Traceability of different brands of bottled mineral water during shelf life, using PCR-DGGE and next generation sequencing techniques.
In conclusion, no differences in total, viable and culturable bacteria counts were observed between mineral waters bottled with PET or glass during shelf life storage. Nevertheless, in spite of changes in the communities, each water brand and material presented a distinct microbial community structure clearly distinguishable from the others, which could be interesting for traceability purposes. PMID: 31027761 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Sala-Comorera L, Blanch AR, Casanovas-Massana A, Monleón-Getino A, García-Aljaro C Tags: Food Microbiol Source Type: research

Oxacillin-susceptible mecA-positive Staphylococcus aureus associated with processed food in Europe.
We report for the first time an oxacillin-susceptible mecA-positive Staphylococcus aureus (OS-MRSA) associated with a processed food product in Europe. One isolate (MRSA-ST5-type V SCCmec) was found in cheese among 600 food samples confiscated from air passengers from international flights in Vienna Airport (Austria). Type V SCCmec strains do not harbor functional mecI-mecR1 genes and in such strains mecA expression is regulated by the bla system (blaI-blaR1-blaZ). It has been recently reported that malfunctions in the bla system lead to the constitutive expression of mecA. The OS-MRSA reported in this study harbored the b...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Quijada NM, Hernández M, Oniciuc EA, Eiros JM, Fernández-Natal I, Wagner M, Rodríguez-Lázaro D Tags: Food Microbiol Source Type: research

Species identification and molecular characterization of Cronobacter spp. isolated from food imported over nine years into Beijing, China.
In conclusion, appropriate in-house database could make MALDI-TOF MS method identifying Cronobacter spp. isolates to the species level. But the spectra data were not sufficiently consistent for subtyping, unlike MLST. The Cronobacter spp. isolates have a high diversity including recognized pathovars. PMID: 31027763 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Wang Q, Forsythe SJ, Zhao XJ, Wang ZW, Li D, Ma D, Cao JY, Zeng J Tags: Food Microbiol Source Type: research

Potential of acidified sodium benzoate as an alternative wash solution of cherry tomatoes: Changes of quality, background microbes, and inoculated pathogens during storage at 4 and 21 °C post-washing.
Potential of acidified sodium benzoate as an alternative wash solution of cherry tomatoes: Changes of quality, background microbes, and inoculated pathogens during storage at 4 and 21°C post-washing. Food Microbiol. 2019 Sep;82:111-118 Authors: Chen H, Zhang Y, Zhong Q Abstract To evaluate the feasibility of acidified sodium benzoate (NaB) as alternative washing solutions of fresh produce, the survival of inoculated pathogens, the background molds and yeasts counts, and quality parameters were compared during 4 and 21 °C storage of cherry tomatoes washed with 3000 ppm NaB at pH 2.0, 200 ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Chen H, Zhang Y, Zhong Q Tags: Food Microbiol Source Type: research

Surveillance of norovirus contamination in commercial fresh/frozen berries from Heilongjiang Province, China, using a TaqMan real-time RT-PCR assay.
This study highlights the need for further risk surveillance for NoV contamination in berries produced in the Heilongjiang Province and recommends region-extended monitoring of retail berries for NoV. PMID: 31027765 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Gao X, Wang Z, Wang Y, Liu Z, Guan X, Ma Y, Zhou H, Jiang Y, Cui W, Wang L, Xu Y Tags: Food Microbiol Source Type: research

Effects of pulsed light and sanitizer wash combination on inactivation of Escherichia coli O157:H7, microbial loads and apparent quality of spinach leaves.
Abstract The purpose of this study was to investigate the efficacy of pulsed light (PL), a new formula of sanitizer (HEN) consisting of hydrogen peroxide, EDTA and Nisin, as well as synergy of PL and HEN sanitizer (PL-HEN) wash in inactivating E. coli O157:H7 on spinach. The treatment effect on microbial loads and apparent quality during 13 days storage at 4 °C was also determined. A bacterial cocktail containing three strains of E. coli O157:H7 was used as inoculum based on their association with produce-related outbreaks. Spinach leaves were spot inoculated on surface before treating with PL (1-63J/cm2), H...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Mukhopadhyay S, Sokorai K, Ukuku DO, Fan X, Olanya M, Juneja V Tags: Food Microbiol Source Type: research

Evaluation of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing.
Abstract Salmonella is capable of surviving in a low moisture environment for long periods. Once adapted to the xeric conditions, the thermal resistance of Salmonella is enhanced. Cocoa powder is a low water activity (aw) food (LawF) that is an essential component in a wide variety of desserts and ready-to-eat (RTE) foods and drinks. The aim of this study was to evaluate the desiccation and thermal resistance of Salmonella in cocoa powder, as well as to examine the suitability of Enterococcus faecium NRRL B-2354 as a surrogate for Salmonella during cocoa powder thermal processing. Natural unsweetened cocoa powder ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Tsai HC, Ballom KF, Xia S, Tang J, Marks BP, Zhu MJ Tags: Food Microbiol Source Type: research

