Introgression of blast and bacterial blight disease resistance genes in a rice genotype ADT43 through marker assisted back cross breeding.

Bacterial Leaf Blight (Xanthomonas oryzae pv. oryzae) and blast (Magnaporthe oryzae) are the major biotic stresses around the rice-growing zones of the world. The development of resistant varieties through Marker Assisted Backcross Breeding is the utmost economical and eco-friendly method for achieving stable yield. Amongst the resistance genes recognized, Xa21 and Pi54 possess broad-spectrum resistance to many Xoo and blast strains around the world. In the present study, we have effectively introgressed a Bacterial Blight resistance gene (Xa21) and a blast resistance gene (Pi54) into susceptible variety ADT43 from RP-Bio-Patho-2 coupled with phenotypic selection for agronomic, cooking quality and grain traits through MABC. MABC was sustained till BC2F2 generation with specific markers pTA248 for Xa21 and Pi54MAS for Pi54 resistance genes. A set of SSR markers for parental polymorphism were utilized for maximum regaining of recurrent parent genome in each backcrossing. "Positive plants" from BC2F1 were selfed to generate BC2F2 and the homozygous lines for bacterial leaf blight and blast resistance genes were identified for further assessment.

Genomic insights of S. aureus associated with bovine mastitis in a high livestock activity region of Mexico.

IMPORTANCE: Bovine mastitis, predominantly associated with gram-positive Staphylococcus aureus, poses a significant threat to dairy cows, leading to a decline in milk quality and volume with substantial economic implications. OBJECTIVE: This study investigated the incidence, virulence, and antibiotic resistance of S. aureus associated with mastitis in dairy cows. METHODS: Fifty milk-productive cows underwent a subclinical mastitis diagnosis, and the S. aureus strains were isolated. Genomic DNA extraction, sequencing, and bioinformatic analysis were performed, supplemented by including 124 S. aureus genomes from cows with subclinical mastitis to enhance the overall analysis. RESULTS: The results revealed a 42% prevalence of subclinical mastitis among the cows tested. Genomic analysis identified 26 sequence types (STs) for all isolates, with Mexican STs belonging primarily to CC1 and CC97. The analyzed genomes exhibited multidrug resistance to phenicol, fluoroquinolone, tetracycline, and cephalosporine, which are commonly used as the first line of treatment. Furthermore, a similar genomic virulence repertoire was observed across the genomes, encompassing the genes related to invasion, survival, pathogenesis, and iron uptake. In particular, the toxic shock syndrome toxin (tss-1) was found predominantly in the genomes isolated in this study, posing potential health risks, particularly in children. CONCLUSION AND RELEVANCE: These findings underscore the broad capacity for antibiotic resistance and pathogenicity by S. aureus, compromising the integrity of milk and dairy products. The study emphasizes the need to evaluate the effectiveness of antibiotics in combating S. aureus infections.

Enhanced removal of ciprofloxacin and associated antibiotic-resistant genes from wastewater using a biological aeration filters in combination with Fe3O4-modified zeolite.

Antibiotics release into the water environment through sewage discharge is a significant environmental concern. In the present study, we investigated the removal of ciprofloxacin (CIP) in simulated sewage by biological aeration filter (BAF) equipped with Fe3O4-modified zeolite (Fe3O4@ZF). Fe3O4@ZF were prepared with impregnation method, and the Fe3O4 particles were successfully deposited on the surface of ZF in an amorphous form according to the results of XPS and XRD analysis. The modification also increased the specific surface area (from 16.22 m²/g to 22 m²/g) and pore volume (from 0.0047 cm³/g to 0.0063 cm³/g), improving the adsorption efficiency of antibiotics. Fe3O4 modified ZF improved the treatment performance significantly, and the removal efficiency of CIP in BAF-Fe3O4@ZF was 79%±2.4%. At 10ml/L CIP, the BAF-Fe3O4@ZF reduced the relative abundances of antibiotics resistance genes (ARGs) int, mexA, qnrB and qnrS in the effluent by 57.16%, 39.59%, 60.22%, and 20.25%, respectively, which effectively mitigate the dissemination risk of ARGs. The modification of ZF increased CIP-degrading bacteria abundance, such as Rhizobium and Deinococcus-Thermus, and doubled bacterial ATP activity, promoting CIP degradation. This study offers a viable, efficient method to enhance antibiotic treatment and prevent leakage via sewage discharge.

