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C C Storey

Publications and source records attributed to C C Storey.

10 recordsLinked to original sources
PubMed1998

Influenza-like episodes in HIV-positive patients: the role of viral and 'atypical' infections.

OBJECTIVES: To document viral and 'atypical' infections in HIV-positive patients and association with influenza-like symptoms. PATIENTS AND METHODS: Monthly culture of urine, faeces and throat swabs in 63 HIV-positive patients (30 asymptomatic and 33 with AIDS-related complex/AIDS) over 5-27 months (with 1125 patient-months of follow-up), with further sample collections during influenza-like episodes. Standard viral detection methods were used. Throat swabs were assessed for Chlamydia sp. by culture and immunoblotting, and for Mycoplasma pneumoniae by polymerase chain reaction. RESULTS: Viruses were detected in 15 (50%) and M. pneumoniae in nine (30%) out of 30 HIV-positive patients during an influenza-like illness. A close temporal relationship with symptoms was observed in 12 (40%) patients: cytomegalovirus in six (20%), M. pneumoniae in three (10%), herpes simplex virus in three (10%), and enterovirus in one (4%). Influenza-like symptoms were more frequent in asymptomatic HIV infection than in AIDS-related complex/AIDS patients (actuarial risk at 1 year, 63 versus 26%; P=0.002), particularly in those with CD4 cell counts >300 x 10(6)/l at enrolment (P=0.002). At least 44% (four out of nine) M. pneumoniae infections were asymptomatic and 78% (seven out of nine) were associated with prolonged excretion (2-17 months). Chlamydia sp. were not detected. CONCLUSIONS: Influenza-like symptoms were more likely to be reported by HIV-positive patients at early stages of disease, possibly as a result of differences in immune responses to viral infection. There was a close association in 40% of cases between the development of symptoms and detection of cytomegalovirus, herpes simplex virus, enterovirus and M. pneumoniae (a previously unrecognized association).

AIDS-Related Opportunistic Infections↗
PubMed1997

Plasmid diversity in Chlamydia.

Chlamydiae exhibit low interspecies DNA homology and plasmids from different chlamydial species can be readily distinguished by Southern blot analysis and restriction enzyme profiling. In contrast, available plasmid sequence data from within the species Chlamydia trachomatis indicate that plasmids from human isolates are highly conserved. To evaluate the nature and extent of plasmid variation, the complete nucleotide sequences were determined for novel plasmids from three diverse non-human chlamydial isolates: pCpA1 from avian Chlamydia psittaci (N352); pCpnE1 from equine Chlamydia pneumoniae (N16); and pMoPn from C. trachomatis mouse pneumonitis. Comparison of the sequence data did not identify an overall biological function for the plasmid but did reveal considerable sequence conservation (> 60%) and a remarkably consistent genomic arrangement comprising eight major ORFs and four 22 bp tandem repeats. The plasmid sequences were close to 7500 nucleotides in length (pCpA1, 7553 bp; pMoPn, 7502 bp) however the equine C. pneumoniae plasmid was smaller (7362 bp) than all other chlamydial plasmids. The reduced size of this plasmid was due to a single large deletion occurring within ORF 1; this potentially generates two smaller ORFs. The disruption of ORF 1 is the only significant variation identified amongst the chlamydial plasmids and could prove important for future vector development studies.

Amino Acid Sequence↗
PubMed1997

Polymerase chain reaction for detection of Chlamydia trachomatis in conjunctival swabs.

AIMS/BACKGROUND: Ocular Chlamydia trachomatis infection in the west occurs as opthalmia neonatorum, acquired from the mother, or adult paratrachoma which is also associated with current genital tract infection. Accurate rapid laboratory diagnosis facilitates management, but the relative merits of antigen detection or DNA amplification tests are unresolved. METHODS: A polymerase chain reaction (PCR) test was developed which amplified part of the plasmid shared by all the serovars of C trachomatis. Conjunctival swabs were tested using an in house immune dot-blot test (IDBT) for chlamydial lipopolysaccharide antigen, a commercial direct fluorescent antibody (DFA) test for chlamydial elementary bodies, and the PCR (DNA extracted using guanidinium lysis buffer). RESULTS: The PCR achieved a detection limit of 100 plasmid copies (10 elementary bodies). In a combined retrospective and prospective clinical evaluation, the PCR and IDBT gave identical results with 21 positive and 57 negative eye swabs. However, interpretation of the DFA test required meticulous examination of the stained smear, sometimes by two microscopists. CONCLUSIONS: The PCR is likely to play an increasing role in the diagnosis of ocular C trachomatis infection because of its excellent sensitivity and specificity.

Adult↗
PubMed1994

Lipopolysaccharide in cells infected by Chlamydia trachomatis.

In view of the controversy concerning the expression of chlamydial lipopolysaccharide (LPS) in the eukaryotic host cell, the presence of this molecule was examined in three cell types which were experimentally infected with Chlamydia trachomatis serotype E. LPS was detected in the McCoy cell line, human endometrial epithelium and human amniotic epithelium with two monoclonal antibodies. The appearance and distribution of LPS at the host cell surface during the chlamydial developmental cycle and its transmission to neighbouring cells were examined by immunofluorescence microscopy after air drying of the host cells. LPS distribution was not uniform; it was first observed on regions of the cell surface in close proximity to the chlamydial endosome (inclusion). Soon after, the antigen was also detected at points of contact with neighbouring uninfected cells. Immunofluorescent plaques of host cells contaminated with LPS were thus formed in the vicinity of infected cells. These plaques increased in size over 2 d before becoming smaller as host cell lysis occurred. The major outer-membrane protein (MOMP) was not visualized on the host cell surface after air drying. No cell-surface LPS antigen was observed in live cells or those fixed in formaldehyde without air drying. Conventional methanol fixation and immunolocalization of LPS and MOMP in parallel infected cultures stained these antigens within inclusions in the expected fashion. Radio-immunoassays were used to quantify LPS in confluent McCoy cell monolayers during the chlamydial developmental cycle. Cell-surface-associated and inclusion-associated LPS, measured by direct binding of 125I-labelled anti-LPS monoclonal antibodies to air-dried or methanol-fixed monolayers respectively, increased for up to 3 d then declined.(ABSTRACT TRUNCATED AT 250 WORDS)

Amnion↗
PubMed1989

Analysis of the complete nucleotide sequence of Chp1, a phage which infects avian Chlamydia psittaci.

