bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of optimal mucosal antibody responses: effects of age, immunization route(s), and dosing schedule in rats
Authors: Pierce N F
Published: January 2020

The antitoxin response in intestinal mucosa was studied in rats immunized either intestinally or by combined parenteral and intestinal dosing with cholera toxin or cholera toxoid. Attention was given to the duration of enteric priming and the magnitude and time course of mucosal anti-cholera toxin responses in rats of defined age. Cholera toxin given only intraduodenally was a more efficient priming immunogen in young rats than in older rats and caused priming that lasted at least 32 weeks; repeated enteric doses increased local priming and repeatedly evoked vigorous mucosal anti-cholera toxin responses which occurred rapidly and declined slowly. Results differed when a portion of the immunizing regimen was parenteral. Cholera toxoid given intraperitoneally (i.p.) caused mucosal priming that peaked promptly and then rapidly declined; parenteral boosting after enteric priming was much more effective given i.p. than subcutaneously; moreover, the booster response was brief, virtually disappearing within 11 days, and could not be reproduced by a second i.p. immunization. These results accord with evidence that parenteral immunization both stimulates and suppresses mucosal secretory immunoglobulin A responses, whereas local immunization is not known to be suppressive. Evidence for parenterally induced suppression was the rapid decline in mucosal priming after i.p. immunization, the shortened mucosal antibody response after i.p. immunization, and possibly the inability to parenterally evoke a booster response twice. In these studies, the level of priming observed at different intervals after parenteral, enteric, or combined immunization appeared to reflect the sum of priming and suppressive effects evoked by the preceding immunization(s).
Teratogenicity of Australian Simbu serogroup and some other Bunyaviridae viruses: the embryonated chicken egg as a model
Authors: McPhee D A , Parsonson I M , Della-Porta A J , Jarrett R G
Published: January 2020

The use of embryonated chicken eggs as a model for assessing the teratogenic potential of animal viruses was investigated with 12 members of the Bunyaviridae family. Infection of 4-day-old embryonated chicken eggs via the yolk sac with 10 of the viruses resulted in deaths or congenital deformities that were similar to those observed in Akabane virus infections of fetal ruminants and included arthrogryposis, scoliosis, mandible defects, and retarded development. Statistical analysis showed that the viruses fell into three main groupings, namely, those that caused both death and deformities (Akabane, Aino, Tinaroo, and Belmont viruses), those that mainly caused death (Peaton, Thimiri, and Facey's Paddock viruses), and those that required very high doses to cause either death or deformities (Douglas and CSIR0296 viruses). In addition, two viruses (Kowanyama and Mapputta viruses) caused neither death nor deformities. A difference in the pathogenic potential between two Akabane isolates (B8935 and CSIR016) in the embryonated chicken egg model was found to correlate with differences previously observed in experimentally infected sheep; Akabane CSIR016 was the more pathogenic. It is concluded that the embryonated chicken egg model should also be of value in assessing the teratogenic potential of other Bunyaviridae and attenuated vaccine viruses, although it does not assess the ability of the virus to cross the placenta.
Production of gamma interferon in mice immune to Rickettsia tsutsugamushi
Authors: Palmer B A , Hetrick F M , Jerrells T J
Published: January 2020

C3H/He mice immunized by subcutaneous infection with Rickettsia tsutsugamushi Gilliam were examined for the production of immune interferon after intravenous administration of irradiated strain Gilliam antigen, in supernatants of immune lymphocytes stimulated with specific antigen, and after a secondary challenge with viable rickettsiae. Mice administered various doses of irradiated whole-organism antigen 28 days after immunization showed circulating levels of interferon which peaked 4 h after inoculation and were antigen dose dependent. The interferon produced was pH 2 sensitive and stable at 56 degrees C for 1 h and was neutralized by antiserum directed against immune, but not against alpha/beta, interferon. The production of another lymphokine, macrophage migration inhibition factor, paralleled that of interferon. The interferon produced by cultures of spleen cells obtained from immune animals was antigen specific and dose dependent. Peak levels were obtained 48 to 72 h after the addition of antigen. The interferon produced by spleen cell cultures after stimulation with Gilliam antigen was characterized as immune interferon by the same physical and antigenic criteria used for serum interferon. Interferon was produced in vitro by the Thy-1.2+ lymphocyte and required the presence of a spleen-adherent cell population. Immune mice produced high circulating levels of immune interferon after intraperitoneal challenge with viable rickettsiae, which suggested a possible role for interferon in the resistance of immune mice to rechallenge with R. tsutsugamushi.
Pathogenesis of experimental salmonellosis: inhibition of protein synthesis by cytotoxin
Authors: Koo F C , Peterson J W , Houston C W , Molina N C
Published: January 2020

Salmonella cytotoxin present in cell lysates inhibited protein synthesis in both Vero cells and isolated rabbit intestinal epithelial cells. A time-course experiment with Vero cells revealed progressive inhibition of protein synthesis beginning as early as 1 h after exposure to the Salmonella cell lysate. Significant loss of membrane integrity of Vero cells (measured by release of [3H]uridine) did not appear before 24 h. To demonstrate inhibited protein synthesis in intestinal tissue during experimental salmonellosis, we isolated rabbit epithelial cells from Salmonella-infected and control intestinal loops. Measurement of [3H]leucine incorporation showed a similar decrease in protein synthesis in epithelial cells from the Salmonella-infected intestinal loop as that from an adjacent control loop. A similar pattern of protein synthesis inhibition was observed when isolated epithelial cells from normal rabbit intestine were exposed to the Salmonella cell lysate. The inhibited protein synthesis in the intestinal cells provides a molecular basis for the cellular damage caused by Salmonella cytotoxin during experimental salmonellosis.
Killing of Plasmodium yoelii by enzyme-induced products of the oxidative burst
Authors: Dockrell H M , Playfair J H
Published: January 2020

