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 Biofilm-Induced Antibiotic Resistance in Clinical Acinetobacter baumannii Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 817
Author(s):  
Abebe Mekuria Shenkutie ◽  
Mian Zhi Yao ◽  
Gilman Kit-hang Siu ◽  
Barry Kin Chung Wong ◽  
Polly Hang-mei Leung
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Antibiotic Tolerance ◽  
Planktonic Cells ◽  
Antibiotic Susceptibilities ◽  
Extensively Drug Resistant

In order to understand the role of biofilm in the emergence of antibiotic resistance, a total of 104 clinical Acinetobacter baumannii strains were investigated for their biofilm-forming capacities and genes associated with biofilm formation. Selected biofilm-formers were tested for antibiotic susceptibilities when grown in biofilm phase. Reversibility of antibiotic susceptibility in planktonic cells regrown from biofilm were investigated. We found 59.6% of the strains were biofilm-formers, among which, 66.1% were non-multidrug resistant (MDR) strains. Presence of virulence genes bap, csuE, and abaI was significantly associated with biofilm-forming capacities. When strains were grown in biofilm state, the minimum biofilm eradication concentrations were 44, 407, and 364 times higher than the minimum bactericidal concentrations (MBC) for colistin, ciprofloxacin, and imipenem, respectively. Persisters were detected after treating the biofilm at 32–256 times the MBC of planktonic cells. Reversibility test for antibiotic susceptibility showed that biofilm formation induced reversible antibiotic tolerance in the non-MDR strains but a higher level of irreversible resistance in the extensively drug-resistant (XDR) strain. In summary, we showed that the non-MDR strains were strong biofilm-formers. Presence of persisters in biofilm contributed to the reduced antibiotic susceptibilities. Biofilm-grown Acinetobacter baumannii has induced antibiotic tolerance in non-MDR strains and increased resistance levels in XDR strains. To address the regulatory mechanisms of biofilm-specific resistance, thorough investigations at genome and transcription levels are warranted.

scholarly journals Disruption of Biofilm Formation by the Human Pathogen Acinetobacter baumannii Using Engineered Quorum-Quenching Lactonases

2013 ◽  
Vol 58 (3) ◽  
pp. 1802-1805 ◽  
Author(s):  
Jeng Yeong Chow ◽  
Yuanyong Yang ◽  
Song Buck Tay ◽  
Kim Lee Chua ◽  
Wen Shan Yew
Keyword(s):  
Quorum Sensing ◽  
Acinetobacter Baumannii ◽  
Directed Evolution ◽  
Nosocomial Infections ◽  
Biofilm Formation ◽  
Quorum Quenching ◽  
Multidrug Resistant ◽  
Human Pathogen ◽  
Content Type ◽  
Biofilm Disruption

ABSTRACTAcinetobacter baumanniiis a major human pathogen associated with multidrug-resistant nosocomial infections; its virulence is attributed to quorum-sensing-mediated biofilm formation, and disruption of biofilm formation is an attractive antivirulence strategy. Here, we report the first successful demonstration of biofilm disruption in a clinical isolate ofA. baumanniiS1, using a quorum-quenching lactonase obtained by directed evolution; this engineered lactonase significantly reduced the biomass ofA. baumannii-associated biofilms, demonstrating the utility of this antivirulence strategy.

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.

scholarly journals Decreased expression of femXAB genes and fnbp mediated biofilm pathways in OS-MRSA clinical isolates

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Umarani Brahma ◽  
Paresh Sharma ◽  
Shweta Murthy ◽  
Savitri Sharma ◽  
Shalini Chakraborty ◽  
...  
Keyword(s):  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Agglutination Test ◽  
Clinical Isolates ◽  
Ocular Infections ◽  
Biofilm Production ◽  
Fibronectin Binding ◽  
Sequence Types

Abstract Methicillin-Resistant Staphylococcus aureus (MRSA) is a significant threat to human health. Additionally, biofilm forming bacteria becomes more tolerant to antibiotics and act as bacterial reservoir leading to chronic infection. In this study, we characterised the antibiotic susceptibility, biofilm production and sequence types (ST) of 74 randomly selected clinical isolates of S. aureus causing ocular infections. Antibiotic susceptibility revealed 74% of the isolates as resistant against one or two antibiotics, followed by 16% multidrug-resistant isolates (MDR), and 10% sensitive. The isolates were characterized as MRSA (n = 15), Methicillin-sensitive S. aureus (MSSA, n = 48) and oxacillin susceptible mecA positive S. aureus (OS-MRSA, n = 11) based on oxacillin susceptibility, mecA gene PCR and PBP2a agglutination test. All OS-MRSA would have been misclassified as MSSA on the basis of susceptibility test. Therefore, both phenotypic and genotypic tests should be included to prevent strain misrepresentation. In addition, in-depth studies for understanding the emerging OS-MRSA phenotype is required. The role of fem XAB gene family has been earlier reported in OS-MRSA phenotype. Sequence analysis of the fem XAB genes revealed mutations in fem × (K3R, H11N, N18H and I51V) and fem B (L410F) genes. The fem XAB genes were also found down-regulated in OS-MRSA isolates in comparison to MRSA. In OS-MRSA isolates, biofilm formation is regulated by fibronectin binding proteins A & B. Molecular typing of the isolates revealed genetic diversity. All the isolates produced biofilm, however, MRSA isolates with strong biofilm phenotype represent a worrisome situation and may even result in treatment failure.

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 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 Molecular Analysis of the Acinetobacter baumannii Biofilm-Associated Protein

2013 ◽  
Vol 79 (21) ◽  
pp. 6535-6543 ◽  
Author(s):  
H. M. Sharon Goh ◽  
Scott A. Beatson ◽  
Makrina Totsika ◽  
Danilo G. Moriel ◽  
Minh-Duy Phan ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Hospital Environment ◽  
Biofilm Growth ◽  
Content Type ◽  
Amino Acid Region ◽  
Carbapenem Resistant ◽  
C Terminus ◽  
And Function

ABSTRACTAcinetobacter baumanniiis a multidrug-resistant pathogen associated with hospital outbreaks of infection across the globe, particularly in the intensive care unit. The ability ofA. baumanniito survive in the hospital environment for long periods is linked to antibiotic resistance and its capacity to form biofilms. Here we studied the prevalence, expression, and function of theA. baumanniibiofilm-associated protein (Bap) in 24 carbapenem-resistantA. baumanniiST92 strains isolated from a single institution over a 10-year period. Thebapgene was highly prevalent, with 22/24 strains being positive forbapby PCR. Partial sequencing ofbapwas performed on the index case strain MS1968 and revealed it to be a large and highly repetitive gene approximately 16 kb in size. Phylogenetic analysis employing a 1,948-amino-acid region corresponding to the C terminus of Bap showed that BapMS1968clusters with Bap sequences from clonal complex 2 (CC2) strains ACICU, TCDC-AB0715, and 1656-2 and is distinct from Bap in CC1 strains. By using overlapping PCR, thebapMS1968gene was cloned, and its expression in a recombinantEscherichia colistrain resulted in increased biofilm formation. A Bap-specific antibody was generated, and Western blot analysis showed that the majority ofA. baumanniistrains expressed an ∼200-kDa Bap protein. Further analysis of three Bap-positiveA. baumanniistrains demonstrated that Bap is expressed at the cell surface and is associated with biofilm formation. Finally, biofilm formation by these Bap-positive strains could be inhibited by affinity-purified Bap antibodies, demonstrating the direct contribution of Bap to biofilm growth byA. baumanniiclinical isolates.

Sign in / Sign up

Export Citation Format

Share Document