Utility of strain typing of Propionibacterium acnes in central nervous system and prosthetic joint infections to differentiate contamination from infection: a retrospective cohort

Abstract

The study aimed to retrospectively assess if strain typing of Propionibacterium acnes could help to distinguish between infection and contamination in isolates recovered from the central nervous system (CNS) and prosthetic joints (PJs). This was a retrospective cohort of all Propionibacterium species isolates from the Barnes-Jewish Hospital (St Louis, MO, USA) clinical microbiology laboratory from 2011 to 2014. Available frozen isolates were recovered, and strain type (IA-1, IA-2, IB, II, III, or nontypeable class A or B) was determined via polymerase chain reaction (PCR)-based methods. For CNS isolates, P. acnes was considered pathogenic if treating physicians administered ≥7 days of directed antibiotic therapy against P. acnes. During the study period, Propionibacterium species was isolated from clinical cultures 411 times. 152 isolates were available for analysis. Of the 152 isolates, 140 were confirmed to be P. acnes, 61 of which were from the CNS (45 contaminants, 16 infections). Strain type IA-1 was more common (50.0%, 8 out of 16) among CNS infections than among contaminants (22.2%, 10 out of 45). For PJ isolates 61.3% (19 out of 31) met the criteria for infection. The predominant strain type for CNS infection was IA-1 and for PJ isolates, IB. Strain type IA-1 was isolated more often in patients with CNS infections, which may indicate a predilection of this strain type to cause CNS infection. Future research should prospectively evaluate strain typing as a means of assisting in the diagnosis of CNS infections and confirm our findings.

Cutibacterium acnes Isolates from Deep Tissue Specimens Retrieved during Revision Shoulder Arthroplasty: Similar Colony Morphology Does Not Indicate Clonality

“…However, the correlation between the hemolytic phenotype of Cutibacterium acnes and clinical outcome remains unclear (31,32). Similarly, several authors have attempted to correlate various subtypes of C. acnes with increased pathogenicity (13,16,(33)(34)(35)(36)(37)(38). While the correlation of certain subtypes with acnes vulgaris is clear (13,34), the correlation of subtypes with pathogenicity of infected implants is less so (16).…”

Over a Decade of recA and tly Gene Sequence Typing of the Skin Bacterium Propionibacterium acnes: What Have We Learnt?

“…The multiplex assay has now been described for the typing of P. acnes isolates from patients with acne [ 60 , 61 , 62 ], PMH [ 63 ], wound exudates and abscesses [ 62 ], microdiscectomy tissue [ 64 ], central nervous system and prosthetic joint infections [ 65 ], and other clinical conditions [ 60 ]. It has also been used for high throughput typing of P. acnes isolates from the pre-operative skin and surgical wound of patients undergoing spinal operations; this study was a large randomized controlled trial investigating the effects of povidone-iodine-alcohol (PVI) and chlorhexidine gluconate-alcohol on surgical wound contamination compared to PVI alone [ 66 ].…”

A Janus-Faced Bacterium: Host-Beneficial and -Detrimental Roles of Cutibacterium acnes

“…It is widely accepted that the number of culture-positive specimens per patient is a measure to evaluate the probability of infection (Bémer et al, 2008;Asseray et al, 2010;Frangiamore et al, 2015). In addition, the CFU count may be taken into consideration, as contaminants in most cases often result in very low CFU counts (Esteban et al, 2013;Burnham et al, 2017;Salar-Vidal et al, 2020). In fact, the use of implant sonication fluid alone could increase the rate of false positives if no CFU threshold is established (Grosso et al, 2018).…”