Bacterial meningitis pathophysiology: Difference between revisions

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==Overview==
==Overview==
Pathogenensis of bacterial meningitis may include the transmission, colonization, invasion and seeding of meninges. It is a complex process involving interaction between bacterial pathogenic elements and host immune response. There may be genetic predisposition to develop infection. The sequence of events that may ensue after bacterial invasion of meninges include injury to the blood brain or blood CSF barrier, disruption of intercellular tight junctions, vasogenic edema, loss of cerebral autoregulation, increased intra cranial pressure, and development of Signs and symptoms due to raised IC pressure. The inflammatory molecules which may play a role in this pathogenic process includes interleukins IL1, IL6, TNF and matrix metalloproteinases.<ref name="pmid1901998">{{cite journal| author=Stephens DS, Farley MM| title=Pathogenic events during infection of the human nasopharynx with Neisseria meningitidis and Haemophilus influenzae. | journal=Rev Infect Dis | year= 1991 | volume= 13 | issue= 1 | pages= 22-33 | pmid=1901998 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1901998  }} </ref><ref name="pmid6416146">{{cite journal| author=Plaut AG| title=The IgA1 proteases of pathogenic bacteria. | journal=Annu Rev Microbiol | year= 1983 | volume= 37 | issue=  | pages= 603-22 | pmid=6416146 | doi=10.1146/annurev.mi.37.100183.003131 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6416146  }} </ref><ref name="pmid3059994">{{cite journal| author=Joiner KA| title=Complement evasion by bacteria and parasites. | journal=Annu Rev Microbiol | year= 1988 | volume= 42 | issue=  | pages= 201-30 | pmid=3059994 | doi=10.1146/annurev.mi.42.100188.001221 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3059994  }} </ref><ref name="pmid19036641">{{cite journal| author=Brouwer MC, de Gans J, Heckenberg SG, Zwinderman AH, van der Poll T, van de Beek D| title=Host genetic susceptibility to pneumococcal and meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2009 | volume= 9 | issue= 1 | pages= 31-44 | pmid=19036641 | doi=10.1016/S1473-3099(08)70261-5 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19036641  }} </ref><ref name="pmid20334849">{{cite journal| author=Brouwer MC, Read RC, van de Beek D| title=Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2010 | volume= 10 | issue= 4 | pages= 262-74 | pmid=20334849 | doi=10.1016/S1473-3099(10)70045-1 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20334849  }} </ref><ref name="pmid23068452">{{cite journal| author=Adriani KS, Brouwer MC, Geldhoff M, Baas F, Zwinderman AH, Paul Morgan B et al.| title=Common polymorphisms in the complement system and susceptiblity to bacterial meningitis. | journal=J Infect | year= 2013 | volume= 66 | issue= 3 | pages= 255-62 | pmid=23068452 | doi=10.1016/j.jinf.2012.10.008 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23068452  }} </ref><ref name="pmid1508247">{{cite journal| author=Quagliarello V, Scheld WM| title=Bacterial meningitis: pathogenesis, pathophysiology, and progress. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 12 | pages= 864-72 | pmid=1508247 | doi=10.1056/NEJM199209173271208 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1508247  }} </ref><ref name="pmid21180625">{{cite journal| author=Hoffman O, Weber RJ| title=Pathophysiology and treatment of bacterial meningitis. | journal=Ther Adv Neurol Disord | year= 2009 | volume= 2 | issue= 6 | pages= 1-7 | pmid=21180625 | doi=10.1177/1756285609337975 | pmc=3002609 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21180625  }} </ref><ref name="pmid12728265">{{cite journal| author=Kim KS| title=Pathogenesis of bacterial meningitis: from bacteraemia to neuronal injury. | journal=Nat Rev Neurosci | year= 2003 | volume= 4 | issue= 5 | pages= 376-85 | pmid=12728265 | doi=10.1038/nrn1103 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12728265  }} </ref>


