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W H Jansen

Publications and source records attributed to W H Jansen.

At least 37 records · Page 2Linked to original sources
PubMed1988

Infection and immunity to Vibrio cholerae, Salmonella typhimurium and Escherichia coli in a rabbit model.

Cholera disease can be induced in the rabbit by duodenal inoculation (DI) of Vibrio cholerae organisms after ligation of the cecum (C) (DIC model). When ligation of the cecum is omitted, no disease symptoms develop. In contrast, the animals are primed which becomes apparent as vibriocidal protection upon challenge with V. cholerae in the DIC model. This protection coincides with high anti-O antigen IgA levels in the bile. The O antigen was shown to be the protective antigen and it must be presented by live organisms. A non-enterotoxigenic mutant of V. cholerae induced protective immunity in the rabbit but was reported to cause mild diarrhea in human volunteers. Looking for alternatives, we applied cholera toxin, known as a mucosal adjuvant, together with killed V. cholerae cells to rabbits. Unfortunately, the minimum adjuvant dose was equal to the minimum toxic dose. A Salmonella typhimurium strain expressing also the V. cholerae O antigen induced systemic rather than local immunity which was not protective. Several Escherichia coli strains were able to elicit a local immune response, but the animal to animal differences were considerable. Therefore, V. cholerae itself was thought to be the most appropriate carrier organism. Some non-enterotoxigenic and auxotrophic mutants of V. cholerae were able to prime and did not show any undesired side-effects in the DIC model. Therefore, further attenuation of non-toxigenic V. cholerae strains by means of stable deletions in nutritional genes seems to be the most promising way to obtain acceptable vaccine candidates.

Adjuvants, Immunologic↗
PubMed1988

Value of the Widal test in the diagnosis of typhoid fever in an endemic area and suggestions for a modification. A preliminary study.

The Widal test for detection of typhoid fever was introduced in two rural hospitals in Nigeria. Because of undetectably low O agglutination titers, 74 sera were sent overseas for further determination by means of passive haemagglutination with O 9, 12-antigen, Vi-antigen and slide agglutination with H-d antigen suspensions. This full test showed discrepancies with the normal Widal test i.e. a false negative Widal H agglutination in 6 out of 17 patients in West Nigeria and a false positive Widal H test in 28 out of 49 patients in Central Nigeria. The full test should be applicable in a small laboratory, but its value has yet to be established.

Antigens, Bacterial↗
PubMed1987

Immunoglobulins in bile and serum of the rabbit associated with protection after Vibrio cholerae infection and vaccination.

Previous studies have shown that cholera, as well as protective immunity against infection with Vibrio cholerae, can be induced in the rabbit. This protection is long-lasting (up to 30 months) and is characterized on challenge by rapid, symptom-free disappearance of V. cholerae from the intestine; we therefore believe this to be vibriocidal protection. In this study, we analysed the humoral and secretory immune response against various subcellular V. cholerae components in vibriocidally protected, non-vibriocidally protected, and unprotected animals. Only vibriocidal protection was found to be associated with high levels of biliary IgA directed against lipopolysaccharide O antigen. We did not find such a correlation between either type of protection and response in serum. Therefore, anti-lipopolysaccharide antibodies are essential in protection against experimental infection with V. cholerae.

Agglutination Tests↗
PubMed1987

Serotyping of Serratia marcescens using passive haemagglutination.

Serratia marcescens O antisera prepared with boiled bacterial suspensions gave relatively low titers when tested with boiled broth cultures in tube or tray agglutination tests, but extremely high titers when tested in the haemagglutination test with conserved sheep erythrocytes coated with alkali-treated heat extract. However, an antiserum prepared with boiled O group 6 bacteria, did not react at all. A proper O6 antiserum could only be prepared if the O6 cells were not heated at 100 degrees C. The antigenic relationships between standard strains of S. marcescens were investigated by means of haemagglutination tests. The antigenic relationships already described in the literature were confirmed. Additional reciprocal relationships were observed, some of which could be explained by 8 antigenic factors which are designated I-VIII. O antisera could be made monospecific by absorption. It was confirmed that standard strain O6H3 has two antigenic determinants which should be written as O6ab, that standard strain O6H8 has O6bc and that O14 has O6b. Standard strain O7 was found to possess O6a in addition to the specific determinant O7, whereas the antigen O6c turned out to be identical with O8. The standard strain O14 has, in addition to O6b only the factor hitherto described as Co12, 13, 14 and no specific O14 antigen. We propose to redesignate Co12, 13, 14 as O14 and to write the formula of O12 and O13 strains possessing this antigen as O12, 14 and O13, 14 respectively. O antigen O23 should then be written as O14, 23. For similar reasons we propose to redesignate Co2, 3 as O25. The O antigen O20 was found to be related to the antigens O16ab, O16ac and O16acd in such a way that it should be written O16ae. For similar reasons O22 should be written as O10ac. When serotyping Dutch isolates of Serratia marcescens, hitherto undescribed antigenic combinations such as O2, 16ab; 03, 6a; O3, 21 and O4, 6b were encountered. For H antigen typing we found the slide agglutination with cultures grown on semisolid medium the most appropriate.

