Pediatrics . 2000 Dec;106(6):E89. Technical report: precautions regarding the use of aerosolized antibiotics . Committee on Infectious Diseases and Committee on Drugs; Prober CG et al.; In 1998, the Food and Drug Administration (FDA) approved the licensure of tobramycin solution for inhalation (TOBI) . Although a number of additional antibiotics, including other aminoglycosides, beta-lactams, antibiotics in the polymyxin class, and vancomycin, have been administered as aerosols for many years, none are approved by the FDA for administration by inhalation . TOBI was approved by the FDA for the maintenance therapy of patients 6 years or older with cystic fibrosis (CF) who have between 25% and 75% of predicted forced expiratory volume in 1 second (FEV(1)), are colonized with Pseudomonas aeruginosa, and are able to comply with the prescribed medical regimen . TOBI was not approved for the therapy of acute pulmonary exacerbations in patients with CF nor was it approved for use in patients without CF . Currently, no other antibiotics are approved for administration by inhalation to patients with or without CF . The purpose of this statement is to briefly summarize the data that supported approval for licensure of TOBI and to provide recommendations for its safe use . The pharmacokinetics of inhaled aminoglycosides and problems associated with aerosolized antibiotic treatment, including environmental contamination, selection of resistant microbes, and airway exposure to excipients in intravenous formulations, will be discussed. J Antimicrob Chemother, 2000 Jan, 45(1), 9 - 13 Chromosomal beta-lactamase is packaged into membrane vesicles and secreted from Pseudomonas aeruginosa; Ciofu O et al.; Membrane vesicles were isolated from one beta-lactam-sensitive and three beta-lactam-resistant Pseudomonas aeruginosa clinical isolates from patients with cystic fibrosis . The presence of the chromosomally encoded beta-lactamase in the membrane vesicles was shown by electron microscopy and enzymatic studies . This is the first report of extracellular secretion of beta-lactamase in P . aeruginosa and it seems that the enzyme is packaged into membrane vesicles. J Pineal Res, 2000 Jan, 28(1), 26 - 33 Ototoxicity caused by aminoglycosides is ameliorated by melatonin without interfering with the antibiotic capacity of the drugs; Lopez-Gonzalez MA et al.; The production of free radicals seems to be involved in the mechanisms of ototoxicity . Aminoglycosides produce ototoxicity, which can be determined through distortion product otoacoustic emissions (OAEs) that measure the activity of the outer hair cells of the organ of Corti . An ototoxic chart was obtained in rats using gentamicin or tobramycin . Together with this treatment, the animals ingested melatonin in the drinking water, or melatonin was injected subcutaneously or intramuscularly . The distortion product OAEs were determined over a prolonged period of time for each of the groups . The effect of melatonin on the antibiotic capacity of the aminoglycosides used was also studied . Antibiograms inoculated with Escherichia coli or Pseudomonas aeruginosa and treated with gentamicin or tobramycin in the presence or absence of melatonin at quantities from pharmacological to physiological doses were performed . The ototoxicity produced by gentamicin and tobramycin was maximal from days 3 to 5 post-treatment, returning to normal values in 2 wk . When melatonin was present, the recovery was at day 5 post-treatment, independently of the means of administration of the pineal product . The antibiograms showed that melatonin had no effect on the antibiotic capacity . It is concluded that the ototoxicity caused by gentamicin and tobramycin is ameliorated by melatonin and that the pineal hormone does not interfere with the antibiotic capacity of these antibiotics. Pediatr Res, 2000 Jan, 47(1), 121 - 6 Pseudomonas aeruginosa from patients with cystic fibrosis affects function of pulmonary surfactant; Lema G et al.; Patients with cystic fibrosis are severely affected by an infection with Pseudomonas aeruginosa, a microbe known to synthesize phospholipase C . This study was designed to determine whether that enzyme would affect the function of pulmonary surfactant phospholipids . Mucoid and nonmucoid strains of P . aeruginosa, freshly obtained from patients with cystic fibrosis, were cultured for 12 h on agar plates . The bacteria were suspended in saline solution and then pelleted by centrifugation . The supernatant was used to dilute the surfactant preparation, calf lung surfactant extract, from 35 to 2 mg/mL . Surfactant function, before and after incubation, was examined with a capillary surfactometer, an instrument specifically developed for an evaluation of the ability of surfactant to maintain patency of a narrow glass tube, simulating a terminal conducting airway . Phospholipid hydrolysis was also evaluated biochemically by determining the total content of phospholipids in surfactant before and after incubation . In five experiments, the lipids were separated with thin-layer chromatography, and the phosphorus content was determined in the diacylphosphatidylcholine band before and after incubation for 6, 24, and 48 h . Capillary openness and phospholipid concentration decreased as enzyme concentration and time of incubation increased (p<0.0001) . Linear regression showed a significant correlation between time of capillary openness and phospholipid concentration (r = 0.957; p<0.0001) . Calf lung surfactant extract hydrolysis was catalyzed by extracts of the bacteria, particularly the nonmucoid, analogous to the catalysis observed with phospholipase C . Surfactant hydrolysis catalyzed by enzymes from P . aeruginosa might severely affect surfactant function provided enzyme concentration is high and time of incubation is long. J Immunol, 2000 Jan 15, 164(2), 1037 - 45 Macrophage inflammatory protein-2 is a mediator of polymorphonuclear neutrophil influx in ocular bacterial infection; Kernacki KA et al.; Polymorphonuclear neutrophils (PMN) in Pseudomonas aeruginosa-infected cornea are required to clear bacteria from affected tissue, yet their persistence may contribute to irreversible tissue destruction . This study examined the role of C-X-C chemokines in PMN infiltration into P . aeruginosa-infected cornea and the contribution of these mediators to disease pathology . After P . aeruginosa challenge, corneal PMN number and macrophage inflammatory protein-2 (MIP-2) and KC levels were compared in mice that are susceptible (cornea perforates) or resistant (cornea heals) to P . aeruginosa infection . While corneal PMN myeloperoxidase activity (indicator of PMN number) was similar in both groups of mice at 1 and 3 days postinfection, by 5-7 days postinfection corneas of susceptible mice contained a significantly greater number of inflammatory cells . Corneal MIP-2, but not KC, levels correlated with persistence of PMN in the cornea of susceptible mice . To test the biological relevance of these data, resistant mice were treated systemically with rMIP-2 . This treatment resulted in increased corneal PMN number and significantly exacerbated corneal disease . Conversely, administration of neutralizing MIP-2 pAb to susceptible mice reduced both PMN infiltration and corneal destruction . Collectively, these findings support an important role for MIP-2 in recruitment of PMN to P . aeruginosa-infected cornea . These data also strongly suggest that a timely down-regulation of the host inflammatory response is critical for resolution of infection. Exp Eye Res, 1999 Dec, 69(6), 595 - 601 Effect of galardin on collagen degradation by Pseudomonas aeruginosa; Hao JL et al.; The authors examined the effect of a synthetic peptidyl hydroxamate inhibitor of matrix metalloproteinase, Galardin, on collagen degradation by Pseudomonas aeruginosa (P . aeruginosa) in the presence or absence of keratocytes . Type I collagen gels, with or without suspended keratocytes, were incubated under medium containing sterile P . aeruginosa culture broth and/or Galardin for 24 hr . Degradation of collagen fibrils during culture was measured by the release of hydroxyproline . The conditioned media were also subjected to gelatin zymography and Western blotting to analyse the activation, by P . aeruginosa factor(s), of matrix metalloproteinases (MMPs) released by keratocytes . The effects of protease inhibitors, aprotinin, leupeptin and pepstatin, on collagen degradation by P . aeruginosa were also examined . P . aeruginosa broth by itself induced collegen gel degradation . When keratocytes were present, P . aeruginosa broth increased the amount of degraded collagen even further . Galardin significantly reduced the amounts of collagen degraded by P . aeruginosa culture broth, whether keratocytes were present or absent in the gel . However, the protease inhibitors had no inhibitory effects on collagen degradation . Gelatin zymography and Western blotting revealed that inactive proMMP-1, -2 and -3, released by keratocytes, were converted to active forms in the presence of P . aeruginosa broth . Galardin decreased the amounts of active MMPs and increased those of inactive proMMPs, suggesting that Galardin inhibited the activation of proMMPs by P . aeruginosa . The present results suggest that Galardin inhibits the keratocyte-mediated collagen degradation by P . aeruginosa culture broth, resulting from preventing the conversion of proMMPs to active MMPs . Am J Respir Crit Care Med, 2000 Jan, 161(1), 271 - 9 Effect of Pseudomonas infection on weight loss, lung mechanics, and cytokines in mice; van Heeckeren AM et al.; Poor growth, Pseudomonas aeruginosa endobronchitis, pulmonary inflammation, and decline of lung function are hallmarks of cystic fibrosis (CF), yet the relationship between these features is poorly understood . Because animal models of chronic bronchopulmonary infection with P . aeruginosa used to study pulmonary inflammation in CF have also been associated with weight loss, we sought to determine whether this weight loss was due to the inflammatory process and/or to changes in lung function . P . aeruginosa-laden agarose beads were instilled into the lungs of mice . Weight loss was greatest 3 d after Pseudomonas infection . Infected mice had a rapid though transient rise in absolute neutrophil counts, mTNF-alpha, mIL-1beta, mIL-6, mip-2, and KC in bronchoalveolar lavage fluid . There was no difference in lung resistance or lung compliance measured by body plethysmography between infected and control mice . Weight loss did correlate with the concentration of proinflammatory cytokine levels 3 d after inoculation of mice with Pseudomonas, and body composition analysis revealed loss of skeletal muscle mass . These results suggest that weight loss in P . aeruginosa-infected mice was associated with the inflammatory process and not with altered pulmonary responsiveness . These findings may provide insights into the cause of cachexia and weight loss seen in patients with CF. J Ethnopharmacol, 1999 Nov 1, 67(2), 225 - 8 Screening of some Nigerian medicinal plants for antibacterial activity; Kudi AC et al.; Crude extracts from eight Nigerian medicinal plants, used traditionally in the treatment of infectious and septic diseases in both humans and animals were screened in vitro for antibacterial activity, using the hole-plate diffusion method . Most of the extracts were active against gram-positive bacteria . Two of the plant, Angeiossus schimperi and Anacardium occidentale, had good antibacterial activity against Escherichia coli and Pseudomonas aeruginosa which are gram-negative bacteria. FEMS Immunol Med Microbiol, 2000 Jan, 27(1), 79 - 85 Conformation-dependent antibody response to Pseudomonas aeruginosa outer membrane proteins induced by immunization in humans; Lee N et al.; Outer membrane proteins (OMPs) of pathogenic bacteria have been used as protective antigens in developing bacterial vaccines . In the present study, we compared the antibody responses to a Pseudomonas aeruginosa OMP vaccine elicited in humans and rabbits by immunization . Immunization with the vaccine induced high titers of serum IgG antibody both in rabbits and humans but reactivities of the induced antibodies with the OMPs were different . The rabbit immune sera recognized most of the OMPs in the vaccine both in immunoblot and immunoprecipitation analyses . In contrast, a great variation in band pattern and intensity was observed among the human immune sera in immunoblot analysis, but not in immunoprecipitation analysis . Denaturation of the OMPs did not affect the binding activity of the rabbit immune sera as determined by ELISA, but substantially reduced those of the human immune sera and anti-OMP IgG purified from a pooled normal human plasma . These data suggest that antibody response to P . aeruginosa OMPs elicited by immunization in humans is mainly directed against discontinuous or conformation-dependent epitopes, which should be taken into account in developing vaccines, especially for OMP-derived synthetic peptides. J Biol Chem, 2000 Jan 7, 275(1), 141 - 6 Rac1 and Cdc42 are required for phagocytosis, but not NF-kappaB-dependent gene expression, in macrophages challenged with Pseudomonas aeruginosa; Lee DJ et al.; Macrophages respond to Gram-negative bacterial pathogens by phagocytosis and pro-inflammatory gene expression . These responses may require GTPases that have been implicated in cytoskeletal alterations and activation of NF-kappaB . To determine the role of Rac1 and Cdc42 in signal transduction events triggered by Pseudomonas aeruginosa, we expressed GTP binding-deficient alleles of Rac1 or Cdc42, or Chim-GAP, a Rac1/Cdc42-specific GTPase-activating protein domain, in a subline of RAW 264.7 cells, and challenged the transfected cells with a laboratory strain of P . aeruginosa, PAO1 . Expression of Rac1 N17, Cdc42 N17, or Chim-GAP led to a marked reduction of phagocytosis . In contrast, nuclear translocation of p65 