Environmental Escherichia coli: ecology and public health implications-a review

Antimicrobial Activity of Apis mellifera Bee Venom Collected in Northern Peru

Due to the emergence of microorganisms resistant to antibiotics and the failure of antibiotic therapies, there is an urgent need to search for new therapeutic options, as well as new molecules with antimicrobial potential. The objective of the present study was to evaluate the in vitro antibacterial activity of Apis mellifera venom collected in the beekeeping areas of the city of Lambayeque in northern Peru against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Bee venom extraction was performed by electrical impulses and separated using the Amicon ultra centrifugal filter. Subsequently, the fractions were quantified by spectrometric 280 nm and evaluated under denaturant conditions in SDS-PAGE. The fractions were pitted against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, and Pseudomonas aeruginosa ATCC 27853. A purified fraction (PF) of the venom of A. mellifera and three low molecular weight bands of 7 KDa, 6 KDa, and 5 KDa were identified that showed activity against E. coli with a MIC of 6.88 µg/mL, while for P. aeruginosa and S. aureus, it did not present a MIC. No hemolytic activity at a concentration lower than 15.6 µg/mL and no antioxidant activity. The venom of A. mellifera contains a potential presence of peptides and a predilection of antibacterial activity against E. coli.

Estimating the effect of increasing ambient temperature on antimicrobial resistance in China: A nationwide ecological study with the difference-in-differences approach

Antimicrobial resistance (AMR) and the possible consequences of rising ambient temperatures brought on by global warming have been extensively discussed. However, the epidemiological evidence on the effects of temperature on AMR is rare and little is known about the role of socioeconomic inequities. This ecological study obtained 31 provinces AMR data of Escherichia Coli (E. coli) from the China Antimicrobial Resistance Surveillance System (CARSS) over the period from 2014 to 2020, which were linked to the meteorological and socioeconomic data published in the China Statistical Yearbook. Modified difference-in-differences (DID) analyses were performed to estimate the effect of ambient temperature on AMR of E. coli to third-generation cephalosporins (ceftriaxone and cefotaxime), carbapenems, and quinolones, adjusting for variations in meteorological and socioeconomic factors. We estimated that every 1 °C increase in average ambient temperature was associated with 2.71 % (95 % confidence interval [CI]: 1.20-4.24), 32.92 % (95 % CI: 15.62-52.81), and 1.81 % (95 % CI: 0.47-3.16) increase in the prevalence of E. coli resistance to third-generation cephalosporins (ceftriaxone and cefotaxime), carbapenems and quinolones, respectively. The link was more profound in the regions with lower temperature and a median level of average humidity, and the regions with lower income, lower expenditure (in economics), lower health resources, and lower hospital admissions. Neither the replacement of the temperature variable nor the alternative approaches for confounding adjustment changed the positive association between ambient temperature and AMR. In general, there exists a positive association between ambient temperature and AMR, although the strength of such an association varies by socioeconomic and health services factors. The association is possibly nonlinear, especially for E. coli resistance to third-generation cephalosporins. The findings suggest that AMR control programs should explicitly incorporate weather patterns to increase their effectiveness.

Breaking Down the Gut: A Case of Severe Toxin-Mediated Colitis

Shiga-toxin-producing Escherichia coli (STEC) is a worldwide, foodborne pathogen that can lead to life-threatening complications. Transmission has been associated with undercooked meat products, contaminated food and water sources, person-to-person contact, and direct exposure to infected farm animals. As the name suggests, the major virulence factors contributing to its pathogenicity are Shiga toxins, which can cause a spectrum of clinical presentations ranging from mild watery diarrhea to severe hemorrhagic colitis due to its toxic effects on the gastrointestinal tract. We report a case of a 21-year-old man seeking medical attention due to severe crampy abdominal pain and bloody diarrhea who was ultimately diagnosed with a less commonly encountered severe form of colitis in the setting of STEC infection. Thorough investigations while maintaining a high level of clinical suspicion allowed prompt medical care with a complete resolution of symptoms. This case highlights the importance of having high clinical suspicion for STEC even with more severe forms of colitis and sheds light on the role of medical personnel in managing such cases.

Persistence of E. coli in Streambed Sediment Contaminated with Faeces from Dairy Cows, Geese, and Deer: Legacy Risks to Environment and Health

Legacy stores of faecal pollution in streambed sediments can result in delayed impacts on environmental quality and human health if resuspended into the overlying water column. Different catchment sources of faecal pollution can contribute to a legacy store of microbial pollutants, with size of stores influenced by microbial die-off and faecal accrual rates in the streambed. The aim of this study was to use a mesocosm experiment to characterise the persistence of E. coli derived from faeces of dairy cows, deer, and geese once introduced to streambed sediment under different temperature regimes. The settling rate of solid constituents of faecal material into streambed sediment once delivered into an aquatic environment was also quantified. The persistence patterns of E. coli in streambed sediment were found to vary as a function of faecal source and temperature; die-off of E. coli in sediment contaminated with goose faeces was more rapid than in sediments contaminated with dairy cow or deer faeces. Goose faeces also recorded a more rapid settling rate of faecal particles through the water column relative to dairy cow and deer faeces, suggesting a more efficient delivery of E. coli to streambed sediments associated with this faecal source. Our findings provide new evidence to improve understanding of the potential longer-term risks to both the environment and public health posed by sediments when contaminated with livestock, wildlife, and wildfowl faeces.

Whole genome sequencing and annotation of a lysogenic phage vB_EcoP_DE5 isolated from donkey-derived Escherichia coli

A lysogenic phage vB_EcoP_DE5 (hereafter designated DE5) was isolated from donkey-derived Escherichia coli. The bacteriophage was examined by transmission electron microscopy, and the result showed that DE5 belonged to the genus Kuravirus. DE5 was sensitive to changes in temperature and pH, and it could maintain its activity at pH 7 and below 60 ℃. The whole genome sequencing revealed that DE5 had a double-stranded DNA genome of 77, 305 bp with 42.09% G+C content. A total of 126 open reading frames (ORFs) were identified, including functional genes related to phage integration, DNA replication and modification, transcriptional regulation, structural and packaging proteins, and host cell lysis. One phage integrase gene, one autotransporter adhesin gene, and one tRNA gene were predicted in the whole genome, and no genes associated with drug resistance were identified. The phage DE5 integrase contained 187 amino acids and belonged to the small serine recombinase family. BLASTn analysis revealed that phage DE5 had a high-sequence identity (96%) with E. coli phage SU10. Phylogenetic analysis showed that phage DE5 was a member of the genus Kuravirus. The whole genome sequencing of lysogenic phage DE5 enhanced our understanding of lysogenic phages and their therapeutic applications.

Detection of antibiotic-resistant canine origin Escherichia coli and the synergistic effect of magnolol in reducing the resistance of multidrug-resistant Escherichia coli

Background

The development of antimicrobial resistance in the opportunistic pathogen Escherichia coli has become a global public health concern. Due to daily close contact, dogs kept as pets share the same E. coli with their owners. Therefore, the detection of antimicrobial resistance in canine E. coli is important, as the results could provide guidance for the future use of antibiotics. This study aimed to detect the prevalence of antibiotic-resistance of canine origin E. coli in Shaanxi province and to explore the inhibition effect of magnolol combined with cefquinome on MDR E. coli, so as to provide evidence for the use of antibiotics.

Methods

Canine fecal samples were collected from animal hospitals. The E. coli isolates were separated and purified using various indicator media and polymerase chain reaction (PCR). Drug-resistance genes [aacC2, ant(3')-I, aph(3')-II, aac(6')-Ib-cr, aac(3')-IIe, blaKPC, blaIMP−4, blaOXA, blaCMY, blaTEM−1, blaSHV, blaCTX−M−1, blaCTX−M−9, Qnra, Qnrb, Qnrs, TetA, TetB, TetM, Ermb] were also detected by PCR. The minimum inhibitory concentration (MIC) was determined for 10 antibiotics using the broth-microdilution method. Synergistic activity of magnolol and cefquinome against multidrug-resistant (MDR) E. coli strains was investigated using checkerboard assays, time-kill curves, and drug-resistance curves.

