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عضویت

جستجوی مقالات مرتبط با کلیدواژه "c. coli" در نشریات گروه "پزشکی"

  • Armin Karimi, Reza Akbari, Mehri Kouhkan*
    Objective

    The emergence of resistance in bacteria, and the existence of various types of infection and contamination in the hospital and society is the basis for research to find new antibacterial compounds.

    Materials and methods

    EthyleOctahydrospiro[indene-2,3'-pyrrolizidine]-1,3-diones-pyrrolizidine]-2'carboxylate (5) was synthesized during one-pot reaction of ninhydrin, proline and ethyl acrylate in ethanol solvent. The antibacterial effect of the synthesized derivative on the mentioned bacteria was investigated by surface culture methods in Mueller Hinton agar culture medium and microdilution, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for the synthesized derivative..

    Findings

    The analysis of the results showed that the MIC and MBC values of the newly synthesized compound against Staphylococcus aureus (S. aureus) bacteria were 1.56 and 3.12 μg/mlL, respectively. In addition, the MIC and MBC values of the synthetic compound against Escherichia coli (E. coli) were 0.39 μg/mlL and 0.78 μg/mlL, respectively. MIC and MBC values of standard gentamicin against E. coli bacteria were 3.2 and 6.4 μg/mL, respectively. MIC and MBC values of standard gentamicin against E. coli bacteria were 3.2 and 6.4 μg/mlL, respectively.

    Conclusion

    The derivative synthesized with indane and pyrrolizidine pharmacophores showed good antibacterial power against S. aureus, E. coli bacteria. Conclusion The antimicrobial test results revealed that the synthesized compound at an equivalent concentration exhibited a higher inhibitory impact on the Gram-negative E. coli bacteria than Gram-positive S. aureus. However, it demonstrated a more potent effect on the Gram-negative bacteria. The compound causes the immediate death of Gram-negative bacteria by destroying or disrupting the function of the outer membrane. This combination could be effective in treating infections caused by Gram-negative bacteria.

    Keywords: Chiral Azomethylene Ylide, 3 Dipolar Cyclization, Escherichia Coli, Indane
  • Fatemeh Omidi, Leila Fozouni*, Arash Nikyar, Mehr Ali Mahmood Janlou
    Background

    Cefiderocol is a siderophore cephalosporin with unique cell-penetrating abilities against multidrug-resistant (MDR) Gram-negative bacteria, especially carbapenem-resistant strains. This study aimed to evaluate the prevalence and susceptibility profiles of Cefiderocol on carbapenem-resistant uropathogenic Escherichia coli and Klebsiella pneumoniae isolates among hospitalized patients.

    Methods

    One hundred twenty-nine patients more than 72 h admitted to hospitals participated from Feb. 2021 to Dec. 2022. Urine samples were examined to identify uropathogenic K. pneumoniae and E. coli isolates based on microscopic morphology, cultural and biochemical methods. The carbapenemase production in the isolates was evaluated using modified Hodge tests and PCR. The MIC of Cefiderocol against carbapenemase-producing isolates was evaluated according to CLSI-2021 guidelines.

    Results

    According to phenotypic and genotypic tests, among forty-two E. coli isolates (71.19%) were carbapenemase positive, 38 isolates had the blaOXA gene (90.47%), and among twenty-four K. pneumoniae isolates 96% contained the blaKPC gene. In MIC determination 55.24% of carbapenem-resistant E. coli isolates were inhibited with ≤0.5 μg/ml of Cefiderocol, while only two strains (8.33%) of K. pneumoniae isolates showed resistance to the Cefiderocol (MIC90=2 μg/ml).

    Conclusion

    The present results demonstrate that the emergence of carbapenem-resistant uropathogenic bacteria poses a critical health threat to society. Based on the results, Cefiderocol demonstrated efficacy against carbapenem-resistant clinical isolates at low concentrations.

    Keywords: Cefiderocol, Carbapenemase, Escherichia Coli, Klebsiella Pneumonia
  • Seyed Abolfazl Hosseininasab, Fereshteh Saffari, Omid Tadjrobehkar, Hengameh Zandi, Bizhan Ahmadi, Asghar Khoshnood, Naser Niksefat, Mahtab Mehboodi
    Background

    Any alteration in gut microbiota may result in the colonization of certain pathobionts, leading to the development of colon diseases. Some strains of Escherichia coli are pathobionts that can contribute to the initiation or progression of colon diseases through the induction of pro-inflammatory pathways or the production of genotoxins.

    Objectives

    The present study was performed to investigate the association between certain E. coli pathobionts (cyclomodulin-positive and afa -C+ diffusely adherent E. coli ) and their characteristics with colon diseases.

    Methods

    Stool specimens were collected from patients referred to colonoscopy centers at two university-affiliated hospitals (Yazd and Kerman, Iran). A total of 67 patients voluntarily joined the study as the target group (21 cases of colorectal cancer and 46 cases of inflammatory bowel disease), along with 67 healthy individuals. Stool samples were screened for E. coli isolates using culture techniques. Cyclomodulin-encoding genes ( clbN , cnf , cdt , and cif ), as well as afa -C, were detected by PCR assay. Phylogrouping, virulence gene screening, antibiotic susceptibility evaluation, and biofilm formation assessment were also performed.

