FEBS J, 2005 Jan, 272(2), 538 - 49 Degradation of chitosans with chitinase B from Serratia marcescens; Sorbotten A et al.; Family 18 chitinases such as chitinase B (ChiB) from Serratia marcescens catalyze glycoside hydrolysis via a mechanism involving the N-acetyl group of the sugar bound to the -1 subsite . We have studied the degradation of the soluble heteropolymer chitosan, to obtain further insight into catalysis in ChiB and to experimentally assess the proposed processive action of this enzyme . Degradation of chitosans with varying degrees of acetylation was monitored by following the size-distribution of oligomers, and oligomers were isolated and partly sequenced using (1)H-NMR spectroscopy . Degradation of a chitosan with 65% acetylated units showed that ChiB is an exo-enzyme which degrades the polymer chains from their nonreducing ends . The degradation showed biphasic kinetics: the faster phase is dominated by cleavage on the reducing side of two acetylated units (occupying subsites -2 and -1), while the slower kinetic phase reflects cleavage on the reducing side of a deacetylated and an acetylated unit (bound to subsites -2 and -1, respectively) . The enzyme did not show preferences with respect to acetylation of the sugar bound in the +1 subsite . Thus, the preference for an acetylated unit is absolute in the -1 subsite, whereas substrate specificity is less stringent in the -2 and +1 subsites . Consequently, even chitosans with low degrees of acetylation could be degraded by ChiB, permitting the production of mixtures of oligosaccharides with different size distributions and chemical composition . Initially, the degradation of the 65% acetylated chitosan almost exclusively yielded oligomers with even-numbered chain lengths . This provides experimental evidence for a processive mode of action, moving the sugar chain two residues at a time . The results show that nonproductive binding events are not necessarily followed by substrate release but rather by consecutive relocations of the sugar chain. Biopolymers . 2005 Jan 6; {Epub ahead of print} Development and application of a model for chitosan hydrolysis by a family 18 chitinase; Sikorski P et al.; Hydrolysis of partially deacetylated chitosans by ChitinaseB (ChiB) from Serratia marcescens results in mixtures of oligosaccharides typically between 2 and 20 sugar residues . The amounts of different oligomer fractions depend on the degree of acetylation of the starting chitosans . We have used experimentally determined distributions of hydrolysis products to develop a model for chitosan hydrolysis by ChiB . Important elements of the model include interaction parameters for acetylated/deacetylated units in each of the six subsites in the active cleft, and degree of processivity (multiple attack) . The hydrolysis reaction is described as a chemical reaction with an activation barrier that depends on the substrate sequence presented to the enzyme subsites . Using "Monte Carlo" approach, the interaction parameters were refined by minimising the difference between observed and predicted amounts of hydrolysis products obtained upon degradation of chitosan with a degree of acetylation of 65% . The final model can accurately predict complex patterns of oligosaccharides produced in the hydrolysis of chitosans with various degrees of acetylation, as well as patterns observed during reactions with chito-oligosaccharides . The behaviour of a ChiB mutant with a mutation in subsite +2 (Gly188Asp) which reduces affinity for an acetylated sugar, could be predicted correctly by introducing one single change in the model parameters (the interaction energy for an acetylated unit in +2 subsite) . The proposed model may be used to explore degradation products for different enzyme-substrates combinations and optimise conditions for preparation of specific oligosaccharides . In addition, the model provides insight into subsite interaction parameters and the degree of processivity, which complements previous experimental studies on the mode of action of ChiB . (c) 2005 Wiley Periodicals, Inc . Biopolymers, 2005. Wilderness Environ Med, 2004 Winter, 15(4), 245 - 9 Coliform and pathologic bacteria in Sierra Nevada national forest wilderness area lakes and streams; Derlet RW et al.; OBJECTIVE: To analyze backcountry-area water quality in US Department of Agriculture Forest Service-designated wilderness areas for the presence of coliform and potentially pathogenic bacteria . METHODS: Thirty-one backcountry lakes and streams were selected that would stratify the risk based on use by backpackers, pack animals, commercial grazing animals, or natural unaffected wilderness areas . Sites included Desolation Wilderness (10 sites), Carson-Iceberg Wilderness (4 sites), Emigrant Wilderness (3 sites), Hoover Wilderness (6 sites), John Muir Wilderness (3 sites), and Golden Trout Wilderness (5 sites) . Water was collected in sterile tubes and quantification was performed through Millipore bacterial samplers . On return to the laboratory, bacteria were harvested from the samplers and subjected to qualitative analysis that identified species according to standard laboratory methods . RESULTS: Coliform bacteria were detected in 14 of 31 sites (45%) . Eight sites had high levels of coliforms . All 8 of these sites correlated with heavy human use or commercial grazing . Coliforms were identified as Escherichia coli . In addition, 1 sample contained Yersinia entercolitica . All samples contained expected amounts of normal aquatic bacteria, including Pseudomonas spp, Rahnella aquatilis, Serratia spp, and other nonpathogenic species of Yersinia in concentrations of 600 to 10,000 colony-forming units per 100 mL . CONCLUSIONS: In this study, coliform bacteria were found at nearly half of the sampling sites . High coliform levels correlated with high-impact human use or cattle grazing. Wilderness Environ Med, 2004 Winter, 15(4), 238 - 44 An analysis of wilderness water in Kings Canyon, Sequoia, and Yosemite national parks for coliform and pathologic bacteria; Derlet RW et al.; OBJECTIVE: To determine the prevalence of coliform and potentially pathogenic bacteria in remote backcountry alpine lakes and streams of national parks in the Sierra Nevada mountains . METHODS: Water was sampled at 55 predetermined lakes and streams that would stratify the risk, based on sites used by backpackers, sites used by pack animals, and uncontaminated wild areas . Sites were distributed among Kings Canyon (15), Sequoia (17), and Yosemite (23) . Water was collected using Millipore bacterial samplers, which provided specific counts of coliform and other bacteria in each water sample and also served as a transport media from the wilderness to the laboratory . On return to the laboratory, bacteria were harvested from the samplers and subjected to specific identification and qualitative analysis using standard microbiology techniques for the analysis of water . RESULTS: Coliform bacteria were detected in 22 of the 55 sites . All of these sites were below areas used by backpackers or pack animals . Thirty-three sites were free of coliforms . These sites included both those used lightly by backpackers and those with no human or domestic animal use . All samples contained expected amounts of normal aquatic bacteria including Pseudomonas, Rahnella aquatilis, Serratia spp, and nonpathogenic species of Yersinia . CONCLUSIONS: Most sampling sites in these national parks are free of coliform or pathogenic organisms . Low levels of coliform bacteria are found in some bodies of water where the watershed has been affected by human or pack animal travel. J Food Prot, 2004 Dec, 67(12), 2760 - 6 Performance comparison of the BioSys optical assay and the violet red bile agar method for detecting coliforms in food products; Firstenberg-Eden R et al.; Coliform counts in a variety of foods, including dairy products (raw milk, pasteurized milk, yogurt, butter, and ice cream), meats (pork sausage, ground beef, and raw chicken), raw eggs, and chocolate, were performed by the rapid automated BioSys optical assay and the conventional method with violet red bile agar (VRBA) . The standard deviation (SD) among five replicate counts for the optical assay was similar to or better than that obtained with VRBA plates for all foods tested . The average SD for all foods tested was 0.21 for the optical assay and 0.30 for the VRBA plates . At very low concentrations of coliforms (1 to 10 CFU/ml for liquid products and 10 to 100 CFU/g for solid samples), the average SDs were 0.26 and 0.47, respectively . The optical assay was less susceptible to interference by noncoliform organisms . In naturally contaminated samples, bacteria such as Serratia liquefaciens, Pantoea spp., Vibrio fluvialis, Aeromonas hydrophilia, and Pseudomonas spp . formed typical colonies in VRBA, resulting in false-positive results or a need to verify colonies in brilliant green lactose broth . The optical assay appeared to be more selective than the VRBA conventional method, detecting fewer noncoliforms . There was close agreement in test results between the two methods, as indicated by correlation coefficients of 0.92 to 0.99 obtained for the regression analysis of the two methods . In most cases both methods distinguished accurately between positive samples containing coliforms and negative controls . All products tested using the automated BioSys Optical Assay for coliforms yielded results more quickly (typically 10 to 12 h) than did those tested with the conventional VRBA method (24 to 72 h with confirmation). Ocul Immunol Inflamm, 2004 Dec, 12(4), 287 - 95 Induction of cytokines from polymorphonuclear leukocytes and epithelial cells by ocular isolates of Serratia marcescens; Hume E et al.; Purpose: During contact lens wear, bacterial contamination of the lens can lead to the development of microbial keratitis (MK) or contact lens induced acute red eye (CLARE) . Inflammatory mediators released by the host may heighten the response . We have examined the ability of human corneal epithelial cells and polymorphonuclear leukocytes (PMNs) to release cytokines upon stimulation with bacteria . Methods: Serratia marcescens strains were added to corneal epithelial cells or PMNs . After incubations of up to 20 hours, supernatants were assayed for the presence of inflammatory mediators by ELISA . Results: All strains stimulated PMNs to release IL-8 and LTB(4) . Epithelial cells did not release LTB(4) . IL-8 was released after exposure to most S . marcescens isolates . A sub-group of strains stimulated the release of TNF-alpha from corneal epithelial cells . Conclusions: S . marcescens can stimulate the release of inflammatory mediators from both PMNs and corneal epithelial cells . This release could be important in the progression and resolution of MK and CLARE. Biotechnol Lett, 2004 Nov, 26(22), 1723 - 1730 Synthesis of nanophase hydroxyapatite by a Serratia sp . from waste-water containing inorganic phosphate; Yong P et al.; Synthesis of nanophase hydroxyapatite (HA) on a bacterial surface was achieved at the expense of CaCl(2) and inorganic phosphate (Pi) . After initial nucleation, calcium was precipitated on and around the cells as calcium phosphate at the expense of inorganic phosphate in the challenge solution, with no precipitation in cell-free controls . HA was also biomanufactured using inorganic phosphate ions scavenged from a phosphate-containing waste-water . With additional Ca(2+), the concentration of phosphate was decreased from 0.27 ( approximately 25 ppm) to approximately 0.02m ( approximately 2 ppm) in the waste-water . Crystals of calcium phosphate manufactured by the cells were located by scanning electron microscopy (SEM) and identified as HA by X-ray powder diffraction, with an average crystal size calculated as approximately 25 nm . Possible application of bioHA as a biomaterial and implications for one-step `waste-into product' are discussed. Biotechnol Lett, 2004 Nov, 26(21), 1643 - 8 Oxidation of heterocyclic and aromatic aldehydes to the corresponding carboxylic acids by Acetobacter and Serratia strains; Mitsukura K et al.; Conversion of heterocyclic and aromatic aldehydes to the corresponding carboxylic acids was carried out using Acetobacter rancens IFO3297, A . pasteurianus IFO13753 and Serratia liquefaciens LF14 . IFO3297 produced 110g 2-furoic acid l(-1) from furfural with a 95% molar yield . 5-Hydroxymethyl-2-furancarboxylic acid was produced from the corresponding aldehyde by using whole cells LF14 . IFO13753 and LF14 both converted isophthalaldehyde, 2,5-furandicarbaldehyde, 2,5-thiophenedicarbaldehyde and 2,2' biphenyldicarbaldehyde to the corresponding formylcarboxylic acid with 86--91% molar yields. J Biol Chem . 2004 Dec 8; {Epub ahead of print} Crystal structure and binding properties of the Serratia marcescens chitin-binding protein CBP21; Vaaje-Kolstad G et al.; Chitin proteins (CBPs) are commonly found in bacteria that utilize chitin as a source of energy . CBP21 is a chitin binding protein from Serratia marcescens, a Gram-negative soil bacterium capable of efficient chitin degradation . When grown on chitin, Serratia marcescens secretes large amounts of CBP21, along with chitin degrading enzymes . In an attempt to understand the molecular mechanism of CBP21 action, we have determined its crystal structure at 1.55 A resolution . This is the first structure of a family 33 carbohydrate binding module to be solved . The structure reveals a "budded" fibronectin type III fold, consisting of two b-sheets, arranged as a b-sheet sandwich, with a 65-residue "bud", consisting of three short helices, located between b-strands 1 and 2 . Remarkably, conserved aromatic residues that have previously been suggested to play a role in chitin binding were mainly found in the interior of the protein, seemingly incapable of interacting with chitin, whereas the structure reveals a surface patch of highly conserved, mainly hydrophilic residues . The roles of six of these conserved surface-exposed residues (Tyr54, Glu55, Glu60, His114, Asp182, Asn185) were probed by site-directed mutagenesis and subsequent binding studies . All single point mutations lowered the affinity of CBP21 for b-chitin, as shown by three- to eight-fold increases in the apparent binding constant . Thus, binding of CBP21 to chitin seems to be mediated primarily by conserved, solvent exposed, polar side chains. J Biol Chem . 