- Volume 42, Issue 2, 1995
Volume 42, Issue 2, 1995
- Editorial
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- Host Response To Infection
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Brucella abortus causes an accelerated repopulation of the spleen and liver of mice by macrophages after their liposome-mediated depletion
More LessSurmmaryDifferent macrophage subsets are present in the spleen, i.e., marginal zone macrophages (MZM), marginal metallophilic macrophages (MMM) and red pulp macrophages (RPM) and all are depleted by a single treatment with liposome-encapsulated clodronate. These macrophages can be distinguished by differences in localisation patterns, membrane antigens and repopulation kinetics after depletion. In experiments on the involvement of splenic macrophages in the humoral immune response, there was an acceleration of the repopulation kinetics of all macrophage subsets in the spleen after intravenous injection of an autoclaved suspension of Brucella abortus 544 (BA 544 antigen). The time required to obtain 100% repopulation in macrophage-depleted control mice was 2 weeks for RPM, 6 weeks for MMM and > 2 months for MZM. However, after BA 544 injection, 100% repopulation was obtained within 4 days in the case of RPM and within 2 weeks in the case of MMM. Acid phosphatase activity, indicating the presence of MZM, had returned to normal levels within 2 months. Acceleration of repopulation was observed only after intravenous administration of antigen preparations from Brucella strains (except strain BA 19). Although BA 544 antigen stimulated the proliferation of precursors of all of the macrophage subsets in the spleen and liver, it also affected mature members of the mononuclear phagocyte system such as MZM and dendritic cells in the spleen.
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- Bacterial Pathogenicity
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Characterisation of a haemolysin related to Vp-TDH produced by a Kanagawa phenomenon-negative clinical isolate of Vibrio parahaemolyticus
More LessSurmmaryThe production of a family of haemolysins—thermostable direct haemolysin (Vp-TDH), Vp-TDH-related haemolysin (Vp-TRH) and Vp-TDH/I—has been reported in clinical isolates of Vibrio parahaemolyticus. This paper describes a fourth type of haemolysin—Vp-TDH/II—produced by a Kanagawa phenomenon-negative clinical isolate of V. parahaemolyticus (O13: K, untypable). Vp-TDH/II was purified by ammonium sulphate precipitation and successive filtrations on DEAE-cellulose, hydroxyapatite, Sepharose 4B and Mono Q columns. Vp-TDH/II was biophysicochemically and immunologically similar to, but not identical to Vp-TDH, Vp-TRH and Vp-TDH/I. Vp-TDH/II stimulated vascular permeability in rabbit skin and was lethal to mice. Purified Vp-TDH/II and viable cells of the Vp-TDH/II-producing strain both induced fluid accumulation in ligated rabbit intestine. The plasmid-determined structural gene for Vp-TDH/II was cloned and the nucleotide sequence determined. The deduced amino acid sequence of Vp-TDH/II differed from those of Vp-TDH, Vp-TRH and Vp-TDH/I.
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Superantigenic exotoxin production by isolates of Staphylococcus aureus from the Kawasaki syndrome patients and age-matched control children
SurmmaryNineteen strains of Staphylococcus aureus were isolated from the throat or the tooth surfaces of 19 cases amongst 127 patients with Kawasaki syndrome (KS) during the acute phases and 11 S. aureus isolates were obtained from five of 17 diseased controls and six healthy controls. The production of exotoxins, particularly superantigenic toxic shock syndrome toxin-1 (TSST-1), coagulase serotype, pigment production, haemolytic activity and tryptophan auxotrophy of these isolates were compared. Among 10 KS S. aureus strains isolated in 1990–1991, five (50%) secreted TSST-1, a higher frequency than two (18 %) of 11 control isolates. In contrast, none of the nine KS strains collected in 1984 produced TSST-1. Four of five TSST-1-secreting KS strains produced white or white to golden pigmentation, whereas the two control strains capable of TSST-1 production formed golden colonies. There were no noticeable differences between S. aureus strains from KS patients and control children in the production of staphylococcal exotoxins A-E, coagulase serotype, haemolysis of sheep erythrocytes and tryptophan auxotrophy. The pathological or aetiological role of a new TSST-1-secreting S. aureus clone in patients with KS was not confirmed.
