Characterization and synergy studies of Caudoviricete Escherichia phage FS2B infecting multi-drug resistant uropathogenic Escherichia coli isolates / Estudios de caracterización y sinergia del fago FS2B de Caudoviricete Escherichia que infecta aislados de Escherichia coli uropatógena multirresistente

Escherichia coli is one of the most common causes of urinary tract infections. However, a recent upsurge in antibiotic resistance among uropathogenic E. coli (UPEC) strains has provided an impetus to explore alternative antibacterial compounds to encounter this major issue. In this study, a lytic phage against multi-drug-resistant (MDR) UPEC strains was isolated and characterized. The isolated Escherichia phage FS2B of class Caudoviricetes exhibited high lytic activity, high burst size, and a small adsorption and latent time. The phage also exhibited a broad host range and inactivated 69.8% of the collected clinical, and 64.8% of the identified MDR UPEC strains. Further, whole genome sequencing revealed that the phage was 77,407 bp long, having a dsDNA with 124 coding regions. Annotation studies confirmed that the phage carried all the genes associated with lytic life cycle and all lysogeny related genes were absent in the genome. Further, synergism studies of the phage FS2B with antibiotics demonstrated a positive synergistic association among them. The present study therefore concluded that the phage FS2B possesses an immense potential to serve as a novel candidate for treatment of MDR UPEC strains.(AU)

In vitro assessment of biofunctional properties of Lactiplantibacillus plantarum strain Jb21-11 and the characterization of its exopolysaccharide / Evaluación in vitro de las propiedades biofuncionales de Lactiplantibacillus plantarum cepa Jb21-11 y caracterización de su exopolisacárido

The microbiota of traditional food provides a rich reservoir of biodiversity to find new strains with interesting features for novel functional food formulation. Therefore, this study aimed to investigate the biofunctional potential of the lactic acid bacteria (LAB) strain Jb21-11 isolated from Jben, a traditional Algerian fresh cheese. This isolate was selected out of a collection of 154 LAB based on its exopolysaccharide (EPS) phenotype and was preliminarily identified by polyphasic characterization as Lactiplantibacillus plantarum (previously known as Lactobacillus plantarum) and its biofunctional properties were then assessed in vitro. The tested strain demonstrated good resistance to gastric juice, acidity around pH 2, and 2% (v/v) bile salts, which are important characteristics for potential biofunctional LAB candidates. It also showed a good production of ropy EPS with 674 mg/L on MRS medium. However, this ability appears to compromise the adhesion of the strain to Caco-2 cells (less than 1%), which according to our results, seems not to be related to autoaggregation and hydrophobicity (44.88 ± 0.028% and 16.59 ± 0.012%). Furthermore, promising antimicrobial activity against three pathogenic bacteria (Escherichia coli, Staphylococcus aureus, and Salmonella) was detected probably due to antimicrobial metabolites excreted during fermentation process into the medium. Moreover, the strain L. plantarum Jb21-11 displayed a therapeutic functionality with both anti-inflammatory and immunomodulatory action using RAW 264.7 cells. The chemical features of the novel ropy Jb21-11-EPS were also investigated revealing the presence of three monosaccharides, namely, mannose, galactose, and glucose, with a molar ratio of 5.42:1.00:4.52 linked together by α- and β-glycosidic bonds, presenting a relatively high molecular weight of 1.08 × 105 Da of interest for a texturing potential. Therefore, the new producing EPS strain Jb21-11 is a promising candidate for use as an adjunct culture for improving the texture of functional food.(AU)

An efflux pump in genomic island GI-M202a mediates the transfer of polymyxin B resistance in Pandoraea pnomenusa M202 / Una bomba de eflujo en la isla genómica GI-M202a media la transferencia de resistencia a la polimixina B en Pandoraea pnomenusa M202

