Assessment of biofilm, enzyme production and antibiotic susceptibility of bacteria from milk pre- and post-pasteurization pipelines in Algeria.

Autor: Didouh N; Université Abou Bekr Belkaid Tlemcen, Algeria; Laboratoire de Microbiologie Appliqué à l'Agroalimentaire au Biomédical et à l'Environnement, 13000 Tlemcen, Algeria., Khadidja M; Université Abou Bekr Belkaid Tlemcen, Algeria; Laboratoire de Microbiologie Appliqué à l'Agroalimentaire au Biomédical et à l'Environnement, 13000 Tlemcen, Algeria; Université Hassiba Benbouali Chlef, Algeria., Campos C; Instituto Português de Oncologia (IPO) do Porto Francisco Gentil, Porto, Portugal., Sampaio-Maia B; Nephrology & Infectious Diseases R&D Group, INEB - Instituto de Engenharia Biomédica, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; Faculdade de Medicina Dentária, Universidade do Porto, Porto, Portugal., Boumediene MB; Université Abou Bekr Belkaid Tlemcen, Algeria; Laboratoire de Microbiologie Appliqué à l'Agroalimentaire au Biomédical et à l'Environnement, 13000 Tlemcen, Algeria., Araujo R; Nephrology & Infectious Diseases R&D Group, INEB - Instituto de Engenharia Biomédica, i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal. Electronic address: ricjparaujo@yahoo.com.
Jazyk: angličtina
Zdroj: International journal of food microbiology [Int J Food Microbiol] 2023 Dec 16; Vol. 407, pp. 110389. Date of Electronic Publication: 2023 Sep 09.
DOI: 10.1016/j.ijfoodmicro.2023.110389
Abstrakt: Bacterial biofilm is a major concern of dairy industry due to its association with milk contamination and its derived products. Algerian pasteurized milk shelf-life does not exceed one day, which may reflect the high level of contamination of this product and presence of extracellular enzymes such as lipases and proteases. This work aimed to investigate the microbial biodiversity in milk-processing surfaces of a dairy plant in Algeria. Therefore, stainless steel cylinders were placed in piping system of the dairy system before and after pasteurization of the milk, being removed after 7 days, for biofilm maturation and microorganism isolation and identification by mass spectrometry. Fifty-nine Gram-positive isolates were identified, namely Bacillus altitudinis, Bacillus cereus, Bacillus pumilus, Bacillus subtilis, Bacillus weithenstephanensis, Enterococcus casseliflavus, Enterococcus faecium, and Staphylococcus epidermidis. In addition, twenty-four Gram-negative isolates were identified, namely Acinetobacter schindleri Enterobacter cloacae, Enterobacter xiangfangensis, Leclercia adecarboxylata, and Raoultella ornithinolytica. Bacterial isolates showed ability for production of extracellular enzymes, being 49 % capable of both proteolytic and lipolytic activities. Milk isolates were tested for the ability to form biofilms on stainless steel. The cell numbers recovered on plate count agar plates from stainless steel biofilms ranged from 3.52 to 6.92 log10 CFU/cm 2 , being the maximum number detected for Enterococcus casseliflavus. Bacterial isolates showed intermediate and/or resistant profiles to multiple antibiotics. Resistance to amoxicillin, cefoxitin and/or erythromycin was commonly found among the bacterial isolates.
Competing Interests: Declaration of competing interest All authors declare no conflict of interest.
(Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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