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Philosophical Transactions of the Royal Society B: Biological Sciences logoLink to Philosophical Transactions of the Royal Society B: Biological Sciences
. 2000 May 29;355(1397):643–656. doi: 10.1098/rstb.2000.0605

Challenge of investigating biologically relevant functions of virulence factors in bacterial pathogens.

R Moxon 1, C Tang 1
PMCID: PMC1692766  PMID: 10874737

Abstract

Recent innovations have increased enormously the opportunities for investigating the molecular basis of bacterial pathogenicity, including the availability of whole-genome sequences, techniques for identifying key virulence genes, and the use of microarrays and proteomics. These methods should provide powerful tools for analysing the patterns of gene expression and function required for investigating host-microbe interactions in vivo. But, the challenge is exacting. Pathogenicity is a complex phenotype and the reductionist approach does not adequately address the eclectic and variable outcomes of host-microbe interactions, including evolutionary dynamics and ecological factors. There are difficulties in distinguishing bacterial 'virulence' factors from the many determinants that are permissive for pathogenicity, for example those promoting general fitness. A further practical problem for some of the major bacterial pathogens is that there are no satisfactory animal models or experimental assays that adequately reflect the infection under investigation. In this review, we give a personal perspective on the challenge of characterizing how bacterial pathogens behave in vivo and discuss some of the methods that might be most relevant for understanding the molecular basis of the diseases for which they are responsible. Despite the powerful genomic, molecular, cellular and structural technologies available to us, we are still struggling to come to grips with the question of 'What is a pathogen?'

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Selected References

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  1. Anderson B. M., Kahn D. W., Anderson C. D. Studies of the 2':3'-cyclic nucleotide phosphodiesterase of Haemophilus influenzae. J Gen Microbiol. 1985 Aug;131(8):2041–2045. doi: 10.1099/00221287-131-8-2041. [DOI] [PubMed] [Google Scholar]
  2. Bajaj V., Lucas R. L., Hwang C., Lee C. A. Co-ordinate regulation of Salmonella typhimurium invasion genes by environmental and regulatory factors is mediated by control of hilA expression. Mol Microbiol. 1996 Nov;22(4):703–714. doi: 10.1046/j.1365-2958.1996.d01-1718.x. [DOI] [PubMed] [Google Scholar]
  3. Balaban N., Goldkorn T., Nhan R. T., Dang L. B., Scott S., Ridgley R. M., Rasooly A., Wright S. C., Larrick J. W., Rasooly R. Autoinducer of virulence as a target for vaccine and therapy against Staphylococcus aureus. Science. 1998 Apr 17;280(5362):438–440. doi: 10.1126/science.280.5362.438. [DOI] [PubMed] [Google Scholar]
  4. Behr M. A., Wilson M. A., Gill W. P., Salamon H., Schoolnik G. K., Rane S., Small P. M. Comparative genomics of BCG vaccines by whole-genome DNA microarray. Science. 1999 May 28;284(5419):1520–1523. doi: 10.1126/science.284.5419.1520. [DOI] [PubMed] [Google Scholar]
