Molecular typing, biofilm production, and detection of carbapenemase genes in multidrug-resistant Acinetobacter baumannii isolated from different infection sites using ERIC-PCR in Hamadan, west of Iran

Abstract Background Acinetobacter baumannii is an opportunistic pathogen that can cause several kinds of nosocomial infections. Increasing antibiotic resistance as well as identifying genetic diversity and factors associated with pathogenicity and prevalence of this bacterium is important. The aim of this study was the investigation of molecular typing, biofilm production, and detection of carbapenemase genes in multidrug-resistant Acinetobacter baumannii isolated from different infection sites using ERIC-PCR in Iran. Methods Forty isolates of A. baumannii were obtained from various wards of the central hospital, in the west of Iran. Phenotypic identification and genetic diversity, biofilm production assay, and detection of Carbapenemase genes carried out. Results Tracheal samples 26 (61.9 %) are the most frequent isolates, and 95 % of isolates were identified as MDR. 32.5 % of all A. baumannii strains were capable to form a strong biofilm. It was founded that antimicrobial resistance patterns had a significant relationship with strong biofilm formation (P = 0.001). Most frequencies of the studied genes were in the order of VIM (81 %), SPM (45.2 %), and IMP (35.7 %) genes. The VIM gene was the most frequent in all isolates which were significant (P = 0.006). 14 different ERIC-types were observed including 7 common types and 7 unique or single types. F type is the largest common type consisting of nine isolates and B, D, and E types contain two isolates separately. Conclusions ERIC-PCR technique was used to genetically classify A. baumannii isolates as one of the most common microorganisms in nosocomial infections.

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

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2019/3454907 ◽

2019 ◽

Vol 2019 ◽

pp. 1-5 ◽

Cited By ~ 7

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.

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Biofilm Measurement, Site Specific Variation in Biofilm Production, Biofilm Typing: An Acinetobacter Trilogy

European Journal of Medical and Health Sciences ◽

10.24018/ejmed.2019.1.4.74 ◽

2019 ◽

Vol 1 (4) ◽

Author(s):

Baishali Chakraborty ◽

Dibyendu Banerjee ◽

Shubhankar Mukherjee

Keyword(s):

Acinetobacter Baumannii ◽

Biofilm Formation ◽

Multidrug Resistant ◽

Hospital Environment ◽

Plate Method ◽

System A ◽

Biofilm Production ◽

Feasible Alternative ◽

Specific Variation ◽

Eskape Pathogens

Acinetobacter baumannii is a member of the ESKAPE pathogens, notorious for causing multidrug resistant nosocomial infections worldwide. Biofilm has an important role in its persistence and spread in hospital environment, as well as its multidrug resistance potential. The present study was aimed at finding out whether the strength of Biofilm formation varies with infection of different organs / system. A total of 136 isolates of Acinetobacter baumannii were taken from a variety of samples. Strength of Biofilm formation, determined by Tissue culture plate method, was graded according to OD value in ELISA reader as nil, moderate and strong. It was seen that association between variations in biofilm forming capacity depending on different sites of infection was statistically significant. We suggest biofilm typing by this method for this pathogen, as a potentially feasible alternative in countries with cost restrained healthcare set ups. Moreover, biofilm typing report would be more meaningful to the clinicians as well.

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02410-13 ◽

2013 ◽

Vol 58 (3) ◽

pp. 1802-1805 ◽

Cited By ~ 40

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.

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TheAcinetobacter baumanniiTwo-Component System AdeRS Regulates Genes Required for Multidrug Efflux, Biofilm Formation, and Virulence in a Strain-Specific Manner

mBio ◽

10.1128/mbio.00430-16 ◽

2016 ◽

Vol 7 (2) ◽

Cited By ~ 47

Author(s):

Grace E. Richmond ◽

Laura P. Evans ◽

Michele J. Anderson ◽

Matthew E. Wand ◽

Laura C. Bonney ◽

...