==Pathophysiology==
==Pathophysiology==
Pathogenesis of bacterial meningitis is a complex process which may occur due to imbalance between the host immune response and [[Virulence factor|virulence]] factors of pathogen causing infection. Following steps may explain the underlying process in a comprehensive way:<ref name=abc>https://www.cdc.gov/meningitis/bacterial.html Accessed on 10th Jan, 2017</ref> <ref name="pmid1901998">{{cite journal| author=Stephens DS, Farley MM| title=Pathogenic events during infection of the human nasopharynx with Neisseria meningitidis and Haemophilus influenzae. | journal=Rev Infect Dis | year= 1991 | volume= 13 | issue= 1 | pages= 22-33 | pmid=1901998 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1901998  }} </ref><ref name="pmid6416146">{{cite journal| author=Plaut AG| title=The IgA1 proteases of pathogenic bacteria. | journal=Annu Rev Microbiol | year= 1983 | volume= 37 | issue=  | pages= 603-22 | pmid=6416146 | doi=10.1146/annurev.mi.37.100183.003131 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6416146  }} </ref><ref name="pmid3059994">{{cite journal| author=Joiner KA| title=Complement evasion by bacteria and parasites. | journal=Annu Rev Microbiol | year= 1988 | volume= 42 | issue=  | pages= 201-30 | pmid=3059994 | doi=10.1146/annurev.mi.42.100188.001221 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3059994  }} </ref><ref name="pmid19036641">{{cite journal| author=Brouwer MC, de Gans J, Heckenberg SG, Zwinderman AH, van der Poll T, van de Beek D| title=Host genetic susceptibility to pneumococcal and meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2009 | volume= 9 | issue= 1 | pages= 31-44 | pmid=19036641 | doi=10.1016/S1473-3099(08)70261-5 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19036641  }} </ref><ref name="pmid20334849">{{cite journal| author=Brouwer MC, Read RC, van de Beek D| title=Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2010 | volume= 10 | issue= 4 | pages= 262-74 | pmid=20334849 | doi=10.1016/S1473-3099(10)70045-1 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20334849  }} </ref><ref name="pmid23068452">{{cite journal| author=Adriani KS, Brouwer MC, Geldhoff M, Baas F, Zwinderman AH, Paul Morgan B et al.| title=Common polymorphisms in the complement system and susceptiblity to bacterial meningitis. | journal=J Infect | year= 2013 | volume= 66 | issue= 3 | pages= 255-62 | pmid=23068452 | doi=10.1016/j.jinf.2012.10.008 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23068452  }} </ref><ref name="pmid1508247">{{cite journal| author=Quagliarello V, Scheld WM| title=Bacterial meningitis: pathogenesis, pathophysiology, and progress. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 12 | pages= 864-72 | pmid=1508247 | doi=10.1056/NEJM199209173271208 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1508247  }} </ref>
Pathogenesis of bacterial meningitis is a complex process which may occur due to imbalance between the host immune response and [[Virulence factor|virulence]] factors of pathogen causing infection. Following steps may explain the underlying process in a comprehensive way: <ref name="pmid1901998">{{cite journal| author=Stephens DS, Farley MM| title=Pathogenic events during infection of the human nasopharynx with Neisseria meningitidis and Haemophilus influenzae. | journal=Rev Infect Dis | year= 1991 | volume= 13 | issue= 1 | pages= 22-33 | pmid=1901998 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1901998  }} </ref><ref name="pmid6416146">{{cite journal| author=Plaut AG| title=The IgA1 proteases of pathogenic bacteria. | journal=Annu Rev Microbiol | year= 1983 | volume= 37 | issue=  | pages= 603-22 | pmid=6416146 | doi=10.1146/annurev.mi.37.100183.003131 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6416146  }} </ref><ref name="pmid3059994">{{cite journal| author=Joiner KA| title=Complement evasion by bacteria and parasites. | journal=Annu Rev Microbiol | year= 1988 | volume= 42 | issue=  | pages= 201-30 | pmid=3059994 | doi=10.1146/annurev.mi.42.100188.001221 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3059994  }} </ref><ref name="pmid19036641">{{cite journal| author=Brouwer MC, de Gans J, Heckenberg SG, Zwinderman AH, van der Poll T, van de Beek D| title=Host genetic susceptibility to pneumococcal and meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2009 | volume= 9 | issue= 1 | pages= 31-44 | pmid=19036641 | doi=10.1016/S1473-3099(08)70261-5 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19036641  }} </ref><ref name="pmid20334849">{{cite journal| author=Brouwer MC, Read RC, van de Beek D| title=Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2010 | volume= 10 | issue= 4 | pages= 262-74 | pmid=20334849 | doi=10.1016/S1473-3099(10)70045-1 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20334849  }} </ref><ref name="pmid23068452">{{cite journal| author=Adriani KS, Brouwer MC, Geldhoff M, Baas F, Zwinderman AH, Paul Morgan B et al.| title=Common polymorphisms in the complement system and susceptiblity to bacterial meningitis. | journal=J Infect | year= 2013 | volume= 66 | issue= 3 | pages= 255-62 | pmid=23068452 | doi=10.1016/j.jinf.2012.10.008 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23068452  }} </ref><ref name="pmid1508247">{{cite journal| author=Quagliarello V, Scheld WM| title=Bacterial meningitis: pathogenesis, pathophysiology, and progress. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 12 | pages= 864-72 | pmid=1508247 | doi=10.1056/NEJM199209173271208 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1508247  }} </ref><ref name="pmid21180625">{{cite journal| author=Hoffman O, Weber RJ| title=Pathophysiology and treatment of bacterial meningitis. | journal=Ther Adv Neurol Disord | year= 2009 | volume= 2 | issue= 6 | pages= 1-7 | pmid=21180625 | doi=10.1177/1756285609337975 | pmc=3002609 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=21180625  }} </ref><ref name="pmid12728265">{{cite journal| author=Kim KS| title=Pathogenesis of bacterial meningitis: from bacteraemia to neuronal injury. | journal=Nat Rev Neurosci | year= 2003 | volume= 4 | issue= 5 | pages= 376-85 | pmid=12728265 | doi=10.1038/nrn1103 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12728265  }} </ref><ref name=abc>https://www.cdc.gov/meningitis/bacterial.html Accessed on 10th Jan, 2017</ref>
===Transmission===
===Transmission===
* [[Hemophilus Influenza|H. influenza type b]] and [[Neisseria meningitis|N. meningitides]] may be transmitted by close contact or prolong contact with patient suffering from meningitis<ref name=abc>https://www.cdc.gov/meningitis/bacterial.html Accessed on 10th Jan, 2017</ref>
* [[Hemophilus Influenza|H. influenza type b]] and [[Neisseria meningitis|N. meningitides]] may be transmitted by close contact or prolong contact with patient suffering from meningitis<ref name=abc>https://www.cdc.gov/meningitis/bacterial.html Accessed on 10th Jan, 2017</ref>
*It may also spread by exchanging throat and respiratory secretions (couging and kissing)
*It may also spread by exchanging throat and respiratory secretions (coughing and kissing)
*[[Listeria monocytogenes]] may spread by eating contaminated food.  
*[[Listeria monocytogenes]] may spread by eating contaminated food.  
*Most people are carriers and do not develop the disease.
*Most people are carriers and do not develop the disease.


