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Molybdenum sulfide (MoS2) and modified MoS2 with different percentages of CdS (10%, 30%, and 50% CdS@MoS2) were successfully synthesized and characterized. The photocatalytic performance of the MoS2 and CdS@MoS2 was evaluated by degrading brilliant green (BG), methylene blue (MB), and rhodamine B (RhB) dyes under visible light irradiation. Amongst the synthesized photocatalysts, 50% CdS@MoS2 exhibited the highest photocatalytic activity, degrading 97.6%, 90.3%, and 75.5% of BG, MB, and RhB dyes, respectively within 5 h. The active species involved in the degradation processes were investigated. All trapping agents inhibited BG and MB degradation to a similar extent, indicating that all of the probed active species play an important role in the degradation of BG and MB. In contrast, h+ and O2•− were found to be the main reactive species in the photocatalytic RhB degradation. A potential mechanism for the photocatalytic degradation of dyes using CdS@MoS2 has been proposed. This work highlights the potential of CdS@MoS2 as a photocatalyst for more efficient water remediation applications. [ABSTRACT FROM AUTHOR]

Gadolinium hydroxide (Gd(OH)3) was synthesized via a microwave-assisted synthesis method. Nickel ion (Ni2+) was doped into Gd(OH)3, in which 4–12% Ni-Gd(OH)3 was synthesized, to study the effect of doping. The structural, optical, and morphological properties of the synthesized materials were analyzed. The crystallite sizes of the hexagonal structure of Gd(OH)3 and Ni-Gd(OH)3, which were 17–30 nm, were obtained from x-ray diffraction analysis. The vibrational modes of Gd(OH)3 and Ni-Gd(OH)3 were confirmed using Raman and Fourier-transform infrared spectroscopies. The band gap energy was greatly influenced by Ni-doping, in which a reduction of the band gap energy from 5.00 to 3.03 eV was observed. Transmission electron microscopy images showed nanorods of Gd(OH)3 and Ni-Gd(OH)3 and the particle size increased upon doping with Ni2+. Photocatalytic degradations of brilliant green (BG) and 4-nitrophenol (4-NP) under UV light irradiation were carried out. In both experiments, 12% Ni-Gd(OH)3 showed the highest photocatalytic response in degrading BG and 4-NP, which is about 92% and 69%, respectively. Therefore, this study shows that Ni-Gd(OH)3 has the potential to degrade organic pollutants. [ABSTRACT FROM AUTHOR]

