TABLE 2.
Frequency of β-lactamase production in P. intermedia, P. nigrescens, and P. pallens isolates, presented by site of infection or recovery, geographic location, and time of isolation
| Source or time of isolation | No. (%) of isolates
|
|||||
|---|---|---|---|---|---|---|
|
P. intermedia
|
P. nigrescens
|
P. pallens
|
||||
| Total | β-Lactamase positive | Total | β-Lactamase positive | Total | β-Lactamase positive | |
| Extraoral | 48 | 13 (27.1) | 43 | 15 (34.9) | ||
| Oral | 25 | 8 (32.0) | 41 | 9 (22.0) | 14 | 8 (57.1) |
| United States | 38 | 12 (31.6) | 22 | 11 (50.0)a | ||
| Finland | 35 | 9 (25.7) | 62 | 13 (21.0) | 14 | 8 (57.1) |
| 1985–1990 | 33 | 5 (15.2)a | 23 | 7 (30.4) | ||
| 1991–1995 | 40 | 16 (40.0) | 61 | 17 (27.9) | 14 | 8 (57.1) |
| All isolates | 73 | 21 (28.8) | 84 | 24 (28.6) | 14 | 8 (57.1) |
a
χ2 test, P < 0.05.