Background: Polymyxin B is considered a last-line therapeutic option against multidrug-resistant gram-negative bacteria, especially in COVID-19 coinfections or other serious infections. However, the risk of antimicrobial resistance and its spread to the environment should be brought to the forefront. Methods: Pandoraea pnomenusa M202 was isolated under selection with 8 mg/L polymyxin B from hospital sewage and then was sequenced by the PacBio RS II and Illumina HiSeq 4000 platforms. Mating experiments were performed to evaluate the transfer of the major facilitator superfamily (MFS) transporter in genomic islands (GIs) to Escherichia coli 25DN. The recombinant E. coli strain Mrc-3 harboring MFS transporter encoding gene FKQ53_RS21695 was also constructed. The influence of efflux pump inhibitors (EPIs) on MICs was determined. The mechanism of polymyxin B excretion mediated by FKQ53_RS21695 was investigated by Discovery Studio 2.0 based on homology modeling. Results: The MIC of polymyxin B for the multidrug-resistant bacterial strain P. pnomenusa M202, isolated from hospital sewage, was 96 mg/L. GI-M202a, harboring an MFS transporter-encoding gene and conjugative transfer protein-encoding genes of the type IV secretion system, was identified in P. pnomenusa M202. The mating experiment between M202 and E. coli 25DN reflected the transferability of polymyxin B resistance via GI-M202a. EPI and heterogeneous expression assays also suggested that the MFS transporter gene FKQ53_RS21695 in GI-M202a was responsible for polymyxin B resistance. Molecular docking revealed that the polymyxin B fatty acyl group inserts into the hydrophobic region of the transmembrane core with Pi-alkyl and unfavorable bump interactions, and then polymyxin B rotates around Tyr43 to externally display the peptide group during the efflux process, accompanied by an inward-to-outward conformational change in the MFS transporter...(AU)

Uropathogenic bacteria and deductive genomics towards antimicrobial resistance, virulence, and potential drug targets / Bacterias uropatógenas y genómica deductiva hacia la resistencia, virulencia y posibles objetivos farmacológicos a los antimicrobianos

Urinary tract infections (UTIs) are among the most prevalent bacterial infections affecting people in inpatient and outpatient settings. The current study aimed to sequence the genome of uropathogenic Escherichia coli strain CUI-B1 resourced from a woman having uncomplicated cystitis and pyelonephritis. Followed by deductive genomics towards potential drug targets using E. coli strain CUI-B1, strain O25b: H4-ST131, Proteus mirabilis strain HI4320, Klebsiella pneumoniae strain 1721, and Staphylococcus saprophyticus strain ATCC 15305 uropathogenic strains. Comparative genome analysis revealed that genes related to the survival of E. coli, P. mirabilis, K. pneumoniae, and S. saprophyticus, such as genes of metal-requiring proteins, defense-associated genes, and genes associated with general physiology, were found to be highly conserved in the genomes including strain CUI-B1. However, the genes responsible for virulence and drug resistance, mainly those that are involved in bacterial secretion, fimbriae, adherence, and colonization, were found in various genomic regions and varied from one species to another or within the same species. Based on the genome sequence, virulence, and antimicrobial-resistant gene dataset, the subtractive proteomics approach revealed 22 proteins mapped to the pathogen’s unique pathways and among them, entB, clbH, chuV, and ybtS were supposed to be potential drug targets and the single drug could be utilized for all above-mentioned strains. These results may provide the foundation for the optimal target for future discovery of drugs for E. coli-, P. mirabilis-, K. pneumoniae-, and S. saprophyticus-based infections and could be investigated further to employ in personalized drug development.(AU)

Evaluation of antimicrobial activity of kefir drink against escherichia coli, salmonella typhimurium and shigella flexneri / Evaluación de la actividad antimicrobiana de la bebida de kéfir contra escherichia coli, salmonella typhimurium y shigella flexneri

