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Another person whihc now totals 13 has come down with the deadly Legionnaires’ disease and health officials say the bacteria that causes the deadly respiratory ailment has been found at a second location, a Syracuse nursing home in NY.

So far investigators searching for the potential source of the outbreak have discovered that the Legionella bacteria that causes the illness in the water system of the 526-bed Van Duyn Home and Hospital, said Gary Sauda, the Onondaga County director of environmental health.

Legionnaires’ is a severe form of pneumonia. People become infected by inhaling airborne water droplets that contain the bacteria. It can be fatal if left untreated.

So far one person has died since the outbreak began June 30, although health officials said they have not yet confirmed Legionnaires’ was the cause of the person’s death.

Investigators suspect the outbreak was caused by Legionella bacteria discovered in one of the air conditioning cooling towers at Community General Hospital, but they have not yet proven it. Six of 13 people infected were Community General patients.

In Legionnaires’ outbreaks, people up to two miles away from the source can be infected. The nursing home and hospital are located less than a half mile apart.

The staff at Van Duyn is working with state health department officials to minimize risks to the nursing home’s residents, Sauda said.

On Wednesday, officials at Community General reported that their first effort to kill the Legionella bacteria in its cooling towers two weeks ago did not work. The hospital performed a 24-hour disinfection process July 4. The hospital received test results Tuesday showing the bacteria was still present.

At that point, the hospital had already carried out a second 48-hour disinfection process over the weekend, following federal Centers for Disease Control and Prevention guidelines, said Tom Quinn, the hospital’s president and chief executive officer.

Test results from the second cleaning may not be available for two weeks, he said.

Source

Legionella bacteria was discovered during routine testing in part of the water sytem within the prison in Kent. As a response, the area has been evacuated.

Inmates in one wing of Maidstone Prison were moved to other jails, while blood tests on a prison officers proved negative, the Ministry of Justice said.

Dr Mathi Chandrakumar, from Kent Health Protection Unit, said none of the prisoners had been affected, however further checks are still on-going.

The Prison Officers Association (POA) said over 80 inmates were moved to other jails, some as far as Durham.

A POA spokesman said the bacteria was found in the shower system in one wing.

A spokeswoman for the Ministry of Justice said it was a mild strain of the bug and the evacuation was a precaution for the safety of prisoners and staff.

“The prison is working closely with public heath officials, to ensure the full process is carried out appropriately,” she added.

And she said the wing would be cleaned, sanitised and then mothballed for pre-planned refurbishment in January 2008.

Hospital tests were carried out on a prison officer on Saturday, she added.

“The officer was discharged and returned to work the following day. The tests did not indicate that the officer has Legionella disease,” she said.

Victorian wings

Maidstone MP Ann Widdecombe praised prison officers for acting quickly.

She said the problem stemmed from overcrowded jails.

Speaking to BBC Radio Kent, she said: “I’m not terribly surprised by it.

“I think the prison service acted quickly. They warned me when they thought they had a problem.

“It seemed almost to be five minutes later that they said ‘Right, we’re going to take action’, so I think they’ve handled it properly.”

She added: “The problem is, when you’ve got prisons badly overcrowded as they are at the moment, and you are using what are described as Victorian wings, it isn’t always possible to be using simply appropriate accommodation.”

The prison currently holds nearly 600 inmates in four residential wings and one segregation unit.

Source

Following an inquest into the deaths of 3 people from the Legionella bacteria, it may now become compulsory for results of cooling towers to be made available to health officials.

According to Canterbury’s medical officer of health, Alistair Humphrey who told an inquest looking into three deaths from legionella in winter 2005 says that New Zealand should adopt a compulsory regime on testing and reporting of legionnaire’s disease.

All 3 deaths were part of an outbreak of 19 cases clustered in the southwest of Christchurch, Dr Humphrey told Southland-Central Otago coroner Trevor Savage at the inquest, which is likely to last two days.