  5. Belgrader P., Benett W., Hadley D., Richards J., Stratton P., Mariella R., Jr, Milanovich F. PCR detection of bacteria in seven minutes. Science. 1999 Apr 16;284(5413):449–450. doi: 10.1126/science.284.5413.449. [DOI] [PubMed] [Google Scholar]
  6. Bork P., Dandekar T., Diaz-Lazcoz Y., Eisenhaber F., Huynen M., Yuan Y. Predicting function: from genes to genomes and back. J Mol Biol. 1998 Nov 6;283(4):707–725. doi: 10.1006/jmbi.1998.2144. [DOI] [PubMed] [Google Scholar]
  7. Braga P. C., Ricci D. Atomic force microscopy: application to investigation of Escherichia coli morphology before and after exposure to cefodizime. Antimicrob Agents Chemother. 1998 Jan;42(1):18–22. doi: 10.1128/aac.42.1.18. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Brock T. D. Microbial growth rates in nature. Bacteriol Rev. 1971 Mar;35(1):39–58. doi: 10.1128/br.35.1.39-58.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Camilli A., Beattie D. T., Mekalanos J. J. Use of genetic recombination as a reporter of gene expression. Proc Natl Acad Sci U S A. 1994 Mar 29;91(7):2634–2638. doi: 10.1073/pnas.91.7.2634. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Cheng J., Sheldon E. L., Wu L., Uribe A., Gerrue L. O., Carrino J., Heller M. J., O'Connell J. P. Preparation and hybridization analysis of DNA/RNA from E. coli on microfabricated bioelectronic chips. Nat Biotechnol. 1998 Jun;16(6):541–546. doi: 10.1038/nbt0698-541. [DOI] [PubMed] [Google Scholar]
  11. Cohen M. S., Cannon J. G., Jerse A. E., Charniga L. M., Isbey S. F., Whicker L. G. Human experimentation with Neisseria gonorrhoeae: rationale, methods, and implications for the biology of infection and vaccine development. J Infect Dis. 1994 Mar;169(3):532–537. doi: 10.1093/infdis/169.3.532. [DOI] [PubMed] [Google Scholar]
  12. Contag C. H., Contag P. R., Mullins J. I., Spilman S. D., Stevenson D. K., Benaron D. A. Photonic detection of bacterial pathogens in living hosts. Mol Microbiol. 1995 Nov;18(4):593–603. doi: 10.1111/j.1365-2958.1995.mmi_18040593.x. [DOI] [PubMed] [Google Scholar]
  13. DeRisi J. L., Iyer V. R., Brown P. O. Exploring the metabolic and genetic control of gene expression on a genomic scale. Science. 1997 Oct 24;278(5338):680–686. doi: 10.1126/science.278.5338.680. [DOI] [PubMed] [Google Scholar]
  14. Falkow S. Molecular Koch's postulates applied to microbial pathogenicity. Rev Infect Dis. 1988 Jul-Aug;10 (Suppl 2):S274–S276. doi: 10.1093/cid/10.supplement_2.s274. [DOI] [PubMed] [Google Scholar]
  15. Field D., Hood D., Moxon R. Contribution of genomics to bacterial pathogenesis. Curr Opin Genet Dev. 1999 Dec;9(6):700–703. doi: 10.1016/s0959-437x(99)00021-0. [DOI] [PubMed] [Google Scholar]
  16. Fields S., Kohara Y., Lockhart D. J. Functional genomics. Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8825–8826. doi: 10.1073/pnas.96.16.8825. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Finlay B. B., Falkow S. Common themes in microbial pathogenicity revisited. Microbiol Mol Biol Rev. 1997 Jun;61(2):136–169. doi: 10.1128/mmbr.61.2.136-169.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Geiser J. R., van Tuinen D., Brockerhoff S. E., Neff M. M., Davis T. N. Can calmodulin function without binding calcium? Cell. 1991 Jun 14;65(6):949–959. doi: 10.1016/0092-8674(91)90547-c. [DOI] [PubMed] [Google Scholar]
  19. He Q., Viljanen M. K., Arvilommi H., Aittanen B., Mertsola J. Whooping cough caused by Bordetella pertussis and Bordetella parapertussis in an immunized population. JAMA. 1998 Aug 19;280(7):635–637. doi: 10.1001/jama.280.7.635. [DOI] [PubMed] [Google Scholar]
