Pathogenic Escherichia coli

The emergence of highly resistant and hypervirulent Escherichia coli ST405 clone in a tertiary hospital over 8 years

The emergence of carbapenem-resistant Escherichia coli (CREC) poses crucial challenges in clinical management, requiring continuous monitoring to inform control and treatment strategies. This study aimed to investigate the genomic and epidemiological characteristics of CREC isolates obtained from a tertiary hospital in China between 2015 and 2022. Next-generation sequencing was used for genomic profiling, and clinical data from patients were integrated into the analysis. ST405 (21.2%), ST167 (20.3%) and ST410 (15.9%) were the most prevalent of the 30 distinct sequence types (STs) identified among the 113 unique CREC isolates. Infections caused by the ST405 CREC clone and severe underlying diseases were associated with higher in-hospital mortality rates, particularly in patients aged ≥65 years. Furthermore, the ST405 clone exhibited a greater number of virulence and resistance genes than non-ST405 CREC clones. The virulence gene eaeX and resistance genes mph(E) and msr(E) were exclusively found in ST405 clones, while other virulence genes (agn43, ipad and malX) and resistance genes (armA, catB3 and arr-3) were more prevalent in this clones. Additionally, ST405 showed higher minimum inhibitory concentrations for both meropenem and imipenem and showed superior growth under the meropenem challenge. Galleria mellonella virulence assays revealed that the ST405 CREC clone was more virulent than other predominant CREC STs. Our findings underscore the clinical threat posed by the ST405 CREC clone, which exhibits both enhanced virulence and extensive drug resistance. These results highlight the urgent need for stringent surveillance and targeted interventions to curb its further dissemination and prevent potential outbreaks.

Genomic island-encoded LmiA regulates acid resistance and biofilm formation in enterohemorrhagic Escherichia coli O157:H7

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important intestinal pathogen that causes severe foodborne diseases. We previously demonstrated that the genomic island-encoded regulator LmiA activates the locus of enterocyte effacement (LEE) genes to promote EHEC O157:H7 adherence and colonization in the host intestine. However, whether LmiA is involved in the regulation of any other biological processes in EHEC O157:H7 remains largely unexplored. Here, we compared global gene expression differences between the EHEC O157:H7 wild-type strain and an lmiA mutant strain using RNA-seq technology. Genes whose expression was affected by LmiA were identified and classified using the Cluster of Orthologous Groups (COG) database. Specifically, the expression of acid resistance genes (including gadA, gadB, and gadC) was significantly downregulated, whereas the transcript levels of biofilm-related genes (including Z_RS00105, yadN, Z_RS03020, and fdeC) were increased, in the ΔlmiA mutant compared to the EHEC O157:H7 wild-type strain. Further investigation revealed that LmiA enhanced the acid resistance of EHEC O157:H7 by directly activating the transcription of gadA and gadBC. In contrast, LmiA reduced EHEC O157:H7 biofilm formation by indirectly repressing the expression of biofilm-related genes. Furthermore, LmiA-mediated regulation of acid resistance and biofilm formation is highly conserved and widespread among EHEC and enteropathogenic E. coli (EPEC). Our findings provide essential insight into the regulatory function of LmiA in EHEC O157:H7, particularly its role in regulating acid resistance and biofilm formation.

Indole signaling in Escherichia coli: a target for antivirulence therapy?

Pathogenic Escherichia coli are a major cause of infections in both humans and animals, leading to conditions such as severe diarrheal diseases, urinary tract infections, enteritis, and septicemia. To combat bacterial infections, antibiotics are widely utilized. However, the extensive and inappropriate use of antibiotics has fueled the development and spread of antibiotic resistance, posing a significant challenge to the effective treatment of E. coli. There is consequently an urgent need to explore alternative therapies to control such infections. This review provides an overview of the recent findings concerning indole signaling in E. coli. E. coli uses indole as a quorum sensing molecule, and indole signaling has been reported to decrease various virulence factors in pathogenic E. coli, including motility, biofilm formation, adherence to host cells, expression of the LEE pathogenicity island, and formation of attaching and effacing lesions. This makes indole signaling an interesting target for the development of new therapeutics in the framework of antivirulence therapy. Both natural and synthetic indole analogues have been explored as potential virulence inhibitors. This alternative approach could be advantageous, as it will exert less selective pressure for resistance development than conventional antibiotics.

The crystal structure of the toxin EspC from enteropathogenic Escherichia coli reveals the mechanism that governs host cell entry and cytotoxicity

Enteropathogenic E. coli (EPEC) is a significant cause of diarrhea, leading to high infant mortality rates. A key toxin produced by EPEC is the EspC autotransporter, which is regulated alongside genes from the locus of enterocyte effacement (LEE), which collectively result in the characteristic attaching and effacing lesions on the intestinal epithelium. In this study, we present the crystal structure of the EspC passenger domain (αEspC) revealing a toxin comprised a serine protease attached to a large β-helix with additional subdomains. Using various modified EspC expression constructs, alongside type III secretion system-mediated cell internalization assays, we dissect how the αEspC structural features enable toxin entry into the intestinal epithelium to cause cell cytotoxicity.

Rapid and sensitive biosensing of uropathogenic E. coli using plasmonic nanohole arrays on MIM: Bridging the gap between lab and clinical diagnostics

This study introduces a novel biosensing platform, Plasmonic Array Nanohole Technology on Metal-Insulator-Metal (PANTOMIM), designed to overcome limitations of traditional plasmonic nanohole array biosensors. PANTOMIM utilizes a metal-insulator-metal structure as a lossy waveguide to dampen metal/substrate peaks, ensuring high extinction coefficients and spectral purity for biosensing. The architecture is optimized for the 800-850 nm wavelength range, with potential for future integration into nanophotonic devices. To demonstrate its clinical utility, we applied PANTOMIM to the detection of uropathogenic Escherichia coli (UPEC) in urine samples. This approach addresses the need for rapid diagnosis of urinary tract infections, providing results in 15 min and requiring minimal sample preparation. The efficacy of the technology was validated in a clinical setting with a cohort of 100 patients, showcasing its potential to revolutionize the detection of UPEC. PANTOMIM combines the advantages of plasmonic nanohole arrays, including tunable periodicity, coupled plasmonic response, and extraordinary optical transmission, while mitigating the challenges associated with thin-film plasmonic metals. This innovation paves the way for integrated nanoplasmonic biosensors for point-of-care diagnostics.

Modelling Escherichia coli concentrations: 45.6 %-78.1 % of China's rivers show poor microbial water quality

Water quality is under threat due to the presence of pathogenic and antibiotic-resistant bacteria. Escherichia coli (E. coli) serves as an indicator of faecal contamination and the potential presence of other harmful pathogens. Understanding E. coli concentrations helps in assessing the overall health risks associated with waterborne diseases and developing effective water management strategies. Therefore, we developed the first large-scale model, GloWPa-Ecoli C1 to simulate E. coli loads and concentrations in rivers and apply this model to China. The model provides the first comprehensive overview of microbial water quality across China's rivers. The model simulates E. coli concentrations in 2020 to range from 10-1.2 to 106.3 CFU/L, with 45.6 %-78.1 % of rivers exhibiting poor microbial water quality. Major hotspots of E. coli pollution are Haihe, Huaihe and Pearl River Basins. Direct discharge of human faecal waste contributes 80.2 % of the total E. coli load, while directly discharged livestock waste accounts for 13.1 %. To mitigate E. coli pollution in rivers in China, we recommend increasing human faecal waste collection rates, expanding wastewater treatment plant (WWTP) coverage, phasing out primary treatment WWTPs and eliminating direct livestock faecal waste discharge, particularly from smallholder farms. The study underscores the urgent need to improve microbial water quality in China's rivers. The findings provide actionable insights to inform policy development aimed at safeguarding water quality and public health. Furthermore, the modelling approach is applicable to other regions and microorganisms, offering a foundation for developing models to address antibiotic-resistant bacteria and other emerging water quality challenges.

Effects of Metabolites of Lactobacillus casei on Expression and Neutralization of Shiga Toxin by Enterohemorrhagic Escherichia coli

Shiga toxin (stx), produced by enterohemorrhagic Escherichia coli (EHEC) or Shigella, causes hemolytic uremic syndrome (HUS) in humans. EHEC-mediated illnesses are recommended to treat by immune supportive strategies, instead of antibiotic therapy. Widely used probiotic Lactobacillus casei produces many bioactive metabolites, i.e., conjugated linoleic acids (CLAs) which have potential to educate host immunity and control EHEC growth and expression of its virulence genes. In this study, it was found that total metabolites of L. casei exerted a protective effect on Gb3 receptor containing mammalian cells against stx exposure.

Drosera rotundifolia L. as E. coli biofilm inhibitor: Insights into the mechanism of action using proteomics/metabolomics and toxicity studies

The successful sustainable cultivation of the well-known medicinal plant sundew on rewetted peatlands not only leads to the preservation of natural populations, but also provides a basis for the sustainable pharmaceutical use of the plant. The bioactive compounds of sundew, flavonoids and naphthoquinones, show biofilm-inhibiting properties against multidrug-resistant, ESBL-producing E. coli strains and open up new therapeutic possibilities. This study investigates the molecular mechanisms of these compounds in biofilm inhibition through proteomic analyses. Specific fractions of flavonoids and naphthoquinones, as well as individual substances like 7-methyljuglone and 2″-O-galloylhyperoside, are analyzed. Results show that naphthoquinones appear to act via central regulatory proteins such as OmpR and alter the stress response while flavonoids likely affect biofilm formation by creating an iron-poor environment through iron complexation and additionally influence polyamine balance, reducing intracellular spermidine levels. Further investigations including assays for iron complexation and analysis of polyamines confirmed the proteomic data. Safety evaluations through cytotoxicity tests in 3D cell cultures and the Galleria mellonella in vivo model confirm the safety of the extracts used. These findings highlight sundew as a promising candidate for new phytopharmaceuticals.

