Horizontal Gene Transfer Research Articles

Decoding the enigma: unveiling the transmission characteristics of waterfowl-associated blaNDM-5-positive Escherichia coli in select regions of China

Escherichia coli (E. coli) serves as a critical indicator microorganism for assessing the prevalence and dissemination of antibiotic resistance, notably harboring various antibiotic-resistant genes (ARGs). Among these, the emergence of the blaNDM gene represents a significant threat to public health, especially since carbapenem antibiotics are vital for treating severe infections caused by Gram-negative bacteria. This study aimed to characterize the antibiotic resistance features of blaNDM-5-positive E. coli strains isolated from waterfowl in several regions of China and elucidate the dissemination patterns of the blaNDM-5 gene. We successfully isolated 103 blaNDM-5-positive E. coli strains from 431 intestinal fecal samples obtained from waterfowl across five provincial-level units in China, with all strains exhibiting multidrug resistance (MDR). Notably, the blaNDM-5 gene was identified on plasmids, which facilitate efficient and stable horizontal gene transfer (HGT). Our adaptability assays indicated that while the blaNDM-5-positive plasmid imposed a fitness cost on the host bacteria, the NDM-5 protein was successfully induced and purified, exhibiting significant enzymatic activity. One strain, designated DY51, exhibited a minimum inhibitory concentration (MIC) for imipenem of 4 mg/L, which escalated to 512 mg/L following exposure to increasing imipenem doses. This altered strain demonstrated stable resistance to imipenem alongside improved adaptability, correlating with elevated relative expression levels of the blaNDM-5 and overexpression of efflux pumps. Collectively, this study highlights the horizontal dissemination of the blaNDM-5 plasmid among E. coli strains, confirms the associated fitness costs, and provides insights into the mechanisms underlying the stable increase in antibiotic resistance to imipenem. These findings offer a theoretical framework for understanding the dissemination dynamics of blaNDM-5 in E. coli, which is essential for developing effective strategies to combat carbapenem antibiotic resistance.

Environmental Pollution and Extraction Methods of Extracellular Antibiotic Resistance Genes in Water

Antibiotics are widely used to treat diseases such as bacterial infections. However, the abuse of antibiotics has led to the spread of antibiotic resistant bacteria and intracellular and extracellular antibiotic resistance genes, making China one of the countries with the highest incidence of antibiotic resistance and thus threatening public health. Extracellular antibiotic resistance genes, as one of the novel environmental pollutants, could exist in water for a long time and could be transmitted between different bacteria through horizontal gene transfer, resulting in the spread of antibiotic resistance. At present, due to the limitation of enrichment and recovery methods, the in-depth studies of extracellular antibiotic resistance genes in water have been rarely reported. Thus, it is impossible to carry out effective supervision and risk assessments. Based on literature analysis and investigation, the pollution sources, current situations, and characteristics of extracellular antibiotic resistance genes in water are expounded. Meanwhile, the advantages and disadvantages of their enrichment and recovery methods are compared and analyzed and the enrichment and recovery methods are verified and discussed through practical cases. These provide theoretical reference for studies such as examining extracellular antibiotic resistance genes in water on their transmission and provide a technical basis for antibiotic resistance control and health risk assessments of extracellular antibiotic resistance genes.

Gene acquisition by giant transposons primes eukaryotes for rapid evolution via horizontal gene transfer.

Horizontal gene transfer (HGT) disseminates genetic information between species and is a powerful mechanism of adaptation. Yet, we know little about its underlying drivers in eukaryotes. Giant Starship transposons have been implicated as agents of fungal HGT, providing an unprecedented opportunity to reveal the evolutionary parameters behind this process. Here, we characterize the ssf gene cluster, which contributes to formaldehyde resistance, and use it to demonstrate how mobile element evolution shapes fungal adaptation. We found that ssf clusters have been acquired by various distantly related Starships, which each exhibit multiple instances of horizontal transfer across fungal species (at least nine events, including between different taxonomic orders). Many ssf clusters have subsequently integrated into their host's genome, illustrating how Starships shape the evolutionary trajectory of fungal hosts beyond any single transfer. Our results demonstrate the key role Starships play in mediating rapid and repeated adaptation via HGT, elevating the importance of mobile element evolution in eukaryotic biology.

How can statistical models improve the accuracy of phylogenetic tree reconstruction?

