Search Results (137)

Background/Objectives: Increasing levels of antimicrobial resistance (AMR) have recently been observed at the human–domestic animal–wildlife interface. Wild birds have been identified as carriers of antimicrobial-resistant bacteria and serve as excellent biomarkers for epidemiological studies. This study assessed the current AMR presence in Eastern Spain’s commensal Escherichia coli isolated from free-ranging Bonelli’s eagles (Aquila fasciata). Methods: Nestlings and their nests were intensively sampled between 2022 and 2024 to determine their AMR profile and characterize E. coli. AMR testing was conducted using the broth microdilution method, following the European Committee on Antimicrobial Susceptibility Testing guidelines. Additionally, the presence of eaeA (intimin gene) and stx-1 and stx-2 (shiga toxins) was analyzed by real-time PCR to classify E. coli strains into enteropathogenic (EPEC) and Shiga-toxigenic (STEC) pathotypes. Results: Of all E. coli isolates, 41.7% were resistant to at least one antimicrobial, and 30% were multidrug-resistant. Only two strains were classified as EPEC and none as STEC. The highest resistance rates were observed for amoxicillin and tetracycline (19.6% each). Alarmingly, resistance to colistin and meropenem, last-resort antibiotics in human medicine, was also detected. Conclusions: Although the mechanisms of resistance acquisition remain unclear, transmission is likely to occur through the food chain, with synanthropic prey acting as intermediary vectors. These results highlight the role of Bonelli’s eagles as essential sentinels of environmental AMR dissemination, even in remote ecosystems. Strengthening One Health-based surveillance is necessary to address AMR’s ecological and public health risks in wildlife. Full article

This study identified 13 endoplasmic reticulum stress (ERS)-related biomarkers associated with multiple sclerosis (MS) through integrated bioinformatics analysis (including weighted gene co-expression network analysis and machine learning algorithms) and single-cell sequencing, combined with validation in an experimental autoimmune encephalomyelitis (EAE) mouse model. Among them, GPX1, RCN1, and UBE2D3 exhibited high diagnostic value (AUC > 0.7, p < 0.05), and the diagnostic potential of GPX1 and RCN1 was confirmed in the animal model. The study found that memory B cells, plasma cells, neutrophils, and M1 macrophages were significantly increased in MS patients, while naive B cells and activated NK cells decreased. Consensus clustering based on key ERS-related genes divided MS patients into two subtypes. Single-cell sequencing showed that microglia and pericytes were the cell types with the highest expression of key ERS-related genes, and the APP-CD74 pathway was enhanced in the brain tissue of MS patients. Mendelian randomization analysis suggested that GPX1 plays a protective role in MS. These findings reveal the mechanisms of ERS-related biomarkers in MS and provide potential targets for diagnosis and treatment. Full article

Escherichia albertii is a lactose-negative Escherichia that causes gastritis and enteritis in humans. An analysis of possible sources of infection points out that poultry may be a significant reservoir for this pathogen. The question of whether E. albertii can cause infections in poultry is still unanswered. Our article describes the isolation of E. albertii, for the first time in Russia, from the intestines of birds on a quail farm and a characterization of obtained cultures. We isolated different bacteria from pathological poultry material using bacteriological methods and ruled them out as probable causes for enteritis. The biochemical identification of E. albertii and antibiotic sensitivity were performed using a Vitek-2 Compact instrument. Bacterial identification was carried out using the MALDI-TOF Biotyper instrument. E. albertii-specific genes, virulence factor genes, and microcin genes were detected by real-time PCR. It was concluded that E. albertii isolated from sites of intestinal inflammation are a potential cause of enteritis and high poultry mortality—up to 15% of total livestock for 10- to 20-day-old quails. One of the E. albertii culture differed from the main group of Escherichia by its biochemical properties, and subsequent PCR analysis showed a lack of the intimin gene (eae). We describe the first occasion of infection caused by E. albertii in industrial quails. During the study, it was found that, according to the molecular–genetic and phenotypic properties of isolated strains in quails, there were at least two clonal groups of E. albertii differing in antibiotic resistance, biochemical indices, and presence of the eae (intimin) gene. Full article

