Cambaraspora faxoni n. sp. (Microsporidia: Glugeida) from native and invasive crayfish in the USA and a novel host of Cambaraspora floridanus.

Crayfishes are among the most widely introduced freshwater taxa and can have extensive ecological impacts. Knowledge of the parasites crayfish harbor is limited, yet co-invasion of parasites is a significant risk associated with invasions. In this study, we describe a novel microsporidium, Cambaraspora faxoni n. sp. (Glugeida: Tuzetiidae), from two crayfish hosts in the Midwest USA, Faxonius virilis and Faxonius rusticus. We also expand the known host range of Cambaraspora floridanus to include Procambarus spiculifer. Cambaraspora faxoni infects muscle and heart tissue of F. rusticus and develops within a sporophorous vesicle. The mature spore measures 3.22 ± 0.14 µm in length and 1.45 ± 0.13 µm in width, with 8-9 turns of the polar filament. SSU sequencing indicates the isolates from F. virilis and F. rusticus were identical (100%) and 93.49% similar to C. floridanus, supporting the erection of a new species within the Cambaraspora genus. The novel parasite was discovered within the native range of F. rusticus (Ohio, USA) and within a native congeneric (F. virilis) in the invasive range of F. rusticus (Wisconsin, USA). Faxonius virilis is invasive in other regions. This new parasite could have been introduced to Wisconsin with F. rusticus or it may be a generalist species with a broad distribution. In either case, this parasite infects two crayfish species that have been widely introduced to new drainages throughout North America and could have future effects on invasion dynamics or impacts.

Impacts of a large invasive mammal on water quality in riparian ecosystems.

Wild pigs (Sus scrofa) are a highly invasive species in many regions of the world and can act as ecosystem engineers in areas where they are established. In riparian ecosystems, wild pigs may affect water quality parameters and introduce fecal bacteria, although previous studies have reported conflicting results. We propose four conditions that we believe are needed for an accurate assessment of wild pig impacts on water quality and address each one in our study. Water samples were collected between May 2018 and June 2019 in riparian watersheds on a privately owned property in Alabama that was densely populated by wild pigs (treatment) and in watersheds at a nearby national forest without an established population. Samples were analyzed for concentrations of water quality parameters, such as anions and cations, dissolved oxygen, total suspended solids, N, dissolved organic C, and Escherichia coli and other fecal coliforms. An additional 38 samples were analyzed using quantitative polymerase chain reaction for swine fecal bacteroidetes. At treatment watersheds, specific conductivity and concentrations of organic N and C, SO4 2- , and Ca2+ were between 2 and 11 times that of reference watersheds. Escherichia coli values at treatment watersheds were 40 times reference watershed values. DNA from swine fecal bacteroidetes was detected in 70% of treatment samples and 0% of reference samples. Wild pigs are a threat to water quality in riparian areas, and our results indicate that it may be important to control populations upstream of major drinking water sources and recreational areas.

Peptide ELISA and FRET-qPCR Identified a Significantly Higher Prevalence of Chlamydia suis in Domestic Pigs Than in Feral Swine from the State of Alabama, USA.

Chlamydia suis is an important, highly prevalent, and diverse obligate intracellular pathogen infecting pigs. In order to investigate the prevalence and diversity of C. suis in the U.S., 276 whole blood samples from feral swine were collected as well as 109 fecal swabs and 60 whole blood samples from domestic pigs. C. suis-specific peptide ELISA identified anti-C. suis antibodies in 13.0% of the blood of feral swine (26/276) and 80.0% of the domestic pigs (48/60). FRET-qPCR and DNA sequencing found C. suis DNA in 99.1% of the fecal swabs (108/109) and 21.7% of the whole blood (13/60) of the domestic pigs, but not in any of the assayed blood samples (0/267) in feral swine. Phylogenetic comparison of partial C. suis ompA gene sequences and C. suis-specific multilocus sequencing typing (MLST) revealed significant genetic diversity of the C. suis identified in this study. Highly genetically diverse C. suis strains are prevalent in domestic pigs in the USA. As crowding strongly enhances the frequency and intensity of highly prevalent Chlamydia infections in animals, less population density in feral swine than in domestic pigs may explain the significantly lower C. suis prevalence in feral swine. A future study is warranted to obtain C. suis DNA from feral swine to perform genetic diversity of C. suis between commercial and feral pigs.

Molecular and Serological Prevalence of Leptospira spp. in Feral Pigs (Sus scrofa) and their Habitats in Alabama, USA.

Leptospirosis is a widespread zoonosis and has been recognized as a re-emerging infectious disease in humans and a variety of wild and domestic animal species. In order to understand the prevalence and diversity of Leptospira spp. in feral pig populations of Alabama, we trapped 315 feral pigs in Bullock County east-central Alabama, and collected 97 environmental samples from riparian areas in Bullock County and Macon County east-central Alabama. Two previously published PCRs followed by DNA sequencing and BLASTn were performed to identify pathogenic Leptospira species in the kidney of feral pigs (3.2%, 10/315) as well as environmental samples collected from the habitats of feral pigs (2.1%, 2/97), but not in the whole blood samples (n = 276) or spleen (n = 51). An ELISA determined that 44.2% of serum samples (122/276) were antibody-positive for Leptospira. The identification of two pathogenic Leptospira species from environmental samples and the high sero-positivity in feral pigs suggests potential pathogen shedding from feral pigs to environments, and to humans and domestic animals. In order to better understand the risk to human health associated with feral swine presence, further studies are warranted to explore the interrelationship between Leptospira spp. shedding in the urine of feral pigs and bacterial culture to explore pathogenicity. Multi-locus sequencing typing (MLST) and microscopic agglutination tests (MAT) should be performed in future studies to make a definite determination of pathogenic Leptospira in feral pigs in Alabama.