When building the phylogenetic tree, current methods for calculating phylogenetic trees often lack the desired level of accuracy. This research paper explores the role of statistical models in enhancing the precision of phylogenetic tree reconstruction. The phylogenetic tree plays an important role in phylogenetic analysis and evolutionary biology. An accurate phylogenetic tree underpins our understanding of the major transitions in evolution, such as the emergence of new body plans or metabolism. Recent advancements in statistical modeling have more elaborate improvements than traditional methods. For example, Bayesian inference and maximum likelihood estimation provide frameworks for evaluating phylogenetic relationships by incorporating probability distributions and likelihood functions. These models account for the inherent uncertainties and variations in genetic data, leading to more accurate tree constructions. Moreover, using statistical models allows for the incorporation of complex evolutionary processes such as variable rates of evolution across lineages, horizontal gene transfer, and hybridization events. Techniques like Markov Chain Monte Carlo (MCMC) and bootstrap methods enhance the reliability of the inferred phylogenies by providing measures of confidence for the estimated relationships. Using these advanced statistical approaches, researchers can gain more accurate and reliable phylogenetic trees. Through a comprehensive review of current methodologies and case studies, this study aims to highlight statistical models' significant impact on evolutionary biology and the broader field of phylogenetics analysis and evolutionary biology.

Gene transfer between fungal species triggers repeated coffee wilt disease outbreaks.

Two outbreaks of coffee wilt disease have devastated African coffee production. A PLOS Biology study suggests that horizontal gene transfer via large Starship transposons between 2 fungal species played a key role in the repeated emergence of the disease.

Low dose Adenoviral Vammin gene transfer induces myocardial angiogenesis and increases left ventricular ejection fraction in ischemic porcine heart

This preliminary study investigated if VEGFR-2 selective adenoviral Vammin (AdVammin) gene therapy could induce angiogenesis and increase perfusion in the healthy porcine myocardium. Also, we determined using a clinically relevant large animal model if AdVammin gene therapy could improve the function of a chronically ischemic heart. Low doses of AdVammin (dose range 2 × 109–2 × 1010 vp) gene transfers were performed into the porcine myocardium using an endovascular injection catheter. AdCMV was used as a control. The porcine model of chronic myocardial ischemia was used in the ischemic studies. The AdVammin enlarged the mean capillary area and stimulated pericyte coverage in the target area 6 days after the gene transfers. Using positron emission tomography 15O-radiowater imaging, we demonstrated that AdVammin gene therapy increased perfusion in healthy myocardium at rest. AdVammin treatment also increased ejection fraction at stress in the ischemic heart, as detected using left ventricular cine angiography. In addition, we demonstrated successful in vivo imaging of enhanced angiogenesis using [68Ga]NODAGA-RGD peptide. However, AdVammin also increased tissue permeability and was associated with significant pericardial fluid accumulation, limiting AdVammin’s therapeutic potential and emphasizing the importance of correct dosage.

Pore-forming toxin-like proteins in the anti-parasitoid immune response of Drosophila.

Species of the ananassae subgroup of Drosophilidae are highly resistant to parasitoid wasp infections. We have previously shown that the genes encoding Cytolethal Distending Toxin B (CdtB) and the Apoptosis Inducing Protein of 56 kDa (AIP56) were horizontally transferred to these fly species from prokaryotes and are now instrumental in the anti-parasitoid immune defense of Drosophila ananassae. Here we describe a new family of genes, which encode proteins with Hemolysin E domains, heretofore only identified in prokaryotes. Hemolysin E proteins are pore-forming toxins, important virulence factors of bacteria. Bioinformatical, transcriptional and protein expressional studies were used. The hemolysin E-like genes have a scattered distribution among the genomes of species belonging to several different monophyletic lineages in the family Drosophilidae. We detected structural homology with the bacterial Hemolysin E toxins and showed that the origin of the D. ananassae hemolysin E-like genes (hl1-38) is consistent with prokaryotic horizontal gene transfer. These genes encode humoral factors, secreted into the hemolymph by the fat body and hemocytes. Their expression is induced solely by parasitoid infection and the proteins bind to the developing parasitoids. Hemolysin E-like proteins acquired by horizontal gene transfer and expressed by the primary immune organs may contribute to the elimination of parasitoids, as novel humoral factors in Drosophila innate immunity.

