Medicine (Baltimore), 2004 May, 83(3), 139 - 48 Sternoclavicular septic arthritis: review of 180 cases; Ross JJ et al.; We review 170 previously reported cases of sternoclavicular septic arthritis, and report 10 new cases . The mean age of patients was 45 years; 73% were male . Patients presented with chest pain (78%) and shoulder pain (24%) after a median duration of symptoms of 14 days . Only 65% were febrile . Bacteremia was present in 62% . Common risk factors included intravenous drug use (21%), distant site of infection (15%), diabetes mellitus (13%), trauma (12%), and infected central venous line (9%) . No risk factor was found in 23% . Serious complications such as osteomyelitis (55%), chest wall abscess or phlegmon (25%), and mediastinitis (13%) were common . Staphylococcus aureus was responsible for 49% of cases, and is now the major cause of sternoclavicular septic arthritis in intravenous drug users . Pseudomonas aeruginosa infection in injection drug users declined dramatically with the end of an epidemic of pentazocine abuse in the 1980s . Sternoclavicular septic arthritis accounts for 1% of septic arthritis in the general population, but 17% in intravenous drug users, for unclear reasons . Bacteria may enter the sternoclavicular joint from the adjacent valves of the subclavian vein after injection of contaminated drugs into the upper extremity, or the joint may become infected after attempted drug injection between the heads of the sternocleidomastoid muscle . Computed tomography or magnetic resonance imaging should be obtained routinely to assess for the presence of chest wall phlegmon, retrosternal abscess, or mediastinitis . If present, en-bloc resection of the sternoclavicular joint is indicated, possibly with ipsilateral pectoralis major muscle flap . Empiric antibiotic therapy may need to cover methicillin-resistant Staphylococcus aureus (MRSA). J Biol Chem, 2004 Jun 18, 279(25), 25939 - 42 Epub 2004 Apr 26. Crystal structure of the membrane fusion protein, MexA, of the multidrug transporter in Pseudomonas aeruginosa; Akama H et al.; The MexAB-OprM efflux pump of Pseudomonas aeruginosa is central to multidrug resistance of this organism, which infects immunocompromised hospital patients . The MexA, MexB, and OprM subunits were assumed to function as the membrane fusion protein, the body of the transporter, and the outer membrane channel protein, respectively . For better understanding of this important xenobiotic transporter, we show the x-ray crystallographic structure of MexA at a resolution of 2.40 A . The global MexA structure showed unforeseen new features with a spiral assembly of six and seven protomers that were joined together at one end by a pseudo 2-fold image . The protomer showed a new protein structure with a tandem arrangement consisting of at least three domains and presumably one more . The rod domain had a long hairpin of twisted coiled-coil that extended to one end . The second domain adjacent to the rod alpha-helical domain was globular and constructed by a cluster of eight short beta-sheets . The third domain located distal to the alpha-helical rod was globular and composed of seven short beta-sheets and one short alpha-helix . The 13-mer was shaped like a woven rattan cylinder with a large internal tubular space and widely opened flared ends . The 6-mer and 7-mer had a funnel-like structure consisting of a tubular rod at one side and a widely opened flared funnel top at the other side . Based on these results, we constructed a model of the MexAB-OprM pump assembly . The three pairs of MexA dimers interacted with the periplasmic alpha-barrel domain of OprM via the alpha-helical hairpin, the second domain interacted with both MexB and OprM at their contact site, and the third and disordered domains probably interacted with the distal domain of MexB . In this fashion, the MexA subunit connected MexB and OprM, indicating that MexA is the membrane bridge protein. J Infect Dis, 2004 May 1, 189(9), 1590 - 7 Epub 2004 Apr 16. Relationship between fluoroquinolone area under the curve: minimum inhibitory concentration ratio and the probability of eradication of the infecting pathogen, in patients with nosocomial pneumonia; Drusano GL et al.; Our objective was to prospectively determine the factors influencing the probability of a good microbiological or clinical outcome in patients with nosocomial pneumonia treated with a fluoroquinolone . Levofloxacin was administered as an infusion of 500 mg/h for 1.5 h (total dose, 750 mg) . For patients with Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus, a second drug was added (ceftazidime or piperacillin/tazobactam for P . aeruginosa and vancomycin for methicillin-resistant S . aureus) . Population pharmacokinetic studies of 58 patients demonstrated that this population handled the drug differently from populations of volunteers . Multivariate logistic regression analysis (n=47 patients) demonstrated that only the age of the patient and the achievement of an area under the curve: minimum inhibitory concentration ratio of > or =87 had a significant effect on eradication of the pathogen (P<.001) . Achieving the breakpoint made the patient 4 times more likely to achieve eradication . The effect was greatest in patients > or =67 years old. Photochem Photobiol, 2004 Mar, 79(3), 297 - 302 Effect of monovalent and divalent cations on the photoinactivation of bacteria with meso-substituted cationic porphyrins; Lambrechts SA et al.; It is well established that for successful photoinactivation (PI) of gram-negative bacteria a cationic photosensitizer is required . This requirement suggests a charge-dependent interaction between the photosensitizer and the gram-negative bacterium, which may be influenced by the presence of ions in the suspending medium . The aim of the present study was to investigate the effect of cations Na+ and Ca2+ on the efficacy of the PI of the gram-negative Pseudomonas aeruginosa and the gram-positive Staphylococcus aureus . The bacteria were suspended in buffer containing either meso-tetra(N-methyl-4-pyridyl)-porphyrin or meso-mono-phenyl-tri(N-methyl-4-pyridyl)-porphyrin as photosensitizer and various concentrations of Na+ or Ca2+ . The cell suspensions were exposed to a broadband light dose of 9 J/cm2 . In buffer without added cations, P . aeruginosa and S . aureus were equally sensitive to PI . Addition of cations strongly decreased the sensitivity of both bacteria to PI, with the PI of P . aeruginosa being much more decreased than that of S . aureus, and Ca2+ being more effective than Na+ . The decreased sensitivity was accompanied by a reduced binding of the photosensitizers to the bacteria. Anal Biochem, 2004 May 15, 328(2), 225 - 32 A continuous spectrophotometric assay for Pseudomonas aeruginosa LasA protease (staphylolysin) using a two-stage enzymatic reaction; Kessler E et al.; Pseudomonas aeruginosa LasA protease is a secreted metalloendopeptidase that can lyse Staphylococcus aureus cells by cleaving the pentaglycine bridges of their peptidoglycan . It can also degrade elastin and stimulate shedding of cell-surface proteoglycans, activities implicated in pathogenesis of P . aeruginosa infections . The activity of LasA protease can be assayed spectrophotometrically by following the reduction in turbidity of S . aureus cell suspensions . This assay, however, does not permit kinetic studies and its reproducibility is poor . Here we describe a two-stage enzymatic reaction for the continuous measurement of LasA protease activity using a defined substrate, succinyl-Gly-Gly-Phe-4-nitroanilide, supplemented with Streptomyces griseus aminopeptidase . Cleavage of the Gly-Phe bond by LasA protease is followed by hydrolysis of the product Phe-4-nitroanilide by the aminopeptidase and the rate of release of the chromophore (4-nitroaniline) is measured spectrophotometrically using a 96-well microplate reader . Activity of nanogram amounts of LasA protease could be determined within a few minutes . Furthermore, this assay permitted the determination of Km and kcat values for LasA protease, which were 0.46 mM and 11.8s(-1), respectively . Pseudomonas elastase was also active in the assay . However, it was less effective than LasA protease and its activity was inhibited by phosphoramidon . The assay is highly sensitive and reproducible, providing a convenient tool for further studies of LasA protease function(s) and mechanism of action. Clin Microbiol Infect, 2004 May, 10(5), 431 - 5 Intravenous catheter infections associated with bacteraemia: a 2-year study in a university hospital; Paragioudaki M et al.; The aim of this retrospective study was to assess the incidence and aetiology of central and peripheral venous catheter (C/PVC) infections during a 2-year period (1999-2000) and to determine the susceptibility of isolated microorganisms to various antimicrobial agents . Catheter tips were processed using the semiquantitative method and blood cultures were performed with the BacT/Alert automated system . Antibiotic susceptibilities were performed by disk agar diffusion and MICs were determined by Etest, according to NCCLS standards . During the study period, samples from 1039 C/PVC infections were evaluated, yielding 384 (37.0%) positive cultures . Blood cultures were also available from 274 patients, of which 155 (56.6%) yielded the same microorganism as from the catheter . No bloodstream infections were detected in 104 C/PVC-positive cases . Methicillin-resistant coagulase-negative staphylococci were the most frequent isolates, followed by Gram-negative bacteria, especially Pseudomonas aeruginosa . Resistance to glycopeptides among staphylococci and enterococci was not detected, whereas 60% of Gram-negative bacilli were resistant to beta-lactams. Exp Eye Res, 2004 Jun, 78(6), 1155 - 62 TIMP-1 role in protection against Pseudomonas aeruginosa-induced corneal destruction; Kernacki KA et al.; To establish the role of TIMP-1 in protection against Pseudomonas aeruginosa-induced corneal destruction, corneas of adult 8-week-old (resistant) and aged 12-month-old (susceptible) mice were infected with the bacterium . Corneas were analyzed for TIMP-1 protein by immunocytochemistry and Western blotting . Basement membrane (BM) integrity was assessed by immunostaining for type IV collagen . Additionally, resistant 8-week-old mice were treated systemically with neutralizing TIMP-1 polyclonal antibody (pAb) or pre-immune normal rabbit serum (NRS) . Ocular and BM integrity as well as MMP-9 expression were examined in these mice . A greater amount of TIMP-1 protein was observed in the cornea of 8-week-old mice . In the cornea, the strongest staining was found in the superficial epithelium, but positive staining also was seen in the basal epithelium and stroma . When type IV collagen was analyzed in the BM of both age groups of mice, a distinct staining pattern was observed in only the young adult mice . Treatment of 8-week-old resistant mice with neutralizing TIMP-1 pAb vs NRS increased the amount of MMP-9 in the cornea of TIMP-1 pAb-treated mice and affected the ability of these mice to deposit BM components . These studies suggest that adequate expression of TIMP-1 protects against BM and stromal degradation via multiple processes. Bioorg Med Chem Lett, 2004 May 17, 14(10), 2493 - 7 MexAB-OprM specific efflux pump inhibitors in Pseudomonas aeruginosa . Part 4: Addressing the problem of poor stability due to photoisomerization of an acrylic acid moiety; Nakayama K et al.; Exchange of the ethylene tether in a series of pyridopyrimidine-based MexAB-OprM specific efflux pump inhibitors to an amide bond stabilized the olefin of the acrylic acid moiety, preventing facile photoisomerization to the Z-isomer . Furthermore, the activity was drastically improved in the amide tether variants, providing extremely potent acrylic acid and vinyl tetrazole analogues. Emerg Infect Dis, 2004 Mar, 10(3), 535 - 8 Endemic carbapenem-resistant Pseudomonas aeruginosa with acquired metallo-beta-lactamase determinants in European hospital; Lagatolla C et al.; Acquired metallo-beta-lactamases (MBLs) can confer broad-spectrum beta-lactam resistance (including carbapenems) not reversible by conventional beta-lactamase inhibitors and are emerging resistance determinants of remarkable clinical importance . In 2001, multidrug-resistant Pseudomonas aeruginosa carrying bla(VIM) MBL genes were found to be widespread (approximately 20% of all P . aeruginosa isolates and 70% of the carbapenem-resistant isolates) at Trieste University Hospital . Clonal diversity and heterogeneity of resistance determinants (either bla(VIM-1)-like or bla(VIM-2)-like) were detected among MBL producers . This evidence is the first that acquired MBLs can rapidly emerge and establish a condition of endemicity in certain epidemiologic settings. Am J Physiol Lung Cell Mol Physiol, 2004 Aug, 287(2), L402 - 10 Epub 2004 Apr 23. Effect of lung-protective ventilation on severe Pseudomonas aeruginosa pneumonia and sepsis in rats; Kurahashi K et al.; Pneumonia caused by Pseudomonas aeruginosa carries a high rate of morbidity and mortality . A lung-protective strategy using low tidal volume (V(T)) ventilation for acute lung injury improves patient outcomes . The goal of this study was to determine whether low V(T) ventilation has similar utility in severe P . aeruginosa infection . A cytotoxic P . aeruginosa strain, PA103, was instilled into the left lung of rats anesthetized with pentobarbital . The lung-protective effect of low V(T) (6 ml/kg) with or without high positive end-expiratory pressure (PEEP, 10 or 3 cmH(2)O) was then compared with high V(T) with low PEEP ventilation (V(T) 12 ml/kg, PEEP 3 cmH(2)O) . Severe lung injury and septic shock was induced . Although ventilatory mode had little effect on the involved lung or septic physiology, injury to noninvolved regions was attenuated by low V(T) ventilation as indicated by the wet-to-dry weight ratio (W/D; 6.13 +/- 0.78 vs . 