Pigs in southern Italy are exposed to three ruminant pathogens: an analysis of seroprevalence and risk factors analysis study.

BACKGROUND: Pigs are susceptible to several ruminant pathogens, including Coxiella burnetti, Schmallenberg virus (SBV) and bovine viral diarrhea virus (BVDV). These pathogens have already been described in the pig population, although the dynamics of the infection and the impact on pig farms are currently unclear. The aim of this work was to evaluate the presence of these infections in the pig population of the Campania region, southern Italy, and to evaluate the risk factors associated with a greater risk of exposure. RESULTS: A total of 414 serum samples belonging to 32 herds were tested for the presence of antibodies against SBV, Coxiella, and BVD using commercial multispecies ELISA kits. SBV (5.3%) was the most prevalent pathogen, followed by Coxiella (4.1%) and BVD (3%). The risk factors included in the study (age, sex, province, farming system, ruminant density and major ruminant species) had no influence on the probability of being exposed to BVD and Coxiella, except for the location, in fact more pigs seropositive to Coxiella were found in the province of Caserta. However, the univariate analysis highlighted the influence of age, location, and sex on exposure to SBV. The subsequent multivariate analysis statistically confirmed the importance of these factors. The presence of neutralizing antibodies for SBV and BVDV, or antibodies directed towards a specific phase of infection for Coxiella was further confirmed with virus-neutralization assays and phase-specific ELISAs in a large proportion of positive samples. The presence of high neutralizing antibody titers (especially for SBV) could indicate recent exposures. Twelve of the 17 positive samples tested positive for antibodies against Coxiella phase I or II antigens, indicating the presence of both acute and chronic infections (one animal tested positive for both phases antibodies). CONCLUSIONS: Our study indicates a non-negligible exposure of pigs from southern Italy to the above pathogens. Further studies are necessary to fully understand the dynamics of these infections in pigs, the impact on productivity, and the public health consequences in the case of Coxiella.

Immune response induced by a Streptococcus suis multi-serotype autogenous vaccine used in sows to protect post-weaned piglets.

Streptococcus suis is a bacterial pathogen that causes important economic losses to the swine industry worldwide. Since there are no current commercial vaccines, the use of autogenous vaccines applied to gilts/sows to enhance transfer of passive immunity is an attractive alternative to protect weaned piglets. However, there is no universal standardization in the production of autogenous vaccines and the vaccine formulation may be highly different among licenced manufacturing laboratories. In the present study, an autogenous vaccine that included S. suis serotypes 2, 1/2, 5, 7 and 14 was prepared by a licensed laboratory and administrated to gilts using a three-dose program prior to farrowing. The antibody response in gilts as well as the passive transfer of antibodies to piglets was then evaluated. In divergence with previously published data with an autogenous vaccine produced by a different company, the increased response seen in gilts was sufficient to improve maternal antibody transfer to piglets up to 5 weeks of age. However, piglets would still remain susceptible to S. suis disease which often appears during the second part of the nursery period. Vaccination did not affect the shedding of S. suis (as well as that of the specific S. suis serotypes included in the vaccine) by either gilts or piglets. Although all antibiotic treatments were absent during the trial, the clinical protective effect of the vaccination program with the autogenous vaccine could not be evaluated, since limited S. suis cases were present during the trial, confirming the need for a complete evaluation of the clinical protection that must include laboratory confirmation of the aetiological agent involved in the presence of S. suis-associated clinical signs. Further studies to evaluate the usefulness of gilt/sow vaccination with autogenous vaccines to protect nursery piglets should be done.

Pharmaceutical activity of sappan wood extract (Caesalpinia sappan L.) for treating Escherichia coli infection in piglets.

