William D. Kobasa

Epidemiology of bacteriuria in an elderly ambulatory population

This study of bacteriuria in elderly (mean age 85 years, range 68 to 103) Jewish subjects of mostly middle and upper class attempted to determine disease prevalence, define the turnover in infected subjects, and assess the relation between functional status and infection. The prevalence of bacteriuria (midstream clean-catch method) was assessed in 373 women and 150 men. It was higher in women (18.2 percent) than in men (6.0 percent) (p less than 0.001) and was more common in functionally impaired nursing home residents (23.5 percent) than in apartment house dwellers (12.1 percent) (p less than 0.01). In longitudinal studies, 260 subjects (184 women and 76 men) had three urine culture surveys at six-month intervals. The cumulative percent infected on at least one survey was high (women 30.4 percent, men 10.5 percent). However, persistence of the same organism on all three surveys was surprisingly infrequent (women 6.0 percent, men 1.3 percent), and the turnover of infected and noninfected subjects was considerable. Persistence of bacteriuria on all three surveys was significantly more common in nursing home residents (13.9 percent) than in apartment house dwellers (3.1 percent) (p less than 0.01). Thus, bacteriuria is common in the elderly and appears related to functional status. However, the turnover of infected and noninfected subjects was high, and surprisingly, persistence was not found in most. The transient nature of bacteriuria in most provides support against the treatment of asymptomatic bacteriuria in the elderly.

A lack of association between bacteriuria and symptoms in the elderly

In a study of bacteriuria in elderly (mean age 85 years, range 69 to 101), mostly middle- and upper-class Jewish subjects, attempts were made to determine if bacteriuria without dysuria is otherwise asymptomatic. Seventy-two subjects (59 women and 13 men) without dysuria were questioned about other urinary symptoms (incontinence, frequency, urgency, suprapubic pain, flank pain, fever) and symptoms indicating a lack of well-being (anorexia, difficulty in falling asleep, difficulty in staying asleep, fatigue, malaise, weakness) when they were with and without bacteriuria. Twenty-two subjects had bacteriuria that resolved spontaneously; bacteriuria subsequently developed in 24 nonbacteriuric subjects; and 26 subjects had bacteriuria that resolved with antimicrobial therapy. Subjects occasionally reported urinary symptoms (especially incontinence) and commonly reported symptoms indicating a lack of well-being when they were with and/or without bacteriuria. However, no differences in symptoms were found when bacteriuric subjects were compared with themselves when they were nonbacteriuric. Thus, bacteriuria without dysuria in the elderly appears to be asymptomatic.

Bacteremia after Rectal Examination

Excerpt Transient bacteremia occurs after many manipulations or procedures involving trauma to mucosal surfaces with an indigenous microbial flora. Several investigators have studied the frequency ...

Effectiveness of Nafcillin, Methicillin, and Cephalothin in Experimental Staphylococcus aureus Endocarditis

Nafcillin, methicillin, and cephalothin (40 mg/kg every 6 h) were all effective in reducing the number of Staphylococcus aureus in vegetations in rabbits with endocarditis. Nafcillin and methicillin reduced the number of S. aureus at a significantly faster rate than did cephalothin. Nafcillin and methicillin also reduced titers of the S. aureus more rapidly than did cephalothin in vitro, both in broth and in rabbit serum.

Cefoperazone pharmacokinetics in normal subjects and patients with cirrhosis.

The pharmacokinetics of cefoperazone were studied and compared in six normal subjects and six patients with severe liver disease. All subjects received a 2-g intravenous infusion of cefoperazone over 15 min. Significantly different results were noted between normal subjects and patients with cirrhosis (range [mean]) for the following: peak serum concentrations (203 to 345 [239] versus 82 to 206 [141] micrograms/ml; P less than 0.01); serum beta half-lives (1.0 to 1.8 [1.5] versus 2.3 to 9.9 [4.5] h; P less than 0.05); renal excretion (17 to 27 [21] versus 32 to 60 [50]%; P less than 0.01); and apparent volumes of distribution at steady state (4.1 to 7.8 [6.3] versus 12.7 to 23.8 [15.9] liters/1.73 m2; P less than 0.01). Lower peak serum levels in the patients with cirrhosis were probably related to an increased apparent volume of distribution secondary to ascites and to decreased serum protein binding of cefoperazone. Longer beta half-lives in the patients with cirrhosis were probably secondary to both decreased hepatic excretion caused by severe liver disease and to increased apparent volume of distribution. However, the longest beta half-life among the patients with cirrhosis was in a subject with a serum creatinine level of 2.1 mg/dl. We conclude that, although mild to moderate impairment of cefoperazone excretion occurs in patients with hepatic disease, adjustment of dosage may be necessary only with concomitant renal insufficiency.

Susceptibilities of anaerobic bacteria to cefoperazone and other antibiotics.

Two hundred fifty clinical isolates of anaerobic bacteria were tested for suceptibility to cefoperazone, cefamandole, cefoxitin, carbenicillin, clindamycin, and chloramphenicol. Anaerobic gram-positive cocci were susceptible to all of the antibiotics tested. Clindamycin was the most active agent against Bacteroides species, followed by chloramphenicol and then cefoxitin. Cefoperazone was less active than cefoxitin and equal in activity to carbenicillin. Cefamandole was the least active antibiotic against Bacteroides. B. distasonis, B. vulgatus, B. thetaiotaomicron, and B. ovatus were more resistant to the antibiotics than B. melaninogenicus, B. oralis, or B. bivius. Clindamycin was the most active agent against Clostridium species, followed by chloramphenicol; the three cephalosporins and carbenicillin were about equal in activity. Clindamycin was the most active antibiotic against Fusobacterium species, followed by chloramphenicol, carbenicillin, and cefoperazone (which were about equally active) and then cefamandole.

