Aerobic Gram Negative Cocci Flashcards by Olivia Briley

Does Neisseria sp. require enriched media? If so, what are some examples?

Yes, CHOC and gonococcal selective media. Important: also requires increased CO2

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Oxidase pos
Catalase pos
What type of bacteria is this?

Neisseria sp.

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How can the ID of Neisseria sp. be aided?

With the ability to utilize carbs (sugars) in CTA agar

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Is Neisseria gonorrhoeae normal flora of mucous membranes?

No, this is the only one that isn’t normal flora in this type of bacteria.

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What are the 2 pathogenic species in Neisseria sp.?

N. gonorrhoeae and N. meningitidis

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What bacteria originally thought to be the causative agent of syphilis? (“The clap”)

Neisseria gonorrhoeae

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What type of bacteria is referred to as gonococci? Is humans the only natural host for this kind of bacteria?

Neisseria gonorrheae; yes

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What does Neisseria gonorrhoeae primarily affect in the body?

Urethra, endocervix, anal canal, pharynx, conjuntiva

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Name this bacteria:
Transmitted most commonly by sex
Nationally reportable disease
Many carriers are asymptomatic
Highest rates in southeastern US

Neisseria gonorrhoeae

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What is the incubation period for Neisseria gonorrhoeae?

2-7 days

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Neisseria gonorrhoeae infection in males causes:

Acute urethritis: purulent discharge and dysuria (urethral exudate smears - sensitive and specific - presumptive ID
Most infections are symptomatic 95%
Infections of prostate and epididymis

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Neisseria gonorrhoeae infections in females causes:

Up to 50% causes asymptomatic
Gram stain less reliable as presumptive ID
Endocervix is most common site of infection
Vaginal discharge, dysuria, lower abdominal pain

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What does untreated infections of Neisseria gonorrhoeae in females cause?

May lead to Pelvis Inflammatory Disease (PID), which leads to infertility or ectopic pregnancy

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What are 4 disseminated infections in N. gonorrhoeae?

Septicemia: typically not recovers in commonly utilized blood culture due to inhibition by anticoagulant

Infections of synovial fluid: bacteria hangs out in joints causing pain and swelling

Fever
Rash

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Are eye infections possible with N. gonorrhoeae?

Yes, If they are in contact with infected genital secretions

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What is a gonococcal eye infection that newborns squire through vaginal delivery from infected mother? It can often result in blindness if not treated immediately

Ophthalmia Neonatorum

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What is Neisseria meningitidis referred to as?

Menigococci

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Is Neisseria meningitidis normal flora?

Yes, found in naso and oropharynx of many adults

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What does Neisseria meningitidis cause?

Meningitis
Meningococcemia
Pneumonia
Purulent arthritis
Endophthalmitis

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How many serogroups does Neisseria meningitidis have?

13; meningitis outbreaks of college students

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Epidemic meningitis sources caused by N. meningitidis are often from:

Asymptomatic carriers, oral secretions, respiratory droplets, groups with close contact

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Symptoms of meningitis from N. meningitidis

Quick onset of frontal headache, stiff neck, fever (sometimes)

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What is Meningococccemia?

Sepsis with N. meningitidis

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What is the mortality rate of Meningococcemia, even if treated?

25%

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Symptoms of Meningococcemia:

Purpura (hemorrhaging into skin/mucous membranes) Petechial rash (pinpoint red rash) Tachycardia Hypotension

Is Meningococcemia a slow spreader, or does it rapidly spread?

Spreads rapidly

What could Meningococcemia lead to?

Disseminated Intravascular Coagulation (DIC) Septic shock Waterhouse-Friderichsen syndrome (hemorrhage in adrenal glands)

Oxidase pos Catalase pos Indoxyl acetate pos Produces B-lactamase (resistant to penicillins)

Moraxella catarrhalis

What media can Moraxella catarrhalis grow on?

SBA and CHOC

This type of bacteria has colones that are often referred to as “hockey pucks” or “scooter” as they glide across the surface of the media

Moraxella catarrhalis

What type of media does Moraxella catarrhalis not grow on?

Gonococcal selective media

Infections associated with Moraxella catarrhalis:

Common flora of upper respiratory tract Opportunistic pathogen Upper respiratory tract infections Otitis media Sinusitis

Why should you avoid disinfectants when collecting Neisseria spp.?

Organisms susceptible to some agents

What types of swabs should be used to collect Neisseria spp.?

Dacron or Rayon swabs, NOT cotton or calcium alginate!

Should you wait to inoculate agar with Neisseria spp., or inoculate it immediately?

Inoculate immediately or use transport medium

Should you refrigerate Neisseria spp.?

No! Do not refigerate

What types of medias are used for Neisseria sp.?

CHOC Martin Lewis Modified Thayer Martin (MTM) Thayer Martin (TM) Jembec System (MTM with CO2 generator)

What type of atmosphere does Neisseria sp. needs to be grown in?

3 - 5% CO2 (can use incubator or candle jar)

How to prepare a candle jar:

Media in jar, light candle, close lid, place jar in 35 C incubator

Will N. gonorrhoeae grow on SBA?

No, only grows on CHOC and selective media

What does N. gonorrhoeae colones look like?

Small grayish white (tan?), appear 24-48 hrs

What types of medias does N. meningitidis grow on?

SBA CHOC Selective agars

What does N. meningitidis colonies look like?

Typically wet, grey colonies; others may be pigmented

What medias will Saprophytic Neisseria sp. grow on?

SBA and CHOC Typically do not grow on selective media

What does Saprophytic Neisseria sp. colonies look like?

May be pigmented (yellow), dry, mucoid, adherent, or white

What types of medias does Moraxella catarrhalis grow on?