Application of bacteria-mediated gene therapy in tumor treatment

INTRODUCTION

Gene therapy refers to the use of vectors to introduce target genes into target cells to exert a therapeutic effect on tumors. As a new type of tumor therapy, gene therapy has the advantage of precision and specificity. Excellent delivery vehicles have a major impact on the efficiency, precision and safety of gene therapy. Unlike traditional vectors, bacteria based on prokaryotes have the advantages of good targeting, large load, and simplicity. In addition, different types of bacteria also have characteristics that can be used in various scenarios.

AREAS COVERED

In this review, we searched the gene therapy-related literature in PubMed, mainly in the last five years, and compared the characteristics of different gene vectors, focusing on the bacterial gene therapy and aiming to explore excellent bacterial gene therapy programs.

EXPERT OPINION

Compared with traditional tumor gene therapy vectors, bacteria have many advantages, such as good targeting, large carrying capacity, and simple production. Meanwhile, the combination of artificial intelligence technology, bacterial imaging probe technology and suicide genes will be expected to control the bacterial therapy process, improve the safety of treatment, and promote the translational application of bacterial gene therapy.

Characterization and antimicrobial resistance of commensal and pathogenic Escherichia coli from pigs in Sardinia (Italy)

This study investigated commensal and pathogenic E. coli isolated from pigs at farms and slaughterhouses in Sardinia, focusing on genetic relatedness and antimicrobial resistance (AMR). Samples were collected from six fattening pig farms (A-F) and five slaughterhouses (S1-S5). In the farms, environmental fecal sampling from the fattening pigs' pens was carried out and information regarding farm management and biosecurity measures were collected. Pigs that had been in the sampled pens were selected for sampling at the slaughterhouse. Carcass surface, mesenteric lymph nodes and colon content samples were sampled at the five slaughterhouses (S1-S5), in total 38 samples from 152 animals were collected. At the slaughterhouses, environmental samples were also collected from food-contact surfaces and non-food-contact surfaces (36 samples overall). E. coli was detected in all farms, 97 % of pigs, and all slaughterhouses. Whole genome sequencing and antimicrobial susceptibility testing were performed on 95 isolates, revealing 13.7 % pathogenic isolates, including ExPEC, ETEC, STEC-ETEC hybrids, and UPEC. A total of 40 sequence types (STs) were identified, with ST10 being the most common. High-risk clones (ST88, ST101, ST410, and ST648) were also detected. Over half of the isolates (52.6 %) carried at least one AMR gene, with 43 % harboring multiple AMR genes, particularly tet (37.9 %) and blaTEM (32.6 %). Phenotypic resistance was observed for tetracycline, ampicillin, and sulfamethoxazole-trimethoprim. This study reveals extensive AMR in commensal and environmental E. coli, underscoring their role as resistance gene reservoirs. The presence of AMR genes without direct antimicrobial exposure suggests complex transmission dynamics. Findings support the significance of AMR surveillance also for commensal E. coli, and the importance of combining phenotypical and sequencing methods to assess antimicrobial removal effects in pig farms.

Comparative analysis of diarrheagenic and uropathogenic Escherichia coli isolates: antimicrobial resistance, virulence, and genomic profiling

AIMS

Escherichia coli is a key pathogen causing gastrointestinal and urinary tract infections. Diarrheagenic E. coli (DEC) and uropathogenic E. coli (UPEC) are distinct major pathotypes linked to specific clinical outcomes. Therefore, this study aimed to compare DEC and UPEC isolates regarding distribution, antimicrobial resistance, serotypes, resistance, and virulence gene profiles.

MATERIALS AND METHODS

A total of 400 clinical samples (200 stools and 200 urine) were analyzed using phenotypic and genotypic methods. Antimicrobial resistance, serotyping, and detection of resistance and virulence genes were performed. Phylogenetic and correlation analyses were conducted to explore genetic relationships and interactions.

RESULTS

Of 97 E. coli isolates (24.25% prevalence), 56 DEC and 41 UPEC were detected. DEC isolates primarily included serotypes O26, O45, and O55, while UPEC predominantly featured O1 and O25. UPEC showed higher multidrug resistance, while DEC was more virulent. UPEC carried unique markers (ureC, papC), and DEC harbored stx and aggR genes associated with gastrointestinal infections. Phylogenetic analysis showed separate clustering for DEC and UPEC, with limited genetic overlap. Correlation analysis identified strong associations within resistance and virulence genes but a negative correlation between these traits.

CONCLUSION

This study compared the phenotypic and genetic features of DEC and UPEC, highlighting their distinct pathogenic traits. Limited genetic overlap suggests potential gene transfer, influencing adaptability, and evolution.

The Gut Microbiome in Anxiety Disorders

PURPOSE OF REVIEW

We aim to update readers on the latest evidence regarding the role of the gut microbiome in generalized anxiety disorder (GAD), panic disorder (PD), agoraphobia, and social anxiety disorder (SAD). This review summarises the literature on microbiome composition and function in these conditions, provides insights about causality and mechanisms and evaluates current evidence for microbiome-based interventions in anxiety disorders.

RECENT FINDINGS

Most studies exploring the microbiome in anxiety disorders are small, cross-sectional studies. Nevertheless, some consistent findings emerge. Bacterial taxa such as Eubacterium, Coprococcus and Faecalibacterium may be depleted in GAD. Studies in PD and SAD are scarce and, to our knowledge, there have been no studies conducted in agoraphobia. Probiotics may help reduce anxiety symptoms, although the majority of studies have been in non-clinical cohorts. Large, prospective studies are required to further elucidate the role of the microbiome-gut-brain axis in anxiety disorders. Microbiome-based interventions hold promise, but randomised controlled trials in clinical populations with relevant diagnoses are now warranted and urgently required.

Tuning the lipophilicity of new ciprofloxacin derivatives in selected ESKAPE bacteria with emphasis on E. coli mutants

The objective of the present study was to improve the antimicrobial profile of ciprofloxacin by introducing a peptidomimetic function. A ciprofloxacin C3 carboxyl group was modified by a three-component Passerini reaction conducted under micellar conditions. The series of newly synthesized peptidomimetics was evaluated for their possible in vitro antibacterial activity toward including selected LPS-varied E. coli strains. A preliminary exploration of ciprofloxacin-based peptidomimetic analogues as novel antimicrobial agents was carried out to determine the basic characteristics of the structure responsible for the observed biological activity. The collected data demonstrated that an appropriate modification of the C3 position of ciprofloxacin significantly extends and improves antimicrobial activity, particularly against LPS-varied E. coli strains, which may cause various diseases such as urinary tract infections (UTI), enteric / diarrheal disease, and sepsis/meningitis. Furthermore, the antimicrobial activities of peptidomimetics against selected Gram-positive and Gram-negative bacterial strains belonging to ESKAPE bacteria (A. baumannii, P. aeruginosa, E. cloacae, and S. aureus) were investigated. All synthesized ciprofloxacin derivatives were found to be more potent antibacterial agents than the native compound. Most importantly, the introduction of a short aliphatic substituent into the peptidomimetic structure allowed to enhance and extend the activity of modified ciprofloxacin not only to the native E. coli strain but also to all of its tested mutants. The results showed that all tested peptidomimetics have enhanced antimicrobial activities (MIC values from 0.22 to 2.19 μM) as compared to ciprofloxacin (MIC = 0.62 to 3.44 μg/mL). Furthermore, the cytotoxicity of sixteen derivatives was measured using the MTT test on BALB/c3T3 mouse fibroblast cell lines. Cytotoxicity studies revealed that the tested substances exert a similar or lower effect on cell proliferation than that observed for native ciprofloxacin. This study presents that it is possible to extend the antimicrobial activity of ciprofloxacin by appropriate modification of its structure, which can prolong its use. This is very important in light of the reports incoming on pathogens in nosocomial infections that acquire resistance to this antibiotic.

Mechanisms of Pathogenic Escherichia coli Attachment to Meat

Escherichia coli are present in the human and animal microbiome as facultative anaerobes and are viewed as an integral part of the whole gastrointestinal environment. In certain circumstances, some species can also become opportunistic pathogens responsible for severe infections in humans. These infections are caused by the enterotoxinogenic E. coli, enteroinvasive E. coli, enteropathogenic E. coli and the enterohemorrhagic E. coli species, frequently present in food products and on food matrices. Severe human infections can be caused by consumption of meat contaminated upon exposure to animal feces, and as such, farm animals are considered to be a natural reservoir. The mechanisms by which these four major species of E. coli adhere and persist in meat postslaughter are of major interest to public health and food processors given their frequent involvement in foodborne outbreaks. This review aims to structure and provide an update on the mechanistic roles of environmental factors, curli, type I and type IV pili on E. coli adherence/interaction with meat postslaughter. Furthermore, we emphasize on the importance of bacterial surface structures, which can be used in designing interventions to enhance food safety and protect public health by reducing the burden of foodborne illnesses.

