Biochemistry, 1993 Mar 2, 32(8), 1965 - 75 Structural characterization of azurin from Pseudomonas aeruginosa and some of its methionine-121 mutants; Murphy LM et al.; Azurin from Pseudomonas aeruginosa and two mutants where the methionine ligand has been mutated have been studied in order to directly investigate the functional and structural significance of this ligand in the blue copper proteins . Reduction potentials, X-ray absorption fine structure (XAFS), electron paramagnetic resonance (EPR), and optical spectra are obtained in an attempt to provide a direct correlation between the spectrochemical properties and the immediate structure of this redox center. APMIS, 1993 Mar, 101(3), 207 - 25 Chronic Pseudomonas aeruginosa lung infection in normal and athymic rats; Johansen HK et al.; We have compared a chronic lung infection with Pseudomonas aeruginosa embedded in alginate beads in normal and athymic rats with an acute infection with free live P . aeruginosa bacteria . The following parameters were observed and described: mortality, macroscopic and microscopic pathologic changes, and antibody responses . The rats challenged with P . aeruginosa alginate beads experienced a generally more severe lung pathology and the antibody responses were more homogeneous with less dispersion as compared to the rats having free live P . aeruginosa bacteria . In general, manifestations were more severe in the athymic rats compared to the normal rats . It is, however, notable that the athymic rats developed similar microscopic lung manifestations as the normal rats when given a large number of P . aeruginosa in the beads, with dense accumulation of neutrophil granulocytes and microcolonies comparable to the lesions seen in cystic fibrosis (CF) patients . Early transitory IgM titers were demonstrated in both normal and athymic rats . Whilst athymic rats produced much lower IgG titers than the normal rats, presumably due to the absence of CD4+ cells, higher primary IgA titers were achieved . These two models in normal and athymic rats of the chronic lung infection resembling that seen in CF lungs make it possible to study the influence of the various components of the specific and nonspecific defense systems on the course of the chronic P . aeruginosa lung infection and to evaluate the effect of various immunization schedules and immunomodulatory drugs. Mikrobiol Zh, 1993 Mar-Apr, 55(2), 82 - 7 {The inhibition of the cellular immune response by Pseudomonas aeruginosa extracts}; Borisova VA et al.; Aquatic-phenol trichloroacetic and salt extracts of Pseudomonas aeruginosa have been studied for their effect on hypersensitivity of the delayed type to guinea pig antigen in mice . It is found that salt extracts of wild strains contain thermostable immunosuppressive factors which are of the lipid nature, have high molecular weight and can be inactivated by trichloroacetic acid and phenol . The salt extracts of museum strains as well as aquatic-phenol and trichloroacetic extracts obtained from wild and museum strains had no immunosuppressive activity. Kansenshogaku Zasshi, 1993 Mar, 67(3), 218 - 22 {Pleural washing with povidone-iodine for treatment of empyema}; Takayama K et al.; In this paper, we report two successful cases of empyema treated by pleural washing with povidone-iodine solution . In these two cases, empyema was caused by secondary infection of multi-drug resistant Pseudomonas aeruginosa . First, we replaced intrathoracic drainage tube and washed intrathoracic space with 500-1000 ml saline containing antibiotics (tobramycin, aztreonam) every 8 hours for 10-14 days . But, cultural studies of pleural effusion were positive even after this treatment . So, we tried pleural washing with warm povidone-iodine solution 1:20 diluted with saline every 8 hours . Surprisingly, after 3 days treatment, cultural studies of the pleural effusion became negative . This pleural washing method with povidone-iodine was very effective for treatment of empyema patients. Kansenshogaku Zasshi, 1993 Mar, 67(3), 202 - 6 {In vitro induction of chlorhexidine- and benzalkonium-resistance in clinically isolated Pseudomonas aeruginosa}; Kurihara T et al.; A study was made on the MIC distributions of chlorhexidine and benzalkonium chloride against clinically isolated 178 strains of Pseudomonas aeruginosa to find out the existence of strains resistant to those disinfectants and also on the in vitro induction of resistance to both drugs . The MIC of chlorhexidine gluconate was found to be distributed from 78 to 625 micrograms/ml with a single peak at 312 micrograms/ml . All 178 strains of clinical isolates were sensitive to chlorhexidine and none could be induced to become chlorhexidine resistant in vitro, suggesting that P . aeruginosa can not easily acquire chlorhexidine resistance . On the other hand, the MIC of benzalkonium chloride was distributed in two peaks; one peak was benzalkonium sensitive at 625 micrograms/ml (150 strains/178 strains: 84.3%) and the another peak was benzalkonium resistant at 5,000 micrograms/ml (28 strains/178 strains; 15.7%) . Six (4.0%) of the 150 benzalkonium sensitive strains acquired benzalkonium resistance by in vitro induction of resistance; the MIC of 5 strains increased from 625 micrograms/ml to 2,500 micrograms/ml and that of the residual 1 strain increased from 312 micrograms/ml to 1,250 micrograms/ml . However, no change of MIC was observed in 28 benzalkonium-resistant strains of clinically isolated P . aeruginosa by in vitro resistance induction . Strains with MIC more than 5,000 micrograms/ml could not be obtained at all . The results suggest that the benzalkonium resistance can be introduced in P . aeruginosa whereas the resistance-acquiring rate is low . These results suggest that chlorhexidine gluconate is the first choice for prevention of Pseudomonas infection in the hospital and benzalkonium is also useful in 0.5% solution is used. J Antimicrob Chemother, 1993 Mar, 31(3), 403 - 11 Effectiveness of netilmicin and tobramycin against Pseudomonas aeruginosa in vitro and in an experimental tissue infection in mice; Moffie BG et al.; The activity of netilmicin and tobramycin against Pseudomonas aeruginosa was assessed in vitro in the presence of constant and exponentially declining concentrations, and in mice in an experimental thigh infection . The activity in vitro at constant concentrations was expressed as the maximal killing rate (ER) during 3 h of exposure . On the basis of the quantitative relation between E(R) and the drug concentration, the numbers of cfu expected at consecutive times, at constant as well as at declining concentrations, were predicted . The relationship between observed numbers and predicted values of ERt were similar under both conditions for both drugs . On the same basis the numbers of cfu expected in the experimental thigh infection were predicted . There was indeed a significant linear relationship between observed numbers of cfu in homogenized muscle and the values predicted on the basis of the pharmacokinetics of the aminoglycosides, but the slope of this relationship was only 0.22 . There was no difference in this respect between the two antibiotics . It is concluded that the efficacy of netilmicin and tobramycin against P . aeruginosa is considerably less in vivo than in vitro, but the relation is about the same for the two drugs; therefore the slightly higher activity of tobramycin in vitro is relevant in the in-vivo situation. Mol Gen Genet, 1993 Mar, 237(3), 421 - 8 Nucleotide sequence of attP and cos sites of phage CTX and expression of cytotoxin in Pseudomonas aeruginosa PA158; Elsabbagh H et al.; The gene for Pseudomonas aeruginosa cytotoxin (CTX) has been found to be part of a temperate phage with a total size of 35.5 kb . We have investigated several DNA fragments of this phage for CTX production . For phage integration, the phage genome cohesive (cos) ends covalently associate with host DNA of strain PA158 . The cos ends and the CTX gene are found on a 3.4 kb EcoRI fragment B and are included in the 11 kb HindIII fragment A and the 8.5 kb BamHI fragment B of the phage DNA . The cos ends are 20 nucleotides long and are located at 338-357 nucleotides upstream of the CTX transcriptional initiation site . The phage attachment (attP) site is also present on the 3.4 kb EcoRI fragment B . The attP site consists of 34 bp and is located at 974-1007 nucleotides upstream of the CTX gene start site . Replication of the vegetative form of the phage is increased at 37 degrees C compared to that at 30 degrees C, while cytotoxin production in infected cells is similar at 30 degrees C and 37 degrees C . It can be concluded, therefore, that the integrated form of the CTX gene is responsible for CTX production . SDS-polyacrylamide gel electrophoresis (SDS-PAGE) showed ten proteins in purified phage preparations; however, CTX could not be detected on Western blots using an enzyme-linked immunofluorescence assay. J Infect, 1993 Mar, 26(2), 199 - 201 Retained Hickman catheter cuff as a source of infection; al-Wali WI et al.; Two cases of Pseudomonas aeruginosa infection complicating retained subcutaneous Hickman catheter cuffs are described . Foreign body-associated Pseudomonas infection is unlikely to respond to treatment with antibiotics alone . We therefore recommend that the cuff is removed at the same time as the Hickman catheter is pulled out so as to prevent future infection. J Infect, 1993 Mar, 26(2), 159 - 70 Septic shock in critically ill patients: aetiology, management and outcome; Dahmash NS et al.; Over a period of 28 months, 45 episodes of septic shock from 83 episodes of bacteraemia were studied prospectively to evaluate their clinical profile, management and outcome . Thirty-six patients were studied, the overall incidence of septic shock being 54.2% . Gram-negative organisms accounted for 23 (51.1%) of such episodes, Gram-positive 17 (37.8%), and three episodes were polymicrobial (6.7%) . The organisms isolated most frequently were Staphylococcus epidermidis (17.8%), Pseudomonas aeruginosa (13.3%), Escherichia coli and Klebsiella sp . (each 11.1%) . Coagulation abnormalities were detected in 32 episodes (78%) and disseminated intravascular coagulation (DIC) occurred in 11 of these with high mortality . The most common underlying conditions were respiratory, hepatic and renal failures . The majority of these patients received crystalloids, colloids, vasopressor drugs and blood . Swan-Ganz catheters (SGC) were inserted on eight occasions, the majority of times indicating a hyperdynamic circulatory response . The overall mortality was 40%, despite aggressive management and intensive care . The most important factor in reducing mortality is early detection of bacteraemia and prompt management of these patients. Mol Microbiol, 1993 Mar, 7(5), 657 - 67 Molecular analysis of a cytotoxin-converting phage, phi CTX, of Pseudomonas aeruginosa: structure of the attP-cos-ctx region and integration into the serine tRNA gene; Hayashi T et al.; The Pseudomonas aeruginosa ctx gene encoding cytotoxin is carried by a temperate phage phi CTX . The genome of phi CTX is a 35.5 kb double-stranded DNA with cohesive ends (cos) . It is unique in that the ctx gene and attP site of phi CTX exist very close to the respective cohesive ends . In this study, we determined the structure of this attP-cos-ctx region . The termini of phi CTX are 21-base 5' extended-single-stranded DNAs . The ctx gene is located 361 bp downstream of the left end (cosL) . The attP core sequence of 30 bp exists only 647 bp apart from the right end (cosR) . The attP-cos-ctx region contains six kinds of repeats and integration host factor-binding sequences and showed sequence-directed static bends, suggesting its potential to form a highly ordered structure . In addition, phi CTX was found to integrate into the serine tRNA gene which was mapped to the 43-45 min region on the P . aeruginosa chromosome. Int J Biochem, 1993 Mar, 25(3), 313 - 8 Occurrence of a 29 kDa polysaccharide in the slime layer of both smooth and rough strains of Pseudomonas aeruginosa; Christofidou M et al.; 1 . The lipopolysaccharide (LPS) and the extracellular products (slime) of a smooth, nonmucoid Pseudomonas aeruginosa strain (PAC IR) and its rough mutant (PAC 605) were subjected to a comparative biochemical analysis . 2 . Chemical and electrophoretic analyses suggested that the slime preparation of both strains are composed mainly of similar carbohydrate components which are different from those of the respective lipopolysaccharides . 