-
Communications Biology Jun 2024Antimicrobial resistance (AMR) poses a serious threat to the clinical management of typhoid fever. AMR in Salmonella Typhi (S. Typhi) is commonly associated with the H58...
Antimicrobial resistance (AMR) poses a serious threat to the clinical management of typhoid fever. AMR in Salmonella Typhi (S. Typhi) is commonly associated with the H58 lineage, a lineage that arose comparatively recently before becoming globally disseminated. To better understand when and how H58 emerged and became dominant, we performed detailed phylogenetic analyses on contemporary genome sequences from S. Typhi isolated in the period spanning the emergence. Our dataset, which contains the earliest described H58 S. Typhi organism, indicates that ancestral H58 organisms were already multi-drug resistant (MDR). These organisms emerged spontaneously in India in 1987 and became radially distributed throughout South Asia and then globally in the ensuing years. These early organisms were associated with a single long branch, possessing mutations associated with increased bile tolerance, suggesting that the first H58 organism was generated during chronic carriage. The subsequent use of fluoroquinolones led to several independent mutations in gyrA. The ability of H58 to acquire and maintain AMR genes continues to pose a threat, as extensively drug-resistant (XDR; MDR plus resistance to ciprofloxacin and third generation cephalosporins) variants, have emerged recently in this lineage. Understanding where and how H58 S. Typhi originated and became successful is key to understand how AMR drives successful lineages of bacterial pathogens. Additionally, these data can inform optimal targeting of typhoid conjugate vaccines (TCVs) for reducing the potential for emergence and the impact of new drug-resistant variants. Emphasis should also be placed upon the prospective identification and treatment of chronic carriers to prevent the emergence of new drug resistant variants with the ability to spread efficiently.
Topics: Salmonella typhi; Typhoid Fever; Phylogeny; Humans; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Haplotypes; Mutation; Genome, Bacterial
PubMed: 38942806
DOI: 10.1038/s42003-024-06451-8 -
Progress in Molecular Biology and... 2024The rise of multidrug-resistant bacteria is a well-recognized threat to world health, necessitating the implementation of effective treatments. This issue has been... (Review)
Review
The rise of multidrug-resistant bacteria is a well-recognized threat to world health, necessitating the implementation of effective treatments. This issue has been identified as a top priority on the global agenda by the World Health Organization. Certain strains, such as Candida glabrata, Candida krusei, Candida lusitaniae, Candida auris, select cryptococcal species, and opportunistic Aspergillus or Fusarium species, have significant intrinsic resistance to numerous antifungal medicines. This inherent resistance and subsequent suboptimal clinical outcomes underscore the critical imperative for enhanced therapeutic alternatives and management protocols. The challenge of effectively treating fungal infections, compounded by the protracted timelines involved in developing novel drugs, underscores the pressing need to explore alternative therapeutic avenues. Among these, drug repurposing emerges as a particularly promising and expeditious solution, providing cost-effective solutions and safety benefits. In the fight against life-threatening resistant fungal infections, the idea of repurposing existing medications has encouraged research into both established and new compounds as a last-resort therapy. This chapter seeks to provide a comprehensive overview of contemporary antifungal drugs, as well as their key resistance mechanisms. Additionally, it seeks to provide insight into the antimicrobial properties of non-traditional drugs, thereby offering a holistic perspective on the evolving landscape of antifungal therapeutics.
Topics: Drug Repositioning; Humans; Antifungal Agents; Mycoses; Drug Resistance, Fungal; Animals
PubMed: 38942545
DOI: 10.1016/bs.pmbts.2024.04.002 -
PloS One 2024A growing increase in the number of serious infections caused by multidrug resistant bacteria (MDR) is challenging our society. Despite efforts to discover novel...
