scholarly journals Distribution of Four Biofilm Associated Gene among A. baumannii by in Silico-PCR

2021 ◽  
pp. 317-324
Author(s):  
J. D. Monesh Babu ◽  
A. S. Smiline Girija ◽  
P. Sankar Ganesh ◽  
J. Vijayashree Priyadharsini
Keyword(s):  
Acinetobacter Baumannii ◽  
In Silico ◽  
Biofilm Formation ◽  
Experimental Validation ◽  
Pcr Amplification ◽  
Opportunistic Pathogen ◽  
Clinical Strains ◽  
Oral Biofilms ◽  
Different Strains ◽  
In Silico Pcr

Background: A.baumannii is an opportunistic pathogen known for its efficient biofilm formation that is attributed for its virulence. Acinetobacter baumannii is an inhabitant of oral biofilms as well. Many gene operons are involved in the biofilm formation that need to be monitored frequently. Aim: The aim of the present study was to detect the distribution of four biofilm associated genes among A.baumannii. Materials and Methods: Four biofilm forming genes viz., bfms, ptk, pgaB, and fimH of A.baumannii were selected. Forward and reverse primers of those four genes were used for in-silico PCR amplification. 19 strains of A.baumannii set as default on the server were chosen and the amplicon bands were observed Results: The present investigation documents the distribution of four vital biofilm associated gene among 19 different strains of A.baumannii among which bfms was distributed at a higher frequency followed by pgaB and ptk Conclusion: The finding of the study suggests the presence of pgaB, bfms, ptk among the 19 different strains of A.baumannii. However further experimental validation must be done to frequently monitor the presence of the genes among the clinical strains of A.baumannii.

scholarly journals Distribution of Biofilm-associated Genes among Acinetobacter baumannii by in-silico PCR

2021 ◽  
pp. 140-149
Author(s):  
A. Aldrin Joshua ◽  
A. S. Smiline Girija ◽  
P. Sankar Ganesh ◽  
J. Vijayashree Priyadharsini
Keyword(s):  
Acinetobacter Baumannii ◽  
In Silico ◽  
Target Genes ◽  
Multidrug Resistant ◽  
Pcr Analysis ◽  
Evolutionary Analysis ◽  
Ompa Gene ◽  
Clinical Strains ◽  
Tract Infections ◽  
In Silico Pcr

Background: Acinetobacter baumannii is a coccobacillus that is Gram negative, non motile, non fermentative and oxidase negative. It is the most common and successful nosocomial pathogen recognised by WHO. This dreadful pathogen causes urinary tract infections, ventilator associated pneumonia (VAP), bacteremia, etc., These infections are most common in hospital wards especially Intensive Care Unit (ICU). The infections are due to biofilm formation by the virulent genes of A. baumannii, and the common biofilm-associated genes of A. baumannii were bap, csuE, fimH, epsA, bfmS, ptk, pgaB, ompA, blaPER-1. Among these, bap, epsA and ompA genes are highly prevalent among the clinical strains of A. baumannii. Aim:  To detect the three vital biofilm-associated genes of A. baumannii by in-silico PCR analysis. Materials and Methods: 19 isolates of A. baumannii were selected and 3 target genes, namely epsA, ompA and bap gene were used for the amplification process through in-silico PCR simulation tools. Evolutionary analysis was done for the ompA gene. Results: The epsA gene was expressed in 10.52% of the total strains selected with the highest occurrence of ompA gene as 57.89%. bap gene was not observed from the study strains included. From evolutionary analysis based on ompA distributed strains, the Acinetobacter baumannii SDF and Acinetobacter baumannii BJAB0715 might be the parental strains where the evolution of strains would have started. Through successive generations, the Acinetobacter baumannii MDR-ZJ06 and Acinetobacter baumannii TYTH-1 had become the multidrug resistant strains present in the environment. Conclusion: The findings of the study confirms the distribution of epsA and ompA genes among the 19 different strains of A. baumannii. The study suggests periodical monitoring of biofilm based virulence genes among the clinical strains and to curtail the A. baumannii infections.