Occurrence of multidrug resistant/extended spectrum beta-lactamase-producing Escherichia coli isolates belonging to high-risk clones from healthy 1-day-old broiler and layer chicks without in ovo or day-of-hatch antibiotic administration

This study aimed to investigate the presence of antimicrobial resistant Escherichia coli (E. coli) among healthy day-old broiler and layer chicks in the absence of in ovo or day-of-hatch antibiotic administration. A total of 100 pooled samples from 14 hatcheries across western Algeria were collected for analyses. Antimicrobial susceptibility testing was performed using the disc-diffusion method. Genes encoding antibiotic resistance, integrons, and phylogenetic groups were screened using Polymerase Chain Reaction (PCR), with the genetic relatedness of extended spectrum beta-lactamase (ESBL)-producing isolates determined via multilocus sequence typing. Sixty-eight samples contained E. coli, with high levels of resistance to multiple antibiotics found among broiler (92.10%) and layer chicks (100%) (no significant statistical association, P < 0.05). Multidrug-resistant (MDR)/ESBL-producing isolates were detected in samples from both broiler (n = 11) and layer (n = 2) hatcheries, from which three and five harbored blaCTX-M-1 and blaCTX-M-14, respectively. Additionally, tetA (n = 7), sul1 (n = 5), aac(6´)-Ib-cr (n = 2), and int1 (n = 7) genes were detected. Isolates belonged to the clones ST10 (n = 1), ST617 (n = 1), ST405 (n = 3), ST69 (n = 4), ST224 (n = 3), and ST4494 (n = 1). Study findings indicate that even in the absence of any prior antibiotic administration, day-old chicks in western Algerian hatcheries carry MDR isolates capable of spreading across the national poultry sector, representing a significant public health concern.

Invited review: Mastitis Escherichia coli strains-Mastitis-associated or mammo-pathogenic?

Bovine mastitis remains a major concern for dairy farmers, mainly because of its effect on the economy of their activity and on animal welfare. Because Escherichia coli is considered a major mastitis pathogen, the diversity of E. coli strains isolated from mastitis cases has been studied for decades, with the aim to discover new ways to fight this infection. With the recent advances in whole-genome sequencing, a detailed view of the peculiarities of mastitis E. coli strains has emerged. This review aims to bring together the knowledge garnered over the years with the more recent results of whole-genome analyses. Whereas the concept of a mammary pathogenic E. coli has been proposed, because a common set of virulence genes cannot be identified among mastitis E. coli strains, we prefer the use of mastitis-associated E. coli (MAEC), with MAEC being more an "ecotype" rather than a "pathotype." Indeed, data available so far suggest that a common feature of MAEC would rather be an enrichment in fitness capabilities that makes them well-suited for survival and rapid adaptation to changing biotopes in the mammary gland, which we qualify as intramammary ecotopes.

Revolutionizing Escherichia coli detection in real samples with digital SERS aptamer sensor technology

Aptamer sensors based on surface-enhanced Raman scattering (SERS) technology have demonstrated great potential in the ultrasensitive and rapid detection of Escherichia coli (E. coli). Herein, this paper presents a digital SERS aptamer sensor. This sensor integrates ordered nanoscale array synthesis technology and digital analysis technology, enabling highly sensitive and rapid bacterial quantification. The ordered monolayer gold nanosphere arrays (Au NS) can form uniform and dense "hot spots" on the silicon wafer due to their uniform spherical structures and narrow gaps. Moreover, digital SERS is adopted to further optimize the signal uniformity so as to achieve precise quantification. The sensor modules are combined together through base pairing. The aptamers labeled with Raman tags are detached from the complementary DNA due to the competition of the target substance, thus realizing the detection of E. coli. The digital SERS aptamer sensor has been verified to possess excellent selectivity and reproducibility. It has a wide dynamic linear detection range from 1.0 * 101 to 1.0 * 109 CFU/ml and a detection limit of 0.657 CFU/ml, maintaining excellent specificity even in the presence of mixed bacterial interference. The spiked recoveries in actual samples range from 98.80 % to 99.81 %. Leveraging different aptamers and digital analysis, the sensor holds promise for food safety and environmental monitoring applications.

Direct Interaction of Long-Term Reactive Oxygen-Based Species Stored in Microencapsulation of Olive Oil on Burn Scars of Wistar Rats

Oxygen anions (superoxide and peroxide anions) are naturally unstable and prone to chemical interactions. These reactive oxygen species (ROS) are formed during long-term storage in olive oil (OO), the structural properties of which extend the ROS lifespan more effectively than those of other vegetable oils. In wound treatment, superoxide anions serve as precursors for hydrogen peroxide and play a crucial role in cell proliferation, migration, and angiogenesis. These anions were encapsulated within the OO medium for crystallization. Piezoelectric actuators were employed to distribute the trapped bubbles evenly throughout the crystallized OO. The ROS-filled OO microcapsules eliminated volatile organic compounds and particulate matter (from the air). Samples stored in crystallized OO were utilized to investigate the antibacterial effects. Both Escherichia coli and Staphylococcus aureus were implicated in skin infections (with S. aureus as the primary pathogen and E. coli as the secondary pathogen) and were selected for antibacterial testing. Microcapsules applied to cultured E. coli and S. aureus resulted in different inhibition zones. Two groups [control (C-) and treatment (T-)] of second-degree burn wounds were created on the dorsal area of 15 Wistar rats. Over a period of 2 weeks, statistical analysis using a t-test demonstrated a significant reduction in the wound size in the T-zones. Histological examination with hematoxylin, eosin, and trichrome staining of tissue samples from the wound areas revealed a notable reduction in inflammation, enhanced epidermal cell proliferation, improved activity in producing hair follicles, and increased collagen deposition in the treated regions on different days of observation.

Obesity promotes urinary tract infection by disrupting urothelial immune defenses

Obesity is a significant public health concern that is associated with numerous health risks. Infections are a major complication of obesity, but the mechanisms responsible for increased infection risk are poorly defined. Here, we use a diet induced obesity mouse model and investigate how obesity impacts urinary tract infection (UTI) susceptibility and bladder immune defenses. Our results show that high-fat diet fed female and male mice exhibit increased susceptibility to uropathogenic E. coli (UPEC) following experimental UTI. Transcriptomic analysis of bladder urothelial cells shows that obesity alters gene expression in a sex-specific manner, with distinct differentially expressed genes in male and female mice, but shared activation of focal adhesion and extracellular matrix signaling. Western blot and immunostaining confirm activation of focal adhesion kinase, a central component of the focal adhesion pathway, in the bladders of obese female and male mice. Mechanistically, experiments using primary human urothelial cells demonstrate that focal adhesion kinase overexpression promotes UPEC invasion. These findings demonstrate that obesity enhances UTI susceptibility by activating focal adhesion kinase and promoting bacterial invasion of the urothelium. Together, they explain how obesity promotes UTI vulnerability and identify modifiable targets for managing obesity-associated UTI.

Significance Statement

Obesity is associated with an increased risk of urinary tract infections (UTIs), but the underlying mechanisms promoting infection susceptibility remain poorly understood. Here, we show that diet-induced obesity drives sex-specific changes in bladder urothelial gene expression, including distinct immune responses in male and female mice. Despite these differences, both sexes exhibit activation of focal adhesion kinase (FAK). FAK overexpression promotes bacterial invasion into human bladder cells. These findings provide a mechanistic explanation for obesity-associated UTI susceptibility and suggest that targeting FAK signaling could offer a therapeutic strategy to prevent UTIs, with implications for personalized interventions in obesity.

Carbon source utilization in hybrid Shiga toxin-producing and uropathogenic Escherichia coli indicates uropathogenic origin

To investigate the adaptation of hybrid Escherichia coli to the intestinal and extraintestinal milieu, we compared our model hybrid Shiga toxin-producing (STEC) and uropathogenic (UPEC) E. coli O2:H6 strains with non-pathogenic E. coli and canonical UPEC and STEC strains in a carbon source utilization assay testing 95 common carbon sources under aerobic and anaerobic conditions. Comparison of anaerobic to aerobic growth showed a 2-fold decrease and 2.5-fold increase in the growth capacity and lag phase, respectively. While the UPEC and STEC/UPEC hybrids retained the utilization of several organic acids, amino acids, and peptides, the STEC and non-pathogenic strains relied almost exclusively on the utilization of sugar compounds under anaerobic conditions. Cluster analysis indicated a higher degree of difference and separation between all strains under aerobic conditions. The UPEC, hybrids, and STEC strain B2F1 showed high similarities in aerobic carbon utilization following growth patterns observed in previous phenotype assays. Additionally, we observed known UPEC virulence traits, such as the aerobic utilization of D-serine in our model STEC/UPEC hybrids. Combined, these findings suggest that the intestinal STEC/UPEC O2:H6 isolates originated from a UPEC background and acquired the ability to cause intestinal disease with the addition of Shiga toxin as a virulence factor.

Evaluating the Effect of an Essential Oil Blend on the Growth and Fitness of Gram-Positive and Gram-Negative Bacteria

The increasing prevalence of antibiotic-resistant bacteria has necessitated the exploration of alternative antimicrobial agents, particularly natural products like essential oils. This study investigated the antibacterial potential of a unique blend of four essential oils (EOB) across a gradient of concentrations (0.1 to 50%) against Gram-positive and Gram-negative bacteria using an adapted broth microdilution method, minimum inhibitory concentrations (MICs), and 24-h growth assays. The Gram-positive bacteria were Staphylococcus epidermidis and Bacillus subtilis, while the Gram-negative bacteria were Escherichia coli and Klebsiella aerogenes. The results demonstrated that the EOB exerted a concentration-dependent inhibitory effect on bacterial growth, with MICs determined at 25% for all the species tested. Growth curve analysis revealed that lower concentrations of the EOB (0.1 to 0.78%) allowed for normal bacterial proliferation, while at intermediate concentrations (1.56 to 3.13%), inconsistent trends in growth were exhibited. At higher concentrations (25 and 50%), the EOB effectively halted bacterial growth, as indicated by flat growth curves. The increase in the lag phase and the decrease in the growth rate at a sub-MIC concentration (12.5%) suggest a significant effect on bacterial adaptation and survival. Relative fitness analyses further highlighted the inhibitory effects of higher essential oil concentrations. S. epidermidis and E. coli had a significant (p < 0.05) reduction in fitness starting from the 6.25% concentration, while the other two species experienced a significant (p < 0.001) reduction in relative fitness from a concentration of 12.5%. These findings underscore the potential of this EOB as an effective antimicrobial agent, particularly in the context of rising antibiotic resistance. Furthermore, the study suggests that the EOB used in the present study could be integrated into therapeutic strategies as a natural alternative or adjunct to traditional antibiotics, offering a promising avenue for combating resistant bacterial strains.