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Detection by PCR and analysis of the distribution of a fibronectin-binding protein gene (fbn) among staphylococcal isolates
More LessSurmmaryThe fibronectin-binding proteins of Staphylococcus aureus are considered to be important virulence factors for colonisation and infection. The polymerase chain reaction (PCR) was used to detect part of a gene equivalent to the fbn A gene of S. aureus in 120 isolates of staphylococci (S. aureus, S. epidermidis, S. haemolyticus, S. simulans, S. hominis, S. warneri, S. cohnii and S. lugdunensis). Primers specific for the binding domain region of the fbn A gene of S. aureus produced PCR products of the predicted sizes (93 and 207 bp). The identity of the PCR products was confirmed by digestion with Ddel and nucleic acid hybridisation. The fibronectin-binding activity of the staphylococci was determined with a particle agglutination assay (PAA). The fbn gene was found to be present by PCR in 107 of the 120 staphylococci tested, irrespective of their site of isolation, and expression of the gene was detected by PAA in 101 of the 120 strains.
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A re-appraisal of the biological activity of bacteroides LPS
More LessSurmmaryLipopolysaccharides (LPS) were extracted from seven Bacteroides strains by three different techniques: The phenol-water (PW), phenol-chloroform-petroleum (PCP) and Triton-Mg2+ methods. The strains selected included two different B. fragilis strains, one of which was grown in two different media. Yields varied between the strains, growth media and extraction technique, but generally the highest yield by weight was from the PCP method and the lowest from the PW method. The PW method was selected for the greatest amounts of carbohydrate and KDO, and the PCP method for the least. Phosphorus levels were more uniform among all extraction methods. Protein contamination was found in all Bacteroides LPS extracts, with extremely low levels in PW-LPS and the highest levels in material extracted by the PCP and Triton-Mg2+ techniques. No protein contamination could be detected after proteinase K treatment. After silver staining LPS PAGE profiles showed ladder patterns characteristic of smooth LPS for B. vulgatus, B. thetaiotaomicron and the control Escherichia coli O18:K− strains, whereas the other Bacteroides strains showed mainly rough and low Mr material only. The PCP method did not select for high Mr material in the B. fragilis strains; otherwise the LPS profiles for all extraction methods were identical. The biological activities of native and sodium salt form LPS were investigated on a weight for weight basis and compared to that of E. coli O18:K− PW-LPS. Amongst the LPS from Bacteroides strains, those prepared by the PW method were found to have a significantly higher activity in a galactosamine mouse lethality model, in induction of TNF and the Limulus amoebocyte lysate (LAL) assay, than LPS extracted by the PCP or Triton-Mg2+ methods. LPS from Bacteroides strains extracted by the PCP method had consistently low activity in all assays. Comparing PW-LPS from Bacteroides strains with that from E. coli O18:K− in the galactosamine mouse model, the E. coli O18:K− LPS was c. 5000-fold more active than the most active bacteroides LPS. However, in the LAL assay native PW-LPS from both the B. fragilis strains, and B. caccae had higher activities (up to 30-fold) than E. coli O18:K− LPS, with the PW-LPS from the other Bacteroides spp. being up to 15-fold less active than the E. coli O18:K− PW-LPS. In the TNF induction assay, E. coli O18:K− PW-LPS was 4–50-fold more active than bacteroides PW-LPS. In the LAL assay and galactosamine mouse model, native LPS had more activity (c. two-fold) than sodium salt form LPS. There was no clear difference in activity between native and sodium salt form LPS in the TNF induction assay. The results for the LAL and TNF induction assay were re-evaluated relative to KDO concentration. In the TNF induction assay, previously low activities seen on a weight for weight basis were due in part to less KDO being present. However, LAL activity for PCP-LPS was still low after re-evaluation relative to KDO concentration. The molecular basis for the differences in biological activity of bacteroides LPS in relation to extraction methods and chemical composition is not yet understood.
