Characterization of internalin genes in Listeria monocytogenes from food and humans, and their association with the invasion of Caco-2 cells

In this study, the gene sequences of inlA in 120L. monocytogenes isolates from food (n  = 107) and humans (n = 13) were analyzed. Premature stop codon (PMSC) mutations ininlA were identified in 51 isolates (50 from food and 1 from human). Six mutation types of PMSCs were identified. Among the 51 isolates with PMSCs ininlA, there were 44 serogroup 1/2c, 3c isolates from food, of which seven belonged to serogroups 1/2a, 3a. A total of 153,382 SNPs in 2247 core genes from 42 genomes were identified and used to construct a phylogenetic tree. Serotype 1/2c isolates with inlA PMSC mutations were grouped together. Cell culture studies on 21 isolates showed that the invasion to Caco-2 cells was significantly reduced among isolates with inlA PMSC mutations compared to those without PMSC mutations (P  
Source: Gut Pathogens - Category: Microbiology Source Type: research

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We present the case of a premature newborn whose mother had a rash during pregnancy; the newborn had severe early sepsis because of Listeria monocytogenes and histopathologically suggestive findings of the placenta. Obstetricians and neonatologists should suspect listeriosis in cases with compatible epidemiological history, clinical features, and examination findings of the placenta.
Source: Revista da Sociedade Brasileira de Medicina Tropical - Category: Tropical Medicine Source Type: research
Pita Pal Foods, LP, based in Houston, Texas, recalled 87 different types of hummus that were distributed in May and June after traces of bacteria were detected in the factory.
Source: the Mail online | Health - Category: Consumer Health News Source Type: news
Publication date: Available online 17 July 2019Source: LWTAuthor(s): Jeong Hyeon Lee, Kyung Bin Song, Eun Ji Choi, Hong Kyeong Kim, Hae Woong Park, Ho Hyun ChunAbstractWe evaluated the efficiency of high hydrostatic pressure (HHP, 100–600 MPa) and 5% red ginseng concentrate (RGC) supplementation in inactivating foodborne pathogens and the impacts of treatment on the quality of kimchi sauce. Listeria monocytogenes and Staphylococcus aureus decreased by 4.02 log CFU/g with increasing HHP intensity, in kimchi sauces supplemented with or without RGC. In addition, Escherichia coli O157:H7 and Salmonella Typhimurium decr...
Source: LWT Food Science and Technology - Category: Food Science Source Type: research
Here are some of the latest health and medical news developments, compiled by the editors of HealthDay: Growers Express Expands Recall of Fresh Vegetable Products A recall of fresh vegetable products that may be contaminated with listeria has been...
Source: - Daily MedNews - Category: General Medicine Source Type: news
This is the third time in eight months that an Eat Smart product has been recalled in Canada because of Listeria, one of the most dangerous foodborne pathogens.
Source: CBC | Health - Category: Consumer Health News Tags: News/Health Source Type: news
Publication date: Available online 15 July 2019Source: Food ControlAuthor(s): S. Pedrós-Garrido, I. Clemente, J.B. Calanche, S. Condón-Abanto, J.A. Beltrán, J.G. Lyng, N. Brunton, D. Bolton, P. WhyteAbstractThe application of natural preservatives on fresh fish has potential to extend shelf-life. In the present study, 8 essential oils (EOs) (lemon, lemongrass, lime, garlic, onion, oregano, thyme and rosemary) and 3 organic acids (OAs) (ascorbic, citric and lactic) were evaluated. The antimicrobial activity of these compounds was tested in-vitro against four confirmed Listeria spp. isolated from retail ...
Source: Food Control - Category: Food Science Source Type: research
Publication date: Available online 13 July 2019Source: Food ControlAuthor(s): Qingli Dong, Wenmin Zhang, Liang Guo, Hongmei Niu, Qing Liu, Xiang WangAbstractTo verify the effect of Lactobacillus plantarum subsp. plantarum CICC 6257 individually (T1) and in combination with low O2-MAP (3% O2 /10% CO2 /87% N2) (T2) on the pathogenic potential of Listeria monocytogenes in cabbage stored at 10 °C, the potential for growth, the ability to survive a simulated gastrointestinal tract and the expression of virulence genes of L. monocytogenes were analyzed during 6 days of storage. It indicated that the growth of L. monocytogene...
Source: Food Control - Category: Food Science Source Type: research
Publication date: October 2019Source: LWT, Volume 113Author(s): Alejandra Londero, Magdalena Costa, Lucía Galli, Victoria Brusa, Luciano Linares, Mónica Prieto, Gerardo LeottaAbstractWe characterized L. monocytogenes strains isolated from ground beef (n = 40) and butcher shop environmental (n = 99) samples before and after implementing improvement actions. Strains were serotyped and subtyped by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and ApaI-pulsed-field gel electrophoresis (PFGE) to establish their epidemiological relationships, clarify the contamination ...
Source: LWT Food Science and Technology - Category: Food Science Source Type: research
Publication date: September 2019Source: Food Packaging and Shelf Life, Volume 21Author(s): Tingting Tao, Chao Ding, Nengneng Han, Yu Cui, Xianjin Liu, Cunzheng ZhangAbstractMinimally processed vegetables have a short shelf life and are susceptible to contamination of various foodborne pathogens. The aim of this work is to evaluate the bactericidal efficacy of pulsed light (PL) against four common foodborne pathogens inoculated on lettuce surface and its impact on quality attributes of lettuce through 8 days of storage at 4 °C. The results indicated that PL treatments were effective for inactivating the pathogens...
Source: Food Packaging and Shelf Life - Category: Food Science Source Type: research
In this study, the role of RsbR inL. monocytogenes under mild and severe stresses was investigated. Strains with genetic deletion ( ΔrsbR), complementation (C-ΔrsbR), and phosphorylation site mutations in thersbR (RsbR-T175A, RsbR-T209A, and RsbR-T175A-T209A) were constructed to evaluate the roles of these RsbR sequences in listerial growth and survival. SigB was examined at the transcriptional and translational levels. Deletion ofrsbR reduced listerial growxth and survival in response to acidic stress. Substitution of the phosphorylation residue RsbR-T175A disabled RsbR complementation, while RsbR-T209A signif...
Source: Journal of Zhejiang University. Science. B. - Category: Universities & Medical Training Source Type: research
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