Jpn J Antibiot, 2002 Feb, 55(1), 61 - 6 {In vitro interaction of tazobactam/piperacillin combined with aminoglycosides against Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli AND Staphylococcus aureus}; Yamada H et al.; The in vitro combination effect of tazobactam/piperacillin (TAZ/PIPC) with aminoglycosides (amikacin (AMK) and isepamicin (ISP)) were investigated by the checkerboard dilution method against PIPC-resistant and TAZ/PIPC-susceptible Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli and Methicillin-sensitive Staphylococcus aureus (MSSA) . The following results were obtained . 1 . The combination of TAZ/PIPC with AMK showed synergistic effect for 66.7% of P . aeruginosa and 9.1% of K . pneumoniae and additive effect for 76.9% of E . coli and 74.1% of MSSA . The antagonistic effect of TAZ/PIPC with AMK was not demonstrated for all tested strains . 2 . The combination of TAZ/PIPC with ISP showed synergistic effect for 61.9% of P . aeruginosa and 22.7% of K . pneumoniae and additive effect for 84.6% of E . coli and 66.7% of MSSA . The antagonistic effect of TAZ/PIPC with ISP was not demonstrated for all tested strains . In conclusion, these results suggest that the combination therapies of TAZ/PIPC with aminoglycosides are useful for the clinical treatment of sepsis caused by above four species. Am J Health Syst Pharm, 2002 Apr 15, 59(8 Suppl 3), S4 - 6 Assessing the impact of antimicrobial resistance; Gums JG; Trends in infectious disease mortality, contributing factors, and resistance patterns of commonly isolated microorganisms are described . Antimicrobial resistance was first reported in 1941 with sulfonamides . The frequency of antimicrobial resistance has increased in hospital and community settings, resulting in therapeutic failures, the use of increasingly costly and toxic antimicrobials, extended hospital stays, and increased morbidity, mortality, and health care costs . Retrospective analysis of infectious disease mortality in the United States reveals that resistance has increased despite the development of new antimicrobials . Factors contributing to antimicrobial resistance include patients' expectations of receiving an antimicrobial prescription after an office visit (even when one is not warranted), low vaccination rates among the elderly, international travel, and continuous exposure to small amounts of antimicrobials in the food supply . Analysis of susceptibility and resistance patterns of more than 10.3 million isolates found that 36%, 30%, and 31% of Escherichia coli isolates were resistant to ampicillin, ampicillin-sulbactam, and piperacillin, respectively . E . coli and Klebsiella pneumoniae exhibited reduced susceptibility to ceftazidime in certain regions of the country . Pseudomonas aeruginosa exhibited resistance to ciprofloxacin, imipenem, gentamicin, and ceftazidime . The occurrence of ciprofloxacin- and levofloxacin-resistant Staphylococcus aureus was similar, while the frequency of erythromycin-resistant S . aureus varied widely nationwide . Nationwide susceptibility to cefotaxime was significantly lower than that to ceftriaxone . Antimicrobial resistance is an increasing problem that contributes to morbidity, mortality, and increased health care costs . Analysis of susceptibility and resistance patterns of specific microorganisms is necessary to gain further insight into the causes of antimicrobial resistance and ways to reduce it. J Bacteriol, 2002 May, 184(10), 2709 - 18 Caulobacter crescentus synthesizes an S-layer-editing metalloprotease possessing a domain sharing sequence similarity with its paracrystalline S-layer protein; Umelo-Njaka E et al.; Strains of Caulobacter crescentus elaborate an S-layer, a two-dimensional protein latticework which covers the cell surface . The S-layer protein (RsaA) is secreted by a type I mechanism (relying on a C-terminal signal) and is unusual among type I secreted proteins because high levels of protein are produced continuously . In efforts to adapt the S-layer for display of foreign peptides and proteins, we noted a proteolytic activity that affected S-layer monomers with foreign inserts . The cleavage was precise, resulting in fragments with an unambiguous N-terminal sequence . We developed an assay to screen for loss of this activity (i.e., presentation of foreign peptides without degradation), using transposon and traditional mutagenesis . A metalloprotease gene designated sap (S-layer-associated protease) was identified which could complement the protease-negative mutants . The N-terminal half of Sap possessed significant similarity to other type I secreted proteases (e.g., alkaline protease of Pseudomonas aeruginosa), including the characteristic RTX repeat sequences, but the C-terminal half which normally includes the type I secretion signal exhibited no such similarity . Instead, there was a region of significant similarity to the N-terminal region of RsaA . We hypothesize that Sap evolved by combining the catalytic portion of a type I secreted protease with an S-layer-like protein, perhaps to associate with nascent S-layer monomers to "scan" for modifications. J Bacteriol, 2002 May, 184(10), 2620 - 5 The O-antigen gene cluster of Escherichia coli O55:H7 and identification of a new UDP-GlcNAc C4 epimerase gene; Wang L et al.; Escherichia coli O55 is an important antigen which is often associated with enteropathogenic E . coli clones . We sequenced the genes responsible for its synthesis and identified genes for O-antigen polymerase, O-antigen flippase, four enzymes involved in GDP-colitose synthesis, and three glycosyltransferases, all by comparison with known genes . Upstream of the normal O-antigen region there is a gne gene, which encodes a UDP-GlcNAc epimerase for converting UDP-GlcNAc to UDP-GalNAc and is essential for O55 antigen synthesis . The O55 gne product has only 20 and 26% identity to the gne genes of Pseudomonas aeruginosa and E . coli O113, respectively . We also found evidence for the O55 gene cluster's having evolved from another gene cluster by gain and loss of genes . Only three of the GDP-colitose pathway genes are in the usual location, the other two being separated, although nearby . It is thought that the E . coli O157:H7 clone evolved from the O55:H7 clone in part by transfer of the O157 gene cluster into an O55 lineage . Comparison of genes flanking the O-antigen gene clusters of the O55:H7 and O157:H7 clones revealed one recombination site within the galF gene and located the other between the hisG and amn genes . Genes outside the recombination sites are 99.6 to 100% identical in the two clones, while most genes thought to have transferred with the O157 gene cluster are 95 to 98% identical. J Bacteriol, 2002 May, 184(10), 2576 - 86 Advancing the quorum in Pseudomonas aeruginosa: MvaT and the regulation of N-acylhomoserine lactone production and virulence gene expression; Diggle SP et al.; Pseudomonas aeruginosa regulates the production of many exoproteins and secondary metabolites via a hierarchical quorum-sensing cascade through LasR and RhlR and their cognate signal molecules N-(3-oxododecanoyl)-L-homoserine lactone (3O-C12-HSL) and N-(butanoyl)-L-homoserine lactone (C4-HSL) . In this study, we found that transcription of the quorum sensing-regulated genes lecA (coding for PA-IL lectin), lasB (coding for elastase), and rpoS appeared to be growth phase dependent and their expression could not be advanced to the logarithmic phase in cells growing in batch culture by the addition of exogenous C4-HSL and 3O-C12-HSL . To identify novel regulators responsible for this growth phase dependency, a P . aeruginosa lecA::lux reporter strain was subjected to random transposon mutagenesis . A number of mutants affected in lecA expression were found that exhibited altered production of multiple quorum sensing-dependent phenotypes . While some mutations were mapped to new loci such as clpA and mvaT and a putative efflux system, a number of mutations were also mapped to known regulators such as lasR, rhlR, and rpoS . MvaT was identified as a novel global regulator of virulence gene expression, as a mutation in mvaT resulted in enhanced lecA expression and pyocyanin production . This mutant also showed altered swarming ability and production of the LasB and LasA proteases, 3O-C12-HSL, and C4-HSL . Furthermore, addition of exogenous 3O-C12-HSL and C4-HSL to the mvaT mutant significantly advanced lecA expression, suggesting that MvaT is involved in the growth phase-dependent regulation of the lecA gene. Kansenshogaku Zasshi, 2002 Mar, 76(3), 188 - 94 {Pneumonia associated with lung cancer in the elderly}; Kobashi Y et al.; We investigated the clinical characteristics separating pneumonia as a complication in elderly lung cancer patients into obstructive and non-obstructive pneumonia . Two hundred and five patients with pneumonia as a complication in elderly lung cancer patients were classified into two groups; 64 patients with obstructive pneumonia and 141 patients with non-obstructive pneumonia . Most of the patients in both groups were male . Concerning histological findings, while most of the patients with obstructive pneumonia had squamous cell carcinoma, those with non-obstructive pneumonia had the same proportion of squamous cell carcinoma as all elderly patients with lung cancer . Most of the patients with obstructive pneumonia were in good general condition including their nutritional condition, but the patients with non-obstructive pneumonia were in significantly poor condition . A low percent of microorganisms were isolated from the sputum obtained from the patients with non-obstructive pneumonia, but a high percentage were obtained from those with non-obstructive pneumonia . Frequent involvement of gram-negative bacilli such as Pseudomonas aeruginosa and Klebsiella pneumoniae or Staphylococcus aureus containing MRSA was also found in these patients . Regarding treatment, although carbapenem was used either alone or in combination therapy as the regimen of treatment for pneumonia as a complication in elderly lung cancer patients with both the obstructive and non-obstructive pneumonia patients, the efficacy rate was poor in 50% with obstructive pneumonia and in 26% with non-obstructive pneumonia . The mortality rate was 11% in the patients with obstructive pneumonia, while it was 61% in the patients with non-obstructive pneumonia . The prognosis was significantly poorer in the patients with non-obstructive pneumonia . We concluded that although the prognosis was not so poor for patients with obstructive pneumonia if the appropriate treatment was given, in the patients with non-obstructive pneumonia, the treatment for underlying diseases and the improvement of their general condition, including the determination of causative microorganisms, was important. Am J Respir Cell Mol Biol, 2002 May, 26(5), 617 - 26 Early mitochondrial dysfunction, superoxide anion production, and DNA degradation are associated with non-apoptotic death of human airway epithelial cells induced by Pseudomonas aeruginosa exotoxin A; Plotkowski MC et al.; It has been shown that bacterial exoproducts may induce airway epithelium injury . During the epithelial repair process, the respiratory epithelial cells no more establish tight junctional intercellular complexes and may be particularly susceptible to bacterial virulence factors . In this study, we analyzed the effect of Pseudomonas aeruginosa exotoxin A (ETA) at different periods of time and concentrations on 16 HBE 14o(-) human bronchial epithelial cells in culture conditions inducing a phenotype of repairing cells . ETA treatment for 24 and 48 h led to the killing of 40.0 +/- 5.7% and 79.0 +/- 1.4% of the cells, respectively, as determined by the dimethylthiazole 2,5 diphenyl tetrazolium bromide assay . At 1,000 ng/ml, ETA led to the killing of 25.2 +/- 6.6, 59.4 +/- 5.9, and 82.3 +/- 3.7% of the cells, after treatment periods of 7, 24, and 48 h, respectively . Cell death could not be inhibited by z-VAD-fmk, a broad spectrum caspase inhibitor . By transmission electron microscopy, ultrastructural characteristics described in apoptosis were not detected in ETA-treated cells . Instead, the mitochondria of cells treated for 24 and 48 h with ETA at 100 and 1,000 ng/ml were highly condensed . Human nasal polyp epithelial cells in primary culture exposed to ETA at 1,000 ng/ml did not exhibit characteristic features of apoptotic cells either . Cytofluorometric analysis of ETA-treated 16 HBE 14o(-) cells labeled with DiOC(6)(3) and hydroethidine showed a time- and dose-dependent reduction of the mitochondrial transmembrane potential, detected 7 h after ETA treatment, and an increase in superoxide production, detected at 24 h, respectively . By a photometric assay, DNA degradation was also detected 7 h after cell treatment with ETA at 100 and 1,000 ng/ml . Taken together, our results show that ETA-induced death of epithelial respiratory cells was preceded by early mitochondrial dysfunction and superoxide anion production, but was not followed by the classically described apoptotic pathways. J Appl Microbiol, 2002, 92(4), 729 - 36 Antimicrobial susceptibility changes and T-OMP shifts in pyrithione-passaged planktonic cultures of Pseudomonas aeruginosa PAO1; Abdel-Malek SM et al.; AIMS: The aim of this study was to determine whether passaging Pseudomonas aeruginosa PAO1 with sub-MICs of the pyrithione biocides results in both the induction of decreased susceptibility towards these antimicrobials and associated outer membrane profile changes . METHODS AND RESULTS: Previous work by this group has shown that it is possible to induce susceptibility changes towards the isothiazolone biocides in Ps . aeruginosa PAO1 by successive passages in the presence of increasing sub-MICs of biocide . This procedure was accompanied by the loss of a 35 kDa outer membrane protein, T-OMP . In this experiment, this process was repeated with the biocides sodium pyrithione (NaPT), zinc pyrithione (ZnPT) and cetrimide . The pattern of susceptibility was similar to that