- [PDF] The ecology, biology and pathogenesis of Acinetobacter spp.: an overview. | Semantic Scholar
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Bacterial adherence was evaluated semi-quantitatively from zero to three 27 based on the following legend:. SPSS version Student t test was used to determine differences between means. Adherence data were c ompa red employing the Mann-Whitney-Wilcoxon test. Correlations of adhesion and increased virulence factor were evaluated by general linear model analysis multiple linear regression.
All the clinical A. Frequencies of the genes among A. The resistance rates to cefepime and imipenem were However, There was no significant correlation between virulence factors and the antibiotic resistance. Based on PCR results, 18 clinical A. There was no significant correlation between virulence factors and ESBL producing isolates. All the 18 isolates attached to the A cells.
The number of adhered bacteria varied from Dispersion of virulence factors and their relevance to various strains of A. Henrichsen and Blom 28 were the first to describe the pili presence on Acinetobacter strains in in A. These pili were involved in adherence to biotic and abiotic surfaces.
A 6-nm think pilus was associated with twitching motility enabling colonization on adjacent surfaces The current study employed surface antigens as virulence factors. These factors are already described as novel vaccine candidates against MDR A. Based on the prevalence and amino acid sequence conservation, the antigens could be classified into three groups with Group I antigens suggesting the most likely vaccine candidates Presence of this conserved and prevalent gene may be attributed to the virulence of A.
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The obtained results were consistent with those of Moriel et al. However, other fimbrial proteins in Groups II and III play a role in adherence and their use in a potential multi-component subunit vaccine cannot be ruled out since they are not highly prevalent or conserved The adhesion of A. Adherence of CsuE -mutant strain rather than the parental strain to a number of epithelial cells could be attributed to the elevated expression of other surface elements such as different pilus types, as in Escherichia coli The current study findings showed that CsuA was more effective in bacterial adherence to host cells.
Biofilm formation by A. Overall observations in the current study indicated that various cell products and structures of A.
[PDF] The ecology, biology and pathogenesis of Acinetobacter spp.: an overview. | Semantic Scholar
In the current investigation, no significant correlation was observed between virulence factor genes and the antibiotic resistance. The current study results did not show any correlation between antibiotic resistance and cell adherence. In conclusion, the current study findings demonstrated that adherence to human epithelial cells is a general feature of A.
Further structural, physiological, and genetic studies are necessary to clarify the role of ABAYEfimbrial protein in the pathogenesis of A. Role of fibronectin in the adhesion of Acinetobacter baumannii to host cells. PLoS One. Bacterial interactions with the host epithelium. Cell Host Microbe. Bacterial adhesins in host-microbe interactions. Front Public Health. Attributable mortality of Acinetobacter baumannii infections in critically ill patients: a systematic review of matched cohort and case-control studies.
Crit Care. Confronting multidrug-resistant Acinetobacter baumannii: a review. Citations Publications citing this paper. Acinetobacter spp. A comparative study of microbial community and dynamics of Asaia in the brown planthopper from susceptible and resistant rice varieties Abhishek Ojha , Wenqing Zhang.
A culture-dependent and metagenomic approach of household drinking water from the source to point of use in a developing country Sungwoo Bae , Colleen M. Scanlan Lyons , Nora Hazel Onstad.
References Publications referenced by this paper. Multidrug-resistant Acinetobacter baumannii: mechanisms of virulence and resistance. N Claire Gordon , David W. Annu Rev Microbiol. A ferric citrate-specific cytoplasmic membrane transport component is absent in P. Citrate-mediated iron uptake in Pseudomonas aeruginosa : involvement of the citrate-inducible FecA receptor and the FeoB ferrous iron transporter.
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- The ecology, biology and pathogenesis of Acinetobacter spp.: an overview.?
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ACS Chem Biol. Similar cooperation between the FeoB transporter and the citrate-promoted Fe acquisition has been suggested in other species, such as H. Isolation and characterization of FecA- and FeoB-mediated iron acquisition systems of the spirochete Leptospira biflexa by random insertional mutagenesis. Genes encoding for the baumanoferrin biosynthetic gene cluster found in A. Evolution of a pathogen: a comparative genomics analysis identifies a genetic pathway to pathogenesis in Acinetobacter. PLoS One. However, similar relationships between these siderophores and the Feo system are yet unknown.
Transcriptome analysis of A. This motivated us to study the genetic context of those genes. The Feo systems found in A. Whole transcriptome analysis of Acinetobacter baumannii assessed by RNA-sequencing reveals different mRNA expression profiles in biofilm compared to planktonic cells. However, when the transcriptional profile of A. Investigation of the human pathogen Acinetobacter baumannii under iron limiting conditions. BMC genomics.
The importance of the feoA gene was first evidenced in fitness. Significant differences were also found in biofilm production or cellular attachment. The deletion of feoA demonstrated that this gene was involved is those mechanisms used by A. This enzyme frequently uses Fe as metal cofactor to catalyze the detoxification of superoxide [ 63 Miller AF. Superoxide dismutases: ancient enzymes and new insights.
Fitness is usually defined as the capacity for survival and reproduction in a particular environment [ 64 Lenski RE. Quantifying fitness and gene stability in microorganisms. Most pathogens use of a combination of two properties to cause disease: i toxicity, the degree to which a substance causes harm, and ii invasiveness, the ability to penetrate into the host and spread [ 48 Beceiro A , Tomas M , Bou G. Brock biology of microorganisms. Bacterial adaptation to oxidative stress: implications for pathogenesis and interaction with phagocytic cells.
Moreover, complementation experiments were performed in order to better demonstrate the role of feoA in virulence. Accordingly, those assays in which fitness does not play a relevant role, such as biofilm production, were performed including the complemented strains. These assays clearly demonstrated that the complementation is possible and indeed restored the original phenotype. However, those assays where fitness is a limiting factor, such as the in vivo assays in animal models, were carried out without the complemented strains.
In a recent screening of genes involved in bacterial survival of A. Between them, two genes belonged to iron uptake systems, the fepA and the feoB genes, supporting the role of these systems in the A. However, no in vivo assays were performed on the study to confirm the results. In the present study, the implication of FeoA in the pathogenesis of A. In the first model, previously validated to study A. Contribution of the A. Both assays with invertebrate and vertebrate hosts reflected similar effects.
Taken together these observations indicate that the feoA gene of A. However, virulence of A. Definitively, in the present study we demonstrated that the FeoA protein is needed for the full virulence phenotype of the strain ATCC of A. Bacterial strains and plasmids used in this work. Table 3. Susceptibility to oxidative stress generated by paraquat. Table 4. Mortality of G. Table 5. An experimental pneumonia model was used to describe the transcriptome of the ATCC strain during the course of the infection. The number of bacteria present in the inoculum was checked by plate counting in LB agar plates.
Briefly, mice anesthetized with an oral suspension of sevoflurane Zoetis, NADA — were suspended by their incisors on a board in a semi-vertical position. The efficacy of the intratracheal inoculation was confirmed by using an endoscope on the oral cavity. All experiments were done with the approval of and in accordance with regulatory guidelines and standards set by the Animal Ethics Committee CHUAC, Spain, project code P82 , in accordance with the Helsinki Declaration of To characterize the complete transcriptomes of the studied samples, mRNA libraries from in vivo and in vitro samples obtained as explained above were prepared following the Truseq RNA sample preparation protocols from Illumina Inc.
Three biological replicates were studied for each sample. Short reads were aligned against the complete genome of A.
An allelic exchange system for compliant genetic manipulation of the select agents Burkholderia pseudomallei and Burkholderia mallei. The gyrB gene was used as a positive control.