Agglutination Tests↗
PubMed1987

Protective immunity against Vibrio cholerae infection in the rabbit.

The DIC model (Duodenal Inoculation with ligation of the Cecum in rabbits) was employed to study experimentally induced cholera and the related protective immunity. Duodenal inoculation (DI) without ligation of the cecum with live V. cholerae organisms did not cause any disease symptom but induced protection against subsequent challenges with homologous and heterologous organisms for up to 24 months. After 30 months this protective immunity began to decrease. A similar protective immunity could be induced by administration of the A- B+ derivative CVD101 of V. cholerae strain 395. This type of experiment can only be done successfully with conventional, healthy rabbits held under low stress conditions. A so-called specific pathogen-free rabbit breed was found to be entirely unsuitable. Duodenal inoculation with heat- or merthiolate-inactivated V. cholerae for a prolonged period of time by means of an intestinal osmotic minipump did not induce protection. Injection of heat-inactivated V. cholerae material into the Peyer's patches sometimes led to protection, suggesting that a thermostable antigen, possibly lipopolysaccharide, is one of the major protective antigens. Duodenal administration of a combination of inactivated V. cholerae serotypes Ogawa and Inaba cells and 1 mg B subunit of the V. cholerae enterotoxin by up to three inoculations protected only 3 out of 12 rabbits against challenge. The results obtained on the rabbit model are discussed in relation to the efficacy of this vaccine in human volunteers and in a recent field test.

Animals↗
PubMed1987

Serotyping of Aeromonas species using passive haemagglutination.

Antisera were raised with heat-killed vaccines prepared from 25 Aeromonas hydrophila strains, 4 A. sobria strains and one A. caviae strain. Twenty-seven of these 30 antisera gave high titers when tested in the microtiter tray agglutination (MTA) test with their homologous antigen heated at 100 degrees C for 30 min. Three O antisera gave low titers in the MTA test but reacted to high titers in the haemagglutination (HA) test with conserved sheep red blood cells coated with alkali-treated heat extract. All 27 antisera showing high titers in the MTA test, showed even higher titers in the HA test. Therefore, the HA technique was employed to type 306 strains isolated from surface and drinking water, from food samples and from faeces of human patients with diarrhea. Of 155 A. hydrophila strains 21 (14%) could not be typed. For A. sobria and A. caviae, the percentage of untypable strains was 46% and 68% respectively. Many A. sobria and A. caviae strains reacted to titer in A. hydrophila O antisera. A limited number of strains reacted to titer in more than one specific O antiserum. Immunoelectrophoretic studies indicated that the O antigen is often represented by more than one precipitation line and that true K antigens occur in Aeromonas.

Aeromonas↗
PubMed1986

Monoclonal antibodies against the K99 antigen of Escherichia coli for diagnostic purposes.

Hybridomas secreting monoclonal antibodies against the K99 antigen of Escherichia coli were produced by the fusion of spleen cells from immunized BALB/c mice with P3/X63-Ag8.653 myeloma cells. The seven hybridomas which produced the highest antibody titers in vitro, as detected by enzyme-linked immunosorbent assay (ELISA) and Perma slide agglutination test (PSAT), were chosen for antibody production in vivo. No cross reaction was observed with K88ab, F41 and P987 antigens in the ELISA. The titer of each ascitic fluid was established by the ELISA and the slide agglutination (SAT) tests. The two ascitic fluids with the highest titer in the SAT were incorporated into the set of antisera used for serotyping at our laboratory. The results were satisfactory both in terms of stability and specificity.

Agglutination Tests↗
PubMed1985

Vibrio cholerae infection and acquired immunity in an adult rabbit model.

We modified the rabbit model for enteric infection by Vibrio cholerae developed by Spira et al. and designated the RITARD (for removable intestinal tie-adult rabbit diarrhea) model (20). Our modification DISC comprises a permanent ligation of the cecum (C) to prevent resorption of the fluid secreted by the small intestine, a temporary ligation of the small intestine (S) to enable the bacteria to colonize, and duodenal inoculation (DI) of the challenge material. The main difference between RITARD and DISC is that in the latter model the challenge material is injected into the duodenum approximately 10 cm distal to the stomach instead of into the jejunum. Four out of 5 V. cholerae strains tested, including 2 serotypes and 2 biotypes, were able to elicit a massive and usually fatal cholera-like diarrhea. The virulence depended strongly on the culturing conditions. One strain, C5, caused fatal diarrhea in a dose of about 1000 organisms, even if the temporary ligation was omitted (DIC model). Other modifications were the DIS and the DI model in which the permanent ligature of the cecum or both ligatures were omitted. Duodenal inoculation of organisms in a dose of 100 X the minimum infective dose (MID) in the DIS or DI model did not cause any disease symptom. However, such inoculations were found to cause protection against subsequent challenges with 100 X MID of homologous and heterologous organisms up to 52 weeks after duodenal inoculation. Subcutaneous injection with classical, whole cell cholera vaccine gave only partial protection of short duration. This model might contribute to the understanding of the pathogenesis of cholera as well as to the improvement of efficacy testing of cholera vaccines.

