Search PubMed⌕ Search

Biomedical subjects

N Lambert-Zechovsky

Publications and source records attributed to N Lambert-Zechovsky.

At least 19 recordsLinked to original sources
PubMed1999

[Current microbiological problems. Antibiotic resistance and therapeutic problems raised by Pseudomonas aeruginosa].

RESISTANCE: Pseudomonas aeruginosa is characterized by its low intrinsic susceptibility to many antibiotics and its capacity to acquire additional resistance mechanisms to usually active drugs. Some beta-lactam resistance mechanisms are well known (penicillinase production, cephalosporinase overproduction) and others have been recently identified, such as active efflux systems, which confer coresistance to quinolones, and new beta-lactamases which are limited to a few countries (extended-spectrum beta-lactamases, imipenemase). Ceftazidime remains the most active beta-lactam agent. ACTIVE DRUGS: Among aminoglycosides, amikacin and isepamicin are the most frequently active drugs. The use of fluoroquinolones is limited by a high incidence of acquired resistance. The percentage of resistant strains is highly variable according to countries, hospitals and wards. CLINICAL PRACTICE: Therapy, usually based on a beta-lactam-aminoglycoside combination, will be empirical at first, according to local epidemiological factors, site of infection and previously administered antibiotics, then re-evaluated according to susceptibility results.

Cross Infection↗
PubMed1998

Purulent pleurisy caused by Campylobacter lari.

An 80-year-old debilitated patient developed purulent pleurisy caused by a Campylobacter lari isolate. The patient underwent surgical drainage and received antibiotic therapy with amoxicillin/clavulanic acid and ofloxacin. Antibiotic susceptibility data showed that the isolate was fully sensitive to clarithromycin, tetracycline, aminoglycosides. and ciprofloxacin. Imipenem and amoxicillin plus clavulanic acid were the most active beta-lactam agents.

Aged↗
PubMed1998

Multi-resistant Pseudomonas aeruginosa outbreak associated with contaminated tap water in a neurosurgery intensive care unit.

From July 1995 to November 1996, multi-resistant Pseudomonas aeruginosa O11 was isolated from 36 patients admitted to a neurosurgery intensive care unit. The strain was resistant to ticarcillin, ceftazidime, imipenem, gentamicin and ciprofloxacin, and susceptible to amikacin. Nine patients were colonized only; the remaining 27 patients had at least one infected site (17 urinary infections, 10 pneumonias and four with sinusitis). P. aeruginosa O11 with the same resistance pattern was isolated from tap water. The strain was also cultured from enteral nutrition solutions given to two infected patients. DNA macrorestriction analysis with XbaI established the similarity of the isolates from patients, tap water and solutions. The outbreak was controlled after reinforcement of isolation procedures for infected patients, changing the mode of enteral nutrition and replacement of all sinks in the unit. The sinks were presumably the main source of P. aeruginosa during this outbreak, via the hands of the nursing staff or nutrition solutions contaminated with tap water.

Adolescent↗
PubMed1998

Clinical significance of bacteremia involving the "Streptococcus milleri" group: 51 cases and review.

Fifty-one cases of bacteremia due to the "Streptococcus milleri" group were analyzed. Among these were 40 patients with underlying diseases, and associated local infections were present in 27 patients. The most frequent sites of infection were the thoracic cavity and the digestive and hepatobiliary tracts. A probable portal of entry related to mucosal-barrier trauma was identified for an additional 16 patients. The origin of bacteremia was unknown for the remaining eight patients. Abscess formation was evident for only six patients, and there were no cases of endocarditis. Multiple positive blood cultures and polymicrobial bacteremia were associated significantly with the presence of local sites of infection. The most common causative species were Streptococcus anginosus and Streptococcus constellatus. Two patients died of bacteremia.

Abscess↗
PubMed1998

Long-term investigation of the clonal dissemination of Klebsiella pneumoniae isolates producing extended-spectrum beta-lactamases in a university hospital.

