Pseudomonas aeruginosa Biofilm Formation and Its Control

Abstract

Microbes are hardly seen as planktonic species and are most commonly found as biofilm communities in cases of chronic infections. Biofilms are regarded as a biological condition, where a large group of microorganisms gets adhered to a biotic or abiotic surface. In this context, Pseudomonas aeruginosa, a Gram-negative nosocomial pathogen is the main causative organism responsible for life-threatening and persistent infections in individuals affected with cystic fibrosis and other lung ailments. The bacteria can form a strong biofilm structure when it adheres to a surface suitable for the development of a biofilm matrix. These bacterial biofilms pose higher natural resistance to conventional antibiotic therapy due to their multiple tolerance mechanisms. This prevailing condition has led to an increasing rate of treatment failures associated with P. aeruginosa biofilm infections. A better understanding of the effect of a diverse group of antibiotics on established biofilms would be necessary to avoid inappropriate treatment strategies. Hence, the search for other alternative strategies as effective biofilm treatment options has become a growing area of research. The current review aims to give an overview of the mechanisms governing biofilm formation and the different strategies employed so far in the control of biofilm infections caused by P. aeruginosa. Moreover, this review can also help researchers to search for new antibiofilm agents to tackle the effect of biofilm infections that are currently imprudent to conventional antibiotics.

Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria

“…Biofilm formation is induced by different factors including changes in the environmental conditions including oxidative stress, alterations in nutritional and metabolic cues, low pH, starvation, heavy metals, host-derived signals, toxic compounds, QS signals, and subinhibitory concentrations of antimicrobials [20,[503][504][505][506][507][508][509][510][511][512]. For instance, biofilm formation of Salmonella typhimurium is induced by acidic stress and bile salts under oxygen-limiting conditions in the stomach and the small intestine [513].…”

“…Many secondary plant metabolites have been shown to have anti-quorum and antibiofilm activity, which may increase the sensitivity of bacteria to antibiotics [509,927,928]. These compounds are part of the plant defense system to avoid microbial infections.…”

Current Advances in the Concept of Quorum Sensing-Based Prevention of Spoilage of Fish Products by Pseudomonads

“…Swarming motility, which is an organized form of structure translocation, is useful in the early stages of biofilm development and is regulated by the rhl system similarly to twitching motility-a flagella-independent way of translocation necessary for microcolony development [48]. EPS holds all cells of biofilm in the near vicinity to enable QS interactions [49]. Rhamnolipid production is involved in several aspects of biofilm formation, such as the formation of microcolonies, maintaining the open channel structure, facilitating mushroom-shaped structures, and aiding cell dispersion [50].…”

A Combination of the Natural Molecules Gallic Acid and Carvacrol Eradicates P. aeruginosa and S. aureus Mature Biofilms

“…Biofilm formation is composed of three phases: (1) attachment of planktonic bacteria to the wound surface and (2) growth and production of the extracellular matrix, maturation and (3) dispersion [6]. In a wound, bacterial biofilms can be well established within a few hours [7], being considered mature biofilms.…”