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T Lambert

Publications and source records attributed to T Lambert.

At least 73 records · Page 4Linked to original sources
PubMed1993

Characterization of Acinetobacter haemolyticus aac(6')-Ig gene encoding an aminoglycoside 6'-N-acetyltransferase which modifies amikacin.

The amikacin resistance gene acc(6')-Ig of Acinetobacter haemolyticus BM2685 encoding an aminoglycoside 6'-N-acetyltransferase was characterized. The gene was identified as a coding sequence of 438 bp corresponding to a protein with a calculated mass of 16,522 Da. Analysis of the deduced amino acid sequence suggested that it was the fourth member of a subfamily of aminoglycoside 6'-N-acetyltransferases. The resistance gene was not transferable either by conjugation to Escherichia coli or to Acinetobacter baumannii or by transformation into Acinetobacter calcoaceticus. Plasmid DNA from strain BM2685 did not hybridize with an intragenic aac(6')-Ig probe. These results suggest a chromosomal location for this gene. The gene was detected by DNA hybridization in all 20 strains of A. haemolyticus tested but not in 179 other Acinetobacter strains, including A. baumannii, A. lwoffii, A. junii, and A. johnsonii and genospecies 3, 6, 11, 13, 14, 15, 16, and 17, of which 162 were amikacin resistant. The probe did not hybridize in dot blot assays with DNAs purified from members of the families Enterobacteriaceae and Pseudomonadaceae that encode 6'-N-acetyltransferases. These data suggest that the aac(6')-Ig gene is species specific and may be used to identify A. haemolyticus.

Acetyltransferases↗
PubMed1993

Characterization of the aac(6')-Ib gene encoding an aminoglycoside 6'-N-acetyltransferase in Pseudomonas aeruginosa BM2656.

Pseudomonas aeruginosa BM2656 was resistant to tobramycin and susceptible to gentamicin and amikacin by disk diffusion testing. This unusual resistance was not transferable by conjugation to Escherichia coli or P. aeruginosa PAO38, and plasmid DNA was not detected in this strain. A 0.9-kb fragment harboring the tobramycin resistance gene was cloned from BM2656 into pUC18, generating pAT129. Analysis for aminoglycoside-modifying activity in extracts of BM2656 and E. coli harboring pAT129 indicated that tobramycin resistance was due to synthesis of an aminoglycoside 6'-N-acetyltransferase type I [AAC(6')-I] enzyme which modified amikacin and tobramycin. Although amikacin was acetylated, the bactericidal synergism of this aminoglycoside with ceftazidime against BM2656 was minimally affected. The sequence of the DNA fragment was determined. It contained an aac (6')-Ib-like gene and was located downstream from a conserved region related to Tn21. The translated sequence of this aac(6')-Ib gene possessed 99.2% identity with the putative products of the aac(6')-Ib gene cassettes from Serratia marcescens and Klebsiella pneumoniae and 69% identity with the putative aacA(6')-II gene product from P. aeruginosa. We conclude that an aac(6')-Ib gene has spread to the chromosome of P. aeruginosa, probably by transposition.

Acetyltransferases↗
PubMed1993

Comparison of two molecular methods for tracing nosocomial transmission of Escherichia coli K1 in a neonatal unit.

Escherichia coli K1, a normal inhabitant of the human flora, is also an important cause of serious infections in newborns. We compared two molecular methods, ribotyping and arbitrarily primed polymerase chain reaction (AP-PCR), to study the apparent nosocomial transmission of an E. coli K1 clone in a nursery for premature neonates. Sixty-two E. coli K1 strains isolated from 41 premature neonates from December 1991 to June 1992 and six strains isolated from ambient sources were studied. Eight E. coli K1 strains isolated from infants in the nursery between 1989 and September 1991 were included as controls. The properties of the strains isolated between December 1991 and June 1992 were as follows: 43 belonged to ribotype I, 12 belonged to ribotype III, and the remaining 13 isolates were distributed among 10 ribotypes. The eight control strains belonged to seven different ribotypes, but none was ribotype I. Between December 1991 and February 1992, the majority of strains from premature infants colonized with E. coli K1 were of ribotype I. Isolates from the ventilation system and from a storage shelf were also of ribotype I. When DNA from 56 selected strains was tested by AP-PCR by using the 5'-TTGTAAAACGACGGCCAG-3' oligonucleotide, 15 different profiles were obtained. Twenty-five of 56 strains were of ribotype I and had identical profiles by AP-PCR. Strains with ribotypes VI, VII, and X to XV had different profiles by AP-PCR. We conclude that ribotyping and AP-PCR correlate well and permit demonstration of the nosocomial dissemination of E. coli K1 in a unit for premature neonates.

