Seroprevalence, isolation and co-infection of multiple Toxoplasma gondii strains in individual bobcats (Lynx rufus) from Mississippi, USA. Issue 5 (April 2017)

• Record Type: Journal Article
• Authors: Verma, Shiv K.; Sweeny, Amy R.; Lovallo, Matthew J.; Calero-Bernal, Rafael; Kwok, Oliver C.; Jiang, Tiantian; Su, Chunlei; Grigg, Michael E.; Dubey, Jitender P.
• Is Part Of: International journal for parasitology. Volume 47:Issue 5(2017)
• Page Start: 297
• Page End: 303
• Publication Date: 2017-04
• Subjects: Toxoplasmosis -- Felids -- Bioassay -- Isolation -- Strain -- Genotype; Parasitology -- Periodicals; Parasitology -- Periodicals; Parasitologie -- Périodiques; Parasitology; Periodicals; Electronic journals; 571.999
• DOI: 10.1016/j.ijpara.2016.12.007
• Languages: English
• ISSNs: 0020-7519

Abstract

Graphical abstract: Highlights: Felids are essential for the spread and diversification of Toxoplasma in nature. A high percentage of bobcats ( Lynx rufus ) are infected with Toxoplasma gondii in the USA. We provide the first known direct evidence for multiple strain co-infection in a natural felid host. Among naturally co-infected bobcats, a diverse array of genotypes were identified that partitioned to different organs. Abstract: Toxoplasma gondii causes lifelong chronic infection in both feline definitive hosts and intermediate hosts. Multiple exposures to the parasite are likely to occur in nature due to high environmental contamination. Here, we present data of high seroprevalence and multiple T. gondii strain co-infections in individual bobcats ( Lynx rufus ). Unfrozen samples (blood, heart, tongue and faeces) were collected from 35 free ranging wild bobcats from Mississippi, USA. Toxoplasma gondii antibodies were detected in serum by the modified agglutination test (1:≥200) in all 35 bobcats. Hearts from all bobcats were bioassayed in mice and viable T. gondii was isolated from 21; these strains were further propagated in cell culture. Additionally, DNA was extracted from digests of tongues and hearts of all 35 bobcats; T. gondii DNA was detected in tissues of all 35 bobcats. Genetic characterisation of DNA from cell culture-derived isolates was performed by multiplex PCR using 10 PCR-RFLP markers. Results showed that ToxoDB genotype #5 predominated (in 18 isolates) with a few other types (#24 in two isolates, and #2 in one isolate). PCR-DNA sequencing at two polymorphic markers, GRA6 and GRA7, detected multiple recombinant strains co-infecting the tissues of bobcats; most possessing Type II alleles at GRA7 versus Type X (HG-12) alleles at GRA6. Our results suggest that individual bobcats have been exposed to more than one parasite strain during their life time.