Protective efficacy of a genetic subunit bacterin against edema disease of swine in mice.

The exotoxin SLT-IIeB from the Escherichia coli Ee strain was expressed in E. coli, and the recombinant protein was purified, mixed with the Ee strain, then emulsified with oil-emulsion adjuvants to obtain a mixed subunit bacterin. Groups of Kunming mice were immunized at weeks 0 and 2, and challenged intraperitoneally with the Ee strain at week 4. Antibodies were detected by ELISA and an agglutination test. After the second immunization, the antibody level increased and the rate of immune protection against the Ee strain was 70 and 91.7% in the subunit bacterin and bacterin groups, respectively. Therefore, the mixed subunit bacterin provided good protection against the homologous Ee strain, which provides a basis for further research, into high-efficacy vaccines against porcine edema disease.

The effect of intramuscular administration of colistin on the development and course of experimentally induced oedema disease in weaned piglets.

Shiga-toxigenic E. coli (STEC) strains that produce Shiga toxin Stx2e cause oedema disease in weaned piglets. The purpose of the present study was to investigate the impact of Stx2e released in mesenteric lymph nodes on disease pathogenesis. Colistin and ampicillin were intramuscularly administered to piglets of the experimental group simultaneously challenged with STEC strain, type O139:F18ab, Stx2e+. Piglets of the control group were challenged with STEC only. The strain was naturally resistant to ampicillin and susceptible to colistin. After the challenge, colonisation of the intestines was observed in both antibiotic-treated piglets and control piglets without antibiotic treatment. Histochemistry and scanning electron microscopy revealed sporadic colonisation of the small intestine in the piglets. STEC was detected in the mesenteric lymph nodes of untreated piglets. The clinical manifestations of oedema disease were observed in both groups. In the antibiotic-treated group (11 piglets), oedema disease developed in 10 piglets, eight of which died or were euthanized ante finem. In the untreated group (11 piglets), oedema disease developed in five piglets, four of which died or were euthanized ante finem. We therefore propose that the STEC lysed by colistin suddenly released the toxin from bacterial cells immediately after their passage through the intestinal wall. That could explain a more severe course of oedema disease in the treated piglets. Even though high amounts of STEC were present in the lymph nodes of untreated piglets, the toxin was not released abruptly because the bacterial cells were not damaged.

Effect of antimicrobial agents on the production and release of shiga toxin by enterotoxaemic Escherichia coli isolates from pigs.

Edema disease (ED) of pigs is an enterotoxaemic disease caused by enterotoxaemic Escherichia coli (ETEEC) infection. Antimicrobial therapy for pigs with ED is controversial because it may induce death of sickish piglets. In this study, we investigated the effects in vitro of 7 antimicrobial agents, ampicillin, gentamicin, colistin, bicozamycin, fosfomycin, sulfamethoxazole-trimethoprim and enrofloxacin, on the release and production of shiga toxin (Stx) 2e by ETEEC strains. We found that more Stx 2e accumulated in the bacterial cells than was released into supernatant. Associated with inhibition of cell wall synthesis, the exposure to ampicillin or fosfomycin increased the release of Stx 2e. The production levels of Stx 2e in all antimicrobial-treated cultures were equal to the level in the control or less than in the control. These results suggest that cell wall synthesis inhibitors, such as ampicillin and fosfomycin, may change for the worse in the signs in ETEEC infectious pigs. On the other hand, gentamicin, colistin, bicozamycin and enrofloxacin may be useful for the treatment of pigs with ED.

Antimicrobial susceptibilities of Shiga toxin-producing Escherichia coli isolates from pigs with edema disease in Japan.

Fifty-seven Shiga toxin-producing Escherichia coli (STEC) strains isolated from pigs with edema disease (ED) from 1997 to 2001 in Japan were examined for antimicrobial susceptibilities. The susceptibilities were compared with those of E. coli ATCC 23546 isolated from pig with ED in the 1950's. Consequently, the isolated STECs showed high susceptibility to peptides and bicozamycin in a way similar to the reference strain. On the other hand, the STECs showed low susceptibility to beta-lactams, tetracyclines, novobiocin, fosfomycin, trimethoprim, and old quinolones. It became clear that the susceptibilities of the isolated STECs had diminished in regard to antimicrobials.

Antimicrobial susceptibility of pathogenic Escherichia coli isolated from pigs in Korea.