Background: Escherichia coli infection is one of the major diarrheal diseases resulting in the loss of pigs at a young age. Aim: This research investigated the antimicrobial activity of Caesalpinia sappan wood extract against E. coli infection as an antibiotic replacement. Methods: E. coli was cultured from diarrheal piglets and then used to find the minimal inhibition concentration (MIC). Caesalpinia sappan wood extract (500 mg/kg) was used for the treatment of diarrheal piglets compared to antibiotics (enrofloxacin 5 mg/kg) by oral administration. Another three groups of diarrheal piglets were used supplemented feed with 1% and 2% extract compared with commercial feed. Subsequently, E. coli enumeration, fecal shape, fecal color, and growth rate were recorded from day 1 to 7. Results: Based on the results, C. sappan wood extract could inhibit E. coli growth at a MIC of 16-34 mg/ml. The number of colonies did not significantly differ between C. sappan wood extract and enrofloxacin treatment groups. A supplemented feed with 1% and 2% C. sappan wood extract could improve the fecal shape and fecal score compared to the control group, albeit only in suckling pigs. There were significant differences from the control group on days 4, 5, 6, and 7 (p < 0.05). However, the average daily gain did not significantly differ among the three groups. Conclusion: The results indicate that C. sappan wood extract could improve diarrheal signs in suckling pigs and can be used as a replacement for antibiotics for organic pig production.

Effects of dietary yeast mannan-rich fraction supplementation on growth performance, intestinal morphology, and lymphoid tissue characteristics in weaned piglets challenged with Escherichia Coli F4.

We evaluated the effects of supplementing yeast mannan-reach-fraction on growth performance, jejunal morphology and lymphoid tissue characteristics in weaned piglets challenged with E. Coli F4. A total of 20 crossbred piglets were used. At weaning, piglets were assigned at random to one of four groups: piglets challenged and fed the basal diet supplemented with yeast mannan-rich fraction (C-MRF, n = 5); piglets challenged and fed the basal diet (C-BD, n = 5); piglets not challenged and fed the basal diet supplemented with yeast mannan-rich fraction (NC-MRF, n = 5), and piglets not challenged and fed the basal diet (NC-BD). Each dietary treatment had five replicates. On days 4, 5 and 10, piglets were orally challenged with 108 CFU/mL of E. Coli F4. C-MRF piglets had higher BW (p = 0.002; interactive effect) than C-BD piglets. C-MRF piglets had higher (p = 0.02; interactive effect) ADG in comparison with C-BD piglets. C-MRF piglets had higher (p = 0.04; interactive effect) ADFI than C-BD piglets. The diameter of lymphoid follicles was larger (p = 0.010; interactive effect) in the tonsils of C-MRF piglets than C-BD piglets. Lymphoid cells proliferation was greater in the mesenteric lymphnodes and ileum (p = 0.04 and p = 0.03, respectively) of C-MRF piglets. A reduction (p > 0.05) in E. Coli adherence in the ileum of piglets fed MRF was observed. In conclusion, the results of the present study demonstrate that dietary yeast mannan-rich fraction supplementation was effective in protecting weaned piglets against E. Coli F4 challenge.

Emergence of Group B Streptococcus Disease in Pigs and Porcupines, Italy.

We describe group B Streptococcus linked to disease in farmed pigs and wild porcupines in Italy. Occurrence in pigs was attributed to transmission from nonpasteurized bovine milk whey. Antimicrobial-resistance profiles in isolates from porcupines suggest no common source of infection. Our findings expand the known host range for group B Streptococcus disease.

Molecular profile and epidemiological traits of Streptococcus suis isolated from diseased pigs in western Canada reveal multiple-serotype infection: Implications for disease control.

