospective study of cryptococcosis in 46 Australian and New Zealand hospitals to compare its frequency in patients with and without HIV and describe its characteristics in patients without HIV. Patients with cryptococcosis between January 2015 and December 2019 were included. Results Of 475 patients with cryptococcosis, 90% were without HIV (426 of 475) with marked predominance in both Cryptococcus neoformans (88.7%) and Cryptococcus gattii cases (94.3%). Most patients without HIV (60.8%) had a known immunocompromising condition: cancer (n = 91), organ transplantation (n = 81), or other immunocompromising condition (n = 97). Cryptococcosis presented as incidental imaging findings in 16.4% of patients (70 of 426). The serum cryptococcal antigen test was positive in 85.1% of tested patients (319 of 375); high titers independently predicted risk of central nervous system involvement. Lumbar puncture was performed in 167 patients to screen for asymptomatic meningitis, with a positivity rate of 13.2% where meningitis could have been predicted by a high serum cryptococcal antigen titer and/or fungemia in 95% of evaluable cases. One-year all-cause mortality was 20.9% in patients without HIV and 21.7% in patients with HIV (P =.89). Conclusions Ninety percent of cryptococcosis cases occurred in patients without HIV (89% and 94% for C. neoformans and C. gattii , respectively). Emerging patient risk groups were evident. A high level of awareness is warranted to diagnose cryptococcosis in patients without HIV. [ABSTRACT FROM AUTHOR]

Rabbit haemorrhagic disease virus (RHDV) is associated with high morbidity and mortality in the European rabbit (Oryctolagus cuniculus). In 2010, a genetically distinct RHDV named RHDV2 emerged in Europe and spread to many other regions, including North America in 2016. Prior to this study it was unknown if eastern cottontails (ECT(s); Sylvilagus floridanus), one of the most common wild lagomorphs in the United States, were susceptible to RHDV2. In this study, 10 wild‐caught ECTs and 10 New Zealand white rabbits (NZWR(s); O. cuniculus) were each inoculated orally with either RHDV (RHDVa/GI.1a; n = 5 per species) or RHDV2 (a recombinant GI.1bP‐GI.2; n = 5 per species) and monitored for the development of disease. Three of the five ECTs that were infected with RHDV2 developed disease consistent with RHD and died at 4 and 6 days post‐inoculation (DPI). The RHDV major capsid protein/antigen (VP60) was detected in the livers of three ECTs infected with RHDV2, but none was detected in the ECTs infected with RHDV. Additionally, RHD viral RNA was detected in the liver, spleen, intestine and blood of ECTs infected with RHDV2, but not in the ECTs infected with RHDV. RHD viral RNA was detected in urine, oral swabs and rectal swabs in at least two of five ECTs infected with RHDV2. One ECT inoculated with RHDV2 seroconverted and developed a high antibody titre by the end of the experimental period (21 DPI). ECTs inoculated with the classic RHDV did not seroconvert. In comparison, NZWRs inoculated with RHDV2 exhibited high mortality (five of five) at 2 DPI and four of five NZWRs inoculated with RHDV either died or were euthanized at 2 DPI indicating both of these viruses were highly pathogenic to this species. This experiment indicates that ECTs are susceptible to RHDV2 and can shed viral RNA, thereby suggesting this species could be involved in the epidemiology of this virus. [ABSTRACT FROM AUTHOR]

In this report, one novel method has been developed to screen the monoclonal antibody against human pancreatic cancer biomarker glypican-1 (GPC1) through the combination of fluorescent cell sorting and single B cell amplification. GPC1-positive B cells were sorted out from the peripheral blood mononuclear cells (PBMCs) by fluorescent cell sorting after the GPC1 immunization to the New Zealand white rabbit. Then, total RNA was extracted and reversely transcribed into cDNA, which was used as the template, and the variable region sequences of both heavy and light chains were amplified from the same B cell. Next, their recombinant antibody was expressed and purified from the human 293T cell after the antibody gene amplification and expression vector construction. The enzyme-linked immunosorbent assay (ELISA) and flow cytometry assays were used to determine the antibody affinity. The antibody named GPC-12 that we screened and obtained was proven to have natural heavy-light chain pairing information, and it was highly specific to the GPC1 antigen, and the affinity could reach 1 × 10−7 M. Overall, an effective and novel method has been successfully developed to screen the antibody by combining the fluorescent cell sorting and single-cell amplifying technologies, which was proved to be workable in our setting. [ABSTRACT FROM AUTHOR]

