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1.
Meat Sci ; 188: 108781, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35248942

RESUMO

Vacuum-packed lamb produced in Australia has a shelf-life of 80-90 days under export conditions (-1 to 0 °C). However, access to some markets could involve >90 days transit time. Studies to understand the potential mechanisms of microbial spoilage of vacuum-packed lamb are, therefore, important to assist the development of shelf-life extension methods. Here, we investigated the effects of glucose on the shelf-life of vacuum-packed lamb. This was done by adding glucose (up to 4.64 mmol/kg) to the surface of meat and conducting a series of shelf-life trials, in which the sensorial qualities, bacterial growth, pH, and residual glucose and lactic acid were measured over time. Based on sensory analysis glucose extended the shelf-life, ranging from 8% to >76% increase relative to the control. Glucose reduced meat pH, potentially affecting the microbial community composition and the accumulation of spoilage metabolites. These results indicate that glucose plays an important role in microbial spoilage of vacuum-packed lamb possibly by pH reduction.


Assuntos
Embalagem de Alimentos , Carne Vermelha , Animais , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Glucose , Carne/análise , Carne Vermelha/microbiologia , Ovinos , Vácuo
2.
Meat Sci ; 187: 108765, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35183845

RESUMO

This study evaluates the physicochemical and microbiological properties and sensory parameters of beef patties formulated with black chokeberry (B1), blackberry (B2), red currant (B3) and blueberry (B4) pomace water extracts during refrigerated storage over 9 days. The berry pomace extract treatment significantly decreased the TBARS numbers of the samples (P < 0.05). The lowest total carbonyl content was determined in the groups of B1 and B3 on the 6th day (P < 0.05). The berry pomace extract treatment did not affect the lightness values of the samples (P > 0.05). Beef patties including berry pomace extracts had lower coliform bacteria counts than the control patty C with no extract (P < 0.05), except for day 9. The results suggest that water extract of black chokeberry pomace may be a promising natural preservative among different berries' pomace extracts to improve oxidative stability and increase the microbiological quality of beef patties during refrigerated storage.


Assuntos
Anti-Infecciosos , Antioxidantes , Extratos Vegetais , Carne Vermelha , Animais , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Mirtilos Azuis (Planta)/química , Bovinos , Microbiologia de Alimentos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Carne Vermelha/microbiologia , Refrigeração , Ribes/química , Rubus/química
3.
PLoS One ; 17(1): e0262308, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35030183

RESUMO

BACKGROUND: Food-borne diseases related to the consumption of meat and its products had public health importance worldwide. The problem became worst in Ethiopia as the result of the tradition of eating raw cattle meat. Salmonella species and Escherichia coli are important food-borne pathogens associated with meat contamination. Hence the current study aimed to assess the prevalence and antimicrobial susceptibility of Salmonella species and Extended-spectrum ß-lactamase producing Escherichia coli from raw cattle meat at butcher houses in Hawassa city, Sidama regional state, Ethiopia. METHOD: A cross-sectional study was done on the prevalence and antimicrobial susceptibility pattern of Salmonella species and Extended-spectrum ß-lactamase producing E.coli from raw cattle meat at butcher houses in Hawassa city from September to December 2020. Socio-demographic data were collected using a structured questionnaire and raw cattle meat and swab samples were collected from meat cutting equipment. The collected samples transported using icebox to Hawassa University College of Medicine and Health Sciences Microbiology Laboratory for identification. Samples were grown on different culture media and antimicrobial susceptibility tests were determined by using Kirby disc diffusion method. Data were entered and analyzed into SPSS version 23. Descriptive statistics were done and P-value < 0.05 was considered as statistically significant. RESULT: The overall prevalence of salmonella and ESBL producing E.coli among 556 samples collected from 278 butcher houses was 36 (6.47%) (95% CI: 1.68-1.79) of which 13 (2.3%) were ESBL producing E.coli and 23(4.1%) were salmonella species. Poor hand washing practice (AOR = 2.208; 95% CI: 1.249-3.904) and touching birr while selling meat (AOR = 0.75; 95% CI: (0.433-1.299) were found to be significantly associated with the prevalence of salmonella species and E.coli on cattle meat. The isolates showed moderate levels of resistance (60-70%) against Amoxicillin/ clavulanic acid and high susceptibility (85-100%) against gentamicin, cotrimoxazole, ceftazidime, and tetracycline and the overall multidrug resistance was 33.3%. CONCLUSION: This study revealed moderately high prevalence of salmonella and E.coli due to poor hygiene and sanitation practices in the butcher shops. Furthermore, the existence of ESBL producing E.coli isolates clearly indicate the possible threat to public health. Therefore, inspection by the right agencies must be implemented in order to prevent food-borne outbreaks and antimicrobial resistance.


