Conventional and molecular epidemiology of trimethoprim-sulfamethoxazole resistance among urinary Escherichia coli isolates.

BACKGROUND: Antibiotic resistance is increasing in Escherichia coli, the most common cause of urinary tract infections, but its epidemiology has not been well described. We evaluated the epidemiology of trimethoprim-sulfamethoxazole-resistant E. coli in a large, public health care system in Denver, Colorado. METHODS: Outpatients with E. coli urinary tract infections during the first 6 months of 1998 were evaluated retrospectively. A prospective study was then performed to confirm the rate of trimethoprim-sulfamethoxazole resistance. We used several strain-typing methods (pulsed-field gel electrophoresis, ribotyping, serotyping) to evaluate the molecular epidemiology of the resistance. RESULTS: The rate of trimethoprim-sulfamethoxazole resistance was similar in the retrospective (24% [161/681]) and prospective (23% [30/130]) phases of the study (P = 0.89). Almost all trimethoprim-sulfamethoxazole-resistant strains (98%) were resistant to at least one other antibiotic. Risk factors for infection with a resistant strain included age < or =3 years, Hispanic ethnicity, recent travel outside the United States, and a prior urinary tract infection. However, rates of resistance were >15% among nearly all of the subgroups. Most strains had high-level resistance (>1000 microg/mL) to trimethoprim-sulfamethoxazole. Of the 23 resistant isolates evaluated, 10 (43%) belonged to the clone A group. There was no correlation between conventional epidemiologic characteristics and the molecular mechanism of resistance or strain type. CONCLUSION: Resistance to trimethoprim-sulfamethoxazole among E. coli isolates among patients in a Denver public health care system is common, with high rates of resistance even among patients without risk factors.

Defibrillation and thrombolysis following a myocardial infarct in Antarctica.

This report describes the cardiac resuscitation and air evacuation of a 53-yr-old male dentist who sustained an inferior myocardial infarction and cardiac arrest in Antarctica. Following defibrillation and thrombolysis, a ski-equipped LC-130 airlifted this critical patient 9 h north to New Zealand for angioplasty. This case heralds the rapidly evolving ability to extend state-of-the-art health care to previously inaccessible areas. While increased public confidence is warranted and welcomed, the authors aim to temper unchecked enthusiasm by detailing both the technical complexities and the good fortune involved in this extreme resuscitation. A literature review suggests this case represents the most geographically remote cardiac resuscitation yet described.