scholarly journals Interaction of Acinetobacter baumannii with Human Serum Albumin: Does the Host Determines the Outcome?

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 833
Author(s):  
Camila Pimentel ◽  
Casin Le ◽  
Marisel R. Tuttobene ◽  
Tomas Subils ◽  
Krisztina M. Papp-Wallace ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Human Serum Albumin ◽  
Quorum Sensing ◽  
Serum Albumin ◽  
Human Serum ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Model Systems ◽  
Expression Levels ◽  
Multiple Drugs

Acinetobacter baumannii has become a serious threat to human health due to its extreme antibiotic resistance, environmental persistence, and capacity to survive within the host. Two A. baumannii strains, A118 and AB5075, commonly used as model systems, and three carbapenem-resistant strains, which are becoming ever more dangerous due to the multiple drugs they can resist, were exposed to 3.5% human serum albumin (HSA) and human serum (HS) to evaluate their response with respect to antimicrobial resistance, biofilm formation, and quorum sensing, all features responsible for increasing survival and persistence in the environment and human body. Expression levels of antibiotic resistance genes were modified differently when examined in different strains. The cmlA gene was upregulated or downregulated in conditions of exposure to 3.5% HSA or HS depending on the strain. Expression levels of pbp1 and pbp3 tended to be increased by the presence of HSA and HS, but the effect was not seen in all strains. A. baumannii A118 growing in the presence of HS did not experience increased expression of these genes. Aminoglycoside-modifying enzymes were also expressed at higher or lower levels in the presence of HSA or HS. Still, the response was not uniform; in some cases, expression was enhanced, and in other cases, it was tapered. While A. baumannii AB5075 became more susceptible to rifampicin in the presence of 3.5% HSA or HS, strain A118 did not show any changes. Expression of arr2, a gene involved in resistance to rifampicin present in A. baumannii AMA16, was expressed at higher levels when HS was present in the culture medium. HSA and HS reduced biofilm formation and production of N-Acyl Homoserine Lactone, a compound intimately associated with quorum sensing. In conclusion, HSA, the main component of HS, stimulates a variety of adaptative responses in infecting A. baumannii strains.

scholarly journals Interplay between meropenem and human serum albumin on expression of carbapenem resistance genes and natural competence in Acinetobacter baumannii

2021 ◽  
Author(s):  
Camila Pimentel ◽  
Casin Le ◽  
Marisel Romina Tuttobene ◽  
Tomas Subils ◽  
Brent Nishimura ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Natural Transformation ◽  
Natural Competence ◽  
Expression Levels ◽  
Carbapenem Resistant ◽  
Synergistic Enhancement

Acinetobacter baumannii A118, a mostly susceptible strain, and AB5075, carbapenem-resistant, were cultured in L-broth or L-broth with different supplements: 3.5% human serum albumin (HSA), human serum (HS), meropenem, or meropenem plus 3.5% HSA. Natural transformation levels were enhanced in A. baumannii A118 and AB5075 cultured in medium supplemented with 3.5 % HSA. Addition of meropenem plus 3.5% HSA caused synergistic enhancement of natural transformation inA. baumannii A118. Medium containing 3.5% HSA or meropenem enhanced the expression levels of the competence and type IV pilus associated genes. The combination meropenem plus 3.5% HSA produced a synergistic augmentation in the expression levels of many of these genes. The addition of HS, which has a high content of HSA, was also an inducer of these genes. Cultures in medium supplemented with HS or 3.5% HSA also affected resistance genes, which were expressed at higher or lower levels depending on the modification required to enhance resistance. The inducing or repressing activity of these modulators also occurred in three more carbapenem-resistant strains tested. An exception was the A. baumanniiAMA16 blaNDM-1 gene, which was repressed in the presence of 3.5% HSA. In conclusion, HSA produces an enhancement of natural transformation and a modification in expression levels of competence genes and antibiotic resistance. Furthermore, when HSA is combined with carbapenems, which may produce stronger cellular stress, the A. baumannii responds increasing the levels of expression of genes involved in natural competence. This process may favor the acquisition of foreign DNA and accelerate evolution.

