RESUMO
BACKGROUND: Sequence type 131 (ST131) of Escherichia coli is a pandemic clone that drives the increasing rates of antibiotic resistance. While the pervasiveness of ST131 clade C, especially subclades C2 and C1-M27, has been demonstrated in numerous global surveys, no report about the ST131 clades and their virotypes has been published from Iran so far. METHODS: A collection of 73 consecutive ST131 isolates from extraintestinal specimens was investigated for determination of virotypes, antibiotic susceptibility patterns, resistance/virulence determinants, and clade subsets. RESULTS: Most of the isolates belonged to subclade C2 (33/73; 45.2%), which had the highest virulence factor (VF) scores and resistance rates, followed by C1-M27 (18; 24.6%), C1-non-M27 (14; 19.1%), and A (8; 10.9%). The distinctive profiles of subclade C2 virulence genes were revealed by principle coordinates analysis testing. The distribution of the hlyA virulence gene among subclade C2 was not uniform, so that positive strains (21; 63.6%) showed significantly higher rates of resistance (bla CTX-M-15, bla OXA-1, aac(6')-Ib-cr, aac(6')-Ib, aac(3)-IIa) and virulence (hra, tia/hek, K5, cnf, papGII, papC) markers and gentamicin/tobramycin resistance. Virotype C as the most common virotype (34; 46.5%) was predominant among the subclade C1 population, while virotypes E and F (21; 28.7%) were detected among subclade C2, which had the highest VF scores and aminoglycoside resistance rates. CONCLUSIONS: The appearance of virotypes E and F among subclade C2 strains with higher rates of aminoglycoside resistance/virulence gene content shows the shifting dynamics of this pandemic clone in response to antibiotic selection pressure by establishing subsets with higher survival potential.
RESUMO
BACKGROUND: A gluten-free diet (GFD) is the only effective treatment for celiac patients and assessing adherence to this diet is important. Celiac disease Adherence Test (CDAT) is a valid English-language questionnaire that is used for assessing the adherence to the GFD. In the present study, we aimed to translate the CDAT questionnaire in Persian and evaluate its validity and reliability. METHODS: In the present cross-sectional study, CDAT was translated and back-translated by three bilingual professional translators. Content validity was evaluated by 12 gastroenterologists and nutritionists. To assess the construct validity, 230 patients with celiac disease were randomly selected from the national celiac disease registry database. Internal consistency of the items and test-retest reliability were assessed by Cronbach's alpha and Intraclass Correlation Coefficient (ICC). To assess the convergent validity of the questionnaire, the correlation coefficient between the CDAT score and anti-tissue transglutaminase immunoglobulin A (anti-t-TG-IgA) titer was assessed. RESULTS: The content validity index, content validity ratio, and impact score of the Persian version of CDAT (Pv-CDAT) were 0.97, 0.95, and 4.61 respectively. Three significant factors were extracted and according to the confirmatory factor analysis the three-factor model had adequate fitness (chi-square p-value of 0.74, root mean error of approximation: 0.001 [95% CI: 0.001-0.083], comparative fit index: 1, standardized root mean squared residual: 0.04, and coefficient of determination: 0.78). The questionnaire had good feasibility with the floor effect of 3.1% and the ceiling effect of 0.4%. Moreover, it has high internal consistency (Cronbach-alpha: 0.71) and test-retest reliability (ICC: 0.78). The correlations between CDAT categories and anti-tTG-IgA categories showed a significant correlation between the two tests (r = 0.53; P < 0.001). CONCLUSIONS: The results of the present study showed that the Pv-CDAT questionnaire with high validity, reliability, and internal consistency can be used for assessing adherence to the GFD in adult celiac patients in Iran.