Non-spore forming Flashcards
It is the most significant member of the causative agent of diphtheria
Corynebacterium diphtheriae
What is other name for corynebacterium diphtheriae?
Klebs-Loffler bacillus or diphtheria bacillus
What is the virulence factor for C. diphtheriae?
Diphtheria toxin
Slightly curved gram positive rods with unparallel sides and slightly wider ends, producing “club shape”
C. diphtheriae
The organism is carried in the upper respiratory tract and spread by droplet infection or hand to mouth contact
Respiratory diphtheria
What is the most common site of infection for respiratory diphtheria?
Tonsils or pharynx
Begins with low grade fever, malaise, and mild sore throat
Respiratory diphtheria
It may result if the membrane blocks the air passage
Suffocation
Cutaneous diphtheria also known as
Veldt sore or Barcoo rot
Consist of nonhealing ulcers with a dirty gray membrane
Cutaneous diphtheria
What is the antibiotic of choice for diphtheria?
Penicillin
What is given for penicillin-sensitive individuals?
Erythromycin
What are the two formations corynebacterium diphtheriae made?
V or L formations and
Beaded appearance
Which medium does C. diphtheriae appears black or brownish colonies from the reduction of tellurite?
CTBA - Cystine tellurite blood agar
Chinese characters appearance on stained smear
C. diphtheriae
C. diphtheriae produced a brown halo in which agar?
CTBA
Immunodiffusion test in which organisms are streaked on a medium of low iron content
Elek test
Late onset neonatal listeriosis is typically persent as
Meningitis
A nugent score of 2 indicates
Normal vaginal biota
A positive elek test is indicated by
Arch of precipitin lines
Club-shaped
Corynebacterium
What is the causative agent of diphtheria?
Corynebacterium diphtheriae
Areas that stain more intensely than other parts of the cell
Babes-Ernst granules
When the corynebacterium stains irregularly, it gives what appearance?
Beaded appearance
What is the oxygen requirement for Corynebacterium?
Facultative anaerobe
What is the culture media of choice for C. diphtheriae?
Loeffler’s serum or Pai agars
Which species produce a brown halo on CTBA?
C. diphtheriae, C. ulcerans, C. pseudotuberculosis
Used to differentiate C. diphtheriae from C. ulcerans and C. pseudotuberculosis
Urease test
C. diphtheriae lack of urease production
Most frequently recovered corynebacterium spp from human clinical material.
Corynebacterium amycolatum
Prosthetic valve endocarditis, septicemia, meningitis, and skin complications
Corynebacterium jeikeium
Most frequently associated with respiratory tract infections in immunocomromised individuals.
Corynebacterium pseudodiphtheticum
Associated with prosthetic joint infection, bloodstream infection and endocarditis in immunosuppressed patients
Corynebacterium amycolatum
Associated with endocarditis, UTI, and cutaneous wound infection
Corynebacterium pseudodiphtheticum
Veterinary pathogen. May cause granulomatous lymphadenitis in humans
Corynebacterium pseudotuberculosis
Skin ulcerrs and exudative pharyngitis
Corynebacterium ulcerans
Associated with cases of endocarditis, septic arthritis, meningitis, and pneumonia
Corynebacterium striatum
Associated with UTIs
Corynebacterium urealyticum
Only human pathogen of the genus listeria
Listeria monocytogenes
It is uncommon but serious infection of neonates, pregnant women, elderly and immunocompromised host
Listeriosis
It is widespread in the environment: soil, water, vegetation. Can be found in animal products such as milk, cheese, poulty, and processed meats
Listeria monocytogenes
What are the virulence factor of listeria monocytogenes?
- listeriolysin O (hemolysin)
- catalase
- superoxide dismutase
- phospholipase C
- surface protein (p60)
Induces phagocytosis through increased adhesion and penetration into mammalian cells
Protein p60
Damages the phagosome membrane, preventing killing of the microorganisms by the macrophage
Listeriolysin O
What is the mode of entry in listeria monocytogenes?
Ingestion of contaminated food
What disease listeria can cause to pregnant women?
- may cause spontaneous abortion and stillborn neonates
- may result to premature labor and septic abortion with 3-7 days
Intrauterine infection that can cause illness at or shortly after birth (SEPSIS)
Early onset
Occurs several days to weeks afterbirth (MENINGITIS)
Late onset
What is the colony morphology of listeria?