2004 Dec 2; {Epub ahead of print} Novel, anion-independent iron coordination by members of a third class of bacterial periplasmic Ferric Ion-binding proteins; Shouldice SR et al.; The uptake of the element iron is vital for the survival of most organisms . Numerous pathogenic Gram-negative bacteria utilize a periplasm-to-cytosol ATP-binding cassette transport pathway in order to transport this essential atom in to the cell . In this study, we investigated the Yersinia enterocolitica (YfuA) and Serratia marcescens (SfuA) iron-binding periplasmic proteins . We have determined the 1.8-A structures of iron-loaded (YfuA) and iron-free (SfuA) forms of this class of proteins . Although the sequence of these proteins varies considerably from the other members of the transferrin structural superfamily, they adopt the same three-dimensional fold . The iron-loaded YfuA structure illustrates the unique nature of this new class of proteins in that they are able to octahedrally coordinate the ferric ion in the absence of a bound anion . The iron-free SfuA structure contains a bound citrate anion in the iron-binding cleft that tethers the N- and C-terminal domains of the apo protein and stabilizes the partially open structure. Biol Chem, 2004 Nov, 385(11), 1007 - 16 Role of bacterial proteases in pseudomonal and serratial keratitis; Matsumoto K; Pseudomonas aeruginosa and Serratia marcescens can cause refractory keratitis resulting in corneal perforation and blindness . These bacteria produce various kinds of proteases . In addition to pseudomonal elastase (LasB) and alkaline protease, LasA protease and protease IV have recently been found to be more important virulence factors of P . aeruginosa . S . marcescens produces a cysteine protease in addition to metalloproteases . These bacterial proteases have a number of biological activities, such as degradation of tissue constituents and host defense-oriented proteins, as well as activation of zymogens (Hageman factor, prekallikrein and pro-matrix metalloproteinases) through limited proteolysis . In this article, the properties of these bacterial proteases are reviewed and the pathogenic roles of these proteases in pseudomonal keratitis are discussed. Nucleic Acids Res, 2004, 32(20), 6129 - 35 Print 2004. Type II restriction endonuclease R.KpnI is a member of the HNH nuclease superfamily; Saravanan M et al.; The restriction endonuclease (REase) R.KpnI is an orthodox Type IIP enzyme, which binds to DNA in the absence of metal ions and cleaves the DNA sequence 5'-GGTAC--C-3' in the presence of Mg2+ as shown generating 3' four base overhangs . Bioinformatics analysis reveals that R.KpnI contains a betabetaalpha-Me-finger fold, which is characteristic of many HNH-superfamily endonucleases, including homing endonuclease I-HmuI, structure-specific T4 endonuclease VII, colicin E9, sequence non-specific Serratia nuclease and sequence-specific homing endonuclease I-PpoI . According to our homology model of R.KpnI, D148, H149 and Q175 correspond to the critical D, H and N or H residues of the HNH nucleases . Substitutions of these three conserved residues lead to the loss of the DNA cleavage activity by R.KpnI, confirming their importance . The mutant Q175E fails to bind DNA at the standard conditions, although the DNA binding and cleavage can be rescued at pH 6.0, indicating a role for Q175 in DNA binding and cleavage . Our study provides the first experimental evidence for a Type IIP REase that does not belong to the PD...D/EXK superfamily of nucleases, instead is a member of the HNH superfamily. Braz J Med Biol Res, 2004 Dec, 37(12), 1763 - 9 Epub 2004 Dec. A role for histone-like protein H1 (H-NS) in the regulation of hemolysin expression by Serratia marcescens; Franzon JH et al.; The histone-like protein H1 (H-NS) is an abundant structural component of the bacterial nucleoid and influences many cellular processes including recombination, transcription and transposition . Mutations in the hns gene encoding H-NS are highly pleiotropic, affecting the expression of many unrelated genes . We have studied the role of H-NS on the regulation of hemolysin gene expression in Serratia marcescens . The Escherichia coli hns mutant carrying S . marcescens hemolysin genes on a plasmid constructed by ligation of the 3.2-kb HindIII-SacI fragment of pR02 into pBluescriptIIKS, showed a high level of expression of this hemolytic factor . To determine the osmoregulation of wild-type and hns defective mutants the cells were grown to mid-logarithmic phase in LB medium with 0.06 or 0.3 M NaCl containing ampicillin and kanamycin, whereas to analyze the effect of pH on hemolysin expression, the cells were grown to late-logarithmic phase in LB medium buffered with 0.1 M Tris-HCl, pH 4.5 to 8.0 . To assay growth phase-related hemolysin production, bacterial cells were grown in LB medium supplemented with ampicillin and kanamycin . The expression of S . marcescens hemolysin genes in wild-type E . coli and in an hns-defective derivative at different pH and during different growth phases indicated that, in the absence of H-NS, the expression of hemolysin did not vary with pH changes or growth phases . Furthermore, the data suggest that H-NS may play an important role in the regulation of hemolysin expression in S . marcescens and its effect may be due to changes in DNA topology influencing transcription and thus the amount of hemolysin expression . Implications for the mechanism by which H-NS influences gene expression are discussed. BMC Evol Biol . 2004 Nov 22;4(1):49. Diversity and specificity in the interaction between Caenorhabditis elegans and the pathogen Serratia marcescens; Schulenburg H et al.; BACKGROUND: Co-evolutionary arms races between parasites and hosts are considered to be of immense importance in the evolution of living organisms, potentially leading to highly dynamic life-history changes . The outcome of such arms races is in many cases thought to be determined by frequency dependent selection, which relies on genetic variation in host susceptibility and parasite virulence, and also genotype-specific interactions between host and parasite . Empirical evidence for these two prerequisites is scarce, however, especially for invertebrate hosts . We addressed this topic by analysing the interaction between natural isolates of the soil nematode Caenorhabditis elegans and the pathogenic soil bacterium Serratia marcescens . RESULTS: Our analysis reveals the presence of i) significant variation in host susceptibility, ii) significant variation in pathogen virulence, and iii) significant strain- and genotype-specific interactions between the two species . CONCLUSIONS: The results obtained support the previous notion that highly specific interactions between parasites and animal hosts are generally widespread . At least for C . elegans, the high specificity is observed among isolates from the same population, such that it may provide a basis for and/or represent the outcome of co-evolutionary adaptations under natural conditions . Since both C . elegans and S . marcescens permit comprehensive molecular analyses, these two species provide a promising model system for inference of the molecular basis of such highly specific interactions, which are as yet unexplored in invertebrate hosts. J Ind Microbiol Biotechnol . 2004 Nov 11; {Epub ahead of print} Optimization of Serratia marcescens lipase production for enantioselective hydrolysis of 3-phenylglycidic acid ester; Gao L et al.; Lipase production and cell growth of Serratia marcescens ECU1010 were optimized in shake flasks, with lipase production being enhanced 9.5-fold (4,780 U/l) compared with the initial activity (500 U/l) . Optimal carbon and nitrogen sources were Tween-80 and peptone, and the optimal ratio of Tween-80 to peptone was 1:3 . The optimized cultivation conditions were 25 degrees C and pH 6.5 . Lipase activity, particularly specific activity, could be improved by decreasing the cultivation temperature from 35 to 25 degrees C . Enzyme stability was significantly improved by simple immobilization with synthetic adsorption resin no . 8244 . After five reaction cycles, enzyme activity decreased only very slightly, while enantioselectivity of the preparation remained constant, and the ee(s) (enantiomeric excess of the remaining substrate) achieved in all cases was higher than 97% . The resin-8244-lipase preparation can be used for efficient enantioselective hydrolysis of trans-3-(4'-methoxyphenyl)glycidic acid methyl ester {(+/-)-MPGM}, a key intermediate in the synthesis of Diltiazem. Vet Res, 2004 Nov-Dec, 35(6), 681 - 700 Innate immune response to intramammary infection with Serratia marcescens and Streptococcus uberis; Bannerman DD et al.; Streptococcus uberis and Serratia marcescens are Gram-positive and Gram-negative bacteria, respectively, that induce clinical mastitis . Once initial host barrier systems have been breached by these pathogens, the innate immune system provides the next level of defense against these infectious agents . The innate immune response is characterized by the induction of pro-inflammatory cytokines, as well as increases in other accessory proteins that facilitate host recognition and elimination of the pathogens . The objective of the current study was to characterize the innate immune response during clinical mastitis elicited by these two important, yet less well-studied, Gram-positive and Gram-negative organisms . The pro-inflammatory cytokine response and changes in the levels of the innate immune accessory recognition proteins, soluble CD14 (sCD14) and lipopolysaccharide (LPS)-binding protein (LBP), were studied . Decreased milk output, induction of a febrile response, and increased acute phase synthesis of LBP were all characteristic of the systemic response to intramammary infection with either organism . Infection with either bacteria similarly resulted in increased milk levels of IL-1 beta, IL-8, IL-10, IL-12, IFN-gamma, TNF-alpha, sCD14, LBP, and the complement component, C5a . However, the duration of and/or maximal changes in the increased levels of these inflammatory markers were significantly different for several of the inflammatory parameters assayed . In particular, S . uberis infection was characterized by the sustained elevation of higher milk levels of IL-1 beta, IL-10, IL-12, IFN-gamma, and C5a, relative to S . marcescens infection . Together, these data demonstrate the variability of the innate immune response to two distinct mastitis pathogens. Pediatr Cardiol, 2004 Sep-Oct, 25(5), 562 - 4 Epub 2004 Jun 08. Aspirin treatment for neonatal infectious endocarditis; Adler A et al.; We describe a term female neonate with Serratia marcescens endocarditis . Despite adequate antibiotic therapy for 8 days, the bacteremia persisted and there was an increase in vegetation size . Treatment with aspirin was initiated, with resolution of the bacteremia and a gradual decrease in vegetation size . We conclude that in neonatal endocarditis, aspirin may be beneficial additional treatment. Org Biomol Chem, 2004 Nov 21, 2(22), 3329 - 36 Epub 2004 Oct 13. Synthesis and stability of small molecule probes for Pseudomonas aeruginosa quorum sensing modulation; Glansdorp FG et al.; The human pathogen Pseudomonas aeruginosa uses N-butyryl-L-homoserine lactone (BHL) and N-(3-oxododecanyl)-L-homoserine lactone (OdDHL) as small molecule intercellular signals in a phenomenon known as quorum sensing (QS) . QS modulators are effective at attenuating P . aeruginosa virulence; therefore, they are a potential new class of antibacterial agent . The lactone in BHL and OdDHL is hydrolysed under physiological conditions . The hydrolysis proceeds at a rate faster than racemisation of the alpha-chiral centre . Non-hydrolysable, non-racemic analogues (small molecule probes) were designed and synthesised, replacing the lactone with a ketone . OdDHL analogues were found to be relatively unstable to decomposition unless they were difluorinated between the beta-keto amide . Stability studies on a non-hydrolysable, cyclohexanone analogue indicated that racemisation of the alpha-chiral centre was relatively slow . This analogue was assayed to show that the L-isomer is likely to be responsible for the QS autoinducing activity in P . aeruginosa and Serratia strain ATCC39006. Microbiology, 2004 Nov, 150(Pt 11), 3547 - 60 The Serratia gene cluster encoding biosynthesis of the red antibiotic, prodigiosin, shows species- and strain-dependent genome context variation; Harris AK et al.; The prodigiosin biosynthesis gene cluster (pig cluster) from two strains of Serratia (S . marcescens ATCC 274 and Serratia sp . ATCC 39006) has been cloned, sequenced and expressed in heterologous hosts . Sequence analysis of the respective pig clusters revealed 14 ORFs in S . marcescens ATCC 274 and 15 ORFs in Serratia sp . ATCC 39006 . In each Serratia species, predicted gene products showed similarity to polyketide synthases (PKSs), non-ribosomal peptide synthases (NRPSs) and the Red proteins of Streptomyces coelicolor A3(2) . Comparisons between the two Serratia pig clusters and the red cluster from Str . coelicolor A3(2) revealed some important differences . A modified scheme for the biosynthesis of prodigiosin, based on the pathway recently suggested for the synthesis of undecylprodigiosin, is proposed . The distribution of the pig cluster within several Serratia sp . isolates is demonstrated and the presence of cryptic clusters in some strains shown . The pig cluster of Serratia marcescens