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Y Aujard

Publications and source records attributed to Y Aujard.

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

Molecular analysis of multiply recurrent meningitis due to Escherichia coli K1 in an infant.

Bacterial DNA polymorphism was used to document the occurrence of three separate episodes of meningitis caused by Escherichia coli K1 in an infant. The methods employed included determination of the restriction fragment length polymorphism of total DNA and of ribosomal DNA regions as well as DNA fingerprinting by the arbitrarily primed polymerase chain reaction. By these three genotypic approaches, the three isolates obtained from the infant's cerebrospinal fluid on days 9, 34, and 70, respectively, were found to share the same patterns, which were different from the patterns of control strains. Thus, these three episodes of E. coli K1 meningitis were due to a single strain. DNA-based typing techniques seem extremely promising as tools to be used in unraveling the complex mechanisms of recurrent meningitis.

DNA, Bacterial↗
PubMed1992

Mother-to-infant vertical transmission and cross-colonization of Streptococcus pyogenes confirmed by DNA restriction fragment length polymorphism analysis.

Restriction fragment length polymorphism (RFLP) analysis of total DNA and of ribosomal DNA (rDNA) regions (ribotyping) were used to document Streptococcus pyogenes vertical mother-to-infant transmission and to investigate the spread of S. pyogenes in an obstetric unit. Two isolates from a newborn, two isolates from his mother (patient 1), and two isolates from two other mothers (patients 2 and 3) were studied. RFLP of total DNA, both after HindIII and PvuII digestions and ethidium bromide staining, gave indistinguishable patterns for the strains isolated from the neonate, his mother, and patient 2. Strains from patient 3 and six unrelated strains studied for comparison showed different patterns. In our system, ribotyping was less discriminative than total DNA RFLP analysis. DNA RFLP analysis therefore provides a valuable molecular tool for studying S. pyogenes epidemiology.

Adult↗
PubMed1992

Analysis of DNA restriction fragment length polymorphism extends the evidence for breast milk transmission in Streptococcus agalactiae late-onset neonatal infection.

Analysis of restriction fragment length polymorphism (RFLP) of total DNA and of ribosomal DNA (ribotyping) was used to document four cases of Streptococcus agalactiae mother-to-infant transmission potentially associated with ingestion of infected mother's milk. Twenty strains were analyzed. Ten strains were mother-baby pairs, five from the milk of five mothers, four from their neonates with late-onset infection, and one from a colonized neonate. All mothers had early postpartum mastitis. Ten unrelated strains were studied for comparison. In each case, the two strains of each mother-baby pair produced identical RFLP patterns of total DNA. The 10 unrelated strains generated 10 different patterns, one of which, though, was observed in one of the mother-baby pairs. Ribotyping was less discriminative than total DNA RFLP analysis (6 different patterns vs. 13). These data extend the evidence for breast milk transmission in S. agalactiae late-onset neonatal infection.

Breast Feeding↗
PubMed1992

Bactericidal activity of beta-lactams and amikacin against Haemophilus influenzae: effect on endotoxin release.

Ampicillin or cefotaxime, alone or in combination with amikacin, were tested at levels achievable in CSF for bactericidal activity against eight clinical isolates of Haemophilus influenzae serotype b. Endotoxin release was determined by the limulus amoebocyte lysate test and by macrophage tumour necrosis factor production for each beta-lactam antibiotic, alone and in combination with amikacin. Accelerated killing was observed when amikacin was added to ampicillin or cefotaxime; however, the additional antibiotic-induced bacterial lysis observed after the addition of amikacin to beta-lactam antibiotics was not associated with an increase in endotoxin release.

Amikacin↗
PubMed1992

Ribotyping provides efficient differentiation of nosocomial Serratia marcescens isolates in a pediatric hospital.

Ribotyping with a nonradioactive probing system was used for the epidemiological evaluation of 15 Serratia marcescens nosocomial strains isolated from the stools of 12 children with no apparent illness in five different hospital wards over a 20-day period. Our results indicate that the occurrence of S. marcescens colonization was the result of the spread of a single epidemiological strain in the hematology ward, the oncology ward, and the gastroenterology ward and in two neonates in the neonatology ward, suggesting cross-contamination between the patients in these four wards. This isolate was genotypically unrelated to the bacterial strain found in the three other patients in the neonatology ward. Interestingly, one patient in the neonatology ward harbored these two genotypically different strains. Finally, the patient in the intensive care unit was colonized with a different strain. We find ribotyping to be a more reliable technique than biochemical typing. The results of ribotyping are more easily interpreted than are those of total DNA analysis, with an equivalent degree of discrimination.

