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1.
Two isolates of Haemophilus paragallinarum were obtained from a layer chicken in Mexico. The isolates were confirmed as H. paragallinarum by polymerase chain reaction and conventional biochemical identification. The isolates were nicotinamide adenine dinucleotide (NAD) independent-growing on blood agar without the need of a nurse colony as well as on a complex medium that lacked both NAD and chicken serum. Both isolates were pathogenic, causing the typical clinical signs of infectious coryza in susceptible chickens. One isolate was Page serovar B/Kume serovar B-1 and the other isolate was Page serovar C/Kume serovar C-2. The isolates were associated with a field outbreak that involved an egg drop of 20% over a 3-wk period and a doubling of weekly mortality (from 0.1% to 0.2%). This is the first report of NAD-independent H. paragallinarum outside South Africa and is the first time that NAD-independent H. paragallinarum of serovar B has been reported.  相似文献   

2.
An indication of the ability of NAD-independent variants of Haemophilus paragallinarum to evade the immune system has been obtained from data obtained from several experiments. Firstly, it was noted that there was a difference in the serovar distribution between the NAD-dependent isolates in the 1990s and the NAD-independent isolates, as there was a significant decrease in the incidence of serogroup A NAD-dependent isolates. This can possibly be attributed to the extensive use of vaccines. On the other hand, most of the earlier NAD-independent isolates were serovar A. This is a possible indication of evasion of the protective immunity by the NAD-independent isolates. Further evidence of possible evasion of the protective immunity was obtained from results obtained when different isolates, both NAD dependent and NAD independent, were tested with a panel of monocional antibodies (Mabs). The V1 Mab reaction pattern was only seen in the reference strain 0083 among all of the NAD-dependent isolates tested in South Africa. This Mab was, however, found to react with some of the NAD-independent isolates. Furthermore, the isolation of NAD-dependent isolates in Australia which react with the V1 Mab also suggest possible evasion of the protective immunity by the NAD-independent isolates as no vaccines containing strain 0083 are used in Australia. In order to investigate the hypothesis of immune-evasion by NAD-independent H. paragallinarum, vaccinated and unvaccinated chickens were challenged with a NAD-independent serogroup C isolate. As a control, chickens were also challenged with NAD-dependent H. paragallinarum of the same serogroup. The results obtained indicate that there is no significnat difference in the disease profiles obtained in vaccinated and unvaccinated chickens challenged with the NAD-independent isolate, thus providing further evidence of evasion of the productivity immunity by the NAD-independent isolates. The ability of the NAD-independent isolates to evade the immune system suggests that a different vaccination strategy, or alternative control methods may be needed for the control of IC caused by these isolates.  相似文献   

3.
A NAD-dependent isolate 46 (C-3) of Haemophilus paragallinarum, which was previously demonstrated to be of high virulence, was transformed to NAD independence using a plasmid isolated from a naturally occurring NAD-independent isolate of H. paragallinarum. The transformation was performed by two different methods and the identity of all of the isolates, before and after transformation was confirmed using a H. paragallinarum-specific PCR test. The transformed NAD-independent serovar C-3 isolate and the wild-type serovar C-3 isolate were used to experimentally infect vaccinated layer chickens. It was shown that the transformation to NAD independence significantly altered the virulence of the serovar C-3 isolate that was used in the transformation experiment. The mechanisms responsible for a decrease in virulence are not clear, but may be related to the pathology of the transformed isolate in the sinus of the chickens.  相似文献   

4.
In South Africa the incidence of NAD-independent Haemnophilus paragallinarum isolation from clinical cases is increasing. This study was carried out to test whether a commercially available coryza vaccine (Nobilis Coryza, Intervet International BV) could protect chickens against challenge with recent NAD-independent isolates. SPF chickens were vaccinated twice at 3 and 7 weeks of age and were challenged at 9 weeks of age with 5 different NAD-independent isolates of serotype A or C-3. The results after challenge show that the coryza vaccine induces good protection against challenge with the different South African NAD-independent isolates of H. paragallinarum, including serotype C-3.  相似文献   

