Fecal Carriage of Extended-Spectrum beta-Lactamase Producing Escherichia coli among Health Science Students.

BACKGROUND: The incidence of antibiotic resistance in commensal bacteria is increasing with the production of extended-spectrum beta-lactamase. Therefore, this study was conducted to understand the status of fecal carriage of such enzyme producing Escherichia coli among health science students of seven different faculties of Institute of Medicine, Tribhuvan University. METHODS: This was a cross-sectional study conducted over six months among the health science students. One stool sample collected from each student was cultured and Escherichia coli isolates were identified, antibiotic sensitivity profile was produced, and extended-spectrum beta-lactamase production was detected following Clinical and Laboratory Standards Institute guidelines. RESULTS: A total of 156 students participated in the study, and Escherichia coli was isolated from all. Out of the total 156 Escherichia coli isolates, 11.5% were extended-spectrum beta-lactamase-producers and 14.7% were multidrug-resistant. The highest rate of fecal carriage of extended-spectrum beta-lactamase-producing Escherichia coli was found among Bachelor of Medicine and Bachelor of Surgery students (17.5%) and Bachelor of Science in Medical Imaging Technology (16.7%) students. Such enzyme producing Escherichia coli was found in the range of 6.9% to 25.0% among second- to fifth-year students. A significant number of extended-spectrum beta-lactamase-producing isolates were resistant to ciprofloxacin and gentamicin, apart from other extended-spectrum beta-lactamase substrate antibiotics, when compared with non-producers. CONCLUSIONS: A high rate of extended-spectrum beta-lactamase-producing Escherichia coli was detected from the gut of healthy health science students which indicates their possible dissemination throughout the wider community resulting in potential outbreak of infections caused by such organisms.

The concentration of free holo-retinol binding protein is higher in vitamin A-sufficient than in deficient Nepalese women in late pregnancy.

Free holo-retinol binding protein (RBP) [i.e., unbound to transthyretin (TTR)] plays a role in transporting vitamin A across the placenta during pregnancy. In a cross-sectional study of clinically healthy urban women, we assessed the association among clinical and biochemical factors on estimated concentrations of free holo-RBP during the last trimester of pregnancy. Serum samples obtained from a subsample of women (n = 259), who had participated in the Night Vision Threshold Test study in Nepal, were analyzed for determinations of retinol by HPLC, and RBP, TTR, and alpha-1 acid glycoprotein by radial immunodiffusion. Free holo-RBP concentrations were calculated using dissociation constants for free holo- and apo-RBP. Among these women, 30% were vitamin A deficient based on either the RBP:TTR index < or = 0.36 or serum retinol < 1.05 micromol/L. Using stepwise regression analyses, the RBP:TTR index explained 75% of the variance in free holo-RBP concentrations, whereas retinol explained only 14%. Women were classified as vitamin A sufficient (n = 185) or deficient (n = 74) using the RBP:TTR index and were stratified into 3 gestational groups (I: 24-28 wk, II: 29-33 wk, III: >33 wk). Concentrations of free holo-RBP were higher in vitamin A-sufficient women than in vitamin A-deficient women (mean +/- SEM, 48.1 +/- 1.2 vs. 27.6 +/- 0.8 nmol/L; P < 0.001), and in a 3 x 2 factorial analysis, the interaction between gestational group and vitamin A status was significant. These results demonstrate that the RBP:TTR index is a useful proxy for free holo-RBP concentration and that vitamin A status affects its distribution.

The night vision threshold test is a better predictor of low serum vitamin A concentration than self-reported night blindness in pregnant urban Nepalese women.

This study was conducted to validate the night vision threshold test (NVTT) as an indicator of night blindness. A total of 1401 pregnant women from the National Maternity Hospital participated in this study. Women were queried about night blindness and took the NVTT using standardized procedures after 10 min of dark adaptation. Sixteen percent failed the NVTT, but only 6.4% reported having night blindness. Blood samples from women who failed the NVTT (cases) and matched controls indicated the serum vitamin A (SVA) concentration was lower (P < 0.05) in cases (1.19 +/- 0.03 micromol/L) than in controls (1.29 +/- 0.03 micromol/L). The SVA concentrations did not differ between women who reported and did not report night blindness. The SVA concentration was correlated (r = 0.22, P < 0.001) with the NVTT scores. Twenty-five percent of women with an SVA < 0.35 micromol/L reported night blindness while 100% failed the NVTT. Nineteen percent of women with an SVA < 0.70 micromol/L reported night blindness while 73% failed the NVTT. A receiver operating characteristics analysis indicated that the NVTT had greater sensitivity (0.73 vs. 0.19) and less specificity (0.51 vs. 0.87) compared with reported night blindness for women with SVA < 0.70 micromol/L and greater sensitivity (100.0 vs. 0.73) and similar specificity (0.51 vs. 0.50) for women with SVA < 0.35 micromol/L. The NVTT identified women with low SVA and self-reported night blindness was misleading. We provide a preliminary algorithm to predict the population of women with low SVA concentrations.