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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 between Normal and BCO samples using LEfSe analysis.Taxa abundance analysis determined 7 features were differentially abundant in BCO group (LDA score >2.4) and 21 features (LDA >2.4) in Normal cases. The genus Staphylococcus, which has been frequently isolated from BCO samples by previous researchers, is an abundant feature in BCO case.
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pone.0124403.g008: Comparison between Normal and BCO samples using LEfSe analysis.Taxa abundance analysis determined 7 features were differentially abundant in BCO group (LDA score >2.4) and 21 features (LDA >2.4) in Normal cases. The genus Staphylococcus, which has been frequently isolated from BCO samples by previous researchers, is an abundant feature in BCO case.

Mentions: We selected 28 macroscopically normal samples and 69 samples with BCO lesions for analysis, including 23 FHS, 14 FHN, 23 THN and 9 THNsc samples (S1 Table). Principal coordinate analysis (PCoA) shown in Fig 7 visually illustrates the differences between the bacterial communities in these bone samples. The communities in macroscopically normal bones are more tightly clustered as compared to the dispersed communities in bones with BCO lesions. On the other hand, the LEfSe analysis of the communities from Normal and BCO samples shows that there are 28 differentially abundant taxonomic clades with an LDA score higher than 2.4 (Fig 8). The most differentially abundant bacterial taxa in BCO samples belong to phyla: Proteobacteria. The genera overrepresented in BCO samples include Staphylococcus, Enterobacter, Serrotia and Nitrincola. Interestingly, the genus Staphylococcus was detected repeatedly in BCO samples in previous studies using culture-dependent methods [2,8,41,46,47]. The result from our parallel study based on culturing method also showed that in most cases BCO was attributable to Staphylococcus species (data not shown). The Staphylococcus genus includes at least 40 species. Of these, nine have two subspecies and one has three subspecies [48]. One of the species, Staphylococcus aureus, is the most prominent musculoskeletal pathogen of men and animals. It has a particular propensity to infect tissues of the musculoskeletal system, as evidenced by the fact that it is the single leading cause of osteomyelitis in humans [49]. According to ultrastructural studies, adhesion of S. aureus on damaged growth plate cartilage plays an important role for infection and proliferation within a thick adherent glycocalyx. This situation allows the presentation of a fibrous exopolysaccharide bacterial cell surface to the defense mechanisms of the host and provides a thick barrier to the penetration of antibiotics [50]. Our recent study based on culture independent method indicated that the genus Staphylococcus is present in the blood samples of BCO birds (unpublished data). This observation supports the hypothesis that Staphyloccous cells enter the blood stream through translocation from gastrointestinal tract and transmitted to bones hematogenously. However, with prevalent nature of Staphylococcus on chicken feather and poultry litter [51], it may be possible that Staphylococcus enters into the bones through external infection through necrotic lesions on the bone surface.


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 between Normal and BCO samples using LEfSe analysis.Taxa abundance analysis determined 7 features were differentially abundant in BCO group (LDA score >2.4) and 21 features (LDA >2.4) in Normal cases. The genus Staphylococcus, which has been frequently isolated from BCO samples by previous researchers, is an abundant feature in BCO case.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0124403.g008: Comparison between Normal and BCO samples using LEfSe analysis.Taxa abundance analysis determined 7 features were differentially abundant in BCO group (LDA score >2.4) and 21 features (LDA >2.4) in Normal cases. The genus Staphylococcus, which has been frequently isolated from BCO samples by previous researchers, is an abundant feature in BCO case.
Mentions: We selected 28 macroscopically normal samples and 69 samples with BCO lesions for analysis, including 23 FHS, 14 FHN, 23 THN and 9 THNsc samples (S1 Table). Principal coordinate analysis (PCoA) shown in Fig 7 visually illustrates the differences between the bacterial communities in these bone samples. The communities in macroscopically normal bones are more tightly clustered as compared to the dispersed communities in bones with BCO lesions. On the other hand, the LEfSe analysis of the communities from Normal and BCO samples shows that there are 28 differentially abundant taxonomic clades with an LDA score higher than 2.4 (Fig 8). The most differentially abundant bacterial taxa in BCO samples belong to phyla: Proteobacteria. The genera overrepresented in BCO samples include Staphylococcus, Enterobacter, Serrotia and Nitrincola. Interestingly, the genus Staphylococcus was detected repeatedly in BCO samples in previous studies using culture-dependent methods [2,8,41,46,47]. The result from our parallel study based on culturing method also showed that in most cases BCO was attributable to Staphylococcus species (data not shown). The Staphylococcus genus includes at least 40 species. Of these, nine have two subspecies and one has three subspecies [48]. One of the species, Staphylococcus aureus, is the most prominent musculoskeletal pathogen of men and animals. It has a particular propensity to infect tissues of the musculoskeletal system, as evidenced by the fact that it is the single leading cause of osteomyelitis in humans [49]. According to ultrastructural studies, adhesion of S. aureus on damaged growth plate cartilage plays an important role for infection and proliferation within a thick adherent glycocalyx. This situation allows the presentation of a fibrous exopolysaccharide bacterial cell surface to the defense mechanisms of the host and provides a thick barrier to the penetration of antibiotics [50]. Our recent study based on culture independent method indicated that the genus Staphylococcus is present in the blood samples of BCO birds (unpublished data). This observation supports the hypothesis that Staphyloccous cells enter the blood stream through translocation from gastrointestinal tract and transmitted to bones hematogenously. However, with prevalent nature of Staphylococcus on chicken feather and poultry litter [51], it may be possible that Staphylococcus enters into the bones through external infection through necrotic lesions on the bone surface.

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