Animals↗
PubMed1983

Mechanized procedures for the serology of Salmonella.

A mechanized microtechnique originally designed for the serotyping of E. coli was adapted to the specificity control of diagnostic Salmonella agglutinating antisera as well as for the serotyping of Salmonella. Salmonella strains sent for serotyping were inoculated into a tube with broth which was used as H antigen and, after heating also as O antigen. The agglutination reactions were carried out in clear plastic trays with U formed wells. The antigens were strained with gentian violet in order to obtain a better contrast. With only 6 monofactor O sera, 97% of 100,000 cultures received for serotyping in 1979-1982 could be O antigen typed. Eight H antisera were sufficient for the complete serotyping of 27% of these strains whereas 64% was partly typed. The technique has a high degree of versatility.

Antigens, Bacterial↗
PubMed1980

Virulence of Escherichia coli in acute pyelonephritis, acute cystitis and asymptomatic bacteriuria.

E. coli strains were isolated from urine specimens of hospitalised patients with acute pyelonephritis, acute cystitis or asymptomatic bacteriuria (ABU), and tested for virulence in an experimental mouse model. Of 12 pyelonephritis-strains 11 were shown to be virulent and 1 avirulent; of 12 cystitis-strains 4 were virulent and 8 avirulent; of 12 ABU-strains 5 were virulent and 7 avirulent. It is concluded that, while no difference in virulence was found between cystitis- and ABU-strains, pyelonephritis-strains were more often virulent than cystitis- and ABU-strains. No associations could be shown between virulence of the isolated strains and the presence of antibody-coated bacteria in the urine. Common urinary O types were not more often virulent than other O types. No relationship was seen between virulence and the presence of K antigen or the presence of particular K types.

Acute Disease↗
PubMed1980

Some characteristics of the outer membrane material released by growing enterotoxigenic Escherichia coli.

The high-molecular-weight material released into the medium by Escherichia coli AP1, an enterotoxigenic strain of porcine origin, has been isolated and resolved into two clearly distinct fractions, based on sucrose density gradient and differential centrifugation, chemical analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and freeze-fracture electron microscopy. These two fractions, referred to as "medium vesicles" and "medium lipopolysaccharides", were compared with the cellular outer and cytoplasmic membranes, the periplasmic fraction, and the cytoplasmic fraction. The medium vesicles closely resembled outer membrane and accounted for 3 to 5% of the total cellular outer membrane. They contained most of the heat-labile enterotoxin (LT) activity released into the medium by E. coli AP1. The medium lipopolysaccharide consisted mostly of lipopolysaccharide and a small amount of outer membrane and contained relatively little LT activity. Based on experiments with E. coli K-12 strains, in which about 5% of the newly synthesized outer membrane is lost from areas of outer membrane synthesis, it is proposed that enterotoxigenic E. coli strains release LT as part of such newly synthesized outer membrane fragments and that released outer membrane fragments may function as physiologically significant LT carriers.

Centrifugation, Density Gradient↗
PubMed1980

Mechanized technique for phage typing and determination of antibiograms.

A device for mechanical application of either drops of phage suspensions or antibiotic-containing tablets was developed. The device consists of a Transport Apparatus which transports petri dishes from one side of the apparatus to the other in such a way that the plate and the lid of a petri dish become entirely separated at a particular stage. Either a Phage Applicating System or an Antibiotic Tablet Dispenser can be connected to the apparatus. In this way a maximum of 27 phages of 7 antibiotic tablets per plate can be applied pneumatically.

Anti-Bacterial Agents↗
PubMed1979

Behavior of Escherichia coli K antigens K88ab, K88ac, and K88ad in immunoelectrophoresis, double diffusion, and hemagglutination.

