Microbiology

Gram positive cocci in chains; includes S. agalactiae, S. anginosus, S. bovis, S. canis, S. equi, S. equisimilis, S. iniae, S. intermedius, S. milleri, S. mitis, S. morbillorum, S. mutans, S. oralis, S. pneumoniae, S. pyogenes, S. sanguis, S. salivarius.

The classification of streptococci is always changing and I do not think even microbiologists truly understand it.

Epidemiologic Risks

Here is, I think, a key finding for S. aureus and Streptococcus bacteremia (Pubmed)

"An intensive search for metastatic infectious foci was performed including 18F-fluorodeoxyglucose-positron emission tomography in combination with low-dose computed tomography scanning for optimizing anatomical correlation (FDG-PET/CT) and echocardiography in the first 2 weeks of admission. Metastatic infectious foci were detected in 84 of 115 (73%) patients. Endocarditis (22 cases), endovascular infections (19 cases), pulmonary abscesses (16 cases), and spondylodiscitis (11 cases) were diagnosed most frequently. The incidence of metastatic infection was similar in patients with Streptococcus species and patients with S. aureus bacteremia. Signs and symptoms guiding the attending physician in the diagnostic workup were present in only a minority of cases (41%). "

S. agalactiae aka Group B strep: part of the human GI tract.

S. anginosus: mouth flora.

S. bovis: gi flora. Now called Streptococcus gallolyticus.

S. canis: dogs and other animals. Its group G.

S. constellatus: mouth flora.

S. equi/Streptococcus equi subspecies zooepidemicus: horses.

S. subspecies equisimilis (was S. equisimilis): human.

S. gallolyticus: gi tract. Was S. bovis.

S. iniae: farm raised tilapia fish.

S. intermedius: mouth flora.

S. milleri: mouth flora.

S. mitis: mouth flora.

S. morbillorum: mouth flora.

S. mutans: mouth flora.

S. oralis: mouth flora.

S. pneumoniae: part of life, human to human spread. There is a vaccine, its efficacy is variable, but it is best at preventing death, decreasing mortality by 40% (PubMed).

S. pyogenes: part of life, human to human spread.

S. sanguis: mouth flora.

S. salivarius: mouth flora. It is a cause of post LP meningitis (PubMed).

S. suis: pigs (PubMed).

Syndromes

S. agalactiae: neonatal sepsis and bacteremia in both mother and child. Immunoincompetent adults (diabetes, ETOH, cancer) can get bacteremia and septic arthritis.

S. anginosus: endocarditis and is associated with abscess of the brain, liver, gi. This Streptococcus that can form abscesses all by its lonesome.

S. bovis: now S. gallolyticus.

Endocarditis is more frequent among patients with S. bovis biotype I, whereas bacteriemia due to biotype II species is more likely from biliary system (PubMed).

S. canis: In 54 patients, soft tissue infection (n = 35), bacteremia (n = 5), urinary infection (n = 3), bone infection (n = 2) and pneumonia (n = 1) (PubMed).

S. constellatus: endocarditis and is associated with abscesses of all kinds brain, liver, gi.

S. equis/Streptococcus equi subspecies zooepidemicus: soft tissue infection, bacteremia, endocarditis and meningitis although related to horses, the cases of meningitis were associated with drinking unpasteurized milk (PubMed).

Streptococcus dysgalactiae subspecies equisimilis (S. equisimilus): soft tissue infection (In Finland it is the leading cause (PubMed). I would bet in Oregon as well. Bacteremia and endocarditis.

Streptococcus gallolyticus: bacteremia and endocarditis has a high association with colonic malignancy (PubMed). If it is in the blood, the patient needs a colonoscopy. The reason? It turns out the beast likes to adhere to proteins made by bowel tumor (PubMed).

Streptococcus gallolyticus subsp. pasteurianus caused meningitis; the source was hemorrhoids (PubMed). Seriously, who would name a rectal bug pasteurianus? Just say it out loud without giggling.

