Enteropathogenic Escherichia Coli Research Articles

Antimicrobial Ionic Liquids: Ante-Mortem Mechanisms of Pathogenic EPEC and MRSA Examined by FTIR Spectroscopy.

Ionic liquids (ILs) have gained considerable attention due to their versatile and designable properties. ILs show great potential as antibacterial agents, but understanding the mechanism of attack on bacterial cells is essential to ensure the optimal design of IL-based biocides. The final aim is to achieve maximum efficacy while minimising toxicity and preventing resistance development in target organisms. In this study, we examined a dose-response analysis of ILs' antimicrobial activity against two pathogenic bacteria with different Gram types in terms of molecular responses on a cellular level using Fourier-transform infrared (FTIR) spectroscopy. In total, 18 ILs with different antimicrobial active motifs were evaluated on the Gram-negative enteropathogenic Escherichia coli (EPEC) and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA). The results showed that most ILs impact bacterial proteins with increasing concentration but have a minimal effect on cellular membranes. Dose-response spectral analysis revealed a distinct ante-mortem response against certain ILs for MRSA but not for EPEC. We found that at sub-lethal concentrations, MRSA actively changed their membrane composition to counteract the damaging effect induced by the ILs. This suggests a new adaptive mechanism of Gram-positive bacteria against ILs and demonstrates the need for a better understanding before using such substances as novel antimicrobials.

A dual-channel electrochemical biosensor enables concurrent detection of pathogens and antibiotic resistance

Diarrheagenic E. coli infections, commonly treated with β-lactam antibiotics, contribute to antibiotic resistance - a pressing public health concern. Rapid monitoring of pathogen antibiotic resistance is vital to combat antimicrobial spread. Current bacterial diagnosis methods identify pathogens or determine antibiotic resistance separately, necessitating multiple assays. There is an urgent need for tools that simultaneously identify infectious agents and their antibiotic resistance at the point of care (POC). We developed an integrated electrochemical chip-based biosensor for detecting enteropathogenic E. coli (EPEC), a major neonatal diarrheal pathogen, using an antibody against a virulence marker, termed EspB, and the β-lactam resistance marker, β-lactamase. A dual-channel microfabricated chip, bio-functionalized with a specific EspB monoclonal antibody, and nitrocefin, a β -lactamase substrate was utilized. The chip facilitated electrochemical impedance spectroscopy (EIS)-based detection of EspB antigen and EspB-expressing bacteria. For β-lactam resistance profiling, a second channel enabled differential-pulse voltammetric (DPV) measurement of hydrolyzed nitrocefin. EIS-based detection of EspB antigen was calibrated (LOD: 4.3 ng/mL ±1 and LOQ: 13.0 ng/mL ±3) as well as DPV-based detection of the antibiotic resistance marker, β-lactamase (LOD: 3.6 ng/mL ±1.65 and LOQ: 10 ng/mL ±4). The integrated EIS and DPV biosensor was employed for the simultaneous detection of EspB-expressing and β-lactamase-producing bacteria. The combined readout from both channels allowed the distinction between antibiotic-resistant and -sensitive pathogenic bacteria. The integrated electrochemical biosensor successfully achieved simultaneous, rapid detection of double positive EspB- and β-lactamase-expressing bacteria. Such distinction enabled by a portable device within a short assay time and a simplified sample preparation, may be highly valuable in mitigating the spread of AMR. This new diagnostic tool holds promise for the development of POC devices in clinical diagnosis.

Systemic Effects of a Phage Cocktail on Healthy Weaned Piglets.

Numerous studies have demonstrated that bacteriophages (phages) can effectively treat intestinal bacterial infections. However, research on the impact of phages on overall body health once they enter the intestine is limited. This study utilized weaned piglets as subjects to evaluate the systemic effects of an orally administered phage cocktail on their health. Twelve 21-day-old weaned piglets were divided into control (CON) and phage gavage (Phages) groups. The phage cocktail consisted of five lytic phages, targeting Salmonella enterica serovar Choleraesuis (S. choleraesuis), Enteropathogenic Escherichia coli (EPEC), and Shiga tox-in-producing Escherichia coli (STEC). The phages group received 10 mL of phage cocktail orally for 20 consecutive days. The results show that the phage gavage did not affect the piglets' growth performance, serum biochemical indices, or most organ indices, except for the pancreas. However, the impact on the intestine was complex. Firstly, although the pancreatic index decreased, it did not affect the secretion of digestive enzymes in the intestine. Secondly, phages increased the pH of jejunum chyme and relative weight of the ileum, and enhanced intestinal barrier function without affecting the morphology of the intestine. Thirdly, phages did not proliferate in the intestine, but altered the intestinal microbiota structure and increased concentrations of microbial metabolites isobutyric acid and isovaleric acid in the colonic chyme. In addition, phages impacted the immune status, significantly increasing serum IgA, IgG, and IgM, as well as serum and intestinal mucosal IFN-γ, IL-1β, IL-17, and TGF-β, and decreasing IL-4 and IL-10. They also activated toll-like receptors TLR-4 and TLR-9. Apart from an increase in basophil numbers, the counts of other immune cells in the blood did not change. This study indicates that the impact of phages on body health is complex, especially regarding immune status, warranting further attention. Short-term phage gavage did not have significant negative effects on health but could enhance intestinal barrier function.