3.78 +/- 0.26, respectively) and confirmed by histopathological examinations . High PEEP did not yield a significant protective effect (W/D, 4.03 +/- 0.32) but, rather, caused overdistension of noninvolved lungs . Bronchoalveolar lavage revealed higher concentrations of TNF-alpha in the fluid of noninvolved lung undergoing high V(T) ventilation compared with those animals receiving low V(T) . We conclude that low V(T) ventilation is protective in noninvolved regions and that the application of high PEEP attenuated the beneficial effects of low V(T) ventilation, at least short term . Furthermore, low V(T) ventilation cannot protect the involved lung, and high PEEP did not significantly alter lung injury over a short time course. Cochrane Database Syst Rev . 2004;(2):CD002203. Macrolide antibiotics for cystic fibrosis; Southern KW et al.; BACKGROUND: Chronic severe infection with Pseudomonas aeruginosa, affects many people with cystic fibrosis (CF) . There is evidence from the laboratory and from other disease processes that macrolide antibiotics, whilst not directly active against Pseudomonas aeruginosa, may have indirect actions against this organism . OBJECTIVES: We aimed to test the hypotheses that, in people with CF, macrolide antibiotics:(1) improve clinical status compared to placebo or another antibiotic;(2) do not have unacceptable adverse effects.If benefit was demonstrated, we aimed to assess the optimal type, dose and duration of macrolide therapy . SEARCH STRATEGY: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings.We contacted principal investigators known to work in the field, previous authors and pharmaceutical companies who manufacture macrolide antibiotics for unpublished or follow-up data (December 2003).Most recent search of the Group's register: January 2004 SELECTION CRITERIA: Published or unpublished randomised controlled trials of macrolide antibiotics compared to placebo, another class of antibiotic or another macrolide antibiotic . Studies comparing regimens of the same macrolide antibiotic at different doses will also be included . DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed study quality . Three groups were contacted for missing data and we hope to include these in future reviews . MAIN RESULTS: Searches identified 14 studies, four were included in this review (296 participants) . Two studies enrolled adults, one children (a significant number of whom were not colonised with Pseudomonas aeruginosa) and one both adults and children . All the clinical studies reported small but significant improvements in respiratory function with azithromycin versus placebo . Meta-analysis at the one-month and six-month time points demonstrates a significant benefit with respect to relative change in FEV1 (at six months, for n = 104, azithromycin and n = 114, placebo; WMD 5.82% (95% CI 2.45 to 9.20)) . The largest study reported a significant increase in mild adverse events (nausea, diarrhoea and wheezing) . REVIEWERS' CONCLUSIONS: There is clear evidence from these studies of a small but significant improvement in respiratory function following treatment with azithromycin . The largest study employed a three times a week dose and, in this study, treatment with azithromycin was associated with a significant increase in mild adverse events . Further studies are needed to clarify the precise role of azithromycin in the treatment of CF lung disease. Antimicrob Agents Chemother, 2004 May, 48(5), 1879 - 81 Rapid colorimetric assay for antimicrobial susceptibility testing of Pseudomonas aeruginosa; Tunney MM et al.; A colorimetric assay based on the reduction of a tetrazolium salt {2,3-bis{2-methyloxy-4-nitro-5-sulfophenyl}-2H-tetrazolium-5-carboxanilide (XTT)} for rapidly determining the susceptibility of Pseudomonas aeruginosa isolates to bactericidal antibiotics is described . There was excellent agreement between the tobramycin and ofloxacin MICs determined after 5 h using the XTT assay and after 18 h using conventional methods . The data suggests that an XTT-based assay could provide a useful method for rapidly determining the susceptibility of P . aeruginosa to bactericidal antibiotics. Antimicrob Agents Chemother, 2004 May, 48(5), 1876 - 8 Virulence of metallo-beta-lactamase-producing Pseudomonas aeruginosa in vitro and in vivo; Aoki S et al.; We evaluated the virulence of Pseudomonas aeruginosa carrying bla(IMP), a metallo-beta-lactamase gene, and the efficacy of ceftazidime, imipenem-cilastatin, and ciprofloxacin in the endogenous bacteremia model . The presence of bla(IMP) did not practically change the virulence of the parent strain, and ciprofloxacin was effective against infection with P . aeruginosa carrying bla(IMP). Antimicrob Agents Chemother, 2004 May, 48(5), 1797 - 802 Clinical strains of Pseudomonas aeruginosa overproducing MexAB-OprM and MexXY efflux pumps simultaneously; Llanes C et al.; Simultaneous overexpression of the MexAB-OprM and MexXY efflux systems was demonstrated by real-time reverse transcription-PCR and immunoblotting experiments for 12 multiresistant clinical isolates of Pseudomonas aeruginosa . DNA sequencing analysis showed that nine of these strains (named agrZ mutants) harbored mutations in mexZ, the product of which downregulates the expression of the mexXY operon . In addition, 8 of the 12 strains exhibited mutations in genes known to control transcription of the mexAB-oprM operon . Four of them were nalB mutants with alterations in the repressor gene mexR, three of them appeared to be nalC mutants deficient in gene PA3721 and overexpressing gene PA3720, and one strain was a nalB nalC double mutant . For MexAB-OprM as well as for MexXY, no clear correlation could be established between (i) the types of mutations, (ii) the expression level of mexA or mexX, and (iii) resistance to effluxed antibiotics . Finally, three isolates, named agrW mutants, overproduced MexXY and had an intact mexZ gene, and four strains overproduced MexAB-OprM and had intact mexR and PA3721 genes (nalD mutants) . These data show that clinical isolates are able to broaden their drug resistance profiles by coexpressing two Mex efflux pumps and suggest the existence of additional regulators for MexAB-OprM and MexXY. Antimicrob Agents Chemother, 2004 May, 48(5), 1681 - 7 Pseudomonas aeruginosa LasA protease in treatment of experimental staphylococcal keratitis; Barequet IS et al.; LasA protease is a staphylolytic endopeptidase secreted by Pseudomonas aeruginosa . We have examined the effectiveness of LasA protease in the treatment of staphylococcal keratitis caused by methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S . aureus (MRSA) isolates in a rabbit model . Keratitis was induced by intrastromal injection of the bacteria . The eyes were treated topically, and the efficacy of LasA protease was compared to those of lysostaphin (a staphylolytic protease secreted by Staphylococcus simulans) and vancomycin . When treatment was initiated early (4 h) after infection, practically all of the MSSA- and MRSA-infected corneas were sterilized by LasA protease, and its efficacy in eradicating the bacteria was comparable to those of lysostaphin and vancomycin . By contrast, most of the control corneas were heavily infected, with median values of 4.5 x 10(6) (MSSA) and 5 x 10(5) (MRSA) CFU/cornea (P < 0.001) . When treatment was initiated late (10 h) after infection, LasA protease reduced the numbers of CFU in both MSSA- and MRSA-infected corneas by 3 to 4 orders of magnitude compared to the numbers of CFU for the controls (median values, 1,380 and 30 CFU/cornea, respectively, for the treated animals compared to 1.2 x 10(6) and 5 x 10(5) CFU/cornea for the respective controls {P = 0.001}), and it was more effective than vancomycin in eradicating MRSA cells (P = 0.02) . In both the early- and the late-treatment protocols, the clinical scores for eyes treated with LasA protease were significantly lower than those for the eyes of the corresponding controls and comparable to those for the lysostaphin- and vancomycin-treated eyes . We conclude that LasA protease is effective in the treatment of experimental S . aureus keratitis in rabbits and may have potential for the treatment of disease in humans. Antimicrob Agents Chemother, 2004 May, 48(5), 1676 - 80 Role of the multidrug efflux system MexXY in the emergence of moderate resistance to aminoglycosides among Pseudomonas aeruginosa isolates from patients with cystic fibrosis; Vogne C et al.; This study investigates the role of active efflux system MexXY in the emergence of aminoglycoside (AG) resistance among cystic fibrosis (CF) isolates of Pseudomonas aeruginosa . Three genotypically related susceptible and resistant (S/R) bacterial pairs and three other AG-resistant CF strains were compared to four non-CF strains moderately resistant to AGs . As demonstrated by immunoblot experiments, pump MexY was strongly overproduced in all of the resistant bacteria . This MexXY upregulation was associated with a 2- to 16-fold increase in the MICs of AGs in the S/R pairs and lower intracellular accumulation of dihydrostreptomycin . Alterations in mexZ, the repressor gene of operon mexXY, were found in all of the AG-resistant CF isolates and in one non-CF strain . Complementation of these bacteria with a plasmid-borne mexZ gene dramatically reduced the MICs of AGs, thus highlighting the role played by MexXY in the development of moderate resistance in CF patients . In contrast, complementation of the three non-CF strains showing wild-type mexZ genes left residual levels of resistance to AGs . These data indicate that a locus different from mexZ may be involved in overproduction of MexXY and that other nonenzymatic mechanisms contribute to AG resistance in P . aeruginosa. Cell Microbiol, 2004 Jun, 6(6), 521 - 33 Role of the cystic fibrosis transmembrane conductance regulator in internalization of Pseudomonas aeruginosa by polarized respiratory epithelial cells; Darling KE et al.; Pseudomonas aeruginosa is an important human pathogen, producing lung infection in individuals with cystic fibrosis (CF), patients who are ventilated and those who are neutropenic . The respiratory epithelium provides the initial barrier to infection . Pseudomonas aeruginosa can enter epithelial cells, although the mechanism of entry and the role of intracellular organisms in its life cycle are unclear . We devised a model of infection of polarized human respiratory epithelial cells with P . aeruginosa and investigated the role of the cystic fibrosis transmembrane conductance regulator (CFTR) in adherence, uptake and IL-8 production by human respiratory epithelial cells . We found that a number of P . aeruginosa strains could invade and replicate within cells derived from a patient with CF . Intracellular bacteria did not produce host cell cytotoxicity over a period of 24 h . When these cells were transfected with wild-type CFTR, uptake of bacteria was significantly reduced and release of IL-8 following infection enhanced . We propose that internalized P . aeruginosa may play an important role in the pathogenesis of infection and that, by allowing greater internalization into epithelial cells, mutant CFTR results in an increased susceptibility of bronchial infection with this microbe. Crit Rev Eukaryot Gene Expr, 2004, 14(1-2), 53 - 64 SCE jumping: genetic tool for allelic exchange in bacteria; Wong SM; As more microbial genome sequence information becomes available, the field of bacterial pathogenesis would benefit from the development of new genetic tools designed to facilitate gene function studies on a genomic scale . The complete DNA sequence of the bacterium Pseudomonas aeruginosa provides an opportunity to apply functional genomics to a major opportunistic human pathogen . Here, I describe the development of a new gene replacement scheme termed "SCE jumping" in P . aeruginosa . The system uses the yeast I-SceI homing endonuclease in conjunction with in vitro mariner-transposon mutagenesis to generate mutations within targeted regions of the chromosome for genetic footprinting . Use of SCE jumping for generating transposon insertion mutants is anticipated to be widely applicable to other bacterial organisms . This allelic exchange strategy is discussed in context with other methods of gene replacement strategies available in P . aeruginosa . Development of SCE jumping provides an excellent example of the power of importing systems from unrelated organisms to circumvent practical challenges in molecular genetics. Ulus Travma Derg, 2004 Apr, 10(2), 110 - 4 {Clinical evaluation and treatment results of 30 patients with necrotizing fasciitis}; Ozgenel GY et al.; BACKGROUND: We retrospectively evaluated patients who underwent treatment for necrotizing fasciitis within a five-year period . METHODS: Thirty patients (4 females, 26 males; mean age 55 years; range 19 to 78 years) with necrotizing fasciitis were evaluated with respect to age, sex, etiology, predisposing factors, localization of infections, culture results, and treatment methods and results . RESULTS: The most common etiologic and predisposing factors were anorectal lesions (36.7%) and diabetes (53.3%), respectively . Wound cultures yielded Pseudomonas aeruginosa in 50% of the patients . Two strains of aerobic bacteria were isolated in three patients . All patients underwent extensive surgical debridement and received antibiotic therapy . Twenty-nine patients (96.6%) required more than one debridement, with a mean of 4.5 debridements . The ensuing skin defects following debridement were reconstructed with grafts or local flaps . No complications were encountered in the postoperative period . CONCLUSION: Early diagnosis and treatment result in decreased morbidity and prevent mortality in necrotizing fasciitis. Acta Crystallogr D Biol Crystallogr, 2004 May, 60(Pt 5), 948 - 9 