salmonella enterica serovar typhi
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2022 ◽  
Vol 335 ◽  
pp. 00003
Author(s):  
Lilik Eka Radiati ◽  
Hariana Tri Juliyanti ◽  
Cindy Heryanti Kusuma Wardhani

The purpose of this reasearch was to determine the effect of storage period goat’s milk kefir (GMK) on total LAB, total mineral levels included Ca and Mg and antimicrobial activity to pathogenic microbes. The materials used was GMK. This research was conducted using Completely Randomized Design with 4 treatments and 4 replications. The treatments were storage period that consist of D0 (0 day), D1 (7 days), D2 (14 days), and D3 (21 days). Total calculation of LAB used TPC (Total Plate Count). Samples were diluted from 10-1 to 10-8, then incoculated PCA medium by using pour plate method. Petri dish was incubated at 37ºC for 48 hours. Calcium and magnesium levels were calculed base AAS method. The result of this study was analyzed using analysis of variance (ANOVA), then followed by Duncan’s Multiple Range Test (DMRT). The storage time treatment has a significant effect on the total microbial count, mineral levels (Ca and Mg) and inhibition zone of Staphylococcus aureus, Escherichia coli and Salmonella enterica serovar typhi on goat's milk kefir. Average clear zone Staphylococcus aureus 2.60 – 3.18 mm. Average inhibition zone Escherichia coli 2.09 – 3.32 mm. Average clear zone Salmonella enterica serovar typhi 1.97 – 2.72 mm.


2021 ◽  
Vol 9 (10) ◽  
pp. 2155
Author(s):  
Wan Ratmaazila Wan Makhtar ◽  
Izwan Bharudin ◽  
Nurul Hidayah Samsulrizal ◽  
Nik Yusnoraini Yusof

In recent years, the advance in whole-genome sequencing technology has changed the study of infectious diseases. The emergence of genome sequencing has improved the understanding of infectious diseases, which has revamped many fields, such as molecular microbiology, epidemiology, infection control, and vaccine production. In this review we discuss the findings of Salmonella enterica serovar Typhi genomes, publicly accessible from the initial complete genome to the recent update of Salmonella enterica serovar Typhi genomes, which has greatly improved Salmonella enterica serovar Typhi and other pathogen genomic research. Significant information on genetic changes, evolution, antimicrobial resistance, virulence, pathogenesis, and investigation from the genome sequencing of S. Typhi is also addressed. This review will gather information on the variation of the Salmonella enterica serovar Typhi genomes and hopefully facilitate our understanding of their genome evolution, dynamics of adaptation, and pathogenesis for the development of the typhoid point-of-care diagnostics, medications, and vaccines.


2021 ◽  
Vol 10 (41) ◽  
Author(s):  
Gi Young Lee ◽  
Jeongmin Song

Salmonella enterica serovar Typhi ISP2825, isolated in 1983 from a Chilean patient, is one of the major S. Typhi strains used for research, along with strains Ty2, CT18, and H58. The complete genome sequence of ISP2825, consisting of a 4,774,014-bp circular chromosome, will help us understand typhoid pathogenesis and evolution.


2021 ◽  
Vol 12 ◽  
Author(s):  
Rosângela Salerno-Gonçalves ◽  
Tasmia Rezwan ◽  
David Luo ◽  
Hervé Tettelin ◽  
Marcelo B. Sztein

Mucosal-associated invariant T (MAIT) cells are an innate-like population of T cells that display a TCR Vα7.2+ CD161+ phenotype and are restricted by the nonclassical MHC-related molecule 1 (MR1). Although B cells control MAIT cell development and function, little is known about the mechanisms underlying their interaction(s). Here, we report, for the first time, that during Salmonella enterica serovar Typhi (S. Typhi) infection, HLA-G expression on B cells downregulates IFN-γ production by MAIT cells. In contrast, blocking HLA-G expression on S. Typhi-infected B cells increases IFN-γ production by MAIT cells. After interacting with MAIT cells, kinetic studies show that B cells upregulate HLA-G expression and downregulate the inhibitory HLA-G receptor CD85j on MAIT cells resulting in their loss. These results provide a new role for HLA-G as a negative feedback loop by which B cells control MAIT cell responses to antigens.


