-
Volume 39,
Issue 4,
1993
Volume 39, Issue 4, 1993
- Articles
-
-
-
A new Brevibacterium sp. isolated from infected genital hair of patients with white piedra
More LessSummaryA new aerobic gram-positive non-sporeforming bacillus has been isolated from infected genital hair of patients with white piedra in association with Trichosporon beigelii. This species has been characterised morphologically, nutritionally, by DNA base composition, cell-wall analysis and cellular fatty-acid profile on the basis of 14 isolates. The G + C content of DNA is 63.05 mol%. Cell walls possess meso-diaminopimelic acid (Type IV) and the sugars glucose, galactose, xylose and ribose; mycolic acids are not present. The species has a distinct colonial and microscopic morphology, is strongly proteolytic and produces methanethiol. These findings and the cellular fatty-acid profile are compatible with the genus Brevibacterium. A new species is proposed based on the following characters: Colonial and microscopic growth and morphology; conditions for rod-to-coccus cycle; ribose utilisation; and tellurite reduction. The type strain has been named Brevibacterium mcbrellneri E2cr (ATCC 49030). The strong proteolytic properties may be the mechanism of pathogenesis.
-
-
-
-
The production of porphyrins from δ-aminolaevulinic acid by Haemophilus parainfluenzae
More LessSummaryPorphyrin production by the haemin-independent Haemophilus parainfluenzae in the diagnostic porphyrin test, which determines the X-factor requirement in Haemophilus spp., was analysed quantitatively by applying modern high-performance liquid chromatographic (HPLC) methods. Ion-pair reversed-phase HPLC enabled the simultaneous separation of all porphyrin intermediates and their isomers of haem biosynthesis produced by the bacteria. The pH-dependence of porphyrin production and the respective composition of the porphyrins within the bacterial cells and in the supernate were investigated. A pH optimum of 6.9—8.0 for the production of porphyrins was found and there were marked differences in the porphyrin profiles at different pH values.
-
-
-
Serological response of sheep to plasmid-encoded proteins of Yersinia species following natural infection with Y. enterocolitica and Y. pseudotuberculosis
More LessSummaryA prospective study of the serological response to natural infection with Yersinia enterocolitica and Y. pseudotuberculosis was performed in an experimental flock of sheep. A preliminary investigation with immunoblotting techniques showed that lambs infected with virulent Yersinia spp. produced antibodies to several yersinia outer-membrane proteins (yops) encoded by a virulence plasmid (pYV) of Y. enterocolitica or Y. pseudotuberculosis. Thereafter, an enzyme immunoassay (EIA) was developed to measure antibodies to yops. Criteria for interpreting the EIA were established by examining sera from a negative control population of lambs which had not been infected with Yersinia spp. since birth. Test samples comprised 25 pairs of pre- and post-infection sera from animals with bacteriologically proven infections with Yersinia spp. The results showed that infection of lambs with pYV-bearing strains of Y. enterocolitica or Y. pseudotuberculosis invariably evoked a significant antibody response to yops, even though all the infections were subclinical. No animal infected with so-called “environmental”, pYV -negative Yersinia spp. seroconverted to yops. EIA with yops as antigen provided a sensitive and specific means to diagnose subclinical infection of lambs with virulent Yersinia spp.
-
-
-
Comparison of antimicrobial susceptibility, β-lactamase production, plasmid analysis and serum bactericidal activity in Edwardsiella tarda, E. ictaluri and E. hoshinae
More LessSummaryAntimicrobial susceptibility profiles of clinical and environmental isolates of Edwardsiella demonstrate that the three species are susceptible to β-lactam antibiotics. All strains were susceptible to two quinolones tested and to gentamicin and doxycycline. E. tarda and E. hoshinae were resistant to clindamycin, whereas E. ictaluri was moderately susceptible. β-Lactamase was produced by all strains of E. tarda, but not by E. hoshinae or E. ictaluri. A 54-kb plasmid was detected in six of 13 E. hoshinae strains. Five of the 10 E. tarda isolates studied gave an identical plasmid pattern of four plasmids ranging in size from 76-kb to 5.0kb. One strain exhibited a 54-kb plasmid; four strains did not contain plasmid DNA. All E. ictaluri isolates contained a 5.7-kb and a 4.9-kb plasmid. E. tarda and E. ictaluri strains were resistant to human serum 20%; 12 of 13 strains of E. hoshinae were also serum resistant. Serum resistance may play an important part in the pathogenicity of these species.