observed with the isothiazolone biocides . Upon removal of biocide, the observed MIC did not return to the original pre-exposure value . The onset and development of resistance was accompanied by the loss of T-OMP from outer membrane profiles, which suggests that this is a non-specific membrane channel whose production within the cell is sensitive to biocide presence . The T-OMP reappeared when the cells were passaged in the absence of pyrithione . Cross-resistance studies indicated that induced resistance to one biocide yields partial resistance towards other members of the group and the positive control . CONCLUSIONS: These results indicate that the pyrithione biocides have similar susceptibility profiles in Ps . aeruginosa to those exhibited by the isothiazolones, but that the acquired changes in susceptibility to the pyrithiones is largely irreversible . SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicates that acquired susceptibility changes towards sub-MICs of selected biocides are multifactorial in nature. J Appl Microbiol, 2002, 92(4), 618 - 23 Factors influencing the susceptibility of Gram-negative bacteria to toluidine blue O-mediated lethal photosensitization; Komerik N et al.; AIMS: Bacteria can be killed by red light in the presence of a photosensitizer . The purpose of this study was to evaluate the effect of physiological and environmental factors on the susceptibility of some bacteria associated with oral infections in immunocompromised patients to killing by the photosensitizer toluidine blue O (TBO) . METHODS AND RESULTS: Suspensions of Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae in human saliva, horse serum or saline were exposed to light from a helium/ neon laser in the presence of TBO . Additional suspensions at various growth phases and pHs were treated in an identical manner . Survivors were enumerated by viable counting . All three species were susceptible to lethal photosensitization under all of the conditions tested . The presence of serum and, to a lesser extent, saliva decreased the level of kill attained . The bactericidal effect was reduced at acid pHs but was unaffected by the growth phase of the organism . CONCLUSIONS: The composition and pH of the fluid in which bacteria are suspended influenced the effectiveness of TBO-mediated lethal photosensitization, whereas killing was unaffected by the growth phase of the organism . SIGNIFICANCE AND IMPACT OF THE STUDY: Environmental factors operating in the mouths of patients with mucositis could reduce the effectiveness of TBO-mediated lethal photosensitization of bacteria associated with this condition. Plast Reconstr Surg, 2002 Apr 1, 109(4), 1338 - 43 Improvement in burn wound infection and survival with antimicrobial peptide D2A21 (Demegel); Chalekson CP et al.; Naturally occurring antimicrobial peptides have been discovered in both plants and animals . Many of these peptides demonstrate impaired activity or cytotoxicity when applied exogenously . Synthetically engineered antimicrobial peptides have been designed to increase potency and activity against bacteria and fungus yet remain noncytotoxic . The antimicrobial peptide D2A21 (Demegel) has already demonstrated significant activity in vitro against many common hospital pathogens . The purpose of this study was to evaluate the effects of D2A21 in an in vivo infected burn-wound model, examining both quantitative cultures of the wound and survival of the animal . Forty-four Wistar rats were subjected to a 23 percent total body surface area scald burn . Pseudomonas aeruginosa was administered topically with 108 organisms and wounds were then evaluated at day 1, 2, or 3 for eschar and subeschar muscle quantitative culture . The experimental group was treated daily with 1.5% topical D2A21 . The control group was treated with control gel . A second group of Wistar rats (n = 14) were burned and given a 107 inoculum of the same Pseudomonas and evaluated to 14 days for survival and weight changes . This group was subdivided into rats receiving either topical D2A21 or control base daily . The quantitative biopsy results demonstrated that D2A21-treated wounds had no bacterial growth in burn eschar at day 2 or 3, whereas control animals demonstrated growth at greater than 105 organisms by day 2 . Subeschar muscle cultures also demonstrated significantly less bacterial invasion compared with controls on each day tested . D2A21-treated animals had an 85.7 percent survival compared with 0 percent survival in controls . Furthermore, the D2A21-treated groups demonstrated maintenance of body weights, whereas controls had significant weight loss with time . In conclusion, D2A21 demonstrates significant antibacterial activity against Pseudomonas, sterilizing burn eschar and decreasing subeschar bacterial load, allowing for a markedly significant improvement in survival in this infected burn-wound model. Curr Opin Infect Dis, 2002 Apr, 15(2), 175 - 82 Cystic fibrosis; Brennan AL et al.; Cystic fibrosis is the most common lethal inherited disorder with autosomal recessive inheritance . Major progress has been made in understanding the molecular mechanisms leading to increased susceptibility to Pseudomonas aeruginosa colonization . Persistent respiratory infection with P . aeruginosa leads to progressive pulmonary inflammation and is the major cause of morbidity and mortality . Treatment and prophylaxis of respiratory infection has improved the median survival and quality of life of cystic fibrosis patients . In the future, treatment of the underlying genetic defect may be possible. Curr Opin Infect Dis, 2001 Aug, 14(4), 403 - 7 Pseudomonas aeruginosa infections in cancer patients: have they gone away? Bodey GP. Pseudomonas aeruginosa infection continues to be a threat to cancer patients, especially if they are neutropenic . As many as 50% of infections are community acquired . Prompt, effective therapy results in cures in about 80% of patients, although the presence of shock or pneumonia indicates a poor prognosis . Antibiotic resistance is an increasing problem. Biophys J, 2002 May, 82(5), 2758 - 66 Role of the coordinating histidine in altering the mixed valency of Cu(A): an electron nuclear double resonance-electron paramagnetic resonance investigation; Lukoyanov D et al.; The binuclear Cu(A) site engineered into Pseudomonas aeruginosa azurin has provided a Cu(A)-azurin with a well-defined crystal structure and a CuSSCu core having two equatorial histidine ligands, His120 and His46 . The mutations His120Asn and His120Gly were made at the equatorial His120 ligand to understand the histidine-related modulation to Cu(A), notably to the valence delocalization over the CuSSCu core . For these His120 mutants Q-band electron nuclear double resonance (ENDOR) and multifrequency electron paramagnetic resonance (EPR) (X, C, and S-band), all carried out under comparable cryogenic conditions, have provided markedly different electronic measures of the mutation-induced change . Q-band ENDOR of cysteine C(beta) protons, of weakly dipolar-coupled protons, and of the remaining His46 nitrogen ligand provided hyperfine couplings that were like those of other binuclear mixed-valence Cu(A) systems and were essentially unperturbed by the mutation at His120 . The ENDOR findings imply that the Cu(A) core electronic structure remains unchanged by the His120 mutation . On the other hand, multifrequency EPR indicated that the H120N and H120G mutations had changed the EPR hyperfine signature from a 7-line to a 4-line pattern, consistent with trapped-valence, Type 1 mononuclear copper . The multifrequency EPR data imply that the electron spin had become localized on one copper by the His120 mutation . To reconcile the EPR and ENDOR findings for the His120 mutants requires that either: if valence localization to one copper has occurred, the spin density on the cysteine sulfurs and the remaining histidine (His46) must remain as it was for a delocalized binuclear Cu(A) center, or if valence delocalization persists, the hyperfine coupling for one copper must markedly diminish while the overall spin distribution on the CuSSCu core is preserved. Biophys J, 2002 May, 82(5), 2645 - 51 Studies of Pseudomonas aeruginosa azurin mutants: cavities in beta-barrel do not affect refolding speed; Pozdnyakova I et al.; Pseudomonas aeruginosa azurin is a blue-copper protein with a Greek-key fold . Removal of copper produces an apoprotein with the same structure as holoazurin . To address the effects on thermodynamic stability and folding dynamics caused by small cavities in a beta-barrel, we have studied the behavior of the apo-forms of wild-type and two mutant (His-46-Gly and His-117-Gly) azurins . The equilibrium- and kinetic-folding and unfolding reactions appear as two-state processes for all three proteins . The thermodynamic stability of the two mutants is significantly decreased as compared with the stability of wild-type azurin, in accord with cavities in or near the hydrophobic interior having an overall destabilizing effect . Large differences are also found in the unfolding rates: the mutants unfold much faster than wild-type azurin . In contrast, the folding-rate constants are almost identical for the three proteins and closely match the rate-constant predicted from the native-state topology of azurin . We conclude that the topology is more important than equilibrium stability in determining the folding speed of azurin. Appl Biochem Biotechnol, 2001 Spring, 91-93, 459 - 67 Production of biosurfactant from a new and promising strain of Pseudomonas aeruginosa PA1; Santa Anna LM et al.; The Pseudomonas aeruginosa PA1 strain, isolated from the water of oil production in Sergipe, Northeast Brazil, was evaluated as a potential rhamnolipid type of biosurfactant producer . The production of biosurfactants was investigated using different carbon sources (n-hexadecane, paraffin oil, glycerol, and babassu oil) and inoculum concentrations (0.0016-0.008 g/L) . The best results were obtained with glycerol as the substrate and an initial cell concentration of 0.004 g/L . A C:N ratio of 22.8 led to the greatest production of rhamnolipids (1700 mg/L) and efficiency (1.18 g of rhamnolipid/g of dry wt). Presse Med, 2002 Mar 23, 31(11), 498 - 502 {Risk factors for the acquisition of Pseudomonas aeruginosa in a surgical intensive care unit}; Duchamp CB et al.; OBJECTIVES: To investigate the risk factors for the acquisition (infection and/or colonization) of Pseudomonas aeruginosa, which is frequently associated with nosocomial infections, in a surgical intensive care unit in Dijon . METHOD: A retrospective case-control study was performed on 57 cases matching with 114 controls, between December 1996 and February 1999 . The statistical method used was a conditional multiple logistic regression model . RESULTS: Three groups of variables were studied (patient characteristics--invasive procedures--previous administration of antibiotics) . The multiple logistic regression analysis confirmed 3 risk factors: duration of sedation, infection with another bacteria and cranio-encephalic trauma . These factors are commonly involved in nosocomial infections . CONCLUSION: This study confirms the interest of infection control measures and the prevention of nosocomial infections, especially in cranio-encephalic trauma . The hypothetical relationship between acquisition of Pseudomonas aeruginosa and previous administration of antibiotics was not confirmed . A more powerful study would perhaps specify this relationship. J Biol Chem, 2002 Jul 5, 277(27), 24490 - 8 Epub 2002 Apr 16. Pseudomonas aeruginosa aspartate transcarbamoylase . Characterization of its catalytic and regulatory properties; Vickrey JF et al.; Aspartate transcarbamoylase from Pseudomonadaceae is a class A enzyme consisting of six copies of a 36-kDa catalytic chain and six copies of a 45-kDa polypeptide of unknown function . The 45-kDa polypeptide is homologous to dihydroorotase but lacks catalytic activity . Pseudomonas aeruginosa aspartate transcarbamoylase was overexpressed in Escherichia coli . The homogeneous His-tagged protein isolated in high yield, 30 mg/liter of culture, by affinity chromatography and crystallized . Attempts to dissociate the catalytic and pseudo-dihydroorotase (pDHO) subunits or to express catalytic subunits only were unsuccessful suggesting that the pDHO subunits are required for the proper folding and assembly of the complex . As reported previously, the enzyme was inhibited by micromolar concentrations of all nucleotide triphosphates . In the absence of effectors, the aspartate saturation curves were hyperbolic but became strongly sigmoidal in the presence of low concentrations of nucleotide triphosphates . The inhibition was unusual in that only free ATP, not MgATP, inhibits the enzyme . Moreover, kinetic and binding studies with a fluorescent ATP analog suggested that ATP induces a conformational change that interferes with the binding of carbamoyl phosphate but has little effect once carbamoyl phosphate is bound . The peculiar allosteric properties suggest that the enzyme may be a potential target for novel chemotherapeutic agents designed to combat Pseudomonas infection. Antimicrob Agents Chemother, 2002 May, 46(5), 1288 - 94 Characterization and movement of the class 1 integron known as Tn2521 and Tn1405; Partridge SR et al.; Two putative transposons, Tn2521 and Tn1405, carrying determinants for the PSE-4 beta-lactamase and for resistance to streptomycin, spectinomycin, and sulfonamides were previously isolated from the chromosome of Pseudomonas aeruginosa Dalgleish . Detailed mapping and determination of the complete sequence of Tn2521 revealed that it is a class 1 integron, here renamed In33, with a backbone structure identical to that of In4 from Tn1696 . In33 contains two gene cassettes, blaP1 and aadA1, replacing the aacC1-orfE-aadA2-cmlA1 cassette array in In4 . Although In33 does not include any transposition genes, movement of In33 (Tn2521) targeted to a single location in the IncP-1 plasmid R18-18 has been reported previously (M . I . Sinclair and B . W . Holloway, J . Bacteriol . 