The murine malaria parasite Plasmodium yoelii was killed in vitro when incubated with glucose and glucose oxidase, a system generating hydrogen peroxide, or with xanthine and xanthine oxidase, a system which produces the superoxide anion and subsequently other products of the oxidative burst. Catalase blocked the killing in both cases; superoxide dismutase and scavengers of hydroxyl radicals or singlet oxygen were ineffective in the xanthine oxidase system. Thus, hydrogen peroxide appears to be the main reactive oxygen species killing P. yoelii.
Virulence factors of Haemophilus ducreyi
Authors: Odumeru J A , Wiseman G M , Ronald A R
Published: January 2020

We investigated the susceptibility of virulent and avirulent strains of Haemophilus ducreyi to the bactericidal activity of normal human serum and to phagocytosis and killing by human polymorphonuclear leukocytes (PMNL). Strains were defined as virulent if intradermal inoculation into a rabbit produced a typical necrotic lesion. Nonvirulent strains produced no cutaneous lesions in rabbits. Virulent strains were resistant to the complement-mediated lethal action of normal human and rabbit sera, whereas avirulent strains were susceptible (greater than 95% kill, 60 min). Virulent strains were relatively resistant to phagocytosis and killing by human PMNL, in contrast to the avirulent strains. In past studies polymyxin resistance has been correlated with virulence in H. ducreyi. In our studies, polymyxin resistance could not be correlated with virulence, since polymyxin-sensitive mutants obtained from polymyxin-resistant parent strains remained virulent for rabbits and resistant to bactericidal action of normal serum and phagocytosis and killing by human PMNL. Similarly, polymyxin-resistant mutants obtained from polymyxin-sensitive parent strains remained avirulent for rabbits and susceptible to bactericidal action of normal serum and PMNL. The acquisition of polymyxin resistance was accompanied by the loss of a 47,000-molecular-weight protein. The association of serum resistance and resistance to phagocytosis and killing by human PMNL with virulent strains, as defined by the rabbit intradermal test, suggests that these factors may mediate the pathogenicity of H. ducreyi.
Cure of Trypanosoma musculi infection by heat-labile activity in immune plasma
Authors: Wechsler D S , Kongshavn P A
Published: January 2020

Passive transfer of plasma from a mouse cured of parasitemia to a Trypanosoma musculi-infected host rapidly eliminates parasitemia; this curative activity, presumably mediated by an immunoglobulin, is sensitive to heat treatment (56 degrees C, 30 min). In addition, pretreatment with immune plasma, even after heat treatment, prevents the development of a patent parasitemia in a naive host (protective activity).
Ceruloplasmin and regulation of transferrin iron during Neisseria meningitidis infection in mice
Authors: Letendre E D , Holbein B E
Published: January 2020

The role of ceruloplasmin (ferroxidase I; EC 1.16.3.1) in iron metabolism during experimental Neisseria meningitidis infection was investigated. Plasma ceruloplasmin activity was found to increase greatly in mice during the convalescence phase of iron-controlled infection and after a plasma hypoferremia had occurred. Ceruloplasmin activity-deficient animals became hypoferremic as a result of an impaired release of iron from the reticuloendothelial system as shown by impaired return of reticuloendothelial system-processed heme iron in these mice. Hypoferremia in ceruloplasmin activity-deficient mice was associated with an increased resistance to N. meningitidis infection, an effect reversed readily by ceruloplasmin supplementation or iron addition. This evidence implicated ceruloplasmin activity as an important component in the regulation of the plasma transferrin iron pool and suggested that an important role of additional ceruloplasmin as an acute-phase protein might be related to the requirement of additional transferrin iron. This study also provided further evidence of the importance of transferrin iron and host hypoferremia in bacterial infection.
Enhancement by murabutide of the immune response to natural and synthetic hepatitis B surface antigens
Authors: Audibert F M , Przewlocki G , Leclerc C D , Jolivet M E , Gras-Masse H S , Tartar A L , Chedid L A
Published: January 2020

Adjuvant-active murabutide (N-acetylmuramyl-L-alanyl-D-glutamine-alpha-n-butyl ester), devoid of the side effects of muramyl dipeptide (N-acetylmuramyl-L-alanyl-D-isoglutamine), was administered in saline with natural and synthetic hepatitis B surface antigens (HBsAgs). This derivative enhanced the antibody responses against natural HBsAg. The persistence of high antibody titers was the same in the murabutide-treated group as in the alum-treated group. A synergistic enhancement of the antibody was obtained when both adjuvants were administered together. Cell-mediated immunity to HBsAg, tested by the proliferative response of lymph node cells to the antigen, was also shown to be induced in mice treated with alum-associated murabutide. When administered with natural HBsAg, murabutide produced titers of total antibodies as high as did alum but lower titers of specific immunoglobulin E. High levels of antipeptide antibodies were obtained when a synthetic fragment [HBsAg(99-121)] conjugated to a toxoid carrier was administered with murabutide in saline.
Oligosaccharide structures mediating agglutination of sheep erythrocytes by Staphylococcus saprophyticus
Authors: Gunnarsson A , Mårdh P A , Lundblad A , Svensson S
Published: January 2020

