Table 2.
Microbiological data
| Non-purulent cellulitis n=320 |
Wound infection or purulent cellulitis n=44 |
Cutaneous abscess n=169 |
Total n =533 |
|
|---|---|---|---|---|
| Any microbiological culture obtained | 246 (77) | 39 (89) | 155 (92) | 440 (83) |
| Wound or other surface culture | 44 (14) | 22 (50) | 16 (9) | 82 (15) |
| Abscess material | 5 (2) | 3 (7) | 130 (77) | 138 (26) |
| Tissue or aspirate | 19 (6) | 9 (20) | 7 (4) | 35 (7) |
| Blood | 225 (70) | 24 (55) | 95 (56) | 344 (65) |
| Any microorganism identified a | 48 (15) | 26 (59) | 128 (76) | 202 (38) |
| Aerobic gram-positive organism | 46 (96) | 25 (96) | 119 (93) | 190 (94) |
| Staphylococcus aureus | 23 (48) | 21 (81) | 83 (65) | 127 (63) |
| Methicillin-susceptible | 13 (27) | 10 (38) | 35 (27) | 58 (29) |
| Methicillin-resistant | 9 (19) | 9 (35) | 46 (36) | 64 (32) |
| Susceptibility not performed | 1 (2) | 2 (8) | 2 (2) | 5 (2) |
| Streptococcal species | 15 (31) | 4 (15) | 40 (31) | 59 (29) |
| β-hemolytic streptococcus | 12 (25) | 3 (12) | 22 (17) | 37 (18) |
| S. anginosus-milleri group | 1 (2) | 0 | 14 (11) | 15 (7) |
| Other alpha-hemolytic streptococcus | 2 (4) | 1 (4) | 5 (4) | 8 (4) |
| Other streptococci | 0 | 0 | 2 (2) | 2 (1) |
| S. aureus or streptococci | 33 (69) | 24 (92) | 114 (89) | 171 (85) |
| Coagulase-negative staphylococcus | 15 (31) | 4 (15) | 14 (11) | 33 (16) |
| Enterococcus species | 2 (4) | 0 | 0 | 2 (1) |
| Aerobic gram-negative organism b,c | 6 (13) | 3 (12) | 11 (9) | 20 (10) |
| Only gram-negative organism(s) identified d | 1 (2) | 1 (4) | 2 (2) | 4 (2) |
| Anaerobic organism(s) | 3 (6) | 1 (4) | 13 (10) | 17 (8) |
| Other | 3 (6) | 1 (4) | 6 (5) | 10 (5) |
| Positive blood culture e | 15 (5) | 1 (2) | 6 (4) | 22 (4) |
Data presented as n (%) unless otherwise noted.
Denominator for the proportion reported for each individual organism is the number of cases where an organism was identified
When excluding wound or other surface cultures, aerobic gram-negative organisms were isolated in 13 (6%) cases
Isolates include Klebsiella species (3), Pseudomonas aeruginosa (2), Pasturella multocida (2), E. coli (1), Proteus mirabilis (1), Serratia marcescens (1), Acinetobacter species (1), Aeromonas hydrophila (1), Haemophilus parainfluenzae (1), mixed gram-negative flora (1), non-lactose fermenting gram-negative rod, unspecified (2), lactose fermenting gram-negative rod, unspecified (1), gram-negative rod, unspecified
Gram-positive or anaerobic organisms were also isolated in 16 of the 20 cases
12 (2%) were judged to represent true bacteremia, including MSSA (4), MRSA (3), beta-hemolytic streptococci (4), and polymicrobial with MRSA, Streptococcus milleri, and coagulase-negative staphylococcus (1)