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1.
Curr Microbiol ; 80(7): 236, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37286880

RESUMEN

Clostridioides difficile is a human pathogen that is ubiquitous in soil. Despite increasing infection rates and evidence of foodborne transmission, there is limited data on prevalence in soil or which factors influence persistence. The aim of this study was to investigate the prevalence of these bacteria in soil from three different spinach fields and to examine the chemical composition (carbon, organic carbon, nitrogen, organic matter, minerals and pH) and microbiota to gain insight into the factors that may promote/inhibit C. difficile. The overall C. difficile prevalence (10%) was lower than expected (based on international studies) and a significantly (P < 0.05) higher prevalence was obtained in Field 3 (20%) as compared to Fields 1 and 2 (5% each). Analysis of the soil suggested that the pH as well as organic matter, calcium and phosphorus content directly and indirectly (via the microbiota) influenced the prevalence of C. difficile in adjacent fields, where other factors (eg. climate) are similar. Although further studies are required to validate our findings, the data provides the first step in developing potential soil based control strategies.


Asunto(s)
Clostridioides difficile , Suelo , Humanos , Suelo/química , Clostridioides , Spinacia oleracea , Prevalencia , Carbono
2.
Food Microbiol ; 112: 104215, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36906315

RESUMEN

The increased detection of clinical cases of Clostridioides difficile coupled with the persistence of clostridial spores at various stages along the food chain suggest that this pathogen may be foodborne. This study examined C. difficile (ribotypes 078 and 126) spore viability in chicken breast, beef steak, spinach leaves and cottage cheese during refrigerated (4 °C) and frozen (-20 °C) storage with and without a subsequent sous vide mild cooking (60 °C, 1 h). Spore inactivation at 80 °C in phosphate buffer solution, beef and chicken were also investigated to provide D80°C values and determine if PBS was a suitable model system for real food matrices. There was no decrease in spore concentration after chilled or frozen storage and/or sous vide cooking at 60 °C. Non-log-linear thermal inactivation was observed for both C. difficile ribotypes at 80 °C in phosphate buffer solution (PBS), beef and chicken. The predicted PBS D80°C values of 5.72±[2.90, 8.55] min and 7.50±[6.61, 8.39] min for RT078 and RT126, respectively, were in agreement with the food matrices D80°C values of 5.65 min (95% CI range from 4.29 to 8.89 min) for RT078 and 7.35 min (95% CI range from 6.81 to 7.01 min) for RT126. It was concluded that C. difficile spores survive chilled and frozen storage and mild cooking at 60 °C but may be inactivated at 80 °C. Moreover thermal inactivation in PBS was representative of that observed in real food matrices (beef and chicken).


Asunto(s)
Clostridioides difficile , Animales , Bovinos , Clostridioides , Esporas Bacterianas/fisiología , Culinaria , Fosfatos
3.
Food Microbiol ; 116: 104365, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37689419

RESUMEN

This study investigated the combined effect of Ultraviolet (UV) light-emitting diode (LED) technology treatment with refrigerated storage of chicken breast meat over 7 days on Campylobacter jejuni, Salmonella enterica serovar Typhimurium, total viable counts (TVC) and total Enterobacteriaceae counts (TEC). An optimised UV-LED treatment at 280 nm for 6 min decreased inoculated S. Typhimurium and C. jejuni populations by 0.6-0.64 log CFU/g, and TVC and TEC population by 1-1.2 log CFU/g in chicken samples. During a 7-day storage at 4 °C, a 0.73 log reduction in C. jejuni was achieved compared with non-treated samples. Moreover, the UV-LED effectiveness to reduce TVC and TEC during refrigerated storage was compared with a conventional UV lamp and a similar efficiency was observed. The impact of UV-LED and UV lamp devices on the microbial community composition of chicken meat during storage was further examined using 16 S rRNA gene amplicon sequencing. Although similar bacterial reductions were observed for both technologies, the microbial communities were impacted differently. Treatment with the UV conventional lamp increased the proportion of Brochothrix spp. In meat samples, whilst Photobacterium spp. Levels were reduced.