Escherichia coli (E. coli) has the ability to induce clinical and subclinical mastitis in dairy cows, causing a huge loss for the dairy industry. In this study, 51 subclinical mastitis isolates and 36 clinical mastitis isolates from eight provinces of China between 2019 and 2021 were used to investigate the differences in their biological characteristics. The results showed that B1 (52.9%) and A (39.1%) were the predominant phylogroups; R1 (50.6%) was the predominant lipopolysaccharide (LPS) core type; and 44 STs (ST10 and ST58 were the most sequence-prevalent STs) and 2 new STs (ST14828 and ST14829) were identified; however, no significant difference was observed between the clinical and subclinical group strains. To compare the virulence gene differences between the clinical and subclinical mastitis-related isolates, 18 common virulence genes (including afaE, eaeA, papC, saa, sfa, ompA, aer, irp2, iucD, escV, sepD, east1, estB, stx2e, CNF1, cba, hlyA and traT) were determined using the PCR method. The results showed that the detection rates of traT, irp2 and iucD in clinical mastitis isolates were significantly higher than those in subclinical mastitis isolates (p ˂ 0.05). Meanwhile, subclinical-group E. coli had stronger biofilm formation abilities than the clinical group (p < 0.05) in 78 (89.7%) mastitis-related E. coli that could form biofilms. Furthermore, 87 mastitis-related E. coli showed severe resistance against tetracycline (37.9%), ampicillin (36.8%), streptomycin (34.5%) and cotrimoxazole (28.7%); their most prevalent resistance genes were blaCTX-M (33.3%), tetA (27.6%), sul2 (18.4%) and strB (28.7%). It was noteworthy that the clinical-group strains had a higher resistance against ampicillin and possessed higher amounts of the resistance gene blaCTX-M (p < 0.05) compared to the subclinical group. This study aims to provide references for preventing the E. coli isolates from inducing different types of mastitis. Full article

Gapmer-type antisense oligonucleotides (ASOs) are an emerging class of therapeutic agents that directly inhibit pathogenic mRNA. In this study, three new 4′-C-substituted thymidine analogs were generated using a synthetic strategy recently established by our group, namely, 4′-C-(N-ethyl) aminoethyl (4′-EAE-T), 4′-C-(N-butyl) aminoethyl (4′-BAE-T), and 4′-C-(N-octyl) aminoethyl (4′-OAE-T). Their properties were evaluated and compared with those of previously reported analogs, including 4′-C-aminoethyl (4′-AE-T) and 4′-C-(N-methyl) aminoethyl (4′-MAE-T). The novel nucleoside analogs were subsequently incorporated into gapmer-type ASOs featuring phosphorothioate (PS) linkages and locked nucleic acids (LNAs) in the wing regions. The incorporation of 4′-EAE-T and 4′-BAE-T analogs resulted in RNA binding affinities similar to that of the previously reported 4′-MAE-T analog, whereas a marked decrease in RNA affinity was noted for 4′-OAE-T, however, this reduction was mitigated when combined with other chemical modifications. Furthermore, the structural modifications conferred enhanced nuclease resistance under bovine serum conditions, with 4′-EAE-T resulting in the highest stability, followed by 4′-BAE-T and 4′-OAE-T. Additionally, oligonucleotides modified with the developed analogs preserved their RNase H cleavage susceptibility, albeit inducing minor alterations in the cleavage pattern. Finally, the oligonucleotides were applied in a gene silencing experiment targeting the KRAS gene, conducted without the use of transfection agents, displaying gene silencing activities comparable to that of the control, with the exception of the 4′-OAE-modified nucleotide, which exhibited low activity. Full article

This study aims to investigate the prevalence of E. coli and E. coli O157:H7 in 353 samples collected in Kirkuk from human stool, animal feces, raw and pasteurized milk, and beef hamburgers. E. coli was isolated using conventional methods and identified with the Enterosystem Kit 18R. Suspected E. coli O157:H7 were confirmed serologically and tested for antimicrobial resistance and virulence genes (stx1, stx2, eaeA, and hlyA). The overall prevalence rates of 20.4% for E. coli and 7.9% for E. coli O157:H7 were found, with the highest prevalence in human stool. The antimicrobial susceptibility profile of 28 E. coli O157:H7 isolates revealed significant resistance and sensitivity patterns, highlighting important implications for public health. The isolates demonstrated complete sensitivity to gentamicin (100%), while also showing high sensitivity to ciprofloxacin (92.86%), ceftriaxone (85.71%), and amikacin (64.29%). Conversely, the isolates exhibited notable resistance to tetracycline (85.71%), ampicillin (75.00%), sulfamethoxazole (71.43%), and streptomycin (67.86%). All the E. coli O157:H7 strains isolated in this study were positive for stx1 and/or stx2, as well as the eaeA gene, and are referred to as enterohemorrhagic (EHEC) strains. In order to highlight the genotypic variability among the EHEC E. coli O157:H7 isolates, five virulence profiles were identified, with profile III (stx2, eaeA, and hlyA) being the most common (35.7%). This profile was closely associated with diarrheic humans, while profile V (stx1, eaeA) was prevalent in animal feces and products. These findings may raise awareness of the risks associated with this pathogen, helping to reduce the incidence of E. coli-related diseases and to protect human health. Full article

