Antimicrobial-resistant Pathogens Research Articles

How Should We Manage Antimicrobial Resistance in Resource-Limited Settings?

Patients living in low- and middle-income countries (LMICs) shoulder the greatest burden of infections caused by antimicrobial-resistant pathogens. Speedy access to appropriate broad-spectrum antimicrobials significantly improves health outcomes and reduces transmission of antimicrobial-resistant pathogens, but persons living in LMICs have compromised access to these antimicrobials. This article considers how inequities in microbiology diagnostics, antimicrobial access, and antimicrobial affordability influence outcomes for patients infected with antimicrobial-resistant pathogens who live in resource-limited settings.

How Should Health Care Respond to Threats Antimicrobial Resistance Poses to Workers?

Antimicrobial resistance (AMR) is a looming pandemic whose poor health outcomes are unlikely to be equitably distributed. This article focuses on intersections between AMR and inequities in health care workplaces in the United States and identifies the following as key problems: lack of published data on task-specific occupational health risks related to colonization and infection with antimicrobial-resistant pathogens, limited scientific literature reporting on race and ethnicity, and poor access to infection control educational opportunities for minoritized health care workers. This article argues that an equitable approach to remediating these problems requires improving surveillance and expanding research on how AMR is likely to influence health outcomes among members of the US-based health care workforce.

WGS analysis of hypervirulent and MDR Klebsiella pneumoniae from Vietnam reveales an inverse relationship between resistome and virulome

The emergence of Klebsiella (K.) pneumoniae as a leading cause of nosocomial infections in Southeast Asia is of concern. Vietnam has an outstanding position with regard to antimicrobial-resistant (AMR) pathogens and is a hotspot for carbapenem-resistant K. pneumoniae. In the current study, 19 clinical K. pneumoniae strains isolated from patients in Vietnam were tested for antibiotic susceptibility, and their genome sequences were analyzed to investigate potential resistance profiles, genotypes, AMR determinants, and virulence-associated genes. More than half of the isolates were multidrug-resistant (MDR), displaying resistance to ciprofloxacin, levofloxacin, chloramphenicol, piperacillin, cefotaxime, ceftazidime, and cefepime. Carbapenem- resistance was detected in 47% (n=9) of isolates. Five isolates were assigned to sequence type (ST) 23 by multi-locus sequence typing (MLST). These ST23 strains exhibited determinants characteristic of hypervirulent strains and were sensitive to all antibiotics tested except for one strain, which was resistant to chloramphenicol and trimethoprim/sulfamethoxazole. All isolates had AMR determinants that conferred resistance to aminoglycosides and ß-lactams. Single nucleotide variants of oqxA and oqxB conferring resistance to phenicol/quinolone, ompK37 and ompA conferring resistance to beta-lactams, and lptD conferring resistance to rifamycin, were found in all isolates. Additionally, 95% of the isolates (n=18) carried fosA genes; however, only two were resistant to fosfomycin. Five isolates carried genes conferring resistance to colistin; only one carried mcr-1.1 and showed resistance to colistin. One hundred thirty virulence-associated genes were identified. The current study demonstrated an inverse relationship between the number of detected virulence determinants and antibiotic resistance. Several well-known resistance genes have been identified but did not mediate resistance, which could be due to insufficient levels or lack of expression. A comprehensive study of the genotypic findings of AMR determinants and virulence with phenotypic data is required. The presence of hypervirulent K. pneumoniae carrying specific virulomes is a growing problem, and monitoring of virulence characteristics of K. pneumoniae is important.

Tackling carbapenem resistance: ceftazidime - avibactam in contemporary clinical scenarios

Antimicrobial resistance poses a formidable challenge in treating severe infections, with the prevalence of extended-spectrum beta-lactamase (ESBL) - producing, Klebsiella pneumoniae carbapenemase (KPC) - producing, and multidrug-resistant (MDR) organisms on the rise. This necessitates careful consideration of various factors, including local resistance patterns, patient-specific characteristics, and drug properties, in treatment decisions for critically ill patients. Ceftazidime-Avibactam demonstrates efficacy against aerobic Gram-negative bacteria and offers a crucial advancement against carbapenem-resistant organisms (CRO) with its effectiveness against key pathogens, including ESBL, AmpC, KPC, and OXA-48-producing Enterobacteriaceae and drug-resistant P. aeruginosa. Ceftazidime-Avibactam emerges as a valuable option for critically ill patients with limited treatment choices. The drug's excellent safety profile demonstrated in clinical trials, further positions it as a crucial addition to antimicrobial treatment options. As the global threat of drug-resistant bacteria grows, Ceftazidime-Avibactam plays a pivotal role in addressing this challenge and offers a promising solution for critically ill patients facing infections caused by antimicrobial-resistant pathogens. The article delves into therapeutic efficacy and the prospective role of Ceftazidime-Avibactam in managing MDR Gram-negative organisms, underscoring the critical role of appropriate antibiotic administration in reducing mortality associated with Gram-negative infections.