Bacterial Typing Techniques↗
PubMed1990

Dissemination of amikacin resistance gene aphA6 in Acinetobacter spp.

The distribution of the aphA6 gene, encoding a 3'-aminoglycoside phosphotransferase type VI, was studied by dot blot hybridization with 115 amikacin-resistant Acinetobacter strains from various geographical areas. Nucleotide sequences related to aphA6 were found in 109 strains belonging to seven species. As inferred from results of Southern hybridization, dissemination of amikacin resistance in Acinetobacter spp. is due to a gene rather than a strain or plasmid epidemic.

Acinetobacter↗
PubMed1989

[The main characteristics of blood products in current use].

More than 30 different preparations or presentations of human blood derivatives are now available for therapeutic use. Each of then complies with precise standards. In this article, the various characteristics of these blood products (collection, constituents, preservation, mode of use, cost) are reviewed. The products are classified according to their biological type and therapeutic field.

Blood Coagulation Factors↗
PubMed1988

Pregnancy and paroxysmal nocturnal hemoglobinuria.

Our study concerns eight pregnancies, six of which were successful, in four patients with paroxysmal nocturnal hemoglobinuria (PNH). Several complications of PNH during pregnancy were prevented: chronic anemia, folate and iron deficiency, and deep-vein thrombosis. During puerperium, acute hemolytic crises, most probably triggered by delivery, were observed in two patients. Thrombotic complications could be prevented by early initiation of an anticoagulant therapy after delivery. The only neonatal complication, observed in two cases, was isoimmune hemolytic anemia related to the multiple blood transfusions received before and during pregnancy. These results show that successful pregnancies are possible in women with PNH provided that both the obstetricians and physicians in charge monitor the pregnancies closely.

Adult↗
PubMed1988

Transferable amikacin resistance in Acinetobacter spp. due to a new type of 3'-aminoglycoside phosphotransferase.

Acinetobacter baumannii BM2580 resistant to kanamycin and structurally related antibiotics, including amikacin, was isolated from a clinical specimen. A phosphocellulose paper-binding assay and DNA annealing studies indicated that resistance to aminoglycosides in BM2580 was due to synthesis of a new type of 3'-aminoglycoside phosphotransferase. The gene conferring resistance to kanamycin-amikacin in this strain was carried by a 63-kilobase plasmid, pIP1841, self-transferable to A. baumannii, A. haemolyticus, and A. lwoffii but not to Escherichia coli. The aminoglycoside resistance gene of pIP1841 was cloned in E. coli, where it was expressed.

Acinetobacter↗
PubMed1988

[Use of imipenem-cilastatin in neonatal septicemias caused by gram-negative bacilli multiresistant to beta-lactam antibiotics].

Seven neonates with septicemia due to Gram negative bacteria resistant to beta-lactam received imipenem-cilastatin therapy. Bacteria isolated were Enterobacter cloacae [3], Enterobacter aerogenes [1], Klebsiella pneumoniae [1], Serratia marcescens [1], Pseudomonas fluorescens [1]. The MICs of imipenem were lower 1 microgram/ml. In 3 children septicemia occurred during previous antimicrobial chemotherapy. 3 IV 60 mg/kg doses of imipenem with amikacin (15 mg kg/d) were administered every day. For five children blood cultures were negative after 48 hours of treatment. E. aerogenes septicemia required pefloxacin because blood cultures remained positive (d5) despite an increased dosage (90 mg/kg/d). All children were cured and imipenem-cilastatin was not responsible for any complication. Those results demonstrate the efficacy of imipenem in the treatment of septicemia in newborns due to multiresistant Gram negative bacteria.

Anti-Bacterial Agents↗
PubMed1987

Acquisition by a Campylobacter-like strain of aphA-1, a kanamycin resistance determinant from members of the family Enterobacteriaceae.

