Discovery of new antimicrobial thiophene derivatives with activity against drug-resistant Gram negative-bacteria.

Our aim is to identify new small molecules with antimicrobial potential, especially against colistin-resistant (Col-R) Acinetobacter baumannii and Escherichia coli. After initial hits identification by fingerprint similarity, MIC of 24 heterocyclic derivatives for A. baumannii and E. coli reference strains, and bactericidal activity of selected thiophenes against Col-R strains were determined. We analyzed changes in bacterial membrane permeability and the OMPs profile. Additionally, we determined bacterial adherence to host cells and performed molecular docking studies to assess their binding to bacterial targets. The compounds' MICs ranged from 4 to >64 mg/L. Thiophene derivatives 4, 5 and 8 exhibited MIC50 values between 16 and 32 mg/L for Col-R A. baumannii and 8 and 32 mg/L for Col-R E. coli. The time-kill curve assay demonstrated that thiophenes 4 and 8 had bactericidal effects against Col-R A. baumannii and E. coli. Furthermore, treatment with them resulted in increased membrane permeabilization and reduced adherence of these isolates to host cells. Finally, the docking studies showed a stronger binding affinity to CarO1 and Omp33 of A. baumannii and OmpW and OmpC of E. coli. These findings indicate that thiophene derivatives possess antibacterial activity against Col-R A. baumannii and E. coli, suggesting that they may enhance the repertoire of drug treatments against bacteria.

Exploring the antimicrobial efficacy of Manuka honey against multidrug-resistant and extensively drug-resistant Salmonella Typhi causing septicemia in Pakistan.

Aim: To determine the efficacy of manuka honey against multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical strains of Salmonella Typhi. Materials & methods: Clinical isolates were processed using the Bactec blood culture system, identification and antibiogram by Vitek 2 and antibiotic resistance genes through polymerase chain reaction (PCR). Microbroth dilution assays evaluated the antibacterial activity of manuka honey. Results: MDR and XDR-S. Typhi was susceptible to azithromycin. These strains carried the H58, gyrA, gyrB, blaCTX-M-15 , and blaTEM-1 genes. At 100% honey, the zone of inhibition for MDR (15-23 mm) and XDR (15-24 mm) strains. 18/50 MDR and 14/50 XDR strains inhibited at 3.125 v/v% killed at 6.25 v/v% concentration respectively. Conclusion: Manuka honey could be an alternative option for treating S. Typhi infections.

Typhoid fever is a life-threatening bacterial infection caused by the Salmonella Typhi. These bacteria are transmitted through contaminated water and food and cause fever, abdominal pain, headache, vomiting, and diarrhea mainly in children under 5. There are around 9 million people get infected with S. Typhi, with an increased death of 1,10,000 annually. Bees that collect nectar from the blossoms of the Manuka tree in Australia and New Zealand produce a type of honey known as manuka honey. This honey is famous for its antibacterial activity, and potential health benefits. Therefore, we aimed to determine its antibacterial activity against S. Typhi. Our finding shows that the commonly available antibiotics did not kill S. Typhi because their DNA was drug-resistant. After applying the manuka honey, these bacteria were killed and given a clear zone ranging from 15­24mm on the agar plate. Further analysis revealed that at low concentrations of manuka honey, 3.1% and 6.25%, most of the S. Typhi stopped growing and killed, respectively. This study suggested that manuka honey, which is affordable and readily available, could be used as a treatment option to treat infections produced by these harmful bacteria after further analysis.

Iron-doped nanozymes with spontaneous peroxidase-mimic activity as a promising antibacterial therapy for bacterial keratitis.

