JPS62275680A - Infections bronchitis virus strain of poultry - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vaccine for infectious bronchitis (abbreviated as IB) in poultry and a method for producing said vaccine, and more particularly to a vaccine known in the art for vaccination. Among these viruses, it is associated with an improved infectious bronchitis vaccine derived from at least one strain of infectious bronchitis virus of a new serotype.

The application of live infectious bronchitis vaccines to poultry has been known for many years. Infectious bronchitis is a serious disease of the respiratory system, kidneys, and fallopian tubes in poultry. The cause of this syndrome is the coronavirus
). Poultry is severely affected by this livestock epidemic.

Infectious bronchitis continues to cause high mortality, especially among young poultry. In addition to mortality, more or less severe symptoms to the trachea and damage to the ovipositor can occur, resulting in a decrease in egg production due to IB disease. Furthermore, IB virus infection promotes latent viral or bacterial infections, thus providing economic benefits, particularly in the broiler industry.

Vaccines derived from inactivated viruses as well as from live viruses are applied in the fight against infectious bronchitis. However, it was found that after inactivation treatment of the viruses, for example by formalin and ultraviolet light, a loss of immunogenic properties occurs. CM, S., Hofstad.
Diseases or Poultry, Bies
Terand Schwarte, lowa
5tate University Press
To Yames (1965), 615)
.

Healthy birds can also be vaccinated with primary immunization (Pri) using a live, unattenuated or less attenuated virus vaccine.
As this poses a particular danger to animals 2-3 weeks old or to hens just before or during egg-laying, those skilled in the art are advised not to use killed vaccines or Live vaccines have been selected and used in an attempt to increase the harmlessness of the vaccines. The vaccine is based on an attenuated version of the original infectious bronchitis virus isolate.

For example, the H strain is currently in widespread use on a worldwide scale due to its broad immune spectrum, especially against Massachusetts and Connecticut IB-viruses;
ekstra and R15 pens) and attenuated [Tijdschr, Diergeneesk,
31: 43゜Infectious bronze
chitis in chicks in theNe
thelands” (1956), Tij
dschr, Dierg-eneesk, 85
: 320 (1960), Tijdschr.

Diergeneesk, 85: 279 (19
60) and TiJdschr, Diergen
eesk, 85:398 (1960).

To obtain these improved vaccines, viruses of the Massachusetts type, more specifically rBVW48, M41.82828, which have undergone 25 or more embryonic passages to reduce their virulence and transmissibility, are used. In addition to these 852 and 8120 strains, we are currently using them.

Both strains R52 and R120 were obtained by passing approximately 52 and 120 passages, respectively, on embryonic chicken eggs, and were obtained from connectica noto isolates such as A3968 or Bea
udette) IBV type (IBM-42).

The immunizing potential of these viruses is highly specific for the Massachusetts or Connectica types of IB viruses.

Although the use of these modified strain vaccines currently appears to be safe and effective, these vaccines are limited in the literature (Avian diseases vol.
, 2 0 , Nll 1 , p, 4 2 a
nd 177 and Avian Diseases
es vol, 1.9, 隘2, p, 323and
583), it is still not possible to completely satisfactorily prevent the occurrence of infectious bronchitis under certain conditions.

The shortcomings of current IB vaccines are attributable to the significant degree of antigenic variation of the virus (e.g. Archivfuer
die Gesamte Virusforschu
ng 34, p. 32 (1971) and Cu
nnningham C, 11, Develop.

Biol, 5 standard, 33.311
(1976)].

Efforts have therefore been made to achieve satisfactory vaccination of poultry by producing and applying a combination of vaccines derived from several IBM strains of various serotypes. However, clear difficulties have arisen leading to a reduction in the immunogenic properties of the respective starting viruses, which are derived from interactions (Am, J.
Vet, Res.

36.4.524 and 525 (1965)a
ndAvian Diseases 12.577
(1968)).

Therefore, there remains a great need for IB vaccines with sufficient immunogenic properties.

After multiple iIM passes in embryonic chicken eggs, the current I
It will be appreciated that changes in the immunogenic and other properties of the B virus still significantly impede continued improvement of the vaccine. The emergence of new serotype vaccines is desired, and it has been pointed out that there is a lack of serological immunological test methods that can be used sufficiently effectively (Avi
An Disease.

19.2.323 and 324 (1975)].

It was amazing that as a result of extensive research and numerous experiments, many new IB viruses were obtained.