Effects of the colonization sequence of Listeria monocytogenes and Pseudomonas fluorescens on survival of biofilm cells under food-related stresses and transfer to salmon.
This study evaluated how the colonization sequence of Listeria monocytogenes and Pseudomonas fluorescens affects biofilm formation and biofilm cell response to food-related stress (desiccation or disinfection) as well as the transferability of L. monocytogenes to salmon products. The results showed that the colonization sequence did not affect the population of dual species biofilms. Furthermore, survival number of L. monocytogenes was 0.8 log CFU/cm2 higher when P. fluorescens was the first colonizer during desiccation or disinfectant treatment in comparison with dual-species biofilms with other colonization sequences. A ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Pang X, Yuk HG Tags: Food Microbiol Source Type: research

Aroma formation in retentostat co-cultures of Lactococcus lactis and Leuconostoc mesenteroides.
This study provides insights in the production of cheese aroma compounds outside the cheese matrix by co-cultures of L. lactis and Lc. mesenteroides, which could be used as food supplements in dairy or non-dairy products. PMID: 31027769 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: van Mastrigt O, Egas RA, Abee T, Smid EJ Tags: Food Microbiol Source Type: research

Selection of Algerian lactic acid bacteria for use as antifungal bioprotective cultures and application in dairy and bakery products.
Abstract In the context of a demand for "preservative-free" food products, biopreservation appears as a promising alternative to either replace or reduce the use of chemical preservatives. The purpose of this study was to evaluate the antifungal activity of a collection of lactic acid bacteria (n = 194), and then to evaluate the applicability and efficacy of selected ones used as bioprotective cultures against mold spoilers in dairy and bakery products. First, lactic acid bacteria were isolated from various Algerian raw milk samples and Amoredj, a traditional fermented product. Secondly, in vitro scr...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Ouiddir M, Bettache G, Leyva Salas M, Pawtowski A, Donot C, Brahimi S, Mabrouk K, Coton E, Mounier J Tags: Food Microbiol Source Type: research

Effect of 222-nm krypton-chloride excilamp treatment on inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium on alfalfa seeds and seed germination.
We examined the control effect of a 222-nm KrCl excilamp on foodborne pathogens on alfalfa seeds and compared it with a conventional 254-nm low-pressure (LP) Hg lamp. When the 222-nm KrCl excilamp treated seeds at 87, 174 and 261 mJ/cm2, the log reductions of Escherichia coli O157:H7 (E. coli O157:H7) were 0.85, 1.77, and 2.77, respectively, and Salmonella Typhimurium (S. Typhimurium) experienced log reductions of 1.22, 2.27, and 3.04, respectively. When the 254-nm LP Hg lamp was applied at 87, 174, and 261 mJ/cm2, the log reductions of E. coli O157: H7 were 0.7, 1.16, and 1.43, respectively, and those of S. Typhimuriu...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Kang JW, Lee JI, Jeong SY, Kim YM, Kang DH Tags: Food Microbiol Source Type: research

Proteomic analysis of the food spoiler Pseudomonas fluorescens ITEM 17298 reveals the antibiofilm activity of the pepsin-digested bovine lactoferrin.
In conclusion, in this work protein determinats of biofilm formation were revelead in ITEM 17298 under the low temperature; the synthesis of these latter were inhibited by HLF confirming its possible exploitation as antibiofilm agent for biotechnological applications in cold stored foods. PMID: 31027772 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Quintieri L, Zühlke D, Fanelli F, Caputo L, Liuzzi VC, Logrieco AF, Hirschfeld C, Becher D, Riedel K Tags: Food Microbiol Source Type: research

Quantification and genetic diversity of Hepatitis E virus in wild boar (Sus scrofa) hunted for domestic consumption in Central Italy.
This study assessed HEV occurrence, viral load and genetic variability in wild boar hunted for domestic consumption in the district of Viterbo (Central Italy) where high anti-HEV IgG seroprevalence values are reported in humans. A total of 332 liver and 69 intestine samples were obtained from wild boar hunted between 2011 and 2014. The liver tissue in 54 of the animals (16.3%) was HEV-positive. Viral loads in quantifiable liver samples (n = 29) ranged between 3.2 × 102 and 3.8 × 105 genome copies (g.c.)/g with a mean value of 1.85 × 104 g.c./g. A statistically significant positive correlat...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Di Pasquale S, De Santis P, La Rosa G, Di Domenico K, Iaconelli M, Micarelli G, Martini E, Bilei S, De Medici D, Suffredini E Tags: Food Microbiol Source Type: research