Background/Objectives: Centella asiatica (L.) Urban (family Apiaceae) (C. asiatica) is a traditional botanical medicine used in aging and dementia. Water extracts of C. asiatica (CAW) have been used to treat neuropsychiatric symptoms in related animal models and are associated with increases in antioxidant response element (ARE) genes and improvements in mitochondrial respiratory function and neuronal health. Because multiple sclerosis (MS) shares its neurogenerative pathology of oxidative stress and mitochondrial dysfunction with aging and dementia, neuropsychiatric symptoms in MS may also benefit from C. asiatica. To determine whether CAW similarly benefits neuropsychiatric symptoms, ARE gene expression, and mitochondrial respiration in inflammatory models of MS, and to determine the effects of CAW on clinical disability and inflammation, we tested CAW using experimental autoimmune encephalomyelitis (EAE). Methods: C57BL/6J mice induced with EAE were treated with CAW or a placebo for 2 weeks. The outcomes were clinical disability, signs of anxiety (open field test), ARE gene expression, mitochondrial respiration, and inflammation and demyelination. Results: At the dosing schedule and concentrations tested, CAW-treated mice with EAE demonstrated increased ARE gene expression and mitochondrial respiratory activity compared to those of placebo-treated mice with EAE. CAW was also associated with reduced inflammatory infiltrates in the spinal cord, but the differences between the populations of activated versus quiescent microglia were equivocal. CAW did not improve behavioral performance, EAE motor disability, or demyelination. Conclusions: In the inflammatory EAE model of MS, CAW demonstrates similar neuroprotective effects to those it exhibits in aging and dementia mouse models. These benefits, along with the anti-inflammatory effects of CAW, support further investigation of its neuropsychiatric effects in people with MS. Full article

Two distinct stx_2f-carrying Escherichia coli (E. coli) strains, isolated from a child with uncomplicated diarrhea fifteen weeks apart, were characterized by combining short- and long-read sequencing to compare their genetic relatedness. One strain was characterized as Shiga toxin-producing E. coli (STEC)/typical enteropathogenic E. coli (tEPEC) O63:H6 with a repertoire of virulence genes including stx_2f, eae (α2-subtype), cdt, and bfpA. The other STEC with serotype O157:H16, reported for the first time as stx_2f-carrying Escherichia coli in this study, possessed, in addition, eae (ε-subtype) and cdt, amongst other virulence-related genes. BLAST comparison showed that the stx_2f-harboring prophage sequences of both strains were highly homologous (99.6% identity and 96.1% coverage). These results were corroborated by core Stx2f phage Multilocus Sequence Typing (cpMLST) as the stx_2f-harboring prophages of both isolates clustered together when compared to those of 167 other human stx_2f-carrying Escherichia coli. Overall, the stx_2f-harboring prophages of the two distinct E. coli strains isolated from the present case were highly similar, suggesting that the stx_2f-harboring phage might have been transferred from the STEC/tEPEC O63:H6 strain to the atypical EPEC (aEPEC) O157:H16 strain in the gut of the child. Full article

Seagulls are synanthropic wild birds that can contaminate, through their droppings, beaches, urban and peri-urban environments. This concern is more serious when seagulls eliminate antimicrobial-resistant pathogenic bacteria. This study analyzed the fecal samples from 137 yellow-legged seagulls (Larus michahellis) from Central Italy. A total of 218 Escherichia coli strains were isolated and analyzed for phenotypic and genotypic antimicrobial resistance and to identify the virulence genes characterizing different pathotypes. The disk diffusion method on all isolates found relevant resistance rates to ampicillin (38.99%), tetracycline (23.85%), and enrofloxacin (21.10%). On the basis of all results obtained with this test, 62 (28.44%) isolates were classified as multidrug-resistant (MDR) and 6 (2.75%) as extensive drug-resistant (XDR). Molecular analyses conducted on the strains phenotypically resistant to carbapenems, cephalosporins, and penicillins found 9/37 (24.32%) strains positive for bla_OXA-48, 52/103 (50.49%) for bla_TEM, 12/103 (11.65%) for bla_CMY2, 3/103 (2.91%) for bla_CTX, and 1/103 (0.97%,) for bla_SHV. PCR to detect virulence genes characterizing different pathotypes found that 40 (18.35%) isolates had the astA gene, indicative of the enteroaggregative (EAEC) pathotype, 2 (0.92%) had cnf1, 2 (0.92%) had cnf2, and 1 (0.46%) had cdt-IV. All five (2.29%) strains were reportable as necrotoxigenic (NTEC), while 4 (1.83%) had both eaeA and escV, reportable as enteropathogenic (EPEC). Measures to limit seagulls’ access where humans and other animals reside are pivotal to reduce the risk of infection with antimicrobial-resistant and pathogenetic E. coli strains. Full article

