 |
| |
|
 |
|
 |
|
 |
|
 |
|
|
|
| MACS Lab, Inc. |
|
| 3137 Diablo Avenue |
|
| Hayward, California 94545-2701 |
|
| (800) MACS LAB (800) 622-7522 |
|
| (510) 786-9751 |
|
| (510) 786-9625 Fax |
|
| Email info@macslab.com |
|
|
| Links |
|
| Kellco Services |
|
KELLCO-MACS
A Creative Joint Venture |
|
|
|
Significance of E. coli in drinking water
The detection of E. coli in a water system is a good indicator of recent fecal contamination because E. coli rarely grows outside the human or animal gut.
Acceptable Numbers: Zero
Escherichia coli is a member of the coliform group, and taxonomically belong to the family Enterobacteriaceae. It belongs to the facultative anaerobic, Gram-negative, rod-shaped bacterium that possesses the enzyme B-glucuronidase. Some strains of this bacterium can cause gastrointestinal illness along with other, more serious health problems.
|
Photo by Eric Erbe, digital colorization by Christopher Pooley, both of USDA, ARS, EMU |
|
|
Of the coliforms, E. coli is generally the most sensitive to environmental stresses. It has a short survival time in the environment (4-12 weeks in water containing a moderate microflora at a temperature of 15-18¡C).
Where is the source?
E. coli is naturally found in the intestines of humans and warm-blooded animals at a concentration of approximately 109 per gram (Edberg et al., 2000) and comprises about 1% of the total biomass in the large intestine (Leclerc et al., 2001).
|
|
|
Bacteria Analysis
Test Category: BG Presence of Gram Positive bacteria by using Gram stain.
While examining lung tissue from patients who had died of pneumonia (1884), Hans Christian Gram, a Danish doctor discovered that certain stains were preferentially taken up and retained by bacterial cells. He also developed a staining procedure which divided almost all bacteria into two large groups: Gram + and Gram - (with a few exceptions).
Test Category: EL Detection of total coliforms and E. coli in drinking water, groundwater or surface water using Colilert / Colitag (Presence/Absence). MACS Lab is accredited by the California Department of Public Health (ELAT Program, Certificate #2027) to perform analysis for bacteria and E. Coli.
Test Category: EN Enumeration of total coliforms and E. coli in drinking water, groundwater or surface water using Colilert / Colitag methods (Enumeration).
The Colilert test can detect these bacteria at 1 cfu/100 mL within 24 hours with as many as 2 million heterotrophic bacteria per 100 ml present.
Some Non-coliform bacteria, (like Aeromonas and Pseudomonas) producing small amounts of the enzyme B-D-galactosidase can not produce a positive response within 28 hours. Presence of these bacteria is used to indicate whether other potentially harmful bacteria may be present.
References:
1. Bacterial Waterborne Pathogens: Current and Emerging Organisms of Concern (Health Canada, 2006a).
2. Kudryavtseva, 1972; Filip et al., 1987; Edberg et al., 2000
3. http://www.hc-sc.gc.ca/ewh-semt/index_e.html
4. http://www.epa.gov.org/WDW//contaminants/index.html#micro
|
|
|
|
