Meat ducks as carriers of antimicrobial-resistant Escherichia coli harboring transferable R plasmids.

IMPORTANCE: Antimicrobial resistance (AMR) is a serious public health threat. AMR bacteria and their resistance determinants in food can be transmitted to humans through the food chain and by direct contact and disseminate directly to the environment. OBJECTIVE: This study examined the AMR characteristics and transferable R plasmids in Escherichia coli isolated from meat ducks raised in an open-house system. METHODS: One hundred seventy-seven (n = 177) commensal E. coli were examined for their antimicrobial susceptibilities and horizontal resistance transfer. The plasmids were examined by PCR-based plasmid replicon typing (PBRT) and plasmid multi-locus sequence typing (pMLST). RESULTS: The highest resistance rate was found against ampicillin (AMP, 83.0%) and tetracycline (TET, 81.9%), and most isolates exhibited multidrug resistance (MDR) (86.4%). The R plasmids were conjugally transferred when TET (n = 4), AMP (n = 3), and chloramphenicol (n = 3) were used as a selective pressure. The three isolates transferred resistance genes either in AMP or TET. The blaCTX-M1 gene resided on conjugative plasmids. Five replicon types were identified, of which Inc FrepB was most common in the donors (n = 13, 38.4%) and transconjugants (n = 16, 31.2%). Subtyping F plasmids revealed five distinct replicons combinations, including F47:A-:B- (n = 2), F29:A-:B23 (n = 1), F29:A-:B- (n = 1), F18:A-B:- (n = 1), and F4:A-:B- (n = 1). The chloramphenicol resistance was significantly correlated with the other AMR phenotypes (p < 0.05). CONCLUSIONS AND RELEVANCE: The meat ducks harbored MDR E. coli and played an important role in the environmental dissemination of AMR bacteria and its determinants. This confirms AMR as a health issue, highlighting the need for routine AMR monitoring and surveillance of meat ducks.

Identification and characterization of CIM-1, a carbapenemase that adds to the family of resistance factors against last resort antibiotics.

The increasing rate of carbapenem-resistant bacteria within healthcare environments is an issue of great concern that needs urgent attention. This resistance is driven by metallo-ß-lactamases (MBLs), which can catalyse the hydrolysis of almost all clinically available ß-lactams and are resistant to all the clinically utilized ß-lactamase inhibitors. In this study, an uncharacterized MBL is identified in a multidrug resistant isolate of the opportunistic pathogen, Chryseobacterium indologenes. Sequence analysis predicts this MBL (CIM-1) to be a lipoprotein with an atypical lipobox. Characterization of CIM-1 reveals it to be a high-affinity carbapenemase with a broad spectrum of activity that includes all cephalosporins and carbapenems. Results also shown that CIM-1 is potentially a membrane-associated MBL with an uncharacterized lipobox. Using prediction tools, we also identify more potentially lipidated MBLs with non-canonical lipoboxes highlighting the necessity of further investigation of lipidated MBLs.

Exploiting the aggregation propensity of beta-lactamases to design inhibitors that induce enzyme misfolding.

There is an arms race between beta-lactam antibiotics development and co-evolving beta-lactamases, which provide resistance by breaking down beta-lactam rings. We have observed that certain beta-lactamases tend to aggregate, which persists throughout their evolution under the selective pressure of antibiotics on their active sites. Interestingly, we find that existing beta-lactamase active site inhibitors can act as molecular chaperones, promoting the proper folding of these resistance factors. Therefore, we have created Pept-Ins, synthetic peptides designed to exploit the structural weaknesses of beta-lactamases by causing them to misfold into intracellular inclusion bodies. This approach restores sensitivity to a wide range of beta-lactam antibiotics in resistant clinical isolates, including those with Extended Spectrum variants that pose significant challenges in medical practice. Our findings suggest that targeted aggregation of resistance factors could offer a strategy for identifying molecules that aid in addressing the global antibiotic resistance crisis.

The chloroplast protein HCF164 is predicted to be associated with Coffea SH9 resistance factor against Hemileia vastatrix.

To explore the connection between chloroplast and coffee resistance factors, designated as SH1 to SH9, whole genomic DNA of 42 coffee genotypes was sequenced, and entire chloroplast genomes were de novo assembled. The chloroplast phylogenetic haplotype network clustered individuals per species instead of SH factors. However, for the first time, it allowed the molecular validation of Coffea arabica as the maternal parent of the spontaneous hybrid "Híbrido de Timor". Individual reads were also aligned on the C. arabica reference genome to relate SH factors with chloroplast metabolism, and an in-silico analysis of selected nuclear-encoded chloroplast proteins (132 proteins) was performed. The nuclear-encoded thioredoxin-like membrane protein HCF164 enabled the discrimination of individuals with and without the SH9 factor, due to specific DNA variants linked to chromosome 7c (from C. canephora-derived sub-genome). The absence of both the thioredoxin domain and redox-active disulphide center in the HCF164 protein, observed in SH9 individuals, raises the possibility of potential implications on redox regulation. For the first time, the identification of specific DNA variants of chloroplast proteins allows discriminating individuals according to the SH profile. This study introduces an unexplored strategy for identifying protein/genes associated with SH factors and candidate targets of H. vastatrix effectors, thereby creating new perspectives for coffee breeding programs.

