A library of 18 coliform bacteria strains was obtained from different sampling points in the drinking water distribution system in Lexington, KY, over a three month period in 2006. To investigate the cause of the coliform occurrence we conducted a microbial source tracking study using phenotypic (API 20E, Biolog, and Vitek) and genotypic (pulsed field gel electrophoresis (PFGE) and ribotyping) analyses to determine the degree of genetic variation among isolates. Characterization of isolates by PFGE and ribotyping showed that coliform events in the distribution system were related and a regrowth problem may exist due to biofilm formation. The ability of a persistent Enterobacter cloacae strain to adhere and form biofilm was found to depend on environmental conditions such as temperature, pipe material, soiled surface, chlorine and nutrient levels with higher temperatures and nutrient levels promoting adherence. Considerable variation in adherence and biofilm formation was observed among representative Enterobacter isolates.

Background: Diarrhea is the passage of 3 or more loose or liquid stools per day. Globally, it is the second-leading cause of death among under-five children, accounting for 9% of all under-five deaths, and kills more young children than Acquired Immunodeficiency Syndrome (AIDS), malaria and measles combined. In developing countries, an estimated 1.8 million people die annually due to diarrheal diseases, and more than 80% of them are children under 5 years, while 88% of these deaths are in South Asia and Sub-Saharan Africa (SSA). There are limited studies that investigate the prevalence and factors associated with diarrhea in SSA despite the health burden. Method: The Demographic and Health Survey (DHS) children’s recode dataset of 2015 for Chad was used for this study. The predictor variables were; age of child, source of drinking water, maternal highest level of education, drank from bottle with nipple, and the outcome variable was diarrhea recently. Descriptive statistics for all variables were completed, and Chi-square analyses were conducted to determine associations between predictor variables and the outcome, diarrhea recently. Simple and multiple logistic regressions were completed to determine factors that predict diarrhea in the last two weeks. Odds ratios, 95% confidence intervals, and p-values were reported. Results: The total sample size was (N=16,710). About 3292 (19.70%) children had diarrhea, 13418 (80.30%) children had no diarrhea. A high prevalence of diarrhea in under-five children was observe particularly in those who drink water from unprotected well (1070 cases), had mothers with only primary level of education (796 cases), and did not drink from bottles with nipple (2961 cases). Based on the age of child, the odds of having diarrhea were over 60% lower in children 3 years old and below [aOR = 0.39, C.I (0.279-0.538), p <.0001] compared to 4 years old and above. Based on the source of drinking water, children that drank from a protected spring were 74% less likely to have diarrhea [0.26, 0.084-0.827, p=0.0223] compared to those that drank from other sources. The study also showed that children that drank from bottles with nipple were 16% less likely of having diarrhea [0.84, 0.726-0.968, p=0.0166] compared to those that did not drink from bottles with nipple. However, maternal highest level of education had no significant association with the odds of having diarrhea in these children. Conclusion: Caregivers should ensure absolute hygiene and provide safe drinking water to under-five children, especially those above 3 years who may easily access contaminated water sources themselves. We also encourage the use of bottles with nipple heads for drinking in children. Further studies are needed in SSA on other factors influencing diarrhea risk in those under five.