Prevalence Of Antibiotic Resistance Genes Research Articles

Spread of antibiotic resistance genes to Antarctica by migratory birds

Recent studies have highlighted the presence of antibiotic resistance genes (ARGs) in Antarctica, which are typically indicative of human activity. However, these studies have concentrated in the Antarctic Peninsula region, and relatively less is known about ARG prevalence in East Antarctica, where human activity levels are lower compared to the Antarctic Peninsula. In addition, the mechanisms of ARG transmission to Antarctica through natural or anthropogenic pathways remain unclear. In this study, we analyzed the fecal samples of Adélie penguins and South polar skuas by using high-throughput sequencing and microfluidic quantitative PCR to detect potential pathogens and ARGs at their breeding colonies near Syowa Station in East Antarctica. These results revealed the presence of several potential pathogens in the fecal matter of both bird species. However, the HF183 marker, which indicates human fecal contamination, was absent in all samples, as well as seawater sampled near the breeding colonies. This suggests that the human fecal contamination was negligible in our study area. In addition to pathogens, we found a significant number of ARGs and metal resistance genes in the feces of both Adélie penguins and South polar skuas, with higher detection rates in skuas than in penguins. To better understand how these birds acquire and transmit these genes, we analyzed the migratory patterns of Adélie penguins and South polar skuas by geolocator tracking. We found that the skuas migrate to the tropical and subtropical regions of the Indian Ocean during the austral winter. On the other hand, Adélie penguins exhibited a more localized migration pattern, mainly staying within Antarctic waters. Because the Indian Ocean is considered one of the major reservoirs of ARGs, South polar skuas might be exposed to ARGs during their winter migration and transfer these genes to Antarctica.

Antimicrobial peptides: An alternative to antibiotic for mitigating the risks of Antibiotic resistance in aquaculture

The utilization of antibiotics increases the prevalence of antibiotic resistance genes (ARGs) in various matrices and poses the potential risk of ARG transmission, garnering global attention. Antimicrobial peptides (AMPs) represent a promising novel category of antimicrobials that may address the urgent issue of antibiotic resistance. Here, a zebrafish cultivation assay in which zebrafish were fed a diet supplemented with AMP (Cecropin A) or antibiotics was conducted to determine the effects of the intervention on the microorganisms and antibiotic resistance spectrum in zebrafish gut samples. Cecropin A treatment decreased the α-diversity of the microbiota. Moreover, NMDS (nonmetric multidimensional scaling) results revealed that the β-diversity in the microbiota was more similar between the control (CK) and Cecropin A samples than between the antibiotic treatment groups. The absolute quantity of ARGs in the AMP treatment was less than that observed in the antibiotic treatment. The findings indicated that FFCH7168, Chitinibacter and Cetobacterium were the most significant biomarkers detected in the CK, Cecropin A and antibiotic treatments, respectively. Although the use of antibiotics notably enhanced the occurrence of multidrug-resistant bacteria, the application of Cecropin A did not lead to this phenomenon. The results indicated that the application of AMPs can effectively manage and control ARGs in aquaculture.

16S rDNA-Based Amplicon Analysis Unveiled a Correlation Between the Bacterial Diversity and Antibiotic Resistance Genes of Bacteriome of Commercial Smokeless Tobacco Products.

The distribution of bacterial-derived antibiotic resistance genes (ARGs) in smokeless tobacco products is less explored and encourages understanding of the ARG profile of Indian smokeless tobacco products. Therefore, in the present investigation, ten commercial smokeless tobacco products were assessed for their bacterial diversity to understand the correlation between the inhabitant bacteria and predicted ARGs using a 16S rDNA-based metagenome analysis. Overall analysis showed the dominance of two phyla, i.e., Firmicutes (43.07%) and Proteobacteria (8.13%) among the samples, where Bacillus (9.76%), Terribacillus (8.06%), Lysinibacillus (5.8%), Alkalibacterium (5.6%), Oceanobacillus (3.52%), and Dickeya (3.1%) like genera were prevalent among these phyla. The phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt)-based analysis revealed 217 ARGs which were categorized into nine groups. Cationic antimicrobial polypeptides (CAMP, 33.8%), vancomycin (23.4%), penicillin-binding protein (13.8%), multidrug resistance MDR (10%), and β-lactam (9.3%) were among the top five contributors to ARGs. Staphylococcus, Dickeya, Bacillus, Aerococcus, and Alkalibacterium showed their strong and significant correlation (p value < 0.05) with various antibiotic resistance mechanisms. ARGs of different classes (blaTEM, blaSHV, blaCTX, tetX, vanA, aac3-II, mcr-1, intI-1, and intI2) were also successfully amplified in the metagenomes of SMT samples using their specific primers. The prevalence of ARGs in inhabitant bacteria of smokeless tobacco products suggests making steady policies to regulate the hygiene of commercial smokeless tobacco products.