3 . Chromatographic analysis of the two slime preparations on gel permeation HPLC columns revealed the presence of a major polysaccharide in both strains with an apparent molecular weight 29 kDa and a minor high molecular weight polysaccharide in the PAC IR strain. Antimicrob Agents Chemother, 1993 Mar, 37(3), 613 - 5 Reproducibility of the microdilution checkerboard method for antibiotic synergy; Rand KH et al.; We assessed the reproducibility of the microdilution checkerboard method for measuring antibiotic synergy . Five strains of Pseudomonas aeruginosa were tested with four antibiotic combinations by using 10 replicates each . Twenty-five percent of replicate sets gave discordant classification results (i.e., a 7:3 or worse split in categorization) . Determination of the individual MICs of each antibiotic alone was excellent; all 10 replicates were within 1 twofold dilution for 95% of the 80 sets of 10 replicates . The microdilution checkerboard method either should not be used or should be used with at least five replicates per determination, with > or = 80% agreement among the replicates required for classification. Antimicrob Agents Chemother, 1993 Mar, 37(3), 453 - 6 Mechanism of uptake of deglucoteicoplanin amide derivatives across outer membranes of Escherichia coli and Pseudomonas aeruginosa; Hancock RE et al.; Teicoplanin is a glycopeptide antibiotic which is ineffective against gram-negative bacteria because of its inability to penetrate the outer membrane . Removal of the sugar residues and attachment of polyamines to carbon 63 yielded two dibasic deglucoteicoplanin amides, MDL 62,766 (766) and MDL 62,934 (934), with moderate MICs for Escherichia coli (2 to 4 micrograms/ml) and Pseudomonas aeruginosa (8 to 32 micrograms/ml) compared with those of the monobasic teicoplanin aglycone (16 and > 1,024 micrograms/ml, respectively) . MICs were increased 16- to 32-fold by Mg2+ supplementation of Luria broth but not by Na+ supplementation at an equivalent ionic strength . Both 766 and 934 were capable of binding to P . aeruginosa lipopolysaccharide (LPS) at Mg(2+)-binding sites, as assessed by dansyl polymyxin displacement experiments . Furthermore, both compounds increased E . coli and P . aeruginosa outer membrane permeability to the hydrophobic fluorescent probe 1-N-phenylnaphthylamine (NPN), whereas the parent compounds teicoplanin aglycone and teicoplanin and the beta-lactam ceftazidime were totally ineffective . Addition of 1 mM Mg2+ blocked the increase in outer membrane permeability . Compound 766 had a lower MIC than 934 for both bacteria tested, bound to LPS with a higher affinity, and permeabilized outer membranes to NPN at lower concentrations . We propose that both deglucoteicoplanin amides exhibit increased gram-negative activity by virtue of their ability to access the self-promoted uptake pathway across the outer membrane. J Clin Microbiol, 1993 Mar, 31(3), 480 - 3 Pseudomonas aeruginosa folliculitis acquired through use of a contaminated loofah sponge: an unrecognized potential public health problem; Bottone EJ et al.; Pseudomonas aeruginosa folliculitis is a well-known entity that occurs among users of closed-cycle recreational water sources such as whirlpools, swimming pools, and hot tubs . In the absence of this epidemiologic link, isolated cases are difficult to diagnose . We encountered a patient who developed P . aeruginosa folliculitis subsequent to the use of a loofah sponge grossly contaminated with the same P . aeruginosa strain (serotype 10; pyocin type 1/a 4,b) that was recovered from her skin lesions . Furthermore, we demonstrated that sterile unused loofah sponges can serve as the sole growth-promoting substrate for P . aeruginosa . To obviate the potential public health problem of contaminated loofah sponges, it is strongly recommended that manufacturers append, and consumers adhere to, instructions as to the care of loofah sponges, which includes allowing the sponge to dry after use. J Clin Microbiol, 1993 Mar, 31(3), 475 - 9 Use of disinfectants to reduce microbial contamination of hubs of vascular catheters; Salzman MB et al.; The vascular catheter hub is a potential portal of entry for microorganisms that cause catheter-related sepsis . Thus, a reduction in catheter hub contamination might reduce the incidence of catheter-related sepsis . To develop a regimen suitable for reducing microbial contamination of the catheter hub, we experimentally contaminated catheter hubs and assessed the efficacies of disinfectant solutions . Catheter hubs were incubated overnight with suspensions of Staphylococcus epidermidis, Pseudomonas aeruginosa, or Candida parapsilosis . After removal of unattached microorganisms, the catheter hubs were swabbed by rotating cotton swabs dipped in 1% chlorhexidine, 1% chlorhexidine in 70% ethanol, 70% ethanol, 97% ethanol, or normal saline . Posttreatment swabs of the catheter hub were obtained and cultured quantitatively . The cleaning regimens containing ethanol were the most effective . Seventy percent ethanol was more effective than chlorhexidine and is likely to be the safest treatment . We conclude that cleaning of the catheter hub with disinfectant can dramatically reduce microbial contamination. Chemotherapy, 1993 Mar-Apr, 39(2), 105 - 11 Effect of subinhibitory concentrations of Ciprofloxacin and gentamicin on the adherence of Pseudomonas aeruginosa to Vero cells and voided uroepithelial cells; Zhanel GG et al.; The effect of subinhibitory concentrations (1/8 x, 1/16 x, 1/32 x MIC) of ciprofloxacin or gentamicin on the adherence of Pseudomonas aeruginosa to Vero cells and voided uroepithelial cells was studied using two different assay methods . Strains studied included both reference strains and clinical strains, including mucoid and nonmucoid isolates . Sub-MICs of ciprofloxacin decreased adherence to Vero cells and voided uroepithelial cells in 3 of 4 ciprofloxacin-susceptible nonmucoid isolates but not in ciprofloxacin-resistant or mucoid isolates . Sub-MICs of gentamicin significantly reduced adherence in 5 of 7 nonmucoid strains but not in mucoid strains . Gentamicin effect on adherence did not correlate with susceptibility to ciprofloxacin . We conclude that ciprofloxacin susceptibility determines the effect of sub-MICs of ciprofloxacin on P . aeruginosa adherence to Vero cells and voided uroepithelial cells . In addition, both the Vero cell assay and voided uroepithelial cell assay demonstrated similar results. Clin Infect Dis, 1993 Mar, 16(3), 404 - 6 Sinusitis due to Pseudomonas aeruginosa in patients with human immunodeficiency virus infection; O'Donnell JG et al.; Community-acquired sinusitis due to Pseudomonas aeruginosa developed in four patients with advanced human immunodeficiency virus (HIV) infection who had no local predisposing factors or neutropenia . Two persons were bacteremic . Combination antibiotic therapy and surgical drainage were necessary for adequate treatment . Ciprofloxacin-resistant strains were isolated possibly because of the chronic use of the drug as part of a treatment regimen for disseminated infection with Mycobacterium avium complex . Physicians treating patients with HIV infection must have an increased index of suspicion for P . aeruginosa as a causative agent of sinusitis. Clin Infect Dis, 1993 Mar, 16(3), 372 - 6 Outbreak of Pseudomonas aeruginosa infections in a surgical intensive care unit: probable transmission via hands of a health care worker; Widmer AF et al.; Pseudomonas aeruginosa was isolated from nine patients (16.2 isolations/1,000 patient-days) in a surgical intensive care unit during an outbreak in November 1990; this rate of isolation was three times higher than that noted previously on this unit . Three patients were infected with the same strain, as defined by identical serotypes, pyocin types, and contour-clamped homogeneous electric field (CHEF) electrophoresis patterns of digested genomic DNA . The hands of 80 health care workers were cultured, and a strain of P . aeruginosa identical to that infecting the three patients was isolated from the hands of a nurse providing care to all three . Environmental surfaces, medical devices, and ward stock supplies were cultured; none of these cultures yielded this strain . No clusters of infection with this strain or other strains of P . aeruginosa were observed after compliance with hand-washing and universal precautions was reemphasized . Thus this outbreak was linked to the carriage of P . aeruginosa on the hands of a health care worker . It could not be determined definitively whether this carriage was the source of the cluster or a consequence of it . However, the geographic and temporal clustering of carriage with an outbreak due to a strain of an apparently identical molecular type underlines the importance of routine hand washing between contacts with different patients. J Clin Invest, 1993 Mar, 91(3), 1079 - 87 Immune complexes from immunized mice and infected cystic fibrosis patients mediate murine and human T cell killing of hybridomas producing protective, opsonic antibody to Pseudomonas aeruginosa; Pier GB et al.; We examined the basis for the absence in cystic fibrosis (CF) patients of opsonic antibodies to the mucoid exopolysaccharide (MEP) antigen surrounding Pseudomonas aeruginosa that infect these patients . Opsonic antibodies to MEP are found in sera of the minority of CF patients that remain noncolonized into the second to fourth decades of life and protect rodents from chronic P . aeruginosa endobronchial infections . High titers of nonopsonic antibodies to MEP are found in P . aeruginosa-infected CF patients . Immunization of mice with doses of MEP that provoke only nonopsonic antibodies elicited CD3+, CD8+, T cell receptor alpha beta receptor+, major histocompatibility complex-unrestricted cytotoxic lymphocytes specific for hybridoma cells producing opsonic but not nonopsonic antibodies . Cytotoxicity was dependent on immune complexes on the surface of the T cells . Normal murine T cells could be activated by concanavalin A and sensitized with immune complexes for cytotoxic killing of hybridoma targets . CF patients infected with P . aeruginosa had serum immune complexes that sensitized concanavalin A-activated human T cells to kill murine hybridoma cells producing opsonic but not nonopsonic antibody . These results could explain the absence in infected CF patients of MEP-specific opsonins, an occurrence that accompanies the persistence of this infectious state. J Bacteriol, 1993 Mar, 175(6), 1605 - 11 Synthesis of lipopolysaccharide O side chains by Pseudomonas aeruginosa PAO1 requires the enzyme phosphomannomutase; Goldberg JB et al.; We have cloned a lipopolysaccharide (LPS) biosynthetic gene from Pseudomonas aeruginosa PAO1 that complements the defect in the production and incorporation of LPS O side chains in the LPS-rough strain AK1012 . This gene was characterized by pulsed-field gel electrophoresis, deletion and restriction mapping of the cloned DNA, and biochemical analysis of the protein product . The cloned DNA was found to map to the 7-to-11-min region of the P . aeruginosa chromosome, and the gene needed for complementation of the LPS-rough phenotype was contained on a 2.6-kb HindIII-SacI fragment . This same size restriction fragment contains the alginate gene algC, which encodes the enzyme phosphomannomutase (PMM) and also maps to this region of the P . aeruginosa chromosome . The LPS-rough strain AK1012 was deficient in PMM activity, and this activity was restored to parental levels when the cloned gene was transferred to strain AK1012 . In addition, the cloned gene could complement the PMM deficiency in the algC mutant strain 8858, and the cloned algC gene could restore the LPS-smooth phenotype to strain AK1012 . These results indicate that the gene we have cloned is equivalent to the alginate gene algC . We designate this gene pmm to emphasize that it encodes the enzyme PMM, which has been shown to be essential for alginate production, and we demonstrate that PMM activity is required for the LPS-smooth phenotype in P . aeruginosa PAO1. J Bacteriol, 1993 Mar, 175(5), 1303 - 8 A mutation in algN permits trans activation of alginate production by algT in Pseudomonas species; Goldberg JB et al.; Conversion of the mucoid phenotype, which results from the production of the exopolysaccharide alginate, is a feature typical of Pseudomonas aeruginosa strains causing chronic pulmonary infections in patients with cystic fibrosis . In this study, we further characterized a recombinant plasmid, called pJF15, that contains DNA from the 65- to 70-min region of the chromosome of mucoid P . aeruginosa FRD1 and has loci involved in alginate conversion . Plasmid pJF15 complements algT mutations in trans and confers the mucoid phenotype in cis following gene replacement . However, the phenotype of nonmucoid P . aeruginosa carrying pJF15 is unchanged . Here we report the identification of a locus immediately downstream of algT, called algN, that may be a negative regulator that blocks algT from activating alginate production . Inactivation of algN by transposon Tn501 insertion allowed algT to stimulate alginate production in trans . The DNA sequence of this region identified an open reading frame that predicts an algN gene product of 33 kDa, but no homology was found to other proteins in a sequence data base . Clones of algT in which algN was deleted caused the activation of alginate biosynthesis in transconjugants of several P . aeruginosa strains . DNA containing algT was shown to hybridize to the genomes of several Pseudomonas species, including P . putida, P . stutzeri, and P . fluorescens . Transconjugants of these species carrying algT DNA (with a deletion of algN) from pJF15 showed a mucoid phenotype and increased production of uronic acid-containing polymers that resembled alginate. J Bacteriol, 1993 Mar, 175(5), 1257 - 63 Regulation of pyocin genes in Pseudomonas aeruginosa by positive (prtN) and negative (prtR) regulatory genes; Matsui H et al.; Most strains of Pseudomonas aeruginosa produce various types of bacteriocins (pyocins), namely, R-, F-, and S-type pyocins . The production of all types of pyocins was shown to be regulated by positive (prtN) and negative (prtR) regulatory genes . The prtN gene activates the expression of various pyocin genes, probably by the interaction of its product with the DNA sequences conserved in the 5' noncoding regions of the pyocin genes . The prtR gene represses the expression of the prtN gene, and its product, predicted from the nucleotide sequence, has a structure characteristic of phage repressors and seems to be inactivated by the RecA protein activated by DNA damage . A model for the regulation of the pyocin genes is proposed. Proc Soc Exp Biol Med, 1993 Mar, 202(3), 377 - 83 Pseudomonas aeruginosa exotoxin A enhances automaticity and potentiates hypoxic depression of isolated rat hearts; Kwiatkowska-Patzer B et al.; The potent virulence factor exotoxin A, produced by Pseudomonas aeruginosa, has been reported to suppress the synthesis of the alpha-subunit of cardiac Gi protein and may have general effects upon synthesis of other myocardial proteins . To determine whether such exotoxin A actions influence specific functional properties of the intact heart, characteristics of isolated perfused hearts obtained from rats receiving