Results

A total of 101 E. coli strains were isolated from 158 fecal samples collected from animal hospitals. MIC determinations showed that 75.25% (76/101) of the E. coli strains were MDR. A total of 22 drug-resistance genes were detected among the 101 strains. The blaTEM−1gene exhibited the highest detection rate (89.77%). The TetA and Sul gene also exhibited high detection rate (66.34 and 53.47%, respectively). Carbapenem-resistant E. coli strains were found in Shangluo and Yan'an. Additionally, in MDR E. coli initially resistant to cefquinome, magnolol increased the susceptibility to cefquinome, with an FICI (Fractional Inhibitory Concentration Index) between 0.125 and 0.5, indicating stable synergy. Furthermore, magnolol enhanced the killing effect of cefquinome against MDR E. coli. Resistance of MDR E. coli to cefquinome decreased markedly after treatment with magnolol for 15 generations.

Conclusion

Our study indicates that antibiotic-resistance E. coli has been found in domestic dogs. After treatment with magnolol extracted from the Chinese herb Houpo (Magnolia officinalis), the sensitivity of MDR E. coli to cefquinome was enhanced, indicating that magnolol reverses the resistance of MDR E. coli. The results of this study thus provide reference for the control of E. coli resistance.

The first use of LC-MS/MS proteomic approach in the brown mussel Perna perna after bacterial challenge: Searching for key proteins on immune response

The brown mussel Perna perna is a valuable fishing resource, primarily in tropical and subtropical coastal regions. Because of their filter-feeding habits, mussels are directly exposed to bacteria in the water column. Escherichia coli (EC) and Salmonella enterica (SE) inhabit human guts and reach the marine environment through anthropogenic sources, such as sewage. Vibrio parahaemolyticus (VP) is indigenous to coastal ecosystems but can be harmful to shellfish. In this study, we aimed to assess the protein profile of the hepatopancreas of P. perna mussel challenged by introduced - E. coli and S. enterica - and indigenous marine bacteria - V. parahaemolyticus. Bacterial-challenge groups were compared with non-injected (NC) and injected control (IC) - that consisted in mussels not challenged and mussels injected with sterile PBS-NaCl, respectively. Through LC-MS/MS proteomic analysis, 3805 proteins were found in the hepatopancreas of P. perna. From the total, 597 were significantly different among conditions. Mussels injected with VP presented 343 proteins downregulated compared with all the other conditions, suggesting that VP suppresses their immune response. Particularly, 31 altered proteins - upregulated or downregulated - for one or more challenge groups (EC, SE, and VP) compared with controls (NC and IC) are discussed in detail in the paper. For the three tested bacteria, significantly different proteins were found to perform critical roles in immune response at all levels, namely: recognition and signal transduction; transcription; RNA processing; translation and protein processing; secretion; and humoral effectors. This is the first shotgun proteomic study in P. perna mussel, therefore providing an overview of the protein profile of the mussel hepatopancreas, focused on the immune response against bacteria. Hence, it is possible to understand the immune-bacteria relationship at molecular levels better. This knowledge can support the development of strategies and tools to be applied to coastal marine resource management and contribute to the sustainability of coastal systems.

Atmospheric microplastics: exposure, toxicity, and detrimental health effects

Microplastics (MPs) are micro-particulate pollutants present in all environments whose ubiquity leads humans to unavoidable exposure. Due to low density, MPs also accumulate in the atmosphere, where they are easily transported worldwide and come into direct contact with the human body by inhalation or ingestion, causing detrimental health effects. This literature review presents the sources of atmospheric MPs pollution, transport routes, physicochemical characteristics, and environmental interactions. The document also explains the implications for human health and analyzes the risk of exposure based on the potential toxicity and the concentration in the atmosphere. MPs' toxicity lies in their physical characteristics, chemical composition, environmental interactions, and degree of aging. The abundance and concentration of these microparticles are associated with nearby production sources and their displacement in the atmosphere. The above elements are presented in an integrated way to facilitate a better understanding of the associated risk. The investigation results encourage the development of future research that delves into the health implications of exposure to airborne MPs and raises awareness of the risks of current plastic pollution to promote the establishment of relevant mitigation policies and procedures.

Transplantation of Aceh cattle ovary into the uterus of pseudopregnant local rabbits: Effect of post-transplant stress on uterine histopathology and ovarian follicle dynamics

Background and Aim

The increase in the levels of the cortisol hormone caused by the stress conditions generated by an ovary transplantation procedure can damage the uterus of the transplant recipient as well as the transplanted ovaries. This study aimed to analyze the histopathological changes that occur in the uterine horn of pseudopregnant local rabbits (recipients), as well as the ovarian follicular integrity of the donor Aceh cattle after transplantation.

Materials and Methods

After 30 days of adaptation, all rabbits were divided into three treatment groups: R1 (the group of rabbits that underwent ovarian transplantation for 3 days, n = 5), R2 (the group of rabbits that underwent ovarian transplantation for 5 days, n = 5), and R3 (the group of rabbits that underwent ovarian transplantation for 7 days, n = 5). Pseudopregnancy induction was performed using the pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) methods. The rabbits were injected with 100 IU of PMSG intramuscularly, followed by an injection of 75 IU of hCG intravenously 3 days later. Ovarian transplantation was performed on day 8 (day 0 was the day of hCG injection). The concentration of cortisol hormone metabolites was measured from fecal samples using an enzyme-linked immunosorbent assay technique. The uterus and ovaries were collected for histopathological and follicular dynamics examination after the transplantation process was completed.

Results

The mean cortisol levels (ng/g) recorded before versus after the transplant in the R1, R2, and R3 groups were 146.23 ± 17.60 versus 338.84 ± 302.79, 128.97 ± 81.56 versus 174.79 ± 101.70, and 124.88 ± 43.61 versus 321.91 ± 221.63 (p < 0.05), respectively. The examination of the histopathological appearance of the uterus revealed edema in the uterine lumen, hyperemia and hemorrhage in the endometrium, necrosis of the epithelium, and infiltration of inflammatory cells. Hemorrhage and hyperemia were severe and filled the endometrium in the R1 compared with the R2 and R3 animals. Ovarian follicle development occurred in all treatment groups, although some histopathological features were observed. The number of tertiary follicles in R1, R2, and R3 animals was 24.67 ± 7.37, 20.67 ± 7.57, and 9.67 ± 3.79 (p < 0.05), respectively.

Conclusion

Based on the results of this study, it can be concluded that the transplantation of ovaries from Aceh cattle into pseudopregnant local rabbits triggered an increase in the levels of the cortisol hormone and uterine histological changes; however, follicles were still detected at various stages of development in the transplanted Aceh cattle ovaries. The results of this study are valuable for clinicians and researchers because they provide information regarding an alternative in vivo ovarian preservation technique using pseudopregnant rabbits.

Effect of a karst system (France) on extended spectrum beta-lactamase (ESBL)-producing Escherichia coli

Karst aquifers are an important water resource worldwide particularly exposed to anthropogenic pollution, including antibiotic-resistance. The release of antibiotic-resistant bacterial pathogens in the environment is a major public health challenge worldwide. In this One Health study, we aimed to determine the effect of karst on antibiotic-resistant bacteria. For this purpose, we determined the concentrations of extended-spectrum β-lactamases-producing Escherichia coli (ESBL-Ec) for 92 weeks in a rural karst hydrosystem providing drinking water. ESBL-Ec isolates (n = 130) were sequenced by whole genome sequencing. We analysed the isolates at different levels of granularity, i.e., phylogroup, sequence type, presence of antibiotic-resistance genes, mutations conferring antibiotic-resistance, and virulence genes. The ESBL-Ec concentrations were spatially and temporally heterogeneous in the studied karst hydrosystem. ESBL-Ec isolates survived in the karst and their concentrations were mostly explained by the hydrodynamic of the hydrosystem. We demonstrate that the studied karst has no filtration effect on ESBL-Ec, either quantitatively (i.e., in the ESBL-Ec concentrations) or qualitatively (i.e., in the genetic characteristics of ESBL-Ec isolates).

Modelling a dynamic magneto-agglutination bioassay

The process of developing an end-to-end model of a magneto-immunoassay is described, simulating the agglutination effect due to the specific binding of bacteria to paramagnetic particles. After establishing the properties of the dose-specific agglutination through direct imaging, a microfluidic assay was used to demonstrate changes in the magnetophoretic transport dynamics of agglutinated clusters via transient inductive magentometer measurements. End-to-end mathematical modelling is used to establish the physical processes underlying the assay. First, a modified form of Becker-Döring nucleation kinetic equations is used to establish a relationship between analyte dose and average cluster size. Next, Stokes flow equations are used to establish a relationship between cluster size and speed of motion within the fluid chamber. This predicts a cluster-size dynamic profile of concentration of PMPs versus time when the magnetic field is switched between the two actuated magnets. Finally, inductive modelling is carried out to predict the response of the magnetometer circuit in response to the dynamics of magnetic clusters. The predictions of this model are shown to agree well with the results of experiments, and to predict the shape of the dose-response curve.