NF-kappaB was unaffected by expression of the same constructs . Incubation of macrophages with PAO1 led to NF-kappaB-dependent expression of inducible nitric-oxide synthase, COX-2, and tumor necrosis factor-alpha, which was unaffected by inhibition of Rac1 or Cdc42 function . Isogenic strains of PAO1 that lacked surface adhesins were poorly ingested; however, they induced pro-inflammatory gene expression with an efficiency equal to that of PAO1 . These results indicate that the signal transduction events leading to phagocytosis and pro-inflammatory protein expression are distinct . Rac1 and Cdc42 serve as effectors of phagocytosis, but not NF-kappaB-dependent gene expression, in the macrophage response to P . aeruginosa. Bioorg Med Chem Lett, 1999 Dec 20, 9(24), 3447 - 52 Novel synthetic analogs of the Pseudomonas autoinducer; Kline T et al.; Release of virulence factors in Pseudomonas aeruginosa is regulated by two N-acylhomoserine lactones, PAI-1 and PAI-2, that activate the respective transcription factors LasR and RhlR . With the goal of developing novel therapeutic agents, we synthesized constrained analogs of PAI-1 and evaluated them in P . aeruginosa . Two of the novel analogs bound to LasR and showed agonist activity in LasR stimulation of a lasI-lacZ reporter construct. J Drug Target, 1999, 7(1), 33 - 41 Aerosolization of low phase transition temperature liposomal tobramycin as a dry powder in an animal model of chronic pulmonary infection caused by Pseudomonas aeruginosa; Beaulac C et al.; Eradication of mucoid Pseudomonas aeruginosa in an animal model of chronic pulmonary infection has been previously demonstrated following the intratracheal administration of Fluidosomes, a low phase transition temperature (low T(C)) liposomal tobramycin preparation administered in liquid form (Beaulac et al., Antimicrob . Agents Chemother., 40, 665-669, 1996) . In the present work, the same liposomal formulation was administered as a dry powder aerosol to an animal model of chronic pulmonary infection in view of a possible clinical development in cystic fibrosis patients . Chronic infection was established by intratracheal administration of 10(5) cfu of a mucoid variant of P . aeruginosa, PA 508, prepared in agar beads . Sixteen hours after one aerosol treatment, the cfu counts performed on lungs (pair) treated with liposomal tobramycin were of 4.31x10(5) cfu/lungs comparatively to 1.32x10(8) and 3.02x10(8) cfu/lungs respectively in untreated and in lungs treated with free antibiotic . Considering the quantity of liposome-tobramycin that has reached the lungs, the results suggest that aerosolization of low T(C) liposomal tobramycin used as a dry powder preparation could be an effective way of treating chronic pulmonary infection caused by Pseudomonas. Enferm Infecc Microbiol Clin, 1999 Nov, 17(9), 439 - 44 {Factors affecting the clinical course of bacteremia . Prospective study at a university hospital}; Rojo MD et al.; BACKGROUND: The aim of this study was to identify the risk factors mainly influencing the mortality of a series of bacteremic patients . METHODS: A prospective study of the clinically significant bacteremias detected in the Hospital Clinico Universitario in Malaga (Spain) over the period from June 1994 to May 1995 was performed . Univariate analysis of the results was carried out with the chi 2 test and multivariate analysis was undertaken by logistic regression (Stepwise backward) . RESULTS: The incidence of bacteremia was of 19.5 cases/1,000 admissions and the mortality was of 21.9% . According to the univariate analysis, 11 variables were significantly associated with greater risk death: age > 60 years, stay in the intensive care unit, respiratory diseases as the main diagnosis, etiology by Pseudomonas aeruginosa, absence of fever, septic shock, presence of chronic renal insufficiency, cirrhosis or heart disease with underlying diseases, performance of invasive procedures prior to and hospital stay of less than 10 days . Logistic regression analysis determined the factors which mainly influenced in the prognosis of bacteremia: septic shock (p < 0.0001, odds ratio {OR}: 17.97), cardiovascular diseases (p = 0.004, OR: 9.86), AIDS (p = 0.03; OR: 1.02) . CONCLUSIONS: Although the prognosis of bacteremia is strongly influenced by determined conditions of the patient, it may be improved, overall through the control of possible hemodynamic complications of the patients and to a lesser extent by antibiotic treatment. J Bacteriol, 2000 Jan, 182(1), 100 - 6 HbaR, a 4-hydroxybenzoate sensor and FNR-CRP superfamily member, regulates anaerobic 4-hydroxybenzoate degradation by Rhodopseudomonas palustris; Egland PG et al.; Under anaerobic conditions, structurally diverse aromatic compounds are catabolized by bacteria to form benzoyl-coenzyme A (benzoyl-CoA), the starting compound for a central reductive pathway for aromatic ring degradation . The structural genes required for the conversion of 4-hydroxybenzoate (4-HBA) to benzoyl-CoA by Rhodopseudomonas palustris have been identified . Here we describe a regulatory gene, hbaR, that is part of the 4-HBA degradation gene cluster . An hbaR mutant that was constructed was unable to grow anaerobically on 4-HBA . However, the mutant retained the ability to grow aerobically on 4-HBA by an oxygen-requiring pathway distinct from the anaerobic route of 4-HBA degradation . The effect of the HbaR protein on expression of hbaA encoding 4-HBA-CoA ligase, the first enzyme for 4-HBA degradation, was investigated by using hbaA::'lacZ transcriptional fusions . HbaR was required for a 20-fold induction of beta-galactosidase activity that was observed with a chromosomal hbaA::'lacZ fusion when cells grown anaerobically on succinate were switched to anaerobic growth on succinate and 4-HBA . HbaR also activated expression from a plasmid-borne hbaA-'lacZ fusion when it was expressed in aerobically grown Pseudomonas aeruginosa cells, indicating that the activity of this regulator is not sensitive to oxygen . The deduced amino acid sequence of HbaR indicates that it is a member of the FNR-CRP superfamily of regulatory proteins . It is most closely related to transcriptional activators that are involved in regulating nitrate reduction . Previously, it has been shown that R . palustris has an FNR homologue, called AadR, that is also required for 4-HBA degradation . Our evidence indicates that AadR activates expression of hbaR in response to anaerobiosis and that HbaR, in turn, activates expression of 4-HBA degradation in response to 4-HBA as an effector molecule. FEMS Microbiol Lett, 2000 Jan 1, 182(1), 111 - 7 Analysis of in vivo substrate specificity of the PHA synthase from Ralstonia eutropha: formation of novel copolyesters in recombinant Escherichia coli; Antonio RV et al.; In order to investigate the in vivo substrate specificity of the type I polyhydroxyalkanoate (PHA) synthase from Ralstonia eutropha, we functionally expressed the PHA synthase gene in various Escherichia coli mutants affected in fatty acid beta-oxidation and the wild-type . The PHA synthase gene was expressed either solely (pBHR70) or in addition to the R . eutropha genes encoding beta-ketothiolase and acetoacetyl-coenzyme A (CoA) reductase comprising the entire PHB operon (pBHR68) as well as in combination with the phaC1 gene (pBHR77) from Pseudomonas aeruginosa encoding type II PHA synthase . The fatty acid beta-oxidation route was employed to provide various 3-hydroxyacyl-CoA thioesters, depending on the carbon source, as in vivo substrate for the PHA synthase . In vivo PHA synthase activity was indicated by PHA accumulation and substrate specificity was revealed by analysis of the comonomer composition of the respective polyester . Only in recombinant E . coli fad mutants harboring plasmid pBHR68, the R . eutropha PHA synthase led to accumulation of poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (poly(3HB-co-3HO)) and poly(3HB-co-3HO-co-3-hydroxydodecanoate (3HDD)), when octanoate and decanoate or dodecanoate were provided as carbon source, respectively . Coexpression of phaC1 from P . aeruginosa indicated and confirmed the provision of PHA precursor via the beta-oxidation pathway and led to the accumulation of a blend of two different PHAs in the respective E . coli strain . These data strongly suggested that R . eutropha PHA synthase accepts, besides the main substrate 3-hydroxybutyryl-CoA, also the CoA thioesters of 3HO and 3HDD. Electrophoresis, 1999 Dec, 20(18), 3580 - 8 The microbial proteome database--an automated laboratory catalogue for monitoring protein expression in bacteria; Cordwell SJ et al.; Laboratories devoted to high-throughput characterisation of purified proteins arrayed via two-dimensional (2-D) gel electrophoresis face an arduous task in maintaining a centralised and constantly evolving record of information relating to the characterisation of proteins and their responses following biological challenges . The Microbial Proteome Database (MPD) has been conceived as an in-house resource for complementing the plethora of genomic databases available for such organisms . The database utilises commercially available software to provide an electronic 'lab book' of information obtained daily from 2-D electrophoresis gels, image analysis packages, protein characterisation methodologies, and biological experimentation . The MPD begins from a single 2-D gel image (a 2-D 'reference map') with clickable spots that link to a 'protein catalogue' (ProtCat) with spot information including protein identity, changes in expression determined under experimental conditions, cellular location, mass, and pI . The entry for each protein then contains further links to gel images corresponding to the presence of the particular protein within different subproteomes (as defined by the pH of narrow- and wide-range immobilised pH gradients or from differential extraction methods used to determine the location of the protein within a functional cell) . The database currently contains information from strains of three microbial species (Escherichia coil, Pseudomonas aeruginosa and Staphylococcus aureus) and 32 master gel images . The rapid accessibility of information obtained from microbial proteomes is an essential step towards the integrated analysis of these organisms at the gene, transcript, protein and functional levels and will aid in reducing turnaround times between sample preparation and the discovery of molecules of biological significance. Proc Natl Acad Sci U S A, 1999 Dec 21, 96(26), 15202 - 7 Lethal paralysis of Caenorhabditis elegans by Pseudomonas aeruginosa; Darby C et al.; Identification of host factors that interact with pathogens is crucial to an understanding of infectious disease, but direct screening for host mutations to aid in this task is not feasible in mammals . The nematode Caenorhabditis elegans is a genetically tractable alternative for investigating the pathogenic bacterium Pseudomonas aeruginosa . A P . aeruginosa toxin, produced at high cell density under control of the quorum-sensing regulators LasR and RhlR, rapidly and lethally paralyzes C . elegans . Loss-of-function mutations in C . elegans egl-9, a gene required for normal egg laying, confer strong resistance to the paralysis . Thus, activation of EGL-9 or of a pathway that includes it may lead to the paralysis . The molecular identity of egl-9 was determined by transformation rescue and DNA sequencing . A mammalian homologue of EGL-9 is expressed in tissues in which exposure to P . aeruginosa could have clinical effects. Plasmid, 2000 Jan, 43(1), 59 - 72 Integration-proficient plasmids for Pseudomonas aeruginosa: site-specific integration and use for engineering of reporter and expression strains; Hoang TT et al.; An improved method for integration of exogenous DNA fragments at a defined site within the genome of Pseudomonas aeruginosa was developed . The method relies on two integration-proficient vectors, mini-CTX1 and mini-CTX2 . These two vectors contain (1) a tetracycline (tet) selectable marker, (2) an oriT for conjugation-mediated plasmid transfer, (3) the pMB1-derived origin of replication, (4) a modified &phi;CTX integrase (int) gene, (5) a versatile multiple cloning site (MCS) flanked by T4 transcriptional termination sequences (Omega elements), and (6) the &phi;CTX attachment site . The MCS and Omega elements are flanked by yeast Flp recombinase target sites that allow in vivo excision of unwanted plasmid backbone sequences, including tet and int, from the genome of integrants by Flp recombinase . In the mini-CTX2 vector int transcription is driven from the strong trc promoter, which is regulated by the Lac repressor that is encoded by lacI(q) also contained on the plasmid . Upon conjugal transfer, mini-CTX1 and mini-CTX2 integrated at frequencies of 10(-8) and 10(-7), respectively . The usefulness of the integration vectors for gene fusion analyses was demonstrated by chromosomal insertion of autoinducer (AI)-regulated lasB-lacZ and rhlA-lacZ fusions into wild-type and AI synthase mutants . In wild-type, the fusions responded in a cell density-dependent manner and expression of both fusions was either greatly reduced or abolished in AI synthase mutants . Finally, an expression cassette containing the T7 polymerase gene under Lac repressor control was constructed, integrated into the P . aeruginosa chromosome, and used to express the hexahistidine-tagged P . aeruginosa AI synthase RhlI . J Cataract Refract Surg, 1999 Dec, 25(12), 1615 - 9 Early- versus late-onset infectious keratitis after radial and astigmatic keratotomy: clinical spectrum in a referral practice; Heidemann DG et al.; PURPOSE: To compare the clinical characteristics of early- versus late-onset keratitis after radial keratotomy (RK) and astigmatic keratotomy (AK) . SETTING: Referral subspecialty practice . METHODS: This retrospective review comprised 19 patients with infectious keratitis after RK and AK . Early- versus