Pseudomonas aeruginosa

Chem Pharm Bull (Tokyo), 1992 Sep, 40(9), 2555 - 6
Biologically active complexes of nickel(II), copper(II) and zinc(II) with Schiff-base ligand derived from the reaction of 2-aminopyridine and pyrrol-2-carboxaldehyde--their synthesis and characterisation; Chohan ZH et al.; A new Schiff-base ligand N-(2'-pyrrylmethylidene)2-aminopyrimidine derived from the reaction of 2-amino pyrimidine and pyrrol-2-carboxaldehyde and its nickel(II), copper(II) and zinc(II) complexes have been synthesised and characterised on the basis of elemental analysis, molar conductance, infrared, electronic and proton nuclear magnetic resonance (1H-NMR) and magnetic susceptibility data . The ligand and its complexes when screened for antibacterial activity against bacterial species such as, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae . In all cases, the activity substantially increased on complexation with metals.

Appl Environ Microbiol, 1992 Sep, 58(9), 2886 - 93
Metal regulation of siderophore synthesis in Pseudomonas aeruginosa and functional effects of siderophore-metal complexes; Visca P et al.; Pseudomonas aeruginosa synthesizes two siderophores, pyochelin and pyoverdin, characterized by widely different structures, physicochemical properties, and affinities for Fe(III) . Titration experiments showed that pyochelin, which is endowed with a relatively low affinity for Fe(III), binds other transition metals, such as Cu(II), Co(II), Mo(VI), and Ni(II), with appreciable affinity . In line with these observations, Fe(III) and Co(II) at 10 microM or Mo(VI), Ni(II), and Cu(II) at 100 microM repressed pyochelin synthesis and reduced expression of iron-regulated outer membrane proteins of 75, 68, and 14 kDa . In contrast, pyoverdin synthesis and expression of the 80-kDa receptor protein were affected only by Fe(III) . All of the metals tested, except Mo(VI), significantly promoted P . aeruginosa growth in metal-poor medium; Mo(VI), Ni(II), and Co(II) were more efficient as pyochelin complexes than the free metal ions and the siderophore . The observed correlation between the affinity of pyochelin for Fe(III), Co(II), and Mo(VI) and the functional effects of these metals indicates that pyochelin may play a role in their delivery to P . aeruginosa.

Pediatr Pulmonol, 1992 Sep, 14(1), 44 - 51
IgG subclass antibody responses to alginate from Pseudomonas aeruginosa in patients with cystic fibrosis and chronic P . aeruginosa infection; Pressler T et al.; Chronic bronchopulmonary infection with alginate-producing, mucoid Pseudomonas aeruginosa is characteristically associated with cystic fibrosis (CF) . A significant correlation between the antibody response to alginate and poor lung function has been reported . Enzyme-linked immunosorbent assays were developed for the quantitation of human IgG1, IgG2, IgG3, and IgG4 antibodies to P . aeruginosa alginate . We investigated the pattern of IgG subclass antibodies against P . aeruginosa alginate in serum of patients with CF, others with chronic P . aeruginosa infection, and healthy controls . Healthy controls and patients with CF, before they acquired P . aeruginosa infection, had no or very low titers of antibodies against P . aeruginosa alginate . The latter with chronic infection had significantly higher antibody levels than all others groups, including patients with chronic P . aeruginosa infection but no CF . CF with chronic P . aeruginosa infection led to an inverse correlation between lung function parameters and levels of IgG3 and IgG4 . Fifty-seven patients with CF have been followed for an average of 12 years with multiple antibody assays covering the preinfection, early, and late stage of chronic infection . All of them developed IgG1 and IgG3 antibodies to alginate at the start of infection . IgG2 antibodies developed later and showed only a slow increase during the chronic infection . Patients who died had significantly higher IgG2 anti-alginate antibody levels than other investigated groups . Elevated levels of IgG2 and IgG3 antibodies to P . aeruginosa alginate are a sign of poor prognosis in CF.

J Antibiot (Tokyo), 1992 Sep, 45(9), 1526 - 32
Role of the aminothiadiazolyl group in the antipseudomonal activity of cefclidin; Watanabe N et al.; Cefclidin (E1040), which has an aminothiadiazolyl group in the 7 beta-side chain, showed about four-fold higher activity against Pseudomonas aeruginosa than its aminothiazolyl counterpart . Cefclidin had lower affinity and a higher Vmax value for the chromosomal type I beta-lactamase (cephalosporinase) from P . aeruginosa than its aminothiazolyl counterpart . No differences between the affinities of both compounds for the most of the sensitive essential PBPs were observed . Hydrophilicity of cefclidin was higher than that of its counterpart . The antipseudomonal activity of cefclidin, which was increased by the introduction of the aminothiadiazolyl group, was suggested to have resulted mainly from higher resistance to cephalosporinase hydrolysis at pharmacologically relevant low concentrations due to its low affinity for cephalosporinase, and secondarily from good penetration of cefclidin through the outer membrane due to increased hydrophilicity.

Cornea, 1992 Sep, 11(5), 393 - 7
Fibrin-enmeshed tobramycin liposomes: single application topical therapy of Pseudomonas keratitis; Frucht-Perry J et al.; Treatment of bacterial keratitis requires frequent application of topical antibiotics . We studied the efficacy of a single topical administration of tobramycin incorporated in large multivesicular liposomes and enmeshed in a fibrin sealant on rabbit corneas infected with Pseudomonas aeruginosa . One cornea each of 25 New Zealand albino rabbits was infected with P . aeruginosa . Twenty-four hours later, the animals were randomly divided into five groups of five . Group A received single hourly drops (50 microliters) of fortified tobramycin (14.5 mg/ml, total of 17.4 mg) . Group B received a single topical application of 3.5 mg tobramycin, in 0.1 ml multivesicular liposomes, enmeshed in a fibrin sealant with an overlaying bandage contact lens . Group C was treated in the same manner as group B without the addition of fibrin sealant . Groups D and E served as nondrug-treated controls, with group D receiving topical fibrin-enmeshed liposomes devoid of tobramycin and group E receiving hourly topical balanced salt solution (BSS) drops . All animals were killed 24 h after initiation of therapy . Significantly fewer colonies of Pseudomonas were present in corneas of all three treated groups, as compared with the two nondrug-treated control groups (p less than 0.02) . There were significantly fewer colonies of Pseudomonas in groups A and B as compared with group C (p less than 0.02) . No significant difference was noted between a single administration of topical fibrinen-meshed tobramycin-encapsulated liposomes (group B) and 24 doses of hourly fortified topical tobramycin (group A, p greater than 0.05) . Tobramycin-encapsulated megaliposomes may serve as a useful adjunct in treatment of Pseudomonas keratitis.

Acta Paediatr, 1992 Sep, 81(9), 720 - 2
Noma neonatorum: an unusual case of noma involving a full-term neonate; Lin JY et al.; Noma neonatorum is a gangrenous process that occurs in the oral, nasal or anal area and occasionally the eyelids and scrotum of the newborn . The disease is caused by Pseudomonas aeruginosa and usually affects premature ill babies during the first few weeks of life . A full-term neonate with nasal and scrotal noma is uncommon and is therefore reported.

Arch Dis Child, 1992 Sep, 67(9), 1086 - 8
The value of serum IgG titres against Pseudomonas aeruginosa in the management of early pseudomonal infection in cystic fibrosis; Brett MM et al.; We report the results of a clinical trial . Patients enrolled had serum IgG titres against Pseudomonas aeruginosa above the control range . Assignment to the observation or treatment group was by minimisation . Significant signs or symptoms in any patient prompted antipseudomonal treatment . In addition, the treatment group received antipseudomonal treatment at intervals of four months until the serum IgG titre returned to the control range . P aeruginosa was isolated intermittently from patients in the main trial . Nineteen patients were enrolled (12 observation, seven treatment) . After one year in the trial changes in parameters studied, including forced expiratory volume in one second, IgG titre, serum IgG concentrations, and frequency of P aeruginosa isolation had improved in the treated group and worsened in the observation group.

Antimicrob Agents Chemother, 1992 Sep, 36(9), 1951 - 7
Adaptive resistance following single doses of gentamicin in a dynamic in vitro model; Barclay ML et al.; Adaptive resistance is a phenomenon recently described for Pseudomonas aeruginosa and other gram-negative bacilli following exposure to aminoglycoside antibiotics . It is a reversible form of resistance which develops within 1 to 2 h of initial exposure to an aminoglycoside and disappears several hours after removal of the antibiotic . We investigated adaptive resistance in P . aeruginosa ATCC 27853 following single doses of gentamicin by using a dynamic in vitro model which mimics in vivo pharmacokinetics . The initial peak gentamicin concentrations were 2.5, 8, and 25 mg/liter, and these were followed by an exponential decay in the concentration, with a half-life of 2.5 h . The degree of adaptive resistance was greater and the duration was longer with higher initial gentamicin concentrations . Maximal adaptive resistance occurred between 2 and 10 h following 8 mg/liter and between 2 and 16 h following 25 mg/liter . Full recovery of susceptibility occurred at approximately 36, 39, and 43 h following 2.5, 8, and 25 mg/liter, respectively, at which times the gentamicin concentrations were extremely low . Longer dosing intervals for aminoglycosides may improve efficacy by allowing time for adaptive resistance to resolve.

Antimicrob Agents Chemother, 1992 Sep, 36(9), 1922 - 7
Potential effects of erythromycin on host defense systems and virulence of Pseudomonas aeruginosa; Hirakata Y et al.; We evaluated several potential effects of erythromycin (EM) on host defense systems and the virulence of Pseudomonas aeruginosa . Peritoneal macrophages obtained from mice given 250 mg of EM per kg of body weight for 7 days by the intraperitoneal, intravenous, subcutaneous, or oral route produced significantly greater amounts of thymocyte-activating factors . These data suggest that EM enhances the in vivo production of cytokines, such as interleukins 1 and 6 . Treatment of P . aeruginosa D4 with subinhibitory concentrations of EM enhanced the association of bacteria with murine Kupffer cells in vitro and increased bacterial clearance from the blood in mice . EM suppressed the in vitro production of exotoxin A, total protease, elastase, and phospholipase C by P . aeruginosa D4; exotoxin A production by P . aeruginosa PA-103; and total protease production by P . aeruginosa B16 and PAO1 in a generally dose-dependent manner . These data demonstrate that EM produces various effects in addition to its direct antimicrobial activity, suggesting that it has potential as an immunomodulator or bacterial virulence-suppressing agent against P . aeruginosa and other infections.

Antimicrob Agents Chemother, 1992 Sep, 36(9), 1902 - 8
Diffusion of meropenem and imipenem through the outer membrane of Escherichia coli K-12 and correlation with their antibacterial activities; Cornaglia G et al.; The outer membrane permeability to meropenem and imipenem in Escherichia coli K-12 was investigated, and its porin-deficient mutants were transformed with a constructed vector carrying the carbapenem-hydrolyzing CphA metallo-beta-lactamase gene . By using the method of Zimmermann and Rosselet, meropenem was shown to penetrate through the outer membrane of E . coli K-12 five times faster than cephaloridine but twice as slowly as imipenem . Lack of one or both porins significantly reduced the penetration of both carbapenems . No evidence of specific porin pathways of the type described in Pseudomonas aeruginosa was found . Despite its slower penetration, meropenem was two to eight times more active than imipenem against both parent and porin-defective mutants, whether harbouring CphA beta-lactamase or not . Meropenem was also more active than imipenem against E . coli DC2, a strain with a breakdown in the outer membrane permeability which made periplasmic concentrations of beta-lactams similar to the external concentrations . In this strain, meropenem caused a more than 50% reduction in cell number increase at a concentration very close to the 50% inhibitory concentration for penicillin-binding protein type 2 (PBP 2), whereas imipenem, at the same concentration, did not significantly inhibit cell growth . This result was explained by the higher affinity of meropenem for PBP 3 compared with imipenem and supports the conclusion that synergistic inhibition of both PBPs was the main mechanism in the better antibacterial activity of meropenem.

Antimicrob Agents Chemother, 1992 Sep, 36(9), 1847 - 51
Cross-resistance to meropenem, cephems, and quinolones in Pseudomonas aeruginosa; Masuda N et al.; Multiple-drug-resistant mutants were isolated from Pseudomonas aeruginosa PAO1 on agar plates containing ofloxacin and cefsulodin . These mutants were four to eight times more resistant to meropenem, cephems, carbenicillin, quinolones, tetracycline, and chloramphenicol than the parent strain was . In contrast, these mutants showed no significant changes in their susceptibilities to all carbapenems except meropenem . In these mutants, the amounts of an outer membrane protein with an apparent molecular weight of 49,000 (designated OprM) were increased compared with the amount in PAO1 . Multiple-drug-resistant mutants of this type were also isolated from PAO1 on agar plates containing meropenem . Approximately 5% of clinical isolates showed cross-resistance to meropenem, cephems, and quinolones, concomitant with overproduction of OprM . Moreover, these two phenotypes, i.e., multiple-drug resistance and overproduction of OprM, were cotransferable by transduction . These data suggest that overproduction of OprM is associated with cross-resistance to meropenem, cephems, and quinolones in P . aeruginosa . The ofloxacin-cefsulodin-resistant mutant required higher concentrations of meropenem to induce beta-lactamase than PAO1 did, indicating the possibility that this mutation involves decreased outer membrane permeability to meropenem.

Ann Pediatr (Paris), 1992 Sep, 39(7), 443 - 6
{Gangrenous ecthyma of the diaper area in infants}; Taieb A et al.; Ecthyma gangrenosum due to Pseudomonas aeruginosa is a skin infection in which necrotic ulcerations surrounded by a red areola develop . The diaper area is the region most often involved in infants . Typically, ecthyma gangrenosum occurs in patients with septicemia and risk factors (chemotherapy, neutropenia) . However, transient bacteremia or an infection confined to the skin may be the cause in some patients, with maceration in the diaper area and previous antibiotic therapy as risk factors.

Mol Gen Genet, 1992 Sep, 234(3), 475 - 80
Molecular cloning, characterization and purification of ornithine carbamoyltransferase from Mycobacterium bovis BCG; Timm J et al.; A genomic library of Mycobacterium bovis BCG has been constructed by cloning DNA partially digested with Sau3A into the Escherichia coli expression vector pAS1 . The gene coding for ornithine carbamoyl-transferase (EC.2.1.3.3; OTCase), hereafter referred to as argF, was isolated from the library by complementation of a double argF-argI mutant of E . coli and its sequence was determined . The translation initiation codon used, GTG, was identified by comparing the amino acid sequence deduced from the gene with the N-terminal sequence of the corresponding purified protein . On this basis, the M . bovis BCG OTCase monomer consists of 307 amino acid residues and displays about 44% identity with other OTCases, the most closely related homologue being the anabolic enzyme of Pseudomonas aeruginosa . The native enzyme has an estimated molecular mass of 110 kDa, suggesting a trimeric structure as is the case for most of the anabolic OTCases known from various organisms.

Leber Magen Darm, 1992 Sep, 22(5), 173 - 6
{Antibiotic prevention and therapy of infectious complications in ERCP}; Sauter G et al.; Endoscopic retrograde cholangiopancreatography (ERCP) may be complicated by bacteremia, cholangitis, or biliary sepsis . Bacteremia during ERCP implies a potential risk of endocarditis in patients with valvular prostheses or a previous history of infectious endocarditis . For these patients antibiotic prophylaxis prior to ERCP is recommended . Cholangitis or biliary sepsis may develop after ERCP in patients with obstructed bile ducts . In these patients antibiotics should be administered until adequate drainage of biliary obstructions is achieved . Antibiotic prophylaxis and antibiotic therapy must consider the spectrum of micro-organisms which is normally found in each of these situations . Regarding bacteremias associated with ERCP gram-positive cocci predominate, whereas cholangitis and biliary sepsis are caused mainly by gram-negative rods like Escherichia coli, Pseudomonas aeruginosa, or Klebsiella spp.

J Am Acad Dermatol, 1992 Sep, 27(3), 415 - 8
Perineal ecthyma gangrenosum in infancy and early childhood: septicemic and nonsepticemic forms; Boisseau AM et al.; BACKGROUND: Ecthyma gangrenosum is characterized by necrotic ulcerations surrounded by an erythematous halo . It is secondary to Pseudomonas aeruginosa infection . Most lesions are located in the anogenital and axillary areas, but the route of infection is generally difficult to establish . OBJECTIVE: We report six children with perineal ecthyma gangrenosum and discuss predisposing factors, origin, and route of infection . METHODS: This was a retrospective clinical study . RESULTS: Three children had blood cultures positive for P . aeruginosa, and one died . Predisposing factors were present in all cases; two had received chemotherapy (neuroblastoma, acute lymphoblastic leukemia), and two had idiopathic granulocytopenia . The last two patients previously had received treatment with systemic antibiotics and had abnormal granulocyte killing several months later . CONCLUSION: Septicemic ecthyma gangrenosum can be rapidly fatal in young children and requires aggressive antibiotic therapy . Benign ecthyma gangrenosum in healthy infants may result from a modification of bowel microflora after antibiotic therapy in conjunction with maceration in the diaper area . However, careful evaluation and long-term follow-up must be done to detect neutropenia, functional abnormalities of granulocytes, or a possible immune deficiency.

Eur J Pediatr, 1992 Sep, 151(9), 684 - 7
Influence of the development of diabetes mellitus on clinical status in patients with cystic fibrosis; Lanng S et al.; The impact of pre-diabetes on clinical status was retrospectively studied in 38 cystic fibrosis (CF) patients with diabetes mellitus (DM) and 38 non-diabetic CF patients (control patients), matched in pairs for age, sex, and chronic Pseudomonas aeruginosa lung infection . Quarterly parameters of CF clinical status were collected for 6 years prior to the diagnosis of DM in the index case . Compared to the control patients, decreases in body weight, body mass index (BMI), forced expiratory volume in 1s (FEV1), and forced vital capacity (FVC) and an increase in the daily intake of pancreatic enzyme capsules were found in the pre-diabetic patients . Statistically significant differences in body weight, BMI, FEV1, FVC, and intake of pancreatic enzyme capsules between pre-diabetic and control patients emerged 4, 4, 1.25, 3 and 4.5 years prior to the diagnosis of DM, respectively . The number of lung infections did not differ between the two groups of patients . Thus, when DM develops in CF patients, an insidious decline in overall clinical status is observed for years prior to its diagnosis . Whether clinical deterioration in CF leads to DM, or pre-diabetes results in declining CF clinical status is presently unknown . Accumulating evidence suggests that the latter may be the case since insulin therapy seems to improve lung function in CF.

FEMS Microbiol Rev, 1992 Sep, 9(1), 73 - 90
Protein secretion in Pseudomonas aeruginosa; Tommassen J et al.; The Gram-negative bacterium Pseudomonas aeruginosa secretes many proteins into the extracellular medium . At least two distinct secretion pathways can be discerned . The majority of the exoproteins are secreted via a two-step mechanism . These proteins are first translocated across the inner membrane in a signal sequence-dependent fashion . The subsequent translocation across the outer membrane requires the products of at least 12 distinct xcp genes . The exact role of one of these proteins, the XcpA protein, has been resolved . It is a peptidase that is required for the processing of the precursors of four other Xcp proteins, thus allowing their assembly into the secretion apparatus . This peptidase is also required for the processing of the precursors of type IV pili subunits . Two other Xcp proteins, XcpR and XcpS, display extensive homology to proteins involved in pili biogenesis, which suggests that the assembly of the secretion apparatus and the biogenesis of type IV pili are related processes . The secretion of alkaline protease does not require the xcp gene products . This enzyme, which is encoded by the aprA gene, is not synthesized in a precursor form with an N-terminal signal sequence . Secretion across the two membranes probably takes place in one step at adhesion zones that may be constituted by three accessory proteins, designated AprD, AprE and AprF . The two secretion pathways found in P . aeruginosa appear to have disseminated widely among Gram-negative bacteria.

J Formos Med Assoc, 1992 Sep, 91(9), 879 - 85
Management of infected tibial intramedullary nailing using an organized treatment protocol; Ueng WN et al.; Twenty cases of osteomyelitis, following intramedullary nailing of tibial shaft fractures, were managed with a prospective treatment protocol, comprising intramedullary reaming debridement, antibiotic-bead depot, external skeletal fixation, microvascular muscle flap and early cancellous bone grafting . The follow-up period ranged from 25 to 48 months (average, 34.3 months) . Pseudomonas aeruginosa (37.5%) and Staphylococcus aureus (20.8%) were the organisms most commonly involved . There were eight united and 12 ununited fractures after reaming debridement surgery . Nineteen infections were initially arrested by one debridement . One infection was arrested by two Sequential debridements . All 12 ununited fractures were stabilized by Hoffmann unilateral external fixation until the fracture healed . The time spent in external fixation ranged from three to seven months (average, 5.2 months) . Early cancellous bone grafting was successfully accomplished for nine ununited fractures with major debridement bone loss . The average union time of the nine fractures with bone grafting was 6.5 months (range, from six to eight months) . We believe that this treatment protocol gives a predictable and rapid recovery . The complications were infection recurrence in two cases at the old tibial shaft fracture sites, minor Hoffmann pin tract infection in two cases and stiffness in two ankles and one knee.

Antimicrob Agents Chemother, 1992 Sep, 36(9), 1915 - 21
Tn21-specific structures in gram-negative bacteria from clinical isolates; Zuhlsdorf MT et al.; A total of 807 gram-negative clinical isolates were treated with five different probes: intragenic segments for the transposase gene tnpA; the resolvase gene tnpR; the modulator of the resolvase, tnpM; the integraselike factor gene tnpI; and a 20-mer oligonucleotide for the recombinational site of action for the integrase . A total of 8% of the isolates hybridized with all five Tn21-related probes, and another 11% represented transposons in which one or more of the tested genes were missing . This 11% included groups whose descriptions have been published as well as groups that have not yet been described . The not-yet-described groups include various deletion products and some precursor structures, as is predicted for the evolution of Tn21-like transposons . The integration system appears to be coupled with Tn21-like structures and yet independent from these structures, implying an independent evolution of this system from Tn21-like transposons . The structures were found with similar incidence levels in all species tested except Pseudomonas aeruginosa, for which a novel separate family of class II transposons has been described before.

Kansenshogaku Zasshi, 1992 Sep, 66(9), 1236 - 42
{Effect of azithromycin on human serum sensitivity of Pseudomonas aeruginosa}; Tateda K et al.; We examined the effect of azithromycin (AZM), a 15-membered azalide newly synthesized from erythromycin (EM), on serum sensitivity of 6 strains of Pseudomonas aeruginosa . Incubation for 48 h on agar with EM 12 micrograms/ml or AZM 1.6 micrograms/ml induced increased serum sensitivity in 2 of 6 strains (S-6, PA-103), but there were no changes in any strains with josamycin (JM) 12 micrograms/ml . Although EM 12 micrograms/ml induced increased serum sensitivity of S-6 after more than 36 h incubation, AZM 1.6 micrograms/ml induced increased serum sensitivity of this strain at 12 h incubation . AZM 0.8 microgram/ml (1/62.5 MIC) showed more potent activity to enhance serum sensitivity of S-6 than that of EM 12 micrograms/ml (1/8 MIC) after 48 h incubation . P . aeruginosa S-6 incubated with EM 12 micrograms/ml or AZM 1.6 micrograms/ml for 48 h was less hydrophobic than that of control bacteria, but there was little change in the hydrophobicity of the strain incubated with JM 12 micrograms/ml . These results show that AZM has more potent activity to enhance serum sensitivity of P . aeruginosa than that of EM . Since decrease of cell surface hydrophobicity of P . aeruginosa S-6 was correlated with increased serum sensitivity, EM and AZM may induce enhanced serum sensitivity by changing cell surface structure of P . aeruginosa.

Antimicrob Agents Chemother, 1992 Sep, 36(9), 2046 - 8
Interplay of impermeability and chromosomal beta-lactamase activity in imipenem-resistant Pseudomonas aeruginosa; Livermore DM; Mutational loss of the D2 porin causes imipenem resistance in Pseudomonas aeruginosa . It was found that this mechanism could function only when the chromosomal beta-lactamase was expressed . Mutants lacking both the beta-lactamase and the D2 porin were almost as susceptible as those that lacked the beta-lactamase but retained the porin . Thus, imipenem resistance reflected an interplay of the enzyme and impermeability, not either factor alone . These findings suggest that the activity of a carbapenem more beta-lactamase stable than imipenem should be less affected by the porin loss . Meropenem approached this behavior.

Biochem J, 1992 Sep 1, 286 ( Pt 2), 361 - 7
E.p.r . and magnetic circular dichroism spectroscopic characterization of bacterioferritin from Pseudomonas aeruginosa and Azotobacter vinelandii; Cheesman MR et al.; The e.p.r . and magnetic circular dichroism (m.c.d.) spectra of bacterioferritin (BFR) extracted from Pseudomonas aeruginosa and Azotobacter vinelandii have been studied over a wide temperature range down to liquid-helium temperature . The e.p.r . spectra show the presence of low-spin Fe3+ haem with g values of 2.86, 2.32, 1.48 (P . aeruginosa) and 2.88, 2.31, 1.46 (A . vinelandii), in both the presence and absence of the BFR core . Together with evidence from the porphyrin-to-Fe3+ charge-transfer band at 2240 and 2270 nm the axial haem ligands are identified as two methionines . The low-temperature m.c.d . spectra in the region 300-1000 nm of P . aeruginosa and A . vinelandii BFR are identical with one another and unaffected by removal of the iron core . Hence it can be concluded that the presence of the iron core has no detectable effect on the electronic states and on the stereochemistry of the haem group . This was unexpected, in view of the observations by Watt, Frankel, Papaefthymiou, Spartalian & Stiefel {(1986) Biochemistry 25, 4330-4336} that the redox potential of the haem group in A . vinelandii BFR shifts from -475 mV to -225 mV on removal of the core . The e.p.r . spectra of holoBFR show a broad symmetrical derivative-shaped band centred at g = 2.0 which decreases in bandwidth as the temperature is raised . This signal is assigned to the uncompensated electron spins of the iron core.

J Infect Dis, 1992 Sep, 166(3), 568 - 73
Enhanced release of elastase and oxidative inactivation of alpha-1-protease inhibitor by stimulated human neutrophils exposed to Pseudomonas aeruginosa pigment 1-hydroxyphenazine; Ras GJ et al.; The in vitro effects of the Pseudomonas aeruginosa-derived phenazine pigments pyocyanin and 1-hydroxyphenazine (1-hp) on neutrophil elastase release and myeloperoxidase-induced inactivation of alpha-1-protease inhibitor (alpha 1-PI) were investigated . 1-hp (6-25 microM), but not pyocyanin, caused a dose-dependent enhancement of elastase release by FMLP:cytochalasin B (CB)-activated human neutrophils . 1-hp (0.78-6.25 microM) also increased the oxidative inactivation of the elastase inhibitory capacity of alpha 1-PI exposed to FMLP:CB-activated neutrophils . Methionine, a scavenger of hypochlorous acid, completely protected alpha 1-PI from inactivation by stimulated neutrophils in the presence or absence of 1-hp . Similar protective effects were observed with sodium azide, an inhibitor of myeloperoxidase . P . aeruginosa-derived 1-hp may promote an elastase-antielastase imbalance in vivo by increasing the release of neutrophil elastase and by enhancing the oxidative inactivation of alpha 1-PI, thereby contributing to the development of tissue destruction in P . aeruginosa-infected patients.

Infect Immun, 1992 Sep, 60(9), 3771 - 9
Genetic analysis of Pseudomonas aeruginosa adherence: distinct genetic loci control attachment to epithelial cells and mucins; Simpson DA et al.; Infection of mucosal tissues by the opportunistic pathogen Pseudomonas aeruginosa is initiated by attachment of the bacterium to host tissues . To gain a better understanding of this interaction, we used two methods to isolate mutants of P . aeruginosa with altered adherence to cultured A549 cells and to mucins . First, from a population of nonpiliated mutants of P . aeruginosa mutagenized with transposon Tn5G, we have isolated variants that are defective in binding to both A549 cells and respiratory mucins . Using a cloned transposon plus flanking DNA from one such mutant as a DNA probe, we have isolated plasmids from a cosmid bank, which, upon reintroduction to the original mutants, restored adhesion to both A549 cells and mucin . The second strategy to identify genes involved in adhesion used mutagenesis of P . aeruginosa N1G, an rpoN mutant which is unable to bind to either A549 cells or mucin, with transposon Tn5 containing an outward-directed promoter . From this bank of mutagenized P . aeruginosa N1G, two classes of adhesion variants were isolated; one class attached to A549 cells and to mucin, and the other class restored binding of the rpoN mutant to mucin but not to A549 cells . These findings suggest that P . aeruginosa can express at least two adhesins distinct from pili, one recognizing receptors shared by epithelial cells and mucins and the other recognizing mucins alone.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1992 Sep, 8(3), 177 - 8, 246
{The pH value of granulating wound and skin graft in burn patients}; Chai JK; The relationship between pH of granulation of burn wound and take rate of skin graft was presented . The bacteria in the granulation tissue were also quantified . The results showed: (1) The optimal pH of granulation wound for the take of skin graft is 7.2-7.5; (2) pH of granulation of burn wound is related to quantity and species of bacteria in the granulation tissue . The wound pH is 6.7 or lower when the number of Escherichia coli or Staphylococcus aureus is over 10(7)/gm of granulation tissue . The wound pH is 8.0 when the number of Pseudomonas aeruginosa is 10(8)/gm of granulation tissue . Because the measurement of wound pH is rapid, simple and noninvasive, it might be useful in predicting the take rate of skin graft.

Eur J Clin Microbiol Infect Dis, 1992 Sep, 11(9), 817 - 22
Genome fingerprinting by pulsed-field gel electrophoresis and ribotyping to differentiate Pseudomonas aeruginosa serotype O11 strains; Poh CL et al.; The performance of ribotyping and pulsed-field gel electrophoresis was compared in the differentiation of a collection of 44 Pseudomonas aeruginosa serotype O11 strains isolated in seven hospitals in Singapore . Digestion of genomic DNA by EcoRI and SacI followed by Southern hybridization with the Pseudomonas aeruginosa 16S and 23S rRNA gene revealed seven distinct ribotypes . Ribotyping using a combination of both enzymes revealed 11 ribotypes . In contrast, electrophoretic analysis differentiated 41 different strain types among the 44 clinical isolates using either SpeI or DraI . Pulsed-field gel electrophoresis demonstrated greater sensitivity than ribotyping in the differentiation of Pseudomonas aeruginosa strains of the same ribotype and could thus be used alone in epidemiological investigations of hospital outbreaks of Pseudomonas aeruginosa serotype O11 infection.

Eur J Clin Microbiol Infect Dis, 1992 Sep, 11(9), 810 - 6
Multilocus enzyme electrophoresis of major O-antigen reference strains of Pseudomonas aeruginosa; Charnock C et al.; Multilocus enzyme electrophoresis was used to characterize 27 Pseudomonas aeruginosa serogroup reference strains used in the major O-antigen schemes according to which Pseudomonas aeruginosa has been typed . Sixteen enzyme loci were assayed, ten of which showed electrophoretic variation . Genetic diversity was expressed for each enzyme locus, and as the mean allelic diversity of loci . Ten electrophoretic types were identified among the strains . The genetic distance between pairs of electrophoretic types was expressed as the proportion of loci at which similar alleles occurred . More than 80% similarity was observed between any pair of electrophoretic types, reflecting the homogeneity of multilocus genotypes within this species . Similarity between electrophoretic types was represented in the form of a dendrogram and by multi-dimensional scaling . Three distinct clusters of electrophoretic types were revealed; within each the serogroups appeared to be randomly distributed.

J Mol Biol, 1992 Aug 20, 226(4), 943 - 57
RNA processing modulates the expression of the arcDABC operon in Pseudomonas aeruginosa; Gamper M et al.; Anaerobic growth of Pseudomonas aeruginosa on arginine depends on the arcDABC operon encoding the enzymes of the arginine deiminase pathway . The co-ordinate, anaerobic induction of these enzymes requires the FNR-like regulatory protein ANR, which activates the arc promoter lying upstream from arcD . By Northern hybridization experiments, three abundant arcA, arcAB and arcABC transcripts and three minor arcDA, arcDAB and arcDABC transcripts could be detected . The 5' ends of the arcA, arcAB and arcABC mRNAs were determined by S1 and primer extension mapping . These 5' ends appear to be generated by endonucleolytic cleavage (processing) in arcD mRNA rather than by a second promoter; this was concluded from the effects of insertion and deletion mutations in arcD . Intergenic inverted repeats between arcA and arcB as well as between arcB and arcC were shown to be involved in the formation of 3' ends of arc transcripts . Deletion of either intergenic region in the P . aeruginosa chromosome led to the loss of the arcA or arcAB transcript, respectively . Dot blot experiments revealed that arc mRNAs extracted from the wild-type strain had similar chemical half-lives in the arcA, arcB and arcC regions, ranging from 16 to 13 minutes . The half-life of arcD mRNA, by contrast, was significantly shorter, suggesting that this mRNA segment may be destabilized by the processing cuts within arcD . Deletion of the putative intergenic stem-loop structures did not result in a dramatic loss of arc mRNA stability . Thus, the intergenic hairpin structures do not contribute importantly to the overall mRNA stability; they might act primarily as partial transcription terminators and locally protect the 3' ends from exonuclease action . The expression levels of the four Arc proteins correlated approximately with the relative abundance of the corresponding mRNA segments . In conclusion, mRNA processing and, presumably, partial termination of transcription contribute to differential gene expression within the arc operon.

J Inorg Biochem, 1992 Aug 15-Sep, 47(3-4), 175 - 81
Haem binding to ferritin and possible mechanisms of physiological iron uptake and release by ferritin; Moore GR et al.; Haem binding to horse spleen ferritin and Pseudomonas aeruginosa bacterioferritin has been studied by spectroscopic methods . A maximum of 16 haems per ferritin molecule, and 24 haems per bacterioferritin molecule, has been shown to bind . The influence of the bound haem on the rate of reductive iron release has been investigated . With a range of reductants and in the absence of haem the rate of release varied with the reductant, but in the presence of haem the rate was both independent of the reductant and faster than with any of the reductants alone . This indicates the rate-limiting step for iron release in the absence of haem was electron-transfer across the protein shell . Based on the results obtained with the in vitro assay system and from a consideration of data currently in the literature, plausible schemes for ferritin and bacterioferritin iron uptake and release are described.

J Steroid Biochem Mol Biol, 1992 Aug, 42(7), 721 - 7
Identification of an estrogen-binding protein in Pseudomonas aeruginosa; Rowland SS et al.; A constitutive estrogen-binding protein (EBP) has been identified in the cytosol of Pseudomonas aeruginosa, a Gram-negative bacterium . All 14 strains tested contained the EBP . Estradiol binding was rapid and maximal binding occurred by 90 min at 0 degrees C . Dissociation of estradiol from the binding protein occurred at a rate of 4.6 fmol/min with a t1/2 of 42 min . EBP binding was destroyed by protease treatment and at high temperature . Sodium molybdate had no effect on binding . The Kd determined by Scatchard analysis was 3.9 nM and the Bmax was 323 fmol/mg protein . The EBP sedimented at 8.9 S on sucrose density gradients . The presence of 0.4 M KCl increased estradiol binding 6-fold but did not cause a shift in the sedimentation value . Gel filtration of the native protein gave an estimated molecular weight of 215,000 and a Stokes radius of 50.2 A . Steroid binding specificity, in order of decreasing affinity, was estradiol, estrone, dihydrotestosterone, estriol, testosterone, progesterone and promegestone . Other steroid hormones tested did not compete for estradiol binding . Identification of an EBP in a bacterium allows a comparative analysis of other steroid-binding proteins in unicellular microorganisms.

Biochemistry, 1992 Aug 11, 31(31), 7152 - 4
Inhibition of human skin fibroblast collagenase, thermolysin, and Pseudomonas aeruginosa elastase by peptide hydroxamic acids; Grobelny D et al.; The hydroxamic acid HONHCOCH2CH(i-Bu)CO-L-Trp-NHMe, isomer 6A (GM 6001), inhibits human skin fibroblast collagenase with Ki of 0.4 nM using the synthetic thiol ester substrate Ac-Pro-Leu-Gly-SCH(i-Bu)CO-Leu-Gly-OEt at pH 6.5 . The other isomer, 6B, which has the opposite configuration at the CH2CH(i-Bu)CO alpha-carbon atom, has a Ki of 200 nM for this enzyme . GM 6001 is one of the most potent inhibitors of human skin fibroblast collagenase yet reported . GM 6001 has a Ki of 20 nM against thermolysin and Pseudomonas aeruginosa elastase . Isomer 6B has a Ki of 7 nM against thermolysin and 2 nM against the elastase . 6A and 6B are the most potent hydroxamate inhibitors reported for these bacterial enzymes . The pattern of inhibition for all three enzymes suggests that isomer 6A is the (R,S) compound, stereochemically analogous to the L,L-dipeptide, and isomer 6B is the (S,S) compound, analogous to the DL-dipeptide . The tolerance of the D configuration by thermolysin and the elastase allows these inhibitors to discriminate between the human and bacterial enzymes simply by inversion of configuration at the CH2CH(i-Bu)CO alpha-carbon atom . Substitution of the potential metal liganding groups carboxylate and hydrazide for the hydroxamate group yields much weaker inhibitors for all three enzymes.

J Mol Biol, 1992 Aug 5, 226(3), 651 - 60
Functional structures of the recA protein found by chimera analysis; Ogawa T et al.; We developed a novel genetic method for finding functional regions of a protein by the analysis of chimeras formed between homologous proteins . Sets of chimeric genes were made by intramolecular homologous recombination in a linearized plasmid DNA carrying both recA genes of Escherichia coli and Pseudomonas aeruginosa . A recBCsbcA strain of E . coli was used for isolation of plasmids carrying recombinants between these genes . Examination of properties of E . coli strains deleting the recA gene and carrying a plasmid with a chimeric gene shows that chimera formation at certain positions inactivates a RecA function . Frequently, all chimeras with a junction in a certain region of the protein inactivate a function . Rather than a direct effect of the presence of the junction at a particular position, mismatching of the regions both sides of the junction that are derived from the different species is responsible for the inactivation . For a chimeric protein to be functional, certain pairs of sequences in different regions of the protein must derive from the same parent . Four pairs of such sequences were found: two are involved in activities for genetic recombination and for resistance to ultraviolet light irradiation and the others in formation of active oligomers . Regions defined by these sequences are located in the looped regions of the protein . A pair of regions may co-operate to form a functional folded structure.

Infect Immun, 1992 Aug, 60(8), 3332 - 8
Characterization of antibody-mediated inhibition of Pseudomonas aeruginosa adhesion to epithelial cells; Sexton M et al.; An enzyme-linked immunosorbent assay system was developed and used to study adhesion of Pseudomonas aeruginosa to human epithelial cells and the abilities of specific antibodies to inhibit this process . Human buccal epithelial cells coated onto microtiter plates were incubated with P . aeruginosa suspensions, and adherent bacteria were detected by using anti-P . aeruginosa serum and a horseradish peroxidase-conjugated secondary antiserum . Adhesion, quantitated as an increase in A405, varied linearly with increasing numbers of bacterial CFU added per well in the range of 10(5) to 10(8) CFU per well . Adhesion of P . aeruginosa increased following trypsinization of buccal epithelial cells . Preincubation of bacteria with monoclonal antibodies directed against P . aeruginosa outer membrane protein H2 inhibited adhesion with all eight of the isolates tested . Preincubation of P . aeruginosa with sera from infected cystic fibrosis patients also resulted in inhibition of adhesion in the enzyme-linked immunosorbent assay system . This inhibitory activity was shown to be due to two factors: P . aeruginosa-specific immunoglobulin G and a non-immunoglobulin G serum component . These data support the hypothesis that bacterial components other than pili are involved in adhesion and suggest that anti-P . aeruginosa antibodies may be of use in preventing adhesion and subsequent colonization with P . aeruginosa.

