Bacterial diversity in suspected prosthetic joint infections: an exploratory study using 16S rRNA gene analysis

Abstract

Formation of biofilm is a prominent feature of prosthetic joint infections (PJIs) and constitutes a challenge to current sampling procedures and culture practices. Molecular techniques have a potential for improving diagnosis of biofilm-adapted, slow-growing and non-culturable bacteria. In this exploratory study we investigated the bacterial diversity in specimens from 22 patients clinically suspected of having PJIs. Bacteriological cultures were performed according to standard practice. A total of 55 specimens from 25 procedures ('specimen sets') were submitted to broad range 16S rRNA gene PCR, cloning, sequencing and phylogenetic analysis. More than 40 bacterial taxa within six phyla were identified in 14 specimen sets originating from 11 patients. Direct observation of biofilm was made in selected specimens by fluorescence in situ hydridization. 16S rRNA gene analysis and bacteriological cultures were concordant for 15/25 specimen sets (60%; five positive, 10 negative); additional taxa were detected in four sets by gene analysis, and discrepant results were obtained for six sets, five of which were negative on culture. Polymicrobial communities were revealed in 9/14 sets by gene analysis and 1/10 sets by culture (P < 0.05). Although our study was not conclusive, these findings are consistent with a primary role of biofilm formation in PJIs.

Staphylococcus caprae bone and joint infections: a re-emerging infection?

“…To our knowledge, 31 S. caprae BJIs have been reported [3,11,[18][19][20][21][22][23][24][25][26][27] since the first recognition of the involvement of S. caprae in BJIs in 1997 [3,18]. The low incidence of reported S. caprae BJIs may be a result of the lack of rapid and accurate tools with which to identify S. caprae strains in the clinical microbiology laboratory [6,12,19,22,31,32].…”

“…However, only 31 cases of S. caprae BJI have been reported [3,11,[18][19][20][21][22][23][24][25][26][27]. Most S. caprae BJIs result from orthopedic device infections, including joint prosthesis infections (JPIs) in 21 cases [3,11,19,20,[23][24][25][26]28] and internal osteosynthesis device infections (I-ODIs) in two cases [19,21].…”

“…Many clinical S. caprae strains are incorrectly identified by automated phenotypic identification systems, including MicroScan (Dade Behring, West Sacramento, CA, USA), Vitek 2 (BioM erieux), and Crystal GP (Becton Dickinson, Sparks, MD, USA) [3,29,30]. Molecular techniques have improved the identification of S. caprae strains [6,12,19,22,31,32], and are useful when the standard culture tests give negative results [27]. An innovative tool for bacterial identification in the clinical microbiology laboratory is matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) [33], which has been recently used for the rapid and accurate identification of clinical S. caprae strains [30,34].…”

Future-Generation Sequencing and Clinical Microbiology

“…The discordance between molecular methods and culture-based methods creates challenges (sometimes one or the other is the more sensitive). [69][70][71] This issue might be conceivably resolved by using even more sensitive molecular methods, 72 but culture has a great advantage of auto-amplification when detecting culture-friendly organisms.…”

Counterinsurgency Doctrine Applied to Infectious Disease

“…Various technologies for community characterization are already available -particularly high-throughput sequencing (Xu et al 2012), but also multiplexed PCR ( novo. They can provide information about structure, biochemistry or genetics, but this information does not directly translate into ecology, and simple technological fixes for this gap do not exist.…”