Home Page Flashcards Guess this bug - Flashcards

Guess this bug – Flashcards

Mya Day

7 July 2022

Unlock all answers in this set

Unlock answers

question

1 yo or 20yo
-respiratory spread
-complement deficiency, asplenia, hepatic disease, multiple myeloma are possible underlying conditions
-acute onset of fever, chills, arthralgias, myalgias
-rapid petechial rash/purpura fuminans
WHAT is it? What would you culture?

answer

Neisseria meningitidis
CSF

question

Other possible infections of N. meningitidis

answer

pneumonia in pre-existing lung disease
fulminant bacteremic supraglottitis-swollen tongue
meningococcal conjunctivitis
complications resulting from hematogenous dissemination-osteomyelitis, pericarditis

question

Prophylaxis against meningococcal disease
who and what?

answer

college freshman living in dormitories
microbiologists
military recruits
travelers to the belt
people w/ complement component deficiencies, asplenia
rifampin, ceftriaxone, azithromycin NOT fluoroquinolone
VACCINE
tetravalent polysaccharide capsule vaccine->T-cell indepedent antigens
conjugate vaccine->Tcell dependent immune response in infants

question

Limitations of the Meningococcal Vaccine

answer

capsular vaccine is only temporary immunity
Group B antigen is poorly immunogenic b/c it is like NA in human CNS
Outer membrane proteins are immunogenic but too specific to create a vaccine

question

Culturing Neisseria

answer

MTM-specialized chocolate-agar based
G: endocervix, urethra discharge
-rectum, urethra, pharynx, blood, skin lesions
M: CSF, blood, skin lesions, nasopharyngeal swabs, biopsies, rectal
[image]

-colonies are mucoid wet appearing b/c encapsulated

question

[image]
Oxidase test with cytochrome c

answer

Neisseria is oxidase +
catalase variable

question

What tests are unique to N. gonorrhoeae?

answer

fluorescent Ab tests-not sensitive
coagglutination and other immunologic tests
Nucleic acid amplification tests-current
use genital swabs or urine sample
ferments glucose only

question

Treatment for Neisserias

answer

Gonorrhea-ceftriaxone or 3G cephalosporins
follow up treatment w/ azithromycin or doxycyclin for chlamydia
NO fluoroquinolones
Meninitidis-penicillin and 3G cephalosporins

question

-small, fastidious, pale staining gram - bacilli
[image]
-Do not grow on sheep blood agar but grow on chocolate agar
-meningitis, otitis media, sinusitis, epiglottitis, tracheobronchitis, bacteremia, pneumonia
-satellite test for ID

answer

Haemophilus influenza
requires X factor=hemin and V factor=NAD

question

How do you identify Haemophilus species?
Treatment for H. influenzae

answer

1. hemolysis on horse blood agar
2. satellite test
3. determination of X and V requirements on TSA
4. carbohydrate utilization tests

Ampicillin or 3G ceph-parenteral
Amoxicillin

question

[image]
satellite test

answer

S. aureus lyses rbc's-;X factor
S. aureus secretes V factor
on sheep agar
-Haemophilus species needs both V and X factor

question

[image]
horse blood agar has no hemolysis
;
;
What is the haemophilus species?

answer

H. influenzae requires both X and V factors and does not hemolyze horse blood agar

question

Haemophilus species that requires only factor V (NAD) and ;does not hemolyze horse blood agar

answer

haemophilus parainfluenze

question

Haemophilus species that B-hemolyzes horse blood agar and requires X and V factors

answer

H. haemolyticus

question

Haemophilus species that B-hemolyzes horse blood agar and requires factor V only

answer

H. parahaemolyticus

question

-Papular lesion that becomes ulcerated w/ ragged, non-indurated and painful
-gray-yellow exudate w/ easy bleeding
-may have supperative inguinal lymphadenopathy
[image][image]
gram- with chain arrangement or school of fish arrangement

answer

Haemophilus ducreyi with a chancroid
-inguinal buboes may need to be drained to prevent rupture and sinus formation

question

Isolating and IDing;H. ducreyi

biochemistry-oxidase, catalase, carb, factor requirement, nitrate reductase, alkaline phosphatase

answer

difficult to culture-chocolate agar w/ vancomycin to inhibit gram +
-incubate at 33C for 7-10 days
-high humidity and lower oxygen tension (candle jar)
;
pale gram - coccobacilli in railroad track or school of fish arrangement
;
Oxidase + (like Neisseria)
Catalase -
asaccharolytic
requires X factor
nitrate reductase +
alkaline phosphatase +

question

Aggregatibacter aphrophilus
Aggregatibacter actinomycetemcomitans
Cardiobacterium hominis
Eikenella corrodens
Kingella species
;
What do they have in common?