GLO:FRK/01apr21:imcb12454-fig-0001.jpg PHOTO (COLOR): . gl L-R: Professor Katharina Gaus, Professor Barbara Heslop, Professor Margaret Baird, Miss Dora Lush, Dr Margaret Holmes and Miss F Eleanor Williams MBE ARRC. Another eminent woman immunologist under the mentorship of MacFarlane Burnett at the WEHI was Dr Margaret Holmes, who discovered that immune cells are responsible for initiating autoimmune conditions. The topic of women in science usually draws immediate mention of Marie Curie, the first person to win two Nobel Prizes, first in physics in 1903 (with her husband Pierre), and then in chemistry in 1911. Professors Barbara Heslop CBE and Margaret Baird were two leading immunologists at the University of Otago, both of whom gained recognition in the medical community for their pioneering research and teaching, at a time when women scientists and role models were scarce in New Zealand. [Extracted from the article]

Background: Platinum-based neoadjuvant chemotherapy followed by delayed primary surgery (DPS) is an established strategy for women with newly diagnosed, advanced-stage epithelial ovarian cancer. Although this therapeutic approach has been validated in randomised, phase 3 trials, evaluation of response to neoadjuvant chemotherapy using Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST), and cancer antigen 125 (CA125) has not been reported. We describe RECIST and Gynecologic Cancer InterGroup (GCIG) CA125 responses in patients receiving platinum-based neoadjuvant chemotherapy followed by DPS in the ICON8 trial.Methods: ICON8 was an international, multicentre, randomised, phase 3 trial done across 117 hospitals in the UK, Australia, New Zealand, Mexico, South Korea, and Ireland. The trial included women aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-2, life expectancy of more than 12 weeks, and newly diagnosed International Federation of Gynecology and Obstetrics (FIGO; 1988) stage IC-IIA high-grade serous, clear cell, or any poorly differentiated or grade 3 histological subtype, or any FIGO (1988) stage IIB-IV epithelial cancer of the ovary, fallopian tube, or primary peritoneum. Patients were randomly assigned (1:1:1) to receive intravenous carboplatin (area under the curve [AUC]5 or AUC6) and intravenous paclitaxel (175 mg/m2 by body surface area) on day 1 of every 21-day cycle (control group; group 1); intravenous carboplatin (AUC5 or AUC6) on day 1 and intravenous dose-fractionated paclitaxel (80 mg/m2 by body surface area) on days 1, 8, and 15 of every 21-day cycle (group 2); or intravenous dose-fractionated carboplatin (AUC2) and intravenous dose-fractionated paclitaxel (80 mg/m2 by body surface area) on days 1, 8, and 15 of every 21-day cycle (group 3). The maximum number of cycles of chemotherapy permitted was six. Randomisation was done with a minimisation method, and patients were stratified according to GCIG group, disease stage, and timing and outcome of cytoreductive surgery. Patients and clinicians were not masked to group allocation. The scheduling of surgery and use of neoadjuvant chemotherapy were determined by local multidisciplinary case review. In this post-hoc exploratory analysis of ICON8, progression-free survival was analysed using the landmark method and defined as the time interval between the date of pre-surgical planning radiological tumour assessment to the date of investigator-assessed clinical or radiological progression or death, whichever occurred first. This definition is different from the intention-to-treat primary progression-free survival analysis of ICON8, which defined progression-free survival as the time from randomisation to the date of first clinical or radiological progression or death, whichever occurred first. We also compared the extent of surgical cytoreduction with RECIST and GCIG CA125 responses. This post-hoc exploratory analysis includes only women recruited to ICON8 who were planned for neoadjuvant chemotherapy followed by DPS and had RECIST and/or GCIG CA125-evaluable disease. ICON8 is closed for enrolment and follow-up, and registered with ClinicalTrials.gov, NCT01654146.Findings: Between June 6, 2011, and Nov 28, 2014, 1566 women were enrolled in ICON8, of whom 779 (50%) were planned for neoadjuvant chemotherapy followed by DPS. Median follow-up was 29·5 months (IQR 15·6-54·3) for the neoadjuvant chemotherapy followed by DPS population. Of 564 women who had RECIST-evaluable disease at trial entry, 348 (62%) had a complete or partial response. Of 727 women who were evaluable by GCIG CA125 criteria at the time of diagnosis, 610 (84%) had a CA125 response. Median progression-free survival was 14·4 months (95% CI 9·2-28·0; 297 events) for patients with a RECIST complete or partial response and 13·3 months (8·1-20·1; 171 events) for those with RECIST stable disease. Median progression-free survival for women with a GCIG CA125 response was 13·8 months (95% CI 8·8-23·4; 544 events) and 9·7 months (5·8-14·5; 111 events) for those without a GCIG CA125 response. Complete cytoreduction (R0) was achieved in 187 (56%) of 335 women with a RECIST complete or partial response and 73 (42%) of 172 women with RECIST stable disease. Complete cytoreduction was achieved in 290 (50%) of 576 women with a GCIG CA125 response and 30 (30%) of 101 women without a GCIG CA125 response.Interpretation: The RECIST-defined radiological response rate was lower than that frequently quoted to patients in the clinic. RECIST and GCIG CA125 responses to neoadjuvant chemotherapy for epithelial ovarian cancer should not be used as individual predictive markers to stratify patients who are likely to benefit from DPS, but instead used in conjunction with the patient's clinical capacity to undergo cytoreductive surgery. A patient should not be denied surgery based solely on the lack of a RECIST or GCIG CA125 response.Funding: Cancer Research UK, UK Medical Research Council, Health Research Board in Ireland, Irish Cancer Society, and Cancer Australia. [ABSTRACT FROM AUTHOR]

