muramidase and Swine-Diseases

To test the hypothesis that variation in ability to respond immunologically correlates with health, Yorkshire pigs were bred for high (HIR) and low (LIR) antibody (Ab) and cell-mediated immune response (CMI). Selection was based on standardized measures of Ab (secondary response to hen egg white lysozyme, serum IgG concentration) and CMI (cutaneous delayed-type hypersenstivity to purified protein derivative of tuberculin after immunization with bacillus Calmette-Guérin and in vitro lymphocyte response to Con-A). Differences in Ab and CMI by line were not restricted to the antigens used in the selection. Antibody response to vaccines was highest in HIR and non-responders were restricted to LIR pigs. The HIR pigs had the best rate of weight gain. After infection with Mycoplasma hyorhinis, HIR developed more severe arthritis and less polyserositis. Differences were associated with variation in cytokine message in joint-related cells. Following exposure to attenuated transmissible gastroenteritis virus, natural killer cells of the LIR pigs but not of HIR or control lines, were unresponsive. Genetic selection for Ab and CMI may provide health and productivity advantages and complement traditional health-maintenance methods.

Topics: Animals; Antibody Formation; Female; Genetic Predisposition to Disease; Hypersensitivity, Delayed; Immunity, Cellular; Immunoglobulin G; Male; Muramidase; Mycoplasma; Mycoplasma Infections; Selection, Genetic; Swine; Swine Diseases

Glucocorticoids play a role in the origin of the features of the metabolic diseases. Alpha-ketoglutarate (AKG) is defined as glutamine homologue and derivative, conditionally an essential amino acid. In the liver, glutamine serves as a precursor for ureagenesis, gluconeogenesis and acute phase protein synthesis The aim of the study was to determine the effect of AKG administered to piglets prenatally exposed to dexamethasone, on the structure of the liver and its metabolic function. Sows were administered with dexamethasone (3 mg/sow/48 h) from day 70 of pregnancy to the parturition, and then after the birth, the piglets were divided into the group administered with AKG (0.4 g/kg body weight) or physiological saline. Biochemical markers, lysozyme and ceruloplasmin serum activities, concentrations of selected free amino acids, macro- and microelements and histomorphometry of the liver tissue were determined. The total cholesterol concentrations in the sows and their newborns from the Dex groups were higher by 72% and 64%, respectively, compared with the control groups. Triacylglycerol concentration was higher by 50% in sows from the Dex group and 55% in the new-born piglets. Alpha-ketoglutarate administered to the piglets after prenatal influence of dexamethasone lowered the total cholesterol concentration by 40%, and enhanced aspartate by 41%, serine by 76%, glutamate by 105%, glutamine by 36%, glycine by 53% and arginine by 105%, as well as methionine and cystathionine, but increased the sulphur concentration compared with the control (p < 0.01). Intracellular space D decreased after AKG administration in comparison with the piglets from Dex/Control group not treated with AKG. Postnatal administration of AKG had a protective effect on liver structure, and lowered the total cholesterol concentration in piglets prenatally exposed to dexamethasone, and also influenced selected macro- and microelement serum concentrations and amino acids plasma concentration.

Topics: Amino Acids; Animals; Animals, Newborn; Body Weight; Ceruloplasmin; Cholesterol; Dexamethasone; Female; Fetal Development; Glucocorticoids; Ketoglutaric Acids; Liver; Muramidase; Pregnancy; Prenatal Exposure Delayed Effects; Swine; Swine Diseases

Diarrhea remains one of the leading causes of morbidity and mortality globally, with enterotoxigenic Escherichia coli (ETEC) constituting a major causative pathogen. The development of alternative treatments for diarrhea that do not involve chemotherapeutic drugs or result in antibiotic resistance is critical. Considering that lysozyme is a naturally occurring antimicrobial peptide, in a previous study we developed a transgenic pig line that expresses recombinant human lysozyme (hLZ) in its milk. In the present study, we examined the protective effects of the consumption of this milk against ETEC infection in neonatal piglets. We found that consuming hLZ milk facilitated faster recovery from infection and decreased mortality and morbidity following an ETEC oral inoculation or infection acquired by contact-exposure. The protective effect of hLZ was associated with the enrichment of intestinal bacteria that improve gut health, such as Lactobacillus, and the enhancement of the mucosal IgA response to the ETEC-induced diarrhea. Our study revealed potential protective mechanisms underlying the antimicrobial activity of human lysozyme, validating the use of lysozyme as an effective preventive measure for diarrhea.