answer

Fastidious Gram Negative Bacteria
AACEK Group
Normal flora of the human upper respiratory tract
slow growing
capnophilic
hemin enhances initial recovery
grow only on enriched media-chocolate or blood
No growth on MacConkey/EMB agar
Fermentative-except Eikenella corrodens

question

Infections associated with AACEK group

answer

AACEK are normal flora of the upper respiratory tract
Bacteremia and endocarditis
Head and neck infections
Dental infections
Pleuropulmonary infections
Soft tissue infections
cellulitis, fasciitis, "clenched fist" injuries
Bone and joint infections
CNS infections

question

Primary agent in Periodontal disease in adolescents and adults
AACEK
oxidase -
catalase +
non B-hemolytic
IND -
Nitrate reduction +

answer

Aggregatibacterium actinomycetemcomitans

question

AACEK
slow growing and only on blood cultures
found in gingival sulci
associated w/endocarditis
native valves
prosthetic valves
pacemaker lead wires
Ox +
Cat -
non B-hemolytic
IND +
Fermenter
NIT -;
;
;
;
;
;
;

answer

Cardiobacterium hominis

gram stain from blood culture
Rosette and Clustered cell arrangements

question

Blood agar has "pitting" colonies
oxidase +
catalase -
smells like bleech
asaccrolytic
AACEK
Ocular infections
Head/neck infections
Pleuropulmonary infections
Intra-abdominal infections
Endocarditis-Dental work or IV drug users
Cellulitis and osteomyelitis

answer

Eikenella corrodens

question

Highest in 6mo-4 years
Day-care common for transmission
Osteoarticular infection in children ;3 yo
Bacteremia, osteomyelitis, septic arthritis
B-hemolytic
NIT RED -
;

answer

Kingella kingae

-children often have underlying disease
Congenital heart disease, ALL

question

fastidious gram - nonmotile coccobacillus
biochemically inert
Grows on Bordet-Gengou and Regan-Lowe media
No growth on chocolate, blood, or enteric media
"stoccato cough," cyanosis, vomiting
pediatric population are more symptomatic
PCR is done for?

answer

Bordetella pertussis;in the paroxysmal stage
7-14 after infection b/c cough appears after prodromal/infectious stage
complications: otitis, encephalopathy, hernia, rectal prolapse, secondary infections
Convalescent stage should occur w/in 4 weeks of onset

question

Virulence factors of Bordetella pertussis

answer

adenylate cyclase hemolysin-inhibits PMN chemotaxis and phagocytosis
tracheal cytotoxin-damages epithelial cells and inhibits DNA synthesis
heat-labile toxin
lipopolysaccharide
pertussis toxin-lymphocytosis that stimulates immune response
filmanetous hemagglutinin
pertactin-adherence and cytokine release
fimbriae-adherence

question

"staccato cough"
small gram - coccobacillus
cat +
ox -
Urease + after 24 hrs
grows on Bordet-gengou, Regan-Lowe, and chocolate agar
;

answer

Bordetella parapertussis

question

dog owner w/ dog recently in kennel
IC patient has sepsis, meningitis, peritonitis, pneumonia
Ox +/Cat +
gram - motile;bacillus
grows on BG, RL, chocolate, and MacConkey
asaccharolytic
urease + in 4 hours

answer

Bordetella bronchiseptica

question

Fastidious Gram - Bacteria

answer

AACEK
Bordetella
Pasteurella
Brucella
Bartonella

question

nonmotile gram - bacilli
facultative anaerobes
OX +/CAT +
NIT RED +
Fermentative
-think animals!

answer

Pasteurella;spp.
;
P. canis
P. dagmatis-dog bites
P. caballi-horse bites
P. gallinarum-chickens and sepsis, endocarditis in humans
P. bettyae-human GU tract, post-partum bacteremia, salpingitis, PID

question

facultative, non-motile gram - bacilli
grows on blood and chocolate but not MacConkey agar
Ox +/Cat +
IND +
penicillin-susceptible
bite and scartch from a cat

answer

Pasteurella multocida

may colonize the resp tract of vets
mostly wound infection/cellulitis
may be more severe and deep in IC (diabetics)
resp tract infections: pneumonia, empyema, lung abscess
bacteremia/endocarditis
CNS infection-brain abscess
Eye infections

question

Pathogen species that humans acquire mostly from animals and animal products (esp. sheep and goats)

answer

Brucella spp.