Objective: To study the impact of extended human leukocyte antigen (HLA)-G and HLA-F haplotypes on time to pregnancy as measured by the number of treatment cycles in a cohort of couples in infertility treatment.Design: Prospective cohort study of couples undergoing infertility treatment.Setting: University hospital.Patient(s): A cohort of 127 couples and four single women in infertility treatment.Intervention(s): Next-generation sequencing of the HLA-G gene and genotyping of three HLA-F locus single-nucleotide polymorphisms (SNPs).Main Outcome Measure(s): Extended HLA-F.HLA-G haplotypes, HLA-G promoter haplotypes and HLA-G 3'UTR haplotypes and their association with time to pregnancy as measured by number of treatment cycles until achievement of pregnancy with a live birth. Linkage disequilibrium between HLA-G variations and three HLA-F locus SNPs that impact time to pregnancy.Result(s): The effect of the HLA-G 3'UTR haplotype, UTR-4, was significantly increased, or modified, if the partner was a carrier compared to being a noncarrier. Extended HLA-F.HLA-G haplotypes, HLA-G promoter haplotypes, and the HLA-G 14 bp indel of the female partners were not associated with time to pregnancy. However, a trend for an association of the HLA-G 14bp insertion allele with a higher frequency of miscarriage than the 14bp deletion allele was observed. Certain HLA-G variations are in linkage disequilibrium with three HLA-F locus SNPs that influence time to pregnancy.Conclusion(s): HLA-G UTR-4 is significantly associated with time to pregnancy in couples undergoing infertility treatment. The findings could imply that both male and female HLA class Ib genetics have clinical relevance in reproduction. [ABSTRACT FROM AUTHOR]