Assuntos
Escherichia coli/patogenicidade , Carne/microbiologia , Salmonella/patogenicidade , Animais , Antibacterianos/farmacologia , Bovinos , Estudos Transversais , Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções por Escherichia coli/microbiologia , Etiópia/epidemiologia , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Carne/análise , Testes de Sensibilidade Microbiana , Prevalência , Carne Vermelha/microbiologia , beta-Lactamases
4.
Sci Rep ; 12(1): 1242, 2022 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-35075149

RESUMO

The present study was conducted to ascertain the beneficial effects of bioactive peptides on the oxidative stability and functional properties of beef nuggets. In this study, milk casein protein hydrolysates were extracted and incorporated into beef nuggets which were then subjected to different assessment parameters including oxidative stability, functional capability as well as microbial and physico-chemical quality tests were performed for determining the meat quality at different storage periods. The casein protein hydrolysate powder (CPH) was added at different concentrations in nuggets CPH 2%, 4%, 6% and 8%, with reference to storage period of 0, 5, 10 and 15 days at 4 °C. The results regarding total phenolic contents (TPC) and DPPH free radical scavenging assay showed a significant increased with respect to CPH powder and significantly decreased with respect to storage interval. The TVBN, TBARS and POV of the CPH powder incorporated raw beef nuggets also differed significantly within groups with storage time. Higher POV and TBARS were noticed in the CPH 8% incorporated beef nuggets. However, the raw beef nuggets that were made by the incorporation 8% CPH powder, maintained significantly lower level of TBARS at the end of the storage period in contrast with the levels of the control (CPH 0%). The results of the pH and Hunter color test also showed a significant difference with respect to different groups. The microbiological analysis of beef nuggets showed a significant decrease in the level of both the total aerobic and coliform counts and also indicated a decreasing trend in the level of contamination by these bacteria within the groups. This depicted that the casein protein hydrolysate powder (CPH) or simply, the peptide powder has the strong ability to decrease lipid oxidation and related shelf-life retarding natural processes occurring in the meat. It can also greatly enhance the functional properties of the raw meat (beef) and meat products. Thus, it is seen that the bioactive peptides (BAP's) are a key factor in improving the oxidative stability and functional properties of beef nuggets.


Assuntos
Caseínas , Armazenamento de Alimentos , Lipídeos/química , Carne Vermelha/análise , Peroxidação de Lipídeos , Carne Vermelha/microbiologia
5.
J AOAC Int ; 105(3): 889-901, 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-34954799

RESUMO

BACKGROUND: The 3M™ Molecular Detection Assay 2 - STEC Gene Screen (stx) method is based on gene amplification by the use of real time loop-mediated isothermal amplification when used with the 3M Molecular Detection System for the rapid and specific detection of Shiga toxin gene (stx1 and/or stx2) from Shiga toxin-producing Escherichia coli (STEC) in enriched foods. The stx assay does not differentiate between stx1 and stx2 but detects the presence of stx1 and/or stx2. OBJECTIVE: The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) method was evaluated for AOAC®  Performance Tested MethodsSM certification. METHODS: Matrix studies, inclusivity/exclusivity, robustness testing, product stability, and lot-to-lot variability testing were conducted to assess the method's performance. RESULTS: The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) demonstrated equivalent results to the United States Department of Agriculture/Food Safety and Inspection Service Microbiology Laboratory Guidebook Chapter 5C.00 reference method for fresh raw ground beef, and the U.S. Food and Drug Administration Bacteriological Analytical Manual Chapter 4A reference method for fresh spinach. The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) detected all STEC E. coli strains (E. coli strains with stx1 and/or stx2 genes) and did not detect any of the 45 strains from the exclusivity panel. Robustness testing indicated that small variations in critical test parameters did not adversely affect the assay's performance. Product consistency and stability testing demonstrated no differences between the lots evaluated. CONCLUSION: The data collected in these studies demonstrate that the 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) is a reliable method for the rapid and specific detection of Shiga toxin-producing E. coli in raw ground beef and spinach. HIGHLIGHTS: The 3M Molecular Detection Assay 2 - STEC Gene Screen (stx) method is suitable for the rapid and specific detection of Shiga toxin-producing E. coli in fresh raw ground beef, and spinach.


Assuntos
Contaminação de Alimentos , Carne Vermelha , Escherichia coli Shiga Toxigênica , Spinacia oleracea , Animais , Técnicas Bacteriológicas , Bovinos , Microbiologia de Alimentos , Carne Vermelha/microbiologia , Toxina Shiga/análise , Toxina Shiga/genética , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/isolamento & purificação , Spinacia oleracea/microbiologia
6.
Ciênc. rural (Online) ; 52(4): e20210395, 2022. tab
Artigo em Inglês | VETINDEX | ID: biblio-1339691

RESUMO

Different chilling treatments are used before meat storage. The effect of spray chilling (SC) on meat quality appears to vary. Here, we investigated the effects of SC on beef carcass weight loss and meat quality during subsequent storage. The 2-h SC program tested involved 180-s initial spraying, followed by 60-s spray cycles at 540-s intervals. Deboned chuck tender (IMPS 116B) beef cuts were vacuum-packaged and stored for up to 60 d. Purge and cooking losses, Warner-Bratzler shear force, meat colour [CIE L*, a*, b*], and microbiological quality were evaluated. SC reduced carcass weight loss (P<0.001) compared with conventional chilling. However, storage time affected the purge and cooking losses, and Warner-Bratzler shear force. CIE a* and b* values increased (P<0.05) after 30-d aging in both chilling treatments. Pronounced psychrotrophic growth was observed during storage after both treatments. In conclusion, SC can be used to reduce the economic losses associated with meat chilling, without affecting meat quality attributes.


