-Reptiles/amphibians (especially snakes) are believed to be reservoir hosts (Meyer and Bullock 1972)-Has also been sporadically isolated from different species of mammals and birds in Zaire in this study, the bacteria was also isolated from the water (Van Damme and Vandepitte 1980)Image sources:http://serc.carleton.edu/images/eslabs/fisheries/channel_catfish.jpg)Retention of Virulence in a Viable but NonculturableEdwardsiellatardaIsolateMeng Du,1Jixiang Chen,1*Xiaohua Zhang,1Aijuan Li,1Yun Li,1, and Yingeng Wang2
White F., Simpson C. Isolation of Edwarsiellatardafrom Aquatic Animal Species and Surface Waters in Florida. Journal of Wildlife Diseases Vol. 9, July, 1972.
Rob Bovino, Heather Byrnes, Nin Cameron-Blake, Omega Cantrell, Valerie Carril, Katie Cerulli
Watoday.com.au Bob - Dairy Farmer Exhibiting flu-like symptoms, chills and fever Previous incidence of Q fever was reported in nearby areas Bob was treated with doxycycline (200mg 1st day; maintenance = 100mg /day, ranging from weeks to months) No improvement seen after treatment Post-treatment blood antibody test confirmed it was not Q fever Cattle were tested for other possible zoonotic diseases
Caused by the bacteria Coxiella burnetii Affects sheep, goats, cattle, dogs and many other animals Shed in feces, urine, milk and birth products Zoonotic spread via inhalation of contaminated droplets People with highest risk of infection include farmers, lab workers, and veterinarians
VP N PD H2S I OD LD M U E ONPG ARAB ADON INOS SORB4 2 1 4 2 1 4 2 1 4 3 2 4 2 1- + - + + + + - - - - - - - - 2 7 4 0 0Code = 27400 = Edwardsiella tarda
Gram negative, motile bacillus Facultative aerobic, intracellular Intestinal commensal of a wide range of reptiles and amphibians ◦ Snakes, crocodiles, toads, frogs, tortoises, lizards Primarily a pathogen of fish ◦ Channel island catfish ◦ Commensal in some tropical species of freshwater fish
E. tarda has been isolated from several species of aquatic birds ◦ Brown pelicans, great blue herons, ring-billed gulls Wide variety of fish taxa, worldwide distribution in fresh and marine waters ◦ Channel catfish, striped bass, eel, tilapia, flounder, and salmonids
Type III and VI secretion systems ◦ Flagellar T3SS export flagellum components ◦ Non-flagellar T3SS translocates proteins across bacterial envelope and host plasma membrane Produces hemolysins and catalases in host cells
Abscesses rapidly Ingestion of Abscesses develop increase in size, bacteria likely Small cutaneous within muscles of develop into large Fish lose controlfrom contaminated lesions in postero- the flanks or cavities filled with over posterior half feces of humans, lateral areas of the caudal peduncle as gas; loss of of their body other animals, or body the disease pigmentation over reservoir host progresses lesion is common
Outbreaks are most common when water temperature >30ᵒC and there are high levels of organic fertilizer in the water Necrotized tissue remnants may fill up to ⅓ of the body cavity A foul odor is noticed upon incision of the lesions Emphysematous putrefactive disease of catfish (EPDC)
First identified as an etiologic agent in channel catfish in July 1969 Outbreaks have since been observed annually on fish farms in Arkansas, Mississippi, Louisiana, and Texas. Incident rate spikes when stock are moved from grow out ponds (5%) to holding tanks (50%), spreading rapidly through the population.
Terramycin (oxytetracycline) in the diet to control infection Minimally affected fish can heal within 10 days Several months may be required for severe lesions to heal To minimize impact, the disease should be detected prior to harvest
Infected fish that enter the processing line can be problematic Release of gas and liquid elements from lesions will result in contamination Processing line must be shut down, sterilized Financial losses can be significant even when small percentages of stock are involved The U.S. Fish and Wildlife Service has identified Edwardsiella tarda as a Pathogen of Regional Importance (PRI)
Has been isolated from fecal samples in human diarrhea cases Wide range of hosts, but fish are considered the most likely source of infection (via ingestion) Damme et al. isolated E. tarda from 57% of Zairese freshwater fish. ◦ Considered E. tarda along with P. shigelloides a source of sporadic diarrhea in tropical regions
Likely from ingestion of contaminated feed or water ◦ Fish meal Few reports of isolation of E. tarda from domestic animals ◦ Cattle, pigs ◦ Not known to cause disease in cattle
Bob was diagnosed with Edwardsiella tarda Since E. tarda are resistant to doxycycline, the doctor’s previous treatment was ineffective at eliminating the bacteria Treated with amoxicillin for 14 days Symptoms subsided
Meyer, F.P. and G.L. Bullock. (1973). Edwardsiella tarda, a new pathogen of channel catfish (Ictalurus punctatus). Applied Microbiology. 25 (1), 155-156. "Q Fever - PubMed Health." PubMed Health. NCBI, 23 Sept. 2010. Web. 18 July 2011. <http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002313/>. Van Damme, L.R. and J. Vandepitte. (1980). Frequent isolation of Edwardsiella tarda and Plesiomonas shigelloides from healthy Zairese freshwater fish: a possible cause of sporadic diarrhea in the tropics. Applied and Environmental Microbiology. 39 (1), 475-479. Wang, B. et al. (2009). Investigation of EscA as a chaperone for the Edwardsiella tarda type III secretion system putative translocon component EseC. Microbiology. 155 (1), 1260-1271. White F., Simpson C. Isolation of Edwarsiella tarda from Aquatic Animal Species and Surface Waters in Florida. Journal of Wildlife Diseases Vol. 9, July, 1972.