Healthy children in urban areas have a high prevalence of fecal carriage of drug-resistant E. coli.

No abstract

This report on epilepsy prevalence in Bolivia confirms that epilepsy is a major health problem in rural areas of developing countries.

Accurate assessment of risk factors for nosocomial acquisition of colonization by antibiotic-resistant bacteria (ARB) is often confounded by scarce data on antibiotic use. A 12-month, nested, multicenter cohort study was conducted. Target ARB were methicillin (meticillin)-resistant Staphylococcus aureus (MRSA), vancomycinresistant enterococci (VRE), and ciprofloxacin-resistant Pseudomonas aeruginosa (CR-PA). Nares and rectal swabs were obtained before and after starting antibiotics. Pulsed-field gel electrophoresis was done to define genetic relatedness of the strains. Primary outcomes were (i) the mean time, in days, for acquisition of target ARB colonization in patients previously not colonized; (ii) the rate of acquisition per 1,000 antibiotic-days according to different classes of antibiotics; (iii) the rate of infection caused by the same bacteria as those previously isolated in screening samples; and (iv) the risk factors for ARB acquisition. In total, 6,245 swabs from 864 inpatients were processed. The rate of acquisition was 3%, 2%, and 1% for MRSA, VRE, and CR-PA, respectively. The rate of acquisition of ARB per 1,000 antibiotic-days was 14 for carbapenems, 9 for glycopeptides, and 6 for broad-spectrum cephalosporins and quinolones. The highest rates of acquisition were observed for carbapenems in dialyzed and diabetic patients. Four risk factors were independently associated with acquisition of target ARB: use of carbapenems, age of >70 years, hospitalization for >16 days, and human immunodeficiency virus infection. During the 30-day follow-up, 4 among 42 patients newly colonized by ARB (9%) suffered from an infection due to the same bacteria as those isolated in a previous screening sample. Colonizing and infecting strains from single patients were genotypically identical. Identifying ARB colonization early during antibiotic therapy could target a high-risk hospitalized population that may benefit from intervention to decrease the risk of subsequent nosocomial infections.The control of nosocomial antibiotic-resistant infections is a public health priority worldwide. Meta-analyses have documented that bloodstream infection caused by methicillin (meticillin)-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum ␤-lactamase-producing Enterobacteriaceae, and multidrug-resistant Acinetobacter baumannii are associated significantly with mortality (7,9,11,24). Numerous papers have demonstrated that prior antimicrobial drug exposure is a strong risk factor for colonization and infection due to a drug-resistant pathogen (2,25,27). However, the association between antibiotic therapy and the acquisition of antibiotic-resistant bacteria (ARB) is still unclear and is often confounded by scarce data on antibiotic usage. In our opinion, two major questions are still unsolved. When does an antibiotic select colonizing ARB in a hospitalized patient? Is there a direct correlation between hospital antibiotic usage, acquisition of ARB colonization, and subsequent bacterial infe...

In a previous study, we detected unexpectedly high levels of acquired antibiotic resistance in commensal Escherichia coli isolates from a remote Guaraní Indian (Bolivia) community with very low levels of antibiotic exposure and limited exchanges with the exterior. Here we analyzed the structure of the resistant E. coli population from that community and the resistance mechanisms. The E. coli population (113 isolates from 72 inhabitants) showed a high degree of genetic heterogeneity, as evidenced by phylogenetic grouping (77% group A, 10% group B1, 8% group D, 5% group B2) and genotyping by randomly amplified polymorphic DNA (RAPD) analysis (44 different RAPD types). The acquired resistance genes were always of the same types as those found in antibiotic-exposed settings [bla TEM , bla PSE-1 , catI, cmlA6, tet(A), tet(B), dfrA1, dfrA7, dfrA8, dfrA17, sul1, sul2, aphA1, aadA1, aadA2, aadA5, aadB, and sat-1]. Class 1 and class 2 integrons were found in 12% and 4% of the isolates, respectively, and harbored arrays of gene cassettes similar to those already described. The cotransferability of multiple-resistance traits was observed from selected isolates and was found to be associated with resistance conjugative plasmids of the F, P, and N types. Overall, these data suggest that the resistance observed in this remote community is likely the consequence of the dissemination of resistant bacteria and resistance genes from antibiotic-exposed settings (rather than of an independent in situ selection) which involved both the clonal expansion of resistant strains and the horizontal transfer/recombination of mobile genetic elements harboring resistance genes.The notion that the global dissemination of microbial drug resistance observed in the antibiotic era is related to the selective pressure generated by the use of antibiotics in clinical and veterinary practices, animal husbandry, and agriculture is supported by studies that have clearly correlated the emergence and dissemination of resistance with the use of antibiotics (1,10,19) and by the absence of acquired resistance in clinical isolates from the preantibiotic era (13,14). Surprisingly, however, antibiotic-resistant bacteria have also recently been detected in humans and wild animals living in remote areas where antibiotic exposure has been absent or minimal (2,9,11,22,30,32), raising a question about the mechanisms of resistance spread in those settings. To the best of our knowledge, the most isolated human context thus far investigated is represented by a very remote community of Guaraní Indians in the Bolivian Chaco, where we detected high levels of acquired antibiotic resistance in commensal Escherichia coli isolates (2). In that community, exchanges with inhabitants of other areas were very limited; antibiotic exposure at the time of the study had been minimal; and locally collected rainwater was the only water source, ruling out the possibility of sustained contamination of drinking water from the exterior (2).In this work we have analyzed the population struc...