Gamma-ray irradiation as an effective method for mitigating antibiotic resistant bacteria and antibiotic resistance genes in aquatic environments

The prevalence of antibiotic resistance genes (ARGs) in municipal wastewater treatment plants (MWTPs) has emerged as a significant environmental concern. Despite advanced treatment processes, high levels of ARGs persist in the secondary effluent from MWTPs, posing ongoing environmental risks. This study explores the potential of gamma-ray irradiation as a novel approach for sterilizing antibiotic-resistant bacteria (ARB) and reducing ARGs in MWTP secondary effluent. Our findings reveal that gamma-ray irradiation at an absorbed dose of 1.6 kGy effectively deactivates all culturable bacteria, with no subsequent revival observed after exposure to 6.4 kGy and a 96-h incubation in darkness at room temperature. The removal efficiencies for a range of ARGs, including tetO, tetA, blaTEM-1, sulI, sulII, and tetW, were up to 90.5% with a 25.6 kGy absorbed dose. No resurgence of ARGs was detected after irradiation. Additionally, this study demonstrates a considerable reduction in the abundances of extracellular ARGs, with the transformation efficiencies of extracellular tetracycline and sulfadiazine resistance genes decreasing by 56.3–81.8% after 25.6 kGy irradiation. These results highlight the effectiveness of gamma-ray irradiation as an advanced and promising method for ARB sterilization and ARG reduction in the secondary effluent of MWTPs, offering a potential pathway to mitigate environmental risks associated with antibiotic resistance.

Butyric Acid Supplementation Reduces Changes in the Taxonomic and Functional Composition of Gut Microbiota Caused by H. pylori Eradication Therapy.

Twenty two H. pylori-positive patients, aged 19 to 64 years, were enrolled in the study and randomized into two treatment groups, as follows: (1) ECAB-14 (n = 11), with esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, per os, for 14 days, and (2), ECAB-Z-14 (n = 11), with esomeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, and bismuthate tripotassium dicitrate 240 mg, twice daily, along with butyric acid+inulin (Zacofalk), two tablets daily, each containing 250 mg of butyric acid, and 250 mg of inulin, per os, for 14 days. Fecal samples were collected from each subject prior to eradication therapy (time point I), after the end of eradication therapy (time point II), and a month after the end of eradication therapy (time point III). The total DNA from the fecal samples was isolated for whole genome sequencing using the Illumina NextSeq 500 platform. Qualitative and quantitative changes in gut microbiota were assessed, including alpha and beta diversity, functional potential and antibiotic resistance gene profiling. Gut microbiota alpha diversity significantly decreased compared with the baseline immediately after eradication therapy in both treatment groups (ECAB-14 and ECAB-Z-14). This diversity reached its baseline in the ECAB-Z-14 treatment group a month after the end of eradication therapy. However, in the ECAB-14 treatment arm, a reduction in the Shannon index was observed up to a month after the end of H. pylori eradication therapy. Fewer alterations in the gut microbiota functional potential were observed in the ECAB-Z-14 treatment group. The abundance of genes responsible for the metabolic pathway associated with butyrate production decreased only in the ECAB-14 treatment group. The prevalence of antibiotic-resistant genes in the gut microbiota increased significantly in both treatment groups by the end of treatment. However, more severe alterations were noted in the ECAB-14 treatment group. H. pylori eradication therapy leads to taxonomic changes, a reduction in the alpha diversity index, and alterations in the functional potential of the gut microbiota and gut resistome. Taking butyric acid+inulin supplements during H. pylori eradication therapy could help maintain the gut microbiota in its initial state and facilitate its recovery after H. pylori eradication.