Stray Dogs (Mongrels) Are Potent Reservoir of Drug-Resistant Pathogens: A Study in Peri-Urban Areas of Kolkata, India.

This study depicts the drug-resistance and phylogenomic characteristics of 365 Escherichia coli (EC) and 76 Klebsiella pneumoniae (KP) isolated from stray dogs (293) in and around Kolkata, India. Initial screening found 59 isolates, including 48 E. coli and 11 KP multidrug resistant, which included 33 extended-spectrum β-lactamase, 41 AmpC β-lactamase and 18 metallo-β-lactamase producers carrying blaNDM-1 (11) and blaNDM-5 (7) genes. Majority of them had the resistant genes such as blaCTX-M (33), blaTEM (18), blaSHV (4), blaOXA (17), blaFOX (2), blaDHA (2), blaCITM (15), blaCMY-2 (13), blaGES (2) and blaVEB (2), qnrS (15), qnrB (3), aac-6'-Ib-cr (14), tetA (26), tetB (14), sul-1 (25), armA (2) and rmtB (6), in addition to adherence genes such as csgA (33), fimA (27), fliC (13), sdiA (33), rcsA (38), and rpoS (39). They also carried plasmid of diverse replicon types of which IncFIA and FIB were the most frequent. Phylogrouping categorized most of the MDR E. coli in phylogroup A (20), B1 (14), and B2 (6). Enterobacteriaceae repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) showed genetic diversity of multidrug resistant isolates irrespective of their origin, resistance, and virulence types, differentiating the EC in five clades (A-E) and KP in four clades (A-D). As these stray dogs, which had no history or scope of previous antimicrobial therapy, were found to have contracted potential antimicrobial resistance pathogens, the role of environment in spread of such pathogens and further possibility of human infections cannot be ruled out.

Unitig-centered pan-genome machine learning approach for predicting antibiotic resistance and discovering novel resistance genes in bacterial strains

In current genomic research, the widely used methods for predicting antimicrobial resistance (AMR) often rely on prior knowledge of known AMR genes or reference genomes. However, these methods have limitations, potentially resulting in imprecise predictions owing to incomplete coverage of AMR mechanisms and genetic variations. To overcome these limitations, we propose a pan-genome-based machine learning approach to advance our understanding of AMR gene repertoires and uncover possible feature sets for precise AMR classification. By building compacted de Brujin graphs (cDBGs) from thousands of genomes and collecting the presence/absence patterns of unique sequences (unitigs) for Pseudomonas aeruginosa, we determined that using machine learning models on unitig-centered pan-genomes showed significant promise for accurately predicting the antibiotic resistance or susceptibility of microbial strains. Applying a feature-selection-based machine learning algorithm led to satisfactory predictive performance for the training dataset (with an area under the receiver operating characteristic curve (AUC) of > 0.929) and an independent validation dataset (AUC, approximately 0.77). Furthermore, the selected unitigs revealed previously unidentified resistance genes, allowing for the expansion of the resistance gene repertoire to those that have not previously been described in the literature on antibiotic resistance. These results demonstrate that our proposed unitig-based pan-genome feature set was effective in constructing machine learning predictors that could accurately identify AMR pathogens. Gene sets extracted using this approach may offer valuable insights into expanding known AMR genes and forming new hypotheses to uncover the underlying mechanisms of bacterial AMR.

[A cross-sectional study on the pathogen composition and antimicrobial resistance in neonates with sepsis in Hebei Province, China].

