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Comparison of heterophil phagocytosis for heterophil-adapted Salmonella enteritidis (HASE) and wild-type Salmonella enteritidis (SE).

Serial passage of Salmonella enteritidis (SE) yields heterophil-adapted SE (HASE) strains that have resulted in decreased shedding of SE in feces and reduced egg contamination. Additionally, increasing the number of heterophil passages further reduced the number and frequency of fecal shedding. To evaluate SE and heterophil interaction, nine SE strains were fluorescein isothiocyanate-labeled when viable. There were six wild-types: SE TK 474, SE TK 584, SE TK 599, SE TK 600, SE TK 655, and SE TK 657; and three HASE strains: TK 499 heterophil adapted five times, TK 598 heterophil adapted six times, and TK 605 heterophil adapted 11 times. Trials were repeated seven times in duplicate with heterophils isolated from seven healthy chickens. Heterophils were incubated with the bacterial strains at 41 C for 15 min, and 10,000 heterophils were analyzed by flow cytometry. Percentage of phagocytosis and mean channel number of fluorescence were compared. Both parameters were significantly increased for all HASE-type strains compared with wild-type, nonadapted SE strains. Increased phagocytosis of HASE bacterial strains may be significant in processing and elimination of the HASE strains and may be related to the protective effect of HASE by decreased shedding of wild-type SE challenge strains.

Animals↗

[The selection of Salmonella gallinarum, Salmonella pullorum and Escherichia coli in chickens after chloramphenicol administration].

The effect of a chloramphenicol administration was examined on the selection of E. coli of the chicken intestinal flora, and of the infectious S. gallinarum and S. pullorum strains. On the other hand, an effort was made to detect the frequency of the resistance transmission of E. coli to above mentioned sensitive salmonella strains. Fourteen chicken, 12 infected and 2 negative controls were used. It was found that the enteric E. coli strains became resistant in a week's time. Besides, the strains that were used for infecting the chicken neither were selected through the chloramphenicol administered nor did they take the E. coli resistance, via R-factor transmission.

Animals↗

[The antibiotic sensitivity patterns of Salmonella pullorum and Salmonella gallinarum in in vitro studies].

The antibiotic sensitivity patterns of 100 strains of S. pullorum and 24 strains of S. gallinarum against 19 antibiotics and 3 antibiotic mixtures were determined by the broth dilution method. The strains studied were isolated from enzootic outbreaks of pullorum disease and fowl typhoid. It was found that all the strains were sensitive to ampicillin, streptomycin, neomycin, kanamycin, oxytetracycline, chloromycetin, gentamycin, signamycin, polzomycin, and neotarchocin. Besides, S. pullorum was sensitive to aureomycin. In vitro studies showed that polzomycin and neotarchocin appeared to be the most effective drugs in the treatment of poultry diseases caused by S. pullorum or S. gallinarum. The appearance of high percentage of S. pullorum and S. gallinarum strains resistant simultaneously to several antibiotics points to the necessity of the determination of antibiotic sensitivity patterns of salmonellae isolated from birds.

Animals↗

[Synthesis of moraprenylpyrophosphate derivatives of 3-O-alpha-L-rhamnopyranosyl-(4-O-alpha-D-glucopyranosyl)-alpha-D- galactopyranose and 3-O-alpha-L-rhamnopyranosyl-(4-O-beta-D- glucopyranosyl)-alpha-D-galactopyranose and study of their substrate properties in reactions of the biosynthesis of O-antigenic polysaccharides of Salmonella typhimurium and Salmonella anatum].

Trisaccharides Rha alpha 1----3(Glc alpha 1----4)Gal (I) and Rha alpha 1----3(Glc beta 1----4) Gal (II) have been synthesised. Acetylation of the trisaccharides followed by the McDonald reaction gave rise to alpha-glycosyl phosphates. The latter were converted via coupling with moraprenyl phosphoimidazolidate into polyprenyl pyrophosphate derivatives of (I) and (II), which both serve as substrates for mannosylation and polymerisation reactions with enzymes form the Salmonella anatum and S. typhimurium membranes.

Antigens, Bacterial↗

[Isolation and characteristics of the biological and genetic properties of neamin-resistant mutants of Salmonella typhimurium and Salmonella dublin candidates for vaccine creation].

Mutants, resistant to neamine and spectinomycin, have been isolated from S. typhimurium and S. dublin highly virulent strains. The neamine-resistant mutants can be divided into 3 classes in accordance with their sensitivity to streptomycin: sensitive, resistant to low and high concentrations of this antibiotic. The transduction analysis with the use of bacteriophage P 22 has revealed that the spectinomycin-resistant mutations under study are spc A mutations, while the mutations leading to resistance to neamine in class Near Strr 500 are nea B mutations. The mutation leading to resistance to spectinomycin (spc A) has been found to produce no changes in the virulence of salmonellae in the intraperitoneal infection of mice. The mutations leading to resistance to neamine and streptomycin (nea B and str A) have been found to decrease virulence.

Animals↗

[Interrelation of the sensitivity of Salmonella derby cells to phage dp8 with the R plasmid of Salmonella derby].