injections of exotoxin A 48 hr before sacrifice were compared with those of rats receiving no exotoxin A . Exotoxin A treatment increased the spontaneous beating rates and potentiated the suppressive effects of hypoxia upon heart rate, left ventricular systolic pressure, and rates of ventricular contraction and relaxation . On the other hand, exotoxin A treatment did not influence the magnitude or rate of pressure development under control conditions, the positive chronotropic and inotropic responses to isoproterenol, or the negative chronotropic responses to adenosine . Since a specific exotoxin A-induced suppression of myocardial alpha-subunit of the Gi protein should confer hypersensitivity to isoproterenol and reduced sensitivity to adenosine, the absence of alterations in responses to these interventions suggests that exotoxin A's effect was not confined to specific suppression of this protein . However, net effects of exotoxin A exposure included a pronounced increase in excitability of the hearts and enhanced vulnerability to hypoxic insults. Infect Immun, 1993 Mar, 61(3), 1023 - 32 Laboratory and clinical evaluation of conjugate vaccines composed of Staphylococcus aureus type 5 and type 8 capsular polysaccharides bound to Pseudomonas aeruginosa recombinant exoprotein A; Fattom A et al.; The synthesis, standardization, and immunogenicity in young outbred mice and clinical evaluation in adult volunteers of investigational vaccines designed to induce serum antibodies to the type 5 and type 8 capsular polysaccharides (CPs) of Staphylococcus aureus are described . Conjugates composed of the type 5 CP and a sonicated preparation of a high-molecular-weight type 8 CP bound to a nontoxic recombinant protein derived from Pseudomonas aeruginosa exotoxin A (rEPA) were synthesized . The conjugates were nontoxic and elicited serum CP antibodies after two subcutaneous injections into young outbred mice; a third injection elicited a booster response . The lower-molecular-weight type 8 CP was not immunogenic in the mice, and the high-molecular-weight type 8 CP elicited low levels of antibodies without a booster effect . In the volunteers, neither the conjugates nor the type 8 CP alone caused significant local reactions or fever . The conjugates elicited type-specific antibodies of both the immunoglobulin M (IgM) and IgG classes after the first injection; a second injection 6 weeks later did not stimulate a booster effect . The high-molecular-weight type 8 CP alone, injected once only, elicited levels of IgG and IgM type-specific antibodies similar to those of the conjugate . The vaccine-induced CP antibodies were mostly of the IgG1 and IgG2 subclasses and had opsonophagocytic activity . The conjugates elicited IgG antibodies to the native exotoxin A with neutralizing activity . In summary, the type 5 and type 8 conjugates were safe and elicited biologically active antibodies to both the CP and rEPA components. Am J Otol, 1993 Mar, 14(2), 170 - 1 In vitro activity of ototopical drops against middle ear pathogens; Ikeda K et al.; Five types of ear drops were each assessed for effectiveness on the basis of the in vitro antibacterial activity . Staphylococcus aureus, methicillin-resistant S . aureus (MRSA), and Pseudomonas aeruginosa isolated from purulent otitis media were evaluated by comparative analysis . Otic drops containing new fluorinated quinolones, Ofloxacin and NY-198, showed high in vitro activity against all the bacteria . Cortisporin expressed moderate activity against P . aeruginosa and relatively weak activity against S . aureus and MRSA . Bestron and Fosmicin possessed low activity against three clinical isolates . Otic drops containing the new quinolones may be effective for treating purulent otitis media infected by MRSA and P . aeruginosa. J Gen Microbiol, 1993 Mar, 139 ( Pt 3), 441 - 5 Oxygen-dependent alginate synthesis and enzymes in Pseudomonas aeruginosa; Leitao JH et al.; Alginate production by the highly alginate-producing Pseudomonas aeruginosa 8821M was maximal at a dissolved oxygen tension (DOT) of 5% of air saturation . Lower DOT limited growth and alginate synthesis . At higher DOT values up to 70% of air saturation, the specific alginate production rate decreased . Nevertheless, the molecular mass of the alginate increased at higher aerations, as indicated by the viscosity of solutions of the isolated biopolymer . The specific activity of the four enzymes leading to GDP-mannuronic acid formation, phosphomannose isomerase (PMI), phosphomannomutase (PMM), GDP-mannose pyrophosphorylase (GMP) and GDP-mannose dehydrogenase (GMD), increased with DOT of up to 25% . At higher DOT, however, only GMP and GMD maintained their maximum values . Changes observed at high oxygen concentrations in the relative activities of PMI and GMP, which are activities of the same bifunctional protein, were attributed to the much higher sensitivity of PMI activity to irreversible oxidative inactivation . The less pronounced decrease of PMM activity at high DOT correlated with an intermediate sensitivity to oxidative inactivation, but could also be related to sequential induction of PMM by the product of the PMI reaction . Thus, oxygen-dependence of alginate synthesis was at least partially the effect of DOT on GDP-mannuronic acid formation . Optimal aerations for maximal alginate production (DOT = 5-10%) were below the aeration level (70%) that led to the highest viscosity . These results suggest that, like GMD, polymerization activity is not very sensitive to oxidative inactivation and they are consistent with the hypothesis that polymerization is dependent on GMD activity, or is regulated in a similar way. Antimicrob Agents Chemother, 1993 Mar, 37(3), 483 - 90 Pharmacodynamics of a fluoroquinolone antimicrobial agent in a neutropenic rat model of Pseudomonas sepsis; Drusano GL et al.; We examined the impact of dose fractionation and altered MICs on survivorship in a neutropenic rat model of Pseudomonas aeruginosa sepsis employing the new fluoroquinolone antibiotic lomefloxacin . Once-daily administration of a drug dose which produced a high peak concentration/MIC (peak/MIC) ratio (ca . 20/1) produced significantly better survivorship compared with regimens employing the same daily dose but on a more fractionated schedule . The use of a smaller dose, producing lower (< 10/1) peak/MIC ratios, did not show this effect, as once-daily and twice-daily regimens produced equivalent results (the area under the concentration-time curve/MIC ratio was linked to survivorship) . Challenge with resistant mutants selected for altered MICs of fluoroquinolones (two and four times the MIC for the parent strain, respectively) resulted in markedly diminished survivorship . Challenge with the parent strain and use of a drug dose which produced a peak/MIC ratio identical to that for animals challenged with the mutant for which the MIC was four times that for the parent strain and treated with the larger drug dose produced survivorship curves which were not different . For this animal model, peak/MIC ratio was linked to survivorship, particularly when high ratios (10/1 to 20/1) were obtained . At lower doses, producing peak/MIC ratios < 10/1, the area under the concentration-time curve relative to the MIC appeared to be most closely linked to outcome . The time that levels in plasma exceeded the MIC did not influence survivorship . The hypothesis most likely to explain these findings is that higher peak/MIC ratios can suppress the parent strain and mutant organisms (gyrA and transport mutants) for which the MIC is higher but limited (no more than eight times that for the parent strain). J Leukoc Biol, 1993 Mar, 53(3), 273 - 8 Migratory responses of ovine neutrophils to inflammatory mediators in vitro and in vivo; Mulder K et al.; The migration of 111In-labeled ovine neutrophils towards a range of inflammatory mediators was examined in vitro using a 48-well chemotaxis chamber . Typical curves were obtained for the chemotactic response to zymosan-activated plasma (ZAP, a source of C5a) and interleukin-8 (IL-8) . In contrast, leukotriene B4 (LTB4), platelet-activating factor (PAF), interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF-alpha), N-formyl-methionine-leucyl-phenylalanine (fMLP), and endotoxins from Escherichia coli and Pseudomonas aeruginosa failed to induce neutrophil migration in vitro . Of these mediators LTB4, ZAP, IL-1 alpha, TNF-alpha, IFN-gamma, and IL-8 have been reported to induce neutrophil accumulation in skin of sheep, and in the current study E . coli endotoxin was a potent inducer of 111In-labeled neutrophil accumulation and plasma leakage in skin . In contrast, PAF induced intense plasma leakage but failed to induce accumulation of 111In-labeled neutrophils in skin . Histologic examination of skin sites receiving PAF confirmed the failure of PAF to stimulate neutrophil extravasation . FMLP lacked inflammatory activity in skin . Coinjection of actinomycin D did not abrogate recruitment of neutrophils to skin sites receiving LTB4; thus neither induction of endothelial adhesion molecules nor synthesis of IL-8 was necessary for LTB4 to exhibit inflammatory activity in vivo. Eur J Biochem, 1993 Mar 1, 212(2), 289 - 96 Reduction potentials and their pH dependence in site-directed-mutant forms of azurin from Pseudomonas aeruginosa; Pascher T et al.; A spectroelectrochemical method has been used to determine the reduction potential of the copper site in wild-type and 22 mutant forms of azurin from Pseudomonas aeruginosa at 25 degrees C and in the range pH 4-8; the effect of buffers and ionic strength on the potentials has also been studied . Amino-acid residues changed include Met121, which provides an S atom at a distance of about 0.3 nm from the metal, some amino acids in the hydrophobic patch, other residues believed to be important in electron transfer with physiological partners and some internal amino acids . The observed potentials span a range of about 300 mV . In all cases the potentials increase with decreasing pH, but the pKa values describing the pH dependence are essentially unchanged except in three mutants, where they change by pH 0.6-1.1 (up in one and down in two) . The largest potential changes were found in some Met121 mutants, at which position large hydrophobic residues raise the potential, whereas negatively charged residues lower it; a decreased potential is also found in the Met121-->End mutant, which probably has H2O coordinated to the metal . Gly45 has its carbonyl group coordinated to copper, but the potential of Gly45-->Ala is close to that of the wild type . Some substitutions in the hydrophobic patch cause an increase in the potential, whereas substitutions involving His35 and Glu91 do not result in significant changes . No single mechanism for tuning the potential of the copper site can be discerned, but in many cases there are probably indirect effects of the protein conformation causing changes in metal-ligand interactions. Bull Acad Natl Med, 1993 Mar, 177(3), 395 - 402; discussion 402-3 {Specificity of bronchopulmonary infection in cystic fibrosis}; Roussel P; Chronic lung colonization in CF is specific and due mainly to Pseudomonas aeruginosa . Since no phagocytic or immunological abnormalities seem to be responsible for this specificity, it is possible that post-translational alterations of respiratory mucins biosynthesis occur and modify the affinity of mucins for Pseudomonas aeruginosa. Pathol Biol (Paris), 1993 Mar, 41(3), 249 - 54 {Serology of anti-Pseudomonas aeruginosa and mucoviscidosis: diagnostic aid in the differentiation between colonization and infection}; Recule C et al.; Serologic test for Pseudomonas aeruginosa have been found useful for differentiating colonization from infection, especially in chronic disease . A Western blot method was compared with the ELISA used routinely . The Western blot detected serum IgGs against P . aeruginosa outer membrane proteins, whereas the ELISA reacted with IgGs against soluble P . aeruginosa antigens . Among the 103 sera from 58 cystic fibrosis patients studied, all those with ELISA reactivity were positive by Western blot . The antibody response was detected earlier by Western blot than by ELISA, suggesting that the former technique may be useful for the early diagnosis of infection. Pediatr Pulmonol, 1993 Mar, 15(3), 135 - 9 Elevated exoenzyme expression by Pseudomonas aeruginosa is correlated with exacerbations of lung disease in cystic fibrosis; Grimwood K et al.; Two studies were conducted to determine whether Pseudomonas aeruginosa exoenzyme expression was increased during pulmonary exacerbations of cystic fibrosis (CF) and if it was reduced by antibiotic therapy . The first study was retrospective comparing in vitro exoenzyme levels expressed by P . aeruginosa sputum isolates from seriously ill, hospitalized patients with CF to those from P . aeruginosa strains isolated from CF clinic patients who were in relatively better health . Exoenzyme values were significantly greater in P . aeruginosa strains isolated from ill, hospitalized patients than in clinic patients (P = 0.0001) . In the prospective study, in vitro exoenzyme levels were measured from sputum P . aeruginosa isolates of 9 hospitalized patients with CF . Exoenzyme values were greatest in nonmucoid strains on admission (P < 0.0025), and P . aeruginosa exoenzyme expression decreased significantly during hospitalization (P < 0.0025) . Deterioration in CF lung disease was accompanied by increased P . aeruginosa exoenzyme production, especially by nonmucoid strains . Antibiotic treatment during hospitalization resulted in mean improvement of % predicted forced expiratory volume in 1 sec (FEV1) from 39 to 53% (P = 0.002) . Thus, antibiotics may improve pulmonary function in patients with CF by decreasing P . aeruginosa exoenzyme expression. Microb Releases, 1993 Mar, 1(4), 237 - 41 In vivo transfer of pR68.45 from Pseudomonas aeruginosa into indigenous soil bacteria; Glew JG et al.; The release of genetically engineered organisms (GEMs) into the environment could result in novel gene sequences becoming transferred to, and established in, the indigenous soil biota . The potential for recombination in nonsterile soil is difficult to determine due to problems isolating transconjugants of indigenous microbes, while concurrently suppressing introduced donors . We have developed a system that allows us to detect the transfer of the plasmid R68.45 from Pseudomonas aeruginosa strain PA025 into the indigenous soil bacterial population . Transconjugants were selected by plating on minimal media containing antibiotics and were verified by DNA-DNA hybridization . The observed maximum transfer frequency was approximately 10(-6) . Fatty acid analysis of transconjugants showed that intergeneric transfer was occurring between the introduced organism and genetically dissimilar species. Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1993 Mar, 9(2), 118 - 20, 159 {Comparison of topical therapeutic effect between silver norfloxacin (Ag-NFL) and silver sulfadiazine (Ag-SD) in treatment of pyocyaneous sepsis in burn rats}; Huo ZL; The purpose of the study was to carry out a further investigation of the efficacy of topical antimicrobial treatment of Ag-NFL in comparison with that of the most commonly used topical agent Ag-SD . An experimental model of rats with 20% TBSA full thickness burns seeded with 109 CFU of Pseudomonas aeruginosa ATCC-27853 was used . At 24, 48 and 72h after the seeding bacteriologic examination showed that the subeschar bacterial counts exceeded 10(6) CFU per gram of tissue . Subeschar bacterial counts were zero in the group in which Ag-NFL was used, while those in the group using Ag-SD were almost the same as the control . The amount of silver accumulated in the eschar of Ag-NFL, treated rats was significantly higher than that of Ag-SD treated rats . In conclusion, Ag-NFL was proved valuable in the treatment of burn wound infection caused by invading organisms, particularly by the Ag-SD resistant strain of Pseudomonas. Agents Actions, 1993 Mar, 38(3-4), 196 - 201 Piroxicam-copper complexes: inhibition of polymorphonuclear leukocyte migration to Pseudomonas aeruginosa chemotactins in vivo and superoxide dismutase-like activity in vitro; Sordelli DO et al.; Piroxicam-copper (Cu2+) complexes, formed spontaneously by mixing solutions of piroxicam and CuSO4 (1:1 Cu2+:piroxicam), inhibited the superoxide anion-catalyzed reduction of ferricytochrome C in a dose-related fashion . Addition of ethylenediaminetetraacetate to the mixture decreased in a dose-related manner the superoxide dismutase (SOD)-like activity of piroxicam-Cu2+ . Piroxicam alone (10(-5) M, final concentration) did not display SOD-like activity but 10(-5) M Cu2+ exhibited significant activity, similar to that of piroxicam-Cu2+ . Intraperitoneal treatment of mice with either 0.64 mg/kg piroxicam or its Cu2+ complexes (0.64 mg/kg piroxicam + 0.12 mg/kg Cu2+) was equally effective in diminishing both the migration of polymorphonuclear leukocytes (PMNL) to the airways and the content of myeloperoxidase activity in the lungs, induced by aerosol challenge with Pseudomonas aeruginosa peptide chemotactins . Therefore, piroxicam-Cu2+ complexes may provide both the anti-inflammatory activity of piroxicam plus the SOD-like activity of Cu2+. J Pharm Pharmacol, 1993 Mar, 45(3), 171 - 5 Investigation of synergism between combinations of ciprofloxacin, polymyxin, sulphadiazine and p-aminobenzoic acid; Richards RM et al.; Subinhibitory concentrations of combinations of any two of ciprofloxacin, colistin (or polymyxin B), sodium sulphadiazine and p-aminobenzoic acid were shown by checkerboard minimum inhibitory concentration determinations to have synergistic inhibitory activity against Pseudomonas aeruginosa and to have either synergistic or additive activity against Staphylococcus aureus . In addition, sulphadiazine plus either ciprofloxacin or polymyxin showed markedly enhanced killing activity against both P . aeruginosa and S . aureus . p-Aminobenzoic acid plus either ciprofloxacin or polymyxin also demonstrated enhanced killing activity against P . aeruginosa but these combinations were less effective in enhancing activity against S . aureus . Ciprofloxacin in combination with polymyxin had a marked synergistic effect against P . aeruginosa but only a slight synergistic effect against S . aureus . These findings indicate a potential usefulness for the synergistic combinations against P . aeruginosa and S . aureus in the clinical situation; that is, they indicate an extended role for sulphonamides and support a potential role for p-aminobenzoic acid as enhancers of the activity of primary antibacterial agents such as ciprofloxacin and polymyxin . We suggest that for a second antibacterial to enhance the activity of ciprofloxacin, it may be necessary for the second antibacterial to increase cell permeability so increasing bacterial uptake of ciprofloxacin. Mol Microbiol, 1993 Mar, 7(5), 669 - 82 PilS and PilR, a two-component transcriptional regulatory system controlling expression of type 4 fimbriae in Pseudomonas aeruginosa; Hobbs M et al.; Transposon mutagenesis was used to identify genes necessary for the expression of Pseudomonas aeruginosa type 4 fimbriae . In a library of 12,700 mutants, 147 were observed to have lost the spreading colony morphology associated with the presence of functional fimbriae . Of these, 28 had also acquired resistance to the fimbrial-specific bacteriophage PO4 . The mutations conferring this phage resistance were found to have occurred at at least six different loci, including the three that had been previously shown to be required for fimbrial biosynthesis or function: the structural subunit (pilA) and adjacent genes (pilB,C,D), the twitching motility gene (pilT), and the sigma 54 RNA polymerase initiation factor gene (rpoN) . One novel group of phage-resistant mutants was identified in which the transposon had inserted near sequences that cross-hybridized to an oligonucleotide probe designed against conserved domains in regulators of RpoN-dependent promoters . These mutants had no detectable transcription of pilA and did not produce fimbriae . A probe derived from inverse polymerase chain reaction was used to isolate the corresponding wild-type sequences from a P . aeruginosa PAO cosmid reference library, and two adjacent genes affected by transposon insertions, pilS and pilR, were located and sequenced . These genes were shown to be capable of complementing the corresponding mutants, both at the level of restoring the phenotypes associated with functional fimbriae and by the restoration of pilA transcription . The pilSR operon was physically mapped to Spel fragment 5 (corresponding to about 72-75/0 min on the genetic map), and shown to be located approximately 25 kb from pilA-D . PilS and PilR clearly belong to the family of two-component transcriptional regulatory systems which have been described in many bacterial species . PilS is predicted to be a sensor protein which when stimulated by the appropriate environmental signals activates PilR through kinase activity . PilR then activates transcription of pilA, probably by interacting with RNA polymerase containing RpoN . The identification of pilS and pilR makes possible a more thorough examination of the signal transduction systems controlling expression of virulence factors in P . aeruginosa. Arch Biochem Biophys, 1993 Feb 15, 301(1), 85 - 90 Isoelectrophoretic characterization of Pseudomonas cytochrome oxidase/nitrite reductase and its heme d1-containing domain; Hull HH et al.; The cytochrome oxidase/nitrite reductase of Pseudomonas aeruginosa has been purified to homogeneity as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis . When this "homogeneous" protein is subjected to electrophoretic titration curve analysis in ampholines or to isoelectric focusing in immobilized pH gradient gels it is resolved into several bands, each of which possesses the olive-green color of the holoenzyme . Although the patterns of resolution replicate for a given enzyme preparation differences occur among different preparations . Furthermore, storage for several months at -20 degrees C leads to an increase in the number of isoelectrophoretic forms . All preparations, however, have two primary bands, one with a pI of 6.97 and the other of 7.02 . Both these bands possess significant cytochrome oxidase activity after elution from the gels . When each of the primary bands is eluted and again subjected to isoelectric focusing under the same conditions as before, each band interconverts into two bands with pIs of 6.97 and 7.02 . The addition of the ligand cyanide to the holoenzyme produces a shift in the pI of the two bands to pIs 7.04 and 7.12 while the addition of nitrite shifts some of the band at pI 6.97 into that at pI 7.02 . The heme d1-containing dipeptide of the enzyme, produced by treatment with subtilisin, also exhibits considerable heterogeneity upon electrophoretic titration curve analysis and by isoelectric focusing in immobiline gels . Possible explanations for the observed isoelectrophoretic behavior in terms of protein conformation and heme chemistry are discussed. Biochem J, 1993 Feb 15, 290 ( Pt 1), 123 - 7 Quaternary structure of quinoprotein ethanol dehydrogenase from Pseudomonas aeruginosa and its reoxidation with a novel cytochrome c from this organism; Schrover JM et al.; Quinoprotein (2,7,9-tricarboxy-1H-pyrrolo-{2,3-f}quinoline-4,5-dione quinone form (PQQ)-containing) ethanol dehydrogenase (EDH) from Pseudomonas aeruginosa ATCC 17933 was purified to homogeneity . EDH has an alpha 2 beta 2 configuration and subunits comparable in size to those of methanol dehydrogenase (MDH) . Compared with other PQQ-containing dehydrogenases, Ca2+ is rather loosely bound and it seems necessary for PQQ binding and stability of EDH . Two soluble cytochromes c were detected in extracts from ethanol-grown cells and both were purified . One of these has an alpha-band at 551 nm for its reduced form, the oxidized form being an excellent electron acceptor for the semiquinone form of EDH . Since this cytochrome is quite different from the already known cytochrome c551 (operating in nitrate respiration) of this organism, it is indicated here as cytochrome cEDH . Comparison of the N-terminal amino acid sequence of cytochrome cEDH with the complete sequence of cytochrome cL (the electron acceptor of MDH), cytochrome cH (the electron acceptor of cytochrome cL) and cytochrome c551 revealed some similarity only to internal stretches of amino acids of the last two . The other soluble cytochrome appeared to be the already-known cytochrome c556 . Since it was not an electron acceptor for cytochrome cEDH (neither for EDH), cytochrome cH is lacking in the quinoprotein-EDH-ethanol oxidation system of P . aeruginosa . It seems, therefore, that the respiratory chains for MDH and EDH are different. N Z Med J, 1993 Feb 10, 106(949), 28 - 30 Clinical features of individuals with cystic fibrosis in New Zealand; Wesley A et al.; AIMS . To determine the status of cystic fibrosis patients, their mode of diagnosis and source of medical care in New Zealand . METHODS . A database was established in 1988 to record clinical information on individuals with cystic fibrosis in New Zealand . Three hundred and two cystic fibrosis patients were identified and clinical information on 248 obtained . RESULTS . Thirty five per cent of patients at diagnosis had gastrointestinal and pulmonary and 33% had gastrointestinal symptoms alone . Ninety three infants were diagnosed after a positive screening test and confirmatory sweat test . The mean age at diagnosis overall was 1.8 years, while 61% of children were diagnosed before one year of age . 74.2% of patients were said to be pancreatic insufficient, 4% pancreatic sufficient and in 22% the results were unavailable or unknown . Medical care was provided by 28 sources comprising paediatricians, physicians or combined clinics . One cystic fibrosis clinic cared for more than 40 patients . Sixty-one per cent of cystic fibrosis subjects were colonised with Staphylococcus aureus at some time, and 44% were reported to be colonised with Pseudomonas aeruginosa . CONCLUSIONS . Common clinical features of cystic fibrosis have been characterised for New Zealand patients . It is unknown to what extent the clinical features of the disease and source of medical care in New Zealand are responsible for previously reported survival for the condition but it is planned to examine serial measurements of growth, nutrition, pulmonary function and survival and it is hoped that these measurements will be the subject of a further report. J Chemother, 1993 Feb, 5(1), 14 - 6 Transferable resistance to imipenem in hospital isolates of Pseudomonas aeruginosa; Hupkova M et al.; We monitored systematically, for more than five years, the eventual transferability of resistance to imipenem in strains of Pseudomonas aeruginosa isolated from patients in Frankfurt University Clinics . Quite recently, four strains have been found which transfer resistance to imipenem to recipient strains of P . aeruginosa . Although in three strains imipenem was the only antibiotic where resistance was transferred directly, the indirect selection analysis showed that, in each instance, determinants of resistance to carbenicillin and kanamycin were co-transferred . The situation in the fourth strain was more complicated . It was resistant to at least ten antipseudomonad antibiotics, and transferred directly not only determinants of resistance to imipenem, but also to carbenicillin and kanamycin, as did the other strains, plus determinants of resistance to ceftazidime and cefotaxime . The origin and mode of spread of resistance determinants in studied strains is briefly discussed. FEMS Microbiol Lett, 1993 Feb 1, 106(3), 281 - 6 Isolation and