Genome characterization of a multi-drug resistant Escherichia coli strain, L1PEag1, isolated from commercial cape gooseberry fruits (Physalis peruviana L.).

Introduction: Foodborne infections, which are frequently linked to bacterial contamination, are a serious concern to public health on a global scale. Whether agricultural farming practices help spread genes linked to antibiotic resistance in bacteria associated with humans or animals is a controversial question. Methods: This study applied a long-read Oxford Nanopore MinION-based sequencing to obtain the complete genome sequence of a multi-drug resistant Escherichia coli strain (L1PEag1), isolated from commercial cape gooseberry fruits (Physalis peruviana L.) in Ecuador. Using different genome analysis tools, the serotype, Multi Locus Sequence Typing (MLST), virulence genes, and antimicrobial resistance (AMR) genes of the L1PEag1 isolate were determined. Additionally, in vitro assays were performed to demonstrate functional genes. Results: The complete genome sequence of the L1PEag1 isolate was assembled into a circular chromosome of 4825.722 Kbp and one plasmid of 3.561 Kbp. The L1PEag1 isolate belongs to the B2 phylogroup, sequence type ST1170, and O1:H4 serotype based on in silico genome analysis. The genome contains 4,473 genes, 88 tRNA, 8 5S rRNA, 7 16S rRNA, and 7 23S rRNA. The average GC content is 50.58%. The specific annotation consisted of 4,439 and 3,723 genes annotated with KEEG and COG respectively, 3 intact prophage regions, 23 genomic islands (GIs), and 4 insertion sequences (ISs) of the ISAs1 and IS630 families. The L1PEag1 isolate carries 25 virulence genes, and 4 perfect and 51 strict antibiotic resistant gene (ARG) regions based on VirulenceFinder and RGI annotation. Besides, the in vitro antibiotic profile indicated resistance to kanamycin (K30), azithromycin (AZM15), clindamycin (DA2), novobiocin (NV30), amikacin (AMK30), and other antibiotics. The L1PEag1 isolate was predicted as a human pathogen, matching 464 protein families (0.934 likelihood). Conclusion: Our work emphasizes the necessity of monitoring environmental antibiotic resistance, particularly in commercial settings to contribute to develop early mitigation techniques for dealing with resistance diffusion.

Genetics of resistance to trimethoprim in cotrimoxazole resistant uropathogenic Escherichia coli: integrons, transposons, and single gene cassettes.

Cotrimoxazole, the combined formulation of sulfamethoxazole and trimethoprim, is one of the treatments of choice for several infectious diseases, particularly urinary tract infections. Both components of cotrimoxazole are synthetic antimicrobial drugs, and their combination was introduced into medical therapeutics about half a century ago. In Gram-negative bacteria, resistance to cotrimoxazole is widespread, being based on the acquisition of genes from the auxiliary genome that confer resistance to each of its antibacterial components. Starting from previous knowledge on the genotype of resistance to sulfamethoxazole in a collection of cotrimoxazole resistant uropathogenic Escherichia coli strains, this work focused on the identification of the genetic bases of the trimethoprim resistance of these same strains. Molecular techniques employed included PCR and Sanger sequencing of specific amplicons, conjugation experiments and NGS sequencing of the transferred plasmids. Mobile genetic elements conferring the trimethoprim resistance phenotype were identified and included integrons, transposons and single gene cassettes. Therefore, strains exhibited several ways to jointly resist both antibiotics, implying different levels of genetic linkage between genes conferring resistance to sulfamethoxazole (sul) and trimethoprim (dfrA). Two structures were particularly interesting because they represented a highly cohesive arrangements ensuring cotrimoxazole resistance. They both carried a single gene cassette, dfrA14 or dfrA1, integrated in two different points of a conserved cluster sul2-strA-strB, carried on transferable plasmids. The results suggest that the pressure exerted by cotrimoxazole on bacteria of our environment is still promoting the evolution toward increasingly compact gene arrangements, carried by mobile genetic elements that move them in the genome and also transfer them horizontally among bacteria.

