Spread Of Antibiotic Resistance Research Articles

Evaluation of antibiotic resistance in bacterial strains isolated from sewage of slaughterhouses

Abstract Background The frequent and incorrect use of antibiotics in animal husbandry has led to the spread of antimicrobial resistance. The issue should be addressed in a One Health vision, since human and animal health, as well as the environment are interconnected. Wastewater from slaughterhouses can be contaminated with multidrug-resistant bacteria, representing a possible cross-contamination route. This study evaluated the presence of antibiotic-resistant bacteria in wastewater from slaughterhouses to highlight their role in the spread of antibiotic resistance. Methods In total, 18 out 35 slaughterhouses in Sicily (Italy) were considered. For each wastewater system the samples were collected before any treatment, and cultured within 24 h of sampling. The isolates were identified by API20NE, API20E profiles (bioMerieux, France). Using the Kirby Bauer test, the isolated strains were classified as resistant (R), intermediately resistant (I), or sensitive (S) to the tested antibiotics. Results Proteus mirabilis (85.7%) and Peudomonas aeruginosa (27.3%) were the most frequently isolated microorganisms, followed by Enterobacter cloacae, Aeromonas hydrophila, and Citrobacter freundii. The most resistant strains belonged to Enterobacter spp., which showed the highest resistance rate for macrolides, penicillins and cephalosporins. Aeromonas spp. was resistant to carbapenems while E. coli showed the highest resistance to colistine. Finally, Citrobacter spp. was completely resistant to macrolides, rifampicin, and tetracycline. Conclusions High resistance levels were detected for some antibiotics widely used in human medicine such as macrolides, penicillins, and cephalosporins. Resistance to carbapenems and colistine, which are now considered key drugs in human medicine for the treatment of severe multidrug-resistant infections, was also reported. Thus, continuous monitoring on the correct use of antibiotics in animal husbandry is necessary. Key messages • Wastewater from slaughterhouses may be a vehicle of antibiotic-resistant bacteria. • The One Health approach should be used for the management of health security, food safety and antimicrobial resistance.

Detection of multidrug resistant Vibrio parahaemolyticus and anti-Vibrio Streptomyces sp. MUM 178J

The growing global population has increased the demand for seafood, making the aquaculture industry a vital food source. However, climate change has negatively impacted the industry as natural inhabitants of aquatic environments such as Vibrio parahaemolyticus are thriving in the warming waters. These foodborne pathogens can cause disease in marine animals, resulting in lowered production rates and substantial economic losses. V. parahaemolyticus is transmitted from these marine animals in aquaculture to humans via raw or undercooked seafood, resulting in gastroenteritis outbreaks. In addition, the extensive use of antibiotics in aquaculture to treat infections within marine animals has led to the development of multidrug-resistant (MDR) V. parahaemolyticus, which threatens the effectiveness of antimicrobial treatments. Thus, it is vital to explore the alternatives of antibiotics in aquaculture to manage the spread of antibiotic resistance. This study aimed to investigate the prevalence of MDR V. parahaemolyticus to provide insight into the current antibiotic resistance patterns of this pathogen and to determine potential anti-Vibrio properties of Streptomyces MUM 178J which was previously isolated from the soils of a mangrove forest in Sarawak, Malaysia. Colony morphology and toxR-assay indicated that all samples tested positive for V. parahaemolyticus. Further identification with genomic analyses confirmed that 64% (64/100) of the isolates were V. parahaemolyticus. The multiple antibiotic resistance index (MAR) of the isolates ranged between 0.07 and 0.57, with 81% (52/64) of the isolates resistant to more than one antibiotic. The isolates were most resistant to ampicillin (98.4%), followed by ceftazidime (53.1%). In contrast, the isolates were highly susceptible to nalidixic acid (98.4%), tetracycline (93.8%), and sulfamethoxazole/trimethoprim (90.6%). They also demonstrated susceptibilities of 89.1% to levofloxacin, oxytetracycline, and gentamicin. Streptomyces sp. MUM 178J exhibited antagonistic effects on select V. parahaemolyticus strain, RP0132, with a minimum inhibitory concentration of 12.5 mg/mL and a minimum bactericidal concentration of 50 mg/mL.

The Impact of COVID-19 on Knowledge, Beliefs, and Practices of Ni-Vanuatu Health Workers Regarding Antibiotic Prescribing and Antibiotic Resistance, 2018 and 2022: A Mixed Methods Study.

