Volume 4, Number 1—March 1998
Dispatch
Laboratory Survey of Drug-Resistant Streptococcus pneumoniae in New York City, 1993—1995
Table 2
Penicillin susceptibility testing protocols for Strepococcus pneumoniae in New York City hospital laboratories
| No. of laboratoriesa | 1993 No. (%) | 1994 No. (%) | 1995 No. (%) |
|---|---|---|---|
| Screened with oxacillin disk | 55 (82) | 63 (97) | 65 (97) |
| Screened all isolates | 38 (57) | 56 (86) | 59 (88) |
| Screened only sterile | 9 (13) | 6 (9) | 6 (9) |
| Other | 8 (12) | 1 (2) | 0 |
| Performed penicillin MIC test MIC-tested | 39 (58) | 51 (78) | 56 (84) |
| All isolates | 10 (15) | 9 (14) | 7 (10) |
| Oxacillin-resistant only | 18 (27) | 39 (60) | 42 (63) |
| Sterile isolates only | 5 (7) | 1 (2) | 0 (0) |
| By request only | 4 (6) | 1 (2) | 5 (7) |
| Other | 2 (3) | 1 (2) | 2 (3) |
| Penicillin MIC techniqueb Antibiotic gradient stripc | 11(16) | 41 (63) | 50 (75) |
| Automated testsc | 21 (31) | 9 (14) | 2 (3) |
| Broth dilution | 8 (12) | 11 (17) | 5 (7) |
| Unknown | 2 (3) | 3 (5) | 0 |
| Conformed with NCCLS guidelinesd | 15 (22) | 38 (58) | 46 (69) |
aTotal number of laboratories responding to survey in 1993, 1994, 1995 was 67, 65, 67, respectively.
b13 laboratories used more than one MIC technique.
cAntibiotic gradient strip: e.g., E-test. Automated tests: e.g., Microscan, Vitek.
dNCCLS=National Committee for Clinical Laboratory Standards. Screened all S. pneumoniae isolates with oxacillin disk diffusion test and confirmed resistance with approved penicillin MIC test.