A growing increase in the number of serious infections caused by multidrug resistant bacteria (MDR) is challenging our society. Despite efforts to discover novel therapeutic options, few antibiotics targeting MDR have been approved by the Food and Drug Administration (FDA). Lactic acid bacteria have emerged as a promising therapeutic alternative due to their demonstrated ability to combat MDR pathogens in vitro. Our previous co-culture studies showed Lacticaseibacillus rhamnosus CRL 2244 as having a potent killing effect against carbapenem-resistant Acinetobacter baumannii (CRAB) strains. Here we report that cell-free conditioned media (CFCM) samples obtained from Lcb. rhamnosus CRL 2244 cultures incubated at different times display antimicrobial activity against 43 different pathogens, including CRAB, methicillin-resistant Staphylococcus aureus (MRSA) and carbapenemase Klebsiella pneumoniae (KPC)-positive strains. Furthermore, transwell and ultrafiltration analyses together with physical and chemical/biochemical tests showed that Lcb. rhamnosus CRL 2244 secretes a <3 kDa metabolite(s) whose antimicrobial activity is not significantly impaired by mild changes in pH, temperature and various enzymatic treatments. Furthermore, sensitivity and time-kill assays showed that the bactericidal activity of the Lcb. rhamnosus CRL 2244 metabolite(s) enhances the activity of some current FDA approved antibiotics. We hypothesize that this observation could be due to the effects of Lcb. rhamnosus CRL 2244 metabolite(s) on cell morphology and the enhanced transcriptional expression of genes coding for the phenylacetate (PAA) and histidine catabolic Hut pathways, metal acquisition and biofilm formation, all of which are associated with bacterial virulence. Interestingly, the extracellular presence of Lcb. rhamnosus CRL 2244 induced the transcription of the gene coding for the CidA/LgrA protein, which is involved in programmed cell death in some bacteria. Overall, the findings presented in this report underscore the promising potential of the compound(s) released by Lcb. rhamnosus CRL2244 as an alternative and/or complementary option to treat infections caused by A. baumannii as well as other MDR bacterial pathogens.
Topics: Lacticaseibacillus rhamnosus; Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Acinetobacter baumannii; Drug Synergism; Methicillin-Resistant Staphylococcus aureus; Culture Media, Conditioned; Bacterial Proteins
PubMed: 38941324
DOI: 10.1371/journal.pone.0306273 -
Bioinformatics (Oxford, England) Jun 2024World Health Organization estimates that there were over 10 million cases of tuberculosis (TB) worldwide in 2019, resulting in over 1.4 million deaths, with a worrisome...
MOTIVATION
World Health Organization estimates that there were over 10 million cases of tuberculosis (TB) worldwide in 2019, resulting in over 1.4 million deaths, with a worrisome increasing trend yearly. The disease is caused by Mycobacterium tuberculosis (MTB) through airborne transmission. Treatment of TB is estimated to be 85% successful, however, this drops to 57% if MTB exhibits multiple antimicrobial resistance (AMR), for which fewer treatment options are available.
RESULTS
We develop a robust machine-learning classifier using both linear and nonlinear models (i.e. LASSO logistic regression (LR) and random forests (RF)) to predict the phenotypic resistance of Mycobacterium tuberculosis (MTB) for a broad range of antibiotic drugs. We use data from the CRyPTIC consortium to train our classifier, which consists of whole genome sequencing and antibiotic susceptibility testing (AST) phenotypic data for 13 different antibiotics. To train our model, we assemble the sequence data into genomic contigs, identify all unique 31-mers in the set of contigs, and build a feature matrix M, where M[i, j] is equal to the number of times the ith 31-mer occurs in the jth genome. Due to the size of this feature matrix (over 350 million unique 31-mers), we build and use a sparse matrix representation. Our method, which we refer to as MTB++, leverages compact data structures and iterative methods to allow for the screening of all the 31-mers in the development of both LASSO LR and RF. MTB++ is able to achieve high discrimination (F-1 >80%) for the first-line antibiotics. Moreover, MTB++ had the highest F-1 score in all but three classes and was the most comprehensive since it had an F-1 score >75% in all but four (rare) antibiotic drugs. We use our feature selection to contextualize the 31-mers that are used for the prediction of phenotypic resistance, leading to some insights about sequence similarity to genes in MEGARes. Lastly, we give an estimate of the amount of data that is needed in order to provide accurate predictions.
AVAILABILITY
The models and source code are publicly available on Github at https://github.com/M-Serajian/MTB-Pipeline.
Topics: Mycobacterium tuberculosis; Machine Learning; Drug Resistance, Bacterial; Microbial Sensitivity Tests; Anti-Bacterial Agents; Whole Genome Sequencing; Genome, Bacterial; Humans
PubMed: 38940175
DOI: 10.1093/bioinformatics/btae243 -
Annals of Agricultural and... Jun 2024Escherichia coli is one of the most common bacteria isolated from urine samples collected from dogs and cats with urinary tract infection (UTI). Uncomplicated UTIs in...
