Latest Research News on Salmonella Enterica: Jan – 2020

Host adapted serotypes of Salmonella enterica

Salmonella constitutes a genus of zoonotic bacteria of worldwide economic and health importance. the present view of salmonella taxonomy assigns the members of this genus to 2 species: S. enterica and S. bongori. S. enterica itself is split into six subspecies, enterica, salamae, arizonae, diarizonae, indica, and houtenae, also referred to as subspecies I, II, IIIa, IIIb, IV, and VI, respectively [1]. Members of Salmonella enterica subspecies enterica are mainly related to warm-blooded vertebrates and are usually transmitted by ingestion of food or water contaminated by infected faeces. The pathogenicity of most of the distinct serotypes remains undefined, and even within the foremost common serotypes, many questions remain to be answered regarding the interactions between the organism and therefore the infected host. [1]

Salmonella enterica Serovar Typhimurium Exploits Inflammation to Compete with the Intestinal Microbiota

Most mucosal surfaces of the mammalian body are colonized by microbial communities (“microbiota”). A high density of commensal microbiota inhabits the intestine and shields from infection (“colonization resistance”). The virulence strategies allowing enteropathogenic bacteria to successfully compete with the microbiota and overcome colonization resistance are poorly understood. Here, we investigated manipulation of the intestinal microbiota by the enteropathogenic bacterium Salmonella enterica subspecies 1 serovar Typhimurium (S. Tm) during a mouse colitis model: we found that inflammatory host responses induced by S. Tm changed microbiota composition and suppressed its growth. In contrast to wild-type S. Tm, an avirulent invGsseD mutant failing to trigger colitis was outcompeted by the microbiota. [2]

Evolution of pathogenicity islands of Salmonella enterica

Virulence genes located on pathogenicity islands play an important role within the pathogenesis of Salmonella enterica infections. Salmonella pathogenicity islands (SPI) contribute to host cell invasion and intracellular pathogenesis. at the present , 12 SPI are described. Although size, structure and performance of those SPI, also because the distribution in Salmonella subspecies and serovars are often markedly different, several common motifs are present among SPI. during this review, the characteristics of SPI are described with specialise in the evolution of those genetic elements. [3]

Novel Imidazole and Methoxybenzylamine Growth Inhibitors Affecting Salmonella Cell Envelope Integrity and its Persistence in Chickens

The control of Salmonella from farm to fork is challenging thanks to the emergence of antimicrobial-resistant isolates and therefore the limited effects of current control methods. Advanced chemical technologies have made accessible a good range of uncharacterized small molecules (SMs) with encouraging chemical properties for antimicrobial treatment. Of the 4,182 SMs screened in vitro, four cidal SMs were effective at 10 µM and better against several serotypes, antibiotic-resistant, and biofilm embedded Salmonella enterica subsp. enterica serotype Typhimurium by altering cell wall integrity. The four SMs displayed synergistic effects with ciprofloxacin, meropenem and cefeprime against Salmonella. [4]

Survival of Salmonella enterica ssp. enterica ser. Typhi in Brewed Pito Retailed in Accra

Aim: This study aimed toward ascertaining the survival ability of S. typhi in both fermented and unfermented pito.

Study Design: The study followed an experimental design pattern.

Place and Duration of Study: The study was administered at the Microbiology Laboratory of Radford University College, East Legon.

Methodology: S. typhi was introduced into pito samples and subsequently sub-cultured unto Salmonella-Shigella agar for twenty-four hours and therefore the process repeated for five (5) consecutive days. The antimicrobial potential of pito against S. typhi was also investigated.

Results: Culture yielded no bacterial growth and pito had no significant antimicrobial effect on isolate. [5]

Reference

[1] Uzzau, S., Brown, D.J., Wallis, T., Rubino, S., Leori, G., Bernard, S., Casadesús, J., Platt, D.J. and Olsen, J.E., 2000. Host adapted serotypes of Salmonella enterica. Epidemiology & Infection, 125(2), (Web Link)

[2] Stecher, B., Robbiani, R., Walker, A.W., Westendorf, A.M., Barthel, M., Kremer, M., Chaffron, S., Macpherson, A.J., Buer, J., Parkhill, J. and Dougan, G., 2007. Salmonella enterica serovar typhimurium exploits inflammation to compete with the intestinal microbiota. PLoS biology, 5(10), (Web Link)

[3] Hensel, M., 2004. Evolution of pathogenicity islands of Salmonella enterica. International Journal of Medical Microbiology, 294(2-3), (Web Link)

[4] Novel Imidazole and Methoxybenzylamine Growth Inhibitors Affecting Salmonella Cell Envelope Integrity and its Persistence in Chickens
Loïc Deblais, Yosra A. Helmy, Dipak Kathayat, Huang-chi Huang, Sally A. Miller & Gireesh Rajashekara
Scientific Reports volume 8, (Web Link)

[5] Emmanuel, O., Onyedika, C.-O., A. Servacious, A. and N. Orish, V. (2018) “Survival of Salmonella enterica ssp. enterica ser. Typhi in Brewed Pito Retailed in Accra”, International Journal of TROPICAL DISEASE & Health, 30(4), (Web Link)

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