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1.
In this study tracheal swabs and air sac biopsies of 68 raptors of different species that were found injured or debilitated in Germany were investigated for the occurrence of mycoplasmas. Mycoplasma meleagridis, Mycoplasma falconis, Mycoplasma buteonis, Mycoplasma gypis and five mycoplasma isolates not identified so far could be isolated from 32 (47%) birds. Mycoplasma meleagridis could be detected in five birds. These birds did not show clinical signs or histopathological alterations in air sac biopsies related to the infection.  相似文献   

2.
The attempted immunization of 53 female Broad Breasted White turkeys with five weekly 1.0 ml injections of viable Mycoplasma meleagridis, when combined with insemination with M. meleagridis infected semen, did not produce immunity but only imposed additional infection. This was detrimental to the offspring by increasing the incidence and severity of air sac lesions.  相似文献   

3.
Lesions caused by Mycoplasma meleagridis were followed in one hatch of turkeys from one day to 20½ weeks of age. Air sac lesion incidence increased from 20% at one day to 44% at six weeks of age with a slow decline to 10% at 10 weeks of age. Lesions were detectable on careful examination at 10-20% level to 20 weeks of age on laboratory examination, but at 20½ weeks only 0.07% lesions were found in 1000 turkeys from the same hatch.

Air sac lesion severity, based on an arbitrary 0.5,1,2,3,+scale, increased in intensity and spread of air sac involvement from a mean of 1.5 at day old to 2.5 at five weeks of age. This declined to 1.0 at 10 weeks of age and lesions became progressively more faint until careful examination was necessary to detect them in birds 15 weeks and older. The latter would not be considered as a cause of total condemnation.

The percentage of Mycoplasma isolations from the respiratory tissues were much higher in birds exhibiting air sac lesions than those in which no typical air sac lesions were visible, as follows. air sacs 51.6 vs. 2.9, lungs 43.3 vs. 4.0, trachea 47.2 vs. 4.6, sinus 38.5 vs. 19.0.

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4.
The thoracic air sacs of poults at one day of age were examined to compare those of normal, saleable poults with those of sibs culled1 at hatching at three stages in the laying season. Lesions of airsacculitis were recorded and the air sacs were cultured for mycoplasma. Impression smears of the thoracic air sacs were stained with rabbit anti-Mycoplasma meleagridis serum conjugated with fluorescein isothiocyanate and examined to determine the location and infection rate of the organism. M. meleagridis were observed closely associated with or within epithelial cells of the air sac; within mononuclear cells and as extracellular “microcolonies”. The lesion and infection rate of cull poults in most hatches exceeded that of normal poults and infection with M. meleagridis was more often expressed (as a lesion) in cull than in normal poults.  相似文献   

5.
As a result of temperature differential dipping of turkey eggs in 715 p.p.m. of tylosin or 1000 p.p.m. spiramycin in tap water, air sac lesions caused by M. meleagridis were reduced 87% and 72%, and the M. meleagridis isolations were reduced 85% and 84% respectively.  相似文献   

6.
A comparative study of seven isolates of Mycoplasma meleagridis indicated that they were indistinguishable morphologically. Two isolates, E2 and 8M92, induced hemagglutination of red blood cells of several different species while the others did not. Metabolic inhibition, growth inhibition and growth precipitation tests revealed minor differences among the seven isolates. According to these differences, isolates were divided into three groups: antiserum-sensitive isolate 1 466, less sensitive isolates N, 8M92, RY3, 529 and E2 and insensitive isolate 1940. One dimensional polyacrylamide gel electrophoresis of cell proteins revealed that all isolates of M. meleagridis had virtually identical patterns and that they were electrophoretically distinct from Mycoplasma gallisepticum and Mycoplasma synoviae. When nonhemagglutinating isolate N, and hemagglutinating isolate E2 were examined by simple immunoelectrophoresis, no differences were detected. However, minor antigenic differences were detected between the two strains by means of two dimensional immunoelectrophoresis.  相似文献   

7.
Adult male turkeys were exposed to Mycoplasma gallisepticum isolate 1010 by either intratracheal inoculation, intrasinus inoculation, intranasal inoculation or by contact with inoculated turkeys. The symptomatic, serologic, and pathologic responses to the different types of exposure were compared. Tracheitis occurred only in birds exposed intratracheally or by contact, and sinusitis occurred only in birds exposed via the sinuses. Antibody titers, determined by hemagglutination-inhibition and tube agglutination tests, were initially higher in turkeys exposed by intratracheal and intrasinus inoculation than in those exposed by other means. There were no appreciable differences among the four groups in incidence or severity of air sac lesions.