Mismatch Repair system protein deficiency as a resistance factor for locally advanced rectal adenocarcinoma patients receiving neoadjuvant chemo-radiotherapy.

BACKGROUND: Available data on Mismatch Repair system (MMR) deficiency are conflicting and derived from small studies. Our study aimed to evaluate the therapeutic implications of MMR status in patients with locally advanced rectal cancer (LARC). METHODS: We retrospectively collected data from 318 patients affected by LARC treated in Italy at the Medical Oncology Units of the University Hospital of Cagliari, Istituto Nazionale dei Tumori Milan, and AOU Ospedali Riuniti Ancona. All patients underwent neoadjuvant chemoradiotherapy. The primary objective was major TRG while secondary objectives were pathological complete response, disease-free survival (DFS) and overall survival (OS). RESULTS: One hundred sixty patients (148 pMMR and 12 dMMR) were included in the exploratory cohort and 158 (146 pMMR and 12 dMMR) were included in the validation cohort. A major TRG has been shown in 42.6% and 43.1% patients with pMMR in exploratory and validation cohort, respectively; while no major TRG have been shown in dMMR patients in both cohorts. Exploratory and validation cohorts showed a statistically significant higher mDFS in pMMR patients compared to dMMR: NR vs. 14 months and NR vs. 17 months, respectively. CONCLUSION: Our results indicated an association between dMMR and poor response to preoperative chemoradiotherapy and they represent a hypothesis-generating data for new neoadjuvant strategies.

Genome sequence of Vibrio anguillarum isolates carrying a novel class A ß-lactamase VAN-1: do migratory fish transport novel resistance factors?

OBJECTIVES: The aim of the study was to understand the genetic basis of resistance of five ß-lactam resistant Vibrio anguillarum isolates obtained from the gut content of Atlantic mackerel (Scomber scomberus), using whole genome sequencing and to characterize a novel ß-lactamase (VAN-1) from these isolates. METHOD: Antibiotic sensitivity pattern was determined using Sensititre™ plates and whole genome sequencing was carried out using Illumina MiSeq-based sequencing. The blaVAN-1 gene was synthesized and expressed in Escherichia coli Top10 cells. RESULTS: Five isolates obtained (out of 73) from the gut content of Atlantic mackerel were identified as Vibrio anguillarum. Whole genome assemblies ranged from 3.894 to 3.906 million bases in length with an average of 50 contigs. A novel ß-lactamase blaVAN-1, sharing 77.7% nucleotide identity with a known mobile ß-lactamase from Vibrio species was detected. The blaVAN-1 gene in these isolates is flanked by a truncated IS5 family transposase on one end and a hypothetical protein and outer membrane protein followed by another IS5 family transposase on the other end, suggesting its potential for mobility. The blaVAN-1 gene was absent in V. anguillarum type strain (ATCC 14181) and V. anguillarum isolates from bivalves and sea water in Norway. VAN-1 conferred ampicillin resistance when expressed in E. coli, thus confirming the functionality of this gene. CONCLUSIONS: Our study highlights the importance of the marine environment as a reservoir of new antibiotic resistance genes. Our results suggest that migratory fish may transport novel antibiotic resistance determinants over long distances.

Efecto del extracto hexánico de Tagetes lucida sobre la inhibición del crecimiento de enterobacterias Shigella flexneri y Salmonella typhi / Effect of the hexanic extract of Tagetes lucida on the inhibition of the growth of enterobacteria Shigella flexneri and Salmonella typhi