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- Characterisation And Typing Of Micro-Organisms
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Phenotypic characterisation of Acinetobacter strains of 13 DNA-DNA hybridisation groups by means of the Biolog system
More LessSurmmaryA collection of 129 Acinetobacter strains belonging to DNA groups (genomic species) 1–14 (1–7 and 10–12 sensu Bouvet and Grimont; 8 and 13–14 sensu Tjernberg and Ursing) were investigated for their ability to oxidise 95 carbon sources in the Biolog system. The strain groupings obtained by cluster analysis with the Biolog software were compared with the results of DNA-DNA hybridisation studies. Strains of DNA groups 1 (A. calcoaceticus), 2 (A. baumannii), 3 and 13 were linked in one cluster, as were DNA groups 4 (A. haemolyticus) and 6, DNA groups 10 and 11, and DNA groups 8 (A. lwoffii) and 12 (A. radioresistens). Strains of DNA group 5 (A. junii) were grouped in a single cluster with one strain of DNA group 4. Strains of DNA groups 7 (A. johnsonii) and 14 formed separate clusters. With the exception of the linkage of DNA groups 8 and 12, these results correlated with classification of reference strains of the DNA groups by DNA-DNA hybridisation, but six strains of four different DNA groups were not allocated to the clusters of their respective DNA groups. In the case of DNA groups-4, 5, 6, 7, 10, 11 and 14, at least one carbon source oxidation test could be used to differentiate them from the other DNA groups.
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Differences exist in the immunoblotting profiles of cyst and trophozoite antigens of Pneumocystis carinii
More LessSurmmaryThe antigenic profiles of Pneumocystis carinii trophozoites and cysts were compared by immunoblotting with hyperimmune rat sera against cyst and trophozoite antigens. Strong bands corresponding to proteins of 50–60 kDa and 104 kDa were demonstrated in cyst and trophozoite antigens by all antisera. Additional prominent proteins of 81 and 63 kDa and less prominent proteins of 88, 73, 69 and 37 kDa were found only in trophozoite antigen. The latter proteins were recognised by anti-trophozoite and anti-cyst antisera but the 81- and 63-kDa proteins were associated specifically with trophozoites. With cyst-rich antigen, antibodies to the 50–60-kDa protein were detected in only two of 14 sera from P. carinii pneumonia (PCP)-positive rats. With trophozoite-rich antigen, 11 of 24 rats with PCP and one of 18 PCP-negative animals had antibodies to both the 50–60 kDa and 104-kDa antigens. Antibodies to the 81- or 63-kDa antigens were demonstrated in 15 of 24 PCP-positive animals and none of the PCP-negative animals. The use of trophozoites rather than cysts increased the sensitivity of immunoblotting. As trophozoites predominate in PCP, antibody to trophozoite-specific antigens rather than common cyst and trophozoite antigens is likely to be a more useful marker of current infection.
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Typing of Staphylococcus aureus colonising human nasal carriers by pulsed-field gel electrophoresis
More LessSurmmaryColonisation by Staphylococcus aureus in the nares of 120 outpatients and 63 healthy adults was studied for c. 2 years. Two states of carriage of S. aureus were confirmed: Persistent carriage and persistent non-carriage. The states of carriage and non-carriage were quite stable and > 60% of the population of any of the study groups were stable non-carriers. The results of typing the strains isolated from the same individuals at different times with DNA fingerprinting by digestion with Smal enzyme showed that all the stable carriers were persistently infected with the same strain and that changes in the strain seldom occurred.
