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Molecular survey of bacterial communities associated with bacterial chondronecrosis with osteomyelitis (BCO) in broilers.

Jiang T, Mandal RK, Wideman RF, Khatiwara A, Pevzner I, Min Kwon Y - PLoS ONE (2015)

Bottom Line: Relatively little is known about the microbial communities associated with BCO.Rarefaction analysis demonstrated the general tendency that increased severities of BCO lesions were associated with reduced species diversity in both femoral and tibial samples when compared to macroscopically normal samples.These observations suggest that certain bacterial subgroups are preferentially selected in association with the development of BCO lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, United States of America.

ABSTRACT
Bacterial chondronecrosis with osteomyelitis (BCO) is recognized as an important cause of lameness in commercial broiler chickens (meat-type chickens). Relatively little is known about the microbial communities associated with BCO. This study was conducted to increase our understanding of the microbial factors associated with BCO using a culture-independent approach. Using Illumina sequencing of the hyper-variable region V6 in the 16S rRNA gene, we characterized the bacterial communities in 97 femoral or tibial heads from normal and lame broilers carefully selected to represent diverse variations in age, line, lesion type, floor type, clinical status and bone type. Our in-depth survey based on 14 million assembled sequence reads revealed that complex bacterial communities exist in all samples, including macroscopically normal bones from clinically healthy birds. Overall, Proteobacteria (mean 90.9%) comprised the most common phylum, followed by Firmicutes (6.1%) and Actinobacteria (2.6%), accounting for more than 99% of all reads. Statistical analyses demonstrated that there are differences in bacterial communities in different types of bones (femur vs. tibia), lesion types (macroscopically normal femora or tibiae vs. those with pathognomonic BCO lesions), and among individual birds. This analysis also showed that BCO samples overrepresented genera Staphylococcus, whose species have been frequently isolated in BCO samples in previous studies. Rarefaction analysis demonstrated the general tendency that increased severities of BCO lesions were associated with reduced species diversity in both femoral and tibial samples when compared to macroscopically normal samples. These observations suggest that certain bacterial subgroups are preferentially selected in association with the development of BCO lesions. Understanding the microbial species associated with BCO will identify opportunities for understanding and modulating the pathogenesis of this form of lameness in broilers.

No MeSH data available.


Related in: MedlinePlus

Comparison of the α-diversity in different groups of bone samples.Diversity levels were estimated using Chao1 index with rarefied 180 V6 rRNA reads per sample. Means with the same letters in red color within the same row are not different significantly (p>0.05). Means with the same letters in blue within the same column are not different significantly (p>0.05).
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pone.0124403.g005: Comparison of the α-diversity in different groups of bone samples.Diversity levels were estimated using Chao1 index with rarefied 180 V6 rRNA reads per sample. Means with the same letters in red color within the same row are not different significantly (p>0.05). Means with the same letters in blue within the same column are not different significantly (p>0.05).

Mentions: Interestingly, there was a general trend that the diversity within a bacterial community (α diversity) was highest during the first week, and decreased with aging (Fig 5). The opposite trend was reported for chicken cecal samples [36]. These observations suggest selection processes are operating in favor of certain bacterial subgroups in bones in association with aging. The pathogenesis of progressive BCO lesion development, including increases in the size and caseous nature of the most severe bacterial sequestrae, undoubtedly would affect the diversity of the bacterial community, and would be expected to result in decreased diversity with aging. Indeed, a time-course analysis of lesion development demonstrates progressively greater incidences of the early macroscopic FHS and THN lesions over the seven week course of the present experiment. Age-related increases in incidences of the most severe lesions, FHN and THNsc, were less dramatic, likely because birds with BCO lesions in these categories rapidly succumbed to clinical lameness. In addition, the bones with more severe macroscopical lesions were generally associated with reduced diversity of the bacterial communities (Fig 5).