The development of non-antibiotic pharmaceuticals with biocompatible and efficient antibacterial properties is of great significance for the treatment of bacterial keratitis. In this study, we have developed antibacterial iron-doped nanozymes (Fe3+-doped nanozymes, FNEs) with distinguished capacity to fight against bacterial infections. The iron-doped nanozymes are composed of Fe3+ doped zeolitic imidazolate framework-8 (Fe/ZIF-8) and polyethylene imide (PEI), which were functionally coated on the surface of Fe/ZIF-8 and imparted the FNEs with improved water dispersibility and biocompatibility. FNEs possess a significant spontaneous peroxidase-mimic activity without the need for external stimulation, thus elevating cellular reactive oxygen species level by catalyzing local H2O2 at the infection site and resulting in bacteria damaged to death. FNEs eliminated 100% of Staphylococcus aureus within 6 h, and significantly relieved inflammation and bacterial infection levels in mice bacterial keratitis, exhibiting higher bioavailability and a superior therapeutic effect compared to conventional antibiotic eye drops. In addition, the FNEs would not generate drug resistance, suggesting that FNEs have great potential in overcoming infectious diseases caused by antimicrobial resistant bacteria.

On-Site Inactivation for Disinfection of Antibiotic-Resistant Bacteria in Hospital Effluent by UV and UV-LED.

The problem of antimicrobial resistance (AMR) is not limited to the medical field but is also becoming prevalent on a global scale in the environmental field. Environmental water pollution caused by the discharge of wastewater into aquatic environments has caused concern in the context of the sustainable development of modern society. However, there have been few studies focused on the treatment of hospital wastewater, and the potential consequences of this remain unknown. This study evaluated the efficacy of the inactivation of antimicrobial-resistant bacteria (AMRB) and antimicrobial resistance genes (AMRGs) in model wastewater treatment plant (WWTP) wastewater and hospital effluent based on direct ultraviolet (UV) light irradiation provided by a conventional mercury lamp with a peak wavelength of 254 nm and an ultraviolet light-emitting diode (UV-LED) with a peak emission of 280 nm under test conditions in which the irradiance of both was adjusted to the same intensity. The overall results indicated that both UV- and UV-LED-mediated disinfection effectively inactivated the AMRB in both wastewater types (>99.9% after 1-3 min of UV and 3 min of UV-LED treatment). Additionally, AMRGs were also removed (0.2-1.4 log10 for UV 254 nm and 0.1-1.3 log10 for UV 280 nm), and notably, there was no statistically significant decrease (p < 0.05) in the AMRGs between the UV and UV-LED treatments. The results of this study highlight the importance of utilizing a local inactivation treatment directly for wastewater generated by a hospital prior to its flow into a WWTP as sewage. Although additional disinfection treatment at the WWTP is likely necessary to remove the entire quantity of AMRB and AMRGs, the present study contributes to a significant reduction in the loads of WWTP and urgent prevention of the spread of infectious diseases, thus alleviating the potential threat to the environment and human health risks associated with AMR problems.

Frequency of antimicrobial-resistant bloodstream infections in 111 hospitals in Thailand, 2022.

OBJECTIVES: To evaluate the frequency of antimicrobial-resistant bloodstream infections (AMR BSI) in Thailand. METHODS: We analyzed data from 2022, generated by 111 public hospitals in health regions 1 to 12, using the AutoMated tool for Antimicrobial resistance Surveillance System (AMASS), and submitted to the Ministry of Public Health, Thailand. Multilevel Poisson regression models were used. RESULTS: The most common cause of community-origin AMR BSI was third-generation cephalosporin-resistant Escherichia coli (3GCREC, 65.6%; 5101/7773 patients) and of hospital-origin AMR BSI was carbapenem-resistant Acinetobacter baumannii (CRAB, 51.2%, 4968/9747 patients). The percentage of patients tested for BSI was negatively associated with the frequency of community-origin 3GCREC BSI and hospital-origin CRAB BSI (per 100,000 tested patients). Hospitals in health regions 4 (lower central region) had the highest frequency of community-origin 3GCREC BSI (adjusted incidence rate ratio, 2.06; 95% confidence interval: 1.52-2.97). Health regions were not associated with the frequency of hospital-origin CRAB BSI, and between-hospital variation was high, even adjusting for hospital level and size. CONCLUSION: The high between-hospital variation of hospital-origin CRAB BSI suggests the importance of hospital-specific factors. Our approach and findings highlight health regions and hospitals where actions against AMR infection, including antimicrobial stewardship and infection control, should be prioritized.

Effects of meropenem supply restriction: A multicenter retrospective study.

