Spread Of Multidrug-resistant Research Articles

The expression of integron arrays is shaped by the translation rate of cassettes

Integrons are key elements in the rise and spread of multidrug resistance in Gram-negative bacteria. These genetic platforms capture cassettes containing promoterless genes and stockpile them in arrays of variable length. In the current integron model, expression of cassettes is granted by the Pc promoter in the platform and is assumed to decrease as a function of its distance. Here we explored this model using a large collection of 136 antibiotic resistance cassettes and show the effect of distance is in fact negligible. Instead, cassettes have a strong impact in the expression of downstream genes because their translation rate affects the stability of the whole polycistronic mRNA molecule. Hence, cassettes with reduced translation rates decrease the expression and resistance phenotype of cassettes downstream. Our data puts forward an integron model in which expression is contingent on the translation of cassettes upstream, rather than on the distance to the Pc.

New strategies to enhance antimicrobial photo-sonodynamic therapy based on nanosensitizers against bacterial infections.

The rapid evolution and spread of multidrug resistance among bacterial pathogens has significantly outpaced the development of new antibiotics, underscoring the urgent need for alternative therapies. Antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy have emerged as promising treatments. Antimicrobial photodynamic therapy relies on the interaction between light and a photosensitizer to produce reactive oxygen species, which are highly cytotoxic to microorganisms, leading to their destruction without fostering resistance. Antimicrobial sonodynamic therapy, a novel variation, substitutes ultrasound for light to activate the sonosensitizers, expanding the therapeutic reach. To increase the efficiency of antimicrobial photodynamic therapy and antimicrobial sonodynamic therapy, the combination of these two methods, known as antimicrobial photo-sonodynamic therapy, is currently being explored and considered a promising approach. Recent advances, particularly in the application of nanomaterials, have further enhanced the efficacy of these therapies. Nanosensitizers, due to their improved reactive oxygen species generation and targeted delivery, offer significant advantages in overcoming the limitations of conventional sensitizers. These breakthroughs provide new avenues for treating bacterial infections, especially multidrug-resistant strains and biofilm-associated infections. Continued research, including comprehensive clinical studies, is crucial to optimizing nanomaterial-based antimicrobial photo-sonodynamic therapy for clinical use, ensuring their effectiveness in real-world applications.

Beijing Central Asian Outbreak strain cluster of Mycobacterium tuberculosis detected in Irkutsk region, Russia

Background. Irkutsk region maintains a high incidence rate of multidrug-resistant (MDR) tuberculosis (TB). Detection of MDR-associated Mycobacterium tuberculosis strains in Irkutsk region requires dynamic assessment of the TB pathogen population, taking into account the emergence of a new resistant variant of Beijing Central Asian Outbreak (CAO).The aim of the study. To assess changes in the genotypic structure of M. tuberculosis strains circulating in the Irkutsk region over a ten-year period.Materials and methods. A total of 732 M. tuberculosis strains (196 strains for 2021– 2022, 536 strains for 2011–2015) were studied using MIRU-VNTR and SNP typing.Results. The MDR level increased to 67.4 % with an increase of pre-extensive drug resistance (pre-XDR) (33.2 %) (p < 0.001). In the modern sample, the dominance of the Beijing genotype increased (83.7 %) due to an increase in the proportions of the B0/W148 (38.8 %) and CAO (12.8 %) subtypes with a stable overall level of Central Asian Russian (36.8 %) and other Beijing strains (8.2 %). Strains other than the Beijing genotype belonged mainly to the Euro-American lineage (Lineage 4): LAM (8.9 %), Ural (2.7 %), Haarlem (2.0 %), S (0.5 %) and L4-unclassified (5.3 %); 25 isolates were not classified. In the 2011–2015 sample, LAM was more common than in the modern sample (10.8 % vs. 3.6 %; p < 0.01). The increase in MDR and preXDR was statistically significant among Beijing B0/W148 strains (93.4 % vs. 66.1 %; p < 0.001).Conclusion. Unfavorable trends of significant spread of MDR and pre-XDR of the Beijing genotype strains were revealed. Among the Beijing strains, not only B0/W148 but also the Beijing CAO subtype, which was previously rare in Siberia, are the most successful; they have the highest levels of MDR and pre-XDR and a tendency to widespread distribution in all groups of TB patients.

Beyond Antibiotics: What the Future Holds.