Asunto(s)
Campylobacter , Microbiota , Animales , Pollos , Rayos Ultravioleta , Enterobacteriaceae , Salmonella typhimurium
4.
J Appl Microbiol ; 132(1): 687-695, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34218482

RESUMEN

AIMS: This research tested the anti-Campylobacter properties of organic acids (OA), medium chain fatty acids (MCFA) and essential oils (EO) in vitro and commenced in vivo suitability testing focused on broiler performance. METHODS AND RESULTS: Nine active compounds were tested at different concentrations and times against Campylobacter jejuni in sterile distilled water, Mueller Hinton broth and grower feed digestate (GFD). Sodium caprate (1.5%, v/v), thymol (0.25% and 2.5%, v/v), carvacrol (1.25%, v/v) and potassium sorbate (1.5%, v/v) each achieved C. jejuni reductions of ≥4.5 log10  CFU per ml in GFD, the matrix most representative of the broiler gut, after 60 s. Similar reductions were achieved after 60 min with lactic acid (1.25%, v/v), formic acid (3.1%, v/v), sodium caprylate (1.5%, v/v) and carvacrol (1.25%, v/v). However, in vivo these compounds adversely affected broiler performance, resulting in dimished water intake and reduced weight. CONCLUSIONS: OA, MFCA and EO based compounds are effective anti-Campylobacter treatments in laboratory model studies but cannot be applied in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: This study illustrates that OAs, MCFAs and EOs can achieve significant reductions in Campylobacter in vitro but identifies a major issue, inhibition of broiler performance, preventing their use in practice.


Asunto(s)
Infecciones por Campylobacter , Campylobacter jejuni , Aceites Volátiles , Enfermedades de las Aves de Corral , Alimentación Animal/análisis , Animales , Pollos , Ácidos Grasos , Aceites Volátiles/farmacología
5.
J Appl Microbiol ; 133(5): 3150-3160, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35993276

RESUMEN

AIMS: The aim was to exploit whole genome sequencing (WGS) to assess genomic diversity, identify virulence genes and deduce the proportion of Campylobacter colonized broilers that directly contaminate their carcasses. METHODS AND RESULTS: Campylobacter jejuni isolates (107) from caeca and carcass neck skin samples (50 pairs from the same batch plus 7 individual caeca) sampled at three poultry slaughterhouses over a one-year period were selected for sequencing (MiSeq; Illumina). FastQ files were submitted to BioNumerics for analysis using the wgMLST scheme for allele calling. Campylobacter cgMLST and hierarchical clustering was performed by applying the single linkage algorithm. Sequence types (STs) were determined in silico from the WGS data and isolates were assigned into clonal complexes (CCs) using the Campylobacter PubMLST.org database. Virulence genes were determined by downloading core sequences from the virulence factor database (VFDB) and the National Center for Biotechnology Information (NCBI). A high degree of diversity was observed with 23 different STs identified. ST257 and CC-21 were the most common STs and CCs, respectively. cgMLST analysis suggested that 56% of carcass contamination was a direct result of contamination from caeca from the same batch. Virulence genes known to play a role in human C. jejuni infection were identified such as the wlaN gene and the genes associated with lipooligosaccharide synthesis, which were identified in 30% of isolates. CONCLUSIONS: Caecal colonization was the more plausible occurring source of C. jejuni contamination of broiler carcasses, compared with cross-contamination from another batch or the environment. The high rate of genetic diversity observed amongst caecal isolates is consistent with a wide variety of Campylobacter strains circulating in poultry flocks in Ireland. SIGNIFICANCE AND IMPACT OF STUDY: The results will further inform broiler processors and regulators about the influence and importance of on-farm colonization versus slaughterhouse cross-contamination and the relationship between C. jejuni in caeca and carcasses during processing.


Asunto(s)
Infecciones por Campylobacter , Campylobacter jejuni , Campylobacter , Animales , Humanos , Campylobacter jejuni/genética , Mataderos , Aves de Corral , Virulencia/genética , Pollos , Infecciones por Campylobacter/veterinaria , Secuenciación Completa del Genoma , Genómica , Factores de Virulencia/genética
6.
Foodborne Pathog Dis ; 19(12): 806-816, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36516404