Why put yourself on a pedestal? The pathogenic role of the A/E pedestal.

Certain Escherichia coli (E. coli) strains are attaching and effacing (A/E) lesion pathogens that primarily infect intestinal epithelial cells. They cause actin restructuring and polymerization within the host cell to create an actin-rich protrusion below the site of adherence, termed the pedestal. Although there is clarity on the pathways initiating pedestal formation, the underlying purpose(s) of the pedestal remains ambiguous. The conservation of pedestal-forming activity across multiple pathogens and redundancy in formation pathways indicate a pathogenic advantage. However, few decisive conclusions have been drawn, given that the results vary between model systems. Some research argues that the pedestal increases the colonization capability of the bacterium. These studies utilize A/E pathogens specifically deficient in pedestal formation to evaluate adhesion and intestinal colonization following infection. There have been many proposed mechanisms for the colonization benefit conferred by the pedestal. One suggested benefit is that the pedestal allows for direct cytosolic anchoring through incorporation of the established host cortical actin, causing a stable link between the pathogen and cell structure. The pedestal may confer enhanced motility, as enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) are better able to migrate on the surface of host cells and infect neighboring cells in the presence of the pedestal. Additionally, some research suggests that the pedestal improves effector delivery. This review will investigate the purpose of pedestal formation using evidence from recent literature and will critically evaluate the methodology and model systems. Most importantly, we will contextualize the proposed functions to reconcile potential synergistic effects.

Characteristics of Pathogenic Escherichia coli Associated with Diarrhea in Children under Five Years in Northwestern Ethiopia.

Diarrheagenic Escherichia coli (DEC) are the leading cause of infectious diarrhea and pose a significant global, regional, and national burden of disease. This study aimed to investigate the prevalence of six DEC pathotypes in children with diarrhea and determine their antibiotic resistance patterns. Samples from 107 diarrheagenic children were collected and processed for Escherichia coli (E. coli). Single-plex PCR was used to detect target virulence genes as well as characterize and categorize DEC pathotypes. Antibiotic resistance patterns were determined by the Kirby-Bauer disk diffusion method. E. coli was detected in 79 diarrheal stool samples, accounting for 73.8% of the samples collected. Additionally, 49.4% (39 out of 79) of the isolates harbored various typical virulence factors. Results revealed six pathotypes of virulence: enterotoxigenic E. coli (ETEC) (53.8%), enteropathogenic E. coli (EPEC) (12.8%), enteroaggregative E. coli (EAEC) (10.3%), Heteropathotypes (7.8%), Shiga toxin-producing E. coli (STEC), and enterohemorrhagic E. coli (EHEC) (7.7% each). The isolates exhibited high antibiotic resistance against trimethoprim/sulfamethoxazole (82.1%), amoxicillin (79.5%), ampicillin (74.4%), gentamicin (69.2%), and streptomycin (64.1%). An overall occurrence of 84.6% of multiple-drug resistance was observed in the isolates, with resistance ranging from three to four antibiotic classes. Our findings revealed a high level of pathogenic E. coli that were highly resistant to multiple categories of antibiotics among children in the Awi zone. These findings highlight the potential role of pathogenic E. coli in childhood diarrhea in tropical low-resource settings and underscore the need for continued research on the characteristics of pathogenic and antibiotic-resistant strains.

O26 Polysaccharides as Key Players in Enteropathogenic E. coli Immune Evasion and Vaccine Development.