151:569-579, 1982) . A 5-bp duplication of the target, which lies within the res site recognized by the ParA resolvase of R18-18, was present, indicating that the mechanism of movement was transposition . Together, these data indicate that class 1 integrons that are defective in self-transposition can move under appropriate circumstances . The Tn1405 isolate studied was found to represent only the cassette array of In33, which had replaced the cassette array in the recipient plasmid R388, probably by homologous recombination. Neurochem Res, 2002 Apr, 27(4), 305 - 12 A new hypothalamic polypeptide is a regulator of myelopoiesis; Galoyan AA et al.; The effect of hypothalamic proline-rich polypeptide (PRP) against Pseudomonas aeruginosa infection in BALB/c mice with leukopenia was investigated . Mice were treated with cyclophosphamide (CPA) and were then injected with PRP 24 h after CPA treatment . The lethal doses of P . aeruginosa were injected to mice when the number of peripheral blood leukocytes reached a nadir on day 5 after CPA administration . The administration of PRP significantly increased the survival of infected mice, and had a pronounced protective effect during the period of development of the infection . The number of bacteria in internal organs of PRP-treated mice was significantly lower than that in control mice . In PRP-treated mice, the neutrophil levels in peripheral blood started to increase 7 days after CPA administration and were consistently higher, and they were more mature than those in controls . Our results may indicate the ability of PRP to stimulate recovery of myelopoiesis and enhance mature neutrophil function. J Infect Chemother, 2002 Mar, 8(1), 99 - 102 Destructive pulmonary embolism in a patient with community-acquired staphylococcal bacteremia; Miyashita T et al.; We report a 17-year-old man with destructive pulmonary embolism caused by Staphylococcus aureus bacteremia . The patient was not immunocompromised and had neither underlying diseases nor risk factors, such as concomitant influenza viral infection, which exacerbate staphylococcal infections . The rapid and extensive progression of pulmonary involvement in all lung fields make this a rare case; there have been few reports in the literature describing a similar radiographic appearance in patients with community-acquired staphylococcal bacteremia . In-vitro studies did not demonstrate the production of enterotoxins or toxic shock syndrome toxin 1 (TSST-1) by the isolated strain, but genetic analysis detected Panton-Valentine leukocidine gene from the strain . Subsequent empyema with bilateral pneumothorax was prolonged because of superinfection with both methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa . Optional surgical treatments, including thoracostomy and thoracopneumoplasty, finally improved his condition. J Infect Chemother, 2002 Mar, 8(1), 37 - 42 Effectiveness of fosfomycin combined with other antimicrobial agents against multidrug-resistant Pseudomonas aeruginosa isolates using the efficacy time index assay; Okazaki M et al.; We investigated the effectiveness of fosfomycin combined with other antibiotics, such as piperacillin, cefepime, ceftazidime, imipenem, meropenem, aztreonam, gentamicin, or levofloxacin, against 30 Pseudomonas aeruginosa strains, including multidrug-resistant strains, isolated from clinical specimens, using the efficacy time index (ETI) assay . The assay refers to the result of pharmacokinetics obtained from adult men volunteers, and yields an ETI to evaluate the effect of a combination of antimicrobial agents . With the ETI, based on serum concentration 3 h after the administration of two antimicrobial agents, the effectiveness of antimicrobial combinations was evaluated as follows: poor, ETI < 0.5; fair, 0.5 < or = ETI < 1; good, 1 < or = ETI < 8; and excellent, ETI > or = 8 . The combination of fosfomycin and cefepime (efficacy rate {excellent plus good}, 76.7%) and fosfomycin/aztreonam (efficacy rate, 76.7%) appeared to be the most effective, followed by fosfomycin/meropenem (efficacy rate, 76.6%), fosfomycin/imipenem (efficacy rate, 73.3%), fosfomycin/ceftazidime (efficacy rate, 70%), fosfomycin/gentamicin (efficacy rate, 70%), fosfomycin/piperacillin (efficacy rate, 66.7%), and fosfomycin/levofloxacin (efficacy rate, 66.7%) . Fosfomycin/cefepime, fosfomycin/aztreonam, and fosfomycin/meropenem may be clinically useful in selected patients, particularly for P . aeruginosa . The ETI assay provided information on the minimum inhibitory concentration (MIC) of many pairs of combined antimicrobial agents simultaneously . The ETI assay may be a useful technique with which to investigate the effect of combinations of antimicrobial agents against P . aeruginosa, including multidrug-resistant strains. Am J Respir Crit Care Med, 2002 Apr 15, 165(8), 1176 - 81 Prolonged inflammatory response to acute Pseudomonas challenge in interleukin-10 knockout mice; Chmiel JF et al.; Cystic fibrosis (CF) lung disease is characterized by a neutrophilic infiltrate that is excessive relative to the burden of infection . Decreased interleukin-10 in CF airways may impair proper termination of inflammation, leading to persistence of neutrophils after acute infections have been cleared . This could explain reports of lung inflammation in the absence of bacteria in infants with CF . We evaluated the kinetics of inflammation after transient Pseudomonas aeruginosa challenge in IL-10 knockout (KO) and wild-type (WT) mice . Both types of mice cleared the infection by Day 6 (p > or = 0.29) . However, IL-10 KO mice had more neutrophils in bronchoalveolar lavage fluid than did WT mice on Days 4 (p < 0.0001), 6 (p < 0.0001), and 8 (p = 0.042) . IL-10 KO mice had high concentrations of proinflammatory cytokines in BAL on Days 2 and 4, with some cytokines detectable on Days 6 and 8, whereas cytokines in BAL from WT mice were greatest on Day 2 and undetectable by Day 4 . Moreover, IL-10 KO mice failed to regenerate IkappaBalpha once degraded and subsequently had prolonged activation of NF-kappaB . These data suggest that IL-10 deficiency contributes to prolonged inflammatory responses early in CF, when infection may be transient. Zhonghua Yan Ke Za Zhi, 2002 Jan, 38(1), 8 - 12 {The variance of pathogenic organisms of purulent ulcerative keratitis}; Zhang W et al.; OBJECTIVE: To identify the variance of pathogens of purulent keratitis and their resistance patterns to antibiotics . METHODS: From January 1995 to October 2000, all patients with suspected infectious corneal ulcer were examined by bacterial, fungal and Acanthameoba culture . The results of microorganism-culture were compared with those in literature . RESULTS: Of the specimens in 1 430 cases, there were 790 cases (55.2%) with positive culture including bacterial isolates in 258 cases (18.0%), fungal isolates in 498 cases (34.8%) and parasites in 34 cases (2.4%) . The Staphylococcus aureous and Pseudomonas aeruginosa that had markedly declined since 1980s represented 6.2% and 21.7% of bacterial isolates respectively . However, the opportunity organism such as Staphylococcus epidermidis represented 27.5%, a tendency of gradual increase . The most common fungal pathogen was fusarium spp that represented 64.5% of all positive fungal cultures, and Aspergillus spp (13.6%) occupied the second place . The resistance of the ocular bacteria to fluoroquinolones gradually increased . Although the Pseudomonas aeruginosa was resistant to gentamycin in 36.2%, it was almost no resistance to tobramycin (3.4%) . The fusarium spp was shown to be resistant to a number of the anti-fungal agents, but it is sensitive to natamycin . CONCLUSION: The survey of pathogens in purulent ulcerative keratitis and their resistance patterns to antibiotics helps in clinical treatment. Biochem J, 2002 Aug 1, 365(Pt 3), 731 - 8 Support for a three-dimensional structure predicting a Cys-Glu-Lys catalytic triad for Pseudomonas aeruginosa amidase comes from site-directed mutagenesis and mutations altering substrate specificity; Novo C et al.; The aliphatic amidase from Pseudomonas aeruginosa belongs to the nitrilase superfamily, and Cys(166) is the nucleophile of the catalytic mechanism . A model of amidase was built by comparative modelling using the crystal structure of the worm nitrilase-fragile histidine triad fusion protein (NitFhit; Protein Data Bank accession number 1EMS) as a template . The amidase model predicted a catalytic triad (Cys-Glu-Lys) situated at the bottom of a pocket and identical with the presumptive catalytic triad of NitFhit . Three-dimensional models for other amidases belonging to the nitrilase superfamily also predicted Cys-Glu-Lys catalytic triads . Support for the structure for the P . aeruginosa amidase came from site-direct mutagenesis and from the locations of amino acid residues that altered substrate specificity or binding when mutated. Vet Radiol Ultrasound, 2002 Mar-Apr, 43(2), 178 - 82 An infected hip prosthesis in a dog diagnosed with a 99mTc-ciprofloxacin (infecton) scan; Peremans K et al.; This case report describes the use of the 99mTc-labeled radiopharmaceutical ciprofloxacin (Infecton) in a case of hip prosthesis loosening in a dog . Serial planar radiographs were not conclusive, and culture of the synovial fluid was negative . Antibiotic treatment did not result in improvement of the lameness . Scintigraphy was performed with 99-Tc-Infecton, a tracer claimed to be specific for infection . Antibiotic treatment was interrupted 6 weeks prior to the examination . Planar and tomographic images at 3 h and at 24 h postinjection showed increased activity along the acetabulum and the proximal femoral bone surrounding the femoral prosthesis, indicating focal infection . Bacteriology performed after removal of the implant revealed Pseudomonas aeruginosa. Saudi Med J, 2002 Apr, 23(4), 396 - 9 An in-vitro study of the effects of various disinfectants on prosthetic and surface materials; Bahannan SA et al.; OBJECTIVE: This study assessed the effect of various disinfectants on several contaminated prosthetic and surface-covering materials . METHODS: The efficacy of 6 disinfectants used at King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia, on prosthetic and surface-covering materials, irreversible hydrocolloid and elastomer impression materials, wax, acrylic resin, metal, bench-covering material, and floor carpet . These materials were contaminated with Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus . Counts of viable bacteria on the materials was determined by incubated replica plating on blood agar plates at 5 minute intervals . A 3 way non parametric analysis of variance was used to evaluate the main effects and interactions of the disinfectants, bacteria, and materials . RESULTS: Statistical analysis showed that material, type of disinfectant, and interactions between material and bacteria were significant . Carpet has a significantly higher bacterial count than many other items (P < 0.0001) such as acrylic resin, irreversible hydrocolloid, chrome-cobalt casting, and laminated bench surfaces . CONCLUSION: Quaternary ammonia compound and the tertiary ammonia phenol were the most effective disinfectants . Efficacy of the disinfectant depends partly on the bacteria used for contamination . Carpets in dental clinics showed high potential to retain microorganisms. J Pediatr, 2002 Mar, 140(3), 299 - 305 Antibiotic prophylaxis in infants and young children with cystic fibrosis: a randomized controlled trial; Stutman HR et al.; OBJECTIVES: To evaluate whether antistaphylococcal prophylaxis in infants and young children with cystic fibrosis (CF) would suppress the acquisition of Staphylococcus aureus and delay the onset of the manifestations of bronchopulmonary disease . STUDY DESIGN: A 7-year, multicenter, double-blind, placebo-controlled study of continuous antistaphylococcal therapy . Otherwise healthy children <2 years of age with CF were randomly assigned to be treated with daily cephalexin (80-100 mg/kg/day) or placebo . Clinical, microbiologic, laboratory, radiographic, and anthropometric outcomes were evaluated . RESULTS: Of 209 children enrolled, 119 completed a 5- to 7-year course of therapy . Mean age at enrollment was 15.6 and 14.1 months in the cephalexin and placebo groups, respectively . Respiratory cultures from children treated with cephalexin were significantly less likely to be positive for S aureus (6.0% vs 30.4%; P <.001) . They were, however, much more likely to be positive for Pseudomonas aeruginosa (25.6% vs 13.5%; P <.009) . These differences became apparent in the first year after enrollment and persisted over the duration of the study . In contrast to these microbiologic differences, there were no differences in clinical outcome measures, including radiographic (Brasfield score, 23.4 vs 23.2) or anthropometric scores or pulmonary function . CONCLUSIONS: Although long-term prophylaxis with cephalexin successfully delayed the acquisition of S aureus, it enhanced colonization with P aeruginosa and did not lead to clinically significant improvement in major health outcomes . These data do not support routine antistaphylococcal prophylaxisin otherwise healthy infants and young children with CF. Mol Microbiol, 2002 Mar, 43(6), 1641 - 50 The mismatch repair system (mutS, mutL and uvrD genes) in Pseudomonas aeruginosa: molecular characterization of naturally occurring mutants; Oliver A et al.; We have recently described the presence of a high proportion of Pseudomonas aeruginosa isolates (20%) with an increased mutation frequency (mutators) in the lungs of cystic fibrosis (CF) patients . In four out of 11 independent P . aeruginosa strains, the high mutation frequency was found to be complemented with the wild-type mutS gene from P . aeruginosa PAO1 . Here, we report the cloning and sequencing of two additional P . aeruginosa mismatch repair genes and the characterization, by complementation of deficient strains, of these two putative P . aeruginosa mismatch repair genes (mutL and uvrD) . We also describe the alterations in the mutS, mutL and uvrD genes responsible for the mutator phenotype of hypermutable P . aeruginosa strains isolated from CF patients . Seven out of the 11 mutator strains were found to be defective in the MMR system (four mutS, two mutL and one uvrD) . In four cases (three mutS and one mutL), the genes contained frameshift mutations . The fourth mutS strain showed a 3.3 kb insertion after the 10th nucleotide of the mutS gene, and a 54 nucleotide deletion between two eight nucleotide direct repeats . This deletion, involving domain II of MutS, was found to be the main one responsible for mutS inactivation . The second mutL strain presented a K310M mutation, equivalent to K307 in Escherichia coli MutL, a residue known to be essential for its ATPase activity . Finally, the uvrD strain had three amino acid substitutions within the conserved ATP binding site of the deduced UvrD polypeptide, showing defective mismatch repair activity . Interestingly, cells carrying this mutant allele exhibited a fully active UvrABC-mediated excision repair . The results shown here indicate that the putative P . aeruginosa mutS, mutL and uvrD genes are mutator genes and that their alteration results in a mutator phenotype. Chest, 2002 Apr, 121(4), 1149 - 54 Noninvasive positive-pressure ventilation vs . conventional oxygen supplementation in hypoxemic patients undergoing diagnostic bronchoscopy; Antonelli M et al.; OBJECTIVE: We have reported previously on the use of noninvasive positive-pressure ventilation (NPPV) to assist spontaneous breathing in high-risk hypoxemic patients (i.e., PaO(2)/fraction of inspired oxygen {FIO(2)} ratio, < or = 100) who are undergoing diagnostic fiberoptic bronchoscopy (FOB) . The efficacy of this intervention in patients with less severe forms of hypoxemia (i.e., PaO(2)/FIO(2) ratio, < 200) is unknown . PATIENTS AND METHODS: Twenty-six patients with PaO(2)/FIO(2) ratios < or = 200 who required bronchoscopic BAL for suspected nosocomial pneumonia were entered into the study . Thirteen patients were randomized during FOB to receive NPPV, and 13 patients were randomized to receive conventional oxygen supplementation by Venturi mask . The primary end points were changes in the PaO(2)/FIO(2) ratio during FOB and within 60 min of terminating the procedure . RESULTS AND OUTCOME: At study entry, the two groups were similar in terms of age, simplified acute physiologic score II values, and cardiorespiratory parameters . During FOB, the mean (+/- SD) PaO(2)/FIO(2) ratio increased by 82% in the NPPV group (261 +/- 100 vs 139 +/- 38; p < 0.001) and decreased by 10% in the conventional oxygen supplementation group (155 +/- 24 to 139 +/- 38; p = 0.23) . Sixty minutes after undergoing FOB, the NPPV group had a higher mean PaO(2)/FIO(2) ratio (176 +/- 62 vs 140 +/- 38; p = 0.09), a lower mean heart rate (91 +/- 18 vs . 108 +/- 15 beats/min; p = 0.02), and no reduction in mean arterial pressure in comparison to a 15% decrease from the baseline in the control group . One patient in the NPPV group and two patients in the control group required nonemergent intubation . Major bacterial isolates included Staphylococcus aureus (7 of 30 isolates; 23%) and Pseudomonas aeruginosa (12 of 30 isolates; 40%) . CONCLUSION: In patients with severe hypoxemia, NPPV is superior to conventional oxygen supplementation in preventing gas-exchange deterioration during FOB with better hemodynamic tolerance. Curr Pharm Des, 2002, 8(9), 695 - 702 Tailoring an antibacterial peptide of human lysosomal cathepsin G to enhance its broad-spectrum action against antibiotic-resistant bacterial pathogens; Shafer WM et al.; Neutrophils contain several cationic antimicrobial proteins or peptides (CAPs) that exert antibiotic-like action against bacteria . These host-derived antibiotics kill susceptible bacteria by oxygen-independent mechanisms . Considerable interest in their activity has been generated in recent years due not only to their likely important role in innate host defense against infection, but also their possible use as therapeutic agents in treating infections caused by antibiotic-resistant pathogens . We have studied the antibacterial properties of human lysosomal cathepsin G (cat G) . This highly cationic serine protease contains at least three antibacterial regions that by themselves can exert antibacterial action against Gram-negative bacteria, such as Pseudomonas aeruginosa . Only one of these peptides, defined by residues 117-136 of full-length cat G, has bactericidal action against Gram-positive pathogens, such as Staphylococcus aureus . Due to the broad-spectrum antibacterial action of this peptide, we have sought to define the amino acids within its primary sequence required for this activity and have developed variants with improved activity . This review emphasizes the importance of both cationicity and hydrophobicity as necessary characteristics for the antibacterial action of CAPs . It also proposes the strategy that naturally occurring large human CAPs can be dissected to smaller CAPs and then modified to enhance their activity in vitro . This approach could prove beneficial to those interested in developing antimicrobial peptides as therapeutic agents. Microbiol Immunol, 2002, 46(2), 75 - 81 Antibacterial properties of antimicrobial-finished textile products; Takai K et al.; The antibacterial properties of five kinds of antimicrobial-finished textile products (AFTPs) were examined against Staphylococcus aureus, including methicillin-resistant (MRSA) strains and Pseudomonas aeruginosa, under wet and dry conditions . Textile products containing Ag . Zn . ammonium Zeolite and chitosan were found to be effective against methicillin-sensitive S . aureus (MSSA) for up to 6 hr of incubation under wet and dry conditions, and effective against MRSA for up to 24 hr of incubation only under wet conditions . Under dry conditions, however, all AFTPs were ineffective against one MRSA strain . When organic matter was added to the incubation mixture, textile products containing Ag . Zn . ammonium Zeolite and chitosan still showed antibacterial activities, but not as strongly . The results of this study suggested the following: (1) There are differences in antibacterial properties among commercially available AFTPs; (2) Determining effectiveness requires several hours of incubation; (3) Water content as an environmental factor can affect effectiveness; and (4) Some bacterial species and strains are not affected by AFTPs . The antibacterial properties of AFTPs in the clinical setting may be of limited value. Cell Biochem Biophys, 2002, 36(1), 19 - 40 A pH dependence study on the unfolding and refolding of apoazurin: comparison with Zn(II) azurin; Hansen JE et al.; Azurin, a small blue copper protein from the bacterial species Pseudomonas aeruginosa, is mostly a beta-sheet protein arranged into a single domain . Previous folding studies have shown that the equilibrium denaturation of the holoprotein follows a two-state process; however, upon removal of the copper, the denaturation had been reported to follow a three-state process . The two unfolding transitions measured for apoazurin had been thought to arise from two different folding domains . However, in the present work, we found that the denaturation of apoazurin occurs over a single transition and we determined the folding free energy to be -27.8 +/- 2.4 kJ mol(-1) . From this measurement along with measurements previously reported for the unfolding of the holoazurin, we were able to determine that Cu(II) and Cu(I) stabilize the native structure by 25.1 +/- 6.9 kJ/mol and 12.9 +/- 8.1 kJ/mol, respectively . It is our contention that the second transition displayed in the denaturation curves previously reported for apoazurin arise from protein heterogeneity-in particular, from the presence of Zn(II) azurin . We extended our investigation into the denaturation of Zn(II) azurin at pH 6.0 and 7.5 . The equilibrium denaturation studies show that the zinc ion significantly stabilizes the native-state structure at pH 7.5 and very little at the lower pH . We attribute the decrease in the stabilizing effect of the zinc ion with decreasing pH to the protonation of two histidinyl side chains . When protonated the ligands, His 46 and His 117, are incapable of binding a metal ion . Further, comparing the denaturation curves of Zn(II) azurin measured by circular dichroism with those measured by fluorescence indicates that the denaturation of Zn(II) azurin is far less simple than the denaturation of apoazurin. J Biol Chem, 2002 Jun 14, 277(24), 21768 - 75 Epub 2002 Apr 05. Salicylate biosynthesis in Pseudomonas aeruginosa . Purification and characterization of PchB, a novel bifunctional enzyme displaying isochorismate pyruvate-lyase and chorismate mutase activities; Gaille C et al.; Isochorismate pyruvate-lyase (IPL), the second enzyme of pyochelin biosynthesis and the product of the pchB gene, was purified to homogeneity from Pseudomonas aeruginosa . In the reaction catalyzed by this enzyme, isochorismate --> salicylate + pyruvate, no cofactors appear to be required . At the pH optimum (pH 6.8), the enzyme displayed Michaelis-Menten kinetics, with an apparent K(m) of 12.5 microm for isochorismate and a kcat of 106 min(-1), calculated per monomer . The native enzyme behaved as a homodimer, as judged by molecular sieving chromatography, electrophoresis under nondenaturing conditions, and cross-linking experiments . PchB has approximately 20% amino acid sequence identity with AroQ-class chorismate mutases (CMs) . Chorismate was shown to be converted to prephenate by purified PchB in vitro, with an apparent K(m) of 150 microm and a kcat of 7.8 min(-1) . An oxabicyclic diacid transition state analog and well characterized inhibitor of CMs competitively inhibited both IPL and CM activities of PchB . Moreover, a CM-deficient Escherichia coli mutant, which is auxotrophic for phenylalanine and tyrosine, was functionally complemented by the cloned P . aeruginosa pchB gene for growth in minimal medium . A mutant form of PchB, in which isoleucine 88 was changed to threonine, had no detectable IPL activity, but retained wild-type CM activity . In conclusion, the 11.5-kDa subunit of PchB appears to contain a single active site involved in both IPL and CM activity. Chem Phys Lipids, 2002 Feb, 114(2), 181 - 91 Synthesis of a novel fluorescent ceramide analogue and its use in the characterization of recombinant ceramidase from Pseudomonas aeruginosa PA01; Nieuwenhuizen WF et al.; Ceramidase (CDase) hydrolyses the N-acyl linkage of the sphingolipid ceramide . We synthesized the non-fluorescent ceramide analogue (4E,2S,3R)-2-N-(10-pyrenedecanoyl)-1,3,17-trihydroxy-17-(3,5-dinitrobenzoyl)-4-heptadecene (10) that becomes fluorescent upon hydrolysis of its N-acyl bond . This novel substrate was used to study several kinetic aspects of the recombinant CDase from the pathogenic bacterium Pseudomonas aeruginosa PA01 . Maximum CDase activity was observed above 1.5 microM substrate, with an apparent K(m) of 0.5+/-0.1 microM and a turnover of 5.5 min(-1) . CDase activity depends on divalent cations without a strong specificity . CDase is inhibited by sphingosine and by several sphingosine analogues . The lack of inhibition by several mammalian CDase inhibitors such as D-erythro-MAPP, L-erythro-MAPP or N-oleoylethanolamine points to a novel active site and/or substrate binding region . The CDase assay described here offers the opportunity to develop and screen for specific bacterial CDase inhibitors of pharmaceutical interest. Presse Med, 2002 Mar 9, 31(9), 393 - 9 {Are the principles of treatment of chronic osteitis applicable to the diabetic foot?}; Senneville E et al.; OBJECTIVE: The interest of the management of bone infections in the diabetic foot, inspired by the recommendations for the treatment of chronic osteitis, was assessed in this study . METHODS: Twenty bone infections in 17 diabetic patients with moderate to mild infections of the feet were confirmed by the results of X-ray and/or scintigraphic studies and bone surgery biopsy cultures revealing one or more bacteria sensitive to standard osteitis treatment (rifampicine + fluoroquinolone) . The patients had received this treatment per os for a median duration of 6 months (3 to 10 months) . Clinical follow-up was carried out during a consultation at 1, 3 and 6 months during treatment and then by telephone every six months after the end of treatment . Clinical success was defined as the disappearance of any local sign of infection and by the absence of relapse during the post-treatment follow-up period . The evolution of the bone infection was also assessed by the results of a control conducted 3 to 6 months after initiation of the antibiotic treatment . RESULTS: At the end of the treatment, all signs of infection had disappeared in 15/17 patients (88.2%) and no relapse had occurred in 14 (82.3%) patients at the end of a median post-treatment period of 22 months (12 to 41 months) . Resection of necrotic bone was performed at the same time as the bone biopsy in 2 patients . The median duration of hospitalisation was of 14 days (3 to 53 days) . During the study, a multi-resistant germ was isolated in 4 patients (1 Pseudomonas aeruginosa, 3 Staphylococcus aureus) . During the post-treatment follow-up, 3 patients dies from causes unrelated to the infection treated . No serious adverse event was reported during the study . DISCUSSION: The results of this pilot study support the rationale of applying the treatment regimens of chronic osteitis to diabetic lesions of the feet, but are only applicable to comparable patients presenting with non-severe lesions of the feet . Moreover, the use of antibiotics with potent selection of resistance such as rifampicine and fluoroquinolone, requires that bone biopsies be taken, which is not easy in all the diabetic foot care centres . We are presently conducting a study to identify the sub-populations of diabetic patients