INTRODUCTION AND OBJECTIVE
Escherichia coli is one of the most common bacteria isolated from urine samples collected from dogs and cats with urinary tract infection (UTI). Uncomplicated UTIs in dogs and cats can be treated with short courses of first-line antimicrobial drugs, e.g. amoxicillin, amoxicillin with clavulanic acid, or trimethoprim/sulfonamide. Recurrent or complicated UTIs often require long-term treatment with broad-spectrum antibiotics. However, the choice of drug should be based on antimicrobial susceptibility.
MATERIAL AND METHODS
Between March - September 2022, E. coli isolates cultured from the urine of 66 dogs and 41 cats with UTI symptoms were tested for antimicrobial resistance by using Minimum Inhibitory Concentration (MIC). Antimicrobial susceptibility was tested for ampicillin, ampicillin/sulbactam, cefazolin, cefuroxime, aztreonam, gentamycin, amikacin, colistin, trimethoprim/sulfamethoxazole, ciprofloxacin, chloramphenicol and tetracycline.
RESULTS
The highest prevalence of resistance was documented for ampicillin (68% in dogs, 100% in cats) and ampicillin with sulbactam (59% in dogs, 54% in cats). The most common antimicrobial resistance patterns of E. coli were ampicillin alone (12 isolates, 29.3% in cats) and beta-lactams, including aztreonam (14 isolates, 21.2% in dogs).
CONCLUSIONS
High resistance to aztreonam (61% and 32% of isolates from dogs and cats, respectively), other beta-lactams, and fluoroquinolones should cause be alarm due to zoonotic potential and cross-transmission of antimicrobial-resistant microorganisms between animals and humans.
Topics: Dogs; Cats; Animals; Urinary Tract Infections; Cat Diseases; Escherichia coli; Dog Diseases; Anti-Bacterial Agents; Microbial Sensitivity Tests; Drug Resistance, Multiple, Bacterial; Escherichia coli Infections; Urinary Bladder; Female; Male
PubMed: 38940100
DOI: 10.26444/aaem/176843 -
Frontiers in Bioscience (Landmark... May 2024Lung cancer is the primary cause of cancer-related deaths, with one of the highest incidence and mortality rates of all malignant tumors. Dysregulated expression of...
BACKGROUND
Lung cancer is the primary cause of cancer-related deaths, with one of the highest incidence and mortality rates of all malignant tumors. Dysregulated expression of DEPDC1B has been reported to occur in various tumor types. However, the functional implications of this alteration in lung adenocarcinoma (LUAD) and the underlying molecular mechanism remains unclear. In this study, we investigated the role and clinical significance of DEPDC1B in LUAD.
METHODS
The expression of DEPDC1B in LUAD and its relationship with prognosis were systematically evaluated in several publically available datasets. The effects of DEPDC1B knockdown on the proliferation and motility of LUAD cells were assessed using the JULI Stage Real-time Cell History Recorder, while the effect of knockdown on the cell cycle was studied by flow cytometry. Furthermore, RNA-Sequencing (RNA-Seq) analysis was conducted to identify the downstream target genes and pathways regulated by DEPDC1B. Correlations between the expression of DEPDC1B and immune cell infiltration, immunotherapy resistance, and chemoresistance were also examined. Additionally, molecular biological methods were used to explore the regulatory mechanism of B-Myb on DEPDC1B expression.
RESULTS
DEPDC1B was found to be upregulated in LUAD patients and this was associated with poor clinical outcomes. Knockdown of inhibited cell growth, migration and motility, as well as cell cycle progression. Knockdown also resulted in the down-regulation of several downstream genes, including , , and , as well as the inactivation of multiple critical pathways, such as the ERK and PI3K-AKT pathways. Analysis of the tumor immuno-environment in LUAD revealed that high DEPDC1B expression was associated with an abundance of activated CD4+ memory T cells, M0 macrophages, M1 macrophages, and CD8+ T cells. Moreover, these tumors responded poorly to immunotherapy. Analysis of chemo-drug sensitivity showed that LUADs with high DEPDC1B expression were more responsive to frontline chemotherapeutic drugs such as Vinorelbine, Cisplatin, and Etoposide. Additionally, mechanistic investigations revealed that DEPDC1B is a direct target gene of B-Myb, and that its knockdown attenuated the proliferation and motility effects of B-Myb.