Enoxacin compared with vancomycin for the treatment of experimental methicillin-resistant Staphylococcus aureus endocarditis.

Enoxacin administered orally was compared with vancomycin administered intravenously for the treatment of experimental methicillin-resistant Staphylococcus aureus endocarditis. The MICs and MBCs of both enoxacin and vancomycin for an inoculum of 5.0 X 10(5) CFU of the methicillin-resistant S. aureus strain per ml were 1.56 microgram/ml. With an inoculum of 10(8) CFU/ml, enoxacin at 6 micrograms/ml and vancomycin at 180 micrograms/ml resulted in similar decreases in numbers of methicillin-resistant S. aureus in broth. Methicillin-resistant S. aureus endocarditis in rabbits was treated with enoxacin at 100 mg/kg orally every 12 h or vancomycin at 30 mg/kg intravenously every 12 h for 3 or 5 days. Enoxacin treatment for 3 or 5 days and vancomycin treatment for 5 days significantly reduced bacterial counts of vegetations compared with those in untreated control rabbits after 1 day of infection. Bacterial counts of vegetations after vancomycin treatment for 3 days did not differ significantly from those of untreated controls. Bacterial counts of vegetations in the four therapeutic groups did not differ significantly from one another. In uninfected rabbits single doses of vancomycin at 30 mg/kg administered intravenously achieved much higher concentrations in serum than did single doses of enoxacin at 100 mg/kg administered orally. Enoxacin had an elimination half-life in serum that was approximately 1.5 times longer than that of vancomycin. This study demonstrated that enoxacin administered orally is as effective as vancomycin administered intravenously for the treatment of experimental methicillin-resistant S. aureus endocarditis.

Treatment of Experimental Staphylococcus aureus Abscesses: Comparison of Cefazolin, Cephalothin, Cefoxitin, and Cefamandole

Cefazolin (CZ), cephalothin (CF), cefoxitin (CX), and cefamandole (CM) were evaluated in therapy of Staphylococcus aureus infection produced in perforated table tennis balls placed intraperitoneally in rabbits. Four weeks after placement of two balls in each rabbit, a beta-lactamase producing strain of S. aureus was injected into one of the balls. Twenty-four hours later therapy was initiated with 40 mg of CZ or 80 mg of CF, CX, or CM per kg intramuscularly every 6 h. After 24 h of treatment, the mean log10 colony-forming units per ml were 7.1 for CZ, 6.7 for CF, 6.5 for CX, and 7.2 for CM. After 72 h the mean log10 colony-forming units per ml were 5.0 for CZ, 4.1 for CF, 3.6 for CX, and 5.6 for CM. After 8 days, the titers were 1.6/ml for CZ, 1.0 for CF, 1.9 for CX, and 3.6 for CM. CZ serum levels were about double CF and CX levels and about two-thirds of CM levels. In sterile ball fluid CZ and CM levels were more than double CF or CX concentrations. Concentrations of all four antibiotics were lower in infected balls.

Comparison of difloxacin, enoxacin, and cefazolin for the treatment of experimental Staphylococcus aureus endocarditis.

This study compared difloxacin administered orally, enoxacin administered orally, and cefazolin administered intramuscularly for the treatment of experimental Staphylococcus aureus endocarditis. Difloxacin significantly reduced bacterial counts of vegetations compared with enoxacin. This study demonstrated that difloxacin was significantly more effective than enoxacin and as effective as cefazolin for the treatment of S. aureus endocarditis in rabbits.

Enoxacin compared with cefoperazone for the treatment of experimental Enterobacter aerogenes endocarditis.

This study compared enoxacin administered orally with cefoperazone administered intramuscularly for the treatment of Enterobacter aerogenes endocarditis in rabbits. The MICs and MBCs of both enoxacin and cefoperazone for an inoculum of 10(5) CFU/ml of the E. aerogenes strain used were 0.8 micrograms/ml, respectively. With an inoculum of 10(8) organisms per ml, enoxacin at 2 and 5 micrograms/ml and cefoperazone at 60 and 155 micrograms/ml were effective in reducing titers of E. aerogenes in broth. E. aerogenes endocarditis in rabbits was treated with enoxacin (100 or 25 mg/kg orally every 6 h) or cefoperazone (60 mg/kg intramuscularly every 6 h) for 5 or 10 days. Enoxacin at 100 and 25 mg/kg significantly reduced bacterial titers of vegetations compared with those of untreated controls. Enoxacin at 100 mg/kg was significantly more effective than enoxacin at 25 mg/kg and cefoperazone. Enoxacin at 25 mg/kg and cefoperazone did not differ significantly. Cefoperazone and controls did not differ significantly. In uninfected rabbits single doses of cefoperazone achieved much higher concentrations in serum than single doses of enoxacin (25 and 100 mg/kg). The half-lives of enoxacin at 25 and 100 mg/kg were approximately three times longer than that of cefoperazone.