To study the pathogen composition and antimicrobial resistance characteristics in neonates with sepsis in the Hebei area, providing a basis for optimizing the management strategies for neonatal sepsis in the region. The medical data of neonates with sepsis confirmed by blood culture from 23 hospitals in Hebei Province were collected prospectively from November 1, 2021 to December 31, 2022. The pathogen composition and antimicrobial resistance characteristics were analyzed in early-onset sepsis (EOS), community-acquired late-onset sepsis (CALOS), and hospital-acquired late-onset sepsis (HALOS) cases. A total of 289 neonates were included, accounting for 292 infection episodes, with 117 (40.1%) EOS, 95 (32.5%) CALOS, and 80 (27.4%) HALOS cases. A total of 294 pathogens were isolated, with 118 (40.1%) from the EOS group, where Escherichia coli (39 strains, 33.0%) and coagulase-negative staphylococci (13 strains, 11.0%) were the most common. In the CALOS group, 95 pathogens were isolated (32.3%), with Escherichia coli (35 strains, 36.8%) and group B Streptococcus (14 strains, 14.7%) being predominant. The HALOS group yielded 81 isolates (27.6%), with Klebsiella pneumoniae (24 strains, 29.6%) and Escherichia coli (21 strains, 25.9%) as the most frequent. Coagulase-negative staphylococci showed over 80% resistance to penicillin antibiotics. Escherichia coli and Klebsiella pneumoniae showed a resistance rate of 2.2% to 75.0% to common β-lactam antibiotics. The resistance rates of predominant Gram-negative bacteria in the HALOS group to common β-lactam antibiotics were higher than those in the CALOS group. In the Hebei region, Escherichia coli is the most common pathogen in both EOS and LOS. There are differences in the composition and antimicrobial resistance of pathogens among different types of neonatal sepsis. The choice of empirical antimicrobial drugs should be based on the latest surveillance data from the region.

Modulating the antibacterial effect of the existing antibiotics along with repurposing drug metformin.

Owing to the extensive prevalence of resistant bacteria to numerous antibiotic classes, antimicrobial resistance (AMR) poses a well-known hazard to world health. As an alternate approach in the field of antimicrobial drug discovery, repurposing the available medications which are also called antibiotic resistance breakers has been pursued for the treatment of infections with antimicrobial resistance pathogens. In this study, we used Haloperidol, Metformin and Hydroxychloroquine as repurposing drugs in in vitro (Antibacterial Antibiotic Sensitivity Test and Minimum Inhibitory Concentration-MIC) and in vivo (Shigellosis in Swiss albino mice) tests in combination with traditional antibiotics (Oxytetracycline, Erythromycin, Doxycycline, Gentamicin, Ampicillin, Chloramphenicol, and Penicillin) against a group of AMR resistance bacteria (Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Shigella boydii). After observing the results of the conducted in vitro experiments we studied the effects of the above non antibiotic drugs in combination with the said antibiotics. As an repurposing adjuvant antibiotic drug, Metformin exhibited noteworthy activity in almost all in vitro, in vivo and in silico tests (Zone of inhibition for 30 to 43mm for E.coli in combination with Doxycycline; MIC value decreased 50 µM to 0.781 µM with Doxycycline on S. boydii).In rodents Doxycycline and Metformin showed prominent against Shigellosis in White blood cell count (6.47 ± 0.152 thousand/mm3) and Erythrocyte sedimentation rate (10.5 ± 1.73mm/hr). Our findings indicated that Metformin and Doxycycline combination has a crucial impact on Shigellosis. The molecular docking study was performed targeting the Acriflavine resistance protein B (AcrB) (PDB ID: 4CDI) and MexA protein (PDB ID: 6IOK) protein with Metformin (met8) drug which showed the highest binding energy with - 6.4kcal/mol and - 5.5kcal/mol respectively. Further, molecular dynamics simulation revealed that the docked complexes were relatively stable during the 100 ns simulation period. This study suggest Metformin and other experimented drugs can be used as adjuvants boost up antibiosis but further study is needed to find out the safety and efficacy of this non-antibiotic drug as potent antibiotic adjuvant.

Clinical and genomic characteristics of IMP-producing Enterobacter cloacae complex and Klebsiella pneumoniae.