A Campylobacter-like organism, BM2196, resistant to kanamycin and streptomycin-spectinomycin was isolated from the feces of a patient with acute enteritis. The kanamycin and streptomycin-spectinomycin resistances were not transferable to Camplylobacter sp. or to Escherichia coli, and no plasmid DNA was detected in this strain. The resistance genes were therefore tentatively assigned to a chromosomal locality. Analysis by the phosphocellulose paper-binding assay of extracts from BM2196 indicated that resistance to kanamycin and structurally related antibiotics was due to the synthesis of 3'-aminoglycoside phosphotransferase type I [APH(3')-I], an enzyme specific for gram-negative bacteria, and that resistance to streptomycin-spectinomycin was secondary to the presence of a 3",9-aminoglycoside adenylyltransferase. Homology between BM2196 and an APH(3')-I probe was detected by DNA-DNA hybridization. A 2.2-kilobase BM2196 DNA fragment conferring resistance to kanamycin was cloned in E. coli and was sequenced partially. The resistance gene appeared nearly identical to that of Tn903 from E. coli and was adjacent to IS15-delta, an insertion sequence widespread in gram-negative bacteria, thus indicating that Campylobacter species can act as a recipient for genes originating in members of the family Enterobacteriaceae.

Base Composition↗
PubMed1987

[Impact of hemophilia on the psychomotor development of children].

A psychomotor assessment was performed in a population of 26 severe hemophilic children aged 4 to 12 y. This assessment studied the coordination and the rhythm, the gestual symbolization and the drawing of the self-portrait. Results were compared to those of an age-matched group of 26 non-hemophilic healthy boys. This study revealed a high frequency of moderate psychomotor abnormalities in hemophiliacs. The presence of these abnormalities was not correlated with the degree of arthropathy, the frequency of bleeding or the treatment regimen, on demand or prophylaxis. The results of the psychomotor assessment should be taken into account in the management of children with hemophilia. It may also enable the family to become aware of the impact of its own attitude facing hemophilia.

Child↗
PubMed1987

Synovectomy of the elbow in young hemophilic patients.

Synovectomy of twenty-three elbows was done in eighteen patients, eight to twenty-five years old, who had severe hemophilia and were followed for eighteen to seventy months. Episodes of bleeding recurred in four elbows, and moderate pain persisted in three. A significant improvement in mobility was observed for pronation-supination in nine elbows and for flexion-extension in fourteen. No radiographic evidence of arthritis was seen. Synovectomy of the elbow, performed through a single lateral incision, appears to be a valuable surgical procedure in hemophiliacs in whom non-operative treatment has failed, and resection of the radial head should be done in adults when there is moderate or severe damage to the cartilage of the radial head.

Adolescent↗
PubMed1986

Susceptibility of Campylobacter pyloridis to 20 antimicrobial agents.

The susceptibility of 50 strains of Campylobacter pyloridis, isolated from human gastric biopsies, to 20 antimicrobial agents representing the different families of antibiotics was tested. The pattern of susceptibility was similar to that of the C. jejuni-C. coli group except for ampicillin, cephalothin, and rifampin. The relative resistance to cefsulodin was also noted.

Anti-Bacterial Agents↗
PubMed1985

In vivo transfer of genetic information between gram-positive and gram-negative bacteria.

A 1427-bp DNA fragment containing the kanamycin resistance gene, aphA-3, of plasmid pIP1433 from Campylobacter coli was inserted into a shuttle vector. Full expression of aphA-3 was obtained in Bacillus subtilis and in Escherichia coli. This DNA fragment was sequenced in its entirety and the starting point for aphA-3 transcription in B. subtilis, C. coli and E. coli was determined by S1 nuclease mapping. The sequence of the promoter consists of the hexanucleotides TTGACA and TATAAT, with a spacing of 17 bp. The nucleotide sequence of the aphA-3 gene from C. coli and from the streptococcal plasmid pJH1 are identical whereas they differ by two substitutions and deletion of a codon from that cloned from the staphylococcal plasmid pSH2. These results indicate a recent extension of the resistant gene pool of Gram-positive cocci to Gram-negative bacilli. From an analysis of the DNA sequences surrounding the promoter region, we concluded that the DNA fragment containing the aphA-3 gene in plasmid pJH1 has evolved by deletions from a sequence similar to that found in plasmid pIP1433.

Bacillus subtilis↗