Proliferative enteropathy caused by Lawsonia intracellularis is one of the most common enteric diseases in pigs. The objective of this study was to determine the prevalence of serum antibodies against L. intracellularis in the general swine population of Korea from 2005 to 2008. In total, 8,008 swine serum samples obtained from 1,001 herds were tested. The samples were analyzed with an immunoperoxidase monolayer assay to detect anti-L. intracellularis antibodies. The overall 4-year average true prevalence was 40.0% (CI: 39.4 - 40.6%) at the individual animal level and 71.9% (CI: 70.3-73.4%) at the herd level.
Animals ; Antibodies ; Korea ; Lawsonia Bacteria ; Marketing* ; Prevalence ; Seroepidemiologic Studies* ; Swine

PURPOSE: Porcine proliferative enteropathy (PPE) is known as one of the most important risk factors causing economic losses in swine industry worldwide. This study was conducted to evaluate the efficacy of a commercial oral attenuated Lawsonia intracellularis vaccine (Enterisol Ileitis) against PPE under a commercial pig farm condition in Korea. MATERIALS AND METHODS: Thirty two-day-old 672 piglets were randomly allocated into vaccinated and control groups. All piglets in the vaccinated group were inoculated with a commercial attenuated L. intracellularis vaccine as following the manufacturer's instruction. Body weights of all pigs in both groups were measured on the vaccination day and 6, 14, and 20 weeks post vaccination and an average daily weight gain (ADWG) was calculated. Health status was observed biweekly during the whole trial. RESULTS: The vaccinated group showed significantly higher body weight (p<0.05) and ADWG (p<0.05) than those of the control group. The vaccinated group had significantly reduced impairments in activity, growth, defecation frequency, and stool hardness (p<0.05). Additional health benefits and improved weight gain by the vaccination produced a 4.2:1 return of investment, and the higher gross margin was $4.80 per pig. CONCLUSION: Our finding suggests that the L. intracellularis vaccine program has effects on the substantial health and economic benefits in the Korean swine industry.
Body Weight ; Defecation ; Hardness ; Ileitis ; Insurance Benefits ; Intestinal Diseases ; Investments ; Korea ; Lawsonia Bacteria ; Risk Factors ; Swine ; Vaccination ; Vaccines ; Weight Gain

Porcine proliferative enteropathy (PPE) caused by Lawsonia intracellularis (LI) is a global cause for substantial economic losses in the swine industry. Here, we constructed live attenuated Salmonella typhimurium (ST) mutant strains expressing and secreting 4 selected immunogenic LI antigens, namely, optA, optB, Lawsonia flagellin (LfliC), and Lawsonia hemolysin (Lhly); the resultant recombinant strains were designated Sal-optA, Sal-optB, Sal-LfliC, or Sal-Lhly, respectively. Using the BALB/c mouse model, we demonstrate that mice vaccinated once orally, either with a mixture of all 4 recombinant strains or with an individual recombinant strain, show significant (p < 0.05) production of LI-specific systemic immunoglobulin (Ig) G and mucosal IgA responses compared to the Salmonella alone group. Upon restimulation of vaccinated splenocytes with the LI-specific antigens, significant (p < 0.05) and comparable production of interferon-γ responses are found in all vaccinated groups, except the Sal-Lhly group, which shows non-significant levels. Challenge studies were performed in C57BL/6 vaccinated mice. On challenge with the LI (10(6.9) 50% tissue culture infectious dose) 14 days post-vaccination, 20% (1/5) of mice in all vaccinated groups, except Sal-Lhly group, show the presence of the LI-specific genomic DNA (gDNA) in stool samples. In contrast, 40% (2/5) and 60% (3/5) of mice vaccinated with the Sal-Lhly strain and the attenuated Salmonella alone, respectively, were found positive for the LI-specific gDNA. Furthermore, 0% mortality was observed in mice vaccinated against the ST challenge compared to the 30% mortality observed in the unvaccinated control group. In conclusion, we demonstrate that the Salmonella-based LI-vaccines induce LI-specific humoral and cell-mediated immunities, and encompass the potential to offer dual protection against PPE and salmonellosis.
Animals ; DNA ; Flagellin ; Immunity, Cellular ; Immunoglobulin A ; Immunoglobulins ; Lawsonia Bacteria ; Mice ; Mortality ; Salmonella Infections ; Salmonella typhimurium ; Salmonella ; Swine

