[Surgical wound infections due to Pseudomonas aeruginosa in orthopedic surgery]. / Cas groupes d'infections du site opératoire a Pseudomonas aeruginosa en orthopédie/traumatologie.

OBJECTIVE: The department of infection control carried out an investigation to search for the origin of 4 surgical site infections and 1 wound colonization by Pseudomonas aeruginosa in patients having undergone orthopedic surgery. PATIENTS AND METHODS: The authors retrospectively reviewed the medical records, the clinical data of the operating units, as well as the bacteriological assessments of the infected patients. Multiple environmental samples were made to screen for P. aeruginosa and care giving was evaluated. RESULTS: The 5 patients underwent surgery between August and September 2001 with various surgeons and were followed-up by various paramedics. The surgical procedures were varied and performed in different operating rooms. Various P. aeruginosa serotypes were isolated. No specific event could be related to the infections concerning the surgical procedures. In 3 of the 5 patients, non-sterile cotton jersey had been used, either normally (plaster or plaster splint) or after sterilization (wrapping of wounded limbs before surgical procedure). The culture samplings of non-sterile jersey were always contaminated by Enterobacteriaceae or Pseudomonas sp., with 2 positives cultures of P. aeruginosa. Only one water sample was positive, whereas other environmental samples remained negative. The reorganization of jersey supply put an end to this epidemic phenomenon. CONCLUSION: The most probable hypothesis for surgical wound infection was the cotton jersey in 3 of the 5 cases.

Generation of a large complex antibody library from multiple donors.

We have generated a large complex library of single chain antibodies based on four individual libraries from each of 50 donors. DNA coding for the heavy and light chain variable domains of the IgM and IgG repertoires was amplified by PCR using two different sets of primers. Each individual library was composed of approximately 1-5x10(7) independent clones giving a final combined library of 4x10(9) members. Screening this library by phage display of single chain antibodies with small haptens, peptides and proteins yielded specific antibodies for each class of antigen.

Golgi-mediated post-translational processing of secretory acid phosphatase by Leishmania donovani promastigotes.

Monensin, an inhibitor of Golgi function, was used to investigate the role of this cell compartment in the glycosylation of Leishmania donovani promastigote secretory acid phosphatase (EC 3.1.3.2). Monensin-treated cells demonstrated morphological changes in the Golgi complex and secreted enzyme with an altered electrophoretic mobility: two discrete bands of approximately 95 and 110 kDa were found, as compared to the heterodisperse nature of the enzyme from untreated controls. Chemical deglycosylation by mild acid hydrolysis resulted in a similar effect on the electrophoretic mobility of purified extracellular enzyme. Acid phosphatase was also treated with N-glycosidase F (EC 3.5.1.52) to remove N-linked oligosaccharides. The altered lectin-binding properties of the enzyme after these two treatments demonstrated that an unusual type of galactose-containing acid-labile carbohydrate was present in secretory acid phosphatase in addition to the N-linked oligosaccharides. Further, experiments with 32P-labelled enzyme indicated that phosphodiester bonds were the structural component responsible for the sensitivity of this carbohydrate to mild acid hydrolysis. Cumulatively, these results demonstrated that a novel form of Golgi-mediated posttranslational modification had occurred to the secretory acid phosphatase presumably by the addition of an acid-labile phosphoglycan.

Effect of dietary phosphorus, calcium, and phytase on performance of growing turkeys.

Female and male turkeys were fed 110, 73, 52, and 30% of the NRC (1994) nonphytate P (NPP) requirement without and with 500 phytase units (FTU)/kg during 4 to 14 or 16 wk of age, respectively. At 110% P (control; also 110% of NRC Ca), phytase was without effect. At 73% of NPP (100% Ca), without phytase, performance was similar to the control; with phytase, performance was equivalent, and in some stages, superior to the control. At 52% of NPP (90% Ca), performance was inferior without phytase and was variably similar or poorer than the control with phytase. At 30% NPP without phytase, poults gained poorly and showed a high incidence of leg disorder at 8 wk when they were removed from experiment; poults gained better with 80% NRC Ca compared with 110%. At 30% NPP with phytase, turkeys performed remarkably well, although suboptimally, at 80 or 110% NRC Ca. Phytase at 400, 300, and 200 FTU/kg with increasing age periods performed as well as 500 FTU/kg with 73% of NRC NPP (100% Ca) and 52% NRC NPP (90% Ca). These lower phytase levels were not as sufficient as 500 FTU/kg with 30% of NRC NPP; this inadequacy was more severe with higher dietary calcium. Phytase was effective in reducing dietary P requirements of growing turkeys when the NPP levels were below NRC (1994) requirements.

Leishmania donovani: immunochemical localization and secretory mechanism of soluble acid phosphatase.

Monoclonal antibodies specific for the soluble, secreted acid phosphatase (EC 3.1.3.2) of Leishmania donovani were used to investigate the localization of this enzyme in extracellular promastigotes and intracellular amastigotes. Indirect immunofluorescence showed a weak general staining in the promastigote cytoplasm, together with strong fluorescence in the flagellar reservoir. Immunofluorescence studies on U937 cells infected in vitro with L. donovani showed that the pathogenic amastigote stage also produced soluble acid phosphatase. Metabolic labeling experiments using promastigotes indicated that the intracellular enzyme was soluble prior to secretion and no evidence was found for the association of secretory acid phosphatase with cell membranes after protein synthesis. The rapid release of acid phosphatase from the flagellar reservoir was energy dependent and may be coupled to beating of the flagellum. The results demonstrated that acid phosphatase was secreted into the flagellar reservoir by Leishmania promastigotes using a conventional constitutive secretory mechanism, and subsequently released from the reservoir into the extracellular medium.

Human RanGTPase-activating protein RanGAP1 is a homologue of yeast Rna1p involved in mRNA processing and transport.

RanGAP1 is the GTPase activator for the nuclear Ras-related regulatory protein Ran, converting it to the putatively inactive GDP-bound state. Here, we report the amino acid sequence of RanGAP1, derived from cDNA and peptide sequences. We found it to be homologous to murine Fug1, implicated in early embryonic development, and to Rna1p from Saccharomyces cerevisiae and Schizosaccharomyces pombe. Mutations of budding yeast RNA1 are known to result in defects in RNA processing and nucleocytoplasmic mRNA transport. Concurrently, we have isolated Rna1p as the major RanGAP activity from Sc. pombe. Both this protein and recombinant Rna1p were found to stimulate RanGTPase activity to an extent almost identical to that of human RanGAP1, indicating the functional significance of the sequence homology. The Ran-specific guanine nucleotide exchange factor RCC1 and its yeast homologues are restricted to the nucleus, while Rna1p is reported to be localized to the cytoplasm. We suggest a model in which both activities, nuclear GDP-to-GTP exchange on Ran and cytoplasmic hydrolysis of Ran-bound GTP, are essential for shuttling of Ran between the two cellular compartments. Thus, a defect in either of the two antagonistic regulators of Ran would result in a shutdown of Ran-dependent transport processes, in agreement with the almost identical phenotypes described for such defects in budding yeast.