Res Microbiol, 1997 Jan, 148(1), 37 - 43 Oxygen-dependent upregulation of transcription of alginate genes algA, algC and algD in Pseudomonas aeruginosa; Leitao JH et al.; The mRNA levels of algA, algC and algD genes increased, coordinately, in cells of the highly mucoid Pseudomonas aeruginosa 8821M grown under increasing dissolved oxygen tensions (DOT) of up to 70% of air saturation . These genes encode the bifunctional protein with phosphomannose isomerase (PMI) and GDP-mannose pyrophosphorylase (GMP) activities (algA), the phosphomannomutase (PMM) (algC) and the GDP-mannose dehydrogenase (GMD) (algD) . These four enzyme activities are necessary for the synthesis of GDP-mannuronic acid, which is the activated sugar precursor for alginate polymerization . For growth-limiting DOT--lower than 10% of air saturation--the increase in mRNA levels of algA, algC and algD with oxygen concentration was accompanied by a strong increase in the activity of the encoded enzymes and the consequent increase in alginate synthesis . However, and despite the upregulation of alginate gene transcription by DOT above 10% of air saturation, the activities of the encoded enzymes either maintained (GMP and GMD) or decreased (PMI and PMM) their levels at high oxygen tensions, leading to a slight decrease in alginate synthesis . This has previously been attributed to the oxidative inactivation of alginate enzymes, particularly of PMM and PMI activities. Med Microbiol Immunol (Berl), 1997 Oct, 186(2-3), 93 - 9 Direct sputum analysis of Pseudomonas aeruginosa macrorestriction fragment genotypes in patients with cystic fibrosis; Breitenstein S et al.; The distribution of bacterial populations in the airways of 13 patients with cystic fibrosis who were colonized for 6-23 years with Pseudomonas aeruginosa was investigated by genotyping of bacterial chromosomes directly isolated from 21 sputa . After removal of host material from sputum by hypotonic cell lysis and repetitive washing and centrifugation steps, agarose-embedded bacterial cells were lysed, residual eukaryotic DNA separated by field inversion gel electrophoresis, and the purified bacterial chromosomes subjected to macrorestriction fragment pattern and Southern analyses . Bacterial populations consisted of a single P . aeruginosa clone in 17 sputa, of which more than one clonal variant was apparent in two SpeI fragment fingerprints . Two clones of P . aeruginosa and another species co-existed in four samples . Genomically homogeneous populations of P . aeruginosa are characteristic for chronically colonized lungs in most cases of cystic fibrosis. Dermatology, 1997, 195 Suppl 2, 36 - 41 Antiseptic efficacy of disinfecting solutions in suspension test in vitro against methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli in pressure sore wounds after spinal cord injury; Michel D et al.; In pressure sore wounds after spinal cord injury, methicillin-resistant Staphylococcus aureus can be detected in 2% of the cases . The elimination of the germ is the aim of the treatment . Pressure sore wounds are an often found complication after spinal cord injury . For local treatment five commercially available antiseptics for the skin and mucous membrane were tested in vitro . The method used is a modified qualitative and quantitative suspension test . The antiseptics were tested without and with addition of 5% albumin in order to simulate the conditions of the wound in vivo . The results show a superior efficacy of the povidone-iodine preparations . Betadine, probably due to the higher concentration, is more efficacious than Braunol; chlorhexidine is sufficiently efficacious without the addition of albumin . These results still have to be confirmed by in vivo studies. Clin Infect Dis, 1997 Nov, 25(5), 1094 - 8 Imipenem-resistant Pseudomonas aeruginosa: risk factors and antibiotic susceptibility patterns; Troillet N et al.; Potential risk factors for the detection of imipenem-resistant Pseudomonas aeruginosa in hospitalized patients were assessed by a case-control study . Forty patients whose first P . aeruginosa isolate was resistant or intermediate to imipenem were more likely than 387 controls to have received imipenem (odds ratio {OR} = 16.9; P < .0001) and to have undergone organ transplantation (OR = 3.9; P = .008) . No significant difference was found for treatments with other antibiotics, other underlying diseases, demographic characteristics, different exposures to the hospital environment, or the culture site . Imipenem-resistant P . aeruginosa isolates were more likely to be resistant to other common antipseudomonal agents than were imipenem-susceptible isolates . It is concluded that treatment with imipenem, but not with other beta-lactam drugs, is a major risk factor for the detection of imipenem-resistant P . aeruginosa in hospitalized patients, that these organisms may relatively often be resistant to other antipseudomonal agents, and that the hospital environment per se might not play a major role in their epidemiology. Mol Microbiol, 1997 Nov, 26(3), 607 - 18 Mammalian heterotrimeric G-protein-like proteins in mycobacteria: implications for cell signalling and survival in eukaryotic host cells; Shankar S et al.; Mammalian heterotrimeric GTP-binding protein (G proteins) are involved in transmembrane signalling that couples a number of receptors to effectors mediating various physiological processes in mammalian cells . We demonstrate that bacterial proteins such as a Ras-like protein from Pseudomonas aeruginosa or a 65 kDa protein from Mycobacterium smegmatis can form complexes with human or yeast nucleoside diphosphate kinase (Ndk) to modulate their nucleoside triphosphate synthesizing specificity to GTP or UTP . In addition, we demonstrate that bacteria such as M . smegmatis or Mycobacterium tuberculosis harbour proteins that cross react with antibodies against the alpha-, beta- or the gamma-subunits of heterotrimeric G proteins . Such antibodies also after the GTP synthesizing ability of specific membrane fractions isolated from glycerol gradients of such cells, suggesting that a membrane-associated Ndk-G-protein homologue complex is responsible for part of GTP synthesis in these bacteria . Indeed, purified Ndk from human erythrocytes and M . tuberculosis showed extensive complex formation with the purified mammalian alpha- and beta-G-protein subunits and allowed specific GTP synthesis, suggesting that such complexes may participate in transmembrane signalling in the eukaryotic host . We have purified the alpha-, beta- and gamma-subunit homologues from M . tuberculosis and we present their internal amino acid sequences as well as their putative homologies with mammalian subunits and the localization of their genes on the M . tuberculosis genome . Using oligonucleotide probes from the conserved regions of the alpha- and gamma-subunit of M . tuberculosis G-protein homologue, we demonstrate hybridization of these probes with the genomic digest of M . tuberculosis H37Rv but not with that of M . smegmatis, suggesting that M . smegmatis might lack the genes present in M . tuberculosis H37Rv . Interestingly, the avirulent strain H37Ra showed weak hybridization with these two probes, suggesting that these genes might have been deleted in the avirulent strain or are present in limited copy numbers as opposed to those in the virulent strain H37Rv. Monaldi Arch Chest Dis, 1997 Aug, 52(4), 363 - 6 Cystic fibrosis respiratory infections: interactions between bacteria and host defence; Doring G; In cystic fibrosis, impaired mucociliary clearance leads to chronic endobronchial bacterial infection, mostly caused by Pseudomonas aeruginosa . In the early stage of infection, the pathogen produces several extracellular protein toxins which may contribute to its multifactorial virulence before specific antibodies are produced . P . aeruginosa successfully resists phagocytosis by neutrophils, which dominate the local inflammatory response, by switching from a nonmucoid variant to a mucoid phenotype . Chronic infection and inflammation are characterized by neutrophil-released proteinases which may provide favourable growth conditions for the bacterial opportunist . Aerosol therapy with serine proteinase inhibitors is being investigated in cystic fibrosis. J Bacteriol, 1997 Dec, 179(24), 7875 - 81 Inner membrane efflux components are responsible for beta-lactam specificity of multidrug efflux pumps in Pseudomonas aeruginosa; Srikumar R et al.; A major feature of the MexAB-OprM multidrug efflux pump which distinguishes it from the MexCD-OprJ and MexEF-OprN multidrug efflux systems in Pseudomonas aeruginosa is its ability to export a wide variety of beta-lactam antibiotics . Given the periplasmic location of their targets it is feasible that beta-lactams exit the cell via the outer membrane OprM without interaction with MexA and MexB, though the latter appear to be necessary for OprM function . To test this, chimeric MexAB-OprJ and MexCD-OprM efflux pumps were reconstituted in delta mexCD delta oprM and delta mexAB delta oprJ strains, respectively, and the influence of the exchange of outer membrane components on substrate (i.e., beta-lactam) specificity was assessed . Both chimeric pumps were active in antibiotic efflux, as evidenced by their contributions to resistance to a variety of antimicrobial agents, although there was no change in resistance profiles relative to the native pumps, indicating that OprM is not the determining factor for the beta-lactam specificity of MexAB-OprM . Thus, one or both of inner membrane-associated proteins MexA and MexB are responsible for drug recognition, including recognition of beta-lactams. J Bacteriol, 1997 Dec, 179(24), 7834 - 42 Regulation of ornithine utilization in Pseudomonas aeruginosa (PAO1) is mediated by a transcriptional regulator, OruR; Hebert MD et al.; We have used transpositional mutagenesis of a proline auxotroph (PAO951) to isolate an ornithine utilization (oru) mutant of Pseudomonas aeruginosa (PAO951-4) that was unable to use ornithine efficiently as the sole carbon and nitrogen source . DNA sequence analysis of the inactivated locus confirmed that the transposon had inserted into a locus whose product demonstrated significant primary sequence homology to members of the AraC family of transcriptional activators . DNA mobility shift assays affirmed this potential regulatory function and indicated that the inactivated gene encodes a transcriptional regulator, which has been designated OruR . In trying to define the ornithine utilization phenotype further, a similar inactivation was engineered in the wild-type strain, PAO1 . The resulting isolate (PAO1R4) was totally unable to use ornithine as the sole carbon source . Despite the intensified phenotype, this isolate failed to demonstrate significant changes in any of the catabolic or anabolic enzymes that are known to be subject to regulation by the presence of either ornithine or arginine . It did, however, show modified levels of an enzyme, ornithine acetyltransferase (OAcT), that was previously thought to have merely an anaplerotic activity . Definition of this oruR locus and its effects upon OAcT activity provide evidence that control of ornithine levels in P . aeruginosa may have a significant impact upon how the cell is able to monitor and regulate the use of arginine and glutamate as sources of either carbon or nitrogen. Proc Natl Acad Sci U S A, 1997 Nov 25, 94(24), 13245 - 50 Use of model plant hosts to identify Pseudomonas aeruginosa virulence factors; Rahme LG et al.; We used plants as an in vivo pathogenesis model for the identification of virulence factors of the human opportunistic pathogen Pseudomonas aeruginosa . Nine of nine TnphoA mutant derivatives of P . aeruginosa strain UCBPP-PA14 that were identified in a plant leaf assay for less pathogenic mutants also exhibited significantly reduced pathogenicity in a burned mouse pathogenicity model, suggesting that P . aeruginosa utilizes common strategies to infect both hosts . Seven of these nine mutants contain TnphoA insertions in previously unknown genes . These results demonstrate that an alternative nonvertebrate host of a human bacterial pathogen can be used in an in vivo high throughput screen to identify novel bacterial virulence factors involved in mammalian pathogenesis. JAMA, 1997 Dec 10, 278(22), 1924 - 30 Immunologic aspects of lung diseases and cystic fibrosis; Greenberger PA; Immunologic lung disorders are accompanied by an array of laboratory abnormalities, some of which contribute to disease pathogenesis . Allergic bronchopulmonary aspergillosis, which complicates asthma and cystic fibrosis, causes mucous plugging of airways, eosinophilic pneumonia, and bronchiolitis obliterans . Aspergillus fumigatus, growing saprophytically in bronchial mucus, is responsible for most cases, and prednisone, not antifungal agents, is the drug of choice because it controls the immunologic responses of the lung . In cystic fibrosis, epithelial surface fluid from the lung does not kill Pseudomonas aeruginosa, in part because antibodies to P aeruginosa are plentiful but ineffective in opsonizing bacteria . Neutrophil-derived elastase cleaves immunoglobulins and digests the C3b receptor on neutrophils, which limits phagocytosis of pathogens . In helminth infections and infestations, pulmonary and peripheral blood eosinophilia can be accompanied by increases in total and antiparasite IgE concentrations and generate T(H)2 CD4+ T-lymphocyte responses . Understanding the immunologic abnormalities of lung disorders may lead to more effective therapies. Rinsho Byori, 1997 Nov, 45(11), 1091 - 7 {Analysis of genome-type, serovar and antibiotic susceptibility of Pseudomonas aeruginosa isolated in Beijing Hospital China in 1991 to 1993}; Chen G et al.; We analyzed the in vitro antibiotic susceptibility pattern and serovar for 192 strains of Pseudomonas aeruginosa isolated at Beijing Hospital(China) from October 1991 to October 1993 . The frequency