who could benefit from such treatment. Microbiology, 2002 Apr, 148(Pt 4), 1161 - 9 Influence of extracellular polymeric substances on deposition and redeposition of Pseudomonas aeruginosa to surfaces; Gomez-Suarez C et al.; In this study, the role of extracellular polymeric substances (EPS) in the initial adhesion of EPS-producing Pseudomonas aeruginosa SG81 and SG81R1, a non-EPS-producing strain, to substrata with different hydrophobicity was investigated . The release of EPS by SG81 was concurrent with a decrease in surface tension of a bacterial suspension from 70 to 45 mJ m(-2) that was absent for SG81R1 . Both strains adhered faster and in higher numbers to a hydrophilic than to a hydrophobic substratum, but the initial deposition rates and numbers of adhering bacteria in a stationary-end point were highest for the non-EPS-producing strain SG81R1, regardless of substratum hydrophobicity . Both strains adhered less to substrata pre-coated with isolated EPS of strain SG81 . Furthermore, it was investigated whether bacteria, detached by passing air-bubbles, had left behind 'footprints' with an influence on adhesion of newly redepositing bacteria . Redeposition on glass was highest for non-EPS-producing SG81R1 and decreased linearly with the number of times these cycles of detachment and deposition were repeated to become similar to the redeposition of SG81 after six cycles . This indicates that P . aeruginosa SG81 leaves the substratum surface nearly completely covered with EPS after detachment, while SG81R1 releases only minor amounts of surface active EPS, completely covering the substratum after repeated cycles of detachment and adhesion . Atomic force microscopy showed a thick and irregular EPS layer (up to 32 nm) after the first detachment cycle of EPS-producing strain SG81, whereas the putatively non-EPS-producing strain SG81R1 left a 9 nm thin layer after one cycle . X-ray photoelectron spectroscopy indicated that the bacterial footprints consisted of uronic acids, the prevalence of which increased with the number of detachment and deposition cycles. Microbiology, 2002 Apr, 148(Pt 4), 923 - 32 Genetically programmed autoinducer destruction reduces virulence gene expression and swarming motility in Pseudomonas aeruginosa PAO1; Reimmann C et al.; Virulence in the opportunistic human pathogen Pseudomonas aeruginosa is controlled by cell density via diffusible signalling molecules ('autoinducers') of the N-acylhomoserine lactone (AHL) type . Two Bacillus sp . isolates (A23 and A24) with AHL-degrading activity were identified among a large collection of rhizosphere bacteria . From isolate A24 a gene was cloned which was similar to the aiiA gene, encoding an AHL lactonase in another Bacillus strain . Expression of the aiiA homologue from isolate A24 in P . aeruginosa PAO1 reduced the amount of the quorum sensing signal N-oxododecanoyl-L-homoserine lactone and completely prevented the accumulation of the second AHL signal, N-butyryl-L-homoserine lactone . This strongly reduced AHL content correlated with a markedly decreased expression and production of several virulence factors and cytotoxic compounds such as elastase, rhamnolipids, hydrogen cyanide and pyocyanin, and strongly reduced swarming . However, no effect was observed on flagellar swimming or on twitching motility, and aiiA expression did not affect bacterial adhesion to a polyvinylchloride surface . In conclusion, introduction of an AHL degradation gene into P . aeruginosa could block cell-cell communication and exoproduct formation, but failed to interfere with surface colonization. Acta Microbiol Pol, 2001, 50(3-4), 311 - 4 Adherence of Pseudomonas aeruginosa strains to solid surfaces; Wolska K et al.; The aim of this study was to evaluate adherence of 59 strains of Pseudomonas aeruginosa to nitric-acid cleansed glass surfaces . There were differences in adherence between the investigated strains . The highest adherence was noticed among human strains (the average percentage was 13.3 +/- 7.51%) and the lowest adherence was determined among swine strains (the average percentage amounted 6 +/- .37%) . We conclude that strains of Pseudomonas aeruginosa isolated from humans colonise glass surfaces better than strains isolated from animals. Perit Dial Int, 2002 Jan-Feb, 22(1), 27 - 31 Colonization-resistant antimicrobial-coated peritoneal dialysis catheters: evaluation in a newly developed rat model of persistent Pseudomonas aeruginosa peritonitis; Finelli A et al.; OBJECTIVE: Development of a rat model of persistent peritonitis and evaluation of the ability of liposomal ciprofloxacin hydrogel-coated silicone to resist colonization . DESIGN: A newly developed model of persistent Pseudomonas aeruginosa peritonitis to compare the ability of liposomal ciprofloxacin hydrogel (LCH)-coated silicone versus plain silicone for resistance to bacterial colonization . ANIMALS: Male Sprague-Dawley rats . RESULTS: Inoculating the peritoneum of rats with 1 mL 0.5% agar containing 10(6) colony-forming units (cfu)/mL P . aeruginosa in the presence of a plain silicone coupon resulted in persistent peritonitis for at least 7 days . Plain silicone coupons in all 40 rats were colonized (median 2.54 x 10(3) cfu/cm2; range 5.0 x 10(1)-1.0 x 10(6) cfu/cm2) and peritoneal washings were consistently culture-positive . In contrast, the LCH coupons removed after 7 days from the 40 test rats were sterile, as were the peritoneal washings, and there was no evidence of peritonitis . Blood cultures were negative in both groups . CONCLUSIONS: Liposomal ciprofloxacin hydrogel-coated silicone resists colonization in this rat model of persistent P . aeruginosa peritonitis. JAMA, 2002 Apr 3, 287(13), 1716 - 21 Inhibition of intestinal epithelial apoptosis and survival in a murine model of pneumonia-induced sepsis; Coopersmith CM et al.; CONTEXT: Increased intestinal epithelial apoptosis is present in both human autopsy studies and animal models of sepsis . Whether altering gut apoptosis decreases mortality in sepsis induced by pathogenic bacteria outside the gut is unknown . OBJECTIVE: To determine if decreasing levels of intestinal cell death improves survival in a murine model of Pseudomonas aeruginosa pneumonia-induced sepsis . DESIGN AND MATERIALS: Prospective study in which transgenic mice that overexpress the antiapoptotic protein Bcl-2 in their intestinal epithelium (n = 25) and control littermates (n = 26) were subjected to intratracheal injection of P aeruginosa . MAIN OUTCOME MEASURES: Survival at 7 postoperative days, compared between the 2 groups . Secondary outcomes included quantification of gut epithelial apoptosis . RESULTS: Survival in transgenic mice that overexpress Bcl-2 in the intestinal epithelium was 40% (10/25) compared with 4% (1/26) in control littermates 7 days after intratracheal injection of P aeruginosa (P =.001), with differences in survival noted within 24 hours of surgery . Overexpression of Bcl-2 was associated with a decrease in gut epithelial apoptosis demonstrated by active caspase 3 staining, the terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling assay, and hematoxylin-eosin staining . CONCLUSIONS: In this murine model, inhibiting gut epithelial apoptosis by overexpression of Bcl-2 was associated with a survival advantage in P aeruginosa pneumonia-induced sepsis . These results suggest that intestinal epithelial apoptosis may play a role in sepsis-related mortality. Comp Med, 2001 Feb, 51(1), 75 - 9 Therapeutic effect of a pig-derived peptide antibiotic on porcine wound infections; Ceccarelli AV et al.; PURPOSE: We investigated the therapeutic potential of the pig-derived antimicrobial peptide protegrin-1 (PG-1) against porcine skin wounds infected with Pseudomonas aeruginosa . MATERIALS AND METHODS: Using a porcine skin wound model, PG-1 was added to the wound fluid either at the time of P . aeruginosa inoculation, four hours after inoculation or 24 hours after inoculation . Wound fluids were analyzed 20-24 hours later by use of colony-forming unit (CFU) assays, semiquantitative immunoblot analysis for PG-1, and radial diffusion assays (RDA) for residual in vitro activity . RESULTS: Results of the CFU assays indicated a 10,000-fold decrease in the number of bacteria when PG-1 was added at the time of inoculation, a 120-fold decrease when added 4 hours after inoculation and a 10-fold decrease when added 24 hours after inoculation . Results of immunoblot analysis and RDA indicated that PG-1 concentrations for each of the three conditions remained increased in wound fluid 20 to 24 hours after treatment, and correlated with increased residual in vitro antimicrobial activity . CONCLUSIONS: These results document that the endogenous antibiotic PG-1 significantly prevented the colonization of P . aeruginosa in wounds and reduced the in vivo bacterial concentration in established wound infections . Therapeutics used in the same animal species from which they were derived are a promising means for preventing and treating localized infections. Bull Math Biol, 2002 Mar, 64(2), 239 - 59 A mathematical model of partial-thickness burn-wound infection by Pseudomonas aeruginosa: quorum sensing and the build-up to invasion; Koerber AJ et al.; Pseudomonas aeruginosa remains a significant pathogen in burn-wound infection, its pathogenicity being associated with the production of a cocktail of virulence determinants which is regulated by a population-density-dependent mechanism termed quorum sensing . Quorum sensing is effected through the production and binding of signalling molecules . Here we present a mathematical model for the early stages of the infection process by P . aeruginosa in burn wounds which accounts for the quorum sensing system and for the diffusion of signalling molecules in the burn-wound environment . The results of the model and the effects of important parameters are discussed in detail . For example, the effect of the degradation rate of signalling molecules and its significance for anti-signalling therapies is discussed. J Org Chem, 2002 Apr 5, 67(7), 2144 - 51 5-{4-(1-Hydroxyethyl)phenyl}-10,15,20-triphenylporphyrin as a probe of the transition-state conformation in hydrolase-catalyzed enantioselective transesterifications; Ema T et al.; 5-{4-(1-Hydroxyethyl)phenyl}-10,15,20-triphenylporphyrin (1a) and zinc porphyrin 1b were designed and synthesized to experimentally examine the validity of the transition-state model previously proposed for the lipase-catalyzed kinetic resolution of secondary alcohols . The lipases from Pseudomonas cepacia (lipase PS), Candida antarctica (CHIRAZYME L-2), Rhizomucor miehei (CHIRAZYME L-9), and Pseudomonas aeruginosa (lipase LIP) exhibited excellent enantioselectivity (E >100 at 30 degrees C) . Subtilisin Carlsberg from Bacillus licheniformis (ChiroCLEC-BL) also showed high enantioselectivity for 1a (E = 140 at 30 degrees C), and the thermodynamic parameters were determined: DeltaDeltaH = -6.8 +/- 0.8 kcal mol(-1), DeltaDeltaS = -13 +/- 3 cal mol(-1) K(-1) . Lipases and subtilisin showed R- and S-preference for 1, respectively . The mechanisms underlying the experimental observations are explained in terms of the transition-state models . The large secondary alcohol 1 is a powerful tool for investigating the conformation of the transition state of the enzyme-catalyzed reactions . The fact that 1 was resolved with high enantioselectivity strongly suggests that the gauche conformation, but not the anti conformation, is taken in the transition state, in agreement with the transition-state models involving the stereoelectronic effect. Comp Med, 2001 Aug, 51(4), 341 - 8 The pig as a model for excisional skin wound healing: characterization of the molecular and cellular biology, and bacteriology of the healing process; Wang JF et al.; A pig model of wound healing was developed by excision of 2-cm-diameter full thickness skin in young Yorkshire pigs . The results indicated that wound re-epithelialization in this animal model took an average of 20 days . Analysis of cellular change was assessed by use of DNA quantification and determination of apoptotic cells in tissue sections . The results indicate that RNA and DNA contents paralleled each other throughout the healing process, and observed changes in the pattern of RNA and DNA content of the scar tissues were consistent with cell loss due to apoptosis in this model . Expression of mRNA for relevant genes was assessed by use of semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis, using porcine specific primer sets and RNA isolated from normal skin and specimens obtained at various times after wounding . The mRNA values for tumor necrosis factor-alpha (TNF-alpha), connective tissue growth factor (CTGF), insulin-like growth factor II (IGF-II), and decorin were significantly high at specific times after wounding, but mRNA values for the transcription factors (c-fos and c-jun) were significantly decreased . Quantitative bacteriologic results indicated that the total bacterial count in this animal model reached 10(9) colony-forming units (CFU)/g, with the highest value at post-wounding day 7, and Pseudomonas aeruginosa and Staphylocococci aureus were the most common bacteria detected in this model . Further definition of this model should identify unique points in the healing process, and such information could lead to development of therapeutic interventions to improve skin wound healing. East Afr Med J, 2001 Oct, 78(10), 540 - 3 Septicaemia in high risk neonates at a teaching hospital in Ile-Ife, Nigeria; Adejuyigbe EA et al.; OBJECTIVES: To determine the incidence, predisposing factors, clinical features, bacteriological pattern and antibiotic sensitivity in septicaemia in high-risk newborns . DESIGN: A prospective study . SETTING: Neonatal unit, Ife State Hospital, a unit of the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Nigeria . SUBJECTS: All newborns admitted with clinical features and/or risk factors suggestive of neonatal septicaemia from February 1994 to March 1995 . MAIN OUTCOME MEASURES: Culture results