Unlocking Microbiology: MPC (Multi-Porosity Cross-Linked) Resin Bottles for Rapid Positive Reporting

2025-09-29

In-Vitro Diagnostics
Microbiology
Smart applications
Unlocking Microbiology: MPC (Multi-Porosity Cross-Linked) Resin Bottles for Rapid Positive Reporting key visual

Clinical Challenge: How to Achieve Rapid and Accurate Diagnosis of Bloodstream Infections

When patients present with fever and suspected bloodstream infection, physicians typically initiate empirical antibiotic therapy immediately, using broad-spectrum antimicrobials to stabilize the condition. However, the administration of antibiotics poses challenges to reliable positive reporting in blood cultures.

 

If antibiotics have been administered prior to blood collection, these drugs persist in the bloodstream and continue to inhibit microbial growth after entering the blood culture bottles, leading to delayed pathogen detection or even false-negative results. This undoubtedly complicates clinical decision-making in time-sensitive scenarios.

 

Mindray has recognized this clinical bottleneck and developed the new generation of resin blood culture bottles, utilizing professional innovation to assist physicians in rapidly identifying the truth of infections!

FA-N Series Automated Microbial Culture System

Industry Challenge: How to Overcome Constraints

The secret of blood culture bottles lies in resin! Through customized development, Mindray has innovatively adopted MPC (Multi-Porosity Cross-Linked) Resin, significantly mitigating the challenge of antibiotic interference.

 

The resin in blood culture bottles serves as a protector for microbial growth, neutralizing antibiotics in the blood and restoring a normal microbial environment. Specifically, there are two key types of resin used in blood culture bottles:

 

1. Macroporous adsorption resin

Macroporous adsorption resin possesses a porous three-dimensional network structure (Broussonetia papyrifera) and selectively adsorbs organic compounds such as antibacterial drugs through physical or chemical interactions. Macroporous adsorption resin relies on hydrophobic interactions and van der Waals forces to adsorb substances via its abundant internal specific surface area, making it suitable for adsorbing non-polar antibacterial drugs (e.g., vancomycin, fluconazole) from polar solvents (e.g., water). The adsorption mechanism is illustrated in the figure.

Macroporous adsorption resin
Advantages:

Adsorption resins offer several advantages over other adsorbent materials, such as activated carbon.

  1. Exceptional adsorption capacity: High selectivity for organic compounds, with inorganic salts not only non-interfering but even facilitating adsorption.
  2. Stability and reliability: High physical and chemical stability with robust mechanical strength.
  3. Spherical design: The bead-like form reduces fluid resistance and enhances manufacturability.
Disadvantages:
  1. Adsorbs nutrients in the blood culture bottle (e.g., proteins, polysaccharides, amino acids, and growth factors), negatively impacting microbial growth.
  2. Interferes with CO₂ production and detection: Some microbes may adhere to the resin, leading to insufficient CO₂ production and affecting instrument signal recognition and positive reporting.
  3. Poor adsorption performance for highly hydrophilic antibiotics (e.g., ceftazidime, cefepime).
2. Ion Exchange Resin

Selectively captures specific antibiotics through ion exchange between functional groups on the resin surface and ions in the solution.

 

Ion exchange reaction formula:

R-SO₃-H + NaCl ⇌ R-SO₃-Na + HCl or R-NH₂-OH + HCl ⇌ R-NH₂-Cl + H₂O

Ion Exchange Resin
Advantages:

Ion exchange resin is a polymer with specific functional groups that selectively remove or enrich target ions through reversible exchange reactions. Driven by concentration and pH gradients, high-concentration ions in the solution exchange with load ions on the resin, effectively eliminating certain types of antibiotics.

Disadvantages:

Adsorption priority: In blood cultures, antibiotics have lower adsorption priority compared to inorganic salts, significantly impacting the medium’s inorganic salt balance. Thus, ion exchange resin is used sparingly in blood culture bottles as a supplementary adsorbent.

Mindray Breakthrough: MPC (Multi-Porosity Cross-Linked) Resin Blood Culture Bottles

The development of suitable resin is critical in blood culture bottle R&D. Not all commercially available resins meet this requirement; specific resins must be selected that effectively adsorb clinically common antibiotics without significantly adversely affecting the culture medium system.

