Arch Virol, 1995, 140(6), 1007 - 14 LTR-directed homologous recombination of full-length HIV-1 provirus clone in recA(-) bacteria; Yamada K et al.; During molecular cloning of full-length retroviral plasmid clones occurrence of homologous recombination (HR) between LTR regions is frequently observed . In order to evaluate appropriate host bacterial strains for cloning such HR-prone plasmids, we utilized a linearized template plasmid containing a full-length HIV-1 proviral sequence . The plasmid was linearized within the viral sequence so that plasmid transformed bacteria would grow only when the plasmid was circularized by HR . Using this genetic system for detecting HR, we evaluated the frequency of HR in various recA(-) bacterial strains which are commercially available and in some recA-null strains in which recA-defective phenotype was constructed by P1 transduction . We found that HR occurred even in recA-null strains although in lesser frequencies . The nucleotide sequence analysis at the junction of recombination revealed no loss, insertion or duplication of DNA sequence . It is suggested that recombination machinery other than the RecA system is involved. J Anim Sci, 1995 Jan, 73(1), 257 - 66 Fractionation of nitrogen isotopes by mixed ruminal bacteria; Wattiaux MA et al.; Mixed ruminal bacteria were cultured with glucose, cellulose or no carbohydrate, and ammonium bicarbonate or casein hydrolysate . Changes in amounts of bacterial ammonia and non-ammonia N were measured . Ratios of N isotopes expressed as delta 15N (delta 15N) were measured by isotope ratio mass spectrometry . When bacteria were cultured with glucose and ammonium bicarbonate, bacterial delta 15N decreased from .9 to -5.8/1000 and residual ammonia delta 15N increased from -1.4 to 12.7/1000 . Fractionation of N isotope occurred during ammonia incorporation because the difference between delta 15N of ammonia and delta 15N of bacteria (delta 15N) was 18.8/1000 (P < .01) . However, when casein hydrolysate was the N source, delta 15N between non-ammonia and bacteria averaged only 1.3/1000 (P > .1), indicating no fractionation of N isotopes occurred during utilization of amino acids . The amount of bacterial N was highest at 24 h of incubation when cellulose was the carbohydrate source . At that time, delta 15N between ammonia and bacteria was 8.9/1000 when ammonia was the N source, but delta 15N between non-ammonia and bacteria was 1.7/1000 when casein hydrolysate was the N source . Bacterial N decreased after 24 h when cellulose was the source of carbohydrate . Results indicate that fractionation of N isotopes occurred during ammonia incorporation, but not during incorporation of N from amino acids, deamination, and release of ammonia . Fractionation of N isotopes during incorporation of ammonia N may be used as a marker to study N metabolism by ruminal bacteria. Sci Prog, 1995, 78 ( Pt 1), 19 - 34 Biological activities of lipopolysaccharides from oral bacteria and their relevance to the pathogenesis of chronic periodontitis; Wilson M; Chronic periodontitis is a major cause of tooth loss in adults and is a consequence of the colonisation of the subgingival region by organisms such as Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum . Lipopolysaccharide (LPS) is a constituent of the cell walls of all of these bacteria and is found in large quantities on the surfaces of periodontally-diseased teeth . LPS from oral bacteria has a marked effect on most types of cell found in the periodontal tissues including macrophages, lymphocytes, fibroblasts and osteoblasts . Fibroblasts and macrophages respond to oral LPS by secreting a range of cytokines, and other effector molecules, with inflammatory, immunomodulatory and tissue-destroying capabilities . Lymphocytes are stimulated by LPS to produce a wide range of antibodies with different specificities, hence exacerbating the inflammatory response . By its actions on bone cells, LPS can stimulate bone resorption and inhibit bone formation resulting in erosion of the tooth-supporting alveolar bone . There is, therefore, considerable evidence implicating LPS in the pathogenesis of chronic periodontitis . However, the possible involvement of other biologically-active bacterial components must not be overlooked. Arch Surg, 1994 Dec, 129(12), 1338 - 42 Treatment of burned mice with hyperbaric oxygen reduces mesenteric bacteria but not pulmonary neutrophil deposition; Tenenhaus M et al.; OBJECTIVE: Hyperbaric oxygen (HBO) is used but unproven for many conditions, including burns . We hypothesized that HBO therapy might increase oxygen delivery to intestine during burn shock and decrease mucosal injury . SETTING: University research laboratory . DESIGN AND STUDY PARTICIPANTS: We studied the effects of HBO therapy (100% oxygen at 2.4 atm absolute) on mesenteric bacterial colonies (MBCs) in mice following 32% total body surface area burns . MBCs were counted 24 or 48 hours postburn by culturing mesenteric tissue . Intestinal histologic features were examined, acid-base balance was measured, and pulmonary neutrophil deposition was estimated by lung myeloperoxidase content . INTERVENTIONS: HBO delivered in a compression chamber . MAIN OUTCOME MEASURE: Numbers of mice with MBCs . RESULTS: With twice-daily HBO treatments, each treatment lasting 1.5 or 2 hours, fewer burned mice had MBCs . Three HBO treatments within 24 hours produced seizures, death, and increased numbers of mice with MBCs . Numbers of mice with MBCs were not influenced when compressed air (2.4 atm absolute) or 100% oxygen (1 atm absolute) was used . Villus histologic findings showed less damage in burned mice that received HBO therapy than in controls . Metabolic acidosis was not affected by HBO therapy, nor were lung myeloperoxidase levels . CONCLUSION: HBO therapy was associated with reduced numbers of mice with MBCs after burn injury and reduced histologic evidence of mucosal damage, but lung myeloperoxidase levels and metabolic acidosis were not affected . HBO therapy may increase oxygen delivery to ischemic intestine and improve cellular metabolism; alternatively, increased tissue oxygen may augment killing of translocated bacteria by phagocytic cells . HBO deserves further investigation for burn treatment, but because of the narrow therapeutic window and continued neutrophil sequestration in the lungs, we should proceed cautiously. J Am Coll Surg, 1994 Dec, 179(6), 679 - 88 Effect of secretory IgA on transepithelial passage of bacteria across the intact ileum in vitro; Albanese CT et al.; BACKGROUND: Bacterial translocation is a process believed to result in nosocomial infections . Secretory IgA (sIgA) may have a role in the prevention of translocation by its ability to bind and aggregate bacteria, a function termed "immune exclusion." The present study was done to determine the effect of specific binding of sIgA to bacteria on the movement of these organisms across the intact epithelial membrane . STUDY DESIGN: Bacterial translocation across intact intestinal segments of rats were assessed in vitro using the Ussing model . Secretory IgA (0.25 mg per mL) from pooled human colostrum was added to the perfused segments of ileum in the Ussing system . Subsequently, the membranes were exposed to 5 x 10(9) cfu per mL Escherichia coli on their mucosal side . A second experiment tested the effect of human IgG when perfused with E . coli using the same preparation . All experiments had paired matched rats in a control group without immunoglobulin . The ability of sIgA and IgG to bind to E . coli was studied by an in vitro assay, as well as by transmission electron microscopy and immunofluorescence of random IgA/E . coli experiments . Measurements obtained in all experimental and control groups were the incidence and amount of bacterial passage and the potential difference generated by the intestinal segments (an index of viability) . RESULTS: There were no differences in potential difference between control and experimental groups in either of the two experiments . Secretory IgA bound E . coli and completely prevented passage of E . coli as compared with rats in the control group . IgG bound E . coli; however, the incidence of passage was equal to that of rats in the control group . However, the presence of IgG resulted in a significantly reduced number of bacteria that passed when compared with controls (p < 0.05) . Electron microscopic studies revealed intact surface morphology and immunofluorescence revealed aggregates of IgA and E . coli on the mucosal, but not submucosal, surface of the ileal membranes . CONCLUSIONS: This study provides direct evidence of immune exclusion by sIgA . When bound to bacteria, it prevents passage across a morphologically intact segment of viable intestinal tissue. Appl Environ Microbiol, 1994 Dec, 60(12), 4239 - 44 Cloning of an insecticidal cholesterol oxidase gene and its expression in bacteria and in plant protoplasts; Corbin DR et al.; We cloned and sequenced structural gene choM, which encodes an insecticidally active cholesterol oxidase in Streptomyces sp . strain A19249 . The primary translation product was predicted to be a 547-amino-acid protein whose first 43 amino acids constitute a secretory signal peptide . Expression of the gene with the signal sequence in Escherichia coli resulted in production of a protein that had enzymatic and insecticidal properties which were indistinguishable from those of the cholesterol oxidase secreted by Streptomyces sp . strain A19249 . Expression of the gene with or without the signal sequence in tobacco protoplasts resulted in production of an enzymatically active cholesterol oxidase. Biodegradation, 1994 Dec, 5(3-4), 175 - 84 Molecular genetics of carbon-phosphorus bond cleavage in bacteria; Wanner BL; Phosphonates (Pn) are a large class of organophosphorus molecules that have direct carbon-phosphorus (C-P) bonds in place of the carbon-oxygen-phosphorus ester bond . In bacteria two pathways exist for Pn breakdown for use as a P source: the phosphonatase and C-P lyase pathways . These pathways differ both in regard to their substrate specificity and their cleavage mechanism . The phosphonatase pathway acts on the natural Pn alpha-aminoethylphosphonate (AEPn) . In a two-step process it leads to cleavage of the C-P bond by a hydrolysis reaction requiring an adjacent carbonyl group . In contrast the C-P lyase pathway has a broad substrate specificity . It leads to cleavage of substituted Pn (such as AEPn) as well as unsubstituted Pn by a mechanism involving redox or radical chemistry . Due to its broad substrate specificity, the C-P lyase pathway is generally thought to be responsible for the breakdown of Pn herbicides (such as glyphosate) by bacteria . As a way to gain a more in-depth understanding of these Pn degradative pathways, their respective genes have been isolated and characterized . In the absence of a biochemical assay for the C-P lyase pathway such molecular approaches have been especially valuable . The roles of individual genes have been inferred from DNA sequence analysis and mutational effects . Genes for the C-P lyase pathway exist in a fourteen-gene operon that appears to encode both a binding protein-dependent Pn transporter and a C-P lyase . Genes for the phosphonatase pathway also exist in a gene cluster containing Pn uptake and degradative genes . A combination of biochemistry, molecular biology, and molecular genetics approaches has provided more detailed understanding of the mechanisms of C-P bond cleavage . Such basic information may provide a new handle for improvement of Pn degradation capabilities in bacteria, or in other cells in which the respective genes may be introduced and expressed. Biotechnology (N Y), 1994 Dec, 12(13), 1376 - 8 A carbohydrate biosensor surface for the detection of uropathogenic bacteria; Nilsson KG et al.; We have developed a new surface for use in biosensors that is based on a gold plate covered with a specific carbohydrate receptor structure . The carbohydrate, Gal alpha 1-4Gal, was bound covalently via a thioalkylcarboxy-spacer, or adsorbed as a neoglycoprotein, to a two-dimensional gold surface . Both types of surfaces showed high specificity in the binding of the uropathogenic bacteria P-fimbriated Escherichia coli compared to the binding of non-infectious bacteria . The signal to noise ratio is sufficiently high to allow specific detection of the bacteria in biosensor applications. Br J Theatre Nurs, 1994 Dec, 4(9), 10 - 3 Damp dusting in the operating theatre: implications for bacteria counts; Mackrodt K; This paper describes a research study replicating and expanding on Pickering's paper on damp dusting and its effect on bacteria counts, which concluded that there had been little difference in the counts for both the damp dusting and non-damp dusting period . However there were unexplained fluctuations in levels of bacteria that the author could not explain . A recommendation of the study was to try to ascertain whether damp dusting alters airborne concentrations or whether it is a combination of other variables . This study hoped to explain this. Appl Environ Microbiol, 1994 Dec, 60(12), 4461 - 7 Phylogenetic analysis of a highly specific association between ectosymbiotic, sulfur-oxidizing bacteria and a marine nematode; Polz MF et al.; The phylogenetic relationship of chemoautotrophic, sulfur-oxidizing, ectosymbiotic bacteria growing on a marine nematode, a Laxus sp . (formerly a Catanema sp.), to known endosymbionts and free-living