Molecular survey of bacterial communities associated with bacterial chondronecrosis with osteomyelitis (BCO) in broilers.

Jiang T, Mandal RK, Wideman RF, Khatiwara A, Pevzner I, Min Kwon Y - PLoS ONE (2015)

Comparison of the α-diversity in different groups of bone samples.Diversity levels were estimated using Chao1 index with rarefied 180 V6 rRNA reads per sample. Means with the same letters in red color within the same row are not different significantly (p>0.05). Means with the same letters in blue within the same column are not different significantly (p>0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400152&req=5

pone.0124403.g005: Comparison of the α-diversity in different groups of bone samples.Diversity levels were estimated using Chao1 index with rarefied 180 V6 rRNA reads per sample. Means with the same letters in red color within the same row are not different significantly (p>0.05). Means with the same letters in blue within the same column are not different significantly (p>0.05).
Mentions: Interestingly, there was a general trend that the diversity within a bacterial community (α diversity) was highest during the first week, and decreased with aging (Fig 5). The opposite trend was reported for chicken cecal samples [36]. These observations suggest selection processes are operating in favor of certain bacterial subgroups in bones in association with aging. The pathogenesis of progressive BCO lesion development, including increases in the size and caseous nature of the most severe bacterial sequestrae, undoubtedly would affect the diversity of the bacterial community, and would be expected to result in decreased diversity with aging. Indeed, a time-course analysis of lesion development demonstrates progressively greater incidences of the early macroscopic FHS and THN lesions over the seven week course of the present experiment. Age-related increases in incidences of the most severe lesions, FHN and THNsc, were less dramatic, likely because birds with BCO lesions in these categories rapidly succumbed to clinical lameness. In addition, the bones with more severe macroscopical lesions were generally associated with reduced diversity of the bacterial communities (Fig 5).

Bottom Line: Relatively little is known about the microbial communities associated with BCO.Rarefaction analysis demonstrated the general tendency that increased severities of BCO lesions were associated with reduced species diversity in both femoral and tibial samples when compared to macroscopically normal samples.These observations suggest that certain bacterial subgroups are preferentially selected in association with the development of BCO lesions.

View Article: PubMed Central - PubMed

Affiliation: Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, United States of America.

ABSTRACT
Bacterial chondronecrosis with osteomyelitis (BCO) is recognized as an important cause of lameness in commercial broiler chickens (meat-type chickens). Relatively little is known about the microbial communities associated with BCO. This study was conducted to increase our understanding of the microbial factors associated with BCO using a culture-independent approach. Using Illumina sequencing of the hyper-variable region V6 in the 16S rRNA gene, we characterized the bacterial communities in 97 femoral or tibial heads from normal and lame broilers carefully selected to represent diverse variations in age, line, lesion type, floor type, clinical status and bone type. Our in-depth survey based on 14 million assembled sequence reads revealed that complex bacterial communities exist in all samples, including macroscopically normal bones from clinically healthy birds. Overall, Proteobacteria (mean 90.9%) comprised the most common phylum, followed by Firmicutes (6.1%) and Actinobacteria (2.6%), accounting for more than 99% of all reads. Statistical analyses demonstrated that there are differences in bacterial communities in different types of bones (femur vs. tibia), lesion types (macroscopically normal femora or tibiae vs. those with pathognomonic BCO lesions), and among individual birds. This analysis also showed that BCO samples overrepresented genera Staphylococcus, whose species have been frequently isolated in BCO samples in previous studies. Rarefaction analysis demonstrated the general tendency that increased severities of BCO lesions were associated with reduced species diversity in both femoral and tibial samples when compared to macroscopically normal samples. These observations suggest that certain bacterial subgroups are preferentially selected in association with the development of BCO lesions. Understanding the microbial species associated with BCO will identify opportunities for understanding and modulating the pathogenesis of this form of lameness in broilers.

No MeSH data available.


Related in: MedlinePlus