RESUMEN

Clostridioides difficile (basonym Clostridium) is a bacterial enteropathogen associated with cases of C. difficile infection that can result in pseudomembranous colitis, rapid fluid loss, and death. For decades following its isolation, C. difficile was thought to be a solely nosocomial pathogen, being isolated from individuals undergoing antimicrobial therapy and largely affecting elderly populations. More recently, C. difficile spores have been identified in the broader environment, including in food-producing animals, soil, and food matrices, in both ready-to-eat foods and meat products. Furthermore, evidence has emerged of hypervirulent ribotypes (RTs), such as RT078, similar to those cultured in asymptomatic carriers, also being identified in these environments. This finding may reflect on adaptations arising in these bacteria following selection pressures encountered in these niches, and which occurs due to an increase in antimicrobial usage in both clinical and veterinary settings. As C. difficile continues to adapt to new ecological niches, the taxonomy of this genus has also been evolving. To help understand the transmission and virulence potential of these bacteria of importance to veterinary public health, strategies applying multi-omics-based technologies may prove useful. These approaches may extend our current understanding of this recognized nosocomial pathogen, perhaps redefining it as a zoonotic bacterium. In this review, a brief background on the epidemiological presentation of C. difficile will be highlighted, followed by a review of C. difficile in food-producing animals and food products. The current state of C. difficile taxonomy will provide evidence of Clade 5 (ST11/RT078) delineation, as well as background on the genomic elements linked to C. difficile virulence and ongoing speciation. Recent studies applying second- and third-generation sequencing technologies will be highlighted, and which will further strengthen the argument made by many throughout the world regarding this pathogen and its consideration within a One Health dimension.


Asunto(s)
Clostridioides difficile , Infecciones por Clostridium , Infección Hospitalaria , Salud Única , Animales , Clostridioides/genética , Ribotipificación , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/veterinaria , Infecciones por Clostridium/microbiología
7.
Food Microbiol ; 95: 103717, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33397630

RESUMEN

The objective of this study was to compare the effect of current (10 °C for 10 h followed by 0 °C with a low fan speed) versus four alternative beef carcass chilling regimes, ranging from -6 °C to 0 °C and wind speeds between 1.5 and 6 m/s on the microbiology of beef carcasses. The temperature and relative humidity (RH) in the chillers, the carcass core and surface temperature, pH, water activity (aw) and carcass weight (drip) loss were recorded. Bacterial concentrations (total viable counts (TVC), total Enterobacteriaceae counts (TEC), Pseudomonas spp., lactic acid bacteria (LAB) and Brochothrix thermosphacta) were also monitored. Similar pH, aw and drip loss (2%) values were obtained regardless of chilling regime. For the most part, bacterial concentrations were also similar and, where statistically significant (P < 0.05) counts occurred, the reductions were low (≤1 log10 cfu/cm2). It was concluded that the current chilling regime was as effective as the tested alternatives in terms of the bacterial quality of the carcasses.


Asunto(s)
Brochothrix/crecimiento & desarrollo , Enterobacteriaceae/crecimiento & desarrollo , Conservación de Alimentos/métodos , Carne/microbiología , Pseudomonas/crecimiento & desarrollo , Animales , Carga Bacteriana , Brochothrix/genética , Brochothrix/aislamiento & purificación , Bovinos , Frío , Recuento de Colonia Microbiana , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Conservación de Alimentos/instrumentación , Carne/análisis , Pseudomonas/genética , Pseudomonas/aislamiento & purificación
8.
Food Microbiol ; 98: 103769, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33875205

RESUMEN

The transfer of blown pack spoilage causing Clostridium spores from the farm to the meat plant is of growing concern to the meat industry. This study investigated the environmental niches of these Clostridium spp., specifically Clostridium estertheticum and Clostridium gasigenes in the beef and sheep farm environments in New Zealand. Faecal, soil, grass, drinking water, puddle water and feed (fodder beet, hay, bailage and silage, where available) samples were collected on five beef and sheep farms during Winter and Spring in 2018, in North and South Island, respectively. Beef and sheep farm samples were tested for C. estertheticum and C. gasigenes using enrichment plus PCR, qPCR and direct plating. C. estertheticum was detected in bovine faecal (4%), soil (2-18%) and grass (0-12%) samples at concentration of up to 2.0 log10 cfu/g. C. gasigenes were found in 18-46% of faecal, 16-82% of soil, 12-44% of grass, 0-44.4% of drinking water and 0-58.3% of puddle water samples tested and the direct counts ranged from 2.4 log10 cfu/ml in puddle water to 3.4 log10 cfu/g in soil. C. estertheticum were detected by qPCR in sheep farms in ovine feces (2.3%), soil (2.3%) and fodder beet (10%). All other sample types (grass, drinking water, puddle water, baleage, hay, silage and fodder beet) were negative using direct and enrichment plus PCR methods. In contrast C. gasigenes was detected in of faecal (22.7-38.6%), soil (22.7-84.1%), grass (17.5-34.1%) drinking water (35.7-78.6%), puddle water (33.3-40%), hay baleage (57%), silage (2%) and fodder beet (10%) at concentrations of up to 3.7 log10 cfu/g/ml. It was concluded that C. estertheticum and C. gasigenes were common on beef and sheep farms with the latter having higher incidence and mean concentration.