Objective: Streptococcus suis is a major agent of disease in modern swine operations, linked to increased mortality, treatment costs, and secondary infections. Although it is ubiquitous in swine, only a fraction of pigs develop clinical disease. The goals of this study were to profile isolates obtained from diseased pigs in western Canada and to investigate potential associations with disease severity. Procedure: Isolates of S. suis (n = 128) from 75 diagnostic submission and 63 premises were paired with epidemiological surveys completed by submitting practitioners (n = 22). Whole-genome sequencing was used to type isolates. Results: The most prevalent serotypes identified were 1/2 (7.8%, 10/128), 2 (9.3%, 12/128), 3 (9.3%, 12/128), and 7 (7.8%, 10/128); and sequence types 28 (17%, 23/128) and 839 (14%, 19/128). There was no association between serotype or sequence type and organ source or barn location. Approximately 74% (14/19) of the premises had diseased animals colonized by > 1 S. suis serotype, but only 1 pig was simultaneously infected with multiple serotypes and sequence types. Serotype distribution from diseased pigs in western Canada differed from that of those in other geographic regions. Conclusion: Infection of diseased pigs by multiple serotypes should be considered when disease control strategies are implemented. No association between S. suis type and isolation organ was identified.

Le profil moléculaire et les caractéristiques épidémiologiques de Streptococcus suis isolés de porcs malades dans l'ouest du Canada révèlent une infection à sérotypes multiples : implications pour la maitrise de la maladie. Objectif: Streptococcus suis est un agent pathogène majeur dans les exploitations porcines modernes, lié à une mortalité accrue, aux coûts de traitement et aux infections secondaires. Bien qu'elle soit omniprésente chez le porc, seule une fraction des porcs développe une maladie clinique. Les objectifs de cette étude étaient de dresser le profil des isolats obtenus à partir de porcs malades dans l'ouest du Canada et d'étudier les associations potentielles avec la gravité de la maladie. Procédure: Des isolats de S. suis (n = 128) provenant de 75 soumissions pour diagnostic et de 63 sites ont été associés à des enquêtes épidémiologiques réalisées auprès des praticiens soumettant les échantillons (n = 22). Le séquençage du génome entier a été utilisé pour typer les isolats. Résultats: Les sérotypes les plus répandus identifiés étaient 1/2 (7,8 %, 10/128), 2 (9,3 %, 12/128), 3 (9,3 %, 12/128) et 7 (7,8 %, 10/128); et les types de séquence 28 (17 %, 23/128) et 839 (14 %, 19/128). Il n'y avait aucune association entre le sérotype ou le type de séquence et la source d'organes ou l'emplacement de la ferme. Environ 74 % (14/19) des exploitations abritaient des animaux malades colonisés par > 1 sérotype de S. suis, mais 1 seul porc était infecté simultanément par plusieurs sérotypes et types de séquences. La répartition des sérotypes chez les porcs malades de l'ouest du Canada différait de celle des porcs d'autres régions géographiques. Conclusion: L'infection des porcs malades par plusieurs sérotypes doit être envisagée lors de la mise en oeuvre de stratégies de maitrise de la maladie. Aucune association entre le type de S. suis et l'organe d'isolement n'a été identifiée.(Traduit par Dr Serge Messier).

Streptococcus suis serotype 4: a population with the potential pathogenicity in humans and pigs.

Streptococcus suis is a major bacterial pathogen in pigs and an emerging zoonotic pathogen. Different S. suis serotypes exhibit diverse characteristics in population structure and pathogenicity. Surveillance data highlight the significance of S. suis serotype 4 (SS4) in swine streptococcusis, a pathotype causing human infections. However, except for a few epidemiologic studies, the information on SS4 remains limited. In this study, we investigated the population structure, pathogenicity, and antimicrobial characteristics of SS4 based on 126 isolates, including one from a patient with septicemia. We discovered significant diversities within this population, clustering into six minimum core genome (MCG) groups (1, 2, 3, 4, 7-2, and 7-3) and five lineages. Two main clonal complexes (CCs), CC17 and CC94, belong to MCG groups 1 and 3, respectively. Numerous important putative virulence-associated genes are present in these two MCG groups, and 35.00% (7/20) of pig isolates from CC17, CC94, and CC839 (also belonging to MCG group 3) were highly virulent (mortality rate ≥ 80%) in zebrafish and mice, similar to the human isolate ID36054. Cytotoxicity assays showed that the human and pig isolates of SS4 strains exhibit significant cytotoxicity to human cells. Antimicrobial susceptibility testing showed that 95.83% of strains isolated from our labs were classified as multidrug-resistant. Prophages were identified as the primary vehicle for antibiotic resistance genes. Our study demonstrates the public health threat posed by SS4, expanding the understanding of SS4 population structure and pathogenicity characteristics and providing valuable information for its surveillance and prevention.

