bluuebunny/crossref_metadata_2025 huggingface dataset:
Serological specificity of phenolic glycolipid I from Mycobacterium leprae and use in serodiagnosis of leprosy
Authors: Cho S N , Yanagihara D L , Hunter S W , Gelber R H , Brennan P J
Published: January 2020

The serological activities of the specific phenolic glycolipid I from Mycobacterium leprae, its dissected parts, and related glycolipids from other mycobacteria were examined by enzyme-linked immunosorbent assay against hyperimmune anti-M. leprae rabbit antiserum and sera from patients with leprosy and other mycobacterial diseases. High anti-phenolic glycolipid I immunoglobulin M antibodies were found in 23 of 24 (96%) of lepromatous leprosy patients on short term chemotherapy and in 8 of 13 tuberculoid leprosy patients (62%). Sera from patients with tuberculosis or atypical mycobacterial infections were devoid of anti-phenolic glycolipid I activity. The structurally related phenolic glycolipids from Mycobacterium kansasii and Mycobacterium bovis and the aglycone segments of the M. leprae product showed no significant activity. Thus, the trisaccharide determinant of phenolic glycolipid I is specific in its structure, serological activity, and, to a lesser extent, the antibody class it evokes.
Virulence of different Pseudomonas species in a burned mouse model: tissue colonization by Pseudomonas cepacia
Authors: Stover G B , Drake D R , Montie T C
Published: January 2020

The virulence of Pseudomonas aeruginosa and other pseudomonads was examined in a burned mouse model. P. aeruginosa M-2 was highly virulent causing 100% mortality by 38 h with an injection of 10(2) CFU by either a subcutaneous or intraperitoneal route. Subcutaneous injection of 10(2) CFU revealed rapid multiplication of the bacteria at the burn wound with 10(8) CFU/g detectable in the burned skin by 28 h postinjection, 10(5) CFU/g of liver, and 10(3) CFU/ml of blood. Non-P. aeruginosa clinical isolates were markedly less virulent; an injection of greater than or equal to 10(7) CFU caused less than or equal to 60% lethality. P. cepacia SMH colonized the burned skin of thermally injured mice, persisting at levels of 10(7) to 10(8) CFU/g of burned skin after an initial injection of 10(5) CFU. P. cepacia persisted in the burn wound for at least 3 weeks. No organ invasion was detectable throughout this period. Studies with an additional clinical isolate of P. cepacia yielded similar results. An injection of a 10(2) CFU dose revealed that the level of persistence is dose dependent. Results suggest that the tenacious persistence of P. cepacia in the burn wound may provide a model for the study of persistent colonization and infection in a compromised host.
Natural macrophage cytotoxicity against Trichomonas vaginalis is mediated by soluble lytic factors
Authors: Martinotti M G , Cofano F , Martinetto P , Landolfo S
Published: January 2020

Mechanisms of lysis of the extracellular protozoan Trichomonas vaginalis by uninduced resident macrophages were analyzed. Supernatants obtained by culturing such macrophages with T. vaginalis were cytotoxic for the protozoa in a dose-dependent manner. Supernatants from macrophages cultured alone were cytotoxic at lower levels, whereas those obtained from T. vaginalis alone and from macrophages cultured with unrelated cells (B77) were not cytotoxic. Cytotoxic activity appeared after 4 h of contact between effectors and target cells and reached a plateau at 18 to 24 h. Microtubule disrupting agents (colchicine and vinblastine) enhanced protozoan lysis, whereas cytochalasin B, an inhibitor of microfilaments, completely blocked T. vaginalis lysis. Treatment of macrophages with protein synthesis inhibitors (cycloheximide and puromycin) impaired effector cytotoxicity. Lytic activity remained after dialysis of supernatants, treatment with 10% bovine fetal serum, and treatment at 56 degrees C for 1 h, but it was completely prevented by treatment at 90 degrees C for 10 min. In conclusion, our data show that natural cytotoxicity against T. vaginalis is performed by normal resident macrophages through the release of at least two heterogeneous soluble factors.
Presence of oligoclonal immunoglobulin G bands and lack of matrix protein antibodies in cerebrospinal fluids and sera of ferrets with measles virus encephalitis
Authors: Thormar H , Mehta P D , Lin F H , Brown H R , Wisniewski H M
Published: January 2020

Young adult ferrets were immunized with measles vaccine and 5 to 6 weeks later inoculated intracerebrally with Vero cells persistently infected with cell-associated strain D.R. of measles virus isolated from a patient with subacute sclerosing panencephalitis. Of nine ferrets which survived the infection for 3 weeks or longer, five showed neurological signs. At the time of death they had widespread inflammation in their brains, and cell-associated virus was isolated from three ferrets sacrificed from 5 weeks to 7 months after inoculation. Four ferrets did not develop clinical signs, but two of these had mild inflammation in the brain 7 months and 2 1/2 years after inoculation, respectively. Cerebrospinal fluids drawn by cisternal puncture from infected ferrets at the time of sacrifice had neutralizing titers against measles virus similar to the titers found in sera, but antibody against the measles virus matrix protein was not detectable. Cerebrospinal fluid showed increased immunoglobulin G (IgG) and had distinct measles virus-specific oligoclonal IgG bands. The intensity of the bands correlated with the neutralizing titers of the fluids. These results confirm and extend earlier findings and indicate that persistent measles virus infection in ferrets is similar to human subacute sclerosing panencephalitis and can be used to study certain aspects of persistent brain infections leading to subacute encephalitis.
Natural variation of poliovirus neutralization epitopes
Authors: Crainic R , Couillin P , Blondel B , Cabau N , Boué A , Horodniceanu F
Published: January 2020