La resistencia a los antibióticos aumenta la búsqueda de nuevas estrategias para combatir las enfermedades que causan, y el uso de plantas medicinales representa una estrategia altamente efectiva y valiosa, como el uso de Tagetes lucida con diferentes bacterias gram positivas y gram negativas.Objetivo: Evaluar la actividad biológica que tiene el extracto hexanico de la planta Tagetes lucida a diferentes concentraciones sobre la inhibición del crecimiento en placa y tubo de dos enterobacterias, Shigella flexneri y Salmonella typhiMétodos: En el siguiente trabajo, se evaluó un extracto de hexano de Tagetes lucida sobre la inhibición del crecimiento de dos enterobacterias, Shigella flexneri y Salmonella typhi utilizando diferentes concentraciones de vehículo para evaluar si afectaba el crecimiento bacteriano y también diferentes concentraciones de extracto para evaluar la actividad.Resultados: Realizados los estudios por triplicado se logró concretar que a partir de 75µl/µg de extracto se logra una inhibición casi total del crecimiento de ambas bacterias, tanto en método de placa, como en método de tubo. Y a partir de 100 µl/µg se logra una inhibición total.Conclusiones: Los resultados favorables obtenidos con 75 µl/µg, permiten confirmar que los extractos de plantas medicinales son una estrategia importante para combatir infecciones bacterianas multi-resistentes. Por otro lado permite dar paso a un estudio para evaluar los metabolitos más activos del extracto, así como, el mecanismo de acción sobre la inhibición del crecimiento de las bacterias en estudio. (AU)

Antibiotic resistance increases the search for new strategies to combat the diseases they cause, and the use of medicinal plants represents a highly effective and valuable strategy, such as the use of Tagetes lucida with different gram positive and gram negative bacteria.Objective: To evaluate the biological activity of the hexane extract of the Tagetes lucida plant at different concentrations on the inhibition of growth in plaque and tube of two enterobacteriaceae, Shigella flexneri and Salmonella typhiMethods: In the following work, a hexane extract from Tagetes lucida was evaluated on the growth inhibition of two enterobacteriaceae, Shigella flexneri and Salmonella typhi using different concentrations of vehicle to evaluate if it affected bacterial growth and also different concentrations of extract to evaluate activity.Results: Once the studies were carried out in triplicate, it was possible to specify that from 75µl/µg of extract, almost total inhibition of the growth of both bacteria was achieved, both in the plate method and in the tube method. And from 100 µl/µg total inhibition is achieved.Conclusions: The favorable results obtained with 75 µl/ µg, confirm that medicinal plant extracts are an important strategy to combat multi-drug resistant bacterial infections. On the other hand, it allows a study to be carried out to evaluate the most active metabolites of the extract, as well as the mechanism of action on the inhibition of the growth of the bacteria under study. (AU)

Genes involucrados con resistencia antimicrobiana en hospitales del Ecuador / Genes involved with antimicrobial resistance in Ecuadorian hospitals

INTRODUCCIÓN. La resistencia a los antimicrobianos es un problema de salud pública actual asociado con alta mortalidad, hospitalización prolongada, alternativas terapéuticas reducidas, mayores costos económicos y la posibilidad de brotes hospitalarios. OBJETIVO. Describir los principales genes involucrados con resistencia antimicrobiana en hospitales del Ecuador. MATERIALES Y MÉTODOS. Se realizó una descripción retrospectiva no experimental, de artículos indexados relacionados con resistencia antimicrobiana en hospitales del Ecuador, con evidencia desde el año 2009 al 2022. La revisión de bibliografías se llevó a cabo en bases de datos como Pubmed, Science Direct y Google Scholar. RESULTADOS. De un grupo original de 77 artículos, se seleccionaron 33 documentos. En Ecuador, varios estudios han descrito los mecanismos moleculares involucrados en la resistencia bacteriana. Sin embargo, en bacterias menos comunes, falta investigación sobre los genes asociados. CONCLUSIONES. Las principales bacterias multirresistentes descritas en Ecuador son Klebsiella pneumoniae, Escherichia coli y Acinetobacter baumanni, las cuales presentan genes involucrados en la producción de carbapenemasas (blaKPC, blaNDM, blaOXA-48). Estas bacterias presentan altos niveles de resistencia a los antibióticos y son objeto de vigilancia epidemiológica por parte del sistema nacional de salud. A nivel local, otras bacterias presentan mecanismos de resistencia a los carbapenémicos (Pseudomonas aeruginosa, Enterobacter sp., Serratia marcescens, Citrobacter sp.), pero no existen descripciones detalladas del genotipo, sus características microbiológicas o la clínica del paciente. El conocimiento de las tasas de resistencia a los antimicrobianos en los diferentes hospitales, la implementación de un plan de administración de antibióticos, el uso correcto de los equipos de protección personal, el aislamiento de las personas con infecciones multirresistentes, así como el trabajo colaborativo entre las diferentes áreas del hospital, son esenciales para reducir la propagación de estos patógenos.

