[Weiboxin] teaches you how to determine whether poultry are infected with Riemerella anatipestifer.

The recent emergence of Pasteurella multocida in duck flocks has inflicted substantial losses on the poultry industry, prompting growing public attention. Let’s begin by gaining a better understanding of this issue.

Riemerella anatipestifer is a Gram-negative bacterium. To date, 25 serotypes of Riemerella anatipestifer have been reported. The disease is a highly prevalent infectious illness that can infect waterfowl such as ducks and geese, as well as chickens and wild birds. 
 

As of mid-month, the strains isolated by the laboratory from chicken embryos and commercial broilers were predominantly serotype 1 and YB1, with serotype 1 accounting for more than 90% of these two serotypes; strains isolated from caseous material in the oviduct were mainly serotype 10, with serotypes 5, 1, and 7 also detected to varying degrees. In terms of pathogenicity, clinical isolates were more capable of reproducing caseous lesions in the oviduct, whereas strains derived from chicken embryos exhibited relatively weaker virulence. However, a key premise here is that when it causes disease on its own, its virulence is relatively low; this does not apply in cases of co-infection with Escherichia coli, nor in the presence of classical swine fever, variant strains of infectious bursal disease, H9 subtype avian influenza, infectious bronchitis, or immune stimulation from vaccination.

Pasteurella multocida ( RA primarily infects waterfowl, especially ducks and geese. However, according to data from recent years, Riemerella anatipestifer (RA) also infects chicken flocks; based on the species currently affected, High detection rates were observed in white-feathered broiler breeding stock, commercial white-feathered broilers, and layer chickens; native Chinese chickens were also detected, but at a much lower rate than the former groups. 
 

Infectious age: Clinical disease can occur as early as the first seven days of life, with pathological changes characteristic of the “three inflammations.” In layer chickens, infection typically occurs between 20 and 180 days of age, with the earliest cases reported at 20 days and the latest at 180 days; the highest detection rates are observed in the 40–60-day and 60–80-day age groups. The majority of cases occur during the first half of the year, with a marked increase starting in October. In broilers, infections with Riemerella anatipestifer have become significantly more common over the past two years in broiler production in Shandong, Liaoning, Hebei, and other regions. The level of management and the appropriateness of the medication regimen can lead to variations in both the severity of the disease and the age at which clinical signs appear.

1. Among bacterial diseases, co-infection with Escherichia coli is the most common, occurring in nearly 100% of cases. This is because, in every case where Riemerella anatipestifer has been detected in ducks, E. coli has also been detected without exception.

2. Regarding viral infections: the highest co-infection rate is observed with variant strains of infectious bursal disease (80%), followed by infectious bronchitis, H9 subtype avian influenza, and infectious anemia, while Newcastle disease exhibits a relatively lower co-infection rate.

3. A clinical analysis of 42 cases of Riemerella anatipestifer in ducks revealed the following mixed-infection patterns: single-pathogen infections accounted for 30%, while mixed infections accounted for 70%; among the mixed infections, those involving two pathogens represented 33.3%, three pathogens 16.7%, four pathogens 13.3%, and five pathogens 6.7%. The predominant mixed pathogen was Escherichia coli, accounting for 50% of cases, followed by H9 avian influenza virus, infectious bronchitis virus, and Mycoplasma.

1. In the early stages, respiratory symptoms predominate, primarily manifesting as a wet cough, mild snoring, and poor response to treatment, with prolonged persistence despite ongoing therapy. 
 

2. Head swelling may occur, but the incidence is much lower than with influenza. 
3. Prominent clinical signs include depression, emaciation, dry claws, closed eyes with neck retraction, ruffled feathers, paralysis, and recumbency with immobility. 
4. In most flocks, mortality persists for an extended period, sometimes even until the birds are ready for market, with suboptimal therapeutic efficacy of medications. Moreover, there are instances where the flock appears clinically healthy on the surface, yet daily mortality and culling rates remain unacceptably high. 
5. Concurrent environmental stressors prior to disease onset can markedly accelerate the rate of disease progression and increase mortality, which may also be closely associated with the activation of other pathogens.

6. Swelling of the tarsal joint in the leg, with contents ranging from purulent to caseous. 
 

1. The pathogenicity of chicken-derived strains is weaker than that of duck-derived strains, and there are differences in pathogenicity among different strains.

2. Air sacs and the larynx are more susceptible to viral infection than muscles, Cloacal inoculation method It is associated with a high rate of tubal lesions and severe symptoms.

3. Chicks remain colonized for a prolonged period, Affects production performance; semen can be transmitted, It can be transmitted vertically.

4. With tubal occlusion, joint lesions, Gelatinous embryos, trichomoniasis, and other major clinical symptoms.

Identification of Pasteurella multocida in ducks typically requires specialized laboratory testing; however, the following preliminary observation methods can help farmers remain vigilant: 
 

1. Observation of clinical signs: Poultry infected with Riemerella anatipestifer may exhibit depression, reduced appetite, ruffled feathers, coughing, sneezing, and respiratory distress. Although these signs are non-specific, their concurrent occurrence in a flock should raise strong suspicion of the disease.

2. Pathological examination: Perform necropsy on dead poultry to examine for lesions such as pericarditis, perihepatitis, and air sac inflammation. These lesions are common pathological features of infection with this bacterium.