Diferentes tratamentos de resfriamento são utilizados antes da estocagem das carnes. O efeito da aspersão de carcaças (SC) na qualidade da carne parece variar. Neste estudo, investigou-se os efeitos da aspersão de carcaças bovinas na perda de peso e na qualidade da carne durante subsequente estocagem. O programa de aspersão testado foi de um tempo total de 2 h, com uma aspersão inicial de 180 s, seguida por ciclos de aspersão de 60 s em intervalos de 540 s. Os cortes comerciais desossados "Peixinho" (IMPS 116B) foram embalados a vácuo e estocados por até 60 dias. Foram avaliadas as perdas por exsudação e cozimento, força de cisalhamento por Warner-Bratzler, cor da carne (CIE L*, a*, b*) e qualidade microbiológica. SC reduziu a perda de peso da carcaça (P < 0,001) em comparação com o resfriamento convencional. No entanto, o tempo de estocagem influenciou a perda por exsudação, por cozimento e força de cisalhamento. Os valores de CIE a* e b* aumentaram (P < 0,05) após 30 dias de maturação em ambos os tratamentos de resfriamento. O crescimento pronunciado de psicrotróficos foi observado durante a estocagem em ambos os tratamentos. Em conclusão, o SC pode ser usado para reduzir as perdas econômicas associadas ao resfriamento da carne, sem afetar os atributos de qualidade da carne.


Assuntos
Animais , Bovinos , Fenômenos Químicos , Carne Vermelha/microbiologia , Alimentos Congelados/microbiologia , Padrão de Identidade e Qualidade para Produtos e Serviços
7.
Meat Sci ; 183: 108643, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34390897

RESUMO

Slightly acidic electrolyzed water (SAEW) is often used as a disinfectant in beef preservation to ensure microbiological safety. However, it ineffectively inhibit lipid oxidation. Therefore, the combination of SAEW and tea polyphenols (TPs) was tested to inhibit lipid oxidation and microbial growth in beef preservation. SAEW and TPs were selected as the optimum sanitizer and antioxidant, respectively. Then, the inactivation efficacies of different combination treatments of SAEW and TPs of Salmonella enteritidis in beef were compared and treatment of SAEW-TPs (SAEW immersion at an available chlorine concentration of 30 mg/L for 2.5 min, followed by the TPs immersion at a 0.1% concentration for 2.5 min) was selected. Finally, the effectiveness of SAEW-TPs on the microbiological and physicochemical properties of beef during storage was evaluated. The results revealed that the required quality standard of beef treated with SAEW-TPs was prolonged by approximately 9 d at 4 °C, and this treatment had greater antimicrobial and antioxidant effects than did the single treatment.


Assuntos
Desinfetantes/farmacologia , Conservação de Alimentos/métodos , Polifenóis/farmacologia , Carne Vermelha/análise , Animais , Bovinos , Lipídeos , Oxirredução , Carne Vermelha/microbiologia , Salmonella enteritidis/efeitos dos fármacos , Hipoclorito de Sódio/farmacologia , Chá/química , Água/química
8.
Food Microbiol ; 101: 103887, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34579847

RESUMO

The purpose of this study was to investigate the distribution and specify the transmission and cross-contamination of Clostridium perfringens (C. perfringens) in the beef slaughtering and butchering process. The prevalence of 21.2% (150/708) yielded 208 isolates of C. perfringens, including 80.8% type A and 19.2% type D, 0.4% (3/708) samples carried both type A and D strains, and 72.5% type D isolates carried both cpe and atyp.cpb2 genes. C. perfringens were identified through the whole slaughtering process but no type F (cpe and cpa isolates) was found. 69 isolates were further analyzed and classified into 28 PFGE genotypes and clade I contained 94.2% isolates and 24 PFGE genotypes, which showed the genetic diversity and epidemic correlation. Our study traced C. perfringens contamination along the handling processes and showed a gradually ascending contamination rate during the whole process, revealing widespread cross-contamination from the feces and hides of slaughtered cattle to the carcass in the slaughtering workshop, so as from tools and personnel to meat of the cutting workshops. Strains from different slaughterhouses (regions) have high homology, and type A is the predominant toxinotype. It is necessary to monitor and control several key points of cross-contamination during slaughtering process to reduce a risk of C. perfringens infection.


