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Biomedical subjects

D Corsaro

Publications and source records attributed to D Corsaro.

10 recordsLinked to original sources
PubMed2001

Infection due to acyclovir resistant herpes simplex virus in patients undergoing allogeneic hematopoietic stem cell transplantation.

Over an eight-month period from October 1997 to May 1998, four patients who had received bone marrow transplant (BMT) from unrelated donor presented with severe mucosal cutaneous infections involving acyclovir resistant herpes simplex virus 1 (HSV-1). The four isolates were acyclovir (ACV) resistant, three of which were also foscarnet resistant as determined by the dye uptake method. The sequencing of the thymidine kinase (TK) gene did not permit to establish a relation between mutations and resistance to ACV. Three patients were considered as clinically cured of their HSV infection by replacement of ACV or foscarnet with either valacyclovir (one case) or cidofovir (two cases) but eventually two of them died of graft vs host disease. One patient died of extensive HSV infection despite administration of cidofovir. This study emphasizes the importance of monitoring the herpes virus resistance to antiviral drugs in bone marrow transplant recipients and the usefulness of the evaluation of novel antiviral drug for treatment of infections due to strains of HSV resistant to ACV and foscarnet that occur in about 5% of immunocompromised patients.

Acute Disease↗
PubMed2001

Comparison of sludge and clinical isolates of Listeria monocytogenes.

AIMS: Listeria monocytogenes strains isolated in the same geographical area from sewage sludge and from patients presenting with listeriosis were compared. METHODS AND RESULTS: All isolates were typed by serotyping, phage typing and SmaI/ApaI pulsed-field gel electrophoresis (PFGE). Among the sludge isolates (n=32), 22 subtypes could be distinguished by the combination of all typing methods. The human isolates (n=11) were distributed into 10 subtypes which clearly differed from those observed among sludge isolates, except for one cluster formed by two related human isolates which showed high similarity in PFGE patterns (SmaI: 92%; ApaI: 89.5%) with one sludge isolate. CONCLUSION: These results suggest the existence of an epidemiological link between sludge and human isolates, but they may also be reflecting the distribution of L. monocytogenes types within the environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Sludge and human L. monocytogenes may be related but further epidemiological studies are necessary to elucidate this point.

Bacterial Typing Techniques↗
PubMed2001

Investigation of aciclovir-resistant herpes simplex virus I infection in a bone marrow transplantation unit: genotyping shows that different strains are involved.

Over an eight-month period from October 1997 to May 1998, four patients who had received a bone marrow transplant (BMT) from an unrelated donor presented with severe mucosal cutaneous infections involving aciclovir resistant herpes simplex virus 1 (HSV-1). The emergence within a short period of resistant HSV-1 strains in the bone marrow transplantation unit raised fears of hospital-acquired infections. The hypothesis was investigated by restriction fragment length polymorphism (RFLP), sequencing of the thymidine kinase (TK) gene and genotyping of hypervariable regions of these four strains. Restriction fragment length polymorphism proved to be poorly discriminant and the TK sequence did not rule out transmission between these patients. Amplification of reiterating hypervariable genomic HSV-1 regions designated Re IV and Re VII clearly differentiated patients' strains. Thus, in this study, there was no evidence of nosocomial transmission of HSV-1 strains between the four patients.

Acyclovir↗
PubMed2000

Hepatitis B virus X gene variability in French-born patients with chronic hepatitis and hepatocellular carcinoma.

The polymorphism of the hepatitis B virus (HBV) X gene from patients born in Lorraine has been studied in serum samples from 22 HBV infected patients, 14 presenting with chronic hepatitis and 8 with hepatocellular carcinoma (HCC). Subtypes adw and ayw represented 21 of the 22 sequenced isolates. The sequence of the X gene of HBV strains from these patients differed from the ones of Far East origin by A to T(1678) and G to A(1759) changes for subtype ayw and C to T(1792) for adw. The expression of the preC region, as indicated by the detection of HBe antigen (HBeAg), was not observed in 11 patients. In 6 patients (3 HCC and 3 non HCC), the absence of HBeAg could be related to a stop codon at position 28. For the 5 remaining patients, the precore stop mutation at codon 28 was not evidenced but 3 out these 5 patients had mutations at nt 1764 and nt 1766 in the promoter of the preC/C gene. These two mutations were also observed in 2 patients with HBeAg, indicating that they are not implicated in the suppression of expression of this gene. Independently of the serotype, two main differences were noted between aminoacid (aa) sequences of chronic hepatitis and HCC related strains: first, twice as many aa changes were found in HCC patients than in chronic hepatitis B carriers (mean of aa changes per patient 4.1 vs. 2.0) and second, we found apparition of polar aa in HCC patients. Most mutations already described in patients from the Far East with HCC have been found in strains of patients from Lorraine. The changes K130M and V131I, considered as "hot spot mutations," were found in strains of HCC patients carrying an ayw subtype of the HBV genome but not in the ones of chronically infected patients. In contrast, strains of the adw subtype had these two changes in the two groups of patients. However when considering the 22 sequenced genes, these hot spot mutations were associated with HCC (P = 0.034).