late-onset groups were analyzed for predisposing conditions; infiltrate location, size, and depth; microbiologic data; and final visual outcome . RESULTS: Ten patients in the early-onset group developed keratitis within a mean of 7.4 days after surgery (range 3 to 14 days) . Nine patients in the late-onset group developed keratitis a mean of 5.4 years after surgery (range 1.5 to 15.0 years) . Staphylococcus aureus was the predominant organism in the early-onset group and Pseudomonas aeruginosa in the late-onset group . In the early-onset group, most infiltrates occurred in the paracentral aspect of the RK incision and extended to the middle or posterior stroma . In the late-onset group, most infiltrates occurred in the peripheral portion of the RK incision and were localized to the superficial stroma . A hypopyon was present in 7 of 10 ulcers in the early group and in 1 of 9 in the late group . Two patients in the early group developed endophthalmitis . Most patients in the late-onset group had incisional pseudocysts; 2 had other risk factors for keratitis . Final visual acuity was 20/40 or better in 7 of 10 patients in the early group and in 8 of 9 patients in the late group . CONCLUSIONS: Early-onset corneal ulcers after incisional refractive keratotomy were usually paracentral and deep, whereas late-onset ulcers were usually peripheral and superficial . Despite the predominance of Staphylococcus and Pseudomonas in the early- and late-onset groups, respectively, a variety of organisms may be responsible for infections in keratotomy incisions. J Trauma, 1999 Dec, 47(6), 1052 - 7; discussion 1057-9 Burn injury with infection alters prostaglandin E2 synthesis and metabolism; Hahn EL et al.; OBJECTIVE: The aim of this study was to examine the relationship between prostaglandin synthesis and prostaglandin degradation in a model of burn injury with infection . METHODS: Male B2D6F1 mice were assigned to control, burn (16% dorsal scald burn), or burn with infection (burn with topical application of 1,000 colony forming units of Pseudomonas aeruginosa) groups . Lung tissue was harvested at 1, 2, and 3 days after burn injury and subsequently processed for total RNA and protein . Northern and Western blot analyses were used to examine differences in cyclooxygenase 2 (COX-2) and prostaglandin 15-OH dehydrogenase (PGDH) protein and mRNA expression . Total RNA was probed with the riboprobe for murine PGDH and COX-2 and the 100,000g protein fraction was immunoblotted by using an rabbit anti-murine PGDH and anti-murine COX-2 antibody . RESULTS: COX-2 expression was elevated in the burn with infection animals on day 1 and day 2 after burn injury . At these time points in the burn + infection group, PGDH was significantly depressed . Burn injury increased COX-2 expression on day 1, but by day 2, COX-2 expression had decreased to control values . A corresponding increase in PGDH expression was observed on day 2 in the burned mice . The mRNA expression of COX-2 was followed by a similar increase in COX-2 protein expression at all time points in the injured animals . This was not the case with PGDH expression . On day 1, PGDH mRNA expression was depressed in the burn with infection mice with no change in PGDH protein expression . This finding indicates that PGDH is subject to regulation at both the transcriptional and posttranscriptional levels . CONCLUSION: Burn wound infection depressed both PGDH mRNA and protein expression and increased COX-2 mRNA and protein expression . Therefore, increases in circulating prostaglandin E2 levels during septic injury are derived from alterations in synthesis and degradation of prostaglandin E2. Salud Publica Mex, 1999, 41 Suppl 1, S38 - 43 {Epidemic of pneumonia associated with mechanical ventilation in Mérida, Yucatán}; Zaidi M et al.; OBJECTIVE: To determine the main epidemiological, clinical, and microbiologic characteristics of an outbreak of ventilator-associated pneumonia at an intensive care unit in Yucatan . MATERIAL AND METHODS: An 11-month prospective and observational study was designed to determine incidence, mortality, potential reservoirs, etiologic agents and antibiotic susceptibility patterns . RESULTS: The incidence of ventilator-associated pneumonia was 74% . The crude mortality rate was 88% compared to a 19.5% expected-mortality rate . Gram-negative bacteria were isolated from 98% of the cultures, of which 46% were susceptible to third generation cephalosporins, 59% to fourth generation cephalosporins, 70% to ciprofloxacin and 100% to imipenem . Klebsiella pneumoniae and Pseudomonas aeruginosa were isolated from some of the ventilator circuits and the sink . CONCLUSIONS: The high incidence of pneumonia and associated mortality in our intensive care unit may be attributed to the absence of infection control measures and the high prevalence of multiresistant organisms which is related to antibiotic abuse. Presse Med, 1999 Nov 27, 28 Suppl 3, 9 - 10 {Neutropenia with fever}; Ben Ali A; CAUSAL GERMS: Over the last 10 years, hemotology units have seen many changes in the epidemiological pattern of infections in neutropenic patients, with a growing number of infections caused by Gram-positive germs . The number of septicemias due to multiresistant Gram-negative germs (Pseudomonas aeruginosa, Strenotrophomonas maltophilia) has however remained high . IMPACT OF THERAPEUTIC REGIMENS: Improved prognosis in neutropenic patients depends for a large part on careful management of septic episodes . As the risk of septicemia is strongly correlated with the degree of efficacy of antibiotic regimens, susceptibility data must always be examined when developing antibiotic protocols in units caring for neutropenic patients. J Pharmacol Exp Ther, 2000 Jan, 292(1), 88 - 95 Mercaptoethylguanidine inhibits the inflammatory response in a murine model of chronic infection with Pseudomonas aeruginosa; Wilmott RW et al.; Chronic airway inflammation induced by Pseudomonas aeruginosa is the eventual cause of respiratory failure in most people affected by cystic fibrosis . Recent evidence implicates the involvement of free radical and oxidant stress in the pathogenesis of the inflammatory injury . Here we report the efficacy of a novel experimental therapeutic, mercaptoethylguanidine (MEG), which has combined actions as a selective inhibitor of the inducible nitric oxide synthase and as a scavenger of peroxynitrite, a potent oxidant formed in the reaction of nitric oxide and superoxide radical . Chronic pulmonary infection was established in FVB/N mice by intratracheal administration of 10(5) colony-forming units of P . aeruginosa in agar beads . Treatment with MEG (10 mg/kg/dose every 8 h i.p.) inhibited weight loss in the first 3 days and reduced histologic injury at 8 days postinfection . MEG also reduced myeloperoxidase activity, a marker of neutrophil infiltration, at 8 days and concentrations of the proinflammatory cytokines interleukin-1beta, tumor necrosis factor-alpha, and macrophage inflammatory protein 2 in whole lung homogenates . MEG-treated animals and controls had similar perioperative mortality and comparable colony counts of P . aeruginosa at 8 days, indicating that MEG did not exacerbate infection . Our data suggest that MEG may be an effective immunomodulatory therapy of pulmonary inflammation induced by chronic infection. Infect Immun, 2000 Jan, 68(1), 403 - 6 ExoT of cytotoxic Pseudomonas aeruginosa prevents uptake by corneal epithelial cells; Cowell BA et al.; The presence of invasion-inhibitory activity that is regulated by the transcriptional activator ExsA of cytotoxic Pseudomonas aeruginosa has previously been proposed . The results of this study show that both ExoT and ExoS, known type III secreted effector proteins of P . aeruginosa that are regulated by ExsA, possess this activity . Invasion was reduced 94.4% by ExoT and 96.0% by ExoS . Invasion-inhibitory activity is not linked to ADP-ribosylation activity, at least for ExoS, since a noncatalytic mutant also inhibits uptake by an epithelial cell line (invasion was reduced 96 . 0% by ExoSE381A). Antimicrob Agents Chemother, 2000 Jan, 44(1), 205 - 6 Morphological change in Pseudomonas aeruginosa following antibiotic treatment of experimental infection in mice and its relation to susceptibility to phagocytosis and to release of endotoxin; Yokochi T et al.; The relationship between morphological changes in Pseudomonas aeruginosa following antibiotic treatment of experimental infection in mice, susceptibility to phagocytosis, and release of endotoxin was studied . The intraperitoneal administration of P . aeruginosa with imipenem or ceftazidime into mice induced morphological changes in the cells 2 h after injection . Round P . aeruginosa cells with imipenem treatment became susceptible to phagocytosis by peritoneal cells, whereas long filamentous cells with ceftazidime treatment were hardly phagocytized by peritoneal cells . The morphological changes also affected the plasma endotoxin level in the circulation. Immunopharmacology, 1999 Nov, 44(3), 223 - 31 Accelerated recovery from cyclophosphamide-induced leukopenia in mice administered a Japanese ethical herbal drug, Hochu-ekki-to; Kaneko M et al.; The effect of a Japanese ethical herbal drug, Hochu-ekki-to (HOT), on recovery from leukopenia induced by cyclophosphamide (CY) was investigated . Daily oral administration of 1000 mg/kg HOT into CY-treated mice significantly prevented decrease of leukocyte numbers in the peripheral blood and accelerated recovery from leukopenia . Ginsenoside Rgl extracted from Ginseng radix, a major herb of HOT, was one of the active ingredients . HOT increased numbers of neutrophils and monocytes in the peripheral blood compared with CY-treated control . Moreover, HOT augmented the resistance against Pseudomonas aeruginosa infection . The number of colony-forming units in the spleen (CFU-S) also increased in HOT-treated mice . The frequencies of IL-3-, GM-CSF- and IFN-gamma-producing cells increased in the spleen, bone marrow, liver and IEL on HOT treatment, and HOT clearly augmented the expressions of IL-3, GM-CSF and IFN-gamma mRNA in the spleen, bone marrow, liver and IEL except IL-3 and IFN-gamma mRNA in the IEL . These results suggest that HOT enhances the production of hematopoietic lymphokines, stimulates the proliferation of hematopoietic progenitor cells and consequently accelerates recovery from leukopenia in CY-treated mice . Additionally, IFN-gamma which HOT-augmented the production may contribute the protective effect against the bacterial infection by activating of phagocyte cells. Eur Respir J, 1999 Nov, 14(5), 1145 - 9 Human neutrophil lipocalin, a highly specific marker for acute exacerbation in cystic fibrosis; Eichler I et al.; Cystic fibrosis (CF) is characterized by the production of abnormally thick secretions in the airways, chronic bacterial endobronchial infections and a chronic, predominantly neutrophilic inflammatory response . Therefore, myeloperoxidase (MPO) and lactoferrin are frequently used as inflammatory markers . Recently, a new protein in the neutrophil granules, human neutrophil lipocalin (HNL) has been discovered . The aim of the present study was to investigate HNL in sera of patients with CF and its relation to MPO and lactoferrin as well as to acute pulmonary exacerbation . Serum concentrations of HNL, MPO and lactoferrin were determined in 42 patients with CF and in 25 healthy subjects . Patients with CF were divided into groups with and without acute pulmonary exacerbation (APE) and also with and without colonization with Pseudomonas aeruginosa (Pa) . Median serum levels of HNL (200.5 microg x L(-1)), MPO (595 microg x L(-1)) and lactoferrin (1,356.5 microg x L(-1)) were significantly increased in patients with CF compared to control subjects (57.7, 178 and 478 microg x L(-1), respectively; p<0.0001) . CF patients with APE had significantly increased serum concentrations of HNL (321 versus 97.7 microg x L(-1); p<0.0001), MPO (1,125 versus 300 microg x L(-1); p<0.005) and lactoferrin (4,936 versus 980 microg x L(-1); p<0.001) compared with patients in stable clinical condition . Similarly, patients colonized with Pa had significantly higher concentrations of HNL, MPO and lactoferrin than Pa negative patients . These results indicate that in patients with cystic fibrosis, serum concentrations of human neutrophil lipocalin are markedly increased with a strong relationship to myeloperoxidase and lactoferrin . Thus, determination of serum human neutrophil lipocalin concentrations may be another useful diagnostic tool to monitor neutrophil inflammation in cystic fibrosis . The more marked difference in human neutrophil lipocalin compared with myeloperoxidase concentrations with no overlap between patients with acute pulmonary exacerbation and those in stable condition even suggests that human neutrophil lipocalin may be a more sensitive and specific discriminator. J Antimicrob Chemother, 1999 Nov, 44(5), 689 - 91 In-vitro effects of a combination of antipseudomonal antibiotics against multi-drug resistant Pseudomonas aeruginosa; Oie S et al.; We evaluated the in-vitro effects of various combinations of five types of widely used antipseudomonal antibiotics (piperacillin, meropenem, ceftazidime, aztreonam and amikacin) against six Pseudomonas aeruginosa strains that were resistant to each of these antibiotics . Among two-drug combinations, the combinations of two beta-lactam antibiotics inhibited growth of one to three P . aeruginosa strains, while those of one beta-lactam antibiotic and amikacin inhibited growth of two to four strains . Among three-drug combinations, the combinations of three beta-lactam antibiotics inhibited growth of four to five strains, and those of two beta-lactam antibiotics and amikacin inhibited growth of five strains . These results suggest the potential usefulness of a combination of two beta-lactam antibiotics and amikacin or that of three beta-lactam antibiotics in