scholarly journals Molecular characterization of Escherichia coli isolated from milk samples with regard to virulence factors and antibiotic resistance

2021 ◽  
pp. 2410-2418
Author(s):  
Waleed Younis ◽  
Sabry Hassan ◽  
Hams M. A. Mohamed
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
16S Rrna ◽  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
Human Life ◽  
Raw Milk ◽  
Biochemical Tests ◽  
E Coli ◽  
Milk Samples

Background and Aim: Raw milk is considered an essential source of nutrition during all stages of human life because it offers a valuable supply of protein and minerals. Importantly, milk is considered a good media for the growth and contamination of many pathogenic bacteria, especially food-borne pathogens such as Escherichia coli. Thus, the objective of this study was to characterize E. coli and detect its virulence factors and antibiotic resistance from raw milk samples. Materials and Methods: Raw milk samples (n=100) were collected from different localities in Qena, Egypt, and investigated for the presence of E. coli using different biochemical tests, IMViC tests, serotyping to detect somatic antigen type, and molecularly by polymerase chain reaction (PCR) tests. The presence of different virulence and antimicrobial genes (hly, eae, stx1, stx2, blaTEM, tetA(A), and tetB genes) in E. coli isolates was evaluated using PCR. Results: The results demonstrated that 10 out of 100 milk samples were contaminated with E. coli. Depending on serology, the isolates were classified as O114 (one isolate), O27 (two isolates), O111 (one isolate), O125 (two isolates), and untypeable (five isolates) E. coli. The sequencing of partially amplified 16S rRNA of the untypeable isolates resulted in one isolate, which was initially misidentified as untypeable E. coli but later proved as Enterobacter hormaechei. Moreover, antibacterial susceptibility analysis revealed that nearly all isolates were resistant to more than 3 families of antibiotics, particularly to β-lactams, clindamycin, and rifampin. PCR results demonstrated that all E. coli isolates showed an accurate amplicon for the blaTEM and tetA(A) genes, four isolates harbored eae gene, other four harbored tetB gene, and only one isolate exhibited a positive stx2 gene. Conclusion: Our study explored vital methods for identifying E. coli as a harmful pathogen of raw milk using 16S rRNA sequencing, phylogenetic analysis, and detection of virulence factors and antibiotic-resistant genes.

scholarly journals MOLECULAR DETECTION AND CHARACTERIZATION OF ESCHERICHIA COLI ISOLATED FROM RAW MILK SOLD IN DIFFERENT MARKETS OF BANGLADESH

2017 ◽  
Vol 14 (2) ◽  
pp. 271-275 ◽  
Author(s):  
M. A. Islam ◽  
S. M. L. Kabir ◽  
S. K. Seel
Keyword(s):  
Escherichia Coli ◽  
Molecular Detection ◽  
Culture Media ◽  
Raw Milk ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
E Coli ◽  
Milk Samples ◽  
Antimicrobial Sensitivity

     The study was intended for molecular detection of E. coli isolated from raw cow’s milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying staining characteristics, cultural properties on different selective media, biochemical tests, catalase and coagulase test, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found positive for E. coli. 15 Escherichia coli isolates were amplified by 16S rRNA gene based PCR. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the E. coli isolates were resistant to amoxycillin (86.67%) and erythromycin (73.33%) but sensitive to azithromycin (53.33%), ciprofloxacin (86.67%), gentamicin (86.67%), norfloxacin (80%) and streptomycin (66.67%).

scholarly journals Isolation and Molecular Characterization of Shigatoxigenic O157 and Non-O157 Escherichia coli in Raw Milk Marketed in Chittagong, Bangladesh

2021 ◽  
Author(s):  
Md. Kauser-Ul Alam ◽  
Nazmul Sarwar ◽  
Shireen Akther ◽  
Monsur Ahmad ◽  
Paritosh Kumar Biswas
Keyword(s):  
Escherichia Coli ◽  
Molecular Characterization ◽  
Raw Milk ◽  
Selective Medium ◽  
Enterohemorrhagic Escherichia Coli ◽  
Macconkey Agar ◽  
Biochemical Tests ◽  
E Coli ◽  
Milk Samples

