Drug-resistant Escherichia coli, Rural Idaho

Stool carriage of drug-resistant Escherichia coli in home-living residents of a rural community was examined. Carriage of nalidixic acid–resistant E. coli was associated with recent use of antimicrobial agents in the household. Household clustering of drug-resistant E. coli was observed. Most carriers of drug-resistant E. coli lacked conventional risk factors

Idiopathic Polymorphic Ventricular Tachycardia With Normal QT Interval in a Structurally Normal Heart

Polymorphic ventricular tachycardia (PVT) is a life-threatening arrhythmia that is typically related to long QT syndrome, organic heart disease, electrolyte abnormalities, cardiotoxic drugs, or adrenergic stimulation. A review of the literature reveals that PVT with normal QT interval and without underlying cause is quite rare. We report a case of idiopathic spontaneous PVT with structurally normal heart and without electrolyte abnormalities, drug reactions, or evidence of catecholamine induced arrhythmia. We also review the literature on the electrocardiographic characteristics and management of idiopathic PVT

Impact of Outpatient Antibiotic Use on Carriage of Ampicillin-Resistant Escherichia coli▿

Studies about the relationship between antibiotic consumption and carriage of antibiotic-resistant Escherichia coli in individual patients have yielded conflicting results. The goal of this study was to identify individual- and household-level factors associated with carriage of ampicillin (AMP)-resistant E. coli during consumption of a course of oral antibiotics. We enrolled outpatients and their families in a prospective household study of AMP-resistant or AMP-susceptible E. coli carriage. Two kinds of index patients were identified. Group 1 consisted of outpatients who were being initiated on a new antibiotic course at the time of a clinic visit, and group 2 consisted of outpatients not starting antibiotics. Each participant was asked to submit three stool swab samples (at baseline, week 1, and week 4) and to complete a questionnaire. Antimicrobial susceptibility testing was performed on each phenotypically distinct E. coli colony. The study included 149 group 1 households (total, 570 participants) and 38 group 2 households (total, 131 participants). AMP-resistant E. coli was recovered from 29% of stool samples. Observed associations with antibiotic exposure varied by drug class. Penicillins, which were the most frequently prescribed drug class, were associated with a modest increase in AMP-resistant E. coli carriage and a modest decrease in AMP-susceptible E. coli carriage. Neither change by itself was statistically significant. Macrolides were associated with reduced carriage of both AMP-resistant E. coli and AMP-susceptible E. coli (P < 0.05). Both AMP-resistant and AMP-susceptible E. coli demonstrated household clustering (P < 0.001). In summary, the overall effect of antibiotics on individual risk of carriage of AMP-resistant E. coli was small. However, even a modest alteration of the competitive balance between AMP-resistant and AMP-susceptible E. coli may promote population spread of resistant E. coli. Examining changes in both resistant and susceptible organisms in antibiotic-treated individuals and their close contacts improves understanding of antibiotic selection pressure

DISPATCHES Drug-resistant Escherichia coli, Rural Idaho

Stool carriage of drug-resistant Escherichia coli in home-living residents of a rural community was examined. Carriage of nalidixic acid–resistant E. coli was associated with recent use of antimicrobial agents in the household. Household clustering of drug-resistant E. coli was observed. Most carriers of drug-resistant E. coli lacked conventional risk factors. Acquisition of drug-resistant Escherichia coli may be influenced by food, exposure to flora of contacts, and use of antimicrobial agents (1–3). Few community studies have explored the contribution of these mechanisms to dissemination of drug-resistant E. coli in healthy persons (4–6). We examined epidemiologic factors associated with colonization by drug-resistant E. coli in home-living volunteers who were not recruited through healthcare settings (7,8). Resistance to trimethoprim/sulfamethoxazole (TMP/SMZ), nalidixic acid (NA), and extended-spectrum cephalosporins (ESCs) was examined (9,10). The Study From March to May 2002, a convenience sample of household volunteers was recruited from 1 rural community in Idaho. Consenting adults and parents of children completed an exposure questionnaire. The questionnaire assessed dietary history and livestock contact during the previous month, and other exposures, including antimicrobial drug use and travel outside the United States during the past 6 months. The study was reviewed and approved by the Western Institutional Review Board (Olympia, WA, USA). Information on antimicrobial drug prescriptions filled by community pharmacies in the preceding year was obtained (beginning March 2001). Pharmacy-documented antimicrobial drug prescriptions were compared with selfreported use. The definition of antimicrobial drug use was either pharmacy documentation of an antimicrobial dru

Molecular Analysis of Antimicrobial-Susceptible and -Resistant Escherichia coli from Retail Meats and Human Stool and Clinical Specimens in a Rural Community Setting

Background: Foodborne antimicrobial-resistant Escherichia coli may colonize and cause infections in humans, but definitive proof is elusive and supportive evidence is limited. Methods: Approximately contemporaneous antimicrobial-resistant (n=181) and antimicrobial-susceptible (n=159) E. coli isolates from retail meats and from human stool and clinical specimens from a single rural U.S. community were compared for polymerase chain reaction (PCR)-defined phylogenetic group (A, B1, B2, or D) and virulence genotype. Meat and human isolates from the same phylogenetic group with similar virulence profiles underwent sequential two-locus sequence analysis, random amplified polymorphic DNA (RAPD) analysis, and pulsed-field gel electrophoresis (PFGE) analysis. Results: According to phylogenetic distribution, resistant stool isolates were more similar to resistant meat isolates than to susceptible stool isolates. Overall, 19% of meat isolates satisfied molecular criteria for extraintestinal pathogenic E. coli (ExPEC). Nine sequence groups included meat and human isolates, and 17 of these 64 isolates demonstrated \u3e80% RAPD profile similarity to an isolate from the alternate source group (meat vs. human). However, PFGE profiles of the 17 isolates were unique, excepting two stool isolates from the same household. Conclusion: Nearly 20% of meat-source resistant E. coli represented ExPEC. The observed molecular similarity of certain meat and human-source E. coli isolates, including antimicrobial-resistant and potentially pathogenic strains, supports possible foodborne transmission