Novel human recombinant N-acetylgalactosamine-6-sulfate sulfatase produced in a glyco-engineered Escherichia coli strain.

Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disease caused by mutations in the gene encoding the lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS), resulting in the accumulation of keratan sulfate (KS) and chondroitin-6-sulfate (C6S). Previously, it was reported the production of an active human recombinant GALNS (rGALNS) in E. coli BL21(DE3). However, this recombinant enzyme was not taken up by HEK293 cells or MPS IVA skin fibroblasts. Here, we leveraged a glyco-engineered E. coli strain to produce a recombinant human GALNS bearing the eukaryotic trimannosyl core N-glycan, Man3GlcNAc2 (rGALNSoptGly). The N-glycosylated GALNS was produced at 100 mL and 1.65 L scales, purified and characterized with respect to pH stability, enzyme kinetic parameters, cell uptake, and KS clearance. The results showed that the addition of trimannosyl core N-glycans enhanced both protein stability and substrate affinity. rGALNSoptGly was capture through a mannose receptor-mediated process. This enzyme was delivered to the lysosome, where it reduced KS storage in human MPS IVA fibroblasts. This study demonstrates the potential of a glyco-engineered E. coli for producing a fully functional GALNS enzyme. It may offer an economic approach for the biosynthesis of a therapeutic glycoprotein that could prove useful for MPS IVA treatment. This strategy could be extended to other lysosomal enzymes that rely on the presence of mannose N-glycans for cell uptake.

Encapsulation of Cinnamaldehyde and Vanillin as a Strategy to Increase Their Antimicrobial Activity.

Many studies have suggested that the encapsulation of natural antimicrobials increases their antimicrobial activity. In this sense, the objective was to study the inactivation of microorganisms with encapsulated cinnamaldehyde and vanillin (E-CIN and E-VN), in comparison with the unencapsulated antimicrobials (CIN and VN) in protein beverages. Additionally, the microbial response was quantified through mathematical modeling. Cinnamaldehyde and vanillin were encapsulated using whey protein concentrate (WPC) as the encapsulating agent. The effectiveness at inactivating Escherichia coli, Listeria innocua, and Saccharomyces cerevisiae was evaluated in a protein-apple juice beverage during storage (4 °C). Encapsulation increased the effectiveness of cinnamaldehyde, reaching reductions of 1.8, 3.3, and 5.3 log CFU/mL in E. coli, L. innocua, and S. cerevisiae, respectively, while vanillin encapsulation had little effect on antimicrobial activity, reducing by 0.5, 1.4, and 1.1 log cycles, respectively. The combined treatments (E-CIN + E-VN) had an additive effect in reducing E. coli and a synergistic effect against S. cerevisiae. The Gompertz model was more versatile and better described the biphasic curves, whereas the Weibull model complemented the information regarding the spectrum of resistances within the microbial population. In conclusion, the encapsulation of cinnamaldehyde with WPC enhanced its activity. However, further studies are necessary to improve the antimicrobial activity of vanillin.

Synthesis and Superficial Modification "In Situ" of Copper Selenide (Cu2-x Se) Nanoparticles and Their Antibacterial Activity.

Copper selenide nanoparticles (Cu2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied. In addition, we present an antimicrobial study with different microorganisms such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albiacans (C. albicans). Copper selenide nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry analysis (DSC) and TEM. XRD confirmed the crystal-line structure of the nanoparticles such as cubic berzelanite with a particle size of 6 nm ± 0.5. FTIR and TGA corroborated the surface modification of copper selenide nanoparticles with gum arabic, and DSC suggested a change in the structural phase from cubic to hexagonal. TEM analysis demonstrated that the surface modification of the Cu2-x Se NPs stabilized the nanostructure of the particles, preventing changes in the morphology and particle size. The antimicrobial susceptibility analysis of copper selenide nanoparticles indicated that they have the ability to inhibit the microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans.