These IB viruses are described, for example, in the literature (American
＾5sociation o(Avian Patho
logists, ” l5olation and I
identification of Avian Pa
thogens”, Page 184 (197
5)) Cross neutralization test (cross n
As confirmed in virus neutralization tests (viral neutralization tests), the current amount is also frequently used for H type (e.g. IB H1, 20 and IBH).
32) can be seen to be biased from the IB viruses. In other words, this bias was observed in challenge tests using antiserum diluted at a ratio of 1:5 and in the subsequent (virus reisolation test).In other words, when inoculated with type H virus, the recipient animals After attack by the novel deflected TB virus described above, there is a lack of protection against virus replication in the mucous membranes of the respiratory system.

Humoral antibodies against IBH strains also fail to neutralize significant amounts of IB virus of the polarized form described above.

What is particularly important in actual operations is that the new IB virus causes respiratory symptoms in animals that exhibit high antibody titers against the IBH strain, and also causes these symptoms in laying poultry, resulting in a decrease in egg production. That's true.

These new virus types are defined by the Dutch National Symbols Act, i.e. Utrecht, 10
1, (U, 101), Utrecht, 102
(U, 102), Drente.

201 (0,201), Limburg, 501 (
L, 501), Limburg.

502 (L, 502), Brabant, 801
(B, 801), Limburg.

536 (L, 536), Overijssel. 7
28 (0,728) and Utrecht, 121 (
U, 121) and Czechos 1ovakNa
tional Co11ection of Type
Cultures of the In5titut
e of llygiene and epidem
Deposit number CNC to iologyin Prague
TCAO7/80, CNCTCAO8/80, CNCT
CA09/80, CNCTC^010/80, CNCT
CA011/80, (Deposit date March 6.19
80), CNCTCAO16/80, CNCTCAO1
4/80, CNCTC6015/80 and CNCTCA
O13/80 (Deposit date September 9°19
80) and Co11ection Na
tionalede cultures de mic
roorganismes d'1stitutP
Asteur, Paris deposit number l-111
, l-112, l-113, l-109, r-110 (
Deposit date Nove+y+ber 14°1979> and f
-132, l-134, l-135 and l-133 (deposit date October 3, 1980).

All nine new serotype virus strains used in the present invention are of the same poultry infectious bronchitis virus (Avian
Infectious Bronchitis (rB)
Virus type of virus''J' (virus 5pec
ies). This virus species has spikes on its surface.
ronavirus) and single thread RNA type A (Sin
gle 5 tranded RNA type). However, all of the above nine new serotype viruses are the known serotype IB strains [Connecticut (Conr+
ecticut) strain, Massachusetts (!, Iassa
chussets strain, and H strain], and these nine strains also have mutually different properties.

The above viruses are trachea
It was isolated from a flock of egg-laying chickens using the tracheal cotton swab method (swab method). That is, the flock was vaccinated twice and thrice with the IB H120 and IBH32 vaccines, respectively, to achieve high humoral antibody titers against Massachusetts type IB virus at the onset of respiratory symptoms and/or decline in production. This was a flock that showed this. In addition, the above-mentioned viruses were isolated from young chickens, ie, young chickens that had been previously inoculated with H120 type IB vaccine and showed respiratory symptoms in the latter half of fattening. Viruses thus isolated for both species of animals were given symbols within the range indicated by the national symbology mentioned above.

that the virus strain isolated based on attenuation with 5PF-chicken embryos had a high degree of loss of pathogenicity against SPF chickens;
It has now been found that it nevertheless still retains its immunizing potential.

For example, the national symbol I B V Utrecht, 10
The virus strain with T F3 V Lim showed the above characteristics even after 85 passages of SPF type I chicken embryo.
burg.

The 536 virus strain showed this property even after 56 SPF type I chicken embryo passages.

Surprisingly, in comparative studies using the commonly used H120 or H52 vaccines, the protective ability (measured as the amount of virus that neutralizes antibodies) against the Massachusetts IB virus was significantly lower when the H-type vaccine was replaced with e.g. I in combination with the novel IBV isolation Utrecht 101
(It was found that administration of a type of vaccine did not reduce it to a significant degree.

In one experiment, the experiment was initiated by intranasal administration of the vaccine.

For example, the neutralization index (Table 1) was obtained 4 weeks after administration of each vaccine and vaccine combination.

