Escherichia coli in Europe: an overview

Catheter-associated Urinary Tract Infections-Online Questionnaire: Status Quo in Central European Urological Management of Catheter-associated Urinary Tract Infection

Background and objective

Catheter-associated urinary tract infections (CAUTIs) represent a significant burden in health care and its management is challenging. This study aims to assess and compare central European CAUTIs regarding diagnostics, treatment, and prophylaxis.

Methods

An anonymized online questionnaire was distributed among urologists in Austria, France, Germany, and Switzerland between January and October 2023, consisting of demographic questions on catheter management and diagnostics, treatment, and prophylaxis of CAUTIs. An analysis was performed per country. Comparisons were done with the Fisher's exact test (statistical significance with p < 0.05).

Key findings and limitations

Out of 423 participating urologists, most regularly performed catheter changes and managed catheter-related issues, except for French urologists. Swiss urologists tended to change the catheter after a longer interval. In France, a higher estimated number of CAUTIs were observed. Diagnostic symptoms and measures varied significantly between countries. French urologists prescribed more antimicrobials per patient and administered longer treatment regimens. The choice of antimicrobial agents differed notably for nonfebrile and febrile CAUTIs, with cotrimoxazole/nitrofurantoin being common for nonfebrile cases and cephalosporin/amoxicillin for febrile ones. Follow-up protocols were similar among urologists, while prophylactic measures showed variations.

Conclusions and clinical implications

CAUTI management varied notably across countries in terms of diagnostics, treatment, and prophylaxis. Discrepancies in antimicrobial therapy could be influenced by local resistance rates; yet, nonrecommended drugs and prolonged regimens, as compared with guideline recommendations, were common. This trend, along with inappropriate diagnostics and prophylaxis, may increase antimicrobial resistance and CAUTI morbidity. This study emphasizes the necessity for diagnostic and antimicrobial stewardship interventions, and proper training in CAUTI management.

Patient summary

In this questionnaire-based study examining the clinical practices for managing urinary tract infections in patients with bladder catheters (CAUTIs), significant disparities were observed among European urologists regarding diagnosis, treatment, and prophylaxis. These findings underscore the critical need for clear guidelines and comprehensive training in CAUTI management.

Analyzing the performance of short-read classification tools on metagenomic samples toward proper diagnosis of diseases

Accurate knowledge of the genome, virus and bacteria that have invaded our bodies is crucial for diagnosing many human diseases. The field of bioinformatics encompasses the complex computational methods required for this purpose. Metagenomics employs next-generation sequencing (NGS) technology to study and identify microbial communities in environmental samples. This technique allows for the measurement of the relative abundance of different microbes. Various tools are available for detecting bacterial species in sequenced metagenomic samples. In this study, we focus on well-known taxonomic classification tools such as MetaPhlAn4, Centrifuge, Kraken2, and Bracken, and evaluate their performance at the species level using synthetic and real datasets. The results indicate that MetaPhlAn4 exhibited high precision in identifying species in the simulated dataset, while Kraken2 had the best area under the precision-recall curve (AUPR) performance. Centrifuge, Kraken2, and Bracken showed accurate estimation of species abundances, unlike MetaPhlAn4, which had a higher L2 distance. In the real dataset analysis with samples from an inflammatory bowel disease (IBD) research, MetaPhlAn4, and Kraken2 had faster execution times, with differences in performance at family and species levels among the tools. Enterobacteriaceae and Pasteurellaceae were highlighted as the most abundant families by Centrifuge, Kraken2, and MetaPhlAn4, with variations in abundance among ulcerative colitis (UC), Crohn's disease (CD), and control non-IBD (CN) groups. Escherichia coli (E. coli) has the highest abundance among Enterobacteriaceae species in the CD and UC groups in comparison with the CN group. Bracken overestimated E. coli abundance, emphasizing result interpretation caution. The findings of this research can assist in selecting the appropriate short-read classifier, thereby aiding in the diagnosis of target diseases.

Auranofin enhances the antibacterial effects of ertapenem against carbapenem-resistant Escherichia coli

The prevalence of carbapenem-resistant Escherichia coli (CREC) is increasing worldwide, and infections caused by CREC are associated with substantial morbidity and mortality rates. It is within this context that combination therapy has been reported as an effective strategy for treating resistant bacteria. Auranofin was approved by the FDA for treating rheumatoid arthritis. We confirmed that auranofin restored the susceptibility of ertapenem to CREC through synergy checkerboard and time-kill analyses. We also demonstrated that sub-MIC levels of auranofin significantly inhibited the expression of carbapenemase (blaKPC) and efflux pump (acrA, acrD, and tolC) genes. The combination of auranofin and ertapenem suppressed the expression levels of motility (motA and flhD) genes, decreasing motility, which is a known pathogenic factor in CREC. Taken together, our results indicate that auranofin exerted a synergistic effect with ertapenem by suppressing the expression of carbapenemase and efflux pump genes and reducing the motility and virulence factors against CREC.

Escherichia coli community-acquired necrotizing pneumonia, an uncommon presentation of a common pathogen: A case report and literature review

Community-acquired necrotizing pneumonia is a rare but potentially fatal infection, mainly caused by specific pathogens such as Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa. Escherichia coli is extremely rare as a pathogen for community-acquired necrotizing pneumonia, typically accompanied with bloodstream infection. Here, we report an unusual case of a 60-year-old man with uncontrolled diabetes mellitus and no bloodstream infections, who had severe necrotizing E. coli pneumonia leading to massive hemoptysis and death. Clinicians should be aware of this pathogen in respiratory infections, as it requires immediate pathogen detection and usually aggressive antibiotic treatment.

Antibiotic Resistance Profiles of Escherichia coli and Salmonella spp. Isolated From Dairy Farms and Surroundings in a Rural Area of Western Anatolia, Turkey

Background Antibiotic resistance is a significant public health issue worldwide. Antibiotic-resistant zoonotic bacteria such as Escherichia coli (E. coli), Campylobacter, Salmonella, Listeria, Coxiella, and Mycobacterium can be particularly isolated from biofertilizers. Epidemiological studies have shown that cases of foodborne infections and intoxications are significantly related to animal-derived foods. The presence of these species in aquatic environments indicates areas or organisms contaminated with animal or human feces. Especially, the presence of E. coli in aquatic environments has become a serious problem worldwide. Pathogenic strains of E. coli cause waterborne and foodborne diseases. Materials and methods This study included a total of 290 samples collected from five different dairy farms between April and September 2023 which comprised 20 samples of cow manure, 20 samples of milk, three samples of dairy workers' hand washing water, five samples of soil, five samples of water, and five samples of vegetables. The samples taken from the farms were homogenized with 0.1% peptone water at a ratio of 1/10. They were then cultured on xylose lysine deoxycholate (XLD), eosin methylene blue agar (EMB), and blood agar media, and gram-negative colonies were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the VITEK2 automated system (BioMerieux Inc., Durham, NC). Amplification of the isolated DNA extracts was performed with A.B.T.™ 2X HS-PCR MasterMix (A.B.T Laboratory Industry, Arnavutköy, Turkey) in the SimpliAmp™ thermal cycler (Thermo Fischer Scientific Inc., Waltham, MA) and visualized by agarose gel electrophoresis. Results Among the 52 E. coli strains isolated in our study, the highest antibiotic sensitivity rate was observed in meropenem, while the lowest sensitivity rates were determined in cefazolin and cefuroxime. While two of the Salmonella spp. (n = 2) isolates were found to be resistant to tetracycline, and one was found to be resistant to penicillin and ampicillin. No resistance to trimethoprim/sulfamethoxazole was detected in either isolate. Extended-spectrum beta-lactamases (ESBLs) were detected in only four (7.7%) E. coli strains. While tetA, tetB, and TEM genes were seen in almost all E. coli strains, they were not found in Salmonella spp. Conclusion In conclusion, our study revealed the presence of antimicrobial resistance genes in E. coli and Salmonella spp. isolates collected from various farms and environmental samples, which render the antimicrobials used for disease treatment ineffective. Consequently, research should be undertaken to prevent the development of new resistance genes in our country, as creating new medications and treatment strategies for these diseases is costly and time-intensive.

The phylogroups and antibiotic susceptibilities of Escherichia coli isolates from the feces of Anatolian Ground Squirrels (Spermophilus xanthoprymnus)

The current study was conducted to determine the phylogroups and antibiotic susceptibilities of Escherichia coli isolates recovered from fecal samples of Anatolian Ground Squirrels (Spermophilus xanthoprymnus) and to examine the relationship between them. Eighty-two E. coli isolates obtained from 150 fecal samples were investigated. The quadruplex polymerase chain reaction (PCR), phylogroup C-, and E-specific mPCR were subjected to phylogenetic typing of the isolates. The susceptibilities to fifteen antibiotics of the isolates were detected by the disk diffusion method. In the result of phylogenetic typing, phylogroup B2 was most predominant (58.6 %), followed by B1 (25.6 %), E (8.5 %), C (4.9 %), and D (2.4 %). The phylogroup A, F, and Escherichia clades were not detected. The antibiotic susceptibility test revealed that 59.8 % (49/82) and 19.5 % (16/82) of E. coli isolates were resistant to at least one antibiotic and multidrug-resistant (MDR), respectively. Twenty-six (31.7 %), 19 (23.2 %), 11 (13.4 %), and 10 (12.2 %) of the isolates were found to be resistant to gentamicin, tetracycline, amoxicillin-clavulanic acid, and cefoxitin. Of the 49 E. coli isolates that were found to be resistant to any antibiotic analyzed, 30, 13, 4, and 2 were located in phylogroup B2, B1, E, and D, respectively. MDR isolates were mostly located in both phylogroup B1 (31.3 %) and B2 (31.3 %). In conclusion, data from the current study suggest that the isolates may potentially have pathogenic properties, since the majority (69.5 %) of E. coli isolates from fecal samples of Spermophilus xanthoprymnus were located in the pathogenic phylogroup and resistance to various antibiotics was detected.