In addition, the effects of intrasinus exposure to isolate 1010 were compared with those produced by similar exposure to a different isolate, M. gallisepticum isolate 1150. Isolate 1010 caused a slightly higher incidence of sinusitis, but a much lower incidence of tracheitis than isolate 1150. Air sac lesions did not differ in incidence or severity. The differences observed indicate differences in tissue predilection of the isolates.

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8.
Histomonosis (blackhead or infectious enterohepatitis) is a disease of gallinaceous birds, especially of turkeys, and is caused by the protozoan Histomonas meleagridis. Since the ban of all chemoprophylactic and chemotherapeutic products against this disease in the European Union, this parasite causes a considerable amount of economical problems in the poultry industry. Research which could ultimately lead to the discovery of new drugs against this disease is thus highly necessary. Hence, in this study, the efficacy of paromomycin against histomonosis in turkeys was investigated.First, the prophylactic and therapeutic efficacy of this drug against H. meleagridis and its effect on the weight gain of turkeys was determined. Adding paromomycin to the feed (400 ppm as well as 200 ppm paromomycin) or to the drinking water (420 mg paromomycin per liter water, added prior to or on the day of challenge) significantly lowered the mortality rate and the caecal and liver lesion scores after an intracloacal infection compared to infected untreated birds. However, when paromomycin was administered to turkeys in the drinking water after the challenge, no significant differences in mortality or in lesion scores could be observed compared to the infected untreated control group. This demonstrates that paromomycin exerts a purely preventive action against histomonosis in turkeys. Additionally, the weight gain of the treated birds was positively influenced by the use of the drug, as the average weight gain of all treated groups (except for the group treated at the day of first mortality) was significantly higher than that of the untreated control group. Finally, the target site of paromomycin was detected in the SS rRNA gene of H. meleagridis. Consequently, the susceptibility to paromomycin can be correlated to the presence of the binding site of the drug at the 3′ end of the small subunit rRNA gene of the parasite. In conclusion, paromomycin can be used as a new prophylactic measure in the control of histomonosis in turkeys.  相似文献   

9.
The efficacy of three commercial Mycoplasma gallisepticum (MG) immunizing agents-a bacterin, a recombinant fowlpox-MG vaccine, and a live F-strain vaccine-was compared in specific-pathogen-free hens in egg production. Three groups of 25 chickens were vaccinated with one of the vaccines at 10 wk of age and 25 birds were not vaccinated. At 25 wk of age (and approximately 50% egg production), 20 birds from each of the three vaccinated groups and 15 nonvaccinated controls were challenged with virulent R-strain via aerosol; the birds were necropsied and evaluated at 10 days post-challenge. The MG bacterin and live F-strain vaccinations were both protective and resulted in significant differences in air sac lesions, tracheal lesions, and ovarian regression compared to the nonvaccinated controls and the recombinant fowlpox-MG vaccine (P < or = 0.05). The evaluation of ovarian regression is a useful method of testing the efficacy of MG vaccines in laying hens.  相似文献   

10.
The polymerase chain reaction (PCR) with primers complementary to the 16S rRNA genes was used to detect avian mycoplasmas. A primer pair designed for the detection of human and rodent mycoplasmal species was examined for its ability to detect the most important avian mycoplasmas. After testing the respective reference strains, we found that Mycoplasma iowae, Mycoplasma meleagridis and Mycoplasma synoviae could be detected by PCR with this primer pair, and distinction could be made among them by restriction fragment length polymorphism (RFLP) assay with two restriction enzymes (BamHI and RsaI). For the detection of Mycoplasma gallisepticum by PCR, we needed species-specific primers. The results of the PCR- and RFLP-based identification procedures of 17 different field isolates agreed with those obtained by conventional methods.  相似文献   

