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Paper of the week: Polymerase chain reaction assay using the restriction fragment length polymorphism technique in the detection of prosthetic joint infections: A Multi-Centered Study

Paper of the week: Polymerase chain reaction assay using the restriction fragment length polymorphism technique in the detection of prosthetic joint infections: A Multi-Centered Study. Moshirabadi A, Razi M, Arasteh P, Sarzaeem MM, Ghaffari S, Aminiafshar S, Hosseinian Khosroshahy K, Sheikholeslami FM. J Arthroplasty. 2018 Oct 25. pii: S0883-5403(18)31057-X. doi: 10.1016/j.arth.2018.10.017. [Epub ahead of print].

Summary and Editorial by Sreeram Penna

The main aim of this prospective study was to assess the diagnostic accuracy of polymerase chain reaction (PCR) using RFLP (restriction fragment length polymorphism) method. Researchers also obtained bacterial cultures at the same time. The study assessed 76 samples using this technique. International consensus meeting criteria were used to identify prosthetic joint infection. 50% of the samples were deemed infected based on the above criteria. Results showed that using PCR RFLP Sensitivity and specificity was found to be 97.4% and 100% respectively. This was superior compared to the culture where sensitivity and specificity was 31.6% and 100%. Researchers isolated a broad range of bacteria including fastidious organisms like Chlamydophila pneumonia, Stenotrophomonas maltophilia, Brucella melitensis. One advantage of this technique is the amount of time required to get the pathogen identification is approximately 3 to 4 hours compared to multiple days for microbiological culture methods.

Restriction fragment length polymorphism (RFLP) is a difference in homologous DNA sequences which are identified by the different length of sequences after digestion of DNA samples using specific restriction endonucleases. RFLP probes are widely used in genome mapping and variation analysis such as genotyping, forensics, paternity tests, hereditary disease diagnostics, etc. This process requires a large amount of DNA and is labor intensive.[1] Combining PCR along with RFLP (also called cleaved amplified polymorphic sequences or CAPS) solves the problem of the requirement of a large sample.[2] Using PCR RFLP method with 16s bacterial DNA has been used in bacterial identification in clinical situations, food safety and also identify different strains of bacteria.[3–6] Rohit et al., used this technique to rapidly diagnose bacterial species in the setting of neonatal sepsis.[3] This study provides importance of such technique in PJI setting where it is very important to identify pathogens as it has huge implications in the management.

References

[1] Restriction Fragment Length Polymorphism (RFLP) n.d. https://www.ncbi.nlm.nih.gov/probe/docs/techrflp/ (accessed December 17, 2018).

[2] Cleaved Amplified Polymorphic Sequences (CAPS) n.d. https://www.ncbi.nlm.nih.gov/probe/docs/techcaps/ (accessed December 17, 2018).

[3] Rohit A, Maiti B, Shenoy S, Karunasagar I. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for rapid diagnosis of neonatal sepsis. Indian J Med Res 2016;143:72–8. doi:10.4103/0971-5916.178613.

[4] Schütte UME, Abdo Z, Bent SJ, Shyu C, Williams CJ, Pierson JD, et al. Advances in the use of terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes to characterize microbial communities. Appl Microbiol Biotechnol 2008;80:365–80. doi:10.1007/s00253-008-1565-4.

[5] Meyer R, Höfelein C, Lüthy J, Candrian U. Polymerase chain reaction-restriction fragment length polymorphism analysis: a simple method for species identification in food. J AOAC Int 1995;78:1542–51.

[6] González A, Moreno Y, González R, Hernández J, Ferrús MA. Development of a simple and rapid method based on polymerase chain reaction-based restriction fragment length polymorphism analysis to differentiate Helicobacter, Campylobacter, and Arcobacter species. Curr Microbiol 2006;53:416–21. doi:10.1007/s00284-006-0168-5.