The application of organoids in cancers associated with pathogenic infections

Cancers associated with pathogen infections are gradually becoming important threats to human health globally, and it is of great significance to study the mechanisms of pathogen carcinogenesis. Current mechanistic studies rely on animal and two-dimensional (2D) cell culture models, but traditional methods have been proven insufficient for the rapid modeling of diseases caused by new pathogens. Therefore, research focus has shifted to organoid models, which can replicate the structural and genetic characteristics of the target tissues or organs in vitro, providing new platforms for the study of pathogen-induced oncogenic mechanisms. This review summarizes the application of organoid technology in the studies of four pathogen-associated cancers: gastric cancer linked to Helicobacter pylori, liver cancer associated with hepatitis B virus or hepatitis C virus, colorectal cancer caused by Escherichia coli, and cervical cancer related to human papillomavirus. This review also proposes several limitations of organoid technology to optimize organoid models and advance the treatment of cancer associated with pathogen infections in the future.

Dissemination of Urinary Escherichia coli Phylogroup B2 in Provincial and Community Hospitals in Uthai Thani, Central Thailand

Escherichia coli is a Gram-negative bacterium that causes a variety of clinical infections in humans, including diarrhea, sepsis, and urinary tract infection. This bacterium is a common multidrug-resistant threat in community and hospital settings worldwide. This study examined the antimicrobial susceptibility and genetic relationship based on Clermont phylotyping and enterobacterial repetitive intergenic consensus (ERIC)-PCR of 84 E. coli urinary isolates from provincial and community hospitals in Thailand. All isolates were susceptible to nitrofurantoin, and almost all isolates were susceptible to carbapenem, fosfomycin, and amikacin. High resistance rates to fluoroquinolone, ampicillin, and trimethoprim/sulfamethoxazole were observed. Clermont phylogroup B2 was predominant (n = 58). Subtyping of the B2 phylogroup revealed diverse subgroups, of which subgroup V (n = 11), VII (n = 9), III (n = 6), and II (n = 6) were most prevalent. ERIC-PCR showed that the strains of the B2 subgroups III and V were spread between provincial and community hospitals and between hospital wards. This evidence suggests the need for comprehensive infection control monitoring, with strong active surveillance at all hospital levels.

Escherichia coli Activate Extraintestinal Antibody Response and Provide Anti-Infective Immunity

The effects of intestinal microflora on extraintestinal immune response by intestinal cytokines and metabolites have been documented, but whether intestinal microbes stimulate serum antibody generation is unknown. Here, serum antibodies against 69 outer membrane proteins of Escherichia coli, a dominant bacterium in the human intestine, are detected in 141 healthy individuals of varying ages. Antibodies against E. coli outer membrane proteins are determined in all serum samples tested, and frequencies of antibodies to five outer membrane proteins (OmpA, OmpX, TsX, HlpA, and FepA) are close to 100%. Serum antibodies against E. coli outer membrane proteins are further validated by Western blot and bacterial pull-down. Moreover, the present study shows that OstA, HlpA, Tsx, NlpB, OmpC, YfcU, and OmpA provide specific immune protection against pathogenic E. coli, while HlpA and OmpA also exhibit cross-protection against Staphylococcus aureus infection. These finding indicate that intestinal E. coli activate extraintestinal antibody responses and provide anti-infective immunity.

Extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: insights from a tertiary hospital in Southern Thailand

Broad-spectrum ampicillin-resistant and third-generation cephalosporin-resistant Enterobacteriaceae, particularly Escherichia coli and Klebsiella pneumoniae that have pathological features in humans, have become a global concern. This study aimed to investigate the prevalence, antimicrobial susceptibility, and molecular genetic features of extended-spectrum beta-lactamase (ESBL)-producing E. coli and K. pneumoniae isolates in Southern Thailand. Between January and August 2021, samples (n = 199) were collected from a tertiary care hospital in Southern Thailand. ESBL and AmpC-lactamase genes were identified using multiplex polymerase chain reaction (PCR). The genetic relationship between ESBL-producing E. coli and K. pneumoniae was determined using the enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction. ESBL-producing E. coli and K. pneumoniae isolates were mostly collected from catheter urine samples of infected female patients. The ESBL production prevalence was highest in the medical wards (n = 75, 37.7%), followed by that in surgical wards (n = 64, 32.2%) and operating rooms (n = 19, 9.5%). Antimicrobial susceptibility analysis revealed that all isolates were resistant to ampicillin, cefotaxime, ceftazidime, ceftriaxone, and cefuroxime; 79.4% were resistant to ciprofloxacin; and 64.3% were resistant to trimethoprim-sulfamethoxazole. In ESBL-producing K. pneumoniae and E. coli, blaTEM (n = 57, 72.2%) and blaCTX-M (n = 61, 50.8%) genes were prominent; however, no blaVEB, blaGES, or blaPER were found in any of these isolates. Furthermore, only ESBL-producing K. pneumoniae had co-harbored blaTEM and blaSHV genes at 11.6%. The ERIC-PCR pattern of multidrug-resistant ESBL-producing strains demonstrated that the isolates were clonally related (95%). Notably, the presence of multidrug-resistant and extremely resistant ESBL producers was 83.4% and 16.6%, respectively. This study highlights the presence of blaTEM, blaCTX-M, and co-harbored genes in ESBL-producing bacterial isolates from hospitalized patients, which are associated with considerable resistance to beta-lactamase and third-generation cephalosporins.

IMPORTANCE

We advocate for evidence-based guidelines and antimicrobial stewardship programs to encourage rational and appropriate antibiotic use, ultimately reducing the selection pressure for drug-resistant bacteria and lowering the likelihood of ESBL-producing bacterial infections.

Significant reduction of the culturing time required for bacterial identification and antibiotic susceptibility determination by infrared spectroscopy

Rapid testing of bacteria for antibiotic susceptibility is essential for effective treatment and curbing the emergence of multidrug-resistant bacteria. The misuse of antibiotics, coupled with the time-consuming classical testing methods, intensifies the threat of antibiotic resistance, a major global health concern. In this study, employing infrared spectroscopy-based machine learning techniques, we significantly shortened the time required for susceptibility testing to 10 hours, a significant improvement from the 24 hours in our previous studies as well as the conventional methods that typically take at least 48 hours. This remarkable reduction in turnaround time (from 48 hours to 10 hours), achieved by minimizing the culturing period, offers a game-changing advantage for clinical applications. Our study involves a dataset comprising 400 bacterial samples (200 E. coli, 100 Klebsiella pneumoniae, and 100 Pseudomonas aeruginosa) with an impressive 96% accuracy in the taxonomic classification at the species level and up to 82% accuracy in bacterial susceptibility to various antibiotics.

Multi- and extensively drug resistant Escherichia coli isolated from South African children under 5 years old with diarrhoea

BACKGROUND

Globally, millions of children die as a result of diarrhoea and/or antimicrobial resistant infections. Diarrhoeagenic Escherichia coli (DEC) are responsible for a substantial proportion of cases of diarrhoea in South Africa and sub-Saharan Africa. Effective treatments (including the use of antimicrobials) are therefore essential.

METHODOLOGY

E. coli isolated from children under the age of five were subjected to antimicrobial susceptibility testing using the Vitek 2® compact automated system (bioMérieux Inc., France) and categorized as multidrug or extensively drug resistant (MDR or XDR).

RESULTS

Almost all isolates (164/166, 98.8 %) were categorized as MDR with 4.9 % (9/166) categorized as XDR. The majority of isolates (153/166, 92.2 %) were also phenotypically classified as extended-spectrum β-lactamase (ESBL) producers. More than half of these isolates (78/153, 51.0 %) were subjected to PCR for genes associated with ESBL production. More than half (45/78, 57.7 %) of the isolates tested were PCR positive for at least one ESBL gene or gene group and 11.5 % (9/78) were positive for two ESBL genes or gene groups.

DISCUSSION

There is a need to strengthen antimicrobial resistance surveillance in South Africa and improve infection prevention and control measures. There is also a need to review the current South African Treatment Guidelines as outlined by the South African Essential Drugs Programme.

Multidrug-resistant Escherichia coli strains isolated from swine manure biofertilizer in Brazil

Escherichia coli is one of the key bacteria responsible for a variety of diseases in humans and livestock-associated infections around the globe. It is the leading cause of mortality in neonatal and weaned piglets in pig husbandry, causing diarrhea and significant harm to the industry. Furthermore, the frequent and intensive use of antimicrobials for the prevention of diseases, particularly gastrointestinal diseases, may promote the selection of multidrug-resistant (MDR) strains. These resistant genotypes can be transmitted through the excrement of animals, including swine. It is common practice to use porcine manure processed by biodigesters as fertilizer. This study aimed to examine the antimicrobial susceptibility, the presence of virulence genes frequently associated with pathotypes of intestinal pathogenic E. coli (InPEC), and antimicrobial resistance genes (ARGs) of 28 E. coli isolates collected from swine manure fertilizers. In addition, the enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) technique was used to investigate the genetic relationship among the strains. Using disk diffusion, the antimicrobial susceptibility profiles of the strains were determined. Using polymerase chain reaction (PCR), 14 distinct virulence genes associated with the most prevalent diarrhea and intestinal pathogenic E. coli (DEC/InPEC) and five ARGs were analyzed. All isolates tested positive for multidrug resistance. There was no detection of any of the 14 virulence genes associated with InPECs, indicating the presence of an avirulent commensal microbiota. Molecular classification by ERIC-PCR revealed that the majority of isolates (27 isolates) coalesced into a larger cluster with a genetic similarity of 47.7%; only one strain did not cluster in this cluster, indicating a high level of genetic diversity among the analyzed isolates. Thus, it is of the utmost importance to conduct epidemiological surveillance of animal breeding facilities in order to determine their microbiota and formulate plans to reduce the use of antimicrobials and improve animal welfare.