bacteria was determined . Comparative 16S rRNA sequencing was used to investigate the unculturable nematode epibionts, and rRNA-targeted oligonucleotide hybridization probes were used to identify the ectosymbionts in situ . Both analyses revealed a remarkably specific and stable symbiosis . Unique hybridization of a specific probe to the ectosymbionts indicated that only one species of bacteria was present and growing on the cuticle of the nematode . Distance and parsimony methods used to infer phylogenetic trees both placed the nematode ectosymbionts at the base of a branch containing chemoautotrophic, sulfur-oxidizing endosymbionts of three bivalve families and of the tube worm Riftia pachyptila . The most closely related free-living bacteria were chemoautotrophic sulfur oxidizers belonging to the genus Thiomicrospira . Furthermore, our results suggested that a second, only distantly related group of thioautotrophic endosymbionts has as its deepest branch surface-colonizing bacteria belonging to the genus Thiothrix, some of which are capable of sulfur-oxidizing chemoautotrophic growth. Infect Immun, 1994 Dec, 62(12), 5205 - 12 Effects of cytokines and periodontopathic bacteria on the leukocyte function-associated antigen 1/intercellular adhesion molecule 1 pathway in gingival fibroblasts in adult periodontitis; Hayashi J et al.; We investigated the effects of inflammatory cytokines and periodontopathic bacteria on expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1, and E-selectin (endothelial leukocyte adhesion molecule 1) in cultured human gingival fibroblasts (HGF) . Cell surface ICAM-1 was upregulated on HGF under transcriptional control by exposure not only to interleukin-1 beta, tumor necrosis factor alpha, and gamma interferon but also to sonic extracts prepared from Porphyromonas gingivalis and Prevotella intermedia (nigrescens) and lipopolysaccharides from Escherichia coli . However, these stimuli induced only minimal expression of vascular cell adhesion molecule 1 and E-selectin on HGF . Binding assays using HGF and Molt 4, the human T-cell leukemia cell line, showed induced ICAM-1 to be functional, and the increased binding was blocked by a combination of monoclonal antibodies against ICAM-1 and leukocyte function-associated antigen 1 . Furthermore, gingival tissues from adult periodontitis patients showed increased mRNA expression of ICAM-1 compared with that in tissues from normal healthy donors . In immunohistological analysis, we also observed in vivo that the expression of ICAM-1 on fibroblasts in adult periodontitis tissues was greater than that in normal gingiva . Thus, the overexpression of ICAM-1 on gingival fibroblasts induced by cytokines and periodontopathic bacteria is speculated to be deeply involved in the accumulation and retention of leukocyte function-associated antigen 1-bearing leukocytes in adult periodontitis lesions. Biochem Biophys Res Commun, 1994 Nov 30, 205(1), 558 - 64 The nucleotide and deduced amino-acid sequences of a cDNA encoding lactate dehydrogenase from Caenorhabditis elegans: the evolutionary relationships of lactate dehydrogenases from mammals, birds, amphibian, fish, nematode, plants, bacteria, mycoplasma, and plasmodium; Tsoi SC et al.; The nucleotide and deduced amino-acid sequences of a cDNA encoding L-lactate dehydrogenase (LDH) from nematode, Caenorhabditis elegans, were reported . This first invertebrate LDH sequence of 333 amino acids, including the initiation methionine, exhibits 63% identity with that of the most primitive vertebrate lamprey . The evolutionary relationships among 36 LDH isozymes from mammals, birds, amphibian, fish, nematode, plants, bacteria, mycoplasma and plasmodium were analyzed . The invertebrate nematode LDH is evolutionarily positioned between plant LDH and mammalian testicular LDH-C isozymes . The mammalian LDH-C isozyme appears to have arisen after the invertebrate LDH, but prior to the divergence of vertebrate LDH-A (muscle) and LDH-B (heart) isozymes as described previously. Can J Microbiol, 1994 Nov, 40(11), 955 - 64 Characterization of the diversity of sulfate-reducing bacteria in soil and mining waste water environments by nucleic acid hybridization techniques; Telang AJ et al.; Nucleic acid hybridization techniques were used to characterize the sulfate-reducing bacterial communities at seven waste water and two soil sites in Canada . Genomic DNA was obtained from liquid enrichment cultures of samples taken from these nine sites . The liquid enrichment protocol favored growth of the sulfate-reducing bacterial component of the communities at these sites . The genomic DNA preparations were analyzed with (i) a specific gene probe aimed at a single genus (Desulfovibrio), (ii) a general 16S rRNA gene probe aimed at all genera of sulfate-reducing bacteria and other bacteria, and (iii) whole genome probes aimed at specific bacteria . This three-pronged approach provided information on the sulfate-reducing bacterial community structures for the nine sites . These were compared with each other and with the sulfate-reducing bacterial communities of western Canadian oil field production waters, studied previously . It was found that there is considerable diversity in the sulfate-reducing bacterial community at each site . Most sulfate-reducing bacteria isolated from distinct sites are genomically different and differ also from sulfate-reducing bacteria found in oil field production waters. Zentralbl Bakteriol, 1994 Nov, 281(4), 415 - 32 Characterization of the specific antigenicity of representatives of M . senegalense and related bacteria; Besra GS et al.; Representative strains of M . senegalense and an unusual strain, labelled M . farcinogenes (M280) were examined by thin-layer chromatography for the presence of characteristic surface glycolipids . In the case of M . farcinogenes M280 and M . senegalense M264, the glycolipids were of the alkali-labile acyltrehalose lipooligosaccharide (LOS) class of antigens, whereas M . senegalense M263 was found to contain the alkali-stable glycopeptidolipids (GPL) . Through a combination of 1H-NMR, methylation analysis, FAB/MS, and other analytical techniques, the structures of these glycolipids were deduced . The LOS glycolipids were found to be similar in structure to the characteristic glucosyltrehalose-based glycolipids isolated previously from clinical isolates of M . fortuitum, but distinct from the diacyltrehaloses characteristic of the type strain of M fortuitum . The glycopeptidolipids from M . senegalense M263 were closely similar to those characterized previously from M. EMBO J, 1994 Oct 3, 13(19), 4629 - 35 Self-splicing group I intron in cyanobacterial initiator methionine tRNA: evidence for lateral transfer of introns in bacteria; Biniszkiewicz D et al.; A group I self-splicing intron has been found in the anticodon loop of tRNA(fMet) genes in three cyanobacterial genera: Dermocarpa, Scytonema and Synechocystis; it is absent in nine others . The Synechocystis intron is also interrupted by an open reading frame (ORF) of 150 codons . Of these three bacteria, only Scytonema also contains the group I intron that has previously been reported in tRNA(Leu) (UAA) genes in both cyanobacteria and chloroplasts . The presence of an ORF in the tRNA(fMet) intron, the sporadic distribution of the intron among cyanobacteria and the lack of correlation between relatedness of the intron sequences and the bacteria in which they reside, are all consistent with recent introduction of this intron by lateral transfer. FEMS Microbiol Rev, 1994 Oct, 15(2-3), 239 - 49 Genetic adaptation of bacteria to chlorinated aromatic compounds; van der Meer JR; Genetic mechanisms in bacteria provide a continuous source of alterations in DNA sequences that may lead to favourable adaptations . Bacteria that use chlorinated aromatics as sole carbon and energy sources show evidence of these different genetic alterations . The distinct effects of single base-pair mutations on adaptation of bacterial strains (e.g . by changing the substrate specificity of a key metabolic enzyme or regulator protein) have been demonstrated in various studies . In addition to these small sequence modifications, intermolecular or intercellular gene exchange mechanisms can result in new strains with altered metabolic capabilities . The details of these evolutionary processes with respect to the metabolism of chlorobenzenes and chlorocatechols are reviewed in this manuscript. Arch Surg, 1994 Oct, 129(10), 1063 - 6 Translocation of bacteria and endotoxin in organ donors; van Goor H et al.; OBJECTIVE: To determine if bacterial translocation and endotoxin absorption occur in organ donors with an anatomically intact gastrointestinal tract . DESIGN: Case series . SETTING: Intensive care units in general and university hospitals . PATIENTS: Twenty-one (multiple) organ donors . INTERVENTION: None . MAIN OUTCOME MEASURES: Occurrence of factors that may promote bacterial translocation and/or endotoxin absorption . Bacterial concentration in mesenteric lymph nodes, abdominal fluid, blood, liver, lung, and spleen . Endotoxin level in abdominal fluid, peripheral blood, and portal blood . Anatomical integrity of the bowel wall . RESULTS: Factors that may promote bacterial translocation and/or endotoxin absorption were present in all organ donors . Culture specimens revealed bacteria in 14 organ donors (67%) . In 210 (81%) of 260 culture specimens, the bacteria isolated were identical to those isolated from the bowel content, demonstrating bacterial translocation . Endotoxin was found in nine (53%) of 17 abdominal fluid samples, in four (19%) of 21 peripheral blood samples, and in two (10%) of 21 portal blood samples . Light- and electron-microscopic examination of the bowel wall showed no anatomical abnormalities . CONCLUSION: Bacterial translocation and endotoxin absorption are frequent among organ donors and may adversely influence organ function in transplant recipients and other critically ill patients. Curr Biol, 1994 Oct 1, 4(10), 920 - 2 Evolution . Archaea and eukaryotes versus bacteria? Klenk HP, Doolittle WF. The recent discovery of homologs of the eukaryotic transcription factor TATA-binding protein in archaea has been taken as support for the view that archaea and eukaryotes have a close phylogenetic relationship. J Pediatr Surg, 1994 Oct, 29(10), 1348 - 51 Colonization of intestinal bacteria in the normal neonate: comparison between mouth and rectal swabs and small and large bowel specimens; Van Camp JM et al.; Seventy-four New Zealand white rabbit pups were divided into four groups: group I, 2 days of age (n = 9); group II, 3 to 5 days of age (n = 24); group III, 6 to 8 days of age (n = 27); and group IV, 10 to 13 days of age (n = 14) . Mouth swabs (MS), rectal swabs (RS), small bowel specimens (SB), and large bowel specimens (LB) were obtained from each rabbit, incubated for 24 hours in thioglycolate broth, and plated on blood agar in aerobic and anaerobic environments . After 24 hours, growth on blood agar plates were observed . All MS specimens and all but one RS specimen showed positive growth . Growth of both LB and SB specimens increased significantly with age (P < .04) . In addition, SB growth was significantly less than RS or MS growth in groups I, II, and III (P < .05) . LB growth was significantly less than RS or MS growth in group I (P < .01) and tended to be less in groups II and III (62.5% v 100% and 93% v 100%, respectively) . These data show that nearly half of normal rabbits under 6 days of age have sterile small and large intestines despite almost 100% growth from rectal and mouth swabs . These findings partially explain the absence of spontaneous bacterial translocation in young rabbit pups (under 4 days of age) and have important implications for the prophylaxis and treatment of neonatal sepsis. Zhonghua Wai Ke Za Zhi, 1994 Oct, 32(10), 615 - 8 {Relationship between gut origin bacteria and wound infection after thermal injury}; Fu WL et al.; The pUC19 plasmid vector trace with restriction map analysis and fluorescence labelling bacteria method were applied to study the relationship between the gut origin bacteria and wound infection . According to the characteristic of pUC19 plasmid, a special animal model was designed . 110 Wistar rats received 30% TBSA full thickness burns . On hours 6, 12, 24, 48 and day 12 postburn, injured animal were killed . Subeschar tissue homogenates were examined under fluorescence microscope, and bacterial culture, isolation of plasmids and restriction map analysis were also carried out . The results show that during early stage of burns, 32.5% of fluorescence labelling bacteria and 10.81% of pUC19 plasmid vectors could be detected from the subeschar specimens . 