  20. Heithoff D. M., Conner C. P., Hanna P. C., Julio S. M., Hentschel U., Mahan M. J. Bacterial infection as assessed by in vivo gene expression. Proc Natl Acad Sci U S A. 1997 Feb 4;94(3):934–939. doi: 10.1073/pnas.94.3.934. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Hensel M., Shea J. E., Gleeson C., Jones M. D., Dalton E., Holden D. W. Simultaneous identification of bacterial virulence genes by negative selection. Science. 1995 Jul 21;269(5222):400–403. doi: 10.1126/science.7618105. [DOI] [PubMed] [Google Scholar]
  22. Hoffman S. L., Doolan D. L., Sedegah M., Gramzinski R., Wang H., Gowda K., Hobart P., Margalith M., Norman J., Hedstrom R. C. Nucleic acid malaria vaccines. Current status and potential. Ann N Y Acad Sci. 1995 Nov 27;772:88–94. doi: 10.1111/j.1749-6632.1995.tb44734.x. [DOI] [PubMed] [Google Scholar]
  23. Hood D. W., Deadman M. E., Allen T., Masoud H., Martin A., Brisson J. R., Fleischmann R., Venter J. C., Richards J. C., Moxon E. R. Use of the complete genome sequence information of Haemophilus influenzae strain Rd to investigate lipopolysaccharide biosynthesis. Mol Microbiol. 1996 Dec;22(5):951–965. doi: 10.1046/j.1365-2958.1996.01545.x. [DOI] [PubMed] [Google Scholar]
  24. Hooper C. E., Ansorge R. E., Browne H. M., Tomkins P. CCD imaging of luciferase gene expression in single mammalian cells. J Biolumin Chemilumin. 1990 Apr-Jun;5(2):123–130. doi: 10.1002/bio.1170050208. [DOI] [PubMed] [Google Scholar]
  25. Hoppe J. E. Update on respiratory infection caused by Bordetella parapertussis. Pediatr Infect Dis J. 1999 Apr;18(4):375–381. doi: 10.1097/00006454-199904000-00016. [DOI] [PubMed] [Google Scholar]
  26. Huynen M. A., Diaz-Lazcoz Y., Bork P. Differential genome display. Trends Genet. 1997 Oct;13(10):389–390. doi: 10.1016/s0168-9525(97)01255-9. [DOI] [PubMed] [Google Scholar]
  27. Ji G., Beavis R., Novick R. P. Bacterial interference caused by autoinducing peptide variants. Science. 1997 Jun 27;276(5321):2027–2030. doi: 10.1126/science.276.5321.2027. [DOI] [PubMed] [Google Scholar]
  28. Kenny B., Abe A., Stein M., Finlay B. B. Enteropathogenic Escherichia coli protein secretion is induced in response to conditions similar to those in the gastrointestinal tract. Infect Immun. 1997 Jul;65(7):2606–2612. doi: 10.1128/iai.65.7.2606-2612.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Kononen J., Bubendorf L., Kallioniemi A., Bärlund M., Schraml P., Leighton S., Torhorst J., Mihatsch M. J., Sauter G., Kallioniemi O. P. Tissue microarrays for high-throughput molecular profiling of tumor specimens. Nat Med. 1998 Jul;4(7):844–847. doi: 10.1038/nm0798-844. [DOI] [PubMed] [Google Scholar]
  30. Levin B. R., Svanborg Edén C. Selection and evolution of virulence in bacteria: an ecumenical excursion and modest suggestion. Parasitology. 1990;100 (Suppl):S103–S115. doi: 10.1017/s0031182000073054. [DOI] [PubMed] [Google Scholar]
  31. Levinson G., Gutman G. A. Slipped-strand mispairing: a major mechanism for DNA sequence evolution. Mol Biol Evol. 1987 May;4(3):203–221. doi: 10.1093/oxfordjournals.molbev.a040442. [DOI] [PubMed] [Google Scholar]