ATCC 274 is flanked by cueR and copA homologues and this configuration is demonstrated in several S . marcescens strains, whilst these genes are contiguous in strains lacking the pig cluster. Plasmid, 2004 Nov, 52(3), 182 - 202 The complete nucleotide sequence of the resistance plasmid R478: defining the backbone components of incompatibility group H conjugative plasmids through comparative genomics; Gilmour MW et al.; Horizontal transfer of resistance determinants amongst bacteria can be achieved by conjugative plasmid DNA elements . We have determined the complete 274,762 bp sequence of the incompatibility group H (IncH) plasmid R478, originally isolated from the Gram negative opportunistic pathogen Serratia marcescens . This self-transferable extrachromosomal genetic element contains 295 predicted genes, of which 144 are highly similar to coding sequences of IncH plasmids R27 and pHCM1 . The regions of similarity among these three IncH plasmids principally encode core plasmid determinants (i.e., replication, partitioning and stability, and conjugative transfer) and we conducted a comparative analysis to define the minimal IncHI plasmid backbone determinants . No resistance determinants are included in the backbone and most of the sequences unique to R478 were contained in a large contiguous region between the two transfer regions . These findings indicate that plasmid evolution occurs through gene acquisition/loss predominantly in regions outside of the core determinants . Furthermore, a modular evolution for R478 was signified by the presence of gene neighbors or operons that were highly related to sequences from a wide range of chromosomal, transposon, and plasmid elements . The conjugative transfer regions are most similar to sequences encoded on SXT, Rts1, pCAR1, R391, and pRS241d . The dual partitioning modules encoded on R478 resemble numerous sequences; including pMT1, pCTX-M3, pCP301, P1, P7, and pB171 . R478 also codes for resistance to tetracycline (Tn10), chloramphenicol (cat), kanamycin (aphA), mercury (similar to Tn21), silver (similar to pMG101), copper (similar to pRJ1004), arsenic (similar to pYV), and tellurite (two separate regions similar to IncHI2 ter determinants and IncP kla determinants) . Other R478-encoded sequences are related to Tn7, IS26, tus, mucAB, and hok, where the latter is surrounded by insLKJ, and could potentially be involved in post-segregation killing . The similarity to a diverse set of bacterial sequences highlights the ability of horizontally transferable DNA elements to acquire and disseminate genetic traits through the bacterial gene pool. J Med Chem, 2004 Nov 4, 47(23), 5713 - 20 Structure-based exploration of cyclic dipeptide chitinase inhibitors; Houston DR et al.; Family 18 chitinases play an essential role in a range of pathogens and pests . Several inhibitors are known, including the potent inhibitors argadin and allosamidin, and the structures of these in complex with chitinases have been elucidated . Recent structural analysis has revealed that CI-4 {cyclo-(L-Arg-D-Pro)} inhibits family 18 chitinases by mimicking the structure of the proposed reaction intermediate . Here we report the high-resolution structures of four new CI-4 derivatives, cyclo-(L-Arg-L-Pro), cyclo-(Gly-L-Pro), cyclo-(L-His-L-Pro), and cyclo-(L-Tyr-L-Pro), in complex with a family 18 chitinase . In addition, details of enzyme inhibition and in vivo activity against Saccharomyces cerevisiae are presented . The structures reveal that the common cyclo-(Gly-Pro) substructure is sufficient for binding, allowing modification of the side chain of the nonproline residue . This suggests that design of cyclic dipeptides with a view to increasing inhibition of family 18 chitinases should be possible through relatively accessible chemistry . The derivatives presented here in complex with chitinase B from Serratia marcescens provide further insight into the mechanism of inhibition of chitinases by cyclic dipeptides as well as providing a new scaffold for chitinase inhibitor design. Jpn J Infect Dis, 2004 Oct, 57(5), 189 - 92 A nosocomial outbreak of febrile bloodstream infection caused by heparinized-saline contaminated with Serratia marcescens, Tokyo, 2002; Tanaka T et al.; In January 2002, 12 patients with Serratia marcescens bloodstream infection (BSI) were identified in a hospital in Tokyo, Japan . We conducted an epidemiological investigation of this outbreak . We undertook a medical-records review and employee interviews, and performed a case-control study to determine risk factors for S . marcescens BSI . An observational study of the hospital's procedures and an environmental microbiologic sampling were performed . We identified 12 suspected and 12 confirmed patients with S . marcescens BSI, including 7 who died . A case-control study showed that vascular access devices (odds ratio {OR} = 30.46; 95% confidence interval {CI} = 3.5-685.6) and the use of heparin-locks, between December 26 and January 15 (OR = 25.7; 95% CI = 2.3-680.4) were significant risk factors for S . marcescens BSI . The observational study revealed multiple lapses in infection control, including use of multi-dose vials of heparin . The outbreak strain was isolated from a hand-towel in the nurse station . The use of multi-dose vials of heparinized-saline during a particularly busy period was associated with BSI risk . The results underscore the risks inherent in infection-control lapses and the use of multi-dose vials. Microbiol Immunol, 2004, 48(10), 723 - 8 Identification and characterization of the pswP gene required for the parallel production of prodigiosin and serrawettin W1 in Serratia marcescens; Sunaga S et al.; Serratia marcescens mutants defective in production of the red pigment prodigiosin and the biosurfactant serrawettin W1 in parallel were isolated by transposon mutagenesis of strain 274 . Cloning of the DNA fragment required for production of these secondary metabolites with different chemical structures pointed out a novel open reading frame (ORF) named pswP . The putative product PswP (230 aa) has the distinct signature sequence consensus among members of phosphopantetheinyl transferase (PPTase) which phosphopantetheinylates peptidyl carrier protein (PCP) mostly integrated in the nonribosomal peptide synthetases (NRPSs) system . Since serrawettin W1 belongs to the cyclodepsipeptides, which are biosynthesized through the NRPSs system, and one pyrrole ring in prodigiosin has been reported as a derivative of L -proline tethered to phosphopantetheinylated PCP, the mutation in the single gene pswP seems responsible for parallel failure in production of prodigiosin and serrawettin W1. Toxicon, 2004 Nov, 44(6), 641 - 7 Two novel species of tetrodotoxin-producing bacteria isolated from toxic marine puffer fishes; Yu CF et al.; Out of eight dominant discrete bacterial colonies isolated and purified from the toxic marine puffer fishes collected in Hong Kong waters, two novel species of non-sporing, non-acid-fast and chemoorganotrophic bacteria capable of producing tetrodotoxin (TTX, a potent non-protein neurotoxin), as well as one previously reported and confirmed TTX-producing bacterium . They were identified as Microbacterium arabinogalactanolyticum, Serratia marcescens and Vibrio alginolyticus, respectively, all of which are widely distributed in soils, sewage or marine environments . Each bacterial isolate (500 ml broth medium cultured in darkness without aeration for 10 days at 25 degrees C) could produce an amount of toxicity, after extraction and purification, ranging from 78.3 to 105.3 mouse units (MU) in 500 ml of broth medium by mouse bioassay . The principal toxic component in the bacterial cultures was determined to be TTX by thin layer chromatography and mass spectrometry. J Biochem (Tokyo), 2004 Aug, 136(2), 163 - 8 Importance of exposed aromatic residues in chitinase B from Serratia marcescens 2170 for crystalline chitin hydrolysis; Katouno F et al.; Chitinase B (ChiB) of S . marcescens has five exposed aromatic residues linearly aligned toward the catalytic cleft, Tyr481 and Trp479 in the C-terminal domain, and Trp252, Tyr240 and Phe190 in the catalytic domain . To determine the contribution of these residues to the hydrolysis of crystalline beta-chitin, site-directed mutagenesis, to replace them by alanine, was carried out . The Y481A, W479A, W252A, and Y240A mutations all decreased the binding activity and hydrolyzing activity toward beta-chitin microfibrils . Substitution of Trp residues affected the binding activity more severely than that of Tyr residues . The F190A mutation decreased neither the binding activity nor the hydrolyzing activity . None of the mutations decreased the hydrolyzing activity toward soluble substrates . These results suggest that ChiB hydrolyzes crystalline beta-chitin via a mechanism in which four exposed aromatic residues play important roles, similar to the mechanism of hydrolysis by ChiA of this bacterium, although the directions of hydrolysis of the two chitinases are opposite. Infect Control Hosp Epidemiol, 2004 Sep, 25(9), 730 - 4 Rapid eradication of a cluster of Serratia marcescens in a neonatal intensive care unit: use of epidemiologic chromosome profiling by pulsed-field gel electrophoresis; Lai KK et al.; OBJECTIVE: To investigate a cluster of patients infected and colonized with Serratia marcescens in a neonatal intensive care unit (NICU) . METHODS: In June 2001, two neonates in the NICU had clinical infections with S . marcescens and one died . Infection control surveillance data for the NICU revealed that S . marcescens was rarely isolated from clinical specimens . Surveillance and environmental cultures were performed and isolates were typed using pulsed-field gel electrophoresis . Staff and neonates were cohorted and a waterless, alcohol-based handwashing agent was introduced . A case-control study was performed . RESULTS: From June 2 through August 20, 2001, 11 neonates with S . marcescens infection and colonization were identified . The incidence of S . marcescens infections increased from 0.19 per 1,000 patient-days in 2000 to 0.52 per 1,000 patient-days in 2001 (P < .0001) . In the first 3 weeks of the investigation, there were 2 sets of patients and sinks with indistinguishable strains; however, in subsequent weeks, all isolates were of unique strains, signifying no further transmission of the two initial predominant strains . Neonates with S . marcescens were more likely to have a lower gestational age and birth weight . There was no association between cases and healthcare workers (HCWs) . CONCLUSIONS: A cluster of S . marcescens was quickly terminated after the introduction of preventive measures including cohorting of infected and colonized neonates and HCWs, contact precautions, surveillance cultures, and a waterless, alcohol-based hand antiseptic . Chromosomal typing determined that strains with an indistinguishable pattern were no longer present in the unit after control measures were implemented. Infect Control Hosp Epidemiol, 2004 Sep, 25(9), 723 - 9 Clustering of Serratia marcescens infections in a neonatal intensive care unit; Sarvikivi E et al.; OBJECTIVES: To study clusters of infections caused by Serratia marcescens in a neonatal intensive care unit (NICU) and to determine risk factors for S . marcescens infection or colonization . DESIGN: Genotyping of S . marcescens isolates was performed by pulsed-field gel electrophoresis (PFGE) . A retrospective case-control study was conducted . SETTING: A tertiary-care pediatric hospital with a 16-bed NICU . PATIENTS: All neonates with at least one culture positive for S . marcescens in the NICU during December 1999 to July 2002 . Case-patients (n = 11) treated in the NICU during December 1999 to February 2000 were included in the case-control study . Neonates treated in the NICU for at least 72 hours during the same period with cultures negative for S . marcescens were used as control-patients (n = 27) . RESULTS: S . marcescens was cultured from 19 neonates; 9 were infected and 10 were colonized . PFGE analysis identified three epidemic strains; each cluster consisted of identical isolates, except one isolate in the first cluster that was different . The risk factors identified were low birth weight, prematurity, prolonged respiratory therapy, prolonged use of antibiotics, and maternal infection prior to delivery . Overcrowding and understaffing were recorded simultaneously with the clusters . CONCLUSIONS: PFGE analysis showed three independent clusters . Several factors contributed to spread of the epidemic strains: (1) there were many severely premature and susceptible neonates, (2) the NICU was overcrowded during the clusters, and (3) transmission was likely to occur via the hands of staff . Cohorting and improvement of routine infection control measures led to the cessation of each cluster. J Am Vet Med Assoc, 2004 Sep 1, 225(5), 717 - 21 Evaluation of early fetal loss induced by gavage with eastern tent caterpillars in pregnant mares; Bernard WV et al.; OBJECTIVE: To determine whether gavage of pregnant mares (housed without access to pasture) with starved eastern tent caterpillars (ETCs) or their excreta is associated with early fetal loss (EFL), panophthalmitis, or pericarditis . DESIGN: Randomized clinical trial . ANIMALS: 15 mares . PROCEDURE: 15 mares with fetuses from 40 to 80 days of gestation (dGa) were randomly assigned to 1 of 3 groups and received 2.5 g of ETC excreta, 50 g of starved ETCs, or 500 mL of water, respectively, once daily for 10 days . Mares were housed in box stalls, walked twice daily, and not allowed access to pasture for 12 days before or during the 21-day trial . RESULTS: 4 of 5 mares gavaged with starved ETCs (group 2) aborted on trial days 8 (2 mares), 10, and 13 . No control mares or mares that received excreta aborted . Differences between the ETC group and other groups were significant . Abortion occurred on 49, 64, 70, and 96 dGa . Allantoic