Poliovirus-neutralizing monoclonal antibodies were prepared against type 1, type 2, and type 3 wild laboratory (Mahoney, MEF1, and Saukett) and Sabin vaccine strains. Fifty-five poliovirus laboratory strains and field isolates were assayed by neutralization index test with a panel of homotypic monoclonal antibodies. A total of 27 monoclonal antibodies were used. Two categories of neutralization epitopes were found, i.e., cross-reacting (K), which is present on almost all strains of the same serotype, and strain-specific (V, variable), either wild (VW) or Sabin (VS). Several distinct neutralization epitopes were defined for each of the three poliovirus serotypes in almost every category. The study of antigenic variation of the Sabin type 1 vaccine virus during replication in human intestine showed that the VS neutralization epitope may be lost and even replaced by the VW epitopes of the parental Mahoney virus. A late isolate from a vaccine-fed infant recovered the complete neutralization epitope pattern of the Mahoney strain. Upon in vivo virus replication, a different kind of antigenic variation was also detected in which an epitope lost its function in virus neutralization but kept its antigenic conformation unaltered. Neutralization epitope analysis demonstrated that the presence of VS epitopes on a field isolate suggests the Sabin origin of the strain when the isolate displays the same epitope pattern as the original Sabin virus, or confirms it when the VS epitope(s) is mutually exclusive of VW epitopes. The lack of VS epitopes on a field isolate does not rule out its being of Sabin origin.
Adherence of streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa to fibronectin-coated and uncoated epithelial cells
Authors: Abraham S N , Beachey E H , Simpson W A
Published: January 2020

The relationship between the variability in the fibronectin (Fn) content on human buccal epithelial cells and the capacity of the cells to bind gram-positive (Streptococcus pyogenes) or gram-negative (Escherichia coli or Pseudomonas aeruginosa) bacteria was investigated. Adhesion experiments performed with mixtures of epithelial cells and mixed suspensions of either S. pyogenes and E. coli or S. pyogenes and P. aeruginosa exhibited three major populations of buccal cells: one of these was able to bind S. pyogenes (gram positive) but neither of the gram-negative bacteria; a second population was able to bind the gram-negative but not the gram-positive bacteria; and a third was able to bind various numbers of both types of organisms. Further adhesion experiments performed with a mixture of epithelial cells and a mixed suspension of S. pyrogens, E. coli, and fluoresceinconjugated methacrylate beads coated with immune immunoglobulin G directed against Fn revealed that the epithelial cells recognizing the gram-positive bacteria were rich in Fn, whereas those recognizing the gram-negative organisms were poor in Fn. Immunoelectron microscopy confirmed that cells of S. pyogenes bound to epithelial cells coated with Fn, whereas cells of E. coli bound to epithelial cells lacking Fn. These results suggest that Fn on the surfaces of epithelial cells may modulate the ecology of the human oropharyngeal cavity, especially with respect to the colonization of these surfaces by pathogenic gram-negative or gram-positive bacteria.
Production of a bacteriolysin by a hemolytic Escherichia coli strain
Authors: Jorgensen S E , Mussen H K , Mulcahy P F , Wu G K
Published: January 2020

Nonhemolytic Escherichia coli were outnumbered by hemolytic E. coli within 24 h after being inoculated in a mixed culture at an initial ratio of 200 nonhemolytic to 1 hemolytic organism. The hemolytic strain was found to produce a cell-free, filterable substance which causes lysis of nonhemolytic E. coli B when grown in liquid cultures but not when grown on agar plates. The bacteriolysin is inactivated by boiling, by freezing and thawing, and by incubation with trypsin. The inability to inhibit growth on an agar plate, dependence on cell concentration for its effect, lysis of the sensitive cells, and appearance of phage particles in the cell lysates suggest that this substance is not like colicins or microcins previously described. After lysis of E. coli B, bacteriophage particles were visible in transmission electron micrographs of material pelleted by ultracentrifugation. However, no bacteriophage were observed in pellets from the bacteriolysin-containing supernatants before lysis of E. coli B. Failure to find bacteriophage in these preparations, and the fact that some bacteriolysin activity remains in the supernatant solution after centrifugation at 150,000 X g for 6.5 h, indicate that the bacteriolysin is not itself a bacteriophage. Exposure of E. coli B to UV light and mitomycin C did not induce production of a temperate phage. The properties of this system, in which a cell-free substance produced by one strain of bacteria causes lysis of another strain, appear to differ from those of the various types of bacteriocins and bacteriophages described to date.
Monoclonal antibodies against colonization factor antigen I pili from enterotoxigenic Escherichia coli
Authors: Worobec E A , Shastry P , Smart W , Bradley R , Singh B , Paranchych W
Published: January 2020