“It is appropriate that New Zealand moves to adopt a compulsory regime,” Dr Humphrey said. “It will in my view minimise the risk of another outbreak and will be likely to save lives.”

Attention has centred on the cooling tower at the Ravensdown plant in the suburb of Hornby as a possible source, and the company had lawyer Robert Osborne at today’s hearing.

He asked about gaps in the testing of cooling towers, and reporting of results under the present voluntary regime, and Dr Humphrey agreed it was possible that none of the cases came from the Ravensdown cooling tower.

But Dr Humphrey also said: “Our view is that there is no way you can say none of them came from that point source. Everything pointed to a cluster in the southwest of Christchurch around the plant we are talking about, with what we found to be genetically identical species of legionella.”

He agreed with Mr Osborne that the strain was the ubiquitous Christchurch type of the disease.

Inquiries by health officials during the outbreak turned up 141 cooling towers. Some of the owners or those leasing the buildings had not co-operated by testing and providing results and had to be visited by officials.

It meant there were gaps in the knowledge of what was happening during the April to August outbreak. When tests were done it was not known how many had already used biocide to kill organisms in the cooling systems — a call made by health officials to contain the outbreak.

The inquest is hearing evidence on the deaths of Ross Hern 56, Peter Jones, 48, and Valmai Finlayson, 87, who died of legionnaire’s disease at Christchurch Hospital.

Legionella species are widely found in lakes, rivers, groundwater and soil. The hearing was told it was “generally benign” until it was turned into a mist and spread. This could be through hot water systems, air cooling systems, cooling towers, water spraying devices, water sprinklers, demisters, and spa pools. An Auckland outbreak had been traced to a high pressure hose used in a boat washing operation.

When Ravensdown tested its tower in April, it was found to have a high level of 2400 colony-forming units of legionella. Biocide was used and a later test showed the level was down to 260 units.

Ravensdown provided its results to the health authorities.

Dr Humphrey suggested four changes were needed to tighten testing and reporting procedures for legionella, consistent with requirements in New South Wales, Victoria, and now being considered by South Australia.

He wants local bodies to maintain a register of cooling towers, evaporation condensers, and scrubbing towers. In the 2005 outbreak it took health officials about two weeks to gather information on all these installations from Christchurch City Council records.

He also wants compulsory testing by owners and operators, and compulsory disclosure of the results to local authorities and medical authorities.

He also wants a consistent testing regime between commercial and industrial properties.

Giving evidence this afternoon, a senior technical adviser to the Department of Building and Housing, Bruce Trevor Klein, told the coroner that since 2004 all new buildings with water cooling towers required a building compliance certificate.

Owners were required to test their systems regularly for bacterial organisms.

Cooling towers under the 2004 Act had to be sited away from building air conditioning intake systems.

Building owners must furnish annual documents showing the cooling towers had been tested monthly for legionella bacteria.

Legislation required owners or operators of cooling towers showing a level of legionella bacteria exceeding 1000 colony-forming units (cfus) should notify a medical officer of health within 48 hours.

Test results had to be retained for two years.

Questioned by Mr Savage, Mr Klein said his department would need to investigate whether it would support the mandatory reporting of all water cooler test results to health authorities.

He cautioned against Canterbury Medical Officer of Health Alister Humphrey’s earlier assertion that New Zealand should adopt Australia’s reporting system.

Mr Klein said he understood the Ministry of Health was investigating adopting a system that would require the mandatory reporting of high legionella bacterial counts.

As the law stood now, building owners, cooling tower operators and laboratories had no onus to make such reports available despite having to test regularly and retain results.

Questioned by Donna Blandford, niece of the late Mr Hern, Mr Klein said under the Building Act, cooling tower owners or operators faced fines of up to $200,000 for non-compliance.

He was unaware of any prosecutions.

Source

Generally potable waters are defined as water which is intended for human consumption.

