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1.
Braz J Microbiol ; 2024 May 20.
Article in English | MEDLINE | ID: mdl-38767749

ABSTRACT

This study aimed to evaluate the ability of biofilm formation by L. monocytogenes from the meat processing industry environment, as well as the use of different combinations of detergents, sanitizers, and UV-A radiation in the control of this microorganism in the planktonic and sessile forms. Four L. monocytogenes isolates were evaluated and showed moderate ability to form biofilm, as well as carried genes related to biofilm production (agrB, agrD, prfA, actA, cheA, cheY, flaA, sigB), and genes related to tolerance to sanitizers (lde and qacH). The biofilm-forming isolates of L. monocytogenes were susceptible to quaternary ammonium compound (QAC) and peracetic acid (PA) in planktonic form, with minimum inhibitory concentrations of 125 and 75 ppm, respectively, for contact times of 10 and 5 min. These concentrations are lower than those recommended by the manufacturers, which are at least 200 and 300 ppm for QAC and PA, respectively. Biofilms of L. monocytogenes formed from a pool of isolates on stainless steel and polyurethane coupons were subjected to 14 treatments involving acid and enzymatic detergents, QAC and PA sanitizers, and UV-A radiation at varying concentrations and contact times. All treatments reduced L. monocytogenes counts in the biofilm, indicating that the tested detergents, sanitizers, and UV-A radiation exhibited antimicrobial activity against biofilms on both surface types. Notably, the biofilm formed on polyurethane showed greater tolerance to the evaluated compounds than the biofilm on stainless steel, likely due to the material's surface facilitating faster microbial colonization and the development of a more complex structure, as observed by scanning electron microscopy. Listeria monocytogenes isolates from the meat processing industry carry genes associated with biofilm production and can form biofilms on both stainless steel and polyurethane surfaces, which may contribute to their persistence within meat processing lines. Despite carrying sanitizer tolerance genes, QAC and PA effectively controlled these microorganisms in their planktonic form. However, combinations of detergent (AC and ENZ) with sanitizers (QAC and PA) at minimum concentrations of 125 ppm and 300 ppm, respectively, were the most effective.

2.
J Food Sci Technol ; 61(1): 53-61, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38192700

ABSTRACT

This study aimed to investigate the occurrence and the genetic diversity of Salmonella enterica subsp. enterica in sausages from Southern Brazil, evaluate virulence genes and determine the phenotypic and genotypic basis of antimicrobial and sanitizer resistance. Salmonella was detected in sausage samples with an overall prevalence of 5.5%. The prevalent serovars were S. Infantis and S. Rissen. Pulsed-field gel electrophoresis (PFGE) analysis yielded nine distinct PFGE profiles, and some of them were recurrently recovered in the same establishment on different dates. Among tested isolates, 28.5% showed resistance to at least one antimicrobial agent and a multidrug-resistance (MDR) profile was observed in 21.4%. Resistance occurred most frequently to ampicillin, sulfonamide, trimethoprim/sulfamethoxazole, and trimethoprim. Regarding the genotypic antimicrobial resistance profile, S. Schwarzengrund carried tet(B), strA, strB, and sul2 genes. Benzalkonium chloride and chlorhexidine were more effective than peracetic acid and sodium hypochlorite, showing lower minimum inhibitory concentration values. Six Salmonella serovars were found, demonstrating a potential risk of salmonellosis associated with consuming this food. Salmonella carrying virulence genes, MDR profile, and tolerance to sanitizers is a public health concern and a challenge for the food industry, suggesting that new strategies should be developed to control this pathogen. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05809-w.

3.
FEMS Microbiol Lett ; 3702023 01 17.
Article in English | MEDLINE | ID: mdl-36931897

ABSTRACT

The growing number of Listeria monocytogenes strains displaying increased tolerance to sanitizers widely applied in the food industry is becoming a problem. The aims of this study were to evaluate the susceptibility of L. monocytogenes isolates from food and food industry environments to sanitizers (benzalkonium chloride, sodium hypochlorite, peracetic acid, and chlorhexidine) and heavy metals (cadmium chloride), as well as to investigate the presence of the main genes related to efflux pumps. All 82 isolates showed reduced susceptibility to benzalkonium chloride (MIC from 16 to 128 µg mL-1), sodium hypochlorite (MIC of ≥ 2048 µg mL-1), and peracetic acid (MIC from 512 to ≥ 2048 µg mL-1), while 22 isolates showed reduced susceptibility to cadmium chloride (MIC > 70 µg mL-1). Susceptibility to chlorhexidine was found (MIC from 2 to 16 µg mL-1). PCR-based analysis revealed that mdrl and lde genes were harbored by 14.6% (12/82) and 40.2% (33/82) of the isolates, respectively. This study demonstrates the presence of L. monocytogenes from food and food industry environments with reduced susceptibility to sanitizers commonly used in food processing environments, highlighting the importance of continuous monitoring of the tolerance profile of this microorganism to sanitizers, as well as the need for strict control of sanitation conditions in food industries.


