Risk Factors for Detection, Survival, and Growth of Antibiotic-Resistant and Pathogenic Escherichia coli in Household Soils in Rural Bangladesh

• Published in: Applied and environmental microbiology Vol. 84; no. 24
• Main Authors: Montealegre, Maria Camila, Roy, Subarna, Böni, Franziska, Hossain, Muhammed Iqbal, Navab-Daneshmand, Tala, Caduff, Lea, Faruque, A S G, Islam, Mohammad Aminul, Julian, Timothy R
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 15.12.2018
• Subjects: Antibiotic resistance; Antibiotics; Bacteria; Chickens; Clay soils; Drug resistance; E coli; Escherichia coli; Households; Hygiene; Intestine; Microcosms; Multidrug resistance; Pathogenicity; Pathogens; Poultry; Public and Environmental Health Microbiology; Risk analysis; Risk factors; Rural areas; Rural environments; Sanitation; Soil investigations; Soil moisture; Soil testing; Soils; Survival; β Lactamase; Bangladesh; Bangladesh; CTX-M-group 1; enteropathogenic; persistence; growth; households; soils; E. coli; ESBL-E
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.01978-18

Soils in household environments in low- and middle-income countries may play an important role in the persistence, proliferation, and transmission of Our goal was to investigate the risk factors for detection, survival, and growth of in soils collected from household plots. was enumerated in soil and fecal samples from humans, chickens, and cattle from 52 households in rural Bangladesh. Associations between concentrations in soil, household-level risk factors, and soil physicochemical characteristics were investigated. Susceptibility to 16 antibiotics and the presence of intestinal pathotypes were evaluated for 175 isolates. The growth and survival of in microcosms using soil collected from the households were also assessed. was isolated from 44.2% of the soil samples, with an average of 1.95 log CFU/g dry soil. Soil moisture and clay content were associated with concentrations in soil, whereas no household-level risk factor was significantly correlated. Antibiotic resistance and pathogenicity were common among isolates, with 42.3% resistant to at least one antibiotic, 12.6% multidrug resistant (≥3 classes), and 10% potentially pathogenic. Soil microcosms demonstrate growth and/or survival of , including an enteropathogenic extended-spectrum beta-lactamase (ESBL)-producing isolate, in some, but not all, of the household soils tested. In rural Bangladesh, defined soil physicochemical characteristics appear more influential for detection in soils than household-level risk factors. Soils may act as reservoirs in the transmission of antibiotic-resistant and potentially pathogenic and therefore may impact the effectiveness of water, sanitation, and hygiene interventions. Soil may represent a direct source or act as an intermediary for the transmission of antibiotic-resistant and pathogenic strains, particularly in low-income and rural settings. Thus, determining risk factors associated with detection, growth, and long-term survival of in soil environments is important for public health. Here, we demonstrate that household soils in rural Bangladesh are reservoirs for antibiotic-resistant and potentially pathogenic strains and can support growth and survival, and defined soil physicochemical characteristics are drivers of survival in this environment. In contrast, we found no evidence that household-level factors, including water, sanitation, and hygiene indicators, were associated with contamination of household soils.