Bacterial Typing Techniques↗
PubMed1992

Comparison of T cell functional changes during childhood with the ontogeny of CDw29 and CD45RA expression on CD4+ T cells.

The ontogeny of the peripheral blood mononuclear cells' responsiveness to various activators during childhood was studied and compared to the expression of CDw29 and CD45RA molecules at the surface of CD4+ T cells. The results show that newborn peripheral blood mononuclear cells are characterized by a responsiveness to mitogens that is higher than that observed in adults, at least shortly after stimulation. This contrasts with a clear decreased response to CD2 and CD3 MAb at any time after stimulation. These functional characteristics correlate with a low density of CDw29 antigen on virtually all CD4+ T cells and a high density of CD45RA antigen on most CD4+ T cells at birth. These patterns of reactivity and phenotype are similar to those found among naive adult T cells. When ageing, the response to mitogens becomes rapidly similar to the adult's values, whereas the responses to CD2 or CD3 MAb are more gradually acquired. This slow rate of functional changes grossly parallels the increase of CDw29+ CD4+ and the decrease of CD45RA+ CD4+ T cell subsets. These changes finally lead to the immunophenotypic and functional characteristics that are typical of adult memory T cells. These results suggest that iterative antigenic stimulations both induce memory T cells and create the conditions to improve the overall immune competence.

Adolescent↗
PubMed1991

[Primary and secondary neonatal negative coagulase staphylococcus infections].

As a rule, coagulase-negative staphylococcal infections in the neonate is an acquired iatrogenic infection. It usually occurs in premature infants with an in-dwelling catheter. Clinical and laboratory criteria are used to differentiate contaminated samplings from true infection. the frequency of methicillin-resistant strains justifies the use of vancomycin combined with an aminoglycoside and, in the first days, with rifampicin, all drugs administered in doses calculated for the post-conception age. This treatment is also administered in mother-to-foetus infections caused by CNS.

Anti-Bacterial Agents↗
PubMed1991

[Antibiotic therapy in maternal-fetal infections].

The selection of first-line antimicrobial therapy in neonates with maternofetal infection is based on probability data from epidemiologic studies of bacterial infections. Because of the high prevalence of ampicillin-resistant E. coli strains and of the lack of susceptibility of Listeria and group D streptococci to cephalosporins, combined use of two complementary drugs, such as amoxicillin and cefotaxime with an aminoglycoside, is recommended. Each dose should be increased twofold in patients with meningeal involvement. The interval between aminoglycoside doses depends on the degree of renal maturity and therefore on gestational age. Discontinuation of treatment on the third day when clinical and biologic monitoring disproves the suspected infection avoids the occurrence of untoward effects, especially on the intestinal flora. In other cases, administration of two drugs selected on the basis of bacteriologic findings is needed beyond the third day. Specific therapy is required in infrequent infections (Candida, tuberculosis, syphilis, Helicobacter). The dosage of antimicrobials with narrow therapeutic margins (vancomycin, aminoglycosides) should be adjusted on the basis of serum assays performed at four-day intervals. Duration of therapy is usually ten days but may reach 21 days in neonates with meningitis. Prevention, in the absence of specific vaccines, rests on antenatal and perinatal treatment of women at high risk for infection. Management of neonates with group B streptococcal infection is controversial; close clinical and biologic monitoring over 48 hours may allow to reduce the use of antimicrobials.

Anti-Bacterial Agents↗
PubMed1990

Bacterial counts in cerebrospinal fluid of children with meningitis.

Eighty-five cerebrospinal fluid (CSF) specimens from the same number of pediatric patients with meningitis were examined to determine the bacterial count and the relationship of this count to the microscopy results, the ages of the patients and the bacterial species isolated. Bacterial counts ranged from 2 x 10 to 4 x 10(9) CFU/ml CSF. Twenty-five percent of the 85 CSF specimens positive for Haemophilus influenzae type b, Neisseria meningitidis, Streptococcus pneumoniae, Escherichia coli K1 and group B streptococci had counts of 10(7) CFU/ml or higher. Children between 1 and 6 months of age had significantly higher counts (p less than 0.05) than the other age groups. The three patients who had positive CSF cultures 24 h after the start of therapy all had initial bacterial counts of 10(7) CFU/ml or higher. The detection limit for Gram stain/microscopy was 10(5) CFU/ml. No correlation was found between bacterial count and the number of polymorphonuclear leukocytes.

Age Factors↗