Hybridomas secreting monoclonal antibodies directed against intact colonization factor antigen I pili have been produced by the fusion of spleen cells from immunized BALB/c mice with NS1/SP2 myeloma cells. The four monoclones with the highest antibody titer, as detected by enzyme-linked immunosorbant assay (ELISA), were chosen for antibody amplification by production of mouse ascitic fluid. These four were examined for antibody specificity by ELISA and immunoblot assays, using six different pilus types. Three of the four monoclonal isolates were specific for only colonization factor antigen I pili in both assays, whereas the remaining isolate showed a distinct cross-reactivity with K99 pili in the ELISA assay but not in immunoblot analysis. These results indicate that this monoclone may be recognizing a common structural element between the two adhesive pilus types.
Association between human serum-induced crisis forms in cultured Plasmodium falciparum and clinical immunity to malaria in Sudan
Authors: Jensen J B , Boland M T , Allan J S , Carlin J M , Vande Waa J A , Divo A A , Akood M A
Published: January 2020

Clinical histories with regard to falciparum malaria were collected from adults living in holo-, hyper-, and hypoendemic areas of Sudan and matched to serum samples which were assayed for antiparasitic activity in cultures of Plasmodium falciparum. The adult population of the endemic areas could be divided into three groups based on oral histories: those who never experience falciparum malaria; those with a childhood history of malaria, who experience only mild occasional malaria as adults; and those who suffer serious recurring malaria symptoms. In vitro parasite inhibition was greatest with sera from individuals with no clinical histories of malaria, and generally, more inhibition was noted in sera from holoendemic versus hyperendemic areas. Serum from hypoendemic urban Khartoum was not inhibitory. There was no relationship between serum indirect fluorescent antibody titers and parasite inhibition, but there was strong association between clinical immunity and intraerythrocytic parasite inhibition resulting in "crisis" forms. Purified immunoglobulin G was not strongly associated with crisis forms, which were consistently associated with fractions of immune serum remaining after immunoglobulin removal. Thus, it appears that clinical immunity to malaria in Sudan is based on nonantibody serum factors, possibly associated with cell-mediated immunity. Human leukocyte alpha-interferon had no inhibitory effects on cultured P. falciparum. Some umbilical cord sera were profoundly inhibitory, producing crisis forms, whereas others were not inhibitory, suggesting that factors that induce crisis forms may play a role in protecting neonates from falciparum malaria.
Alteration of rabbit alveolar and peritoneal macrophage function by herpes simplex virus
Authors: Plaeger-Marshall S , Wilson L A , Smith J W
Published: January 2020

Exposure of rabbit alveolar and peritoneal macrophages to infectious herpes simplex virus resulted in inhibition of antibody-dependent cellular cytotoxicity and either enhancement or inhibition of phagocytosis. At all times after exposure, virus was inhibitory to peritoneal macrophage phagocytosis. Alveolar macrophages showed enhanced phagocytic activity in the early stages of virus exposure and inhibition at later time points.
T lymphocyte subpopulations in congenital cytomegalovirus infection
Authors: Pass R F , Roper M A , August A M
Published: January 2020

T lymphocyte subpopulations in the peripheral blood of children with congenital cytomegalovirus infections and in controls were enumerated with monoclonal antibodies. Infants of less than 1 year of age with symptomatic infections showed significant increases in the proportion of suppressor cells and decreases in the ratio of helper to suppressor cells, whereas T lymphocyte populations in older symptomatic patients and asymptomatic infants and children did not differ from those in controls.
Possible role of enteric organisms in the pathogenesis of ankylosing spondylitis and other seronegative arthropathies
Authors: Prendergast J K , Sullivan J S , Geczy A , Upfold L I , Edmonds J P , Bashir H V , Reiss-Levy E
Published: January 2020

One-hundred eighty-five clinical isolates of Salmonella sp., Shigella sp., Escherichia coli, and Campylobacter sp. were tested for their ability to absorb the lymphocytotoxic activity of an antiserum (anti-Klebsiella sp. K43) directed against a specific HLA-B27-associated cell surface determinant on the lymphocytes of patients with ankylosing spondylitis (AS). Seven of these isolates (three Salmonella sp., two Shigella sp., one E. coli, and one Campylobacter sp.) were found to cross-react with the B27-positive cells of AS patients (B27+ AS+); an E. coli organism isolated from the rectal swab of an HLA-B27-negative clinically normal individual also cross-reacted with B27+ AS+ cells. These cross-reactive enteric organisms elaborate a factor (modifying factor) which specifically modifies the B27-positive lymphocytes of normal individuals; this factor is structurally and antigenically related to a functionally similar factor secreted by certain isolates of Klebsiella sp. These data suggest that certain enteric organisms share a common determinant which cross-reacts with B27+ AS+ cells. It is suggested that this cross-reactivity is somehow related to an early event in the pathogenesis of AS and possibly of other seronegative arthropathies.
Complexes of hepatitis B surface antigen and immunoglobulin M in the sera of patients with hepatitis B virus infection
Authors: Palla M , Rizzi R , Toti M , Almi P , Rizzetto M , Bonino F , Purcell R
Published: January 2020

