[Acute severe leukoencephalitis with posterior lesions due to Borrelia burgdorferi infection]. / Leuco-encéphalite aiguë à tropisme postérieur révélant précocement une maladie de Lyme.

INTRODUCTION: Central nervous system manifestations represent 0.54 to 8% of neurological complication in Lyme disease. OBSERVATION: A 78-year-old woman presented a severe meningo-encephalitis with visual disorders (agnosia, alexia) progressing towards coma. Cranial magnetic resonance imaging revealed large areas of hypersignal T2 in the white matter of the lower, parieto-occipital lobes and left temporal lobe. The cerebrospinal fluid (CSF) contained 16 then 293 white corpuscles/mm3 of lympho-monocytes, increased protein level from 2.67 to 5.83 g/l and an increase in IgG index with oligoclonal distribution of IgG. Serological Elisa analysis for Lyme disease was slightly positive in blood (confirmed by western blot) but clearly in the CSF (IgG and IgM). Treatment with ceftriaxone followed by methylprednisolone provided clinical improvement 3 months later. DISCUSSION: Acute meningo-encephalitis is often benign, protein-like and of good prognosis: the gnosic visual disorders with posterior leukoencephalopathy are unusual. A blood level of specific antibodies slightly positive on Elisa at the early stage of the infection warrants confirmation by Western blot in the blood and by Elisa in the CSF. Additional corticosteroid therapy may be required in the severe forms that evoke acute disseminated encephalomyelitis.

Malignant boutonneuse fever and polymyalgia rheumatica: a coincidental association?

Mediterranean spotted fever is a tick-borne disease that is endemic in the Mediterranean basin from spring to autumn. Usually mild, the disease can be severe in some cases, especially when risk factors are encountered in patients or when treatment is delayed. The correlation between these malignant forms and patients' immunological disorders remains unclear, while the pathophysiology of the disease seems well known. A case of a malignant form of Mediterranean spotted fever is reported which occurred 2 months prior to the diagnosis of polymyalgia rheumatica. Evidence of immunological disorders consisted only in an antiphospholipid antibody associated with a transient lupus anticoagulant. No underlying risk factors other than the primary undiagnosed phase of polymyalgia rheumatica has been observed.

Measurement by the polymerase chain reaction of the Epstein-Barr virus load in infectious mononucleosis and AIDS-related non-Hodgkin's lymphomas.

A polymerase chain reaction (PCR) assay for the detection of Epstein-Barr virus (EBV) sequences in various clinical samples, especially peripheral blood leukocytes (PBL) and serum, was carried out and the results obtained were compared with specific EBV serology. One hundred seventy patients were enrolled in the study: 89 healthy blood donors, 22 asymptomatic patients, 36 individuals with primary EBV infection (including 19 patients with infectious mononucleosis [IM]), 22 HIV-infected subjects (including 4 with hairy oral leukoplakia, 3 with central nervous disorders, and 15 with non-Hodgkin's lymphoma). All the serum samples from the healthy blood donors were negative. In patients with IM and in AIDS-non Hodgkin's lymphoma (ARNHL), PCR was strongly positive in leukocytes (> 2,000 genome equivalents/10(4) cells), which was correlated with detectable amounts of EBV DNA in serum. The overall positivity rate of PCR in serum was 58.8%, 68%, and 73% of cases for non-IM primary EBV infections, IM, and ARNHL, respectively. In two cases of EBV primary infection, the viral DNA was detected in serum, respectively 1 month and 2 months before IgM positivity and IgG rise. In one case of ARNHL followed up for several months, PCR (viral load of 2,000 genome equivalents/10(4) cells) became positive concurrently with appearance of lymphoma. In immunocompromised individuals, PCR EBV, if carried out in larger prospective studies, could be considered as a tumor marker, useful for predicting EBV-driven lymphoma and follow-up therapy.

rRNA gene restriction patterns of Streptococcus pyogenes: epidemiological applications and relation to serotypes.

The use of rRNA gene restriction fragment length polymorphism analysis (ribotyping) to subtype Streptococcus pyogenes strains was investigated. Sixty-eight S. pyogenes strains, including 17 reference strains and 51 isolates from blood, acute or chronic pharyngitis, and food-borne outbreaks, were characterized by determination of both their rDNA restriction fragment length polymorphism profiles and their serotypes (T and M). Total DNA was cleaved with five selected restriction enzymes and then probed with a digoxigenin-labeled stretch of 1,063 bp hybridizing with 16S rRNA genes. Fifteen and nine distinct patterns were generated with SacI and XhoI, respectively, and five patterns were generated with each of the three additional restriction enzymes. With the combination SacI-XhoI, a total of 21 distinct ribotypes were obtained among the 68 isolates. This number was not increased by the results obtained with the other restriction enzymes. All strains tested were typeable. All isolates from each food-borne outbreak belonged to the same ribotype, and all isolates (pre- and posttreatment) from each child with chronic pharyngitis also belonged to the same ribotype, suggesting antibiotic treatment failures. A discriminatory index was calculated for the 47 isolates which were epidemiologically unrelated, using the Hunter-Gaston formula. This index reached 0.955 when the combination SacI-XhoI was used, showing the good discriminatory power of this typing method. Therefore, ribotyping proved to be a molecular method of interest to subtype S. pyogenes. Moreover, there was some correlation between ribotyping and serotyping, as several ribotypes were related to a unique distinct M serotype.

