Outbreaks Of Fowl Cholera Research Articles

Recurrent Outbreaks of a Cutaneous Form of Pasteurella multocida Infection in Turkeys

Cutaneous infection caused by Pasteurella multocida was diagnosed in a flock of seven thousand 17-to-22-week old male turkeys. The affected grow-out facility had an annual outbreak of fowl cholera, in which a cutaneous infection ventral and lateral to the tail was the predominant lesion. P. multocida serotypes 1 and 14 were the predominant isolates. The exact source of the infection was not determined.

Transmission of Pasteurella multocida on California Turkey Premises in 1988-89

Restriction endonuclease analysis (REA) of whole-cell DNA was used to determine possible sources of Pasteurella multocida for each outbreak of fowl cholera occurring in turkey flocks in eight commercial poultry companies in California from October 1988 to September 1989. Over this period, 179 isolates of P. multocida were obtained from dead turkeys in 80 meat and breeder flocks on 43 premises. P. multocida was isolated from wildlife on five premises. Isolates were characterized by subspecies, serotype, presence of plasmid DNA, and REA type. In 52 (65%) flocks, all isolates of P. multocida had the same REA pattern as the M9 live vaccine strain following digestion of DNA with the restriction enzyme SmaI. Field strains of P. multocida were obtained from 27 (34%) flocks, and one flock (1%) yielded both M9 and a field strain of the organism. REA of field strains of P. multocida revealed 17 different SmaI REA types. Based on matching SmaI REA types, potential sources of P. multocida were identified for 15 of the 28 flocks infected with field strains of the organism, and transmission between turkey premises was a possibility in only seven flocks.

Restriction Endonuclease Analysis of Pasteurella multocida Isolates from Three California Turkey Premises

Three California turkey premises that had repeated outbreaks of fowl cholera were studied for periods of 2 to 4 years. Using biochemical, serologic, plasmid DNA, and restriction endonuclease analyses of isolates of Pasteurella multocida from turkeys and wildlife on the premises, strains of the organism were found to be enzootic on two of the premises. On the third, a variety of strains of P. multocida were isolated from fowl cholera outbreak flocks.

The First Outbreak of Fowl Cholera in Muscovy Ducks(Cairina moschata) in Japan.

The first outbreak of fowl cholera occurred in a flock of Muscovy ducks (Cairina moschata) in Okinawa Prefecture of Japan in November 1990. Fifty (25%) of 200 birds in a farm died of an acute disease. Remaining birds recovered after treatment with oxytetracycline. Pasteurella multocida subsp. multocida was isolated in pure culture from all tissues tested from two dead birds. Serovars of the isolates were identified as Carter's capsular type A. Heddleston's type 3.4.12, and Namioka's type 5:A which have not been demonstrated in Japan. Pathologically, multiple necrosis and bacterial aggregates were prominent in several organs, particularly in the liver. The isolate killed chickens when inoculated intravenously at a concentration of 10(8) colony forming units.

Interaction of Naturally Occurring Aflatoxins in Poultry Feed and Immunization Against Fowl Cholera

A total of 1,175 poultry feed samples originating from different farms were analyzed for aflatoxin. Poor growth rate and reduced egg production were the main complaints. The rate of contamination with aflatoxin ranged from 10 to 54% of all samples. Of samples examined 30.7% proved positive for aflatoxin with a concentration ranging from 1 to 2,000 ppb. Outbreaks of fowl cholera were diagnosed on two farms where aflatoxin was detected in the rations used. The impact of aflatoxin in the feed on the efficacy of immunization against fowl cholera was monitored by a hemagglutination test and the titers of the involved farms were compared with experimental groups fed on aflatoxin-free rations and vaccinated with the same polyvalent fowl cholera bacterin. The antibody titers of the experimental groups were 4 to 15 times higher than those of the involved farms.