BACKGROUND: In Japan, the supply of one generic meropenem product was restricted from August 2022 to March 2023. OBJECTIVE: To determine the effects of meropenem (MEPM) restriction. METHODS: We conducted a multicenter retrospective study comparing antimicrobial use, bacteremia mortality, and drug-resistant bacteria detected before the restriction of MEPM (control period), from September 2021 to February 2022, and after the restriction of MEPM (MEPM supply restriction period), from September 2022 to February 2023, in five institutions. RESULTS: The number of carbapenem days of therapy (DOTs) were decreased in all five institutions. Fourth-generation cephalosporin DOTs increased in all facilities, and piperacillin/tazobactam DOTs increased in four facilities. The 30-day and 90-day mortality rates were significantly higher during the MEPM supply restriction period than those during the control period. Moreover, survival time was significantly shorter during the MEPM supply restriction period than that during the control period. Multivariable analysis revealed that MEPM supply restriction, age >80 years, Pitt Bacteremia Score ≥4, platelet count <10 × 104/µL, serum albumin level <2.5 g/dL, and methicillin-resistant Staphylococcus aureus bloodstream infection were independent risk factors for 30-day mortality. The detection rates of carbapenem-resistant Pseudomonas aeruginosa and Enterobacteriaceae did not differ significantly between the two periods. CONCLUSIONS: MEPM supply restriction decreased the use of carbapenems and increased the use of other broad-spectrum antimicrobial agents, which worsened the prognosis of bacteremia. Overall, carbapenems are important drugs for the treatment of infectious diseases and are difficult to replace in unforeseen situations such as drug supply outages.

Metabolic remodeling by RNA polymerase gene mutations is associated with reduced ß-lactam susceptibility in oxacillin-susceptible MRSA.

The emergence of oxacillin-susceptible methicillin-resistant Staphylococcus aureus (OS-MRSA) has imposed further challenges to the clinical management of MRSA infections. When exposed to ß-lactam antibiotics, these strains can easily acquire reduced ß-lactam susceptibility through chromosomal mutations, including those in RNA polymerase (RNAP) genes such as rpoBC, which may then lead to treatment failure. Despite the increasing prevalence of such strains and the apparent challenges they pose for diagnosis and treatment, there is limited information available on the actual mechanisms underlying such chromosomal mutation-related transitions to reduced ß-lactam susceptibility, as it does not directly associate with the expression of mecA. This study investigated the cellular physiology and metabolism of six missense mutants with reduced oxacillin susceptibility, each carrying respective mutations on RpoBH929P, RpoBQ645H, RpoCG950R, RpoCG498D, RpiAA64E, and FruBA211E, using capillary electrophoresis-mass spectrometry-based metabolomics analysis. Our results showed that rpoBC mutations caused RNAP transcription dysfunction, leading to an intracellular accumulation of ribonucleotides. These mutations also led to the accumulation of UDP-Glc/Gal and UDP-GlcNAc, which are precursors of UTP-associated peptidoglycan and wall teichoic acid. Excessive amounts of building blocks then contributed to the cell wall thickening of mutant strains, as observed in transmission electron microscopy, and ultimately resulted in decreased susceptibility to ß-lactam in OS-MRSA. IMPORTANCE: The emergence of oxacillin-susceptible methicillin-resistant Staphylococcus aureus (OS-MRSA) strains has created new challenges for treating MRSA infections. These strains can become resistant to ß-lactam antibiotics through chromosomal mutations, including those in the RNA polymerase (RNAP) genes such as rpoBC, leading to treatment failure. This study investigated the mechanisms underlying reduced ß-lactam susceptibility in four rpoBC mutants of OS-MRSA. The results showed that rpoBC mutations caused RNAP transcription dysfunction, leading to an intracellular accumulation of ribonucleotides and precursors of peptidoglycan as well as wall teichoic acid. This, in turn, caused thickening of the cell wall and ultimately resulted in decreased susceptibility to ß-lactam in OS-MRSA. These findings provide insights into the mechanisms of antibiotic resistance in OS-MRSA and highlight the importance of continued research in developing effective treatments to combat antibiotic resistance.

