The compartment bag test (CBT) for enumerating fecal indicator bacteria: Basis for design and interpretation of results

Gronewold, Andrew D.; Sobsey, Mark D.; McMahan, Lanakila

doi:10.1016/j.scitotenv.2017.02.055

Cited by 13 publications

(9 citation statements)

References 35 publications

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“…Water quality was assessed in the UBCS using a compartment bag test (CBT kit; Aquagenx, Chapel Hill, NC) 35 at the 6-month time-point. The compartment bag test (CBT) is a portable water quality test kit designed to detect and quantify Escherichia coli bacteria.…”

Section: Methodsmentioning

confidence: 99%

Unsafe Drinking Water Is Associated with Environmental Enteric Dysfunction and Poor Growth Outcomes in Young Children in Rural Southwestern Uganda

Lauer

Duggan

Ausman

et al. 2018

The American Journal of Tropical Medicine and Hygiene

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Abstract.Environmental enteric dysfunction (EED), a subclinical disorder of the small intestine, and poor growth are associated with living in poor water, sanitation, and hygiene (WASH) conditions, but specific risk factors remain unclear. Nested within a birth cohort study, this study investigates relationships among water quality, EED, and growth in 385 children living in southwestern Uganda. Water quality was assessed using a portable water quality test when children were 6 months, and safe water was defined as lacking Escherichia coli contamination. Environmental enteric dysfunction was assessed using the lactulose:mannitol (L:M) test at 12–16 months. Anthropometry and covariate data were extracted from the cohort study, and associations were assessed using linear and logistic regression models. Less than half of the households (43.8%) had safe water, and safe versus unsafe water did not correlate with improved versus unimproved water source. In adjusted linear regression models, children from households with safe water had significantly lower log-transformed (ln) L:M ratios (β: −0.22, 95% confidence interval (CI): −0.44, −0.00) and significantly higher length-for-age (β: 0.29, 95% CI: 0.00, 0.58) and weight-for-age (β: 0.20, 95% CI: 0.05, 0.34) Z-scores at 12–16 months. Furthermore, in adjusted linear regression models, ln L:M ratios at 12–16 months significantly decreased with increasing length-for-age Z-scores at birth, 6 months, and 9 months (β: −0.05, 95% CI: −0.10, −0.004; β: −0.06, 95% CI: −0.11, −0.006; and β: −0.05, 95% CI: −0.09, −0.005, respectively). Overall, our data suggest that programs seeking to improve nutrition should address poor WASH conditions simultaneously, particularly related to household drinking water quality.

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Section: Methodsmentioning

confidence: 99%

Unsafe Drinking Water Is Associated with Environmental Enteric Dysfunction and Poor Growth Outcomes in Young Children in Rural Southwestern Uganda

Lauer

Duggan

Ausman

et al. 2018

The American Journal of Tropical Medicine and Hygiene

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“…5 (Aquagenx, 2021). CBTs produce a quantitative estimate of E. coli concentration based on a most probable number (MPN) per 100 mL (Stauber et al, 2014;Gronewold et al, 2017).…”

Section: Measurements Of E Coli Bacteriamentioning

confidence: 99%

Water circulation and impact on water quality in the southwest of Efate Island, Vanuatu

Faivre

Sami

Mackey

et al. 2021

Marine Pollution Bulletin

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In Small Island Developing States (SIDS), water pollution is not monitored or assessed frequently enough to fully understand the processes, impacts of water quality issues and what solutions are available This study investigated flushing time in Erakor lagoon and Port Vila Bay, Vanuatu using a numerical model developed in Delft3D. Microbial contamination by Escherichia coli was detected in multiple locations in the lagoon system with counts exceeding thresholds related to human health concerns. Modelling demonstrated a poor flushing time overall with a further decrease as the influence of waves and wind increased, especially in Vila Bay. Sea level rise resulted in an increase in flushing time downstream of the lagoon near the open sea, while with a decrease upstream and in Vila Bay. Based on these results, we recommend long-term continuous monitoring and identification of higher risks areas to prioritise decisions around wastewater management.

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“…The CBT method from Aquagenx was chosen for E. coli sampling based on its low cost and sample processing time. The CBT approach is relatively new and it uses a statistically derived most probable number (MPN) table to estimate E. coli concentrations (Gronewold et al, 2017). In contrast, the more established PC methods produce results in colony forming units (CFU).…”

Section: Bacteria Samplingmentioning

confidence: 99%

Tryptophan-like fluorescence as a measure of microbial contamination risk in groundwater

Nowicki

Lapworth

Ward

et al. 2019

Science of The Total Environment

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Microbial water quality is frequently assessed with a risk indicator approach that relies on Escherichia coli. Relying exclusively on E. coli is limiting, particularly in low-resource settings, and we argue that risk assessments could be improved by a complementary parameter, tryptophan-like fluorescence (TLF). Over two campaigns (June 2016 and March 2017) we sampled 37 water points in rural Kwale County, Kenya for TLF, E. coli and thermotolerant coliforms (total n = 1082). Using three World Health Organization defined classes (very high, high, and low/intermediate), risk indicated by TLF was not significantly different from risk indicated by E. coli (p = 0.85). However, the TLF and E. coli risk classifications did show disagreement, with TLF indicating higher risk for 14% of samples and lower risk for 13% of samples. Comparisons of duplicate/replicate results demonstrated that precision is higher for TLF (average relative percent difference of duplicates = 14%) compared to culture-based methods (average RPD of duplicates ≥ 26%). Additionally, TLF sampling is more practical because it requires less time and resources. Precision and practicality make TLF well-suited to high-frequency sampling in low resource contexts. Interpretation and interference challenges are minimised when TLF is measured in groundwaters, which typically have low dissolved organic carbon, relatively consistent temperature, negligible turbidity and pH between 5 and 8. TLF cannot be used as a proxy for E. coli on an individual sample basis, but it can add value to groundwater risk assessments by improving prioritization of sampling and by increasing understanding of spatiotemporal variability.

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The compartment bag test (CBT) for enumerating fecal indicator bacteria: Basis for design and interpretation of results

Cited by 13 publications

References 35 publications

Unsafe Drinking Water Is Associated with Environmental Enteric Dysfunction and Poor Growth Outcomes in Young Children in Rural Southwestern Uganda

Unsafe Drinking Water Is Associated with Environmental Enteric Dysfunction and Poor Growth Outcomes in Young Children in Rural Southwestern Uganda

Water circulation and impact on water quality in the southwest of Efate Island, Vanuatu

Tryptophan-like fluorescence as a measure of microbial contamination risk in groundwater

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