Generation of a catR deficient mutant of P. putida KT2440 that produces cis, cis-muconate from benzoate at high rate and yield.

Pseudomonas putida KT2440-JD1 was derived from P. putida KT2440 after N-methyl-N'-nitro-N-nitrosoguanidine (NTG)-mutagenesis and exposure to 3-fluorobenzoate (3-FB). The mutant was no longer able to grow using benzoate as a sole carbon source, but co-metabolized benzoate to cis, cis-muconate during growth on glucose, which accumulated in the growth medium. The specific production rate (q(pm)) was 0.18±0.03 g cis, cis-muconate/(g(DCW) h) in continuous cultures, and increased to 1.4 g cis, cis-muconate/(g(DCW) h) during wash-out cultivation. Transcriptome analysis showed that the cat operon was not induced in P. putida KT2440-JD1 in the presence of 5mM benzoate, due to a point mutation in the highly conserved DNA binding domain of the transcriptional regulator (catR) of the cat operon. The ben operon was highly expressed in the presence of benzoate in the mutant and its parental strain. This operon contains PP_3166 (catA2), which was shown to be a second catechol 1,2-dioxygenase besides catA. P. putida KT2440-JD1 is the first cis, cis-muconate-accumulating mutant that was characterized at the genetic level. The specific production rate achieved is at least eight times higher than those reported for other cis, cis-muconate-producing strains.

Plant MAP kinase kinase kinases structure, classification and evolution.

The increasing number of reports describing plant MAP kinase signalling components reflects the cardinal role that MAP kinase pathways are likely to play during plant growth and development. Relationship and structural analyses of plant MAP kinase kinase kinase related cDNAs and genes established, on one hand, the PMEKKs, which may be distinguished into the alpha, beta, gamma, and zeta groups, and, on the other hand, the PRAFs that consist of the delta, eta and theta groups. Plant MAP3Ks are characterized by different primary structures, but conserved within a single group. A relationship analysis, which included animal, fungal and plant MAP3Ks, revealed a high degree of diversity among this biochemically established set of proteins, thus suggesting a range of biological functions. Four major families emerged, namely the MEKK/STE11, including the PMEKKs, the RAF, including the PRAFs, as well as the MLK and CDC7 families. These four families showed phylum-dependent distributions. Signature sequences characterizing the RAF family and the RAF subfamilies have been evidenced. However, no equivalent sequence motifs were identified for the MEKK/STE11 family, which is highly heterogeneous.

Characterisation of novel plant genes encoding MEKK/STE11 and RAF-related protein kinases.

Various elements of the MAP kinase module have been isolated in plants. We describe here the characterisation of 14 new plant cDNAs and genes encoding putative MAP kinase kinase kinases (MAP3Ks) related to the MEKK/STE11 and RAF protein kinases. Plant MAP3Ks are characterised by a variety of primary structures conserved within closely related proteins. Southern blot analysis suggests that plant MAP3Ks are heterogenous in their genomic structure, existing either as single copy genes or as small gene families. An RT-PCR analysis showed that in Arabidopsis thaliana, all organs studied contain detectable levels of transcripts of each of the MAP3K genes identified; however, signals obtained with mature pollen were weak or non-existent except for AtMAP3Kgamma. None of the reported genes share a cell-cycle or a cold stress regulated expression.

Molecular characterisation of plant cDNAs BnMAP4Kalpha1 and BnMAP4Kalpha2 belonging to the GCK/SPS1 subfamily of MAP kinase kinase kinase kinase.

Several yeast and mammal MAP kinase modules require, upstream of their MAP kinase kinase kinase (MAP3K), a MAP3K kinase (MAP4K). An Arabidopsis thaliana EST clone, sharing identity to MAP4Ks from yeast and mammals, has been used to isolate cDNA clones from a Brassica napus microspore-derived embryo cDNA library. The BnMAP4Kalpha1 and BnMAP4K-alpha2 clones encode putative proteins possessing the 12 subdomains of the serine/threonine protein kinase catalytic domain. A detailed analysis showed that they belong to the GCK/SPS1 subfamily of MAP4K proteins which possess an amino terminal catalytic domain and a long carboxy terminal tail. A Southern blot analysis suggested that the two proteins are encoded by a small multigene family. Expression studies revealed the presence of BnMAP4Kalpha1 and -alpha2 transcripts in all the tissues examined; however, they are most abundant in roots, siliques and flower buds. The expression of BnMAP4Kalpha1 and -alpha2 at the three main developmental stages of microspore-derived embryos (i.e., globular/heart, torpedo and cotyledonary) was confirmed by northern blot and RT-PCR analysis. An expression analysis of the above genes using synchronised Arabidopsis thaliana cell suspensions showed that the homologues genes are cell cycle regulated.