Assuntos
Matadouros , Clostridium perfringens , Contaminação de Alimentos/análise , Carne Vermelha/microbiologia , Animais , Bovinos , China , Infecções por Clostridium/epidemiologia , Infecções por Clostridium/veterinária , Clostridium perfringens/genética , Eletroforese em Gel de Campo Pulsado , Manipulação de Alimentos
9.
Meat Sci ; 184: 108666, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34653801

RESUMO

Forty-eight Churra ewes and their suckling lambs were assigned to four dietary treatments: control (CTRL), VIT-E (500 mg kg-1 TMR vitamin E), GP-5 (5% grape pomace) and GP-10 (10% grape pomace). After slaughter (11.5 kg live weight), longissimus muscle of lambs was sliced, packaged under modified atmosphere (80,20%/O 2:CO 2) and stored in retail conditions. At each sampling point (0, 3, 7, 10, 14 days), microbiological, physicochemical and sensory characteristics were analysed. Vitamin E and GP-5 were found to be effective (p < 0.05) at preventing enterobacteria growth as of day 10. After day 10, vitamin E and grape pomace in the ewe's supplementation reduced metmyoglobin (p < 0.05) lipid oxidation (p < 0.05) and sensory spoilage throughout the storage period. An effect of the grape pomace dosage was observed, with the supplementation at 5% being more effective. Therefore, we can conclude that grape pomace was just as effective as vitamin E in preventing spoilage during retail storage.


Assuntos
Dieta/veterinária , Armazenamento de Alimentos , Carne Vermelha/análise , Vitis , Ração Animal/análise , Animais , Enterobacteriaceae/crescimento & desenvolvimento , Feminino , Lactação/fisiologia , Masculino , Carne Vermelha/microbiologia , Carneiro Doméstico , Vitamina E/administração & dosagem
10.
Meat Sci ; 184: 108696, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34741876

RESUMO

The present research aimed at investigating the application potential of a newly developed chitosan/lauric acid edible coating in preservation of fresh beef under refrigerated storage and aerobic packaging conditions. The 2-cm thick steaks were coated with 2% chitosan (CHI), 1 mM lauric acid in 2% chitosan (CHI/1 mM LA) or 3 mM lauric acid in 2% chitosan (CHI/3 mM LA), and over-wrapped in permeable film. Non-coated samples were used as a control (CON). Results showed that the inhibitory effects against the spoilage bacteria growth, volatile basic nitrogen formation and lipid oxidation of the chitosan coating was increased with the incorporation of lauric acid (p˂0.05). More importantly, the incorporation of lauric acid almost completely protected the meat samples against the discoloration after 21 days of storage. The coating with chitosan or chitosan/lauric acid completely inhibited the formation of bacterial spoilage-derived volatile compounds. Overall, coating of chitosan containing 1-3 mM lauric acid could be a promising method in preservation of fresh beef to improve safety and quality under aerobic packaging condition.


Assuntos
Quitosana , Embalagem de Alimentos/métodos , Ácidos Láuricos , Carne Vermelha/microbiologia , Animais , Bactérias/crescimento & desenvolvimento , Bovinos , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Armazenamento de Alimentos , Substâncias Reativas com Ácido Tiobarbitúrico/análise
11.
Meat Sci ; 184: 108700, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34768181

RESUMO

The current investigation assessed the effect of pectin (PE) biodegradable nanocomposite coating containing curcumin nanoparticles (CNP) and ajowan (Carum copticum) essential oil nanoemulsion (ANE) combined with low-dose gamma irradiation on microbial, physiochemical, and sensorial qualities of lamb loins during refrigeration conditions. Active coating combined with gamma irradiation reduced the count number of mesophilic and psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae; and minimized lipid and protein oxidation changes, total volatile basic nitrogen content, met-myoglobin formation, and color deterioration in the loin samples. The increased shelf-life of lamb loins up to 25 days compared with 5 days assigned for the control group can be associated with the application of ionizing radiation and edible PE coating containing CNP and ANE, which might be due to the synergistic or additive effects of treatments. Overall, as an effective preservation technique, a combination of PE + CNP + ANE and irradiation can be recommended for prolonging the shelf-life of lamb loins during refrigerated storage.


