Sunlight inactivation of human polymerase chain reaction markers and cultured fecal indicators in river and saline waters.

Decay rates for sunlight inactivation of polymerase chain reaction (PCR) markers for total Bacteroidales, human-specific Bacteroidales, Escherichia coli, and Bifidobacterium adolescentis relative to cultured E. coli were investigated. The experiment used 100-L chambers of fresh water and seawater (paired with dark controls) seeded with human sewage and exposed to natural sunlight over three summer days.

Distinguishing human and possum faeces using PCR markers.

Specificity testing of two published polymerase chain reaction (PCR) markers for the detection of human faecal pollution, revealed 100% false-positive rates to brush-tailed possum faeces (n = 10), but low false-positive rates against other potential pollution sources. Cross-reaction with possums could be a problem with other human-specific markers; therefore, a possum PCR marker was developed for use in conjunction with human PCR markers. The possum PCR marker was based on Bacteroidales 16S ribosomal ribonucleic acid sequences, and was tested on 233 individual faecal samples from 11 other animal species.

Survival of Campylobacter spp. in bovine faeces on pasture.

Aims: To determine the survival on pasture of Campylobacter spp. naturally present in bovine faeces and compare this with a previously published study using laboratory-cultured Campylobacter spp.

Methods And Results: Ten freshly collected cow pats were deposited on pasture during summer, and Campylobacter spp.

Evidence for growth of enterococci in municipal oxidation ponds, obtained using antibiotic resistance analysis.

The Christchurch wastewater treatment plant uses a series of six oxidation ponds to reduce the bacterial load of treated effluent before it is discharged into the local estuary. To ensure that this discharge does not adversely affect water quality in the receiving environment, local regulations specify maximum levels in the discharge for a number of parameters, including enterococci. Between 2001 and 2006, regulations required fewer than 300 enterococci per 100 ml in summer.

A PCR marker for detection in surface waters of faecal pollution derived from ducks.

Detection of the faecal pollution contribution from wildfowl is an important adjunct in determining the sources of faecal pollution in waterways. This is particularly true, where human waste and other animal faecal sources have been eliminated as the pollution source. A polymerase chain reaction (PCR) marker was developed as a duck-specific marker of faecal pollution.

The use of chemical and molecular microbial indicators for faecal source identification.

Identifying the source of faecal pollution is important to enable appropriate management of faecal pollution of water. We are developing and evaluating a combination of these microbial and chemical indicators better able to identify the source of faecal pollution. These assays make use of a combination of direct PCR, culturing, and colony hybridisation to identify source specific species of Bifidobacterium, Rhodococcus and Bacteroides.