49 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 ... #Ddx #Diagnosis
Capnocytophaga spp on Culture and Blood Smear
Associated w/ dog/human oral flora, can cause bacteremia in immunocompromised
Capnocytophaga spp ... anaerobe; narrow Gram negative ... richdavisphd #Capnocytophaga ... #Smear #clinical ... #microscopy #microbiology
Capnocytophaga
Pathogen: Capnocytophaga
 • 9 species, C. canimorsus responsible for the majority of infections
 • Gram-negative rod,
infections • Gram-negative ... Cholecystitis Diagnosis ... microorganism (Culture ... fusiform gram-negative ... #canimorsus #microbiology
Causes of blood culture negative infective endocarditis

Bartonella spp, Brucella spp, Coxiella burnetii, Chlamydia spp, Tropheryma whipplei,
Causes of blood culture ... negative infective ... #differential #diagnosis ... #negative #Endocarditis ... InfectiousDiseases #Microbiology
Capnocytophaga Canimorsus Skin Rash

40 M presents w/ N, V, severe epigastric pain. SHx: smoker, drinks 18
fastidious gram-negative ... Myocarditis & culture-negative ... the key to the diagnosis ... is difficult to culture ... #dermatology #clinical
Duke's Criteria for Infective Endocarditis
Definite IE - Pathologic Criteria:
 • Pathologic lesions - vegetation or intracardiac
demonstrated by culture ... Definite IE - Clinical ... positive blood culture ... Immunologic phenomena • Micro ... #Endocarditis #diagnosis
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
Streptocccus Pneumoniae
Microbiology: Gram Positive, Alpha-hemolytic, Catalase Negative
Epidemiology - 10% adult carriers:
 • Most common cause of:
Streptocccus Pneumoniae Microbiology ... Alpha-hemolytic, Catalase Negative ... Diagnosis: • Physical ... sinus • Sputum culture ... #diagnosis #management
Tuberculosis Testing

LATENT TB
• LTBI is diagnosed when an asymptomatic patient has a positive TST or IGRA
result with no clinical ... because false-negative ... Mycobacterial culture ... Liquid and solid cultures ... Mycobacterial culture
Diagnosing Brucellosis
Epidemiological Exposures
- Endemic Regions
- Clinical Micro Lab Technicians
- Animal/Vaccine Exposure: Vets, Slaughterhouse workers, hunters
- Unpasteurized
Diagnosing Brucellosis ... Endemic Regions - Clinical ... Micro Lab Technicians ... cheese, ice cream) Clinical ... : Culture (blood