Infect Immun, 1992 Aug, 60(8), 3162 - 8
Induction of tumor necrosis factor (TNF) and interleukin-1 (IL-1) by Pseudomonas aeruginosa and exotoxin A-induced suppression of lymphoproliferation and TNF, lymphotoxin, gamma interferon, and IL-1 production in human leukocytes; Staugas RE et al.; Pseudomonas aeruginosa is a dominant pathogen in infection in cystic fibrosis . This bacterium is thought to play a major role in the chronic bronchial infection-induced pathophysiology . Our data showed that whole formalin-fixed heat-killed P . aeruginosa was mitogenic for human lymphocytes and induced production of substantial amounts of tumor necrosis factor alpha (TNF) in peripheral blood mononuclear leukocytes in cultures . Significant amounts of TNF were produced at 10(3) bacteria per 2 x 10(5) mononuclear leukocytes . Treatment of P . aeruginosa with polymixin B did not affect its ability to stimulate TNF production, suggesting that bacterial lipopolysaccharide is not involved . P . aeruginosa, however, did not stimulate production of the T-cell lymphokine lymphotoxin (TNF beta) . Exotoxin A, considered to be an important virulence factor produced by P . aeruginosa, did not stimulate either lymphoproliferation or production of TNF . In fact, this toxin, at nontoxic concentrations, was found to depress lymphoproliferation induced by phytohemagglutinin and Staphylococcus aureus and decreased production of TNF, lymphotoxin, and gamma interferon in either lymphocytes or macrophages . This toxin similarly inhibited the production of interleukin-1 beta (IL-1 beta) and IL-1 alpha, but for the inhibition of the latter, 25-fold-less toxin was required than for inhibition of the former . Inhibition of production of TNF was as sensitive as the IL-1 alpha to exotoxin A . The effects of exotoxin A on lymphoproliferation and cytokine production could be neutralized by the addition of anti-exotoxin A antibodies . These results suggest that two mechanisms by which P . aeruginosa could contribute to the chronic bronchial infection-induced pathophysiology are the nonspecific stimulation of TNF and IL-1 and the release of exotoxin A, a toxin which depresses immune responses.

Infect Immun, 1992 Aug, 60(8), 3150 - 5
Induction of inflammatory mediator release (serotonin and 12-hydroxyeicosatetraenoic acid) from human platelets by Pseudomonas aeruginosa glycolipid; Konig B et al.; Purified glycolipid from Pseudomonas aeruginosa induced the generation of significant amounts of 12-hydroxyeicosatetraenoic acid (12-HETE) and serotonin release from human platelets . The release of serotonin was first observed 2 min after addition of the glycolipid and increased with time . Significant serotonin release was obtained at glycolipid concentrations above 5 micrograms/ml and increased dose-dependently up to 100% at glycolipid concentrations above 40 micrograms/ml . Glycolipid induced 12-HETE in a time- and dose-dependent manner . 12-HETE formation was first measured after 10 min of incubation and increased with time . Optimal 12-HETE formation was obtained at a glycolipid concentration of 50 micrograms/ml; higher concentrations of glycolipid led to a decrease in 12-HETE formation, indicating a cytotoxic effect . Stimulation of platelets with glycolipid (12-HETE formation and serotonin release) was accompanied by calcium influx, translocation of protein kinase C, activation of guanylylimidodiphosphate binding, and increased GTPase activity in platelet membranes within the same concentration range.

Arch Biochem Biophys, 1992 Aug 1, 296(2), 505 - 13
Purification, molecular cloning, and expression of lipase from Pseudomonas aeruginosa; Chihara-Siomi M et al.; An extracellular lipase secreted by Pseudomonas aeruginosa TE3285 was purified . A genomic library of this strain was constructed in lambda EMBL3, and a DNA fragment 2.7 kb long containing the lipase gene, lipA, was isolated with an oligonucleotide probe synthesized on the basis of the partial amino acid sequence of a purified preparation of the enzyme . Nucleotide sequence analysis showed an open reading frame of 933 bases, and the deduced amino acid sequence agreed well with the molecular mass and partial amino acid sequences of mature lipase . The results of alignment of the amino acid sequences of five lipases from Pseudomonas species considered together with the published crystal structure studied with human pancreatic lipase showed that Ser82, His251, and Asp209 were catalytic residues and that a surface loop from residues 172 to 204 was responsible for the substrate specificity . About 50 bases downstream of lipA, there was another gene, lipB . The sequence of lipB was highly homologous to that of putative modulators of the production of active lipases in other Pseudomonas species . Expression plasmids encoding lipA followed by the complete or incomplete lipB gene downstream of the lac promoter of pUC18 were constructed . lipA was expressed in Escherichia coli 1100 only in the presence of the complete lipB gene.

J Bacteriol, 1992 Aug, 174(15), 5156 - 60
Activation defects caused by mutations in Escherichia coli rpoA are promoter specific; Gussin GN et al.; Escherichia coli RNA polymerases containing mutated alpha subunits were tested for their ability to respond to three different positive regulators (activators) in vitro . The two alpha (rpoA) mutants, alpha-256 and alpha-235, have deletions of the C-terminal 73 and 94 amino acids, respectively . In runoff transcription assays catalyzed by reconstituted holoenzyme, the effects of the mutations on each of three promoters tested were different: activation of the lambda pRM promoter by cI protein (repressor) was nearly normal, activation of the lambda pRE promoter by cII protein was reduced approximately fivefold, and direct activation of the trpPB promoter of Pseudomonas aeruginosa was completely inhibited . We also found that the reconstituted mutant enzyme was defective in recognition of trpPI in the absence of activator . The differential responses of the three promoters to their activators in the presence of the mutant enzymes indicate that the location of an activator-binding site does not by itself determine the region of RNA polymerase with which the activator interacts.

J Bacteriol, 1992 Aug, 174(15), 5149 - 51
Phosphate taxis in Pseudomonas aeruginosa; Kato J et al.; Pseudomonas aeruginosa was shown to be attracted to phosphate . The chemotactic response was induced by phosphate starvation . The specificity of chemoreceptors for phosphate was high so that no other tested phosphorus compounds elicited a chemotactic response as strong as that elicited by phosphate . Competition experiments showed that the chemoreceptors for phosphate appeared to be different from those for the common amino acids . Mutants constitutive for alkaline phosphatase showed the chemotactic response to phosphate regardless of whether the cells were starved for phosphate.

J Gen Microbiol, 1992 Aug, 138 ( Pt 8), 1665 - 70
Heterologous expression of an alginate lyase gene in mucoid and non-mucoid strains of Pseudomonas aeruginosa; Gacesa P et al.; A 1.95 kb DNA fragment containing the aly gene from Klebsiella pneumoniae, which encodes an alginate lyase, has been ligated into the broad-host-range vector pLAFR3 . Transfer of the resultant recombinant plasmid, pALY8, into mucoid and non-mucoid strains of Pseudomonas aeruginosa resulted in expression of the alginate lyase . The heterologously expressed alginate lyase, which had the same isoelectric point and substrate specificity as the native enzyme, altered the morphology of mucoid strains . Analysis of the extracellular material from mucoid strains revealed that lyase expression reduced the M(r) and overall yield of alginate produced . The mature form of the recombinant enzyme was the same as that produced extracellularly by Klebsiella pneumoniae; however, most of the alginate lyase was retained intracellularly by P . aeruginosa.

J Oral Pathol Med, 1992 Aug, 21(7), 299 - 304
The role of saliva in aggregation and adherence of Pseudomonas aeruginosa in patients with cystic fibrosis; Tumber-Saini SK et al.; The aggregation and adherence activity of P . aeruginosa, mediated by whole saliva from cystic fibrosis (CF) patients and non-CF subjects, was investigated . CF saliva-mediated aggregation of P . aeruginosa was stronger than the activity of non-CF saliva . Likewise, P . aeruginosa adherence to buccal epithelial cells (BEC) of CF patients was stronger than to BEC of non-CF subjects . Adherence of non-mucoid P . aeruginosa to BEC of CF patients was increased by saliva, whereas the mucoid variant was not . CF patients colonized with P . aeruginosa showed higher adherence of the non-mucoid variant than non-colonized CF patients . CF patients with high saliva-mediated adherence of non-mucoid P . aeruginosa also had high salivary aggregation activity . Increased CF saliva-mediated aggregation activity may be linked to the increased non-mucoid P . aeruginosa adherence to BEC of CF patients.

Jpn J Antibiot, 1992 Aug, 45(8), 958 - 64
{Combined effects of arbekacin with other antibiotics against methicillin-resistant Staphylococcus aureus . II . The combined effect of arbekacin with imipenem or cefminox}; Deguchi K et al.; Combined antibacterial effects of imipenem (IPM)+arbekacin (ABK) and cefminox (CMNX)+ABK against methicillin-resistant Staphylococcus aureus (MRSA) were examined and the obtained results are summarized below . 1 . Either combination, IPM+ABK or CMNX+ABK, showed a strong antibacterial effect against MRSA when blood concentration of ABK were sustained at MIC as could be expected in clinical situations . While at sub MICs of ABK the antibacterial effect of these combination was slightly less than those of the previously reported combinations of ABK and other antibiotics . 2 . Antibacterial effects of the combinations against MRSA were strongly dependent on the concentration of ABK and less dependent on the concentration of IPM or CMNX . As were observed in the previously tested combinations of ABK with other antibiotics, the antibacterial effect of the combination appeared to be highly dependent on the antibacterial activity and the concentration of ABK . 3 . As IPM has potent antibacterial activities against Gram-negative bacteria (GNB) including Pseudomonas aeruginosa while CMNX has potent antibacterial activities against GNB except P . aeruginosa, it is likely that the combinations of IPM+ABK or CMNX+ABK are useful for treatment of infections with MRSA together with GNB.

Jpn J Antibiot, 1992 Aug, 45(8), 949 - 57
{Combined effects of arbekacin with other antibiotics against methicillin-resistant Staphylococcus aureus . I . The combined effect of arbekacin with fosfomycin or clavulanic acid/ticarcillin}; Deguchi K et al.; As arbekacin (ABK) has a highly potent antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), its combined effects with fosfomycin (FOM) and clavulanic acid/ticarcillin (CVA/TIPC) against MRSA were examined . The obtained results are summarized as follows . 1 . Against MRSA either combination, FOM+ABK or CVA/TIPC+ABK showed a strong antibacterial effect at the MIC or the sub MIC of ABK in the blood expected from clinical observations . The MIC of ABK by the combination use seemed to be equivalent to the MBC value . 2 . Effective concentrations of antibiotics in these combinations appeared to be strongly dependent on the effective concentration of ABK and less dependent on that of FOM or CVA/TIPC . Therefore, the antibacterial activity of a combination seems to mostly depend on the antibacterial activity and the concentration of ABK . 3 . As FOM and CVA/TIPC have antibacterial activities against Pseudomonas aeruginosa, combinations of ABK with these antibiotics are likely to be effective against double infection with P . aeruginosa in MRSA infected patients.

Eur J Clin Microbiol Infect Dis, 1992 Aug, 11(8), 715 - 21
Quantitative assay for testing susceptibility of HIV isolates to zidovudine and sCD4 (178)-PE40; Verhoef J et al.; A quantitative coculture assay is described for determining susceptibility of HIV-1 isolates to zidovudine and sCD4 (178)-PE40 (a 60 kDa hybrid protein consisting of the gp120 binding region of CD4 linked to the translocation and ADP-ribosylation regions of Pseudomonas aeruginosa exotoxin) . The assay was relatively simple to perform and gave highly reproducible results often within three to five days . IC50 values of zidovudine for HIV-1 strains isolated from two AIDS patients and an asymptomatic seropositive individual were in the range 0.001-0.002 mumol . Isolates obtained after six months of zidovudine treatment had zidovudine IC50 values of 0.01-0.5 mumol . All isolates were equally sensitive to sCD4 (178)-PE40 (IC50 1-5 micrograms/ml) . HIV-1 activation in the chronically infected cell line U-1 was inhibited by sCD4 (178)-PE40 but not by zidovudine.

Curr Eye Res, 1992 Aug, 11(8), 727 - 38
Systemic and topical protection studies using Pseudomonas aeruginosa flagella in an ocular model of infection; Rudner XL et al.; Purified flagella from P . aeruginosa ATCC 19660 were used for active, passive, or topical immunization prior to corneal challenge with strain 19660 . At 30 days post-infection, a significant number of mice actively or passively immunized with flagella and infected with the homologous bacterial strain were protected from ocular disease when compared to control animals . In topical immunization studies, premixing of 19660 flagella with the bacterial inoculum prior to ocular challenge with strain 19660, provided results similar to those of the active or passive immunization studies . A reduced lipopolysaccharide (LPS:1 E.U./mg) flagella preparation was also produced and used similarly . Again, significant protection was achieved in mice immunized by flagella regardless of the immunization route . An in vitro adherence assay also was performed to examine quantitatively the effect of exogenously applied flagella, or an antiflagella monoclonal antibody (MAb) on bacterial adhesion . Premixing of the bacterial inoculum with flagella or the MAb prior to applying it topically to corneas in organ culture all significantly inhibited bacterial binding . These results strongly suggest that significant ocular protection is achieved with either active or passive immunization, or premixing of the bacterial inoculum with flagella from strain 19660 prior to ocular challenge with the homologous bacterial strain . They also indicate that topical application of flagella or antiflagella MAb provide protection against ocular disease by decreasing bacterial adhesion to cornea.

Antimicrob Agents Chemother, 1992 Aug, 36(8), 1601 - 5
Quinolone accumulation in Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus; McCaffrey C et al.; The accumulation of quinolones by Escherichia coli JF568, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 29213 was measured by a modified fluorometric assay (J . S . Chapman and N . H . Georgopapadakou, Antimicrob . Agents Chemother . 33:27-29, 1989) . The quinolones examined were fleroxacin, pefloxacin, norfloxacin, difloxacin, A56620, ciprofloxacin, ofloxacin, and Ro 09-1168 . In all three organisms, uptake was complete in less than 5 min and was proportional to extracellular quinolone concentrations between 2 and 50 micrograms/ml, which is consistent with simple diffusion . Washing cells with quinolone-free buffer decreased accumulation by up to 70% in E . coli and P . aeruginosa but not in S . aureus . Similarly, incubation with the uncouplers 2,4-dinitrophenol and carbonyl cyanide m-chlorophenylhydrazone increased accumulation up to fourfold in E . coli and P . aeruginosa, though not in S . aureus, suggesting endogenous, energy-dependent efflux . High quinolone hydrophobicity was generally associated with decreased accumulation in E . coli and P . aeruginosa (except in the case of pefloxacin) but was associated with increased accumulation in S . aureus (except in the case of difloxacin) . Ciprofloxacin had the highest accumulation in E . coli and P . aeruginosa, while pefloxacin had the highest accumulation in S . aureus.

Mol Microbiol, 1992 Aug, 6(16), 2319 - 26
Polyphosphate-selective porin OprO of Pseudomonas aeruginosa: expression, purification and sequence; Siehnel RJ et al.; The oprO gene of Pseudomonas aeruginosa codes for a polyphosphate-specific porin and terminates 458 bp upstream of the start codon for the phosphate-specific porin OprP . OprO was found to be expressed only under phosphate-starvation conditions in both wild-type and oprP::Tn501 mutant P . aeruginosa strains . However, unlike the rest of the genes of the Pho regulon, including oprP, expression of oprO required cells to be in the stationary growth phase in addition to phosphate starvation . Wild-type P . aeruginosa cells were grown in fermentor culture under these conditions and fractionated by selective solubilization in octylpolyoxyethylene detergent solution . Solubilized OprO was separated from OprP by application to a Mono Q FPLC column and elution with a salt gradient and shown to be functionally identical to cloned OprO produced in Escherichia coli . DNA sequencing of oprO showed the gene product to be highly homologous to OprP, with 76% identity and 16% conserved substitutions . Most genes of the Pho regulon possess a modified -35 region called the Pho box . Two such elements, separated by 4 bp were found in oprO . DNA sequencing also revealed a second Pho box in the oprP gene with the same spacing.

Rinsho Ketsueki, 1992 Aug, 33(8), 1041 - 5
{Malignant lymphoma developing from the wall of chronic empyema following artificial pneumothorax}; Tachibana J et al.; A 60-year-old man who had had chronic empyema following an artificial pneumothorax for pulmonary tuberculosis when he was 26 years old developed malignant lymphoma of the chest wall . The patient was admitted because of right pyothorax as a result of pseudomonas aeruginosa infection and underwent right thoracotomy . During lavage of the right thoracic cavity a tumor was found arising from the empyematic wall . Pathologic examination revealed that it was malignant lymphoma (diffuse large, immunoblastic, B cell type) . Treatment with VEAP-Bleomycin elicited a good response . Seven months after chemotherapy, the patient underwent thoracoplasty in addition to packing the cavity with the latissimus dorsi and the greater omentum . Following this, the patient received chemotherapy once a month for one and a half years, after which he was kept under close observation without treatment . Complete remission has now lasted for 49 months since the initial treatment . This is the first reported lymphoma case with closure of the empyematic wall and is remarkable since this patient has remained in complete remission for the last two years without any treatment.

J Chemother, 1992 Aug, 4(4), 225 - 7
Subcutaneous nodules caused by Pseudomonas aeruginosa: healing without incision and drainage; Korten V et al.; In a patient with multiple myeloma, numerous indurated, subcutaneous nodules and pyomyositis due to Pseudomonas aeruginosa were noted . These lesions resolved with ciprofloxacin plus ceftazidime therapy without surgical incision and drainage . Despite another course of cancer chemotherapy after total disappearance, there were no recurrences at the end of 3 months . Quinolones initially combined with other antipseudomonal beta-lactam agents may be the drugs of choice in the management of patients with subcutaneous nodules caused by P . aeruginosa.

Kansenshogaku Zasshi, 1992 Aug, 66(8), 1097 - 104
{Long-term chemotherapy using erythromycin (EM) for chronic lower airway infection: effectiveness of clarithromycin in EM ineffective cases--the fourth report}; Mikasa K et al.; The effectiveness of long-term chemotherapy using Erythromycin (EM) for chronic lower airway infection has been practically proved . However, there still exist some ineffective cases, or cases in which the clinical effect was scarcely seen . In the present study was administered Clarithromycin (CAM) to such cases and found that CAM was effective in alleviating symptoms in some of them . The results were presented along with clinical findings and other basic studies . The subjects were 4 cases in which EM was either ineffective or low in its clinical effect . The subjects consisted of 1 case of DPB and 3 cases of bronchiectasis . EM was clinically ineffective in 2 cases and slightly effective in the two others . The pathogen was Pseudomonas aeruginosa in all cases . The dosage of EM was 200-1200 mg/day . The period of administration ranged from 2 years to 6 years 9 months . CAM was given orally after meals at a dose of either 200 or 400 mg/day . Chemotherapy had continued for 3-8 months at the time of final observation (Feb . 1992) . Clinical effectiveness was evaluated on the basis of sputum volume and PaO2 examination, as well as evaluation by the patients themselves . As a result, in all 4 cases, reduction in sputum volume and improvement of PaO2 were observed . All subjects evaluated CAM therapy as being more effective than EM therapy . Moreover, it was found that CAM inhibited both the elastase and leucocidin produced in one of the ineffective cases by P . aeruginosa, whereas EM didnt.(ABSTRACT TRUNCATED AT 250 WORDS)

Chest, 1992 Aug, 102(2), 647 - 9
Systemic hypersensitivity vasculitis associated with bronchiectasis; Tanaka E et al.; Systemic hypersensitivity vasculitis developed in a 53-year-old man during acute exacerbation of bronchiectasis infected with Pseudomonas aeruginosa . High grade fever, mononeuropathy multiplex, cutaneous vasculitis, and biopsy specimen-proved mesangioproliferative glomerulonephritis with crescent formation and leukocytoclastic vasculitis associated with circulating immune complex occurred . Corticosteroid and cyclophosphamide therapy was effective for vasculitis and bronchiectasis.

Am J Clin Pathol, 1992 Aug, 98(2), 222 - 6
Systemic polyclonal B-immunoblastic proliferation with marked peripheral blood and bone marrow plasmacytosis; Poje EJ et al.; The clinical and pathologic features of a case of acute systemic polyclonal B-immunoblastic proliferation characterized by pronounced peripheral blood and bone marrow plasmacytosis and infiltration of the hepatic portal areas by immunoblasts, plasma cells, and lymphocytes are reported . Clinical and laboratory findings during the acute phase and long-term follow-up support the diagnosis of a benign process, possibly related to Pseudomonas aeruginosa septicemia . The patient experienced a dramatic clinical recovery on administration of high-dose intravenous corticosteroids . Pathologists should be aware of this entity so as not to confuse it with non-Hodgkin's lymphoma or a form of plasma cell dyscrasia.

Pediatr Res, 1992 Aug, 32(2), 175 - 8
Genotype/phenotype association in cystic fibrosis: analyses of the delta F508, R553X, and 3905insT mutations; Liechti-Gallati S et al.; A striking clinical phenomenon of cystic fibrosis is the heterogeneous disease expression . It must therefore be assumed that the nature of the mutations associated with cystic fibrosis might partly determine the phenotypic manifestations . The relation between the cystic fibrosis mutations delta F508, R553X, and 3905insT and clinical parameters such as sweat test electrolytes, age at chronic Pseudomonas aeruginosa colonization, Chrispin-Norman x-ray scores, and relative underweight have been investigated in 45 patients homozygous for delta F508 (delta F2), in 12 compound heterozygotes for delta F508/R553X (delta F1/RX1), in three R553X homozygotes (RX2), and in 13 patients compound heterozygous for delta F508/3905insT (delta F16) . We have found significant differences between the genetically defined subgroups concerning the mean age at onset and the cumulative incidence of chronic P . aeruginosa colonization and Chrispin-Norman x-ray scores . The significant results as well as some trends regarding the relative underweight demonstrate a milder clinical course in R553X heterozygotes and more severe disease in the delta F16 group compared to delta F508 homozygotes . The three patients homozygous for R553X presented with a two-stage course showing mild progression before P . aeruginosa infection and as severe a course as the delta F16 patients after P . aeruginosa colonization at the age of 12 y . The findings presented here indicate that specific mutations can influence the severity and progression of the disease, implicating the importance of mutation and haplotype analyses . However, wide variations within the genetically homogeneous subgroups illustrate that other determinants of the clinical status do exist.

Crit Care Med, 1992 Aug, 20(8), 1127 - 33
Effects of granulocyte colony-stimulating factor in modifying mortality from Pseudomonas aeruginosa pneumonia after hemorrhage; Abraham E et al.; BACKGROUND AND METHODS: Alterations in immune function occurring after hemorrhage and trauma may contribute to the high occurrence rates of nosocomial pneumonia, multiorgan system failure, morbidity, and mortality in this setting . Therapy with granulocyte colony-stimulating factor (G-CSF) can increase neutrophil numbers and function, and enhance resistance to infection in experimental and clinical settings associated with abnormal immune function . To investigate whether treatment with G-CSF could increase resistance to pneumonia after hemorrhage, we bled mice 30% of the blood volume and treated them with various doses of G-CSF, starting either immediately or 2 days after hemorrhage . Pseudomonas aeruginosa pneumonia was induced by the intratracheal instillation of 2 x 10(7) colony-forming units of P . aeruginosa 4 days after blood loss, and mortality was assessed over the next 7 days . RESULTS: Treatment of mice with 100 or 500 micrograms/kg/day G-CSF, but not with 50 micrograms/kg/day, resulted in significant increases in the numbers of circulating polymorphonuclear cells . Platelet counts significantly decreased in mice given 500 micrograms/kg/day G-CSF . Mice given 100 micrograms/kg/day G-CSF starting 2 days after blood loss had improved outcome compared with vehicle-treated controls (38% survival rate in the G-CSF treated group vs . 8% in controls, p less than .05) . There also was a trend toward an improved survival rate in mice treated with 50 micrograms/kg/day G-CSF for 4 days after hemorrhage (46% survival rate in G-CSF treated vs . 17% in controls) . CONCLUSIONS: G-CSF prophylactically administered after hemorrhage can improve survival from pneumonia due to P . aeruginosa . However, the protection afforded by G-CSF was highly dependent on the dosing schedule used.

J Bacteriol, 1992 Aug, 174(15), 4977 - 85
Analysis of the Pseudomonas aeruginosa major outer membrane protein OprF by use of truncated OprF derivatives and monoclonal antibodies; Finnen RL et al.; TnphoA mutagenesis of the cloned oprF gene was utilized to generate 16 classes of fusions encoding differing lengths of the amino terminus of OprF fused to either alkaline phosphatase or to peptide tags of 1 to 20 amino acids, depending on the orientation and reading frame into which TnphoA was inserted . Representatives of each of the 16 classes were sequenced to determine the precise fusion joint . Four of these 16 representatives which produced in-frame fusions to alkaline phosphatase and another 8 with fusion joints in the amino-terminal half of OprF failed to react with a panel of 10 specific monoclonal antibodies . In contrast, OprF derivatives with predicted fusion joints at amino acids 180, 204, 289, and 299 reacted with one to five of the monoclonal antibodies . Four other immunoreactive OprF derivatives were created by subcloning and encoded amino acids 1 to 187, 188 to 326, 1 to 273 and 1 to 170 plus 301 to 326 . On the basis of reactivity with the TnphoA-truncated derivatives and subclones of oprF, the epitopes for all 10 monoclonal antibodies were localized, in part, to specific regions of OprF . Nnie of the 10 monoclonal antibodies, 8 of which recognize surface-exposed epitopes, mapped within the carboxy-terminal region of OprF that is homologous to the Escherichia coli outer membrane protein OmpA . Thus, we concluded that parts of the carboxy terminus of OprF are exposed on the external face of the outer membrane . In addition, a clone containing only the first two cysteine residues of OprF demonstrated reactivity with monoclonal antibodies MA4-4 and MA7-8 that was destroyed by 2-mercaptoethanol treatment, as was reactivity with intact OprF . Thus, we conclude that this first pair of cysteines at residues 176 and 185 of mature OprF form a disulfide bond.

Biotechnology (N Y), 1992 Aug, 10(8), 910 - 2
Antibody production in silkworm cells and silkworm larvae infected with a dual recombinant Bombyx mori nuclear polyhedrosis virus; Reis U et al.; We have examined the efficiency of coexpression of two heterologous genes from a recombinant Bombyx mori nuclear polyhedrosis virus for the production of antibodies in silkworm larvae . The cDNAs encoding the light and the heavy chains of a murine immunoglobulin, directed against lipoprotein I of Pseudomonas aeruginosa, were brought under the control of two separate copies of the viral polyhedrin promotor . Infection of silkworm cells with the recombinant baculovirus yielded a maximum of 6.4 micrograms/ml IgG2A in the culture supernatant 72 hours post infection, while 800 micrograms/ml IgG2A was found in the hemolymph of infected fifth instar silkworm larvae seven days after infection with the same construct . The recombinant antibody exhibited a similar antigen specificity and avidity to that of the monoclonal antibody derived from ascites fluid.

Antimicrob Agents Chemother, 1992 Aug, 36(8), 1791 - 3
Nucleotide sequence of the protein D2 gene of Pseudomonas aeruginosa; Yoneyama H et al.; Protein D2 of the outer membrane of Pseudomonas aeruginosa was shown to form the imipenem-permeable pore . We cloned and sequenced the protein D2 gene . The protein D2 gene encodes a polypeptide with 443 amino acids consisting of 23 and 420 amino acid residues for the signal peptide and mature polypeptide (M(r), 46,010), respectively . Protein D2 contains the highest molar ratio of glycine and no cysteine . The polar amino acids are scattered throughout the sequence.

J Biochem (Tokyo), 1992 Aug, 112(2), 290 - 8
A novel terminal oxidase, cytochrome baa3 purified from aerobically grown Pseudomonas aeruginosa: it shows a clear difference between resting state and pulsed state; Fujiwara T et al.; A novel type of cytochrome c oxidase was purified to homogeneity from Pseudomonas aeruginosa which was grown aerobically . The purified oxidase contained two molecules of heme a, two atoms of copper, and one molecule of protoheme per molecule . One of the two heme a molecules in the oxidase reacted with carbon monoxide, so that the enzyme was of baa3-type . The oxidase molecule was composed of three subunits with molecular weights of 38,000, 57,000, and 82,000 . Although the oxidase oxidized ferrocytochrome c-550 obtained from the bacterial cells grown aerobically, the oxidizing activity was not high . The "resting form" and the "pulsed form" of the oxidase were observed clearly with this enzyme, and the transition from the resting form to the pulsed form was accompanied by a distinct change of the enzymatic activity . The difference in the kinetics of the catalytic reactions between the two forms is discussed.

J Bacteriol, 1992 Aug, 174(16), 5196 - 203
Reevaluation, using intact cells, of the exclusion limit and role of porin OprF in Pseudomonas aeruginosa outer membrane permeability; Bellido F et al.; Earlier studies that used model membrane reconstitution methods have come to different conclusions regarding the exclusion limit of the outer membrane of Pseudomonas aeruginosa and whether OprF is the major channel-forming protein in the outer membrane . In this study, a 6.2-kbp SalI fragment, encoding only two cytoplasmic enzymes, alpha-galactosidase and sucrose hydrolase, and the inner membrane raffinose permease, was cloned behind the m-toluate-inducible tol promoter of vector pNM185 to create plasmid pFB71 . P . aeruginosa strains harboring pFB71, when grown with inducer, produced both enzymes encoded by the insert and had acquired the ability to grow on the disaccharide melibiose and the trisaccharide raffinose . The rate of growth was dependent on the concentration and size of the saccharide and was decreased three- to fivefold by the absence of OprF, as examined by measuring the growth on melibiose and raffinose of an isogenic OprF-deficient omega insertion derivative, H636(pFB71) . At high concentrations, di-, tri-, and tetrasaccharides could pass across the outer membrane to plasmolyze P . aeruginosa, as measured by light scattering and confirmed by electron microscopy . The initial rate kinetics of light-scattering changes were dependent on the size of the saccharide being used . Furthermore, the rates of change in light scattering due to raffinose and stachyose uptake across the outer membrane for strain H636 were fivefold or more lower than for its OprF-sufficient parent H103 . These data are consistent with model membrane studies showing that OprF is the most predominant porin for compounds larger than disaccharides in P . aeruginosa and suggest that the exclusion limit for this porin and the outer membrane is greater than the size of a tetrasaccharide . In addition, these data confirmed the existence of other porins with a predominant function in monosaccharide uptake and a more minor function in the uptake of larger saccharides.

Biochem Biophys Res Commun, 1992 Jul 31, 186(2), 645 - 51
Porin of Pseudomonas aeruginosa forms low conductance ion channel in planar lipid bilayers; Obara M et al.; Protein E1, a porin of the outer membrane of Pseudomonas aeruginosa, was reconstituted into planar lipid bilayers . Single channel conductance of the protein appeared to be 230 pS (pico siemens) in 1 M KCl-10 mM Hepes, pH7.2 . This value is approximately 5 times lower than the conductance of the OmpF channel of Escherichia coli . Conductance increased linearly as the membrane potential was raised from -200 mV to +200 mV, and was nearly proportional to the KCl concentration . These results show that protein E1 is probably a genuine porin in the P . aeruginosa outer membrane supporting the earlier conclusion that protein E1 forms a small channel.

FEBS Lett, 1992 Jul 20, 306(2-3), 119 - 24
Crystal structure of Pseudomonas aeruginosa apo-azurin at 1.85 A resolution; Nar H et al.; The 3D structure of apo-azurin from Pseudomonas aeruginosa has been determined at 1.85 A resolution . The crystal structure is composed of two different molecular forms of apo-azurin arranged as hetero-dimers in the tetramer of the asymmetric unit . Form 1 closely resembles the holo-protein lacking copper . Form 2 shows differences in the metal binding site region induced by the incorporation of a solvent molecule into this site . The positions of the copper ligands His46 and His117 are shifted by 0.6 A and 1.6 A . The His117 side chain adopts a position at the surface of the protein, thereby facilitating access to the copper site . The presence of two different molecular forms of apo-azurin in the crystal lattice may reflect an equilibrium between the two forms in solution . 1H-NMR spectra of apo-azurin recorded as a function of pH show that at high pH the line broadening of His35, His46 and His117 resonances is consistent with an interconversion between forms 1 and 2 . At low pH, no broadening is observed . This may indicate that here the interconversion is fast on the NMR timescale.

FEBS Lett, 1992 Jul 13, 306(1), 5 - 8
Separation of gate- and channel-forming domains in the pore-forming protein of the outer membrane of Pseudomonas aeruginosa; Yoshihara E et al.; The domains of the pore-forming protein responsible for the gate and channel formations were separated and identified in the outer membrane of Pseudomonas aeruginosa . The proteolytic cleavage of the 46K channel protein, protein D2, yielded two major domains with apparent M(r) of 27K and 19K . We identified the 27K polypeptide to be the channel-forming domain by an in vitro permeability assay . The channel size of purified 27K domain was indistinguishable from that of native protein D2 . Degradation of the 19K domain into small subfragments increases the channel activity about ten times suggesting that the 19K polypeptide forms the gate or cap.

FEBS Lett, 1992 Jul 13, 306(1), 41 - 5
Properties of Pseudomonas aeruginosa exotoxin A ionic channel incorporated in planar lipid bilayers; Gambale F et al.; Acidic conditions induce the incorporation of Pseudomonas aeruginosa exotoxin A into phospholipid planar bilayers and the formation of pores permeable to electrolytes . Channel openings occur as single events, although they may occasionally cluster in bursts . In 100 mM KCl, the elementary single channel current amplitude is 3.1 pA (at a transmembrane voltage of 100 mV), the mean open time is 1.3 ms, while bursts may last for several seconds . Noise analysis gave results identical to single channel analysis . Voltage pulse protocols and continuous cycling voltage ramps showed that the toxin channel is voltage dependent, having a higher probability of being open at positive voltages.

Appl Microbiol Biotechnol, 1992 Jul, 37(4), 446 - 50
Scale-up and optimization of culture conditions of a human heterohybridoma producing serotype-specific antibodies to Pseudomonas aeruginosa; Schurch U et al.; Three different stirred bioreactors of 0.5 to 121 volume were used to scale up the production of a human monoclonal antibody . Inoculation density and stirrer speed were evaluated in batch cultures, whereas dilution rate and pH were optimized in chemostat cultures with respect to high specific antibody production rate and high antibody yield per time and reactor volume . The cell line used for the experiments was a heterohybridoma, producing immunoglobulin M (IgM) against lipopolysaccharide of Pseudomonas aeruginosa . Cells were cultured in spinner flasks of 500 ml liquid volume for adaptation to stirred culture conditions . Subsequently cells were transferred to the 1.5-l KLF 2000 bioreactor and to the 12-l NLF 22 bioreactor for pilot-scale cultures . Chemostat experiments were done in the 1.5-l KLF bioreactor . Cell density, viability, glucose and lactate and antibody concentration were measured during culture experiments . In batch cultures in all three stirred bioreactors, comparable maximal cell densities and specific growth rates were achieved . Chemostat experiments showed that at a pH of 6.9 and a dilution rate of 0.57 per day the specific antibody production rate was threefold higher than similar experiments done at pH 7.2 with a dilution rate of 0.36 per day . By optimizing pH and dilution rate in chemostat cultures the daily yield of human IgM increased nearly threefold from 6 to 16 mg/day and per litre of reactor volume . The yield per litre of medium increased twofold.

J Med Chem, 1992 Jul 10, 35(14), 2631 - 42
Synthesis and structure-activity relationships of cephalosporins with C-3' catechol-containing residues; Arnould JC et al.; Cephalosporins with new catechol substituents at C-3' have been synthesized, including novel compounds with C-3' carbon-carbon bonds . Many of these compounds have high potency against Gram-negative bacteria, in particular against resistant strains like Pseudomonas aeruginosa . Structure-activity relationships are discussed in terms of their dependence on the pKa of the C-3' catechol and also in terms of steric and conformational factors of the C-3' substituent . The best overall properties were found in compounds with a bulky and/or conformationally restricted acidic C-3' catechol.

J Immunol Methods, 1992 Jul 6, 151(1-2), 157 - 64
Analyses of affinity distributions within polyclonal populations of antigen-specific antibodies . Evaluation of their accuracy in population detection using monoclonal antibodies; Bruderer U et al.; The potential of an ELISA based detection of affinity distributions within polyclonal populations of antigen-specific serum antibodies was assessed by analyzing defined probes composed of monoclonal antibodies (MAb) . In a competitive binding ELISA in which the concentration of antigen in the liquid phase and the solid phase was varied, we analyzed mixtures containing defined percentage compositions of MAb exhibiting apparent affinity constants (aK) between 3 x 10(6) and 2 x 10(9) M-1 for Pseudomonas aeruginosa exotoxin A . Our results indicate that the detectability of antibody populations depends on the antigen concentrations in the solid phase and on the affinity distribution of the probe to be analyzed . In wells coated with high antigen concentrations, antibody titers reflected antibody concentrations, whereas at low antigen concentrations antibody titers primarily reflect antibody affinities . Independent of their affinities, subpopulations less than 10% could not be detected . Low affinity antibodies were preferentially underestimated . The degree of distortion depended on the composition of the probe to be analyzed . In general, the higher the absolute and the relative affinity of a population, the stronger was its capacity to interfere with the detection of other populations . As a consequence, the heterogeneity of affinity distributions in polyclonal samples may be substantially underestimated . The experiments reported provide guidelines for an optimal design and an adequate interpretation of ELISA based qualitative analyses of polyclonal antibody samples.

J Biol Chem, 1992 Jul 5, 267(19), 13585 - 92
Characterization of the mmsAB operon of Pseudomonas aeruginosa PAO encoding methylmalonate-semialdehyde dehydrogenase and 3-hydroxyisobutyrate dehydrogenase; Steele MI et al.; A 5417-base pair (bp) region of Pseudomonas aeruginosa PAO chromosomal DNA containing the mmsAB operon and an upstream regulatory gene (mmsR) has been cloned and characterized . The operon contains two structural genes involved in valine metabolism: mmsA, which encodes methylmalonate-semialdehyde dehydrogenase; and mmsB, which encodes 3-hydroxyisobutyrate dehydrogenase . mmsA and mmsB share the same orientation and are separated by a 16-bp noncoding region . The transcriptional start site for the operon has been pinpointed to a cytidine residue located 77 bp from the translational start site of the operon . mmsR is located on the opposite strand and begins 134 bp from the translational start site of mmsA . MmsR has been identified as a member of the XylS/AraC family of transcriptional regulators and appears to act as a positive regulator of the mmsAB operon . Sequence comparison of MmsA to other proteins in the data bases revealed that MmsA belongs to the aldehyde dehydrogenase (NAD+) superfamily . MmsB shares a 44% amino acid identity with 3-hydroxyisobutyrate dehydrogenase from rat liver . Mutants with insertionally inactivated mmsR, mmsA, and mmsB grow slowly on valine/isoleucine medium and exhibit reduced enzyme activity in cell-free extracts compared to P . aeruginosa PAO.