Antibiotic resistance genes in Escherichia coli - literature review

Antimicrobial resistance threatens humans and animals worldwide and is recognized as one of the leading global public health issues. Escherichia coli (E. coli) has an unquestionable role in carrying and transmitting antibiotic resistance genes (ARGs), which in many cases are encoded on plasmids or phage, thus creating the potential for horizontal gene transfer. In this literature review, the authors summarize the major antibiotic resistance genes occurring in E. coli bacteria, through the major antibiotic classes. The aim was not only listing the resistance genes against the clinically relevant antibiotics, used in the treatment of E. coli infections, but also to cover the entire resistance gene carriage in E. coli, providing a more complete picture. We started with the long-standing antibiotic groups (beta-lactams, aminoglycosides, tetracyclines, sulfonamides and diaminopyrimidines), then moved toward the newer groups (phenicols, peptides, fluoroquinolones, nitrofurans and nitroimidazoles), and in every group we summarized the resistance genes grouped by the mechanism of their action (enzymatic inactivation, antibiotic efflux, reduced permeability, etc.). We observed that the frequency of antibiotic resistance mechanisms changes in the different groups.

Tissue geometry spatiotemporally drives bacterial infections

Epithelial tissues serve as the first line of host against bacterial infections. The self-organization of epithelial tissues continuously adapts to the architecture and mechanics of microenvironments, thereby dynamically impacting the initial niche of infections. However, the mechanism by which tissue geometry regulates bacterial infection remains poorly understood. Here, we showed geometry-guided infection patterns of bacteria in epithelial tissues using bioengineering strategies. We discovered that cellular traction forces play a crucial role in the regulation of bacterial invasive sites and marginal infection patterns in epithelial monolayers through triggering co-localization of mechanosensitive ion channel protein Piezo1 with bacteria. Further, we developed precise mechanobiology-based strategies to potentiate the antibacterial efficacy in animal models of wound and intestinal infection. Our findings demonstrate that tissue geometry exerts a key impact on mediating spatiotemporal infections of bacteria, which has important implications for the discovery and development of alternative strategies against bacterial infections.

Genome-based assessment of antimicrobial resistance of Escherichia coli recovered from diseased swine in eastern China for a 12-year period

The global rise of antimicrobial resistance (AMR), driven by antibiotic use in healthcare and agriculture, poses a major public health threat. While AMR in clinical settings is well studied, there is a gap in understanding the resistance profiles of Escherichia coli from diseased livestock, particularly regarding zoonotic transmission. This study analyzes 114 E. coli isolates from diseased swine over 12 years, revealing that 99.12% were multidrug-resistant. Resistance was highest for ampicillin and amoxicillin/clavulanic acid (100%), followed by ciprofloxacin (96.49%) and tetracycline (94.74%). Furthermore, 21.05% of isolates were resistant to colistin, and 1.75% to tigecycline. A total of 76 antimicrobial resistance genes (ARGs) were identified, with mcr-1 found in 18.42%, mcr-3 in 4.39%, and tet(X4) in 1.75%. Significant co-occurrence of ARGs and plasmids suggests potential for co-selective dissemination. This study is the first to report enterotoxigenic E. coli (ETEC) strains carrying both mcr-1 and mcr-3 genes. After the 2017 colistin ban in China, mcr-1 detection rates significantly decreased, while florfenicol resistance rates increased in 2018-2021 (94.29%) compared to 2010-2017 (79.55%). This work provides valuable insights into the AMR profiles of E. coli from diseased swine and highlights trends that can inform strategies for monitoring and controlling public health risks associated with zoonotic E. coli transmission.IMPORTANCEThis study highlights the critical role of diseased and deceased swine in the spread of antimicrobial resistance (AMR), providing new insights into the transmission of resistance genes in zoonotic contexts. By analyzing E. coli from diseased swine, we identify key resistance genes such as mcr-1, mcr-3, and tet(X4), which pose significant public health risks, especially regarding last-resort antibiotics like colistin. Moreover, the study identifies novel transmission patterns of mcr genes, including ETEC strains carrying the mcr-3 gene and strains harboring both mcr-1 and mcr-3 genes. The role of plasmids in horizontal gene transfer is also revealed, facilitating rapid AMR spread across species. The long-term persistence of resistant strains highlights the challenges in controlling AMR in livestock. These findings underscore the need for enhanced surveillance and a One Health approach to mitigate AMR risks across animal, human, and environmental health.

Genomic features and pathogenicity of atypical diarrheagenic Escherichia coli from a large foodborne outbreak

An outbreak of diarrheal illness related to milk cartons served in school lunches, occurred in June 2021, involving more than 1800 cases from 25 schools. A strain of Escherichia coli OUT (OgGp9):H18 was implicated in the outbreak. This strain does not possess virulence factors typical of other E. coli pathotypes. In this study, we examined the pathogenicity of the E. coli OUT (OgGp9):H18 strain using genomic analysis and animal models. A core genome-based phylogenetic analysis revealed that this strain belongs to a clade comprising ST1380 strains and is distinct from enteroaggregative E. coli 042 and uropathogenic E. coli UMN026, which were previously considered to be phylogenetically related to this strain. In addition, the strain harbors a plasmid similar to that of atypical enterotoxigenic E. coli, encoding Coli Surface antigen CS8 and a type VI secretion system (T6SS). The strain caused mortality in mice following intraperitoneal inoculation. Marmosets inoculated orally, experienced diarrhea and long-term shedding. Curing the strain of the 103 Kbp plasmid it carries reduced mortality rates and colonization in the experimental animals, indicating that the plasmid encodes virulence factors. However, the mortality of mice treated with the plasmid-cured strain was higher than that of those treated with nonvirulent E. coli K-12, indicating that the chromosome also encodes virulence factors. Identified chromosomal virulence factors include a T6SS, the second type III secretion system in E. coli, ETT2, and the capsule gene cluster kps. These findings suggest that atypical diarrheagenic E. coli, such as the strain investigated in this study, may be the cause of foodborne illness in patients with diarrhea with an unknown cause.

Effect of feed supplementation with humic substances on phenotypic resistance profiles of Escherichia coli isolates from the ceca of broiler chickens

Humic substances (HS), natural complex-forming feed additives, are believed to reduce the bioavailability of antimicrobials to the gut microbiome, thereby limiting the emergence and spread of antimicrobial resistance in the food chain. However, this hypothesis has not yet been adequately verified experimentally. Our study was focused on the isolation of Escherichia coli (E. coli) from the ceca of 80 broiler chickens bred for 37 d under controlled conditions. Chickens in the control and experimental groups (40 broilers each) were fed standard commercial feeds, but the diet for experimental chicken was permanently supplemented with HS (99.3% feed + 0.7% HS). After slaughter and evisceration at the end of fattening period, the cecal contents of all chickens were subjected to microbiological analysis aimed at the enumeration, isolation and genotypic identification of E. coli strains by the species-specific PCR method. In total, 58 E. coli strains from control chickens and 60 strains from HS-fed chickens were tested for resistance against 19 antimicrobials using the broth microdilution method based on minimum inhibitory concentration breakpoints. Resistance to at least one antimicrobial was detected in almost 90% of E. coli isolates from control chickens, but in only 68.33% of isolates from HS-fed broilers (P < 0.01). In the experimental group, a noticeable decrease in resistance rates for ampicillin (31.78%), trimethoprim (22.88%), sulfamethoxazol (20.86%), and tetracycline (19.71%) was observed. The effect for fluorochinolones was less pronounced (0.09 ≤ P < 0.90). Feed supplementation with HS also reduced the prevalence of multidrug resistance (20.0% vs. 43.1%; P < 0.01) and led to a complete elimination of co-resistance to six and more antimicrobial classes. Additionally, no extended-spectrum beta-lactamase production could be predicted for E. coli isolates from HS-fed broilers. This is probably the first experimental study demonstrating a direct beneficial effect of HS-supplemented diet on the phenotypic resistance profiles of E. coli isolates from the ceca of commercially raised broiler chickens, showing that HS as feed additives can effectively reduce the phenotypic expression of antimicrobial resistance in E. coli.