Keyword(s):

Multidrug Resistance ◽

Acinetobacter Baumannii ◽

Biofilm Formation ◽

Galleria Mellonella ◽

Efflux Pump ◽

Ex Vivo ◽

Natural Infection ◽

Opportunistic Pathogen ◽

Multidrug Resistant ◽

Component System

ABSTRACTThe opportunistic pathogenAcinetobacter baumanniiis able to persist in the environment and is often multidrug resistant (MDR), causing difficulties in the treatment of infections. Here, we show that the two-component system AdeRS, which regulates the production of the AdeABC multidrug resistance efflux pump, is required for the formation of a protective biofilm in anex vivoporcine mucosal model, which mimics a natural infection of the human epithelium. Interestingly, deletion ofadeBimpacted only on the ability of strain AYE to form a biofilm on plastic and only on the virulence of strain Singapore 1 forGalleria mellonella. RNA-Seq revealed that loss of AdeRS or AdeB significantly altered the transcriptional landscape, resulting in the changed expression of many genes, notably those associated with antimicrobial resistance and virulence interactions. For example,A. baumanniilacking AdeRS displayed decreased expression ofadeABC,pilgenes,comgenes, and apgaC-like gene, whereas loss of AdeB resulted in increased expression ofpilandcomgenes and decreased expression of ferric acinetobactin transport system genes. These data define the scope of AdeRS-mediated regulation, show that changes in the production of AdeABC mediate important phenotypes controlled by AdeRS, and suggest that AdeABC is a viable target for antimicrobial drug and antibiofilm discovery.IMPORTANCEAcinetobacter baumanniiis a nosocomial pathogen and is an increasing problem in hospitals worldwide. This organism is often multidrug resistant, can persist in the environment, and forms a biofilm on environmental surfaces and wounds. Overproduction of efflux pumps can allow specific toxic compounds to be pumped out of the cell and can lead to multidrug resistance. This study demonstrates the role of theA. baumanniiefflux pump AdeB, and its regulator AdeRS, in multidrug resistance, epithelial cell killing, and biofilm formation. Deletion of the genes encoding these systems led to increased susceptibility to antibiotics, decreased biofilm formation on biotic and abiotic surfaces, and decreased virulence. Our data suggest that inhibition of AdeB could prevent biofilm formation or colonization in patients byA. baumanniiand provides a good target for drug discovery.

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Epidemiology and Genetic Diversity of Colistin Nonsusceptible Nosocomial Acinetobacter baumannii Strains from Russia for 2013-2014

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2017/1839190 ◽

2017 ◽

Vol 2017 ◽

pp. 1-5 ◽

Cited By ~ 12

Author(s):

Eugene A. Sheck ◽

Mikhail V. Edelstein ◽

Marina V. Sukhorukova ◽

Natali V. Ivanchik ◽

Elena Yu. Skleenova ◽

...

Keyword(s):

Genetic Diversity ◽

Antibiotic Resistance ◽

Acinetobacter Baumannii ◽

Nosocomial Infections ◽

Multidrug Resistant ◽

Drug Resistant ◽

Extensively Drug Resistant ◽

Epidemiological Features ◽

High Level ◽

Therapeutic Possibilities

A high level of resistance to carbapenems in Acinetobacter baumannii strains severely limits therapeutic possibilities. Colistin is the last resort drug against such strains, although the cases of resistance to this drug have become more frequent. This article presents the epidemiological features and genetic diversity of colistin nonsusceptible A. baumannii strains collected as part of a national multicenter epidemiological study of the antibiotic resistance of pathogens of nosocomial infections (MARATHON), which was conducted in 2013-2014 in Russia. A total of 527 A. baumannii isolates were collected, 10 (1.9%) of which were nonsusceptible to colistin. The majority of nonsusceptible A. baumannii isolates to colistin showed resistance to carbapenems and had the genes of the acquired OXA-40-like carbapenemases (n=6). In one case, a combination of OXA-23-like + OXA-40-like (n=1) genes was identified. One strain had the multidrug-resistant (MDR) phenotype, 6 isolates had extensively drug-resistant (XDR) phenotype, and 3 isolates had pandrug-resistant (PDR) phenotype. Among the colistin nonsusceptible A. baumannii isolates, 6 individual genotypes were identified, most of which belonged to successful international clones (CC92OXF/CC2PAS, n=4; CC944OXF/ST78PAS, n=4; CC109OXF/CC1PAS, n=1).

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Characterization of biofilm production in different strains of Acinetobacter baumannii and the effects of chemical compounds on biofilm formation

PeerJ ◽

10.7717/peerj.9020 ◽

2020 ◽

Vol 8 ◽

pp. e9020

Author(s):

Ming-Feng Lin ◽

Yun-You Lin ◽

Chung-Yu Lan

Keyword(s):