    Results

    In comparison with the control group, afa -C+ DAEC was significantly associated with CRC (n = 8, 38.1%, P = 0.001) and IBD (n = 8, 17.4%, P = 0.026). The presence of clb N (n = 4, 19%) and cnf (n = 4, 19%, P = 0.053) was relatively associated with CRC. Most of the isolates from the patient group (n = 16, 23.9%) belonged to phylogroup B2. Iron uptake-related genes were also significantly associated with isolates from patients. No significant association was found between antibiotic resistance and biofilm formation in any of the studied groups.

    Conclusions

    This study provides preliminary data about the involvement of certain important E. coli pathobionts in colon diseases. As afa -C+ DAEC was associated with the colon diseases studied, it appears that it may be proposed as a putative marker for screening procedures. However, a definitive conclusion requires more comprehensive investigations.

    Keywords: Gut Microbiota, Escherichia Coli, Cyclomodulin, Afa-C+ Daecinflammatory Bowel Disease, Colorectal Cancer
  • Saba Almasi Chegeni, Hossein Esmaeili, Peyman Lotfalizadeh
    Background

    Salivary abomasum disease (SAD) is a devastating disease causing significant mortality in Iranian goat and sheep herds. Understanding the causative agents is essential for developing effective preventive measures. This study investigated the potential role of Shiga toxin-producing Escherichia coli (STEC) in SAD pathogenesis.

    Methods

    We isolated E. coli from kid goats aged 3-30 days experiencing a sudden, acute illness characterized by gait imbalance, and death within 48 hours during the kidding season. Following isolation, we employed multiplex PCR to identify the presence of Shiga toxin genes (Stx1 and Stx2) associated with virulence in STEC strains.

    Results

    E. coli was isolated from 30 (75%) out of 40 animals. Notably, 7 (23.3%) isolates harbored the Stx2 gene, while only one isolate (3.3%) possessed the Stx1 gene.

    Conclusion

    These findings suggest a potential role for STEC, particularly strains carrying the Stx2 gene, in the development of SAD and multiple abomasal hemorrhages, in kid goats. The presence of Shiga toxin genes in a significant proportion of E. coli isolates highlights the importance of further research to elucidate their  contribution to SAD pathogenesis and inform the development of targeted interventions.

    Keywords: Escherichia Coli, Goat, Salivary Abomasumdisease, Shiga Toxin
  • Hadi Sedigh Ebrahim-Saraie, Mohammadesmaeil Amini, Meysam Hasannejad-Bibalan, Ervin Zadgari, Arash Bakhshi
    Background

    Biological contamination of foods is a serious problem for human health. Animal and animal products may be contaminated by these biological and chemical contaminants. One of the most important causes of foodborne illness in humans is Escherichia coli. Fluoroquinolones can be used as a suitable treatment for enteric infections in food-producing livestock. We aimed to evaluate the current status of resistance of E. coli strains isolated from animals and animal products to fluoroquinolone in Iran.

    Methods

     A systematic search was conducted using the Web of Science, PubMed, Embase, Google Scholar, and Scopus databases from 2000 to Oct 2020. Nineteen studies were selected based on the inclusion criteria and analysis by Comprehensive Meta-Analysis.

    Results

    Based on the data analysis, The rates of antibiotic resistance in animal strains were as follows: Flumequine (75.1%), Enrofloxacin (55.2%), Danofloxacin (48.1%), Ciprofloxacin (48.4%), and Norfloxacin (52.9%). Next, the rates of quinolone resistance among E. coli strains isolated from animal products were Norfloxacin (45.5%), Ciprofloxacin (44.5%), and Enrofloxacin (60.9%). Based on the funnel plots and Egger's test, there was no significant publication bias.

    Conclusion

    We finally concluded that antibiotic resistance in commensal E. coli is related to the overuse of antibiotics in livestock, especially fluoroquinolones.

    Keywords: Animal Products, Antimicrobial Resistance, Escherichia Coli, Fluoroquinolones, Iran
  • Sousan Akrami, Saeed Khoshnood, Maryam Koupaei, Effat Abbasi Montazeri, Hossein Meghdadi, Morteza Saki, Moloudsadat Motahar, Sara Masihzadeh, Sara Daneshfar, Marjan Abdi, Zahra Farshadzadeh
    Background

    Resistance to antibiotics and the ability to develop biofilms, two main virulence determinants of Escherichia coli , play a crucial role in the persistence of infections.

    Objectives

    The aim of this study was to evaluate aminoglycoside resistance and biofilm formation potential in E. coli isolates collected from hospitalized patients in the Southwest of Iran.

    Methods

    A total of 70 E. coli clinical isolates from different specimens were collected from Ahvaz teaching hospitals affiliated with Ahvaz Jundishapur University of Medical Sciences. All the isolates were identified as E. coli using conventional microbiological tests. Susceptibility to antibiotics was determined using the Kirby–Bauer disk diffusion method. Biofilm formation was assessed using the microtiter plate method. Finally, PCR was conducted to detect virulence gene determinants, including fimbrial genes, aminoglycoside modifying enzymes (AMEs), and 16S rRNA methylase (RMTase) genes.

    Results

    Among aminoglycoside antibiotics, E. coli isolates showed the highest and lowest resistance rates to tobramycin (TOB; 51.4%) and gentamicin (GEN; 24.2%), respectively. Simultaneous resistance to GEN, amikacin, and TOB was observed in 28.5% of the isolates, representing the most common antibiotic resistance pattern. The prevalence of strong biofilm producers was higher in the extensively drug-resistant (XDR) phenotype group compared to the multiple drug-resistant (MDR) group (76.1% vs. 23.8%). Among the 36 isolates resistant to at least one of the aminoglycoside antibiotics, 36.1% had AME-related genes, either alone or in various combinations. Most isolates harboring AME genes were also positive for the presence of biofilm-related genes, including ecpA and fimA .