scholarly journals Detection of Drug Resistant Genes among A. baumannii by In silico PCR Method

2021 ◽  
pp. 242-253
Author(s):  
A. Roshan ◽  
A. S. Smiline Girija ◽  
P. Sankar Ganesh ◽  
J. Vijayashree Priyadharshini
Keyword(s):  
Multidrug Resistance ◽  
Resistance Genes ◽  
In Silico ◽  
Pcr Amplification ◽  
Opportunistic Pathogen ◽  
World Health ◽  
Drug Resistant ◽  
Resistant Genes ◽  
In Silico Pcr ◽  
Multidrug Resistance Genes

Background: Acinetobacter baumannii is a gram-negative bacterium classified as an opportunistic pathogen in humans by the World Health Organization. Different genetic determinants contribute to multidrug resistance, and transform it as a nosocomial pathogen. Aim: Using in-silico PCR, this analysis aims to characterize the 13 distinct drug resistant genes found in 19 virulent A.baumannii strains. Materials & Methods: There were 11 A.baumannii multidrug resistance genes chosen. In-silico PCR amplification was performed using forward and reverse primers from the 11 genes described in previous research. The amplicon bands were detected in 19 strains of A.baumannii that were set as default on the server. Results: Among the 13 multidrug resistance genes studied, tet A, tet B, Sul 1, Sul 2, DfrA1,  ISAba-1 and ISAba-125 were detected among the 19 virulent strains of ​A.baumannii​. Conclusion: The findings of the study documents the frequency of tet A, tet B, Sul 1, Sul 2, DfrA1, ISAba-1 and ISAba-125 like from the selected strains of A. baumannii. However, more experimental validation is needed in order to conduct routine surveillance on drug-resistant A. baumannii strains in hospital settings.

scholarly journals Lon Protease Has Multifaceted Biological Functions inAcinetobacter baumannii

2018 ◽  
Vol 201 (2) ◽  
Author(s):  
Carly Ching ◽  
Brendan Yang ◽  
Chineme Onwubueke ◽  
David Lazinski ◽  
Andrew Camilli ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Developmental Process ◽  
Cell Envelope ◽  
Opportunistic Pathogen ◽  
Lon Protease ◽  
Content Type ◽  
Hospital Acquired Infections ◽  
Biofilm Development ◽  
Hospital Acquired

ABSTRACTAcinetobacter baumanniiis a Gram-negative opportunistic pathogen that is known to survive harsh environmental conditions and is a leading cause of hospital-acquired infections. Specifically, multicellular communities (known as biofilms) ofA. baumanniican withstand desiccation and survive on hospital surfaces and equipment. Biofilms are bacteria embedded in a self-produced extracellular matrix composed of proteins, sugars, and/or DNA. Bacteria in a biofilm are protected from environmental stresses, including antibiotics, which provides the bacteria with selective advantage for survival. Although some gene products are known to play roles in this developmental process inA. baumannii, mechanisms and signaling remain mostly unknown. Here, we find that Lon protease inA. baumanniiaffects biofilm development and has other important physiological roles, including motility and the cell envelope. Lon proteases are found in all domains of life, participating in regulatory processes and maintaining cellular homeostasis. These data reveal the importance of Lon protease in influencing keyA. baumanniiprocesses to survive stress and to maintain viability.IMPORTANCEAcinetobacter baumanniiis an opportunistic pathogen and is a leading cause of hospital-acquired infections.A. baumanniiis difficult to eradicate and to manage, because this bacterium is known to robustly survive desiccation and to quickly gain antibiotic resistance. We sought to investigate biofilm formation inA. baumannii, since much remains unknown about biofilm formation in this bacterium. Biofilms, which are multicellular communities of bacteria, are surface attached and difficult to eliminate from hospital equipment and implanted devices. Our research identifies multifaceted physiological roles for the conserved bacterial protease Lon inA. baumannii. These roles include biofilm formation, motility, and viability. This work broadly affects and expands understanding of the biology ofA. baumannii, which will permit us to find effective ways to eliminate the bacterium.