Carriage of Extended Spectrum Beta Lactamase-Producing Escherichia coli: Prevalence and Factors Associated with Fecal Colonization of Dogs from a Pet Clinic in Lower Saxony, Germany

Extended spectrum beta-lactamase (ESBL)-producing Escherichia coli are an emerging problem in veterinary and human medicine. Our study concentrated on the estimation of the prevalence and factors associated with the carriage of ESBL-producing E. coli in dogs who visited a veterinary clinic in northern Germany in 2017. For this reason, 1000 patients (healthy and sick dogs) were tested, resulting in 1000 samples originating from rectal swabs. Additional data were collected using a self-reported questionnaire that was completed by the dog owner. Factors associated with ESBL carriage were considered for further modeling if p < 0.05 using a two-sided Fisher test. Using a backward elimination procedure, the variables for the final multivariable logistic regression model were identified. In total, 8.9% of the dogs tested were positive for carriage of ESBL-producing E. coli. Seven factors were associated with the colonization of dogs with ESBL-E. coli within the multivariable model, namely husbandry system (p = 0.0019, OR = 3.00; 95% CI: 1.50-6.00), contact with puppies (p = 0.0044, OR = 2.43; 95% CI: 1.32-4.46), feeding of raw meat (p = 0.011, OR = 2.28; 95% CI: 1.21-4.31), food residues (p = 0.0151, OR = 2.31; 95% CI: 1.18-4.53) and food supplements (p = 0.0487, OR = 0.426; 95% CI: 0.18-0.96), and antibiotic treatments of dogs (p = 0.0005, OR = 3.030; 95% CI: 1.62-5.68) or owners (p = 0.041, OR = 2.74; 95% CI: 1.04-7.19) prior to the study. These factors refer to the animals themselves as well as to the owners and their habits or medical treatments. Although the causality and direction of transmission from owners to their dogs cannot be proven, the factor of antibiotic treatment of the owner is clearly associated with the dog's status.

Biofilm formation, antibiotic resistance and genotyping of Shiga toxin-producing Escherichia coli isolated from retail chicken meats

1. The Shiga toxin-producing Escherichia coli (STEC) is a hazardous zoonotic agent for chicken meat consumers. This study determined the serogroups and evaluated the virulence genes, antibiotic resistance, biofilm-forming profiles and genetic relationships of STEC isolates in chicken meat.2. A total of 100 samples belonging to dressed-whole chicken and different parts of the chicken (wing, breast, thigh, drumstick) were collected between September and November 2019 from different retail markets in Kayseri, Türkiye.3. Phenotypic (identification, disc diffusion test, Congo red agar and microtitre plate tests) and molecular tests (identification, serogrouping, virulence factors, biofilm, antibiotic susceptibility, 16S rRNA sequencing and enterobacterial repetitive intergenic consensus-PCR for typing of the isolates) were carried out.4. E. coli was isolated from 35% of the samples and 35% of the samples harboured at least one STEC. Among 35 STEC isolates, 3 (8.5%), 6 (17.1%), 2 (5.7%) and 3 (8.5%) were found to be positive for fliCH2, fliCH8, fliCH11, fliCH19 genes, respectively. Out of 35 STEC positive isolates, 4 (11.4%) were identified as E. coli O157, from which 2 (5.7%) were E. coli O157:H7. E. coli O157 was detected in two (10%), one (5%), one (5%) of the thigh, drumstick and whole chicken samples, respectively.5. Biofilm-forming ability was reported in 33 (94.2%) of 35 E. coli isolates, whilst the biofilm-associated genes detected among 35 STEC isolates included csgA (88.5%), fimH (88.5%), bcsA (85.7%), agn43 (14.2%) and papC (8.5%). The STEC strains showed resistance against ampicillin (88.5%) and erythromycin (88.5%), followed by tetracycline (74.2%) and gentamicin (25.7%). However, the distribution of isolates harbouring bla_CMY, ere(A), tet(A) and aac(3)-IV antibiotic resistance genes was found to be 17.1%, 11.4%, 85.7% and 5.7%, respectively.6. ERIC-PCR showed that E. coli strains obtained from different parts and whole of chicken samples had genetic diversities. ERIC-PCR patterns grouped strains of 35 STEC into eight clusters designated A-H, with 73% similarity. Proper hygiene measures and staff training are essential for public health during poultry processing and in retail stores to control STEC.

Prevalence and Characterization of CRISPR Locus 2.1 Spacers in Escherichia coli Isolates Obtained from Feces of Animals and Humans

The clustered regularly interspaced short palindromic repeat (CRISPR) has been studied as an immune system in prokaryotes for the survival of bacteriophages. The CRISPR system in prokaryotes records the invasion of bacteriophages or other genetic materials in CRISPR loci. Accordingly, CRISPR loci can reveal a history of infection records of bacteriophages and other genetic materials. Therefore, identification of the CRISPR array may help trace the events that bacteria have undergone. In this study, we characterized and identified the spacers of the CRISPR loci in Escherichia coli isolates obtained from the feces of animals and humans. Most CRISPR spacers were found to stem from phages. Although we did not find any patterns in CRISPR spacers according to sources, our results showed that phage-derived spacers mainly originated from the families Inoviridae, Myoviridae, Podoviridae, and Siphoviridae and the order Caudovirales, whereas plasmid-derived CRISPR spacers were mainly from the Enterobacteriaceae family. In addition, it is worth noting that the isolates from each animal and human source harbored source-specific spacers. Considering that some of these taxa are likely found in the gut of mammalian animals, CRISPR spacers identified in these E. coli isolates were likely derived from the bacteriophageome and microbiome in closed gut environments. Although the bacteriophageome database limits the characterization of CRISPR arrays, the present study showed that some spacers were specifically found in both animal and human sources. Thus, this finding may suggest the possible use of E. coli CRISPR spacers as a microbial source tracking tool. IMPORTANCE We characterized spacers of CRISPR locus 2.1 in E. coli isolates obtained from the feces of various sources. Phage-derived CRISPR spacers are mainly acquired from the order Caudovirales, and plasmid-derived CRISPR spacers are mostly from the Enterobacteriaceae family. This is thought to reflect the microbiome and phageome of the gut environment of the sources. Hence, spacers may help track the encounter of bacterial cells with bacterial cells, viruses, or other genetic materials. Interestingly, source-specific spacers are also observed. The identification of source-specific spacers is thought to help develop the methodology of microbial source tracking and understanding the interactions between viruses and bacteria. However, very few spacers have been uncovered to track where they originate. The accumulation of genome sequences can help identify the hosts of spacers and can be applied for microbial source tracking.

Genetic Determinants of Escherichia coli Survival in Beach Sand

Escherichia coli contain a high level of genetic diversity and are generally associated with the guts of warm-blooded animals but have also been isolated from secondary habitats outside hosts. We used E. coli isolates from previous in situ microcosm experiments conducted under actual beach conditions and performed population-level genomic analysis to identify accessory genes associated with survival within the beach sand environment. E. coli strains capable of surviving had been selected for by seeding isolates originating from sand, sewage, and gull waste (n = 528; 176 from each source) into sand, which was sealed in microcosm chambers and buried for 45 days in the backshore beach of Lake Michigan. In the current work, survival-associated genes were identified by comparing the pangenome of viable E. coli populations at the end of the microcosm experiment with the original isolate collection and identifying loci enriched in the out put samples. We found that environmental survival was associated with a wide variety of genetic factors, with the majority corresponding to metabolism enzymes and transport proteins. Of the 414 unique functions identified, most were present across E. coli phylogroups, except B2 which is often associated with human pathogens. Gene modules that were enriched in surviving populations included a betaine biosynthesis pathway, which produces an osmoprotectant, and the GABA (gamma-aminobutyrate) biosynthesis pathway, which aids in pH homeostasis and nutrient use versatility. Overall, these results demonstrate that the genetic flexibility within this species allows for survival in the environment for extended periods. IMPORTANCE Escherichia coli is commonly used as an indicator of recent fecal pollution in recreational water despite its known ability to survive in secondary environments, such as beach sand. These long-term survivors from sand reservoirs can be introduced into the water column through wave action or runoff during precipitation events, thereby impacting the perception of local water quality. Current beach monitoring methods cannot differentiate long-term environmental survivors from E. coli derived from recent fecal input, resulting in inaccurate monitoring results and unnecessary beach closures. This work identified the genetic factors that are associated with long-term survivors, providing insight into the mechanistic basis for E. coli accumulation in beach sand. A greater understanding of the intrinsic ability of E. coli to survive long-term and conditions that promote such survival will provide evidence of the limitations of beach water quality assessments using this indicator.

