IMMUNOLOGICAL AND BACTERIOLOGICAL STUDIES ON

ORNITHOBACTERIUM RHINOTRACHEALIS

PRESENTED BY

RABAB AMIN KHALIFA

UNDER THE SUPERVISION OF

Prof. Dr. Mohamed Refai

Prof. of Microbiology, Faculty of Vet. Med. Cairo Univ.

and

Prof. Dr. Abd El-Gelil El-Gohary

Prof. of poultry diseases. Faculty of Vet. Med. Kafr El-Sheikh University

BEFORE 1994

the bacterium was named

Pasteurella-like,

Kingella-like or

Pleomorphic Gram-Negative Rod (PGNR)

and also the name TAXON 28 was used.

1994

It was named Ornithobacterium rhinotracheale

ORNITHOBACTERIUM RHINOTRACHEALE

VANDAMME ET AL., 1994

Biota

Domain Bacteria (Haeckel, 1894)

Phylum Bacteroidetes

Class "Flavobacteria"

Order "Flavobacteriales"

Family Flavobacteriaceae Reichenbach et al., 1992

Genus Ornithobacterium

ORT isolation from clinically infected flocks

% No. of +

flocks

Range of

mortality

Mean

age

(days)

No of

tested

chickens

No. of

examined

flocks

57.5% 23 0.2%-

16.8% 1 - 42

720 40

INCIDENCE OF ORT ISOLATION FROM

ORGANS

Organs No of

organs

No of

isolates

% isolation

Air sac 240 152 63%

Lung 160 95 59%

Joint 60 28 46.6%

Trachea 95 38 40%

Sinus 24 9 37.5%

Brain 40 12 30%

Yolk sac 150 40 26.6%

Reference

strains*

ORT positive

isolates Types of media

+ + -Sheep blood agar

+ + -Bovine blood agar

- - -MacCkonkey

+ + -Brain heart infusion agar

- - -PPLO broth

+ + -Tryptic soy agar

Different media used for Isolation of ORT

PINPOINT COLONIES OF ORT ON TRYPTIC SOY

AGAR

Biochemical identification

Reference

strains (18)

ORT isolates

(n=23) Reactions

Gram negative Gram negative (23) Gram stain

Negative (17) Negative (23) Catalase

Positive (17) Positive (23) Oxidase

Negative (18) Negative (23) Indole

Positive (18) Positive (13) Urease

Positive (17) Positive (17) Voges - Proskauer

Negative (18) Negative (23) Methyl red

Not tested Negative (23) Citrate utilization

Negative (18) Negative (23) Ornithine

decarboxylase

Positive (15)

Positive (17)

Positive (18)

(variable)

(variable)

Not tested

Positive (18)

(variable)

Positive (19)

(variable)

(variable)

(variable)

Oxidative/ferment

ation of

-glucose

-fructose

-lactose

-maltose

-galactose

-mannose

Non motile Non motile Motility test

The results of 18 reference strains puplished by Hinz, (1994).

BIOCHEMICAL CHARACTERISTICS OF ORT ISOLATED FROM

BROILER CHICKENS

ENZYMATIC REACTIONS OF ORT ISOLATES IN API 20 E

STRIP (24 HR.)

enzymatic activities of ORT isolates by Api ZYM

Reference ORT isolates Reactions

Positive Positive N-Acetyl-β-glucosaminidase

Positive Positive Phosphohydrolase

Positive Positive Acid phosphatase

Positive Positive Chymotrypsine

Positive Positive Alkaline phosphatase

Positive Positive Esterase

Positive Positive Esterase lipase

Positive Positive Leucine aminopeptidase

Positive Positive Valine aminipeptidase

Positive Positive Cystine aminopeptidase

Reference ORT isolates Reactions

Positive Positive Trypsine

Positive Positive -galactosidase

Positive Positive -glucosidase

Negative Negative -glucosidase

Negative Negative -glucoronidase

Negative Negative -fucosidase

Negative Negative -mannosidase

Negative Negative Lipase

PATHOGENICITY OF SOME ORT ISOLATES TO 11-

DAY CHICKEN EMBRYOS.