Local Electric Field-Incorporated In-Situ Copper Ions Eliminating Pathogens and Antibiotic Resistance Genes in Drinking Water

Background/Objectives: Pathogen inactivation and harmful gene destruction from water just before drinking is the last line of defense to protect people from waterborne diseases. However, commonly used disinfection methods, such as chlorination, ultraviolet irradiation, and membrane filtration, experience several challenges such as continuous chemical dosing, the spread of antibiotic resistance genes (ARGs), and intensive energy consumption. Methods: Here, we perform a simultaneous elimination of pathogens and ARGs in drinking water using local electric fields and in-situ generated trace copper ions (LEF-Cu) without external chemical dosing. A 100-μm thin copper wire placed in the center of a household water pipe can generate local electric fields and trace copper ions near its surface after an external low voltage is applied. Results: The local electric field rapidly damages the outer structure of microorganisms through electroporation, and the trace copper ions can effectively permeate the electroporated microorganisms, successfully damaging their nucleic acids. The LEF-Cu disinfection system achieved complete inactivation (>6 log removal) of Escherichia coli O157:H7, Pseudomonas aeruginosa PAO1, and bacteriophage MS2 in drinking water at 2 V for 2 min, with low energy consumption (10−2 kWh/m3). Meanwhile, the system effectively damages both intracellular (0.54~0.64 log) and extracellular (0.5~1.09 log) ARGs and blocks horizontal gene transfer. Conclusions: LEF-Cu disinfection holds promise for preventing horizontal gene transfer and providing safe drinking water for household applications.

A chromosomal mutation is superior to a plasmid-encoded mutation for plasmid fitness cost compensation.

Plasmids are important vectors of horizontal gene transfer in microbial communities but can impose a burden on the bacteria that carry them. Such plasmid fitness costs are thought to arise principally from conflicts between chromosomal- and plasmid-encoded molecular machineries, and thus can be ameliorated by compensatory mutations (CMs) that reduce or resolve the underlying causes. CMs can arise on plasmids (i.e., plaCM) or on chromosomes (i.e., chrCM), with contrasting predicted effects upon plasmid success and subsequent gene transfer because plaCM can also reduce fitness costs in plasmid recipients, whereas chrCM can potentially ameliorate multiple distinct plasmids. Here, we develop theory and a novel experimental system to directly compare the ecological effects of plaCM and chrCM that arose during evolution experiments between Pseudomonas fluorescens SBW25 and its sympatric mercury resistance megaplasmid pQBR57. We show that while plaCM was predicted to succeed under a broader range of parameters in mathematical models, chrCM dominated in our experiments, including conditions with numerous recipients, due to a more efficacious mechanism of compensation, and advantages arising from transmission of costly plasmids to competitors (plasmid "weaponisation"). We show analytically the presence of a mixed Rock-Paper-Scissors (RPS) regime for CMs, driven by trade-offs with horizontal transmission, that offers one possible explanation for the observed failure of plaCM to dominate even in competition against an uncompensated plasmid. Our results reveal broader implications of plasmid-bacterial evolution for plasmid ecology, demonstrating the importance of specific compensatory mutations for resistance gene spread. One consequence of the superiority of chrCM over plaCM is the likely emergence in microbial communities of compensated bacteria that can act as "hubs" for plasmid accumulation and dissemination.

Origins

Abstract Scientific origins are information sources that transmit encoded information signals to receivers. Originary sciences identify information preserving receivers and decode the signals to infer their origins. Paradigmatic cases of scientific origination such as the Big Bang, the origins of species, horizontal gene transfer, the origin of the Polynesian potato, and ideational origins in the history of ideas are analyzed to discover what is common to them ontologically and epistemically. Some causes are not origins. Origination supervenes on causation, but has different properties. The unique properties of origins that causes do not share shield theories of origination from the kind of counterexamples and counterintuitive results that challenge comparable theories of causation. The epistemology of origination may serve as a basis for founding a novel epistemic and methodological division of the sciences into originary historical sciences and causal theoretical sciences.

Horizontal transfers between fungal Fusarium species contributed to successive outbreaks of coffee wilt disease.