Mentha piperita L. essential oil inactivates spoilage yeasts in fruit juices through the perturbation of different physiological functions in yeast cells.
This study evaluated the efficacy of the essential oil from Mentha piperita L. (MPEO) to inactivate cells of the potentially spoilage yeasts Candida albicans, Candida tropicalis, Pichia anomala and Saccharomyces cerevisiae in cashew, guava, mango and pineapple juices during 72 h of refrigerated storage. Damage in different physiological functions caused by MPEO in S. cerevisiae in cashew and guava juices were investigated using flow cytometry (FC). The effects of the incorporation of an effective anti-yeast MPEO dose on sensory characteristics of juices were also evaluated. MPEO displayed minimum inhibitory concentration...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Almeida ETDC, de Souza GT, de Sousa Guedes JP, Barbosa IM, de Sousa CP, Castellano LRC, Magnani M, de Souza EL Tags: Food Microbiol Source Type: research

Antiviral effects of blueberry proanthocyanidins against Aichi virus.
This study aimed to (1) determine the time- and dose-dependent effects of blueberry proanthocyanidins (B-PAC) against AiV over 24 h at 37 °C; (2) gain insights on their mode of action using pre- and post-treatment of host cells and Transmission Electron Microscopy; and (3) determine their anti-AiV effects in model foods and under simulated gastric conditions. AiV at ∼5 log PFU/ml was incubated with equal volumes of commercial blueberry juice (BJ, pH 2.8), neutralized BJ (pH 7.0), B-PAC (2, 4, and 10 mg/ml) prepared either in 10% ethanol, apple juice (AJ), 2% milk, simulated gastric fluid (SGF, pH 1.5) or simu...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Joshi SS, Howell AB, D'Souza DH Tags: Food Microbiol Source Type: research

Bacterial spoilage profiles in the gills of Pacific oysters (Crassostrea gigas) and Eastern oysters (C. virginica) during refrigerated storage.
In this study, the microbial activities and pH changes of the gills of the two species, Crassostrea gigas and C. virginica, harvested from three different sites were determined and sensory evaluation was conducted during refrigerated storage. The bacteria in gills with an initial aerobic plate count (APC) of 3.1-4.5 log CFU/g rose remarkably to 7.8-8.8 log CFU/g after 8-days of storage. The APC of Enterobacteriaceae increased from 2.5 to 3.6 log CFU/g to 4.5-4.8 log CFU/g, and that of lactic acid bacteria (LAB) fluctuated in the range of 1.4-3.0 log CFU/g during the whole storage period. The results of sensory analysis ind...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Chen H, Wang M, Yang C, Wan X, Ding HH, Shi Y, Zhao C Tags: Food Microbiol Source Type: research

Novel solid-state fermentation of bee-collected pollen emulating the natural fermentation process of bee bread.
Abstract Structure of lactic acid bacteria biota in ivy flowers, fresh bee-collected pollen (BCP), hive-stored bee bread, and honeybee gastrointestinal tract was investigated. Although a large microbial diversity characterized flowers and fresh BCP, most of lactic acid bacteria species disappeared throughout the bee bread maturation, giving way to Lactobacillus kunkeei and Fructobacillus fructosus to dominate long stored bee bread and honeybee crop. Adaptation of lactic acid bacteria was mainly related to species-specific, and, more in deep, to strain-specific features. Bee bread preservation seemed related to bac...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Di Cagno R, Filannino P, Cantatore V, Gobbetti M Tags: Food Microbiol Source Type: research

Characterization of plant lectins for their ability to isolate Mycobacterium avium subsp. paratuberculosis from milk.
Deeg CA PMID: 31027778 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Hobmaier BF, Lutterberg K, Kleinwort KJH, Mayer R, Hirmer S, Amann B, Hölzel C, Märtlbauer EP, Deeg CA Tags: Food Microbiol Source Type: research

Significance of Aspergillus niger aggregate species as contaminants of food products in Spain regarding their occurrence and their ability to produce mycotoxins.
lez-Jaén MT, Patiño B Abstract The Aspergillus niger aggregate contains 15 morphologically indistinguishable species which presence is related to ochratoxin A (OTA) and fumonisin B2 (FB2) contamination of foodstuffs. The taxonomy of this group was recently reevaluated and there is a need of new studies regarding the risk that these species might pose to food security. 258 isolates of A. niger aggregate obtained from a variety of products from Spain were classified by molecular methods being A. tubingensis the most frequently occurring (67.5%) followed by A. welwitschiae (19.4%) and A. niger (11.7%). ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Gil-Serna J, García-Díaz M, Vázquez C, González-Jaén MT, Patiño B Tags: Food Microbiol Source Type: research