CONCLUSIONS
In summary, our findings indicate that DEPDC1B is a critical regulator during the malignant progression of LUAD. DEPDC1B could therefore be a promising prognostic marker and therapeutic target in LUAD diagnosis and treatment.
Topics: Humans; Adenocarcinoma of Lung; GTPase-Activating Proteins; Lung Neoplasms; Cell Proliferation; Cell Movement; Gene Expression Regulation, Neoplastic; Cell Line, Tumor; Disease Progression; Cell Cycle Proteins; Prognosis; Drug Resistance, Neoplasm; Male; Gene Knockdown Techniques; Signal Transduction; Neoplasm Proteins; Trans-Activators
PubMed: 38940035
DOI: 10.31083/j.fbl2906204 -
Journal of Extracellular Biology Feb 2024Epithelial-mesenchymal transition (EMT) is associated with tumorigenesis and drug resistance. The Rab superfamily of small G-proteins plays a role in regulating cell...
Epithelial-mesenchymal transition (EMT) is associated with tumorigenesis and drug resistance. The Rab superfamily of small G-proteins plays a role in regulating cell cytoskeleton and vesicle transport. However, it is not yet clear how the Rab family contributes to cancer progression by participating in EMT. By analysing various in silico datasets, we identified a statistically significant increase in expression in the oxaliplatin-resistant group compared to that in the parental or other chemotherapy drug groups. Our findings highlight powerful effect on colorectal cancer cell lines when compared with other family members. In a study that analysed multiple online meta-databases, RNA levels were continually detected in colorectal tissue arrays. Additionally, protein levels were correlated with various clinical parameters in clinical databases and were associated with negative prognoses for patients. expression levels in all three probes were calculated using a computer algorithm and were found to be positively correlated with EMT scores. The expression of the epithelial-type marker CDH1 was suppressed in overexpression models, whereas the expression of the mesenchymal-type markers SNAI1 and SNAI2 increased. Notably, -induced EMT and drug resistance are dependent on extracellular vesicle (EV) secretion. Interactome analysis confirmed that /AGR2 axis-mediated exocytosis was responsible for maintaining colorectal cell resistance to oxaliplatin. Our study concluded that alters the sensitivity of oxaliplatin, a supplementary chemotherapy approach, and is an independent prognostic factor that can be used in the treatment of colorectal cancer.
PubMed: 38939899
DOI: 10.1002/jex2.141 -
Biomaterials Research 2024The management of infected wounds poses a significant challenge due to the growing issue of antibiotic resistance, underscoring the urgent necessity to innovate and...
The management of infected wounds poses a significant challenge due to the growing issue of antibiotic resistance, underscoring the urgent necessity to innovate and implement alternative therapeutic strategies. These strategies should be capable of eliminating bacterial infections in infected wounds while circumventing the induction of multi-drug resistance. In the current study, we developed an easily prepared and injectable fibrin gel (FG) loaded with nanoparticles (NPs) that exhibit antibacterial and immunomodulatory properties to facilitate the healing of infected wounds. Initially, a novel type of NP was generated through the electrostatic interaction between the photothermal agent, mPEG-modified polydopamine (MPDA), and the nitric oxide (NO) donor, S-nitrosocysteamine (SNO). This interaction resulted in the formation of NPs referred to as SNO-loaded MPDA (SMPDA). Subsequently, the SMPDA was encapsulated into the FG using a double-barreled syringe, thereby producing the SMPDA-loaded FG (SMPDA/G). Experimental results revealed that SMPDA/G could effectively eliminate bacterial infections and alter the immune microenvironment. This efficacy is attributed to the synergistic combination of NO therapy and photothermal therapy, along with the role of SMPDA in facilitating M2 macrophage polarization within the gel. Accordingly, these findings suggest that the SMPDA/G holds substantial promise for clinical application in infected wound healing.