CD4+ T cells are considered the main orchestrators of autoimmune diseases. Their disruptive effect on CD4+ T cell differentiation and the imbalance between T helper cell populations can be most accurately determined using experimental autoimmune encephalomyelitis (EAE) as an animal model of multiple sclerosis (MS). One epigenetic factor known to promote autoimmune inflammation is miRNA-155 (miR-155), which is significantly upregulated in inflammatory T cells. The aim of the present study was to profile the transcriptome of immunized mice and determine their gene expression levels based on mRNA and miRNA sequencing. No statistically significant differences in miRNA profile were observed; however, substantial changes in gene expression between miRNA-155 knockout (KO) mice and WT were noted. In miR-155 KO mice, mRNA expression in CD4+ T cells changed in response to immunization with the myeloid antigen MOG_35-55. After restimulation with MOG_35-55, increased Ffar1 (free fatty acid receptor 1) and Scg2 (secretogranin-2) expression were noted in the CD4+ T cells of miR-155-deficient mice; this is an example of an alternative response to antigen stimulation. Full article

This study aimed to count Enterobacteriaceae and Escherichia coli in different locations on pig carcasses (shank, loin, abdomen, shoulder, and jowl) from two slaughterhouses (A and B) between September 2019 and July 2021 during different slaughter stages (after bleeding, after passing through the epilator machine, after manual toileting in the dirty area, before and after evisceration, and after the final washing), as well as verify antimicrobial resistance and biofilm formation capacity. The main points of Enterobacteriaceae and E. coli contamination were identified in the two slaughterhouses through three collections. The stages with the highest counts were post-bleeding and evisceration in both slaughterhouses and after manual toileting in slaughterhouse B in the first collection. Most E. coli isolates were resistant to multiple antimicrobials, with higher resistance frequencies to amoxicillin, ampicillin, chloramphenicol, sulfonamides, and streptomycin. The virulence genes eae, stx1, and stx2 were also detected. Three isolates had all three genes and exhibited resistance to at least six antimicrobial classes (β-lactams, macrolides, aminoglycosides, sulfonamides, amphenicols, and quinolones). E. coli isolates also showed a high frequency of strains with moderate and strong in vitro biofilm-forming capacity. This is the first study to characterize microbial contamination by pig slaughter stage in the Federal District region, demonstrating the critical points for hygienic production. E. coli was isolated from the surface of pig carcasses, as well as the virulence genes stx1, stx2, and eae were detected. The multi-antimicrobial resistant isolates also had a moderate-to-strong biofilm formation capacity, thus demonstrating risks to public health. Full article

Multiple sclerosis (MS) is a chronic autoimmune disease with an unknown etiology. The purpose of this research was to assess miR-223, miR-146a, and miR-193a in acute and chronic phases of experimental autoimmune encephalomyelitis (EAE) mice to consider the possible role of these genes in the pathogenesis of MS. EAE induction was given by myelin oligodendrocyte glycoprotein peptide on female C57BL/6 mice. Clinical scores and other criteria were followed daily until day 21 for the acute group and day 77 for the chronic group. At the end of the course, inflammation and demyelination of the central nervous system (CNS) were assessed by histological analysis. MicroRNA expression levels were assessed by real-time PCR. EAE development attenuated in the chronic group, and histological analysis showed less infiltration and demyelination in the chronic group compared to the acute group. The upper expression of miR-223 is demonstrated in the acute phase of EAE. Moreover, the expression levels of miR-146a and miR-193a decreased in the chronic phase of EAE. MiR-223 showed a highly coordinated elevation in the acute phase both in vivo and in vitro. MiR-146a shares a pathway with miR-223 through effecting IL-6 expression. Further studies are needed to reveal their impact on EAE and possible applications as drug targets and biomarkers. Full article