Porcine enteropathogenic Escherichia coli strains were found to possess a variant of the K88 antigen provisionally termed K88ad. We propose to include this antigen into the international E. coli typing scheme. Ultrasonic extracts of field strains of E. coli possessing the K88ab, K88ac, or K88ad antigen and their E. coli K-12 K88+ transconjugants showed a specific K88 precipitation line in immunoelectrophoresis and double diffusion only when grown at 37 degrees C, but not when grown at 18 degrees C. By using agarose gels, K88ab, K88ac, and K88ad antigens showed anodic mobility in immunoelectrophoresis. When using Difco Noble agar gels, K88ad was not mobile or anodic, K88ab was cathodic; K88ac of 17 strains was cathodic and of 24 strains was anodic. The immunoelectrophoretic behavior of a K88 antigen (K88ab, K88ac, or K88ad) did not alter after transfer of the corresponding plasmid to E. coli K-12. Anodic and cathodic K88ac antigens could not be distinguished serologically. The differences between the results obtained in Noble agar gels and agarose gels are due to electro-endosmotic flow. We describe a procedure which increases the detection level of K88+ transconjugants in a mating mixture. It is based on the specific mannose-resistant attachment of K88+ cells to guinea pig erythrocytes.

Animals↗
PubMed1979

Detection of enterotoxigenicity and attachment factors in Escherichia coli strains of human, porcine and bovine origin; a comparative study.

Porcine and bovine strains of E. coli suspected to be enterotoxigenic, were tested for heat-labile enterotoxin (LT) production by means of a test measuring the stimulation of the synthesis of 3151 cyclic adenosin monophosphate (cAMP test) and rounding mouse adrenal tumor Y1 cells (Y1 test), and for heat-stable enterotoxin (ST) production by means of the baby mouse test (BM test). The test results were compared with those of the ligated gut test (LG test) using pig and calf intestine. One hundred and eleven strains of human origin were tested in the cAMP test, the Y1 test and the BM test. All strains were tested for the presence of the attachment factors K88, K99, P987 and CF10407. Seventy-four of 117 bovine strains produced only ST and all 74 ST-producing strains possessed K99 antigen. None of the 43 nonenterotoxigenic strains possessed K99. The presence of K99 antigen is therefore a reliable indicator of enterotoxigenicity in bovine strains. Porcine strains produced LT, ST or LT + ST. The K88 antigen was found in 52 out of 101 enterotoxigenic strains, K99 and P987 in 7 and 6 strains respectively and the latter 13 strains produced only ST. P987 was only detected after subculturing in liquid medium to enhance pilus formation. Eleven out of 111 strains of human origin stimulated cAMP synthesis but failed to round Y1 cells, whereas 4 known LT producers were positive in both tests. Attachment factors were found only in 2 of the latter 4 strains.

Animals↗
PubMed1978

Isolation of the membranes of an enterotoxigenic strain of Escherichia coli and distribution of enterotoxin activity in different subcellular fractions.

The intracellular localization of enterotoxin in Escherichia coli AP1, a strain of porcine origin which produces high levels of heat-labile, but no heat-stable enterotoxin, has been examined. The cytoplasmic and outer membranes of this strain both contained enterotoxin activity, while the membranes isolated from a serologically related non-enterotoxigenic strain (E. coli AP2) also of porcine origin, did not show enterotoxin activity. The periplasmic fraction isolated from the enterotoxigenic strain contained considerable enterotoxin activity, but this activity was associated with outer membrane fragments present in the periplasmic fraction. Thus, of the total cellular enterotoxin activity, about 55%, 15% and 30% were present in the outer membrane, cytoplasmic membrane and the cell cytoplasm, respectively. The specific activity of enterotoxin was 20 units per mg protein in the cytoplasm and 90 and 150 units per mg protein in the cytoplasmic and outer membranes, respectively.

Biological Assay↗
PubMed1977

Serological identification of pig enterotoxigenic Escherichia coli strains not belonging to the classical serotypes.

Escherichia coli strains isolated from pigs suspected to have succumbed to E. coli enterotoxicosis and not belonging to the commonly incriminated (classical) serotypes (O8:K87:K88, O45:K88, O138:K81:K88, O141:K85:K88, O147:K89:K88, O149:K91;K88, and O157:K88) were tested for enterotoxigenicity in the ligated gut test (LGT) using pig intestine. Of 202 strains tested, 54 strains belonging to 13 different O groups were positive in the LGT. Four of these strains had K88 antigen and one possessed K99 antigen. The majority of the strains was not agglutinated by any of the standard OK antisera. Four new K antigens ("K200", "K442", "K2346" and "K2347") were provisionally designated. K200 was found in pig enterotoxigenic strains belonging to O group 8 and carrying flagellar antigen H31 and in non-enterotoxigenic non-motile strains of O group 8, as well as in O group 20 strains isolated from calves succumbing to E. coli septicemia in two countries. The provisional antigen K2346 was encountered in 18 enterotoxigenic strains with various O antigens from two countries. It is proposed to include these two K antigens into the international E. coli antigens scheme. Attempts to demonstrate a common antigen in the nonclassical enterotoxigenic strains lacking K88 and K99 antigens failed.

Animals↗