Advances in understanding the predominance, phenotypes, and mechanisms of bacteria related to meat spoilage

This study evaluated the high pressure inactivation of Campylobacter jejuni, Escherichia coli, and poultry meat spoilage organisms. All treatments were performed in aseptically prepared minced poultry meat. Treatment of 19 strains of C. jejuni at 300 MPa and 30°C revealed a large variation of pressure resistance. The recovery of pressure-induced sublethally injured C. jejuni depended on the availability of iron. The addition of iron content to enumeration media was required for resuscitation of sublethally injured cells. Survival of C. jejuni during storage of refrigerated poultry meat was analyzed in fresh and pressure-treated poultry meat, and in the presence or absence of spoilage microbiota. The presence of spoilage microbiota did not significantly influence the survival of C. jejuni. Pressure treatment at 400 MPa and 40°C reduced cell counts of Brochothrix thermosphacta, Carnobacterium divergens, C. jejuni, and Pseudomonas fluorescens to levels below the detection limit. Cell counts of E. coli AW1.7, however, were reduced by only 3.5 log (CFU/g) and remained stable during subsequent refrigerated storage. The resistance to treatment at 600 MPa and 40°Cof E. coli AW1.7 was compared with Salmonella enterica, Shiga toxin–producing E. coli and nonpathogenic E. coli strains, and Staphylococcus spp. Cell counts of all organisms except E. coli AW 1.7 were reduced by more than 6 log CFU/g. Cell counts of E. coli AW1.7 were reduced by 4.5 log CFU/g only. Moreover, the ability of E. coli AW1.7 to resist pressure was comparable to the pressure-resistant mutant E. coli LMM1030. Our results indicate that preservation of fresh meat requires a combination of high pressure with high temperature (40 to 60°C) or other antimicrobial hurdles.

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Neuro-fuzzy based identification of meat spoilage using an electronic nose

2016 IEEE 8th International Conference on Intelligent Systems (IS) ◽

10.1109/is.2016.7737406 ◽

2016 ◽

Author(s):

Vassilis S. Kodogiannis ◽

Abeer Alshejari

Keyword(s):

Electronic Nose ◽

Meat Spoilage ◽

Neuro Fuzzy

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Environmental reservoirs of psychrotrophic meat spoilage fungi

New Zealand Veterinary Journal ◽

10.1080/00480169.1977.34393 ◽

1977 ◽

Vol 25 (6) ◽

pp. 165-167 ◽

Cited By ~ 5

Author(s):

M. Baxter ◽

Gaylene M. Illston

Keyword(s):

Meat Spoilage ◽

Spoilage Fungi

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Role of Broiler Carcasses and Processing Plant Air in Contamination of Modified-Atmosphere-Packaged Broiler Products with Psychrotrophic Lactic Acid Bacteria

Applied and Environmental Microbiology ◽

10.1128/aem.01644-06 ◽

2006 ◽

Vol 73 (4) ◽

pp. 1136-1145 ◽

Cited By ~ 55

Author(s):

Elina Vihavainen ◽

Hanna-Saara Lundstrï¿½m ◽

Tuija Susiluoto ◽

Joanna Koort ◽

Lars Paulin ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

16S Rrna Genes ◽

Rrna Genes ◽

23S Rrna ◽

Processing Plant ◽

Modified Atmosphere ◽

Production Plant ◽

Meat Spoilage

ABSTRACT Some psychrotrophic lactic acid bacteria (LAB) are specific meat spoilage organisms in modified-atmosphere-packaged (MAP), cold-stored meat products. To determine if incoming broilers or the production plant environment is a source of spoilage LAB, a total of 86, 122, and 447 LAB isolates from broiler carcasses, production plant air, and MAP broiler products, respectively, were characterized using a library of HindIII restriction fragment length polymorphism (RFLP) patterns of the 16 and 23S rRNA genes as operational taxonomic units in numerical analyses. Six hundred thirteen LAB isolates from the total of 655 clustered in 29 groups considered to be species specific. Sixty-four percent of product isolates clustered either with Carnobacterium divergens or with Carnobacterium maltaromaticum type strains. The third major product-associated cluster (17% of isolates) was formed by unknown LAB. Representative strains from these three clusters were analyzed for the phylogeny of their 16S rRNA genes. This analysis verified that the two largest RFLP clusters consisted of carnobacteria and showed that the unknown LAB group consisted of Lactococcus spp. No product-associated LAB were detected in broiler carcasses sampled at the beginning of slaughter, whereas carnobacteria and lactococci, along with some other specific meat spoilage LAB, were recovered from processing plant air at many sites. This study reveals that incoming broiler chickens are not major sources of psychrotrophic spoilage LAB, whereas the detection of these organisms from the air of the processing environment highlights the role of processing facilities as sources of LAB contamination.