Serologic Associations between Fowl Cholera and Other Diseases

As part of a case-control study designed to identify fowl cholera risk factors, 2087 blood samples were collected from 71 California meat-turkey flocks. Samples were tested for antibodies to three mycoplasmas and four viruses pathogenic for turkeys. Flocks that had antibodies to Newcastle disease virus and/or Mycoplasma meleagridis had an increased risk of having an outbreak of fowl cholera. This information should prove useful for fowl cholera control programs in meat turkeys.

Molecular epidemiology of Pasteurella multocida in turkeys

Summary Pasteurella multocida isolated from turkeys during an outbreak of fowl cholera was characterized by serotype and heterogeneity of genes encoding rrna (ribotype) to investigate the epidemiology of the organism. Isolates were collected between October 1985 and July 1986. The M9 or Clemson University fowl cholera vaccine-like strain was detected in 17% of the flocks with fowl cholera. One particular strain, isolated only from breeder flocks, was recovered from 7 of the 10 breeder flocks examined in this study. Intracompany transmission appeared to be common, implying a failure in biosecurity. Circumstantial evidence indicated that in the field, the incubation period of P multocida in a turkey flock may be between 2 to 7 weeks. Wildlife did not appear to be an important reservoir of P multocida for turkeys during this study period. Ribotyping results tended to discount several of the possible interflock transmissions, as suggested by examination of serotyping results alone; however, serotyping in combination with ribotyping proved helpful in understanding the epidemiology of P multocida in turkeys.

Cotrol study of fowl cholera outbreaks in meat turkeys in California from August 1985 through July 1986

SUMMARY From Aug 1985 through July 1986, 720 meat turkey flocks on 160 California premises were monitored and outbreaks of fowl cholera (Pasteurella multocida) were investigated. Data from 43 outbreak (case) flocks were compared with data from 43 nonoutbreak (control) flocks. Outbreak flocks, compared with control flocks, were more likely to be located on premises with higher maximal bird capacity and history of fowl cholera outbreaks. The overall impression was that flocks in larger, newer, more intensively managed premises were at greater risk of fowl cholera outbreaks than were other flocks.

Fowl Cholera in California Multiplier Breeder Turkeys: 1985-86

One hundred twenty-nine multiplier breeder turkey flocks on 45 premises in California were monitored for outbreaks of fowl cholera (FC) (Pasteurella multocida) for 1 year (Aug. 1, 1985, through July 31, 1986). Fourteen (11%) flocks on 10 (22%) premises experienced outbreaks. Nine (64%) outbreaks occurred in the fall or winter. FC-outbreak flocks had significantly shorter lay cycles (24.6 weeks vs. 27.9 weeks) and correspondingly lower total egg production per hen (84 eggs vs. 103 eggs) than non-outbreak flocks. A case-control investigation was performed on 11 FC-outbreak (case) flocks, and nine non-outbreak (control) flocks. Case flocks were located statistically closer to other livestock species than were control flocks (0.28 miles vs. 0.68 miles) and were more likely to utilize on-farm disposal of dead birds.

Homogeneity of Characteristics of Pasteurella multocida Isolated from Turkeys and Wildlife in California, 1985-88

Five hundred twenty isolates of Pasteurella multocida, collected in California from September 1985 to November 1988, were characterized in the laboratory. Characteristics examined included serotype, capsular type, biotype (subspecies), and possession of plasmid DNA. Three hundred thirty-three isolates recovered from turkeys dying from fowl cholera, 88 isolates from liver turkeys in flocks with fowl cholera outbreaks in the recent past, and 99 isolates from wildlife captured on fowl cholera-outbreak and non-outbreak turkey premises were studied in this manner. Characteristics were fairly homogeneous among isolates, especially those obtained from turkeys. The majority of isolates were serotype 3,4, capsular type A, subspecies multocida, and lacked plasmid DNA. Common serotypes of isolates from turkeys and wildlife sampled on the same premises were noted in eight of 13 cases examined.