trans-Cinnamaldehyde as a Novel Candidate to Overcome Bacterial Resistance: An Overview of In Vitro Studies

The increasing of drug-resistant bacteria and the scanty availability of novel effective antibacterial agents represent alarming problems of the modern society, which stimulated researchers to investigate novel strategies to replace or assist synthetic antibiotics. A great deal of attention has been devoted over the years to essential oils that contain mixtures of volatile compounds and have been traditionally exploited as antimicrobial remedies. Among the essential oil phytochemicals, remarkable antimicrobial and antibiotic-potentiating activities have been highlighted for cinnamaldehyde, an α,β-unsaturated aldehyde, particularly abundant in the essential oils of Cinnamomum spp., and widely used as a food additive in industrial products. In line with this evidence, in the present study, an overview of the available literature has been carried out in order to define the bacterial sensitizing profile of cinnamaldehyde. In vitro studies displayed the ability of the substance to resensitize microbial strains to drugs and increase the efficacy of different antibiotics, especially cefotaxime, ciprofloxacin, and gentamicin; however, in vivo, and clinical trials are lacking. Based on the collected findings, cinnamaldehyde appears to be of interest as an adjuvant agent to overcome superbug infections and antibiotic resistance; however, future more in-dept studies and clinical investigations should be encouraged to clarify its efficacy and the mechanisms involved.

Highly-Sensitive, Label-Free Detection of Microorganisms and Viruses via Interferometric Reflectance Imaging Sensor

Pathogenic microorganisms and viruses can easily transfer from one host to another and cause disease in humans. The determination of these pathogens in a time- and cost-effective way is an extreme challenge for researchers. Rapid and label-free detection of pathogenic microorganisms and viruses is critical in ensuring rapid and appropriate treatment. Sensor technologies have shown considerable advancements in viral diagnostics, demonstrating their great potential for being fast and sensitive detection platforms. In this review, we present a summary of the use of an interferometric reflectance imaging sensor (IRIS) for the detection of microorganisms. We highlight low magnification modality of IRIS as an ensemble biomolecular mass measurement technique and high magnification modality for the digital detection of individual nanoparticles and viruses. We discuss the two different modalities of IRIS and their applications in the sensitive detection of microorganisms and viruses.

Differentiation of Escherichia fergusonii and Escherichia coli Isolated from Patients with Inflammatory Bowel Disease/Ischemic Colitis and Their Antimicrobial Susceptibility Patterns

Genotypically, 16S rRNA gene sequence analysis clearly differentiates between species. However, species delineation between Escherichia fergusonii and Escherichia coli is much more difficult and cannot be distinguished by 16S rRNA gene sequences alone. Hence, in this study, we attempted to differentiate E. fergusonii and E. coli isolated from faecal samples of disease-associated Korean individuals with inflammatory bowel disease (IBD)/ischemic colitis (IC) and test the antimicrobial susceptibility patterns of isolated strains. Phylogenetic analysis was performed using the adenylate kinase (adk) housekeeping gene from the E. coli multi locus sequence typing (MLST) scheme. Antimicrobial susceptibility and minimum inhibitory concentration (MIC) of all disease-associated strains in addition to healthy control isolates to 14 antibiotics were determined by broth microdilution-based technique. Next, 83 isolates from 11 disease-associated faecal samples were identified as E. fergusonii using 16S rRNA gene sequence analysis. Phylogenetic analysis using the adk gene from E. coli MLST scheme revealed that most of the strains (94%) were E. coli. A total of 58 resistance patterns were obtained from 83 strains of disease-associated (IBD/IC) isolates. All isolates were resistant to at least one tested antimicrobial agent, with the highest resistance against erythromycin (88.0%), ampicillin (86.7%), ciprofloxacin (73.5%), cephalothin (72.3%), gentamicin (59%), trimethoprim-sulfamethoxazole (53%), cefotaxime (49.4%), and ceftriaxone (48.2%). A total of 90.7% of isolates were extended-spectrum beta-lactamase (ESBL)-producers among the resistant strains to third-generation cephalosporins (cefotaxime or ceftriaxone). ESBL-producing E. coli isolates from patients with Crohn's disease (CD), ulcerative colitis (UC), and ischemic colitis (IC) were 92.3%, 82.4%, and 100%, respectively. In conclusion, adk-based phylogenetic analysis may be the most accurate method for distinguishing E. coli and E. fergusonii from Escherichia genus. We identified four loci in adk gene sequences which makes it easier to discriminate between E. coli and E. fergusonii. Additionally, we believe that gut colonization by multidrug-resistant ESBL-producing E. coli may play a significant role in IBD/IC pathogenesis.

Escherichia coli Contamination of Water for Human Consumption and Its Associated Factors in Peru: A Cross-Sectional Study

The objective of the study was to determine the factors associated with the presence of Escherichia coli contamination in water supplies for human consumption in Peru. A secondary analysis of the Food and Nutrition Surveillance by Life Stages survey (VIANEV) of 2017-2018 was performed. The presence of E. coli contamination in the water samples for human consumption of the households evaluated was defined as a dependent variable. A supply was considered contaminated when there was at least 1 colony-forming unit of E. coli in 100 mL of water for human consumption. Data from 886 participants were analyzed. It was found that 25.2% of household water supply sources for human consumption had E. coli at the time of sampling. Water reservoirs such as buckets or other containers (adjusted prevalence ratio [aPR]: 1.15; 95% confidence interval [CI]: 1.18-1.93), households belonging to a poor wealth quintile (aPR: 1.82; 95% CI: 1.01-3.25), residing in a rural area (aPR: 1.36; 95% CI: 1.01-1.83), and having a low human development index (aPR: 2.12; 95% CI: 1.15-3.91) were more likely to contain E. coli in water supplies for human consumption. However, households with chlorine concentrations of 0.5 mg/L or more in water (aPR: 0.20; 95% CI: 0.11-0.33) and with household members with a higher education (aPR: 0.67; 95% CI: 0.45-0.99) were less likely to contain E. coli in drinking-water supplies. From 2017 to 2018, one in four Peruvians had contamination by E. coli in the water supply to their homes, which was associated with sociodemographic factors, management, and water treatment.

Nanomaterials to address the genesis of antibiotic resistance in Escherichia coli

Escherichia is a genus of prokaryotic gram-negative bacteria which forms a vital component of the gut microbiota of homeotherms including humans. Many members of this genus are commensals and pathogenic strains, which are responsible for some of the most common bacterial infections and can be fatal, particularly in the case of newborns and children. The fecal matter in wastewater treatment plants serves as major environmental sinks for the accumulation of Escherichia. The rise in antibiotic pollution and the lateral gene exchange of antibiotic-resistant genes have created antibiotic-resistant Escherichia strains that are often called superbugs. Antibiotic resistance has reached a crisis level that nowadays existing antibiotics are no longer effective. One way of tackling this emerging concern is by using nanomaterials. Punitively, nanomaterials can be used by conjugating with antibodies, biomolecules, and peptides to reduce antibiotic usage, whereas, preventatively, they can be used as either nano-antimicrobial additives or nano-photocatalytic sheets to reduce the microbial population and target the superbugs of environmental Escherichia. In this review, we have explored the threat posed by pathogenic Escherichia strains in the environment, especially in the context of antibiotic-resistant strains. Along with this, we have discussed some nanomaterial-mediated strategies in which the problem can be addressed by using nanomaterials as nanophotocatalytics, antimicrobial additives, drugs, and drug conjugates. This review also presents a brief overview of the ecological threats posed by the overuse of nanomaterials which warrants a balanced and judicious approach to the problem.

