{"id":7999,"date":"2024-09-16T14:53:18","date_gmt":"2024-09-16T12:53:18","guid":{"rendered":"https:\/\/veterinarska-stanica-journal.hr\/?post_type=article&p=7999"},"modified":"2024-09-16T14:53:18","modified_gmt":"2024-09-16T12:53:18","slug":"biochemical-characteristics-of-e-coli-isolated-from-food-of-animal-origin","status":"publish","type":"article","link":"https:\/\/journal.h3s.org\/?article=biochemical-characteristics-of-e-coli-isolated-from-food-of-animal-origin","title":{"rendered":"Biochemical characteristics of E. coli<\/em> isolated from food of animal origin"},"content":{"rendered":"

\"\"<\/p>\n

D. Toma\u0161kovi\u0107<\/strong>, L. Hlebi\u0107<\/strong>, L. Peinovi\u0107<\/strong> and A. Humski<\/strong>*<\/p>\n

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Dora TOMA\u0160KOVI\u0106<\/strong>, DMV, PhD, Expert Advisor in Science, Lucija HLEBI\u0106<\/strong>, DMV, Expert Associate in Science, Lovran PEINOVI\u0106<\/strong>, Expert Associate in Science, Andrea HUMSKI<\/strong>*, DMV, PhD, Scientific Advisor in Tenure, Assistant Proffesor (Corresponding author: e-mail: humski@veinst.hr), Croatian Veterinary Institute, Zagreb, Croatia<\/div>\n
\"\"<\/a>https:\/\/doi.org\/10.46419\/vs.56.2.9<\/a><\/div>\n<\/p>\n

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Abstract<\/a>Introduction<\/a>Material and methods<\/a>Results<\/a>Discussion<\/a>Conclusions<\/a>References<\/a>Sa\u017eetak<\/a><\/span><\/div>\n<\/div>\n

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Abstract<\/h2>\n
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Food of animal origin is a potential source of pathogenic E. coli<\/em> that are dangerous to humans. While most strains are intestinal commensals, some can cause intestinal and extraintestinal infections. Their pathogenicity is associated with the presence of virulence genes, phylo-group and, in some strains, biochemical characteristics. In this study, a total of 61 E. coli<\/em> isolates from meat, minced meat, meat preparations and carcass swabs from different animal species were analysed. The biochemical properties of the strains were determined using VITEK2 system and the data was compared with the presence of virulence genes from previous studies. The results showed a correlation between the presence of the eae<\/em> virulence gene and the alkalinization of succinate. In addition, the presence of the virulence gene cnf1<\/em> was correlated with the enzyme tyrosine arylamidase, though the correlation between biochemical characteristics and the presence of virulence genes is questionable due to the small sample size and more strains need to be tested for further conclusions. Although no significant correlations were found between biochemical characteristics and the presence of virulence genes, this study describes the diversity of E. coli<\/em> in the Republic of Croatia. The collected data also reveal new insights into biochemical characteristics of E. coli<\/em> isolated from domestic and wild animals in the Republic of Croatia.<\/p>\n

Key words:<\/strong> Escherichia coli; biochemical characteristics; different animal species<\/em><\/p><\/blockquote>\n

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Introduction<\/h2>\n
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The bacterium Escherichia coli<\/em> (E. coli<\/em>) is a Gram-negative, facultatively anaerobic, rod-shaped bacterium that belongs to the genus Escherichia<\/em> and the family Enterobacteriaceae<\/em> (Bettelheim, 1994). Although most strains are intestinal commensals in numerous animal species and humans (Tenaillon et al<\/em>., 2010), some can cause intestinal and extraintestinal infections (Kaper et al<\/em>., 2004; Denamur et al<\/em>., 2021). The pathogenicity of strains is primarily related to the presence of virulence genes (Kaper et al<\/em>., 2004; Croxen and Finlay, 2010), and for certain serovars, also to biochemical properties.<\/p>\n