    Conclusions

    The most frequent AME-related genes were ant(2”) -Ia and aph(3’)-Ia , followed by aac(3’)-IIa . The findings of the present study provide probable evidence that GEN is an effective aminoglycoside against biofilm-producing and antibiotic-resistant E. coli isolates.

    Keywords: Escherichia Coli, Biofilm, Aminoglycoside-Modifying Enzymes, Antibiotic Resistance, Iran
  • Zeinab Rohani, Hossein Sazegar, Ebrahim Rahimi
    Background

    Long noncoding RNAs (lncRNAs) play significant roles in various cellular processes, and alterations in their expression levels can contribute to the pathogenesis of colorectal cancer (CRC).

    Objectives

    This study aims to identify lncRNAs highly associated with poor prognosis in CRC and determine those that exhibit significant expression changes under the influence of Escherichia coli K-12.

    Methods

    Potentially susceptible lncRNAs to expression modulation in the presence of E. coli K-12 were identified by analyzing GSE50040 datasets. Data from the cancer genome Atlas (TCGA) were utilized to assess E. coli K-12-affected lncRNAs with the most significant impact on CRC pathogenesis. The association between the candidate lncRNA and patient prognosis was investigated using clinical data. The co-expression network was employed to identify pathways related to the identified lncRNA via the MsigDB database. To validate the in silico findings, CRC and adjacent normal samples were examined using the RT-qPCR method.

    Results

    Cox regression analysis demonstrated that MIR17HG is a strong biomarker associated with poor prognosis in CRC patients. Increased expression of MIR17HG in cancer samples was correlated with key pathways involving cell proliferation, anti-apoptosis, and metastasis. RT-qPCR results showed that the expression level of MIR17HG in CRC samples was significantly higher than in normal samples. Further analysis revealed that MIR17HG expression is susceptible to suppression by E. coli K-12.

    Conclusions

    High expression of MIR17HG in cancer samples is associated with an increased probability of mortality in CRC patients. Our study highlights the potential of E. coli K-12 to reduce CRC malignancy by downregulating MIR17HG expression.

    Keywords: Lncrna, Prognosis, Biomarker, Escherichia Coli, Colorectal Cancer
  • Abhishek Mehta*, Dharmendra Singh Gurjar, Vijay Singh Rajak
    Background & Aims

    Urinary tract infections (UTI) are a leading cause of bacterial infections in humans.The widespread use of antibiotics has resulted in the emergence of antibiotic-resistant microorganisms. Hence, the current study was conducted to investigate the antibiotic sensitivity pattern of uropathogens in UTI.

    Materials & Methods

    A total of 642 urine samples were collected from suspected UTI patients and tested microbiologically. Antimicrobial susceptibility tests were performed for the isolated pathogens using the Kirby- Bauer disk diffusion method.

    Results

    Out of 642 urine samples, 308 (48%) were found to exhibit significant bacteriuria. Females had a higher rate of UTI (68%) than males (32%), with a higher prevalence in the middle-aged group, while males reported a higher prevalence in the elderly group, which was statistically significant. The most common organism was Escherichia coli (57.2%), followed by Klebsiella pneumoniae (26.3%), Pseudomonas aeruginosa (8.4%), Proteus spp. (3.6%), Enterococcus spp. (2.6%), and Staphylococcus aureus (1.9%). UTI were more common in middle-aged female patients (31 to 45 years), while in males, high prevalence was seen in older patients (>45 years). Meropenem, Gentamicin, Nitrofurantoin, and Co-Trimoxazole were amongst the most sensitive drugs against E.coli and K.pneumoniae.

    Conclusion

    Due to the irrational and injudicious use of antibiotics, commonly isolated uropathogens have a changing resistance pattern, resulting in reduced treatment effectiveness. This could be overcome by routine antimicrobial resistance surveillance, antimicrobial stewardship measures, and culture-guided therapy.

    Keywords: Antibiotic Susceptibility Pattern, Antimicrobial Resistance, Bacteriuria, Escherichia Coli, Urinary Tract Infection, Uropathogens
  • Shiva Rafati, Reyhaneh Tavousian, Ali Davati, Azadeh Afshin, Mohammadmehdi Attarpour Yazdi, Masood Soltanipur, Sina Shahshenas
    Background

    Childhood urinary tract infections (UTIs) are among the most prevalent diseases. In recent years, the overuse of common antibiotics has increased antibiotic resistance among urinary tract pathogens worldwide, with changes in the pattern of microbial resistance varying by geographical area and time.

    Objectives

    This study aims to investigate the pattern of microbial resistance of UTI pathogens in pediatric patients.

    Methods

    In this cross-sectional study, children aged < 13 years with UTI and positive urine cultures, who were admitted to Bahrami Hospital in Tehran, Iran, between 2015 and 2019, were evaluated. The pathogens' frequency, their antimicrobial resistance, and clinical and demographic information were extracted from the patients' files. Statistical relationships between clinical and demographic data and antibiotic resistance were analyzed using appropriate statistical tests.

    Results

    The files of 202 patients were evaluated. The majority of patients were female (79.2%). UTI was more common among the 12 - 60 months age group (36.3%) in females and the 1 - 12 months age group (50%) in males. The most common UTI pathogen was Escherichia coli (85.1%). The lowest rates of microbial resistance were related to Meropenem (0% resistance), Gentamicin (9.2%), and Amikacin (10.8%). Conversely, the highest resistance rates were observed for Cotrimoxazole (74.6%), Ampicillin (74.5%), and Cephalothin (64.9%).