Diagn Microbiol Infect Dis, 1992 Jul, 15(5), 435 - 9
Oral ofloxacin for infections caused by bacteria resistant to oral antimicrobial agents; Eron LJ et al.; We conducted an open trial of oral ofloxacin, 400 mg q 12 hr, in the treatment of infections caused by Pseudomonas aeruginosa and other bacteria resistant to traditional oral antibiotics . There were 53 evaluable subjects, 30 having infection of the skin/skin structure, 13 of the respiratory tract, six of bone, and four complicated infections of the genitourinary tract . Most subjects (72%) had previously failed a course of antibiotic therapy for their infections . Ofloxacin therapy was administered an average of 45 days per patient, and was well tolerated . Clinical success was observed in 40 (74%) subjects, with failure in 13 (26%) . Responses ranged from 50% success for six lower respiratory tract infections to 100% success for six cases of osteomyelitis . There were 28 P . aeruginosa with 22 Gram-positive and 24 other Gram-negative infections . Of 28 cases in which P . aeruginosa was implicated as a pathogen, 19 (68%) were successfully treated with ofloxacin therapy . Overall, 63 (85%) of 74 pathogens were eradicated . Of the 11 persistent organisms, five were P . aeruginosa in which resistance to ofloxacin emerged during therapy . Our data imply ofloxacin to be effective for infections due to ofloxacin-susceptible organisms other than P . aeruginosa; for this pathogen, ofloxacin therapy is associated with a high degree of failure . If ofloxacin is used for infection due to P . aeruginosa, microbiologic surveillance is necessary for cases that either fail to respond or relapse clinically.

Infect Immun, 1992 Jul, 60(7), 2808 - 14
Comparison of adherence of Pseudomonas aeruginosa to respiratory epithelial cells from cystic fibrosis patients and healthy subjects; Saiman L et al.; The adherence of Pseudomonas aeruginosa PAO1 to primary cultures of cystic fibrosis nasal polyp (CFNP), normal human nasal polyp (NHNP), and immortalized CF and normal cell lines was studied . PAO1 bound significantly more to primary CFNP cells than to NHNP cells as the mean adherence +/- standard deviation of 5 x 10(7) CFU of 35S-labeled bacteria per ml per well was 15.09 x 10(6) +/- 4.25 x 10(6) CFU/ml per well and 7.62 x 10(6) +/- 2.11 x 10(6) CFU/ml per well, respectively (Mann-Whitney U test, P less than 0.0001) . There was no significant difference in PAO1 adherence to the immortalized CF and normal cell lines . The primary CFNP cells had more receptors (115 per cell) than did NHNP cells (34 per cell) . P . aeruginosa binding to CFNP was blocked by GlcNAc, NeuAc, L-Fuc, and D-Gal, while binding to NHNP was blocked only by GlcNAc, suggesting that receptors on the two cell types were qualitatively different . Pseudomonas supernatants containing protease, phospholipase C, and neuraminidase activity increased adherence to CFNP and NHNP cells . The Pseudomonas exoproducts modified epithelial cell glycoconjugates, as characterized by binding of fluorescein isothiocyanate-labeled lectins and the release of sialic acid . There was minimal release of fibronectin by the bacterial supernatants . The affinity of P . aeruginosa for CF epithelial cells appeared to be due to an increased number of receptors and modification of the epithelial cell surface by P . aeruginosa exoproducts that exposed asialoganglioside binding sites.

Pediatr Infect Dis J, 1992 Jul, 11(7), 542 - 6
Outpatient management of chronic suppurative otitis media without cholesteatoma in children; Dagan R et al.; Prolonged antipseudomonal parenteral antibiotic therapy combined with daily aural toilet has been effective in resolving long standing ear discharge in children with chronic suppurative otitis media . However, such treatment suffered from the disadvantages of prolonged hospitalization . We conducted a prospective study to investigate the feasibility and efficacy of exclusive outpatient treatment of children with chronic suppurative otitis media without cholesteatoma who had failed ototopical/oral antimicrobial therapy . The treatment consisted of daily aural toilet (suction and debridement) and twice daily parenteral ceftazidime (50 mg/kg/dose) . Thirty-seven children were included . The duration of discharge from the ear before treatment was 6 to 121 months (median, 30 months) . Aerobic cultures yielded Pseudomonas aeruginosa in 97%, often with other organisms . The management and follow-up were performed jointly by otolaryngology and infectious diseases physicians using the hospital ambulatory services . The route of ceftazidime administration (intravenous or intramuscular) was chosen according to the parents' and patients' convenience . Discharge stopped within 3 to 20 days (median, 8 days) in all children but one . Seventy-six percent of the 29 children available for follow-up 12 months after treatment were still free of discharge . Our results demonstrate that a regiment combining daily aural toilet and twice daily parenteral ceftazidime is highly efficacious in resolving ear discharge in children with chronic suppurative otitis media without cholesteatoma and that such a regimen does not require hospitalization.

Mikrobiyol Bul, 1992 Jul, 26(3), 271 - 80
{The effectiveness of various disinfection methods on the surface of gloved hands}; Goktas P et al.; The gloved hands were contaminated by using E.coli and Pseudomonas aeruginosa Brain Heart Infusion broth cultures and the efficacy of tap water, unmedicated bar soap, benzalkonium chloride 1% (Zefiran), Na-hypochloride 1% and 5%, alcohol 70%, hexachlorophene 3%, hexachlorophene 3% liquid soap (Solu-heks), chlorhexidine 1.5% liquid soap (Savlon), chlorhexidine 4% liquid soap (Hibiscrub), povidone-iodine 10% solution (Betadine and polyod), povidone-iodine 7.5% liquid soap (Betadine and Polyod) were compared onto the gloved hands . Disinfectants were applied for 30, 45 and 60 seconds . It was found that washing time of 30 seconds with chlorhexidine 4% (Hibiscrub) liquid soap or povidone-iodine 7.5% liquid soap (Betadine and Polyod) was required to eradicate all the organisms inoculated from both glove surfaces . Povidone-iodine and chlorhexidine were more effective washing agents than the other disinfectants . In underdeveloped or developing countries and areas where gloves can not easily supplied, it has been suggested that gloved hands could be washed between patient treatments and gloves re-used in dentistry, gynecology and like the other areas of medicine . Chlorhexidine 4% and povidone-iodine 7.5% liquid soaps are recommended as a hand-washing agents in these areas.

Jpn J Antibiot, 1992 Jul, 45(7), 866 - 79
{Clinical evaluation of a new carbapenem, meropenem, in infants and children}; Meguro H et al.; A new carbapenem antibiotic, meropenem (MEPM), was evaluated for its safety and efficacy in 33 infants and children . MEPM was effective in all the 32 evaluable cases including 4 cases of bacterial meningitis and 5 cases of Pseudomonas aeruginosa infections . The mean half life of plasma concentrations of MEPM was 0.84 +/- 0.09 hours after 30 minutes intravenous drip infusion . Mild diarrhea (2 cases), transient elevation of transaminases (8 cases), and transient eosinophilia (2 cases) were associated with the MEPM therapy, but none of them was problematic . These data suggest that MEPM is safe in infants and children and could be one of the therapeutic agents for severe infections or infections in compromised hosts.

Jpn J Antibiot, 1992 Jul, 45(7), 799 - 808
{Clinical evaluation of combined therapy of ceftazidime and tobramycin for intractable pulmonary infection mainly caused by Pseudomonas aeruginosa}; Kikuchi N et al.; In an open, multicenter trial, we investigated the clinical efficacy of a combination therapy of ceftazidime (CAZ) and tobramycin (TOB) for intractable pulmonary infections mainly caused by Pseudomonas aeruginosa . Evaluated for the utility of the combination therapy were 33 cases with pneumonia (Group I: pneumonia caused by P . aeruginosa 15, Group II: pneumonia caused by other Gram-negative bacilli 4 and pneumonia which causative organism was not determined 14) and 23 cases with chronic respiratory tract infection caused by P . aeruginosa . The results obtained are summarized as follows . 1 . In Group I pneumonia, included 11 severe cases and 4 moderate cases, with a mean age of 69.3 years . Significant underlying diseases were present in 14 out of the 15 (93.3%): they included 10 cases of pulmonary diseases and 4 cerebrovascular diseases . The overall efficacy rate in these cases was 60.0%: but the efficacy rate in moderate cases was 100% and that in severe cases was 45.5% . 2 . In Group II pneumonia included 16 severe cases and 2 moderate cases with a mean age of 68.2 years . Significant underlying diseases were present in 15 out of 18 (83.3%, all of the underlying diseases were pulmonary diseases) and the overall efficacy rate was 72.2% with 100% efficacy rate among moderate cases and 68.8% among severe cases . 3 . In the cases with chronic respiratory tract infections caused by P . aeruginosa, the efficacy rate was 82.6% and the eradication rate was 65.2% . We consider the combination therapy of CAZ and TOB is useful for intractable pulmonary infections caused by P . aeruginosa.

Vet Microbiol, 1992 Jul, 32(1), 63 - 74
Relationship between the immune response of sheep and the population dynamics of bacteria isolated from fleecerot lesions; Chin JC et al.; In sheep wetted by rain, proliferation of bacteria in the skin-fleece microenvironment invariably discolours the fleece and causes a dermatitic condition known as fleecerot . The changes in population dynamics of fleece bacteria were analysed by carrying out skin washings at randomly selected sites on the back of sheep before, and at 48 h and 96 h after exposure to rain . Gram-positive rods belonging to Bacillus species (10(2)-10(4) cfu/cm2) predominated in dry fleece . Gram-positive cocci (e.g . Micrococcus and Staphylococcus species) as well as Gram-negative rods (pseudomonads) were also present but in lower abundance (less than 10(2) cfu/cm2) . Fleece bacterial populations generally increased in numbers during the first 24-48 h of wetting . By 96 h however, skin washings showed a preponderance of Pseudomonas aeruginosa (10(4)-10(6) cfu/cm2) and to a lesser extent, pigmented Micrococcus species . Growth of fleece bacteria was associated with a characteristic green or yellow/orange staining of fleece . Fewer species of bacteria were isolated from sheep showing green staining while those animals with yellow/orange discolourations appeared to have a more mixed microflora composition . The predominance of P . aeruginosa in the wet fleece of sheep displaying either green or yellow/orange bacterial stain, was accompanied by a significant serological response against this species . Since skin bacteria have never been observed to penetrate cutaneously in skin sections biopsied from fleecerot sites, it must be concluded that the sheep skin is sensitized by continuous exposure to antigens that are associated with or released by P . aeruginosa.

Kansenshogaku Zasshi, 1992 Jul, 66(7), 909 - 13
{Growth inhibitory activity of clinical isolates of Pseudomonas aeruginosa against Staphylococcus aureus (MRSA and MSSA)}; Ogino J et al.; Anti staphylococcal activity by clinical isolates of Pseudomonas aeruginosa was tested by the reversed agar plate and the filter paper stamp methods . Almost 40% of Pseudomonas aeruginosa inhibited the growth of both Methicillin resistant Staphylococcus aureus (MRSA) and Methicillin sensitive Staphylococcus aureus (MSSA) . Green pigment (Pyocyanin) produced strains showed a strong inhibitory effect against MRSA and MSSA respectively . But some other pigment (Yellow, Red) strains also showed anti staphylococcal activity . These data suggest the colonization of Pseudomonas aeruginosa with anti staphylococcal activity may not be eradicated by the anti pseudomonic antibiotics.

Int J Pediatr Otorhinolaryngol, 1992 Jul, 24(1), 25 - 33
Medical treatment of chronic suppurative otitis media without cholesteatoma in children--a two-year follow-up; Leiberman A et al.; A prospective long-term study was carried out in 48 infants and children with chronic suppurative otitis media without cholesteatoma treated initially with wide spectrum intravenous antibiotics and suction and debridement . Patients were followed for a period of two years . All children were cured after completion of therapy . At 3 and 6 months follow-up 75% of the children were still free of discharge and at 12, 18 and 24 months the proportion of dry ears dropped to 71%, 66% and 52%, respectively . Eighty percent of all recurrences developed already during the first 6 months of follow-up . Pseudomonas aeruginosa was the most common pathogen isolated, both in the initial and recurrent bouts of the disease, and was commonly associated with other pathogens . Children with early reappearance of ear discharge were less likely to benefit from further antimicrobial or surgical treatment . The recurrence rate was not affected by the antibiotic regimen, age, duration of drainage before treatment or the presence of granulation tissue . No intracranial or intratemporal complications were observed during the follow-up period.

East Afr Med J, 1992 Jul, 69(7), 394 - 7
The bacteriology of chronic suppurative otitis media; Rotimi VO et al.; Specimens obtained directly from the middle ear under direct vision from 40 patients with chronic suppurative otitis media (CSOM) were investigated quantitatively and qualitatively for aerobes and anaerobes . Twenty one of the 40 specimens yielded aerobes only, 17 yielded a mixed flora of anaerobes and aerobes while only one yielded anaerobes only and the remaining one was sterile . Bacteroides fragilis was the commonest anaerobe and the second single most common bacteria generally present in CSOM . Pseudomonas aeruginosa and Staphylococcus aureus were the dominant aerobic flora appearing in 17 and 14 out of 40 specimens respectively . All pathogens isolated were present in very high counts averaging 10(8) ml of the exudate . The use of systemic anti-anaerobic drug combined with an anti-aerobic drug is worthy of a clinical trial.

FEMS Microbiol Immunol, 1992 Jul, 4(5), 267 - 72
Identification of a small epitope in domain Ib of Pseudomonas aeruginosa exotoxin A that elicits enzyme-neutralizing antibodies; Rutault K et al.; A peptide corresponding to amino acids 392-404 of the amino acid sequence of Pseudomonas aeruginosa exotoxin A (the last 13 amino acids of domain Ib) was synthesized and coupled to thyroglobulin . The conjugate induced an antiserum in rabbits with high antibody titer against native toxin as measured by ELISA, and this antiserum was highly efficient in inhibiting the ADP-ribosyltransferase activity of exotoxin A . These data corroborate the potential importance of amino acids 400-404 in the enzymatic mechanism of exotoxin A.

J Clin Microbiol, 1992 Jul, 30(7), 1848 - 55
Antibody responses to lipid A, core, and O sugars of the Pseudomonas aeruginosa lipopolysaccharide in chronically infected cystic fibrosis patients; Kronborg G et al.; Enzyme-linked immunosorbent assays were developed separately for the three main parts of the Pseudomonas aeruginosa lipopolysaccharide (LPS) molecule, namely, lipid A, core, and O polysaccharide . Anti-lipid A, anticore, and anti-O polysaccharide antibodies were measured in serum samples from 12 patients with cystic fibrosis (CF) in a longitudinal study covering the period before P . aeruginosa infection was established through at least 5 years of chronic infection . The serum antibody response to all parts of the P . aeruginosa LPS molecule increased during the course of chronic infection . The increase in anti-lipid A antibodies was specific for P . aeruginosa lipid A, since no increase in anti-Escherichia coli lipid A antibodies was seen . Immunoglobulin G, A, and M (IgG, IgA and IgM) antibodies were all involved in the specific systemic response to P . aeruginosa lipid A, core, and the O polysaccharides . IgG and IgA levels in particular increased during the course of infection and were significantly higher than the antibody increase seen with age in a healthy control group . The local immune response in the lungs was investigated by measuring IgG, IgA, and IgM antibodies to the separate parts of the P . aeruginosa LPS molecule in sputum samples from 18 CF patients with at least a 5-year history of chronic P . aeruginosa infection . Antibodies detected in sputum were mainly anti-lipid A and anti-O polysaccharide antibodies of the IgG and IgA isotypes . Very high IgA anti-lipid A titers were detected in sputum samples from some CF patients.

Antimicrob Agents Chemother, 1992 Jul, 36(7), 1352 - 7
Effects of the combination of lipopolysaccharide-specific monoclonal antibodies and sparfloxacin against Pseudomonas aeruginosa pneumonia in neutropenic mice; Oishi K et al.; The effects of the combination of a murine monoclonal antibody (MAb) specific for the O side chain of Pseudomonas aeruginosa Fisher immunotype 1 lipopolysaccharide and sparfloxacin in a neutropenic mouse model of P . aeruginosa pneumonia were examined . Under the condition that neither MAb at a dose of 500 micrograms per mouse administered intravenously nor a suboptimal dose of oral sparfloxacin (5 mg/kg of body weight) protected mice from challenge with a fatal dose, the combination therapy with MAb and sparfloxacin caused a significant increase in the survival rate (P less than 0.001 compared with either treatment alone) . The effect of the combination was closely correlated to bacterial killing in plasma and lung tissue of infected mice . In vitro, a significant MAb-dependent, complement-mediated killing of P . aeruginosa was documented in the presence of sparfloxacin at one-half the MIC, while the killing was not observed in the absence of sparfloxacin . These in vivo and in vitro data suggest the usefulness of combination therapy with a lipopolysaccharide-reactive immunoglobulin G MAb and sparfloxacin in neutropenic patients with P . aeruginosa pneumonia.

Prostaglandins Leukot Essent Fatty Acids, 1992 Jul, 46(3), 203 - 10
Reduction of eicosanoid production by essential fatty acid depletion does not attenuate the inflammatory response induced by Pseudomonas aeruginosa pneumonia in rat lung; O'Sullivan BP et al.; Sipid mediators of inflammation have been implicated in the pathogenesis of Pseudomonas aeruginosa (PA) related pulmonary damage in patients with cystic fibrosis . We studied the role of these mediators in a rat model of PA endobronchitis using essential fatty acid deficient (EFAD) animals . Whole blood from EFAD animals produced significantly less leukotriene B4 (LTB4) and hydroxyheptadecatrienoic acid when stimulated ex vivo than did whole blood from control animals (p less than 0.005) . Similarly, lung lavage fluid from EFAD animals infected with PA contained less LTB4 and thromboxane B2 (TXB2) than that from control animals . Despite these differences, cellular infiltration of airways in response to PA infection was virtually identical in animals from the regular diet and the EFAD groups . Both EFAD and control animals had a significant increase in white blood cells (WBC) in lung lavage fluid at 1, 3 and 6 days following infection with PA when compared to animals receiving sterile beads . Localized areas of consolidation and nodularity were grossly evident in the lungs of all PA infected animals irrespective of their ability to generate the lipid inflammatory mediators . Microscopic examination of lung sections demonstrated similar changes in all infected animals . We conclude that LTB4 and TXB2 production occurs early in the course of PA pulmonary infection in rats . This early rise in lipid mediators is temporally associated with an influx of WBC into the airways . However, attenuation of eicosanoid production by use of an EFAD diet does not lead to a reduction in the inflammatory response to PA infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Am Rev Respir Dis, 1992 Jul, 146(1), 224 - 31
Hepatic versus pulmonary uptake of particles injected into the portal circulation in sheep . Endotoxin escapes hepatic clearance causing pulmonary inflammation; DeCamp MM et al.; Removal of circulating particulates (bacteria, cell debris, endotoxin) is accomplished in most species by macrophages resident in the liver and spleen . We have shown that sheep and other species have phagocytic macrophages resident in their pulmonary capillaries . Moreover, these pulmonary intravascular macrophages accomplish the bulk of uptake of injected tracer particles, bacteria, or endotoxin (LPS) . Because bacteria or LPS of intestinal origin enter the portal circulation, they would first encounter hepatic mononuclear phagocytes . We sought to determine the extent to which particulates injected into the portal circulation of sheep would be taken up by liver or by lung macrophages . Sheep (four per group) were injected via a mesenteric vein with radiolabeled gold colloid, magnetic iron oxide particles, live Pseudomonas aeruginosa, or 125I E . coli endotoxin . For each, the uptake pattern was determined 1 h after injection . Lung and liver were also fixed to determine the cells responsible for uptake and subsequent inflammatory changes . We found that for circulating gold colloid, iron oxide particles, or bacteria, hepatic uptake predominated, and Kupffer cells were responsible . After hepatic uptake of bacteria, inflammatory changes were confined to the liver . In contrast, nearly 50% of endotoxin escaped hepatic clearance and was subsequently removed by the lungs . We then saw inflammatory changes in both lungs and liver . Thus, hepatic macrophages are active in species with pulmonary intravascular macrophages, partially sparing the lungs from uptake and acute inflammation . Endotoxin, however, may elude hepatic uptake, be sequestered in the lungs, and initiate inflammation there.

J Bacteriol, 1992 Jul, 174(14), 4847 - 9
The pyocin Sa receptor of Pseudomonas aeruginosa is associated with ferripyoverdin uptake; Smith AW et al.; We have used Tn5 mutagenesis to obtain a mutant resistant to pyocin Sa . When grown in iron-deficient succinate medium this mutant lacked an 85-kDa iron-regulated outer membrane protein (IROMP), and expression of a 75-kDa IROMP was increased compared with that in the parent strain . The mutant was deficient in pyoverdin biosynthesis and showed a 95% decrease in transport of ferripyoverdin purified from the parent strain, suggesting that the 85-kDa IROMP is the specific receptor for ferripyoverdin and pyocin Sa . The mutant compensated for the deficiency in pyoverdin biosynthesis and transport by exhibiting a fourfold increase in ferripyochelin transport . The low-level transport of ferripyoverdin in the Sa-resistant mutant, which extended to heterologous pyoverdins from other strains, suggests that Pseudomonas aeruginosa has a second ferripyoverdin uptake system of lower affinity and broader specificity.

J Bacteriol, 1992 Jul, 174(13), 4401 - 9
Cloning of the outer membrane high-affinity Fe(III)-pyochelin receptor of Pseudomonas aeruginosa; Ankenbauer RG; Pseudomonas aeruginosa produces the phenolic siderophore pyochelin under iron-limiting conditions . In this study, an Fe(III)-pyochelin transport-negative (Fpt-) strain, IA613, was isolated and characterized . 55Fe(III)-pyochelin transport assays determined that no Fe(III)-pyochelin associated with the Fpt- IA613 cells while a significant amount associated with KCN-poisoned Fpt+ cells . A P . aeruginosa genomic library was constructed in the IncP cosmid pLAFR1 . The genomic library was mobilized into IA613, and a recombinant cosmid, pCC41, which complemented the Fpt- phenotype of IA613, was isolated . pCC41 contained a 28-kb insert of P . aeruginosa DNA, and the Fpt(-)-complementing region was localized to a 3.6-kb BamHI-EcoRI fragment by deletion and subcloning of the insert . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of IA613 revealed that it lacked a 75-kDa outer membrane protein present in Fpt+ strains . IA613 strains bearing plasmid pRML303, which carries the 3.6-kb BamHI-EcoRI fragment of pCC41, expressed the 75-kDa outer membrane protein and demonstrated a 55Fe(III)-pyochelin transport phenotype identical to that of a wild-type Fpt+ strain . Minicell analysis demonstrated that the 3.6-kb BamHI-EcoRI fragment of pCC41 encoded a protein of approximately 75 kDa . The results presented here and in a previous report (D . E . Heinrichs, L . Young, and K . Poole, Infect . Immun . 59:3680-3684, 1991) lead to the conclusion that the 75-kDa outer membrane protein is the high-affinity receptor for Fe(III)-pyochelin in P . aeruginosa.

Surgery, 1992 Jul, 112(1), 45 - 55
The neutrophil respiratory burst and tissue injury in septic acute lung injury: the effect of cyclooxygenase inhibition in swine; Carey PD et al.; Cyclooxygenase inhibition has been proposed as treatment for sepsis-induced acute lung injury . However, the mechanism of protection offered by the cyclooxygenase inhibitor ibuprofen is not well understood . To elucidate this mechanism, the effects of ibuprofen on the neutrophil respiratory burst and alveolar-capillary membrane leak were studied . Anesthetized swine (15 to 25 kg) were intubated and mechanically ventilated (fraction of inspired oxygen, 0.5) . Control animals (n = 5) received a sham infusion of 0.9% NaCl, animals with sepsis (n = 10) received a 1-hour infusion of live Pseudomonas aeruginosa (5 x 10(8) colony-forming units/ml at 0.3 ml/20 kg/hr), and treated animals (ibuprofen-treated control animals {n = 4} or ibuprofen-treated animals with sepsis {n = 9}) received ibuprofen (12.5 mg/kg at 0 and 120 minutes) . All animals were studied for 300 minutes . Neutrophils were isolated at 0, 60, and 300 minutes . Neutrophil superoxide anion production (O2-) was assessed in a kinetic fashion (in nanomoles per minute) by superoxide dismutase-inhibitable cytochrome C reduction (phorbol myristate acetate stimulation) . Bronchoalveolar lavage protein estimation (0 and 300 minutes) and extravascular lung water (double indicator dilution) were performed to assess alveolar-capillary membrane leak . Ibuprofen significantly attenuated sepsis-enhanced maximum neutrophil generation of O2- (6.0 +/- 0.5 nmol/min for animals with sepsis, 300 minutes, vs 4.1 +/- 0.5 nmol/min for ibuprofen-treated animals, with sepsis, 300 minutes; p less than 0.05), indicating an in vivo down-regulatory effect on neutrophil oxidant generation . Ibuprofen also prevented increased airspace bronchoalveolar lavage protein and extravascular lung water accumulation, suggesting a protective effect on the alveolar-capillary membrane . This protective effect of ibuprofen in acute lung injury may be through a decreased neutrophil respiratory burst.

Lancet, 1992 Jun 27, 339(8809), 1583 - 7
Intermediate-term results of heart-lung transplantation for cystic fibrosis; Madden BP et al.; Between September, 1984, and March, 1991, 79 patients underwent heart-lung transplantation for end-stage cystic fibrosis at the Harefield Hospital . Short-term outcome has already been reported, and we now present intermediate-term results . The overall actuarial patient survival was 69% at 1 year, 52% at 2 years, and 49% at 3 years . 17 patients had diabetes mellitus with a survival of 62% to 1 year and 51% to 2 years . 23 patients had one or more other possible high-risk factors, and survival of these patients was 64% at 1 year and 57% at 2 years, compared with 71% and 49%, respectively, in the low-risk group (n = 56) . Pseudomonas aeruginosa infection was the most common respiratory infection encountered postoperatively . 92% of patients had at least one episode of acute rejection during the first 3 postoperative months . Lung function was greatly improved after transplantation, the mean forced expiratory volume in 1 s and forced vital capacity increasing from 22% and 35% predicted, respectively, preoperatively to 68% and 70% predicted, respectively, by the sixth postoperative month . This improvement was maintained at 1, 2, and 3 years after transplantation . Lymphoproliferative disorders (4 patients) were successfully treated . Obliterative bronchiolitis developed in 17 patients and the cumulative probability of getting this complication at 1, 2, and 3 years postoperatively was 17%, 23%, and 48%, respectively . Overall, 7 patients were retransplanted . There was no coronary artery disease in the 37 patients who underwent coronary angiography at 1 year, 14 at 2 years, and 9 at 3 years after surgery . 58 patients donated their hearts for subsequent "domino" heart transplantation . Our 5 1/2-year experience with heart-lung transplantation is encouraging but the shortage of donor organs and the complication of obliterative bronchiolitis are the two main obstacles to be overcome.

Biochim Biophys Acta, 1992 Jun 12, 1116(3), 331 - 3
On the specificity of the D-galactose-binding lectin (PA-I) of Pseudomonas aeruginosa and its strong binding to hydrophobic derivatives of D-galactose and thiogalactose; Garber N et al.; The D-galactose-binding lectin (PA-I) from the bacterium Pseudomonas aeruginosa, isolated by affinity chromatography on Sepharose, was examined for its relative affinities for simple sugars and their derivatives using equilibrium dialysis and hemagglutination inhibition tests . The lectin, which was found to bind 0.68 mol of D-galactose per subunit of 12.8 kDa, exhibited an association constant (Ka) of 3.4 x 10(4) M-1 for D-galactose and higher affinities for hydrophobic and thio derivatives of D-galactose (with highest affinity for the hydrophobic thio derivatives) . alpha-Methyl-galactoside was a stronger inhibitor than the beta-methyl derivative and alpha-lactose was a weak inhibitor but the hydrophobic phenylated derivatives of the beta-configuration of D-galactose were more potent inhibitors than the respective alpha-galactosides.

Rev Esp Enferm Dig, 1992 Jun, 81(6), 417 - 8
{Phlegmonous gastritis . Report of a case induced by Pseudomonas aeruginosa}; Ramos Jimenez FA et al.; The authors present a case of phlegmonous gastritis in a 65 year old patient . The diagnosis was made in the operating room and the treatment was conservative; no gastric resection was done . This clinical entity is interesting because it is a least frequent pathology, the pathogenic bacteria which was the cause (Pseudomona aeruginosa) has at this time not been reported in the literature, including the favorable outcome of the patient without gastric resection.

Ophthalmology, 1992 Jun, 99(6), 889 - 92
Evaluation of corneal collagen shields as a drug delivery device for the treatment of experimental Pseudomonas keratitis; Silbiger J et al.; PURPOSE: To clarify the role of corneal collagen shields as a drug delivery device for the treatment of bacterial keratitis, the authors studied the effectiveness of topical gentamicin treatment, with and without the use of corneal collagen shields, in a rabbit model of Pseudomonas keratitis . METHODS: Forty-eight New Zealand white rabbits were infected by injecting 500 colony-forming units (CFU) of Pseudomonas aeruginosa into the corneal stroma, and treatment was begun 24 hours later . A 13.6 mg/ml solution of gentamicin was topically administered during a 24-hour period . Collagen shields were soaked in gentamicin 13.6 mg/ml for 5 minutes before placing them on the cornea . Corneas were quantitatively cultured 1 hour after the treatment period ended . Six different groups of rabbits were tested, with the results analyzed as the mean log10 of bacterial CFU . RESULTS: An untreated control group had significantly more bacteria (7.96 +/- 0.74) than any of 5 treatment groups . No difference was found between groups given a loading dose of antibiotic drops at the beginning of treatment, either with (4.90 +/- 2.41) or without (6.25 +/- 0.54) an antibiotic-impregnated collagen shield . A group treated with a collagen shield augmented with gentamicin drops every 3 hours had fewer bacteria (1.52 +/- 1.82) than a group receiving drops alone (4.15 +/- 1.83) (P less than 0.05) . However, treatment with a collagen shield supplemented with drops every 3 hours was not as effective as gentamicin drops administered every 30 minutes (no bacterial growth) (P less than 0.05) . CONCLUSION: These results show that antibiotic-impregnated collagen shields should not replace traditional antibiotic drop therapy as the mainstay of treatment but may be a useful adjunct to treatment with topical antibiotics.

J Appl Physiol, 1992 Jun, 72(6), 2271 - 7
Effect of Pseudomonas aeruginosa rhamnolipids on mucociliary transport and ciliary beating; Read RC et al.; Pseudomonas aeruginosa rhamnolipid causes ciliostasis and cell membrane damage to rabbit tissue, is a secretagogue in cats, and inhibits epithelial ion transport in sheep tissue . It could therefore perturb mucociliary clearance . We have investigated the effect of rhamnolipid on mucociliary transport in the anesthetized guinea pig and guinea pig and human respiratory epithelium in vitro . Application of rhamnolipid to the guinea pig tracheal mucosa reduced tracheal mucus velocity (TMV) in vivo in a dose-dependent manner: a 10-microgram bolus caused cessation of TMV without recovery; a 5-micrograms bolus reduced TMV over a period of 2 h by 22.6% (P = 0.037); a 2.5-microgram bolus caused no overall changes in TMV . The ultrastructure of guinea pig tracheal epithelium exposed to 10 micrograms of rhamnolipid in vivo was normal . Application of 1,000 micrograms/ml rhamnolipid had no effect on the ciliary beat frequency (CBF) of guinea pig tracheal rings in vitro after 30 min, but 250 micrograms/ml stopped ciliary beating after 3 h . Treatment with 100 micrograms/ml rhamnolipid caused immediate slowing of the CBF (P less than 0.01) of human nasal brushings (n = 7), which was maintained for 4 h . Mono- and dirhamnolipid had equivalent effects . The CBF of human nasal turbinate organ culture was also slowed by 100 micrograms/ml rhamnolipid, but only after 4 h (CBF test, 9.87 +/- 0.41 Hz; control, 11.48 +/- 0.27 Hz; P less than 0.05, n = 6), and there was subsequent recovery by 14 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Arch Dis Child, 1992 Jun, 67(6), 737 - 40
IgG antibodies in early Pseudomonas aeruginosa infection in cystic fibrosis; Cordon SM et al.; The relationship between IgG antibodies to Pseudomonas aeruginosa and its isolation from sputum was determined in 100 patients with cystic fibrosis observed at intervals of two months for a median period of one year . Only one patient had a raised antibody titre (greater than 22.9 ELISA units) before isolation of P aeruginosa . Initially 65 patients were antibody negative, of whom 48 were also culture negative . Of 24 patients with positive sputum culture and negative antibodies, seven became antibody positive at a median (range) 15 (6-25) months later . The remaining 17 patients continued antibody negative until the end of the study at a median range 15 (1-123) months after becoming culture positive . This latter group were younger and had more intermittently positive sputum cultures . In general positive IgG antibody titres do not predate isolation of P aeruginosa, but in some patients are present soon after acquisition of infection . A positive titre indicates significant exposure to P aeruginosa and could be used to detect infection in patients unable to produce sputum and possibly indicate the effect of early antipseudomonal treatment.

Appl Environ Microbiol, 1992 Jun, 58(6), 2046 - 52
Application of DNA probes to analysis of bacteriophage distribution patterns in the environment; Ogunseitan OA et al.; Radiolabeled bacteriophage DNA probes have been used in this study to determine the distribution of Pseudomonas aeruginosa-infecting bacteriophages in natural samples of lake water, sediment, soil, and sewage . The sensitivity of detection of bacteriophage with the DNA probes was between 10(3) and 10(4) PFU and 10(6) to 10(7) CFU of lysogenized bacteria detectable with a homologous phage DNA probe . Analyses of environmental samples suggest that up to 40% of P . aeruginosa in natural ecosystems contain DNA sequences homologous to phage genomes . By using different bacteriophage DNA probes, the diversity of the bacteriophage population in sewage was estimated to be higher than that in other natural samples . The indication that transducing phages and prophages are widely distributed in the Pseudomonas populations investigated has considerable implications for the frequency of natural gene transfer by transduction and of lysogenic conversion of host bacteria in natural ecosystems.

J Med Microbiol, 1992 Jun, 36(6), 437 - 44
Quantitative analysis of immunoglobulin G subclass responses to Pseudomonas aeruginosa antigens in cystic fibrosis; Likavcanova E et al.; The four subclasses of IgG have different structures, functions and implications in the antibody response . IgG subclass reactions to individual Pseudomonas aeruginosa structural antigens in 22 adolescents and young adults with cystic fibrosis (CF) were studied qualitatively and quantitatively by densitometric analysis of Western blot assays . These patients had been infected by P . aeruginosa for 7 years or longer and were divided into two groups according to their pulmonary status: Group 1 comprised 11 patients with relatively good pulmonary status; Group 2 consisted of 11 patients with poor pulmonary status . There was a relative decrease of IgG1 and a relative increase of IgG2 and, especially, of IgG3 and IgG4 antibodies against P . aeruginosa antigens in the CF patients . Comparison of the two CF patient groups showed a significant increase in the proportion of IgG3 in the Group 2 patients . This could be a potential cause or effect in the deterioration of their pulmonary function . Densitometric analysis of Western blots revealed more than 24 P . aeruginosa antigens and indicated those that were the targets of the isotype antibody response(s) that were apparently most harmful . Thus, there was a significant increase of IgG2 or IgG3 reactivity (or of both) against proteins F, H (H1 and H2), and I in the Group 2 patients . One other striking observation of this study was the high reactivity of IgG4 antibodies to protein H . IgG4 was the major antibody to this protein in seven of the 11 Group 1 patients compared to two of the 11 in Group 2 . We hypothesise that IgG4 antibodies may antagonise IgG2 antibodies, helping to preserve stable pulmonary function.

J Bacteriol, 1992 Jun, 174(12), 4140 - 7
Efficient production and processing of elastase and LasA by Pseudomonas aeruginosa require zinc and calcium ions; Olson JC et al.; The ability of Pseudomonas aeruginosa to degrade elastin, a major component of connective tissue, likely contributes to its pathogenicity and multiplication in human tissues . Two extracellular enzymes are required for P . aeruginosa elastolytic activity: elastase and LasA . Elastase is a zinc metalloprotease, but little is known about the structure of LasA . When grown under metal ion-deficient conditions, P . aeruginosa culture supernatants were found to exhibit a low level of elastolytic activity, which coincided with production of low levels of the 51-kDa proelastase and no detectable LasA . By using this fact to identify factors that promote elastolytic activity, P . aeruginosa PAO1, FRD2, and DG1 were grown in metal ion-deficient medium supplemented with zinc (10(-4) M ZnCl2), calcium (2.5 x 10(-3) M CaCl2), or iron (10(-4) M FeCl3) . High levels of proteolytic and elastolytic activity were exhibited by all strains when cultured in the presence of both zinc and calcium, and this was associated with the production of mature 33-kDa elastase and 21-kDa LasA . Supplementing DG1 and PAO1 cultures with zinc alone stimulated the production of 33-kDa elastase, which, because of the calcium-deficient conditions, exhibited low proteolytic and elastolytic activities . Zinc also stimulated the production of a 41-kDa form of LasA in DG1 and PAO1 culture supernatants . Elastase production by FRD2 cultured in the presence of zinc alone differed from that by the other two strains in that supernatants contained 33-kDa elastase, a 21-kDa form of LasA, and exhibited high proteolytic and elastolytic activities . Such strain-associated differences in LasA processing and elastase activity can be explained by differences in metal ion-scavenging mechanisms adapted by the strains . Supplementing cultures with calcium stimulated the production of elastase but had no effect on LasA production . The elastase produced exhibited variable sizes, possibly resulting from aberrant processing reactions, and showed little proteolytic activity . Proteolytic activity could be recovered from 33-kDa elastase produced in the presence of calcium by inclusion of zinc in the enzymatic assay . Although iron was previously found to exert a repressive effect on P . aeruginosa elastolytic activity, iron exerted little effect on elastolytic activity when added to cultures containing both zinc and calcium . These studies support the conclusion that elastase production and processing are promoted by both zinc and calcium . LasA production, in comparison, is stimulated by zinc, with both zinc and calcium facilitating its processing . The association of 41-kDa LasA with a low level of elastolytic activity and of 21-kDa LasA with a high level of activity supports the conclusion that lasA encodes a larger, precursor protein which is processed to an active 21-kDa form during secretion.

