Search PubMed⌕ Search

Biomedical subjects

C Chastel

Publications and source records attributed to C Chastel.

At least 37 records · Page 2Linked to original sources
PubMed1998

Spiroplasma turonicum sp. nov. from Haematopota horse flies (Diptera: Tabanidae) in France.

Strain Tab4cT, a helical prokaryote that was isolated from the body of a Haematopota sp. fly collected in Champchevrier, Indre-et-Loire, Touraine, France, was found to be a member of the class Mollicutes. The cells of strain Tab4cT were small, motile helices that were devoid of a cell wall. The organism passed through filters with mean pore diameters as small as 0.20 mm. Strain Tab4cT grew rapidly in liquid SP-4 medium at both 30 and 37 degrees C. The organism fermented glucose but did not hydrolyse arginine or urea, and did not require serum for growth. In preliminary electrophoretic analyses, the cell protein patterns of strain Tab4cT were distinct from those of 14 other spiroplasmas found in mosquitoes, deer flies and horse flies from Europe and the Far-East. In reciprocal metabolism inhibition and deformation serological tests, employing antigens and antisera representative of spiroplasma groups I-XXXIII (including all sub-groups), plus ungrouped strains BARC 1901 and BARC 2649, no serological relationship with Tab4cT was found. The G + C content of the DNA of strain Tab4cT was about 25 +/- 1 mol% and its genome size was 1.305 kbp. It is proposed that spiroplasma strain Tab4cT be assigned to group XVII (presently vacant) and that strain (ATCC 700271T) is the type strain of a new species, Spiroplasma turonicum.

Animals↗
PubMed1998

[Cutaneous lesions, viral risk and marine bird ticks, a world wide problem; apropos of 1 case with pseudo-zoster lesions].

Dermatological injuries provoked by tick bites deserve more attention. The authors present the clinical observation of a young woman bitten in Brittany by the marine bird associated tick Ornithodoros (A.) maritimus and presenting pseudo-zoster skin lesions. Two other individuals working together with the patient and also bitten by this tick showed symptoms of prurigo, fever and vomiting. Marine bird associated ticks bites may also be responsible for the inoculation of a number of arboviruses along all the coasts of the world including those of islands of Indian Ocean. Pathogenesis of the skin lesions is discussed according to the authors' histo-pathological findings.

Adult↗
PubMed1998

[Erve and Eyach: two viruses isolated in France, neuropathogenic for man and widely distributed in Western Europe].

Two arboviruses have been isolated from Mayenne, western France, in 1981-1982, during systematic field surveys: Eyach virus, a cultivirus from Ixodes ricinus and I. ventalloi ticks, and Erve virus, a nairovirus from the tissues of white-toothed shrews, Crocidura russula. For many years, these two viruses were considered as "orphan viruses" without pathogenic power for man, since it became evident that they circulate actively in Europe among populations of wild small and large mammals. Moreover, these viruses are able to infect human beings and were responsible for severe neurological disorders. The presently known geographical distribution of these agents includes France, Germany, Netherlands and Czech Republic.

Coltivirus↗
PubMed1997

[Collecting with the flagging method and fixing on man of Ixodes (Trichotoixodes) frontalis (Panzer, 1795)].

As he was beginning to sort a batch of Ixodid ticks, collected with the flagging technique, the operator noticed that a female tick identified as Ixodes frontalis had fixed itself rapidly on the top of one of his finger. That species is usually considered as "strict-specific to birds". The low frequency of such a fixing on human beings, as for as we know, is of limited value from an epidemiological point of view.

Animals↗
PubMed1997

Three spiroplasmas isolated from Haematopota sp. (Diptera:Tabanidae) in France.