5.
Ten gram-negative, pleomorphic, rod-shaped isolates from coryza-like, respiratory diseased laying and broiler chickens were identified as Ornithobacterium rhinotracheale. All O. rhinotracheale isolates showed typical biochemical and enzymatic characteristics. Also, all isolates showed hemagglutinating activity with glutaraldehyde-fixed erythrocytes. On the basis of this property, a rabbit-raised antiserum was produced for an isolate. All isolates were identified by antiserum by hemagglutination-inhibition tests. No cross-reactions were observed when O. rhinotracheale isolates were tested with Haemophilus paragallinarum antisera, and vice versa. Mild respiratory signs, including mild nasal discharge, slight rales, and sneezing, were observed in challenged chickens. At postmortem examination, multifocal pneumonia, airsacculitis, and foamy exudate in abdominal cavity were observed. Furthermore, because bacterial adherence is regarded as an essential step in the infection process, in vitro adherence of O. rhinotracheale isolates to chicken tracheal epithelial cells was tested. All isolates showed positive adherence. Obtained results indicate that O. rhinotracheale is a pathogenic agent present in the Mexican poultry.  相似文献   

6.
Koga Y  Zavaleta AI 《Avian diseases》2005,49(1):108-111
Strains of the bacterium Ornithobacterium rhinotracheale (ORT), a causal agent of respiratory diseases in birds, were microbiologically isolated, identified, and molecularly characterized. Blood-enriched culture media and biochemistry tests were used for microbiologic identification. Polymerase chain reaction (PCR) and repetitive extragenic palindromic PCR (rep-PCR) techniques were used for molecular identification and characterization, respectively, of the microorganism. ORT strains were isolated in enriched media from the trachea and air sacs of broilers, breeders, and layers from several geographic zones of Peru. Of the original 75 strains isolated from 75 clinical samples from which ORT was recovered during 1998-2000, 25 were selected for further study based on ORT as the primary pathogenic isolate (no other pathogens were detected). Selected isolates were molecularly identified and characterized by PCR using specific primers designed from the conserved zones of the 16S ribosomal genes. Primers used for the identification of ORT produced a specific fragment of 784 base pair (bp), which did not appear in Haemophilus paragallinarum or Pasteurella multocida, microorganisms with similar morphologic and biochemical characteristics that produce dinical signs identical to those of ORT. All 25 strains of ORT tested with rep-PCR had a genetic profile similar to that of ORT American Type Culture Collection 51463, indicating the presence of only one genotype in the ORT strains studied.  相似文献   

7.
A L Hung  A Alvarado 《Avian diseases》2001,45(4):999-1005
Twenty-five isolates of Ornithobacterium rhinotracheale were examined by agar gel precipitation, immunoperoxidase assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, western blot analysis, and a polymerase chain reaction. All of the isolates were identified as serotype A. Protein profiles of whole cell extracts were similar for all the isolates, and a polypeptide with a molecular weight of 33 kD was a major component, being present in all the isolates. In the main, proteins of 33, 42, 52, and 66 kD were recognized in immunoblots with sera from chickens naturally exposed to O. rhinotracheale. A modified polymerase chain reaction assay identified O. rhinotracheale DNA from all the isolates and tracheal swabs, producing amplicons of 784 bp, and distinguished O. rhinotracheale from bacterial agents causing similar clinical signs.  相似文献   

8.
The resistance to anti-microbial agents of bacteria isolated from pathological conditions of birds in Victoria, 1978 to 1983, was determined for isolates of Escherichia coli, Salmonella species, Staphylococcus aureus, Pasteurella multocida, P. anatipestifer, Yersinia pseudotuberculosis and Haemophilus paragallinarum. The isolates of E. coli had a high prevalence of resistance to tetracycline and sulphonamides, and a lower prevalence of resistance to furazolidone and sulphamethoxazole-trimethoprim. The isolates of Salmonella spp commonly had resistance to tetracycline, sulphonamides, furazolidone and sulphamethoxazole-trimethoprim. Almost half the isolates of S. aureus showed resistance to lincomysin and many showed resistance to penicillin. Resistance to tetracycline was found in isolates of P. multocida, P. anatepestifer and Y. pseudotuberculosis. Some isolates of H. paragallinarum showed resistance to sulphonamides, streptomycin and sulphamethoxazole-trimethoprim.  相似文献   

