Group presentation for identifying an unknown bacterium, done for bacteriology lab (VPA 5351) at RUSVM.

1. Rob Bovino, Heather Byrnes, Nin Cameron-Blake,
Omega Cantrell, Valerie Carril, Katie Cerulli

2. 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

3.  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

4.  Chest pain w/ breathing  GI symptoms
 Skin redness
 Clay-colored stools  Skin pain
 Cough  Skin swelling
 Fever  Skin tenderness
 Fever
 Headache  Headache
 Jaundice  Abdominal pain
 Nausea
 Muscle pains
 Diarrhea
 Rash (not common)  Liver abscess
 Shortness of breath  Sepsis
Query fever E. tarda

5. The following results were found
when the cattle were tested

6. Drug MIC S/R/I
Amoxicillin 1.0 µg/mL Susceptible
Gentamicin 0.75 µg/mL Susceptible
Erythromycin 16 µg/mL Resistant
Chloramphenicol 4 µg/mL Susceptible

7. Disk Name Diameter (mm) S/R/I
E Erythromycin 9 Resistant
S Sulfisoxazole 9 Resistant
AMC Amoxicillin- 23 Susceptible
clavulanic acid
D Doxycycline 13 Resistant
CPD Cefpodoxime 8 Resistant
ENX Enrofloxacin 17 Intermediate

8. Drug MIC Drug MIC
Aztreonam < 8 µg/mL Imipenem < 2 µg/mL
Cefazolin < 4 µg/mL Nitrofurantoin < 16 µg/mL
Cefepime < 4 µg/mL Cefoxitin < 4 µg/mL
Cefotetan < 8 µg/mL Piperacillin < 16 µg/mL
Ceftriaxone < 1 µg/mL Piperacillin/tazobactam < 16/4 µg/mL
constant
Ceftazidime < 1 µg/mL
Ticarcillin/clavulanic acid < 16/2 µg/mL
Cefuroxime < 4 µg/mL
constant
Ciprofloxacin < 0.5 µg/mL
Trimethoprim/ < 0.5/9.5 µg/mL
Gatifloxacin < 1 µg/mL sulfamethoxazole
Meropenem < 1 µg/mL Tobramycin < 4 µg/mL
Gentamicin < 2 µg/mL Cefpodoxime < 2 µg/mL

9. VP N PD H2S I OD LD M U E ONPG ARAB ADON INOS SORB
4 2 1 4 2 1 4 2 1 4 3 2 4 2 1
- + - + + + + - - - - - - - -
2 7 4 0 0
Code = 27400 = Edwardsiella tarda

10.  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

11.  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

12.  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

13. Abscesses rapidly
Ingestion of Abscesses develop
increase in size,
bacteria  likely Small cutaneous within muscles of
develop into large Fish lose control
from 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

14.  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)

15.  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.

16.  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

17.  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)

18.  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

19.  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

20.  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

21.  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.