The prevalence of multidrug resistance (MDR) and stagnant drug-development pipelines have led to the rapid rise of hard-to-treat antibiotic-resistant bacterial infections. These infectious diseases are no longer just nosocomial but are also becoming community-acquired. The spread of MDR has reached a crisis level that needs immediate attention. The landmark O'Neill report projects that by 2050, mortality rates associated with MDR bacterial infections will surpass mortality rates associated with individuals afflicted with cancer. Since conventional antimicrobials are no longer very reliable, it is of great importance to investigate different strategies to combat these life-threatening infectious diseases. Here, we provide an overview of recent advances in viable alternative treatment strategies mainly targeting a pathogen's virulence capability rather than viability. Topics include small molecule and immune inhibition of virulence factors, quorum sensing (QS) quenching, inhibition of biofilm development, bacteriophage-mediated therapy, and manipulation of an individual's macroflora to combat MDR bacterial infections.

Coexistence of plasmid-mediated tmexCD2-toprJ2, blaIMP-4, and blaNDM-1 in Klebsiella quasipneumoniae.

Klebsiella quasipneumoniae is a potential pathogen that has not been studied comprehensively. The emergence of multidrug-resistant (MDR) K. quasipneumoniae, specifically strains resistant to tigecycline and carbapenem, presents a significant challenge to clinical treatment. This investigation aimed to characterize MDR K. quasipneumoniae strain FK8966, co-carrying tmexCD2-toprJ2, blaIMP-4, and blaNDM-1 by plasmids. It was observed that FK8966's MDR was primarily because of the IncHI1B-like plasmid co-carrying tmexCD2-toprJ2 and blaIMP-4, and an IncFIB(K)/IncFII(K) plasmid harboring blaNDM-1. Furthermore, the phylogenetic analysis revealed that IncHI1B-like plasmids carrying tmexCD2-toprJ2 were disseminated among different bacteria, specifically in China. Additionally, according to the comparative genomic analysis, the MDR regions indicated that the tmexCD2-toprJ2 gene cluster was inserted into the umuC gene, while blaIMP-4 was present in transposon TnAs3 linked to the class 1 integron (IntI1). It was also observed that an ΔTn3000 insertion with blaNDM-1 made a novel blaNDM-1 harboring IncFIB(K)/IncFII(K) plasmid. The antimicrobial resistance prevalence and phylogenetic analyses of K. quasipneumoniae strains indicated that FK8966 is a distinct MDR branch of K. quasipneumoniae. Furthermore, CRISPR-Cas system analysis showed that many K. quasipneumoniae CRISPR-Cas systems lacked spacers matching the two aforementioned novel resistance plasmids, suggesting that these resistance plasmids have the potential to disseminate within K. quasipneumoniae. Therefore, the spread of MDR K. quasipneumoniae and plasmids warrants further attention.IMPORTANCEThe emergence of multidrug-resistant K. quasipneumoniae poses a great threat to clinical care, and the situation is exacerbated by the dissemination of tigecycline- and carbapenem-resistant genes. Therefore, monitoring these pathogens and their resistance plasmids is urgent and crucial. This study identified tigecycline- and carbapenem-resistant K. quasipneumoniae strain, FK8966. Furthermore, it is the first study to report the coexistence of tmexCD2-toprJ2, blaIMP-4, and blaNDM-1 in K. quasipneumoniae. Moreover, the CRISPR-Cas system of many K. quasipneumoniae lacks spacers that match the plasmids carried by FK8966, which are crucial for mediating resistance against tigecycline and carbapenems, indicating their potential to disseminate within K. quasipneumoniae.

A Retrospective Study (2019-2023) on the Prevalence and Antimicrobial Resistance of Isolates from Canine Clinical Samples Submitted to the University Veterinary Hospital in Stara Zagora, Bulgaria.

