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Biomedical subjects

M Guibert

Publications and source records attributed to M Guibert.

At least 19 recordsLinked to original sources
PubMed2001

Unusual etiology of visual loss in an HIV-infected patient due to endogenous endophthalmitis.

Disseminated candidiasis, especially ocular infections such as endophthalmitis, is uncommon in HIV-infected patients. We report a case of candidal endophthalmitis in an HIV-positive non-drug-user patient, following candidemia from a cutaneous abscess at the site of a peripheral catheter. Ocular disease was revealed by a visual decrease in the left eye. DNA analysis using RAPD showed identical patterns of Candida albicans isolated from the skin and eye. Combination therapy with high-dose fluconazole and intravenous amphotericin B was performed. Two intravitreal amphotericin B injections and a vitrectomy were administered because of an amblyopic right eye and severe vitritis. The outcome was favorable without relapse at 18 months.

AIDS-Related Opportunistic Infections↗
PubMed2000

Acute pancreatitis caused by severe Legionella pneumophila infection.

We report three cases of severe community-acquired Legionella pneumophila pneumonia with acute pancreatitis. Pancreas involvement is unusual. The clinical presentations consisted of painless pancreatitis with only elevation of serum pancreatic enzymes (case 1), tender abdomen with edematous pancreas on computed tomography scan (case 2) and necrosis (case 3). We discuss the possible mechanisms of L. pneumophila associated acute pancreatitis for which the pathophysiology is still undetermined: infection, toxin release or cytokine secretion.

Acute Disease↗
PubMed2000

Maternal-fetal staphylococcal infections: a series report.

The objective of this paper is to study the characteristics of maternal-fetal staphyloccocal infection. A retrospective study among 1,582 infants admitted consecutively to our neonatal intensive care unit was carried out from January 1995 through September 1998. The antenatal history, and the clinical and bacteriological findings and outcome of the infants fulfilling maternal-fetal staphyloccocal infection were analysed. Among 122 (7.7%) maternal-fetal infection, 11 cases (8.9%) of congenital staphyloccal infections were diagnosed in 9 premature and 2 full-term babies. Antenatal invasive procedures were noted in 6 occasions (56%). All the 11 infants developed respiratory and hemodynamic failure. Staphylococcus aureus was the most common organism encountered in maternal bacteriologic data (9/11, 82%) as well as on peripheral sites (9/11, 82%) and in blood cultures (7/11, 64%) performed in the infants. There was one case of methicillin-resistant Staphylococcus aureus. The outcome was favorable for 9 infants. Two very preterm neonates died within the first 72 hours of life. Mother-to-infant transmission of Staphylococcus should be suspected whenever invasive procedures are performed during pregnancy and in the presence of severe neonatal distress associated with an inflammatory response. Prompt and adapted antibiotic therapy allows a favourable outcome.

Amniocentesis↗
PubMed1999

Microbiology in sudden infant death syndrome (SIDS) and other childhood deaths.

The usefulness of post-mortem microbiology in the assessment of sudden unexpected deaths in infants and children has been debated by many pathologists. In our centre, microbiological investigations have been part of the post-mortem protocol for investigation of sudden deaths in infants and children for the past 12 years. The objective of this study was to review the microbiological findings for infants and children examined by our unit during the past 4 years in relation to gross and histological findings of the autopsy and the medical and social histories of the children. We reviewed 57 consecutive sudden deaths in infants and children examined by our Referral Centre between November 1994 and October 1998. These 57 sudden deaths were aged from 1 day to 4 years and 9 months including 40 cases of sudden infant death syndrome (SIDS) and 17 non-SIDS deaths. Results of the microbiological investigations of tissues and body fluids were assessed during the case review with reference to histological shock signs, severe gastric aspiration, and signs of acute thymic involution. Bacteria alone or in association with viruses were identified in 45/57 (79%) cases including 34/40 (85%) SIDS. The most frequent bacterial isolate was Escherichia coli (27), and the virus identified most frequently was enterovirus (8). C-reactive protein was increased in 10 out of the 42 cases tested including 8/32 (25%) SIDS. Significant gastric content aspiration was found in 17/57 (29.8%) including 13/40 (32.5%) SIDS. Histological signs of shock were present in 33/55 (60%) cases including 22/39 SIDS (56.4%). The microbiological findings were positive for 27/33 (81.8%). We conclude that post-mortem microbiology is essential in sudden death investigation. The conclusion that a death is unexplained if no microbiology was done is not valid, even if in some cases it may be difficult to know precisely in what way the pathogen contributed to the death.

Autopsy↗
PubMed1999

Molecular and biochemical characterization of VEB-1, a novel class A extended-spectrum beta-lactamase encoded by an Escherichia coli integron gene.

