Search Results (345)

This study describes the first complete genomic sequence of an NDM-19 and QnrS11-producing multidrug-resistant (MDR) Escherichia coli isolate collected from a fecal swab from a poultry farm in 2019 in Egypt. The bla_NDM-19 was identified by PCR screening and DNA sequencing. The isolate was then subjected to antimicrobial susceptibility testing, conjugation and transformation experiments, and complete genome sequencing. The chromosome of strain M2-13-1 measures 4,738,278 bp and encodes 4557 predicted genes, with an average G + C content of 50.8%. M2-13-1 is classified under ST167, serotype O101:H5, phylogroup A, and shows an MDR phenotype, having minimum inhibitory concentrations (MICs) of 64 mg/L for both meropenem and doripenem. The genes bla_NDM-19 and qnrS11 are present on 49,816 bp IncX3 and 113,285 bp IncFII: IncFIB plasmids, respectively. M2-13-1 harbors genes that impart resistance to sulfonamides (sul1), trimethoprim (dfrA14), β-lactams (bla_TEM-1B), aminoglycosides (aph(6)-Id, aph(3′)-Ia, aph(3″)-Ib, aac(3)-IV, and aph(4)-Ia), tetracycline (tet(A)), and chloramphenicol (floR). It was susceptible to aztreonam, colistin, fosfomycin, and tigecycline. The genetic context surrounding bla_NDM-19 includes ISAba125-IS5-bla_NDM-19-ble_MBL-trpF-hp1-hp2-IS26. Hierarchical clustering of the core genome MLST (HierCC) indicated M2-13-1 clusters with global ST167 E. coli lineages, showing HC levels of 100 (HC100) core genome allelic differences. Plasmids of the IncX3 group and the insertion sequence (ISAba125) are critical vehicles for the dissemination of bla_NDM and its related variants. To our knowledge, this is the first genomic report of a bla_NDM-19/IncX3-carrying E. coli isolate of animal origin globally. Full article

Background: This study aimed to (a) assess the prevalence of multidrug-resistant (MDR) Enterobacteriaceae in the waters of two rivers and wastewater treatment plants (WWTPs) in a region of Catalonia, Spain; (b) genetically characterize the MDR strains; and (c) compare extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates from environmental and human sources. Methods: A total of 62 samples were collected from the influent and effluent of 31 WWTPs and 29 river water samples from 11 sites. Simultaneously, 382 hospitalized patients were screened for MDR Enterobacteriaceae using rectal swabs. All isolates underwent antibiotic susceptibility testing and whole-genome sequencing. Results: MDR Enterobacteriaceae were detected in 48.4% of WWTP samples, with 18.5% ESBL-producing E. coli and 1.5% (one sample) OXA-48-producing K. pneumoniae in influents, and 12.8% ESBL-producing E. coli in effluents. In river waters, 5.6% of samples contained ESBL-producing E. coli and 1.4% (1 sample) contained VIM-producing Enterobacter cloacae complex strains. Among patients, 10.2% (39/382) carried MDR Gram-negative bacilli, of which 66.7% were ESBL-producing E. coli. In aquatic ecosystems E. coli ST131 (13.3%) and ST162 (13.3%) were the most common strains, while in humans the common were E. coli ST131 (33.3%), ST69 (11.1%) and ST410 (7.4%) in humans. The most frequent environmental antibiotic resistance genes (ARG) were bla_CTX-M-15 (24%) and bla_TEM-1B (20%), while the most common ARGs were bla_TEM-1B (20.4%), bla_CTX-M15 (18.4%) and bla_CTX-M-27 (14.3%). IncF plasmids were predominant in environmental and human strains. Conclusions: ESBL-producing E. coli and carbapenemase-producing Enterobacteriaceae are present in aquatic environments in the region. Phylogenetic similarities between environmental and clinical strains suggest a possible similar origin. Further studies are necessary to clarify transmission routes and environmental impact. Full article

