Biocide-tolerant multidrug-resistant Acinetobacter baumannii clinical strains are associated with higher biofilm formation

2009 ◽  
Vol 73 (3) ◽  
pp. 287-289 ◽  
Author(s):  
G. Rajamohan ◽  
V.B. Srinivasan ◽  
W.A. Gebreyes
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Clinical Strains

scholarly journals Genomic analysis reveals high virulence and antibiotic resistance amongst phage susceptible Acinetobacter baumannii

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Udomluk Leungtongkam ◽  
Rapee Thummeepak ◽  
Thawatchai Kitti ◽  
Kannipa Tasanapak ◽  
Jintana Wongwigkarn ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Copper Tolerance ◽  
Virulence Determinants ◽  
Genome Sequences ◽  
High Virulence

Abstract In this study, we examined the association between antimicrobial resistance, CRISPR/Cas systems and virulence with phage susceptibility in Acinetobacter baumannii and investigated draft genomes of phage susceptible multidrug resistant A. baumannii strains from Thailand. We investigated 230 A. baumannii strains using 17 lytic A. baumannii phages and the phage susceptibility was 46.5% (107/230). Phage susceptibility was also associated with resistance to numerous antibiotics (p-value < 0.05). We also found association between biofilm formation and the presence of ompA gene among phage susceptible A. baumannii strains (p-value < 0.05). A. baumannii isolates carrying cas5 or combinations of two or three other cas genes, showed a significant increase in phage resistance. Whole-genome sequences of seven phage susceptible A. baumannii isolates revealed that six groups of antibiotic resistance genes were carried by all seven phage susceptible A. baumannii. All strains carried biofilm associated genes and two strains harbored complete prophages, acquired copper tolerance genes, and CRISPR-associated (cas) genes. In conclusion, our data exhibits an association between virulence determinants and biofilm formation among phage susceptible A. baumannii strains. These data help to understand the bacterial co-evolution with phages.

Aluminium oxide nanoparticles inhibit EPS production, adhesion and biofilm formation by multidrug resistant Acinetobacter baumannii

Biofouling ◽  
2020 ◽  
Vol 36 (4) ◽  
pp. 492-504 ◽  
Author(s):  
Saima Muzammil ◽  
Mohsin Khurshid ◽  
Iqra Nawaz ◽  
Muhammad Hussnain Siddique ◽  
Muhammad Zubair ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Aluminium Oxide ◽  
Multidrug Resistant ◽  
Oxide Nanoparticles ◽  
Aluminium Oxide Nanoparticles

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.

scholarly journals Draft Genome Sequences of Two Carbapenemase-Producing Acinetobacter baumannii Clinical Strains Isolated from Albanian and Togolese Patients

2017 ◽  
Vol 5 (20) ◽  
Author(s):  
Mohamed M. H. Abdelbary ◽  
Guy Prod’hom ◽  
Gilbert Greub ◽  
Laurence Senn ◽  
Dominique S. Blanc
Keyword(s):  
Acinetobacter Baumannii ◽  
Draft Genome ◽  
Multidrug Resistant ◽  
University Hospital ◽  
Genome Sequences ◽  
Content Type ◽  
Clinical Strains

ABSTRACT We report here the draft genome sequences of two multidrug-resistant Acinetobacter baumannii clinical strains, H31499 and H31506, which were isolated at the Lausanne University Hospital in 2015 from an Albanian and a Togolese patient, respectively.

scholarly journals Aerosolized Hypertonic Saline Hinders Biofilm Formation to Enhance Antibiotic Susceptibility of Multidrug-Resistant Acinetobacter baumannii

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1115
Author(s):  
Hui-Ling Lin ◽  
Chen-En Chiang ◽  
Mei-Chun Lin ◽  
Mei-Lan Kau ◽  
Yun-Tzu Lin ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Acinetobacter Baumannii ◽  
Hypertonic Saline ◽  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
Therapeutic Strategy ◽  
Extracellular Polymeric Substances ◽  
Multidrug Resistant ◽  
Biofilm Disruption

Limited therapeutic options are available for multidrug-resistant Acinetobacter baumannii (MDR-AB), and the development of effective treatments is urgently needed. The efficacy of four aerosolized antibiotics (gentamicin, amikacin, imipenem, and meropenem) on three different MDR-AB strains was evaluated using hypertonic saline (HS, 7 g/100 mL) as the aerosol carrier. HS aerosol effectively hindered biofilm formation by specific MDR-AB strains. It could also interrupt the swarming dynamics of MDR-AB and the production of extracellular polymeric substances, which are essential for biofilm progression. Biofilms protect the microorganisms from antibiotics. The use of HS aerosol as a carrier resulted in a decreased tolerance to gentamicin and amikacin in the biofilm-rich MDR-AB. Moreover, we tested the aerosol characteristics of antibiotics mixed with HS and saline, and results showed that HS enhanced the inhaled delivery dose with a smaller particle size distribution of the four antibiotics. Our findings demonstrate the potential of using “old” antibiotics with our “new” aerosol carrier, and potentiate an alternative therapeutic strategy to eliminate MDR-AB infections from a biofilm-disruption perspective.