Background. Although Botulinum Toxin Type A (BTXA) has been applied to scar prevention and treatment, the mechanisms still require further exploration. Objective. To investigate the effects of BTXA on microvessels in the hypertrophic scar models on rabbit ears. Methods. Eight big-eared New Zealand rabbits (males or females) were selected to establish scar models. One ear of each rabbit (4 models in each ear) was selected randomly to be injected with BTXA immediately after modeling and included in the treated group, while the opposite ear was untreated and included in the control group. The growth of scars in each group was observed and recorded, and 4 rabbits were sacrificed on days 30 and 45 after modeling. Then, scar height was measured by hematoxylin-eosin (HE) staining, vascular endothelial growth factor (VEGF) expression was detected by immunohistochemical (IHC) testing, and microvessel density (MVD) was calculated based on CD34 (human hematopoietic progenitor cell antigen). Results. The wounds in each group were well healed and free from infection or necrosis. On days 30 and 45, the scar height, MVD value, and VEGF expression in the treated group were lower than those in the control group (P < 0.05). For the treated group, the above indicators on day 45 were lower than on day 30 (P > 0.05). Besides, there was a positive correlation between the MVD value and the VEGF expression in the treated group (P < 0.05). Conclusion. The injection of BTXA immediately after modeling inhibits VEGF expression and reduces angiogenesis, thereby inhibiting hypertrophic scar formation. [ABSTRACT FROM AUTHOR]

Coccidiosis in rabbit production is responsible for high morbidity, mortality, and economic losses. The use of natural antimicrobial substances in rabbits represents a promising way to improve their health and production. The aim of the present study was to assess the activity of Salix babylonica hydroalcoholic extract (SBHE) on the elimination of Eimeria spp. in rabbits. The phytochemical compounds and chemical composition of SBHE were determined. The cytotoxicity of SBHE was determined by a microwell assay using Artemia salina. Twenty-five New Zealand rabbits, 28 days old and 872 ± 171 g body weight (BW), were used in a completely randomized design. The rabbits were assigned to five groups of five rabbits, control group (A) received only basal diet (BD), B group received BD + 25 mg/kg BW of SBHE, C group received BD + 50 mg/kg BW of SBHE, D group received BD + 100 mg/kg BW of SBHE, and E group received BD + coccidiostat Baycox® (75 mg/kg body weight) for 28 days. Feces samples were collected at days 0, 7, 14, 21, and 28; morphological and morphometric identifications of Eimeria were carried out by the flotation technique and counting of oocysts by the McMaster technique. The rabbits were found naturally infected with Eimeria spp. The SBHE present phytochemicals with anticoccidial activity, and the cytotoxicity test indicate that this extract is nontoxic. This study demonstrates that oral administration of SBHE at 25 and 50 mg/kg BW reduced the release of oocysts per gram of feces. This effect was observed at day 14 and had the most significant effect at day 28 for both concentrations. The results indicate that SBHE could be a natural alternative for the control of coccidiosis in rabbit production. [ABSTRACT FROM AUTHOR]