Sternal bursitis is an underexplored lesion in poultry, often overlooked in microbiological diagnostics. In this study, we characterized 36 Escherichia coli isolates recovered from sternal bursitis in broiler chickens, combining phenotypic antimicrobial susceptibility testing, PCR-based screening, and whole genome sequencing (WGS). The genetic analysis revealed a diverse population spanning 15 sequence types, including ST155, ST201, and ST58. Resistance to tetracycline and ciprofloxacin was common, and several isolates carried genes encoding β-lactamases, including blaTEM-1B. Chromosomal mutations associated with quinolone and fosfomycin resistance (e.g., gyrA p.S83L, glpT_E448K) were also identified. WGS revealed a high number of virulence-associated genes per isolate (58–96), notably those linked to adhesion (fim, ecp clusters), secretion systems (T6SS), and iron acquisition (ent, fep, fes), suggesting strong pathogenic potential. Many isolates harbored virulence markers typical of ExPEC/APEC, such as iss, ompT, and traT, even in the absence of multidrug resistance. Our findings suggest that E. coli from sternal bursitis may act as reservoirs of resistance and virulence traits relevant to animal and public health. This highlights the need for including such lesions in genomic surveillance programs and reinforces the importance of integrated One Health approaches. Full article

Introduction: In recent years, antimicrobial resistance (AMR) rates have increased significantly in bacterial pathogens, particularly extended beta-lactam resistance. This study aimed to investigate resistome and phylogenomics of Escherichia coli (E. coli) strains isolated from various sources in Jimma, Ethiopia. Methods: Phenotypic antibiotic resistance patterns of E. coli isolates were determined using automated Kirby–Bauer disc diffusion and minimum inhibitory concentration (MIC). Isolates exhibiting phenotypic resistance to beta-lactam antibiotics were further analyzed with a DNA microarray to confirm the presence of resistance-encoding genes. Additionally, multilocus sequence typing (MLST) of seven housekeeping genes was conducted using PCR and Oxford Nanopore-Technology (ONT) to assess the phylogenetic relationships among the E. coli isolates. Results: A total of 611 E. coli isolates from human, animal, and environmental sources were analyzed. Of these, 41.6% (254) showed phenotypic resistance to at least one of the tested beta-lactams, 96.1% (244) thereof were confirmed genotypically. More than half of the isolates (53.3%) had two or more resistance genes present. The most frequent ESBL-encoding gene was CTX-M-15 (74.2%; 181), followed by TEM (59.4%; 145) and CTX-M-9 (4.1%; 10). The predominant carbapenemase gene was NDM-1, detected in 80% (12 out of 15) of carbapenem-resistant isolates. A phylogenetic analysis revealed clonality among the strains obtained from various sources, with international high-risk clones such as ST131, ST648, ST38, ST73, and ST405 identified across various niches. Conclusions: The high prevalence of CTX-M-15 and NDM-1 in multidrug-resistant E. coli isolates indicates the growing threat of AMR in Ethiopia. The discovery of these high-risk clones in various niches shows possible routes of transmission and highlights the necessity of a One Health approach to intervention and surveillance. Strengthening antimicrobial stewardship, infection prevention, and control measures are crucial to mitigate the spread of these resistant strains. Full article

Avian pathogenic Escherichia coli (APEC) poses a global threat to poultry health and public safety due to its high lethality, limited treatment options, and potential for zoonotic transmission via the food chain. However, long-term genomic surveillance remains limited, especially in countries like China where poultry farming is highly intensive. This study aimed to characterize the population structure, virulence traits, and antimicrobial resistance of 81 APEC isolates from diseased chickens collected over 16 years from Shandong and neighboring provinces in eastern China. The isolates were grouped into seven Clermont phylogroups, with A and B1 being dominant. MLST revealed 27 STs, and serotyping identified 29 O and 16 H antigens, showing high genetic diversity. The minor phylogroups (B2, C, D, E, G) encoded more virulence genes and had higher virulence-plasmid ColV carriage, with enrichment for iron-uptake, protectins, and extraintestinal toxins. In contrast, the dominant phylogroups A and B1 primarily carried adhesin and enterotoxin genes. Antimicrobial resistance was widespread: 76.5% of isolates were multidrug-resistant. The minor phylogroups exhibited higher tetracycline resistance (mediated by tet(A)), whereas the major phylogroups showed increased resistance to third- and fourth-generation cephalosporins (due to bla_CTX-M-type ESBL genes). These findings offer crucial data for APEC prevention and control, safeguarding the poultry industry and public health. Full article