Not only the immune response but also the resistance to viral replication and persistence in and on the tracheal mucosa after administration of each of the above-mentioned vaccines and vaccine combinations was measured. This measurement is performed using the virus reisolation method.
tions for the production
and control of avian 1ive
virus vaccines of theMini
Try of Agriculture, F
isheries and food of th
e United Kingdom Center
al Veterinary Shi aboraLory
of Biological Products
and 5eand-ards Department
ent, New Haw, Weybridge,
7153 NB on 5urrey, 2nd Editi
on (1977), p. 12.

A cross-neutralization test using SPF chicken embryos and a cross-infection test using SPF chickens were conducted, and the results shown in Tables 2 and 3 were obtained: Four types of literature can be cited as references regarding the above cross-neutralization test and cross-infection test: (a ) K, Kume et al., Am, J.
, Vet, Res, 41. (1)97-99
(1980).

(bl L, G, Raggi et al.
AVIAN DrSEASES 19. (21323-
333 (1975).

(cl R, N1elsen, Nord, Vet, M
ed, 3L 40 7-4.13 (1979).

(d) V. van Buelow, Cen.
tr, Blatt Vet, Med, pp
.

151-162 (1967).

In the above table, the symbol neg is the neutralization index (N,!,)
This means that it was not positive, that is, N, I, was 102.0.

In the above table, the symbol neg means that the SPF chicken eggs injected with the Trachiaswab method samples showed no signs of II3 virus infection.

From the results of Tables 2 and 3 (neutralization and cross-challenge test), there are four serotype IB viruses: H, U, 101, and 0.7.
Viruses types 28 and 536 are not only antigenically different from each other, but also have attractive immunogenicity (when considering the results of challenge experiments involving virus isolation) relative to their cognate viruses. It shows the various properties of

Utre was present in the serum of young hens, breeding hens, and laying hens in field experiments.
cht, 101, imburg, 536 and Ov
erijssel. It has been shown that antibodies against type 728 virus are frequently produced.

Therefore, the new IB virus type not only differs antigenically to a significant degree from the commonly used H virus type, but also exhibits various properties that are significantly different from each other.

This newly isolated virus strain could be characterized by the following tests: Mayr method (Mayr, A. et al., Viro
logische eight rbcitsmeth dcn
G, Fischer Verlag, Jen
a.

1977, ρ, 285).
Infected amniotic allantoic fluid obtained by culturing homogenized infected organs in the ic hole and original virus-containing samples obtained from Thracian swab collections.
nallantoic fluid), the replicate viral content was 10% compared to untreated samples.
It decreased from 7.5E[Dso to 101.'EIDS.

The results of this experiment showed that the libido necessary for contagiousness was reduced to an envelope (
virus agent (v) contained in the envelope).
irus agent).

Infectious amniotic allantoic fluid does not agglutinate red blood cells collected from SPF chickens.

Although the addition of 5-fluorodesoxyuridine (FIJDR) to the culture medium for young chicken kidney cell culture aids in the replication of viral agents, it does not significantly affect the intracellular synthesis of viral agents.

The EIDso content of the cytoplasm and culture medium reached comparable levels on days 2, 4 and 7 after viral agent inoculation. That is, the nucleic acids to be replicated belonged to the group of ribonucleic acids.

Electron microscopy results showed that the viral agent present in amniotic allantoic fluid collected within 30 hours after artificial infection had a diameter of approximately 1100 nm.

Approximately 15 nrrl long projections were present on the surface of this virus. This virus has the size and shape of a coronavirus, and the avian bronchitis virus is also considered to belong to this category.

The properties of the new serotype IB viruses described above have the potential to cause infectious bronchitis in regions or countries where not only the so-called H type IB viruses exist, but also particularly where the biased serotype viruses according to the present invention also exist. It is particularly suited for the production of inactivated as well as live poultry vaccines for effective protection.

Furthermore, the serotype virus strains of the new virus strains mentioned above are a live vaccine that is a mixture of those derived from the new IB strain, the H strain, and one or more of the new IB strains. and can be successfully applied in the production of inactivated vaccine products.

The novel IBV vaccines of the invention are obtained by propagation methods, in principle according to methods known in the art, and then optionally by inactivation methods, in principle according to methods known in the art.

The virus may be propagated, for example, in embryonic SPF chicken eggs or in suitable cell cultures, such as chick kidney cell cultures. However, when using such methods, it must be checked whether the antigenicity changes significantly.