Enteropathogenic Escherichia coli (EPEC) produce a capsule of polysaccharides identical to those composing the O-antigen polysaccharide of its LPS (lipopolysaccharide) molecules. In light of this, the impact of O26 polysaccharides on the immune evasion mechanisms of capsulated O26 EPEC compared to non-capsulated enterohemorrhagic Escherichia coli (EHEC) was investigated. Our findings reveal that there was no significant difference between the levels in EPEC and EHEC of rhamnose (2.8:2.5), a molecule considered to be a PAMP (Pathogen Associated Molecular Patterns). However, the levels of glucose (10:1.69), heptose (3.6:0.89) and N-acetylglucosamine (4.5:2.10), were significantly higher in EPEC than EHEC, respectively. It was also observed that the presence of a capsule in EPEC inhibited the deposition of C3b on the bacterial surface and protected the pathogen against lysis by the complement system. In addition, the presence of a capsule also protected EPEC against phagocytosis by macrophages. However, the immune evasion provided by the capsule was overcome in the presence of anti-O26 polysaccharide antibodies, and additionally, these antibodies were able to inhibit O26 EPEC adhesion to human epithelial cells. Finally, the results indicate that O26 polysaccharides can generate an effective humoral immune response, making them promising antigens for the development of a vaccine against capsulated O26 E. coli.

Characterization of diarrheagenic Escherichia coli from different cattle production systems in Brazil

Diarrheagenic E. coli (DEC) can cause severe diarrhea and is a public health concern worldwide. Cattle are an important reservoir for this group of pathogens, and once introduced into the abattoir environment, these microorganisms can contaminate consumer products. This study aimed to characterize the distribution of DEC [Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC)] from extensive and intensive cattle production systems in Brazil. Samples (n = 919) were collected from animal feces (n = 200), carcasses (n = 600), meat cuts (n = 90), employee feces (n = 9), and slaughterhouse water (n = 20). Virulence genes were detected by PCR in 10% of animal samples (94/919), with STEC (n = 81) as the higher prevalence, followed by EIEC (n = 8), and lastly EPEC (n = 5). Animals raised in an extensive system had a higher prevalence of STEC (average 48%, sd = 2.04) when compared to animals raised in an intensive system (23%, sd = 1.95) (Chi-square test, P < 0.001). From these animals, most STEC isolates only harbored stx2 (58%), and 7% were STEC LEE-positive isolates that were further identified as O157:H7. This study provides further evidence that cattle are potential sources of DEC, especially STEC, and that potentially pathogenic E. coli isolates are widely distributed in feces and carcasses during the slaughter process.

Colonization of the gut mucosa of colorectal cancer patients by pathogenic mucosa-associated Escherichia coli strains

Some strains of Escherichia coli are known to be involved in the pathogenesis of colorectal cancer (CRC). The aim of current study was to compare the general characteristics of the E. coli from CRC patients and healthy participants. A total of 96 biopsy samples from 48 CRC patients and 48 healthy participants, were studied. The clonality of the E. coli isolates was analyzed by Enterobacterial repetitive intergenic consensus-based PCR (ERIC-PCR) method. The strains were tested by PCR to determine the prevalence of different virulence factors. According to the results of ERIC-PCR analysis, (from the 860 E. coli isolates) 60 strains from CRC patients and 41 strains from healthy controls were identified. Interestingly, the majority of the strains of both groups were in the same cluster. Enteropathogenic E. coli (EPEC) was detected significantly more often in CRC patients (21.6 %) than in healthy participants (2.4 %) (p < 0.05). The Enteroaggregative E. coli (EAEC) was found in 18.33 % of the strains of CRC patients. However, other pathotypes were not found in the E. coli strains of both groups. Furthermore, all the studied genes encoding for virulence factors seemed to be more prevalent in the strains belonging to CRC patients. Among the virulence genes, the statistical difference regarding the frequency of fuyA, chuA, vat, papC, hlyA and cnf1 genes was found significant (p < 0.05). In conclusion, E. coli strains that carry extraintestinal pathogenic E. coli (ExPEC) and diarrheagenic E. coli (DEC) multiple virulence factors colonize the gut mucosa of CRC patients.