  32. Lewis D. A., Klesney-Tait J., Lumbley S. R., Ward C. K., Latimer J. L., Ison C. A., Hansen E. J. Identification of the znuA-encoded periplasmic zinc transport protein of Haemophilus ducreyi. Infect Immun. 1999 Oct;67(10):5060–5068. doi: 10.1128/iai.67.10.5060-5068.1999. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Lipsitch M., Moxon E. R. Virulence and transmissibility of pathogens: what is the relationship? Trends Microbiol. 1997 Jan;5(1):31–37. doi: 10.1016/S0966-842X(97)81772-6. [DOI] [PubMed] [Google Scholar]
  34. Lockhart D. J., Dong H., Byrne M. C., Follettie M. T., Gallo M. V., Chee M. S., Mittmann M., Wang C., Kobayashi M., Horton H. Expression monitoring by hybridization to high-density oligonucleotide arrays. Nat Biotechnol. 1996 Dec;14(13):1675–1680. doi: 10.1038/nbt1296-1675. [DOI] [PubMed] [Google Scholar]
  35. Loeb M. R., Smith D. H. Outer membrane protein composition in disease isolates of Haemophilus influenzae: pathogenic and epidemiological implications. Infect Immun. 1980 Dec;30(3):709–717. doi: 10.1128/iai.30.3.709-717.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. MEYNELL G. G., STOCKER B. A. Some hypotheses on the aetiology of fatal infections in partially resistant hosts and their application to mice challenged with Salmonella paratyphi-B or Salmonella typhimurium by intraperitoneal injection. J Gen Microbiol. 1957 Feb;16(1):38–58. doi: 10.1099/00221287-16-1-38. [DOI] [PubMed] [Google Scholar]
  37. MacLaren D. M. The influence of urea on the growth of Proteus mirabilis. Guys Hosp Rep. 1970;119(2):133–143. [PubMed] [Google Scholar]
  38. Mahan M. J., Slauch J. M., Hanna P. C., Camilli A., Tobias J. W., Waldor M. K., Mekalanos J. J. Selection for bacterial genes that are specifically induced in host tissues: the hunt for virulence factors. Infect Agents Dis. 1993 Aug;2(4):263–268. [PubMed] [Google Scholar]
  39. Mahan M. J., Tobias J. W., Slauch J. M., Hanna P. C., Collier R. J., Mekalanos J. J. Antibiotic-based selection for bacterial genes that are specifically induced during infection of a host. Proc Natl Acad Sci U S A. 1995 Jan 31;92(3):669–673. doi: 10.1073/pnas.92.3.669. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Maw J., Meynell G. G. The true division and death rates of Salmonella typhimurium in the mouse spleen determined with superinfecting phage P22. Br J Exp Pathol. 1968 Dec;49(6):597–613. [PMC free article] [PubMed] [Google Scholar]
  41. Mayville P., Ji G., Beavis R., Yang H., Goger M., Novick R. P., Muir T. W. Structure-activity analysis of synthetic autoinducing thiolactone peptides from Staphylococcus aureus responsible for virulence. Proc Natl Acad Sci U S A. 1999 Feb 16;96(4):1218–1223. doi: 10.1073/pnas.96.4.1218. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. McKenney D., Pouliot K. L., Wang Y., Murthy V., Ulrich M., Döring G., Lee J. C., Goldmann D. A., Pier G. B. Broadly protective vaccine for Staphylococcus aureus based on an in vivo-expressed antigen. Science. 1999 May 28;284(5419):1523–1527. doi: 10.1126/science.284.5419.1523. [DOI] [PubMed] [Google Scholar]
  43. Millar A. J., Carré I. A., Strayer C. A., Chua N. H., Kay S. A. Circadian clock mutants in Arabidopsis identified by luciferase imaging. Science. 1995 Feb 24;267(5201):1161–1163. doi: 10.1126/science.7855595. [DOI] [PubMed] [Google Scholar]