To distinguish E. coli<\/em> from other members of the Enterobacteriaceae<\/em> family, individual biochemical tests or ready-made biochemical arrays with a larger number of biochemical properties are used, such as API 20E, API 32, VITEK2 (Habrun, 2014). Other methods such as MALDI-TOF MS, should be mentioned as it has been shown to be a rapid and reliable technique for the identification of bacteria (Singhal et al<\/em>., 2015). The differentiation of E. coli<\/em> from other members of the family can be demonstrated by individual biochemical tests. The most important are a positive reaction to methyl red and indole production, a negative reaction to the Voges-Proskauer (VP) test and the inability to utilise citrate and urea. The use of individual biochemical tests has largely been abandoned due to the development of new technologies. The above mentioned commercially available biochemical tests are predominantly used for the detection of bacterial species due to the simple application, specificity and accuracy of the results (Bettelheim, 1994; Quin et al<\/em>., 1994).<\/p>\n

Selective chromogenic media are used to facilitate the isolation and differentiation of E. coli<\/em> from other bacteria of the Enterobacteriaceae<\/em> family. The growth of the individual microorganisms can be distinguished by utilisation of carbohydrates or other compounds. One of the most important characteristic in about 97% of E. coli<\/em> strains is the ability to produce \u03b2-glucuronidase (Killian and B\u00fclow, 1976, Rice et al<\/em>., 1990). This characteristic enabled the development of the chromogenic selective medium Tryptone Bile X-glucuronide (TBX). It should be emphasised that certain E. coli<\/em>, belonging to the enterohemorrhagic E. coli<\/em> (EHEC), do not have the ability to produce \u03b2-glucuronidase. This pathogroup is important for its ability to produce verotoxins (Verotoxigenic E. coli<\/em> \u2013 VTEC), with serotype O157:H7 its most important representative. The latter is often associated with foodborne outbreaks and haemolytic uremic syndrome (HUS). Along with the inability to produce \u03b2-glucuronidase, it is also characterised by the inability to ferment sorbitol (March and Ratnam, 1986). Therefore, the inability to ferment sorbitol is used as a routine \u201escreening\u201d method to easily distinguish E. coli<\/em> O157 from others (Galar et al<\/em>., 2013) by using Sorbitol-MacConkey medium (SMAC) as a chromogenic selective medium (Thomson-Carter, 2001).
\nThis medium is not satisfactory for isolating other VTEC and is not reliable for isolating all O157, because some strains are sorbitol and \u03b2-glucuronidase positive (Thomson-Carter, 2001). It is also possible to isolate sorbitol-negative colonies that do not belong to the group of enterohaemorrhagic E. coli<\/em> (EHEC), but to the enteropathogenic E. coli<\/em> (EPEC), enterotoxigenic E. coli<\/em> (ETEC) or enteroinvasive E. coli<\/em> (EIEC) (Ojeda et al<\/em>., 1995). Unlike O157, other VTEC strains differ greatly in terms of genotype, serotype and other phenotypic characteristics. According to their biochemical properties and growth on common culture media, they have similar characteristics to non-toxigenic strains, and their identification from faeces, food or other sources is very complex.
\nAn example of the biochemical diversity of VTEC strains is presented by Souza et al<\/em>. (2010), who classified the strains into 14 biotypes by analysing 38 strains with 28 biochemical tests. They highlighted the wide diversity of metabolic characteristics of VTEC strains, which do not differ from non-pathogenic E. coli<\/em> according to biochemical and phenotypic characteristics. In addition, the ability to produce \u03b2-glucuronidase was investigated by Verhaegen et al<\/em>. (2015) as a part of the developmental research of selective chromogenic media for the detection of VTEC serogroups. According to their research, all VTEC strains tested were \u03b2-glucuronidase positive. In regards to other pathogroups, it is important to mention the characteristics of EIEC strains, which are often biochemically different from other E. coli<\/em>. For example, 70% of EIEC strains are lactose negative, mostly lysine decarboxylase-negative and non-motile (Doyle and Padhye, 1989). In addition to the listed biochemical characteristics, Kameyama et al<\/em>. (2015) reported that the negative reaction of sorbose fermentation could be useful for the identification of non-O157\/O26 EHEC strains, while Lehmacher and Bockem\u00fchl (2007) stated that most EIEC and ETEC isolates do not ferment sorbose and that culture media containing L-sorbose could be used for their isolation. In addition to intestinal E. coli<\/em>, it is important to mention the extraintestinal pathogenic E. coli<\/em> (ExPEC) described in the studies of Davies (1976). The results show the biotypes of E. coli<\/em> isolated from samples of patients with urinary tract infections, using tests for lysine and ornithine decarboxylase production (69% and 71% of strains) and sucrose fermentation (41% of strains) to differentiate the biotypes. Based on the results obtained, 574 isolates were categorised into biotypes, 42% of which were classified into two biotypes.<\/p>\n