Topics: Animals; Animals, Genetically Modified; Animals, Newborn; Anti-Bacterial Agents; Diarrhea; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Female; Intestinal Diseases; Milk; Muramidase; Swine; Swine Diseases

Lawsonia intracellularis is known to cause proliferative enteropathy (PE), one of the economically most important swine diseases with global distribution. Not unlike other enteric diseases, PE is a frequent indication for antibiotic therapy. However, their unjustified use leads to an emerging problem - antimicrobial resistance. Thus, the aim of this research was to assess if a phytogenic additive may replace antibiotics in the control of PE in 144 weaned piglets (72 treated and 72 controls) naturally infected with L. intracellularis. The quantity of L. intracellularis faecal shedding was monitored by real-time polymerase chain reaction (PCR) assay in faecal samples on day 0, 14 and 28, whilst the level of the ileum damage was determined by immunohistochemistry (IHC) assay performed on gut sections. Real-time PCR assay revealed that cycle-threshold (Ct) values in the treatment group increased significantly over time and were higher than in the control. These results indicate that the use of the phytogenic additive decreases the faecal excretion of L. intracellularis both throughout the experiment and in comparison to the control. The expression of the L. intracellularis antigen in IHC assay was lower in treated animals, implying that the additive leads to the decrease in the pathogen quantity in the ileum. Significantly higher feed conversion ratio was recorded in the treatment group. The results indicate that the phytogenic additive may be beneficial in the control of PE, but additional research is necessary to assess its use in various pig categories and define the optimum concentrations.

Topics: Animal Feed; Animals; Asymptomatic Infections; Desulfovibrionaceae Infections; Diet; Dietary Supplements; Female; Lawsonia Bacteria; Muramidase; Niacinamide; Oils, Volatile; Plant Extracts; Serbia; Swine; Swine Diseases

Topics: Animals; Bacterial Proteins; Humans; Muramidase; Streptococcal Infections; Streptococcus suis; Swine Diseases; Virulence

Topics: Animal Feed; Animals; Animals, Genetically Modified; Animals, Newborn; Bacteroidetes; Diet; Disease Models, Animal; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Feces; Gastrointestinal Microbiome; Goats; Intestinal Diseases; Intestines; Milk; Muramidase; Swine; Swine Diseases

The objective of this study was to determine the effect of lysozyme and antibiotics on zoonotic pathogen shedding in faeces from nursery pigs housed without and with an indirect disease challenge.. Two replicates of approximately 650 pigs each were weaned and randomly assigned to one of 24 pens in either a nursery room that had been fully disinfected or a nursery room left unclean. Pigs were randomly assigned to control diet (Control), control diet + antibiotics (Antibiotic; chlortetracycline and tiamulin), or control diet + lysozyme (Lysozyme; 100 mg kg(-1) diet). Rectal swab samples were collected on day 0 and 28 of treatment, and enriched and cultured for Campylobacter spp. and shiga-toxigenic Escherichia coli (STEC). Enrichments from rectal swab samples also were analysed for presence of enterohaemorrhagic E. coli (EHEC) virulence genes (hlyA, eae, stx1 and stx2). Room hygiene had little effect on day 28 results. Percentage of samples culture positive for Campylobacter spp. was lowest for lysozyme diets (P < 0·01), but similar for control and antibiotic diets (43·2, 83·7, and 84·8 respectively). Diet had little effect on the EHEC virulence genes hlyA or eae (P > 0·1), but there was a tendency for fewer samples positive for stx1/stx2 in antibiotic or lysozyme diet groups (P < 0·07) compared to control diet (1·2, 2·1 and 5·8% respectively). Salmonella spp. and specific STEC types tested were rarely detected in the study.. In nursery swine, room hygiene had little effect on pathogen shedding. Dietary chlortetracycline and tiamulin did not reduce pathogen shedding but dietary lysozyme reduced faecal shedding of Campylobacter.. Lysozyme can effectively replace antibiotics in the diet of nursery swine and can be effective for pathogen control.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Campylobacter; Feces; Muramidase; Salmonella; Shiga-Toxigenic Escherichia coli; Swine; Swine Diseases

