The Gram-Negative Cocci

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Case Study uA 20-year-old female college student complained of a low-grade fever and pain, redness, and swelling of several of her joints uAspirates from both ankles and an elbow showed many PMNs and gram-negative intracellular and extracellular diplococci uCultures on Thayer-Martin and MacConkey agar failed to produce growth after 5 days of incubation

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Points to Consider uWhat special growth requirements should be available to these organisms to be recovered from clinical samples? uWhat virulence factors do these organisms use to produce disease? uWhat complications may develop from initial forms of infections? uHow are these organisms identified? uOther points to consider

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. The Pathogenic Neisseria Species and Moraxella catarrhalis uGeneral characteristics 4Aerobic, gram-negative diplococci 4Oxidase-and catalase-positive 4Neisseria elongata is an exception (catalase-negative and rod-shaped) 4Exist as usual flora in the upper respiratory and urogenital tracts 4Primary pathogens include N. gonorrhoeae and N. meningitidis

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria gonorrhoeae  Virulence factors  Fimbrae (common pili)- enhance the ability of bacterial cells to adhere to host cells and to each other  Lipopolysaccharide: resembles that of other gram-negative organisms

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria gonorrhoeae: Virulence factors  Outer membrane proteins  Protein I (PI): demonstrated in patients with disseminated disease; also found in rectal cultures of male homosexuals; resistant to serum bactericidal effects 4Protein II (PII): sensitive to bactericidal effects; associated with adherence to mucosal cells 4Protein III (PIII)-major binding site for immunoglobin-G– blocking antibody

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria gonorrhoeae : Clinical Infections uDisease in the male 4Incubation period: 1 to 7 days 4Transmitted only by intimate sexual contact 495% show symptoms of acute infection 4Symptoms include dysuria, urethral discharge 4Complications include epididymitis and urethral stricture, and prostatitis

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria gonorrhoeae : Clinical Infections uDisease in the female 420% to 80% are asymptomatic 4Symptoms (if symptomatic) include burning or frequency of urination, vaginal discharge 4Fever and abdominal pain 4Complications include pelvic inflammatory disease (PID)

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria gonorrhoeae : Infections in Other Sites uDisseminated gonococcal disease 4Acute form has the following symptoms: fever, chills, malaise, intermittent bacteremia, and skin lesions 4If untreated will progress to septic joint form of the disease 4Gonococcal arthritis occur as a result of disseminated gonococcal bacteremia

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria gonorrhoeae : Infections in Other Sites uDisease in children 4In infancy, an eye infection (ophthalmia neonatorum) may occur during vaginal delivery 4Infection is preventable with the application of eye drops at birth uExtragenital infections 4Pharyngitis 4Anorectal infections

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Laboratory Diagnosis: Neisseria gonorrhoeae uClinical specimens 4Genital sites 4Anal- oral/pharyngeal 4Eye 4Blood/joint fluids uTransport media: Transgrow or JEMBEC JEMBEC

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Laboratory Diagnosis: Neisseria gonorrhoeae uIdentification  Morphology  Gram-negative, kidney- bean–shaped diplococci A direct gram-stained smear of male urethral discharge showing intracellular gram- negative diplococci

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Laboratory Diagnosis: Neisseria gonorrhoeae uIdentification 4Inoculated culture media must be incubated at 35 0 C in 3% to 5% CO 2 4Colony morphology on modified Thayer-Martin (MTM) agar FSmall, gray  Translucent, raised

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Laboratory Diagnosis: Neisseria gonorrhoeae Candle extinction jar with inoculated MTM agar plates.

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Laboratory Diagnosis: Neisseria gonorrhoeae uIdentification 4Oxidase test Carbohydrate utilization test; acid produced only in the glucose tube indicates that the isolate is N. gonorrheoae

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria meningitidis uGeneral characteristics 4Exclusively human parasite 4Exist as harmless member of normal upper respiratory flora 4Identical with Neisseria gonorrhoeae uAntigenic structures 4Capsular polysaccharide: nine serotypes— A, B, C, D, X, Y, Z, W135, 29E. 4Contribute to invasive properties by inhibiting phagocytosis

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria meningitidis : Clinical Infections uBacterial meningitis 4Transmission is by respiratory droplets and requires both close contact and lack of specific antibody (susceptibility) 4Symptoms include fever, headache, stiff neck, nausea, vomiting, and purulent meningitis with increased WBCs

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria meningitidis: Clinical Infections uBacteremia (meningococcemia) 4Appearance of skin petechiae Hemorrhage in the adrenal glands in W-F syndrome

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Laboratory Diagnosis: Neisseria meningitidis uIdentification 4Examine direct smear from CSF Gram-stained smear of CSF showing the extracellular and intracellular gram- negative diplococci

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Neisseria meningitidis growing on sheep blood agar (right) and chocolate agar (left) Laboratory Diagnosis: Neisseria meningitidis uIdentification 4Examine cultures on blood agar and chocolate agar plates 4Oxidase-test–positive 4Conventional CTA carbohydrates for biochemical identification or immunologic methods are available for serogrouping

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Other “Related” Species uMoraxella catarrhalis 4Normal commensal of the respiratory tract 4Has become an important opportunistic pathogen uClinical infections 4Pneumonia 4Sinusitis 4Otitis media uPredisposing factors 4Advanced age 4Immunodeficiency 4Neutropenia 4Other debilitating diseases

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. M. catarrhalis Moraxella catarrhalis growing on chocolate agar after 48 hours of incubation Direct smear from an otitis media sample showing intracellular gram-negative diplococci; M. catarrhalis was identified from cultures

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Identification of Selected Neisseria Species

W.B. Saunders Company items and derived items copyright © 2001 by W.B. Saunders Company. Points to Remember uClinically significant Neisseria species uOther related opportunistic pathogens uClinical infections associated with pathogenic species uComplications that may result from these infections uMethods of identifying important species