S. iniae: soft tissue infection, bacteremia and endocarditis.

S. intermedius: bacteremia and endocarditis.

S. milleri: endocarditis and is associated with abscess in the brain, liver, gi.

S. mitis: bacteremia and endocarditis.

S. morbillorum: bacteremia and endocarditis.

S. mutans: bacteremia and endocarditis.

S. oralis: bacteremia and endocarditis.

S. pneumoniae: sepsis, meningitis, pneumonia, empyema, endocarditis, pericarditis, bacteremia in HIV, Hemolytic Uremic Syndrome.

S. pyogenes: cellulitis, toxic shock syndrome, rheumatic fever, pharyngitis, vaginitis, glomerulonephritis.

S. sanguis: bacteremia and endocarditis.

S. salivarius: bacteremia and endocarditis. It is a cause of post LP meningitis (PubMed).

S. suis: In SE Asia the most common cause of meningitis (PubMed).

Treatment

S. agalactiae:

Any beta lactam (except aztreonam) will do, penicillin is still the best. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. anginosus:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. bovis:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work. Did you see that need for evaluation of colonic cancer in a patient who is bacteremic with this organism? S. canis Any antibiotic will work, but use a Beta lactam.

S. constellatus:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. equi:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

Streptococcus dysgalactiae subspecies equisimilis (S. equisimilus):

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. gallolyticus:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work. Did you see that need for evaluation of colonic cancer in a patient who is bacteremic with this organism? S. canis Any antibiotic will work, but use a Beta lactam.

S. iniae:

Any beta lactam (except aztreonam) will do, penicillin is still the best. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work,

S. intermedius:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. milleri

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. mitis:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. morbillorum:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. mutans:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. oralis:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. pneumoniae:

S. pneumoniae has three forms of resistance to penicillin:

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporin or vancomycin.

Often resistant to tetracyclines, macrolides, tmp/sulfa and quinolones. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work, If allergies, vancomycin or linezolid are reasonable alternatives.

S. pyogenes:

Any beta lactam (except aztreonam) will do, penicillin is still the best. If allergies, vancomycin or linezolid. are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work, macrolides and doxycycline are still active.

BUT. If your are trying to prevent Rheumatic Fever, do not trust anything by a beta-lactam (PubMed).

Necrotizing fasciitis or Toxic Shock Syndrome, debride the wound. No matter that it will not look infected. If you don't debride the wound, the patient will die. Also penicillin to kill the bug PLUS clindamycin (900 q 8 to interfere with toxin production) PLUS IVIG (1 gram/kg on day one and 0.5 gm/kg on day 2 and 3 (PubMed)) to bind toxin (an area of controversy (PubMed), I am a believer). IVIG may not help in children (PubMed).

S. sanguis

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. salivarius

Sensitive: MIC <0.1 ug/ml. Use penicillin.

Intermediate: MIC 0.1 - 1.0 ug/ml use lots of penicillin except for meningitis, where you should use a third generation cephalosporin. For endocarditis use 4 weeks of penicillin PLUS 2 weeks of gentamicin.

Resistant: MIC > 2 ug/ml use a third generation cephalosporins OR vancomycin. For endocarditis use 6 weeks of penicillin PLUS 6 weeks of gentamicin.

Macrolide resistance is increasing. If allergies, vancomycin or linezolid are reasonable alternatives. Never trust levofloxacin or ciprofloxacin, but gatifloxacin or moxifloxacin may have good enough MIC's to work.

S. suis:

Use penicillin. In Vietnam, resistance to tetracycline, erythromycin and chloramphenicol is increasing.

ICD9 Codes (Soon to be supplanted by ICD10)

Streptococcal NEC 041.00; ; generalized (purulent) 038.0; A 041.01; B 041.02; C 041.03; D [enterococcus] 041.04; G 041.05; ; septicemia 038.0; sore throat 034.0.