The evaluation of gamma irradiation and cold storage for the reduction of Campylobacter jejuni in chicken livers.
In this study, gamma irradiation is evaluated for its effectiveness in reducing Campylobacter jejuni numbers in experimentally contaminated chicken livers. A wide range of radiation doses were evaluated in conjunction with cold storage parameters, before and after irradiation. Storage of chicken livers at -20 °C prior to radiation treatment, as expected, increased C. jejuni radiation resistance. Livers previously stored at -20 °C exhibited D10 values of 0.748 kiloGray (kGy) compared to livers without previous storage that had a significantly lower D10 value of 0.361 kGy. Cold storage conditions post-irradiati...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Gunther NW, Abdul-Wakeel A, Scullen OJ, Sommers C Tags: Food Microbiol Source Type: research

Characterization of Arcobacter spp. isolated from retail seafood in Germany.
This study aimed to evaluate the presence of Arcobacter in retail seafood and characterize Arcobacter isolates derived from these matrices. In total, seven species of Arcobacter were isolated from 56 of 318 (17.6%) seafood samples, including bivalves (mussels, clams and razor clams), shrimps and cephalopods (squids and octopuses). The highest prevalence was detected in cephalopods (27.4%), followed by bivalves (18%) and lowest in shrimps (8.5%). PCRs of 10 putative virulence genes demonstrated higher prevalences of these genes among A. butzleri, compared to other species, such as A. cryaerophilus, A. aquimarinus and A. ven...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Zhang X, Alter T, Gölz G Tags: Food Microbiol Source Type: research

Microbial biogeography of Spanish-style green olive fermentations in the province of Seville, Spain.
ba JL Abstract The aim of this study is to examine the biogeography of the microbial communities associated to the Spanish-style green olive fermentations in the province of Seville (Andalucía, south-western Spain). Also, to understand how microorganisms colonize and persist in non-sterile food fermentations across a specific table olive producing area, i.e. a specific "agroecosystem". The microbial diversity, bacteria and yeast, in 30 ten-ton fermenters of three different fermentations yards (patios) along the olive fermentation was studied. A total of 951 microbial isolates were obtained which w...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Lucena-Padrós H, Ruiz-Barba JL Tags: Food Microbiol Source Type: research

Biocontrol of aflatoxigenic Aspergillus parasiticus by native Debaryomyces hansenii in dry-cured meat products.
cute;ñez F Abstract Dry-cured meat products, such as dry-cured ham or dry-fermented sausages, are characterized by their particular ripening process, where a mould population grows on their surface. Some of these moulds are hazardous to the consumers because of their ability to produce mycotoxins including aflatoxins (AFs). The use of native yeasts could be considered a potential strategy for controlling the presence of AFs in dry-cured meat products. The aim of this work was to evaluate the antagonistic activity of two native Debaryomyces hansenii strains on the relative growth rate and the AFs production ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Peromingo B, Andrade MJ, Delgado J, Sánchez-Montero L, Núñez F Tags: Food Microbiol Source Type: research

Application of colony BOXA2R-PCR for the differentiation and identification of lactic acid COCCI.
In this study, it was demonstrated that BOXA2R-PCR could effectively discriminate between Lactococcus lactis, Leuconostoc mesenteroides and Streptococcus thermophilus; differentiate Lactococcus lactis strains and subspeciate them into lactis and cremoris in a single reaction; generate unique strain fingerprints of various lactic acid bacteria (LAB species) commonly isolated from fermented dairy products, including occasional spoilage bacteria and yeasts. Furthermore, using direct colony PCR a reproducible and rapid method was developed for the differentiation and identification of lactic acid cocci. The simplicity and spee...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Damnjanovic D, Harvey M, Bridge WJ Tags: Food Microbiol Source Type: research

MRSA in swine, farmers and abattoir workers in Southern Italy.
In this study, MRSA strains were isolated from 55 of the 85 (64.7%) intensive pig farms surveyed, and prevalence was greater on pig fattening farms than on breeding farms. In addition, we included in the study 63 foreign pigs imported for slaughter. Overall, the prevalence of MRSA in the 418 sampled swine was 59.1%; 12 genotypes were identified among the isolates; ST398 (96.4%) was most prevalent, followed by ST97 (2%), ST9 (0.8%) and ST1 (0.8%). MRSA isolates were also detected in 26 (17.3%) of the 150 operators included in the study; the genotypes detected were ST398 (85%), ST9 (7.6%), ST5 (3.8%) and ST1 (3.8%). All the ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Parisi A, Caruso M, Normanno G, Latorre L, Miccolupo A, Fraccalvieri R, Intini F, Manginelli T, Santagada G Tags: Food Microbiol Source Type: research

