Neisseria and Moraxella

Question 2

What are characteristics of Neisseria?

Answer 2

many species isolated from humans; N. gonorrhoeae (always pathogen) and N. meningitidis (commensal) are primary human pathogens of genus

Question 3

Where is Neisseria found?

Answer 3

often in humans, in the upper respiratory tract of carriers, also a part of microbiome of mucous membranes in urogenital tracts

Question 4

What do N. gonorrhoeae and N. meningitidis have in common?

Answer 4

both gram-negative diplococci (shaped like kidney beans with flat side together); have pili that aid in attaching to human cells; refer increased CO2 for growth; optimal growth at 35-37 C in moist environment; fastidious (sensitive to drying and temp and survive poorly in environment); non-motile, and affinity for mucous membranes due to presence of pili

Question 5

What are the differences between N. gonorrhoeae and N. meningitidis?

Answer 5

N. gonorrhoeae - isolated from cervix, urethra, rectum, and pharynx; can be found in CSF, joints and skin; transmitted by sexual contact; causes local inflammation; “gonococcus” or “GC”; rarely lethal; killed rapidly in bloodstream; very fastidious, not encapsulated; humans are only reservoir

N. meningitidis - isolated from nasopharynx, CSF, blood; normal nasopharyngeal flora; transmitted by contact with respiratory secretions or airborne droplets; causes systemic infection; “meningococcus”; life threatening; multiplies rapidly in blood stream; not fastidious; capsules present; nasopharynx of humans is common reservoir

Question 6

N. meningitidis carbohydrate test

Answer 6

Glucose: +
Maltose: +
Lactose: -
Sucrose: -

Question 7

N. lactamica carbohydrate test

Answer 7

Glucose: +
Maltose: +
Lactose: +
Sucrose: -

Question 8

N. gonorrhoeae carbohydrate test

Answer 8

Glucose: +
Maltose: -
Lactose: -
Sucrose: -

Question 9

N. sicca carbohydrate test

Answer 9

Glucose: +
Maltose: +
Lactose: -
Sucrose: +

Question 10

Moraxella catarrhalis carbohydrate test

Answer 10

Glucose: -
Maltose: -
Lactose: -
Sucrose: -

Question 11

What is gonorrhea?

Answer 11

related to flow of semen; sexually transmitted disease that is an acute pyogenic infection of epithelium of mucosal surfaces; effects endocervix in women and urethra in men

Question 12

What other diseases can N. gonorrhoeae cause?

Answer 12

pharyngitis, suppurative arthritis, ophthalmitis (newborns in vaginal births), pelvic inflammatory disease (untreated cases and causes sterility and ectopic pregnancies

Question 13

How can we test for N. gonorrhoeae?

Answer 13

take specimen from infected area and immediately place into transport media or plate; urine places into transport media (NAAT); swab from infected area (as per exudate) and then test in nucleic acid amplification test (NAAT), grow in culture, or gram-stain test

Question 14

What should we be aware of when sending a culture of potential N. gonorrhoeae to the lab?

Answer 14

the organisms are very sensitive to atmosphere and temperature; specimen should be sent to lab immediately; the plate needs to be put in commercial zipper; CO2 generating system and sent to lab

Question 15

How can we identify Neisseria?

Answer 15

1) select for with MTM agar
2) oxidase positive
3) rapid tests
4) biochemicals

Question 16

Epidemiology of N. gonorrhoeae

Answer 16

occurs mostly among young people aged 15-24

Question 17

How do we treat gonorrhea?

Answer 17

ceftriaxone with azithromycin is treatment of choice; many strains are resistant to penicillin

Question 18

How does Neisseria meningitidis transmit?

Answer 18

nasopharynx of humans is the only reservoir, spread by respiratory droplets; 5-15% of teens and young adults are carriers; 90% rates in closed populations such as frat, military barracks, or within families

Question 19

What does N. meningitidis cause?

Answer 19

meningitis usually seen in children and young adults, causes a fever, headache, neck stiffness, photophobia, irritability; meningococcemia that comes with petechial rash and can lead to shock and disseminated intravascular coagulation (DIC)

Question 20

How do we test for N. meningitidis?

Answer 20

take a specimen of CSF or blood and then culture it or use molecular detection

Question 21

Epidemiology of meningitidis

Answer 21

we get <1,00 cases a year in the US; most frequent cause of meningitis in infants, children, and adolescents

Question 22

What vaccine do we have for N. meningitidis?

Answer 22

there are multiple serogroups that cause disease, the most common are B, C, Y and W135; can have vaccines for A, C, Y, W135 (quadrivalent vaccine) and B

Question 23

How do we treat N. meningitidis?

Answer 23

use 3rd generation cephalosporin, penicillin, chloramphenicol; or give rifampin to close contacts for prevention

Question 24

What are the characteristics of Moraxella catarrhalis?

Answer 24

gram-negative diplococci; normal microbiome of upper respiratory tract; is not fastidious; grows well on lab media

Question 25

What disease is caused by Moraxella catarrhalis?

Answer 25

otitis media, sinusitis; in immunocompromised and elderly we see pneumonia and bronchitis

Question 26

How do we identify Moraxella catarrhalis?

Answer 26

we take eduate from infected area and culture it; similar identification to Neisseria

Question 27

How do we treat M. catarrhalis?

Answer 27

most isolates are resistant to penicillin; susceptible to most antibiotics; decongestants are key