The challenges in the identification of Escherichia coli from environmental samples and their genetic characterization

Escherichia coli bacteria are an essential indicator in evaluations of environmental pollution, which is why they must be correctly identified. This study aimed to determine the applicability of various methods for identifying E. coli strains in environmental samples. Bacterial strains preliminary selected on mFc and Chromocult media as E. coli were identified using MALDI Biotyper techniques, based on the presence of genes characteristic of E. coli (uidA, uspA, yaiO), as well as by 16S rRNA gene sequencing. The virulence and antibiotic resistance genes pattern of bacterial strains were also analyzed to investigate the prevalence of factors that may indicate adaptation to unsupportive environmental conditions and could have any significance in further identification of E. coli. Of the strains that had been initially identified as E. coli with culture-based methods, 36-81% were classified as E. coli with the use of selected techniques. The value of Cohen's kappa revealed the highest degree of agreement between the results of 16S rRNA gene sequencing, the results obtained in the MALDI Biotyper system, and the results of the analysis based on the presence of the yaiO gene. The results of this study could help in the selection of more accurate and reliable methods which can be used in a preliminary screening and more precise identification of E. coli isolated from environmental samples.

Antimicrobial resistance genes of Escherichia coli, a bacterium of "One Health" importance in South Africa: Systematic review and meta-analysis

This is a systematic review and meta-analysis that evaluated the prevalence of Escherichia coli antibiotic-resistant genes (ARGs) in animals, humans, and the environment in South Africa. This study followed Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to search and use literature published between 1 January 2000 to 12 December 2021, on the prevalence of South African E. coli isolates' ARGs. Articles were downloaded from African Journals Online, PubMed, ScienceDirect, Scopus, and Google Scholar search engines. A random effects meta-analysis was used to estimate the antibiotic-resistant genes of E. coli in animals, humans, and the environment. Out of 10764 published articles, only 23 studies met the inclusion criteria. The obtained results indicated that the pooled prevalence estimates (PPE) of E. coli ARGs was 36.3%, 34.4%, 32.9%, and 28.8% for bla_TEM-M-1 , ampC, tetA, and bla _TEM, respectively. Eight ARGs (bla_CTX-M , bla_CTX-M-1 , bla_TEM , tetA, tetB, sul1, sulII, and aadA) were detected in humans, animals and the environmental samples. Human E. coli isolate samples harboured 38% of the ARGs. Analyzed data from this study highlights the occurrence of ARGs in E. coli isolates from animals, humans, and environmental samples in South Africa. Therefore, there is a necessity to develop a comprehensive "One Health" strategy to assess antibiotics use in order to understand the causes and dynamics of antibiotic resistance development, as such information will enable the formulation of intervention strategies to stop the spread of ARGs in the future.

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.

Effects of landscape characteristics, anthropogenic factors, and seasonality on water quality in Portland, Oregon

Urban areas often struggle with deteriorated water quality because of complex interactions between landscape factors and climatic variables. However, few studies have considered the effects of landscape variables on water quality at a sub-500-m scale. We conducted a spatial statistical analysis of six pollutants for 128 water quality stations in four watersheds around Portland, Oregon, using data from 2015 to 2021 for the wet season at two microscales (100 m and 250 m buffers). E. coli was associated with land cover, soil type, topography, and pipe length, while lead variations were best explained by topographic variables. Developed land cover and impervious surface explained variations in nitrate, while orthophosphate was associated with mean elevation. Models for zinc included land cover and topographic variables in addition to pipe length. Spatial regression models better explain variations in water quality than ordinary least squares models, indicating strong spatial autocorrelation for some variables. Our findings provide valuable insights to city planners and researchers seeking to improve water quality in metropolitan areas by manipulating city landscapes.

Presence of Certain Foodborne Pathogens in Traditional Balearic Islands' Meat, Pastry, and Cheese Specialties Supported by European Union Quality Schemes, from 2018 to 2021

The cuisine of the Balearic Islands (Spain, southern Europe) has several products of a great tradition, recognized worldwide and covered by European Union quality schemes, such as Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI). Among them, the most emblematic products are sobrasada de Mallorca (a type of raw curated pork meat), ensaimada de Mallorca (pastry product), and Mahón-Menorca cheese (cow's milk cheese). During 4 consecutive years (2018-2021), the presence/absence of Escherichia coli β-glucuronidase positive (henceforth as E. coli), Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus in these products has been monitored, as well as the total yeast and mold count in ensaimada de Mallorca. The results of the microbiological analysis showed that sobrasada presented similar microbiological patterns to those of other raw curated meat products (some presence of E. coli and L. monocytogenes). Furthermore, the sobrasada de Mallorca made with white pork tended to be positive in E. coli compared to other sobrasada subtypes. In the case of ensaimada, only a reduced number of cases within filled ensaimadas (with higher moisture content) presented unacceptable mold and yeast counts (>500 colony-forming unit [CFU]/g). Finally, the Mahón-Menorca cheese presented a surprising microbiology pattern: higher E. coli contamination in the pasteurized milk cheese compared to its raw counterpart. This pattern was observed for all the years, being statistically significant in 2020. This study has detected good microbiological status in the three traditional products studied. However, worrisome issues in Good Hygienic Practices have been detected for some companies that produce pasteurized milk Mahón-Menorca cheese under the PDO quality label. The companies involved and even the competent authorities should address these problems to correct this deviation in food security.

Towards the standardization of Enterococcus culture methods for waterborne antibiotic resistance monitoring: A critical review of trends across studies

Antibiotic resistance is a major 21^st century One Health (humans, animals, environment) challenge whose spread limits options to treat bacterial infections. There is growing interest in monitoring water environments, including surface water and wastewater, which have been identified as key recipients, pathways, and sources of antibiotic resistant bacteria (ARB). Aquatic environments also facilitate the transmission and amplification of ARB. Enterococcus spp. often carry clinically-important antibiotic resistance genes and are of interest as environmental monitoring targets. Enterococcus spp. are Gram-positive bacteria that are typically of fecal origin; however, they are also found in relevant environmental niches, with various species and strains that are opportunistic human pathogens. Although the value of environmental monitoring of antibiotic-resistant Enterococcus has been recognized by both national and international organizations, lack of procedural standardization has hindered generation of comparable data needed to implement integrated surveillance programs. Here we provide a comprehensive methodological review to assess the techniques used for the culturing and characterization of antibiotic-resistant Enterococcus across water matrices for the purpose of environmental monitoring. We analyzed 117 peer-reviewed articles from 33 countries across six continents. The goal of this review is to provide a critical analysis of (i) the various methods applied globally for isolation, confirmation, and speciation of Enterococcus isolates, (ii) the different methods for profiling antibiotic resistance among enterococci, and (iii) the current prevalence of resistance to clinically-relevant antibiotics among Enterococcus spp. isolated from various environments. Finally, we provide advice regarding a path forward for standardizing culturing of Enterococcus spp. for the purpose of antibiotic resistance monitoring in wastewater and wastewater-influenced waters within a global surveillance framework.

Escherichia coli in different animal feces: phylotypes and virulence genes

In this study, it was aimed to determine the phylogroups of Escherichia coli isolates from horse, cat, dog, sheep, cattle, and chicken feces samples and to investigate some important virulence genes of the isolates. For this purpose, a total of 600 feces samples, 100 from each animal species, were used as material. For the isolation of E.coli, feces samples were directly inoculated on MacConkey agar. The identification of the isolates was performed via phenotypic tests and species-specific multiplex Polymerase Chain Reaction (mPCR) method. PCR methods were used to phylotype E.coli isolates and to investigate virulence genes (bfpA, eaeA, LT, ST, Stx1, and Stx2). Of the total 600 E.coli isolates recovered in this study, 120 (20%), 269 (44.8%), 58 (9.7%), 19 (3.2%), 35 (5.8%), 56 (9.3%), 31 (5.2%), and 12 (2%) were identified as phylogroup A, B1, B2, C, D, E, F, and Escherichia clade I, respectively. While the virulence gene was detected in 149 (24.8%) E.coli isolates, no virulence gene was detected in 451 (75.2%) isolates. According to the analysis results, the most determined virulence gene was Stx1, while the least determined virulence gene was LT. In conclusion, in this study, when both the animal species and the number of E.coli isolates examined are considered, the data obtained are of great importance in epidemiological terms. However, the detection of virulence genes in 13.5% among phylogroup A, B1, and C isolates with commensal characteristics suggest that these isolates may show pathogenic characteristics with the virulence genes they contain.