-
-
-
The production of HlyA toxin by Proteus penneri strains
More LessSummaryTwelve diverse strains of Proteus penneri of clinical origin all produced a calcium-dependent haemolysin, unlike most other Proteus spp. In most strains the haemolysin was secreted into the medium during early exponential growth and lysed not only of a variety of erythrocyte types from several animals including man, but also human neutrophils and human embryo lung fibroblasts. The haemolysin was a protein of 107 kDa, the same size as Escherichia coli H1yA, and it reacted with antiserum to E. coli H1yA. Because of its similarity in size, antigenicity and range of action to the H1yA virulence factor of E. coli, P. penneri H1yA is believed to be an important virulence factor for this organism. It was degradable by an EDTA-sensitive protease—probably the IgA protease—to inactive fragments. The interaction of P. penneri H1yA and IgA protease in vivo and the origin of H1yA, which has now been found in many diverse bacteria, are discussed.
-
-
-
Intrathecal antibody synthesis in Lyme neuroborreliosis: Use of recombinant p41 and a 14-kDa flagellin fragment in ELISA
More LessSummaryThe intrathecal synthesis of IgM and IgG antibodies to Borrelia burgdorferi sonicate, to recombinant flagellin (41 kDa) and to a tryptic peptide of the flagellin (14-kDa fragment) was determined by ELISA in paired cerebrospinal fluid (CSF) and serum samples from 35 patients with Lyme neuroborreliosis (LNB) and in 10 patients with neurosyphilis. The antibody index (AI = QBbQIg) was calculated from the ratio between CSF/serum quotients for specific antibodies (QBb) and total immunoglobulins (QIg). For the examination of IgG antibodies, the sonicate ELISA was performed with and without pre-absorption with Treponema phagedenis. Of 35 patients with LNB, 31 had intrathecal IgG response to B. burgdorferi demonstrated by sonicate ELISA (24 after absorption of cross-reactive anti-bodies), 29 had a response demonstrated by flagellin ELISA and 21 of 35 by 14-kDa ELISA. In patients with neurosyphilis the AI (IgG) was elevated in the sonicate ELISA in 7 of 10 samples (none of 10 after absorption of cross-reactive antibodies), in the flagellin ELISA in 5 of 10 samples and in the 14-kDa ELISA in none of 10 samples. Intrathecal synthesis of IgM antibodies to B. burgdorferi was demonstrated in patients with neuroborreliosis by sonicate ELISA in 20 of 35 samples, by flagellin ELISA in 16 of 35 samples and by 14-kDa ELISA in 9 of 35 samples. No intrathecal synthesis of B. burgdorferi-specific IgM could be detected by any assay in patients with neurosyphilis. The highest specificity and sensitivity was achieved with findings from IgG and IgM AI determinations in 14-kDa and sonicate ELISA (after pre-absorption with T. phagedenis) providing positive results in 32 (91.4%) of 35 patients.
-
-
-
Use of PCR-mediated amplification of Mycobacterium leprae DNA in different types of clinical samples for the diagnosis of leprosy
More LessSummaryDNA of Mycobacterium leprae, obtained by a highly efficient nucleic acid extraction procedure, was used for standardisation of the amplification of an M. leprae-specific repetitive sequence by use of the polymerase chain reaction (PCR). With pure DNA, M. leprae-specific amplification was obtained with as low as 100 ag (1 ag = 10-18 g) of target DNA, a quantity equal to about one-tenth of the bacterial genome. Optimal processing of different types of clinical samples such as biopsy material, blood and lymph fluid, from multibacillary leprosy patients, was studied. Simple freezing-boiling cycles in the presence of Triton X100, with some additional sample-specific modifications such as pre-treatment with NaOH to eliminate PCR inhibitors, was found to be sufficient to yield amplification of bacterial DNA in samples from paucibacillary patients. Clinical samples from 27 untreated leprosy patients, covering the various clinical forms of the disease, and with a bacterial index ranging from 5 + to 0, were collected and processed for PCR analysis. After hybridisation of the amplified material with a specific sequence, 25 of 27 patients analysed gave positive results for M. leprae in at least one of the samples. The potential of PCR for the diagnosis of leprosy is discussed.