Leaching of antibiotic resistance genes and microbial assemblages following poultry litter applications in karst and non-karst landscapes.

Antibiotic resistance is increasingly recognized as a critical challenge affecting human, animal, and environmental health. Yet, environmental dynamics and transport of antibiotic resistance genes (ARGs) and microbial communities in karst and non-karst leachate following poultry litter land applications are not well understood. This study investigates impacts of broiler poultry litter application on the proliferation of ARGs (tetW, qnrS, ermB, sulI, and blaCTX-M-32), class 1 integron (intI1 i), and alterations in microbial communities (16S rRNA) within karst derived soils, which are crucial and under-researched systems in the global hydrological cycle, and non-karst landscapes. Using large, intact soil columns (45 cm diam. × 100 cm depth) from karst and non-karst landscapes, the role of preferential flow and ARG transport in leachate was enumerated following surface application of poultry litter and simulated rain events. This research demonstrated that in poultry litter amended karst soils, ARG (i.e., ermB and tetW) abundance in leachate increased 1.5 times compared to non-karst systems (p < 0.05), highlighting the influence of geological factors on ARG proliferation. Notably, microbial communities in karst soil leachate exhibited increased diversity and abundance, suggesting a potential linkage between microbial composition and ARG presence. Further, our correlation and network analyses identified relationships between leachate ARGs, microbial taxa, and physicochemical properties, underscoring the complex interplay in these environmentally sensitive areas. These findings illuminate the critical role of karst systems in shaping ARG abundance and pollutant dispersal and microbial community dynamics, thus emphasizing the need for landscape-specific approaches in managing ARG dissemination to the environment. This study provides a deeper understanding of hydrogeological ARG dynamics but also lays the groundwork for future research and strategies to mitigate ARG dissemination through targeted manure applications across agricultural landscapes.

Integrative and conjugative elements of Pasteurella multocida: Prevalence and signatures in population evolution.

Pasteurella multocida (P. multocida) is a bacterial pathogen responsible for a range of infections in humans and various animal hosts, causing significant economic losses in farming. Integrative and conjugative elements (ICEs) are important horizontal gene transfer elements, potentially enabling host bacteria to enhance adaptability by acquiring multiple functional genes. However, the understanding of ICEs in P. multocida and their impact on the transmission of this pathogen remains limited. In this study, 42 poultry-sourced P. multocida genomes obtained by high-throughput sequencing together with 393 publicly available P. multocida genomes were used to analyse the horizontal transfer of ICEs. Eighty-two ICEs were identified in P. multocida, including SXT/R391 and Tn916 subtypes, as well as three subtypes of ICEHin1056 family, with the latter being widely prevalent in P. multocida and carrying multiple resistance genes. The correlations between insertion sequences and resistant genes in ICEs were also identified, and some ICEs introduced the carbapenem gene blaOXA-2 and the bleomycin gene bleO to P. multocida. Phylogenetic and collinearity analyses of these bioinformatics found that ICEs in P. multocida were transmitted vertically and horizontally and have evolved with host specialization. These findings provide insight into the transmission and evolution mode of ICEs in P. multocida and highlight the importance of understanding these elements for controlling the spread of antibiotic resistance.

Screening of vancomycin resistance-associated genes in methicillin-resistant Staphylococcus aureus isolates from cattle, sheep and goats in northwestern Iran.

Staphylococcus aureus is an important pathogen causing a wide range of diseases in both humans and animals. The aim of this research was to screen the vancomycin resistance-associated genes in methicillin-resistant Staphylococcus aureus (MRSA) isolates from animals. A total of 400 nasal swab samples were collected from cattle, goats and sheep between February and August 2022 from both industrial and traditional livestock farms in West Azerbaijan province, Iran. Then, nasal swabs were cultured on mannitol salt agar and molecular analysis was performed after bacteriological examination to confirm the presence of S. aureus. The MecA gene was used to detect MRSA isolates, and two important vancomycin resistance-associated genes, namely vanA and vanB, were searched in the isolates. Out of 400 nasal swabs, 69 samples had S. aureus; of which seven isolates were resistant against methicillin. No vancomycin resistance-associated genes were detected in the MRSA isolates. Based on these findings, vancomycin could be used to treat infections caused by this bacterium.