Objetivo: Evaluar la actividad antimicrobiana de la bebida de Kéfir contra Escherichia coli, Salmonella typhimurium y Shigella flexneri. Método: El kéfir utilizado en la investigación fue adquirido en Toluca, Estado de México. Se realizó una reactivación del kéfir con leche pasteurizada y se analizaron 3 carbohidratos (miel, azúcar y piloncillo) en diferentes concentraciones y tiempos, 80, 100, 120% y 24, 48 y 72 horas respectivamente. Los microorganismos cultivables aislados se caracterizaron por técnicas fenotípicas, bioquímicas y de espectroscopia de masas. El pH inicial y final se determinaron durante el tiempo de estudio. La actividad antimicrobiana se realizó extrayendo los metabolitos presentes en el fermento con el método de Kirby-Bauer, además se evaluó el fermento directo, para determinar si hubo inhibición con las cepas de Escherichia coli ATCC 11229, Salmonella typhimurium ATCC 14028 y Shigella flexneri ATCC 12022. Resultados: Se observó que en los tres carbohidratos utilizados a una concentración de 120% y en un tiempo de 72 h, fue donde se obtuvo un pH menor (3,51 a 3,64) comparado con su concentración inicial (6,50 a 6,64). A partir de los metabolitos extraídos en los diferentes fermentos, no se obtuvo halo de inhibición con las cepas analizadas. Sin embargo, al usar fermentos directos, se observó que en los carbohidratos utilizados (azúcar, miel, piloncillo) existía la presencia de un halo de inhibición o el crecimiento de colonias distintas de las evaluadas. Los microorganismos cultivables aislados fueron: Pichia kudriavzevii (levadura); Enterococcus sp (coco grampositivo) y Lactobacillus sp (bacilo grampositivo). Conclusiones: Los fermentos de kéfir hechos con diferentes carbohidratos, llegaron a presentar un grado de inhibición solo como un consorcio contra microorganismos Gram-negativos analizados.Palabras Clave: Kéfir; fermentación microbiota; infección; actividad antimicrobiana.(AU)

Objective: Evaluate the antimicrobial activity of the Kefir drink against Escherichia coli, Salmonella typhimurium and Shigella flexneri. Method: The Kefir used in the investigation was acquired in Toluca, State of Mexico. We performed a reactivation of Kefir with pasteurized milk and analyzed 3 carbohydrates (honey, sugar and piloncillo) at different concentrations and times, 80, 100, 120% and 24, 48 and 72 hours respectively. Isolated cultivable microorganisms were characterized by phenotypic, biochemical and mass spectroscopy techniques. The initial and final pH were determined during the study time. The antimicrobial activity was carried out by extracting the metabolites present in the ferment with the Kirby-Bauer method, in addition the direct ferment was evaluated, to determine if there was inhibition with the Escherichia coli (ATCC 11229) strains, Salmonella typhimurium (ATCC 14028) and Shigella flexneri (ATCC 12022). Results: It was observed that in the three carbohydrates used at a concentration of 120% and at a time of 72 h, a lower pH was obtained (3.51 to 3.64) compared to their initial concentration (6.50 to 6.64). From the metabolites extracted in the different ferments, no inhibition halo was obtained with the strains analyzed. However, when using direct ferments, it was observed that in the carbohydrates used (sugar, honey, piloncillo) there was the presence of an inhibiting halo or the growth of colonies other than those evaluated. The isolated cultivable microorganisms were: Pichia kudriavzevii (yeast); Enterococcus sp (gram-positive coconut) and Lactobacillus sp (gram-positive bacillus). Conclusions : Kefir ferments made with different carbohydrates, came to present a degree of inhibition only as a consortium against Gram-negative microorganisms analyzed.(AU)

Antimicrobial resistance and molecular epidemiology of carbapenem-resistant Escherichia coli from urinary tract infections in Shandong, China / Resistencia a los antimicrobianos y epidemiología molecular de Escherichia coli resistente a carbapenémicos procedente de infecciones del tracto urinario en Shandong, China

Objectives: Urinary tract infection (UTI) is one of the most common extraintestinal infections, and uropathogenic Escherichia coli (UPEC) is the main cause of UTIs. However, the ability to treat UTI has been compromised by the increase in antimicrobial resistance, especially carbapenem resistance. Here, we aimed to characterize the antimicrobial resistance and molecular epidemiology of carbapenem-resistant UPEC isolated in Shandong, China. Methods: In total, 17 carbapenem-resistant UPEC (CR-UPEC) isolates were collected from July 2017 to May 2020 in the Shandong Provincial Hospital. Whole-genome sequencing and bioinformatics analyses were performed to understand the molecular epidemiology of CR-UPEC. Phylogenetic groups, drug resistance genes, biofilm formation, and virulence-related gene profiles of the isolates were analyzed. Plasmid profiling and conjugation assay were performed to evaluate the ability to transfer carbapenem resistance-related genes to other E. coli isolates. Biofilm formation was also evaluated, as it is important for the persistence of infectious diseases. Results: We observed that 15 out of 17 CR-UPEC strains were blaNDM producers, among which 4 isolates could transfer blaNDM to recipient cells. The predominant sequence type was ST167 (6/17), followed by ST410 (3/17). The most prevalent phylogenetic group was phylogenetic group A (10/17), followed by phylogenetic group C (3/17). One isolate was resistant to polymyxin, which was caused by the carriage of a transferable plasmid harboring mcr-1. Statistical analysis did not reveal any significant difference in the carriage rate of fimbriae-coding genes between strong and weak biofilm producers. Conclusions: Our observations may assist in developing new therapeutic methods for drug-resistant organisms.(AU)