scholarly journals Correlation of biofilm formation and antibiotic resistance among clinical and soil isolates of Acinetobacter baumannii in Iraq

2019 ◽  
pp. 1-10 ◽  
Author(s):  
Pakhshan A. Hassan ◽  
Adel K. Khider
Keyword(s):  
Acinetobacter Baumannii ◽  
Congo Red ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Microtiter Plate ◽  
Test Tube ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Disk Diffusion Method

Acinetobacter baumannii is an opportunistic pathogen that is reported as a major cause of nosocomial infections. The aim of this study was to investigate the biofilm formation by A. baumannii clinical and soil isolates, to display their susceptibility to 11 antibiotics and to study a possible relationship between formation of biofilm and multidrug resistance. During 8 months period, from June 2016 to January 2017, a total of 52 clinical and 22 soil isolates of A. baumannii were collected and identified through conventional phenotypic, chromo agar, biochemical tests, API 20E system, and confirmed genotypically by PCR for blaOXA-51-like gene. Antibiotic susceptibility of isolates was determined by standard disk diffusion method according to Clinical and Laboratory Standard Institute. The biofilm formation was studied using Congo red agar, test tube, and microtiter plate methods. The clinical isolates were 100% resistance to ciprofloxacin, ceftazidime, piperacillin, 96.15% to gentamicin, 96.15% to imipenem, 92.31% to meropenem, and 78.85% to amikacin. The soil A. baumannii isolates were 100% sensitive to imipenem, meropenem, and gentamicin, and 90.1% to ciprofloxacin. All A. baumannii isolates (clinical and soil) were susceptible to polymyxin B. The percentage of biofilm formation in Congo red agar, test tube, and microtiter plate assays was 10.81%, 63.51%, and 86.48%, respectively. More robust biofilm former population was mainly among non-MDR isolates. Isolates with a higher level of resistance tended to form weaker biofilms. The soil isolates exhibited less resistance to antibiotics than clinical isolates. However, the soil isolates produce stronger biofilms than clinical isolates.

scholarly journals Identification and Functional Analysis of Temperate Siphoviridae Bacteriophages of Acinetobacter baumannii

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 604 ◽  
Author(s):  
Shimaa Badawy ◽  
Maria I. Pajunen ◽  
Johanna Haiko ◽  
Zakaria A. M. Baka ◽  
Mohamed I. Abou-Dobara ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Trna Gene ◽  
Phage Therapy ◽  
Morphological Characteristics ◽  
Opportunistic Pathogen ◽  
Clinical Strains ◽  
Narrow Host Range ◽  
Clinical Challenge ◽  
Transmission Electron ◽  
The Family

Acinetobacter baumannii is an opportunistic pathogen that presents a serious clinical challenge due to its increasing resistance to all available antibiotics. Phage therapy has been introduced recently to treat antibiotic-incurable A. baumannii infections. In search for new A. baumannii specific bacteriophages, 20 clinical A. baumannii strains were used in two pools in an attempt to enrich phages from sewage. The enrichment resulted in induction of resident prophage(s) and three temperate bacteriophages, named vB_AbaS_fEg-Aba01, vB_AbaS_fLi-Aba02 and vB_AbaS_fLi-Aba03, all able to infect only one strain (#6597) of the 20 clinical strains, were isolated. Morphological characteristics obtained by transmission electron microscopy together with the genomic information revealed that the phages belong to the family Siphoviridae. The ca. 35 kb genomic sequences of the phages were >99% identical to each other. The linear ds DNA genomes of the phages contained 10 nt cohesive end termini, 52–54 predicted genes, an attP site and one tRNA gene each. A database search revealed an >99% identical prophage in the genome of A. baumannii strain AbPK1 (acc. no. CP024576.1). Over 99% identical prophages were also identified from two of the original 20 clinical strains (#5707 and #5920) and both were shown to be spontaneously inducible, thus very likely being the origins of the isolated phages. The phage vB_AbaS_fEg-Aba01 was also able to lysogenize the susceptible strain #6597 demonstrating that it was fully functional. The phages showed a very narrow host range infecting only two A. baumannii strains. In conclusion, we have isolated and characterized three novel temperate Siphoviridae phages that infect A. baumannii.