Agglutination of sheep erythrocytes by Staphylococcus saprophyticus was used as a model system for adherence studies. Glycolipids were isolated from sheep erythrocyte membranes, and oligosaccharides were prepared by trifluoroacetolysis. The oligosaccharides were characterized by sugar analyses, methylation analyses, gas-liquid chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. We showed that oligosaccharides containing terminal beta-D-galactose-p-(1-4)-beta-D-2-acetamido-2-deoxyglucose-p-(1- were good inhibitors of the hemagglutination of sheep erythrocytes by S. saprophyticus.
Influence of fine structure of lipid A on Limulus amebocyte lysate clotting and toxic activities
Authors: Takayama K , Qureshi N , Raetz C R , Ribi E , Peterson J , Cantrell J L , Pearson F C , Wiggins J , Johnson A G
Published: January 2020

We examined the relationship between the fine structure of lipid A and the toxicity of endotoxin or lipopolysaccharides as measured by the Limulus amebocyte lysate (LAL), rabbit pyrogenicity, chicken embryo lethal dose, and dermal Shwartzman reaction tests. Lipid A and lipid A-like compounds obtained from deep-rough mutants of Salmonella spp. and Escherichia coli had a wide range of structural variations. These compounds included native lipopolysaccharides, diphosphoryl and monophosphoryl lipid A's, and lipid X (a monosaccharide). The LAL test was positive for all lipids tested with lysates from Travenol Laboratories and from Associates of Cape Cod (2.9 X 10(3) to 2.6 X 10(7) endotoxin units per mg), except for O-deacylated and dephosphorylated lipid X, which were negative. The Mallinckrodt lysate gave negative tests for lipid X. In the rabbit pyrogenicity and chicken embryo lethal dose tests, only native lipopolysaccharide and diphosphoryl lipid A's were judged toxic. The Shwartzman reaction was positive for a specific purified diphosphoryl lipid A (thin-layer chromatography-3 fraction) but negative for the purified monophosphoryl lipid A (also a thin-layer chromatography-3 fraction). These results show that the LAL test is not a valid measure of all parameters of toxicity of a lipid A or lipid A-like compound and can yield false-positive results. However, these findings are not in conflict with the widespread use of the LAL assay for pyrogens in the pharmaceutical industry since a good correlation exists between LAL results and pyrogenicity when undegraded endotoxin is evaluated in parallel assays.
Transposon-mediated mutagenesis and recombination in Vibrio cholerae
Authors: Newland J W , Green B A , Holmes R K
Published: January 2020

An efficient method for introducing transposons into the Vibrio cholerae chromosome or the P plasmid was developed by using F'tslac+ plasmids from Escherichia coli as suicide delivery vehicles. Hybrid P::Tn1, Tn5 and P::Tn1, Tn10 plasmids containing Tn5 or Tn10 in either of the two possible orientations were constructed. During conjugation, these hybrid plasmids mediated oriented transfer of markers from the sites of insertion of homologous transposons in the donor chromosome. The collection of donor strains described here permits oriented mobilization of all parts of the V. cholerae chromosome.
Kinetic analysis of microbe opsonification based on stimulated polymorphonuclear leukocyte oxygenation activity
Authors: Allen R C , Lieberman M M
Published: January 2020

With Pseudomonas aeruginosa as the target microbes and polymorphonuclear leukocytes (PMNL) as effector phagocytes, the microbe-specific, immunoglobulin G (IgG)-dependent opsonic capacities of preimmune and immune sera were measured as the rate of stimulated PMNL dioxygenation of luminol yielding chemiluminescence (CL). When the reactants other than opsonin are present in concentrations that are not rate limiting, the information-effector relationship linking specific opsonin concentration to effector PMNL stimulation is described by the rate equation: L' = k'[IgG]i, where L' is the peak CL velocity (photons per minute), k' is the proportionality constant, [IgG] is the concentration of specific opsonin, and the exponent i is the order of the reaction with respect to opsonin. Since the specific opsonins were polyclonal IgG of unknown absolute serum concentration, the reciprocal rate expression, L' = k'D-i, was employed for data presentation; D is the serum dilution (final volume/initial serum volume), and the sign of i is changed to negative. The relationships of integral, first-derivative, and second-derivative expressions of the CL response to opsonin concentration are illustrated with experimentally obtained data. Based on peak CL velocity or peak CL acceleration measurements taken over different time intervals of testing, the estimated order with respect to opsonin is highest, and probably most accurate, using the shortest test interval allowing reasonably good precision of measurement. As an alternative temporal approach, microbe opsonification kinetics are analyzed based on nodal time (Tn) measurements. The Tn is the time point separating the acceleration and deceleration phases of the PMNL oxygenation response to stimulation and as such satisfies the criterion of a selected condition of PMNL activation.
Demonstration of interleukin 1 activity in apparently homogeneous specimens of the pI 5 form of rabbit endogenous pyrogen
Authors: Hanson D F , Murphy P A
Published: January 2020