Deciphering Multidrug-Resistant Plasmids in Disinfection Residual Bacteria from a Wastewater Treatment Plant.

Current disinfection processes pose an emerging environmental risk due to the ineffective removal of antibiotic-resistant bacteria, especially disinfection residual bacteria (DRB) carrying multidrug-resistant plasmids (MRPs). However, the characteristics of DRB-carried MRPs are poorly understood. In this study, qPCR analysis reveals that the total absolute abundance of four plasmids in postdisinfection effluent decreases by 1.15 log units, while their relative abundance increases by 0.11 copies/cell compared to investigated wastewater treatment plant (WWTP) influent. We obtain three distinctive DRB-carried MRPs (pWWTP-01-03) from postdisinfection effluent, each carrying 9-11 antibiotic-resistant genes (ARGs). pWWTP-01 contains all 11 ARGs within an ∼25 Kbp chimeric genomic island showing strong patterns of recombination with MRPs from foodborne outbreaks and hospitals. Antibiotic-, disinfectant-, and heavy-metal-resistant genes on the same plasmid underscore the potential roles of disinfectants and heavy metals in the coselection of ARGs. Additionally, pWWTP-02 harbors an adhesin-type virulence operon, implying risks of both antibiotic resistance and pathogenicity upon entering environments. Furthermore, some MRPs from DRB are capable of transferring and could confer selective advantages to recipients under environmentally relevant antibiotic pressure. Overall, this study advances our understanding of DRB-carried MRPs and highlights the imminent need to monitor and control wastewater MRPs for environmental security.

Antibiotic Resistance in Plant Pathogenic Bacteria: Recent Data and Environmental Impact of Unchecked Use and the Potential of Biocontrol Agents as an Eco-Friendly Alternative.

The economic impact of phytopathogenic bacteria on agriculture is staggering, costing billions of US dollars globally. Pseudomonas syringae is the top most phytopathogenic bacteria, having more than 60 pathovars, which cause bacteria speck in tomatoes, halo blight in beans, and so on. Although antibiotics or a combination of antibiotics are used to manage infectious diseases in plants, they are employed far less in agriculture compared to human and animal populations. Moreover, the majority of antibiotics used in plants are immediately washed away, leading to environmental damage to ecosystems and food chains. Due to the serious risk of antibiotic resistance (AR) and the potential for environmental contamination with antibiotic residues and resistance genes, the use of unchecked antibiotics against phytopathogenic bacteria is not advisable. Despite the significant concern regarding AR in the world today, there are inadequate and outdated data on the AR of phytopathogenic bacteria. This review presents recent AR data on plant pathogenic bacteria (PPB), along with their environmental impact. In light of these findings, we suggest the use of biocontrol agents as a sustainable, eco-friendly, and effective alternative to controlling phytopathogenic bacteria.

Unraveling the mechanism of norfloxacin removal and fate of antibiotics resistance genes (ARGs) in the sulfur-mediated autotrophic denitrification via metagenomic and metatranscriptomic analyses.

The co-contamination of antibiotics and nitrogen has attracted widespread concerns due to its potential harm to ecological safety and human health. Sulfur-driven autotrophic denitrification (SAD) with low sludge production rate was adopted to treat antibiotics laden-organic deficient wastewater. Herein, a lab-scale sequencing batch reactor (SBR) was established to explore the simultaneous removal of nitrate and antibiotics, i.e. Norfloxacin (NOR), as well as microbial response mechanism of SAD sludge system towards NOR exposure. About 80.78 % of NOR was removed by SAD sludge when the influent NOR level was 0.5 mg/L, in which biodegradation was dominant removal route. The nitrate removal efficiency decreased slightly from 98.37 ± 0.58 % to 96.58 ± 1.03 % in the presence of NOR. Thiobacillus and Sulfurimonas were the most abundant sulfur-oxidizing bacteria (SOB) in SAD system, but Thiobacillus was more sensitive to NOR. The up-regulated genes related to Xenobiotics biodegradation and metabolism and CYP450 indicated the occurrence of NOR biotransformation in SAD system. The resistance of SAD sludge to the exposure of NOR was mainly ascribed to antibiotic efflux. And the effect of antibiotic inactivation was enhanced after long-term fed with NOR. The NOR exposure resulted in the increased level of antibiotics resistance genes (ARGs) and mobile genetic elements (MGEs). Besides, the enhanced ARG-MGE co-existence patterns further reveals the higher horizontal mobility potential of ARGs under NOR exposure pressures. The most enriched sulfur oxidizing bacterium Thiobacillus was a potential host for most of ARGs. This study provides a new insight for the treatment of NOR-laden wastewater with low C/N ratio based on the sulfur-mediated biological process.