Hepatitis B surface antigen (HBsAg) bound to immunoglobulin M (IgM) was detected in sera of HBsAg carriers by a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. Isopycnic banding and rate-zonal sedimentation have shown that the reaction is related to particulate forms of the HBsAg complexed with IgM. The binding of IgM possibly occurred because of a selective affinity of these molecules to the surface of HBsAg particles. HBsAg/IgM was found transiently in 24 of 25 (96%) patients with acute self-limited hepatitis B and persistently in 6 of 25 patients whose acute hepatitis B progressed to chronicity. It was also found in 20 of 39 (51%) chronic HBsAg carriers with inactive and asymptomatic infection. The HBsAg/IgM phenomenon is not dependent on replication of hepatitis B virions; its persistence in patients with acute hepatitis B may provide complementary evidence of transition of the infection to chronicity.
Antigenic heterogeneity of immunoglobulin A1 proteases from encapsulated and non-encapsulated Haemophilus influenzae
Authors: Kilian M , Thomsen B
Published: January 2020

Indirect evidence suggests that immunoglobulin A1 (IgA1) proteases may be factors in the pathogenesis of certain infectious diseases, including meningitis, gonorrhoea, and destructive periodontitis. Bacterial IgA1 proteases are therefore potential candidates as vaccines. In this study, IgA1 proteases from 166 clinical isolates and reference strains of Haemophilus influenzae and Haemophilus aegyptius were compared with regard to specific activity and pattern of enzyme inhibition by antisera raised against IgA1 protease from nine selected strains of H. influenzae. A total of 93% of H. influenzae strains and all H. aegyptius strains had detectable IgA1 protease activity. The majority of strains cleaved a prolyl-seryl or a prolyl-threonyl peptide bond in the alpha 1 hinge region, whereas occasional H. influenzae strains possessed two separate IgA1 proteases with these two specific activities. Of the 155 IgA1 protease-producing strains, all except 12 could be assigned to one of 14 IgA1 protease "inhibition types," each defined by a characteristic pattern of inhibition by the nine antisera. There was no correlation between IgA1 protease type and biotype of the strains. However, among 92 encapsulated H. influenzae strains, a close correlation between capsular serotype and IgA1 protease type was observed. With the exception of serotype f, strains of all capsular serotypes produced an exclusive antigenic type of IgA1 protease. All 38 strains of serotype b produced IgA1 protease of inhibition type 1, which was never demonstrated in non-encapsulated H. influenzae strains. These results facilitate the detection of an antibody response against specific IgA1 proteases and are of practical value for a possible future vaccine against H. influenzae serotype b infections.
Isolation and characterization of type III group B streptococcal mutants defective in biosynthesis of the type-specific antigen
Authors: Yeung M K , Mattingly S J
Published: January 2020

Four classes of mutants of type III group B streptococcus were isolated by serial subculture of the wild-type strain in the presence of type III-specific rabbit antiserum. Class I mutants no longer synthesized sialic acid but still elaborated the core antigen. Class II mutants maintained the ability to synthesize sialic acid but could not attach it to the core antigen. Class III mutants did not produce the core antigen but still synthesized intracellular sialic acid. Class IV mutants synthesized the complete antigen; however, only approximately 4% of the antigen synthesized was found associated with the cell wall peptidoglycan (in the wild-type strain greater than 85% of the antigen synthesized is covalently attached to the cell wall peptidoglycan), whereas greater than 90% of the antigen was secreted into the growth medium. Production of other components (CAMP factor, group B antigen, beta-hemolysin, neuraminidase) by these mutants appeared similar to those of the wild-type strain. Mouse lethality studies of these strains indicated that all four classes have greater than 3 log10-higher 50% lethal dose values than that of the wild-type strain. To understand the basis for this variation, the invasive ability of the wild-type strain and the sialic acid-deficient mutant strain M-10 (class I) was examined. Mice received 10(5) CFU of each organism; they were then sacrificed at various times postinoculation, and viable group B streptococci from different organs were enumerated. Mice were able to clear M-10 more efficiently, with greater than 80% of M-10 cells being phagocytized by macrophages within 1 h, whereas the wild-type strain was able to evade phagocytic killing and disseminate to other tissues. These data, therefore, strongly indicate that the sialic acid moiety greatly enhances the virulence of the type III antigen. In addition, the level of cell-associated type-specific antigen appears to contribute significantly to the pathogenicity of the organism.
Effect of parenteral immunization on the local immunoglobulin A response of the intestine to Shigella flexneri antigens
Authors: Keren D F , Scott P J , McDonald R A , Wiatrak M
Published: January 2020

Most traditional methods of immunization involve parenteral vaccines. Using a chronically isolated ileal loop model as the probe, we examined the effect of a primary parenteral immunization on the local immune response of the intestine. Secretions from isolated ileal loops of rabbits given a primary parenteral immunization with Shigella flexneri without adjuvant showed a small, but definite, specific immunoglobulin A (IgA) response locally, whereas a vigorous serum antigen-specific IgG response was elicited. Also, stronger antigen-specific IgG activity was detected in secretions of parenterally immunized animals than from animals given shigella only by oral immunization. No local IgA or IgG memory response could be elicited by prior parenteral priming with S. flexneri antigens. Lastly, no increase in the primary local IgA response was found in secretions from animals given an oral dosage regimen previously shown to prime for mucosal memory and then challenged with a single parenteral dose of the same antigen. These studies demonstrate that without adjuvant, parenteral doses of S. flexneri antigens elicit both specific serum and local immune responses, but they are not able to prime for a mucosal memory response upon subsequent mucosal challenge. The implications of these findings for programs that use parenteral vaccination to protect against mucosal diseases are discussed.
Ability of human cord blood lymphocytes to mediate antibody-dependent cellular cytotoxicity against influenza virus-infected cells
Authors: Hashimoto G , Wright P F , Karzon D T
Published: January 2020

