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

Abstract

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.

Modification of the Folmer primers for the cytochrome c oxidase gene facilitates identification of mosquitoes

“…After discarding the ethanol, the mosquito was rinsed in fresh 1× PBS four times and homogenized with 400 µl of 1× PBS using three zirconia beads in a Precellys 24 lysis and homogenization instrument (Bertin Instruments, France) set at 5000 rpm for 15 s as described [ 36 ]. Homogenates were stored at −20 °C until DNA extraction using the High Pure PCR Template Preparation Kit (Roche Diagnostics, Indianapolis, IN, USA) as described previously [ 46 , 47 ].…”

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

“…Between July 2019 and March 2020, feral swine (n = 276) were trapped at a 4515-hectare privately-owned land in Bullock County in Alabama as described [ 32 ]. The property lies within the Upper Coastal Plain physiographic region.…”

“…The High-Pure PCR Template Preparation Kit (Roche Diagnostics, Indianapolis, IN USA) was used to extract total nucleic acids from whole blood according to the manufacturer’s instructions and described previously [ 11 , 32 ]. In brief, whole blood (400 µL) was mixed with equal volume of binding buffer followed by homogenization and digestion with proteinase K (10% of total volume).…”