Acinetobacter Baumannii ◽

Nosocomial Infections ◽

Biofilm Formation ◽

Chemical Compounds ◽

Laser Scanning Microscopy ◽

Hospital Environment ◽

Clinical Strain ◽

Wild Type ◽

Biofilm Production ◽

Different Strains

Acinetobacter baumannii, an important emerging pathogen of nosocomial infections, is known for its ability to form biofilms. Biofilm formation increases the survival rate of A. baumannii on dry surfaces and may contribute to its persistence in the hospital environment, which increases the probability of nosocomial infections and outbreaks. This study was undertaken to characterize the biofilm production of different strains of A. baumannii and the effects of chemical compounds, especially antibiotics, on biofilm formation. In this study, no statistically significant relationship was observed between the ability to form a biofilm and the antimicrobial susceptibility of the A. baumannii clinical isolates. Biofilm formation caused by A. baumannii ATCC 17978 after gene knockout of two-component regulatory system gene baeR, efflux pump genes emrA/emrB and outer membrane coding gene ompA revealed that all mutant strains had less biofilm formation than the wild-type strain, which was further supported by the images from scanning electron microscopy and confocal laser scanning microscopy. The addition of amikacin, colistin, LL-37 or tannic acid decreased the biofilm formation ability of A. baumannii. In contrast, the addition of lower subinhibitory concentration tigecycline increased the biofilm formation ability of A. baumannii. Minimum biofilm eradication concentrations of amikacin, imipenem, colistin, and tigecycline were increased obviously for both wild type and multidrug resistant clinical strain A. baumannii VGH2. In conclusion, the biofilm formation ability of A. baumannii varied in different strains, involved many genes and could be influenced by many chemical compounds.

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Lon Protease Has Multifaceted Biological Functions inAcinetobacter baumannii

Journal of Bacteriology ◽

10.1128/jb.00536-18 ◽

2018 ◽

Vol 201 (2) ◽

Cited By ~ 5

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.

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Association among biofilm formation, virulence gene expression, and antibiotic resistance in Proteus mirabilis isolates from diarrhetic animals in northeast China

10.21203/rs.2.16502/v2 ◽

2020 ◽

Author(s):

Yadong Sun ◽

Shanshan Wen ◽

Lili Zhao ◽

Qiqi Xia ◽

Yue Pan ◽

...

Keyword(s):

Gene Expression ◽

Antibiotic Resistance ◽

Biofilm Formation ◽

Northeast China ◽

Virulence Gene ◽

Drug Susceptibility ◽

Multidrug Resistant ◽

Virulence Gene Expression ◽

Biofilm Production ◽

High Level

Abstract Background The aim of this study was to investigate the association among biofilm formation, virulence gene expression, and antibiotic resistance in P. mirabilis isolates collected from diarrhetic animals (n = 176) in northeast China between September 2014 and October 2016. Results Approximately 92.05% of the isolates were biofilm producers, whereas 7.95% of the isolates were non-producers. The prevalence of virulence genes in biofilm producers was significantly higher than that in non-producers. Biofilm production was significantly associated with the expression of ureC , zapA , rsmA , hmpA , mrpA , atfA , and pmfA ( P < 0.05). Drug susceptibility tests revealed that approximately 76.7% of the isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR). Biofilm production was significantly associated with resistance to doxycycline, tetracycline, sulfamethoxazole, kanamycin, and cephalothin ( P < 0.05). Although the pathogenicity of the biofilm producers was stronger than that of the non-producers, the biofilm-forming ability of the isolates was not significantly associated with morbidity and mortality in mice ( P > 0.05). Conclusion Our findings suggested that a high level of multidrug resistance in diarrhetic animals infected with P. mirabilis in northeast China.The results of this study indicated that the positive rates of the genes expressed by biofilm-producing P. mirabilis isolates were significantly higher than those expressed by non-producing isolates.

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Complete Genome Sequence of Lytic Bacteriophage LZ35 Infecting Acinetobacter baumannii Isolates

Genome Announcements ◽

10.1128/genomea.01104-16 ◽

2016 ◽

Vol 4 (6) ◽

Cited By ~ 2

Author(s):

Zhonghe Guo ◽

Honglan Huang ◽

Xiaolin Wu ◽

Yuchong Hao ◽

Yanbo Sun

Keyword(s):

Acinetobacter Baumannii ◽

Genome Sequence ◽

Nosocomial Infections ◽

Complete Genome Sequence ◽

Complete Genome ◽

Opportunistic Pathogen ◽

Lytic Bacteriophage ◽

Gram Negative

Acinetobacter baumannii is a Gram-negative opportunistic pathogen that is frequently associated with nosocomial infections. Bacteriophages infecting A. baumannii can be used as effective agents to control these infections. Here, we announce the complete genome sequence of the lytic bacteriophage LZ35 infecting A. baumannii isolates.

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

Acta Microbiologica et Immunologica Hungarica ◽

10.1556/030.66.2019.026 ◽

2019 ◽

pp. 1-10 ◽

Cited By ~ 1

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.

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