A systematized review and qualitative synthesis of potential risk factors associated with the occurrence of non-O157 Shiga toxin-producing Escherichia coli (STEC) in the primary production of cattle.

Human infection with Shiga toxin-producing Escherichia coli (STEC) causes an estimated 2.8 million cases of acute illness worldwide each year. Serogroup O157 is the most commonly diagnosed STEC in humans, but cases linked to non-O157 STEC serogroups have increased recently due to increased surveillance and improvements to detection methods. Cattle are an important reservoir for STEC O157 and the same may be true for non-O157 STEC; therefore, reducing the occurrence of these pathogens in cattle could mitigate human infection risk. A systematized literature review of articles published within the Scopus database since 2010 (employing a partially systematic approach) was therefore conducted followed by qualitative synthesis of evidence to provide a structured overview of potential risk factors for non-O157 STEC in primary cattle production. Overall, few relevant studies were identified (n = 22), highlighting that more studies are needed. Consistently significant associations were only identified with respect to cattle age (broadly higher rate of isolation from young animals compared to adults) and season of sampling (generally increased isolation of non-O157 STEC in summer). However, wide variation in study designs, including notable differences in laboratory detection methods, means drawing more general conclusions is currently not possible based on the results of this review. However, it is likely that the development of more sensitive methods for non-O157 STEC detection in potential livestock reservoirs and increased standardization across statistically sound epidemiological investigations are required to identify pertinent risk factors.

Field investigations of multidrug-resistant Salmonella Infantis epidemic strain incursions into broiler flocks in England and Wales.

Salmonella Infantis is a major public health concern and has become established in the broiler sector in some European countries, as well as globally, and is frequently multidrug resistant (MDR). Three broiler farms in England and Wales, which had incursions of MDR S. Infantis between 2013 and 2017, were investigated longitudinally. The company feed mill and two associated hatcheries were intensively sampled. Following each visit, advice on cleaning, disinfection and other control measures for Salmonella was given to help eliminate S. Infantis from the premises. Four samples collected from inside the broiler houses after cleaning and disinfection were Salmonella-positive, indicating cleaning and disinfection within houses was generally effective. However, the exterior of persistently infected houses remained substantially contaminated and feeding systems could not be sampled. Clearance of S. Infantis from affected houses requires additional attention to decontamination of these aspects. Sixty S. Infantis isolates were tested for antimicrobial susceptibility by disk diffusion tests. All isolates were MDR, with resistance to at least nalidixic acid (Na), tetracycline (T), compound sulphonamide (Su), streptomycin (S) and furazolidone. This is a similar resistance pattern to the previously identified MDR (NaSSuT) clone in some European countries. The study shows that to remove S. Infantis from premises effectively, a combined approach to poultry houses and the surrounding farm environment is necessary. A revised cleaning and disinfection programme was developed that was associated with the clearance of MDR S. Infantis from persistently infected and newly infected broiler flocks, and UK livestock remains free of MDR S. Infantis. RESEARCH HIGHLIGHTS Standard cleaning and disinfection protocols did not completely eliminate infection. A revised cleaning and disinfection programme was developed. Disinfecting feeder lines and external areas was key to eliminating S. Infantis. Identified similar antimicrobial resistance pattern to MDR epidemic S. Infantis.

Observations on the introduction and dissemination of Salmonella in three previously low prevalence status pig farms in the United Kingdom.

In the United Kingdom a serological Salmonella surveillance scheme was run in pigs up to 2012. Farms that maintained a low seroprevalence (<10%) were recognised as "Platinum" pig farms. The aim of this study was to investigate the occurrence and distribution of Salmonella in three farms (17P, 18P and 46P) that had lost their "Platinum" status. Four visits to each farm were made over a period of 15 months. The sampling was carried out by collecting pooled pen floor faecal swab and environmental samples. All samples were tested for Salmonella by a modification of ISO6579 Annex D, and serovars were determined for all isolates. The Salmonella prevalence peaked in the Summer/Autumn months and all farms were still positive at the end of the study. The overall sample prevalence was higher in farm 17P (46%) and 18P (35%) than 46P (19%). Monophasic S. Typhimurium (mST) represented 77.8% of the Salmonella isolates, mainly from farms 17P and 46P. The mST isolated at the initial visit may have been introduced via other livestock present on farm or introduction into the herd of infected animals. The results of this study suggest that incursion of mST was likely to be the main cause of the loss of "Platinum" status and confirm that mST can persist in pigs and their environment.