Enteric bacterial agents associated with diarrhea and their antimicrobial sensitivity profiles in children under 5 years from mukuru informal settlement, Nairobi, Kenya

BackgroundIn Kenya, diarrhoeal disease is the third leading cause of child mortality after malaria and pneumonia, accounting for nearly 100 deaths daily. We conducted a cross-sectional study in Mukuru informal settlements to determine the bacteria associated with diarrhea and their ASTs to provide data essential for implementing appropriate intervention measures.MethodsDiarrheagenic children (≤ 5 years) were purposively recruited from outpatient clinics of Municipal City Council, Mukuru kwa Reuben, Medical Missionaries of Mary, and Mama Lucy Kibaki Hospital, Nairobi. A total of 219 stool samples were collected between May 2021 and August 2021. Stool culture was done on MacConkey and Salmonella Shigella agar, while the recovered bacteria were identified using VITEK®2GNID and polymerase chain reaction (PCR) used for E. coli pathotyping. Antibiotic Susceptibility Testing was done using VITEK®2AST-GN83.ResultsAt least one bacterial organism was recovered from each of the 213 (97%) participants, with 115 (56%) participants having only one bacterial type isolated, 90 (43%) with two types of bacteria, and 2 (1%) with three types of bacteria recovered. The most predominant bacteria recovered was 85% (93/109) non-pathogenic E.coli and 15% (16/109)of pathogenic E.coli, with 2 (1%) were Enterohemorrhagic E.coli (EHEC), 6 (3%) were Enteroaggregative E.coli (EAEC), and 8 (4%) were Enteropathogenic E.coli (EPEC). Other potentially pathogenic bacteria included Enterobacter sp (27.8%), Klebsiella sp 33(11%), and Citrobacter sp 15(4.7%). Pathogenic isolates such as Salmonella 7 (2%), Proteus mirabilis 16 (6%), Providencia alcalifaciens 1 (0.3%), and Shigella 16 (4.7%) were detected. Isolates such as Pantoea spp 2(0.67%), Raoultella planticola 1(0.33%), and Kluyvera 6(2%) rarely reported but implicated with opportunistic diarrhoeal disease were also recovered. Ampicillin, cefazolin, and sulfamethoxazole-trimethoprim were the least effective antimicrobials at 64%, 57%, and 55% resistance, respectively, while meropenem (99%), amikacin (99%), tazobactam piperacillin (96%), and cefepime (95%) were the most effective. Overall, 33(21%) of all enterics recovered were multidrug-resistant.ConclusionThe study documented different bacteria potentially implicated with childhood diarrhea that were not limited to E. coli, Shigella, and Salmonella, as previously observed in Kenya. The strains were resistant to the commonly used antibiotics, thus narrowing the treatment options for diarrheal disease.

A Bird's-Eye View of the Pathophysiologic Role of the Human Urobiota in Health and Disease: Can We Modulate It?

For a long time, urine has been considered sterile in physiological conditions, thanks to the particular structure of the urinary tract and the production of uromodulin or Tamm-Horsfall protein (THP) by it. More recently, thanks to the development and use of new technologies, i.e., next-generation sequencing and expanded urine culture, the identification of a microbial community in the urine, the so-called urobiota, became possible. Major phyla detected in the urine are represented by Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Particularly, the female urobiota is largely represented by Lactobacillus spp., which are very active against urinary pathogenic Escherichia (E.) coli (UPEC) strains via the generation of lactic acid and hydrogen peroxide. Gut dysbiosis accounts for recurrent urinary tract infections (UTIs), so-called gut-bladder axis syndrome with the formation of intracellular bacterial communities in the course of acute cystitis. However, other chronic urinary tract infections are caused by bacterial strains of intestinal derivation. Monomicrobial and polymicrobial infections account for the outcome of acute and chronic UTIs, even including prostatitis and chronic pelvic pain. E. coli isolates have been shown to be more invasive and resistant to antibiotics. Probiotics, fecal microbial transplantation, phage therapy, antimicrobial peptides, and immune-mediated therapies, even including vaccines for the treatment of UTIs, will be described.

Type IV pili of Enterobacteriaceae species.

Type IV pili (T4Ps) are surface filaments widely distributed among bacteria and archaea. T4Ps are involved in many cellular functions and contribute to virulence in some species of bacteria. Due to the diversity of T4Ps, different properties have been observed for homologous proteins that make up T4Ps in various organisms. In this review, we highlight the essential components of T4Ps, their functions, and similarities to related systems. We emphasize the unique T4Ps of enteric pathogens within the Enterobacteriaceae family, which includes pathogenic strains of Escherichia coli and Salmonella. These include the bundle-forming pilus (BFP) of enteropathogenic E. coli (EPEC), longus (Lng) and colonization factor III (CFA/III) of enterotoxigenic E. coli (ETEC), T4P of Salmonella enterica serovar Typhi, Colonization Factor Citrobacter (CFC) of Citrobacter rodentium, T4P of Yersinia pseudotuberculosis, a ubiquitous T4P that was characterized in enterohemorrhagic E. coli (EHEC), and the R64 plasmid thin pilus. Finally, we highlight areas for further study.