[Focus on the role of ventilation and ultraviolet rays in preventing nosocomial transmission of tuberculosis in health care facilities. Groupe de travail sur la prévention de la transmission nosocomiale de la tuberculose (Direction Générale de la Santé)]. / Le point sur la place de la ventilation et des ultraviolets dans la prévention de la transmission nosocomiale de la tuberculose sur les lieux de soins. Groupe de travail sur la prévention de la transmission nosocomiale de la tuberculose (Direction Générale de la Santé).

Recent episodes of nosocomial tuberculosis, sometimes due to multiresistant strains, in HIV infected patients in the USA has led to the need for new prevention measures against the transmission of Mycobacterium tuberculosis in health care facilities. Tuberculosis is transmitted in Pflügge droplets generated when contagious persons cough. After drying, the droplets become aerosolized solid particles which are rapidly dispersed by air flow within the patient's room. People exposed to the same air are thus at high risk of being contaminated. If the air pressure in the patient's room is higher than the rest of the facility, the air coming form the room may contaminate personnel and other patients elsewhere in the facility. Infecting particles can be eliminated rapidly if the room air is ventilated outdoors. If the ventilation is strong enough so that air constantly circulates from the corridor into the room, infecting particles can no longer diffuse to the rest of the ward. It is also possible to use ultraviolet C light to disinfect the air, either within the room or within the ventilation system. These two basically simple systems are the fundamental environmental and prevention measures needed to limit tuberculosis spread in health care facilities. These methods are however technically complex, costly and require constant evaluation and maintenance by specialized personnel. In addition the potential side effects of ultraviolet waves could considerably reduce their application. These environmental methods, which are complementary methods, only have a meaning if the elementary measures for preventing the transmission of tuberculosis are correctly applied.(ABSTRACT TRUNCATED AT 250 WORDS)

[Occupational risk of exposure to blood in nurses. Results of a one-year monitoring of the risk for nurses in 17 hospitals]. / Exposition accidentelle au sang du personnel soignant. Résultats d'un an de surveillance du risque pour les infirmières dans 17 hôpitaux.

To evaluate the incidence of risk factors for exposure of health care providers to patients' blood, a prospective multicenter study was carried out in 1990 in 17 hospitals in continental France. 521 nurses from 20 departments of medicine and 9 intensive care nurses participated in the study. Trained investigators documented exposures to blood using a standardized questionnaire and carried out monthly 24 hours cross-sectional surveys to determine the number of high risk procedures performed on a given day. One hundred and eighty-three exposures to blood were documented, for an incidence of 0.35/nurse/year. Needle-stick injuries were the most common events (75%). Exposure to blood occurred during a sampling procedure in 48% of cases, an infusion-related procedure in 20% of cases, and an injection in 17% of cases. Comparisons of rates of procedures associated with needle-stick injuries and of procedures performed during a typical day demonstrated differences in the magnitude of the risk associated with each procedure: infusion-related procedures carried the greatest risk, followed by venous blood sampling procedures. Sixty-four percent of exposures to blood occurred after completion of the procedure. Forty-nine percent of documented exposures to blood would probably not have occurred if universal infection control recommendations (CDC, DGS) had been implemented. Twenty-seven percent of exposures to blood involved HIV-positive patients, who accounted for only 7% of patients managed in the participating centers during the study period.(ABSTRACT TRUNCATED AT 250 WORDS)

[Costal stapling in severe thoracic traumas (author's transl)]. / Agrafage costal chez les traumatisés graves du thorax.

Thirty-two of 320 patients with severe thoracic trauma were treated with costal stapling. The technique, described by R. Judet in 1973, is basically simple but sometimes difficult to perform. In the most favourable cases (here 23/32 patients), it avoids tracheostomy and its complications and reduces the restrictive sequelae associated with pleural adhesion or thoracic wall deformities. In addition, active respiratory physiotherapy can be undertaken at an earlier stage. The authors describe the indications and limitations of this treatment on the basis of the results obtained in this series.

[The diagnostic value of quantitative bacteriology in tracheal aspirates compared to lung biopsy (author's transl)]. / Valeur des examens bactériologiques des sécrétions trachéales. Comparaison avec les résultats des biopsies pulmonaires.

An attempt was made to define the value of the bacteriological examination of tracheal aspirations in patients on artificial ventilation. Quantitative cultures of lung biopsies, taken immediately after death, were made on 21 patients in an intensive care unit. The results were compared with the clinical signs, antibiotic therapy and quantitative cultures of tracheal secretions taken before and very soon after death. A comparison of the results shows that microbial species present in tracheal secretions at a level equal to or greater than 10(7)/ml were found in 53 percent of lung biopsies. However, the predominant bacteria found in the lung biopsies were not necessarily similar to those in the tracheal secretions. Also, bacteria minimally present or completely absent in tracheal secretions could be found in lung biopsies. Therapeutic decisions can only be made on clinical and radiological signs; bacteriological examination may be a help in the choice of drugs once such treatment has been decided upon.