Diagnosis and treatment of Campylobacter jejuni outbreak in cultured peacocks

Campylobacter malachi is a bacterial infectious disease of young and adult peacocks caused by campylobacter infection. The disease generally shows a chronic process, and acute cases are rarely reported. In June 2004, 200 30-day-old young blue peacocks raised by a special breeding household in Tancheng County broke out cases characterized by ascites and hepatomegaly. According to statistics, the incidence rate was 26.7%, and the mortality rate was 9.8%. After clinical observation and laboratory diagnosis, the final diagnosis of Campylobacter jejuni infection, and take Chinese and western medicine combined with prevention and treatment measures to control the disease, the diagnosis and treatment are reported as follows.

1 epidemic situation

According to breeders and technicians: the young peacocks hatched by themselves in this farm and grew well after hatching; ascites was found after 25 days of age, initially thought to be colibacillosis, and was mixed with materials and drinking water with a variety of drugs. not only the symptoms were not alleviated, but the number of cases increased rapidly; the incidence reached its peak at about 30 days old, and continued to die.

2 changes of clinical symptoms and autopsy

The sick chicks are mentally tired, depressed and insensitive to external reactions; seriously, they stand stillly, shrink their necks, close their eyes, lose their appetite, have diarrhea at the beginning of the disease, have the desire to drink water, and are covered with loose stools containing pus around the anus. Some pull red thin stool, the abdomen is obviously enlarged, the crown is pale, some peacocks appear acute death, showing a lethargic state or swimming before death. Some sick peacocks become chronic, showing mental malaise, crown hair white, dry, atrophy, visible scale-like dandruff, gradually emaciated, feed consumption reduced. Autopsy of 9 representative dead peacocks showed that most of the dead peacocks had a large amount of ascites in the abdominal cavity, reddish brown hepatomegaly, yellow necrotic foci of different sizes, and different degrees of bleeding or scattered gray-and-white needle-sized necrotic spots on the surface of the liver. Some cases of pulmonary congestion, 2 cases of pulmonary atrophy, 1 case of pulmonary edema, some splenomegaly, a few bleeding points. There are different degrees of bleeding and congestion in the mucosa of muscular stomach, glandular stomach and jejunum. Severe bleeding and catarrhal enteritis in the duodenum, especially in the rectum. The gallbladder is enlarged and the color is yellowish green. The kidney is enlarged and pale, and the myocardium has a yellow necrotic focus.

3Laboratory diagnosis

3.1 microscopic examination of cardiac blood, bile and liver contact smears of dead peacocks showed gram-negative, seagull-shaped, S-shaped, arc-shaped and spiral-shaped.

3.2 isolation and culture of pathogens aseptic liver and bile of dead peacocks were inoculated on blood Agar culture medium respectively. After being cultured for 24 hours in a 42 ℃ culture tank with 10% carbon dioxide, needle-sized, round, smooth, inhemolytic, protruding and almost completely transparent colonies grew on the surface of the culture medium. The above single colonies were selected for pure culture, and the liquid cultures of pure culture bacteria were inoculated into the yolk sac of 8-day-old chicken embryos. Each embryo was inoculated with 0.2mL, a total of 16 embryos were inoculated, and 3 dead embryos were discarded within 24 hours after inoculation. 6 died at 72 hours, and the other 7 died at 72 hours. After autopsy, the chicken embryo showed skin surface hemorrhage and liver necrosis. The allantoic fluid and yolk of dead chicken embryos were collected, and the morphology of the smear staining was the same as that described in "3.1". The same drop of allantoic fluid suspension was placed on the glass slide and observed in the dark field, the bacteria showed spiral movement. Flagella staining microscopic examination showed that there were flagella at one end of the cell.

In the biochemical test, the pure culture of the bacteria was placed under hypoxia for biochemical reaction, and it was found that the bacteria did not ferment carbohydrates such as glucose, fructose, sucrose, etc.; indigo matrix, V.P, M.R.H2S, urea, sodium citrate, malonate, gelatin were all negative; oxidase and catalase test were positive; nitrate reduction was positive. It basically accords with the biochemical characteristics of Campylobacter jejuni.