Lysozyme is a low-molecular-weight protein with antimicrobial properties. An experiment was conducted to investigate the response of piglets receiving a water-soluble lysozyme supplement [Entegard (EG), Neova Technologies Inc., Abbotsford, British Columbia, Canada; 4,000 lysozyme units/mg] after oral challenge with enterotoxigenic Escherichia coli (ETEC). A total of 36 individually housed weanling pigs were randomly allotted to 1 of the 4 treatments, with 9 replicates per treatment. Treatments were a control (CONT, no additive), antibiotic (AB; 2.5 g/kg of feed of antibiotic with chlortetracycline, sulfamethazine, and penicillin), and EG delivered in the drinking water at concentrations of 0.1% (EG1) and 0.2% (EG2). All pigs received a basal diet similar in composition and nutrients, except for pigs receiving the AB diet, which had an added antibiotic. Pigs were acclimated to treatments for a 7-d period to monitor growth performance. On d 8, blood samples were collected from each pig to obtain serum, and each pig was gavaged with 6 mL (2 × 10(9) cfu/mL) of ETEC solution. Pigs were monitored for another 7 d to assess incidences of diarrhea and growth performance, and then all pigs were killed to obtain intestinal tissue and digesta samples. Treatments did not influence growth performance throughout the study. Greater ETEC counts were observed in the ileal mucosal scrapings (P = 0.001) and colonic digesta (P = 0.025) of pigs in the CONT group compared with pigs in the AB and EG1 groups. Pigs receiving AB and EG1 had greater (P < 0.05) small intestinal weights and ileal villus heights than pigs receiving CONT; however, the ileal villus height-to-crypt depth ratio was greater in pigs fed the AB diet (1.69) compared with those fed the CONT diet (1.34), whereas pigs receiving EG1 were intermediate. Pigs in the EG1 group showed greater (P < 0.001) serum tumor necrosis factor α and IL-6 concentrations before ETEC challenge; however, at 7 d postchallenge, pigs receiving EG2 showed the least (P < 0.05) circulating tumor necrosis factor α and IL-6 concentrations. Overall, better intestinal growth and development, as well as decreased ETEC counts on the intestinal mucosa and serum proinflammatory cytokines, suggest that EG can maintain gut health and function in piglets commensurate with antibiotics. However, it is noteworthy that at the largest dose tested, EG seemed to have a dramatic effect on proinflammatory cytokines but had a minimal or no effect on the other r

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Dietary Supplements; Dose-Response Relationship, Drug; Enterotoxigenic Escherichia coli; Escherichia coli Infections; Interleukin-6; Intestine, Small; Muramidase; Random Allocation; Swine; Swine Diseases; Tumor Necrosis Factor-alpha; Water; Weaning

Streptococcus suis isolates from diseased pigs were examined for susceptibility to nine antimicrobials, possession of virulence-associated factors (VFs), and distribution of serotypes. The association between antimicrobial resistance (AMR) and serotypes as well as VFs was subsequently assessed. Among the isolates investigated, serotype 2 (66.04%) was mostly prevalent, followed by serotypes 1 (23.27%), 9 (1.26%), and 7 (0.63%), whereas 14 isolates were untypable by the polymerase chain reaction typing method used. Analysis with pulsed-field gel electrophoresis revealed the isolates had diverse DNA macrorestriction patterns. The frequency of antimicrobial resistance among the S. suis isolates was higher than that reported from other countries. It is notable that multiple antimicrobial resistance (three or more antimicrobials) was observed with 98.73% of the S. suis isolates, and the dominant resistance phenotype was erythromycin-tilmicosin-clindamycin-chloramphenicol-levofloxacin-ceftiofur-kanamycin-tetracycline-penicillin (35.85%). The most prevalent VFs were those encoded by muramidase-released protein (61.64%), followed by suilysin (56.60%) and extracellular factor (46.54%). Presence of VFs and the possession of certain AMR phenotypes were significantly associated as determined by statistical analysis. Together, these findings indicate that the clinical S. suis isolates obtained from diseased pigs in China are genetically diverse, are resistant to multiple antibiotics of clinical importance, and carry known virulence factors.