===Colonization and evasion of host immune response===
===Colonization and evasion of host immune response===
*Colonization of pathogenic organism involves evasion of host immune response mechanism.  
*Colonization of pathogenic organism involves evasion of host immune response mechanism.
*[[IgA|IgA protease]] produced by bacterial pathogen cleave mucosal IgA antibodies which prevent the bacteria from attachment to the mucosal surface.<ref name="pmid1901998">{{cite journal| author=Stephens DS, Farley MM| title=Pathogenic events during infection of the human nasopharynx with Neisseria meningitidis and Haemophilus influenzae. | journal=Rev Infect Dis | year= 1991 | volume= 13 | issue= 1 | pages= 22-33 | pmid=1901998 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1901998  }}</ref><ref name="pmid6416146">{{cite journal| author=Plaut AG| title=The IgA1 proteases of pathogenic bacteria. | journal=Annu Rev Microbiol | year= 1983 | volume= 37 | issue=  | pages= 603-22 | pmid=6416146 | doi=10.1146/annurev.mi.37.100183.003131 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6416146  }} </ref>
*[[IgA|IgA protease]] produced by bacterial pathogen cleave mucosal IgA antibodies which prevent the bacteria from attachment to the mucosal surface.<ref name="pmid1901998">{{cite journal| author=Stephens DS, Farley MM| title=Pathogenic events during infection of the human nasopharynx with Neisseria meningitidis and Haemophilus influenzae. | journal=Rev Infect Dis | year= 1991 | volume= 13 | issue= 1 | pages= 22-33 | pmid=1901998 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1901998  }}</ref><ref name="pmid6416146">{{cite journal| author=Plaut AG| title=The IgA1 proteases of pathogenic bacteria. | journal=Annu Rev Microbiol | year= 1983 | volume= 37 | issue=  | pages= 603-22 | pmid=6416146 | doi=10.1146/annurev.mi.37.100183.003131 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6416146  }} </ref>
*Once host immune response is evaded, bacteria attach themselves to the mucosa via fimbriae or pilli which facilitate colonization process.
*Once host immune response is evaded, bacteria attach themselves to the mucosa via fimbriae or pilli which facilitate colonization process.
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*Surface encapsulation may play important role in entry of bacterial pathogen across epithelium into blood stream  
*Surface encapsulation may play important role in entry of bacterial pathogen across epithelium into blood stream  
*Blood stream entry of bacterial pathogen may result in activation of [[Complement system|complement]] pathway and inflammatory process<ref name="pmid3059994">{{cite journal| author=Joiner KA| title=Complement evasion by bacteria and parasites. | journal=Annu Rev Microbiol | year= 1988 | volume= 42 | issue=  | pages= 201-30 | pmid=3059994 | doi=10.1146/annurev.mi.42.100188.001221 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3059994  }} </ref>
*Blood stream entry of bacterial pathogen may result in activation of [[Complement system|complement]] pathway and inflammatory process<ref name="pmid3059994">{{cite journal| author=Joiner KA| title=Complement evasion by bacteria and parasites. | journal=Annu Rev Microbiol | year= 1988 | volume= 42 | issue=  | pages= 201-30 | pmid=3059994 | doi=10.1146/annurev.mi.42.100188.001221 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3059994  }} </ref>
*Bacterial capsule helps evasion of complement system and ultimate entry into the CNS through blood brain barrier<ref name="pmid3059994">{{cite journal| author=Joiner KA| title=Complement evasion by bacteria and parasites. | journal=Annu Rev Microbiol | year= 1988 | volume= 42 | issue=  | pages= 201-30 | pmid=3059994 | doi=10.1146/annurev.mi.42.100188.001221 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3059994  }} </ref>
*Bacterial capsule helps evasion of complement system and ultimate entry into the CNS through [[Blood-brain barrier|blood brain barrier]]<ref name="pmid3059994">{{cite journal| author=Joiner KA| title=Complement evasion by bacteria and parasites. | journal=Annu Rev Microbiol | year= 1988 | volume= 42 | issue=  | pages= 201-30 | pmid=3059994 | doi=10.1146/annurev.mi.42.100188.001221 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=3059994  }} </ref>
*Individual genetic susceptibility and immune response determine the severity of infection
*Individual genetic susceptibility and immune response determine the severity of infection