Crit Care Med, 1992 Jun, 20(6), 740 - 5
Colonization of dental plaque by respiratory pathogens in medical intensive care patients; Scannapieco FA et al.; OBJECTIVE: To assess the prevalence of oral colonization by respiratory pathogens in a group of ICU patients, with specific attention to dental plaque and the oral mucosa . DESIGN: Prospective, nonrandomized study with age-matched controls . SETTINGS: Medical ICU in a tertiary-care Veterans Affairs Medical Center and a dental school outpatient preventive dentistry clinic . PATIENTS: Nonconsecutive, unselected patients admitted to the medical ICU during a 2-month period; controls were age-matched patients seen for the first time in the preventive dentistry clinic . INTERVENTIONS: None . MEASUREMENTS: Oral hygienic status was assessed in both groups using a semiquantitative system . Quantitative cultures of dental plaque and buccal mucosa were done within 12 hrs of medical ICU admission and every third day thereafter until discharge/death from the medical ICU . In controls, cultures of plaque and buccal mucosa were done on the initial visit only . Severity of illness of medical ICU patients was quantitated using the Acute Physiology and Chronic Health Evaluation (APACHE II) system and McCabe-Jackson criteria . MAIN RESULTS: Oral hygiene of medical ICU patients was poor . These patients had a mean plaque score (1.9 +/- 0.2) that was significantly greater than that same score seen in outpatients of the preventive dentistry clinic (1.4 +/- 0.1; p less than .005) . Plaque and/or oral mucosa of 22 (65%) of 34 medical ICU patients were colonized by respiratory pathogens, in contrast to only four (16%) of 25 preventive dentistry clinic patients (p less than .005) . The potential respiratory pathogens cultured from medical ICU patients included methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and ten genera of Gram-negative bacilli . Colonization by respiratory pathogens was statistically associated with concomitant antibiotic therapy within the medical ICU group of patients, but not with severity of illness . Although medical ICU patients tended to have more dental plaque than preventive dentistry clinic patients, there was no statistically significant association noted between the presence of dental plaque and respiratory pathogen colonization . CONCLUSIONS: These findings suggest that bacteria commonly causing nosocomial pneumonia colonize the dental plaque and oral mucosa of intensive care patients . In many cases, this colonization occurs by large numbers of bacteria . Dental plaque may be an important reservoir of these pathogens in medical ICU patients . Efforts to improve oral hygiene in medical ICU patients could reduce plaque load and possibly reduce oropharyngeal colonization.

Infect Immun, 1992 Jun, 60(6), 2470 - 4
The glycerolipid receptor for Helicobacter pylori (and exoenzyme S) is phosphatidylethanolamine; Lingwood CA et al.; We have previously shown that Helicobacter pylori specifically binds to a glycerolipid species preferentially found in the antrum of the human stomach . We now show by high-pressure liquid chromatographic analysis that this species is a form of phosphatidylethanolamine and that H . pylori specifically binds to bona fide phosphatidylethanolamine as detected by a thin-layer chromatogram overlay procedure . Considerable variation in the binding of H . pylori to phosphatidylethanolamine from different sources was observed, however, suggesting the importance of the nature of the long-chain hydrophobic moiety . A similar binding specificity was shown by exoenzyme S from Pseudomonas aeruginosa, consistent with our hypothesis that that an exoenzyme S-like adhesin is responsible for the binding of H . pylori to its lipid receptors.

Infect Immun, 1992 Jun, 60(6), 2465 - 9
Preliminary characterization of Pseudomonas aeruginosa peptide chemotactins for polymorphonuclear leukocytes; Fontan PA et al.; In a previous report, we showed that supernatants of Pseudomonas aeruginosa cultures exhibit chemotactic activity for polymorphonuclear leukocytes (PMNL) . In this study, P . aeruginosa chemotactins were isolated, purified, and partially characterized . The organisms were cultured in Vogel-Bonner defined medium, and cultures were stopped in late log phase . Chemotactins withstood heating, remained unaltered after acid or alkali treatment in a pH range from 4 to 10, and resisted digestion by trypsin or carboxypeptidase, but chemotactic activity was decreased by 73% after incubation with pronase . Only 2% of the total chemotactic activity of culture supernatants could be extracted with chloroform . Chemotactins with molecular sizes less than 3 kDa constituted the largest contribution to the chemotactic activity of culture supernatants . Pretreatment of PMNL with 10(-5) M formylmethionyl-leucyl-phenylalanine (FMLP) inhibited chemotaxis towards FMLP and P . aeruginosa culture supernatants but not towards complement component C5a . In conclusion, the total chemotactic activity for PMNL of P . aeruginosa culture supernatants was due, almost exclusively, to chemotactins that have properties similar, if not identical, to those exhibited by formylmethionyl peptides.

J Infect Dis, 1992 Jun, 165(6), 1033 - 41
beta-Lactam antibiotic-induced release of free endotoxin: in vitro comparison of penicillin-binding protein (PBP) 2-specific imipenem and PBP 3-specific ceftazidime; Jackson JJ et al.; The relative effects of two beta-lactam antibiotics, penicillin-binding protein (PBP) 2-specific imipenem and PBP 3-specific ceftazidime, upon in vitro induction of lipopolysaccharide (LPS) release were investigated against smooth- and rough-LPS mutant isolates of Pseudomonas aeruginosa . Free LPS liberated from both isolates are 10- to 40-fold higher for ceftazidime-exposed cultures than control or imipenem-treated cultures after 4-8 h at 35 degrees C despite equivalent MICs . Lethalities of filtrates in mice correlated with in vitro endotoxin assay results . Sub-MIC levels of ceftazidime induced filamentation and LPS release without significant bacterial lysis . Amounts released not only matched the quantities achieved at inhibitory concentrations (e.g., 1-, 2-, and 50-times MIC) of ceftazidime but significantly exceeded levels of LPS liberated by exposure to imipenem, less than or equal to 100 times its MIC . Sub-MIC levels of imipenem released relatively small amounts of free LPS while reducing colony counts approximately 2 logs more than equivalent amounts of ceftazidime after 2 h . Data suggest that ceftazidime-induced filamentation releases larger quantities of bioreactive LPS than nonfilamentous fast-lysing imipenem.

Am J Respir Cell Mol Biol, 1992 Jun, 6(6), 652 - 7
Interaction of Pseudomonas aeruginosa with human lung fibroblasts: role of bacterial elastase; Azghani AO et al.; Colonization of cell surfaces by Pseudomonas aeruginosa is mediated by bacterial adherence, which, in turn, is influenced by both host and microbial factors . Previous studies with this organism suggest that elastase contributes to tissue invasion and necrosis . We studied the effects of Pseudomonas elastase (PE) on the adherence of P . aeruginosa to human lung fibroblast monolayers . Treatment of fibroblasts with PE (1 microgram/ml or 0.06 U/ml) increased adherence of 35S-labeled P . aeruginosa to cells, but heat-inactivated PE did not affect bacterial adhesion . Immunocytochemistry of cultured cells showed that PE (0.06 to 0.63 U/ml) decreased fibronectin (Fn) on the cell surface and extracellular matrix of cultured human lung fibroblasts . Data obtained by cytofluorography indicated that elastase also decreased Fn receptors on fibroblasts . Additional evidence for Fn degradation was provided by SDS-PAGE analysis of soluble Fn and proteins from surface iodinated cell monolayers treated with PE . We conclude that the increased bacterial adherence to fibroblasts may be due, in part, to elastase-induced proteolysis of Fn and its receptors on cell surfaces . Degradation of Fn could thus influence the extent and course of Pseudomonas infection in the lungs.

J Gen Microbiol, 1992 Jun, 138 ( Pt 6), 1283 - 7
Utilization of 2-aminoethylarsonic acid in Pseudomonas aeruginosa; Lacoste AM et al.; This paper describes the metabolism, transport and growth inhibition effects of 2-aminoethylarsonic acid (AEA) and 3-aminopropylarsonic acid (APrA) . The former compound supported growth of Pseudomonas aeruginosa, as sole nitrogen source . The two arsonates inhibited the growth of this bacterium when 2-aminoethylphosphonic acid (AEP) but not alanine or NH4Cl, was supplied as the only other nitrogen source . The analogy between AEA and the natural compound AEP led us to examine the in vitro and in vivo interaction of AEA with the enzymes of AEP metabolism . The uptake system for AEP (Km 6 microM) was found to be competitively inhibited by AEA and APrA (Ki 18 microM for each) . AEP-aminotransferase was found to act on AEA with a Km of 4 mM (3.85 mM for AEP) . Alanine and 2-arsonoacetaldehyde was generated concomitantly, in a stoichiometric reaction . In vivo, AEA was catabolized by the AEP-aminotransferase since it was able to first induce this enzyme, then to be an efficient substrate . The lower growth observed may have been due to the slowness with which the permease and the aminotransferase were induced, and hence to a poor supply of alanine by transamination.

Thorax, 1992 Jun, 47(6), 426 - 8
Extrapulmonary sites of Pseudomonas aeruginosa in adults with cystic fibrosis; Taylor RF et al.; BACKGROUND: Pseudomonas aeruginosa infection is seldom eradicated in patients with cystic fibrosis despite intensive antipseudomonal treatment . Upper airway sites of infection may contribute to perpetuation of lower airways infection . This study was designed to find out which extrapulmonary sites are infected and whether the strains at these sites are identical to those in the lungs . METHODS: Sputum and upper airway samples from 42 patients were cultured for P aeruginosa and stool samples from 20 patients were also tested . Nineteen isolates from sputum and extrapulmonary sites from four patients were genotyped with the pCM tox probe . RESULTS: P aeruginosa was isolated from the sputum of 36 patients, 34 of whom had infection in the upper airways . Six of the 20 patients tested were positive for P aeruginosa in the stool . The nasopharynx was colonised in 30 patients, the oropharynx in 29, the middle meatus in 13, the external nares in six, and the inferior turbinate in four . Three of four patients tested had the same strain of P aeruginosa (a different one in each individual) in the sputum and the upper airways, and in two of the three the stool isolate was a different strain . CONCLUSION: Most adults with cystic fibrosis and P aeruginosa pulmonary infection have upper airway reservoirs of the organism and strains from these sites are identical to those in the lungs.

Mol Microbiol, 1992 Jun, 6(12), 1593 - 604
The role of the pro-sequence in the processing and secretion of the thermolysin-like neutral protease from Bacillus cereus; Wetmore DR et al.; The Bacillus cereus cnp gene coding for the thermolysin-like neutral protease (TNP) has been cloned, sequenced, and expressed in Bacillus subtilis . The protease is first produced as a pre-pro-protein (M(r) = 61,000); the pro-peptide is approximately two-thirds of the size of the mature protein . The pro-sequence has been compared with those of six other TNPs, and significant homologies have been found . Additionally, the TNP pro-sequences are shown to be homologous to the pro-sequence of Pseudomonas aeruginosa elastase . A mutant has been constructed from cnp, in which 23 amino acids upstream from the pro-protein processing site have been deleted . This region has no homologous analogue in any of the other TNP pro-sequences . The deletion results in a delay of six to eight hours in detection of active protease in the growth medium, as well as a 75% decrease in maximum protease production . N-terminal analysis of the mutant mature protein demonstrates that the processing site is unaltered by the pro-sequence deletion . The deletion must, therefore, modulate the kinetics of processing and/or secretion of the pro-protein.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1992 Jun, 8(2), 97 - 9, 163
{Quantitative bacterial culture of subeschar tissue . A clinical study}; Chai JK; The relationship between the number of bacteria in the subeschar tissue and time, age, burn extent in 47 patients within a week after burn injury are presented . The results showed 1 . There is a significant positive correlation between the number of bacteria in the subeschar tissue and time intervals following burn within the first week (r = 0.9839, P < 0.01); 2 . In children (below 4 years) and patients over 45 years, there is a higher incidence of having bacterial counts of over 10(5)/gm of tissue than that of young and adolescent patients (P < 0.01); 3 . There is a significant difference in subeschar bacterial count between major burns (> 30% TBSA) and smaller burns (< 30% TBSA P < 0.05); 4 . Pseudomonas aeruginosa is one of the most frequent bacteria isolated, especially in major burns.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1992 Jun, 8(2), 139 - 40, 167
{Plasmid fingerprinting technique analysis of Pseudomonas aeruginosa isolated from a burn unit}; Jia CG; We used plasmid fingerprinting technique to analyse 50 strains of Pseudomonas aeruginosa isolated from our burn unit and 15 strains of Pseudomonas aeruginosa from other wards . The results revealed that the carrier rate of R-plasmid was 100% . All 50 strains of Pseudomonas aeruginosa from burn units contained one plasmid with approximate molecular weight of 55 kb . Among 15 strains of Pseudomonas aeruginosa from other wards, 10 strains contained one plasmid with the same molecular weight . However, 3 strains were found to possess an additional 12.5-kd plasmid and 2 strains contained 77-kb plasmid . This proves that R-plasmid carrying Pseudomonas aeruginosa is prevalent in the burn unit, and R-plasmid is disseminated in the hospital.

Antimicrob Agents Chemother, 1992 Jun, 36(6), 1290 - 5
Effects of a human antiflagellar monoclonal antibody in combination with antibiotics on Pseudomonas aeruginosa infection; Uezumi I et al.; The in vivo activity of human immunoglobulin M monoclonal antibody IN-2A8, which is specific for flagellum type b of Pseudomonas aeruginosa, was evaluated in comparison to anti-O antigen (serotype B) MAb KO-2F2 and in combination with antibiotics . IN-2A8 showed stronger activity than KO-2F2 against subcutaneous infection in burned mice, while it was much less active against intraperitoneal infection in normal mice . In a burn infection model, IN-2A8 inhibited the increase of bacteria in skin lesions weakly and that in blood significantly, suggesting that it strongly suppressed bacterial spread to blood . The activity of IN-2A8 in combination with 10 antipseudomonal antibiotics against intraperitoneal infection was examined . Clear additive effect was observed with a combination of either carbapenem or aminoglycoside antibiotics in terms of mouse survival . The administration of an antibiotic, imipenem-cilastatin, simultaneously with or before that of IN-2A8 gave a combined effect, but the reverse order did not . The combination of IN-2A8 with imipenem-cilastatin decreased numbers of viable bacteria in the peritoneal cavity and blood and kept them low for a longer time than did either treatment alone . These results suggest that an antiflagellar monoclonal antibody would be effective against systemic infection in combination with some kinds of antibiotics.

Antimicrob Agents Chemother, 1992 Jun, 36(6), 1198 - 203
Efficacy of erythromycin lactobionate for treating Pseudomonas aeruginosa bacteremia in mice; Hirakata Y et al.; We induced endogenous Pseudomonas aeruginosa bacteremia by administering cyclophosphamide and ampicillin to specific pathogen-free mice fed P . aeruginosa . Using this model, we evaluated the efficacy of erythromycin lactobionate (EML) in treating P . aeruginosa bacteremia . Treatment with EML at 50 and 100 mg/kg of body weight per day twice a day for 14 days significantly increased the survival rate . The most effective dose was 100 mg/kg/day, with a survival rate of 80% compared with a 20% survival rate in the control . However, the administration of EML at 500 mg/kg/day rather decreased the survival rate . In a model of intravenous infection, treatment with EML at 100 mg/kg/day twice a day for 7 days before the bacterial challenge also enhanced the survival rate . EML levels in serum, liver, and stool were apparently lower than the MIC (512 micrograms/ml) . These observations suggest that EML is effective against P . aeruginosa bacteremia despite a lack of specific activity for this pathogen . Although the protective mechanism is still unclear, it is possible that a subinhibitory level of EML may affect the virulence of P . aeruginosa and enhance the host defense system.

Eur J Biochem, 1992 Jun 1, 206(2), 587 - 93
Monoclonal antibodies against Pseudomonas aeruginosa elastase: a neutralizing antibody which recognizes a conformational epitope related to an active site of elastase; Yokota S et al.; We have established seven murine hybridoma cell lines which produce monoclonal antibodies (mAbs) against Pseudomonas aeruginosa elastase . The seven mAbs recognized at least six different epitopes on the elastase molecule . All mAbs inhibited both enzymatic activities of elastase and protease, in which elastin fluorescein and hide powder azure were used as substrates, respectively . One of them, mAb E-4D3, strongly neutralized enzymatic activities of peptidase in which furylacryloyl-glycyl-leucinamide was used as a substrate, as well as of elastase and protease . In contrast, the other six mAbs did not neutralize peptidase activity at all . The Ki value for furylacryloyl-glycl-leucinamide of E-4D3, as well as its Fab fragment, was comparable to those for metalloprotease inhibitors such as phosphoramidon and Zincov inhibitor . The binding of mAb E-4D3 was inhibited by phosphoramidon and Zincov inhibitor, but not by metal chelators such as EDTA and o-phenanthroline . A line of evidence suggests that mAb E-4D3 directly interacts with active site and highly neutralizes enzymatic activity of P . aeruginosa elastase . Data of Western blotting and ELISA suggest that mAb E-4D3 is likely to recognize an elastase molecule in a conformation-dependent manner as an epitope . In contrast, the neutralizing activity of the other mAbs against elastase and protease seems to be caused by a low accessibility of an enzyme to insoluble and high-molecular-mass substrates through the binding and steric hindrance of the mAbs to an enzyme.

Invest Ophthalmol Vis Sci, 1992 Jun, 33(7), 2185 - 93
Corneal epithelial glycoproteins exhibit Pseudomonas aeruginosa pilus binding activity; Rudner XL et al.; Adherence of Pseudomonas aeruginosa to the cornea is a requisite step in the pathogenesis of bacteria-induced corneal disease . P . aeruginosa is capable of attaching to host epithelial cells by its pili, but there is little information regarding the epithelial receptors of this adhesin in the cornea . Using nitro-cellulose blotting of polyacrylamide gels of solubilized adult mouse corneal epithelium, four major proteins (molecular weights: 38, 42, 57, and 66 kD) and several minor proteins were identified that bound purified pili from strain PAK and its hyperpiliated mutant PAK/PR1 . These proteins were identified by immunoblotting either with pilus-specific monoclonal antibodies, XLR-3 and PK 3B, or using peptide PAK 128-144 (OX) . The glycosylated nature of the proteins was determined using similar gel electrophoresis of corneal epithelial proteins, blotting onto nitrocellulose, and staining the blots with lectins conjugated to either horseradish peroxidase or alkaline phosphatase . All four major pilus-binding proteins were stained with concanavalin A lectin (mannose and glucose) and either wheat germ agglutinin lectin (WGA, specific for sialic acid and N-acetylglucosamine) or succinylated WGA lectin (only N-acetylglucosamine) . Staining for peanut agglutinin lectin (galactose beta(1-3) N-acetylgalactosamine) was seen for the 42-, 57-, and 66-kD proteins . The importance of the carbohydrate portions of these corneal proteins in pili binding was confirmed by preincubation of corneal epithelial blots with periodate or pili with sialic acid, both of which abolished the pili binding . These studies indicate that corneal epithelial pilus-binding proteins are glycoproteins in nature and that sialic acid may be a constituent of these pilus-specific receptors in the adult mouse corneal epithelium.

Antimicrob Agents Chemother, 1992 Jun, 36(6), 1236 - 40
Clindamycin, erythromycin, and roxithromycin inhibit the proinflammatory interactions of Pseudomonas aeruginosa pigments with human neutrophils in vitro; Ras GJ et al.; The Pseudomonas aeruginosa-derived phenazine pigments pyocyanin and 1-hydroxyphenazine (1-hp) prime human neutrophils for enhanced, stimulus-activated release of superoxide and myeloperoxidase (MPO), respectively . In the present study, the modulatory potentials of the antimicrobial agents clindamycin, erythromycin, and roxithromycin (10 and 20 micrograms/ml) on the prooxidative interactions of pyocyanin and 1-hp (12.5 microM) with human neutrophils have been investigated . Clindamycin, erythromycin, and especially roxithromycin caused dose-related inhibition of the generation of superoxide by both untreated and pyocyanin-treated neutrophils during activation with either the synthetic chemotactic tripeptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) or the calcium ionophore A23187 . The antimicrobial agents also inhibited the generation of reactive oxidants by the MPO-H2O2-halide system during activation of both untreated and 1-hp-treated neutrophils by FMLP . These effects appeared to be due to drug-related interference with membrane-associated oxidative metabolism, since none of the antimicrobial agents inhibited the release of MPO by activated neutrophils, nor did they possess oxidant-scavenging properties . These data demonstrate that clindamycin, erythromycin, and especially roxithromycin antagonize the proinflammatory interactions of pyocyanin and 1-hp with neutrophils and indicate a possible therapeutic role for these antimicrobial agents in the prevention of tissue damage in diseases characterized by P . aeruginosa infection.

J Gen Microbiol, 1992 Jun, 138 ( Pt 6), 1097 - 107
Physical and genetic mapping of the catA region of Pseudomonas aeruginosa; Zhang C et al.; A prime plasmid has been used as the basis for the construction of a physical and genetic map of a 125 kb segment of the Pseudomonas aeruginosa PAO chromosome . Using pMO1811, a prime plasmid selected for the catA region, a series of Tn5 insertions were obtained which identified two new markers gcu (glycine utilization) and oap (organic acids and alcohols permeability) in the 125 kb region and located them in relation to other known markers of this region . A cosmid bank was constructed from the prime plasmid and an ordered array of cosmid clones for this region identified by restriction endonuclease mapping with EcoRI, HindIII and KpnI, as well as complementation mapping and chromosome walking . By Southern hybridization analyses, it was confirmed that the chromosomal insert carried by pMO1811 was flanked by single, tandemly arranged copies of IS21 and the orientation of the insert on this prime was determined . This cosmid bank provides a resource for the further analysis of this region of the P . aeruginosa genome.

J Bacteriol, 1992 Jun, 174(11), 3514 - 21
Identification of pilR, which encodes a transcriptional activator of the Pseudomonas aeruginosa pilin gene; Ishimoto KS et al.; Two regulatory mutants of Pseudomonas aeruginosa, R1 and RA, that affect transcription of the pilin gene were isolated . This was done by introducing a plasmid carrying a fusion of the pilin gene's promoter with the lacZ gene into a bank of P . aeruginosa DNA mutagenized with the transposon Tn5G . The block in pilin expression in these mutants was shown to be at the level of transcription, since these mutants did not synthesize either pilin mRNA or pilin antigen . A restriction fragment derived from the R1 mutant that contains the entire transposon plus flanking chromosomal DNA was cloned and used as a probe to screen a cosmid library of P . aeruginosa DNA . Cosmids that could complement the pilin expression defect in both R1 and RA were isolated . The gene inactivated in R1 was sequenced . This gene, designated pilR, encodes an approximately 50-kDa polypeptide which exhibits significant similarity to the NtrC family of response regulators of the two-component regulatory system . PilR contains the amino-terminal aspartic acid residues which are conserved among the response regulators, suggesting that pilin gene transcription is regulated via a phosphotransfer mechanism in which PilR is phosphorylated by an as yet unidentified protein kinase.

Infect Immun, 1992 Jun, 60(6), 2536 - 40
Leukotriene B4 omega-oxidation by human polymorphonuclear leukocytes is inhibited by pyocyanin, a phenazine derivative produced by Pseudomonas aeruginosa; Muller M et al.; Human polymorphonuclear leukocytes (PMNL) metabolize the potent chemotaxin leukotriene B4 (LTB4) by omega-oxidation to 20-hydroxyl-LTB4 and 20-carboxy-LTB4 . The ability of unstimulated human PMNL to metabolize exogenous LTB4 was found to be inhibited by pyocyanin, a phenazine derivative produced by Pseudomonas aeruginosa, in a dose-dependent manner . 1-Hydroxyphenazine (1-OHP), a metabolite of pyocyanin, was not inhibitory under identical conditions . The initial enzymic step in the conversion of LTB4 is catalyzed by an NADPH-dependent cytochrome, P-450 . Reduction of the phenazine derivatives by NADPH was measured spectrophotometrically . Pyocyanin was reduced by NADPH in vitro in a pH-dependent manner, while 1-OHP was poorly or negligibly reduced under similar conditions . Formation of NADP+ was 20.3 +/- 1.8 nmol min-1 for pyocyanin (10 microM) at pH 5.5, compared with 0.6 +/- 0.2 nmol min-1 for 1-OHP (10 microM), while at pH 7.5 a value of 2.2 +/- 1.3 nmol min-1 was obtained for pyocyanin, with no detectable activity for 1-OHP . This indicates that inhibition of LTB4 omega-hydroxylase activity by pyocyanin might be achieved by competition for NADPH . Incorporation of exogenous 5-hydroxyeicosatetraenoic acid by PMNL into lipid pools was not affected by either phenazine derivative . The ability of bacterial pyocyanin to limit the omega-oxidation of LTB4 may have important implications for PMNL LTB4 receptor status and chemotaxis in vivo.

Biochim Biophys Acta, 1992 May 22, 1121(1-2), 8 - 15
Hydrogen exchange in Pseudomonas cytochrome c-551; Timkovich R et al.; Hydrogen exchange rates were measured or estimated for 75 amide protons in in ferrocytochrome c-551 from Pseudomonas aeruginosa (82 residues total) at neutral pH and 300 K . Rate constants span at least eight orders of magnitude . Rate constants or limiting estimates were determined by a combination of methods relying upon 1H-NMR spectroscopy, including the direct observation in one- or two-dimensional spectra of the decrease in proton intensity for samples dissolved in deuterium oxide, or, in a few favorable cases, saturation transfer from the solvent protic water . The heme ligand residues and the thioether bridge residues were slowly exchanging backbone amides, but the slowest exchanging backbone amides were found in two clusters . One was composed of Ile-48 and Lys-49 in the last turn of what is termed the 40's helix in the protein . The second was composed of Leu-74, Ala-75, Lys-76 and Val-78 in the C-terminal alpha helix.

Eur J Clin Chem Clin Biochem, 1992 May, 30(5), 285 - 90
Comparison of four procedures for measuring elastase production by Pseudomonas aeruginosa strains from cystic fibrosis patients; Saulnier J et al.; Forty-five Pseudomonas aeruginosa strains were isolated from the sputa of cystic fibrosis patients . The elastase production of each strain was assayed in the culture supernatant using four different procedures, i.e . two immunological assays (RIA and ELISA), and two enzymatic assays, the latter employing either elastin or tetraalanine as substrate, with conductometric measurement of substrate hydrolysis . Elastase concentrations were determined from standard curves prepared with the same purified elastase, and expressed in mg of elastase per litre of supernatant . The resulting values were in the range reported in the literature, and differed greatly from one strain to another (0-230 mg/l) . Linear relationships were found when assays were compared in pairs . Significant correlation coefficients were obtained (r greater than 0.76, p less than 0.001) but the values were quite different for different assays . Thus, ELISA measurements were always from three to five times higher, and RIA results were from two to five times lower, than those from the other assays . Enzymatic assays with elastin gave higher values than those using tetraalanine . Most P . aeruginosa strains produce two other proteinases, alkaline proteinase and Las A protein . Both enzymes have limited elastolytic and peptidasic activities . The presence of alkaline proteinase does not result in falsely elevated elastase values, but an increase of elastase activity was observed when Las A was preincubated with elastin . Since this increase was not observed when tetraalanine was used as the substrate, the presence of Las A in the supernatants could explain the differences observed between the enzymatic assays . The assay with the synthetic substrate is therefore preferred.

J Antimicrob Chemother, 1992 May, 29(5), 509 - 18
Antibacterial properties of SCE-2787, a new cephem antibiotic; Nakao M et al.; The in-vitro antibacterial properties of SCE-2787, a new semi-synthetic parenteral cephalosporin, were evaluated by comparing its affinities for penicillin-binding proteins (PBPs), its bactericidal activity and its effects on morphology with those of ceftazidime, cefpirome and E-1040 . SCE-2787 and cefpirome had higher affinities for PBPs 1 and 2 of Staphylococcus aureus, and a more potent anti-staphylococcal activity, than ceftazidime and E-1040 . All four antibiotics had similar activity against Escherichia coli, and showed similar affinities for PBP 3 of this organism . SCE-2787, ceftazidime and E-1040 were more potent than cefpirome against Pseudomonas aeruginosa, and showed higher affinities for the P . aeruginosa PBP 3 . The wide-spectrum antibacterial activity of SCE-2787 can be explained, in general, by its high affinities for PBPs, SCE-2787, at half its MIC level or higher, was bactericidal against all the bacterial strains examined, as were the other antibiotics tested . Exposure of S . aureus to SCE-2787 resulted in the formation of cell walls with irregular septa which subsequently thickened and collapsed . Elongation was the major morphological change of E . coli and P . aeruginosa cells treated with SCE-2787 . E . coli cells were converted to 'ghosts', infrequent in P . aeruginosa, after prolonged incubation with higher concentrations of SCE-2787.

J Antibiot (Tokyo), 1992 May, 45(5), 709 - 20
Studies on condensed-heterocyclic azolium cephalosporins . IV . Synthesis and antibacterial activity of 7 beta-{2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)- alkoxyiminoacetamido}-3-(condensed-heterocyclic azolium)methyl cephalosporins including SCE-2787; Miyake A et al.; The synthesis and in vitro antibacterial activity of 7 beta-{2-(5-amino-1,2,4-thiadiazol-3-yl)-2(Z)-alkoxyiminoacetami do} cephalosporins bearing various condensed-heterocyclic azolium groups at the 3 position in the cephalosporin nucleus are described . The thiadiazolyl cephalosporins showed good antibacterial activity against both Gram-positive and Gram-negative bacteria and the MICs of the thiadiazolyl cephalosporins against Pseudomonas aeruginosa was more potent than that of the corresponding 7 beta-{2-(2-aminothiazol-4-yl)-2(Z)-alkoxyiminoacetamido}-3- (condensed-heterocyclic azolium)methyl cephalosporins . Also, the thiadiazolyl cephalosporins bearing (imidazo{1,2-b}-pyridazinium-1-yl)methyl groups at the 3 position showed antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) . Among the cephalosporins tested, 7 beta-{2-(5- amino-1,2,4-thiadiazol-3-yl)-2(Z)-methoxyiminoacetamido}-3-(imidaz o{1,2- b}pyridazinium-1-yl)methyl-3- cephem-4-carboxylate (4, SCE-2787) which exhibited the most potent antibacterial activity and the broadest antibacterial spectrum was selected as a parenteral cephalosporin candidate for further biological evaluation.

FEMS Microbiol Lett, 1992 May 1, 71(3), 243 - 6
Auxotrophy of Pseudomonas aeruginosa in cystic fibrosis; Taylor RF et al.; Seventy-four of 403 (18.4%) sputum isolates of Pseudomonas aeruginosa from 49 of 136 (36.0%) adults with cystic fibrosis (CF) were auxotrophic mutants . Two of 11 (18.2%) isolates of P . aeruginosa taken from patients with non-CF bronchiectasis were also auxotrophic . All 99 strains taken from non-bronchiectatic sources were prototrophic . Forty-six of 55 (83.6%) CF auxotrophs required one or more of 36 growth factors tested; the requirements for the remaining 9 isolates were not identified . Methionine was the sole factor required by 17 of 22 (77.3%) isolated which depended on a single factor . We conclude that auxotrophy is a feature of P . aeruginosa infection in cystic fibrosis.

Appl Environ Microbiol, 1992 May, 58(5), 1440 - 6
Pathovar-specific requirement for the Pseudomonas syringae lemA gene in disease lesion formation; Rich JJ et al.; The lemA gene is conserved among strains and pathovars of Pseudomonas syringae . In P . syringae pv . syringae B728a, a causal agent of bacterial brown spot disese of bean, the lemA gene is required for lesion formation on leaves and pods . Using lemA-containing DNA as a probe, we determined that 80 P . syringae pv . syringae strains isolated from bean leaves could be grouped into seven classes based on restriction fragment length polymorphism . Marker exchange mutagenesis showed that the lemA gene was required for lesion formation by representative strains from each restriction fragment length polymorphism class . Hybridization to the lemA locus was detected within six different P . syringae pathovars and within Pseudomonas aeruginosa . Interestingly, a lemA homolog was present and functional within the nonpathogenic strain P . syringae Cit7 . We cloned a lemA homolog from a genomic library of P . syringae pv . phaseolicola NPS3121, a causal agent of halo blight of bean, that restored lesion formation to a P . syringae pv . syringae lemA mutant . However, a lemA mutant P . syringae pv . phaseolicola strain retained the ability to produce halo blight disease symptoms on bean plants . Therefore, the lemA gene played an essential role in disease lesion formation by P . syringae pv . syringae isolates, but was not required for pathogenicity of a P . syringae pv . phaseolicola strain.

Nippon Jibiinkoka Gakkai Kaiho, 1992 May, 95(5), 726 - 31
{The quantitation of Pseudomonas aeruginosa elastase in suppurative chronic otitis media using a sensitive ELISA method}; Suzumura H et al.; A sensitive sandwich ELISA method has been developed in order to quantitate the Pseudomonas aeruginosa elastase (PE) of ear discharge from chronic suppurative otitis media (CSOM) patients . Samples were incubated with EDTA-2Na before ELISA in order to inhibit the PE activity which hydrolyzes anti-PE IgG antibody into smaller molecular fragments . Quantitation of PE in middle ear effusions (MEE) from 10 patients with chronic otitis media with effusion (OME) were also performed . In CSOM, 12 of 14 samples revealed a significant amount of PE from 0.6 microliter/ml to 62.1 microliters/ml, which was significantly higher than those in MEE (p less than 0.05) . In MEE, 8 of 10 samples were under the detection limit . Two samples in CSOM with Pseudomonas aeruginosa infection had high levels of PE . The quantitation was linear, with a concentration from 5 ng PE/sample to 500 ng PE/sample . This ELISA system is a sensitive method for quantitation of PE requiring only very small samples.

J Appl Physiol, 1992 May, 72(5), 1927 - 33
Aerosolized Pseudomonas elastase and lung fluid balance in anesthetized sheep; Peterson BT et al.; The role of the lung epithelium in lung fluid balance was studied by ventilating anesthetized sheep with an aerosol of 20 mg of elastase from Pseudomonas aeruginosa (Ps . elastase) to increase lung epithelial permeability without affecting lung endothelial permeability or lung vascular pressures . Ps . elastase had no effect on the lung vascular pressures, the alveolar-arterial PO2 gradient (A-aPO2), the flow or protein concentration of the lung lymph, or the postmortem water volume of the lungs . The morphological alveolar flooding score in these sheep was 2.5 times the control level, but this was only marginally significant . Elevation of the left atrial pressure by 20 cmH2O alone increased the postmortem lung water volume but had no effect on A-aPO2, the alveolar flooding score, or the lung epithelial permeability assessed by the clearance of 99mTc-labeled human serum albumin . Addition of aerosolized Ps . elastase to these sheep had no effect on the total lung water volume, but it caused a redistribution of water into the air spaces, as evidenced by significant increases in the alveolar flooding score and A-aPO2 (P less than 0.01) . Elevation of the left atrial pressure by 40 cmH2O without elastase caused the same response as elevation of the left atrial pressure by 20 cmH2O with elastase, except the higher pressure caused a greater increase in the total lung water volume . We conclude that alteration of the integrity of the lung epithelium with aerosolized Ps . elastase causes a redistribution of lung water into the alveoli without affecting the total lung water volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Ann Pharmacother, 1992 May, 26(5), 639 - 41
Successful use of higher-than-recommended dosage of imipenem in Pseudomonas aeruginosa endocarditis; King JH et al.; OBJECTIVE: To report a case of Pseudomonas aeruginosa endocarditis that was successfully treated with high-dose imipenem/cilastatin and to discuss dosage modification based on individual pharmacokinetic parameters . DATA SOURCES: Clinical studies, review articles, and relevant laboratory and pharmacokinetic information . CASE SUMMARY: A 27-year-old man with right-sided P . aeruginosa endocarditis was successfully treated with long-term imipenem/cilastatin and tobramycin . The imipenem dose required to achieve therapeutic serum concentrations and cidal activity was 6 g/d . The manufacturer's recommended maximum dose is 4.0 g/d or 50 mg/kg/d . Because of the patient's large apparent volume of distribution, low serum imipenem concentrations, and lack of serum cidal activity, the clinical decision was made to increase the dose to 6 g/d or 54 mg/kg/d . Treatment was tolerated for seven weeks without any adverse effects . The patient remains free of symptoms 24 months after the diagnosis . CONCLUSIONS: Careful and discriminate use of larger-than-recommended doses of imipenem may be indicated in certain clinical situations . Dosage may need to be adjusted to body size in order to obtain optimal serum concentrations and activity.

Mol Microbiol, 1992 May, 6(9), 1195 - 204
Allelic exchange in Pseudomonas aeruginosa using novel ColE1-type vectors and a family of cassettes containing a portable oriT and the counter-selectable Bacillus subtilis sacB marker; Schweizer HP; An improved method for allele replacement in Pseudomonas aeruginosa was developed . The two main ingredients of the method are: (i) novel ColE1-type cloning vectors derived from pBR322 and pUC19; and (ii) a family of cassettes containing a portable oriT, the sacB gene from Bacillus subtilis as a counter-selectable marker, and a chloramphenicol-resistance gene allowing positive selection of both oriT and sacB . Introduction of plasmid-borne DNA into the chromosome was achieved in several steps . The DNA to be exchanged was first cloned into the new ColE1-type vectors . After insertion of the oriT and sacB sequences, these plasmid were conjugally transferred into P . aeruginosa and plasmid integrants were selected . Plating on sucrose-containing medium allowed positive selection for both plasmid excision and curing since Pseudomonas aeruginosa strains containing the sacB gene in single- or multiple copy were highly sensitive to 5% sucrose in rich medium . This procedure was successfully used to introduce an agmR mutation into P . aeruginosa wild-type strain PAO1 and should allow the exchange of any DNA segment into any non-essential regions of the P . aeruginosa chromosome.

Mol Microbiol, 1992 May, 6(9), 1155 - 62
Further studies on Pseudomonas aeruginosa LasA: analysis of specificity; Peters JE et al.; Full elastolytic activity in Pseudomonas aeruginosa is a result of the combined activities of elastase, alkaline proteinase, and the lasA gene product, LasA . The results of this study demonstrate that an active fragment of the LasA protein which is isolated from the culture supernatant fraction is capable of degrading elastin in the absence of elastase, thus showing that LasA is a second elastase produced by this organism . In addition, it is shown that LasA-mediated enhancement of elastolysis results from the separate activities of LasA and elastase upon elastin . The LasA protein does not affect the secretion or activation of a proelastase as previously proposed in other studies . Furthermore, LasA has specific proteolytic capability, as demonstrated by its ability to cleave beta-casein . Preliminary analysis of beta-casein cleavage in the presence of various protease inhibitors suggests that LasA may be classified as a modified serine protease.

Mol Microbiol, 1992 May, 6(9), 1121 - 31
Protein secretion in Pseudomonas aeruginosa: characterization of seven xcp genes and processing of secretory apparatus components by prepilin peptidase; Bally M et al.; The xcp genes are required for the secretion of most extracellular proteins by Pseudomonas aeruginosa . The products of these genes are essential for the transport of exoproteins across the outer membrane after they have reached the periplasm via a signal sequence-dependent pathway . To date, analysis of three xcp genes has suggested the conservation of this secretion pathway in many Gram-negative bacteria . Furthermore, the xcpA gene was shown to be identical to pilD, which encodes a peptidase involved in the processing of fimbrial (pili) subunits, suggesting a connection between pili biogenesis and protein secretion . Here the nucleotide sequences of seven other xcp genes, designated xcpR to -X, are presented . The N-termini of four of the encoded Xcp proteins display similarity to the N-termini of type IV pili, suggesting that XcpA is involved in the processing of these Xcp proteins . This could indeed be demonstrated in vivo . Furthermore, two other proteins, XcpR and XcpS, show similarity to the PilB and PilC proteins required for fimbriae assembly . Since XcpR and PilB display a canonical nucleotide-binding site, ATP hydrolysis may provide energy for both systems.

Exp Parasitol, 1992 May, 74(3), 340 - 7
Schistosoma mansoni: stage-dependent formation and repair of membrane pores induced by a cytotoxin from Pseudomonas aeruginosa; Breternitz R et al.; Various stages of Schistosoma mansoni were treated with a cytotoxin from Pseudomonas aeruginosa and their response to the damaging effect was studied in detail . Marker release and membrane potential measurements showed that the cytotoxin formed stable pores in all developmental stages . However, in juvenile 27-day-old worms, which are refractory to the killing effect of the cytotoxin, the pores had a smaller functional diameter as compared to other stages including 31-day-old worms . Furthermore, these resistant 27-day-old worms, but not susceptible older juvenile worms were able to repair the membrane lesions as shown by restoration of the resting membrane potential . In contrast, older juvenile and adult parasites were unable to cope with the breakdown of the resting potential induced by the cytotoxin . The results demonstrate the existence in 27-day-old schistosomes of effective repair mechanisms dealing with damage to the surface membrane.