Rabbit mononuclear cells from oil-induced peritoneal exudates were purified by centrifugation on Percoll gradients, suspended in tissue culture medium, and stimulated with opsonized Staphylococcus epidermidis. The supernatants from these macrophages caused fever when injected intravenously into rabbits (endogenous pyrogen [EP] activity). The EP activity was contained in two protein fractions, with pIs of 7.3 and ca. 5.0. The same fractions caused mouse thymocytes to incorporate tritiated thymidine when incubated in vitro with small quantities of phytohemagglutinin (interleukin 1 [IL-1] activity). The pI 5.0 form of EP was purified to apparent homogeneity by sequential use of ammonium sulfate precipitation, gel filtration, ion-exchange chromatography, hydrophobic chromatography, and high-resolution isoelectric focusing. EP and IL-1 activities were not separable by any of these procedures. Active fractions from isoelectric focusing were analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Only one band was visible as judged by a silver staining method, and IL-1 activity could be recovered by renaturing eluates from the same region of sodium dodecyl sulfate gels run in parallel. An estimate of specific activity was made by comparing the intensity of stained bands of EP with the intensity of bands containing known quantities of lysozyme or RNase. By this criterion, the specific activity of purified pI 5 EP was between 17,000 and 58,000 degrees C U/mg of protein, and the specific activity in terms of IL-1 was between 59 million and 360 million U per mg of protein. These observations suggest that both EP and IL-1 activities can be expressed by a single molecular species. The implications of this coincidence are discussed. It was also shown that highly purified pI 5 EP obtained from macrophages stimulated in the presence of 14C-labeled amino acids contained significant 14C radioactivity. This suggests that the pI 5.0 EP, like the pI 7.3 form, was synthesized de novo from amino acid precursors.
Purification and characterization of an immunoglobulin A1 protease from Bacteroides melaninogenicus
Authors: Mortensen S B , Kilian M
Published: January 2020

Attention has recently been focused on bacterial proteases with the capacity to cleave immunoglobulin A (IgA proteases) as possible pathogenic factors in bacterial meningitis, gonorrhoea, and destructive periodontal disease. Here, we describe a method for the rapid purification of a specific IgA1 protease from Bacteroides melaninogenicus. The IgA1 protease was purified 6,172-fold with a yield of 9% by ammonium sulfate precipitation, DEAE-ion exchange chromatography, and separation on a preparative TSK-G 3000SWG high-pressure gel permeation chromatography column. The enzyme was specific for human IgA1 and cleaved a prolyl-seryl peptide bond in the hinge region of the alpha 1 chain between residues 223 and 224. The molecular weight of the enzyme was 62,000, the isoelectric point was 5.0, and the Km was 3.4 X 10(-6). The enzyme was active over a broad pH range and had maximal activity at pH 5.0. B. melaninogenicus IgA1 protease was classified as a thiol protease on the basis of its inhibition by traditional protease inhibitors and the fact that it was active only under reducing conditions.
Response of syphilitic rabbits to reinfection with homologous and heterologous Treponema pallidum strains
Authors: Strugnell R A , Faine S , Graves S
Published: January 2020

Rabbits infected intradermally with 10(3) Treponema pallidum (Melbourne 1) cells were examined for their susceptibility to reinfection with 10(2) T. pallidum cells (homologous or heterologous strains) at various intervals after the initial infection. At 2.5 weeks after infection, the rabbits were extremely sensitive to reinfection and developed syphilitic lesions significantly faster (i.e., shorter latent periods) than control rabbits that had not received the initial infection. This phenomenon may represent a state of immunosuppression or hypersensitivity in the infected rabbits. Whatever its etiology (at present unknown), it was a transient state since at 5 weeks after infection the rabbits were no longer different from control rabbits in their susceptibility to reinfection. They showed neither immunity (i.e., longer latent periods) nor immunosuppression or hypersensitivity (shorter latent periods) upon reinfection. At 6.5 weeks after infection, two of the three experimental rabbits were fully immune (no lesions upon reinfection), whereas the other rabbit exhibited immunosuppression or hypersensitivity upon reinfection. At 7.5 and 10 weeks after infection, all of the experimental rabbits were immune to reinfection. We conclude that syphilitic rabbits show a biphasic response to reinfection, consisting of an early phase of enhanced sensitivity to T. pallidum and a later phase of immunity to T. pallidum.
Monoclonal antibody analysis of specific antigenic similarities among pathogenic Treponema pallidum subspecies
Authors: Marchitto K S , Jones S A , Schell R F , Holmans P L , Norgard M V
Published: January 2020

Murine monoclonal antibodies directed against a 47,000-dalton immunodominant surface-exposed antigen of Treponema pallidum subsp. pallidum (Nichols) were isolated. These monoclonal antibodies cross-reacted with analogous 47,000-dalton antigens of two other virulent treponemes, T. pallidum subsp. pertenue and T. pallidum subsp. endemicum (Bosnia A), as determined by radioimmunoassay and immunoblot analyses. Immunoelectron microscopy confirmed that the 47,000-dalton antigen of T. pallidum subsp. pallidum was a surface-associated cellular component. Surface binding assays and immunoelectron microscopic studies also suggested that the analogous 47,000-dalton antigenic component of T. pallidum subsp. pertenue may not have been oriented toward the bacterial surface in the same way as the T. pallidum subsp. pallidum antigen or that the relevant antigenic determinant(s) may not have been exposed to the outer surface in the same way. The significance of this antigen relative to its apparent conservation among pathogenic treponemes and its possible diagnostic and vaccinogenic potentials are discussed.
Characterization of monoclonal antibodies to Streptococcus mutans antigenic determinants I/II, I, II, and III and their serotype specificities
Authors: Smith R , Lehner T , Beverley P C
Published: January 2020