treating multi-drug resistant P . aeruginosa infections. J Appl Microbiol, 1999 Nov, 87(5), 782 - 6 A kinetic study of the effect of hydrogen peroxide and peracetic acid against Staphylococcus aureus and Pseudomonas aeruginosa using the bioscreen disinfection method; Lambert RJ et al.; Hydrogen peroxide and peracetic acid at pH 4 were examined against Staphylococcus aureus and Pseudomonas aeruginosa using the published 'Bioscreen' technique of biocide analysis . The data were examined using either classical Chick-Watson (CW) log-linear disinfection kinetics or the empirical, non-linear time Hom model . In some cases, modelling the data with the classical CW method gave good linear correlations, in others, however, deviations from this model were observed . In such cases the Hom model proved an adequate descriptor of the data . The Bioscreen technique therefore gives data which can be analysed using the normal mechanistic and empirical models currently available. J Appl Microbiol, 1999 Nov, 87(5), 735 - 42 Specific variations of fatty acid composition of Pseudomonas aeruginosa ATCC 15442 induced by quaternary ammonium compounds and relation with resistance to bactericidal activity; Guerin-Mechin L et al.; The role of membrane fatty acid composition in the resistance of Pseudomonas aeruginosa ATCC 15442 to the bactericidal activity of Quaternary Ammonium Compounds (QACs) was investigated . The strain was grown in a medium with increasing concentrations of a QAC, benzyldimethyltetradecylammonium chloride (C14) and two non-QACs, sodium dichloroisocyanurate and tri-sodium phosphate . In the presence of C14 only, the strain was able to grow in concentrations higher than the minimal inhibitory concentration . As the strain adapted to C14, resistance to bactericidal activity of the same biocide increased . For the non-QACs, no change was noted when cells were grown in the presence of biocides . The C14-adapted cells showed variations in membrane fatty acid composition . A hierarchical clustering analysis was used to compare all fatty acid compositions of cultures in the presence, or not, of the three biocides used here and another QAC studied previously . The clusters obtained underlined specific variations of membrane fatty acids in response to the presence of QACs . Furthermore, with a simple linear regression analysis, a relationship was shown between the membrane fatty acids and the resistance developed by the strain against the bactericidal activity of C14. J Appl Microbiol, 1999 Nov, 87(5), 718 - 25 A comparison of the bactericidal efficacy of 18 disinfectants used in the food industry against Escherichia coli O157:H7 and Pseudomonas aeruginosa at 10 and 20 degrees C; Taylor JH et al.; A number of proprietary disinfectant products (18) used in the food industry were tested for their bactericidal efficacy against Pseudomonas aeruginosa and Escherichia coli O157:H7 at 20 and 10 degrees C according to the BS EN 1276 (1997) quantitative suspension test for the evaluation of bactericidal activity of chemical disinfectants and antiseptics used in food, industrial, domestic and institutional areas . At 20 degrees C, 13 products passed at their in-use concentration (under clean and dirty conditions) against Ps . aeruginosa and 15 passed against E . coli O157:H7 . The number of products passing the test at 10 degrees C was 11 and 14 for Ps . aeruginosa and E . coli O157:H7, respectively . The products exhibiting reduced efficacy at the lower temperature were amphoterics and quaternary ammonium compounds although some of these types of products were effective at both temperatures . Products that passed against Ps . aeruginosa generally also passed against E . coli O157:H7 . Taking all the results together, only 11 of the total of 18 products achieved a pass result under all the parameters tested . This work demonstrates the need for final verification of disinfectant efficacy by undertaking field trials in the food-processing environment in which the product is intended for use. J Biol Chem, 1999 Dec 17, 274(51), 36616 - 22 Molecular cloning, sequencing, and expression of the gene encoding alkaline ceramidase from Pseudomonas aeruginosa . Cloning of a ceramidase homologue from Mycobacterium tuberculosis; Okino N et al.; We previously reported the purification and characterization of a novel type of alkaline ceramidase from Pseudomonas aeruginosa strain AN17 (Okino, N., Tani, M., Imayama, S., and Ito, M . (1998) J . Biol . Chem . 273, 14368-14373) . Here, we report the molecular cloning, sequencing, and expression of the gene encoding the ceramidase of this strain . Specific oligonucleotide primers were synthesized using the peptide sequences of the purified ceramidase obtained by digestion with lysylendopeptidase and used for polymerase chain reaction . DNA fragments thus amplified were used as probes to clone the gene encoding the ceramidase from a genomic library of strain AN17 . The open reading frame of 2,010 nucleotides encoded a polypeptide of 670 amino acids including a signal sequence of 24 residues, 64 residues of which matched the amino acid sequence determined for the purified enzyme . The molecular weight of the mature enzyme was estimated to be 70,767 from the deduced amino acid sequence . Expression of the ceramidase gene in Escherichia coli, resulted in production of a soluble enzyme with the identical N-terminal amino acid sequence . Recombinant ceramidase was purified to homogeneity from the lysate of E . coli cells and confirmed to be identical to the Pseudomonas enzyme in its specificity and other enzymatic properties . No significant sequence similarities were found in other known functional proteins including human acid ceramidase . However, we found a sequence homologous to the ceramidase in hypothetical proteins encoded in Mycobacterium tuberculosis, Dictyostelium discoideum, and Arabidopsis thaliana . The homologue of the ceramidase gene was thus cloned from an M . tuberculosis cosmid and expressed in E . coli, and the gene was demonstrated to encode an alkaline ceramidase . This is the first report for the cloning of an alkaline ceramidase. J Biol Chem, 1999 Dec 17, 274(51), 36369 - 72 The N-terminal domain of Pseudomonas aeruginosa exoenzyme S is a GTPase-activating protein for Rho GTPases; Goehring UM et al.; Pseudomonas aeruginosa exoenzyme S (ExoS) is a bifunctional cytotoxin . The ADP-ribosyltransferase domain is located within the C terminus part of ExoS . Recent studies showed that the N terminus part of ExoS (amino acid residues 1-234, ExoS(1-234)), which does not possess ADP-ribosyltransferase activity, stimulates cell rounding when transfected or microinjected into eukaryotic cells . Here we studied the effects of ExoS(1-234) on nucleotide binding and hydrolysis by Rho GTPases . ExoS(1-234) (100-500 nM) did not influence nucleotide exchange of Rho, Rac, and Cdc42 but increased GTP hydrolysis . A similar increase in GTPase activity was stimulated by full-length ExoS . Half-maximal stimulation of GTP hydrolysis by Rho, Rac, and Cdc42 was observed at 10-11 nM ExoS(1-234), respectively . We identified arginine 146 of ExoS to be essential for the stimulation of GTPase activity of Rho proteins . These data identify ExoS as a GTPase-activating protein for Rho GTPases. Nihon Kokyuki Gakkai Zasshi, 1999 Sep, 37(9), 739 - 42 {Primary ciliary dyskinesia treated with living-donor lobar lung transplantation}; Yamamoto H et al.; We report a case of primary ciliary dyskinesia in which a living-donor lobar lung transplant was performed . A 24-year-old woman with a diagnosis of primary ciliary dyskinesia and bronchiectasis was admitted to Shinshu University Hospital because of persistent dyspnea and pyrexia over a period of 4 months . Although she was given various antibiotics, neutrophilia, elevated plasma C-reactive protein (CRP) levels, and respiratory failure persisted . Chest roentgenograms and computed tomography disclosed severe bronchiectasis and diffuse infiltrative shadows in both lung fields . Pseudomonas aeruginosa was detected in a sputum culture . Although a variety of conventional therapies were administered, the patient's oxygenation progressively deteriorated . She was intubated and assisted by mechanical ventilation . The patient and her family proposed lung transplantation, and we concluded that a living-donor lobar lung transplant would be a suitable treatment for her disease . We transported the patient to Okayama University Hospital by helicopter 10 days after intubation . A living-donor lobar lung transplant was successfully performed with lung tissues donated by the patient's mother and sister for each transplant site. Nihon Kokyuki Gakkai Zasshi, 1999 Sep, 37(9), 699 - 703 {A case of common variable immunodeficiency that responded to long-term erythromycin chemotherapy}; Maeda K et al.; A 32-year-old woman with common variable immunodeficiency (CVID) accompanied by sinopulmonary infection was evaluated for purulent sputum, cough, and nasal obstruction that did not respond to regular intravenous immunoglobin (IVIG) infusion . Chest X-ray films revealed bronchiectasis affecting both lung bases, and a bacteriological examination of sputum was positive for Pseudomonas aeruginosa . Long-term chemotherapy with erythromycin (EM) was started, and the patient's respiratory symptoms gradually subsided . Sinopulmonary infection is the dominant clinical complication in patients with CVID . This case suggested that long-term EM chemotherapy is useful for the treatment of IVIG-refractory sinopulmonary infection associated with CVID. Nihon Kokyuki Gakkai Zasshi, 1999 Sep, 37(9), 673 - 9 {Interleukin-8 and airway inflammation}; Inoue H; Airway inflammation is a prominent feature of chronic obstructive diseases of the airways, including asthma, bronchiectasis, chronic bronchitis, and diffuse panbronchiolitis . Neutrophils are implicated in the pathogenesis of these diseases . The present review discusses the role of interleukin-8 (IL-8), a neutrophil chemo-attractant, in neutrophil accumulation in the airways, and the mechanisms of inducing IL-8 expression . IL-8 presents in the sputum of patients with inflammatory airway diseases, and accounts in large part for the chemo-attractant activity present . Focusing on Pseudomonas aeruginosa as the stimulus, it was discovered that when a supernatant of bacterial culture is introduced into the airways in vivo, bacterial products induce IL-8 expression in surface airway epithelial cells and the recruitment of neutrophils into the airways . The neutrophil chemotactic activity of the airway fluid was inhibited by an IL-8 antibody . The luminal IL-8 concentration increased in response to instillation of bacteria, and an inhibitor of neutrophil recruitment markedly reduced the IL-8 levels . From these results, it was speculated that bacteria-induced neutrophil accumulation in the airways involves a cascade of events, and that early neutrophil recruitment in response to bacteria is due to epithelium-derived IL-8, while the amplification of the response is due, at least in part, to IL-8 induction in the neutrophils themselves. Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi, 1996 May, 29(2), 90 - 9 Comparison of three typing methods for Pseudomonas aeruginosa; Chen CH et al.; Fifty-seven independent isolates of Pseudomonas aeruginosa from blood specimens were typed with 3 different methods: ribotyping, random amplified polymorphic DNA (RAPD) typing, and pyocin typing . Ribotyping was performed by probing the rRNA genes of genomic DNA that was digested separately with 4 different restriction enzymes . Digestion of DNA from 57 P . aeruginosa isolates with BamHI, ClaI, EcoRI, and PstI produced 4, 4, 6, and 7 patterns, respectively . As a result, ribotyping classified the 57 isolates into 22 types . Six new ribotypes that had not been described previously were found . One BamHI, 1 ClaI, 2 EcoRI, and 2 PstI patterns were novel . RAPD typing was performed with two different polymerase chain reaction (PCR) primers (RAPD1 and RAPD2) . Both primers classified the 57 isolates into 15 RAPD types and produced identical patterns . The pyocin typing method classified the 57 isolates into 10 types . According to the results obtained in this study, the ribotyping has a discriminatory index of 0.865, RAPD, 0.785, and pyocin typing, 0.676, respectively . The ribotyping method was the most effective among the 3 methods compared for typing P . aeruginosa isolates. Rinsho Byori, 1999 Nov, 47(11), 1064 - 9 {Clinical analysis of Pseudomonas aeruginosa bacteremia}; Kumasaka K et al.; To determine the outcome of Pseudomonas aeruginosa bacteremia and to identify risk factors for these infections in our University hospital, 46 cases (65 episodes) of Pseudomonas aeruginosa bacteremia were retrospectively investigated . The most frequent underlying diseases or cases were from Emergency and Critical care center (18 cases, including 11 case of cerebrovascular accident and head injury) followed by hematologic malignancies (11 cases) but none of the HIV infection was included in this study . The overall crude mortality rate was 50% and mortality rate within the first 1 week was 17% . Clinical analysis of those cases revealed that possible risk factors were neutropenia, sever sepsis and prior use of antibiotics (antipseudomonal antibiotics were administered before positive blood culture episodes in 90% cases) . But these factors were not statistically significant between dead and survived cases . CONCLUSION: To improve the prognosis of Pseudomonas aeruginosa bacteremia, we must change the management of the hospital infection, such as the more rational use of new antipseudomonal antibiotics and the more clean and reasonable management of central venous catheters. Am J Respir Crit Care Med, 1999 Dec, 160(6), 2040 - 7 IL-10 attenuates excessive inflammation in chronic Pseudomonas infection in mice; Chmiel JF et al.; Cystic fibrosis (CF) lung disease is characterized by an excessive inflammatory response associated with chronic Pseudomonas aeruginosa endobronchial infection . Compared with bronchoalveolar lavage fluid from healthy subjects, lavage fluid from patients with CF contains elevated proinflammatory cytokines but negligible amounts of the anti-inflammatory cytokine interleukin-10 (IL-10) . We sought to determine whether IL-10 deficiency results in increased local and systemic morbidity in mice with chronic endobronchial infection with P . aeruginosa embedded in agar beads and to determine if exogenous IL-10 might reduce these effects . Infected IL-10 knockout mice had more severe weight loss (p = 0.04) and increased area of lung inflammation (28 +/- 4 versus 10 +/- 2%, p < 0.002) but no alterations in bacterial burden compared with wild-type mice . Infected CD-1 mice treated with IL-10 had improved survival (p = 0 . 