On August 1991, three spiroplasmas (Tab 2A, Tab 2B and Tab 4C) were isolated from Haematopota sp. flies collected from Indre-et-Loire, France. Isolations were made at 28 degrees C in MD1 medium from ground individual flies, but not from external washings. All isolates adapted well to SP4 medium at 30 and 37 degrees C and were triple cloned before serological identification. Using the cross deformation test, the 3 isolates were compared with 42 known spiroplasmas isolated from diseased plants, flowers, various insects and ticks belonging to 25 serological groups. Each isolate cross-reacted with others and exhibited weak 1-way reactions with TABS-2 or PLHS-1, two spiroplasmas isolated in the United States from respectively Tabanus abactor Philip and Panorpa helena L, a scorpion-fly. These results suggest that Tab 2A, Tab 2B and Tab 4C together with TABS-2 and PLHS-1 may represent, members of a new serological supergroup.

Animals↗
PubMed1996

Serological and molecular characterization of Mesoplasma seiffertii strains isolated from hematophagous dipterans in France.

Three strains of nonhelical mollicutes previously isolated in France from two different mosquitoes and one tabanid fly were designated strains Ar 2328 (isolated from Aedes detritus), Ar 2392 (isolated from Aedes caspius), and CP 13 (isolated from Chrysops pictus). All of these strains exhibited properties of the genus Mesoplasma, a recently described genus of non-sterol-requiring mollicutes isolated from plants and insects. The results of metabolism inhibition and growth inhibition tests revealed that these strains and Mesoplasma entomophilum TAC or Mesoplasma florum L1 were not serologically related, but all three dipteran strains reacted strongly with Mesoplasma seiffertii F7T (T = type strain) antibodies. Using metabolism inhibition and growth inhibition tests, we found that the dipteran strains were related to each other and to strain F7T but were not identical. We also found that they were able to multiply and persist in the central nervous systems of suckling mice inoculated intracerebrally, a property that makes their use as biological control agents for pest dipterans inadvisable. Scanning electron microscopy revealed marked differences in the morphologies of the colonies of the different strains on SP4 solid medium. The levels of DNA-DNA homology for strains Ar 2328, Ar 2392, CP 13, and F7T were more than 70%, indicating that these strains are closely related members of the same species, M. seiffertii. In addition, one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that each strain produced about 40 protein bands. This technique also revealed differences between strains. Using the coefficient of Smeath-Jacquart, we constructed a dendrogram that allowed us to estimate of the levels of relatedness of these four strains. The results which we obtained were confirmed by two-dimensional protein electrophoresis results.

Aedes↗
PubMed1996

[Argas and arbovirus update].

At the opportunity of the recent discovery of a new Phlebovirus, Tunis virus, the authors discuss the importance of the genus Argas as for its potential role in the transmission of arboviruses: twelve species of Argas are known to carry about twenty viruses. The wide distribution of Argas reflexes hermanni prompt us to explain its position in the Argas reflexes "complex" group: this species seems to be more liable to infection by viruses. Some ecological and entomological data are added to facilitate its typing. The Tunisian specimens recollected are remarkable by the lack of seta n degree 5 on basis capituli.

Animals↗
PubMed1995

Links and interactions between mycoplasmas and viruses: past confusions and present realities.

Links between mycoplasmas and viruses are ancient, multiple and complex, from past confusions during the first decades of the virus era to present realities illustrated by the possible implication of mycoplasmas as co-factors in natural infections of AIDS. Mycoplasma viruses (phages) may also be responsible for modifying the pathogenic power of mycoplasmas, at least for plants and insects. In addition, several mycoplasmas are able to act as undesirable cell culture contaminants that induce erroneous results in both applied and general virology. These problems are examined within a historical context.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Neonatal nosocomial respiratory infection with coronavirus: a prospective study in a neonatal intensive care unit.

The aim of this prospective study was to evaluate the incidence of viral respiratory infection in hospitalized premature newborn infants and to assess the role of coronaviruses. All hospitalized premature infants with a gestational age less than or equal to 32 weeks were included. Tracheal or nasopharyngal specimens were studied by immunofluorescence for coronaviruses, respiratory syncytial virus, adenoviruses, influenza and parainfluenza viruses. Forty premature infants were included; 13 samples were positive in 10 newborns (coronaviruses n = 10; influenza 1 n = 2; adenovirus n = 1). None was positive at admission. All premature infants infected with coronaviruses had symptoms of bradycardia, apnea, hypoxemia, fever or abdominal distension. Chest X-ray revealed diffuse infiltrates in two cases. However, no significant difference was observed between infected and non-infected premature infants for gestational age, birth weight, duration of ventilation, age at discharge, incidence of apnea or bradycardia. Nosocomial respiratory tract infection with coronaviruses appears to be frequent. The clinical consequences should be evaluated in a larger population.