question

Principal reservoir in goats
acquired by eating infected unpasteurized milk and cheese
Endemic to Arabia, LA, Peru, Mexico, Argentina, Spain, Italy, Greece
2-3 weeks after exposure-;symptoms
fever, night sweats, chills, malaise
lymphadenopathy, hepatosplenomegaly
undulating fevers for weeks-months
grows on blood and chocolate agar but not MacConkey agar
small gram - non-hemolytic coccobacilli
Ox +/Cat +
asaccharolytic

answer

Brucella melitensis
Brucellosis is a chronic disease that has a long treatment period to act on phagocytic cells

question

Best specimens for Brucella?
Ways to ID different species?

answer

Blood and bone marrow
-organism is sequestered in granulomas in tissue and bone marrow (RES)
Complications can occur on every system!
;
-Species identification can be done by
1. urease production
2. susceptibility to aniline dyes
3. direct fluorescent antibodies to individual species

question

Ulceroglandular _
Glandular _
Oculoglandular _
Pharyngeal _
Typhoidal _
Penumonic _

answer

;
Tularemia
-transmitted Amblyomma americanum;tick or direct inhalation

question

Patient has general symptoms of chills, fever, malaise, anorexia, fatigue. Cough, chest and abd pain, vomiting, sore throat, and diarrhea.
Tick bite
Sputum is non-diagnostic
Chest Xray shows widened mediastinum.
TBlike granulomas on pleural biopsies
;

answer

Pneumonic Tularemia
Francisella tularensis

question

Culturing Francisella tularensis

answer

Blood, pleural fluids, lymph nodes, wounds, conjunctival swabs, tissue, respiratory tract secretions (NOT cough sputum)
Culture on blood/chocolate agar and incubate for 3-4 weeks, but often falsely negative
very small, non-motile, obligately aerobic, gram - coccobacilli
ox -/cat +
organism is dangerous for laboratory personnel
ID w/ agglutination, DFA, or PCR

question

Small, slightly curved fastidious, aerobic gram - bacilli
very slow growing requires freshly prepared blood or chocolate agar media incubated in CO2
growth in 25-37C
reservoir in wide variety of animals
Specimens-BA lesions, lymph node biopsies ; aspirates; blood cultures w/ blind staining of media w/ acridine orange

answer

Bartonella

question

outbreaks, poor sanitation, poor hygiene=globally endemic
no known vertebrate reservoir except man
vector is human body louse
cycling fevers
small, slightly curved, very fastidious, aerobic gram - bacilli
headache, eye pain, conjunctival injection, myalgias, arthralgias, hepatosplenomegaly and leukocytosis

answer

Bartonella quintana
Trench fever

question

Homeless alocholic man with fever, bacteremia, endocarditis
IV drug user
Pre-existing valvular damage
Immunosuppressed patients have Bacillary Angiomatosis
red papule w/ scaly "collarette" that enlarge to form violacious dome-shaped nodular lesions
lesions may ulcerate and bleed
Warthin-Starry silver stain
2;Bartonella?

answer

Bartonella quintana;and;B. henselae
Urban Trench Fever

question

papule that becomes pustular a week after a scratch
fever/malaise
regional lymphadenopathy in axillary, cervical, and submandibular areas
Parinaud's Oculoglandular syndrome: Granulomatous Conjunctivitis
CSD Neuroretinitis: Papilledema Associated with Stellate Macular Exudates
Disease and Agent?

answer

Bartonella henselae and Bartonella clarridgeiae
Cat scratch disease

question

Adherent, white, "cauliflower like" colonies
small slightly curved, pleomorphic gram - bacilli
Ox -/Cat - except B. henselae is catalase variable
biochemically inert otherwise
asaccralytic
very fastidious
detection w/ antibodies

answer

Bartonella spp.
use indirect fluorescent antibodies esp for B. henselae and B. quintana (B. Clarridgeiae soon)
cross-reactions w/ chlamydiae and Coxiella burnetii
CSD is usually self-limited

question

Aerobic/Facultatie Gram + Bacilli

answer

Listeria spp.
Erysipelothrix spp.
Lactoacillus spp.
Corynebacterium spp.
Arcanobacterium spp.
Bacillus spp.
Nocardia spp.
Rhodococcus spp.

