Diversity of Bacterial Biofilm Communities on Sprinklers from Dairy Farm Cooling Systems in Israel

<div><p>On dairy farms in hot climates worldwide, cows suffer from heat stress, which is alleviated by the use of water cooling systems. Sprinklers and showerheads are known to support the development of microbial biofilms, which can be a source of infection by pathogenic microorganisms. The aim of this study was to investigate the presence of microbial biofilms in dairy cooling systems, and to analyze their population compositions using culture-independent technique, 16S rRNA gene sequencing. Biofilm samples were collected on eight dairy farms from 40 sprinklers and the microbial constituents were identified by deep sequencing of the 16S rRNA gene. A total of 9,374 operational taxonomic units (OTUs) was obtained from all samples. The mean richness of the samples was 465 ± 268 OTUs which were classified into 26 different phyla; 76% of the reads belonged to only three phyla: Proteobacteria, Actinobacteria and Firmicutes. Although the most prevalent OTUs (<i>Paracoccus</i>, <i>Methyloversatilis</i>, <i>Brevundimonas</i>, <i>Porphyrobacter</i>, Gp4, <i>Mycobacterium</i>, <i>Hyphomicrobium</i>, <i>Corynebacterium</i> and <i>Clostridium</i>) were shared by all farms, each farm formed a unique microbial pattern. Some known potential human and livestock pathogens were found to be closely related to the OTUs found in this study. This work demonstrates the presence of biofilm in dairy cooling systems which may potentially serve as a live source for microbial pathogens.</p></div

Rarefaction curves of 40 filter samples at a cutoff level of 3%.

<p>The rarefaction curve, plotting the number of observed OTUs (sharing ≥97% identity) as a function of the number of sequences, was computed using the RDP Pyrosequencing Pipeline Rarefaction tool.</p

Biofilm in the water sprinklers of dairy farm cooling systems.

<p>(a) Typical cooling system in the holding area of a milking parlor. Water sprinklers above the cows are used to soak/wet the cows. (b) Dismantled sprinkler and its filter. (c) Biofilm sampled from sprinkler filter stained with Acridine orange and visualized by epifluorescence microscopy or (d) cultured on blood agar. Scale bar for panel c is 20 μm.</p

Dairy farms and their microbial abundance.

<p>Names and locations (geographic coordinates) of the dairy farms and relative abundance of the most common phyla as revealed by 16S rRNA gene sequencing analysis. The map was constructed using ArcMap 10.0 software (Esri, Redlands, CA).</p

Parasitization by the wasp induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly -2

<p><b>Copyright information:</b></p><p>Taken from "Parasitization by the wasp induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly "</p><p>http://www.biomedcentral.com/1471-2164/9/342</p><p>BMC Genomics 2008;9():342-342.</p><p>Published online 18 Jul 2008</p><p>PMCID:PMC2488360.</p><p></p

Parasitization by the wasp induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly -3

Enclosing a translucent region, thus preventing direct contact with the host. (B) FISH of non-parasitized pupa with the primary symbiont (P) labeled with Cy3 (red) and (R) labeled with Cy5 (blue). (C) FISH of parasitized pupa by with (P) and (R) labeled as in B (after the wasp larva was dissected out). Note the higher concentration of labeled cells in the parasitized pupa compared to the non-parasitized one.<p><b>Copyright information:</b></p><p>Taken from "Parasitization by the wasp induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly "</p><p>http://www.biomedcentral.com/1471-2164/9/342</p><p>BMC Genomics 2008;9():342-342.</p><p>Published online 18 Jul 2008</p><p>PMCID:PMC2488360.</p><p></p

Phylogenetic analysis of different <i>Culicoides</i> species.

<p>Maximum likelihood phylogeny tree based on ITS-1 nucleotide sequences available in GenBank and 12 sequences obtained in this study (BE 1–6, NU 1–6). GenBank accession numbers are noted for each sequence. Bootstrap values are shown on the branches.</p

Geographic trap locations used in this study.

<p>Geographic trap locations used in this study.</p

Parasitization by the wasp induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly -1

Ne name.<p><b>Copyright information:</b></p><p>Taken from "Parasitization by the wasp induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly "</p><p>http://www.biomedcentral.com/1471-2164/9/342</p><p>BMC Genomics 2008;9():342-342.</p><p>Published online 18 Jul 2008</p><p>PMCID:PMC2488360.</p><p></p

Diagnostic PCR of ITS-1 for <i>Culicoides</i> species.

<p>Agarose gels showing PCR samples of 10 individual midges morphologically identified as <i>C. schultzei</i> complex (B1–5, N1–5) and 2 individuals of <i>C. imicola</i> (B6, N6). Same DNA samples were used for phylogeny analysis (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033610#pone-0033610-g003" target="_blank">Figures 3</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033610#pone-0033610-g004" target="_blank">4</a>). (A) Genus-specific PCR amplification (B) Species-specific PCR for identification of <i>C. oxystoma</i> (C) Species-specific PCR for identification of the other genetic cluster of <i>C. schultzei</i> complex. NC - negative control, containing no template; M - 100 bp DNA ladder.</p