of resistant strains was high, more than 15%, for ceftazidime, cefsulodin, cefoperazone, aztreonam, gentamicin, tobramycin, tosufloxacin, ofloxacin and fosfomycin . The incidence of resistants against piperacillin and imipenem was significantly low . Among the 192 strains, 16 were designated as being multi-drug resistant strains(i.e.; resistant to more than 8 drugs out of 11 drugs), and all of the multi-drug resistant strains were isolated from inpatients . Predominant serovar of 192 strains were 60(31.3%) for G, 28(14.7%) for E, and 24(12.5%) for I . Multi-drug resistant strains have no characteristic serovar . Restriction enzyme SpeI digestion analysis(using pulse field electrophoresis) of P . aeruginosa-genome yielded several common patterns, and was shown to be useful for tracing the route of nosocomial infection . Further, isolates with closely related genome type, in which the size of one digested band was different, showed a different minimum inhibitory concentration of fosfomycin in one genome type or new quinolones in the other genome type . Analysis of genome type and antibiotic susceptibility pattern may exhibit the antibiotic resistant gene. Can J Microbiol, 1997 Oct, 43(10), 981 - 5 Functional analysis of sigma-70 consensus promoters in Pseudomonas aeruginosa and Escherichia coli; McLean BW et al.; A series of synthetic promoters, based upon the Escherichia coli sigma 70 consensus promoter sequence, was constructed upstream of the lacZ reporter gene in the modified broad-host-range vector pQF52 . The role of the intervening spacer region in gene expression in Pseudomonas aeruginosa and E . coli was studied by insertions and deletions within this region . In P . aeruginosa and E . coli the patterns of gene expression were identical with maximum beta-galactosidase activity being measured from promoters possessing 19 bp in their intervening regions, presumably as a result of impeded promoter clearance with the consensus 17-bp promoter . In P . aeruginosa a second occurrence of enhanced activity, which could not be attributed to the involvement of the alternative sigma factor RpoN (sigma 54), was evident with the promoter having a 16-bp spacer. Cornea, 1997 Nov, 16(6), 662 - 5 The antibacterial activity of topical anesthetics; Mullin GS et al.; PURPOSE: Topical anesthetics are commonly used prior to obtaining bacterial cultures in ulcerative keratitis . We performed an in vitro study designed to test both the bacteriostatic and bactericidal effects of commercially available preserved topical anesthetic agents . METHODS: Proparacaine, tetracaine, cocaine, and sterile water solutions were applied to filter paper disks, which were then placed on Mueller-Hinton agar plates that had previously been inoculated with known quantities of Pseudomonas aeruginosa and Staphylococcus aureus . After 24 h of incubation, zones of inhibition were measured and recorded . RESULTS: Proparacaine strongly inhibited the growth of S . aureus at all concentrations (0.5%, 0.25%, 0.125%) and inhibited growth of P . aeruginosa at 0.5% and 0.25% but not at 0.125% concentration . Tetracaine also inhibited S . aureus at 0.5% and inhibited P . aeruginosa at 0.5% and 0.25% concentrations . Cocaine exhibited no inhibition of S . aureus and exhibited mild inhibition of P . aeruginosa growth only at the 4% concentration . CONCLUSIONS: The in vitro antibacterial effect of topical anesthetics suggests one possible reason why bacterial culture yields in clinical ulcerative keratitis are suboptimal . We propose that clinicians consider the use of a 1% or 2% cocaine solution instead of standard commercial topical anesthetics in the management of individual cases of ulcerative keratitis and in future clinical bacterial keratitis studies. Nippon Kyobu Geka Gakkai Zasshi, 1997 Oct, 45(10), 1751 - 4 {Successful two-stage approach to treating excessive hemorrhage from pulmonary arterial stump in post-lobectomy bronchopleural fistula}; Kanda A et al.; A 62-year-old man underwent right lower lobectomy for adenocarcinoma (pT2N0M0) and nine days later, a bronchopleural fistula with empyema was evident . Six weeks following the lobectomy, excessive hemorrhage from the site of chest drainage and hemoptysis were noted . The bleeding and empyema were controlled by a two-stage approach . Anterior transpericardial approach was first made through the median sternotomy to clamp the right main pulmonary artery and then postero-lateral thoracotomy was conducted for the bronchopleural fistula with empyema . The right bronchial stump was covered with a pedicled muscle flap and pseudomonas aeruginosa, always positive in drainage effusion, consequently disappeared . The patient was discharged with a closed bronchus 4 months following the operation. Infect Immun, 1997 Dec, 65(12), 5176 - 83 Altered cytokine production by cystic fibrosis tracheal gland serous cells; Kammouni W et al.; Human submucosal tracheal glands are now believed to play a major role in the physiopathology of cystic fibrosis (CF) . We successfully developed techniques for culturing human tracheal gland serous cells from normal individuals (HTGS cells) and from CF patients (CF-HTGS cells) and have shown that the cultured cells have retained most of their in vivo epithelial and secretory characteristics . In order to determine to what extent the serous cells may participate in the lung defense against infection, we examined the effects of the lipopolysaccharide (LPS) of Pseudomonas aeruginosa on HTGS and CF-HTGS cells, with special reference to tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and IL-8 secretion . HTGS cells showed a daily basal secretion of IL-6 (1.68 +/- 0.14 ng/10(6) cells) and IL-8 (9.6 +/- 1.3 ng/10(6) cells) and no constitutive secretion of TNF-alpha . Treatment with P . aeruginosa LPS resulted in a significant increase in the basal production of IL-6 (increase of 200% +/- 12%) and IL-8 (525% +/- 40%) as well as a rapid production of TNF-alpha (250 +/- 38 pg/10(6) cells) . The LPS-induced secretion of IL-6 and IL-8, but not that of TNF-alpha, was inhibited by glucocorticoids . CF-HTGS cells showed a much higher basal secretion of IL-6 (13.2 +/- 0.5 ng/10(6) cells) and IL-8 (45.6 +/- 7.2 ng/10(6) cells) than normal cells . Treatment with the LPS of P . aeruginosa induced increased production of IL-6 (increase of 100% +/- 8%) and IL-8 (55% +/- 18%) but did not induce the secretion of TNF-alpha . Neither intracellular TNF-alpha nor TNF-alpha transcripts were found in CF-HTGS cells, whereas they were found in normal HTGS cells . In addition, dexamethasone was found to stimulate IL-6 and IL-8 secretion (in the presence or absence of LPS) but did not induce any secretion of TNF-alpha . All these data indicate that HTGS cells are responsive to P . aeruginosa LPS, which results in an increased secretion of IL-6, IL-8, and TNF-alpha, the secretion of which appeared to be impaired in CF-HTGS cells. J Bacteriol, 1997 Dec, 179(23), 7298 - 305 Transcriptional regulation of type 4 pilin genes and the site-specific recombinase gene, piv, in Moraxella lacunata and Moraxella bovis; Heinrich DW et al.; Moraxella lacunata and Moraxella bovis use type 4 pili to adhere to epithelial tissues of the cornea and conjunctiva . Primer extension analyses were used to map the transcriptional start sites for the genes encoding the major pilin subunits (tfpQ/I) and the DNA invertase (piv), which determines pilin type expression . tfpQ/I transcription starts at a sigma54-dependent promoter (tfpQ/Ip2) and, under certain growth conditions, this transcription is accompanied by weaker upstream transcription that starts at a potential sigma70-dependent promoter (tfpQ/Ip1) . piv is expressed in both M . lacunata and M . bovis from a putative sigma70-dependent promoter (pivp) under all conditions assayed . Sigma54-dependent promoters require activators in order to initiate transcription; therefore, it is likely that tfpQ/Ip2 is also regulated by an activator in Moraxella . Primer extension assays with RNA isolated from Escherichia coli containing the subcloned pilin inversion region from M . lacunata showed that pivp is used for the expression of piv; however, tfpQ/Ip2 is not used for the transcription of tfpQ/I . Transcription from tfpQ/Ip2 was activated in E . coli when the sensor (PilS) and response regulator (PilR) proteins of type 4 pilin transcription in Pseudomonas aeruginosa were expressed from a plasmid . These results suggest that the expression of the type 4 pilin in M . lacunata and M . bovis is regulated not only by a site-specific DNA inversion system but also by a regulatory system which is functionally analogous to the PilS-PilR two-component system of P . aeruginosa. J Bacteriol, 1997 Dec, 179(23), 7280 - 90 Cloning and characterization of the aru genes encoding enzymes of the catabolic arginine succinyltransferase pathway in Pseudomonas aeruginosa; Itoh Y; The arginine succinyltransferase (AST) pathway is the major arginine and ornithine utilization (aru) pathway under aerobic conditions in Pseudomonas aeruginosa . A 26-kb DNA fragment of the P . aeruginosa PAO1 chromosome carrying the regulatory argR gene and the aru structural gene cluster was cloned . Complementation tests and nucleotide sequence data established the locations of the argR, aruC, aruF, aruG, aruD, aruB, and aruE genes, in that order . The aruR, aruC, aruD, aruB, and aruE genes specify the ArgR regulatory protein, N2-succinylornithine 5-aminotransferase, N-succinylglutamate 5-semialdehyde dehydrogenase, N2-succinylarginine dihydrolase, and N-succinylglutamate desuccinylase, respectively, and the aruF and aruG genes encode the subunits (AruAI and AruAII) of arginine and ornithine N2-succinyltransferases . Furthermore, in vivo analysis of transcriptional aru fusions and of polar insertion mutations located at different sites in the aru cluster indicated the presence of three transcriptional units which are controlled by ArgR . The aruCFGDB genes appear to form an operon transcribed from a promoter upstream of aruC, whereas aruE has its own promoter . The argR gene, which is located upstream of the aruCFGDB operon, is a member of another (aot) operon coding for arginine transport genes . The deduced amino acid sequences of the AST enzymes were compared to those of homologous proteins of Escherichia coli specified by the ast genes lying in the chromosome region from 39.2 to 39.5 min (Kohara clone 327; GenBank/EMBL/DDJB accession no . D90818) . The overall organization of the aru and ast genes in both organisms is similar, with the exception that E . coli appears to have a single AST gene. APMIS, 1997 Nov, 105(11), 838 - 42 Chronic Pseudomonas aeruginosa lung infection is more severe in Th2 responding BALB/c mice compared to Th1 responding C3H/HeN mice; Moser C et al.; The chronic Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) is characterized by a pronounced antibody response and microcolonies surrounded by numerous polymorphonuclear neutrophils (PMN) . Poor prognosis is correlated with a high antibody response to P . aeruginosa antigens . An animal model of this infection was established in two strains of mice: C3H/HeN and BALB/c, generally known as Th1 and Th2 responders, respectively, which were challenged with alginate-embedded P . aeruginosa . Mortality was significantly lower in C3H/HeN compared to BALB/c mice (p < 0.025) . P . aeruginosa was cleared more efficiently in C3H/HeN mice and significantly more C3H/HeN mice showed normal lung histopathology (p < 0.02), and we found significantly fewer microabscesses in C3H/HeN mice than in BALB/c mice (p < 0.005) . In supernatants from P . aeruginosa antigen and concanavalin A-stimulated spleen cells from the two strains of mice, the interferon-(IFN-) gamma levels were higher, whereas IL-4 levels were lower in C3H/HeN mice than in BALB/c mice . The implications of these findings for CF patients with chronic P . aeruginosa lung infection are discussed. Mol Plant Microbe Interact, 1997 Dec, 10(9), 1054 - 64 A regulatory locus, pehSR, controls polygalacturonase production and other virulence functions in Ralstonia solanacearum; Allen C et al.; We previously identified a locus that regulates production of polygalacturonase (PG), an extracellular plant cell wall-degrading enzyme important in bacterial wilt of plants caused by Ralstonia (Pseudomonas) solanacearum . The DNA sequence of this locus, called pehSR, was determined and two consecutive open reading frames (ORFs) of 1,905 and 1,680 bp were identified . The amino acid sequences predicted to be encoded by these ORFs are similar to those of regulators of pilin synthesis in Pseudomonas aeruginosa and Myxococcus xanthus and to a regulator of flagellin synthesis and adhesion in P . aeruginosa, as well as to other two-component regulators of the NtrB/C subfamily . pehSR mutants produced negligible levels of endo-PG activity, while exo-PG activity was reduced by 50% . Northern (RNA) blot analysis showed that PehSR regulates endo-PG expression at the transcriptional level . pehSR mutants grew normally in culture and in planta but were dramatically reduced in virulence; this loss of virulence was substantially greater than that observed for endo-PG structural gene mutants, suggesting that pehSR regulates additional factors important in virulence . Although pehSR mutants were essentially nonmotile, like the wild-type strain, multiple copies of pehSR conferred motility on the bacterium . Reporter gene studies indicated that pehSR expression increased when bacteria grew in plant tissue, and that the pehSR locus was itself negatively regulated by the global virulence gene regulator PhcA. Hybridoma, 1997 Oct, 16(5), 413 - 20 Pharmacokinetics, tolerability, and preliminary efficacy of human anti-Pseudomonas aeruginosa monoclonal antibodies in pneumonia and burn infection patients; Harrison FJ et al.; Human monoclonal antibody (hMAb) cocktail SM-17220 (also known as BT-570), a heterofunctional antibody mixture of 3 human IgM MAbs (HI-223, MH-4H7, and IN-2A8; ratio of 1:10:10) directed against Pseudomonas aeruginosa, were administered to patients with pneumonia or burn wounds (or both) to assess the pharmacokinetics, safety, antigenicity, and preliminary efficacy . Twenty mg of SM-17220 was IV infused over 60 min once daily on 3 consecutive days . Twenty patients (8 pneumonia, 4 burns, and 8 both) completed the study . SM-17220 was safe and well tolerated, and no subjects developed antibodies to SM-17220 and mouse J-chain during the follow-up of 8 weeks . Each MAb of SM-17220 had a half-life ranging from 49 to 91 h, similar to native human IgM . Both MH-4H7 and IN-2A8 administration resulted in a high serum level for about 4 days over an effective concentration, whereas HI-223 showed a lower serum level than expected . Some indications of a potential efficacy were observed and are discussed here. Eur Respir J, 1997 Oct, 10(10), 2312 - 8 Mucociliary clearance in cystic fibrosis knockout mice infected with Pseudomonas aeruginosa; Cowley EA et al.; In this study, we examined whether mucociliary clearance differed between cystic fibrosis (CF) knockout mice and wildtype controls . Additionally, we investigated whether infection with Pseudomonas aeruginosa, a common pathogen in the CF lung, affected this important host defence mechanism . Ciliary beat frequency (fcb) and particle transport (PT) were recorded using an in vitro lung explant preparation . Measurements were made from uninfected cystic fibrosis transmembrane conductance regulator (CFTR) knockout (-/-) mice and littermate controls (+/+) and compared to measurements from infected animals . While there were no differences detectable in fcb between CFTR -/- mice and their +/+ controls either in the presence or absence of P . aeruginosa, PT rates were different between these groups; interestingly, PT rates appeared dependent on both CFTR and infection status, with uninfected CFTR +/+ animals demonstrating higher rates of PT than their -/- littermates, while CFTR +/+ P . aeruginosa-infected mice demonstrated lower PT than knockout mice . These data demonstrate differences in mucociliary clearance between cystic fibrosis transmembrane conductance regulator knockout mice and controls, and further that Pseudomonas aeruginosa infection affects mucociliary clearance in the peripheral airways of mice . Additionally, the observed differences in particle transport suggest that cystic fibrosis transmembrane conductance regulator knockout mice demonstrate different mucociliary responses to infection. Microbiology, 1997 Nov, 143 ( Pt 11), 3473 - 80 Pseudomonas aeruginosa in cystic fibrosis: role of mucC in the regulation of alginate production and stress sensitivity; Boucher JC et al.; Alginate production in Pseudomonas aeruginosa and the associated mucoid phenotype of isolates from cystic fibrosis patients are under the control of the algU mucABCD cluster . This group of genes encodes AlgU, the P . aeruginosa equivalent of the extreme heat shock sigma factor sigma E in Gram-negative bacteria, the AlgU-cognate anti-sigma factor MucA, the periplasmic protein MucB and a serine protease homologue, MucD . While mucA, mucB or mucD act as negative regulators of AlgU, the function of mucC is not known . In this study the role of mucC in P . aeruginosa physiology and alginate production has been addressed . Insertional inactivation of mucC in the wild-type P . aeruginosa strain PAO1 did not cause any overt effects on alginate synthesis . However, it affected growth of P . aeruginosa under conditions of combined elevated temperature and increased ionic strength or osmolarity . Inactivation of mucC in mucA or mucB mutant backgrounds resulted in a mucoid phenotype when the cells were grown under combined stress conditions of elevated temperature and osmolarity . Each of the stress factors tested separately did not cause comparable effects . The combined stress factors were not sufficient to cause phenotypically appreciable enhancement of alginate production in mucA or mucB mutants unless mucC was also inactivated . These findings support a negative regulatory role of mucC in alginate production by P . aeruginosa, indicate additive effects of muc genes in the regulation of mucoidy in this organism and suggest that multiple stress signals and recognition systems participate in the regulation of algU-dependent functions. J Bacteriol, 1997 Nov, 179(22), 7004 - 10 Use of steroids to monitor alterations in the outer membrane of Pseudomonas aeruginosa; Plesiat P et al.; Testosterone (a strongly hydrophobic steroid) and testosterone hemisuccinate (a negatively charged derivative) were used as probes to investigate alterations in the outer membrane of Pseudomonas aeruginosa . Diffusion rates of the steroids across the lipid bilayer were measured by coupling the influx of these compounds to their subsequent oxidation by an intracellular delta1-dehydrogenase enzyme . Wild-type cells of P . aeruginosa (strain PAO1) were found to be 25 times more permeable to testosterone than to testosterone hemisuccinate . The uptake of the latter compound appeared to be partially dependent on the external pH, thus suggesting a preferential diffusion of the uncharged protonated form across the cell envelope . Using various PAO mutants, we showed that the permeation of steroids was not affected by overexpression of active efflux systems but was increased up to 5.5-fold when the outer membrane contained defective lipopolysaccharides or lacked the major porin OprF . Such alterations in the hydrophobic uptake pathway were not, however, associated with an enhanced permeability of the mutants to the small hydrophilic molecule N,N,N',N'-tetramethyl-p-phenylene diamine . Thirty-six agents were also assayed for their ability to damage the cell surface of strain PAO1, using testosterone as a probe . Polymyxins, rBPI23, chlorhexidine, and dibromopropamidine demonstrated the strongest permeabilizing activities on a molar basis in the presence of 1 mM MgCl2 . These amphiphilic polycations increased the transmembrane diffusion of testosterone up to 50-fold and sensitized the PAO1 cells to hydrophobic antibiotics . All together, these data indicated that the steroid uptake assay provides a direct and accurate measurement of the hydrophobic uptake pathway in P . aeruginosa. Antimicrob Agents Chemother, 1997 Nov, 41(11), 2540 - 3 Differential selection of multidrug efflux systems by quinolones in Pseudomonas aeruginosa; Kohler T et al.; Resistance mechanisms selected after in vitro exposure to 12 quinolones were analyzed for Pseudomonas aeruginosa . Efflux-type mutants were predominant . Quinolones differed in their ability to select a particular efflux system . While the newer fluoroquinolones favored the MexCD-OprJ system, the older quinolones selected exclusively the MexEF-OprN or MexAB-OprM systems . A protonable C-7 substituent in combination with a C-6 fluorine atom is a structural determinant of quinolones involved in efflux pump substrate specificity. Antimicrob Agents Chemother, 1997 Nov, 41(11), 2527 - 32 Comparative bactericidal activity of ceftazidime against isolates of Pseudomonas aeruginosa as assessed in an in vitro pharmacodynamic model versus the traditional time-kill method; Manduru M et al.; Bactericidal activity, historically assessed by in vitro tests which employ fixed drug concentrations, may also be evaluated in in vitro pharmacodynamic models in which in vivo pharmacokinetics and bacterial growth conditions can be simulated . However, systematic comparisons between the two methods are lacking . We evaluated the bactericidal activities of ceftazidime, at two different concentration/MIC ratios (C/MICs), against 10 clinical isolates of Pseudomonas aeruginosa in a two-compartment model with continuous-infusion conditions and a 2-h half-life . These values were compared to those determined by traditional 24-h time-kill (TTK) methods at the same C/MICs . Bactericidal activities were compared by using area under the colony count-time curves . Antibiotic exposure (area under the drug concentration-time curve) was also evaluated . Although bactericidal activity appeared greater by the TTK method (P = 0.05), when it was normalized for drug exposure, these differences disappeared (P = 0.2) . This disparity was likely due to differences in drug exposure in the TTK method and in the peripheral compartment of the model (site of bacteria) over the first 8 h of the experiment, during which the antibiotic accumulated to target concentrations . This suggests that the bactericidal effects with constant antibiotic concentrations are similar in the two methods; however, this may not hold true with fluctuating drug concentrations . Further, results from the pharmacodynamic model may theoretically be more relevant, as in vivo pharmacokinetics and bacterial growth conditions call be more faithfully simulated. Antimicrob Agents Chemother, 1997 Nov, 41(11), 2511 - 7 Pharmacokinetics and pharmacodynamics of two multiple-dose piperacillin-tazobactam regimens; Occhipinti DJ et al.; The pharmacokinetics and pharmacodynamics of two multiple-dose regimens of piperacillin-tazobactam (3.375 g every 6 h and 4.5 g every 8 h) were evaluated at steady state for 12 healthy adult volunteers . Inhibitory and bactericidal activities for the two regimens were determined with five American Type Culture Collection (ATCC) organisms (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Bacteroides fragilis) . The percentage of time that plasma concentrations remained above the MIC (T > MIC) for each organism and dosage regimen was calculated . Areas under the inhibitory (AUIC0-24) and bactericidal activity (AUBC0-24) curves were calculated with the trapezoidal rule by using the reciprocal of the inhibitory and bactericidal titers determined for each dosage regimen . In order to assess the validity of predicted measures of bactericidal (AUC0-24/MBC) and inhibitory (AUC0-24/MIC) activity to determine bacteriological response to beta-lactam antimicrobial agents, AUC0-24/MBC and AUC0-24/MIC values were compared with measured AUBC0-24 and AUIC0-24 values . Total body clearance values were equivalent for piperacillin (183.96 +/- 22.66 versus 181.72 +/- 19.54 ml/min/1.73 m2, P > 0.05) and tazobactam (184.71 +/- 19.89 versus 184.87 +/- 18.35 ml/min/1.73 m2, P > 0.05) following the administration of the 3.375-g-every-6-h and 4.5-g-every-8-h dosages, respectively . Comparison of area under the plasma concentration-time curve (AUC0-24) for piperacillin (967.74 +/- 135.56 microg x h/ml versus 978.88 +/- 140.96 microg x h/ml) and tazobactam (120.14 +/- 15.78 microg x h/ml versus 120.01 +/- 16.22 microg x h/ml) revealed no significant differences (P > 0.05) between the 3.375-g-every-6-h and 4.5-g-every-8-h regimens, respectively . Both regimens provided T > MIC values of > 60% for all organisms tested . Measured values of bactericidal (AUBC) and inhibitory (AUIC) activity were significantly different (P < 0.05) from predicted values (AUC0-24/MBC and AUC0-24/MIC) for all organisms studied with the exception of the bactericidal activity for P . aeruginosa and S . aureus . Additionally, ATCC organisms possessing the same MICs and MBCs exhibited great differences in measured AUBC0-24 and AUIC0-24 values . Reasons for this difference may be inherent differences in organism specific susceptibility. Arzneimittelforschung, 1997 Oct, 47(10), 1134 - 8 Synthesis and antibacterial activity of 5-aryl-2-{(alpha-chloro-alpha-phenylacetyl/alpha-bromopropionyl)amino}- 1,3,4-oxadiazoles and 2-{(5-aryl-1,3,4-oxadiazol-2-yl)imino}-5-phenyl/methyl-4-thiazolidinone s; Ates O et al.; Reaction of 5-aryl-2-amino-1,3,4-oxadiazoles (BI-VI), obtained by the oxydative cyclization of aromatic aldehyde semicarbazones (AI-VI), with alpha-chloro-alpha-phenylacetyl chloride and alpha-bromopropionyl bromide yielded 5-aryl-2-{(alpha-chloro-alpha-phenylacetyl)amino}-1,3,4-oxadiazoles (Ia-VIa) and 5-aryl-2-{(alpha-bromopropionyl)amino}-1,3,4-oxadiazoles (VIIa-XIIa), respectively . Furthermore, Ia-XIIa were refluxed with ammonium thiocyanate to give 5-phenyl/methyl-2-{(5-aryl-1,3,4-oxadiazol-2-yl)imino}-4-thiazo lidinones (It-XIIt) . All compounds were tested for antibacterial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa . They were all found to possess significant activity against S . aureus with MIC values ranging from 0.24 to 125 micrograms/ml . LD50 of compounds chosen as prototypes are estimated. Ann Hematol, 1997 Sep, 75(3), 121 - 3 Pseudomonas aeruginosa blepharoconjunctivitis during cytoreductive chemotherapy in a woman with acute lymphocytic leukemia; Giagounidis AA et al.; Patients undergoing chemotherapy regimens for hematologic malignancies are prone to develop unusual and potentially life-threatening infections during periods of leukopenia- induced immunosuppression . We report the case of a woman who received consolidation chemotherapy for acute lymphocytic leukemia and acquired necrotizing Pseudomonas aeruginosa blepharoconjunctivitis of the right eye during a period of mild leukopenia . The infection led to severe orbital and periorbital inflammation, spreading down to the neck . High-dose antibiotic treatment with ceftazidime and tobramycin combined with granulocyte cell-stimulating factor cleared the infection after several days, but plastic surgery was needed to restore normal eye closure. FEMS Microbiol Lett, 1997 Nov 1, 156(1), 101 - 6 Isolation and characterization of an Azotobacter vinelandii algK mutant; Mejia-Ruiz H et al.; Random Tn5 mutagenesis over Azotobacter vinelandii mucoid strain ATCC 9046 produced strain LA21, a non-mucoid, non-encysting mutant, carrying the Tn5 insertion within a gene homologous to algK from Pseudomonas aeruginosa encoding a periplasmic protein . algK, algJ and algG were shown to be transcribed as part of the palg8-alg44-algK-algJ-algG operon . A non-polar algK mutant was constructed and showed a non-mucoid phenotype, indicating that algK is essential for alginate