12 day postburn, the detectable rage of pUC19 plasmid vector increased to 62.5% . Beside the factor of early colonization, the contaminative route form gut perineum and then wounds should be considered. Proc Natl Acad Sci U S A, 1994 Sep 27, 91(20), 9392 - 6 Evolutionary relationships of lactate dehydrogenases (LDHs) from mammals, birds, an amphibian, fish, barley, and bacteria: LDH cDNA sequences from Xenopus, pig, and rat; Tsuji S et al.; The nucleotide sequences of the cDNAs encoding LDH (EC 1.1.1.27) subunits LDH-A (muscle), LDH-B (liver), and LDH-C (oocyte) from Xenopus laevis, LDH-A (muscle) and LDH-B (heart) from pig, and LDH-B (heart) and LDH-C (testis) from rat were determined . These seven newly deduced amino acid sequences and 22 other published LDH sequences, and three unpublished fish LDH-A sequences kindly provided by G . N . Somero and D . A . Powers, were used to construct the most parsimonious phylogenetic tree of these 32 LDH subunits from mammals, birds, an amphibian, fish, barley, and bacteria . There have been at least six LDH gene duplications among the vertebrates . The Xenopus LDH-A, LDH-B, and LDH-C subunits are most closely related to each other and then are more closely related to vertebrate LDH-B than LDH-A . Three fish LDH-As, as well as a single LDH of lamprey, also seem to be more related to vertebrate LDH-B than to land vertebrate LDH-A . The mammalian LDH-C (testis) subunit appears to have diverged very early, prior to the divergence of vertebrate LDH-A and LDH-B subunits, as reported previously. Proc Natl Acad Sci U S A, 1994 Sep 13, 91(19), 9037 - 41 Evidence for multiple adaptive peaks from populations of bacteria evolving in a structured habitat; Korona R et al.; Natural selection tends to promote the divergence of populations living in different environments . Even in identical environments, however, replicate populations may diverge if they find alternative adaptive solutions . We describe the evolution of 18 bacterial populations (Comamonas sp.) founded from a single progenitor genotype and propagated separately for 1000 generations in two distinct environments, one physically unstructured (mass-action liquid) and the other structured (agar surfaces) . Phenotypic diversity, as reflected in colony morphology, was greater in the structured habitat than in the unstructured habitat . More importantly, the trajectories for mean fitness, as measured by competition against the common ancestor, were more divergent for populations in the structured habitat than those in the unstructured habitat . Structured environments may accelerate evolutionary diversification by promoting genetic polymorphisms within populations, thereby increasing the complexity of genetic constraints that allow divergence among replicate populations. Gut, 1994 Sep, 35(9), 1271 - 4 In vitro acetaldehyde formation by human colonic bacteria; Jokelainen K et al.; Incubation of human colonic contents with various ethanol concentrations (2.75-44 mM) in vitro at 37 degrees C resulted in significant accumulation of acetaldehyde--a toxic and highly reactive compound . At pH 9.6, all samples produced notable acetaldehyde concentrations (58 (13) microM; mean (SEM)) even from the lowest (2.75 mM) ethanol concentration, and the production of acetaldehyde increased lin-early with rising ethanol concentration (r = 0.97; p < 0.005), reaching a peak concentration of 238 (37) microM at 44 mM ethanol . The formation of acetaldehyde took place rapidly, as almost 50% of acetaldehyde formed during the total eight hour incubation was detectable after one hour, and 75% of the total after four hours . Maximal acetaldehyde production from 22 mM ethanol occurred at pH 9.6 (160 (35) microM) but appreciable concentrations were also seen at pH 7.4 (110 (38) microM) and pH 6.0 (63 (19) microM) . At pH 4.0, by contrast, acetaldehyde formation was negligible (17 (5) microM) . 4-Methylpyrazole, a potent inhibitor of alcohol dehydrogenase, showed a decreasing effect on acetaldehyde production in vitro but first at a concentration of 100 mM . Considerable acetaldehyde production by human colonic bacteria--if it occurs also in vivo--could constitute a risk factor for rectal cancer in heavy drinkers and also provide a pathogenetic mechanism for alcohol induced diarrhoea. Microbiology, 1994 Sep, 140 ( Pt 9), 2349 - 54 Evolutionary relationships between sugar kinases and transcriptional repressors in bacteria; Titgemeyer F et al.; We have characterized a new family of proteins (the ROK family) which includes six transcriptional repressors for sugar catabolic operons, three sugar kinases, and three unidentified open reading frames . Analysis of the aligned sequences and phylogenetic tree construction allow predictions regarding the functional nature of conserved domains and residues within these proteins as well as the pathway of evolutionary divergence that gave rise to the family. FEMS Microbiol Lett, 1994 Sep 1, 121(3), 303 - 7 Detection of stress proteins in Porphyromonas gingivalis and other oral bacteria by western immunoblotting analysis; Vayssier C et al.; Detection of stress proteins in Porphyromonas gingivalis was investigated by SDS-PAGE and Western immunoblotting procedure using a polyclonal antibody (anti hsp60) and a monoclonal antibody (anti-Dnak) . Results indicate that P . gingivalis can elicit a hsp60-like stress protein when submitted to different environmental stresses such as a heat shift from 35 degrees C to 43 degrees C, a pH drop from 7.2 to 6.0 or an increase in oxygen concentration . Virulent and non-virulent strains of P . gingivalis responded the same way . The other bacterial species tested also showed an increased synthesis of a GroEL-like protein after heat shock, as detected by the anti hsp60 antibody . However, the monoclonal anti-Dnak recognized an hsp70-like protein only in two of the tested species. Mol Gen Mikrobiol Virusol, 1994 Sep-Oct, (5), 17 - 21 {Cloning and identification of the gene controlling nitrogen metabolism in the photosynthetic purple bacteria Rhodobacter sphaeroides}; Glazer VM et al.; A recombinant plasmid has been selected from the genomic library of Rhodobacter sphaeroides that restores the properties of the wild type strain in the mutant Drn121 . The latter possesses the derepressed synthesis of nitrogenase when grown in the light, inability of nitrogen fixation in the dark and growth on potassium nitrate as a single source of nitrogen, disruption of ammonium ions and methylamine transportation, decreased activity of glutamine synthetase . The gene complementing the drn121 mutation is localized within the EcoRI-HindIII fragment of Rhodobacter sphaeroides chromosome 2.25 kb in size . Analysis of the fragment nucleotide sequence has revealed the fragments with a high level of homology to regulatory genes ntrB (the 3'-end) and ntrC of Rhodobacter capsulatus . The plasmid pRCN102, containing the nifR3-ntrB-ntrC operon of Rhodobacter capsulatus, is able to complement the drn121 mutation while its derivatives having inactivated ntrN or ntrC genes are not . Hence, in Rhodobacter sphaeroides mutant Drn121 the mutation is localized in ntrC gene the product of which is involved not only in nitrogen fixation but also in nitrogen metabolism on the whole. Biol Pharm Bull, 1994 Sep, 17(9), 1277 - 81 Mechanism of an early lysis by fatty acids from axenic Phormidium tenue (musty odor-producing cyanobacterium) and its growth prolongation by bacteria; Yamada N et al.; We have previously demonstrated that bacteria-containing Phormidium tenue, a cyanobacterium which produces musty odor 2-methylisoborneol, grew beyond 8 weeks, whereas axenic alga perished suddenly between the 3rd week and the 4th week while being cultured in the laboratory . This mechanism was investigated . It is assumed that when algal cells grow beyond a certain level, the supply of CO2 becomes inadequate and results in the rapid lysis of axenic alga . At that time, inhibitory substances liberated from algal cells kill the surviving alga . Since the process occurs continuously, this alga is finally annihilated . On the other hand, since inhibitory substances are metabolized or degraded by bacteria coexistent with alga, bacteria-containing P . tenue maintains growth for a long time . The growth-inhibitory substance was found to be unsaturated free fatty acids. Trends Microbiol, 1994 Sep, 2(9), 329 - 32 Role of bacteria-specific T cells in the immunopathogenesis of reactive arthritis; Probst P et al.; Reactive arthritis is a usually self-limited sterile inflammation of joints that follows certain bacterial gastrointestinal or urogenital infections . The immunopathogenesis involves CD4+ T cells, which mediate an antigen-specific TH1 response to bacterial constituents within the joint . Properties of the arthritogenic bacteria and the physicochemical characteristics of the bacterial antigens may contribute to the development of reactive arthritis. Izv Akad Nauk Ser Biol, 1994 Sep-Oct, (5), 810 - 7 {The participation of vaginal bacteria in Phodopus campbelli in the chemical communication between male and female}; Sokolov VE et al.; Phodopus campbelli commonly occurs in dry steppe and semidesert zone of south Siberia, Mongolia and China . Using radiotelemetry we found that a male has to cover about 2 km from his burrow to encounter a receptive female . Female in estrus marks a small area around its burrow by vaginal smear . Experiments were carried out in laboratory to discover the nature of this strong signal . In a "open field" area four boxes within stimuli we recorded the time complemented spent by males near boxes to study the attractive effect of intact receptive female, germ culture of vaginal smear and artificial mixed culture of bacteria which were found in the vaginal smear of Ph . campbelli receptive female . Males (n = 15) spent significantly more time near the boxes with female in estrus or day before estrus as compared with two other days of cycle . Germ culture from vaginal smear sampled on the estrus day was more attractive to males on 6th day than on the 2, -3, -5, -7, -8--or 9th days of cultivation, pure culture or germ culture sampled on anestrus . Mixed culture, which simulated the proportion of predominant bacteria in the estrus vaginal smear, was significantly more attractive for males on the 3rd day of cultivation . Thus sexual attractant of Ph . campbelli could be produced by some bacteria located in the vagina in estrus and it takes a couple of days of cultivation for maximum attractive effect. J Mol Biol, 1994 Aug 12, 241(2), 233 - 45 The major dimerization determinants of the nitrogen regulatory protein NTRC from enteric bacteria lie in its carboxy-terminal domain; Klose KE et al.; The NTRC protein (nitrogen regulatory protein C) of enteric bacteria is an enhancer-binding protein that activates transcription by the sigma54-holoenzyme form of RNA polymerase . NTRC is a homodimeric protein that binds to a dyad-symmetrical site in DNA . To activate transcription NTRC must be phosphorylated and must form an appropriate oligomeric species at an enhancer . In order to study subunit exchange between NTRC dimers, we constructed a fusion of the maltose-binding protein (MBP) to the amino-terminal end of NTRC (MBP-NTRC) and visualized the formation of heterodimers between MBP-NTRC and wild-type NTRC by a gel-mobility shift assay for DNA-binding . When MBP-NTRC is mixed with wild-type NTRC at 37 degrees C, subunit exchange occurs rapidly . The apparent half-life for dissociation of homodimers of NTRC is two to three minutes at 37 degrees C and is not changed by phosphorylation . The isolated carboxy-terminal domain of NTRC (91 amino acid residues) forms heterodimers with both wild-type NTRC and MBP-NTRC, indicating that the C-terminal domain is sufficient for dimerization . The apparent rate of dissociation of homodimers of the C-terminal domain is essentially the same as that of full-length NTRC, indicating that the major dimerization determinants of the protein lie in its C-terminal domain . Congruent with this, a truncated form of NTRC from which the last 58 amino acid residues were removed is a monomer in solution . Moreover, truncated forms of NTRC from which the last 16 or 26 amino acid residues were removed are predominantly monomeric in solution, as is a mutant form with the amino acid substitution A410E in its C-terminal domain . Monomerization of the above mutant forms of NTRC can be rationalized on the basis of homology between the C-terminal region of NTRC and a 50 amino acid residue region of the factor for inversion stimulation (FIS) protein. Appl Environ Microbiol, 1994 Aug, 60(8), 2736 - 45 Influence of substrate diffusion on degradation of dibenzofuran and 3-chlorodibenzofuran by attached and suspended bacteria; Harms H et al.; Dibenzofuran uptake-associated kinetic parameters of suspended and attached Sphingomonas sp . strain HH19k cells were compared . The suspended cells were studied in a batch system, whereas glass beads in percolated columns were used as the solid support for attached cells . The maximum specific activities of cells in the two systems were the same . The apparent half-maximum uptake rate-associated concentrations (Kt') of attached cells, however, were considerably greater than those of suspended cells and depended on cell density and on percolation velocity . A mathematical model was developed to explain the observed differences in terms of substrate transport to the cells . This model was based on the assumptions that the intrinsic half-maximum uptake rate-associated concentration (Kt) was unchanged and that deviations of Kt' from Kt resulted from the stereometry and the hydrodynamics around the cells . Our calculations showed that (i) diffusion to suspended cells and to single attached cells is efficient and therefore only slightly affects Kt'; (ii) diffusion to cells located on crowded surfaces is considerably lower than that to single attached cells and greatly increases Kt', which depends on the cell density; (iii) the convective-diffusive transport to attached cells that occurs in a percolated column is influenced by the liquid flow and results in dependency of Kt' on the flow rate; and (iv) higher specific affinity of cells correlates with higher susceptibility to diffusion limitation . Properties of the experimental system which limited quantitative proof of exclusively transport-controlled variations of Kt' are discussed. Biopolymers, 1994 Aug, 34(8), 1049 - 58 Morphology and primary crystal structure of a silk-like protein polymer synthesized by genetically engineered Escherichia coli bacteria; Anderson JP et al.; The morphology and primary crystal structure of SLPF, a protein polymer produced by genetically engineered Escherichia coli bacteria, were characterized . SLPF is a segmented copolymer consisting of amino acid sequence blocks modeled on the crystalline segments of silk fibroin and the cell attachment domain of human fibronectin . Wide angle x-ray scattering (WAXS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and molecular simulations were used to analyze the primary crystal structure of SLPF . TEM experiments conducted on SLPF droplets cast from formic acid on amorphous carbon film demonstrated that these protein films have a microstructure formed of woven sheaves . The sheaves are composed of well-defined whisker crystallites . The width of the whiskers, 11.8 +/- 2.2 nm, may be correlated to the length of the silk-like segment in SLPF as predicted by molecular simulations . WAXS data, TEM images, SAED, patterns, molecular simulations, and theoretical diffraction patterns all were consistent with the crankshaft model proposed for Silk I by Lotz and Keith. J Immunol Methods, 1994 Aug 1, 173(2), 149 - 56 A two fusion partner system for raising antibodies against small immunogens expressed in bacteria; Hey AW et al.; Production of antisera against proteins that are not amenable to easy purification is most efficiently achieved by expressing the protein as a fusion product in bacteria . However, smaller polypeptides may present difficulties, since the majority of the antibodies may be directed against the fusion partner if the whole fusion protein is used as immunogen, while the target peptide alone may be a poor immunogen due to its small size . We have circumvented this problem through the use of two different fusion partners . The first fusion protein is used for priming the immune response and the first boost, while another fusion partner is substituted for the second boost . Five different polypeptides derived from the human polyomavirus BK, ranging in molecular weight from 4400 (39 amino acid residues) to 11,500 (96 amino acid residues), were used to test this approach . The results obtained indicate that this procedure may be very useful in raising antibodies against small antigens. J Mol Endocrinol, 1994 Aug, 13(1), 11 - 21 Overexpression of the extracellular domain of the thyrotrophin receptor in bacteria; production of thyrotrophin-binding inhibiting immunoglobulins; Costagliola S et al.; The availability of high affinity antibodies to the human TSH receptor (TSHR) would help in defining its functional domains, but this requires the production of pure receptor as immunogen . We have expressed the extracellular domain (ECD) of the TSHR (residues 21-414) as a fusion protein with maltose-binding protein (MBP) in Escherichia coli, using the pMAL-cR1 vector . The major protein in an electrophoretically separated, crude bacterial lysate had a molecular mass of 89 kDa, in agreement with the size predicted for the MBP-ECD fusion product . Its identity was confirmed by Western blotting in which it was recognized by two polyclonal antibodies to synthetic peptides of the TSHR and an anti-MBP . Following purification on an amylose column, 15 mg pure MBP-ECD per litre of culture were produced, which was 5% of the total bacterial protein . Following extensive dialysis in a buffer which produces slight denaturation, MBP-ECD was cleaved with factor Xa . The identity of each protein was confirmed by Western blotting . To investigate the possibility of using the fusion protein as an immunogen we produced rabbit polyclonal antibodies to the ECD which were able to produce immunofluorescent staining of Chinese hamster ovary cells that expressed the TSHR, and revealed a protein of 95 kDa in Western blots of the same cells, in addition to a protein of 55 kDa . Only the protein of 55 kDa was detected in Western blots of human thyroid membranes.(ABSTRACT TRUNCATED AT 250 WORDS) Curr Opin Neurobiol, 1994 Aug, 4(4), 474 - 80 Chemosensing and signal transduction in bacteria; Stock J et al.; Major advances have been made over the past year in understanding the molecular mechanisms involved in membrane receptor function, and in resolving the global organization of intracellular signaling pathways . Crystallographic and biochemical studies are revealing details of transmembrane signaling mechanisms and the phosphorylation reactions of the two-component regulatory systems . In addition, the discovery of new signal transduction pathways and new inputs into known pathways are providing a clearer view of the basic architecture of the signal transduction networks within the bacterial cell. Biochemistry, 1994 Jul 12, 33(27), 8306 - 12 Interaction between cytochrome c2 and reaction centers from purple bacteria; Wang S et al.; The kinetics of electron transfer of cytochrome c2 from Rhodobacter sphaeroides, Rhodobacter capsulatus, and Rhodospirillum centenum to reaction centers from Rb . sphaeroides and Rb . capsulatus have been measured . Observed in the kinetics of decay of the oxidized donor are a rapid first-order rate and one or more slower rates that are due to diffusion-limited complex formation . For reaction centers from Rb . sphaeroides, the fast component had time constants of 1.0 and 0.5 microsecond for cytochrome c2 from Rb . sphaeroides and Rb . capsulatus, respectively, but only a slow component was observed for cytochrome c2 from Rs . centenum . For reaction centers from Rb . capsulatus, the kinetics from all three cytochromes had a fast component with time constants of 1.0, 0.7, and 1.9 microseconds for cytochrome c2 from Rb . sphaeroides, Rb . capsulatus, and Rs . centenum, respectively, although the dissociation constant for cytochrome c2 from Rs . centenum was approximately 20 times larger than that of the other cytochromes . The observation of the fast component for cytochrome c2 from Rs . centenum in reaction centers from Rb . capsulatus but not Rb . sphaeroides demonstrates that the binding interactions for the two reaction centers differ, and the involvement of amino acid residues in the binding is discussed . The kinetics of electron transfer from cytochrome c2 to reaction centers of Rb . sphaeroides from wild type and three mutant strains that have altered carboxyl-terminal regions of the M subunit of the reaction center have also been measured . For cytochrome c2 from Rb . sphaeroides, the kinetics are very similar between the mutants and wild type.(ABSTRACT TRUNCATED AT 250 WORDS) Can J Microbiol, 1994 Jul, 40(7), 561 - 6 Construction of a DNA probe to detect isoquinoline-degrading bacteria; Richards NK et al.; To facilitate the cloning of DNA encoding isoquinoline degradation an assay was developed that allowed the rapid visual scoring of the isoquinoline degradation phenotype of single colonies . Transposon mutagenesis of one of the isolates . Comamonas acidovorans IQ3, was performed using Tn5, and nine Isq-mutants deficient in the ability to utilise isoquinoline as the sole nitrogen source were isolated . These mutants were also incapable of utilising the first metabolite of the isoquinoline degradation pathway, 1-hydroxyisoquinoline, as the sole carbon source . For each Isq-mutant, the EcoRI fragment containing the Tn5 insertion was cloned into pBR322 . Restriction and Southern analyses of the cloned DNA revealed that of the nine Isq-mutants, six contained Tn5 insertions in a common 8.9-kb EcoRI fragment derived from the wild type, C . acidovorans IQ3 . The cloned DNA thought to be involved in the degradation of isoquinoline proved to be specific when used as a probe in colony hybridization to some bacteria possessing the ability to degrade isoquinoline. Biotechniques, 1994 Jul, 17(1), 144 - 6, 148-9 A molecular technique for identification of bacteria using small subunit ribosomal RNA sequences; Avaniss-Aghajani E et al.; We have recently developed a novel molecular technique for identification of specific bacterial species within a complex mixture . The technique uses PCR to amplify small subunit ribosomal RNA (SSU rRNA) genes from a mixture of bacteria . One of the PCR primers is labeled with a fluorescent dye to allow detection of the amplified product . The PCR product is then digested with restriction enzymes and a capillary electrophoresis unit equipped with a laser-induced fluorescence detector is employed to analyze the restriction fragments . Only restriction fragments that contain the fluorescent-labeled primer are detected . Generally, the nucleotide sequence of the SSU rRNA genes is unique for each bacterial species . Consequently, the fluorescent-labeled restriction fragments from different bacterial species often have characteristic lengths . Thus, the different fluorescent peaks that appear in a capillary electropherogram correspond to labeled restriction fragments from different bacterial species . This protocol allows us to identify a number of different bacterial species in a complex mixture . Only a minute sample of bacterial DNA and a minimal amount of time (8-10 h) are required for this analysis . The protocol is sensitive, rapid and capable of identifying a broad spectrum of bacterial species. Adv Dent Res, 1994 Jul, 8(2), 285 - 90 Control of specific plaque bacteria; Russell RR; The Specific Plaque Hypothesis posits that particular bacteria are of unique importance in the etiology of dental caries and periodontal diseases, and a logical conclusion is that these bacteria should be the targets for our 'magic bullets' in devising plaque-control methods . This paper considers the development of preventive measures based on understanding of the significance of particular bacterial species and the properties of those bacteria . Knowledge of the importance of specific organisms as mediators of disease and molecular studies on the properties of potential virulence factors may reveal potential targets for inhibition, blocking by synthetic analogues, or functional inactivation by antibodies. FEBS Lett, 1994 Jun 6, 346(1), 73 - 7 Protein translocation: common themes from bacteria to man; Jungnickel B et al.; Protein transport across the endoplasmic reticulum membrane in eukaryotes and across the cytoplasmic membrane in bacteria have turned out to be highly related . The core component of the translocation apparatus is the Sec61/SecYp complex; at least two of its subunits are conserved in evolution . The Sec61/SecYp complex is involved in both co- and post-translational transport pathways . The two modes require probably distinct additional components. Science, 1994 Jun 3, 264(5164), 1460 - 3 Liquid-crystalline mesophases of plasmid DNA in bacteria; Reich Z et al.; Bacterial plasmids may often reach a copy number larger than 1000 per cell, corresponding to a total amount of DNA that may exceed the amount of DNA within the bacterial chromosome . This observation highlights the problem of cellular accommodation of large amounts of closed-circular nucleic acids, whose interwound conformation offers negligible DNA compaction . As determined by x-ray scattering experiments conducted on intact bacteria, supercoiled plasmids segregate within the cells into dense clusters characterized by a long-range order . In vitro studies performed at physiological DNA concentrations indicated that interwound DNA spontaneously forms liquid crystalline phases whose macroscopic structural properties are determined by the features of the molecular supercoiling . Because these features respond to cellular factors, DNA supercoiling may provide a sensitive regulatory link between cellular parameters and the packaging modes of interwound DNA in vivo. J Infect Dis, 1994 Jun, 169(6), 1265 - 70 Virus and bacteria enhance histamine production in middle ear fluids of children with acute otitis media; Chonmaitree T et al.; Histamine levels were measured in 677 middle ear fluid (MEF) samples from 248 children (aged 2 months to 7 years) with acute otitis media (AOM); of these, 116 (47%) had documented viral infection . Histamine content was higher in bacteria-positive than in bacteria-negative MEF samples (P = .007) and higher in samples from patients with viral infection than in those from patients with no viral infection (P = .002) . Bacteria and viruses together had an additive effect on histamine content in MEF . Histamine concentration in the initial MEF sample tended to be higher in patients with persistent otitis than in those with good response to treatment (P = .14) . Results suggest that viruses, bacteria, or both induce histamine production, which leads to increased inflammation in the middle ear . Antihistaminic drugs may be beneficial . Large, prospective, controlled trials of the effects of antihistamine as an adjunct therapy in bacterial and viral AOM are required before recommendations can be made. Gastroenterology, 1994 Jun, 106(6), 1405 - 17 Natural gastric infection with Helicobacter pylori in monkeys: a model for spiral bacteria infection in humans; Dubois A et al.; BACKGROUND/AIMS: There is no generally accepted model for Helicobacter pylori infection in humans . The aim of this study was to examine the natural history and effect of treatment in rhesus monkeys and sequentially define the immune response