Epub 2004 Apr 21. Crystallization and preliminary X-ray crystallographic analysis of nicotinic acid mononucleotide adenylyltransferase from Pseudomonas aeruginosa; Kim HL et al.; The enzyme nicotinic acid mononucleotide adenylyltransferase (NaMN AT; EC 2.7.7.18) is essential for the synthesis of nicotinamide adenine dinucleotide and is a potential target for antibiotics . It catalyzes the transfer of an adenyl group from ATP to nicotinic acid mononucleotide to form nicotinic acid adenine dinucleotide . NaMN AT from Pseudomonas aeruginosa was overexpressed in Escherichia coli and crystallized at 291 K using 100 mM bis-Tris propane pH 7.0, 700 mM trisodium citrate and 15%(v/v) glycerol . X-ray diffraction data have been collected to 1.70 A . The crystals are tetragonal, belonging to space group P4(1)22 (or P4(3)22), with unit-cell parameters a = b = 65.02, c = 109.80 A . The presence of one monomer in the asymmetric unit gives a reasonable V(M) of 2.15 A(3) Da(-1), with a solvent content of 42.7%. Infect Immun, 2004 May, 72(5), 2899 - 906 The alternative activation pathway and complement component C3 are critical for a protective immune response against Pseudomonas aeruginosa in a murine model of pneumonia; Mueller-Ortiz SL et al.; Pseudomonas aeruginosa is a leading cause of hospital-acquired pneumonia, and approximately 80% of patients with cystic fibrosis are infected with this bacterium . To investigate the overall role of complement and the complement activation pathways in the host defense against P . aeruginosa pulmonary infection, we challenged C3-, C4-, and factor B-deficient mice with P . aeruginosa via intranasal inoculation . In these studies, C3(-/-) mice had a higher mortality rate than C3(+/+) mice . Factor B(-/-) mice, but not C4(-/-) mice, infected with P . aeruginosa had a mortality rate similar to that of C3(-/-) mice, indicating that in this model the alternative pathway of complement activation is required for the host defense against Pseudomonas infection . C3(-/-) mice had 6- to 7-fold more bacteria in the lungs and 48-fold more bacteria in the blood than did C3(+/+) mice at 24 h postinfection . In vitro, phagocytic cells from C3(+/+) or C3(-/-) mice exhibited a decreased ability to bind and/or ingest P . aeruginosa in the presence of C3-deficient serum compared to phagocytic cells in the presence of serum with sufficient C3 . C3(-/-) mice displayed a significant increase in neutrophils in the lungs and had higher levels of interleukin-1beta (IL-1beta), IL-6, IL-10, KC, and MIP-2 in the lungs at 24 h postinfection than did C3(+/+) mice . Collectively, these results indicate that complement activation by the alternative pathway is critical for the survival of mice infected with P . aeruginosa and that the protection provided by complement is at least in part due to C3-mediated opsonization and phagocytosis of P . aeruginosa. BMC Struct Biol . 2004 Mar 08;4(1):5. Crystal structure of the YffB protein from Pseudomonas aeruginosa suggests a glutathione-dependent thiol reductase function; Teplyakov A et al.; BACKGROUND: The yffB (PA3664) gene of Pseudomonas aeruginosa encodes an uncharacterized protein of 13 kDa molecular weight with a marginal sequence similarity to arsenate reductase from Escherichia coli . The crystal structure determination of YffB was undertaken as part of a structural genomics effort in order to assist with the functional assignment of the protein . RESULTS: The structure was determined at 1.0 A resolution by single-wavelength anomalous diffraction . The fold is very similar to that of arsenate reductase, which is an extension of the thioredoxin fold . CONCLUSION: Given the conservation of the functionally important residues and the ability to bind glutathione, YffB is likely to function as a GSH-dependent thiol reductase. Mol Microbiol, 2004 May, 52(3), 873 - 93 Characterization of a complex chemosensory signal transduction system which controls twitching motility in Pseudomonas aeruginosa; Whitchurch CB et al.; Virulence of the opportunistic pathogen Pseudomonas aeruginosa involves the coordinate expression of a wide range of virulence factors including type IV pili which are required for colonization of host tissues and are associated with a form of surface translocation termed twitching motility . Twitching motility in P . aeruginosa is controlled by a complex signal transduction pathway which shares many modules in common with chemosensory systems controlling flagella rotation in bacteria and which is composed, in part, of the previously described proteins PilG, PilH, PilI, PilJ and PilK . Here we describe another three components of this pathway: ChpA, ChpB and ChpC, as well as two downstream genes, ChpD and ChpE, which may also be involved . The central component of the pathway, ChpA, possesses nine potential sites of phosphorylation: six histidine-containing phosphotransfer (HPt) domains, two novel serine- and threonine-containing phosphotransfer (SPt, TPt) domains and a CheY-like receiver domain at its C-terminus, and as such represents one of the most complex signalling proteins yet described in nature . We show that the Chp chemosensory system controls twitching motility and type IV pili biogenesis through control of pili assembly and/or retraction as well as expression of the pilin subunit gene pilA . The Chp system is also required for full virulence in a mouse model of acute pneumonia. Mol Microbiol, 2004 May, 52(3), 691 - 700 A new Ralstonia solanacearum high-affinity mannose-binding lectin RS-IIL structurally resembling the Pseudomonas aeruginosa fucose-specific lectin PA-IIL; Sudakevitz D et al.; The plant pathogen Ralstonia solanacearum produces two lectins, each with different affinity to fucose . We described previously the properties and sequence of the first lectin, RSL (subunit M(r) 9.9 kDa), which is related to fungal lectins (Sudakevitz, D., Imberty, A., and Gilboa-Garber, N., 2002, J Biochem 132: 353-358) . The present communication reports the discovery of the second one, RS-IIL (subunit M(r) 11.6 kDa), a tetrameric lectin, with high sequence similarity to the fucose-binding lectin PA-IIL of Pseudomonas aeruginosa . RS-IIL recognizes fucose but displays much higher affinity to mannose and fructose, which is opposite to the preference spectrum of PA-IIL . Determination of the crystal structure of RS-IIL complexed with a mannose derivative demonstrates a tetrameric structure very similar to the recently solved PA-IIL structure (Mitchell, E., et al., 2002, Nature Struct Biol 9: 918-921) . Each monomer contains two close calcium cations that mediate the binding of the monosaccharide and explain the outstandingly high affinity to the monosaccharide ligand . The binding loop of the cations is fully conserved in RS-IIL and PA-IIL, whereas the preference for mannose versus fucose can be attributed to the change of a three-amino-acid sequence in the 'specificity loop'. Otolaryngol Head Neck Surg, 2004 Apr, 130(4), 430 - 6 Hearing loss with semicircular canal fistula in exotoxin A-deficient Pseudomonas otitis media; Yunus TM et al.; OBJECTIVE: The study goal was to compare the severity of hearing loss with semicircular canal injury in the presence of otitis media (OM) due to an exotoxin A-producing strain of Pseudomonas aeruginosa (PA+) and an exotoxin A-deficient daughter strain (PA-) . METHODS: PA+ or PA- was injected bilaterally into guinea pig ears . Three days later, unilateral lateral semicircular canal transection was performed . Hearing was tested before and after transection . RESULTS: PA OM was induced in all injected ears . Significant elevation of click and 12-kHz thresholds (P < 0.0001) were encountered in PA+-infected ears . No significant threshold elevations were encountered in PA--infected ears . CONCLUSION: Hearing loss resulting from canal injury in the presence of Pseudomonas OM may be mediated by exotoxin A . SIGNIFICANCE: Treatment to neutralize the effects of exotoxin A may minimize the risk of hearing loss with canal fistula in chronic OM. Biochim Biophys Acta, 2004 Apr 12, 1655(1-3), 59 - 63 Electron tunneling in rhenium-modified Pseudomonas aeruginosa azurins; Miller JE et al.; Laser flash-quench methods have been used to generate tyrosine and tryptophan radicals in structurally characterized rhenium-modified Pseudomonas aeruginosa azurins . Cu(I) to "Re(II)" electron tunneling in Re(H107) azurin occurs in the microsecond range . This reaction is much faster than that studied previously for Cu(I) to Ru(III) tunneling in Ru(H107) azurin, suggesting that a multistep ("hopping") mechanism might be involved . Although a Y108 radical can be generated by flash-quenching a Re(H107)M(II) (M=Cu, Zn) protein, the evidence suggests that it is not an active intermediate in the enhanced Cu(I) oxidation . Rather, the likely explanation is rapid conversion of Re(II)(H107) to deprotonated Re(I)(H107 radical), followed by electron tunneling from Cu(I) to the hole in the imidazole ligand. J Ethnopharmacol, 2004 May, 92(1), 135 - 44 Evaluation of extracts of Anthocleista djalonensis, Nauclea latifolia and Uvaria afzalii for activity against bacterial isolates from cases of non-gonococcal urethritis; Okoli AS et al.; Whole root preparations of three Nigerian medicinal plants, Anthocleista djalonensis, Nauclea latifolia and Uvaria afzalii, used traditionally in combination treatment of sexually transmitted diseases (STD), were extracted by maceration in ethanol, cold and hot water, respectively . The extracts were tested, by agar diffusion and macrobroth dilution methods, for activity against five strains of Staphylococcus aureus and two of Escherichia coli isolated from cases of STD and or urethritis . Four typed bacterial strains, S aureus ATCC 12600, Bacillus subtilis ATCC 6051, Pseudomonas aeruginosa ATCC 10145 and Escherichia coli ATCC 117755 were included as reference organisms . Ethanolic and cold-water extracts of Anthocliesta djalonensis exhibited activity against 9 and 7, respectively, of the 11 test organisms . They were bacteriostatic at minimum inhibitory concentrations (MIC) to the Gram positive strains but bactericidal to the Gram negative strains . Similar crude extracts of Uvaria afzalii showed bactericidal activity restricted to Gram positive (Staphylococcus aureus and Bacillus subtilis) strains . Nauclea latifolia extracts were bacteriostatic to both Gram positive and Gram negative strains . No test strain was susceptible to the hot water extracts of Nauclea latifolia but five and seven strains, were respectively susceptible to similar extracts of Anthocliesta djalonensis and Uvaria afzalii . Of the seven column chromatographic fractions of the ethanolic extract of Uvaria afzalii, F(ua-1) exhibited a bactericidal activity restricted to the Gram negative Escherichia coli strains, which were not susceptible to the crude extract . Fractions, F(ua-2), F(ua-3) and F(ua-4), like the crude extract, were bactericidal against the Gram positive strains only . Thus, partial purification seems to broaden the spectrum of activity and generally improve the potency of Uvaria afzalii . These results apparently justify the use of the three plants in treatment of STD . Acta Microbiol Pol, 2003, 52(4), 419 - 23 Adherence of Pseudomonas aeruginosa to human buccal epithelial cells; Wolska K et al.; The aim of this study was to evaluate adherence of 83 strains of Pseudomonas aeruginosa isolated from humans and different animals to trypsin-treated buccal cells . We have demonstrated that Pseudomonas aeruginosa attached to trypsin-treated buccal cells in far greater numbers than to cells from controls (normal buccal epithelial cells) . The mean number of bacteria adhering to trypsin-treated cells amounted 107.05 +/- 102.16 and to normal cells - 6.97 +/- 3.53 . We conclude that exposure of cells to proteolytic enzymes increases Pseudomonas aeruginosa binding to buccal cells. Pediatr Pulmonol, 2004 May, 37(5), 427 - 32 Antibody response to Pseudomonas aeruginosa in cystic fibrosis patients: a marker of therapeutic success?