Introduction pressure, resulting in the emergence of

Introduction

Accidental
outbreak of antibiotics such as penicillin aided and revolutionized the entire
world until the excessive use of these antibacterial compounds in form of drugs
lead to an increased selection pressure, resulting in the emergence of drug
resistance among the monera kingdom (Levy and Marshall 2004). People are
facing problems as they are running out of antimicrobial solutions. Among many
there is the Genus Acinetobacter, was first isolated and described by
Beijerinck in 1911. Acinetobacter spp. are glucose-non-fermentative,
non-motile, non-fastidious, catalase-positive, oxidative-negative, aerobic
Gram-negative coccobacilli (Lee, Lee et al. 2017). World Health
Organization reported Acinetobacter
baumannii as the most serious ESKAPE bacterium which showed an increased
ability against antibacterial drugs (Boucher, Talbot et al. 2009). Acinetobacter baumannii is a nosocombial
pathogen found specially in intensive care units (Fournier, Richet et al. 2006) and around 70%
of the hospital acquired infections are caused by medical implants (Bryers 2008) which has
reluctantly increased the mortality rate. These single celled organisms
co-aggregate themselves while forming a structure called biofilm (Rickard, Gilbert et al. 2003).  Bacteria can switch between its single celled
planktonic forms and co aggregated biofilm form, its formation involves 4 major
steps- 1) Attachment to a substratum 2) Microcolony formation 3) Maturation 4)
Detachment and colonization to some other area (Landini, Antoniani et al. 2010). In biofilms
the planktonic counterparts of the bacteria, Staphylococcus aureus attaches to a substratum through proteins
like Bap (Cucarella, Solano et al. 2001) and produces
polymeric matrix consisting of polysaccharides, proteins and extracellular DNA
which aid the formation and growth of bacterial communities(Donlan 2002). These biofilms
restricts the penetration of the antibiotics and other harmful compounds (Singh, Ray et al. 2010). Increased
heterogeneity and changed gene expression due to the altered growth dynamics
are the major reasons for the emergence of MDR strains (Yoon, Courvalin et al. 2013) (Richmond, Evans et al. 2016). The bacterial
communities within the biofilm communicate in various ways for their extended
survival even in nutrient limiting conditions and somehow manages to avoid
competition within the biofilms, the stressed interior cells releases potassium
ion wave that would signal the peripheral cells to reduce its glutamate uptake
or retain its ammonium so that most nutrition in form of glutamate reaches the
interior (Prindle, Liu et al. 2015). This cell within the biofilms interact  by 3 methods mainly Quorum sensing (cell-cell
communication) (Papenfort
and Bassler 2016) and recently studied
Electrochemical signaling (via the potassium ion wave) (Prindle,
Liu et al. 2015). Potassium ion channels YugO gated
by TrkA domain, and a potassium ion pump KtrA studied in the Bacillus subtilis (Prindle, Liu et al. 2015). These potassium ion waves not only sensitize the distant
cells but also increase their proton motive force which lead to an increased
oscillatory motility of the distant cells towards the preformed biofilm
regardless of the species i.e. generic attractions, leading
to the incorporation of diverse species into a pre-existing biofilm resulting
in increased viability studies seen  in Bacillus subtilis (Humphries, Xiong et al. 2017). Bacterial biofilms is the optimum solution for the survival of
pathogenic bacteria due to the increased competence cellular eDNA uptake which
allow them to modify their strains resulting in antibiotic resistance studies
showed the same in Pseudomonas aeruginosa
(Lewenza 2013),
hence there is an emerging need to find an eminent solution to block the
electrical signaling thereby blocking their
propagation.