Cord blood lymphocytes, monocytes, and neutrophils from newborns were shown to mediate antibody-dependent cellular cytotoxicity (ADCC) against influenza virus-infected cells. Antibody mediating ADCC was detectable in cord plasma, indicating that all components necessary for ADCC against influenza virus-infected cells are present in newborns. Among adult lymphocytes, two effector cell populations of influenza ADCC are recognized: non-T and T gamma cells. Each of these cell types expresses an antigen recognized by monoclonal HNK-1 antibody. The proportion of HNK-1 antigen-positive lymphocytes in cord blood was markedly lower than in adult blood; furthermore, ADCC was mediated by cord blood lymphocytes which were HNK-1 negative. By lymphocyte fractionation, the effector lymphocytes in cord blood were, as in adults, non-T and T gamma cells, suggesting that HNK-1 antigen is not expressed on these cell lineages in newborns.
Further studies of the role of noncapsular antibody in protection against experimental Haemophilus influenzae type b bacteremia
Authors: Shenep J L , Munson R S , Barenkamp S J , Granoff D M
Published: January 2020

Serum antibody against polyribosylribitol phosphate, the capsular antigen of Haemophilus influenzae type b, confers protection against experimental Haemophilus infection. Antibodies against noncapsular antigens are also protective, but the antigenic specificity of the protective antibodies remains unknown. Antilipopolysaccharide antibody was prepared by immunization of rabbits with boiled H. influenzae type b cells. Antilipopolysaccharide antibodies present in these sera did not protect against experimental Haemophilus bacteremia in infant rats. Antisera were also prepared by immunization of rabbits with live H. influenzae type b bacteria. After absorption of anticapsular and antilipopolysaccharide antibodies, these sera contained antibody to several outer membrane proteins which were accessible on the intact bacterial surface as detected by radioimmune precipitation. These absorbed sera prevented experimental Haemophilus bacteremia in infant rats. Thus, antibodies against noncapsular, non-lipopolysaccharide determinants, possibly against one or more outer membrane proteins, confer protection against experimental H. influenzae type b disease. In contrast, antibodies against lipopolysaccharide are ineffective.
Characterization of the gene encoding heat-stable toxin II and preliminary molecular epidemiological studies of enterotoxigenic Escherichia coli heat-stable toxin II producers
Authors: Lee C H , Moseley S L , Moon H W , Whipp S C , Gyles C L , So M
Published: January 2020

The gene encoding heat-stable toxin II (STII) was cloned into an Escherichia coli K-12 strain, and its nucleotide sequence was determined. The deduced amino acid sequence indicates that STII is synthesized within the cell as a 71-amino-acid protein and that neither the DNA nor amino acid sequence bears any similarity to that of heat-stable toxin I. A DNA fragment containing the STII gene was used to probe enterotoxigenic E. coli clinical isolates with various toxin phenotypes and was shown to be useful in detecting all STII and only STII producers.
Nucleotide sequence of the gene for heat-stable enterotoxin II of Escherichia coli
Authors: Picken R N , Mazaitis A J , Maas W K , Rey M , Heyneker H
Published: January 2020

Previously, the gene for heat-stable enterotoxin II (STII) has been mapped by transposon Tn5 insertion mutagenesis in the chimeric R-Ent plasmid pCG86 (Mazaitis, A. J., R. Maas, and W. K. Maas, J. Bacteriol. 145:97-105, 1981). DNA segments containing this gene were cloned from the wild-type and STII-insertion-mutant plasmid. The position of the Tn5 insertion was determined, and a 530-base-pair-long segment of the wild-type plasmid corresponding to the Tn5 insertion site was sequenced. An open reading frame for the STII gene was identified and is characterized by typical promoter and ribosome binding site sequences. The deduced STII structural gene codes for a protein 71 amino acids long, including a typical signal peptide of 23 amino acids and a mature protein of 48 amino acids. The size and overall structure of STII are similar to those of STI, but the amino acid compositions of the two heat-stable enterotoxins are completely different.
Effect of strain of Staphylococcus aureus on synergism with Candida albicans resulting in mouse mortality and morbidity
Authors: Carlson E
Published: January 2020

Nine Staphylococcus aureus strains isolated from patients with toxic shock syndrome (TSS), two strains from non-disease-associated sources, and four strains from disease (not TSS)-associated sources were characterized for the intraperitoneal dose necessary to kill 50% of exposed animals (LD50) and toxic shock toxin production and studied for synergistic effects on mouse mortality and morbidity when combined with a sublethal dose of Candida albicans and inoculated intraperitoneally. Representative toxic shock toxin-producing strains (free of other enterotoxins) exhibited the following unique set of characteristics when inoculated intraperitoneally into mice and compared with all other strains tested: (i) lowest virulence when inoculated alone into mice as determined by the LD50; (ii) greatest synergistic decrease in LD50 (up to 70,000-fold as compared to up to 200-fold for other strains) when combined with C. albicans and injected intraperitoneally; and (iii) induced a characteristic, dose-independent, temporal death pattern in dually injected animals. When sublethal dual doses were used, animals receiving disease (TSS and not TSS)-associated S. aureus in combination with C. albicans developed symptoms, but some differences in symptomatologies, depending on the strain, were observed. The symptoms included conjunctivitis; gastrointestinal, neurological, and circulatory abnormalities; rash followed by desquamation; and patchy baldness. Although overlap in symptoms between animal treatment groups was observed, certain symptoms (neurological sequeae and petechial hemorrhages) were observed only in animals inoculated with a specific S. aureus strain combined with C. albicans. Animals receiving sublethal dual doses, which included non-disease-associated S. aureus, did not develop symptoms. When Staphylococcus epidermidis was combined with C. albicans and inoculated into mice, no synergistic effects on morbidity or mortality were observed.
Electron microscopic localization of receptors for aggregated beta 2-microglobulin on the surface of beta-hemolytic streptococci
Authors: Wagner M , Wagner B , Kronvall G , Björck L
Published: January 2020