Method for quantifying the Pasteurella multocida antigen adsorbed on aluminum hydroxide adjuvant in swine atrophic rhinitis vaccine.

Swine atrophic rhinitis is a disease caused by Pasteurella multocida and Bordetella bronchiseptica that affects pigs. Inactivated vaccines containing the toxins produced by Pasteurella multocida and Bordetella bronchiseptica have been widely used for the prevention of swine atrophic rhinitis. The efficacy of a vaccine is correlated with the amount of antigen present; however, the protective toxin of P. multocida bound to aluminum hydroxide, which is used as an adjuvant, can hinder the monitoring of the antigen concentration in the vaccine. This study assessed the applicability of a dot immunoassay as an antigen quantification method using monoclonal antibodies. This quantification method was able to detect the antigen with high specificity and sensitivity even when the antigen was bound to the adjuvant, and its application to vaccine products revealed a correlation between the amount of antigen present in the vaccine and the neutralizing antibody titers induced in pigs. The antigen quantification method presented in this study is a simple and sensitive assay capable of quantifying the amount of antigen present in a vaccine that can be used as an alternative quality control measure.

Multidrug resistance in Salmonella isolates of swine origin: mobile genetic elements and plasmids associated with cephalosporin resistance with potential transmission to humans.

The emergence of foodborne Salmonella strains carrying antimicrobial resistance (AMR) in mobile genetic elements (MGE) is a significant public health threat in a One Health context requiring continuous surveillance. Resistance to ciprofloxacin and cephalosporins is of particular concern. Since pigs are a relevant source of foodborne Salmonella for human beings, we studied transmissible AMR genes and MGE in a collection of 83 strains showing 9 different serovars and 15 patterns of multidrug resistant (MDR) previously isolated from pigs raised in the conventional breeding system of Northern Spain. All isolates were susceptible to ciprofloxacin and three isolates carried blaCMY-2 or blaCTX-M-9 genes responsible for cefotaxime resistance. Filter mating experiments showed that the two plasmids carrying blaCTX-M-9 were conjugative while that carrying blaCMY-2 was self-transmissible by transformation. Whole-genome sequencing and comparative analyses were performed on the isolates and plasmids. The IncC plasmid pSB109, carrying blaCMY-2, was similar to one found in S. Reading from cattle, indicating potential horizontal transfer between serovars and animal sources. The IncHI2 plasmids pSH102 in S. Heidelberg and pSTM45 in S. Typhimurium ST34, carrying blaCTX-M-9, shared similar backbones and two novel "complex class 1 integrons" containing different AMR and heavy metal genes. Our findings emphasize the importance of sequencing techniques to identify emerging AMR regions in conjugative and stable plasmids from livestock production. The presence of MGE carrying clinically relevant AMR genes raises public health concerns, requiring monitoring to mitigate the emergence of bacteria carrying AMR genes and subsequent spread through animals and food.IMPORTANCEThe emergence of foodborne Salmonella strains carrying antimicrobial resistance (AMR) in mobile genetic elements (MGE) is a significant public health threat in a One Health context. Since pigs are a relevant source of foodborne Salmonella for humans, in this study, we investigate different aspects of AMR in a collection of 83 Salmonella showing nine different serovars and 15 patterns of multidrug resistant (MDR) isolated from pigs raised in the conventional breeding system. Our findings emphasize the importance of sequencing techniques to identify emerging AMR regions in conjugative and stable plasmids from livestock production. The presence of MGE carrying clinically relevant AMR genes raises public health concerns, requiring monitoring to mitigate the emergence of bacteria carrying AMR genes and subsequent spread through animals and food.