Influence of hydroclimatic conditions and anthropogenic activities on the water quality of a floodplain lake (Argentina) during a warm season.

Contamination of water bodies, associated with urbanization, agricultural, and industrial activities, is a serious environmental challenge, with particular concern about microbial pollution due to its public health implications. This study is aimed at evaluating the spatial and temporal variations in the microbiological and physicochemical quality of a floodplain lake used for recreational purposes, whose watershed has been disturbed by diverse anthropogenic activities. The results showed that, while the spatial variation of water quality principally depends on the basin characteristics, temporal variation of water quality depends on land uses, hydrological conditions, and climatic conditions. Rainfall and rising water level intensified the influence of land use on the water quality by increasing concentrations of Escherichia coli, thermotolerant coliforms, and organic matter and decreasing dissolved oxygen. Thus, the residents and tourists are potentially exposed to microbiological risks given that it exceeds the international standards suggested for recreational waters on some occasions. It would be advisable to improve routine bathing water monitoring and management to preserve the health of the inhabitants and limit the recreational use of the water body in the days following heavy rainfall as well as during the beginning of the increase in the hydrometric level.

Escherichia coli Strains Isolated from American Bison (Bison bison) Showed Uncommon Virulent Gene Patterns and Antimicrobial Multi-Resistance.

E. coli is considered one of the most important zoonotic pathogens worldwide. Highly virulent and antimicrobial-resistant strains of E. coli have been reported in recent years, making it essential to understand their ecological origins. In this study, we analyzed the characteristics of E. coli strains present in the natural population of American bison (Bison bison) in Mexico. We sampled 123 individuals and determined the presence of E. coli using standard bacteriological methods. The isolated strains were characterized using molecular techniques based on PCR. To evaluate the diversity of E. coli strains in this population, we analyzed 108 suggestive colonies from each fecal sample. From a total of 13,284 suggestive colonies, we isolated 33 E. coli strains that contained at least one virulence gene. The virotypes of these strains were highly varied, including strains with atypical patterns or combinations compared to classical pathotypes, such as the presence of escV, eae, bfpB, and ial genes in E. coli strain LMA-26-6-6, or stx2, eae, and ial genes in E. coli strain LMA-16-1-32. Genotype analysis of these strains revealed a previously undescribed phylogenetic group. Serotyping of all strains showed that serogroups O26 and O22 were the most abundant. Interestingly, strains belonging to these groups exhibited different patterns of virulence genes. Finally, the isolated E. coli strains demonstrated broad resistance to antimicrobials, including various beta-lactam antibiotics.

Isolation and Characterization of Escherichia coli from Brazilian Broilers.

Avian pathogenic Escherichia coli (APEC) causes colibacillosis, one of the main diseases leading to economic losses in industrial poultry farming due to high morbidity and mortality and its role in the condemnation of chicken carcasses. This study aimed to isolate and characterize APEC obtained from necropsied chickens on Brazilian poultry farms. Samples from birds already necropsied by routine inspection were collected from 100 batches of broiler chickens from six Brazilian states between August and November 2021. Three femurs were collected per batch, and characteristic E. coli colonies were isolated on MacConkey agar and characterized by qualitative PCR for minimal predictive APEC genes, antimicrobial susceptibility testing, and whole genome sequencing to identify species, serogroups, virulence genes, and resistance genes. Phenotypic resistance indices revealed significant resistance to several antibiotics from different antimicrobial classes. The isolates harbored virulence genes linked to APEC pathogenicity, including adhesion, iron acquisition, serum resistance, and toxins. Aminoglycoside resistance genes were detected in 79.36% of isolates, 74.6% had sulfonamide resistance genes, 63.49% showed ß-lactam resistance genes, and 49.2% possessed at least one tetracycline resistance gene. This study found a 58% prevalence of avian pathogenic E. coli in Brazilian poultry, with strains showing notable antimicrobial resistance to commonly used antibiotics.