    Conclusions

    UTI is more common in females aged 1 to 60 months. E. coli is the most common cause of UTI. Microbial resistance to antibiotics used for empirical treatment, such as ceftriaxone, is high and changes over time. It is recommended to use alternative antibiotics and avoid the inappropriate administration of antibiotics.

    Keywords: UTI, Pediatric, Resistance, Antibiotic, E. Coli
  • پریسا نوربخش، تقی صالحی زهرایی، سامان حسینخانی، جلیل مهرزاد*
    مقدمه

    مقاومت آنتی بیوتیکی به طور نگران کننده ای در حال افزایش است. اخیرا استفاده از پست بیوتیک ها علیه عوامل میکروبی پاتوژن برای فرموله کردن داروهای جدید همراه یا جایگزین آنتی بیوتیک ها مد نظر قرار گرفته است. به این ترتیب، پژوهش حاضر با هدف بررسی اثرات بازدارندگی پست بیوتیک لاکتوباسیلوس پاراکازئی بر رایج ترین پاتوژن های استافیلوکوکی و کلی فرمی انجام گرفت.

    روش کار

    سویه استاندارد باکتری لاکتوباسیلوس پاراکازئی در محیط MRS کشت داده شد. سپس اثر مهاری پست بیوتیک های بدست آمده و کنترلهای منفی (بدون تیمار) و مثبت (تیمار با آنتی بیوتیک بر دو باکتری پاتوژن استافیلوکوک اورئوس و اشرشیا کلی توسط تست MIC به روش رقیق سازی در پلیت های 96 چاهکی ارزیابی شد. نتایج در طول موج 630 نانومتر خوانش شد.

    یافته ها

    اثر همه پست بیوتیک ها به جز گروه C (مایع رویی بدست آمده دارای تیمار سونیکاسیون- شوک حرارتی) نسبت به کنترل منفی (بدون تیمار) معنادار بود (p<0.05). پست بیوتیک گروهD)مایع رویی بدست آمده دارای تیمار سونیکاسیون - شوک حرارتی- فریز و دفریز) بطور چشمگیری مثل کنترل مثبت (تیمار با آنتی بیوتیک مروپنم) رشد استافیلوکوکوس اورئوس (P=0.0006) و اشریشیا کلی (P=0.0003) مهار کرد. همچنین گروه های مختلف پست بیوتیک تاثیر تقریبا مشابه غیر معنا داری بر پاتوژنهای استافیلوکوکی در مقایسه با کلی فرمی داشتند.

    نتیجه گیری

    یافته های این پژوهش بر پتانسیل ضد باکتریای پست بیوتیک های لاکتوباسیلوس پاراکازئی علیه پاتوژن های رایج تاکید می کند، و آنها را برای توسعه و کاربردهای بیشتر زیست پزشکی و دارویی نامزدهای امیدوارکننده ای مینماید.

    کلید واژگان: استافیلوکوک, کلی فرم, پستبیوتیک, لاکتوباسیلوسف, آنتی بیوتیک
    Parisa Nourbakhsh, Taghi Zahraei Salehi, Saman Hosseinkhani, Jalil Mehrzad *
    Introduction

    Antibiotic resistance is regrettably increasing. Recently, application of postbiotics against various microbial pathogens can safely be considered to formulate/substitute with antibiotics. As such, we aimed to investigate the inhibitory effect of Lactobacillus Paracasei against the most common Staphylococcal and coliform pathogens.

    Methods

    The standard strain of Lactobacillus (L.) paracasei was cultivated in MRS medium. Then, the inhibitory effects of different obtained postbiotics along with negative-and-positive controls on two pathogenic bacteria, Staphylococcus (S.) aureus and Escherichia (E.) coli, was evaluated by the MIC test using the microdilution method on 96-well plates. The results were determined at 630 nm.

    Findings

    The effect of all isolated postbiotics except group C (supernatant obtained with sonication-heat shock treatment) compared to the negative controls (without treatment) was statistically significant (p<0.05). Also, the postbiotic group D (supernatant obtained with sonication-thermal shock-freeze treatment) had as remarkably inhibitory effect as positive control (with meropenem treatment) on S. aureus (p=0.0006) and E. coli (P=0.0003). Also, different groups of postbiotics had almost similarly non-significant effect on S. aureus versus E. coli.

    Conclusion

    Results of this study emphasize the antibacterial potential of Lactobacillus paracasei postbiotics against common pathogens, and these postbiotics can be considered as one of the promising candidates for development and further biomedical and pharmaceutical applications.

    Keywords: Staphylococcus Aureus, Escherichia Coli, Postbiotic, Lactobacillus Paracasei, Antibiotic Resistance
  • Sayed Nassereddin Mostafavi Esfahani, Soodabeh Rostami, Shekoufe Poorshariat
    Background

    Escherichia coli is an important cause of urinary tract, bloodstream, and surgical site infections.

    Objectives

    We investigated the organism's antibiotic susceptibility in hospitalized patients under different clinical conditions.

    Methods

    This prospective study was conducted in three referral hospitals located in Isfahan, Iran. Different clinical samples were tested using standard routine microbiological methods to identify E. coli strains and determine their antibiotic susceptibility patterns by the disk diffusion method according to CLSI recommendations. After conducting a clinical investigation, contaminated samples were excluded, and the hospital or community source and infection site were identified. Data on antibiotic susceptibility testing were extracted using WHONET software. Data analysis was then conducted using SPSS Statistics version 18.0.