The rapidly rising antimicrobial resistance (AMR) in pathogenic bacteria has become one of the most serious public health challenges, with a high death rate. Most pathogenic bacteria have been recognized as a source of AMR and a primary barrier to antimicrobial treatment failure due to the development of biofilms and the production of virulence factors. In this work, nanotechnology was employed as a substitute method to control the formation of biofilms and attenuate virulence features in Pseudomonas aeruginosa and Staphylococcus aureus. We synthesized biocompatible gold nanoparticles from marine-derived laminarin as potential biofilm and virulence treatments. Laminarin-gold nanoparticles (Lam-AuNPs) have been identified as spherical, 49.84 ± 7.32 nm in size and − 26.49 ± 1.29 mV zeta potential. The MIC value of Lam-AuNPs against several drug-resistant microbial pathogens varied from 2 to 1024 μg/mL in both standard and host-mimicking media. Sub-MIC values of Lam-AuNPs were reported to effectively reduce the production of P. aeruginosa and S. aureus biofilms in both standard and host-mimicking growth media. Furthermore, the sub-MIC of Lam-AuNPs strongly reduced hemolysis, pyocyanin, pyoverdine, protease, and several forms of flagellar and pili-mediated motility in P. aeruginosa. Lam-AuNPs also inhibited S. aureus hemolysis and the production of amyloid fibrils. The Lam-AuNPs strongly dispersed the preformed mature biofilm of these pathogens in a dose-dependent manner. The Lam-AuNPs would be considered an alternative antibiofilm and antivirulence agent to control P. aeruginosa and S. aureus infections. Key points: • Lam-AuNPs were biosynthesized to control biofilm and virulence. • Lam-AuNPs show effective biofilm inhibition in standard and host-mimicking media. • Lam-AuNPs suppress various virulence factors of P. aeruginosa and S. aureus. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii is a Gram-negative opportunistic zoonotic pathogenic bacterium that causes nosocomial infections ranging from minor to life-threatening. The clinical importance of this zoonotic pathogen is rapidly increasing due to the development of multiple resistance mechanisms and the synthesis of numerous virulence factors. Although no flagellum-mediated motility exists, it may move through twitching or surface-associated motility. Twitching motility is a coordinated multicellular movement caused by the extension, attachment, and retraction of type IV pili, which are involved in surface adherence and biofilm formation. Surface-associated motility is a kind of movement that does not need appendages and is most likely driven by the release of extra polymeric molecules. This kind of motility is linked to the production of 1,3-diaminopropane, lipooligosaccharide formation, natural competence, and efflux pump proteins. Since A. baumannii’s virulence qualities are directly tied to motility, it is possible that its motility may be used as a specialized preventative or therapeutic measure. The current review detailed the signaling mechanism and involvement of various proteins in controlling A. baumannii motility. As a result, we have thoroughly addressed the role of natural and synthetic compounds that impede A. baumannii motility, as well as the underlying action mechanisms. Understanding the regulatory mechanisms behind A. baumannii’s motility features will aid in the development of therapeutic drugs to control its infection. Key points: • Acinetobacter baumannii exhibits multiple resistance mechanisms. • A. baumannii can move owing to twitching and surface-associated motility. • Natural and synthetic compounds can attenuate A. baumannii motility. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii is a Gram-negative opportunistic zoonotic pathogenic bacterium that causes nosocomial infections ranging from minor to life-threatening. The clinical importance of this zoonotic pathogen is rapidly increasing due to the development of multiple resistance mechanisms and the synthesis of numerous virulence factors. Although no flagellum-mediated motility exists, it may move through twitching or surface-associated motility. Twitching motility is a coordinated multicellular movement caused by the extension, attachment, and retraction of type IV pili, which are involved in surface adherence and biofilm formation. Surface-associated motility is a kind of movement that does not need appendages and is most likely driven by the release of extra polymeric molecules. This kind of motility is linked to the production of 1,3-diaminopropane, lipooligosaccharide formation, natural competence, and efflux pump proteins. Since A. baumannii's virulence qualities are directly tied to motility, it is possible that its motility may be used as a specialized preventative or therapeutic measure. The current review detailed the signaling mechanism and involvement of various proteins in controlling A. baumannii motility. As a result, we have thoroughly addressed the role of natural and synthetic compounds that impede A. baumannii motility, as well as the underlying action mechanisms. Understanding the regulatory mechanisms behind A. baumannii's motility features will aid in the development of therapeutic drugs to control its infection. Key points: • Acinetobacter baumannii exhibits multiple resistance mechanisms. • A. baumannii can move owing to twitching and surface-associated motility. • Natural and synthetic compounds can attenuate A. baumannii motility. [ABSTRACT FROM AUTHOR]

Pseudmonas aeruginosa is a Gram-negative bacterium known to be ubiquitous and recognized as one of the leading causes of infections such as respiratory, urinary tract, burns, cystic fibrosis, and in immunocompromised individuals. Failure of antimicrobial therapy has been documented to be attributable due to the development of various resistance mechanisms, with a proclivity to develop additional resistance mechanisms rapidly. P. aeruginosa virulence attenuation is an alternate technique for disrupting pathogenesis without impacting growth. The iron-scavenging siderophores (pyoverdine and pyochelin) generated by P. aeruginosa have various properties like scavenging iron, biofilm formation, quorum sensing, increasing virulence, and toxicity to the host. As a result, developing an antivirulence strategy, specifically inhibiting the P. aeruginosa siderophore, has been a promising therapeutic option to limit their infection. Several natural, synthetic compounds and nanoparticles have been identified as potent inhibitors of siderophore production/biosynthesis, function, and transport system. The current review discussed pyoverdine and pyochelin's synthesis and transport system in P. aeruginosa. Furthermore, it is also focused on the role of several natural and synthetic compounds in reducing P. aeruginosa virulence by inhibiting siderophore synthesis, function, and transport. The underlying mechanism involved in inhibiting the siderophore by natural and synthetic compounds has also been explained. Key points: • Pseudomonas aeruginosa is an opportunistic pathogen linked to chronic respiratory, urinary tract, and burns infections, as well as cystic fibrosis and immunocompromised patients. • P. aeruginosa produces two virulent siderophores forms: pyoverdine and pyochelin, which help it to survive in iron-deficient environments. • The inhibition of siderophore production, transport, and activity using natural and synthesized drugs has been described as a potential strategy for controlling P. aeruginosa infection. [ABSTRACT FROM AUTHOR]