Antimicrobial resistance (AMR) is included in the ten most urgent global public health threats. Global evidence suggests that antibiotics were over prescribed during the early waves of the COVID-19 pandemic, particularly in low- and middle-income countries. Inappropriate use of antibiotics drives the emergence and spread of antibiotic resistance. This study aimed to examine the impact of COVID-19 on Ni-Vanuatu health worker knowledge, beliefs, and practices (KBP) regarding antibiotic prescribing and awareness of antibacterial AMR. A mixed methods study was conducted using questionnaires and in-depth interviews in 2018 and 2022. A total of 49 respondents completed both baseline (2018) and follow-up (2022) questionnaires. Knowledge scores about prescribing improved between surveys, although health workers were less confident about some prescribing activities. Respondents identified barriers to optimal hand hygiene performance. More than three-quarters of respondents reported that COVID-19 influenced their prescribing practice and heightened their awareness of ABR: "more careful", "more aware", "stricter", and "need more community awareness". Recommendations include providing ongoing continuing professional development to improve knowledge, enhance skills, and maintain prescribing competency; formalising antibiotic stewardship and infection, prevention, and control (IPC) programmes to optimise prescribing and IPC practices; and raising community awareness about ABR to support more effective use of medications.

Evaluation of Antibiotic Resistant Bacteria from Organic Fertilized Farm Soils and Waterleaf (Talinum triangulare) in Aluu, Rivers State, Nigeria

The use of antibiotics in agriculture is believed to contribute to the spread of antibiotic resistance, and consumption of vegetables represents a route of direct human exposure to resistant bacteria found in soil. This study was carried out to isolate and characterize antibiotic resistant bacteria from poultry dropping fertilized farm soils in Aluu community Rivers State. Thirty-six (36) soil and waterleaf (Talinum triangulare) samples were collected for a period of three months from the vegetable farms and subjected to standard microbiological procedures such as standard plate counts, identification, sensitivity testing using Kirby-Bauer disk diffusion method and molecular identification. The total heterotrophic bacterial (THB), Staphylococcal, and total coliform counts ranged from2.72±0.52x106 to 7.30±3.54x106Cfu/g; 0x105to 4.30±0.28x105Cfu/g; 0x105 to 21.40±2.26x105Cfu/g and 2.65±0.21x105 to 3.10±0.85x105Cfu/g for FarmsA, B and C respectively. There was a significant difference (p˂0.05) in the total heterotrophic, coliform bacterial count but no significant difference in Staphylococcal and Salmonella-Shigella count between the different vegetable farms sampled in month one. THB, Staphylococcal, Faecal coliform (FC), coliform, Salmonella-Shigella counts ranged from3.80±1.83x106 to 4.69±1.69x106cfu/g; 1.08±0.04x105 to 1.40±0.11x105Cfu/g; 2.00±0.42x104 to 8.30±2.12x104Cfu/g; 3.95±0.21x105 to 5.95±0.21x105Cfu/g and 1.20±0.28x104to 2.40±0.85x104Cfu/g for FarmsA and B respectively. There was no significant difference (p˂0.05) in the THB, Salmonella-Shigella, Total coliform (TC) counts, but there was a significant difference in the Staphylococcal and faecal coliform counts between the different vegetable farms sampled for month two. The bacterial isolates identified were as follows; Escherichia coli, Enterobacter spp, Shigella spp, Salmonella spp, Pseudomonas spp Proteus spp, Staphylococcus aureus, Bacillus subtilis, Bacillus licheniformis, Serratia marcesens and Serratia nematodiphila. Forty-six (46) bacterial isolates were isolated from the soils and vegetables. Escherichia coli had the highest occurrence (75%) and Bacillus spp (9.09%) had the least occurrence. The susceptibility pattern of Bacillus spp, Staphylococcus spp, Enterobacter spp, Salmonella spp, Escherichia coli, Shigella spp, Pseudomonas sppand Proteus sppwere all susceptible to Ofloxacin, and gentamicin (100%) and resistant to Ceftazidime, Cefixime and Augmentin (100%). Hundred-percent (100%) of the bacterial isolates had multidrug resistance index greater than 0.2 and QnrA resistant gene were found in the resistant bacterial isolates. In conclusion, the use of antibiotic indiscriminately for agricultural purposes should be discouraged because of multiple antibiotic resistance.