Lawsonia intracellularis is not culturable with a standard bacteriologic culture. One step PCR assay as a clinical diagnostic method was developed for the rapid detection of porcine proliferative enteritis (PPE) caused by L. intracellularis. Primers were designed based on the p78 DNA clone of L. intracellularis. The one step PCR resulted in the formation of a specific 210-bp DNA product derived from L. intracellularis. The nonspecific amplification product was not detected with swine genomic DNA or other bacterial strains causing similar symptoms to L. intracellularis infection. The one step PCR was as sensitive as 100 pg of L. intracellularis genomic DNA. We applied this method to field specimens diagnosed as PPE by macroscopic observation. Of 17 mucosal scraping specimens, 16(94%) were identified as positive to PPE and 15(88%) of 17 feces specimens. These results suggest that the one step PCR can be used as a rapid diagnostic method for L. intracellularis infection.
Animals ; Base Sequence ; DNA Primers ; Desulfovibrionaceae Infections/diagnosis/*veterinary ; Ileum/microbiology/pathology ; Intestinal Mucosa/microbiology/pathology ; Lawsonia Bacteria/genetics/*isolation & purification ; Polymerase Chain Reaction/*methods ; Reproducibility of Results ; Sensitivity and Specificity ; Swine ; Swine Diseases/*diagnosis/microbiology

Proliferative enteropathy was reproduced in IFN-gamma receptor knockout (IFN-gamma R-) mice by experimental infection with Lawsonia intracellularis (L. intracellularis). The cecum and the colon of the infected mice were evidently enlarged 2 weeks post infection. The presence of L. intracellularis was identified in the stool and the cecum of the mice after infection. However, high levels of IFN-gamma were detected in the sera of the infected mice 2 weeks PI. These data indicated that the IFN-gamma produced in the infected mice should have been utilized by it's receptor to elicit protective immune responses against L. intracellularis infections.
Animals ; DNA, Viral ; Desulfovibrionaceae Infections/*immunology/microbiology ; Interferon Type II/*immunology ; Intestinal Diseases/*immunology/microbiology ; Intestinal Mucosa/immunology ; Lawsonia Bacteria/*immunology/isolation&purification ; Mice ; Mice, Knockout ; Polymerase Chain Reaction ; Receptors, Interferon/physiology

A multiplex PCR assay was developed for the simultaneous detection of the etiologic agents associated with porcine proliferative enteropathies (PPE), swine dysentery (SD)and porcine salmonellosis (PS)in a single reaction using DNA from swine intestinal samples. Single and multiplex PCR amplification of DNA from Lawsonia intracellularis, Salmonella typhimurium and Brachyspira hyodysenteriae with each primer set produced fragments of the predicted size without any nonspecific amplification, 210-bp, 298-bp and 403-bp bands, respectively. The single PCR assay could detect as little as 100 pg of purified DNA of S. typhimurium and L. intracellularis, and 50 pg of B.hyodysenteriae, respectively. However, multiplex PCR turned out to be 10 times lower sensitivity with S. typhimurium compared with single PCR. With 23 swine intestinal specimens suspected of having PPE, SD and/or PS, the multiplex PCR assay showed identical results with conventional methods except one. In conclusion, this multiplex PCR is a feasible alternative to standard diagnostic methods for detection of L. intracellularis, B. hyodysenteriae and Salmonella spp. from swine intestinal specimens.
Animals ; Desulfovibrionaceae Infections/microbiology/veterinary ; Intestines/microbiology ; Lawsonia Bacteria/*isolation&purification ; Polymerase Chain Reaction/*methods/veterinary ; Salmonella/*isolation&purification ; Salmonella Infections, Animal/diagnosis ; Sensitivity and Specificity ; Spirochaetales/*isolation&purification ; Spirochaetales Infections/microbiology/veterinary ; Swine ; Swine Diseases/*diagnosis/*microbiology

OBJECTIVETo reveal the antibacterial activity of sequentially extracted different cold organic solvent extracts of fruits, flowers and leaves of Lawsonia inermis (L. against) some pathogenic bacteria.