The identification of local susceptibility patterns is important for the elaboration of effective local antimicrobial use guidelines and improvement in treatment outcomes. This retrospective study investigated the prevalence of microbial pathogens in dogs over a five-year period (2019-2023) and their antimicrobial resistance patterns with an emphasis on multidrug-resistant strains on the basis of 896 swab samples submitted to the microbiological laboratory at the University Veterinary Hospital, Stara Zagora, Bulgaria. A total of 1247 strains-1046 bacteria and 201 yeasts-were isolated. An increased proportion of Staphylococcus spp. as an agent of infections in dogs along with significant decrease in the share of Streptococcus spp. (from 16.2% in 2019 to 7.7% in 2023) was found. The occurrence of Staphylococcus spp. in otitis externa increased from 53.4% in 2019 to 84.5% in 2023 (p < 0.0001). The resistance of Staphylococcus spp. isolates to amoxicillin/clavulanic acid and cephalexin increased significantly in 2023 vs. 2022. At the same time, increased susceptibility to amikacin was observed in 2023 vs. 2019. For Enterobacteriaceae, significantly decreased resistance against amikacin and marbofloxacin was demonstrated in 2023 compared to 2019. Multidrug resistance (MDR) was present in 405 of 1046 bacterial isolates (38.7%). More than 50% of streptococci and pseudomonads were MDR. Of the MDR staphylococci, 41.7% were isolated from skin lesions and 28.3% were isolated from otitis. More than half of the strains resistant to seven, eight and nine groups of antimicrobial drugs (AMDs) were from wounds/abscesses. The results highlighted the importance of regular local monitoring of the spread of bacterial strains in veterinary clinics and their susceptibility to AMDs with regard to successful therapy outcomes and control on MDR spread.

Epidemiological trends in serotypes distribution and antimicrobial resistance in Salmonella from humans in Taiwan, 2004-2022

ObjectivesSalmonella, a zoonotic pathogen, significantly impacts global human health. Understanding its serotype distribution and antimicrobial resistance is crucial for effective control measures and medical interventions. MethodsWe collected Salmonella isolates and demographic data from Taiwanese hospitals between 2004 and 2022, analyzing their serotypes and antimicrobial susceptibility. ResultsAmong 40,595 isolates, salmonellosis predominated in children aged 0-4 (61.2%) years and among males (55.2%). Males also showed higher rates of extraintestinal infections (18.1% vs 16.0%, P <0.001), particularly, in the ≥65 years age group (52.4%). The top five serovars were S. Enteritidis (32.8%), S. Typhimurium (21.7%), S. Newport (6.2%), S. Stanley (4.7%), and S. Anatum (4.0%). Notably, S. Enteritidis prevalence increased from 23.9% (2004-2005) to 43.6% (2021-2022). Antimicrobial resistance was high, with a 51.6% multidrug resistance (MDR) rate. Disturbingly, MDR rates exceeded 90% in serovars Albany, Schwarzengrund, Choleraesuis, and Goldcoast. Resistance to key therapeutic agents, azithromycin, cefotaxime, and ciprofloxacin, exhibited concerning upward trends, and the surge in cefotaxime and ciprofloxacin resistance was closely linked to the emergence and spread of MDR S. Anatum and S. Goldcoast clones. ConclusionsPrioritizing control measures against S. Enteritidis and closely monitoring the prevalence and spread of MDR clones are imperative to mitigate Salmonella infections in Taiwan.

Molecular detection of Klebsiella pneumoniae producing extended-spectrum beta-lactamase isolated from bat feces from the Tanjung Ringgit bat cave, Lombok Island, Indonesia

Background and Aim: Bats are a reservoir for the pathogenic bacteria Klebsiella pneumoniae and can spread it through feces that fall in nests/caves, carried, and dropped while they fly near human settlements, and from their saliva. The emergence and spread of multidrug resistance (MDR) strains of K. pneumoniae indicate that resistant to antibiotics, especially extended-spectrum beta-lactamase (ESBL), is considered an important global health threat. The aim of this study was to determine the presence of the gene encoding extended beta-lactamase in K. pneumoniae isolated from fresh bat feces collected from the Tanjung Ringgit bat cave, East Lombok. Materials and Methods: In this study, 150 fresh fecal samples were analyzed using standard microbiological techniques for the presence of K. pneumoniae. K. pneumoniae-positive isolates were subjected to antibiotic sensitivity testing, followed by molecular detection using polymerase chain reaction. Results: This study showed that 14 (9.3%) of 150 samples were positive for K. pneumoniae. Ten of the 14 samples (71.4%) were MDR isolates and 6 (42.9%) had the blaSHV gene identified. Conclusion: The presence of K. pneumoniae isolated from fresh bat feces, which is MDR and has the blaSHV gene encoding ESBL indicates that bats can be a reservoir for the transmission of MDR and ESBL bacteria has an impact on public health in the study area. Keywords: bat, blaSHV, extended-spectrum beta-lactamase, Klebsiella pneumoniae, public health.

Multidrug-resistant Stenotrophomonas maltophilia in residential aged care facilities: An emerging threat.

