An rfaH Mutant of Salmonella enterica Serovar Typhimurium is Attenuated in Swine and Reduces Intestinal Colonization, Fecal Shedding, and Disease Severity Due to Virulent Salmonella Typhimurium

The fate of Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Vibrio vulnificus in oysters treated with chitosan was investigated. Three concentrations (0.5, 1.0, and 2.0%) of chitosan in 0.5% hydrochloric acid were prepared and coated onto raw oysters, which were then stored at 4°C for 12 days. Untreated oysters and oysters coated with 0.5% hydrochloric acid without chitosan were used as controls. S. aureus cells were most sensitive to 2.0% chitosan followed by 0.5 and 1.0%. In general, chitosan treatment of oysters produced a decline in the population of S. aureus by 1 to 4 log CFU/ml compared with the untreated control. Chitosan treatment had no influence on the reduction of Salmonella Typhimurium over the 12-day storage period; inhibition of Salmonella Typhimurium growth was similar in both the control samples and the chitosan-treated samples. However, time of storage had a major effect on the survival of Salmonella Typhimurium on oysters. Neither time nor chitosan concentration had a significant effect on the growth of V. vulnificus during storage. All treatments were similar in inhibiting V. vulnificus growth.

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MDR Salmonella enterica serovar Typhimurium ST34 carrying mcr-1 isolated from cases of bloodstream and intestinal infection in children in China

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz415 ◽

2019 ◽

Vol 75 (1) ◽

pp. 92-95 ◽

Cited By ~ 2

Author(s):

Qixia Luo ◽

Fen Wan ◽

Xiao Yu ◽

Beiwen Zheng ◽

Yunbo Chen ◽

...

Keyword(s):

Salmonella Typhimurium ◽

Salmonella Enterica ◽

Salmonella Enterica Serovar Typhimurium ◽

Heavy Metal Resistance ◽

Metal Resistance ◽

Ecological Niches ◽

Salmonella Infection ◽

Serovar Typhimurium ◽

Multiple Resistance Genes ◽

Tn7 Transposition

Abstract Objectives Children are vulnerable to Salmonella infection due to their immature immune system. Cases of infection with mcr-1-harbouring Salmonella in child inpatients have not been reported in China before. Methods Salmonella isolates from gastroenteritis and bacteraemia were screened using primers targeting mcr-1. Complete genome sequences of mcr-1-harbouring isolates were determined using the PacBio RS II platform. The transferability of mcr-1-harbouring plasmids was verified by conjugation. Results We investigated two mcr-1-carrying polymyxin-resistant Salmonella enterica serovar Typhimurium ST34 isolates, S61394 and S44712, from bloodstream and intestinal Salmonella infection of two child inpatients, respectively. Both isolates were non-susceptible to commonly used antibiotics for children that compromised the success of clinical treatment and infection control. The mcr-1-harbouring plasmids pLS61394-MCR and pLS44712-MCR (from S61394 and S44712, respectively) were both conjugative pHNSHP45-2-like IncHI2-type epidemic plasmids carrying multiple resistance genes. Compared with pHNSHP45-2, a ∼33 kb insertion region encoding Tn7 transposition protein and heavy metal resistance proteins was identified in pLS61394-MCR, which might enhance adaptation of bacteria carrying this plasmid to various ecological niches. The phylogenetic tree of worldwide mcr-harbouring Salmonella indicated a host preference of mcr and a worldwide and cross-sectoral prevalence of the mcr-positive Salmonella ST34 clone. Conclusions To our knowledge, for the first time we report completed whole genomes of mcr-1-positive MDR Salmonella Typhimurium ST34 isolated from infected children in China, suggesting that improved surveillance is imperative for tackling the dissemination of mcr-harbouring MDR Salmonella Typhimurium ST34.

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Lactic acid bacteria and bifidobacteria attenuate the proinflammatory response in intestinal epithelial cells induced by Salmonella enterica serovar Typhimurium

Canadian Journal of Microbiology ◽

10.1139/cjm-2012-0446 ◽

2013 ◽

Vol 59 (1) ◽

pp. 9-17 ◽

Cited By ~ 26

Author(s):

Christine M. Carey ◽

Magdalena Kostrzynska

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Salmonella Typhimurium ◽

Salmonella Enterica ◽

Salmonella Enterica Serovar Typhimurium ◽

Farm Animals ◽

Bifidobacterium Adolescentis ◽

Lactobacillus Kefir ◽

Serovar Typhimurium ◽

Ht 29

Inflammation is a physiological response to infections and tissue injury; however, abnormal immune responses can give rise to chronic inflammation and contribute to disease progression. Various dietary components, including probiotic lactic acid bacteria and prebiotics, have the potential to modulate intestinal inflammatory responses. One factor in particular, the chemokine interleukin-8 (IL-8, CXCL-8), is one of the major mediators of the inflammatory response. The purpose of this study was to investigate modulation of the inflammatory host response induced by Salmonella enterica serovar Typhimurium DT104 in the presence of selected probiotics and lactic acid bacteria (LAB) isolated from human sources, dairy products, and farm animals. IL-8 gene expression and protein production in HT-29 cells were evaluated by real-time PCR and ELISA, respectively. Pre-incubation of HT-29 cells with Lactobacillus kefir IM002, Bifidobacterium adolescentis FRP 61, Bifidobacterium longum FRP 68 and FRP 69, Bifidobacterium breve FRP 334, and Leuconostoc mesenteroides IM080 significantly inhibited IL-8 secretion induced by Salmonella Typhimurium DT104. Co-culture of selected probiotics and Salmonella Typhimurium DT104 reduced IL-8 production, while potential probiotics and LAB had no effect on IL-8 secretion in HT-29 cells preincubated with Salmonella Typhimurium DT104 prior to adding probiotics. Lactobacillus kefir IM002 supernatant also significantly reduced IL-8 production. In conclusion, our study suggests that probiotic bifidobacteria and LAB modulate cytokine induction and possess anti-inflammatory properties; however, the effectiveness is strain dependent.