9.
A total of 100 poultry farms in northern and middle areas of Jordan were sampled to investigate the bacteria associated with airsacculitis in broiler chickens. Of 170 bacterial isolates, 88.2% were identified as Escherichia coli, 8.8% as Ornithobacterium rhinotracheale, and 3% as Bordetella avium. Fourteen serotypes of E. coli were identified among 66 typeable isolates and the remainder were untypeable. The most prevalent serotypes were O1, O8, and O78. The main serotype of O. rhinotracheale was serotype A. Experimental inoculation of O. rhinotracheale via intravenous, intratracheal, and intra-air sac routes resulted in growth retardation, thickening in the air sacs, arthritis, and liver necrosis. Reisolation of O. rhinotracheale from the air sacs, liver, trachea, heart, and spleen at day 7 postinoculation confirmed its role. In vitro susceptibility testing revealed that E. coli isolates were sensitive to gentamicin and colistin, O. rhinotracheale to tetracyline, and B. avium to most of the nine antibiotics examined.  相似文献   

10.
Chromosomal DNA from Haemophilus paragallinarum was examined by restriction endonuclease analysis (REA) using the enzymes BamHI, EcoRI, HindIII, or SmaI. The enzyme SmaI had no apparent effect upon the DNA from eight representative H. paragallinarum isolates. The remaining enzymes cut the H. paragallinarum DNA to varying degrees, with the most useful patterns for distinguishing isolates being given by HindIII. The REA patterns given by HindIII were stable under both in vitro and in vivo conditions. The use of the enzyme HindIII showed that eight Australian isolates of H. paragallinarum were genetically similar. In contrast, 14 isolates of H. paragallinarum from outside Australia were markedly different from each other and the Australian isolates. A plasmid of approximately 6 kilobase pairs in size was found in one isolate of H. paragallinarum.  相似文献   

11.
An oil-based bacterin, containing strains 083 and 0222 of Haemophilus paragallinarum, is commonly used in South Africa to vaccinate laying flocks against infectious coryza. Two strains of H. paragallinarum, designated M85 and SB86, were isolated from infected but vaccinated commercial laying flocks in two incidental outbreaks of coryza in 1985 and 1986. A panel of five monoclonal antibodies was established which clearly distinguished the vaccine strains from the field isolates. One of these reacted with only vaccine strains A and B, another reacted with only field strains M85 and SB86, and the remaining three cross-reacted to various degrees with all four strains or isolates. Immunoassays were performed by enzyme-linked immunosorbent assay using whole bacteria as solid-phase antigen. These monoclonal antibodies may aid in serotyping new field isolates of H. paragallinarum and in improved standardization of vaccine strains.  相似文献   

12.
We report on the production and characterisation of monoclonal antibodies (MAbs) against Haemophilus paragallinarum, the causative agent of infectious coryza. A bank of 8 MAbs were produced by traditional techniques - four against the reference strain for Page serovar A (0083) and four against the reference strain for Page serovar C (Modesto). Seven of the eight MAbs were shown to be IgG(1) with one being nontypable. None of the MAbs had HI activity and none gave any detectable reaction when examined by Western blotting. None of the MAbs gave a positive reaction in the indirect ELISA with any of the eight type strains of Pasteurella species or sub-species. None of our 8 MAbs gave serovar specific reactions when used in an indirect ELISA format. There was a trend for the serovar A MAbs to give a higher titre with serovar A isolates/strains and a similar trend for the serovar C MAbs to give higher titres with the serovar C isolates/strains.  相似文献   

