MICROBIOLOGY


further complicating epidemiological data accuracy.


In the UK, PVL-SA strains are generally


considered rare. However, a recent analysis in a London hospital reported approximately a 20% increase in PVL-SA infections. The report suggested that MRSA with PVL was infrequent (0.8% of all isolates), while MSSA with PVL was more common (9% of all isolates).20


This


contrasts sharply with the prevalence in 2005, which was less than 2% of S. aureus isolates referred to the UK Staphylococcal Reference Unit.21


These figures are


likely to underestimate the true disease burden in the community, as reference units typically receive a limited number of highly selected isolates that may only represent part of the spectrum of clinical disease.20


Owing to the lack of systematic PVL- SA surveillance and reliance on specimens from bacteraemias for UK national staphylococcal surveillance, an increase in PVL-containing strains in the community may go undetected. Given the potential for severe disease, high transmissibility, and reports of antimicrobial resistance compared to PVL-negative strains, rapid and reliable molecular tests are crucial for clinicians to monitor and treat the illness properly. Early diagnosis, appropriate treatment, and patient involvement in preventive measures are vital for reducing disease burden, transmission risk, and adverse psychosocial effects.


Implementing in-house PVL testing In recent years, loop-mediated isothermal amplification (LAMP) has revolutionised pathogen detection, overcoming the limitations of time- consuming culture-based methods and expensive PCR techniques.22


Among


these advancements, the eazyplex MRSA test system (Amplex Diagnostics, Gars- Bahnhof, Germany) stands out as one of the first commercially available qualitative in vitro diagnostic tests based on LAMP technology.


The eazyplex test system (Fig 3) integrates robust isothermal amplification with efficient real-time detection, offering several advantages. The system eliminates the DNA/RNA extraction step by using lyophilised reagents ready for use, as sample preparation buffers are already aliquoted and readily available for immediate use. This streamlines the testing process by bypassing time- consuming and expensive extraction procedures. The amplification signals are displayed in real time, enabling immediate visualisation of the results. Once the run is completed, the results are conveniently summarised in report


48


Fig 3. The eazyplex system is an advanced molecular diagnostics platform that uses LAMP technology for rapid and sensitive pathogen detection with a user-friendly interface.


format. Users can export the results as a PDF or CSV file, or print them directly onto an adhesive label.


The eazyplex MRSA test stands out for its rapid capability to detect S. aureus and differentiate MRSA strains directly from various sample types – such as swabs, blood culture bottles, and cultures – in just 30 minutes. This rapid turnaround time (TAT) decreases the diagnostic delay typical of traditional methods and lowers the risk of sample contamination. Comparative studies have demonstrated the superiority of the eazyplex MRSAplus test over conventional techniques. It offers real-time detection of S. aureus, mecA, mecC, and PVL toxins within 30 minutes, a stark improvement over the approximately three hours required for PCR analysis and the 24 hours needed for bacterial culture. Diagnostic sensitivity has been reported at 83.3% (95% confidence interval [CI] 35.9-99.6), with a specificity of 97.8% (95% CI 88.2-99.9).23 Adopting the eazyplex system markedly reduces TAT for various life-threatening pathogens, including ESKAPE microorganisms, pathogenic E. coli, and Gram-positive and Gram- negative pathogens linked to sepsis and meningitis. Results for detecting these pathogens – which usually take 24 hours to three days – are expedited with the eazyplex system, enhancing diagnostic efficiency and patient outcomes.


Conclusions


The eazyplex test system simplifies diagnostics, enabling clinicians to use toxin test results alongside clinical history and examination to make informed treatment decisions. Integrating isothermal amplification with a real-time fluorometer in compact devices like


the Genie II makes S. aureus detection straightforward and cost-effective. It is suitable for near-patient testing and reduces contamination risk by eliminating the need for sample transportation. The eazyplex MRSA test offers precise


S. aureus detection, mecA, mecC gene identification, and PVL toxin detection, delivering earlier results and expediting appropriate treatment.


References 1 Santajit S, Indrawattana N. Mechanisms


of Antimicrobial Resistance in ESKAPE Pathogens. Biomed Res Int. 2016;2016:2475067. doi:10.1155/2016/2475067.


2 Li Z, Xie J, Yang J, et al. Pathogenic Characteristics and Risk Factors for ESKAPE Pathogens Infection in Burn Patients. Infect Drug Resist. 2021 Nov 12;14:4727-4738. doi:10.2147/IDR. S338627.


3 American Society for Microbiology. FAQ: The Threat of MRSA. (ASM, 2015) https:// www.ncbi.nlm.nih.gov/books/NBK562897/


4 Missiakas DM, Schneewind O, Growth and Laboratory Maintenance of Staphylococcus aureus. Curr Protoc Microbiol. 2013 Feb; Chapter 9: Unit 9C.1. https://doi. org/10.1002/9780471729259.mc09c01s28


5 Rajesh M, Samundeeswari M, Archana B. Isolation of Biosurfactant Producing Bacteria from Garbage Soil. Journal of Applied & Environmental Microbiology. 2017, 5(2), 74-78. doi:10.12691/jaem-5-2-3


6 American Society for Microbiology. Visual Resources. (ASM, 2024) www.microbelibrary.org


7 Hartman BJ, Tomasz A. Low-affinity penicillin-binding protein associated with beta-lactam resistance in Staphylococcus aureus. J Bacteriol. 1984;158(2):513-516. doi:10.1128/jb.158.2.513-516.1984.


JUNE 2024 WWW.PATHOLOGYINPRACTICE.COM


• C. difficile • Sepsis • STD • MRSA • Salmonella


• Candida auris • Pneumocystis • Meningitis


• Antibiotic resistance


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