Enterococcus: an old pathogen with new tricks.

Recent clinical enterococcal isolates from the Oklahoma City Department of Veterans Affairs Medical Center were screened for high-level aminoglycoside resistance, vancomycin resistance, beta-lactamase production, and hemolysin production. Twenty-nine of 53 (55%) enterococcal isolates had high-level resistance to gentamicin, kanamycin, or streptomycin; 27 of these isolates were from the blood and 16 (59%) showed high-level gentamicin resistance. Twenty-one percent of 259 enterococcal isolates from blood, urine, stool, and other sources were hemolytic. Of thirteen blood isolates tested for both high-level gentamicin resistance and hemolysin production, 6 (46%) showed both characteristics. Vancomycin-resistant or beta-lactamase-producing isolates were not found. Nineteen of 21 charts from patients with premortem enterococcal blood isolates were reviewed, and no correlation was found between appropriate antibiotic treatment for high-level gentamicin-resistant or susceptible enterococcal bacteremia and outcome. Enterococci with multiple high-level aminoglycoside resistance, but not vancomycin resistance or beta-lactamase production, are common at this referral medical center. Clinical microbiology laboratories in Oklahoma should routinely screen enterococcal isolates causing potentially serious infections (eg, from blood or cerebral spinal fluid) for high-level aminoglycoside resistance.

Clinical experience with HIV-infected patients at the University of Oklahoma Health Sciences Center.

Two hundred seventy-two patients infected with human immunodeficiency virus (HIV) have received care from the members of the adult infectious disease section at the University of Oklahoma Health Sciences Center. The majority of these patients met the diagnostic criteria for acquired immunodeficiency syndrome. This group of patients was characterized by relatively few parenteral drug abusers, a high incidence of disseminated histoplasmosis, and an unexpectedly low frequency of toxoplasmosis. The prevalence of risk behaviors and endemic disease may be responsible for these particular case distributions.

Clinical experience with HIV-infected patients at the University of Oklahoma Health Sciences Center: an update.

We reviewed the course of 545 human immunodeficiency virus (HIV)-infected patients seen between 1983 and March 30, 1991. A majority were Caucasian homosexual or bisexual men, while parenteral drug abusers represented a smaller proportion than seen nationwide. In the 274 patients with the acquired immunodeficiency syndrome (AIDS), the distribution of AIDS-defining conditions was generally consistent with those reported in studies from elsewhere in the United States. However, toxoplasmosis remained relatively uncommon. There was a slightly higher incidence of disseminated histoplasmosis compared to other studies. HIV encephalopathy (AIDS dementia) was likely underdiagnosed. Although data suggested prolongation of the asymptomatic phase of HIV infection, median survival after AIDS diagnosis remained approximately 12 months.

Relapsing pneumococcal bacteremia in immunocompromised patients.

Relapse of Streptococcus pneumoniae bacteremia after appropriate therapy is thought to be rare, even in immunocompromised patients. We describe three immunodeficient patients who experienced repeated episodes of pneumococcal bacteremia within 8 weeks after receiving appropriate therapy. Serotyping and DNA fingerprinting of respective isolates strongly suggested that each patient's bacteremic relapse was caused by the same pneumococcal strain. Relapsing and recurrent infections with an identical pneumococcal strain, especially in immunodeficient individuals, may be more common than is generally appreciated.

Invasive pneumococcal disease in central Oklahoma: emergence of high-level penicillin resistance and multiple antibiotic resistance. Pneumococcus Study Group.

Relatively penicillin-resistant pneumococci have caused 10% of invasive pneumococcal disease in central Oklahoma during the last decade, but almost no high-level penicillin or other antibiotic resistance has been described. This study evaluated antibiotic susceptibility and serotype distribution in invasive pneumococcal disease in the Oklahoma City metropolitan area (1990 population 848,000). A total of 144 cases of invasive infection was collected in 1 year (17 with meningitis, 120 with other bacteremic infections, and 7 with other invasive infections), for a rate of 16.9/100,000 (95% confidence interval [CI], 14.0-19.5). For the population aged > or = 60, invasive pneumococcal disease rates were higher among nursing home residents (352/100,000) than among nonresidents (25.6/100,000; relative risk, 13.7; 95% CI, 7.7-24.7). Antibiotic-resistant organisms caused 19.4% of the cases: relative penicillin resistance, 7.6%; high-level penicillin resistance, 1.4% (2 cases), and 11% resistance to erythromycin, trimethoprim-sulfamethoxazole, or both, with 5% sharing both resistances plus a MIC of penicillin of 0.06 microgram/mL.