question

Listeria spp.
Nonsporeforming, facultative, gram + bacilli
motile at room temp
-blood cultures positive in meningitis in 75% of cases
-gram stain of CSF is mostly neg
-low CSF glucose or normal
-predominance of mononuclear cells
-replication in phagosome and propelled by actin to neighboring cells
-raw milk and vegetables, fish, poultry, resh and processed meats and fish, cabbage, cole slaw, soft cheeses, shrimp
-may cause self-limited febrile enteritis w/

answer

acute, less common nuchal rigidity, move disorders (ataxia, tremors, seizeures), fluctuating mental status=meningitis
Neonatal sepsis/meningitis
Meningitis or parenchymal brain infection in patients with underlying disease of adults>50
Fever during 3trimester b/c it can cross the placenta
self-limited febrile enteritis w/ N/V/D

question

Listeria monocytogenes
non-sporeforming gram + bacilli
soft B-hemolysis/CAT+/motile at 25/ BBE+-like L. innocua except hemolysis
isolate from blood, CSF, amniotic fluid, genital tract, biopsies, tissue
CSF gram stain is often neg, glucose is low, and predominanted by mononuclear cells
blood cultures are 75% +
cold enrichment for recovery from stool, food, or environmental specimens
raw milk, vegs, meats, cabbage, soft cheeses

answer

Meningitis (neonatal, IC, adults>50)
acute onset
less common nuchal rigidity
movement disorders (ataxia, tremors, seizures)
fever in 3 trimester pregnancy
TX-amp + gen/TMP/SMX

question

Erysipelothrix rhusiopathiae
nonsporeforming gram + rods
swine infected
cat -/nonmotile/H2S +, bottle brush growth in gelatin stab culture

answer

sepsis and bacteremia
native and prosthetic valve endocarditis
tx-penicillin, cephalosporins
NOT-aminoglycosides, sulfonamides-instrinsically resistant to vancomycin

question

Lactobacillus
gram +, nonsporeforming, slender rods
glucose fermentation
CAT-/OX-/H2S-/NIT-/IND-
facultative-produce H2O2
normal flora of the vagina, GI, oropharynx and other animals; in nature

answer

facultative strains may represent non-specific defense mechanism for prevention of bacterial vaginosis and candida vaginitis
[image]
opportunistic agent
endocarditis
bacteremia in IC hosts (neutropenia, antibiotic usage, transplant, chemotherapy, invasive GI, resp tract, Gyn procedures)
pleuropulmonary infections
rare infections

question

Corneybacterium genus
mycolic acids
meso-DAP
Cat +
lipophilic variable
"club"-shaped, nonmotile

answer

question

Non-lipophilic
C. diptheriae
C. amycolatum
C. striatum
C. pseudodiphtheriticum
-grows on RBCs but not on chocolate agar
-growth on trypticase-soy agar only w/ Tween-80 drop

answer

Lipophilic
C. jeikeium
C. urealyticum
-grows on both chocolate and RBCs
-grows on trypitcase-soy agar

question

Cornyebacterium diphtheriae
non-lipophilic gram + club shaped bacteria
grey-white smooth nonhemolytic colonies on SBA
toxin associated w/ lysogenization w/ B-corynephage
AB toxin-ADP-ribosylates the EF-inhibits protein synthesis
culture of throat or cutaneous specimens grows black colonies w/ brown haloes on cystine tellurite agar
place swabs on Loeffler's coagulated serum medium-beaded appearance
NIT +/Glucosidase +/Urease -/ GLU, RIB, MAL +
Elek test for toxin detection

answer

diphtheritic "pseudomembrane" in posterior oro- and nasopharynx
cutaneous diphtheria mistaken for anthrax
both toxic and nontoxic strains associated w/ endocarditis and serious infection in IV drug users

question

C. amycolatum
lacks cell wall mycolic acids
forms dry, matte,"waxy" and "wrinkly" colonies on blood agar
isolated from wounds, blood, joint fluid, bone, and UT
NIT-/PYZ-/ALKPAL+/GLU, RIB, SUC +
same as C. striatum

answer

fatal sepsis in a premature infant

question

C. striatum
non-lipophilic/API like C. amycolatum
creamy, white, target colonies on BA

answer

found in human nares and on skin
OI-bacteremia and endocarditis
wound and conjunctival infections
colonization of prosthetic devices

