140
both at the physical and molecular levels to analyze their future potential as significant alternatives to antibiotics.
Keywords Nanoparticles · Nanotoxicity · Drug-resistant bacteria · Antimicrobial
resistance · Multi-drug resistance
6.1 Introduction
The unprecedented rise of drug-resistant bacteria is posing a grave threat to public
health. Resistance against several classes antibiotics has also paved way for
increased prevalence of multidrug resistance in bacteria, leading to adverse health
outcomes (Ebinesh 2017). Microbial drug resistance or antimicrobial resistance (AMR), driven by misuse of antimicrobials in humans and animals, has
resulted in them becoming more and more ineffective. This is further manifested by
longer patient-recovery periods, extended hospital stays, and costlier treatment processes (Perron et al. 2015). Moreover, increasing rates of AMR could also potentially undo many of the medical advances made globally (Tanwar et al. 2014).
The World Health Organization has highlighted AMR as one of the top ten
threats to global health. The first report of the Global Antimicrobial Resistance
Surveillance System outlines alarmingly high levels of resistance in common
infection- causing bacteria (World Health Organization 2017). In 2016, 490,000
people are said to have developed multidrug-resistant tuberculosis globally
(Tacconelli et al. 2018). Drug resistance is also beginning to complicate HIV and
malaria treatments (Goldberg et al. 2012). It is reported that at least 23,000 people
in the United States died of infections caused by antibiotic-resistant bacteria
(Centers for Disease Control and Prevention 2017). If not addressed urgently,
AMR is estimated to lead to almost ten million deaths and economic losses worth
100 trillion dollars by the year 2050 (O’Neill 2016).
The scenario above calls for newer strategies and solutions to tackle the burden
of drug-resistant infections. These include approaches such as discovery of new
antimicrobials or alternatives to kill bacteria, modification of existing antibiotics,
development of antimicrobial peptides, or introducing vaccination as a preventive
measure against infections. The use of the antimicrobial properties of nanoparticles
has also shown a promising potential (Hemeg 2017; Rudramurthy et al. 2016; Sinha
and Khare 2014). The toxic effect of nanoparticles on bacteria has been well documented. Metal nanoparticles, metal oxide nanoparticles, and quantum dots have
been shown to inhibit growth of common infection-causing bacteria such as E. coli,
P. aeruginosa, S. aureus. (Adams et al. 2014; Guzman et al. 2012; Lara et al. 2010b;
Sinha et al. 2011). Variation in nanotoxicity levels has been observed with the
nanoparticle shape, size, and concentration (Lu et al. 2013; Tam et al. 2008;
Yamanaka et al. 2005).
Historically, silver nanoparticles have been commonly explored as effective biocidal agents against a wide range of bacteria (Marambio-Jones and Hoek 2010; Rai
R. Sinha et al.
both at the physical and molecular levels to analyze their future potential as significant alternatives to antibiotics.
Keywords Nanoparticles · Nanotoxicity · Drug-resistant bacteria · Antimicrobial
resistance · Multi-drug resistance
6.1 Introduction
The unprecedented rise of drug-resistant bacteria is posing a grave threat to public
health. Resistance against several classes antibiotics has also paved way for
increased prevalence of multidrug resistance in bacteria, leading to adverse health
outcomes (Ebinesh 2017). Microbial drug resistance or antimicrobial resistance (AMR), driven by misuse of antimicrobials in humans and animals, has
resulted in them becoming more and more ineffective. This is further manifested by
longer patient-recovery periods, extended hospital stays, and costlier treatment processes (Perron et al. 2015). Moreover, increasing rates of AMR could also potentially undo many of the medical advances made globally (Tanwar et al. 2014).
The World Health Organization has highlighted AMR as one of the top ten
threats to global health. The first report of the Global Antimicrobial Resistance
Surveillance System outlines alarmingly high levels of resistance in common
infection- causing bacteria (World Health Organization 2017). In 2016, 490,000
people are said to have developed multidrug-resistant tuberculosis globally
(Tacconelli et al. 2018). Drug resistance is also beginning to complicate HIV and
malaria treatments (Goldberg et al. 2012). It is reported that at least 23,000 people
in the United States died of infections caused by antibiotic-resistant bacteria
(Centers for Disease Control and Prevention 2017). If not addressed urgently,
AMR is estimated to lead to almost ten million deaths and economic losses worth
100 trillion dollars by the year 2050 (O’Neill 2016).
The scenario above calls for newer strategies and solutions to tackle the burden
of drug-resistant infections. These include approaches such as discovery of new
antimicrobials or alternatives to kill bacteria, modification of existing antibiotics,
development of antimicrobial peptides, or introducing vaccination as a preventive
measure against infections. The use of the antimicrobial properties of nanoparticles
has also shown a promising potential (Hemeg 2017; Rudramurthy et al. 2016; Sinha
and Khare 2014). The toxic effect of nanoparticles on bacteria has been well documented. Metal nanoparticles, metal oxide nanoparticles, and quantum dots have
been shown to inhibit growth of common infection-causing bacteria such as E. coli,
P. aeruginosa, S. aureus. (Adams et al. 2014; Guzman et al. 2012; Lara et al. 2010b;
Sinha et al. 2011). Variation in nanotoxicity levels has been observed with the
nanoparticle shape, size, and concentration (Lu et al. 2013; Tam et al. 2008;
Yamanaka et al. 2005).
Historically, silver nanoparticles have been commonly explored as effective biocidal agents against a wide range of bacteria (Marambio-Jones and Hoek 2010; Rai
R. Sinha et al.