SBA and CHOC at 35-37 C and increased CO2 Also grows in 24-48 hrs

What does Moraxella catarrhalis colonies look like?

“Scooter” or “hockey puck” - colonies slide across agar when pushed

What percent Catalase is positive for all aerobic gram negative cocci?

3% Catalase

What percent Catalase shows vigorous bubbling with N. gonorrhoeae and weak bubbling or no reaction with other species?

30% Catalase

What does oxidase testing detects?

Detects presence of cytochrome c oxidase

What is the reagent used for the Oxidase rapid method?

1% tetramethly-p-phenlyenediamine

What color is a pos reaction for a Oxidase test?

Blue

What does Cystine Trypticase agar (CTA) contain?

Contains 1% of each carb to be tested: glucose, sucrose, maltose, lactose

CTA agar reaction with yellow color change with phenol red indicator means

This means that there was a utilization of carbohydrate(s)

How to inoculate CTA agar:

2-3 isolated colonies, insert loop into top 1/4 of media and wiggle to remove bacteria Keep cap tight Incubate 35C in Non-CO2 for 24-48 hrs Keep 48 hrs before discarding and calling negative

Positive versus negative reaction in CTA agar

Yellow = pos CTA stays red = neg

What is the Microbial ID System called to test lots of reactions at one time?

API NH

Look back in notes on Chart starred and Flowchart

What is used for rapid ID of M. catarrhalis?

CLSI M35-A For gram neg diplococci that are oxidase positive and grow on both SBA and CHOC, a positive rapid butyrate esterase or tributyrin test identifies M. catarrhalis. Limitation: most other Moraxella species are pos for this test, but are coccobacilli, not diplococci Green = positive

How can GC or N. gonorrhoeae be rapidly detected?

By molecular assays - typically detects GC and chlamydia trachomatis simultaneously

Can rapid ID be used to ID N. gonorrhoae in child sexual abuse cases?

No, cannot be used in cases involving boyd and recital and oropharyngeal infections in prepubescent girls and when evaluating a potential gonorrhea treatment failure

Is susceptibility testing routinely preformed on aerobic GNC?

For the Cefinase method: Neisseria spp. are ____ For the Cefinase method: M. catarrhalis is typically ____

Variable; positive

A patient is seen complaining on pain in her knees and a recent history of a rash on her legs. A synovial fluid was sent to the lab for gram stain and culture. The specimen was reported as: * Many WBCs * Rare intracellular Gram neg diplococci The synovial fluid was cultured to SBA, CHOC, and MAC. After 24 hrs incubation at 37C in CO2, small tan colonies are seen on CHOC; SBA and MAC are NG. What does this information tell you about the organism? Would you perhaps consider this significant growth or perhaps media contamination? What types of testing might you perform on the colonies to determine ID? What organisms would you suspect?

Fastidious organism Significant growth Oxidase, Catalase, Sugar test Gonorrhea

Name all bacterias that are Aerobic Gram Negative Cocci

Neisseria sp. -Neisseria gonorrhoeae (GC) -Neisseria meningitidis -Saprophytic Neisseria sp. Moraxella catarrhalis

Most Neisseria species are: a. oxidase positive, gram positive diplococci b. oxidase positive, gram negative diplococci c. oxidase negative, gram negative diplococci d. oxidase negative, gram positive diplococci

b. oxidase positive, gram negative diplococci

Asymptomatic gonococcal infections in women may result in: a. pelvic inflammatory disease b. ectopic pregnancy c. Fitz-Hugh-Curtis syndrome d. All of the above

d. All of the above

What is the optimal specimen to collect for the diagnosis of gonorrhea by culture in male patients? a. pharyngeal swab b. rectal swab c. urethral swab d. urine

c. urethral swab

Direct gram stain for the diagnosis of gonorrhea: a. Is appropriate on vaginal specimens b. Can accurately detect urethritis in males c. Can accurately diagnosis gonococcal pharyngitis d. All of the above

b. Can accurately detect urethritis in males

Identify a selective medium that allows the isolation of N. gonorrhoeae and N. meningitidis. a. SBA b. CHOC agar c. Modified Thayer-Martin d. All of the above

c. Modified Thayer-Martin

Identify the test that can be used for definitive identification of both N. gonorrhoeae and N. meningitidis. a. gram stain b. catalase c. oxidase d. carbohydrate utilization

d. carbohydrate utilization

A limitation of nucleic acid amplification tests for diagnosing gonorrhea is that the tests: a. are rapid and sensitive b. require viable organisms in the specimen c. are not approved for use in children d. require strict transport conditions

c. are not approved for use in children

Moraxella catarhalis is not often associated with: a. Meningitis b. Septicemia c. Endocarditis d. Lower respiratory tract infections

d. Lower respiratory tract infections

Entrance of N. meningitidis into the bloodstream may lead to: a. meningococcemia b. meningitis c. Waterhouse-Friderichsen syndrome d. All of the above

d. All of the above

Which organism is an opportunistic pathogen associated with otitis media and sinusitis in children? a. N. lactimica b. N. meningitidis c. N. sicca d. M. catarrhalis

d. M. catarrhalis

Describe the colony morphology of M. catarrhalis, and explain how it is identified in the lab.

-grows on SBA and CHOC agar -smooth, opaque, gray-white colonies -"hockey puck" colony because it remains intact when pushed across the plate with a loop -older colonies may have a wagon wheel appearance -oxidase and catalase positive -asaccharolytic -differentiated from Neisseria by positive DNase or butyrate esterase reactions

Erythromycin eye drops are placed in the eyes of newborns to prevent infections caused by: a. N. meningitis b. N. gonorrhea c. N. cinerea d. M. catarrhalis

b. N. gonorrhea

Aerobic Gram Negative Cocci Flashcards

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