PubMed | Lincoln University at Christchurch, Agresearch Ltd. and Institute of Environmental Science Research
Type: Journal Article | Journal: Pathogens (Basel, Switzerland) | Year: 2014
Listeria monocytogenes is an organism associated with a wide range of foods. It causes listeriosis, a severe illness that mainly affects people with weakened immune systems. Proteomic profiles of three different L. monocytogenes isolates were studied using 1D SDS PAGE, 2DE and mass spectrometry. The protein banding patterns generated by 1D SDS PAGE of three strains of L. monocytogenes were found to be similar. Visual observations from 2DE gel maps revealed that certain spots appeared to have intensity differences. Key differences in proteins synthesis of three strains of L. monocytogenes were found using the PDQest TM 2DE Analysis software. Comparison showed that the clinical isolate (strain SB92/844) had 53.4% and 53.9% protein profile similarity with dairy isolate (strain V7) and seafood isolate (SB92/870), respectively. The identity of selected protein spots was achieved using MALDI-TOF and ion trap mass spectrometry. It was found that certain identified proteins (i.e., a major cold shock protein and superoxide dismutase) were expressed differently between two local strains of L. monocytogenes (SB92/844, SB92/870) and one strain from overseas (V7).
PubMed | National Health Research Institute and Institute of Environmental Science & Research
Type: Journal Article | Journal: Journal of clinical microbiology | Year: 2014
The etiology of an outbreak of gastroenteritis in humans cannot always be determined, and 25% of outbreaks remain unsolved in New Zealand. It is hypothesized that novel viruses may account for a proportion of unsolved cases, and new unbiased high-throughput sequencing methods hold promise for their detection. Analysis of the fecal metagenome can reveal the presence of viruses, bacteria, and parasites which may have evaded routine diagnostic testing. Thirty-one fecal samples from 26 gastroenteritis outbreaks of unknown etiology occurring in New Zealand between 2011 and 2012 were selected for de novo metagenomic analysis. A total data set of 193 million sequence reads of 150 bp in length was produced on an Illumina MiSeq. The metagenomic data set was searched for virus and parasite sequences, with no evidence of novel pathogens found. Eight viruses and one parasite were detected, each already known to be associated with gastroenteritis, including adenovirus, rotavirus, sapovirus, and Dientamoeba fragilis. In addition, we also describe the first detection of human parechovirus 3 (HPeV3) in Australasia. Metagenomics may thus provide a useful audit tool when applied retrospectively to determine where routine diagnostic processes may have failed to detect a pathogen.
PubMed | Institute of Environmental Science & Research
Type: Journal Article | Journal: Journal of environmental quality | Year: 2010
Transport through the soil and vadose zone to groundwater of Escherichia coli, fecal coliforms, and Campylobacter spp. from pasturing of dairy cows was studied on two working dairy farms under a traveling irrigator and a center pivot system. Leachate was collected from 1.5 m depth using a large linear lysimeter over a period of 4 yr after rainfall or irrigation applied using a traveling irrigator. There was little transport of fecal coliforms or Campylobacter from irrigation applications of 55 mm. There was some transport of fecal coliforms at applications of 80 mm (corresponding to irrigation plus heavy rainfall) but no detectable Campylobacter. When fresh cow pats were placed on half of the lysimeter plots with an 80-mm water application, there was transport of fecal coliforms and Campylobacter, but levels of Campylobacter were low (