Natural transformation and cell division delay in competent Staphylococcus aureus.

Genetic competence for natural transformation, considered one of the three main mechanisms leading to horizontal gene transfer in bacteria, is able to promote evolution, through genomic plasticity, and foster antibiotic resistance and virulence factors spreading. Conserved machinery and actors required to perform natural transformation have been shown to accumulate at different cellular localizations depending on the model organism considered. In this study, we investigate the transformation apparatus composition, localization, and dynamics in the human pathogen Staphylococcus aureus. We particularly show that most of the natural transformation actors co-localize in clusters. We also reveal that the localization of natural transformation proteins is dynamic, following the cell cycle. Ultimately, the natural transformation apparatus is preferentially established in the vicinity of the division septum. All these results demonstrate that DNA binding, uptake, and recombination are spatially and temporally coordinated to ensure S. aureus natural transformation. Finally, we hypothesize that S. aureus competent cells would initiate and then block cell division to ensure the success of natural transformation before the final constriction of the cytokinetic ring. IMPORTANCE Natural transformation, considered one of the three main mechanisms leading to horizontal gene transfer in bacteria, is able to promote genomic plasticity and foster antibiotic resistance spreading. Conserved machinery and actors required to perform natural transformation have been shown to accumulate at different cellular localizations depending on the model organism considered. Here, we show in the human pathogen Staphylococcus aureus that DNA binding, uptake, and recombination are spatially and temporally coordinated to ensure S. aureus natural transformation. We also reveal that localization of natural transformation proteins occurs in the vicinity of the division septum allowing S. aureus competent cells to block cell division to ensure the success of natural transformation before the final constriction of the cytokinetic ring.

Poultry manure-derived microorganisms as a reservoir and source of antibiotic resistance genes transferred to soil autochthonous microorganisms

Animal husbandry is increasing yearly due to the growing demand for meat and livestock products, among other reasons. To meet these demands, prophylactic antibiotics are used in the livestock industry (i.e., poultry farming) to promote health and stimulate animal growth. However, antibiotics are not fully metabolized by animals, and they are evacuated to the environment with excreta. Animal manure is used as fertilizer to reduce the volume of waste generated in the livestock sector. However, manure often contains microorganisms harboring antibiotic resistance genes (ARGs). Then, the microbiome of manure applicate to the soil may contribute to the spread of antibiotic resistance in the environment, including autochthonous soil-dwelling microorganisms. The present study was conducted during the crops growing season in Poland (May to September 2019) to determine the influence of poultry manure as well as poultry manure supplemented with selected antibiotics on the diversity of the soil microbiome in treatments that had not been previously fertilized with manure and the ability of antibiotic-resistant bacteria to transfer ARGs to other soil bacteria. Antibiotic concentrations were elevated at the beginning of the study and decreased over time. Poultry manure induced significant changes in the structure of microbial communities in soil; the diversity of the soil microbiome decreased, and the abundance of bacterial genera Bradyrhizobium, Streptomyces, and Pseudomonas, which are characteristic of the analyzed manure, increased. Over time, soil microbial diversity was restored to the state observed before the application of manure. Genes conferring resistance to multiple drugs as well as genes encoding resistance to bacitracin and aminoglycosides were the most frequently identified ARGs in the analyzed bacteria, including on mobile genetic elements. Multidrug resistance was observed in 17 bacterial taxa, whereas ARGs were identified in 32 bacterial taxa identified in the soil microbiome. The results of the study conclude that the application of poultry manure supplemented with antibiotics initially affects soil microbiome and resistome diversity but finally, the soil shows resilience and returns to its original state after time, with most antibiotic resistance genes disappearing. This phenomenon is of great importance in sustainable soil health after manure application.

One Earth: The Equilibrium between the Human and the Bacterial Worlds.