A clinical isolate, Escherichia coli MG-1, isolated from a 4-month-old Vietnamese orphan child, produced a beta-lactamase conferring resistance to extended-spectrum cephalosporins and aztreonam. In a disk diffusion test, a typical synergistic effect between ceftazidime or aztreonam and clavulanic acid was observed along with an unusual synergy between cefoxitin and cefuroxime. The gene for VEB-1 (Vietnamese extended-spectrum beta-lactamase) was cloned and expressed in E. coli JM109. The recombinant plasmid pRLT1 produced a beta-lactamase with a pI of 5.35 and conferred high-level resistance to extended-spectrum (or oxyimino) cephalosporins and to aztreonam. Vmax values for extended-spectrum cephalosporins were uncommonly high, while the affinity of the enzyme for ceftazidime and aztreonam was relatively low. blaVEB-1 showed significant homology at the DNA level with only blaPER-1 and blaPER-2. Analysis of the deduced protein sequence showed that VEB-1 is a class A penicillinase having very low levels of homology with any other known beta-lactamases. The highest percentage of amino acid identity was 38% with PER-1 or PER-2, two uncommon class A extended-spectrum enzymes. Exploration of the genetic environment of blaVEB-1 revealed the presence of gene cassette features, i.e., (i) a 59-base element associated with blaVEB-1; (ii) a second 59-base element just upstream of blaVEB-1, likely belonging to the aacA1-orfG gene cassette; (iii) two core sites (GTTRRRY) on both sides of blaVEB-1; and (iv) a second antibiotic resistance gene 3' of blaVEB-1, aadB. blaVEB-1 may therefore be the first class A extended-spectrum beta-lactamase that is part of a gene cassette, which itself is likely to be located on a class 1 integron, as sulfamide resistance may indicate. Furthermore, blaVEB-1 is encoded on a large (> 100-kb) transferable plasmid found in a Klebsiella pneumoniae MG-2 isolated at the same time from the same patient, indicating a horizontal gene transfer.

Amino Acid Sequence↗
PubMed1999

Cloning, sequence analyses, expression, and distribution of ampC-ampR from Morganella morganii clinical isolates.

Shotgun cloning experiments with restriction enzyme-digested genomic DNA from Morganella morganii 1, which expresses high levels of cephalosporinase, into the pBKCMV cloning vector gave a recombinant plasmid, pPON-1, which encoded four entire genes: ampC, ampR, an hybF family gene, and orf-1 of unknown function. The deduced AmpC beta-lactamase of pI 7.6 shared structural and functional homologies with AmpC from Citrobacter freundii, Escherichia coli, Yersinia enterocolitica, Enterobacter cloacae, and Serratia marcescens. The overlapping promoter organization of ampC and ampR, although much shorter in M. morganii than in the other enterobacterial species, suggested similar AmpR regulatory properties. The MICs of beta-lactams for E. coli MC4100 (ampC mutant) harboring recombinant plasmid pACYC184 containing either ampC and ampR (pAC-1) or ampC (pAC-2) and induction experiments showed that the ampC gene of M. morganii 1 was repressed in the presence of ampR and was activated when a beta-lactam inducer was added. Moreover, transformation of M. morganii 1 or of E. coli JRG582 (delta ampDE) harboring ampC and ampR with a recombinant plasmid containing ampD from E. cloacae resulted in a decrease in the beta-lactam MICs and an inducible phenotype for M. morganii 1, thus underlining the role of an AmpD-like protein in the regulation of the M. morganii cephalosporinase. Fifteen other M. morganii clinical isolates with phenotypes of either low-level inducible cephalosporinase expression or high-level constitutive cephalosporinase expression harbored the same ampC-ampR organization, with the hybF and orf-1 genes surrounding them; the organization of these genes thus differed from those of ampC-ampR genes in C. freundii and E. cloacae, which are located downstream from the fumarate operon. Finally, an identical AmpC beta-lactamase (DHA-1) was recently identified as being plasmid encoded in Salmonella enteritidis, and this is confirmatory evidence of a chromosomal origin of the plasmid-mediated cephalosporinases.

Amino Acid Sequence↗
PubMed1999

Integron- and carbenicillinase-mediated reduced susceptibility to amoxicillin-clavulanic acid in isolates of multidrug-resistant Salmonella enterica serotype typhimurium DT104 from French patients.