Background: Quality and microbial safety of milk is demanding day by day as it is considered as a host for pathogenic and spoilage microorganisms. In this study, isolation and molecular characterization of shigatoxigenic O157 and non-O157 Escherichia coli in raw milk marketed in Chittagong, Bangladesh were done on 186 raw milk samples in Bangladesh. Methods: MacConkey agar was initially used to screen for the presence of E. coli and the suspected growth as evidenced by large pink colonies on MacConkey agar. Finally the organism was verified by plating through Eosin Methylene Blue (EMB) agar (a selective medium for E. coli where it produces metallic sheen) and applying standard biochemical tests for E. coli. The presence of virulent genes, Shiga-like toxin (stx1 and stx2), Intimin (eaeA), O157 antigen rfbE and Enterohemorrhagic Escherichia coli (EHEC) Hemolysin (EHEC) hlyA in the contaminating E. coli population was determined by polymerase chain reaction (PCR) run on a thermocycler (Applied Biosystem, 2720 thermal cycler, Singapore). Result: Among the raw milk samples, 33 samples were identified as E.coli positive and among the isolates, 6 (18.18%) were identified as possible EHEC O157 and rest of the isolates (81.82%) were considered as probable non EHEC O157. About, 3.23% (186 samples) EHEC O157 was isolated from raw milk samples. Then all the 33 isolates were taken under PCR assay for the identification of five virulent genes Stx1, Stx2, eaeA, rfbE and hlyA. No virulent genes were found in non- EHEC O157 isolates, but 4 stx2 (66.67%) and 1 hlyA (16.67%) gene were observed in another 4 EHEC O157 isolates out of 6, but one isolates contained the both genes and hence the prevalence of STEC was 2.15% in raw milk. Result indicated poor hygienic standard of raw milk from uncontrolled environments and the increased public health risk of those consuming raw milk from such uncontrolled sources.

scholarly journals Prevalence of Mastitis and Antibiotic Resistance of Bacterial Isolates from CMT Positive Milk Samples Obtained from Dairy Cows, Camels, and Goats in Two Pastoral Districts in Southern Ethiopia

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1530
Author(s):  
Amanuel Balemi ◽  
Balako Gumi ◽  
Kebede Amenu ◽  
Sisay Girma ◽  
Muuz Gebru ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Dairy Cows ◽  
Raw Milk ◽  
Multidrug Resistant ◽  
Southern Ethiopia ◽  
Resistant Bacteria ◽  
Coagulase Negative Staphylococcus ◽  
Bacterial Isolates ◽  
E Coli ◽  
Milk Samples

A study was carried out from August 2017 to February 2018 on lactating dairy cows, one-humped dromedary camels, and goats to determine mastitis in the Bule Hora and Dugda Dawa districts of in Southern Ethiopia. Milk samples from 564 udder quarters and udder halves from 171 animals consisting of 60 dairy cows, 51 camels, and 60 goats were tested for mastitis. Sixty-four positive udder milk samples were cultured, and bacterial mastitis pathogens were isolated and identified. The antibiotic resistance of bacterial isolates from milk with mastitis was tested against nine antimicrobials commonly used in the study area. Cow- and quarter-level prevalence of mastitis in dairy cows, camels, and goats was 33.3%, 26.3%, and 25% and 17.6%, 14.5%, and 20%, respectively. In cattle, the prevalence was significantly higher in Dugda Dawa than in Bule Hora. Major bacterial isolates were coagulase-negative Staphylococcus species (39.1%), S. aureus (17.2%), S. hyicus (14.1%), and S. intermedius and Escherichia coli (9.4% each). In camels, udder abnormality and mastitis were significantly higher in late lactation than in early lactation. Mastitis tends to increase with parity in camels. E. coli isolates were highly resistant to spectinomycin, vancomycin, and doxycycline, whereas most S. aureus isolates were multidrug-resistant. Most of the rural and periurban communities in this area consume raw milk, which indicates a high risk of infection with multidrug-resistant bacteria. We recommend a community-focused training program to improve community awareness of the need to boil milk and the risk of raw milk consumption.