Discrimination of Mycobacterium avium-Mycobacterium intracellulare strains by genomic DNA fingerprinting with a 16S rRNA gene probe.

Ribotyping was investigated as a means of distinguishing ten different serotyped reference strains and seven epidemiologically unrelated isolates of Mycobacterium avium-Mycobacterium intracellulare using a labelled 16S rDNA probe. Thirteen restriction enzymes were screened towards an accurate discrimination of strains. Two selected restriction enzymes (SacI and ClaI) enabled us to classify the 17 strains into ten ribotypes with an index of discrimination of 0.897. Typeability and reproducibility of the method reached 100%. The patterns obtained exhibited polymorphism of RE fragments within and outside the 16S rRNA gene and may be useful for epidemiological studies.

Use of monoclonal antibodies to distinguish pathogenic Naegleria fowleri (cysts, trophozoites, or flagellate forms) from other Naegleria species.

Monoclonal antibodies (MAbs) reactive to the pathogenic amoeba Naegleria fowleri were analyzed by enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay, Western blotting (immunoblotting), and radioimmunoprecipitation assay (RIPA). Two MAbs (3A4 and 5D12) showed reactivity by ELISA with all N. fowleri strains tested and no reactivity with the five other Naegleria species, N. lovaniensis, N. gruberi, N. australiensis, N. jadini, and N. andersoni. These MAbs reacted with the three morphological forms of N. fowleri (trophozoites, cysts, and flagellates). The reactivity on Western blots was suppressed by treatment with metaperiodate, suggesting a carbohydrate epitope. Differences in reactivity patterns between trophozoites and cysts observed with radioimmunoprecipitation assay might reflect differences in biological properties. The formalin stability of the epitope may be useful in detecting N. fowleri in fixed biopsies and in investigating the pathological process.

Diagnostic value of amplification of human cytomegalovirus DNA from gastrointestinal biopsies from human immunodeficiency virus-infected patients.

In order to assess the value of human cytomegalovirus (HCMV) DNA amplification of gastrointestinal biopsies, we studied 57 human immunodeficiency virus-infected patients with and without gastrointestinal HCMV diseases. After DNA extraction, a 406-bp fragment from the unique short region of the HCMV genome was amplified by 35 cycles of polymerase chain reaction (PCR) and semiquantified from 80 to 80,000 HCMV genomic copies. Among 12 non-AIDS patients, the PCR assay was negative for 11 of 12 duodenal and 8 of 8 colorectal samples. It was also negative for 28 of 31 duodenal and 12 of 15 colorectal samples from 31 AIDS patients without gastrointestinal HCMV diseases. Among 14 AIDS patients with gastrointestinal HCMV diseases, the PCR assay was positive for 12 of 12 patients with HCMV duodenitis and for 13 of 13 patients with HCMV colitis. Results were dichotomized between high and low HCMV-DNA copy numbers. For duodenitis, sensitivity was 92% and specificity was 100%. For colitis, sensitivity was 92% and specificity was 93%. Specificity and sensitivity were not influenced by shedding status for HCMV or by other gastrointestinal infections. HCMV DNA amplification of gastrointestinal biopsies is a sensitive and specific tool for the diagnosis of gastrointestinal HCMV diseases in AIDS patients.

Partial characterization of an external polysaccharide of Helicobacter pylori by using an immunoglobulin M monoclonal antibody.

A monoclonal immunoglobulin M antibody, HP15/36, was produced by a hybridoma cell line prepared by fusion of mouse myeloma cell line Sp2/O with spleen cells of mice immunized with Helicobacter pylori D273 (French strain). Immunoelectron microscopy of whole bacteria and ultrathin sections showed that the determinant was located outside the bacterial cell, possibly in the outermost areas. This external reactivity was observed by immunofluorescence and immunoperoxidase assays and was confirmed by immunogold study at the ultrastructural level. The reactive epitope was formol and picric acid resistant and allowed the detection of the bacterium on fixed tissue biopsy specimens. The reactive component was extracted with phenol-water. Immunoblotting with such an antigen exhibited a clearly positive reactivity at a molecular mass between 50 and 120 kDa. This reactivity was suppressed by periodate oxidation, suggesting a carbohydrate epitope. The diagnostic value and significance of this polysaccharide in microbe-host interactions remain to be determined.

Demonstration of lectin-like activity for the common antigen of Neisseria gonorrhoeae by quantitative immunoelectrophoretic techniques.

To overcome problems associated with Western blotting of denatured proteins, we have used quantitative immunoelectrophoretic techniques to perform functional analysis of the Neisseria gonorrhoeae common antigen. Using these techniques, we show (a) that Neisseria gonorrhoeae expresses an antigen that is cross-reactive with the common antigen of Pseudomonas aeruginosa and Legionella micdadei and with the GroEl-like protein of Chlamydia, and (b) that this N. gonorrhoeae common antigen has lectin-like activity and can be precipitated with three different sugars immobilized on agarose beads: alpha-D-glucosamine, maltose and fucose.

