was initially isolated from an asymptomatic black howler monkey () in a routine fecal culture examination. Fecal cultures from other individuals in this group and an adjacently housed black-headed spider monkey () group recovered from all but one of the individuals sampled (1.1 spider monkeys and 2.
View Article and Find Full Text PDFClostridioides difficile is a Gram-positive, anaerobic, and spore-forming bacterial member of the human gut microbiome. The primary virulence factors of C. difficile are toxin A and toxin B.
View Article and Find Full Text PDFThe threat of antibiotic-resistant bacteria to public health may originate from public restrooms. To better understand the community burden of antimicrobial-resistant and sequence type complex 131 (STc131) in the public restroom, we performed a surveillance in public restrooms in southern Taiwan. Swabs were sampled from randomly selected public restrooms in Tainan, Taiwan in 2019.
View Article and Find Full Text PDFAcanthamoeba castellanii is a free-living, pathogenic ameba found in the soil and water. It invades the body through ulcerated skin, the nasal passages, and eyes and can cause blinding keratitis and granulomatous encephalitis. However, the mechanisms underlying the opportunistic pathogenesis of A.
View Article and Find Full Text PDFspecies are gram stain-negative rods that are facultatively anaerobic; they have been isolated from wetland soil. Clinical infection caused by this genus is rarely reported. We report the case of an 84-year-old woman with chronic renal disease and hypertension who acquired lung infection and septicemia in Southern Taiwan.
View Article and Find Full Text PDFClostridioides difficile is a gram-positive, spore-forming anaerobic bacterium, and the leading cause of antibiotic-associated diarrhea worldwide. During C. difficile infection, spores germinate in the presence of bile acids into vegetative cells that subsequently colonize the large intestine and produce toxins.
View Article and Find Full Text PDFBackground: Flagella-mediated motility is both a crucial virulence determinant of Helicobacter pylori and a factor associated with gastrointestinal diseases. Flagellar formation requires flagellins to be glycosylated with pseudaminic acid (Pse), a process that has been extensively studied. However, the transfer of Pse to flagellins remains poorly understood.
View Article and Find Full Text PDFEnterohemorrhagic Escherichia coli (EHEC), an enteropathogen that colonizes in the intestine, causes severe diarrhea and hemorrhagic colitis in humans by the expression of the type III secretion system (T3SS) and Shiga-like toxins (Stxs). However, how EHEC can sense and respond to the changes in the alimentary tract and coordinate the expression of these virulence genes remains elusive. The T3SS-related genes are known to be regulated by the locus of enterocyte effacement (LEE)-encoded regulators, such as Ler, as well as non-LEE-encoded regulators in response to different environmental cues.
View Article and Find Full Text PDFNon-typhoidal and Typhoidal are bacterial pathogens source of worldwide and major disease burden. Virulent determinants of specific serovars belonging to non-typhoidal have been extensively studied in different models, yet the pathogenesis of this group of bacteria and the development of clinical symptoms globally remains underexplored. Herein, we implemented microbiological and molecular procedures to investigate isolate virulence traits and molecular diversity, likely in association with disease severity.
View Article and Find Full Text PDFBackground: Most drug-resistant isolates in dogs come from diseased dogs. Prior to this study, the prevalence and risk factors of fecal carriage drug-resistant and epidemic clone sequence type (ST) 131 (including subtypes) isolates in dogs were unknown.
Methods: Rectal swabs were used for isolation from 299 non-infectious dogs in a veterinary teaching hospital in Taiwan.
Acanthamoeba castellanii is a protist that has a high predation efficiency for bacteria in a number of monoxenic culture experiments. However, the role of A. castellanii in the microbial community is still unknown because of the lack of studies on multiple-species interactions.
View Article and Find Full Text PDFis an emerging human pathogen which causes fast and severe infections worldwide. Under the gradual pressure of lacking useful antibiotics, finding a new strategy against infection is urgent. To understand its pathogenesis, we created an AAK1 mini-Tn10 transposon library to study the mechanism of infection.