This water can be used for drinking, washing or showering and in the manufacturing of food product and drinks. Above all, the water should be safe to use and pleasing to the nose, eye and taste with no suspended matter, harmful chemicals or pathogenic micro-organisms.

The safety of water as it relates to public health is determined by its physical appearance, and the chemical and microbiological content, of these, the microbiological quality is seen as the most important.

Contamination of drinking water by micro-organisms is usually attributed directly or indirectly by animal or human faeces. These organisms will include bacteria, viruses and protozoa and the diseases that they cause vary from very mild to severe, and in some cases fatal. Those with the greatest risk are the very young, the sick and the elderly.

To assess whether water has been contaminated, indicator micro-organisms are tested and the two most common type are faecal coliforms and E. coli). This group of bacteria are present in high numbers within the faeces of warm blooded animals and its presence in water is undesirable.

The presence of coliforms means that the water is probably contaminated by faecal matter. Coliforms should not be detected in potable waters and their presence poses a serious health concern.

Quality potable water (i.e. drinking water) is as a general rule should be readily available throughout developed countries from various water authorities who closely scrutinise and monitor their product to ensure that it is safe to the consumer.

Pink slime at the surface of water trickling through an old mine in California is proving to be a haven for researchers in their quest to learn more about how bacterial communities co-exist in nature.

A letter published in Nature shows that it is possible to follow what micro-organisms are doing in their natural environment by identifying the range of proteins that they produce. The technique, utilized in a microbial community thriving in battery acid-like streams underground at Richmond Mine near Redding, California, combines recently developed ways to sequence microbial genes with methods to identify the range of proteins from specific microbial members.

Researchers from Oak Ridge National Laboratory and UC Berkeley discovered that Leptosprillium group II bacteria in these streams are exchanging large blocks of genes. While scientists have seen extensive gene transfer in bacteria, this is the first observation of exchange of huge genomic blocks in a natural microbial community.

“Consequently, this provides important information about the conservation of genetic resources to enable life to survive and thrive,” said ORNL’s Bob Hettich, a co-author and member of the Chemical Sciences Division. “Ultimately, the basic knowledge gained from this research will lead to a greater understanding of genetic diversity in related organisms and should lead to developments in human health
and bioremediation.”

The combination of mass spectrometry support from ORNL researchers with extensive reconstruction of genomes from community genomic data at UC Berkeley was a key component to this work, said Jill Banfield, who led the project. Banfield, a professor in UC Berkeley’s Department of Environmental Science, Policy and Management, expects this to have far reaching implications.

“More important perhaps is the demonstration of our ability to simultaneously identify a large fraction of an organism’s proteins and to distinguish them from proteins derived from quite closely related organisms,” Banfield said. “This opens the way for detailed studies of how a wide range of microbial communities are structured and how they function.” Hettich agreed that today’s powerful molecular tools are playing a vital role in investigating the complexity of how bacterial consortia cooperate and compete in nature. In fact,
ORNL mass spectrometry provided the ability to resolve and differentiate peptides that differ by as little as one amino acid.

Nathan VerBerkmoes of the lab’s Chemical Sciences Division was instrumental in designing the experiments and acquiring the mass spectrometry data while Manesh Shah of the Biosciences Division provided the bioinformatics horsepower to sort through the massive datasets.

“A key aspect of this paper is the ability to get proteome information on organisms that do not directly have complete genome sequencing information,” VerBerkmoes said. “As a result we could study organisms related to those completely sequenced - such as the bacterial clades, or ‘cousins,’ that are likely to exist in natural environments”.

“This also might have implications into helping study human proteomics because not everyone’s individual genome will be sequenced.”

The pink microbial biofilm communities found in the mine runoff provide perfect research specimens because they have fewer organisms than most communities found in nature. The reason, Hettich noted, is that these environmental conditions - a low pH of 0.8 are way too extreme for most organisms to survive. A pH level of 7 is considered neutral and most proteins prefer pH levels between 5 and 7. In addition, the water from the mine often exceeds 120 degrees Fahrenheit. Because of their simpler makeup, the Banfield Laboratory established these communities as a model system in the mid 90s.

