Are Cutibacterium recovered from revision arthroplasty different from those found on normal skin?

Cutibacterium Recovered from Deep Specimens at the Time of Revision Shoulder Arthroplasty Samples Have Increased Biofilm Forming Capacity and Hemolytic Activity Compared to Cutibacterium Skin Isolates from Normal Subjects

It is apparent that Cutibacterium have two faces: benign commensal and pathogenic in shoulder periprosthetic infections (see this link).  

To explore this duality, these authors sought to compare the prevalence of Cutibacterium subtypes, biofilm formation and hemolytic activity between Cutibacterium recovered from 42 deep specimens obtained at the time of surgical revision for failed shoulder arthroplasty and Cutibacterium recovered from 43 samples of the skin from normal subjects.

Biofilm forming capacity and hemolytic activity were significantly higher in the tissue and explant samples compared to the control skin samples.  

Samples with hemolytic activity had significantly higher biofilm forming capacity compared to samples without hemolytic activity (0.27 ± 0.29 vs. 0.12 ± 0.15, p=0.015).

While there were significant differences in genetic subtypes between samples from revised shoulders and normal skin

the difference in biofilm forming capacity and hemolytic activity between genetic subtypes of Cutibacterium was not statistically significant in this study

Comment: These data add support for the view that Cutibacterium harvested from deep tissues are significantly different from those recovered from normal skin with respect to both genetic subtypes and phenotype (hemolysis and biofilm formation).

The lack of statistically significant correlation between Cutibacterium phenotypes and genetic subtype suggests that the observed differences in hemolytic activity and biofilm formation may relate at least in part to gene expression rather than to genetics. 

Follow on twitter: https://twitter.com/shoulderarth

Follow on facebook: https://www.facebook.com/frederick.matsen

Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

How you can support research in shoulder surgery Click on this link.

Here are some videos that are of shoulder interest

Shoulder arthritis - what you need to know (see this link)

The smooth and move for irreparable cuff tears (see this link)

The total shoulder arthroplasty (see this link).

The ream and run technique is shown in this link.

The cuff tear arthropathy arthroplasty (see this link).

The reverse total shoulder arthroplasty (see this link).

Shoulder rehabilitation exercises (see this link).

All Propionibacteria are not the same - some are hemolytic and some are drug resistant

Hemolysis Is a Diagnostic Adjuvant for Propionibacterium acnes Orthopaedic Shoulder Infections

These authors explored the pathogenicity of hemolytic and nonhemolytic phenotypes of Propionibacterium acnes (P acnes) isolates from shoulder joint aspiration fluid and/or intraoperative tissues.

Hemolysis demonstrated 100% specificity with a positive predictive value of 100% and 80% sensitivity with a negative predictive value of 73% for determining definite and probable infections. 

100% of the patients in the hemolytic group and only 27% of patients in the nonhemolytic group were classified as infected.

Inflammatory markers were markedly higher in the hemolytic group.

Clindamycin resistance was found in 31% of the hemolytic strains, whereas no antibiotic resistance was observed in the nonhemolytic group. 

Time from index surgery to the initial treatment or revision procedure was almost twice as long in the nonhemolytic group. A substantial percentage of patients in the hemolytic group (44%) compared with the nonhemolytic group (0%) failed initial treatment requiring a revision procedure for persistent infection.

These authors concluded that hemolytic strains of P acnes exhibit enhanced pathogenicity to their host by eliciting a more prominent systemic inflammatory response, increased antibiotic resistance, and a more challenging clinical course. 

Comment: This article needs to be considered along with another recent publication:

Hemolytic strains of Propionibacterium acnes do not demonstrate greater pathogenicity in periprosthetic shoulder infections

Certain strains of Propionibacterium result in hemolysis when streaked on a blood agar plate as shown in "A" below in contrast to "B" which does not show hemolysis.

These authors studied 39 patients with at least 1 positive culture for P acnes at the time of revision shoulder arthroplasty who also had testing of the Propionibacterium for hemolysis. 20 of the isolated strains showed hemolytic activity and 19 did not. 

In this study the presence of hemolysis was not significantly associated with greater clinical evidence of infection. The hemolytic and nonhemolytic groups showed no difference regarding preoperative serum erythrocyte sedimentation rate and/or C-reactive protein level (P = .70), number of positive cultures (P = .395), time to positive culture (P = .302), and presence of positive frozen section findings (P = .501). Postoperatively, clindamycin resistance, shoulder function, and the rate of reoperation were not significantly different between the hemolytic and nonhemolytic groups.

These authors point out that a prior study by Nodzo et al in 2014 demonstrated significantly elevated
CRP levels in hemolysis-positive patients.  More recently, this group expanded their analysis with 31 patients evaluated for hemolysis. In that study by Boyle et al 2016 showed significantly elevated ESR and CRP levels, as well as a significantly greater percentage (31% vs 0%) of antibiotic resistance, in cases with hemolysis-positive Propionibacterium cultures.

Comment: At this point it is difficult to be sure whether or not hemolytic strains are more virulent than non-hemolytic strains of Propionibacterium.  It is clear, however, that all strains of Propionibacterium are not the same as revealed by the hemolytic phenotype as well as the Clindamycin-resistant phenotype. How these differences affect the diagnosis, clinical course and management of Propionibacterium in revision arthroplasty remains to be seen.

Interested readers may be interested in these two articles:

Genetic profiles of Propionibacterium acnes and identification of a unique transposon with novel insertion sequences in sarcoid and non-sarcoid isolates  which identified two hemolytic-associated genes (camp 5 and tly) and

Enzymatic and hemolytic properties of Propionibacterium acnes and related bacteria.