Ferrous gluconate triggers ferroptosis in Escherichia coli: Implications of lipid peroxidation and DNA damage

Microbial ferroptosis has been proved to combat drug-resistant pathogens, but whether this pattern can be applied to the prevention and control of Escherichia coli remains to be further explored. In this study, ferrous gluconate (FeGlu) showed remarkable efficacy in killing E. coli MG1655 with a mortality rate exceeding 99.9%, as well as enterotoxigenic E. coli H10407 (ETEC H10407) and enterohemorrhagic E. coli O157:H7 (EHEC O157:H7). Bacteria death was instigated by the infiltration of Fe2+, accompanied by a burst of intracellular reactive oxygen species (ROS) and lipid peroxidation. Notably, mitigating lipid peroxidation failed to alleviate death of E. coli. Further findings confirmed that FeGlu induced DNA damage, and ΔrecA mutant showed more sensitive, implicating that DNA damage was involved in the death of E. coli. The direct interaction of Fe2+ with DNA was demonstrated by fluorescent staining, gel electrophoresis, and circular dichroism (CD). Moreover, proteomic analysis unveiled 50 differentially expressed proteins (DEPs), including 18 significantly down-regulated proteins and 32 significantly up-regulated proteins. Among them, the down-regulation of SOS-responsive transcriptional suppressor LexA indicated DNA damage induced severely by FeGlu. Furthermore, FeGlu influenced pathways such as fatty acid metabolism (FadB, FadE), iron-sulfur cluster assembly (IscA, IscU, YadR), iron binding, and DNA-binding transcription, along with α-linolenic acid metabolism, fatty acid degradation, and pyruvate metabolism. These pathways were related to FeGlu stress, including lipid peroxidation and DNA damage. In summary, FeGlu facilitated ferroptosis in E. coli through mechanisms involving lipid peroxidation and DNA damage, which presents a new strategy for the development of innovative antimicrobial strategies targeting E. coli infections.

Bionic Nanocoating of Prosthetic Grafts Significantly Reduces Bacterial Growth

Prosthetic materials are a source of bacterial infections, with significant morbidity and mortality. Utilizing the bionic "Lotus effect," we generated superhydrophobic vascular prostheses by nanocoating and investigated their resistance to bacterial colonization. Nanoparticles were generated from silicon dioxide (SiO2), and coated vascular prostheses developed a nanoscale roughness with superhydrophobic characteristics. Coated grafts and untreated controls were incubated with different bacterial solutions including heparinized blood under mechanical stress and during artificial perfusion and were analyzed. Bioviability- and toxicity analyses of SiO2 nanoparticles were performed. Diameters of SiO2 nanoparticles ranged between 20 and 180 nm. Coated prostheses showed a water contact angle of > 150° (mean 154 ± 3°) and a mean water roll-off angle of 9° ± 2°. Toxicity and viability experiments demonstrated no toxic effects of SiO2 nanoparticles on human induced pluripotent stem cell-derived cardiomyocytes endothelial cells, fibroblasts, and HEK239T cells. After artificial perfusion with a bacterial solution (Luciferase+ Escherichia coli), bioluminescence imaging measurements showed a significant reduction of bacterial colonization of superhydrophobic material-coated prostheses compared to that of untreated controls. At the final measurement (t = 60 min), a 97% reduction of bacterial colonization was observed with superhydrophobic material-coated prostheses. Superhydrophobic vascular prostheses tremendously reduced bacterial growth. During artificial perfusion, the protective superhydrophobic effects of the vascular grafts could be confirmed using bioluminescence imaging.

Antibiotic Profiling of E. coli Borne UTI Infection in Tertiary Healthcare Settings

Introduction In general, with frequent recurrence of urinary tract infections (UTIs), long-term antibiotic therapy is stipulated at a low dose. With this type of situation and with easy access to several classes of antibiotics in tertiary health care settings, the use of such drugs results in the development of resistant bacteria in patients. Escherichia coli is a frequent cause of UTI observed. Hence, it was proposed in the present study to assess the antimicrobial resistance status of E. coli in UTI-infected patients. Methods This study was conducted among female patients diagnosed with UTI. About 80 urine samples were collected in an aseptic condition, Under the process of culture identification 44 samples were found to be positive for UTI infection. The positive samples were plated on blood agar. Out of 44 samples, 18 samples were found to be positive, and 26 samples were negative for E. coli infection. The 18 samples were screened on MALDI-TOF for identification. Further, the samples were assessed for susceptibility to antibiotic medication within the study area. Result The study identified different strains of E. coli, and the CHB gene E. coli was found in eight samples. The sample showed pink oval-round spots in the culture medium and was resistant to nitrofurantoin, cephalosporin, and cephalexin antibiotics. Hence, antimicrobial susceptibility tests are necessary for managing and treating bacterial E. coli infections. Conclusion E. coli is a common bacterium found in the vaginal region of patients, suggesting a potential infection. E. coli can be associated with UTIs in women. The results from this study conclude that E. coli is rapidly becoming multidrug-resistant, as only higher antibiotics can inhibit its growth. To effectively manage infections caused by E. coli proper diagnosis, laboratory testing, and antibiotic treatment are required.

Lacticaseibacillus chiayiensis mediate intestinal microbiome and microbiota-derived metabolites regulating the growth and immunity of chicks

Emerging evidence confirms beneficial properties of probiotics in promoting growth and immunity of farmed chicken. However, the molecular mechanisms underlying the host-microbiome interactions mediated by probiotics are not fully understood. In this study, the internal mechanisms of Lacticaseibacillus chiayiensis-mediated host-microbiome interactions and to elucidate how it promotes host growth were investigated by additional supplementation with L. chiayiensis. We conducted experiments, including intestinal cytokines, digestive enzymes test, intestinal microbiome, metabolome and transcriptome analysis. The results showed that chickens fed L. chiayiensis exhibited higher body weight gain and digestive enzyme activity, and lower pro-inflammatory cytokines, compared to controls. Microbiota sequencing analysis showed that the gut microbiota structure was reshaped with L. chiayiensis supplementation. Specifically, Lactobacillus and Escherichia increased in abundance and Enterococcus, Lactococcus, Corynebacterium, Weissella and Gallicola decreased. In addition, the bacterial community diversity was significantly increased compared to controls. Metabolomic and transcriptomic analyses revealed that higher bile acids and N-acyl amides concentrations and lower carbohydrates concentrations in L. chiayiensis-fed chickens. Meanwhile, the expression of genes related to nutrient transport and absorption in the intestine was upregulated, which reflected the enhanced digestion and absorption of nutrients in chickens supplemented with L. chiayiensis. Moreover, supplementation of L. chiayiensis down-regulated genes involved in inflammation-related, mainly involved in NF-κB signaling pathway and MHC-II mediated antigen presentation process. Cumulatively, these findings highlight that host-microbiota crosstalk enhances the host growth phenotype in two ways: by enhancing bile acid metabolism and digestive enzyme activity, and reducing the occurrence of intestinal inflammation to promote nutrient absorption and maintain intestinal health. This provides a basis for the application of LAB as an alternative to antibiotics in animal husbandry.

Surface-enhanced Raman spectroscopy for studying the interaction of organometallic compound bis(1,3-dihexylimidazole-2-yl) silver(i) hexafluorophosphate (v) with the biofilm of Escherichia coli

Escherichia coli biofilms are a major cause of gastrointestinal tract diseases, such as esophageal, stomach and intestinal diseases. Nowadays, these are the most commonly occurring diseases caused by consuming contaminated food. In this study, we evaluated the efficacy of probiotics in controlling multidrug-resistant E. coli and reducing its ability to form biofilms. Our results substantiate the effective use of probiotics as antimicrobial alternatives and to eradicate biofilms formed by multidrug-resistant E. coli. In this research, surface enhanced Raman spectroscopy (SERS) was utilized to identify and evaluate Escherichia coli biofilms and their response to the varying concentrations of the organometallic compound bis(1,3-dihexylimidazole-2-yl) silver(i) hexafluorophosphate (v). Given the escalating challenge of antibiotic resistance in bacteria that form biofilms, understanding the impact of potential antibiotic agents is crucial for the healthcare sector. The combination of SERS with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) enabled the detection and characterization of the biofilm, providing insights into the biochemical changes induced by the antibiotic candidate. The identified SERS spectral features served as indicators for elucidating the mode of action of the potential drug on the biofilm. Through PCA and PLS-DA, metabolic variations allowing the differentiation and classification of unexposed biofilms and biofilms exposed to different concentrations of the synthesized antibiotic were successfully identified, with 95% specificity, 96% sensitivity, and a 0.75 area under the curve (AUC). This research underscores the efficiency of surface enhanced Raman spectroscopy in differentiating the impact of potential antibiotic agents on E. coli biofilms.

In vitro antibacterial and anti-biofilm potential of an endophytic Schizophyllum commune

The emergence of antibiotic resistance in pathogens is one of the major health concerns facing mankind as different bacterial strains have developed resistance to antibiotics over the period of time due to overuse and misuse of antibiotics. Besides this, ability to form biofilms is another major factor contributing to antibiotic resistance, which has necessitated the need for exploration for novel and effective compounds with ability to inhibit biofilm formation. Endophytic fungi are reported to exhibit antibacterial and anti-biofilm potential and could serve as a potent source of novel antibacterial compounds. Majority of the bioactivities have been reported from fungi belonging to phylum Ascomycota. Endophytic basidiomycetes, inspite of their profound ability to serve as a source of bioactive compounds have not been exploited extensively. In present study, an attempt was made to assess the antibacterial, anti-biofilm and biofilm dispersion potential of an endophytic basidiomycetous fungus Schizophyllum commune procured from the culture collection of our lab. Ethyl acetate extract of S. commune showed good antibacterial activity against Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica and Vibrio cholerae. Minimum inhibitory concentration and minimum bactericidal concentration of the extract were in the range of 1.25-10 mg/ml against the tested bacterial pathogens. The mode of action was determined to be bactericidal which was further confirmed by time kill studies. Good anti-biofilm activity of S. commune extract was recorded against K. pneumoniae and S. enterica, which was further validated by fluorescence microscopy. The present study highlights the importance of endophytic basidiomycetes as source of therapeutic compounds.