In a human host, bacterial Staphylococcus aureus and fungal Candida albicans pathogens form a mixed biofilm that causes severe mortality and morbidity. However, research on the formation and eradication of mixed biofilms under dynamic conditions is lacking. Thus, this study employed a microfluidic technique to analyze the real-time formation of mono- and dual-species (S. aureus and C. albicans) biofilms and noninvasive optical treatment of the established mature biofilm using 405-nm laser light. A herringbone mixer thoroughly mixed both bacterial and fungal cells in the growth media before being injected into the observation channels on the microfluidic chip. At a flow rate of 1.0 µL/min of growth media for 24 h, the bacterial biofilm coverage was up to 15% higher than that of the fungal biofilm (50% for bacteria vs. 35% for fungus). On the other hand, the dual-species biofilm yielded the highest coverage of ~ 96.5% because of the collective interaction between S. aureus and C. albicans. The number of cell proliferation events in S. aureus was higher than that of C. albicans for 12 h, which indicates that the S. aureus biofilm was developed faster than C. albicans. The novel in situ test platform showed a significant bactericidal effect (80%) of the 405-nm laser light at 1080 J/cm2 towards the established S. aureus biofilm, whereas the same treatment removed approximately 69% of the mixed cells in the dual-species biofilm. This study revealed that the developed microfluidic platform could be utilized to monitor the formation of dual-species biofilms in real-time and laser-induced antimicrobial effects on dual-species biofilms. [ABSTRACT FROM AUTHOR]

Several studies have demonstrated that when exposed to physical, chemical, and biological stresses in the environment, many bacteria (Gram-positive and Gram-negative) change their morphology from a normal cell to a filamentous shape. The formation of filamentous morphology is one of the survival strategies against environmental stress and protection against phagocytosis or protist predators. Numerous pathogenic bacteria have shown filamentous morphologies when examined in vivo or in vitro. During infection, certain pathogenic bacteria adopt a filamentous shape inside the cell to avoid phagocytosis by immune cells. Filamentous morphology has also been seen in biofilms formed on biotic or abiotic surfaces by certain bacteria. As a result, in addition to protecting against phagocytosis by immune cells or predators, the filamentous shape aids in biofilm adhesion or colonization to biotic or abiotic surfaces. Furthermore, these filamentous morphologies of bacterial pathogens lead to antimicrobial drug resistance. Clinically, filamentous morphology has become one of the most serious challenges in treating bacterial infection. The current review went into great detail about the various factors involved in the change of filamentous morphology and the underlying mechanisms. In addition, the review discussed a control strategy for suppressing filamentous morphology in order to combat bacterial infections. Understanding the mechanism underlying the filamentous morphology induced by various environmental conditions will aid in drug development and lessen the virulence of bacterial pathogens. Key points: • The bacterial filamentation morphology is one of the survival mechanisms against several environmental stress conditions and protection from phagocytosis by host cells and protist predators. • The filamentous morphologies in bacterial pathogens contribute to enhanced biofilm formation, which develops resistance properties against antimicrobial drugs. • Filamentous morphology has become one of the major hurdles in treating bacterial infection, hence controlling strategies employed for inhibiting the filamentation morphology from combating bacterial infections. [ABSTRACT FROM AUTHOR]