Effect of different starter cultures on chemical and microbial parameters of buckwheat honey fermentation.
ayo B Abstract The aim of this study was to analyze the microbiology of buckwheat honey fermentation inoculated with different starter cultures by culturing and PCR-DGGE, taking as a model for comparison a spontaneously fermented batch. The inoculants tested were (i) cider lees (from a cider factory), (ii) sourdough (from a bakery), and (iii) a commercial Saccharomyces cerevisiae strain. The results of the culturing and culture-independent techniques agreed well and detected the same dominant species along the fermentations. Our results suggest that S. cerevisiae strains, which constituted a majority population in...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Bednarek M, Szwengiel A, Flórez AB, Czarnecki Z, Mayo B Tags: Food Microbiol Source Type: research

Lactococcus lactis subsp. lactis as a natural anti-listerial agent in the mushroom industry.
Abstract Mushroom growth substrates from different commercial producers of mushrooms (Agaricus bisporus) were screened for the presence of bacteria with potential for use as biocontrol agents for controlling Listeria monocytogenes in the mushroom production environment. Eight anti-listerial strains were isolated from different sources and all were identified using 16s rRNA gene sequencing as Lactococcus lactis subsp. lactis. Whole-genome sequencing of the Lc. lactis isolates indicated that strains from different sites and substrate types were highly similar. Colony MALDI-TOF mass spectrometry found that these stra...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Dygico LK, O'Connor PM, Hayes M, Gahan CGM, Grogan H, Burgess CM Tags: Food Microbiol Source Type: research

Comparative stress response to food preservation conditions of ST19 and ST213 genotypes of Salmonella enterica serotype Typhimurium.
ázquez-Marrufo G Abstract The replacement of the most prevalent Salmonella enterica genotypes has been documented worldwide. Here we tested the hypothesis that the current prevalent sequence type ST213 of serotype Typhimurium in Mexico has a higher resistance to stressful food preservation conditions than the displaced sequence ST19. ST19 showed higher cell viability percentages than ST213 in osmotic (685 mM NaCl) and acidic (pH 3.5) stress conditions and in combination with refrigeration (4 °C) and ambient (≈22 °C) temperatures. Both genotypes showed the same poststress recovery growth....
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Gómez-Baltazar A, Vázquez-Garcidueñas MS, Larsen J, Kuk-Soberanis ME, Vázquez-Marrufo G Tags: Food Microbiol Source Type: research

Adaptation of Bacillus species to dairy associated environment facilitates their biofilm forming ability.
In this study, we sequenced and analyzed the genomes of milk- and non-milk-derived Bacillus strains, and evaluated their biofilm-formation potential in milk. Unlike non-dairy Bacillus isolates, the dairy-associated Bacillus strains were characterized by formation of robust submerged and air-liquid interface biofilm (pellicle) during growth in milk. Moreover, genome comparison analysis revealed notable differences in putative biofilm-associated determinants between the dairy and non-dairy Bacillus isolates, which correlated with biofilm phenotype. These results suggest that biofilm formation by Bacillus species might repres...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Ostrov I, Sela N, Belausov E, Steinberg D, Shemesh M Tags: Food Microbiol Source Type: research

Bacterial communities and potential spoilage markers of whole blue crab (Callinectes sapidus) stored under commercial simulated conditions.
Abstract Bacterial communities composition using 16S Next Generation Sequencing (NGS) and Volatile Organic Compounds (VOCs) profile of whole blue crabs (Callinectes sapidus) stored at 4 and 10 °C (proper and abuse temperature) simulating real storage conditions were performed. Conventional microbiological and chemical analyses (Total Volatile Base-Nitrogen/TVB-N and Trimethylamine-Nitrogen/TMA-N) were also carried out. The rejection time point was 10 and 6 days for the whole crabs stored at 4 and 10 °C, respectively, as determined by development of unpleasant odors, which coincided with crabs death. In...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Parlapani FF, Michailidou S, Anagnostopoulos DA, Koromilas S, Kios K, Pasentsis K, Psomopoulos F, Argiriou A, Haroutounian SA, Boziaris IS Tags: Food Microbiol Source Type: research

Evaluation of thermal inactivation parameters of Salmonella in whole wheat multigrain bread.
This study was conducted to validate a simulated commercial whole wheat multigrain bread baking process at 375 °F (190.6 °C) oven temperature for 35 min to inactivate Salmonella, and to determine the thermal inactivation parameters of a 7-serovar Salmonella cocktail in whole wheat multigrain bread dough. A ≥5-log CFU/g reduction in Salmonella population was achieved by 15 min, and no viable Salmonella was detected after enrichment plating by 16 min. The aw of the bread crumb (0.96) after baking and 60 min of cooling was similar to that of pre-baked bread dough, whereas the aw of bread crust decreased...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Channaiah LH, Michael M, Acuff JC, Phebus RK, Thippareddi H, Milliken G Tags: Food Microbiol Source Type: research