===

We have a new set of shoulder youtubes about the shoulder, check them out at this link.

Be sure to visit "Ream and Run - the state of the art" regarding this radically conservative approach to shoulder arthritis at this link and this link

Use the "Search" box to the right to find other topics of interest to you.

How you can support progress in shoulder surgery

You may be interested in some of our most visited web pages  arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

Propionibacterium - are hemolytic strains more virulent?

Hemolytic strains of Propionibacterium acnes do not demonstrate greater pathogenicity in periprosthetic shoulder infections

Certain strains of Propionibacterium result in hemolysis when streaked on a blood agar plate as shown in "A" below in contrast to "B" which does not show hemolysis.

Some authors have suggested that hemolysis is associated with increased pathogenicity of certain strains of Propionibacterium

These authors studied 39 patients with at least 1 positive culture for P acnes at the time of revision shoulder arthroplasty who also had testing of the Propionibacterium for hemolysis. 20 of the isolated strains showed hemolytic activity and 19 did not. 

The presence of hemolysis was not significantly associated with greater clinical evidence of infection. The hemolytic and nonhemolytic groups showed no difference regarding preoperative serum erythrocyte sedimentation rate and/or C-reactive protein level (P = .70), number of positive cultures (P = .395), time to positive culture (P = .302), and presence of positive frozen section findings (P = .501). Postoperatively, clindamycin resistance, shoulder function, and the rate of reoperation were not significantly different between the hemolytic and nonhemolytic groups.

These authors point out that a prior study by Nodzo et al in 2014 demonstrated significantly elevated
CRP levels in hemolysis-positive patients.  More recently, this group expanded their analysis with 31 patients evaluated for hemolysis. In that study by Boyle et al 2016 showed significantly elevated ESR and CRP levels, as well as a significantly greater percentage (31% vs 0%) of antibiotic resistance, in cases with hemolysis-positive Propionibacterium cultures.

Comment: At this point it is difficult to be sure whether or not hemolytic strains are more virulent than non-hemolytic strains of Propionibacterium.  It is clear, however, that all strains of Propionibacterium are not the same as revealed by the hemolytic phenotype as well as the Clindamycin-resistant phenotype. How these differences affect the diagnosis, clinical course and management of Propionibacterium in revision arthroplasty remains to be seen.

Interested readers may be interested in these two articles:

Genetic profiles of Propionibacterium acnes and identification of a unique transposon with novel insertion sequences in sarcoid and non-sarcoid isolates  which identified two hemolytic-associated genes (camp 5 and tly) and

Enzymatic and hemolytic properties of Propionibacterium acnes and related bacteria.

 =====
The reader may also be interested in these posts:

Healing through joint replacement

Supporting progress in shoulder surgery

Consultation for those who live a distance away from Seattle.

Click here to see the new Shoulder Arthritis Book.

Click here to see the new Rotator Cuff Book

Information about shoulder exercises can be found at this link.

Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

See from which cities our patients come.

See the countries from which our readers come on this post.

Propionibacterium - resistance to clindamycin

Propionibacterium acnes Susceptibility and Correlation with Hemolytic Phenotype

These authors tested the antibiotic susceptibility and hemolytic activity of 106 P. acnes strains from sterile body sites (i.e. not from infections) collected at their medical center.

14 were hemolytic and 83 were not.
 

 They found that 9% of the strains were resistant to clindamycin and that there was an association between those phenotypes that were hemolytic on Brucella Blood Agar and clindamycin resistance.

Comment: This study again points out that all Propionibacterium are not the same. Some strains are hemolytic and some are clindamycin resistant. In shoulder arthroplasty prophylaxis and in the treatment of shoulder arthroplasty infections, antibiotics other than clindamycin may be preferable.

This article should be contrasted with

Hemolytic strains of Propionibacterium acnes do not demonstrate greater pathogenicity in periprosthetic shoulder infections

in which patients with at least 1 positive culture growth for P acnes at the time of revision surgery were identified with P acnes isolates available for hemolysis testing. Patients were grouped into
those with P acnes isolates positive (n = 20) and negative (n = 19) for hemolysis. The groups were retrospectively compared based on objective perioperative findings around the time of revision surgery and the postoperative clinical course, including the need for revision surgery. All cases were classified into categories of infection (definite infection, probable infection, and probable contaminant) based on objective perioperative criteria.

In this study the presence of hemolysis was not significantly associated with an increased likelihood of infection (P = .968). Hemolysis demonstrated a 75% sensitivity and 26% specificity for determining infection (definite infection and probable infection categories). The hemolytic and nonhemolytic groups showed no difference regarding preoperative serum erythrocyte sedimentation rate and/or C-reactive protein level (P = .70), number of positive cultures (P = .395), time to positive culture (P = .302), and presence of positive frozen section findings (P = .501). Postoperatively, clindamycin resistance, shoulder function, and the rate of reoperation were not significantly different between the hemolytic and nonhemolytic groups.

These authors concluded that presence of hemolysis was not associated with increased pathogenicity in patients with P acnes–positive cultures following revision shoulder arthroplasty, when assessed by objective perioperative criteria and the postoperative clinical course.

=====
The reader may also be interested in these posts:

Healing through joint replacement

Supporting progress in shoulder surgery

Consultation for those who live a distance away from Seattle.

Click here to see the new Shoulder Arthritis Book.

Click here to see the new Rotator Cuff Book

Information about shoulder exercises can be found at this link.

Use the "Search" box to the right to find other topics of interest to you.

You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and run, reverse total shoulder, CTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'

See from which cities our patients come.

See the countries from which our readers come on this post.