035), less severe weight loss (p < 0.005), fewer bronchoalveolar lavage neutrophils (3 x 10(5)/ml versus 5 x 10(6)/ml, p < 0.02), and decreased area of lung inflammation (11 +/- 2 versus 35 +/- 7%, p < 0.01) but no alterations in bacterial burden compared with placebo-treated mice . These data suggest that IL-10 is an important regulator of the inflammatory response to P . aeruginosa endobronchial infection and that further investigation into the use of IL-10 in CF is warranted. Tohoku J Exp Med, 1999 Jul, 188(3), 271 - 3 Usefulness of procalcitonin in Pseudomonas burn wound sepsis model; Nakae H et al.; Procalcitonin (PCT), a precursor of calcitonin, and endotoxin were determined in the burn wound sepsis model in which 21 Sprague-Dawley rats were scalded approximately 30% on their back . On day 2 post burn, the wounds were inoculated 1 x 10(8) colony-forming units of Pseudomonas aeruginosa . On day 5 post burn P . aeruginosa was detected by blood culture in 10 of the 21 rats (47.6%) . The mortality rate 7 days after burn was 90.5% . Significant correlations were observed between serum endotoxin levels and serum PCT levels on day 5 post burn (r = 0.860, p<0.001) . It was suggested that endotoxin may induce the release of PCT and that measuring the levels of PCT may be useful in diagnosing burn wound sepsis. Biochem J, 1999 Dec 15, 344 Pt 3, 845 - 9 Identification of an anti-mycobacterial domain in NK-lysin and granulysin; Andreu D et al.; NK-lysin and granulysin are homologous cationic anti-bacterial peptides produced by pig and human cytolytic lymphocytes, respectively . The solution structure of NK-lysin comprises five amphipathic alpha-helices . To investigate the properties of a helix-loop-helix region postulated to be a membrane-docking part of NK-lysin, we synthesized 22- and 29-residue peptides reproducing this region for both NK-lysin and granulysin . CD spectroscopy of the synthetic peptides in a liposomal solution showed spectra typical of alpha-helical peptides . The peptides were active against Gram-positive and Gram-negative bacteria, with the two NK-lysin peptides showing higher anti-bacterial activities than the two from granulysin . One NK-lysin peptide was active against Pseudomonas aeruginosa and Staphylococcus aureus, two organisms against which NK-lysin is inactive . Granulysin peptides were inactive against these bacteria, in contrast with granulysin, which is known to be active against them . Both NK-lysin and all synthetic analogues killed Mycobacterium tuberculosis and K562 tumour cells, but did not display haemolytic activity . These results identify a potent anti-mycobacterial domain in NK-lysin and granulysin consisting of a 22-residue (helix 3) sequence plus a disulphide-constrained loop. J Agric Food Chem, 1999 Oct, 47(10), 4297 - 300 Antibacterial activity of turmeric oil: a byproduct from curcumin manufacture; Negi PS et al.; Curcumin, the yellow color pigment of turmeric, is produced industrially from turmeric oleoresin . The mother liquor after isolation of curcumin from oleoresin contains approximately 40% oil . The oil was extracted from the mother liquor using hexane at 60 degrees C, and the hexane extract was separated into three fractions using silica gel column chromatography . These fractions were tested for antibacterial activity by pour plate method against Bacillus cereus, Bacillus coagulans, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa . Fraction II eluted with 5% ethyl acetate in hexane was found to be most active fraction . The turmeric oil, fraction I, and fraction II were analyzed by GC and GC-MS . ar-Turmerone, turmerone, and curlone were found to be the major compounds present in these fractions along with other oxygenated compounds. Mol Gen Genet, 1999 Oct, 262(3), 552 - 8 Characterization of a high-affinity phenol hydroxylase from Comamonas testosteroni R5 by gene cloning, and expression in Pseudomonas aeruginosa PAO1c; Teramoto M et al.; Comamonas testosteroni strain R5 is a phenol-degrading bacterium which expresses a phenol-oxygenating activity that is characterized by low Ks (the apparent half-saturation constant in Haldane's equation) and low K(SI) (the apparent inhibition constant) values . We have now cloned the gene cluster encoding a phenol hydroxylase (phcKLMNOP) and its cognate regulator (phcR) from strain R5 . Transformation of Pseudomonas aeruginosa PAO1c (Phenol Catechol+) with pROR502, a derivative of pRO1614 containing the cloned genes, confers the ability to grow on phenol as the sole carbon source . The Ks and K(SI) values for the phenol-oxygenating activity of PAO1c(pROR502) are almost identical to those of strain R5, suggesting that the phcKLMNOP genes encode the major phenol hydroxylase in strain R5 . A phylogenetic analysis shows the phenol hydroxylase from strain R5 to be more closely related to toluene/benzene-2-monooxygenase (Tb2m) from Pseudomonas sp . JS150 than to the phenol hydroxylases from P . putida CF600 and BH, or to the phenol hydroxylase from Ralstonia eutropha E2 . Analysis of the substrate specificity of PAO1c(pROR502) and PAO1c derivatives expressing phenol hydroxylase from P . putida BH or from R . eutropha E2 indicates that these phenol hydroxylases catalyze the oxidation not only of phenol and cresols but also of toluene and benzene. J Antimicrob Chemother, 1999 Oct, 44(4), 537 - 40 Contribution of the MexAB-OprM multidrug efflux system to the beta-lactam resistance of penicillin-binding protein and beta-lactamase-derepressed mutants of Pseudomonas aeruginosa; Srikumar R et al.; Deletion of the mexAB-oprM multidrug efflux operon substantially compromised the beta-lactam resistance of beta-lactamase-derepressed mutants of Pseudomonas aeruginosa, although it had only a modest impact on resistance of a penicillin-binding protein mutant . This highlights the multifactorial nature of beta-lactam resistance in this organism . Moreover, the contribution of efflux to the net resistance seen in some beta-lactam-resistant mutants suggests that inhibition of MexAB-OprM-mediated drug efflux might be an effective approach to overcoming beta-lactam resistance attributed to efflux as well as to other mechanisms of beta-lactam resistance. Folia Microbiol (Praha), 1999, 44(2), 187 - 90 Antibacterial effect of some substituted tricyclic quinazolines and their synthetic precursors; Jantova S et al.; Eleven substituted tricyclic quinazolines and their synthetic precursors were tested for antibacterial effects . 3-Chloromethylcarbonyl-2-methylquinazolin-4-thione and 5-phenyl-2,3-dihydro-1,2,4-triazolo{4,3-c}quinazolin-3-one had the highest antibacterial effect against Bacillus subtilis, the MIC values being 50 mg/L . Two tested derivatives were more active against Pseudomonas aeruginosa than ampicillin, the IC50 values being 80 and 100 mg/L . The most effective derivatives contained in the structure generally pharmacologically active chromophores--methyl group in position 2 and a chloromethyl configuration on the carbonyl group in position 3. Pediatr Pulmonol, 1999 Dec, 28(6), 449 - 50 If you can't stand the rash, get out of the kitchen: an unusual adverse reaction to ciprofloxacin; Jaffe A et al.; Ciprofloxacin, a quinolone antibiotic, is used to treat a wide variety of infections including Pseudomonas aeruginosa in patients with cystic fibrosis (CF) . Photosensitivity is a well-known complication of treatment with this group of antibiotics, and it is more common in patients with CF . We report on a case of photosensitivity induced by indoor fluorescent strip-lighting (spectral range, 295-760 nm) in a 12-year-old girl with CF treated with ciprofloxacin . This type of lighting emits UVA rays (320-400 nm) which cause skin damage in the presence of sensitizing agents . Patients taking ciprofloxacin are usually advised to protect their skin from direct sunlight . We suggest that more attention should be paid to indoor sources of UV light . Invest Ophthalmol Vis Sci, 1999 Dec, 40(13), 3168 - 76 Evidence for TIMP-1 protection against P . aeruginosa-induced corneal ulceration and perforation; Kernacki KA et al.; PURPOSE: To determine the biological significance of individual endogenous tissue inhibitors of metalloproteinases (TIMPs) in protection against tissue destruction using a Pseudomonas aeruginosa-induced model of corneal ulceration . METHODS: Corneal TIMP-1, -2, and -3 mRNA levels were compared between young adult (resistant) and aged (susceptible) mice challenged with P . aeruginosa . Resistant mice that demonstrated greater amounts of an individual TIMP were treated with polyclonal antibody (pAb) to that TIMP . To determine whether TIMP neutralization exacerbated P . aeruginosa-induced corneal disease, TIMP pAb- and normal rabbit serum (NRS)- (control) treated mice were examined macroscopically and histopathologically after infection . Corneal neutrophil (PMN) myeloperoxidase (MPO) levels also were examined in these mice . RESULTS: Greater amounts of TIMP-1 mRNA only were found in corneas of resistant versus suscep tible mice after P . aeruginosa challenge . Systemic treatment of resistant mice with TIMP-1 pAb resulted in corneal perforation by 5 to 7 days after infection (PI) . Histopathologic evaluation of corneal tissues from TIMP-1 pAb- versus NRS-treated mice confirmed that TIMP-1 pAb treatment resulted in extensive stromal dissolution . This treatment also was associated with loss of epithelium within the central cornea . Both the histopathology and PMN MPO enzyme assays also showed an increase in corneal PMN number following TIMP-1 pAb treatment . CONCLUSIONS: These studies provide evidence that, after P . aeruginosa infection, adequate endogenous expression of TIMP-1 in cornea protects against extensive corneal tissue destruction . The protective effects of TIMP-1 may be multifactorial . In addition to directly protecting extracellular matrix components from active matrix metalloproteinases, TIMP-1 may either directly or indirectly influence recruitment of PMNs into infected cornea . Finally, TIMP-1 also may affect wound healing and resurfacing of the corneal epithelium. Cytobios, 1999, 99(392), 183 - 9 Pseudomonas aeruginosa (GRC1) as a strong antagonist of Macrophomina phaseolina and Fusarium oxysporum; Gupta CP et al.; A plant growth promotory bacterial strain, isolated from the potato rhizosphere, was characterized as Pseudomonas aeruginosa (GRC1) . The isolate produced an hydroxamate type of siderophore after 48 h of incubation on tryptic soy medium under iron deficient conditions . The in vitro antifungal activity of P . aeruginosa was tested against two soil-borne plant pathogens, Macrophomina phaseolina and Fusarium oxysporum . The antagonistic behaviour of the isolate was tested by dual culture technique . The growth inhibition of M . phaseolina and F . oxysporum was 74.1% and 70.5%, respectively, after 5 days of incubation . The production of hydrocyanic acid and indole acetic acid was also recorded under normal growth conditions. Eur J Biochem, 1999 Dec, 266(3), 986 - 96 Proteome mapping, mass spectrometric sequencing and reverse transcription-PCR for characterization of the sulfate starvation-induced response in Pseudomonas aeruginosa PAO1; Quadroni M et al.; A set of proteins induced in Pseudomonas aeruginosa PAO1 during growth in the absence of sulfate was characterized by differential two-dimensional electrophoresis and MS . Thirteen proteins were found to be induced de novo or upregulated in P . aeruginosa grown in a succinate/salts medium with sodium cyclohexylsulfamate as the sole sulfur source . Protein spots excised from the two-dimensional gels were analysed by N-terminal Edman sequencing and MS sequencing (MS/MS) of internal protein fragments . The coding sequences for 11 of these proteins were unambiguously identified in the P . aeruginosa genome sequence . Expression of these genes was investigated by reverse transcription-PCR, which confirmed that repression in the presence of sulfate was acting at a transcriptional level . Three classes of sulfur-regulated proteins were found . The first class (five proteins) were high-affinity periplasmic solute-binding proteins with apparent specificity for sulfate and sulfonates . A second class included enzymes involved in sulfonate and sulfate ester metabolism (three proteins) . The remaining three proteins appeared to be part of a more general stress response, and included two antioxidant proteins and a putative lipoprotein . This study demonstrates the power of the proteomics approach for direct correlation of the responses of an organism to an environmental stimulus with the genetic structures responsible for that response, and the application of reverse transcription-PCR significantly increases the conclusions that can be drawn from the proteomic study. Br J Surg, 1999 Nov, 86(11), 1433 - 6 Improved management of infrainguinal bypass graft infection with methicillin-resistant Staphylococcus aureus; Chalmers RT et al.; BACKGROUND: There is considerable debate over the management of infected infrainguinal grafts . This report describes recent experience in this field and