Misuse and abuse of antibiotics on humans, cattle, and crops have led to the selection of multi-resistant pathogenic bacteria, the most feared 'superbugs'. Infections caused by superbugs are progressively difficult to treat, with a subsequent increase in lethality: the toll on human lives is predicted to reach 10 million by 2050. Here we review three concepts linked to the growing resistance to antibiotics, namely (i) the Resistome, which refers to the collection of bacterial genes that confer resistance to antibiotics, (ii) the Mobilome, which includes all the mobile genetic elements that participate in the spreading of antibiotic resistance among bacteria by horizontal gene transfer processes, and (iii) the Nichome, which refers to the set of genes that are expressed when bacteria try to colonize new niches. We also discuss the strategies that can be used to tackle bacterial infections and propose an entente cordiale with the bacterial world so that instead of war and destruction of the 'fierce enemy' we can achieve a peaceful coexistence (the One Earth concept) between the human and the bacterial worlds. This, in turn, will contribute to microbial biodiversity, which is crucial in a globally changing climate due to anthropogenic activities.

Биологические свойства штаммов L. helveticus

The biological properties of three strains of L. helvetcus were studied. All studied strains metabolize D-galactose. The L. helveticus AB strain utilizes D-glucose, D-fructose, N-acetylglucosamine, and D-trehalose; L. helveticus 20T — D-mannose, N-acetylglucosamine; L. helveticus H-9 — D-glucose, D-lactose, D-trehalose. All strains showed high β-galactosidase activity, as well as the activity of acid phosphatase, naphthol-AS-BI hydrolase, leucine arylamidase, and cystine arylamidase. For L. helveticus 20T and L. helveticus AB strains, valine arylamidase activity was found. All strains are sensitive to gentamicin, ampicillin, tetracycline, azithromycin, lincomycin, chloramphenicol. The data obtained indicate the safety of using strains as part of starter cultures and as producers of metabolite additives in terms of reducing the risk of spreading antibiotic resistance.

Investigation of papA, papC, and papG virulence genes revealed their association with antimicrobial resistance among uropathogenic Escherichia coli strains isolated from patients in Thi-Qar province, Iraq

Infection of the urinary tract is one of the more common infections in the people of the world, which is more common in women due to the anatomical structure of the woman's body. The main cause of this infection is uropathogenic E. coli, followed by Klebsiella pneumoniae. This disease is controlled and treated by antibiotics, but one of the most important concerns in today's world is the spread of antibiotic resistance in different strains of bacteria. This resistance to antibiotics is caused by specific genes that increase the number of these identified genes every day. This study aims to find the frequency of three coding genes related to p fimbriae, namely papA, papC, and papG, from E. coli strains extracted from patients with urinary tract infections. Also, in this research, by conducting tests related to the detection of the antimicrobial resistance of the extracted strains and using statistical analysis, an attempt has been made to find a significant relationship between the presence or absence of a gene and resistance to antibacterials. At first, 110 urine samples were collected from patients with UTI in the Dhi Qar province of Iraq. In this research, bacterial culture methods in McConkey agar and advanced biochemical tests were used for primary confirmation of E. coli contamination, and Vitek2 and API E20 systems were used for secondary confirmation of bacterial contamination in suspected samples. Finally, the result of these tests was that all 110 samples were infected with E. coli. Then, samples resistant to the antibiotics Ampicillin, Tetracycline, Ciprofloxacin, Nitrofurantoin, and Cotrimoxazole, respectively, were detected by culturing in MuellerHinton agar medium and disc diffusion using the CLSI 2021 protocol. 36.36, 24.54, 29.09, 2.72, and 20% of the samples were resistant to these antibiotics, respectively. PCR was used to amplify gene fragments, and agarose gel electrophoresis was used to determine the presence of genes. The result was that the percentages of papG, papC, and papA genes were 61.81, 38.18, and 28.18, respectively. Finally, by performing a chisquare test in SPSS software, it was found that there is a significant relationship between the presence or absence of papA and papC genes with ampicillin and a significant relationship between papG and cotrimoxazole. These findings and the findings of other researchers can help us choose the right treatment and design new treatments by determining the antibiotic resistance factor

Editorial: Preventative strategies to stop the spread of antibiotic resistance

Editorial: Preventative strategies to stop the spread of antibiotic resistance

Unveiling Rare Pathogens and Antibiotic Resistance in Tanzanian Cholera Outbreak Waters.