View Article and Find Full Text PDFis a Gram-positive, spore-forming bacterium, and major cause of nosocomial diarrhea. Related studies have identified numerous factors that influence virulence traits such as the production of the two primary toxins, toxin A (TcdA) and toxin B (TcdB), as well as sporulation, motility, and biofilm formation. However, multiple putative transcriptional regulators are reportedly encoded in the genome, and additional factors are likely involved in virulence regulation.
View Article and Find Full Text PDFThis study investigates the evolution of an sequence type 219 clone in a patient with recurrent urinary tract infection, comparing isolate EC974 obtained prior to antibiotic treatment and isolate EC1515 recovered after exposure to several β-lactam antibiotics (ceftriaxone, cefixime, and imipenem). EC974 had a smooth colony morphology, while EC1515 had a rough colony morphology on sheep blood agar. RAPD-PCR analysis suggested that both isolates belonged to the same clone.
View Article and Find Full Text PDFThe enteric pathogen enterohemorrhagic Escherichia coli (EHEC) is responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) worldwide. Several molecular mechanisms have been described for the pathogenicity of EHEC; however, the role of bacterial metabolism in the virulence of EHEC during infection in vivo remains unclear. Here we show that aerobic metabolism plays an important role in the regulation of EHEC virulence in Caenorhabditis elegans.
View Article and Find Full Text PDFis a Gram-positive, spore-forming anaerobic human gastrointestinal pathogen. infection (CDI) is a major health concern worldwide, with symptoms ranging from diarrhea to pseudomembranous colitis, toxic megacolon, sepsis, and death. CDI onset and progression are mostly caused by intestinal dysbiosis and exposure to spores.
View Article and Find Full Text PDFBackground: is a Gram-positive anaerobe and the leading cause of antibiotic-associated diarrhea worldwide. The emergence of ribotype 027 (RT027) strains is associated with increased incidence of infection and mortality. To further understand the relationship between NCKUH-21, a RT027 strain isolated from a patient in Taiwan, and other RT027 strains, we performed whole-genome shotgun sequencing on NCKUH-21 and comparative genomic analyses.
View Article and Find Full Text PDFis considered to be one of the major cause of infectious diarrhea in healthcare systems worldwide. Symptoms of infection are caused largely by the production of two cytotoxins: toxin A (TcdA) and toxin B (TcdB). Vaccine development is considered desirable as it would decrease the mounting medical costs and mortality associated with infections.
View Article and Find Full Text PDFCsrA has been shown to positively control the expression of flagella-related genes, including and , through regulating expression of an alternative sigma factor RpoN in J99. Here, we aimed to characterize the CsrA regulatory system by comparative transcriptomic analysis carried out with RNA-seq on strain J99 and a mutant. Fifty-three genes in the mutant were found to be differentially expressed compared with the wild-type.
View Article and Find Full Text PDFEnterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important foodborne pathogen causing severe diseases in humans worldwide. Currently, there is no specific treatment available for EHEC infection and the use of conventional antibiotics is contraindicated. Therefore, identification of potential therapeutic targets and development of effective measures to control and treat EHEC infection are needed.
View Article and Find Full Text PDFBioinformatics analysis was used to search for unknown genes that might influence the phenotypic presentations of enterohaemorrhagic Escherichia coli (EHEC). By so doing and using the known genomic data from EHEC O157 : H7 and K-12, it has been deduced that genes Z4863 to Z4866 of EHEC do not exist in K-12 strains. These four gene sequences have low degrees of homology (18-40 % amino acid identities) to a set of genes in K-12, which have been known to encode fatty acid biosynthesis enzymes.
View Article and Find Full Text PDFEnterohaemorrhagic Escherichia coli O157:H7 (EHEC) carries a pathogenic island LEE that is consisted mainly of five polycistronic operons. In the lee3 operon, mpc is the first gene and has been reported to down regulate the type-3 secretion system of EHEC when its gene product is over-expressed. Furthermore, mpc has been suggested to have a regulation function via translation but the mechanism remains unclear.
View Article and Find Full Text PDF