Retrospective analysis of the Zebrafish International Resource Center diagnostic data links Pseudocapillaria tomentosa to intestinal neoplasms in zebrafish Danio rerio (Hamilton 1822)

Pseudocapillaria tomentosa, Mycoplasmaspp., and intestinal lesions in experimentally infected zebrafishDanio rerio

“…Evidence suggests that both P. tomentosa and Mycoplasma E enhance development of the intestinal tumors commonly seen in zebrafish, including both in vivo laboratory experiments 6 , 10 , 11 , 12 and in retrospective evaluation of hundreds of diagnostic cases submitted to the ZIRC diagnostic service 8 . In regards to the nematode, it enhances both the incidence to intestinal cancer in fish exposed to a chemical carcinogen 6,10 and also shortens the time to onset of the tumors 12 .…”

“…Kent et al 6 reported an association of the intestinal cancers in zebrafish with P. tomentosa based on review of the data from a carcinogenesis study conducted by Spitsbergen et al 10 , where zebrafish exposed to both DMBA and P. tomentosa demonstrated a higher prevalence of intestinal tumors than uninfected fish exposed to this carcinogen. We recently conducted a retrospective study of the ZIRC database, and found a strong statistically significant association of the occurrence of the worms, by both case and submitting laboratories, with the cancers 8 . However, the worm is unlikely the primary cause because amongst the laboratories with the cancers, the worms were absent in 70% of the fish.…”

“…Similar to other capillarid nematodes, the worm invades intestinal tissues and cause severe inflammatory changes. The intestinal neoplasms and worms have occurred in about 17% and 15% of the facilities, respectively 8 . The high prevalence of these intestinal neoplasms underscores the importance in determining their cause and the role the worm may play with progression of these neoplasms.…”

Pseudocapillaria tomentosa,Mycoplasmaspp., and Intestinal Lesions in Experimentally Infected ZebrafishDanio rerio

“…Intestinal neoplasms and worms have occurred in about 17% and 15% of the facilities, respectively. 8 The retrospective surveys 3,8 also showed no correlations with sex or strain of fish, further supporting an infectious etiology. The high prevalence of these intestinal neoplasms underscores the importance in determining their cause and the role the worm may play with progression of these neoplasms.…”

“…We recently conducted a retrospective study of the ZIRC database and found a strong statistically significant association of the occurrence of the worms, by both case and submitting laboratories, with intestinal neoplasia. 8 However, the worm is unlikely the primary cause because among the laboratories with intestinal neoplasia, the worms were absent in 70% of the fish. In addition, Burns et al 11 reported that intestinal neoplasms could be transmitted in the absence of the worm by water borne exposure after about 9 months, and the disease was associated with a specific Mycoplasma strain related to Mycoplasma penetrans.…”