Stenotrophomonas maltophilia is a multidrug-resistant (MDR), Gram-negative bacterium intrinsically resistant to beta-lactams, including last-resort carbapenems. As an opportunistic pathogen, it can cause serious healthcare-related infections. This study assesses the prevalence, resistance profiles, and genetic diversity of S. maltophilia isolated from residential aged care facilities (RACFs). RACFs are known for their overuse and often inappropriate use of antibiotics, creating a strong selective environment that favors the development of bacterial resistance. The study was conducted on 73 S. maltophilia isolates recovered from wastewater and facility swab samples obtained from three RACFs and a retirement village. Phenotypic and genotypic assessments of the isolates revealed high carbapenem resistance, exemplifying their intrinsic beta-lactam resistance. Alarmingly, 49.3% (36/73) of the isolates were non-wild type for colistin, with minimum inhibitory concentration values of > 4 mg/L, and 11.0% (8/73) were resistant to trimethoprim-sulfamethoxazole. No resistance mechanisms were detected for either antimicrobial. Genotypic assessment of known lineages revealed isolates clustering with Sm17 and Sm18, lineages not previously reported in Australia, suggesting the potential ongoing spread of MDR S. maltophilia. Lastly, although only a few isolates were biocide tolerant (2.7%, 2/73), their ability to grow in high concentrations (64 mg/L) of triclosan is concerning, as it may be selecting for their survival and continued dissemination.

Abstract 5875: Upregulation of the RNA binding protein HuR by cancer-secreted exosome to mediate multidrug resistance

Abstract Background and Aim: Multidrug resistance (MDR) is an unresolved obstacle to cancer chemotherapy. It is usually caused by overexpression of drug efflux transporters including ABCG2. Exosomes are extracellular lipid vesicles released from all cells upon the fusion of multivesicular bodies with plasma membrane. Tumor-derived exosomes have been shown to mediate cell-to-cell transfer of oncogenic materials to promote drug resistance. Human antigen R (HuR) is an extensively studied RNA binding protein that regulates the stability, translation, and nucleus-to-cytoplasm shuttling of mRNAs. Numerous HuR-targeting mRNAs play crucial roles in tumorigenesis, invasion and metastasis. We have previously reported the induction of ABCG2 and MDR phenotype by HuR overexpression in colon cancer. HuR overexpression is linked with high-grade malignancy and poor prognosis in cancer patients. This study investigated the enrichment of HuR inducing microRNAs (miRNAs) in exosomes secreted from MDR colon cancer and its intracellular transfer to drive MDR. Method: Cancer exosome-mediated transfer of miRNAs from ABCG2-overexpressing resistant colon cancer cells S1M1-80 to a few sensitive colon cell lines was evaluated. Exosomes were isolated from S1M1-80 conditioned medium by differential centrifugation method. The uptake of fluorescence-labeled exosome from donor MDR cancer cells by recipient sensitive cells was visualized by fluorescence microscopy. MiRNA microarray was conducted to identify differentially expressed miRNAs in drug sensitive cells after incubation with S1M1-80-secreted exosomes. Western blot and qPCR analysis were conducted to measure HuR and ABCG2 expression. Result: Exosomes were isolated from resistant S1M1-80 cells, whose purity was confirmed by the presence of exosomal markers (Tsg101 and Alix) but absence of cellular marker (GRP78) by Western blot analysis. These exosomes reduced the apoptotic effect of SN-38 or 5-fluorouracil in sensitive colon cancer cell lines (HCT116, S1, and SW480) by inducing both HuR and ABCG2. A common upregulated miRNA (miR-155-5p) was identified by miRNA microarray in the sensitive cell lines after incubation with S1M1-80-derived exosomes. MiR-155-5p was found to induce HuR expression by promoting its translation. MiR-155-5p inhibitor was shown to reverse the upregulation of HuR in HCT116 cells after exosome incubation, which subsequently suppressed ABCG2 expression and the MDR phenotype. Furthermore, inhibition of exosome uptake by dynasore was found to prevent the induction of HuR/ABCG2, and re-sensitize the exosome-treated sensitive cells to SN38. Conclusion: MDR cells-derived exosomes may spread the drug resistance phenotype by transferring a miR-155-5p/HuR/ABCG2 regulatory machinery to sensitive cells. Inhibition of this exosomal transfer of regulatory materials may prevent the spread of MDR and sensitize cancer cells to chemotherapy. Citation Format: Kenneth K.W. To. Upregulation of the RNA binding protein HuR by cancer-secreted exosome to mediate multidrug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5875.