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Paper of the week: Irrigation and debridement with chronic antibiotic suppression for the management of infected total knee arthroplasty

Irrigation and debridement with chronic antibiotic suppression for the management of infected total knee arthroplastyWeston JT, Watts CD, Mabry TM, Hanssen AD, Berry DJ, Abdel MP. Bone Joint J. 2018 Nov;100-B(11):1471-1476.
doi: 10.1302/0301-620X.100B11.BJJ-2018-0515.R1.

Summary and editorial by Sreeram Penna

Above study is a single center retrospective review of 134 infected total knee arthroplasty cases ( acute post-operative infection in 23 and acute hematogenous infection in 111). All patients had Irrigation debridement using normal saline and retention of components except modular poly-ethylene components which were replaced. All patients had organism-specific antibiotic followed by long-term antibiotic suppression.

The study found the infection-free survival of 72% at two years and 66% at five years. The study also showed that age less than 60 and infection with staphylococcal species was associated with increased risk of subsequent infection. Culture-negative infection cases have a lower risk of recurrence or subsequent infections. Musculoskeletal Infection Society host type, body mass index (BMI), the duration of symptoms, gender, and the presence of a monoblock tibial component did not have any influence on the outcome.

In another study Siqueira et al., has shown similar infection-free prosthetic implant survival (68.5% at five years) following irrigation and debridement, polyethylene exchange and chronic antibiotic suppression. [1] However in that study cases with staphylococcal infection fared better following chronic antibiotic suppression compared to those who did not receive suppressive antibiotics following irrigation and debridement. Similarly Rao et al., showed favorable results in 86% of patients at 5 years were able to maintain functioning prosthesis.[2] In another study on patients with osteomyelitis Nowak et al showed successful suppression of the disease. [3] In this study diabetes was associated with a high failure rate and also there was a high incidence (25%) of adverse reactions associated with suppressive antibiotics.

References

[1] Siqueira MBP, Saleh A, Klika AK, O’Rourke C, Schmitt S, Higuera CA, et al. Chronic Suppression of Periprosthetic Joint Infections with Oral Antibiotics Increases Infection-Free Survivorship. J Bone Joint Surg Am 2015;97:1220–32. doi:10.2106/JBJS.N.00999.

[2] Rao N, Crossett LS, Sinha RK, Le Frock JL. Long-term suppression of infection in total joint arthroplasty. Clin Orthop Relat Res 2003:55–60. doi:10.1097/01.blo.0000087321.60612.cf.

[3] Nowak MA, Winner JS, Beilke MA. Prolonged oral antibiotic suppression in osteomyelitis and associated outcomes in a Veterans population. Am J Health Syst Pharm 2015;72:S150-155. doi:10.2146/sp150022.

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Paper of the week: Staphylococcus epidermidis from prosthetic joint infections induces lower IL‐1β release from human neutrophils than isolates from normal flora

Staphylococcus epidermidis from prosthetic joint infections induces lower IL‐1β release from human neutrophils than isolates from normal flora
Emeli Månsson, Bo Söderquist, Åsa Nilsdotter‐Augustinsson, Eva Särndahl, Isak Demirel
APMIS. 2018 Aug;126(8):678-684.
doi: 10.1111/apm.12861.

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Paper of the Week: Pathogen elimination by probiotic Bacillus via signalling interference

Pathogen elimination by probiotic Bacillus via signalling interference

Pipat Piewngam, Yue Zheng, Thuan H. Nguyen, Seth W. Dickey, Hwang-Soo Joo, Amer E. Villaruz, Kyle A. Glose, Emilie L. Fisher, Rachelle L. Hunt, Barry Li, Janice Chiou, Sujiraphong Pharkjaksu, Sunisa Khongthong, Gordon Y. C. Cheung, Pattarachai Kiratisin & Michael Otto

Nature volume 562, pages 532–537 (2018)
Link: https://doi.org/10.1038/s41586-018-0616-y