Observations on Salmonella contamination of commercial duck farms before and after cleaning and disinfection.

In the European Union, statutory control of Salmonella is in place in the chicken and turkey sectors, but not in the duck sector. In this study, 14 Salmonella-positive duck farms were sampled before and after cleaning and disinfection, and once the houses had been restocked with a new flock. The cleaning and disinfection programmes used were subdivided into two main categories: ones in which a final formaldehyde disinfection step was included (1) and ones in which it was not included (2). Several types of samples were collected during the study, and faecal samples were those more frequently positive (62% of faecal samples were positive for Salmonella in comparison to 2-23% of samples from all the other sample categories) (P < 0.001). Independently of the cleaning and disinfection programme used, there was a statistically significant (P < 0.001) reduction in the percentage of Salmonella-positive samples between before cleaning and disinfection (41.1%) and after cleaning and disinfection (3.1%). After restocking, the number of Salmonella-positive samples increased significantly (P < 0.001), with 65.3% of the samples tested being positive for Salmonella. Farms in which disinfection programme 1 was used were 5.34 times less likely to have samples positive for Salmonella after cleaning and disinfection than farms which implemented programme 2. Formaldehyde acts effectively against Salmonella even in the presence of some residual organic matter. Limited residual contamination on farms after cleaning and disinfection represents a risk of infection for young ducklings, and thorough cleaning and disinfection procedures should be implemented to reduce the carry-over of infection between flocks.

Assessment of anti-Salmonella activity of boot dip samples.

The introduction of pathogens from the external environment into poultry houses via the boots of farm workers and visitors presents a significant risk. The use of boot dips containing disinfectant to help prevent this from happening is common practice, but the effectiveness of these boot dips as a preventive measure can vary. The aim of this study was to assess the anti-Salmonella activity of boot dips that are being used on poultry farms. Boot dip samples were collected from commercial laying hen farms in the UK and tested within 24 hours of receipt at the laboratory to assess their anti-Salmonella activity. All boot dip samples were tested against a field strain of Salmonella enterica serovar Enteritidis using three test models: pure culture, paper disc surface matrix and yeast suspension model. Of the 112 boot dip samples tested 83.6% were effective against Salmonella in pure culture, 37.3% in paper disc surface matrix and 44.5% in yeast suspension model. Numerous factors may influence the efficacy of the disinfectants. Disinfectants used in the dips may not always be fully active against surface or organic matter contamination; they may be inaccurately measured or diluted to a concentration other than that specified or recommended; dips may not be changed regularly or may have been exposed to rain and other environmental elements. This study showed that boot dips in use on poultry farms are frequently ineffective.

DNA methylation profiling of human chromosomes 6, 20 and 22.

DNA methylation is the most stable type of epigenetic modification modulating the transcriptional plasticity of mammalian genomes. Using bisulfite DNA sequencing, we report high-resolution methylation profiles of human chromosomes 6, 20 and 22, providing a resource of about 1.9 million CpG methylation values derived from 12 different tissues. Analysis of six annotation categories showed that evolutionarily conserved regions are the predominant sites for differential DNA methylation and that a core region surrounding the transcriptional start site is an informative surrogate for promoter methylation. We find that 17% of the 873 analyzed genes are differentially methylated in their 5' UTRs and that about one-third of the differentially methylated 5' UTRs are inversely correlated with transcription. Despite the fact that our study controlled for factors reported to affect DNA methylation such as sex and age, we did not find any significant attributable effects. Our data suggest DNA methylation to be ontogenetically more stable than previously thought.

Characterization of the invasiveness of monophasic and aphasic Salmonella Typhimurium strains in 1-day-old and point-of-lay chickens.

