A global systematic review and meta-analysis on correlation between Biofilm producers and Non-biofilm producers with antibiotic resistance in Uropathogenic Escherichiacoli

Molecular and computational insights into algD biofilm genes in multi drug resistant and extensively drug resistant Pseudomonasaeruginosa

Antibiotic-resistance and biofilm formation are the main virulence factors and present a serious treatment challenge in Pseudomonas aeruginosa. This study aimed to investigate antimicrobial resistance, genetic diversity, biofilm-specific algD gene, and computational analysis of clinical isolates. Forty two isolates of P. aeruginosa were examined by PCR, ELISA, sangers sequencing, phylogenetic analysis, MolProbity score, 3D structural modelling, Ramachandran plot, multiple sequence alignment, and protein domain analysis. According to the results, PCR analysis revealed algD gene presence in all isolates. ELISA showed 55 % (n = 23) of the samples produced strong biofilms, 38 % (n = 16) produced moderate biofilms, and 7 % (3) produced weak biofilms. The evolutionary relationships of 8 (S1-S8) P. aeruginosa strains with 81 reference strains were illustrated by the phylogenetic tree. Samples S1-S8 showed excellent MolProbity score (<1.00), low clashed scores (0.67-0.70), most residues in the favored regions (∼96.2-96.5 %), low Ramachandran outliers (0.53-0.56 %), low Rotamer outlier (0.62 %), low bad angles (<2), indicated high-quality models and values preferred percentages showed excellent models with structural refinement. Over all samples S5 and S6 stood out as the top choices for high-confidence modeling and applications. The essential catalytic domain UDP-glucose/GDP-mannose dehydrogenase was identified that could be used as important therapeutic targets. High quality models indicated suitability for downstream applications, such as studying protein-ligand interactions, understanding structural aspects of biofilm-resistant bacteria. This study improved our knowledge of the mechanisms underlying P. aeruginosa biofilm resistance and sets the stage for the development of novel therapeutic and diagnostic strategies to combat multidrug resistant strains.

The role of hydroponic solution of Ulva fasciata in modulating the antibiotic resistance of Vibrio alginolyticus

AIMS

This study aimed to ascertain the active substances in the hydroponic solution of Ulva (U.) fasciata (HSUF) and their effects on antibiotics resistance of pathogenic bacteria Vibrio alginolyticus (Va.) at environmental levels.

METHODS AND RESULTS

Analytical results of HSUF by solid-phase extraction and gas chromatography-mass spectrometry showed that HSUF contained rich active substances and dominated by 2,4,6-tribromophenol, acetal, mono (2-ethylhexyl) phthalate, and 2-(4-hydroxybenzene) ethanol, etc. Thereinto, 2,4,6-tribromophenol had the lowest minimal inhibitory concentrations of 64-128 μg ml-1 for Va. strains. The rich antibacterial substances of HSUF inhibited 47%-63% of isolated Va. strains. After 20 generations of subculture for Va. strains in three dilutes [1/2 (HT), 1/20 (MT), and 1/50 (LT)] of HSUF (20 g l-1), the resistance to streptomycin of Va. S1 and Va. M3 changed from intermediate resistance ability to susceptible level. The large promotion of reactive oxygen species was observed in different HSUF levels, but the biofilm formation of Va. S1 did not change significantly. Transcriptome sequencing of Va. S1 demonstrated that antibiotic resistance gene lpxA was downregulated at different HSUF levels.

CONCLUSIONS

Live U. fasciata excreted a variety of active secondary metabolites in HSUF, which exhibited strong inhibitory effects on three isolated Va. strains. HSUF changed the antibiotic resistance of Va. Strain, especially at higher HSUF concentrations.

A review of the mechanisms that confer antibiotic resistance in pathotypes of E. coli

The dissemination of antibiotic resistance in Escherichia coli poses a significant threat to public health worldwide. This review provides a comprehensive update on the diverse mechanisms employed by E. coli in developing resistance to antibiotics. We primarily focus on pathotypes of E. coli (e.g., uropathogenic E. coli) and investigate the genetic determinants and molecular pathways that confer resistance, shedding light on both well-characterized and recently discovered mechanisms. The most prevalent mechanism continues to be the acquisition of resistance genes through horizontal gene transfer, facilitated by mobile genetic elements such as plasmids and transposons. We discuss the role of extended-spectrum β-lactamases (ESBLs) and carbapenemases in conferring resistance to β-lactam antibiotics, which remain vital in clinical practice. The review covers the key resistant mechanisms, including: 1) Efflux pumps and porin mutations that mediate resistance to a broad spectrum of antibiotics, including fluoroquinolones and aminoglycosides; 2) adaptive strategies employed by E. coli, including biofilm formation, persister cell formation, and the activation of stress response systems, to withstand antibiotic pressure; and 3) the role of regulatory systems in coordinating resistance mechanisms, providing insights into potential targets for therapeutic interventions. Understanding the intricate network of antibiotic resistance mechanisms in E. coli is crucial for the development of effective strategies to combat this growing public health crisis. By clarifying these mechanisms, we aim to pave the way for the design of innovative therapeutic approaches and the implementation of prudent antibiotic stewardship practices to preserve the efficacy of current antibiotics and ensure a sustainable future for healthcare.

