Publications by authors named "Alessandra A Souza"

Article Synopsis
  • The study investigates how N-acetylcysteine (NAC) can disrupt extracellular polymeric substances (EPS) in bacterial biofilms, which help protect bacteria from treatments.
  • Researchers used microscopy techniques to observe NAC's effects on single cells and early biofilms of the Xylella fastidiosa bacteria.
  • The findings suggest that NAC significantly alters both soluble and tightly bound EPS, enhancing bacterial mobility and potentially aiding in the treatment of bacterial infections.
View Article and Find Full Text PDF

Citrus canker disease, caused by subsp. , poses a significant threat to global citrus production. The control of the disease in the field relies mainly on the use of conventional tools such as copper compounds, which are harmful to the environment and could lead to bacterial resistance.

View Article and Find Full Text PDF

Background: Xylella fastidiosa is a multi-host bacterium that can be detected in hundreds of plant species including several crops. Diseases caused by X. fastidiosa are considered a threat to global food production.

View Article and Find Full Text PDF
Article Synopsis
  • - The article highlights the shift towards open access in scientific publishing, emphasizing the need for research outputs like data, code, and publications to be freely available.
  • - It offers best practices for publishing in The American Phytopathological Society journals, covering critical topics such as diagnostic assays, experimental design, and data sharing.
  • - The goal is to enhance reproducibility and effective use of research resources, ultimately improving understanding of biological effects in plant pathology.
View Article and Find Full Text PDF

Gene editing technologies have opened up the possibility of manipulating the genome of any organism in a predicted way. CRISPR technology is the most used genome editing tool and, in agriculture, it has allowed the expansion of possibilities in plant biotechnology, such as gene knockout or knock-in, transcriptional regulation, epigenetic modification, base editing, RNA editing, prime editing, and nucleic acid probing or detection. This technology mostly depends on tissue culture and genetic transformation/transfection protocols, which sometimes become the major challenges for its application in different crops.

View Article and Find Full Text PDF

Xanthomonas is an important genus of plant-associated bacteria that causes significant yield losses of economically important crops worldwide. Different approaches have assessed genetic diversity and evolutionary interrelationships among the Xanthomonas species. However, information from clustered regularly interspaced short palindromic repeats (CRISPRs) has yet to be explored.

View Article and Find Full Text PDF

Transcription activator-like effectors are key virulence factors of . They are secreted into host plant cells and mimic transcription factors inducing the expression of host susceptibility (S) genes. In citrus, is a direct target of PthA4, the primary effector associated with citrus canker symptoms.

View Article and Find Full Text PDF

Background: Ozone is a molecule that plays an important role in dentistry, specially for wound healing. The aim of the present study was to clinically and immunologically evaluate the effect of ozonated oil on the healing of palatal wounds.

Methods: This is a prospective, longitudinal, triple-blind, randomized, placebo-controlled clinical trial.

View Article and Find Full Text PDF

SU-8 polymer is an excellent platform for diverse applications due to its high aspect ratio of micro/nanostructure fabrication and exceptional physicochemical and biocompatible properties. Although SU-8 polymer has often been investigated for various biological applications, how its surface properties influence the interaction of bacterial cells with the substrate and its colonization is poorly understood. In this work, we tailor SU-8 nanoscale surface properties to investigate single-cell motility, adhesion, and successive colonization of phytopathogenic bacteria, .

View Article and Find Full Text PDF

This review highlights the most relevant and recent updated information available on the defense responses of selected hosts against Xanthomonas spp. Xanthomonas is one of the most important genera of Gram-negative phytopathogenic bacteria, severely affecting the productivity of economically important crops worldwide, colonizing either the vascular system or the mesophyll tissue of the host. Due to its rapid propagation, Xanthomonas poses an enormous challenge to farmers, because it is usually controlled using huge quantities of copper-based chemicals, adversely impacting the environment.

View Article and Find Full Text PDF

Type II toxin-antitoxin (TA) systems are widespread in bacteria and are involved in important cell features, such as cell growth inhibition and antimicrobial tolerance, through the induction of persister cells. Overall, these characteristics are associated with bacterial survival under stress conditions and represent a significant genetic mechanism to be explored for antibacterial molecules. We verified that even though Xylella fastidiosa and Xanthomonas citri subsp.