Monoclonal antibodies (McAb) were developed to four protein components of Streptococcus mutans serotype c, some of which are significant in the protection against dental caries. The six McAb used in this investigation support the identities of streptococcal antigens (SA) I/II, I, II, and III. The specificities of these antigenic determinants were established both by direct binding and inhibition with the pure SA with a solid-phase radioassay. Whereas conventional antisera to S. mutans serotype c cross-react with serotypes c, e, and f (and g), McAb to serotype c-derived SA I/II react predominantly with serotype c and show some low-titer reactivity with serotype f. The slight cross-reactivity between S. mutants cells of serotypes c and f could be further differentiated by absorption of any of the three McAb to SA I/II with cells of serotype c. Parallel studies of McAb with cells of S. mutans and their ammonium sulfate-precipitated culture supernatants suggest that some SA determinants are retained predominantly on the cell surface, but others are readily shed into the culture medium, so that they are detected both on the cell surface and culture medium. Unlike polyclonal antibodies, McAb are capable of discriminating single antigenic determinants and can be applied to the study of shedding of antigens from microorganisms into the environment, such as the gut or gingival sulcus.
Cytotoxicity of leukocytes from normal and Shigella-susceptible (opium-treated) guinea pigs against virulent Shigella sonnei
Authors: Morgan D R , DuPont H L , Wood L V , Kohl S
Published: January 2020

Intraepithelial lymphocytes were collected from the ileum of adult Hartley strain guinea pigs and used as effector cells in a 60-min bactericidal assay with virulent Shigella sonnei as target cells. Natural killer cytotoxicity (NKC) and antibody-dependent cellular cytotoxicity (ADCC) were measured and correlated with the resistance of the animals to infection by S. sonnei. Normal guinea pig intraepithelial lymphocytes exhibited mean NKC and ADCC values of 22.8 +/- 5.0 and 34.1 +/- 13.6, respectively. These animals were resistant to oral challenge with virulent S. sonnei. Intraepithelial lymphocytes from guinea pigs which were fasted for 4 days demonstrated NKC and ADCC values similar to those of normal animals (31.0 +/- 8.1 and 41.7 +/- 6.7, respectively). These animals also were resistant to oral challenge. Intraepithelial lymphocytes from guinea pigs which were given 1 ml of deodorized tincture of opium 2 h before cell collection demonstrated deficient NKC (4.7 +/- 4.2) and ADCC (5.3 +/- 4.9) values but remained resistant to infection by S. sonnei. When guinea pigs were fasted for 4 days and given opium, deficient NKC (2.0 +/- 2.0) and ADCC (1.3 +/- 1.3) values were demonstrated; this group of animals was susceptible to infection by S. sonnei (P less than 0.04). These experiments demonstrated that opium treatment depresses one form of gut immunity. When combined with starvation, opium treatment may increase susceptibility to infection by shigellae by modulation of immunity in addition to the effects on gut motility and bacterial flora.
Monoclonal antibodies to serotype 2 and serotype 15 outer membrane proteins of Neisseria meningitidis and their use in serotyping
Authors: Zollinger W D , Moran E E , Connelly H , Mandrell R E , Brandt B
Published: January 2020

A series of murine monoclonal antibodies to serotype 2 and serotype 15 strains of Neisseria meningitidis were produced which were specific for outer membrane proteins of classes 1, 2, 3, and 5. A panel of eight monoclonal antibodies that exhibited a high degree of serotype specificity when reacted with prototype strains of known serotype were selected for study. Each of the corresponding epitopes was localized on a specific outer membrane protein by means of immunoprecipitation, electroblotting, or both. The serotype 2a-, 2b-, and 2c-specific antibodies bound to the class 2 protein, the serotype 15-specific antibody bound to the class 3 protein, two antibodies (3-1-P1.2 and 3-1-P1.16) bound to class 1 proteins, and two antibodies (1-1-P5.1 and 3-1-P5.2) bound to class 5 proteins. Six of these monoclonal antibodies were used in a spot-blot procedure to survey 122 case isolates (groups B, C, Y, and W135) and 363 carrier isolates (all serogroups) for the presence of the 2a, 2b, 2c, 15, P1.2, and P1.16 epitopes. A total of 66% of the case isolates and 30% of the carrier isolates reacted with one or more of the monoclonal antibodies. The use of monoclonal antibodies for serotyping of meningococci appears to be feasible and easy and appears to have significant advantages over the use of polyclonal typing sera.
Production of monoclonal antibodies that recognize specific and cross-reactive antigens of Bacteroides gingivalis
Authors: Hanazawa S , Saitoh K , Ohmori Y , Nishihara H , Fujiwara S , Kitano S
Published: January 2020

Four monoclonal antibodies directed against Bacteroides gingivalis were established by hybridoma technology. Their reactivity against B. gingivalis, Bacteroides intermedius, and Bacteroides melaninogenicus was detected by the enzyme-linked immunosorbent assay. Three monoclonal antibodies specifically reacted with B. gingivalis. One recognized antigens that were cross-reactive between B. gingivalis and B. intermedius. These monoclonal antibodies provide new tools for antigenic analysis of B. gingivalis.
Small virulence plasmid of Shigella dysenteriae 1 strain W30864 encodes a 41,000-dalton protein involved in formation of specific lipopolysaccharide side chains of serotype 1 isolates
Authors: Watanabe H , Nakamura A , Timmis K N
Published: January 2020