Seaweed-derived mixed extracts exhibit immunomodulatory properties on porcine alveolar macrophages

Antimicrobial resistance is a growing global concern, prompting for antibiotic alternatives in animal production. Seaweed, abundant in bioactive compounds with anti-inflammatory properties, offers a natural substitute to synthetic compounds. Considering this, the objective of the present study was to evaluate the anti-inflammatory bioactivity of three seaweeds 1:1 combination of Ascophyllum nodosum, Palmaria palmata, and Ulva lactuca. Initially, polyphenol, flavonoid, and total phlorotannin content of the three seaweed species were assessed through colorimetric assays. Subsequently, the anti-inflammatory bioactivity was first evaluated through an inhibition protein precipitation assay and then confirmed in vitro through gene expression assays in LPS-stimulated porcine alveolar macrophages (PAMs). The evaluation of the bioactive molecules revealed a high content of TPC (1487.67 ± 40.39 and 1763.57 ± 69.01 mg TAE/100 mg of sample, respectively), as well as of TFC (95.68 ± 3.62 and 126.09 ± 7.34 mg CE/100 mg of sample) and TPhC (0.167 ± 0.02 and 0.23 ± 0.01 mg PGE/100 mg) for AN and UL, respectively. The assay for inhibiting protein precipitation disclosed that the extracts combining two algae species (ANUL, ANPP, PPUL) were more effective than the effect exhibited by each single extract. The assessment of anti-inflammatory bioactivity revealed a significant down-regulation of IL-1β and TNF-α in the algae combination extracts. In contrast, TGF-β showed an increasing trend. These findings, along with confirmation of the high content of bioactive molecules, highlight the algae's anti-inflammatory potential, making them suitable as natural alternatives to antibiotics for disease prevention in the livestock sector. Therefore, future research should explore the specific bioactive compounds and validate their efficacy in vivo to confirm their potential use in animal production.

High-Throughput Multiplex Detection of Antibiotic-Resistant Genes and Virulence Factors in Escherichia coli Using Digital Multiplex Ligation Assay

Escherichia coli causes >400,000 annual deaths in children aged <5 years worldwide, with morbidity and mortality exacerbated by antimicrobial-resistant strains. A high-throughput multiplexing assay called digital multiplex ligation assay (dMLA) was developed to detect simultaneously 43 priority genes in E. coli related to the following: antibiotic resistance (n = 19), virulence factors (n = 16), and phylogroup markers (n = 6) with controls (uidA, gapdh). Genes are detected via PCR amplification of adjacent probe pairs that ligate in the presence of target gene-specific DNA, followed by sequencing of amplicons on short-read sequencers. The assay was tested in technical replicates on 63 synthetic DNA controls, and applied to 58 E. coli, 2 Staphylococcus aureus, 2 Klebsiella pneumoniae, 1 Klebsiella oxytoca, 1 Vibrio cholera, 1 Pseudomonas lurida, and 1 Salmonella enterica isolates in duplicate. Whole-genome sequencing was used to assess specificity and sensitivity. dMLA showed 100% sensitivity and >99.9% specificity and balanced accuracy on synthetic DNA. Balanced accuracy, calculated as the average of sensitivity and specificity, accounts for imbalanced data sets where negative outcomes are significantly more prevalent than positive ones. dMLA achieved a balanced accuracy of 90% for bacterial isolates. The results underline dMLA's effectiveness in high-throughput characterization of E. coli libraries for antimicrobial resistance genes and virulence factors, leveraging sequencing for massively parallel multiplexing of gene regions on multiple samples simultaneously, and are extendable to targets beyond E. coli.

Designing live bacterial therapeutics for cancer

Humans are home to a diverse community of bacteria, many of which form symbiotic relationships with their host. Notably, tumors can also harbor their own unique bacterial populations that can influence tumor growth and progression. These bacteria, which selectively colonize hypoxic and acidic tumor microenvironments, present a novel therapeutic strategy to combat cancer. Advancements in synthetic biology enable us to safely and efficiently program therapeutic drug production in bacteria, further enhancing their potential. This review provides a comprehensive guide to utilizing bacteria for cancer treatment. We discuss key considerations for selecting bacterial strains, emphasizing their colonization efficiency, the delicate balance between safety and anti-tumor efficacy, and the availability of tools for genetic engineering. We also delve into strategies for precise spatiotemporal control of drug delivery to minimize adverse effects and maximize therapeutic impact, exploring recent examples of engineered bacteria designed to combat tumors. Finally, we address the underlying challenges and future prospects of bacterial cancer therapy. This review underscores the versatility of bacterial therapies and outlines strategies to fully harness their potential in the fight against cancer.

Development of intimin-enriched outer membrane vesicles (OMVs) as a vaccine to control intestinal carriage of Enterohemorrhagic Escherichia coli

Enterohemorrhagic Escherichia coli (EHEC) are foodborne pathogens causing severe human infections including hemorrhagic colitis and hemolytic uremic syndrome, particularly in children. Ruminants are the main reservoir of EHEC which colonize their intestinal tract through a mechanism involving the bacterial adhesin intimin. Vaccination of cattle has shown efficacy in reducing EHEC O157:H7 shedding in feces. However, most of these vaccines rely on purified proteins and/or adjuvants, making them expensive and not used by breeders. This study introduced the development of a new type of vaccine based on Outer Membrane Vesicles (OMVs) carrying the C-terminal domain of intimin (Int280). A vaccine which combines OMVs carrying luminal Int280 and OMVs displaying surface-exposed Int280 was produced using two addressing systems based on PelB peptide signal and Lpp-OmpA hybrid protein, respectively. Dot blot experiments on OMVs combined with FAS assay with bacteria confirmed the correct localization of the fusion proteins and the functionality of Lpp-OmpA-Int280, respectively. As a proof of concept, the efficiency of the mixed vaccine was tested in a mouse model using the pathogen Citrobacter rodentium which shares a similar intimin-based adhesion mechanism with EHEC. Intraperitoneal vaccination of mice, at two-week intervals with 1 μg of the mixture of OMV-Int280, elicited a strong anti-intimin IgG response. Interestingly, we observed a shortened C. rodentium fecal shedding duration in immunized mice compared to the control unvaccinated group, with significant reduction of C. rodentium colonization from day 14 (q < 0.0001) to day 18 (q = 0.0068). This OMV-Int280 vaccine therefore represents a promising candidate for the control of EHEC intestinal carriage and fecal shedding in ruminants.

Chemical synthesis of conjugation-ready tetrasaccharide repeating unit of Escherichia coli O50 O-antigen

Escherichia coli is a rod-shaped Gram-negative bacterium notorious for provoking diverse human infections. In this study, we report the first total synthesis of tetrasaccharide repeating unit of the cell wall of Gram-negative bacteria Escherichia coli O50 augmented with aminoethyl linker, employing both linear [1+1+1+1] and one-pot [1+1+2] approaches, and later one providing the better yield. As an aminoethyl linker, it can be further utilized for biological purposes; the challenging cis (1 → 4)-β-glycosidic linkage between l-rhamnose and d-glucosamine is addressed here with high stereo control.

Association of Escherichia coli pathotypes with fecal markers of enteropathy and nutritional status among underweight adults in Bangladesh

Introduction

Environmental enteric dysfunction (EED), a subclinical intestinal disorder, is characterized by chronic fecal-oral exposure to entero-pathogens and could be diagnosed by measuring non-invasive biomarkers. Escherichia coli is the one of the key bacterial enteric pathogens that drives EED, but there is a lack of information on the E. coli pathotypes in relation to the biomarkers of EED in malnourished adults. Here, we intended to measure the possible association of these pathotypes with EED biomarkers and nutritional status of adults residing in a slum in Bangladesh.

Method

Fecal samples were collected from 524 malnourished adults (BMI ≤18.5 kg/m2) living in a slum-setting in Dhaka from March 2016 to September 2019 and analyzed by TaqMan Array Card assays to evaluate the presence of E. coli pathotypes and other entero-pathogens. The multivariable linear regression model was used to assess the association.

Results

In these malnourished adults, the most prevalent pathotype of E. coli was EAEC (61.7%) and the least prevalent was STEC (6.7%). The prevalence of atypical EPEC, ETEC and Shigella/EIEC were 52%, 48.9% and 45.1% respectively. The infection with atypical EPEC had significant positive association with levels of Myeloperoxidase (b = 0.38; 95% CI = 0.11, 0.65; p-value = 0.006). Similarly, a significantly higher concentration of alpha-1-antitrypsin (b = 0.13; 95% CI = 0.03, 0.22; p-value = 0.011) was found in the STEC-infected adults. However, no notable association was found between the E. coli pathotypes and nutritional status of these adult participants. Moreover, Plesiomonas infected adults were more likely to be infected with EAEC (p-value = 0.017), ETEC (p-value <0.001) and STEC (pvalue = 0.002). Significant coinfection was also detected among the pathotypes and other entero-pathogens such as Giardia, Ascaris, Campylobacter, Salmonella, Enterocytozoon bieneusi, and Adenovirus.

Discussion

The study results imply that there is an influence of particular E. coli pathotypes (EPEC and STEC) on intestinal inflammation and gut permeability of the malnourished Bangladeshi adults, but no association with nutritional status is found. Potential pathogenicity of the E. coli pathotypes is also observed when co-infection with other pathogens exists in these adults.

Gut microbiome differences in children with Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder and effects of probiotic supplementation: A randomized controlled trial

BACKGROUND

Emerging evidence suggests a significant role of gut microbiota on neurodevelopmental disorders, including Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD).

AIMS

Our study aimed to compare gut microbiota composition between these disorders and evaluate the effect of probiotic supplementation.

METHODS

We conducted a 12-week randomized, double-blind, placebo-controlled trial with 80 children aged 5-14 years (39 with ADHD, 41 with ASD). Baseline and post-intervention fecal samples were analyzed using 16S rRNA gene sequencing to identify changes in gut microbiota composition.

