Yasmine Eddoubaji, Claudia Aldeia, Dierik H Heg, Edgar I Campos-Madueno, Andrea Endimiani
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引用次数: 0
Abstract
Background: The darkling beetle Zophobas morio can be implemented as an alternative in vivo model to study different intestinal colonization aspects. Recently, we showed that its larvae can be colonized by multidrug-resistant Escherichia coli strains administered via contaminated food (for 7 days) for a total experimental duration of 28 days.
Method: In the present work, we aimed to shorten the model to 14 days (T14) by administering the previously used CTX-M-15 ESBL-producing ST131 Escherichia coli strain Ec-4901.28 via a single oral administration (5 µL dose of 108 CFU/mL) , using a blunt 26s-gauge needle connected to a 250 μL gastight syringe. Force-feeding was performed either without or with (larvae placed on ice for 10 minutes before injection) anesthesia. In addition, phage-treated larvae were orally injected with 10 µL of INTESTI bacteriophage cocktail (∼105-6 PFU/mL) on days 4 (T4) and 7 (T7) .
Results: Growth curve analyses showed that, while larvae rapidly became colonized with Ec-4901.28 (T1, ∼106-7 CFU/mL) , only those anesthetized maintained a high bacterial load (∼102-3vs. ∼105-6 CFU/mL) and survival rate (76% vs. 99%; P<0.001) by T14. Moreover, bacteriophage administration to anesthetized larvae significantly reduced the bacterial count of INTESTI-susceptible Ec-4901.28 at T14 (5.17 × 105vs. 2.26 × 104, for non-treated and phage-treated larvae, respectively; P=0.04) .
Conclusion: The methodological refinements applied to establish the intestinal colonization model simplify the use of Z. morio larvae, facilitate prompt evaluation of novel decolonization approaches and reduce experiments involving vertebrate animals in accordance with the Replacement, Reduction and Refinement principles.
期刊介绍:
The Journal of Global Antimicrobial Resistance (JGAR) is a quarterly online journal run by an international Editorial Board that focuses on the global spread of antibiotic-resistant microbes.
JGAR is a dedicated journal for all professionals working in research, health care, the environment and animal infection control, aiming to track the resistance threat worldwide and provides a single voice devoted to antimicrobial resistance (AMR).
Featuring peer-reviewed and up to date research articles, reviews, short notes and hot topics JGAR covers the key topics related to antibacterial, antiviral, antifungal and antiparasitic resistance.