Shiga toxin-producing E. coli (STEC) are considered important zoonotic pathogens of great economic significance, associated with diarrhea, hemolytic uremic syndrome (HUS), hemorrhagic colitis (HC), and death in humans. This study aimed to investigate the distribution of various STEC virulence gene markers and antimicrobial susceptibility (AST) profiles associated within E. coli isolates from the recto-anal mucosal swabs (RAMSs) of slaughtered cattle and buffaloes in Islamabad, Pakistan. The RAMSs (n = 200) were analyzed using multiplex PCR for the presence of stx1, stx2, eae, and ehxA genes. Samples that were positive for one or more of the virulence genes were inoculated with Sorbitol MacConkey agar (SMAC) for isolation of STEC. The isolates were further analyzed for the presence of virulence genes using multiplex PCR. Of the 200 RAMS, 118 (59%) were positive for one or more virulence genes. E. coli isolates (n = 18) with one or more virulence genes were recovered from the 118 positive samples. The DNA of the isolates positive for one or more virulent genes was extracted and subjected to whole genome sequencing using Illumina. Analysis of the WGS data indicated that the E. coli isolates could be differentiated into 11 serotypes. Most E. coli isolates (13/18; 72.2%) carried five genes (stx1, stx2, Iha, iss, and IpfA) in various combinations. In addition to these five genes, other virulence genes identified in these isolates were espI, ireA, espP, exhA, epeA, mcmA, mch, ast, celB, eilA, katP, and capU. The AST was performed using the Kirby–Bauer disk diffusion test. The study indicated that all the isolates were resistant to rifampicin and a significant proportion of the isolates were MDR. A wide range of antimicrobial resistance genes (ARGs) were detected among the isolates, reflecting the complex nature of resistance mechanisms. The study results indicate that cattle and buffaloes slaughtered in Islamabad might be the carriers of antimicrobial resistant STEC of zoonotic significance, thus representing a source of human infection. Full article

Enteropathogenic Escherichia coli (EPEC) are pathogens associated with gastrointestinal illnesses. Dogs and cats can harbor EPEC, and antimicrobial resistance may impair necessary treatments. This study characterized E. coli strains from dogs and cats, focusing on phylogroup classification, virulence factors, and antimicrobial resistance profiles. Ninety-seven E. coli isolates from fecal samples of 31 dogs and 3 cats were obtained from a private diagnostic laboratory in Botucatu, Brazil, from March to October 2021. The antimicrobial susceptibility was assessed using the disk diffusion method. Polymerase chain reaction (PCR) was employed to screen for bla_CTX-M and genes encoding virulence factors, as well as to classify the isolates into phylogroups. Twenty isolates were positive for intimin encoding gene eae and, consequently, these isolates were classified as EPEC (20.62%). Notably, 5.1% (5/97) of the isolates exhibited extended-spectrum β-lactamase (ESBL) production and 13.4% (13/97) were identified as multidrug-resistant bacteria. Phylogroups A and B2 were the most prevalent, comprising 29.9% (29/97) and 26.8% (26/97) of the bacterial isolates, respectively. This characterization highlights the prevalence of EPEC in domestic animals, emphasizing the potential risk they pose to public health and highlighting the urgency of responsible antimicrobial use in veterinary practices and the important role of laboratories in the surveillance of pathogenic multidrug-resistant bacteria. Full article

Contaminations with cephalosporin-resistant Escherichia coli across the food chain may pose a significant threat to public health because those antimicrobials are critically important in human medicine. The impact of the presented data is especially significant concerning Poland’s role as one of the leading food producers in the EU. This work aimed to characterize the genomic contents of cephalosporin-resistant Escherichia coli (n = 36) isolated from retail meat to expand the official AMR monitoring reported by EFSA. The ESBL mechanism was predominant (via bla_CTX-M-1 and bla_SHV-12), with the AmpC-type represented by the bla_CMY-2 variant. The strains harbored multiple resistance genes, mainly conferring resistance to aminoglycosides, sulfonamides, trimethoprim, tetracyclines. In some isolates, virulence factors—including intimin (eae) and its receptor (tir) were detected, indicating significant pathogenic potential. Resistance genes showed a link with IncI1 and IncB/O/K/Z plasmids. Cephalosporinases were particularly linked to ISEc9/ISEc1 (bla_CTX-M-1 and bla_CMY-2). The association of virulence with mobile elements was less common—mostly with IncF plasmids. The analysis of E. coli isolated from retail meat indicates accumulation of ARGs and their association with various mobile genetic elements, thus increasing the potential for the transmission of resistance across the food chain. Full article