Afterwards, the cultured virus material
material) are collected and purified. Finally, one or more stabilizers and optionally antibiotics such as penicillin G1 streptomycin or natamycin are added and the mixture is stored frozen or lyophilized.

More specifically, the virus of the seed strain to be used was grown under sterile conditions with S.
Pre-lysis of PF type ■ (10-11 days) Chicken egg allantoic membrane (
inoculate into the allantoic cavity).

After incubation at 37° C. for 28-34 hours, the amniotic allantoic fluid of still-viable and specifically dead embryos (i.e., after 24 hours of inoculation with the seed strain virus) was removed and purified. Optionally, stabilizers and/or antibiotics are added prior to frozen storage.

According to this method, after frozen storage, Σ104 per dose
- Single vaccines containing virus in an amount of E I Dso can be prepared.

On the other hand, there are new virus strains, known H strains, or combined vaccines of multiple new virus strains.
vaccines) and Σ2X per dose.
l O'-' E IDS. of virus content and preferably Σ104·0 EID per dose. The combined vaccines were produced with respective virus contents of .

It will be appreciated that the present invention relates to novel inactivated as well as live IBV vaccines derived from at least one strain of the novel IB virus strain.

Preferably, the live vaccine used is one derived from novel viruses or from a combination of one or more novel [B viruses and Fr-type viruses].

Most preferably live vaccines derived from H120 or H52 virus strains and U, 101, L.

A live vaccine derived from one or more IB viruses selected from the group consisting of 536 and 0.728 is used. The vaccines are applied using young animals and more preferably young chickens.

The vaccines are so-called eye-drops.
p) or by nosedrop; for live vaccines, by potable water or by spraying.

Vaccination with the new live vaccine according to the present invention is carried out after cape formation.
It is preferably carried out using poultry from 18 days to 18 weeks. The novel inactivated vaccine according to the invention is injected subcutaneously or intramuscularly into animals.

New [at least one strain of B virus and completely other types of viruses, such as Newcast virus
It will be appreciated that combined live or inactivated vaccines derived from combinations with a strain or strains of le disease virus, adenovirus or reo virus are also possible.

In producing the inactivated IBV vaccine according to the present invention, for example, amniotic allantoic fluid is used, a suitable carrier is added thereto, and the vaccine is inactivated by methods known in the art, such as using beta-propiolactone or formalin.

A virus solution of appropriate titer is processed to form a water-in-oil emulsion vaccine. Emulsions are made of mineral or vegetable oils and one or more emulsifiers such as alkylene oxides and (
or) hexahydric alcohol and (or) higher natural sources (CIo
~C2°) emulsifiers such as nonionic transactive compounds derived from esters or ester-ethers of fatty acids.

■ 80 (for example, Tween 80).

The volume ratio of the aqueous phase (viral fluid) and oil phase is 3 near to 1:
The ratio may vary from 1 to 1, but is preferably about 7:13.

The present invention will be illustrated by the following examples, but the scope of the present invention is not limited to these specific embodiments.

Example 1 Virus Isolation and Dissection The tracheas of a C11 flock (3 to 10 birds) were colonized using cotton balls. 3-5 m7 containing 1000 units of penicillin G and 1 mg of streptomycin per l mal!
The above carrier material was transferred to a tryptose phosphate-containing medium (broth). Homogenize the broth containing this carrier material to obtain 0.2 mj of this homogenized fluid! Embryonic development 9-1
Ten allantoic membranes of chicken eggs after 0 days.
ic caviLies). All capital offenses were excluded 24 hours after this first inoculation (
This is thought to be due to special mortality mainly based on first-stage material that is not sterilized by herbicidal methods. 1st
Only eggs that survived 24 hours after the second treatment and survived up to 6 days after inoculation were used for the second egg passage. I21] After 9-10 days of embryonic development, into each of the 10 allantois of a group of rabbits, 0.0% of the allantoic fluid reserve of the rabbits of the first group (first 10) was added.
2 ml was inoculated. Six days after this second solid inoculation, egg allantoic fluid was collected, stored, and serologically tested to determine the known (
It was confirmed that this virus contains virus material that is serologically different from B viruses. This fact is based on the history of the flock and the appearance of dead and viable embryos (curling, scunting) 6 days after the second solid inoculation.
tun ting), medium height (mesonephros)
) and by the previously described virological properties (see Tests for Characterization of Newly Determined Virus Strains).