Genetic features of antimicrobial drug-susceptible extraintestinal pathogenic Escherichia coli pandemic sequence type 95

IMPORTANCE

Despite the increasing prevalence of antibiotic-resistant Escherichia coli strains that cause urinary tract and bloodstream infections, a major pandemic lineage of extraintestinal pathogenic E. coli (ExPEC) ST95 has a comparatively low frequency of drug resistance. We compared the genomes of 1,749 ST95 isolates to identify genetic features that may explain why most strains of ST95 resist becoming drug-resistant. Identification of such genomic features could contribute to the development of novel strategies to prevent the spread of antibiotic-resistant genes and devise new measures to control antibiotic-resistant infections.

Determination of antibiotic resistance patterns and genotypes of Escherichia coli isolated from wild birds

BACKGROUND

Curbing the potential negative impact of antibiotic resistance, one of our era's growing global public health crises, requires regular monitoring of the resistance situations, including the reservoir of resistance genes. Wild birds, a possible bioindicator of antibiotic resistance, have been suggested to play a role in the dissemination of antibiotic-resistant bacteria. Therefore, this study was conducted with the objective of determining the phenotypic and genotypic antibiotic resistance profiles of 100 Escherichia coli isolates of gull and pigeon origin by using the Kirby-Bauer disk diffusion method and PCR. Furthermore, the genetic relationships of the isolates were determined by RAPD-PCR.

RESULTS

Phenotypic antibiotic susceptibility testing revealed that 63% (63/100) and 29% (29/100) of E. coli isolates were resistant to at least one antibiotic and multidrug-resistant (MDR), respectively. With the exception of cephalothin, to which the E. coli isolates were 100% susceptible, tetracycline (52%), kanamycin (38%), streptomycin (37%), ampicillin (28%), chloramphenicol (21%), trimethoprim/sulfamethoxazole (19%), gentamicin (13%), enrofloxacin (12%) and ciprofloxacin (12%) resistances were detected at varying degrees. Among the investigated resistance genes, tet(B) (66%), tet(A) (63%), aphA1 (48%), sul3 (34%), sul2 (26%), strA/strB (24%) and sul1 (16%) were detected. Regarding the genetic diversity of the isolates, the RAPD-PCR-based dendrograms divided both pigeon and gull isolates into five different clusters based on a 70% similarity threshold. Dendrogram analysis revealed 47-100% similarities among pigeon-origin strains and 40-100% similarities among gull-origin E.coli strains.

CONCLUSIONS

This study revealed that gulls and pigeons carry MDR E. coli isolates, which may pose a risk to animal and human health by contaminating the environment with their feces. However, a large-scale epidemiological study investigating the genetic relationship of the strains from a "one health" point of view is warranted to determine the possible transmission patterns of antibiotic-resistant bacteria between wild birds, the environment, humans, and other hosts. Video Abstract.

Molecular detection of Shiga toxin and extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates from sheep and goats

BACKGROUND

The Shiga toxin (Stx)-producing Escherichia coli (STEC) have become important global public health concerns. This study investigated the prevalence, antimicrobial resistance profile, and extended-spectrum beta-lactamase-producing E. coli in sheep and goat faeces.

METHODS AND RESULTS

A total of 53 E. coli isolates were confirmed by PCR targeting the uidA [β-D glucuronidase] gene. The Shiga toxin genes stx1 and stx2, as well as bfpA, vir, eaeA, lt and aafII virulence genes, were detected in this study. Of the 53 isolates confirmed to be STEC, 100% were positive for stx2 and 47.2% for stx1. Three isolates possessed a combination of stx1 + stx2 + eaeA, while four isolates harboured stx1 + stx2 + vir virulence genes. The isolates displayed phenotypic antimicrobial resistance against erythromycin (66.04%), colistin sulphate (43.4%), chloramphenicol (9.4%) and ciprofloxacin (1.9%). A total of 28.8% of the strains were phenotypically considered ESBL producers and contained the beta-lactamase blaCTX-M-9 and blaCTX-M-25 gene groups. A larger proportion of the E. coli strains (86.8%) contained the antibiotic sulphonamide resistant (sulII) gene, while 62.3%, 62.3%, 52.8%, 43.4%, 41.5%, 20.8%, 18.9%, 11.3%, 11.3%, 9.4%, 9.4% and 5.7% possessed mcr-4, floR, mcr-1, tet(A), sulI, tet(O), tet(W), parC, mcr-2, ampC 5, qnrS and ermB genes, respectively. Thirteen isolates of the ESBL-producing E. coli were considered multi-drug resistant (MDR). One Shiga toxin (stx2) and two beta-lactamase genes (blaCTX-M-9 and blaCTX-M-25 groups) were present in 16 isolates. In conclusion, the E. coli isolates from the small stock in this study contained a large array of high antibiotic resistance and virulence profiles.

CONCLUSIONS

Our findings highlight the importance of sheep and goats as sources of virulence genes and MDR E. coli. From a public health and veterinary medicine perspective, the characterization of ESBL producers originating from small livestock (sheep and goats) is crucial due to their close contact with humans.

Electrochemical biosensing for E.coli detection based on triple helix DNA inhibition of CRISPR/Cas12a cleavage activity

BACKGROUND

Escherichia coli (E.coli) is both a commensal and a foodborne pathogenic bacterium in the human gastrointestinal tract, posing significant potential risks to human health and food safety. However, one of the major challenges in E.coli detection lies in the preparation and storage of antibodies. In traditional detection methods, antibodies are indispensable, but their instability often leads to experimental complexity and increased false positives. This underscores the need for new technologies and novel sensors. Therefore, the development of a simple and sensitive method for analyzing E.coli would make significant contributions to human health and food safety.

RESULTS

We constructed an electrochemical biosensor based on triple-helical DNA and entropy-driven amplification reaction (EDC) to inhibit the cleavage activity of Cas12a, enabling high-specificity detection of E.coli. Replacing antibodies with nucleic acid aptamers (Apt) as recognition elements, we utilized the triple-helical DNA generated by the binding of DNA2 and DNA5/DNA6 double-helical DNA through the entropy-driven amplification reaction to inhibit the collateral cleavage activity of clustered regularly interspaced short palindromic repeats gene editing system (CRISPR) and its associated proteins (Cas). By converting E.coli into electrical signals and recording signal changes in the form of square wave voltammetry (SWV), rapid detection of E.coli was achieved. Optimization of experimental conditions and data detection under the optimal conditions provided high sensitivity, low detection limits, and high specificity.

SIGNIFICANCE

With a minimal detection limit of 5.02 CFU/mL and a linear range of 1 × 102 - 1 × 107 CFU/mL, the suggested approach was successfully verified to analyze E.coli at various concentrations. Additionally, after examining E.coli samples from pure water and pure milk, the recoveries ranged between 95.76 and 101.20%, demonstrating the method's applicability. Additionally, it provides a feasible research direction for the detection of pathogenic bacteria causing other diseases using the CRISPR/Cas gene editing system.

Two-Pronged Dormant Photosensitizer-Antibiotic Bacterial Inactivation: Mechanism, Dosage, and Cellular Evolution Visualized at the Single-Cell Level

Innovative therapeutic approaches are required to battle the rise of antibiotic-resistant bacterial strains. Tapping on reactive oxygen species (ROS) generation in bacteria induced by bactericidal antibiotics, here we report a two-pronged strategy for bacterial inactivation relying on the synergistic combination of a bactericidal antibiotic and newly designed dormant photosensitizers (DoPSs) that activate in the presence of ROS. Intramolecular quenching renders DoPS inert in the presence of light. ROS trapping by DoPS aborts the quenching mechanism unmasking, in equal proportions, singlet oxygen (1O2) sensitization and fluorescence emission. Juxtaposed antioxidant-prooxidant activity built within our DoPS enables (i) initial activation of a few molecules by ROS and (ii) subsequent rapid activation of all DoPS in a bacterium via a domino effect mediated by photogenerated 1O2. Bulk colony forming unit studies employing the minimum inhibitory concentration of the antibiotic illustrate rapid and selective inactivation of Escherichia coli and Pseudomonas aeruginosa only in the presence of light, antibiotic, and DoPS. Single-cell, real-time imaging studies on E. coli reveal an autocatalytic progression of DoPS activation from focal points, providing a unique amplification system for sensing. Single-cell analysis further illustrates the impact of DoPS cellular loading on the rate of DoPS activation and cell death times and on the 1O2 dosing necessary for cell death to occur. Our two-pronged therapy discriminates based on cell metabolites and has the potential to result in lower toxicity, pave the way to reduced drug resistance, and provide insightful mechanistic information about bacterial membrane response to 1O2.

Droplet-based methodology for investigating bacterial population dynamics in response to phage exposure

An alarming rise in antimicrobial resistance worldwide has spurred efforts into the search for alternatives to antibiotic treatments. The use of bacteriophages, bacterial viruses harmless to humans, represents a promising approach with potential to treat bacterial infections (phage therapy). Recent advances in microscopy-based single-cell techniques have allowed researchers to develop new quantitative methodologies for assessing the interactions between bacteria and phages, especially the ability of phages to eradicate bacterial pathogen populations and to modulate growth of both commensal and pathogen populations. Here we combine droplet microfluidics with fluorescence time-lapse microscopy to characterize the growth and lysis dynamics of the bacterium Escherichia coli confined in droplets when challenged with phage. We investigated phages that promote lysis of infected E. coli cells, specifically, a phage species with DNA genome, T7 (Escherichia virus T7) and two phage species with RNA genomes, MS2 (Emesvirus zinderi) and Qβ (Qubevirus durum). Our microfluidic trapping device generated and immobilized picoliter-sized droplets, enabling stable imaging of bacterial growth and lysis in a temperature-controlled setup. Temporal information on bacterial population size was recorded for up to 25 h, allowing us to determine growth rates of bacterial populations and helping us uncover the extent and speed of phage infection. In the long-term, the development of novel microfluidic single-cell and population-level approaches will expedite research towards fundamental understanding of the genetic and molecular basis of rapid phage-induced lysis and eco-evolutionary aspects of bacteria-phage dynamics, and ultimately help identify key factors influencing the success of phage therapy.