Evaluation of the Humoral Response after Immunization with a Chimeric Subunit Vaccine against Shiga Toxin-Producing Escherichia coli in Pregnant Sows and Their Offspring.

Shiga toxin-producing Escherichia coli (STEC) poses a significant public health risk due to its zoonotic potential and association with severe human diseases, such as hemorrhagic colitis and hemolytic uremic syndrome. Ruminants are recognized as primary reservoirs for STEC, but swine also contribute to the epidemiology of this pathogen, highlighting the need for effective prevention strategies across species. Notably, a subgroup of STEC that produces Shiga toxin type 2e (Stx2e) causes edema disease (ED) in newborn piglets, economically affecting pig production. This study evaluates the immunogenicity of a chimeric protein-based vaccine candidate against STEC in pregnant sows and the subsequent transfer of immunity to their offspring. This vaccine candidate, which includes chimeric proteins displaying selected epitopes from the proteins Cah, OmpT, and Hes, was previously proven to be immunogenic in pregnant cows. Our analysis revealed a broad diversity of STEC serotypes within swine populations, with the cah and ompT genes being prevalent, validating them as suitable antigens for vaccine development. Although the hes gene was detected less frequently, the presence of at least one of these three genes in a significant proportion of STEC suggests the potential of this vaccine to target a wide range of strains. The vaccination of pregnant sows led to an increase in specific IgG and IgA antibodies against the chimeric proteins, indicating successful immunization. Additionally, our results demonstrated the effective passive transfer of maternal antibodies to piglets, providing them with immediate, albeit temporary, humoral immunity against STEC. These humoral responses demonstrate the immunogenicity of the vaccine candidate and are preliminary indicators of its potential efficacy. However, further research is needed to conclusively evaluate its impact on STEC colonization and shedding. This study highlights the potential of maternal vaccination to protect piglets from ED and contributes to the development of vaccination strategies to reduce the prevalence of STEC in various animal reservoirs.

Characterization of antimicrobial resistance profiles in Escherichia coli isolated from captive mammals in Ecuador.

BACKGROUND: This study focuses on the AMR profiles in E. coli isolated from captive mammals at EcoZoo San Martín, Baños de Agua Santa, Ecuador, highlighting the role of wildlife as reservoirs of resistant bacteria. AIMS: The aim of this research is to investigate the antimicrobial resistance profiles of E. coli strains isolated from various species of captive mammals, emphasizing the potential zoonotic risks and the necessity for integrated AMR management strategies. MATERIALS & METHODS: A total of 189 fecal samples were collected from 70 mammals across 27 species. These samples were screened for E. coli, resulting in 90 identified strains. The resistance profiles of these strains to 16 antibiotics, including 10 ß-lactams and 6 non-ß-lactams, were determined using the disk diffusion method. Additionally, the presence of Extended-Spectrum Beta-Lactamase (ESBL) genes and other resistance genes was analyzed using PCR. RESULTS: Significant resistance was observed, with 52.22% of isolates resistant to ampicillin, 42.22% to ceftriaxone and cefuroxime, and 27.78% identified as ESBL-producing E. coli. Multiresistance (resistance to more than three antibiotic groups) was found in 35.56% of isolates. Carnivorous and omnivorous animals, particularly those with prior antibiotic treatments, were more likely to harbor resistant strains. DISCUSSION: These findings underscore the role of captive mammals as indicators of environmental AMR. The high prevalence of resistant E. coli in these animals suggests that zoos could be significant reservoirs for the spread of antibiotic-resistant bacteria. The results align with other studies showing that diet and antibiotic treatment history influence resistance profiles. CONCLUSION: The study highlights the need for an integrated approach involving veterinary care, habitat management, and public awareness to prevent captive wildlife from becoming reservoirs of antibiotic-resistant bacteria. Improved waste management practices and responsible antibiotic use are crucial to mitigate the risks of AMR in zoo environments and reduce zoonotic threats.

