Methods and protocols in food science, Journal Year: 2023, Volume and Issue: unknown, P. 47 - 64
Published: Jan. 1, 2023
Language: Английский
International Journal of Food Microbiology, Journal Year: 2023, Volume and Issue: 394, P. 110165 - 110165
Published: March 11, 2023
Listeria monocytogenes is a pathogenic bacterium that can inhabit diverse range of environmental niches. This largely attributed to the high proportion carbohydrate-specific phosphotransferase system (PTS) genes in its genome. Carbohydrates be assimilated as sources energy but additionally they serve niche-specific cues for L. shape global gene expression, order cope with anticipated stresses. To examine carbon source utilization among wild isolates and understand underlying molecular mechanisms, collection strains (n = 168) whole genome sequence (WGS) data available was screened ability grow chemically defined media different sources. The majority grew glucose, mannose, fructose, cellobiose, glycerol, trehalose, sucrose. Maltose, lactose, rhamnose supported slower growth while ribose did not support any growth. In contrast other strains, strain1386, which belonged clonal complex 5 (CC5), unable on trehalose sole source. WGS revealed it carried substitution (N352K) putative PTS EIIBC transporter, TreB, this asparagine residue conserved collection. Spontaneous mutants strain 1386 could were found harbour reversion TreB. These results provide genetic evidence TreB responsible uptake N352 essential activity. Moreover, also restored unusual phenotypes displayed, i.e. altered colony morphology, impaired biofilm development, reduced acid resistance. Transcriptional analysis at stationary phase buffered BHI metabolism positively influences transcription encoding amino acid-based resistance mechanisms. summary, our demonstrated key function transporter suggest alters physiology favour development stress since recommended by European Union Reference Laboratory conducting food challenge studies determine whether or food, these findings have important implications safety.
Language: Английский
Citations
17
Frontiers in Microbiology, Journal Year: 2024, Volume and Issue: 15
Published: March 22, 2024
Listeria monocytogenes is a foodborne pathogen of concern in dairy processing facilities, with the potential to cause human illness and trigger regulatory actions if found product. Monitoring for spp. through environmental sampling recommended prevent establishment these microorganisms environments, thereby reducing risk product contamination. To inform on L. diversity transmission, we analyzed genome sequences strains ( n = 88) obtained British Columbia Dairy Inspection Program. Strains were recovered from five different facilities over 10 year period (2007–2017). Analysis whole (WGS) grouped isolates into nine sequence types 11 cgMLST (CT). The majority (93%) belonged lineage II. Within each CT, single nucleotide polymorphism (SNP) differences ranged 0 237 between isolates. A highly similar (0–16 SNPs) cluster 60 isolates, collected 9 years within one facility (#71), was identified suggesting possible persistent population. Analyses content revealed low frequency genes associated stress tolerance, exception widely disseminated cadmium resistance cadA1 cadA2 . distribution virulence mutations internalin varied across facilities. Further studies are needed elucidate their phenotypic effect pathogenicity response. These findings demonstrate same region. Findings also showed utility using WGS discern persistence events time.