Norepinephrine Effects on Uropathogenic Strains Virulence

The degree of virulence correlates with adhesion, biofilm formation, motility and the capacity to quickly colonize biological surfaces. The virulence of the bacteria that have colonized the urinary tract may be modified by substances dissolved in urine. One such substance is the norepinephrine (NE) hormone, which may be present in human urine, especially in times of stress and under changes in the activity of the renin-angiotensin-aldesterone system. In this work, we study the influence of NE on the biomass, biofilm formation, matrix production, adhesion, motility and metabolism of uropathogenic strains of E. coli and S. aureus. We used Congo red and gentian violet staining for detection of matrix and biomass formation, respectively. The optical density was measured by a multichannel spectrophotometer. The motility of bacterial cells was measured on semi-solid agar at 24 h and 48 h. The metabolic activity was analyzed by MTT assay. It was shown that the metabolic activity of E. coli was stimulated by NE, which led to the increasing synthesis of virulence factors such as biofilm production, adhesion, and motility. At the same time, NE did not activate the S. aureus strain’s metabolism and did not change its adhesion and motility. Thus, the virulence activity of uropathogenic E. coli may be modified by NE in urine.

Effect of the pH on the Antibacterial Potential and Cytotoxicity of Different Plasma-Activated Liquids

In this study, different plasma-activated liquids were evaluated for their antimicrobial effects against Escherichia coli, as well as for their cytotoxicity on mammalian cells. The PALs were prepared from distilled (DIS), deionized (DI), filtered (FIL), and tap (TAP) water. Additionally, 0.9% NaCl saline solution (SAL) was plasma-activated. These PALs were prepared using 5 L/min air gliding arc plasma jet for up to 60.0 min of exposure. Subsequently, the physicochemical properties, such as, the oxidation-reduction potential (ORP), the pH, the conductivity, and the total dissolved solids (TDS) were characterized by a water multiparameter. The PALs obtained showed a drastic decrease in the pH with increasing plasma exposure time, in contrast, the conductivity and TDS increased. In a general trend, the UV-vis analyses identified a higher production of the following reactive species of nitrogen and oxygen (RONS), HNO₂, H₂O₂, NO₃^-, and NO₂^-. Except for the plasma-activated filtered water (PAW-FIL), where there was a change in the position of NO₂^- and NO₃^- at some pHs, The higher production of HNO₂ and H₂O₂-reactive species was observed at a low pH. Finally, the standardized suspensions of Escherichia coli were exposed to PAL for up to 60.0 min. The plasma-activated deionized water (PAW-DI pH 2.5), plasma-activated distilled water (PAW-DIS pH 2.5 and 3), and plasma-activated tap water (PAW-TAP 3.5) showed the best antimicrobial effects at exposure times of 3.0, 10.0, and 30.0 min, respectively. The MTT analysis demonstrated low toxicity of all of the PAL samples. Our results indicate that the plasma activation of different liquids using the gliding arc system can generate specific physicochemical conditions that produce excellent antibacterial effects for E. coli with a safe application, thus bringing future contributions to creating new antimicrobial protocols.

An assessment of total coliforms and associated thresholds as water quality indicators using a large Ontario private drinking water well dataset

A spatiotemporally static total coliform (TC) concentration threshold of five colony-forming units (CFU) per 100 mL is used in Ontario to determine whether well water is of acceptable quality for drinking. The current study sought to assess the role of TC and associated thresholds as microbial water quality parameters as the authors hypothesized that, since static TC thresholds are not evidence-based, they may not be appropriate for all well water consumers. A dataset containing the microbial water quality information of 795,023 samples (including TC and Escherichia coli (E. coli) counts) collected from 253,136 private wells in Ontario between 2010 and 2017 was used. To accurately assess the relationship between E. coli and non-E. coli TC, "non-E. coli coliform" (NEC) counts were calculated from microbial water quality data and replaced TC throughout analyses. This study analysed NEC and E. coli detection rates to determine differences between the two, and NEC:E. coli concentration ratios to assess links, if any, between NEC and E. coli contamination. Study findings suggest that spatiotemporally static NEC thresholds are not appropriate because seasonal, spatial, and well-specific susceptibility factors are associated with distinct contamination trends. For example, NEC detection rates exhibited bimodality, with summer (29.4 %) and autumn (30.2 %) detection rates being significantly higher (p < 0.05) than winter (21.9 %) and spring (19.9 %). E. coli detection rates also varied seasonally, but peaked in summer rather than autumn. As such, it is recommended that these factors be considered during the development of private well water guidelines and that static thresholds be avoided. Furthermore, the authors propose that, because NEC:E. coli concentration ratios change in the context of the aforementioned factors, they may have a role in inferring groundwater contamination mechanisms, with high ratios being associated with generalized aquifer contamination mechanisms and low ratios with localized contamination mechanisms.

Characterization and complete genome analysis of a bacteriophage vB_EcoM_DE7 infecting donkey-derived Escherichia coli

A lytic bacteriophage vB_EcoM_DE7 (hereafter designated DE7) that could infect donkey-derived Escherichia coli was isolated. The bacteriophage was examined by transmission electron microscopy, and the result showed that DE7 belonged to the family Myoviridae. The microbiological characterization revealed that DE7 was stable over a broad range of pHs (3 ∼10) at 40-50 °C. The latent period was 10 min, and the burst size was 43 PFUs/infected cell. The whole-genome sequencing showed that DE7 was a dsDNA virus and had a genome of 86,130 bp. The genome contained 124 predicted open reading frames (ORFs), 35 of which had known functions, including DNA replication and modification, transcriptional regulation, structural and packaging proteins, and host cell lysis. Twenty tRNA genes were identified, but no genes associated with bacterial pathogenicity, lysogeny and drug resistance were identified. BLASTN analysis revealed that phage DE7 had a high sequence identity (96%) with Salmonella phage vB_SPuM_SP116, but it could not lyse any Salmonella strain tested in this study. DE7 was classified as a Felix O1-like virus based on its general characterization and genomic information. Since phage DE7 exhibited high efficacy in lysing E. coli and lacked genes associated with bacterial virulence, antimicrobial resistance and lysogeny, it could be potentially used to control foal diarrhoea caused by E. coli.

Improving intestinal absorption and antibacterial effect of florfenicol via nanocrystallisation technology

To study the effects of nanocrystallisation technology on the intestinal absorption properties and antibacterial activity of florfenicol (FF). The florfenicol nanocrystals (FF-NC) were prepared by wet grinding and spray drying. Additionally, changes in particle size, charge, morphology, and dissolution of FF-NC in the long-term stability were monitored by laser particle sizer, TEM, SEM, paddle method, and the structure of FF-NC powder was characterised by nuclear magnetic resonance (NMR) test. The antibacterial activity, intestinal absorption and intestinal histocompatibility of FF-NC were investigated by the stiletto, mini broth dilution susceptibility test, in situ single-pass intestinal perfusion (SPIP) and haematoxylin-eosin (H-E) staining. After 12 months of storage, the particle size and zeta potential of FF-NC were 280.43 ± 8.21 nm and -19.64 ± 3.45 mV, and the electron microscopy results showed that FF-NC were nearly circular with no adhesion between particles. In addition, the drug loading, encapsulation efficiency, and dissolution of FF-NC did not change significantly during storage. The inhibition zone of FF-NC against Escherichia coli and Staphylococcus aureus was 21.37 ± 1.70 mm and 25.17 ± 2.47 mm, respectively. Compared with the FF, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of FF-NC are reduced, and the absorption rate constant (K_a) and efficient permeability coefficient (P_eff) of FF-NC in the three intestinal segments were increased by 1.28, 0.25, and 9.10 times and 0.59, 0.17, and 6.0 times, respectively. The results of tissue sections showed that FF-NC had little damage to the small intestinal. Nanocrystallisation technology is an effective method to increase the intestinal absorption and antibacterial activity of FF.

Self-Assembly Anchored Cationic Copolymer Interfaces for Applying the Control of Counterion-Induced Bacteria Killing/Release Procedure

In recent years, daily hygiene and disease control issues have received increasing attention, especially the raging epidemics caused by the spread of deadly viruses. The construction of the interface of new polymer materials is focused on, which can provide a cyclic operation process for the killing and releasing of bacteria, and perform repeated regeneration, which is of great significance for the development of advanced medical biomaterials. In order to explore the basic physical phenomena of bacterial attachment and detachment on the polymer material interface by different amine groups, this study plans to synthesize four different butyl methacrylate (BMA)-based cationic copolymers with primary, ternary, and quaternary amine groups, and compare their effects on bactericidal efficiency. Since BMA can generate strong hydrophobic interactions with the benzene ring structure, this study used a polystyrene substrate to realize a self-assembled cationic copolymer interface for controlling the counterion-induced bacterial killing/release process. Furthermore, negatively charged ions are introduced to induce changes in the hydration capability of water molecules and control the subsequent bacterial detachment function. In this study, possible directions to answer and clarify the above concepts are proposed, and there is a basic reference principle that can lead to research work in macromolecular bioscience fields.

