NANOFIBERS FROM POLYVINYL ALCOHOL AND CAN ENLARGE THE SET OF TRAPPED ODOROLOGICAL TRACES

We tested collecting abilities of nanofibers made from polyvinyl alcohol and calcofluor (PVAC) for odorological trace collection. Our study revealed that spectrum of odorological traces trapped on nanofibrous PVAC absorbent is more stable and reproducible compared to commonly used ARATEXTM. In addition, both PVA and PVAC nanofibers can adhere a large number of traces undetectable by ARATEX.  Our results show that functionalization of commonly used absorbent ARATEXTM with PVA and PVAC nanofibers can vastly increase the accuracy of trace collection and, thus, significantly improve the forensic investigation

Two Populations of Mites (Tyrophagus putrescentiae) Differ in Response to Feeding on Feces-Containing Diets

Background:Tyrophagus putrescentiae is a ubiquitous mite species in soil, stored products and house dust and infests food and causes allergies in people. T. putrescentiae populations harbor different bacterial communities, including intracellular symbionts and gut bacteria. The spread of microorganisms via the fecal pellets of T. putrescentiae is a possibility that has not been studied in detail but may be an important means by which gut bacteria colonize subsequent generations of mites. Feces in soil may be a vector for the spread of microorganisms.Methods: Extracts from used mite culture medium (i.e., residual food, mite feces, and dead mite bodies) were used as a source of feces-inhabiting microorganisms as food for the mites. Two T. putrescentiae populations (L and P) were used for experiments, and they hosted the intracellular bacteria Cardinium and Wolbachia, respectively. The effects of the fecal fraction on respiration in a mite microcosm, mite nutrient contents, population growth and microbiome composition were evaluated.Results: Feces from the P population comprised more than 90% Bartonella-like sequences. Feces from the L population feces hosted Staphylococcus, Virgibacillus, Brevibacterium, Enterobacteriaceae, and Bacillus. The mites from the P population, but not the L population, exhibited increased bacterial respiration in the microcosms in comparison to no-mite controls. Both L- and P-feces extracts had an inhibitory effect on the respiration of the microcosms, indicating antagonistic interactions within feces-associated bacteria. The mite microbiomes were resistant to the acquisition of new bacterial species from the feces, but their bacterial profiles were affected. Feeding of P mites on P-feces-enriched diets resulted in an increase in Bartonella abundance from 6 to 20% of the total bacterial sequences and a decrease in Bacillus abundance. The population growth was fivefold accelerated on P-feces extracts in comparison to the control.Conclusion: The mite microbiome, to a certain extent, resists the acquisition of new bacteria when mites are fed on feces of the same species. However, a Bartonella-like bacteria-feces-enriched diet seems to be beneficial for mite populations with symbiotic Bartonella-like bacteria. Coprophagy on the feces of its own population may be a mechanism of bacterial acquisition in T. putrescentiae

Differential allergen expression in three Tyrophagus putrescentiae strains inhabited by distinct microbiome

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152656/1/all13921.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152656/2/all13921_am.pd

Rickettsia Phylogenomics: Unwinding the Intricacies of Obligate Intracellular Life

BACKGROUND: Completed genome sequences are rapidly increasing for Rickettsia, obligate intracellular alpha-proteobacteria responsible for various human diseases, including epidemic typhus and Rocky Mountain spotted fever. In light of phylogeny, the establishment of orthologous groups (OGs) of open reading frames (ORFs) will distinguish the core rickettsial genes and other group specific genes (class 1 OGs or C1OGs) from those distributed indiscriminately throughout the rickettsial tree (class 2 OG or C2OGs). METHODOLOGY/PRINCIPAL FINDINGS: We present 1823 representative (no gene duplications) and 259 non-representative (at least one gene duplication) rickettsial OGs. While the highly reductive (approximately 1.2 MB) Rickettsia genomes range in predicted ORFs from 872 to 1512, a core of 752 OGs was identified, depicting the essential Rickettsia genes. Unsurprisingly, this core lacks many metabolic genes, reflecting the dependence on host resources for growth and survival. Additionally, we bolster our recent reclassification of Rickettsia by identifying OGs that define the AG (ancestral group), TG (typhus group), TRG (transitional group), and SFG (spotted fever group) rickettsiae. OGs for insect-associated species, tick-associated species and species that harbor plasmids were also predicted. Through superimposition of all OGs over robust phylogeny estimation, we discern between C1OGs and C2OGs, the latter depicting genes either decaying from the conserved C1OGs or acquired laterally. Finally, scrutiny of non-representative OGs revealed high levels of split genes versus gene duplications, with both phenomena confounding gene orthology assignment. Interestingly, non-representative OGs, as well as OGs comprised of several gene families typically involved in microbial pathogenicity and/or the acquisition of virulence factors, fall predominantly within C2OG distributions. CONCLUSION/SIGNIFICANCE: Collectively, we determined the relative conservation and distribution of 14354 predicted ORFs from 10 rickettsial genomes across robust phylogeny estimation. The data, available at PATRIC (PathoSystems Resource Integration Center), provide novel information for unwinding the intricacies associated with Rickettsia pathogenesis, expanding the range of potential diagnostic, vaccine and therapeutic targets