1. Introduction
Brucella are facultative intracellular bacteria that cause
infections in animals and humans called brucellosis. So far, ten species
have been characterized with four typical species (Brucella
melitensis , Brucella abortus , Brucella suis , andBrucella canis ) which are known to cause disease in humans
(S. Li et al., 2019;
Pal et al., 2017). Although brucellosis
is a common zoonotic disease, it is
believed that humans are encountered accidentally
(Taheri, Amini, Kamali, Asadi, &
Naderlou, 2020). The disease is associated with acute symptoms
including fever, lethargy, chill, weight loss, and arthralgia in humans.
However, the infection may affect various organs and become chronic with
signs such as osteomyelitis, orchitis, and endocarditis, etc
(Pereira et al., 2020). But in animals,
the infection may cause abortion storm in sensitive herds and therefore,
it is very important in livestock and quick diagnosis is necessary to
prevent the spread of the infection and subsequent economic losses
(Taheri et al., 2020).
Blood culture is considered as the gold standard method to identifyBrucella spp. Hwoever, a sensitivity around 15% to 70% has been
reported for this method respect to the PCR (Polymerase chain reaction)
assay. Meanwhile, several serological tests are used to detect
infections caused by Brucella spp, including the Bengal Rose
test, 2-mercaptoethanol, Wright,
Coombs Wright, and serum agglutination test. Nevertheless, they have low
sensitivity and specificity, long response time, false positive result,
operational complexity, and difficulties in real-time monitoring
(Alves et al., 2010).
On the other side, the molecular techniques that work on the basis of
DNA detection like PCR, are not only fast (>4 hour), but
also make it possible to molecularly type the isolates without exposure
to the infectious Brucella cells
(Alves et al., 2010). Yet,
the common PCR assay has its own
limitations in detection of PCR products and interpretation of the
results e.g. lack of convineincy and sensitivity, need for costly
equipment, complex sample preparation, and skilled personnel requirement
(Sattarahmady, Kayani, & Heli, 2015).
Consequently, it is extremely important to develop more simple,
sensitive, and inexpensive methods for detecting Brucella spp to
overcome these limitations (Sattarahmady
et al., 2015).
Application of biosensors has been the novel approach for the
scientists. {Sattarahmady, 2015 #146;Sattarahmady, 2015 #146}Using
biosensors, the sensitivity and specificity of detection methods have
recently been improved for various pathogenic bacteria. Biosensors are
analytical biodevices that convert
the biological responses into electrical signals. These agents generally
consist of a bioreceptor (e.g., antibodies, enzymes, nucleic acids
(DNA/RNA/aptamers), microorganisms, etc.) with a physical transducer
(optical, electrochemical, or mass-based) to generate a measurable
signal (Rubab, Shahbaz, Olaimat, & Oh,
2018). Many novel signal transduction systems are being developed by
using nanoparticles to further improve strategies for detection of
pathogens (Narmani et al., 2018).
In this case, several biosensors
have been designed based on the
engagement of diverse nanoparticles
such as magnetic-, silica-, gold-nanoparticles, and quantum dots, and
introduced for the characterization of pathogenic bacteria
(Ahangari, Salouti, & Saghatchi, 2016;
Narmani et al., 2018). The present review
has described the recent developments of various nanobiosensors for the
detection of Brucella spp.