Outbreaks of fungal diseases have devastated plants and animals throughout history. Over the past century, the repeated emergence of coffee wilt disease caused by the fungal pathogen Fusarium xylarioides severely impacted coffee production across sub-Saharan Africa. To improve the disease management of such pathogens, it is crucial to understand their genetic structure and evolutionary potential. We compared the genomes of 13 historic strains spanning 6 decades and multiple disease outbreaks to investigate population structure and host specialisation. We found that F. xylarioides comprised at least 4 distinct lineages: 1 host-specific to Coffea arabica, 1 to C. canephora var. robusta, and 2 historic lineages isolated from various Coffea species. The presence/absence of large genomic regions across populations, the higher genetic similarities of these regions between species than expected based on genome-wide divergence and their locations in different loci in genomes across populations showed that horizontal transfers of effector genes from members of the F. oxysporum species complex contributed to host specificity. Multiple transfers into F. xylarioides populations matched different parts of the F. oxysporum mobile pathogenicity chromosome and were enriched in effector genes and transposons. Effector genes in this region and other carbohydrate-active enzymes important in the breakdown of plant cell walls were shown by transcriptomics to be highly expressed during infection of C. arabica by the fungal arabica strains. Widespread sharing of specific transposons between F. xylarioides and F. oxysporum, and the correspondence of a putative horizontally transferred regions to a Starship (large mobile element involved in horizontal gene transfers in fungi), reinforce the inference of horizontal transfers and suggest that mobile elements were involved. Our results support the hypothesis that horizontal gene transfers contributed to the repeated emergence of coffee wilt disease.

Quantitative microbial risk assessment of antibiotic-resistant Salmonella enterica contaminating hydroponic leafy vegetables

Hydroponics plays an important role in addressing food security concerns, particularly in countries aiming to increase food self-sufficiency. However, it is vulnerable to microbial contamination, and biofilms formed in hydroponic facilities may promote horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). Eventually, the bacteria are internalized into the edible parts of the vegetable through the roots, which can lead to human exposure to antibiotic-resistant pathogenic bacteria. Microbial risk assessment can play a pivotal role in microbial risk management; however, it has not been conducted for hydroponic systems. In this study, a quantitative microbial risk assessment of hydroponic vegetables was performed using literature values regarding the concentration of Salmonella spp. in hydroponics, efficiency of HGT, probability and rate of internalization, vegetable consumption patterns, and dose-response relationships. Furthermore, a sensitivity analysis was performed to identify the factors that had a significant impact on the infection probability per single exposure event for all Salmonella spp. by calculating Spearman's correlation coefficients. The estimated annual probability of infection per person by all Salmonella spp. was 2.04×10−1, while the estimated probability of infection from Salmonella spp. that acquired ARGs was 2.54×10−6. Our sensitivity analysis showed the correlation between the occurrence of internalization and hydroponic contamination levels, highlighting the need for increased awareness and regulatory action.

Salmonella enterica Serovar Infantis KPC-2 Producer: First Isolate Reported in Ecuador.

Antimicrobial resistance is currently considered a public health threat. Carbapenems are antimicrobials for hospital use, and Enterobacterales resistant to these β-lactams have spread alarmingly in recent years, especially those that cause health care-associated infections. The blaKPC gene is considered one of the most important genetic determinants disseminated by plasmids, promoting horizontal gene transfer. This study describes, for the first time in Ecuador, and worldwide, the presence of a blaKPC-2 gene in an isolate of Salmonella enterica serovar Infantis from a clinical sample. Through whole-genome sequencing, we characterized the genetic determinants of antimicrobial resistance in this Salmonella ST-32 strain. Our results showed the presence of several resistance genes, including blaCTX-M-65, and a conjugative plasmid Kpn-WC17-007-03 that may be responsible for the horizontal transference of these resistance mechanisms.

A Comprehensive Analysis of the Epidemiological and Genomic Characteristics of Global Serratia marcescens

BackgroundSerratia marcescens outbreaks present significant challenges in clinical treatment, necessitating a deeper understanding of its epidemiological and genomic traits. ObjectiveTo analyze the epidemiological and genomic characteristics of S. marcescens at a global scale. MethodsHigh-quality genomes of S. marcescens were retrieved from NCBI and annotated using Prodigal. Antibiotic resistance genes (ARGs) were identified via Blastn, sequence types (STs) were determined with a proprietary tool, and phylogenetic analysis was conducted to explore evolutionary relationships. ResultsThe study analyzed genomes from 33 countries, with major contributions from the USA (27.8%), UK (15.3%), Italy (14.7%), and Japan (10.7%). Human clinical samples accounted for 73.5% of the isolates, primarily from blood (44.8%) and sputum (19.3%). Eleven ARGs were identified, with sde being the most prevalent. Carbapenemase genes included blaSME, blaKPC, and blaNDM-1, though co-occurrence in individual strains was absent. Novel ARGs, including armA, rmtC, and fosA7.2, were reported. Among 855 genomes with identified STs, ST366, ST367, ST365, and ST423 were most common. Phylogenetic analysis highlighted significant genetic diversity and distinct evolutionary lineages. ConclusionTemporal analysis showed a genome peak in 2019, underscoring the global prevalence and adaptability of S. marcescens. The distribution of ARGs across diverse STs emphasizes horizontal gene transfer as a key driver of resistance. Judicious antibiotic use is essential to mitigate further resistance.