Carbapenemase-producing Enterobacterales (CPEs) are one of the top priority antimicrobial-resistant pathogens. Among CPEs, those producing acquired metallo-β-lactamases (MBLs) are considered particularly problematic as few agents are active against them. Imipenemase (IMP) is the most frequently encountered acquired MBL in Japan, but comprehensive assessment of clinical and microbiological features of IMP-producing Enterobacterales infection remains scarce. Here, we retrospectively evaluated 62 patients who were hospitalized at a university hospital in Japan and had IMP-producing Enterobacterales from a clinical culture. The isolates were either Enterobacter cloacae complex or Klebsiella pneumoniae, and most of them were isolated from sputum. The majority of K. pneumoniae, but not E. cloacae complex isolates, were susceptible to aztreonam. Sequence type (ST) 78 and ST517 were prevalent for E. cloacae complex and K. pneumoniae, respectively, and all isolates carried blaIMP-1. Twenty-four of the patients were deemed infected with IMP-producing Enterobacterales. Among the infected patients, therapy varied and largely consisted of conventional β-lactam agents, fluoroquinolones, or combinations. Three (13%), five (21%), and nine (38%) of them died by days 14, 30, and 90, respectively. While incremental mortality over 90 days was observed in association with underlying comorbidities, active conventional treatment options were available for most patients with IMP-producing Enterobacterales infections, distinguishing them from more multidrug-resistant CPE infections associated with globally common MBLs, such as New Delhi metallo-β-lactamase (NDM) and Verona integron-encoded metallo-β-lactamase (VIM).

Private and well drinking water are reservoirs for antimicrobial resistant bacteria

Water quality testing does not recognise antimicrobial resistance (AMR) and is often limited to indicators of faecal contamination Escherichia coli and Enterococcus species. In Europe, data on AMR in drinking water is scarce. In Ireland, as in many countries, household drinking water is supplied via mains or via private wells or water schemes. Using citizen science, we identified Irish private drinking water supplies as reservoirs of antimicrobial resistant bacteria (ARB). Gram-negative (n = 464) and Gram-positive (n = 72) bacteria were isolated. We identified instances of potentially opportunistic ARB such as Enterobacter cloacae, Acinetobacter baumannii and Enterococcus species. We report reservoirs of multidrug resistance in Enterococcus casseliflavus, E. cloacae, E. coli, Stenotrophomonas maltophilia, and Serratia rubidaea. We also identified linezolid-resistant Enterococcus in Irish drinking water. Linezolid is a last-resort antibiotic used to treat vancomycin-resistant Enterococcus sp. Additionally, we identified mobile AMR in three water samples, two of which were carried on IncF group, one on IncQ and five on Col-like plasmids. Our work suggests that private drinking water is a potential sink and source of AMR pathogens. This highlights a value of drinking water surveillance in a One Health framework as the surveillance would provide information regarding the movement and persistence of ARB and ARGs that are able to survive in drinking water and subsequently have the opportunity to be mobilised through humans; linking the environment to the human and potentially threatening human health.

Potential of the quorum-quenching and plant-growth promoting halotolerant Bacillus toyonensis AA1EC1 as biocontrol agent.

The use of fertilizers and pesticides to control plant diseases is widespread in intensive farming causing adverse effects together with the development of antimicrobial resistance pathogens. As the virulence of many Gram-negative phytopathogens is controlled by N-acyl-homoserine lactones (AHLs), the enzymatic disruption of this type of quorum-sensing (QS) signal molecules, mechanism known as quorum quenching (QQ), has been proposed as a promising alternative antivirulence therapy. In this study, a novel strain of Bacillus toyonensis isolated from the halophyte plant Arthrocaulon sp. exhibited numerous traits associated with plant growth promotion (PGP) and degraded a broad range of AHLs. Three lactonases and an acylase enzymes were identified in the bacterial genome and verified invitro. The AHL-degrading activity of strain AA1EC1 significantly attenuated the virulence of relevant phytopathogens causing reduction of soft rot symptoms on potato and carrots. Invivo assays showed that strain AA1EC1 significantly increased plant length, stem width, root and aerial dry weights and total weight of tomato and protected plants against Pseudomonas syringae pv. tomato. To our knowledge, this is the first report to demonstrate PGP and QQ activities in the species B. toyonensis that make this strain as a promising phytostimulant and biocontrol agent.

Genomic Characterization of Multidrug-Resistant Pathogenic Enteric Bacteria from Healthy Children in Osun State, Nigeria.