and mortality rates . RESULTS: The incidence of neonatal septicaemia among new born was 22.9 per 1000 livebirths . The predisposing perinatal factors were low socio-economic status, lack of antenatal care, maternal peripartum pyrexia and congenital malformations . Gram-positive bacteria were found to be the most prevalent causative organisms (59.4%) . Staphylococcus aureus (36.2%), Pseudomonas aeruginosa (18.8%) and Coagulase negative Staphylococcus (15.9%) were the commonest causes of septicaemia . Meningitis and UTI were associated diagnoses in 16.7% and 18.2% of the septicaemic babies, respectively . The bacterial isolates showed a high degree of in-vitro antimicrobial resistance . However, all the isolates were sensitive to ofloxacin . Amongst the commonly used antibiotics, gentamicin had the lowest resistance . The overall mortality rate was 33.3% . CONCLUSION: Improvement in the socio-economic status of the populace and availability of affordable antenatal care would reduce the incidence of neonatal septicaemia in Nigeria . Continuous surveillance in every unit, as well as close attention to preventive strategies would be necessary to reduce morbidity and mortality from neonatal septicaemia . We recommend the inclusion of gentamicin in the initial treatment of septicaemia in the neonatal unit of OAUTHC, Ile-Ife, Nigeria. Pediatr Pulmonol, 2002 Apr, 33(4), 311 - 4 Hypersensitivity to inhaled TOBI following reaction to gentamicin; Spigarelli MG et al.; Cystic fibrosis (CF) is the most common autosomal-recessive disease in Caucasians . Colonization with Pseudomonas aeruginosa (P . aeruginosa) of the CF airways causes deterioration of pulmonary status . TOBI (Tobramycin solution for inhalation) is an inhaled antibiotic that can improve the pulmonary disease . We report on a 9-year old boy with CF who developed a rash following a course of IV gentamicin . The rash resolved after its discontinuation . However, the rash returned all over his body, with the start of inhalation of TOBI therapy . We desensitized the patient using escalating doses of inhaled TOBI . He tolerated the procedure well, and continues to be on TOBI 9 months after desensitization on a once-a-day regimen . Pediatr Pulmonol, 2002 Apr, 33(4), 269 - 76 Effects of tobramycin solution for inhalation on global ratings of quality of life in patients with cystic fibrosis and Pseudomonas aeruginosa infection; Quittner AL et al.; In a previously published placebo-controlled trial, tobramycin solution for inhalation (TSI) was shown to improve lung function and other outcomes in patients with cystic fibrosis (CF) . The objectives of the current study were to examine the effects of TSI on global ratings of health-related quality of life (HRQOL) by patients (or their parents) and physicians blind to group assignment, and to determine whether any perceived benefits persisted over time . The global ratings of HRQOL in 520 patients with CF and chronic Pseudomonas aeruginosa infection were analyzed retrospectively . Patients were randomly assigned to receive 24 weeks of placebo or treatment with TSI 300 mg b.i.d., both administered in cycles of 28 days on drug (or placebo) followed by 28 days off, for a total of three cycles . After each on-drug cycle, patients or parents, and physicians, were asked to rate whether the patient's condition was better, unchanged, or worse . There was strong agreement between the paired patient/parent and physician global HRQOL ratings across the three cycles . Regression analyses demonstrated that patients in the TSI group were significantly more likely to report improvements in HRQOL than were patients in the placebo group . This effect was found to be both immediate (end of on-drug cycle 1) and delayed (end of subsequent on-drug cycles 2 and 3) (P < 0.05) . In addition, change in forced expired volume in 1 sec (FEV(1)) % predicted values was a significant predictor of improvement in HRQOL ratings by patients and parents . After controlling for change in FEV(1) % predicted, physician ratings showed significant improvement only at the end of cycle 1 . Finally, controlling for initial lung disease severity, longitudinal growth models revealed that patients on TSI and their physicians reported higher HRQOL ratings than did placebo patients and their physicians across the three cycles; however, the magnitude of this effect decreased over time . Results of this study provided consistent evidence that TSI was associated with improved global ratings of HRQOL completed by both patients or parents, and physicians . Although these results are promising, they are limited by the use of a single-item rating of health . Future studies of the effects of TSI should utilize a well-validated, disease-specific measure of HRQOL . Mol Genet Genomics, 2002 Mar, 267(1), 38 - 44 Epub 2002 Feb 19. Organization and activation of the late promoters of phiCTX, a cytotoxin-converting phage from Pseudomonas aeruginosa; Alber J et al.; The late genes of the temperate phage of Pseudomonas aeruginosa are organized in an analogous fashion to the corresponding transcription units of the Escherichia coli P2 and P2-like phages . Sequence analysis of four putative late promoter regions, PP(phiCTX), PO(phiCTX), PV(phiCTX) and PF(phiCTX), reveals no similarity to sigma(70)-type promoters or promoter consensus sequences found in Pseudomonas, indicating the apparent need for a phage-encoded protein to control the expression of phiCTX late genes . To elucidate the mode of expression of the late genes, we fused the putative late promoter regions to the promoterless lacZalpha gene, which encodes the N-terminal part of beta-galactosidase as a reporter enzyme, in the promoter-probe vector pME4510 . The candidate transactivator gene orf34 was cloned into expression vector pHA10, to generate the plasmid pHA34 . The two recombinant plasmids were introduced together into E . coli XL1-Blue and P . aeruginosa PAO1S-Lac . Our results demonstrate that in phiCTX three late promoters (PP(phiCTX), PO(phiCTX), and PF(phiCTX)) are activated upon induction by IPTG in PAO1S-Lac carrying the cloned promoters and pHA34 . Deletions and base-pair substitutions obtained by PCR-mediated mutagenesis demonstrated that two conserved sequences, TTGTAG-N(9)-cTACAa and GcCGCGCGCGCGgC, are essential for effective late gene expression . Whereas the late promoters were active in P . aeruginosa, only weak beta-galactosidase activity was obtained in E . coli. Clin Infect Dis, 2002 Apr 15, 34(8), 1047 - 54 Epub 2002 Mar 15. Pseudomonas aeruginosa ventilator-associated pneumonia: comparison of episodes due to piperacillin-resistant versus piperacillin-susceptible organisms; Trouillet JL et al.; We sought to determine the epidemiological characteristics of patients in an intensive care unit (ICU) who developed ventilator-associated pneumonia (VAP) caused by piperacillin-resistant Pseudomonas aeruginosa (PRPA; n=34) or piperacillin-susceptible P . aeruginosa (PSPA; n=101) . According to univariate analysis, the factors associated with the development of PRPA VAP were presence of an underlying fatal medical condition, immunocompromised status, longer previous hospital stay, less-severe illness at the time of ICU admission, duration of mechanical ventilation before onset of VAP, number of classes of antibiotic received, and previous exposure to imipenem or fluoroquinolone . Multivariate logistic regression analysis identified the following significant independent factors: presence of an underlying fatal medical condition (odds ratio {OR}, 5.6), previous fluoroquinolone use (OR, 4.6), and initial disease severity (OR, 0.8) . We concluded that the clinical characteristics of patients who develop PRPA VAP differ from those of patients who develop PSPA VAP . Restricted fluoroquinolone use is the sole independent risk factor for PRPA VAP that is open to medical intervention. Nat Immunol, 2002 Apr, 3(4), 354 - 9 Epub 2002 Mar 25. Human Toll-like receptor 4 recognizes host-specific LPS modifications; Hajjar AM et al.; Lipopolysaccharide (LPS) is the principal proinflammatory component of the Gram-negative bacterial envelope and is recognized by the Toll-like receptor 4 (TLR4)-MD-2 receptor complex . Bacteria can alter the acylation state of their LPS in response to environmental changes . One opportunistic bacterium, Pseudomonas aeruginosa, synthesizes more highly acylated (hexa-acylated) LPS structures during adaptation to the cystic fibrosis airway . Here we show that human, but not murine, TLR4-MD-2 recognizes this adaptation and transmits robust proinflammatory signals in response to hexa-acylated but not penta-acylated LPS from P . aeruginosa . Whereas responses to lipidIVA and taxol are dependent on murine MD-2, discrimination of P . aeruginosa LPS structures is mediated by an 82-amino-acid region of human TLR4 that is hypervariable across species . Thus, in contrast to mice, humans use TLR4 to recognize a molecular signature of bacterial-host adaptation to modulate the innate immune response. Int J Biol Macromol, 2002 Apr 8, 30(2), 105 - 11 Monomer composition and sequence of alginates from Pseudomonas aeruginosa; Schurks N et al.; Alginates from four strains of Pseudomonas aeruginosa, one mucoid strain isolated from a technical water system, one strain isolated from a patient with cystic fibrosis and two mutants of this strain with a defect which affects the O-acetylation of the extracellular alginate, have been isolated and analysed for monomer composition and sequence by 13C-nuclear magnetic resonance (NMR) spectroscopy . The detected contributions of different monomer triplets (triads) were compared with values expected from a statistical chain constitution based on the given monomer ratio . While a typical algal alginate presents a nearly statistical distribution of uronic acids in the polymer chain, a strong deviation from the statistical arrangement of mannuronate (M) and guluronate (G) was found in the alginate of the mucoid strains of P . aeruginosa, being most expressed for the triad MMM . This feature is partially lost in the alginate from the mutant strains, indicating that the O-acetylation is linked to a mechanism which takes influence on the chain sequence . The strong preference for MG-pairs in the parent strain of P . aeruginosa may be connected to a stronger binding of cations in the MG-vicinity. Int J Biol Macromol, 2002 Apr 8, 30(2), 67 - 74 Rheological characteristics of microbial suspensions of Pseudomonas aeruginosa and Bacillus cereus; Al-Asheh S et al.; The rheological properties of the bacteria Pseudomonas aeruginosa and Bacillus cereus have been investigated . The apparent viscosity of the bacterial suspensions has been measured at different conditions . The results showed that the bacterial suspensions' apparent viscosity increased with increasing biomass concentration of each of these strains . The P . aeruginosa suspension followed shear thinning behavior while B . cereus suspension followed shear thickening behavior . The shear stress versus shear rate experimental data were best represented by the Herschel-Bulkley model . The apparent viscosity of the P . aeruginosa and B . cereus suspensions decreased with increasing temperature . The relationship between the apparent viscosity and the shearing time highlighted the rheopectic behavior of the suspensions used in this work. J Biol Chem, 2002 May 31, 277(22), 19792 - 9 Epub 2002 Mar 21. Species-specific inhibition of porphobilinogen synthase by 4-oxosebacic acid; Jaffe EK et al.; Porphobilinogen synthase (PBGS) catalyzes the condensation of two molecules of 5-aminolevulinic acid (ALA), an essential step in tetrapyrrole biosynthesis . 4-Oxosebacic acid (4-OSA) and 4,7-dioxosebacic acid (4,7-DOSA) are bisubstrate reaction intermediate analogs for PBGS . We show that 4-OSA is an active site-directed irreversible inhibitor for Escherichia coli PBGS, whereas human, pea, Pseudomonas aeruginosa, and Bradyrhizobium japonicum PBGS are insensitive to inhibition by 4-OSA . Some variants of human PBGS (engineered to resemble E . coli PBGS) have increased sensitivity to inactivation by 4-OSA, suggesting a structural basis for the specificity . The specificity of 4-OSA as a PBGS inhibitor is significantly narrower than that of 4,7-DOSA . Comparison of the crystal structures for E . coli PBGS inactivated by 4-OSA versus 4,7-DOSA shows significant variation in the half of the inhibitor that mimics the second substrate molecule (A-side ALA) . Compensatory changes occur in the structure of the active site lid, which suggests that similar changes normally occur to accommodate numerous hybridization changes that must occur at C3 of A-side ALA during the PBGS-catalyzed reaction . A comparison of these with other PBGS structures identifies highly conserved active site water molecules, which are isolated from bulk solvent and implicated as proton acceptors in the PBGS-catalyzed reaction. J Antimicrob Chemother, 2002 Apr, 49(4), 631 - 9 Pseudomonas aeruginosa cells adapted to benzalkonium chloride show resistance to other membrane-active agents but not to clinically relevant antibiotics; Loughlin MF et al.; Our objective was to determine whether strains of Pseudomonas aeruginosa can adapt to growth in increasing concentrations of the disinfectant benzalkonium chloride (BKC), and whether co-resistance to clinically relevant antimicrobial agents occurs . Attempts were made to determine what phenotypic alterations accompanied resistance and whether these explained the mechanism of resistance . Strains were serially passaged in increasing concentrations of BKC in static nutrient broth cultures . Serotyping and genotyping were used to determine purity of the cultures . Two strains were examined for cross-resistance to other disinfectants and antibiotics by broth dilution MIC determination . Alterations in outer membrane proteins and lipopolysaccharide (LPS) expressed were examined by SDS-PAGE . Cell surface hydrophobicity and charge, uptake of disinfectant and proportion of specific fatty acid content of outer and cytoplasmic