Topics: Animals; Anti-Bacterial Agents; China; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Hemolysin Proteins; Muramidase; Phenotype; Serotyping; Streptococcus suis; Swine; Swine Diseases; Virulence Factors

Streptococcus suis is an important swine pathogen and a zoonotic agent. Differences in virulence have been noted among the 33 described serotypes, serotype 2 being considered the most virulent. In this study, we aimed at assessing the serotype distribution and the production of virulence-associated markers by strains recovered from diseased pigs in the United States (U.S.). Results showed that among the 100 strains evaluated, serotype 3 (20% of the isolates) and serotype 2 (17%) were the most prevalent. We then investigated the presence in these isolates of the genes sly, epf and mrp, encoding the virulence-associated markers suilysin (SLY), extracellular factor (EF) and muramidase-released (MRP) protein, respectively. The effective production of the markers by the strains was also verified. Results showed that the presence of the gene did not always correlate with actual expression of the respective protein. In the case of MRP, this was due, in most cases, to frameshift mutations at the 5' end of the gene resulting in premature stop codons. The most prevalent phenotypes among U.S. strains were MRP(+)EF(-)SLY(-) (40%) and MRP(-)EF(-)SLY(+) (35%). Serotype distribution greatly differed from that reported in several European countries, as did the production of virulence markers, particularly for serotype 2. On the other hand, our results for the U.S. S. suis isolates are similar to those reported for Canadian strains, suggesting a common status in North America.

Topics: Animals; Bacterial Proteins; Hemolysin Proteins; Muramidase; Phenotype; Serotyping; Streptococcal Infections; Streptococcus suis; Sus scrofa; Swine Diseases; United States; Virulence; Virulence Factors

Nineteen Streptococccus suis type 2 isolates that had been analyzed previously for hemolysin production, ribotype, and virulence in pigs were examined for presence of the gene coding for suilysin by PCR amplification, and southern blot and hybridization techniques. Based on southern blot and hybridization analysis, all isolates tested contained at least a portion of the suilysin gene. PCR amplification of the entire gene resulted in gene fragments from five of the seven highly virulent isolates and none of the moderately virulent or avirulent isolates. Additional PCR analysis showed that mutation or deletions at the 5' end of the suilysin gene in the less virulent isolates prevented amplification of the sly gene fragment from those isolates. The MRP+ (muramidase-released protein) EF+ (extracellular protein) phenotype was also expressed by the same five highly virulent/sly+ isolates.

Topics: Animals; Bacterial Proteins; Blotting, Western; Electrophoresis, Polyacrylamide Gel; Gene Expression Regulation, Bacterial; Hemolysin Proteins; Muramidase; Organic Chemicals; Polymerase Chain Reaction; Streptococcal Infections; Streptococcus suis; Swine; Swine Diseases

The origin of pulmonary multinucleate giant cells (MGC) in porcine dermatosis vegetans was studied in six Norwegian Landrace pigs ages 4 (male), 5 (female), 6 (female), 10 (female), and 12 (one male, one female) weeks, using an avidin biotin peroxidase and alkaline phosphatase complex immunohistochemical method on sections of formalin- and ethanol-fixed and frozen tissue specimens. Well-characterized, commercially available antisera/monoclonal antibodies to keratin, vimentin, lysozyme, a monocytic antigen, and a myelomonocytic antigen were used. The immunoreactivity to intermediate-sized filaments in MGC was negative for keratins and positive for vimentin. In addition, a positive reaction was found in alveolar macrophages, chondrocytes, fibrocytes, alveolar lymphocytes, and granulocytes in ethanol-fixed tissue. Marked masking was observed in formalin-fixed tissue. Antilysozyme antiserum gave a positive cytoplasmic reaction in alveolar macrophages and MGC, although the reaction was variable in ethanol-fixed tissue. In trypsinized formalin-fixed tissue, a moderate and more consistent cytoplasmic reaction was observed in alveolar macrophages and MGC. Two monoclonal antibodies that identify human cells of the MMS, EMB 11 and Mac 387, were negative for EMB 11 in ethanol-fixed and frozen sections, whereas Mac 387 showed a positive and specific cytoplasmic immunoreaction in alveolar macrophages and small MGC in ethanol- and formalin-fixed tissue. Pulmonary MGC in dermatosis vegetans are derived from mesenchymal cells, and substantial evidence is provided in support of a monocyte/macrophage origin based on a positive reaction for lysozyme and a myelomonocytic antigen. The importance of adequate fixatives for immunohistochemical demonstration of cell-specific markers is clearly shown.