    Results

    Of 1248 E. coli isolates, 71.9% were from urine, 15.1% from blood, and 7.8% from skin and soft tissue samples. High susceptibility was observed to Imipenem (98%), Meropenem (98.0%), and Amikacin (94.6%); intermediate sensitivity to Gentamicin (68.6%) and Cefepime (51.9%); and low susceptibility to Ceftazidime (46.8%), Ceftriaxone (41.3%), Ciprofloxacin (39.5%), Cefotaxime (39.3%), and Trimethoprim-sulfamethoxazole (32.4%).

    Conclusions

    Antibiotics, including Imipenem, Meropenem, or Amikacin, would be beneficial in the empiric therapy of severe infections where E. coli is the main cause.

    Keywords: E. Coli, Microbial Sensitivity Tests, Drug Resistance, Microbial, Iran
  • Y.Y. Varela-Rangel, L. Guillén, C. Cuadra-Sánchez, M. Araque*
    Background

    Fresh pasta filata cheese is considered as one of the most important foods in the Venezuelan diet. It is typically produced by small-scale producers using raw milk. The objective of this research was to molecularly characterize the pathogenic potential of Escherichia coli strains isolated from pasta filata cheese manufactured and marketed in Venezuela.

    Methodology

    In the period between January and March of 2019, a total of 36 strains of E. coli were isolated from a variety of pasta filata cheeses including 17 samples of mozzarella, 16 of telita, and 3 of guayanés. These strains were isolated according to the Venezuelan Commission of Industrial Standards (COVENIN) and identified by conventional methods (biochemical and phenotypic tests). Antimicrobial susceptibility was determined using the disk diffusion technique. Phylogenetic grouping and detection of virulence genes were performed by Polymerase Chain Reaction amplification. Diversity and genetic relationships were determined by Rep-PCR.

    Results

    All strains were susceptible to the tested antibiotics. Phylogroup A (n=19) was the most frequent (52.8%), followed by groups D (n=11; 30.6%), and B1 (n=2; 5.6%). The majority of isolates carried at least two virulence genes, one coding for adhesion mechanisms (fimH) and the other for iron uptake (fyuA). Only one strain of phylogroup A presented a profile consisting of four virulence genes (fimH, fyuA, kpsMT II, and papAH). Four strains that could not be classified according to Clermont's scheme carried resistance genes as well. A heterogeneous population structure was observed by Rep-PCR of the strains.

    Conclusion

    Results support the hypothesis that the E. coli strains isolated from the three types of pasta filata cheeses manufactured and marketed in Venezuela have identical characteristics and virulence factors to Extraintestinal Pathogenic E. coli strains observed in animals and humans, posing a potential health risk. Therefore, it is essential to improve hygienic and sanitary controls at all stages of cheese production and to implement measures for epidemiological surveillance of potentially pathogenic bacterial strains present in Venezuelan, artisanal pasta filata cheeses.

    Keywords: Escherichia Coli, Food Safety, Cheese, Virulence, Genetic Variation
  • H. Seki*
    Background

    Implementing Hazard Analysis and Critical Control Point (HACCP) management across the supply chain is promoted globally to ensure the safety of marine food products due to their rapid quality deterioration. However, many seafood retail stores deviate from adopting these practices. Therefore, in this study, we aimed to create a flowchart based on HACCP and validate it in retail stores.

    Methods

    Chub mackerel (Scomber japonicus), scallops (Patinopecten yessoensis), and whiteleg shrimp (Litopenaeus vannamei) specimens were purchased from a supermarket from August to December 2020. The handling information of these products from receipt to sales was obtained to prepare an HACCP plan for retail stores. Groups adhering to and deviating from flowchart conditions were categorized as Critical Control Point (CCP)-compliant and CCP-deviant, respectively. Four samples of each product for each condition were analyzed. Bacterial viability was evaluated using the flat agar culture method. Escherichia coli and Vibrio parahaemolyticus were detected using the Brilliant Green-Lactose-Bile and material point methods, respectively. Product freshness was assessed by determining K-values using High-Performance Liquid Chromatography. Results were compared using Student’s t-test.

    Results

    At elevated storage temperatures, bacterial growth rates were higher in chub mackerel and whiteleg shrimp than those in scallops. E. coli was not detected in any sample, whereas V. parahaemolyticus was detected in scallops and whiteleg shrimp but not in chub mackerel. CCP-deviant refrigerated scallops had increased V. parahaemolyticus counts; however, it did not differ between the frozen scallop and whiteleg shrimp. K-values increased more rapidly in CCP-deviant chub mackerel, whiteleg shrimp, and refrigerated scallops, but not in frozen scallops. Inadequate temperature control during display and sale markedly deteriorated the quality of marine products.

    Conclusion

    Setting CCPs for marine food product display and sale while controlling temperature can preserve product quality. The flowchart created in this study can be broadly used for marine retail stores.

    Keywords: Microbial Viability, Escherichia Coli, Seafood, Hazard Analysis, Critical Control Points, Food Safety
  • هادی نیک نژاد، نیما کلوانی، مهدی سیدی راد، علیرضا اعلا، رضا سعیدی، مهرنوش ابطحی، فتح الله غلامی بروجنی*
    زمینه و هدف

    نگرانی هایی در مورد آلودگی میکروبی در شهرهای ساحلی شمال کشور بویژه شهرهای استان مازندران وجود دارد که می تواند خطراتی را برای سلامتی شناگران و گردشگران به همراه داشته باشد. مطالعه حاضر با هدف بررسی کمی میزان خطر بروز بیماری های گوارشی ناشی از مواجهه با باکتری های اشرشیا کلی (E.coli) و انتروکوکوس در حین فعالیت های تفریحی در سواحل فریدونکنار انجام شد.