Background/Objectives: Cefiderocol is a novel siderophore cephalosporin with potent in vitro activity against a broad spectrum of Gram-negative bacteria, including carbapenemase-producing Enterobacterales (CPE). However, the recent emergence of resistance in clinical settings raises important concerns regarding its long-term effectiveness. This study aims to investigate the genomic determinants associated with cefiderocol resistance in CPE isolates of human origin. Methods: Comparative genomic analyses were conducted between cefiderocol-susceptible and -resistant CPE isolates recovered from human clinical and epidemiological samples at a tertiary care hospital. Whole-genome sequencing, variant annotation, structural modelling, and pangenome analysis were performed to characterize resistance mechanisms. Results: A total of 59 isolates (29 resistant and 30 susceptible) were analyzed, predominantly comprising Klebsiella pneumoniae, Escherichia coli, and Enterobacter cloacae. The most frequent carbapenemase gene among the resistant isolates was bla_NDM, which was also present in a subset of susceptible strains. The resistant isolates exhibited a significantly higher burden of non-synonymous mutations in their siderophore receptor genes, notably within fecR, fecA, fiu, and cirA. Structural modelling predicted deleterious effects for mutations such as fecR:G104S and fecA:A190T. Additionally, porin loss and loop 3 insertions (e.g., GD/TD) in OmpK36, as well as OmpK35 truncations, were more frequent in the resistant isolates, particularly in high-risk clones such as ST395 and ST512. Genes associated with toxin–antitoxin systems (chpB2, pemI) and a hypothetical metalloprotease (group_2577) were uniquely found in the resistant group. Conclusions: Cefiderocol resistance in CPE appears to be multifactorial. NDM-type metallo-β-lactamases and missense mutations in siderophore uptake systems—especially in those encoded by fec, fhu, and cir operons—play a central role. These may be further potentiated by alterations in membrane permeability, such as porin disruption and efflux deregulation. The integration of genomic and structural approaches provides valuable insights into emerging resistance mechanisms and may support the development of diagnostic tools and therapeutic strategies. Full article

Waterborne gastrointestinal infections remain a global health concern, with approximately 1.7 billion diarrhea-related illnesses annually attributable to protozoan parasites. These pathogens are transmitted through contaminated water and exhibit high resistance to chlorination, posing substantial challenges to effective water treatment. This study focused on the most prevalent intestinal parasites in the Los Ríos Region of Chile: Blastocystis sp., Giardia duodenalis, and Entamoeba coli. The objectives were to assess the prevalence of eukaryotic parasites in water samples—covering both drinking and recreational sources—to describe the circulating subtypes of Blastocystis sp. and to identify ecological factors associated with parasite presence. Water samples were analyzed using conventional PCR, next-generation sequencing (NGS) was employed for Blastocystis sp. subtype identification, and the environmental predictors were evaluated using a multivariable logistic regression model. A total of 132 water samples were analyzed, of which 15.2% were positive for Blastocystis sp. and 1.5% for E. coli, while no samples tested positive for G. duodenalis. We identified subtypes ST1–ST4 of Blastocystis sp., along with ST7, ST10, ST14, ST21, and ST23–ST26, the latter being reported for the first time in Chile. Ecological factors significantly associated with Blastocystis sp. presence included higher water temperature and greater rainfall at positive sites. Potable water was associated with significantly lower odds of Blastocystis sp. infection (aOR = 0.04, 95% CI: 0.00–0.87; p = 0.041), while precipitation increased infection odds by 3% per additional millimeter (aOR = 1.03, 95% CI: 1.00–1.06; p = 0.036). Greater distance to the nearest farmhouse was also significantly associated with reduced infection risk, suggesting that proximity to livestock environments may influence Blastocystis sp. transmission. These findings help explain the high prevalence of Blastocystis sp. observed in humans in the Los Ríos Region and highlight the pivotal role of ecological conditions in driving waterborne transmission. To our knowledge, this is the first environmental study in Chile to clearly demonstrate the association between human infection, environmental factors, and the transmission dynamics of Blastocystis sp. Full article