documents the change in clinical practice needed to deal with methicillin-resistant Staphylococcus aureus (MRSA) . METHODS: All infected infrainguinal grafts between January 1991 and July 1997 were reviewed . In the light of the findings, clinical practice was modified considerably . A further 1 year was audited prospectively up to August 1998 . RESULTS: Twenty-six patients were treated for 27 infrainguinal graft infections (25 prosthetic, two vein) . Twenty were treated by complete graft excision as the initial therapy; graft preservation was attempted in six patients . Before 1995, the infecting organisms were predominantly Pseudomonas aeruginosa or methicillin-sensitive staphylococci . Subsequently all 14 patients treated up to 1997 had infection with MRSA . The overall amputation rate was 17 of 26; ten amputations were in patients with MRSA . Four patients died, all with MRSA sepsis . As a result of this experience a policy of complete isolation was adopted for all patients infected with MRSA . In the 12 months since this policy was introduced, 77 infrainguinal grafts (61 vein, 16 prosthetic) have been inserted . Two grafts (3 per cent) have become infected, necessitating graft excision and amputation . CONCLUSION: MRSA infection of an infrainguinal graft is a serious complication with high associated amputation and mortality rates . Isolation and barrier nursing appeared to contain the problem. Antimicrob Agents Chemother, 1999 Dec, 43(12), 3033 - 5 Beneficial effect of adjunctive azithromycin in treatment of mucoid Pseudomonas aeruginosa pneumonia in the murine model; Nicolau DP et al.; While a time-kill methodology noted no appreciable improvement in bactericidal activity with the addition of azithromycin (AZM) to a ceftazidime (CAZ) regimen, data from the murine pneumonia model showed that the addition of AZM significantly improved survival compared to treatment with CAZ alone . These data suggest that AZM might be a useful adjunctive therapy in the management of pneumonia resulting from mucoid isolates of Pseudomonas aeruginosa. Antimicrob Agents Chemother, 1999 Dec, 43(12), 2975 - 83 Characterization of a Pseudomonas aeruginosa efflux pump contributing to aminoglycoside impermeability; Westbrock-Wadman S et al.; Pseudomonas aeruginosa can employ many distinct mechanisms of resistance to aminoglycoside antibiotics; however, in cystic fibrosis patients, more than 90% of aminoglycoside-resistant P . aeruginosa isolates are of the impermeability phenotype . The precise molecular mechanisms that produce aminoglycoside impermeability-type resistance are yet to be elucidated . A subtractive hybridization technique was used to reveal gene expression differences between PAO1 and isogenic, spontaneous aminoglycoside-resistant mutants of the impermeability phenotype . Among the many genes found to be up-regulated in these laboratory mutants were the amrAB genes encoding a recently discovered efflux system . The amrAB genes appear to be the same as the recently described mexXY genes; however, the resistance profile that we see in P . aeruginosa is very different from that described for Escherichia coli with mexXY . Direct evidence for AmrAB involvement in aminoglycoside resistance was provided by the deletion of amrB in the PAO1-derived laboratory mutant, which resulted in the restoration of aminoglycoside sensitivity to a level nearly identical to that of the parent strain . Furthermore, transcription of the amrAB genes was shown to be up-regulated in P . aeruginosa clinical isolates displaying the impermeability phenotype compared to a genotypically matched sensitive clinical isolate from the same patient . This suggests the possibility that AmrAB-mediated efflux is a clinically relevant mechanism of aminoglycoside resistance . Although it is unlikely that hyperexpression of AmrAB is the sole mechanism conferring the impermeability phenotype, we believe that the Amr efflux system can contribute to a complex interaction of molecular events resulting in the aminoglycoside impermeability-type resistance phenotype. Antimicrob Agents Chemother, 1999 Dec, 43(12), 2877 - 80 Activities of tobramycin and six other antibiotics against Pseudomonas aeruginosa isolates from patients with cystic fibrosis; Shawar RM et al.; The in vitro activity of tobramycin was compared with those of six other antimicrobial agents against 1,240 Pseudomonas aeruginosa isolates collected from 508 patients with cystic fibrosis during pretreatment visits as part of the phase III clinical trials of tobramycin solution for inhalation . The tobramycin MIC at which 50% of isolates are inhibited (MIC(50)) and MIC(90) were 1 and 8 microg/ml, respectively . Tobramycin was the most active drug tested and also showed good activity against isolates resistant to multiple antibiotics . The isolates were less frequently resistant to tobramycin (5.4%) than to ceftazidime (11.1%), aztreonam (11.9%), amikacin (13.1%), ticarcillin (16.7%), gentamicin (19.3%), or ciprofloxacin (20.7%) . For all antibiotics tested, nonmucoid isolates were more resistant than mucoid isolates . Of 56 isolates for which the tobramycin MIC was > or = 16 microg/ml and that were investigated for resistance mechanisms, only 7 (12.5%) were shown to possess known aminoglycoside-modifying enzymes; the remaining were presumably resistant by an incompletely understood mechanism often referred to as "impermeability." Diagn Microbiol Infect Dis, 1999 Oct, 35(2), 143 - 51 United States geographic bacteria susceptibility patterns . 1997 ASCP Susceptibility Testing Group; Emerging ciprofloxacin-resistant Pseudomonas aeruginosa; Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine, Florida 33136, USAPURPOSE: To report a clinical series of ciprofloxacin-resistant ocular isolates of Pseudomonas aeruginosa from a tertiary care ophthalmic center . METHODS: Review of in vitro sensitivities of all ocular isolates of P . aeruginosa be tween July 1991 and September 1998 . In vitro resistance was defined as a minimum inhibitory concentration of 4 or more microg per ml . RESULTS: Nine of 423 ocular isolates of P . aeruginosa showed in vitro resistance to ciprofloxacin . From 1991 to 1994, 0.44% (1/227) of ocular isolates were resistant to ciprofloxacin, whereas from 1995 to 1998, 4.1% (8/ 196) of ocular isolates showed in vitro resistance (P = .014) . CONCLUSIONS: Ciprofloxacin-resistant P . aeruginosa has been identified in recent clinical ocular specimens . Ciprofloxacin resistance among ocular isolates of P . aeruginosa is a local and worldwide concern. Toxicology, 1999 Nov 5, 138(2), 103 - 26 Pathophysiological mechanisms of TNF during intoxication with natural or man-made toxins; Schumann J et al.; Intoxication with different natural toxins or man-made toxicants has been associated with the induction of tumor necrosis factor alpha (TNF) . These include endotoxin, superantigens, Pseudomonas aeruginosa exotoxin A, bacterial DNA, T cell stimulatory agents such as agonistic anti-CD3 mAbs or concanavalin A, alpha-amanitin, paracetamol, ethanol, carbon tetrachloride, dioxin, and dimethylnitrosamine . In this paper we compile and discuss the current knowledge on the pathophysiological role of TNF during intoxication with all mentioned toxins and toxicants . A possible role of gut-derived endotoxin in several TNF-dependent toxic events has been considered . The development of pharmaceuticals that selectively interfere with the detrimental pathways induced by TNF during intoxication with bacteria, viruses, drugs, or other chemicals requires detailed knowledge of the signaling pathways originating from the two TNF receptors (TNFR1 and TNFR2) . Major characteristics of these signaling pathways are described and put together. Mikrobiologiia, 1999 Jul-Aug, 68(4), 485 - 90 {Effect of carbon, nitrogen and phosphorus nutrition on the R, S, and M dissociants of Pseudomonas aeruginosa in mixed cultures}; Maksimov VN et al.; The effect of glucose, nitrate, and phosphate on the stationary-phase growth characteristics of R, S, and M dissociants of the hydrocarbon-oxidizing strain P . aeruginosa K-2 was studied . The optimal concentrations of glucose and phosphate providing for at least 90% of the maximal culture density were found to be 2-7% glucose and 0.02-0.12% phosphate . The main factor that determined the proportion of dissociants in bacterial populations was the initial concentration of phosphate . The fraction of R dissociant in populations increased linearly with the concentration of glucose and varied nonlinearly with the concentration of phosphate in the growth medium . The fraction of M dissociant depended solely on the concentration of phosphate in a manner inverse to that typical of R dissociant . In glucose-deficient media containing sufficient amounts of phosphorus, S dissociant prevailed over R dissociant. Genetika, 1999 Sep, 35(9), 1182 - 90 {Natural interspecific hybrids of transposable phages of Pseudomonas aeruginosa}; Mit'kina LN et al.; Bacterial viruses of Pseudomonas aeruginosa assigned to two groups, D3112 and B3, recombine with very low frequencies . Previous study of the genome structure of intergroup hybrids suggested the incompatibility of some genetic modules of these bacteriophages . In this work, several natural hybrid transposable phages that had the genomes largely consisting of modules of phages from group D3112 and B3, were described . The discovery of these phages suggests the continuous genetic exchange in nature of these viruses belonging to different species . This model is considered as promising from the viewpoint of monitoring virus evolution. Proc Natl Acad Sci U S A, 1999 Nov 23, 96(24), 13904 - 9 Identification of genes controlled by quorum sensing in Pseudomonas aeruginosa; Whiteley M et al.; Bacteria communicate with each other to coordinate expression of specific genes in a cell density-dependent fashion, a phenomenon called quorum sensing and response . Although we know that quorum sensing via acyl-homoserine lactone (HSL) signals controls expression of several virulence genes in the human pathogen Pseudomonas aeruginosa, the number and types of genes controlled by quorum sensing have not been studied systematically . We have constructed a library of random insertions in the chromosome of a P . aeruginosa acyl-HSL synthesis mutant by using a transposon containing a promoterless lacZ . This library was screened for acyl-HSL induction of lacZ . Thirty-nine quorum sensing-regulated genes were identified . The genes were organized into classes depending on the pattern of regulation . About half of the genes appear to be in seven operons, some seem organized in large patches on the genome . Many of the quorum sensing-regulated genes code for putative virulence factors or production of secondary metabolites . Many of the genes identified showed a high level of induction by acyl-HSL signaling. Singapore Med J, 1999 Aug, 40(8), 508 - 12 Hospital acquired pneumonia in the medical intensive care unit--a prospective study; Stebbings AE et al.; AIM OF STUDY: The aim of the study was to define the prevalence, risk factors, spectrum of organisms and sensitivity patterns, and the outcome in patients with severe hospital acquired pneumonia (HAP) in the Medical Intensive Care Unit (SCU) in a hospital in Singapore . METHOD: Consecutive patients admitted to the MICU over a 6-month period were studied and assessed daily to determine whether patients had developed HAP based on defined clinical criteria . Sputum or endotracheal aspirate was obtained and results recorded from each patient on admission and every subsequent three days throughout the stay in the MICU . Mortality during hospital stay was the main outcome measure recorded . RESULTS: A total of 136 patients (150 admissions) were studied; 24 patients were identified as having HAP . The prevalence of HAP was 17% {both ventilator-associated pneumonia (VAP) and pneumonia acquired from the ward (WAP)} . Cerebral disease was the main risk factor for VAP (OR 4.94, 95% CI 1.33-18.4) . The spectrum of organisms which caused HAP were polymicrobial, Klebsiella pneumoniae, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus and coagulase negative Staphylococcus . The mortality of patients with VAP and WAP were 72.7% and 76.9% respectively . CONCLUSION: This study concludes that HAP in the MICU is common with a high mortality . The spectrum of organisms was comparable to previous studies. J Bacteriol, 1999 Dec, 181(23), 7401 - 4 Negative control of flagellum synthesis in Pseudomonas aeruginosa is modulated by the alternative sigma factor AlgT (AlgU); Garrett ES et al.; Many respiratory isolates of Pseudomonas aeruginosa from cystic fibrosis patients are mucoid (alginate producing) yet lack flagella . It was hypothesized that an alginate regulator inhibits flagellar gene expression . Mutations in algB, algR, and algT resulted in nonmucoid derivatives, yet algT mutants expressed flagella . AlgT-dependent control of flagellum synthesis occurred through inhibition of fliC but not rpoN transcription. J Bacteriol, 1999 Dec, 181(23), 7398 - 400 Chromate efflux by means of the ChrA chromate resistance protein from Pseudomonas aeruginosa; Alvarez AH et al.; Everted membrane vesicles of Pseudomonas aeruginosa PAO1 harboring plasmid pCRO616, expressing the ChrA chromate resistance protein, accumulated four times more (51)CrO(4)(2-) than vesicles from plasmidless cells, indicating that a chromate efflux system functions in the resistant strain . Chromate uptake showed saturation kinetics with an apparent K(m) of 0.12 mM chromate and a V(max) of 0 . 