Species of coagulase-negative staphylococci isolated from urine specimens submitted from both inpatients and outpatients to the clinical microbiology laboratory of a teaching hospital were identified with a biotyping system, with species then correlated by clinical features and antimicrobial susceptibility. Of 145 isolates, 102 (70%) were Staphylococcus epidermidis, 24 (17%) were Staphylococcus saprophyticus, 7 (4.7%) were Staphylococcus haemolyticus, 4 (2.8%) were Staphylococcus hominis, 3 (2.1%) were Staphylococcus simulans, and 5 (3.4%) were other species. Features characterizing persons with bacteriuria with S. saprophyticus compared with bacteriuria with any other species included female sex (95% versus 52%), young age (median age, 22 years versus 61 years), ambulatory status (hospital outpatients, 86% versus 23%), and absence of indwelling catheters (4.5% versus 49%). All other coagulase-negative staphylococci were isolated in a setting suggesting nosocomial acquisition, were more frequently resistant to common antimicrobial agents (42% multiply resistant versus 4.2% of S. saprophyticus), and were not distinguished by clinical features. Novobiocin susceptibility, with a sensitivity of 100o and specificity of 96%, provided a simple and reliable test for differentiation of S. saprophyticus from other coagulase-negative staphylococci and should be routinely used for urinary tract specimens in the clinical laboratory.

Antibody-coated bacteria were found in only two of 34 urine sediments from 19 catheterized patients infected with a single epidemic strain of Pseudomonas aeruginosa, whereas 12 of 19 urine sediments from 16 outpatients contained antibody-coated P. aeruginosa. In urine sediments, individual cells and microcolonies of the epidemic strain of P. aeruginosa were enclosed in ruthenium red (polysaccharide)-positive material. This strain was extremely mucoid when grown in a liquid medium for enhancement of mucoid formation. Renal infections was present in some patients, as determined by the bladder washout test and by titers of antibody in serum, and antibody was present in the urine but not coating P. aeruginosa. We conclude that the mucoid layer interfered with antibody coating of the epidemic strain of P. aeruginosa.

Prepared endotracheal tubes (PETTs) are back-up airway equipment to be used in the case of a difficult intubation. A short PETT shelf life because of unknown safe storage time results in significant budget costs. This blinded, controlled study examined the pathogenic potential of PETTs in the operating room environment.

Eighty-one women were randomly selected for treatment with nalidixic acid (1 g four times a day) or cephalexin (500 mg four times a day) as therapy for 131 episodes of bacteriuria localized using the antibody-coated bacteria (ACB) test. Bladder infections were treated for three days and renal infections for 14 days. Rates of cure were not significantly different between treatment groups in each drug regimen. However, significantly more relapses occurred in the patients with ACB-positive infections treated for 14 days with cephalexin than in those treated for 14 days with nalidixic acid. More early reinfections occurred in the cephalexin-treated group after both three and 14 days of therapy. Resistance to nalidixic acid developed in the infecting bacteria in the urine during therapy with nalidixic acid in 3% of women after three days and in 16% of women after 14 days. Simultaneous resistance appeared in the urine, periurethral area, and fecal flora of these patients.