Protecting the piglet gut microbiota against ETEC-mediated post-weaning diarrhoea using specific binding proteins.

Post-weaning diarrhoea (PWD) in piglets presents a widespread problem in industrial pig production and is often caused by enterotoxigenic E. coli (ETEC) strains. Current solutions, such as antibiotics and medicinal zinc oxide, are unsustainable and are increasingly being prohibited, resulting in a dire need for novel solutions. Thus, in this study, we propose and evaluate a protein-based feed additive, comprising two bivalent heavy chain variable domain (VHH) constructs (VHH-(GGGGS)3-VHH, BL1.2 and BL2.2) as an alternative solution to manage PWD. We demonstrate in vitro that these constructs bind to ETEC toxins and fimbriae, whilst they do no affect bacterial growth rate. Furthermore, in a pig study, we show that oral administration of these constructs after ETEC challenge reduced ETEC proliferation when compared to challenged control piglets (1-2 log10 units difference in gene copies and bacterial count/g faeces across day 2-7) and resulted in week 1 enrichment of three bacterial families (Prevotellaceae (estimate: 1.12 ± 0.25, q = 0.0054), Lactobacillaceae (estimate: 2.86 ± 0.52, q = 0.0012), and Ruminococcaceae (estimate: 0.66 ± 0.18, q = 0.049)) within the gut microbiota that appeared later in challenged control piglets, thus pointing to an earlier transition towards a more mature gut microbiota. These data suggest that such VHH constructs may find utility in industrial pig production as a feed additive for tackling ETEC and reducing the risk of PWD in piglet populations.

Tuberculosis in Wild Pigs from Argentina.

Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex (MTC) and non-tuberculous Mycobacteria (NTM), may infect wild and domestic mammals, including humans. Although cattle are the main hosts and spreaders of M. bovis, many wildlife hosts play an important role worldwide. In Argentina, wild boar and domestic pigs are considered important links in mammalian tuberculosis (mTB) transmission. The aim of this work was to investigate the presence of M. bovis in wild pigs from different regions of Argentina, to characterize isolates of M. bovis obtained, and to compare those with other previously found in vertebrate hosts. A total of 311 samples from wild pigs were obtained, and bacteriological culture, molecular identification and genotyping were performed, obtaining 63 isolates (34 MTC and 29 NTM). Twelve M. bovis spoligotypes were detected. Our findings suggest that wild pigs have a prominent role as reservoirs of mTB in Argentina, based on an estimated prevalence of 11.2 ± 1.8% (95% CI 8.0-14.8) for MTC and the frequency distribution of spoligotypes shared by cattle (75%), domestic pigs (58%) and wildlife (50%). Argentina has a typical scenario where cattle and pigs are farm-raised extensively, sharing the environment with wildlife, creating conditions for effective transmission of mTB in the wildlife-livestock-human interface.

Resistome, Virulome, and Clonal Variation in Methicillin-Resistant Staphylococcus aureus (MRSA) in Healthy Swine Populations: A Cross-Sectional Study.

This cross-sectional study investigates the methicillin-resistant Staphylococcus aureus (MRSA): its prevalence, antimicrobial resistance, and molecular characteristics in healthy swine populations in central Portugal. A total of 213 samples were collected from pigs on twelve farms, and MRSA prevalence was assessed using selective agar plates and confirmed via molecular methods. Antimicrobial susceptibility testing and whole genome sequencing (WGS) were performed to characterize resistance profiles and genetic determinants. Among the 107 MRSA-positive samples (83.1% prevalence), fattening pigs and breeding sows exhibited notably high carriage rates. The genome of 20 isolates revealed the predominance of the ST398 clonal complex, with diverse spa types identified. Antimicrobial susceptibility testing demonstrated resistance to multiple antimicrobial agents, including penicillin, cefoxitin, and tetracycline. WGS analysis identified a diverse array of resistance genes, highlighting the genetic basis of antimicrobial resistance. Moreover, virulence gene profiling revealed the presence of genes associated with pathogenicity. These findings underscore the significant prevalence of MRSA in swine populations and emphasize the need for enhanced surveillance and control measures to mitigate zoonotic transmission risks. Implementation of prudent antimicrobial use practices and targeted intervention strategies is essential to reducing MRSA prevalence and safeguarding public health. Continued research efforts are warranted to elucidate transmission dynamics and virulence potential, ultimately ensuring food safety and public health protection.