P504 Prevalence of gastrointestinal infections in ulcerative colitis patients assessed with QIASTAT-DX® GASTROINTESTINAL PANEL 2

Abstract Background In inflammatory bowel disease (IBD), an acute clinical flare may be due to either disease exacerbation or an enteric infection. Thus, it is recommended to exclude infections before escalating IBD therapy. In this setting, conventional tests identify only a minimal proportion of infections (i.e. 10%). Whether nucleic acid multiplex tests can expand the range of detected pathogens and increase the overall prevalence is still a matter of debate. Methods We performed a single-center transversal prospective study at Fondazione IRCCS Policlinico Ca’ Granda. Stool samples from consecutive ulcerative colitis (UC) patients experiencing a disease flare and a group of patients in clinical remission were enrolled between February and October 2023 and tested with QIAstat-Dx Gastrointestinal Panel 2 (Qiagen GmbH, Hilden, Germany) for simultaneous qualitative detection and identification of nucleic acids from multiple viruses, bacteria, and parasites. Clinically active disease was defined as a Partial Mayo Score (PMS) of ≥2. Results Overall, 85 UC patients were enrolled. Demographics and clinical features are displayed in Table 1. Median age was 42 (18-79), 52% were males. The two most common treatment regimens were mesalamine (54%) and biologic/small molecule treatment (35%). 66 (78%) patients were clinically active, while 19 (22%) were in remission. In the active group, median bowel movements were 5 (3-15), 58 (88%) patients had loose stool, 32 (49%) reported abdominal pain, 40 (61%) urgency, 10 (15%) overnight symptoms, 6 (9%) fever. Median PMS was 5 (2-8). Median hemoglobin was 13.8 (8.2-16.4) g/dL, fecal calprotectin 508 (&amp;lt;5-4980) ug/g. Prevalence of gastrointestinal infections with QIAstat-Dx was 30 vs. 10% (p=0.13) in active vs. remission group, respectively. The most common infections were: C.Difficile infection (CDI) (4 cases), Cytomegalovirus (CMV) (4 cases) and enteropathogenic E.Coli (EPEC) (4 cases). Regarding viral and E. Coli infections, clinical remission (PMS &amp;lt;2) occurred spontaneously. As for CMV, Campylobacter spp., and CDI, all patients except one achieved remission following specific antimicrobial treatment. In one patient CMV infection led to hospital admission (circulating CMV DNA 35,395 IU/mL). The remaining patient did not receive specific antiviral therapy since sigmoidoscopy only detected isolated CMV+ cells, and remission was achieved with UC treatment escalation. Conclusion In UC patients experiencing a clinical flare, prevalence of gastrointestinal infections with QIAstat-Dx® Gastrointestinal Panel 2 is numerically higher than patients in remission. Further studies are needed to investigate whether increased detection could influence the clinical outcomes of IBD patients and time and costs for the healthcare system.

Phylogenetic Analysis of Attaching and Effacing E. coli Strains Isolated From Pet Birds in Iran

Background: Enteropathogenic E. coli (EPEC) and Shiga toxin-producing E. coli (STEC) are categorized as attaching and effacing E. coli (AEEC) due to their eae gene. One of the essential causes of diarrhea in humans is AEEC, which affects birds, too, thereby being considered a zoonotic pathogen. Objectives: Our study aimed to determine AEEC and evaluate its antibiotic resistance and phylogroups. Methods: A total of 200 fecal samples were collected from pet birds referred to the Veterinary Medicine Hospital, University of Tehran. PCR methods were used to detect AEEC using uspA, eae, bfpA, stx1, and stx2 gene-specific primers. The antimicrobial susceptibility of the recovered isolates was determined by the agar disk diffusion and MIC methods. Their phylogroups were analyzed based on Clermont phylotyping methods. Results: Of 200 samples, we isolated 26 (13%) E. coli strains, 9 harbor eae genes. None of the ease-positive samples possessed the bfpA gene, but 4 had stx2, and 5 had stx1 and stx2 genes. Phylogenetic analysis identified the phylogenetic groups of all AEEC isolated strains but 2 (duck and cockatiel). Detected phylogroups include four B2 and three D. Based on our results, 7 out of 9 AEEC isolated strains showed multi-drug resistance. Conclusion: The discovery of common phylogroups of AEEC in pet birds (a common companion animal in Iran with intimate contact with their owners, especially children) and humans, as well as their resistance to a wide range of antibiotics used in human medicine, verifies AEEC as a serious public health threat.

