Full history is in the project description, but briefly- a team of other veterinarians/colleagues and myself have stumbled across a case of multiple animals that have similar symptoms and are co-housed. Their presentation suggests an infectious disease, but no known infectious agent could be found despite thorough work-up. However, cytology samples from clean aspirates of subcutaneous nodules and urine filtrate (they have bloody urine) seems to be showing repeated structures that do not appear mammalian in origin. We seek to understand if these structures are some type of very organized artifact, or if they instead suggest that there may be some very unusual/novel type of organism (Annelid or Polychaete esp.) causing/involved-in these animals illnesses. Thank you for your time!
@ Matthew B Paddock; Thanks for your reply. We did attempt 16s sequencing of a tissue sample taken from one of the subcutaneous nodules (before we realized that there could be a eukaryote involved). The 16S sequencing (from RNA extracted from tissue blocks from what should have been a surgically sterile site) did show a mixture of many bacterial species. However, the profile wasn't anything that would suggest a relative of a known pathogen, nor did it suggest surface contamination (ie- no staph species etc..) The profile didn't have any one main dominant species either, but was 20% this, 18% that, 15% this etc.... I don't have the profile in front of me right now, but, from memory, the bacterial species in the tissue sample were unusual, with an overrepresentation of extremophiles. At first I interpreted this as potentially some species that might be surviving our autoclaving of instruments (ie- could tolerate the autoclave temperatures but not typically mammalian pathogens so were not the cause of disease in the animals). But, once the observation of the filaments/worm-like organisms was made, it did occur to me to that perhaps if the infection were eukaryotic, perhaps the profile of bacteria seen could reflect the composition of the microbiome of the putative novel parasite. I cross-referenced the profile of bacteria with the known microbiome profile of c-elegans and, though not an exact match, the proportions and types of bacterial species represented did suggest that perhaps the species identified could represent the bacterial population of some eukaryotic species. Our first thought was that the putative novel species was some type of nematode/filarial infection. We did attempt to have the tissue sample probed with nematode-specific 18S rRNA primers to see if we could amplify/sequence any nematode DNA. Interestingly, the primers did bind and amplify a target sequence, but when that was attempted to be sequenced, the PCR products were not clean enough to yield an identifiable species. Later, other microscopic findings led us to consider other phyla (beyond nematodes/trematodes). Since this is mostly a project done out of curiosity rather than our primary line of work, we have not had the budget to proceed with any additional PCR studies. If you would like to see the actual genus/species break-down for the 16S analysis, I'd be happy to dig it up and post it for you (just don't have access to that computer today).
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