Antibiofilm activity of promethazine against ESBL-producing strains of Escherichia coli in urinary catheters.

The bacterium Escherichia coli is one of the main causes of urinary tract infections. The formation of bacterial biofilms, especially associated with the use of urinary catheters, contributes to the establishment of recurrent infections and the development of resistance to treatment. Strains of E. coli that produce extended-spectrum beta-lactamases (ESBL) have a greater ability to form biofilms. In addition, there is a lack of drugs available in the market with antibiofilm activity. Promethazine (PMZ) is an antihistamine known to have antimicrobial activity against different pathogens, including in the form of biofilms, but there are still few studies of its activity against ESBL E. coli biofilms. The aim of this study was to evaluate the antimicrobial activity of PMZ against ESBL E. coli biofilms, as well as to assess the application of this drug as a biofilm prevention agent in urinary catheters. To this end, the minimum inhibitory concentration and minimum bactericidal concentration of PMZ in ESBL E. coli strains were determined using the broth microdilution assay and tolerance level measurement. The activity of PMZ against the cell viability of the in vitro biofilm formation of ESBL E. coli was analyzed by the MTT colorimetric assay and its ability to prevent biofilm formation when impregnated in a urinary catheter was investigated by counting colony-forming units (CFU) and confirmed by scanning electron microscopy (SEM). PMZ showed bactericidal activity and significantly reduced (p < 0.05) the viability of the biofilm being formed by ESBL E. coli at concentrations of 256 and 512 µg/ml, as well as preventing the formation of biofilm on urinary catheters at concentrations starting at 512 µg/ml by reducing the number of CFUs, as also observed by SEM. Thus, PMZ is a promising candidate to prevent the formation of ESBL E. coli biofilms on abiotic surfaces.

A natural approach to combating antibiotic-resistant pathogens in livestock: Hibiscus sabdariffa-derived hibiscus acid as a promising solution.

We examined the antibacterial efficacy of streptomycin, hibiscus acid, and their combination against multidrug-resistant Shiga-toxin-producing Escherichia coli (STEC) and Salmonella Typhimurium in mice. We determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for streptomycin, hibiscus acid, and their combination against STEC and Salmonella. Fifteen sets of six mice in each set were utilised: six groups were orally exposed to 4 log10 colony forming units (CFUs) of S. Typhimurium and another six to STEC, and three acted as the controls. Six hours post-inoculation, specific groups of mice received either oral solutions containing hibiscus acid at 5 and 7 mg/ml; streptomycin at 50 and 450 µg/ml; hibiscus acid/streptomycin (5 mg/ml hibiscus acid and 50 µg/ml streptomycin); or isotonic saline. The study determined the MIC and MBC of 7 mg/ml of hibiscus acid; 300 and 450 µg/ml of streptomycin; and two concentrations of hibiscus/streptomycin (3 mg/ml / 20 µg/ml and 5 mg/ml / 50 µg/ml). Interestingly, the mice that were infected and subsequently treated with hibiscus acid at 7 mg/ml alone or in conjunction with streptomycin did not have either STEC or Salmonella in their faecal samples, and none of the mice died. In contrast, the untreated mice and those exclusively treated with streptomycin had the pathogens present in their stool, leading to the mortality of all the subjects.

Distribution of papA and papG Variants among Escherichia coli Genotypes: Association with Major Extraintestinal Pathogenic Lineages.

