The development of drug-resistant microorganisms has become a critical issue for modern medicine and drug discovery and development with severe socio-economic and ecological implications. Since standard and conventional treatment options are generally inefficient, leading to infection persistence and spreading, novel strategies are fundamentally necessary in order to avoid serious global health problems. In this regard, both metal and metal oxide nanoparticles (NPs) demonstrated increased effectiveness as nanobiocides due to intrinsic antimicrobial properties and as nanocarriers for antimicrobial drugs. Among them, gold, silver, copper, zinc oxide, titanium oxide, magnesium oxide, and iron oxide NPs are the most preferred, owing to their proven antimicrobial mechanisms and bio/cytocompatibility. Furthermore, inorganic NPs can be incorporated or attached to organic/inorganic films, thus broadening their application within implant or catheter coatings and wound dressings. In this context, this paper aims to provide an up-to-date overview of the most recent studies investigating inorganic NPs and their integration into composite films designed for antimicrobial therapies.

https://www.mdpi.com/1422-0067/22/9/4595/pdf

Inorganic Nanoparticles and Composite Films for Antimicrobial Therapies.

Helicobacter pylori infection and gastric carcinoma.

The unique extracellular electron transfer (EET) ability has positioned electroactive bacteria (EAB) as a major class of cellular chassis for genetic engineering aimed at favorable environmental, energy, and geoscience applications. However, previous efforts to genetically enhance EET ability have often impaired the basal metabolism and cellular growth due to the competition for the limited cellular resource. Here, we design a quorum sensing-based population-state decision (PSD) system for intelligently reprogramming the EET regulation system, which allows the rebalanced allocation of the cellular resource upon the bacterial growth state. We demonstrate that the electron output from Shewanella oneidensis MR-1 could be greatly enhanced by the PSD system via shifting the dominant metabolic flux from initial bacterial growth to subsequent EET enhancement (i.e., after reaching a certain population-state threshold). The strain engineered with this system achieved up to 4.8-fold EET enhancement and exhibited a substantially improved pollutant reduction ability, increasing the reduction efficiencies of methyl orange and hexavalent chromium by 18.8- and 5.5-fold, respectively. Moreover, the PSD system outcompeted the constant expression system in managing EET enhancement, resulting in considerably enhanced electron output and pollutant bioreduction capability. The PSD system provides a powerful tool for intelligently managing extracellular electron transfer and may inspire the development of new-generation smart bioelectrical devices for various applications.

https://www.pnas.org/content/pnas/117/37/23001.full.pdf

Developing a population-state decision system for intelligently reprogramming extracellular electron transfer in Shewanella oneidensis

Objective

Helicobacter pylori (Hp) has a dominan role in gastroduodenale diseases i.e chronic active gastritis peptic ulcer and gastric cancer. The prevalence of gastric cancer in Indonesia from upper GI endoscopy examinations was 1.33-4.2%. The prevalence of Hp infection in gastric cancer worlwide is between 52 - 94%. Hp infection may lead chronic active gastritis to be dysplasia and then carcinoma. The aim of this study is to find the prevalence of Hp infection in gastric cancer, the relation between Hp and gastric cancer.



Material & Methods

The gastric cancer cases who were treated in Ciptomangunkusumo hospital and Abdiwaluyo hospital in 2 years (1998-1999) were included in this study. As control we included chronic gastritis cases in the same years and same hospital. All of the patients were done endoscopical examination, mucosal biopsy for pathological examination or CLO test and serum Hp serology examination (IgG Helicobacter pylori). Hp infection was thought to be positive if minimally the pathological examination positive or both of CLO test & Hp serology positive. Exclusion if incomplete data, the patient refused to follow the study. Statistic chi-square test or fisher test.



Result

We got 21 cases of gastric cancer and 78 cases of chronic gastritis. The most frequent characteristic of gastric cancer patients was age group 50-59 yo(38.09%), male(80.95%), batak ethnic(38.09%), blood A group (50%). The symptom of the patients were upper GI bleeding (42.85%), abdominal mass (66.66%). Hp was positive in 17/21(80.95%) of gastric cancer patients and 17/78(21.79%) of chronic gastritis patients, respectively (p=0.000001).



Hp

positive in adenocarcinoma (52.38%), signet ring cell carcinoma (19.04%), carcinoid tumor (4.76%) & malt lymphoma (4.76%).



Conclusion

Hp infection is very frequent in gastric cancer.

