Probiotic-Loaded Bacterial Cellulose as an Alternative to Combat Carbapenem-Resistant Bacterial Infections

<b>Background:</b> Carbapenems are one of the mainstays of treatment for antibiotic-resistant bacteria (ARB). This has made the rise of carbapenem-resistant bacteria a threat to global health. In fact, the World Health Organization (WHO) has identified carbapenem-resistant bacteria as critical pathogens, and the development of novel antibacterials capable of combating infections caused by these bacteria is a priority. <b>Objective</b>: With the aim of finding new alternatives to fight against ARB and especially against carbapenem-resistant bacteria, we have developed a series of living materials formed by incorporating the probiotics <i>Lactobacillus plantarum</i> (<i>Lp</i>), <i>Lactobacillus fermentum</i> (<i>Lf</i>), and a mixture of both (<i>L. plantarum</i>+<i>L. fermentum</i>) into bacterial cellulose (BC). <b>Results</b>: These probiotic-loaded bacterial celluloses inhibited the proliferation of three ARB, including two carbapenem-resistant enterobacteria (CRE), identified as <i>Klebsiella pneumoniae</i> and <i>Enterobacter cloacae</i>, and a carbapenem-resistant <i>Pseudomonas aeruginosa</i>. Interestingly, while the probiotics <i>L. plantarum</i>, <i>L. fermentum</i>, and the mixture of both were found to be inactive against these ARB, they became active once incorporated into BC. <b>Conclusions</b>: The increase in activity is due to the known effect that cells increase their activity once incorporated into a suitable matrix, forming a living material. For the same reasons, the probiotics in the living materials BC-<i>L. plantarum</i>, BC-<i>L. fermentum</i>, and BC-<i>L. plantarum</i>+<i>L. fermentum</i> showed increased stability, allowing them to be stored with bacterial activity for long periods of time (two months).