Neisseria and Moraxella Meningitis, septicaemia, gonorrhoea, respiratory infection

1
Neisseria and MoraxellaMeningitis, septicaemia,
gonorrhoea, respiratory infection
2
Characteristics of Neisseria and Moraxella

• Gram-negative diplococci with adjacent sides
  flattened
• Frequently appear as intracellular gram-negative
  diplococci within polymorphonuclear neutrophils
• Neisseria gonorrhoeae fastidious showing optimal
  growth on enriched chocolate agar

3
embryology.med.unsw.edu.au/Defect/nutrition.htm?
4
(No Transcript)
5
Characteristics of Neisseria and Moraxella

• Growth of Neisseria meningitidis and Moraxella
  catarrhalis occurs on both sheep blood and
  chocolate agar
• Neisseria gonorrhoeae, N. meningitidis, and
  Moraxella catarrhalis capnophilic (optimal growth
  with 3-7 CO2)
• Neisseria meningitidis and N. gonorrhoeae closely
  related genetically and distantly to saprophytic
  species of Neisseria

6
Characteristics of Neisseria and Moraxella

• Neisseria meningitidis encapsulated (capsule the
  major virulence factor)
• Thirteen capsular polysaccharide serogroups
• Invasive infection caused by organisms with one
  of five capsular serogroups (A, B, C, Y, and
  W135) with 90 of meningococcal disease due to
  serogroups A, B, and C

7
Characteristics of Neisseria and Moraxella

• Moraxella rather than Branhamella accepted
  taxonomically as the genus designation for M.
  catarrhalis (family Moraxellaceae)
• Even though M. catarrhalis not a member of the
  family Neisseriaceae, morphologic and biochemical
  similarity to Neisseria allows clinical
  laboratory identification of M. catarrhalis with
  Neisseria species

8
Pathogenic Species

• Neisseria gonorrhoeae
• Neisseria meningitidis
• Moraxella catarrhalis

9
Saprophytic Species

• Neisseria lactamica, N. polysaccharea,
• N. cinera, N. flavescens, N. subflava,
• N. sicca, and N. mucosa

10
Virulence factors

• N. gonorrhoeae - ?infectivity ?severity
  (fortunately)
• Capsule (???) attachment anti-phagocytosis
• Fimbriae/pili specific attachment to urogenital
  columnar epithelial cells
• Lipopolysaccharide (endotoxin) tumor necrosis
  factor
• Cell wall proteins I, II, and III (interfere with
  phagocytosis)
• IgA protease (cleaves IgA on mucosal surfaces)
• N. meningitidis
• Capsule
• Lipopolysaccharide (endotoxin)

11
Neisseria Natural Habitats

• Neisseria gonorrhoeae an obligate pathogen with
  invasive infection of anogenital, oropharyngeal,
  and conjunctival mucous membranes
• Neisseria meningitidis normally colonizes
  oropharyneal and nasopharyngeal mucous membranes
  of humans (carrier rate of 8-20)

12
Neisseria Natural Habitats

• Neisseria meningitidis can colonize anogenital
  mucous membranes of homosexual men
• Saprophytic species are non-pathogenic
  (non-invasive) and normally colonize the
  oropharyngeal and nasopharyngeal mucous membranes
  of humans

13
Moraxella catarrhalis Natural Habitats

• Present in the upper respiratory tract of
  1.5-5.4 of healthy individuals, more commonly in
  children (50.8) and elderly adults (26.5)

14
Neisseria gonorrhoeae Modes of Infection

• Neisseria gonorrhoeae spread by sexual contact,
  including genital, anogenital, and orogenital.
  Spread from infected mother to neonate as ocular
  infection during birth. Non-sexual transmission
  not documented.

15
Neisseria meningitidis Modes of Infection

• Neisseria meningitidis transmitted by inhalation
  of infectious air-born respiratory droplets or
  direct contact with infectious respiratory
  secretions.

16
Neisseria Modes of Infection

• Neisseria meningitidis can be transmitted by
  sexual contact, especially orogenital or
  anogenital intercourse.
• Person-to-person transmission does not occur with
  saprophytic Neisseria species and infection
  (rare) is endogenous.

17
Moraxella catarrhalis Modes of Infection

• Oropharyngeal endogenous strains spread into
  normally sterile regions of the tracheobronchial
  tree, the middle ear, and sinuses

18
Neisseria Types of Infectious Disease

• N. gonorrhoeae second most common cause (after
  Chlamydia trachomatis) of sexually-transmitted
  lower genital tract disease (acute urethritis in
  men, endocervicitis in women)
• N. gonorrhoeae untreated can progress to
  epididymitis, prostatitis, urethral stricture,
  salpingitis, tubo-ovarian abscess, and pelvic
  inflammatory disease

19
Neisseria Types of Infectious Disease

• N. gonorrhoeae causes oral and anorectal
  infections as a result of oral or anal
  intercourse
• N. gonorrhoeae disseminates with bacteremia
  and/or septic arthritis if untreated
• Disseminated infection (bacteremia, pyogenic
  arthritis) by N. meningitidis and N. gonorrhoeae
  associated with deficiency in the terminal
  components of complement (C5-C8)