5 nmol of chromate/min per mg of protein . Uptake of chromate by vesicles was dependent on NADH oxidation and was abolished by energy inhibitors and by the chromate analog sulfate . The mechanism of resistance to chromate determined by ChrA appears to be based on the active efflux of chromate driven by the membrane potential. J Bacteriol, 1999 Dec, 181(23), 7221 - 7 Cloning and analysis of the capsid morphogenesis genes of Pseudomonas aeruginosa bacteriophage D3: another example of protein chain mail? Gilakjan ZA, Kropinski AM. The terminal DNA restriction fragments (PstI-D and -B) of Pseudomonas aeruginosa bacteriophage D3 were ligated, cloned, and sequenced . Of the nine open reading frames in this 8.3-kb fragment, four were identified as encoding large-subunit terminase, portal, ClpP protease, and major head proteins . The portal and capsid proteins showed significant homology with proteins of the lambdoid coliphage HK97 . Phage D3 was purified by CsCl equilibrium gradient centrifugation (rho = 1.533 g/ml), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed six proteins with molecular masses of 186, 91, 79, 70, 45, and 32 kDa . The pattern was unusual, since a major band corresponding to the expected head protein (43 kDa) was missing and a significant amount of the protein was retained in the stacking gel . The amino terminus of the 186-kDa protein was sequenced, revealing that the D3 head is composed of cross-linked 31-kDa protein subunits, resulting from the proteolysis of the 43-kDa precursor . This is identical to the situation observed with coliphage HK97. J Bacteriol, 1999 Dec, 181(23), 7176 - 84 AlgT (sigma22) controls alginate production and tolerance to environmental stress in Pseudomonas syringae; Keith LM et al.; Pseudomonas aeruginosa and the phytopathogen P . syringae produce the exopolysaccharide alginate, which is a copolymer of D-mannuronic and L-guluronic acids . One of the key regulatory genes controlling alginate biosynthesis in P . aeruginosa is algT, which encodes the alternate sigma factor, sigma(22) . In the present study, the algT gene product from P . syringae pv . syringae showed 90% amino acid identity with its P . aeruginosa counterpart, and sequence analysis of the region flanking algT in P . syringae revealed the presence of nadB, mucA, and mucB in an arrangement virtually identical to that of P . aeruginosa . An algT mutant of P . syringae was defective in alginate production but could be complemented with wild-type algT from P . syringae or P . aeruginosa when expressed in trans . The algT mutant also displayed increased sensitivity to heat, paraquat, and hydrogen peroxide (H(2)O(2)); the latter two compounds are known to generate reactive oxygen intermediates . Signals for activation of algT gene expression in P . syringae were investigated with an algT::uidA transcriptional fusion . Like that in P . aeruginosa, algT transcription in P . syringae was activated by heat shock . However, algT expression in P . syringae was also stimulated by osmotic stress and by exposure to paraquat, H(2)O(2), and copper sulfate . The latter two compounds are frequently encountered during colonization of plant tissue and may be unique signals for algT activation in P . syringae. J Paediatr Child Health, 1999 Oct, 35(5), 505 - 6 Ecthyma gangrenosum as a very early herald of acute lymphoblastic leukaemia; Pouryousefi A et al.; Ecthyma gangrenosum is a manifestation of cutaneous infection by Pseudomonas aeruginosa . The lesion may be associated with immunocompromise, in particular neutropenia . We present a case of ecthyma gangrenosum in a previously healthy child who 3 months later developed acute lymphoblastic leukaemia; we use this to illustrate the lack of information on the growth rate of malignant and premalignant leukaemic cells in children. Gene, 1999 Oct 1, 238(2), 417 - 25 Identification of a gene cluster, czr, involved in cadmium and zinc resistance in Pseudomonas aeruginosa; Hassan MT et al.; Pseudomonas aeruginosa CMG103 was isolated from a metal-polluted river in Pakistan and displayed a high level of Zn and Cd resistance . An omega-Km transposon mutant of strain CMG103, which showed a substantial decrease in resistance to Zn and Cd, was obtained . A 12.8 kb region determining Zn and Cd resistance in strain CM103 was cloned by complementing the mutant strain, and its nt sequence was determined . Five genes, czrSRCBA, involved in Zn and Cd resistance, were identified . The predicted gene products of czrCBA show a significant similarity with the proteins encoded by the plasmid borne metal resistant determinants czc, cnr and ncc of Ralstonia strains, which determine a chemiosmotic cation-antiporter efflux system . The predicted CzrS and CzrR proteins show a significant similarity to the sensor and regulatory protein, respectively, of two component regulatory systems, such as CopS/CopR and PcoS/PcoR involved in the regulation of plasmid-borne Cu-resistant determinants, and CzcS/CzcR involved in the regulation of czc . The cloned czr region contained downstream of czrCBA additional ORFs whose predicted gene products are similar to proteins involved in catabolism of aromatic compounds . DNA-DNA hybridization indicated strong conservation of czr in other environmental P . aeruginosa isolates and in the P . aeruginosa type strain PAO1, a clinical isolate . This was confirmed by a comparison of the sequence of the CMG103 czr region with the currently available genome sequence of strain PAO1 . A high sequence identity (till 99% at the nt level) and organizatory conservation of the czr region of CMG103 was found in PAO1 as well regarding coding sequences as intervening sequences between ORFs . The czr locus was localized between coordinates 2400 and 2550 kb on the physical map of the chromosome of PAO1. Appl Microbiol Biotechnol, 1999 Oct, 52(4), 524 - 33 Recombinant protein composed of Pseudomonas exotoxin A, outer membrane proteins I and F as vaccine against P . aeruginosa infection; Chen TY et al.; We have constructed a chimeric protein composed of the receptor binding and membrane translocation domains of Pseudomonas exotoxin A (PE) with the outer membrane proteins I and F, together designated as PEIF . The potential of PEIF as a vaccine against Pseudomonas infection was evaluated in BALB/c mice and New Zealand white rabbits . We examined titers of anti-PE and anti-OprF antibodies, and the ability both to neutralize PE cytotoxicity and to increase opsonophagocytic uptake of Pseudomonas aeruginosa strain PAO1, serogroups 2 and 6 . The results showed that PEIF can induce antibodies not only to neutralize the PE cytotoxicity but also to promote the uptake of various strains of P . aeruginosa by murine peritoneal macrophages . In a burned mouse model, PEIF afforded significant protection against infection by the homologous P . aeruginosa strain PAO1, heterologous serogroup 2, and the PE hyperproducing strain PA103 . These observations thus indicate that PEIF may be used as a novel vaccine against P . aeruginosa infection. Eur J Biochem, 1999 Dec, 266(2), 616 - 23 Purification, cDNA cloning and modification of a defensin from the coconut rhinoceros beetle, Oryctes rhinoceros; Ishibashi J et al.; A novel member of the insect defensins, a family of antibacterial peptides, was purified from larvae of the coconut rhinoceros beetle, Oryctes rhinoceros, immunized with Escherichia coli . A full-size cDNA was cloned by combining reverse-transcription PCR (RT-PCR), and 5'- and 3'-rapid amplification of cDNA ends (RACE) . Analysis of the O . rhinoceros defensin gene expression showed it to be expressed in the fat body and hemocyte, midgut and Malpighian tubules . O . rhinoceros defensin showed strong antibacterial activity against Staphylococcus aureus . A 9-mer peptide amidated at its C-terminus, AHCLAICRK-NH2 (Ala22-Lys30-NH2), was synthesized based on the deduced amino-acid sequence, assumed to be an active site sequence by analogy with the sequence of a defensin isolated from larvae of the beetle Allomyrina dichotoma . This peptide showed antibacterial activity against S . aureus, methicillin-resistant S . aureus, E . coli and Pseudomonas aeruginosa . We further modified this oligopeptide and synthesized five 9-mer peptides, ALRLAIRKR-NH2, ALLLAIRKR-NH2, AWLLAIRKR-NH2, ALYLAIRKR-NH2 and ALWLAIRKR-NH2 . These oligopeptides showed strong antibacterial activity against Gram-negative and Gram-positive bacteria . The antibacterial effect of Ala22-Lys30-NH2 analogues was due to its interaction with bacterial membranes, judging from the leakage of liposome-entrapped glucose . These Ala22-Lys30-NH2 analogues did not show haemolytic activity and did not inhibit the growth of murine fibroblast cells or macrophages, except for AWLLAIRKR-NH2. Science, 1999 Nov 19, 286(5444), 1561 - 5 Specific lipopolysaccharide found in cystic fibrosis airway Pseudomonas aeruginosa; Ernst RK et al.; Cystic fibrosis (CF) patients develop chronic airway infections with Pseudomonas aeruginosa (PA) . Pseudomonas aeruginosa synthesized lipopolysaccharide (LPS) with a variety of penta- and hexa-acylated lipid A structures under different environmental conditions . CF patient PA synthesized LPS with specific lipid A structures indicating unique recognition of the CF airway environment . CF-specific lipid A forms containing palmitate and aminoarabinose were associated with resistance to cationic antimicrobial peptides and increased inflammatory responses, indicating that they are likely to be involved in airway disease. Am J Health Syst Pharm, 1999 Nov 1, 56(21), 2217 - 23 Influence of fluoroquinolone purchasing patterns on antimicrobial expenditures and Pseudomonas aeruginosa susceptibility; Rifenburg RP et al.; The influence of using ofloxacin in place of ciprofloxacin on hospital fluoroquinolone expenditures, total antimicrobial expenditures, and susceptibility of Pseudomonas aeruginosa to fluoroquinolones was studied . Hospitals with fluoroquinolone expenditures of at least $1 per occupied bed per year were administered annual surveys covering the years 1993 through 1996 . The two most recent consecutive years of data were compared among hospitals that used ciprofloxacin as their primary fluoroquinolone during both years (group 1), hospitals whose ofloxacin purchases increased from accounting for < or =25% of total fluoroquinolone expenditures during year 1 to accounting for >25% during year 2 (group 2), and hospitals whose ofloxacin purchases accounted for at least 25% of total fluoroquinolone expenditures for both years (group 3) . A total of 109 hospitals were included in the study . Most hospitals spent more on fluoroquinolones and total antimicrobials in year 2 than year 1 . Group 3 hospitals had a significant increase in expenditures for fluoroquinolones and non-fluoroquinolone antipseudomonal antimicrobials . Group 2 hospitals did not realize antimicrobial cost savings and had higher rates of Pseudomonas aeruginosa resistance than hospitals that used ciprofloxacin . Whether a hospital changed its pattern of ciprofloxacin and ofloxacin purchasing was not significantly associated with expenditures for fluoroquinolones, nonfluoroquinolone antimicrobial agents, or all antimicrobials . Susceptibility of P . aeruginosa to ciprofloxacin was lower in hospitals with greater proportions of ofloxacin use . Individual hospital, ciprofloxacin expenditures, and study year were found to be predictive of P . aeruginosa susceptibility to ciprofloxacin among all pooled hospitals. Burns, 1999 Nov, 25(7), 611 - 6 Pseudomonas aeruginosa septicaemia in burns; Gang RK et al.; Out of 1415 patients treated as inpatients at Al-Babtain Center for Burns and Plastic Surgery, Ibn Sina Hospital, Kuwait spanning over a period of 6 years from June 1992 to June 1998, 102 developed clinically and microbiologically proven septicaemia . Only 15 out of them had either single or multiple episodes of septicaemia due to Pseudomonas aeruginosa and were studied during their stay in the hospital . Five of them were males and 10 females, with a mean age of 26 years (range 3-51 years) and mean total body surface area of burns (TBSA) of 66% (range 25-90%) . All of them had flame burns and resuscitation was found to be difficult in eight patients either due to delayed hospitalization or accompanied inhalation injury . Seven patients were intubated, four due to inhalation injury and three for septicaemic complications . Among the 15 patients under study, a total of 36 septicaemic episodes were detected of which 21 were due to P . aeruginosa . This organism was found in the first episodes in nine patients, in second episodes in six, in third episodes in three and fourth, fifth and sixth episodes in one patient, each at a variable postburn day . Ten patients had 38 sessions of excision and skin grafting, six of them survived . Nine of the 15 patients under study died due to septicaemia, but only six of them had P . aeruginosa as the last isolate . Except for one, all patients had > 40% TBSA burn, two had difficult resuscitation and four were intubated . The day of death varied between 3 to 52 days postburn (mean 19 days) . This study showed that females with flame burns are susceptible to P . aeruginosa septicaemia . Difficult resuscitation and intubation also proved to be important risk factors . Septicaemia could occur quite early in the postburn days and the mortality due to this organism was quite high . Early excision and grafting with other effective management may result in a better outcome. Biochim Biophys Acta, 1999 Nov 16, 1435(1-2), 71 - 83 Phospholipids stabilize the secondary structure of the sodium-coupled branched-chain amino acid carrier of Pseudomonas aeruginosa; Uratani Y et al.; For functional reconstitution of bacterial cotransporters (carriers or permeases) including the sodium-coupled branched-chain amino acid carrier (LIV-II carrier) of Pseudomonas aeruginosa, the presence of phospholipid is required through the process of solubilization and purification of the transporters from the bacterial membranes, suggesting the possibility that phospholipid may stabilize the structure of the cotransporter proteins to be in a functional form . In this study, this possibility was examined by studying the effect of denaturant on the secondary structure of the LIV-II carrier purified in the absence and presence of phospholipid using circular dichroism (CD) spectroscopy . CD spectra of the purified LIV-II carrier solubilized in n-octyl-beta-D-glucopyranoside (OG), OG/dioleoylphosphatidylethanolamine (DOPE)/dioleoylphosphatidylglycerol (DOPG) mixture, and dispersed into DOPE/DOPG small unilamellar vesicles were measured in the absence of denaturant . The three spectra were very similar and had a trough at 222 nm with mean residue molar ellipticity of -23000 deg.cm(2)/dmol and a shoulder at 208 nm . CD spectral analyses with three different methods (S.W . Provencher, J . Glockner, Estimation of globular protein secondary structure from circular dichroism, Biochemistry 20 (1981) 33-37; J.Y . Yang, C.