Body Fluids↗
PubMed1995

[Tick-transmitted arbovirus in Maghreb].

The problem of arbovirus infections in Maghreb has been relatively neglected in the pst in spite of a rich diversity of biotopes, the presence of potential reservoirs and vectors, and their position on the flight path of the Palearctic-african bird migration systems, western branch. Moreover, West Nile virus has been isolated from southern Algeria since 1968. From 1979 to 1989, ticks were collected from wild birds, pigeons, bats, rodents, poultry, camels, wild boars, domestic mammals and man, and assayed for viruses. On the whole, 424 ticks were virologically studied from Morocco, 582 from Algeria and 601 from Tunisia. Four tick-borne arboviruses have been isolated so far: three from Morocco, Soldado (Nairovirus), Essaouria (Orbivirus) and Kala Iris (Orbivirus) from Ornithodoros (A.) maritimus ticks parasitizing marine birds, and one from Tunisia, Tunis (Phlebovirus), from Argas reflexus hermanni infesting domestic pigeons. Soldado virus may infect man working into colonies of gulls for ornithological or entomological purposes and this infection is associated with a self-limited febrile illness and pruritus. In addition, antibody to Essaouira virus was detected in a wild rodent in Morocco. On the contrary it is unlike that Tunis virus may infect man because A. r. hermanni is a strickly ornithophilic tick. However, Uukuniemi group antibody has been previously evidenced in wild rodents in Tunisia. Finally, it is not excluded that other, more pathogenic, arboviruses such as Congo-Crimean haemorrhagic fever might be accidentally introduced in this sensitive geographical area.

Africa, Northern↗
PubMed1994

Lack of relationship between the Epstein-Barr virus and the antiperinuclear factor/'perinuclear antigen' system in rheumatoid arthritis.

Our purpose was to evaluate the role of Epstein-Barr virus (EBV) in the production of antiperinuclear factor (APF), a rheumatoid arthritis (RA)-specific marker, and the autoimmunogenicity of 'perinuclear antigens' (PNA) found within the buccal mucosa epithelial cells used as a substrate in the APF assay. Fifty APF-positive and 50 APF-negative sera from RA patients were examined for the presence of antibodies to six different EBV antigens. APF was tested in the serum of 40 patients with acute infectious mononucleosis (IM), 48 PNA-expressing donors and 29 non-PNA-expressing donors. The EBV genome was sought in the saliva and buccal cells of both types of donors. The targeted granules of cells from a PNA-expressing donor were studied by electron-microscopy. The prevalence of anti-EBV antibodies was similar in RA patients with and without APF, whereas the APF-positive sera was elevated in acute IM. The titres of anti-EBV antibodies did not correlate to the expression of PNA in the buccal cells of the donors. There was no relationship between this expression and the presence of the EBV genome in the material obtained from 'positive' donors, relative to 'negative' donors. No virus-like particles could be detected inside the granules by electron microscopy. These results indicate that there are no direct relationships between EBV and the APF/PNA system, although APF was present in a number of patients with IM.

Adult↗
PubMed1994

Tunis virus: a new Phlebovirus from Argas reflexus hermanni ticks in Tunisia.

A new Phlebovirus provisionally named Tunis virus has been isolated from Argas reflexus hermanni ticks parasitizing domestic pigeons. It is the first isolation of an arbovirus from Tunisia and the fourth tick-borne virus to be isolated from the Moghreb following Soldado, Essaouira and Kala Iris in Morocco. The pathogenic potential of this virus is briefly discussed according to the behaviour of its vector and previous serosurveys in the country.

Animals↗