Synergistic cellulose-based nanocomposite packaging and cold plasma decontamination for extended saffron preservation

Sterilization of saffron packaging and maintaining the quality of saffron content are the main priorities in saffron preservation. Common modalities do not offer lasting saffron preservation and it is urgent to develop novel packaging approaches from renewable resources and prevent packaging waste. Here, simultaneous decontamination and quality maintenance of saffron is demonstrated, for the first time, through the synergistic application of nano-clay-loaded carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) nanocomposites (CNCs) and cold plasmas (CP). Compared to the separate uses of CP and CMC/PVA/nano clay, our results confirm the synergies between CP and CMC/PVA/nano clay cause complete inactivation of Escherichia coli bacteria, while not significantly affecting the concentrations of the essential saffron components (safranal, crocin, and picrocrocin). Overall, the CP-treated CMC/PVA/nano clay fosters saffron preservation, through contamination removal and quality maintenance of the food product. The synergistic application of CP and CMC/PVA/nano clay thus represents a promising strategy for packaging, sterilization, and preservation of high-value food products.

Dynamic multivariate analysis for pollution assessment and river habitat conservation in the Vietnamese La Buong watershed

Analysis of temporal patterns of high-dimensional time-series water quality data is essential for pollution management worldwide. This study has applied dynamic factor analysis (DFA) and cluster analysis (CA) to analyze time-series water quality data monitored at the five stations installed along the La Buong river in Southern Vietnam. Application of the DFA identified two types of temporal patterns, one of the run-off driven parameters (total suspended solid (TSS), turbidity, and iron) and the other of diffuse source pollution. The association of the variables like BOD₅ and COD at most stations to the run-off-driven parameters revealed their sharing of drivers. On the contrary, separating variables like phosphate (PO₄³) at the three upstream stations from the run-off patterns suggested their local point-source origin. The DFA-derived factors were later used in the time-point CA to explore the seasonality of water quality parameters and their pollution intensities compared to regulatory levels. The result suggested intensification in wet season of Fe, TSS, BOD₅, and COD concentrations at most sites, which are unobservable in run-off detached parameters like reactive nitrogen, phosphate (PO₄^3-), and E. coli. These findings generated robust insights to support water quality management for river habitat conservation.

Urban Birds as Antimicrobial Resistance Sentinels: White Storks Showed Higher Multidrug-Resistant Escherichia coli Levels Than Seagulls in Central Spain

The presence of AMR bacteria in the human-animal-environmental interface is a clear example of the One Health medicine. Several studies evidence the presence of resistant bacteria in wildlife, which can be used as a good indicator of anthropization level on the ecosystem. The fast increase in AMR in the environment in the last decade has been led by several factors as globalization and migration. Migratory birds can travel hundreds of kilometers and disseminate pathogens and AMR through different regions or even continents. The aim of this study was to compare the level of AMR in three migratory bird species: Ciconia ciconia, Larus fuscus and Chroicocephalus ridibundus. For this purpose, commensal Escherichia coli has been considered a useful indicator for AMR studies. After E. coli isolation from individual cloacal swabs, antimicrobial susceptibility tests were performed by the disk-diffusion method, including 17 different antibiotics. A total of 63.2% of gulls had resistant strains, in contrast to 31.6% of white storks. Out of all the resistant strains, 38.9% were considered multi-drug resistant (50% of white storks and 30% of seagulls). The antibiotic classes with the highest rate of AMR were betalactamics, quinolones and tetracyclines, the most commonly used antibiotic in human and veterinary medicine in Spain.

Antibiotic-Resistant Bacteria and Resistance Genes in Isolates from Ghanaian Drinking Water Sources

The control of infectious diseases is seriously threatened by the increase in the number of microorganisms resistant to antimicrobial agents. Antibiotic-resistant bacteria have also been identified in the water environment. A field study was performed sampling drinking water sources in seven districts of southern Ghana targeting boreholes, dams, hand-dug wells, and streams during baseflow conditions. Bacteria were isolated (N = 110) from a total of 67 water samples to investigate their antimicrobial susceptibility and to determine their carriage of select antibiotic resistance genes. Bacterial identification was performed using conventional selective media methods and the analytical profile index (API) method. Antibiotic susceptibility tests were carried out using the Kirby–Bauer method. Results indicated that all water sources tested were of poor quality based on the presence of fecal indicator organisms. The most commonly occurring bacterium isolated from water was Klebsiella spp. (N = 24, 21.8%), followed by E. coli (N = 23, 20.9%). Gram-negative bacteria isolates were most commonly resistant to cefuroxime (24.5%), while the Gram-positives were most commonly resistant to meropenem (21.3%). The highest rates of bacterial resistances to more than one antibiotic were observed in Klebsiella spp. (30.0%) followed by E. coli (27.8%). PCR was used to detect the presence of a select antibiotic resistance genes in the Gram-negative isolates. The presence of bla_NDM-1, sull, tet(O), and tet(W) were observed in isolates from all water sources. In contrast, ermF was not detected in any of the Gram-negative isolates from any water source. Most (28.7%) of the resistance genes were observed in E. coli isolates. Reducing microbial contamination of the various water sources is needed to protect public health and to ensure the sustainability of this resource. This further calls for education of the citizenry.

Flavonoids and Phenylethylamides Are Pivotal Factors Affecting the Antimicrobial Properties of Stingless Bee Honey

Despite the recent approval of stingless bee honey to the Argentine Food Code, there are still many gaps in information. Likely, the main reason for this is that multiple ecological and chemical factors influence their production and antimicrobial properties. This work combined metabolomic, microbiological, and physicochemical analyses to characterize the honey ofTetragonisca fiebrigifrom Northeastern Argentina. The antimicrobial activity tests showed that honey samples (n = 24) inhibited some Gram-positive and Gram-negative bacteria at different sensitivity levels. Furthermore, samples selected for their high bioactivity revealed crystallizations, a positive correlation with fungal growth, and the presence of flavonoids. The major polyphenols annotated by liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis and supported by metabolomic tools were quercetin 3,4'-dimethyl ether, pachypodol, jaceoside, irigenin trimethyl ether, corymboside, chrysoeriol 7-neohesperidoside, and corymboside. In contrast, samples missing antimicrobial activity did not crystallize, lacked flavonoids, and were enriched in phenylethylamides. Based on these findings, we discuss the significance of flavonoids and phenylethylamides on honey's antimicrobial activity and food quality and how they may indeed reflect essential parameters of the hive, such as microbial balance and eubiosis.

The antimicrobial effect of a novel peptide LL-1 on Escherichia coli by increasing membrane permeability

Background

The widespread use of antibiotics has led to the emergence of many drug-resistant strains; thus, the development of new antibacterial drugs is essential with antimicrobial peptides becoming the focus of research. This study assessed the antibacterial effect of a novel antimicrobial peptide, named LL-1 on Escherichia coli (E.coli) by determining the minimum inhibitory concentration (MIC) and the antibacterial curve. The interaction between LL-1 and E. coli DNA was then detected by nucleic acid gel electrophoresis. The effect of LL-1 on the E. coli cell membrane was assessed by detecting the leakage of β-galactosidase, nucleic acid and protein. The influence of LL-1 on the intracellular ATP of E. coli was analysed by determining the concentration of intracellular ATP. Finally, the bacteria and colonies of E. coli treated with LL-1 were observed using scanning and transmission electron microscopy.

Results

The results suggested that the MIC value was 3.125 µg/ml, and the antibacterial effect was dose-dependent. LL-1 dose-dependently combined with E. coli DNA. LL-1 resulted in the leakage of intracellular β-galactosidase, nucleic acid and protein, and decreased intracellular ATP concentrations of E. coli. Two MIC of LL-1 caused E. coli to shrink, resulting in a rough surface, plasmolysis, and bacterial adhesion.