Differential antigenicity of individual Mycoplasma hyorhinis variable lipoproteins.

The Mycoplasma hyorhinis (Mhr) variable lipoprotein (Vlp) family, comprising Vlps A, B, C, D, E, F, and G, are highly variable in expression, size, and cytoadhesion capabilities across Mhr strains. The 'Vlp system' plays a crucial role in cytoadhesion, immune evasion, and in eliciting a host immunologic response. This pilot study described the development of Vlp peptide-based ELISAs to evaluate the antigenic reactivity of individual Vlps against Mhr antisera collected throughout a longitudinal study focused on Mhr strain 38983, reproducing Mhr-associated disease under experimental conditions. Specifically, serum samples were collected at day post-inoculation 0, 7, 10, 14, 17, 21, 24, 28, 35, 42, 49, and 56 from Mhr- and mock (Friis medium)-inoculated cesarean-derived, colostrum-deprived pigs. Significant Mhr-specific IgG responses were detected at specific time points throughout the infection, with some variations for each Vlp. Overall, individual Vlp ELISAs showed consistently high accuracy rates, except for VlpD, which would likely be associated with its expression levels or the anti-Vlp humoral immune response specific to the Mhr strain used in this study. This study provides the basis and tools for a more refined understanding of these Vlp- and Mhr strain-specific variations, which is foundational in understanding the host immune response to Mhr.

Histo-Blood Group Antigen-Producing Bacterial Cocktail Reduces Rotavirus A, B, and C Infection and Disease in Gnotobiotic Piglets.

The suboptimal performance of rotavirus (RV) vaccines in developing countries and in animals necessitates further research on the development of novel therapeutics and control strategies. To initiate infection, RV interacts with cell-surface O-glycans, including histo-blood group antigens (HBGAs). We have previously demonstrated that certain non-pathogenic bacteria express HBGA- like substances (HBGA+) capable of binding RV particles in vitro. We hypothesized that HBGA+ bacteria can bind RV particles in the gut lumen protecting against RV species A (RVA), B (RVB), and C (RVC) infection in vivo. In this study, germ-free piglets were colonized with HBGA+ or HBGA- bacterial cocktail and infected with RVA/RVB/RVC of different genotypes. Diarrhea severity, virus shedding, immunoglobulin A (IgA) Ab titers, and cytokine levels were evaluated. Overall, colonization with HBGA+ bacteria resulted in reduced diarrhea severity and virus shedding compared to the HBGA- bacteria. Consistent with our hypothesis, the reduced severity of RV disease and infection was not associated with significant alterations in immune responses. Additionally, colonization with HBGA+ bacteria conferred beneficial effects irrespective of the piglet HBGA phenotype. These findings are the first experimental evidence that probiotic performance in vivo can be improved by including HBGA+ bacteria, providing decoy epitopes for broader/more consistent protection against diverse RVs.

Centralized industrialization of pork in Europe and America contributes to the global spread of Salmonella enterica.

Salmonella enterica causes severe food-borne infections through contamination of the food supply chain. Its evolution has been associated with human activities, especially animal husbandry. Advances in intensive farming and global transportation have substantially reshaped the pig industry, but their impact on the evolution of associated zoonotic pathogens such as S. enterica remains unresolved. Here we investigated the population fluctuation, accumulation of antimicrobial resistance genes and international serovar Choleraesuis transmission of nine pig-enriched S. enterica populations comprising more than 9,000 genomes. Most changes were found to be attributable to the developments of the modern pig industry. All pig-enriched salmonellae experienced host transfers in pigs and/or population expansions over the past century, with pigs and pork having become the main sources of S. enterica transmissions to other hosts. Overall, our analysis revealed strong associations between the transmission of pig-enriched salmonellae and the global pork trade.