The presence and location of receptors for aggregated human beta 2-microglobulin (beta 2m) on the surface of group A, C, and G streptococci were studied by electron microscopic techniques. Ferritin-conjugated aggregates of human beta 2m were used in direct binding experiments. Ferritin-conjugated antibodies against beta 2m were employed in a two-step indirect binding assay where the streptococci were incubated with unlabeled beta 2m aggregates before the addition of antibodies. Similar results were obtained with these two methods. Among tested group C and G strains, some showed binding of beta 2m, whereas others were negative. In group A streptococci, beta 2m binding was localized to filamentous structures typical of M protein. In two M protein-negative group A strains, the reactivity was heterogeneous, revealing a majority of unlabeled, but also some heavily labeled streptococci. Morphologically, these beta 2m-binding bacteria exhibited M protein-like projections in contrast to the smooth surfaces of unlabeled cells.
Isolation and characterization of a monoclonal antibody directed against type 1 fimbriae organelles from Escherichia coli
Authors: Eisenstein B I , Clements J R , Dodd D C
Published: January 2020

We have isolated a mouse immunoglobulin M (IgM) monoclonal antibody directed against type 1 fimbriae from the Escherichia coli K-12-derived strain CSH50. Antibody specificity was demonstrated by (i) the ability of fimbriate but not nonfimbriate bacteria to compete with solid-phase purified fimbriae for antibody binding in an enzyme-linked immunosorbent assay, (ii) the visualized binding of antibody to fimbriae alone by electron microscopy, and (iii) the appearance in a radioimmunoprecipitation assay of a single electrophoretic band comigrating with pure type 1 fimbriae. The monoclonal antibody was further characterized by immunoblot analysis and compared with previously prepared rabbit anti-fimbrial antisera. Whereas the monospecific but polyvalent antisera recognized both fimbrial monomeric subunits and non-disaggregated fimbriae organelles, the monoclonal antibody recognized only the intact organelles even when the samples were prepared under nondenaturing conditions. The monoclonal antibody, therefore, might be directed against an epitope spanning two (or more) adjacent fimbrial subunits.
Pathogenesis of change in the upper respiratory tracts of turkeys experimentally infected with an Alcaligenes faecalis isolate
Authors: Gray J G , Roberts J F , Dillman R C , Simmons D G
Published: January 2020

The course of changes within the upper respiratory tracts of turkey poults experimentally infected with Alcaligenes faecalis was studied. The initial change observed (5 days post-inoculation) was colonization of the upper respiratory tract by the bacterium. Changes in the nasal turbinates and trachea were first apparent as a focal loss of cilia but subsequently developed into a general loss of cilia (11 days post-inoculation). Eventually, the entire ciliated epithelial layer in the cranial region of the trachea was lost (13 days post-inoculation). With the loss of cilia and ciliated cells, a highly viscous mucus was able to accumulate in the anterior one-half to two-thirds of the trachea. In addition, changes in the gross structure of the trachea (flaccid trachea) were observed in all poults inoculated with A. faecalis. There was an apparent gradation in the severity of these changes from severe in the cranial region of the trachea to mild in the region just anterior to the bronchial bifurcation. The observations resulting from A. faecalis infection indicated two major tracheal changes responsible for the chronic and sometimes severe nature of this disease. These changes included a loss of ciliary activity and a flaccid trachea which together resulted in the accumulation and stasis of mucus and tracheal collapse.
In vitro parasite-monocyte interactions in human leishmaniasis: effect of enzyme treatments on attachment
Authors: Wyler D J , Suzuki K
Published: January 2020

Essential to the pathogenesis of leishmaniasis is the ability of Leishmania spp. to attach to mononuclear phagocyte surfaces before entering this host cell which they parasitize. We have investigated the attachment phase of infection in vitro by quantitating the percent of human peripheral blood monocytes pretreated with cytochalasin (to prevent parasite entry) to which tissue-derived L. tropica amastigotes will attach during coincubation at 37 degrees C in serum-free medium. We determined that pretreatment of parasites with trypsin, chymotrypsin, Pronase, and neuraminidase reduced attachment. In contrast, parasites treated with beta-galactosidase had an enhanced ability to attach to host cells. Treatment of monocytes with chymotrypsin and Pronase, but not with trypsin or neuraminidase, reduced attachment of untreated amastigotes. We propose that in vitro amastigote attachment under serum-free conditions depends on the interaction of protein determinants on the surface of both parasite and host cell.
Serum containing tumor necrosis factor is cytotoxic for the human malaria parasite Plasmodium falciparum
Authors: Haidaris C G , Haynes J D , Meltzer M S , Allison A C
Published: January 2020

