The detection of Bifidobacterium adolescentis by colony hybridization as an indicator of human faecal pollution

Bifidobacteria are one of the most common bacterial types found in the intestines of humans and other animals and may be used as indicators of human fecal pollution. The presence of nine human-related Bifidobacterium species was analyzed in human and animal wastewater samples of different origins by using species-specific primers based on 16S rRNA sequences. Only B. adolescentis and B. dentium were found exclusively in human sewage. A multiplex PCR approach with strain-specific primers was developed. The method showed a sensitivity threshold of 10 cells/ml. This new molecular method could provide useful information for the characterization of fecal pollution sources.

supporting

confidence: 93%

Multiplex PCR with 16S rRNA Gene-Targeted Primers of Bifidobacterium spp. To Identify Sources of Fecal Pollution

Bonjoch

Blanch

2004

“…Previous research has proposed that the genus Bifidobacterium be used to indicate the origin of fecal pollution (14,15). This genus fulfills most of the requirements for being a fecal indicator.…”

Section: Discussionmentioning

confidence: 99%

Use of Bifidobacterium dentium as an Indicator of the Origin of Fecal Water Pollution

Nebra

Bonjoch

Blanch

2003

A new, simple, and specific protocol to discriminate between human and animal fecal pollution is described. The procedure is based on the detection of certain Bifidobacterium species in the samples. Two 16S rRNA gene-targeted probes are described. One of these probes (BDE) has as its target a region of the 16S rRNA gene of Bifidobacterium dentium, a Bifidobacterium species of exclusively human origin. The other probe (BAN) is based on the sequence of a region of 16S rRNA gene for several Bifidobacterium species related with animal origins. The specificity of both probes was evaluated by using 24 Bifidobacterium species, and their threshold detection limit was established by DNA-DNA hybridization. DNA-DNA hybridization with the BDE probe showed it to be specific for B. dentium, whereas that with the BAN probe showed it to be specific for B. animalis, B. asteroides, B. coryneforme, B. cuniculi, B. globosum, B. magnum, B. minimum, and B. subtile. A simple and specific protocol was also developed for the detection of their target species in environmental samples (sewage and feces). DNA-DNA hybridization with the BAN probe was only positive for samples from cattle and goats. Thus, this probe is not suitable for the identification of any animal fecal pollution. Whereas all samples with human fecal pollution showed a positive DNA-DNA hybridization result with the BDE probe, none of those with animal fecal pollution did. Therefore, this finding supports the potential use of this probe in detecting fecal pollution of human origin.

“…PCRbased detection and quantification methods using species-specific 16S rRNA gene-based primers are gradually becoming common in the identification of bifidobacteria. Several papers have described molecular methods for the identification of bifidobacterial isolates from selective plates (14,17,18). However, those approaches do not eliminate concerns about bias caused by inefficient recovery when culture-based methods are used.…”

Section: Bifidobacterial Quantification By Gc-16smentioning

confidence: 99%

Selective Plating Underestimates Abundance and Shows Differential Recovery of Bifidobacterial Species from Human Feces

Apajalahti¹,

Kettunen²,

Nurminen³

et al. 2003

The aim of the present work was to compare the efficacies and levels of selectivity of different culturedependent and -independent methods for analyzing bifidobacteria in human stool samples. The three different culture media used here significantly differed from each other, particularly with regard to the recovery of Bifidobacterium adolescentis. Bifidobacterium medium failed to recover B. adolescentis; Beerens medium recovered some B. adolescentis organisms (17% of total bifidobacteria), whereas tomato-Eugon medium recovered mainly B. adolescentis organisms (58% of total bifidobacteria). A culture-independent method that combines GC fractionation of bacterial community DNA and 16S rRNA sequencing indicated that B. adolescentis organisms accounted for 85% of all bifidobacteria. Methodological biases, such as those described in this paper, should be taken into account in interpreting earlier studies and designing future experiments.