Editorial: Microbial Biofilms in Chronic and Recurrent Infections

Biofilm plays a significant role in the pathogenesis of most chronic infections in humans, either tissue-specific or involving medical implants (Lebeaux et al., 2014). Biofilm-associated infections exhibit high resistance to host defenses, often contributing to an excessive or inappropriate inflammatory response leading to further tissue damage and spreading of the infection (Jensen et al., 2010). On the other hand, biofilms are highly tolerant to antimicrobial therapy (Römling and Balsalobre, 2012; Di Domenico et al., 2019). Biofilms can tolerate up to 100–1,000 times higher minimal inhibitory concentration (MIC) than the same bacterial cells in planktonic growth (Macià et al., 2014). Unfortunately, the effective antibiotic MIC in vivo for biofilm eradication may be impossible to reach due to the drugs’ toxicity and side effects, including limitations imposed by renal and/or hepatic functions (Ciofu et al., 2015). However, in vitro experiments showed that an aggressive antibiotic treatment can effectively eradicate biofilm during the initial stage of colonization (Lebeaux et al., 2014; Ciofu et al., 2015). Despite their importance, the early recognition of biofilm-associated infections still represents an unmet need in clinical microbiology. Therefore, the development of novel diagnostic and therapeutic strategies is urgently needed to manage biofilm-associated infections effectively.