22 results
Blood culture contaminants
Grouped by gram negative vs gram positive vs other as well as never/maybe/probably
Some additional
Blood culture contaminants ... Grouped by gram negative ... #Infections #Microbiology ... #Micro #Differential ... Bloodculture #Bloodcx #bcx
My Patient with Infective Endocarditis (IE) Has Negative Blood Cultures
 - Did they receive antibiotics prior
with Infective Endocarditis ... (IE) Has Negative ... Blood Cultures ... #Infective #Endocarditis ... #Diagnosis #Management
Causes of blood culture negative infective endocarditis

Bartonella spp, Brucella spp, Coxiella burnetii, Chlamydia spp, Tropheryma whipplei,
Causes of blood culture ... negative infective ... endocarditis Bartonella ... #negative #Endocarditis ... InfectiousDiseases #Microbiology
Duke's Criteria for Infective Endocarditis
Definite IE - Pathologic Criteria:
 • Pathologic lesions - vegetation or intracardiac
for Infective Endocarditis ... demonstrating active endocarditis ... Immunologic phenomena • Micro ... : + bcxs that do ... criteria #Infective #Endocarditis
Streptocccus Pneumoniae
Microbiology: Gram Positive, Alpha-hemolytic, Catalase Negative
Epidemiology - 10% adult carriers:
 • Most common cause of:
Streptocccus Pneumoniae Microbiology ... Alpha-hemolytic, Catalase Negative ... peritonitis, and endocarditis ... sinus • Sputum culture ... #diagnosis #management
How to Determine a Contaminant vs True Infection 

What is the organism? Most 
common contaminants:
• Coagulase-negative ... How many blood culture ... species from the micro ... Contamination #Diagnosis #BCx
Endocarditis Summary

Who?
Infectious:
• Pre-existing valvular disease
• Prosthetic valve
• Congenital heart disease
• IV substance use
• IV catheter
• Recent
Hypercoagulable (APLAS) Microbiology ... : Blood cultures ... • Coagulase-negative ... • Blood cultures ... #diagnosis #management
Guide to Interpretation of Positive Blood Cultures

I arrange the potential Gram stain results that one can
Positive Blood Cultures ... call from the micro ... Fewer positive cultures ... reason to go to micro ... Interpretation #Laboratory #Microbiology
Capnocytophaga
Pathogen: Capnocytophaga
 • 9 species, C. canimorsus responsible for the majority of infections
 • Gram-negative rod,
infections • Gram-negative ... 13%), Pneumonia, Endocarditis ... microorganism (Culture ... Capnocytophaga #canimorsus #microbiology ... infectiousdiseases #diagnosis #management
Acinetobacter baumanii on culture and microscopy
 - MacConkey agar - Lactose Negative
 - gram negative (often
agar - Lactose Negative ... - gram negative ... esp. from blood cx ... clinical #microscopy #microbiology ... #culture