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54. An AraC/XylS family transcriptional regulator homologue from Bacteroides fragilis is associated with cell survival following DNA damage

Author

Casanueva, Ana I, Paul, Lynthia, Patrick, Sheila, and Abratt, Valerie R

Subjects
Bacteroides fragilis, Transcriptional regulator, Metronidazole, Mitomycin C, DNA damage
Abstract

A putative transcriptional regulator of the AraC/XylS family was identified in a genomic genebank of Bacteroides fragilis Bf-1, which partially relieved the sensitivity of Escherichia coli DNA repair mutants to the DNA-damaging agents, metronidazole and mitomycin C. A homologue of this gene with the same phenotype was identified as BF638R3281 in B. fragilis 638R. Transcription of BF638R3281 was constitutive with respect to exposure to sublethal doses of metronidazole. BF638R3281 was interrupted by single cross-over gene-specific insertion mutation, and the gene disruption was confirmed by PCR and DNAsequencing analysis. The mutant grew more slowly than the wild type, and the mutation rendered B. fragilis more sensitive to metronidazole and mitomycin C. This indicates that the BF638R3281 gene product plays a role in the survival of B. fragilis following DNA damage by these agents.

Published
2008
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61. Propionibacterium acnes in human health and disease

Author

McDowell, Andrew, Patrick, Sheila, Eishi, Yoshinobu, Lambert, Peter, Eady, Anne, McDowell, Andrew, Patrick, Sheila, Eishi, Yoshinobu, Lambert, Peter, and Eady, Anne

Abstract

Editorial

Published
2013

62. Genotypic and antimicrobial characterisation of Propionibacterium acnes isolates from surgically excised lumbar disc herniations

Author

Rollason, Jess, McDowell, Andrew, Albert, Hanne B., Barnard, Emma, Worthington, Tony, Hilton, Anthony C., Vernallis, Ann, Patrick, Sheila, Elliott, Tom, Lambert, Peter, Rollason, Jess, McDowell, Andrew, Albert, Hanne B., Barnard, Emma, Worthington, Tony, Hilton, Anthony C., Vernallis, Ann, Patrick, Sheila, Elliott, Tom, and Lambert, Peter

Abstract

The anaerobic skin commensal Propionibacterium acnes is an underestimated cause of human infections and clinical conditions. Previous studies have suggested a role for the bacterium in lumbar disc herniation and infection. To further investigate this, five biopsy samples were surgically excised from each of 64 patients with lumbar disc herniation. P. acnes and other bacteria were detected by anaerobic culture, followed by biochemical and PCR-based identification. In total, 24/64 (38%) patients had evidence of P. acnes in their excised herniated disc tissue. Using recA and mAb typing methods, 52% of the isolates were type II (50% of culture-positive patients), while type IA strains accounted for 28% of isolates (42% patients). Type III (11% isolates; 21% patients) and type IB strains (9% isolates; 17% patients) were detected less frequently. The MIC values for all isolates were lowest for amoxicillin, ciprofloxacin, erythromycin, rifampicin, tetracycline, and vancomycin (≤1mg/L). The MIC for fusidic acid was 1-2 mg/L. The MIC for trimethoprim and gentamicin was 2 to ≥4 mg/L. The demonstration that type II and III strains, which are not frequently recovered from skin, predominated within our isolate collection (63%) suggests that the role of P. acnes in lumbar disc herniation should not be readily dismissed. © 2013 Jess Rollason et al.

Published
2013

75. A Biofilm Approach to Detect Bacteria on Removed Spinal Implants

Author

Sampedro, Marta Fernandez, primary, Huddleston, Paul M., additional, Piper, Kerryl E., additional, Karau, Melissa J., additional, Dekutoski, Mark B., additional, Yaszemski, Michael J., additional, Currier, Bradford L., additional, Mandrekar, Jayawant N., additional, Osmon, Douglas R., additional, McDowell, Andrew, additional, Patrick, Sheila, additional, Steckelberg, James M., additional, and Patel, Robin, additional

Published
2010
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78. Microbiologic Diagnosis of Prosthetic Shoulder Infection by Use of Implant Sonication

Author

Piper, Kerryl E., primary, Jacobson, Melissa J., additional, Cofield, Robert H., additional, Sperling, John W., additional, Sanchez-Sotelo, Joaquin, additional, Osmon, Douglas R., additional, McDowell, Andrew, additional, Patrick, Sheila, additional, Steckelberg, James M., additional, Mandrekar, Jayawant N., additional, Fernandez Sampedro, Marta, additional, and Patel, Robin, additional

Published
2009
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84. Identification of a Collagen Type I Adhesin of Bacteroides fragilis.

Author

Galvão, Bruna P. G. V., Weber, Brandon W., Rafudeen, Mohamed S., Ferreira, Eliane O., Patrick, Sheila, and Abratt, Valerie R.