to H . pylori in relation to treatment . METHODS: Infection and gastritis were graded blindly by histological analysis and culture of biopsy specimens harvested during gastroduodenoscopies in 26 anesthetized colony-bred monkeys . Plasma H . pylori-specific immunoglobulin (Ig) G levels were determined by enzyme-linked immunosorbent assay . RESULTS: H . pylori and Gastrospirilum hominis-like organisms were present in 13 and 9 monkeys, respectively; 3 animals harbored both organisms, whereas 4 monkeys were not infected . Gastritis score was < or = 1.5 in animals uninfected or infected only with G . hominis-like organisms and > or = 2.0 in all H . pylori-infected animals . IgG ratios were > or = 0.5 in 12 of 13 H . pylori-infected animals and in 2 of 13 H . pylori-negative animals (P < 0.001) . One monkey became infected with H . pylori during the observation period, with concurrent increase of gastritis and plasma IgG levels . In untreated animals, infection, gastritis, and plasma IgG levels remained unchanged over 7-15 months . Triple therapy eradicated H . pylori at 6 months in 4 of 6 animals while suppressing gastritis and plasma IgG levels . CONCLUSIONS: Rhesus monkeys harboring H . pylori are persistently infected and have gastritis and elevated specific IgG levels, all of which may respond to appropriate therapy, whereas G . hominis infection is associated with little inflammation. FEMS Microbiol Lett, 1994 Jun 1, 119(1-2), 199 - 207 Anaerobic degradation of halogenated benzoic acids by photoheterotrophic bacteria; van der Woude BJ et al.; From light-exposed enrichment cultures containing benzoate and a mixture of chlorobenzoates, a pure culture was obtained able to grow with 3-chlorobenzoate (3-CBA) or 3-bromobenzoate (3-BrBA) as the sole growth substrate anaerobically in the light . The thus isolated organism is a photoheterotroph, designated isolate DCP3 . It is preliminarily identified as a Rhodopseudomonas palustris strain . It differs from Rhodopseudomonas palustris WS17, the only other known photoheterotroph capable of using 3-CBA for growth, in its independence of benzoate for growth with 3-CBA and in its wider substrate range: if grown on 3-CBA, it can also use 2-CBA, 4-CBA or 3,5-CBA. Hua Xi Yi Ke Da Xue Xue Bao, 1994 Jun, 25(2), 145 - 8 {Pathological study of enamel caries produced by oral bacteria in vitro}; Zhou X et al.; The authors used the bacterial culture method to study early enamel caries-like lesions in vitro . Pathologic changes in the lesions were observed under polarized light microscope and scanning electron microscope . The results showed that this method could simulate the destructive procedures in carious development . The destructive way and pathologic changes of the caries-like lesions were very similar to those of natural caries . Under microscope, the ultrastructures of the relatively intact layer of the enamel surfaces were already changed . The prisms in the enamel surfaces were destroyed, and dissolved to form small pores . The pores could be an important path of the carious development. Mol Gen Mikrobiol Virusol, 1994 May-Jun, (3), 23 - 5 {Expression of the gene for the gp46 surface glycoprotein from the human T-cell leukemia virus type I (HTLV-I) in bacteria}; Sankov MN et al.; A set of recombinant plasmids containing different fragments of HTLV-I env gene has been constructed on the basis of pUR290-pUR292 vectors . The hybrid proteins containing different fragments of ENV predecessor in the C-terminal of beta-galactosidase differed in stability in Escherichia coli cells . The presence of N-terminal of ENV predecessor in recombinant proteins considerably decreases their resistance to proteases of the bacterial cell . Elimination of this fragment led to obtaining of the recombinant plasmid pESG coding for the high level of synthesis of the env-specific hybrid polypeptide (up to 30% of the total cellular protein) . This 134 Kda protein is able to interact efficiently with the HTLV-I positive sera and may be used in the diagnostic test-systems for identification of the HTLV-I infected patients. J Clin Microbiol, 1994 May, 32(5), 1354 - 6 Mycobacterium smegmatis strain for detection of Mycobacterium tuberculosis by PCR used as internal control for inhibition of amplification and for quantification of bacteria; Kolk AH et al.; For the detection of Mycobacterium tuberculosis by PCR, the IS6110 sequence was used . A modified target was constructed by insertion of 56 nucleotides in the IS6110 insertion element of Mycobacterium bovis BCG . This modified insertion sequence was integrated into the genome of Mycobacterium smegmatis, a mycobacterium species which does not contain the IS6110 element . When DNA from the modified M . smegmatis 1008 strain was amplified with IS6110-specific primers INS1 and INS2, a band of 301 bp was seen on agarose gel, whereas the PCR product of M . tuberculosis complex DNA was a 245-bp fragment with these primers . The addition of a small number of M . smegmatis 1008 cells to clinical samples before DNA purification enables the detection of problems which may be due to the loss of DNA in the isolation procedure or to the presence of inhibitors . The presence of inhibitors of the amplification reaction can be confirmed by the addition of M . smegmatis 1008 DNA after the DNA isolation procedure . Furthermore, competition between the different target DNAs of M . smegmatis 1008 DNA and M . tuberculosis complex DNA enables the estimation of the number of IS6110 elements in the clinical sample. J Invertebr Pathol, 1994 May, 63(3), 275 - 84 Chemotaxis of Mercenaria mercenaria hemocytes to bacteria in vitro; Fawcett LB et al.; Hemocytes of the hard clam Mercenaria mercenaria migrate toward secreted bacterial products in vitro by chemotaxis (i.e., by detection of an increasing chemical gradient of attractant) . The attractants produced by Escherichia coli are peptides or small proteins . Clam hemocytes also migrate toward formyl-methionyl-leucyl-phenylalanine (fMLF), a mammalian neutrophil chemoattractant produced by bacteria, but not toward the related compound formyl-methionyl-valine . Migration of hemocytes to fMLF was blocked with the neutrophil fMLF receptor antagonist, t-Boc-MLF, suggesting that the hemocytes possess this receptor and that the response is receptor-mediated . However, fMLF is not the major bacterial chemoattractant for clam hemocytes, as t-Boc-MLF did not block migration of these cells to secreted bacterial chemoattractants. J AOAC Int, 1994 May-Jun, 77(3), 623 - 7 Enumeration of total bacteria in raw and pasteurized milk by reflectance colorimetry: collaborative study; Richardson GH et al.; Seven out of 9 laboratories completed a collaborative study comparing a reflectance colorimetric (RC) bioactivity monitor (Omnispec 4000) method to the standard plate count (SPC) method for estimation of total bacteria in raw and homogenized pasteurized milk . Each laboratory analyzed 12 different samples by the SPC method and 24 samples (12 blind duplicates) by the RC method . For the RC method RSDr was 1.7%, and RSDR was 4.5% . RSDR for the SPC method was 20.8% . The method was adopted first action by AOAC INTERNATIONAL. Proc Natl Acad Sci U S A, 1994 Apr 12, 91(8), 3117 - 21 Synthesis of circular RNA in bacteria and yeast using RNA cyclase ribozymes derived from a group I intron of phage T4; Ford E et al.; Studies on the function of circular RNA and RNA topology in vivo have been limited by the difficulty in expressing circular RNA of desired sequence . To overcome this, the group I intron from the phage T4 td gene was split in a peripheral loop (L6a) and rearranged so that the 3' half intron and 3' splice site are upstream and a 5' splice site and 5' half intron are downstream of a single exon . The group I splicing reactions excise the internal exon RNA as a circle (RNA cyclase ribozyme activity) . We show that foreign sequences can be placed in the exon and made circular in vitro . Expression of such constructs (RNA cyclase ribozymes) in Escherichia coli and yeast results in the accumulation of circular RNA in these organisms . In yeast, RNA cyclase ribozymes can be expressed from a regulated promoter like an mRNA, containing 5' leader and 3' trailer regions, and a nuclear pre-mRNA intron . RNA cyclase ribozymes have broad application to questions of RNA structure and function including end requirements for RNA transport or function, RNA topology, efficacy of antisense or ribozyme gene control elements, and the biosynthesis of extremely long polypeptides. Clin Exp Immunol, 1994 Apr, 96(1), 91 - 7 Oral and aerosol immunization with viable or inactivated Actinobacillus pleuropneumoniae bacteria: antibody response to capsular polysaccharides in bronchoalveolar lavage fluids (BALF) and sera of pigs; Hensel A et al.; To investigate the antibody response after local application of lung-pathogenic bacteria, pigs were immunized with viable or inactivated Actinobacillus pleuropneumoniae by the oral and aerogenous route . After 3 weeks class-specific immunoglobulins against purified A . pleuropneumoniae capsular polysaccharides (CP) were determined in serum and BALF by ELISA . A significant increase of IgA antibodies was found in BALF but not in sera of all immunized pigs . Oral immunization with viable A . pleuropneumoniae and aerosol immunization with either viable or inactivated bacteria resulted in a significant increase of IgG antibodies to the CP antigen in BALF, whereas only aerosol exposure to viable bacteria resulted in a significant increase in IgG antibodies in serum . A significant increase in anti-CP IgM in BALF was observed after aerosol exposure but not after oral immunization . IgM antibodies towards CP increased significantly by both routes of immunization with viable bacteria . The anti-CP activity of all three isotypes in sera and BALF was low in all groups compared with the positive controls, although inoculation of viable A . pleuropneumoniae led to higher levels of antibody concentration than inactivated bacteria . Our results indicate a traffic of primed lymphocytes from the gut into the bronchoalveolar airways and further support the hypothesis that polysaccharide-specific B cells may functionally mature at the mucosal surfaces. Mol Microbiol, 1994 Apr, 12(1), 153 - 63 A seven-gene operon essential for formate-dependent nitrite reduction to ammonia by enteric bacteria; Hussain H et al.; The DNA sequence of the regulatory region and the structural gene, nrfA, for cytochrome c552 of Escherichia coli K-12 have been reported . We have now established that nrfA is the first gene in a seven-gene operon, designated the nrf operon, at least five of which are essential for formate-dependent nitrite reduction to ammonia . This operon terminates just upstream of the previously sequenced gltP gene encoding a sodium-independent, glutamate and aspartate transporter . Expression of lac fused to nrfA, nrfE or nrfG is regulated by oxygen repression, FNR-dependent anaerobic induction, nitrite induction and nitrate repression during anaerobic growth, exactly as previously reported for the nrfA promoter . In contrast, expression of the gltP-lac fusion was FNR-independent . The open reading frame immediately downstream of nrfA encodes NrfB, a hydrophilic, penta-haem cytochrome c with an M(r) of 20,714 . The structure of the N-terminal region is typical of a signal peptide for a periplasmic protein: cleavage at the putative signal peptide cleavage site, Ala-26, would result in a periplasmic cytochrome with a molecular mass of 18 kDa . The NrfC polypeptide, M(r) 24,567, contains 16 cysteine residues arranged in four clusters typical of the CooF super-family of non-haem iron-sulphur proteins . The NrfD sequence predicts a 318-residue hydrophobic protein with a distribution of acidic and basic amino acids which suggests that NrfD is an integral transmembrane protein with loops in both the periplasm and the cytoplasm . Proteins most similar to NrfD include the PsrC subunit of polysulphide reductase from Wolinella, but, as seven of the 10 most similar proteins are NADH-ubiquinone oxidoreductases, we propose that NrfD participates in the transfer of electrons from the quinone pool into the terminal components of the Nrf pathway . NrfE, M(r) 60,851, is predicted to be another hydrophobic, integral membrane protein homologous to the CdI1 protein of Rhodobacter capsulatus, which has been implicated in the assembly of periplasmic c-type cytochromes . The sequence of the 127 residue NrfF polypeptide, M(r) 14,522, is strikingly similar to the CcI2 protein of R . capsulatus, especially in the putative haem-binding motif, RCPQCQNQN.