RESULTS

We identified 22 taxa differentiating ADHD and ASD (AUC = 0.939), characterised by increased presence of Clostridia, Ruminococcaceae, and Lachnospiraceae in ADHD, and Bacteroides, Bacilli and Actinobacteria in ASD. These differences remained after accounting for potential confounders. ASD children receiving probiotics had significant increases in Chao 1, Fisher's alpha, and Shannon indices whereas no significant differences in α and β-diversity were found in ADHD. In ADHD, bacteria with potential adverse effects were under-represented. In ASD, the abundance of Eggerthellaceae, and other taxa associated with gastrointestinal problems and anxiety was decreased.

CONCLUSION

Variations in gut microbiota may influence responses in ADHD and ASD. Probiotic supplementation favorably altered gut microbiota composition, offering insights for future therapeutic strategies targeting the microbiome in neurodevelopmental disorders.

WHAT THIS PAPER ADDS

Recent research underscores the role of gut microbiota in ADHD and ASD, indicating that diet can significantly influence microbiota composition and potentially manage these neurodevelopmental disorders. This study reveals distinct differences in gut microbiota composition between children with ADHD and ASD and demonstrates that probiotic supplementation can modulate specific microbial genera in each disorder. These findings pave the way for the development of innovative microbiome-targeted therapies, offering a new avenue for the treatment of neurodevelopmental disorders. Understanding this relationship is crucial for designing future interventions.

Transcriptional response study of auto inducer-2 regulatory system in Escherichia coli harboring blaNDM

BACKGROUND

The emergence of carbapenem resistance in gram-negative bacteria such as Escherichia coli is one of the world's most urgent public health problems. E. coli, which encounter a diverse range of niches in host can rapidly adapt to the changes in surrounding environment by coordinating their behavior via production, release and detection of signal molecules called autoinducers through a cell density dependent communication system known as quorum sensing. Here, in this study we investigated whether imipenem, and acyl homoserine lactone quorum sensing signal molecules influence the transcriptional response within lsr and lsrRK operon which are associated with auto inducer-2 mediated quorum sensing in E. coli. Two E. coli isolates carrying blaNDM were treated with 10% SDS for 20 consecutive days, resulting in the successful elimination of the blaNDM encoding plasmid from one isolate. Plasmid was extracted from the isolate and was transformed into recipient E. coli DH5α by electroporation. The native type, plasmid-cured type, transformant, and E. coli DH5α were allowed to grow under eight different inducing conditions and the transcriptional responses of lsr and lsrRK operons were studied by quantitative real-time PCR method.

RESULTS

The findings of this study highlight the distinct effects of imipenem and AHL on the transcriptional responses of the lsrB,lsrR, and lsrK genes in native type, plasmid cured type, transformant, and E. coli DH5α.

CONCLUSION

This study provides a basis for further research to elucidate different inducing conditions including antibiotics and autoinducers that could switch on the quorum sensing circuit in carbapenem non-susceptible E. coli, one of the world's most urgent public health threats.

Structural elucidation of the O-antigen polysaccharide from shigatoxin-producing E. coli O179 using genetic information, NMR spectroscopy and the CASPER program

The serological properties of the O-antigen polysaccharide region of the lipopolysaccharides are used to differentiate E. coli strains into serogroups. In this study, we report the structure elucidation of the O-specific chain of E. coli O179 using NMR data, the program CASPER and analysis of biosynthetic information available in the E. coli O-antigen Database (ECODAB). The presence of genes that encode enzymes involved in the biosynthesis of the GDP-Man and UDP-GlcA within the O-antigen gene cluster of the bacteria indicates that the corresponding residues could be present in the polysaccharide. Furthermore, the occurrence of four genes that encode for glycosyltransferases indicates that the polysaccharide is composed of pentasaccharide repeating units; a bioinformatics approach based on predictive glycosyltransferase functions present in ECODAB revealed that the β-d-Manp-(1→4)-β-d-Manp-(1→3)-d-GlcpNAc structural element could be present in the O-specific chain. NMR spectroscopy data obtained from homonuclear and heteronuclear 2D NMR spectra (1H,1H-TOCSY, 1H,13C-HSQC, 1H,13C-H2BC and 1H,13C-HMBC) were analyzed using the CASPER program, revealing the following arrangement of monosaccharide residues as the most probable structure: →4)-α-d-GlcpA-(1→3)-[β-d-Glcp-(1→2)]β-d-Manp-(1→4)-β-d-Manp-(1→3)-β-d-GlcpNAc-(1→, which was further confirmed using 2D homonuclear 1H,1H-COSY and 1H,1H-NOESY spectra. The functions of the α-gluconosyltransferase and the β-glucosyltransferase were predicted using structural alignment of AlphaFold-predicted 3D structures. This O-antigen polysaccharide shares structural similarities with those of E. coli O6 and O188, S. boydii type 16, and the capsular polysaccharide of E. coli K43, explaining the serological cross-reactivities observed with strains belonging these O- and K-antigen groups.

Engineering a Biohybrid System to Link Antibiotic Efficacy to Membrane Depth in Bacterial Infections

Treating bacterial infections is dependent upon their site within a biological system, where the cumulative role of membrane transport is challenging to resolve. In this work, a cultivation method based on droplet interface bilayers (DIBs) is established. The architecture of infections in both cellular and tissue contexts is crafted where individual droplets serve as artificial cells infected by intracellular bacteria, or as interconnected units in a tissue-like structure. Through spatio-temporal control over droplets, addition, withdrawal, and sequential antibiotic gradients are tailored acting upon living bacteria. With droplet networks mimicking tissues, it is showed that the treatment response is dependent on the number of the cell-like barriers, corresponding to the number of membranes from an antibiotic source, here described as the membrane depth. Through mathematical modelling a correlation is revealed between the membrane depth of each bacterial population, the antibiotic distribution and thus the treatment efficacy. Ultimately, this approach holds promise as an in vitro bioassay for understanding the response of intracellular bacteria to antibiotics, developing new antibiotics, designing biologically inspired materials, and underpinning emerging bioprinting approaches.

Evaluation of the safety and probiotic properties of Limosilactobacillus fermentum BGI-AF16, a uric acid-lowering probiotic strain

Some beneficial microorganisms in the intestine have the potential to degrade uric acid, offering a novel strategy for the prevention of hyperuricemia. In this study, the safety and probiotic potentials of Limosilactobacillus fermentum BGI-AF16 were evaluated by whole genome sequence analysis and in vitro experiments. Based on the gene analysis of antibiotic resistance and virulence factors, L. fermentum BGI-AF16 has been shown to be safe. We identified probiotic-related genes by genome annotation tools and conducted in vitro experiments to evaluate the ability of L. fermentum BGI-AF16 to inhibit pathogenic bacteria, tolerate a simulated gastrointestinal environment, and degrade uric acid. The results from in vitro experiments showed that L. fermentum BGI-AF16 had inhibitory effects on four clinically relevant pathogens and was highly tolerant to the gastrointestinal environment. In addition, L. fermentum BGI-AF16 was able to rapidly degrade uric acid within the first hour, and the strain could degrade 56.36 ± 2.32 % of uric acid by the third hour. The genome of the strain contains genes encoding flavin adenine dinucleotide (FAD)-dependent urate hydroxylase (EC.1.14.13.113), an enzyme that directly metabolizes uric acid. And the strain has a complete uric acid metabolic pathway. These results suggest that L. fermentum BGI-AF16 is a probiotic candidate with significant potential for reducing uric acid level.

Multidrug-Resistant Uropathogens in Companion Animals: A Comprehensive Study from Clinical Cases and a Genomic Analysis of a CTX-M-14-Producing Escherichia coli ST354, a Leading Cause of Urinary Tract Infections

Urinary tract infections (UTIs) are common in small animals, posing significant clinical challenges due to their recurrence and discomfort. This study investigated the bacterial causes and antimicrobial resistance patterns of UTIs in dogs and cats presented to an important Veterinary Teaching Hospital in São Paulo, Brazil, the largest city in Latin America. Samples were collected from 31 dogs and 9 cats via ultrasound-guided cystocentesis. Bacterial cultures were performed, species identification was accomplished with matrix-assisted laser desorption ionization-time of flight mass spectrometry, and antimicrobial susceptibility testing was done using the Kirby-Bauer method. Escherichia coli was the most frequently isolated pathogen, accounting for 27.9% of cases, followed by Staphylococcus pseudintermedius, Proteus mirabilis, and Klebsiella pneumoniae. Ampicillin resistance was observed in 70.4% of enterobacteria, with many E. coli strains exhibiting multidrug resistance. Whole-genome sequencing of an extended-spectrum beta-lactamase-producing uropathogenic Escherichia coli strain from a feline patient was performed; it was identified as ST354, a leading cause of UTIs worldwide in humans and animals, carrying the blaCTX-M-14 gene and other resistance determinants. Phylogenetic analysis indicated genetic proximity between this strain and others from Brazilian poultry and environmental sources. These findings emphasize the need for antimicrobial resistance surveillance in veterinary UTIs and advocate for stricter antibiotic stewardship to inform diagnostic and therapeutic approaches within a One Health perspective.

In vitro assays for clinical isolates of sequence type 131 Escherichia coli do not recapitulate in vivo infectivity using a murine model of urinary tract infection

Sequence type 131 isolates are a major cause of cystitis and pyelonephritis. Many studies rely solely on in vitro assays to screen for bacterial virulence factors associated with the pathogenicity of clinical isolates of Escherichia coli. Few studies have compared in vitro findings with in vivo infectivity of clinical isolates. The purpose of this study was to evaluate the correlation between in vitro assays with the ability to cause cystitis and pyelonephritis in a murine model of urinary tract infection. In vitro assays were conducted according to the published protocols and included motility assays, biofilm formation, epithelial cell adhesion and invasion, and curli production. Twenty-one uropathogenic E. coli (UPEC) isolates of E. coli ST131 and non-ST131 were used for both in vivo and in vitro studies. Six mice per isolate were inoculated via urethral catheterization. Colony forming units (CFUs) were determined from bladder and kidneys. In vitro and in vivo correlations were evaluated by multiple linear regression analysis. Pairwise linear regressions showed trendlines with weak positive correlations for motility, adhesion, and invasion and weak negative correlations for hemagglutination, biofilm, and curli production. The ability of E. coli ST131 and non-ST131 clinical isolates to cause cystitis and pyelonephritis varied among strains. The R2 Pearson correlation value was less than ±0.5 for any pair, indicating little to no statistical association between in vitro and in vivo findings. These data show that in vitro data are not predictive of the ability of ST131 E. coli to infect and/or cause disease in a mouse model.