Diversity of Mobiluncus strains as demonstrated by their electrophoretic protein patterns.

The analysis of electrophoretic protein profiles of 21 Mobiluncus curtisii, 11 Mobiluncus mulieris and 3 reference strains (Mobiluncus curtisii subsp. curtisii ATCC 35241, Mobiluncus curtisii subsp. holmesii ATCC 35242 and Mobiluncus mulieris BV 64-5) demonstrated species-related patterns. A highly variable region appeared at 70-85 kDa for Mobiluncus curtisii and at 75-95 kDa for Mobiluncus mulieris, which was likely to correspond to cell surface located proteins. When performed under standardized conditions, PAGE-protein analysis allowed to define intraspecies clusters, from which some strains appeared identical. Thus, the method seemed to provide a useful additive to identify a strain at the species level and might be of epidemiological interest.

Characterization of an immunoreactive species-specific 19-kilodalton outer membrane protein from Helicobacter pylori by using a monoclonal antibody.

Immunoblotting experiments on hyperimmune rabbit serum and sera from patients with Helicobacter pylori gastritis showed a consistent antibody response to a 19-kDa outer membrane protein antigen. A monoclonal antibody, designated HP 40, which reacted by Western immunoblotting with this protein was produced. It was shared by all H. pylori strains tested (D 273, NCTC 11637, and 24 wild strains) but not by the thermophilic Campylobacter species, Campylobacter fetus, Helicobacter mustellae, or Helicobacter fennelliae. Immunogold staining suggested that the 19-kDa antigen was exposed on the outer surface of the bacteria. Its functional role and effectiveness as a serological diagnostic tool are under study.

[The diagnosis of genital papillomavirus infections using molecular hybridization]. / Diagnostic des infections génitales à papillomavirus par hybridation moléculaire.

Human papillomaviruses (HPV) are non-cultivable, small ADN viruses, of which about sixty different types are known at present. They infect specifically the stratified epithelium and are responsible for skin lesions (warts) and mucous lesions (condylomata). Their presence can probably be associated with the possible development of genital neoplasia. They cannot be detected by culture and it is at present impossible to reveal their presence by specific antigens. However, the presence of their genome in the infected cells can be detected by hybridization with the use of marked nucleic probes, Southern-blot (method of reference), dot-blot, quicker but less specific, or hybridization in situ which enables the assessment of the histopathological environment. Finally, the very sensitive technique of enzymatic amplification of the genes (Polymerase Chain Reaction-PCR) could become a method of choice for the detection of HPV. These techniques of molecular biology have shown that genital HPV infections are widely spread, but the markers necessary to determine the risk of neoplastic degeneration are yet to be discovered.

Distribution of Haemophilus influenzae and Haemophilus parainfluenzae biotypes isolated from the human genitourinary tract.

A total of 3,598 genital specimens from men and women was cultured for Haemophilus spp. using a simple selective culture method. Two hundred and thirty three samples (6.5%) were positive for Haemophilus spp., 216 Haemophilus parainfluenzae and 28 Haemophilus influenzae strains being isolated. Biotyping demonstrated that Haemophilus parainfluenzae biotype II was dominant at all sites, especially the male urethra, comprising 59% of all Haemophilus strains isolated. On the other hand, Haemophilus influenzae biotype IV was isolated from only six patients and thus was not a major genital biotype. The respective proportions of the two Haemophilus spp. recovered from various mucosal sites led to the supposition that the genitourinary colonization originated either from the upper respiratory tract or the gastrointestinal tract.

Use of monoclonal antibodies for rapid detection of influenza A virus in nasopharyngeal secretions.

Two monoclonal antibodies against influenza A virus were assessed for use as diagnostic reagents in an indirect immunofluorescence assay (IFA) of nasopharyngeal secretions. Monoclonal antibody IA-52, directed at an internal antigen, reacted with all influenza A tested. The high stability of this epitope permitted its use in a rapid IFA test, which gave results comparable to those obtained with polyclonal antibodies and viral isolation. The second monoclonal antibody, IA-279 was directed at a surface epitope (hemagglutinin); it reacted with almost all H3 subtype strains. Positive IFA using these monoclonal antibodies permitted rapid preliminary differentiation between the current two major subtypes of influenza A virus (H1N1, H3N2).

[Acquired neonatal herpes]. / Herpès néonatal acquis.

The authors report a case of neonatal herpes simplex infection with favourable outcome, without any sign of meningo-encephalitis or dissemination. The child was given antiviral treatment with Acyclovir from the first day of rash. Vesicle scraping and a complete serologic study of both child and mother proved infection was due to herpes simplex virus type I, transmitted to the neonate during primary maternal infection with gingivostomatitis beginning on the day of delivery. The different routes of postnatal contamination of the neonate by herpes virus and the risks of dissemination are reviewed. The importance of preventing contamination and dissemination of a known herpetic infection in maternity-hospitals and in nurseries for newborns is emphasized. Antiviral treatment should be used in all neonates with localized herpetic infection.