In the process of studying phage--Salmonella derby plasmid interaction effect, it has been found that the absence of the plasmid blocks the adsorption step and the step of phage penetration into the cell. However, the lytic functions and those responsible in maintenance of the lysogenic state are independent of plasmid. Probably, resistance of plasmidless cells of S. derby to extracellular dp8 phage is mediated by the absence of plasmid-borne genes in S. derby coding for membrane peptides which are indispensible for adsorption and DNA penetration into the cell.

Adsorption↗

Immunochemistry of Salmonella O-antigens: preparation of an octasaccharide-bovine serum albumin immunogen representative of Salmonella serogroup B O-antigen and characterization of the antibody response.

The O-antigenic polysaccharide of phenol-water extracted Salmonella typhimurium (O antigens 4, 12) lipopolysaccharide was enzymatically cleaved by phage P22 endorhamnosidase. An octasaccharide with the (formula: see text) structure Gal-Man-Rha-Gal-Man-Rha was isolated and shown to retain the O-antigen 4 specificity of the native polysaccharide. After oxidation of the terminal reducing rhamnose residue to the corresponding aldonic acid, the octasaccharide was covalently linked to bovine serum albumin (OLS-BSA) by use of a water-soluble carbodimide. The resulting conjugate showed O-antigen 4 specificity in enzyme-linked immunosorbent assay (ELISA) ans passive hemagglutination inhibition tests. Immunization of rabbits with the OLS-BSA conjugate gave rise to antibodies directed toward both the octasaccharide and the carrier protein. ELISA titration with synthetic disaccharide-protein conjugates as antigens revealed that the antibody titer against the mannose-rhamnose structure was higher than against the abequose-mannose structure. In rabbits immunized with heat-killed whole bacteria the titers against the two disaccharides were equal. The reason for this difference is not obvious. It is evident, however, that the OLS-BSA conjugate elicited in rabbits O-antibodies with the same specificity as whole bacteria.

Animals↗

Epidemiology of Salmonella infection in calves: the source of calfhood infection by Salmonella dublin.

Investigation of the source of neonatal Salmonella dublin infection of calves was undertaken by carrying out caesarean section of cows with a history of excretion of S dublin following either S dublin enteritis or S dublin abortion. No evidence of transplacental infection was detected but six of 10 animals showed evidence of excretion of the organism in the faeces, vaginal discharge or milk in the period immediately following parturition. The strong probability of early infection as a result of contamination of the environment is therefore suggested.

Animals↗

Salmonella gallinarum - Salmonella enteritidis relationship in rabbits.

The polysaccharide of S. gallinarum, sharing factors 9.12 with the Salmonellae of group D. cross-reacts with one of two serological determinants, present in the polysaccharide of S. enteritidis, and is different from the determinant responsible for the cross-reaction of S. enteritidis and S. typhy polysaccharides. The absorption of anti S. gallinarum sera with proteins from S. enteritidis removed all the antibodies induced for the homologous antigens; in contrast, the absorption of the anti S. enteritidis sera with proteins from S. gallinarum removed all the antigens common to S. gallinarum and S. enteritidis, leaving for reaction the antibodies induced to specific antigens of S. enteritidis.

Animals↗

Comparison of prophylactic and therapeutic efficacy of Salmonella enteritidis-immune lymphokines against Salmonella enteritidis organ invasion in neonatal Leghorn chicks.

Investigations in our laboratories have indicated that when Salmonella enteritidis (SE)-immune lymphokines--supernatants from concanavalin-A-stimulated T cells derived from SE-immune adult chickens--were administered intraperitoneally to 1-day-old chicks before SE challenge, they conferred protection against SE organ invasion within 24 hr. This resistance mediated by SE-immune lymphokines was associated with a concomitant increase in peripheral blood polymorphonuclear leukocytes that peaked 4 hr after SE challenge. In the present study, we evaluated efficacy of SE-immune lymphokines in protecting chicks against SE organ invasion and alterations in peripheral blood polymorphonuclear leukocyte counts. Administration of SE-immune lymphokines to chicks either 30 min or 6 days before SE challenge caused a significant reduction in SE organ invasion. However, when SE-immune lymphokines were administered 2 days after SE challenge, there was no reduction in SE organ invasion. Both prophylactic (before SE challenge) and therapeutic (after SE challenge) administration of SE-immune lymphokines caused a significant increase in numbers of peripheral blood polymorphonuclear leukocytes. Results from these studies suggest that SE-immune lymphokines have potential value as an effective prophylactic but not as a therapeutic modulator of early resistance to SE organ invasion in neonatal leghorn chicks.

Animals↗

Culture of Salmonella typhi and Salmonella paratyphi from blood and bone marrow in suspected typhoid fever.