11.
ObjectiveTo test whether partial pressure of CO2 in expired gas (PēCO2) predicts the partial pressure of CO2 in arterial blood (PaCO2) in apneic chickens during air sac insufflation anesthesia at three different ventilation states. Secondary objective: To determine the PēCO2 at which apnea occurs during air sac insufflation anesthesia.Study designRandomized cross-over study.AnimalsTwenty-three healthy male white leghorn chickens.MethodsChickens were anesthetized via mask with isoflurane in oxygen and an air sac cannula was placed in the right abdominal air sac. Delivery of isoflurane in O2 was transferred from the mask to the air sac cannula. The birds were maintained at a surgical plane of anesthesia and apnea was induced by adjusting gas flow; the PēCO2 at apnea was recorded. The birds were then paralyzed and gas flow was adjusted to achieve three different PēCO2s in random order: 43 mmHg (5.6 kPa) [hypoventilation]; 33 mmHg (4.3 kPa) [normoventilation]; and 23 mmHg (3.0 kPa) [hyperventilation]. After maintaining the target expired isoflurane concentration (EIso; 1.85 or 1.90%) and PēCO2 for 15 minutes, arterial blood gas analysis was performed to determine the PaCO2. The chickens were euthanized at the end of the experiment.ResultsBased on Bland-Altman comparisons, PēCO2 was not strongly associated with PaCO2 during the three ventilation states. The PēCO2 at which apnea occurred varied {median (minimum, maximum): 35 (30, 48) mmHg [4.6 (3.9, 6.2) kPa]}.ConclusionsMeasured PēCO2 cannot be used in a simple linear fashion to predict PaCO2 in birds during air sac insufflation anesthesia. The PēCO2 at which apnea occurs during air sac insufflation anesthesia is not predictable.Clinical relevanceArterial blood gases should be used to monitor CO2 during air sac insufflation anesthesia to verify appropriate patient ventilation.  相似文献   

12.
One hundred budgerigars (Melopsittacus undulatus) were infected in the nares (0.02 ml/naris), eye (0.02 ml/eye), and throat (0.2 ml) with Mycoplasma gallisepticum (MG) R strain (3.175 x 10(7) colony-forming units/ml). Fifty birds were treated with sterile broth and served as the controls; 25 of those were exposed to an inhalant, and the others were not treated. Infected birds were divided into four groups; 1) no treatment, 2) penicillin in drinking water, 3) inhalant, 4) both penicillin and inhalant. At days 3, 7, 10, 14, and 21 postinfection (PI), birds were assessed for clinical signs of disease. Five birds in each group were euthanatized at each interval PI; quantitative cultures were performed on lavages from the nares and trachea and on throat swabs; tracheas and air sacs were examined histopathologically. No clinical signs, lesions, or cultural isolations occurred in any control birds. All infected birds developed clinical signs and lesions of the trachea and air sac, but none died. The most severe clinical signs were seen in birds that were infected with MG and received no other intervention or birds that received penicillin in conjunction with infection. Increased respiratory tract lesions were associated with penicillin treatment; aerosol therapy resulted in fewer lesions.  相似文献   

13.
Mycoplasma meleagridis appears to localize primarily in the respiratory tissues of the developing turkey embryo. This was determined by the daily collection throughout the incubation period of smears of embryonic tissues from 261 fertile turkey eggs. The tissues were examined using fluorescent antibody procedures and the earliest detection from positive tissues were: day 6, blastoderm (10%); day 8, sinus (44%) and peritoneum (55%); day 19, lung (11%) and trachea (44%); day 23, air sacs (62%).  相似文献   

14.
We evaluated the pathogenicity of three live Mycoplasma gallisepticum (MG) vaccine candidates by infection via aerosol of 3-wk-old chickens with log phase broth cultures (trial 1). Two of the candidates (K3020 and K4649A) colonized only 10% and 20% of the chickens, respectively, unlike K2101 (K-strain), which was reisolated from all of the vaccinated chickens tested. K-strain inoculation did not result in significant air sac or tracheal lesions in chickens at 10 and 39 days postinfection (P < or = 0.05). The efficacy of K-strain as a live vaccine was evaluated in trial 2, by challenge of vaccinated chickens with virulent R-strain via aerosol at 6 wk postvaccination. K-strain vaccination resulted in significant protection from air sac and tracheal lesions (P < or = 0.05). The K-strain was further investigated to evaluate transmissibility (trial 3), colonization and persistence of infection following aerosol administration (trial 4), genetic and phenotypic stability following back passage through chickens (trial 5), and vertical transmission (trial 6). The K-strain had a low rate of horizontal transmission; it remained primarily in the respiratory system of inoculated birds and persisted in the upper respiratory tract for the duration of the trial 4 (5 mo). There was no increase in virulence of K-strain when it was back passaged five times through chickens, and no vertical transmission of K-strain was detected. K-strain showed great potential as a safe and effective live MG vaccine.  相似文献   

