Passive protection of calves against experimental infection with Salmonella typhimurium

Cows were vaccinated with formalin-killed Salmonella typhimurium approximately seven weeks and two weeks before parturition to investigate whether passive immunity could protect their calves against experimental S typhimurium infection. After birth the calves were left with their dam for 48 hours and then separated and fed cold, stored colostrum from their own dam for a further eight days. Oral challenge five days after birth with 10(8) S typhimurium did not result in the death of these calves even when they had absorbed little colostrum. Mortality was reduced to 22 per cent in calves which sucked from vaccinated dams and were then fed colostrum from unvaccinated cows and to 50 per cent in calves born to unvaccinated cows and later fed colostrum from vaccinated animals. Calves which sucked from a vaccinated dam and then received stored colostrum from the same cow excreted salmonellas for significantly shorter periods after challenge and were less often infected at necropsy 28 days after inoculation. Protection was not correlated with the levels of O or H agglutinating antibodies in serum, which were at a maximum 24 hours after sucking and then slowly declined. There was no evidence of an active antibody response in the serum. Measurement of the O and H response of cows after vaccination indicated that the vaccination schedule could be improved. The highest levels of agglutinating antibody were measured between two and three weeks after the first vaccination and there was only a minimal response to the second vaccination before parturition.(ABSTRACT TRUNCATED AT 250 WORDS)     

Epidemiology of Salmonella typhimurium infection in calves: excretion of S typhimurium in the faeces of calves in different management systems

Twenty-five batches of market-purchased calves, comprising 589 animals on 11 farms, were examined for the excretion of salmonellas for at least 28 days after their arrival. Salmonellas were found in 217 (51 per cent) of 423 calves from 18 of 21 batches on nine farms. The calves were housed in single pens on eight farms and in groups on the others. The trends in new excreters and the proportion of Salmonella typhimurium excreters were similar in both types of housing, a peak of excretion which was slightly higher in single penned calves, being reached 18 to 19 days after arrival. New excreters were found at most samplings in both types of housing, but the peak of new excreters appeared earlier and declined sooner in single penned calves. On average, single penned animals excreted salmonellas longer. Salmonella dublin was found only in single-penned calves, and the trend in excretion was similar to that for S typhimurium in single-penned calves except that the peak was at about 28 days. Prophylactic feeding of antibiotics was practised on nine farms, but appeared to have no influence on the excretion of salmonellas. Salmonellas were isolated from the environment in six of nine farms studied, even after cleaning and disinfection. It is suggested that the persistence of salmonellas in the environment deserves more attention in the formulation of control programmes.     

Epidemiology of Salmonella typhimurium infection in calves: persistence of salmonellae on calf units.

Salmonella typhimurium DT204C infection is the commonest cause of salmonellosis in calves. On five calf rearing farms a distinct strain, as indicated by plasmid profile analysis, was found to have persisted on the premises for periods ranging from four months to two years, the average being 14 months. The persistence of salmonellae in the environment appears to be an important factor in the epidemiology of calf salmonellosis and clearly indicates the inadequacy of many cleaning and disinfection routines.     

Experimental infection of Red Sokoto goats with Salmonella typhimurium

Salmonella typhimurium infection was experimentally induced in goats by administering 2 x 10(10) organisms per os. The disease produced was characterized by pyrexia, diarrhoea and neutrophilia. One goat died from septicaemia. Somatic "0" agglutinins were detected 14 days post infection (p.i.). Excretion of organisms in faeces ceased by 6 weeks p.i. Goats which recovered from primary infection were refractory to a secondary challenge with 2 x 10(11) organisms. The results indicate that in the absence of signs of ill-health, the detection of neutrophilia and "0" agglutinins and isolation of Salmonella organisms from faeces mainly served as evidence of recent infection.     

Experimental oral Salmonella dublin infection in calves. A bacteriological and pathological study.

Groups of calves (6-7, 12-14 and 24-28 weeks old) were orally infected with different numbers of the virulent Salmonella dublin strain SVA47. For the 6-7 weeks old calves the LD50-dose was estimated to be 1 x 10(7) bacteria. A dose of 10(9) bacteria was lethal within 24 hrs with the calves dying from septicemia and an acute necrotizing panenteritis. Calves 12-14 weeks old given 2 x 10(10) SVA47 bacteria succumbed to a progressive enteritis within one week. The 24-28 weeks old calves were resistant to an infective dose of 1 x 10(10) SVA47 bacteria. In the 6-7 and 12-14 weeks old calves SVA47 could be recovered from the entire intestinal tract, the liver and the spleen. In the oldest calves S. dublin SVA47 was recovered only from fecal specimens. However, the immunohistopathological examinations, using an S. dublin O-antigen-specific mouse monoclonal antibody and PAP-staining, showed the presence of S. dublin SVA47 in all tissues of the intestinal canal from calves of all ages and with a special affinity for the columnar enterocytes of the terminal jejunum and ileum, the follicle-associated epithelium over the Peyer's patches, and glandular tissues in the duodenum, tonsillar area and the lungs. Surviving calves responded with serum antibody titers against the O-antigenic lipopolysaccharide which appeared in the order IgM followed by IgA, IgG1 and IgG2.     

Vaccination of calves against Salmonella dublin with aromatic-dependent Salmonella typhimurium

Ten Holstein calves were divided into 2 groups. Five calves served as nonvaccinated controls, and 5 calves were vaccinated IM at 2 and 3 weeks of age with 10(9) aromatic-dependent (aro-) Salmonella typhimurium strain SL1479 containing O antigens 1, 4, 12. Serious adverse reactions to vaccination were not observed in the calves. Mean maximum rectal temperature increase in the vaccinated calves was 1.5 C. One calf had diarrhea and depressed appetite for 1 day after vaccination. At 5 weeks of age, all calves were challenge exposed orally with 1.5 X 10(11) virulent S dublin strain SL1367 (O antigens 9,12). After challenge-exposure inoculum was given, 1 of 5 vaccinated calves died and 4 of the 5 nonvaccinated calves died (P less than 0.05). Thus, some cross serotype protection against S dublin was induced by parenteral vaccination of calves with aro- S typhimurium strain SL1479, although protection was not complete.     

