Clinical spectrum of Pseudomonas putida infection

The clinical and microbiologic characteristics of 55 cases of Pseudomonas putida infection in 53 patients in a medical center in Taiwan from April 1988 to March 1993 are reported. P. putida was cultured in the decreasing order of frequency from urine (24 isolates), sputum (12), blood (10), wound discharge (3), peritoneal fluid (3), cerebrospinal fluid (2) and umbilical swab (1). Of the adult patients, 23% (12/53) were considered to be contaminated or colonized with P. putida. Of the 41 patients with manifest disease. 17 (41%) had urinary tract infections, 10 (24%) had pneumonia, 8 (19%) had septicemia, 3 (7%) had wound infections, 2 (5%) had meningitis and 1 (2%) had peritonitis. Of these, 55% were nosocomial infections. The case fatality rate was 29% (12/41). There was no significant correlation between patient mortality and the type of disease caused by the bacterium. Results of in vitro susceptibility tests suggested that imipenem and ceftazidime were more effective than other antimicrobials. This study indicates that the clinical spectrum of diseases caused by P. putida is broader and the incidence of true infection is higher than previously expected, especially among hospitalized patients who undergo invasive procedures such as placement of intravascular devices, urinary catheterization and intubation.