Helicobacter pylori in gastric cancer

In recent years, the use of bacteriophages (or 'phages') against multidrug-resistant (MDR) bacteria including Pseudomonas aeruginosa has drawn considerable attention, globally. In this work, we report the isolation and detailed characterization of a highly lytic Pseudomonasphage DRL-P1 isolated from wastewater. Under TEM, DRL-P1 appeared as a member of the phage family Myoviridae. DRL-P1 featured rapid adsorption (~ 5 min), short-latency (~ 30 min), and large burst size (~ 100 PFU per infected cell). DRL-P1 can withstand a wide temperature range (4 °C to 40 °C) and pH (5.0 to 10.0) conditions. The 66,243 bp DRL-P1 genome (MN564818) encodes at least 93 ORFs, of which 36 were functionally annotated based on homology with similar phage proteins available in the databases. Comparative analyses of related genomes suggest an independent evolutionary history and discrete taxonomic position of DRL-P1 within genus Pbunavirus. No toxin or antibiotic resistance genes was identified. DRL-P1 is tolerant to lyophilization and encapsulation techniques and retained lytic activity even after 18 months of storage. We also demonstrated decontaminating potentials of DRL-P1 in vitro, on an artificially contaminated cover-slip model. To the best of our knowledge, this is the first Pbunavirus to be reported from India. Our study suggests DRL-P1 as a potential candidate for various applications.

/pdf/isolation-and-characterization-of-a-lytic-bacteriophage-2npaahiwp4.pdf

Isolation and characterization of a lytic bacteriophage against Pseudomonas aeruginosa.

Restoration of dysbiotic human gut microbiome for homeostasis

Polyamines are positively charged hydrocarbons that are essential for the growth and cellular maintenance in prokaryotes and eukaryotes. Polyamines have been demonstrated to play a role in bacterial pathogenicity and biofilm formation. However, the role of extracellular polyamines as a signaling molecule in the regulation of virulence is not investigated in detail. The bacterial pathogens residing in the respiratory tract remain asymptomatic for an extended period; however, the factors that lead to symptomatic behavior are poorly understood. Further investigation to understand the relation between the host-secreted factors and virulence of pathogenic bacteria in the respiratory tract may provide insights into the pathogenesis of respiratory tract infections. Polyamines produced within the bacterial cell are generally sequestered. Therefore, the pool of extracellular polyamines formed by secretion of the commensals and the host may be one of the signaling molecules that might contribute toward the alterations in the expression of virulence factors in bacterial pathogens. Besides, convergent mechanisms of polyamine biosynthesis do exist across the border of species and genus level. Also, several novel polyamine transporters in the host and bacteria remain yet to be identified. The review focuses on the role of polyamines in the expression of virulence phenotypes and biofilm formation of the respiratory tract pathogens.

Polyamines in the virulence of bacterial pathogens of respiratory tract.

Bacteria live in a polymicrobial community where it interacts with biotic and abiotic factors using specific signalling molecules. Acyl homoserine lactones, autoinducing peptides, bacteriocins and polyamines are a few signals documented for interspecies signalling. The signalling system could be used for a coordinated behaviour categorised as Quorum sensing (QS). QS is a term used to define a cell - cell communication process amongst bacteria that helps to gather cell density information and regulate gene expression accordingly. QS had been demonstrated to play a pivotal role in bacterial pathogenesis by regulating the expression of different virulence factors affecting adhesion, invasion and survival within a tissue. In the current review, we discuss the role of interspecies bacterial communication in pathogenicity. The molecules involved in the interspecies bacterial communication affecting virulence factors required for the establishment of infection have been discussed in detail to gain an insight for development of strategies that can be proposed to combat bacterial infections by attenuating their communication systems. The knowledge on the role of interspecies bacterial communication on virulence will assist in understanding the factors affecting symptomatic and asymptomatic infections.

Role of interspecies bacterial communication in the virulence of pathogenic bacteria.

The quest to combat bacterial infections has dreaded humankind for centuries. Infections involving ESKAPE (Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, ...

Bacteriophages for ESKAPE: role in pathogenicity and measures of control.

The factors that determine the outcomes of host-pathogen interactions, such as host specificity, tissue specificity, and transition from asymptomatic to symptomatic behavior of a pathogen, are yet to be deciphered The initial interaction of a pathogen with host and host-associated factors play a crucial role in deciding such outcomes One of the several host-factors that contribute to bacterial adhesion and the outcome of an infection is the activation of early growth response 1 (EGR1) EGR1 is an initial response transcriptional regulator that plays a vital role in regulating cell growth, differentiation, and survival EGR1 expression is seen in most of the mammalian tissues Multiple post-translational modifications occur, which modulate the EGR1 transcriptional activity Upon activation, EGR1 can transactivate several genes with diverse cellular functions, including transcriptional regulatory proteins and cell proliferation EGR1 has also been identified as a potential mediator of inflammatory gene expression Recent studies have highlighted the role of EGR1 as a potent signaling molecule that facilitates bacterial adhesion to host epithelial cells, thus modulating colonization pathways The pathways for the regulation of EGR1 during host-pathogen interaction remain yet unidentified The review focuses on the role and regulation of EGR1 during host-pathogen interaction

Sunil D Saroj

Papers

Restoration of dysbiotic human gut microbiome for homeostasis

Polyamines in the virulence of bacterial pathogens of respiratory tract.

Role of interspecies bacterial communication in the virulence of pathogenic bacteria.

Bacteriophages for ESKAPE: role in pathogenicity and measures of control.

Early growth response 1 (EGR1) activation in initial stages of host-pathogen interactions.