Occurrences and implications of pathogenic and antibiotic-resistant bacteria in different stages of drinking water treatment plants and distribution systems.

Different stages of drinking water treatment plants (DWTPs) play specific roles in diverse contaminants' removal present in natural water sources. Although the stages are recorded to promote adequate treatment of water, the occurrence of pathogenic bacteria (PB) and antibiotic-resistant bacteria (ARB) in the treated water and the changes in their diversity and abundance as it passed down to the end users through the drinking water distribution systems (DWDSs), is a great concern, especially to human health. This could imply that the different stages and the distribution system provide a good microenvironment for their growth. Hence, it becomes pertinent to constantly monitor and document the diversity of PB and ARB present at each stage of the treatment and distribution system. This review aimed at documenting the occurrence of PB and ARB at different stages of treatment and distribution systems as well as the implication of their occurrence globally. An exhaustive literature search from Web of Science, Science-Direct database, Google Scholar, Academic Research Databases like the National Center for Biotechnology Information, Scopus, and SpringerLink was done. The obtained information showed that the different treatment stages and distribution systems influence the PB and ARB that proliferate. To minimize the human health risks associated with the occurrence of these PB, the present review, suggests the development of advanced technologies that can promote quick monitoring of PB/ARB at each treatment stage and distribution system as well as reduction of the cost of environomics analysis to promote better microbial analysis.

Removal efficiency of antibiotic residues, antibiotic resistant bacteria, and genes across parallel secondary settling tank and membrane bioreactor treatment trains in a water reclamation plant.

Antimicrobial resistance is recognized as a potent threat to human health. Wastewater treatment facilities are viewed as hotspots for the spread of antimicrobial resistance. This study provides comprehensive data on the occurrences of 3 different antibiotic resistant opportunistic pathogens (with resistance to up to 5 antibiotics), 13 antibiotic resistant genes and intI1, and 22 different antimicrobial residues in a large water reclamation plant (176 million gallons per day) that runs a conventional Modified Ludzack-Ettinger (MLE) reactor followed by a secondary settling tank (SST) and membrane bioreactor (MBR) in parallel. All the antibiotic resistant bacteria and most of the antibiotic resistance genes were present in the raw influent, ranging from 2.5 × 102-3.7 × 106 CFU/mL and 1.2× 10-1-6.5 × 1010 GCN/mL, respectively. MBR outperformed the SST system in terms of ARB removal as the ARB targets were largely undetected in MBR effluent, with log removals ranging from 2.7 to 6.8, while SST only had log removals ranging from 0.27 to 4.6. Most of the ARG concentrations were found to have significantly higher in SST effluent than MBR permeate, and MBR had significantly higher removal efficiency for most targets (p < 0.05) except for sul1, sul2, blaOXA48, intI1 and 16S rRNA genes (p > 0.05). As for the antibiotic residues (AR), there was no significant removal from the start to the end of the treatment process, although MBR had higher removal efficiencies for azithromycin, chloramphenicol, erythromycin, erythromycin-H2O, lincomycin, sulfamethoxazole and triclosan, compared to the SST system. In conclusion, MBR outperformed SST in terms of ARB and ARGs removal. However low removal efficiencies of most AR targets were apparent.

Effect of ciprofloxacin on the one-stage partial nitrification and anammox biofilm system: A multivariate analysis focusing on size-fractionated organic components.