Immunization of calves with live and inactivated whole-cell vaccines against Salmonella typhimurium infection

Eight calves were immunized with live auxotrophic Salmonella typhimurium mutants (aro -SL 1479, gal E 3821) and twelve calves with phenol-killed whole-cell S. typhimurium vaccine, respectively. The clinical status of the animals was followed and serial reisolation of vaccine and challenge strains from faeces was attempted. The immunization of calves with the live aro- auxotrophic S. typhimurium SL 1479 mutant proved to be unsuitable due to the death of calves after revaccination. The calves immunized with live auxotrophic gal E S. typhimurium CCM 3821 mutant proved to be protected against challenge with virulent S. typhimurium 4/5 strain administered orally at a dose of 10(6) colony forming units (CFU). The postvaccination complications showed serious shortcomings. The immunization of calves with three doses of whole-cell inactivated vaccine containing 5 strains of S. typhimurium was effective against oral challenge with virulent S. typhimurium 4/5 at a dose of 10(6) CFU.     

Prophylactic effects of recombinant bovine interferon-alpha I1 on acute Salmonella typhimurium infection in calves

The in vivo effects of a single prophylactic dose of recombinant bovine interferon (rBoIFN)-alpha I1 in calves with salmonellosis were investigated, using a Salmonella typhimurium infection model. Treatment with rBoIFN-alpha I1 reduced the degree of septicemia compared with that in control groups, and, in one experiment, using disease of reduced severity, body temperature was lower in treated calves than in controls.     

Detection of Salmonella typhimurium infection of chickens.

The serological response of two groups of chickens was followed by three techniques after experimental infection of one group with Salmonella typhimurium. Results obtained illustrate the greater sensitivity of the microantiglobulin (Coombs) test over more conventional methods for detecting salmonella agglutinins. The possibilities of the diagnostic use of the microantiglobulin test in the field are discussed.     

Aromatic-dependent Salmonella typhimurium as modified live vaccines for calves

Strains of Salmonella sp with complete nonreverting aromatic biosynthesis (aro) defects are expected to be nonvirulent, in respect to invasive infection, because they need the aromatic metabolites paraaminobenzoate (for making folate) and dihydroxybenzoate (for making enterochelin) which are not available in host tissues. Derivatives with transposon-generated complete nonreverting aro-defects were prepared from 3 mouse-virulent strains of S typhimurium, namely, FIRN, WRAY, and UCD. The latter 2 parent strains originally were isolated from calves and are known to be calf-virulent. The resultant aromatic-dependent (aro-) strains were used to vaccinate 27 calves (2 to 3 weeks old), usually giving 2 doses by the IM route (10(9) bacteria) or orally (1.5 X 10(11)). Vaccination did not cause severe ill effects in any calf. Thus aro- defects cause loss of virulence for calves, as previously shown for mice. Vaccinated and control calves were challenge exposed, usually at 5 weeks of age, by feeding 1.5 X 10(11) cells of 1 of 2 calf-virulent S typhimurium strains, either UCD 108-11 or SL1323. Of the 16 challenge-exposed control calves, all became anorectic and depressed (CNS), and 15 had diarrhea. Fourteen of the 16 died; all tested tissues were bacteriologically culture-positive for Salmonella at necropsy. Vaccination with the live UCD aro- vaccine strain, SL1479 by either of 2 schedules (IM or orally) appeared effective.(ABSTRACT TRUNCATED AT 250 WORDS)     

Vaccination of calves with a diaminopimelic acid mutant of Salmonella typhimurium.

The purpose of this study was to evaluate the safety and efficacy of a diaminopimelic acid mutant of Salmonella typhimurium as a vaccine for calves. Transposon techniques were used to create a stable nonreverting diaminopimelic acid mutant of a virulent S. typhimurium strain. Calves were vaccinated at weekly intervals with the diaminopimelic acid mutant given as an oral dose of 10(10) organisms, followed by two subcutaneous doses of 10(9) organisms. The calves tolerated vaccination well and the vaccine strain was eliminated from the feces within four days. Of five vaccinated calves, three survived challenge with 5 X 10(9) organisms of the parent strain whereas all five unvaccinated calves that were challenged died. The surviving calves eliminated the challenge organism from the feces within three weeks.     

Galactose epimeraseless mutants of Salmonella typhimurium as live vaccines for calves.

The purpose of the study was to evaluate the safety and efficacy of a galactose epimeraseless mutant of Salmonella typhimurium administered as an oral vaccine to one week old calves and to investigate properties of galactose epimeraseless mutants which affect their virulence and immunogenicity. The galactose epimeraseless mutant S. typhimurium strain G30D caused diarrhea and fever in three calves to which it was administered orally at a dose of 10(10) organisms; all three calves died following challenge with virulent S. typhimurium ten days postvaccination. Mild illness developed in four calves vaccinated with a dose of 9 X 10(6) organisms and one of these calves survived challenge. Three unvaccinated calves died following challenge. The vaccine organism persisted in tissues and was shed for a prolonged period by calves which received 10(10) organisms. Studies of characteristics of galactose epimeraseless mutants of S. typhimurium showed that, in the presence of galactose, there is selection for secondary mutants which are galactose resistant. The studies indicate that galactose epimeraseless mutants of S. typhimurium are not good candidate live vaccine organisms for use in calves.