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- Clinical Infections
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Clostridial infection in children
More LessSurmmaryA survey of the isolation of Clostridium spp. from 1543 specimens sent to anaerobic microbiology laboratories revealed 113 isolates from 107 specimens (7.0% of all specimens) from 96 children. The isolates comprised 43 (38%) unidentified Clostridium spp., 37 (33%) C. perfringens, 13 (12%) C. ramosum, five (4%) C. innocuum, six (5%) C. botulinum, three (3%) C. difficile, two (2%) C. butyricum, and one isolate each of C. bifermentans, C. clostridiiforme, C. limosum and C. paraputrificum. Most clostridial isolates were from abscesses (38), peritonitis (26), bacteraemia (10), and chronic otitis media (7). Predisposing or underlying conditions were present in 31 (32%) cases. These were immunodeficiency (12), malignancy (9), diabetes (7), trauma (7), presence of a foreign body (6) and previous surgery (6). The clostridia were the only bacterial isolates in 14 (15%) cases; 82 (85%) cases had mixed infection. The species most commonly isolated with clostridia were anaerobic cocci (57), Bacteroides spp. (B. fragilis group) (50), Escherichia coli (22), pigmented Prevotella or Porphyromonas spp. (18) and Fusobacterium spp. (10). Most Bacteroides and Escherichia coli isolates with clostridia were from abdominal infections and skin and soft tissue infections adjacent to the rectal area; most pigmented Prevotella and Porphyromonas isolates were from oropharyngeal, pulmonary, and head and neck sites. Antimicrobial therapy was given to all patients, in conjunction with surgical drainage in 34 (35%). Only two patients died. These data illustrate the importance of Clostridium spp. in paediatric infections.
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- Books Received
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Volumes and issues
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Volume 73 (2024)
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Volume 72 (2023 - 2024)
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Volume 71 (2022)
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Volume 70 (2021)
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Volume 69 (2020)
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Volume 68 (2019)
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Volume 67 (2018)
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Volume 66 (2017)
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Volume 65 (2016)
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Volume 64 (2015)
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Volume 63 (2014)
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Volume 62 (2013)
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Volume 61 (2012)
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Volume 60 (2011)
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Volume 59 (2010)
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Volume 58 (2009)
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Volume 57 (2008)
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Volume 56 (2007)
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Volume 55 (2006)
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Volume 54 (2005)
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Volume 53 (2004)
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Volume 52 (2003)
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Volume 51 (2002)
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Volume 50 (2001)
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Volume 49 (2000)
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Volume 48 (1999)
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Volume 47 (1998)
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Volume 46 (1997)
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Volume 45 (1996)
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Volume 44 (1996)
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Volume 43 (1995)
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Volume 42 (1995)
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Volume 41 (1994)
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Volume 40 (1994)
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Volume 39 (1993)
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Volume 38 (1993)
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Volume 37 (1992)
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Volume 36 (1992)
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Volume 35 (1991)
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Volume 34 (1991)
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Volume 33 (1990)
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Volume 32 (1990)
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Volume 31 (1990)
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Volume 30 (1989)
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Volume 29 (1989)
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Volume 28 (1989)
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Volume 27 (1988)
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Volume 26 (1988)
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Volume 25 (1988)
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Volume 24 (1987)
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Volume 23 (1987)
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Volume 22 (1986)
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Volume 21 (1986)
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Volume 20 (1985)
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Volume 19 (1985)
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Volume 18 (1984)
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Volume 17 (1984)
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Volume 16 (1983)
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Volume 15 (1982)
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Volume 14 (1981)
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Volume 13 (1980)
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Volume 12 (1979)
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Volume 11 (1978)
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Volume 10 (1977)
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Volume 9 (1976)
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Volume 8 (1975)
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Volume 7 (1974)
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Volume 6 (1973)
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Volume 5 (1972)
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Volume 4 (1971)
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Volume 3 (1970)
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Volume 2 (1969)
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Volume 1 (1968)