Biomedical subjects

Thierry Lambert

Publications and source records attributed to Thierry Lambert.

22 records · Page 2Linked to original sources

PubMed2002

Distribution of extended-spectrum beta-lactamases in clinical isolates of Enterobacteriaceae in Vietnam.

Among 730 Escherichia coli, 438 Klebsiella pneumoniae, and 141 Proteus mirabilis isolates obtained between September 2000 and September 2001 in seven hospitals in Ho Chi Minh City, Vietnam, 26.6% were resistant to ceftazidime, 30% were resistant to cefotaxime, 31.5% were resistant to ceftriaxone, 15.9% were resistant to cefoperazone, and 6% were resistant to cefepime. Resistance to imipenem was found in 5.6% of the isolates. In 55 strains producing extended-spectrum beta-lactamases (32 E. coli isolates, 13 K. pneumoniae isolates, and 10 P. mirabilis isolates), structural genes for VEB-1 (25.5%), CTX-M (25.5%), SHV (38.1%), and TEM (76.3%) enzymes were detected alone or in combination. Sequencing of the PCR products obtained from the K. pneumoniae isolates revealed the presence of bla(VEB-1), bla(CTX-M-14), bla(CTX-M-17), bla(SHV-2), and bla(TEM-1). Molecular typing of the strains with a similar resistance phenotype to broad-spectrum cephalosporins indicated polyclonal spread. ISEcp1 was presumably responsible for dissemination of the bla(CTX-M-like) gene.

Anti-Bacterial Agents↗

PubMed2002

ColE1-like plasmid pIP843 of Klebsiella pneumoniae encoding extended-spectrum beta-lactamase CTX-M-17.

The resistance of Klebsiella pneumoniae BM4493, isolated in Ho Chi Minh City, Vietnam, to cefotaxime and aztreonam was due to production of a novel beta-lactamase, CTX-M-17. The bla(CTX-M-17) gene was borne by 7,086-bp plasmid pIP843, which was entirely sequenced and which was found to belong to the ColE1 family. The 876-bp bla(CTX-M-17) gene differed from bla(CTX-M-14) by 2 nucleotides, which led to the single amino acid substitution Glu289-->Lys. bla(CTX-M-17) was flanked upstream by an ISEcp1-like element and downstream by an insertion sequence (IS) IS903 variant designated IS903-C. The transcriptional start site of bla(CTX-M-17) was located 109 nucleotides upstream from the initiation codon in the ISEcp1-like element, which also provided the promoter sequences. Plasmid pIP843, which was non-self-transferable and nonmobilizable, contained five open reading frames transcribed in the same orientation. Regions homologous to sequences coding for putative RNA II and RNA I transcripts, a rom gene, which is involved in initiation of replication, and a cer-like gene, which is responsible for the stability of ColE1-like plasmids, were identified. Consensus sequences for putative replication (oriV) and transfer (oriT) origins were present. Results of primer extension experiments indicated that ISEcp1 provides the promoter for expression of bla(CTX-M-17) and may contribute to dissemination of this gene.

Anti-Bacterial Agents↗

PubMed2002

Native valve endocarditis due to Enterococcus hirae.

Enterococcus hirae is a rare isolate in clinical specimens. We describe a case of native aortic-valve endocarditis that was caused by Enterococcus hirae in a 72-year-old man. This is the first reported case of endocarditis due to this organism.

Aged↗

PubMedDate not supplied

Reappraisal of in utero stem cell transplantation based on long-term results.

The therapeutic field of in utero transplantation of stem cells, into human fetuses, has developed since 1988 with the hope of improved probability of engraftment and tolerance, due to immune immaturity of the host. Fifteen years later, it is possible to evaluate the results that we and others have obtained in the treatment of several fetal diseases. Seven fetal patients have been treated in Lyon: In 2 cases, pregnancy termination was induced by the in utero injection; in the 5 other cases, engraftment was obtained and repeatedly documented with presence of donor HLA antigens and/or Y chromosome in recipients. In the 2 patients with combined immunodeficiency disease, a sustained reconstitution of immunity was obtained as a result of the transplant but other complications occurred thereafter. In patients with thalassemia major, Niemann-Pick disease or hemophilia, a very partial and very transitory benefit was only obtained. Approximately 33 other patients with immunodeficiencies, hemoglobinopathies or inborn errors of metabolism have been treated worldwide, over the last 13 years, with a comparable method, using parental or fetal stem cells transplanted in utero. Successful treatment has usually been recorded in immunodeficiencies, and insufficient results have been obtained in the other cases. This form of treatment can therefore be recommended after prenatal diagnosis of combined immunodeficiency but additional research is required to improve the degree of engraftment, the lack of resistance of the host and the 'space' available for hematopoiesis in the other conditions.

Animals↗