Biochemical characterisation of bacterial species involves the response of isolates to a broad range of biochemical tests, from sugar fermentation to determination of enzyme activity. Although E. coli<\/em> has characteristic biochemical properties, the isolates are often biochemically variable. According to the stated research, it has been observed that biochemical characterisation is not sufficient to determine strain pathogenicity. In order to determine the pathogenicity of the strain, molecular methods are used to detect the presence of virulence genes.<\/p>\n

The aim of this study was to determine the biochemical characteristics of E. coli<\/em> strains isolated from food of animal origin. Furthermore, to compare with the results of previous studies and determine whether there is a mutual connection between the biochemical characteristics and the presence of virulence genes and whether the biochemical characteristics can be used in daily laboratory work to address suspicions about the potential pathogenicity of E. coli<\/em> isolates.<\/p>\n

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Material and methods<\/h2>\n
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For this study, 61 strains of E. coli<\/em> were isolated from samples originating from: a) poultry meat (n<\/em>=20), b) cattle meat, minced meat, meat preparations and cattle carcass swabs (n<\/em>=16), c) pig meat, minced meat and pig carcass swabs (n<\/em>=15), and d) game meat (n<\/em>=10) obtained for the purpose of regular microbiological examinations. For the isolation of bacterial strains and statistical data processing, the procedures described in a previous study were used (Stojevi\u0107 et al<\/em>., 2022).<\/p>\n

Biochemical analysis of bacterial isolates<\/h3>\n

Biochemical analysis of bacterial isolates was performed using the VITEK2 system (Biomerieux, Marcy-l\u2019\u00c9toile, France). VITEK2 GN cards were used to determine the bacterial species and the biochemical profile of the isolated microorganism.<\/p>\n

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Results<\/h2>\n
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Biochemical characteristics<\/h3>\n

The results show identical biochemical reactions for most isolates, while some were variable. The isolates analysed showed the same biochemical properties according to the reactions: Ala-Phe-ProArylamidase (APPA), Adonitol (ADO), L-Pyrrolidoline (PyrA), L-Arabitol (lARL), D-Cellobiose (dCEL), Beta-Galactosidase (BGAL), Hydrogen Sulfide (H2S) production, Beta-N-Acetyl-Glucosaminidase (BNAG), glumamyl-arylamidase pNA (AGLTp), D-glucose (dGLU), glucose fermentation (OFF), \u03b2-glucosidase (BGLU), D-maltose (dMAL), D-mannitol (dMAN), D-mannose (dMNE), \u03b2-oxylosodase (BXYL), \u03b2-alanine arylamidase pNA (Balap), Lipase (LIP), palatinose (PLE), urease (URE), D-sorbitol (dSOR), D-tagatose (dTAG), D-trehalose (dTRE), sodium citrate (CIT), malonate (MNT), \u03b1-glucosidase (AGLU), \u03b2-N-acetyl-galactosaminidase (NAGA), phosphatase (PHOS), glycine arylamidase (GlyA), lysine decarboxylase (LDC), utilisation of L-histidine (IHISa), coumarate (CMT), glu-gly-arg-arylamidase (GGAA), utilisation of L-malate (IMLTa), Ellmann\u2019s reagent (ELLM) and lactate utilization (ILATa). The isolates showed variable biochemical reactions for: gamma-glutamyl transferase (GGT), L-proline arylamidase (ProA), tyrosine arylamidase (TyrA), sucrose (SAC), 5-keto-D-gluconate (5KG), alkalinisation of L-lactate (ILATk), succinate alkalinisation (SUCT), alpha-galactosidase (AGAL), ornithine decarboxylase (ODC), beta-glucuronidase (BGUR) and resistance to O\/129 (O129R).<\/p>\n