(ABSTRACT TRUNCATED AT 400 WORDS) Mol Microbiol, 1994 Apr, 12(1), 1 - 9 Cytochrome c biogenesis in bacteria: a possible pathway begins to emerge; Thony-Meyer L et al.; Cytochrome c biogenesis describes the posttranslational pathway for the conversion of pre-apocytochrome c into the mature holocytochrome c . It involves an unknown number of consecutive biochemical steps, including translocation of the precursor polypeptide and haem into the periplasm and the covalent linkage between these two molecules . Genetic and molecular analysis of several bacterial mutants suggest that at least eight genes contribute to this process . In this review we summarize the present knowledge of the cytochrome c maturation pathway in bacteria and propose a model in which certain genes and their products are attributed to specific functions. Microsc Res Tech, 1994 Apr 1, 27(5), 389 - 401 Electron microscopic studies of magnetosomes in magnetotactic bacteria; Bazylinski DA et al.; Electron microscopic studies on magnetosomes in magnetotactic bacteria have revealed much information on their composition, structure, and even the formation of their mineral phase . The mineral phases of the magnetosomes are of two general types: iron oxides and iron sulfides . Iron oxide-type magnetosomes contain particles of the ferrimagnetic mineral magnetite (Fe3O4) while the iron sulfide-type contain ferrimagnetic greigite (Fe3S4), greigite and non-magnetic pyrite (FeS2), or possibly ferrimagnetic pyrrhotite (Fe7S8) . Regardless of their composition, the crystalline particles in magnetosomes have a narrow size range: approximately 35 to 120 nm . Magnetite crystals in this size range are single-magnetic-domains and confer a permanent magnetic dipole moment to the cell . The single-domain size range for greigite is not known but is probably similar to that for magnetite . The morphology of the particles in the bacterial magnetosomes appears to be species-specific . Morphologies of magnetite crystals in different species of magnetotactic bacteria include cubo-octahedra, parallelepipedal (truncated hexahedral or octahedral prisms), and tooth- or bullet-shaped (anisotropic) . Morphologies of greigite particles include cubo-octahedra and rectangular prismatic . The greigite-pyrite particles are generally pleomorphic with no consistent crystalline morphology . A membrane has been shown to surround the particles in some organisms and may be involved in the formation of the crystalline phase while also providing physical constraints on the size and the shape of the crystal . These results clearly indicate that the biomineralization process involved in the bacterial magnetosome, a good example of a self-assembled structure on a nanometer scale, is highly controlled by the organism. Appl Environ Microbiol, 1994 Apr, 60(4), 1179 - 83 Blood agar to detect virulence factors in tap water heterotrophic bacteria; Payment P et al.; Cytolytic colonies were found in 57% of tap water samples, and up to 6% of samples were found to contain bacteria having three or more virulence factors . The factors evaluated were cytotoxicity, hemolysis, cell adherence, and cell invasiveness . Overall, 17% of the samples contained cytolytic colonies that were adherent and hemolytic . Among the media tested, tryptic soy agar with sheep blood (incubated at 35 degrees C for 48 h) was the best medium for the detection of cytolytic colonies . Of the colonies growing on this medium, 13% were cytolytic, whereas on medium R2A, less than 3% were cytolytic . Furthermore, when tryptic soy agar with blood was used, 24% of the samples contained colonies with at least three virulence factors whereas only 5% were positive with R2A . Routine monitoring by using tryptic soy agar with sheep blood is suggested as an appropriate procedure for the detection of bacteria with pathogenic potential in drinking water. Rev Argent Microbiol, 1994 Apr-Jun, 26(2), 59 - 64 Relationship of physical factors and salinity with indicator bacteria in Bahía Blanca estuary waters, Argentina; Cabezali CB et al.; The relationship between the number of Escherichia coli, terrestrial and marine heterotrophic bacteria, with certain physical and chemical parameters in Bahia Blanca estuary waters, were investigated by means of a statistical analysis of multiple linear regression . The samples were taken during a period of 16 months . Although distance from the sewage outlet seems to be the factor having the greatest effect on the number of alien bacteria, the models obtained for E . coli are inappropriate to predict bacterial behaviour in this particular natural habitat, while for heterotrophic bacteria descriptive models were selected . The results of this study suggest that many factors affect bacterial population densities in this estuarine ecosystem . This should be taken into account trying to solve the problem in order to avoid progressive degradation. Comput Methods Programs Biomed, 1994 Apr, 42(4), 255 - 62 A simple data compression scheme for binary images of bacteria compared with commonly used image data compression schemes; Wilkinson MH; A run length code compression scheme of extreme simplicity, used for image storage in an automated bacterial morphometry system, is compared with more common compression schemes, such as are used in the tag image file format . These schemes are Lempel-Ziv and Welch (LZW), Macintosh Packbits, and CCITT Group 3 Facsimile 1-dimensional modified Huffman run length code . In a set of 25 images consisting of full microscopic fields of view of bacterial slides, the method gave a 10.3-fold compression: 1.074 times better than LZW . In a second set of images of single areas of interest within each field of view, compression ratios of over 600 were obtained, 12.8 times that of LZW . The drawback of the system is its bad worst case performance . The method could be used in any application requiring storage of binary images of relatively small objects with fairly large spaces in between. Lett Appl Microbiol, 1994 Apr, 18(4), 214 - 7 Vegetable sponge as a matrix to immobilize micro-organisms: a trial study for hyphal fungi, yeast and bacteria; Iqbal M et al.; The vegetable sponge of Luffa cylindrica was studied as a matrix for the immobilization of hyphal fungi, yeast and bacteria . All were observed to be entrapped within the sponge . When the various immobilized systems were subcultured in their respective fresh nutrient media, the hyphal fungi showed an increase in biomass with no cellular release and secondary colony formation . The immobilized yeast and bacteria released cells into the medium . Advantages of the reticulated biostructure as an immobilization matrix are discussed. Rev Biol Trop, 1994 Apr-Aug, 42(1-2), 9 - 13 {Isolation of the bacteria Ureaplasma sp . in the reproductive tract of milking cows in Costa Rica}; Leon BA et al.; This is the first report of Ureaplasma sp . from the reproductive tract of Costa Rican cows . Among 204 animals sampled from 11 dairy farms in the country's Central Plateau, the infection rate was 0-71% . Isolation was more frequent in vulvo-vestibular (38.7%) than in cervical swabs (23%) . Ureaplasma was correlated with clinical granular vulvitis symptoms. Artif Organs, 1994 Mar, 18(3), 188 - 92 Bacteria- and endotoxin-free dialysis fluid for use in chronic hemodialysis; Bambauer R et al.; As the quality of water in the dialysis fluid varies considerably, dialysis fluid is contaminated with a high percentage of bacteria and endotoxins . The bacterial populations contained in the dialysis fluid are as heterogeneous as the chemical structure of the endotoxins that result . The latter can pass through the dialysis membrane whereby high-flux membranes permit a larger number of retransportable molecules than low-flux membranes . A central aim toward a future, safe dialysis process should, therefore, be the production of a dialysate that is free of bacteria and endotoxins . As we were able to demonstrate in various examinations, this goal is most likely to be achieved with the aid of sterile filtration using hollow fiber modules of polyamid . To avoid disinfection of the polyamid membrane, as this would only reach bacteria but not endotoxins, the filter was changed after at most 10 h . The achieved dialysis fluid was free of bacteria and endotoxins . We were also able to show that the release of interleukin-1 was reduced . In addition, side-effects, such as a drop in blood pressure, headaches, muscular cramps, and nausea, were reduced. Mol Microbiol, 1994 Mar, 11(6), 1151 - 7 Lon-dependent proteolysis of CcdA is the key control for activation of CcdB in plasmid-free segregant bacteria; Van Melderen L et al.; The ccd locus contributes to the stability of plasmid F by post-segregational killing of plasmid-free bacteria . The ccdB gene product is a potent cell-killing protein and its activity is negatively regulated by the CcdA protein . In this paper, we show that the CcdA protein is unstable and that the degradation of CcdA is dependent on the Lon protease . Differences in the stability of the killer CcdB protein and its antidote CcdA are the key to post-segregational killing . Because the half-life of active CcdA protein is shorter than that of active CcdB protein, persistence of the CcdB protein leads to the death of plasmid-free bacterial segregants. J Cell Sci, 1994 Mar, 107 ( Pt 3), 673 - 82 The distribution of cytoplasmic bacteria in the early Drosophila embryo is mediated by astral microtubules; Callaini G et al.; Maternally inherited cytoplasmic bacteria have occasionally been observed in embryos and adults of different strains of several Drosophila species . While there is a considerable body of data on the relationship between bacteria and embryo viability, little is known about the behavior of these bacteria during the early development of Drosophila . In eggs laid by infected Drosophila melanogaster females we showed that cytoplasmic bacteria were initially concentrated in a thin cortical layer and scattered in the yolk region . During the following syncytial blastoderm mitoses the bacteria mainly accumulated towards the poles of the mitotic spindles, suggesting that astral microtubules play a role in localizing bacteria . This is supported by the observation that treatment of the infected embryos with the microtubule-disrupting drug colchicine led to the partial dissociation of the bacteria from the spindle poles, whereas cytochalasin treatment left almost all the bacterial clusters intact . Moreover, bacteria were not found near the polar bodies and yolk nuclei, which were without astral microtubules . In mitosis-defective embryos, with centrosomes dissociated from the nuclei, the bacteria were concentrated in association with the isolated astral microtubules, and in cold-treated embryos, in which microtubules regrew from isolated centrosomes after recovering, the bacteria clustered around the newly formed asters . These observations, also supported by electron microscope analysis, indicate a close relationship between cytoplasmic bacteria and astral microtubules, and suggest that the latter were able to build discrete cytoplasmic domains ensuring the proper distribution of cytoplasmic components during the blastoderm mitoses, despite the lack of cell membranes. J Androl, 1994 Mar-Apr, 15(2), 151 - 6 Spermagglutination by bacteria: receptor-specific interactions; Monga M et al.; The influence of genital infection on infertility has yet to be elucidated . We examined receptor-ligand interactions between sperm and Escherichia coli from patients with prostatitis . Two E . coli surface adhesins (P-fimbriae, type 1 fimbriae) and their specific receptor saccharides (alpha-galp-1-4-beta-galp-O-methyl {gal-gal}, mannose) were evaluated . Bacterial concentrations of 10(4) caused spermagglutination . P-fimbriae caused tail-tail spermagglutination that was inhibited by gal-gal . D-mannose concentrations are highest in the acrosomal region and type 1 fimbriae caused head-head agglutination that was inhibited by mannose . Strains with both fimbriae caused head-head and tail-tail agglutination that was inhibited by a mannose/gal-gal combination . E . coli agglutinated 40-75% of motile sperm . Seminal fluid provided 50-100% protection, with lower effectiveness against type 1 fimbriae . Understanding bacteria-spermatozoa interactions at the receptor-ligand level holds potential for treatment of infertility and development of spermagglutinating contraceptives. Virus Res, 1994 Mar, 31(3), 291 - 303 Expression of the non-structural protein NS1 of bluetongue virus in bacteria and yeast: identification of two antigenic sites at the amino terminus; Gould AR et al.; cDNA transcribed from bluetongue virus serotype 1 (Australia) dsRNA 5 coding for non-structural protein NS1 was amplified in a polymerase chain reaction and ligated downstream of the T7 RNA polymerase promoter in the bacterial expression plasmid pET-5b, as a fusion protein with glutathione S-transferase using the pGEX bacterial expression system or the metallothionein promoter in the yeast expression plasmid pYELC5 . The linear epitopes bound by six monoclonal antibodies to NS1 were localised to two antigenic regions at the amino terminus by Western blots using a series of carboxy-terminal truncations of the NS1 protein overexpressed in Escherichia coli . Expression of truncated NS1 genes using the pGEX expression system in E . coli enabled a more detailed map of the two epitopes to be constructed . The first epitope is thought to lie between amino acid residues 40-59, while the second is defined by the peptide sequences flanking amino acid 96. Microbiology, 1994 Feb, 140 ( Pt 2), 255 - 61 Isolation and characterization of Bordetella parapertussis-like bacteria from ovine lungs; Porter JF et al.; Bacteria resembling two Bordetella species were isolated from both normal and pneumonic ovine lungs using a selective charcoal agar . Twenty-eight of the 33 isolates showed similarities to stock NCTC B . parapertussis strains in their SDS-PAGE gel protein profiles, in their biochemical reactions and in causing browning on tyrosine agar . Five isolates behaved similarly to stock B . bronchiseptica strains, in being actively motile, in giving identical positive reactions in three out of four biochemical tests and in causing no colour change in tyrosine agar . Multilocus enzyme electrophoresis separated the isolates into