Subjects
BACTEROIDES fragilis, PATHOGENIC bacteria, MEMBRANE proteins, EXTRACELLULAR matrix proteins, BACTERIAL colonies, BACTERIOLOGY
Abstract

Bacteroides fragilis is an opportunistic pathogen which can cause life threatening infections in humans and animals. The ability to adhere to components of the extracellular matrix, including collagen, is related to bacterial host colonisation. Collagen Far Western analysis of the B. fragilis outer membrane protein (OMP) fraction revealed the presence two collagen adhesin bands of ∼31 and ∼34 kDa. The collagen adhesins in the OMP fraction were separated and isolated by two-dimensional SDS-PAGE and also purified by collagen affinity chromatography. The collagen binding proteins isolated by both these independent methods were subjected to tandem mass spectroscopy for peptide identification and matched to a single hypothetical protein encoded by B. fragilis NCTC 9343 (BF0586), conserved in YCH46 (BF0662) and 638R (BF0633) and which is designated in this study as cbp1 (collagen binding protein). Functionality of the protein was confirmed by targeted insertional mutagenesis of the cbp1 gene in B. fragilis GSH18 which resulted in the specific loss of both the ∼31 kDa and the ∼34 kDa adhesin bands. Purified his-tagged Cbp1, expressed in a B. fragilis wild-type and a glycosylation deficient mutant, confirmed that the cbp1 gene encoded the observed collagen adhesin, and showed that the 34 kDa band represents a glycosylated version of the ∼31 kDa protein. Glycosylation did not appear to be required for binding collagen. This study is the first to report the presence of collagen type I adhesin proteins in B. fragilis and to functionally identify a gene encoding a collagen binding protein. [ABSTRACT FROM AUTHOR]

Published
2014
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92. The Opportunistic Pathogen Propionibacterium acnes: Insights into Typing, Human Disease, Clonal Diversification and CAMP Factor Evolution.

Author

McDowell, Andrew, Nagy, István, Magyari, Márta, Barnard, Emma, and Patrick, Sheila

Subjects
CUTIBACTERIUM acnes, BIODIVERSITY, POPULATION genetics, IMMUNOTHERAPY, NUCLEOTIDES, MICROBIAL virulence
Abstract

We previously described a Multilocus Sequence Typing (MLST) scheme based on eight genes that facilitates population genetic and evolutionary analysis of P. acnes. While MLST is a portable method for unambiguous typing of bacteria, it is expensive and labour intensive. Against this background, we now describe a refined version of this scheme based on two housekeeping (aroE; guaA) and two putative virulence (tly; camp2) genes (MLST4) that correctly predicted the phylogroup (IA1, IA2, IB, IC, II, III), clonal complex (CC) and sequence type (ST) (novel or described) status for 91% isolates (n = 372) via cross-referencing of the four gene allelic profiles to the full eight gene versions available in the MLST database (http://pubmlst.org/pacnes/). Even in the small number of cases where specific STs were not completely resolved, the MLST4 method still correctly determined phylogroup and CC membership. Examination of nucleotide changes within all the MLST loci provides evidence that point mutations generate new alleles approximately 1.5 times as frequently as recombination; although the latter still plays an important role in the bacterium's evolution. The secreted/cell-associated ‘virulence’ factors tly and camp2 show no clear evidence of episodic or pervasive positive selection and have diversified at a rate similar to housekeeping loci. The co-evolution of these genes with the core genome might also indicate a role in commensal/normal existence constraining their diversity and preventing their loss from the P. acnes population. The possibility that members of the expanded CAMP factor protein family, including camp2, may have been lost from other propionibacteria, but not P. acnes, would further argue for a possible role in niche/host adaption leading to their retention within the genome. These evolutionary insights may prove important for discussions surrounding camp2 as an immunotherapy target for acne, and the effect such treatments may have on commensal lineages. [ABSTRACT FROM AUTHOR]

Published
2013
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93. An AraC/XylS family transcriptional regulator homologue from Bacteroides fragilis is associated with cell survival following DNA damage.

Author

Casanueva, Ana I., Paul, Lynthia, Patrick, Sheila, and Abratt, Valerie R.

Subjects
DNA damage, BIOCHEMICAL genetics, BACTEROIDES, ENTEROBACTERIACEAE, ESCHERICHIA coli, GENOTYPE-environment interaction, METRONIDAZOLE, GENETIC mutation, PHENOTYPES
Abstract

A putative transcriptional regulator of the AraC/XylS family was identified in a genomic genebank of Bacteroides fragilis Bf-1, which partially relieved the sensitivity of Escherichia coli DNA repair mutants to the DNA-damaging agents, metronidazole and mitomycin C. A homologue of this gene with the same phenotype was identified as BF638R3281 in B. fragilis 638R. Transcription of BF638R3281 was constitutive with respect to exposure to sublethal doses of metronidazole. BF638R3281 was interrupted by single cross-over gene-specific insertion mutation, and the gene disruption was confirmed by PCR and DNA-sequencing analysis. The mutant grew more slowly than the wild type, and the mutation rendered B. fragilis more sensitive to metronidazole and mitomycin C. This indicates that the BF638R3281 gene product plays a role in the survival of B. fragilis following DNA damage by these agents. [ABSTRACT FROM AUTHOR]

