Long-term use of selective decontamination of the digestive tract does not increase antibiotic resistance: a 5-year prospective cohort study.

PURPOSE: Despite the evidence, the use of selective decontamination of the digestive tract (SDD) remains controversial, largely because of concerns that it may promote the emergence of antibiotic-resistant strains. The purpose of this study was to evaluate the long-term incidence of carriage of antibiotic-resistant bacteria (ARB), its clinical impact on developing infections and to explore risk factors of acquiring resistance. METHODS: This study was conducted in one 18-bed medical-surgical intensive care unit (ICU). All consecutive patients admitted to the ICU who were expected to require tracheal intubation for longer than 48 h were given a 4-day course of intravenous cefotaxime, and enteral polymyxin E, tobramycin, amphotericin B in an oropharyngeal paste and digestive solution. Oropharyngeal and rectal swabs were obtained on admission and once a week. Diagnostic samples were obtained on clinical indication. RESULTS: During 5 years 1,588 patients were included in the study. The incidence density of ARB was stable: 18.91 carriers per 1,000 patient-days. The incidence of resistant Enterobacteriaceae was stable; the resistance of Pseudomonas aeruginosa to tobramycin, amikacin and ciprofloxacin was strongly reduced; there was an increase of P. aeruginosa resistant to ceftazidime and imipenem, associated with the increase in imipenem consumption; the incidence of other nonfermenter bacilli and oxacillin-resistant Staphylococcus aureus was close to zero. Ninety-seven patients developed 101 infections caused by ARB: 23 pneumonias, 20 bloodstream infections and 58 urinary tract infections. Abdominal surgery was the only risk factor associated with ARB acquisition [risk ratio 1.56 (1.10-2.19)]. CONCLUSIONS: Long-term use of SDD is not associated with an increase in acquisition of resistant flora.

Angiotensin-converting enzyme gene polymorphism and risk of myocardial infarction in Colombia.

BACKGROUND: The ACE gene insertion/deletion polymorphism has been studied as a risk factor for acute myocardial infarction (AMI) in different populations with conflicting results. MATERIAL/METHODS: We conducted a case-control study in first AMI cases matched by age (+/-5 years) and sex to controls with non-cardiac diseases to ascertain whether Colombian carriers of the DD genotype were at higher risk of AMI than carriers of the ID and II genotypes. Zygosity for the deletion-insertion (D-I) of the ACE gene polymorphism was determined by polymerase chain reaction. Logistic regression with adjustment for matching factors was used to estimate the independent effect of the DD polymorphism after controlling for traditional cardiovascular risk factors. RESULTS: Participants (n=202) had a mean age of 62 years and 32% were women. The distribution of the polymorphism was significantly different (p=0.001) in cases (II 8.9%; ID 51.5%; DD 39.6%) and controls (II 8.9%; ID 64.4%; DD 26.7%). After adjustment for other risk factors, the risk of AMI in subjects with genotype DD was 1.98 times higher than the risk in the combined group of genotypes II and ID (95% CI: 1.01, 3.87; p=0.04). There was a significant DD by age interaction (p=0.002). In subjects p=0.86), while in subjects <60 years the risk increased 5.16 times (95% CI: 1.68, 15.90; p=0.004). CONCLUSIONS: These results support an increased risk of AMI in Colombian subjects <60 years with the ACE DD genotype.