John-Erik Brorson

Efficacy of long-term antimicrobial prophylaxis after acute pyelonephritis in Pregnancy

The efficacy of antimicrobial prophylaxis for recurrent urinary infection after an episode of acute febrile pyelonephritis was assessed in 27 pregnant women. Immediately following a 2-week treatment course for acute pyelonephritis, low-dose prophylaxis with a proper antimicrobial agent taken at bedtime daily was continued until 1 month after delivery. 23 women received 50 mg of nitrofurantoin, and 2 each were given 250 mg of amoxycillin and 250 mg of cephalexin, respectively. The treatment regimens were well tolerated and there were no breakthrough infections during a total of 7.8 patient-years of treatment. These results show that long-term low-dose antimicrobial prophylaxis is highly effective in this population at high risk of recurrent acute pyelonephritis.

Comparison Between Agar and Broth Minimum Inhibitory Concentrations of Cefamandole, Cefoxitin, and Cefuroxime

The in vitro susceptibility to cefamandole, cefoxitin, and cefuroxime of clinical isolates of Streptococcus faecalis, Klebsiella, and indole-positive Proteus was assayed using minimum inhibitory concentration (MIC) determinations in broth and on solid media. It could be demonstrated that the agar dilution MICs obtained when S. faecalis was tested against cefuroxime and when indole-positive Proteus strains were tested against cefamandole tended to be considerably lower than those obtained with the broth dilution technique. The Klebsiella strains tested did not show any major differences with regard to MICs in broth or on solid media. Using an animal experimental infection model it could be demonstrated that with indole-positive Proteus the higher broth MIC correlated better to the observed data than the lower agar MIC when a β-lactamase-producing strain was tested. The data obtained indicated that the β-lactamase of the indole-positive Proteus strain was inducible. The results of the study gave evidence for a risk of false susceptibility of some bacterial species against cefamandole when agar techniques, e.g. paper disk diffusion, are used. For cefuroxime, the same phenomenon can be expected with S. faecalis and to some extent with indole-positive Proteus. In this study, cefoxitin seemed considerably less affected by the technique used for susceptibility testing.

The Regression Line for Erythromycin is Not Valid for Beta-hemolytic Streptococci Group A

The antibacterial activity of erythromycin to 50 beta-hemolytic streptococci group A was assessed using disc diffusion and MIC techniques on solid media at pHs 6, 7 and 8 in CO2, aerobic and anaerobic atmospheres. The majority of the strains were only intermediately sensitive to erythromycin according to the disc diffusion method, whereas they were sensitive as judged by the MIC determination. This demonstrates that the regression line is invalid for the drug-bug combination of erythromycin and beta-hemolytic streptococci group A. It was also shown that the activity of erythromycin is reduced at a lower pH and in CO2 incubation.

Culture from epipharynx of little value in bacterial pneumonia

In 75 patients with acute pneumonia of moderate severity a comparative study between transtracheal aspiration (TTA), sputum culture and epipharynx culture was carried out. Organisms considered as the probable etiological agent were found in 53% with TTA. The same organisms were found in only 27% in sputum samples and in 21% in epipharynx samples. No serious complications with TTA was noted.

Clinical evaluation of lysis-centrifugation technique and a biphasic bottle system for blood culture.

The lysis centrifugation technique (Isolator, DuPont) for blood culture was compared with a system with biphasic medium in bottles. The Isolator was filled with 10 ml of blood once. One aerobic and one anaerobic bottle were injected 3 times with 2.5 ml of blood each. Organisms were detected in 90/748 blood cultures; 26 of which were contaminants. 34 pathogens were detected by both methods, 12 with the Isolator only and 18 with the 3 bottle pairs only. The first pair of bottles revealed 45/52 isolates, the second and third pairs gave an additional 6 and 1 isolate respectively. The contamination rate was 2.3% for the Isolator, which is lower than earlier reported, and 1.3% for the bottles. The most common pathogens were Escherichia coli, Pseudomonas aeruginosa and Streptococcus pneumoniae. The Isolator gave a faster diagnosis in 23 of the 34 cases. No decrease in the recovery rate was seen after 8 h, the longest recommended transport time for the Isolator tubes. One Isolator gave the same yield as the first pair of bottles and combining the methods increased the yield 25% compared to either method alone.

Isolation of L-Forms Reverting to Staphylococcus Aureus from Pus of Patients with Staphylococcal Infections: A Study on 31 Cases of Staphylococcal Infections Treated with Antibiotics

Abstract The results of regularly performed cultures with the aim of isolating L-forms from pus from 31 patients treated with antibiotics for staphylococcal infections are presented. In 3 cases growth of L-forms of Staphylococcus aureus was obtained on penicillin-free media. These patients had not been treated with cell wall affecting antibiotics for 2 weeks or more prior to the isolation of Informs.