--A 30-year cohort study of survival in Danish CF patients after onset of chronic P . aeruginosa lung infection; Johansen HK et al.; We studied the effects of increasingly intensive treatment regimens on anti-pseudomonal antibody response and survival in five successive cohorts of a total of 157 Danish cystic fibrosis patients after they had acquired chronic P . aeruginosa lung infection . The time periods were 1971-1975 (N = 21), 1976-1980 (N = 64), 1981-1986 (N = 27), 1987-1993 (N = 26), and 1994-2000 (N = 19) . During this 30-year period, we introduced elective 2-week courses of chemotherapy every third month in all chronically infected patients, early aggressive treatment with inhalation of colistin and oral ciprofloxacin for 3 months whenever P . aeruginosa was cultured in sputum from noncolonized patients, and inhalation of recombinant human dornase alfa . There was a significant correlation between the calendar year when chronic P . aeruginosa infection was acquired and the subsequent increase in the level of precipitins (P < 0.00001) . The median number of precipitins increased by 5 per year in the oldest calendar year cohort, and 1 per year in the youngest . The median age of onset of chronic P . aeruginosa increased from 9.3 years from 1981-1986 to 13.8 years from 1987-2000 . Survival after acquisition of chronic P . aeruginosa lung infection improved with time (P = 0.008) . Our study shows that CF patients who are treated intensively have lower antibody responses and longer survival after acquisition of chronic P . aeruginosa lung infection . Pediatr Pulmonol, 2004 May, 37(5), 407 - 12 Disease severity in siblings with cystic fibrosis; Katz SL et al.; Since cross-infection occurs between cystic fibrosis (CF) siblings, we hypothesized that subsequent siblings may acquire respiratory pathogens at an earlier age and have a more severe course of pulmonary disease . We studied a retrospective cohort of 31 sibling pairs from the CF database at the Hospital for Sick Children . Kaplan-Meier curves and modified log-rank tests were used to test sibling differences in age of acquisition of Pseudomonas aeruginosa (PA), Staphylococcus aureus (SA), or any positive culture . Differences in disease severity outcomes were explored . Older siblings were more likely to have both SA and any CF pathogen first isolated from respiratory culture at an older age than younger siblings (P = 0.0050 and P = 0.0008, respectively, by modified log-rank tests) . However, more of the older siblings were positive on first culture at time of diagnosis, introducing an age-of-diagnosis bias . Hospitalization rates, courses of oral antibiotics, FEV(1) % predicted, and weight and height measurements were not better in the older children . No differences in clinical parameters were found between older and younger siblings . The apparent finding of younger age at first isolation of pathogens from respiratory cultures in younger siblings is likely because many older siblings were already infected with these organisms at time of diagnosis . Pediatr Pulmonol, 2004 May, 37(5), 400 - 6 Pulmonary exacerbations in cystic fibrosis; Rabin HR et al.; The clinical characteristics most relevant to the decision to treat for a pulmonary exacerbation with antibiotics in cystic fibrosis patients were determined . Variables including age, increased cough frequency and sputum production, new crackles and wheezing, asthma, symptomatic sinusitis, hemoptysis, decreased lung function, weight loss, and new acquisition of Pseudomonas aeruginosa were collected in a large prospective multicenter database (Epidemiologic Study of Cystic Fibrosis) . During a 12-month baseline period, data from 11692 patients were compared with data collected during the subsequent 6-month study period . Because pulmonary function assessments were unavailable for patients <6 years of age, separate analyses were done for those <6 and >or=6 years of age . The outcome of interest was any antibiotic treatment in the 6-month study period reported as indicated for an exacerbation . Characteristics with the most discriminatory power were determined using stepwise multiple logistic regression . For patients <6 years of age, the strongest independent associations with treatment for a pulmonary exacerbation were new crackles, increased cough frequency, decline in weight, and increased sputum production . For those patients >or=6 years of age, the strongest independent associations were a relative decrease in percent predicted forced expired volume in 1 sec, increased cough frequency, new crackles, and hemoptysis . The presence of three or more of these key characteristics was strongly associated with the occurrence of a treated exacerbation . The reproducibility of the model over time was confirmed by application to a subsequent set of data . This model has potential for use as an outcome measure in clinical trials, and to assist in treatment decisions for individual patients . Eye, 2004 Sep, 18(9), 935 - 7 Continuous wear silicone hydrogel contact lenses and microbial keratitis; Whiting MA et al.; Like other lens types, the new generation of silicone hydrogel contact lenses can be associated with a spectrum of ocular complications . Most tend to be very minor, but serious and sight-threatening complications can occur . We present four such cases with microbial keratitis following extended wear of these lenses . Cultures were positive for Pseudomonas aeruginosa in three cases and all three of these suffered lasting visual impairment . We describe our findings and discuss possible risk factors. FEBS Lett, 2004 Apr 23, 564(1-2), 69 - 72 Characterisation of the PQQ cofactor radical in quinoprotein ethanol dehydrogenase of Pseudomonas aeruginosa by electron paramagnetic resonance spectroscopy; Kay CW et al.; The binding pocket of the pyrroloquinoline quinone (PQQ) cofactor in quinoprotein alcohol dehydrogenases contains a characteristic disulphide ring formed by two adjacent cysteine residues . To analyse the function of this unusual structural motif we have investigated the wild-type and a double cysteine:alanine mutant of the quinoprotein ethanol dehydrogenase from Pseudomonas aeruginosa by electron paramagnetic resonance (EPR) spectroscopy . Thus, we have obtained the principal values for the full rhombic g-tensor of the PQQ semiquinone radical by high-field (94 GHz) EPR necessary for a discrimination of radical species in dehydrogenases containing PQQ together with other redox-active cofactors . Our results show that the characteristic disulphide ring is no prerequisite for the formation of the functionally important semiquinone form of PQQ. J Cataract Refract Surg, 2004 Apr, 30(4), 884 - 91 Prevention of experimental diffuse lamellar keratitis using a novel platelet-activating factor receptor antagonist; Esquenazi S et al.; PURPOSE: To determine whether a novel platelet-activating factor (PAF) antagonist prevents experimentally induced diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK) . SETTINGS: Department of Ophthalmology and Neuroscience Center of Excellence, Louisiana State University Health Science Center, New Orleans, Louisiana, USA . METHODS: Twenty eyes of 10 New Zealand albino rabbits were used . The left eyes were treated with a peribulbar injection of 0.5 mL of PAF receptor antagonist LAU 0901 (2,4,6-trimethyl-1,4-dihydropyridine-3,5-dicarboxylic acid ester) dissolved in 20 hydroxypropyl B cyclodextrin (30 microg /mL) . Two rabbits were treated with a peribulbar injection of 0.5 mL of vehicle (cyclodextrin) alone and served as controls . A corneal flap was cut in all eyes, and the interface was exposed to Pseudomonas aeruginosa endotoxin . The left eyes were additionally treated with 1 drop of LAU 0901 4 times a day . Rabbits were killed on postoperative days 1, 2, 3, 5, and 8 . The eyes were enucleated and processed for histopathology and immunohistochemical examination . RESULTS: Corneas not treated with LAU 0901 and controls showed a severe inflammatory response in the flap margin and stromal interface, characterized by loss of keratocytes, activation of adjacent keratocytes and transformation to myofibroblasts, infiltration of polymorphonuclear leukocytes and monocytes, and presence of epithelial cells with necrosis and melting of adjacent stroma . Corneas of rabbits treated with LAU 0901 showed minimal loss of keratocytes and myofibroblast transformation, minimal inflammatory cell infiltration, and minimal presence of epithelial cells in the interface . CONCLUSION: Induction of DLK was blocked by a PAF receptor antagonist in rabbit eyes . The histopathological evaluation and immunohistochemical studies showed that treatment with LAU 0901 blocked keratocyte apoptosis, transformation of fibroblasts to myofibroblasts and migration to the wound site, and chemotaxis of inflammatory cells, inhibiting the inflammatory response and promoting adequate healing of the flap interface and adjacent stroma. J Bacteriol, 2004 May, 186(9), 2523 - 31 Structural and genetic characterization of glycosylation of type a flagellin in Pseudomonas aeruginosa; Schirm M et al.; Type a flagellins from two strains of Pseudomonas aeruginosa, strains PAK and JJ692, were found to be glycosylated with unique glycan structures . In both cases, two sites of O-linked glycosylation were identified on each monomer, and these sites were localized to the central, surface-exposed domain of the monomer in the assembled filament . The PAK flagellin was modified with a heterogeneous glycan comprising up to 11 monosaccharide units that were O linked through a rhamnose residue to the protein backbone . The flagellin of JJ692 was less complex and had a single rhamnose substitution at each site . The role of the glycosylation island gene cluster in the production of each of these glycosyl moieties was investigated . These studies revealed that the orfA and orfN genes were required for attachment of the heterologous glycan and the proximal rhamnose residue, respectively. J Spinal Disord, 2004 Apr, 17(2), 112 - 114 Histopathologic Effects of Discitis on Neural Tissues : An Experimental Study; Yucesoy K et al.; To determine the cause of neurologic symptoms and signs seen in discitis, the neural histopathologic effects of discitis were investigated in an experimental study carried out on rats . Groups of seven rats each had their intervertebral discs inoculated with either Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, or a control solution . Histopathologic examinations of the spinal cord and nerve roots were performed after 3 weeks . On histopathologic examination, vacuolar myelopathy in the spinal cord and vacuolar neuropathy within the nerve roots near the junction with the spinal cord were found . The severity and form of vacuolar myelopathy varied according to the bacteria used for inoculation . The myelopathy and neuropathy seen in this rat model of bacterial discitis might be the result of an immunologic mechanism and could be responsible for the neurologic signs and symptoms of discitis in patients. Shock, 2004 May, 21(5), 458 - 65 Selective inducible nitric oxide synthase inhibition during long-term hyperdynamic porcine bacteremia; Matejovic M et al.; We have recently demonstrated that selective inducible nitric oxide (NO) synthase (iNOS) inhibition with 1400W attenuated the hemodynamic and metabolic alterations affiliated with hyperdynamic porcine endotoxemia . In contrast to endotoxemia, limited evidence is available to document a relationship between NO and organ dysfunction in large animal bacteremic models . Therefore, using the same experimental setup, we investigated the role of selective iNOS blockade in porcine bacteremia induced and maintained for 24 h with a continuous infusion of live Pseudomonas aeruginosa . After 12 h of sepsis, animals received either vehicle (Control, n = 8) or continuous infusion of selective iNOS inhibitor, L-N6-(1-iminoethyl)-lysine (L-NIL; n = 8) . Measurements were performed before, and 12, 18, and 24 h after P . aeruginosa infusion . L-NIL inhibited sepsis-induced increase in plasma nitrate/nitrite concentrations and prevented hypotension without affecting cardiac output . Despite comparable hepatosplanchnic macrocirculation, L-NIL blunted the progressive deterioration in ileal mucosal microcirculation and prevented mucosal acidosis . L-NIL largely attenuated mesenteric and hepatic venous acidosis, significantly improved P . aeruginosa-induced impairment of hepatosplanchnic redox state, and mitigated the decline in liver lactate clearance . Furthermore, the administration of L-NIL reduced the hepatocellular injury and prevented the development of renal dysfunction . Finally, treatment with L-NIL significantly attenuated the formation of 8-isoprostane concentrations, a direct marker of lipid peroxidation . Thus, selective iNOS inhibition with L-NIL prevented live bacteria from causing key features of metabolic derangements in porcine hyperdynamic sepsis . Underlying mechanisms probably include reduced oxidative stress with improved microcirculatory perfusion and restoration of cellular respiration. Shock, 2004 May, 21(5), 444 - 51 Massive alveolar thrombin activation in Pseudomonas aeruginosa-induced acute lung injury; Kipnis E et al.; In acute lung injury (ALI), a coagulation/fibrinolysis imbalance leads to fibrin deposition, persistence of which contributes to fibrotic evolution . Our study evaluated the effects of early inhibition of coagulation in Pseudomonas aeruginosa (Pa)-induced ALI through the use of recombinant human antithrombin (rhAT) . The study was conducted in vivo on a murine model of Pa-induced ALI . Intravenous rhAT was administered simultaneously with intratracheal Pa . Four experimental groups were compared: CTR, intratracheal saline (0.5 mL/kg)/intravenous saline (1 mL); PNP, intratracheal Pa (0.5 mL/kg of 2 x 10(9) cfu)/intravenous saline; AT, intratracheal saline/intravenous rhAT (500 IU/kg); ATPNP, intratracheal Pa/intravenous rhAT . Epithelial and endothelial permeabilities were evaluated with radiolabeled albumin flux across the alveolar barrier (125I- and 131I-labeled albumin) . Thrombin-antithrombin (TAT) complexes levels were used as markers of coagulation activation in blood samples and in BAL fluid . Epithelial and endothelial protein permeability were increased in Pa-induced ALI versus control . Intravenous rhAT administration led to further permeability disorders . Administration of rhAT in Pa ALI led to a rise in TAT complexes in ATPNP blood serum and BAL fluids compared with the other groups . In Pa-induced ALI the administration intravenous rhAT leads to major histologic damage, alveolar capillary barrier injury, and permeability increase . Such effects of the inhibition of thrombin activation by rhAT lead to the hypothesis of a probable beneficial role of early coagulation activation in ALI as a factor limiting both the extent of injury and permeability disorders . Our study suggests that inhibition of this initial procoagulative imbalance is potentially dangerous. Shock, 2004 May, 21(5), 415 - 25 Diminished bacterial clearance is associated with decreased IL-12 and interferon-gamma production but a sustained proinflammatory response in a murine model of postseptic immunosuppression; Murphey ED et al.; After a major illness or injury, immune status in critically ill patients may fluctuate between a marked proinflammatory response and an immunosuppressed state . Postinflammatory immunosuppression can result in increased susceptibility to infection . Alterations of cytokine production, such as suppression of IFNgamma and elevation of the anti-inflammatory cytokine IL-10, are believed to contribute to postinflammatory immunosuppression . We examined antimicrobial immunity in mice that had previously been subjected