Topics: Animals; Ethanol; Female; Formaldehyde; Giant Cells; Keratins; Lung; Macrophages, Alveolar; Male; Muramidase; Swine; Swine Diseases; Tissue Fixation; Vimentin

To determine whether the virulence of Streptococcus suis type 2 is associated with the phenotype of the strain, we infected newborn germfree pigs with 10 strains of S. suis type 2 categorized by three phenotypes. In an earlier study, the phenotypes were distinguished by the presence or absence of the muramidase-released protein (MRP) and an extracellular factor (EF) and were designated MRP+ EF+, MRP+ EF- and MRP- EF-. Pigs were first inoculated with Bordetella bronchiseptica to predispose them to infection and were then intranasally inoculated with the streptococci. Strains of the MRP+ EF+ phenotype induced fever and increased the number of polymorphonuclear leukocytes in blood. Specific clinical signs of disease such as nervous disorders and lameness were also observed. At necropsy bacteriologic and pathologic examination disclosed meningoencephalitis, polyserositis, and polyarthritis. Strains of the MRP+ EF- phenotype induced only nonspecific clinical signs of disease such as recumbency, lack of appetite, and fever; only slight pathologic changes were detected in the serosae. The four strains of the MRP- EF- phenotype induced no signs of disease. These findings indicate that the 110-kDa EF and, to a lesser degree, the 136-kDa MRP may be associated with the virulence of the bacterium. The results demonstrated that S. suis type 2 strains producing both MRP and EF are pathogenic for pigs.

Topics: Animals; Animals, Newborn; Bacterial Proteins; Germ-Free Life; Muramidase; Phenotype; Streptococcal Infections; Streptococcus suis; Swine; Swine Diseases; Virulence

Fifteen newborn germ-free pigs were inoculated with 2 strains, D-282 and T-15, of Streptococcus suis type II. Some pigs also were preinoculated with Bordetella bronchiseptica, which successfully predisposed them to S suis infection. The 2 streptococcal strains were differentiated by muramidase treatment, which released certain high molecular-weight proteins, termed muramidase-released proteins (MRP), from the cell wall of strain D-282, but not from the cell wall of strain T-15. Only strain D-282 (MRP-positive) induced clinical signs of disease and markedly increased neutrophil numbers in pigs. Streptococci were more frequently isolated from fecal swab specimens obtained from pigs inoculated with strain D-282 (MRP-positive) than from specimens obtained from pigs inoculated with strain T-15 (MRP-negative). Both strains were isolated from nasal swab specimens obtained from all infected pigs. Postmortem examination revealed fibrinopurulent meningitis, polyserositis, and polyarthritis in pigs inoculated with strain D-282; this strain was isolated from the CNS, serosae, visceral organs, heart, and joints. Whereas strains D-282 caused several pathologic changes, strain T-15, isolated from the lungs, caused only pneumonia. Both strains were isolated from the tonsils of all pigs. Virulence differed distinctly between the MRP-positive and the MRP-negative strains.

Topics: Animals; Animals, Newborn; Bacterial Proteins; Bordetella Infections; Cerebellum; Female; Germ-Free Life; Muramidase; Neutrophils; Species Specificity; Streptococcal Infections; Streptococcus; Swine; Swine Diseases; Virulence

Topics: Animals; Antibodies, Bacterial; Antibody Specificity; Leptospirosis; Muramidase; Swine; Swine Diseases; Time Factors

Topics: Adjuvants, Immunologic; Animals; Animals, Newborn; Antibodies; Bacterial Vaccines; Colostrum; Complement System Proteins; Diarrhea; Escherichia coli; Escherichia coli Infections; Feces; Female; Formaldehyde; Muramidase; Pregnancy; Swine; Swine Diseases; Vaccination