Antimicrobial resistance (AMR) is responsible for the spread and persistence of bacterial infections. Surveillance of AMR in healthy individuals is usually not considered, though these individuals serve as reservoirs for continuous disease transmission. Therefore, it is essential to conduct epidemiological surveillance of AMR in healthy individuals to fully understand the dynamics of AMR transmission in Nigeria. Thirteen multidrug-resistant Citrobacter spp., Enterobacter spp., Klebsiella pneumoniae, and Escherichia coli isolated from stool samples of healthy children were subjected to whole genome sequencing (WGS) using Illumina and Oxford nanopore sequencing platforms. A bioinformatics analysis revealed antimicrobial resistance genes such as the pmrB_Y358N gene responsible for colistin resistance detected in E. coli ST219, virulence genes such as senB, and ybtP&Q, and plasmids in the isolates sequenced. All isolates harbored more than three plasmid replicons of either the Col and/or Inc type. Plasmid reconstruction revealed an integrated tetA gene, a toxin production caa gene in two E. coli isolates, and a cusC gene in K. quasivariicola ST3879, which induces neonatal meningitis. The global spread of AMR pathogenic enteric bacteria is of concern, and surveillance should be extended to healthy individuals, especially children. WGS for epidemiological surveillance will improve the detection of AMR pathogens for management and control.

Bacillus amyloliquefaciens Probiotics Mix Supplementation in a Broiler Leaky Gut Model.

The supplementation of antimicrobial growth promoters (AGPs) has been banned in many countries because of the emergence of antimicrobial-resistant pathogens in poultry products and the environment. Probiotics have been broadly studied and demonstrated as a promising AGP substitute. Our study is centred on the effects of a multi-strain Bacillus-based probiotic product on broiler production performance and gut microbial profile in a dexamethasone-induced leaky gut challenge. Two hundred and fifty-six broiler chicks were hatched and randomly assigned into four groups (wheat-soybean meal basal diet (BD) = non-supplemented control (C), BD supplemented with dexamethasone in week 4 (CD), BD containing a probiotic from day one (P), and BD containing a probiotic from day one and supplemented with dexamethasone during challenge week 4 (PD)). The production performance and caecal, gizzard, jejunal lumen and jejunal mucosa swab microbiota were studied by 16S rRNA gene sequencing. The Bacillus probiotic product significantly improved production performance and altered caecal gut microbiota (p ≤ 0.05), but no significant impact on microbiota was observed in other gut sections.

Cerebrospinal Pharmacokinetic Analysis and Pharmacodynamic Evaluation of Ceftriaxone in Pediatric Patients with Bacterial Meningitis

What Is Known? and Objective. Ceftriaxone has been widely used to treat bacterial meningitis in pediatric patients. Ceftriaxone dosing regimens of 80–120 mg/kg/day have been recommended for bacterial meningitis in pediatric patients, and the usual duration of therapy is 7–14 days. Although the target site for meningitis is cerebrospinal fluid (CSF), a CSF pharmacokinetic (PK) model in pediatric patients has not been reported. We aimed to develop a CSF PK model of ceftriaxone, using not only serum but also CSF concentration data, and to evaluate the appropriateness of dosing regimens for pediatric patients with bacterial meningitis. Methods. The population PK model was developed by simultaneously fitting serum and CSF data from pediatric patients described in nine published articles. Probabilities of attaining a pharmacodynamic target (100% T > MIC, 100% of time that drug concentrations above the minimum inhibitory concentration) in CSF were estimated for some dosing regimens. Results and Discussion. Twenty-four pediatric patients with meningitis were the subjects for PK modeling (0.52–13 years old, and 3.5–50 kg of body weight). Sixty-eight serum concentrations and 98 CSF samples were used to develop the CSF PK model. The CSF/serum concentration ratio at the same sampling time was 0.0628 ± 0.0689. Age was not a statistically significant covariate in the PK parameter. In the CSF PK model, 40–60 mg/kg q12 h achieved a target attainment probability >90% against causative bacteria for bacterial meningitis. However, 4-h infusion (rather than 0.5-h infusion) dosing regimens were required for efficacy against antimicrobial-resistant bacteria with high MICs. What Is New? and Conclusion. Ceftriaxone-dosing regimens with prolonged infusion times might be reasonably effective for treating antimicrobial-resistant pathogens in empiric therapy.