Combination effect of saturated or superheated steam and lactic acid on the inactivation of Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes on cantaloupe surfaces.
Abstract The purpose of this study was to evaluate the effectiveness of the combination treatment of lactic acid immersion and saturated or superheated steam (SHS) on inactivation of foodborne pathogens on cantaloupes. Saturated steam (SS) treatments were performed at 100 °C, while SHS treatments were delivered at either 150 or 200 °C. Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes-inoculated cantaloupes were exposed to 2% lactic acid or sterile distilled water for 1 min followed by a maximum of 20 s of SS or SHS. Populations of each of the three pathogens on cantaloupe...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Kwon SA, Song WJ, Kang DH Tags: Food Microbiol Source Type: research

Microbial shifts in Minas artisanal cheeses from the Serra do Salitre region of Minas Gerais, Brazil throughout ripening time.
This study aimed to assess the bacterial community of raw milk, endogenous starter culture and to uncover possible shifts in the bacterial community of the rind and core of cheeses at sixty days of ripening located in the Serra do Salitre region by Illumina MiSeq 16S rRNA gene amplicon sequencing. Raw milk and starter culture are responsible for inoculating specific bacteria into the cheese, with Planococcaceae and Streptococcaceae being prevalent throughout ripening time. The Planococcaceae family seems to develop strong interactions with the Leuconostocaceae family on the surface of these cheeses, and is associated with ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Sant'Anna FM, Wetzels SU, Cicco SHS, Figueiredo RC, Sales GA, Figueiredo NC, Nunes CA, Schmitz-Esser S, Mann E, Wagner M, Souza MR Tags: Food Microbiol Source Type: research

Mechanism of inactivation of Bacillus subtilis spores by high pressure CO2 at high temperature.
Abstract Spores of wild-type Bacillus subtilis and some isogenic mutant strains were treated by high pressure CO2 (HPCD) at high temperature (HT) (HPCD + HT) at 20 MPa and 84-86 °C for 0-60 min, and centrifuged on a high density solution to obtain pelleted spores that retained CaDPA and light spores that lost CaDPA. All treated spores were analyzed for viability, and tested for germination, outgrowth, core protein damage, mutagenesis and inner membrane (IM) properties. The results showed that (i) with HPCD + HT treated spores, most pelleted spores and all light spores were de...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Rao L, Zhao L, Wang Y, Chen F, Hu X, Setlow P, Liao X Tags: Food Microbiol Source Type: research

Persistence of foodborne diarrheagenic Escherichia coli in the agricultural and food production environment: Implications for food safety and public health.
Abstract Diarrheagenic Escherichia coli (DEC) is a leading cause of foodborne illness associated with intestinal disease. While known over the years that contamination of food sources occurs via the oral faecal-route, the mechanisms underlying its persistence within the open environments including the food chain remains virtually unknown. Therefore, in this mini-review we will shed light on bacterial processes such as initial attachment, biofilm formation, horizontal gene transfer and response to environmental stresses. These factors may enable persistence of DEC as well as the emergence of potentially more virule...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Aijuka M, Buys EM Tags: Food Microbiol Source Type: research

Microbial quality of raw and ready-to-eat mung bean sprouts produced in Italy.
Abstract The aim of this study was to determine the microbial quality of mung bean sprouts produced in Italy. The presence of pathogenic microorganisms (Shiga toxin-producing Escherichia coli (STEC), Salmonella spp. and Listeria monocytogenes), total coliforms, and total viable counts (TVCs) were determined. The study covered five years of sprout production. The results demonstrated that no pathogenic microorganisms were present, and the microbial load was less than 6 log CFU/g. The mung bean sprouts currently produced in Italy were found to be acceptable for consumption. An additional aim was to determine the fat...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Iacumin L, Comi G Tags: Food Microbiol Source Type: research

Transcriptomic response of Escherichia coli O157 isolates on meat: Comparison between a typical Australian isolate from cattle and a pathogenic clinical isolate.
In this study, RNA-Seq experiments were undertaken with E. coli O157 to identify genes that may be associated with growth and survival on meat and the beef carcass at low temperature. In addition, the response of an E. coli O157 isolate representative of the general genetic 'type' found in Australia (E. coli O157:H- strain EC2422) was compared to that of a pathogenic clinical isolate (E. coli O157:H7 strain Sakai) not typically found in Australia. Both strains up-regulated genes involved in the acid stress response, cold shock response, quorum sensing, biofilm formation and Shiga toxin production. Differences were also obs...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: King T, Vockler CJ, Allnutt TR, Fegan N Tags: Food Microbiol Source Type: research