New paradigms on antibiotic recommendations for community-acquired infections in Spain / Nuevos paradigmas en las recomendaciones antibióticas en las infecciones comunitarias en España

Over the last years, the susceptibility activity of the most common microorganisms causing community-acquired infections has significantly changed in Spain. Based on the susceptibility rates of Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli, and Klebsiella pneumoniae collected from outpatients aged 15 or older with symptoms of respiratory or urinary tract infections in several Microbiology Departments in Catalonia in 2021, penicillin V should be first choice for most respiratory tract infections, amoxicillin and clavulanate for chronic obstructive pulmonary disease exacerbations and a single dose of fosfomycin or a short-course nitrofurantoin should remain first-line treatments for uncomplicated urinary tract infections. Updated information on antimicrobial resistance for general practitioners is crucial for achieving appropriate empirical management of the most common infections by promoting more rational antibiotic use.(AU)

En los últimos años han cambiado significativamente los porcentajes de sensibilidad de los microorganismos más comunes que causan infecciones adquiridas en la comunidad en España. A partir de los porcentajes de sensibilidad de Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, Escherichia coli y Klebsiella pneumoniae, recogidas de aislados de pacientes ambulatorios de 15 años o más, con síntomas de infecciones respiratorias o urinarias en servicios de microbiología de Cataluña en 2021, fenoximetilpenicilina debería ser la primera opción en la mayoría de los infecciones respiratorias, amoxicilina y ácido clavulánico en las exacerbaciones de la enfermedad pulmonar obstructiva crónica y la monodosis de fosfomicina o la pauta corta de nitrofurantoína como tratamiento de primera línea en las infecciones urinarias no complicadas. Es importante que los médicos de familia dispongan de información actualizada sobre la resistencia a los antimicrobianos para lograr un manejo empírico adecuado de las infecciones más frecuentes al promover un uso más racional de los antibióticos.(AU)

Diverse infective and lytic machineries identified in genome analysis of tailed coliphages against broad spectrum multidrug-resistant Escherichia coli / Diversas maquinarias infecciosas y líticas identificadas en el análisis del genoma de colifagos con cola contra Escherichia coli multirresistente de amplio espectro

The emergence of multidrug-resistant (MDR) E. coli with deleterious consequences to the health of humans and animals has been attributed to the inappropriate use of antibiotics. Without effective antimicrobials, the success of modern medicine in treating infections would be at an increased risk. Bacteriophages could be used as an alternative to antibiotics for controlling the dissemination of MDR bacteria. However, before their use, the bacteriophages have to be assessed for the safety aspect. In this study, three broad host range highly virulent coliphage genomes were sequenced, characterized for infective and lytic potential, and checked for the presence of virulence and resistance genes. The genome sequencing indicated that coliphages ϕEC-S-21 and ϕEC-OE-11 belonged to Myoviridae, whereas coliphage ϕEC-S-24 belonged to the Autographiviridae family derived from the Podoviridae family. The genome size of the three coliphages ranged between 24 and 145 kb, with G + C content ranging between 37 and 51%. Coding sequences (CDS) ranged between 30 and 251 amino acids. The CDS were annotated and the proteins were categorized into different modules, viz., phage structural proteins, proteins associated with DNA replication, DNA modification, bacterial cell lysis, phage packaging, and uncharacterized proteins. The presence of tRNAs was detected only in coliphage ϕEC-OE-11. All three coliphages possessed diverse infective and lytic mechanisms, viz., lytic murein transglycosylase, peptidoglycan transglycosylase, n-acetylmuramoyl-l-alanine amidase, and putative lysozyme. Furthermore, the three coliphage genomes showed neither the presence of antibiotic resistance genes nor virulence genes, which makes them desirable candidates for use in phage therapy-based applications.(AU)

Evolution of Antibiotic Resistance in Escherichia coli and Klebsiella pneumoniae from Urine Cultures