This latest publication builds upon research that was published in May 2005 by Science. In that paper, Banfield, Hettich and colleagues at ORNL describe the bacteria community that thrives in what amounts to sulphuric acid. Their work set the stage for the latest development because it provided the first large-scale proteome dataset for a real life microbial community with a limited number of members.

Of particular interest to DOE is how this effort relates to its Genomes to Life program, which is focused on identifying and characterizing the molecular machines of life. This study helps extend the initial studies of microbial isolates growth in carefully controlled laboratory settings to more real-world complicated microbial communities.

Funding for this project, which is in the second of five years, is provided by DOE’s Office of Science, Office of Biological and Environmental Research and by the National Science Foundation. UT-Battelle manages ORNL for DOE.

According to the Leader, Health Authorities were quite about the number of buildings in St George being tested for Legionnaire’s disease.

Air-conditioning cooling towers were being examined in the Kogarah and Rockdale municipalities after two residents contracted the infection.

A man in his early 40s and a woman in her 70s are being treated for the illness in St George Hospital.

The woman was in a serious but stable condition on Monday. The man was listed as being stable.

Legionnaire’s is an infection of the lungs (pneumonia) caused by Legionella bacteria.

It can live in water sources including some air-conditioning systems. The disease can occur when people have breathed in mist from a contaminated cooling tower. The South Eastern Sydney and Illawarra Area Health Service expect to have results of the tests today.

Its public health unit has also been piecing together where the patients had been during the incubation period.

The pair was believed to have contracted the disease between the last week of March and the first week of April.

They were admitted to hospital last week.

Director of Public Health Mark Ferson said local emergency departments, GPs, pathology laboratories and chest and infectious diseases physicians had been warned to be on the lookout for any patients with pneumonia-like symptoms and to test for legionella.

”There have been two cases confirmed and, while this is not an unusually high number, both cases had onset dates around the same time and the patients all live in and frequent the same geographical area,” Professor Ferson said.

”As part of the investigation and response we are working with local council officers.”

Majority of people recover from the illness, however some can become very ill with pneumonia and may die.

A medical epidemiologist from the Public Health Unit, Philippa Binns, would not confirm which buildings had been tested, or how many.
She would also not be drawn on information received by the Leader that the male patient is an employee of a licensed premise in Kogarah which the female patient was believed to have visited.

”The point we do want to make is that people need to be aware of the symptoms and, if concerned, should go to a doctor to get assessed,” Dr Binns said.

Dr Binns said there tended to be more cases at this time of year when the temperature varied and cooling systems were turned off and on.

Councils are required to carry out regular maintenance and testing of cooling towers.

A spokesman for Rockdale Council said the outbreak was not in its area.

A spokesman for Kogarah Council said that there were 12 cooling towers in building towers in its municipality.

Source

The Queensland Health Authority has sent out a notification that two visitors to a Gold Coast resort had been diagnosed with legionnaire’s disease which they had contracted after using the resort’s spa bath.

Michael Whitby from the Australian Medical Association Queensland said the legionella bug was readily found throughout the world in the environment, from Antarctica to jet engine oil, but it was most commonly found in water.

Major outbreaks had occurred in Australia such as the Melbourne Aquarium and majority of cases it has been associated with the cooling towers of large buildings that had not been properly maintained.

“They have a lot of metal fragments which provide iron as a substrate for legionella to grow. For legionella to get into your lungs it has to be in very small particle size so you have to actually spray them out of the air-conditioning system forming aerosols that ends up being inhaled,” Dr Whitby said.

The same applies in a spa where the spray created when water is expelled at high pressure forming aerosols which can make them a potential risk.

According to Linda Selvey, Queensland Health Senior Director of Population Health, “the mist provided a perfect avenue for bugs to make their way into lungs.”