The pyelonephritis-associated fimbria (P fimbria) is one of the most recognized adhesion determinants of extraintestinal pathogenic Escherichia coli strains (ExPECs). Twelve variants have been described for the gene encoding the P fimbria major structural subunit PapA and three variants for the gene encoding the adhesin subunit PapG. However, their distribution among the ExPEC diversity has not been comprehensively addressed. A complete landscape of that distribution might be valuable for delineating basic studies about the pathogenicity mechanisms of ExPECs and following up on the evolution of ExPEC lineages, particularly those most epidemiologically relevant. Therefore, we performed a massive descriptive study to detect the papA and papG variants along different E. coli genotypes represented by genomic sequences contained in the NCBI Assembly Refseq database. The most common papA variants were F11, F10, F48, F16, F12, and F7-2, which were found in significant association with the most relevant ExPEC genotypes, the phylogroups B2 and D, and the sequence types ST95, ST131, ST127, ST69, ST12, and ST73. On the other hand, the papGII variant was by far the most common followed by papGIII, and both were also found to have a significant association with common ExPEC genotypes. We noticed the presence of genomes, mainly belonging to the sequence type ST12, harboring two or three papA variants and two papG variants. Furthermore, the most common papA and papG variants were also detected in records representing strains isolated from humans and animals such as poultry, bovine, and dogs, supporting previous hypotheses of potential cross-transmission. Finally, we characterized a set of 17 genomes from Chilean uropathogenic E. coli strains and found that ST12 and ST73 were the predominant sequence types. Variants F7-1, F7-2, F8, F9, F11, F13, F14, F16, and F48 were detected for papA, and papGII and papGIII variants were detected for papG. Significant associations with the sequence types observed in the analysis of genomes contained in the NCBI Assembly Refseq database were also found in this collection in 16 of 19 cases for papA variants and 7 of 9 cases for the papG variants. This comprehensive characterization might support future basic studies about P fimbria-mediated ExPEC adherence and future typing or epidemiological studies to monitor the evolution of ExPECs producing P fimbria.

Exploring the Antimicrobial Efficacy of Low-Cost Commercial Disinfectants Utilized in the Agro-Food Industry Wash Tanks: Towards Enhanced Hygiene Practices.

The increase in vegetable consumption has underlined the importance of minimizing the risks associated with microbiological contamination of fresh produce. The critical stage of the vegetable washing process has proven to be a key point for cross-contamination and the persistence of pathogens. In this context, the agri-food industry has widely adopted the use of disinfectants to reduce the bacterial load in the wash water. Therefore, we conducted laboratory-scale experiments in order to demonstrate the antimicrobial activity of disinfectants used in the wash tank of agro-food industries. Different wash water matrices of shredded lettuce, shredded cabbage, diced onion, and baby spinach were treated with sodium hypochlorite (NaClO), chlorine dioxide (ClO2), and per-oxyacetic acid (PAA) at recommended concentrations. To simulate the presence of pathogenic bacteria, a cocktail of E. coli O157:H7 was inoculated into the process water samples (PWW) to determine whether concentrations of disinfectants inhibit the pathogen or bring it to a viable non-culturable state (VBNC). Hereby, we used quantitative qPCR combined with different photo-reactive dyes such as ethidium monoazide (EMA) and propidium monoazide (PMA). The results indicated that concentrations superior to 20 ppm NaClO inhibit the pathogen E. coli O157:H7 artificially inoculated in the process water. Concentrations between 10-20 ppm ClO2 fail to induce the pathogen to the VBNC state. At concentrations of 80 ppm PAA, levels of culturable bacteria and VBNC of E. coli O157:H7 were detected in all PWWs regardless of the matrix. Subsequently, this indicates that the recommended concentrations of ClO2 and PAA for use in the fresh produce industry wash tank do not inhibit the levels of E. coli O157:H7 present in the wash water.

Presence of Indicator Bacteria and Occurrence of Potentially Pathogenic Nontuberculous Mycobacteria Species in Packaged Ice Cubes in Central Mexico.