Bacteriological Examination of Deboned Turkey Meat in Gharbia Province

The present work was carried out to evaluate the microbiological quality of deboned turkey meat from the retail outlets in Gharbia province via determination of Aerobic bacterial count (ABC), coliforms count (CC) and isolation and identification of Salmonella, Staphylococcus aureus, Escherichia coli So, this study was carried out on a total of 100 sample of deboned turkey meat including Breast muscle and Thigh muscle of turkey samples (50 of each) that, were collected from local markets of Tanta University Garbia province –Egypt. All samples were transported without delay in a frozen state to the laboratory of animal health research institute – Tanta. Samples were subjected to bacteriological investigations. it was recorded that total bacterial counts showed a higher level of aerobic plate counts showed a higher level of total aerobic plate count observed in Thigh muscle (5.9×109) than the Breast muscle (2.5×106), While, the coliforms count showed a higher mean level observed in Thigh muscle (9.9×106) than the Breast muscle (2.8×105),The Salmonella counts showed a higher incidences observed in Breast muscle (18 %) than the Thigh muscle (12 %), The Escherichia coli counts showed the higher incidences of Escherichia coli count observed in thigh muscle (16 %) than the breast muscle (12 %). While, the higher level of Staphylococcus aureus counts observed in Thigh muscle (16 %) than the Breast muscle (12 %). While present results on the PCR results cleared that, the PCR for detection of Escherichia coli the Photograph of agarose gel electrophoresis of multiplex PCR Gave positive results for stx1 at (614 bp), stx2 at (779 bp) and for eaeA (890 bp) genes for characterization of Enteropathogenic Escherichiacoli. The higher incidences of Enteroppathogenic Escherichia Coli genes observed in stx1 (4 %) followed by stx2 (5 %) and eae A gene (1 %), While, the PCR results of Salmonella Spp cleared that, the agarose gel electrophoresis of multiplex PCR cleared that, the genes for salmonellae includes stn (260 bp), hilA (497 bp) and fimH (1008 bp) virulence genes for characterization of Salmonella species. The genes responsible for pathogenicity of salmonellae includes stn observed in (3 %) of examined samples, followed by hilA (4 %) and fimH 85 %) of examined samples. While, our results on the Staphylococcus aureus cleared that, the Photograph of agarose gel electrophoresis of multiplex PCR of genes responsible for pathogenicity of Escherichia coli includes sea (120 bp), seb (478 bp), sec (257 bp) and sed (317 bp) enterotoxin genes for characterization of S. aureus. The lanes of positive Staphylococcus aureus strains gave positive results for sea gene, seb gene, sec and sed genes. This study concluded that turkey meat possess a higher number of microorganisms like Salmonella, Staphylococcus aureus, Escherichia coli. Also, the presence of Salmonella, Staphylococcus aureus, Escherichia coli in turkey meat products may be due to unsanitary conditions, cross-contamination and post-processing contamination during handling, packaging, storage, distribution and selling on the other hand application of Hazard Analysis and Critical Control Point System (HACCP) which control the technological line of the production at all points from the farm to table to produce a safe product fit for human consumption.

Aksaray İli Buzağı İshallerinde Escherichia coli ve Escherichia coli Bakterisinin Son Üç Aylık Antibiyogram Sonuçları

Escherichia coli is a gram-negative, facultative anaerobic, motile, non-spore-forming rod-shaped bacterium belonging to the Enterobacteriaceae family. Pathogenic E. coli are divided into two groups: extraintestinal and intestinal. Intestinal Escherichia coli pathotypes: enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), Vero- or Shiga-toxin-producing E. coli (VTEC or STEC), enterohemorrhagic E. coli (EHEC), enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC) and diffusely adherent E. coli (DAEC). Extraintestinal pathogenic E. coli: These can be listed as septicemic pathogenic E. coli, uropathogenic E. coli, avian pathogenic E. coli, breast pathogenic E. coli and those that cause uterine infections, endometrial pathogenic E. coli. Enterotoxigenic Escherichia coli (ETEC) is the most common cause of neonatal diarrhea in calves and is a bacterial disease that colonizes the small intestine, produces enterotoxin, and occurs among calves during the neonatal period. The aim of this study is to determine the E.coli isolates that cause neonatal calf diarrhea in the Aksaray region between January, February and March 2021. To be used in the study, internal organ samples (liver, heart, lung and mesenteric lymph node) of neonatal calves that died due to diarrhea were taken from 20 different cattle farms in the Aksaray region. One calf that died in each farm was included in the sampling, and a total of 20 calves were sampled. E.coli was isolated in 12 (60%) of the internal organ samples covering these three months. According to the antibiogram results of the samples, 50% of the isolates were converted to Amoxicillin and Erythromycin, 33.3% to Tetracycline, 58.3% to Trimethoprim-sulfamethoxazole, 66.6% to Streptomycin, 75% to Flofenicol, Gentamicin and Enrofloxacin, % 83.3 of them were found to be sensitive to Cefloxacin and Cefloxacinium.