Genome-centric analyses of 165 metagenomes show that mobile genetic elements are crucial for the transmission of antimicrobial resistance genes to pathogens in activated sludge and wastewater.

Antimicrobial resistance (AMR) threatens the health of humans, animals, and natural ecosystems. In our study, an analysis of 165 metagenomes from wastewater revealed antibiotic-targeted alteration, efflux, and inactivation as the most prevalent AMR mechanisms. We identified several genera correlated with multiple ARGs, including Klebsiella, Escherichia, Acinetobacter, Nitrospira, Ottowia, Pseudomonas, and Thauera, which could have significant implications for AMR transmission. The abundance of bacA, mexL, and aph(3")-I in the genomes calls for their urgent management in wastewater. Our approach could be applied to different ecosystems to assess the risk of potential pathogens containing ARGs. Our findings highlight the importance of managing AMR in wastewater and can help design measures to reduce the transmission and evolution of AMR in these systems.

Non-canonical amino acid bioincorporation into antimicrobial peptides and its challenges.

The rise of antimicrobial resistance and multi-drug resistant pathogens has necessitated explorations for novel antibiotic agents as the discovery of conventional antibiotics is becoming economically less viable and technically more challenging for biopharma. Antimicrobial peptides (AMPs) have emerged as a promising alternative because of their particular mode of action, broad spectrum and difficulty that microbes have in becoming resistant to them. The AMPs bacitracin, gramicidin, polymyxins and daptomycin are currently used clinically. However, their susceptibility to proteolytic degradation, toxicity profile, and complexities in large-scale manufacture have hindered their development. To improve their proteolytic stability, methods such as integrating non-canonical amino acids (ncAAs) into their peptide sequence have been adopted, which also improves their potency and spectrum of action. The benefits of ncAA incorporation have been made possible by solid-phase peptide synthesis. However, this method is not always suitable for commercial production of AMPs because of poor yield, scale-up difficulties, and its non-'green' nature. Bioincorporation of ncAA as a method of integration is an emerging field geared towards tackling the challenges of solid-phase synthesis as a green, cheaper, and scalable alternative for commercialisation of AMPs. This review focusses on the bioincorporation of ncAAs; some challenges associated with the methods are outlined, and notes are given on how to overcome these challenges. The review focusses particularly on addressing two key challenges: AMP cytotoxicity towards microbial cell factories and the uptake of ncAAs that are unfavourable to them. Overcoming these challenges will draw us closer to a greater yield and an environmentally friendly and sustainable approach to make AMPs more druggable.

Modeling the limits of detection for antimicrobial resistance genes in agri-food samples: a comparative analysis of bioinformatics tools

BackgroundAlthough the spread of antimicrobial resistance (AMR) through food and its production poses a significant concern, there is limited research on the prevalence of AMR bacteria in various agri-food products. Sequencing technologies are increasingly being used to track the spread of AMR genes (ARGs) in bacteria, and metagenomics has the potential to bypass some of the limitations of single isolate characterization by allowing simultaneous analysis of the agri-food product microbiome and associated resistome. However, metagenomics may still be hindered by methodological biases, presence of eukaryotic DNA, and difficulties in detecting low abundance targets within an attainable sequence coverage. The goal of this study was to assess whether limits of detection of ARGs in agri-food metagenomes were influenced by sample type and bioinformatic approaches.ResultsWe simulated metagenomes containing different proportions of AMR pathogens and analysed them for taxonomic composition and ARGs using several common bioinformatic tools. Kraken2/Bracken estimates of species abundance were closest to expected values. However, analysis by both Kraken2/Bracken indicated presence of organisms not included in the synthetic metagenomes. Metaphlan3/Metaphlan4 analysis of community composition was more specific but with lower sensitivity than the Kraken2/Bracken analysis. Accurate detection of ARGs dropped drastically below 5X isolate genome coverage. However, it was sometimes possible to detect ARGs and closely related alleles at lower coverage levels if using a lower ARG-target coverage cutoff (< 80%). While KMA and CARD-RGI only predicted presence of expected ARG-targets or closely related gene-alleles, SRST2 (which allows read to map to multiple targets) falsely reported presence of distantly related ARGs at all isolate genome coverage levels. The presence of background microbiota in metagenomes influenced the accuracy of ARG detection by KMA, resulting in mcr-1 detection at 0.1X isolate coverage in the lettuce but not in the beef metagenome.ConclusionsThis study demonstrates accurate detection of ARGs in synthetic metagenomes using various bioinformatic methods, provided that reads from the ARG-encoding organism exceed approximately 5X isolate coverage (i.e. 0.4% of a 40 million read metagenome). While lowering thresholds for target gene detection improved sensitivity, this led to the identification of alternative ARG-alleles, potentially confounding the identification of critical ARGs in the resistome. Further advancements in sequencing technologies providing increased coverage depth or extended read lengths may improve ARG detection in agri-food metagenomic samples, enabling use of this approach for tracking clinically important ARGs in agri-food samples.