Egg-related outbreaks of salmonellosis are a significant health concern. Although Salmonella Enteritidis (SE) is the major egg-associated serotype, Salmonella Typhimurium (ST) can also infect the hen's reproductive tract and contaminate eggs. Recently, monophasic and aphasic variants of ST have been reported with increased frequency in Europe, and the isolation of these variants from laying flocks triggers the same legislative restrictions associated with biphasic ST strains. However, little is known about the colonization, invasiveness and persistence of monophasic and aphasic ST strains in laying hens. In this study, seven groups of 1-day-old and point-of-lay commercial Hy-line chicken layers were separately challenged with four different strains of monophasic ST, one aphasic ST, one biphasic ST and one egg-invasive SE strain. Tissue samples and cloacal swabs (point-of-lay chickens only) were collected at regular intervals post challenge in order to recover the Salmonella challenge strains. In 1-day-old chicks, only the aphasic ST strain and the SE strain were recovered after direct plating, suggesting that the number of salmonellas colonizing the tissues of the chicks infected with the other strains was likely to be low. Interestingly, all of the strains colonized well in the point-of-lay chickens, and there was no statistical difference in the overall number of positive samples or Salmonella counts between the seven strains. Salmonella was recovered from the point-of-lay birds to the end of the study (20 days after challenge). Monophasic and aphasic ST strains colonized point-of-lay birds as efficiently as biphasic ST and SE strains. Further studies are necessary to estimate the invasiveness of these strains in naturally-infected vaccinated laying hens, and to assess the impact of natural infection on egg contamination.

Complex haplotypes, copy number polymorphisms and coding variation in two recently divergent mouse strains.

Inbred mouse strains provide the foundation for mouse genetics. By selecting for phenotypic features of interest, inbreeding drives genomic evolution and eliminates individual variation, while fixing certain sets of alleles that are responsible for the trait characteristics of the strain. Mouse strains 129Sv (129S5) and C57BL/6J, two of the most widely used inbred lines, diverged from common ancestors within the last century, yet very little is known about the genomic differences between them. By comparative genomic hybridization and sequence analysis of 129S5 short insert libraries, we identified substantial structural variation, a complex fine-scale haplotype pattern with a continuous distribution of diversity blocks, and extensive nucleotide variation, including nonsynonymous coding SNPs and stop codons. Collectively, these genomic changes denote the level and direction of allele fixation that has occurred during inbreeding and provide a basis for defining what makes these mouse strains unique.

Mutagenic insertion and chromosome engineering resource (MICER).

Embryonic stem cell technology revolutionized biology by providing a means to assess mammalian gene function in vivo. Although it is now routine to generate mice from embryonic stem cells, one of the principal methods used to create mutations, gene targeting, is a cumbersome process. Here we describe the indexing of 93,960 ready-made insertional targeting vectors from two libraries. 5,925 of these vectors can be used directly to inactivate genes with an average targeting efficiency of 28%. Combinations of vectors from the two libraries can be used to disrupt both alleles of a gene or engineer larger genomic changes such as deletions, duplications, translocations or inversions. These indexed vectors constitute a public resource (Mutagenic Insertion and Chromosome Engineering Resource; MICER) for high-throughput, targeted manipulation of the mouse genome.

Geographical and temporal distribution of multidrug-resistant Salmonella Infantis in Europe and the Americas.

Recently emerged S. Infantis strains carrying resistance to several commonly used antimicrobials have been reported from different parts of the globe, causing human cases of salmonellosis and with occurrence reported predominantly in broiler chickens. Here, we performed phylogenetic and genetic clustering analyses to describe the population structure of 417 S. Infantis originating from multiple European countries and the Americas collected between 1985 and 2019. Of these, 171 were collected from 56 distinct premises located in England and Wales (E/W) between 2009 and 2019, including isolates linked to incursions of multidrug-resistant (MDR) strains from Europe associated with imported poultry meat. The analysis facilitated the comparison of isolates from different E/W sources with isolates originating from other countries. There was a high degree of congruency between the outputs of different types of population structure analyses revealing that the E/W and central European (Germany, Hungary, and Poland) isolates formed several disparate groups, which were distinct from the cluster relating to the United States (USA) and Ecuador/Peru, but that isolates from Brazil were closely related to the E/W and the central European isolates. Nearly half of the analysed strains/genomes (194/417) harboured the IncFIB(pN55391) replicon typical of the "parasitic" pESI-like megaplasmid found in diverse strains of S. Infantis. The isolates that contained the IncFIB(pN55391) replicon clustered together, despite originating from different parts of the globe. This outcome was corroborated by the time-measured phylogeny, which indicated that the initial acquisition of IncFIB(pN55391) likely occurred in Europe in the late 1980s, with a single introduction of IncFIB(pN55391)-carrying S. Infantis to the Americas several years later. Most of the antimicrobial resistance (AMR) genes were identified in isolates that harboured one or more different plasmids, but based on the short-read assemblies, only a minority of the resistance genes found in these isolates were identified as being associated with the detected plasmids, whereas the hybrid assemblies comprising the short and long reads demonstrated that the majority of the identified AMR genes were associated with IncFIB(pN55391) and other detected plasmid replicon types. This finding underlies the importance of applying appropriate methodologies to investigate associations of AMR genes with bacterial plasmids.