IMPORTANCE

Urinary tract infections (UTIs) affect 150 million people annually, and E. coli ST131, a pandemic clone, has become responsible for a significant portion of those UTIs. How ST131 E. coli has become such a successful strain remains to be elucidated. When evaluating bacterial pathogenicity, it is customary to use in vitro assays to predict isolate virulence and fitness due to lower cost and ease of experimentation compared with in vivo models. It is common to use model organisms like pathogenic E. coli CFT073 or a non-pathogenic K12 lab strain as representatives for the entire species. However, our research has shown that model organisms differ from ST131 E. coli, and in vitro assays are poor predictors of ST131 isolate infectivity in a murine model of UTI. As such, research into the mechanisms of fitness/pathogenesis for ST131 infectivity needs to focus on these organisms rather than other types of UPEC.

A Mysterious Health Crisis in Aswan Governorate, Southern Egypt, September 2024: A Case Report

In September 2024, the Egyptian Health Ministry declared an Escherichia coli (E. coli) outbreak in the southern province of Aswan. The spread of an ambiguous illness erupted in the village of Abu Al-Rish Bahri, 20 kilometers north of Aswan, with hundreds of citizens arriving at the governorate's local hospitals suffering from severe gastrointestinal infections. The authorities, however, did not trace the outbreak's most common source nor determine whether it was food- or water-borne. The official explanations for the frequent cases and the reported fatalities were inconclusive. There was an evident lack of comprehensive documentation on the extent of the infection, the exposed population, the prevalence pattern of the pathogen, or the retrieved E. coli isolates. In addition, the Egyptian government denied any possible association between the contamination of drinking water and the recent Aswan crisis. Challenging the official narrative, this article proposes a scientific report based on featuring the status of E. coli infection in Egypt, highlighting the gaps in the announced outbreak claims and adapting water pollution as an alarming hypothesis for the peculiar Aswan disease.

A Bioconjugate Vaccine Against Extra-Intestinal Pathogenic Escherichia coli (ExPEC)

Background: Extra-intestinal pathogenic Escherichia coli (ExPEC) represents a major global public health challenge due to its ability to cause diverse clinical infections, including urinary tract infections, bacteremia, neonatal meningitis, and sepsis. The growing prevalence of multidrug-resistant (MDR) ExPEC strains, which rapidly erode antibiotic efficacy, underscores vaccine development as a critical priority. Bioconjugate vaccines have emerged as a promising approach to mitigate ExPEC-associated infections. Methods and Results: In this study, we utilized protein glycan coupling technology (PGCT) based on oligosaccharyltransferase (OST) PglL to engineer a tetravalent bioconjugate vaccine targeting four predominant ExPEC serotypes (O1, O2, O6, and O25). We conducted a series of experiments to demonstrate the efficacy of the conjugate vaccine in eliciting humoral immune responses and inducing the production of specific antibodies against Escherichia coli O1, O2, O6, or O25 serotypes. Conclusions: This work establishes the first application of the O-linked PGCT system for engineering bioconjugate vaccines against ExPEC infections.

Molecular Characterization of Gram-Negative Bacilli Isolated from a Neonatal Intensive Care Unit and Phenotypic and Molecular Detection of ESBL and Carbapenemase

INTRODUCTION

The increase in the rates of multidrug-resistant bacteria in healthcare environments has been recognized as a global public health problem. In view of the scarcity of data on the neonatal population, this study aimed to provide information on the genotypic and epidemiological characteristics of Gram-negative microorganisms isolated from colonization and infection sites in neonates admitted to a tertiary university center of high complexity.

METHODS

Enterobacterales and non-fermenting Gram-negative bacilli previously collected in a prospective cohort study were submitted to genotypic identification, detection of extended-spectrum β-lactamases (ESBL), carbapenemases and biofilm production, detection of specific virulence markers in Pseudomonas aeruginosa, and typing by pulsed-field gel electrophoresis.

RESULTS

The data found here revealed higher rates of infection by Klebsiella spp. and Serratia marcescens that caused bloodstream infection and pneumonia, respectively. In this study, high biofilm production was observed, with 95.0% of Enterobacterales and 100% of non-fermenting Gram-negative bacilli being producers. Most of the P. aeruginosa isolates carried pathogenicity factors such as alginate, hemolytic phospholipase C, exotoxin A, and rhamnolipids. The phenotypic analysis of ESBL revealed that 16 (5.3%) isolates produced these enzymes. Four of these isolates (66.7%) carried the CTX-M-9 gene, three (50%) carried the TEM gene, and one (16.7%) was positive for the SHV and CMY-2 genes. Univariate and multivariate Cox regression analyses were used to identify risk factors for colonization and infection by Gram-negative microorganisms. The results of multivariate analysis revealed that biofilm production by these microorganisms was associated with the persistence of colonization by the same pathogen in the newborn and increased by 75% the daily probability of the newborn developing infection. The production of ESBL also increased the daily probability of infection by 46.8 times.

CONCLUSIONS

Enterobacterales showed average biofilm production, while the majority of non-fermenting Gram-negative bacilli were strong producers. The present data increase our knowledge of the molecular epidemiology of important Enterobacterales species, with emphasis on ESBL-producing Enterobacter cloacae and Klebsiella pneumoniae with emerging epidemiological potential in the neonatal intensive care unit of a tertiary university hospital. Furthermore, the results highlight the need for the monitoring and implementation of control measures and for restricting the use of broad-spectrum antibiotics.

Human microbiome acquisition and transmission

As humans, we host personal microbiomes intricately connected to our biology and health. Far from being isolated entities, our microbiomes are dynamically shaped by microbial exchange with the surroundings, in lifelong microbiome acquisition and transmission processes. In this Review, we explore recent studies on how our microbiomes are transmitted, beginning at birth and during interactions with other humans and the environment. We also describe the key methodological aspects of transmission inference, based on the uniqueness of the building blocks of the microbiome - single microbial strains. A better understanding of human microbiome transmission will have implications for studies of microbial host regulation, of microbiome-associated diseases, and for effective microbiome-targeting strategies. Besides exchanging strains with other humans, there is also preliminary evidence we acquire microorganisms from animals and food, and thus a complete understanding of microbiome acquisition and transmission can only be attained by adopting a One Health perspective.

On the role of the sorting platform in hierarchical type III secretion regulation in enteropathogenic Escherichia coli

The virulence of enteropathogenic Escherichia coli (EPEC) depends on a type III secretion system (T3SS), a membrane-spanning apparatus that injects effector proteins into the cytoplasm of target enterocytes. The T3SS, or injectisome, is a self-assembled nanomachine whose biogenesis and function rely on the ordered secretion of three distinct categories of proteins: early, middle, and late type III substrates. In EPEC, this hierarchical secretion is assisted by several cytosolic protein complexes at the base of the injectisome. Among these, the sorting platform is involved in the recognition and sequential loading of the different classes of T3-substrates. In addition, a heterotrimeric gatekeeper complex, also known as a molecular switch, operates in concert with components of the T3SS export apparatus to guarantee the delivery of middle substrates prior to late substrate secretion. In this study, we showed that the sorting platform is differentially required for the secretion of distinct categories of substrates. Moreover, we demonstrated a cooperative interplay and protein-protein interactions between the sorting platform and the gatekeeper complex for proper middle and late substrate docking and secretion. Overall, our results provide new insights into the intricate molecular mechanisms that regulate protein secretion hierarchy during T3SS assembly.IMPORTANCEEnteropathogenic Escherichia coli employs a type III secretion system to deliver virulence proteins directly into host cells, disrupting multiple cellular processes to promote infection. This multiprotein system assembles in a precise stepwise manner, with specific proteins being recruited and secreted at distinct stages. The sorting platform and the gatekeeper complex play critical roles in regulating this process, but their cooperative mechanism has not been fully elucidated. Here, we reveal a novel functional interaction between these two components, which is critical for hierarchical substrate recognition and secretion. These findings advance our understanding of the molecular mechanisms underlying bacterial virulence and suggest new potential targets for antimicrobial strategies aimed at disrupting T3SS function.