Asunto(s)
Clostridium/crecimiento & desarrollo , Microbiología Ambiental , Carne/microbiología , Mataderos , Crianza de Animales Domésticos , Animales , Bovinos , Clostridium/clasificación , Clostridium/genética , Clostridium/aislamiento & purificación , Granjas , Heces/microbiología , Contaminación de Alimentos/análisis , Embalaje de Alimentos/instrumentación , Embalaje de Alimentos/métodos , Carne/análisis , Nueva Zelanda , Reacción en Cadena en Tiempo Real de la Polimerasa , Estaciones del Año , Ovinos
9.
Food Microbiol ; 98: 103781, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33875209

RESUMEN

An increasing proportion of Clostridioides difficile infections (CDI) are community acquired. This study tested farm, abattoir and retail food samples for C. difficile, using peer reviewed culture and molecular methods. The contamination rate on beef, sheep and broiler farms ranged from 2/30 (7%) to 25/30 (83%) in faeces, soil and water samples, while concentrations ranged from 2.9 log10 cfu/ml to 8.4 log10 cfu/g. The prevalence and associated counts were much lower in abattoir samples. Although 26/60 were C. difficile positive by enrichment and PCR, only 6 samples yielded counts by direct plating (1.1 log10 cfu/cm2 to 5.1 log10 cfu/g). At retail, 9/240 samples were C. difficile positive, including corned beef (1), spinach leaves (2), iceberg lettuce, little gem lettuce, wild rocket, coleslaw, whole milk yogurt and cottage cheese (1 sample each), with counts of up to 6.8 log10 cfu/g. The tcdA, tcdB, cdtA, cdtB, tcdC and tcdR genes were detected in 41%, 99.2%, 33.6%, 32%, 46.7% and 31.1%, respectively, of the 122 C. difficile isolates obtained. It was concluded that although the prevalence of C. difficile decreased along the food chain, retail foods were still heavily contaminated. This pathogen may therefore be foodborne, perhaps necessitating dietary advice for potentially vulnerable patients.


Asunto(s)
Clostridioides difficile/aislamiento & purificación , Infecciones por Clostridium/veterinaria , Contaminación de Alimentos/estadística & datos numéricos , Carne/microbiología , Verduras/microbiología , Mataderos/estadística & datos numéricos , Animales , Bovinos , Pollos , Clostridioides difficile/clasificación , Clostridioides difficile/genética , Clostridioides difficile/crecimiento & desarrollo , Infecciones por Clostridium/epidemiología , Infecciones por Clostridium/microbiología , Seguridad de Productos para el Consumidor , Granjas/estadística & datos numéricos , Heces/microbiología , Contaminación de Alimentos/análisis , Contaminación de Alimentos/economía , Humanos , Irlanda/epidemiología , Carne/economía , Ovinos , Verduras/economía
10.
Food Microbiol ; 95: 103688, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33397618

RESUMEN

This study examined the impact of key processing stages and flock variables on the prevalence of Campylobacter on broiler carcasses. Overall, the prevalence of Campylobacter was 62% in caeca, and 68%, 65% and 62% in neck skin samples collected after evisceration, final wash and carcass chilling, respectively. Campylobacter were found in 32% of caeca, and 52%, 40% and 32% of neck skin samples collected after evisceration, final wash and carcass chilling, respectively from first thin broiler batches. Final thin broiler batches were more frequently contaminated with prevalences of 83% found in caeca, 80% in neck skin samples collected after evisceration and 83% found in neck skin samples collected after both final wash and carcass chilling stages (p < 0.05). Thinning status had a significant effect on Campylobacter counts with significantly higher counts observed in samples from final thin batches (p < 0.05). Highest Campylobacter concentrations in neck skin samples were observed at the evisceration stage in both first and final thin samples, with counts ranging from 2.0 to 3.8 log10 CFU/g and 2.3 to 4.8 log10 CFU/g in first and final thin batches, respectively. All first thin samples had counts below the European Union (EU) Process Hygiene Criterion threshold level of 3 log10 CFU/g after chilling while 52% of final thin batches had counts above this limit.