Sodium sulfite-driven Helicobacter pylori eradication: Unraveling oxygen dynamics through multi-omics investigation

Due to the emergence and spread of multidrug resistance in Helicobacter pylori (H. pylori), its eradication has become difficult. Sodium sulfite (SS), a widely used food additive for ensuring food safety and storage, has been recognized as an effective nonbactericidal agent for H. pylori eradication. However, the mechanism by which H. pylori adapts and eventually succumbs under low- or no-oxygen conditions remains unknown. In this study, we aimed to evaluate the anti-H. pylori effect of SS and investigated the multiomics mechanism by which SS kills H. pylori. The results demonstrated that SS effectively eradicated H. pylori both in vitro and in vivo. H. pylori responds to the oxygen changes regulated by SS, downregulates the HcpE gene, which is responsible for redox homeostasis in bacteria, decreases the activities of enzymes related to oxidative stress, and disrupts the outer membrane structure, increasing susceptibility to oxidative stress. Furthermore, SS downregulates the content of cytochrome C in the microaerobic respiratory chain, leading to a sharp decrease in ATP synthesis. Consequently, the accumulation of triglycerides (TGs) in bacteria due to oxidative stress supports anaerobic respiration, meeting their energy requirements. The multifaceted death of H. pylori caused by SS does not result in drug resistance. Thus, screening of the redox homeostasis of HcpE as a new target for H. pylori infection treatment could lead to the development of a novel approach for H. pylori eradication therapy.

2180. Pseudomonas aeruginosa epidemic high-risk clones and their association with multidrug-resistant

Abstract Background Pseudomonas aeruginosa (PAE) is an opportunistic pathogen associated with a variety of hospital infections. Treatment of infections caused by PAE is challenging due to the emergence of multidrug-resistant (MDR), which is associated with increased morbidity, mortality, and healthcare costs. Clonal spread and the presence of resistance genes probably explain the successful propagation of MDR. In Ecuador, data on the molecular epidemiology, as well as circulating clones, are limited. Therefore, the objective of this study is to know the population structure of PAE by identifying clones in clinical samples in Quito-Ecuador. Methods A significant set (45) of randomly selected clinical PAE isolates, including multidrug and non-multidrug resistant isolates, were assigned to sequence types (STs) and compared them with their antibiotic susceptibility profile. The genetic diversity was assessed by applying the multilocus sequence typing (MLST) scheme (Figure 1) and the genetic relationships between different STs were corroborated by the phylogenetic neighbor-net network (Figure 2).Figure 1.Analysis of the allelic profiles using eBURST algorithm.Figure 2.Splits Tree showing the distribution of all the sequence types obtained for the clinical Pseudomonas aeruginosa isolates studied. The Splits Tree was based on the analysis of the allelic profiles of the acsA, aroE, guaA, mutL, nuoD, ppsA and trpE genes. Asterisk mark (*) indicates the MDR isolates Results The analysis of seven loci, acsA, aroE, guaA, mutL, nuoD, ppsA and trpE, identified 24 different ST and the most prevalent STs were ST-3750 and ST-253. A SplitsTree was constructed with all the isolates analyzed. The majority of the MDR isolates were included in ST-3750 and ST-253, also 3 singleton ST was identified in to MDR isolates. The 20 different ST was found to non-MDR isolates, and only 3 ST were found in more the one isolates. Conclusion The population structure of clinical PAE presents in these isolates indicate a significant association between MDR isolates and the clonal types: all ST-3750 and ST-253 isolates were MDR. ST-3750 is closely related strains to the ST111 (CC111), and ST-253 and ST111 are a group of successful high-risk clones and widely distributed worldwide. The multiresistant-isolates studied are grouped in the most prevalent sequence types found, and the susceptible isolates correspond mainly to singleton sequence types. Therefore, these high-risk clones and their association with multidrug resistance phenotypes are contributing to the spread of MDR in Quito-Ecuador. Disclosures Jeannete Zurita, n/a, Pfizer: Grant/Research Support

Profile and resistance levels of 136 integron resistance genes

Integrons have played a major role in the rise and spread of multidrug resistance in Gram-negative pathogens and are nowadays commonplace among clinical isolates. These platforms capture, stockpile, and modulate the expression of more than 170 antimicrobial resistance cassettes (ARCs) against most clinically-relevant antibiotics. Despite their importance, our knowledge on their profile and resistance levels is patchy, because data is scattered in the literature, often reported in different genetic backgrounds and sometimes extrapolated from sequence similarity alone. Here we have generated a collection of 136 ARCs against 8 antibiotic families and disinfectants. Cassettes are cloned in a vector designed to mimic the genetic environment of a class 1 integron, and transformed in Escherichia coli. We have measured the minimal inhibitory concentration (MIC) to the most relevant molecules from each antibiotic family. With more than 500 MIC values, we provide an exhaustive and comparable quantitation of resistance conferred by ARCs. Our data confirm known resistance trends and profiles while revealing important differences among closely related genes. We have also detected genes that do not confer the expected resistance, to the point of challenging the role of the whole family of qac genes in resistance against disinfectants. Our work provides a detailed characterization of integron resistance genes at-a-glance.