Assuntos
Conservação de Alimentos/métodos , Raios gama , Óleos Voláteis , Carne Vermelha/análise , Carne Vermelha/microbiologia , Animais , Carum/química , Curcumina/química , Irradiação de Alimentos/métodos , Microbiologia de Alimentos , Armazenamento de Alimentos/métodos , Nanocompostos , Pectinas/química , Ovinos
12.
Food Microbiol ; 102: 103916, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809943

RESUMO

Clostridium spp. are ubiquitous bacteria and often found in foods and animals. Some species are pathogenic, others food spoiling or commensals. In this study, 65 cold-tolerant Clostridium spp. strains isolated from variable samples (beef, lamb, venison, feces/skin of wild boars) were investigated. Fifty strains were lecithinase positive; six additionally produced ß-hemolysis. By applying specific qPCR, 16S rRNA gene analysis, RFLP method, and MALDI-TOF MS, they were classified into two major groups: 29 strains were identified as C. tagluense-like, while the other 36 remained unidentified. Subsequently, twenty-two vacuum-packed beef samples were spiked with a single strain from both groups and stored at 4 °C for 8 weeks. The odor of challenged samples was variable (from unchanged, sour/musty, to sulfurous), while color, meat consistency and drip loss were similar to the control group. The ability to produce gas of all tested strains was lower than of C. estertheticum. Even though both groups of cold-tolerant clostridia exhibited similar 16S rRNA genes and biochemical activities, RFLP methods and MALDI-TOF MS are sufficient to differentiate them. In terms of food safety, strains producing lecithinase and hemolysin should be further investigated for their potential to produce substances affecting human and animal health.


Assuntos
Clostridium , Temperatura Baixa , Contaminação de Alimentos , Embalagem de Alimentos , Carne Vermelha , Animais , Bovinos , Clostridium/genética , Cervos , Fosfolipases , RNA Ribossômico 16S/genética , Carne Vermelha/microbiologia , Ovinos , Suínos , Vácuo
13.
Food Microbiol ; 102: 103919, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809945

RESUMO

A cross-sectional survey was undertaken in Belgian beef producing companies to study the current practices and the microbiological load of dry-aged loins (during production) and trimmed steaks (final product). In each company, the temperature and relative humidity of the ripening chamber were measured, and two loins (each in a different stage of the ripening process) were sampled. From the surface of each loin, a lean meat and adipose tissue sample was analysed separately, and different groups of bacteria, yeasts and moulds were enumerated. The average relative humidity in the ripening chambers was 72 ± 13% and the temperature ranged between 0.0 °C and 5.9 °C. During the drying process, most of the lean meat and adipose tissue samples showed high numbers of total psychrotrophic aerobic bacteria, Pseudomonas spp., psychrotrophic lactic acid bacteria, and yeasts, but the variation between loins was high. The microbiological load on freshly cut dry-aged steaks was generally lower than on loin surfaces, but both psychrotrophic aerobic and anaerobic bacteria were present inside several steaks. The water activity inside dry-aged beef steaks was high (aw ≥ 0.98), which could allow growth of psychrotrophic pathogens, though more in-depth studies are necessary to determine potential growth during the storage of (trimmed) steaks or even inside loins during the dry-aging process.


Assuntos
Manipulação de Alimentos , Inocuidade dos Alimentos , Carne Vermelha , Animais , Bélgica , Bovinos , Estudos Transversais , Carne Vermelha/análise , Carne Vermelha/microbiologia
14.
Microbiol Spectr ; 9(3): e0175121, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34787437

RESUMO

A low initial contamination level of the meat surface is the sine qua non to extend the subsequent shelf life of ground beef for as long as possible. Therefore, the short- and long-term effects of a pregrinding treatment with electrolyzed water (EW) on the microbiological and physicochemical features of Piedmontese steak tartare were here assessed on site, by following two production runs through storage under vacuum packaging conditions at 4°C. The immersion of muscle meat in EW solution at 100 ppm of free active chlorine for 90 s produced an initial surface decontamination with no side effects or compositional modifications, except for an external color change that was subsequently masked by the grinding step. However, the initially measured decontamination was no longer detectable in ground beef, perhaps due to a quick recovery by bacteria during the grinding step from the transient oxidative stress induced by the EW. We observed different RNA-based metataxonomic profiles and metabolomic biomarkers (volatile organic compounds [VOCs], free amino acids [FAA], and biogenic amines [BA]) between production runs. Interestingly, the potentially active microbiota of the meat from each production run, investigated through operational taxonomic unit (OTU)-, oligotyping-, and amplicon sequence variant (ASV)-based bioinformatic pipelines, differed as soon as the early stages of storage, whereas microbial counts and biomarker dynamics were significantly distinguishable only after the expiration date. Higher diversity, richness, and abundance of Streptococcus organisms were identified as the main indicators of the faster spoilage observed in one of the two production runs, while Lactococcus piscium development was the main marker of shelf life end in both production runs. IMPORTANCE Treatment with EW prior to grinding did not result in an effective intervention to prolong the shelf life of Piedmontese steak tartare. Our RNA-based approach clearly highlighted a microbiota that changed markedly between production runs but little during the first shelf life stages. Under these conditions, an early metataxonomic profiling might provide the best prediction of the microbiological fate of each batch of the product.