Domestic cats are potential reservoirs of multidrug-resistant human enteropathogenic E. coli strains in Bangladesh

Companion animals serve as our best friends, confidants, and family members. Thus, disease and antibiotic resistance gene transmission in pets and humans must be sought out. The study aimed to identify the common pathogenic Escherichia coli (E.coli) in pet cats and the antibiotic resistance patterns and resistant gene distribution. Samples (n = 210) were collected from different veterinary clinics in Bangladesh's cities of Mymensingh and Dhaka. Pathogenic E. coli was identified using conventional and molecular approaches. The disc diffusion method assessed the resistance profile against 12 antibiotics, and PCR was used to identify the beta-lactam resistance genes. The prevalence of the stx-1 gene was found to be 2.86%, whereas the rfbO157 prevalence was found to be 1.90% in cats. The stx-1 gene (n = 6) was 100% resistant to erythromycin and imipenem, whereas 100% sensitive to chloramphenicol. In turn, the rfbO157 gene (n = 4) exhibited 100% resistance to erythromycin, imipenem, cefixime, and azithromycin. In addtion, we identified genes that exhibit resistance to beta-lactam antibiotics (100% blaTEM, 40% blaCTX-M, 40% blaSHV2). This study found shiga-toxin producing and extended-spectrum beta-lactamase (ESBL) producing E. coli for the first time in pet cats of Bangladesh. Furthermore, the antimicrobial resistance (AMR) profile of the isolated strains refers to the occurrence of multidrug, which concerns cats and their owners. The existence of these genes in non-diarrheic pet animal isolates indicates that domestic pets may serve as a reservoir for human infection. Thus, one health strategy comprising animal and human health sectors, governments, together with stakeholders is needed to confront multidrug-resistant E. coli infections in Bangladesh.

Mechanistic insights into the cinnamaldehyde modification of lignin for sustainable anti-fungal reagent

The limited anti-fungal activity of enzymatic hydrolysis lignin (EHL) has been a challenge in its direct application as a bamboo preservative. To address this issue, the cinnamaldehyde modification of EHL was carried out to introduce anti-fungal structures into the lignin matrix, effectively enhancing its anti-fungal activity. The results demonstrated that the minimal inhibitory concentrations of the modified lignin (EHL-DC) against Aspergillus niger significantly improved from 16 mg/mL to 1 mg/mL, with comparable enhancements in anti-fungal activity against other fungi. As a result of the modification, the EHL-DC is more prone to interact with fungal cell membranes, contributing to a roughened, shrunken hyphal surface and a decrease in mycelial biomass. Multiple characterization methods were employed to better grapple with the EHL-DC chemical changes. The nitrogen content increased from 2.3 % to 8.3 %, and alterations in elemental compositions further support the proposed reaction mechanism and its role in enhancing EHL's anti-fungal activity. This study offers novel insights into the high-value utilization of enzymatic hydrolysis lignin based on green chemistry principles.

"One Health" perspective on prevalence of co-existing extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae: a comprehensive systematic review and meta-analysis

BACKGROUND

The Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) bacterial isolates that produce extended-spectrum β-lactamases (ESBLs) contribute to global life-threatening infections. This study conducted a systematic review and meta-analysis on the global prevalence of ESBLs in co-existing E. coli and K. pneumoniae isolated from humans, animals and the environment.

METHODS

The systematic review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) [ID no: CRD42023394360]. This study was carried out following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. One hundred and twenty-six eligible studies published on co-existing antibiotic resistance in E. coli and K. pneumoniae between 1990 and 2022 were included.

RESULTS

The pooled prevalence of ESBL-producing E. coli and K. pneumoniae was 33.0% and 32.7% for humans, 33.5% and 19.4% for animals, 56.9% and 24.2% for environment, 26.8% and 6.7% for animals/environment, respectively. Furthermore, the three types of resistance genes that encode ESBLs, namely blaSHVblaCTX-M,blaOXA, and blaTEM, were all detected in humans, animals and the environment.

CONCLUSIONS

The concept of "One-Health" surveillance is critical to tracking the source of antimicrobial resistance and preventing its spread. The emerging state and national surveillance systems should include bacteria containing ESBLs. A well-planned, -implemented, and -researched alternative treatment for antimicrobial drug resistance needs to be formulated.

Gentamicin resistance to Escherichia coli related to fatty acid metabolism based on transcriptome analysis

Antibiotic overuse and misuse have promoted the emergence and spread of antibiotic-resistant bacteria. Increasing bacterial resistance to antibiotics is a major healthcare problem, necessitating elucidation of antibiotic resistance mechanisms. In this study, we explored the mechanism of gentamicin resistance by comparing the transcriptomes of antibiotic-sensitive and -resistant Escherichia coli. A total of 410 differentially expressed genes were identified, of which 233 (56.83%) were up-regulated and 177 (43.17%) were down-regulated in the resistant strain compared with the sensitive strain. Gene Ontology (GO) analysis classifies differential gene expression into three main categories: biological processes, cellular components, and molecular functions. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that the up-regulated genes were enriched in eight metabolic pathways, including fatty acid metabolism, which suggests that fatty acid metabolism may be involved in the development of gentamicin resistance in E. coli. This was demonstrated by measuring the acetyl-CoA carboxylase activity, plays a fundamental role in fatty acid metabolism, was increased in gentamicin-resistant E. coli. Treatment of fatty acid synthesis inhibitor, triclosan, promoted gentamicin-mediated killing efficacy to antibiotic-resistant bacteria. We also found that exogenous addition of oleic acid, which involved in fatty acid metabolism, reduced E. coli sensitivity to gentamicin. Overall, our results provide insight into the molecular mechanism of gentamicin resistance development in E. coli.

Agonistic antibacterial potential of Loigolactobacillus coryniformis BCH-4 metabolites against selected human pathogenic bacteria: An in vitro and in silico approach

Lactic acid bacteria are known to produce numerous antibacterial metabolites that are active against various pathogenic microbes. In this study, bioactive metabolites from the cell free supernatant of Loigolactobacillus coryniformis BCH-4 were obtained by liquid-liquid extraction, using ethyl acetate, followed by fractionation, using silica gel column chromatography. The collected F23 fraction effectively inhibited the growth of pathogenic bacteria (Escherichia coli, Bacillus cereus, and Staphylococcus aureus) by observing the minimum inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC). The evaluated values of MIC were 15.6 ± 0.34, 3.9 ± 0.59, and 31.2 ± 0.67 μg/mL and MBC were 15.6 ± 0.98, 7.8 ± 0.45, and 62.5 ± 0.23 μg/mL respectively, against the above-mentioned pathogenic bacteria. The concentration of F23 fraction was varying from 1000 to 1.9 μg/mL. Furthermore, the fraction also exhibited sustainable biofilm inhibition. Using the Electrospray Ionization Mass Spectrometry (ESI-MS/MS), the metabolites present in the bioactive fraction (F23), were identified as phthalic acid, myristic acid, mangiferin, 16-hydroxylpalmatic acid, apigenin, and oleandomycin. By using in silico approach, docking analysis showed good interaction of identified metabolites and receptor proteins of pathogenic bacteria. The present study suggested Loigolactobacillus coryniformis BCH-4, as a promising source of natural bioactive metabolites which may receive great benefit as potential sources of drugs in the pharmacological sector.

Antimicrobial Resistance Patterns and Risk Factors Associated with ESBL-Producing and MDR Escherichia coli in Hospital and Environmental Settings in Lusaka, Zambia: Implications for One Health, Antimicrobial Stewardship and Surveillance Systems

Antimicrobial resistance (AMR) is a public health problem threatening human, animal, and environmental safety. This study assessed the AMR profiles and risk factors associated with Escherichia coli in hospital and environmental settings in Lusaka, Zambia. This cross-sectional study was conducted from April 2022 to August 2022 using 980 samples collected from clinical and environmental settings. Antimicrobial susceptibility testing was conducted using BD PhoenixTM 100. The data were analysed using SPSS version 26.0. Of the 980 samples, 51% were from environmental sources. Overall, 64.5% of the samples tested positive for E. coli, of which 52.5% were from clinical sources. Additionally, 31.8% were ESBL, of which 70.1% were clinical isolates. Of the 632 isolates, 48.3% were MDR. Most clinical isolates were resistant to ampicillin (83.4%), sulfamethoxazole/trimethoprim (73.8%), and ciprofloxacin (65.7%) while all environmental isolates were resistant to sulfamethoxazole/trimethoprim (100%) and some were resistant to levofloxacin (30.6%). The drivers of MDR in the tested isolates included pus (AOR = 4.6, CI: 1.9-11.3), male sex (AOR = 2.1, CI: 1.2-3.9), and water (AOR = 2.6, CI: 1.2-5.8). This study found that E. coli isolates were resistant to common antibiotics used in humans. The presence of MDR isolates is a public health concern and calls for vigorous infection prevention measures and surveillance to reduce AMR and its burdens.

Probiotic supplementation during antibiotic treatment is unjustified in maintaining the gut microbiome diversity: a systematic review and meta-analysis

BACKGROUND

Probiotics are often used to prevent antibiotic-induced low-diversity dysbiosis, however their effect is not yet sufficiently summarized in this regard. We aimed to investigate the effects of concurrent probiotic supplementation on gut microbiome composition during antibiotic therapy.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials reporting the differences in gut microbiome diversity between patients on antibiotic therapy with and without concomitant probiotic supplementation. The systematic search was performed in three databases (MEDLINE (via PubMed), Embase, and Cochrane Central Register of Controlled Trials (CENTRAL)) without filters on 15 October 2021. A random-effects model was used to estimate pooled mean differences (MD) with 95% confidence intervals (CI). This review was registered on PROSPERO (CRD42021282983).