    روش بررسی

    در مطالعه توصیفی مقطعی حاضر، به منظور بررسی وضعیت میکروبی شناگاه های ساحلی فریدونکنار 66 نمونه بصورت لحظه ای در فصل تابستان برداشت شد. روش شبیه سازی مونت کارلو برای محاسبه خطر عفونت روزانه و سالانه مورد استفاده قرار گرفت.

    یافته ها

    نتایج نشان داد که در آب های تفریحی این سواحل، خطر ابتلا به انتروکوکوس بیشتر از E.coli بود. میانگین خطر عفونت سالانه E.coli در بزرگسالان و کودکان به ترتیب 0/41 و 0/69 بود. همچنین خطر عفونت سالانه انتروکوکوس برای کودکان و بزرگسالان 1 و 0/99 بود که بالاتر از سطح توصیه شده توسط WHO و EPA بود. نتایج نشان داد که خطر ابتلا به عفونت برای کودکان بیشتر از بزرگسالان بوده است.

    نتیجه گیری

    تخلیه کنترل نشده فاضلاب های شهری و صنعتی به دریاها و رودخانه ها نقش اساسی در آلودگی میکروبی سواحل دارد. با اجرای استراتژی های مدیریت زیست محیطی و تفریحی موثر، می توان خطرات بهداشت عمومی را در سواحل تفریحی به حداقل رساند و در عین حال زیبایی طبیعی این فضاهای عمومی مهم را نیز حفظ کرد.

    کلید واژگان: شناگاه های ساحلی, انتروکوکوس, اشرشیاکلی, روش مونت کارلو
    Hadi Niknejad, Nima Kalvani, Mehdi Seyedirad, Alireza Ala, Reza Saeedi, Mehrnoosh Abtahi, Fathollah Gholami-Borujeni*
    Background and Objective

    There have been concerns about microbial contamination along the coastal cities in the north of the country, particularly in cities of Mazandaran province, which could pose health risks for swimmers and tourists. The present study aimed to quantitatively assess the risk of gastrointestinal diseases resulting from exposure to E. coli and enterococci bacteria during recreational activities on the beaches of Fereydunkanar.

    Materials and Methods

    In this cross-sectional descriptive study, 66 grab samples collected during the summer were analyzed to investigate microbial contamination in the recreational beach waters of Fereydunkanar.The Monte Carlo simulation method was used to calculate both daily and annual infection risks.

    Results

    The findings demonstrated that transmission of enterococci was more likely than that of E. coli in the swimming areas of these beaches. The average annual infection risk for E. coli was 0.41 for adults and 0.69 for children . Additionally, the annual risk of enterococci infection was 1 for adults and 0.99 children and, which exceeds the range advised by the WHO and EPA. These findings indicate that children have a higher infection risk compared to adults.

    Conclusion

    Unrestricted discharge of municipal and industrial wastewater effluents into sea and rivers can contribute to the presence of harmful microbes in beaches. By implementing effective environmental and recreational management strategies, it is possible to minimize the risk of public health hazards at recreational beaches while also preserving the natural beauty of these important public spaces.

    Keywords: Swimming Beaches, Enterococcus, Escherichia Coli, Monte Carlo Method
  • Bahman Mirzaei*
    Background & Objective

    Extended-spectrum beta-lactamases (ESBLs) are enzymes in bacteria that resist many antibiotics. Detection of ESBLs production is important as it's a marker of colonization and potential transfer to other patients. We studied the antibiotic susceptibility, biofilm formation capacity, and prevalence of ESBLs of opportunistic bacteria including K. pneumoniae and E. coli. The isolates capable of biofilm formation were analyzed among 100 E. coli and 104 K. pneumoniae isolates.

    Materials & Methods

    This process involved collecting and identifying bacterial samples, testing antibiotic susceptibility, detecting ESBLs phenotypes, and multidrug-resistance (MDR) isolates, assessing biofilm formation capability, and evaluating results through statistical analysis.

    Results

    The susceptibility tests for discs were performed following the guidelines outlined by the Clinical Laboratory Standards Institute in 2023 (CLSI). K. pneumoniae exhibits inherent resistance to ampicillin, while 80 (80%) strains of E. coli have been reported to be resistant to ampicillin. Additionally, 50 K. pneumoniae isolates and 41 E. coli isolates were found capable of forming a biofilm. Seven of E. coli (17.07%), and seven of K. pneumoniae (14%) isolates could form a mighty biofilm. It was observed that the strongest resistance in the isolates that formed strong biofilm was related to tetracycline with 5 (7.2%) resistance in K. pneumonia and 7 (7%) resistance in E. coli. Furthermore, 47 (47%) of E. coli, and 21 (20.2%) of K. pneumoniae isolates were classified as ESBLs producers, and 52 (50%) K. pneumoniae and 72 (72%) E. coli isolates were classified as MDR.

    Conclusion

    Considering the role of biofilm in the transfer of genes, appropriate health policies, and the correct administration of effective antibiotics can help in prevention.