scholarly journals Identification and antibiogram study of bacterial species isolated from milk samples of different locations in Bangladesh

2016 ◽  
Vol 1 (3) ◽  
pp. 457-462 ◽  
Author(s):  
Md Nuruzzaman Munsi ◽  
Nathu Ram Sarker ◽  
Razia Khatun ◽  
Mohammed Khorshed Alam
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Public Health Importance ◽  
Milk Samples ◽  
First Choice

Cow’s milk containing pathogenic bacteria is an important threat to the consumers. The objectives of the present study were to identify the bacterial agents of public health importance in milk samples (n=35) of different locations and to determine their sensitivity to different antibiotics. The milk samples were collected and transported aseptically and subsequently allowed for culture in bacteriological media, Gram’s staining and biochemical tests for the identification of bacterial species. The bacteria identified were Staphylococcus aureus, Escherichia coli and Salmonella typhi, and their prevalence, in case of vendor milk specimens (n=28), were 96.43%, 53.57% and 35.71% respectively, and of brand milk specimens (n=7), were 42.86 %, 28.57% and 0%, respectively. This suggests that cautionary measures should be taken for quality milk production and consumption. The antibiotic sensitivity test was done by disc diffusion method and the average inhibition zones, in case of Staphylococcus aureus, were 32 mm for oxytetracycline, 26 mm for amoxicillin, 35 mm for ciprofloxacin, 27 mm for cefotaxime, 30 mm for ceftriaxone, 30 mm for azithromycin, and 26 mm for erythromycin; in case of Escherichia coli, were 5 mm for oxytetracycline, 9 mm for amoxicillin, 22 mm for ciprofloxacin, 30 mm for cefotaxime, 31 mm for ceftriaxone, 15 mm for azithromycin, and 0 mm for erythromycin; in case of Salmonella typhi., were 25 mm for oxytetracycline, 24 mm for amoxicillin, 38 mm for ciprofloxacin, 31 mm for cefotaxime, 34 mm for ceftriaxone, 24 mm for azithromycin, and 0 mm for erythromycin. Therefore, ciprofloxacin and ceftriaxone may be the antibiotics of first choice, and cefotaxime and azithromycin may be the second choice among the test antibiotics for the treatment of illness caused by these bacteria.Asian J. Med. Biol. Res. December 2015, 1(3): 457-462

scholarly journals The relationship between phylogenetic classification, virulence and antibiotic resistance of extraintestinal pathogenic Escherichia coli in İzmir province, Turkey

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5470 ◽  
Author(s):  
Elif Bozcal ◽  
Vahap Eldem ◽  
Sohret Aydemir ◽  
Mikael Skurnik
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Sequence Analysis ◽  
16S Rrna ◽  
Virulence Factors ◽  
Phylogenetic Group ◽  
Multi Locus Sequence Typing ◽  
Partial Sequence ◽  
Phylogenetic Classification ◽  
Tract Infections