===Meningeal infalmmation===
===Meningeal infalmmation===
*Meningeal inflammation follows bacterial invasion into the blood.  
*Meningeal inflammation follows bacterial invasion into the blood.<ref>{{cite book | last = Kasper | first = Dennis | title = Harrison's principles of internal medicine | publisher = McGraw Hill Education | location = New York | year = 2015 | isbn = 978-0071802154 }}</ref>
*Bacterial entry into brain may occur through highly vascularized areas such as leptomeningeal blood vessels or [[Choroid plexus|choroid plexus.]]  
*Bacterial entry into brain may occur through highly vascularized areas such as leptomeningeal blood vessels or [[Choroid plexus|choroid plexus.]]  
*Intracranial entry of bacterial pathogen through [[tight junctions]] of blood [[CSF]] or blood CNS barrier may occur through special interaction of adhesins and proteins on the surface of [[choroid]] epithelial cells<ref name="pmid6223077">{{cite journal| author=Brown EJ, Joiner KA, Gaither TA, Hammer CH, Frank MM| title=The interaction of C3b bound to pneumococci with factor H (beta 1H globulin), factor I (C3b/C4b inactivator), and properdin factor B of the human complement system. | journal=J Immunol | year= 1983 | volume= 131 | issue= 1 | pages= 409-15 | pmid=6223077 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6223077  }} </ref>
*Intracranial entry of bacterial pathogen through [[tight junctions]] of blood [[CSF]] or blood CNS barrier may occur through special interaction of adhesins and proteins on the surface of [[choroid]] epithelial cells<ref name="pmid6223077">{{cite journal| author=Brown EJ, Joiner KA, Gaither TA, Hammer CH, Frank MM| title=The interaction of C3b bound to pneumococci with factor H (beta 1H globulin), factor I (C3b/C4b inactivator), and properdin factor B of the human complement system. | journal=J Immunol | year= 1983 | volume= 131 | issue= 1 | pages= 409-15 | pmid=6223077 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=6223077  }} </ref>
===Role of inflammatory molecules in the pathogeneis of bacterial meningitis===
===Role of inflammatory molecules in the pathogeneis of bacterial meningitis===
Inflammatory molecules and bacterial components which may play a role in the pathogenesis of bacterial meningitis may include following:<ref name="pmid2643630">{{cite journal| author=Moser R, Schleiffenbaum B, Groscurth P, Fehr J| title=Interleukin 1 and tumor necrosis factor stimulate human vascular endothelial cells to promote transendothelial neutrophil passage. | journal=J Clin Invest | year= 1989 | volume= 83 | issue= 2 | pages= 444-55 | pmid=2643630 | doi=10.1172/JCI113903 | pmc=303700 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2643630  }} </ref><ref name="pmid2010549">{{cite journal| author=Quagliarello VJ, Wispelwey B, Long WJ, Scheld WM| title=Recombinant human interleukin-1 induces meningitis and blood-brain barrier injury in the rat. Characterization and comparison with tumor necrosis factor. | journal=J Clin Invest | year= 1991 | volume= 87 | issue= 4 | pages= 1360-6 | pmid=2010549 | doi=10.1172/JCI115140 | pmc=295174 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2010549  }} </ref>
Inflammatory molecules and bacterial components which may play a role in the pathogenesis of bacterial meningitis may include following:<ref name="pmid2643630">{{cite journal| author=Moser R, Schleiffenbaum B, Groscurth P, Fehr J| title=Interleukin 1 and tumor necrosis factor stimulate human vascular endothelial cells to promote transendothelial neutrophil passage. | journal=J Clin Invest | year= 1989 | volume= 83 | issue= 2 | pages= 444-55 | pmid=2643630 | doi=10.1172/JCI113903 | pmc=303700 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2643630  }} </ref><ref name="pmid2010549">{{cite journal| author=Quagliarello VJ, Wispelwey B, Long WJ, Scheld WM| title=Recombinant human interleukin-1 induces meningitis and blood-brain barrier injury in the rat. Characterization and comparison with tumor necrosis factor. | journal=J Clin Invest | year= 1991 | volume= 87 | issue= 4 | pages= 1360-6 | pmid=2010549 | doi=10.1172/JCI115140 | pmc=295174 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2010549  }} </ref>
*Subcapsular  bacterial surface components-teichoic acid and peptidoglycans<ref name="pmid2010549">{{cite journal| author=Quagliarello VJ, Wispelwey B, Long WJ, Scheld WM| title=Recombinant human interleukin-1 induces meningitis and blood-brain barrier injury in the rat. Characterization and comparison with tumor necrosis factor. | journal=J Clin Invest | year= 1991 | volume= 87 | issue= 4 | pages= 1360-6 | pmid=2010549 | doi=10.1172/JCI115140 | pmc=295174 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2010549  }} </ref>
*Subcapsular  bacterial surface components-teichoic acid and peptidoglycans<ref name="pmid2010549">{{cite journal| author=Quagliarello VJ, Wispelwey B, Long WJ, Scheld WM| title=Recombinant human interleukin-1 induces meningitis and blood-brain barrier injury in the rat. Characterization and comparison with tumor necrosis factor. | journal=J Clin Invest | year= 1991 | volume= 87 | issue= 4 | pages= 1360-6 | pmid=2010549 | doi=10.1172/JCI115140 | pmc=295174 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2010549  }} </ref>
*Bacterial lysins-pneumolysins in strept pneumoniae
*Bacterial lysins-pneumolysins in strept pneumoniae
*Bacterial lipoligosaccharide or lipopolysaccharide-N.meningitides and S.pneumoniae
*Bacterial lipoligosaccharide or [[lipopolysaccharide]]-N.meningitides and S.pneumoniae
*In situ production of inflammatory cytokines such as IL-1, IL-6, TNF, and matrix metalloproteinases<ref name="pmid2643630">{{cite journal| author=Moser R, Schleiffenbaum B, Groscurth P, Fehr J| title=Interleukin 1 and tumor necrosis factor stimulate human vascular endothelial cells to promote transendothelial neutrophil passage. | journal=J Clin Invest | year= 1989 | volume= 83 | issue= 2 | pages= 444-55 | pmid=2643630 | doi=10.1172/JCI113903 | pmc=303700 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2643630  }} </ref><ref name="pmid2010549">{{cite journal| author=Quagliarello VJ, Wispelwey B, Long WJ, Scheld WM| title=Recombinant human interleukin-1 induces meningitis and blood-brain barrier injury in the rat. Characterization and comparison with tumor necrosis factor. | journal=J Clin Invest | year= 1991 | volume= 87 | issue= 4 | pages= 1360-6 | pmid=2010549 | doi=10.1172/JCI115140 | pmc=295174 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2010549  }} </ref>
*In situ production of inflammatory cytokines such as [[IL-1]], [[Interleukin 6|IL-6]], [[TNF]], and [[matrix metalloproteinases]]<ref name="pmid2643630">{{cite journal| author=Moser R, Schleiffenbaum B, Groscurth P, Fehr J| title=Interleukin 1 and tumor necrosis factor stimulate human vascular endothelial cells to promote transendothelial neutrophil passage. | journal=J Clin Invest | year= 1989 | volume= 83 | issue= 2 | pages= 444-55 | pmid=2643630 | doi=10.1172/JCI113903 | pmc=303700 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2643630  }} </ref><ref name="pmid2010549">{{cite journal| author=Quagliarello VJ, Wispelwey B, Long WJ, Scheld WM| title=Recombinant human interleukin-1 induces meningitis and blood-brain barrier injury in the rat. Characterization and comparison with tumor necrosis factor. | journal=J Clin Invest | year= 1991 | volume= 87 | issue= 4 | pages= 1360-6 | pmid=2010549 | doi=10.1172/JCI115140 | pmc=295174 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2010549  }} </ref>