A 6-megadalton plasmid, pHW400, of Shigella dysenteriae 1 strain W30864 was previously found to specify one or more functions for O-antigen production and bacterial virulence (H. Watanabe and K. N. Timmis, Infect. Immun. 43:391-396, 1984). The region of pHW401, a Tn801-tagged derivative of pHW400, responsible for O-antigen production has been localized by gene cloning and Tn5 transposon mutagenesis. Analysis of lipopolysaccharide isolated from S. dysenteriae 1 bacteria carrying mutant plasmids revealed that the determinant for O-antigen synthesis, designated rfp, codes for a function involved in the formation of the O-polysaccharide side chain structure of lipopolysaccharide. Analysis of radioactively labeled proteins synthesized in minicells of Escherichia coli carrying mutant plasmids identified the product of the rfp gene as a 41,000-dalton protein. Southern hybridization with a DNA fragment carrying the rfp gene demonstrated that this determinant is present on 6-megadalton plasmids in other isolates of S. dysenteriae 1 but is not present at all in a variety of other Shigella, E. coli, and Salmonella typhimurium strains that were tested.
Interaction of Legionella micdadei with human monocytes
Authors: Weinbaum D L , Benner R R , Dowling J N , Alpern A , Pasculle A W , Donowitz G R
Published: January 2020

We have recently shown that Legionella micdadei is ingested, but not killed, by human neutrophils. Herein we investigate the role of human monocytes in defense against this organism. Serum and monocytes from normal donors having no detectable antibody to L. micdadei were used. Egg-passaged L. micdadei organisms multiplied inside these monocytes with a peak growth of 2 log units within 12 h. No growth occurred when monocytes were omitted or when sonicated monocytes were used. Electron microscopy 18 h after infection revealed these organisms to be intracellular in normal-appearing phagosomes. When the input multiplicity of L. micdadei was greater than 1 CFU per monocyte, no intracellular growth occurred. When egg-passaged Legionella pneumophila organisms were used, intracellular organisms were found in phagosomes studded with ribosomes at the same time period. Peak intracellular growth of L. pneumophilia occurred by 48 h. L. micdadei activated the complement system and was opsonized by C3. However the use of complement-depleted (heat-inactivated) serum as the opsonic source had no effect on the bacterium's ingestion or growth in the monocyte. Thus, L. micdadei multiples in human monocytes. This entry and growth is independent of antibody or complement. The intracellular locations of L. micdadei and L. pneumophila differ, suggesting different mechanisms for the survival of these two organisms in the monocyte.
Ultrastructural localization of specific gonococcal macromolecules with antibody-gold sphere immunological probes
Authors: Robinson E N , McGee Z A , Kaplan J , Hammond M E , Larson J K , Buchanan T M , Schoolnik G K
Published: January 2020

In an effort to determine the ultrastructural location of specific macromolecules on the surface of intact microorganisms and in experimentally infected tissues, a new method of rapidly conjugating antibodies to gold spheres via a staphylococcal protein A intermediary has been developed. This new technique provides the excellent density of marking and versatility of sphere size provided by existing gold methods, but decreases preparation time, decreases the chance of bacterial contamination of antibody reagents, and increases specificity of marking. Staphylococcal protein A-coated gold spheres were conjugated with antibodies from rabbits immunized with purified gonococcal pili. The resulting gold-antibody conjugates allowed demonstration of antibody binding to pilus structures of the same gonococcal strain whose pili were used to raise the antibody and demonstration of the lack of antibody recognition of pilus structures on two other gonococcal strains. The failure of gold spheres to attach to isogenic nonpiliated clones of the homologous gonococcus indicated the absence of pilus antigens on the surface of these organisms. The use of a double label--small gold spheres conjugated to anti-pilus antibody and larger gold spheres conjugated to anti-protein I antibody--allowed the simultaneous localization of two gonococcal antigens.
Fimbria-like hemagglutinin of Escherichia coli O75 strains
Authors: Väisänen-Rhen V
Published: January 2020

Fifteen strains of Escherichia coli O75 from human feces and patients with urinary tract infections were analyzed for their hemagglutinative properties, production of hemolysin and colicin, and plasmid contents. Fourteen strains produced type-1 fimbriae in broth culture. Nine of the strains agglutinated human P1 and p erythrocytes, i.e., possessed an X adhesin (X hemagglutinin). All but one of the X+ strains agglutinated human but not sheep or rabbit erythrocytes. Of the 15 strains, 4 had P fimbriae; one strain had both X hemagglutinin and P fimbriae. A coli-like structure was found by electron microscopy on the surface of the X+ strains. This structure was purified from two strains and characterized chemically and serologically. It was a protein consisting of subunits with an apparent molecular weight of 16,000. The amounts of hydrophobic amino acids in proteins purified from strains IH11033 and IH11128 were 35 and 39%, respectively. The amino acid content of the proteins was quite similar; only glutamine-glutamate and tyrosine contents were different. The radiolabeled protein bound to human erythrocytes, but it differed morphologically from typical E. coli fimbriae. Several methods showed the hemagglutinin, termed O75-X, to be serologically related in all the O75 X+ strains. The eight X+ O75:K5:H- strains had type-1 fimbriae and an identical outer membrane protein pattern, lacked P fimbriae and hemolytic activity, and are proposed to represent a clonal group.
Effect of thioglycolate on phagocytic and microbicidal activities of peritoneal macrophages
Authors: Leijh P C , van Zwet T L , ter Kuile M N , van Furth R
Published: January 2020