Diarrhea in alpaca crias significantly impacts livestock health in high-altitude regions, with Escherichia coli as a common pathogen. This study analyzed 10 E. coli isolates from diarrheic and healthy alpacas using whole-genome sequencing to assess genetic diversity, virulence factors, and antibiotic resistance. Predominant sequence types (ST73, ST29), serotypes (O22:H1, O109:H11), and phylogroups (B2, B1, A) were identified. Virulence profiling revealed ExPEC-like and EPEC pathotypes, while resistance genes for β-lactams (blaEC-15), fosfomycin (glpT_E448K), and colistin (pmrB) were prevalent. These findings highlight the need for genomic surveillance and antimicrobial stewardship to manage E. coli infections in alpacas and reduce public health risks. Full article

Leaves (LV), stems (STs), and inflorescences (IFs) of Pfaffia glomerata are usually discarded despite containing various bioactive compounds, especially β-ecdysone saponin. The objective was to optimize by desirability (DI) the ultrasound-assisted extraction (UAE) of bioactive compounds (total phenolics (TPCs), antioxidant activity (AA), and total saponins) from the aerial parts (LV, ST, and IF) of P. glomerata. Ideal drying conditions were determined and the drying kinetics were evaluated. LV, STs, and IFs were dried and extracted (0.06 g/mL 80% EtOH) in a USS (6 cm × 12 mm, pulse 3/6 s) by Central Composite Design (CCD), varying sonication power (140–560 W) and time (11–139 min), with TPC, AA by DPPH, and total saponin content as responses. The DI indicated that the higher TPC, AA, and saponin levels were obtained at 136.5 min and 137.87 W (STs), and 138.6 min and 562.32 W (LV and IFs). IF extracts contained higher saponin, TPCs, and AA. Higher β-ecdysone levels (3.90 mg g⁻¹) were present in the leaves. Several phenolics were detected in area parts of P. glomerata, the most abundant being p-coumaric acid (LV) and nicotinic acid (STs and IFs). These compounds provide potential health benefits. Phytol was found in all extracts. Extracts by UAE from leaves have antibacterial potential, with demonstrated inhibitory effects against S. aureus, E. coli, L. monocytogenes, S. Typhi, and P. aeruginosa, and presented bactericidal effects against E. coli, L. monocytogenes, and S. Typhi. Aerial parts of P. glomerata can be used to obtain extracts by UAE rich in bioactive compounds, providing complete utilization of the plant and sustainability to cultivation. This work represents the first report on the application of ecofriendly UAE techniques to extract bioactive compounds from the aerial parts of Brazilian ginseng. Full article

The emergence of colistin resistance poses a significant threat to its efficacy as a last-line treatment against multidrug-resistant Gram-negative bacterial infections. In this study, 178 multi-drug resistant (MDR) Escherichia coli isolates collected from clinical samples at Queen Sirikit Naval Hospital, Chonburi, Thailand, were evaluated for colistin resistance. Of these, six were identified as mcr gene carriers, mediating colistin resistance. Specifically, mcr-1 was detected in three E. coli isolates, mcr-3 was detected in one E. coli isolate, and mcr-1 and mcr-3 were detected in two E. coli isolates, designated AMR-0220 and AMR-0361. Whole-genome sequencing and bioinformatics analysis revealed that AMR-0220 and AMR-0361 belonged to ST410 and ST617 lineages, respectively. Both isolates carried multiple plasmids, with mcr-1.1 located on an IncX4-type plasmid that is closely related to previously reported mcr-1.1-carrying IncX4 plasmids. In contrast, mcr-3.5 was identified on distinct plasmid backbones: an IncFIB-type plasmid in AMR-0220 and an IncFII-type plasmid in AMR-0361. Overall, our findings demonstrate that the mcr genes found in E. coli isolates in this region are located on different mobile genetic elements, indicating the potential for a widespread dissemination of colistin resistance among Gram-negative bacteria throughout Thailand’s healthcare system. Full article