fluids became hyperechoic the day before or the day of fetal death . Alpha streptococci were recovered from 1 fetus and Serratia marcescens from 3 fetuses . Neither panophthalmitis nor pericarditis was seen . The abortifacient component of the ETCs was not elucidated . CONCLUSIONS AND CLINICAL RELEVANCE: These findings suggest that mares with fetuses from 40 to 120 days of gestation should not be exposed to ETCs because they may induce abortion. Biophys Chem, 2004 Sep 1, 111(1), 1 - 7 Preliminary studies of the 2D crystallization of Omp1 of Serratia marcescens: observation by atomic force microscopy in native membranes environment and reconstituted in proteolipid sheets; Ruiz N et al.; In this work the porin Omp1 of Serratia marcescens was expressed in a porin deficient mutant (Escherichia coli UH302) and its functionality studied following the accumulation of ciprofloxacin in bacteria . The protein was extracted, purified and reconstituted in proteoliposomes of different composition (lipopolysaccharide (LPS), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)) . Maximum extraction of the detergent was achieved applying different steps of dialysis and centrifugation . Proteolipid sheets with different composition were spread onto mica and observed by atomic force microscopy . Two-dimensional crystal of Omp1 was not observed in any case due to low resolution achieved . Judging from the images features POPC is the most suitable phospholipid to enhance 2D lattice formation for Omp1. Insect Biochem Mol Biol, 2004 Sep, 34(9), 893 - 901 Plasmodium berghei ookinetes induce nitric oxide production in Anopheles pseudopunctipennis midguts cultured in vitro; Herrera-Ortiz A et al.; The Anopheles pseudopunctipennis nitric oxide synthase gene (ApNOS) was identified and its partial sequence showed high homology with NOS from A . stephensi, A . gambiae (putative sequence), and Drosophila melanogaster . ApNOS was mainly expressed in male and female adult mosquitoes and was induced by a blood meal . Nitric oxide (NO) was produced by in vitro-cultured mosquito midguts inoculated by enema with Plasmodium berghei ookinetes, Saccharomyces cerevisiae, Gram-positive bacteria (Micrococcus luteus), but not with Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli or Serratia marcescens) . Dihydroxyphenylalanine (L-DOPA) oxidation induced the generation of NO in midguts in vitro, and hydrogen peroxide generated during its oxidation induced ApNOS expression . P . berghei ookinetes exposed in vitro to L-DOPA and sodium nitroprusside (a NO generator) were killed . These observations demonstrate that reactive oxygen and nitrogen intermediates constitute a part of the cytotoxic arsenal employed by Anopheles mosquitoes against microbial pathogens and Plasmodium ookinetes . Appl Microbiol Biotechnol, 2005 Feb, 66(5), 512 - 9 Epub 2004 Sep 03. Chemo-enzymatic synthesis of 2'-O-methoxyethyl ribonucleosides using a phosphodiesterase from Serratia marcescens; Marais G et al.; An enzyme able to cleave the 3',5'-phosphate ring of 2'-methoxyethyl cyclic nucleotides (3',5'-cyclic nucleotide phosphodiesterase, EC 3.1.4.17) from Serratia marcescens DSM 30121 was used to deprotect the cyclic phosphate nucleotides after chemical alkylation . The process yielded 2'-O-alkylated nucleosides used as building blocks of antisense oligonucleotides for subsequent potential applications in therapeutics (antisense oligonucleotide synthesis) and diagnostics . The phosphodiesterase from the Gram-negative enteric bacterium S . marcescens was selected on account of the broad substrate range and high activity of the enzyme . The protein was purified by heat-treatment of the crude cell-free extract, followed by column chromatography (gel filtration) . It was characterised and showed optimal activity at a broad pH range (pH 6.8-9.4, with a peak at ca . pH 8.5) and at a temperature of 60-65 degrees C . No metal ions were required for activity, although Ba(2+) was an activator . Conversion of 2'-O-methoxyethyl cAMP into the corresponding nucleoside derivative on a multi-gram scale was successfully performed in two steps, using the S . marcescens enzyme in conjunction with a commercially available alkaline phosphatase from Escherichia coli. Biochem Pharmacol, 2004 Oct 1, 68(7), 1345 - 52 Mitochondria-mediated apoptosis operating irrespective of multidrug resistance in breast cancer cells by the anticancer agent prodigiosin; Soto-Cerrato V et al.; Prodigiosin (PG) is a red pigment produced by Serratia marcescens with pro-apoptotic activity in haematopoietic and gastrointestinal cancer cell lines, but no marked toxicity in non-malignant cells . Breast cancer is the most frequent malignancy among women in the European Union and better therapies are needed, especially for metastatic tumors . Moreover, multidrug resistance is a common phenomenon that appears during chemotherapy, necessitating more aggressive treatment as prognosis worsens . In this work, we extend our experiments on PG-induced apoptosis to breast cancer cells . PG was potently cytotoxic in both estrogen receptor positive (MCF-7) and negative (MDA-MB-231) breast cancer cell lines . Cytochrome c release, activation of caspases-9, -8 and -7 and cleavage of poly (ADP-ribose) polymerase protein typified the apoptotic event and caspase inhibition revealed that PG acts via the mitochondrial pathway . In a multidrug-resistant subline of MCF-7 cells that over-expresses the breast cancer resistance protein, the cytotoxic activity of PG was slightly reduced . However, flow-cytometry analysis of PG accumulation and efflux in MCF-7 sublines showed that PG is not a substrate for this resistance protein . These results suggest that PG is an interesting and potent new pro-apoptotic agent for the treatment of breast cancer even when multidrug resistance transporter molecules are present. Mol Microbiol, 2004 Aug, 53(4), 1267 - 77 Haemophore-mediated signalling in Serratia marcescens: a new mode of regulation for an extra cytoplasmic function (ECF) sigma factor involved in haem acquisition; Biville F et al.; Bacterial extra cytoplasmic function (ECF) sigma factors control a wide range of cell envelope activities including iron and haem uptake systems . Sigma activity is usually inhibited by membrane-bound antisigma . An extra cytoplasmic signal modulates sigma-antisigma interactions and thereby leads to the transcription of the target operon . Sigma and antisigma genes generally belong to one autoregulated operon . However, ECF sigma and antisigma genes involved in iron acquisition, also called iron starvation ECF, are non-autoregulated exceptions to this rule . We fully reconstituted the has signalling cascade of Serratia marcescens in Escherichia coli . Binding of the haem-loaded haemophore to the outer membrane receptor, HasR, inactivates the antisigma HasS, turning on HasI and thereby allowing has operon transcription . Deletion of the HasR N-terminal extension, present in all characterized outer membrane receptors endowed with signal transduction capacity, abolished the inducing activity but not the transport activity . Induction required the TonB-ExbB-ExbD complex . HasI, like the other iron starvation sigma, is iron repressed but not autoregulated . We found an entirely new regulation for the antisigma hasS gene, the transcription of which is HasI dependent . We suggest that the has system is both activated and repressed by the availability of external haem . When there is enough haem, the HasS antisigma activity is turned off and HasI induces the transcription of hasS . This leads to the storage of inactive HasS molecules which become active when HasR is not occupied by holo-haemophore ligand molecules: as soon as there is a haem shortage transcription is turned off . Positive autoregulation of ECF sigma and antisigma genes is usually considered as a mechanism for amplifying a perceived signal . However, our findings suggest, on the contrary, that antisigma regulation allows fine-tuning to the external signal . The biological significance of ECF sigma and antisigma autoregulation may need to be reconsidered. Ophthalmology, 2004 Aug, 111(8), 1495 - 503; discussion 1503 Bleb-associated endophthalmitis: clinical characteristics and visual outcomes; Busbee BG et al.; PURPOSE: To analyze the clinical characteristics and treatment outcomes of patients with bleb-associated endophthalmitis (BAE) . DESIGN: Retrospective, noncomparative, interventional case series . PARTICIPANTS: Consecutive patients treated at one institution for BAE . INTERVENTIONS: Prompt pars plana vitrectomy (PPV) with intravitreal injection of antibiotics, or prompt vitreous biopsy and intravitreal injection of antibiotics (tap and inject) . METHODS: Retrospective analysis of 68 consecutive cases of BAE between July 1, 1989 and June 30, 2001 . Clinical presentation, treatment modality, microbiologic data, and clinical course were analyzed . Visual outcomes were compared between vitrectomy and tap-and-inject groups, culture-positive and culture-negative groups, and early and late times . MAIN OUTCOME MEASURES: Snellen visual acuities (VAs) at 3 months and 12 months after treatment and at most recent follow-up . RESULTS: The incidence of no light perception (NLP) at 12 months after treatment for BAE was 35% . Vitreous isolates included streptococcal species (32% of positive cultures), Staphylococcus epidermidis (26%), Enterococcus, and Serratia (12% each) . Patients with a positive vitreous culture had significantly worse VA (median, hand movements {HM} at 3 and 12 months after treatment) and a higher rate of NLP vision . Patients treated with tap-and-inject had a significantly worse final VA (medians, HM at 3 months and LP at 12 months) and a significantly higher rate of NLP vision than patients treated with PPV . One third of patients who underwent PPV achieved a final VA of 20/100 or better 12 months after treatment (P = 0.09) . CONCLUSIONS: Bleb-associated endophthalmitis causes significant visual morbidity . Patients with culture-negative BAE and patients treated with prompt PPV may achieve better visual outcome. Curr Eye Res, 2004 May, 28(5), 337 - 42 Quantitative comparison of fluoroquinolone therapies of experimental gram-negative bacterial keratitis; Thibodeaux BA et al.; PURPOSE: To determine the effectiveness of topically applied fluoroquinolones for experimental Pseudomonas or Serratia keratitis . METHODS: Bacteria were injected intrastromally (10(3) colony forming units {CFU}) . From 16 to 22 hours post-infection (PI), a single topical drop of moxifloxacin (Vigamox, 0.545%), levofloxacin (Quixin, 0.5%), ofloxacin (Ocuflox, 0.3%) or ciprofloxacin (Ciloxan, 0.3%) was applied every 30 minutes . At 23 hours PI, corneas were cultured quantitatively . RESULTS: For Pseudomonas keratitis, untreated eyes contained 7 log CFU/cornea and antibiotic-treated eyes demonstrated a > or = 5-log reduction in CFU/cornea (p < or = 0.0001) . Moxifloxacin, levofloxacin, or ciprofloxacin therapies were not significantly different from each other (p > or = 0.67) . For Serratia keratitis, untreated eyes contained 7 logCFU/cornea whereas treated eyes had a > or = 2-log reduction (p < or = 0.0001) . Moxifloxacin therapy proved most effective (p < or = 0.001) . CONCLUSIONS: Overall, moxifloxacin was the most effective of the four fluoroquinolones in reducing CFU/cornea in the rabbit model of gram-negative keratitis. J Appl Microbiol, 2004, 97(3), 656 - 62 Mineral and carbon usage of two synthetic pyrethroid degrading bacterial isolates; Grant RJ et al.; AIMS: To investigate the biodegrading ability and cometabolism of synthetic pyrethroid (SP) utilizing bacteria in cultures with various minerals and carbon sources . METHODS AND RESULTS: Previously isolated SP-degrading Pseudomonas sp . and Serratia sp . were used in cultures containing either flumethrin SP or cypermethrin SP formulations . The culture media consisted of either (i) water only, (ii) water and sucrose, (iii) mineral broth or (iv) mineral broth and sucrose . The growth of both organisms was greatest in the mineral broth and sucrose medium, but the growth-limiting factor for Pseudomonas sp . strain Circle was the mineral content whereas for Serratia sp . strain White it was the carbon substrate . CONCLUSION: The greatest extent of degradation of both SP-based compounds occurred with Pseudomonas sp . strain Circle but was dependant on the medium . SIGNIFICANCE AND IMPACT OF THE STUDY: This investigation could lead to the development of a relatively inexpensive medium supplement to enhance the microbial biodegradation of undesirable compounds, either in situ or ex situ . In this particular case, for the biodegradation of SPs used in sheep dip . Biotechnol Lett, 2004 May, 26(10), 799 - 802 Biosurfactant production by Serratia marcescens SS-1 and its isogenic strain SMdeltaR defective in SpnR, a quorum-sensing LuxR family protein; Wei YH et al.; Serratia marcescens SS-1 and its SpnR-defective isogenic mutant, SMdeltaR, produced an extracellular surfactant able to decrease surface tension of water from 72 to 37 dyne cm(-1) (SMdeltaR strain) and to 45 dyne cm(-1) (SS-1 strain) . The biosurfactant also emulsified kerosene and diesel with a maximum emulsion index of 77% (diesel and kerosene) for the SMdeltaR strain, and 72% (kerosene) and 40% (diesel) for the SS-1 strain . Deletion of spnR gene appeared to enhance biosurfactant production . Model simulations suggest that biosurfactant production by the two strains was growth-associated . The SMdeltaR strain had a yield coefficient of 22-32% g dry cell(-1), which is 32-50% higher than that of the SS-1 strain. Indian J Exp Biol, 2003 Mar, 41(3), 248 - 54 Chitin degrading potential of bacteria from extreme and moderate environment; Nawani NN et al.; Five hundred chitin-degrading bacteria were isolated from 20 different locations . High percentage of potent chitin-degraders was obtained from polluted regions . Potent chitin-degrading bacteria were