===Sequence of microscopic changes caused by inflammatory molecules===
===Sequence of microscopic changes caused by inflammatory molecules===
*Once inflammation sets in due to combination of bacterial components and host inflammatory cytokines, the sequence of events that causes signs and symptoms may be as follows:<ref name="pmid1508247">{{cite journal| author=Quagliarello V, Scheld WM| title=Bacterial meningitis: pathogenesis, pathophysiology, and progress. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 12 | pages= 864-72 | pmid=1508247 | doi=10.1056/NEJM199209173271208 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1508247  }} </ref>
*Once inflammation sets in due to combination of bacterial components and host inflammatory cytokines, the sequence of events that causes signs and symptoms may be as follows:<ref name="pmid1508247">{{cite journal| author=Quagliarello V, Scheld WM| title=Bacterial meningitis: pathogenesis, pathophysiology, and progress. | journal=N Engl J Med | year= 1992 | volume= 327 | issue= 12 | pages= 864-72 | pmid=1508247 | doi=10.1056/NEJM199209173271208 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1508247 }} </ref><ref name="pmid2105342">{{cite journal| author=Tureen JH, Dworkin RJ, Kennedy SL, Sachdeva M, Sande MA| title=Loss of cerebrovascular autoregulation in experimental meningitis in rabbits. | journal=J Clin Invest | year= 1990 | volume= 85 | issue= 2 | pages= 577-81 | pmid=2105342 | doi=10.1172/JCI114475 | pmc=296461 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2105342 }} </ref>
*Injury to the blood brain or blood CSF barrier
*Injury to the blood brain or blood CSF barrier
*Disruption of intercellular tight junctions
*Disruption of intercellular tight junctions
*Vasogenic edema
*Vasogenic edema
*Loss of cerebral autoregulation
*Loss of cerebral autoregulation<ref name="pmid2105342">{{cite journal| author=Tureen JH, Dworkin RJ, Kennedy SL, Sachdeva M, Sande MA| title=Loss of cerebrovascular autoregulation in experimental meningitis in rabbits. | journal=J Clin Invest | year= 1990 | volume= 85 | issue= 2 | pages= 577-81 | pmid=2105342 | doi=10.1172/JCI114475 | pmc=296461 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=2105342  }} </ref>
*Increased intra cranial pressure
*Increased intracranial pressure
*Signs and symptoms of raised IC pressure
*Signs and symptoms of raised IC pressure