Phytochemical Analysis and Antimicrobial Activity of Pongamia Pinnata: A Comprehensive Study

Background: Antimicrobial resistance (AMR) poses a significant global health challenge, exacerbated by the misuse of antimicrobial agents. With the rising prevalence of AMR in various plant and animal pathogens, there is an urgent need to explore alternative therapeutic options. Plant extracts, historically utilized for disease treatment, offer a promising avenue. Pongamia pinnata, also known as Indian Karanja, is notable for its rich phytochemical content and has been the subject of recent scientific interest. Objective: The primary aim of this study is to investigate the antimicrobial efficacy of P. pinnata extracts, prepared using the Ultrasonic Assisted Extraction (UAE) method, against a range of bacterial and fungal species known to exhibit AMR. Methods: In this study, an experimental laboratory design was utilized to evaluate the antimicrobial properties of Pongamia pinnata. Aqueous and alcoholic extracts of P. pinnata were prepared and subjected to biochemical analysis to identify the spectrum of phytochemicals present. The antimicrobial activity of these extracts was then assessed using the well-diffusion method against selected bacterial and fungal pathogens. Results: Both aqueous and alcoholic extracts of P. pinnata demonstrated significant antimicrobial effects against the tested microbial species. The study highlights the potent antimicrobial properties of P. pinnata, attributed to its diverse phytochemical composition. Conclusion: The findings of this study underscore P. pinnata as a valuable source of natural antimicrobial agents. Its efficacy against AMR pathogens suggests its potential application in the development of new treatments for infectious diseases. P. pinnata holds promise for medicinal use, particularly in contexts where conventional antibiotics are ineffective.

Antimicrobial-resistant pathogens in fruits and vegetables from retail and home gardens

Abstract Fruits and vegetables have been identified as vehicles for the transmission of pathogenic antimicrobial-resistant (AMR) microorganisms. This is of food safety concern, thus requiring continuous surveillance. This study aimed to profile AMR bacteria present in selected fruits and vegetables retailed in markets and from home gardens (HGs) in Oyo, Ogun, and Ekiti states, Nigeria. Watermelon, cucumber, tomato, and garden egg samples were collected and analyzed using standard microbiological procedures. The susceptibility of the isolates to eight antibiotics was determined. Multidrug-resistant isolates were screened for the presence of AMR genes by polymerase chain reaction. Fifty three bacteria were isolated and identified, belonging to the genera Bacillus, Corynebacterium, Listeria, Aeromonas, Enterobacter, Erwinia, Salmonella, Serratia, Shigella, and Vibrio. Thirty six (67.93%) isolates demonstrated phenotypic resistance to five of the eight antibiotics tested, being the most prevalent pattern observed. BlaTEM and blaCTX-M were detected in Salmonella enterica from retailed tomato, blaTEM, blaSHV, blaCTX-M, and erm(B) were detected in Listeria monocytogenes from retailed watermelon, blaSHV and blaCTX-M were detected in Bacillus cereus from retailed tomato, while blaTEM, blaSHV, blaCTX-M, and erm(F) were detected in Staphylococcus aureus isolated in garden egg from HG. The presence of multidrug-resistant pathogens in fruits and vegetables could pose a huge food safety and public health risk.

Detection of imported clinical strain of blaNDM-1-harbouring ST147 Klebsiella pneumoniae from a Ukrainian immigrant.

We have isolated a blaNDM-1-harbouring ST147 Klebsiella pneumoniae strain from a Ukrainian immigrant hospitalized at a Japanese hospital, which was genetically corroborated to be highly identical to a Russian-derived isolate. This case highlights that the geopolitical risk potentially increases the global dissemination of antimicrobial resistance pathogens.