The impact of polymorphic variants of interferon receptor genes on COVID-19 severity and antibiotic resistance

Single nucleotide substitutions in gene sequence associated with conformational changes in protein receptor or in expression of interferon receptors may explain variations in human susceptibility to infection and severity of COVID-19 along with other well-known risk factors. The study aimed to investigate associations between polymorphic variants of interferon receptor genes, COVID-19 severity and prevalence of antibiotic resistance genes in the gut microbiota. Materials and methods. The study was conducted using a random sample of Arkhangelsk population aged 42 to 76 years (n = 305). The research involved gathering COVID-19 data from the Federal Register, conducting blood tests for SARS-CoV-2 antibodies and polymorphic interferon receptor gene variants, and identifying antibiotic resistance genes in stool samples. Results. During the first 12–15 months of the COVID-19 pandemic, 17.4% of the study participants had symptomatic COVID-19, while 32.8% were asymptomatic. By the Autumn of 2022, symptomatic COVID-19 cases rose up to 36.4%, while asymptomatic cases increased to 61.3%. We reveal an association between the CC genotype of the IFNAR1 gene rs2257167 variant, the presence of the T allele of IFNAR2 gene rs2229207 variant, the CCTT haplotype and symptomatic COVID-19. The GCTC haplotype was associated with pneumonia and COVID-19 severity. In November 2022, macrolide resistance genes were observed in 98.4% of cases, whereas those to beta-lactams and glycopeptides — in 26.9% and 13.8% cases, respectively. Resistance to three classes of antibiotics was observed in 4.9% and was more frequently detected in individuals with the ССТТ haplotype. Genes encoding beta-lactamases were more often found in individuals with the GCTC haplotype, those who had COVID-19 with pneumonia and those who received hospital treatment. Glycopeptide resistance genes were associated with the CC genotype of the rs2257167 variant of IFNAR1 gene. Conclusion. We identified genetic determinants of susceptibility, symptomatic infection and COVID-19 severity. The associations between polymorphic variants of interferon receptor genes and COVID-19 severity can be used to identify people with a genetic predisposition to severe infection and to determine priority groups for vaccination, including the prevention of antibiotic resistance in complicated course of viral infections.

A comprehensive analysis of antibiotic resistance genes in the giant panda gut.

In this study, we have successfully constructed a comprehensive database of metagenome-assembled genomes (MAGs) pertaining to the gut microbiota of the giant panda. Through our analysis, we have identified significant reservoirs of antibiotic resistance genes (ARGs), namely Escherichia coli, Citrobacter portucalensis, and Klebsiella pneumoniae. Furthermore, we have elucidated the primary contributors to ARGs, including Streptococcus alactolyticus and Clostridium SGBP116, in both captive and wild pandas. Additionally, our findings have demonstrated a higher prevalence of ARGs in the metagenome, with notable expression of the RPOB2 gene in S. alactolyticus. Crucially, 1217 ARGs shared homology with human gut ARGs, underscoring the interaction relationship between pandas and human microbiomes. These findings are instrumental in understanding the antibiotic resistance landscape in the giant panda's gut, providing a framework for developing strategies to combat antibiotic resistance and safeguard the health of this endangered species.

The prevalence of antibiotic resistance genes of carbopenemases of the metallo-β-lactamase group in enterobacteria strains isolated from patients of a multidisciplinary hospital in a region with a developed petrochemical industry