15.
Two hundred turkey breeder hens and 24 viable toms of 30–35 weeks age of small white variety were distributed into two treatment groups having four replicates of 25 hens and three toms in each treatment. First four replicates were offered a turkey breeder diet (Diet A) (Nutrient requirements of poultry, 1994, National Academic Press, Washington, DC) and the rest four replicates were maintained on a higher plane of nutrition (Diet B) for 8‐week duration. After 6 weeks of experimental feeding, two replicates from each treatment groups were vaccinated with ND (R2B) vaccine. Yolk sac of embryo from birds fed Diet B had a significantly higher (p < .05) IgG, IgM level and HI titre (log 2) than those fed Diet A. HI titre values of embryonic yolk sac from the vaccinated birds fed Diet B were significantly higher (p < .05) than that of the control groups. In addition, HI titre values were significantly higher (p < .05) in the day‐old poults of the birds fed Diet B than that of those fed Diet A. There was significantly (p < .01) positive correlation between serum IgG and IgM of the breeder birds and day‐old chicks. Similarly, there was significantly (p < .05) positive correlation between yolk IgG and IgM after 1‐month experimental feeding and yolk sac IgG and IgM. Positive correlation (p < .05) also existed between yolk sac IgM and day‐old chick serum IgM. Furthermore, the HI titres of breeder birds' serum at 14 days post‐vaccination were positively correlated with their egg yolk after 10 and 15 days post‐vaccination, yolk sac and day‐old chicks. Thus, the study envisaged that a higher immunity in neonate poults from turkey breeders maintained on a higher plane of nutrition may be elicited as there was maternal transfer of antibodies from the serum of breeder birds to their offsprings through their yolk sac.  相似文献   

16.
Objective To investigate how different sampling techniques affect detection of DNA from feline herpes virus Type 1 (FHV-1), Chlamydophila felis and Mycoplasma felis and to study the correlation between positive test results and clinical signs in cats. Animals Fifty-one cats; 24 with ocular signs and 27 healthy control cats. Procedures Samples were collected from all cats using cotton swabs, conjunctival and corneal biopsies, and corneal scrapings. Samples were analyzed for presence of FHV-1, C. felis, M. felis, and feline DNA, defined by 28S rDNA, by using real-time PCR. Results In affected cats, FHV-1 was detected in only one cat; C. felis and M. felis were not detected in any affected cats. None of the three organisms was detected in any control cats. Feline DNA was demonstrated in all conjunctival samples, in 82% of corneal swabs, 92% of corneal scrapings, and 100% of keratectomy samples. Conclusions Because of the generally low detection rate for FHV-1, C. felis, and M. felis DNA in this study, differences regarding sampling technique could not be determined and correlation between positive test results and degree of clinical signs could not be made. Detection of feline DNA in most samples irrespective of sampling technique, suggests a low prevalence of FHV-1, C. felis and M. felis in this population of cats.  相似文献   

17.
AIM: To examine the infective dose, incubation period and disease progression of an isolate of Salmonella enterica serotype Typhimurium definitive type 160 (DT160) originating from a naturally-infected house sparrow (Passer domesticus) during an outbreak of the disease in New Zealand.

METHODS: Thirty-six house sparrows captured from the wild and free of Salmonella spp were divided into six groups of six birds, housed individually, and inoculated orally with phosphate buffered saline (PBS) or 101, 102, 103, 105, 2 × 108 colony forming units (cfu) of the outbreak strain of S. Typhimurium DT160. The birds were observed for 10 days for clinical signs and/or mortality, and faecal samples were collected to determine excretion of S. Typhimurium. The birds were eutha- nised 11 days post-inoculation (p.i.) and a wide range of tissue samples were collected for histopathological examination, and culture and typing of Salmonella spp. Macro-restriction profiling by pulsed-field gel electrophoresis (PFGE) using XbaI was performed for the epidemiological typing of S. Typhimurium DT160 isolates.

RESULTS: Mortality in house sparrows inoculated with S. Typhimurium DT160 was dose-dependent, and 2/6 birds inoculated with 105 cfu and all six birds inoculated with 2 × 108 cfu died during the study. Infected sparrows displayed few clinical signs, apart from diarrhoea and/or polyuria, fluffed plumage, and sitting on the floor of the cage. Faecal excretion of DT160 occurred briefly in two birds inoculated with 102 cfu and four birds inoculated with 103 cfu, on most days in five birds inoculated with 105 cfu, and continuously in six birds inoculated with 2 × 108 cfu. DT160 was isolated from the livers of three birds which received 103 cfu, five birds dosed with 105 cfu, and all six birds given 2 × 108 cfu. Following necropsy, histopathological lesions similar to those seen in the natural disease were observed in the liver or spleen of three birds which received 103 cfu, and all birds dosed with ≥105 cfu.