The majority of isolates, regardless of their origin, showed a negative reaction to GGT (91.80%), ProA (93.44%) and 5KG (85.25%). The results showed positive biochemical reactions for TyrA (70.49%), SUCT (73.77%), AGAL (72.13%), O129R (73.77%) and BGUR (75.41%) in most strains, regardless of their origin. Among other variable characteristics, it was observed that all isolates reacted equally positively and negatively to SAC, ILATk and ODC. The results are shown in Table 1.<\/p>\n

\"Table
Table 1<\/strong>. Biochemical characteristics of isolates.<\/figcaption><\/figure>\n

Regarding the origin of the isolates, all isolates reacted equally positive (49.18%) and negative (50.81%) to SAC, regardless of origin, while isolates from pigs (66.67%) and poultry (55%) reacted positively to ILATk, in contrast to the strains from cattle (68.75%), which mostly showed a negative reaction. A similar positive response to ODC was observed in isolates from game (70%) and cattle (75%), in contrast to isolates from poultry in which the majority (65%) reacted negatively (Table 2).<\/p>\n

\"Table
Table 2<\/strong>. Results of biochemical properties in relation to the origin of the isolate.<\/figcaption><\/figure>\n

Comparison of biochemical characteristics and the presence of virulence genes<\/h3>\n

The results of biochemical tests were compared with the presence of virulence genes as described in Stojevi\u0107 et al<\/em>. (2022). Briefly, most isolates showed no significance in terms of the biochemical characteristics detected and their association with the presence of genes encoding virulence factors. The exception were some isolates for which a statistical association was found. Statistical significance was found for isolates that detected the presence of the eae<\/em> gene compared to those that did not detect the presence of this gene and their association with succinate alkalinisation (P<\/em>=0.045) (Table 3).<\/p>\n

\"Table
Table 3<\/strong>. Correlation between isolates possessing the eae<\/em> gene with respect to alkalinisation of succinate.<\/figcaption><\/figure>\n

In addition, isolates with a detected cnf1<\/em> gene were found to have an association and statistical significance in relation to the activity of the arylamidase enzyme towards tyrosine, compared to those in which the gene was not detected (Table 4).<\/p>\n

\"Table
Table 4<\/strong>. Correlation between isolates possessing the cnf1<\/em> gene in relation to tyrosine arylamidase.<\/figcaption><\/figure>\n

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Discussion<\/h2>\n
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E. coli<\/em> has numerous biochemical characteristics. In this study, isolates were biochemically characterised using the automated VITEK2 system. The results obtained from the comparison of the biochemical characteristics show that the studied E. coli<\/em> isolates were biochemically very similar with no significant differences. For this reason, species identification was possible (via the VITEK2 System Product Information), while some isolates show deviations.<\/p>\n

E. coli<\/em> most often associated with foodborne outbreak is the verotoxigenic O157:H7. This serotype has specific biochemical reactions such as the inability to ferment sorbitol and produce \u03b2-glucuronidase. When \u03b2-glucuronidase-negative strains are isolated, the pathogenicity of the isolate and the presence of VTEC serogroup O157 are suspected, as the absence of \u03b2-glucuronidase activity is characteristic to this group. Accordingly, the presence of O157:H7 could be excluded in this study for all isolates positive for sorbitol (n<\/em>=61, 100%) and \u03b2-glucuronidase (n<\/em>=46, 75.41%), and suspected for 15 (24.59%) of the \u03b2-glucuronidase-negative E. coli<\/em> isolates. Results from previous studies have confirmed the negative biochemical reactions to sorbitol and \u03b2-glucuronidase (Leclercq et al<\/em>., 2001), according to which E. coli<\/em> O157:H7 and O157:H(-) differed biochemically from the other strains examined. In contrast, King et al<\/em>. (2014) described a case of foodborne outbreak associated with sorbitol-fermenting E. coli<\/em> O157:[H7] and Verhagen et al<\/em>. (2015) detected \u03b2-glucuronidase activity in 39 VTEC isolates, two EPEC isolates and four commensal E. coli<\/em> isolates isolated from cow\u2019s milk, cattle and human faeces, and cattle carcass swabs. Since biochemical characteristics are not sufficient for the identification of pathogenic strains, the results of this study were compared with the results from previous research (Stojevi\u0107 et al<\/em>., 2022). Accordingly, the presence of VTEC was not detected in \u03b2-glucuronidase-negative isolates and most virulence factor genes were detected in \u03b2-glucuronidase-positive strains. In addition, the absence of \u03b2-glucuronidase enzyme activity and the inability to ferment sorbitol is not considered a guideline for determining the pathogenicity of the isolate.<\/p>\n