Biofilm antimicrobial susceptibility testing: where are we and where could we be going?

Our knowledge about the fundamental aspects of biofilm biology, including the mechanisms behind the reduced antimicrobial susceptibility of biofilms, has increased drastically over the last decades. However, this knowledge has so far not been translated into major changes in clinical practice. While the biofilm concept is increasingly on the radar of clinical microbiologists, physicians, and healthcare professionals in general, the standardized tools to study biofilms in the clinical microbiology laboratory are still lacking; one area in which this is particularly obvious is that of antimicrobial susceptibility testing (AST). It is generally accepted that the biofilm lifestyle has a tremendous impact on antibiotic susceptibility, yet AST is typically still carried out with planktonic cells. On top of that, the microenvironment at the site of infection is an important driver for microbial physiology and hence susceptibility; but this is poorly reflected in current AST methods. The goal of this review is to provide an overview of the state of the art concerning biofilm AST and highlight the knowledge gaps in this area. Subsequently, potential ways to improve biofilm-based AST will be discussed. Finally, bottlenecks currently preventing the use of biofilm AST in clinical practice, as well as the steps needed to get past these bottlenecks, will be discussed.

Potential of Desert Medicinal Plants for Combating Resistant Biofilms in Urinary Tract Infections

Urinary tract infections (UTIs) are among the most prevalent bacterial infections worldwide, with 11% of the global population getting infected every year. These infections are largely attributed to quorum sensing (QS)-dependent ability of pathogens to form biofilms in the urinary tract. Antimicrobial resistance is increasing, and the use of antimicrobial medicines in the future is yet uncertain. The desert medicinal plants have great potential to treat several diseases as per the available ethnobotanical database. Some of these plants have been used in folklore medicines to treat urinary tract infections also. There are many bioactive compounds derived from these desert medicinal plants that have been documented to possess antimicrobial as well as antibiofilm activity against uropathogens. The minimum biofilm inhibitory concentration (MBIC) of these plant extracts have been reported in the range of 31.5-250 μg/mL. The rising prevalence of drug-resistant diseases necessitates standardised modern analytical technologies to detect and isolate novel bioactive compounds from medicinal plants. This review seeks to combine the studies of desert plants with antimicrobial and anti-quorum sensing properties, supporting their sustainable use in treatment of urinary tract infections.

Classification of electrocardiogram signals using deep learning based on genetic algorithm feature extraction

Arrhythmias using electrocardiogram (ECG) signal is important in medical and computer research due to the timely diagnosis of dangerous cardiac conditions. The current study used the ECG to classify cardiac signals into normal heartbeats, congestive heart failure, ventricular arrhythmias, atrial fibrillation arrhythmias, atrial flutter, malignant ventricular arrhythmias, and premature atrial fibrillation. A deep learning algorithm was used to identify and diagnose cardiac arrhythmias. We proposed a new ECG signal classification method to increase signal classification sensitivity. We smoothed the ECG signal with noise removal filters. A discrete wavelet transform based on an arrhythmic database was applied to extract ECG features. Feature vectors were obtained based on wavelet decomposition energy properties and calculated values of PQRS morphological features. We used the genetic algorithm to reduce the feature vector and determine the input layer weights of the artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS). Proposed methods for classifying ECG signals were in different classes of rhythm to diagnose heart rhythm diseases. Training data was with 80% of the data set and test data was with 20% for the whole data set. The learning accuracy for the results of training and test data in the ANN classifier was calculated as 99.9% and 88.92% and in ANFIS as 99.8% and 88.83% respectively. Based on these results, good accuracy was observed.