    Keywords: Escherichia Coli, Klebsiella Pneumoniae, Antibiotic-Resistant, Biofilm, Esbls, MDR
  • Hossein Golchinpour, Alireza Momeni, Mohammadhadi Meshkatalsadat *

    The green synthesis of metal oxide nanoparticles using plant extracts can effectively replace traditional chemical synthesis methods. In present paper, we describe the formation of zinc oxide (ZnO) nanoparticles (NPs) using Pistacia vera soft peel extract. Synthesis of plant-based nanoparticles possesses numerous advantages compared to the conventional physicochemical approaches with different applications in biology and medicine. In the present study Pistacia vera peel extract was used to synthesize ZnO NPs. To investigate the optical and structural features of ZnO nanoparticles synthesized by Pistacia vera peel extract, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible spectrophotometer (UV-Vis), and scanning electron microscope (SEM) were used. The off-yellow hue of the reaction mixture indicated that ZnO NPs were formed. The presence of Pistacia vera peel extract-mediated ZnO NPs was revealed by UV-Visible peaks at 422 nm. In addition, an XRD pattern confirmed the formation of spherical structure nanomaterials with an average size of 42 nm along with the XRD pattern matching the JCPDS card. The Existence of bioactive functional groups effective in reducing the bulk of zinc sulfate to ZnO NPs was further confirmed by FTIR. The SEM images revealed the spherical shape, and the size of nanoparticles, which was within the range of 31.14 to 48 nm. To examine the antibacterial potential of ZnO NPs, a paper disc diffusion technique was used against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus clinical strains in terms of the inhibition zone. In addition, the radical scavenging assay was done by the DPPH test. The green synthesized Pistacia peel extract-mediated ZnO NPs demonstrate striking antioxidative activity at 100 μg mL–1. Using NaBH4, nanoscale zinc oxide can remove methylene blue in only 150 seconds. Furthermore, they remove 98% of methylene blue in 14 minutes under UV light.

    Keywords: Antibacterial, Antioxidant, Dye Reduction, Green Synthesis, Escherichia Coli, Staphylococcus Aureus
  • Fatemeh Dizani, Leila Asadpour *
    Background

    The present study aimed to investigate the effect of thymol on growth inhibition, biofilm inhibition, and antibiotic sensitivity of Escherichia coli isolated from urinary tract infection in Gilan province, Iran.

    Methods

    The disc diffusion and broth microdilution methods were used to investigate the antimicrobial effect of thymol on 30 urinary tract infection isolates of E. coli. Additionally, the time-kill assay was used to investigate the effectiveness of thymol at different time intervals over a period of 24 hours. The anti-biofilm effect of thymol was investigated using the microplate method. Moreover, the effect of thymol on fimH gene expression was investigated. To investigate the effect of thymol on the sensitivity of E. coli isolates to cefotaxime and ciprofloxacin, the checkerboard assay was used.

    Results

    ThymolFF exhibits inhibitory effects on the growth of E. coli isolates and the diameter of the zone of growth inhibition caused by 5 mg of thymol in the studied isolates varied between 15 and 30 mm and minimum inhibitory concentration (MIC) of thymol against MDR E. coli isolates ranged from 1 to 4 mg/mL. Depending on the concentration and the exposure time, bacterial killing was promoted by thymol treatment. The use of thymol decreased the biofilm formation of the isolates by more than 50% compared to the control and also bacterial treatment with thymol led to down-regulation of the fimH gene. Furthermore, enhancing the antibacterial effect of cefotaxime and ciprofloxacin by thymol was demonstrated.

    Conclusion

    The present study found that thymol, a terpenoid of plant origin, exhibited strong killing efficiency, inhibiting the biofilm formation, and enhanced antibiotic sensitivity of E. coli isolated from urinary tract infection.

    Keywords: Escherichia Coli, Thymol, Biofilm, Antimicrobial
  • Mozhgan Fateh, Fatemeh Forohi*, Fatemeh Rafiee
    Background & Objectives

    Urinary tract infection (UTI) is a serious issue affecting both men and women resulting from the invasion of microbial agents into the urinary system. This study aimed to investigate the antimicrobial activity of Lactobacillus casei (L. casei) against Klebsiella pneumoniae (K. pneumoniae) and Escherichia coli (E. coli) isolated from UTI.

    Materials & Methods

    In this study, 100 urine specimens were obtained from medical laboratories in western Tehran. E. coli and K. pneumoniae isolates were identified and subsequently confirmed using polymerase chain reaction (PCR). Antibiotic susceptibility patterns were determined using the disk diffusion method. The antimicrobial activity of L. casei against these strains (four multidrug-resistant isolates from each species) was then evaluated using the agar well diffusion method.

    Results

    From 100 urine specimens, 76 E. coli and 14 K. pneumoniae isolates were identified. Antimicrobial susceptibility testing revealed that imipenem and nitrofurantoin were the most effective antibiotics against E. coli, while amikacin demonstrated the highest efficacy against K. pneumoniae. In the agar well diffusion assay, L. casei generated growth inhibition zones measuring 19.8 mm ± 3 for E. coli and 20.3 mm ± 4 for K. pneumoniae.

    Conclusions

    Lactobacillus casei demonstrates notable antimicrobial efficacy against both E. coli and K. pneumoniae, suggesting its potential as an alternative therapeutic option for UTIs.