production. Diagn Microbiol Infect Dis, 1997 Oct, 29(2), 81 - 6 Comparative in vitro interactions of ceftazidime, meropenem, and imipenem with amikacin on multiresistant Pseudomonas aeruginosa; Giamarellos-Bourboulis EJ et al.; To evaluate the possibility of an enhanced killing effect by ceftazidime, meropenem, or imipenem with amikacin 26 multiresistant Pseudomonas aeruginosa isolates, to nine anti-pseudomonal antimicrobials of diverse chemical classes were studied . A modified time-kill curve procedure was used with a 16 micrograms/ml concentration of each antimicrobial, i.e . within the range of their serum level; a total of 248 killing-curves were performed . Any > or = 2 log10 decrease of viable cell counts by a combination compared to the most active single agent was considered an adequate enhanced killing effect . The latter was found to be mainly expressed at 24 h of growth and involved 30-50% of the tested isolates . The above findings were independent of the MIC level to any individual beta-lactam or to amikacin . It is concluded that there is no difference between the activity of the ceftazidime and amikacin combination and those of meropenem or imipenem with amikacin on multiresistant P . aeruginosa. Crit Care Med, 1997 Nov, 25(11), 1862 - 7 Survival in patients with nosocomial pneumonia: impact of the severity of illness and the etiologic agent; Rello J et al.; OBJECTIVE: To assess the impact of severity of illness at different times, using the Mortality Probability Models (MPM II), and the impact of etiologic agent on survival in patients with nosocomial pneumonia . DESIGN: Retrospective, observational study . SETTING: Fourteen-bed medical-surgical intensive care unit (ICU) in a teaching hospital . PATIENTS: Sixty-two patients with nosocomial pneumonia who were receiving early appropriate antibiotic treatment . INTERVENTIONS: None . MEASUREMENTS AND MAIN RESULTS: Severity of illness at the time of admission to the ICU (M0), 24 hrs after admission (M24), and at the time of pneumonia diagnosis (M1) was determined using MPM II . Bacteriology was established by quantitative cultures from bronchoscopic samples . The outcome measure was the crude mortality rate . The crude mortality rate in the ICU was 59.7%, compared with average predicted mortality rates of 43.5% (M0), 36.4% (M24), and 52.2% (M1) . We observed significant differences in mean MPM II determinations between survivors and nonsurvivors at M1 (39.3% vs . 60.9%, p = .001) but not at M0 and M24 . In the univariate analysis, the variables most predictive of mortality were the presence of coma (p = .02), inotropic medication use (p = .001), and an MPM II determination of > 50% (p = .001) when pneumonia was diagnosed (M1) . Multivariate analysis showed that, in the absence of Pseudomonas aeruginosa, an MPM II determination of > 50% at M1 was associated with a relative risk of death of 4.8 . The presence of P . aeruginosa was associated with an increase in the risk of death of 2.6 and 6.36 in both populations with MPM II determinations at M1 of < or = 50% and > 50%, respectively . CONCLUSIONS: Severity of illness when pneumonia is diagnosed is the most important predictor of survival, and this determination should be used for therapeutic and prognostic stratification . In addition, the presence of P . aeruginosa contributed to an excess of mortality that could not be measured by MPM II alone, suggesting the importance of the pathogen in prognosis. Arch Otolaryngol Head Neck Surg, 1997 Nov, 123(11), 1193 - 200 Ofloxacin otic solution for treatment of otitis externa in children and adults; Jones RN et al.; OBJECTIVE: To compare the safety and efficacy of ofloxacin otic solution with those of Cortisporin otic solutions (neomycin sulfate, polymyxin B sulfate, and hydrocortisone) in otitis externa in adults and children . DESIGN: Two randomized, evaluator-blind, multicenter trials, 1 each in children and adults . SETTING: Twenty-three primary care and referral ambulatory care sites per trial . PATIENTS: A total of 314 adults (12 years and older) and 287 children (younger than 12 years) . Of the total, data for 247 adults and 227 children were considered clinically evaluable (CE), and those for 98 children and 98 adults were microbiologically evaluable (ME) . INTERVENTIONS: Ofloxacin (adults, 0.5 mL; children, 0.25 mL) twice daily or Cortisporin (adults, 0.2 mL; children, 0.15 mL) 4 times daily for 10 days . MAIN OUTCOME MEASURES: The CE subjects were cured if all signs and symptoms resolved at posttherapy (days 11-13) and test-of-cure (days 17-20) visits . The ME subjects had microbiological and clinical successes if they were cured and had microbiological eradication or presumed eradication . RESULTS: Cure was observed in 82% and 97% of CE adults and children treated with ofloxacin and 84% and 95% of CE adults and children treated with Cortisporin, respectively . The most common pathogens at the pretherapy visit were Pseudomonas aeruginosa, Staphylococcus aureus, and enteric bacilli . There were no statistically significant differences in clinical or microbiological and clinical cure or in the rates of adverse events between treatment groups . CONCLUSIONS: Ofloxacin given twice daily is as safe and effective as Cortisporin given 4 times daily for otitis externa . The bacteriological findings and treatment responses do not differ between adults and children. Cytobios, 1997, 89(357), 73 - 80 Identification of immune inhibitor from Pseudomonas aeruginosa of inducible cell-free antibacterial activity in insects; Jarosz J; Insect-pathogenic strains of Pseudomonas aeruginosa produce specific proteinase which selectively degrades the cecropin-based defence system of insects . This was demonstrated by the disappearance of the Galleria cecropin and purified Hyalophora cecropin B peptide PAGE bands, but not the lysozyme band, upon exposure to infected extracts and a similar abrogation of antibacterial activity using an agar diffusion assay . In addition, the proteolytic activity of infected extracts produced by high and low virulence Pseudomonas strains was shown to be correlated with cecropin-inhibitory activity . This indicated that the bacterial proteinase was responsible for the ability of bacteria to establish infections and strain virulence. Curr Opin Pulm Med, 1996 Nov, 2(6), 439 - 46 Antibiotic use in cystic fibrosis; Eisenberg JD; Antibiotic administration is the mainstay of therapy for pulmonary disease in patients with cystic fibrosis (CF) . The progressive nature of the pulmonary disease in CF shortens survival . New and potent antibiotics, more aggressive antibiotic therapy, and multiple routes of administration have contributed to improved survival among CF patients . Pseudomonas aeruginosa is the predominant bacterial pathogen in the lower airways of CF patients . Most of the efforts in treating the chronic pulmonary infection are directed toward this organism . Aerosol aminoglycoside delivery provides a safe and effective alternative method to parenteral administration for treating patients who require chronic antibiotic therapy . This article reviews strategies for choosing antibiotics and current opinions regarding antibiotic therapy for patients with CF. Curr Opin Pulm Med, 1995 Nov, 1(6), 444 - 9 Prognosis in cystic fibrosis; Rosenstein BJ et al.; Prognosis for patients with cystic fibrosis has improved dramatically over the past three decades . In the United States, median survival age is now 28.9 years . Although genotype predicts exocrine pancreatic function, it does not correlate with pulmonary status or overall clinical outcome . However, there are a number of parameters, such as exocrine pancreatic sufficiency, male gender, absence of colonization with mucoid Pseudomonas aeruginosa, presentation with predominantly gastrointestinal symptoms, balanced family functioning and coping, and compliance with treatment regimens, that predict a more favorable outcome . The impact of early diagnosis and treatment is still controversial . Although nonblinded studies indicate decreased morbidity in the first 2 to 4 years of life among patients diagnosed by newborn screening, no data support long-term benefit in terms of pulmonary function or survival . With increased longevity, there is now evidence of a small but significantly increased risk of gastrointestinal tract cancer among patients with cystic fibrosis. ASAIO J, 1997 Sep-Oct, 43(5), M854 - 7 A novel wound dressing with an antibiotic delivery system stimulated by microbial infection; Suzuki Y et al.; The aim of this study was to develop a new wound dressing with controlled release of antibiotics only in the presence of infection . In the first experiment using an infected dorsal pouch of rats, exudate containing proteinases from pouches contaminated with Staphylococcus aureus or Pseudomonas aeruginosa showed significantly higher hydrolytic activity toward Boc-Val-Pro-Arg-MCA than that from noninfected wounds . The authors then developed a new type of wound dressing (AGX), a drug delivery system in which gentamicin is bound to polyvinylalcohol hydrogel through an enzymatically degradable peptide linker containing a -(D)-Phe-Pro-Arg-sequence . To investigate in vitro effectiveness, AGX was incubated with exudate from S . aureus infected or P . aeruginosa infected wounds . Gentamicin was selectively released from AGX in the presence of the exudate from S . aureus infected or P . aeruginosa infected wounds, but was not released in the presence of exudate from noninfected wounds . Next, AGX or the polyvinylalcohol hydrogel that served as control was incubated with S . aureus in the presence of human plasma . After 24 hours, S . aureus concentration was markedly lower in the case with AGX than in that with polyvinylalcohol hydrogel . These results indicate that proteinases from wounds infected with S . aureus or P . aeruginosa cleaved the linker and gentamicin was released. J Infect Dis, 1997 Nov, 176(5), 1293 - 302 Intraportal lipopolysaccharide suppresses pulmonary antibacterial defense mechanisms; Mason CM et al.; Translocation of enteric bacteria or their components (or both) has been postulated to play a role in precipitating sepsis or the systemic inflammatory response syndrome . To simulate the effects of translocation on pulmonary host defenses, lipopolysaccharide was injected into the portal vein of normal rats that were subsequently challenged by aerosol inoculation with Pseudomonas aeruginosa . Injection of LPS into the portal vein resulted in increased serum tumor necrosis factor (TNF)-alpha levels and reduction in lung clearance of P . aeruginosa after aerosol challenge . There were corresponding reductions in alveolar neutrophil recruitment, diminished alveolar macrophage phagocytosis and superoxide anion (O2-) production, and diminished lung TNF recovered by bronchoalveolar lavage . Furthermore, prior intravenous injection of recombinant TNF-alpha reproduced the defective bacterial clearance, the altered recruitment of airspace neutrophils, and the defective alveolar macrophage phagocytosis . Thus, systemic TNF-alpha is important in altering pulmonary defenses, and this work supports the concept that bacterial translocation may adversely affect host defenses in distant organs. Gene, 1997 Oct 15, 199(1-2), 271 - 7 The Azotobacter vinelandii alg8 and alg44 genes are essential for alginate synthesis and can be transcribed from an algD-independent promoter; Mejia-Ruiz H et al.; A 2.8-kb DNA region, located immediately downstream of algD, contains the A . vinelandii alg8 and alg44 genes, whose sequences are highly homologous to those of the corresponding Pseudomonas aeruginosa genes . These genes occur on a transcript that does not include algD, and are transcribed from a promoter different from that transcribing algD; this is the fourth promoter described within the alginate biosynthetic gene cluster . alg8 and alg44 mutants were constructed and shown to be completely impaired in alginate production . Alg8 shares 28.20% identity and 38.09% similarity to Azorhizobium caulinodans NodC, a glycosyl transferase catalyzing the formation of beta-1,4 linkages . A topological model is predicted, which supports the idea of Alg8 being the polymerase responsible for alginate synthesis. Microbiology, 1997 Oct, 143 ( Pt 10), 3223 - 9 Genetic identification of chemotactic transducers for amino acids in Pseudomonas aeruginosa; Taguchi K et al.; Two chemotactic transducer genes (termed pctB and pctC) and an open reading frame (orf1) were found in the pctA-flanking region which was previously identified as a chemotactic transducer gene in Pseudomonas aeruginosa . The pctB and pctC genes encode predicted polypeptides of 629 and 632 amino acids, respectively . Overall, PctB and PctC had 81 and 75% amino acid identities with PctA, respectively . A null mutant strain PCT2, which contained a deletion in the entire pctC, orf1, pctA and pctB genes, did not show chemotaxis towards all 20 commonly occurring L-amino acids . This mutant strain also failed to respond to amino acid catabolites (cadaverine, 4-aminobutyrate and putrescine) that are strong attractants for the wild-type strain PAO1 . To study the role of each gene product in L-amino acid taxis, plasmids harbouring the pctC, orf1, pctA, or pctB genes were constructed and introduced into strain PCT2 by transformation . The orf1 gene did not complement the defect in chemotaxis of strain PCT2 . The pctA gene restored the ability of strain PCT2 to respond to 18 L-amino acids, suggesting that PctA plays a major role in detecting L-amino acids in P . aeruginosa . The pctB and pctC genes complemented the defect in chemotaxis to only seven (Ala, Arg, Glu, Lys, Met, Tyr, Gln) and two (His, Pro) L-amino acids, respectively. Microbiology, 1997 Oct, 143 ( Pt 10), 3111 - 22 Disruption of the Pseudomonas aeruginosa dipZ gene, encoding a putative protein-disulfide reductase, leads to partial pleiotropic deficiency in c-type cytochrome biogenesis; Page MD et al.; The Pseudomonas