to a sublethal cecal ligation and puncture (CLP) as a model of major injury . Mice were challenged with Pseudomonas aeruginosa (5 x 10(7) CFU i.v.) on day 5 after CLP or sham surgery . Bacterial clearance in mice after CLP was impaired and associated with decreased production of IFNgamma and increased production of IL-10 in the early response to the Pseudomonas challenge . Pseudomonas-induced production of the IFNgamma-inducing factor IL-12 was also decreased in post-CLP mice . However, splenocytes from post-CLP mice remained responsive to exogenous stimulation with the IFNgamma-inducing cytokines IL-12, IL-15, and IL-18 as well as T-cell receptor activation . Furthermore, production of the proinflammatory cytokines TNF-alpha, IL-1beta, and IL-6 were as high, or higher, in the post-CLP group compared with sham mice after P . aeruginosa challenge . Blockade of IL-10 did not reverse IL-12 and IFNgamma suppression in splenocytes from post-CLP mice . These studies show that suppressed bacterial clearance in post-CLP mice is associated with decreased production of IFNgamma and IL-12 and with increased production of IL-10 and proinflammatory cytokines. Chemotherapy, 2004 Apr, 50(1), 31 - 4 Comparative activity of beta-lactam agents (carbapenem excepted) against Pseudomonas aeruginosa strains with CARB or OXA beta-lactamases; Bert F et al.; BACKGROUND: Ticarcillin resistance in Pseudomonas aeruginosa can be mediated by various beta-lactamases of the CARB and OXA groups . METHODS: We investigated the activity of seven beta-lactam agents and two beta-lactam-beta-lactamase inhibitor combinations against 216 P.aeruginosa strains with genotypically characterized beta-lactamases, including 137 CARB, 31 OXA-35, 25 OXA-10, 13 OXA-1 and 10 OXA-2 . MICs were determined by the agar dilution method . RESULTS: The activities of ticarcillin and piperacillin were more affected by CARB than by OXA enzymes . beta-Lactamase inhibitors were poorly effective against OXA-1, OXA-35 and OXA-10 . OXA-1 conferred resistance to cefepime and cefpirome but not to cefsulodin and aztreonam . Ceftazidime remained the most active agent against all groups of enzymes . Major differences in the susceptibility rates according to NCCLS and CASFM breakpoints were observed . CONCLUSIONS: Significant differences were found in the resistance profile associated with the various types of CARB and OXA beta-lactamases in P . aeruginosa . Chemotherapy, 2004 Apr, 50(1), 27 - 30 Serum bactericidal activity of piperacillin/tazobactam against Staphylococcus aureus, piperacillin-susceptible and piperacillin-resistant Escherichia coli and Pseudomonas aeruginosa; Lemmen SW et al.; BACKGROUND: The serum bactericidal test measures the highest level of an antibiotic-containing serum dilution at which 99.9% of bacteria are killed . In this study the serum bactericidal activity of piperacillin/tazobactam was determined for bacteria often involved in severe infections . In earlier studies titres >/=1:8 in the serum bactericidal tests correlated well with clinical success in the treatment of endocarditis and osteomyelitis as well as bacterial eradication . METHODS: Blood samples of 6 healthy volunteers were taken before and 1 and 4 h after piperacillin/tazobactam (4.5 g) administration . Serum concentrations and serum bactericidal activity were determined for 10 strains each of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, both piperacillin-resistant and piperacillin-susceptible according to NCCLS guidelines . RESULTS: 100% of S . aureus and piperacillin-susceptible E . coli, 90% of piperacillin-resistant E . coli and 80% of P . aeruginosa were killed 1 h after drug administration . 4 h after drug administration serum bactericidal activity decreased to 60% for S . aureus, 90% for piperacillin-susceptible E . coli, 80% for piperacillin-resistant E . coli and 30% for P . aeruginosa . CONCLUSIONS: Excellent serum bactericidal activity of piperacillin/tazobactam was recorded 1 h after drug administration for S . aureus, E . coli and P . aeruginosa . After 4 h limited killing rates for P . aeruginosa could be detected, which supports the idea of a combination therapy . Chemotherapy, 2004 Apr, 50(1), 22 - 6 A multidrug efflux pump inhibitor reduces fluoroquinolone resistance in Pseudomonas aeruginosa isolates; Coban AY et al.; In general, resistance to fluoroquinolones (FQs) in gram-negative bacteria is acquired either by mutations in DNA gyrase and topoisomerase IV or by active export of the agents via antibiotic efflux pumps . Reduced porin expression is also proposed to be another mechanism leading to resistance . In this study, interaction between levofloxacin, ofloxacin, and ciprofloxacin with MC-207,110 (multidrug efflux pump inhibitor) was investigated by a checkerboard assay using Pseudomonas aeruginosa . Levofloxacin, ofloxacin, and ciprofloxacin were tested at different concentrations (0.06-64 microg/ml) and MC-207,110 was tested at a concentration range of 4-128 microg/ml . In the presence of MC-207,110 (at 128, 64, 32, 16 microg/ml) resistance to FQs was inhibited significantly and MIC values were decreased, except at 8 and 4 microg/ml of MC-207,110 . When MC-207,110 was used, resistance of P . aeruginosa to FQs in vitro was inhibited significantly, suggesting that MC-207,110 may be useful for use in clinical treatment protocols to overcome FQs resistance . Proc Natl Acad Sci U S A, 2004 Apr 27, 101(17), 6664 - 8 Epub 2004 Apr 14. Pseudomonas aeruginosa regulates flagellin expression as part of a global response to airway fluid from cystic fibrosis patients; Wolfgang MC et al.; Cystic fibrosis (CF) patients are highly susceptible to chronic lung infections by the environmental bacterium Pseudomonas aeruginosa . The overproduction and accumulation of dehydrated viscous respiratory mucus and excessive inflammation represents a defining feature of CF and constitutes the major environment encountered by P . aeruginosa during chronic infections . We applied whole-genome microarray technology to investigate the ability of P . aeruginosa to respond to signals found in muco-purulent airway liquids collected from chronically infected CF patients . Particularly notable was the activation of the Rhl-dependent quorum-sensing (QS) network and repression of fliC, which encodes flagellin . Activation of the Rhl branch of the QS network supports the observation that QS molecules are produced in the chronically infected CF lung . The shut-off of flagellin synthesis in response to CF airway liquids was rapid and independent of QS and the known regulatory networks controlling the hierarchical expression of flagellar genes . As flagellin is highly immunogenic and subject to detection by host pattern recognition receptors, its repression may represent an adaptive response that allows P . aeruginosa to avoid detection by host defense mechanisms and phagocytosis during the chronic phase of CF lung infections. Biotechnol Bioeng, 2004 May 5, 86(3), 365 - 73 Kinetics and mechanism of a reaction catalyzed by PST-01 protease from Pseudomonas aeruginosa PST-01; Bobe IM et al.; The initial rates of carboxybenzoyl-alanyl-l-leucyl-amide (Z-L-Ala-L-Leu-NH(2)) synthesis from carboxybenzoyl-L-alanine (Z-L-Ala) and L-leucineamide (L-Leu-NH(2)) and Z-L-Ala-L-Leu-NH(2) hydrolysis in a homogeneous dimethyl sulfoxide-aqueous buffer solution {1:1 (v/v)} system catalyzed by PST-01 protease from Pseudomonas aeruginosa were measured under a wide range of Z-L-Ala, L-Leu-NH(2) and Z-L-Ala-L-Leu-NH(2) concentrations . The initial rates of the synthetic reaction, in which Z-L-Ala-L-Leu-NH(2) was produced from Z-L-Ala and L-Leu-NH(2), were inhibited by the substrates . Furthermore, the initial rates of the synthetic reaction were not inhibited by the product Z-L-Ala-L-Leu-NH(2), and those of the hydrolytic reaction were inhibited by Z-L-Ala and L-Leu-NH(2) . All the initial rate data of the synthetic and hydrolytic reactions were well correlated with the rate equation derived based on the proposed reaction scheme . Int J Pharm, 2004 May 4, 275(1-2), 171 - 87 Factorial design, physicochemical characterisation and activity of ciprofloxacin-PLGA nanoparticles; Dillen K et al.; Poly(lactide-co-glycolide) nanoparticles incorporating ciprofloxacin HCl were prepared by means of a W/O/W emulsification solvent evaporation method . The stabiliser selected was poly(vinylalcohol) . A 2(4) full factorial design based on four independent variables was used to plan the experiments and the variable parameters were the number of homogenisation cycles, addition of boric acid to the inner water phase containing the drug, ciprofloxacin concentration in the inner water phase and oil:outer water phase ratio . The effects of these parameters on the particle size, zeta potential, drug loading efficiency and drug release were investigated . Also the effect of gamma irradiation on the particle size and drug release was evaluated and DSC and XRD analyses of the compounds and the nanoparticles were performed . The activity on two series of microorganisms, Pseudomonas aeruginosa and Staphylococcus aureus, was examined. Int J Antimicrob Agents, 2004 Apr, 23(4), 401 - 4 Frequency of Gram-negative bacterial pathogens in bloodstream infections and their resistance to antibiotics in the Czech Republic; Cermak P et al.; A study performed at 12 hospitals in the Czech Republic in 2001 evaluated the Gram-negative bacterial pathogens most frequently associated with bloodstream infections and their susceptibility to a selection of antimicrobial agents . Of 831 Gram-negative strains, the most frequently isolated organisms were Escherichia coli (32%), Klebsiella pneumoniae (24%) and Pseudomonas aeruginosa (10%) . E . coli isolates were relatively susceptible to the antibiotics tested, whereas K . pneumoniae were relatively resistant to all agents except meropenem, and P . aeruginosa to all agents except gentamicin and amikacin . Other agents showed variable rates of resistance to penicillins, third-generation cephalosporins, aminoglycosides and ciprofloxacin. J Appl Microbiol, 2004, 96(5), 1124 - 32 A rapid method for the evaluation of both extrinsic and intrinsic contamination and resulting spoilage of water-in-oil emulsions; O'May GA et al.; AIMS: To develop a method for studying the microbial spoilage of water-in-oil emulsions and to use this to investigate (i) the intrinsic stability of water-in-oil formulations and (ii) Pseudomonas aeruginosa SP1-induced spoilage of a proprietary emulsion . METHODS AND RESULTS: Aliquots of test emulsion were placed into wells of a microtitre plate and the opacity (492 nm) monitored at 120-min intervals over several hours . Cracking of the emulsion was associated with marked reductions in opacity . Rate and extent of change in O.D . could be used as indicators of spoilage . Spoilage of a laboratory emulsion formulation was investigated where microorganisms with demonstrated spoilage potential were incorporated either into the water phase prior to emulsification or where the proportion of contaminated water droplets was varied by dilution of contaminated emulsion with a sterile formulation . Results suggested that the route of introduction was a critical determinant of the probability of gross spoilage . Ps . aeruginosa SP1-induced spoilage of a proprietary formulation was found to be independent of growth in the formulation; rather it was attributed to the presence of a heat-labile extracellular spoilage-factor that was protease labile and possessed both lipase and polysorbate hydrolytic activity . Such spoilage potential was unique to one Ps . aeruginosa culture filtrate amongst five pseudomonads tested . SIGNIFICANCE AND IMPACT OF THE STUDY: The method is both rapid and reproducible, enables evaluation of the effects of route of contamination upon emulsion spoilage and has potential application in formulation development for cosmetic, pharmaceutical and food products. Protein Sci, 2004 May, 13(5), 1260 - 5 Epub 2004 Apr 09. Structure of fosfomycin resistance protein FosA from transposon Tn2921; Pakhomova S et al.; The crystal structure of fosfomycin resistance protein FosA from transposon Tn2921 has been established at a resolution of 2.5 A . The protein crystallized without bound Mn(II) and K+, ions crucial for efficient catalysis, providing a structure of the apo enzyme . The protein maintains the three-dimensional domain-swapped arrangement of the paired betaalphabetabetabeta-motifs observed in the genomically encoded homologous enzyme from Pseudomonas aeruginosa (PA1129) . The basic architecture of the active site is also maintained, despite the absence of the catalytically essential Mn(II) . However, the absence of K+, which has been shown to enhance enzymatic activity, appears to contribute to conformational heterogeneity in the K(+)-binding loops. Mikrobiologiia, 2004 Jan-Feb, 73(1), 45 - 50 {The requirements of Pseudomonas aeruginosa dissociants for carbon, nitrogen, and phosphorus}; Fursova PV et al.; Quantitative data on the nutritional requirements of microorganisms are necessary to predict the behavior of bacterial populations and to control their cultivation . The requirements of the R, S, and M dissociants of Pseudomonas aeruginosa for carbon, nitrogen, and phosphorus were derived from the results of 88 cultivation experiments . For each of the dissociants, we derived a coefficient that relates the optical density and the number of cells in the dissociant culture, determined the time when the cultures entered the stationary growth phase, studied cultural changes induced by transfer to the stationary phase, and determined what nutrients limit the growth of particular dissociants . The nutritional requirements of the dissociants are discussed in relation to our earlier data. Mikrobiologiia, 2004 Jan-Feb, 73(1), 37 - 44 {Effect of major nutrient elements on the growth and population homogeneity of the R, S and M dissociants