View Article and Find Full Text PDF

The morphological plasticity of bacteria to form filamentous cells commonly represents an adaptive strategy induced by stresses. In contrast, for diverse human and plant pathogens, filamentous cells have been recently observed during biofilm formation, but their functions and triggering mechanisms remain unclear. To experimentally identify the underlying function and hypothesized cell communication triggers of such cell morphogenesis, spatially controlled cell patterning is pivotal.

View Article and Find Full Text PDF

Huanglongbing (HLB) is currently the most devastating disease of citrus worldwide. Both bacteria ' Liberibacter asiaticus' (CLas) and ' Liberibacter americanus' (CLam) are associated with HLB in Brazil but with a strong prevalence of CLas over CLam. Conventionally, HLB management focuses on controlling the insect vector population (; also known as Asian citrus psyllid [ACP]) by spraying insecticides, an approach demonstrated to be mostly ineffective.

View Article and Find Full Text PDF

Copper-based compounds are widely used in agriculture as a chemical strategy to limit the spread of multiple plant diseases; however, the continuous use of this heavy metal has caused environmental damage as well as the development of copper-resistant strains. Thus, it is important to understand how the bacterial phytopathogens evolve to manage with this metal in the field. The MqsRA Toxin-Antitoxin system has been recently described for its function in biofilm formation and copper tolerance in , a plant-pathogen bacterium responsible for economic damage in several crops worldwide.

View Article and Find Full Text PDF

N-Acetylcysteine (NAC) is an antioxidant, anti-adhesive, and antimicrobial compound. Even though there is much information regarding the role of NAC as an antioxidant and anti-adhesive agent, little is known about its antimicrobial activity. In order to assess its mode of action in bacterial cells, we investigated the metabolic responses triggered by NAC at neutral pH.

View Article and Find Full Text PDF

subsp. () is a plant pathogenic bacterium causing citrus canker disease. The gene encodes a phosphoglucomutase/phosphomannomutase protein that is a key enzyme required for the synthesis of lipopolysaccharides and exopolysaccharides in Xanthomonads.

View Article and Find Full Text PDF

Citrus canker disease, caused by the bacterium subsp. is a constant threat to citrus-producing areas. Since it has no cure, agricultural practices to restrain its dissemination are essential to reduce the economic damage.

View Article and Find Full Text PDF

Microchannels can be used to simulate xylem vessels and investigate phytopathogen colonization under controlled conditions. In this work, we explore surface functionalization strategies for polydimethylsiloxane and glass microchannels to study microenvironment colonization by Xylella fastidiosa subsp. pauca cells.

View Article and Find Full Text PDF

Although many copper-based antimicrobial compounds have been developed to control pathogenic bacteria and fungi in plants and applied for crop protection, there is evidence that several plant pathogens have developed resistance to copper-based antimicrobial compounds, including some Xanthomonas species. Xylella is a bacterial genus belonging to the Xanthomonas family; and X. fastidiosa, which is responsible for citrus variegated chlorosis (CVC) in sweet orange, may develop resistance to one or more copper-based antimicrobials.

View Article and Find Full Text PDF

Huanglongbing (HLB), caused mainly by 'Candidatus Liberibacter asiaticus' (CLas), is the most devastating citrus disease because all commercial species are susceptible. HLB tolerance has been observed in Poncirus trifoliata and their hybrids. A wide-ranging transcriptomic analysis using contrasting genotypes regarding HLB severity was performed to identify the genetic mechanism associated with tolerance to HLB.

View Article and Find Full Text PDF

subsp. strain De Donno has been recently identified as the causal agent of a severe disease affecting olive trees in a wide area of the Apulia Region (Italy). While insights on the genetics and epidemiology of this virulent strain have been gained, its phenotypic and biological traits remained to be explored.

View Article and Find Full Text PDF

Nicotiana tabacum overexpressing CrSAMT from Citrus reticulata increased production of MeSA, which works as an airborne signal in neighboring wild-type plants, inducing PR1 and increasing resistance to the pathogen Xylella fastidiosa. Xylella fastidiosa is one of the major threats to plant health worldwide, affecting yield in many crops. Despite many efforts, the development of highly productive resistant varieties has been challenging.

View Article and Find Full Text PDF

Due to their reduced metabolism, persister cells can survive most antimicrobial treatments, which usually rely on corrupting active biochemical pathways. Therefore, molecules that kill bacterial persisters should function in a metabolism-independent manner. Some anti-persister compounds have been found previously, such as the DNA-crosslinkers mitomycin C and cisplatin, but more effective and lower cost alternatives are needed.

View Article and Find Full Text PDF