  44. Miller J. F., Mekalanos J. J., Falkow S. Coordinate regulation and sensory transduction in the control of bacterial virulence. Science. 1989 Feb 17;243(4893):916–922. doi: 10.1126/science.2537530. [DOI] [PubMed] [Google Scholar]
  45. Moxon E. R., Anderson P. Meningitis caused by Haemophilus influenzae in infant rats: protective immunity and antibody priming by gastrointestinal colonization with Escherichia coli. J Infect Dis. 1979 Oct;140(4):471–478. doi: 10.1093/infdis/140.4.471. [DOI] [PubMed] [Google Scholar]
  46. Moxon E. R. Applications of molecular microbiology to vaccinology. Lancet. 1997 Oct 25;350(9086):1240–1244. doi: 10.1016/S0140-6736(97)03259-5. [DOI] [PubMed] [Google Scholar]
  47. Moxon E. R., Kroll J. S. The role of bacterial polysaccharide capsules as virulence factors. Curr Top Microbiol Immunol. 1990;150:65–85. doi: 10.1007/978-3-642-74694-9_4. [DOI] [PubMed] [Google Scholar]
  48. Moxon E. R. Molecular basis of invasive Haemophilus influenzae type b disease. J Infect Dis. 1992 Jun;165 (Suppl 1):S77–S81. doi: 10.1093/infdis/165-supplement_1-s77. [DOI] [PubMed] [Google Scholar]
  49. Moxon E. R., Murphy P. A. Haemophilus influenzae bacteremia and meningitis resulting from survival of a single organism. Proc Natl Acad Sci U S A. 1978 Mar;75(3):1534–1536. doi: 10.1073/pnas.75.3.1534. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Moxon E. R., Ostrow P. T. Haemophilus influenzae meningitis in infant rats: role of bacteremia in pathogenesis of age-dependent inflammatory responses in cerebrospinal fluid. J Infect Dis. 1977 Feb;135(2):303–307. doi: 10.1093/infdis/135.2.303. [DOI] [PubMed] [Google Scholar]
  51. Moxon E. R., Rainey P. B., Nowak M. A., Lenski R. E. Adaptive evolution of highly mutable loci in pathogenic bacteria. Curr Biol. 1994 Jan 1;4(1):24–33. doi: 10.1016/s0960-9822(00)00005-1. [DOI] [PubMed] [Google Scholar]
  52. Moxon E. R., Schwartz A. D. Heterotropic splenic autotransplantation in the prevention of Haemophilus influenza meningitis and fatal sepsis in Sprague-Dawley rats. Blood. 1980 Nov;56(5):842–845. [PubMed] [Google Scholar]
  53. Moxon E. R., Smith A. L., Averill D. R. Brain carbohydrate metabolism during experimental Haemophilus influenzae meningitis. Pediatr Res. 1979 Jan;13(1):52–59. doi: 10.1203/00006450-197901000-00012. [DOI] [PubMed] [Google Scholar]
  54. Myerowitz R. L., Michaels R. H. Mechanism of potentiation of experimental Haemophilus influenzae type B disease in infant rats by influenza A virus. Lab Invest. 1981 May;44(5):434–441. [PubMed] [Google Scholar]
  55. Ostrow P. T., Moxon E. R., Vernon N., Kapko R. Pathogenesis of bacterial meningitis. Studies on the route of meningeal invasion following Hemophilus influenzae inoculation of infant rats. Lab Invest. 1979 Jun;40(6):678–685. [PubMed] [Google Scholar]
  56. Pallen M. J. Microbial genomes. Mol Microbiol. 1999 Jun;32(5):907–912. doi: 10.1046/j.1365-2958.1999.01427.x. [DOI] [PubMed] [Google Scholar]
  57. Pascopella L., Collins F. M., Martin J. M., Lee M. H., Hatfull G. F., Stover C. K., Bloom B. R., Jacobs W. R., Jr Use of in vivo complementation in Mycobacterium tuberculosis to identify a genomic fragment associated with virulence. Infect Immun. 1994 Apr;62(4):1313–1319. doi: 10.1128/iai.62.4.1313-1319.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  58. Pettersson J., Nordfelth R., Dubinina E., Bergman T., Gustafsson M., Magnusson K. E., Wolf-Watz H. Modulation of virulence factor expression by pathogen target cell contact. Science. 1996 Aug 30;273(5279):1231–1233. doi: 10.1126/science.273.5279.1231. [DOI] [PubMed] [Google Scholar]
