Gram Stain Compendium

 


The Common Players
Gram + (blue)Gram - (red)
CocciStaph
Strep
Neisseria
Moraxella
("NEver MOre") - aerobic
RodsNocardia
Clostridia
Bacillus
Corynebacter
Listeria
("NO CLueless BAngers COuld LIsten")
Most other bugs
Yeast:candida
Anaerobes:bacteroides, clostridium, peptostrepto - Clindamycin covers.
Obligate Intracellulars:mycoplasma, chlamydia, rickettsia, coxiella
Spirochetes:treponemes, boriella, leptospira
Proteolytic:strep, clostridia

 

Specific Organ Systems

CSF
Gram +Gram -
Cocci Grp B Strep - meningitis in newborns
Strep pneumo - meningitis in adults
Neisseria (diplococci) - epidemic meningitis
Rods Listeria - meningitis in neonates H flu - meningitis in children
E coli - meningitis in infants
YeastsCryptococcus neoformans - chronic meningitis in immunocompromised
Candida - seen in systemic candida

 

Resp (Pneumonias)
Gram +Gram -
Cocci Strep pneumo - most common CAP
Staph aureus - in hospitalized patients
Moraxella (diplococci) - in emphysema & asthma
Rods Nocardia (branched rods) - in immunocompromised Klebsiella - most common hospital acquired
Pseudomonas - in CF
H flu - in underlying resp disease
YeastsCandida - in immunocompromised

 

Urinary
Gram +Gram -
Cocci Enterococcus - hospital acquired UTI
Staph saprophyticus - UTI in young patients or anyone with foley cath
Rods E coli - most common UTI
Pseudomonas - common hospital acquired UTI
Klebsiella - associated with kidney stones
Proteus - associated with kidney stones
YeastsCandida - in urine of patients on ABX or with diabetes

 

Genital
Gram +Gram -
Cocci Gardnerella vaginalis - bacterial vaginosis
Neisseria gonorrhea (diplococci) = gonorrhea in ; need culture in
Gardnerella vaginalis - bacterial vaginosis
Rods Mobiluncus curtisi - bacterial vaginosis Mobiluncus curtisi - bacterial vaginosis
Yeasts

 

Wound Infections
Gram +Gram -
Cocci Staph aureus - clusters or tetrads - infections at various sites
Grp A Strep - chains - infections at various sites
Enterococcus - normal fecal flora - abdominal wound infections
Pasteurella Multocida - from animal bites
Rods Clostridium - long, wide rods - gas gangrene
Actinomyces - branched - mouth or jaw wound infections
Pseudomonas aeruginosa - long, narrow rods - burn site infections, hot-tub folliculitis
Proteus mirabilis - long, narrow rods - burn site infections
Bacteroides - intra-abdominal abscesses
Yeasts
OtherMixed fusiform and spiral bugs - "Trench mouth" (ulcerative dental infection)

 

Joint Infections
Gram +Gram -
Cocci Staph aureus - clusters - common cause of bacterial arthritis
Grp A Strep - chains - bacterial arthritis (less common)
Neisseria gonorrhea (diplococci) - bacterial arthritis 2o systemic gonococcal disease
Rods H. flu - bacterial arthritis in children
Yeasts

 

Eye Infections
Gram +Gram -
Cocci Strep pneumo (diplococci) - common cause of bacterial conjunctivitis
Staph aureus - clusters - common cause eyelid & corneal infections
Moraxella (diplococci) - bacterial conjunctivitis
Rods H. flu - conjunctivitis epidemics in day care centers
Yeasts

 

Stool Bacteria
Gram +Gram -
Cocci
Rods Salmonella - from poultry, cause food poisoning
Shigella - highly infectious, bloody mucoid diarrhea (dysentery)
Campylobacter - animal vectors, causes diarrhea in humans
Yeasts