L24 Neisseria, Haemophilus, and Bordetella Flashcards
Bacteria in the Neisseria genus are Gram ___ (+/-) ___ (shape).
Negative; diplococci
Bacteria in the Haemophilus genus are Gram ___ (+/-) ___ (shape).
Negative; coccobacilli
Bacteria in the Bordetella genus are Gram ___ (+/-) ___ (shape).
Negative; coccobacilli
Neisseria, Haemophilus, and Bordetella contain ___ in the outer membrane; these are also known as ___.
Lipopolysaccharides (LPS); endotoxin
Describe the process of culturing Neisseria.
- Difficult to grow - require enriched media enhanced by CO2
- Chocolate agar that contains antibiotics
- Oxidase positive
What are the 2 species of Neisseria that cause disease?
- Meningitidis
2. Gonorrhoeae
An immune response to Neisseria requires an intact ___ system.
Complement
What are the virulence factors of N. meiningitidis?
- Polysaccharide capsule
- LPS/LOS
- Type IV pilus
What are the 6 serogroups of polysaccharide capsule that are associated with disease in N. meningitidis?
A, B, C, W135, X, Y
N. meningitidis attaches selectively to ___ cells of the ___. What happens next?
Columnar; nasopharynx; bacteria multiply and form large aggregates. Within a few hours, pili undergo post-translational modification, which leads to destabilization of the aggregates. Bacteria penetrate into the host cells and are released into the airways.
How is N. meningitidis transmitted?
Respiratory droplets
Which serogroups of the capsule are seen in N. meningitidis cases in the developed world?
B, C, Y
Which serogroups of the capsule are seen in N. meningitidis cases in the developing world?
A, W135
Which age group is most affected by meningococcal disease?
Infants and young children to ~9 years old; there is a secondary peak in adolescents and young adults
What are the two possible outcomes of colonization by N. meningitidis?
- Progress to overt clinical disease
2. Become an asymptomatic carrier
What are the two major clinical manifestations of N. meningitidis?
- Meningococcemia
2. Meningitis
What are the three less common clinical manifestations of N. meningitidis?
- Pneumonia
- Arthritis
- Urethritis
What are the symptoms of meningococcemia?
Septic shock, petechical and purpuric rash with bullae, hemorrhage and disseminated intravascular coagulation
What are the symptoms of meningitis?
Can occur with or without meningococcemia;
severe headache, neck stiffness, confusion, fever, neurologic deficits
What can be cultured to test for N. meningitidis?
Blood, CSF, respiratory secretions
What is the treatment for N. meningitidis?
Ceftriaxone, Pencillin G if bacteria are susceptible
How can the close contacts of people with N. meningitids be treated?
Prophylaxis with rifampin, ciprofloxacin, ceftriaxone
What are the two types of vaccinations for N. meningitidis?
- Serogroups A, C, Y, W135 (conjugated polysaccharide vaccine)
- Serogroup B (newer recombinant protein vaccines)
What are the recommendations for the Serogroups A, C, Y, W135 vaccination?
- Adolescents: everyone age 11-12, booster at age 16
- Adults: complement deficiency, functional or anatomic asplenia, microbiologists, outbreak, military recruit, HIV, travel
What are the recommendations for Serogroup B vaccination?
- Adolescents: not required, but can be given for age 16-18
2. Adults: complement deficiency, functional or anatomic asplenia, microbiologists, outbreak
What are the virulence factors of N. gonorrhoeae?
- No capsule
- Outer membrane proteins: Pilin (attachment), Opa (attachment), Rmp (protects other OMPs), PorB (prevents phagolysozyme fusion), Transferrin (bacterial iron metabolism)
What is antigenically varied in N. gonorrhoeae to promote evasion?
Pili
How is N. gonorrhoeae transmitted?
Across mucosal surfaces by direct contact (anogenital tract most common, also oropharyngeal)
___% of women are asymptomatic with N. gonorrhoaea, compared with ___% of men.
50; 5-10
Women have a ___% risk of acquiring N. gonorrhoeae after exposure, compared with ___% risk for men.