Efficacy of Five Disinfectant Products Commonly Used in Pig Herds against a Panel of Bacteria Sensitive and Resistant to Selected Antimicrobials.

The growing threat of antimicrobial resistance worldwide has led to an increasing concern in the human, veterinary, and environmental fields, highlighting the need for strategies to effectively control bacterial contamination. Correct biosecurity practices, including the appropriate use of disinfectants, play a crucial role in controlling bacterial contamination. This study aimed to verify whether the recommended concentrations defined according to the Defra General Orders concentration (GO, published by the UK Department for Environment, Food and Rural Affairs' disinfectant-approval scheme) of five commercial disinfectant preparations (peroxygen-based, phenol-based, two halogen-releasing agents, and glutaraldehyde/quaternary ammonium compound-based; disinfectants A to E, respectively) were sufficient to inhibit growth and inactivate selected bacterial strains, including some that carry known phenotypic patterns of multidrug resistance. The effectiveness of each disinfectant was expressed as the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, determined by the broth-microdilution method. The results indicate that the type of disinfectant and its concentration influence the inhibitory and bactericidal efficacy. The glutaraldehyde/quaternary ammonium compound-based (disinfectant D) and chlorocresol-based products (disinfectant B) were the most effective, and the GO concentration was bactericidal in all the strains tested. The efficacy of the other compounds varied, depending on the bacterial species tested. The GO concentrations were at least able to inhibit the bacterial growth in all the products and bacterial strains tested. A greater tolerance to the compounds was observed in the strains of E. coli with multidrug-resistance profiles compared to the strains that were sensitive to the same antimicrobials.

Comprehensive clinical assessment identifies specific neurocognitive deficits in working-age patients with long-COVID.

INTRODUCTION: There have been more than 425 million COVID-19 infections worldwide. Post-COVID illness has become a common, disabling complication of this infection. Therefore, it presents a significant challenge to global public health and economic activity. METHODS: Comprehensive clinical assessment (symptoms, WHO performance status, cognitive testing, CPET, lung function, high-resolution CT chest, CT pulmonary angiogram and cardiac MRI) of previously well, working-age adults in full-time employment was conducted to identify physical and neurocognitive deficits in those with severe or prolonged COVID-19 illness. RESULTS: 205 consecutive patients, age 39 (IQR30.0-46.7) years, 84% male, were assessed 24 (IQR17.1-34.0) weeks after acute illness. 69% reported ≥3 ongoing symptoms. Shortness of breath (61%), fatigue (54%) and cognitive problems (47%) were the most frequent symptoms, 17% met criteria for anxiety and 24% depression. 67% remained below pre-COVID performance status at 24 weeks. One third of lung function tests were abnormal, (reduced lung volume and transfer factor, and obstructive spirometry). HRCT lung was clinically indicated in <50% of patients, with COVID-associated pathology found in 25% of these. In all but three HRCTs, changes were graded 'mild'. There was an extremely low incidence of pulmonary thromboembolic disease or significant cardiac pathology. A specific, focal cognitive deficit was identified in those with ongoing symptoms of fatigue, poor concentration, poor memory, low mood, and anxiety. This was notably more common in patients managed in the community during their acute illness. CONCLUSION: Despite low rates of residual cardiopulmonary pathology, in this cohort, with low rates of premorbid illness, there is a high burden of symptoms and failure to regain pre-COVID performance 6-months after acute illness. Cognitive assessment identified a specific deficit of the same magnitude as intoxication at the UK drink driving limit or the deterioration expected with 10 years ageing, which appears to contribute significantly to the symptomatology of long-COVID.