Brewer thioglycolate-elicited mouse peritoneal macrophages were as active as resident peritoneal macrophages in the phagocytosis of opsonized Staphylococcus epidermidis but were unable to kill ingested microorganisms. This decreased functional activity was restricted to Brewer thioglycolate-elicited macrophages, since peritoneal macrophages elicited with NIH thioglycolate, alone or supplemented with agar and methylene blue, were as active as resident peritoneal macrophages. No effect of agar on the functional activities of macrophages was observed. A defective intracellular killing by peritoneal macrophages due to Brewer thioglycolate was seen only after an intraperitoneal injection with thioglycolate, not after in vitro incubation of resident macrophages with thioglycolate. The results of this study show that, depending on the kind of thioglycolate used, the functional characteristics of elicited macrophages may alter. However, none of the forms of thioglycolate investigated induced the recruitment of activated macrophages.
Purification and characterization of a cloned protease-resistant Treponema pallidum-specific antigen
Authors: Fehniger T E , Walfield A M , Cunningham T M , Radolf J D , Miller J N , Lovett M A
Published: January 2020

A cloned Treponema pallidum antigen, designated 4D, was purified from Escherichia coli predominantly as a 190-kilodalton (kd) polypeptide, although higher oligomeric forms exist. Extensive proteolysis of 4D created a limit digestion product of 90 kd which retained antigenicity with sera from patients with primary, secondary, early latent, late latent, and tertiary syphilis. A molecule indistinguishable from 90-kd 4D in size, isoelectric point, and antigenicity was isolated from T. pallidum after proteolysis. The 190- and 90-kd forms of 4D were stable at 68 degrees C but converted to 19- and 14-kd species, respectively, after boiling in sodium dodecyl sulfate. The low-molecular-weight species did not react with syphilitic sera. Rabbits immunized with the purified 4D antigen developed antibodies which immobilized virulent T. pallidum in a complement-dependent assay system, suggesting that the antigen has a native surface location.
Mycoplasma pneumoniae-induced hydrocephalus in hamsters
Authors: Kohn D F , Chinookoswong N , Wang J
Published: January 2020

Hydrocephalus was induced in neonatal hamsters after intracerebral inoculation of Mycoplasma pneumoniae. Examination of the ependyma from affected animals by electron microscopy did not reveal mycoplasma. However, in an ependymal organ culture system, M. pneumoniae cytadsorbed to ependymal cells.
Single locus in BXH-2 mice responsible for inability to control early proliferation of Trypanosoma cruzi
Authors: Trischmann T M
Published: January 2020

The inability of the BXH-2 recombinant inbred strain to limit proliferation of Trypanosoma cruzi during the first 2 weeks after infection was found to be controlled by a single locus difference between the BXH-2 strain and each of its parental strains: C3H/HeJ and C57BL/6J. In both cases, the inability to limit parasite proliferation acted like a recessive trait. The loci in the C3H and C57BL/6 strains appear to be identical since all F2 mice derived from these strains displayed the early control trait. A mutation is thus likely to have occurred in the derivation of the BXH-2 strain. The provisional designation Crz has been given to the locus in the BXH-2 strain that is responsible for its failure to control early proliferation of T. cruzi. The Crz locus is distinct from the lpr gene which has also been associated with increased levels of parasitemia early in the course of the infection.
Adherence of Bordetella bronchiseptica to hamster lung fibroblasts
Authors: Plotkin B J , Bemis D A
Published: January 2020

The adherence of Bordetella bronchiseptica smooth-, intermediate-, and rough-phase isolates to hamster lung fibroblasts (HLF) (Don line) was characterized by competitive inhibition studies and enzyme and chemical treatments of both the bacteria and the HLF. The adherence of the rough- and intermediate-phase isolates (n = 13) was altered by coincubation of the bacteria and HLF with cationic chelators, including EGTA and citrate. EGTA inhibition of the adherence of the rough- and intermediate-phase isolates could be overcome by the addition of Ca2+, Mn2+, Cd2+, or Sr2+ to the reaction mixture. In addition, citrate released bound bacteria from the HLF. Although the adherence of the smooth-phase isolates (n = 4) was unaltered by cationic chelators, binding was inhibited by N-acetylated amino sugars, with N-acetylglucosamine inhibiting 98% of the adherence of the smooth-phase isolates. Homogenization, protease K, and heat treatment (60 min, 60 degrees C) of the bacteria also resulted in a loss of adherence. It was concluded that B. bronchiseptica can adhere to HLF by at least two mechanisms and that the ligand responsible appears to be a proteinacious, heat labile cell surface component.
Cosmid cloning of Rickettsia prowazekii antigens in Escherichia coli K-12
Authors: Krause D C , Winkler H H , Wood D O
Published: January 2020