The emergence of antibiotic resistance is a global health concern. Therefore, understanding the mechanisms of its spread is crucial for implementing evidence-based strategies to tackle resistance in the context of the One Health approach. In developing countries where sanitation systems and access to clean and safe water are still major challenges, contamination may introduce bacteria and bacteriophages harboring antibiotic resistance genes (ARGs) into the environment. This contamination can increase the risk of exposure and community transmission of ARGs and infectious pathogens. However, there is a paucity of information on the mechanisms of bacteriophage-mediated spread of ARGs and patterns through the environment. Here, we deploy Droplet Digital PCR (ddPCR) and metagenomics approaches to analyze the abundance of ARGs and bacterial pathogens disseminated through clean and wastewater systems. We detected a relatively less-studied and rare human zoonotic pathogen, Vibrio metschnikovii, known to spread through fecal--oral contamination, similarly to V. cholerae. Several antibiotic resistance genes were identified in both bacterial and bacteriophage fractions from water sources. Using metagenomics, we detected several resistance genes related to tetracyclines and beta-lactams in all the samples. Environmental samples from outlet wastewater had a high diversity of ARGs and contained high levels of blaOXA-48. Other identified resistance profiles included tetA, tetM, and blaCTX-M9. Specifically, we demonstrated that blaCTX-M1 is enriched in the bacteriophage fraction from wastewater. In general, however, the bacterial community has a significantly higher abundance of resistance genes compared to the bacteriophage population. In conclusion, the study highlights the need to implement environmental monitoring of clean and wastewater to inform the risk of infectious disease outbreaks and the spread of antibiotic resistance in the context of One Health.

Metagenomic investigation reveals bacteriophage-mediated horizontal transfer of antibiotic resistance genes in microbial communities of an organic agricultural ecosystem.

Agricultural microbiomes are major reservoirs of antibiotic resistance genes (ARGs), posing continuous risks to human health. To understand the role of bacteriophages as vehicles for the horizontal transfer of ARGs in the agricultural microbiome, we investigated the diversity of bacterial and viral microbiota from fecal and environmental samples on an organic farm. The profiles of the microbiome indicated the highest abundance of Bacteroidetes, Firmicutes, and Proteobacteria phyla in animal feces, with varying Actinobacteria and Spirochaetes abundance across farm animals. The most predominant composition in environmental samples was the phylum Proteobacteria. Compared to the microbiome profiles, the trends in virome indicated much broader diversity with more specific signatures between the fecal and environmental samples. Overall, viruses belonging to the order Caudovirales were the most prevalent across the agricultural samples. Additionally, the similarities within and between fecal and environmental components of the agricultural environment based on ARG-associated bacteria alone were much lower than those of total microbiome composition. However, there were significant similarities in the profiles of ARG-associated viruses across the fecal and environmental components. Moreover, the predictive models of phage-bacterial interactions on bipartite ARG transfer networks indicated that phages belonging to the order Caudovirales, particularly in the Siphoviridae family, contained diverse ARG types in different samples. Their interaction with various bacterial hosts further implied the important role of bacteriophages in ARG transmission across bacterial populations. Our findings provided a novel insight into the potential mechanisms of phage-mediated ARG transmission and their correlation with resistome evolution in natural agricultural environments. IMPORTANCE Antibiotic resistance has become a serious health concern worldwide. The potential impact of viruses, bacteriophages in particular, on spreading antibiotic resistance genes is still controversial due to the complexity of bacteriophage-bacterial interactions within diverse environments. In this study, we determined the microbiome profiles and the potential antibiotic resistance gene (ARG) transfer between bacterial and viral populations in different agricultural samples using a high-resolution analysis of the metagenomes. The results of this study provide compelling genetic evidence for ARG transfer through bacteriophage-bacteria interactions, revealing the inherent risks associated with bacteriophage-mediated ARG transfer across the agricultural microbiome.

The influence of combined treatment of municipal wastewater and landfill leachate on the spread of antibiotic resistance in the environment – A preliminary case study

Environmentally-friendly management of landfill leachate (LL) poses a challenge, and LL is usually co-treated with municipal wastewater in wastewater treatment plants (WWTPs). The extent to which the co-treatment of LL and municipal wastewater influences the spread of antibiotic resistance (AR) in the environment has not been examined to date. Two WWTPs with similar wastewater composition and technology were studied. Landfill leachate was co-treated with wastewater in one of the studied WWTPs. Landfill leachate, untreated and treated wastewater from both WWTPs, and river water sampled upstream and downstream from the wastewater discharge point were analyzed. Physicochemical parameters, microbial diversity, and antibiotic resistance genes (ARGs) abundance were investigated to determine the impact of LL co-treatment on chemical and microbiological contamination in the environment. Landfill leachate increased pollutant concentrations in untreated wastewater and river water. Cotreatment of LL and wastewater could affect the abundance and diversity of microbial communities and the interactions between microbial species. Co-treatment also decreased the stability of microbial co-occurrence networks in the examined samples. The mexF gene was identified as a potential marker of environmental pollution with LL. This is the first study to explore the impact of LL on the occurrence of AR determinants in wastewater and rivers receiving effluents.