Radiofrequency pasteurization process for inactivation of Salmonella spp. and Enterococcus faecium NRRL B-2354 on ground black pepper.
In this study, radiofrequency (RF) processing was evaluated for pasteurization of ground black pepper. Stability and homogeneity tests were done for both Salmonella spp. and E. faecium during moisture equilibration before RF heating to evaluate the inoculation method. Moisture content of samples were conditioned such that the final moisture content after RF heating reached the optimal storage moisture. RF heating was shown to provide more than 5.98 log CFU/g reduction for Salmonella spp. and the reduction of 3.89 log CFU/g for E. faecium with a 130 s of treatment time. The higher thermal resistance of E. faecium indicate...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Wei X, Lau SK, Stratton J, Irmak S, Subbiah J Tags: Food Microbiol Source Type: research

An organoleptic survey of meads made with lactic acid-producing yeasts.
In this study, we utilized 13 LAY strains to produce semi-sweet meads using a standardized batch of honey must to ensure consistent starting conditions. Thirteen 11-L batches of mead were prepared, and each was inoculated with one of the LAY strains, along with two control batches inoculated with champagne yeast. The initial pH and specific gravity were measured for each batch before inoculation. Traditional organic staggered nutrient addition was utilized for the first 72 h of fermentation with specific gravities being taken throughout the mead making process. Meads were racked, tasted, stabilized, cold crashed, bottled...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Peepall C, Nickens DG, Vinciguerra J, Bochman ML Tags: Food Microbiol Source Type: research

Inactivation of Bacillus subtilis spores at various germination and outgrowth stages using intense pulsed light.
This study evaluated the inactivation effects of IPL at various fluences on Bacillus subtilis spores. IPL treatment at a total fluence of 7.40 J/cm2 resulted in a 7 log reduction, indicating the potential of IPL to effectively inactivate bacterial spores. The sensitivity of B. subtilis spores to IPL during germination and outgrowth was also measured. The resistance to the IPL increased temporarily until 1 h after the start of incubation, and then gradually decreased for longer incubation periods. This temporary increase in resistance at the early stage of incubation was attributed to the leakage of dipicolinic acid fro...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Jo HL, Hwang HJ, Chung MS Tags: Food Microbiol Source Type: research

Transcription activity of lactic acid bacterial proteolysis-related genes during cheese maturation.
M, Koreňová J, Budiš J, Kuchta T Abstract The catabolism of milk protein in cheese is one way how the microorganisms influence the sensorial characteristics of the final product. In this investigation, we paid attention to four genes [prtP (cell-envelope proteinase gene), pepX (X-prolyl dipeptidyl aminopeptidase gene), pepN (aminopeptidase gene) and bcaT (branched chain aminotransferase gene)] responsible for the production of volatile aroma-active compounds from milk proteins by lactic acid bacteria (LAB). We studied the dynamics of these genes and their corresponding LAB host, during the maturatio...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Pangallo D, Kraková L, Puškárová A, Šoltys K, Bučková M, Koreňová J, Budiš J, Kuchta T Tags: Food Microbiol Source Type: research

Transcriptome sequencing reveals genes and adaptation pathways in Salmonella Typhimurium inoculated in four low water activity foods.
Abstract Salmonella enterica serotypes have been reported as the agent of various outbreaks occurred after the consumption of low water activity (aw) foods. When the pathogen encounters harsh conditions, several regulatory networks are activated through dynamic differential gene expression that lead to cell survival for prolonged periods. In this work, the transcriptome of S. enterica serovar Typhimurium using RNA-Seq, after cells' inoculation in four distinct types of low aw foods (milk chocolate, powdered milk, black pepper, and dried pet food), following storage at 25 °C per 24 and 72 h was studied. The...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Crucello A, Furtado MM, Chaves MDR, Sant'Ana AS Tags: Food Microbiol Source Type: research

Stochastic modeling of variability in survival behavior of Bacillus simplex spore population during isothermal inactivation at the single cell level using a Monte Carlo simulation.
Abstract The control of bacterial reduction is important to maintain food safety during thermal processing. The goal of this study was to illustrate and describe variability in bacterial population behavior during thermal processing as a probability distribution based on individual cell heterogeneity regarding heat resistance. Toward this end, we performed a Monte Carlo simulation via computer, and compared and validated the simulated estimations with observed values. Weibullian fitted parameters were estimated from the kinetic survival data of Bacillus simplex during thermal treatment at 94 °C. The variabil...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Abe H, Koyama K, Kawamura S, Koseki S Tags: Food Microbiol Source Type: research

Effects of pomegranate peel extract on quality and microbiota composition of bighead carp (Aristichthys nobilis) fillets during chilled storage.
This study aimed to investigate effects of aqueous pomegranate peel extract (APPE) and ethanolic pomegranate peel extract (EPPE) on microbiota and changes in quality of bighead carp (Aristichthys nobilis) fillets stored at 4 °C. The results showed that pomegranate peel extract (PPE, which includes both APPE and EPPE) retarded the deterioration of sensory quality and flesh color, inhibited the growth of spoilage bacteria, and attenuated the production of biogenic amines, total volatile basic nitrogen (TVB-N), and the degradation of ATP-related compounds. Moreover, EPPE performed better in color attributes and biogenic...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Zhuang S, Li Y, Jia S, Hong H, Liu Y, Luo Y Tags: Food Microbiol Source Type: research