Assuntos
Contaminação de Alimentos/análise , Lactococcus/crescimento & desenvolvimento , Microbiota/efeitos dos fármacos , Carne Vermelha/microbiologia , Streptococcus/crescimento & desenvolvimento , Água/farmacologia , Animais , Bovinos , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Armazenamento de Alimentos/métodos , Lactococcus/efeitos dos fármacos , Lactococcus/isolamento & purificação , Streptococcus/efeitos dos fármacos , Streptococcus/isolamento & purificação , Água/química , Microbiologia da Água
15.
PLoS One ; 16(11): e0259017, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34735481

RESUMO

INTRODUCTION: Anthrax is the highest-ranked priority zoonotic disease in Kenya with about ten human cases annually. Anthrax outbreak was reported in Kisumu East Sub County after some villagers slaughtered and ate beef from a cow suspected to have died of anthrax. We aimed at establishing the magnitude of the outbreak, described associated factors, and assessed community knowledge, attitude, and practices on anthrax. METHODS: We reviewed human and animal records, conducted case search and contact tracing using standard case definitions in the period from July 1through to July 28, 2019. A cross-sectional study was conducted to assess community knowledge, attitude, and practices towards anthrax. The household selection was done using multistage sampling. We cleaned and analyzed data in Ms. Excel and Epi Info. Descriptive statistics were carried out for continuous and categorical variables while analytical statistics for the association between dependent and independent variables were calculated. RESULTS: Out of 53 persons exposed through consumption or contact with suspicious beef, 23 cases (confirmed: 1, probable: 4, suspected: 18) were reviewed. The proportion of females was 52.17% (12/23), median age 13.5 years and range 45 years. The attack rate was 43.4% (23/53) and the case fatality rate was 4.35% (1/23). Knowledge level, determined by dividing those considered to be 'having good knowledge' on anthrax (numerator) by the total number of respondents (denominator) in the population regarding cause, transmission, symptoms and prevention was 51% for human anthrax and 52% for animal anthrax. Having good knowledge on anthrax was associated with rural residence [OR = 5.5 (95% CI 2.1-14.4; p<0.001)], having seen a case of anthrax [OR = 6.2 (95% CI 2.8-14.2; p<0.001)] and among those who present cattle for vaccination [OR = 2.6 (95% CI 1.2-5.6; p = 0.02)]. About 23.2% (26/112) would slaughter and sell beef to neighbors while 63.4% (71/112) would bury or burn the carcass. Nearly 93.8% (105/112) believed vaccination prevents anthrax. However, 5.4% (62/112) present livestock for vaccination. CONCLUSION: Most anthrax exposures were through meat consumption. Poor knowledge of the disease might hamper prevention and control efforts.


Assuntos
Antraz/epidemiologia , Bacillus anthracis/patogenicidade , Surtos de Doenças/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Adolescente , Adulto , Animais , Antraz/microbiologia , Antraz/psicologia , Bovinos , Feminino , Humanos , Quênia/epidemiologia , Gado/microbiologia , Masculino , Produtos da Carne/microbiologia , Pessoa de Meia-Idade , Carne Vermelha/microbiologia , Fatores de Risco , Vacinação , Adulto Jovem , Zoonoses/epidemiologia , Zoonoses/microbiologia
16.
Appl Environ Microbiol ; 87(24): e0135821, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34613750

RESUMO

Intestinal carriage of extended spectrum ß-lactamase (ESBL)-producing Escherichia coli is a frequent, increasing, and worrying phenomenon, but little is known about the molecular scenario and the evolutionary forces at play. We screened 45 veal calves, known to have high prevalence of carriage, for ESBL-producing E. coli on 514 rectal swabs (one randomly selected colony per sample) collected over 6 months. We characterized the bacterial clones and plasmids carrying blaESBL genes with a combination of genotyping methods, whole genome sequencing, and conjugation assays. One hundred and seventy-three ESBL-producing E. coli isolates [blaCTX-M-1 (64.7%), blaCTX-M-14 (33.5%), or blaCTX-M-15 (1.8%)] were detected, belonging to 32 bacterial clones, mostly of phylogroup A. Calves were colonized successively by different clones with a trend in decreasing carriage. The persistence of a clone in a farm was significantly associated with the number of calves colonized. Despite a high diversity of E. coli clones and blaCTX-M-carrying plasmids, few blaCTX-M gene/plasmid/chromosomal background combinations dominated, due to (i) efficient colonization of bacterial clones and/or (ii) successful plasmid spread in various bacterial clones. The scenario "clone versus plasmid spread" depended on the farm. Thus, epistatic interactions between resistance genes, plasmids, and bacterial clones contribute to optimize fitness in specific environments. IMPORTANCE The gut microbiota is the epicenter of the emergence of resistance. Considerable amount of knowledge on the molecular mechanisms of resistance has been accumulated, but the ecological and evolutionary forces at play in nature are less studied. In this context, we performed a field work on temporal intestinal carriage of extended spectrum ß-lactamase (ESBL)-producing Escherichia coli in veal farms. Veal calves are animals with one of the highest levels of ESBL producing E. coli fecal carriage, due to early high antibiotic exposure. We were able to show that calves were colonized successively by different ESBL-producing E. coli clones, and that two main scenarios were at play in the spread of blaCTX-M genes among calves: efficient colonization of several calves by a few bacterial clones and successful plasmid spread in various bacterial clones. Such knowledge should help develop new strategies to fight the emergence of antibiotic-resistance.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana/genética , Escherichia coli , Plasmídeos , Carne Vermelha , Animais , Antibacterianos/farmacologia , Bovinos/microbiologia , Células Clonais , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Plasmídeos/genética , Carne Vermelha/microbiologia , beta-Lactamases/genética
17.
Molecules ; 26(18)2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34576964

