Salvatore Giovanni De-Simone

By De-Simone SG, Provance DW and Rocha da Silva F

Pertussis, more commonly known as whooping cough, is a potentially fatal respiratory disease caused by Bordetella pertussis. Two different types of vaccines provide effective protection: killed whole-cell vaccines (wPV) and more recently available acellular vaccines (aPVs) formulated with specific components. Disturbingly, while the vaccines are widely used, the incidence of disease is increasing in several developed countries that have switched from wPV to an aPV. It is suggested that the single most important underlying cause suggested for the resurgence is transmission through asymptomatic infections. While both vaccines protect against disease, a newly developed baboon model has shown that they do not prevent infection. Importantly, wPV-vaccinated animals appeared to clear an infection more rapidly than those vaccinated with aPV, which can relate to the period of possible disease transmission. To ultimately control whooping cough, it is clear that a more effective vaccine is needed that can prevent both disease and transmission. Modifications underway include the elimination of LPS from wPVs to improve their safety profiles and augmentation of aPVs with other bacterium proteins to increase immunogenicity and the longevity of protection. In the interim, vaccinations with aPV during pregnancy appear to protect newborns, the most susceptible to deadly pertussis.

Part of the book: Pertussis

By Karyne Rangel and Salvatore Giovanni De-Simone

Antibiotic poly-resistance (multi drug-, extreme-, and pan-drug resistance) is a major global threat to public health. Unfortunately, in 2017, the World Health Organization (WHO) introduced the carbapenemresistant isolates in the priority pathogens list for which new effective antibiotics or new ways of treating the infections caused by them are urgently needed. Acinetobacter baumannii is one of the most critical ESKAPE pathogens for which the treatment of resistant isolates have caused severe problems; its clinically significant features include resistance to UV light, drying, disinfectants, and antibiotics. Among the various suggested options, one of the antimicrobial agents with high potential to produce new anti-Acinetobacter drugs is the antimicrobial peptides (AMPs). AMPs are naturally produced by living organisms and protect the host against pathogens as a part of innate immunity. The main mechanisms action of AMPs are the ability to cause cell membrane and cell wall damage, the inhibition of protein synthesis, nucleic acids, and the induction of apoptosis and necrosis. AMPs would be likely among the main anti-A. baumannii drugs in the post-antibiotic era. Also, the application of computer science to increase anti-A. baumannii activity and reduce toxicity is also being developed.

Part of the book: Insights on Antimicrobial Peptides

By João Pedro R.S. Carvalho and Salvatore Giovanni De-Simone

Electrochemical biosensors currently account for an innovative platform capable of bringing simplicity, ease, and time reduction associated with drug screening, insect capture, DNA detection, and other analytes. Biosensors based on quantum dots are a new alternative unique properties of this nanomaterial to the world of diagnostic medicine and biochemical analysis, among others. In addition to the known optical properties of this nanoparticle, its use presents several advantages when combined with electrochemical detection systems associated with increased sensitivity and accuracy in detecting specific biomolecules, as well as the reduction of the analysis time of the material. This chapter describes in detail the advances and the various applications of these nanoparticles in the field of electrochemical sensors, as well as their advantages and difficulties today.

Part of the book: New Advances in Biosensing

By Guilherme C. Lechuga and Salvatore G. De-Simone

Chagas disease, a neglected tropical disease that affects millions of people worldwide, is caused by Trypanosoma cruzi. The surface of this flagellated parasite is coated with a dense layer of glycoproteins, which play key roles in host-parasite interactions. Among these proteins, enzymatic complexes have been identified, which are involved in several biological processes such as host cell invasion, immune evasion, and nutrient uptake. In this chapter, we review the current knowledge on the enzymatic complexes present in T. cruzi surface, including their structures, functions, and interactions with host molecules. We also discuss the potential of these complexes as targets for the development of novel therapies against Chagas disease. Overall, this chapter provides a comprehensive overview of the enzymatic complexes in T. cruzi surface, highlighting their importance in the pathogenesis of Chagas disease and their potential as therapeutic targets.