selected by primary and secondary screening . Among the selected isolates, 78% were represented by the genus Streptomyces . Majority of the isolates had good chitinolysis relative to the growth although isolates with better growth were also seen . Such isolates are important for the production of SCP from chitinous wastes . The potent isolates belonged to the genera Streptomyces, Kitasatosporia, Saccharopolyspora, Nocardioides, Nocardiopsis, Herbidospora, Micromonospora, Microbispora, Actinoplanes, Serratia, Bacillus and Pseudomonas . This study forms a comprehensive base for the study of diversity of chitinolytic systems of bacteria. J Bacteriol, 2004 Aug, 186(15), 4986 - 93 The global regulator genes from biocontrol strain Serratia plymuthica IC1270: cloning, sequencing, and functional studies; Ovadis M et al.; The biocontrol activity of various fluorescent pseudomonads towards plant-pathogenic fungi is dependent upon the GacA/GacS-type two-component system of global regulators and the RpoS transcription sigma factor . In particular, these components are required for the production of antifungal antibiotics and exoenzymes . To investigate the effects of these global regulators on the expression of biocontrol factors by plant-associated bacteria other than Pseudomonas spp., gacA/gacS and rpoS homologues were cloned from biocontrol strain IC1270 of Serratia plymuthica, which produces a set of antifungal compounds, including chitinolytic enzymes and the antibiotic pyrrolnitrin . The nucleotide and deduced protein sequence alignments of the cloned gacA/gacS-like genes-tentatively designated grrA (global response regulation activator) and grrS (global response regulation sensor) and of the cloned rpoS gene revealed 64 to 93% identity with matching genes and proteins of the enteric bacteria Escherichia coli, Pectobacterium carotovora subsp . carotovora, and Serratia marcescens . grrA, grrS, and rpoS gene replacement mutants of strain IC1270 were deficient in the production of pyrrolnitrin, an exoprotease, and N-acylhomoserine lactone quorum-sensing signal molecules . However, neither mutant appeared to differ from the parental strain in the production of siderophores, and only grrA and grrS mutants were deficient in the production of a 58-kDa endochitinase, representing the involvement of other sigma factors in the regulation of strain IC1270's chitinolytic activity . Compared to the parental strain, the grrA, grrS, and rpoS mutants were markedly less capable of suppressing Rhizoctonia solani and Pythium aphanidermatum under greenhouse conditions, indicating the dependence of strain IC1270's biocontrol property on the GrrA/GrrS and RpoS global regulators. J Invertebr Pathol, 2004 Jul, 86(3), 72 - 6 Quantification and kinetics of the decline in grass grub endopeptidase activity during initiation of amber disease; Jackson TA et al.; Amber disease in the grass grub (Costelytra zealandica White) (Coleoptera: Scarabaeidae), caused by strains of the bacteria Serratia entomophila or S . proteamaculans, is characterised by cessation of feeding and clearance of the midgut . Analysis of the midgut enzyme activity in diseased grass grub larvae showed that proteolytic activity was reduced to low levels . The endopeptidases, trypsin, elastase, and chymotrypsin, were all markedly reduced in activity whereas the exopeptidases (leucine-aminopeptidase and carboxypeptidase A and B) were much less affected . There was no effect on the non-proteolytic enzymes, esterase and alpha-amylase . Sequential analysis of enzyme levels in the gut during onset of disease showed that proteolytic activity dropped after cessation of feeding and preceded gut clearance . In starved, uninfected larvae enzyme activity levels remained high, indicating that decline in enzyme activity is not associated with absence of food and cessation of feeding, but with the onset of disease. Folia Microbiol (Praha), 2004, 49(3), 321 - 6 Proteolytic activity in Serratia marcescens clinical isolates; Coria-Jimenez R et al.; Exoproteinase production was demonstrated in 64 clinical isolates of S . marcescens . A significant relationship was found between the site of origin (autopsy material, hemocultures, various other sources), proteinase activity, and LD50 of the analyzed isolates . The number of exoproteinases varied during a 14-h incubation in batch cultures; the most frequently found was a 57.5-kDa proteinase which was observed in all analyzed strains . The exoproteinase production was shown to be related to strain virulence. Cell Tissue Bank, 2002, 3(1), 45 - 47 Devastating endophthalmitis caused by Serratia marcescens in two recipients after transplantation of corneal grafts from the same donor; Levartovsky S et al.; We report two cases of severe endophthalmitis, which were caused by Serratia marcescens, and developed in the immediate postoperative period in two recipients of corneal grafts from the same donor . The cause of the donor's death was massive CVA . He had been on mechanical ventilation for 12 days before he died, and had shown no sign of infectious disease while in the hospital . Vitrectomies were performed in the recipients' eyes on the third day after corneal transplantation . On the same day, and again 1day later, the transplanted eyes were injected intravitreally with vancomycin and ceftazidime . Two months after surgery, both eyes developed phthisis . These cases are similar to other rare reported cases describing the virulence of S . marcescens. J Clin Microbiol, 2004 Jul, 42(7), 3374 - 6 Bacteriology of a bear bite wound to a human: case report; Kunimoto D et al.; Human contact with bears has become more frequent, as has the resultant bear maulings and bite injuries . We report the bacteriology of a patient bitten by a grizzly bear (Ursus arctos) from the Rocky Mountains foothills area east of Banff National Park, Alberta, Canada . The patient received field care, including metronidazole and cefazolin . Subsequent deep-wound cultures grew Serratia fonticola, Serratia marcescens, Aeromonas hydrophila, Bacillus cereus, and Enterococcus durans but no anaerobes. J Nucl Med, 2004 Jul, 45(7), 1209 - 16 (123)I-Labeled chitinase as specific radioligand for in vivo detection of fungal infections in mice; Siaens R et al.; Given the scarcity of diagnostic tools for invasive fungal infections, the aim of this project was to develop new, specific radiopharmaceuticals for diagnosis of fungal infections . Chitin, which is expressed in the fungal cell wall but is absent in mammalian and bacterial cells, represents a potentially selective target for development of tracers for fungal infections . ChiB_E144Q (ChiB = chitinase B) from Serratia marcescens was labeled with (123)I, and in vitro and in vivo studies were assessed . METHODS: (123)I labeling of ChiB_E144Q from S . marcescens by direct iodination was characterized by high-pressure liquid chromatography (HPLC), and stability was evaluated . The in vitro binding properties of the compound to living bacteria, Candida albicans, and Aspergillus fumigatus were examined . Scintigraphy was performed and in vivo characteristics were studied in mice with infected thigh muscles . RESULTS: An average radiochemical yield of 35% was obtained . Radiochemical purity was >97% with a stability of >24 h as determined by HPLC and instant thin-layer chromatography . The average specific activity of the noncarrier-free (123)I-chitinase was 9.25 MBq/ micro g of enzyme . Binding assays showed virtually no binding to Eschericha coli and Staphylococcus aureus, and 2.4 x 10(3) Bq per 1 x 10(7) cells for A . fumigatus and 3.0 x 10(3) Bq per 1 x 10(7) cells for C . albicans (P < 0.05) . Binding of the tracer dropped to almost zero for organisms previously incubated with a 50-fold excess of unlabeled enzyme . At 24 h after injection, target-to-nontarget (T/NT) ratios in mice were 20.6 +/- 3.6 for C . albicans and 15.2 +/- 3.7 for A . fumigatus infections, respectively, whereas T/NT ratios for S . aureus -and E . coli-infected thigh muscles or thigh muscles with a sterile inflammation did not exceed 4.9 +/- 2.6, 3.0 +/- 2.3, and 5.3 +/- 2.8, respectively (P < 0.05) . Target-to-blood ratios for fungus-infected thighs were always >1 . CONCLUSION: Our results show that (123)I-ChiB_E144Q has affinity in vitro for fungi . In vivo, the tracer accumulates in tissue infected with C . albicans and A . fumigatus but not in tissue infected with gram-positive or gram-negative bacteria, or in sterile inflammations, proving it to be a valuable SPECT diagnostic. J Antimicrob Chemother, 2004 Aug, 54(2), 370 - 5 Epub 2004 Jul 01. Identification of genes involved in the susceptibility of Serratia marcescens to polyquaternium-1; Codling CE et al.; OBJECTIVES: Polyquaternium-1 (PQ-1) is a biocide used commercially in a contact lens disinfecting solution, 'Opti-Free Express (Alcon) Multi-Purpose Disinfecting Solution' . The genetic basis for resistance of Serratia marcescens to PQ-1 was investigated using a random transposon-based mutagenesis approach . METHODS: S . marcescens was subjected to random transposon mutagenesis using a mini-Tn5 Km2 transposon . Mutants with increased susceptibility to PQ-1 were selected and the disrupted genes were identified . Antibiotic susceptibility profiles were also determined for all of the mutants . RESULTS: A wide range of genes were found to be disrupted in the mutants . The most common were genes associated with the cell membranes, or involved in biosynthesis and metabolism . CONCLUSIONS: This study shows that random transposon mutagenesis is an effective tool for the elucidation of mechanisms of action and resistance to biocides . The results support our previous findings that PQ-1 is active against the cytoplasmic membrane of S . marcescens. Exp Parasitol, 2004 May-Jun, 107(1-2), 89 - 96 Isolation of Serratia marcescens in the midgut of Rhodnius prolixus: impact on the establishment of the parasite Trypanosoma cruzi in the vector; Azambuja P et al.; The effects of resident bacteria in the stomach of 5th-instar larvae of Rhodnius prolixus on the erythrocyte lysis and Trypanosoma cruzi infection were studied . The bacteria population increased approximately 10,000-fold after feeding . Hemolysis rose to approximately 28% within 24h postfeeding and then linearly grew until day 4 attaining almost 100% . The number of surviving Y strain of T . cruzi in the stomach declined drastically, while the infection with Dm28c clone was maintained stable . Five days after feeding, few different types of bacterial colonies were obtained when stomach content suspensions were spread onto BHI agar plates . The hemolytic bacteria were isolated and identified as Serratia marcescens biotype A1a (referenced as RPH), which produces the pigment prodigiosin . In vitro experiments, comparing incubations of RPH with S . marcescens SM365, a prodigiosin pigment producer, and S . marcescens DB11, a nonpigment variant, as a control, with erythrocytes and T . cruzi demonstrated that: (i) at 30 degrees C, SM365 and RPH diminished the populations of Y strain, but not DM28c clone, and DB11 was unable to lyse both T . cruzi strains; (ii) at 0 degrees C, SM263 and RPH killed the flagellates, but DB11 did not; and (iii) all three strains of S . marcescens were able to lyse erythrocytes . These results suggest that S . marcescens trypanolytic activity from the SM365 and RPH strains is distinct from the hemolytic activity and that prodigiosin is an important factor for the trypanolytic action of the bacteria. J Bacteriol, 2004 Jul, 186(13), 4067 - 74 Free and hemophore-bound heme acquisitions through the outer membrane receptor HasR have different requirements for the TonB-ExbB-ExbD complex; Letoffe S et al.; Many gram-negative bacteria have specific outer membrane receptors for free heme, hemoproteins, and hemophores . Heme is a major iron source and is taken up intact, whereas hemoproteins and hemophores are not transported: the iron-containing molecule has to be stripped off at the cell surface, with only the heme moiety being taken up . The Serratia marcescens hemophore-specific outer membrane receptor HasR can transport either heme itself or heme bound to the hemophore HasA . This second mechanism is much more efficient and requires a higher TonB-ExbB-ExbD (TonB complex) concentration than does free or hemoglobin-bound heme uptake . This requirement for more of the TonB complex is associated with a higher energy requirement . Indeed, the sensitivity of heme-hemophore uptake to the protonophore carbonyl cyanide m-chlorophenyl hydrazone is higher than that of heme uptake from hemoglobin . We show that a higher TonB complex concentration is required for hemophore dissociation from the receptor . This dissociation is concomitant with heme uptake . We propose that increasing the TonB complex concentration drives more energy to the outer membrane receptor and speeds up the release of empty hemophores, which, if they remained on receptors, would inhibit heme transport. Biotechnol Lett, 2004 Apr, 26(8), 681 - 6 Tributyl phosphate degradation by Serratia odorifera; Berne C et al.; Several strains from tributyl phosphate (TBP)-polluted soils were isolated and screened for their ability to degraded this widely used organophosphorus compound . The most active strain, identified as Serratia odorifera, degrades up to 600 microM TBP (initially present in the medium at 2 mM) during its growth phase, within 8 h from inoculation . However, this bacterium could not utilize TBP as the sole carbon and/or phosphorus source but nevertheless is a good candidate for bioremediation of TBP-polluted industrial sites. Int J Antimicrob Agents, 2004 Jun, 23(6), 627 - 30 Influence of the cell wall on ciprofloxacin susceptibility in selected wild-type Gram-negative and Gram-positive bacteria; Berlanga M et al.; The susceptibility of several wild-type bacteria to ciprofloxacin and accumulation of the drug in these bacteria were evaluated . Species studied included Escherichia coli, Serratia marcescens, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis and Bacillus cereus . Ciprofloxacin susceptibility was measured for each strain using two different methods: the minimal inhibitory concentration and the bactericidal index . Significant differences were observed between the results derived from these two methods . Whereas the minimal inhibitory concentration was low in all strains tested, ciprofloxacin's bactericidal activity, as indicated by the bactericidal index, varied with the species studied . To determine whether this finding was due to variations in cell envelope permeability to ciprofloxacin (i.e . to combined cell uptake and efflux), we studied ciprofloxacin accumulation using spectrofluorometry . In Gram-negative bacteria, differences in permeability can lead to altered susceptibility to antibiotics . In fact, the combination of slow uptake and efficient efflux seems to be crucial to the characteristic poor susceptibility of P . aeruginosa to ciprofloxacin . However, the low level of activity of ciprofloxacin against S . aureus and two Bacillus species may have resulted from the drug's interaction with its target enzymes (i.e . topoisomerase IV in S . aureus and DNA gyrase in Bacillus spp.) rather than diminished permeability . BMC Infect Dis . 