Rickettsia prowazekii DNA was partially digested with Sau3A or HindIII, ligated with the cosmid vector pHC79, packaged in vitro, and transduced into Escherichia coli HB101. Cosmid cloning of Sau3A-digested rickettsial DNA yielded 1,288 ampicillin-resistant colonies; 798 cosmid clones resulted with HindIII-digested rickettsial DNA. Chimeric cosmid DNA was extracted from the latter gene bank, digested to completion with HindIII, and compared by agarose gel electrophoresis with a HindIII digest of rickettsial genomic DNA. The two digestion profiles were quite similar in their overall banding patterns, indicating that the clone bank was significantly representative of the rickettsial genome. When both clone banks were screened for expression of rickettsial antigens by enzyme-linked immunosorbent assay with goat anti-R. prowazekii serum, ca. 20% of the clones reacted positively. Two clones were randomly selected for more detailed analysis. Each contained a large chimeric plasmid (40.2 and 38.1 kilobases) which apparently yielded smaller deletion derivatives (13.6 and 12.6 kilobases) when transformed into an E. coli minicell strain. Each recombinant plasmid directed the synthesis of new protein species not observed in control minicells. One of the clones produced a 51,000-dalton protein in minicells, which comigrated with a protein reactive with anti-R. prowazekii serum. This protein was not present in negative controls. When antibodies to this protein were incubated with a Western blot of rickettsial total protein, they bound to a 52,000-dalton polypeptide. Hence, the cloned rickettsial gene product in E. coli corresponds to a protein of similar size in R. prowazekii. This study demonstrates the feasibility of cosmid cloning of rickettsial antigens in E. coli.
Comparison of Bacteroides zoogleoformans strains isolated from soft tissue infections in cats with strains from periodontal disease in humans
Authors: Love D N , Johnson J L , Jones R F , Bailey M
Published: January 2020

A total of 11 strains of Bacteroides zoogleoformans were isolated from 11 of 106 different cat subcutaneous "fight wound" abscesses and were among a total of 143 Bacteroides species isolated from these samples. They constituted 3.4% (11 of 325) of all anaerobic isolates. The cat strains and strains of B. zoogleoformans isolated from humans with periodontal disease were similar phenotypically as determined by biochemical reactions, polyacrylamide gel electrophoresis patterns of soluble proteins, and guanine plus cytosine ratios of DNA. Eight cat strains and five human strains tested had 45 to 54% DNA homology with the type strain of B. zoogleoformans. The eight cat strains and five human strains (excluding the type strain) were related by DNA homology at 70 to 77%. There was 85 to 90% intragroup DNA homology among the cat strains and 86 to 89% intragroup homology among the five human strains. The implications for epidemiology and human and animal ecology are discussed.
Effect of local and parenteral immunization on implantation of Actinomyces viscosus T6 in rats
Authors: Olsson J , Hsu S D , Kingman A , Cole M F
Published: January 2020

Groups of rats immunized in the vicinity of the major salivary glands or immunized intraperitoneally with Actinomyces viscosus T6 and their sham-immunized controls were infected with the homologous bacterium. Significantly higher levels of salivary and serum antibody were induced by intraperitoneal than by salivary gland immunization. There were also significant inverse correlations between the levels of salivary and serum antibody and the levels of implantation of A. viscosus T6. The level of implantation of A. viscosus T6 was significantly lower in the immunized animals than in the controls. However, antibody had limited capacity to inhibit the establishment of this bacterium.
Effects of anthrax toxin components on human neutrophils
Authors: O'Brien J , Friedlander A , Dreier T , Ezzell J , Leppla S
Published: January 2020

The virulence of Bacillus anthracis has been attributed to a tripartite toxin composed of three proteins designated protective antigen, lethal factor, and edema factor. The effects of the toxin components on phagocytosis and chemiluminescence of human polymorphonuclear neutrophils were studied in vitro. Initially, it was determined that the avirulent Sterne strain of B. anthracis (radiation killed) required opsonization with either serum complement or antibodies against the Sterne cell wall to be phagocytized. Phagocytosis of the opsonized Sterne cells was not affected by the individual anthrax toxin components. However, a combination of protective antigen and edema factor inhibited Sterne cell phagocytosis and blocked both particulate and phorbol myristate acetate-induced polymorphonuclear neutrophil chemiluminescence. These polymorphonuclear neutrophil effects were reversible upon removal of the toxin components. The protective antigen-edema factor combination also increased intracellular cyclic AMP levels. These studies suggest that two of the protein components of anthrax toxin, edema factor and protective antigen, increase host susceptibility to infection by suppressing polymorphonuclear neutrophil function and impairing host resistance.
Entamoeba histolytica trophozoites in the lumen and mucus blanket of rat colons studied in vivo
Authors: Leitch G J , Dickey A D , Udezulu I A , Bailey G B
Published: January 2020

Trophozoites of Entamoeba histolytica HM-1 were cultivated axenically in TYI-S medium. The amoebae were then transferred into this medium lacking serum (TYI) and inoculated into in vivo colon loops of adult Sprague-Dawley rats. The trophozoites were rapidly absorbed by the mucus, and few were found free in the luminal fluid by 1 h. By 4 h, the amoebae began to reappear in the lumen, aggregated in sloughed mucus blanket fragments. The colon was examined histologically and by scanning electron microscopy. There was no evidence of invasion or even brush-border attachment by the trophozoites within 4 h. In TYI, trophozoite motility was low. Exposure to the colonic lumen environment for 5 min in this medium significantly increased motility. However, as the trophozoites became absorbed to mucus fragments, their observed motility virtually ceased despite some morphological evidence of pseudopod extension. Erythrophagocytosis was not significantly affected by either exposing trophozoites to TYI washings of the colonic lumen, or by the more complete medium, TYI-S, in which the amoebae were significantly more motile. Two major mucus glycoprotein oligosaccharide end-group sugars, L-fucose and N-acetyl-neuraminic acid, were tested for their effects on trophozoite motility in both TYI and TYI-S. L-Fucose reduced motility; the sialic acid increased motility. It is concluded that the intestinal lumen contains several compartments, including the luminal fluid and the mucus blanket, and that Entamoeba trophozoites exist in a highly motile state in the former and a low motility state in the latter. The mucus blanket provided a significant barrier to trophozoite access to intestinal epithelium target tissue.