Bacterial Pathogens Isolated from Cultured Bullfrogs (Rana Castesbeiana)

Abstract

Abstract.A commercial bullfrog (Rana castesbeiana) operation in south Georgia had multiple epizootics of systemic bacterial infections over a 3-year period, 1998-2000. A number of potential pathogens (Aeromonas hydrophila, Chryseobacterium (Flavobacterium) meningosepticum, Chryseobacterium (Flavobacterium) indolgenes, Edwardsiella tarda, Citrobacter freundii, Pseudomonas spp., and (Streptococcus iniae) were isolated from various tissues. Clinically, frogs demonstrated acute onset of torticolis, stupor, and indifference to stimuli. Cutaneous hyperemia, subcutaneous and muscular hemorrhage, and peripheral edema were consistent gross findings. Histologically, clusters of lymphocytes, monocytes, and occasional acidophiles with scattered granulomas occurred in liver, kidney, and spleen. This is the first report of S. inae and C. meningosepticum as potential disease agents in R. castesbeiana. These findings suggest that a variety of bacteria may be associated with redleg and that culture results must be obtained for accurate diagnosis. Domestic farming of frogs is a growing industry, as the demand for frogs increases for use as pets, food, experimental animals, and educational tools. Farming operations require that frogs be placed in confinement and, as with many other species, this often leads to an increased risk of disease and mass mortality. 4 A commercial frog operation in southern Georgia experienced sporadic epizootics of bacterial sepsis (redleg) between 1998 and 2000. At the facility, juvenile frogs are maintained in aquaria with a continuous (once through) water spray system. As young adults, frogs are transferred to outdoor ponds and maintained until transferred to surrounding ponds or sold commercially. Frogs in both aquaria and ponds are kept at very high animal densities that vary with season and commercial demand. The frogs are fed bulk pelleted ration produced on site.A total of 17 representative live frogs were submitted for necropsy on 6 separate occasions. Upon submission for necropsy, frogs were given a routine physical examination and then euthanized by transdermal exposure to 70% benzocaine followed by intraperitoneal 50% pentothal. A routine necropsy was performed and representative tissues were submitted for histopathology. Tissues were fixed in 10% buffered formalin, embedded in paraffin, processed routinely, and stained by hematoxylin and eosin, Gram, and Kinyoun's acid-fast methods.

Pathologic Findings in Larval and Juvenile Anurans Inhabiting Farm Ponds in Tennessee, Usa

“…For example, A. hydrophila, Chryseobacterium indologenes, Citrobacter braakii, Edwardsiella tarda, Flavobacterium spp., and Pseudomonas spp. have been implicated as significant bacterial pathogens (Mauel et al, 2002;Forbes et al, 2004;Green and Converse, 2005) and trichomonad flagellates and strongyloid and oxyurid nematodes may be significant intestinal parasites. Although these organisms were documented in this survey, only A. hydrophila was associated with pathologic changes that appeared to impact the organism significantly (e.g., edema and erythema noted grossly).…”

“…Ranavirus, herpesvirus, adenovirus, and West Nile virus have been reported in amphibians, although West Nile virus has not been associated with disease (Green and Converse, 2005). Numerous bacteria may be cultured from anurans (Mauel et al, 2002), but Aeromonas hydrophila and Mycobacterium liflandii (e.g., a mycolac-tone-producing mycobacteria) tend to be recognized most often because the former can be associated with red-leg disease (Green and Converse, 2005) and the latter is closely related to the human pathogen Mycobacterium ulcerans (Yip et al, 2007). Many species of helminths have been documented in anurans, and often they are considered incidental (Miller et al, 2004), but their presence may be an indicator of stress related to land use .…”

Gut microbiota isolated from the European pond turtle (Emys orbicularis) and its antimicrobial resistance

“…More recently, a number of Chryseobacterium spp. were recovered from fish -some of these were diseased (Loch and Faisal 2012) (Mauel et al 2002), and humans (Calderón et al 2011, McKew 2014.…”

Isolamento de Aeromonas hydrophila em girinos de rã-touro na metamorfose

“…Vadivelu et al (1995) também isolaram o microrganismo do fígado, músculo, coração e baço de rãs e da pele de girinos. Huys et al (2003) observaram A. hydrophila ranae como causadora de septicemia em R. rugulosa, e Mauel et al (2002) observaram hiperemia cutânea e subcutânea e edema em R. catesbeiana, assim como observado neste trabalho. Glorioso et al (1974) relataram mortalidade de 70% durante a metamorfose de girinos de R. catesbeiana, acompanhada por hemorragia na cauda, sangue subcutâneo e úlceras no tecido cutâneo abdominal.…”