characterization of two immunochemically distinct alkaline phosphatases from Pseudomonas aeruginosa; Tan AS et al.; We have isolated two alkaline phosphatases (H-AP and L-AP, for high and low molecular mass, respectively) from Pseudomonas aeruginosa PA01 . These two enzymes were found to differ in mobility on sodium dodecyl sulphate polyacrylamide gels (H-AP, M(r) = 51,000 and L-AP, M(r) = 39,500), amino-terminal amino acid sequence and did not cross-react . Both enzymes were active as phosphomonoesterases while only L-AP demonstrated any phosphodiesterase activity . Both enzymes were purified from P . aeruginosa grown in phosphate limiting conditions using the same protocol and were identified in both periplasmic and extracellular locations . A low level of H-AP was produced constitutively whereas L-AP was produced only after induction by reduced phosphate concentration in the growth medium . An L-AP-like enzyme has been previously described, however, this is the first report of a second P . aeruginosa alkaline phosphatase. Antimicrob Agents Chemother, 1993 Feb, 37(2), 308 - 13 Efficacy of ceftazidime and aztreonam alone or in combination with amikacin in experimental left-sided Pseudomonas aeruginosa endocarditis; Pefanis A et al.; The in vivo efficacies of ceftazidime, aztreonam, and the combinations of ceftazidime with amikacin and aztreonam with amikacin were studied in the rabbit left-sided endocarditis model by using two strains of Pseudomonas aeruginosa, one multisusceptible and one multiresistant, in a total of 156 animals . Antibiotics were given intramuscularly for 10 days, as follows: amikacin, 7 mg/kg of body weight every 8 h, and ceftazidime and aztreonam, 50 mg/kg every 8 h . All regimens except amikacin alone significantly reduced the number of CFU per gram of vegetation (P < or = 0.008), but only for the multisusceptible strain for which sterile vegetations were obtained in 20, 25, 21, 75, and 53% of the groups treated with amikacin, ceftazidime, aztreonam, and the combination groups ceftazidime-amikacin and aztreonam-amikacin, respectively (ceftazidime plus amikacin versus controls, P = 0.001) . Regarding the decrease in the numbers of colonies in vegetations, (i) all regimens significantly reduced the number of CFU per gram of vegetation (P < 0.001), (ii) results with ceftazidime-amikacin compared with those with monotherapy were significantly different (P < or = 0.007), and (iii) results with aztreonam-amikacin, although better than those with monotherapy, were marginally not statistically significant . At 1 h postdose, mean amikacin, aztreonam, and ceftazidime levels in serum were 35 +/- 19.4, 89.6 +/- 8.16, and 92.61 +/- 11.52 micrograms/ml, respectively . It was concluded that the combination of ceftazidime, and possibly aztreonam, with amikacin given at high doses and short intervals could have a place in the therapy of patients with left-sided endocarditis caused by P . aeruginosa. Antimicrob Agents Chemother, 1993 Feb, 37(2), 276 - 80 Effects of interleukin-8 on nonspecific resistance to infection in neutropenic and normal mice; Vogels MT et al.; The effect of treatment with interleukin-8 (IL-8), a neutrophil-activating cytokine, was investigated in normal and neutropenic mice infected with a lethal dose of Pseudomonas aeruginosa, Klebsiella pneumoniae, or Plasmodium berghei . Intraperitoneal (i.p.) IL-8 treatment was associated with accelerated death when IL-8 was administered shortly before i.p . infection with P . aeruginosa or shortly after i.p . infection with P . aeruginosa and K . pneumoniae . Histopathological analyses demonstrated a tendency to more severe organ lesions in IL-8-treated mice . Only nonneutropenic mice that received IL-8 shortly before the infectious challenge and at the site of infection were protected by IL-8 . Whether IL-8 is protective of or detrimental to the survival of infection appeared to depend on the presence of bacteria at the injection site and on the presence of neutropenia . IL-8 may be an important participant in the cascade of interacting cytokines that is induced by the lethal infectious challenge. Hautarzt, 1993 Feb, 44(2), 103 - 5 {Pseudomonas aeruginosa folliculitis after epilation}; Trueb RM et al.; We report on a rare case of Pseudomonas aeruginosa folliculitis following depilation of the legs in a 33-year-old woman . Recently attention has been drawn to Pseudomonas-folliculitis acquired from whirlpools . The possibility of P . aeruginosa folliculitis occurring after skin depilation is less well known . The source of infection may be contaminated cosmetics or the hospital environment . The conditions favouring Pseudomonas invasion of the skin, and the clinical picture, course and of treatment P . aeruginosa folliculitis are discussed. J Trop Pediatr, 1993 Feb, 39(1), 32 - 6 Epidemiology of Pseudomonas aeruginosa infections in a neonatal intensive care unit; Gupta AK et al.; During the 19-month study period, 48 (2 per cent) of the 2177 neonates admitted to the neonatal intensive care unit (NICU) yielded Pseudomonas aeruginosa growths in blood cultures . All these neonates had clinical and haematological evidences of sepsis . Prominent clinical features included sclerema, violaceus necrotic patches, necrotizing enterocolitis (NEC), conjugated hyperbilirubinaemia, and DIC . Over all mortality was 23 per cent, distinctly higher in premature neonates with RDS . The mean gestational age and birth weights (+/- SD) of these neonates were 36.42 (+/- 2.73) weeks and 2173.34 (+/- 567.33) g, respectively . Approximately half of the total cases had low birth weight . Other adverse perinatal events before the development of sepsis included birth asphyxia (60 per cent), neonatal resuscitation (67 per cent), meconium aspiration syndrome (29 per cent), hyaline membrane disease (8 per cent), prolonged hospitalization (44 per cent), closed incubator care (17 per cent), prolonged intravenous fluids (42 per cent), repeated blood sampling (63 per cent), and umbilical catheterization (4 per cent) . Analysis of the trend of Pseudomonas sepsis in our NICU revealed six definite outbreaks (more than two cases) interspersed with occasional (one or two) cases . Six study months, however, remained free of Pseudomonas sepsis . Index case was demonstrable on seven occasions . Bacteriological surveillance of the NICU after onset of initial case/cases revealed statistically significant colonization of resuscitation equipment, baby placement sites, and various cleansing solutions by the same bacterial species (P < 0.05) . It is possible that Pseudomonas was introduced to our NICU from transfer admissions from other hospitals since on four occasions index case was the one transferred from outside.(ABSTRACT TRUNCATED AT 250 WORDS) J La State Med Soc, 1993 Feb, 145(2), 43 - 5 Necrotizing external otitis; Blake GB et al.; Necrotizing external otitis is a severe osteomyelitis of the temporal bone principally affecting elderly diabetics . It is caused by the gram negative bacillus, Pseudomonas aeruginosa . Clinical findings and diagnosis are reviewed . Long term therapy with intravenous antibiotics is recommended for cure, although newer antimicrobial agents give promise of being successful when administered orally. Ophthalmology, 1993 Feb, 100(2), 192 - 6 Microbial keratitis in childhood; Cruz OA et al.; BACKGROUND: Microbial keratitis occurs infrequently in childhood . The leading ocular predisposing factors are trauma and preexisting corneal disease . Many of the age-related risk factors in adults play a minor role in children . METHODS: The authors retrospectively studied 51 eyes with ulcerative keratitis in 50 children younger than 16 years of age . This includes all patients treated at Bascom Palmer Eye Institute during an 11 1/2-year period from January 1, 1980, to June 30, 1991 . The criterion for inclusion in the study was a discharge diagnosis of microbial (nonviral) keratitis . RESULTS: The principal risk factors identified in this study were trauma (44%), prior corneal surgery (24%), systemic illness (14%), and contact lens wear (12%) . Systemic illness or an immunocompromised state existed in 7 (47%) of the 15 children younger than 3 years of age . There was a large male preponderance (68%) . Forty-four (86.3%) of the 51 eyes were culture-positive; six (11.7%) were polymicrobial . Five of seven culture-negative patients had received prior topical antibiotic therapy . Pseudomonas aeruginosa (34%), Staphylococcus aureus (20%), and fungi (18%) were the most common organisms isolated . Seven (14%) eyes required surgery . CONCLUSION: This study presents important differentiating factors between adult and childhood nonviral microbial keratitis . Identification of principal risk factors in children may aid in early recognition and treatment of microbial keratitis. J Biomed Mater Res, 1993 Feb, 27(2), 269 - 75 111Indium labeling of microorganisms to facilitate the investigation of bacterial adhesion; Ardehali R et al.; The ability of bacteria to adhere to polymeric interfaces has attracted considerable attention in recent years . Metabolic labeling of microorganisms with 35S-methionine or other beta-emitters is commonly utilized for quantification of bacterial adhesion to biopolymers . Since the use of these isotopes is cumbersome, the possibility of labeling the microorganisms with 111Indium, a strong gamma-emitter, was explored . This report demonstrates that bacteria can be easily labeled with 111Indium . Staphylococcus aureus, Staphylococcus epidermiids, and Pseudomonas aeruginosa were labeled with either 111Indium-oxine or 35S-methionine; and labeling efficiency, retention of incorporated labels, and growth kinetics of labeled bacteria were compared under identical experimental conditions . Bacteria labeled with 111In-oxine incorporated approximately 90% of radioactivity within 10 min, whereas 35S-methionine incorporation required many hours of incubation . Both the incorporated isotopes were gradually released by rapidly growing bacteria into the suspension medium . Of the total incorporated labels, approximately 20% 111In and 15% 35S were released in the surrounding medium every 24 h . No release of incorporated labels occurred when cells were fixed with 2.5% buffered glutaraldehyde . Growth kinetics and scanning or transmission electron microscopic analysis showed no detectable differences among control (nonlabeled), 111In-, or 35S-labeled bacteria . Labeling of bacteria with 111In-oxine does not interfere with bacterial adherence . These observations suggest that 111In incorporation provides a simple and rapid method of labeling of microorganisms . Compared to currently available techniques, the use of 111In-labeled bacteria will facilitate the quantitation of adherent bacteria to interfaces. Burns, 1993 Feb, 19(1), 52 - 5 Laboratory data from the surveillance of a burns ward for the detection of hospital infection; Pandit DV et al.; Nosocomial infection is a major problem affecting many hospital personnel and patients . Surveillance of intensive care areas such as burns wards is important due to the immunocompromised status of the patients . Since infection has been found to be a major cause of death in our burns ward, bacteriological surveillance of the area was carried out over a 1-year period . This indicated the various sources of infection, which included a contaminated container of disinfectant, and transient pathogenic flora on one of the staff members involved in changing dressings . Pseudomonas aeruginosa was the most commonly isolated pathogen from infected wounds as well as from the blood of patients developing sepsis . Autogenous spread of this organism was confirmed by similar pyocin typing results of the strains isolated from wounds, blood and faeces of the patients . Necessary changes were implemented based on these findings and the infection rate was reduced remarkably . The results suggested that strict vigilance by the personnel involved in the care of burns patients reduces the incidence of invasive sepsis and shortens the hospital stay. J Clin Microbiol, 1993 Feb, 31(2), 458 - 9 Mixed-morphotype broth microdilution susceptibility testing of Pseudomonas aeruginosa from cystic fibrosis patients; Van Horn KG; Multiple morphotypes of Pseudomonas aeruginosa isolated from 50 respiratory specimens of cystic fibrosis patients were tested for correlation of broth microdilution susceptibility results of a mixed-morphotype inoculum with a predicted antibiogram of the individual isolates . The overall correlation was 96.0%, with only 1.6% very major or major errors. J Bacteriol, 1993 Feb, 175(4), 1153 - 64 Characterization of a locus determining the mucoid status of Pseudomonas aeruginosa: AlgU shows sequence similarities with a Bacillus sigma factor; Martin DW et al.; Overproduction of the exopolysaccharide alginate by Pseudomonas aeruginosa results in mucoid colony morphology and is an important virulence determinant expressed by this organism in cystic fibrosis . Mucoidy is transcriptionally regulated by signal transduction systems and histone-like elements . One point of convergence of regulatory elements controlling mucoidy is the algD promoter . A newly described genetic locus required for algD transcription was characterized in this study . This DNA region, cloned from a nonmucoid PAO strain, was initially isolated on the basis of its ability to suppress mucoidy when present on a plasmid . The suppressing activity was observed in several mucoid PAO derivatives, including strain PAO568, in which the mapped muc-2 mutation is responsible for its mucoid phenotype, and in close to 40% of cystic fibrosis strains tested . Protein expression studies detected two polypeptides with apparent molecular masses of 27.5 and 20 kDa encoded by the region required for the suppression activity . The gene encoding the polypeptide with an apparent molecular mass of 27.5 kDa, termed algU, was further characterized . A functional chromosomal