European foulbrood of open brood
European foulbrood (benign foulbrood, open foul broth, acid foulbrood, paragnilets) is an infectious disease of bee colonies, which causes their weakening due to the mass death and decay of 4-less frequent 7-day-old bee larvae.
The disease is common in all countries with developed beekeeping. In the northern and middle regions occurs more often than in the southern.
Disease in the past reduced the profitability of each sick family by 20-80%. Since the widespread use of antibiotics and sulfamides, losses from shortages of honey have decreased significantly, but the cost of medical treatment has increased.
The causative agent of the disease.
Most of the causative agents of the disease are Streptococcus pluton, you. alvei, Str. apis, you. orpheus are considered as a secondary microflora, complicating the course of the disease.
S. pluton in smears of tissues is located alone, in pairs, chains in the form of lanceolate cocci in the size of 0.7-1.5 microns; Gram-positive, individual cells – gram-negative; grows on special media at a temperature of 35 њ, pH 6.6. Streptococcus has a capsule, which is dyed according to the method of Klimberg, Tomacek and Novelli.
On a dense special nutrient medium, streptococcus forms in 24-48 hours round pearly white, granular colonies with a diameter of 1-1.6 mm. They break down glucose and fructose without gas. Do not split sucrose, galactose, maltose, raffinose, mannitol, sorbitol, starch.
In dried form at room temperature, streptococcus lasts 17 months, in honeycombs and honey of a bee family – not less than a year; in sunlight perishes: in the dried state after 21-31 hours, in water after 5-6 hours, in honey after 3-4 hours; A 2% solution of carbolic acid kills it after 6 hours (White), formalin vapors (50 ml of sales formalin per 1 m3 at 40 њ C) for three hours; A 2% aqueous solution of quinazole for 10 minutes
The pathogen of the disease is pathogenic for wasps and non-pathogenic for humans and warm-blooded animals. Larvae of bees are susceptible to the disease from the fourth day onwards. The incubation period lasts 1 / 2-3 days. The source of the disease are sick families. The spread of the disease is promoted by bee-thieves, wandering bees, flying swarms, migrations, long breaks in honey, weak warming of families, lack of feed, close-breeding. On the contrary, improving weather conditions and abundant allocation of nectar and pollen in nature leads to a significant decrease in the percentage of diseased larvae, and in strong families, rapidly clearing honeycombs from diseased larvae, leads to recovery.
The course and symptoms of the disease.
The disease occurs in the spring and can last the entire season, while the family has an open brood.
The family can be afflicted to a weak degree when sick larvae 3-5 in the entire nest, and in the strong, when 10-25% or more of larvae are affected. In these cases, the larvae are also found in sealed cells. When examining the nests of sick families, they see broods of different ages in honeycombs; next to the cells with a healthy brood there are cells with dead larvae.
The pearlescent, white, shiny color of healthy larvae becomes yellowish when they become infected with foulbrood. Then the dead larvae acquire a brownish brown color. In the process of disease, the larvae move from their usual places and occupy a diverse position in the cells. They can be at the bottom of cells, on their walls and in the mouths of cells. Sometimes the rotting mass of the larvae stretches, as in the case of American foulbrood, but with shorter, thick, easily tearing threads. The smell of dead larvae resembles the smell of sour apples and the acid of rotting meat.
Diagnosis.
The disease is diagnosed by the variety of the brood, the death of the open larvae, the yellow color of newly infected larvae, the smell of rotting mass, the lack of ductility, the diverse position of the larval corpses in the cells, the weak attachment of dried corpses to the cell walls.
In a bacterioscopic study of recently lost larvae, Str. pluton. In smears, taken from a rotting mass that produces a nasty putrid smell, you are usually seen with controversies. alvei, and in smears from the body of larvae with a sour smell – Str. apis. Often a mixed microflora is found. To clarify the diagnosis, bacteriological and serological tests are carried out, which is especially necessary for diagnosing a mixed infection of European and American foulbroods.
Prevention.
In the apiary, only healthy, strong, productive families that are obtained through unrelated cross-breeding are propagated and propagated. Families, slowly developing, ill, poorly wintering, reject. Each bee family from early spring is provided with honey in an amount of up to 15 kg and perga in 2-3 honeycombs. In areas that have long breaks in honey collectors, they produce honey-bearing crops flowering during this period, or the apiary is transported to another locality rich in honey plants. Also warn the skid of the disease from unsuccessful apiaries. For preventive purposes, families are given a nutritional top dressing at the end of May. To an ill-affected apiary, quarantine is imposed until the disease is completely eliminated.
Control measures.
When a disease is detected, the entire apiary is examined to identify sick families. Samples are taken from sick families and sent to a laboratory for research. Nests of newly infected families are reduced, well-insulated, weak families are connected and treated.
Families containing infected larvae in sealed cells are distilled into disinfected hives on honeycombs from healthy families or to integral sheets of artificial wax. They are treated with one of the following drugs. At distilled families, the queens are replaced with mature queen cells or uterus, bred in healthy families. Strong families, in whom the disease is found in the fall, is transplanted to honeycomb with honey from healthy families. Treatment is the same as with American foulbrood. In addition, with European foulbrood, levomycetin, a white crystalline powder, soluble in water (1 g per 1 liter of syrup), streptomycin (per 1 liter of syrup 200,000 units) and penicillin (900,000 units) can be used to make medicinal syrup.
Disinfection.
The beehive, frames, honeycombs, canvases, feeders, mother cells and other equipment and materials from distilled sick families are disinfected. Before the hive is disinfected, the frames are cleaned of wax and propolis. Wooden objects (beehives, platens, frames), metal (uterine cells, pots, chisels, knives) and glass (feeders, plates, bottles) are disinfected with 2% solution of fly ash or 1% solution of laundry soda. Bathrobes are disinfected by boiling in water.
The honeycomb with the corpses of the larvae and those who are busy with pergolas are re-heated to wax. Cells free from honey, pepper and brood are disinfected by continuous moistening with a 4% aqueous solution of formalin, 4% chloramine for three hours or 2% solution of quinazole for 30 minutes.
With the establishment of bee diseases at the bee, both American and European foulbroods are held as in American foulbrood.
(1 votes, average: 5.00 out of 5)European foulbrood of open brood