Mycoplasma synoviae(M.synoviae)infections have become an increasingly serious concern in China because they cause huge economic losses to the poultry industry.Antibiotic treatment is one of control strategies that can...Mycoplasma synoviae(M.synoviae)infections have become an increasingly serious concern in China because they cause huge economic losses to the poultry industry.Antibiotic treatment is one of control strategies that can be used to contain clinical outbreaks in M.synoviae-free flocks,especially because the bacteria can be transmitted through eggs.To understand M.synoviae infection status in farms of central China and the antibiotic susceptibility of the circulating strains in vivo and in vitro,485 samples were collected from five provinces from 2019 to 2021.Fifty-two strains were isolated and identified.Determination of the minimum inhibitory concentration(MIC)of eight antibiotics(tylvalosin,tiamulin,tilmicosin,lincomycin,enrofloxacin,chlortetracycline,doxycycline and tylosin)for isolates showed that tylvalosin,doxycycline and tiamulin were effective against 52 clinical isolates(MIC values≤0.0625-0.25μg/mL,≤0.0625-1μg/mL,and 0.25-2μg/mL,respectively).Tilmicosin,enrofloxacin and lincomycin had high MICo values(>32μg/mL).An artificial M.synoviae infection model was established in chickens for evaluation of the short-term therapeutic effect of these antibiotics.After 5 days of medication,doxycycline(200 mg/L)showed a superior ability to inhibit M.synoviae compared with other groups,as did tylvalosin(200 mg/L).Furthermore,the therapeutic efficacy of tylvalosin(0.4μg/mL)on intra-embryo-injected M.synoviae was higher than that of tiamulin at the same dose.A combination of MiC values determined in vitro and therapeutic effects observed in vivo revealed that tylvalosin and doxycycline had the best therapeutic effects.Tylvalosin also showed better inhibitory effects on the vertical transmis-sion of M.synoviae than tiamulin.展开更多
This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders w...This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders were vaccinated with the ts<sup>+</sup> MS-H strain. At 9 weeks of age, an outbreak of infectious synovitis (IS) was detected in the progeny. Tracheal swab samples were collected from breeders at 24, 39, 48, and 70 weeks of age. At 9 weeks, pullets swab from the elbow joints were collected. RAPD was performed on the isolates at 39.5°C, and the same ts<sup>-</sup> MS-H strains were identified in the breeder hens and their progeny. Tracheal swabs from breeder hens were negative to MS isolation at 37°C and 39.5°C at 24- and 39-weeks. MS isolation was recovered from tracheal swabs from 9/10 and 10/10 breeders at 48- and 70- week. At 9 weeks of age in the progeny, MS was isolated from tracheal swabs of 10/10 from non-IS pullets. MS was isolated from 9/10 joints samples. The isolates from breeder hens and their progeny showed non-significant differences in five antimycoplasmic MIC100 values;otherwise, enrofloxacin presented a significant difference in MIC100 value (p < 0.05). This investigation demonstrated the reversal of the thermosensitivity, pathogenicity, and vertical transmission of the MS-H strain. Consequently, it is crucial to contemplate the danger of reversing pathogenicity and transmission to progeny when applying the MS-H vaccine strain.展开更多
Mycoplasma synoviae （MS） is an economically important pathogenic agent of chickens, causing air sacculitis and synovitis. The diagnosis and monitoring of M. synoviae infection is usually made using serological assay...Mycoplasma synoviae （MS） is an economically important pathogenic agent of chickens, causing air sacculitis and synovitis. The diagnosis and monitoring of M. synoviae infection is usually made using serological assays, while confirmative diagnosis is made by isolation and identifcation of the organism, because of the cross reaction between M. gallisepticum and M. synoviae. This study was conducted from 2011 to 2013 during which l l broiler breeder flocks were sampled. These farms were located in all regions of morocco, The sampling was conducted as follows： Farms were visited on day one old chicks ＂day of importation from Europe＂. 20 to 60 ＂chicks＂ were randomly sampled. At the age of 8, 16, 32 and 56 weeks, 60 blood samples and 60 tracheal swabs were collected at each sampling. The serological screening was performed using Rapid Slide Agglutination （RSA） according the OIE protocol and Indirect EL1SA （IDEXX） according the manufacturer＇s instructions. The molecular diagnosis was performed using a commercial kit of a duplex real time PCR （Life Biotechnology）. The results revealed that one day old chicks were negative to MS by RSA and PCR, however they have a variable stock of maternal antibodies （Ig-Y） detected by iELISA. The seroprevalence found by RSA is variable and increase with the age （Sth week： 55%, 16th week： 91%, 32tb and 56th week： 100%）, the same profile was traced by PCR （Sth week： 36%, 16th week： 64%, 32th week： 82%, 56th week： 100%）, however, all farms were positive by iELISA, from the first day to 56th weeks. These results show that MS infections are very frequent and very widespread among poultry breeder flocks, and showed a perfect agreement between serological tests and Real time PCR starting from 32th week of age.展开更多
基金This work was supported by the Key Research and Development Project of Hubei Province(Grant No.2021BBA252)the Earmarked Fund for China Agriculture Research System(CARS-41).