Language: Английский
Citations
6
Microorganisms, Journal Year: 2023, Volume and Issue: 11(6), P. 1603 - 1603
Published: June 17, 2023
Precise classification of foodborne pathogen Listeria monocytogenes is a necessity in efficient disease surveillance, outbreak detection, and source tracking throughout the food chain. In this study, total 150 L. isolates from various products, processing environments, clinical sources were investigated for variations virulence, biofilm formation, presence antimicrobial resistance genes based on their Whole-Genome Sequences. Clonal complex (CC) determination Multi-Locus Sequence Typing (MLST) revealed twenty-eight CC-types including eight representing novel CC-types. The comprising share majority known (cold acid) stress tolerance are all genetic lineage II, serogroup 1/2a-3a. Pan-genome-wide association analysis by Scoary using Fisher's exact test identified eleven specifically associated with isolates. Screening virulence ABRicate tool uncovered Pathogenicity Islands (LIPIs) other genes. Specifically, distributions actA, ecbA, inlF, inlJ, lapB, LIPI-3, vip across found to be significantly CC-dependent while ami, LIPI-3 was specifically. addition, Roary-derived phylogenetic grouping Antimicrobial-Resistant Genes (AMRs) that thiol transferase (FosX) gene present I isolates, lincomycin ABC-F-type ribosomal protection protein (lmo0919_fam) also genetic-lineage-dependent. More importantly, specific CC-type consistent when validation performed fully assembled, high-quality complete genome sequences (n = 247) extracted National Centre Biotechnology Information (NCBI) microbial genomes database. This work highlights usefulness MLST-based CC typing as classifying
Language: Английский
Citations
11
Microorganisms, Journal Year: 2024, Volume and Issue: 12(2), P. 345 - 345
Published: Feb. 7, 2024
Listeria monocytogenes is an important foodborne pathogen with worldwide prevalence. Understanding the variability in potential pathogenicity among strains of different subtypes crucial for risk assessment. In this study, growth, survival, and virulence characteristics 16 L. isolated from imported meat China (2018–2020) were investigated. The maximum specific growth rate (μmax) lag phase (λ) evaluated using time-to-detection (TTD) method Baranyi model at temperatures (25, 30, 37 °C). Survival determined by D-values population reduction after exposure to heat (60, 62.5, 65 °C) acid (HCl, pH = 2.5, 3.5, 4.5). was via adhesion invasion Caco-2 cells, motility, lethality Galleria mellonella. compared lineages subtypes. results indicate that lineage I exhibited a higher than II three temperatures, particularly serotype 4b within I. At all tested, serotypes 1/2a 1/2b consistently demonstrated resistance other No significant differences log observed between 4.5. However, 1/2c significantly low 2.5. terms virulence, outperformed strains. cells G. mellonella those serotypes. This study provides meaningful insights into monocytogenes, offering valuable information understanding correlation monocytogenes.
Language: Английский
Citations
4
The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 923, P. 171331 - 171331
Published: Feb. 29, 2024
Language: Английский
Citations
3
Applied and Environmental Microbiology, Journal Year: 2022, Volume and Issue: 88(10)
Published: April 28, 2022
To understand the molecular mechanisms that contribute to stress responses of important foodborne pathogen Listeria monocytogenes, we collected 139 strains (meat, n = 25; dairy, 10; vegetable, 8; seafood, 14; mixed food, 4; and food processing environments, 78), mostly isolated in Ireland, subjected them whole-genome sequencing. These were compared 25 Irish clinical isolates 4 well-studied reference strains. Core genome pan-genome analysis confirmed a highly clonal deeply branched population structure. Multilocus sequence typing showed this collection contained diverse range from L. monocytogenes lineages I II. Several groups with similar content traced single or multiple business operators, providing evidence strain persistence prevalence, respectively. Phenotypic screening assays for tolerance salt resistance acid revealed variants within several complexes phenotypically distinct. Five these phenotypic outliers found carry mutations sigB operon, which encodes stress-inducible sigma factor B. Transcriptional three carried sigB, rsbV, rsbU had reduced SigB activity, as predicted. exhibited increased displayed decreased low pH stress. Overall, study shows loss-of-function operon are comparatively common field isolates, probably reflecting cost general response reproductive fitness pathogen. IMPORTANCE The bacterial frequently contaminates various categories products is able cause life-threatening infections when ingested by humans. Thus, it control growth bacterium understanding allow its proliferation under suboptimal conditions. In study, intraspecies heterogeneity was observed across consisting mainly isolates. Through comparisons phenotypes observed, identified impairment regulator SigB. Two used widely challenge studies evaluating potential monocytogenes. Given loss function associated atypical properties, use should be re-evaluated.
