Biomedical subjects

T K Mukkur

Publications and source records attributed to T K Mukkur.

At least 19 recordsLinked to original sources

PubMed2000

Rapid-cycle PCR method to detect Bordetella pertussis that fulfills all consensus recommendations for use of PCR in diagnosis of pertussis.

No standardized PCR method is available for the laboratory diagnosis of the pertussis syndrome. Consensus recommendations for the use of PCR in the diagnosis of Bordetella pertussis infections have been proposed, and the aim of this study was to develop a method that fulfills all of these criteria. A rapid-cycle shared-primer PCR method with a microwell format and probe hybridization detection step (POR) was developed using novel oligonucleotides targeted to the outer membrane porin gene (Bordetella spp.). In specimens positive for Bordetella spp., B. pertussis was differentiated from Bordetella parapertussis and Bordetella bronchiseptica by hybridization with organism-specific oligonucleotide probes. An internal control was developed using overlap extension PCR and mouse beta-actin DNA. The analytical specificity was 100%. The analytical sensitivity was comparable to that of nested IS481 and IS1001 PCR ( approximately 1 organism per reaction). The clinical sensitivity and specificity were ascertained using 705 specimens (from 705 patients). The results were compared to those of a nested-PCR method targeting the insertion sequences IS481 and IS1001. Fifty-one specimens were positive for B. pertussis by POR and IS481 PCR. Two specimens which fulfilled a clinical definition of pertussis were positive by POR and negative by IS481 PCR. A total of 652 specimens were negative by both methods. B. parapertussis was not detected in any specimens. PCR inhibition was detected in 21 out of 705 specimens (2.98%). Thus, a rapid (4 h, including specimen preparation) PCR method which fulfills all of the consensus recommendations was developed and validated for the detection of B. pertussis.

Animals↗

PubMed1999

Nested duplex PCR to detect Bordetella pertussis and Bordetella parapertussis and its application in diagnosis of pertussis in nonmetropolitan Southeast Queensland, Australia.

A duplex PCR to detect Bordetella pertussis and Bordetella parapertussis was developed with the insertion sequences IS481 (B. pertussis) and IS1001 (B. parapertussis) and evaluated with specimens from 520 consecutive patients presenting with possible pertussis. No culture-positive-PCR-negative results occurred, giving the method a sensitivity of 100%. For B. pertussis, 58 of 520 patients (11.2%) were positive by PCR compared to 17 of 520 patients positive (3.3%) by culture. For B. parapertussis, 7 of 520 patients (1.3%) were positive by PCR compared to 2 of 520 patients positive (0.4%) by culture. Two patients were positive for both B. pertussis and B. parapertussis. Patient records were reviewed to determine the validity of PCR-positive-culture-negative results. Forty-two of 49 patients who could be evaluated fulfilled the criteria for a case definition of pertussis, with 32 patients being <1 year of age and having classical pertussis symptoms. The seven patients who did not fulfil the criteria were aged 7 to 55 years and had a persistent cough for >2 weeks. The method was also used to investigate a classroom outbreak in which B. pertussis culture was positive for 5 of 28 patients. All five culture-positive specimens were confirmed by PCR, and an additional eight were positive by PCR. Of 25 patients from a suspected pertussis outbreak in a girls' dormitory, seven of seven specimens were negative for B. pertussis, although 13 of 25 patients were positive for B. pertussis immunoglobulin M (IgM) (2 of which produced equivocal IgA results, with 23 of 25 patients being negative). Five symptomatic patients were subsequently found to be positive (by IgM and particle agglutination assays) for Mycoplasma pneumoniae, demonstrating the value of PCR in rapidly excluding B. pertussis infection in an outbreak situation. Twenty-two of 71 (30. 1%) throat swabs were positive by PCR compared to 2 of 71 (2.8%) throat swabs positive by culture, indicating that a reassessment of the use of throat swabs should be considered, particularly for older patients, in contact tracing, and in situations in which specimen collection is difficult.

Antibodies, Bacterial↗

PubMed1998

Passive immunisation of neonatal lambs via colostrum and milk of ewes previously immunised with live attenuated Salmonella typhimurium protects neonatal lambs from experimental salmonellosis.