In this study, the biochemical properties of E. coli<\/em> in foods of animal origin were determined and compared with previous studies. Although no significant correlation was found between the biochemical properties and the presence of virulence genes, this study described the diversity of E. coli<\/em> isolated in the Republic of Croatia, as by studying their diversity, we can also study their impact on public health. Previous research has shown that certain strains are specific to a particular location and that the diversity of the E. coli<\/em> population has a direct impact on public health (Janezic et al<\/em>., 2013). Further research can focus on monitoring the population of E. coli<\/em> isolated from food and comparing it with isolates of human origin and isolates from the environment. <\/p>\n

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Conclusions<\/h2>\n
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The results of this study describe the biochemical characteristics of E. coli<\/em> in foods of animal origin. The biochemical characterisation showed that they are very similar and that there were no significant differences. By comparison with the presence of virulence genes, a connection was found between the eae<\/em> gene and succinate alkalinisation and the cnf1<\/em> gene and the activity of the enzyme arylamidase towards tyrosine. For the reliability of the observed connection, a larger number of strains with these characteristics should be analysed.<\/p>\n

Future studies on a larger samples size could help to better understand the relationship between biochemical characteristics and virulence factors. This would facilitate identification for the purpose of monitoring E. coli<\/em> isolated from food and thus protecting human health.<\/p>\n

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\nReferences<\/strong> [… show]<\/span><\/a><\/span><\/p>\n