We studied the yield of blood and bone marrow (BM) cultures in 145 patients clinically suspected of typhoid fever (TF) in Indonesia. The objectives were to compare the positivity of blood culture using 3 ml versus 10 ml of blood and to examine in how far specific antibiotic treatment for TF interfered with the positivity of BM culture. Blood for culture was collected before antibiotic treatment was initiated in hospital and BM 1 to 10 days after the start of treatment. Cultures were performed with Oxgall subcultured on SS agar. Seventy-nine per cent of patients was treated for 14 days or more with oral chloramphenicol, 18% with chloramphenicol followed by ampicillin or cotrimoxazol and 3% with other antibiotics. Cultures were positive for Salmonella typhi or S-paratyphi A in 57 of the 145 patients (39.3%) when 3 ml of blood was cultured and in 58 (40%) when 10 ml of blood was cultured. BM culture was positive despite antibiotic treatment in 70 patients (48.2%); this positivity was significantly greater than that of blood cultures (p < 0.05). When we considered the positivity of BM culture in relation to the number of days on antibiotics in hospital, the yield of BM culture remained apparently unchanged during the first 5 days of treatment. This may be the consequence of slow elimination of S.typhi or S.paratyphi by the antibiotics used and could be responsible for relapses.

Adolescent↗

Salmonella typhi and Salmonella paratyphi antibodies in Kenya.

The distribution of Salmonella typhi, S. paratyphi A. and S. paratyphi C. agglutinins among 364 sera from a randomly selected group of healthy individuals in Nairobi and Naivasha (Kenya) were analysed in relation to bacteriologically confirmed cases of typhoid fever at the Kenyatta National Hospital (KNH). Out of these, 30% of the healthy individuals had no detectable Widal titres. Overall agglutinin titres obtained for the healthy population showed that 96% of the individuals had low level reactivity with titres < 1:80 for both H and O antigens of S. typhi, while 4% had titres of 1:160 or above. Agglutinins for S. paratyphi A and C were rarely present in the sera tested. Age and sex were found to have no effect on antibody titre distribution in the two populations but differences in the water source may have affected the percentage of positive tests recorded. In this typhoid endemic region titres upto 1:80 are not uncommon but both H and O titres of 1:160 and above found in conjunction with the clinical picture may be taken to be suggestive of typhoid fever.

Adolescent↗

Application of phage lambda technology to Salmonella typhimurium. Construction of a lambda-sensitive Salmonella strain.

We have previously constructed a novel strain of S. typhimurium carrying the E. coli lamB gene and shown that this strain adsorbs phage lambda and, for example, can be used for transposon mutagenesis with lambda vectors. In this study, we show that this strain can support the lytic growth of phage lambda nin derivatives, but not growth of wild-type lambda. However, lysogenization with lambda nin does not occur. Using this strain as starting material we took the construction one step further by introducing the E. coli nusA gene in a multicopy plasmid to this strain. We could show that this new Salmonella derivative can support both the lytic and lysogenic mode of growth of several different lambda derivatives. Using the same approach it should be possible to construct lambda-sensitive derivatives of other enteric bacteria thus rendering them more amenable to in vivo genetic manipulation.

Bacteriophage lambda↗

Effects of high levels of selenite and Escherichia coli on enrichment of Salmonella and detection of Salmonella by polymyxin-cloth enzyme immunoassay.

The effect of various concentrations of selenite on the recovery of Salmonella typhimurium and Escherichia coli was examined in a rich medium containing 0.5% cholate. For heat-injured S. typhimurium, longer preincubation periods were required for recovery in higher concentrations of selenite. When 0.7% selenite was added to 6-h preincubated cultures of heat-injured cells, S. typhimurium was fully recovered while E. coli, whether heat-injured or uninjured, did not recover when present at numbers at less than 2 x 10(7) colony forming units (CFU). The polymyxin-cloth enzyme immunoassay detected S. typhimurium grown from a small number (as low as 1 CFU) of cells in the presence of a large excess of E. coli.

Cholic Acid↗

Vaccination of chickens with chicken-derived Salmonella enteritidis phage type 4 aroA live oral Salmonella vaccines.

Two strains of Salmonella enteritidis phage type 4 isolated from chickens, SeLA5 and Se267, were virulent in Balb/c mice by intraperitoneal (i.p.) infection. In 18-20-day-old chickens given 10(7) c.f.u. intravenously (i.v.), both strains caused some deaths. One-day-old chicks infected orally with 10(9) c.f.u. of either strain also suffered limited mortality. Strain SeLA5 was the more virulent by the oral route. AroA mutants SeLA5 aroA and Se267 aroA were reduced in i.p. virulence by up to six logs in the Balb/c mouse model, did not kill 18-20-day-old chickens when injected i.v. and did not multiply in the tissues. Oral vaccination of chicks with either 10(9) c.f.u. at one-day-old or 10(5) c.f.u. at seven-day intervals until day 21 with vaccine strains SeLA5 aroA or Se267 aroA conferred significant protection against intravenous challenge with virulent strain Se109 NalR and reduced intestinal shedding following oral challenge. Seroconversion following oral vaccination was not seen with the lower dose regimen and was low with the higher dose. Seroconversion following oral challenge was marked in unvaccinated birds but much lower in vaccinated birds, suggesting that oral vaccination had prevented invasion by the challenge strain.

Administration, Oral↗