Conclusion

This study indicated that LL-1 had a good bactericidal effect on E. coli by mainly increasing the permeability of the cell membrane, leading to leakage of the intracellular content. This will lay the foundation for an in-depth study on the antibacterial mechanism of LL-1 against E. coli and its clinical application.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-022-02621-y.

Carbapenemase- and Colistin Resistant Escherichia coli Strains from Children in China: High Genetic Diversity and First Report of bla NDM-5, bla CTX-M-65, bla OXA-10, bla TEM-1, and mcr-1.1 Genes Co-Occurrence in E. coli ST156

Background

The emergence of carbapenem and colistin co-resistant Escherichia coli poses a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in E. coli strains.

Methods

Antimicrobial susceptibility test was carried out by agar dilution methods and colistin resistance was confirmed by broth microdilution methods. Whole genome sequencing was carried out, and resistance genes, sequence types and virulence genes of carbapenems and colistin co-resistance E. coli isolates were analyzed.

Results

The results showed that among the 176 carbapenem-resistant Enterobacteriaceae strains, 5 multidrug resistant E. coli strains exhibiting coresistance to carbapenem and colistin. The main mechanism of 5 E. coli strains in this study was generating carbapenem. Four E. coli strains were mcr-positive, while one mcr-negative strain had a new MgrB mutation. The blaNDM-5, blaCTX-M-65, blaOXA-10, blaTEM-1 and mcr-1.1 genes were simultaneously detected in E. coli 20IR1127 strain belonging to ST156 lineage. Other antimicrobial resistance genes encoding aminoglycosides-, sulfonamide-, chloramphenicol-, tetracyclines- and macrolides resistance were also detected.

Conclusion

The main mechanisms of carbapenem and colistin resistance were encoded by bla_NDM and mcr1.1, meanwhile mgrB mutations also contribute to colistin resistance. To our knowledge, this study is the first to report of E. coli ST156 strain in which the bla_NDM-5, bla_CTX-M-65, bla_OXA-10, bla_TEM-1 and mcr1.1 genes coexist. In addition, there is also an E. coli ST457 strain, which carries bla_TEM-1, bla_NDM-9, bla_CTX-M-199 and is positive for mcr1.1 gene.

Can water composition and weather factors predict fecal indicator bacteria removal in retention ponds in variable weather conditions?

Retention ponds provide benefits including flood control, groundwater recharge, and water quality improvement, but changes in weather conditions could limit the effectiveness in improving microbial water quality metrics. The concentration of fecal indicator bacteria (FIB), which is used as regulatory standards to assess microbial water quality in retention ponds, could vary widely based on many factors including local weather and influent water chemistry and composition. In this critical review, we analyzed 7421 data collected from 19 retention ponds across North America listed in the International Stormwater BMP Database to examine if variable FIB removal in the field conditions can be predicted based on changes in these weather and water composition factors. Our analysis confirms that FIB removal in retention ponds is sensitive to weather conditions or seasons, but temperature and precipitation data may not describe the variable FIB removal. These weather conditions affect suspended solid and nutrient concentrations, which in turn could affect FIB concentration in the ponds. Removal of total suspended solids and total P only explained 5% and 12% of FIB removal data, respectively, and TN removal had no correlation with FIB removal. These results indicate that regression-based modeling with a single parameter as input has limited use to predict FIB removal due to the interactive nature of their effects on FIB removal. In contrast, machine learning algorithms such as the random forest method were able to predict 65% of the data. The overall analysis indicates that the machine learning model could play a critical role in predicting microbial water quality of surface waters under complex conditions where the variation of both water composition and weather conditions could deem regression-based modeling less effective.

Wheat supplement with buckwheat affect gut microbiome composition and circulate short-chain fatty acids

Buckwheat has beneficial effects on human intestinal health, which is often compounded with wheat to make food. Therefore, the effect of cereals mixture via in vitro fermentation on gut microbes and short-chain fatty acids (SCFAs) were investigated in this study. The mixture of wheat and tartary buckwheat (WT) produced more lactate and acetate, and the mixture of wheat and sweet buckwheat (WE) produced more propionate and butyrate. Compared with wheat (WA), the relative abundance of some beneficial bacteria significantly increased, such as Sutterella in WT and Faecalibacterium in WE. Cereals mixture also affected the expression of functional genes, involved in metabolic pathways and carbohydrate-active enzymes (CAZymes) that modulated SCFAs generation. This study provides new insights into the effects of sweet and tartary buckwheat on intestinal function, which is beneficial to applying both types of buckwheat in practical.

Proof of Concept for the Detection with Custom Printed Electrodes of Enterobactin as a Marker of Escherichia coli

The rapid and decentralized detection of bacteria from biomedical, environmental, and food samples has the capacity to improve the conventional protocols and to change a predictable outcome. Identifying new markers and analysis methods represents an attractive strategy for the indirect but simpler and safer detection of pathogens that could replace existing methods. Enterobactin (Ent), a siderophore produced by Escherichia coli or other Gram-negative bacteria, was studied on different electrode materials to reveal its electrochemical fingerprint—very useful information towards the detection of the bacteria based on this analyte. The molecule was successfully identified in culture media samples and a future goal is the development of a rapid antibiogram. The presence of Ent was also assessed in wastewater and treated water samples collected from the municipal sewage treatment plant, groundwater, and tap water. Moreover, a custom configuration printed on a medical glove was employed to detect the target in the presence of another bacterial marker, namely pyocyanin (PyoC), that being a metabolite specific of another pathogen bacterium, namely Pseudomonas aeruginosa. Such new mobile and wearable platforms offer considerable promise for rapid low-cost on-site screening of bacterial contamination.

Occurrence, Diversity and Anti-Fungal Resistance of Fungi in Sand of an Urban Beach in Slovenia—Environmental Monitoring with Possible Health Risk Implications

Beach safety regulation is based on faecal indicators in water, leaving out sand and fungi, whose presence in both matrices has often been reported. To study the abundance, diversity and possible fluctuations of mycobiota, fungi from sand and seawater were isolated from the Portorož beach (Slovenia) during a 1-year period. Sand analyses yielded 64 species of 43 genera, whereas seawater samples yielded 29 species of 18 genera. Environmental and taxonomical data of fungal communities were analysed using machine learning approaches. Changes in the air and water temperature, sunshine hours, humidity and precipitation, air pressure and wind speed appeared to affect mycobiota. The core genera Aphanoascus, Aspergillus, Fusarium, Bisifusarium, Penicillium, Talaromyces, and Rhizopus were found to compose a stable community within sand, although their presence and abundance fluctuated along with weather changes. Aspergillus spp. were the most abundant and thus tested against nine antimycotics using Sensititre Yeast One kit. Aspergillus niger and A. welwitschiae isolates were found to be resistant to amphotericin B. Additionally, four possible human pollution indicators were isolated during the bathing season, including Meyerozyma, which can be used in beach microbial regulation. Our findings provide the foundations for additional research on sand and seawater mycobiota and show the potential effect of global warming and extreme weather events on fungi in sand and sea.

Origin, fluxes, and reservoirs of Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa in aquatic ecosystems of a French floodplain

The release and spread of opportunistic pathogens - some of which are resistant to antibiotics - in the environment is a major public health challenge worldwide. In this study, we found evidence of the origin of such microorganisms and characterized their dispersal and survival in floodplain ecosystems to understand their fate in the environment. We determined the concentrations of Escherichia coli, extended-spectrum β-lactamases (ESBL)-producing E. coli, Klebsiella pneumoniae, ESBL-producing K. pneumoniae, and Pseudomonas aeruginosa in a floodplain of Eastern France using a culture-based method. Furthermore, we assessed the population structure of E. coli isolates by quadruplex PCR, their plasmid replicon content by PCR-based replicon typing, and the nature of their bla_ESBL genes by PCR and sequencing. The main aquatic ecosystems of the floodplain (river, tributaries, riverine wetlands, and groundwater) were sampled monthly over a one-year cycle. The majority of E. coli isolates retrieved in the studied floodplain were likely of human origin. Moreover, contamination of floodplain aquatic ecosystems by opportunistic pathogens mainly resulted from hydrological fluxes during high-flow periods, suggesting that dispersal and dilution predominated. During low-flow periods, E. coli may be able to survive for several months in isolated ecosystems in which it may find favourable conditions to thrive. The most nutrient-rich and isolated wetlands are consequently potential pathogen reservoirs. The production of ESBL was not a disadvantage for E. coli in low-anthropized floodplain ecosystems.