Comparison of organophosphorous acid anhydrolases from different species using monoclonal antibodies.

1. Monoclonal antibodies were raised against squid hepatopancreas organophosphorous acid (OPA) anhydrolase (EC 3.1.8.2) and were used to study structural similarities with OPA anhydrolases isolated from different sources. 2. Common epitopes were identified in OPA anhydrolases with diverse origins, and with different substrate specificities. 3. Epitopes unique to the squid hepatopancreas OPA anhydrolase were identified; optic ganglion and hepatopancreas contain different enzymes which can be distinguished by their epitopes.

Factors influencing invasion of erythrocytes by Plasmodium falciparum parasites: the effects of an N-acetyl glucosamine neoglycoprotein and an anti-glycophorin A antibody.

When schizont-infected erythrocytes were incubated with N-acetyl glucosamine coupled to bovine serum albumin (GluNAc-BSA), the number of new ring forms which appeared several hours later was reduced and the number of abnormal and unruptured schizont-infected erythrocytes was increased compared with controls, indicating that GluNAc-BSA prevents invasion by a toxic effect on schizonts rather than by receptor blockade. Invasion of erythrocytes by Plasmodium falciparum was inhibited by a monoclonal antibody against glycophorin A, but inhibition also occurred with P. knowlesi, a parasite that is known to invade independently of glycophorin A. Inhibition of invasion with anti-glycophorin A is unlikely to be related to receptor blockade and is probably related to decreased deformability of the erythrocyte membrane caused by the binding of this antibody. Previous studies suggesting that GluNAc-BSA and anti-glycophorin A antibodies inhibit invasion by receptor blockade should be reevaluated. Erythrocytes deficient in glycophorin C and band 4.1 were also resistant to invasion by both P. falciparum and P. knowlesi.

Monoclonal antibodies reactive with K1-encapsulated Escherichia coli lipopolysaccharide are opsonic and protect mice against lethal challenge.

Seven murine monoclonal antibodies (MAbs) directed against O-side-chain determinants of the K1-encapsulated Bortolussi strain of Escherichia coli (O18:K1:H7) were evaluated for their in vitro and in vivo activities. All the MAbs reacted well in Western blots against E. coli O18 lipopolysaccharide antigens. Two MAbs of the immunoglobulin G (IgG) class promoted in vitro opsonophagocytosis and protected mice lethally challenged with bacteria. Two IgM MAbs showed partial protection, although they had no in vitro opsonic activity, and the remaining three IgM MAbs showed no apparent functional activities. Monoclonal IgG antibodies against bacterial lipopolysaccharide can be opsonic and protective in spite of the presence of the K1 capsule on the bacterium.

Characterization of mouse monoclonal antibodies directed against Pseudomonas aeruginosa lipopolysaccharides.

Mouse monoclonal antibodies that react with O-side chain specific, O-side chain cross-reactive, and core P. aeruginosa lipopolysaccharide determinants have been isolated. The monoclonals directed at O-side chain determinants are generally opsonophagocytic with human neutrophils and human complement. They also protect mice from intraperitoneal and intravenous challenge and protect in the burned rat model of infection.

Comparison of the Phadebact Gonococcus Test with the rapid fermentation method.

The Phadebact Gonococcus Test (Pharmacia Diagnostics, Piscataway, N.J.), a coagglutination technique, was compared with the rapid fermentation method of Kellogg and Turner (D. S. Kellogg, Jr., and E. M. Turner, Appl. Microbiol. 25: 550--552, 1973). A total of 93 organisms isolated on Martin-Lewis media were determined to be Neisseria gonorrhoeae based on the following criteria: presence of gram-negative diplococci, oxidase positivity, and appropriate reaction in the rapid fermentation method. These 93 isolates were then serologically tested with the Phadebact test. The direct method was attempted on the first 46 N. gonorrhoeae isolates. Difficulty in interpreting results was encountered in 39%. Thereafter, the alternate method of boiling was instituted on an additional 47 N. gonorrhoeae isolates, with 2 isolates producing noninterpretable results. All 93 isolates were frozen for a maximum of 2 months in skim milk at -25 degrees C. These isolates were thawed and retyped with the alternate boiling procedure, with 97% being confirmed as N. gonorrhoeae. In addition, 33 Neisseria meningitidis isolates, 14 Neisseria species, and 7 Moraxella species were tested with similar techniques. No positive reactions were observed. A cost effectiveness study using 5, 10, and 20 microliters of the gonococcal reagent was undertaken to reduce the cost of the test. When 10 and 20 microliters of reagent were used, no difficulty was encountered in interpreting the reaction. The coagglutination technique was difficult to read when 5 microliters of reagent was used.