Microbiology Ch. 18: Neisseria Species and Moraxella catarrhalis

What are some general characteristics of Neisseria?

Aerobic, nonmotile, gram-negative diplococci

Is Neisseria catalase positive or negative?

positive

Is Neisseria oxidase positive or negative?

positive

Is Neisseria capnophilic?

yes

What are the primary human pathogens of Neisseria?

N. gonorrhoeae and N. meningitidis

Who is the natural host of N. gonorrhoeae?

Humans

What is the most reported bacterial STD in the United States?

Gonorrhea

Where in the body do G. gonorrhoeae infections occur?

Urethra, endocervix, anal canal, pharynx, and conjunctiva

How many colony types are associated with N. gonorrhoeae? What are they based on?

5 types (T1-T5) based on presence or absence of pili

What makes prevents phagocytosis of N. gonorrhoeae?

Capsule, cell wall proteins, and lipopolysaccharides

What percent of males who have gonorrhea are asymptomatic?

3-5%

What percent of females who have gonorrhea are asymptomatic?

Up to 50%

If left untreated, what can gonorrhea cause in the female?

Pelvic inflammatory disease, sterility, ectopic pregnancy, or Fitz-Hugh-Curtis syndrome

What strains of gonorrhea are often isolated from asymptomatic males?

AHU strains (arginine, hypoxanthine, and uracil)

If a newborn is exposed to gonorrhea at birth, what can they acquire?

Ophthalmia neonatorum, which can result in blindness without treatment

How would you collect and transport N. gonorrhoeae?

Specimen of choice is urethra in males and endocervix in females, it's extremely sensitive to the environment so use transport system (JEMBEC) if available

Should direct gram stains of N. gonorrhoeae be performed?

Yes

What would you grow N. gonorrhoeae on?

CAP, poorly on BAP, USE MTM agar

Why would you use warmed media when plating N. gonorrhoeae?

Because it's very temperature sensitive

How would you incubate N. gonorrhoeae?

Incubate at 35'C in a 3-5% COs atmosphere

If using the candle jar method to incubate N. gonorrhoeae, what type of candle must be used?

Only white wax candles

How does N. gonorrhoeae appear under the microscope?

Gram-negative, kidney-bean shaped diplococci

How often should you examine plates when N. gonorrhoeae is suspected?

Daily

How long should you hold plates when N. gonorrhoeae is suspected?

72 hours

What result would you expect when you test N. gonorrhoeae with the Cysteine Trypticase agar carbohydrate panel?

Glucose positive ONLY

Do all N. gonorrhoeae isolates need to be tested for beta-lactamase production?

Yes

What is the drug of choice for N. gonorrhoeae? If there is resistance than what should you use?

Penicillin
rocephin is best alternative

What diseases are associated with N. meningitidis?

Endemic and epidemic meningitis, meningococcemia, pneumonia, purulent arthritis, and endophthalmitis

What N. meningitidis serotype is most associated with pandemics?

Group A

What N. meningitidis serotypes are most common in the US?

Groups B and C

What N. meningitidis serotype is the primary cause of meningococcal pneumonia?

Group Y

What N. meningitidis serotype is most often responsible for invasive disease?

Group W135

Which organism is known for causing meningitis outbreaks in populations with close contact, such as military barracks and college dorms?

N. meningitidis

What are some clinical infections associated with N. meningitidis?

Sepsis, petechial skin lesions, disseminated intravascular coagulation, septic shock, and Waterhouse-Friderichsen Syndrome

N. meningitidis grows on:
-CAP ONLY
-BAP ONLY
- Both CAP and BAP

Both CAP and BAP

Is N. meningitidis Catalase and oxidase positive or negative?

Positive

What will the results be on a carbohydrate test when testing N. meningitidis?

Glucose and Maltose positive

What is the drug of choice when treating N. meningitidis?

Penicillin

What organism is an opportunistic pathogen isolated only from humans and is associated with pneumonia, sinusitis, otitis media, and systemic disease?

Moraxella catarrhalis

What organism produces smooth, opaque colonies that are gray to white in color and are referred to as "Hockey pucks" or "Wagon wheels"?

Moraxella catarrhalis

Is M. catarrhalis sacchrolytic or asacchrolytic?

asacchrolytic

What nonpathogenic organism can often be misidentified as N. gonorrhoeae?

N. cinerea

What nonpathogenic organism looks a lot like N. meningitidis, and is the only Neisseria species that ferments lactose?

N. lactamica

What nonpathogenic organism has "dry, wrinkled, breadcrumb-like colonies?

N. sicca

Carbohydrate reaction for N. gonorrhoeae:

Glucose only

Carbohydrate reaction for N. meningitidis:

Glucose and Maltose

Carbohydrate reaction for N. lactamica:

Glucose, maltose, and lactose

Carbohydrate reaction for N. sicca:

Glucose, maltose, and sucrose

Carbohydrate reaction for N. catarrhalis:

All negative