Seventy isolates of Klebsiella pneumoniae with extended-spectrum beta-lactamases (ESBLs) were compared. These were isolated from 51 patients on 10 separate wards in one hospital over an 18-month period between 1992 and 1994. Antibiograms were determined and the isolates were typed by pulsed-field gel electrophoresis of their DNA digestion with XbaI. The isolates were compared to three genotypically different epidemic strains responsible for previous outbreaks at the hospital between 1988 and 1991. Isolates from 84% of the present patients had closely related XbaI patterns, and most (74%) produced an ESBL with an iso-electric point (pI) of 7.0. A similar pattern was found for one of the previous epidemic strains, but it produced an ESBL with a pI of 7.8; isolates with this latter enzyme variant were found only in six of the present patients. The two other previous epidemic strains had ESBLs with a pI of 6.3 and organisms related to them were found in one and two of the present patients, respectively.

Cephalosporins↗
PubMed1998

[Bacteria isolated from protected bronchopulmonary samples: variation as a function of the previous length of stay in the recovery room].

We retrospectively reviewed the variation of the organisms recovered from 403 protected bronchopulmonary specimens in three surgical intensive care units according to the time elapsed from admission. The predominant pathogens during the four first days were Haemophilus influenzae (33.3%), Staphylococcus aureus (18.2%), mostly methicillin susceptible strains, and Streptococcus pneumoniae (14.3%). After the fourth day, they were progressively replaced by typical nosocomial bacteria such as methicillin resistant Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. For Pseudomonas aeruginosa and cephalosporinase-producing Enterobacteriaceae, strains resistant to third generation cephalosporins occurred significantly later than the susceptible strains. These results indicate that the time elapsed from intensive care unit admission has a major influence on the bacteriology of respiratory tract infections, but no clear cut-off point between early-onset and late onset pneumonia is evident.

Bacteria↗
PubMed1997

Differentiation of human and animal strains of Streptococcus dysgalactiae by pulsed-field gel electrophoresis.

The genetic diversity among 54 human isolates and 33 animal isolates belonging to the species Streptococcus dysgalactiae (20 alpha-haemolytic Streptococcus dysgalactiae, 23 Streptococcus equisimilis, 43 group G streptococci and one group L streptococcus) was evaluated by macrorestriction analysis of chromosomal DNA with SmaI and resolution by pulsed-field gel electrophoresis. This technique revealed a high degree of intraspecies polymorphism, leading to the differentiation of 80 distinct banding patterns, and identified the presence of two major clusters, one containing isolates of human origin and the other isolates of animal origin. These results suggest than human and animal isolates of S.dysgalactiae are genetically distinct, and support the recent proposal of the subspecies S. dysgalactiae subsp. equisimilis for human isolates. The heterogeneity revealed within isolates from the same host type indicates that pulsed-field gel electrophoresis is a powerful epidemiological tool for studying S. dysgalactiae infections.

Animals↗
PubMed1997

Pulsed-field gel electrophoresis is more discriminating than multilocus enzyme electrophoresis and random amplified polymorphic DNA analysis for typing pyogenic streptococci.

The SmaI restriction endonuclease digestion patterns of chromosomal DNAs from 99 pyogenic streptococci belonging to Lancefield group A (41 Streptococcus pyogenes), group C (seven S.dysgalactiae, 11 "S. equisimilis", three S. equi, eight S. zooepidemicus) and group G (25 human group G Streptococcus, four S. canis) were analyzed by pulsed-field gel electrophoresis (PFGE), and the results were compared with those previously obtained by multilocus enzyme electrophoresis (MLEE) and random amplified polymorphic DNA analysis (RAPD). PFGE revealed 93 distinct types among the 99 strains, and no patterns were common to strains of different species. The discriminatory power of PFGE was greater than that of MLEE and RAPD for groups A and G streptococci. The polymorphism among group C streptococci was similar with the three techniques. PFGE is, therefore, the most efficacious method for epidemiological typing of pyogenic streptococci.

DNA, Bacterial↗
PubMed1997

Epidemiological typing of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolates responsible for five outbreaks in a university hospital.