Preparation and use of an autogenous bacterin against fowl cholera in red partridges ( Alectoris graeca)

Pasteurella multocida serotype A 8 was isolated from red partridges ( Alectoris graeca) in an outbreak of fowl cholera in Morocco. An autogenous bacterin was prepared and then used experimentally. Birds were vaccinated at 6 and 8 weeks of age and challenged intramuscularly 3 weeks after the second vaccination. The two aluminium hydroxide bacterins, prepared on different culture media (Trypticase soja agar and brain-heart infusion broth), conferred significant and similar immunity in partridges giving 60% protection. All unvaccinated controls died within 24 h.

Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from turkeys.

One hundred fifty-three isolates of Pasteurella multocida, representing the causative agent of 95% of all known outbreaks of fowl cholera occurring in California meat and breeder turkeys from August 1985 through February 1987, were examined for susceptibility to antimicrobial agents. Of the 153 isolates, 6 were shown to be resistant to one or more antimicrobial agents. Of the six resistant isolates, five contained R plasmids. All but one of the R plasmids were small (6 to 7 megadaltons) and nonconjugative, encoding resistance to tetracycline or kanamycin, streptomycin, and sulfonamides; the other was large (70 megadaltons) and conjugative, transferring resistance to kanamycin, streptomycin, sulfonamides, and tetracycline to P. multocida and Escherichia coli. The three plasmids encoding resistance to tetracycline alone appeared identical.

Characteristics of Fowl Cholera Outbreaks in Turkeys in Georgia in 1986

Information was gathered from 64 cases of fowl cholera (FC) in turkey flocks through diagnostic case records, flock records, and telephone and mail surveys. Forty-five cases came from flocks of commercial turkeys, of which 15 were presented twice, and four came from mature breeder flocks. The prevalence of FC was 18.0% of commercial flocks and 14.7% of breeder flocks at risk. The average age at first diagnosis of FC was 90 days in commercial turkey flocks and 32 weeks 5 days in breeder flocks. Acute mortality was the most common presenting complaint, with a 0.37% average mortality in commercial flocks on the day of first presentation, 0.80% in commercial flocks presented a second time, and 0.43% in breeder flocks. Pasteurella multocida was cultured from 69.8% of the 361 tissue samples submitted from these cases. Novobiocin, penicillin, and chlortetracycline (CTC) had the greatest in vitro activity against isolates. Serotype 3-cross-4 was found in all 18 commercial flocks from which isolates were typed. All breeder flocks and 88.6% of commercial flocks were vaccinated before disease onset. Flocks were treated for an average of 14.3 days, most commonly with high levels of sulfadimethoxine and/or CTC. Body weights of affected birds were comparable to those of birds in unaffected flocks, but mortality and feed efficiency were worse.

Pasteurella multocida Recovered from Live Turkeys: Prevalence and Virulence in Turkeys

Swabs of the oropharynges of 801 live turkeys (621 meat birds and 180 breeders), collected from 15 flocks that had experienced an outbreak of fowl cholera and from 12 non-outbreak flocks, were screened for the presence of Pasteurella multocida. Turkeys from outbreak flocks were sampled within 2 to 9 weeks of the outbreak. Forty-nine isolates of P. multocida were recovered from turkeys in 11 of the outbreak flocks, and none were recovered from turkeys in non-outbreak flocks. Isolation rates varied from 0 to 72% of turkeys sampled in a flock. Nineteen isolates were tested for virulence by injecting them intravenously into turkeys, and 14 were lethal. Results demonstrated that for purposes of disease control, meat birds in fowl-cholera-outbreak flocks should be considered carriers of potentially virulent P. multocida for the life of the flock.

Comparison of Pasteurella multocida Serotype 3, 4 Isolates from Turkeys with Fowl Cholera

Nine isolates of Pasteurella multocida serotype 3,4 were isolated from turkeys that had been vaccinated against fowl cholera but that subsequently experienced outbreaks of fowl cholera. These isolates were compared with the CU vaccine strain. Characteristics examined were antimicrobial susceptibility profiles; carbohydrate fermentation; production of bacteriocin, siderophore, and hemolysin; resistance to serum complement; membrane proteins; enzyme activities; presence of plasmids; transferability of R-plasmids; and pathogenicity. Differences were observed between the CU strain and virulent isolates of P. multocida serotype 3,4 for resistance to serum complement, presence of plasmids, hemolysis, membrane proteins, and pathogenicity. Other parameters compared did not differ significantly between the two groups. The presence of plasmids and resistance to the lytic action of complement of the isolates of P. multocida serotype 3,4 correlated with the mortality rates caused by these bacteria.