    Keywords: Lactobacillus Casei, Escherichia Coli, Klebsiella Pneumoniae, Urinary Tract Infection, Probiotics
  • شایان صفوی، ملیکا پیمان گهر، محدثه خاکپور، فاطمه فردصانعی، فرهاد نیکخواهی*

    پیش زمینه و هدف :

    اشریشیا کلی و کلبسیلا پنومونیه باکتری های مهم ایجادکننده عفونت های بیمارستانی هستند که با کسب پلاسمیدهای کدکننده بتالاکتامازها به آنتی بیوتیک های بتالاکتام مقاوم شده اند. مقاومت به مواد ضدعفونی کننده در این سویه ها نیز مشاهده شده است. بنابراین هدف انجام این مطالعه بررسی اثر ضدمیکروبی ماده ضدعفونی کننده کلرهگزیدین بر روی سویه های اشریشیا کلی و کلبسیلا پنومونیه مقاوم به چند دارو بود.

    مواد و روش کار

    نمونه ها از بخش ICU بیمارستان های شهر قزوین جمع آوری شدند. تمامی ایزوله ها به روش فنوتایپی موردبررسی قرار گرفتند. اثر کلرهگزیدین بروی سویه های انجام شد.

    یافته ها

    از 70 ایزوله اشریشیا کلی 45 ایزوله MDR بودند و از 74 ایزوله کلبسیلا پنومونیه 3/83 بود. تمامی نمونه دارای حساسیت یکسان به کلرهگزیدین بودند. EDTA اثر هم افزایی بر این دو ماده نداشت.

    بحث و نتیجه گیری

    نتایج مطالعه ما نشان داد که کلرهگزیدین به طور موثری می تواند سویه های اشریشیا کلی و کلبسیلا پنومونیه تولیدکننده و غیر تولیدکننده بیوفیلم را از بین ببرد. بنابراین در غلظت های پایین از این ماده ضدعفونی کننده می توان در جهت کنترل مقاومت های آنتی بیوتیکی در باکتری اشریشیا کلی و کلبسیلا پنومونیه مقاوم به چند دارو در عفونت های بیمارستانی استفاده کرد.

    کلید واژگان: کلرهگزیدین, بتالاکتاماز, اشریشیا کلی, کلبسیلا پنومونیه
    Shayan Safavi, Melika Peyman Gohar, Mohadeseh Khakpour, Fatemeh Fardsanei, Farhad Nikkhahi*
    Background & Aims

    Escherichia coli and Klebsiella pneumoniae are important bacteria that cause hospital-acquired infections and have become resistant to beta-lactam antibiotics through the acquisition of beta-lactamase-encoding plasmids. Resistance to disinfectants has also been observed in these strains. Therefore, the aim of this study was to investigate the antimicrobial effect of the disinfectant chlorhexidine on multidrug-resistant strains of Escherichia coli and Klebsiella pneumoniae.

    Materials & Methods

    Clinical samples were collected from the intensive care unit of Qazvin hospital. All isolates were analysed by phenotypic method. Finally, the combined effect of chlorhexidine and EDTA on the collected strains was performed.

    Results

    45% of the 70 Escherichia coli isolates were MDR and 83.3% of the 74 Klebsiella pneumoniae isolates. All samples were equally sensitive to chlorhexidine. EDTA showed no synergistic effect with this substance.

    Conclusion

    The results of our study show that chlorhexidine can effectively destroy Escherichia coli and Klebsiella pneumoniae producing and non-producing biofilm strains. Therefore, this disinfectant can be used at low concentrations to control antibiotic resistance in multidrug-resistant Escherichia coli and Klebsiella pneumoniae bacteria in hospital-acquired infections.

    Keywords: Chlorhexidine, Beta-Lactamase, Escherichia Coli, Klebsiella Pneumoniae
  • Mohammad Bahloli, Hossein Samadi Kafil, Parisa Roshani Asl, Niloufar Rashidi*, Seyyed Reza Moaddab*
    Background

     Escherichia coli is one of the main causes of various diseases worldwide, whose multidrug-resistant strains have caused many public health problems by producing extended-spectrum β-lactamases (ESBLs). The resistance rate varies in different regions. Thus, it is necessary to identify ESBL-producing strains in each region and their antibiotic sensitivity in order to find appropriate treatment options. Hence, the present study aimed to detect the ESBL-producing E. coli strains and their antimicrobial susceptibility pattern in Tabriz, Iran.

    Methods

     This study was conducted at the Imam Reza Hospital in Tabriz from November 20, 2022, to April 20, 2023. A total of 400 E. coli isolates were collected from different clinical specimens. Antimicrobial susceptibility testing was performed by the disk diffusion method. ESBL-producing isolates were detected by the double-disc synergy test method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines.

    Results

     Out of 400 E. coli isolates, 211 (52.75%) were obtained from females, and 189 (47.25%) belonged to males. The mean age of patients was 52.1±27.9 years. Overall, 279 (69.75%) were confirmed as ESBL producers. These producers were mainly recovered from outpatients. The highest antibiotic resistance was observed to ceftriaxone (86.25%) and tetracycline (80.75%), and the least antibiotic resistance was related to imipenem (8%) and amikacin (16.25%), respectively. The rate of antibiotic resistance among ESBL producers was higher than among non-ESBLs.

    Conclusion

     The present study reported a high prevalence of ESBL-producing E. coli among patients referring to Imam Reza hospital in Tabriz. Carbapenems, aminoglycosides, and nitrofurantoins were confirmed as the most efficient drugs for these bacteria, whereas cephalosporins, fluoroquinolones, and sulfonamides were the least effective agents.

    Keywords: Escherichia Coli, Antibiotics, Antimicrobial Susceptibility, Extended-Spectrum Β-Lactamase
نکته
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