Niche-specific evolution and gene exchange of Salmonella in retail pork and chicken

Salmonella exhibits extensive genetic diversity, facilitated by horizontal gene transfer occurring within and between species, playing a pivotal role in this diversification. Nevertheless, most studies focus on clinical and farm animal isolates, and research on the pangenome dynamics of Salmonella isolates from retail stage of the animal food supply chain is limited. Here, we investigated the genomes of 950 Salmonella isolates recovered from retail chicken and pork meats in seven provinces and one municipality of China in 2018. We observed a strong correlation between Salmonella sublineage diversity and the accessory genome with meat type, revealing reduced diversity associated with increased resistance. Importantly, genes associated with antibiotic, biocide, and heavy metal resistance were unevenly distributed in Salmonella from retail chicken and pork. Pork Salmonella isolates showed a higher prevalence of copper and silver resistance genes, while chicken Salmonella isolates displayed a significant predominance of genetic determinants associated with cephalosporin and ciprofloxacin resistance. Moreover, co-occurrence patterns of resistance determinants and their interaction with mobile genetic elements also correlated with meat type. In summary, our findings shed light on how Salmonella achieves their ecological niche success driven by evolution and gene changes in the retail stage of the animal food supply chain.

Deciphering basic and key traits of bio-pollutants in a long-term reclaimed water headwater urban stream.

Reclaimed water has been recognized as a stable water resource for ecological replenishment in riverine environment. However, information about the bio-pollutants spatial and temporal distributions and the associated risk in this environment remains insufficient. Herein, the bio-pollutant profile in a long-term reclaimed water headwater urban stream, including antibiotic resistance genes (ARGs), mobile genetic elements and pathogens, were revealed by metagenomics. Notably, the temporal variation in bio-pollutant levels exceeded spatial fluctuations, possibly due to the varied rainfall intensity. Specially, multidrug resistance genes and Acinetobacter baumannii (A. baumannii) were the dominant ARGs and pathogens, respectively, exhibiting higher abundance in the dry season, especially in the downstream of the receiving point, where the bio-risk also peaked. A. baumannii and Ralstonia solanacearum were found to be the main plasmids contributors inducing the horizontal gene transfer process in this stream. Overall, A. baumannii contributed over 50% bio-risk values in most samples, indicating that it was the "overlord" in this headwater urban stream. This study revealed characteristics of bio-pollutants in a typical long-term reclaimed water headwater urban stream, highlighting the superiority of A. baumannii in bio-pollutants, which should be a key consideration in the bio-pollutants surveillance for reclaimed waters.

Antibiotic resistance genes and virulence factors in the plastisphere in wastewater treatment plant effluent: Health risk quantification and driving mechanism interpretation

Microplastics (MPs) are ubiquitous in wastewater treatment plants (WWTPs) and provide a unique niche for the spread of pollutants. To date, risk assessments and driving mechanisms of pathogens, antibiotic resistance genes (ARGs), and virulence factors (VFs) in the plastisphere are still lacking. Here, the microbiota, ARGs, VFs, their potential health risks, and biologically driving mechanisms on polythene (PE), polyethylene terephthalate (PET), poly (butyleneadipate-co-terephthalate) and polylactic acid blends (PBAT/PLA), PLA MPs, and gravel in WWTP effluent were investigated. The results showed that plastisphere and gravel biofilm harbored more distinctive microorganisms, promoting the uniqueness of pathogens, ARGs, and VFs compared to WWTP effluent. The abundance of major pathogens, ARGs, and VFs in the plastisphere was 1.01–1.35 times higher than that in the effluent. The high health risk of ARGs (HRA) calculated by fully considering the abundance, clinical relevance, pathogenicity, accessibility and mobility, and the high proportion of resistance contigs with mobile genetic elements confirmed that the plastisphere posed the highest potential health risk. Candidatus Microthrix and Candidatus Promineifilum were the essential hosts of ARGs and VFs in the plastisphere and gravel biofilm, respectively. High metabolic activity such as amino acid metabolism and biosynthesis of secondary metabolites, and highly expressed key genes increased the synthesis of ARGs and VFs. The primary mechanisms driving ARG enrichment in the plastisphere were enhanced microbial metabolic activity, increased frequency of horizontal gene transfer, heightened antibiotic inactivation and efflux, and reduced cell permeability. This study provided new insights into the ARGs, VFs, and health risks of the plastisphere and emphasized the importance of strict control of wastewater discharge.

