-
Volume 28,
Issue 3,
1989
Volume 28, Issue 3, 1989
- Articles
-
-
-
Use of an antigen-capture assay for characterisation of monoclonal antibodies to mycobacterial lipoarabinomannan
More LessSUMMARYMonoclonal antibodies directed to six separate antigen molecules of Mycobacterium leprae have been tested in an antigen-capture assay based on combined use of polyclonal (“capture”) and monoclonal (“detector”) antibody reagents. This approach provides a potentially versatile, sensitive and specific assay for detection and relative quantitation of M. leprae antigens. Characterisation of monoclonal antibodies to mycobacterial lipoarabinomannan (LAM-B) by the antigen-capture assay indicates that some of the antigenic determinants present on LAM-B from M. leprae may be either absent altogether or present at much lower concentrations on the corresponding LAM-B structure from M. tuberculosis.
-
-
-
-
Enterotoxin production by Staphylococcus aureus isolates from cases of septicaemia and from healthy carriers
SUMMARYIn a prospective study, 52 Staphylococcus aureus isolates from individual patients with septicaemia and 27 nasal strains from separate, healthy carriers were compared for production of a range of extracellular proteins and toxins. Whereas there was no difference (p > 0.05) between septicaemic and nasal isolates with respect to incidence of α, β, γ and haemolysins, toxic shock syndrome toxin-1 or staphylokinase production, the incidence of enterotoxin A, B, and C production was higher among isolates from septicaemia (p < 0.01). Of the isolates from septicaemia, 33 (63%) produced enterotoxins A, B, C or D alone or in combination. Only three (11%) of the nasal isolates produced a single enterotoxin, enterotoxin D. Of the isolates from septicaemia, 67% were hospital-acquired and > 25% of these were endemic, methicillin-resistant (MRSA) strains. All MRSA strains produced either enterotoxin A, or enterotoxin B, or both. These findings suggest a possible role for enterotoxins in the pathogenesis of S. aureus disease other than food poisoning.
-
-
-
Candidacidal mechanisms of peritoneal macrophages activated with lymphokines or γ-interferon
More LessSUMMARYThe mechanisms by which resident peritoneal macrophages, activated in vitro by lymphokines (LK) or recombinant γ-interferon (IFN), kill Candida parapsilosis or C. albicans were studied. Resident non-activated peritoneal macrophages killed C. parapsilosis (55.5% SD6.8%), but not C. albicans. This killing was completely inhibited by superoxide dismutase (SOD), partially by dimethyl sulphoxide (DMSO), but not by catalase or azide. Killing correlated with a brisk lucigenin-dependent chemilumi-nescence(CL) response by macrophages interacting with C. parapsilosis. No enhanced luminol-dependent CL response was observed in this system. This suggests that C. parapsilosis is killed by resident macrophages via a mechanism dependent on the presence of superoxide anion. By contrast, killing of C. parapsilosis by activated macrophages (49.0%SD5.9%) was not inhibited by SOD or DMSO, suggesting the induction of a non-oxidative candidacidal mechanism. C. albicans was killed only by macrophages activated with IFN (52.0%SD3.7%) or LK (55.7%SD2.8%). Inhibition of killing by SOD was greater in IFN-than in LK-activated macrophages. Conversely, killing by LK-, but not IFN-, activated macrophages was significantly inhibited by catalase, DMSO or azide. The killing by LK-activated macrophages, and its inhibition by scavengers, correlated with the luminol-dependent CL response. The non-killing resident macrophages interacting with C. albicans made lucigenin-dependent CL responses similar to those of activated macrophages. The mechanisms enabling killing of C. albicans induced by activation appear to be different for LK and IFN, and appear to depend upon the myeloperoxidase systems and superoxide respectively.
-
-
-
Isolation of mucoid strains of Pseudomonas aeruginosa from non-cystic-fibrosis patients and characterisation of the structure of their secreted alginate
More LessSUMMARYWhen the incubation period of primary isolation plates was extended to 48 h, mucoid strains of Pseudomonas aeruginosa were found in specimens from various infected sites in patients who did not have cystic fibrosis. The 17 mucoid isolates were characterised in terms of mucoid type, pyocin type, and their sensitivity or resistance to seven β-lactam and two aminoglycoside antibiotics. The carbohydrate, uronic acid (alginate) and protein content of the water-soluble extracellular material of 15 strains was determined. This material was fractionated by ion-exchange chromatography, and the presence of alginate confirmed by the chemical assay of uronic acids and their quantitation by gas-liquid chromatography. Uronic acids were absent from a nonmucoid revertant of one strain. The strains produced alginate with a high content of mannuronic acid and substituted with O-acetyl groups. By proton nuclear magnetic resonance (1H-nmr) analysis the alginate from three strains was shown to lack polyguluronate blocks in its structure. These properties are also found in the alginate of mucoid P. aeruginosa strains from patients with cystic fibrosis.
