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Bacteremia continues to result in significant morbidity and mortality, particularly in patients who are immunocompromised. Currently, patients with suspected bacteremia are empirically administered broad-spectrum antibiotics, as definitive diagnosis relies upon the use of blood cultures, which impose significant delays in and limitations to pathogen identification. To address the limitations of growth-based identification, the sequence variability of the 16S rRNA gene of bacteria was targeted for rapid identification of bacterial pathogens isolated directly from blood cultures using a fluorescence-based PCR-single-strand conformation polymorphism (SSCP) protocol. Species-specific SSCP patterns were determined for 25 of the most common bacterial species isolated from blood cultures; these isolates subsequently served as a reference collection for bacterial identification for new cases of bacteremia. A total of 272 blood-culture-positive patient specimens containing bacteria were tested. A previously determined SSCP pattern was observed for 251 (92%) specimens, with 21 (8%) specimens demonstrating SSCP patterns distinct from those in the reference collection. Time to identification from blood culture positivity ranged from 1 to 8 days with biochemical testing, whereas identification by fluorescence-based capillary electrophoresis was obtained as early as 7 h at a calculated cost of $10 (U.S. currency) per specimen when tested in batches of 10. Limitations encountered included the inability to consistently detect mixed cultures as well as some species demonstrating identical SSCP patterns. This method can be applied directly to blood cultures or whole-blood specimens, where early pathogen identification would result in a timely diagnosis with possible implications for patient management costs and the mortality and morbidity of infections.

Susceptibility testing of 1,688 Haemophilus influenzae isolates found 484 ampicillin-resistant strains; 474 strains (28.4%) were beta-lactamase positive, and 5 strains (0.4%) were non-beta-lactamase producers. Restriction enzyme digestion of the beta-lactamase amplicon determined that, of 157 strains, 11 (7.0%) contained ROB-1 beta-lactamase and 146 (93.0%) contained a TEM-type beta-lactamase.

The in vitro activity of cilofungin against 100 Candida species was compared with 5-flucytosine. amphotericin B and ketoconazole by two laboratories independently and in a blinded fashion using a macrotitre dilution broth method in saam-f medium. Cilofungin showed good in vitro activity against Candida albicans. Candida tropicalis and Candida glabrata (90% minimal inhibitory concentration [MIC] 3.2 μg/mL) but was inactive against other Candida species. When testing the susceptibility of cilofungin, 5-flucytosine and amphotericin B at the two centres, approximately 90% of the Candida strains had MICs differing by fourfold or less. However, when testing susceptibility of ketoconazole, only 51% of the Candida strains had MIC differences fourfold or less. MIC susceptibility testing with cilofungin, 5-flucytosine and amphotericin B in saam-f medium is reproducible.

Aerobic gram-negative infections are treated with aminoglycosides, but it is difficult to achieve safe yet effective dosages in individual patients using a standard dosing formula. Serum aminoglycoside levels are monitored to determine dosage adjustments. We compared enzyme immunoassay, bioassay, and fluorescence immunoassay procedures for measuring gentamicin and tobramycin levels in patients' sera, and in pooled human sera containing added gentamicin and tobramycin. The enzyme immunoassay procedure provided the most acceptable method for monitoring serum aminoglycoside levels on the bases of precision, cost, and turnaround time.

This study compared the sensitivity and specificity of four test systems in detecting Haemophilus influenzae type b, Neisseria meningitidis, Streptococcus pneumoniae, and gram-negative organisms in cerebrospinal fluid (CSF), versus culture. The tests used on CSF from 155 patients with meningitis were the Phadebact coagglutination (CoA) test, the Directigen latex agglutination (LA) test, counterimmunoelectrophoresis (CIE), and the Limulus amebocyte lysate (LAL) test. The sensitivity for patients with bacterial meningitis was 78% (18/23) for LA, 78% (25/32) for CoA, and 67% (18/27) for CIE for detection of H. influenzae type b; 71% (10/14) for CoA, 100% (6/6) for LA, and 50% (6/13) for CIE in detecting S. pneumoniae; and 33% (1/3) for LA and 50% (2/4) for CIE in detecting N. meningitidis. LAL had a sensitivity of 77% (37/48) in detecting CSF gram-negative endotoxin. The specificities of those with bacterial meningitis for H. influenzae, S. pneumoniae, and N. meningitidis tested by LA were, respectively, 100% (35/35), 96% (50/52), and 100% (54/54); for H. influenzae and S. pneumoniae using CoA 97% (62/64) and 96% (80/83); for H. influenzae, S. pneumoniae, and N. meningitidis using CIE 67% (18/27), 50% (6/12), and 50% (2/4). The specificity of LAL was 86% (38/44). The detection of bacterial antigen from CSF in patients with meningitis by commercial agglutination tests is more sensitive than CIE and is highly specific.

The in vitro activity of lomefloxacin, a new difluorinated quinolone antimicrobial was compared to comparative agents against organisms causing sexually transmitted diseases. Against Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, Neisseria gonorrhoeae, and Haemophilus ducreyi, lomefloxacin exhibited MIC90 of 2.0, 8.0, 8.0, less than or equal to 0.015, and 0.003 micrograms/ml, respectively. Overall, the lomefloxacin activity was very similar to ciprofloxacin.