Functional Identification and Genetic Analysis of O-Antigen Gene Clusters of Food-Borne Pathogen O:10 and Other Uncommon Serotypes, Further Revealing Their Virulence Profiles.

is a globally distributed food-borne gastrointestinal pathogen. The O-antigen variation-determined serotype is an important characteristic of , allowing intraspecies classification for diagnosis and epidemiology purposes. Among the 11 serotypes associated with human yersiniosis, O:3, O:5,27, O:8, and O:9 are the most prevalent, and their O-antigen gene clusters have been well defined.

CobB-mediated deacetylation of the chaperone CesA regulates O157:H7 virulence.

Enterohemorrhagic (EHEC) O157:H7 is a common food-borne pathogen that can cause acute diseases. Lysine acetylation is a post-translational modification (PTM) that occurs in various prokaryotes and is regulated by CobB, the only deacetylase found in bacteria. Here, we demonstrated that CobB plays an important role in the virulence of EHEC O157:H7 and that deletion of significantly decreased the intestinal colonization ability of bacteria.

Z3495, a LysR-Type Transcriptional Regulator Encoded in O Island 97, Regulates Virulence Gene Expression in Enterohemorrhagic O157:H7.

Enterohemorrhagic (EHEC) is an important foodborne pathogen that infects humans by colonizing the large intestine. The genome of EHEC O157:H7 contains 177 unique O islands (OIs). Certain OIs significantly contribute to the heightened virulence and pathogenicity exhibited by EHEC O157:H7.

Glycoengineering directs de novo biomanufacturing of UPEC O21 O-antigen polysaccharide based glycoprotein.

Glycoproteins, in which polysaccharides are usually attached to proteins, are an important class of biomolecules that are widely used as therapeutic agents in clinical treatments for decades. Uropathogenic Escherichia coli (UPEC) O21 has been identified as a serogroup that induces urinary tract infections, with a global increasing number among women and young children. Therefore, there is an urgent need to establish protective vaccines against UPEC infection.

Genomic epidemiological analysis of county-scale Yersinia pestis spread pattern over 50 years in a Southwest Chinese prefecture.

Plague, one of the most devastating infectious diseases in human history, is caused by the bacterium Yersinia pestis. Since the 1950s, the Dehong Dai-Jingpo Autonomous Prefecture (DH) in Yunnan Province, China, has recorded plague outbreaks that have resulted in 1,153 human cases and 379 deaths. The genetic diversity and transmission characteristics of Y.

Neonatal Meningitis-Causing Induces Microglia Activation which Acts as a Double-Edged Sword in Bacterial Meningitis.

Bacterial meningitis is a devastating disease occurring worldwide, with up to half of survivors left with permanent neurological sequelae. Neonatal meningitis-causing (NMEC) is the most common Gram-negative bacillary organism that causes meningitis, particularly during the neonatal period. Here, RNA-seq transcriptional profiles of microglia in response to NMEC infection show that microglia are activated to produce inflammatory factors.

O157:H7 senses microbiota-produced riboflavin to increase its virulence in the gut.

Riboflavin is produced by most commensal bacteria in the human colon, where enterohemorrhagic (EHEC) colonizes and causes diseases. Sensing environmental signals to site-specifically express the type-III secretion system (T3SS), which injects effectors into host cells leading to intestinal colonization and disease, is key to the pathogenesis of EHEC. Here, we reveal that EHEC O157:H7, a dominant EHEC serotype frequently associated with severe diseases, acquired a previously uncharacterized two-component regulatory system , which senses microbiota-produced riboflavin to directly activate the expression of LEE genes encoding the T3SS in the colon.

MlrA, a MerR family regulator in , senses the anaerobic signal in the small intestine of the host to promote bacterial intestinal colonization.

(), one of the most important bacterial pathogens in history, is a gram-negative motile bacterium that causes fatal pandemic disease in humans via oral ingestion of contaminated water or food. This process involves the coordinated actions of numerous regulatory factors. The MerR family regulators, which are widespread in prokaryotes, have been reported to be associated with pathogenicity.

Population genomics of the food-borne pathogen reveals lineage associated pathogenicity-related genetic elements.

is a food-borne pathogen with epidemic potential that causes cholera-like acute gastroenteritis and sometimes extraintestinal infections in humans. However, research on its genetic diversity and pathogenicity-related genetic elements based on whole genome sequences is lacking. In this study, we collected and sequenced 130 strains of from 14 provinces of China, and also determined the susceptibility of 35 of the strains to 30 different antibiotics.

New Genotype of Found in Live Rodents in Yunnan Province, China.

Yunnan Province, China is thought to be the original source of biovar Orientalis of , the causative agent of the third plague pandemic that has spread globally since the end of the 19th century. Although encompassing a large area of natural plague foci, strains have rarely been found in live rodents during surveillance in Yunnan, and most isolates are from rodent corpses and their fleas. In 2017, 10 strains were isolated from seven live rodents and three fleas in Heqing County of Yunnan.

Draft Genome Sequences of Six Yersinia pestis Strains Isolated from a Natural Plague Focus in Mongolia.

In this announcement, we report the draft genome sequences of six strains (biovar Medievalis) that were isolated from the Zamyn-Ude region in Mongolia. These genomes reveal the genetic characteristics of the population circulating in a local plague focus.

Identification of Bredeney Resistant to Third-Generation Cephalosporins in Saudi Arabia.

The rapidly increasing prevalence and spread of antibiotic-resistant worldwide have become a thorny problem that poses a serious threat to human health. It is speculated that antibiotic abuse, frequent traveling, and mass gatherings accelerate this threat. To explore this hypothesis, we investigated 13 isolates from Medina, Saudi Arabia and 15 from China as the control group using typical methods of serotype identification, antibiotic resistance tests, pulsed-field gel electrophoresis (PFGE), and multi-locus sequence typing (MLST).