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Experimental Use of 2-Nitropropanol for Reduction of Salmonella Typhimurium in the Ceca of Broiler Chicks†‡

Journal of Food Protection ◽

10.4315/0362-028x-67.9.1945 ◽

2004 ◽

Vol 67 (9) ◽

pp. 1945-1947 ◽

Cited By ~ 26

Author(s):

YONG SOO JUNG ◽

ROBIN C. ANDERSON ◽

THOMAS S. EDRINGTON ◽

KENNETH J. GENOVESE ◽

J. ALLEN BYRD ◽

...

Keyword(s):

Fatty Acid ◽

Salmonella Typhimurium ◽

Inhibitory Activity ◽

Salmonella Enterica ◽

Volatile Fatty Acid ◽

Salmonella Enterica Serovar Typhimurium ◽

Broiler Chicks ◽

Serovar Typhimurium ◽

Experimental Use

The effect of 2-nitropropanol (2NPOH) administration on Salmonella enterica serovar Typhimurium in experimentally infected chicks was determined. Chicks orally challenged with 106 CFU/ml of a novobiocin- and naladixic acid–resistant Salmonella Typhimurium at 6 days of age were divided into three groups receiving 0 (control), 6.5, and 13 mg 2NPOH per bird (experiment 1) or four groups receiving 0 (control), 13, 65, and 130 mg 2NPOH per bird (experiment 2). Treatments were administered orally 1 day post–Salmonella challenge. Cecal contents collected at necropsy 24 and 48 h after treatment were subjected to bacterial and volatile fatty acid (VFA) analysis. In experiment 1, concentrations (mean ± SD log CFU per g) of Salmonella were reduced (P < 0.05) in the group administered 13 mg 2NPOH per bird at both the 24- and 48-h samplings compared with the controls (2.58 ± 2.10 versus 4.64 ± 1.79 and 2.88 ± 2.78 versus 5.03 ± 2.42 at 24 and 48 h, respectively). In experiment 2, mean ± SD populations of Salmonella were reduced (P < 0.05) in all groups receiving 2NPOH compared with untreated controls (3.65 ± 2.01, 3.39 ± 2.42, and 3.47 ± 1.55 at 13, 65, and 130 mg, respectively, versus 6.09 ± 1.02). Propionate concentrations were reduced (P < 0.05) by the 13-mg 2NPOH per bird treatment. Total VFA concentrations from the group treated with 13 mg 2NPOH per bird were lower (P < 0.05) by 48, but not 24, hours posttreatment than those from the group treated with 6.5 mg 2NPOH per bird. These results demonstrate the inhibitory activity of 2NPOH against Salmonella Typhimurium in vivo.

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SiiE Is Secreted by the Salmonella enterica Serovar Typhimurium Pathogenicity Island 4-Encoded Secretion System and Contributes to Intestinal Colonization in Cattle

Infection and Immunity ◽

10.1128/iai.01438-06 ◽

2007 ◽

Vol 75 (3) ◽

pp. 1524-1533 ◽

Cited By ~ 64

Author(s):

Eirwen Morgan ◽

Alison J. Bowen ◽

Sonya C. Carnell ◽

Timothy S. Wallis ◽

Mark P. Stevens

Keyword(s):

Salmonella Enterica ◽

Salmonella Enterica Serovar Typhimurium ◽

Pathogenicity Island ◽

Secretion System ◽

Type I ◽

Intestinal Colonization ◽

Serovar Typhimurium

ABSTRACT Here we report that Salmonella enterica serovar Typhimurium pathogenicity island 4 carries a type I secretion system (siiCDF) which secretes an ∼600-kDa protein (encoded by siiE). SiiE is surface expressed, and its production is regulated by HilA. SiiE and SiiF influence colonization in cattle and the invasion of bovine enterocytes.

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Morphology of Salmonella Typhimurium typing phages of the Lilleengen set

Canadian Journal of Microbiology ◽

10.1139/w09-095 ◽

2009 ◽

Vol 55 (12) ◽

pp. 1403-1405 ◽

Cited By ~ 1

Author(s):

Abraham Eisenstark ◽

Wolfgang Rabsch ◽

Hans-W. Ackermann

Keyword(s):

Salmonella Typhimurium ◽

Salmonella Enterica ◽

Salmonella Enterica Serovar Typhimurium ◽

Specific Phage ◽

Serovar Typhimurium ◽

Phage P22 ◽

Salmonella Phage

The Lilleengen scheme for typing Salmonella enterica serovar Typhimurium consists of 12 tailed phages. Ten phages are podoviruses and morphologically identical to Salmonella phage P22. Two phages are siphoviruses and identical to flagella-specific phage χ.

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