Background Extraintestinal pathogenic Escherichia coli (ExPEC) is an important bacterium and responsible for many bloodstream infections, including urinary tract infections and even fatal bacteremia. The aim of this research was to investigate whether ExPEC strains isolated from Turkish blood cultures have a relationship between 16S rRNA based phylogenetic clusters and antibiotic resistance profiles, virulence factors or clonal lineages. Methods Phenotypically identified ExPEC blood culture isolates (n = 104) were included in this study. The 16S rRNA partial sequence analysis was performed for genotypic identification of ExPEC isolates. Antibiotic susceptibility and Extended-Spectrum β-Lactamase testing of isolates were performed. Phylogenetic classification (A, B1, B2 and D), Multi Locus Sequence Typing analysis and virulence-associated genes were investigated. Results Based on 16S rRNA partial sequence analysis, 97 out of 104 (93.26%) ExPEC isolates were confirmed as E. coli. Ampicillin (74.22%) and cefuroxime axetil (65.97%) resistances had the highest frequencies among the ExPEC isolates. In terms of phylogenetic classification of ExPEC, D (38.14%, 37/97) was the most prevalent group after A (29.89%, 29/97), B2 (20.61%, 20/97), and B1 (11.34%, 11/97). The sequence types of the 20 ExPEC isolates belonging to the B2 phylogenetic group were analyzed by Multi Locus Sequence Typing. Ten isolates out of 20 (50.0%) were identified as ST131. The other STs were ST95 (n = 1), ST14 (n = 1), ST10 (n = 1), ST69 (n = 1), ST1722 (n = 2), ST141 (n = 1), ST88 (n = 1), ST80 (n = 1), and ST998 (n = 1). Of the ST131 strains, six (60%, 6/10) represented serogroup O25. The most common virulence factor genes were serum resistance factor gene, traT (55.7%) aerobactin siderophore receptor and yersiniabactin encoding genes iutA (45.3%) and fyuA (50.5%), respectively. In addition, PAI (41.2%), iroN (23.7%), hlyA (15.4%), kpsII (13.4%), ompT (13.4%), papG (12.4%), iss (9.3%), cnf1 (7.2%), ibeA (2.06%), and sfaS (2.06%) genes were present in the ExPEC isolates. Conclusion The 16S rRNA-based phylogenetic relationship tree analysis showed that a large cluster was present among 97 ExPEC isolates along with related reference strains. There were 21 main clusters with 32 closely related subclusters. Based on our findings, different clonal lineages of ExPEC can display different antibiotic susceptibilities and virulence properties. We also concluded that virulence factors were not distributed depending on phylogenetic groups (A, B1, B2, and D). The ExPEC isolates belonging to the same phylogenetic group and sequence type could display different resistance and virulence characteristics.

Drug-resistant bacterial pathogens in milk and some milk products

2014 ◽  
Vol 44 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Shajuty Marjan ◽  
Kamal Kanta Das ◽  
Saurab Kishore Munshi ◽  
Rashed Noor
Keyword(s):  
Public Health ◽  
Developing Countries ◽  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Biochemical Tests ◽  
Content Type ◽  
Milk Products ◽  
Milk Samples

Purpose – Current study was carried to detect the presence of pathogenic bacteria including the drug-resistant ones from milk and milk products. The paper aims to discuss these issues. Design/methodology/approach – Twenty-six raw milk samples from ten different areas, 28 pasteurized milk samples from 12 different companies and 26 yogurt samples from ten different sources in Dhaka city were microbiologically analyzed through cultural and biochemical identification of the isolates. Drug resistance trait was also determined by the Kirby-Bauer method on Muller-Hinton agar. Findings – Out of 80 samples studied, 74 were found to harbor pathogens within a range of 102-104 cfu/ml, including Escherichia coli, Salmonella spp., Staphylococcus aureus, and Vibrio spp. The study of antibiogram revealed that most of the isolates were resistant against most of the commonly used antibiotics. Research limitations/implications – Employment of only cultural/ biochemical tests excluding the molecular detection of virulence and/or antibiotic resistance genes might stand as a shortfall of the study. Nevertheless, such basic approach of microbiology can make this type of study replicable in the resource poor settings in the other developing countries. Practical implications – Routine detection of drug-resistant bacteria can further unveil the complications in chemotherapy during the endemic food borne diseases. Social implications – The study outcome/knowledge would aid to a better public health management especially in the developing countries. Originality/value – The presence of drug-resistant pathogenic bacteria in most of the tested milk samples poses a great public health threat, especially to the children. Therefore, the study revealed the necessity of maintaining proper hygienic practice and care in handling and processing of milk and milk products.