Sera (BCG-lipopolysaccharide [LPS] serum) were obtained from mice infected with Mycobacterium bovis BCG 2 h after intravenous administration of bacterial endotoxin (LPS). Varying concentrations of sera were added to cultures of Plasmodium falciparum-infected human erythrocytes; parasite viability was assessed by hypoxanthine incorporation after 4 days in culture. At concentrations of 1 to 3%, cultures treated with BCG-LPS serum showed a two- to threefold increase in hypoxanthine incorporation; at higher concentrations (4 to 8%), hypoxanthine incorporation fell to 2 to 5% of that in control cultures. Concurrent assays with control sera (from untreated mice or mice treated with BCG or LPS alone) caused some stimulation but no inhibition at up to 8% concentration. Examination of cultures treated with BCG-LPS serum showed morphological, deterioration of parasites within erythrocytes. The presence of tumor necrosis factor in the BCG-LPS serum was confirmed by using a standard L-cell cytotoxicity assay. In addition, rabbit antiserum against partially purified tumor necrosis factor protected intraerythrocytic forms of P. falciparum from the toxic effects of BCG-LPS serum. These data suggest that the factor in BCG-LPS serum that is toxic to P. falciparum in human erythrocytes is antigenically similar or identical to tumor necrosis factor. This nonantibody mediator of killing may play a role in human malaria.
Cell-free released components of Streptococcus sanguis inhibit human platelet aggregation
Authors: Herzberg M C , Brintzenhofe K L , Clawson C C
Published: January 2020

To study the role of surface components in the selective binding and aggregation of platelet-rich plasma (PRP) by strains of viridans streptococci, we treated the binding, aggregation strain Streptococcus sanguis I 2017-78 by sonication or trypsinization. Morphologically identifiable electron-dense fibrils were released from the cell wall, apparently from an inner electron-dense layer, under conditions that left cells intact. These controlled conditions were determined to cause submaximal loss in adhesion to platelet ghosts and PRP aggregation by treated, washed S. sanguis. Soluble components were recovered from the controlled sonic or L-(tosylamido 2-phenyl)ethyl chloromethyl ketone-trypsin treatments. Each showed dose-response inhibition of aggregation when preincubated with PRP before challenge with fresh, untreated S. sanguis. The time to onset of PRP aggregation was inhibited by 50% with 0.2 mg of TPCK-trypsin peptides or 1.0 mg of the sonicate per ml per 2 X 10(8) platelets. Components of both preparations were immunologically cross-reactive, but lipoteichoic acid was not a major antigen of either. By weight, the TPCK-trypsin peptides were virtually all protein; the sonicate residues identified were about 50% protein and 7% hexose. Each was a complex mixture of components as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. More than 8 TPCK-trypsin peptides and 16 sonicate components were so identified. In contrast, at least four or five components from either preparation were recognized as surface determinants by a rabbit antiserum to whole homologous microbes. Platelet-binding ligands of S. sanguis could be among these determinants.
Antigenic relatedness of two strains of hepatitis A virus determined by cross-neutralization
Authors: Lemon S M , Binn L N
Published: January 2020

Cell culture-adapted HM-175 (Australia) and PA-21 (Panama) strains of hepatitis A virus were compared in a cross-neutralization radioimmunofocus inhibition assay. The ratio of antibody titers achieved with two sera against the two viruses differed by less than twofold, indicating a high degree of antigenic relatedness between epidemiologically disparate strains of virus.
Evaluation of the A/Seal/Mass/1/80 virus in squirrel monkeys
Authors: Murphy B R , Harper J , Sly D L , London W T , Miller N T , Webster R G
Published: January 2020

An influenza A virus isolated from seals [A/Seal/Mass/1/80 (H7N7)] and an isolate of this virus obtained from a human conjunctiva were evaluated for replication and virulence in squirrel monkeys. When the seal virus was administered intratracheally, it replicated in lungs and nasopharynges and induced illness almost to the same extent that a human influenza A virus [A/Udorn/72 (H3N2)] did. In one monkey that died of pneumonia, the seal virus was recovered from spleen, liver, and muscle as well as lung. After conjunctival administration in monkeys, the seal virus replicated to a peak titer in the conjunctivae 30-fold greater than that attained by the human virus, but this difference was not statistically significant. In contrast, the seal virus replicated less well than the human virus in the tracheae and nasopharynges when administered by the conjunctival route. These results indicate that the seal virus can replicate efficiently in primates, that it can spread systemically, and that it might differ from human virus in being able to replicate slightly better in primate conjunctival tissue.
Detection and expression of DNA homologous to the tox gene in nontoxinogenic isolates of Corynebacterium diphtheriae
Authors: Groman N , Cianciotto N , Bjorn M , Rabin M
Published: January 2020