Published
2008
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94. Propionibacterium acnesand Staphylococcus lugdunensisCause Pyogenic Osteomyelitis in an Intramedullary Nail Model in Rabbits

Author

Gahukamble, Abhay Deodas, McDowell, Andrew, Post, Virginia, Salavarrieta Varela, Julian, Rochford, Edward Thomas James, Richards, Robert Geoff, Patrick, Sheila, and Moriarty, Thomas Fintan

Abstract

ABSTRACTPropionibacterium acnesand coagulase-negative staphylococci (CoNS) are opportunistic pathogens implicated in prosthetic joint and fracture fixation device-related infections. The purpose of this study was to determine whether P. acnesand the CoNS species Staphylococcus lugdunensis, isolated from an “aseptically failed” prosthetic hip joint and a united intramedullary nail-fixed tibial fracture, respectively, could cause osteomyelitis in an established implant-related osteomyelitis model in rabbits in the absence of wear debris from the implant material. The histological features of P. acnesinfection in the in vivorabbit model were consistent with localized pyogenic osteomyelitis, and a biofilm was present on all explanted intramedullary (IM) nails. The animals displayed no outward signs of infection, such as swelling, lameness, weight loss, or elevated white blood cell count. In contrast, infection with S. lugdunensisresulted in histological features consistent with both pyogenic osteomyelitis and septic arthritis, and all S. lugdunensis-infected animals displayed weight loss and an elevated white blood cell count despite biofilm detection in only two out of six rabbits. The differences in the histological and bacteriological profiles of the two species in this rabbit model of infection are reflective of their different clinical presentations: low-grade infection in the case of P. acnesand acute infection for S. lugdunensis. These results are especially important in light of the growing recognition of chronic P. acnesbiofilm infections in prosthetic joint failure and nonunion of fracture fixations, which may be currently reported as “aseptic” failure.

Published
2014
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97. Propionibacterium acnesTypes I and II Represent Phylogenetically Distinct Groups

Author

McDowell, Andrew, Valanne, Susanna, Ramage, Gordon, Tunney, Michael M., Glenn, Josephine V., McLorinan, Gregory C., Bhatia, Ajay, Maisonneuve, Jean-Francois, Lodes, Michael, Persing, David H., and Patrick, Sheila

Abstract

ABSTRACTAlthough two phenotypes of the opportunistic pathogen Propionibacterium acnes(types I and II) have been described, epidemiological investigations of their roles in different infections have not been widely reported. Using immunofluorescence microscopy with monoclonal antibodies (MAbs) QUBPa1 and QUBPa2, specific for types I and II, respectively, we investigated the prevalences of the two types among 132 P. acnesisolates. Analysis of isolates from failed prosthetic hip implants (n= 40) revealed approximately equal numbers of type I and II organisms. Isolates from failed prosthetic hip-associated bone (n= 6) and tissue (n= 38) samples, as well as isolates from acne (n= 22), dental infections (n= 8), and skin removed during surgical incision (n= 18) were predominately of type I. A total of 11 (8%) isolates showed atypical MAb labeling and could not be conclusively identified. Phylogenetic analysis of P. acnesby nucleotide sequencing revealed the 16S rRNA gene to be highly conserved between types I and II. In contrast, sequence analysis of recAand a putative hemolysin gene (tly) revealed significantly greater type-specific polymorphisms that corresponded to phylogenetically distinct cluster groups. All 11 isolates with atypical MAb labeling were identified as type I by sequencing. Within the recAand tlyphylogenetic trees, nine of these isolates formed a cluster distinct from other type I organisms, suggesting a further phylogenetic subdivision within type I. Our study therefore demonstrates that the phenotypic differences between P. acnestypes I and II reflect deeper differences in their phylogeny. Furthermore, nucleotide sequencing provides an accurate method for identifying the type status of P. acnesisolates.

Published
2005
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100. Detection of Intrastrain Antigenic Variation of Bacteroides fragilisSurface Polysaccharides by Monoclonal Antibody Labelling

Author

Patrick, Sheila, Gilpin, Deirdre, and Stevenson, Leanne

Abstract

ABSTRACTBacteroides fragilisis a constituent of the normal resident microbiota of the human intestine and is the gram-negative obligately anaerobic bacterium most frequently isolated from clinical infection. Surface polysaccharides are implicated as potential virulence determinants. We present evidence of within strain immunochemical variation of surface polysaccharides in populations that are noncapsulate by light microscopy as determined by monoclonal antibody labelling. Expression of individual epitopes can be enriched from a population of an individual strain by use of immunomagnetic beads. Also, individual colonies in which either >94% or <7% of the bacteria carry an individual epitope retain this level of expression when subcultured into broth. In broth cultures where >94% of the bacteria carry a given epitope, there is no enrichment for other epitopes recognized by different polysaccharide-specific monoclonal antibodies. This intrastrain variation has important implications for the development of potential vaccines or immunodiagnostic tests.

Published
1999
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