two electrophoretic types distinguishable from those of stock B . parapertussis and stock B . bronchiseptica strains. J Endod, 1994 Feb, 20(2), 75 - 7 Relationship between clinical symptoms and enzyme-producing bacteria isolated from infected root canals; Hashioka K et al.; The object of this study was to determine the correlation between clinical symptoms and the activity of enzymes such as collagenase, chondroitinase, and hyaluronidase produced by bacteria isolated from infected root canals . The materials examined consisted of 28 teeth with apical periodontitis from 25 patients . Bacteria producing collagenase or chondroitinase and hyaluronidase were found to be significantly related to subacute clinical symptoms involving percussion pain . The frequency of bacteria producing collagenase was higher in isolates from root canals with a radiolucent area over 5 mm in diameter than in those from canals having a radiolucent area less than 5 mm in diameter. Appl Environ Microbiol, 1994 Feb, 60(2), 626 - 36 Phylogenetic analysis and development of probes for differentiating methylotrophic bacteria; Brusseau GA et al.; Fifteen small-subunit rRNAs from methylotrophic bacteria have been sequenced . Comparisons of these sequences with 22 previously published sequences further defined the phylogenetic relationships among these bacteria and illustrated the agreement between phylogeny and physiological characteristics of the bacteria . Phylogenetic trees were constructed with 16S rRNA sequences from methylotrophic bacteria and representative organisms from subdivisions within the class Proteobacteria on the basis of sequence similarities by using a weighted least-mean-square difference method . The methylotrophs have been separated into coherent clusters in which bacteria shared physiological characteristics . The clusters distinguished bacteria which used either the ribulose monophosphate or serine pathway for carbon assimilation . In addition, methanotrophs and methylotrophs which do not utilize methane were found to form distinct clusters within these groups . Five new deoxyoligonucleotide probes were designed, synthesized, labelled with digoxigenin-11-ddUTP, and tested for the ability to hybridize to RNA extracted from the bacteria represented in the unique clusters and for the ability to detect RNAs purified from soils enriched for methanotrophs by exposure to a methane-air atmosphere for one month . The 16S rRNA purified from soil hybridized to the probe which was complementary to sequences present in 16S rRNA from serine pathway methanotrophs and hybridized to a lesser extent with a probe complementary to sequences in 16S rRNAs of ribulose monophosphate pathway methanotrophs . The nonradioactive detection system used performed reliably at amounts of RNA from pure cultures as small as 10 ng. J Bacteriol, 1994 Jan, 176(1), 44 - 9 GTPase-dependent signaling in bacteria: characterization of a membrane-binding site for era in Escherichia coli; Lin YP et al.; Era is an Escherichia coli GTPase that is essential for cell viability and is peripherally associated with the cytoplasmic membrane . Both immunoelectron microscopy and subcellular-fractionation experiments have shown that Era is present in cytoplasmic as well as membrane-associated pools . These data led to speculation that the mechanism of action of Era may require cycling between membrane and cytoplasmic sites . In order to investigate this possibility, an in vitro binding assay was developed to characterize the binding of Era to membrane fractions . Competition and saturation binding experiments suggest that a site that is specific for Era and capable of binding up to 5 ng of Era per microgram of membrane protein is present in membrane preparations . The binding curve is complex, indicating that multiple equilibria describe the interaction . The binding of Era to this putative receptor is dependent on guanine nucleotides; binding cannot be measured in the absence of nucleotide, and neither ATP nor UTP can substitute . Subfractionation of cell walls showed that the guanine nucleotide-dependent binding site was present in fractions enriched in cytoplasmic membrane . These data provide evidence that Era may be involved in a GTPase-receptor-coupled membrane-signaling pathway that is essential for growth in E . coli. Adv Biochem Eng Biotechnol, 1994, 51, 71 - 89 Convective drying of bacteria . II . Factors influencing survival; Lievense LC et al.; In the previous part of this review, the parameters of the drying process that can be important for the survival of bacteria upon drying, were reviewed . In this part the other factors which can be important for survival, will be discussed . The discussion starts with the mechanisms that can be responsible for thermal and dehydration inactivation . Moreover, the influence of storage conditions on the stability of dried bacterial cultures will be reviewed. Int J Syst Bacteriol, 1994 Jan, 44(1), 167 - 71 Assignment of human-derived CDC group 1 coryneform bacteria and CDC group 1-like coryneform bacteria to the genus Actinomyces as Actinomyces neuii subsp . neuii sp . nov., subsp . nov., and Actinomyces neuii subsp . anitratus subsp . nov; Funke G et al.; Almost the entire 16S rRNA gene sequences of some strains of CDC group 1 and group 1-like coryneform bacteria, isolated from human sources, were determined . Comparative analysis of the rRNA sequence data revealed that both groups of coryneforms belong to the genus Actinomyces . On the basis of the present molecular findings and previous biochemical studies, we propose a new Actinomyces species, Actinomyces neuii sp . nov., containing Actinomyces neuii subsp . neuii subsp . nov . for CDC group 1 coryneform bacteria and Actinomyces neuii subsp . anitratus subsp . nov . for CDC group 1-like coryneform bacteria. Curr Opin Periodontol . 1994;:28-38. Modulation of immune responses to periodontal bacteria; Gemmell E et al.; There is little doubt that the interaction between the host immune mechanisms and putative periodontal bacteria is fundamental in the clinical manifestations of the different forms of adult chronic inflammatory periodontal disease . Recent work regarding the function of polymorphonuclear neutrophils indicates that, in addition to their established protective and destructive roles, these cells may have a regulatory function in periodontal disease . Equally, emerging evidence suggests that T-cell responses in adult periodontal disease are antigen specific . Further, the migration and retention of specific T cells in the periodontal tissues appears to be related not to the expression of adhesion molecules but rather to the presence of a specific antigen . T-cell subsets are now characterized on the basis of their cytokine profiles . Type 1 T cells produce interleukin-2 and interferon-gamma, whereas type 2 T cells produce interleukin-4 and interleukin-10 . A hypothesis based on this characterization of T cells is presented . According to this hypothesis, susceptible subjects have a type 2 response, whereas nonsusceptible subjects respond predominantly with type 1 T cells . The possible role of interleukin-12 in controlling this response is highlighted, thus demonstrating the marriage of innate and adaptive immune responses in adult periodontal disease. J Clin Dent, 1994, 4(4), 114 - 9 Relationship between volatile sulfur compounds, BANA-hydrolyzing bacteria and gingival health in patients with and without complaints of oral malodor; De Boever EH et al.; The aim of this study was to obtain measurements of oral malodor, as measured by volatile sulfur compounds (VSC), in periodontally healthy individuals without any complaints of bad breath, and to compare the results with data obtained from patients with complaints of oral malodor . The quality of the mouth air was assessed organoleptically and a portable sulfide monitor was used to measure the concentration of VSC in mouth air . The gingival health of 35 individuals (21 M, 14 F; ages 18-57 years) without any malodor complaints was evaluated according to the Papillary Bleeding Score (PBS) . Pocket depths and Bleeding upon Probing (BOP) were also recorded in 20 patients (11 females and 9 males ranging in age from 14 to 71 years) who complained of oral malodor . Scrapings of the dorsal surface of the tongue and each of 6 plaque samples per patient were evaluated for the presence of BANA-positive species, such as T . denticola, P . gingivalis, and B . forsythus . The organoleptic ratings and VSC values were significantly higher in the complaint group (p < 0.05) . Subjects in the complaint group had a significantly higher percentage of bleeding sites (p < 0.005) and had significantly more plaques that tested positive for the presence of BANA-hydrolyzing species (p < 0.05) . Tongue scrapings of subjects with a high organoleptic score consistently yielded a positive BANA reaction suggesting that the dorsal surface of the tongue is an important niche for BANA-positive, VSC-producing bacteria . This study suggests that the primary sources of VSC production are BANA-hydrolyzing bacteria in the plaque and on the dorsal surface of the tongue. Microbiol Immunol, 1994, 38(4), 287 - 93 Detection of antibody-coated bacteria in expectorated sputum for diagnosis of lower respiratory infections; Matsumoto T et al.; We evaluated antibody-coated bacteria (ACB) in expectorated sputum to discriminate contaminating or colonizing organisms from true pathogens . We examined 60 expectorated sputum samples from 51 patients with lower respiratory infections (chronic obstructive pulmonary disease 25, pneumonia 20, purulent tracheobronchitis 6) . All samples were examined with quantitative culture and immunofluorescent demonstration of ACB . From the results of quantitative culture, we divided specimens into pathogen-isolated and pathogen-free samples . Among pathogen-isolated samples, in which we isolated accepted pathogenic organisms at > or = 10(7) colony-forming units per ml, 16 of 23 samples were ACB-positive (69.5%) . In contrast, among pathogen-free samples, in which we isolated accepted pathogens at < 10(7) colony forming units per ml or only upper respiratory flora, only 3 of 37 samples were ACB-positive (8.1%) . The ACB-positive rate was significantly higher in pathogen-isolated than in pathogen-free samples (P < 0.001) . Consequently, detecting ACB in expectorated sputum shows good potential as another criterion for distinguishing contaminating or colonizing organisms from true pathogens. Can J Microbiol, 1994 Jan, 40(1), 67 - 71 Molecular analysis of archael flagellins: similarity to the type IV pilin-transport superfamily widespread in bacteria; Faguy DM et al.; Ultrastructural, biochemical and genetic evidence has shown that the flagella and flagellin proteins from members of the archaea are distinct from their bacterial counterparts . The most important evidence is the sequence dissimilarity between archael and bacterial flagellins . We report here similarity between archael flagellins and members of the bacterial type IV pilin-transport superfamily . In addition to sequence similarity, the archael flagellins and the type IV pilin-transport superfamily share an unusual signal sequence cleavage site and may have functional parallels . This relationship has important implications for the assembly and biogenesis of archael flagella. Biochimie, 1994, 76(7), 655 - 65 Localization and specificity of cytochromes and other electron transfer proteins from sulfate-reducing bacteria; Le Gall J et al.; Recently data have accumulated concerning the electron transfer chains of sulfate-reducing bacteria in general and of the genus Desulfovibrio in particular . Because of the ever growing number of newly discovered individual redox proteins, it has become essential to try to assign them to physiologically relevant chains . This work presents some new data concerning the localization of these proteins within the bacterial cell and the specificity of electron transfer between the three types of hydrogenases which have been found so far in Desulfovibrio, namely the iron-only, the iron-nickel and the iron-nickel-selenium enzymes . The iron-only hydrogenase reduces cytochromes which have bis-histidinyl heme ligation or histidinyl-methionyl heme ligation . In contrast, the iron-nickel and iron-nickel-selenium hydrogenases cannot reduce cytochromes having a His-Met heme ligation, but are very active toward the cytochromes having a bis-histidinyl ligand . This observation has been used to demonstrate that the tetraheme cytochrome c3 can exchange electrons with the monoheme cytochrome c553 . No clear specificity has been established for the reaction of hydrogenases toward the hexadecaheme cytochromes from either D vulgaris or D gigas. Biochimie, 1994, 76(6), 569 - 79 Interaction between cytochrome c and the photosynthetic reaction center of purple bacteria: behaviour at low temperature; Mathis P et al.; In purple photosynthetic bacteria the electron donor to the special pair, after its oxidation by a light-induced reaction, is a c-type cytochrome: either a soluble monoheme cytochrome which forms a transitory complex with the reaction center, or a tetraheme cytochrome which remains permanently bound to the reaction center . The effects of low temperatures on electron transfer in the complex are presented and discussed . They provide estimates for the reorganization energy . The most prominent effect of low temperature is that a dominant fast phase of electron transfer becomes impossible at