2004 Jun 09;4(1):16. Serratia marcescens internalization and replication in human bladder epithelial cells; Hertle R et al.; BACKGROUND: Serratia marcescens, a frequent agent of catheterization-associated bacteriuria, strongly adheres to human bladder epithelial cells in culture . The epithelium normally provides a barrier between lumal organisms and the interstitium; the tight adhesion of bacteria to the epithelial cells can lead to internalization and subsequent lysis . However, internalisation was not shown yet for S . marcescens strains . METHODS: Elektronmicroscopy and the common gentamycin protection assay was used to assess intracellular bacteria . Via site directed mutagenesis, an hemolytic negative isogenic Serratia strain was generated to point out the importance of hemolysin production . RESULTS: We identified an important bacterial factor mediating the internalization of S . marcescens, and lysis of epithelial cells, as the secreted cytolysin ShlA . Microtubule filaments and actin filaments were shown to be involved in internalization . However, cytolysis of eukaryotic cells by ShlA was an interfering factor, and therefore hemolytic-negative mutants were used in subsequent experiments . Isogenic hemolysin-negative mutant strains were still adhesive, but were no longer cytotoxic, did not disrupt the cell culture monolayer, and were no longer internalized by HEp-2 and RT112 bladder epithelial cells under the conditions used for the wild-type strain . After wild-type S . marcescens became intracellular, the infected epithelial cells were lysed by extended vacuolation induced by ShlA . In late stages of vacuolation, highly motile S . marcescens cells were observed in the vacuoles . S . marcescens was also able to replicate in cultured HEp-2 cells, and replication was not dependent on hemolysin production . CONCLUSION: The results reported here showed that the pore-forming toxin ShlA triggers microtubule-dependent invasion and is the main factor inducing lysis of the epithelial cells to release the bacteria, and therefore plays a major role in the development of S . marcescens infections. Microbiology, 2004 Jun, 150(Pt 6), 1901 - 10 luxS mutants of Serratia defective in autoinducer-2-dependent 'quorum sensing' show strain-dependent impacts on virulence and production of carbapenem and prodigiosin; Coulthurst SJ et al.; The enzyme LuxS is responsible for the production of autoinducer-2 (AI-2), a molecule that has been implicated in quorum sensing in many bacterial species . This study investigated whether there is a luxS-dependent signalling system in the Gram-negative bacteria Serratia spp . Serratia marcescens is a broad-host-range pathogen and an important cause of nosocomial infections . Production of AI-2 activity was detected in S . marcescens ATCC 274 and Serratia ATCC 39006 and their luxS genes were sequenced . luxS mutants were constructed in these strains and were analysed to determine which phenotypes are regulated by luxS and therefore, potentially, by AI-2 . The phenotypes of the luxS mutants included decreased carbapenem antibiotic production in Serratia ATCC 39006 and decreased prodigiosin and secreted haemolysin production in S . marcescens ATCC 274 . The luxS mutant of S . marcescens ATCC 274 was also found to exhibit modestly reduced virulence in a Caenorhabditis elegans model . Finally, it was shown that the culture supernatant of a wild-type strain contains a signal, presumably AI-2, capable of complementing the prodigiosin defect of the luxS mutant of another strain, even when substantially diluted . It is concluded that luxS modulates virulence and antibiotic production in Serratia, in a strain-dependent manner, and that, for at least one phenotype, this regulation is via extracellular signalling. Appl Environ Microbiol, 2004 Jun, 70(6), 3781 - 4 Short-duration low-direct-current electrical field treatment is a practical tool for considerably reducing counts of gram-negative bacteria entrapped in gel beads; Zvitov R et al.; Application of a direct-current electrical field for very short times can serve as a practical nonthermal procedure to reduce or modify the microbial distribution in gel beads . The viability of Escherichia coli and Serratia marcescens entrapped in alginate and agarose beads decreases as the field intensity and duration of electrical field increase. Diagn Microbiol Infect Dis, 2004 Jun, 49(2), 125 - 9 Survey of CTX-M-3 extended-spectrum beta-lactamase (ESBL) among cefotaxime-resistant Serratia marcescens at a medical center in middle Taiwan; Wu LT et al.; Thirty-four clinical isolates of Serratia marcescens nonsusceptible to cefotaxime were collected from a medical center in middle Taiwan . Confirmatory tests for extended-spectrum beta-lactamases (ESBLs) by cefotaxime and ceftazidime +/- clavulanic acid using Etest ESBL Screen identified only one ESBL producer; the remaining 33 isolates revealed nondeterminable results, because of off-scale minimum inhibitory concentration (MIC) levels for cefotaxime +/- clavulanic acid . Agar microdilution method using broader MIC ranges confirmed 21 ESBL-producers and one non-determinable result, achieving a highly predicting value compared to golden standard by PCR and DNA sequencing analysis, which identified 22 (65%) isolates containing blaCTX-M-3 genes . Only one strain carried concurrent CTX-M-3 and SHV-5 conferring high-level MICs to both cefotaxime (128 microg/mL) and ceftazidime (64 microg/mL) . Other enzymatic mechanisms, such as chromosome-encoded AmpC including a novel SRT-2 enzyme, may confer resistance to cefotaxime on the remaining 12 isolates without ESBL bla genes . Thus, it is unreliable to predict the resistance mechanism by antibiogram, and current Etest ESBL Screen tests . Our study highlights expanding efforts to detect ESBLs in S . marcescens are urgently needed in Taiwan . FEBS Lett, 2004 Jun 4, 567(2-3), 307 - 10 Kinetic evidence related to substrate-assisted catalysis of family 18 chitinases; Honda Y et al.; The hydrolytic reaction of family 18 chitinase has been considered to occur via substrate assisted catalysis . To kinetically investigate the enzyme reaction mechanism, we synthesized compounds designed to reduce the polarization of the carbonyl in N-acetyl group, GlcNAc-GlcN(TFA)-UMB (2) and GlcNAc-GlcN(TAc)-UMB (3) . Kinetic parameters in the hydrolysis of these compounds by chitinase A from Serratia marcescens (ChiA) were compared with those from the hydrolysis of (GlcNAc)2-UMB (1) . The kcat of 2 was 3.4% of 1, but the Km of 2 was 10-fold that of 1 . In contrast, the kcat of 3 was only 0.3% of that of 1, and the two reactions had an identical Km . The drastic decreases in kcat were probably due to the weak nucleophilic activity of the C2-N-trifluoroacetamide and N-thioacetamide groups at reducing ends of compounds 2 and 3, respectively . These results indicate that the anchimeric assistance of the C2 N-acetamide group at GlcNAc plays a key role in the hydrolytic reactions catalyzed by family 18 chitinases. Antimicrob Agents Chemother, 2004 Jun, 48(6), 2321 - 4 Molecular characterization of a carbapenem-hydrolyzing class A beta-lactamase, SFC-1, from Serratia fonticola UTAD54; Henriques I et al.; An environmental isolate of Serratia fonticola resistant to carbapenems contains a gene encoding a class A beta-lactamase with carbapenemase activity . The enzyme was designated SFC-1 . The bla(SFC-I) gene is contained in the chromosome of S . fonticola UTAD54 and is absent from other S . fonticola strains. Singapore Med J, 2004 May, 45(5), 214 - 8 Using pulsed-field gel electrophoresis in the molecular investigation of an outbreak of Serratia marcescens infection in an intensive care unit; Alfizah H et al.; INTRODUCTION: Serratia marcescens is a well-known cause of nosocomial infections and outbreaks, particularly in immunocompromised patients with severe underlying disease . An outbreak due to S . marcescens infection was detected from 13 to 22 February 2001 at the intensive care unit (ICU) of our institution . We used pulsed-field gel electrophoresis (PFGE) typing to analyse the outbreak strains involved . METHODS: A total of 25 isolates were included in this study: 12 isolates from infected patients, nine isolates from insulin solution, one isolate from sedative solution (midazolam and morphine infusion) and one isolate from frusemide solution . Two isolates from other wards which were epidemiologically-unrelated were also included . RESULTS: The S . marcescens from patients, insulin solution and sedative solution showed an identical PFGE fingerprint pattern . The isolate from the frusemide solution had a closely-related PFGE pattern to the outbreak strain with one band difference . Attempts were made in the present study to identify the environmental reservoir of S . marcescens during the outbreak . We found that the insulin and sedative solutions used by the patients were contaminated with S . marcescens which was proven to be the source of the outbreak . CONCLUSION: Using PFGE, we showed that the outbreak in the ICU of our hospital was due to the clonal spread of a single strain of S . marcescens. Protein Expr Purif, 2004 Jun, 35(2), 264 - 71 Isolation, cloning, and overexpression of a chitinase gene fragment from the hyperthermophilic archaeon Thermococcus chitonophagus: semi-denaturing purification of the recombinant peptide and investigation of its relation with other chitinases; Andronopoulou E et al.; A 189-bp sequence was isolated from the hyperthermophilic archaeon Thermococcus chitonophagus and was found to present strong homology with a large number of chitinase genes from a variety of organisms and particularly with the chitinaseA gene from Pyrococcus kodakaraensis (Pk-chiA) . This fragment was subcloned to an expression vector and overexpressed in Escherichia coli . The E . coli BLR21(DE3)pLysS transformant, harbouring the gene on the pET-31b plasmid vector, was found to overproduce the target protein at high levels . The 63 aminoacid-long peptide was efficiently purified to homogeneity, with a one-step, semi-denaturing affinity chromatography, on a metal chelation resin and was used for the production of a specific, polyclonal antibody from rabbits . The produced antibody was demonstrated to display strong and specific affinity for the chitinase A from Serratia marcescens (Sm-chiA), as well as the membrane-bound chitinase70 from Thermococcus chitonophagus (Tc-Chi70) . The strong sequence homology, in combination with the demonstrated specific immunochemical affinity, indicates that the isolated peptide is part of a chitinolytic enzyme of T . chitonophagus . In particular, it could belong to the membrane-bound chi70, or to a distinct chitinase, coded by a different gene, or even by the same gene, following post-transcriptional or post-translational modifications. BMC Microbiol . 