Antimicrobial resistance and prevalence of Listeria species from raw milk and dairy products in Burdur, Turkey.

OBJECTIVES: Worldwide, but especially in emerging nations, concerns about food safety pose a serious obstacle to societal and economic progress. This research aimed to examine the prevalence of Listeria spp. in raw milk and dairy products in Burdur, as well as the presence of genes associated with biofilm formation and antibiotic resistance in the isolates. METHODS: A total of 185 samples, including raw milk, curd, cream, butter, yogurt and cheese, were randomly collected in Burdur. The enrichment and isolation methods specified by the United States Department of Agriculture was used to identify Listeria species in milk and dairy product samples. Culture-positive strains were identified as Listeria genus and as species by PCR. Antibiotic susceptibility of the isolates was evaluated against 14 antibiotics using the disc diffusion technique (EUCAST). RESULTS: Of them, 2.2% (4/185) were positive for Listeria spp. Listeria species were isolated from cheese and yogurt samples. Two of them were Listeria innocua 1.1% (2/185), one was Listeria ivanovii 0.5% (1/185) and the other was Listeria welshimeri 0.5% (1/185). As a result of multiplex PCR of the biofilm genotypic marker luxS and flaA genes, the flaA gene was detected in three of four isolates, the luxS gene was detected in one isolate, and these two genes were not found in one isolate. Although all isolates were resistant to gentamicin and rifampicin, they also showed multidrug resistance. CONCLUSION: This study revealed that the diversity of prevalence of Listeria spp. in Burdur requires microbial risk assessment in the milk and dairy products value chain and the need to focus on the problem of multiple antibiotic resistance.

The Oral Cavity-Another Reservoir of Antimicrobial-Resistant Staphylococcus aureus?

Staphylococcus aureus is one of the most common potentially pathogenic bacteria that may asymptomatically colonize many sites of healthy carriers. Non-nasal carriage, especially in the oral cavity, and its role in transmitting antimicrobial-resistant S. aureus strains in the healthcare community, is poorly understood. This study aimed to assess the prevalence and antimicrobial susceptibility of S. aureus in both oral and nasal cavities among preclinical dentistry students. A total of 264 oral and nasal swabs were taken from 132 participants, and all specimens were cultured using standard diagnostic procedures and antimicrobial susceptibility testing (EUCAST). The prevalence of S. aureus exclusively in the nasal (11.4%) or oral (9.1%) cavity was comparable, while concurrent oral and nasal carriage was present in 27.3% of participants. Although antibiotic resistance rates observed in both oral and nasal isolates were similar (ranging from 2.7% to 95.5%), 16.7% of carriers exhibited distinct antibiotic resistance profiles between oral and nasal isolates. Three (2.7%) methicillin-resistant S. aureus (MRSA) were isolated from the mouth and nose but multidrug resistance (27.3%) was more frequent in the oral than in the nasal isolates: 34% and 21.1%, respectively. This study demonstrated that preclinical dentistry students have a similar rate of oral S. aureus carriage as the nasal carriage rate, and that the oral cavity can be colonized by antimicrobial-resistant strains that do not originate from the nose. Consequently, the oral cavity seems to be an unjustly overlooked body site in screening for S. aureus carriage.

Pangenome-wide association study reveals the selective absence of CRISPR genes (Rv2816c-19c) in drug-resistant Mycobacterium tuberculosis.