copy of algU was found to be necessary for the expression of mucoidy . Insertional inactivation of algU on the chromosome of the mucoid strain PAO568 abrogated alginate production and algD transcription . DNA sequence analysis revealed sequence similarity of the predicted algU gene product with sigma H (Spo0H), a sigma factor involved in the control of sporulation and competence in Bacillus spp . Physical mapping revealed that algU resided on the same SpeI fragment (F) as did the pruAB locus, known to be tightly linked with genetic determinants (muc) which can confer mucoidy in genetic crosses . When the chromosomal algU copy was tagged with a Tcr cassette (algU::Tcr), a tight genetic linkage of algU with pruAB was demonstrated by F116L-mediated generalized transduction . Moreover, algU::Tcr derivatives of PAO568 (originally carrying the muc-2 marker) lost the ability to transfer mucoidy in genetic crosses . These results suggest that algU, a regulator of algD transcription showing sequence similarity to an alternative sigma factor, and the genes immediately downstream of algU may be associated with a locus participating in the differentiation into the mucoid phenotype. J Bacteriol, 1993 Feb, 175(4), 1069 - 74 Organization and transcription of the principal sigma gene (rpoDA) of Pseudomonas aeruginosa PAO1: involvement of a sigma 32-like RNA polymerase in rpoDA gene expression; Fujita M et al.; S1 nuclease mapping and Northern (RNA) hybridization revealed that the rpoDA gene encoding the principal sigma subunit of Pseudomonas aeruginosa PAO1 is transcribed as a monocistronic mRNA of 2 kb and that the transcription from the rpoDA promoter (PC) starts 32 bases upstream from the first nucleotide of the initiation codon during the steady-state growth condition at a low temperature (30 degrees C) . The transcript terminates 31 bases downstream from the last nucleotide of the termination codon . When the growth temperature was shifted to 42 degrees C, the synthesis of rpoDA mRNA from a heat shock promoter was transiently induced, although transcription was still occurring from PC during the heat shock period . The transcription initiation site of the heat shock promoter (PHS) is located about 220 bases upstream of the initiation codon of rpoDA . In addition, both promoters were utilized in vitro by RNA polymerase partially purified from heat-shocked cells of P . aeruginosa PAO1 . When the rpoDA was introduced into Escherichia coli, the transcription patterns of rpoDA at 30 and 42 degrees C were similar to those observed for P . aeruginosa . These results suggested that the transcription of rpoDA in P . aeruginosa is regulated by the principal RNA polymerase and the heat shock RNA polymerase in response to the environmental temperature. J Med Microbiol, 1993 Feb, 38(2), 79 - 86 Vaccine efficacies of elastase, exotoxin A, and outer-membrane protein F in preventing chronic pulmonary infection by Pseudomonas aeruginosa in a rat model; Gilleland HE et al.; The protective efficacies of eight vaccine preparations consisting of Pseudomonas aeruginosa outer-membrane protein F, elastase and exotoxin A toxoid, administered either individually or in various combinations, were determined in a rat model of chronic pulmonary infection . Rats were immunised intramuscularly at 2-week intervals (days 0, 14 and 28) . On day 42, blood was collected and antisera were obtained from each vaccine group for use in an enzyme-linked immunosorbent assay which determined the titre of IgG antibodies elicited by each vaccine . Also on day 42, rats were challenged by intratracheal inoculation of a clinical isolate of P . aeruginosa encased within agar beads . On day 49, the animals were killed and the lungs were examined macroscopically for the presence of lesions and fixed for histological examination . When compared with control rats immunised with bovine serum albumin, rats immunised with protein F alone as a vaccine received significant protection against the development of severe pulmonary lesions . Elastase used alone as a vaccine provided some protection against severe lung lesions and reduced the incidence of microscopic peribronchial inflammation . However, the combination of protein F plus elastase as a vaccine did not afford protection from severe lesions, and there was an increased incidence of necrotising granulomas in the lungs from this vaccine group . Protection against lung lesions from the three-component vaccine consisting of protein F, elastase and exotoxin A toxoid was similar to that provided by the protein F vaccine . Neither macroscopic nor histological evidence showed any enhancement of protective efficacy for the three-component vaccine over that of the protein F vaccine.(ABSTRACT TRUNCATED AT 250 WORDS) J Bacteriol, 1993 Feb, 175(3), 912 - 5 The inherent DNase of pyocin AP41 causes breakdown of chromosomal DNA; Sano Y; Pyocin AP41 degrades the chromosomal DNA in sensitive strains of Pseudomonas aeruginosa but has little effect on RNA, protein, and lipid syntheses . In vitro experiments showed that the carboxyl-terminal part of the large subunit of pyocin AP41 carries an inherent DNase that is responsible for its killing action. J Bacteriol, 1993 Feb, 175(3), 898 - 901 Use of synthetic peptides and site-specific antibodies to localize a diphtheria toxin sequence associated with ADP-ribosyltransferase activity; Olson JC; Diphtheria toxin (DT) and Pseudomonas aeruginosa exotoxin A have the same molecular mechanism of toxicity; both toxins ADP-ribosylate a modified histidine residue in elongation factor 2 . To help identify amino acids involved in this reaction, sequences in DT that share homology with P . aeruginosa exotoxin A were synthesized and examined for a role in the ADP-ribosyltransferase reaction . By using this approach, residues 32 to 54 of DT were found to define an epitope associated with antibody-mediated inhibition of DT enzyme activity . This lends further support to the notion that residues in this region of DT are involved in the enzymatic reaction. Infect Immun, 1993 Feb, 61(2), 559 - 64 Suppression of lymphocyte and neutrophil functions by Pseudomonas aeruginosa mucoid exopolysaccharide (alginate): reversal by physicochemical, alginase, and specific monoclonal antibody treatments; Mai GT et al.; The mucoid exopolysaccharide (MEP or alginate) of Pseudomonas aeruginosa is thought to be a virulence factor for this organism by virtue of its ability to suppress local host defense mechanisms . We purified MEP from clinical isolates of mucoid P . aeruginosa, subjected it to degradation by ultrasonication, heat, alkali, and alginase, and reacted it with monoclonal antibodies specific for MEP epitopes . Partial reversal or complete abrogation of the inhibitory effects of alginate on human neutrophil random migration, chemotaxis, and hexose monophosphate shunt activity and lymphocyte transformation were observed following most of these treatments . Physicochemical analysis of degraded MEP revealed a positive correlation between changes in molecular size and viscosity and loss of biological properties . The biological properties of MEP were also shown to be dependent on the structural integrity of the O-acetyl groups substituted for the mannuronic acid residues . The results show that the capacity of MEP to suppress neutrophil and lymphocyte functions is dependent on its acetyl content and the physical properties of large size and viscosity and may provide part of the explanation for the propensity of mucoid P . aeruginosa to persist in the airways of patients with cystic fibrosis . These findings highlight the important role of MEP as one of the virulence factors in the pathogenesis of inflammatory damage and subsequent pulmonary destruction in cystic fibrosis. J Antimicrob Chemother, 1993 Feb, 31(2), 219 - 25 Chlorhexidine hypersensitivity of ciprofloxacin-resistant variants of Pseudomonas aeruginosa PAO; Baillie LW et al.; Examination of 67 ciprofloxacin-resistant clones of Pseudomonas aeruginosa PAO (ciprofloxacin MIC > 0.5 mg/L) yielded four isolates that were hypersensitive to chlorhexidine (MIC 5 mg/L); none was found among 179 ciprofloxacin-sensitive colonies . Revertant studies and the introduction of a wild-type Escherichia coli DNA gyrase A gene confirmed that ciprofloxacin resistance and chlorhexidine hypersensitivity were not the result of a single mutation . Mutagenicity testing of ciprofloxacin showed no evidence for the supposition that chlorhexidine hypersensitivity was the result of ciprofloxacin-induced mutation in P . aeruginosa PAO. Mol Gen Genet, 1993 Feb, 237(1-2), 161 - 70 A novel transposon-like structure carries the genes for pyocin AP41, a Pseudomonas aeruginosa bacteriocin with a DNase domain homology to E2 group colicins; Sano Y et al.; The genetic determinant for pyocin AP41, a bacteriocin produced by Pseudomonas aeruginosa, has been cloned . The determinant is located on the chromosome flanked by a pair of inverted repeats, forming a transposon-like structure (TnAP41) . TnAP41 possesses some features characteristic of the Tn3 family of transposons . Based on a comparison with the structure of the corresponding region of the chromosome of a non-producer strain, we propose that P . aeruginosa has acquired pyocinogeny by the transposition of TnAP41 into the chromosome . The determinant comprises two ORFs encoding the protein subunits responsible for the killing action (the large component) and immunity (the small component) . Amino acid sequences of the C-terminus of the large component (the deoxyribonuclease domain) and the immunity protein show remarkable homology to those of E2 group colicins, suggesting that these bacteriocins, which are produced by distantly related species, have originated from a common ancestor. Antimicrob Agents Chemother, 1993 Feb, 37(2), 164 - 70 Therapeutic effects of a human antiflagella monoclonal antibody in a neutropenic murine model of Pseudomonas aeruginosa pneumonia; Oishi K et al.; Human immunoglobulin G1 (IgG1) monoclonal antibodies (MAbs) reactive with type-specific Pseudomonas aeruginosa lipopolysaccharide (LPS) and flagella were compared for their protective activities against Fisher immunotype 2 P . aeruginosa pneumonia in neutropenic mice . The activity of the antiflagella MAb at a dose of 500 micrograms per mouse was comparable to that of the anti-LPS MAb at the same dose . In vivo protection was correlated with bacterial density in the lung tissue and blood of infected mice . In vitro data suggested that the protective activity of the antiflagella MAb was due more to inhibition of bacterial motility than to opsonophagocytosis of bacteria by alveolar macrophages . In contrast, the protective activity of the anti-LPS MAb was primarily related to alveolar macrophage-mediated opsonophagocytosis . Antiflagella MAb at a dose of 500 micrograms combined with oral sparfloxacin at a subtherapeutic dose of 62.5 micrograms produced a significant increase in survival (P < 0.05) compared with that produced by either agent alone or no treatment . The additive effects between the antiflagella MAb and sparfloxacin at sub-MICs on the inhibitory effects of bacterial motility supported the in vivo effect of the combination . These data suggest that human isotype-matched antiflagella and anti-LPS MAbs have similar protective activities against Pseudomonas pneumonia in neutropenic mice, despite discrete mechanisms of antibody-matched protection . In addition, in vivo synergy was demonstrated between antiflagella MAb and sparfloxacin in this model. Proc Natl Acad Sci U S A, 1993 Feb 1, 90(3), 965 - 9 Inhibitors of two-component signal transduction systems: inhibition of alginate gene activation in Pseudomonas aeruginosa; Roychoudhury S et al.; Pseudomonas aeruginosa strains infecting cystic fibrosis patients often produce copious amounts of the exopolysaccharide alginate . Expression of alginate genes in P . aeruginosa is regulated by several proteins including members of the two-component bacterial signal transduction systems . Two of these regulatory proteins are AlgR1, the DNA-binding response regulator that transcriptionally activates alginate gene expression, and AlgR2, the kinase that modifies AlgR1 via phosphorylation to enhance its activity . In this paper, we report the identification of compounds that inhibit alginate gene expression by inhibiting (i) the phosphorylation/dephosphorylation of AlgR2 and (ii) the DNA-binding activity of AlgR1 . Compounds with these activities may have potential as components of therapy for eliminating P . aeruginosa infection from the cystic fibrosis lung . In addition, we describe the effect of these compounds on the autophosphorylation activity of other known two-component kinases and show the ability of one compound to significantly inhibit the kinase activities of CheA, NRII, and KinA. Infect Immun, 1993 Feb, 61(2), 671 - 9 Effector mechanisms of intestinally induced immunity to Pseudomonas aeruginosa in the rat lung: role of neutrophils and leukotriene B4; Buret A et al.; This paper investigates the effector mechanisms of immune clearance in the lungs of rats immunized against mucoid Pseudomonas aeruginosa . After the gut-associated lymphoid tissue was primed and after a subsequent pulmonary challenge with live bacteria, significantly accelerated bacterial clearances from the lung and raised levels of anti-P . aeruginosa antibodies in sera (immunoglobulin G {IgG}, IgA, and IgM) and bronchoalveolar lavages (IgG and IgA) were observed for all immune animals . These changes were associated with enhanced recruitment, chemotaxis, chemokinesis, phagocytic indices, and chemiluminescence of pulmonary polymorphonuclear neutrophils (PMN) . In the alveolar spaces of immune animals, an increase in the level of PMN recruitment was not associated with higher levels of leukotriene B4 (LTB4) . In contrast, in nonimmune animals that were intratracheally infected with P . aeruginosa, the levels of recruitment