3. Bacterial Isolation and Identification: The most reliable method for accurately identifying Riemerella anatipestifer in ducks is bacterial isolation and identification. This involves isolating the bacterium from clinical samples and conducting biochemical, serological, or molecular biological tests to confirm the identity of the pathogen.

3-1. Bacterial Isolation and Culturing: *Riemerella anatipestifer* was isolated from the affected tissues and subjected to isolation and cultivation on a specific culture medium. The bacterium exhibits vigorous growth on chocolate agar, with colonies that are grayish-white, semi-transparent, circular, and slightly raised.

3-2. Serological tests: These assays measure antibody levels in the serum of affected animals and commonly include agar gel diffusion, tube agglutination, and slide agglutination tests.

3-3. Nucleic acid detection: Detection of DNA from Riemerella anatipestifer by PCR technology, a method that exhibits high sensitivity and specificity.

3–4. Gene sequencing: Determination of the gene sequence of *Riemerella anatipestifer* for identification and traceability.

3–5. Indirect immunohistochemistry: This method uses immunohistochemical techniques to detect Riemerella anatipestifer antigen in tissue samples, and it is characterized by high specificity and the absence of false-positive results.

As a professional reagent manufacturer, Weiboxin Biotechnology can provide more accurate and more sensitive detection products—namely, the nucleic acid detection kit for Riemerella anatipestifer (RA). Conduct PCR testing to help poultry farmers more quickly and accurately identify Riemerella anatipestifer, thereby reducing of the farmers Loss.

For animal disease testing reagents, please choose the Weiboxin brand.

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Official consultation phone numbers: 020-66377266 / 135 3988 6748, Ms. Dai

Guangzhou Weiboxin Biotechnology Co., Ltd. is located in the national-level innovation park—Guangzhou Science City—and is a provincial-level “Little Giant” high-tech enterprise specializing in the forward R&D, manufacturing, sales, and technical services of diagnostic reagents for animal epidemics. The company is also recognized as a “Contract-Honoring and Credit-Keeping Enterprise” by Guangdong Province and a provincial demonstration unit for intellectual property, as well as a industry–university–research collaboration base of Guangdong Food and Drug Vocational College and an executive director unit of the Veterinary Diagnostic and Biological Products Committee of the Guangdong Society of Animal Husbandry and Veterinary Medicine. It has been designated as an innovative, high-potential enterprise by multiple research institutes, including the Entrepreneurship College of Jinan University in Guangdong Province, and has been awarded the titles of “Specialized, Refined, Distinctive, and Innovative” enterprise at both municipal and provincial levels. The company has received the “Most Investment-Valuable Enterprise” award and the annual title of “ASF and Swine Disease Testing Service Provider.” In addition, it has obtained approval numbers from the Ministry of Agriculture and Rural Affairs for veterinary drug products: Veterinary Drug Registration No. 191438923 (Fluorescent PCR Test Kit for African Swine Fever Virus), Veterinary Drug Registration No. 191438213 (ELISA Antibody Test Kit for Porcine Reproductive and Respiratory Syndrome Virus), and Veterinary Drug Registration No. 191438875 (Blocking ELISA Antibody Test Kit for Classical Swine Fever Virus). The company was awarded the Excellence Prize in the Growth Category of the Biopharmaceutical Industry at the 11th China Innovation and Entrepreneurship Competition, the Provincial Second Prize in the Growth Category of the Nanotechnology Industry Technology Competition within the Science and Technology Innovation and Entrepreneurship Contest, and the National Third Prize in the Growth Category of the National Finals of the Nanotechnology Industry Technology Innovation Special Competition at the China Innovation and Entrepreneurship Competition. Furthermore, it has consecutively received the A-Level Tax Credit Honor Certificate, the Four-Star Trademark Brand Certification, and the Two-Integration Management System Assessment Certificate each year, along with ISO 9001 International Quality Management System Certification, ISO 14001 International Environmental Management System Certification, and GMP certification from the Ministry of Agriculture. Since its establishment, the company has been granted a total of 24 patents, including 5 invention patents, 15 utility model patents, and 4 design patents, as well as more than ten trademarks.

The company boasts robust technical capabilities and a team of world-class professionals, including dozens of masters, doctors, and returnees who studied abroad, as well as numerous senior-title technical experts. Currently, the company’s primary focus is on the research and development of molecular diagnostic reagents. Its core R&D team has developed more than 600 products spanning molecular diagnostics and immunoassays, including public-health–oriented fluorescent PCR test kits, animal disease–control–oriented fluorescent PCR test kits, clinical and research–grade fluorescent quantitative PCR kits, and transgenic identification test kits (ZL2006). The company has also established a nationwide distribution network covering more than ten major cities, such as Beijing, Shanghai, Hangzhou, Nanjing, Xi’an, Chongqing, Lanzhou, Zhengzhou, and Qingdao.

Looking ahead, Weiboxin will remain steadfast in its commitment to continuously enhance product quality and service standards. Leveraging a rapid and efficient research platform and abundant biomedical resources, we will conduct extensive and in-depth R&D and scientific research in the biomedical field, thereby contributing to human health and advancing life sciences. Quality is our lifeline; innovation is our soul. Upholding this guiding principle, we will relentlessly strive to become the premier supplier of rapid diagnostic reagents and instruments.