Consultation in university-based and community-based infectious disease practices: a prospective study.

Infectious disease physicians in university and community practices completed a standard data form following each of 1,366 inpatient consultations during a 7-month period. The rate of consultation was higher in the university practice than in the community practice (3.4 vs. 1.8 per 100 discharges, respectively). Known or suspected bacterial pathogens accounted for more than half of all consultations in both practice groups. The three organ systems most commonly affected by infection were pulmonary (20% in university practice vs. 19% in community practice), skin and soft tissue (13% in university practice vs. 20% in community practice), and musculoskeletal (12% in university practice vs. 16% in community practice). Bloodstream infection, pneumonia, unexplained fever, osteomyelitis, urinary tract infection, and cellulitis were the six most common disease processes that led to consultation in both practice groups. The percentage of patients with noninfectious diseases and the percentage for whom a change in antimicrobial therapy was advised was nearly identical in both practice settings. Physicians in private practice performed more consultations on weekends (20% vs. 11% in university practices, P < .001) and between 6:00 P.M. and 7:00 A.M. (15% vs. 6% in university practices, P < .001). The scope and diversity of the work of consultants in community practices are nearly identical to those of their colleagues in university-based practices.

Cryptococcal ventricular-peritoneal shunt infection: clinical and epidemiological evaluation of two closely associated cases.

OBJECTIVE: To determine the cause of meningitis associated with Cryptococcus neoformans in two patients with recent ventricular-peritoneal (VP) shunt placement. DESIGN: A retrospective review of materials, records, and concurrent cases of VP shunt procedures. Isolates of C neoformans from each patient were submitted for analysis by colony morphology, biochemical testing, and karyotyping by pulsed-field electrophoresis. SETTING: Two 400-bed community hospitals. PATIENTS: Two immunocompetent patients presented with symptoms of progressive hydrocephalus in August 1991. Each received a VP shunt on the same day by the same surgeon using materials from a common vendor and hospital. RESULTS: Both patients presented within six to eight weeks with symptoms of fever, headache, rash, and cultures of cerebrospinal fluid (CSF) that yielded C neoformans. Each patient recovered after therapy with amphotericin B and flucytosine followed by several months of fluconazole, although one required replacement of the VP shunt for cure. Review of each patient's history and CSF characteristics at the time of shunt placement suggested reactivation of a preexisting infection. Isolates of C neoformans from each patient were submitted for analysis by colony morphology, biochemical testing, and karyotyping by pulsed-field electrophoresis. Each isolate was found to be unique by chromosomal karyotyping. CONCLUSIONS: Our data and previous reports suggest that cryptococcal VP shunt infections appear to be a complication of shunts placed in previously infected persons rather than nosocomial transmission of cryptococcus during placement.

Efficacy of antibiotic combinations including rifampin against methicillin-resistant Staphylococcus epidermidis: in vitro and in vivo studies.

Rifampin in combination with other antibiotics has been used successfully in the treatment of serious infections due to Staphylococcus epidermidis. The authors evaluated the efficacy of rifampin in combination with either cephalothin, nafcillin, gentamicin, or vancomycin to determine in vitro synergistic or antagonistic interactions of the combinations and to determine the role of the second antibiotic in preventing the emergence of rifampin-resistant mutants. The authors found that among 10 isolates of methicillin-resistant S. epidermidis, synergy was found in checkerboard studies (inoculum, 10(5) colony-forming units/ml) for only two isolates and only with nafcillin and rifampin; antagonism was present with one combination for each of four different isolates. Time-kill studies showed each antibiotic capable of preventing the emergence of rifampin-resistant mutants for all 10 isolates, but no synergy or antagonism was present. In experimental endocarditis, however, the addition of cephalothin did not prevent the emergence of rifampin-resistant mutants, and rifampin-resistant mutants were as capable of causing endocarditis as were their rifampin-sensitive parents. Thus, rifampin was a bactericidal antibiotic against methicillin-resistant S. epidermidis. The benefit of a second antibiotic in vitro was the prevention of the emergence of rifampin-resistant mutants. However, in vivo results with a beta-lactam antibiotic did not confirm in vitro observations. More animal and human studies should be performed with antibiotic combinations including rifampin against methicillin-resistant S. epidermidis.

Rifampin therapy of Staphylococcus epidermidis. Use in infections from indwelling artificial devices.

Rifampin was added to existing antibiotic regimens in two patients with Staphylococcus epidermidis infections; one patient had prosthetic valve endocarditis and the other had an infection of a CSF shunt. The addition of rifampin increased serum or CSF bactericidal titers 16-fold or greater and was correlated with a favorable clinical response. The results of tests for tube-dilution antibiotic susceptibility showed rifampin to be the most active of all antibiotics tested against the patients' organisms. The combinations of gentamicin sulfate, nafcillin sodium, or vancomycin hydrochloride with rifampin prevented the emergence of rifampin resistance in vitro and promoted enhanced killing when compared with either antibiotic alone.