RESULTS

Of 11,769 identified articles, 15 were eligible in the systematic review and 5 in the meta-analyses. Quantitative data synthesis for Shannon (MD = 0.23, 95% CI: [(-)0.06-0.51]), Chao1 (MD = 11.59 [(-)18.42-41.60]) and observed OTUs (operational taxonomic unit) (MD = 17.15 [(-)9.43-43.73]) diversity indices revealed no significant difference between probiotic supplemented and control groups. Lacking data prevented meta-analyzing other diversity indices; however, most of the included studies reported no difference in the other reported α- and ß-diversity indices between the groups. Changes in the taxonomic composition varied across the eligible studies but tended to be similar in both groups. However, they showed a potential tendency to restore baseline levels in both groups after 3-8 weeks. This is the first meta-analysis and the most comprehensive review of the topic to date using high quality methods. The limited number of studies and low sample sizes are the main limitations of our study. Moreover, there was high variability across the studies regarding the indication of antibiotic therapy and the type, dose, and duration of antimicrobials and probiotics.

CONCLUSIONS

Our results showed that probiotic supplementation during antibiotic therapy was not found to be influential on gut microbiome diversity indices. Defining appropriate microbiome diversity indices, their standard ranges, and their clinical relevance would be crucial.

Application of BI-EHEC and BI-EPEC bacteriophages to control enterohemorrhagic and enteropathogenic escherichia coli on various food surfaces

OBJECTIVES

The purposes of this study were to determine the Efficiency of Plating (EOP) value of Bacteriophage BI-EHEC and BI-EPEC and to evaluate the application of these bacteriophages in reducing population of EHEC and EPEC on various food samples.

RESULTS

In this study, we used bacteriophage BI-EHEC and BI-EPEC, which were isolated from previous study. Both phages were tested with other multiple pathotypes of intestinal pathogenic E. coli to determine the efficiency of plating. BI-EHEC had high efficiency toward ETEC with an EOP value of 2.95 but low efficiency toward EHEC with an EOP value of 0.10, while BI-EPEC had high efficiency toward EHEC and ETEC with EOP values of 1.10 and 1.21, respectively. As biocontrol agents, both bacteriophages able to reduce CFU of EHEC and EPEC in several food samples using 1 and 6-days incubation times at 4 [Formula: see text]. BI-EHEC reduced the number of EHEC with an overall percentage of bacterial reduction value above 0.13 log₁₀, while BI-EPEC reduced number of EPEC with reduction value above 0.33 log₁₀.

Profiling of Antimicrobial Resistance Genes and Integron from Escherichia coli Isolates Using Whole Genome Sequencing

This study is designed to investigate Escherichia coli for the antibiotic resistance genes (ARGs) and integrons from healthy as well as diarrhoeic/diseased animals/birds' faecal samples. A total of eight samples were selected for the study; from each animal, two samples were taken, one from healthy animals/birds and one from diarrhoeic/diseased animals/birds. Antibiotic sensitivity testing (AST) and whole genome sequencing (WGS) was performed for selected isolates. The E. coli isolates showed resistance to moxifloxacin, followed by erythromycin, ciprofloxacin, pefloxacin, tetracycline, levofloxacin, ampicillin, amoxicillin, and sulfadiazine (4/8, 50.00% each). The E. coli isolates were 100% sensitive to amikacin, followed by chloramphenicol, cefixime, cefoperazone, and cephalothin. A total of 47 ARGs from 12 different antibiotic classes were detected among the eight isolates by WGS. The different classes of antibiotics included aminoglycoside, sulphonamide, tetracycline, trimethoprim, quinolone, fosfomycin, phenicol, macrolide, colistin, fosmidomycin, and multidrug efflux. The class 1 integrons were detected in 6/8 (75.00%) isolates with 14 different gene cassettes.

Switchover of electrotrophic and heterotrophic respirations enables the biomonitoring of low concentration of BOD in oxygen-rich environment

Biochemical oxygen demand (BOD) is a key indicator of water quality. However, there is still no technique to directly measure BOD at low concentrations in oxygen-rich environments. Here, we propose a new scheme using facultative electrotrophs as the sensing element, and confirmed aerobic Acinetobacter venetianus RAG-1 immobilized on electrode was able to measure BOD via the switchover between electrotrophic and heterotrophic respirations. The hybrid binder of Nafion and polytetrafluoroethylene (PTFE) maximized the baseline current (127 ± 2 A/m²) and sensitivity (2.5 ± 0.1 (mA/m²)/(mg/L)). The current decrease and the BOD₅ concentration fitted well with a linear model in the case of known contaminants, verified with both lab samples of acetate and glucose (R²>0.96) and in standard curves of real environmental samples collected from the lake and the effluent of wastewater treatment plant (R²>0.98). Importantly, the biosensor tested actual contaminated water samples with an error of 0.4∼10% compared to BOD₅ in the case of unknown contaminants. Transcriptomics revealed that reverse oxidative TCA may involve in the electrotrophic respiration of RAG-1 since citrate synthase (gltA) was highly expressed, which was partly downregulated when heterotrophic metabolism was triggered by BOD. This can be returned to electrotroph when BOD was depleted. Our results showed a new way to rapidly measure BOD in oxygen-rich environment, demonstrating the possibility to employ bacteria with two competitive respiration pathways for pollution detection.

A Diagnostic Quandary of Escherichia Coli Pneumonia: A Case Report and Literature Review

Escherichia coli community-acquired pneumonia (CAP) is an under-recognized condition associated with higher mortality compared to the other well-studied causes of pneumonia. E. coli pneumonia is frequently associated with bacteremia. Despite the absence of abdominal or urinary symptoms, the infection may originate from an occult gastrointestinal (GI) source since it is a common commensal bacteria of the GI tract. Conditions related to extraintestinal pathogenic E. coli (ExPEC) are gaining attention, and there has been a trend toward the rise of pneumonia secondary to gram-negative bacteria. This presents a diagnostic stewardship dilemma in a patient with sepsis, E. coli bacteremia, and apparent pneumonia - to assume and treat for E. coli CAP or to look for a GI/genitourinary source which may, in turn, lead to incidental findings and further studies. We report a case of E. coli CAP in a 62-year-old patient and our approach regarding the treatment and imaging course.

Synthesis of biologically derived poly(pyrogallol) nanofibers for antibacterial applications

Herein, we present the facile synthesis of poly(pyrogallol) biopolymers and their application as antibacterial agents. Pyrogallol is a class of phenolic compounds that can be found in various plants. Polymerization was performed by the auto-oxidation of pyrogallol under a hydrated condition. The microscopic image of poly(pyrogallol) shows a highly homogenous nanofibrous structure with a diameter of 100.3 ± 16.3 nm. Spectroscopic analysis by FT-IR spectroscopy, Raman spectroscopy, and XPS corroborated the formation of ether (C-O-C) bonds between the hydroxyl group and adjacent carbons of pyrogallol during polymerization. The FT-IR and XPS spectra also revealed redox-active gallol functional groups on poly(pyrogallol) nanofibers, which can be used to release free electrons and protons during oxidation followed by the generation of reactive oxygen species (ROS). The generated ROS from poly(pyrogallol) was used to inhibit the growth of bacteria, Escherichia coli, at a inhibition rates of 56.3 ± 9.7% and 95.5 ± 2.0% within 0.5 and 2 h, respectively. This finding suggests that poly(pyrogallol) can be used as a naturally occurring antibacterial agent for various biomedical and environmental applications.

Development of a phage-based electrochemical biosensor for detection of Escherichia coli O157: H7 GXEC-N07

Escherichia coli (E. coli) O157:H7 is one of the most important foodborne pathogens that causing severe foodborne diseases. With the development of foodborne diseases, there is an urgent need to seek new methods for early detection and monitoring of E. coli O157:H7. In this study, an electrochemical biosensor using phage EP01 as the recognition agent for detection of E. coli O157:H7 GXEC-N07 was established due to the specificity and high efficiency of phage EP01 in recognizing GXEC-N07. The biosensor was developed by depositing phages conjugated carboxyl graphene oxide (CFGO) and conductive carbon black (CB) onto the surface of glass carbon electrodes (GCEs). When detecting GXEC-N07 in the concentration range of 10² ∼ 10⁷ CFU/mL, the biosensor showed good linearity with a low detection limit of 11.8 CFU/mL, and the whole progress was in less than 30 min. The biosensor was successfully applied to the quantitative detection of GXEC-N07 in fresh milk and raw pork. The recovery values ranged from 60.8 % to 114.2 %. The biosensor provides a rapid, specific, low cost, and label free tool for E. coli O157:H7 GXEC-N07 detection. It is expected to become a powerful method for the detection of bacteria that threatening food safety and public health security.

Evolution of Antibiotic Resistance in Escherichia coli and Klebsiella pneumoniae Clinical Isolates in a Multi-Profile Hospital over 5 Years (2017-2021)

In recent years, we have witnessed a growing drug resistance among bacteria, which is associated with the use and availability of an increasing number of broad-spectrum antimicrobial agents, as well as with their irrational and excessive use. The present study aims to analyze changes in the drug resistance of Gram-negative Enterobacterales: Escherichia coli and Klebsiella pneumoniae, isolated from infections in a multi-profile hospital over five years (from 2017 to 2021). Among the practical outcomes of the evaluation of these data will be the possibility of determining changes in susceptibility to the antibiotics used in the hospital. In turn, this will help propose new therapeutic options, especially for empirical therapy that is necessary in severe infections. The analysis of the use of individual groups of antibiotics allowed for identification of the causes of the increasing resistance of Gram-negative bacilli. The highest number of infections whose etiological agent was K. pneumoniae ESBL(+) and E. coli ESBL(+) was observed in 2018. In the analyzed five-year period, the number of multi-resistant (MDR) K. pneumoniae strains increased successively, which seems to be related to the growing use, especially in the pandemic period, of broad-spectrum antibiotics, mainly penicillins with inhibitors, third-generation cephalosporins, and carbapenems.