===Inflammatory mediators causing complications of meningitis===
===Inflammatory mediators causing complications of meningitis===
*Inflammatory mediators and molecules such as nitric oxide, reactive oxygen species and amino acids  
*Inflammatory mediators and molecules such as [[nitric oxide]], [[reactive oxygen species]] and amino acids  
*Neuronal damage, neuronal apoptosis, and brain ischemia may result in complications such as infarction, hydrocephalus and brain abscess
*Neuronal damage, neuronal [[apoptosis]], and brain ischemia may result in complications such as infarction, hydrocephalus and brain abscess


===Associated conditons===
===Associated conditons===
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*Diabetes mellitus
*Diabetes mellitus
*Organ transplant
*Organ transplant
*Immunosuppresion


===Role of Genetics===
===Role of Genetics===
*Genetic polymorphism in the individuals may determine the susceptibility to develop bacterial meningitis, the severity of infection and the ability to recover.<ref name="pmid19036641">{{cite journal| author=Brouwer MC, de Gans J, Heckenberg SG, Zwinderman AH, van der Poll T, van de Beek D| title=Host genetic susceptibility to pneumococcal and meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2009 | volume= 9 | issue= 1 | pages= 31-44 | pmid=19036641 | doi=10.1016/S1473-3099(08)70261-5 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19036641  }} </ref>
*Genetic polymorphism in the individuals may determine the susceptibility to develop bacterial meningitis, the severity of infection and the ability to recover.<ref name="pmid19036641">{{cite journal| author=Brouwer MC, de Gans J, Heckenberg SG, Zwinderman AH, van der Poll T, van de Beek D| title=Host genetic susceptibility to pneumococcal and meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2009 | volume= 9 | issue= 1 | pages= 31-44 | pmid=19036641 | doi=10.1016/S1473-3099(08)70261-5 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19036641  }} </ref>
*Single nucleotide polymorphism in the [[complement system]] may determine the increased or decreased susceptibility to develop bacterial meningitis in these patients<ref name="pmid20334849">{{cite journal| author=Brouwer MC, Read RC, van de Beek D| title=Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2010 | volume= 10 | issue= 4 | pages= 262-74 | pmid=20334849 | doi=10.1016/S1473-3099(10)70045-1 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20334849  }} </ref><ref name="pmid23068452">{{cite journal| author=Adriani KS, Brouwer MC, Geldhoff M, Baas F, Zwinderman AH, Paul Morgan B et al.| title=Common polymorphisms in the complement system and susceptiblity to bacterial meningitis. | journal=J Infect | year= 2013 | volume= 66 | issue= 3 | pages= 255-62 | pmid=23068452 | doi=10.1016/j.jinf.2012.10.008 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23068452  }} </ref>
*[[Single nucleotide polymorphism]] in the [[complement system]] may determine the increased or decreased susceptibility to develop bacterial meningitis in these patients<ref name="pmid20334849">{{cite journal| author=Brouwer MC, Read RC, van de Beek D| title=Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis. | journal=Lancet Infect Dis | year= 2010 | volume= 10 | issue= 4 | pages= 262-74 | pmid=20334849 | doi=10.1016/S1473-3099(10)70045-1 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20334849  }} </ref><ref name="pmid23068452">{{cite journal| author=Adriani KS, Brouwer MC, Geldhoff M, Baas F, Zwinderman AH, Paul Morgan B et al.| title=Common polymorphisms in the complement system and susceptiblity to bacterial meningitis. | journal=J Infect | year= 2013 | volume= 66 | issue= 3 | pages= 255-62 | pmid=23068452 | doi=10.1016/j.jinf.2012.10.008 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23068452  }} </ref>
===Gross pathology===
===Gross pathology===
Gross pathological findings of bacterial meningitis may include:<ref name=abc>https://librepathology.org/wiki/Neuropathology#Meningitis Accessed on 11th Jan, 2017</ref>
*Clouded appearance of meninges
*Presence of [[exudate]]
*Obliteration of sulci
*[[Pus]]
*[[Petechia|Petechiae]]
*Cerebral hemorrhages
===Microscopic pathology===
===Microscopic pathology===
Microscopic pathological findings in bacterial meningitis may include the following:<ref name=abc>https://librepathology.org/wiki/Neuropathology#Meningitis Accessed on 11th Jan, 2017</ref>
*Neutrophilic exudate seen in meninges
*Prominent dilated blood vessels
*[[Edema]] and focal inflammation