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 Biofilm-Formation in Clonally Unrelated Multidrug-Resistant Acinetobacter baumannii Isolates

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 630 ◽  
Author(s):  
Aisha M. Alamri ◽  
Afnan A. Alsultan ◽  
Mohammad A. Ansari ◽  
Amani M. Alnimr
Keyword(s):  
Tissue Culture ◽  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Congo Red ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Control Measures ◽  
Infection Control Measures ◽  
Culture Plate ◽  
Tissue Culture Plate

This study analyzed the genotype, antibiotic resistance, and biofilm formation of Acinetobacter baumannii strains and assessed the correlation between biofilm formation, antibiotic resistance, and biofilm-related risk factors. A total of 207 non-replicate multi-drug-resistant A. baumannii strains were prospectively isolated. Phenotypic identification and antimicrobial susceptibility testing were carried out. Isolate biofilm formation ability was evaluated using the tissue culture plate (TCP), Congo red agar, and tube methods. Clonal relatedness between the strains was assessed by enterobacterial repetitive intergenic consensus-PCR genotyping. Of the 207 isolates, 52.5% originated from an intensive care unit setting, and pan resistance was observed against ceftazidime and cefepime, with elevated resistance (99–94%) to piperacillin/tazobactam, imipenem, levofloxacin, and ciprofloxacin. alongside high susceptibility to tigecycline (97.8%). The Tissue culture plate, Tube method, and Congo red agar methods revealed that 53.6%, 20.8%, and 2.7% of the strains were strong biofilm producers, respectively, while a significant correlation was observed between biofilm formation and device-originating respiratory isolates (p = 0.0009) and between biofilm formation in colonized vs. true infection isolates (p = 0.0001). No correlation was detected between antibiotic resistance and biofilm formation capacity, and the majority of isolates were clonally unrelated. These findings highlight the urgent need for implementing strict infection control measures in clinical settings.

scholarly journals COMBINATORIAL EFFECT OF D-AMINOACIDS AND TETRACYCLINE AGAINST PSEUDOMONAS AERUGINOSA BIOFILM

2016 ◽  
Vol 8 (11) ◽  
pp. 216
Author(s):  
H. Jayalekshmi ◽  
C. Harikrishnan ◽  
Sajin Sali ◽  
N. Kaushik ◽  
Norin Mary G. Victus ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Wound Dressing ◽  
Ex Vivo ◽  
Multidrug Resistant ◽  
Antibiofilm Activity ◽  
Porcine Skin ◽  
Clinical Strains ◽  
Microtitre Plate Assay

Objective: The present study attempted to evaluate the anti-biofilm activity of D-amino acids (D-AAs) on Pseudomonas aeruginosa and determine if the combination of D-AAs with tetracycline enhances the anti-biofilm activity in vitro and ex vivo.Methods: Different D-AAs were tested for antibiofilm activity against wild type P. aeruginosa PAO1 and two multidrug resistant P. aeruginosa clinical strains in the presence of sub inhibitory concentrations of tetracycline using crystal violet microtitre plate assay. Results were further validated using in vitro wound dressing and ex vivo porcine skin models followed by cytotoxicity and hemocompatibility studies.Results: D-tryptophan (5 mmol) showed 61 % reduction in biofilm formation of P. aeruginosa. Interestingly combinatorial effect of 5 mmol D-tryptophan and 0.5 minimum inhibitory concentration (MIC) (7.5µg/ml) tetracycline showed 90% reduction in biofilm formation. 5 mmol D-methionine shows 28 % reduction and combination with tetracycline shows 41% reduction in biofilm formation of P. aeruginosa. D-leucine and D-tyrosine alone or in combination with tetracycline did not show significant anti-biofilm activity. D tryptophan-tetracycline combination could reduce 80 % and 77 % reduction in biofilm formation in two multi drug resistant P. aeruginosa clinical strains. D-tryptophan-tetracycline-combination could also reduce 76% and 66% reduction in biofilm formation in wound dressing model and porcine skin explant respectively. The cytotoxicity and hemocompatibility studies did not show significant toxicity when this combination was used.Conclusion: The results established the potential therapeutic application of D-tryptophan alone or in combination with tetracycline for treating biofilm associated clinical problems caused by P. aeruginosa.

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