Synthesized cerium oxide nanoparticles (S-CeO2 NPs) and 1%, 5% and 10% zirconium doped CeO2 (Zr-doped CeO2) NPs were fabricated using aqueous leaf extract of Pometia pinnata. The synthesized NPs were characterized using standard techniques which confirmed successful synthesis of NPs with particle size ranging from 12 to 23 nm and band gap energy of 2.54–2.66 eV. Photoantioxidant activities showed enhanced activities under visible light irradiation in comparison to the dark condition in the dose-dependent study. Biofilm inhibition studies showed ~ 73% biofilm inhibition of Staphylococcus aureus at 512 µg/mL for S-CeO2, whereas 10% Zr-doped CeO2 NPs showed biofilm inhibition of 52.7%. The bactericidal tests showed killing properties at 1024 µg/mL of S-CeO2 NPs and at 512 µg/mL of 1% Zr-doped CeO2. Reduced bactericidal activities were observed for 5% and 10% Zr-doped CeO2. These studies showed that the fabricated NPs have both good photoantioxidant and antibacterial properties. [ABSTRACT FROM AUTHOR]

Vibrio cholerae and Vibrio vulnificus are critical foodborne pathogens that need to be intensively controlled for their infection due to the intake and distribution of seafood, especially raw oysters. For this reason, various methods have already been developed for the detection and enumeration of these bacteria. The most probable number (MPN)-PCR (polymerase chain reaction) method is commonly used with the selective-differential medium for the efficiency and convenience of cell enumeration. One of the most frequently used for detecting Vibrio spp. is thiosulfate-citrate-bile salts-sucrose (TCBS) agar. But this selective-differential medium can fail to distinguish between V. cholerae, V. vulnificus, and Vibrio alginolyticus. For this reason, the conventional MPN-PCR method with TCBS medium for the detection of Vibrio spp. has a problem with processing PCR two times. This study suggests a simple and minimized detection method using one-time PCR and non-NaCl Luria–Bertani (LB-0) medium culture. This detection method is based on the difference in salt requirement between V. cholerae and V. vulnificus. Employing the developed methodology, the simultaneous cell enumeration of V. cholerae and V. vulnificus can be possible at a low cost. Furthermore, this study proposes a new specific primer to detect virulence-related genes from V. cholerae and V. vulnificus. This advanced MPN-PCR method was verified using bioaccumulated pacific oysters (Crassostrea gigas) by V. cholerae and V. vulnificus. [ABSTRACT FROM AUTHOR]

The formation of biofilms by bacterial pathogens and the presence of persister cells in biofilms have become major concerns in the health sector, owing to their antibiotic resistance and tolerance. The transformation of bacterial pathogens into persister cells, either stochastically or due to stressful environmental factors, results in recalcitrant and recurring infections. Here, we sought to prepare gold nanoparticles from naturally occurring caffeine and explore their inhibitory action against biofilm formation and persister cells. Fourier transform infrared spectroscopy, UV-visible absorption spectroscopy, field emission transmission electron microscopy, energy-dispersive X-ray diffraction, and dynamic light scattering were used to characterize the gold nanoparticles obtained from caffeine (Caff-AuNPs). The Caff-AuNPs were found to exhibit a number of properties, including the ability to prevent biofilm formation, disperse mature biofilms, and kill different types of persister of gram-positive (Staphylococcus aureus and Listeria monocytogenes) and gram-negative (Pseudomonas aeruginosa and Escherichia coli) pathogenic bacteria. Microscopic analysis of the aforementioned bacterial cells, treated with Caff-AuNPs, revealed the bactericidal effect of Caff-AuNPs, although the underlying mechanism remains unknown. Collectively, the Caff-AuNPs synthesized in this study may be used as potential drugs to combat chronic infections caused by biofilm-forming pathogenic bacteria. Key points: • Biofilm and persister cells are clinically relevant, as they either prolong or completely resist antibiotic treatments. • Caffeine is used in the green synthesis of Caff-AuNPs, which have antibacterial and antibiofilm properties. • Caff-AuNPs are effective against various pathogenic bacterial persister cells. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the efficacy of a depuration system equipped with UV-irradiation to control Vibrio vulnificus infection such as septicemia (or sepsis) using alive oysters. After 6 h of bioaccumulation of V. vulnificus, Pacific oyster Crassostrea gigas were found to be contaminated by > 8.0 log MPN/g of V. vulnificus cells. After 60 h of depuration, the V. vulnificus cell number significantly decreased to < 4.0 log MPN/g. The present depuration process meets the standard effectiveness in reducing V. vulnificus cells by > 3.52 log and < 30 MPN/g as recommended by the National Shellfish Sanitization Procedure Molluscan Shellfish Control guidelines. Furthermore, no significant changes in pH value and glycogen content indicate that the depuration process did not affect the freshness and quality of the oyster samples. The present study could help control any potential infection associated with the consumption of raw oysters without losing their quality. [ABSTRACT FROM AUTHOR]