 

In collaboration with a national key laboratory, Mindray conducted in-depth research on approximately 100 types of resins domestically and internationally. Through customized development, we successfully engineered a MPC (Multi-Porosity Cross-Linked) Resin. Compared to traditional resins, its specific surface area increased by 100%, with precisely designed pore size and distribution, enabling efficient adsorption and capture of a wide range of clinically used antibiotics.

MPC Resin Blood Culture Bottles

Furthermore, through formulation optimization, we balanced the ratio of MPC (Multi-Porosity Cross-Linked) Resin and Ion Exchange Resin, adding chemical neutralizers to the medium to comprehensively expand the spectrum of neutralizable antibiotics (see chart for details).

MPC Resin Blood Culture Bottles - Resin Particles Detail

This innovative resin has been successfully applied in Mindray’s new-generation blood culture bottles. When used with the FA-N Series Automated Blood Culture System, it significantly enhances positive detection rates and reduces time-to-positivity. This achievement provides a more efficient and precise solution for clinical microbial blood culture testing.
No. Antibiotic Class Antibiotic Name Max Peak Blood Conc. (μg/mL) Neutralization Capability
1 Glycopeptides Vancomycin 50 Neutralizable
2 Glycopeptides Teicoplanin 111.8 Neutralizable
3 Quinolones Levofloxacin 12.1 Neutralizable
4 Quinolones Moxifloxacin 4.6 Neutralizable
5 Quinolones Ciprofloxacin 4.6 Neutralizable
6 Aminoglycosides Gentamicin 24 Neutralizable
7 Aminoglycosides Amikacin 64 Neutralizable
8 Aminoglycosides Etimicin 19.79 Neutralizable
9 Penicillins Penicillin G 20 Neutralizable
10 Penicillins Oxacillin 43 Neutralizable
11 Penicillins Piperacillin 400 Neutralizable
12 Enzyme Inhibitors Piperacillin-Tazobactam 242/24 Neutralizable
13 Triazoles Posaconazole 3.3 Neutralizable
14 Triazoles Fluconazole 14 Neutralizable
15 Triazoles Voriconazole 3 Neutralizable
16 Echinocandins Caspofungin 8.7 Neutralizable
17 Polyenes Amphotericin 3.5 Neutralizable
18 Macrolides Azithromycin 3.6 Neutralizable
19 Oxazolidinones Linezolid 20 Neutralizable
20 Glycylcyclines Tigecycline 0.63 Neutralizable
21 Lipopeptides Daptomycin 99 Neutralizable
22 Polymyxins Colistin 7.5 Neutralizable
23 Sulfonamides Cotrimoxazole 9/105 Neutralizable
24 Carbapenems Imipenem 40 Neutralizable (Anaerobic)
25 Penicillins Ampicillin 100 Partially Neutralizable
26 Carbapenems Meropenem 49 Partially Neutralizable
27 Cephalosporins Cefuroxime 100 Partially Neutralizable
28 Cephamycins Cefoxitin 110 Partially Neutralizable
29 Enzyme Inhibitors Cefoperazone-Sulbactam 236.8/130.2 Partially Neutralizable
30 Cephalosporins Cefazolin 188 Partially Neutralizable
31 Cephalosporins Ceftriaxone 150 Partially Neutralizable
32 Cephalosporins Cefotaxim 100 Partially Neutralizable
33 Enzyme Inhibitors Ceftazidime-Avibactam 90.4/14.6 Not Neutralizable
34 Cephalosporins Ceftazidime 69 Not Neutralizable
35 Cephalosporins Cefepime 164 Not Neutralizable
36 Oxacephems Latamoxef 101 Not Neutralizable
37 Nitroimidazoles Metronidazole 25 Not Neutralizable
Table 1. Neutralizable Categories of Clinically Common Antibiotics

FA-N Series Automated Blood Culture System: Rapid Pathogen Detection, Powerful Antibiotic Adsorption

Mindray's new-generation resin blood culture bottles—empowered by superior antibiotic adsorption and enhanced pathogen detection—revolutionize clinical diagnostics. Unshaken by antimicrobial interference, unwavering in timely reporting, they enable clinicians to swiftly identify the cause of infection and deploy precisely targeted treatments at critical moments.

FA-N Series Automated Microbial Culture System
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