Seasonal intestinal coccidiosis in wild bluegill Lepomis macrochirus is associated with a spring bacterial epizootic

Abstract

Wild bluegill, Lepomis macrochirus Rafinesque, succumb to seasonal mortality in the early spring during cool water temperatures, shown previously to be related to bacteraemia caused by a psychrotrophic bacterium, Pseudomonas mandelii. In the study herein, intestinal coccidiosis in wild bluegill had seasonal prevalence causing heavy intestinal infections and sloughing of intestinal epithelium occurring in late winter/early spring. Infections were predominantly related to two different species, Goussia washuti n. sp., an epicellular coccidium, and a coccidium closely resembling Goussia desseri Molnár 1996, previously only described in percid fish in Europe. In 2019, co‐infections of bacteraemia and intestinal coccidiosis occurred in bluegills. Evaluating coccidium infection intensity by fresh parasite examination and histology, an association was observed in which fish with moderate‐to‐heavy intestinal coccidiosis were 8–12 times more likely to have bacteraemia compared to fish with no or light coccidiosis. The association of these co‐infections suggests that intestinal coccidiosis could contribute to seasonal bacterial epizootics of wild bluegill.

Distinctive location of piscine intestinal coccidiosis in Asian seabass fingerlings

“…These severe infections aggravate epithelial injuries in the fishes and trigger epithelial cell desquamation and necrosis through direct cell burst from oocyst release and the inflammatory response [17,39]. Similar responses to the previous publications on coccidia infection in various fishes were reported [16,17,28,37]. Severe inflammation and mucosal damage are the lethal injuries that cause massive infected fingerling death.…”

“…[2,[12][13][14]. The pathogenicity of this disease depends on individual fish sensitivity, inflammatory responses, the enterocytes turnover rate, bacterial co-infection, low daily water exchange rates, and intestinal location [15,16]. Infections are associated with pathological changes in the intestinal tissues in the high-pathogenicity response in many fish species, such as denuded intestinal epithelium, intense inflammation, focal necrosis, intestinal epithelium, and mucoid casts containing parasite stages [2,16,17,18].…”

Mixed Eimeria and Cryptosporidium infection and its effects on pathology and clinical outcomes in juvenile Asian seabass (Lates calcarifer) cultured in Thailand

“…The association of intestinal coccidiosis contributing to secondary bacterial infection was reported by Lovy et al (2019). This might be explained by changes in intestinal environment, which contribute to changes in the balance between non-pathogenic and pathogenic bacteria that could result in an induction of secondary bacterial infection (Sitjà-Bobadilla et al, 2016).…”

“…These groups of protozoa are commonly host specific and usually reported as a single infection in various fish (El‐Mansy, 2008; Golomazou & Karanis, 2020). Mixed infections of the same genus with different species of coccidia are also described, such as genera Goussia (Lovy et al., 2019; Lovy & Friend, 2015), Cryptosporidium (Certad et al., 2015) and Eimeria (Paterson & Desser, 1982); however, there is no report about co‐infection of more than one genus in an individual fish.…”

Microscopic marine invertebrates are reservoirs for cryptic and diverse protists and fungi

“…The sequence found in annelids shares over 96% identity to Goussia ameliae, which was isolated from the pyloric caecum of landlocked alewives (Alosa pseudoharengus) and is not known to infect other hosts [47]. The chaetognath isolate is slightly more dissimilar (94.0% sequence identity) to the highest scoring reference sequence (Goussia washuti from wild bluegill, Lepomis macrochirus) [48] and likely represents an undescribed species. Finally, the molluscan sequence is closest to that of Goussia pannonica (99.2% sequence identity) from the blue bream (Abramis syn.…”