Indwelling urinary catheterization is one of the major causes of urinary tract infection (UTI) in hospitalized patients worldwide. A catheter serves as a surface for the colonization and formation of biofilm by UTI-related pathogenic bacteria. To combat the biofilm formation on its surface, several strategies have already been employed such as coating it with antibiofilm and antimicrobial compounds. For instance, the application of lactic acid bacteria (LAB) offers a potential strategy for the treatment of biofilm formation on the surface of the urinary catheter due to its ability to kill the pathogenic bacteria. The killing of pathogenic bacteria by LAB occurs via the production of antimicrobial compounds such as lactic acid, bacteriocin, and hydrogen peroxide. LAB also displays a competitive exclusion mechanism to prevent the adhesion of pathogens on the surfaces. Hence, LAB has been extensively applied as a bacteriotherapy to combat infectious diseases. Several strategies have been employed to attach LAB to a surface, but its easy detachment during long time exposure becomes one of the drawbacks in its application. Here, we have proposed a novel strategy for its adhesion on the surface of the urinary catheter with the utilization of mannose-specific adhesin (Msa) protein in a way similar as uropathogenic bacteria interacts between Msa present on the tip of the type I fimbriae/pilus and the mannose moieties on the host epithelial cell surfaces. Key points: • Urinary tract infection (UTI) is one of the common hospital–acquired infections, which is associated with the application of an indwelling urinary catheter. • Based on the competitive exclusions properties of LAB, attachment of the LAB on the catheter surface would be a promising approach to control the formation of pathogenic biofilm. • The strategy employed for the adhesion of LAB is via a covalent interaction of its mannose-specific adhesin (Msa) protein to the mannose residues grafted on the catheter surface. [ABSTRACT FROM AUTHOR]

Flagellar motility in bacteria is a highly regulated and complex cellular process that requires high energy investment for movement and host colonization. Motility plays an important role in the lifestyle of Vibrio spp. in the aquatic environment and during host colonization. Flagellar motility in vibrios is associated with several cellular processes, such as movement, colonization, adhesion, biofilm formation, and virulence. The transcription of all flagella-related genes occurs hierarchically and is regulated positively or negatively by several transcription factors and regulatory proteins. The flagellar regulatory hierarchy is well studied in Vibrio cholerae and Vibrio parahaemolyticus. Here, we compared the regulatory cascade and molecules involved in the flagellar motility of V. cholerae and V. parahaemolyticus in detail. The evolutionary relatedness of the master regulator of the polar and lateral flagella in different Vibrio species is also discussed. Although they can form symbiotic associations of some Vibrio species with humans and aquatic organisms can be harmed by several species of Vibrio as a result of surface contact, characterized by flagellar movement. Thus, targeting flagellar motility in pathogenic Vibrio species is considered a promising approach to control Vibrio infections. This approach, along with the strategies for controlling flagellar motility in different species of Vibrio using naturally derived and chemically synthesized compounds, is discussed in this review. Key points: • Vibrio species are ubiquitous and distributed across the aquatic environments. • The flagellar motility is responsible for the chemotactic movement and initial colonization to the host. • The transition from the motile into the biofilm stage is one of the crucial events in the infection. • Several signaling pathways are involved in the motility and formation of biofilm. • Attenuation of motility by naturally derived or chemically synthesized compounds could be a potential treatment for preventing Vibrio biofilm-associated infections. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the vaccine-matching and antigenic properties of foot-and-mouth disease virus (FMDV) isolates collected from Ethiopia between 2011 and 2014. Samples (n = 51) were collected from cattle and pigs with clinical signs consistent with foot-and-mouth disease (FMD) on farms in Debre-Berhan, Debre-Zeit/Bishoftu, Sidamo, Mekelle, and Addis Ababa. Infectious FMDV was isolated using BHK-21 cell cultures from 38 of the 51 field samples (74.5%). All of these FMDV-positive samples were characterized as serotype O, belonging to two East Africa topotypes (EA-3 and EA-4), and their VP1-encoding sequences demonstrated amino acid sequence variability encompassing 27 positions in comparison to the vaccine strain (O/ETH/38/2005) currently provided by the National Veterinary Institute of Ethiopia. One-dimensional virus neutralization test (1 dm VNT) results showed that O/ETH/38/2005 was antigenically matched to 10 of the 16 serotype O viruses. These findings indicate that the O/ETH/38/2005 vaccine strain can provide protection against outbreaks caused by the O/EA-3 topotype, although poorer vaccine-matching results for the O/EA-4 topotype reinforce the importance of using a good-quality vaccine with high coverage in the susceptible herds with supporting post-vaccination serosurveillance to ensure that sufficient antibody titers are generated in the vaccinated animals. [ABSTRACT FROM AUTHOR]