We report the complete nucleotide sequence of bacteriophage Chp1. The genome was found to be 4877 bases long and it potentially codes for 11 proteins. Open reading frames (ORFs) 6 and 7 lie within ORFs 2 and 1 respectively but are in a second reading frame. No significant DNA homology was found when Chp1 was compared to the EMBL database. The N-terminal amino acid sequences of the three structural proteins VP1, VP2 and VP3 were determined and it was found that they were encoded by ORFs 1, 2 and 3 respectively. Amino acid homology studies revealed that VP1 has homology with the major structural protein of bacteriophages phi X174 and S13, and that the protein inferred from ORF 4 shows homology to the A proteins of phi X174, S13 and G4. The genome of Chp1 has an organization similar to that of phi X174 although it is 509 bases smaller. We propose that Chp1 is a member of the Microviridae but that it is sufficiently different to warrant its own subfamily which we have called the Chlamydiavirinae.

Amino Acid Sequence↗
PubMed1989

Further characterization of a bacteriophage recovered from an avian strain of Chlamydia psittaci.

The genome of a 22 nm icosahedral phage which infects some avian Chlamydia psittaci strains recovered from domestic ducks has been characterized as a ss circular DNA molecule of about 4850 bases. The replicative form of this genome was isolated from purified chlamydial organisms. A restriction endonuclease cleavage site map of the genome was constructed from dsDNA synthesized in vitro from ss phage DNA and EcoRI fragments were then cloned into pUC9. The phage genome was detected only by Southern blot hybridization in C. psittaci which was productively infected with phage; no evidence was found for the integration of phage DNA into the chlamydial chromosome. Three viral polypeptides, of approximate Mr values 75K, 30K and 16.5K were identified when phage was analysed by SDS-PAGE. This virus, which we have designated Chp 1, is either an aberrant member of the Microviridae or the first member of a new bacteriophage family.

Animals↗
PubMed1989

Plasmid diversity within the genus Chlamydia.

Examination of 12 Chlamydia psittaci strains recovered from nine different host species (three avian and six mammalian) revealed the presence of a 7.5 kb plasmid in all isolates except two ovine abortion strains, the human strain IOL207 and the Cal 10 strain. Restriction mapping analysis distinguished four different plasmids that were associated with avian, feline, equine and guinea-pig C. psittaci isolates, respectively. The restriction maps of these four C. psittaci plasmid types all differed from that of the plasmid recovered from C. trachomatis L2/434. Despite this plasmid diversity, which is likely to be of taxonomic importance, all four plasmids identified within the species C. psittaci were found to share some sequence homology, which was mapped to two separate regions in the plasmid molecules. One region, which showed a high degree of homology between C. psittaci plasmids and also detectable homology with the C. trachomatis plasmid, may represent a common replication control region for plasmids of this genus.

Animals↗
PubMed1988

Sensitive immune dot blot test for diagnosis of Chlamydia trachomatis infection.

The sensitivity and specificity of an immune dot blot test (IDBT), which relies on a 125I-labeled genus-specific monoclonal antibody to detect the Chlamydia lipopolysaccharide (LPS) antigen, were improved by pretreatment of specimens with proteinase K. This enzyme destroys protein A and therefore eliminates false-positive reactions caused by the presence of Staphylococcus aureus. Proteinase K treatment also improved the ability of the assay to detect the Chlamydia LPS antigen. When the improved IDBT was compared with culture for detection of C. trachomatis in 1,394 urogenital specimens obtained from a genitourinary medicine clinic, the overall sensitivity was 96%, and LPS antigen was detected in 76 of 83 (92%) specimens that yielded less than 10 inclusions in culture. The specificity and positive and negative predictive values of the test were 97, 81.5, and 99%, respectively. Of 123 conjunctival swabs, 7 were positive by both tests and 4 swabs were positive only by IDBT. This improved IDBT provides a simple, reliable alternative to culture for the detection of C. trachomatis in urogenital and conjunctival specimens.

Adult↗
PubMed1987

Immune dot blot technique for diagnosing infection with Chlamydia trachomatis.

An immune dot blot test (IDBT) to detect the genus specific lipopolysaccharide chlamydial antigen is described, in which the antigen is trapped on nitrocellulose membrane and then detected with a monoclonal antibody labelled with 125iodine. A preliminary comparison of 270 specimens obtained from the endocervix or male urethra showed that the IDBT was more sensitive (sensitivity 90%) than a commercial amplified enzyme immunoassay named IDEIA (sensitivity (60%) for detecting specimens that yielded Chlamydia trachomatis on culture. Subsequent assessment of 950 urogenital tract specimens in the IDBT and by culture confirmed the sensitivity (92%) and specificity (95%) of the IDBT. At least one of 56 specimens obtained from the eye, however, gave a false positive result, which was probably due to staphylococcal protein A in the specimen. The IDBT provides the basis for a novel simple test for detecting the genus Chlamydia.

Antibodies, Monoclonal↗