RESUMO

The present study aimed to investigate the bioactive compounds in artichoke (Cynara scolymus) powder, having antioxidant and antimicrobial activity, and to determine the effectiveness of artichoke (C. scolymus) powder extract within the minced meat. C. scolymus was extracted using two different methods. The method incorporating high phenolic and flavonoid content levels was used in other analyses and the phenolic and flavonoid contents in C. scolymus extract was determined using LC-QTOF-MS. Antioxidant, antimicrobial, and metmyoglobin (metMb) reducing activities and pH values of the extract-added minced meat samples were measured for 10 days during storage. DPPH, FRAP, and ABTS were used in the antioxidant analyses. The antimicrobial activity of C. scolymus extract was evaluated on five different food pathogens by using the disc diffusion method. The most resistant bacterium was found to be Listeria monocytogenes (18.05 mm ± 0.24). The amount of metMb was measured in the minced meat sample that was added to the extract during storage (p < 0.05). MetMb formation and pH value on the sixth day of storage were found to be at lower levels than in the control group. In conclusion, C. scolymus exhibited a good antimicrobial and antioxidant effect and can be used in storing and packaging the food products, especially the meat and meat products.


Assuntos
Anti-Infecciosos/farmacologia , Cynara scolymus/química , Armazenamento de Alimentos/métodos , Extratos Vegetais/farmacologia , Carne Vermelha , Anti-Infecciosos/química , Antioxidantes/química , Antioxidantes/farmacologia , Cor , Flavonoides/análise , Congelamento , Metamioglobina/metabolismo , Testes de Sensibilidade Microbiana , Fenóis/análise , Extratos Vegetais/análise , Extratos Vegetais/química , Pós/química , Carne Vermelha/microbiologia
18.
Appl Environ Microbiol ; 87(23): e0157421, 2021 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-34550750

RESUMO

The locus of heat resistance (LHR) can confer heat resistance to Escherichia coli to various extents. This study investigated the phylogenetic relationships and the genomic and phenotypic characteristics of E. coli with or without LHR recovered from beef by direct plating or from enrichment broth at 42°C. LHR-positive E. coli isolates (n = 24) were subjected to whole-genome sequencing by short and long reads. LHR-negative isolates (n = 18) from equivalent sources as LHR-positive isolates were short-read sequenced. All isolates were assessed for decimal reduction time at 60°C (D60°C) and susceptibility to the sanitizers E-SAN and Perox-E. Selected isolates were evaluated for growth at 42°C. The LHR-positive and -negative isolates were well separated on the core genome tree, with 22/24 positive isolates clustering into three clades. Isolates within clade 1 and 2, despite their different D60°C values, were clonal, as determined by subtyping (multilocus sequence typing [MLST], core genome MLST, and serotyping). Isolates within each clade are of one serotype. The LHR-negative isolates were genetically diverse. The LHR-positive isolates had a larger (P < 0.001) median genome size by 0.3 Mbp (5.0 versus 4.7 Mbp) and overrepresentation of genes related to plasmid maintenance, stress response, and cryptic prophages but underrepresentation of genes involved in epithelial attachment and virulence. All LHR-positive isolates harbored a chromosomal copy of LHR, and all clade 2 isolates had an additional partial copy of LHR on conjugative plasmids. The growth rates at 42°C were 0.71 ± 0.02 and 0.65 ± 0.02 log(OD) h-1 for LHR-positive and -negative isolates, respectively. No meaningful difference in sanitizer susceptibility was noted between LHR-positive and -negative isolates. IMPORTANCE Resistant bacteria are serious food safety and public health concerns. Heat resistance conferred by the LHR varies largely among different strains of E. coli. The findings in this study show that genomic background and composition of LHR, in addition to the presence of LHR, play an important role in the degree of heat resistance in E. coli and that strains with certain genetic backgrounds are more likely to acquire and maintain the LHR. Also, caution should be exercised when recovering E. coli at elevated temperatures, as the presence of LHR may confer growth advantages to some strains. Interestingly, the LHR-harboring strains seem to have evolved further from their primary animal host to adapt to their secondary habitat, as reflected by fewer genes involved in virulence and epithelial attachment. The phylogenetic relationships among the isolates point toward multiple mechanisms for acquisition of LHR by E. coli, likely prior to its being deposited on meat.