Molecular characterization of Escherichia coli virulence markers in neonatal and postweaning piglets from major pig-producing districts of Uganda.

BACKGROUND: Piggery production is highly constrained by diseases, with diarrhoea in piglets being a major cause of economic losses to smallholder farmers in Uganda. Enterotoxigenic Escherichia coli (ETEC) is thought to be one of the major etiologies of this diarrhoea. A cross-sectional study was carried out in two high pig-producing districts of Uganda with the aim of determining the significance of piglet diarrhoea and the pathogenic determinants of causative E. coli. METHODOLOGY: A total of 40 households with piglets were visited in each district for a questionnaire survey and faecal sample collection. The questionnaire-based data collected included; demographic data and pig management practices. E. coli were isolated from diarrheic (43) and non-diarrheic (172) piglets and were subjected to antimicrobial susceptibility testing against nine commonly used antimicrobial agents. The E. coli isolates were further screened for the presence of 11 enterotoxin and fimbrial virulence gene markers using multiplex polymerase chain reaction. Data entry, cleaning, verification and descriptive statistics were performed using Microsoft Excel. Statistical analysis to determine any association between the presence of virulence markers and diarrhea in piglets was done using SPSS software (Version 23), with a p value of less than 0.05 taken as a statistically significant association. RESULTS: Escherichia coli were recovered from 81.4% (175/215) of the faecal samples. All the isolates were resistant to erythromycin, and most showed high resistance to tetracycline (71%), ampicillin (49%), and trimethoprim sulfamethoxazole (45%). More than half of the isolates (58.3%) carried at least one of the 11 virulence gene markers tested. EAST1 was the most prevalent virulence marker detected (35.4%), followed by STb (14.8%). Expression of more than one virulence gene marker was observed in 6.2% of the isolates, with the EAST1/STa combination being the most prevalent. Three adhesins; F17 (0.6%), F18 (6.3%) and AIDA-I (0.6%) were detected, with F18 being the most encountered. There was a statistically significant association between the occurrence of piglet diarrhoea and the presence of the AIDA-1 (p value = 0.037) or EAST1 (p value = 0.011) gene marker among the isolates. CONCLUSION AND RECOMMENDATION: The level of antimicrobial resistance among E. coli isolates expressing virulence markers were high in the sampled districts. The study established a significant association between presence of EAST1 and AIDA-I virulence markers and piglet diarrhea. Further studies should be carried out to elucidate the main adhesins borne by these organisms in Uganda and the actual role played by EAST1 in the pathogenesis of the infection since most isolates expressed this gene.

Redox balance and immunity of piglets pre- and post-E. coli challenge after treatment with hemp or fish oil, and vitamin E.

This study investigated the influence of polyunsaturated fatty acid composition and vitamin E supplementation on oxidative status and immune responses in weanling piglets pre- and post-E. coli challenge. Suckling piglets (n = 24) were randomly selected from two litters for an oral supplementation (1 mL/day) with fish oil or hemp oil and vitamin E supplementation (60 mg natural vitamin E/mL oil) from day 10 to 28 of age. At day 29 and 30 of age, each piglet was orally inoculated with 6.7 × 108 and 3.96 × 108 CFU of F4 and F18 E. coli, respectively. Blood was sampled from all piglets on day 28 before E. coli challenge and on day 35 of age to investigate immunological and oxidative stress markers in plasma. One week after weaning and exposure to E. coli, a general reduction in the α-tocopherol concentration and activity of GPX1 was obtained. Vitamin E supplementation lowered the extent of lipid peroxidation and improved the antioxidative status and immune responses after E. coli challenge. Hemp oil had the greatest effect on antioxidant enzyme activity. Provision of hemp oil and vitamin E to suckling piglets may reduce the incidence of post-weaning diarrhea.