The inoculation of ORT into 11- day -old

embryos in SPF eggs

caused death of 10 out of 30 embryos (33.3%).

Application of ELISA kits in the diagnosis of

Ornithobacterium rhinotracheale (ORT)

infection in chickens

SAMPLES

511 serum samples from 24 clinically infected

broiler flocks at ages of 1-42 day

408 serum samples from 11 broiler-breeding

flocks at ages between 26-56 week, associated

with drop in egg production (1-4.5%).

ELISA KITS:

The ELISA Kits are available commercially and

supplied by

IDEXX-France

BioChek-Holand

Calculation and interpretation of the results

using ELISA software (provided by kits

suppliers)

ORT

isolation

Disease

problem

Results No of

tested

samples

Flock Suspect Positive

% No % No

+* Respirat. 0 0 2.5 1 40 F1

+* Growth

retardat. 0 0 10.0 4 40 F2

+* Respirat. 33.3 15 20 9 45 F3

+* Arthritis

Respirat. 31.6 12 23.7 9 38 F4

- Respirat. 2.4 6 0 0 56 F5

- Growth

retardat. 0 0 0 0 20 F6

Results of antibody detection of ORT by ELISA test

in serum samples from broilers using BioChek kits

ORT

isolat

ion

Disease

problem

Results No of

samp

les

Flock Suspect Positive

% No % No

+* Nervous 5 2 85 34 40 F7

+ Arthritis

Respirat. 57.1 8 28.5 4 14 F8

+ Respirat. 18.7 3 81.2 13 16 F9

- Respirat. 8.3 1 0 0 12 F10

- Healthy 0 0 0 0 30 F11

- Healthy 41.5 5 0 0 12 F12

13.5 49 20.3 74 363 Total

Results of antibody detection of ORT by ELISA test

in serum samples from broilers using BioChek kits

ORT

Isolatio

n

results

Disease problem

ELISA

(positive) No of

tested

samples

Flock

% No

+ Respiratory. 100 20 20 F13

+ Growth retardation 100 10 10 F14

+ Respiratory 100 10 10 F15

+ Growth retardation. 100 20 20 F16

+ Growth retardation. 5.0 1 20 F17

+ Respirat., growth

retardation. 41.6 10 24 F18

Results of antibody detection of ORT by ELISA test

in serum samples from broilers using IDEXX kits

ORT

Isolation

results

Disease problem

ELISA

(positive) No of

tested

samples

Flock

% No

+ Respiratory 100 12 12 F19

+ Respiratory 100 10 10 F20

+ Respiratory 100 12 12 F21

+ Respirat. ,growth

retardation 0 0 10 F22

- Respiratory 100 10 10 F23

- Healthy 0 0 10 F24

77.7 115 148 Total

77.7 115 148 Total

Results of antibody detection of ORT by ELISA test

in serum samples from broilers using IDEXX kits

Detection of antibody titers by ELISA test in serum

samples of broiler breeders using BioChek kit.

ELISA results No. of

tested

sample

s

Age

weeks Flock* Mean

titer Suspect Positive

% No % No

6215 30 3 70 7 10 32 F1

4565 30 3 70 7 10 33 F2

2581 30 6 70 14 20 49 F3

7751 10 2 90 18 20 54 F4

7166 10 1 90 9 10 57 F5

----- 21.4 15 78.5 55 70 TOTAL

Detection of antibody titers by ELISA in serum

samples of broiler-breeders using IDEXX kit.

ELISA results No. of

tested

samples

Age

(weeks) Flock*

Mean titre Positive

% No

4619 95.0 38 40 26 F6

1880 76.2 65 90 31 F7

3653 75.6 28 37 37 F8

4495 75.5 37 49 50 F9

6526 95.1 59 62 56 F10

3896 98.3 59 60 57 F11

---- 84.6 286 338 TOTAL