Asunto(s)
Campylobacter/crecimiento & desarrollo , Carne/microbiología , Mataderos , Animales , Campylobacter/aislamiento & purificación , Ciego/microbiología , Pollos , Recuento de Colonia Microbiana , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Manipulación de Alimentos/normas , Higiene
11.
J Environ Manage ; 299: 113627, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34467857

RESUMEN

Animal waste contains high numbers of microorganisms and therefore can present a potential biological threat to human health. During episodic rainfall events resulting in runoff, microorganisms in the waste and soil may migrate into surface runoff, contaminating surface water resources. A probabilistic human exposure (HE) model was created to determine exposure to faecal indicator bacteria (FIB): total coliforms (TC), E. coli and enterococci following application of bio-based fertiliser (dairy cattle slurry, digestate) to grassland; using a combination of experimental field results and literature-based data. This step was followed by a quantitative microbial risk assessment (QMRA) model for pathogenic E. coli based on a literature-based dose-response model. The results showed that the maximum daily HE (HEdaily) is associated with E. coli for unprocessed slurry (treatment T1) on day 1, the worst-case scenario where the simulated mean HEdaily was calculated as 2.84 CFU day -1. The results indicate that the overall annual probability of risk (Pannual) of illness from E. coli is very low or low based on the WHO safe-limit of Pannual as 10 -6. In the worst-case scenario, a moderate risk was estimated with simulated mean Pannual as 1.0 × 10 -5. Unpasteurised digestate application showed low risk on day 1 and 2 (1.651 × 10 -6, 1.167 × 10 -6, respectively). Pasteurised digestate showed very low risk in all scenarios. These results support the restriction imposed on applying bio-based fertiliser if there is any rain forecast within 48 h from the application time. This study proposes a future extension of the probabilistic model to include time, intensity, discharge, and distance-dependant dilution factor. The information generated from this model can help policymakers ensure the safety of surface water sources through the quality monitoring of FIB levels in bio-based fertiliser.


Asunto(s)
Escherichia coli , Fertilizantes , Pradera , Microbiología del Agua , Animales , Bacterias , Bovinos , Exposición a Riesgos Ambientales , Heces/microbiología , Fertilizantes/microbiología , Humanos , Medición de Riesgo
12.
Compr Rev Food Sci Food Saf ; 19(4): 1353-1377, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33337085

RESUMEN

Campylobacteriosis is one of the most common bacterial infections worldwide causing economic costs. The high prevalence of Campylobacter spp. in poultry meat is a result of several contamination and cross-contamination sources through the production chain. Moreover, survival mechanisms, such as biofilm formation, viable but nonculturable state, and antimicrobial resistance, enable its persistence during food processing. Therefore, mitigation strategies are necessary in order to avoid and/or inactivate Campylobacter at farm, abattoir, industry, and retail level. In this review, a number of potential strategies and novel technologies that could reduce the prevalence of Campylobacter in poultry meat have been identified and evaluated to provide a useful overview. At farm level for instance, biosecurity, bacteriocins, probiotics, feed and water additives, bacteriophages, and vaccination could potentially reduce colonization in chicken flocks. However, current technologies used in the chicken slaughter and processing industry may be less effective against this foodborne pathogen. Novel technologies and strategies such as cold plasma, ultraviolet light, high-intensity light pulses, pulsed electric fields, antimicrobials, and modified atmosphere packaging are discussed in this review for reducing Campylobacter contamination. Although these measures have achieved promising results, most have not been integrated within processing operations due to a lack of knowledge or an unwillingness to implement these into existing processing systems. Furthermore, a combination of existing and novel strategies might be required to decrease the prevalence of this pathogen in poultry meat and enhance food safety. Therefore, further research will be essential to assess the effectiveness of all these strategies.


Asunto(s)
Infecciones por Campylobacter/prevención & control , Campylobacter , Microbiología de Alimentos , Enfermedades de las Aves de Corral/microbiología , Aves de Corral/microbiología , Animales , Manipulación de Alimentos/métodos , Enfermedades de las Aves de Corral/prevención & control
13.
J Appl Microbiol ; 127(3): 648-657, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31021487