Processing plant and machinery sanitation and hygiene practices associate with Listeria monocytogenes occurrence in ready-to-eat fish products.
We examined the association of fish-processing plant operational and hygiene practices with the occurrence of L. monocytogenes in vacuum-packaged gravad (cold-salted) and cold-smoked salmon and rainbow trout products. Product sampling of 21 fish-processing plants was carried out, and operational procedures relating to L. monocytogenes control were surveyed using an in-depth risk assessment questionnaire. L. monocytogenes occurred only in sliced and mainly in gravad products of seven fish-processing plants. Shortages in preventive measures were discovered predominantly among the L. monocytogenes positive fish-processing pla...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Aalto-Araneda M, Lundén J, Markkula A, Hakola S, Korkeala H Tags: Food Microbiol Source Type: research

Transcriptional profiling and metabolomic analysis of Staphylococcus aureus grown on autoclaved chicken breast.
Abstract Although Staphylococcus aureus is a major cause of food poisoning, little is known about its response to growth on food. Utilizing a transcriptional profiling and metabolomics approach, we compared S. aureus grown on autoclaved chicken breast (ACB) to Luria broth agar. ACB cultures demonstrated increased expression of genes associated with protein synthesis, cofactors, secondary metabolites, nitrogen and nucleotide metabolism, amino acid transport, and reduced expression of general stress, lipid metabolism, and virulence genes. The ACB culture also displayed characteristics of catabolite de-repression and...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Dupre JM, Johnson WL, Ulanov AV, Li Z, Wilkinson BJ, Gustafson JE Tags: Food Microbiol Source Type: research

Tetragenococcus halophilus MJ4 as a starter culture for repressing biogenic amine (cadaverine) formation during saeu-jeot (salted shrimp) fermentation.
This study suggests that the use of strain MJ4 as a starter culture in salted fish fermentation may be a good strategy for the reduction of BA formation. PMID: 31027807 [PubMed - in process] (Source: Food Microbiology)
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Kim KH, Lee SH, Chun BH, Jeong SE, Jeon CO Tags: Food Microbiol Source Type: research

Bacteriological analysis of wheat flour associated with an outbreak of Shiga toxin-producing Escherichia coli O121.
Abstract A 2016/2017 outbreak of Shiga toxin-producing Escherichia coli (STEC) O121 in Canada, was linked to wheat flour, milled at a single facility on three consecutive days in October 2016. Most Probable Number (MPN) estimates of the concentration of STEC O121 in the recalled flour were made using the results of qualitative testing conducted during the outbreak investigation and from analysis of 5 × 2.5 g, 5 × 25 g and 5 × 100 g analytical units of the recalled flour. The STEC O121 levels were estimated at 0.15 to 0.43 MPN/100 g, with no significant difference between produ...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Gill A, Carrillo C, Hadley M, Kenwell R, Chui L Tags: Food Microbiol Source Type: research

Curli fimbriae confer shiga toxin-producing Escherichia coli a competitive trait in mixed biofilms.
Abstract Shiga toxin-producing Escherichia coli (STEC) is one of the most common causal agents of foodborne illness linked to fresh leafy vegetables. Here, we investigated the impact of spinach-associated microorganisms on proliferation and biofilm formation of STEC O157:H7 on stainless steel surfaces at temperatures related to produce production and postharvest processing environments. Although a proliferation of inoculated pathogen cells in spinach leaf wash water was detected at all temperatures examined, the impact of spinach-associated microorganisms on the proliferation of E. coli O157:H7 was observed at 10...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Carter MQ, Feng D, Li HH Tags: Food Microbiol Source Type: research

Evolution of Campylobacter jejuni of poultry origin in Brazil.
In this study, we evaluated the virulence, antibiotic resistance and genetic diversity profiles of 99 C. jejuni isolated from chilled chicken carcasses collected in Brazilian slaughterhouses during two distinct periods (2011-2012 and 2015-2016). The virulence profile was evaluated for the presence of flaA, ciaB, cadF, pldA and cdtABC genes. Antibiotic resistance was evaluated for amoxicillin-clavulanic acid, gentamicin, erythromycin and tetracycline. Genetic diversity was assessed using RAPD-PCR. The prevalence of C. jejuni was significantly reduced in 2015-2016 as well the number of antibiotic (and multidrug) resistant is...
Source: Food Microbiology - April 29, 2019 Category: Food Science Authors: Melo RT, Grazziotin AL, Júnior ECV, Prado RR, Mendonça EP, Monteiro GP, Peres PABM, Rossi DA Tags: Food Microbiol Source Type: research