Lambs sucking non-immunised ewes or ewes immunised 4-5 weeks before lambing with live attenuated, aromatic-dependent (aroA) Salmonella typhimurium (strain CS 332) were challenged orally at either 2, 4 or 7 days of age with virulent S. typhimurium (strain CS 94) at doses ranging from 10(9) to 10(13) colony forming units. No lambs displayed signs of clinical salmonellosis and all survived challenge but those sucking immunised ewes had organisms of the challenge strain in their faeces for much shorter periods of time than lambs of the control ewes. High titres of specific antibodies were measured in colostrum and milk of immunised ewes in comparison with very low titres measured in samples from control ewes; these differences were reflected by the titres of antibodies in the sera of corresponding lambs. At 2 days after lambing, the major antibody isotype in the colostrum of immunised ewes and sera of their lambs was IgM whereas at 7 days IgG1 was the predominant isotype. While it was clear that vaccination of pregnant ewes with the live attenuated vaccination conferred protection against experimentally-induced salmonellosis in their lambs, considerable protection was observed in control lambs in spite of there being very low titres of antibodies in the mammary secretion of their dams. The latter observation could be related to the presence of contain non-antibody potent bactericidal factors previously described in colostrum and milk.

Aging↗

PubMed1998

Immunogenicity of purified lipopolysaccharide or protein-oligosaccharide conjugates of Pasteurella multocida type 6:B in mice.

Purified lipopolysaccharide (LPS) of Pasteurella multocida type 6:B, while toxic at higher doses, was protective at lower dose levels against experimentally-induced pasteurellosis in mice. However, the observed protection was abrogated if such LPS was digested with proteinase K prior to use in immunisation. The O-antigen polysaccharide side-chain (OS) of LPS did not appear to contribute to the observed protection as judged by the fact that immunisation of mice with purified OS or OS-protein conjugates, all of which were nontoxic, failed to confer protection against challenge with homologous virulent organisms. This was despite generation of significant levels of OS-specific antibodies, predominantly either of the IgM or IgG isotypes, in immunised mice.

Adipates↗

PubMed1995

Systemic and mucosal intestinal antibody response of sheep immunized with aromatic-dependent live or killed Salmonella typhimurium.

Following the development of a suitable formulation capable of inhibiting intestinal proteolytic activity, the total anti-lipopolysaccharide (LPS) and anti-flagellin (Fla) antibody response and isotype in the sera and intestinal washings of sheep, immunized with live aromatic-dependent (aro-) Salmonella typhimurium strain CS332 by the intramuscular (live i.m.) or oral (live oral) route or acetone-killed virulent S. typhimurium by the intramuscular route (killed i.m.), were determined at various intervals post-immunization. The serum or intestinal anti-lipopolysaccharide (LPS) or anti-flagellin (Fla) antibody titres of immunized sheep, regardless of the route of immunization, were significantly greater (P < 0.01) than those of non-immune control sheep. Although significant differences between the serum anti-LPS or anti-Fla antibody titres of sheep in various immunization regimes were observed, they were not consistent for different periods post-immunization. The predominant isotype contributing to serum anti-LPS antibody activity was IgM whereas the serum antiflagellar antibody activity was confined to IgM, IgG1 and IgG2. In either case, the contribution of the IgA antibody isotype was minimal. Antibody activity in the intestinal washings of immunized sheep, regardless of the route of immunization was significantly greater (P < 0.01) than that in non-immune control sheep. However, the titres in sheep immunized with the live S. typhimurium vaccines were significantly greater than those immunized with the killed vaccine. The major anti-LPS or anti-flagellin antibody isotype in the intestinal washings of sheep in the live i.m. or live oral groups was IgM at day 7 post-immunization followed by IgG1 and IgG2 at days 14 and 21 post-immunization, with only a minimal contribution by the IgA antibody isotype. On the other hand, the major antibody isotype in the intestinal washings of sheep immunized with the killed S. typhimurium was IgG1.

Administration, Oral↗

PubMed1994

Relationship between active protection in vaccinated buffaloes against haemorrhagic septicaemia and passive mouse protection test or serum antibody titres.