RESUMEN

AIMS: Information on the gut microbiota of salmon is essential for optimizing nutrition while maintaining host health and welfare. This study's objectives were to characterize the microbiota in the GI tract of Atlantic salmon (Salmo salar) farmed in waters off the west coast of Ireland and to investigate whether there is a difference in microbiota diversity between the proximal and distal regions of the intestine. METHODS AND RESULTS: The microbiota from the proximal and distal intestine (PI and DI, respectively) of Atlantic salmon was examined using MiSeq Illumina high-throughput sequencing of the 16S ribosomal RNA gene. The PI region had greater bacterial diversity than the DI region. Six phyla were present in the DI samples, dominated by Tenericutes and Firmicutes. These six phyla were also amongst the 12 phyla detected in the PI samples. The PI microbiota was dominated by Tenericutes, Firmicutes, Bacteroidetes and Proteobacteria. A core microbiota of 20 operational taxonomic units (OTUs) common to both regions was observed. CONCLUSIONS: It was concluded that Tenericutes were the dominant phylum in both PI and DI samples, and the PI region had greater Shannon and Simpson diversity of bacteria. However, further work is required to identify the functionality of the salmon microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study determined the composition and diversity of the intestinal microbiota in adult salmon from a commercial fishery and provides data to improve our understanding of their contributions to the nutrition, health and welfare of Atlantic salmon farmed in Irish waters.


Asunto(s)
Microbioma Gastrointestinal , Salmo salar/microbiología , Animales , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Biodiversidad , Firmicutes/aislamiento & purificación , Explotaciones Pesqueras , Intestinos/microbiología , Irlanda , Proteobacteria/aislamiento & purificación , ARN Ribosómico 16S/genética
14.
Food Microbiol ; 77: 38-42, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30297054

RESUMEN

This study investigated the growth of indicator and spoilage bacteria on whole Atlantic salmon (Salmo salar) stored aerobically at 2 °C. On days 0, 2, 3, 6, 8 and 10 microbiological analysis was carried out on inner flesh and outer skin samples as well as outer skin swabs (25 cm2 surface areas). Mesophilic total viable counts (TVCm) on skin, flesh and swab samples increased from 1.9, 1.1 and 2.7 log10 CFUcm2 to 6.0, 5.1 and 5.7 log10 CFU/cm2 after 10 days, respectively. Psychrotrophic counts (TVCp), increased from 2.2, 1.8 and 3.1 log10 CFU/cm2 to 6.2, 5.3 and 5.9 log10 CFU/cm2, for skin, flesh and swab samples respectively. Hydrogen sulphide producing bacteria (HSPB), lactic acid bacteria (LAB), Pseudomonas spp., Brochothrix thermosphacta and Photobacterium spp. grew well with similar growth rates (mean generation times of 17.2-26 h). It was concluded that the shelf-life of salmon at 2 °C was approximately 10 days and that HSPB, LAB, Pseudomonas spp., Br. thermosphacta and Photobacterium spp. may be a better indicator of fish spoilage rather than TVC growth, with a count of 5-6 log10 CFU/cm2 indicating the end of shelf-life.


Asunto(s)
Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Frío , Explotaciones Pesqueras , Almacenamiento de Alimentos , Salmo salar/microbiología , Animales , Bacterias/clasificación , Bacterias/metabolismo , Recuento de Colonia Microbiana , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Embalaje de Alimentos , Sulfuro de Hidrógeno/metabolismo , Concentración de Iones de Hidrógeno , Hielo , Alimentos Marinos/microbiología , Factores de Tiempo
15.
Arch Virol ; 163(8): 2139-2154, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29687158

RESUMEN

Campylobacter phage vB_CjeM_Los1 was recently isolated from a slaughterhouse in the Republic of Ireland using the host Campylobacter jejuni subsp. jejuni PT14, and full-genome sequencing and annotation were performed. The genome was found to be 134,073 bp in length and to contain 169 predicted open reading frames. Transmission electron microscopy images of vB_CjeM_Los1 revealed that it belongs to the family Myoviridae, with tail fibres observed in both extended and folded conformations, as seen in T4. The genome size and morphology of vB_CjeM_Los1 suggest that it belongs to the genus Cp8virus, and seven other Campylobacter phages with similar size characteristics have also been fully sequenced. In this work, comparative studies were performed in relation to genomic rearrangements and conservation within each of the eight genomes. None of the eight genomes were found to have undergone internal rearrangements, and their sequences retained more than 98% identity with one another despite the widespread geographical distribution of each phage. Whole-genome phylogenetics were also performed, and clades were shown to be representative of the differing number of tRNAs present in each phage. This may be an indication of lineages within the genus, despite their striking homology.