of Pseudomonas aeruginosa and the glucose oxidation and fermentation pathways}; Mil'ko ES et al.; The population homogeneity of the stationary-phase monocultures of Pseudomonas aeruginosa dissociants was studied as a function of the initial content of major nutrient elements (C, N, and P) in the cultivation medium . The monocultures of the dissociants remained homogeneous during cultivation if the initial concentrations of the major nutrient elements were either sufficiently high or, conversely, very low, but became heterogeneous during cultivation in unbalanced (with respect to the major nutrient elements) media . At the initial concentration of nitrate in the medium equal to 0.07% or phosphate equal to 0.004-0.014%, the initially homogeneous population of R dissociant cultivated to the stationary growth phase turned out to contain 30-40% of S-type cells, whereas the initially homogeneous population of S dissociant was found to contain 50-80% of M-type cells . The population of M dissociant remained homogeneous throughout the cultivation period . R dissociant grew better at sufficiently high concentrations of glucose, nitrate, and phosphate in the medium, whereas M dissociant grew better when the initial concentrations of these nutrients were low . During the cultivation of R dissociant, the pH of the medium changed insignificantly, and the C/P ratio (the ratio of the carbon and phosphorus consumed during growth) was minimal (among the three dissociants), indicating that the R dissociant accomplishes the oxidative pathway of glucose metabolism . During the cultivation of the M dissociant, the pH of the medium dropped to 3.4-3.9, and the C/P ratio was maximal, indicating that this dissociant accomplishes the fermentative pathway of glucose metabolism . During the cultivation of the S dissociant, the pH of the medium and the C/P ratio exhibited variations, indicating that this dissociant triggers its pathways of glucose metabolism. Microbiology, 2004 Apr, 150(Pt 4), 967 - 78 Analysis of genetic polymorphisms affecting the four phospholipase C (plc) genes in Mycobacterium tuberculosis complex clinical isolates; Viana-Niero C et al.; The Mycobacterium tuberculosis genome contains four highly related genes which present significant similarity to Pseudomonas aeruginosa genes encoding phospholipase C enzymes . Three of these genes, plcA, plcB and plcC, are organized in tandem (locus plcABC) . The fourth gene, plcD, is located in a different region . This study investigates variations in plcABC and plcD genes in clinical isolates of M . tuberculosis, Mycobacterium africanum and 'Mycobacterium canettii' . Genetic polymorphisms were examined by PCR, Southern blot hybridization, sequence analysis and RT-PCR . Seven M . tuberculosis isolates contain insertions of IS6110 elements within plcA, plcC or plcD . In 19 of 25 M . tuberculosis isolates examined, genomic deletions were identified, resulting in loss of parts of genes or complete genes from the plcABC and/or plcD loci . Partial plcD deletion was observed in one M . africanum isolate . In each case, deletions were associated with the presence of a copy of the IS6110 element and in all occurrences IS6110 was transposed in the same orientation . A mechanism of deletion resulting from homologous recombination of two copies of IS6110 was recognized in a group of genetically related M . tuberculosis isolates . Five M . tuberculosis isolates presented major polymorphisms in the plcABC and plcD regions, along with loss of expression competence that affected all four plc genes . Phospholipase C is a well-known bacterial virulence factor . The precise role of phospholipase C in the pathogenicity of M . tuberculosis is unknown, but considering the potential importance that the plc genes may have in the virulence of the tubercle bacillus, the study of isolates cultured from patients with active tuberculosis bearing genetic variations affecting these genes may provide insights into the significance of phospholipase C enzymes for tuberculosis pathogenicity. Microbiology, 2004 Apr, 150(Pt 4), 831 - 41 Global regulation of quorum sensing and virulence by VqsR in Pseudomonas aeruginosa; Juhas M et al.; Pathogenesis of Pseudomonas aeruginosa is controlled to a major extent by the two quorum-sensing systems las and rhl . The previously uncharacterized gene PA2591 was identified as a major virulence regulator, vqsR, in the quorum-sensing hierarchy . vqsR is a member of the LuxR family and possesses a las box in its upstream region . Transposon inactivation of vqsR abrogated the production of N-acylhomoserine lactones and the secretion of exoproducts and diminished bacterial virulence for Caenorhabditis elegans . Cytotoxicity towards macrophages was not affected . vqsR mRNA was expressed more strongly in the presence of human serum and oxidative stress than under standard growth conditions . High-density oligonucleotide microarrays were used to compare the global expression profile of a wild-type strain and a vqsR mutant . One-hundred-and-fifty-one and 113 genes were significantly differentially expressed in the presence of H(2)O(2) and human serum, respectively . The disruption of vqsR repressed the expression of genes that are known to be promoted by quorum sensing and activated the expression of genes that are known to be repressed by quorum sensing . Moreover, the vqsR mutant harboured less mRNA transcript for the production of siderophores and membrane-bound elements of antibiotic resistance . The protein encoded by PA2591 regulates several traits of pathogenicity; hence, the name vqsR ('virulence and quorum-sensing regulator') was assigned to PA2591. Microbiology, 2004 Apr, 150(Pt 4), 795 - 803 Genetic characterization of pcpS, encoding the multifunctional phosphopantetheinyl transferase of Pseudomonas aeruginosa; Barekzi N et al.; Fatty acid synthases (primary metabolism), non-ribosomal peptide synthases and polyketide synthases (secondary metabolism) contain phosphopantetheinyl (Ppant)-dependent carrier proteins that must be made functionally active by transfer of the 4'-Ppant moiety from coenzyme A . These reactions are usually catalysed by dedicated Ppant transferases . Although rich in Ppant-dependent carrier proteins, it was previously shown that Pseudomonas aeruginosa possesses only one Ppant transferase, encoded by pcpS, which functions in both primary and secondary metabolism . Consistent with this notion are our findings that pcpS can genetically complement mutations in the Escherichia coli acpS and entD genes, encoding the apo-acyl carrier protein (ACP) synthase of fatty acid synthesis and a Ppant transferase of enterobactin synthesis, respectively . It also complements a Bacillus subtilis sfp mutation affecting a gene encoding a Ppant transferase essential for surfactin synthesis . A pcpS insertion mutant could only be constructed in a strain carrying the E . coli acpS gene on a chromosomally integrated element in trans, implying that the in vitro essentiality of pcpS is due to its requirement for activation of apo-ACP of fatty acid synthesis . The conditional pcpS mutant is non-fluorescent, does not produce pyoverdine and pyochelin, and does not grow in the presence of iron chelators . The data presented here for the first time confirm that PcpS plays an essential role in both fatty acid and siderophore metabolism. J Antimicrob Chemother, 2004 May, 53(5), 693 - 5 Epub 2004 Apr 08. Whither triclosan? Russell AD. Triclosan has activity against many, but not all, types of Gram-positive and Gram-negative bacteria . It is bacteriostatic at low concentrations, but higher concentrations are bactericidal . Pseudomonas aeruginosa is highly resistant, whereas methicillin-resistant Staphylococcus aureus strains are inhibited over a range of approximately 0.1-2 mg/L . Triclosan shows significant activity against some mycobacteria, but is not sporicidal . Its growth-inhibitory properties result from an inhibition of enoyl reductase, FabI . Membrane-destabilizing effects are likely to be responsible for bacterial inactivation by higher concentrations . Resistance can arise from mutations in, and/or overproduction of, FabI, impermeability or efflux . Whilst triclosan resistance in laboratory experiments may be associated with changes in antibiotic susceptibility, comprehensive environmental surveys have not demonstrated any association between triclosan usage and antibiotic resistance . Triclosan has several important uses, and the future aim must be to retain these applications whilst eliminating the more frivolous and unnecessary ones. J Indian Med Assoc, 2003 Aug, 101(8), 490 - 2 Nosocomial ocular infection--a prospective study; Das A et al.; Nosocomial infection of the eye is an uncommon complication, acquired during the course of hospital management . It may prolong the disease process or even destroy the eye . The overall incidence varies considerably by hospital services . To ascertain the various types of ocular infections and its responsible pathogens, a laboratory-based, nosocomial ocular infection control study was performed in a large referral hospital during a period of January 1997 to June 1999 . The study revealed 29 cases (0.08%) of culture proven ocular infections, out of 35,758 total admission during the period of one calendar year . Fifty-one eyes of 29 cases (22 bilateral) had nosocomial infection . Staphylococcus aureus (9), Staphylococcus epidermidis (8) and Pseudomonas aeruginosa (5), were the most frequent bacteria . Laboratory investigations helped in initiation and modification of specific antimicrobial therapy and also prognosis . Proper surveillance with the help of laboratory investigations has effective role in the management of nosocomial ocular infection. Mol Diagn, 2003, 7(3-4), 195 - 200 PCR-based detection of a cystic fibrosis epidemic strain of Pseudomonas Aeruginosa; Panagea S et al.; BACKGROUND: The Liverpool epidemic strain (LES) of Pseudomonas aeruginosa is widespread among patients with cystic fibrosis (CF) in specialist centers around Liverpool and elsewhere in the UK . This study evaluates a new diagnostic PCR assay based on a unique DNA sequence (PS21) of LES, for its identification of colonies directly from sputum . METHODS: One hundred and fifty-eight sputum samples from 92 patients were cultured and P . aeruginosa isolates were typed by PS21 PCR and pulsed-field gel electrophoresis (PFGE) . Subsequently, PS21 PCR was performed directly on sputum and the results were compared with culture, PFGE, and PS21 PCR typing . RESULTS: Eighty patients were colonized with P . aeruginosa, 63 by LES (79%) . There was 100% concordance between PS21 PCR on colonies and PFGE typing . The sensitivity and specificity of PS21 PCR directly on sputum was 98.2% and 93.6%, respectively . CONCLUSIONS: This study shows that PS21 PCR can be used for simple and rapid screening of LES colonization in CF patients. Appl Environ Microbiol, 2004 Apr, 70(4), 2105 - 9 Use of whole cells of Pseudomonas aeruginosa for synthesis of the antioxidant hydroxytyrosol via conversion of tyrosol; Allouche N et al.; For the first time, a soil bacterium, designated Pseudomonas aeruginosa, was isolated based on its ability to grow on tyrosol as a sole source of carbon and energy . During growth on tyrosol, this strain was capable of promoting the formation of a significant amount of hydroxytyrosol and trace quantities of parahydroxyphenyl acetic acid and 3,4-dihydroxyphenyl acetic acid . The products were confirmed by high-performance liquid chromatography and gas chromatography-mass spectrometry analyses . Using an optimized tyrosol concentration of 2 g liter(-1), the maximal hydroxytyrosol yield (80%) was achieved after a 7-h reaction in a growth experiment . To enhance the formation of hydroxytyrosol and prevent its degradation, a resting-cell method using P . aeruginosa was performed . The growth state of the culture utilized for biomass production, the carbon source on which the biomass was grown, the concentration of the biomass, and the amount of tyrosol that was treated were optimized . The optimal yield of hydroxytyrosol (96%) was obtained after a 7-h reaction using 4 g of tyrosol liter(-1) and 5 g of cells liter(-1) pregrown on tyrosol and harvested at the end of the exponential phase . This proposed procedure is an alternative approach to obtain hydroxytyrosol in an environmentally friendly way . In addition, the reaction is easy to perform and can be adapted to a bioreactor for industrial purposes. Philos Trans R Soc Lond B Biol Sci, 2004 Jan 29, 359(1441), 129 - 40 Hypervariability, suppressed recombination and the genetics of individuality; Olson MV et al.; We define 'genetic individuality' as intraspecies variation that has substantial heritability and involves traits that are sufficiently common that they can be observed in any modest-sized sampling of individuals . We propose that genetic individuality is largely shaped by the combinatory shuffling of a modest number of genes, each of which exists as a family of functionally and structurally diverged alleles . Unequivocal examples of such allele families are found at the O-antigen-biosynthetic locus in Pseudomonas aeruginosa and the human leucocyte antigen locus in humans . We examine characteristic features of these allele families and explore the possibility that genetic loci with similar characteristics can be recognized in a whole-genome scan of human genetic variation. Oncogene, 2004 Jun 17, 23(28), 4894 - 902 Bacterial N-acylhomoserine lactone-induced apoptosis in breast carcinoma cells correlated with down-modulation of STAT3; Li L et al.; Cell growth is promoted by mitogens and survival factors, which activate intracellular signalling pathways to control cell cycle progression and cellular integrity . Proliferation signals are transmitted through Ras and Rho family small G-proteins coupled to mitogen-activated protein kinase (MAPK) cascades, while survival signals are propagated by lipid-dependent kinases such as phosphatidylinositide 3-kinases (PI3Ks) and protein kinase B (Akt/PKB) . Recently, signal transducer and activator of transcription (STAT) proteins were identified as positive regulators of proliferation in a variety of cell types . Persistent activation of these pathways is associated with tumour cell growth, whereas their inhibition can halt proliferation and precipitate apoptotic cell death . The human pathogen Pseudomonas aeruginosa uses quorum-sensing signal molecules (QSSMs) to regulate virulence gene expression . QSSMs also suppress host immune responses although the mechanism of suppression is unknown . Here, we demonstrate that the QSSM N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) from P . aeruginosa blocks proliferation and induces apoptosis in human BC cell lines . Analyses of signalling events reveal that OdDHL has little or no effect on MAPK cascades, partially inhibits the Akt/PKB pathway and ablates STAT3 activity . Pharmacological inhibition of each pathway independently indicates that STAT3 activity is critical for BC cell proliferation and survival, while a constitutively active STAT3 confers resistance to OdDHL . These results support the notion of OdDHL as a bioactive molecule in eukaryotic systems and a paradigm for a novel class of antiproliferative compounds . J Microbiol Methods, 2004 May, 57(2), 163 - 73 Evaluation of disinfective potential of reactivated free chlorine in pooled tap water by electrolysis; Nakajima N et al.; Tap water is one of the causative factors of hospital infections . We examined the disinfective potential of electrolysis and mechanism of disinfection, and clarified the disinfective effect of electrolysis on tap water contaminated with bacteria, and discussed its clinical applications . Tap waters artificially contaminated with Pseudomonas aeruginosa, Escherichia coli, Legionella pneumophila, and Staphylococcus aureus could be sterilized by electrolysis at 20-30 mA for 5 min . A high-density suspension (10(6) CFU/ml) of a spore forming bacterium, Bacillus subtilis was not completely sterilized by electrolysis at 50 mA up to 30 min, but a low-density suspension (10(5) CFU/ml) was totally sterilized by electrolysis at 50 mA for 5 min . Electrolyzed P . aeruginosa changed morphologically, that is, there was bleb formation on the cell wall and irregular aggregation of cytoplasmic small granules . Moreover, cytoplasmic enzyme, nitrate reductase, was inactivated by the electrolysis . On the other hand, genomic DNA of the electrolyzed bacteria was not degenerated, therefore, their DNA polymerase activity was not completely inactivated . Consequently, the major agent in electrolysis for bactericidal action was considered to be free chlorine, and the possible bactericidal mechanism was by destruction of bacterial membranes, followed by the aggregation of peripheral cytoplasmic proteins . Electrolysis of tap water for both disinfecting contaminating bacteria and increasing the disinfectant capacity was considered effective with some limitations, particularly against high-density contamination by spore-forming bacteria . In clinical settings, electrolysis of tap water is considered effective to disinfect water for hand washing in operation theatres, and bathing water for immunocompromised hosts. Tidsskr Nor Laegeforen, 2004 Apr 1, 124(7), 933 - 5 {Tattooing dyes and pigments contaminated with bacteria}; Charnock C; BACKGROUND: Obtaining a tattoo has become increasingly popular in recent years . However, the degree to which tattooing represents a health risk in the form of infections is still a matter of debate . The aim of the present study was to investigate the microbial content of tattooing dyes and pigments (colourants) . MATERIAL AND METHODS: Microbes present in colourants used for tattooing were counted and identified using standard techniques and rapid identification systems . RESULTS: Seven of in total twelve colourants contributed by five studios contained bacteria . No fungi were found . Three solutions contained more than 10 8 bacteria/ml, chiefly aerobic, Gram-negative rods including Pseudomonas aeruginosa . No primary pathogens were found, however, the high colony counts found for some samples may represent infectious doses of a wide range of bacteria . INTERPRETATION: Although required by current regulations to be sterile, a number of colourants were highly contaminated with bacteria . The detection of bacteria in colourants necessitates a review of the studios' internal control procedures . In addition, the appropriate monitoring body should initiate testing of colourants in order to ascertain if these are contaminated at the time of purchase, or become so during use. J Bacteriol, 2004 Apr, 186(8), 2281 - 7 Pseudomonas aeruginosa autoinducer enters and functions in mammalian cells; Williams SC et al.; Quorum sensing (QS) is a cell density-dependent signaling mechanism used by many bacteria to control gene expression . Several recent reports indicate that the signaling molecules (autoinducers) that mediate QS in Pseudomonas aeruginosa may also modulate gene expression in host cells; however, the mechanisms are largely unknown . Here we show that two P . aeruginosa autoinducers, N-3-oxododecanoyl-homoserine lactone and N-butyryl-homoserine lactone, can both enter eukaryotic cells and activate artificial chimeric transcription factors based on their cognate transcriptional activators, LasR and RhlR, respectively . The autoinducers promoted nuclear localization of chimeric proteins containing the full LasR or RhlR coding region, and the LasR-based proteins were capable of activating transcription of a LasR-dependent luciferase gene . Responsiveness to autoinducer required the N-terminal autoinducer-binding domains of LasR and RhlR . Truncated proteins consisting of only the C-terminal helix-turn-helix DNA-binding domains of both proteins attached to a nuclear localization signal efficiently translocated to the nucleus in the absence of autoinducer, and truncated LasR-based proteins functioned as constitutively active transcription factors . Chimeric LasR proteins were only activated by their cognate autoinducer ligand and not by N-butyryl-L-homoserine lactone . These data provide evidence that autoinducer molecules from human pathogens can enter mammalian cells and suggest that autoinducers may influence gene expression in host cells by interacting with and activating as-yet-unidentified endogenous proteins. Zhonghua Shao Shang Za Zhi, 2004 Feb, 20(1), 6 - 9 {Investigation on the drug resistance of Pseudomonas aeruginosa in our burn ward in the past 11 years}; Dou Y et al.; OBJECTIVE: To analyze the use of antibiotics and the drug resistance of Pseudomonas aeruginosa in the burn ward of our hospital in the past 11 years, so as to optimize the use of antibiotics in the future . METHODS: Bacterial epidemiology during 1991-2001 in our burn ward was investigated . The change of the drug resistance of Pseudomonas aeruginosa was observed by defined daily dose (DDD) of antibiotics in adult patients and by the ranking of antibiotic administration days . RESULTS: (1) Staphylococcus aureus (10.53%-34.40%) and Pseudomonas aeruginosa (75.66%-11.47%) were dominant in our burn ward . (2) Predominant antibiotics used included Penicillin, Amikacin, Vancomycin, Imipenem and Ceftazidime . (3) There was increasing drug resistance of Pseudomonas aeruginosa to the following antibiotics ranking in following order: Piperacillin (41.57%-100.00%), Imipenem (36.36%-98.46%), Ceftazidime (23.46%-97.85%), Amikacin (13.16%-100.00%) and ciprofloxacin (6.90%-100.00%) . CONCLUSION: There was increasing drug resistance of Pseudomonas aeruginosa to all antibiotics, which might be related to antibiotic abuse. Lett Appl Microbiol, 2004, 38(5), 360 - 5 Methods for assaying cyanide in bacterial culture supernatant; Zlosnik JE et al.; AIMS: To find an easy, rapid and direct method for the quantitation of cyanide in a moderate number of bacterial culture supernatants . METHODS AND RESULTS: Culture supernatant from stationary phase cultures of Pseudomonas aeruginosa, grown in LB media, were analysed for cyanide content using the Merckoquant and Spectroquant cyanide detection kits as well as a cyanide ion-selective electrode (ISE) and a cyanide micro-ISE . The Merckoquant kit, designed for detection of low quantities of cyanide in water systems, proved not to be sufficiently reliable, providing poor comparison with previous assessments of cyanide levels in Ps . aeruginosa . The Spectroquant kit, and the two ISEs all provided very similar results, in agreement with previous data; however, it was the ISEs that fulfilled all the criteria for a rapid, direct test in a moderate number of samples . CONCLUSIONS: Cyanide ISEs can be used for easy assessment of the cyanide quantity in cultures grown in LB medium . Significance and Impact of the Study: The use of a cyanide ISE allows for an easy, direct and reproducible method for assaying cyanide in bacterial culture supernatant, which is of significant advantage over the currently accepted methods . This is especially important in an era of high-output genomic studies for assessing the phenotypic significance of data relating to the cyanide synthetic genes. J Biol Chem, 2004 Jun 11, 279(24), 25830 - 7 Epub 2004 Mar 30. The structure of the organic hydroperoxide resistance protein from Deinococcus radiodurans . Do conformational changes facilitate recycling of the redox disulfide? Meunier-Jamin C, Kapp U, Leonard GA, McSweeney S. The three-dimensional structure of the organic hydroperoxide resistance protein (OHRP) from Deinococcus radiodurans as determined using single crystal xray diffraction techniques is reported . Comparison of the structure with that obtained for OHRP from Pseudomonas aeruginosa reveals that the polypeptide chain of OHRPs can adopt two significantly different conformations ("in" and "out") in the region of the active site disulfide moiety . It is postulated that the closed configuration is consistent with efficient catalysis of the reduction of organic hydroperoxides, whereas the open form is required for enzyme recycling . Comparison of the structures of OHRP and that of the osmotically induced protein C (OsmC) from Mycoplasma pneumoniae shows that OHRPs and OsmCs are structurally homologous, perhaps indicating related functions for the two families of proteins. Antimicrob Agents Chemother, 2004 Apr, 48(4), 1406 - 9 Molecular analysis of metallo-beta-lactamase gene bla(SPM-1)-surrounding sequences from disseminated Pseudomonas aeruginosa isolates in Recife, Brazil; Poirel L et al.; The spread of clonally related carbapenem-resistant Pseudomonas aeruginosa producing the metallo-beta-lactamase SPM-1 was found in Recife, Brazil . Upstream of bla(SPM-1), a novel common region (CR4) was identified, comprising an open reading frame, orf495, whose product shares significant identity with putative recombinases, such as Orf513 . CR4 may be responsible for mobilization and expression of bla(SPM-1). Antimicrob Agents Chemother, 2004 Apr, 48(4), 1320 - 8 Enhancement of the mexAB-oprM efflux pump expression by a quorum-sensing autoinducer and its cancellation by a regulator, MexT, of the mexEF-oprN efflux pump operon in Pseudomonas aeruginosa; Maseda H et al.; nfxC-type cells of Pseudomonas aeruginosa that produce the MexEF-OprN efflux pump exhibit resistance to fluoroquinolones and chloramphenicol and hypersusceptibility to most classical beta-lactam antibiotics . We investigated the molecular mechanism of how the nfxC mutation causes beta-lactam hypersusceptibility . The MexAB-OprM extrusion pump transports and confers resistance to beta-lactam antibiotics . Interestingly, expression of the mexAB-oprM operon reached the highest level during the mid-stationary growth phase in both wild-type and nfxC-type mutant strains, suggesting that expression of the mexAB-oprM operon may be controlled by cell density-dependent regulation such as quorum sensing . This assumption was verified by demonstrating that exogenous addition of the quorum-sensing autoinducer N-butyryl-L-homoserine lactone (C4-HSL) enhanced the expression of MexAB-OprM, whereas N-(3-oxododecanoyl)-L-homoserine lactone had only a slight effect . Furthermore, this C4-HSL-mediated enhancement of mexAB-oprM expression was repressed by MexT, a positive regulator of the mexEF-oprN operon . It was concluded that beta-lactam hypersusceptibility in nfxC-type mutant cells is caused by MexT-mediated cancellation of C4-HSL-mediated enhancement of MexAB-OprM expression. Biosens Bioelectron, 2004 May 15, 19(10), 1237 - 44 Construction of a glucose sensor based on a screen-printed electrode and a novel mediator pyocyanin from Pseudomonas aeruginosa; Ohfuji K et al.; Pyocyanin is the blue phenazine pigment produced by Pseudomonas aeruginosa . Pyocyanin production using immobilized cells was investigated . The maximum production of pyocyanin was obtained using cells immobilized in kappa-carrageenan . Moreover, 0.01% PO4(3-), 0.2% Mg(2+), 0.001% Fe(2+), 1% glycerine, 0.8% leucine and 0.8% dl-alanine were also essential for pyocyanin production . Pyocyanin was purified by chloroform extraction and silica gel column chromatography . An amperometric biosensor system using a screen-printed electrode and pyocyanin as mediator were also developed for a more accurate determination of glucose concentration . Pyocyanin, which exists in the oxidated form, was reduced by the reaction between glucose oxidase and glucose . The reduced form was then converted back to the oxidized form by an oxidative reaction on the electrode . There was a linear relation ship between sensor output currents and glucose concentrations ranging from 1 to 20mM under the following conditions: -200 mV of the applied potential, pH 5.0, and 10 U of the immobilized enzyme . The