Yellow causative agent Green symptoms unique to disease Light Blue toxins virulence factors Purple vaccine Violet specific medicine Nervous System Nervous System lies entirely within body tissues Has no normal microbiota CSF is generally sterile Presence of microbes indicates infection Spinal tap or lumbar puncture used to obtain sample Bloodstream is chief source of CNS infections Blood brain barrier is special cells lining capillaries in CNS difficult for infections and antibiotics to cross Causative agent Streptococcus pneumonia Nervous system diseases Pneumococcal meningitis Gram Capsule Symptoms Begins like mild cold Deafness confusion loss of consciousness coma may develop and Followed by sudden onset of severe throbbing headache Fever pain stiffness of neck and back nausea and vomiting death may occur rapidly Pathogenesis Common cause of otitis media sinusitis and pneumonia can precede pneumococcal meningitis Encapsuled strains resist phagocytosis may enter blood stream bind to receptors on meningeal cells pass into CSF and cause meningitis damage mostly due to inflammatory response Fluids accumulate cause swelling clots in capillaries can block blood supply and lead to tissue death Mortality and neurological damage more common with this type of meningitis than other types Impairment of mucociliary escalator can allow S pneumonia to enter lungs from throat or nasopharynx Bacteremia seen in most cases trauma can allow Pathogen spread by respiratory droplets only very few who are infected will develop meningitis Prevention and Treatment Penicillin unless resistant strain Epidemiology Vaccines against 23 most common capsular antigens not effective in children because of polysaccharide antigens are T cell independent Newer conjugative vaccines developed for children Meningococcal Meningitis Causative agent Neisseria meningitides Gram Symptoms Pathogenesis Encapsulated Can vary antigens easily acquire DNA via horizontal gene transfer Similar to pneumococcal meningitis Distinguished by presence of purpilish spots on skin petechiae Endotoxin shock can lead to rapid death Inhaled in airborne droplets Pili attach to mucous membrane and multiply Proteins in outer membrane allow passage through epithelial cells lining respiratory tract Cells can enter bloodstream and reach meninges rare Release blebs of outer membrane endotoxin shock causes vasodilation and capillary leakage drop in BP Endotoxin shock results when BP is so low that O2 insufficiently supplied Capillary damage causes petechiae Capsule protects from phagocytosis complement system numerous neutrophils enter CSF but bacteria multiply faster than can be destroyed Epidemiology Transmission from exposure to person with disease or asymptomatic carrier Most cases sporadic Immunization has decreased incidence in babies meningitis belt Prevention and Treatment Vaccine of purifies A C Y and W135 capsular polysaccharides New conjugated vaccine also available Recommended for all ages 11 18 and 2 55 at increased risk No vaccine for B strain due to poor immunogenic polysaccharide Penicillin of ceftriaxone if treated in time Haemophilus influenzae meningitis Causative agents Haemophilus influenza Gram Type b Hib causes most serious disease Unencapsulated pleomorphic forms cause most disease in adults Symptoms As with other meningitis begin with cold Pathogenesis Progress to severe headache fever vomiting Older children may have stiff neck Infants may show bulging fontanelle gap between plates of infants skull Encapsulated H influenzae in upper respiratory tract can bind to and penetrate epithelium with aid of pili Enter capillaries bacteremia meningitis Capsule helps resist phagocytosis Unencapsulated strains don t enter bloodstream Epidemiology Usually does not cause epidemics Healthy adult carriers often source of sporadic spread Children rarely carry Hib due to vaccines Pathogen spread by respiratory droplets Prevention and Treatment Conjugate Hib vaccine has type b polysaccharide plus bacterial protein for response Chidren 2 respond poorly to polysaccharide Given more than once Cefotaxime or ceftriazone usually successful People in close contact given rifampin preventatively Listeriosis Causative agents Listeria monocytogenes Gram Falcultative anaerobic Symptoms Pathogenesis Infections generally asymptomatic or mild in most healthy people If symptomatic fever muscle aches sometimes nausea or diarrhea Most cases requiring attention have meningitis with fever headache stiff neck and vomiting Pregnant women often miscarry or deliver terminally ill premature or full term infants Results from foodborne disease listeriosis Mode of entry sporadic and unclear During epidemics usually via gastrointestinal tract Bacteria penetrate intestinal mucosa through M cells and into Peyers patches and enter bloodstream Bacteremia is source of meningeal infection In pregnant women crosses placenta produces widespread abscesses in fetal tissues Babies infected at birth usually develop meningitis after incubation of 1 4 wks Epidemiology Widespread in natural waters and vegetation Prevention and Treatment Can be carried in intestines of asymptomatic humans and animals Pregnant women elderly and those with underlying illnesses especially susceptible Can grow in commercially prepared food stored at refrigeration temps Prevention of cross contamination Killed through cooking Most strains susceptible to antibacterials Pregnant women and others at high risk should avoid soft cheeses refrigerated meats and smoked seafood Bacteriophage mixture that can be sprayed into meats during production Hansen s disease Leprosy Causative agents Mycobacterium leprae Symptoms Pathogenesis nerves Aerobic acid fast Generation time of 12 days prefers slightly cooler temps of extremities Diagnosed by clinical findings but skin biopsies show acid fast rods can give early indication Has not been grown in absence of living cells Gradual onset of pigmentation changes increased or decreased sensation in areas of skin May thicken lose hair sweat glands sensation Nerves of arms legs may become visibly enlarged pain and later numbness Muscle wasting ulceration and finally loss of fingers or toes due to unnoticed or untreated injury More severe thickening of nose and ears deep wrinkling of facial skin collapse of supporting structure of nose Only known human pathogen that preferably infects peripheral Tuberculoid leprosy usually not transmitted to others Cell mediated immunity develops