Asunto(s)
Bacteriófagos/genética , Bacteriófagos/aislamiento & purificación , Genoma Viral , Myoviridae/genética , Mataderos , Animales , Bacteriófagos/clasificación , Bacteriófagos/ultraestructura , Campylobacter/virología , Genómica , Irlanda , Microscopía Electrónica de Transmisión , Myoviridae/clasificación , Myoviridae/aislamiento & purificación , Sistemas de Lectura Abierta , Filogenia , Aves de Corral/virología , Proteínas Virales/genética
16.
Food Microbiol ; 68: 1-6, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28800816

RESUMEN

This study investigated bacteriophage (phage) mediated transfer of the vtx2 gene from a donor Escherichia coli (C600φ3538(Δvtx2::cat)) to enteropathogenic (EPEC), enterotoxigenic (ETEC), enteroaggregative (EAEC), enteroinvasive (EIEC) and diffusely adherent (DAEC) E. coli strains in LB broth, milk, ground beef and lettuce. Two bacterial concentrations for both the E. coli donor and recipient strains, 3 and 5 log10 CFU/ml (LB broth and milk)/g (beef) or/cm2 (lettuce), were used. When transductants were obtained, the location of insertion of the phage (insertion sites wrbA, yehA, sbcB, yecE and/or Z2577) in the E. coli chromosome was investigated by PCR. The vtx2 gene was readily transferred to EAEC O104:H4 (E99518) in all matrices and inserted into the chromosome at the sbcB locus. At higher cell concentrations, transductants were also obtained with ETEC E4683, ETEC E8057 (insertion site unknown) and DAEC O75:H- E66438 (insertion site unknown) in LB broth and milk. It was concluded that the vtx2 gene may be transferred by bacteriophage to different E. coli pathotypes in laboratory and food matrices, resulting in the spread of the vtx2 gene and the emergence of novel foodborne pathogens.


Asunto(s)
Bacteriófagos/genética , Colifagos/fisiología , Escherichia coli/genética , Escherichia coli/virología , Lactuca/microbiología , Carne/microbiología , Leche/microbiología , Transducción Genética , Animales , Bacteriófagos/fisiología , Bovinos , Colifagos/genética , Escherichia coli/crecimiento & desarrollo , Escherichia coli/fisiología , Contaminación de Alimentos/análisis
17.
Food Microbiol ; 61: 50-57, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27697169

RESUMEN

The primary objective of this study was to characterise (microbiology and physical parameters) beef carcasses and primals during chilled storage. A minor aim was to compare observed growth of key spoilage bacteria on carcasses with that predicted by ComBase and the Food Safety Spoilage Predictor (FSSP). Total viable count (TVC), total Enterobacteriacae count (TEC), Pseudomonas spp., lactic acid bacteria (LAB), Brochothrix thermosphacta and Clostridium spp. were monitored on beef carcasses (n = 30) and primals (n = 105) during chilled storage using EC Decision 2001/471/EC and ISO sampling/laboratory procedures. The surface and/or core temperature, pH and water activity (aw) were also recorded. Clostridium (1.89 log10 cfu/cm2) and Pseudomonas spp. (2.12 log10 cfu/cm2) were initially the most prevalent bacteria on carcasses and primals, respectively. The shortest mean generation time (G) was observed on carcasses with Br. thermosphacta (20.3 h) and on primals with LAB (G = 68.8 h) and Clostridium spp. (G = 67 h). Over the course of the experiment the surface temperature decreased from 37 °C to 0 °C, pH from 7.07 to 5.65 and aw from 0.97 to 0.93 The observed Pseudomonas spp. and Br. thermosphacta growth was more or less within the range of predictions of Combase. In contrast, the FSSP completely overestimated the growth of LAB. This study contributes to the very limited microbiological data on beef carcasses and primals during chilling.


Asunto(s)
Embalaje de Alimentos , Almacenamiento de Alimentos , Carne Roja/microbiología , Temperatura , Animales , Brochothrix/crecimiento & desarrollo , Brochothrix/aislamiento & purificación , Bovinos , Microbiología de Alimentos , Conservación de Alimentos , Lactobacillaceae/crecimiento & desarrollo , Lactobacillaceae/aislamiento & purificación , Pseudomonas/crecimiento & desarrollo , Pseudomonas/aislamiento & purificación , Vacio
18.
Food Microbiol ; 62: 196-201, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27889148