文摘Mycoplasma synoviae(M.synoviae)infections have become an increasingly serious concern in China because they cause huge economic losses to the poultry industry.Antibiotic treatment is one of control strategies that can be used to contain clinical outbreaks in M.synoviae-free flocks,especially because the bacteria can be transmitted through eggs.To understand M.synoviae infection status in farms of central China and the antibiotic susceptibility of the circulating strains in vivo and in vitro,485 samples were collected from five provinces from 2019 to 2021.Fifty-two strains were isolated and identified.Determination of the minimum inhibitory concentration(MIC)of eight antibiotics(tylvalosin,tiamulin,tilmicosin,lincomycin,enrofloxacin,chlortetracycline,doxycycline and tylosin)for isolates showed that tylvalosin,doxycycline and tiamulin were effective against 52 clinical isolates(MIC values≤0.0625-0.25μg/mL,≤0.0625-1μg/mL,and 0.25-2μg/mL,respectively).Tilmicosin,enrofloxacin and lincomycin had high MICo values(>32μg/mL).An artificial M.synoviae infection model was established in chickens for evaluation of the short-term therapeutic effect of these antibiotics.After 5 days of medication,doxycycline(200 mg/L)showed a superior ability to inhibit M.synoviae compared with other groups,as did tylvalosin(200 mg/L).Furthermore,the therapeutic efficacy of tylvalosin(0.4μg/mL)on intra-embryo-injected M.synoviae was higher than that of tiamulin at the same dose.A combination of MiC values determined in vitro and therapeutic effects observed in vivo revealed that tylvalosin and doxycycline had the best therapeutic effects.Tylvalosin also showed better inhibitory effects on the vertical transmis-sion of M.synoviae than tiamulin.
文摘This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders were vaccinated with the ts<sup>+</sup> MS-H strain. At 9 weeks of age, an outbreak of infectious synovitis (IS) was detected in the progeny. Tracheal swab samples were collected from breeders at 24, 39, 48, and 70 weeks of age. At 9 weeks, pullets swab from the elbow joints were collected. RAPD was performed on the isolates at 39.5°C, and the same ts<sup>-</sup> MS-H strains were identified in the breeder hens and their progeny. Tracheal swabs from breeder hens were negative to MS isolation at 37°C and 39.5°C at 24- and 39-weeks. MS isolation was recovered from tracheal swabs from 9/10 and 10/10 breeders at 48- and 70- week. At 9 weeks of age in the progeny, MS was isolated from tracheal swabs of 10/10 from non-IS pullets. MS was isolated from 9/10 joints samples. The isolates from breeder hens and their progeny showed non-significant differences in five antimycoplasmic MIC100 values;otherwise, enrofloxacin presented a significant difference in MIC100 value (p < 0.05). This investigation demonstrated the reversal of the thermosensitivity, pathogenicity, and vertical transmission of the MS-H strain. Consequently, it is crucial to contemplate the danger of reversing pathogenicity and transmission to progeny when applying the MS-H vaccine strain.
文摘Mycoplasma synoviae （MS） is an economically important pathogenic agent of chickens, causing air sacculitis and synovitis. The diagnosis and monitoring of M. synoviae infection is usually made using serological assays, while confirmative diagnosis is made by isolation and identifcation of the organism, because of the cross reaction between M. gallisepticum and M. synoviae. This study was conducted from 2011 to 2013 during which l l broiler breeder flocks were sampled. These farms were located in all regions of morocco, The sampling was conducted as follows： Farms were visited on day one old chicks ＂day of importation from Europe＂. 20 to 60 ＂chicks＂ were randomly sampled. At the age of 8, 16, 32 and 56 weeks, 60 blood samples and 60 tracheal swabs were collected at each sampling. The serological screening was performed using Rapid Slide Agglutination （RSA） according the OIE protocol and Indirect EL1SA （IDEXX） according the manufacturer＇s instructions. The molecular diagnosis was performed using a commercial kit of a duplex real time PCR （Life Biotechnology）. The results revealed that one day old chicks were negative to MS by RSA and PCR, however they have a variable stock of maternal antibodies （Ig-Y） detected by iELISA. The seroprevalence found by RSA is variable and increase with the age （Sth week： 55%, 16th week： 91%, 32tb and 56th week： 100%）, the same profile was traced by PCR （Sth week： 36%, 16th week： 64%, 32th week： 82%, 56th week： 100%）, however, all farms were positive by iELISA, from the first day to 56th weeks. These results show that MS infections are very frequent and very widespread among poultry breeder flocks, and showed a perfect agreement between serological tests and Real time PCR starting from 32th week of age.