The relationship between the standard passive mouse protection test or serum antibody titres measured by indirect haemagglutination or enzyme-linked immunosorbent assays and active protection in buffaloes immunized with different types of haemorrhagic septicaemia bacterins was investigated. Groups of 2-3 buffaloes were immunized with the bacterins currently in use in Asia, viz., broth bacterin (BB), alum precipitated vaccine (APV) and oil adjuvant vaccine (OAV) either subcutaneously (BB, APV) or intramuscularly (OAV) and challenged subcutaneously with virulent organisms at different periods post-immunization. Although the passive mouse protection and indirect haemagglutination tests carried out with the pre-challenge sera from vaccinated buffaloes revealed no relationship with active protection in buffaloes, a relationship was observed between the ELISA antibody titres and protection. In contrast, a dose-response relationship was observed between the homologous active and passive mouse protection test.

Animals↗

PubMed1994

Characterization of immune response and duration of protection in buffaloes immunized with haemorrhagic septicaemia vaccines.

Two of the three buffaloes immunized with a non-adjuvanted broth bacterin were found to be protected against experimental challenge at 6 weeks but not at 3 months post-challenge. Similarly all buffaloes (4/4) immunized with alum-precipitated vaccine were protected at 6 months but only 1 of the 2 vaccinated animals were protected at 12 months post-immunization. On the other hand, buffaloes immunized with an oil adjuvant and a double emulsion vaccine were completely protected at 12 months post-immunization. Statistically significant differences between immunized versus non-immune animals became evident at 3 months post-immunization, although analysis of cumulative antibody titres of pre-challenge sera of vaccinated buffaloes surviving versus those succumbing to experimental challenge revealed significant by higher antibody titres in the former as compared to the latter group. These results suggested that there was a relationship between ELISA antibody titres and active protection in buffaloes. There also appeared to be a relationship between cutaneous delayed-type hypersensitivity and active protection in buffaloes. Preliminary analysis of the antibody isotype distribution in the pre-challenge sera of 2 buffaloes vaccinated with the oil adjuvant vaccine revealed predominance of IgG1 and IgG2 subclasses whose role in protection against haemorrhagic septicaemia was not eludicated.

Animals↗

PubMed1992

Development and duration of protection against salmonellosis in mice and sheep immunised with live aromatic-dependent Salmonella typhimurium.

The aim of this investigation was to determine the development and duration of protection in mice or sheep immunised with aromatic-dependent (aro-) Salmonella typhimurium strain CS332, by either parenteral or oral routes. Immunisation of mice by the intraperitoneal or sheep by the intramuscular routes was found to impart protection against oral challenge with the virulent parent S typhimurium strain CS94 as early as seven days after immunisation. In contrast, when immunisation was carried out by the oral route, protection was not evident until three weeks after immunisation. Regardless of the route of immunisation, mice were still partially protected at three months and were fully susceptible at six months after immunisation. In sheep, protection persisted for six months but not 12 months after immunisation. Only parenterally immunised mice and sheep developed high ELISA and, or, agglutinating antibody titres, and cutaneous delayed-type hypersensitivity (DTH) at three weeks after immunisation. Although both antibody and DTH were detectable three months after immunisation of mice with aro- S typhimurium strain CS332, none was detected at six months. Antibody measured by agglutination and ELISA was detectable six months after immunisation in sheep, although no DTH was evident. At 12 months after immunisation low levels of anti-LPS antibody (measurable by ELISA only) were detected in sheep immunised by the intramuscular route.

Administration, Oral↗

PubMed1991

Immunizing efficacy of aromatic-dependent Salmonella dublin in mice and calves.

