Gram negative cocci & coccobacilliNeisseria gonorrhoeae (gonococcus)Gonorrhea, a.k.a. The Clap, the drip, racehorse etc.Case summaryKey information pointing to diagnosisPathogen identificationPathogen identification: Neisseria gonorrhoeaeVirulence factorsVirulence factorsClinical presentationsClinical presentationsClinical presentationsNeisseria meningitidis (meningococcus)Neisseria meningitidisNeisseria meningitidis (menigococcus)Virulence factorsClinical diseaseClinical disease: MeningococcemiaClinical disease: Waterhouse-Friderichsen SyndromediagnosisHaemophilus influenzaeH. influenzaeH. influenzaeVirulence factorsClinical diseasesLaboratory diagnosisPrevention – hib vaccinePasteurella multocidaoverviewBordetella purtusssisB. pertussisClinical diseaseVirulence factorsLaboratory diagnosisTreatment and preventionTreatment and preventionStudy questions – bonus points availableSlide 38Slide 39Slide 40Slide 41GRAM NEGATIVE COCCI & COCCOBACILLIMike Baldwin, Ph.D.March 4th, 2014Neisseria gonorrhoeae (GONOCOCCUS)GONORRHEA, A.K.A. THE CLAP, THE DRIP, RACEHORSE ETC.•Second most common STD (CDC estimates >800,000 cases per year)•Caused by Neisseria gonorrhoeae infection (Gonococcus, GC)• In adolescents (62% of cases between ages 15-24)•Asymptomatic carriage: women > men•Disease: men > womenCASE SUMMARY•Patient is a 19-year-old male who presents with a 24-hour history of dysuria and “purulent” drainage in his underwear •Urine sample obtained in clinic appeared clear, but tested positive for leukocyte esterase•Multiple white blood cells were seen on microscopic examination of urine•Patient reports being sexually active with five or six partners in he past 6 monthsKEY INFORMATION POINTING TO DIAGNOSIS•Patient experiencing difficulty in urination (DYSURIA) coupled with YELLOW URETHRAL DISCHARGE•Positive leukocyte esterase test  WBCs present in urine, suggestive of infection•Presence of intracellular GRAM-NEGATIVE DIPLOCOCCI in WBCs•Patient’s sexual history•DIAGNOSIS: SUSPECTED GONORRHEAPATHOGEN IDENTIFICATIONGram stain of purulent exudate from the urethra shows WBCs containing numerous intracellular Gram-negative diplococciPATHOGEN IDENTIFICATION: Neisseria gonorrhoeaeFermentation Glucose: POSITIVE Maltose: NEGATIVECatalase Test: POSITIVEOxidase Test: POSITIVELEARN HOW TO RECOGNIZE N. g. ON DIFFERENT MEDIA•Thayer Martin Agar (Selective culture medium)•Contains antibiotics to control growth of other bacterial species•Grows on Chocolate Agar•Does not grow on Blood AgarVIRULENCE FACTORSType IV Pilus•“Hair-like” projections allow bacteria to adhere to epithelial tissues•Pili can be assembled/ retracted for motility – “grappling hook”•Undergo antigenic variation  lack of immunityVIRULENCE FACTORS•Porin (Por) proteins - located in outer membrane:•Protection from intracellular killing•Lipo-oligosaccharide (LOS, Endotoxin):•Resistance to serum killing•IgA protease:•Cleaves mucosal IgA antibodiesCLINICAL PRESENTATIONS•Primary site in Men is the Urethra•Urethritis  Dysuria, Polyuria, discharge•Epididymitis•Disseminated lesions on skinCLINICAL PRESENTATIONS•Most women colonized with GC do not have any symptoms (Infectious carriers)•GC colonizes genitourinary tract:•Inflammation of the endocervix•Purulent vaginal discharge•Irregular intermenstrual bleeding•Infection of fallopian tubes  Pelvic inflammatory disease (PID)  Scarring  InfertilityCLINICAL PRESENTATIONS(Ophthalmia neonatorum)Gonococcal conjunctivitisNeisseria meningitidis(MENINGOCOCCUS)Neisseria meningitidis•Approximately 800–1,500 cases of meningococcal disease occur annually in the United States•Humans are the only natural reservoir for N. meningitidis •N. meningitidis is a Gram-negative, aerobic diplococcus that attach to the surface of mucosal cells of the nasopharynx•Bacteria bind to receptors on epithelial cells  passage across BBB or rarely into blood vesselsNeisseria meningitidis (MENIGOCOCCUS)•Classified into 13 serogroups based on the immunologic reactivity of capsular polysaccharides: •Serogroups B, C, and Y each cause approximately 1/3 of meningococcal disease cases in the United States•Transmission is by direct contact with colonized individuals•Outbreaks tend to be clustered (epidemic)•The frequency of carriage varies by age:•5-10 % in adults•25% in teenagers•<1% in young infantsVIRULENCE FACTORS•Type IV Pilus  host attachment, epithelial cell invasion•Capsule  Blocks uptake by professional APCs, prevents intracellular killing•Lipo-oligosaccharide (LOS, Endotoxin)  inflammation  SEPTIC SHOCKCLINICAL DISEASE•Common clinical manifestations of invasive meningococcal disease include meningitis, bacteremia, and pneumonia•Meningitis  headache, fever (40°C), stiff neck, G -ve diplococci in CSF•In a portion of meningitis cases bacteria enter the blood stream to cause meningococcemia•Characteristic petechial or purpuric rash•Diffuse Intravascular Coagulopathy (DIC), Waterhouse-Friderichsen Syndrome, Death (~15% of cases)CLINICAL DISEASE: MENINGOCOCCEMIACLINICAL DISEASE: WATERHOUSE-FRIDERICHSEN SYNDROMENormal Adrenals WHSMost severe form of Meningococcemia  septic shock  massive hemorrhage into adrenal glands  hormonal imbalanceDIAGNOSIS•Grows on Blood Agar (Differs from GC)•Grows on Chocolate Agar/ Thayer Martin Agar•WBCs containing Gram-negative diplococcus in CSF/ blood•Rapid detection: latex agglutinationFermentation Glucose: POSITIVE Maltose: POSITIVECatalase Test: POSITIVEOxidase Test: POSITIVEHaemophilus influenzaeThe first free-living organism to have its genome sequencedH. influenzae•Haemophilus influenzae is a Gram-negative, pleomorphic bacterium•Two flavors: Typeable (A-F) and Non-typeable strainsThe rounded ends of short bacilli make many cells appear round  coccobacilliBacteria can also appear as long chains (pleomorphic nature)Highly fastidious  requires X (hemin) & V (NAD) cofactorsH. influenzae•Haemophilus influenzae is part of our normal microbiota  opportunistic pathogen•Disease develops when the bacteria access “foreign” sites in the bodyVIRULENCE FACTORS•LPS•highly diverse glycoform structure – contributes to both commensal and pathogenic lifestyles•Outer Membrane Proteins (OMPs)•Adhesin proteins•Capsule•Antigen that defines serotype – 6 major classes•Antigen detected in