2004 Mar 18;4(1):11. A novel medium for the enhanced cell growth and production of prodigiosin from Serratia marcescens isolated from soil; Giri AV et al.; BACKGROUND: Prodigiosin produced by Serratia marcescens is a promising drug owing to its reported characteristics of having antifungal, immunosuppressive and antiproliferative activity . From an industrial point of view the necessity to obtain a suitable medium to simultaneously enhance the growth of Serratia marcescens and the pigment production was the aim of this work . The usage of individual fatty acid as substrate in industries would be cost-effective in the long run and this paved the way for us to try the effect of different fatty acid-containing seeds and oils of peanut, sesame and coconut as source of substrate . RESULTS: The addition of sugars only showed slight enhancement of prodigiosin production in nutrient broth but not in fatty acid containing seed medium . The powdered peanut broth had supported better growth of Serratia marcescens and higher yield of prodigiosin when compared with the existing nutrient broth and peptone glycerol broth . A block in prodigiosin production was seen above 30 degrees C in nutrient broth, but the fatty acid seed medium used by us supported prodigiosin production upto 42 degrees C though the yields were lower than what was obtained at 28 degrees C . From the results, the fatty acid form of carbon source has a role to play in enhanced cell growth and prodigiosin production . CONCLUSION: We conclude by reporting that the powdered and sieved peanut seed of different quality grades were consistent in yielding a fourty fold increase in prodigiosin production over the existing media . A literature survey on the composition of the different media components in nutrient broth, peptone glycerol broth and the fatty acid containing seeds and oils enabled us to propose that the saturated form of fatty acid has a role to play in enhanced cell growth and prodigiosin production . This work has also enabled us to report that the temperature related block of prodigiosin biosynthesis varies with different media and the powdered peanut broth supports prodigiosin production at higher temperatures . The medium suggested in this work is best suitable from an industrial point of view in being economically feasible, in terms of the higher prodigiosin yield and the extraction of prodigiosin described in this paper is simple with minimal wastage. Biophys Chem, 2004 May 1, 109(2), 215 - 27 Molecular and functional characterisation of the Serratia marcescens outer membrane protein Omp1; Ruiz N et al.; Serratia marcescens outer membrane contains three different general diffusion porins: Omp1, Omp2 and Omp3 . Omp1 was cloned and sequenced and it shows a great homology to the family of outer membrane porins that comprises the general porins of enteric bacteria . The gene for Omp1 was transferred into an expression plasmid and was expressed in Escherichia coli UH302 (E . coli UH302 pOM100), a porin deficient strain . Its expression confers a higher susceptibility towards different antibiotics to this strain . Omp1 was purified to homogeneity from outer membrane of E . coli UH302 pOM100 . Reconstitution of the purified protein into black lipid bilayers demonstrated that it is a channel-forming component with a single-channel conductance of approximately 2 nS in 1 M KCl similar to that of other porins from enteric bacteria . Omp1 is slightly cation-selective . Its homology to already crystallised members of the family of enteric porins whose three-dimensional-structures are known and allowed the design of a topology model for Omp1 . The charge distribution within a porin monomer is similar as in other general diffusion pores . The positively charged amino acids localised at the beta-strands opposite the external loop L3, which restrict the pore diameter in the porin monomer . Cornea, 2004 May, 23(4), 360 - 4 Trends in the etiology of infectious corneal ulcers at the F . I . Proctor Foundation; Varaprasathan G et al.; OBJECTIVE: We analyzed laboratory results from corneal ulcers seen from 1976 to 1999 at the Francis I . Proctor Foundation, a referral center in San Francisco, to determine the relative frequencies of pathogens and to analyze for trends in frequencies of the most common pathogens . The results were compared with a previous study of corneal ulcers seen from 1948 to 1976 at the same institution . METHODS: Ulcers presenting to the Proctor Foundation were Gram stained and cultured using standard techniques . Herpetic corneal ulcers were excluded from the study . RESULTS: Organisms were isolated from 427 ulcers, 38% of all cases . Two hundred seventy-eight (59%) isolates were gram-positive bacteria, 145 (31%) gram-negative bacteria, 16 (3%) Acanthamoeba spp., and 36 (8%) fungi . Staphylococcus aureus was the most common organism, composing 20% of all isolates, followed by viridans group streptococci (12%), Streptococcus pneumoniae (11%), Pseudomonas aeruginosa (6%), Moraxella spp . (5%), and Serratia marcescens (4%) . Over the 24-year study period the proportion of positive cultures decreased and the incidence of S . marcescens increased significantly . Comparing the period of 1948-1976 to 1976-1999, the frequency of S . pneumoniae and P . aeruginosa decreased, and that of S . marcescens increased significantly . CONCLUSION: The common pathogens associated with corneal ulcers have changed over the past 50 years in Northern California, with S . pneumoniae and P . aeruginosa being isolated relatively less often and S . marcescens being isolated with increasing frequency . The decrease in isolation of organisms over the 1976-1999 period may have resulted from increasing empiric antibiotic treatment by referring ophthalmologists. Appl Environ Microbiol, 2004 Apr, 70(4), 2021 - 7 Size and UV germicidal irradiation susceptibility of Serratia marcescens when aerosolized from different suspending media; Lai KM et al.; Experimental systems have been built in laboratories worldwide to investigate the influence of various environmental parameters on the efficacy of UV germicidal irradiation (UVGI) for deactivating airborne microorganisms . It is generally recognized that data from different laboratories might vary significantly due to differences in systems and experimental conditions . In this study we looked at the effect of the composition of the suspending medium on the size and UVGI susceptibility of Serratia marcescens in an experimental system built in our laboratory . S . marcescens was suspended in (i) distilled water, (ii) phosphate buffer, (iii) 10% fetal calf serum, (iv) phosphate-buffered saline (saline, 0.8% sodium chloride), and (v) synthetic saliva (phosphate-buffered saline with 10% fetal calf serum) . At low humidity (36%), S . marcescens suspended in water-only medium was the most susceptible to UVGI, followed by those in serum-only medium . The count median diameters (CMDs) for culturable particles from water-only and serum-only media were 0.88 and 0.95 micro m, respectively, with the measurements based on their aerodynamic behavior . The bacteria suspended in phosphate buffer, synthetic saliva, and phosphate-buffered saline had similar UVGI susceptibility and CMD at 1.0, 1.4, and 1.5 micro m, respectively . At high humidity (68%) the CMD of the particles increased by 6 to 16%, and at the same time UVGI susceptibility decreased, with the magnitude of decrease related to the type of suspending medium . In conclusion, the choice of suspending medium influenced both size and UVGI susceptibility of S . marcescens . These data are valuable for making comparisons and deciding on the use of an appropriate medium for various applications. J Mol Biol, 2004 Apr 23, 338(2), 217 - 28 Structural and functional characterization of mitochondrial EndoG, a sugar non-specific nuclease which plays an important role during apoptosis; Schafer P et al.; Combining sequence analysis, structure prediction, and site-directed mutagenesis, we have investigated the mechanism of catalysis and substrate binding by the apoptotic mitochondrial nuclease EndoG, which belongs to the large family of DNA/RNA non-specific betabetaalpha-Me-finger nucleases . Catalysis of phosphodiester bond cleavage involves several highly conserved amino acid residues, namely His143, Asn174, and Glu182 required for water activation and metal ion binding, as well as Arg141 required for proper substrate binding and positioning, respectively . These results indicate that EndoG basically follows a similar mechanism as the Serratia nuclease, the best studied representative of the family of DNA/RNA non-specific nucleases, but that differences are observed for transition state stabilisation . In addition, we have identified two putative DNA/RNA binding residues of bovine EndoG, Arg135 and Arg186, strictly conserved only among mammalian members of the nuclease family, suggesting a similar mode of binding to single and double-stranded nucleic acid substrates by these enzymes . Finally, we demonstrate by ectopic expression of active and inactive variants of bovine EndoG in HeLa and CV1-cells that extramitochondrial active EndoG by itself induces cell death, whereas expression of an enzymatically inactive variant does not. Infect Control Hosp Epidemiol, 2004 Mar, 25(3), 216 - 20 Conjunctival colonization of infants hospitalized in a neonatal intensive care unit: a longitudinal analysis; Raskind CH et al.; OBJECTIVES: To determine the frequency of conjunctival colonization, identify the colonizing flora, and correlate culture results with physical findings in infants in a NICU . DESIGN: Surveillance study . SETTING: Level III NICU of a large university teaching hospital . PATIENTS: All infants admitted for longer than 24 hours during a 26-week period . METHODS: Weekly bacterial conjunctival cultures were performed for all infants . The conjunctival appearance at the time of culture was recorded . The frequency, identity, and correlation of culture results with physical findings were determined . RESULTS: One thousand ninety-one cultures were performed for 319 infants: 133 (42%) had no positive cultures and 186 (58%) had at least one positive culture . Culture analysis revealed that 411 (38%) were positive and yielded 494 isolates comprising more than 18 bacterial species . Bacteria most commonly isolated included coagulase-negative Staphylococcus (CoNS) (75%), viridans group streptococci (8.7%), Staphylococcus aureus (3.8%), Enterococcus species (2.6%), and Serratia marcescens (2.4%) . The frequency of non-CoNS isolates increased significantly during the first 6 weeks of patient hospital stay (6% {1 to 3 weeks} to 12% {4 to 6 weeks}; P = .01), with an increasing trend to 15 weeks (18%) . Correlation of bacteriologic results with physical findings demonstrated that infants with non-CoNS isolates exhibited conjunctival edema, erythema, or exudates more frequently than did infants with CoNS alone (30% vs 13%; P = .0001) . CONCLUSIONS: Conjunctival colonization was common among infants in a NICU . Prolonged hospitalization predisposes to colonization with potentially pathogenic organisms . Physical findings were more likely in patients with non-CoNS conjunctival isolates. Arch Biochem Biophys, 2004 Apr 15, 424(2), 171 - 80 An endochitinase A from Vibrio carchariae: cloning, expression, mass and sequence analyses, and chitin hydrolysis; Suginta W et al.; We provide evidence that chitinase A from Vibrio carchariae acts as an endochitinase . The chitinase A gene isolated from V . carchariae genome encodes 850 amino acids expressing a 95-kDa precursor . Peptide masses of the native enzyme identified from MALDI-TOF or nanoESIMS were identical with the putative amino acid sequence translated from the corresponding nucleotide sequence . The enzyme has a highly conserved catalytic TIM-barrel region as previously described for Serratia marcescens ChiA . The Mr of the native chitinase A was determined to be 62,698, suggesting that the C-terminal proteolytic cleavage site was located between R597 and K598 . The DNA fragment that encodes the processed enzyme was subsequently cloned and expressed in Escherichia coli . The expressed protein exhibited chitinase activity on gel activity assay . Analysis of chitin hydrolysis using HPLC/ESI-MS confirmed the endo characteristics of the enzyme. Arch Med Res, 2004 Jan-Feb, 35(1), 12 - 7 Identification of Serratia marcescens populations of nosocomial origin by RAPD-PCR; Enciso-Moreno JA et al.; BACKGROUND: Serratia marcescens has been increasingly identified as a cause of infection in the immunocompromised host and in high-mortality-rate nosocomial outbreaks . It is thus important to use identification methods that allow study of the dynamics and evolution of nosocomial S . marcescens strains . The aim of this study was to identify S . marcescens strains isolated from nosocomial outbreaks in two pediatric hospitals by random amplification polymorphic DNA polymerase chain reaction (RAPD-PCR) . METHODS: RAPD-PCR was used to study five S . marcescens populations isolated from four different nosocomial outbreaks that occurred in two pediatric hospitals . This method was compared with the widely used biotyping system described by Grimont and Grimont . RESULTS: The combination of biotypification and RAPD-PCR allowed accurate identification of S . marcescens strains isolated in nosocomial outbreaks at pediatric hospitals; by RAPD-PCR, we were able to analyze clonal variations in S . marcescens populations . We established bacterial dissemination patterns in hospital environments according to hospital administration of medical services and compared changes in bacterial DNA amplification patterns in each hospital related with clonal variations by selective pressures . CONCLUSIONS: RAPD-PCR is a useful method to identify S . marcescens strains associated with nosocomial outbreaks. J Intensive Care Med, 2004 Jan-Feb, 19(1), 51 - 5 Drotrecogin alfa (activated) in an infant with gram-negative septic shock; Sajan I et al.; The authors observed the effect of drotrecogin alfa (activated) in a case of pediatric severe sepsis . A 4-month-old male infant with Serratia marcescens septic shock, multiple organ dysfunction syndrome (MODS), and consumptive coagulopathy was admitted . The safety and efficacy of drotrecogin alfa (activated) has not yet been established for patients younger than 18 years of age . This is the first published report of the use of drotrecogin alfa (activated) in an infant with severe sepsis . Within 6 hours of starting therapy, there was a significant improvement in hemodynamics, which was not maintained after the drotrecogin alfa (activated) infusion was temporarily discontinued . No significant bleeding complications occurred during the infusion . A brain MRI on day 22 after drotrecogin alfa (activated) infusion showed bilateral small occipital hemorrhages . Drotrecogin alfa (activated) in this infant was temporally related to significant improvement . It is unknown whether the MRI brain lesions are related to severe sepsis with disseminated intravascular coagulation or drotrecogin alfa (activated) infusion . The authors believe that drotrecogin alfa (activated) should be considered in select children with life-threatening severe sepsis. Ann N Y Acad Sci, 2003 Dec, 1010, 178 - 81 Prodigiosin induces apoptosis by acting on mitochondria in human lung cancer cells; Llagostera E et al.; Prodigiosin (PG) is a secondary metabolite, isolated from a culture of Serratia marcescens, which has shown potent cytotoxicity against various human cancer cell lines as well as immunosuppressive activity . The purpose of this study was to evaluate the role of mitochondria in PG-induced apoptosis . Therefore, we evaluated the apoptotic action of PG in GLC4 