The research work included strains of Klebsiella pneumonaie (n = 128) isolated from patients of a multidisciplinary hospital in a large industrial city. The antibiotic sensitivity of the isolated pure cultures was studied in relation to the most popular antibacterial drugs in clinical practice (in the amount of 21), by the standard disco-diffusion method. Identification of resistance genes was carried out by PCR using commercial reagent kits «AmpliSens MDR-MBL-FL», «AmpliSens MDR-KPC/OXA-48‑FL». The results of determining the sensitivity of isolates isolated from the lower respiratory tract revealed low activity of amoxicillin/clavulanic acid, cephalosparins of the III and IV generation (ceftazidim, cefotaxime, cefepim). 86.7 % of isolates are resistant to the aminoglycoside group — amikacin, and 100 % are resistant to gentamicin. Meropenem was the most active of the carbapenem group — 26.6 %, about 7 % are sensitive to ertapenem. From the group of fluoroquinolones, the sensitivity varied from 20 to 30 %. The greatest activity of all drugs was shown by ticarcillin / clavulanate — 33.3 %. A high proportion of strains of Kl. pneumoniae with a phenotype of multiple resistance has been established. The identification of resistance genes made it possible to establish their diversity in antibiotic-resistant isolates, a high proportion (26.6 %) of multi-resistant strains with the absence of the studied genes, and the combination of VIM + NDM + OXA-48 genes, identified in every second studied strain, prevails. Thus, the analysis of the prevalence of antibiotic resistance genes of carbopenemases of the metallo- β-lactamase group in enterobacteria strains isolated from patients of a multidisciplinary hospital in a region with a developed petrochemical industry showed the predominance of isolates (53.9 %) with the production of a combination of three antibiotic resistance genes (VIM + NDM + OXA-48). Isolates containing two genes simultaneously (NDM + OXA-48 and VIM + OXA-48) identified in 7.8 and 6.3 %. Isolates containing a single gene (carbapenemase Kl. Pneumoniae) amounted to 5.4 %.

Epidemiological investigation and β-lactam antibiotic resistance of Riemerella anatipestifer isolates with waterfowl origination in Anhui Province, China

Riemerella anatipestifer (R. anatipestifer) is a highly pathogenic and complex serotypes waterfowl pathogen with inherent resistance to multiple antibiotics. This study was aimed to investigate the antibiotic resistance characteristics and genomic features of R. anatipestifer isolates in Anhui Province, China in 2023. A total of 287 cases were analysed from duck farms and goose farms, and the R. anatipestifer isolates were subjected to drug resistance tests for 30 antimicrobials. Whole genome sequencing (WGS) and bioinformatics analysis were performed on the bacterial genomes, targeting the β-lactam resistance genes. The results showed that a total of 74 isolates of R. anatipestifer were isolated from 287 cases, with a prevalence of 25.8%. The antimicrobial susceptibility testing (AST) revealed that all the 74 isolates were resistant to multiple drugs, ranging from 13 to 26 kinds of drugs. Notably, these isolates showed significant resistance to aminoglycosides and macrolides, which are also commonly used in clinical practices. Data revealed the presence of several β-lactamase-related genes among the isolates, including a novel blaRASA-1 variant (16.2%), the class A extended-spectrum β-lactamase blaRAA-1 (12.2%), and a blaOXA-209 variant (98.6%). Functional analysis of the variants blaRASA-1 and blaOXA-209 showed that the blaRASA-1 variant exhibited activity against various β-lactam antibiotics while their occurrence in R. anatipestifer were not common. The blaOXA-209 variant, on the other hand, did not perform any β-lactam antibiotic resistance. Furthermore, we observed that blaRAA-1 could undergo horizontal transmission among different bacteria via the insertion sequence IS982. In conclusion, this study delves into the high prevalence of R. anatipestifer infection in waterfowl in Anhui, China. The isolated strains exhibit severe drug resistance issues, closely associated with the prevalence of antibiotic resistance genes (ARG). Additionally, our research investigates the β-lactam antibiotic resistance mechanism in R. anatipestifer.

Winged resistance: Storks and gulls increase carriage of antibiotic resistance by shifting from paddy fields to landfills

Waterbirds are vectors for the dissemination of antimicrobial resistance across environments, with some species increasingly reliant on highly anthropized habitats for feeding. However, data on the impact of their feeding habits on the carriage of antibiotic resistance genes (ARGs) are still scarce. To fill this gap, we examined the microbiota (16S rRNA amplicon gene sequencing) and the prevalence of ARG (high-throughput qPCR of 47 genes) in faeces from white storks (Ciconia ciconia) and lesser black-backed gulls (Larus fuscus) feeding in highly (landfill) and less (paddy fields) polluted habitats. Faecal bacterial richness and diversity were higher in gulls feeding upon landfills and showed a greater abundance of potential pathogens, such as Staphylococcus. In contrast, faecal bacterial communities from storks were similar regardless of habitat preferences, maybe due to a less intense habitat use compared to gulls. In addition, birds feeding in the landfill carried a higher burden of ARGs compared to the surrounding soil and surface waters. Network analysis revealed strong correlations between ARGs and potential pathogens, particularly between tetM (resistance to tetracyclines), blaCMY (beta-lactam resistance), sul1 (sulfonamide resistance) and members of the genera Streptococcus, Peptostreptococcus, and Peptoclostridium. Our work demonstrates how transitioning from paddy fields to landfills fosters the carriage of ARGs and potential pathogens in the bird gut, shedding light on the ecological role of these avian vectors in antimicrobial resistance dissemination.