Pasteurella multocida in Wild Mammals and Birds in California: Prevalence and Virulence for Turkeys

Samples collected from the oropharynx of wild mammals and birds trapped on 36 turkey farms in California were evaluated for the presence of Pasteurella multocida. A total of 966 animals were collected from 18 premises that had experienced an outbreak of fowl cholera within the past 2-8 months; samples were collected from 16 of these 18 premises within 2-8 weeks of outbreak notification and while the infected flock was still present. A total of 939 animals were trapped from an additional 18 premises that had not reported any outbreaks of fowl cholera within at least 4 months, if ever. Forty-eight isolates of P. multocida, of a variety of somatic serotypes, were recovered from 6 species of mammals and 3 species of birds. On only 2 of 7 premises was the somatic serotype of the isolates obtained from wildlife the same as the isolate obtained from tissues of turkeys that had died of fowl cholera on the same premises. Tests for virulence to turkeys were conducted with 31 of the isolates. Seventeen of these isolates caused mortality in turkeys. Wide ranges in mortality rates and median times to death were observed.

A Descriptive Study of Fowl Cholera in California Meat Turkeys: August 1985-July 1986

One hundred sixty meat-turkey premises in California were monitored for outbreaks of fowl cholera from August 1985 through July 1986. Nearly 27 million turkeys in 720 flocks were at risk during the year. Fifty-three flocks of approximately 3 million turkeys on 34 different premises experienced confirmed fowl cholera outbreaks. The epidemic curve for the year indicated that the majority of outbreaks occurred in the late summer and fall, particularly in October. The incidence of outbreaks during this time was not significantly associated with seasonal variation in the size of the turkey population. The mean flock age at outbreak was 10.8 weeks, with a range of 5-18 weeks.

An outbreak of fowl cholera in wild ducks (Rosyibilled pochard) in Japan.

An outbreak of fowl cholera in wild ducks (Rosyibilled pochard) in Japan.

An outbreak of fowl cholera in green pheasants (Phasianus colchicus) in Japan.

An outbreak of fowl cholera occurred in a green pheasant (Phasianus colchicus) flock at a pheasantry in Saitama prefecture of Japan in February of 1984. Twenty-eight (19%) of 150 birds in the flock died of an acute disease. Pasteurella multocida was isolated in pure culture from hearts, lungs, livers, kidneys and spleens of three representative dead birds. Serovars of the isolates were identified as Carter's capsular type A, Heddleston's type 3, and Namioka's type 8, 9:A. Macroscopically, multiple necrotic foci were observed in livers and spleens, and hemorrhages in small intestines. Microscopically, multiple areas of necrosis, bacterial aggregates and moderate heterophilic infiltration were apparent in livers and spleens. Bacterial aggregates were also apparent in hearts and lungs. Hyperemia was apparent in the lungs, kidneys and spleens. Congestion and bacterial emboli were observed in small intestines. These etiological and pathological findings indicated that the infection was typical fowl cholera. This is the first report on the occurrence of fowl cholera in the green pheasant, which is an indigenous bird in Japan.

Possible Genetic Variation in Resistance of Turkeys to Erysipelas and Fowl Cholera

Natural disease outbreaks of erysipelas and fowl cholera occurred in several lines of turkeys maintained for genetic studies. There were line differences in mortality during both outbreaks, suggesting that there is genetic variation in resistance to these diseases. A line developed by selection for increased egg production had a higher mortality rate from fowl cholera than did the randombred control line from which it was developed. Both the egg line and its control line had a lower mortality rate in the erysipelas outbreak than did a line selected for increased growth rate. Both diseases induced high mortality in a line selected for increased growth.