Gram positive coccobacillus in singly, chains or in palisades
May be used to isolate this organisms from clinical specimen. The specimen is inoculated in broth and incubation at 4 degrees for several weeks. Subcultures are made at weekly intervals.
Cold enrichment
What is the specimen for listeria?
Blood, csf, swabs from lesion
It exhibits tumbling motility when viewed microscopically.
In motility medium, the characteristic “UMBRELLA” patrern is seen when the organism is incunated
Listeria
Produces a block type of hemolysis in CAMP test
Listeria monocytogenes
What are the biochemical tests that tested positive for listeria?
+ for hippurate test
+ for bile esculin hydrolysis
+ for CAMP test
What organism is used in place of S. aureus in CAMP test?
Rhodococcus equi
Human infection are due to occupational exposure, especially those who handles fish and animal products
Erysipelothrix rhusiopathiae
Localized skin lesion that resembles streptococcal erysipelas, usually seen on the hands and fingers
Erysipeloid
Low grade fever, arthralgia, and lymphadenopathy may occur
Erysipeloid
Uncommon and rarely develips from erysipeloid
Systemic infection
Has been seen in patients who have had valve replacrment as well as those with apparently normal heart valves
Endocarditis
How many percent is the mortality rate of endocarditis by E. rhusiopathiae
38%
What is the antibiotic of choice for cutaneous and systemic infection?
Penicillin
What is the specimen for culture cor Erysipelothrix rhusiopathiae?
Tissue biopsy or aspirates from skin lesions
What is the hemolysis of E. rhusiopathiae?
Nonhemolytic
It has test tube brus like pattern in gelatin stab incubated at 22 degrees
Erysipelothrix rhusiopathiae
It is short, pleomorphic gram positive tod or coccobacillus that often stains gram variable or gram negative
It has gram positive type of cell wall
Gardnerella vaginalis
Primarily known for bacterial vaginodis in humans
Gardnerella vaginodid
What is the drug of choice for gardnerella?
Metronidazole and clindamycin
Clue cells
Gardnerella vaginalis
A nugent score of 7-10 indicates
Bacterial vaginosis
A nugent score of 4-6 indicates
Intermediate for BV
What is the specimen for Gardnerella vaginalis?
Vaginal discharge
Can be isolated from urine
The G. vaginais growd best at
5-7% carbon dioxide at 35-37 degrees
What is the medium of choice for G. vaginalis?
HBT or Human Blood bilayer tween agar
When cultured in Sheep blood agar appears
When cultured on human blood
- Pinpoint, nonhemolytic colonies
- small, gray, opaque, beta-hemolytic
Beta/hemolytic colonies on HBT agar should be suspected as
Gardnerella vaginalis
Aerobic, branched, finely beaded gram positive bacilli
Nocardia
What is the virulence factor of nocardia?
- superoxide dismutase
- catalase
Pulmonary infections is caused by
Nocardia cyriacigeorgica and Nocardia farcinica
Occurs from the inhalation of the organism present in dust or soil
Pulmonary infections
What is the most common manifestation of pulmonary infections?
Confluent bronchopenumonia usually chronic but may be acute or relapsing
Occurs after inoculation of the organisms into the skin or subcutaneous tissue
Cutaneous infection
Most frequent cause of this cutaneous infection of nocardiosis
Nocardia brasiliensis
The lesion of cutaneous infection is called
Actinomycotic mycetoma
Lesion of cutaneous infection often seen in
Hands and feet
Characterized by swelling, draining sinuses, and granules
Mycetomas
Beaded branching filaments are seen in sputum and exudates pr aspirates from skin or abscesses
Nocardia
Chalky, matte, velvetty, or powdery appearance and may be white, yrllow, pink, orange, peach, tan, or gray.
Nocardia
Dry, crumbly apearace similar to breadcrumbs
Nocardia
Medium used for nocardia
MTM - modified thayer martin agar
Buffered charcoal-yeast extract agar
Colonies dissecting microscope may reveal the presence of
Aerial hyphae
What is the most reliable method for identification of nocardia?
16S rRNA gene sequencing
Chronic granulomatous disease characterized by the development of sinus tracts that erupt to the surface and drain pus that may contain sulfur granules
Actinomyces
Actinomyces causes
Lumpy jaw
In what region can you see actinomycosis
Maxillary region and female genital tract
Has a colonies with molar tooth apoearance
Actinomyces
Aerotolerant anaerobes
Lactobacillus
They play an important role in the health of the female vaginal tract in that they help to protect host ftom genital infections
Lactobacillus