membranes were determined . Two P . aeruginosa strains showed a stable increase in resistance to BKC . Co-resistance to other quaternary ammonium compounds was observed in both strains; chloramphenicol and polymyxin B resistance were observed in one and a reduction in resistance to tobramycin observed in the other . However, no increased resistance to other biocides (chlorhexidine, triclosan, thymol) or antibiotics (ceftazidime, imipenem, ciprofloxacin, tobramycin) was detected . Characteristics accompanying resistance included alterations in outer membrane proteins, uptake of BKC, cell surface charge and hydrophobicity, and fatty acid content of the cytoplasmic membrane, although no evidence was found for alterations in LPS . Each of the two strains had different alterations in phenotype, indicating that such adaptation is unique to each strain of P . aeruginosa and does not result from a single mechanism shared by the whole species. Biochem Biophys Res Commun, 2002 Mar 29, 292(2), 513 - 8 Secondary-site mutation restores the transport defect caused by the transmembrane domain mutation of the xenobiotic transporter MexB in Pseudomonas aeruginosa; Yoneyama H et al.; It has been suggested that the MexB subunit of the MexAB-OprM efflux transporter of Pseudomonas aeruginosa exports xenobiotics in an energy-dependent manner . To investigate the role of the transmembrane segments (TMS) of MexB in the transporter activity, we isolated 24 spontaneous mutants showing hypersusceptibility to antibiotics . Among them, three mutations were located at TMS-3, TMS-4, and TMS-10 having amino acid substitution Leu376vPro, Gly397vVal, and Val928vGly, respectively . A secondary mutation, which suppressed the defect caused by the Val928vGly mutation in TMS-10, was found at the 403rd amino acid residue in TMS-4 with a change of glycine to serine, suggesting that TMS-4 and TMS-10 may be in close proximity . This result provided strong support for the recent notion that negatively charged residues in TMS-4 might form a salt-bridge with a positive charge in TMS-10 (Guan, L., and Nakae, T . (2001) J . Bacteriol . 183, 1734-1739) . The transporter function impaired by the Gly397vVal mutation in TMS-4 was recovered by the secondary mutation, Gln998vHis, in the loop between TMS-11 and TMS-12, thereby suggesting that TMS-4 and TMS-11 or TMS-12 might also be in close proximity . Thus, it is most likely that TMS-4, TMS-10, and TMS-11 or TMS-12 are packed close three dimensionally . (c)2002 Elsevier Science (USA). Chemotherapy, 2002 Mar, 48(1), 31 - 5 Investigation of various antibiotic combinations using the E-Test method in multiresistant Pseudomonas aeruginosa strains; Kocazeybek B et al.; BACKGROUND: Antibiotic combinations are frequently used in order to obtain wide-spectrum effects in the treatment of serious infections such as septicemia and endocarditis, and also to produce an in vivo effect against strains which are defined as resistant to the known inhibiting or fatal dose of one antibiotic . The synergistic effects of combinations such as aminoglycoside + beta-lactam, aminoglycoside + quinolone and quinolone + beta-lactam on Pseudomonas aeruginosa have been revealed in different studies . The multiple resistance rate of nosocomial P . aeruginosa strains isolated from intensive care units (ICUs) has been reported as high in many studies . METHODS: In this study, the effects of various combinations of antibiotics (aminoglycoside + beta-lactam and aminoglycoside + quinolone) against 101 multiresistant P . aeruginosa strains which were isolated from the ICUs of three different hospitals in Istanbul were investigated using the E-test method . The combinations for which the highest synergistic effects were determined by the E-test method were also tested with the checkerboard method, i.e . in addition to the E-test method, in 19 of a total of 23 strains . RESULTS: When the synergistic results which were obtained with the combinations of aminoglycoside + beta-lactam were compared with those of the aminoglycoside + quinolone combinations, they were determined to be higher for the two aminoglycosides gentamicin (GM) and tobramycin (TM) . We determined the synergistic rates to be 23, 21, 19, 18, 16, 14, 10 and 10% for GM + ceftriaxone (TX), GM + piperacillin (PP), GM + ceftazidime (TZ), TM + PP, TM + TX, TM + TZ, GM + ciprofloxacin (CI) and TM + CI, respectively . The GM + TX combination - for which the highest synergistic effects were determined with the E-test stripes - was also determined as synergistic with the checkerboard method in 19 of a total of 23 strains (23%), and the agreement rate between the two methods was 100% (kappa > 0.7) . The highest synergistic effects against strains which were sensitive to both of the antibiotics which constitute the combinations were found for the GM + TX combination, as 50%, whereas for strains which were resistant to both of the antibiotics, this was found for the TM + PP combination, also as 50% . CONCLUSIONS: We consider that the minimal inhibitory concentration values of antibiotics are not sufficient alone in order to constitute a combination for multiresistant strains and it would be advisable to begin a treatment by applying a combination study . The E-test method has been evaluated as a good alternative for combination investigations because of its ease both of application and evaluation and also for its good agreement with the standard checkerboard method . Infect Immun, 2002 Apr, 70(4), 2230 - 2 Membrane localization contributes to the in vivo ADP-ribosylation of Ras by Pseudomonas aeruginosa ExoS; Riese MJ et al.; Type III-delivered exoenzyme S (ExoS) preferentially ADP-ribosylated membrane-associated His(6)HRas, relative to its cytosolic derivative His(6)HRas Delta CAAX . This indicates that the subcellular protein distribution contributes to in vivo ADP-ribosylation by ExoS. Infect Immun, 2002 Apr, 70(4), 2198 - 205 Pseudomonas aeruginosa ExoT acts in vivo as a GTPase-activating protein for RhoA, Rac1, and Cdc42; Kazmierczak BI et al.; The Pseudomonas aeruginosa protein ExoT is a bacterial GTPase-activating protein (GAP) that has in vitro activity toward Rho, Rac, and Cdc42 GTPases . Expression of ExoT both inhibits the internalization of strain PA103 by macrophages and epithelial cells and is associated with morphological changes (cell rounding and detachment) of infected cells . We find that expression of ExoT leads to the loss of GTP-bound RhoA, Rac1, and Cdc42 in transfected HeLa cells, demonstrating that ExoT has GAP activity in vivo toward all three GTPases . GAP activity is absolutely dependent on the presence of arginine at position 149 but is not affected by whether ExoT is expressed in the absence or presence of other P . aeruginosa type III secreted proteins . We also demonstrate that expression of ExoT in epithelial cells is sufficient to cause stress fiber disassembly by means of ExoT's GAP activity toward RhoA. Infect Immun, 2002 Apr, 70(4), 2187 - 97 Balance of pro- and anti-inflammatory cytokines correlates with outcome of acute experimental Pseudomonas aeruginosa keratitis; Thakur A et al.; The purpose of this study was to elucidate the expression of pro- and anti-inflammatory cytokines in mouse corneas infected with Pseudomonas aeruginosa . Three bacterial strains (invasive, cytotoxic, or CLARE {contact lens-induced acute red eye}) which have recently been shown to produce distinct patterns of corneal disease in the mouse were used . The left mouse (BALB/c) corneas were scarified and infected with 2 x 10(6) CFU of one of the three P . aeruginosa strains, while right eyes served as controls . Animals were examined at 1, 4, 8, 16, and 24 h with a slit lamp biomicroscope to grade the severity of infection . Following examination, eyes were collected and processed for histopathology, multiprobe RNase protection assay for cytokine mRNA, enzyme-linked immunosorbent assay to quantitate cytokine proteins, and myeloperoxidase activity to quantitate polymorphonuclear leukocytes . The kinetics of appearance and magnitude of expression of key cytokines varied significantly in the three different phenotypes of P . aeruginosa infection . The predominant cytokines expressed in response to all three phenotypes were interleukin-1 beta (IL-1 beta), IL-1Ra, and IL-6 . In response to the invasive strain, which induced severe corneal inflammation, significantly lower ratios of IL-1Ra to IL-1 beta were present at all time points, whereas corneas challenged with the CLARE strain, which induced very mild inflammation, showed a high ratio of IL-1Ra to IL-1 beta . The outcome of infection in bacterial keratitis correlated with the relative induction of these pro- and anti-inflammatory cytokines, and exogenous administration of recombinant rIL-1Ra (rIL-1Ra) was able to reduce the disease severity significantly . These findings point to the therapeutic potential of rIL-1Ra protein in possible treatment strategies for bacterial keratitis. Infect Immun, 2002 Apr, 70(4), 1783 - 90 Pseudomonas aeruginosa quorum-sensing systems may control virulence factor expression in the lungs of patients with cystic fibrosis; Erickson DL et al.; Individuals with cystic fibrosis (CF) are commonly colonized with Pseudomonas aeruginosa . The chronic infections caused by P . aeruginosa are punctuated by acute exacerbations of the lung disease, which lead to significant morbidity and mortality . As regulators of virulence determinants, P . aeruginosa quorum-sensing systems may be active in the chronic lung infections associated with CF . We have examined the levels of autoinducer molecules and transcript accumulation from the bacterial populations found in the lungs of patients with CF . We detected biologically active levels of N-(3-oxododecanoyl)-L-homoserine (3-oxo-C12-HSL) and N-butyryl-L-homoserine lactone (C4-HSL) in sputum from CF patients . Interestingly, it appears that C4-HSL is less frequently detected than 3-oxo-C12-HSL in the lungs of patients with CF . We also examined the transcription of the autoinducer synthase gene lasI and showed that it is frequently expressed in the lungs of patients with CF . We observed a significant correlation between the expression of lasI and four target genes of the Las quorum-sensing system . Taken together, our results indicate that quorum-sensing systems are active and may control virulence factor expression in the lungs of patients with CF. Blood, 2002 Apr 1, 99(7), 2483 - 9 Ex vivo development of functional human lymph node and bronchus-associated lymphoid tissue; Tirouvanziam R et al.; We introduce a novel in vivo model of human mucosal immunity, based on the implantation of human fetal bronchial mucosa and autologous peribronchial lymph node (PLN) in the severe combined immunodeficiency (SCID) mouse . In the SCID host, human fetal bronchi implanted alone retain macrophages and mast cells but lose T cells . In contrast, fetal bronchi co-implanted with PLN contain, in addition to macrophages and mast cells, numerous T cells and B cells, often clustered in intramucosal bronchus-associated lymphoid tissue (BALT) . Functionally, bronchus-PLN cografts are able to mount robust alphabeta and gammadelta T-cell-mediated immune responses to Pseudomonas aeruginosa and 3,4-epoxy-3-methyl-1-butyl-diphosphate challenges . No other autologous lymphoid organ (bone marrow, thymus, liver) allows for BALT development in co-implanted bronchi, which suggests special ontogenetic and functional relations between extramucosal PLN and intramucosal BALT . Overall, the bronchus-PLN cograft appears as a promising model for human bronchial immune development and function . Our study is the first to document long-term ex vivo maintenance of functional human lymph nodes as native appendices to mucosal tissue . Our results, therefore, suggest a simple strategy for developing similar experimental models of human immune function in other mucosae. Curr Top Med Chem, 2001 May, 1(1), 73 - 82 Siderophore-antibiotic conjugates used as trojan horses against Pseudomonas aeruginosa; Budzikiewicz H; Pseudomonas aeruginosa is a dangerous opportunistic bacterium responsible for frequently lethal hospital (nosocomial) infections . It endangers especially severely injured patients suffering from large wounds or severe burns, as well as persons whose immune system is weakened . An extremely critical situation exists for patients suffering from mucoviscidosis (cystic fibrosis), when P . aeruginosa infects the bronchial tubes . P . aeruginosa is resistant against many disinfecting agents and, more important, an increasing number of strains especially from hospital isolates have become highly resistant against most antibiotics . The low permeability of the outer membrane and an active export mechanism for low molecular weight substances are the main reasons for the resistance . In addition, beta-lactamase activity affects treatment with beta-lactam antibiotics . An approach to overcome the problem of resistance lies in the synthesis of antibiotics conjugated with compounds active as siderophores . In this way the transport ways for iron complexes into the cell can be used ("Trojan Horse strategy"), and the presence of large substituents reduces the export and the beta-lactamase activity . The results obtained with natural (pyoverdins) and synthetic (mainly catecholate) siderophores will be reviewed. Curr Top Med Chem, 2001 May, 1(1), 59 - 71 Multidrug efflux in Pseudomonas aeruginosa: components, mechanisms and clinical significance; Poole K et al.; Pseudomonas aeruginosa is an opportunistic human pathogen characterized by an intrinsic resistance to multiple antimicrobial agents and the ability to develop high-level (acquired) multidrug resistance during antibiotic therapy . Much of this resistance is promoted by highly homologous three-component efflux systems of broad substrate specificity, of which four have been identified to date . These include MexA-Mexs-OprM and MexX-MexY-OprM, which are expressed constitutively in wild type cells and, thus, provide for intrinsic multidrug