Eur J Biochem, 1992 May 1, 205(3), 1123 - 9
Characterization and crystal structure of zinc azurin, a by-product of heterologous expression in Escherichia coli of Pseudomonas aeruginosa copper azurin; Nar H et al.; Azurin*, a by-product of heterologous expression of the gene encoding the blue copper protein azurin from Pseudomonas aeruginosa in Escherichia coli, was characterized by chemical analysis and electrospray ionization mass spectrometry, and its structure determined by X-ray crystallography . It was shown that azurin* is native azurin with its copper atom replaced by zinc in the metal binding site . Zinc is probably incorporated in the apo-protein after its expression and transport into the periplasm . Holo-azurin can be reconstituted from azurin* by prolonged exposure of the protein to high copper ion concentrations or unfolding of the protein and refolding in the presence of copper ions . An X-ray crystallographic analysis of azurin* at 0.21-nm resolution revealed that the overall structure of azurin is not perturbed by the metal exchange . However, the geometry of the co-ordination sphere changes from trigonal bipyramidal in the case of copper azurin to distorted tetrahedral for the zinc protein . The copper ligand Met121 is no longer co-ordinated to zinc which adopts a position close to the carbonyl oxygen atom from residue Gly45 . The polypeptide structure surrounding the metal site undergoes moderate reorganization upon zinc binding . The largest displacement observed is for the carbonyl oxygen from residue Gly45, which is involved in copper and zinc binding . It moves by 0.03 nm towards the zinc, thereby reducing its distance to the metal from 0.29 nm in the copper protein to 0.23 nm in the derivative.

Ann Otol Rhinol Laryngol, 1992 May, 101(5), 437 - 44
Inner ear damage and passage through the round window membrane of Pseudomonas aeruginosa exotoxin A in a chinchilla model; Lundman L et al.; By the use of computer-assisted morphometric analysis of the organ of Corti and/or measurements of action potential threshold changes, inner ear changes in chinchillas were evaluated 4 weeks after application on the round window membrane of a Pseudomonas aeruginosa exotoxin A solution . Severe inner ear damage was detected after application of 50 ng (5 microL at a concentration of 10 micrograms/mL) exotoxin A, whereas application of 5 ng exotoxin did not cause measurable inner ear damage . Perilymph concentrations of exotoxin A were measured with an enzyme-linked immunosorbent assay 1.5 to 19 hours after 50 ng, 0.5 micrograms, or 5 micrograms of exotoxin A was applied on the round window membrane . Only the highest concentration produced measurable levels of exotoxin in the inner ear fluids . It is concluded that exotoxin A present on the round window membrane of the chinchilla has the ability to penetrate into the inner ear and cause irreversible inner ear changes.

Infect Immun, 1992 May, 60(5), 1834 - 9
Safety, immunogenicity, and efficacy of a Plasmodium falciparum vaccine comprising a circumsporozoite protein repeat region peptide conjugated to Pseudomonas aeruginosa toxin A; Fries LF et al.; Twenty-one malaria-naive volunteers were immunized with a vaccine consisting of a 22-kDa recombinant peptide (R32LR), derived from the repeat region of Plasmodium falciparum circumsporozoite (CS) protein, covalently coupled to detoxified Pseudomonas aeruginosa toxin A . Nineteen volunteers received a second dose of vaccine at 8 weeks, and eighteen received a third dose at 8 to 12 months . The vaccine was well tolerated, with only one volunteer developing local discomfort and induration at the site of injection which limited function for 48 h . The geometric mean anti-CS immunoglobulin G antibody concentration 2 weeks after the second dose of vaccine was 10.6 micrograms/ml (standard deviation = 3.0 micrograms/ml) . Eleven volunteers (52%) developed anti-CS antibody levels of greater than 9.8 micrograms/ml, the level measured in the one volunteer protected against P . falciparum challenge after immunization with the alum-adjuvanted recombinant protein R32tet32 in a prior study . Three separate experimental challenges were conducted with 10 volunteers 2 to 4 weeks after the third dose of vaccine . The four best responders, on the basis of antibody levels (6 to 26 micrograms/ml), were challenged with two infected-mosquito bites, but only one of four immunized volunteers and one of three malaria-naive controls became parasitemic . In a second challenge study using five infected-mosquito bites as the challenge dose, three of three malaria-naive control volunteers and two of three immunized volunteers developed malaria . The third vaccine was apparently completely protected . In the third and last challenge, three of three controls and five of five vaccinees became infected . Sera obtained on the days of challenge inhibited sporozoite invasion of hepatocytes variably in vitro (range, 45 to 90% inhibition), but the degree of inhibition did not correlate with protection . Although antibody against the CS repeat region may protect some individuals against experimental challenge, this protection cannot be predicted from antibody levels by current in vitro assays . The functionality and fine specificity of anti-CS antibody are probably critical determinants.

Infect Immun, 1992 May, 60(5), 1779 - 85
Bacterial metabolism of human polymorphonuclear leukocyte-derived arachidonic acid; Sorrell TC et al.; Evidence for transcellular bacterial metabolism of phagocyte-derived arachidonic acid was sought by exposing human blood polymorphonuclear leukocytes, prelabelled with {3H}arachidonic acid, to opsonized, stationary-phase Pseudomonas aeruginosa (bacteria-to-phagocyte ratio of 50:1) for 90 min at 37 degrees C . Control leukocytes were stimulated with the calcium ionophore A23187 (5 microM) for 5 min . Radiochromatograms of arachidonic acid metabolites, extracted from A23187-stimulated cultures and then separated by reverse-phase high-performance liquid chromatography, revealed leukotriene B4, its omega-oxidation products, and 5-hydroxy-eicosatetraenoic acid . In contrast, two major metabolite peaks, distinct from known polymorphonuclear leukocyte arachidonic acid products by high-performance liquid chromatography or by thin-layer chromatography, were identified in cultures of P . aeruginosa with {3H}arachidonic acid-labelled polymorphonuclear leukocytes . Respective chromatographic characteristics of these novel products were identical to those of two major metabolite peaks produced by incubation of stationary-phase P . aeruginosa with {3H}arachidonic acid . Production of the metabolites was dependent upon pseudomonal viability . UV spectral data were consistent with a conjugated diene structure . Metabolism of arachidonic acid by P . aeruginosa was not influenced by the presence of catalase, superoxide dismutase, nordihydroguaiaretic acid, ethanol, dimethyl sulfoxide, or ferrous ions but was inhibited by carbon monoxide, ketoconazole, and 1,2-epoxy-3,3,3-trichloropropane . Our data suggest that pseudomonal metabolism of polymorphonuclear leukocyte-derived arachidonic acid occurs during phagocytosis, probably by enzymatic epoxidation and hydroxylation via an oxygenase . By this means, potential proinflammatory effects of arachidonic acid or its metabolites may be modulated by P . aeruginosa at sites of infection in vivo.

Photochem Photobiol, 1992 May, 55(5), 671 - 6
Room-temperature phosphorescence from azurin derivatives . Phosphorescence quenching in oxidized native azurin; Klemens FK et al.; The tryptophan phosphorescence from a series of derivatives of Pseudomonas aeruginosa azurin has been monitored at 30 degrees C in pH 8.5 buffer solution . The phosphorescence lifetimes fall in the range of 230-270 ms for deoxygenated solutions of derivatives containing Cd(II), Cu(I), Co(II), Ni(II), Hg(II) or apoazurin . A weak signal with a lifetime of ca 130 ms is observed from solutions of oxidized native azurin, but this component is ascribed to a modified form of azurin in solution, i.e . protein heterogeneity, on the basis of the unique sensitivity to quenching by dioxygen . Aside from this minor component, the tryptophan phosphorescence in the Cu(II) protein appears to be fully quenched . The quenching is assigned an electron-transfer mechanism involving transient reduction of the metal center . The same mechanism is deemed to be responsible for fluorescence quenching in oxidized native azurin as well . These observations are of interest because aromatic groups like tryptophan may be conduits for physiological electron-transfer processes involving the copper center.

Antimicrob Agents Chemother, 1992 May, 36(5), 1057 - 61
A pleiotropic, posttherapy, enoxacin-resistant mutant of Pseudomonas aeruginosa; Piddock LJ et al.; An enoxacin-resistant Pseudomonas aeruginosa mutant (G49) isolated during patient therapy was characterized in detail . The G49 mutant was cross resistant to several classes of antibiotics including quinolones, beta-lactams, chloramphenicol, and tetracycline, but not imipenem or aminoglycosides . Compared with its paired pretherapy isolate G48, this mutant had several alterations in outer membrane proteins including a complete loss of the major porin protein OprF and a substantially altered lipopolysaccharide profile . Revertants were selected at a frequency of approximately 1% after enrichment for OprF+ cells on low-salt proteose peptone no . 2 medium . Ninety-seven of these OprF+ revertants were as susceptible to carbenicillin and norfloxacin as the pretherapy isolate . One of these revertants was characterized in more detail and shown to be indistinguishable in all properties from the pretherapy isolate . It is proposed that the multiple-antibiotic-resistance (Mar) phenotype of this mutant resulted from a single pleiotropic mutation.

Nippon Rinsho, 1992 May, 50(5), 1157 - 62
{Methicillin resistant Staphylococcus aureus (MRSA) infection in geriatric hospital--management for infected decubital ulcer}; Inamatsu T et al.; Wide spread of MRSA infection in geriatric hospitals indicated two important problems which must be resolved . One is how we can eradicate MRSA in the elderly, and the other is how we can control cross infections of MRSA within the hospital . The presence of infected decubital ulcers in the elderly make it difficult to answer these problems . Usually, MRSA and Pseudomonas aeruginosa which is isolated from decubital ulcers act as colonizers on the surface of granulated wounds but do not contribute to clinical symptoms . However, these colonizers can be the source of cross infection toward other debilitated patients . The actual management for decubital ulcer infected by MRSA are discussed from the above viewpoints.

Indian J Med Res, 1992 May, 95, 136 - 8
Comparative efficacy of fluoroquinolones, aminoglycosides, ureidopenicillins & newer cephalosporins against Pseudomonas species; Paul K et al.; A total of 74 strains of Pseudomonas aeruginosa and 18 strains of Ps . putrefaciens were tested for sensitivity to 14 different antimicrobial agents . Ps . aeruginosa were mostly sensitive to netilmicin (81%), piperacillin (78%), amikacin (73%), azlocillin (70%), ceftazidime (69%) and pefloxacin (65%) . Only 66 per cent strains of Ps . putrefaciens were sensitive to netilmicin, ceftazidime and ceftriaxone . The MIC values of the different drugs for the sensitive strains were comparable with the results of susceptibility testing . The Ps . putrefaciens strains showed greater resistance than Ps . aeruginosa.

Intern Med, 1992 May, 31(5), 575 - 82
Analysis of IgA antibody to Pseudomonas aeruginosa in sera and sputa of patients with chronic airway diseases; Noda Y et al.; The change of IgA system for Pseudomonas infection was examined by enzyme-linked immunosorbent assay of the system in sera and sputa of patients with chronic airway diseases . The anti-Pseudomonas total IgA antibody titers in both sera and sputa were not elevated in group I with no infection (mainly chronic bronchitis) and group II infected with bacteria other than Pseudomonas, but were elevated in group III colonized transiently with Pseudomonas {diffuse panbronchiolitis (DPB) and bronchiectasis} and group IV colonized persistently with Pseudomonas (mainly DPB) . The elevation in the sera and sputa were mainly due to monomeric IgA and polymeric IgA (S-IgA), respectively, and values were significantly higher in group III than in group IV only in the sera . These results indicate that the IgA system is enhanced in advanced DPB and bronchiectasis complicated by Pseudomonas infection, and that the anti-Pseudomonas IgA antibody titer in serum is more useful than that in sputum for the diagnosis of respiratory Pseudomonas infection.

Antonie Van Leeuwenhoek, 1992 May, 61(4), 333 - 7
Plasmid-determined resistance to arsenic and antimony in Pseudomonas aeruginosa; Cervantes C et al.; Resistance to arsenic salts in a Pseudomonas aeruginosa clinical isolate was shown to be determined by a 100 kb transferable plasmid . The resistance pattern included arsenate, arsenite, and antimonate ions . Arsenate and arsenite resistances were inducible by previous exposure of cultures to subinhibitory amounts of either of the two ions . Phosphate ions protected P . aeruginosa cells from the toxic effects of arsenate but did not alter arsenite toxicity.

Pathol Biol (Paris), 1992 May, 40(5), 573 - 82
{Resistance to antibiotic treatment produced in a model of experimental Pseudomonas aeruginosa peritonitis}; Froidefond S et al.; A mouse model of experimental Pseudomonas aeruginosa peritonitis was used to evaluate the emergence of resistant mutants during antimicrobial therapy . Mice were infected intraperitoneally with a large inoculum (10(8) CFU + 125 mg talcum) of one of eight strains of Pseudomonas aeruginosa and treated for eight hours with imipenem (IPM) (2 mg/kg/60 min), ciprofloxacin (CIP) (5 mg/kg/45 min), ceftazidime (CAZ) (2 mg/kg/45 min), and amikacin (AN) (2 mg/kg/45 min), alone or in combination . Dosages were selected to achieve and maintain for 8 hours intraperitoneal concentrations similar to those seen in human bronchial secretions . Emergence of resistant strains occurred in 88% of mice after IPM, 29% after CIP, and 31% after CAZ . MICs for resistant strains were increased 8-fold to 512-fold above baseline . Given in combination, IPM and CIP use was followed with lower rates of resistance to each drug (6% and 2% respectively) than use of each antimicrobial alone (p less than 0.001) . Combination with amikacin reduced resistance rates for all the antimicrobials studied . No resistant strains occurred with the CIP-CAZ combination . Under the experimental conditions used, the CIP-CAZ combination provided the best results, although the difference with the CIP-IPM combination was not statistically significant.

Pathol Biol (Paris), 1992 May, 40(5), 566 - 72
{Spread in hospital units of a Pseudomonas aeruginosa phenotype producing a beta-lactamase highly inducible by clavulanic acid in vitro}; Buisson Y et al.; Pseudomonas aeruginosa strains belonging to the serogroup O:11 exhibiting susceptibility to ticarcillin (TIC) and resistance to the ticarcillin-clavulanic acid (CA) combination were found in 19 inpatients over a 14 month period . Mean inhibition diameters obtained using the agar diffusion method were 21.75 mm around the TIC disks (75 micrograms) and 15.96 mm around the TIC+CA disks (75 + 10 micrograms) . With control PaO:11 strains, these diameters were 25.27 and 25 mm, respectively . MIC for ticarcillin determined using the checkerboard method rose to 64 mg with CA levels of 16 mg/l or more . CA exhibited dose-dependent antagonism on TIC killing curves when TIC levels approximated the MIC; this effect was no longer present with higher TIC levels . In the crude bacterial extract, a betalactamase of the cephalosporinase type was detected in the absence of induction and increased threefold after exposure to cefoxitin (100 mg/l) and fourfold after exposure to CA (5 mg/l) . All these PaO:11 strains exhibited the same antimicrobial resistance phenotype with decreased susceptibility to ureidopenicillins and resistance to aminoglycosides and fluoroquinolones . The induction of a chromosome-encoded cephalosporinase by CA proved useful as an epidemiologic marker . Nosocomial spread of this phenotype was likely the result of selection due to use of antimicrobials.

Pathol Biol (Paris), 1992 May, 40(5), 433 - 9
{Pseudomonas aeruginosa and imipenem: correlation between membrane protein D2 and resistance in fifteen strains isolated from patients with mucoviscidosis}; Recule C et al.; A characteristic feature of imipenem-resistant strains of Pseudomonas aeruginosa is loss or decreased expression of the outer membrane protein (OMP) D2, whose molecular weight is 45 to 49 kDa . D2 was studied in 15 strains of P . aeruginosa with intermediate susceptibility or resistance to imipenem recovered from the sputum of 15 patients with cystic fibrosis . The OMP was extracted using Sarkosyl and separated by SDS-PAGE electrophoresis . Electrophoresis patterns were compared to those of reference strains 3B and 3C which are resistant and susceptible to imipenem, respectively . Expression of D2 was normal in three strains, weak or very weak in 11 strains and absent in one strain . For 12 strains, the alteration of the D2 protein was consistent with previous reports . However, the finding of normal D2 production in three strains is unusual and suggests the possible presence of another mechanism of resistance.

Kansenshogaku Zasshi, 1992 May, 66(5), 620 - 7
{A clinical study of bacteremia in the last fifteen years}; Wada K et al.; Between 1976 and 1990, 208 cases of bacteremia in our department were studied . Community acquired bacteremias were only 18 (8.7%) cases . Bacteremias, particularly caused by Gram positive organisms, increased significantly after 1981, compared with the first five years . It was related to the marked increase in cases of venous access devices and less sensitivity of the Gram positive organisms to the new cephem antibiotics . In the study, 144 (69.2%) cases were eradicated . Severe underlying diseases or complication of pneumonia influenced the eradication rate of bacteremia . Bacteremia caused by methicillin resistant Staphylococcus aureus or Pseudomonas aeruginosa showed poor prognosis . The average duration from onset to death, was 5.1 days . Forty cases (62.5%) died within 3 days . Among the 201 cases, leukocytosis (WBC greater than 10,000/mm3) was present in 38.3%, while leukopenia (WBC less than 1000/mm3) in 25.3% . Eradication rate between the two groups was not significant . CRP was elevated (greater than 8.5 mg/dl) in 63.5% . The prognosis of this group was significantly poor . Elevation of serum bilirubin was also related with increase of mortality . According to these results, empiric therapy before the isolation of organisms is the most important strategy for treatment of bacteremia.

J Gen Microbiol, 1992 May, 138 ( Pt 5), 879 - 87
Detection of micro-organisms in soil after in situ hybridization with rRNA-targeted, fluorescently labelled oligonucleotides; Hahn D et al.; rRNA sequences were used as targets for synthetic oligonucleotides labelled with the fluorescent dye tetramethylrhodamine isothiocyanate (Tritc) for in situ hybridizations to detect micro-organisms directly in soils that have different contents of soil minerals and organic material . Introduced Pseudomonas aeruginosa cells were directly fixed in soils and applied to slides after separation of large soil minerals only . Remaining soil minerals (clay minerals) and organic material (up to 8%) did not significantly interfere with signal expression after hybridization . Background signals were mainly caused by autofluorescence of organic material . Non-specific binding of labelled oligonucleotides to soil particles was not observed . In situ detection of introduced cells of Pseudomonas cepacia in a sandy loam spiked with a mixture of selected soil micro-organisms was possible after hybridization with a specific probe . Analysis of natural bacterial populations in soil, however, was not possible by in situ hybridization without activation of these micro-organisms by adding nutrients . Growing cells, e.g . Streptomyces scabies hyphae growing in amended soil, were easily detected.

J Antimicrob Chemother, 1992 May, 29(5), 539 - 46
Activity of antibiotics against resistant Pseudomonas aeruginosa; Fujita J et al.; The activity of 12 antibiotics, piperacillin, cefazolin, cefotiam, ceftizoxime, latamoxef, ceftazidime, cefuzonam, amikacin, ofloxacin, imipenem, aztreonam and minocycline, against 120 isolates of Pseudomonas aeruginosa was examined . In addition, the efficacy of antibiotics against single-, double-, or triple-drug-resistant isolates of P . aeruginosa were also examined to determine the cross-resistance to each drug . There was cross-resistance between piperacillin, ceftazidime and aztreonam, but amikacin and imipenem remained effective antibiotics, especially as salvage therapy, against isolates resistant to one agent . Results also suggested that piperacillin, ceftazidime or imipenem in combination with amikacin are effective combination regimens against most clinical isolates of P . aeruginosa . Amikacin and imipenem were also suitable antibiotics, especially as salvage therapy, against isolates of P . aeruginosa resistant to two agents . In conclusion, the results provide useful guidelines for choosing an effective treatment against clinical isolates of P . aeruginosa, and for choosing salvage therapy against resistant P . aeruginosa.

Eur J Clin Microbiol Infect Dis, 1992 May, 11(5), 432 - 7
Molecular epidemiological analysis of Pseudomonas aeruginosa strains causing failure of antibiotic therapy in cystic fibrosis patients; Bingen E et al.; A combination of esterase electrophoretic typing and analysis of the restriction fragment length polymorphism of ribosomal DNA regions (ribotyping) was used to compare 27 Pseudomonas aeruginosa strains isolated before and after two-week courses of anti-pseudomonal treatment in seven cystic fibrosis patients . A total of 12 courses of therapy were studied in which ciprofloxacin, ceftazidime, azlocillin or imipenem were used alone or in combination with tobramycin . Isolates at a count of greater than or equal to 10(6) cfu/ml of sputum were collected when there was evidence of therapeutic failure on the basis of persistence of isolates whether or not they were resistant to the antibiotic used for therapy . Emergence of resistance was observed in ten cases and failure to eradicate sensitive strains in five cases . Among the 27 isolates, eight zymotypes and five ribotypes were identified . With this typing approach, resistant post-therapy isolates were found to be identical to pre-therapy isolates in all cases but one . However, in one case an additional resistant strain was isolated after therapy besides that initially present . In all five cases in which susceptibility was still observed after treatment, pre-therapy and post-therapy isolates were indistinguishable . Using this molecular typing approach, all the strains were typable . Thus combination of esterase typing and ribotyping should improve the analysis of therapeutic failure in cystic fibrosis patients.

J Formos Med Assoc, 1992 May, 91(5), 531 - 7
Management of infected tibial plate osteosynthesis using a staging system for infected fractures; Ueng WN et al.; Osteomyelitis following plate osteosynthesis of a tibial shaft fracture was managed in 23 patients through a staging system and prospective treatment protocol . The staging system, which is arranged in an upstaging disease progression and downstaging treatment protocol, is composed of the status of osseous continuity (Type I to II) and the dead space created by the debridement surgery (Classes A to D) . The follow-up period ranged from 20 to 48 months (average, 31.5 months) . Staphylococcus aureus (35.5%) and Pseudomonas aeruginosa (29%) were the most commonly involved organisms . Twenty-two infections were initially arrested by one debridement, and one infection was arrested by three sequential debridements . There were seven Stage IA, one Stage IB, seven Stage IIA, two Stage IIB, three Stage IIC, and three Stage IID fractures in this study . The average number of surgical procedures were 1, 2, 2.1, 4, 4.7 and 6, respectively . The difficulty of treatment increased with the severity of the disease . The average time to bone union for Stage IIA, IIB, IIC and IID fractures were 11, 9, 20.3 and 21.5 months, respectively . A tibial osseous defect longer than 4 cm is a major prognostic factor for prolonged disability time . Important complications were nonunion one, bone graft stress fractures (two), and recurrence (three).

J Gen Microbiol, 1992 May, 138 ( Pt 5), 951 - 8
Exogenous siderophore-mediated iron uptake in Pseudomonas aeruginosa: possible involvement of porin OprF in iron translocation; Meyer JM; In addition to the two siderophores pyoverdine and pyochelin synthesized by Pseudomonas aeruginosa ATCC 15692 (strain PAO1), several siderophores produced by other bacteria or fungi, namely cepabactin, salicylic acid, desferriferrichrysin, desferriferricrocin, desferriferrioxamine B, desferriferrioxamine E and coprogen, were able to promote iron uptake with variable efficiencies into this bacterium . For most of these siderophores, these results were consistent with the growth stimulation produced by the same compounds in a plate bioassay . Desferriferrichrome A, enterobactin and desferriferrirubin, however, did not promote iron uptake, although enterobactin and desferriferrirubin stimulated bacterial growth . These paradoxical data are discussed in view of siderophore-inducible iron uptake systems, as demonstrated recently for enterobactin . Among the strains tested, including the wild-type PAO1, the pyoverdine-less mutant PAO6606 and the two porin-mutants P . aeruginosa H636 (oprF::omega) and P . aeruginosa H673 (oprD::Tn501), only for the porin-OprF mutant were fewer siderophores able to promote iron uptake compared to the other strains . Such results suggest that beside specific routes for iron uptake P . aeruginosa is also able to take up siderophore-liganded iron through OprF.

Immunology, 1992 May, 76(1), 86 - 94
Effects of mucoid and non-mucoid Pseudomonas aeruginosa isolates from cystic fibrosis patients on inflammatory mediator release from human polymorphonuclear granulocytes and rat mast cells; Friedl P et al.; Mucoid Pseudomonas aeruginosa causing chronic bronchopulmonary infection in cystic fibrosis (CF) patients may interfere with host defence mechanisms . We investigated 13 P . aeruginosa strains isolated from sputa of CF patients with regard to the induction or modulation of inflammatory mediator release from human neutrophils (PMN) and rat mast cells . The effects of mucoid as compared to non-mucoid bacteria were studied using a mucoid strain and its non-mucoid revertant . The release of leukotrienes (LT) and histamine in response to the majority of the CF strains was insignificant . However, preincubation of PMN with P . aeruginosa caused a dose-dependent decrease (50-95%) of LTB4 and LTC4 generation and LTB4 metabolism induced by the Ca(2+)-ionophore A23187 or opsonized zymosan (ZX) (P less than 0.001) . The mucoid strains caused a three- to 10-fold higher impairment of LTB4 release (P less than 0.05) and a concomitant down-regulation of LTB4 receptors on neutrophils . Inhibitory effects were also obtained for mucoid and non-mucoid bacteria when the phorbol-ester or the Ca(2+)-ionophore induced luminol enhanced chemiluminescence response (P less than 0.001) or the histamine release from rat peritoneal mast cells (P less than 0.01) was studied . The bacteria-cell contact with non-mucoid strains was associated with an increased Ca2+ influx into PMN, whereas mucoid bacteria had no effect . In addition, a protein kinase C-dependent decrease of the C3bi receptor was suppressed by the mucoid--and less effectively--by the non-mucoid strain . The results suggest that the impairment of the phagocytic and inflammatory system may contribute to the pathogenesis and persistence of mucoid P . aeruginosa infection in CF.

Biochem J, 1992 May 1, 283 ( Pt 3), 839 - 43
A quantitative model for the mechanism of action of the cytochrome c peroxidase of Pseudomonas aeruginosa; Foote N et al.; Each of the elementary reaction steps in both the activation process and catalytic cycle of the cytochrome c peroxidase of Pseudomonas aeruginosa was characterized using stopped-flow methods . A synthesis of these data led to the establishment of a quantitative model for the action of this enzyme . Comparisons were made between experimental data and calculations over a wide range of enzyme, reductant and H2O2 concentrations . Close agreement was found between empirical and simulated reaction time courses from millisecond to tens of seconds time ranges, giving us confidence in the validity of the quantitative model of this enzyme's actions.

Biochim Biophys Acta, 1992 Apr 17, 1120(3), 315 - 21
Extracellular lipase from Pseudomonas aeruginosa is an amphiphilic protein; Jaeger KE et al.; Lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) secreted by Pseudomonas aeruginosa PAC1R was purified from cell-free growth medium by preparative isoelectric focusing . After blotting the N-terminal amino acid sequence and the amino acid composition were determined and compared to P . fragi and P . cepacia lipases yielding significant homology between all three species . Additionally, a consensus sequence K-Y-P-i-v-l-V-H-G was identified residing at the N-terminus of Pseudomonas lipases and in the central part of Staphylococcus lipases . Treatment of lipase with the serine-specific inhibitor diethyl p-nitrophenyl phosphate caused a rapid and complete inhibition of enzyme activity indicating the presence of a serine at the catalytic site as expected from lipase consensus sequences . Upon charge-shift electrophoresis the electrophoretic mobility of purified lipase was shifted either anodally or cathodally in the presence of sodium deoxycholate and cetyltrimethylammoniumbromide, respectively . This result demonstrates that extracellular lipase of P . aeruginosa exhibits an amphiphilic character like intrinsic membrane proteins.

Am J Ophthalmol, 1992 Apr 15, 113(4), 418 - 23
Efficacy of tobramycin-soaked collagen shields vs tobramycin eyedrop loading dose for sustained treatment of experimental Pseudomonas aeruginosa-induced keratitis in rabbits; Assil KK et al.; We compared the efficacy of a fortified tobramycin-soaked collagen shield to the efficacy of a single loading dose (four 50-microliters drops) of fortified tobramycin eyedrops in the treatment of New Zealand White rabbits with Pseudomonas aeruginosa-induced keratitis . Eyedrop loading-dose efficacy was evaluated with and without lateral tarsorrhaphy . Six hours after a single treatment, significantly fewer Pseudomonas colonies were present in the corneas of all three drug-treated groups as compared to the number of colonies in the corneas of balanced salt solution-treated control rabbits (P less than .006) . Although no significant difference was observed between any of the drug-treated groups, lateral tarsorrhaphy was associated with a greater than tenfold decrease in the number of colony-forming units (P = .073) . We found no significant difference in efficacy between a collagen shield presoaked in tobramycin, and a single loading dose of tobramycin eyedrops, in the treatment of rabbits with P . aeruginosa-induced keratitis.

FEBS Lett, 1992 Apr 13, 301(1), 34 - 6
A dysfunctional C1 inhibitor protein with a new reactive center mutation (Arg-444-->Leu); Frangi D et al.; A P1 mutation (Arg-444-->Leu) was identified in a dysfunctional C1 inhibitor from a patient with type 2 hereditary angioneurotic edema . The mutation was defined at the level of the protein (by sequence analysis of the Pseudomonas aeruginosa elastase-derived reactive center peptide), and the mRNA (CGC-->CTC) (by sequence analysis of PCR-amplified DNA).

Klin Monatsbl Augenheilkd, 1992 Apr, 200(4), 251 - 6
{Corneal ulcer . Current analysis from specialized ambulatory care of a clinic}; Huber-Spitzy V et al.; A review of 115 cases of ulcerative keratitis that were diagnosed and treated at the specialized ambulatory care center for infectious eye diseases at the 2 . Department of Ophthalmology over a period of eight years (January 1983-April 1991) is presented . In the analysis of the etiology nearly half (47.7%) were observed following a trauma to the epithelium, 38 (= 33.0%) were associated with contact lens wear and the third largest group (10.4%) was associated with lid problems . It is apparent that over the course of the last years the spectrum of microorganisms associated with this localized inflammation has shifted: the prevalence of Staphylococci (1983-1986 = 65%) has decreased, whereas the incidence of gram-negative rods increased (1987-1990 = 49%) . In 19% Pseudomonas aeruginosa could be isolated, mostly associated with soft contact lens wear . A total of 37.5% of the staphylococci isolates were found to be resistant to gentamicin, most probably as a consequence of the widespread, indiscriminate use of this antibiotic . An updated treatment schedule is presented.

J Antimicrob Chemother, 1992 Apr, 29(4), 427 - 33
Comparison of gentamicin dosing regimens using an in-vitro model; Begg EJ et al.; An in-vitro model which simulates in-vivo pharmacokinetics was used to compare the efficacy against Pseudomonas aeruginosa of dosing regimens of gentamicin which achieve different peak/trough concentrations but use the same total dose over 24 h . First exposure to gentamicin produced a rapid bactericidal effect which was proportional to the initial peak concentration . Subsequent doses of gentamicin produced a smaller bactericidal effect . Regrowth occurred with all dosing regimens, even after very high initial concentrations (26 mg/L) . The time to reach bacterial counts above starting values was prolonged in relation to peak concentrations . Regrowth was also demonstrated in continuous infusion experiments which maintained very high concentrations (26 mg/L), although an inhibitory effect was evident compared with single dose experiments and the experiments mimicking in-vitro pharmacokinetics . There was little evidence of a post-antibiotic effect . The data supports the use of larger initial and longer interval bolus dosing compared with current recommendations.

Acta Paediatr, 1992 Apr, 81(4), 340 - 4
Home intravenous antibiotic treatment of patients with cystic fibrosis; Strandvik B et al.; We report one-year's experience of home iv antibiotic treatment in 31 patients with cystic fibrosis chronically colonized with Pseudomonas aeruginosa . The patients were aged 4-67 years and had a mild to severe disease as indicated by a Shwachman score of 46-95 (mean 77) . Ninety-two courses of iv antibiotic therapy were given (mean 3.0 per patient) . The mean duration of the courses was 15.4 days . The entire antibiotic course, except for the first dose, was administered at home in 70% of the courses . Most patients (94%) were given a combined treatment of a beta-lactam and an aminoglycoside, administered by the patients themselves or their parents . One inserted venous cannula could be used for the whole treatment period in 30% of the courses . There were no complications . The clinical and bacteriological outcome was good to excellent in 89% of the courses, with temporary eradication or semi-quantitative decrease of Pseudomonas growth in sputum . Lung function (forced expiratory volume at 1 s) and blood gases improved significantly (p less than 0.001) and p less than 0.01, respectively) . Most patients were able to attend work or school as usual, and 96% of the patients preferred this type of treatment to hospitalization . Apart from the psychosocial advantages, the economical savings were substantial . In comparison to traditional treatments in hospital (21 patients, 41 courses) home iv antibiotic treatment was safe and effective.

Neuropediatrics, 1992 Apr, 23(2), 108 - 10
Extramedullary hematopoiesis of the cranial dura and anhidrotic ectodermal dysplasia; Sitton JE et al.; A 2-year-old amerasian male with anhidrotic ectodermal dysplasia (Christ-Siemens-Touraine Syndrome) was admitted for status epilepticus and Mycobacteria avium-intracellulare infection . A computed tomography scan of the head revealed a mass thought to be a subdural hematoma . The patient died following overwhelming Mycobacteria avium-intracellular and Pseudomonas aeruginosa sepsis . Autopsy revealed extensive extramedullary hematopoiesis of the dura forming a tumor-like thickening with focal subdural hemorrhage . To our knowledge, this is the first report of extramedullary hematopoiesis of the cranial dura associated with anhidrotic ectodermal dysplasia.

Mol Microbiol, 1992 Apr, 6(7), 863 - 71
Osmoprotectants and phosphate regulate expression of phospholipase C in Pseudomonas aeruginosa; Shortridge VD et al.; Phospholipase C has been increasingly recognized as a significant virulence determinant in the pathogenesis of Gram-negative and Gram-positive infections . Pseudomonas aeruginosa carries two, non-tandem genes encoding phospholipase C (PLC) activity . One PLC (PLC-H) haemolyses human and sheep erythrocytes while the other is not haemolytic for these kinds of red blood cells . It was previously determined that the synthesis of both PLCs is regulated by inorganic phosphate (Pi), but little else was known regarding the regulation of these potentially important virulence determinants of P . aeruginosa . In this report, data are presented demonstrating that both PLC genes are regulated at the transcriptional level by Pi and by a P . aeruginosa homologue of the positive regulator of genes in the Pi regulon of Escherichia coli, i.e . PhoB . In addition to Pi, it is also shown in this report that the synthesis of both PLC-H and PLC-N is induced by compounds which are not only derived from the substrate product of both enzymes, i.e . phosphorylcholine, but are also known osmoprotectants in eukaryotic and prokaryotic cells . The osmoprotective derivatives of phosphorylcholine which induce the synthesis of PLC in P . aeruginosa include choline, glycine betaine, and dimethylglycine, but not sarcosine (monomethylglycine) or glycine . By constructing mutants which are deficient in the production of each separate PLC and in the production of PhoB it was determined that induction of PLC-H by the osmoprotective compounds is independent of Pi concentration and PhoB, while induction of PLC-N by these compounds requires Pi-deficient conditions and PhoB.(ABSTRACT TRUNCATED AT 250 WORDS)

J Am Soc Nephrol, 1992 Apr, 2(10), 1498 - 501
Pseudomonas exit site infections in continuous ambulatory peritoneal dialysis patients; Kazmi HR et al.; The purpose of this study is to examine the natural history of Pseudomonas aeruginosa exit site infections in continuous ambulatory peritoneal dialysis (CAPD) patients treated with oral ciprofloxacin and local exit site care . A retrospective view was undertaken of 18 episodes of P . aeruginosa exit site infections developing in 17 patients maintained on CAPD during 1989 and 1990 . Standardized therapy for the exit site infection consisted of oral ciprofloxacin (500 mg twice daily) and local exit site care with antiseptic agents . Fifteen (83%) of 18 of the pseudomonas exit site infections resolved with therapy . Three episodes (17%) required catheter removal to successfully eradicate the infection . Four of the 15 patients whose exit site infections resolved developed P . aeruginosa peritonitis 2 to 9 months after the clinical resolution of the exit site infection . The majority of pseudomonas exit site infections in CAPD patients can be successfully treated with oral ciprofloxacin and local care . Approximately 17% of the patients in this study required catheter removal to successfully eradicate the infection and an additional 22% of the patients developed pseudomonas peritonitis several months after the resolution of the exit site infection.

J Appl Physiol, 1992 Apr, 72(4), 1386 - 92
Pulmonary hemodynamics and tissue damage after one lung infusion of Pseudomonas aeruginosa in sheep; Loick HM et al.; The relative roles of hematogenous mediators and direct bacterial toxicity due to phagocytosis by pulmonary intravascular macrophages were determined by selective bacterial infusion into the left pulmonary artery and comparison of right and left lungs at 24 h . Chronically instrumented sheep received 15-min pulmonary arterial infusions of live Pseudomonas aeruginosa (0.35-2.9 x 10(9), n = 6) or saline (n = 5) . The saline group demonstrated stable cardiopulmonary function over time . Left lung blood flow, measured by Doppler flow probe, decreased 15 min into the bacterial infusion, with a concomitant sevenfold increase in left lung pulmonary vascular resistance index . The right lung pulmonary vascular resistance index doubled at 1 h, in association with increased plasma thromboxane B2 levels . An increase in cardiac index and decrease in systemic vascular resistance occurred at 12 h . The wet-to-dry weight ratio of the Pseudomonas-infused left lung was increased compared with that of the sham-infused lung . The tissue count of neutrophils in the lungs was doubled in both sides, but neutrophils on the left were more degranulated . The left lung tissue damage was caused by direct bacterial toxicity, including activation of phagocytic cells . Hematogenous mediators induced pulmonary and systemic hemodynamic changes and right lung neutrophil sequestration, but they did not damage the noninfused lung.

J Antibiot (Tokyo), 1992 Apr, 45(4), 485 - 99
Studies on condensed-heterocyclic azolium cephalosporins . III . Synthesis and antibacterial activity of 7 beta-{2-(2-amino-5-substituted-thiazol-4-yl)-2 (Z)-alkoxyiminoacetamido}-3-(condensed-heterocyclic azolium)methyl-3-cephem-4- carboxylates; Nishimura T et al.; As a part of our research on the synthesis of cephalosporins bearing condensed-heterocyclic azolium groups at the 3 position in the cephalosporin nucleus, we describe herein the synthesis of 7 beta-{2-(2-amino-5-halogeno-, methylthio-, methylsulfinyl-, methylsulfonyl- and sulfothiazol-4-yl)-2(Z)-alkoxyiminoacetamido} cephalosporins and their antibacterial activity . Among the compounds prepared, 7 beta-{2-(2-amino-5-chlorothiazol-4-yl)-2(Z)- methoxyiminoacetamido}-3-(imidazo{1,5-a}-pyridinium-1-yl)methyl-3-cephem -4-carboxylate (14) showed good antibacterial activity against both Staphylococcus aureus including methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, whereas the antibacterial activity against other Gram-negative bacteria was a slightly lower than that of 7 beta-{2-(2-aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido}-3-(im ida zo {1,2-a}pyridinium (I-1) and imidazo{1,5-a}pyridinium (I-4)-1-yl)methyl-3-cephem-4-carboxylates.