Genomic epidemiology reveals multidrug resistant plasmid spread between Vibrio cholerae lineages in Yemen

Since 2016, Yemen has been experiencing the largest cholera outbreak in modern history. Multidrug resistance (MDR) emerged among Vibrio cholerae isolates from cholera patients in 2018. Here, to characterize circulating genotypes, we analysed 260 isolates sampled in Yemen between 2018 and 2019. Eighty-four percent of V. cholerae isolates were serogroup O1 belonging to the seventh pandemic El Tor (7PET) lineage, sub-lineage T13, whereas 16% were non-toxigenic, from divergent non-7PET lineages. Treatment of severe cholera with macrolides between 2016 and 2019 coincided with the emergence and dominance of T13 subclones carrying an incompatibility type C (IncC) plasmid harbouring an MDR pseudo-compound transposon. MDR plasmid detection also in endemic non-7PET V. cholerae lineages suggested genetic exchange with 7PET epidemic strains. Stable co-occurrence of the IncC plasmid with the SXT family of integrative and conjugative element in the 7PET background has major implications for cholera control, highlighting the importance of genomic epidemiological surveillance to limit MDR spread.

Whole-genome sequencing for One Health surveillance of antimicrobial resistance in conflict zones: a case study of Salmonella spp. and Campylobacter spp. in the West Bank, Palestine.

Antimicrobial resistance (AMR) is a critical global concern driven by the overuse, misuse, and/or usage of inadequate antibiotics on humans, animals' agriculture, and as a result of contaminated environments. This study is the first One Health survey in the Middle East that incorporated whole-genome sequencing (WGS) to examine the spread of AMR in Campylobacter spp. and Salmonella spp. This cross-sectional study was conducted to examine the role of AMR at the human-animal-environmental interface and was performed in Ramallah/Al-Bireh and Jerusalem governorates of the central West Bank, Palestine. In 2021 and 2022, a total of 592 samples were collected and analyzed. From a total of 65 Campylobacter jejuni and 19 Salmonella spp. isolates, DNA was extracted for WGS using Oxford Nanopore Technologies MinION platform. We found that the dominant serotypes of C. jejuni and Salmonella enterica were present in chicken manure, chicken meat sold in markets, and feces of asymptomatic farm workers, with high genetic similarities between the isolates regardless of origin. Additionally, our results showed rapid strain turnover in C. jejuni from the same sites between 2021 and 2022. Most of the positive Salmonella spp. samples were multidrug-resistant (MDR) S. enterica serovar Muenchen carrying the plasmid of emerging S. infantis (pESI) megaplasmid, conferring resistance to multiple antibiotics. Our findings highlight the spread of MDR foodborne pathogens from animals to humans through the food chain, emphasizing the importance of a One Health approach that considers the interconnections between human, animal, and environmental health. IMPORTANCE Prior to this study, there existed hardly an integrated human-animal-environmental study of Salmonellosis and Campylobacteriosis and related AMR in Middle Eastern countries. The few existing studies lack robust epidemiological study designs, adequate for a One Health approach, and did not use WGS to determine the circulating serotypes and their AMR profiles. Civil unrest and war in Middle Eastern countries drive AMR because of the breakdown of public health and food security services. This study samples simultaneously humans, animals, and the environment to comprehensively investigate foodborne pathogens in the broiler chicken production chain in Palestine using WGS. We show that identical serotypes of C. jejuni and S. enterica can be found in samples from chicken farms, chicken meat sold in markets, and asymptomatic broiler chicken production workers. The most striking feature is the rapid dynamic of change in the genetic profile of the detected species in the same sampling locations. The majority of positive Salmonella spp. samples are MDR S. enterica serovar Muenchen isolates carrying the pESI megaplasmid. The results demonstrate a close relationship between the S. enterica serovar Muenchen isolates found in our sample collection and those responsible for 40% of all clinical Salmonella spp. isolates in Israel as previously reported, with a sequence identity of over 99.9%. These findings suggest the transboundary spread of MDR S. enterica serovar Muenchen strains from animals to humans through the food chain. The study underscores the importance of combining integrated One Health studies with WGS for detecting environmental-animal-human transmission of foodborne pathogens that could not be detected otherwise. This study showcases the benefits of integrated environmental-animal-human sampling and WGS for monitoring AMR. Environmental samples, which may be more accessible in conflict-torn places where monitoring systems are limited and regulations are weak, can provide an effective AMR surveillance solution. WGS of bacterial isolates provides causal inference of the distribution and spread of bacterial serotypes and AMR in complex social-ecological systems. Consequently, our results point toward the expected benefits of operationalizing a One Health approach through closer cooperation of public and animal health and food safety authorities.