question

C. pseudodiphtheriticum
NIT-/PYZ-/PYR-/PAL+
Urease+ in 24 h
asaccharlytic

answer

-resp tract infections in IC hosts
-endocarditis on valves
wound infections
;
Tx-B-lactam, vancomycin, and aminoglycosides

question

Corynebacterium jeikeium
-lipophilic
NIT-/PZY and PAL+/URE-
GLU and RIB +

answer

-colonizes the skin of hospitalized
-Infection in IC, neutropenia, indwelling medical devices
-under arm or groin area

question

C. urealyticum
lipophilic, small gray nonhemolytic colonies at 24h
-URE+ Rapidly (w/in mins)
-asaccharolytic

answer

found on skin of humans and animals
acute and chronic UTIs in elderly, IC, and animals
-urolithiasis and alkaline-ecrusted cystitis in those w/ pyelonephritis (struvite)
-osteomyelitis, bacteremia, endocarditis, soft tissue and wound infection

question

Arcanobacterium haemolyticum
lipophilic, gram+ bacillus
CAT-
small, dull colonies after 48h showing "soft" B-hemolysis

answer

pharyngitis and wound infections in children and young adults
"scarlatinaform rash"
-may be mistaken for group A strep pharyngitis

question

Bacillus;spp.
gram + (variable) rods
Endospore forming under aerobic conditions
CAT+

answer

question

Virulence factors of;B. anthracis
produces toxins of 3 proteins (PA, EF, LF)
PA-binds to target cell receptors and aggregate to form ring-shaped hexamers-;pores through the target cell membrane
EF and LT-inhibit phagocytosis, block oxidative burst of PMNs and increase intracellular cAMP levels
LT in macrophages-inhibits macromolecular synthesis, promotes apoptosis and hydrolyzes protein kinases involved in singal transduction
Capsule-resides on second plasmid-inhibtis phagocytosis
synthesis influenced by levels of CO2 and bicarbonate

answer

question

Bacillus anthracis
swabs/biopsies from supsected eschars
stool, blood, hemorrhagic fludis from nose, mouth or anus, aspirates from peritoneum, spleen, mesenteric lymph nodes, paired serum specimens
gram+ broad rod; oval central/subterminal spores
non-hemolytic, ground glass w/ "egg white" consistency and "Medusa-head" margins
Negative motility and neg hydrolysis of gelatin
India ink + (capsules)
CAT+;

answer

cutaneous anthrax-most common; spores under skin; small papules that ulcerate surrounded by vesicles; painless eschar w/ edema
GI-fever, acute gastroenteritis, vomiting, bloody diarrhea, intestinal eschar-bleeds, generalized toxemia
Inhalational-spores; 1-2days high fever, dyspnea, hemorrhagic; mediastinal widening;
NO pneumonia
tx-penicillin except inhalation

question

Bacillus cereus and other nonanthrax spp.
B-hemolytic
motile
hydrolyzes gelatin

answer

diarrheal syndrome-LT; abd pain w/ watery diarrhea after ingestion of meat, veg, cakes, suaces, dairy products
emetic syndrome-LT; N/V w/ fried rice dishes left out in a buffet

bacteremia, endocarditis
endophthalmitis
infections in IC
musculoskeletal infection
nosocomial infections

question

Nocardia
smears are only ;50% sensitive
invasive techniques for diagnosis-bronchalveolar lavage, TTA, bronchoscopy, bronchial brushings
scans may show mass lesion in the brain w/ a normal CSF
gram stain-beaded, 90degree branching
Modified AFbacilli and lysozyme resistant
Culture-blood, CSF, aspirates, sputum, and other resp tract specimens
colony is white, tan, orange, pink; dig into the agar to remove, cerebriform powdery surface and musty, earthy odor
ID w/ HPLC b/c hydrolysis tests are timeconsuming

answer

-infections in IC hosts beginning in the lung-;blood, skin, and CNS (brain abcess)
-assc w/ malignancies, chronic pul disease, collagen vascular disease, transplantation, diabetes and HIV
-SUBQ infection following traumatic implantation

question

Rhodococcus equi
clear-to-white, nonhemolytic and frequently mucoid, often turning salmon-pink to red (4-7 days)
asaccharolytic, NIT variable, URE+
blood cutures w/ be + in IC hosts

answer

-slowly progressive penumonia w/ lobar infiltrates progressing to cavitating lesions
IC infection

Guess this bug – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards