Water microbiology Part 1 Flashcards
Public health?
Portability of water
Treatment process
One of the qualification for RMT ?
Water analyst
Where do you train for water analyst
One of the national reference laboratory for Environmental and Occupational Health, Toxicology and Micronutrient Assa (NRL - EOHTMA)
East Avenue Medical Center
What are the standard References for Water analyst?
Standard Methods for the Examination of Water and Wastewater (SiMEWW)
Philippine National Standards for Drinking Water
Procedures intended for the examination of waters of a wider range of quality
Standard Methods for the Examination of Water and Wastewater
NOTE: For SIMEWW
Covers:
- Domestic or industrial supplies
- Surface water
- Ground Water
- Cooling or Circulating water
- Boiler water
- Boiler feed water
- Treated and untreated municipal or industrial wastewater
- Saline water
Water comes from industrial factories that uses for cleaning, etc.
Wastewater
Philippine National Standards for Drinking Water is also known as?
Administrative order 2017-0010
Standards have been set by Philippines DOH in order to ensure that the general public is given access to safe drinking water
Philippine national Standards for Drinking water
4 Water analysis
Physical
Chemical
Microbiological
Radiological
Water analysis that determines temp, turbidty, etc
Physical
Water analysis that determines the amount of reagents such as reagents, etc
Chemical
Water analysis that determines the amount of microbes in the water?
Microbiological
Water analysis that determine the radio isotopes in the water?
Radiological
NOTE: PNSDW
free from contamination by human and
animal excreta
indices of potential water borne diseases
The major interest in classifying and issuing standards is the
identification, quantification, and evaluation of organisms associated with
waterborne diseases.
Frequent examination for fecal indicator organisms remain as the most
sensitive and specific way of assessing the hygienic quality of water.
major interest in classifying and issuing standards is?
Identification
Quantification
Evaluation of organisms
Most sensitive and specific
Provides evidence of fecal contamination from humans or warm-blooded animals
Indicator organism
Criteria for indicator Organisms
Always present
Large numbers in the feces
Respond to natural environmental conditions
Readily detectable
Ratio of indicator/pathogen should be high
Comes from the same source (GIT)
NOTE:
“No organism fulfills all the criteria for an indicator organism, but the coliform bacteria fulfill most”
What Family of bacteria is can be considered coliform group?
Enterobacteriaceae
Incubation for fermentation of Enterobacteriaceae?
35 C within 48 hrs
What is the indicator organism for Coliform bacteria?
Escherichia coli
What is the characteristics for Enterobacteriaceae?
Facultatively anaerobic
Gram (-)
Non spore forming
Rod shaped
Bacteria that ferment lactose with gas
acid formation
Routine analysis for Drinking water
Heterotrophic plate Count
Coliform count (Total and Thermotolerant Coliform count)
Describes a broad group of bacteria that include pathogens nonpathogens and opportunistic microorganisms
Heterotrophic bacteria
indicate general biological condition of drinking water as a consequence of insufficiency of treatment process, regrowth or recontamination of drinking water in the distribution system
Heterotrophic plate count
3 Procedures for heterotrophic plate count?
Pour plate
Spread plate
Membrane Filtration technique
Subgroup of total coliforms that are differentiated using elevated temperature
Thermotolerant fecal coliforms
What is the temp for thermotolerant fecal coliforms?
43 - 44.5 C
Collection container:
Nonreactive borosilicate glass or plastic bottles
(Final rinse: Deionized / Distilled water)
Sterilized: 121C in 15mins
The containers must be able to contain at least__________ with additional space to facilitate
mixing.
250 mL
A minimum amount of _________ is required if
samples are to be tested for presence of total
coliform, thermotolerant coliform and
heterotrophic bacteria.
150 mL
NOTE: Bottles must be unopened and kept away from
contamination until it is required for filling.
During filling the stopper and the cap must be
removed as a unit
A __________ is added to collection
containers of water having residual chlorine or
other halogens
reducing agent
(Dechlorination)
What is the reducing agent the neutralized any residual halogen and prevents continuation of bactericidal action during sample transit?
Sodium thiosulfate
What is the concentration for Sodium thiosulfate to neutralize 5 mg/L residual chlorine?
0.1 mL of a 3% solution
How to transport samples?
Zip locked bags that contains wet ice (10C)
What is the holding time for coliform count?
30 hrs
What is the holding time for heterotrophic plate count?
8 hrs
Temp for storage?
2-4C
What is the retention time for storage?
Month or longer
What is the standard hold time for both coliform and heterotrophic plate count in the Philippines?
24 hrs
Label:
Location
Treatment for water
Date of colletion
Time of collection
Who collected
What water is use for the final rinse before sterilizing the nonreactive borosilicate glass
Distilled or deionized water
What is the holding time for storage if positive?
1 month
What is the holding for storage if negative?
3 days
Procedure in collecting water
- Aseptically clean the faucet (Bleach then alcohol)
- Flame the tip of the faucet
- leave the running water for 1 min
- Collect the water (Make sure to leave a space on the top)
- Label
- Transport (10C) - Retention (HPC: 30 hrs, CC: 8 hrs)
- Storage (2-4 C)