Spread of multidrug resistance in non-PCV13/PCV20 serotypes of Streptococcus pneumoniae: A cross-sectional study ten years after the introduction of pneumococcal conjugate vaccine in Japan

Ten years after the introduction of the pneumococcal conjugate vaccine (PCV) in Japan, the prevalence rates of non-PCV13 and non-PCV20 serotypes among pediatric pneumococcal isolates were 94.0% and 73.7%, respectively. The predominant non-PCV13/PCV20 serotypes (15A, 35B, and 23A) were mostly multidrug-resistant (≥80.5%), exhibiting non-susceptibility to penicillin.

Analysis of Regulatory Mechanism of AcrB and CpxR on Colistin Susceptibility Based on Transcriptome and Metabolome of Salmonella Typhimurium.

With the increasing and inappropriate use of colistin, the emerging colistin-resistant isolates have been frequently reported during the last few decades. Therefore, new potential targets and adjuvants to reverse colistin resistance are urgently needed. Our previous study has confirmed a marked increase of colistin susceptibility (16-fold compared to the wild-type Salmonella strain) of cpxR overexpression strain JSΔacrBΔcpxR::kan/pcpxR (simplified as JSΔΔ/pR). To searching for potential new drug targets, the transcriptome and metabolome analysis were carried out in this study. We found that the more susceptible strain JSΔΔ/pR displayed striking perturbations at both the transcriptomics and metabolomics levels. The virulence-related genes and colistin resistance-related genes (CRRGs) were significantly downregulated in JSΔΔ/pR. There were significant accumulation of citrate, α-ketoglutaric acid, and agmatine sulfate in JSΔΔ/pR, and exogenous supplement of them could synergistically enhance the bactericidal effect of colistin, indicating that these metabolites may serve as potential adjuvants for colistin therapy. Additionally, we also demonstrated that AcrB and CpxR could target the ATP and reactive oxygen species (ROS) generation, but not proton motive force (PMF) production pathway to potentiate antibacterial activity of colistin. Collectively, these findings have revealed several previously unknown mechanisms contributing to increased colistin susceptibility and identified potential targets and adjuvants for potentiating colistin treatment of Salmonella infections. IMPORTANCE Emergence of multidrug-resistant (MDR) Gram-negative (G-) bacteria have led to the reconsideration of colistin as the last-resort therapeutic option for health care-associated infections. Finding new drug targets and strategies against the spread of MDR G- bacteria are global challenges for the life sciences community and public health. In this paper, we demonstrated the more susceptibility strain JSΔΔ/pR displayed striking perturbations at both the transcriptomics and metabolomics levels and revealed several previously unknown regulatory mechanisms of AcrB and CpxR on the colistin susceptibility. Importantly, we found that exogenous supplement of citrate, α-ketoglutaric acid, and agmatine sulfate could synergistically enhance the bactericidal effect of colistin, indicating that these metabolites may serve as potential adjuvants for colistin therapy. These results provide a theoretical basis for finding potential new drug targets and adjuvants.

Spread of multidrug-resistant Pseudomonas aeruginosa in animal-derived foods in Beijing, China

