Eurofins BioPharma Product Testing New Zealand offers a range of microbiological analyses for environmental water.

All tests are performed by membrane filtration to meet the requirements of the current APHA and pharmacopoeia.

Heterotrophic Plate Count (HPC)

Pour plates are performed on the sample at a suitable dilution range. As many waterborne micro-organisms will not grow at elevated temperatures, and micro-organisms indicative of poor hygiene generally grow well at higher temperatures, analysis is conducted under two temperature conditions. Incubating plates at both temperatures provides a better overall picture of the water quality. 

Test for E. coli and thermo-tolerant coliforms

These micro-organisms are useful indicators of possible faecal contamination of water and also suggest that there may be other pathogenic bacteria, parasites or viruses present. A suitable dilution, or range, is filtered and the membrane transferred to a selective agar plate and incubated at an elevated temperature (44°C). Following incubation suspect colonies are counted and confirmed.

The thermotolerant coliforms group includes E.coli and number of other similar bacteria. 

Test for coliforms

The test for the presence of coliforms is a more general test than that for E. coli and thermo-tolerant coliforms, and includes many non-pathogenic species. However, as a broader test it has the potential to detect contamination in water where pathogenic species are present in only very small numbers.

A suitable dilution, or range, is filtered and the membrane transferred to a selective agar plate and incubated at 37°C. Following incubation suspect colonies are counted and confirmed. 

Test for enterococci

These micro-organisms are useful indicators of possible faecal contamination of water and also suggest that there may be other pathogenic bacteria, parasites, or viruses present.

A suitable dilution, or range, is filtered and the membrane transferred to a selective agar plate and incubated at 44°C. Following incubation suspect colonies are counted and confirmed. 

Test for Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen commonly found in soil and water. It is able to tolerate and grow in a very wide variety of conditions. In or untreated water, it has the potential to cause skin and ear infections, and is of particular concern in spa water where the elevated temperature serves to reduce competition. 

A suitable dilution, or range, is filtered and the membrane transferred to a selective agar plate and incubated at 42°C. Following incubation suspect colonies are counted and confirmed.

Test for Pseudomonads

This test includes members of the Pseudomonas genus, as well as several other genera which have similar growth characteristics. 

Pseudomonads are commonly found in soil and water. The group includes opportunistic animal and plant pathogens such as P. aeruginosa and Burkholderia cepacia, with some species having uses as biocontrol and bioremediation agents.

A suitable dilution, or range, is filtered and the membrane transferred to a selective agar plate and incubated at 21°C. Following incubation suspect colonies are counted and confirmed. 

Sample requirements 

Sample size is dependent on the quality of the water to be tested. As a general guide, at least 100mL per test should be submitted.

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