Leptospirosis is a perplexing conundrum for many. In the existing literature, the pathophysiological mechanisms pertaining to leptospirosis is still not understood in full. Considered as a neglected tropical zoonotic disease, leptospirosis is culminating as a serious problem worldwide, seemingly existing as co-infections with various other unrelated diseases, including dengue and malaria. Misdiagnosis is also common as non-specific symptoms are documented extensively in the literature. This can easily lead to death, as the severe form of leptospirosis (Weil’s disease) manifests as a complex of systemic complications, especially renal failure. The virulence of Leptospira sp. is usually attributed to the outer membrane proteins, including LipL32. With an armament of virulence factors at their disposal, their ability to easily adhere, invade and replicate within cells calls for a swift refinement in research progress to establish their exact pathophysiological framework. As an effort to reconstitute the current knowledge on leptospirosis, the basis of leptospiral infection, including its risk factors, classification, morphology, transmission, pathogenesis, co-infections and clinical manifestations are highlighted in this review. The various diagnostic techniques are also outlined with emphasis on their respective pros and cons.

Biofilms comprising aggregates of microorganisms or multicellular communities have been a major issue as they cause resistance against antimicrobial agents and biofouling. To date, numerous biofilm-forming microorganisms have been identified, which have been shown to result in major effects including biofouling and biofilm-related infections. Quorum sensing (which describes the cell communication within biofilms) plays a vital role in the regulation of biofilm formation and its virulence. As such, elucidating the various mechanisms responsible for biofilm resistance (including quorum sensing) will assist in developing strategies to inhibit and control the formation of biofilms in nature. Employing biological control measures (such as the use of bioactive compounds) in targeting biofilms is of great interest since they naturally possess antimicrobial activity among other favorable attributes and can also possibly act as potent antibiofilm agents. As an effort to re-establish the current notion and understanding of biofilms, the present review discuss the stages involved in biofilm formation, the factors contributing to its development, the effects of biofilms in various industries, and the use of various bioactive compounds and their strategies in biofilm inhibition.

Polysaccharides from plant gum, chitosan from animal origin, and other polysaccharides are biologically active, nontoxic, biodegradable, and biocompatible with a wider range of clinical and general applications. The properties of these biological‐derived polysaccharides play a major role in their application. This review outlines the different techniques used in the extraction of polysaccharides from plant and animal sources. The importance of the purity of polysaccharides is crucial; thus, techniques such as deproteination and other chromatography techniques are elaborated. Evaluation of properties of polysaccharides using spectroscopy methods, including UV–Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, x‐ray diffraction (XRD), thermogravimetric analysis (TGA), and microscopic methods, including scanning electron microscopy (SEM) and transmission electron microscopy, is detailed. These biological polysaccharides have been used in various fields including tissue engineering, nanotechnology, and drug delivery. These applications are elaborately covered in detail in this review.