==References==
==References==
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Latest revision as of 20:34, 29 July 2020

Meningitis main page

Bacterial meningitis Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Meningitis from other Diseases

Epidemiology and Demographics

Risk Factors

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

CT

MRI

Lumbar Puncture

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aysha Anwar, M.B.B.S[2]

Overview

Pathogenensis of bacterial meningitis may include the transmission, colonization, invasion and seeding of meninges. It is a complex process involving interaction between bacterial pathogenic elements and host immune response. There may be genetic predisposition to develop infection. The sequence of events that may ensue after bacterial invasion of meninges include injury to the blood brain or blood CSF barrier, disruption of intercellular tight junctions, vasogenic edema, loss of cerebral autoregulation, increased intra cranial pressure, and development of Signs and symptoms due to raised IC pressure. The inflammatory molecules which may play a role in this pathogenic process includes interleukins IL1, IL6, TNF and matrix metalloproteinases.[1][2][3][4][5][6][7][8][9]

Pathophysiology

Pathogenesis of bacterial meningitis is a complex process which may occur due to imbalance between the host immune response and virulence factors of pathogen causing infection. Following steps may explain the underlying process in a comprehensive way: [1][2][3][4][5][6][7][8][9][10]

Transmission

  • H. influenza type b and N. meningitides may be transmitted by close contact or prolong contact with patient suffering from meningitis[10]
  • It may also spread by exchanging throat and respiratory secretions (coughing and kissing)
  • Listeria monocytogenes may spread by eating contaminated food.
  • Most people are carriers and do not develop the disease.

Colonization and evasion of host immune response

  • Colonization of pathogenic organism involves evasion of host immune response mechanism.
  • IgA protease produced by bacterial pathogen cleave mucosal IgA antibodies which prevent the bacteria from attachment to the mucosal surface.[1][2]
  • Once host immune response is evaded, bacteria attach themselves to the mucosa via fimbriae or pilli which facilitate colonization process.

Invasion and seeding

  • Once colonized, the invasion of bacteria occurs via special adhesion proteins called adhesins.[1]
  • Adhesins may help bacteria to cross epithelial barrier intracellularly or intercellularly.
  • Bacteria seeds transcellularly to enter the intravascular space.
  • Surface encapsulation may play important role in entry of bacterial pathogen across epithelium into blood stream
  • Blood stream entry of bacterial pathogen may result in activation of complement pathway and inflammatory process[3]
  • Bacterial capsule helps evasion of complement system and ultimate entry into the CNS through blood brain barrier[3]
  • Individual genetic susceptibility and immune response determine the severity of infection

Meningeal infalmmation

  • Meningeal inflammation follows bacterial invasion into the blood.[11]
  • Bacterial entry into brain may occur through highly vascularized areas such as leptomeningeal blood vessels or choroid plexus.
  • Intracranial entry of bacterial pathogen through tight junctions of blood CSF or blood CNS barrier may occur through special interaction of adhesins and proteins on the surface of choroid epithelial cells[12]

Role of inflammatory molecules in the pathogeneis of bacterial meningitis

Inflammatory molecules and bacterial components which may play a role in the pathogenesis of bacterial meningitis may include following:[13][14]

Sequence of microscopic changes caused by inflammatory molecules

  • Once inflammation sets in due to combination of bacterial components and host inflammatory cytokines, the sequence of events that causes signs and symptoms may be as follows:[7][15]
  • Injury to the blood brain or blood CSF barrier
  • Disruption of intercellular tight junctions
  • Vasogenic edema
  • Loss of cerebral autoregulation[15]
  • Increased intracranial pressure
  • Signs and symptoms of raised IC pressure

Inflammatory mediators causing complications of meningitis

  • Inflammatory mediators and molecules such as nitric oxide, reactive oxygen species and amino acids
  • Neuronal damage, neuronal apoptosis, and brain ischemia may result in complications such as infarction, hydrocephalus and brain abscess

Associated conditons

Following conditions may increase the susceptibility to develop bacterial meningitis:

  • Trauma to skull
  • HIV
  • Diabetes mellitus
  • Organ transplant
  • Immunosuppresion