coefficient of variation was below 3% (n = 5) for the glucose sensor. Can Respir J, 2004 Mar, 11(2), 151 - 5 Long term azithromycin therapy in cystic fibrosis patients: a study on drug levels and sputum properties; Baumann U et al.; BACKGROUND: Following reports on the treatment of diffuse panbronchiolitis (DPB), recent studies demonstrate that long term therapy with azithromycin (AZM) is effective in cystic fibrosis (CF) patients . However, the underlying mechanisms remain uncertain . Some macrolides, including AZM, display inhibition of virulence factors and other antipseudomonal effects at subinhibitory levels in vitro . OBJECTIVES: Drug doses used for CF and DPB therapy were investigated to determine whether they achieve corresponding sputum drug levels in CF patients in vivo . METHODS: In an open, prospective study, 14 CF patients with chronic Pseudomonas aeruginosa airway infection received 250 mg AZM either daily ('high dose') or twice weekly ('low dose') for 12 weeks . Viscoelasticity of sputum was assessed by magnetic microrheology . RESULTS: AZM accumulated in sputum by two orders of magnitude over a period of four weeks . In the following steady state, median AZM concentrations in sputum were 9.5 microg/mL (0.6 to 79.3 microg/mL, interquartiles 1.4 to 33.4 microg/mL) and 0.5 microg/mL (range less than 0.1 {below detection level} to 5.2 microg/mL, interquartiles 0.2 to 1.4 microg/mL) in the high and low dose groups, respectively . Viscoelasticity improved in all patients but one . CONCLUSIONS: The findings suggest that antipseudomonal activity has to be considered among the potential mechanisms of macrolide therapy . Further, viscoelasticity may be a valuable parameter in future clinical trials. J Mol Microbiol Biotechnol, 2003, 6(2), 88 - 100 The role of regulators in the expression of quorum-sensing signals in Pseudomonas aeruginosa; Fagerlind MG et al.; Quorum-sensing systems provide Pseudomonas aeruginosa with a sensitive regulatory mechanism that allows for the induction of several phenotypic genes in a cell density fashion . In this work, a mathematical model of the acylated homoserine lactones regulatory network system in P . aeruginosa has been developed . It is the first integrated model to consider both quorum-sensing systems . The model has allowed us to disentangle the complex behavior exhibited by the system as the concentration of extracellular OdDHL is increased . At either low or high levels of extracellular OdDHL, the bacterium remains in an uninduced or induced state, respectively . At moderate levels, the behavior is characterized by several states . Here, the bacteria can switch suddenly from an uninduced to an induced phenotype in response to small changes in the concentration of extracellular OdDHL . Additionally, we have been able to address the roles of RsaL and Vfr as regulators of the quorum-sensing system . An important result from this analysis suggests that RsaL will increase the concentration of extracellular OdDHL required to induce the system, and it is a key regulator of the inhibition of the quorum-sensing system under low cell densities . Most importantly, our results suggest that Vfr has strong regulatory effects on the system as an increased affinity between the LasR/OdDHL complex, and the lasR promoter leads to significant qualitative changes in induction patterns . We also show experimental data that demonstrate that Vfr is required for signal production in the early phase of growth, but that in the latter stages of growth, the vfr mutant is able to synthesize wild-type levels of signal . Di Yi Jun Yi Da Xue Xue Bao, 2004 Mar, 24(3), 303 - 5 {Detection of oprI gene of Pseudomonas aeruginosa by reverse dot-blot hybridization}; Fan HZ et al.; OBJECTIVE: To establish a rapid method for detecting Pseudomonas aeruginosa at the early stage of infection . METHODS: Specific primers were designed according to oprI gene sequence of Pseudomonas aeruginosa, and the specific probe was synthesized by PCR . After photosensitive biotin labeling of the bacterial DNA, reverse dot-blot hybridization was used to detect Pseudomonas aeruginosa . RESULTS: The probe synthesized was highly specific to Pseudomonas aeruginosa without cross reaction with other bacteria, viruses or fungi . The method was capable of detecting 100 ng bacteria DNA . CONCLUSION: Reverse dot-blot hybridization possesses the merits of speediness and specificity in the detection of Pseudomonas aeruginosa in the early stage of infection. Vaccine, 2004 Feb 17, 22(7), 840 - 7 Recombinant OprF-OprI as a vaccine against Pseudomonas aeruginosa infections; Baumann U et al.; A vaccine against Pseudomonas aeruginosa based on recombinant outer membranes has been developed . After intramuscularly injecting into patients with severe burns, antibodies against P . aeruginosa were induced . Vaccination was well tolerated . Intranasal application of the vaccine into volunteers, induced specific s-IgA antibodies . We conclude that the newly developed vaccine may be suitable for protection of the main risk groups of P . aeruginosa infections . In particular, for the protection of burn patients and patients with cystic fibrosis. Vaccine, 2004 Feb 17, 22(7), 831 - 9 Pseudomonas immunotherapy: a historical overview; Holder IA; The historic development of vaccines to be used as immunotherapy for Pseudomonas aeruginosa infections, in various patient populations, is reviewed . Commentary is offered concerning the relevance of each approach in light of our current understanding of the pathological process of these infections. Respir Res . 2004 Feb 12;5(1):1. TLR4 signaling is essential for survival in acute lung injury induced by virulent Pseudomonas aeruginosa secreting type III secretory toxins; Faure K et al.; BACKGROUND: The relative contributions of the cytotoxic phenotype of P . aeruginosa expressing type III secretory toxins and an immunocompromised condition lacking normal Toll-like receptor 4 (TLR4) signaling in the pathogenesis of acute lung injury and sepsis were evaluated in a mouse model for Pseudomonas aeruginosa pneumonia . By using lipopolysaccharide-resistant C3H/HeJ mice missing normal TLR4 signaling due to a mutation on the tlr4 gene, we evaluated how TLR4 signaling modulates the pneumonia caused by cytotoxic P . aeruginosa expressing type III secretory toxins . METHODS: We infected C3H/HeJ or C3H/FeJ mice with three different doses of either a cytotoxic P . aeruginosa strain (wild type PA103) or its non-cytotoxic isogenic mutant missing the type III secretory toxins (PA103DeltaUT) . Survival of the infected mice was evaluated, and the severity of acute lung injury quantified by measuring alveolar epithelial permeability as an index of acute epithelial injury and the water to dry weight ratios of lung homogenates as an index of lung edema . Bacteriological analysis and cytokine assays were performed in the infected mice . RESULTS: Development of acute lung injury and sepsis was observed in all mouse strains when the cytotoxic P . aeruginosa strain but not the non-cytotoxic strain was instilled in the airspaces of the mice . Only C3H/HeJ mice had severe bacteremia and high mortality when a low dose of the cytotoxic P . aeruginosa strain was instilled in their lungs . CONCLUSION: The cytotoxic phenotype of P . aeruginosa is the critical factor causing acute lung injury and sepsis in infected hosts . When the P . aeruginosa is a cytotoxic strain, the TLR4 signaling system is essential to clear the bacteria to prevent lethal lung injury and bacteremia. Infect Immun, 2004 Apr, 72(4), 2045 - 51 Role for cystic fibrosis transmembrane conductance regulator protein in a glutathione response to bronchopulmonary pseudomonas infection; Day BJ et al.; The lung maintains an elevated level of glutathione (GSH) in epithelial lining fluid (ELF) compared to serum . The mechanism(s) by which the lung maintains high levels of ELF GSH and factors that modulate them are largely unexplored . We hypothesized that lung cystic fibrosis transmembrane conductance regulator protein (CFTR) modulates GSH efflux in response to extracellular stress, which occurs with lung infections . Mice were challenged intratracheally with Pseudomonas aeruginosa, and on the third day of infection bronchoalveolar lavage fluid was obtained and analyzed for cytokines and antioxidants . Lung tissue antioxidants and enzyme activities were also assessed . P . aeruginosa lung infection increased levels of inflammatory cytokines and neutrophils in the ELF . This corresponded with a marked threefold increase in GSH and a twofold increase in urate levels in the ELF of P . aeruginosa-infected wild-type mice . A twofold increase in urate levels was also observed among lung tissue antioxidants of P . aeruginosa-infected wild-type mice . There were no changes in markers of lung oxidative stress associated with the P . aeruginosa lung infection . In contrast with wild-type mice, the CFTR knockout mice lacked a significant increase in ELF GSH when challenged with P . aeruginosa, and this correlated with a decrease in the ratio of reduced to oxidized GSH in the ELF, a marker of oxidative stress . These data would suggest that the lung adapts to infectious agents with elevated ELF GSH and urate . Individuals with lung diseases associated with altered antioxidant transport, such as cystic fibrosis, might lack the ability to adapt to the infection and present with a more severe inflammatory response. Invest Ophthalmol Vis Sci, 2004 Apr, 45(4), 1182 - 7 Murine ocular heparanase expression before and during infection with Pseudomonas aeruginosa; Berk RS et al.; PURPOSE: To demonstrate the constitutive expression and regulation of heparanase (heparan sulfate endoglycosidase) in the normal mouse eye and in mice intracorneally infected with Pseudomonas aeruginosa . METHODS: Naive (unimmunized) and immunized C57BL/6J mice were infected with P . aeruginosa, and corneal heparanase gene and protein expression were detected by semiquantitative RT-PCR and immunoblot analysis . Immunohistochemistry was also applied to characterize corneal heparanase in naive mice . RESULTS: Heparanase mRNA and protein expression were detected in uninfected corneas of C57BL/6J mice . Immunohistochemical studies indicated heparanase protein expression was primarily in the corneal epithelium before corneal infection and was also in the corneal stroma after infection . Immunohistochemical studies of uninfected and infected whole eyes of naive mice indicated heparanase protein expression in most layers of the retina, but the expression did not appear to be upregulated during corneal infection . Staining was most intense in the inner photoreceptor layer of the retina . CONCLUSIONS: Heparanase was constitutively expressed in both the corneal epithelium and several retinal layers before intracorneal infection with P . aeruginosa . Temporal upregulation of corneal heparanase protein expression was detected in naive mice during infection, most likely due to heparanase positive infiltrating cells, but the protein was not upregulated in corneas from immunized mice because they had a lower inflammatory response, associated with the restoration of corneal clarity . There did not appear to be temporal upregulation of heparanase expression in the retina of infected mice, as determined by immunohistochemistry. Curr Opin Microbiol, 2004 Feb, 7(1), 39 - 44 Analysis of regulatory networks in Pseudomonas aeruginosa by genomewide transcriptional profiling; Goodman AL et al.; Transcriptional profiling using DNA microarrays has proved to be a valuable tool for dissecting bacterial adaptation to various environments, including human hosts . Analysis of genomes and transcriptomes of Pseudomonas aeruginosa shows that this bacterium possesses and expresses a core set of genes, including virulence factors, which allow it to thrive in a range of environments . Transcriptional regulators previously thought to control single virulence traits are now shown to regulate complex global signaling networks . Microarray-based research has led to the discovery of upstream regulators and downstream components of these pathways, as well as probed the response to antibiotics, environmental stresses and other bacteria . Independent studies have highlighted the role of media composition, the makeup of the physical environment and experimental methods in the outcome of microarray analyses . A compilation of all the published data clearly shows transcriptional regulation of genes in all functional classes . Under conditions examined to date, slightly more than a quarter of the genome is regulated, suggesting that P . aeruginosa may use much of its genome for conditions unexplored in the laboratory. J Cataract Refract Surg, 2004 Feb, 30(2), 457 - 63 Folding procedure for acrylic intraocular lenses; Mencucci R et al.; PURPOSE: To compare in vitro the effect of 2 standard methods of folding acrylic intraocular lenses (IOLs) on surface characteristics and bacterial adhesion . SETTING: Eye Clinic and Department of Health-Microbiology Unit, University of Florence, Florence, Italy . METHODS: To evaluate the effect of folding, 2 types of acrylic IOLs were not folded or folded with a forceps or an injector and then processed for scanning electron microscopy (SEM) examination . Bacterial adhesion was assessed using an ocular isolate of Pseudomonas aeruginosa . Nonfolded and folded IOLs were placed in test tubes containing the bacterial suspension for direct counting of viable adherent bacteria and for SEM . RESULTS: The injector-folded IOLs did not show major alterations on the surface; 5 of the 9 forceps-folded IOLs showed marks or scratches in the profile of the optic . The mean number of viable adherent bacteria per area of IOL optic was 1082 (95% confidence interval {CI}, 835-1330) in forceps-folded IOLs, 366 (95% CI, 192-359) in injector-folded IOLs, and 206 (95% CI, 123-289) in nonfold