Objective: Determine the evolution of antibiotic resistance of symptomatic bacteriuria caused by Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) in Granada. Material and Method: A descriptive retrospective study was carried out, including antibiograms of urine cultures in which microorganisms identified as E. coli and K. pneumoniae, were isolated in the Microbiology laboratory of the Hospital Universitario Virgen de las Nieves (Granada, Spain) between January 2016 and June 2021. Results: E. coli was the most frequent isolate (10,048) and its resistance to ampicillin (59.45%) and ticarcillin (59.59%), and the increase to cefepime (15.07%) and amoxicillin-clavulanic acid (17.67%) is noteworthy. K. pneumoniae (2222) is notable for resistance to Fosfomycin (27.91%) and an increase to ciprofloxacin (37.79%) and amoxicillin-clavulanic acid (36.63%). Resistance is generally higher in hospitalized patients, males, and adults. Conclusions: Antibiotic resistance to the studied Enterobacteriaceae is on the rise, requiring empirical treatment targeted to the population area (AU)

Infecciones del tracto urinario en personas mayores: etiología y susceptibilidades antimicrobianas en un área del sur de España / Urinary tract infections in older adults: Etiology and antimicrobial susceptibilities in a southern area of Spain

Introducción: La infección del tracto urinario (ITU) es una de las enfermedades más prevalentes en la práctica clínica y aumenta en pacientes mayores de 65años en comparación con pacientes de mediana edad. Con el fin de mejorar el tratamiento empírico se ha estudiado la etiología y el perfil de sensibilidad antibiótica de las bacterias más frecuentes productoras de ITU en personas mayores. Material y métodos: Estudio transversal, descriptivo y retrospectivo en el que se incluyeron los microorganismos aislados con recuento significativo en muestras de orina de pacientes con ITU. Se analizó la etiología global y en función del sexo. Se consideró únicamente una muestra de orina por paciente y episodio de ITU. Resultados: Respecto a la procedencia de la muestra, la mayor proporción fue en atención primaria, con 4.853 urocultivos (51,6% de urocultivos positivos), seguido de atención hospitalaria, con 3.565 urocultivos (46,4% de urocultivos positivos) y 94 urocultivos en las residencias de ancianos (2% de urocultivos positivos). Escherichia coli fue el microorganismo más aislado tanto en el conjunto de la población (54%) como en cada uno de los grupos analizados. Se observó que E.coli aislado en mujeres fue significativamente superior que en hombres (χ2, p=0,044). Su sensibilidad fue: fosfomicina 80% y 75% amoxicilina-ácido clavulánico. Conclusiones: E.coli continúa siendo el microorganismo más frecuentemente aislado en ITU. El tratamiento empírico de las ITU en nuestro medio debería incluir fosfomicina o amoxicilina-ácido clavulánico, independientemente de la unidad de atención sanitaria y del sexo. (AU)

Introduction: Urinary tract infection (UTI) is one of the most prevalent diseases in clinical practice and increases in patients older than 65years compared to middle-aged patients. In order to improve empirical treatment, the etiology and antibiotic sensitivity profile of the most frequent bacteria that produce UTIs in older people have been studied. Material and methods: Cross-sectional, descriptive and retrospective study in which isolated micro-organisms with significant counts in urine samples from patients with UTI were included. The global etiology and according to sex were analyzed. Only one urine sample per patient and UTI episode was considered. Results: Regarding the origin of the sample, the highest proportion was in primary care with 4853 urine cultures (51.6% of positive urine cultures), followed by hospital care with 3565 urine cultures (46.4% of positive urine cultures) and 94 urine cultures in nursing homes elderly (2% positive urine cultures). Escherichia coli was the most isolated micro-organism both in the population as a whole (54%) and in each of the analyzed groups. It was observed that E.coli isolated in women was significantly higher than in men (χ2, P=.044). Their sensitivity was: 80% fosfomycin and 75% amoxicillin-clavulanic acid. Conclusions: E.coli continues to be the most frequently isolated micro-organism in UTI. Empirical treatment of UTI in our environment should include fosfomycin or amoxicillin-clavulanic acid, regardless of the health care unit and gender. (AU)