and activity of alveolar PMN were lower than those in immune rats but PMN infiltration correlated with a significant increase in the synthesis of LTB4 in the alveolar space . In pulmonary tissue, LTB4 synthesis for both groups was elevated . These findings suggest that accelerated clearance of mucoid P . aeruginosa from the lungs of intestinally immunized rats is due at least in part to factors that induce the enhancement of PMN recruitment and activity in the alveolar space . The mediators that regulate this enhanced response remain unknown but do not seem to include LTB4 . The high levels of LTB4 measured in the bronchoalveolar lavages and pulmonary tissues from nonimmune animals infected with live bacteria implicate LTB4 as an important amplifier of the inflammatory response during acute pulmonary infections with mucoid P . aeruginosa in unimmunized hosts. Jpn J Antibiot, 1993 Feb, 46(2), 171 - 83 {Clinical evaluation of imipenem/cilastatin sodium and fosfomycin as second-line combination chemotherapy in severe infections associated with hematologic disorders}; Tsuda S et al.; Imipenem/cilastatin sodium (IPM/CS) which is a broad-spectrum agent against both Gram-positive and -negative bacteria was used in combination with fosfomycin (FOM) as a second-line chemotherapy for severe infections associated with hematologic disorders . FOM was partnered with IPM because FOM may enhance the bacteriocidal effects of IPM when given as pretreatment to IPM/CS therapy . Fifty two patients were treated with IPM/CS plus FOM . Of them, 41 were evaluated for effectiveness . Eleven patients were not evaluated: 4 were treated with a combination of other regimens such as cefixime, gamma-globulin, G-CSF and a large dose of methyl prednisolone; 2 were given IPM/CS plus FOM as a first choice; 3 were observed to have gastrointestinal side effects such as nausea which led to the discontinuation of the combination therapy; and 2 were thought to be suffering from not infectious but tumor fever . An excellent response was observed in 15 (36.6%) patients and a good response in 10 (24.4%), for a overall efficacy rate of 61.0% . Efficacies was 71.4% (5/7) in patients with sepsis, and 60.0% (9/15) in patients whose peripheral granulocyte count was below 100/microliters before chemotherapy . The elimination rates of Gram-positive and -negative bacteria were 57.1% (4/7) and 75.0% (6/8), respectively . In particular, 75.0% (3/4) of Pseudomonas aeruginosa identified were eliminated . Two patients who suffered from tumor fever, 2 who did not receive chemotherapy before the combination chemotherapy and 3 who did not receive a full course of the combination chemotherapy because of side effects, were included in the final evaluation of safety . Side effects were observed in 18 of 48 patients (37.5%) . In 1 patient, skin eruption occurred 3 days after the initiation of the combination chemotherapy . In 17 patients, gastrointestinal symptoms such as nausea and vomiting were identified after a few days of IPM/CS plus FOM administration . Degree's of the symptoms were mild, however . Therefore, the treatment was not withdrawn . No abnormal laboratory results such as eosinophilia, liver disfunction or renal disfunction were observed . These results show that IPM/CS plus FOM is effective as a second-line combination chemotherapy for the treatment of severe infections in patients with hematologic disorders. APMIS, 1993 Feb, 101(2), 168 - 75 Comparison of genome fingerprinting with conventional typing methods used on Pseudomonas aeruginosa isolates from cystic fibrosis patients; Ojeniyi B et al.; Two hundred Pseudomonas aeruginosa serial isolates from 61 cystic fibrosis patients were examined using restriction fragment length polymorphism in connection with pulsed field gel electrophoresis . A comparison was made of results obtained by genome fingerprinting and by conventional typing methods . It was possible to subdivide the majority of the genome types with the conventional typing methods, indicating the likelihood of bacterial phenotypes occurring in the lung of the cystic fibrosis patient . Two clusters of strains were observed among the 200 P . aeruginosa isolates from the 61 patients . Strains belonging to one cluster were present in 26 (42.6%) of the 61 patients . Strains belonging to the other cluster were present in 11 (18.0%) of the 61 patients . The occurrence of these clusters indicates that cross-infection has taken place among CF patients attending the Danish Cystic Fibrosis Centre . Conventional typing methods are based on the presence of specific bacterial surface structures . Therefore, conventional typing methods may sometimes lead to wrong classification of isolates from cystic fibrosis patients, especially if applied alone . A combination of two to six methods decreased the reproducibility of the typing results . The best combination was genome fingerprinting and phage typing, which yielded a reproducibility of 82.5% . Each time a method is added, the reproducibility decreases by an average of 14.4%. Antibiot Khimioter, 1993 Feb-Mar, 38(2-3), 42 - 4 {Use ciprofloxacin in children with mucoviscidosis}; Smirnova EIu et al.; Ciprofloxacin was used in treatment of 13 children aged 6 to 18 years with mucoviscidosis and exacerbation of the bronchopulmonary process . The dose of the drug was 20 to 30 mg/kg a day when administered orally or 15 mg/kg a day when administered at first intravenously and then orally . The treatment course averaged 14 days . The indications to the drug use were: severe processes of mucoviscidosis and chronic colonization of the bronchial mucosa and lung tissues with Pseudomonas aeruginosa (mucoid or nonmucoid form) sensitive to ciprofloxacin and resistant to other antibiotics . The trials showed that ciprofloxacin was highly efficient: the state of the patients improved and the inflammation index of the total blood count normalized . However, eradication of P . aeruginosa from the respiratory tracts was not observed . The drug allergy in 1 patient and a transient increase in the level of transaminases in 5 patients as the adverse reactions were recorded. APMIS, 1993 Feb, 101(2), 101 - 12 Antibodies from chronically infected cystic fibrosis patients react with lipopolysaccharides extracted by new micromethods from all serotypes of Pseudomonas aeruginosa; Fomsgaard A et al.; Micromethods were developed to extract lipopolysaccharide (LPS, endotoxin) from single bacterial colonies of the 20 recognized Pseudomonas aeruginosa type strains . The appearance of these LPSs in polyacrylamide gel electrophoresis (PAGE) and their reactivity with serum of cystic fibrosis (CF) patients chronically infected with P . aeruginosa was studied . Silver staining of LPS after PAGE showed that 13 of the P . aeruginosa LPSs had high numbers of O-repeating units arranged in 1-4 clusters of banding . Low-molecular-weight LPS fractions were more prominent in six of the serotype strains, of which O:7 and O:14 appeared semi-rough . Corresponding immunoblots using the CF sera showed LPS patterns very similar to the silver-stained appearance, indicating an immune reaction to all P . aeruginosa LPS including that from the newly discovered O:18, O:19 and O:20 . This was unexpected since only a few serotype strains (mostly O:3, O:6 and O:9) had been isolated from the patients . Absorption experiments using purified and chemically defined P . aeruginosa rough LPS and smooth LPS suggested these immune reactions were due to antibodies cross-reactive to core/lipid A as well as to lower molecular weight O-polysaccharides or "A-bands" . However, in some cases O:3, O:6, and O:9 LPSs were also found to contain additional distinct O-epitopes . Immune recognition of various polyagglutinable P . aeruginosa LPSs seemed also to be caused by cross-reactive antibodies . The described microextraction methods, followed by PAGE and silver staining or immunoblotting, are easy and convenient techniques with which to study antibodies against LPS epitopes and to screen for LPS phenotypic appearance using only a few bacterial colonies from larger numbers of Gram-negative bacterial strains. Chest, 1993 Feb, 103(2), 466 - 71 Pseudomonas cepacia in lung transplant recipients with cystic fibrosis; Snell GI et al.; Twenty-four isolated double lung transplants (LTXs) have been performed in 22 patients with cystic fibrosis, with a follow-up of 4 to 47 months . Prior to LTX, all patients were colonized with Pseudomonas aeruginosa, and ten patients were also colonized with Pseudomonas cepacia . Both organisms were specifically sought before LTX . All patients who grew P cepacia before LTX did so after LTX . Five additional patients only grew this bacterium after LTX . There was no difference between those who grew P cepacia and those who did not in terms of data before LTX for age, weight, pulmonary function, and 6-min walk . After LTX, 7 of the 15 patients who had ever grown P cepacia died . No patient who grew only P aeruginosa died . The median survival in the subgroup with P cepacia was 28 days . Five of the seven died as a direct result of P cepacia pneumonia and sepsis . One died of cyclosporin A (cyclosporine) neurotoxicity with concurrent P cepacia pneumonia, and one died at the time of a retransplant for graft failure (associated with three bouts of P cepacia pneumonia and cytomegalovirus) . Four of seven had not grown this bacterium before LTX . There were no perioperative factors, including antibiotic choices, that distinguished survivors and nonsurvivors . Overall 1-year survival is about 70 percent (15/22) . Fourteen bouts of P cepacia pneumonia occurred in 12 patients . Four empyemas, one lung abscess, one suppurative pericarditis, and five cases of sinusitis were also due to this bacterium . In conclusion, P cepacia is responsible for excess morbidity and mortality after LTX . This organism is particularly lethal if isolated for the first time after LTX . Factors predicting its acquisition in this setting are unknown . While it is possible that the facial sinuses may act as an unrecognized reservoir or that patients or equipment provide a source, further study into the epidemiology of this organism is necessary to improve the survival of colonized patients undergoing LTX. Lancet, 1993 Jan 23, 341(8839), 189 - 93 Genetic determinants of airways' colonisation with Pseudomonas aeruginosa in cystic fibrosis; Kubesch P et al.; Exocrine pancreatic insufficiency and lung infection with Pseudomonas aeruginosa are major features of cystic fibrosis (CF) . This monogenic disease is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene . 267 children and adolescents with CF who were regularly seen at the same centre were assessed for an association of the CFTR mutation genotype with exocrine pancreatic function and the age of onset of chronic colonisation with P aeruginosa . The major mutation delta F508 accounted for 74% of CF alleles; 33 further CFTR mutations had been detected on the CF chromosomes of the study population by June, 1992 . With the exception of delta F508/R347P compound heterozygotes, patients of the same mutation genotype were either pancreas insufficient (PI) or pancreas sufficient (PS) . The age-specific colonisation rates with P aeruginosa were significantly lower in PS than in PI patients . The missense and splice site mutations that are "mild" CF alleles with respect to exocrine pancreatic function were also "low risk" alleles for the acquisition of P aeruginosa . On the other hand, the proportion of P aeruginosa-positive patients increased most rapidly in the PI delta F508 compound heterozygotes who were carrying a termination mutation in the nucleotide binding fold-encoding exons . Pancreatic status and the risk of chronic airways' colonisation with P aeruginosa are predisposed by the CFTR mutation genotype and can be differentiated by the type and location of the mutations in the CFTR gene. Biochemistry, 1993 Jan 19, 32(2), 509 - 15 Opossum serum alpha 1-proteinase inhibitor: purification, linear sequence, and resistance to inactivation by rattlesnake venom metalloproteinases; Catanese JJ et al.; Opossum (Didelphis virginiana) serum was fractionated with (NH4)2SO4 and then chromatographed on DEAE-Sepharose and phenyl-Sepharose . Affinity chromatography on a protein A-Sepharose-antibody column removed traces of opossum serum metalloproteinase inhibitors, and resulted in a homogeneous preparation of opossum alpha 1-proteinase inhibitor (alpha 1-PI) . The inhibitor is a single-chain glycoprotein (17.7% carbohydrate) with an estimated M(r) = 54,000 . An opossum liver cDNA library was immunoscreened, and clones containing cDNA encoding for the open reading frame for opossum alpha 1-PI were isolated . The cDNA inserts contained nucleotide sequences corresponding to the amino-terminal and an internal peptide sequence of opossum alpha 1-PI which had been separately determined by protein sequence analysis . The entire inserts coded for a protein consisting of a 21-residue signal peptide and a 389-residue mature protein . Opossum alpha 1-PI shows 51-58% identity with other mammalian alpha 1-PI amino acid sequences, and the conserved residues expected for a member for the serpin family have been retained . The carbohydrate attachment sites and the reactive site residues (M-S) of opossum alpha 1-PI are identical to those of human alpha 1-PI . Opossum alpha 1-PI formed stable enzyme/inhibitor complexes with trypsin, chymotrypsin, and human neutrophil elastase, but did not react with thrombin or with snake venom serine proteinases . Opossum alpha 1-PI was inactivated by papain or Pseudomonas aeruginosa elastase, and electrophoretic analysis of the reaction products indicated limited proteolysis in the reactive site loop of the inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS) Biochim Biophys Acta, 1993 Jan 18, 1145(1), 42 - 50 Interdigitated gel phase bilayers formed by unsaturated synthetic and bacterial glycerolipids in the