Modulating Liquid-Liquid Phase Separation of Nck Adaptor Protein against Enteropathogenic Escherichia coli Infection.

Signaling proteins often form biomolecular condensates through liquid-liquid phase separation (LLPS) during intracellular signal transduction. Modulating the LLPS property of intracellular protein condensates will redirect intracellular signals and provide a potential way to regulate cellular physiology. Phosphorylation of multiple tyrosine residues of the transmembrane receptor nephrin is known to drive the LLPS of the adaptor protein Nck and neuronal Wiskott-Aldrich Syndrome protein (N-WASP) and form the Nck signaling complex. Phosphorylation of the translocated intimin receptor (Tir) in the host cell may recruit this enteropathogenic Escherichia coli (EPEC) virulence factor to the Nck signaling complex and lead to the entry of EPEC into the intestine cell. In this work, we first identified a phosphotyrosine (pY)-containing peptide 3pY based on the sequence similarity of nephrin and Tir; 3pY promoted the LLPS of Nck and N-WASP, mimicking the role of phosphorylated nephrin. Next, we designed a covalent blocker of Nck, peptide p1 based on the selected pY peptides, which site-selectively reacted with the SH2 domain of Nck (Nck-SH2) at Lys331 through a proximity-induced reaction. The covalent reaction of p1 with Nck blocked the protein binding site of Nck-SH2 and disintegrated the 3pY/Nck/N-WASP condensates. In the presence of membrane-translocating peptide L17E, p1 entered Caco-2 cells in the cytosol, reduced the number of Nck puncta, and rendered Caco-2 cells resistant to EPEC infection. Site-selective covalent blockage of Nck thereby disintegrates intracellular Nck condensates, inhibits actin reorganization, and shuts down the entrance pathway of EPEC. This work showcases the promotion or inhibition of protein phase separation by synthetic peptides and the use of reactive peptides as LLPS disruptors and signal modulators.

Cross-talk between QseBC and PmrAB two-component systems is crucial for regulation of motility and colistin resistance in Enteropathogenic Escherichia coli.

The quorum sensing two-component system (TCS) QseBC has been linked to virulence, motility and metabolism regulation in multiple Gram-negative pathogens, including Enterohaemorrhagic Escherichia coli (EHEC), Uropathogenic E. coli (UPEC) and Salmonella enterica. In EHEC, the sensor histidine kinase (HK) QseC detects the quorum sensing signalling molecule AI-3 and also acts as an adrenergic sensor binding host epinephrine and norepinephrine. Downstream changes in gene expression are mediated by phosphorylation of its cognate response regulator (RR) QseB, and 'cross-talks' with non-cognate regulators KdpE and QseF to activate motility and virulence. In UPEC, cross-talk between QseBC and TCS PmrAB is crucial in the regulation and phosphorylation of QseB RR that acts as a repressor of multiple pathways, including motility. Here, we investigated QseBC regulation of motility in the atypical Enteropathogenic E. coli (EPEC) strain O125ac:H6, causative agent of persistent diarrhoea in children, and its possible cross-talk with the KdpDE and PmrAB TCS. We showed that in EPEC QseB acts as a repressor of genes involved in motility, virulence and stress response, and in absence of QseC HK, QseB is likely activated by the non-cognate PmrB HK, similarly to UPEC. We show that in absence of QseC, phosphorylated QseB activates its own expression, and is responsible for the low motility phenotypes seen in a QseC deletion mutant. Furthermore, we showed that KdpD HK regulates motility in an independent manner to QseBC and through a third unidentified party different to its own response regulator KdpE. We showed that PmrAB has a role in iron adaptation independent to QseBC. Finally, we showed that QseB is the responsible for activation of colistin and polymyxin B resistance genes while PmrA RR acts by preventing QseB activation of these resistance genes.