Background: Androgen-deprivation therapy in patients with prostate cancer who have relapsed with rising prostate-specific antigen concentration only (PSA-only relapse), or with non-curable but asymptomatic disease at diagnosis, could adversely affect quality of life at a time when the disease itself does not. We aimed to compare the effect of immediate versus delayed androgen-deprivation therapy on health-related quality of life over 5 years in men enrolled in the TOAD (Timing of Androgen Deprivation) trial.Methods: This randomised, multicentre, open-label, phase 3 trial done in 29 public and private cancer centres across Australia, New Zealand, and Canada compared immediate with delayed androgen-deprivation therapy in men with PSA-only relapse after definitive treatment, or de-novo non-curable disease. Patients were randomly assigned (1:1) with a database-embedded, dynamically balanced algorithm to immediate androgen-deprivation therapy (immediate therapy group) or to delayed androgen-deprivation therapy (delayed therapy group). Any type of androgen-deprivation therapy was permitted, as were intermittent or continuous schedules. The European Organisation for Research and Treatment of Cancer (EORTC) quality-of-life questionnaires QLQ-C30 and PR25 were completed before randomisation, every 6 months for 2 years, and annually for a further 3 years. The primary outcome of the trial, reported previously, was overall survival, with global health-related quality of life at 2 years as a secondary endpoint. Here we report prespecified secondary objectives of the quality-of-life endpoint. Analysis was by intention to treat. Statistical significance was set at p=0·0036. The trial was registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12606000301561, and ClinicalTrials.gov, number NCT00110162.Findings: Between Sept 3, 2004, and July 13, 2012, 293 men were recruited and randomly assigned; 151 to the delayed therapy group and 142 to the immediate therapy group. There was no difference between the two groups in global health-related quality of life over 2 years from randomisation. There were no statistically significant differences in global quality of life, physical functioning, role functioning, or emotional functioning, fatigue, dyspnoea, insomnia, or feeling less masculine over the entire 5 years after randomisation. Sexual activity was lower in the immediate therapy group than in the delayed group at 6 and 12 months (at 6 months mean score 29·20 [95% CI 24·59-33·80] in the delayed group vs 10·40 [6·87-13·93] in the immediate group, difference 18·80 [95% CI 13·00-24·59], p<0·0001; at 12 months 28·63 [24·07-33·18] vs 13·76 [9·94-17·59], 14·86 [8·95-20·78], p<0·0001), with the differences exceeding the clinically significant threshold of 10 points until beyond 2 years. The immediate therapy group also had more hormone-treatment-related symptoms at 6 and 12 months (at 6 months mean score 8·48 [95% CI 6·89-10·07] in the delayed group vs 15·97 [13·92-18·02] in the immediate group, difference -7·49 [-10·06 to -4·93], p<0·0001; at 12 months 9·32 [7·59-11·05] vs 17·07 [14·75-19·39], -7·75 [-10·62 to -4·89], p<0·0001), but with differences below the threshold of clinical significance. For the individual symptoms, hot flushes were clinically significantly higher in the immediate group (adjusted proportion 0·31 for delayed therapy vs 0·55 for immediate therapy, adjusted odds ratio 2·87 [1·96-4·21], p<0·0001) over the 5-year period, as were nipple or breast symptoms (0·06 vs 0·14, 2·64 [1·61-4·34], p=0·00013).Interpretation: Immediate use of androgen-deprivation therapy was associated with early detriments in specific hormone-treatment-related symptoms, but with no other demonstrable effect on overall functioning or health-related quality of life. This evidence can be used to help decision making about treatment initiation for men at this disease stage.Funding: Australian National Health and Medical Research Council and Cancer Councils, The Royal Australian and New Zealand College of Radiologists, Mayne Pharma Australia, Tolmar Australia. [ABSTRACT FROM AUTHOR]

Background: Although understanding chlamydia incidence assists prevention and control, analyses based on diagnosed infections may distort the findings. Therefore, we determined incidence and examined risks in a birth cohort based on self-reports and serology.Methods: Self-reported chlamydia and behavior data were collected from a cohort born in New Zealand in 1972/3 on several occasions to age 38 years. Sera drawn at ages 26, 32, and 38 years were tested for antibodies to Chlamydia trachomatis Pgp3 antigen using a recently developed assay, more sensitive in women (82.9%) than men (54.4%). Chlamydia incidence by age period (first coitus to age 26, 26-32, and 32-38 years) was calculated combining self-reports and serostatus and risk factors investigated by Poisson regression.Results: By age 38 years, 32.7% of women and 20.9% of men had seroconverted or self-reported a diagnosis. The highest incidence rate was to age 26, 32.7 and 18.4 years per 1000 person-years for women and men, respectively. Incidence rates increased substantially with increasing number of sexual partners. After adjusting age period incidence rates for partner numbers, a relationship with age was not detected until 32 to 38 years, and then only for women.Conclusions: Chlamydia was common in this cohort by age 38, despite the moderate incidence rates by age period. The strongest risk factor for incident infection was the number of sexual partners. Age, up to 32 years, was not an independent factor after accounting for partner numbers, and then only for women. Behavior is more important than age when considering prevention strategies. [ABSTRACT FROM AUTHOR]