PubMed: 38938648
DOI: 10.34133/bmr.0019 -
Lung Cancer (Auckland, N.Z.) 2024The year 2024 is the 20 anniversary of the discovery of activating epidermal growth factor receptor () mutations in non-small cell lung cancer (NSCLC). Since then,...
Top 20 NSCLC Clinical and Translational Science Papers That Shaped the 20 Years Since the Discovery of Activating Mutations in NSCLC. An Editor-in-Chief Expert Panel Consensus Survey.
The year 2024 is the 20 anniversary of the discovery of activating epidermal growth factor receptor () mutations in non-small cell lung cancer (NSCLC). Since then, tremendous advances have been made in the treatment of NSCLC based on this discovery. Some of these studies have led to seismic changes in the concept of oncology research and spurred treatment advances beyond NSCLC, leading to a current true era of precision oncology for all solid tumors. We now routinely molecularly profile all tumor types and even plasma samples of patients with NSCLC for multiple actionable driver mutations, independent of patient clinical characteristics nor is profiling limited to the advanced incurable stage. We are increasingly monitoring treatment responses and detecting resistance to targeted therapy by using plasma genotyping. Furthermore, we are now profiling early-stage NSCLC for appropriate adjuvant targeted treatment leading to an eventual potential "cure" in early-stage NSCLC which have societal implication on implementing lung cancer screening in never-smokers as most NSCLC patients are never-smokers. All these advances were unfathomable in 2004 when the five papers that described "discoveries" of activating mutations (del19, L858R, exon 20 insertions, and "uncommon" mutations) were published. To commemorate this 20 anniversary, we assembled a global panel of thoracic medical oncology experts to select the top 20 papers (publications or congress presentation) from the 20 years since this seminal discovery with December 31, 2023 as the cutoff date for inclusion of papers to be voted on. Papers ranked 21 to 30 were considered "honorable mention" and also annotated. Our objective is that these 30 papers with their annotations about their impact and even all the ranked papers will serve as "syllabus" for the education of future thoracic oncology trainees. Finally, we mentioned potential practice-changing clinical trials to be reported. One of them, LAURA was published online on June 2, 2024 was not included in the list of papers to be voted on but will surely be highly ranked if this consensus survery is performed again on the 25 anniversay of the discovery mutations (i.e. top 25 papers on the 25 years since the discovery of activating mutations).
PubMed: 38938224
DOI: 10.2147/LCTT.S463429 -
Animal Bioscience Jun 2024This research aimed to analyze the prevalence, molecular characteristics, toxinotyping, alpha toxin production potential, and antibiotic resistance pattern of...
OBJECTIVE
This research aimed to analyze the prevalence, molecular characteristics, toxinotyping, alpha toxin production potential, and antibiotic resistance pattern of Clostridium perfringens (C. perfringens) isolates in meat samples collected from various sources.
METHODS
Sixty meat samples were screened for alpha toxin using Enzyme-Linked Immunosorbent Assay (ELISA), revealing a positivity rate of 13.3%, predominantly in raw poultry meat. Subsequent culturing on Perfringens agar identified nine samples harboring characteristic C. perfringens colonies, primarily isolated from raw poultry meat. Molecular confirmation through 16S rRNA gene amplification and sequencing authenticated twelve isolates as C. perfringens, with nine strains exhibiting genetic resemblance to locally isolated strains. Toxinotyping assays targeting alpha toxin-specific genes confirmed all nine isolates as type A C. perfringens, with no detection of beta or epsilon toxin genes. Hemolytic assays demonstrated varying alpha toxin production potentials among isolates, with accession number OQ721004.1 displaying the highest production capacity. Moreover, antibiotic resistance profiling revealed multi-drug resistance patterns among the isolates.
RESULTS
The study identified distinct clusters within C. perfringens strains, indicating variations. Phylogenetic analysis delineated genetic relatedness among strains, elucidating potential evolutionary paths and divergences.
CONCLUSION
The findings underscore the need for robust surveillance and control measures to mitigate the risk of C. perfringens contamination in meat products, particularly in raw poultry meat. Enhanced monitoring and prudent antimicrobial stewardship practices are warranted in both veterinary and clinical settings to address the observed antibiotic resistance profiles and prevent foodborne outbreaks.
PubMed: 38938034
DOI: 10.5713/ab.24.0210