This study aimed to determine the bacteriological quality and presence of diarrheagenic Escherichia coli pathotypes (DEP) and nontuberculous mycobacteria (NTM) species in 85 packaged ice samples from 12 different states of central Mexico. Three samples had a pH of 9.8 and therefore fell outside of the acceptable range for pH. All samples were positive for aerobic-mesophilic bacteria, with limits ranging from 1 to 3.47 log CFU/mL. In total, 35, 11, and 3 ice samples were positive for total coliforms (TC), fecal coliforms (FC), and E. coli, respectively. In the samples, the TC concentration ranged from <1.1 to >23 MPN/100 mL and from <1.1 to 23 MPN/100 mL for FC and E. coli. In total, 38 (44.7%) ice samples were outside of Mexico's official guidelines. None of the 12 E. coli strains isolated from the three ice samples belonged to DEP. NTM were recovered from 20 ice samples and included M. neoaurum (n = 7), M. porcinum (n = 2), M. flavescens (n = 2), M. fortuitum (n = 1), M. abscessus (n = 1), M. senegalense (n = 1), M. conceptionense (n = 1), and M. sp. (n = 1). In the remaining four samples, two NTM were isolated simultaneously. Thus, we recommend that producers should evaluate the microbiological quality of purified water used as a raw material as well as that of the final product, the ice should be packed in thick bags to avoid stretching and tearing during transportation or storage to prevent environmental contamination of ice, personnel involved in the production, and handling of ice should be trained in relative hygiene matters and how ice-machines should be cleaned and disinfected and the implementation of hazard analysis and critical control points must be applied throughout the chain of production. Finally, regular inspection by the authorities is also of great importance. These recommendations can be applied in different countries with low microbiological quality packaged ice.

The detection of KPC-2, NDM-1, and VIM-2 carbapenemases in international clones isolated from fresh vegetables highlights an emerging food safety issue.

Resistance to carbapenems emerged in clinical settings and has rapidly spread to other sectors, such as food and the environment, representing a One Health problem. In this regard, vegetables contaminated by critical priority pathogens have raised global concerns. Here, we have performed a whole-genome sequence-based analysis of extensively drug-resistant Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa strains isolated from cabbage, spinach, and lettuce, respectively. Genomic analysis revealed the emergence of international and high-risk clones belonging to ST340, ST155, and ST233, harboring a broad resistome to clinically important antimicrobials. In this context, K. pneumoniae, E. coli, and P. aeruginosa strains carried blaKPC-2, blaNDM-1, and blaVIM-2, respectively. The blaKPC-2 gene with a non-Tn4401 element (NTEKPC-Ic) was located on an IncX3-IncU plasmid, while the blaVIM-2 gene was associated with a Tn402-like class 1 integron, In559, on the chromosome. Curiously, the blaNDM-1 gene coexisted with the blaPER-2 gene on an IncC plasmid and the regions harboring both genes contained sequences of Tn3-like element ISKox2-like family transposase. Comparative genomic analysis showed interspecies and clonal transmission of carbapenemase-encoding genes at the human-animal-environmental interface. These findings raise a food safety alert about hospital-associated carbapenemase producers, supporting that fresh vegetables can act as a vehicle for the spread of high-risk clones.

Development of Predictive Modeling for Removal of Multispecies Biofilms of Salmonella Enteritidis, Escherichia coli, and Campylobacter jejuni from Poultry Slaughterhouse Surfaces.

Salmonella Enteritidis, Escherichia coli, and Campylobacter jejuni are among the most common foodborne pathogens worldwide, and poultry products are strongly associated with foodborne pathogen outbreaks. These pathogens are capable of producing biofilms on several surfaces used in the food processing industry, including polyethylene and stainless steel. However, studies on multi-species biofilms are rare. Therefore, this study aimed to develop predictive mathematical models to simulate the adhesion and removal of multispecies biofilms. All combinations of microorganisms resulted in biofilm formation with differences in bacterial counts. E. coli showed the greatest ability to adhere to both surfaces, followed by S. Enteritidis and C. jejuni. The incubation time and temperature did not influence adhesion. Biofilm removal was effective with citric acid and benzalkonium chloride but not with rhamnolipid. Among the generated models, 46 presented a significant coefficient of determination (R2), with the highest R2 being 0.88. These results provide support for the poultry industry in creating biofilm control and eradication programs to avoid the risk of contamination of poultry meat.