small cell lung cancer cell line by Hoechst 33342 staining . In these cells, we examined mitochondrial apoptosis-inducing factor (AIF) and cytochrome c (cyt c) release to the cytosol in PG time-response studies . These findings suggest that PG induces apoptosis in both caspase-dependent and caspase-independent pathways. Science, 2004 Mar 19, 303(5665), 1873 - 6 Genetic basis of natural variation in D . melanogaster antibacterial immunity; Lazzaro BP et al.; Many genes involved in Drosophila melanogaster innate immune processes have been identified, but whether naturally occurring polymorphism in these genes leads to variation in immune competence among wild flies has not been tested . We report here substantial variability among wild-derived D . melanogaster in the ability to suppress infection by a Gram-negative entomopathogen, Serratia marcescens . Variability in immune competence was significantly associated with nucleotide polymorphism in 16 innate immunity genes, corresponding primarily to pathogen recognition and intracellular signaling loci, and substantial epistasis was detected between intracellular signaling and antimicrobial peptide genes . Variation in these genes, therefore, seems to drive variability in immunocompetence among wild Drosophila. J Cataract Refract Surg, 2004 Feb, 30(2), 507 - 12 Ulcerative keratitis caused by Serratia marcescens after laser in situ keratomileusis; Munoz G et al.; We report 2 cases of severe corneal infections caused by Serratia marcescens after laser in situ keratomileusis (LASIK) . Twenty-four hours after LASIK, 2 patients developed infectious keratitis, 1 bilaterally . In each eye, the corneal flap was edematous, ulcerated, and detached from the stromal bed . Treatment included removal of the necrotic flap and aggressive antibiotic therapy . Cultures from corneal exudates were positive for S marcescens . After 1 year, both patients had a loss of best corrected visual acuity (BCVA) ranging from 20/40 to 20/22 because of irregular astigmatism . Overrefraction with a hard contact lens resulted in a BCVA of 20/20 in the 3 affected eyes . Slitlamp examination showed trace subepithelial haze without severe corneal scarring . Videokeratography disclosed areas of paracentral inferior steepening resembling keratoconus . Refraction and videokeratography remained stable after 6 months of follow-up . Ulcerative keratitis caused by S marcescens is a potential complication of LASIK . Bilateral involvement may occur if bilateral simultaneous surgery is performed. J Insect Physiol, 2004 Feb-Mar, 50(2-3), 209 - 16 Estimating disease resistance in insects: phenoloxidase and lysozyme-like activity and disease resistance in the cricket Gryllus texensis; Adamo SA; An animal's ability to resist disease is usually estimated by measuring one or more components of the immune system . There is an assumption that these assays of immunity measure an animal's ability to mount an effective immune response . This paper tests this assumption by examining the relationship between two common estimates of insect immunocompetence, phenoloxidase and lysozyme-like enzyme activity, and resistance to three common insect bacterial pathogens: Serratia marcescens, Serratia liquefaciens, and Bacillus cereus . There was a correlation (Spearman's rs=0.33, p<0.001, n=190 pairs) between total phenoloxidase and baseline lysozyme-like activity within individuals . However, total phenoloxidase and baseline lysozyme-like activity levels did not predict which male crickets would survive any of the three bacterial challenges . Lysozyme-like activity increased after an immune challenge (Friedman, 33.72, p<0.001), and the greater the increase, the greater the chance that the cricket would survive S . marcescens (slope=0.15, chi 2=8.2, p=0.005) or B . cereus (slope=0.8, chi 2=6.4, p=0.01) . The crickets with a greater total hemolymph protein concentration were also more likely to survive a challenge with any of the three bacterial pathogens than the crickets with lower total hemolymph protein concentrations (S . liquefaciens: slope=0.02, chi 2=9.2, p=0.002; B . cereus: slope=0.02, chi 2=6.5, p=0.01; S . marcescens: slope=0.03, chi 2=7.8, p=0.005) . Because of the complexity of the immune system, empirical tests of the relationship between assays of immunity and resistance to a range of actual pathogens are important for correctly interpreting these measures. Nephrology (Carlton), 2003 Feb, 8(1), 16 - 20 Acute vascular access catheters for haemodialysis: complications limiting technique survival; Jefferys A et al.; The use of acute vascular access catheters (AVACs) has facilitated the delivery of haemodialysis to patients lacking functioning access . A review of the experience of a tertiary Australian renal treatment centre, consisting of 205 sequential AVACs in 93 patients, was undertaken over 1 year, to identify issues limiting technique survival . Acute vascular access catheters were inserted as acute dialysis access for patients with chronic renal failure (CRF; 21%), failed grafts or fistulae (18%), acute renal failure (12%), failed chronic ambulatory peritoneal dialysis (CAPD; 8%) or failed prior AVACs (37%) . The majority of AVACs were on the right (74%), and the placement site was simple jugular (69%), tunnelled jugular (15%), femoral (12%), or subclavian (4%) . During follow up, 198 of 205 AVACs were removed . The mean AVAC survival was superior (P < 0.0001, Fisher's protected least significant difference (PLSD) for tunnelled jugular AVACS (62 +/- 46 (SD) days) compared with simple jugular (20 +/- 19), subclavian (18 +/- 13) and femoral (7 +/- 6) . Causes for AVAC removal were: elective (47%), blockage (31%), infection (20%) or cracked catheter (1%) . Routine postremoval tip cultures grew coagulase negative Staphylococcus (CNS, 46%), negative culture (33%), methicillin-resistant Staphylococcus aureus (MRSA; 9%), Staphylococcus aureus (9%), Gram-negative rods (1%), Pseudomonas (0.5%) or other uncommon organisms (2%) . Blood cultures were drawn through the AVAC in the setting of suspected bacteraemia in 42 of 198 AVACs . Blood cultures were negative in 40% . Positive cultures included Staphylococcus species in 55%: including MRSA (19%), Staphylococcus aureus (29%) and CNS (34%) . Rare cultures identified Escherichia coli (2%) or Serratia (2%) . Infection and blockage significantly reduced AVAC survival, affecting more than 50% of cases . Approaches to minimize these complications are likely to lead to improved clinical outcomes with AVAC use. J Soc Biol, 2003, 197(4), 375 - 8 {The nematode Caenorhabditis elegans as a model for the study of host-pathogen interactions}; Ewbank J; For certain pathogens capable of infecting a broad range of organisms, there exist universal virulence factors, necessary for full pathogenicity regardless of the host . This has been most clearly demonstrated by Ausubel and colleagues for the human opportunistic pathogen Pseudomonas aeruginosa . As a consequence, one can use non-mammalian model systems, including the nematode worm Caenorhabditis elegans, to assay for such virulence factors . A significant number of pathogens of C . elegans, that provoke a range of diseases, are now known, including the opportunistic human pathogen Serratia marcescens . After explaining the practical advantages associated with the use of C . elegans, and briefly reviewing previous studies, the results of a screen for S . marcescens virulence factors will be presented. J Econ Entomol, 2004 Feb, 97(1), 74 - 8 Overwintering squash bugs harbor and transmit the causal agent of cucurbit yellow vine disease; Pair SD et al.; Since 1988, cucurbit crops, particularly watermelon, cantaloupe, and squash, grown in Oklahoma and Texas have experienced devastating losses from cucurbit yellow vine disease (CYVD), caused by the phloem-limited bacterium Serratia marcescens Bizio . Squash bug, Anasa tristis (De Geer), is a putative vector of the pathogen . In 2000-2001, overwintering populations of squash bug collected from DeLeon, TX, were tested for their ability to harbor and transmit the bacterium . Individual squash bugs (n = 73) were caged serially for periods of up to 7 d on at least four squash seedlings . Two studies were conducted, one with insects collected in November 2000 placed on first true leaf-stage seedlings and the second with insects from an April 2001 collection, placed on 3-5 true leaf-stage squash . Controls consisted of squash seedlings caged without insects . Squash bug transmission rates of the pathogen in studies I and II were 20 and 7.5%, respectively . Overall, 11.0% of the squash bugs harbored and successfully transmitted the bacterium to squash seedlings . All control plants tested negative for S . marcescens and did not exhibit CYVD . Female squash bugs killed a significantly greater proportion of young first leaf-stage seedlings than males . Feeding on 3-5 leaf-stage squash resulted in no plant mortality regardless of squash bug gender . This study demonstrated that the squash bug harbors S . marcescens in its overwintering state . The squash bug-S . marcescens overwintering relationship reported herein greatly elevates the pest status of squash bug and places more importance on development of integrated strategies for reducing potential overwintering and emerging squash bug populations. Infect Control Hosp Epidemiol, 2004 Feb, 25(2), 156 - 61 Nosocomial Serratia marcescens outbreak in Osaka, Japan, from 1999 to 2000; Takahashi H et al.; OBJECTIVES: To investigate and control an outbreak of bloodstream infections (BSIs) caused by Serratia marcescens and to identify risk factors for respiratory colonization or infection with S . marcescens . DESIGN: Epidemiologic investigation, including review of medical and laboratory records, procedural investigations, pulsed-field gel electrophoresis (PFGE) typing of environmental and patient isolates, statistical study, and recommendation of control measures . PATIENTS AND SETTING: All patients admitted to a 380-bed, secondary-care hospital in Osaka Prefecture, Japan, from July 1999 through June 2000 (study period) . RESULTS: Seventy-one patients were colonized or infected with S . marcescens; 3 patients who developed primary BSIs on the same ward within 5 days in June 2000 had isolates with indistinguishable PFGE patterns and indwelling intravenous catheters for more than 5 days . On multivariate analysis, among 36 case-patients with positive sputum specimens and 95 control-patients, being bedridden (odds ratio {OR}, 15.91; 95% confidence interval {CI95}, 4.17-60.77), receiving mechanical ventilation (OR, 7.86; CI95, 2.27-27.16), being older than 80 years (OR, 3.12; CI95, 1.05-9.27), and receiving oral cleaning care (OR, 3.10; CI95, 1-9.58) were significant risk factors . S . marcescens was isolated from the fluid tanks of three nebulizers and a liquid soap dispenser . The hospital did not have written infection control standards, and many infection control practices were found to be inadequate (eg, respiratory equipment was used without disinfection between patients) . CONCLUSIONS: Poor hospital hygiene and the lack of standard infection control measures contributed to infections hospital-wide . Recommendations to the hospital included adoption of written infection control policies. J Econ Entomol, 2003 Apr, 96(2), 272 - 9 The use of meconia to nondestructively detect sublethal infections in heliothines (Lepidoptera: Noctuidae); Inglis GD et al.; The utility of using meconia to nondestructively detect entomopathogens of lepidopterous heliothines was examined . Early-instar tobacco budworm {Heliothis virescens (F.)} or cotton bollworm {Helicoverpa zea (Boddie)} larvae were inoculated with cytoplasmic polyhedrosis virus (CPV), Serratia marcescens Bizio, or Nosema heliothidis Lutz and Splendor, and the presence of each of the entomopathogens in adults and the meconia discharged during adult eclosion was determined . As the dose of CPV occlusion bodies and N . heliothidis spores but not S . marcescens cells ingested by larvae increased, a greater number of both adults and meconia were infested with the entomopathogens . For all three entomopathogens, no difference was observed between males and females for any of the parameters tested . The accuracy of the meconium method for predicting the presence of the entomopathogens in the adults (i.e., number of individuals in which meconia and adults were both positive, or meconia and adults were both negative) was > or = 92% for CPV, and > or = 79% for S . marcescens and N . heliothidis . Very few false negative predictions (i.e., the meconium was negative but the adult was positive) were observed for CPV (< or = 1%) . The prevalence of false negative predictions ranged from 2 to 9%, and 5 to 21% for S . marcescens and N . heliothidis, respectively . The prevalence of false positive predictions (i.e., the meconium was positive but the adult was negative) was < or = 7% for CPV, < or = 13% for S . marcescens, and 0% for N . heliothidis . The results of this study demonstrate that although not absolute, the meconium method will be an efficacious method to detect nondestructively entomopathogens causing sublethal infections in heliothines, and possibly other insects, and thereby facilitate the rearing of specific pathogen free insects. Biophys J, 2004 Mar, 86(3), 1863 - 70 Moving fluid with bacterial carpets; Darnton N et al.; We activated a solid-fluid interface by attaching flagellated bacteria to a solid surface . We adsorbed swarmer cells of Serratia marcescens to polydimethylsiloxane or polystyrene . The cell bodies formed a densely packed monolayer while their flagella continued to rotate freely . Motion of the fluid close to an extended flat surface, visualized with tracer beads, was dramatically enhanced compared to the motion farther away . The tracer beads revealed complex ever-changing flow patterns, some linear (rivers), others rotational (whirlpools) . Typical features of this flow were