Three probes have been described which can be used to detect the presence of DNA sequences homologous to the tox gene of Corynebacterium diphtheriae. Probes "A" and "B" detected sequences coding for A and B fragments of diphtheria toxin, respectively. The third "A-B" probe contained both the A and B coding sequences. The B probe was completely unambiguous in detecting only toxin-related sequences, and the A probe was only slightly less so. The efficacy of the probes was tested on a series of toxinogenic and nontoxinogenic isolates of C. diphtheriae. All isolates which were toxinogenic as characterized by the gel immunodiffusion technique gave positive reactions with the probes. Of particular interest was the finding that 14 of 43 nontoxinogenic isolates also carried DNA homologous to both the A and B probes. All 14 isolates were nontoxinogenic by the rabbit intracutaneous test as well as by the gel immunodiffusion test; however, 12 of them produced ADP-ribosylating activity, whereas two were negative. The isolates producing ADP-ribosylating activity belonged to a cohort of cultures, of which 11 were isolated in South Dakota and 1 was isolated in Montana. Genomic DNAs of all 12 appeared to be identical when restriction enzyme digest patterns were compared, and the same fragment carried the tox gene in all of them. The tox-bearing nontoxinogenic isolates from Alaska and Florida each had unique restriction patterns and did not produce ADP-ribosylating activity. A number of genomic fragments of all the tox-bearing nontoxinogenic isolates hybridized with beta converting phage DNA. The significance of these observations to the natural history of diphtheria was discussed.
Candidacidal activity of myeloperoxidase: mechanisms of inhibitory influence of soluble cell wall mannan
Authors: Wright C D , Bowie J U , Gray G R , Nelson R D
Published: January 2020

We have previously demonstrated the ability of human neutrophil myeloperoxidase to bind to mannan isolated from Candida albicans. Mannan may therefore be a primary component of the yeast cell wall which provides for binding of myeloperoxidase, a requirement potentially important for the candidacidal activity of the enzyme. In this report, we describe experiments to consider the relationship of the mannan-binding activity of myeloperoxidase to its candidacidal activity and the possibility that free mannan may inhibit myeloperoxidase-mediated candidacidal activity. We observed that binding of myeloperoxidase to the target yeasts was required for killing of C. albicans. We also observed that addition of soluble mannan significantly reduced myeloperoxidase-mediated killing of the yeasts in a dose-dependent manner by antagonizing binding of myeloperoxidase. Soluble mannan was demonstrated to have a similar dose-dependent inhibitory effect on neutrophil-mediated candidacidal activity without influencing phagocytosis of the organism. On the basis of these observations, we speculate that mannan solubilized in plasma and tissue fluid may interfere with neutrophil-mediated host defense against Candida infection.
Immunogenicity of Pseudomonas aeruginosa outer membrane antigens examined by crossed immunoelectrophoresis
Authors: Lam J S , Mutharia L M , Hancock R E , Høiby N , Lam K , Baek L , Costerton J W
Published: January 2020

By crossed immunoelectrophoresis 36 different anode-migrating antigens were demonstrated in sonicated antigen preparations of Pseudomonas aeruginosa. We numbered these antigens to establish a reference precipitin pattern. Antigen no. 31 was identified as the lipopolysaccharide (LPS) antigen, because it was found to be responsible for the O-group specificity and because it reacted with anti-LPS monoclonal antibodies and with Limulus amoebocyte lysate. Purified outer membrane proteins F (porin), H2, and I used as antigens formed precipitins with the reference antibodies, thus establishing their antigenicity. LPS that copurified with protein F and slightly contaminated protein H2 was detectable as an extra precipitin (antigen no. 31). The use of monoclonal antibodies specific for smooth LPS and rough LPS revealed different antigenic determinants in the LPS molecule and suggested that antigen no. 5 could be the core region of the LPS which is equivalent to the rough LPS. Antibodies against these outer membrane antigens were detected in patients with chronic P. aeruginosa pneumonia and in patients with acute P. aeruginosa bacteremia. Antibodies with the same specificity were also found in rats chronically infected with P. aeruginosa 7 days postinfection. This demonstrates the surface accessibility and antigenic reactivity of outer membrane antigens.
Antigenic heterogeneity of Bacteroides intermedius as recognized by monoclonal antibodies
Authors: Gmür R , Guggenheim B
Published: January 2020

Four hybrid cell lines secreting monoclonal antibodies against antigens of Bacteroides intermedius were generated by fusing murine NSI cells with splenocytes from a rat immunized with B. intermedius strain OMZ248. An enzyme-linked immunosorbent assay was used to analyze the distribution of the recognized antigens on 39 strains from various Bacteroides species and on 5 strains from other genera. Only Bacteroides species B. intermedius, B. loescheii, B. melaninogenicus, and B. corporis were found to express at least one of the recognized antigens. Strains of the two asaccharolytic black-pigmenting Bacteroides species were negative. Among the strains capable of binding to one or more of the monoclonal antibodies, five groups with different reactivity patterns could be distinguished. Two of the monoclonal antibodies were specific for B. intermedius. The B. intermedius strains were metabolically almost identical, expressed at least three of the recognized antigens, and fell into three distinct antibody reactivity groups, suggesting a tentative separation of this species into three new serogroups. Oral and nonoral isolates of B. intermedius were, however, not distinguished by the monoclonal antibodies. One monoclonal antibody was directed against an antigen strongly expressed on all saccharolytic black-pigmenting Bacteroides strains tested so far, thus confirming the previously noted antigenic relationship between the species which had emerged from the former B. melaninogenicus subsp. intermedius and B. melaninogenicus subsp. melaninogenicus groups.