Purpose. Manuka honey (MH) is an antibacterial agent specific to the islands of New Zealand containing both hydrogen peroxide and a Unique Manuka Factor (UMF). Although the antibacterial properties of MH have been studied, the effect of varying UMF of MH incorporated into tissue engineered scaffolds have not. Therefore, this study was designed to compare silk fibroin cryogels and electrospun scaffolds incorporated with a 5% MH concentration of various UMF. Methods. Characteristics such as porosity, bacterial clearance and adhesion, and cytotoxicity were compared. Results. Pore diameters for all cryogels were between 51 and 60 µm, while electrospun scaffolds were 10 µm. Cryogels of varying UMF displayed clearance of approximately 0.16 cm for E. coli and S. aureus. In comparison, the electrospun scaffolds clearance ranged between 0.5 and 1 cm. A glucose release of 0.5 mg/mL was observed for the first 24 hours by all scaffolds, regardless of UMF. With respect to cytotoxicity, neither scaffold caused the cell number to drop below 20,000. Conclusions. Overall, when comparing the effects of the various UMF within the two scaffolds, no significant differences were observed. This suggests that the fabricated scaffolds in this study displayed similar bacterial effects regardless of the UMF value. [ABSTRACT FROM AUTHOR]

In New Zealand, a new diagnostic approach for the control of paratuberculosis in mixed aged milking cows has been developed using a combination of ELISA and quantitative fecal PCR (f-qPCR). Our analysis was designed to evaluate performance of these individual tests in infected or infectious mixed aged cows across the prevalence of infection typically encountered on NZ dairy farms and calculate test accuracy when used as a screening test of serological ELISAs for four separate antigens read in parallel followed by a confirmatory quantitative f-qPCR test. Data from a cross-sectional study of 20 moderate prevalence herds was combined with existing data from 2 low and 20 high prevalence herds forming a dataset of 3845 paired serum and fecal samples. Incidence of clinical Johne's disease (JD) was used to classify herds into three prevalence categories. High (≥ 3% annual clinical JD for the last three years), moderate (<3 – 1%) and low (<1% incidence for at least the last five years). Positive tests were declared if> 50 ELISA units and f-qPCR at two cut-points (≥1 × 104 genomes/mL or >1 × 103 genomes/mL). Fixed Bayesian latent class models at both f-qPCR cut-points, accounted for conditional independence and paired conditional dependence. Mixed models at both f-qPCR cut-points, using a different mechanism to account for conditional dependencies between tests were also implemented. Models (24 in number) were constructed using OpenBUGS. The aim was to identify Mycobacterium avium subsp. paratuberculosis (MAP) infected cows that met at least one of two criteria: shedding sufficient MAP in feces to be detected by f-qPCR or mounting a detectable MAP antibody response. The best fit to the data was obtained by modelling pairwise dependencies between tests in a fixed model or by accounting for dependencies in a mixed model at a fecal cut-off of ≥1 × 104 genomes/mL. Test performance differed with prevalence, but models were robust to prior assumptions. For the fixed model, at a prevalence of 0.29 (95 % probability interval (PI) = 0.25−0.33), as a screening plus confirmatory f-qPCR, post-test probability for disease in a positive animal was 0.84 (95 %PI = 0.80−0.88) and 0.16 (95 %PI = 0.15−0.18) for disease in a test negative animal. In low prevalence herds (0.01(95 %PI = 0.00−0.04)) the equivalent figures were 0.84 (95 %PI = 0.08−0.92) and 0.00 (95 %PI = 0.00−0.02). These results suggest this is a useful tool to control JD on dairy farms, particularly in herds with higher levels of infection, where the sampling and testing cost per animal is defrayed across more detected animals. [ABSTRACT FROM AUTHOR]