Microbial community and gene dynamics response to high concentrations of gadolinium and sulfamethoxazole in biological nitrogen removal system

The impact of high antibiotic and heavy metal pollution levels on biological nitrogen removal in wastewater treatment plants (WWTPs) remains poorly understood, posing a global concern regarding the issue spread of antibiotic resistance induced by these contaminants. Herein, we investigated the effects of gadolinium (Gd) and sulfamethoxazole (SMX), commonly found in medical wastewater, on biological nitrogen removal systems and microbial characteristics, and the fate of antibiotic resistance genes (ARGs), metal resistance genes (MRGs), and mobile genetic elements (MGEs). Our findings indicated that high SMX and Gd(III) concentrations adversely affected nitrification and denitrification, with Gd(III) exerting a strong inhibitory effect on microbial activity. Metagenomic analysis revealed that high SMX and Gd(III) concentrations could reduce microbial diversity, with Thauera and Pseudomonas emerging as dominant genera across all samples. While the relative abundance of most ARGs decreased under single Gd(III) stress, MRGs increased, and nitrification functional genes were inhibited. Conversely, combined SMX and Gd(III) pollution increased the relative abundance of intl1. Correlation analysis revealed that most genera could host ARGs and MRGs, indicating co-selection and competition between these resistance genes. However, most denitrifying functional genes exhibited a positive correlation with MRGs. Overall, our study provides novel insights into the impact of high concentrations of antibiotics and heavy metal pollution in WWTPs, and laying the groundwork for the spread and proliferation of resistance genes under combined SMX and Gd pollution.

Antimicrobial efficacy of Mentha piperata-derived biogenic zinc oxide nanoparticles against UTI-resistant pathogens

Misuse of antibiotics leads to the worldwide spread of antibiotic resistance, which motivates scientists to create new antibiotics. The recurring UTI due to antibiotics-resistant microorganism’s challenges scientists globally. The biogenic nanoparticles have the potential to meet the escalating requirements of novel antimicrobial agents. The green synthesis of nanoparticles (NPs) gained more attention due to their reliable applications against resistant microbes. The current study evaluates the biogenic ZnO NPs of Mentha piperata extract against resistant pathogens of urinary tract infections by agar well diffusion assay. The biogenic ZnO NPs revealed comparatively maximum inhibition in comparison to synthetic antibiotics against two bacterial strains (Proteus mirabilis, Pseudomonas aeruginosa) and a fungal strain (Candida albicans).The synthesized biogenic ZnO NPs alone revealed maximum activities than the combination of plant extract (PE) and ZnO NPs, and PE alone. The physiochemical features of ZnO NPs characterized through UV–Vis spectroscopy, FTIR, XRD, SEM, and EDX. The UV–Vis spectroscopy revealed 281.85 nm wavelengths; the XRD pattern revealed the crystalline structure of ZnO NPs. The FTIR analysis revealed the presence of carboxylic and nitro groups, which could be attributed to plant extract. SEM analysis revealed spherical hollow symmetry due to electrostatic forces. The analysis via EDX confirmed the presence of Zn and oxygen in the sample. The physiochemical features of synthesized ZnO NPs provide pivotal information such as quality and effectiveness. The current study revealed excellent dose-dependent antimicrobial activity against the pathogenic isolates from UTI-resistant patients. The higher concentration of ZnONPs interacts with the cell membrane which triggers oxidative burst. They may bind with the enzymes and proteins and brings epigenetic alteration which leads to membrane disruption or cell death.

Commensal Fitness Advantage May Contribute to the Global Dissemination of Multidrug-Resistant Lineages of Bacteria-The Case of Uropathogenic E. coli.