  59. Piétu G., Alibert O., Guichard V., Lamy B., Bois F., Leroy E., Mariage-Sampson R., Houlgatte R., Soularue P., Auffray C. Novel gene transcripts preferentially expressed in human muscles revealed by quantitative hybridization of a high density cDNA array. Genome Res. 1996 Jun;6(6):492–503. doi: 10.1101/gr.6.6.492. [DOI] [PubMed] [Google Scholar]
  60. Plaut A. G., Gilbert J. V., Wistar R., Jr Loss of antibody activity in human immunoglobulin A exposed extracellular immunoglobulin A proteases of Neisseria gonorrhoeae and Streptococcus sanguis. Infect Immun. 1977 Jul;17(1):130–135. doi: 10.1128/iai.17.1.130-135.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Quirke P., Mapstone N. The new biology: histopathology. Lancet. 1999 Jul;354 (Suppl 1):SI26–SI31. doi: 10.1016/s0140-6736(99)90246-5. [DOI] [PubMed] [Google Scholar]
  62. Razatos A., Ong Y. L., Sharma M. M., Georgiou G. Molecular determinants of bacterial adhesion monitored by atomic force microscopy. Proc Natl Acad Sci U S A. 1998 Sep 15;95(19):11059–11064. doi: 10.1073/pnas.95.19.11059. [DOI] [PMC free article] [PubMed] [Google Scholar]
  63. Richter-Dahlfors A., Buchan A. M., Finlay B. B. Murine salmonellosis studied by confocal microscopy: Salmonella typhimurium resides intracellularly inside macrophages and exerts a cytotoxic effect on phagocytes in vivo. J Exp Med. 1997 Aug 18;186(4):569–580. doi: 10.1084/jem.186.4.569. [DOI] [PMC free article] [PubMed] [Google Scholar]
  64. Roche R. J., Moxon E. R. Phenotypic variation in Haemophilus influenzae: the interrelationship of colony opacity, capsule and lipopolysaccharide. Microb Pathog. 1995 Feb;18(2):129–140. doi: 10.1016/s0882-4010(95)90117-5. [DOI] [PubMed] [Google Scholar]
  65. Rothbaum R. J., Partin J. C., Saalfield K., McAdams A. J. An ultrastructural study of enteropathogenic Escherichia coli infection in human infants. Ultrastruct Pathol. 1983 Jun;4(4):291–304. doi: 10.3109/01913128309140582. [DOI] [PubMed] [Google Scholar]
  66. Rothbaum R., McAdams A. J., Giannella R., Partin J. C. A clinicopathologic study of enterocyte-adherent Escherichia coli: a cause of protracted diarrhea in infants. Gastroenterology. 1982 Aug;83(2):441–454. [PubMed] [Google Scholar]
  67. Rubin L. G., Moxon E. R. The effect of serum-factor induced resistance to somatic antibodies on the virulence of Haemophilus influenzae type b. J Gen Microbiol. 1985 Mar;131(3):515–520. doi: 10.1099/00221287-131-3-515. [DOI] [PubMed] [Google Scholar]
  68. Rubin L. G., Zwahlen A., Moxon E. R. Role of intravascular replication in the pathogenesis of experimental bacteremia due to Haemophilus influenzae type b. J Infect Dis. 1985 Aug;152(2):307–314. doi: 10.1093/infdis/152.2.307. [DOI] [PubMed] [Google Scholar]
  69. SMITH H., WILLIAMS A. E., PEARCE J. H., KEPPIE J., HARRIS-SMITH P. W., FITZ-GEORGE R. B., WITT K. Foetal erythritol: a cause of the localization of Brucella abortus in bovine contagious abortion. Nature. 1962 Jan 6;193:47–49. doi: 10.1038/193047a0. [DOI] [PubMed] [Google Scholar]
  70. Seiler A., Reinhardt R., Sarkari J., Caugant D. A., Achtman M. Allelic polymorphism and site-specific recombination in the opc locus of Neisseria meningitidis. Mol Microbiol. 1996 Feb;19(4):841–856. doi: 10.1046/j.1365-2958.1996.437970.x. [DOI] [PubMed] [Google Scholar]