Associations between Bovine, Human, and Raw Milk, and Beef Isolates of Non-O157 Shiga Toxigenic Escherichia coli within a Restricted Geographic Area of the United States

2008 ◽  
Vol 71 (5) ◽  
pp. 1023-1027 ◽  
Author(s):  
R. N. COBBOLD ◽  
M. A. DAVIS ◽  
D. H. RICE ◽  
M. SZYMANSKI ◽  
P. I. TARR ◽  
...  
Keyword(s):  
United States ◽  
Escherichia Coli ◽  
Raw Milk ◽  
Geographic Area ◽  
The United States ◽  
Geographic Region ◽  
Toxin Gene ◽  
Sample Type ◽  
E Coli ◽  
Milk Samples

A survey for Shiga toxigenic Escherichia coli in raw milk and beef was conducted within a defined geographic region of the United States. Prevalence rates based on detection of Shiga toxin gene (stx) were 36% for retail beef, 23% for beef carcasses, and 21% for raw milk samples, which were significantly higher than were Shiga toxigenic E. coli isolation rates of 7.5, 5.8, and 3.2%, respectively. Seasonal prevalence differences were significant for stx positivity among ground beef and milk samples. Distribution of stx subtypes among isolates varied according to sample type, with stx1 predominating in milk, stx2 on carcasses, and the combination of both stx1 and stx2 in beef. Ancillary virulence markers eae and ehx were evident in 23 and 15% of isolates, respectively. Pulsed-field gel electrophoresis demonstrated associations between food isolates and sympatric bovine fecal, and human clinical isolates. These data demonstrate that non-O157 Shiga toxigenic E. coli is present in the food chain in the Pacific Northwest, and its risk to health warrants critical assessment.

scholarly journals First isolation of Escherichia coli O157:H7 from faecal and milk specimens from Anatolian water buffaloes (Bubalus bubalus) in Turkey

2008 ◽  
Vol 79 (4) ◽  
Author(s):  
E. Seker ◽  
H. Yardimci
Keyword(s):  
Escherichia Coli ◽  
Raw Milk ◽  
Escherichia Coli O157 ◽  
Water Buffaloes ◽  
E Coli ◽  
Milk Samples ◽  
Cultural Methods ◽  
Faecal Samples

Three hundred rectal faecal samples and 213 raw milk samples obtained from the tanks and containers were examined using standard cultural methods. Escherichia coli O157:H7 was isolated from 11 (3.7 %) of 300 faecal samples and 3 (1.4 %) of 213 raw milk samples. It was determined that 8 (73 %) of E. coli O157:H7 strains isolated from faecal samples originated from water buffaloes younger than 2 years of age and 3 (27 %) from 2-year-old and older water buffaloes. This is the 1st isolation of Escherichia coli O157:H7 from faecal and milk samples of water buffaloes in Turkey.

scholarly journals Virulence and antibiotic resistance profile of avian Escherichia coli strains isolated from colibacillosis lesions in central of Algeria

2019 ◽  
Vol 12 (11) ◽  
pp. 1840-1848 ◽  
Author(s):  
Nacima Meguenni ◽  
Nathalie Chanteloup ◽  
Angelina Tourtereau ◽  
Chafika Ali Ahmed ◽  
Saliha Bounar-Kechih ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Iron Acquisition ◽  
Virulence Gene ◽  
Resistance Profile ◽  
E Coli ◽  
Antibiotic Resistance Profile ◽  
Embryo Lethality