Discovery of Novel Resistance Mechanisms of Vibrio parahaemolyticus Biofilm against Aminoglycoside Antibiotics

Inappropriate use of antibiotics eventually leads to the emergence of antibiotic-resistant strains and invalidates the treatment of infectious diseases. Aminoglycoside antibiotics (AGAs) are a class of broad-spectrum cationic antibiotics widely used for the treatment of Gram-negative bacterial infections. Understanding the AGA resistance mechanism of bacteria would increase the efficacy of treating these infections. This study demonstrates a significant correlation between AGA resistance and the adaptation of biofilms by Vibrio parahaemolyticus (VP). These adaptations were the result of challenges against the aminoglycosides (amikacin and gentamicin). Confocal laser scanning microscope (CLSM) analysis revealed an enclosure type mechanism where the biological volume (BV) and average thickness (AT) of V. parahaemolyticus biofilm were significantly positively correlated with amikacin resistance (BIC) (p < 0.01). A neutralization type mechanism was mediated by anionic extracellular polymeric substances (EPSs). The biofilm minimum inhibitory concentrations of amikacin and gentamicin were reduced from 32 µg/mL to 16 µg/mL and from 16 µg/mL to 4 µg/mL, respectively, after anionic EPS treatment with DNase I and proteinase K. Here, anionic EPSs bind cationic AGAs to develop antibiotic resistance. Transcriptomic sequencing revealed a regulatory type mechanism, where antibiotic resistance associated genes were significantly upregulated in biofilm producing V. parahaemolyticus when compared with planktonic cells. The three mechanistic strategies of developing resistance demonstrate that selective and judicious use of new antibiotics are needed to win the battle against infectious disease.

Novel tetrahydropyrimidinyl-substituted benzimidazoles and benzothiazoles: synthesis, antibacterial activity, DNA interactions and ADME profiling

A series of tetrahydropyrimidinyl-substituted benzimidazoles attached to various aliphatic or aromatic residues via phenoxymethylene were synthesised to investigate their antibacterial activities against selected Gram-positive and Gram-negative bacteria. The influence of the type of substituent at the C-3 and C-4 positions of the phenoxymethylene linker on the antibacterial activity was observed, showing that the aromatic moiety improved the antibacterial potency. Of all the evaluated compounds, benzoyl-substituted benzimidazole derivative 15a was the most active compound, particularly against the Gram-negative pathogens E. coli (MIC = 1 μg mL^-1) and M. catarrhalis (MIC = 2 μg mL^-1). Compound 15a also exhibited the most promising antibacterial activity against sensitive and resistant strains of S. pyogenes (MIC = 2 μg mL^-1). Significant stabilization effects and positive induced CD bands strongly support the binding of the most biologically active benzimidazoles inside the minor grooves of AT-rich DNA, in line with docking studies. The predicted physico-chemical and ADME properties lie within drug-like space except for low membrane permeability, which needs further optimization. Our findings encourage further development of novel structurally related 5(6)-tetrahydropyrimidinyl substituted benzimidazoles in order to optimize their antibacterial effect against common respiratory pathogens.

Prevalence of algD, pslD, pelF, Ppgl, and PAPI-1 Genes Involved in Biofilm Formation in Clinical Pseudomonas aeruginosa Strains

Introduction

Biofilm formation is one of the main virulence factors in Pseudomonas aeruginosa infections. This study is aimed at investigating the presence of genes involved in biofilm formation in clinical P. aeruginosa isolates. Material and Methods. A cross-sectional study was conducted on 112 P. aeruginosa isolates. The biofilm formation assay was performed on all isolates. Antimicrobial resistance was determined by the disk diffusion method, and the presence of genes was detected by polymerase chain reaction. Isolates were typed with Rep-PCR.

Results

The results of biofilm formation demonstrated that 85 strains (75.9%) were biofilm producers, and 27 strains (24.1%) were nonproducer isolates. Antibiotic susceptibility pattern in biofilm-positive and biofilm-negative isolates obtained from hospitalized patients showed a high rate of antibiotic resistance to amoxicillin with 95.7% and 92.3%, respectively. Based on PCR amplification results, the frequency of genes involved in biofilm formation among all isolates was as follows: algD (78.6%), pelF (70.5%), pslD (36.6%), Ppgl (0%), and PAPI-1 (77.6%). Rep-PCR typing demonstrated that 112 P. aeruginosa isolates were classified into 57 types according to 70% cut-off. The predominant type was A which contained 15 isolates. Moreover, 7 isolates were clustered in genotype B, followed by C type (6), D (4), E (4), F (4), G (4), H (3), I (3), J (3 isolates), and 12 genotypes, each containing two isolates. Also, 35 isolates were distributed in scattered patterns and showed single types.

Conclusion

Study results showed significant association between biofilm formation and resistance to antibiotics such as ceftazidime and meropenem. Analysis of Rep-PCR patterns indicated that the evaluated isolates were heterogeneous, relatively.