Escherichia coli O157:H7 can enter into a viable but nonculturable (VBNC) state under stress conditions. Pathogens in this dormant state may escape detection if conventional methods are employed, and potentially pose serious threats to human health. Studies have shown that many intervention and preservation processes that are commonly used in the food industry may instead induce a VBNC state rather than kill the intended pathogens. This study aimed to detect whether E. coli O157:H7, an important and dangerous foodborne pathogen, could adapt to the stress caused by lactic acid exposure by entering the VBNC state. A propidium monoazide (PMA) quantitative PCR (qPCR) method was used for detection and quantifi cation of VBNC E. coli O157:H7 cells. The performance of this PMA-qPCR method was assessed using pure culture and ground beef samples inoculated with VBNC E. coli O157:H7 cells. The applied assay could detect as low as 103 CFU/mL VBNC E. coli O157:H7 in pure culture and 4 × 104 CFU/g VBNC cells in ground beef. Results indicate that PMA qPCR could accurately quantify E. coli O157:H7 in a VBNC state.

The species Canthon (Peltecanthon) staigi is a Neotropical “dung beetle” from Brazilian Atlantic Rainforest, which plays a key ecological role reallocating organic material and in some cases being a seed disperser. Moreover, this species is considered a bio indicator once is sensible to environment changes like the habitat loss. Despite its’ ecological importance nothing is known regarding the population structure of this dung beetle species. Molecular markers are informative tools to evaluate the extent and distribution of genetic diversity of the C. (P.) staigi populations remaining. Here we report the isolation and characterization of the first microsatellite markers for C. (P.) staigi. Four polymorphic microsatellite loci were characterized with allele numbers ranging from four to five per locus. The observed and expected heterozygosis ranged from 0.466 to 0.516 and 0.485 to 0.623, respectively. All loci were observed on Hardy Weinberg equilibrium. Linkage disequilibrium was not detected in any loci. From a subset of 24 loci it was observed positive transferability of six loci on four different tribes of Scarabaeidae. The loci will be used for studying population genetic structure of C. (P.) staigi and the cross-species amplification success extends the utility of these markers to be applied also on related species.