The impact of ciprofloxacin (CIP) in the partial nitrification and anammox biofilm system was investigated by multivariate analysis, focusing on size-fractionated organic components. The CIP dose of 10 µg/L did not inhibit the total nitrogen (TN) removal efficiency, even though the abundance of antibiotic resistant genes (ARGs) (i.e., qnrD, qnrB, qnrA, qnrS, and arcA) was elevated. However, a gradual higher CIP dosing up to 100 µg/L inhibited the TN removal efficiency, while the abundance of ARGs was still increased. Moreover, both the TN removal efficiency and the abundant ARGs were dwindled at 470 µg/L of CIP. As the CIP dose increased from 0 to 100 µg/L, the abundance of high molecular weight (MW) fractions (14,000 to 87,000 Da; 1000 to 14,000 Da) and humic/fulvic acid-like components in the soluble extracellular polymeric substances (HSS) decreased, with more increases of low MW (84-1000 Da; less than 84 Da) fractions and soluble microbial by-products in soluble extracellular polymeric substances (SMPS). Continuously increasing the CIP dose till 470 µg/L, an inverse trend of the changes of these organic components was noted, along with clear reductions of the microbial diversity and richness, and the abundance of key functional genes responsible for nitrogen removal. The predominance of functional gene amoA (related with ammonia oxidizing bacteria) was more significantly with more distribution of SMPS with relatively low MW and less distribution of HSS with relatively high MW, as well as polymer decomposing microorganisms such as Bryobacteraceae and the unclassified Saprospirales.

The synergistic effect of periodate/ferrate (VI) system on disinfection of antibiotic resistant bacteria and removal of antibiotic resistant genes: The dominance of Fe (IV)/Fe (V).

The proliferation of antibiotic resistant genes (ARGs) and antibiotic resistant bacteria (ARB) caused by antibiotic abuse has raised concerns about the global infectious-disease crisis. This study employed periodate (PI)/ferrate (VI) (Fe (VI)) system to disinfect Gram-negative ARB (Escherichia coli DH5α) and Gram-positive bacteria (Bacillus subtilis ATCC6633). The PI/Fe (VI) system could inactivate 1 × 108 CFU/mL of Gram-negative ARB and Gram-positive bacteria by 4.0 and 2.8 log in 30 min. Neutral and acidic pH, increase of PI dosage and Fe (VI) dosage had positive impacts on the inactivation efficiency of ARB, while alkaline solution and the coexistence of 10 mM Cl-, NO3-, SO42- and 20 mg/L humic acid had slightly negative impacts. The reactive species generated by PI/Fe (VI) system could disrupt the integrity of cell membrane and wall, leading to oxidative stress and lipid peroxidation. Intracellular hereditary substance, including DNA and ARGs (tetA), would leak into the external environment through damaged cells and be degraded. The electron spin resonance analysis and quenching experiments indicated that Fe (IV)/Fe (V) played a leading role in disinfection. Meanwhile, PI/Fe (VI) system also had an efficient removal effect on sulfadiazine, which was expected to inhibit the ARGs transmission from the source.

Antibiotics soil-solution chemistry: A review of environmental behavior and uptake and transformation by plants.

The increased use of antibiotics by humans for various purposes has left the environment polluted. Antibiotic pollution remediation is challenging because antibiotics exist in trace amounts and only highly sensitive detection techniques could be used to quantify them. Nevertheless, their trace quantity is not a hindrance to their transfer along the food chain, causing sensitization and the development of antibiotic resistance. Despite an increase in the literature on antibiotic pollution and the development and transfer of antibiotic-resistant genes (ARGs), little attention has been given to the behavior of antibiotics at the soil-solution interface and how this affects antibiotic adsorption-desorption interactions and subsequent uptake and transformation by plants. Thus, this review critically examines the interactions and possible degradation mechanisms of antibiotics in soil and the link between antibiotic soil-solution chemistry and uptake by plants. Also, different factors influencing antibiotic mobility in soil and the transfer of ARGs from one organism to another were considered. The mechanistic and critical analyses revealed that: (a) the charge characteristics of antibiotics at the soil-root interface determine whether they are adsorbed to soil or taken up by plants; (b) antibiotics that avoid soil colloids and reach soil pore water can be absorbed by plant roots, but their translocation to the stem and leaves depends on the ionic state of the molecule; (c) few studies have explored how plants adapt to antibiotic pollution and the transformation of antibiotics in plants; and (d) the persistence of antibiotics in cropland soils can be influenced by the content of soil organic matter, coexisting ions, and fertilization practices. Future research should focus on the soil/solution-antibiotic-plant interactions to reveal detailed mechanisms of antibiotic transformation by plants and whether plant-transformed antibiotics could be of environmental risk.

Using Quantitative Polymerase Chain Reaction (qPCR) to Identify a Myriad of Carbapenemase Genes in Fresh Cow Dung in Bangladesh.