Synthesis, in silico and in vitro antimicrobial efficacy of some amidoxime-based benzimidazole and benzimidamide derivatives

Amidoximes are employed as building blocks to synthesise heterocyclic motifs with biological significance. They are very reactive and are used as prodrugs of amidine. This present study unveils the synthesis of amidoxime-based benzimidazole and benzimidamide motifs and evaluates their in silico and in vitro antimicrobial potential as future drug candidates. The compounds (2a, 2b, 4a-c) were synthesized using multi-step synthetic pathways. The synthesised compounds were characterised using physico-chemical examination, 1H- and 13C-NMR, DEPT-135, and FT-IR spectroscopic analyses. The in silico antimicrobial potentials of the synthesized compounds were carried out against glucosamine-6-phosphate synthase of E. coli (PDB ID: 2VF5), and N-myristoyltransferase (NMT) of C. albicans (PDB ID: 1IYL), while the in vitro antimicrobial screening was investigated against selected bacteria and fungi. The in silico studies were carried out using predicted ADMET screening, molecular docking, MM-GBSA, induced-fit docking (IFD), and molecular dynamics (MD) simulation studies. Furthermore, the in vitro experimental validations were performed using the agar diffusion method and the standard antibacterial and antifungal drugs used were gentamicin and ketoconazole respectively. The predicted toxicity test of the compounds showed no significant risk, except for 4c, which showed high tumorigenic risk. Compounds 2b and 2a gave better binding energies; -8.0 kcal mol-1 for 2VF5 and -11.7 kcal mol-1 for 1IYL, respectively. The antimicrobial zone of inhibition and minimum inhibitory concentration values were 40 mm and 3.90 mg mL-1 against S. mutans, then 42 mm and 1.90 mg mL-1 against C. albicans. Potential antimicrobial drug candidates have been identified in this report and should be explored for future preclinical research.

Pinosylvin: A Multifunctional Stilbenoid with Antimicrobial, Antioxidant, and Anti-Inflammatory Potential

Stilbenoids are a category of plant compounds exhibiting notable health-related benefits. After resveratrol, perhaps the most well-known stilbenoid is pinosylvin, a major phytochemical constituent of most plants characterised by the pine spines among others. Pinosylvin and its derivatives have been found to exert potent antibacterial and antifungal effects, while their antiparasitic and antiviral properties are still a subject of ongoing research. The antioxidant properties of pinosylvin are mostly based on its scavenging of free radicals, inhibition of iNOS and protein kinase C, and promotion of HO-1 expression. Its anti-inflammatory properties are based on a variety of mechanisms, such as COX-2 inhibition, NF-κB and TRPA1 activation inhibition, and reduction in IL-6 levels. Its anticancer properties are partly associated with its antioxidant and anti-inflammatory potential, although a number of other mechanisms are described, such as apoptosis induction and matrix metalloproteinase inhibition. A couple of experiments have also suggested a neuroprotective potential. A multitude of ethnomedical and ethnobotanical effects of pinosylvin-containing plants are reported, like antimicrobial, antioxidant, anti-inflammatory, hepatoprotective, and prokinetic actions; many of these are corroborated by recent research. The advent of novel methods of artificial pinosylvin synthesis may facilitate its mass production and adoption as a medical compound. Finally, pinosylvin may be a tool in promoting environmentally friendly pesticide and insecticide policies and be used in land remediation schemes.

Genomic approach to evaluate the intrinsic antibacterial activity of novel diazabicyclooctanes (zidebactam and nacubactam) against clinical Escherichia coli isolates from diverse clonal lineages in the United Arab Emirates

BACKGROUND

The spiking rise in the prevalence of multidrug-resistant (MDR) pathogens necessitates discovering new antimicrobial agents. This study aims to investigate the intrinsic activity of two novel diazabicyclooctane (DBO) β-lactamase inhibitors, zidebactam and nacubactam, against diverse MDR Escherichia coli isolates from the United Arab Emirates. We aimed to correlate their antibacterial efficacy with the genomic characteristics of the strains.

METHODS

This study investigated 73 E. coli strains and tested them for susceptibility to different antibiotics, including DBOs. PCR screening for carbapenemase and major β-lactamase genes was done. The strains were then grouped according to phenotypic and genotypic profiles. Whole-genome sequencing was employed to characterize the genetic landscape and clonality of selected 32 strains. Additionally, time-kill studies were conducted to confirm the bactericidal activity of DBOs.

RESULTS

Zidebactam demonstrated superior efficacy compared to nacubactam, primarily due to its higher affinity for penicillin-binding protein 2 (PBP2). Notably, zidebactam alone exhibited the most potent in vitro activity, outperforming both traditional β-lactams and novel antibiotics like cefiderocol. DBOs maintained effectiveness against strains harboring various resistance determinants, including NDM-5, OXA-181, CTX-M-15, SHV-12, CMY, and DHA. Genomic analysis revealed multiple mutations in PBP1-3, with PBP2 mutations correlating with DBO susceptibility variations. Importantly, DBOs remained highly effective against isolates with PBP mutations, even those belonging to high-risk clonal lineages (ST167, ST410, ST131). Time-kill studies confirmed the bactericidal activity of DBOs, with only one strain showing reduced susceptibility (MIC: 4 µg/ml).

CONCLUSIONS

This study provides compelling evidence for the potential of DBOs, particularly zidebactam, as novel antibacterial agents. Their unique characteristics and broad-spectrum activity position them as promising candidates for future antibiotic development. While the inclusion of DBO therapies in the antibiotic arsenal could significantly impact MDR pathogen treatment, realizing their full potential requires further research, clinical evaluation, and vigilant monitoring of resistance mechanisms through integrated genomic approaches.

Cross-Sectional Study: Assessing the Presence of Stx2e-Producing E. coli Virotypes in Samples of Oral Fluid of Growers and Fatteners

Edema disease is a multifactorial infectious disease caused by specific E. coli virotypes possessing fimbriae F18 and toxin Stx2e that cause significant losses in the post-weaning period. The aim of this study was to assess the presence of Stx2e-producing E. coli verotypes in Slovenian commercial pig farms in relation to the biosecurity and technological measures undertaken by the owners. Samples of oral fluid were collected from growers and fatteners at 5-6 weeks, 7-8 weeks, 12 weeks and 14 weeks of age on 37 commercial pig farms, using the Verocheck® diagnostic kit for the real-time PCR detection of Stx2e. The results of RT-PCR and the questionnaire were statistically analyzed. The prevalence of E. coli strains producing Stx2e was 64.9%. Statistically significant association between the prevalence of Stx2e producing E. coli strains and the type of the farm and feed origin was proved. No association was found between prevalence and farm size, presence of quarantine or previous outbreaks of edema disease. None of the studied age groups showed a statistically significant dominance in prevalence compared to other age groups, which contradicts the current theoretical data. Further studies are needed to estimate the proportion of Stx2e produced by the EDEC pathotype compared to other E. coli strains.

Whole-genome sequence-based comparison of antimicrobial resistant diarrheagenic Escherichia coli in pork and chicken production chains in Korea

Diarrheagenic Escherichia coli (DEC) is a serious public health threat. We investigated the distribution, antimicrobial resistance, and molecular characteristics of DEC in pork and chicken production chains following the "One Health" approach. We collected 1567 pig- and 771 chicken-associated samples from animal farms, slaughterhouses, and retail markets. Of these samples, we identified 150 DEC isolates, with 73 (4.7 %) originating from pigs and 77 (10 %) from chickens. DEC risk of contamination in the final product (meat) was significantly higher in chickens (27.3 %) compared to pigs (0.5 %). In addition, carryover meat contamination was observed by clones originating from slaughterhouses in the chicken meat production chain. The resistance of chicken-associated isolates compared to pig-associated isolates to most antimicrobial agents was higher. Phylogenetic analysis following whole-genome sequencing of 150 DEC showed distinct lineages based on the host species, resulting in 20 clusters and 16 singletons. Multilocus sequence typing and serotyping revealed 25 and 30 different sequence types (STs) and serotypes, respectively. Human infection-related STs, including ST10 (11 %), ST23 (2.3 %), and ST48 (6.8 %), along with serotypes O89 (12.3 %), O26 (6.8 %), O103 (5.5 %), O121 (2.7 %), and O145 (2.7 %), were commonly detected in pig-associated isolates, emphasizing a zoonotic risk. Furthermore, the presence of various plasmids containing antimicrobial resistance and virulence genes was evident, posing a risk of spreading these genes to clinically important pathogens. Therefore, implementing effective control programs to reduce the prevalence of antimicrobial-resistant DEC in food production systems is important.

Gastrointestinal Escherichia coli in men who have sex with men: A systematic review

OBJECTIVE

This systematic review aimed to explore any demographic, biological and behavioural characteristics of men who have sex with men (MSM) with diarrhoeagenic E.coli.

DESIGN/METHODS

We searched MEDLINE, EMBASE, and CINAHL for manuscripts published to March 2024. One author screened manuscript abstracts; two authors independently conducted a full text review. We only included primary data on gastrointestinal E.coli in MSM. Risk of bias was assessed independently by two authors using the Joanna Briggs Institute tools. This review was registered on PROSPERO(CRD42023455321).

RESULTS

Eleven manuscripts (cross-sectional studies (n = 8), case-series (n = 1), case-control study (n = 1), longitudinal study (n = 1)) from Europe (n = 7) Australia (n = 2), USA (n = 2) including 983 MSM with gastrointestinal E.coli published between 2014-2023 were included in this review. Demographic factors (living with HIV, using HIV-PrEP, using dating apps and working as airline crew, group sex, non-regular (casual) sexual partners); behavioural factors (non-regular sexual partners, non-condom use, oro-anal sex, penile-anal sex, use of sex toys, insertive and receptive fisting, scat play); and infection factors (co-infection with Chlamydia trachomatis including LGV, Neisseria gonorrhoeae, Treponema pallidum, hepatitis C, other enteric pathogens [Shigella spp. Giardia duodenalis, Entamoeba histolytica, hepatitis A and intestinal spirochaetosis]) were observed in MSM with E. coli. Antimicrobial resistance (extended spectrum beta-lactamase and quinolone resistance) was described in MSM with E.coli.

CONCLUSION

We have highlighted demographic, behavioral and infection factors observed in MSM with E.coli suggesting sexual transmissibility. These data provide insight for future clinical guidelines, public health control strategies and research.