A study on the antibacterial activity and antimicrobial resistance of pyridinium cationic pillar[5]arene against Staphylococcus aureus and Escherichia coli / Un estudio sobre la actividad antibacteriana y la resistencia antimicrobiana del pilar catiónico de piridinio[5]areno contra Staphylococcus aureus y Escherichia coli

An increasing number of infections caused by multidrug-resistant (MDR) Staphylococcus aureus （S. aureus） and Escherichia coli （E. coli） have severely affected human society. Thus, it is essential to develop an alternative type of antibacterial agents that has a different bacterial resistance mechanism from that of traditional antibiotics. After the synthesis and structural characterization of a cationic pillar[5]arene with pyridinium groups (PP5), the antibacterial and antibiofilm activities as well as its microbial resistance were systematically investigated. In-depth evaluation of biological studies revealed that PP5 was an active antibacterial agent, with surprising antibiofilm formation ability against E. coli and S. aureus. From the results of differential scanning calorimetry and transmission electron microscopy, it was concluded that the microbicidal activity of PP5 was due to the physical disruption of the pathogen’s membrane and the subsequent leakage of cytoplasmic components, which could greatly reduce the rapid generation of resistance. It was presented that the easily available PP5 has high activity to inhibit Gram-positive and Gram-negative bacteria and/or their biofilms with low cytotoxicity. This pillar[5]arene derivative can be used as a good candidate for controlling drug-resistant pathogenic bacterial infections and treating MDR bacteria.(AU)

Evaluación de la calidad microbiológica del queso de hoja tradicional de Ecuador elaborado artesanal e industrialmente / Evaluation of the microbiological quality of traditional leafcheese in Ecuador both handcrafted and industrially produced

Uno de los quesos frescos tradicionales típicos del Ecuador es el queso de hoja, un queso de pasta hilada, que se elabora de manera artesanal envuelto en hoja de achira (Canna indica), mientras en la industria es empacado al vacío en bolsas de polietileno. En el presente estudio se comparó la calidad microbiológica de estos quesos, evaluando los indicadores de la calidad higiénico-sanitaria, además se cuantificaron y caracterizaron fenotípicamente bacterias ácido lácticas (BAL). Las muestras se recolectaron en queseras artesanales y plantas industriales de la ciudad de Latacunga. Se determinaron recuentos de aerobios mesófilos aplicando la Norma Técnica Ecuatoriana NTE INEN 1529 5, coliformes totales, Escherichia coli y Staphylococcus aureus se analizaron utilizando placas Petrifilm (AOAC 991.14 – AOAC 2003.07). El recuento de bacterias ácido lácticas empleó el método PRT-712.02-047. Los resultados de los indicadores de la calidad higiénico-sanitaria: coliformes, E. coli y S. aureus examinados en los quesos de hoja artesanales y de elaboración industrial, en todos los casos superaron los límites de aceptabilidad establecidos por la normativa ecuatoriana, sugiriendo deficiente calidad higiénica de los procesos o incorrecta manipulación de la leche empleada como materia prima. (AU)

One of the traditional fresh cheeses in Ecuador is the artisanal leafcheese, a kind of stretched-curd cheese. The artisanal product is wrapped in achira leaves (Canna indica), while the industrial leafcheese is packed at vacuum in high density polyethylene bags. In this study the microbiological quality of both products was compared. The hygienic-sanitary microbial indicators and lactic acid bacteria (LAB) were quantified. The LAB isolated were characterized phenotypically. The samples were obtained from artisanal cheese-making and industrial located in Latacunga city province Cotopaxi.The total aerobic mesophilic count was made based on national regulations (NTE INEN 1529 5); total coliforms, Escherichia coli and Staphylococcus aureus was evaluated using petrifilm methods (AOAC 991.14 – AOAC 2003.07) and to LAB was used PRT-712.02-047. The results show high quantities of total coliforms, E. coli and S. aureus in both products, these data exceed the limits of acceptability established in Ecuadorian regulations, this evidence poor hygienic quality of the processes or incorrect controls of milk as raw material. (AU)

Infection with a human-derived enteroinvasive Escherichia coli strain altered intestinal barrier function in guinea pigs / La infección con una cepa enteroinvasiva de Escherichia coli de origen humano alteró la función de la barrera intestinal en cobayos