a temperature of around 250 K (monoheme cytochrome) or located between 250 K and 80 K according to the redox state (tetraheme cytochrome) . This inhibition is attributed to a freezing-like transition of pools of water molecules which blocks structural changes of the protein which are normally associated with the cytochrome oxidation. Ciba Found Symp, 1994, 180, 228 - 38; discussion 238-46 Haem d1 and other haem cofactors from bacteria; Chang CK; Several bacterial haem prosthetic groups whose structures deviate significantly from the ubiquitous protohaem (Fe-protoporphyrin) have been discovered recently . These newly discovered pigments contain dramatic modifications in their aromatic core and/or side chains . Examples include the dioxoisobacteriochlorin-type haem d1 and the chlorin-type haem d as well as the haem a-like haem o . Total syntheses of these macrocycles have been accomplished . Synthetic haem d1 and its analogues were used in reconstitution studies with nitrite reductase which revealed the importance of the oxo groups and the acrylate side chain for enzymic activity . The structural features of these porphyrinoids immediately suggest some possible, but as yet unproven, biosynthetic pathways. Annu Rev Microbiol, 1994, 48, 223 - 56 Pathways and mechanisms in the biogenesis of novel deoxysugars by bacteria; Liu HW et al.; Science has long recognized the ubiquitously occurring deoxysugars as a novel and important class of carbohydrate, by virtue of the variety of potent and intriguing biological activities they exhibit . The study of the biosynthesis of these naturally vital molecules at a molecular level has received a great deal of attention in recent years, whether it be the well-established study of deoxyribonucleotide biosynthesis via ribonucleotide reductase or newer areas that include 3,6-dideoxyhexose construction and O antigen variation, as well as the emerging scrutiny of the biosynthesis of deoxysugar ligands of antibiotics and cardiac glycosides . This review attempts to update the various classes of deoxy, dideoxy, trideoxy, branched-chain, and amino sugars with respect to our current knowledge regarding the vast biological activities, genetics of formation, and molecular basis of their biosynthesis . In particular, the primary focus utilizes CDP-ascarylose biosynthesis, currently the best genetically and biochemically characterized dideoxysugar system, as a basis for comparison and postulation . This review helps display the elegant complexities of these essential natural saccharides and speculates upon tomorrow's potential applications. Antonie Van Leeuwenhoek, 1994, 66(1-3), 151 - 64 Photosynthetic electron transport and anaerobic metabolism in purple non-sulfur phototrophic bacteria; McEwan AG; Purple non-sulfur phototrophic bacteria, exemplified by Rhodobacter capsulatus and Rhodobacter sphaeroides, exhibit a remarkable versatility in their anaerobic metabolism . In these bacteria the photosynthetic apparatus, enzymes involved in CO2 fixation and pathways of anaerobic respiration are all induced upon a reduction in oxygen tension . Recently, there have been significant advances in the understanding of molecular properties of the photosynthetic apparatus and the control of the expression of genes involved in photosynthesis and CO2 fixation . In addition, anaerobic respiratory pathways have been characterised and their interaction with photosynthetic electron transport has been described . This review will survey these advances and will discuss the ways in which photosynthetic electron transport and oxidation-reduction processes are integrated during photoautotrophic and photoheterotrophic growth. Acta Microbiol Immunol Hung, 1994, 41(3), 273 - 81 Bacteria-host relationships in the bivalve mollusc Loripes lucinalis; Herry A et al.; Loripes lucinalis, a lucinid species found in reduced sediments, contains endosymbiotic bacteria within specialized gill cells which contribute to the bivalve's nutrition . An additional bivalve-bacteria association can be seen in the digestive gland where large inclusion bodies filled with rickettsia- or chlamydia-like organisms are observed in the duct and tubule cells . Despite indications of a possible energy parasitism on the part of these endocellular digestive gland bacteria, the digestive epithelium of the host is not significantly damaged by the infection suggesting that this is a generalized and normal bivalve-bacteria association in adults of this species. Arch Immunol Ther Exp (Warsz), 1994, 42(2), 101 - 6 The reduced expression of HLA-class II antigens and adhesion molecules on monocyte surface after phagocytosis of bacteria; Baran J et al.; The reduced expression of HLA-class II antigens (DQ and DP) and some intercellular adhesion molecules (CD11b, CD54 and CD58) was found on monocytes after phagocytosis of bacteria (S . aureus, E . coli, P . aeruginosa, S . enteritidis) but not of latex particles . In contrast, the expression of HLA-DR, CD11a and CD18 was not changed in the course of phagocytosis . The observed changes were related to the amount of phagocytosed bacteria but not to their viability or phagocytosis induced physical changes expressed as the reduction of FSC signal during flow cytometry analysis. FEMS Microbiol Lett, 1993 Dec 15, 114(3), 253 - 7 Membrane fatty acid analysis of Antarctic bacteria; Rotert KR et al.; Randomly selected strains of a bacterial collection of marine sea-ice bacteria from Antarctica were analyzed to obtain a profile of the membrane fatty acids . Results showed that short chain saturated and unsaturated fatty acids were more common in the psychrotrophs when compared to psychrophiles . In contrast, branched-chain fatty acids were more abundant in the psychrophiles. J Virol Methods, 1993 Dec 15, 45(2), 179 - 88 The use of African horse sickness virus VP7 antigen, synthesised in bacteria, and anti-VP7 monoclonal antibodies in a competitive ELISA; Wade-Evans AM et al.; A full-length cDNA clone of genome segment 7 of African Horse Sickness Virus, serotype 9 (AHSV9) was obtained using the PCR technique . The clone was sequenced and found to be 98.27% homologous to the previously published sequence of the equivalent cDNA clone from AHSV4 at the nucleotide level and to exhibit 99.7% identity at the amino acid level . The cDNA clone was transferred to pGEX-2T (Pharmacia), a bacterial expression vector, such that the reading frame of AHSV9 VP7 was continuous with that of the bacterial glutathione-S-transferase (GST) protein, under the control of the bacterial tac promoter . On induction with IPTG a fusion protein consisting of GST and VP7 was synthesised, which was readily purified on a GST-sepharose column (Pharmacia) . The fusion protein reacted equally well in an indirect ELISA using monoclonal antibodies specific for AHSV9 VP7 or polyclonal guinea pig antisera raised against AHSV9 infectious sub-viral particles . This protein was also shown to be a suitable substitute for virus antigen, prepared from infected BHK cell extracts, in a competitive ELISA . Antibodies titres recorded for AHSV9 positive and negative horse sera were similar in the competitive ELISA using either bacterial AHSV VP7 or BHK extracted virus as the source of antigen, in combination with monoclonal or polyclonal antibodies, respectively, as the detectors. J Biol Chem, 1993 Dec 5, 268(34), 26018 - 25 Structural and functional characterization of the HPV16 E7 protein expressed in bacteria; Pahel G et al.; The E7 gene of the human papillomaviruses (HPV) encodes a 98-amino acid, multifunctional nuclear phosphoprotein with functional and structural similarities to adenovirus E1A and the papovavirus T antigens . E7 is a viral oncoprotein, which will cooperate with an activated ras oncogene to transform primary rodent cells, and can cooperate with the HPV E6 protein for the efficient immortalization of primary human keratinocytes . Due to the compelling epidemiological and experimental association between HPV infection and cervical cancer, we have undertaken a detailed study of the structure of the HPV16 E7 protein . The E7 protein was expressed in Escherichia coli as a native, unfused polypeptide, and soluble protein was purified by conventional chromatographic techniques . The purified protein was assessed for various biochemical and biophysical properties . Purified E7 binds the retinoblastoma protein avidly and specifically, and it can dissociate the E2F transcription factor when assayed in vitro . Circular dichroism spectroscopy indicated that E7 reversibly binds Zn2+ and Cd2+, resulting in a substantial increase in the alpha-helical content of the metal-bound E7 consistent with the stabilization of a hydrophobic core in the COOH terminus of the protein. Epidemiol Infect, 1993 Dec, 111(3), 499 - 502 Intracellular growth of Legionella pneumophila serogroup 1 monoclonal antibody type 2 positive and negative bacteria; Edelstein PH et al.; Epidemiological evidence suggests that monoclonal antibody type 2 positive (MAB 2+) Legionella pneumophila serogroup 1 (LP1) more often causes disease than do MAB 2- isolates, and there is evidence that MAB 2- LP1 grow less well in cells than do MAB 2+ bacteria . We tested the intracellular growth rates of ten randomly selected MAB 2- LP1 isolates, by using guinea-pig alveolar macrophages, and human monocyte-derived macrophages . Save a low virulence control, all ten MAB 2- isolates grew as well in cells as a virulent MAB 2+ isolate . Heterogeneity of MAB 2- LP1 growth in cells exists, making poor intracellular growth an unlikely explanation for why MAB 2+ LP1 appear to cause disease more often. Carcinogenesis, 1993 Dec, 14(12), 2633 - 6 Intestinal bacteria and endogenous production of malonaldehyde and alkylators in mice; Kautiainen A et al.; Association of intestinal bacteria with endogenous production of some reactive compounds was studied by determination of adducts to haemoglobin in blood from germ-free and corresponding control mice . N-terminal valines in haemoglobin were analysed with regard to adducts from malonaldehyde (MA), ethene/ethylene oxide, propene/propylene oxide and methylating agents . It was found that the adduct levels from MA were 1.65 and 3.32 nmol/g globin in germ-free and control mice, respectively . The levels of adducts from ethylene oxide and propylene oxide were 10.8 and 10.3 pmol/g globin, respectively, in germ-free and 21.7 and 17.7 pmol/g globin, respectively, in control mice . The level of adducts from endogenous methylating agents was higher in germ-free mice than in controls (473 and 408 pmol/g globin, respectively) . These differences in adduct levels between germ-free and conventional mice are statistically significant . The causes of the observed variations are so far not identified . This study confirms earlier findings on background levels of adducts in unexposed individuals and supports the hypothesis that these adducts reflect the occurrence of reactive intermediates in vivo that may constitute cancer risks in background cancer incidence . The present study also shows that intestinal bacteria may be an important determinant of such endogenous risk factors. Hua Xi Yi Ke Da Xue Xue Bao, 1993 Dec, 24(4), 392 - 4 {Spiral shaped bacteria in the human gastric biopsy}; Chen Z et al.; Biopsy specimens from the gastric mucosa of 149 patients who underwent gastroduodenal endoscopy for upper gastrointestinal complaints were studied by light microscopy and culture . Spiral shaped bacteria were detected in four of the specimens by smears with Gram stain . The positive rate was 2.68%, but these bacteria and HP did not grow in culture . The characteristic helical morphology of the bacteria appears to be similar to that of the bacteria found in the stomach of cats and dogs . And what of significance in these cases is the presence of spiral shaped bacteria in association with chronic gastritis. PCR Methods Appl, 1993 Dec, 3(3), 181 - 5 Effect of amplicon size on PCR detection of bacteria exposed to chlorine; McCarty SC et al.; The effect of amplicon size on the PCR detection of Legionella pneumophila after chlorine inactivation was investigated . Two amplicons specific to the L . pneumophila mip gene were used for the PCR analyses: a 650-bp amplicon and smaller 168-bp amplicon within the 650-bp amplicon; a 108-bp amplicon specific to species rRNA coding sequence also was used . After exposure to chlorine, viable agar grown cells were not detected by plate counts or direct counts with p-iodonitrotetrazolium (INT) after 1 min for treatment at 10 mg/l, after 2 min for treatment at 5 mg/l, and after 4 min for treatment at 2.5 mg/l; viable water grown cells were present at least 4 min after biocide addition even with a chlorine dose of 5 mg/l . At the 10-mg/l dosage, PCR products from the 168-bp amplicon were detected on agarose gels up to 16 min after chlorination; even after 24 hr of PCR the 168-bp products were detectable using a capture probe hybridization assay . However, the 650-bp target was not detected after 4 min chlorine contact time at the same biocide dosage using agarose gels, and PCR products could not be detected by hybridization after 32 min . At lower chlorine concentrations, a similar pattern was seen with the 168-bp amplicon detectable longer after biocide addition than the 650-bp mip amplification target . On the basis of these data, larger amplicons appear to correlate better with viability of L . pneumophila in water samples. Curr Opin Genet Dev, 1993 Dec, 3(6), 849 - 54 The accessory genetic elements of