Mice immunized with an aromatic-dependent (aro-) S. dublin strain CS101 by either the intraperitoneal (i.p.) or oral route, were protected against oral challenge with a virulent S. dublin strain CS90, the degree of protection being the greatest when mice had received 3 immunizing doses at weekly intervals. Mice immunized with an aromatic-dependent (aro-) S. typhimurium strain CS332 by the i.p. or oral routes were protected against challenge with virulent S. dublin strain CS90 at 1 or 2 weeks but not at 3 or 4 weeks post-immunization. Mice immunized with 1 dose of aro- S. dublin strain CS101 by the i.p. route developed low levels of lipopolysaccharide (LPS) and flagellin-specific antibody but no delayed-type hypersensitivity (DTH) whereas those immunized with 2 or 3 doses developed significantly higher antibody titres and DTH. In contrast, mice immunized by the oral route developed neither significant antibody response nor DTH. The aro- S. dublin strain CS101 could not be detected beyond day 28 post-inoculation in visceral organs including liver, spleen, mesentery, small intestine, caecum or large intestine of mice inoculated by the i.p. route or in mice inoculated by the oral route with the exception of day 42 post-inoculation. Challenge of mice previously immunized with 3 doses of the aro- S. dublin strain CS101 by the i.p. or oral route with virulent S. dublin strain CS90 resulted in their rapid clearance from the above visceral organs. Calves immunized with the aro- S. dublin strain CS101 by either the intramuscular (i.m.) or oral routes were significantly protected against oral challenge with virulent S. dublin strain CS90. In contrast to the observations in mice, somatic (O) and flagellar (H) antibody titres of calves immunized by either route were negligible as were anti-LPS antibody titres. However, flagellin-specific antibody titres were higher in calves immunized by the i.m. than the oral route. These results indicate that the protection observed in immunized mice or calves against oral challenge with virulent S. dublin was unlikely to have been mediated by humoral salmonella-specific immune mechanism(s).

Administration, Oral↗

PubMed1991

Generation of aromatic-dependent Salmonella havana and evaluation of its immunogenic potential in mice and sheep.

The generation of aromatic-dependent (aro-) Salmonella havana (Group G2, 01, 13, 23) from a smooth wild-type parent strain by transduction with phage P1 is reported. Mice immunized with this live aro- S. havana strain (CS234) by the intraperitoneal (i.p.) route were protected against challenge with wild-type S. havana, whereas those immunized by the oral route were not. Mice immunized with two doses of formalin-killed aro- S. havana by the i.p. route were also unprotected, in spite of high antibody titers. However, only those mice immunized with live aro- S. havana by the i.p. route developed significant delayed-type hypersensitivity. Following i.p. inoculation in mice, the aro- S. havana strain CS234 was detected in the liver, spleen and mesenteric lymph nodes on day 9 but not on day 15 post-inoculation (p.i.). On the other hand, when mice were inoculated with the parent wild-type strain (CS4) or the aro- derivative strain CS234 by the oral route, the organisms were recovered from the mesenteric lymph nodes and intestine only on day 3 but not on day 6 post-inoculation. In sheep inoculated with the aro- strain CS234 in the gastroc muscle, organisms were recovered from the muscle, and popliteal and medial iliac lymph nodes for up to 21 but not 28 days p.i. However, no mutant organisms were recovered from liver, spleen, mesenteric lymph nodes or faeces. In orally-inoculated sheep, the mutant organisms were recovered from the mesenteric lymph nodes, rumen, intestinal contents, and faeces up to 14-21 days post-inoculation but not at 28 days. When sheep immunised with the aro- S. havana strain CS234 by the intramuscular or oral route were challenged with the parent wild-type S. havana strain CS4 by the oral route, the latter strain was detectable in the mesenteric lymph nodes and faeces of immune sheep up to 14 days post-challenge in contrast with the non-immune sheep, where the challenge strain was detectable even at 28 days post-challenge. Only sheep immunized by the intramuscular route developed high antibody levels and delayed-type hypersensitivity.

Animals↗

PubMed1991

Genetic manipulation of Salmonella serotype Bovismorbificans to aromatic-dependence and evaluation of its vaccine potential in mice.

The generation of smooth aromatic-dependent Salmonella serotype Bovismorbificans (Group C2, O6, 8) from a smooth wild-type parent strain by transduction with phage P1, and conjugation with Salmonella serotype Typhimurium carrying F'-8gal is described. The smooth aromatic-dependent S. serotype Bovismorbificans was non-lethal for mice at an oral challenge dose of 2 x 10(9) cfu (equivalent to 200 LD50 of the parent, wild-type strain). The safety of the auxotrophic mutant was further substantiated by comparing its multiplication kinetics in vivo with that of its virulent parent organisms. Mice immunised with live, smooth aromatic-dependent S. serotype Bovismorbificans by either the oral or intraperitoneal (i.p.) route were protected against oral challenge with virulent S. serotype Bovismorbificans; the degree of protection was significantly better (p less than 0.05) at a challenge dose of 100 or 200 LD50 in mice receiving two rather than one vaccination. In contrast, mice immunised with three doses of the formalin-killed virulent, parent organisms by the i.p. route were not protected, in spite of high antibody titres. Only those mice immunised with the live, smooth aromatic-dependent S. serotype Bovismorbificans i.p. developed significant (p less than 0.01-0.05) delayed-type hypersensitivity.