Mikrobiyol Bul, 1992 Apr, 26(2), 108 - 15
{Phage typing of Pseudomonas aeruginosa strains from various sources}; Kantarci G; In this study, 103 strains of P . aeruginosa, isolated from various clinical specimens were typed by phage technique with a set of 22 phages . Phage typing procedure gave 29 different phage patterns . Ninety one of 103 P . aeruginosa strains could be typed, the other 12 strains could not be typed because of they have no sensitivity against test phages, studied . As a result of this study, phage typing technique is useful for the observation of epidemiological P . aeruginosa infections, but phage patterns have got significance only for the local environments.

J Gen Microbiol, 1992 Apr, 138 ( Pt 4), 733 - 41
Specificity of the Pseudomonas aeruginosa PAO1 lipoprotein I gene as a DNA probe and PCR target region within the Pseudomonadaceae; Saint-Onge A et al.; The lipoprotein I gene (oprI) of Pseudomonas aeruginosa PAO1 was cloned and sequenced . A high degree of homology was found between our cloned PAO1 gene sequence and two published oprI sequences . Specific oligonucleotides were designed to amplify the oprI gene by the polymerase chain reaction (PCR) . The potential of either the complete gene sequence or the specific oligonucleotide primers as a tool for rapid strain identification was directly assessed against bacterial colonies by PCR or against purified genomic DNA by Southern blot analysis, using a number of representative strains within the Pseudomonadaceae . The oprI gene was found to be well conserved within RNA group I.

Clin Otolaryngol, 1992 Apr, 17(2), 150 - 4
A prospective study of otitis externa; Agius AM et al.; A prospective study of otitis externa in the district of South Bedfordshire was undertaken between October 1990 and January 1991 . Patients were referred untreated by general practitioners; self-referred patients with external otitis were also included . A detailed history was taken, the severity of the condition assessed, aural toilet performed, bacteriology swabs taken and the patient treated according to department protocol . 48 patients were included in the study; a similar number of age and sex-matched controls without otitis externa were randomly selected from the ENT outpatient clinics for comparison . Regular swimming emerged as a significant factor in the aetiology of otitis externa . The commonest organism cultured was Pseudomonas aeruginosa and this accounted for the most severe cases seen.

APMIS, 1992 Apr, 100(4), 326 - 34
Mucosal immunity to Pseudomonas aeruginosa alginate in cystic fibrosis; Pedersen SS et al.; Patients with cystic fibrosis commonly acquire chronic pulmonary infection with alginate-producing Pseudomonas aeruginosa . The infection remains localized at the mucosal surfaces of the airways . Using enzyme-linked immunosorbent assays immunoglobulin concentrations and titers of specific antibodies to purified P . aeruginosa alginate and to P . aeruginosa sonicated antigens were measured in tears, saliva, sputum and serum . CF patients had significantly higher concentrations of IgG, IgA and SIgA in serum and saliva than controls . They also had significantly higher levels of specific antibodies to alginate and sonicated antigen in secretions and serum . Local production of IgA, IgG and IgM antibodies to P . aeruginosa was demonstrated . Only a minor proportion of specific IgA antibodies were present as secretory IgA in tears, saliva and sputum . The ratio of alginate-specific SIgA to specific monomeric IgA in sputum was significantly lower than the similar ratio in saliva, whereas the same ratio for specific P . aeruginosa sonicate antigens was found in saliva and sputum.

Biochem J, 1992 Apr 1, 283 ( Pt 1), 177 - 80
Animal ferritin and bacterioferritin contain quinones; al-Massad FK et al.; The origin of the 440 nm fluorescence of horse spleen ferritin and of Pseudomonas aeruginosa and Azotobacter vinelandii bacterioferritin has been investigated using a Nitro Blue Tetrazolium/glycinate colorimetric test specific for quiones {Paz, Fluckiger, Boak, Kagan & Gallop (1991) J . Biol . Chem . 266, 689-692} . The results of the analysis indicate that ferritin and bacterioferritins contain quinones . A possible functional role of these quinones in iron uptake and release is described, as is the possibility that the presence of quinones in these proteins results from oxidative damage.

Gene, 1992 Apr 1, 113(1), 47 - 53
The Azotobacter vinelandii recA gene: sequence analysis and regulation of expression; Venkatesh TV et al.; The nucleotide (nt) sequence of the Azotobacter vinelandii recA gene (Av-recA) was determined and compared with the recA sequences from Pseudomonas aeruginosa (Pa-recA), a soil bacterium, and Escherichia coli (Ec-recA), an enteric bacterium . The Av-recA gene and the deduced aa sequence were found to be more similar to their Pa-recA counterparts than to the Ec-recA gene and protein . Expression of Av-recA was found to be autoregulatory . Unlike Ec-recA and Pa-recA, however, expression of Av-recA was weakly enhanced upon DNA damage . In E . coli, expression of an Av-recA::lacZ fusion was poor, but its autoregulation was similar to that of Ec-recA . Av-recA expression, however, could not induce the repair system response in E . coli.

Proc Natl Acad Sci U S A, 1992 Apr 1, 89(7), 2659 - 63
AlgR2 is an ATP/GTP-dependent protein kinase involved in alginate synthesis by Pseudomonas aeruginosa; Roychoudhury S et al.; The exopolysaccharide alginate is a major virulence factor in the pathogenicity of Pseudomonas aeruginosa infecting the lungs of cystic fibrosis (CF) patients . Alginate synthesis by P . aeruginosa is believed to occur in response to environmental signals present in the CF lung . Transcription of a critical alginate biosynthetic gene, algD, is triggered by environmental signals and is known to be controlled by regulatory proteins AlgR1, AlgR2, and AlgR3 . AlgR1 is a member of the family of response regulators of the phosphorylation-dependent two-component bacterial signal transduction systems . In this report, we describe the characterization of AlgR2 as the kinase involved in phosphorylation of AlgR1 . AlgR2, an 18-kDa soluble protein undergoes rapid autophosphorylation in the presence of either ATP or GTP and transfers the phosphate to AlgR1 . AlgR2 retains high affinity for both ATP and GTP with an apparent Km of 137 and 249 nM, respectively, for phosphorylation by these two substrates . ADP and GDP exhibit competitive inhibition with an apparent Ki of 94 and 314 nM, respectively, during phosphorylation by ATP and 481 and 273 nM during phosphorylation by GTP . AlgR1 and AlgR2 can be isolated in the form of an 80-kDa complex that is capable of undergoing phosphorylation and intracomplex phosphotransfer in vitro . A 16-kDa AlgR2 analog, capable of autophosphorylation in the presence of ATP or GTP and transferring the phosphate moiety to AlgR1, has been characterized in Escherichia coli.

J Bacteriol, 1992 Apr, 174(7), 2407 - 11
Common antigen lipopolysaccharide from Pseudomonas aeruginosa AK1401 as a receptor for bacteriophage A7; Rivera M et al.; A-band, a D-rhamnose-containing common lipopolysaccharide antigen isolated from Pseudomonas aeruginosa AK1401, was found to be a receptor for bacteriophage A7 . The phage-borne rhamnanase was capable of hydrolyzing the A-band to expose core-lipid A containing only two or three rhamnose repeats . Interaction of the hydrolyzed A-band with core- or lipid A-specific monoclonal antibodies revealed that common epitopes exist in the inner core and lipid A regions, while the outer core of A-band appears to be different from that of the serotype-specific (B-band) lipopolysaccharide.

Infect Immun, 1992 Apr, 60(4), 1530 - 5
Human tracheobronchial mucin: purification and binding to Pseudomonas aeruginosa; Reddy MS; Colonization of the respiratory tract with Pseudomonas aeruginosa is a serious problem in cystic fibrosis and seriously ill hospitalized patients . Human tracheobronchial mucin (HTBM), the major glycoprotein of human tracheobronchial secretions, is known to interact with this pathogen, which may then be cleared by mucociliary action . However, the mechanism of interaction is not known . To understand this process, pure HTBM was isolated from tracheobronchial secretions of a laryngectomee . Following initial fractionation on Sepharose CL-2B, the HTBM-containing fraction was subjected to reductive methylation and then gel filtration . Pure HTBM was employed in an overlay binding assay to identify the bacterial adhesin(s) and mucin receptors that participate in mucin-P . aeruginosa interactions . An approximately 16-kDa nonpilus protein component(s) of P . aeruginosa was found to be the adhesin(s) for HTBM . The mucin receptor for the 16-kDa component(s) was found in the peptide moiety . This study confirms that P . aeruginosa utilizes the nonpilus adhesin(s) to bind to HTBM . Identification of the specificity of the HTBM-P . aeruginosa interactions can lead to a better understanding of the predominance of P . aeruginosa colonization in individuals with cystic fibrosis.

Infect Immun, 1992 Apr, 60(4), 1273 - 8
Lymphoproliferative activity of Pseudomonas exotoxin A is dependent on intracellular processing and is associated with the carboxyl-terminal portion; Legaard PK et al.; Pseudomonas aeruginosa exotoxin A (PE) represents a microbial superantigen that requires processing by accessory cells in order to induce the proliferation of V beta 8-bearing murine T lymphocytes . In this study, we have observed that PE requires intracellular processing by a protease in order to induce lymphoproliferation . Pepstatin A, an inhibitor of acid proteases, inhibited PE-induced lymphoproliferation, whereas leupeptin, an inhibitor of serine and thiol proteases, had no effect on PE-induced lymphoproliferation . A number of mutant forms of PE were examined for their ability to induce lymphoproliferation . The mutant form which lacks amino acids 5 to 224 of the receptor-binding domain, PE43, was capable of inducing murine thymocytes to proliferate in the presence of accessory cells . However, neither PEgly276, a mutant toxin which undergoes a different intracellular processing pattern than wild-type PE, nor PE589, a mutant toxin which lacks amino acids 590 to 613 at the carboxyl terminus, was able to induce thymocyte proliferation . In addition, the lymphoproliferation induced by the PE43 mutant form of PE could also be inhibited by pepstatin A . Therefore, our data indicate that intracellular processing by a proteolytic enzyme which is inhibited by pepstatin A is critical for PE-induced lymphoproliferation . Furthermore, the lymphoproliferative activity of PE is associated with the carboxyl-terminal portion of PE.

Zhonghua Liu Xing Bing Xue Za Zhi, 1992 Apr, 13(2), 106 - 9
{Studies on the serotyping and pyocintyping of Pseudomonas aeruginosa}; Li J; Pseudomonas aeruginosa (118 strains) from Xian were typed by 12 groups O-serum and revised pyocin typing method Results indicated that VI, I, III were major serotypes, VI type were mainly from trauma infected, I type mainly from respiration system infected . Pyocintype were mainly I and UT types . Pyocintype I were mainly 1/c and 1/x subtypes . 85.7% of 1/c subtypes were serotype VI, 84.4% of 1/x subtypes were serotype I.

J Chemother, 1992 Apr, 4(2), 78 - 81
Modification of Pseudomonas aeruginosa virulence factors by sub-inhibitory concentrations of antibiotics; Trancassini M et al.; This study's objectives were to evaluate the effects of subminimum inhibitory concentrations (MICs) of tobramycin, gentamicin, netilmicin, streptomycin, ciprofloxacin, cefotaxime and piperacillin on proteinase production, alginate and siderophore synthesis by two strains of Pseudomonas aeruginosa . One of these strains, of recent clinical isolation, was mucoid . In fact it is well known that mucoid strains are more resistant than non-mucoid; there is, moreover, evidence that in cystic fibrotic lungs the non-mucoid P . aeruginosa are invariably replaced by mucoid variants . Our results show that subinhibitory concentrations of beta-lactams and quinolones significantly reduced the amount of alginate . Protease production was affected by all antibiotics tested.

J Bacteriol, 1992 Apr, 174(7), 2178 - 84
Monoclonal antibodies as probes to examine serotype-specific and cross-reactive epitopes of lipopolysaccharides from serotypes O2, O5, and O16 of Pseudomonas aeruginosa; Lam JS et al.; Serotypes O2, O5, and O16 of Pseudomonas aeruginosa are chemically related, and the O antigens of their lipopolysaccharides share a similar trisaccharide repeat backbone structure . Serotype-specific monoclonal antibodies (MAbs) MF71-3, MF15-4, and MF47-4 against the O2, O5, and O16 serotypes, respectively, were isolated . MAb 18-19, which is cross-reactive with all strains of this chemically related serogroup, was also produced . When column chromatography or sodium dodecyl sulfate-polyacrylamide gel electrophoresis-separated lipopolysaccharide (LPS) samples from each of the serotypes were probed with the MAbs in Western immunoblots, each of the serotype-specific MAbs interacted only with high-molecular-weight bands of the homologous LPS, with a minimum O-antigen chain length of at least 6 to 10 repeats . In contrast, cross-reactive MAb 18-19 was shown to interact in Western immunoblots with the entire LPS banding pattern except the fastest-running band, which lacks O antigen . Chemical modification of P . aeruginosa LPS by alkali treatment and carboxyl reduction abolished reactions between LPS and MAb 18-19, while reactions of modified LPS with serotype-specific MAbs were not affected . Therefore, cross-reactive MAb 18-19 likely recognizes the chemical backbone structure of the O repeat that is common to all three serotypes of the O2-O5-O16 group, while the O-specific MAbs appeared to recognize LPS epitopes that could be presented when 6 to 10 or more O-antigen repeat units are present on the LPS molecule . Thus, the O-specific LPS epitopes likely involve unique chemical structures, glycosidic linkages, and some order of folding of the O side chains.

Infect Immun, 1992 Apr, 60(4), 1329 - 35
Role of energy metabolism in conversion of nonmucoid Pseudomonas aeruginosa to the mucoid phenotype; Terry JM et al.; Phosphatidylcholine, the major component of lung surfactant, when supplied as the sole source of phosphate for Pseudomonas aeruginosa PAO1, resulted in conversion of as much as 2% of the population to the mucoid phenotype under continuous culture conditions over a 24-day culture period . In addition, growth in phosphatidylcholine resulted in the highest yields of extracellular alginate compared with other environmental conditions . Iron limitation, another environmental condition relevant to the lungs of patients with cystic fibrosis, also resulted in conversion to mucoid . Since both conditions suggested the likelihood of an energy-deprived growth environment as a common variable, the effect of direct inhibition of energy generation by N,N'-dicyclohexylcarbodiimide or gramicidin on the conversion of nonmucoid P . aeruginosa to the mucoid phenotype was examined . Both inhibitors resulted in mucoid subpopulations (0.5 and 0.8%, respectively) . Severe energy stress imposed by the combination of phosphate limitation and N,N'-dicyclohexylcarbodiimide treatment resulted in conversion of 55% of the population to mucoidy during a 7-day growth period . A growth advantage of the mucoid over the nonmucoid phenotype was observed under severe nutrient deprivation by growth on unsupplemented Noble agar or in a 1/2,500 dilution of a chemically defined medium . These results clearly demonstrate a significant role for the energy state of the cell in conversion to mucoid and in selection for the mucoid phenotype.

Aktuelle Traumatol, 1992 Apr, 22(2), 72 - 5
{Treatment of osteomyelitis and reconstructive measures in patients with war injuries}; Peters KM et al.; 54 wartime trauma patients injured by bombs, shell splinters or rockets were treated between 1985 and 1989 in the Orthopaedic Clinic of RWTH Aachen . Lesions of the lower limbs were dominating (78%) . Treatment was often tedious, and up to 12 operations had to be performed . In 81% one extremity was injured, in 17% two extremities were involved . 78% of the patients were already primarily treated at home, mostly by amputations . 33% of the patients suffered from bone infections at admission . Infections were mostly caused by Staphylococcus aureus or Pseudomonas aeruginosa . In 41% of all patients operative treatment for osteomyelitis was necessary (37% sequesterectomies, 44% stabilisations with fixateur externe) . In advanced bone infection amputations were indispensable in 28% . In 27% of our wartime trauma patients reconstructive surgery was performed (spongiosa transplantations in 91%, stabilisation with fixateur externe in 44%) . In none of our patients treated with reconstructive surgery an amputation was necessary later on.

Circ Shock, 1992 Apr, 36(4), 256 - 64
Neutrophil short-lived oxidant production: enhancement following onset of sepsis-induced lung injury; Carey PD et al.; Generation of superoxide anion (O2-) by activated neutrophils (PMN) is implicated in the pathogenesis of endothelial cell injury in sepsis . To quantitate this phenomenon we studied the kinetics of O2- production by PMN following in vivo and in vitro exposure to Pseudomonas aeruginosa . PMN were isolated from young swine before and after a 1-hr infusion with 5 x 10(8) organisms/ml at 0.3 ml/20 kg/min . Baseline PMN were studied in an in vitro system where 1 x 10(6) porcine PMN were incubated with live Pseudomonas for 1 hr at 37 degrees C . Neutrophils from septic pigs exhibited a significantly increased (P less than 0.05) initial rate of O2 production, which was 125% greater at 2 min following initial stimulation than saline controls (P less than 0.001) . Neutrophils exposed in vitro displayed a similar enhancement of the rate of O2- production; however, the rate was 3.6 times greater than that noted in vivo . The in vivo change in PMN oxidant generation was associated with a rise in both extravascular lung water (EVLW) and increased bronchoalveolar lavage protein (BAL-P) content . These data suggest that sepsis-induced acute lung injury is accompanied by "priming" of circulating PMN; however, important factors are present in the circulation in sepsis that serve to attenuate the damaging potential of PMN oxidant species.

Infect Immun, 1992 Apr, 60(4), 1724 - 7
Age-dependent pulmonary clearance of Pseudomonas aeruginosa in a mouse model: diminished migration of polymorphonuclear leukocytes to N-formyl-methionyl-leucyl-phenylalanine; Sordelli DO et al.; Ten-, 20-, and 35-day-old mice were subjected to an aerosol containing Pseudomonas aeruginosa . The lung clearance of the organism was decreased in mice under 20 days of age . This deficiency was accompanied by decreased migration of polymorphonuclear leukocytes (PMN) to the airways in response to the P . aeruginosa challenge . Similar results were obtained in both outbred, C5-sufficient Swiss mice and inbred, C5-deficient DBA/2 mice . The diminished clearance of P . aeruginosa was related to a transient, age-related decrease in PMN chemotaxis to formyl-methionyl oligopeptides . PMN chemotaxis levels similar to those seen in adults were regained by day 35 after birth.

Carbohydr Res, 1992 Mar 30, 226(2), 313 - 26
Analysis of Macrocystis pyrifera and Pseudomonas aeruginosa alginic acids by the reductive-cleavage method; Zeller SG et al.; Permethylated alginic acids comprised of 4-linked D-mannopyranosyluronic acid and 4-linked L-gulopyranosyluronic acid residues undergo reductive cleavage to yield, after acetylation, methyl 3-O-acetyl-2,6-anhydro-4,5-di-O-methyl-D-mannonate (2b) and methyl 3-O-acetyl-2,6-anhydro-4,5-di-O-methyl-D-gluconate (3b) as major products . Small amounts (ca . 13%) of ring-contracted products, namely methyl 2-O-acetyl-3,6-anhydro-4,5-di-O-methyl-D-mannonate (9) and methyl 2-O-acetyl-3,6-anhydro-4,5-di-O-methyl-D-gluconate (10), were also observed in these experiments . These results are in marked contrast to previous results on the reductive cleavage of 4-linked D-glucopyranosyluronic acid residues, wherein the ring-contracted product was formed exclusively . Formation of the ring-contracted products could be completely eliminated by reduction (LiAlH4) of ester groups in the permethylated alginic acid prior to reductive cleavage . In the latter experiments, 4,6-di-O-acetyl-1,5-anhydro-2,3-di-O-methyl-D-mannitol (5b) and 4,6-di-O-acetyl-1,5-anhydro-2,3-di-O-methyl-L-gulitol (6b) were the sole products of reductive cleavage of the 4-linked ManA and 4-linked GulA residues, respectively . However, in the previous experiments it was noted that low yields of permethylated alginic acids were obtained and that extensive depolymerization occurred under methylation conditions . Depolymerization could be avoided and higher yields of permethylated polysaccharides could be obtained, by reduction of the carboxyl groups of the alginic acids prior to methylation . Reductive cleavage of the latter polysaccharides yielded the products expected from 4-linked D-mannopyranosyl and 4-linked L-gulopyranosyl residues, namely 4-O-acetyl-1,5-anhydro-2,3,6-tri-O-methyl-D-mannitol (13b) and 4-O-acetyl-1,5-anhydro-2,3,6-tri-O-methyl-L-gulitol (14b), respectively . Using the latter analytical strategy, it was established that the Macrocystis pyrifera alginate was comprised of 60% 4-linked ManA and 40% 4-linked GulA residues, whereas the Pseudomonas aeruginosa alginate was comprised of 80% 4-linked ManA and 20% 4-linked GulA residues.

FEBS Lett, 1992 Mar 24, 299(1), 96 - 8
Pseudomonas aeruginosa acid phosphatase . Activation by divalent cations and inhibition by aluminium ion; Domenech CE et al.; In Pseudomonas aeruginosa, the effect of different cations on the acid phosphatase activity was studied in order to acquire more information related to a previously proposed mechanism, involving the coordinated action of this enzyme with phospholipase C . Although the natural substrate of this enzyme is phosphorylcholine, in order to avoid the possible interaction of its positive charge and those of the different cations with the enzyme molecule, the artificial substrate p-nitrophenylphosphate was utilized . Kinetic studies of the activation of acid phosphatase (phosphorylcholine phosphatase) mediated by divalent cations Mg2+, Zn2+ and Cu2+ revealed that all these ions bind to the enzyme in a compulsory order (ordered bireactant system) . The Km values obtained for p-NPP in the presence of Mg2+, Zn2+ and Cu2+ were 1.4 mM, 1.0 mM and 3.5 mM, respectively . The KA values for the same ions were 1.25 mM, 0.05 mM and 0.03 mM, respectively . The Vmax obtained in the presence of Cu2+ was about twofold higher than that obtained in the presence of Mg2+ or Zn2+ . The inhibition observed with Al3+ seems to be a multi-site inhibition . The K'app and n values, from the Hill plot, were about 0.25 mM and 4.0 mM, respectively, which were independent of the metal ion utilized as activator . It is proposed that the acid phosphatase may exert its action under physiological conditions, depending on the availability of either one of these metal ions.

Biochim Biophys Acta, 1992 Mar 20, 1138(3), 243 - 50
Activation of human plasma prekallikrein by Pseudomonas aeruginosa elastase . II . Kinetic analysis and identification of scissile bond of prekallikrein in the activation; Tanaka H et al.; Activation of human plasma prekallikrein by a bacterial metalloendopeptidase, Pseudomonas aeruginosa elastase, was reported (Shibuya et al . (1991) Biochim . Biophys . Acta 1097, 23-27) . Details of the activation process were presently studied . The activation accompanied limited proteolysis of a peptide bond inside of a disulfide bridge of prekallikrein molecule . Amino acid sequencing analysis of the newly generated amino-terminal revealed that the cleavage site was Arg371-Ile372 bond which is the scissile bond in the activation of prekallikrein with trypsin-type proteinases . A pentapeptide substrate, 2-aminobenzoyl-Ser-Thr-Arg-Ile-Val-4- nitrobenzylamide, which contained the amino acid sequence identical to that around the scissile bond of prekallikrein was synthesized . Pseudomonal elastase, indeed, hydrolyzed the substrate at Arg-Ile bond with the kinetic parameters of Km = 118 microM, kcat = 1.56/s and kcat/Km = 1.33.10(4)/s M . These results indicated that the Arg371-Ile372 bond was sensitive not only to trypsin-type serine proteinases, but also a bacterial metalloproteinase . Kinetic analysis of the prekallikrein activation by pseudomonal elastase, however, revealed that the activation rate was slow, though the Km values was good enough to expect an occurrence of this activation in vivo (Km = 248 nM, kcat = 6.8.10(-4)/s, and kcat/Km = 2.7.10(3)/s M) . The activation rate of prekallikrein by pseudomonal elastase in Hageman factor deficient plasma was remarkably improved when the plasma was reconstituted with purified Hageman factor molecule . From the results, a biological significance of the proteinase cascade in the plasma kinin generation was also indicated . The present in vitro study might support the hypothesis that the Hageman factor/kallikrein-kinin system plays an important role in bacterial infection including the pseudomonal one.

FEBS Lett, 1992 Mar 16, 299(3), 291 - 3
Identification of cleavage sites involved in proteolytic processing of Pseudomonas aeruginosa preproelastase; Kessler E et al.; The extracellular elastase (33 kDa) of Pseudomonas aeruginosa is synthesized as a 53.6 kDa preproenzyme containing a long, N-terminal propeptide . The free propeptide and the elastase precursor generated upon propeptide removal were isolated from P . aeruginosa cells and subjected to N-terminal amino acid sequence analysis . The results identified Ala-174 and Ala+1 as the amino terminal residues of the propeptide and the elastase precursor, respectively, indicating that: (1) the signal peptide consists of 23 amino acid residues and its molecular weight is 2.4 kDa, (2) the propeptide contains 174 amino acid residues and is of 18.1 kDa molecular weight, and (3) no additional N-terminal proteolytic cleavage is required for elastase maturation.

J Biol Chem, 1992 Mar 15, 267(8), 5177 - 83
Immunoaffinity purification and reconstitution of sodium-coupled branched-chain amino acid carrier of Pseudomonas aeruginosa; Uratani Y; The gene product of braB encoding the Na+(Li+)-coupled carrier protein for L-leucine, L-isoleucine, and L-valine (LIV-II carrier) of Pseudomonas aeruginosa PML strain was identified and overexpressed using a T7 RNA polymerase/promoter plasmid system . The gene product was pulse-labeled with {35S}methionine as a protein of an apparent Mr of 34,000 on a sodium dodecyl sulfate-polyacrylamide gel . Cell membranes overproducing the LIV-II carrier were solubilized with n-dodecyl beta-D-maltopyranoside . The carrier protein was purified from the detergent extract by two purification steps: (i) immunoaffinity column chromatography using purified polyclonal antibody directed against synthetic 13-mer peptide corresponding to the carboxyl terminus region of the carrier and (ii) subsequent DEAE-cellulose column chromatography . The detergent was replaced by n-octyl beta-D-glucopyranoside prior to the first elution and phospholipid was present during purification . Proteoliposomes reconstituted with the purified LIV-II carrier exhibited Na+ or Li+ concentration gradient-driven transport of leucine, isoleucine, and valine . These results show that the LIV-II carrier was purified to be in a functional form.

Antimicrob Agents Chemother, 1992 Mar, 36(3), 620 - 5
Addition of rifampin to combination antibiotic therapy for Pseudomonas aeruginosa bacteremia: prospective trial using the Zelen protocol; Korvick JA et al.; A multicenter, prospective randomized trial was conducted to determine if the addition of rifampin to a combination therapy of an antipseudomonal beta-lactam agent and aminoglycoside improves the outcome of patients with Pseudomonas aeruginosa bacteremia . The Zelen protocol for randomized-consent design was used . Consent was sought only from patients randomized to the experimental therapy (rifampin+) . If the experimental therapy was refused, the patient would then receive the standard combination therapy (control); however, when outcome was evaluated, all patients randomized to the rifampin+ group, including those that declined rifampin, were compared with the control group . One hundred twenty-one consecutive hospitalized patients with positive blood cultures for P . aeruginosa were enrolled . Entry was stratified for prior use of empiric antipseudomonal antibiotics, neutropenia, severity of illness, and presence of pneumonia . Fifty-eight patients were randomized to receive rifampin (600 mg orally every 8 h for the first 72 h and then every 12 h for a total of 10 days) plus a beta-lactam agent plus an aminoglycoside . Sixty-three received the standard therapy of a beta-lactam plus an aminoglycoside agent (control) . Bacteriologic cure occurred significantly more frequently in patients randomized to the rifampin+ regimen . Breakthrough or relapsing bacteremias occurred in 2% of the three-drug (rifampin+) group, compared with 14% for the two-drug (standard therapy) group . Despite this favorable trend in bacteriological response, no significant differences in survival were seen for the two treatment groups . Rifamycin derivatives warrant further clinical study as antipseudomonal agents . The Zelen protocol appears well suited for comparative trials of antimicrobial agents.

Pediatr Pulmonol, 1992 Mar, 12(3), 158 - 61
Mucoid Pseudomonas aeruginosa is a marker of poor survival in cystic fibrosis; Henry RL et al.; The aim of this study was to assess the prognostic significance of mucoid and non-mucoid isolates of Pseudomonas aeruginosa (muPs and non-muPs) from the sputa of patients with cystic fibrosis (CF) . Eighty-one children with CF who coughed up sputum daily were recruited and followed over 12 months with frequent sputum cultures . At the end of this observation period they were classified to one of three age-matched groups . In 50 mPs was isolated on one or more occasions; 19 grew non-muPs but not muPs, and 12 grew no isolates of Ps aeruginosa . These 81 children and adolescents were followed for a further 8 years or until they died . Twenty-one (42%) of the muPs patients died compared with two (11%) of the non-muPs and one (8%) of the no Ps patients (P less than 0.01) . Stepwise regression indicated that forced expiratory volume in 1 second (FEV1) had the main predictive effect but that age, Shwachman score and muPs also had a predictive effect . Identification of mucoid forms of Ps aeruginosa is an unfavorable prognostic factor but the isolation of non-mucoid strains does not appear to be any more important than the isolation of other common respiratory pathogens.

Kansenshogaku Zasshi, 1992 Mar, 66(3), 407 - 15
{The study of pathogenic mechanisms of chronic Pseudomonas aeruginosa lung infections by mucoid strains}; Ohno A et al.; Chronic Pseudomonas aeruginosa lung infection with mucoid strains is the predominant cause of death in cystic fibrosis (CF) or diffuse panbronchiolitis (DPB) . This infection is characterized by a chronic course without spread of the bacteria to the blood when compared with other infections due to the non-mucoid strains . However, the mechanism of P . aeruginosa lung infection with the mucoid strains remains obscure . Intra-tracheal and systemic infection in mice, susceptibility to the bactericidal activity of fresh human and mouse serum, and adherent activity to mouse fetal lung cell were examined for mucoid and non-mucoid strains of P . aeruginosa . After intra-tracheal infection, the mucoid strains were distributed to other organs anormously but not the non-mucoid stains, and the bacterial number of the mucoid strains in the blood were significantly lower than that of the non-mucoid strains . On the other hand, when these strains were inoculated into the tail vein of mouse, the mucoid strain was eliminated more rapidly from blood as compared with the non-mucoid strain . The mucoid strains showed reduced bacteremic virulence when compared with non-mucoid strains with a 50% lethal dose (LD50) of 1.5 x 10(7) CFU/mouse as the mean value in a systemic infection . In contrast to the non-mucoid strains, the mucoid strains were sensitive to human fresh serum but were resistant to mouse fresh serum . The mucoid strains adhered to the monolayer of the mouse fetal lung cell 7-fold better than did non-mucoid strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Kansenshogaku Zasshi, 1992 Mar, 66(3), 360 - 6
{An outbreak of Pseudomonas folliculitis in children--the first report on Pseudomonas folliculitis in Japan}; Takigami T et al.; An outbreak of Pseudomonas aeruginosa folliculitis in 6 children occurred within 5 days after playing in a tiny vinyl pool . The follicular macular or pustular eruptions were mainly distributed on the trunk . No associated symptoms were seen . The causative Pseudomonas aeruginosa strain isolated from pustules of one case belonged to serogroup E, corresponding to O-11 (Difco) . The rash subsided promptly and spontaneously . Furthermore, we have encountered another case of Psedomonas folliculitis caused by P . aeruginosa serogroup G, corresponding to O-6 (Difco) . The maculopustular rash was distributed on the trunk and disappeared spontaneously as the cases mentioned above . The folliculitis of this baby were probably associated with the repeated use of family bath without changing water . In U.S . and Europe Pseudomonas folliculitis have been reported very frequently, but our cases were reported for the first time in Japan.

Antimicrob Agents Chemother, 1992 Mar, 36(3), 684 - 6
In vitro activity of E1040 against imipenem-resistant Pseudomonas aeruginosa strains; Watanabe M et al.; E1040 showed the most potent activity (MIC for 90% of strains, 6.25 micrograms/ml) among beta-lactams tested against 70 strains of imipenem-resistant Pseudomonas aeruginosa . Two strains showed high-level resistance to E1040; one strain produced a type II oxyiminocephalosporin-hydrolyzing beta-lactamase (group 3), and the other produced an enzyme similar to a type II penicillinase (OXA-1) . Both beta-lactamases contributed to resistance to E1040.

Microb Pathog, 1992 Mar, 12(3), 237 - 44
Role of elastase as a virulence factor in experimental Pseudomonas aeruginosa infection in mice; Tamura Y et al.; The role of elastase and alkaline protease in the pathogenesis of fatal infections caused by Pseudomonas aeruginosa was determined in mice treated with calcium chloride . Mortality increased significantly when solutions containing elastase were injected together with non-lethal inocula of strain PA 103, which does not produce proteolytic enzyme . In contrast, solutions containing alkaline protease did not increase mortality . In mice injected intramuscularly with strain PA 103 and calcium chloride, the organisms grew rapidly in the injected muscle but not in the liver . However, when elastase was injected together with strain PA 103 and calcium chloride, viable bacteria were also found in the liver . Moreover, the survival rate of mice challenged with elastase-producing strain 5 and calcium chloride was enhanced, and colonization of the liver prevented, by immunization with elastase toxoid . These results suggest that elastase contributes to the invasiveness of the organism.

J Antimicrob Chemother, 1992 Mar, 29(3), 287 - 97
Resistance to a new catecholic cephem, BO-1341, in Pseudomonas aeruginosa PAO; Hazumi N et al.; Two distinct types of mutant resistant to the catecholic cephem BO-1341 were isolated spontaneously from Pseudomonas aeruginosa PAO2146: (i) a mutant (CCB5-type) which produced beta-lactamase constitutively, and which appeared to result from a mutation in the regulatory gene (blaI at 41 min) controlling the structural gene (blaP at 25 min); (ii) a mutant (CCB7-type) with specific resistance to BO-1341 . Induction of beta-lactamase production in strain CCB7 by BO-1341 was diminished markedly when compared with that in the parent strain . This was not the case for ceftazidime or cefoxitin, suggesting impaired uptake of BO-1341 as an explanation for the resistance . Electrophoretic analysis demonstrated increased production of a 55 kDa protein in the periplasmic space and a 84 kDa outer membrane protein . These data suggested that specific resistance to BO-1341 might involve quantitative alterations in the composition of the outer membrane and periplasmic proteins.

Otolaryngol Head Neck Surg, 1992 Mar, 106(3), 230 - 4
Tympanomastoidectomy for chronic otitis media without cholesteatoma; Vartiainen E et al.; A series of 221 ears with chronic suppurative otitis media without cholesteatoma is presented--84% of the cases were treated using one-stage tympanomastoidectomy and 15% underwent cortical mastoidectomy with planned second-stage tympanoplasty . Mean follow-up period was 6.3 years . Control of infection succeeded in 92% after the primary operation . Failures were most common in ears infected with Pseudomonas aeruginosa . Postoperative cholesteatoma developed in 5 ears (2.2%) . Hearing results were unsatisfactory; a postoperative air-bone gap within 20 dB was achieved in only 62% . In revision operations, retained mastoid air cells were found in 64% of ears with recurrent or persistent discharge . Thirty-seven percent of patients with unsuccessful outcome were observed to have a possible underlying or concomitant disease . The importance of intensive preoperative conservative treatment and careful surgical technique is stressed.

Curr Eye Res, 1992 Mar, 11(3), 259 - 65
Ciprofloxacin and prednisolone therapy for experimental Pseudomonas keratitis; Hobden JA et al.; Rabbit corneas were injected intrastromally with Pseudomonas aeruginosa . Sixteen hours after injection, the rabbits were divided randomly into four treatment groups (3 rabbits/6 eyes per group: 1, ciprofloxacin and prednisolone; 2, ciprofloxacin only; 3, prednisolone only; 4, untreated . Ocular signs of inflammation were graded in a masked fashion by slit lamp examination before injection and 16 and 27 hours after injection . Slit lamp examination scores were significantly lower in eyes receiving ciprofloxacin and prednisolone or prednisolone alone, compared with scores in untreated eyes . Slit lamp examination scores were not significantly lower in eyes receiving ciprofloxacin alone, compared with untreated controls . The numbers of viable bacteria in the corneas treated with ciprofloxacin and in the corneas treated with ciprofloxacin and prednisolone were similar and were significantly less (P less than 0.0001) than those in untreated corneas, indicating that the presence of the steroid did not interfere with the bactericidal action of ciprofloxacin.

Med Hypotheses, 1992 Mar, 37(3), 186 - 90
Pseudomonas aeruginosa is retained in the bronchi of cystic fibrotics by the increased transepithelial potential; Dealler SF et al.; There is no hypothesis which satisfactorily unifies the abnormal secretions of electrolytes in cystic fibrosis (CF) with the thickened mucus and the retention of Pseudomonas aeruginosa (PA) . We have shown that mucus becomes opaque and more viscous adjacent to a positive electrode and that PA derived from CF sputum electrophoreses much faster than control PA . We propose that the increased transepithelial potential in CF respiratory tract acts to thicken mucus polymers thereby increasing its viscosity . We also suggest that as the thicker mucus forms on the epithelial surface bacteria with a high electrophoretic mobility (EM) are drawn into it and are thereby selected.

Cornea, 1992 Mar, 11(2), 143 - 7
Topical ofloxacin in the treatment of Pseudomonas keratitis in a rabbit model; Gritz DC et al.; Ofloxacin, a new quinolone antibiotic with a broad spectrum of activity, is very effective against Pseudomonas aeruginosa in vitro . Its effectiveness was studied in a rabbit model of tobramycin-sensitive P . aeruginosa . Treatment groups received either vehicle, tobramycin 0.3%, or ofloxacin 0.3% . Twelve hours of treatment decreased the bacterial counts from a mean of 2.2 +/- 0.7 x 10(6) colony forming units (cfu) per cornea in the vehicle group to means of 513 +/- 670 and 435 +/- 524 cfu in the tobramycin and ofloxacin groups, respectively . This decrease in bacterial counts was statistically significant (p = 0.001 for tobramycin and ofloxacin each compared with control, p = 0.86 for tobramycin compared with ofloxacin) . After seven days, all antibiotic-treated corneas were sterile and the epithelial defects healed at comparable rates . Aqueous humor drug levels were higher in infected eyes without an intact epithelium (p = 0.02); in eyes with intact epithelium, concentrations of ofloxacin were higher than were those of tobramycin (p = 0.002) . In this animal model, ofloxacin proved to be an effective antibiotic with no evidence of toxicity.