The impact of environmental factors on the transport and survival of pathogens in agricultural soils from karst areas of Yunnan province, China: Laboratory column simulated leaching experiments

Introduction

Groundwater is considered the best candidate for drinking water supply in the karst area. The groundwater water resources, however, are vulnerable to pathogenic microorganism contamination because of the typically thin soil layers overlying aquifers and the high permeability of the aquifer host rock, resulting in short residence times and low natural attenuation capacities. Until now, little attention has been paid to the critical environmental factors affecting the pathogenic microorganism contamination in soil-groundwater systems in the karst area.

Methods

In the study, orthogonality column experiments with controlling ambient temperatures, pH values of inlet water, and soil porosities were carried out to investigate the transport and lifespan of pathogenic microorganisms in the leachate of agricultural soils in the karst area of Yunnan province, China. The pathogenic indicators, i.e., total bacteria count (TBC) and total coliforms count (TCC), and hydrochemical parameters, i.e., pH and permanganate index (CODMn) in the leaching water, were systematically monitored.

Results and Discussion

The results showed that bacteria including coliforms can survive for prolonged periods of time in karst soils. The soils overlying the karst rocks were unable to impede the bacteria from seeping into the groundwater. The soils, in turn, likely served as both reservoirs and incubators for pathogenic bacteria. The ambient temperature was the most predominant influential factor affecting both TBC and TCC. The bacteria concentrations were proportional to the temperature in the leachate. Therefore, more attention should be paid to temperature variations in protecting the water supply, particularly in the high-temperature period, such as during the summer months.

Chemical Composition and Biological Activities of Essential Oils of Four Asarum Species Growing in Vietnam

The essential oils (EOs) of the aerial parts of four Asarum species (A. geophilum, A. yentunensis, A. splendens and A. cordifolium) were isolated by steam distillation and analyzed by the GC/MS method. The A. cordifolium EO contains 33 constituents with the main component being elemicine (77.20%). The A. geophilum EO was contains 49 constituents with the main components being determined as 9-epi-(E)-caryophyllene (18.43%), eudesm-7(11)-en-4-ol (13.41%), β-caryophyllene (8.05%) and phytol (7.23%). The A. yentunensis EO contains 26 constituents with the main components being safrole (64.74%) and sesquicineole (15.34%). The EO of A. splendens contains 41 constituents with the main components being 9-epi-(E)-caryophyllene (15.76%), eudesm-7(11)-en-4-ol (14.21%), β-caryophyllene (9.52%) and trans-bicyclogermacrene (7.50%). For antimicrobial activity, the A. yentunensis EO exhibited the highest inhibition activity against Staphylococcus aureus and the A. cordifolium EO against Bacillus subtillis (MIC values of 100 μg/mL). For antioxidant activity, the A. geophilum EO showed the highest potential with an SC (%) value of 63.34 ± 1.0%, corresponding to an SC50 value of 28.57 µg/mL. For anti-inflammatory activity, the A. splendens EO exhibited the highest potential with an IC50 value of 21.68 µg/mL, corresponding to an inhibition rate of NO production of 69.58 ± 1.3% and the percentage of cell life was 81.85 ± 0.9%.

Diversity of Bacterial Clones and Plasmids of NDM-1 Producing Escherichia coli Clinical Isolates in Central Greece

The objective of the present study was to genetically characterize ten NDM-1 producing Escherichia coli isolates, recovered from patients in a hospital in Central Greece during the period 2017 to 2021.The isolates were studied by whole genome sequencing to obtain multi-locus sequencing typing (MLST), identification of bla_NDM1-environment, resistome and plasmid content. MLST analysis showed the presence of eight sequence types: ST46* (two isolates), ST46, ST744, ST998, ST410, ST224, ST4380, ST683 and ST12 (one isolate each). Apart of the presence of bla_NDM-1, the isolates carried a combination of various to β-lactams encoding resistance genes: bla_TEM-1B, bla_CTX-15, bla_OXA-1, bla_VIM-1, bla_SHV-5, bla_OXA-16, bla_OXA-10 and bla_VEB-1. Additionally, plurality of resistance genes to aminoglycosides, macrolides, rifamycin, phenicols, sulfonamides and tetracycline was detected. The presence of multiple replicons was observed, with predominance of IncFII and IncFIB. Analysis of bla_NDM-1 genetic environment of the isolates showed that seven had 100% identity with the pS-3002cz plasmid (Accession Number KJ 958927), two with the pB-3002cz plasmid (Accession Number KJ958926) and one with the pEc19397-131 plasmid (Accession Number MG878866). Τhis latter plasmid was derived by the fusion of two, previously identified, plasmids, pAMPD2 and pLK75 (Accession Numbers CP078058 and KJ440076, respectively). The diversity of clones and plasmids of NDM-1 producing E. coli isolated from patients in Greece indicates a continuous horizontal gene transfer.

Glyco-conjugated metal-organic framework biosensor for fluorescent detection of bacteria

Metal-organic frameworks (MOFs) are hybrid materials constructed by the linkage between an inorganic secondary building unit and an organic linker. A number of MOFs are luminescent in nature and can be structurally tuned for desirable geometry, surface functionality, and porosity. Luminescent MOFs have been endorsed for various biosensing applications. Lectins and carbohydrates have been used for the development of simple and convenient biosensing and bioimaging tools. Lectins are mostly present on the surface of microorganisms where they aid in pathogenesis. Due to this, they can be potential targets for a microbial biosensor. The present study, for the first time, explores the usage of a carbohydrate-conjugated FeMOF (Glyco-MOF) bioprobe for the selective determination of Pseudomonas aeruginosa and Escherichia coli. NH₂-MIL-53(Fe) MOF was synthesized via a room temperature protocol and separately conjugated with galactose and mannose sugars via glutaraldehyde chemistry. The synthesized bioprobe is validated for structural integrity, luminescent nature, stability, and analyte assay. Electron microscopy studies validated the unhindered MOF's morphology and structural integrity, after bioconjugation. The synthesized bioprobes were able to detect P. aeruginosa and E. coli up to respective detection limits of 202 and 8 CFU/mL, respectively. The bioprobes are selective even in co-presence of possible interferants as well as being environmentally stable.

Antioxidant and Antimicrobial Evaluations of Moringa oleifera Lam Leaves Extract and Isolated Compounds

Moringa oleifera, native to India, grows in tropical and subtropical regions around the world and has valuable pharmacological properties such as anti-asthmatic, anti-diabetic, anti-inflammatory, anti-infertility, anti-cancer, anti-microbial, antioxidant, and many more. The purpose of this study was to assess the free radical scavenging ability of two extracts and two pure compounds of M. oleifera Lam (hexane, ethanol, compound E3, and compound Ra) against reactive oxygen species, as well as their reducing power and antimicrobial activities. Bioautography antioxidant assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H₂O₂) free radical scavenging, and iron (iii) (Fe³⁺ to Fe²⁺) chloride reducing power assays were used to assess the extracts' qualitative and quantitative free radical scavenging activities. Furthermore, the extract and the compounds were tested against both Gram-positive and Gram-negative bacterial strains suspended in Mueller-Hinton Broth. The extracts and pure compounds showed noteworthy antioxidant potential, with positive compound bands in the Rf range of 0.05-0.89. DPPH), H₂O₂, and Fe³⁺ to Fe²⁺ reduction assays revealed that ethanol extract has a high antioxidant potential, followed by compound E3, compound Ra, and finally hexane extract. Using regression analysis, the half maximal inhibitory concentration (IC₅₀) values for test and control samples were calculated. Compound Ra and ethanol exhibited high antioxidant activity at concentrations as low as ≈0.28 mg/mL in comparison with n-hexane extract, compound E3, ascorbic acid, and butylated hydroxytoluene standards. The radical scavenging activity of almost all M. oleifera plant extracts against DPPH was observed at 0.28 mg/mL; however, the highest activity was observed at the same concentration for ascorbic acid and butylated hydroxytoluene (BHT) with a low IC₅₀ value of 0.08 mg/mL and compound Ra and ethanol with a low IC₅₀ of 0.4 mg/mL, respectively. The extracts and pure compounds of M. oleifera have little to no antibacterial potential. M. oleifera extracts contain antioxidant agents efficient to alleviate degenerative conditions such as cancer and cardiovascular disease but have little activity against infectious diseases.

Fast identification and susceptibility determination of E. coli isolated directly from patients' urine using infrared-spectroscopy and machine learning

For effective treatment, it is crucial to identify the infecting bacterium at the species level and to determine its antimicrobial susceptibility. This is especially true now, when numerous bacteria have developed multidrug resistance to most commonly used antibiotics. Currently used methods need ∼ 48 h to identify a bacterium and determine its susceptibility to specific antibiotics. This study reports the potential of using infrared spectroscopy with machine learning algorithms to identify E. coli isolated directly from patients' urine while simultaneously determining its susceptibility to antibiotics within ∼ 40 min after receiving the patient's urine sample. For this goal, 1,765 E. coli isolates purified directly from urine samples were collected from patients with urinary tract infections (UTIs). After collection, the samples were tested by infrared microscopy and analyzed by machine learning. We achieved success rates of ∼ 96% in isolate level identification and ∼ 84% in susceptibility determination.