Aminoglycosides are one of the common classes of antibiotics that have been widely used for treating infections caused by pathogenic bacteria. The mechanism of bactericidal action by aminoglycosides is well-known, by which it terminates the cytoplasmic protein synthesis. However, the potentials of aminoglycosides become hindered when facing the evolution of bacterial resistance mechanisms. Among multiple resistance mechanisms displayed by bacteria against antibiotics, the formation of biofilm is the mechanism that provides a barrier for antibiotics to reach the cellular level. Bacteria present in the biofilm also get protection against the impact of host immune responses, harsh environmental conditions, and other antimicrobial treatments. Hence, with the multifaceted resistance developed by biofilm-forming pathogenic bacteria, antibiotics are therefore discontinued for further applications. However, the recent research developed several alternative strategies such as optimization of the active concentration, modification of the environmental conditions, modification of the chemical structure, combinatorial application with other active agents, and formulation with biocompatible carrier materials to revitalize and exploit the new potential of aminoglycosides. The present review article describes the above mentioned multiple approaches and possible mechanisms for the application of aminoglycosides to treat biofilm-associated infections. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is known as an opportunistic pathogen whose one of the antibiotic resistance mechanisms includes biofilm formation and virulence factor production. The present study showed that the sub-minimum inhibitory concentration (sub-MIC) of streptomycin inhibited the formation of biofilm and eradicated the established mature biofilm. Streptomycin at sub-MIC was also capable of inhibiting biofilm formation on the urinary catheters. In addition, the sub-MIC of streptomycin attenuated the bacterial virulence properties as confirmed by both phenotypic and gene expression studies. The optimal conditions for streptomycin to perform anti-biofilm and anti-virulence activities were proposed as alkaline TSB media (pH 7.9) at 35 °C. However, sub-MIC of streptomycin also exhibited a comparative anti-biofilm efficacy in LB media at similar pH level and temperature. Furthermore, this condition also improved the biofilm inhibition and eradication properties of streptomycin, tobramycin and tetracycline towards the biofilm formed by a clinical isolate of P. aeruginosa. Findings from the present study provide an important insight for further studies on the mechanisms of biofilm inhibition and dispersion of pre-existing biofilm by streptomycin as well as tobramycin and tetracycline under a specific culture environment. [ABSTRACT FROM AUTHOR]

Chronic infections caused by Pseudomonas aeruginosa have been a major concern as their spread and mortality continue to be on the rise. These infections are majorly attributed to biofilm formation via sequential steps where motility plays an essential role in initial attachment of bacterial cells onto biotic and abiotic surfaces, thereby contributing to multi-drug resistance among pathogens. Therefore, attenuating motility properties can be considered as highly potential for controlling P. aeruginosa biofilm formation. This strategy has employed the use of various natural and chemically synthesized compounds. The present review article explained the importance and regulation of different types of motilities properties. Furthermore, it also covered several important alternative approaches using anti-motility agents which could be helpful for controlling P. aeruginosa biofilm-associated infections. Further studies are required for in-depth understandings about the mechanisms of motilities controlling of these molecules at molecular levels. [ABSTRACT FROM AUTHOR]