METHODSPowders of fruits, flowers and leaves of L. inermis were continuously extracted with dichloromethane (DCM), ethyl acetate and ethanol at ambient temperature. The dried extracts were prepared into different concentrations and tested for antibacterial activity by agar well diffusion method, and also the extracts were tested to determine the available phytochemicals.

RESULTSExcept DCM extract of flower all other test extracts revealed inhibitory effect on all tested bacteria and their inhibitory effect differed significantly (P<0.05). The highest inhibitory effect was showed by ethyl acetate extract of flower against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), and ethyl acetate extract of fruit on Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis). The ethyl acetate and ethanol extracts of flower, fruit and leaf expressed inhibition even at 1 mg/100 µl against all test bacteria. Among the tested phytochemicals flavonoids were detected in all test extracts except DCM extract of flower.

CONCLUSIONSThe study demonstrated that the ethyl acetate and ethanol extracts of fruit and flower of L. inermis are potentially better source of antibacterial agents compared to leaf extracts of respective solvents.

Anti-Bacterial Agents ; chemistry ; pharmacology ; Bacteria ; drug effects ; Disk Diffusion Antimicrobial Tests ; Flowers ; chemistry ; Fruit ; chemistry ; Lawsonia Plant ; chemistry ; Phytochemicals ; chemistry ; Plant Components, Aerial ; chemistry ; Plant Extracts ; chemistry ; pharmacology ; Plant Leaves ; chemistry ; Solvents ; Sri Lanka

The prevalence of Lawsonia intracellularis, Brachyspira hyodysenteriae and Salmonella spp. were investigated by multiplex PCR using fecal samples of pigs with diarrhea or a history of diarrhea. The overall herd prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. were 46.5%, 37.2% and 51.1%, respectively. Also, the prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. among all sampled pigs were 19.9%, 10.8% and 17.7%, respectively. Seventeen of 43 herds were positive with 2 enteric organisms, and 2 herds were positive with L. intracellularis, B. hyodysenteriae and Salmonella spp. simultaneously. It was notable that 11 of 12 herds with more than 2, 000 pigs were affected with Salmonella spp., and that only 2 of 12 the herds were affected with B. hyodysenteriae. This study suggested that herds positive for L. intracellularis, B. hyodysenteriae and Salmonella spp. were distributed throughout Korea, although the relationship among other pathogens such as viral or parasitic ones and/or with metabolic disorders was not determined.
Animals ; DNA, Bacterial/isolation&purification ; Desulfovibrionaceae Infections/epidemiology/microbiology/*veterinary ; Diarrhea/microbiology/veterinary ; Korea/epidemiology ; *Lawsonia Bacteria/isolation&purification ; Polymerase Chain Reaction/veterinary ; Prevalence ; *Salmonella/isolation&purification ; Salmonella Infections, Animal/*epidemiology/microbiology ; *Serpulina hyodysenteriae/isolation&purification ; Spirochaetales Infections/epidemiology/microbiology/*veterinary ; Swine ; Swine Diseases/*epidemiology/microbiology

Porcine proliferative enteropathy(PPE) is an enteric disease been caused by Lawsonia intracellularis. It has become one of the critical problems in the pig industry. To investigate the prevalence of PPE in Korea, serum samples of 828 pigs from 65 herds were tested using indirect immunofluorescence antibody technique(IFA). The infection rate in individual pigs varied from 44 to 69%, whereas 100% in pig farms. The infection frequency was 57, 44.9, and 59.4% according to age respectively. Administration of tylosin in feed at a concentration of 110 ppm for 14 days reduced the infection rate of the farms. These data indicated that the high prevalence of PPE may be controlled by tylosin.
Administration, Oral ; Animal Feed ; Animals ; Anti-Bacterial Agents/*therapeutic use ; Antibodies, Bacterial/blood ; Enteritis/epidemiology/prevention&control/*veterinary ; Fluorescent Antibody Technique, Indirect/veterinary ; Gram-Negative Bacterial Infections/prevention&control/*veterinary ; Korea/epidemiology ; *Lawsonia Bacteria/drug effects/growth&development/immunology ; Seroepidemiologic Studies ; Swine ; Swine Diseases/*epidemiology/microbiology/prevention&control ; Tylosin/*therapeutic use