Background: High-risk Escherichia coli clones, such as sequence type (ST)131 and ST1193, along with multidrug-resistant (MDR) Klebsiella pneumoniae, are globally recognized for their significant role in urinary tract infections (UTIs). This study aimed to provide an overview of the virulence factors, clonal diversity, and antibiotic resistance profiles of extended-spectrum cephalosporin (ESC)-E. coli and K. pneumoniae causing UTIs in humans in the Tebessa region of Algeria. Methods: Forty E. coli and 17 K. pneumoniae isolates exhibiting ESC-resistance were recovered (July 2022–January 2024) from urine samples of patients at three healthcare facilities to be phenotypically and genotypically characterized. Whole genome sequencing (WGS) was performed on the ST1193 clone. Results: Among K. pneumoniae isolates, all except one harbored CTX-M-15, with a single isolate carrying bla_CTX-M-194. Additionally, two K. pneumoniae isolates co-harboring bla_CTX-M-15 and bla_NDM exhibited phenotypic and genotypic hypervirulence traits. Fluoroquinolone resistance (FQR) was detected in 94.1% of K. pneumoniae isolates. The E. coli isolates carried diverse ESC-resistance genes, including CTX-M-15 (87.5%), CTX-M-27 (5%), CTX-M-1, CMY-59, and CMY-166 (2.5% each). Co-carriage of bla_ESC and bla_OXA-48 was identified in three E. coli isolates, while 62.5% exhibited FQR. Phylogenetic analysis revealed that 52.5% of E. coli belonged to phylogroup B2, including the high-risk clonal complex (CC)131 CH40-30 (17 isolates) and ST1193 (one isolate). In silico analysis of the ST1193 genome determined O75:H5-B2 (CH14-64), and the carriage of IncI1-I(Alpha) and IncF [F-:A1:B10] plasmids. Notably, core genome single-nucleotide polymorphism (SNP) analysis demonstrated high similarity between the Algerian ST1193 isolate and a previously annotated genome from a hospital in Northwest Spain. Conclusions: This study highlights the spread and genetic diversity of E. coli CC131 CH40-30 and hypervirulent K. pneumoniae clones in Algeria. It represents the first report of a CTX-M-15-carrying E. coli ST1193 in the region. The findings emphasize the urgent need for antibiotic optimization programs and enhanced surveillance to curb the dissemination of high-risk clones that pose an increasing public health threat in Algeria. A simplified method based on virulence traits for E. coli and K. pneumoniae is proposed here for antimicrobial resistance (AMR) monitoring. Full article

