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Newer beta-lactam antibiotics with high levels of activity against gram-negative aerobic bacilli (including Pseudomonas aeruginosa) such as cefoperazone, ceftazidime, imipenem, and aztreonam may be suitable for monotherapy of gram-negative pneumonia. Aminoglycoside antibiotics (gentamicin, tobramycin, amikacin are also highly active against these same organisms and have been more extensively used, but are both ototoxic and nephrotoxic. Key therapeutic questions are whether beta-lactams can safely replace aminoglycosides for the treatment of gram-negative pneumonia, and whether monotherapy or aminoglycoside and beta-lactam combination antibiotic treatment is superior. There is remarkably little definitive clinical data in the literature to answer these questions, but available studies suggest that beta-lactam monotherapy may be adequate for Escherichia coli and Klebsiella pneumoniae pneumonias, but that combination therapy may be preferred for Pseudomonas aeruginosa, Serratia sp, Enterobacter sp, and Acinetobacter sp, largely based on rates of bacterial persistence and emergence of resistance. At this time, there are more data available to support aminoglycoside monotherapy than beta-lactam monotherapy in gram-negative pneumonia and remarkably little data to suggest superiority of two antibiotics over single agents when they have been compared prospectively. Thus, combination therapy remains a conservative recommendation until better studies are available.

The role of antimicrobials in the treatment of bronchitis remains controversial. Antimicrobials are rarely indicated in acute bronchitis. Antimicrobials are indicated in a subset of patients with acute exacerbations of chronic bronchitis. The efficacy of an antimicrobial agent in bronchitis can be estimated by the ratio of the sputum concentration of the antimicrobial to its in vitro activity against common respiratory pathogens (S/M90). These S/M90 rates are presented in tabular form. However, given the lack of solid data to support antimicrobial treatment for most episodes of bronchitis, use of the S/M90 to select antimicrobial therapy remains theoretical rather than of proven clinical benefit.

Two patients with spontaneous Pasteurella multocida peritonitis in association with cirrhosis and ascites are described. Both patients had close contact with domestic animals, but neither had been bitten. Both patients died, but only one as a result of his infection. We are aware of only one previous report of cirrhosis with spontaneous peritonitis caused by this organism. P. multocida should be considered as a possible cause of peritonitis in cirrhotic patients with a history of close contact with animals, particularly cats.

Pulmonary infection with Sporothrix schenckii is extremely rare. The small number of reported cases and lack of comparative clinical trials make assessment of treatment regimens difficult. Three modalities should be considered: Saturated solution of potassium iodide (SSKI), amphotericin B, and resective surgery. Available data suggest that SSKI is unlikely to be successful in cavitary disease or disease in immunocompromised hosts. Amphotericin B alone has been successfully used to cure cavitary pulmonary sporotrichosis, but overall cure rates probably are no higher than 50%, and the probability of cure in bilateral apical disease is dismal. Surgical resection has been successful when used alone in a small number of cases. The highest cure rates (70% to 80%) appear to be a result of management with amphotericin B or SSKI combined with resective pulmonary surgery. The dosage and duration of amphotericin B or SSKI to be used in conjunction with surgical resection is unknown.

Several alternative schedules of cleaning and disinfection of flexible fiberoptic endoscopes were evaluated during actual use in paired endoscopy suites. Thorough mechanical cleaning with detergent and alcohol was compared with the same cleaning with the addition of 5-, 10-, or 20-min immersion of the endoscope insertion tube in 2% alkaline glutaraldehyde solution. Endoscopes were cultured quantitatively and qualitatively for aerobic bacteria at three different times relative to procedures: after use, immediately after cleaning alone or cleaning plus disinfection, and after storage unused in a cabinet for 20-72 h. Cleaning plus glutaraldehyde immersion for 5 min significantly reduced bacterial contamination both immediately and after storage when compared with cleaning alone. Results of cleaning plus 10- and 20-min glutaraldehyde immersion were not statistically different from cleaning plus 5-min glutaraldehyde immersion. The addition of forced-air drying following disinfection significantly reduced bacterial contamination following storage when compared with storage without previous drying. Cleaning plus brief (5-20 min) glutaraldehyde immersion significantly reduced bacterial contamination of endoscopes when compared with cleaning alone (p less than 0.001) and, when combined with forced-air drying before storage, resulted in 59/63 (94%) negative endoscope cultures by the methods used in this study. These measures do not ensure sterility, but are superior to mechanical cleaning alone and sufficiently practical to be used routinely without undue interruption of busy endoscopy schedules.

Pseudomonas aeruginosa was present in bile cultures from 10 patients who had undergone previous endoscopic retrograde cholangiopancreatography in 1984. After environmental cultures and review of instrument disinfection, we traced the infections to a single endoscope contaminated with P. aeruginosa, serotype 10. Although the instrument had been cleaned repeatedly with an automatic endoscope cleaning machine, P. aeruginosa survived on residual moisture left in the channels of the endoscope. Contamination ended only after we began to manually suction alcohol through the endoscope before air drying. In 5 of 10 patients, P. aeruginosa caused clinical infections including gangrenous cholecystitis, abscesses, and death. We could identify no factor that distinguished symptomatic from asymptomatic patients. In asymptomatic patients, P. aeruginosa was recovered from gallbladder bile up to 2 mo after endoscopic retrograde cholangiopancreatography. As this P. aeruginosa epidemic was discovered retrospectively because we monitor bile cultures, we advocate this practice as part of endoscopic retrograde cholangiopancreatography procedures.