Language: Английский
Citations
13
Foods, Journal Year: 2023, Volume and Issue: 12(6), P. 1200 - 1200
Published: March 12, 2023
Listeriosis is a serious infectious disease with one of the highest case fatality rates (ca. 20%) among diseases manifested from bacterial foodborne pathogens in humans, while dairy products are often implicated as sources human infection Listeria monocytogenes. In this study, we characterized phenotypically and genetically by whole-genome sequencing (WGS) 54 L. monocytogenes strains isolated Myzithra, traditional Greek soft whey cheese (48 isolates), swabs collected surfaces processing plant (six isolates) Epirus region Greece. All but strain belonged to polymerase chain reaction (PCR) serogroups IIa (16.7%) IIb (81.5%), corresponding serotypes 1/2a, 3a 1/2b, 3b, 7, respectively. The latter was identified PCR-serogroup IVb (1.8%) 4b, 4d, 4e. Bioinformatics analysis revealed presence five sequence types (STs) clonal complexes (CCs); ST1, ST3, ST121, ST 155, ST398 CC1, CC3, CC121, CC155, CC398 were thus detected 1.9, 83.3, 11.0, 1.9% isolates, Antibiograms pathogen against panel seven selected antibiotics (erythromycin, tetracycline, benzylpenicillin, trimethoprim-sulfamethoxazole, ampicillin, ciprofloxacin, meropenem) showed that 50 (92.6%), six surface isolates also included, intermediately resistant ciprofloxacin susceptible rest antimicrobial agents tested, whereas strong resistance use single three recorded four (7.4%) Myzithra samples. Thence, minimum inhibitory concentrations (MICs) determined for erythromycin (MIC = 0.19 μg/mL), ≥ meropenem 0.64 finally, just deemed antibiotic. phylogenetic positions their genetic variability through WGS, whilst stress response virulence gene conducted. Findings work should be useful they could utilized epidemiological investigations food environment, revealing possible contamination scenarios, acquired along production chain.
Language: Английский
Citations
7
FEMS Microbiology Letters, Journal Year: 2024, Volume and Issue: 371
Published: Jan. 1, 2024
Abstract The ability to sense and respond effectively acidic stress is important for microorganisms survive proliferate in fluctuating environments. As specific metabolic activities can serve buffer the cytoplasmic pH, rewire their metabolism favour these reactions thereby mitigate acid stress. orally acquired pathogen Listeria monocytogenes exploits alternative overcome encountered human stomach or food products. In this minireview, we discuss processes L. that stress, with an emphasis on proton-depleting reactions, including glutamate decarboxylation, arginine/agmatine deimination, fermentative acetoin production. We also summarize recent findings regulatory mechanisms control expression of genes are responsible activities, general response regulator SigB, arginine repressor ArgR, recently discovered RofA-like transcriptional GadR. further importance reprogramming context products within host. Finally, highlight some outstanding challenges field, understanding acid-sensing mechanisms, role intraspecies heterogeneity resistance, how a fundamental be exploited formulation improve safety reduce waste.
Language: Английский
Citations
1
Food Research International, Journal Year: 2024, Volume and Issue: 196, P. 115106 - 115106
Published: Sept. 15, 2024
Language: Английский
Citations
1
Microorganisms, Journal Year: 2022, Volume and Issue: 11(1), P. 65 - 65
Published: Dec. 26, 2022
The aim of this study was to investigate the level strain variability amongst food and clinical Listeria monocytogenes isolates growing at low temperatures (4 7 °C) in both laboratory media real matrices. Isolates (n = 150) grown demonstrated a large variation growth profiles measured using optical density. Overall, it noted that exhibited significantly higher rate (p ≤ 0.05) °C than other isolates. Analysis variance (ANOVA) tests grouped Multi Locus Sequence Typing (MLST) revealed clonal complex 18 (CC18) were faster 4 CC-type while CC101, CC18, CC8, CC37 CC14 CC types °C. Euclidean distance Ward method-based hierarchical clustering mean rates classified 33.33% as growing. Fast slow representative selected from cluster analysis determined plate count data model In agreement with density experiments, CC18 CC121 slower media, UHT milk fish pie. same trend observed chocolate but differences not statistically significant. Moreover, pan-genome (Scoary) isolate genome sequences only identified six genes unknown function associated increased cold tolerance failing identify any known genes. an association consistent matrices between type tolerance.
Language: Английский
Citations
3