aeruginosa dipZ gene has been cloned and sequenced . Whereas disruption of Escherichia coli dipZ (dsbD), the hydrophilic C-terminal domain of which has been deduced to be periplasmic and to function as a protein-disulfide reductase, leads to the absence of c-type cytochromes, disruption of P . aeruginosa dipZ attenuated, but did not abolish, holo-c-type cytochrome biosynthesis . Comparison of the P . aeruginosa DipZ sequence with three other DipZ sequences indicated that there are not only two conserved cysteine residues in the C-terminal hydrophilic domain, but also two more in the central highly hydrophobic domain . The latter would be located toward the centre of two of the eight membrane-spanning alpha-helices predicted to compose the hydrophobic central domain of DipZ . Both these cysteine residues, plus other transmembrane helix residues, notably prolines and glycines, are also conserved in a group of membrane proteins, related to Bacillus subtilis CcdA, which lack the N- and C-terminal hydrophilic domains of the DipZ proteins . It is proposed that DipZ of P . aeruginosa and other organisms transfers reducing power from the cytoplasm to the periplasm through reduction and reoxidation of an intramembrane disulfide bond, or other mechanism involving these cysteine residues, and that this function can also be performed by B . subtilis CcdA and other CcdA-like proteins . The failure of dipZ disruption to abolish c-type cytochrome synthesis in P . aeruginosa suggests that, in contrast to the situation in E . coli, the absence of DipZ can be compensated for by one or more other proteins, for example a CcdA-like protein acting in tandem with one or more thioredoxin-like proteins. Microbiologia, 1997 Sep, 13(3), 285 - 300 Antibacterial efflux systems; Marshall NJ et al.; Drug efflux, unidirectional pumping of cytotoxic drugs, is a major mechanism of antimicrobial multiresistance in bacteria . Although these efflux systems are usually chromosomally encoded, some are present on plasmids . Some of the efflux pumps are relatively well known: Emr and Acr system in Escherichia coli, whose outer membrane protein seems to be the multifunctional To1C; the mex efflux system described in Pseudomonas aeruginosa and ABC-type in Gram-negative bacteria . Also the role of efflux in Gram-positive bacteria are reviewed including Bacillus, Staphylococcus and Streptomyces. Microbiologia, 1997 Sep, 13(3), 273 - 84 Multiantibiotic resistance caused by active drug extrusion in Pseudomonas aeruginosa and other gram-negative bacteria; Nakae T; All living organisms have been exposed to noxious compounds throughout their long evolutionary history and those surviving have evolved to fabricate devices that detoxicate and extrude these life threatening substances . It is likely, therefore, that all viable organisms, from bacteria to mammals, are equipped with active extrusion machinery . When bacteria are attacked by antibiotics, they use these tactics to combat the drugs and to develop resistance . Drugs extrusion machinery in Gram-negative bacteria is complex, consisting of the inner membrane transporter which acts as an energy-dependent extrusion pump; a binding protein which presumably connect both membranes; and the outer membrane exit channel . The extrusion pump assemblies are often encoded by chromosomal genes and might be expressed by mutation(s) or induced in the presence of drug(s). Zentralbl Hyg Umweltmed, 1996 Jul, 198(6), 522 - 30 Effect of water softening and heating on microbial contamination of dental unit systems; Stampi S et al.; This study regards the quality of the water used in 4 types of dental units making use of softened and heated water, softened but non-heated water, non-softened but heated water and non-softened and non-heated water . The samples were taken from the incoming tap water, from oral rinsing cup, the air-water syringe and the ultrasound descaling hand-piece . The results showed how the water underwent a notable growth in bacteria during its passage within the circuits of the units, reaching heterotrophic total counts greatly exceeding the guidelines set down by Italian laws regarding drinking water . While the influence of softening was evident, the bacteria in the samples taken from descaling handpiece, where there is more stagnation, found excellent growing conditions also at high temperatures . In the softened and heated waters a notable growth of Pseudomonas aeruginosa was found and it is likely that this was encouraged by the combined effect of the softening and heating . As far as the origin of the contamination is concerned, the bacteria present in the water systems seem to have come from the incoming water. Appl Microbiol Biotechnol, 1997 Sep, 48(3), 281 - 8 Bacterial alginates: biosynthesis and applications; Rehm BH et al.; Alginate is a copolymer of beta-D-mannuronic acid and alpha-L-guluronic acid (GulA), linked together by 1-4 linkages . The polymer is a well-established industrial product obtained commercially by harvesting brown seaweeds . Some bacteria, mostly derived from the genus Pseudomonas and belonging to the RNA superfamily I, are also capable of producing copious amounts of this polymer as an exopolysaccharide . The molecular genetics, regulation and biochemistry of alginate biosynthesis have been particularly well characterized in the opportunistic human pathogen Pseudomonas aeruginosa, although the biochemistry of the polymerization process is still poorly understood . In the last 3 years major aspects of the molecular genetics of alginate biosynthesis in Azotobacter vinelandii have also been reported . In both organisms the immediate precursor of polymerization is GDP-mannuronic acid, and the sugar residues in this compound are polymerized into mannuronan . This uniform polymer is then further modified by acetylation at positions O-2 and/or O-3 and by epimerization of some of the residues, leading to a variable content of acetyl groups and GulA residues . In contrast, seaweed alginates are not acetylated . The nature of the epimerization steps are more complex in A . vinelandii than in P . aeruginosa, while other aspects of the biochemistry and genetics of alginate biosynthesis appear to be similar . The GulA residue content and distribution strongly affect the physicochemical properties of alginates, and the epimerization process is therefore of great interest from an applied point of view . This article presents a survey of our current knowledge of the molecular genetics and biochemistry of bacterial alginate biosynthesis, as well as of the biotechnological potential of such polymers. Am J Respir Crit Care Med, 1997 Oct, 156(4 Pt 1), 1190 - 6 Controlled trial of inhaled budesonide in patients with cystic fibrosis and chronic bronchopulmonary Psuedomonas aeruginosa infection; Bisgaard H et al.; The efficacy and safety of anti-inflammatory treatment with inhaled glucocorticosteroids in patients with cystic fibrosis (CF) and complicating chronic Pseudomonas aeruginosa (P.a.) lung infection was studied in a placebo-controlled, parallel, double-blind single center trial . Active treatment consisted of budesonide dry powder, 800 microg twice daily, delivered from a Turbuhaler . The study period covered two successive 3-mo intervals between elective courses of intravenous anti-Pseudomonas antibiotics . Fifty-five patients entered the study, with a mean age of 20 yr and a mean FEV1 of 63% of predicted . Analysis of all patients entered, irrespective of trial adherence ("intention to treat"), showed a decrease in FEV1 in the first period of -0.032 L in patients on budesonide versus -0.187 L in patients on placebo (p = 0.08) . The corresponding figures for the patients adhering to the protocol during the first period were -0.017 L versus -0.198 L (p < 0.05, confidence interval of the difference: -0.035 to +0.327 L) . For all patients entered, as well as for patients adhering to the trial, there was always a trend in favor of budesonide, as judged by changes in FEV1 and FVC in both 3-mo periods . None of the patients had asthma, but the patients on budesonide had a mean improvement in histamine reactivity of +1.15 dose steps over the entire 6-mo period, as opposed to +0.017 dose steps in patients on placebo (p < 0.05) . There was also a significant (p = 0.01) correlation between pre-trial histamine reactivity and the change in FEV1 in the first period in patients on budesonide . We conclude that inhaled glucocorticosteroids can be of short-term benefit in patients with CF and chronic P.a . infection and that those patients most likely to benefit from this treatment are patients with hyperreactive airways . Prolonged studies in larger number of patients are necessary to determine the long-term efficacy of this treatment. Lett Appl Microbiol, 1997 Oct, 25(4), 279 - 83 Interaction of silver nitrate with readily identifiable groups: relationship to the antibacterial action of silver ions; Liau SY et al.; Microbiologically it was demonstrated that amino acids, e.g . cysteine (CySH), and other compounds, e.g . sodium thioglycollate, containing thiol groups neutralized the activity of silver nitrate against Pseudomonas aeruginosa PAO1 . Amino acids with disulphide bonds were inactive, with the exception of L-cystine dimethyl ester, as were all amino acids with no sulphur groups . Iodoacetamide reacted with CySH to produce a CyS-acetamide complex that was unable to quench the activity of Ag+ . Chemical analyses using cyclic voltammetry demonstrated that high coordination numbers (3.1) were obtained with thiol-containing amino acids and low numbers (0.28-0.4) with other amino acids . Both microbiologically and chemically, the results imply that interaction of Ag+ with thiol groups plays an essential role in bacterial inactivation. FEMS Microbiol Lett, 1997 Oct 15, 155(2), 217 - 22 Sequence analysis of a 1296-nucleotide plasmid from Xylella fastidiosa; Pooler MR et al.; A cryptic plasmid from Xylella fastidiosa strain ATCC 35868 was cloned, sequenced, and the sequence entered into GenBank (U71220) . The plasmid is 1296 nucleotides in length with 55% GC content and three open reading frames . A plasmid with sequence homology was found in only one other strain of X . fastidiosa, ATCC 35878 . Searches of the GenBank reveal nucleotide sequence homology with plasmid pNKH43 from Stenotrophomonas maltophilia, and amino acid sequence homology with phage Pf3 from Pseudomonas aeruginosa, plasmid pAP12875 from Acetobacter pasteurianus, and plasmid pVT736-1 from Actinobacillus actinomycetemcomitans. Scand J Immunol, 1997 Oct, 46(4), 358 - 65 Mannuronan enhances survival of lethally irradiated mice and stimulates murine haematopoiesis in vitro; Halaas O et al.; Mannuronan (poly-beta-(1-->4)-D-mannuronate or poly-M), produced by Pseudomonas aeruginosa as a mucoid exopolysaccharide, has previously been shown to exhibit immunostimulating activity . The authors investigated the in vivo and in vitro effects of mannuronan on murine haematopoiesis . In vivo, prophylactic (-24 h, intraperitoneal) administration of mannuronan enhanced survival of lethally irradiated mice from zero day 40 survivors (NaCl) to 20, 80 and 70% survival at 0.5, 1 and 2 mg/kg bw mannuronan, respectively . In vitro, primary stromal cultures stimulated with mannuronan produced high levels of interleukin(IL)-1, IL-6 and colony stimulating activity . Mannuronan alone did not have any colony stimulating activity on GM-CFC, BFU-E, Mix-CFC or HPP-CFC progenitors in clonogenic assays, but acted synergistically with suboptimal amounts of growth factors on GM-CFC, Mix-CFC and HPP-CFC colony formation . Limiting dilution analysis showed that 1 of 423 bone marrow cells formed colonies in response to suboptimal GM-CSF plus mannuronan compared to 1 of 592 for suboptimal GM-CSF alone . The primitive Lin-Sca-1+ haematopoietic progenitors showed increased day 10 colony size in the presence of mannuronan in single cells assays . These stimulating effects of mannuronan on haematopoiesis may prove to have clinical importance. J Med Microbiol, 1997 Jun, 46(6), 471 - 8 Role of haemolytic and non-haemolytic phospholipase C from Pseudomonas aeruginosa in interleukin-8 release from human monocytes; Konig B et al.; A massive accumulation of neutrophils, mainly due to enhanced interleukin-8 (IL-8) levels, is believed to contribute to the deleterious effects of Pseudomonas aeruginosa lung infection, e.g., in cystic fibrosis (CF) . Antibodies to phospholipase C, an exoenzyme of P . aeruginosa, are detected early and at high levels in CF patients . However, P . aeruginosa produces at least two types of phospholipase C (PLC), one haemolytic (PLC-H) and the other non-haemolytic (PLC-N), both with mol.wts of c . 