The genome of the protist parasite Entamoeba histolytica.

Entamoeba histolytica is an intestinal parasite and the causative agent of amoebiasis, which is a significant source of morbidity and mortality in developing countries. Here we present the genome of E. histolytica, which reveals a variety of metabolic adaptations shared with two other amitochondrial protist pathogens: Giardia lamblia and Trichomonas vaginalis. These adaptations include reduction or elimination of most mitochondrial metabolic pathways and the use of oxidative stress enzymes generally associated with anaerobic prokaryotes. Phylogenomic analysis identifies evidence for lateral gene transfer of bacterial genes into the E. histolytica genome, the effects of which centre on expanding aspects of E. histolytica's metabolic repertoire. The presence of these genes and the potential for novel metabolic pathways in E. histolytica may allow for the development of new chemotherapeutic agents. The genome encodes a large number of novel receptor kinases and contains expansions of a variety of gene families, including those associated with virulence. Additional genome features include an abundance of tandemly repeated transfer-RNA-containing arrays, which may have a structural function in the genome. Analysis of the genome provides new insights into the workings and genome evolution of a major human pathogen.

Epidemiological investigation of Salmonella enterica serovar Kedougou in Thailand.

OBJECTIVE: Salmonella enterica serovar Kedougou is among the top 10 serovars reported in northern Thailand. The objective of this study was to identify risk factors associated with Salmonella Kedougou infection in Thailand and to compare the molecular types and antimicrobial resistance with Salmonella Kedougou isolates of human origin from United States and of animal origin from the United Kingdom. METHODS: Data from 13,976 Salmonella infections of which 253 were Salmonella Kedougou collected in Thailand between 2002 and 2008 were analyzed by logistic regression. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed on selected Salmonella Kedougou strains causing infections in Thailand (n = 66), and compared to isolates from the United States (n = 5) and the United Kingdom (n = 20). RESULTS: Logistic analysis revealed season (hot/dry; p = 0.023), region (northern Thailand; p < 0.001), and specimen (stool; p < 0.001) as significant risk factors associated with Salmonella Kedougou infection compared to other nontyphoid Salmonella. Of the Salmonella Kedougou isolates of human origin, 84% exhibited resistance to at least three antimicrobial classes. Three strains recovered from human stool in Thailand were resistant to third-generation cephalosporins: two harbored bla(CTX-M-63) and one bla(CMY-2). PFGE revealed 45 unique clusters. Isolates obtained from humans in Thailand and the United States presented identical PFGE profiles suggesting a travel association, whereas the majority of the animal isolates from United Kingdom clustered separately. CONCLUSIONS: This study reveals Salmonella Kedougou as a major cause of human infections in northern Thailand especially during the hot period and suggests a global spread probably due to travel. The clonal types causing infections in humans differed from those observed in animals in United Kingdom, which suggests the absence of an epidemiological link and could suggest differences in virulence. The high frequency of antimicrobial resistance, including emergence of resistance to fluoroquinolones and third-generation cephalosporins, might pose problems for treatment of infections.

Genome-wide end-sequenced BAC resources for the NOD/MrkTac() and NOD/ShiLtJ() mouse genomes.