ANALYSIS OF ANTIBIOTIC RESISTANCE GENES OF ESCHERICHIA COLI FROM THE GUT OF THE PIGLETS WITH DIARRHEA

The study is devoted to the analysis of the prevalence of antibiotic resistance genes in cultures of E. coli isolated from the gut of the piglets with diarrhea. With the use of high-throughput sequencing, it was possible to identify 26 antibiotic resistance genes. They belonged to 7 groups of antibiotics: aminoglycosides, beta-lactam antibiotics, quinolones, sulfonamides, tetracyclines, diaminopyrimidine, phenicols. The relative abundance of the QnrD gene was maximal in the studied sample of E. coli isolates (50%). For other sequences of antibiotic resistance genes, the percentage ratio of each separate group of genes did not exceed 10%. The largest number of gene variants was characteristic of the class of genes resistant to beta-lactam antibiotics (AmpC1_Ecoli, OXA-10, OXA-14, OXA-16, Penicillin_Binding_Protein_Ecoli, TEM-143, TEM-166, TEM-215 and TEM-76, TEM- 95).

Antibiotic Resistance and Virulence Factors in Clinical Isolates of Stenotrophomonas maltophilia from Hospitalized Patients in Tehran, Iran.

Stenotrophomonas maltophilia causes challenging infections in immunocompromised patients, exhibiting increasing resistance to multiple antimicrobials and possessing various virulence genes, including emerging resistance to trimethoprim-sulfamethoxazole. A total of 80 clinical isolates of S. maltophilia were collected from multiple hospitals in Tehran, Iran. This study conducted an analysis of antibiotic susceptibility by disc diffusion method and E-test assay, resistance and virulence gene frequencies were examined by PCR-sequencing, and multilocus sequencing typing (MLST) was performed for strain typing. Across the tested isolates, we observed notably high resistance rates for imipenem 80 (100%), meropenem 78(97.5%), and ceftazidime 72 (90%), while trimethoprim-sulfamethoxazole (SXT) showed a lower resistance rate of 2 (2.5%). Minocycline and levofloxacin demonstrated the highest susceptibility rates, with 70 (87.5%) and 80 (100%), respectively. The prevalence of antibiotic resistance genes bla L1, and bla L2 was 71 (88.75%) and 76 (95%), respectively. Additionally, the PCR analysis revealed that the frequency of virulence genes (fliC, virB, papD, pilU, hlyIII, stmPr1, and stmPr2) was 78 (97.5%), 77 (96.25%), 58 (72.5%), 77 (96.2%), 76 (95%), 31 (38.75%), and 80 (100%), respectively. Resistance to SXT isolate belong to the sequence type (ST15) and exhibits allelic profiles of (10, 29, 21, 21, 32, 32, and 10). The data obtained from our investigation have indicated that SXT remains an efficacious antibiotic and also highlighted the importance of effective management, identification of resistant isolates, and typing methods to address the global prevalence of antibiotic resistance in S. maltophilia.

Dynamics of antibiotic resistance genes and the association with bacterial community during pig manure composting with chitin and glucosamine addition.

In modern ecological systems, the overuse and misuse of antibiotics have escalated the prevalence of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), positioning them as emerging environmental contaminants. Notably, composting serves as a sustainable method to recycle agricultural waste into nutrient-rich fertilizer while potentially reducing ARGs and MGEs. This study conducted a 47-day composting experiment using pig manure and corn straw, supplemented with chitin and N-Acetyl-D-glucosamine, to explore the impact of these additives on the dynamics of ARGs and MGEs, and to unravel the interplay between these genetic elements and microbial communities in pig manure composting. Results showed that adding 5% chitin into composting significantly postponed thermophilic phase, yet enhanced the removal efficiency of total ARGs and MGEs by over 20% compared to the control. Additionally, the addition of N-Acetyl-D-glucosamine significantly increased the abundance of tetracycline-resistant and sulfonamide-resistant genes, as well as MGEs. High-throughput sequencing revealed that N-Acetyl-D-glucosamine enhanced bacterial α-diversity, providing diverse hosts for ARGs and MGEs. Resistance mechanisms, predominantly efflux pumps and antibiotic deactivation, played a pivotal role in shaping the resistome of composting process. Co-occurrence network analysis identified the key bacterial phyla Proteobacteria, Firmicutes, Gemmatimonadota, and Myxococcota in ARGs and MGEs transformation and dissemination. Redundancy analysis indicated that physicochemical factors, particularly the carbon-to-nitrogen ratio emerged as critical variables influencing ARGs and MGEs. The findings lay a foundation for the developing microbial regulation method to reduce the risks of ARGs in animal manure composts.

