Molecular Screening of Virulence Genes in Extraintestinal Pathogenic<i>Escherichia coli</i>Isolated from Human Blood Culture in Brazil

Koga, Vanessa Lumi; Tomazetto, Geizecler; Cyoia, Paula Signolfi; Neves, Meiriele S.; Vidotto, Marilda Carlos; Nakazato, Gerson; Kobayashi, Renata Katsuko Takayama

doi:10.1155/2014/465054

Cited by 46 publications

(53 citation statements)

References 33 publications

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“…With respect to median PAIs ( Figure 3A and B), there was very close convergence between clinical and environmental isolates. These results substantiate the probability that environmental isolates are not commensals, which came in accordance with Koga et al (39).…”

Section: Discussionsupporting

confidence: 92%

Virulence Characteristics, Serotyping and Phylogenetic Typing of Clinical and Environmental Escherichia coli Isolates

El-Shaer

Abdel-Rhman

Barwa

et al. 2018

Jundishapur J Microbiol

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Background: Pathogenic Escherichia coli is responsible for serious diseases; i.e.: Peritonitis, colitis, and urinary tract infections (UTIs) and even cancer, resulting in human morbidity and mortality. Environmental strains are increasingly spreading through food and dairy products, contributing to the pathogenetic burden of E. coli infections. Objectives: This study was performed to compare phylogeny, virulence factors, pathogenicity islands (PAIs), and pathotypes inbetween clinical and environmental E. coli isolates. Methods: A total of 105 clinical (72) and environmental (33) E. coli isolates were collected. All isolates were subjected to phylogenetic typing using a new quadruplex polymerase chain reaction (PCR). Wide array of virulence genes (VGs) and PAI markers were assessed for both subtypes, as well as, the distribution of different pathotypes among the phylogenetic groups. Results: Seven phylogenetic groups were detected; clinical isolates were more prevalent in phylogenetic groups B2 (22.2%) and D (23.6%), whereas environmental isolates were in groups A (24.2%) and B1 (60.6%). Majority of VGs were higher in clinical E. coli isolates. Environmental isolates showed higher percentage of some other VGs including; stx2 and hlyA. PAI markers were widespread among both categories, showing high extra-intestinal pathogenic E. coli (ExPEC) PAIs combination in environmental isolates. Enteropathogenic E. coli (EPEC) was the most widespread pathotype in clinical isolates versus enterohemorrhagic E. coli (EHEC) in environmental ones. Conclusions: Escherichia coli pathogenicity armoury was not only confined to clinical isolates, but to environmental ones as well. Therefore, environmental E. coli isolates can serve as reservoirs for transmission of E. coli pathogenicity.

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Section: Discussionsupporting

confidence: 92%

Virulence Characteristics, Serotyping and Phylogenetic Typing of Clinical and Environmental Escherichia coli Isolates

El-Shaer

Abdel-Rhman

Barwa

et al. 2018

Jundishapur J Microbiol

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“…The prevalence of hlyA gene encoding a toxin implicated in tissue damage and dysfunction of local immune responses was found more frequently in phylogenetic group B2. The distribution of this gene in our isolates is in agreement with other reports (21,22). The prevalence of genes encoding the aerobactin and siderophore receptors (iucD and iroN), which confers the ability to take up iron, among isolates belonging to phy-Int J Enteric Pathog.…”

Section: Discussionsupporting

confidence: 92%

Comparison of Virulence Factors Distribution in Uropathogenic E. coli Isolates From Phylogenetic Groups B2 and D