Non-obese diabetic (NOD) mice spontaneously develop type 1 diabetes (T1D) due to the progressive loss of insulin-secreting beta-cells by an autoimmune driven process. NOD mice represent a valuable tool for studying the genetics of T1D and for evaluating therapeutic interventions. Here we describe the development and characterization by end-sequencing of bacterial artificial chromosome (BAC) libraries derived from NOD/MrkTac (DIL NOD) and NOD/ShiLtJ (CHORI-29), two commonly used NOD substrains. The DIL NOD library is composed of 196,032 BACs and the CHORI-29 library is composed of 110,976 BACs. The average depth of genome coverage of the DIL NOD library, estimated from mapping the BAC end-sequences to the reference mouse genome sequence, was 7.1-fold across the autosomes and 6.6-fold across the X chromosome. Clones from this library have an average insert size of 150 kb and map to over 95.6% of the reference mouse genome assembly (NCBIm37), covering 98.8% of Ensembl mouse genes. By the same metric, the CHORI-29 library has an average depth over the autosomes of 5.0-fold and 2.8-fold coverage of the X chromosome, the reduced X chromosome coverage being due to the use of a male donor for this library. Clones from this library have an average insert size of 205 kb and map to 93.9% of the reference mouse genome assembly, covering 95.7% of Ensembl genes. We have identified and validated 191,841 single nucleotide polymorphisms (SNPs) for DIL NOD and 114,380 SNPs for CHORI-29. In total we generated 229,736,133 bp of sequence for the DIL NOD and 121,963,211 bp for the CHORI-29. These BAC libraries represent a powerful resource for functional studies, such as gene targeting in NOD embryonic stem (ES) cell lines, and for sequencing and mapping experiments.

Control of Salmonella and Pathogenic E. coli Contamination of Animal Feed Using Alternatives to Formaldehyde-Based Treatments.

This study compared a novel non-formaldehyde combination product developed for pathogen control in animal feed Finio (A), with a panel of three commonly used organic acid feed additive products: Fysal (B), SalCURB K2 (C) and Salgard (D). Products were evaluated for their ability to reduce Salmonella Typhimurium DT104 and avian pathogenic Escherichia coli in poultry feed. A commercial layer-hen mash was treated with each product and then mixed with feed previously contaminated (via inoculated meat and bone meal) with either Salmonella or E. coli. After 24 hours at room temperature, 10 replicate samples were taken from each preparation and plate counts were performed using a selective agar. All concentrations of product A (0.5, 1.0, 1.5, 2.0 and 2.5 kg per metric tonne (MT)) plus the higher concentration of products B and D (6.0 kg MT-1) significantly reduced Salmonella counts compared with those in the untreated control group (p < 0.05). Product C did not significantly reduce levels of Salmonella under these conditions. Because of the poor recovery of E. coli, statistical comparisons for this organism were limited in scope, but only product A at the highest concentration appeared to have eliminated it.

In-depth farm investigations and an exploratory risk factor analysis for the presence of Salmonella on broiler farms in Great Britain.

Salmonella is a major cause of foodborne illness across Europe but there has been little recent research on its control in broiler production in Great Britain. Investigations of Salmonella presence on 20 broiler farms and a separate exploratory risk factor analysis involving 36 Salmonella-positive farms and 22 Salmonella-negative farms were carried out to investigate Salmonella contamination and control on broiler farms in Great Britain. Sources of Salmonella persistence on farm and potential risk factors for on-farm contamination were identified, enabling provision of up-to-date advice on Salmonella control to farmers. Twenty broiler farms across England and Wales were intensively sampled over time. Most farms were included in the study after routine testing as part of the Salmonella National Control Programmes (NCPs) identified regulated Salmonella serovars or potential associations with outbreak cases of significance for human health. Across all farms and visits, the highest proportion of Salmonella-positive samples were from areas exterior to broiler houses compared to anterooms or house interiors. Exterior Salmonella-positive samples were primarily collected from the immediate areas around the houses, with the highest proportions being from drainage, farm tracks/driveways, and pooled water. Elimination of Salmonella was variable but was most successful inside affected houses (compared to exterior areas) and for regulated Salmonella serovars under the Salmonella NCPs and high priority Salmonella strains with multi-drug resistances. It is likely that the financial and reputational concerns associated with regulated Salmonella serovars and those of greater public health significance underlie the reason that these serovars were more effectively controlled at farm level, as effective elimination of Salmonella can involve a considerable investment in infrastructure, time and resources. Without perceived direct benefits in eliminating non-regulated Salmonella serovars at farm level it can be challenging to maintain the required motivation and investment. A separate farm-level risk factor analysis was carried out using data collected from 58 broiler farms representing six GB broiler companies. Risk of testing positive for Salmonella via NCP sampling in the previous year was greater in the absence of house-specific anterooms and if at least some poultry houses were surrounded by soil/grass compared to if all were surrounded by concrete or a mixture of concrete and stones/gravel. Odds of testing positive for Salmonella in the previous year was also greater for farms whose maximum holding capacity was >100,000 birds, and farms where the usual number of visitors per day was 0-1 compared to 2-3. The analysis was exploratory and caution is required with interpretation, but results provide preliminary insight into aspects of farm management that may be important, practicable targets for Salmonella control on broiler farms in GB.