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Longitudinal metatranscriptomic analysis of a meat spoilage microbiome detects abundant continued fermentation and environmental stress responses during shelf life and beyond

10.1101/2020.08.13.250449 ◽

2020 ◽

Author(s):

Jenni Hultman ◽

Per Johansson ◽

Johanna Björkroth

Keyword(s):

Environmental Stress ◽

Shelf Life ◽

Stress Responses ◽

Pentose Phosphate ◽

Quality Analysis ◽

Microbial Succession ◽

Pronounced Difference ◽

Meat Spoilage ◽

Microbiological Methods ◽

16S Rna

AbstractMicrobial food spoilage is a complex phenomenon associated with the succession of the specific spoilage organisms (SSO) over the course of time. We performed a longitudinal metatranscriptomic study on a modified atmosphere packaged (MAP) beef product to increase understanding of the longitudinal behavior of a spoilage microbiome during shelf life and onward. Based on the annotation of the mRNA reads, we recognized three stages related to the active microbiome that were descriptive for the sensory quality of the beef: acceptable product (AP), early spoilage (ES) and late spoilage (LS). Both the 16S RNA taxonomic assignments from the total RNA and functional annotations of the active genes showed that these stages were significantly different from each other. However, the functional gene annotations showed more pronounced difference than the taxonomy assignments. Psychrotrophic lactic acid bacteria (LAB) formed the core of the SSO according to the transcribed reads. Leuconostoc species were the most abundant active LAB throughout the study period, whereas the activity of Streptococcaceae (mainly Lactococcus) increased after the product was spoiled. In the beginning of the experiment, the community managed environmental stress by cold-shock responses which were followed by the expression of the genes involved in managing oxidative stress. Glycolysis, pentose phosphate pathway and pyruvate metabolism were active throughout the study at a relatively stable level. However, the proportional activity of the enzymes in these pathways changed over time. For example, acetate kinase activity was characteristic for the AP stage whereas formate C-acetyltransferase transcription was associated with spoilage.ImportanceIt is generally known which organisms are the typical SSO in foods, whereas the actively transcribed genes and pathways during microbial succession are poorly understood. This knowledge is important since better approaches to food quality evaluation and shelf life determination are needed. Thus, we conducted this study to find longitudinal markers that are connected to quality deterioration. These kind of RNA markers could be used to develop novel type of rapid quality analysis tools in the future. New tools are needed since even though SSO can be detected and their concentrations determined using the current microbiological methods, results from these analyses cannot predict how close timewise a spoilage community is from production of clear sensory defects. Main reason for this is that the species composition of a spoilage community does not change dramatically during late shelf life, whereas the ongoing metabolic activities lead to the development of notable sensory deterioration.

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Autoinducer-2–like Activity in Lactic Acid Bacteria Isolated from Minced Beef Packaged under Modified Atmospheres

Journal of Food Protection ◽

10.4315/0362-028x.jfp-10-276 ◽

2011 ◽

Vol 74 (4) ◽

pp. 631-635 ◽

Cited By ~ 14

Author(s):

VASILIKI A. BLANA ◽

AGAPI I. DOULGERAKI ◽

GEORGE-JOHN E. NYCHAS

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Storage Temperature ◽

Inhibitory Effect ◽

Bacterial Strains ◽

Modified Atmospheres ◽

Autoinducer 2 ◽

Meat Spoilage ◽

Minced Beef ◽

Biosensor Strain

Fifteen fingerprints (assigned to Leuconostoc spp., Leuconostoc mesenteroides, Weissella viridescens, Leuconostoc citreum, and Lactobacillus sakei) of 89 lactic acid bacteria (LAB) isolated from minced beef stored under modified atmospheres at various temperatures were screened for their ability to exhibit autoinducer-2 (AI-2)–like activity under certain growth conditions. Cell-free meat extracts (CFME) were collected at the same time as the LAB isolates and tested for the presence of AI-2–like molecules. All bioassays were conducted using the Vibrio harveyi BAA-1117 (sensor 1−, sensor 2+) biosensor strain. The possible inhibitory effect of meat extracts on the activity of the biosensor strain was also evaluated. AI-2–like activity was observed for Leuconostoc spp. isolates, but none of the L. sakei strains produced detectable AI-2–like activity. The AI-2–like activity was evident mainly associated with the Leuconostoc sp. B 233 strain, which was the dominant isolate recovered from storage at 10 and 15°C and at the initial and middle stages of storage at chill temperatures (0 and 5°C). The tested CFME samples displayed low AI-2–like activity and inhibited AI-2 activity regardless of the indigenous bacterial populations. The LAB isolated during meat spoilage exhibited AI-2–like activity, whereas the LAB strains retrieved depended on storage time and temperature. The production of AI-2–like molecules may affect the dominance of different bacterial strains during storage. The results provide a basis for further research concerning the effect of storage temperature on the expression of genes encoding AI-2 activity and on the diversity of the ephemeral bacterial population.

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