Adolescent↗
PubMed2000

Genotyping of adenoviruses isolated in an outbreak in a bone marrow transplant unit shows that diverse strains are involved.

In the Bone Marrow Transplant Unit of the "Centre Hospitalier Universitaire" in Nancy, from October 1995 to May 1996, 13 patients of 65 (20%) had a positive adenovirus (Ad) culture after bone marrow transplant. This unusually high rate raised fears of nosocomial spread and so isolates were serotyped. Fourteen Ad strains were isolated from the 13 patients, nine were of serotype 1, 2 or 3, and 5 were non-typable. These five latter strains were responsible for four cases of severe infection with fatal outcome within a two-month period. They were further submitted to restriction fragment length polymorphism analysis of their DNA which showed the isolates differed by a percentage similarity of 8-79%. In this outbreak, different strains were involved, and there was no evidence of a nosocomial origin of Ad infection.

Adenovirus Infections, Human↗
PubMed1999

Multiplex PCR for rapid and differential diagnosis of Mycoplasma pneumoniae and Chlamydia pneumoniae in respiratory infections.

A duplex polymerase chain reaction (PCR) was developed for the simultaneous detection of Chlamydia pneumoniae and Mycoplasma pneumoniae. A study of 163 respiratory specimens from in-patients of the "Centre Hospitalier et Universitaire de Nancy" showed the good sensitivity of this duplex PCR allowing the detection of C. pneumoniae and M. pneumoniae from 8 and 13 patients, respectively, whereas the culture was negative for C. pneumoniae for all the samples and positive for M. pneumoniae only in 9 cases. The value of these results has been confirmed by running on the same samples specific nested PCRs for these two microorganisms that gave the same results. Thus, the proposed duplex amplification technique may facilitate the diagnosis of infection by these two agents that are difficult to isolate.

Adolescent↗
PubMed1999

Intracellular life.

Intracellular parasites and endosymbionts are present in almost all forms of life, including bacteria. Some eukaryotic organelles are believed to be derived from ancestral endosymbionts. Parasites and symbionts show several adaptations to intracellular life. A comparative analysis of their biology suggests some general considerations involved in adapting to intracellular life and reveals a number of independently achieved strategies for the exploitation of an intracellular habitat. Symbioses mainly based on a form of syntrophy may have led to the establishment of unique physiological systems. Generally, a symbiont can be considered to be an attenuated pathogen. The combination of morphological studies, molecular phylogenetic analyses, and palaeobiological data has led to considerable improvement in the understanding of intracellular life evolution. Comparing host and symbiont phylogenies could lead to an explanation of the evolutionary history of symbiosis. These studies also provide strong evidences for the endosymbiogenesis of the eukaryotic cell. Indeed, an eubacterial origin for mitochondria and plastids is well accepted and is suggested for other organelles. The expansion of intracellular living associations is presented, with a particular emphasis on peculiar aspects and/or recent data, providing a global evaluation.

Animals↗
PubMed1999

Molecular epidemiology of ocular isolates of adenovirus 8 obtained over nine years.

Twenty nine strains of adenovirus 8 have been isolated over nine years in Strasbourg, France, 22 of which were from one private ophthalmologist. To assess a possible relation between these strains, the DNA of adenovirus was analysed by restriction fragment length polymorphism using eight different enzymes. Among these, three proved discriminant (Xba I, Bgl II, Eco RI) and made it possible to define 13 genotypes differing from each other by one to three DNA bands. Seven genotypes were unique isolates, while three, representing 16 strains, were isolated over five to eight years. All the genotypes but one were closely related, with 87% homology. All 13 differed from an adenovirus 8 strain from Lyon (homology 68-76%). This study confirmed the stability of adenovirus 8 in a given population.

Adenoviridae↗
PubMed1995

Detection by multiplex polymerase chain reaction and typing of Chlamydia trachomatis isolates.

The multiplex polymerase chain reaction (PCR) was applied for the detection of the Chlamydia trachomatis chromosome and plasmid. The multiplex PCR demonstrated a sensitivity of 0.8 fg of chlamydial DNA, corresponding to the detection of about 5 copies of the plasmid. Analysis of 195 genital specimens collected randomly from a female population, showed that the multiplex PCR is more sensitive and rapid than culturing for detecting Chlamydia trachomatis. Moreover, sequencing of the II variable domain of the omp1 gene, directly from DNA of the clinical specimens, appears to be a simple and rapid method for determining serovar isolates.

Bacterial Typing Techniques↗