NON-BRANCHING, CATALASE NEGATIVE, GRAM-POSITIVE BACILLI (ERYSIPELOTHRIX, LACTOBACILLUS, AND SIMILAR ORGANISMS) Flashcards
General Characteristics sa ERYSIPELOTHRIX, LACTOBACILLUS, AND SIMILAR ORGANISMS
- Catalase-negative
- Non-spore-forming
- Gram-positive rods
- Some may exhibit rudimentary
branching
What is the only human pathogen in the Erysipelothrix genus?
E. rhusiopathiae.
-a pleomorphic, gram-positive bacillus that
-often forms long filaments,
-is catalase-negative,
-forms hydrogen sulfide,
- is non-motile but produces a characteristic “bottle brush” extension laterally from the streak line in soft gelatin agar.
E. rhusiopathiae
What is Arcanobacterium haemolyticum and where is it commonly found?
-is recovered from clinical specimens
-and is a normal inhabitant of the mucosal membranes of cattle, sheep, dogs, cats, and pigs.
Where is E. rhusiopathiae commonly found and how is it transmitted?
E. rhusiopathiae is found in vertebrate and invertebrate animals and is transmitted via direct contact or ingestion of infected water or meat.
-Previously classified as Arcanobacterium spp. -are irregular, gram-positive rods, CAMP negative
Trueperella spp
Beneficial to the human host in immunocompetent individuals
Lactobacillus spp.
What are some beneficial Lactobacillus spp. isolates for immunocompetent individuals?
-L. acidophilus,
-L. casei,
-L. fermentum,
-L. gasseri,
-L. plantarum,
-L. rhamnosus,
- L. ultunensis.
-Only specie in the genus
-has a thinner peptidoglycan layer than other gram-positive organisms, appearing as thin, gram-positive rods or coccobacilli.
Gardnerella vaginalis
are important for maintaining the proper pH balance in vaginal secretions.
Lactobacillus spp.
Lactobacillus spp. are frequently associated with?
dental caries.
Which occupations are at higher risk for Erysipelothrix infections?
-fish handlers,
-farmers,
-slaughterhouse workers,
-food preparation workers,
-and veterinarians
Erysipelothrix infections typically occur due?
to puncture wounds or skin abrasions.
What are the possible manifestations of Erysipelothrix infections?
-localized skin infections or cellulitis (erysipeloid),
-diffuse cutaneous infection with systemic infections,
- or bacteremia.
What human infection is primarily associated with Arcanobacterium haemolyticum?
pharyngitis
Trueperella bernardiae can be recovered from ?
blood, abscesses, urinary tract, joints, eyes, and wounds, and is associated with necrotizing fasciitis.
In what environments is Trueperella pyogenes typically found, and what infections does it cause?
found in rural environments and has been identified in abscesses, wounds, and blood infections
delicate, curved, gram-positive rods with pointed ends and occasional rudimentary branching.
Arcanobacterium spp
are highly pleomorphic, appearing as long chaining rods, coccobacilli, and spiral forms.
Lactobacillus spp
stains as both short rods and long filaments.
Erysipelothrix rhusiopathiae
small, pleomorphic, gram-variable or gram-negative coccobacilli and short rods.
Gardnerella
Clue cells are?
large, squamous epithelial cells with numerous attached rods.
What happens when 10% KOH is added to a discharge sample?
It produces a fishy odor.
What are the media of choice for cultivating Gardnerella?
-5% sheep blood and chocolate agars
-Columbia colistin-nalidixic acid (CNA) agar
-Human blood bilayer Tween agar (HBT) for isolating G. vaginalis from the female genital tract
