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Biomedical subjects

W H Traub

Publications and source records attributed to W H Traub.

At least 127 records · Page 7Linked to original sources
PubMed1977

Serotyping of Serratia marcescens: evaluation of Le Minor's H-immobilization test and description of three new flagellar H antigens.

The H-immobilization test of Le Minor for determining flagellar (H) antigens was evaluated and compared with tube and slide H-agglutination tests. The test proved specific and easy to perform, and titration end points were clearly discernible. The degree of serological cross-reactivity between H antigen reference strains of Serratia marcescens was low. Consequently, this test was adopted for routine serological analysis of H antigens, using unabsorbed rabbit immune anti-H sera. As a result of using this procedure, three new provisional H antignes, designated H14, H15, and H16, are proposed.

Antigens, Bacterial↗
PubMed1977

Inactivation of classical and alternative pathway-activated bactericidal activity of human serum by sodium polyanetholsulfonate.

Sodium polyanetholsulfonate (SPS) at a final concentration of at least 250 microng/ml (0.025%) was required for inhibition of the bactericidal activity of 80% (vol/vol) of fresh human serum against "promptly serum-sensitive" strains of Serratia marcescens and control strain Escherichia coli C, i.e., for inhibition of the classical pathway of complement activation. In contrast, SPS at 125 microng/ml (0.0125%) was sufficient for neutralization of the bactericidal activity of 80% (vol/vol) fresh human serum against "delayed serum-sensitive" strains of S. marcescens known to activate the alternative pathway of human complement. Addition of up to 500 microng of SPS per ml to 80% (vol/vol) fresh human serum failed to neutralize transferrin-mediated, "late" bacteriostasis against control strain E. coli C, an effect that was demonstrable only after prolonged, i.e., overnight, incubation of the test strain. However, this late inhibitory effect against E. coli C was not observed in SPS-treated 20% (vol/vol) fresh human serum or in 10 or 20% (vol/vol) conventionally heat-inactivated human serum. Immunoelectrophoretic examination disclosed that SPS did not precipitate transferrin from either fresh or heat-inactivated human serum. Thus, SPS, at 250 microng/ml, was demonstrated to be sufficient for the inhibition of both classical and alternative complement pathway-activated bactericidal activity of 80% (vol/vol) human serum. However, SPS at a concentration of 500 microng/ml failed to antagonize one antimicrobial system of 80% (vol/vol) human serum, namely transferrin-mediated bacteriostasis.

Benzenesulfonates↗
PubMed1977

Studies on neutralization of human serum bactericidal activity by sodium amylosulfate.

The synthetic anticoagulant sodium amylosulfate (SAS) at concentrations of 125 to 2,000 microgram/ml failed to completely neutralize the bactericidal activity of 80 and 50% (by volume) fresh human serum. Furthermore, SAS failed to inhibit the alternative pathway of complement activation in 80% (by volume) fresh human serum that had been chelated with 0.01 M magnesium ions plus 0.01 M ethyleneglycol-bis(beta-aminoethylether)-N,N-tetraacetic acid. However, SAS at 250 to 1,000 microgram/ml effectively neutralized the bactericidal activity of 20% (by volume) fresh human serum. Therefore, SAS (at 250 to 1,000 microgram/ml) should be used only in blood samples that have been diluted at least fivefold (less than or equal to 20% [by volume]) in suitable broth media.

Amylopectin↗
PubMed1976

Selective activation of classical and alternative pathways of human complement by "promptly serum-sensitive" and "delayed serum-sensitive" strains of Serratia marcescens.

Chelation of fresh human serum with 0.01 M MgCl2 (Mg) plus 0.01 M ethylene glycol tetraacetic acid failed to abrogate the bactericidal activity against "delayed serum-sensitive" strains of Serratia marcescens, whereas previously "promptly serum-sensitive" strains of S. marcescens and control strain Escherichia coli C were killed after an extended period of incubation. The addition of 0.01 M ethylenediametetracetate to fresh human serum neutralized bactericidal activity against S. marcescens of either serum sensitivity category.

Blood Bactericidal Activity↗
PubMed1976

Ultrastructural surface alterations of serratia marcescens after exposure to polymyxin B and/or fresh human serum.

Exposure of Serratia marcescens cells to 10, 5, and 2.5 mug/ml of polymyxin B resulted in outer cell surface alterations that consisted of coarse, pleomorphic projections which revealed a double-contoured membrane structure. In contrast, fresh, but not heat-inactivated human serum caused the deposition of very fine, thread-like aggregates on the outer cell surface of exposed cells. The combination of polymyxin B and fresh human serum caused clearly discernible ultrastructural changes of the polymyxin and the fresh serum type, respectively.

Cell Wall↗
PubMed1976

Characterization of a nosocomially significant, multiple drug-resistant strain of Serratia marcescens.

A multiple drug-resistant strain of Serratia marcescens (bacteriocin type 18) was isolated from three clinical patients. The isolates were found to carry a conjugally nontransferable, nonmobilizeable resistance plasmid (R-plasmid) with resistance-(r)-determinants against ten antimicrobial drugs: ampicillin, carbenicillin, chloramphenicol, gentamicin, kanamycin, neomycin, streptomycin, tobramycin, triple sulfonamides, cotrimoxazole, and--possibly--nalidixic acid, as determined with exposure to 'curing' agents (ethidium bromide, acridine orange, and sodium dodecyl sulfate) and by the high rate of spontaneous loss of r-determinants. Dyebuoyant density centrifugation allowed recovery of R-plasmid DNA that measured roughly 24 mum in contour length; after 'curing' with concomitant loss of 9 r-determinants, the contour length of the R-plasmid DNA of one isolate (No. SE 154) had decreased to roughly 15 mum, and none was detected in the sole variant of the isolate that spontaneously had lost 11 r-determinants.

Ampicillin↗
PubMed1976

Studies on group A (phage tail) bacteriocins of Serratia marcescens. V. Serological characterization of subgroup I and II bacteriocins.

Neutralization tests with rabbit hyperimmune sera revealed a close, if not identical, serological relationship among 7 group A (phage tail) bacteriocins of Serratia marcescens of subgroup I, and among 3 phage tail bacteriocins of subgroup II, respectively. On the other hand, subgroup I and II phage tail bacteriocins were found to be serologically unrelated, as determined with neutralization tests and Ouchterlony immunodiffusion experiments. Immunoelectrophoretic tests, employing a representive phage tail bacteriocin of each of the two subgroups, disclosed the electrophoretic mobility of bacteriocin no. 5 (subgroup I), whereas bacteriocin no. 16 (subgroup II) remained stationary. Thus, two additional differential criteria, i.e., differences in antigenicity and electrophoretic mobility, were obtained for the characterization of subgroup I and II group A (phage tail) bacteriocins of S. marcescens.

Animals↗
PubMed1976

Studies on group A (phage tail) bacteriocins of Serratia marcescens. VI. Calcium ion-dependent biological activity of subgroup II bacteriocins.

The biological activity of subgroup II group A (phage tail) bacteriocins of Serratia marcescens against susceptible indicator cells was completely abolished on two defined, Agarose-containing media. The addition of 0.002 M CaC12 to these two media fully restored the lethal activity of these phage tails. Subgroup I phage tail bacteriocins, on the other hand, were found to have no requirement for divalent cations. These observations furnished an additional biological criterion for the differentiation of subgroup I and II phage tail bacteriocins of S. marcescens.

Bacteriocins↗
PubMed1975

Studies on the additive effect of polymyxin B and the bactericidal activity of human serum against Serratia marcescens.

Two of twelve examined S. marcescens strains were promptly killed by 80% (v/v) fresh human serum (within 20 min), analogous to a serum-sensitive control strain of Escherichia coli; ten strains, however, were killed by fresh serum only after extended incubation (2-4 h). The combination of therapeutically achievable concentrations of polymyxin B (range 5 to 1.25 mug/ml) and fresh, but not heat-inactivated human serum was found to exert an accelerated, additive effect against 9 of 10 'delayed serum-sensitive' isolates of S. marcescens, an organism that is characterized by intrinsic resistance against polymyxins. The combination of 80% (v/v) fresh, defibrinated human blood and polymyxin B likewise resulted in an additive effect. Polymyxin B treatment of S. marcescens strains caused a prompt, marked, though reversible bile salt susceptibility of the cells; in contrast, the effect induced by fresh serum was slight and not apparent until several hours after exposure.

Animals↗