Non-tuberculous Mycobacterium species causing mycobacteriosis in farmed aquatic animals of South Africa

Abstract

BackgroundMycobacteriosis caused by non-tuberculous mycobacteria (NTM), is among the most chronic diseases of aquatic animals. In addition, fish mycobacteriosis has substantial economic consequences especially in the aquaculture and fisheries industry as infections may significantly decrease production and trade. Some fish NTM pathogens are highly virulent and zoonotic; as such, infection of aquaria with these pathogens is a public health concern.In this study, we report isolation of nine different NTM species from sixteen aquatic animals including different fish species, frogs and a crocodile. Given the clinical significance of Mycobacterium marinum and its close relation to Mycobacterium tuberculosis, as well as the significance of ESAT 6 and CFP-10 secretion in mycobacterial virulence, we analysed the esxA and esxB nucleotide sequences of M. marinum isolates identified in this study as well as other mycobacteria in the public databases.ResultsMycobacterium shimoidei, Mycobacterium marinum, Mycobacterium chelonae, Mycobacterium septicum /M. peregrinum and Mycobacterium porcinum were isolated from gold fish, Guppy, exotic fish species in South Africa, koi and undefined fish, Knysna seahorse, as well Natal ghost frogs respectively, presenting tuberculosis like granuloma. Other NTM species were isolated from the studied aquatic animals without any visible lesions, and these include Mycobacterium sp. N845 T, Mycobacterium fortuitum, a member of the Mycobacterium avium complex, and Mycobacterium szulgai. Phylogenetic analysis of mycobacteria, based on esxA and esxB genes, separated slow growing from rapidly growing mycobacteria as well as pathogenic from non-pathogenic mycobacteria in some cases.ConclusionsIsolation of the different NTM species from samples presenting granuloma suggests the significance of these NTM species in causing mycobacteriosis in these aquatic animals. The study also revealed the potential of esxA and esxB sequences as markers for phylogenetic classification of mycobacteria. Observations regarding use of esxA and esxB sequences for prediction of potential pathogenicity of mycobacteria warrants further investigation of these two genes in a study employing NTM species with well-defined pathogenicity.

In the Wake of the Ongoing Mass Mortality Events: Co-occurrence of Mycobacterium, Haplosporidium and Other Pathogens in Pinna nobilis Collected in Italy and Spain (Mediterranean Sea)

“…(1) the Mycobacterium tuberculosis complex (MTBC) including species that are pathogenic to humans, wild and domesticated mammals (M. tuberculosis, M. bovis, M. africanum) which cause Tuberculosis (TB); and (2) Non-Tuberculous Mycobacteria (NTM), consisting on free-living organisms, ubiquitous in the environment and saprophytic habit and that can cause a wide range of infections both in humans and animals from different environments (Porvaznik et al, 2017;Honda et al, 2018). NTM infections are among the most common chronic disease of aquatic animals (Gcebe et al, 2018). In the aquatic environment, at present, there are over 167 species of freshwater and marine fishes described as susceptible to Mycobacteria (Bruno et al, 1998;Jacobs et al, 2009).…”

Isolation, identification and associated risk factors of non‐tuberculous mycobacteria infection in humans and dromedary camels in Samburu County, Kenya

“…(2018). Mycobacterium szulgai is a potential human and animal pathogen with manifestation similar to active TB clinically and on radiography (Gcebe et al., 2018; Kim et al., 2014). There were several species in the Fortuitum‐Vaccae clade with M. fortuitum being the most common isolate of medical importance, in both study populations.…”

“…Also, several NTM isolated from livestock are potentially zoonotic (Mbugi et al, 2012; Mengistu & Enquselassie, 2014; Thoen, LoBue, & Enarson, 2014). These NTM for instance M. marinum , M. ulcerans , M. fortuitum , M. chelonae , M. peregrinum , M. kansasii , M. abscessus , M. intracellulare and Mycobacterium avium complex (MAC) are either true or opportunistic pathogens of humans (Gcebe, Michel, & Hlokwe, 2018; Nishiuchi, Iwamoto, & Maruyama, 2017). These NTM species are often found in the environment as biofilm formation, free‐living or in association with amoeba (Nishiuchi et al., 2017).…”

“…However, information on the zoonotic significance of NTM, diagnostic implications in both humans and animals, as well as the impact on the management of human TB in developing countries is scanty (Gcebe & Hlokwe, 2017; Hoza, Mfinanga, Rodloff, Moser, & Konig, 2016). Some of the important NTM species isolated from animals include M. avium intracellulare complex ( M. avium subspecies avium , M. avium paratuberculosis ), M. marinum , M. shimoidei , M. chelonae , M. septicum , M. porcinum , M. lentiflavum , M. fortuitum , M. peregrinum , M. gordonae , M. neoaurum , M. parafortuitum , M. moriokaense and M. confluentis (Batista et al., 2017; Gcebe et al., 2018; Katale et al., 2014; Nuru et al., 2017). The members of this genus that have been isolated from tissue lesions and milk of camelids include M. tuberculosis , M. bovis , M. pinnipedii , M. caprae , and M. microti , as well as, atypical mycobacteria such as M. Kansasii (Beyi, Gezahegne, Mussa, Ameni, & Ali, 2014; García‐Bocanegra et al, 2010; Wernery & Kinne, 2012).…”

Biomarkers for Detecting Resilience against Mycobacterial Disease in Animals

“…These bacteria include the M. avium complex (MAC) and the M. terrae complex which survive in environmental niches (18). NTM have on September 29, 2019 at UNIVERSITY OF TECH SYDNEY http://iai.asm.org/ Downloaded from also been identified in fisheries leading to general and chronic mycobacteriosis, highlighting the widespread nature and the variety of mycobacterial species present in a range of environments (19).…”