RESUMEN

Two antimicrobial coatings, namely Sodium octanoate and Auranta FV (a commercial antimicrobial composed of bioflavonoids, citric, malic, lactic, and caprylic acids) were used. These two antimicrobials were surface coated onto the inner polyethylene layer of cold plasma treated polyamide films using beef gelatin as a carrier and coating polymer. This packaging material was then used to vacuum pack beef sub-primal cuts and stored at 4 °C. A control was prepared using the non-coated commercial laminate and the same vacuum packaged sub-primal beef cuts. During storage, microbial and quality assessments were carried out. Sodium octanoate treated packages significantly (p < 0.05) reduced microbial counts for all bacteria tested with an increase of 7 and 14 days, respectively compared to control samples. No significant effect on pH was observed with any treatment. The results suggested that these food grade antimicrobials have the potential to be used in antimicrobial active packaging applications for beef products.


Asunto(s)
Antiinfecciosos/química , Embalaje de Alimentos/métodos , Conservación de Alimentos , Plásticos , Animales , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Caprilatos/análisis , Caprilatos/química , Bovinos , Recuento de Colonia Microbiana , Microbiología de Alimentos , Almacenamiento de Alimentos/métodos , Gelatina/análisis , Gelatina/química , Gases em Plasma/química , Carne Roja/microbiología , Vacio
19.
J Sci Food Agric ; 97(3): 719-723, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27553887

RESUMEN

The process of anaerobic digestion (AD) is valued as a carbon-neutral energy source, while simultaneously treating organic waste, making it safer for disposal or use as a fertilizer on agricultural land. The AD process in many European nations, such as Germany, has grown from use of small, localized digesters to the operation of large-scale treatment facilities, which contribute significantly to national renewable energy quotas. However, these large AD plants are costly to run and demand intensive farming of energy crops for feedstock. Current policy in Germany has transitioned to support funding for smaller digesters, while also limiting the use of energy crops. AD within Ireland, as a new technology, is affected by ambiguous governmental policies concerning waste and energy. A clear governmental strategy supporting on-site AD processing of agricultural waste will significantly reduce Ireland's carbon footprint, improve the safety and bioavailability of agricultural waste, and provide an indigenous renewable energy source. © 2016 Society of Chemical Industry.


Asunto(s)
Fuentes de Energía Bioeléctrica , Bacterias Anaerobias Gramnegativas/metabolismo , Bacterias Grampositivas/metabolismo , Residuos Industriales , Política Pública , Energía Renovable , Fuentes de Energía Bioeléctrica/efectos adversos , Fuentes de Energía Bioeléctrica/historia , Fuentes de Energía Bioeléctrica/microbiología , Fuentes de Energía Bioeléctrica/normas , Huella de Carbono/economía , Huella de Carbono/legislación & jurisprudencia , Huella de Carbono/normas , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/historia , Conservación de los Recursos Naturales/legislación & jurisprudencia , Producción de Cultivos/economía , Productos Agrícolas/economía , Productos Agrícolas/crecimiento & desarrollo , Fermentación , Alemania , Bacterias Anaerobias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/crecimiento & desarrollo , Adhesión a Directriz/tendencias , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Residuos Industriales/economía , Irlanda , Política Pública/economía , Política Pública/historia , Política Pública/tendencias , Energía Renovable/efectos adversos , Energía Renovable/economía , Energía Renovable/historia , Energía Renovable/normas , Administración de la Seguridad/economía , Administración de la Seguridad/historia , Administración de la Seguridad/legislación & jurisprudencia , Administración de la Seguridad/normas
20.
Food Microbiol ; 48: 99-108, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25790997

RESUMEN

Despite over 30 years of research, campylobacteriosis is the most prevalent foodborne bacterial infection in many countries including in the European Union and the United States of America. However, relatively little is known about the virulence factors in Campylobacter or how an apparently fragile organism can survive in the food chain, often with enhanced pathogenicity. This review collates information on the virulence and survival determinants including motility, chemotaxis, adhesion, invasion, multidrug resistance, bile resistance and stress response factors. It discusses their function in transition through the food processing environment and human infection. In doing so it provides a fundamental understanding of Campylobacter, critical for improved diagnosis, surveillance and control.


Asunto(s)
Proteínas Bacterianas/metabolismo , Infecciones por Campylobacter/microbiología , Campylobacter/metabolismo , Factores de Virulencia/metabolismo , Animales , Proteínas Bacterianas/genética , Campylobacter/genética , Campylobacter/crecimiento & desarrollo , Campylobacter/patogenicidad , Humanos , Virulencia , Factores de Virulencia/genética
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