After passing through eggs twice and isolating the virus strain as described above, pass through eggs 50 times (in the case of vaccination for chickens that have been 4 weeks or more since lysis) and pass through eggs 100 times (4 weeks after lysis).
(for vaccination of young chickens up to 1 week old) to soften (attenuate) the virus strain to make it suitable for vaccination. This operation is similar to the operation for the second egg passage described above (
In this case, each group of 6 eggs was inoculated and inoculated 24 hours later (6 days later). (not) was collected and observed.

After 50 and 100 egg passages, respectively, the allantoic fluid was not pathogenic to the living organisms of chickens and young chickens, respectively, and could therefore be used for vaccine production.

The procedure of this example could be performed on all nine virus strains of the invention.

Example 2 (Reference example) Production of IB virus vaccine of Ll, 10'1 strain (A)
Virus culture: 10'-' to 10'-'E IDs for Type 2 SPF chicken eggs kept at constant temperature for 10 to 11 days.

IBV U, 101 seed virus (0 per chicken egg)
．． 2 ml) was inoculated intraallantois. Virus inoculation machine 20~
After 24 hours, the inoculated eggs were examined and all non-specific dead embryos were removed. Amniotic allantoic fluid (AAF) was collected after a total of 28 hours of incubation at +37°C.

(B) Treatment of Virus Suspension After purification by centrifugation at 200 rpm in a refrigerated centrifuge and/or filtration, 5 x 105 units of sodium penicillin G per 1β and 800 mg of streptomycin were added to the AAF.

This viral material was then stabilized with at least 3% by weight albumin and/or mannitol. The stabilized viral material was frozen to at least -35°C and stored at this temperature until further processing.

Regarding this sample of viral material E (Dso
C Egg Infection Dose5
0%)] virus content was tested using the test method. Once the virus was determined to be usable by this test, the viral material was again thawed and placed into freezing flasks.

The virus content present in the vaccine per dose at the end of frozen storage is at least 104.5 EID.

The virus content (volume) is adjusted to maintain .

After frozen storage, seal the flask under vacuum.

Example 3 (Reference example) Production of IB virus vaccine for L.536 strain.) Virus culture ■ Type SPF chicken eggs were kept at constant temperature for 10 to 11 days, and then 103-' to 104.0EED5. I
BV L, 536 seed virus (0.2 per egg)
m1) was inoculated (intra-allantoic).

The eggs were examined and all non-specifically dead embryos were removed from the virus incubation chamber after 20-24 hours. The AAF was removed after incubation at +37° C. for a total time of 32 hours.

(B) Treatment of the virus suspension After purification of the AAF by centrifugation at 2000 rpm in a refrigerated centrifuge and/or filtration, 6XIO5 units of sodium penicillin G per 1β and 900 mg of streptomycin were added to the AAF.

This viral material was then stabilized by the addition of approximately 5% albumin and/or mannitol. This stabilized virus material was then frozen to -35°C and maintained at this temperature until the next step of processing.

Regarding this sample of viral material, E r D5.
The virus content was tested using a testing method. After testing showed that the virus was usable, the viral material was thawed again and placed into a freezing flask.

The virus content (volume) was adjusted such that at least 104.5 EIDso were present in the vaccine per dose of virus during the later stages of the freezing process.

The flask was sealed under vacuum at the end of the freezing process.

Example 4 (Reference example) Production of 0.728 strain IB virus vaccine (A)
1 for type SPF chicken eggs that have been kept at constant temperature for 10 to 11 days.
0'-0~104・0EID,.

IBVo, 728 strain virus (0.2 mA per egg)
) was inoculated. The eggs were examined and all non-specifically dead embryos were removed from the virus incubation chamber after 20-24 hours. The AAF was removed after incubation at +37° C. for a total time of 32 hours.

(B) Treatment of Viral Suspension After purification of the AAF by centrifugation at 200 rpm in a refrigerated centrifuge and/or filtration, 8×10 5 units of sodium penicillin G per 1β and 1100 mg of streptomycin were added to the AAF.

This viral material was then stabilized by the addition of approximately 7% by weight albumin and/or mannitol. This stabilized virus material was then frozen to -35°C and maintained at this temperature until the next step of processing.

A sample of this virus material was tested for virus content using the EIDso test method.

After testing showed that the virus was usable, the viral material was thawed again and placed into a freezing flask.