Mol Microbiol, 1992 Mar, 6(6), 751 - 60
An enzyme with type IV prepilin peptidase activity is required to process components of the general extracellular protein secretion pathway of Klebsiella oxytoca; Pugsley AP et al.; The last gene (pulO) of the pulC-O pullulanase secretion gene operon of Klebsiella oxytoca codes for a protein that is 52% identical to the product of the pilD/xcpA gene required for extracellular protein secretion and type IV pilus biogenesis in Pseudomonas aeruginosa . The PilD/XcpA protein is known to remove the first six amino acids of the signal sequence of the type IV pilin precursor by cleaving after the glycine residue in the conserved sequence GF(M)XXXE (where X represents hydrophobic amino acids) . This prepilin peptidase cleavage site is present in the products of four genes in the pulC-O operon (PulG, PulH, Pull and PulJ proteins) . It is shown here that PulO processes the pulG gene product in vivo . Processing was maximal within 15 seconds, but experiments in which the expression of pulO was uncoupled from that of the other genes in the secretion operon suggest that processing can also occur post-translationally . The products of two pulG derivatives with internal inframe deletions were also processed by PulO, but the three PulG-PhoA hybrids, two PulJ-PhoA hybrids and the single PulH-PhoA hybrid tested did not appear to be processed . Sucrose gradient fraction experiments showed that both precursor and mature forms of PulG appear to be associated with low-density, outer membrane vesicles prepared by osmotic lysis of sphaeroplasts . Neither the xcpA gene nor the Bacillus subtilis gene comC, which is also homologous to pulO and codes for a protein with type IV prepilin peptidase activity, can correct the pullulanase secretion defect in an Escherichia coli strain carrying all of the genes required for secretion except pulO . Furthermore, neither XcpA nor ComC is able to process prePulG protein in vivo.

Int J Dermatol, 1992 Mar, 31(3), 210 - 3
Activity of gentian violet and brilliant green against some microorganisms associated with skin infections; Bakker P et al.; The antimicrobial activity of gentian violet and brilliant green was tested against various strains of potential skin pathogens, by means of agar diffusion assay . The activity of both compounds was affected by pH . Gentian violet was found to be more active than brilliant green at pH 7.4, particularly against Pseudomonas aeruginosa . The spectrum of activity of gentian violet was not increased by the addition of brilliant green . An aqueous solution of gentian violet 0.5% turned out to be an adequate topical anti-infective drug . The preparation is particularly suitable for primary health care in tropical developing countries, because it is cheap, chemically and physically stable, and easy to prepare.

J Clin Microbiol, 1992 Mar, 30(3), 595 - 9
Isolation of a mucoid alginate-producing Pseudomonas aeruginosa strain from the equine guttural pouch; Govan JR et al.; The isolation and characterization of a mucoid, alginate-producing strain of Pseudomonas aeruginosa from a nonhuman host, namely, in chondroids from an equine guttural pouch, is reported for the first time . Pure cultures of P . aeruginosa 12534 were isolated from a 17-month-old pony mare with a history of chronic bilateral mucopurulent nasal discharge from the right guttural pouch . Transmission electron microscopy of chondroids showed mucoid P . aeruginosa growing as microcolonies within a matrix of extracellular material . On the basis of expression of the mucoid phenotype under different growth conditions, P . aeruginosa 12534 belongs to group 1 and resembles other isolates carrying the muc-23 mutation . The bulk of the extracellular material was characterized as being alginate by chemical and 1H nuclear magnetic resonance analyses, which showed that it had a composition similar to that produced by isolates of P . aeruginosa from human patients with cystic fibrosis.

Gene, 1992 Mar 1, 112(1), 45 - 51
Signal transduction in exopolysaccharide alginate synthesis: phosphorylation of the response regulator AlgR1 in Pseudomonas aeruginosa and Escherichia coli; Roychoudhury S et al.; Synthesis of alginate by Pseudomonas aeruginosa correlates with its pathogenicity in the lungs of patients suffering from cystic fibrosis (CF) . Alginate synthesis-encoding genes (alg) in P . aeruginosa are normally silent, but are specifically triggered in the CF lung environment . The promoter for the algD gene, located at the upstream end of the alg cluster, is activated by environmental factors such as high osmolarity, nutrient limitation and dehydration . Several regulatory proteins are known to control transcription from the algD promoter . Among these proteins is AlgR1 which is homologous to the phosphorylation-dependent response regulators of the two-component signal transduction system . In this paper, we report that AlgR2, an 18-kDa protein which in cooperation with AlgR1 regulates the algD promoter, undergoes phosphorylation in the presence of ATP . The phosphate group acquired by AlgR2 is then transferred to AlgR1 . In addition, we show that AlgR1 can be phosphorylated by an AlgR2-analog in Escherichia coli . AlgR1 is isolated in a phosphorylatable 80-kDa complex in association with AlgR2 in P . aeruginosa and the AlgR2-analog in E . coli.

Transplantation, 1992 Mar, 53(3), 620 - 3
The effects of cyclosporine and dexamethasone on an alveolar macrophage cell line (NR8383); Hidalgo HA et al.; Lung infections are a major source of morbidity and mortality in recipients of lung transplants . Prominent among the pathogens that cause pneumonias in these subjects are gram-negative bacilli, particularly Pseudomonas strains . One important reason that bacteria infect the lungs of these patients is that pulmonary defenses are impaired by the drugs used to prevent transplant rejection . Using a rat alveolar macrophage cell line (NR8383), we measured the effects of exposure (24 hr) to cyclosporine and dexamethasone (DEX) on the ability of these cells to (1) kill Pseudomonas aeruginosa (Pa); (2) produce H2O2; and (3) release tumor necrosis factor . We found that the bactericidal activity against unopsonized or opsonized Pa of NR8383 cells was unaltered by CsA (0.1, 0.5, or 1 micrograms/ml), DEX (10(-6) M), or CsA + DEX (0.5 micrograms/ml + 10(-6) M, respectively) . Likewise, LPS-induced TNF release, and zymosan A and Pa-induced H2O2 production were unaltered by CsA (0.1 or 1 microgram/ml) . In contrast, H2O2 production and TNF release were decreased by about 50% and 90%, respectively, by DEX exposure (10(-6) M) . Thus, while DEX but not CsA decreased TNF release and H2O2 production in NR8383 cells, bactericidal activity against Pa was unaffected . One explanation for these results is that decreases in TNF or H2O2 of the magnitude we observed do not impair bactericidal activity against Pa; however, an alternative explanation is that Pa are killed by NR8383 cells through other mechanisms . Interpretation of these results must take into consideration the fact that macrophages from different species and tissues may respond differently to various stimuli.

Transplantation, 1992 Mar, 53(3), 533 - 5
Pulmonary perfusion during lung transplant rejection and experimental pneumonia; Santillan-Doherty P et al.; Six left lung allotransplants were performed in healthy mongrel dogs . Immunosuppression was established with cyclosporine (15 mg/kg/day p.o.) from the day of transplantation for 30 days . Another group of animals (n = 3) was used to produce acute experimental pneumonia by instilling 4-6 ml of a 10(8) CFU suspension of Pseudomonas aeruginosa into the right lower lobe . Dynamic perfusory lung scintigraphy (DPLS) was performed before transplant/pneumonia (control), during acute rejection/pneumonia as detected radiologically, and after treatment with methylprednisolone (1 g/day for 3 days i.v.) (transplant group) or antibiotics (pneumonia group) . Seroalbumin macroaggregates (5-8 McI) marked with 99-mTc were injected into the cephalic vein and the percentage of perfusion to each lung was determined . Eight acute rejection episodes were detected . DPLS showed similar perfusion to each lung, whereas during acute rejection perfusion was significantly reduced by almost 30% . Perfusion was reestablished to control levels after treatment with methylprednisolone . Reduction in perfusion correlated with radiological rejection grading . No reduction in left lung perfusion was detected in pneumonia animals . In conclusion, acute rejection reduces perfusion to the transplanted lung as measured by DPLS . Treatment restores normal perfusion.

Infect Immun, 1992 Mar, 60(3), 885 - 91
Kinetics of serum, tear, and corneal antibody responses in resistant and susceptible mice intracorneally infected with Pseudomonas aeruginosa; Preston MJ et al.; The studies described here are aimed at determining the kinetics of antibody responses specific to Pseudomonas aeruginosa ATCC 19660 in sera, tears, and corneas of naturally resistant DBA/2 mice and susceptible C57BL/6 mice after intracorneal infection . Immunoglobulin (IgG) and IgM responses in sera were significantly greater in DBA/2 mice for the first 2 weeks postinfection . Little or no IgA was detected in the sera of mice from either strain . IgG was the predominant immunoglobulin class present in the corneas of the infected eyes from both mouse strains . However, differences in both the magnitude and the kinetics of the corneal IgG responses were noted between mouse strains . The kinetics of the corneal IgG responses were more similar to those of the serum IgG response than to those of the tear IgG response . Tear antibody responses in DBA/2 mice differed from those of C57BL/6 mice in two ways . First, there was a sharp increase in tear IgG levels 2 weeks after infection in DBA/2 mice that was not present in C57BL/6 mice . Second, IgA levels present in tears from the infected eyes of C57BL/6 mice dropped to nearly preinfection levels after the first week, whereas in DBA/2 mice, IgA levels remained elevated in the infected eyes after the first week . Determination of P . aeruginosa-specific antibody responses in the uninfected, contralateral control eyes revealed that IgA was detectable in the tears but not in the corneas of DBA/2 mice . Very little IgA was detected in the tears of the uninfected eyes of C57BL/6 mice . IgG was the only immunoglobulin class present in the uninfected corneas in both mouse strains tested . These results suggest that ocular IgA was made locally, whereas most ocular IgG may have originated from the serum, with some possible local synthesis . These immunological results indicate that DBA/2 and C57BL/6 mice respond differently to corneal challenge with P . aeruginosa.

Infect Immun, 1992 Mar, 60(3), 1128 - 39
Structure-function analysis of exotoxin A proteins with mutations at histidine 426; Wick MJ et al.; Substitution of Tyr for His-426 of Pseudomonas aeruginosa exotoxin A results in a mutant protein with reduced ADP-ribosyltransferase activity (M . J . Wick and B . H . Iglewski, J . Bacteriol . 170:5385-5388, 1988) . To investigate the role of His-426 in enzymatic activity, oligonucleotide-directed mutagenesis was used to construct mutant proteins encoding Ala, Glu, Gly, Lys, or Pro at position 426 . The effect of these amino acid substitutions on ADP-ribosyltransferase activity was analyzed in 34,000-Da carboxy-terminal exotoxin A peptides (H426n peptides) . ADP-ribosyltransferase activity of the H426n peptides fell within a range between 0.002 and 28% of wild-type levels of activity, suggesting that His-426 is required for full expression of enzymatic activity of exotoxin A . To investigate a possible catalytic function of His-426, the abilities of full-size (66,000-Da) wild-type exotoxin A and mutant proteins encoding either Ala-426 or Tyr-426 to hydrolyze NAD were compared by measuring NAD-glycohydrolase activity . This analysis revealed that exotoxin A encoding either Ala-426 or Tyr-426 expressed less than 1% of wild-type levels of NAD-glycohydrolase activity . Several criteria, including differential enzymatic activation properties and unique tryptic digestion patterns, revealed that the wild-type and mutant full-size proteins exhibit conformational differences . Our data suggest that His-426 plays a critical structural role in establishing the molecular architecture of the catalytic site in domain III and is important in orienting active-site residues in the cleft.

Eur J Biochem, 1992 Mar 1, 204(2), 789 - 92
Site-directed mutagenesis of the Pseudomonas aeruginosa cytotoxin for probing toxic activity; Xiong G et al.; The location of amino acids with direct influence on toxic activity in the pore-forming cytotoxin from Pseudomonas aeruginosa was tested by site-directed mutagenesis . Mutant fragments obtained by the polymerase-chain reaction were subcloned into a cytotoxin gene-bearing plasmid to minimize the possibility of amplification error . Our data suggest an important role of cysteines for toxic activity of cytotoxin . Furthermore, domain-facilitating-binding to plasma membranes is located on the C-terminal side of Cys215.

Acta Paediatr, 1992 Mar, 81(3), 227 - 30
Modification of some markers of inflammation during treatment for acute respiratory exacerbation in cystic fibrosis; Valletta EA et al.; An objective approach for monitoring the treatment of acute pulmonary exacerbation in cystic fibrosis was evaluated . Eleven biochemical markers of inflammation (erythrocyte sedimentation rate, neutrophil count, C-reactive protein, alpha-1 antitrypsin, haptoglobin, ceruloplasmin, fibronectin, alpha-1 glycoprotein, alpha-2 macroglobulin, C3, granulocyte elastase and anti-Pseudomonas IgG) were measured in blood serum and plasma from 46 cystic fibrosis patients with chronic Pseudomonas aeruginosa colonization before and after treatment . The overall outcome in each patient was evaluated by means of a pondered sum of clinical, chest X-ray and lung function scores . Biochemical markers were related to the overall clinical improvement: haptoglobin, ceruloplasmin, fibronectin and alpha-1 glycoprotein showed a good sensitivity (64-70%), specificity (60-70%) and positive predictive value (86-89%) . Granulocyte elastase showed a similar sensitivity (67%) and positive predictive value (85%) but a lower specificity (33%) . The negative predictive value was generally poor (32-39%) . Our data suggest that the combined measurement of some markers of inflammation and of conventional clinical parameters, may help in evaluating the efficacy of anti-infective treatment in cystic fibrosis.

Circ Shock, 1992 Mar, 36(3), 217 - 23
Reduction of endotoxin-induced vascular permeability by monoclonal antibodies against lipopolysaccharide determinants; Rubin RM et al.; Endotoxin, a bacterial lipopolysaccharide implicated in the pathogenesis of septic shock, markedly alters vascular permeability following intravenous injection in rabbits . We investigated the ability of murine monoclonal antibodies to confer protection against endotoxin-induced increases in a rabbit model of ocular vascular permeability . Four monoclonal antibodies of differing specificities as well as polymyxin B were compared for their effects on endotoxin from either Escherichia coli or Pseudomonas aeruginosa . Preincubation of endotoxin with antibodies directed against Pseudomonas O side chain or core glycolipid resulted in marked attenuation of vascular permeability due to Pseudomonas endotoxin, but not E . coli endotoxin . Antilipid A antibodies were not significantly effective in neutralizing either endotoxin with in vitro preincubation . Low avidity of the antilipid A antibody, low density of lipid A binding sites, or inaccessibility of the lipid A may have prevented more marked interactions . When administered intravenously prior to endotoxin challenge, none of the antibodies demonstrated the ability to provide specific protection to subsequent endotoxin in this model . They did provide partial nonspecific protection against endotoxins regardless of epitope specificity . When administered prophylactically, polymyxin B, an antibiotic that binds to lipid A, was highly effective in neutralizing the toxic effects of endotoxin . Since antibodies to lipid A reduce mortality in septic shock, the failure to demonstrate efficacy in this study may be due to the marked sensitivity of the rabbit eye to endotoxin . Alternatively, beneficial effects from antiendotoxin antibodies in septic shock may be unrelated to the inhibition of vascular permeability . Some protection from antiendotoxin antibodies may be due to enhancement of nonspecific mechanisms.

J Antimicrob Chemother, 1992 Mar, 29(3), 341 - 4
Temocillin and cystic fibrosis: outcome of intravenous administration in patients infected with Pseudomonas cepacia; Taylor RF et al.; Twelve courses of intravenous temocillin were given in combination with an intravenous aminoglycoside to five patients with cystic fibrosis (CF) for pulmonary exacerbations associated with Pseudomonas cepacia . All patients were infected concurrently with Pseudomonas aeruginosa in addition to P . cepacia . Improvement occurred after six of seven courses given to three patients in which temocillin was used as first-line therapy and following three of five courses given to two patients after failure of other antipseudomonal agents . All ten pre-treatment isolates of P . cepacia were resistant to aminoglycosides and eight were sensitive to temocillin . Clinical improvement was seen on both occasions in which the pre-treatment isolates were resistant to temocillin.

Infect Immun, 1992 Mar, 60(3), 1061 - 8
Binding of monoclonal antibody specific for domain Ia/II of Pseudomonas aeruginosa exotoxin A at pH 4 strongly neutralizes exotoxin A-induced cytotoxicity in cell culture and in vivo; Ohtsuka H et al.; Mouse monoclonal antibodies (MAbs) against Pseudomonas aeruginosa exotoxin A (Ex-A) were established, and 4 of 20 MAbs were extensively studied for analysis of the structure-function relationship of Ex-A . IN vivo experiments demonstrated that MAb Ex-3C7 protected mice either injected with Ex-A or infected with Ex-A-producing P . aeruginosa from death caused by Ex-A at the highest rate, followed by MAbs Ex-4F2 and Ex-8H5, in that order . MAb Ex-2A10 failed to rescue the mice . MAb Ex-3C7 (immunoglobulin G1 {IgG1}) inhibited incorporation of Ex-A into target cells and strongly neutralized cytotoxicity in cell culture but did not inhibit an enzymatic activity of Ex-A, ADP-ribosyltransferase, at all . The MAb also bound Ex-A, even at a low pH of 4, and recognized amino acid residues 241 to 297 (domain Ia/II), suggesting that MAb Ex-3C7 can interfere with the conformational change and/or processing of Ex-A by keeping a complex of Ex-A and antibody stable at low pH in the phagolysosome . MAb Ex-4F2 (IgG1), which recognizes residues 550 to 590 (domain III), strongly inhibited Ex-A incorporation and neutralized cytotoxicity in cell culture but only weakly inhibited ADP-ribosyltransferase . MAb Ex-8H5 (IgG1), which recognizes residues 591 to 613 (domain III), also inhibited cytotoxicity in cell culture, but weakly . In contrast to the above three MAbs, MAb Ex-2A10 (IgG2b) greatly inhibited ADP-ribosyltransferase but showed no inhibition of Ex-A incorporation and no neutralizing activity against cell toxicity . A line of evidence indicates that (i) domain Ia/II plays an important role in the pathogenesis of Ex-A and (ii) MAbs that inhibit an intracellular postbinding process, such as conformational change, processing, and translocation of Ex-A in target cells, can display potent inhibitory activity against cytotoxicity in vivo, as well as in cell culture, and would be a good candidate for therapy of pseudomonal infections.

J Hosp Infect, 1992 Mar, 20(3), 199 - 208
Epidemiology of Pseudomonas aeruginosa in an intensive care unit using selective decontamination of the digestive tract; Armstrong PJ et al.; Selective decontamination of the digestive tract (SDD) aims to reduce the rate of nosocomial infections in critical care patients . Pseudomonas spp . are common nosocomial pathogens and in this study isolates collected from patients and the environment during an SDD trial were examined . The study enrolled 161 SDD cases and 170 controls . Pseudomonads were isolated from 27% of SDD patients and 30% of controls . SDD partially suppressed colonization in the 'gastro-respiratory' mucosae but not in the rectum . A total of 108 isolates of pseudomonads were recovered from the environment . Resistance in rectal isolates was minimal but isolates from 'gastro-respiratory' sites showed increasing aminoglycoside resistance . Eighty-six per cent of aminoglycoside-resistant isolates from both patient groups and environment were pyocine type 1x . Episodes of infection were reduced in the SDD patients (6) compared with the controls (16), aminoglycoside-resistant strains being associated with zero episodes in SDD patients but with five in the control group.

Hum Genet, 1992 Mar, 88(6), 639 - 41
Lung involvement, the delta F508 mutation and DNA haplotype analysis in cystic fibrosis; Santamaria F et al.; Molecular studies of cystic fibrosis (CF) have allowed the genetic analysis of patients by means of DNA markers and the direct analysis of the CF gene . Some limited observations are available on the correlation between phenotype and genotype . Here, we report a study on the correlation of DNA haplotypes identified by KM-19 and XV-2c, the presence of the delta F508 mutation and lung involvement in 82 unrelated CF patients . Pulmonary involvement was defined by Chrispin's chest X-ray score, pulmonary function, sputum microbiology, serum immunoglobulin (SIg) levels and Shwachman's clinical score . Patients homozygous for haplotype B showed worse X-ray and clinical scores, more frequent sputum colonization by Pseudomonas aeruginosa and Staphylococcus aureus, lower spirometric values and raised concentrations of SIg G, A and M, compared with patients with other haplotypes . When lung involvement parameters were examined in patients homozygous, heterozygous or null for the delta F508 mutation, no difference was found among the three groups . Our data indicate a significant occurrence of severe pulmonary involvement in patients homozygous for the B haplotype; this is not influenced by the delta F508 mutation . We suggest that simple DNA haplotypes may provide data of both diagnostic and prognostic value, without the need for extensive and expensive molecular analyses.

Plasmid, 1992 Mar, 27(2), 105 - 18
Characterization of a Tra 2 function of RP1 that affects growth of Pseudomonas aeruginosa PAO and surface exclusion in Escherichia coli K12; Lyras D et al.; pVS438, a clone of part of the Tra 2 region of RP1 in RSF1010, confers two unusual phenotypes: poor growth (Slo+) in Pseudomonas aeruginosa PAO and surface exclusion (Sfx+) in Escherichia coli K12 . Both of these phenotypes were found to be encoded by a 1.8-kb fragment of RP1 (from 25.9-27.7 kb) that spans the traB gene . However, whether both phenotypes, neither, or only Slo+ is expressed by this fragment depends on its location and orientation in RSF1010 . In pVS438, where this fragment occurs in the SmR locus of RSF1010, expression of the Sfx+ phenotype is due to augmented transcription from the two promoters that cotranscribe the SuRSmR genes . When augmentation is abolished by insertion of Tn5 between these promoters and the cloned fragment, or by insertion of the fragment elsewhere in RSF1010, a Slo+Sfx- phenotype results . DNA that confers only the Slo+ phenotype was mapped to the 26.2-26.8 kb region of RP1 between traE and traB and the designation, traS, given to the gene responsible . Despite the recognition of a traS+ (Slo+) component of DNA within that encoding the Slo+ and Sfx+ phenotypes, this gene seems nevertheless to be responsible for the Sfx+ phenotype since hydroxylamine-induced Slo- mutants of pVS438 are usually also Sfx- . These apparently conflicting observations and the precise interplay between the Slo+, Sfx+, and TraB+ phenotypes were not resolved . Finally, traS is not essential for plasmid transfer since pVS438 and a Slo-Sfx- derivative of it can both equally complement an RP1tra-deletion mutant of part of the Tra 2 region.

J Gen Microbiol, 1992 Mar, 138 ( Pt 3), 605 - 10
Effects of growth temperature on alginate synthesis and enzymes in Pseudomonas aeruginosa variants; Leitao JH et al.; Spontaneous variation of the level of alginate synthesis in Pseudomonas aeruginosa was associated with changes in the activity of all four enzymes leading to synthesis of GDP-mannuronic acid, the activated precursor for polymerization . For the high-alginate-producing variant 8821M, alginate yield and properties, as well as the levels of alginate enzymes, were dependent on growth temperature . In contrast, levels of alginate and enzymes in the mucoid parent strain 8821 were very low and near temperature-independent . The difference in the specific activity of GDP-mannose dehydrogenase (GMD), encoded by the algD gene, between the two strains was associated with the alginate biosynthetic ability and with the degree of activation of the algD promoter, measured using the algD-xylE transcription fusion on plasmid pVD2X . Maximal activity of the four enzymes was observed in strain 8821M grown at 30 degrees C, a temperature below the optimum for growth (35 degrees C) . The effect of temperature on GMD activity could not be explained by the regulation of the algD promoter by temperature, since expression of pVDZX appeared to be more active at 35 degrees C, when the decrease of pVD2X copy number with increasing temperature was taken into account . The involvement of enzymes that catalyse steps downstream from the formation of the activated precursor should also be considered, as suggested by differences in the molecular mass of alginates synthesized by the two strains at various temperatures . Acetyl content of alginates increased as temperature decreased and strain 8821M produced the highest levels of acetylated polymers . The degree of acetylation appeared to be related to growth rate and could reflect acetyl-CoA availability.

J Antimicrob Chemother, 1992 Mar, 29(3), 307 - 12
Emergence of quinolone-imipenem cross-resistance in Pseudomonas aeruginosa after fluoroquinolone therapy; Aubert G et al.; Emergence of resistance to fluoroquinolones was observed in two clinical isolates of Pseudomonas aeruginosa after ciprofloxacin or norfloxacin monotherapy . In the first case, the resistant variants exhibited quinolone-imipenem cross-resistance (MIC of norfloxacin and ciprofloxacin: 16 mg/L; MIC of imipenem: 8 mg/L), although the patient had never received imipenem treatment, while the strain from the second case remained imipenem-susceptible (MIC of norfloxacin or ciprofloxacin: 8 mg/L; MIC of imipenem: 2 mg/I) . The frequency of in-vitro emergence of variants resistant to imipenem and fluoroquinolones was studied for the two strains, with imipenem or fluoroquinolones as selecting agents . Ciprofloxacin and three other quinolones (norfloxacin, temafloxacin and tosufloxacin) selected imipenem-resistant variants in a similar way to imipenem for the first strain, but not for the other . In contrast, imipenem did not select quinolone-resistant variants from either strain . For both strains, killing curves demonstrated that a bactericidal effect could be obtained with a drug combination (2 x MIC of ciprofloxacin and 2 x MIC of imipenem) without any selection of resistant mutants after 24 h, thereby suggesting the possible use of this combined regimen for treating severe P . aeruginosa infection.

J Bacteriol, 1992 Mar, 174(6), 1862 - 8
Characterization of stress-responsive behavior in Pseudomonas aeruginosa PAO: isolation of Tn3-lacZYA fusions with novel damage-inducible (din) promoters; Warner-Bartnicki AL et al.; Although the pervasive soil and water microorganism Pseudomonas aeruginosa demonstrates heightened sensitivity to UV radiation, this species possesses a recA gene that, based on structural and functional properties, could mediate a DNA damage-responsive regulon similar to the SOS regulon of Escherichia coli . To determine whether P . aeruginosa encodes such stress-inducible genes, the response of P . aeruginosa to DNA-damaging agents including far-UV radiation (UVC) and the quinolone antimicrobial agent norfloxacin was investigated by monitoring the expression of fusions linking P . aeruginosa promoters to a beta-galactosidase reporter gene . These fusions were obtained by Tn3-HoHoI insertional mutagenesis of a P . aeruginosa genomic library . Eight different damage-inducible (din) gene fusions were isolated which lack homology to the P . aeruginosa recA gene . Expression of the three gene fusions studied, dinA::lacZYA, dinB::lacZYA, and dinC::lacZYA, increased following UVC and quinolone exposure but not following heat shock . Similar to E . coli SOS genes, the din genes were induced to different extents and with dissimilar kinetics following UVC irradiation.

J Bacteriol, 1992 Mar, 174(5), 1568 - 73
arcD, the first gene of the arc operon for anaerobic arginine catabolism in Pseudomonas aeruginosa, encodes an arginine-ornithine exchanger; Verhoogt HJ et al.; In the absence of oxygen and nitrate, Pseudomonas aeruginosa metabolizes arginine via the arginine deiminase pathway, which allows slow growth on rich media . The conversion of arginine to ornithine, CO2, and NH3 is coupled to the production of ATP from ADP . The enzymes of the arginine deiminase pathway are organized in the arcDABC operon . The arcD gene encodes a hydrophobic polytopic membrane protein . Translocation of arginine and ornithine in membrane vesicles derived from an Escherichia coli strain harboring a recombinant plasmid carrying the arcD gene was studied . Arginine and ornithine uptake was coupled to the proton motive force with a bias toward the transmembrane electrical potential . Accumulated ornithine was readily exchangeable for external arginine or lysine . The exchange was several orders of magnitude faster than proton motive force-driven transport . The ArcD protein was reconstituted in proteoliposomes after detergent solubilization of membrane vesicles . These proteoliposomes mediate a stoichiometric exchange between arginine and ornithine . It is concluded that the ArcD protein is a transport system that catalyzes an electroneutral exchange between arginine and ornithine to allow high-efficiency energy conversion in the arginine deiminase pathway.

Schweiz Med Wochenschr, 1992 Feb 22, 122(8), 247 - 56
{Antibiotics 1992: mechanism of resistance and its clinical relevance}; Desgrandchamps D; In recent years, many new substances have been synthesized in the domain of beta-lactam antibiotics (penicillins, cephalosporins, monobactams, carbapenems), macrolide antibiotics, and quinolones . Their purpose was to counter the development of resistance to older antibiotics, or to achieve pharmacokinetic ameliorations . However, resistance of clinical relevance has also been observed with these new antibiotics: the effect of all third generation cephalosporins is neutralized by the overproduction of chromosomally encoded cephalosporinases (induction or stable derepression), or by the occurrence of extended-spectrum beta-lactamases . They should be used only with caution against bacteria with possible inducibility . In macrolide antibiotics, poor bioavailability after oral administration can lead to therapeutic failure . The improved pharmacokinetic properties of the new macrolide antibiotics can correct this disadvantage . The generally highly active quinolone antibiotics show diminished activity against grampositive bacteria and Pseudomonas aeruginosa . Careful surveillance of resistance and critical use of the quinolones are essential for the prevention and control of resistance.

Biochim Biophys Acta, 1992 Feb 14, 1138(2), 162 - 6
Conformational integrity of a recombinant toxoid of Pseudomonas aeruginosa exotoxin A containing a deletion of glutamic acid-553; Killeen KP et al.; A mutant form of Pseudomonas aeruginosa exotoxin A (ETA) carrying a deletion of glutamic acid-553, an important active-site residue, was expressed in an ETA-negative strain of P . aeruginosa and shown to be exported from the cells as efficiently as wild-type ETA . The mutant protein, purified from the culture medium, was devoid of ADP-ribosyltransferase activity . Protein conformation was barely perturbed by the deletion, as determined by a number of measures, including affinity for substrate NAD, proteinase sensitivity, absorbance and fluorescence spectroscopy, and differential scanning calorimetry . The conformational integrity and stability of the mutant toxin are consistent with potential use of the protein in vaccines or as a carrier in preparing conjugate vaccines.

Res Immunol, 1992 Feb, 143(2), 165 - 74
Properties determining the potential of naturally occurring and vaccine-induced human antibodies to protect against lethal infection of Pseudomonas aeruginosa; Bruderer U et al.; In order to characterize antibodies responsible for the protection against fatal infection with Pseudomonas aeruginosa we analysed the fine specificity, avidity and protective capacities of naturally occurring anti-lipopolysaccharide (LPS) antibodies in two standard human Ig preparations and of vaccine-induced anti-LPS antibodies in a hyperimmune Ig preparation . Applying competitive binding assays, immunoblotting and an in vivo protection assay, we provide evidence that only preparations from immunized volunteers contain significant amounts of antibodies which confer detectable protection in a murine burn-wound model . Supported by the parallel analysis of monoclonal antibodies, our data suggest that protection by passive immunization with anti-LPS antibodies is mediated by antibodies specific for the LPS O-chain moiety of the corresponding virulent bacterium . Furthermore, our results indicate that protectiveness is restricted to a small population of antibodies with high affinity for particular O-chain epitopes.

J Med Microbiol, 1992 Feb, 36(2), 104 - 11
Epithelial respiratory cells from cystic fibrosis patients do not possess specific Pseudomonas aeruginosa-adhesive properties; Plotkowski MC et al.; Nasal polyp cells in primary culture from cystic fibrosis (CF) and non-CF patients were compared for the ability to bind Pseudomonas aeruginosa cells and for the presence of sulphated glycoconjugates at the epithelial cell surface . Quantitation of bacterial adhesion, by scanning electronmicroscopy, showed no significant difference between the cells cultured from CF and non-CF patients . Micro-organisms associated with ciliated cells were mainly aggregated, in contrast with those from non-ciliated cells . Sulphated glycoconjugates were identified on cells cultured from both CF and non-CF patients, regardless of whether or not these cells had attached bacteria . A matrix-like material that surrounded the aggregated bacteria was more prominent on cells cultured from CF patients than on those from non-CF patients . The interaction of aggregated P aeruginosa cells with polyp cells cultured from both CF and non-CF patients appeared to occur by means of this matrix material . Our findings suggest that chronic colonisation of the airways of CF patients cannot be explained by an increased affinity between the P . aeruginosa cells and the respiratory cell surface receptors in the CF patient . Nevertheless, the in-vitro observation that the matrix surrounding the bacteria reacted with a monoclonal antibody against respiratory mucins allows us to speculate that increased mucin secretion by cells from CF patients might, in vivo, play a decisive role in the interaction between P . aeruginosa and the respiratory epithelium.

J Clin Invest, 1992 Feb, 89(2), 657 - 65
Binding of nonmucoid Pseudomonas aeruginosa to normal human intestinal mucin and respiratory mucin from patients with cystic fibrosis; Sajjan U et al.; Lung infections due to Pseudomonas aeruginosa and Pseudomonas cepacia are common in patients with cystic fibrosis . Initial colonization is due to nonmucoid P . aeruginosa, while later mucoid variants emerge and are associated with chronic infection . P . cepacia colonization tends to be more prevalent in older patients . The present study was conducted to discover whether highly purified mucins (from cystic fibrosis sputum and control intestinal secretions) exhibited specific binding of nonmucoid P . aeruginosa . In vitro solid phase microtiter binding assays (with or without a blocking agent) as well as solution phase assays were conducted . Bacteria bound to both mucins via bacterial pili, but no differences in binding capacity were noted between the mucins . Unlike P . cepacia (described in the accompanying manuscript) there was also no preferential binding of P . aeruginosa to mucins versus bovine serum albumin, casein, gelatin, or a host of structurally unrelated proteins and glycoproteins . Carbohydrate hapten inhibition studies did not suggest the existence of specific mucin carbohydrate receptors for P . aeruginosa . In solid phase assays a low concentration (0.05 M) of tetramethylurea abolished P . aeruginosa bacterial binding to both mucins as well as to BSA, whereas in solution phase assays mucin binding to bacteria was not completely disrupted by tetramethylurea . Specific monoclonal antipilus antibodies did not inhibit binding to a greater extent than did Fab fragments of normal mouse IgG . Binding of strains PAO1 and PAK (and isolated PAK pili) to buccal epithelial cells was not influenced by the presence of mucin in binding assay mixtures . Our findings do not support the widely held notion that specific mucin receptors are responsible for the attachment of P . aeruginosa pili, nor do they support the idea that there is a competitive interference by mucins of bacterial binding to respiratory cells . In patients with cystic fibrosis, it would seem unlikely therefore that initial colonization of the lungs by P . aeruginosa is due to a 'selective tropism' of these bacteria for respiratory mucin.

Infect Immun, 1992 Feb, 60(2), 584 - 9
Comparative immunogenicity of conjugates composed of the Staphylococcus aureus type 8 capsular polysaccharide bound to carrier proteins by adipic acid dihydrazide or N-succinimidyl-3-(2-pyridyldithio)propionate; Fattom A et al.; Staphylococcus aureus type 8 capsular polysaccharide (CP) was conjugated either to diphtheria toxoid or to Pseudomonas aeruginosa recombinant exoprotein A by using adipic acid dihydrazide (ADH) or N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP) as the joining reagent . The polysaccharide/protein ratios of these two pairs of conjugates were similar . The two synthetic schemes bound the linker to the carboxyls of the type 8 CP by carbodiimide-mediated condensation . ADH was bound to the carboxyls of the protein, whereas SPDP reacted with the amino groups of the protein . Intermolecular linking of the carrier protein, caused by the carbodiimide during the conjugation reaction with the type 8 CP derivative, probably accounts for the larger size of the conjugates formed with ADH compared with those formed with SPDP . Both conjugates synthesized with ADH elicited higher levels of CP antibodies, especially after the first immunization, than did those prepared with SPDP . Similar levels of exoprotein A antibodies were elicited by both conjugates . Higher levels of diphtheria toxoid antibodies were elicited by the conjugate prepared with SPDP than by the one prepared with ADH . The basis for the differences in the immunogenicities of these two pairs of S . aureus type 8 CP conjugates is discussed.

Infect Immun, 1992 Feb, 60(2), 510 - 7
Isolation and characterization of toxin A excretion-deficient mutants of Pseudomonas aeruginosa PAO1; Hamood AN et al.; We have isolated and characterized four toxin A excretion-deficient mutants of Pseudomonas aeruginosa PAO1 . Similar to previously described mutants (B . Wretlind and O . R . Pavlovskis, J . Bacteriol . 158:801-808, 1984), the mutants appear to have a pleiotropic defect in the excretion of several extracellular products, including toxin A, elastase, alkaline phosphatase, and phospholipase C . However, the mutants are not defective in the excretion of either alkaline protease or exoenzyme S . We also examined the localization and processing of toxin A in these mutants by using pulse-labeling experiments . Mature toxin A was found to be localized to the membranes only . Our results suggest that toxin A is localized to the outer membrane but is not exposed to the extracellular surfaces of the outer membranes . The results also suggest that toxin A obtained from the excretion-deficient mutants has intact disulfide bonds.

Infect Immun, 1992 Feb, 60(2), 328 - 36
Response of Pseudomonas aeruginosa to pyocyanin: mechanisms of resistance, antioxidant defenses, and demonstration of a manganese-cofactored superoxide dismutase; Hassett DJ et al.; Pseudomonas aeruginosa produces a blue pigment, pyocyanin . Pyocyanin is a redox-active phenazine compound that kills mammalian and bacterial cells through the generation of reactive oxygen intermediates . We examined the mechanisms by which P . aeruginosa resists pyocyanin . {14C}pyocyanin was taken up by both Escherichia coli and P . aeruginosa, though more slowly by the latter . Cyanide-insensitive respiration, used as an indicator of intracellular superoxide and/or hydrogen peroxide production, was 50-fold less in pyocyanin-treated P . aeruginosa than in E . coli . P . aeruginosa showed less cyanide-insensitive respiration than E . coli upon exposure to other redox-active compounds (paraquat, streptonigrin, and plumbagin) . Electron paramagnetic resonance spectrometry and spin trapping showed that P . aeruginosa generated less pyocyanin radical and superoxide than E . coli . Cell extracts from E . coli contained an NADPH:pyocyanin oxidoreductase which increased the rate of reduction of pyocyanin by NADPH . Conversely, cell extracts from P . aeruginosa contained no NADPH:pyocyanin oxidoreductase activity and actually decreased the rate of pyocyanin-mediated NADPH oxidation . Antioxidant defenses could also reduce the sensitivity of P . aeruginosa to pyocyanin . Under culture conditions of limited phosphate, both pyocyanin production and catalase activity were enhanced . Superoxide dismutase activity was also increased under low-phosphate conditions . When cells were grown in a high-phosphate succinate medium, P . aeruginosa formed a previously described iron-superoxide dismutase as well as a manganese-cofactored superoxide dismutase . These results demonstrate that P . aeruginosa resists pyocyanin because of limited redox cycling of this compound and that under conditions favoring pyocyanin production, catalase and superoxide dismutase activities increase.