-
-
-
Lectin typing of methicillin-resistant Staphylococcus aureus from Singapore, England and Wales, and Denmark
More LessSummaryMethicillin-resistant Staphylococcus aureus (MRSA) isolates from a possible outbreak in Singapore (84) were examined together with all MRSA isolated in Denmark in 1986—1990 (58) and 14 distinct epidemic and 10 distinct single hospital strains from England and Wales. All 84 Singapore isolates were phage typed routinely and 52 isolates were further analysed together with the Danish isolates with an additional set of experimental phages and by lectin typing. The British strains, previously phage typed in the same way, were lectin typed. The following lectins were used: Wheat-term agglutinin, soy-bean agglutinin, tomato lectin and Concanavalin-A. Routine phage typing of the Danish isolates showed that 41 isolates belonged to 19 different types; 17 isolates were non-typable (NT). Addition of experimental phage typing and lectin typing enhanced discrimination to 47 types. The 24 British strains could be divided into nine “lectin types”. Sixty-one of the isolates from Singapore were non-typable by phage typing; the remaining 23 strains belonged to five types. Further examination of 52 isolates with the experimental set of phages and by lectin typing gave 14 closely related types; 48% of these isolates belonged to only two types.
-
-
-
Virulence patterns of Vibrio cholerae non-01 strains isolated from hospitalised patients with acute diarrhoea in Calcutta, India
SummaryA collection of 28 strains of Vibrio cholerae non-O1 isolated during a 3-year period (1989—1991) from hospitalised patients with acute diarrhoea in Calcutta, India, were examined with regard to virulence-associated factors. Of the 28 isolates (each representing a case), 18 were isolated as the sole infecting agent; the remaining 10 were recovered as co-cultures from cases infected with V. cholerae O1. Of the strains isolated in this study, 82% could be serotyped, with serovars O5 (32.1%), O11 and O34 (14.3% each) predominant. Serovars O7, O14, O34, O39 and O97 were associated exclusively with sole infections. Two strains of V. cholerae non-O1 produced anti-cholera toxin IgG-absorbable cholera toxin (CT). Both CT-producing V. cholerae non-O1 strains hybridised with the DNA probe specific for the zonula occludens toxin (ZOT) but none of the remaining 26 strains hybridised with the ZOT probe. The majority of the strains were cytotoxic for CHO, HeLa and Vero cells, with end-point titres of 4—512. Fewer strains produced a cytotonic effect, with end-point titres of 2—16. Of the 28 strains of V. cholerae non-O1 examined, 75%, 75%, 25% and 14.3% produced haemolysin that was active against erythrocytes of rabbit, sheep (Eltor haemolysin), chicken and man, respectively. Strains that produced a haemolysin active against both rabbit and sheep erythrocytes were dominant (35.7%). Ten (35.7%) of the 28 strains examined showed cell-associated haemagglutinating activity on human blood. Of the 10 strains, nine were isolated as sole pathogen and only one strain was associated with mixed infection. Three distinct patterns of inhibition by sugars were detected; inhibition of haemagglutination by mannose 1% but not by fucose and galactose 1% was the dominant haemagglutination inhibition pattern. Six different virulence phenotypes were encountered among strains of V. cholerae non-O1 in this study. The prominent phenotype, which was associated commonly with isolates from patients solely infected by V. cholerae non-O1, was exhibited by strains that produced the Eltor haemolysin, a cytotoxin and a cell-associated haemagglutinin. The production of cell-associated haemagglutinin appeared to be the only distinctive phenotype that could distinguish between isolates from patients solely infected with V. cholerae non-O1 and those associated with mixed infections. From this study, it is apparent that the virulence of V. cholerae non-O1 is multifactorial and mediated by several traits functioning in an integrated fashion. The clinical significance of V. cholerae non-O1 must be assessed in its totality; the presence of a single factor should not be construed as the cause of enteropathogenicity.
-
- Editorial
-
- Review Article
-
-
-
Fusobacteria: New taxonomy and related diseases
K. W. Bennett and A. EleySummaryFusobacteria are anaerobic gram-negative bacilli. Since the first reports in the late nineteenth century, various names have been applied to these organisms, sometimes with the same name being applied to different species. More recently, not only have there been changes to the nomenclature, but also attempts to differentiate between species which are believed to be either pathogenic or commensal or both. Because of their assacharolytic nature, and a general paucity of positive results in routine biochemical tests, laboratory identification of the fusobacteria has been difficult. However, the application of novel molecular biological techniques to taxonomy has established a number of new species, together with the subspeciation of Fusobacterium necrophorum and F. nucleatum, and provided new methods for identification. The involvement of fusobacteria in a wide spectrum of human infections causing tissue necrosis and septicaemia has long been recognised, and, more recently, their importance in intra-amniotic infections, premature labour and tropical ulcers has been reported.
-
-
- Announcements
-
- Book Received
-
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
