Biomedical subjects

Manuela Donati

Publications and source records attributed to Manuela Donati.

4 recordsLinked to original sources

PubMed2003

DNA immunization with pgp3 gene of Chlamydia trachomatis inhibits the spread of chlamydial infection from the lower to the upper genital tract in C3H/HeN mice.

Chlamydia trachomatis pgp3 DNA immunized (no. 300) and non-immunized (no. 300) C3H/HeN mice were infected by vaginal inoculation with infectious C. trachomatis serotype D elementary bodies (EBs) and the spread of infection to the salpinges was assessed by cell culture isolation from tissue homogenates 7, 14, 21, 28, 35 and 42 days post-infection (p.i.). Overall, the pgp3-DNA immunization prevented salpinx infection in 94 (56%) mice, if compared with the 168 positive animals found among the non-immunized animals (P < 0.001). A group of negative control animals (i.e. mice immunized with plasmid DNA containing an irrelevant insert) was not protected, whereas all the mice of a positive immune control group (mice that had resolved a primary genital C. trachomatis infection) were resistant to re-infection. Pgp3 DNA immunization induced both humoral and mucosal anti-pgp3 antibodies.

Animals↗

PubMed2002

Chlamydia trachomatis - the agent.

Chlamydiae are obligate intracellular bacteria, parasitizing eukaryotic cells. Chlamydia trachomatis, C. psittaci and C. pneumoniae are the three species of chlamydiae pathogenic to humans. C. trachomatis shows a tropism for the genital and conjunctival epithelia and consists of 19 different serovars which are pathogenic predominantly for the urogenital tract.A distinguishing feature of chlamydiae is their transition between the infectious elementary body that enters the host cell and the non-infectious reticulate body that replicates intracellularly within an inclusion that does not fuse with lysosomes. Chlamydiae depend for some functions upon the host cell; in particular, chlamydiae have little capacity for generating energy. The complete sequence of the 1000-kb chromosome of C. trachomatis is known, as are most of the genes located on the 7.5-kb cryptic plasmid. Recently, several concepts about the biology and the metabolic pathways of C. trachomatis have been revised in relation to the genome sequence, and different novel proteins have been described.

Chlamydia Infections↗

PubMed2002

Genomic approach for analysis of surface proteins in Chlamydia pneumoniae.

Chlamydia pneumoniae, a human pathogen causing respiratory infections and probably contributing to the development of atherosclerosis and heart disease, is an obligate intracellular parasite which for replication needs to productively interact with and enter human cells. Because of the intrinsic difficulty in working with C. pneumoniae and in the absence of reliable tools for its genetic manipulation, the molecular definition of the chlamydial cell surface is still limited, thus leaving the mechanisms of chlamydial entry largely unknown. In an effort to define the surface protein organization of C. pneumoniae, we have adopted a combined genomic-proteomic approach based on (i) in silico prediction from the available genome sequences of peripherally located proteins, (ii) heterologous expression and purification of selected proteins, (iii) production of mouse immune sera against the recombinant proteins to be used in Western blotting and fluorescence-activated cell sorter (FACS) analyses for the identification of surface antigens, and (iv) mass spectrometry analysis of two-dimensional electrophoresis (2DE) maps of chlamydial protein extracts to confirm the presence of the FACS-positive antigens in the chlamydial cell. Of the 53 FACS-positive sera, 41 recognized a protein species with the expected size on Western blots, and 28 of the 53 antigens shown to be surface-exposed by FACS were identified on 2DE maps of elementary-body extracts. This work represents the first systematic attempt to define surface protein organization in C. pneumoniae.

Animals↗

PubMed1996

Use of the ligase chain reaction on urine of men and their female sexual partners for detection of genital Chlamydia trachomatis infection.

OBJECTIVE: The purpose of the present study was to evaluate an in vitro DNA amplification assay named the ligase chain reaction (LCR) for the detection of Chlamydia trachomatis cryptic plasmid DNA in urine from men and women, in comparison with urethral swab culture in men and cervical swab culture in women. METHODS: 591 patients (394 men with urethritis and 197 female sex partners) attending a center for sexually transmitted diseases in northern Italy between January 1994 and January 1995 were enrolled in this study. A cervical swab was collected from women and a urethral swab from men for standard tissue cell culture. From each patient 20 mL of the first stream of the urine (FVU), taken at least 2 h after the last urination, were collected for LCR analysis. Discrepant results were further analyzed by direct fluorescence and a LCR with alternative primers. RESULTS: In men the prevalence of C. trachomatis infection by urethral culture was 13.45% and, after resolution of discordant results, the LCR method performed on FVU showed a sensitivity, specificity, positive predictive value and negative predictive value of 89.4%, 100%, 100% and 98.2%, respectively; the sensitivity of tissue cell culture was 92.8%. In female sex partners, the prevalence of C. trachomatis infection by cervical culture was 3.04%; LCR detected eight true positive samples, two more than tissue cell culture, and no false-negative results. CONCLUSION: LCR analysis of FVU is a rapid, non-invasive technique and represents a good alternative to tissue cell culture. Further study is needed to investigate possible LCR inhibitors present in urine samples.

Journal Article↗