Background/aims: The aim was to characterize a bacterium causing intestinal mucosal barrier damage and to identify the possible invasion mechanism. Materials and methods: The intestinal permeability and tight junction protein levels were detected in guinea pigs infected with Escherichia coli D-09 via immunofluorescence analysis and western blotting. In order to explain this invasion mechanism at the gene level, whole genome sequencing analysis was performed on this bacterium. Results: The results showed an increased intestinal permeability and upregulated expression of the leaky protein claudin-2 in both the colon and liver of the infected animals. In addition, the draft genome of E. coli D-09 comprised 42 scaffolds (size, > 645 bp) with a total size of 4,679,567 bp. A total of 4379 protein coding genes were identified, which contained 45 antibiotic resistance and 86 virulence-related genes and covered 88.0% of the whole genome. Conclusions: This study verified that the human-derived enteroinvasive E. coli strain could destroy intestinal barrier function in guinea pigs. Additionally, our data first characterized the genome features of E. coli O124:K72 D-09, which may provide new insights into the possible invasion mechanism.(AU)

A one health approach versus Acanthamoeba castellanii, a potential host for Morganella morganii / Un enfoque de salud único versus Acanthamoeba castellanii, un huésped potencial de Morganella morganii

Acanthamoeba castellanii, known as the “Trojan horse of the microbial world,” is known to host a variety of microorganisms including viruses, yeasts, protists, and bacteria. Acanthamoeba can act as a vector and may aid in the transmission of various bacterial pathogens to potential hosts and are found in a variety of places, thus impacting the health of humans, animals, and the environment. These are interconnected in a system known as “one health.” With the global threat of antibiotic resistance, bacteria may avoid harsh conditions, antibiotics, and disinfectants by sheltering within Acanthamoeba. In this study, Acanthamoeba castellanii interaction with Morganella morganii, a Gram-negative bacterium was studied. Escherichia coli K1 interaction with Acanthamoeba was carried out as a control. Association, invasion, and survival assays were accomplished. Morganella morganii was found to associate, invade, and survive within Acanthamoeba castellanii. Additionally, Escherichia coli K1 was also found to associate, invade, and survive within the Acanthamoeba at a higher number in comparison to Morganella morganii. For the first time, we have shown that Morganella morganii interact, invade, and survive within Acanthamoeba castellanii, suggesting that Acanthamoeba may be a potential vector in the transmission of Morganella morganii to susceptible hosts. Taking a one health approach to tackle and develop disinfectants to target Acanthamoeba is warranted, as the amoebae may be hosting various microbes such as multiple drug-resistant bacteria and even viruses such as the novel coronavirus.(AU)

Genetic diversity and virulence characteristics of biofilm-producing uropathogenic Escherichia coli / Diversidad genética y características de virulencia de Escherichia coli uropatógena productora de biopelículas

Uropathogenic E. coli (UPEC) strains exhibit different levels of biofilm formation that help adhesion of the bacteria to uroepithelial cells. We investigated the genetic diversity and virulence-associated genes (VAGs) of biofilm-producing UPEC. A collection of 107 biofilm-producing (BFP) UPEC strains isolated from patients with UTI in Iran were divided into three groups of strong, moderate, and weak BFPs after a quantitative microtiter plate assay, and the involvement of curli and cellulose in adhesion of the strains to T24 cell line was confirmed by the construction of csgD and yedQ mutants of two representative UPEC strains. BFP strains were tested for their genetic diversity, phylogenetic groups, and the presence of 15 VAGs. A significant decrease in adhesion of csgD and yedQ mutant strains confirmed the role of biofilm production in adhesion to uroepithelial cells. A high diversity was found among all three groups of strong (Di = 0.998), moderate (Di = 0.998), and weak (Di = 0.988) BFPs with majority of the strains belonging to phylogroups B2 (44.9%) and A (24.3%). Strong BFP strains carried significantly higher level papEF, hlyA, and iutA than other BFP groups. In contrast, the presence of fimH, focG, sfaS, set-1, and cvaC was more pronounced among weak BFP strains. There exists a high genetic diversity among the BFP strains with different VGA profiles. However, the high prevalence of phylogroup A among BFP strains suggests the fitness of commensal E. coli strains to cause UTI in this country.(AU)

Síndrome de Stüve-Wiedemann remedando una sepsis neonatal / Stüve-Wiedemann syndrom mimicking neonatal sepsis

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