There are growing demands for the synthesis of silver nanoparticles (AgNPs) using green technology approaches due to their cost-effective and eco-friendly nature. Although, there are considerable number of research reports available related to biological means such as using plants, fungi, and bacteria-assisted synthesis of silver nanoparticles. In recent trends, synthesis of AgNPs using bacteria is considered most attractive, simple, green, and cost-effective source(s). This leads to the increase in the number of reports on AgNPs synthesized by different bacterial genera (both gram-positive and gram-negative) and species. The present review article describes the diversity of bacteria (both gram-positive and gram-negative) capable of synthesizing AgNPs and possible applications of AgNPs. Thus, increasing the number of bacteria for the synthesis of AgNPs will be helpful to combat pathogenic bacteria and will open doors for novel avenues and applications. [ABSTRACT FROM AUTHOR]

Enterohemorrhagic Escherichia coli ( E. coli) O157:H7, a gram-negative bacteria identified as a foodborne pathogen causing severe disease is of great concern worldwide. The pathogenicity of E. coli O157:H7 is due to the presence of some virulence factors and its ability to form biofilm which resist antimicrobial compounds, withstand harsh environmental condition and protects from the host immune responses. Formation of biofilm is a multistep process such as adhesion, cellular aggregation and productions of extracellular matrix in which colonies are embedded. There are high numbers of research in the discovery of natural and synthetic compounds which can attenuate the E. coli O157:H7 biofilm formation as well as suppress virulence-related genes. The present review article focuses on the steps involved in E. coli O157:H7 biofilm formation, factors associated with virulence and attenuation. [ABSTRACT FROM AUTHOR]

Arthrobacter protophormiae RKJ100 was previously characterized for its ability to tolerate extremely high concentrations of o-nitrobenzoate (ONB), a toxic xenobiotic environmental pollutant. The physiological responses of strain RKJ100 to ≥30 mM ONB indicated towards a resistance mechanism manifested via alteration of cell morphology and cell wall structure. In this study, we aim to characterize gene(s) involved in the resistance of strain RKJ100 towards extreme concentrations (i.e. 150 mM) of ONB. Transposon mutagenesis was carried out to generate a mutant library of strain RKJ100, which was then screened for ONB-sensitive mutants. A sensitive mutant was defined and selected as one that could not tolerate ≥30 mM ONB. Molecular and biochemical characterization of this mutant showed that the disruption of endo-β- N-acetylglucosaminidase (ENGase) gene caused the sensitivity. ENGase is an important enzyme for oligosaccharide processing and cell wall recycling in bacteria, fungi, plants and animals. Previous reports have already indicated several possible roles of this enzyme in cellular homeostasis. Results presented here provide the first evidence for its involvement in bacterial resistance towards extreme concentrations of a toxic xenobiotic compound and also suggest that strain RKJ100 employs ENGase as an important component in osmotic shock response for resisting extreme concentrations of ONB. [ABSTRACT FROM AUTHOR]

Strain L15, a Gram-negative, motile, orange colored bacterium was isolated from pond soil in the surrounding area of a hexachlorocyclohexane (HCH) dump site at Ummari village in Lucknow, India. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain L15 belongs to the family Hyphomicrobiaceae in the order Rhizobiales. Strain L15 showed highest 16S rRNA gene sequence similarity to Devosia chinhatensis IPL18 (98.0%). Chemotaxonomic data revealed that the major fatty acids were summed feature 8 (C ω7 c and/or C ω6 c), C ω7 c 11-methyl, C and C. The major polar lipids of strain L15 were diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G+C content of strain L15 was 59.8%. Polyamine profile showed the presence of sym-homospermidine with traces of putrescine. Ubiquinone Q-10 was the major respiratory quinone present. Based on these data, strain L15 (=CCM 7977 =DSM 25398) was classified as a type strain of a novel species, for which the name Devosia lucknowensis sp. nov. is proposed. [ABSTRACT FROM AUTHOR]