scholarly journals Biofilm Formation and Detection of Fluoroquinolone- and Carbapenem-Resistant Genes in Multidrug-Resistant Acinetobacter baumannii

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
María-Guadalupe Avila-Novoa ◽  
Oscar-Alberto Solís-Velázquez ◽  
Daniel-Eduardo Rangel-López ◽  
Jean-Pierre González-Gómez ◽  
Pedro-Javier Guerrero-Medina ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Low Grade ◽  
Carbapenem Resistant ◽  
Hospital Environments ◽  
Potential Association ◽  
Clinical Environments

Acinetobacter baumannii is an important opportunistic pathogen that shows resistance to cephalosporins, penicillins, carbapenems, fluoroquinolones, and aminoglycosides, the multiresistance being associated with its ability to form biofilms in clinical environments. The aim of this study was to determine biofilm formation and its potential association with genes involved in antibiotic resistance mechanisms of A. baumannii isolates of different clinical specimens. We demonstrated 100% of the A. baumannii isolates examined to be multidrug resistant (MDR), presenting a 73.3% susceptibility to cefepime and a 53.3% susceptibility to ciprofloxacin. All A. baumannii isolates were positive for blaOXA-51, 33.3% being positive for blaOXA-23 and ISAba1, and 73.3% being positive for gyrA. We found 86.6% of A. baumannii strains to be low-grade biofilm formers and 13.3% to be biofilm negative; culturing on Congo red agar (CRA) plates revealed that 73.3% of the A. baumannii isolates to be biofilm producers, while 26.6% were not. These properties, combined with the role of A. baumannii as a nosocomial pathogen, increase the probability of A. baumannii causing nosocomial infections and outbreaks as a complication during therapeutic treatments and emphasize the need to control A. baumannii biofilms in hospital environments.

Multidrug Resistance Related to Biofilm Formation in Acinetobacter baumannii and Klebsiella pneumoniae Clinical Strains from Different Pulsotypes

2016 ◽  
Vol 72 (5) ◽  
pp. 617-627 ◽  
Author(s):  
Paola Amaral de Campos ◽  
Sabrina Royer ◽  
Deivid William da Fonseca Batistão ◽  
Bruna Fuga Araújo ◽  
Lícia Ludendorff Queiroz ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Clinical Strains

scholarly journals RecA levels modulate biofilm development in Acinetobacter baumannii

2019 ◽  
Author(s):  
Carly Ching ◽  
Paul Muller ◽  
Merlin Brychcy ◽  
Alicyn Reverdy ◽  
Brian Nguyen ◽  
...  
Keyword(s):  
Dna Damage ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Opportunistic Pathogen ◽  
Cell Types ◽  
Surface Attachment ◽  
Damage Response ◽  
Fundamental Biology ◽  
Biofilm Development

AbstractInfections caused by Acinetobacter baumannii, a Gram-negative opportunistic pathogen, are difficult to eradicate due to the bacterium’s propensity to quickly gain antibiotic resistances and form protective bacterial multicellular communities known as biofilms. The A. baumannii DNA damage response (DDR) mediates antibiotic resistance acquisition and regulates RecA in an atypical fashion; both RecALow and RecAHigh cell types are formed in response to DNA damage. In this study, we show that RecA levels modulate biofilm development, formation and dispersal, through bfmR, the global biofilm regulator. RecA loss results in surface attachment and prominent biofilms while elevated RecA leads to diminished attachment and dispersal. Recalcitrance to treatment may be explained by DDR induction, common during infection, and the balance between biofilm maintenance in low RecA cells, and increased mutagenesis and dispersal to reach new niches in high RecA cells. These data highlight the importance of understanding fundamental biology to better treat bacterial infections.ImpactThe mechanism of biofilm formation and dispersal in A. baumannii, shown here to depend on RecA levels, contributes to the understanding of recalcitrant infections caused by this important pathogen.

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