Reference gene catalog and metagenome-assembled genomes from the gut microbiome reveal the microbial composition, antibiotic resistome, and adaptability of a lignocellulose diet in the giant panda

The giant panda, a strict herbivore that feeds on bamboo, still retains a typical carnivorous digestive system. Reference catalogs of microbial genes and genomes are lacking, largely limiting the antibiotic resistome and functional exploration of the giant panda gut microbiome. Here, we integrated 177 fecal metagenomes of captive and wild giant pandas to construct a giant panda integrated gene catalog (GPIGC) comprised of approximately 4.5 million non-redundant genes and reconstruct 393 metagenome-assembled genomes (MAGs). Taxonomic and functional characterization of genes revealed that the captivity of the giant panda significantly changed the core microbial composition and the distribution of microbial genes. Higher abundance and prevalence of antibiotic resistance genes (ARGs) were detected in the guts of captive giant pandas, and ARG distribution was influenced by geography, for both captive and wild individuals. Escherichia, as the prevalent genus in the guts of captive giant pandas, was the main carrier of ARGs, meaning there is a high risk of ARG transmission by Escherichia. We also found that multiple mcr gene variants, conferring plasmid-mediated mobile colistin resistance, were widespread in the guts of captive and wild giant pandas. There were low proportions of carbohydrate-active enzyme (CAZyme) genes in GPIGC and MAGs compared with several omnivorous and herbivorous mammals. Many members of Clostridium MAGs were significantly enriched in the guts of adult, old and wild giant pandas. The genomes of isolates and MAGs of Clostridiaceae harbored key genes or enzymes in complete pathways for degrading lignocellulose and producing short-chain fatty acids (SCFAs), indicating the potential of these bacteria to utilize the low-nutrient bamboo diet. Overall, our data presented an exhaustive reference gene catalog and MAGs in giant panda gut and provided a comprehensive understanding of the antibiotic resistome and microbial adaptability for a high-lignocellulose diet.

Tire particles and its leachates: Impact on antibiotic resistance genes in coastal sediments

Tire particles (TPs), a significant group of microplastics, can be discharged into the coastal environments in various ways. However, our understanding of how TPs impact the antibiotic resistance and pathogenic risks of microorganisms in coastal sediments remains limited. In this study, we used metagenomics to investigate how TPs and their leachates could affect the prevalence of antibiotic resistance genes (ARGs), virulence factor genes (VFGs), and their potential risks to the living creatures such as soil invertebrates and microorganisms in the coastal sediments. We discovered that TP addition significantly increased the abundance and diversity of ARGs and VFGs in coastal sediments, with raw TPs displayed higher impacts than TP leachates and TPs after leaching on ARGs and VFGs. With increasing TP exposure concentrations, the co-occurrence frequency of ARGs and mobile genetic elements (MGEs) in the same contig also increased, suggesting that TPs could enhance the dispersal risk of ARGs. Our metagenome-based binning analysis further revealed that exposure to TPs increased the abundance of potentially pathogenic antibiotic-resistant bacteria (PARB). In addition, chemical additives of TP leachates (e.g., Zn and N-cyclohexylformamide) significantly affected the changes of ARGs in the pore water. In summary, our study provides novel insights into the adverse effects of TP pollutions on aggravating the dissemination and pathogenic risks of ARGs and PARB in the coastal environment.