  71. Shaw S., Smith A. L., Anderson P., Smith D. H. The paradox of Hemophilus infuenzae type B bacteremia in the presence of serum bactericidal activity. J Clin Invest. 1976 Oct;58(4):1019–1029. doi: 10.1172/JCI108525. [DOI] [PMC free article] [PubMed] [Google Scholar]
  72. Smith H. What happens in vivo to bacterial pathogens? Ann N Y Acad Sci. 1996 Oct 25;797:77–92. doi: 10.1111/j.1749-6632.1996.tb52951.x. [DOI] [PubMed] [Google Scholar]
  73. Stern A., Brown M., Nickel P., Meyer T. F. Opacity genes in Neisseria gonorrhoeae: control of phase and antigenic variation. Cell. 1986 Oct 10;47(1):61–71. doi: 10.1016/0092-8674(86)90366-1. [DOI] [PubMed] [Google Scholar]
  74. Strauss E. J., Falkow S. Microbial pathogenesis: genomics and beyond. Science. 1997 May 2;276(5313):707–712. doi: 10.1126/science.276.5313.707. [DOI] [PubMed] [Google Scholar]
  75. Streisinger G., Okada Y., Emrich J., Newton J., Tsugita A., Terzaghi E., Inouye M. Frameshift mutations and the genetic code. This paper is dedicated to Professor Theodosius Dobzhansky on the occasion of his 66th birthday. Cold Spring Harb Symp Quant Biol. 1966;31:77–84. doi: 10.1101/sqb.1966.031.01.014. [DOI] [PubMed] [Google Scholar]
  76. Suk K., Das S., Sun W., Jwang B., Barthold S. W., Flavell R. A., Fikrig E. Borrelia burgdorferi genes selectively expressed in the infected host. Proc Natl Acad Sci U S A. 1995 May 9;92(10):4269–4273. doi: 10.1073/pnas.92.10.4269. [DOI] [PMC free article] [PubMed] [Google Scholar]
  77. Sykes K. F., Johnston S. A. Linear expression elements: a rapid, in vivo, method to screen for gene functions. Nat Biotechnol. 1999 Apr;17(4):355–359. doi: 10.1038/7908. [DOI] [PubMed] [Google Scholar]
  78. Valdivia R. H., Falkow S. Bacterial genetics by flow cytometry: rapid isolation of Salmonella typhimurium acid-inducible promoters by differential fluorescence induction. Mol Microbiol. 1996 Oct;22(2):367–378. doi: 10.1046/j.1365-2958.1996.00120.x. [DOI] [PubMed] [Google Scholar]
  79. Valdivia R. H., Falkow S. Fluorescence-based isolation of bacterial genes expressed within host cells. Science. 1997 Sep 26;277(5334):2007–2011. doi: 10.1126/science.277.5334.2007. [DOI] [PubMed] [Google Scholar]
  80. Vasmatzis G., Essand M., Brinkmann U., Lee B., Pastan I. Discovery of three genes specifically expressed in human prostate by expressed sequence tag database analysis. Proc Natl Acad Sci U S A. 1998 Jan 6;95(1):300–304. doi: 10.1073/pnas.95.1.300. [DOI] [PMC free article] [PubMed] [Google Scholar]
  81. Velculescu V. E., Zhang L., Vogelstein B., Kinzler K. W. Serial analysis of gene expression. Science. 1995 Oct 20;270(5235):484–487. doi: 10.1126/science.270.5235.484. [DOI] [PubMed] [Google Scholar]
  82. Virji M., Weiser J. N., Lindberg A. A., Moxon E. R. Antigenic similarities in lipopolysaccharides of Haemophilus and Neisseria and expression of a digalactoside structure also present on human cells. Microb Pathog. 1990 Dec;9(6):441–450. doi: 10.1016/0882-4010(90)90062-u. [DOI] [PubMed] [Google Scholar]
  83. Wachtel M. R., Miller V. L. In vitro and in vivo characterization of an ail mutant of Yersinia enterocolitica. Infect Immun. 1995 Jul;63(7):2541–2548. doi: 10.1128/iai.63.7.2541-2548.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  84. Weiser J. N., Love J. M., Moxon E. R. The molecular mechanism of phase variation of H. influenzae lipopolysaccharide. Cell. 1989 Nov 17;59(4):657–665. doi: 10.1016/0092-8674(89)90011-1. [DOI] [PubMed] [Google Scholar]