Subject(s)
Benzalkonium Compounds , Listeria monocytogenes , Listeria monocytogenes/genetics , Peracetic Acid , Sodium Hypochlorite , Cadmium Chloride , Chlorhexidine , Food Handling
4.
Braz. arch. biol. technol ; 65: e22210114, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1364452

ABSTRACT

Abstract: This study aimed to analyze the effects of Goji Berry extract (GB, Lycium barbarum) gavage administration on liver tissue oxidative stress in Wistar rats as well as to identify and quantify the content of the major bioactive compounds of the fruit. Four diets were applied: SW - standard diet + water; SG - standard diet + Goji Berry extract (125 mg/kg of animal); PW - palatable diet + water; PG - palatable diet + Goji Berry extract (125 mg/kg of animal). Results showed a significant increase in catalase enzyme activity in the liver of rats treated with GB and also in those intaking the palatable diet without GB when compared to the SW group. An increased mRNA expression of this enzyme in the same tissue and groups was also verified. Regarding lipid peroxidation, the GB extract produced a significant decrease in the oxidation state in the SG and PG groups. The results also showed a significant amount of bioactive compounds in GB extract.

5.
Hig. aliment ; 33(288/289): 2606-2610, abr.-maio 2019. tab
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1482270

ABSTRACT

Diversos estudos relatam distintos níveis de resistência antimicrobiana entre os isolados de L. monocytogenes, o que pode ter implicações no tratamento de listeriose. Este estudo avaliou o perfil de resistência de 30 isolados de L. monocytogenes provenientes de alimentos e ambientes de processamento de alimentos do sul do Brasil. Todos os isolados apresentaram resistência ao ácido nalidíxico e a cefoxitina, além de ter sido observada alta ocorrência de isolados resistentes à clindamicina. Para alguns antimicrobianos (rifampicina, tetraciclina, eritromicina, estreptomicina, meropenem, trimetoprim-sulfametoxazol) foi detectado baixo percentual de resistência e, para os demais antimicrobianos testados, não foi observada resistência. Como conclusão, apesar de ter sido observado perfil de resistência para alguns antimicrobianos, os isolados foram suscetíveis aos antimicrobianos comumente utilizados no tratamento de listeriose.


Subject(s)
Foods of Animal Origin , Drug Resistance, Bacterial , Listeria monocytogenes/isolation & purification , Food Handling
6.
Hig. aliment ; 33(288/289): 460-464, abr.-maio 2019. ilus
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1481976

ABSTRACT

Na última década, a ciência contribuiu significativamente para inúmeros avanços em relação ao tratamento e prevenção do câncer colorretal (CCR), porém, a prevalência global e a taxa de mortalidade permanecem elevadas. Há relatos sobre efeitos benéficos de espécies de Bifidobacterium e Lactobacillus com potencial probiótico na prevenção de CCR. No entanto, a bactéria probiótica Lactococcus lactis subps. lactis é comumente utilizada para fins industriais, não havendo comprovações in vivo sobre seu potencial anticarcinogênico. Visto o interesse emergente dos efeitos benéficos dos probióticos a fim de prevenir ou tratar o CCR, o presente estudo objetivou explorar os efeitos de L. lactis subsp. lactis sobre o CCR. Ratos Wistar receberam doses subcutâneas de 1,2 dimetilhidrazina (DMH) e suspensão de L. lactis subsp. lactis por via oral. Após 20 semanas, os tecidos intestinais foram analisados e de acordo com o resultado, o isolado demonstrou potencial anticarcinogênico contra CCR.


Subject(s)
Animals , Rats , Lactococcus lactis/isolation & purification , Colorectal Neoplasms/therapy , Probiotics/therapeutic use , Anticarcinogenic Agents , Rats, Wistar
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