77 kDa . Experiments were performed to evaluate the potential contribution of P . aeruginosa PLC to neutrophil accumulation during infection . Therefore, P . aeruginosa PLC-H and PLC-N were compared with regard to IL-8 generation from human monocytes . Purified PLC-H as well as culture supernates (mol.wt > 50 kDa) of a P . aeruginosa strain capable of producing both PLC-H and PLC-N, and mutant strains deficient in the production of one or other phospholipase, or both, were examined . Purified PLC-H (only at low concentrations up to 1 unit/4 x 10(5) monocytes), induced a dose-dependent increase in IL-8 release and IL-8-specific mRNA expression over that of unstimulated cells (at 4-, 12- and 24-h incubation times) . Higher concentrations of PLC-H led to a decrease in IL-8 release and IL-8-specific mRNA expression . These findings were confirmed by the results obtained with the supernates of cultures of mutant strains of P . aeruginosa PAO1 that produced either a PLC-H or PLC-N or neither . Stimulation and inhibition of IL-8 release and mRNA expression were associated with a culture supernate fraction of mol . wt > 50 kDa and containing PLC-H . These results contribute to the understanding of the role of both P . aeruginosa PLC in IL-8 generation during their interaction with human monocytes. Biomed Pept Proteins Nucleic Acids, 1995, 1(3), 141 - 8 Development of an anti-adhesive vaccine for Pseudomonas aeruginosa targeting the C-terminal region of the pilin structural protein; Sheth HB et al.; This study describes the development of passive and active vaccines directed at the Pseudomonas aeruginosa pilus adhesin . Passive immunization studies were carried out with P . aeruginosa strain K pilus-specific (PK3B, PK99H) and cross-reactive (PAK-13) monoclonal antibodies (MAbs) . When A.BY/SnJ mice were passively immunized with a pilus-specific MAb (PK99H), which inhibited pilus-mediated adherence to respiratory epithelial cells, mice challenged with 5 x LD 50 of P . aeruginosa were completely protected while mice were not protected when animals were passively immunized with a pilus specific MAb (PK3B), which did not inhibit pilus adherence to epithilial cells . MAb PAK-13 was found to cross-react with the C-terminal portion of pili of different strains of P . aeruginosa . When mice were passively immunized with MAb PAK-13, subsequent challenge with KB7 (3 x LD50), PAO (8 x LD50) and PAK (3 x LD50) strains of P . aeruginosa resulted in a 70%, 60% and 90% protection of the mice, respectively . MAb PK99H has been previously shown to recognize a linear antigenic epitope consisting of the sequence DEQFIPK . This epitopic peptide was conjugated to protein carriers using different coupling strategies . Use of an appropriate adjuvant and the correct conjugation strategy were critical for raising high affinity antipeptide antisera . In a comparison of Freund's, alum, and Adjuvax, as adjuvants for a peptide-tetanus toxoid conjugate vaccine, highest titers for the synthetic peptide component of the conjugate were obtained with Adjuvax, while highest titers for the carrier protein components were obtained with Freund's . Of the four peptide-conjugates used in this study, only the C-terminal conjugated peptide failed to produce antibodies that bind to native antigen and did not protect mice in active immunization experiments (no survivors at 80 h in the mouse infection model) . Conformationally restricted peptide conjugates in which the peptide was conjugated to the carrier at both ends provided better protection in mice challenged with lethal doses of P . aeruginosa than either N- or C-terminal linked peptide-conjugates . The pilus adhesin plays a critical role in P . aeruginosa pathogenesis and this is an excellent vaccine target for either active or passive immunization strategies. Microb Pathog, 1997 Oct, 23(4), 249 - 55 Pseudomonas aeruginosa entry into Caco-2 cells is enhanced in repairing wounded monolayers; Pereira SH et al.; Human respiratory cells participating in the repair of epithelial wounds have been shown to be highly susceptible to Pseudomonas aeruginosa adherence . To ascertain whether such susceptibility is a common feature of different repairing epithelial cells, Caco-2 cell monolayers were chemically injured, reincubated for 48 h to partially repair and exposed to bacteria . Cells edging the wounds that spread and migrate to re-establish cell confluence were called 'repairing cells' while cells far from the wounds were called 'non-repairing cells' . By light microscopy, bacteria were seen to adhere to and to enter into both repairing and non-repairing cells . The percentage of intracellular bacteria in repairing cells was significantly higher than in non-repairing cells . The higher susceptibility of repairing monolayers to bacterial entry was confirmed by the gentamicin exclusion assay . P . aeruginosa entry into Caco-2 cells was greatly enhanced in non-injured confluent monolayers treated with EDTA to disrupt intercellular junctions . As tight junction disfunctions have been described during the wound repair process, we speculate that exposure of basolateral receptors to bacterial ligands may account for the enhancement of P . aeruginosa internalization by repairing monolayers . J Surg Res, 1997 Sep, 72(1), 70 - 7 OPC-6535, a superoxide anion production inhibitor, attenuates acute lung injury; Bloomfield GL et al.; A large body of evidence has demonstrated that inhibition of the neutrophil's oxidant burst attenuates sepsis-induced acute lung injury . The present study sought to evaluate the ability of OPC-6535, a superoxide anion production inhibitor, to attenuate sepsis-induced acute lung injury . Four groups of swine were anesthetized, ventilated, and studied for 5 hr . Following surgical preparation, control (n = 10) and OPC-control (n = 2) animals received a 1-hr infusion of sterile saline . Sepsis was induced with a 1-hr intravenous infusion of live Pseudomonas aeruginosa . Untreated septic animals (n = 10) received no treatment . Animals treated with OPC-6535 (n = 6) received a 1 mg/kg bolus of OPC-6535 15 min prior to initiation of the bacterial infusion . Changes in systemic and pulmonary hemodynamics, arterial oxygen tension, bronchoalveolar lavage protein and neutrophil content, neutrophil integrin expression, neutrophil oxidant burst, and lung myeloperoxidase content were used as outcome measures . Treatment with OPC-6535 significantly reduced acute lung injury, as indicated by improved bronchoalveolar lavage protein and neutrophil content, resulting in a significant improvement in arterial oxygenation . Treatment with OPC-6535 failed to prevent the development of pulmonary hypertension and systemic hypotension . Neutrophils from animals with both treated and untreated sepsis exhibited significant up-regulation of CD18 and production of increased levels of oxidants, indicating significant activation when compared to neutrophils from control animals . Although animals treated with OPC-6535 produced 25% less superoxide anion than untreated septic animals, this decrease was not statistically significant . Treatment of animals with OPC-6535 prior to the onset of sepsis produced significant protection against acute lung injury but failed to attenuate hemodynamic derangements associated with sepsis. Cytokine, 1997 Oct, 9(10), 763 - 9 Adverse effects of tumour necrosis factor in cyclophosphamide-treated mice subjected to gut-derived Pseudomonas aeruginosa sepsis; Matsumoto T et al.; To evaluate the role of tumour necrosis factor (TNF) in gut-derived sepsis, mice were given Pseudomomas aeruginosa strain D4 by bacterial suspension in their drinking water during which time ampicillin (200 mg/kg) was given to disrupt the normal indigenous bacterial flora . Cyclophosphamide was additionally administered to induce bacterial translocation of the P . aeruginosa that had colonized the gastrointestinal tract, and thereby to cause gut-derived sepsis . In this model, TNF-alpha was detected in serum from the next day after the second cyclophosphamide administration, increasing to level of 3 ng/ml in lethal conditions . Average serum TNF-alpha level was significantly higher in mice with bacteraemia than in those without bacteraemia . Treatment with 0.8 microg/kg of recombinant human TNF-alpha (rhTNF-alpha) did not affect the mortality, whereas administration of either 4 and 20 microg/kg of rhTNF-alpha significantly increased the mortality rate in comparison with saline-treated mice . Bacterial counts in liver and blood were significantly higher in 20 microg/kg of rhTNF-alpha treated mice than in saline-treated mice . Treatment with murine anti-TNF-alpha monoclonal antibody significantly reduced the mortality from septic infection . We conclude that TNF-alpha may facilitate bacterial translocation and causes deterioration of gut-derived sepsis due to P . aeruginosa in mice . Anal Biochem, 1997 Oct 15, 252(2), 277 - 85 Inhibition, reactivation, and determination of metal ions in membrane metalloproteases of bacterial origin using high-performance liquid chromatography coupled on-line with inductively coupled plasma mass spectrometry; Leopold I et al.; High-performance liquid chromatography coupled on-line with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was used for the characterization of metal ions in several metalloproteases of bacterial origin . The different components of the bacterial extracts were separated on a size-exclusion column . The eluent of the HPLC system was continuously transported to the ICP-MS system for rapid, reproducible, and sensitive analyses of trace elements in the metalloproteases . Two different membrane proteases from Bacillus cereus and Pseudomonas aeruginosa were characterized to be zinc metalloproteases using enzymological methods and HPLC-ICP-MS . The zinc content was determined to be three molecules of zinc per protein molecule for the B . cereus protease and one molecule of zinc per protein molecule for the P . aeruginosa protease . For another purified protease, a periplasmic alanyl aminopeptidase of P . aeruginosa, the lack of protein-bound metal ions could be clearly determined-a confirmation that this main aminopeptidase of P . aeruginosa belongs to the cysteine protease family . The presence of nonionic detergents can influence the distribution of trace elements during the HPLC separation . Therefore, the use of these substances should be avoided during enzyme purification for metal analyses or they should be exchanged later for zwitterionic and ionic detergents with more strongly dissociating properties . Appl Environ Microbiol, 1997 Oct, 63(10), 4075 - 8 Cadmium removal by a new strain of Pseudomonas aeruginosa in aerobic culture; Wang CL et al.; A fluorescent pseudomonad (strain CW-96-1) isolated from a deep-sea vent sample grew at 30 degrees C under aerobic conditions in an artificial seawater medium and tolerated cadmium concentrations up to 5 mM . After 140 h, strain CW-96-1 removed > 99% of the cadmium from solution . Energy dispersive microanalysis revealed that the cadmium was removed by precipitation on the cell wall; sulfide production was confirmed by growth on Kligler's agar . Based on 16S ribosomal DNA sequencing and fatty acid analysis, the microorganism is closely related to Pseudomonas aeruginosa. Eur J Clin Microbiol Infect Dis, 1997 Aug, 16(8), 575 - 80 Bactericidal effect of pefloxacin and fosfomycin against Pseudomonas aeruginosa in a rabbit endocarditis model with pharmacokinetics of pefloxacin in humans simulated in vivo; Bugnon D et al.; The bactericidal activity of pefloxacin and fosfomycin alone and in combination against Pseudomonas aeruginosa was evaluated in an experimental rabbit endocarditis model after 24 h of treatment . Two strains with intermediate susceptibility to pefloxacin and good susceptibility to fosfomycin were tested . The serum kinetics obtained during administration of 400 mg every 12 h in humans were simulated in the animals using computer-controlled variable-flow infusion . Fosfomycin was administered as a continuous infusion at a constant flow, allowing a steady-state concentration of 47.4 +/- 11.9 mg/ml to be reached in serum . In valvular vegetations, pefloxacin was less bactericidal than fosfomycin, and in combination treatment, it reduced (but did not abolish) the bactericidal effect of fosfomycin . The duration of the pretreatment interval (12-48 h) had a negative effect on the bactericidal activity of both drugs, especially that of fosfomycin. J Basic Microbiol, 1997, 37(4), 281 - 6 Surface-active properties of rhamnolipids from Pseudomonas aeruginosa GS3; Patel RM et al.; Pseudomonas aeruginosa GS3 produced rhamnolipid biosurfactants during growth on carbohydrates, higher chain length n-alkanes and l-alkenes, petroleum crude oil and vegetable oils . With glucose as the substrate, maximum surfactant production (0.44 g/l) was observed during the stationary phase of growth . Partially purified rhamnolipids showed excellent surface-active properties in terms of reduction in the interfacial tension between them and a variety of hydrocarbons, hydrocarbon mixtures and vegetable oils and formation of stable emulsion. J Basic Microbiol, 1997, 37(4), 269 - 79 Purification and properties of methanol dehydrogenase from Methylocystis sp . GB 25; Grosse S et al.; Methanol dehydrogenase (MDH) from Methylocystis sp . GB 25, which belongs to the group II of methanotrophic bacteria, is able to catalyse the oxidation of methanol to formate directly . The enzyme was purified 20-fold by a 5 step procedure to electrophoretic homogeneity . After cell disruption by French press, about 95% of MDH-activity was found in the soluble fraction . The relative molecular mass of the native enzyme has been estimated to be 122 kDa by gel filtration and 115 kDa by the method of Hedrick and Smith (1968) . It seems to be composed of two identical subunits with a relative molecular mass of 62 kDa (estimated by SDS gel electrophoresis) . The isoelectric point was found to be about 8.3 . The amino terminal sequence shows a strong similarity to the alpha-chain of MDH from the facultative methylotrophic bacterium Methylobacterium extorquens AM1 . PQQ, the probable prosthetic group of MDH, could be detected in the supernatant of the culture by using the apoenzyme of a membrane-bound glucose dehydrogenase from Pseudomonas aeruginosa but not absolutely in the absorption spectra of the enzyme after DEAE-chromatography . The purified MDH has an optimum activity at pH 9.0 and at 45 degrees C . MDH of Methylocystis sp . GB 25 oxidises only primary alcohols from methanol to heptanol and aldehydes from formaldehyde to propionaldehyde and the glutaraldehyde, respectively . The estimated Km-values show no dependence upon the chain length of substrates. Arzneimittelforschung, 1997 Sep, 47(9), 1061 - 4 Pseudomonas aeruginosa infection in embryonated hen's eggs . An alternative in vivo model for the screening of antibacterial substances; Hartl A et al.; Embryonated hens' eggs can be reliably infected by Pseudomonas aeruginosa in laboratory experiments . Therapy tests with the antibiotics azlocillin (CAS 37091-66-0) and gentamicin (CAS 13291-74-2) on this type of infected hens' eggs demonstrate that this test system offers a