Pseudomonas aeruginosa is the most common bacterium occurred in nosocomial infections and is also an important indicator of food spoilage. The worldwide spread of multidrug resistant (MDR) P. aeruginosa is threatening public health. However, the prevalence and spread of MDR P. aeruginosa through the food chain is little referred under the One Health perspective. Here, we collected a total of 259 animal-derived foods (168 chicken and 91 pork) from 16 supermarkets and farmer's markets in six regions of Beijing, China. The prevalence of P. aeruginosa in chicken and pork was 42.1 %. The phenotypic antimicrobial susceptibility testing showed that 69.7 % of isolates were MDR, and isolates from Chaoyang district exhibited a higher resistance rate compared to that from Xicheng district (p < 0.05). P. aeruginosa isolates exhibited high levels of resistance against β-lactams (91.7 %), cephalosporins (29.4 %), and carbapenems (22.9 %). Interestingly, none of strains showed resistance to amikacin. Whole-genome sequencing showed that all isolates carried various kinds of antimicrobial resistance genes (ARGs) and virulence genes (VGs), especially for blaOXA genes and phz genes. Multilocus sequence typing (MLST) analysis indicated that ST111 (12.8 %) was the most predominant ST. Notably, the emergence of ST697 clones in food-borne P. aeruginosa was firstly reported. In addition, the toxin pyocyanin was detected in 79.8 % of P. aeruginosa strains. These findings help to decipher the prevalence and the strong toxigenic ability of MDR P. aeruginosa from animal-derived foods and highlight the effective supervision of animal-derived food hygiene should be strengthened to prevent the spread of ARGs in a One Health strategy.

Mitigation of antimicrobial resistance genes in greywater treated at household level

Greywater often contains microorganisms carrying antimicrobial resistance genes (ARGs). Reuse of greywater thus potentially facilitates the enrichment and spread of multidrug resistance, posing a possible hazard for communities that use it. As water reuse becomes increasingly necessary, it is imperative to determine how greywater treatment impacts ARGs. In this study, we characterize ARG patterns in greywater microbial communities before and after treatment by a recirculating vertical flow constructed wetland (RVFCW). This greywater recycling method has been adopted by some small communities and households for greywater treatment; however, its ability to remove ARGs is unknown. We examined the taxonomic and ARG compositions of microbial communities in raw and treated greywater from five households using shotgun metagenomic sequencing. Total ARGs decreased in abundance and diversity in greywater treated by the RVFCW. In parallel, the microbial communities decreased in similarity in treated greywater. Potentially pathogenic bacteria associated with antimicrobial resistance and mobile genetic elements were detected in both raw and treated water, with a decreasing trend after treatment. This study indicates that RVFCW systems have the potential to mitigate antimicrobial resistance-related hazards when reusing treated greywater, but further measures need to be taken regarding persistent mobile ARGs and potential pathogens.

High-Efficiency Photodynamic Control of Antibiotic-Resistant Bacteria and Antibiotic-Resistant Genes in Wastewater Using Hydrogel-Decorated Porous Polyurethane Sponges with Metal Nanoparticles

The overuse and misuse of antibiotics in hospitals and other healthcare settings can lead to the development and spread of multidrug resistance (MDR) bacteria and water contaminants. In this study, silver nanoparticles (AgNPs)-loaded chitosan (CS)-alginate (AA) hydrogels were prepared to control wastewater MDR bacterial contaminants. CS-AA/AgNP composites strongly inhibited a wastewater MDR Enterobacter tabaci biofilm on membrane surfaces. The effect of AgNP-loaded CS-AA composite hydrogels on the gelation time, swelling ratio, in vitro degradation, and in vitro release properties was investigated. Furthermore, due to their outstanding environmentally friendly superhydrophobicity/superoleophilicity, sponges have proven compelling advantages in the area of water contaminants. Therefore, CS-AA/AgNP composites were coated on polyurethane sponges (PUSs) for disinfection applications in wastewater. CS-AA/AgNP composites and CS-AA/AgNP-coated (5 wt %) PUS exhibited higher photodynamic inactivation (PDI) of E. tabaci under blue LED light. In particular, modified PUS exhibited almost complete inactivation (5.1 log cfu/mL) at 40 min. Furthermore, tetracycline antibiotic degradation efficiency was observed to be 72.91% when the modified PUSs were added to antibiotic-polluted water in the designed reactor. In correlation with the degradation of resistance bacteria and antibiotics, the modified PUS in the designed reactor with PDI effect completely degraded tetracycline antibiotic resistance genes (ARGs) tetA and tetB at 45 min and 60 min, respectively. Specifically, PDI action on the modified PUS effectively degraded ARGs such as sul1, tetA, and tetB by 4.2, 3.2, and 2.9 log reduction (copies/mL), respectively. Excellent removal of ARGs after blue LED treatment indicated that the release of MDR pathogens and free ARGs was effectively controlled by the modified PUS photodynamic reaction. Therefore, the modified PUS can be considered as an alternative approach to remove MDR bacteria and free ARGs in the large-scale photodynamic disinfection process.