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Category: Clinical Microbiology
Peptostreptococcus, Finegoldia, Anaerococcus, Peptoniphilus, Veillonella, and Other Anaerobic Cocci, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555816728/9781555814632_Chap48-1.gif /docserver/preview/fulltext/10.1128/9781555816728/9781555814632_Chap48-2.gifAbstract:
The organisms included in this chapter are obligately anaerobic, non-spore-forming, sometimes elongated cocci. The genera Anaerococcus, Anaerosphaera, Finegoldia, Gallicola, Parvimonas, Peptococcus, Peptoniphilus, and Peptostreptococcus, as well as the newly described taxon Murdochiella , are gram-positive, coccobacillary, or, occasionally, coccoid cells. F. magna is the most pathogenic and one of the most frequently isolated gram-positive anaerobic coccal species found in human clinical specimens. Molecular methods, such as nucleic acid probe hybridization and PCR amplification, are not yet standardized or available commercially for the direct demonstration of medically important gram-positive anaerobic cocci from clinical specimens. New information regarding the antimicrobial susceptibilities of gram-positive anaerobic cocci is sparse compared with the information available for other anaerobic species. Bacteria present in pure culture or in large numbers are probably of major importance, as are organisms recovered in multiple cultures and isolated from normally sterile sites. Furthermore, Gram stain results can guide the laboratory in choosing media for optimal recovery of the predicted organisms. The significance of finding anaerobic gram-positive and gram-negative cocci in clinical specimens depends on the specimen and the likelihood that it was contaminated by the microbiota of the skin or mucous membranes. Hence, interpretation of culture results is dependent on the nature and quality of the specimen submitted to the laboratory.
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Flowchart with key characteristics for identification and differentiation of gram-positive anaerobic cocci. a, SPS testing was done using an SPS disk (Anaerobe Systems, Morgan Hill, CA). All gram-positive anaerobic cocci are sensitive to SPS except for P. anaerobius, which gives a zone of inhibition of ≥12 mm around an SPS disk. P. micros also exhibits a zone of inhibition with SPS; however, the zone is usually <12 mm in size. +, no zone or the zone of inhibition is <12 mm; –, the zone of inhibition is ≥12 mm. b, all the enzymatic tests were done by using the Rapid ID 32A system (API bioMérieux, Marcy l'Etoile, France) according to the manufacturer's instructions. β-Gal, β-galactosidase; α-Glu, α-glucosidase; β-Gur, β-glucuronidase; ArgA, arginine arylamidase (AMD); ProA, proline AMD; PheA, phenylalanine AMD; PyrA, pyroglutamyl AMD; GGA, glutamyl glutamic acid AMD; ALP, alkaline phosphatase. c, glucose fermentation tests were performed using PRAS peptone-yeast-glucose (PYG) broth (Anaerobe Systems, Morgan Hill, CA). A pH of ≤5.5 in the PYG tubes was interpreted as positive and a pH of ≥5.9 as negative fermentation. d, described by D. A. Murdoch and I. J. Mitchelmore ( 80 ).
Flowchart with key characteristics for identification and differentiation of gram-positive anaerobic cocci. a, SPS testing was done using an SPS disk (Anaerobe Systems, Morgan Hill, CA). All gram-positive anaerobic cocci are sensitive to SPS except for P. anaerobius, which gives a zone of inhibition of ≥12 mm around an SPS disk. P. micros also exhibits a zone of inhibition with SPS; however, the zone is usually <12 mm in size. +, no zone or the zone of inhibition is <12 mm; –, the zone of inhibition is ≥12 mm. b, all the enzymatic tests were done by using the Rapid ID 32A system (API bioMérieux, Marcy l'Etoile, France) according to the manufacturer's instructions. β-Gal, β-galactosidase; α-Glu, α-glucosidase; β-Gur, β-glucuronidase; ArgA, arginine arylamidase (AMD); ProA, proline AMD; PheA, phenylalanine AMD; PyrA, pyroglutamyl AMD; GGA, glutamyl glutamic acid AMD; ALP, alkaline phosphatase. c, glucose fermentation tests were performed using PRAS peptone-yeast-glucose (PYG) broth (Anaerobe Systems, Morgan Hill, CA). A pH of ≤5.5 in the PYG tubes was interpreted as positive and a pH of ≥5.9 as negative fermentation. d, described by D. A. Murdoch and I. J. Mitchelmore ( 80 ).