-
-
-
Phagocytosis and ingestion of influenza virus by human polymorphonuclear leucocytes in vitro: Electronmicroscopy studies
More LessSUMMARYInteraction of human polymorphonuclear leucocytes (PMNL) and influenza virus (IFV) was studied in vitro. At 0°C, the viral particles were bound extensively to the surface of the PMNL membrane with a ratio of about 1000 virus particles to a single PMNL. The binding was sensitive to neuraminidase, suggesting attachment through sialo-compound receptors. At 37°C, the virus particles disappeared rapidly from the cell surface, about half of them being eluted and the remainder being endocytosed into the cytoplasmic vesicles. Immuno-gold electronmicroscopy suggests that the virus particles are ingested into phagosomal vesicles and lysed.
-
-
-
Identification and comparative analysis of the lactoferrin and transferrin receptors among clinical isolates of gonococci
B. C. Lee and L. E. BryanSUMMARYNeisseria gonorrhoeae expresses receptors for both lactoferrin (LF) and transferrin (TF). To determine whether qualitative or quantitative changes in these receptors, or both, correlate with the pattern of disease due to N. gonorrhoeae, a dot binding assay with whole cells was used to measure the absolute receptor levels expressed during iron-limited growth of strains isolated from asymptomatic patients and patients with urethritis, cervicitis, pelvic inflammatory disease and disseminated infection. Lactoferrin and transferrin receptor complexes were purified by affinity chromatography and their protein profiles were compared. The molecular weights of the LF and TF receptor complexes from a representative sample of gonococci were homogeneous. We conclude that there is no relationship between the LF and TF receptor levels and disease manifestation, auxotype or serotype.
-
-
-
Genetic evidence for a chromosomally integrated multiresistance plasmid in Salmonella dublin
More LessSUMMARYOf 1099 isolates of Salmonella dublin during 1985–86, 11 (1%) were resistant to three or more antibiotics. Strain S4659/85, a multiresistant isolate, lacked autonomous R plasmids but showed incompatibility with incH2 plasmids and donated resistance determinants in matings. Transconjugants acquired incomplete R plasmids which integrated stably into a specific chromosomal site. These data provide an insight into the behaviour of R plasmids in S. dublin.
-
-
-
Formation of methylglyoxal by bacteria isolated from human faeces
More LessSUMMARYBacteria present in the human gut may produce methylglyoxal—a cytotoxic substance in mammals. This was investigated by studying the activity of methylglyoxal synthase, which produces methylglyoxal from dihydroxyacetone phosphate, and methylglyoxal concentration in growth medium of various bacteria isolated from human faeces. Facultative and strictly anaerobic bacteria isolated from faeces were able to produce methylglyoxal in both defined and complex media. Proteus spp. produced large amounts of methylglyoxal and had the greatest methylglyoxal synthase activity. Supplementing defined medium for facultative anaerobes with glucose 1% w/v did not significantly alter enzyme activity or methylglyoxal production. Inclusion of short chain fatty acids or bile acids in the medium reduced methylglyoxal synthase activity and methylglyoxal production by Proteus spp. None of the organisms examined had amine oxidase activity which could have contributed to methylglyoxal production from aminoacetone.
-
-
-
Recovery of spores of Clostridium difficile altered by heat or alkali
More LessSUMMARYThe effect of heating or alkali-treatment on spore recovery in ordinary growth medium was examined for four strains of Clostridium difficile. Heating spores at 80°C for 10 min produced 95.50–99.95% decreases in the recovery rates. Treatment with 0.1 n NaOH for 15 min produced 99.47 and 99.83% decreases in spore recovery rates for two of the four strains. The influence of either addition of lysozyme after treatment with sodium thioglycollate (thioglycollate-lysozyme method) or addition of sodium taurocholate (taurocholate method) on recovery of heat- or alkali-treated C. difficile spores was also examined. Viable spores of all strains altered by heating at 90°C or 100°C for 10 min could not be recovered at all by the taurocholate method. Nor did this method allow recovery of alkali-altered spores treated with > 0.2 n NaOH for 15 min. On the other hand, 10–47% of altered spores heated at 90°C for 10 min were recovered by the thioglycollate-lysozyme method, and alkali-altered spores treated with 0.1—0.3 n NaOH for 15 min were as completely recovered by this method as untreated spores. These results indicate that the thioglycollate-lysozyme method is more effective than the taurocholate method for recovery of the heat- or alkali-altered C. difficile spores.