The presence of intermittently dispersed insertion sequences and transposases in the Mycobacterium tuberculosis (Mtb) genome makes intra-genome recombination events inevitable. Understanding their effect on the gene repertoires (GR), which may contribute to the development of drug-resistant Mtb, is critical. In this study, publicly available WGS data of clinical Mtb isolates (endemic region n = 2,601; non-endemic region n = 1,130) were de novo assembled, filtered, scaffolded into assemblies, and functionally annotated. Out of 2,601 Mtb WGS data sets from endemic regions, 2,184 (drug resistant/sensitive: 1,386/798) qualified as high quality. We identified 3,784 core genes, 123 softcore genes, 224 shell genes, and 762 cloud genes in the pangenome of Mtb clinical isolates from endemic regions. Sets of 33 and 39 genes showed positive and negative associations (P < 0.01) with drug resistance status, respectively. Gene ontology clustering showed compromised immunity to phages and impaired DNA repair in drug-resistant Mtb clinical isolates compared to the sensitive ones. Multidrug efflux pump repressor genes (Rv3830c and Rv3855c) and CRISPR genes (Rv2816c-19c) were absent in the drug-resistant Mtb. A separate WGS data analysis of drug-resistant Mtb clinical isolates from the Netherlands (n = 1130) also showed the absence of CRISPR genes (Rv2816c-17c). This study highlights the role of CRISPR genes in drug resistance development in Mtb clinical isolates and helps in understanding its evolutionary trajectory and as useful targets for diagnostics development.IMPORTANCEThe results from the present Pan-GWAS study comparing gene sets in drug-resistant and drug-sensitive Mtb clinical isolates revealed intricate presence-absence patterns of genes encoding DNA-binding proteins having gene regulatory as well as DNA modification and DNA repair roles. Apart from the genes with known functions, some uncharacterized and hypothetical genes that seem to have a potential role in drug resistance development in Mtb were identified. We have been able to extrapolate many findings of the present study with the existing literature on the molecular aspects of drug-resistant Mtb, further strengthening the relevance of the results presented in this study.

The Impact of an Antimicrobial Stewardship Program on Days of Therapy in the Pediatric Center: An Interrupted Time-Series Analysis of a 19-Year Study.

BACKGROUND: We aimed to analyze the effects of an antimicrobial stewardship program (ASP) on the proportion of antimicrobial-resistant pathogens in bacteremia, antimicrobial use, and mortality in pediatric patients. METHODS: A retrospective single-center study was performed on pediatric inpatients under 19 years old who received systemic antimicrobial treatment from 2001 to 2019. A pediatric infectious disease attending physician started ASP in January 2008. The study period was divided into the pre-intervention (2001-2008) and the post-intervention (2009-2019) periods. The amount of antimicrobial use was defined as days of therapy per 1,000 patient-days, and the differences were compared using delta slope (= changes in slopes) between the two study periods by an interrupted time-series analysis. The proportion of resistant pathogens and the 30-day overall mortality rate were analyzed by the χ². RESULTS: The proportion of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae bacteremia increased from 17% (39 of 235) in the pre-intervention period to 35% (189 of 533) in the post-intervention period (P < 0.001). The total amount of antimicrobial use significantly decreased after the introduction of ASP (delta slope value = -16.5; 95% confidence interval [CI], -30.6 to -2.3; P = 0.049). The 30-day overall mortality rate in patients with bacteremia did not increase, being 10% (55 of 564) in the pre-intervention and 10% (94 of 941) in the post-intervention period (P = 0.881). CONCLUSION: The introduction of ASP for pediatric patients reduced the delta slope of the total antimicrobial use without increasing the mortality rate despite an increased incidence of ESBL-producing gram-negative bacteremia.

Nanotechnology improves the detection of bacteria: Recent advances and future perspectives.

Nanotechnology has advanced significantly, particularly in biomedicine, showing promise for nanomaterial applications. Bacterial infections pose persistent public health challenges due to the lack of rapid pathogen detection methods, resulting in antibiotic overuse and bacterial resistance, threatening the human microbiome. Nanotechnology offers a solution through nanoparticle-based materials facilitating early bacterial detection and combating resistance. This study explores recent research on nanoparticle development for controlling microbial infections using various nanotechnology-driven detection methods. These approaches include Surface Plasmon Resonance (SPR) Sensors, Surface-Enhanced Raman Scattering (SERS) Sensors, Optoelectronic-based sensors, Bacteriophage-Based Sensors, and nanotechnology-based aptasensors. These technologies provide precise bacteria detection, enabling targeted treatment and infection prevention. Integrating nanoparticles into detection approaches holds promise for enhancing patient outcomes and mitigating harmful bacteria spread in healthcare settings.

Socioeconomic Disparities and the Prevalence of Antimicrobial Resistance.