Silver nanoparticles synthesized by probiotic bacteria and antibacterial role in resistant bacteria

Many dangerous bacteria have become highly resistant to traditional antibiotics, which is a huge public health concern. This study investigated the use of silver nanoparticles biosynthesized in a culture filtrate of Lactobacillus acidophilus as antimicrobials. UV–visual spectrophotometry, Fourier-transform-infrared spectroscopy, X-ray power diffraction, and scanning electron microscopy have all validated the findings. The biosynthesized nanoparticles ranged in size from 33 to 90 nm. The cytotoxicity of the nanosilver generated was then investigated using nine 200 g BW rats separated into three groups. When compared to the control group, the treated rats showed little signs of toxicity; parameters of physiological function, including alanine transaminase, aspartate aminotransferase, albumin, creatinine, and urea were significantly different in treated and non-treated animals. Moreover, the antibacterial role of the generated silver nanoparticles was examined in multi-drug resistant (MDR) pathogenic bacteria, Proteus vulgaris, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae, revealing high antibacterial activity against the examined bacteria. For more demonstration of the effect of the nanosilver on transcription and gene regulation of treated and non-treated bacteria differential display droplet digital-PCR was used, and the results revealed that several genes were up- and down-regulated. Some genes were selected for DNA sequencing and according to the sequence analysis, these genes were mecA, beta-lactam, and unidentified protein genes, and these have been deposited in the GenBank Database with the following accession numbers: Staphylococcus MZ748472 and Klebsiella MZ748473. We conclude that silver nanoparticles biosynthesized by L. acidophilus are environmentally friendly and have antibacterial activities against MDR pathogenic bacteria.

Enteropathogenic E. coli infection co-elicits lysosomal exocytosis and lytic host cell death.

Enteropathogenic Escherichia coli (EPEC) infection is a significant cause of gastroenteritis, mainly in children. Therefore, studying the mechanisms of EPEC infection is an important research theme. EPEC modulates its host cell life by injecting via a type III secretion machinery cell death modulating effector proteins. For instance, while EspF and Map promote mitochondrial cell death, EspZ antagonizes cell death. We show that these effectors also control lysosomal exocytosis, i.e., the trafficking of lysosomes to the host cell plasma membrane. Interestingly, the capacity of these effectors to induce or protect against cell death correlates completely with their ability to induce LE, suggesting that the two processes are interconnected. Modulating host cell death is critical for establishing bacterial attachment to the host and subsequent dissemination. Therefore, exploring the modes of LE involvement in host cell death is crucial for elucidating the mechanisms underlying EPEC infection and disease.

Microbiological Analysis of Consecutively used Face Masks during the Covid-19 Pandemic

It is unanimously approved that face mask greatly supports reducing COVID-19 transmission. And it is still an important tool for dealing with the COVID-19 pandemic. However the utilization and handling of face masks are not so easy. Under this study, we set up an innovative way to investigate the microbial qual¬ity of the consecutively used face mask. People in Bangladesh use the same face mask several times, even for days to months. So the possibility of contaminating these masks with different microbes is so high. The frequency of using the same masks multiple times is higher in cloth masks than in surgical masks. The mi-crobial load was also significantly (P-value 0.0369) higher in cloth face masks than in surgical masks. The mean TVC of surgical masks was 9.92×103 CFU/inch2 and TCC was 5.38×103 CFU/inch2, while the mean TVC and TCC in cloth masks were 1.76×104 and 9.82×103 CFU/inch2, respectively. E. coli, Pseudomonas spp., and Proteus spp. bacterial isolates were assured by standard biochemical tests. Moreoever, enteropath¬ogenic Escherichia coli (EPEC) was confirmed by PCR targeting the bfpA gene (300bps). Bacterial isolates were resistant to different commercial antibiotics; E. coli resistant to Vancomycin (80%), Ampicillin (80%); Pseudomonas spp. resistant to Ampicillin (100%), Chloramphenicol (86.67%), and Vancomycin (80%); and Proteus spp. resistant to Miconazole (93.3%), Vancomycin (66.67%), respectively. Face masks protect against coronavirus, but pathogenic microbes contaminated masks may cause health hazards. So we should use face masks properly, keeping them sterile by using disinfectant or washing them properly for consec¬utive use.