| Congresso Brasileiro de Microbiologia 2023 | Resumo: 958-1 | ||||
Resumo:Escherichia coli (E. coli) is an Enterobacteriaceae and is considered an indicator of fecal contamination. In addition, this bacterium harbors several pathogenic serogroups responsible for diseases in humans and animals. Furthermore, E. coli infection becomes more dangerous when the bacteria are resistant to antimicrobials commonly used in human and animal clinics, especially strains producing extended-spectrum -lactamase (ESBL). This study was carried out with 41 strains previously isolated from milk in Mato Grosso and identified although the commercial kit EC-CompactDry® (CapLab, Brazil) as E. coli. Confirmation of the genus and/or species was performed by the conventional method for Enterobacteriaceae (using Eosin and Methylene Blue Agar [E.M.B. ], Triple Sugar and Iron [TSI] and IMViC tests [Indole Methyl Red, Voges Proukauer and Citrate]) for differentiation and identification of Enterobacteriaceae species. After identification of strains, experiments were performed to verify the β-lactamase enzymes produced. Therefore, of these strains, 46.34% (19/41) were identified as E. coli, including 14 strains with typical behavior and 5 with atypical behavior in IMViC tests. However, 53.66% of the strains were divided into 3 and 5 strains, respectively, with 7.31 and 12.19% identified concomitantly as Citrobacter freundii and C. diversus and smaller percentages as 4.88% (2/41) and 2.44% (1/41). The percentages were distributed between strains identified as Enterobacter cloace, E. agglomerans, Klebsiella oxytoca and Proteus mirabilis (4.88%). Percentages of 2.44% represented Edwardsiella strains tarda, Proteus spp., Proteus vulgaris biotypes 2 and 3, as well as Shigella dysenteriae and S. flexneri. Among the 41 strains, 19 that proved to be resistant to two generations of 3rd or 4th generation cephalosporins were submitted to the modified disk approximation method or double-disk synergy test (DDST) to verify whether they produced broad spectrum β-lactamase. Those who in the test showed an increase of > 5 mm in the halo of cephalosporin (ceftiofur) in the presence of amoxicillin-clavulanic acid, compared to the size of the halo recommended by CLSI, were considered positive producers of broad-spectrum β-lactamase enzyme or ESBL. Regarding ESBL identification, eight strains were positive, comprising Edwardsiella tarda (1), Citrobacter diversus (2), C. freundii (1) and E. coli (4). The presence of strains isolated from milk that harbor ESBL constitutes a challenge for the treatment of infections caused by these strains. Thus, it is exceptionally important for studies aimed at understanding the epidemiology of resistance expressed by these strains. Palavras-chave: antimicrobials, β-Lactamase, Enterobacteriaceae, Escherichia coli, food Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior | |||||