“The big issue with spas is that the water is warmer so it provides a nice environment for bugs to live in,” Dr Selvey said. “Secondly, because you’re forcing air through the pipes at reasonably high pressures to get bubbles, you get a mist of water above the spa pool and you actually acquire legionella infection by breathing in the bugs.”

The ideal way to reduce bacterial growth and prevent infection was to empty spa pools once a month and physically cleans the filters and pipes with sanitizer. This physical scrubbing is critical to removing biofilms which can protect the organism during harsh environmental conditions.

There are several types of legionella, but the two that occur most commonly here are Legionella pneumophilia type 1 and legionella longbeachae. To find out if your spa is contaminated with legionella it is best to have the water them tested by Independant Microbiology Consultants which are NATA accredited and are experts in the field.

The cooling towers of an Uluru hotel have tested positive for legionella and may be the source of infection for a European tourist who has legionnaires’ disease.

A spokesman for Voyages Hotels and Resorts, which owns the Desert Gardens Hotel near Uluru, said routine testing of the cooling towers carried out last week returned a positive legionella reading.

The towers were in an area adjacent to the hotel.

“We were advised on Friday that a European male tourist has contracted legionnaires’ disease on a recent visit to Australia,” the spokesman said.

“He stayed in a number of different locations but one was the Desert Gardens Hotel.”

He said that at this stage there was no evidence the two events were linked, but further testing would be done to establish whether the strain found in the cooling towers was the same as that contracted by the tourist.

“We are working with the Department of Health to establish whether we can match the two,” he said.

“We have identified the person’s doctor and are trying to get in contact with that person … to do the matching.”

All staff and visitors to the hotel between February 20 and March 14 this year were being contacted to advise them of the test findings.

The spokesman said staff were more likely to have been exposed to any danger, as the cooling towers were in an area not regularly frequented by guests.

The cooling tower system in question had been closed off and decontaminated, and the hotel was awaiting the results of new tests to give the all clear.

“In the meantime, it’s off limits to all people,” the spokesman said.

He defended the hotel’s maintenance routine, saying testing of cooling towers was not mandatory in the Northern Territory.

“We test ours every month, without fail,” he said.

Source: The Age

Legionella was detected in a New Zealand Hospital in Christchurch. Health officials say the office-type water cooler filter may be the first case of its type in the world.

They are warning businesses to test office water cooler filters after the find.

Microbiological testing was done at the hospital last October after a patient showed symptoms of legionnaire’s disease and one of 14 office-style water coolers was found to have a “significant level” of legionella bacteria in a filter.

Canterbury District Health Board spokeswoman Michele Hider said the bacteria found in the water filter was different to the type that had affected the female patient and the testing had been done as a precaution. There was no evidence to suggest the water cooler was linked to any hospital patients or visitors becoming unwell.

The hospital acted as soon as the results were confirmed by removing the filter. The filter still had some months to go before its expiry date.

Canterbury medical officer of health Mel Brieseman said office water coolers and drinking water filters were not usually checked for legionella because the disease was generally contracted through aerosol spray.

“We believe this is the first case of significant levels of legionella being detected in a drinking water cooler anywhere in the world, so we will be publishing the findings as a scientific curiosity,” he said.

Dr Briesman warned that water filters needed to be changed regularly to prevent a build-up of a variety of bacteria, including legionella.

It was “standard advice” for people to use masks and gloves when handling potting mix to prevent legionellosis.

Small amounts of legionella occurred naturally in all untreated water supplies but could multiply to potentially harmful levels in the right conditions.

However, Dr Brieseman said the risk of ill health from drinking water containing significant amounts of legionella was considered low, compared with inhaling the bacteria as mist or steam.

Source

Background
E. coli and coliform bacteria have been used for a century as indicators of faecal pollution in water since they occur in large numbers in the gut of many mammals. While total coliforms are being removed from water quality guidelines, except as a measure of treatment efficacy, anecdotal reports from around the world and a handful of publications in the last ten years have suggested that even some strains of E. coli can grow to high density (> 10000 per 100 mL) in large lakes and storages. This provides a challenge for the manager’s of such water bodies to differentiate these “blooms” from a sudden input of faecal pollution.