3.4 in the animal regression experiment, the above allantoic fluid and the liver, bile and spleen of the diseased peacock were taken aseptically, and the suspension diluted into 1 ∶ 5 normal saline was orally inoculated into 2 healthy peacocks at the age of 28 days. the results showed that all the peacocks developed the disease within 24 hours and died within 1 week. The pathological changes and microscopic examination were the same as those of the diseased peacocks mentioned above.

Comprehensive diagnosis: through the above clinical examination, laboratory tests, animal experiments and other means, confirmed as young peacock Campylobacter jejuni infection, due to the limitations of the conditions at that time, did not identify its serotype.

The results showed that the bacteria was sensitive to ampicillin, erythromycin, streptomycin sulfate and sulfamethazine, the bacteriostatic zone was above 15mm, and others had a certain degree of drug resistance.

4 comprehensive prevention and control measures

4.1 isolation, disinfection, and strengthen hygiene management to strictly isolate and raise sick peacocks, the peacock house was disinfected once a week instead of once a week, and the medicine was disinfected alternately with 3% hypochloric acid, 3% peracetic acid and 2% permethoxy. The environment is disinfected with 3% hot alkali water once a day; the sink and food trough are cleaned with disinfectant once a day; fecal dirt is concentrated for harmless treatment; dead peacocks are deeply buried after disinfection; at the same time, feeding and management are strengthened to improve the resistance of peacocks.

4.2 Preventive medication in order to prevent the continued prevalence of the disease, the whole group of assumed healthy peacocks were fed with 500g doxycycline per ton of feed for 5 days, and no new cases occurred after medication.

4.3 for the peafowls with severe disease, each peacock was injected with ampicillin 10mg for 3 days for 5 days, and chloramphenicol aqueous solution was used for 7 days. After 500 g doxycycline per ton of feed was mixed for 5 days, chloramphenicol was used to drink water for 5 days.

Cooperate with the use of traditional Chinese medicine. 100 grams of cooked land, Angelica sinensis, white chrysanthemum and Chinese wolfberry, 70 grams each of Bupleurum, Qingzi, Cassia, Plantago asiatica, Scutellaria baicalensis and Fructus Rehmanniae, fried in water for 100 young peacocks, 1 dose a day for 5 days.

After treatment, the condition improved gradually after 5 days. Except for a few severe cases, the death could not be controlled, and the rest 10 days basically returned to normal.

5 Summary

5.1 through epidemiological, clinical and pathological tests and pathogen isolation and identification, it was confirmed that the infectious disease in peacocks was caused by Campylobacter jejuni infection.

5.2 Comprehensive measures should be taken to treat the disease. Drug selection is based on drug sensitivity test. From the results of this drug sensitivity test, Campylobacter jejuni has varying degrees of resistance to many antibiotics, which may be due to the fact that Campylobacter jejuni is resistant to some antibiotics due to unscientific and unreasonable drug use in the farm for a long time. The reason for the poor effect of early treatment after infection. Therefore, in the diagnosis of the disease, samples should be taken for bacterial culture, identification, drug sensitivity test of pathogenic bacteria, selection of specific drugs or combination of drugs, there is a significant therapeutic effect.

5.3 Campylobacter jejuni is a zoonotic disease, carried by a variety of animals, it is a conditional pathogen, when animals are stressed (such as sudden change, cold stimulation, air pollution, cold, etc.), the resistance decreases, which can induce the disease. The main reason for this disease is due to negligence in feeding and management. at that time, light rain fell for several days, the air was humid, the temperature dropped, and no timely measures were taken to make some young peacocks catch a cold and decrease their immunity, thus causing Campylobacter jejuni to take advantage of the opportunity to multiply in peacocks. The main measures to prevent the occurrence of this disease: ① to strengthen the usual feeding management to improve the resistance of peacocks; ② to pay attention to health and epidemic prevention work to put an end to the spread of disease; ③ reasonable and scientific use of antibiotics to avoid or reduce drug resistance of bacteria.