Introduction The emergence of antimicrobial resistance (AMR) is driven by the selection pressure of frequent uses of antimicrobial agents in healthcare, the food chain, agriculture, fishery, and the food animal industry, which poses a serious health risk for transmission-linked humans and the surrounding environment. Livestock, particularly cattle, play an essential role in the food sector in Bangladesh. The food-animal chains can be the potential routes of exposure to AMR-microorganisms for every domain of one health. Antimicrobial resistance genes (ARGs) can impart a reservoir of AMR within the food supply chain, even without pathogenic microorganisms. This study investigated the history of infection for the last six-month period of antimicrobials utilized in cattle farms and the distribution of selected carbapenemase resistance genes, namely, bla-KPC, bla-IMP, bla-VIM, bla-NDM-1, bla-SIM, bla-GIM, bla-SPM, and bla-SME, in cattle feces in Bangladesh. Methods A cross-sectional study was designed to analyze ARGs in fresh cow dung samples collected from commercial farms and individual houses in four Bangladesh districts, namely, Dhaka, Gazipur, Manikganj, and Tangail. Types of cattle breeds, their existing diseases, recent antimicrobial uses, and vaccine uses were recorded. DNA was extracted from each cow dung sample using commercial kits (Qiagen GmbH, Germany). Real-time quantitative polymerase chain reaction (RT-qPCR) was employed to assess the eight carbapenem resistance genes in the extracted DNA. The eight carbapenem resistance genes in the extracted DNA were assessed by RT-qPCR using the qTOWER3 thermal cycler (Analytik Jena GmbH, Konrad-Zuse-Straße 1, 07745 Jena, Germany). Results Group A carbapenemase, bla-KPC, was detected in 66.7% of the samples. However, no bla-SME was identified in all of the test samples. Group B metallo carbapenemase, bla-IMP, bla-NDM-1, bla-VIM, bla-SIM, bla-GIM, and bla-SPM, were in 66.7% (80/120), 49.2% (59/120), 48.3% (58/120), 68.3% (82/120), 58.3% (70/120), and 12.5% (15/120), respectively. Only 8.3% of the tested samples contained no MBL gene; 10% carried a single-type carbapenemase gene; and the remaining 81.7% carried two or more carbapenemase genes concurrently. Co-carriage of four or more genes was found in over 59% of samples. As many as seven genes were found together in 6.7% of samples. ARG detection in commercial cattle samples and household feces is not statistically significant. Conclusions Substantial carbapenem-resistance ARGs were detected in commercially farmed cow dung and household cattle samples. Frequent use of antibiotics for cattle for treatment and prophylactic purposes may influence the high acquisition of ARGs. Bangladeshi cattle farms are reservoirs and routes of AMR, posing a significant threat to the country's public health.

Gut resistome profiling reveals high diversity and fluctuations in pancreatic cancer cohorts.

Background: Pancreatic cancer is one of the deadliest cancer, with a 5-year overall survival rate of 11%. Unfortunately, most patients are diagnosed with advanced stage by the time they present with symptoms. In the past decade, microbiome studies have explored the association of pancreatic cancer with the human oral and gut microbiomes. However, the gut microbial antibiotic resistance genes profiling of pancreatic cancer patients was never reported compared to that of the healthy cohort. Results: In this study, we addressed the gut microbial antibiotic resistance genes profile using the metagenomic data from two online public pancreatic cancer cohorts. We found a high degree of data concordance between the two cohorts, which can therefore be used for cross-sectional comparisons. Meanwhile, we used two strategies to predict antibiotic resistance genes and compared the advantages and disadvantages of these two approaches. We also constructed microbe-antibiotic resistance gene networks and found that most of the hub nodes in the networks were antibiotic resistance genes. Conclusions: In summary, we describe the panorama of antibiotic resistance genes in the gut microbes of patients with pancreatic cancer. We hope that our study will provide new perspectives on treatment options for the disease.

Bacteriological and molecular study of fosfomycin resistance in uropathogenic Escherichia coli.