The ecology of E. coli
Culture methods allow us to identify a bacterial species as a “dominant” member of the gut microbial consortium if it represents more than 1% of the cells capable of growth on MacConkey agar. In fish, frogs and reptiles E. coli only reaches this threshold in about 10% of animals. In native Australian birds it can be detected at this level in around 20% of individuals, and in about 50 % of native mammal hosts. In humans, E. coli can be detected in 95 to 100% of people.

Factors known to affect the prevalence of E. coli in host animals include climate (being more prevalent in grassland and temperate climes than the tropics or deserts), host diet, body size and gut morphology. Omnivores are more likely to carry E. coli in substantial numbers than herbivores with carnivores the least likely. Prevalence also increases with body mass and, interestingly, with increased human association. The ecological niche of E. coli can be summarized as the gut of warm-blooded animals that have a microbial fermentation chamber in their hindgut or have a body mass of greater than one kilogram.

E. coli genogroups or subspecies
E. coli are divided into four subgroups: A, B1, B2 and D based on a range of factors including genetics, phenotype and ecology. Group A and B1 strains occur in all vertebrate hosts and in water; Group B2 strains are found in warm-blooded vertebrates with hindgut fermentation; Group D strains are found in warm-blooded vertebrates. In general, A and B1 strains appear to be generalists, acquired by their hosts from the environment, and which colonize well but persist poorly. B2 and D strains, which encode the most virulence factors, appear to be acquired from other host animals, colonize poorly but persist well. The distribution of the subgroups in human populations varies in different parts of the world. The prevalence of subgroups in humans may change with age in population and there appears to be a gender effect. In water, B1 strains are by far the most dominant, with B2 and D strains rarely found. Interestingly, B1 strains have similar sugar utilization patterns and optimal growth temperatures whether isolated from water or faeces, while A strains differ in both these characteristics depending on their origin. B1 strains appear to survive the transition to the aquatic environment best, with B2 and D strains surviving relatively poorly in water. Exposure to the aquatic environment appears to select for a subset of group A strains.

Canberra: The lake, the bug, the issue
Lake Burley Griffin experiences coliform blooms on occasional basis, from late summer to early autumn, where confirmed coliform counts exceed acceptable levels and necessitate the closure of the lake to a range of recreational activities, often at substantial cost and inconvenience. These bloom events prompted an investigation of the lake’s coliform microbiology funded by the National Capital Authority. The research program has three main objectives:

Sampling program
Over the past two years Lake Burley Griffin has been regularly monitored during both dry and wet weather. During the summer months Lake Tuggeranong and Lake Ginninderra, two other recreational lakes in Canberra, were monitored weekly. To gain an understanding of the frequency and characteristics of Escherichia coli in the external environment soil, sediment and water samples were also collected from localities across Australia.

E. coli strain characteristics tested
All environmental samples were screened for the presence of E. coli in order to develop a strain database. The phenotypic characteristics of the strains were determined, e.g. their growth rates at a range of temperatures, as well as their genotypic characteristics, e.g. virulence factor profile.

Findings
The study’s major finding has been the clear identification of three strains of E. coli capable of survival in the external environment and which do not appear to require a host population. Two of the three strains type as Group A (strains 000 and 010) while the third types in Group B1 (strain 001). Two would be described as phenotypically “typical” E. coli while the B1 strain would be “very atypical”. Of interest is the fact that this strains 001 (B Group) gives a negative indole test, meaning that it may not confirm as an E. coli but rather be classified as a total or thermotolerant (“faecal”) coliform, depending on the method being used. These three strains have been responsible for all bloom events in
Lake Burley Griffin since April 2000. The bloom strains have also been found in Lake Burragorang, Sydney’s primary drinking water reservoir, and detected in other water bodies in the ACT. These strains can be detected in these water bodies outside of bloom events and the evidence suggests these strains have been responsible for blooms over the past 30 years in Australia. The main distinguishing feature of these bloom strains is their mucoid colony morphology (Figure 1).