• Ontario lambs develop salivary IgA to CarLA in their first grazing season. • Detectable CarLA antibody can persist over winter despite minimal nematode exposure. • Salivary CarLA levels are positively correlated in a lamb's first two years of life. • Ontario ewe lambs with high CarLA antibody shed fewer nematode eggs. Leveraging mucosal immunity is a promising method for controlling gastrointestinal nematode (GIN) parasitism in sheep. Salivary antibody to carbohydrate larval antigen (sCarLA), a heritable measure of immunity to third-stage GIN larvae (L 3), has been successfully applied to genetic improvement programs in New Zealand. However, sCarLA levels wane in the absence of ongoing GIN exposure. New Zealand's temperate climate permits year-round exposure to L 3 , but cold winters in boreal regions such as Ontario, Canada interrupt exposure for five months or more. This study investigated associations between sCarLA levels, GIN parasitism, and indicators of overall health in sheep grazing under Ontario conditions. A commercial flock of 140 Rideau cross ewe lambs were followed from approximately 30 days of age in May 2016 until November 2017, including lambing and lactation in the spring of 2017. Every 6–8 weeks during the grazing season and at mid-gestation in March 2017, fecal egg counts were performed, blood collected to assess serum albumin, globulin, and hematocrit, and pasture samples obtained to confirm exposure to infective larvae. Measurements of sCarLA level were performed at the beginning, middle, and end of each grazing season, and at mid-gestation. Spearman's rank correlation coefficients were calculated to compare sCarLA levels over time, and general linear mixed models created to evaluate associations between sCarLA levels, GIN fecal egg count, hematocrit, serum albumin, and serum globulin. Levels of sCarLA followed a similar seasonal pattern to GIN fecal egg counts with a 6–8 week delay; much higher sCarLA levels were observed in the second grazing season. The proportion of the flock with detectable sCarLA (≥ 0.3 units/mL) was 68.3 % by the end of the first grazing season, declined over winter to 43.9 % at lambing, and approached 100 % after 3 months of grazing in the second grazing season. Correlations between sCarLA levels over time were consistently positive, of weak to moderate strength, and significant (p < 0.05). At all time points, sCarLA level was significantly (p < 0.001) and negatively associated with fecal egg counts. The flock displayed minimal variability in hematocrit, serum albumin, and serum globulin; none of which were significantly associated with sCarLA levels. These results suggest that sCarLA can be maintained over winter and is a useful measure of immunity to GINs in sheep under Ontario grazing conditions. [ABSTRACT FROM AUTHOR]

Highlights from the article: The New Zealand (NZ) population is made up of many ethnic groups, with 88 different ethnicities identified in the national census of 2013, this contributes to human leucocyte antigen (HLA) diversity in New Zealand. HLA alleles of 2832 unrelated individuals typed by next generation sequencing (NGS) were analysed to examine HLA polymorphism in the modern New Zealand population. Twelve alleles not listed as C/WD in 2013 were found to be common (allele frequency >0.001), (DRB3*02:24, DRB3*03:01:03, DQA1*01:04:02, DQB1*05:01:24, DQB1*06:01:05, DPA1*02:01:02, DPA1*02:02:02, DPA1*02:06, DPA1*02:07, DPA1*02:01:04, DPB1*135:01, DPB1*296:01); and 14 alleles were found to be common while only listed as well documented in 2013 (A*02:12, B*15:06, B*40:10:01, B*56:02:01, C*03:02:02, C*04:82, C*07:01:02, C*15:05:02, DRB1*14:08, DRB4*01:03:02, DQA1*01:02:02, DQA1*05:09, DQA1*06:01:01, DPB1*104:01).