50; 20
What are the 5 primary clinical manifestations of N. gonorrhoeae?
- Urethritis
- Cervicitis
- Proctitis
- Pharyngitis
- Neonatal conjunctivitis
What are the 4 secondary clinical manifestations of N. gonorrhoeae?
- Epididymitis/prostatitis
- Endometritis/salpingitis (pelvic inflammatory disease)
- Gonococcemia and septic arthritis
- Dermatitis
What can be tested to culture N. gonorrhoeae?
Urethra, cervix, joint fluid
What is required to culture N. gonorrhoeae?
Chocolate agar and CO2
What are the 5 types of Haemophilus species?
- H. influenzae
- H. parainfluenzae
- H. aphrophilus
- H. ducreyi
- H. aegyptius
What does H. parainfluenzae cause?
Bacteremia, endocarditis
What does H. aphrophilus cause?
Endocarditis
What does H. ducreyi cause?
Chancroid (STI)
What does H. aegyptius cause?
Conjunctivitis
Which Haemophilus species are + for X growth factor?
Influenzae and ducreyi
Which Haemophilus species are + for V growth factor?
Influenzae and parainfluenzae
Which Haemophilus species is + for CO2 growth requirement?
Aphrophilus
How is H. influenzae transmitted?
Respiratory droplets
H. influenzae type ___ was responsible for > 95% of all invasive infections until 1990 when the vaccination was introduced. Now, more than half of all disease is caused by ___ strains.
B; non-encapsulated
What diseases are caused by H. influenzae type B?
- Meningitis
- Epiglottitis
- Septic arthritis
- Pneumonia
- Bacteremia
- Cellulitis
- Osteomyelitis
What diseases are caused by non-encapsulated strains of H. influenzae (type a, d, e)?
- Otitis media
- Sinusitis
- Pneumonia
- Conjunctivitis
What age group is primarily affected by H. influenzae type B? By the non-encapsulated strains?
6 months - 2 years; children and adults
Which type of H. influenzae has a vaccination?
Type B
What can be cultured to look for H. influenzae?
CSF, blood, lower respiratory tract, joint fluid
What is used to treat severe, invasive disease caused by H. influenzae?
2nd and 3rd generation cephalosporins
What is used to treat less severe, non-invasive disease caused by H. influenzae?
Amoxicillin/clavulanate, macrolides, fluoroquinolones, trimethoprim/sulfamethoxazole
Describe culture and growth of bordetella pertussis.
- Strict aerobe, non-motile, non-spore forming
- Catalase +
- Difficult to grow (sensitive to drying, susceptible to toxic substances, metabolites, agar supplemented with charcoal, starch, blood, albumin)
What are the virulence factors of B. pertussis?
- Filamentous hemagglutinin
- LPS/LOS
- Pertussis toxin (PT)
- Tracheal cytotoxin
- Adenylate cyclase toxin
What does adenylate cyclase toxin do?
Increase cAMP levels in cells
What does pertussis toxin do?
Inactivates the protein controlling adenylate cyclase, leading to higher cAMP levels
How is B. pertussis spread?
Respiratory droplets
B. pertussis is most common and severe in what population?
Infants from birth-2 years
What are the 4 stages of B. pertussis and how long are they?
- Incubation (7-10 days)
- Catarrhal (1-2 weeks)
- Paroxysmal (2-4 weeks)
- Convalescent (3-4 weeks)
What symptoms are seen in each stage ofB. pertussis?
- Incubation - none
- Cararrhal - rhinorrhea, malaise, fever, sneezing anorexia
- Paroxysmal - repetitive cough with whoops, vomiting, leukocytosis
- Convalescent - diminished paroxysmal couch, development of secondary complications
When will bacteria be present in culture of B. pertussis?
Highest in catarrhal, increases during end of incubation and decreases during paroxysmal
What is the treatment for B. pertussis and when is it effective?
Macrolide; only in the catarrhal stage
How can B. pertussis be prevented?
- Acellular vaccines
- DTaP (all infants receive)
- Tdap (adults receive in place of one Td booster given every 10 years)