Animals↗

PubMed1990

Evaluation of protection against experimental salmonellosis in sheep immunised with 1 or 2 doses of live aromatic-dependent Salmonella typhimurium.

The minimum number of doses of a live aromatic dependent (aro-) Salmonella typhimurium vaccine strain (SL1479), given by the intramuscular, oral or subcutaneous route required to protect sheep from experimentally-induced clinical salmonellosis, was determined. A significant reduction in mortalities and diarrhoea occurred in those sheep immunised with one or 2 intramuscular doses or 2 subcutaneous doses. On the other hand, sheep immunised with one subcutaneous dose were not protected. Immunisation with one or 2 oral doses also resulted in a significant reduction in mortality, although reduction in the prevalence of severe diarrhoea was less consistent. Sheep immunised with a single intramuscular dose of aro- S. typhimurium developed high levels of serum antibodies and significant delayed-type cutaneous hypersensitivity response to homologous Salmonella lipopolysaccharide and flagellin, whereas those with a single oral dose did not. It was concluded that immunisation of sheep with a single oral or intramuscular dose of live aro- S. typhimurium reduced mortalities and the prevalence of diarrhoea in sheep due to infection with virulent S. typhimurium.

Administration, Oral↗

PubMed1989

Relative importance of Salmonella-specific antibody isotypes in phagocytosis of Salmonella typhimurium by ovine mammary neutrophils.

The comparative opsonic efficiency of ovine salmonella-specific antibody isotypes was determined by measurement of specific phagocytic uptake of opsonised virulent Salmonella typhimurium by ovine mammary neutrophils. An in vitro phagocytosis assay revealed that IgM was superior to IgG2 in promoting the phagocytosis of opsonised virulent organisms. IgG1, on the other hand, was non-opsonic. Superiority of the IgM isotype over IgG2 as an opsonin was also evident in studies on the viability of opsonised S typhimurium upon phagocytosis. It was revealed that the percentage of organisms killed was appreciably greater when opsonisation was carried out with the IgM than with the IgG2 isotype, although after ingestion by neutrophils there was essentially no difference in the efficiency with which the ingested organisms were killed.

Animals↗

PubMed1988

Immune response of sheep to oral and subcutaneous administration of live aromatic-dependent mutant of Salmonella typhimurium (SL1479).

The major objective of the present study was to determine whether oral immunization with a live aromatic-dependent strain of Salmonella typhimurium (SL1479) was capable of stimulating an intestinal immune response in sheep similar to that induced by combined intraperitoneal injection followed by oral boosting. The results showed that repeated oral immunization was incapable of stimulating an anti-flagella antibody containing cell (ACC) response in the lamina propria of the intestine even though primary oral administration of 5 x 10(9) live SL1479 gave rise to an ACC response in intestinal lymph which was predominantly of the IgM isotype. ACC reached a peak 9-10 days after oral administration when ACC comprised 0.5-1% of total lymphocytes in lymph. An ACC response of similar isotope specificity also occurred in popliteal prefemoral lymph of unprimed sheep following regional subcutaneous injection of SL1479. Oral administration of SL1479 to orally primed sheep did not reinvoke an ACC response in lymph although IgG1-ACC were observed in medullary cords of mesenteric lymph nodes of sheep 6-8 days after the booster dose of SL1479. The results suggest that the protective immunity elicited by oral administration of SL1479 cannot be attributed to induction of a local intestinal antibody production.

Administration, Oral↗

PubMed1987

Alternative procedure for the purification of the heat-stable enterotoxin of enterotoxigenic Escherichia coli pathogenic for calves.