A Gram-positive, pinkish-orange pigmented, coccoid strain, FCS-11 was isolated from a marine sediment sample taken from Kochi fort area, Kerala, India and subjected to polyphasic taxonomic study. The 16S rRNA gene sequence of the strain was determined and the results of 16S rRNA gene sequence analysis showed that the strain FCS-11 should be assigned to the genus Kocuria. The chemotaxonomic data supported this taxonomic placement i.e. menaquinones MK-7(H), MK-8(H) and MK-9(H); major fatty acids anteiso C15:0 and iso-C15:0 and phosphatidylglycerol (PG) and diphosphatidylglycerol (DPG) as major polar lipids. Further phylogenetic analysis of the 16S rRNA gene sequence confirmed that the strain FCS-11 belonged to the genus Kocuria and is closely related to Kocuria turfanensis MTCC 10790 (99.4%) followed by Kocuria polaris MTCC 3702 (98.2%), Kocuria rosea MTCC 2522 (98.2%), Kocuria flava MTCC 10971 (98.2%), Kocuria aegyptia MTCC 10791 (98.0%), Kocuria himachalensis MTCC 7020 (97.5%) and Kocuria atrinae MTCC 10972 (97.1%). However, the DNA-DNA hybridisation values obtained between strain FCS-11 and other related strains were well below the threshold that is required for the proposal of a novel species. The G+C content of the genomic DNA was 60.7 mol%. The phenotypic and genotypic data showed that the strain FCS-11 merits the recognition as a representative of a novel species of the genus Kocuria. It is proposed that the isolate should be classified in the genus Kocuria as a novel species, Kocuria sediminis sp. nov. The type strain is FCS-11 (= MTCC 10969 = JCM 17929). [ABSTRACT FROM AUTHOR]

Molybdenum sulfide (MoS 2 ) and modified MoS 2 with different percentages of CdS (10%, 30%, and 50% CdS@MoS 2 ) were successfully synthesized and characterized. The photocatalytic performance of the MoS 2 and CdS@MoS 2 was evaluated by degrading brilliant green (BG), methylene blue (MB), and rhodamine B (RhB) dyes under visible light irradiation. Amongst the synthesized photocatalysts, 50% CdS@MoS 2 exhibited the highest photocatalytic activity, degrading 97.6%, 90.3%, and 75.5% of BG, MB, and RhB dyes, respectively within 5 h. The active species involved in the degradation processes were investigated. All trapping agents inhibited BG and MB degradation to a similar extent, indicating that all of the probed active species play an important role in the degradation of BG and MB. In contrast, h + and O 2 •- were found to be the main reactive species in the photocatalytic RhB degradation. A potential mechanism for the photocatalytic degradation of dyes using CdS@MoS 2 has been proposed. This work highlights the potential of CdS@MoS 2 as a photocatalyst for more efficient water remediation applications., (© 2024. The Author(s).)

Foot-and-mouth disease (FMD) is highly infectious, limits live animal trade, and affects ranchers owing to the loss of animal yield. The present study was designed to perform vaccine matching for field FMD virus isolates from clinically diseased cattle and assess the antigenic properties of the field isolates against the current vaccine strains used for vaccine production at the National Veterinary Institute, Ethiopia. Both sequencing and reverse transcription-polymerase chain reactions were used for distinguishing between the viral strains. To evaluate the serological relationship of the vaccine strain with these field isolates (r1 value), in vitro cross-neutralization was performed using ETH/6/2000 and ETH/38/2005 antisera. Infectious field FMD viral samples represented serotypes A and O. Sequence analysis showed that serotype A VP1/1D possessed amino acid variability at positions 28 and 42 to 48, 138, 141, 142, 148, 156, 173, and 197 compared with the ETH/6/2000 vaccine strain, whereas serotype O possessed amino acid variability at positions 45, 48, 138, 139, 140, 141, and 197 compared with the ETH/38/2005 vaccine strain. Based on the one-dimensional virus neutralization test, serotypes A and O demonstrated antigenic matching of up to 13/17 (76.47%) with the vaccine strain, except for the isolates ETH/40/2018, ETH/48/2018, ETH/55/2018, and ETH/61/2018, which had r-values less than 0.3. Therefore, the currently used vaccine strains ETH/38/2005 for serotype O and ETH/6/2000 for serotype A protected against all and most field viruses characterized as serotypes O and A, respectively, and amino acid residue variation was observed in different FMD virus B-C loops, G-H loops, and C-termini of VP1 at sites 1 and 3 in both serotypes., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)