Role of Genetics

  • Genetic polymorphism in the individuals may determine the susceptibility to develop bacterial meningitis, the severity of infection and the ability to recover.[4]
  • Single nucleotide polymorphism in the complement system may determine the increased or decreased susceptibility to develop bacterial meningitis in these patients[5][6]

Gross pathology

Gross pathological findings of bacterial meningitis may include:[10]

  • Clouded appearance of meninges
  • Presence of exudate
  • Obliteration of sulci
  • Pus
  • Petechiae
  • Cerebral hemorrhages

Microscopic pathology

Microscopic pathological findings in bacterial meningitis may include the following:[10]

  • Neutrophilic exudate seen in meninges
  • Prominent dilated blood vessels
  • Edema and focal inflammation

References

  1. 1.0 1.1 1.2 1.3 Stephens DS, Farley MM (1991). "Pathogenic events during infection of the human nasopharynx with Neisseria meningitidis and Haemophilus influenzae". Rev Infect Dis. 13 (1): 22–33. PMID 1901998.
  2. 2.0 2.1 2.2 Plaut AG (1983). "The IgA1 proteases of pathogenic bacteria". Annu Rev Microbiol. 37: 603–22. doi:10.1146/annurev.mi.37.100183.003131. PMID 6416146.
  3. 3.0 3.1 3.2 3.3 Joiner KA (1988). "Complement evasion by bacteria and parasites". Annu Rev Microbiol. 42: 201–30. doi:10.1146/annurev.mi.42.100188.001221. PMID 3059994.
  4. 4.0 4.1 4.2 Brouwer MC, de Gans J, Heckenberg SG, Zwinderman AH, van der Poll T, van de Beek D (2009). "Host genetic susceptibility to pneumococcal and meningococcal disease: a systematic review and meta-analysis". Lancet Infect Dis. 9 (1): 31–44. doi:10.1016/S1473-3099(08)70261-5. PMID 19036641.
  5. 5.0 5.1 5.2 Brouwer MC, Read RC, van de Beek D (2010). "Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis". Lancet Infect Dis. 10 (4): 262–74. doi:10.1016/S1473-3099(10)70045-1. PMID 20334849.
  6. 6.0 6.1 6.2 Adriani KS, Brouwer MC, Geldhoff M, Baas F, Zwinderman AH, Paul Morgan B; et al. (2013). "Common polymorphisms in the complement system and susceptiblity to bacterial meningitis". J Infect. 66 (3): 255–62. doi:10.1016/j.jinf.2012.10.008. PMID 23068452.
  7. 7.0 7.1 7.2 Quagliarello V, Scheld WM (1992). "Bacterial meningitis: pathogenesis, pathophysiology, and progress". N Engl J Med. 327 (12): 864–72. doi:10.1056/NEJM199209173271208. PMID 1508247.
  8. 8.0 8.1 Hoffman O, Weber RJ (2009). "Pathophysiology and treatment of bacterial meningitis". Ther Adv Neurol Disord. 2 (6): 1–7. doi:10.1177/1756285609337975. PMC 3002609. PMID 21180625.
  9. 9.0 9.1 Kim KS (2003). "Pathogenesis of bacterial meningitis: from bacteraemia to neuronal injury". Nat Rev Neurosci. 4 (5): 376–85. doi:10.1038/nrn1103. PMID 12728265.
  10. 10.0 10.1 10.2 10.3 https://www.cdc.gov/meningitis/bacterial.html Accessed on 10th Jan, 2017
  11. Kasper, Dennis (2015). Harrison's principles of internal medicine. New York: McGraw Hill Education. ISBN 978-0071802154.
  12. Brown EJ, Joiner KA, Gaither TA, Hammer CH, Frank MM (1983). "The interaction of C3b bound to pneumococci with factor H (beta 1H globulin), factor I (C3b/C4b inactivator), and properdin factor B of the human complement system". J Immunol. 131 (1): 409–15. PMID 6223077.
  13. 13.0 13.1 Moser R, Schleiffenbaum B, Groscurth P, Fehr J (1989). "Interleukin 1 and tumor necrosis factor stimulate human vascular endothelial cells to promote transendothelial neutrophil passage". J Clin Invest. 83 (2): 444–55. doi:10.1172/JCI113903. PMC 303700. PMID 2643630.
  14. 14.0 14.1 14.2 Quagliarello VJ, Wispelwey B, Long WJ, Scheld WM (1991). "Recombinant human interleukin-1 induces meningitis and blood-brain barrier injury in the rat. Characterization and comparison with tumor necrosis factor". J Clin Invest. 87 (4): 1360–6. doi:10.1172/JCI115140. PMC 295174. PMID 2010549.
  15. 15.0 15.1 Tureen JH, Dworkin RJ, Kennedy SL, Sachdeva M, Sande MA (1990). "Loss of cerebrovascular autoregulation in experimental meningitis in rabbits". J Clin Invest. 85 (2): 577–81. doi:10.1172/JCI114475. PMC 296461. PMID 2105342.


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