A method for purification of the heat-stable enterotoxin (ST) of enterotoxigenic Escherichia coli (ETEC) strains (C1444 and B41) pathogenic for calves and some physiochemical properties of the ST are described. The method involved ultrafiltration on PM-10 and UM-2 Diaflo membranes, acetone fractionation, ion-exchange chromatography on AG 1-X2, chromatofocusing and a combination of hydrophobic interaction chromatography on octyl-Sepharose CL-4B and gel-permeation on Bio-Gel P-2. Polyacrylamide gel electrophoresis in sodium dodecyl sulphate of fluorescamine-labeled purified, reduced and alkylated ST preparations revealed a single band with approximate molecular masses of 2500 and 2200 for the C1444 and B41 STs, respectively. For the C1444 ST, the final purification achieved was approximately 27,000-fold on the basis of absorbance at 280 nm per mouse effective dose. However, it was 2000-fold when calculated on the basis of mg protein per effective dose (5 ng). Amino acid composition of the C1444 ST was found to be different from that of the B41 ST suggesting that the ST produced by bovine isolates may be heterogeneous in their structure.

Animals↗

PubMed1987

Protection against experimental salmonellosis in mice and sheep by immunisation with aromatic-dependent Salmonella typhimurium.

Mice immunised by the oral or intraperitoneal route with a live aromatic-dependent strain of Salmonella typhimurium exhibited significantly less protection against oral challenge with 50 LD50 of an ovine isolate of S. typhimurium (12313) than when a bovine isolate with the same O antigens and phage-type as strain 12313 was used as the challenge organism. When challenged with 10 LD50, however, protection against both strains was significantly better than that obtained when mice were vaccinated with killed vaccines (heat-killed, acetone-killed or irradiated) even when the antigenic mass of the killed vaccine was increased by up to 500-fold in an attempt to compensate for the expected limited multiplication of the mutant organism. Sheep immunised with the live mutant strain by either the intramuscular or oral route were protected against oral challenge with the virulent ovine isolate of S. typhimurium; unimmunised sheep died of acute enteritis within 7 days, although there was no evidence of systemic invasion by the challenge organism. After challenge, immunised animals ate more food than the unimmunised controls and suffered only transient, mild diarrhoea. Serum antibody titres against O and H antigens measured by direct or antiglobulin tests were significantly higher in sheep immunised by the intramuscular route than in those immunised orally. Sheep in both immunised groups developed skin swellings within 30 min after intradermal inoculation with purified homologous lipopolysaccharide indicating development of immediate-type hypersensitivity, but only those immunised by the intramuscular route showed significant indurated skin swellings characteristic of delayed-type hypersensitivity 48 and 72 h post-inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1985

Purification and characterization of goblet-cell mucin of high Mr from the small intestine of sheep.

Crude soluble mucus from sheep small intestine was freed of nearly all the nucleic acid contaminants by precipitation with protamine sulphate and treatment with nucleases. After removal of non-covalently bound proteins by equilibrium density-gradient centrifugation in CsCl, a high-Mr glycoprotein was isolated by repeated h.p.l.c. from the partially purified mucin. The high degree of purity of the high-Mr mucin was borne out by (a) the observation of a single boundary on analytical ultracentrifugation in the presence of 5M-guanidinium chloride and (b) the observation of apparent monodispersity on sedimentation-equilibrium analysis. The Mr of the highly purified mucin, determined by sedimentation equilibrium, was 5.0 (+/- 0.1) X 10(6) and was concentration-independent. Finally, only goblet cells and the mucus blanket lining the intestinal epithelial cells were immunofluorescent when guinea-pig anti-(highly purified mucin) serum was used in an indirect immunofluorescence assay. The above antiserum reacted with apparently equal strength with goblet cells and with free mucin in abomasum, caecum and colon. The chemical composition of the glycoprotein was 66% carbohydrate and 34% protein, 45% of the latter being composed of valine and threonine. The glycoprotein migrated anodally on immunoelectrophoresis and contained 7.1% (w/w) sulphate. Neutral hexoses accounted for nearly half of the total carbohydrate content, followed by galactosamine and glucosamine. Whereas fucose and sialic acid were present in only small amounts, uronic acid was not detectable in the highly purified mucus glycoprotein.

Amino Acids↗

PubMed1984

Thermodynamics of hapten-antibody interactions.

Two schools of thought are currently prevalent regarding the thermodynamic mechanism(s) of hapten-antibody interaction(s). While one school is a proponent of the hapten-antibody reaction being driven predominantly by enthalpy, the second school rationalizes the mechanism as an enthalpy-entropy compensation, the magnitude of the latter being dependent on the temperature at which hapten-antibody interaction is carried out.

Animals↗