Thirty-seven isolates of extended-spectrum beta-lactamase-producing (ESBL) Klebsiella pneumoniae implicated in five nosocomial outbreaks (I-V) on three distinct wards of our hospital were compared using capsular typing, biotyping, antibiotyping, enzyme electrophoresis typing and DNA macrorestriction analysis with Xba I resolved by pulsed-field gel electrophoresis. The isolates from each outbreak had common phenotypic and genotypic characteristics indicating that they were related epidemiologically. Isolates from outbreaks I (four patients) and V (13 patients), although they occurred in two different wards (neurology and surgery) and three years apart, produced the same ESBL with a pI of 7.8 (SHV-4) and were of serotype K25. The Xba I patterns were closely related. The isolates of outbreaks II (seven patients), III (four patients) and IV (seven patients), which occurred in a single surgical intensive care unit, produced an ESBL with a pI of 6.3 (TEM-3). Isolates from outbreaks III and IV, which occurred six months apart, were of serotype K68 and had similar Xba I patterns suggesting that the two outbreaks were due to a single strain which persisted endemically in the ward. The isolates from outbreak II were of serotype K62, and had distinct characteristics from the two later outbreaks. The Xba I patterns of the isolates from outbreaks "I and V', II and "III and IV' had Dice similarity coefficients under 40% showing that the three groups were genetically distant. DNA macrorestriction analysis was a useful complement to phenotypic methods for identifying K. pneumoniae strains responsible for outbreaks harbouring a common ESBL.

Cross Infection↗
PubMed1997

Arbitrary primed PCR rules out Clostridium difficile cross-infection among patients in a haematology unit.

Eight out of 20 (40%) patients with haematological malignancies hospitalized in the same unit of our hospital from 24 January to 24 April 1995, suffered from diarrhoea due to Clostridium difficile. The C. difficile isolates were characterized by serotyping and by arbitrary primed polymerase chain reaction (AP-PCR) using three different 10-mer oligonucleotides. It was found by serotyping that five patients had non-typeable isolates and three had serogroup H isolates. The AP-PCR typed all the isolates and yielded various patterns suggesting that there had been no cross-transmission between the patients. Control faecal sample cultures showed that two patients were still carrying the same isolates after specific treatment with vancomycin or metronidazole, and that one patient had acquired an isolate with a new AP-PCR type. AP-PCR was found to be a rapid, effective discriminative method for the immediate epidemiological tracking of hospital-acquired infections due to C difficile.

Adult↗
PubMed1997

Septicemia caused by Streptococcus canis in a human.

We describe a case of septicemia due to Streptococcus canis in a 77-year-old man. The organism was presumably transmitted from a domestic animal. Ulcers of the lower limbs were the likely portals of entry. The differentiation between Streptococcus canis and Streptococcus dysgalactiae was based on biochemical properties and DNA macrorestriction analysis by pulsed-field gel electrophoresis.

Aged↗
PubMed1996

Elution of six antibiotics bonded to polyethylene vascular grafts sealed with three proteins.

The elution of six antistaphylococcal antibiotics from vascular polyethylene grafts sealed with albumin, gelatin, or collagen were studied in an in vitro system. The antibiotics tested were pefloxacin, vancomycin, teicoplanin, fusidic acid, pristinamycin, and rifampicin. The grafts were impregnated by simple soaking in antibiotic (1 mg/ml). The data were fitted to an exponential model and antibiotic half-lives (t1/2) were calculated from the regression lines. All the antibiotics tested were bound to the protein sealants. Antibiotic release varied with the type of antibiotic and the sealant. Rifampicin was eluted most slowly, particularly with albumin- and gelatin-sealed grafts, with t1/2 at 4-5.5 hr and antibiotic activity was still found at 48 hr. The glycopeptides were also eluted more slowly from albumin or gelatin sealant than from collagen. Although large quantities of glycopeptides were initially bound, they were quickly eluted (t1/2 = 30-44 min) and there was no residual antibiotic activity at 24 hr. Pefloxacin, pristinamycin, and fusidic acid bound to collagen or gelatin sealants were the most rapidly eluted, with t1/2 of 3-14 min, but they were eluted more slowly from albumin-sealed grafts, with t1/2 of 22-90 min. In vitro studies can be useful for evaluating the binding of antibiotics to protein-sealed grafts before animal experiments or human testing.

Albumins↗
PubMed1996

Sinusitis in mechanically ventilated patients and its role in the pathogenesis of nosocomial pneumonia.