Pilot Investigation of Anti-Salmonella Antibodies in Oral Fluids from Salmonella Typhimurium Vaccinated and Unvaccinated Swine Herds.

Oral fluid (OF) can be a simple, cheap and non-invasive alternative to serum or meat juice for the diagnosis and surveillance of important pathogens in pigs. This study was conducted on four Salmonella Typhimurium-positive farrow-to-finish pig farms: two Salmonella-vaccinated (V) and two non-vaccinated (NV). Gilts and sows in the V farms were vaccinated with a live, attenuated vaccine prior to farrowing. Pooled faecal and OF samples were collected from the sows and their offspring. Salmonella was isolated according to ISO6579-1:2017. In parallel, IgG and IgA levels were assessed in OF samples using a commercial ELISA assay. Salmonella was detected in 90.9% of the pooled faecal samples from the NV farms and in 35.1% of the pooled faecal samples from the V farms. Overall, a higher prevalence was observed in the pooled faecal samples from the offspring (76.3%) compared to the sows (36.4%). IgG antibodies measured in V farms are likely to be related to vaccination, as well as exposure to Salmonella field strains. The detection of IgA antibodies in OF was unreliable with the method used. The results of this study show that IgG is the most reliable isotype for monitoring Salmonella-specific antibody immunity in vaccinated/infected animals via OF.

Semantic priming and schizotypal personality: reassessing the link between thought disorder and enhanced spreading of semantic activation.

The term schizotypy refers to a group of stable personality traits with attributes similar to symptoms of schizophrenia, usually classified in terms of positive, negative or cognitive disorganization symptoms. The observation of increased spreading of semantic activation in individuals with schizotypal traits has led to the hypothesis that thought disorder, one of the characteristics of cognitive disorganization, stems from semantic disturbances. Nevertheless, it is still not clear under which specific circumstances (i.e., automatic or controlled processing, direct or indirect semantic relation) schizotypy affects semantic priming or whether it does affect it at all. We conducted two semantic priming studies with volunteers varying in schizotypy, one with directly related prime-target pairs and another with indirectly related pairs. Our participants completed a lexical decision task with related and unrelated pairs presented at short (250 ms) and long (750 ms) stimulus onset asynchronies (SOAs). Then, they responded to the brief versions of the Schizotypal Personality Questionnaire and the Oxford-Liverpool Inventory of Feelings and Experiences, both of which include measures of cognitive disorganization. Bayesian mixed-effects models indicated expected effects of SOA and semantic relatedness, as well as an interaction between relatedness and directness (greater priming effects for directly related pairs). Even though our analyses demonstrated good sensitivity, we observed no influence of cognitive disorganization over semantic priming. Our study provides no compelling evidence that schizotypal symptoms, specifically those associated with the cognitive disorganization dimension, are rooted in an increased spreading of semantic activation in priming tasks.

Covid-19 lockdowns, income distribution, and food security: An analysis for South Africa.

Absent vaccines and pharmaceutical interventions, the only tool available to mitigate its demographic effects is some measure of physical distancing, to reduce contagion by breaking social and economic contacts. Policy makers must balance the positive health effects of strong distancing measures, such as lockdowns, against their economic costs, especially the burdens imposed on low income and food insecure households. The distancing measures deployed by South Africa impose large economic costs and have negative implications for the factor distribution of income. Labor with low education levels are much more strongly affected than labor with secondary or tertiary education. As a result, households with low levels of educational attainment and high dependence on labor income would experience an enormous real income shock that would clearly jeopardize the food security of these households. However, in South Africa, total incomes for low income households are significantly insulated by government transfer payments. From public health, income distribution and food security perspectives, the remarkably rapid and severe shocks imposed because of Covid-19 illustrate the value of having in place transfer policies that support vulnerable households in the event of 'black swan' type shocks.