  85. Weiser J. N., Pan N. Adaptation of Haemophilus influenzae to acquired and innate humoral immunity based on phase variation of lipopolysaccharide. Mol Microbiol. 1998 Nov;30(4):767–775. doi: 10.1046/j.1365-2958.1998.01108.x. [DOI] [PubMed] [Google Scholar]
  86. Weiser J. N., Shchepetov M., Chong S. T. Decoration of lipopolysaccharide with phosphorylcholine: a phase-variable characteristic of Haemophilus influenzae. Infect Immun. 1997 Mar;65(3):943–950. doi: 10.1128/iai.65.3.943-950.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
  87. Weller P. F., Smith A. L., Smith D. H., Anderson P. Role of immunity in the clearance of bacteremia due to Haemophilus influenzae. J Infect Dis. 1978 Oct;138(4):427–436. doi: 10.1093/infdis/138.4.427. [DOI] [PubMed] [Google Scholar]
  88. Wells D., Sherlock J. K., Handyside A. H., Delhanty J. D. Detailed chromosomal and molecular genetic analysis of single cells by whole genome amplification and comparative genomic hybridisation. Nucleic Acids Res. 1999 Feb 15;27(4):1214–1218. doi: 10.1093/nar/27.4.1214. [DOI] [PMC free article] [PubMed] [Google Scholar]
  89. Winson M. K., Camara M., Latifi A., Foglino M., Chhabra S. R., Daykin M., Bally M., Chapon V., Salmond G. P., Bycroft B. W. Multiple N-acyl-L-homoserine lactone signal molecules regulate production of virulence determinants and secondary metabolites in Pseudomonas aeruginosa. Proc Natl Acad Sci U S A. 1995 Sep 26;92(20):9427–9431. doi: 10.1073/pnas.92.20.9427. [DOI] [PMC free article] [PubMed] [Google Scholar]
  90. Winzeler E. A., Shoemaker D. D., Astromoff A., Liang H., Anderson K., Andre B., Bangham R., Benito R., Boeke J. D., Bussey H. Functional characterization of the S. cerevisiae genome by gene deletion and parallel analysis. Science. 1999 Aug 6;285(5429):901–906. doi: 10.1126/science.285.5429.901. [DOI] [PubMed] [Google Scholar]
  91. Zwahlen A., Kroll J. S., Rubin L. G., Moxon E. R. The molecular basis of pathogenicity in Haemophilus influenzae: comparative virulence of genetically-related capsular transformants and correlation with changes at the capsulation locus cap. Microb Pathog. 1989 Sep;7(3):225–235. doi: 10.1016/0882-4010(89)90058-2. [DOI] [PubMed] [Google Scholar]
  92. Zwahlen A., Rubin L. G., Connelly C. J., Inzana T. J., Moxon E. R. Alteration of the cell wall of Haemophilus influenzae type b by transformation with cloned DNA: association with attenuated virulence. J Infect Dis. 1985 Sep;152(3):485–492. doi: 10.1093/infdis/152.3.485. [DOI] [PubMed] [Google Scholar]
  93. Zwahlen A., Rubin L. G., Moxon E. R. Contribution of lipopolysaccharide to pathogenicity of Haemophilus influenzae: comparative virulence of genetically-related strains in rats. Microb Pathog. 1986 Oct;1(5):465–473. doi: 10.1016/0882-4010(86)90008-2. [DOI] [PubMed] [Google Scholar]
  94. de Saizieu A., Certa U., Warrington J., Gray C., Keck W., Mous J. Bacterial transcript imaging by hybridization of total RNA to oligonucleotide arrays. Nat Biotechnol. 1998 Jan;16(1):45–48. doi: 10.1038/nbt0198-45. [DOI] [PubMed] [Google Scholar]

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