The in vitro susceptibilities of 285 isolates of Escherichia coli from preweaned and postweaned pigs with diarrhea and edema disease were tested with the 15 commonly used antimicrobial drugs by an agar dilution minimal inhibitory concentration procedure according to National Committee for Clinical Laboratory Standards (NCCLS) guidelines. All E. coli isolates tested in this study belonged to enterotoxigenic E. coli, attaching and effacing E. coli, or Shiga toxin-producing E. coli. Field isolates had low MIC90 for ceftiofur (1 microg/ml). No correlation in antimicrobial resistance was found in three types of E. coli.

An unusual presentation of suspected oedema disease of swine in Kenya.

From a group of 11 recently weaned pigs, 4 were reported to be sick. Clinical examination of the sick pigs revealed marked dyspnoea, bluish-red discolouration of the skin, incoordination and difficulty in walking. Bacteriological examination of the gut contents of 2 pigs that had died earlier yielded pure cultures of haemolytic Escherichia coli. Post mortem examination of the remaining 2 pigs that died subsequently revealed progressive pulmonary collapse. One of these also showed subcutaneous oedema of the head and marked oedema of the mesentery of the spiral colon and oedema of the brain. Microscopically there was pulmonary alveolar collapse and degenerative changes in the liver. On the basis of the clinical signs, isolation of haemolytic E. coli and the post mortem findings, a diagnosis of oedema disease was made.

[Therapy of edema disease/coli complex of weaned piglets--where do we stand today?]. / Therapie der Odemkrankheit/Colikomplex der Absatzferkel--Wo stehen wir heute?

The paper gives an up to date review of our knowledge concerning etiology, clinics and pathogenesis of the edema disease. A therapy protocol is given, an extensive list of original literature for further study is presented.

[The therapeutic effect of central nervous stimulants in edema disease of swine]. / Bericht über die therapeutische Wirkung von zentralnervösen Stimulantien bei der Odemkrankheit der Schweine.

During a natural outbreak of edema disease in different farms 160 weaned piglets showing the clinical symptoms of palpebral edema, mental discomfort and apathy were selected and divided into three groups. The groups were treated as follows: Group 1 (51 piglets) received twice daily one i. m. dose of Gentamycin (11 mg/kg body weight), Prednisolone (1 mg/kg body weight), Melperone (4 mg/kg body weight) for 3 days. Group 2 (55 piglets) received twice daily one i. m. dose of Amphetaminum Phosphoricum 1 mg/kg body weight for 3 days. Group 3 (54 piglets) untreated control. The result showed that group 2 treated with stimulant of the central nervous system gave the best results concerning survival. It ist the authors opinion that concerning clinical symptoms and therapy further classification is necessary.

[Chronic furazolidone poisoning in swine? Practical problems and legal consequences]. / Chronische furazolidon vergiftiging van biggen? Praktijkproblemen en juridische gevolgen.

Long-term treatment (eighteen months) with a medicated feed containing 400 ppm of furazolidone gave rise to side-effects on a pig farm on which the animals were affected with persistent oedema disease. These side-effects disappeared on discontinuation of the medication. In view of this suspected case of chronic furazolidone intoxication the court formulated several questions for a panel of experts. The questions and the replies given are stated.

[Sensitivity of microorganisms isolated from swine to aqueous and proteinic solutions of gentamycin]. / Vurkhu chuvstvitelnostta na niakoi mikroorganizmi, izolirani ot svine, kum voden i beltuchni raztvori na gentamitsin.

Employing a microbiologic method (in vitro) the activity was investigated of Gentamicin DSO Pharmachim, dissolved in water, in normal swine gamma-globulin, and in normal swine polyglobulin with regard to swine strains of Escherichia coli, Salmonella choleraesis Bordetella bronchiseptica, and Pseudomonas aeruginosa as well as Mycoplasms. A strong sensitivity was found to exsist in all tested strains (except for the Mycoplasms) to gentamycin both in a water and in a protein solution. The in vivo testing of the therapeutic effect of the two types of solutions in an experimental infection in albino mice revealed that the differences found in the activity of the various gentamicin solutions were statistically insignificant. The step agglutination test was used to follow up the effect of gentamycin on the OK agglutinating antibodies of a gamma-globulin preparation against oedema disease in pigs. Results showed a slight increase in the agglutinating activity of the gamma-globulin antibodies under the effect of the antibiotic.