BACKGROUND: The increased prevalence of antimicrobial resistant (AMR) infections is a significant global health threat, resulting in increased morbidity, mortality, and costs. The drivers of AMR are complex and potentially impacted by socioeconomic factors. We investigated the relationships between geographic and socioeconomic factors and AMR. METHODS: We collected select patient bacterial culture results from 2015 to 2020 from electronic health records (EHR) of two expansive healthcare systems within the Dallas-Fort Worth, TX (DFW) metropolitan area. Among individuals with EHR records who resided in the four most populus counties in DFW, culture data were aggregated. Case counts for each organism studied were standardized per 1,000 persons per area population. Using residential addresses, the cultures were geocoded and linked to socioeconomic index values. Spatial autocorrelation tests identified geographic clusters of high and low AMR organism prevalence and correlations with established socioeconomic indices. RESULTS: We found significant clusters of AMR organisms in areas with high levels of deprivation, as measured by the Area Deprivation Index (ADI). We found a significant spatial autocorrelation between ADI and the prevalence of AMR organisms, particularly for AmpC and MRSA with 14% and 13%, respectively, of the variability in prevalence rates being attributable to their relationship with the ADI values of the neighboring locations. CONCLUSIONS: We found that areas with a high ADI are more likely to have higher rates of AMR organisms. Interventions that improve socioeconomic factors such as poverty, unemployment, decreased access to healthcare, crowding, and sanitation in these areas of high prevalence may reduce the spread of AMR.

Phenotypic and molecular characterization of clinically isolated antibiotics-resistant S. aureus (MRSA), E. coli (ESBL) and Acinetobacter 1379 bacterial strains.

Antibiotic-resistant bacteria causing nosocomial infections pose a significant global health concern. This study focused on examining the lipid profiles of both non-resistant and clinically resistant strains of Staphylococcus aureus (MRSA 1418), E. coli (ESBL 1384), and Acinetobacter 1379. The main aim was to investigate the relationship between lipid profiles, hydrophobicity, and antibiotic resistance so as to identify the pathogenic potential and resistance factors of strains isolated from patients with sepsis and urinary tract infections (UTIs). The research included various tests, such as antimicrobial susceptibility assays following CLSI guidelines, biochemical tests, biofilm assays, and hydrophobicity assays. Additionally, gas chromatography mass spectrometry (GC-MS) and GC-Flame Ionization Detector (GC-FID) analysis were used for lipid profiling and composition. The clinically isolated resistant strains (MRSA-1418, ESBL-1384, and Acinetobacter 1379) demonstrated resistance phenotypes of 81.80%, 27.6%, and 63.6%, respectively, with a multiple antibiotic resistance index of 0.81, 0.27, and 0.63. Notably, the MRSA-1418 strain, which exhibited resistance, showed significantly higher levels of hemolysin, cell surface hydrophobicity, biofilm index, and a self-aggregative phenotype compared to the non-resistant strains. Gene expression analysis using quantitative real-time PCR (qPCR). Indicated elevated expression levels of intercellular adhesion biofilm-related genes (icaA, icaC, and icaD) in MRSA-1418 (pgaA, pgaC, and pgaB) and Acinetobacter 1379 after 24 h compared to non-resistant strains. Scanning electron microscopy (SEM) was employed for structural investigation. These findings provide valuable insights into the role of biofilms in antibiotic resistance and suggest potential target pathways for combating antibiotic-resistant bacteria.

The CRISPR/Cas system as an antimicrobial resistance strategy in aquatic ecosystems.