Fifty-seven Salmonella enterica serotype Typhimurium (S. typhimurium) isolates were collected from human patients in two French hospitals, Hôpital Antoine Béclère (Clamart, France) and Hôpital Bicêtre (Le Kremlin-Bicêtre, France), between 1996 and 1997. Thirty of them (52 percent) were resistant to amino-, carbeni-, and ureidopenicillins, had reduced susceptibility to amoxicillin-clavulanic acid, were susceptible to cephalothin, and were resistant to sulfonamides, streptomycin, chloramphenicol, and tetracyclines. All these strains possessed a blaPSE-1-like gene and were of phage type DT104. Ten of them were studied in more detail, which revealed that blaPSE-1 is located on the variable region of a class 1 integron. This integron was found to be chromosomally located, as was another class 1 integron containing aadA2, a streptomycin-spectinomycin resistance gene. The reduced susceptibility to amoxicillin-clavulanic acid (and to ticarcillin-clavulanic acid) may result from the high level of hydrolysis of the beta-lactam rather than to the clavulanic acid resistance properties of PSE-1 in these clonally related S. typhimurium isolates.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed1997

[Maternofetal disseminated candidiasis and high-grade prematurity].

BACKGROUND: Despite the frequency of vaginal yeast colonization, serious candidiasis infections in pregnant patients or neonates remain rare. Four cases of disseminated congenital candidiasis in very preterm infants are reported. CASE REPORTS: Congenital Candida albicans infection has been diagnosed in four very preterm infants. In three cases, the mothers had intrauterine devices in place throughout pregnancy. A careful macroscopic examination of the umbilical cord and placenta after birth has allowed an early management strategy in three cases. In all cases, a serious infectious alveolitis occurred. A pronounced increase in white blood cells (> 50,000/mm3) and high levels of both segmented neutrophil and band cells, despite the frequent normality of the CRP, constituted other features. Infection was controlled by parenteral amphotericin B or fluconazole. In one case, serious thrombocytopenia occurred after the first amphotericin B injection requiring substitution for fluconazole. The outcome was unfavourable in two cases with an extensive periventricular leukomalacia. CONCLUSION: Congenital candidiasis in these four very preterm neonates has several features in common: intrauterine contraceptive device during pregnancy, characteristic chorioamnionitis and funisitis, high WBC count, infectious alveolitis. Fluconazole as alternative to amphotericine B therapy is proposed.

Adult↗
PubMed1996

[Does asymptomatic amniotic infection in the second trimester really exist?].

OBJECTIVE: Our purpose was to evaluate the incidence of asymptomatic amniotic fluid infection. STUDY DESIGN: One hundred fifty-four amniotic fluid samples obtained at the second trimester between 14 and 27 weeks gestation were studied by Gram stain with bacteriological cultures and detection of mycoplasm species and Chlamydiae trachomatis. Transabdominal amniocentesis for caryotyping were carried out in 151 health patients with intact membranes and without preterm labor or signs of infectious (3 dizygotic twin pregnancies). RESULTS: One hundred forty-seven complete microbiologic examinations were performed (Gram stain examination white-cell count, quantitative aerobic and anaerobic cultures). Commercial texts for Mycoplasma hominis, Ureaplasma urealyticum and Chlamydiae trachomatis were negative. Three patients had rare microorganisms, coagulase negative staphylococcus (30 and 50 bacteria per ml) and alpha-hemolytic streptococcus (5 x 10(2) bacteria per ml). White cell count on amniotic fluids in 50 cases (32%) was less than 30 per ml. CONCLUSION: These findings appear to be in contradiction with recent data, suggesting the existence of intraamniotic infection in the early phase of the second trimester. Our data confirm the need for a cut-off level for white cell count to improve test sensibility.

Adult↗
PubMed1995

Failure of cefotaxime treatment in two children with meningitis caused by highly penicillin-resistant Streptococcus pneumoniae.

Two infants, aged 8.5 and 11 months, were admitted for meningitis caused by Streptococcus pneumoniae. Failure of cefotaxime led to the identification of highly penicillin-G-resistant strains. Minimum inhibitory concentrations (MICs) for penicillin were > 2 micrograms/ml, and cefotaxime MICs were 2 micrograms/ml. Both patients rapidly responded to a combination of i.v. imipenem and rifampicin. It is now mandatory to test in-vitro susceptibilities of Streptococcus pneumoniae to penicillin G and other beta-lactam agents when meningitis is diagnosed in infants.

Anti-Bacterial Agents↗
PubMed1995

[Prenatal diagnosis of spontaneous thrombosis of the umbilical artery during the third trimester of pregnancy. Two cases with surviving infants].

Thrombosis of the umbilical artery was diagnosed in utero in two cases at the echography examination performed during the third trimester of gestation. The infants were born live and in good health. This is the first report of such antenatal diagnosis. The lack of prospective studies hinder the evaluation of fetal morbidity and mortality. Nevertheless, umbilical artery thrombosis is a high risk obstetrical situation since the potential risk of another thrombus in the second umbilical artery would lead to fetal death in utero. Careful monitoring is required with extraction of the fetus as soon as term allows or whenever the elements compromise fetal development.

Adult↗