The identification of genes associated with resistance has the potential to facilitate the development of novel diagnostic tests and treatment methods. The objective of this study was to examine the antibiotic resistance and Fosfomycin resistance genes in uropathogenic Escherichia coli (UPEC) in patients in Baghdad, Iraq. After analyzing 250 urine samples using various identification methods, including the examination of morphological characteristics, biochemical tests, and genetic detection, it was determined that E. coli was the most common bacteria present, accounting for 63.6% of the samples. Antibiotic susceptibility testing showed a significant prevalence of resistance to various antibiotics, with 99.3% of E. coli isolates exhibiting multiple drug resistance (MDR). Fosfomycin showed antibacterial properties against UPEC. The minimum inhibitory concentration (MIC) ranged from 512 to 1024 µg/mL, while the minimum bactericidal concentration (MBC) was 2048 µg/mL. In the time-kill assay, fosfomycin was effective against fosfomycin-resistant isolates within 8-12 h. The genetic determinants associated with fosfomycin resistance were examined through the utilization of polymerase chain reaction (PCR). The findings indicated that the genes murA, glpT, and cyaA were detected in all the isolates when genomic DNA was used as a template. However, all the tests yielded negative results when plasmid was used as a template. The genes fosA3 and fosA4 were detected in 8.6% and 5% of the isolates when genomic DNA was used as a template. When plasmid was used as a template, the genes fosA3 and fosA4 were found in 5.7% and 2.9% of the isolates, respectively. In conclusion, there is an increasing problem with antibiotic resistance in UPEC, with elevated rates of resistance to several antibiotics. The study also offers novel insights into the genetic foundation of fosfomycin resistance in UPEC.

Bacteria populating freshly appeared supraglacial lake possess metals and antibiotic-resistant genes.

Antibiotic resistance (AR) has been extensively studied in natural habitats and clinical applications. AR is mainly reported with the use and misuse of antibiotics; however, little is known about its presence in antibiotic-free remote supraglacial lake environments. This study evaluated bacterial strains isolated from supraglacial lake debris and meltwater in Dook Pal Glacier, northern Pakistan, for antibiotic-resistant genes (ARGs) and metal-tolerant genes (MTGs) using conventional PCR. Several distinct ARGs were reported in the bacterial strains isolated from lake debris (92.5%) and meltwater (100%). In lake debris, 57.5% of isolates harbored the blaTEM gene, whereas 58.3% of isolates in meltwater possessed blaTEM and qnrA each. Among the ARGs, qnrA was dominant in debris isolates (19%), whereas in meltwater isolates, qnrA (15.2%) and blaTEM (15.2%) were dominant. ARGs were widely distributed among the bacterial isolates and different bacteria shared similar types of ARGs. Relatively greater number of ARGs were reported in Gram-negative bacterial strains. In addition, 92.5% of bacterial isolates from lake debris and 83.3% of isolates from meltwater harbored MTGs. Gene copA was dominant in meltwater isolates (50%), whereas czcA was greater in debris bacterial isolates (45%). Among the MTGs, czcA (18.75%) was dominant in debris strains, whereas copA (26.0%) was greater in meltwater isolates. This presents the co-occurrence and co-selection of MTGs and ARGs in a freshly appeared supraglacial lake. The same ARGs and MTGs were present in different bacteria, exhibiting horizontal gene transfer (HGT). Both positive and negative correlations were determined between ARGs and MTGs. The research provides insights into the existence of MTGs and ARGs in bacterial strains isolated from remote supraglacial lake environments, signifying the need for a more detailed study of bacteria harboring ARGs and MTGs in supraglacial lakes.

Combined applications of UV and chlorine on antibiotic resistance control: A critical review.

Environmental health problems caused by antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) have become a global concern. ARB and ARGs have been continuously detected in various water environments, which pose a new challenge for water quality safety assurance. Disinfection is a key water treatment process to eliminate pathogenic microorganisms in water, and combined chlorine and UV processes (the UV/Cl2 process, the UV-Cl2 process, and the Cl2-UV process) are considered potential disinfection methods to control antibiotic resistance. This review documented the efficacy and mechanism of combined UV and chlorine processes for the control of antibiotic resistance, as well as the effects of chlorine dose, solution pH, UV wavelength, and water matrix on the effectiveness of the processes. There are knowledge gaps in research on the combined chlorine and UV processes for antibiotic resistance control, in particular the UV-Cl2 process and the Cl2-UV process. In addition, changes in the structure of microbial communities and the distribution of ARGs, which are closely related to the spread of antibiotic resistance in the water, induced by combined processes were also addressed. Whether these changes could lead to the re-transmission of antibiotic resistance and harm human health may need to be further evaluated.