CONCLUSION: The results indicate that an isolate of S. Typhimurium DT60 originating from house sparrows in New Zealand is pathogenic to these birds and that the response is dose- dependent. The persistence and excretion of the pathogen may last for at least 10 days. This confirms that sparrows infected with DT160 could be a source of infection to humans and other in-contact animals.  相似文献   

18.
The live attenuated temperature-sensitive (ts+) Mycoplasma synovia (MS) strain, MS-H, is used as a vaccine in a number of countries to control virulent MS infection in commercial chicken flocks. Nine out of 50 isolates made from flocks vaccinated with MS-H were found to have lost the ts+ phenotype of the original vaccine strain. In order to examine the influence of the ts- phenotype on virulence of the isolates, four of the ts- isolates, the MS-H vaccine, and the vaccine parent strain 86079/7NS were administered by aerosol in conjunction with infectious bronchitis virus to 3-wk-old specific-pathogen-free chickens. The four ts- clones induced only minimal air sac lesions that were not different in severity from those caused by MS-H vaccine; however, the vaccine parent strain 86079/7NS caused air sac lesions that were significantly greater than those of MS-H and all ts- clones. The vaccine parent strain 86079/7NS and two of the ts- clones were recovered from the air sacs of the respectively infected chickens whereas the MS-H vaccine and two other ts- clones were not. Three of the ts- isolates caused increased tracheal mucosal thicknesses that were significantly greater than those from birds inoculated with MS-H, and one caused increased tracheal mucosal thicknesses that were significantly less than those from birds inoculated with 86079/7NS. In conclusion, unlike the MS-H vaccine, the MS-H ts- clones were associated with minor changes in tracheal mucosa; however, unlike the vaccine parent strain, they did not induce lesions in the air sacs. These results suggest that factors other than ts+ phenotype are involved in the attenuation of the MS-H vaccine.  相似文献   

19.
Heat productiorf and the importance of intact feathers for insulation were studied in jackass penguins Spheniscus demersus at various temperatures (5-25°C) by comparing their oxygen consumption in air and water with that of birds whose feather insulation was impaired when they were accidentally covered in partially weathered crude oil. Special attention was given to employing an experimental procedure that could relate oxygen consumption to level of activity. The mean ± SD metabolic rate recorded for normal inactive birds (188 ± 24 kJ kg-1 day-1) was the same in air and water but only 80% of the mass specific rates predicted for non-passerine birds. Wetting a bird increased the inactive rate in air 1,33 times while slow swimming in water above 10°C caused a 1,76-fold increase. At low air temperatures (5°C) postural changes and feather fluffing were associated with a very low rate of 122 ± 29 kJ kg-1 day-1, which we interpret as behavioural control of penguins over energy expenditure. Jackass penguins in sea water at 10°C and above were within their thermal neutral range thus indicating that the water phase of their life cycle is not energetically more expensive than the terrestrial phase. Activity c level of the birds was an important influence on oxygen consumption; we suggest it is the main reason for the variations in metabolic rates within closely related species "? reported in the literature.  相似文献   

20.
Specific pathogen free day-old chicks were inoculated with a virulent strain of Mycoplasma gallisepticum. Birds received either danofloxacin (50 ppm), tylosin (500 ppm) or no medication in the drinking water from 24 hours after infection for three days. The effects of medication on mortality, weight gain, serology, lesions and reisolation of M gallisepticum 21 days following infection were studied. Treatment with danofloxacin and tylosin significantly decreased mortality and increased weight gain compared with infected unmedicated birds. Twenty-one days after infection, M gallisepticum was isolated from 96 per cent of unmedicated birds compared with only 6 per cent of danofloxacin-treated and 40 per cent of tylosin-treated birds, and the percentage showing positive serological tests was reduced from 100 per cent of unmedicated birds to 0 per cent of danofloxacin-treated and 29 per cent of tylosin-treated birds. In both cases, the proportion of positive birds from the danofloxacin-treated group was significantly lower than that from the tylosin-treated group. The occurrence of air sac lesions was also significantly lower in danofloxacin-treated than in tylosin-treated birds.  相似文献   

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