realistic alternative to septic experiments with small laboratory rodents . Chick embryos survive a lethal Pseudomonas infection when azlocillin or gentamicin in a relevant therapeutic dose are administered immediately after the infective agent . The use of Pseudomonas infected chick embryos in the screening for new antiinfectives allows, therefore, a considerable reduction of the number of laboratory rodents required. Proc Natl Acad Sci U S A, 1997 Oct 28, 94(22), 12088 - 93 Cystic fibrosis transmembrane conductance regulator is an epithelial cell receptor for clearance of Pseudomonas aeruginosa from the lung; Pier GB et al.; The cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride ion channel, but its relationship to the primary clinical manifestation of CF, chronic Pseudomonas aeruginosa pulmonary infection, is unclear . We report that CFTR is a cellular receptor for binding, endocytosing, and clearing P . aeruginosa from the normal lung . Murine cells expressing recombinant human wild-type CFTR ingested 30-100 times as many P . aeruginosa as cells lacking CFTR or expressing mutant DeltaF508 CFTR protein . Purified CFTR inhibited ingestion of P . aeruginosa by human airway epithelial cells . The first extracellular domain of CFTR specifically bound to P . aeruginosa and a synthetic peptide of this region inhibited P . aeruginosa internalization in vivo, leading to increased bacterial lung burdens . CFTR clears P . aeruginosa from the lung, indicating a direct connection between mutations in CFTR and the clinical consequences of CF. Ugeskr Laeger, 1997 Sep 22, 159(39), 5786 - 90 {Cystic fibrosis and chronic Pseudomonas aeruginosa infection . Possibilities for immunologic prophylaxis and therapy}; Bisgaard AT et al.; Cystic fibrosis is an autosomal recessive disease, characterised by chronic pulmonary infections, pancreatic insufficiency and increased electrolyte content of sweat . Cystic fibrosis is diagnosed in one out of 4761 children below the age of 15 years . Pulmonary infection was previously caused by Staphylococcus aureus, but after the introduction of penicillin, the mortality was reduced from 61% to 20% within the first five years of life . Today chronic pulmonary infection is primarily caused by Pseudomonas aeruginosa . P . aeruginosa infection produces an immunologically conditioned destruction of the pulmonary tissue, leading to fatal bronchiectasis . P . aeruginosa develops resistance against most antibiotics and chemotherapeutic agents except colistin . Immunological aspects concerning active and passive immunisation are discussed in the article . Until today no useable vaccine has been found, but several candidates are subjects of research. Arch Otolaryngol Head Neck Surg, 1997 Oct, 123(10), 1057 - 60 Chronic otitis media treated topically with ciprofloxacin or tobramycin; Fradis M et al.; OBJECTIVE: To evaluate the efficacy of ciprofloxacin compared with tobramycin and placebo ear drops in the treatment of chronic suppurative otitis media without cholesteatoma . DESIGN: Sixty ears (in 51 patients) were randomly divided into 3 treatment groups: ciprofloxacin hydrochloride, tobramycin, and placebo interventions . SETTING: The otolaryngology department of a university teaching hospital . INTERVENTION: All ears were treated topically for 3 weeks . MAIN OUTCOME MEASURES: Each patient received a small, numbered bottle and was instructed to instill 5 drops 3 times daily for 3 weeks . The final clinical and bacteriologic assessment was made after 3 weeks . RESULTS: The organism most commonly isolated from the ear discharge was Pseudomonas aeruginosa . Its sensitivity to ciprofloxacin and tobramycin was 94.2% and 70.6%, respectively . The clinical response was 78.9%, 72.2%, and 41.2% in the ciprofloxacin, tobramycin, and placebo groups, respectively . The bacteriologic response rate was 66.7% for the ciprofloxacin and tobramycin groups and 20% for the placebo group . Treatment with ciprofloxacin ear drops seemed to be as effective as treatment with tobramycin . CONCLUSION: While the lack of ototoxicity of ciprofloxacin was not tested in our study, this treatment may be considered as a potential topical therapy for cases of chronic suppurative otitis media. J Laryngol Otol, 1997 Aug, 111(8), 760 - 2 Cilia from a cystic fibrosis patient react to the ciliotoxic Pseudomonas aeruginosa II lectin in a similar manner to normal control cilia--a case report; Adam EC et al.; The ciliary beat frequency measurements taken from a nasal polyp from a cystic fibrosis patient were similar to that of the control nasal polyps . The addition of a ciliotoxic lectin produced by Pseudomonas aeruginosa stopped the beating of the cilia as in the controls . This reaction could be blocked by the pre-incubation of the lectin with its inhibitor fucose . As in the control, the addition of fucose after the cilia had slowed resulted in a return to normal ciliary beating within 24 hours . This shows that the delta F508 CF mutation observed in this patient does not affect ciliary beating and suggests that treatment with fucose in the early stages of a Pseudomonas aeruginosa infection could be advantageous for cystic fibrosis patients. Rinsho Byori, 1997 Jun, 45(6), 581 - 4 {Rapid identification of four bacterial species by proton magnetic resonance spectroscopy}; Ohara T et al.; In the present study, we applied proton nuclear magnetic resonance (1H NMR) spectroscopy to distinguish between four bacterial species: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae . Because of differences in the composition of their cell wall and cytoplasmic constituents, individual bacterial species exhibited characteristic spectra except for K . pneumoniae . Reproducibility was satisfactory in the quantitative studies for chemical shift, intensity of signal and integrated intensity . The turnaround time of the test was only about 40 minutes . 1H NMR could be a new powerful tool for strain identification. J Antimicrob Chemother, 1997 Sep, 40(3), 371 - 6 Altered denA and anr gene expression in aminoglycoside adaptive resistance in Pseudomonas aeruginosa; Karlowsky JA et al.; Adaptive resistance to aminoglycoside killing and cytoplasmic accumulation occurs in cultures of originally susceptible Pseudomonas aeruginosa following an initial incubation with aminoglycoside . Anaerobiosis has also been reported to reduce bacterial killing and limit cytoplasmic aminoglycoside accumulation . We hypothesized that a common mechanism may facilitate reduced bacterial killing and aminoglycoside accumulation in both cases . Northern blot analysis of P . aeruginosa adaptively resistant to gentamicin demonstrated increased mRNA levels of both denA (nitrite reductase), which facilitates terminal electron acceptance in the anaerobic respiratory pathway, and its regulatory protein, ANR, in the absence of promoter DNA sequence changes, when compared with controls . These observations suggested that P . aeruginosa may regulate the expression of genes in its anaerobic respiratory pathway in response to aminoglycosides and may explain, at least partially, P . aeruginosa adaptive resistance to aminoglycosides. J Antimicrob Chemother, 1997 Sep, 40(3), 335 - 43 Potentiation of beta-lactams against Pseudomonas aeruginosa strains by Ro 48-1256, a bridged monobactam inhibitor of AmpC beta-lactamases; Livermore DM et al.; Ro 48-1256 is a bridged monobactam inhibitor of Class C beta-lactamases, without significant antibacterial activity of its own . It was tested in combination with imipenem, meropenem, piperacillin and ceftazidime against Pseudomonas aeruginosa isolates, mutants and transconjugants . Imipenem was potentiated against all strains where the AmpC enzyme was inducible or derepressed, with its MICs being reduced from 1-2 mg/L to 0.25-0.5 mg/L for most isolates and from 8-16 mg/L to 1-2 mg/L for those lacking OprD (D2 porin) . Ro 48-1256 also abolished in-vitro selection of OprD-deficient mutants by imipenem . Ceftazidime and piperacillin were potentiated against strains derepressed for AmpC enzyme, but not against those where the enzyme remained inducible . For over 90% of AmpC-derepressed organisms, the MICs of ceftazidime were reduced to < or = 8 mg/L by Ro 48-1256 (4 mg/L) and those of piperacillin were reduced to < or = 16 mg/L . Meropenem, which is very stable to AmpC, was not potentiated . Ro 48-1256 did not potentiate piperacillin, ceftazidime or carbapenems when resistance was mediated by Class A, B or D enzymes . Tazobactam, tested as control, had opposite behaviour to Ro 48-1256, potentiating beta-lactams when resistance was due to Class A beta-lactamases but failing to reverse resistance mediated by AmpC . Ro 48-1256 could be used with imipenem to overcome resistance mediated by loss of OprD, or with ceftazidime or piperacillin to overcome derepression of AmpC. Biochemistry, 1997 Oct 21, 36(42), 12791 - 801 Solution secondary structure of a bacterially expressed peptide from the receptor binding domain of Pseudomonas aeruginosa pili strain PAK: A heteronuclear multidimensional NMR study; Campbell AP et al.; The C-terminal receptor binding region of Pseudomonas aeruginosa pilin protein strain PAK (residues 128-144) has recently been the target for the design of a synthetic peptide vaccine effective against multiple strains of P . aeruginosa infection . We have successfully cloned and bacterially expressed a 15N-labeled PAK pilin peptide spanning residues 128-144 of the intact PAK pilin protein, PAK 128-144(Hs145), and have determined the solution secondary structure of this peptide using heteronuclear multidimensional NMR spectroscopy . The oxidized recombinant peptide exists as a major (trans) and minor (cis) species in solution, arising from isomerization around the Ile138-Pro139 peptide bond . The pattern of NOEs, temperature coefficients, and coupling constants observed for the trans isomer demonstrate the presence of a type I beta-turn and a type II beta-turn spanning Asp134-Glu-Gln-Phe137 and Pro139-Lys-Gly-Cys142, respectively . This is in agreement with the NMR solution structure of the trans isomer of a synthetic PAK 128-144 peptide which showed a type I and a type II beta-turn in these same regions of the sequence {McInnes, C., Sonnichsen, F . D., Kay, C . M., Hodges, R . S., and Sykes, B . D . (1993) Biochemistry 32, 13432-13440; Campbell, A . P., McInnes, C., Hodges, R . S., and Sykes, B . D . (1995) Biochemistry 34, 16255-16268} . The pattern of NOEs, temperature coefficients, and coupling constants observed for the cis isomer also demonstrate a type II beta-turn spanning Pro139-Lys-Gly-Cys142, but suggest a second beta-turn spanning Asp132-Gln-Asp-Glu135 . Thus, the cis isomer may also possess a double-turn motif (like the trans isomer), but with different spacing between the turns and a different placement of the first turn in the sequence . The discovery of a double-turn motif in the trans (and cis) recombinant PAK pilin peptide is an extremely important result since the double turn has been implicated as a structural requirement for the recognition of both receptor and antibody . These results pave the way for future isotope-edited NMR studies of the labeled recombinant PAK pilin peptide bound to antibody and receptor, studies integral to the design of an effective synthetic peptide vaccine. Antimicrob Agents Chemother, 1997 Oct, 41(10), 2289 - 91 Mutations in the gyrA and parC genes in fluoroquinolone-resistant clinical isolates of Pseudomonas aeruginosa; Nakano M et al.; We determined partial sequences of the gyrA and parC genes of the fluoroquinolone-susceptible strain ATCC 27853 and 22 clinical isolates of Pseudomonas aeruginosa . While a single amino acid change in GyrA with or without a change in ParC was found in 14 isolates with decreased susceptibility to fluoroquinolones, 3 higher-level fluoroquinolone-resistant isolates had a double amino acid change in GyrA and a single amino acid change in ParC. Antimicrob Agents Chemother, 1997 Oct, 41(10), 2188 - 95 OXA-18, a class D clavulanic acid-inhibited extended-spectrum beta-lactamase from Pseudomonas aeruginosa; Philippon LN et al.; Clinical isolate Pseudomonas aeruginosa Mus showed resistance both to extended-spectrum cephalosporins and to aztreonam . We detected a typical double-disk synergy image when ceftazidime or aztreonam was placed next to a clavulanic acid disk on an agar plate . This resistance phenotype suggested the presence of an extended-spectrum beta-lactamase . Isoelectric focusing revealed that this strain produced three beta-lactamases, of pI 5.5, 7.4, and 8.2 . A 2.6-kb Sau3A fragment encoding the extended-spectrum beta-lactamase of pI 5.5 was cloned from P . aeruginosa Mus genomic DNA . This enzyme, named OXA-18, had a relative molecular mass of 30.6 kDa . OXA-18 has a broad substrate profile, hydrolyzing amoxicillin, ticarcillin, cephalothin, ceftazidime, cefotaxime, and aztreonam, but not imipenem or cephamycins . Its activity was totally inhibited by clavulanic acid at 2 microg/ml . Hydrolysis constants of OXA-18 (Vmax, Km) confirmed the MIC results . Cloxacillin and oxacillin hydrolysis was noticeable with the partially purified OXA-18 . The blaOXA-18 gene encodes a 275-amino-acid protein which has weak identity with all class D beta-lactamases except OXA-9 and OXA-12 (45 and 42% amino acid identity, respectively) . OXA-18 is likely to be chromosomally encoded since no plasmid was found in the strain and because attempts to transfer the resistance marker failed . OXA-18 is peculiar since it is a class D beta-lactamase which confers high resistance to extended-spectrum cephalosporins and seems to have unique hydrolytic properties among non-class A enzymes. Gene, 1997 Sep 15, 197(1-2), 405 - 12 First characterization of the phosphonoacetaldehyde hydrolase gene of Pseudomonas aeruginosa; Dumora C et al.; The phnX gene encoding the phosphonoacetaldehyde hydrolase (phosphonatase) from the Gram-negative bacterium Pseudomonas aeruginosa A237 has been cloned and its