resistance, and MexC-MexD-OprJ and MexE-MexF-OprN, whose expression so far has only been seen in acquired multidrug resistant mutant strains . Additional homologues of these efflux systems are identifiable in the recently released genome sequence, though their roles, if any, in antimicrobial efflux are unknown . These tripartite pumps are composed of an integral cytoplasmic membrane drug-proton antiporter of the resistance-nodulation-cell division (RND) family of exporters, a channel-forming outer membrane efflux protein (or outer membrane factor {OMF}) and a periplasmic membrane fusion protein (MFP) that links the other two . In addition to a number of antimicrobials of clinical significance, these pumps also export dyes, detergents, disinfectants, organic solvents and acylated homoserine lactones involved in quorum-sensing . While the natural functional of these pumps remains undefined, the fact that they contribute to antimicrobial resistance in P . aeruginosa makes them reasonable targets for therapeutic intervention. Curr Top Med Chem, 2001 May, 1(1), 1 - 6 Siderophores of the human pathogenic fluorescent pseudomonads; Budzikiewicz H; Bacteria need a sufficient supply of iron in ionic form for their metabolism . When living in an environment where this is not possible (as in the soil due to the presence of highly unsoluble ferric oxide hydrates, or in living organisms where iron is bound to peptidic chelators) Fe3+ complexing compounds, called siderophores, are produced . The siderophores of Pseudomonas aeruginosa, a dangerous opportunistic human pathogen, and of related potentially pathogenic species will be presented. Allergy Asthma Proc, 2002 Jan-Feb, 23(1), 19 - 25 Inflammatory mediators in cystic fibrosis lung disease; Berger M; Cystic fibrosis (CF) is a complex multisystem disorder caused by mutations in a membrane glycoprotein called the CF transmembrane regulator (CFTR), which has as its major function serving as a Cl- channel . The relationship between defects in CFTR and development of lung disease remains incompletely understood . Chronic lung disease, characterized by persistent infection with a peculiar type of Pseudomonas aeruginosa, bronchiectasis, and airway obstruction is the major cause of morbidity and mortality in CF patients . The inflammatory response to the chronic infection resembles that induced by lipopolysaccharide (LPS) and is mediated primarily by cytokines such as tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-6, and IL-8, whose synthesis is activated by the transcription factor nuclear factor kappa B (NF-kappa B) . Large numbers of neutrophils dominate the inflammatory response and excessive concentrations of their products create a vicious cycle that becomes injurious rather than protective and eventually claims the life of the patient. Eur J Med Res, 2002 Feb 21, 7(2), 79 - 80 Eradication of initial Pseudomonas aeruginosa colonization in patients with cystic fibrosis; Griese M et al.; The optimal treatment for the eradication of initial P . aeruginosa infection in CF is still unclear . Recently long-term inhaled tobramycin has been proposed . Here we report the results with brief inhaled and/or systemic anti-pseudomonal treatments . Initial P . aeruginosa colonization was successfully eradicated as demonstrated by negative repetitive throat cultures or sputa and serum antipseudomonal antibodies in 15 of 17 patients for at least two years . Randomized, controlled trials are urgently needed to define the optimal protocol for the eradication of P . aeruginosa . Pseudomonas aeruginosa, infection, treatment, antibodies; inhaled tobramycin Crit Care Med, 2002 Feb, 30(2), 442 - 7 Beneficial effects of nitric oxide inhalation on pulmonary bacterial clearance; Jean D et al.; OBJECTIVE: The beneficial effects of nitric oxide inhalation on oxygenation during acute respiratory distress syndrome are well described . In contrast, the effects of nitric oxide on pulmonary inflammatory response are much less known in vivo . The objectives of this study were to evaluate the effects of nitric oxide inhalation on bacterial clearance during bacterial pneumonia and on alveolar neutrophil functions . DESIGN: Controlled animal study . SETTING: Research laboratory of an academic institution . SUBJECTS: Male Sprague-Dawley rats . INTERVENTIONS: Severe pneumonia was induced by alveolar instillation of live Pseudomonas aeruginosa (1.5 x 10(8) colony-forming units/kg) in rats . After instillation, rats were exposed to oxygen alone (FIO(2) 100%) or to oxygen (FIO(2) approximately 100%) plus nitric oxide (10 ppm) during 24 hrs . MEASUREMENTS AND MAIN RESULTS: Oxygen plus nitric oxide inhalation compared with oxygen alone increased recruitment of alveolar neutrophils (32.5 +/- 4.6 x 10(6) cells/mL vs . 23.4 +/- 1.9 x 10(6) cells/mL, p <.05) and improved bacterial clearance in the bronchoalveolar lavage fluid (8.1 +/- 4.2 x 10(2) vs . 1.6 +/- 1.0 x 10(5) colony-forming units/mL, p <.05) and in the pulmonary parenchyma (1.7 +/- 1.14 x 10(7) vs . 3.4 +/- 1.5 x 10(8) colony-forming units/mL, p <.05) . However, neither protein concentration in the bronchoalveolar lavage fluid nor mortality rates were modified by nitric oxide inhalation . The ex vivo alveolar neutrophil functions were similar regardless of whether rats previously inhaled nitric oxide . In vitro experiments demonstrated that nitric oxide donor had a direct bactericidal effect against P . aeruginosa and did not modify alveolar neutrophil functions . CONCLUSIONS: These results suggest a beneficial effect of nitric oxide inhalation on bacterial clearance of P . aeruginosa attributable to both a direct bactericidal effect and an influx of alveolar neutrophils with preserved functions. Crit Care Med, 2002 Feb, 30(2), 315 - 22 Impairment of polymorphonuclear neutrophil functions precedes nosocomial infections in critically ill patients; Stephan F et al.; OBJECTIVE: A postinjury immunodepression involving neutrophil functions has been described in critically ill patients . The aim of this prospective study was to search for a relationship between an impairment of neutrophil functions and the subsequent development of nosocomial infection . DESIGN: Twenty-one severely ill (simplified acute physiology score II >20 on admission), nonimmunosuppressed patients who were receiving no antibiotics active against methicillin-resistant Staphylococcus aureus and highly resistant Pseudomonas aeruginosa were included . Twelve healthy subjects constituted a control group . MEASUREMENTS: Neutrophil functions (phagocytosis and bactericidal activity toward S . aureus and P . aeruginosa in homologous plasma, reactive oxygen species secretion) were studied at day 4 +/- 1 after admission, and occurrence of nosocomial infection was prospectively recorded over the following 5 days . Interleukin-10 concentration was assessed by enzyme-linked immunosorbent assay . Results are expressed as median (25th-75th percentiles) . MAIN RESULTS: Six out of the 21 patients acquired a nosocomial infection during the 5 days after blood sampling (infected group) . Compared with the patients who did not acquire nosocomial infection (noninfected group, n = 15), the neutrophils of the infected group demonstrated a higher percentage of intracellular bacterial survival (17% {2% to 67%} vs . infected: 62% {22% to 100%}, p <.05), leading to an impairment of S . aureus killing in homologous plasma (killed bacteria: 4.93 log(10) colony forming units/mL {4.24-5.29} vs . infected: 3.62 log(10) colony forming units/mL {0.00-4.58}, p <.05) . Interleukin-10 plasma concentration was higher in infected patients (78 pg/mL {60-83}) compared with noninfected patients (22 pg/mL {14-58}, p <.05) . By contrast, P . aeruginosa killing was similar in patients whether or not they acquired a nosocomial infection . CONCLUSION: A decrease in S . aureus killing capabilities of neutrophils can be evidenced within the days before occurrence of a nosocomial infection. J Bacteriol, 2002 Apr, 184(7), 2045 - 9 Differential effects of mutations in tonB1 on intrinsic multidrug resistance and iron acquisition in Pseudomonas aeruginosa; Zhao Q et al.; Loss of tonB1 adversely affects iron acquisition and intrinsic multidrug resistance in Pseudomonas aeruginosa . Several mutations in tonB1 compromised the protein's contribution to both processes, although TonB1 derivatives altered in residues C35, Q268, R287, Q292, R300, and R304 were compromised vis-a-vis their contribution to drug resistance only. Chest, 2002 Mar, 121(3), 863 - 70 Silver-coated endotracheal tubes associated with reduced bacterial burden in the lungs of mechanically ventilated dogs; Olson ME et al.; STUDY OBJECTIVES: To evaluate the influence of silver-coated endotracheal tubes on the lung bacterial burden of mechanically ventilated dogs . DESIGN: Randomized, double-blinded, controlled experiment . SETTING: Animal research facility of a regional medical university . PATIENTS OR PARTICIPANTS: Eleven healthy adult dogs . INTERVENTIONS: The dogs were intubated either with cuffed, noncoated endotracheal tubes or with endotracheal tubes having a novel antimicrobial silver hydrogel coating and were challenged with buccal administration of Pseudomonas aeruginosa . MEASUREMENTS AND RESULTS: The silver coating delayed the appearance of bacteria on the inner surface of the endotracheal tubes ({mean +/- SD} duration of mechanical ventilation before appearance of bacteria, 3.2 +/- 0.8 days; mean duration of mechanical ventilation, 1.8 +/- 0.4 days; p = 0.016) . The mean total aerobic bacterial burden in the lung parenchyma was statistically lower among the dogs receiving the silver-coated endotracheal tubes compared to those not receiving them (4.8 +/- 0.8 vs 5.4 +/- 9 log cfu/g lung tissue, respectively; p = 0.010) . Pronounced differences were seen in the gross and histologic assessments of inflammation in the lung . Using an increasing severity scale of 0 to 12 to assess four components of histology (ie, hyperemia, edema, cellular infiltration, and bacterial presence), dogs receiving noncoated endotracheal tubes had statistically greater histology scores compared to dogs receiving silver-coated endotracheal tubes (7.1 plus minus 1.6 vs 2.8 plus minus 1.2, respectively; p < 0.001) . CONCLUSION: These results suggest that the silver coating of endotracheal tubes may delay the onset of and decrease the severity of lung colonization by aerobic bacteria . Based on these results, clinical studies are planned to determine the safety and clinical efficacy of silver-coated endotracheal tubes in patients requiring mechanical ventilation in the ICU setting. Med Clin (Barc), 2002 Mar 9, 118(8), 299 - 301 {Life-threatening hemoptysis in cystic fibrosis: clinical characteristics and management in 36 episodes}; Maiz L et al.; BACKGROUND: Our goal was to evaluate the clinical characteristics and management of life-threatening hemoptysis in patients with cystic fibrosis (CF) . PATIENTS AND METHOD: We included adult CF patients followed up at the Cystic Fibrosis Units of the Autonomous Community of Madrid who had life-threatening hemoptysis from June 1990 to December 1999 . RESULTS: Twelve CF patients (4 females) developed 36 episodes of life-threatening hemoptysis (30 massive and 6 recurrent) . Lung disease was moderate to severe . Sputum cultures revealed Pseudomonas aeruginosa in 10 patients . Thirteen episodes (36%) resolved upon antibiotic treatment and 3 (8%) after antibiotic therapy and bronchoscopy . Bronchial artery embolization (BAE) was performed in 20 of 36 events . Immediate technique success was achieved in 80% episodes (16 of 20) after one session, 85% (17/20) after two sessions, and 95% (19/20) after three sessions . No major complications associated with the procedure were seen . The overall recurrence rate per episode was 69% (24 of 35 episodes in 6 patients) with a mean time of recurrence of 13 months . There were no massive hemoptysis-associated deaths during the follow-up . CONCLUSIONS: Life-threatening hemoptysis is a frequent complication in CF patients who have moderate or severe lung disease . When conservative therapeutic measures (including antibiotics) fail to control it, BAE should be performed . When performed by expert professionals, BAE is effective and safe to immediate control of life-threatening hemoptysis in patients with CF. Rev Mal Respir, 2001 Oct, 18(5), 549 - 51 {Allergic bronchopulmonary aspergillosis disclosing mucoviscidosis}; Coltey B et al.; In predisposed patients, allergic bronchopulmonary aspergillosis (ABPA) can arise from aspergillus bronchial colonization . We report the case of a young woman who presented with a right basal pneumonia, ground glass opacities and mediastinal adenopathies on CT scan . Biological, radiological and clinical criteria, as well as an history of childhood asthma, allowed the initial diagnosis of ABPA . However, the unusual coexistence of an additional infection with Pseudomonas Aeruginosa evoked the diagnosis of cystic fibrosis, confirmed by a sweat test and genetic analysis . Under corticosteroid and antifungal therapy and antibiotics, the clinical and radiological evolution was favourable but immuno-allergic sensitisation persisted . The ABPA-cystic fibrosis association is not rare with an estimated prevalence of 2% to 11% according to previous studies . This variability is partly explained by the difficulty of the diagnosis due to confounding clinical, radiological, and biological signs between ABPA and cystic fibrosis . Many predictive development factors of ABPA in the context of cystic fibrosis have been reported, including respiratory function, personal or familial atopy, colonization with Pseudomonas Aeruginosa and age . As in non cystic fibrosis patients, the treatment requires systemic corticotherapy and itraconazole . ABPA is still often under diagnosed and should be evoked in the context of cystic fibrosis. Recenti Prog Med, 2002 Feb, 93(2), 104 - 7 {External otitis}; Olina M et al.; Otitis externa is one of the most common diseases in ORL practice, during summer; the t