Background and Aim: Avian pathogenic Escherichia coli cause extensive mortality in poultry flocks, leading to extensive economic losses. To date, in Algeria, little information has been available on virulence potential and antibiotics resistance of avian E. coli isolates. Therefore, the aim of this study was the characterization of virulence genes and antibiotic resistance profile of Algerian E. coli strains isolated from diseased broilers. Materials and Methods: In this study, 43 avian E. coli strains isolated from chicken colibacillosis lesions at different years were analyzed to determine their contents in 10 virulence factors by polymerase chain reaction, antimicrobial susceptibility to 22 antibiotics belonging to six different chemical classes and genomic diversity by pulsed-field gel electrophoresis (PFGE). Results: Mainly E. coli isolates (58.1%) carried two at six virulence genes and the most frequent virulence gene association detected were ompT (protectin), hlyF (hemolysin) with 55.8% (p<0.001), and iroN, sitA (iron acquisition/uptake systems), and iss (protectin) with 41.8% (p<0.001). Some strains were diagnosed as virulent according to their virulence gene profile. Indeed, 23.25% of the isolates harbored iroN, ompT, hlyF, iss, and sitA combination, 14% ompT, hlyF, and frzorf4 (sugar metabolism), and 11,6% iroN, hlyF, ompT, iss, iutA (iron acquisition/uptake systems), and frzorf4. The chicken embryo lethality assay performed on five isolates confirmed the potential virulence of these strains. All isolates submitted to PFGE analysis yielded different genetic profiles, which revealed their diversity. Overall, 97.2% of the isolates were resistant to at least one antibiotic and 53.5% demonstrated multi-antimicrobial resistance to three different antimicrobial classes. The highest resistance levels were against nalidixic acid (83.4%), amoxicillin and ampicillin (83.3%), ticarcillin (80.5%), pipemidic acid (75%), and triméthoprim-sulfamethoxazole (66.6%). For beta-lactam class, the main phenotype observed belonged to broad-spectrum beta-lactamases. However, extended-spectrum beta-lactamase associated with three at six virulence factors was also detected in 13 isolates. Two of them were attested virulent as demonstrated in the embryo lethality test which constitutes a real public threat. Conclusion: It would be imperative in avian production to discourage misuse while maintaining constant vigilance guidelines and regulations, to limit and rationalize antimicrobial use.

scholarly journals DIARRHEAGENIC Escherichia coli IN RAW MILK, WATER, AND CATTLE FECES IN NON-TECHNIFIED DAIRY FARMS

2019 ◽  
Vol 20 ◽  
Author(s):  
Laryssa F. Ribeiro ◽  
Mayhara M. C. Barbosa ◽  
Fernanda R. Pinto ◽  
Leticia F. Lavezzo ◽  
Gabriel A. M. Rossi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Dairy Farms ◽  
Raw Milk ◽  
Human Consumption ◽  
E Coli ◽  
Diarrheagenic Escherichia Coli ◽  
Milk Samples ◽  
Cattle Feces ◽  
Eaec Strain

Abstract This study focused on detecting diarrheagenic Escherichia coli, enteropathogenic E. coli (EPEC), Shiga-toxin-producing E. coli (STEC), enterohemorrhagic E. coli (EHEC or STEC:EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC) in raw milk, water, and cattle feces sampled from non-technified dairy farms located in the northeastern São Paulo State, Brazil. Thirty-six water samples were collected at different points, namely, water wells (8 samples), water intended for human consumption (8 samples), water from milking parlor (8 samples), and water intended for animal consumption (7 samples), headwaters (1 sample), rivers (3 samples), and reservoirs (1 sample). Three raw milk samples were taken directly from bulk tanks in each farm, totalizing 24 samples. Feces samples were collected using rectal swabs from 160 bovines (20 animals per farm). E. coli was detected in 128 feces samples (80%), 16 raw milk samples (66.67%), and 20 water samples (55.56%). STEC (26 samples, 16.25%), EPEC (10 samples, 6.25%), STEC: EPEC (5 samples, 3.13%), and STEC: ETEC (1 sample, 0.63%) were the most prevalent strains detected in samples from cattle feces. EPEC, STEC, and STEC: EPEC strains were detected in 4.17% (1 sample), 16.67% (4 samples), and 4.17% (1 sample) of raw milk samples, respectively. STEC strains were detected in water used in the milking parlor, while no EAEC strain was detected. As a conclusion, cattle feces are important contamination sources of pathogenic E. coli in non-technified dairy farms and, consequently, cross-contamination among feces, water, and/or raw milk can occur. The use of quality water and hygienic practices during milking are recommended to avoid contamination since pathogens can be transmitted to humans via raw milk or raw milk cheese ingestion.

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