sequence determined . The open reading frame consists of 825 nucleotides specifying a protein of 275 amino acid residues corresponding to a predicted molecular weight of 29929 . The deduced amino acid sequence of PhnX did not share significant amino acid sequence similarity with any other polypeptide . Expression of the phosphonoacetaldehyde hydrolase coding sequence in Escherichia coli under control of the E . coli tac promoter resulted in the production of enzymatically active protein with an affinity constant similar to that of the phosphonoacetaldehyde hydrolase purified from P . aeruginosa A237 . This is the first nucleic sequence report of the phosphonoacetaldehyde hydrolase, an enzyme involved in the carbon-phosphorus bond cleavage. Indian Pediatr, 1997 Apr, 34(4), 297 - 302 Neonatal nosocomial infection: profile and risk factors; Pawa AK et al.; OBJECTIVE: To determine the incidence and risk factors for neonatal nosocomial infections . DESIGN: Cohort study . SETTING: Tertiary care Teaching Hospital . METHODS: Hospital born neonates transferred to the neonatal unit after birth and available in the unit 48 hours later comprised the cohort for the surveillance . Detailed maternal, intrapartum and neonatal variables were recorded . Risk factors for nosocomial infection were analyzed by both univariate and multiple logistic regression methods . RESULTS: One hundred and thirty-four neonates were enrolled in the cohort . The overall nosocomial infection rate was 16.8/1000 patient days . Device associated infection rate was 11.9/1000 device days . Multidrug resistant Klebsiella species was the commonest organism causing nosocomial septicemia and pneumonia followed by Pseudomonas aeruginosa . The risk factors detected to be significantly associated with infection on multiple logistic regression analyses were a birth weight < 1500 g (OR 3.3) and assisted ventilation > 72 h (OR 14.2) . CONCLUSIONS: Very low birth weight (VLBW) neonates, especially those undergoing interventions such as mechanical ventilation are at the greatest risk for infection and death . Therefore, strict protocol for asepsis must be adhered to when handling these high risk infantsPIP: The incidence and risk factors for neonatal nosocomial infection were investigated in a cohort study of 134 hospital-born infants transferred to a neonatal unit in New Delhi, India, after birth and observed for up to 72 hours . 22 of the 134 infants developed nosocomial infections . The median age at diagnosis was 184 hours . In 16 of these infants, both sepsis screen and blood culture were positive . Septicemia was diagnosed in 21 neonates; 11 had associated pneumonia and four had soft tissue infection . Multiresistant Klebsiella species was the infectious agent in 68% of cases . The overall nosocomial infection rate was 16.8/1000 patient-days and the device-associated infection rate was 11.9/1000 device-days . Factors significantly associated with neonatal nosocomial infection in the univariate analysis were low birth weight, prematurity, vaginal delivery, hyaline membrane disease, assisted ventilation, and use of peripheral venous and umbilical vascular catheters . In the final multivariate analysis, only birth weight under 1500 g (odds ratio, 3.3) and assisted ventilation for more than 72 hours (odds ratio, 14.2) remained significant risk factors . It was observed in 122 random observations in this hospital that 15-18% of nurses and residents failed to adhere to adequate hand-washing techniques . Strict adherence to aseptic protocols in neonatal units is essential to keep infection rates under control . Acta Microbiol Immunol Hung, 1997, 44(2), 119 - 31 Biostatic and biocidal activities of water-thinnable polyesteramide compositions containing 8-hydroxyquinoline; Abd el-Hai F et al.; Various water soluble polyesteramide compositions are prepared by solvent technique containing a stoichiometric amount of 8-hydroxyquinoline as preservative against microbiological attack . Mechanism of action of 8-hydroxyquinoline against Pseudomonas aeruginosa ATCC 10145 is discussed and the studies showed promising results as biostatic and biocidal coatings . Preparation of water soluble polyesteramides via solvent process by using a new technique is another aspect taken into consideration. Infect Immun, 1997 Oct, 65(10), 4146 - 51 Protective efficacy of antibodies to the Staphylococcus aureus type 5 capsular polysaccharide in a modified model of endocarditis in rats; Lee JC et al.; The protective efficacy of antibodies to the Staphylococcus aureus type 5 capsular polysaccharide (CP5) was examined in a modified model of catheter-induced endocarditis . Rats were catheterized by surgically passing a polyethylene catheter through the right carotid artery and aortic valve into the left ventricle . The following day, the rats were injected by the intraperitoneal (i.p.) route with immunoglobulin G (IgG) purified from nonimmunized rabbits or from rabbits immunized with a conjugate vaccine composed of CP5 and CP8 linked covalently to recombinant Pseudomonas aeruginosa exotoxoid A . One day after passive immunization, the animals were challenged i.p . with one of three serotype 5 S . aureus isolates (strain Reynolds, Lowenstein, or VP) or nontypeable strain 521 . Protection was evaluated by comparing quantitative cultures of blood, endocardial vegetations, and kidneys from control and immune animals . For experiments performed with S . aureus Reynolds and Lowenstein, rats given capsular antibodies (645 microg of CP5-specific IgG) showed a significantly (P < 0.05) lower prevalence of endocarditis than rats injected with nonimmune IgG . Similarly, quantitative cultures of the blood, kidneys, and aortic valve vegetations revealed that fewer S . aureus cells were recovered from rats given capsule-specific IgG than from rats administered nonimmune IgG . Rats challenged with strain VP were protected with 1.145 mg of CP5-specific IgG . Capsular antibodies did not protect against infection elicited by a nontypeable strain . These results demonstrate that capsular antibodies elicited by immunization with a polysaccharide-protein conjugate vaccine protect experimental animals against serotype 5 S . aureus infection in a modified model of endocarditis. Infect Immun, 1997 Oct, 65(10), 4061 - 7 Positive correlation of algD transcription to lasB and lasA transcription by populations of Pseudomonas aeruginosa in the lungs of patients with cystic fibrosis; Storey DG et al.; Pseudomonas aeruginosa causes a chronic infection in the lungs of individuals with cystic fibrosis . The P . aeruginosa isolates from these infections, when grown under laboratory conditions, characteristically are mucoid and produce low levels of the more destructive virulence factors, such as exotoxin A and the proteases . We wanted to determine if during the chronic lung infections associated with CF, the expression of alginate was inversely correlated to the expression of exotoxin A, elastase, and the LasA protease . We measured the transcript accumulation of algD, a marker of alginate, toxA, the structural gene for exotoxin A, lasB, the structural gene for elastase, and lasA, the structural gene for LasA protease, from the sputum bacterial populations of 23 patients . In the 131 samples tested, we frequently detected transcripts from the four genes . When a Spearman rank correlation analysis was done on the samples, we found no correlation between algD transcript accumulation and toxA transcript accumulation . This result suggested that toxA was regulated independently of algD . Curiously, we found a positive correlation between algD transcript accumulation and both lasB and lasA transcript accumulation levels . This correlation may not indicate a direct association between algD and either lasA or lasB . More likely, it indicates a common regulatory element in a cascade of regulators or a common environmental cue that triggers transcription. J Clin Microbiol, 1997 Oct, 35(10), 2706 - 8 Proficiency testing of clinical microbiology laboratories using modified decontamination procedures for detection of nontuberculous mycobacteria in sputum samples from cystic fibrosis patients . The Nontuberculous Mycobacteria in Cystic Fibrosis Study Group; Whittier S et al.; An improved decontamination method has been demonstrated to reduce overgrowth of mycobacterial media by Pseudomonas aeruginosa and allow the successful recovery of nontuberculous mycobacteria (NTM) from cystic fibrosis (CF) patients . Twenty microbiology laboratories participating in a multicenter investigation designed to determine the significance of NTM in CF patients were required to demonstrate proficiency in the incorporation of this improved method; this was accomplished by successful decontamination and culture workup of a panel of simulated sputum samples seeded with P . aeruginosa and various NTM . All laboratories successfully recovered NTM from samples with acid-fast bacillus (AFB) smear scores of 3+/4+ (i.e., 2 to 18 or > 18 organisms/field) . Low-inoculum samples (1+/2+ AFB smears {2 to 18 organisms in 100 or 10 fields}) were problematic in that processed specimens were often smear and/or culture negative. J Pharmacol Exp Ther, 1997 Sep, 282(3), 1565 - 71 The effect of rolipram, a type IV phosphodiesterase inhibitor, on Pseudomonas aeruginosa infection of respiratory mucosa; Dowling RB et al.; We have investigated the effect of rolipram, a type IV phosphodiesterase inhibitor, on Pseudomonas aeruginosa infection of the respiratory mucosa of an organ culture model and on the reduction in intracellular cAMP levels seen in human nasal epithelial cells incubated with P . aeruginosa culture filtrate . We have compared rolipram with salmeterol, a long-acting beta-2 agonist, and have also studied the effect of the two agents together . Infected organ cultures had significantly (P < or = .05) increased epithelial damage . Rolipram significantly (P < or = .05) reduced P . aeruginosa-induced epithelial damage and reduced the total number of bacteria adhering to the respiratory mucosa (P < or = .04) in a concentration-dependent manner, although neither rolipram nor salmeterol affected P . aeruginosa growth in broth cultures . Rolipram reduced P . aeruginosa-induced mucosal damage more than salmeterol (P < or = .03) . The effect of the two agents was neither additive nor synergistic . Rolipram, salmeterol and both agents together significantly (P < or = .01) increased intracellular cAMP levels in epithelial cells treated with P . aeruginosa culture filtrate . Rolipram alone increased cAMP more than salmeterol or both agents together (P < or = .01), probably because of an interaction between the two agents . These results suggest that agents that elevate intracellular cAMP protect the epithelium during bacterial infection . Rolipram is more effective than salmeterol in preventing P . aeruginosa-induced epithelial damage. Bioorg Med Chem, 1997 Aug, 5(8), 1685 - 94 Studies on 3'-quaternary ammonium cephalosporins--IV . Synthesis and antibacterial activity of 3'-(2-alkyl-3-aminopyrazolium) cephalosporins related to FK037; Ohki H et al.; The synthesis and in vitro antibacterial activity of 7 beta-{(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido} cephalosporins bearing various 2-alkyl-3-aminopyrazolium groups at the 3-position are described . Antibacterial activity against MRSA was affected by the nature of the substituent at the 2-position on the 3'-aminopyrazolium groups . Among the cephalosporins prepared in this study, 7 beta-{(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido}-3-{3-am ino-2-(2 -hydroxyethyl)-pyrazolio}methyl-3-cephem-4-carboxylate sulfate (23e, FK037) showed extremely potent broad-spectrum activity against both Gram-positive bacteria including MRSA, and Gram-negative bacteria including Pseudomonas aeruginosa . In particular, the in vivo activity against MRSA of FK037 was the highest of all the beta-lactam antibiotics tested. Enferm Infecc Microbiol Clin, 1997 Apr, 15(4), 200 - 2 {Otomastoiditis caused by Aspergillus in AIDS}; Martinez-Berriotxoa A et al.; BACKGROUND: Aspergillus otomastoiditis is an infrequent infection that occurs in most cases in immunocompromised hosts . Although fungal infections are common in AIDS patients, few cases of Aspergillus otomastoiditis have been reported . METHODS: Two clinical cases of AIDS patients with Aspergillus otomastoiditis are reported, and a review of the literature is performed . RESULTS: Clinical presentation in both cases was similar to those of other diseases involving middle and internal ear . Infection was linked to severe immunosuppression (C3 group) . CONCLUSIONS: Aspergillus otomastoiditis is an infrequent infection in AIDS patients . Different routes by which Aspergillus obtains access to the middle ear have been proposed (tympanogenic, meningogenic, hematogenous and direct spread from paranasal sinuses or external auditory canal) . Otorrhea, otalgia, hearing loss and facial nerve involvement are common findings . Bone destruction and invasion of brain or skull base may occur . CT or MRI are necessary to evaluate the extent of the disease . Etiologic diagnosis requires histopathologic confirmation on deep tissue biopsy or isolation from blood cultures or fistula exudates, because Aspergillus is a common saprophytic fungus in external auditory canal . Concurrent infections (i.e . Pseudomonas aeruginosa) frequently delay the correct diagnosis . Aggressive surgical resection and intravenous antifungal chemotherapy (amphotericin B or itraconazole) are the main therapeutic options . Outcome is poor as a consequence of severity, delay of etiologic diagnosis and difficulty of aggressive surgical approach in compromised patients . In patients with AIDS a low CD4 cell count would favour invasive Aspergillus infection, implying a worse outcome. Microbiol Immunol, 1997, 41(8), 601 - 8 Endogenous tumor necrosis factor (TNF) alpha mediates neutrophil accumulation at the mid-phase of a murine model of