-S.C . Wu, H.Z . Martinez, Calculation of protein conformation from circular dichroism, Methods Enzymol . 130 (1986) 208-269; N . Sreerama, R.W . Woody, A self-consistent method for the analysis of protein secondary structure from circular dichroism, Anal . Biochem . 209 (1993) 32-44) revealed that the LIV-II carrier solubilized in OG/DOPE/DOPG mixture contained 69-75% alpha-helix and 0-9% beta-sheet . Addition of 6 M guanidine hydrochloride decreased 48% of the amplitude at 222 nm of the CD spectrum of the carrier solubilized in OG alone and 9-14% of the CD amplitude of the carrier solubilized in OG/DOPE/DOPG or OG/dioleoylphosphatidylcholine mixture and dispersed in liposomes composed of DOPE/DOPG . These results show that the ordered secondary structure of the LIV-II carrier is partially unfolded in OG without phospholipid by denaturant but is greatly stabilized with phospholipids with oleoyl chains independently of their polar head group composition and suggest that the alpha-helical structure of the carrier is mainly embedded in the lipid environment. J Immunol, 1999 Nov 15, 163(10), 5505 - 11 Role of protein kinase C-alpha in the control of infection by intracellular pathogens in macrophages; St-Denis A et al.; The protein kinase C (PKC) family regulates macrophage function involved in host defense against infection . In this study, we investigated the role of macrophage PKC-alpha in the uptake and subsequent fate of Leishmania donovani promastigotes and Legionella pneumophila infections . To this end, we used clones of the murine macrophage cell line RAW 264.7 overexpressing a dominant-negative (DN) mutant of PKC-alpha . While phagocytosis of L . donovani promastigotes was not affected by DN PKC-alpha overexpression, their intracellular survival was enhanced by 10- to 20-fold at 48 h postinfection . Intracellular survival of a L . donovani mutant defective in lipophosphoglycan repeating units synthesis, which normally is rapidly degraded in phagolysosomes, was enhanced by 100-fold at 48 h postinfection . However, IFN-gamma-induced leishmanicidal activity was not affected by DN PKC-alpha overexpression . Similar to macrophages from genetically resistant C57BL/6 mice, control RAW 264.7 cells were not permissive for the intracellular replication of Legionella pneumophila . In contrast, DN PKC-alpha-overexpressing RAW 264.7 clones were phenotypically similar to macrophages from genetically susceptible A/J mice, as they allowed intracellular replication of L . pneumophila . Permissiveness to L . pneumophila was not the consequence of a general defect in the microbicidal capacities because killing of a temperature-sensitive mutant of Pseudomonas aeruginosa was normal in DN PKC-alpha-overexpressing RAW 264.7 clones . Collectively, these results support a role for PKC-alpha in the regulation of innate macrophage functions involved in the control of infection by intracellular parasites. Mol Microbiol, 1999 Nov, 34(3), 399 - 413 The response of Pseudomonas aeruginosa to iron: genetics, biochemistry and virulence; Vasil ML et al.; During the past decade significant progress has been made towards identifying some of the schemes that Pseudomonas aeruginosa uses to obtain iron and towards cataloguing and characterizing many of the genes and gene products that are likely to play a role in these processes . This review will largely recount what we have learned in the past few years about how P . aeruginosa regulates its acquisition, intake and, to some extent, trafficking of iron, and the role of iron acquisition systems in the virulence of this remarkable opportunistic pathogen . More specifically, the genetics, biochemistry and biology of an essential regulator (Ferric uptake regulator - Fur) and a Fur-regulated alternative sigma factor (PvdS), which are central to these processes, will be discussed . These regulatory proteins directly or indirectly regulate a substantial number of other genes encoding proteins with remarkably diverse functions . These genes include: (i) other regulatory genes, (ii) genes involved in basic metabolic processes (e.g . Krebs cycle), (iii) genes required to survive oxidative stress (e.g . superoxide dismutase), (iv) genes necessary for scavenging iron (e.g . siderophores and their cognate receptors) or genes that contribute to the virulence (e.g . exotoxin A) of this opportunistic pathogen . Despite this recent expansion of knowledge about the response of P . aeruginosa to iron, many significant biological issues surrounding iron acquisition still need to be addressed . Virtually nothing is known about which of the distinct iron acquisition mechanisms P . aeruginosa brings to bear on these questions outside the laboratory, whether it be in soil, in a pipeline, on plants or in the lungs of cystic fibrosis patients. Mol Microbiol, 1999 Oct, 34(2), 317 - 26 LipC, a second lipase of Pseudomonas aeruginosa, is LipB and Xcp dependent and is transcriptionally regulated by pilus biogenesis components; Martinez A et al.; We have isolated cosmids that complement a Pseudomonas aeruginosa export-impaired mutant by increasing growth on lipid agar, a medium that requires lipase expression and export . These cosmids encode a previously unidentified lipase, LipC, which has high homology to the P . aeruginosa lipA gene product . Like LipA, LipC activity requires the chaperone activity of the lipB gene product and a functional xcp gene cluster for export . However, expression of LipC is barely detectable in a wild-type background . Transposon insertions that increase lipC promoter activity have been obtained that inactivate two pilus biogenesis genes, pilX and pilY1 . This suggests that these proteins either directly or indirectly repress the expression of LipC and may be involved in transducing an extracellular signal that regulates this lipase. J Bacteriol, 1999 Nov, 181(22), 6865 - 75 Thickness and elasticity of gram-negative murein sacculi measured by atomic force microscopy; Yao X et al.; Atomic force microscopy was used to measure the thickness of air-dried, collapsed murein sacculi from Escherichia coli K-12 and Pseudomonas aeruginosa PAO1 . Air-dried sacculi from E . coli had a thickness of 3.0 nm, whereas those from P . aeruginosa were 1.5 nm thick . When rehydrated, the sacculi of both bacteria swelled to double their anhydrous thickness . Computer simulation of a section of a model single-layer peptidoglycan network in an aqueous solution with a Debye shielding length of 0.3 nm gave a mass distribution full width at half height of 2.4 nm, in essential agreement with these results . When E . coli sacculi were suspended over a narrow groove that had been etched into a silicon surface and the tip of the atomic force microscope used to depress and stretch the peptidoglycan, an elastic modulus of 2.5 x 10(7) N/m(2) was determined for hydrated sacculi; they were perfectly elastic, springing back to their original position when the tip was removed . Dried sacculi were more rigid with a modulus of 3 x 10(8) to 4 x 10(8) N/m(2) and at times could be broken by the atomic force microscope tip . Sacculi aligned over the groove with their long axis at right angles to the channel axis were more deformable than those with their long axis parallel to the groove axis, as would be expected if the peptidoglycan strands in the sacculus were oriented at right angles to the long cell axis of this gram-negative rod . Polar caps were not found to be more rigid structures but collapsed to the same thickness as the cylindrical portions of the sacculi . The elasticity of intact E . coli sacculi is such that, if the peptidoglycan strands are aligned in unison, the interstrand spacing should increase by 12% with every 1 atm increase in (turgor) pressure . Assuming an unstressed hydrated interstrand spacing of 1.3 nm (R . E . Burge, A . G . Fowler, and D . A . Reaveley, J . Mol . Biol . 117:927-953, 1977) and an internal turgor pressure of 3 to 5 atm (or 304 to 507 kPa) (A . L . Koch, Adv . Microbial Physiol . 24:301-366, 1983), the natural interstrand spacing in cells would be 1.6 to 2.0 nm . Clearly, if large macromolecules of a diameter greater than these spacings are secreted through this layer, the local ordering of the peptidoglycan must somehow be disrupted. Br J Pharmacol, 1999 Oct, 128(4), 845 - 8 The Pseudomonas aeruginosa quorum-sensing signal molecule, N-(3-oxododecanoyl)-L-homoserine lactone, inhibits porcine arterial smooth muscle contraction; Lawrence RN et al.; The Pseudomonas aeruginosa quorum sensing molecule N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) has been shown to suppress cytokine production in macrophages . We have examined the effect of OdDHL and related compounds on constrictor tone of porcine blood vessels . OdDHL (1-30 microM) caused a concentration-dependent inhibition of U46619-induced contractions of the coronary artery through a largely endothelium-independent mechanism, but was markedly less effective in the pulmonary artery . Quantitively similar effects to those produced by OdDHL were observed with N-(3-oxododecanoyl)-L-homocysteine thiolactone, a thiolactone derivative, while N-3-oxododecanamide, a lactone-free acyl analogue, possessed 1/3rd the potency as a vasorelaxant . Neither N-butanoyl-L-homoserine lactone nor L-homoserine lactone (up to 30 microM) were active . Our findings indicate that OdDHL inhibits vasoconstrictor tone of both pulmonary and coronary blood vessels from the pig . The vasorelaxant action of OdDHL appears to be primarily determined by the N-acyl chain length, with a minor contribution by the homoserine lactone moiety. FEMS Microbiol Lett, 1999 Nov 15, 180(2), 311 - 6 In vitro transcription analysis of rpoD in Pseudomonas aeruginosa PAO1; Aramaki H et al.; The rpoD gene encoding the principal sigma factor (sigma(70)) of Pseudomonas aeruginosa is transcribed from two promoters, P(C) and P(HS) . The sequence of P(C) is similar to the Escherichia coli sigma(70) consensus promoter sequence and that of P(HS) is similar to the E . coli sigma(H) consensus promoter sequence . Synthesis of rpoD mRNA from P(C) is constitutive under both steady-state and heat-shock growth conditions, while that of P(HS) is transiently induced upon heat-shock . To gain a better understanding of the regulation of rpoD expression, we examined in vitro transcription of rpoD using two RNA polymerases (Esigma(70) and Esigma(H), containing sigma(70) and sigma(H), respectively) purified from P . aeruginosa . DNase I footprinting analysis showed specific bindings of Esigma(70) and Esigma(H) to P(C) and P(HS) promoter regions, respectively . In the in vitro runoff transcription assay, Esigma(H) transcribed the template from P(HS) both at 30 degrees C and 42 degrees C but not from P(C) . However, Esigma(70) transcribed rpoD not only from P(C) both at 30 degrees C and 42 degrees C but also from P(HS) at 42 degrees C. FEMS Microbiol Lett, 1999 Nov 15, 180(2), 305 - 10 Characteristics of sheep-rumen isolates of Pseudomonas aeruginosa inhibitory to the growth of Escherichia coli O157; Duncan SH et al.; Screening facultative sheep-rumen bacteria which inhibit growth of Escherichia coli produced 11 strains of Pseudomonas aeruginosa . The isolates showed three different pulsed-field gel electrophoresis patterns and strains from different sheep produced pyocins that varied in strain specificity . Representative strains were resistant to ampicillin, methicillin, erythromycin, fusidic acid and augmentin, but not to tetracycline or nalidixic acid . Tested strains attached in large numbers to cultured rumen epithelial cells, potentially providing a means of survival in this ecosystem. Am J Respir Crit Care Med, 1999 Nov, 160(5 Pt 1), 1711 - 6 Dry powder versus intravenous and nebulized gentamicin in cystic fibrosis and bronchiectasis . A pilot study; Crowther Labiris NR et al.; Aminoglycosides are a mainstay of therapy for patients with cystic fibrosis (CF) or non-CF bronchiectasis who are infected with Pseudomonas aeruginosa (Psa) . Traditionally, aerosolized antibiotics are delivered by liquid nebulization . The objective of this study was to determine whether a gentamicin dry powder inhaler (DPI) is as microbiologically active and potentially safe as gentamicin inhaled via a small-volume nebulizer (SVN) or given intravenously . The study was done according to a randomized, single-dose, and triple crossover protocol . Ten patients with CF or non-CF bronchiectasis and chronically infected with Psa were recruited . Patients received a single dose of either gentamicin 160 mg via DPI or SVN, or gentamicin at 5 mg/kg by intravenous infusion . In seven of the 10 patients, the minimum inhibitory concentration (MIC) was achieved in sputum after DPI and SVN, with mean (95% confidence interval) gentamicin concentrations at 2 h after administration of 13.1 microgram/g sputum (range: 2.2 to 23.9 microgram/g) and 97.2 microgram/g sputum (range: 0.3 to 194.2 microgram/g), respectively, whereas gentamicin levels in the sputum after intravenous administration failed to reach the MIC . Gentamicin given by DPI and SVN significantly decreased the sputum Psa density (p < 0.05), by almost one order of magnitude . No significant decline in bacterial counts was observed after intravenous gentamicin . When gentamicin was inhaled,