Figure 1: Colony appearance of Klebsiella pneumoniae (top left) showing a typical mucoid appearance due to their Type 1 capsule, typical unencapsulated Escherichia coli (top right) and the three bloom strains (bottom).

Examination of the genes responsible for the mucoid appearance demonstrates that the bloom strains are unlikely to be detected in a human or animal host. These bloom E. coli also have none of the genes thought to enable bacteria to cause disease. A simple Restriction Fragment Length Polymorphism assay is able to readily distinguish the three strains (Figure 2). A more sophisticated Real-time PCR assay has been developed based on unique genome fragments in each strain to allow rapid, definitive confirmation of the bloom strains should they be suspected when
elevated counts occur.

Figure 2. RFLP analysis of the bloom strains from different sampling locations.

Use of the research findings
The Real-time PCR assay will now be used to determine whether elevated coliform counts in Lake Burley Griffin are due to one of the identified environmental E. coli strains enabling more informed decisions to be made concerning the extent to which recreational activities in the lake should be curtailed.

When is it likely to be a bloom rather than faecal pollution?
If faecal material is deposited in a water body it would be expected that a range of E. coli genotypes would be detected in the polluted water. The genotypes would have a heterogeneous spatial distribution and most of the genotypes isolated would be rarely identified. There should also be other faecal indicators present in elevated numbers, such as enterococci. On the other hand, if there is a bloom of coliform bacteria one would expect to see a limited range of genotypes amongst the isolates and the range of isolates would be consistent across the area of the bloom. One would not expect to find other faecal indicators.

Related research
This study demonstrates that in some cases elevated coliform counts may not be a result of faecal contamination. This outcome suggests that future research is required to identify more appropriate indicator organisms and that water quality standards need to be modified to include such exceptions to the indicator assumption. The coliform group is still used extensively as a water quality indicator. Many water bodies throughout the world are considered to have coliform counts above acceptable levels. In an effort to manage this problem, programmes are underway to develop methods that will allow the source of faecal contamination to be identified (Microbial Source Tracking, MST). The success of these efforts critically depend on a number of assumptions being valid and these assumptions need to be carefully articulated and worked through in such programs. There is some evidence that wastewater treatment processes may select for specific strains of E. coli. For example, one study showed that the dominant E. coli in a septic tank was not a dominant strain in the householders. A similar process may be taking place in large wastewater systems.

Water Testing Laboratory
Independent Monitoring Consultants
www.imclive.com

Authors:
Jane Littlefield-Wyer is a PhD candidate in the School of Botany and Zoology at the Australian National University. Jane has presented at the Australian Society of Microbiology meetings in September 2004 and 2005 and at the 2006 annual meeting of the Society for General Microbiology.

David Gordon is an Associate Professor in the School of Botany and Zoology at the Australian
National University. David presented a seminar for the US Environmental Protection Agency in 2003 and attended a three-day workshop held by the Water Environment Research Foundation on Microbial Source Tracking in Texas 2005. The finding of this research have been published in the primary scientific literature and presented at both national and international conferences.

Acknowledgments
The Australian National University (ANU) would like to thank the Australian Government, represented by the National Capital Authority (NCA) for requesting the ANU to carry out this research based on samples from Lake Burley Griffin, Canberra. The NCA’s initiative in providing funding support and professional assistance to this research has been invaluable in this critical work. The Sydney Catchment Authority sponsored David and Jane to visit Sydney and present their findings on the 19th April 2006. That evening the NSW Branch of the Australian Society for Microbiology sponsored an evening seminar on the ecology of E. coli and the blooming strains at Macquarie University, hosted by Dr Martin Slade.0