With the growing population, demand for food has dramatically increased, and fisheries, including aquaculture, are expected to play an essential role in sustaining demand with adequate quantities of protein and essential vitamin supplements, employment generation, and GDP growth. Unfortunately, the incidence of emerging/re-emerging AMR pathogens annually occurs because of anthropogenic activities and the frequent use of antibiotics in aquaculture. These AMR pathogens include the WHO's top 6 prioritized ESKAPE pathogens (nosocomial pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), extended-spectrum beta lactases (ESBLs) and carbapenemase-producing E. coli, which pose major challenges to the biomagnification of both nonnative and native antibiotic-resistant bacteria in capture and cultured fishes. Although implementing the rational use of antibiotics represents a promising mitigation measure, this approach is practically impossible due to the lack of awareness among farmers about the interplay between antimicrobial use and the emergence of antimicrobial resistance (AMR). Nevertheless, to eradicate these 'superbugs,' CRISPR/Cas (clustered regularly interspersed short palindromic repeats/CRISPR associate protein) has turned out to be a novel approach owing to its ability to perform precise site-directed targeting/knockdown/reversal of specific antimicrobial resistance genes in vitro and to distinguish AMR-resistant bacteria from a plethora of commensal aquatic bacteria. Along with highlighting the importance of virulent multidrug resistance genes in bacteria, this article aims to provide a holistic picture of CRISPR/Cas9-mediated genome editing for combating antimicrobial-resistant bacteria isolated from various aquaculture and marine systems, as well as insights into different types of CRISPR/Cas systems, delivery methods, and challenges associated with developing CRISPR/Cas9 antimicrobial agents.

Computational Strategies in Drug Discovery: Leveraging Subtractive Genomic Analysis for Target Identification.

The utilization of In-silico subtractive genomic analysis has emerged as an important and essential method in modern drug discovery and development since it significantly improves the process of identifying and validating potential targets for discovering novel therapeutic compounds to treat severe infections caused by Antimicrobial-resistant (AMR) - pathogenic species. This review provides a complete overview of the methodology, advantages, disadvantages, and prospects, associated with subtractive genomic research in the context of drug discovery and development. The initial phase of analysis encompasses the retrieval of data, which serves as a foundation for the subsequent data mining process in Phase 1. After data mining, Phase 2 utilizes subtractive channels for the target's non-homology and essentiality analysis. Phase 3 of the study aims to provide a comprehensive understanding of prospective targets by their qualitative characterization. Further, Phase 4 of the study emphasizes on conducting structure-based analyses, which involves the determination, refinement, evaluation, and validation of three-dimensional structures of the target proteins, along with their active site prediction and selection of the novel therapeutic compounds against that active site on the obtained targets through virtual screening and docking studies by utilizing various databases and servers. The therapeutic compounds obtained can be then validated by in vitro and in vivo testing, thereby establishing a connection between the computational predictions and real applications.

Bacteriophages and bacterial extracellular vesicles, threat or opportunity?

Emergence of antimicrobial-resistant bacteria (AMR) is one of the health major problems worldwide. The scientists are looking for a novel method to treat infectious diseases. Phage therapy is considered a suitable approach for treating infectious diseases. However, there are different challenges in this way. Some biological aspects can probably influence on therapeutic results and further investigations are necessary to reach a successful phage therapy. Bacteriophage activity can influence by bacterial defense system. Bacterial extracellular vesicles (BEVs) are one of the bacterial defense mechanisms which can modify the results of bacteriophage activity. BEVs have the significant roles in the gene transferring, invasion, escape, and spreading of bacteriophages. In this review, the defense mechanisms of bacteria against bacteriophages, especially BEVs secretion, the hidden linkage of BEVs and bacteriophages, and its possible consequences on the bacteriophage activity as well phage therapy will be discussed.

Race and ethnicity as risk factors for colonization and infection with key bacterial pathogens: a scoping review.

Background: Racial and ethnic disparities in infectious disease burden have been reported in the USA and globally, most recently for COVID-19. It remains unclear whether such disparities also exist for priority bacterial pathogens that are increasingly antibiotic-resistant. We conducted a scoping review to summarize published studies that report on colonization or community-acquired infection with pathogens among different races and ethnicities. Methods: We conducted an electronic literature search of MEDLINE®, Daily, Global Health, Embase, Cochrane Central, and Web of Science from inception to January 2022 for eligible observational studies. Abstracts and full-text publications were screened in duplicate for studies that reported data for race or ethnicity for at least one of the pathogens of interest. Results: Fifty-four observational studies in 59 publications met our inclusion criteria. Studies reported results for Enterobacterales, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus, and were conducted in Australia, Brazil, Israel, New Zealand, and USA. USA studies most often examined Black and Hispanic minority groups with studies regularly reporting a higher risk of these pathogens in Black persons and mixed results for Hispanic persons. Ethnic minority groups (e.g. Bedouins in Israel, Aboriginals in Australia) were often reported to be at a higher risk in other countries. Conclusion: Sufficient evidence was identified in this scoping review justifying future systematic reviews and meta-analyses evaluating the relationship between community-acquired pathogens and race and ethnicity. However, we noted that only a fraction of studies reported data stratified by race and ethnicity, highlighting a substantial gap in the literature.

