An Overview of Molecular Stress Response Mechanisms in Escherichia coli Contributing to Survival of Shiga Toxin-Producing Escherichia coli during Raw Milk Cheese Production

Peng, Silvio; Tasara, Taurai; Hummerjohann, Jörg; Stephan, Roger

doi:10.4315/0362-028x.jfp-10-469

Cited by 34 publications

(21 citation statements)

References 215 publications

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“…In research done on humans, it has been reported that intake of yoghurt increased activity of phagocytes and natural killer cell and production of cytokine and antibody. In vitro studies on cells showed similar results, after exposure to lactic acid bacteria [28][29][30][31]. In a study by Perdigon et al [32] on mice, it was observed that feeding yoghurt and L. acidophilus and L. casei increased IgA and IgA producing cells in the animal small intestine.…”

Section: Discussionsupporting

confidence: 63%

Oral Administration of LBKV-3 as Probiotic Enhances Immunoglobulin Level and Faecal Microflora in Malnutrate Children

Hajare¹

2017

J Prob Health

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Role of probiotics in regulation of immune system and development in microflora has begun to implicate in humans and animals. Inconsistent data exist regarding the effect of a single probiotic strain in malnutrate children. The aim of this study clinically proven Lactobacillus acidophilus strain LBKV-3 intended as probiotc for human was used to test its effect on modulation of immunoglobulin and composition of faecal microflora. To accomplish this task, 135 malnutrate children were orally administrated with buffalo milk as control, fresh curd as a special module for assessment of stimulatory effects and probiotic acidophilus milk used as a probiotic. During feeding, we evaluate the level of saliva IgA, serum IgG and IgE and faecal microflora. The result of our study demonstrated that the frequency of immunoglobulin and microflora was not affected when children consumed buffalo milk. In presence of fresh curd, the level of IgA, IgG and composition of friendly bacteria slightly increases and proportion of pathogenic bacteria declines. However, probiotic acidophilus milk significantly triggers the level of IgA and IgG as well as population of helpful bacteria rises and concentration of pathogenic bacteria declines in comparison to fresh curd. Irrespective of IgA and IgG, the ratio of IgE reduces in presence of fresh curd and probiotic acidophilus milk. Thus, our study showed that probiotic has positive effects on modulation of immunoglobulin and regulation of gut microflora. To confirm these findings, large-scale experiments involving the use of a large number of humans of different age groups and under different health and nutritional condition are required to be performed. Moreover, a different dose or strain of probiotic also warrants further confirmation.

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Section: Discussionsupporting

confidence: 63%

Oral Administration of LBKV-3 as Probiotic Enhances Immunoglobulin Level and Faecal Microflora in Malnutrate Children

Hajare¹

2017

J Prob Health

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“…Authors have observed D values of 31 min at 50°C (46), 11.51 at 55°C (47) in turkey, between 2.14 and 8.32 min at 56°C in apple juice (48), and 6.6 min at 55°C (46) and between 0.95 and 4.98 min at 58°C (49) in milk. It has also been observed that cooking temperatures of 53°C or higher result in a rapid decrease in STEC populations during the first hours of cheese making and contribute to the safety of this type of cheese (50). In our study, during ripening, these pathogens remained detectable only after enrichment.…”

Section: Discussionmentioning

confidence: 50%

Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

Miszczycha

Perrin

Ganet

et al. 2013

Appl Environ Microbiol

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e Shiga toxin-producing Escherichia coli (STEC) is an important cause of food-borne illness. The public health implication of the presence of STEC in dairy products remains unclear. Knowledge of STEC behavior in cheeses would help to evaluate the human health risk. The aim of our study was to observe the growth and survival of experimentally inoculated STEC strains in raw-milk cheeses manufactured and ripened according to five technological schemes: blue-type cheese, uncooked pressed cheese with long ripening and with short ripening steps, cooked cheese, and lactic cheese. Cheeses were contaminated with different STEC serotypes (O157:H7, O26:H11, O103:H2, and O145:H28) at the milk preparation stage. STEC growth and survival were monitored on selective media during the entire manufacturing process. STEC grew (2 to 3 log 10 CFU · g ؊1 ) in blue-type cheese and the two uncooked pressed cheeses during the first 24 h of cheese making. Then, STEC levels progressively decreased in cheeses that were ripened for more than 6 months. In cooked cheese and in lactic cheese with a long acidic coagulation step (pH < 4.5), STEC did not grow. Their levels decreased after the cooking step in the cooked cheese and after the coagulation step in the lactic cheese, but STEC was still detectable at the end of ripening and storage. A serotype effect was found: in all cheeses studied, serotype O157:H7 grew less strongly and was less persistent than the others serotypes. This study improves knowledge of the behavior of different STEC serotypes in various raw-milk cheeses.

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“…In food products, Escherichia coli must adapt against various stressors including elevated salt concentrations and organic acids to survive. This adaptation is performed through activation of different cellular response mechanisms that may allow survival and growth in food such as raw milk cheese (Peng et al, 2011). Survival of Shiga toxin-producing E. coli (STEC) in food poses a food safety risk.…”

Section: Introductionmentioning

confidence: 99%

Transcriptional analysis of different stress response genes inEscherichia colistrains subjected to sodium chloride and lactic acid stress

Peng

Stephan

Hummerjohann

et al. 2014

FEMS Microbiol Lett

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Survival of Escherichia coli in food depends on its ability to adapt against encountered stress typically involving induction of stress response genes. In this study, the transcriptional induction of selected acid (cadA, speF) and salt (kdpA, proP, proW, otsA, betA) stress response genes was investigated among five E. coli strains, including three Shiga toxin-producing strains, exposed to sodium chloride or lactic acid stress. Transcriptional induction upon lactic acid stress exposure was similar in all but one E. coli strain, which lacked the lysine decarboxylase gene cadA. In response to sodium chloride stress exposure, proW and otsA were similarly induced, while significant differences were observed between the E. coli strains in induction of kdpA, proP and betA. The kdpA and betA genes were significantly induced in four and three strains, respectively, whereas one strain did not induce these genes. The proP gene was only induced in two E. coli strains. Interestingly, transcriptional induction differences in response to sodium chloride stress exposure were associated with survival phenotypes observed for the E. coli strains in cheese as the E. coli strain lacking significant induction in three salt stress response genes investigated also survived poorly compared to the other E. coli strains in cheese.

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An Overview of Molecular Stress Response Mechanisms in Escherichia coli Contributing to Survival of Shiga Toxin-Producing Escherichia coli during Raw Milk Cheese Production

Cited by 34 publications

References 215 publications

Oral Administration of LBKV-3 as Probiotic Enhances Immunoglobulin Level and Faecal Microflora in Malnutrate Children

Oral Administration of LBKV-3 as Probiotic Enhances Immunoglobulin Level and Faecal Microflora in Malnutrate Children

Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

Transcriptional analysis of different stress response genes inEscherichia colistrains subjected to sodium chloride and lactic acid stress

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