-
-
-
Antibodies against Trichosporon beigelii in vaginal washings from asymptomatic women
More LessSUMMARYTrichosporon beigelii was isolated from vaginal washings from three asymptomatic women. All three women had IgG or IgA anti-T. beigelii antibody titres ⩾ 20 when tested by an indirect immunofluorescence assay against the three strains isolated. Titres ⩾ 160 were found when each patient was tested against her own isolate. Patients with Candida albicans vulvovaginitis, or from whom C. albicans or Toruloposis glabrata was isolated from vaginal washings, or who had negative cultures for yeasts, had titres ⩽ 20.
-
-
-
A pyrolysis mass spectrometry study of fusobacteria
More LessSUMMARYStrains of fusobacteria (143) were examined by pyrolysis mass spectrometry (Py-MS) with a Horizon Instruments PYMS 200X. Fusobacterium necrogenes, F. necrophorum, F. nucleatum, F. mortiferum, F. varium, F. gonidiaformans, F. naviforme, F. russii and Leptotrichia buccalis were discriminated. Strains of fusobacteria isolated from tropical ulcers, although similar to F. mortiferum in conventional tests, were discriminated from each of these species in Py-MS. Identification of 416 spectra to species level agreed with conventional bacteriological methods in 91.8% of cases, was equivocal in 3.4% and disagreed in 4.
-
Volumes and issues
-
Volume 74 (2025)
-
Volume 73 (2024)
-
Volume 72 (2023 - 2024)
-
Volume 71 (2022)
-
Volume 70 (2021)
-
Volume 69 (2020)
-
Volume 68 (2019)
-
Volume 67 (2018)
-
Volume 66 (2017)
-
Volume 65 (2016)
-
Volume 64 (2015)
-
Volume 63 (2014)
-
Volume 62 (2013)
-
Volume 61 (2012)
-
Volume 60 (2011)
-
Volume 59 (2010)
-
Volume 58 (2009)
-
Volume 57 (2008)
-
Volume 56 (2007)
-
Volume 55 (2006)
-
Volume 54 (2005)
-
Volume 53 (2004)
-
Volume 52 (2003)
-
Volume 51 (2002)
-
Volume 50 (2001)
-
Volume 49 (2000)
-
Volume 48 (1999)
-
Volume 47 (1998)
-
Volume 46 (1997)
-
Volume 45 (1996)
-
Volume 44 (1996)
-
Volume 43 (1995)
-
Volume 42 (1995)
-
Volume 41 (1994)
-
Volume 40 (1994)
-
Volume 39 (1993)
-
Volume 38 (1993)
-
Volume 37 (1992)
-
Volume 36 (1992)
-
Volume 35 (1991)
-
Volume 34 (1991)
-
Volume 33 (1990)
-
Volume 32 (1990)
-
Volume 31 (1990)
-
Volume 30 (1989)
-
Volume 29 (1989)
-
Volume 28 (1989)
-
Volume 27 (1988)
-
Volume 26 (1988)
-
Volume 25 (1988)
-
Volume 24 (1987)
-
Volume 23 (1987)
-
Volume 22 (1986)
-
Volume 21 (1986)
-
Volume 20 (1985)
-
Volume 19 (1985)
-
Volume 18 (1984)
-
Volume 17 (1984)
-
Volume 16 (1983)
-
Volume 15 (1982)
-
Volume 14 (1981)
-
Volume 13 (1980)
-
Volume 12 (1979)
-
Volume 11 (1978)
-
Volume 10 (1977)
-
Volume 9 (1976)
-
Volume 8 (1975)
-
Volume 7 (1974)
-
Volume 6 (1973)
-
Volume 5 (1972)
-
Volume 4 (1971)
-
Volume 3 (1970)
-
Volume 2 (1969)
-
Volume 1 (1968)
Most Read This Month