Part of the book: Trypanosoma

By Evandro R. Dias, Andressa M. Durans, Luiz A.L. Teixeira-Pinto, David W. Provance and Salvatore G. De-Simone

Chagas disease is an important neglected tropical disease, and this chapter focuses on the prospect of using rapid tests in remote endemic areas for its diagnosis. A major issue with available approaches is the need for a single serological assay with the specificity and sensitivity necessary to deliver results confidently to detect true positives without false positives or negatives. Currently, the WHO and Brazilian Health Ministry recommend performing two tests that utilize different platforms and methodologies. A positive diagnosis of chronic infections requires that both tests return positive results. In cases of divergent results, protocols stipulate applying a third test using another technique and collecting a new sample of biological material is recommended. In remote areas without the laboratory infrastructure and health professionals necessary to perform conventional tests, these requirements result in higher costs and diagnosis delays that disproportionately impact neglected populations. The situation also compromises screening donated blood in blood banks, which leads to discarding bags due to dubious results. Recent advances in key reagents for lateral flow assays and their evaluations suggest that a new generation of rapid tests may improve the diagnosis of chronic Chagas disease.

Part of the book: Trypanosoma

By Karyne Rangel, Thiago Pavoni Gomes Chagas and Salvatore Giovanni De-Simone

Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) have become a global concern. The extensive antibiotic resistance of CRAB has significantly limited treatment options, while its prevalence in hospital outbreaks has amplified infection rates. This scenario has led to a resurgence of interest in polymyxins, an older class of antibiotics previously overlooked due to perceived toxicity. Polymyxins, cationic polypeptide antibiotics, now represent a last-resort treatment option. Despite their historical use, modern assessment methods have only recently been applied to evaluate polymyxins. Two polymyxins are available for clinical use: polymyxin B and colistin (polymyxin E). Notably, the administration of these drugs is hindered by toxicities, primarily nephrotoxicity and neurotoxicity, alongside less common adverse effects such as injection pain, hypersensitivity reactions, and bronchospasms.

Part of the book: Acinetobacter baumannii

By Thiago Pavoni Gomes Chagas, Karyne Rangel and Salvatore Giovanni De-Simone

Acinetobacter baumannii is an important bacterial pathogen associated with healthcare-associated infections (HAIs), especially in critically ill patients admitted to Intensive Care Units (ICU). Its ability to acquire antibiotic resistance determinants has propelled its clinical relevance. The rise in Acinetobacter infections and hospital outbreaks have been extensively described worldwide and are usually caused by carbapenem-resistant isolates. To compound the problem, Carbapenem-resistant A. baumannii (CRAb) isolates are also resistant to a wide range of other antibiotics, representing a serious threat to public health. Since 2017, A. baumannii has been listed as a critical priority pathogen that poses a great threat to human health, according to the World Health Organization (WHO). The carbapenem-resistant rates in A. baumannii are notorious around the world. However, Latin America has one of the highest in the world. Carbapenem resistance in A. baumannii is due mainly to the presence of horizontally acquired OXA-type carbapenem resistance genes, including bla_OXA-23, in most regions. Thus, this review aims to summarize the distribution of CRAb and its major carbapenem resistance mechanisms in Latin America.

Part of the book: Acinetobacter baumannii

By Monica E.T. Alcón-Chino and Salvatore G. De-Simone

Canine Ehrlichiosis is a zoonotic disease transmitted by ticks, posing a global challenge to veterinary and public health. The prevalence of Ehrlichiosis canis varies across regions, emphasizing the need for a comprehensive approach to understanding and combating this illness. This chapter explores its complex pathogenesis, highlighting how the bacterium manipulates the host’s immune response, leading to diverse clinical manifestations. Diagnostic methods, from traditional microscopy to molecular techniques and serology, are critically assessed for their strengths and limitations. By recognizing these nuances, the review equips practitioners with the knowledge for informed decision-making. A key focus is advocating for an integrated “One Health” approach, leveraging genomics, proteomics, and artificial intelligence to improve diagnostics and develop innovative treatments globally. This collaborative framework acknowledges the link between human, animal, and environmental health, offering a holistic strategy against canine Ehrlichiosis. The review synthesizes scientific literature and emphasizes methodological rigor, providing a foundation for future research and interventions. With a commitment to “One Health” principles and advanced technologies, efforts can mitigate the disease’s impact and protect both animal and human well-being.

Part of the book: Exploring the World of Parasites