13.
Naturally occurring NAD-independent variants of Haemophilus paragallinarum, which have been isolates from poultry showing clinical signs of infectious coryza, were used to determine their virulence using a newly developed challenge model for infectious coryza. It was established that the NAD-independent isolates belonging to a particular serogroup, were less virulent when compared to the virulence of the NAD-dependent isolates from the same serogroup. It was shown that the virulence of the NAD-independent isolates belonging to serogroup C and serogroup A were very similar to each other. This differs to the results obtained with NAD-dependent isolates reported on previously, in which the serogroup C isolates were found to be more virulent then the serogroup A isolates.  相似文献   

14.
嗜肺巴氏杆菌的临床检测方法的评价   总被引：1，自引：0，他引：1  
巴氏杆菌具有20个种，嗜肺巴氏杆菌就是其中一个种。由于这个家族地位特殊，巴氏杆菌种目前归属于巴氏杆菌属、放线杆菌属和嗜血流感杆菌属。嗜肺巴氏杆菌具有广泛的宿主，存在于许多啮齿类动物，其它实验动物中，也存在于人中。属中各个种的生化特性比较相似，采用目前的国家标准实验动物微生物检测方法，不能有效区分与嗜肺巴氏杆菌生化特性相类似的其它种。我们通过抽检广东省清洁级以上实验小鼠和大鼠280只．分离到168株巴氏杆菌，通过扩大生化鉴定项目，154株被确认为嗜肺巴氏杆菌，14株被划分为放线杆菌-嗜血流感杆菌-巴氏杆菌复合体。所分离的嗜肺巴氏杆菌表现甘露醇阳性，这与文献报道不符合。因此，在现有的鉴定嗜肺巴氏杆菌的生化标准上，增加了鸟氨酸脱羧酶、甘露醇、ONPG等生化项目，将有利于嗜肺巴氏杆菌的临床检测。  相似文献   

15.
The commercially available API ZYM microbiological identification system was evaluated for the rapid identification of Haemophilus somnus. Eighty-seven isolates of the organism had API ZYM profiles which were characteristic. The API ZYM profiles demonstrate clear differences between H. somnus and other genera but suggest a close association to three related organisms. Enzyme activity of H. somnus isolates were similar to organisms identified as Histophilus ovis, Haemophilus agni and strains UQV of Actinobacillus actinoides and Actinobacillus seminis but was clearly different from isolates of Pasteurella haemolytica, Pasteurella multocida, Bordetella bronchiseptica and group EF4. The API ZYM system allowed more rapid identification of H. somnus than conventional biochemical tests and may be a useful adjunct to conventional methods used for identification of H. somnus isolates. The test did not reveal obvious differences between isolates from various anatomic locations.  相似文献   

16.
OBJECTIVE: To characterise 18 isolates of Haemophilus paragallinarum isolated from chickens in Indonesia. PROCEDURE: The isolates were identified to species level by traditional phenotypic methods. Six of the isolates were also identified by a species-specific polymerase chain reaction. Fourteen of the isolates were examined for resistance to a panel of seven antimicrobial agents using a disc diffusion method. All 18 isolates were serotyped according to the Page scheme using reference antisera in a haemagglutination inhibition test. RESULTS: Four of the 18 isolates were obtained from indigenous (kampung) chickens, with the remainder being from typical intensive poultry production systems. The 18 isolates were obtained from 11 outbreaks that showed the typical clinical signs of infectious coryza and 11 of the isolates were obtained from chickens that had been vaccinated with infectious coryza vaccines. All 18 isolates were confirmed as H paragallinarum by biochemical testing and six isolates were also identified as H paragallinarum by the polymerase chain reaction test. Eleven isolates were resistant to erythromycin and streptomycin, 10 to neomycin, eight to oxytetracycline, five isolates to doxycycline, three to sulphamethoxazoltrimethoprim but only one to ampicillin. Seven isolates were Page serovar A, four were Page serovar B and seven were Page serovar C. CONCLUSION: The presence of all three Page serovars (A, B and C) has been confirmed for the first time in Indonesian chickens. As the majority of the infectious coryza vaccines in use in Indonesia contain only serovar A and C, the presence of serovar B in chickens indicates that the protection by these bivalent vaccines would be reduced. The use of trivalent infectious coryza vaccines that contain serovars A, B and C is recommended for use in Indonesia.  相似文献   

