Nested Polymerase Chain Reaction Assay for Detection of Mycobacterium shottsii and M. pseudoshottsii in Striped Bass

Abstract

Wild striped bass Morone saxatilis in Chesapeake Bay are experiencing a high prevalence of mycobacteriosis, which produces granulomatous lesions of the skin and visceral organs. Culture-based studies have indicated that the newly described species Mycobacterium shottsii and M. pseudoshottsii are the dominant isolates from diseased fish. The classical fish pathogen M. marinum is also found, albeit at much lower frequencies. Both M. shottsii and M. pseudoshottsii are extremely slow-growing on standard selective media, and up to 12 months may be required for isolation and characterization. Epidemiological studies of mycobacteriosis in Chesapeake Bay would therefore benefit from rapid molecular assays with which to detect these species in fish. In this paper, we describe the development of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays capable of detecting M. shottsii, M. pseudoshottsii, and, in most instances, coinfections thereof in striped bass tissues. In addition, PCR-RFLP assays were designed to detect M. marinum and other as-yet-undescribed Mycobacterium spp. present in Chesapeake Bay striped bass. Comparison of these molecular assays with culture-based techniques using splenic tissue from wild striped bass yielded generally concordant results and demonstrated the applicability of these techniques to the study of wild fish.

Draft Genome Sequence of the Fish Pathogen Mycobacterium pseudoshottsii Strain JCM15466, a Species Closely Related to M. marinum

“…They are pleomorphic, Gram-positive, acid-fast, nonmotile, nonsporulating, and rod shaped ( 1 ). The genus Mycobacterium currently contains 148 recognized species, including M. marinum , M. pseudoshottsii , and an unidentified Mycobacterium sp., which are the most commonly reported bacterial fish pathogens ( 2 ). Some are also zoonotic, causing cellulitis, skin tuberculosis, and foreign body reaction in humans ( 3 ).…”

Immunohistochemical and Taqman real-time PCR detection of mycobacterial infections in fish

“…In most cases, the disease is systemic, with spleen and kidney as primary target organs (Bruno, Griffiths, Mitchell, Wood, Fletcher, Drobniewski & Hastings 1998). External clinical signs are non‐specific and include scale loss, skin ulceration, emaciation, pigment changes and spinal defects (Noga, Wright & Pasarell 1990; Roberts 2001; Gauthier, Vogelbein, Rhodes & Reece 2008). In many investigations of fish mycobacteriosis, isolation of the pathogen is not attempted.…”

“…In many investigations of fish mycobacteriosis, isolation of the pathogen is not attempted. Indeed, traditional identification of mycobacteria based on cultural and biochemical tests may take several weeks, and even then a precise identification may not be arrived at (Austin & Austin 1999; Gauthier et al. 2008; Pourahmad, Thompson, Adams & Richards 2009).…”

Mycobacterial infection in Northern snakehead (Channa argus) from the Potomac River catchment

“…); m23.12f and m2311r (Gauthier et al . ); Tb11 and tb12 (Ringuet et al . ); and MF and MR (Kim et al .…”