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1.\tBETTELHEIM, K. A. (1994): Bichemical Characteristics of Escherichia coli. In: Gyles, C. L.: Escherichia coli in domestic Animals and Humans. Cab International, Wallingford (3-13).
\n2.\tCROXEN, M. A. and B. B. FINLAY (2010): Molecular mechanisms of Escherichia coli pathogenicity. Nat. Rev. Microbiol. 8, 26-38. 10.1038\/nrmicro2265
\n3.\tDAVIES, B. I. (1975): Biochemical typing of urinary Escherichia coli strains by means od he API 20E Enterobacteriaceae system. Med. Microbiol. 10, 293-298. 10.1099\/00222615-10-3-293
\n4.\tDENAMUR, E., O. CLERMONT, S. BONACORSI and D. GORDON (2021): The population genetics of pathogenic Escherichia coli. Nat. Rev. Microbiol. 19, 37-54. 10.1038\/s41579-020-0416-x
\n5.\tDOYLE, M. P. and V. V. PADHYE (1989): Escherichia coli. In: Doyle, M. P.: Foodborne Bacterial Pathogens. Marcel Dekker Inc, New York (235-283).
\n6.\tGALAR, A., M. KULLDORFF, W. RUDNICK, T. F. O\u2019BRIEN and J. STELLING (2013): Biochemical Phenotypes to Discriminate Microbial Subpopulations and Improve Outbreak Detection. Plos One 8. 10.1371\/journal.pone.0084313
\n7.\tHABRUN (2014): Uzgoj i identifikcija bakterija. U: Herak-Perkovi\u0107, V.: Klini\u010dka veterinarska bakteriologija. Medicinska naklada Zagreb i Hrvatski Veterinarski Institut, Zagreb (51-67).
\n8.\tJANEZIC, K. J., E. W. HENDRICKS, B. A. JANIGA, T. JOHNSON, S. MURPHY, M. E. ROBERTS, S. M. SCOTT, A. N. THEISEN, K. F. HUNG and S. L. DANIEL (2013): Phenotypic and Genotypic Characterization of Escherichia coli Isolated from Untreated Surface Waters. Open Microbiol. J. 7, 9-19. 10.2174\/1874285801307010009
\n9.\tKAMEYAMA, M., J. YABATA, Y. NOMURA and K. TOMINAGA (2015): Biochemical Features and Virulence Gene Profiles of Non-O157\/O26 Enterohemorrhagic Escherichia coli Strains from Humans in the Yamaguchi Prefecture, Japan. Jpn. J. Infect. Dis. 68, 216-220. 10.7883\/yoken.JJID.2014.303
\n10.\tKAPER, J. B., J. P. NATARO and H. L. T. MOBLEY (2004): Pathogenic Escherichia coli. Nat. Rev. Microbiol. 2, 123-140. 10.1038\/nrmicro818
\n11.\tKING, L. A., E., LOUKIADIS, P. MARIANI-KURKDJIAN, et al. (2011): Foodborne transmission of sorbitol-fermenting Escherichia coli O157:[H7] via ground beef: an outbreak in northern France. Clin. Microbiol. Infec. 20, O1136-O1144. 10.1111\/1469-0691.12736
\n12.\tLEMACHER, A. and J. BOCKEM\u0170HL (2007): L-Sorbose utilization by virulent Escherichia coli and Shigella: Different metabolic adaptation of pathotypes. Int. J. Med. Microbiol. 297, 245-254. 10.1016\/j.ijmm.2007.01.007
\n13.\tMARCH, S. B. and S. RATNAM (1986) Sorbitol-MacConkey medium for detection of Escherichia coli O157:H7 associated with hemorrhagic colitis. J. Clin. Microbiol. 23, 869-872. 10.1128\/jcm.23.5.869-872.1986
\n14.\tOJEDA, A., V. PRADO, J. MARTINEZ, C. ARELLANO, A. BORCZYK, W. JOHNSON, H. LIOR and M. M. LEVINE (1995): Sorbitol-Negative Phenotype among Enterohemorrhagic Escherichia coli Strains of Different Serotypes and from Different Sources. J. Clin. Microbiol. 33, 2199-2201. 10.1128\/jcm.33.8.2199-2201.1995
\n15.\tSINGHAL, N., M. KUMAR, P. K. KANAUJIA and J. S. VIRDI (2015): MALDI-TOF mass spectrometry: an emerging technology for microbial identification and diagnosis. Front. Microbiol. 6. 10.3389\/fmicb.2015.00791
\n16.\tSTOJEVI\u0106, D., A. HUMSKI, M. MIKULI\u0106, V. DOBRANI\u0106, I. REIL, S. DUVNJAK, M. BENI\u0106, R. BECK and \u017d. CVETNI\u0106 (2022): Prevalence of virulence genes among Escherichia coli strains isolated from food and carcass swabs of different animal origins in Croatia. J. Vet. Res. 66, 395-402. 10.2478\/jvetres-2022-0045
\n17.\tQUIN, J., M. E. CARTER, B. K. MARKEY and G. R. CARTER (1994): Bacteriology. In: Clinical vetrinary microbiology. Wolf Publishing, London (221).
\n18.\tTENAILLON, O., D. SKURNIK, B. PICARD and E. DENAMUR (2010):, The population genetics of commensal Escherichia coli, Nat. Rev. Microbiol. 8, 207-217. 10.1038\/nrmicro2298
\n19.\tTHOMSON-CARTER, F. (2001): General recovery, characterisation and typing protocols for VTEC. In: Duffy, G., P. Garvey and D. A. MacDowell: Verocytotoxigenic E. coli. Food & nutrition press, INC., Conneticut (91-113). 10.1002\/9780470385098. ch5
\n20.\tVITEK2 Systems Product Information, dostupno na: https:\/\/fardavar.com\/Up-load\/%D9%85%D8%B4%D8%AE%D8%B5%D8%A7%D8%AA%20%D9%85%D8%AD%D8%B5%D9%88%D9%84\/Package%20Inser%20Vitek2\/Package_In-sert_GN.pdf
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Biokemijske karakteristike E. coli<\/em> izdvojene iz hrane \u017eivotinjskog podrijetla<\/h2>\n
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Dr. sc. Dora TOMA\u0160KOVI\u0106<\/strong>, dr. med. vet., stru\u010dni savjetnica u sustavu znanosti, Lucija HLEBI\u0106<\/strong>, dr. med. vet, stru\u010dna suradnica u sustavu znanosti, Lovran PEINOVI\u0106<\/strong>, stru\u010dni suradnik u sustavu znanosti, dr. sc. Andrea HUMSKI<\/strong>, dr. med. vet., znanstvena savjetnica u trajnom zvanju, docentica, Hrvatski veterinarski institut, Zagreb, Hrvatska<\/div>\n
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Hrana \u017eivotinjskog podrijetla predstavlja \u010dest izvor patogenih sojeva Escherichia coli<\/em> opasnih za ljude. Iako su ve\u0107ina sojeva crijevni komenzali, neki od njih mogu prouzro\u010diti crijevne (intestinalne) i izvancrijevne (ekstraintestinalne) infekcije. Njihova je patogenost kod pojedinih serovarova povezana s prisutno\u0161\u0107u gena za \u010dimbenike virulencije, pripadno\u0161\u0107u filogrupi te s biokemijskim svojstvima.
\nU ovom istra\u017eivanju pretra\u017een je 61 izolat bakterije E. coli<\/em> izdvojenih iz uzoraka mesa: mljevenog mesa, mesnih pripravaka i obrisaka trupova razli\u010ditih vrsta \u017eivotinja. Izolatima su odre\u0111ene biokemijske karakteristike VITEK2 sustavom, a podatci su uspore\u0111eni s prisutno\u0161\u0107u gena za \u010dimbenike virulencije obra\u0111enim u prija\u0161njem istra\u017eivanju. Rezultati prikazuju povezanost izme\u0111u prisustva eae<\/em> gena i aktivnosti alkalinizacije sukcinata. Osim navedenog, uo\u010dena je povezanost izme\u0111u prisustva cnf1<\/em> gena i aktivnosti enzima arilamidaze prema tirozinu. S obzirom na mali broj ostvarenih rezultata, nejasna je povezanost izme\u0111u biokemijskih karakteristika i prisutnosti gena za \u010dimbenike virulencije. Stoga su potrebna daljnja istra\u017eivanja s ve\u0107im brojem izolata.
\nIako nisu uo\u010dene zna\u010dajne poveznice izme\u0111u biokemijskih svojstava i prisutnosti gena za \u010dimbenike virulencije, ovim radom prikazane su raznolikosti E. coli<\/em> u prikupljene na podru\u010dju Republike Hrvatske, a prikupljeni podatci prikazuju nova saznanja o biokemijskim karakateristikama E. coli<\/em> u doma\u0107ih i divljih \u017eivotinja na podru\u010dju Republike Hrvatske.<\/p>\n