Author(s):  
Umar Saeed ◽  
◽  
Sara Rizwan Uppal ◽  
Zahra Zahid Piracha ◽  
Rizwan Uppal ◽  
...  

There have been several outbreaks of antimicrobial resistant (AMR) strains of Salmonella enterica serovar Typhi that cause extensively drug resistant (XDR) typhoid fever in Pakistan. It has been observed that many clinicians use serological diagnostic tests such as Widal agglutination, and TyphiDOT that detects IgM and IgG antibodies against the outer membrane protein of S. Typhi. However, it has been confirmed by many scientists that these test may lead to misdiagnosis against XDR S. Typhi. Due to lack of implementation strategies health authorities are unable to hamper Widal or TyphiDOT tests which are still practiced in many rural and urban areas.


2021 ◽  
Vol 22 (18) ◽  
pp. 10003
Author(s):  
Jingting Wang ◽  
Shuai Ma ◽  
Wanwu Li ◽  
Xinyue Wang ◽  
Di Huang ◽  
...  

Salmonella enterica serovar Typhi (S. Typhi) is a human-limited intracellular pathogen and the cause of typhoid fever, a severe systemic disease. Pathogen–host interaction at the metabolic level affects the pathogenicity of intracellular pathogens, but it remains unclear how S. Typhi infection influences host metabolism for its own benefit. Herein, using metabolomics and transcriptomics analyses, combined with in vitro and in vivo infection assays, we investigated metabolic responses in human macrophages during S. Typhi infection, and the impact of these responses on S. Typhi intracellular replication and systemic pathogenicity. We observed increased glucose content, higher rates of glucose uptake and glycolysis, and decreased oxidative phosphorylation in S. Typhi-infected human primary macrophages. Replication in human macrophages and the bacterial burden in systemic organs of humanized mice were reduced by either the inhibition of host glucose uptake or a mutation of the bacterial glucose uptake system, indicating that S. Typhi utilizes host-derived glucose to enhance intracellular replication and virulence. Thus, S. Typhi promotes its pathogenicity by inducing metabolic changes in host macrophages and utilizing the glucose that subsequently accumulates as a nutrient for intracellular replication. Our findings provide the first metabolic signature of S. Typhi-infected host cells and identifies a new strategy utilized by S. Typhi for intracellular replication.


2021 ◽  
Vol 15 (9) ◽  
pp. e0009755
Author(s):  
Paula Diaz Guevara ◽  
Mailis Maes ◽  
Duy Pham Thanh ◽  
Carolina Duarte ◽  
Edna Catering Rodriguez ◽  
...  

Little is known about the genetic diversity of Salmonella enterica serovar Typhi (S. Typhi) circulating in Latin America. It has been observed that typhoid fever is still endemic in this part of the world; however, a lack of standardized blood culture surveillance across Latin American makes estimating the true disease burden problematic. The Colombian National Health Service established a surveillance system for tracking bacterial pathogens, including S. Typhi, in 2006. Here, we characterized 77 representative Colombian S. Typhi isolates collected between 1997 and 2018 using pulse field gel electrophoresis (PFGE; the accepted genotyping method in Latin America) and whole genome sequencing (WGS). We found that the main S. Typhi clades circulating in Colombia were clades 2.5 and 3.5. Notably, the sequenced S. Typhi isolates from Colombia were closely related in a global phylogeny. Consequently, these data suggest that these are endemic clades circulating in Colombia. We found that AMR in S. Typhi in Colombia was uncommon, with a small subset of organisms exhibiting mutations associated with reduced susceptibility to fluoroquinolones. This is the first time that S. Typhi isolated from Colombia have been characterized by WGS, and after comparing these data with those generated using PFGE, we conclude that PFGE is unsuitable for tracking S. Typhi clones and mapping transmission. The genetic diversity of pathogens such as S. Typhi is limited in Latin America and should be targeted for future surveillance studies incorporating WGS.


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