Bacterial community structure, adaptations and prevalence of antimicrobial resistance in bacteria from Antarctica: A review

Antarctica serves as an ideal prototype to study past climatic condition as the ice core records dates back to 100,000 years. Microbiological research on ice core has opened a doorway to our understanding on biodiversity and its contribution to the frozen ecosystem. In this review, the ice core bacterial diversity of East and West Antarctica has been documented. Cold-adapted bacteria hold immense potential in biotechnological applications as they possess functional advantages over mesophilic bacteria. Some of the neoteric applications of bioproducts of Antarctic bacteria have been stated in this review. The current climate change due to global warming exerts a humongous effect on the ecosystem of the polar region. The region being susceptible to any fluctuation in temperature, the exacerbated melting of Antarctic glaciated mass contributes to the rise of global sea level, with loss of ice harbouring unknown microbial entities. This review mainly focuses on the bacterial diversity of East and West Antarctic counterparts, the prevalence of antibiotic-resistant genes, the adaption strategies conferred by bacteria thriving in Antarctic habitats and their potential biotechnological applications.

Shotgun Metagenomics-Guided Prediction Reveals the Metal Tolerance and Antibiotic Resistance of Microbes in Poly-Extreme Environments in the Danakil Depression, Afar Region.

The occurrence and spread of antibiotic resistance genes (ARGs) in environmental microorganisms, particularly in poly-extremophilic bacteria, remain underexplored and have received limited attention. This study aims to investigate the prevalence of ARGs and metal resistance genes (MRGs) in shotgun metagenome sequences obtained from water and salt crust samples collected from Lake Afdera and the Assale salt plain in the Danakil Depression, northern Ethiopia. Potential ARGs were characterized by the comprehensive antibiotic research database (CARD), while MRGs were identified by using BacMetScan V.1.0. A total of 81 ARGs and 39 MRGs were identified at the sampling sites. We found a copA resistance gene for copper and the β-lactam encoding resistance genes were the most abundant the MRG and ARG in the study area. The abundance of MRGs is positively correlated with mercury (Hg) concentration, highlighting the importance of Hg in the selection of MRGs. Significant correlations also exist between heavy metals, Zn and Cd, and ARGs, which suggests that MRGs and ARGs can be co-selected in the environment contaminated by heavy metals. A network analysis revealed that MRGs formed a complex network with ARGs, primarily associated with β-lactams, aminoglycosides, and tetracyclines. This suggests potential co-selection mechanisms, posing concerns for both public health and ecological balance.

Mobile genetic elements affect the dissemination of antibiotic resistance genes (ARGs) of clinical importance in the environment

The prevalence of antibiotic resistance genes (ARGs) in the environment is a quintessential One Health issue that threats both human and ecosystem health; however, the source and transmission of ARGs, especially clinically important ARGs (CLIARGs), in the environment have not yet been well studied. In the present study, shotgun metagenomic approaches were used to characterize the microbiome, resistome, and mobilome composition in human feces and six different environment sample types in South China. Overall, the resistome harbored 157 CLIARGs, with specific ARG hotspots (e.g., human feces, wastewater treatment plants, livestock manure and wastewater) excreting significantly higher abundance of CLIARGs compared with the natural environment. A redundancy analysis (RDA) was performed and revealed that the bacterial community compositions and mobile genetic elements (MGEs) explained 55.08% and 34.68% of the variations in ARG abundance, respectively, indicating that both bacterial community and MGEs are key contributors to the maintenance and dissemination of CLIARGs in the environment. The network analysis revealed non-random co-occurrence patterns between 200 bacterial genera and 147 CLIARGs, as well as between 135 MGEs and 123 CLIARGs. In addition to numerous co-shared CLIARGs among different sample types, the source tracking program based on the FEAST probabilistic model was used to estimate the relative contributions of the CLIARGs from potential sources to the natural environment. The source tracking analysis results delineated that mobilome, more than microbiome, contributed CLIARG transmission from those ARG hotspots into natural environment, and the MGEs in WWTPs seem to play the most significant role in the spread of CLIARGs to the natural environment (average contribution 32.9%–46.4%). Overall, this study demonstrated the distribution and dissemination of CLIARGs in the environment, and aimed to better inform strategies to control the spread of CLIARGs into the natural environment.