Abdi¹,

Rashki

2014

Int J Enteric Pathog

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Background: Urinary tract infections are a significant health problem, with Escherichia coli as a primary pathogen in approximately 80% of cases. The pathogenesis of E. coli in urinary tract infections is attributed to the production of virulence factors and phylogenetic background groups. Objectives: The aim of this study was to determine differences in prevalence of virulence factors of E. coli isolates from phylogenetic groups B2 and D, collected from patients with urinary tract infections. Materials and Methods: A total of 100 E. coli isolates were identified by conventional biochemical tests from patients with urinary tracts infections (UTIs) in teaching hospitals of Zabol, Iran. DNA was extracted using the boiling method. Analysis of phylogenetic groups, along with detection of virulence factor genes was performed by the multiplex-PCR method. Associations were assessed between type 1 fimberiaencoding gene, siderophore receptor encoding genes and hemolysin encoding gene among 55 B2 group E. coli isolates and 22 D group E. coli isolates. Statistical analysis was performed using the Fisher exact test. Results: Phylogenetic analysis showed that 55 and 22 of 100 isolates belonged to the B2 and D phylogenetic groups, respectively. The hlyA, iroN, iucD and fimH genes were present in 29 (52.72%), 22 (40%), 46 (83.63%) and 55 (100%) isolates belonging to the phylogenetic group B2, whereas in 2 (9.09%), 2 (9.09%), 10 (45.45%) and 22 (100%) isolates belonging to the phylogenetic group D, respectively. The comparison showed that there was a significant difference between the presence of hlyA and iroN genes in isolates belonging to the phylogenetic group B2 and D (P ≤ 0.05). Conclusions: This study determined that strains belonging to group B2 are the most important and abundant E. coli strains causing urinary tract infections.

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“…Our vaccine will diminish, if not ultimately eliminate, pathogenic E. coli with minimal cross-reactivity with the healthy flora, because IroN and IutA antigens targeted within this vaccine are more prevalent among ExPEC than commensal E. coli [40–42]. Regarding the ECP antigen, since it has been shown that in in vitro conditions mimicking the in vivo situation, only virulent E. coli highly produced ECP, whereas commensal E. coli did not [43]; as our vaccine will only target ECP-expressing E. coli in vivo , it would not have effect on non-ECP-expressing commensal E. coli .…”

Section: Discussionmentioning

confidence: 99%

Novel vaccine antigen combinations elicit protective immune responses against Escherichia coli sepsis

Mellata

Mitchell

Schödel³

et al. 2016

Vaccine

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Systemic infections caused by extraintestinal pathogenic Escherichia coli (ExPEC) have emerged as the most common community-onset bacterial infections and are major causes of nosocomial infections worldwide. The management of ExPEC infections has been complicated by the heterogeneity of ExPEC strains and the emergence of antibiotic resistance, thus their prevention through vaccination would be beneficial. The protective efficacy of four common ExPEC antigen candidates composed of common pilus antigens EcpA and EcpD and iron uptake proteins IutA and IroN, were tested by both active and passive immunization in lethal and non-lethal murine models of sepsis. Additionally, antibody raised to a synthetic form of a conserved surface polysaccharide, β-(1–6)-linked poly-N-acetylglucosamine (dPNAG) containing 9 monomers of (non-acetylated) glucosamine (9GlcNH2) conjugated to tetanus toxoid TT (9GlcNH2-TT) was tested in passive immunization protocols. Active immunization of mice with recombinant antigens EcpA, EcpD, IutA or IroN elicited high levels of total IgG antibody of IgG1/IgG2a isotypes, and were determined to be highly protective against E. coli infection in lethal and non-lethal sepsis challenges. Moreover, passive immunization against these four antigens resulted in significant reductions of bacteria in internal organs and blood of the mice, especially when the challenge strain was grown in iron-restricted media. Inclusion of antibodies to PNAG increased the efficacy of the passive immunization under conditions where the challenge bacteria were grown in LB medium but not in iron-restricted media. The information and data presented are the first step toward the development of a broadly protective vaccine against sepsis-causing E. coli strains.

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Molecular Screening of Virulence Genes in Extraintestinal PathogenicEscherichia coliIsolated from Human Blood Culture in Brazil

Cited by 46 publications

References 33 publications

Virulence Characteristics, Serotyping and Phylogenetic Typing of Clinical and Environmental Escherichia coli Isolates

Virulence Characteristics, Serotyping and Phylogenetic Typing of Clinical and Environmental Escherichia coli Isolates

Comparison of Virulence Factors Distribution in Uropathogenic E. coli Isolates From Phylogenetic Groups B2 and D

Novel vaccine antigen combinations elicit protective immune responses against Escherichia coli sepsis

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