Frank M. Calia

A Double-Blind Study of Trimethoprim-Sulfamethoxazole Prophylaxis in Patients Having Transrectal Needle Biopsy of the Prostate

We studied 89 men undergoing transrectal prostatic biopsies to determine the efficacy of trimethoprim-sulfamethoxazole in preventing postoperative fever, bacteremia and bacteriuria. Of the patients who received placebo temperatures of 37.6C or more occurred in 18%, bacteremia in 70% and bacteriuria in 21%. Most cases of bacteremia were caused by anaerobic organisms and were asymptomatic. Trimethoprim-sulfamethoxazole did not reduce the frequency of fever or bacteremia but did produce a significant reduction in bacteriuria (0 versus 21%, p equals 0.008).

Comparative Activity of Tobramycin, Amikacin, and Gentamicin Alone and with Carbenicillin Against Pseudomonas aeruginosa

The effect of gentamicin against 130 clinical isolates of Pseudomonas aeruginosa was compared with that of two investigational aminoglycoside antibiotics, tobramycin and amikacin. Minimal inhibitory concentration data indicated that, on a weight basis, tobramycin was two to four times as active as gentamicin against most isolates. However, 14 of 18 organisms highly resistant to gentamicin (≥80 μg/ml) were also highly resistant to tobramycin. Amikacin was the least active aminoglycoside on a weight basis, but none of the isolates were highly resistant to this antibiotic. When therapeutically achievable concentrations were used, adding carbenicillin to gentamicin or to tobramycin enhanced inhibitory activity against those isolates susceptible (≤5 μg/ml) or moderately resistant (10 to 40 μg/ml) to the aminoglycoside. Such synergy was seldom demonstrated for isolates highly resistant to gentamicin or tobramycin. The combination of carbenicillin and amikacin enhanced inhibition against all but two of the isolates. Both tobramycin and amikacin offer in vitro advantages over gentamicin against P. aeruginosa.

BL-P1654, Ticarcillin, and Carbenicillin: In Vitro Comparison Alone and in Combination with Gentamicin Against Pseudomonas aeruginosa

Minimum inhibitory concentrations of carbenicillin, ticarcillin, and BL-P1654 were determined for 89 clinical isolates of Pseudomonas aeruginosa. Ticarcillin was generally twice as active and BL-P1654 eight to 16 times as active as carbenicillin. Usually carbenicillin and ticarcillin killed at the same concentration or twice the concentration needed to inhibit, whereas 400 μg of BL-P1654 per ml was not bactericidal for the majority of isolates tested. The inhibitory effect of all three drugs varied markedly with the size of bacterial inoculum. When therapeutically achievable concentrations were used, adding gentamicin enhanced the inhibitory and bactericidal activity of all three penicillin derivatives for the majority of isolates. However, inhibition of isolates highly resistant to gentamicin was not improved by combining the semisynthetic penicillins with gentamicin.

Serum Antibiotic Concentrations Pre- and Postcardiopulmonary Bypass

Serum concentrations of cephalothin or kanamycin, or both, were determined in 53 patients undergoing cardiopulmonary bypass. Conventional doses of these antibiotics did not provide serum levels above the accepted minimum inhibitory concentrations in children. Adults had adequate serum antibiotic concentrations only when the antimicrobials were administered within 4 h of beginning cardiopulmonary bypass. The impact of these variations upon the occurrence of infectious endocarditis could not be appraised since no cases of infective endocarditis were seen during a 4-month postoperative period.

Anaerobic Bacteriuria in a Male Urologic Outpatient Population

We screened 517 urine samples from male outpatients, many of whom had underlying urinary tract pathology, for anaerobic and aerobic bacteriuria. Of the 153 specimens containing greater than 10(5) bacteria per ml. 20% yielded anaerobes only and an additional 6% revealed mixed anaerobic and aerobic growth. Pyuria was found more frequently in samples containing anaerobic bacteriuria than in those containing no growth but not as frequently as when aerobic bacteria were present. The high counts of anaerobic bacteria in first-voided specimens compared to midstream and post-prostatic massage aliquots suggested a urethral source for most bacteria. However, suprapubic aspiration of bladder urine demonstrated the organism in 2 of 10 patients with high numbers of anaerobes and pyuria in voided samples.

The effect of lactinex on rabbit ileal loop reactions induced by enterotoxigenicEscherichia coli

The effect of Lactinex, a lactobacillus-containing pharmaceutical, on rabbit ileal loop reactions induced by enterotoxigenicEscherichia coli was studied. Lactinex granules, tablets, or its separate components were mixed and incubated in vitro with toxigenicE. coli prior to injection into ileal loops. Since inocula were free of preformed enterotoxin, reactions indicated in vivo enterotoxin production. Lactinex granules reduced loop fluid when compared with that induced by the positive control (P<0.001) or inocular containing Lactinex tablets (P=0.009). Whey powder, 109 and 107Lactobacillus acidophilus, and 108Lactobacillus bulgaricus were the only Lactinex components that significantly reduced loop fluid.

Pirbenicillin: Comparison with Carbenicillin and BL-P1654, Alone and with Gentamicin, Against Pseudomonas aeruginosa

Minimum inhibitory concentrations (MIC) of pirbenicillin against 135 clinical isolates of Pseudomonas aeruginosa were one-fourth of those required for carbenicillin but two times higher than those for BL-P1654. Increasing the inoculum size produced an adverse effect on the bactericidal activity for all three antibiotics. This was more apparent for pirbenicillin than for carbenicillin, but less than the effect on BL-P1654. When concentrations of antibiotics likely to be achieved clinically were used, gentamicin increased the inhibitory and bactericidal effects of all three semisynthetic penicillins for the majority of isolates. Strains highly resistant to the aminoglycoside antibiotic, however, were inhibited no more by the penicillin-gentamicin combinations than by the most effective of the antibiotics alone.