Changes in classification of gram-positive anaerobic coccal species from human clinical specimens
Changes in classification of gram-positive anaerobic coccal species from human clinical specimens
Differential characteristics of Peptostreptococcus, Peptococcus, Peptoniphilus, Finegoldia, and Anaerococcus a
a Data are mainly from Murdoch ( 82 ) and Song et al. ( 118 ); Undescribed strains that cluster in whole-cell composition were assessed by pyrolysis mass spectrometry. VFA, volatile fatty acids; A, acetate; B, butyrate; IV, isovalerate; IC, isocaproate; C, n-caproate; SPS, sodium polyanethol sulfonate; ALP, alkaline phosphatase; ADH, arginine dihydrolase; α-Gal, α-galactosidase; β-Gal, β-galactosidase; α-Glu, α-glucosidase; β-Gur, β-glucuronidase; ArgA, arginine arylamidase (AMD); ProA, proline AMD; PheA, phenylalanine AMD; Leu, leucine AMD; PyrA, pyroglutamyl AMD; –, >90% negative; w, weakly positive; +, >90% positive; d, different reactions.
Differential characteristics of Peptostreptococcus, Peptococcus, Peptoniphilus, Finegoldia, and Anaerococcus a
a Data are mainly from Murdoch ( 82 ) and Song et al. ( 118 ); Undescribed strains that cluster in whole-cell composition were assessed by pyrolysis mass spectrometry. VFA, volatile fatty acids; A, acetate; B, butyrate; IV, isovalerate; IC, isocaproate; C, n-caproate; SPS, sodium polyanethol sulfonate; ALP, alkaline phosphatase; ADH, arginine dihydrolase; α-Gal, α-galactosidase; β-Gal, β-galactosidase; α-Glu, α-glucosidase; β-Gur, β-glucuronidase; ArgA, arginine arylamidase (AMD); ProA, proline AMD; PheA, phenylalanine AMD; Leu, leucine AMD; PyrA, pyroglutamyl AMD; –, >90% negative; w, weakly positive; +, >90% positive; d, different reactions.
Characteristics of genera of gram-negative cocci a
a Modified from reference 72 . A, acetate; B, butyrate; IB, isobutyrate; V, valerate; IV, isovalerate; C, n-caproate; P, propionate; L, lactate. Parentheses indicate possible production.
b Glucose fermentation tests were performed using pre-reduced, anaerobically sterilized PRAS peptone-yeast-glucose broth tubes (Anaerobe Systems, Morgan Hill, CA). The PRAS tubes were inoculated from an actively growing broth culture (without carbohydrate). A pH of ≤5.5 in the PRAS tubes was interpreted as positive, a pH of 5.6 to 5.8 as weakly positive, and a pH of ≥5.9 as negative fermentation.
Characteristics of genera of gram-negative cocci a
a Modified from reference 72 . A, acetate; B, butyrate; IB, isobutyrate; V, valerate; IV, isovalerate; C, n-caproate; P, propionate; L, lactate. Parentheses indicate possible production.
b Glucose fermentation tests were performed using pre-reduced, anaerobically sterilized PRAS peptone-yeast-glucose broth tubes (Anaerobe Systems, Morgan Hill, CA). The PRAS tubes were inoculated from an actively growing broth culture (without carbohydrate). A pH of ≤5.5 in the PRAS tubes was interpreted as positive, a pH of 5.6 to 5.8 as weakly positive, and a pH of ≥5.9 as negative fermentation.
Antimicrobial susceptibilities of gram-positive anaerobic cocci a
a Data were obtained from the Wadsworth Anaerobic Bacteriology Laboratory. Strains were tested by CLSI (formerly NCCLS) agar dilution procedures. Pen, penicillin; Amp-Sul, amoxicillin-sulbactam; Amp-Clav, amoxicillin-clavulanic acid; Pip-Tazo, piperacillin-tazobactam; Cefox, cefoxitin; Imi, imipenem; Clinda, clindamycin; Metro, metronidazole; Cipro, ciprofloxacin; ND, no data.
b One of 5 strains showed resistance.
c Three of 16 strains showed resistance.
d Two of 15 strains showed resistance.
e Three of 16 strains showed resistance.
f One of 5 strains showed resistance.
g Data were obtained from Könönen et al. ( 63 ). Strains were tested by the Etest (AB Biodisk).
h Numbers in parentheses are applied breakpoints for testing the antimicrobial agents.
i Results for this drug combination are given for amoxicillin and piperacillin.
Antimicrobial susceptibilities of gram-positive anaerobic cocci a
a Data were obtained from the Wadsworth Anaerobic Bacteriology Laboratory. Strains were tested by CLSI (formerly NCCLS) agar dilution procedures. Pen, penicillin; Amp-Sul, amoxicillin-sulbactam; Amp-Clav, amoxicillin-clavulanic acid; Pip-Tazo, piperacillin-tazobactam; Cefox, cefoxitin; Imi, imipenem; Clinda, clindamycin; Metro, metronidazole; Cipro, ciprofloxacin; ND, no data.
b One of 5 strains showed resistance.
c Three of 16 strains showed resistance.
d Two of 15 strains showed resistance.
e Three of 16 strains showed resistance.
f One of 5 strains showed resistance.
g Data were obtained from Könönen et al. ( 63 ). Strains were tested by the Etest (AB Biodisk).
h Numbers in parentheses are applied breakpoints for testing the antimicrobial agents.
i Results for this drug combination are given for amoxicillin and piperacillin.