Background: Mapping the local etiology and susceptibility of common pathogens causing complicated urinary tract infection (cUTI) is important for promoting evidence-based antimicrobial prescribing. Evaluating the prevalence of extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase (AmpC), and carbapenemase-producing Enterobacterales (CPEs) is equally important as it informs treatment guidelines and empiric management. Whole genome sequencing (WGS) enhances antimicrobial resistance (AMR) surveillance by complementing phenotypic antimicrobial susceptibility testing, offering deeper insights into resistance mechanisms, transmissions, and evolutions. Integrating it into routine AMR monitoring can significantly improve global efforts to combat antimicrobial resistance. Methods: Antimicrobial susceptibility profiles of isolates from cUTI were collected from patients presenting with Sultan Qaboos University Hospital, Muscat and Suhar Hospital, Suhar, Oman. Automated systems as well as manual methods were used for detection of ESBL, AmpC, and CPE. ESBLs, AmpC β-lactamases, and CPEs were further detected by manual methods: double-disk synergy test for ESBL; disk approximation assay and D69C AmpC detection set for AmpC, and mCIM and KPC/IMP/NDM/VIM/OXA-48 Combo test kit for CPE. WGS was carried out in 11 FOX-resistant E. coli and (22 carbapenem-resistant K. pneumoniae) isolates with varying susceptibilities to identify circulating clades, AMR genes, and plasmids. Bioinformatic analysis was performed using online tools. Results: The susceptibility patterns of E. coli from cUTI were as follows: nitrofurantoin (96%), fosfomycin (100%), fluoroquinolones (44%), aminoglycosides (93%), piperacillin-tazobactam (95%), and carbapenems (98%). In comparison, susceptibility rates of K. pneumoniae were far lower: nitrofurantoin (38%), fosfomycin (89%), aminoglycosides (82%), piperacillin-tazobactam (72%), and carbapenems (83%). K. pneumoniae, however, was more susceptible to fluoroquinolones at 47% in comparison to E. coli. The prevalence of ESBL among E. coli and K. pneumoniae was 37.2% and CRE was 6.2% while the estimated prevalence of AmpC was 5.4%. It was observed that E. coli was the predominant ESBL and AmpC producer, while K. pneumoniae was the major carbapenem-resistant Enterobacterales (CREs) producer. No predominant multi-locus sequence typing (MLST) lineage was observed in AmpC-producing E. coli with nine E. coli MLST lineages being identified from eleven isolates: ST-10, ST-69, ST-77, ST-131, ST-156, ST-167, ST-361, ST-1125, and ST-2520. On the other hand, a less diverse MLST spectrum (ST-2096, ST-231, ST-147, ST-1770, and ST-111) was observed in the CRE K. pneumoniae. Among the five MLST lineages, ST-2096 (twelve isolates) and ST-147 (seven isolates) predominated. WGS revealed that DHA-1 was the predominant plasmid-mediated AmpC gene in E. coli, while OXA-232 and NDM-5 were the most common carbapenemase genes in K. pneumoniae. All E. coli DHA-1-positive isolates co-harbored the quinolone resistance gene qnrB4 and the sulfonamide resistance gene sul1 while no aminoglycoside resistance genes were detected. The majority of CPE CRE K. pneumoniae carried other β-lactamase genes, such as blaCTX-M-15, blaSHV, and blaTEM; all co-harbored the quinolone resistance gene OqxAB; and 77% carried the aminoglycoside resistance gene armA. Conclusions: Our results suggest that fosfomycin is an excellent empiric choice for treating complicated cystitis caused by both E. coli and K. pneumoniae, while nitrofurantoin is an appropriate choice for E. coli cystitis but not for K. pneumoniae. Aminoglycosides and piperacillin-tazobactam are excellent intravenous alternatives that spare carbapenems. DHA-1 was the predominant AmpC in E. coli, while OXA-232 and NDM-5 were the predominant carbapenemases in K. pneumoniae. In AmpC-producing E. coli, no MLST predominated, suggesting a significant flux in E. coli with lack of stable clades in this region. In contrast, ST-2096 and ST-147 predominated in CRE Klebsiella pneumoniae, suggesting a stable circulation of these in Oman. WGS profiling provides a deeper understanding of the genetic basis of resistance and enhances surveillance and offers comprehensive insights into pathogen evolution and transmission patterns. Full article

Escherichia coli is a significant pathogen capable of inducing a variety of infections in both human and animal hosts. Despite its clinical significance, there is a lack of longitudinal research aimed at elucidating the genomic attributes that facilitate antimicrobial resistance and clonal dissemination in this bacterium. In this study, we investigated the genetic dynamics of antibiotic resistance and virulence factors within a collection of 137 E. coli isolates retrieved from a Chinese hospital over a 12-year period. Notably, a substantial increase in resistance to various antibiotics, including broad-spectrum β-lactams, aminoglycosides, and quinolones, was observed. Additionally, our study revealed the acquisition of diverse antibiotic resistance and virulence genes across different sequence types (STs). Among the STs, ST131 emerged as the most prevalent, exhibiting a high level of multidrug resistance. In contrast, ST73 and ST12 demonstrated a higher prevalence of virulence genes, suggestive of a potential trade-off between antibiotic resistance and virulence. What’s more, we identified significant intra-clonal diversification and convergence of antibiotic resistance and virulence traits within the dominant ST131 group. These findings underscore the importance of longitudinal studies in understanding the evolution of bacterial pathogens and the necessity for ongoing research to inform public health strategies. Full article