20
Preventative measures aren't taken gonococcal
ophthalmia neonatorum affects the corneal
epithelium causing microbial keratitis,
ulceration and perforation
21
The bacteria are carried in semen and vaginal
fluids and cause a discharge in men and women.
in women - Bleeding during vaginal intercourse,
Painful or burning sensations when urinating,
Yellow or bloody vaginal discharge in Men -
White, yellow, or green pus from the penis with
pain, Burning sensations during urination that
may be severe, Swollen or painful
testicles Symptoms of rectal infection include
discharge, anal itching, and occasional painful
bowel movements with fresh blood in the feces.
Symptoms typically appear 2 to 5 days after
infection but could appear as long as 30 days.
22
Neisseria Types of Infectious Disease

• N. meningitidis causes a rapidly progressive
  meningitis in school-aged children, adolescents,
  and young adults with a mortality of 7-13
• N. meningitidis bacteremia (mortality of 19-70)
  a cause of Waterhouse-Friderichsen syndrome with
  petechiae, purpura, adrenal hemorrhage,
  disseminated intravascular coagulation (DIC), and
  shock

23
Neisseria Types of Infectious Disease

• Neisseria meningitidis associated
• with sexual transmission and
• gonococcal-like urethritis,
• cervicitis, salpingitis, and proctitis

24
Moraxella catarrhalis Types of Infectious Disease

• Acute purulent exacerbation of chronic bronchitis
• Causes 10-15 of episodes of otitis media and
  sinusitis
• Rarely associated with systemic infection
  (endocarditis, meningitits)

25
Neisseria gonorrhoeae and Neisseria meningitidis
Isolation

• Isolation often attempted from specimens with
  abundant normal flora (genital, oral, anorectal)
  (especially N. gonorrhoeae)
• Modified Thayer-Martin (MTM) agar an enriched and
  selective medium for pathogenic N. gonorrhoeae
  and N. meningitidis
• Nutritive base of MTM is chocolate agar
• Antibiotics present in MTM selective for the
  growth of N. gonorrhoeae and N. meningitidis

26
Modified Thayer-Martin Agar

• Colistin Inhibits gram-negative flora (N.
  gonorrhoeae and N. meningitidis resistant to
  colistin, most saprophyic species of Neisseria
  susceptible)
• Vancomycin Inhibits gram-positive flora
• Nystatin Inhibits yeast flora
• Trimethoprim Inhibits swarming Proteus

27
Neisseria gonorrhoeae Identification

• Off-white colonies on chocolate agar with no
  discoloration of agar
• Acid from glucose but not maltose, sucrose,
  fructose, or lactose
• Positive superoxol test (Catalase with 30 H2O2)
• Colistin resistance (growth on Modified
  Thayer-Martin medium)

28
N. gonorrhoeae
29
Neisseria meningitidis Identification

• Gray colonies on chocolate agar with green haze
  in agar immediately under and adjacent to
  colonies
• Acid from glucose and maltose but not sucrose,
  fructose, or lactose
• Colistin resistance (growth on modified
  Thayer-Martin medium)

30
N. meningitidis
31
Moraxella catarrhalis Identification

• Pink coloration of colonies on chocolate agar not
  apparent on blood agar
• No acid from glucose, maltose, sucrose, fructose,
  or lactose (asaccharolytic)
• Produces DNase
• Possesses the enzyme butyrate esterase

32
M. catarrhalis
33
Selected Biochemical Reactions for Identification
of Neisseria and Moraxella catarrhalis1

• Glu Mal Lac Suc DNa BE
• N. gon
• N. men
• N. lac2
• M. cat
• 1Gluglucose, Malmaltose, Laclactose,
  Sucsucrose, DNaDNase, BEbutyrate esterase
  (indoxyl butyrate substrate), N. gonN.
  gonorrhoeae, N. menN. meningitidis, N. lacN.
  lactamica, M. catMoraxella catarrhalis
• 2Colistin-resistant saprophytic species of
  Neisseria

34
Laboratory Detection and Identification of
Neisseria gonorrhoeae

• Direct PCR detection for urogenital specimens
  with culture confirmation when PCR positive
• Culture isolation and biochemical identification
  for urogential specimens with gonorrhea
  refractory to treatment or sexual abuse, and
  non-urogenital specimens
• Molecular strain typing for isolates of N.
  gonorrhoeae in sexual abuse cases

35
Antimicrobial Therapy

• Was generally susceptible to penicillin in the US
  until 1976 when a pen-resistant strain was
  imported from Southeast Asia. This strain
  proliferated and spread within a few years.
  These strains are now detected using the
  cephalosporin (Cefinase) test
• These strains are referred to as CMRNG
  (chromosome mediated resistant N.gonorrhoeae).
  Tetracycline and Spectinomycin chromosomal
  mediated resistance strains also occur.
• Ceftriaxone, a third generation cephalosporin, is
  recommended
• Penicillin is still the drug of choice for
  treatment of infections caused by N. meningitidis
• Most M. catarrhalis strains produce beta
  lactamase, and are therefore pen-resistant.

36
Showing positive (left disk) and negative (right
disk) reactions for Nitrocef Disks which include
nitrocefin, a chromogenic cephalosporin