Assuntos
Desinfetantes , Escherichia coli , Temperatura Alta , Carne Vermelha/microbiologia , Animais , Bovinos , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Genômica , Genótipo , Tipagem de Sequências Multilocus , Fenótipo , Filogenia , Sequenciamento Completo do Genoma
19.
Appl Environ Microbiol ; 87(23): e0112621, 2021 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-34550756

RESUMO

Despite the importance of biofilm formation in the contamination of meat by pathogenic Escherichia coli at slaughter plants, drivers for biofilm remain unclear. To identify selection pressures for biofilm, we evaluated 745 isolates from cattle and 700 generic E. coli isolates from two beef slaughter plants for motility, the expression of curli and cellulose, and biofilm-forming potential. Cattle isolates were also screened for serogroup, stx1, stx2, eae, and rpoS. Generic E. coli isolates were compared by source (hide of carcass, hide-off carcass, and processing equipment) before and after the implementation of antimicrobial hurdles. The proportion of E. coli isolates capable of forming biofilms was lowest (7.1%; P < 0.05) for cattle isolates and highest (87.3%; P < 0.05) from equipment. Only one enterohemorrhagic E. coli (EHEC) isolate was an extremely strong biofilm former, in contrast to 73.4% of E. coli isolates from equipment. Isolates from equipment after sanitation had a greater biofilm-forming capacity (P < 0.001) than those before sanitation. Most cattle isolates were motile and expressed curli, although these traits along with the expression of cellulose and the detection of rpoS were not necessary for biofilm formation. In contrast, isolates capable of forming biofilms on equipment were almost exclusively motile and able to express curli. The results of the present study indicate that cattle rarely carry EHEC capable of making strong biofilms in slaughter plants. However, if biofilm-forming EHEC contaminates equipment, current sanitation procedures may not eliminate the most robust biofilm-forming strains. Accordingly, new and effective antibiofilm hurdles for meat-processing equipment are required to reduce future instances of foodborne disease. IMPORTANCE As the majority of enterohemorrhagic E. coli (EHEC) isolates are not capable of forming biofilms, sources were undetermined for biofilm-forming EHEC isolated from "high-event periods" in beef slaughter plants. This study demonstrated that sanitation procedures used on beef-processing equipment may inadvertently lead to the survival of robust biofilm-forming strains of E. coli. Cattle only rarely carry EHEC capable of forming strong biofilms (1/745 isolates evaluated), but isolates with greater biofilm-forming capacity were more likely (P < 0.001) to survive equipment sanitation. In contrast, chilling carcasses for 3 days at 0°C reduced (P < 0.05) the proportion of biofilm-forming E. coli. Consequently, an additional antibiofilm hurdle for meat-processing equipment, perhaps involving cold exposure, is necessary to further reduce the risk of foodborne disease.


Assuntos
Anti-Infecciosos , Biofilmes/crescimento & desenvolvimento , Escherichia coli/crescimento & desenvolvimento , Carne Vermelha/microbiologia , Termotolerância , Animais , Anti-Infecciosos/farmacologia , Bovinos , Celulose , Escherichia coli/patogenicidade , Contaminação de Alimentos , Indústria Alimentícia , Virulência
20.
FEMS Microbiol Lett ; 368(17)2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34472614

RESUMO

The presence of anaerobic microflora on fresh beef carcass and rump steaks, which may contribute to meat spoilage, was explored in this study. A total of 120 carcass and 120 rump steak swabs were collected immediately after slaughtering and boning, respectively from five meat plants, anaerobically incubated and enriched at 4°C for 3 weeks. This was followed by DNA extraction and 16S rRNA amplicon sequencing using the Illumina MiSeq, with subsequent bioinformatics analysis. The enriched microbiota of the samples was classified and grouped into 149 operational taxonomic units (OTUs). The microbiota recovered from both sample types consisted mainly of Carnobacterium, with an average relative abundance of 28.4% and 32.8% in beef carcasses and beef rump steaks, respectively. This was followed by Streptococcus, Serratia, Lactococcus, Enterococcus, Escherichia-Shigella, Raoultella and Aeromonas ranging from 1.5 to 20% and 0.1 to 29.8% in enriched carcasses and rump steak swabs, respectively. Trichococcus, Bacteroides, Dysgomonas, Providencia, Paraclostridium and Proteus were also present ranging from 0 to 0.8% on carcass and 0 to 1.8% on rump steak swabs, respectively. Alpha and beta diversity measurements showed limited diversity between the two sample types, but some differences between samples from the beef plants investigated were evident. This study highlights the presence of potential spoilage bacteria, mainly anaerobic genera on and between carcass and rump steaks, as an indication of contamination on and between these samples.


Assuntos
Bactérias , Sequenciamento de Nucleotídeos em Larga Escala , Carne Vermelha , Anaerobiose , Animais , Bactérias/classificação , Bactérias/genética , Biodiversidade , Bovinos , Microbiologia de Alimentos , Microbiota/genética , RNA Ribossômico 16S/genética , Carne Vermelha/microbiologia
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