A framework for leveraging network course-based undergraduate research experience (CURE) faculty to develop, validate, and administer an assessment instrument.

Over the last several years, nationally disseminated course-based undergraduate research experiences (CUREs) have emerged as an alternative to developing a novel CURE from scratch, but objective assessment of these multi-institution (network) CUREs across institutions is challenging due to differences in student populations, instructors, and fidelity of implementation. The time, money, and skills required to develop and validate a CURE-specific assessment instrument can be prohibitive. Here, we describe a co-design process for assessing a network CURE [the Prevalence of Antibiotic Resistance in the Environment (PARE)] that did not require support through external funding, was a relatively low time commitment for participating instructors, and resulted in a validated instrument that is usable across diverse PARE network institution types and implementation styles. Data collection efforts have involved over two dozen unique institutions, 42 course offerings, and over 1,300 pre-/post-matched assessment record data points. We demonstrated significant student learning gains but with small effect size in both content and science process skills after participation in the two laboratory sessions associated with the core PARE module. These results show promise for the efficacy of short-duration CUREs, an educational research area ripe for further investigation, and may support efforts to lower barriers for instructor adoption by leveraging a CURE network for developing and validating assessment tools.

Prevalence, molecular characterization, and antimicrobial resistance among Escherichia coli, Salmonella spp., and Staphylococcus aureus strains isolated from Egyptian broiler chicken flocks with omphalitis.

Background: Bacterial Omphalitis has been reported as a significant cause of mortalities in newly hatched broiler chicks. Aim: This study aimed to assess the occurrence of omphalitis among broiler chickens in Gharbia governorate in Egypt. In addition, the bacteria associated with the occurrence of omphalitis in broiler chickens were also investigated and characterized. Methods: For this purpose, 43 farms in that area were surveyed. The comparative levels of omphalitis caused by Escherichia coli (E. coli), Salmonella spp., and Staphylococcus aureus (S. aureus) were screened in 129 chicks. The drug resistance to eight commonly used antimicrobials in Egyptian poultry farms was screened using the disk diffusion method. Results: The overall incidence rate of omphalitis was 37.21%. In birds with omphalitis, the co-prevalence of S. aureus, Salmonella spp., and E. coli was 87.5%. When compared to healthy flocks, broiler chicks with omphalitis caused by Salmonella spp., E. coli, and S. aureus had a greater mortality rate in the first week of life. However, there were no significant differences in the mortality cases caused by these pathogens. Eighty-seven percent of the cases of omphalitis were linked to E. coli and 75% to Salmonella spp. and S. aureus. From the yolk sac of broiler chicks with omphalitis, E. coli, Salmonella spp., and S. aureus were isolated at rates of 87.5%, 62.5%, and 45.8%, respectively. The isolates of E. coli and Salmonella spp. exhibited great sensitivity to gentamycin and Tetracycline; however, the strongest drug resistance was observed toward cefpodoxime, sulphamethoxazole and trimethoprim, ampicillin, and amoxycillin and clavulanic acid. The recovered isolates of S. aureus showed susceptibility to chloramphenicol (72.37%), oxytetracycline (81.82%), and erythromycin (81.82%). However, every S. aureus isolate that was found resistant to amoxycillin and clavulanic acid, penicillin G and oxacillin. of blaTEM, blaSHV, and blaCTX-M genes has been proposed as the genetic cause of ß-lactam antibiotic resistance in Salmonella spp. and E. coli. MecA and blaZ; however, were found in every strain of S. aureus. Conclusion: The frequency of omphalitis and its associated mortalities was comparatively high in Gharbia governorate. More efforts should be made to adopt strict hygienic standards for controlling and preventing such disease and this will consequently lead to minimizing the use of antimicrobials in poultry farms.