The virus content (volume) was adjusted such that at least 104·'E I Dso was present in the vaccine per dose of the virus at the end of the freezing process. The flask was sealed under vacuum at the end of the freezing process.

Example 5 (Reference example) (A> Virus culture 1.
0" ~ 10" E ID5o IBVU, 101, L
, 536, and 0.728 strain viruses (total of 0.2+yl per egg) were inoculated intraallantois.

The eggs were inspected and all embryos that died non-specifically were removed from the virus temperature chamber after 20-24 hours. The AAF was removed after incubation at +37° C. for a total time of 32 hours.

(B) Treatment of virus suspension After purification of the AAF by centrifugation at 200 rpm in a refrigerated centrifuge and/or by filtration, 8 x 105 units of sodium penicillin G per 11 and 1000 mg of streptomycin were added to the AAF.

This viral material was then stabilized by the addition of at least about 3% by weight albumin and/or mannitol. Next, this stabilized virus material is
It was frozen at 0.degree. C. and maintained at this temperature until processing in the next step.

About this sample of viral material
The virus content was tested using a testing method.

After testing showed that the virus was usable, the viral material was thawed again and placed into a freezing flask.

The virus content (volume) was adjusted such that at least 104·'EIDso was present in the vaccine per dose of the virus at the end of the freezing process. The flask was sealed under vacuum at the end of the freezing process.

Example 6 (Reference example) Virus was cultured in SPF chicken eggs by the same operation as described in Example 5 (A), and the one-thickened virus suspension was treated in the same manner as Example 5 (B) and placed in the frozen phase. I achieved it. However, antibiotics and stabilizers were not added.

The frozen AAF was thawed and inactivated with 0.1% beta-propiolactone at 37° C. for 90 minutes in a water bath. This virus suspension was kept at +4°C overnight. The achievement of inactivation was checked by inoculating inactivated virus material into SPF chicken eggs that had been falsified and embryonic in advance and kept at constant temperature.

Dilute the inactivated AAF as needed using PBS + 0.3% formalin based on the winter virus E I Dsa value of the inactivated AAF (at least 107°0 for all virus strains). . 3.5% non-ionic surfactant (Tween 80) was added to the virus suspensions of the four strains.

The inactivated virus suspension and the oil phase were mixed and emulsified in a ratio of 6.5 parts of the oil phase/3.5 parts of the virus fluid, so that the average particle size of the aqueous phase was adjusted to about 0.5 μm. did.

A homogenizer (Ultra Turrax) is used to perform emulsification.
homogeniser) or passing the raw mixture through a colloid mill.

OO0 Arlacel A, Ar! acel 80
, or 5pan 80 (mannide monooleate)6.
The components of the 5% oil phase are heated individually to 110° C. in an autoclave or the mixture is sterile filtered.

Claims (2)

[Claims] (1) Dutch national symbol Utrecht. 101, Ut.
recht. 102, Drente. 201, Limb
urg. 501, Limburg. 502, Braba
nt. 801, Limburg. 536, Overij
ssel. 728 and Utrecht. 121, Czechoslovak National
Collection of TypeCulture
es of the Institute of Hy
giene and epidemiology in
Deposit number CNCTC A 07/80 in Prague
, CNCTC A 08/80, CNCTC A 09
/80, CNCTC A 010/80, CNCTC
A 011/80, CNCTC A 016/80, C
NCTC A 014/80, CNCTC A 015
/80 and CNCTC A 013/80, and C
Collection Nationale de Cu
Cultures of MiCroorganismes
d'Institut Pasteur, Paris
Deposit number I.S. 111, I. 112, I. 113, I
．． 109, I. 110, I. 132, I. 134, I.
135 and I. A novel poultry serotype infectious bronchitis virus strain, characterized in that it is selected from the group consisting of virus strains deposited as No. 133. (2) Dutch national symbol Utrecht. 101, Li
mburg. 536 and Overijssel. 728
Shown as Czechoslovak Nation
al Collection of Type Cul
tures of the institute of
Hygiene and Epidemiology
Deposit number CNCTC A 07 in Prague
/80, CNCTC A 014/80 and CNCTC
As A 015/80 and Collection
National de Cultures de
Micro-organismes d'Insti
Deposit number I. tut Pasteur, Paris. 1
11, I. 134 and I. A novel poultry serotype infectious bronchitis virus strain according to claim (1), characterized in that the strain is selected from the group consisting of virus strains deposited as No. 135.