It is widely accepted that favorable fitness in commensal colonization is one of the prime facilitators of clonal dissemination in bacteria. The question arises as to what kind of fitness advantage may be wielded by uropathogenic strains of the two predominant fluoroquinolone- and multidrug-resistant clonal groups of E. coli-ST131-H30 and ST1193, which has permitted their unprecedented pandemic-like global expansion in the last few decades. The colonization-associated genes' content, carriage of low-cost plasmids, and integrons with weak promoters could certainly contribute to the fitness of the pandemic groups, although those genetic factors are common among other clonal groups as well. Also, ST131-H30 and ST1193 strains harbor fluoroquinolone-resistance conferring mutations targeting serine residues in DNA gyrase (GyrA-S83) and topoisomerase IV (ParC-S80) that, in those clonal backgrounds, might result in a commensal fitness benefit, i.e., beyond the antibiotic resistance per se. This fitness gain might have contributed not only to the widespread dissemination of these major clones in the healthcare setting but also to their long-term colonization of healthy individuals and, thus, circulation in the community, even in a low or no fluoroquinolone use environment. This evolutionary shift affecting commensal E. coli, initiated by mutations co-favorable in both antibiotics-treated patients and healthy individuals warrants more in-depth studies to monitor further changes in the epidemiological situation and develop effective measures to reduce the antibiotic resistance spread.

Impact of corrosion inhibitors on antibiotic resistance, metal resistance, and microbial communities in drinking water.

Corrosion inhibitors, including zinc orthophosphate, sodium orthophosphate, and sodium silicate, are commonly used to prevent the corrosion of drinking water infrastructure. Metals such as zinc are known stressors for antibiotic resistance selection, and phosphates can increase microbial growth in drinking water distribution systems (DWDS). Yet, the influence of corrosion inhibitor type on antimicrobial resistance in DWDS is unknown. Here, we show that sodium silicates can decrease antibiotic resistant bacteria (ARB) and antibiotic-resistance genes (ARGs), while zinc orthophosphate increases ARB and ARGs in source water microbial communities. Based on controlled bench-scale studies, zinc orthophosphate addition significantly increased the abundance of ARB resistant to ciprofloxacin, sulfonamides, trimethoprim, and vancomycin, as well as the genes sul1, qacEΔ1, an indication of resistance to quaternary ammonium compounds, and the integron-integrase gene intI1. In contrast, sodium silicate dosage at 10 mg/L resulted in decreased bacterial growth and antibiotic resistance selection compared to the other corrosion inhibitor additions. Source water collected from the drinking water treatment plant intake pipe resulted in less significant changes in ARB and ARG abundance due to corrosion inhibitor addition compared to source water collected from the pier at the recreational beach. In tandem with the antibiotic resistance shifts, significant microbial community composition changes also occurred. Overall, the corrosion inhibitor sodium silicate resulted in the least selection for antibiotic resistance, which suggests it is the preferred corrosion inhibitor option for minimizing antibiotic resistance proliferation in DWDS. However, the selection of an appropriate corrosion inhibitor must also be appropriate for the water chemistry of the system (e.g., pH, alkalinity) to minimize metal leaching first and foremost and to adhere to the lead and copper rule. IMPORTANCE Antibiotic resistance is a growing public health concern across the globe and was recently labeled the silent pandemic. Scientists aim to identify the source of antibiotic resistance and control points to mitigate the spread of antibiotic resistance. Drinking water is a direct exposure route to humans and contains antibiotic-resistant bacteria and associated resistance genes. Corrosion inhibitors are added to prevent metallic pipes in distribution systems from corroding, and the type of corrosion inhibitor selected could also have implications on antibiotic resistance. Indeed, we found that sodium silicate can minimize selection of antibiotic resistance while phosphate-based corrosion inhibitors can promote antibiotic resistance. These findings indicate that sodium silicate is a preferred corrosion inhibitor choice for mitigation of antibiotic resistance.

Potential of waterbodies as a reservoir of Escherichia coli pathogens and the spread of antibiotic resistance in the Indonesian aquatic environment

Abstract River contamination remains a significant public health problem worldwide, including in Indonesia. In the community, rivers are water resources for many purposes. However, indiscriminate use of antibiotics in the veterinary and medical sectors, the community habit of throwing waste into the river, the inadequate removal of human medicine compounds in WWTP, and poor industrial waste management will induce the spread of pathogenic bacteria and antibiotic resistance between the environment and humans/animals. This review aims to analyse the various factors that influence the emergence of pathogenic Escherichia coli and antimicrobial resistance bacteria (ARB) in the aquatic environment, especially in Indonesia. In conclusion, pathogenic E. coli can adjust its physiological or metabolic conditions to survive in aquatic environments and was found resistant to antibiotics. Meanwhile, this study also describes the potency of the aquatic environment in Indonesia as a vector for the spread of pathogenic E. coli and the growth of ARBs, factors involved in the evolution and spread of antibiotic resistance in aquatic environments, and possible ways to curtail microbial risk to public health and the emergence and spread of antimicrobial resistance in the aquatic environment in Indonesia.