Clin Immunol Immunopathol, 1992 Feb, 62(2), 133 - 8
Effect of Pseudomonas aeruginosa elastase and alkaline protease on serum complement and isolated components C1q and C3; Hong YQ et al.; The present study was undertaken to examine and compare the direct effect of two Pseudomonas enzymes, elastase and alkaline protease, on the serum hemolytic complement as a whole, and on the two recognition molecules of complement, C1q and C3 in particular . The results of our study show that incubation of serum with 0-50 micrograms/ml elastase or protease (60 min, 37 degrees C) resulted in a dose-dependent depletion of hemolytic complement with the protease being 3-4 times more efficient than elastase . Incubation of highly purified C3 (20 hr, 37 degrees C) with protease (2% w/w) resulted in the conversion of the 190-kDa molecule to a 120-kDa fragment . When analyzed by SDS-PAGE under reducing conditions, the 120-kDa piece yielded three distinct bands: an intact 75-kDa beta-chain and two alpha-chain pieces of approximately 41- and 26-kDa . NH2-terminal end sequence analysis localized the 26-kDa fragment within the cysteine-rich 41-kDa, COOH-terminal piece . This in turn suggests that the 70-kDa fragment which is not accounted for on SDS-PAGE is derived from the NH2-terminal end of the alpha-chain molecule which is completely degraded into small fragments . While the degradation pattern obtained with elastase is similar to that of protease, the latter enzyme was found to be more efficient . Exposure of C1q (0-5 hr, 37 degrees C) to protease or elastase on the other hand appears to reveal preferential sensitivity of the 28-kDa A-chain and 24-kDa C-chain, of the C1q molecule, with the protease being more potent than the elastase . Since both C1q and physiologic fragments of C3 (C3b, iC3b, and C3dg) are important opsonins of varying efficiencies, degradation of these molecules by Pseudomonas enzymes may, in part, facilitate the survival and proliferation of the organism in plasma . Furthermore, degradation of the key recognition molecules of complement, C1q and C3, would enhance the virulence of this organism by aborting complement-mediated bacterial killing . In addition the results imply that during Pseudomonas bacteremia, PaAP may be a much more destructive enzyme than PaE with regards to C3 and C1q but combined, the synergistic effect may overwhelm not only the proteins of the complement system, but other proteins of the humoral immune defense system as well.

Eur J Cell Biol, 1992 Feb, 57(1), 95 - 100
Lung surfactant protein A (SP-A) enhances serum-independent phagocytosis of bacteria by alveolar macrophages; Manz-Keinke H et al.; Surfactant protein A (SP-A) is the main protein component of lung surfactant . We studied the involvement of SP-A in body defense, i.e., effect of SP-A on the phagocytosis of bacteria by alveolar macrophages . We show here that SP-A enhances the phagocytosis of some non-opsonized bacteria: Escherichia coli growing logarithmically (E . coli/log), Pseudomonas aeruginosa/log as well as from stationary phase (P . aeruginosa/stat) and Staphylococcus aureus/log . Furthermore, not only serum-independent phagocytosis was effected by SP-A but also phagocytosis of serum-opsonized S . aureus/stat . No effect of SP-A on phagocytosis was observed with E . coli/stat neither on serum-independent nor on serum-dependent phagocytosis and on phagocytosis of non-opsonized S . aureus/stat . Thus, effect of SP-A on phagocytosis is dependent on bacterial species and on the growth phase of the microorganisms, and this effect is concentration dependent . We studied two different human recombinant SP-As and SP-A isolated from lung lavage material from proteinosis patients . These SP-A molecules contain different isomeric chains, and they differ in complexity of their structure . Qualitatively, we found the same effect with all three substances . Quantitatively, the proteinosis SP-A that forms the most complex structure was the most effective . Taken together, we demonstrated a stimulating effect of SP-A on serum-independent as well as on serum-dependent phagocytosis of bacteria by alveolar macrophages, both depending on species and growth phase of the bacteria.

Acta Crystallogr B, 1992 Feb 1, 48 ( Pt 1), 107 - 9
Crystallization and preliminary crystallographic data for the azurin mutant Ala 114 from Pseudomonas aeruginosa; Tsai LC et al.; The site-specific mutant alanine 114 of the blue copper protein azurin from Pseudomonas aeruginosa in Escherichia coli has been crystallized from PEG 4000 in a new crystal form compared to the wild type utilizing the hanging-drop procedure . The crystals are blue well-formed prisms . Monoclinic, P2(1), a = 51.03 (5), b = 83.36 (5), c = 66.30 (6) A and beta = 111.0 (1) degrees . 14,875 reflections up to 2.7 A have been collected using a modified Syntex P2(1) automated four-circle diffractometer.

Appl Environ Microbiol, 1992 Feb, 58(2), 677 - 85
Use of monoclonal antibodies to demonstrate different sites with different functional characteristics in a bacterial lipase from Pseudomonas aeruginosa YS-7; Daya-Mishne N et al.; Structural and functional features of the extracellular lipase from the low-water-tolerant bacterium Pseudomonas aeruginosa YS-7 were studied immunochemically with the aid of monoclonal antibodies (MAbs) raised against the enzyme . Fourteen different MAbs were obtained, verified as immunoglobulin G types, and characterized by their interaction with the enzyme in relation to (i) inhibition of activity of free enzyme, (ii) inhibition of activity of adsorbed enzyme, (iii) interaction with the cell-bound enzyme, and (iv) inhibition of adherence to hexadecane droplets . Four of the MAbs exhibiting the highest binding constants (Kapp greater than 10(8) M-1) were selected for further study of the lipase . Their binding to the enzyme was assayed by means of adapted enzyme-linked immunosorbent assay techniques . Use of these MAbs in single or dual binding procedures made it possible to reveal several distinct sites on the lipase macromolecule . Two of these are functional sites, one for hydrophobic adhesion (binds MAb 5) and the other (binds MAb 1) for implementation of its hydrolytic activity . A third binding site (binds MAb 8) does not participate directly in either of the above functions . A fourth binding site (binds MAb 10) appears to be involved in the active expression of the enzyme . The cell-associated form of the lipase seems to be located on the external surface of the cells with its active site exposed . It appears to be anchored to the outer membrane of the cells by means of its hydrophobic region in a way that resembles its adherence to hydrophobic surfaces such as hexadecane droplets.

Antimicrob Agents Chemother, 1992 Feb, 36(2), 313 - 7
Augmentation of the antibacterial activity of magainin by positive-charge chain extension; Bessalle R et al.; Novel analogs of the broad-spectrum antimicrobial peptide magainin-2 were obtained by extension of its chain through addition of segments of positively charged amino acids to either its N or its C terminus and by increasing its helicity . The activity of magainin-2 toward American Type Culture Collection strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was most considerably enhanced by these modifications, whereas, in general, its low hemolytic capacity was not or was only slightly affected . The antibacterial potencies of magainin-2 and its derivatives were more evident following decreases of pH from 7.2 to 6 and 5.

Biol Chem Hoppe Seyler, 1992 Feb, 373(2), 93 - 100
Solubilization of the binding protein from Ehrlich ascites cells and erythrocytes to Pseudomonas aeruginosa cytotoxin; Jungblut R et al.; The binding protein for pore-forming Pseudomonas aeruginosa cytotoxin was solubilized from Ehrlich ascites cell plasma membranes and rabbit and bovine erythrocyte ghosts using nonionic and zwittergent detergents . Analysis of solubilized plasma membranes from Ehrlich cells by a ligand-blot technique after separation by SDS-PAGE/electrophoretic transfer to nitrocellulose or affinity chromatography showed a protein of 70 kDa molecular mass, which binds to cytotoxin . The binding protein solubilized from rabbit erythrocyte ghosts showed a molecular mass of 50 kDa and that from bovine ghosts 55 kDa according to the former test . The binding proteins could be characterized as acidic . They contain a glycan moiety which is, however, not involved in the interaction of cytotoxin with the binding site.

Nervenarzt, 1992 Feb, 63(2), 108 - 12
{Intraventricular antibiotic therapy}; Thilmann AF et al.; While shunt infections are regularly treated with intraventricular antibiotics, the validity of such an application in bacterial meningitis of other origin is controversial . We report two cases of partly successful treatment with intraventricular Ceftazidime (10-20 mg twice per week) . One patient with pseudomonas aeruginosa meningitis who was treated as an out-patient for nearly two years died after an attempted withdrawal of the intraventricular treatment . In our experience, intraventricular application of antibiotics can be a part of the therapeutic regimen in all cases of chronic meningitis with problematic bacteria . Depending on the bacillus, Ceftazidime, Vancomycin or Netilmicin can be recommended for intrathecal application.

J Gen Microbiol, 1992 Feb, 138 ( Pt 2), 289 - 96
Variable cross-reactivity of Pseudomonas aeruginosa lipopolysaccharide-code-specific monoclonal antibodies and its possible relationship with serotype; Yokota S et al.; The core region of Pseudomonas aeruginosa lipopolysaccharide (LPS) was analysed by four LPS-core-specific human monoclonal antibodies (mAbs; FK-2E7, MH-4H7, OM-1D6 and NM-3G8) . Reactivity of these mAbs to about 180 P . aeruginosa strains was tested . FK-2E7 bound to strains of Homma serotype E and I at a frequency of about 90%, to strains of serotype M at about 50%, and to strains of serotype A and G at about 30% . MH-4H7 bound to P . aeruginosa strains of serotype A, F, G, H, K and M at a high frequency (45-87%), but did not bind to any strains of serotype B, C, E and I . OM-1D6 and NM-3G8 bound to P . aeruginosa strains in a nearly serotype-specific manner . OM-1D6 reacted with all strains of serotype G so far tested, and a few strains of serotype M . Furthermore, L-rhamnose in the LPS core of serotype G was an immunodominant sugar recognized by OM-1D6 as an epitope . NM-3G8 bound to only a few strains of serotype B and M . The variable reactivity of these mAbs suggests that antigenic heterogeneity of the LPS core is somewhat related with (O-polysaccharide-based) serotype . Among these mAbs, MH-4H7 and OM-1D6 showed a high level of protective activity against P . aeruginosa in an experimental infection model using normal mice . In vivo protective activity was shown to be closely related to in vitro binding activity to whole cells as determined by agglutination and flow cytometry, but not ELISA.

Hinyokika Kiyo, 1992 Feb, 38(2), 213 - 7
{A case of hematuria associated with cefem group antibiotics}; Okuno H et al.; The patient was a 76-year-old male with disturbance of consciousness due to cerebral infarction . He was found lying in his garden on July 30, 1990 and was immediately hospitalized . Central venous alimentation was started on the same day, because the patient was incapable of oral nutritional intake . Aspiration pneumonia developed on August 3 . As Pseudomonas aeruginosa and Candida were detected by sputum cultures on August 20, antibiotics were changed to latamoxef (LMOX), 6 g/day, tobramycin, 180 mg/day, and fluconazole, 200 mg/day, from August 30 . Macroscopic hematuria was noted after exchange of the urethral catheter . Hematuria gradually worsened, bladder tamponade occurred, and anemia had exacerbated with Hb decreasing from 13.4 to 8.7 g/dl and Hct from 39.1 to 26% on September 14, when the patient was referred to our department . Corresponding marked increases were observed in PT from 11.5 to 50.1 seconds and in APTT from 33.7 to 107.6 seconds . As the hematuria was suspected to be due to vitamin K deficiency hypoprothrombinemia induced by LMOX, its administration was discontinued on the day of the referral . Hematuria was alleviated from the next day, and PT normalized to 12.1 seconds and APTT to 36.6 seconds 3 days after discontinuation . The administration of vitamin K was started on this day, and hematuria disappeared 7 days after discontinuation of LMOX administration.

Toxicon, 1992 Feb, 30(2), 161 - 9
In vivo and in vitro toxicity of phospholipase C from Pseudomonas aeruginosa; Meyers DJ et al.; Pseudomonas aeruginosa produces phospholipase C (PLC), a heat-labile hemolysin . Histopathological analysis of PLC-treated mice revealed that the primary target organs involved in PLC-induced toxicity were the liver and kidney . Mice treated i.v . with PLC demonstrated significant tubular epithelial necrosis of the kidney with hematuria, while when given i.p . they exhibited hepatonecrosis with cellular infiltration . Splenomegaly was also a consistent finding . Results from in vitro studies indicate that PLC is toxic for mouse peritoneal cells and human leukocytes.

Scand J Dent Res, 1992 Feb, 100(1), 52 - 9
Recent development in endodontic research; Tronstad L; In essence, endodontics as a clinical discipline is concerned with the prevention and treatment of pulpal and periapical infection . In recent research the infective process has been investigated as well as the mechanisms by which the pulp and periodontium deal with microbial insults . With regard to the pulp, findings on the hemodynamics of pulpitis suggest that the inflammatory response in this tissue is much less influenced by the special anatomic environment of the tooth than was previously believed . Pulpal diseases are being underdiagnosed, mostly because of inadequate examination methods . Laser Doppler flowmetry which gives a vascular rather than a nervous response may gain importance in pulpal diagnostics in the future . It is established that apical periodontitis with bone resorption cannot develop in the absence of bacteria in the root canal system . Root canal infection is characterized by a wide variety of combinations of relatively few anaerobic bacteria, and bacterial synergism plays an important role in maintaining the infection . Microbial invasion of an apical granuloma may take place . Non-oral and environmental organisms like Pseudomonas aeruginosa are frequently isolated from treatment-resistant cases . Success of endodontic treatment depends on the reduction or elimination of the infecting bacteria . This may predictably be obtained after a thorough chemo-mechanical instrumentation and disinfection of the root canal with calcium hydroxide . The standardized technique which entails the preparation of a cylindrical apical box with removal of significant amounts of dentin near the root apex predictably gives a clean canal . This technique has provided excellent clinical and radiographic results in well documented follow-up studies.

Physiol Behav, 1992 Feb, 51(2), 363 - 9
Effect of burn wound bacterial colonization on sleep and respiratory pattern; DeMesquita S et al.; This study examined the effect of bacterial colonization of a burn wound on the sleep pattern and respiration during sleep . Sleep patterns of adult rats were monitored for one week before and two weeks after a 30 percent total body surface, full skin thickness burn with and without seeding the fresh wound with nonvirulent Pseudomonas aeruginosa . Unseeded rats were euthermic and exhibited a normal sleep pattern during the first-week post burn; however, rapid eye movement (REM) sleep percent was significantly decreased by the second week due to a reduction in the frequency rather than duration of REM periods . Rats with seeded wounds were febrile and had a significantly lower REM sleep percent throughout the two-weeks post burn due to a reduction in frequency but not duration of REM periods . The increase in respiratory rate from the non-REM to REM sleep state observed before injury was abolished in the seeded group post burn . There was an immediate but transient 24 h drop in REM sleep following thermal injury . Bacterial colonization of the burn wound by either immediate, artificial seeding or by delayed, spontaneous means significantly decreased REM sleep with and without fever, respectively . These results indicate that noninvasive bacterial colonization of a burn wound was capable of decreasing REM sleep without causing fever and that REM sleep reduction was a more sensitive indicator of the extent of burn wound bacterial colonization than was colonic temperature.

Clin Infect Dis, 1992 Feb, 14(2), 403 - 11
Life-threatening Pseudomonas aeruginosa infections in patients with human immunodeficiency virus infection; Kielhofner M et al.; Bacterial infections are a well-described complication of AIDS . However, relatively few reports have described infections due to Pseudomonas aeruginosa in adults who are infected with the human immunodeficiency virus (HIV) . Seven cases of serious P . aeruginosa infection in HIV-infected patients occurred during 12 months in two hospitals in Houston, often in the absence of other host factors that are generally thought to predispose to this condition . One patient had no prior illness or antibody test results that were suggestive of HIV infection; for two other patients who were known to have antibody to HIV, an AIDS-defining diagnosis had never been made . Three patients had pneumonia (two with bacteremia and one with empyema), one had malignant otitis externa, and three had bacteremia that either resulted from or caused secondarily a soft-tissue focus of infection . Two patients died, and two others experienced one or more relapses after an initial course of treatment . Compromised host defense mechanisms, including loss of mucosal integrity, defects in humoral and cellular immunities, and qualitative or quantitative leukocyte abnormalities, may predispose HIV-infected patients to P . aeruginosa infections.

APMIS, 1992 Feb, 100(2), 175 - 80
Lipopolysaccharide is present in immune complexes isolated from sputum in patients with cystic fibrosis and chronic Pseudomonas aeruginosa lung infection; Kronborg G et al.; Sputum samples from seven patients with cystic fibrosis and chronic P . aeruginosa lung infection were investigated for immune complexes by PEG precipitation and in two different complement binding assays . All seven patients were immune complex positive . The components involved in immune complex formation were identified by SDS-PAGE and immunoblotting . We found P . aeruginosa lipopolysaccharide as a major antigen . Both core and O-specific saccharide antigens could be demonstrated . IgG and IgA were the immunoglobulins involved, with IgG2 as the dominating IgG subclass . Lipopolysaccharide has a number of biological activities and its presence in sputum may have consequences for the pathogenesis of lung disease in cystic fibrosis.

Zentralbl Hyg Umweltmed, 1992 Feb, 192(5), 432 - 7
The assessment of the bactericidal activity of surface disinfectants . IV . The AOAC use-dilution method and the Kelsey-Sykes test; Reybrouck G; The AOAC use-dilution method was applied in order to assess the bactericidal activity of 29 commercial preparations for surface disinfection and the Kelsey-Sykes test under clean conditions for 38 preparations . The results of both tests are compared with those of the in vitro test (with the disinfectant diluted in distilled water, in water of standardized hardness, and in a 0.2% albumin solution), those of the European suspension test under clean and under dirty conditions, and those of four practical tests (the AFNOR test, the DGHM test, the QCT and the QSDT) . Both the AOAC use-dilution method and the Kelsey-Sykes test under clean conditions are more severe than the suspension tests and, in the case of Pseudomonas aeruginosa, even than most practical tests . The results of both tests correlate well to one another, and to the results of in vitro test, but less to those of the European suspension test . For the practical tests the correlation depends on the testing technique and on the test organism.

Mol Microbiol, 1992 Feb, 6(3), 337 - 44
Zinc and iron regulate translation of the gene encoding Pseudomonas aeruginosa elastase; Brumlik MJ et al.; A lasB-lacZ translational fusion (pTS400) was used to examine expression of the elastase gene (lasB) in Pseudomonas aeruginosa strain PAO1 . Expression from the lasB-lacZ fusion was enhanced when PAO1(pTS400) was grown in a defined medium containing elevated levels of zinc (6.0 micrograms ml-1) . Transcript accumulation studies on PAO1(pTS400) and PAO1 showed that the addition of zinc had a slight negative effect on lasB transcription . These results indicated that zinc regulates the expression of elastase at the translational level . A comparison between zinc regulation and iron regulation was also made . Iron has a negative effect on lasB-lacZ expression . When PAO1(pTS400) was grown in a defined medium with a low iron content (0.1 microgram ml-1) the bacteria still responded to zinc . The independent effects of low iron and high zinc concentrations suggest separate control mechanisms for the two factors . Transcript accumulation studies on PAO1 and PAO1 (pTS400) indicated that early in the growth curve iron did not influence transcription of lasB or lasB-lacZ . Later in the growth curve a slight increase in lasB-lacZ transcription was observed only in PAO1(pTS400) grown in low iron . These results suggest that the iron regulation of lasB occurs predominantly at the translational level . Finally, when PAO1(pTS400) was grown in a complex peptone-based medium, a high level of transcript accumulation accounted for elastase expression . Alterations of iron and zinc concentrations of this medium did not affect the expression of elastase . These results suggest that there may be additional environmental cues regulating lasB transcription.

Thorax, 1992 Feb, 47(2), 109 - 11
Seasonal onset of initial colonisation and chronic infection with Pseudomonas aeruginosa in patients with cystic fibrosis in Denmark; Johansen HK et al.; BACKGROUND AND METHODS: To assess the relation between seasonal variation and the onset of initial and chronic Pseudomonas aeruginosa infection, 300 Danish patients with cystic fibrosis were investigated . A retrospective analysis based on case reports was performed to identify the date and year of initial and chronic P aeruginosa infection from 1965 to 1990 . RESULTS: Sixty six per cent of the patients contracted their initial P aeruginosa colonisation and 68% contracted chronic infection during the winter months (October to March) . Despite major changes in treatment, including improved and intensified antibiotic treatment, during the investigation period in our cystic fibrosis centre, the seasonal difference in P aeruginosa infection persisted . CONCLUSIONS: As respiratory virus infections have the same seasonal distribution in Denmark such infections may pave the way for P aeruginosa and thus explain the parallel seasonal occurrence of this pathogen in patients with cystic fibrosis.

Am J Respir Cell Mol Biol, 1992 Feb, 6(2), 207 - 11
In vitro tumor necrosis factor-alpha secretion by monocytes from patients with cystic fibrosis; Elborn JS et al.; Immunoreactive tumor necrosis factor-alpha (TNF-alpha) concentration is increased in plasma from patients with cystic fibrosis and chronic Pseudomonas aeruginosa pulmonary infection . To determine if circulating monocytes could be the source of plasma TNF-alpha, we determined in vitro basal and endotoxin-stimulated TNF-alpha secretion by monocytes . In 10 adult patients studied at the time of a symptomatic respiratory exacerbation, basal secretion of TNF-alpha was significantly less than that for 10 matched healthy controls (median 265 pg/micrograms DNA, nonparametric 95% confidence interval 193 to 463 pg/micrograms DNA versus 575, 298 to 923 pg/micrograms DNA; P less than 0.006), although both groups responded equally effectively to added Escherichia coli endotoxin at greater than or equal to 25 ng/ml . In six patients and six matched controls, monocyte culture was repeated after completion of 2 wk anti-pseudomonal antibiotic treatment in the patients . The reduced basal TNF-alpha secretion in the patients had reversed and was not significantly different to that of controls . This effect mirrored a significant reduction in plasma immunoreactive TNF-alpha in these patients (mean +/- SD, 258 +/- 59.3 pg/ml pretreatment versus 133 +/- 47.8 pg/ml post-treatment; P less than 0.05) . These findings suggest that a reversible downregulation of TNF-alpha secretion occurred at the time of a symptomatic respiratory deterioration in the presence of chronic P . aeruginosa infection . This may represent a physiologic regulatory mechanism to maintain a local inflammatory response to chronic pulmonary infection in cystic fibrosis.

Arch Surg, 1992 Feb, 127(2), 138 - 44; discussion 144-5
Monoclonal antibody to tumor necrosis factor alpha attenuates cardiopulmonary dysfunction in porcine gram-negative sepsis; Walsh CJ et al.; Tumor necrosis factor (TNF) is implicated in the pathophysiology of gram-negative sepsis . This study examined physiologic and biochemical effects of pretreatment with an anti-TNF alpha monoclonal antibody immediately before the onset of sepsis . Three groups of anesthetized ventilated pigs were studied for 300 minutes . Groups 1 (n = 12) and 2 (n = 6) received a 1-hour infusion of live Pseudomonas aeruginosa . Group 2 was pretreated with anti-TNF alpha monoclonal antibody (15 mg/kg) . Group 3 (n = 8) received intravenous sterile saline . Group 1 exhibited a significant rise in plasma TNF activity, which was abolished in group 2 . Cardiac index was reduced in both groups 1 and 2 in the first hour but recovered in group 2 (3.3 +/- 0.4 l/min per square meter at 300 minutes in group 2 vs 1.3 +/- 0.2 L/min per square meter in group 1) . Metabolic acidosis was attenuated (arterial pH, 7.39 +/- 0.01 in group 2 vs 7.16 +/- 0.03 at 300 minutes in group 1) . Increased extravascular lung water was also attenuated (5.9 +/- 0.7 in group 2 vs 13.2 +/- 1.5 mL/kg at 300 minutes in group 1) . However, pulmonary hypertension and hypoxemia, which are known cyclooxygenase effects, were not affected . In the early phase of the study, plasma thromboxane B2 levels were elevated in both groups 1 and 2 . We conclude that anti-TNF alpha monoclonal antibody offered significant protection against the effects of sepsis, but that other mediators may be responsible for the early changes seen in this model.

Mol Gen Genet, 1992 Feb, 231(3), 417 - 25
Mutations affecting regulation of the anabolic argF and the catabolic aru genes in Pseudomonas aeruginosa PAO; Itoh Y et al.; The nucleotide sequence required for a fully functional promoter and operator of the Pseudomonas aeruginosa argF gene (argFpo), the arginine-repressible gene for anabolic ornithine carbamoyltransferase, was defined within a 160 bp region . The streptomycin (Sm) resistance genes strAB of plasmid RSF1010 were fused to argFpo . This construct in P . aeruginosa strain PAO conferred resistance to Sm . Mutants of strain PAO were selected which were resistant to Sm in the presence of arginine due to constitutive expression of argFpo-strAB . These mutants were designated argR . They were unable to grow or grew poorly on arginine or ornithine as the sole carbon and nitrogen source . This growth defect (Aru-/Oru- phenotype) was correlated with a reduced level of N-succinylornithine aminotransferase, an enzyme participating in the major aerobic pathway for arginine and ornithine catabolism in this organism . The argR mutants were classified into four groups by transduction analysis and three argR mutations were mapped on the PAO chromosome . argR9901 and argR9902 were co-transducible with car-9 (at 1 min) and thus close to the oru-310 locus; argR9906 was localized in the oruI (= aru) gene cluster (67 min) . Some aru mutants, which have been isolated previously and which produce very low amounts of all enzymes in the arginine succinyltransferase pathway, were unable to repress the argF gene in an arginine medium . Thus, P . aeruginosa PAO appears to have multiple genes that are involved in the regulation of both the anabolic argF and the catabolic aru genes.

Farmaco, 1992 Feb, 47(2), 239 - 47
Synthesis and antimicrobial activity of 1,3,4-triaryl-2-azetidinones; Diurno MV et al.; A set of substituted 1,3,4-triaryl-2-azetidinones were synthesized and characterized . Their antimicrobial activity, against Gram+ and Gram- bacteria and Fungi, was tested . The compounds 23 and 30 showed remarkable activity against Pseudomonas aeruginosa.

J Antimicrob Chemother, 1992 Feb, 29(2), 137 - 9
The IC50: an exactly defined measure of antibiotic sensitivity; Soothill JS et al.; The concentration of gentamicin that inhibits the growth of half of an inoculum of Pseudomonas aeruginosa (IC50) was estimated by doing viable bacterial counts with varying concentrations of gentamicin and fitting a probit inhibition curve to the results . This is a more precisely defined measure than the MIC and its standard error is readily calculable.

J Leukoc Biol, 1992 Feb, 51(2), 97 - 102
Effects of Pseudomonas aeruginosa rhamnolipids on human monocyte-derived macrophages; McClure CD et al.; Pseudomonas aeruginosa, a major opportunistic gram-negative pathogen, produces and secretes two heat-stable hemolytic glycolipids, a monorhamnolipid and a dirhamnolipid . In this paper a simplified method for the isolation of these rhamnolipids is described . The effect of these two rhamnolipids, both together and individually, on the viability and structural morphology of human monocyte-derived macrophages (MDMs) was examined . These cells were found to be very susceptible to the cytolytic activity of the rhamnolipids, particularly the dirhamnolipid . The monorhamnolipid, although not as cytolytic as the dirhamnolipid, caused extensive blebbing of the MDM plasma membrane . Comparison studies with several detergents confirmed the different yet distinct detergent-like activity of each rhamnolipid form . At sublethal doses, the rhamnolipids produced marked cellular distortions of the MDMs and inhibited the ability of these cells to bind and/or ingest preopsonized bacteria . The potential mechanism of action of these rhamnolipids on the MDM membranes is discussed, as well as the possible significance of these extracellular bacterial glycolipids as a virulence factor in the pathogenesis of P . aeruginosa.

Eur J Clin Microbiol Infect Dis, 1992 Feb, 11(2), 177 - 80
Evaluation of the E test in testing susceptibility of Pseudomonas aeruginosa to tobramycin; Rautelin H et al.; The E test, a new technique for measuring MICs of antimicrobial agents with the ease of disc diffusion tests, was evaluated in testing the susceptibility of 94 clinical isolates of Pseudomonas aeruginosa to tobramycin . The use of the E test was found acceptable; 93% of the MIC results were within one log2 dilution step and 100% were within two log2 dilution steps when the MICs obtained by the E test were compared to those obtained by the conventional agar dilution method . When the E test was compared to the broth microdilution method the corresponding figures were 84% and 100%, respectively.

Eur J Clin Microbiol Infect Dis, 1992 Feb, 11(2), 170 - 5
Differential effects of bismuth and salicylate salts on the antibiotic susceptibility of Pseudomonas aeruginosa; Domenico P et al.; The influence of salicylate or bismuth salts on antibiotic action against Pseudomonas aeruginosa was assessed in broth cultures . Sodium salicylate (2.5 mM) had no significant effect on the activity of any antibiotic tested . In contrast, bismuth compounds (0.5 mM) produced a significant change in the inhibitory activity of several antibiotics against all strains . Bismuth salts reduced imipenem activity by up to 20-fold, enhanced gentamicin or amikacin activity three to five-fold, and enhanced cefpirome or cefepime activity by as much as 10-fold against antibiotic-sensitive and resistant strains . Bismuth salts had little effect on cefoperazone, ceftazidime, or mezlocillin activity . Combining bismuth salts with aminoglycosides or fourth-generation cephalosporin antibiotics may help to combat the growing problem of resistant Pseudomonas aeruginosa.

Zhonghua Jie He He Hu Xi Za Zhi, 1992 Feb, 15(1), 8 - 10, 60
{Rapid diagnosis of pulmonary Pseudomonas aeruginosa infections by indirect immunofluorescent antibody}; Tang YC; 167 sputum specimens collected from patients with pulmonary infection were tested by IFA (Indirect immunofluorescent antibody-staining) with serogroup-specific monoclonal antibody to Pseudomonas aeruginosa, compared with quantitative sputum culture . The results showed the minimum concentration of bacteria detectable by IFA was 10 cfu/ml . 31(86.1%) were positive in 36 specimens with more than 10 cfu/ml of Pseudomonas aeruginosa . 22(100%) were positive in 22 specimens with more than 10 cfu/ml of Pseudomonas aeruginosa . In 127 specimens with a negative culture for Pseudomonas aeruginosa, 121(95.2%) were negative, 6(4.8%) were false-positive which could be identified by Gram's-staining . The type of Pseudomonas aeruginosa could also be identified within 3 hours.

Antibiot Khimioter, 1992 Feb, 37(2), 17 - 8
{Antibiotic sensitivity and pathogenetic factors of hospital strains of Pseudomonas aeruginosa isolated from patients treated in a resuscitation unit}; Gabisoniia TG et al.; Strains of Pseudomonas aeruginosa were isolated from patients treated in the Centre of Thermal Affections in 1985-1989 . It was shown that 72.9, 59.3, 33.8 and 54.2 per cent of the isolates were sensitive to cefotaxime, tobramycin, gentamicin and polymyxin, respectively . The study of pathogenicity factors of the isolates revealed that 83 per cent of the strains produced thermolabile enterotoxin, 79.6 per cent of the strains had adhesive activity and 71.1 per cent of the strains produced hemolysin . The study detected combinations of various pathogenicity factors . 42.3 per cent of the isolates had both adhesive and enterotoxigenic properties . Adhesiveness and hemolytic activity were shown by 13.5 per cent of the strains . 16.9 per cent of the strains produced both enterotoxin and hemolysin . Adhesive activity, enterotoxigenicity and hemolysin production were observed in 6.7 per cent of the strains . It was noted that the strains of P . aeruginosa resistant to polymyxin mainly produced enterotoxin (18.6 per cent) and those resistant to cefotaxime had adhesive activity (34.0 per cent).

Arch Dis Child, 1992 Feb, 67(2), 192 - 5
Controlled study of Pseudomonas cepacia and Pseudomonas maltophilia in cystic fibrosis; Gladman G et al.; In a retrospective study, children with cystic fibrosis who were colonised with Pseudomonas cepacia were compared with a control group who were colonised with Pseudomonas maltophilia . Out of 216 children with cystic fibrosis seen between 1983 and 1990, P cepacia was recovered from 13 (median age at colonisation 12.2 years) and P maltophilia from 23 (median age at first colonisation 6.1 years), and both organisms were recovered in five cases . With the exception of two patients with P cepacia in whom no other pathogens were found, all the patients with P cepacia or P maltophilia had co-colonisation with Pseudomonas aeruginosa . The lack of spread of P cepacia to siblings with cystic fibrosis, and the relative lack of inpatient contact between colonised and uncolonised patients suggest that cross infection is not the sole route whereby patients with cystic fibrosis become infected, but the possibility of cross infection cannot be excluded from our data . Three patients with P cepacia died, but two of these had shown appreciable respiratory deterioration before colonisation with P cepacia; there was no evidence of unexpected deterioration in the remainder or in the controls with P maltophilia . By 1990, the prevalence of P cepacia was 9/133 (7%) and that of P maltophilia was 13/133 (10%), but it was impossible to determine to what extent this increase was due to the introduction of the routine use of selective media . Further studies are required to establish whether patients with and without P cepacia should be segregated.

J Clin Invest, 1992 Feb, 89(2), 648 - 56
Binding of Pseudomonas cepacia to normal human intestinal mucin and respiratory mucin from patients with cystic fibrosis; Sajjan US et al.; Although not as prevalent as Pseudomonas aeruginosa, Pseudomonas cepacia is another opportunistic pathogen which colonizes the lungs of at least some patients with cystic fibrosis . A subgroup of these patients exhibits the "cepacia syndrome", i.e., a rapid clinical deterioration and death within one year . To investigate potential early sites of bacterial attachment, we have measured the specific binding of P . cepacia isolates from cystic fibrosis (CF) sputa to both CF and non-CF mucins purified from respiratory and intestinal secretions, respectively . As shown in microtiter binding assays, clinical isolates from 19/22 patients were found to bind to both mucins, with the highest specific binding exhibited by isolates from eight patients, seven of whom later died with the cepacia syndrome . No differences were observed in the binding capacity of the two (CF versus non-CF) mucins . Binding was specific, saturable, and not influenced by tetramethylurea, a disruptor of hydrophobic associations . Individual sugars were ineffective as hapten inhibitors, as were several lectins . Mucins treated by reduction/alkylation or chloroform/methanol extraction showed enhanced bacterial binding, findings which were attributed to exposure of underlying binding sites . Deglycosylation procedures indicated that mucin receptors for P . cepacia include N-acetylglucosamine and N-acetylgalactosamine, probably linked together as part of core oligosaccharide structures . P . cepacia isolates also bound to buccal epithelial cells, and mucin partially inhibited the binding of those isolates of P . cepacia that also had the ability to bind to mucin . We speculate that specific binding of P . cepacia to secreted mucins may be an early step in the pathogenesis of the cepacia syndrome.

Gan To Kagaku Ryoho, 1992 Feb, 19(2), 178 - 83
{Clinical approach to infection in patients with hematologic malignancy}; Funada H; Patients with hematologic malignancy are susceptible to infection because of the disease process and its treatment . Profoundly granulocytopenic patients are at increased risk of developing Pseudomonas aeruginosa bacteremia, often with a fatal outcome . Therapy with one or two anti-pseudomonal beta-lactam antibiotics and an aminoglycoside in combination that were effective in vitro against the infecting organism proved to be superior, by one-week survival, to therapy with either one in vitro effective beta-lactam or aminoglycoside or inadequate drugs . On the other hand, treatment with granulocyte colony-stimulating factor had no significant association with longer survival, although a favorable outcome was well correlated with an increase in the granulocyte count during therapy . An active mycobacteriosis was documented in 2% of all patients with hematologic malignancy . Dissemination occurred in half of them . The prognosis of tuberculosis was depended mainly on early diagnosis and treatment, while that for the atypical variety was largely influenced by the underlying disease . The frequency of deep fungal infection in patients with acute leukemia at autopsy increased progressively from 10% in 1970-1974 to 38% in 1983-1986, but it decreased somewhat to 29% in 1987-1989 after the introduction of empiric amphotericin B therapy in 1986 . Early empiric antifungal therapy should therefore be started in granulocytopenic patients with fever refractory to antibacterial therapy, because of unreliability of the current serodiagnosis . A total protective isolation for patients undergoing bone marrow transplantation (BMT) was associated with a reduced incidence of pneumonia, especially due to Aspergillus, and to a lesser extent, bacteremia . Cytomegalovirus pneumonia complicating BMT continues to have a poor prognosis, although the frequency has gradually been decreasing with the introduction of effective preventive measures . An early diagnosis and treatment as well as preventive measures is thus necessary for infection control in patients with hematologic malignancy.

J Formos Med Assoc, 1992 Feb, 91(2), 190 - 4
Pseudomonas aeruginosa isolated from corneal ulcer: susceptibility to antimicrobial agents tested alone or in combination; Hu FR et al.; Twenty-eight isolates of P . aeruginosa from corneal ulcers were tested for their susceptibility to 19 antimicrobial agents by an agar dilution method . The effect of a combination of an aminoglycoside with a beta-lactam, ciprofloxacin or colistin was checked by the checkerboard titration method . The minimal inhibitory concentrations (MICs) of these antimicrobial agents varied greatly . The MICs of aminoglycosides were near the breakpoint value of the usual susceptibility definition in most tested strains, but some were highly resistant . Ciprofloxacin, imipenem, aztreonam, ceftazidime, cefoperazone, piperacillin and colistin were other effective drugs with low MICs . Piperacillin, ceftazidime or aztreonam in combination with gentamicin or amikacin revealed a synergistic effect, but antagonism was found with ciprofloxacin or colistin combined with gentamicin or amikacin . Considering the difference in drug concentration achievable between systemic administration and topical application, the MIC quantitative determinations and the combination effect of antimicrobial agents against ocular isolates could provide useful information to ophthalmologists in choosing drugs for treatment of P . aeruginosa ocular infections.

J Hosp Infect, 1992 Feb, 20(2), 87 - 96
Investigation of an outbreak of nosocomial infection due to a multiply drug-resistant strain of Pseudomonas aeruginosa; Rossello J et al.; A nosocomial outbreak of Pseudomonas aeruginosa infections which occurred in the Urology Service of a large city hospital was studied . A case-control methodology was used to analyse patients' characteristics and the main risk factors of all cases with a positive culture during the period between March 1987 and March 1988 . The usefulness of factor analysis in the definition of a case was examined . There were 74 infections of which 35 (47.3%), had a nosocomial origin . The outbreak took place in December 1987, with a peak incidence of infections of 10.5%, compared with a 2.2% frequency during the preceding months (P less than 0.005) . Six of the nine infections occurring in that month, were caused by strains resistant to ticarcillin and gentamicin . The epidemic cases had longer hospital stays than the non-epidemic cases (P less than 0.038) and occurred more frequently in a specific area of the hospital (P less than 0.001) . The odds ratio for resistance to gentamicin was 15 (P less than 0.018) and that of resistance to ticarcillin, 127 (P less than 0.0001) . Our results suggest that inaccurate case definitions may produce misleading conclusions . Factor analysis appears to be a useful analytical tool when defining a case.

Gene, 1992 Feb 1, 111(1), 35 - 41
A two-component T7 system for the overexpression of genes in Pseudomonas aeruginosa; Brunschwig E et al.; A two-component T7 expression system was developed for efficient expression of genes in the nonenteric bacterium, Pseudomonas aeruginosa . The first component of the expression system is a bacteriophage-based transposable element that contains a lacUV5/lacIq-regulated T7 RNA polymerase gene and a selectable antibiotic-resistance determinant . This element, designated miniD-180, was stably integrated into the P . aeruginosa PAO1 chromosome . The second component of this system includes several improved broad-host-range expression vectors containing the T7 gene 10 promoter and multiple cloning site (MCS) . These vectors (pEB8, pEB11, and pEB12) contain transcriptional terminators (T1(4)) upstream from the T7 promoter, and T7 terminators downstream from the MCS . Because the T7 promoter is somewhat leaky in these vectors, pEB14 was constructed to decrease transcription of target genes by basal levels of T7 RNA polymerase . This vector contains a core sequence of the lac operator located 19 bp downstream from the transcriptional start point of the T7 promoter, thereby providing a dually regulated system . The utility of this system was demonstrated by placing a promoterless chloramphenicol acetyltransferase (CAT) cassette under control of the T7 promoter and monitoring the isopropyl-beta-D-thiogalactopyranoside-dependent accumulation of CAT in cell-free extracts of P . aeruginosa . We observed up to nearly a 60-fold increase in CAT levels 4 h post-induction, at which time this polypeptide represented up to 20% of the total soluble protein.

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