Nosocomial sinusitis is a complication of endotracheal intubation and mechanical ventilation in critically ill patients. Its incidence is often underestimated because of a lack of clinical signs. It is suspected in patients with nasal discharge or unexplained fever. Its diagnosis is based on radiological examination, by radiograph or computed tomography scan, and microbiological cultures of maxillary sinus aspirate. Maxillary sinusitis is often associated with involvement of the sphenoid, ethmoid, and/or frontal sinuses. Its incidence varies greatly according to diagnostic criteria and the population studied. Infectious sinusitis is less frequent than noninfectious sinusitis, occurring in 20 to 30% of patients intubated for at least seven days. Its incidence is higher in nasotracheally than in orotracheally intubated patients. Other risk factors include nasogastric tubes and head trauma. The main causative agents are gram-negative bacilli, primarily Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacteriaceae, but Staphylococcus aureus and yeasts are also common. Patients with nosocomial sinusitis are more likely to develop pneumonia than those without sinusitis. The sinus provides a bacterial reservoir from which organisms may seed the tracheobronchial tree. The association of sinusitis and pneumonia is mainly due to Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii. The treatment of sinusitis is based on the removal of all nasal tubes, topical decongestants, and maxillary sinus drainage and lavage. The role of intravenous antibiotics is controversial.

Anti-Bacterial Agents↗
PubMed1996

Comparative distribution of resistance patterns and serotypes in Pseudomonas aeruginosa isolates from intensive care units and other wards.

The resistance patterns and O-serotypes of 2952 Pseudomonas aeruginosa isolates were studied and the relationship between patterns and serotypes was investigated. The penicillinase-producing and cephalosporinase-overproducing phenotypes were significantly more frequent in intensive care units than other wards, but there was no difference for the intrinsic resistance phenotype. The predominant serotypes were O6, O11 and O1. The incidence of serotype O12 was low. O11 isolates were more common in intensive care units and more resistant to all antibiotics than other isolates. Most O12 isolates had a penicillinase-producing phenotype and were resistant to aminoglycosides and ciprofloxacin, but susceptible to fosfomycin.

Aminoglycosides↗
PubMed1996

Analysis of genetic relationships among strains of groups A, C and G streptococci by random amplified polymorphic DNA analysis.

Random amplified polymorphic DNA (RAPD) analysis was evaluated for its capacity to distinguish species and strains within species of groups A, C and G streptococci. The 99 strains tested, previously typed by multilocus enzyme electrophoresis (MLEE), included 41 group A streptococci (Streptococcus pyogenes), 25 group G Streptococcus spp. (GGS), seven S. dysgalactiae, 11 S. equisimilis, four S. canis, three S. equi and eight S. zooepidemicus. The combined data obtained with three single primers distinguished 82 types. RAPD analysis provided taxonomic results that were in general agreement with previous species classification based on DNA-DNA homology and MLEE. The intraspecies typing efficiency of the technique was significantly improved by the parallel use of several primers. RAPD analysis had greater discriminatory power than MLEE for GAS and GGS. There was not total agreement between the two techniques as RAPD distinguished strains with identical electrophoretic types, whereas MLEE differentiated strains with identical PCR types. RAPD analysis did not distinguish all GAS strains with different biotypes and its already high discriminatory power was further enhanced by concomitant biotyping.

Animals↗
PubMed1996

Persistence of Staphylococcus aureus strains among cystic fibrosis patients over extended periods of time.

Pulsed-field gel electrophoresis (PFGE) of SmaI macrorestriction fragments of chromosomal DNA was used to confirm the persistence of methicillin-sensitive Staphylococcus aureus isolates in the sputum of 25 cystic fibrosis patients in five French hospitals. Three-to-eight consecutive isolates, with the same esterase electrophoretic type isolated from each patient over a period of 12-28 months, were analysed. Consecutive isolates with indistinguishable PFGE profiles were found in 12 patients (48%) and consecutive isolates with similar PFGE profiles showing minor differences of one-to-four fragments (similarity coefficient >/=84%) were found in 11 patients. Consecutive isolates with different PFGE profiles were obtained from only two patients, but the profiles found in each patient were more closely related to each other than to other profiles. The results were in agreement with esterase electrophoretic typing for 23 patients, and we considered that those patients were infected with a single persistent strain. For any given patient, variations in antibiotypes and phage types of consecutive isolates were not associated with major genotypic variations. PFGE is useful in confirming the persistence of S. aureus strains in cystic fibrosis patients over long periods.

Anti-Bacterial Agents↗