Klju\u010dne rije\u010di:<\/strong> Escherichia coli, biokemijske karakteristike, razli\u010dite vrste \u017eivotinja<\/em><\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"

D. Toma\u0161kovi\u0107, L. Hlebi\u0107, L. Peinovi\u0107 and A. Humski* Dora TOMA\u0160KOVI\u0106, DMV, PhD, Expert Advisor in Science, Lucija HLEBI\u0106, DMV,<\/p>\n","protected":false},"author":8,"featured_media":0,"menu_order":10,"comment_status":"closed","ping_status":"open","template":"","format":"standard","meta":{"footnotes":""},"categories":[21],"tags":[2421,2422,382],"issuem_issue":[2388],"ppma_author":[65],"class_list":["post-7999","article","type-article","status-publish","format-standard","hentry","category-original-scientific-articles","tag-biochemical-characteristics","tag-different-animal-species","tag-escherichia-coli","issuem_issue-veterinarska-stanica-56-2"],"yoast_head":"\nBiochemical characteristics of E. coli isolated from food of animal origin - CROATIAN VETERINARY JOURNAL<\/title>\n<meta name=\"description\" content=\"In this study, a total of 61 E. coli isolates from meat, minced meat, meat preparations and carcass swabs from different animal species were analysed.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/journal.h3s.org\/?article=biochemical-characteristics-of-e-coli-isolated-from-food-of-animal-origin\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Biochemical characteristics of E. coli isolated from food of animal origin - 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