presence of polymyxin B and glycerol; Boggs JM et al.; The ability of synthetic phosphoglycerolipids with a cis mono-unsaturated acyl chain in the 2-position and a saturated chain in the 1-position of glycerol to form interdigitated gel phase bilayers in the presence of amphipathic substances was monitored using a fatty acid spin label, 16-doxylstearic acid, and a phosphatidylglycerol spin label containing 16-doxylstearic acid . These spin labels become significantly more motionally restricted in an interdigitated gel phase bilayer than in a non-interdigitated gel phase bilayer . The results indicated that polymyxin B and polymyxin B nonapeptide caused interdigitation of 1-palmitoyl,2-oleoyl-phosphatidylglycerol (POPG) and glycerol caused interdigitation of 1-stearoyl,2-oleoyl-phosphatidylcholine (SOPC), similar to their effects on disaturated lipids . The fluidity gradient present in non-interdigitated gel phase bilayers was abolished . However, glycerol did not cause POPG to become interdigitated, in contrast to SOPC . We reported earlier that there is a kinetic barrier to interdigitation of saturated PG in the presence of glycerol, in contrast to saturated PC . This barrier is even greater for the unsaturated species of PG . Furthermore, these compounds lowered the gel to liquid-crystalline phase transition temperatures of the unsaturated lipids more than of saturated lipids suggesting that the interdigitated bilayer of the former may be less ordered or less stable than that of the latter . Since polymyxin B is an antibiotic we also examined its effect on a lipid extract from the Gram-negative bacteria Pseudomonas aeruginosa in order to assess whether interdigitation might be involved in its mechanism of bactericidal or bacteriostatic effect . Polymyxin B and polymyxin B nonapeptide also caused motional restriction of a small percentage (about 13% at -2 degrees C and 25% at -14 degrees C for polymyxin B) of the spin label in the lipid extract at low temperatures, where the lipid is in the gel phase, consistent with formation of a small domain of interdigitated bilayer lipid . However, the degree of immobilization was less than that in the interdigitated bilayers of the synthetic unsaturated lipids . This may be a result of the heterogeneous nature of the lipids in the extract . However, it cannot be ruled out that the motional restriction of the spin label in this extract may be caused by something other than interdigitation . Thus the results with the lipid extract are less conclusive of interdigitation than for the synthetic lipids . A motionally restricted population was not detectable at higher temperatures.(ABSTRACT TRUNCATED AT 400 WORDS) Folia Microbiol (Praha), 1993, 38(1), 25 - 8 Antimicrobial activity determined in strains of Bacillus circulans cluster; Perez C et al.; Wild-type strains of the genus Bacillus were screened for antimicrobial activity . Two strains exhibited antimicrobial activity against Micrococcus luteus and were identified as Bacillus polymyxa MIR-23 and Bacillus circulans MIR-13 . Bacillus polymyxa MIR-23 was active against Escherichia coli, Pseudomonas aeruginosa and Aspergillus niger, whereas Bacillus circulans MIR-13 did not show activity against these microorganisms . Bacillus subtilis ATCC 6633 and B . polymyxa ATCC 10401 were used as standard antibiotic-producer strain and showed different antimicrobial profiles and yields from B . polymyxa MIR-23 . The different antimicrobial profile of the two selected strains could possibly be used as a taxonomic marker. Eur Arch Otorhinolaryngol, 1993, 250 Suppl 1, S7 - 11 Concentrations of ofloxacin in ear and nasal tissues; Tolsdorff P; The results of two kinetic studies examining soft tissue, cartilage and bone after uptake of oral ofloxacin {administered as 200 mg twice daily (study I/nose) or 400 mg once daily (study II/ear)} show that antibiotic concentrations lie within the therapeutic range . Findings demonstrate that 400 mg ofloxacin daily is a compliance-enhancing and effective approach to the treatment of ENT-related infections, in particular those caused by problem organisms such as Pseudomonas aeruginosa. Eur Arch Otorhinolaryngol, 1993, 250 Suppl 1, S15 - 7 Granulation tissue concentrations of ofloxacin after oral administration in invasive external otitis; Himmelfarb MZ et al.; Following the fourth dose of 400 mg orally administered ofloxacin, simultaneous external ear canal granulation tissue and serum ofloxacin concentrations were estimated in 15 patients with invasive external otitis . The granulation tissue concentration was 2.2 (range 1.17-4.34) times higher than the serum concentration and 3.73 (range 1.95-11.00) times higher than the MIC90 of ofloxacin against Pseudomonas aeruginosa. Scand J Infect Dis, 1993, 25(1), 81 - 3 The treatment of Pseudomonas aeruginosa meningitis--old regime or newer drugs? Saha V, Stansfield R, Masterton R, Eden T. Currently intravenous ceftazidime with or without an aminoglycoside or alternatively ciprofloxacin are the recommended antibiotics of choice in Pseudomonas aeruginosa meningitis . A case of atraumatic, spontaneous Ps . aeruginosa meningitis in a child with acute lymphoblastic leukaemia is described . Despite the organism demonstrating in vitro sensitivity to ceftazidime, netilmicin and ciprofloxacin, intravenous therapy with these drugs failed to sterilise the cerebrospinal fluid (CSF) . Both netilmicin and ciprofloxacin failed to attain therapeutic levels in the CSF . Intrathecal aminoglycoside therapy via an intraventricular reservoir was successful in eradicating the infection . In children with meningitis due to Ps . aeruginosa where intravenous therapy is unsuccessful despite in vitro sensitivity to recommended antibiotics; intraventricular medications should be commenced as soon as possible. Cornea, 1993 Jan, 12(1), 10 - 8 Effect of Pseudomonas aeruginosa concentration in experimental contact lens-related microbial keratitis; Lawin-Brussel CA et al.; Pseudomonas aeruginosa adherence in vitro to perfilcon A (ionic, 71% H2O) extended wear soft contact lenses--both new and after 7 days of continuous wear on closed rabbit eyes--was found to be related directly to the bacterial concentration in the contaminating solution . Thirty rabbits wore perfilcon A lenses for 7 days with complete lid closure to mimic contact lens overwear . After 7 days, conjunctival cultures showed no growth of pathogens, but all corneas had developed epithelial cell exfoliation and/or epithelial defects and stromal edema . The lenses were then incubated in various concentrations (10(7), 10(6), 10(5), 10(4), and 10(2) colony-forming units per milliliter or saline control; n = 5/group) of P . aeruginosa suspensions and replaced on their respective corneas with tarsorrhaphies for an additional 48 h . By day 9, corneal thickness had increased significantly, and P . aeruginosa keratitis had developed in 13 of 25 bacterially exposed eyes but not in 5 control eyes . Although with decreasing P . aeruginosa concentration the prevalence of ulcerative microbial keratitis also decreased, the initial concentration of bacteria or the initial extent of soft contact lens-induced corneal damage had no influence on the ultimate clinical severity of the disease. Jpn J Antibiot, 1993 Jan, 46(1), 67 - 74 {Pharmacokinetic and clinical studies on DQ-2556 in the gynecological field}; Yasuda J et al.; Pharmacokinetic and clinical studies on DQ-2556, a new cephem antibiotic, in obstetrics and gynecology were performed and following results were obtained . Concentrations of DQ-2556 were determined in serum, internal genital organs and retroperitoneal exudate after single intravenous administration (i.v.) or drip infusion (d.i.v.) of 1.0 g . Serum levels following i.v . were approximately 30 micrograms/ml at 1 hour, 14 micrograms/ml at 3 hours 30 minutes, and concentrations in internal genital organs including oviduct, ovary, endometrium, myometrium, cervix uteri and portio vaginalis reached approximately 50% to 70% levels of serum concentration . The mean concentration (n = 6) in the retroperitoneal exudate after d.i.v . of 1.0 g following radical hysterectomy were about 20 micrograms/ml, 23 micrograms/ml, 14 micrograms/ml and 8 micrograms/ml at 1 hour, 2 hours 30 minutes, 4 hours 30 minutes and 6 hours 30 minutes, respectively . In clinical trials, DQ-2556 (2.0 g b.i.d . for daily dose) was given in 5 patients with gynecological infections such as pyometra (1 case), salpingitis (1), retroperitoneal space infection (2), pelvic peritonitis (1) . The clinical results were evaluated as good in 3 cases and poor in 2 cases including a case with salpingitis infected by Pseudomonas aeruginosa and the other with pelvic peritonitis caused by Methicillin-resistant Staphylococcus aureus . Bacteriologically, 11 organisms were isolated from patients, and eradication rate was 54.5% . Neither side effect nor abnormal laboratory test result was observed . Thus, DQ-2556 appears to be effective for gynecological infections, and the good results were supported by good penetration of the compound into tissues of internal genital organs and retroperitoneal exudate after i.v . or d.i.v. Chirality, 1993, 5(1), 24 - 30 Stereoselective hydrolysis of triglycerides by animal and microbial lipases; Rogalska E et al.; In the present paper, a study on the stereoselectivity of 25 lipases of animal and microbial origin towards homogeneous prochiral triglycerides is presented . All the lipases tested catalyse the hydrolysis of the chemically alike but sterically nonequivalent ester groups in trioctanoin and triolein with different degrees of stereobias, depending on the fatty acyl chain length of the substrate (Rogalska et al., J . Biol . Chem . 256:20271-20276, 1990) . Hydrolysis of the sn-2 ester group is catalysed by very few lipases and only Candida antarctica A shows a clear preference for this position . Most of the lipases investigated (12 with trioctanoin and 16 with triolein) showed a preference for the sn-1 position . Using trioctanoin as substrate we observed a total stereoselectivity for position sn-1 with Pseudomonas sp . and Pseudomonas aeruginosa and for position sn-3 with Candida antarctica B . This was not the case with triolein as substrate . Among the 23 lipases studied here and the other two lipases described previously (Rogalska et al., J . Biol . Chem . 256:20271-20276, 1990), 17 show a higher stereoselectivity with trioctanoin than with triolein . With guinea pig pancreatic lipase and with three mold lipases (Geotrichum candidum M, Geotrichum candidum A, and Candida antarctica B), the preference switches from sn-3 to sn-1 when the acyl chain length increases from eight to 18 carbon atoms . The main conclusion to emerge from the present study is that the specific stereopreference of each lipase for a given substrate under given lipolytic conditions can be said to be its fingerprint. Toxicon, 1993 Jan, 31(1), 27 - 34 Immunosuppressive effects of Pseudomonas aeruginosa exotoxin A on human B-lymphocytes; Vidal DR et al.; In this study we investigated the effects of exotoxin A on proliferation and differentiation of human B-cells in vitro . Exotoxin A at a concentration of 1 microgram/ml inhibited the proliferation of B-cells preactivated by insolubilized anti-IgM antibody or by formalinized Staphylococcus aureus particles, plus IL-2 or IL-4 . B-cell blasts obtained after preactivation of tonsillar B-cells produce IgG and IgM in culture supernatants, and this Ig production is enhanced by IL-2 or IL-4 . Exotoxin A inhibited the production of IgG and IgM by the B-blasts at the concentration of 1 microgram/ml. Arch Dis Child, 1993 Jan, 68(1), 120 - 2 Cystic fibrosis in Asians; Bowler IM et al.; The clinical course of cystic fibrosis in nine Pakistani Asians was compared with 18 non-Asian age and sex matched controls . The Asian patients grew Pseudomonas aeruginosa at an earlier age (4.0 v 7.5 years), tended to have lower respiratory function test results (forced vital capacity 58.5 v 76.8% predicted; forced expiratory volume in one second 79.8 v 100.3% predicted), and had significantly greater concentrations of immunoglobulin IgG (13.4 v 10.1 g/l) . They had a lower weight for age (78.4 v 95.7%) and weight for height (90 v 98.5%) despite similar intakes of dietary energy . Four of the nine Asians carried the delta F508 mutation compared with 17 of 18 controls . All the Asian patients were born in the UK; seven of their mothers were born in Pakistan and had moderate or severe difficulties with the English language . It is concluded that Asian patients may have a more severe clinical course than matched controls and that genetic and environmental factors may be contributory. Thorax, 1993 Jan, 48(1), 70 - 4 Pulmonary gangrene and the air crescent sign; Reich JM; BACKGROUND: A study was carried out to increase familiarity with the aetiology, pathogenesis, and radiographic features that characterise pulmonary gangrene . PATIENTS: Four patients with one of the disorders vasoinvasive aspergillosis, infarcted tuberculous cavity, chronic necrotising aspergillosis, and gangrene due to Pseudomonas aeruginosa were selected because they showed the variations of the typical radiographic pattern and illustrated the pathogenesis . A fifth case is also presented, in which pulmonary gangrene was simulated by the invagination of a loculated pleural effusion into the wall of a contiguous lung abscess . CONCLUSIONS: Evolution of a crescent or rim of air within a homogeneous shadow is the feature that both heralds the development and facilitates the recognition of pulmonary gangrene . It is most often the result of vascular thrombosis induced by the infecting organism . The outcome of treatment is often unfavourable, principally because of the severity of the predisposing systemic or local underlying disorder, although a delay in diagnosis, possibly due to unfamiliarity with the radiographic pattern, may have contributed to the adverse out