Recombinant multiepitope proteins expressed in Escherichia coli cells and their potential for immunodiagnosis.

Recombinant multiepitope proteins (RMPs) are a promising alternative for application in diagnostic tests and, given their wide application in the most diverse diseases, this review article aims to survey the use of these antigens for diagnosis, as well as discuss the main points surrounding these antigens. RMPs usually consisting of linear, immunodominant, and phylogenetically conserved epitopes, has been applied in the experimental diagnosis of various human and animal diseases, such as leishmaniasis, brucellosis, cysticercosis, Chagas disease, hepatitis, leptospirosis, leprosy, filariasis, schistosomiasis, dengue, and COVID-19. The synthetic genes for these epitopes are joined to code a single RMP, either with spacers or fused, with different biochemical properties. The epitopes' high density within the RMPs contributes to a high degree of sensitivity and specificity. The RMPs can also sidestep the need for multiple peptide synthesis or multiple recombinant proteins, reducing costs and enhancing the standardization conditions for immunoassays. Methods such as bioinformatics and circular dichroism have been widely applied in the development of new RMPs, helping to guide their construction and better understand their structure. Several RMPs have been expressed, mainly using the Escherichia coli expression system, highlighting the importance of these cells in the biotechnological field. In fact, technological advances in this area, offering a wide range of different strains to be used, make these cells the most widely used expression platform. RMPs have been experimentally used to diagnose a broad range of illnesses in the laboratory, suggesting they could also be useful for accurate diagnoses commercially. On this point, the RMP method offers a tempting substitute for the production of promising antigens used to assemble commercial diagnostic kits.

Effects of dietary yeast mannan-rich fraction supplementation on growth performance, intestinal morphology, and lymphoid tissue characteristics in weaned piglets challenged with Escherichia Coli F4.

We evaluated the effects of supplementing yeast mannan-reach-fraction on growth performance, jejunal morphology and lymphoid tissue characteristics in weaned piglets challenged with E. Coli F4. A total of 20 crossbred piglets were used. At weaning, piglets were assigned at random to one of four groups: piglets challenged and fed the basal diet supplemented with yeast mannan-rich fraction (C-MRF, n = 5); piglets challenged and fed the basal diet (C-BD, n = 5); piglets not challenged and fed the basal diet supplemented with yeast mannan-rich fraction (NC-MRF, n = 5), and piglets not challenged and fed the basal diet (NC-BD). Each dietary treatment had five replicates. On days 4, 5 and 10, piglets were orally challenged with 108 CFU/mL of E. Coli F4. C-MRF piglets had higher BW (p = 0.002; interactive effect) than C-BD piglets. C-MRF piglets had higher (p = 0.02; interactive effect) ADG in comparison with C-BD piglets. C-MRF piglets had higher (p = 0.04; interactive effect) ADFI than C-BD piglets. The diameter of lymphoid follicles was larger (p = 0.010; interactive effect) in the tonsils of C-MRF piglets than C-BD piglets. Lymphoid cells proliferation was greater in the mesenteric lymphnodes and ileum (p = 0.04 and p = 0.03, respectively) of C-MRF piglets. A reduction (p > 0.05) in E. Coli adherence in the ileum of piglets fed MRF was observed. In conclusion, the results of the present study demonstrate that dietary yeast mannan-rich fraction supplementation was effective in protecting weaned piglets against E. Coli F4 challenge.

Chromosomal qnrB19-carrying Escherichia coli isolated from the stool sample of a community resident in Ecuador.

We identified a chromosomal qnrB19 gene within a transposon in a colistin-resistant Escherichia coli strain isolated from the stool sample of an Ecuadorian resident. This finding suggests a more stable acquisition of quinolone resistance on chromosomes than that on plasmids and the potential for propagation to other DNA structures.