scholarly journals Human Pleural Fluid and Human Serum Albumin Modulate the Behavior of a Hypervirulent and Multidrug-Resistant (MDR) Acinetobacter baumannii Representative Strain

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 471
Author(s):  
Camila Pimentel ◽  
Casin Le ◽  
Marisel R. Tuttobene ◽  
Tomas Subils ◽  
Jasmine Martinez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Acinetobacter Baumannii ◽  
Pleural Fluid ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
The United States ◽  
World Health

Acinetobacter baumannii is a nosocomial pathogen capable of causing serious infections associated with high rates of morbidity and mortality. Due to its antimicrobial drug resistance profile, A. baumannii is categorized as an urgent priority pathogen by the Centers for Disease Control and Prevention in the United States and a priority group 1 critical microorganism by the World Health Organization. Understanding how A. baumannii adapts to different host environments may provide critical insights into strategically targeting this pathogen with novel antimicrobial and biological therapeutics. Exposure to human fluids was previously shown to alter the gene expression profile of a highly drug-susceptible A. baumannii strain A118 leading to persistence and survival of this pathogen. Herein, we explore the impact of human pleural fluid (HPF) and human serum albumin (HSA) on the gene expression profile of a highly multi-drug-resistant strain of A. baumannii AB5075. Differential expression was observed for ~30 genes, whose products are involved in quorum sensing, quorum quenching, iron acquisition, fatty acid metabolism, biofilm formation, secretion systems, and type IV pilus formation. Phenotypic and further transcriptomic analysis using quantitative RT-PCR confirmed RNA-seq data and demonstrated a distinctive role of HSA as the molecule involved in A. baumannii’s response.

Evaluation of type II toxin-antitoxin systems, antibiotic resistance profiles, and biofilm quorum sensing genes in Acinetobacter baumannii isolates in Iraq

2020 ◽  
Vol 20 ◽  
Author(s):  
Mohammed F. Al Marjania ◽  
Ebrahim Kouhsari ◽  
Fatima S. Ali ◽  
Sawsan H. Authman
Keyword(s):  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Bacterial Genome ◽  
Bacterial Toxin ◽  
Clinical Samples ◽  
Disk Diffusion Test ◽  
Molecular Determinants ◽  
Imipenem Resistance

Background: Bacterial Toxin-Antitoxin (TAs) systems are extensive two-component elements in the bacterial genome, which involved in many key biological functions including growth arrest, survival, biofilm formation, plasmid maintenance, defense against phages, persistence and virulence. Aim: This study aimed to assess the molecular determinants involved in TAs, biofilm quorum sensing, and antibiotic resistance profiles in Acinetobacter baumannii isolated from Baghdad`s hospitals in Iraq. Methods: A total of 127 A. baumannii isolates were collected from 2160 different clinical samples. The antimicrobial susceptibility test was performed using disk diffusion test. All isolates were characterized for molecular determinants involved in TAs and biofilm formation using the well-known PCR-based sequencing assay. Results: A high multi-drug resistant (MDR) (96.06%; 122/127 ) and imipenem resistance (84.25%; 107/127 ) rates were observed from A.baumannii isolates. Results showed the presence of rhlIR gene in three isolates (2.36%), and lasIR gene appeared in two isolates (1.57%) isolates, whilst, mazEF, ccdAB, and relBE genes have not detected among isolates. Conclusion: A high MDR and imipenem resistance rates within a low prevalence of rhlIR, and lasIR genes could be found in clinical A. baumannii isolates from some of Iraqi hospitals.