2459. Prevalence of Nasopharyngeal Carriage of Macrolide and Lincosamide Resistance Genes Among a Household-based cohort of Children and Adults in a Peri-urban Community in Peru

Abstract Background Antibiotic resistant infections commonly occur in healthcare settings, but the prevalence of antibiotic resistant genes (ARGs) in healthy individuals in the community is unknown. We provide an initial assessment of nasopharyngeal carriage of ARGs conferring resistance to macrolides and/or lincosamides, including erm, mph, ABC-F, and lnu genes. Methods Nasopharyngeal swabs were systematically obtained at enrollment and weekly thereafter from children and adults enrolled in a household-based prospective cohort study in Lima, Peru. Samples were sequenced using the Illumina Respiratory Pathogen/ID AMR Panel to detect common respiratory bacteria and ARGs. We defined ‘any erm gene’ (erm) as the detection of any specific erm gene class, ‘any mph gene’ as detection of any specific mph gene class, ‘any ABC-F gene’ as any specific ABC-F gene class, and ‘any lnu gene’ as any specific lnu gene detection. We compared the prevalence of erm, mph, ABC-F and lnu gene colonization at enrollment among age groups (ages 0-4, 5-17, 18-44, and 45+ years) using the Fisher's exact test. We then compared the frequency of co-detection of two or more macrolide or lincosamide ARGs between both pediatric age groups (ages 0-17 years) and both adult age groups (18+ years). Results 114 individuals were included in this analysis (Table 1). At least one macrolide or lincosamide ARG was detected in 61/114 (53.5%) individuals. The prevalence of erm, mph, ABC-F, or lnu gene detection was similar among age groups (Figure 1). Two or more genes were co-detected in 45/114 (39.4%) individuals. Co-detections with two or more erm, mph, ABC-F, or lnu genes were more frequent in children 0-17 years compared to adults 18+ years (p=0.013) (Figure 2). Conclusion Conclusions: These preliminary results indicate that macrolide or lincosamide ARGs were commonly detected in healthy community-dwelling children and adults in Lima, Peru. The prevalence of erm, mph, ABC-F, and lnu genes was similar across age groups, and co-detection of ARGs was more common in children. Future studies will assess changes in ARG carriage over time, transmission among household members, and its clinical relevance. Disclosures Claudio Lanata, MD, MPH, CureVAc AG Germany: Grant/Research Support|HilleVac Inc.: Advisor/Consultant|HilleVac Inc.: Grant/Research Support Carlos G. Grijalva, MD, MPH, AHRQ: Grant/Research Support|CDC: Grant/Research Support|FDA: Grant/Research Support|Merck: Advisor/Consultant|NIH: Grant/Research Support|Syneos Health: Grant/Research Support

Ozone micron bubble pretreatment for antibiotic resistance genes reduction in hospital wastewater treatment

Ozone micron bubble (OMB) treatment offers a promising approach to effectively eliminate Antibiotic Resistance Genes (ARGs) from infectious medical wastewater and mitigate the threat of drug resistance transmission. This study evaluated the effectiveness of OMB treatment for reducing ARGs from infectious medical wastewater in laboratory and on-site pilot treatment setups. In part, the presence of antibiotic residues in a hospital wastewater treatment plant (WWTP) and the impact of hospital wastewater on the distribution of ARGs in a wastewater collection system were also investigated. The results of wastewater collection system survey revealed a high prevalence of ARGs in the system, particularly mcr-1, largely originating from medical wastewater discharges. Furthermore, analysis of antibiotic residues in the hospital wastewater treatment system showed significant accumulation, particularly of quinolone antibiotics, in the biomass of the biological oxidation tank, suggesting a potential risk of ARG proliferation within the system. Comparison of wastewater samples from domestic and hospital WWTPs revealed a relatively higher abundance of ARGs in the latter, with differences ranging from 2.2 to sixfold between corresponding locations in the treatment plants. Notably, the biological oxidation unit of both WWTPs exhibited a greater proportion of ARGs among all sampled points, indicating the potential proliferation of ARGs within the biomass of the treatment units. ARG degradation experiments showed that OMB treatment resulted in a significantly lower CT value (9.3 mg O3 L−1 min) compared to ozone coarse bubble treatment (102 mg O3 L−1 min) under identical test conditions. Moreover, the use of OMB on site significantly reduced the accumulation of ARGs in hospital wastewater, underscoring its potential as an effective solution for mitigating ARG spread.