Determination of antimicrobial resistance patterns of Escherichia coli isolates from farm workers in broiler poultry production and assessment of antibiotic resistance awareness levels among poultry farmers in Lusaka, Zambia

The challenges posed by antibiotic-resistant pathogens have continued to increase worldwide, particularly in resource-limited countries. Human-livestock interactions are implicated in the complex AMR causal web. A cross-sectional study was conducted in four districts of Lusaka Province, Zambia to determine the antibiotic resistance patterns, ESBL production of E. coli isolated from stool samples of broiler poultry farm workers, and to assess poultry farmers' antibiotic resistance awareness. Sixty-six human stool samples were collected and processed for E. coli isolation, antibiotic resistance testing, and screened for ESBL production. In addition, 80 farmers were assessed for their level of awareness on antibiotic resistance. A total of 58 single E. coli isolates were obtained which showed high (87.9%) resistance to tetracycline, trimethoprim/sulfamethoxazole (48.3%), and ampicillin (46.8%); followed by nalidixic acid (19.0%), ciprofloxacin (12.1%), cefotaxime (8.6%) and chloramphenicol (5.2%). The prevalence of AMR E. coli was 67.2%, and 29.3% were MDR. Two (3.4%) isolates were identified to be ESBL producers, harboring the CTX-M gene. The study results also showed that broiler farmers were aware and knowledgeable of antibiotic resistance, although knowledge about its impact on human health was low. This study demonstrated the presence of resistant and ESBL producing E. coli among poultry farm workers.

Biogenic nanosilver bearing antimicrobial and antibiofilm activities and its potential for application in agriculture and industry

Introduction

Due to the increasing resistance of bacteria and fungi to antimicrobials, it is necessary to search for effective alternatives to prevent and treat pathogens causing diseases in humans, animals, and plants. In this context, the mycosynthesized silver nanoparticles (AgNPs) are considered as a potential tool to combat such pathogenic microorganisms.

Methods

AgNPs were synthesized from Fusarium culmorum strain JTW1 and characterized by Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Nanoparticle Tracking Analysis (NTA), Dynamic Light Scattering (DLS) and Zeta potential measurement. The minimum inhibitory (MIC) and biocidal concentrations (MBC) were determined against 13 bacterial strains. Moreover, the combined effect of AgNPs with antibiotics (streptomycin, kanamycin, ampicillin, tetracycline) was also studied by determining the Fractional Inhibitory Concentration (FIC) index. The anti-biofilm activity was examined by crystal violet and fluorescein diacetate (FDA) assays. Furthermore, antifungal activity of AgNPs was evaluated against a panel of phytopathogenic fungi viz., Botrytis, Colletotrichum, Fusarium, Phoma, Sclerotinia, and an oomycete pathogen Phytophthora by agar well-diffusion and micro-broth dilution method to evaluate the minimal AgNPs concentrations that inhibit fungal spore germination.

Results

Fungi-mediated synthesis resulted in the formation of small (15.56 ± 9.22 nm), spherical and stable (zeta potential of - 38.43 mV) AgNPs with good crystallinity. The results of FTIR spectroscopy indicated the presence of various functional groups, namely hydroxyl, amino, and carboxyl ones, from the biomolecules on the surface of AgNPs. The AgNPs showed antimicrobial and antibiofilm formation activities against Gram-positive and Gram-negative bacteria. The values of MIC and MBC ranged between 16-64 and 32-512 μg mL^-1, respectively. The enhanced effect of AgNPs in combination with antibiotics was confirmed against human pathogens. The highest synergistic effect (FIC = 0.0625) was demonstrated by the combination of AgNPs with streptomycin against two strains of Escherichia coli (ATCC 25922 and ATCC 8739), followed by Klebsiella pneumoniae and Pseudomonas aeruginosa (FIC = 0.125). Enhanced effects of AgNPs with ampicillin were also shown against Staphylococcus aureus ATCC 25923 (FIC = 0.125) and P. aeruginosa (FIC = 0.25), as well as kanamycin against S. aureus ATCC 6538 (FIC = 0.25). The crystal violet assay revealed that the lowest concentration of AgNPs (0.125 μg mL^-1) reduced the development of biofilms of Listeria monocytogenes and Salmonella enterica, while the maximum resistance was shown by Salmonella infantis, its biofilm was reduced after exposure to a concentration of 512 μg mL^-1. A high inhibitory effect on the activity of bacterial hydrolases was observed by the FDA assay. AgNPs at a concentration of 0.125 μg mL^-1 reduced the hydrolytic activity of all biofilms formed by the tested pathogens, except E. coli ATCC 25922, P. aeruginosa, and Pectobacterium carotovorum (efficient concentration was 2-fold higher, at 0.25 μg mL^-1), while the hydrolytic activity of E. coli ATCC 8739, Salmonella infantis and S. aureus ATCC 6538 was suppressed after treatment with AgNPs at concentrations of 0.5, 2 and 8 μg mL^-1, respectively. Moreover, AgNPs inhibited fungal growth and spore germination of Botrytis cinerea, Phoma lingam, and Sclerotinia sclerotiorum. MIC and MFC values of AgNPs against spores of these fungal strains were determined at 64, 256, and 32 μg mL^-1, and zones of growth inhibition were 4.93, 9.54, and 3.41 mm, respectively.

Discussion

Fusarium culmorum strain JTW1 was found to be an eco-friendly biological system for an easy, efficient and inexpensive synthesis of AgNPs. In our study, the mycosynthesised AgNPs demonstrated remarkable antimicrobial (antibacterial and antifungal) and antibiofilm activities against a wide range of human and plant pathogenic bacteria and fungi singly and in combination with antibiotics. These AgNPs could be applied in medicine, agriculture, and food industry to control such pathogens that cause numerous human diseases and crop losses. However, before using them extensive animal studies are required to evaluate the toxicity, if any.

Inflammatory and pathological changes in Escherichia coli infected mice

Purpose

Understanding the inflammation and histopathological changes in vivo caused by Escherichia coli infection is of great significance for scientific research and clinical diagnosis.

Methods

Mice were randomly divided into 6 groups (N = 10) after adaptive feeding, and it challenged by intraperitoneal injection with different concentrations of E. coli ATCC25922. The survival situation within 7 days was recorded, and the half-lethal dose (LD₅₀) was calculated by Karber's method. After the end, the blood, heart, liver, spleen, lung, and kidney of the mice were collected. We detected the concentration of inflammatory cytokines (IL-6, IL-β, and TNF-α) and inducible nitric oxide synthase (iNOS) in serum by ELSIA. Organs were observed by histopathological staining and electron microscope observation.

Results

The LD₅₀ of mice infected with E. coli was 1.371∗10⁶ CFU/kg. The concentrations of IL-6, IL-β, and TNF-α increased with time after infection in mice, reaching the highest concentration on the 7th day. iNOS was significantly increased on the 1st day of infection, and then decreased over time (P < 0.01). Within a week after infection, the colony counts of the heart, liver, spleen, lung and kidney showed a first decrease, and then reached a surge on the 7th day. Pathological results showed that a small amount of mitochondrial swelling and autophagy were seen in the spleen, lung and kidney tissues of the infected group; and a small amount of secondary lysosomes and autophagy were also seen; but no pathological changes were found in the liver and heart.

Conclusion

Escherichia coli can cause inflammation and oxidative stress in mice, causing different degrees of damage to the spleen, lung, and kidney tissues, which provides theoretical support for inflammatory and pathological changes caused by Escherichia coli infection in vivo.

Current and Emerging Treatment Options for Multidrug Resistant Escherichia coli Urosepsis: A Review

Escherichia coli is a versatile commensal and pathogenic member of the human microflora. As the primary causative pathogen in urosepsis, E. coli places an immense burden on healthcare systems worldwide. To further exacerbate the issue, multi drug resistance (MDR) has spread rapidly through E. coli populations, making infections more troublesome and costlier to treat. This paper aimed to review the literature concerning the development of MDR in uropathogenic E. coli (UPEC) and explore the existing evidence of current and emerging treatment strategies. While some MDR strains maybe treated with β-lactam-β-lactamase inhibitor combinations as well as cephalosporins, cephamycin, temocillin and fosfomycin, current treatment strategies for many MDR UPEC strains are reliant on carbapenems. Carbapenem overreliance may contribute to the alarming dissemination of carbapenem-resistance amongst some UPEC communities, which has ushered in a new age of difficult to treat infections. Alternative treatment options for carbapenem resistant UPEC may include novel β-lactam-β-lactamase or carbapenemase inhibitor combinations, cefiderocol, polymyxins, tigecycline, aminoglycosides or fosfomycin. For metallo-β-lactamase producing strains (e.g., NDM, IMP-4), combinations of cefazidime-avibacam with aztreonam have been used. Additionally, the emergence of new antimicrobials brings new hope to the treatment of such infections. However, continued research is required to successfully bring these into the clinic for the treatment of MDR E. coli urosepsis.

Photodynamic antimicrobial chemotherapy with asymmetrical cationic or neutral metallophthalocyanines conjugated to amino-functionalized zinc oxide nanoparticles (spherical or pyramidal) against planktonic and biofilm microbial cultures

The synthesis and characterization of neutral zinc and indium substituted mercaptobenzothiazole substituted phthalocyanines (Pcs) and their respective cationic derivatives are presented. The phthalocyanines were further covalently linked to two differently shaped amino-functionalized ZnO nanoparticles (ZnONPs): namely nanospheres (NH₂-ZnONSp), and nanopyramids (NH₂-ZnONPy), to form corresponding nanoconjugates. The photophysicochemical properties of each nanocomposite were determined, and the Pc-ZnONPs produced high singlet oxygen quantum yields. The photodynamic antimicrobial chemotherapy activity was determined using planktonic and biofilm cells of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Candida albicans (C. albicans). The conjugates of the cationic Pc derivatives with ZnONPy produced the highest log reduction values (∼ 8 and above) with the complete elimination of all planktonic cells at 0.45 kJ/cm² for S. aureus and at 0.9 kJ/cm² for E. coli, and C. albicans. For biofilms log reduction values >3 for both S. aureus and E. coli were obtained. The conjugates of the cationic Pc derivatives with NH₂-ZnONPy showed great potential in eradicating mixed microbial biofilms.