Biofeed through bioconversion process with the engineered methyl-microbium buryatense strain 5GBC1-RO1

This study presents a novel approach to mitigate methane emissions while simultaneously addressing the growing demand for sustainable animal feed through the development of an engineered methanotrophic strain, Methylomicrobium buryatense 5GB1C-RO1. Utilizing advanced genetic engineering techniques, including CRISPR/Cas9 and horizontal gene transfer, we have optimized the ribulose monophosphate (RuMP) cycle and enhanced oxidase activity in this strain. The bioconversion process is facilitated by innovative bioreactor designs, including Two-Phase Partitioning Bioreactors (TPPBs) and Inverse Membrane Bioreactors (IMBRs), which significantly improve methane solubility and mass transfer. Through metabolic flux analysis and computational modeling, we have achieved high biomass yields and efficient methane utilization. The resulting biofeed demonstrates a superior nutritional profile, with optimized macronutrient content and essential components. This integrated approach not only contributes to greenhouse gas mitigation but also offers a promising solution for sustainable animal nutrition. Our findings suggest that the 5GB1C-RO1 strain and associated bioprocesses have the potential to revolutionize both environmental protection and agricultural sustainability.

Uneven distribution of prokaryote-derived horizontal gene transfer in fungi: a lifestyle-dependent phenomenon.

This study sheds new light on the role of horizontal gene transfer (HGT) in fungi, an area that has remained relatively unexplored compared to its well-established prevalence in bacteria. By analyzing 829 fungal genomes, we identified over 20,000 genes that fungi acquired from prokaryotes, revealing the significant impact of HGT on fungal evolution. Our findings highlight that fungal lifestyle traits, such as being parasitic or saprotrophic, play a key role in determining the extent of HGT, with parasites showing the highest gene acquisition rates. We also uncovered unique patterns of HGT occurrence based on fungal morphology and reproduction. Importantly, genes with introns, which are more highly expressed, appear to play a crucial role in fungal adaptation. This research deepens our understanding of how HGT contributes to the metabolic diversity and ecological success of fungi, and it underscores the broader significance of gene transfer in shaping fungal evolution.

Antibiotic Resistance in Vibrio Bacteria Associated with Red Spotting Disease in Sea Urchin Tripneustes gratilla (Echinodermata)

The red spotting disease harms sea urchins to the extent of mass mortality in the ocean and echinocultures, accompanied by environmental damage and economic losses. The current study emphasizes the antimicrobial resistance of three isolated bacteria, closely related to Vibrio harveyi, Vibrio owensii, and Vibrio fortis, associated with red spotting in the cultured sea urchin Tripneustes gratilla. In vitro trials examined the susceptibility of these bacterial isolates to various antibiotics. In addition, using an in silico examination, we revealed the arsenal of antimicrobial resistance genes in available genomes of various pathogenic Vibrio associated with diseases in sea urchins, fish, shellfish, and corals. These two approaches enabled the discussion of the similarities and differences between aquatic pathogenic Vibrio and their antibiotic resistance. Among them, we revealed a core resistance to tetracyclines and penams by the in vitro examined strains. At the same time, the in silico study also supported this core resistance by the presence of the adeF and CRP genes in the bacterial genomes. Nevertheless, variability and specific resistance were evident at the species and strain levels in the Vibrio bacteria and genomes. The in vitro trials highlighted the diverse resistance of the Vibrio harveyi-like isolate to all examined antibiotics, while the other two isolates were found susceptible to nitrofurantoin and sulfamethoxazole. The resistance of the Vibrio harveyi-like isolate could not have been obtained in the genome of the proposed relative of Vibrio harveyi VHJR7 that lacks the oqxA and oqxB genes, which enables such a resistance. A unique sensitivity of the Vibrio fortis-like isolate to erythromycin is proposed when compared to other isolated Vibrio and Vibrio genomes that seem capable of resisting this drug. According to the results, we propose nitrofurantoin or sulfamethoxazole for treating two of the red-spotting-associated isolates (Vibrio fortis and Vibrio owensii-like), but not Vibrio harveyi-like. We assume that a shared resistance to some antibiotics by Vibrios is gained by a horizontal gene transfer while previous exposures of a bacterial strain to a specific drug may induce the development of a unique resistance. Finally, we discuss the novel knowledge on antibiotic resistance in Vibrio from the current research in light of the potential risks when using drugs for disease control in aquaculture.