Characteristics of human intestinal Escherichia coli with changing environments.

To investigate if the characteristics of human intestinal Escherichia coli are changing with the environment of the host, we studied intestinal E. coli from subjects having recently migrated from a temperate to a tropical area. We determined the phylogenetic group, the prevalence of the antibiotic resistance, the presence of integrons and the strain diversity in faecal isolates from 25 subjects originally from metropolitan France and expatriated to French Guyana. These characteristics were compared with those of 25 previously studied Wayampi Amerindian natives of French Guyana and from 25 metropolitan French residents. The three groups of subjects were matched for age and sex, had not taken antibiotics for at least 1 month, nor had been hospitalized within the past year. In all, the characteristics of intestinal E. coli from Expatriates were intermediate between those found in residents from metropolitan France and those found in natives of French Guyana. Prevalence of carriage of resistant Gram-negative bacteria in Expatriates was intermediate between French residents and Wayampi as were the prevalence of integrons in E. coli (12.3% versus 16.3% and 7.8% respectively), and the intra-host diversity of E. coli (2.3 strains/subject versus 1.9 and 3.1, respectively); lastly, in Expatriates, the prevalence of carriage of phylogenetic group B2 strains was lower than in French residents (16% versus 56%, P = 0.005), while carriage of phylogenetic group A strains was lower than in Wayampi (56% versus 88%, P = 0.03). Our results suggest that the composition of the commensal intestinal flora of humans is not static but changes dynamically in response to new environmental conditions.

[Double reading in breast-cancer screening: what women know about it]. / Connaissance de la double lecture dans le dépistage du cancer du sein.

OBJECTIVE: An officially-sponsored and free breast cancer screening in France was extended to all regions in 2004. These mammography procedures include double reading, which reduces the number of false negatives. Together with this official program, administered by associations in each district, voluntary individual screening is still available. The aim of this study is to ascertain what women think about breast cancer screening, why they choose one method of screening or the other, and what they know about "double reading". METHODS: A postal survey inquiring about the kind of screening chosen and the reasons for this choice was sent to women aged 50 to 74 years covered by the national military health insurance fund. After descriptive analysis of the results, we compared the respondents' knowledge of double reading according to residence (two departments, one rural one and one urban), age, and educational level. RESULTS: 541 of the 994 eligible women responded (54%). More than 94% of them had had a mammography within the past two years, 62.1% through the official program. Women who had participated in the official screening knew more about "double reading" than the others (71.6% versus 50%, p<0.05 in the rural district and 67.4% versus 63.9% in the urban district). In the latter, familiarity with double reading increased as age decreased. Individual mammography depended on prior habits and gynecologists' prescriptions. DISCUSSION: Women must shift from individual mammography to the official program to receive a standardized, double-read, and quality-controlled mammography. Prescribing physicians should serve as an additional entryway into the organized program.