17.
BITSCH, V., N. F. FRIIS and H. V. KROGH: A microbiological study of pneumonic calf lungs. Acta vet. scand. 1976, 17, 32–42.–Fifty pneumonic calf lungs were subjected to microbiologic screening with regard to bacteria, mycoplasmas, and viruses.Of bacteria the species most commonly found were Pasteurella multocida (eight lungs), Pasteurella hemolytica (eight lungs), and Corynebacterium pyogenes (13 lungs). Of special interest was the demonstration of Neisseria spp. in five lungs. Mycoplasma dispar was found in 31 lungs, Mycoplasma bovirhinis in 16 lungs, and Urea-plasma in 26 lungs. Cytopathogenic agents were demonstrated in 14 lungs. Four isolates were found to be bovine respiratory syncytial virus, three were bovine viral diarrhea virus, and two were bovine parainfluenza 3 virus. The remaining five cytopathogenic agents were not identified.  相似文献   

18.
猪多杀性巴氏杆菌的分离鉴定及生物学特性研究   总被引：17，自引：2，他引：17  
用PCR方法配合生化鉴定，从有肺炎症状猪的肺脏及进行性萎缩性鼻炎(Progressive atrophic rhinitis，PAR)症状猪的鼻拭子中分离出66株多杀性巴氏杆菌(Pasteurella multocida，Pm)。然后做了药敏试验，并用PCR方法对这66株Pm进行分型及毒素基因的检测，用豚鼠皮肤坏死试验及小鼠致死试验对产毒素多杀性巴氏杆菌(Toxigenie Pasteurella multocida，T^ Pm)进一步鉴定。结果显示PCR鉴定与生化鉴定Pm结果完全一致；PCR分型表明有46株为D型Pm，18株为A型：Pm，1株为B型Pm，1株无法定型；有8株用PcR检测为T^ Pm；豚鼠皮肤坏死试验及小鼠致死试验对这8株T^ Pm的进一步鉴定也表明均为产毒素菌株。所鉴定的8株T^ Pm都为D型，都分离于有严重PAR症状的猪。  相似文献   

19.
A total of 60 isolates of Haemophilus spp. from chickens, including four reference strains of H. paragallinarum and one of H. avium, were examined for their physiological and biochemical properties. The isolates could be placed into two groups. One group was identified as H. paragallinarum and consisted of 43 isolates including the four reference strains of H. paragallinarum. The other group was identified as H. avium and consisted of 17 isolates including the reference strain of H. avium. H. avium can be differentiated from H. paragallinarum by its possession of the enzymes catalase and alpha-glucosidase, capacity to grow in air, production of acid from galactose, and by the fact that its growth is not improved by the addition of chicken serum. In addition, the majority of H. avium isolates, unlike H. paragallinarum, possess a yellow pigment and produce acid from trehalose.  相似文献   

20.
The virulence of four South African field isolates of NAD-dependent Haemophilus paragallinarum and two field isolates of NAD-independent H. paragallinarum has previously been tested in unvaccinated chickens. In this study, the disease profiles caused by the NAD-dependent isolates of H. paragallinarum in vaccinated chickens were studied. It was shown that the clinical signs induced in the vaccinated chickens were substantially less severe than were those in unvaccinated chickens, as was expected. However, due to the high virulence of the serovar C-3 isolates, clinical signs in the vaccinated chickens challenged with this isolate were still detected. These were as severe as those occurring in unvaccinated chickens challenged with serovar B-1 isolates. Although the clinical signs induced in unvaccinated birds challenged with serovar A-1 were more severe than those occurring when vaccinated birds were challenged with serovar C-3, the overall disease profiles were similar. Substantial clinical signs were recorded in vaccinated birds challenged with serovar C-3. This could be interpreted as vaccination failure if the disease profile obtained in unvaccinated birds is not considered. It was found that a high level of protection was provided by this vaccine against challenge by serovar C-3. The high virulence of this serovar resulted in the development of clinical signs in vaccinated birds. These findings could possibly explain the large number of so-called vaccination failures that are reported in South Africa.  相似文献   

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