This study aims to explore the therapeutic potential of Angelicae Pubescentis Radix (APR), a traditional Chinese medicine that is widely known for its anti-inflammatory, anti-oxidative, and anti-microbial properties, using a mouse model. In this study, 30 mice were selected and divided into three groups: control group (CD), infection group (ED), and treatment group (TD). Mice in the TD were gavaged with APR oil (0.15 mL/kg/day) for 20 days, while mice in the CD and ED received an equal volume of normal saline. On the 21st day, mice in the ED and TD were infected with multi-drug-resistant E. coli (1 × 10⁷ CFU/mL) derived from diarrheal yak. Twenty-four hours later, all mice were euthanized, and blood, organs, and intestinal samples were collected for analysis. The results of intestinal sections and intestinal bacterial load revealed that APR treatment significantly reduced (p < 0.05) both bacterial load and intestinal injury. Serum analysis indicated that APR treatment also alleviated the inflammation and oxidative stress induced by E. coli infection. Intestinal microbiota sequencing further showed that APR treatment increased the abundance of intestinal probiotics such as Ligilactobacillus, Paludicola, and Blautia_A_1417806 while also enhancing the enrichment of functional pathways associated with antioxidant defense. In conclusion, APR treatment effectively alleviates diseases caused by E. coli infection, promotes the growth of beneficial intestinal bacteria, and improves the antioxidant capacity in animals. Additionally, these findings confirm APR’s role in addressing immediate effects rather than chronic adaptations. Future studies should investigate the prolonged effects of APR treatment beyond the acute phase. Full article

After weaning, piglets no longer consume breast milk, and their immune system is not yet fully developed. At this time, if weaned piglets are infected with E. coli, their subsequent growth will be seriously affected. In the present study, 48 healthy 28-day-old weaned piglets (6.65 ± 1.19 kg, Duroc × Landrace × Large White) were randomly divided into an LPS group and control group. Piglets in the LPS group were intraperitoneally injected with an LPS solution (LPS was dissolved in sterile saline to form a solution of 100 μg/mL and injected at a dose of 1 mL per kilogram of body weight) for 13 consecutive days. Piglets in the control group were injected with the same volume of sterile saline. On days 1, 5, 9, and 13 of the experiment, six piglets from each group were randomly selected for dissection, the blood and heart samples were collected, and then cardiac function-related indicators were detected. A portion of the heart tissue was fixed in 4% paraformaldehyde and further used to make paraffin sections; then, hematoxylin–eosin (H&E) staining was performed. Masson staining was used to detect the changes in collagen fibers in the hearts. The other parts of the heart tissues were frozen in liquid nitrogen and stored in a refrigerator at −80 °C for the detection of tissue antioxidant indices. The mRNA expression levels of the toll-like receptor 4 (TLR4) signaling pathway, transforming growth factor-β (TGF-β) signaling pathway, and inflammatory cytokines in heart tissues were detected by real-time PCR. The results showed that catalase (CAT) and superoxide dismutase (SOD) contents in the heart tissue homogenates increased significantly on days 1 and 5 in LPS-induced piglets (p < 0.01, p < 0.05), while total antioxidant capacity (T-AOC) and glutathione peroxidase (GSH-Px) contents decreased significantly on day 5 (p < 0.05). On day 5, the contents of serum cardiac function indicators lactate dehydrogenase (LDH), creatine kinase isoenzymes (CK-MB), and cardiac troponin I (cTn-I) were significantly increased in LPS-induced piglets (p < 0.01). On the 1st and 5th days, the heart tissue showed obvious pathological damage, which was manifested as the disordered arrangement of myocardial fibers, depression of myocardial cells, infiltration of inflammatory factors, congestion of capillaries, and significant increase in cardiac collagen fibers. On the 1st day, the mRNA expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) were significantly increased in LPS-induced piglets with heart injury (p < 0.01). On the 5th day, the mRNA expression levels of the TLR4 signaling pathway [TLR4, myeloid differentiation primary response gene 88 (MyD88), nuclear factor kappa-B (NF-κB)], TNF-α, and interleukin 10 (IL-10) were also significantly increased in LPS-induced piglets with heart injury (p < 0.01, p < 0.05). The mRNA expression levels of the TGF-β signaling pathway (TGF-β, Smad2, and Smad4) in cardiac fibrosis-related genes were significantly increased on days 5 and 9 (p < 0.01, p < 0.05). The mRNA expression levels of Smad3 and Smad7 in cardiac fibrosis-related genes were also significantly increased on day 9 (p < 0.01). These results indicate that oxidative stress occurs in the heart tissue of LPS-induced piglets on the 1st and 5th days, leading to cardiac tissue damage. However, on the 9th and 13th days, the degree of heart damage in the piglets was less than that on the 1st and 5th days, which may be due to the tolerance of piglets’ tissues and organs because of multiple same-dose LPS stimulations. Full article