INTRODUCTION. Antimicrobial resistance is a current public health problem associated with high mortality, prolonged hospitalization, reduced therapeutic alternatives, increased economic costs, and the potential for hospital outbreaks. OBJECTIVE. To describe the main genes involved with antimicrobial resistance in hospitals in Ecuador. MATERIALS AND METHODS. A retrospective non-experimental description of indexed articles related to antimicrobial resistance in hospitals in Ecuador was carried out, with evidence from 2009 to 2022. The review of bibliographies was carried out in databases such as Pubmed, Science Direct and Google Scholar. RESULTS. From an original group of 77 articles, 33 papers were selected. In Ecuador, several studies have described the molecular mechanisms involved in bacterial resistance. However, in less common bacteria, research on the associated genes is lacking. CONCLUSIONS. The main multidrug-resistant bacteria described in Ecuador are Klebsiella pneumoniae, Escherichia coli and Acinetobacter baumanni, which present genes involved in the production of carbapenemases (blaKPC, blaNDM, blaOXA-48). These bacteria present high levels of antibiotic resistance and are subject to epidemiological surveillance by the national health system. Locally, other bacteria present mechanisms of resistance to carbapenemics (Pseudomonas aeruginosa, Enterobacter sp., Serratia marcescens, Citrobacter sp.), but there are no detailed descriptions of the genotype, their microbiological characteristics or the patient's clinic. Knowledge of antimicrobial resistance rates in different hospitals, the implementation of an antibiotic stewardship plan, the correct use of personal protective equipment, the isolation of individuals with multidrug-resistant infections, as well as collaborative work between different areas of the hospital, are essential to reduce the spread of these pathogens.

Anticoagulant rodenticide blood-clotting dose-responses and resistance factors for Tyrosine139Cysteine (Y139C) heterozygous- and homozygous-resistant house mice (Mus musculus).

BACKGROUND: The house mouse (Mus musculus) is a globally distributed rodent pest species against which anticoagulant rodenticides are widely used for the protection of human and animal health and the conservation of threatened wildlife. Anticoagulant-resistant house mice have been known for more than half a century. A house mouse strain was developed in the laboratory that was homozygous resistant for the single nucleotide polymorphism (SNP) Tyrosine139Cysteine (Y139C) and, subsequently, heterozygous resistant animals were produced from this strain by crossing with the homozygous susceptible strain. RESULTS: Using blood clotting response tests, resistance factors at the ED50 level in the homozygous resistant strain for the first-generation anticoagulants warfarin, chlorophacinone, diphacinone and coumatetralyl were in the range 31.5 to 628.0 for males (M) and 21.6 to 628.0 for females (F), thus indicating that Y139C house mice are substantially resistant to all these substances. Resistance factors at the ED50 level for the homozygous strain generated against the second-generation compounds were: brodifacoum (M, 1.7; F, 1.9), bromadiolone (M, 16.6; F, 21.0), difenacoum (M, 1.2; F, 2.7), difethialone (M, 1.5; F, 1.5), and flocoumafen (M, 0.9; F, 1.2). Equivalent values for the heterozygous strain were: brodifacoum (M, 1.6; F, 1.4), bromadiolone (M, 5.6; F, 6.5), difenacoum (M, 1.0; F, 1.3), difethialone (M, 1.1; F, 1.1), flocoumafen (M, 0.9; F, 1.1). CONCLUSION: Y139C SNP homozygous resistant mice are more resistant to anticoagulants than heterozygous resistant animals. All first-generation anticoagulants are highly resisted and, among the second-generation compounds, Y139C mice are resistant to bromadiolone and sometimes to difenacoum. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genomic Amplification of UBQLN4 Is a Prognostic and Treatment Resistance Factor.

Ubiquilin-4 (UBQLN4) is a proteasomal shuttle factor that directly binds to ubiquitylated proteins and delivers its cargo to the 26S proteasome for degradation. We previously showed that upregulated UBQLN4 determines the DNA damage response (DDR) through the degradation of MRE11A. However, the regulatory mechanism at DNA level, transcriptionally and post-transcriptional levels that control UBQLN4 mRNA levels remains unknown. In this study, we screened 32 solid tumor types and validated our findings by immunohistochemistry analysis. UBQLN4 is upregulated at both mRNA and protein levels and the most significant values were observed in liver, breast, ovarian, lung, and esophageal cancers. Patients with high UBQLN4 mRNA levels had significantly poor prognoses in 20 of 32 cancer types. DNA amplification was identified as the main mechanism promoting UBQLN4 upregulation in multiple cancers, even in the early phases of tumor development. Using CRISPR screen datasets, UBQLN4 was identified as a common essential gene for tumor cell viability in 81.1% (860/1,060) of the solid tumor derived cell lines. Ovarian cancer cell lines with high UBQLN4 mRNA levels were platinum-based chemotherapy resistant, while they were more sensitive to poly (adenosine diphosphate-ribose) polymerase inhibitors (PARPi). Our findings highlight the utilities of UBQLN4 as a significant pan-cancer theranostic factor and a precision oncology biomarker for DDR-related drug resistance.