Microbiota and its antibiotic resistance profile in avocado Guatemalan fruits (Persea nubigena var. guatemalensis) sold at retail markets of Ibarra city, northern Ecuador.

Avocados are typically sold in unsanitary conditions at the retail markets in Ecuador, which can raise the risk of microbial contamination. These microorganisms could exhibit multi-antibiotic resistance (MAR), being a serious threat concern to human health. In this study, we aimed to evaluate the microbiota and its antibiotic resistance profile in avocado Guatemalan fruits (Persea nubigena var. guatemalensis), at ripe stage: immature, firm light green (ready to eat in 4 days), peel (AFPE) and pulp (AFPU), and mature intense green (ready to eat) peel (AMPE) and pulp (AMPU), to gain baseline information on the prevalence of MAR bacteria. Culture-independent (16S rRNA metagenomics) and culture-dependent approach (to detect specific indicator microorganisms) were used. Moreover, antibiotic susceptibility of selected target indicator bacteria was assessed providing information about the antibiotic resistance (AR) among the groups. Based on 16S rRNA gene metagenomic analysis, over 99.78% of reads were classified as bacteria in all samples. Shannon diversity index varies from 1.22 to 2.22, with the highest bacterial population assigned to AFPE samples (1327 species). The highest microbial counts of indicator Staphylococcus spp. (STAPHY), Enterobacter spp. (ENT), and Listeria spp. (LIST), were detected in AMPE samples. Thirty percent of the selected STAPHYs, and 20.91% of Enterobacter (ENT) clones were resistant to various classes of antibiotics. The MAR index varies between 0.25 to 0.88 and was clone-, and fruit ripe stage-dependent. The results indicated that ready to eat avocados contained detectable levels of MAR bacteria, including methicillin resistant (MR)-STAPHY, which may act as a potential vector for the spread of antibiotic resistance. To achieve the increase of the production and marketing of Fuerte cultivar in Ecuador, it is vitally important to consider valuable strategies to protect the fruits at the early ripe stage in future. Thus, it is crucial to set up efficient control measures and develop coordinated strategies to guarantee the microbiological quality of the food.

Probiotics: an innovative approach to enhancing aquaculture productivity

Probiotics refer to live beneficial microorganisms introduced into the digestive system via food or water, contributing to overall well-being by promoting a balanced internal microbial environment. These probiotic microorganisms produce a variety of substances, including bacteriocins, siderophores, lysozymes, proteases, and hydrogen peroxide, which effectively inhibit the growth of harmful pathogens. Furthermore, these beneficial bacteria generate a diverse set of enzymes, including amylase enzymes produced by Aeromonas spp., Bacillus subtilis, Bacteroidaceae, Clostridium spp., Lactobacillus plantarum, and Staphylococcus sp., as well as protease and cellulase enzymes produced by B. subtilis, L. plantarum, and Staphylococcus sp. In aquaculture, probiotics have several advantages and play a crucial role in improving fish growth rates, disease resistance, immunity, maintaining health, intestinal epithelial integrity, supporting gut microbiota, and enhancing water quality. Furthermore, the practical application of probiotics in fish diets can reduce the negative impact of antibiotics. The incorporation of these supplements into fish feeds would contribute to improving their productivity and efficient feeds utilization, thereby increasing fish production and safeguarding human health. This article provides an overview of the use of probiotic preparations in aquaculture. It presents information about the composition of the innate microflora in fish, as well as historical facts regarding the development of probiotics in aquaculture. The data analysis indicates that probiotics are effective and environmentally friendly, making them suitable for the entire aquaculture system, including primary and supplementary feeding, as well as water purification. They have a positive impact on the health of aquatic organisms and consumers. Additionally, the article discusses the appropriateness of probiotic use in aquaculture for dynamic and environmentally safe fish farming development, aiming to reduce the spread of antibiotic and chemical resistance and address disease treatment and prevention in fish farms.