Effects of human serum albumin, ibuprofen and N-acetyl-l-cysteine against biofilm formation by pathogenic Escherichia coli strains

2010 ◽  
Vol 76 (2) ◽  
pp. 165-170 ◽  
Author(s):  
P. Naves ◽  
G. del Prado ◽  
L. Huelves ◽  
V. Rodríguez-Cerrato ◽  
V. Ruiz ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Biofilm Formation ◽  
Pathogenic Escherichia Coli

scholarly journals Human serum albumin alters specific genes that can play a role in survival and persistence in Acinetobacter baumannii

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Brettni Quinn ◽  
Nyah Rodman ◽  
Eugenio Jara ◽  
Jennifer S. Fernandez ◽  
Jasmine Martinez ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Acinetobacter Baumannii

scholarly journals Human Pleural Fluid and Human Serum Albumin Modulate the Behavior of a Hypervirulent and Multidrug-Resistant (Mdr) Acinetobacter baumannii Representative Strain

2021 ◽  
Author(s):  
Camila Pimentel ◽  
Casin Le ◽  
Marisel R. Tuttobene ◽  
Tomas Subils ◽  
Jasmine Martinez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Acinetobacter Baumannii ◽  
Pleural Fluid ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
The United States ◽  
World Health

Acinetobacter baumannii is a nosocomial pathogen capable of causing serious infections associated with high rates of morbidity and mortality. Due to its antimicrobial drug resistance profile, A. baumannii is categorized as an urgent priority pathogen by the Centers for Disease Control and Prevention in the United States and priority group 1 critical microorganism by the World Health Organization. Understanding how A. baumannii adapts to different host environments may provide critical insights into strategically targeting this pathogen with novel antimicrobial and biological therapeutics. Exposure to human fluids was previously shown to alter the gene expression profile of a highly drug susceptible A. baumannii strain A118 leading to persistence and survival of this pathogen. Herein, we explore the impact of human pleural fluid (HPF) and human serum albumin (HSA) on the gene expression profile of a highly multi-drug resistant strain of A. baumannii AB5075. Differential expression was observed for ~30 genes, whose products are involved in quorum sensing, quorum quenching, iron acquisition, fatty acid metabolism, biofilm formation, secretion systems and type IV pilus formation. Phenotypic and further transcriptomic analysis using quantitative RT-PCR confirmed RNA-seq data and pointed out a distinctive role of HSA as the molecule involved in A. baumannii response.

II. Lokalisation der Placenta mit 113Inm- Human-Serum-Albumin

1969 ◽  
Vol 08 (01) ◽  
pp. 15-21 ◽  
Author(s):  
K. E. Scheer ◽  
J. Heep ◽  
W. Maier-Borst ◽  
W. J. Lorenz ◽  
H. Sinn ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Vena Cava ◽  
Placenta Praevia ◽  
Wird Eine

ZusammenfassungNach tierexperimentellen Voruntersuchungen wurde die Placentographie mit trägerfreiem 113Inm -HSA als klinische Methode eingeführt. Vor Amniocentesen und bei Verdacht auf Placenta praevia werden Placentographien geschrieben. Den Schwangeren wird eine Aktivität von 500 μCi in die Cubitalvene injiziert. Die der Aktivität entsprechende Indiummenge ist kleiner als 0,1 ng. Die fetale Strahlenbelastung liegt unter lOmrad. Bei Anwendung von 113Inm-HSA entfällt eine Blockade der mütterlichen und fetalen Schilddrüsen. Die genaue Abgrenzung einer Placenta praevia wird nicht durch eine Blasenaktivität beeinträchtigt.Es wurden bisher 19 Placentalokalisationen durchgeführt. In allen Fällen konnte der Placentasitz eindeutig festgestellt werden. Bedingt durch die lange Liegezeit beim Aufnehmen eines Szintigramms kam es in zwei Fällen zu einem Vena-Cava-Kompressions-Syndrom. Zur Verhinderung dieser klinischen Zwischenfälle werden inzwischen Placentographien mit der Anger-Kamera aufgenommen. Mit Hilfe des divergierenden Kollimators konnte der gesamte Abdominalbereich erfaßt werden. Die Aufnahmezeit konnte auf 7 — 10 Minuten verkürzt werden. Die intravenöse injizierte Aktivität betrug bei dieser Methode ebenfalls 500 μCi. Der diagnostische Aussagewert der Kamerabilder ist szintigraphischen Aufnahmen gleichwertig.

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