Several genes involved in the lipopolysaccharide (LPS) biosynthetic pathway have been shown to affect the expression or activity of Escherichia coli hemolysin (Hly), a secreted cytotoxin that is the prototype of the RTX family of toxins. To further study this relationship, E. coli K-12 strains harboring mutations in the LPS biosynthetic genes rfaS, rfaQ, rfaJ, rfaP, and rfaC were transformed wi...

BACKGROUND Uropathogenic Escherichia coli O- Serogroups with their virulence factors are the most prevalent causes of UTIs. OBJECTIVES The present investigation was performed to study the virulence factors and O-Serogroups profiles of UPEC isolated from Iranian pediatric patients. PATIENTS AND METHODS This cross sectional investigation was performed on 100 urine samples collected from hospi...

The hemolytic phenotype in Escherichia coli is determined by four genes. Two (hlyC and hlyA) determine the synthesis of a hemolytically active protein which is transported across the cytoplasmic membrane. The other two genes (hlyBa and hlyBb) encode two proteins which are located in the outer membrane and seem to form a specific transport system for hemolysin across the outer membrane. The prim...

Adhesion of bacteria to the glycosylated surface of their target cells is typically mediated by fimbrial lectins, exposed on the bacterial surface. Among the best-investigated and most important fimbriae are type 1 fimbriae, for which α-d-mannopyranoside-specificity has been described. This carbohydrate specificity is mediated by the type 1 fimbrial lectin FimH. In this account, we have employe...

Positive selection in the two-domain type 1 pilus adhesin FimH enhances Escherichia coli fitness in urinary tract infection (UTI). We report a comprehensive atomic-level view of FimH in two-state conformational ensembles in solution, composed of one low-affinity tense (T) and multiple high-affinity relaxed (R) conformations. Positively selected residues allosterically modulate the equilibrium b...

PURPOSE To characterize the prevalence of hemolytic Shiga toxin-producing Escherichia coli (STEC) with a multidrug-resistant pattern in different age groups in Abeokuta, Nigeria. METHODS Nonrepetitive E. coli isolates were collected from 202 subjects with or without evidence of diarrhea. Each isolate was biochemically identified and antimicrobial susceptibility testing was performed using the...

A 5' nuclease assay has been developed to detect viable Listeria monocytogenes. The assay targets the hemolysin A (hlyA) transcript, which is found only in L. monocytogenes. The single-tube, reverse transcriptase (RT), fluorogenic probe-based assay was formatted by using Tth DNA polymerase whose activity was modulated by using the manganese-chelating morpholinepropanesulfonic acid (MOPS) buffer...

HlyU, a transcriptional regulator common in many Vibrio species, activates the hemolysin gene hlyA in Vibrio cholerae, the rtxA1 operon in Vibrio vulnificus and the genes of plp-vah1 and rtxACHBDE gene clusters in Vibrio anguillarum. The protein is also proposed to be a potential global virulence regulator for V. cholerae and V. vulnificus. Mechanisms of gene control by HlyU in V. vulnificus an...

Foodborne diseases and infection caused by associated pathogens is a public health concern. Majority of the investigations focus on common foodborne like Vibrio parahaemolyticus, Escherichia coli, Listeria monocytogenes, Shigella, Salmonella Staphylococcus aureus. Limited knowledge has been accounted Klebsiella pneumoniae. Presence multidrug-resistant K. pneumoniae in food supply disturbing. He...