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Lysitsas M, Triantafillou E, Chatzipanagiotidou I, Antoniou K, Spyrou V, Billinis C, Valiakos G. Phenotypic Investigation and Detection of Biofilm-Associated Genes in Acinetobacter baumannii Isolates, Obtained from Companion Animals. Trop Med Infect Dis 2024; 9:109. [PMID: 38787042 PMCID: PMC11125616 DOI: 10.3390/tropicalmed9050109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/01/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024] Open
Abstract
Bacteria of the genus Acinetobacter, especially Acinetobacter baumannii (Ab), have emerged as pathogens of companion animals during the last two decades and are commonly associated with hospitalization and multidrug resistance. A critical factor for the distribution of relevant strains in healthcare facilities, including veterinary facilities, is their adherence to both biotic and abiotic surfaces and the production of biofilms. A group of 41 A. baumannii isolates obtained from canine and feline clinical samples in Greece was subjected to phenotypic investigation of their ability to produce biofilms using the tissue culture plate (TCP) method. All of them (100%) produced biofilms, while 23 isolates (56.1%) were classified as strong producers, 11 (26.8%) as moderate producers, and 7 (17.1%) as weak producers. A correlation between the MDR and XDR phenotypes and weak or moderate biofilm production was identified. Moreover, the presence of four biofilm-associated genes bap, blaPER, ompA, and csuE was examined by PCR, and they were detected in 100%, 65.9%, 97.6%, and 95.1% of the strains respectively. All isolates carried at least two of the investigated genes, whereas most of the strong biofilm producers carried all four genes. In conclusion, the spread and persistence of biofilm-producing Ab strains in veterinary facilities is a matter of concern, since they are regularly obtained from infected animals, indicating their potential as challenging pathogens for veterinarians due to multidrug resistance and tolerance in conventional eradication measures. Furthermore, considering that companion animals can act as reservoirs of relevant strains, public health concerns emerge.
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Affiliation(s)
- Marios Lysitsas
- Faculty of Veterinary Science, University of Thessaly, 43100 Karditsa, Greece; (M.L.); (C.B.)
| | | | | | - Konstantina Antoniou
- Vet Analyseis, Private Diagnostic Laboratory, 41335 Larissa, Greece; (E.T.); (K.A.)
| | - Vassiliki Spyrou
- Department of Animal Science, University of Thessaly, 41334 Larissa, Greece;
| | - Charalambos Billinis
- Faculty of Veterinary Science, University of Thessaly, 43100 Karditsa, Greece; (M.L.); (C.B.)
| | - George Valiakos
- Faculty of Veterinary Science, University of Thessaly, 43100 Karditsa, Greece; (M.L.); (C.B.)
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2
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Ding Y, Hao J, Xiao W, Ye C, Xiao X, Jian C, Tang M, Li G, Liu J, Zeng Z. Role of efflux pumps, their inhibitors, and regulators in colistin resistance. Front Microbiol 2023; 14:1207441. [PMID: 37601369 PMCID: PMC10436536 DOI: 10.3389/fmicb.2023.1207441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/13/2023] [Indexed: 08/22/2023] Open
Abstract
Colistin is highly promising against multidrug-resistant and extensively drug-resistant bacteria clinically. Bacteria are resistant to colistin mainly through mcr and chromosome-mediated lipopolysaccharide (LPS) synthesis-related locus variation. However, the current understanding cannot fully explain the resistance mechanism in mcr-negative colistin-resistant strains. Significantly, the contribution of efflux pumps to colistin resistance remains to be clarified. This review aims to discuss the contribution of efflux pumps and their related transcriptional regulators to colistin resistance in various bacteria and the reversal effect of efflux pump inhibitors on colistin resistance. Previous studies suggested a complex regulatory relationship between the efflux pumps and their transcriptional regulators and LPS synthesis, transport, and modification. Carbonyl cyanide 3-chlorophenylhydrazone (CCCP), 1-(1-naphthylmethyl)-piperazine (NMP), and Phe-Arg-β-naphthylamide (PAβN) all achieved the reversal of colistin resistance, highlighting the role of efflux pumps in colistin resistance and their potential for adjuvant development. The contribution of the efflux pumps to colistin resistance might also be related to specific genetic backgrounds. They can participate in colistin tolerance and heterogeneous resistance to affect the treatment efficacy of colistin. These findings help understand the development of resistance in mcr-negative colistin-resistant strains.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Jinbo Liu
- Department of Laboratory Medicine, the Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Zhangrui Zeng
- Department of Laboratory Medicine, the Affiliated Hospital of Southwest Medical University, Luzhou, China
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3
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Denysko TV, Nazarchuk OA, Gruzevskyi O, Bahniuk NÀ, Dmytriiev DV, Chornopyschuk RM, Bebyk VV. In vitro evaluation of the antimicrobial activity of antiseptics against clinical Acinetobacter baumannii strains isolated from combat wounds. Front Microbiol 2022; 13:932467. [PMID: 36267170 PMCID: PMC9577188 DOI: 10.3389/fmicb.2022.932467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
Healthcare-associated infections (HCAIs) are among the most prominent medical problems worldwide. In the context of increasing antibiotic resistance globally, the use of antiseptics as the main active agent and potentiator of antibiotics for the treatment of purulent-inflammatory complications of traumatic wounds, burns, and surgical wounds can be considered to tackle opportunistic infections and their prevention during war. This study presents a comparative investigation of the antimicrobial efficacy of antiseptics used for surgical antisepsis and antiseptic treatment of skin, mucous membranes, and wounds against multidrug-resistant clinical isolates of Acinetobacter baumannii as a wound pathogen of critical priority (according to the WHO). It was found that strains of A. baumannii, which have natural and acquired resistance to antimicrobial drugs, remain susceptible to modern antiseptics. Antiseptic drugs based on decamethoxine, chlorhexidine, octenidine, polyhexanide, and povidone-iodine 10% and 2% provide effective bactericidal activity against A. baumannii within the working concentrations of these drugs. Chlorhexidine and decamethoxine can inhibit biofilm formation by A. baumannii cells. In terms of bactericidal properties and biofilm formation inhibition, chlorhexidine and decamethoxine are the most effective of all tested antiseptics.
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Affiliation(s)
- Tetyana Valeriyivna Denysko
- Department of Microbiology, Virology and Immunology, National Pirogov Memorial Medical University, Vinnytsya, Ukraine
| | - Oleksandr Adamovych Nazarchuk
- Department of Microbiology, Virology and Immunology, National Pirogov Memorial Medical University, Vinnytsya, Ukraine
- *Correspondence: Oleksandr Adamovych Nazarchuk,
| | - Oleksandr Gruzevskyi
- Department of Microbiology, Virology and Immunology Odessa National Medical University, Odessa, Ukraine
| | - Nataliia Ànatoliivna Bahniuk
- Department of Microbiology, Virology and Immunology, National Pirogov Memorial Medical University, Vinnytsya, Ukraine
| | - Dmytro Valeriiovych Dmytriiev
- Department of Anesthesiology, Intensive care, and Emergency Medicine, National Pirogov Memorial Medical University, Vinnytsya, Ukraine
| | | | - Vira Volodymyrivna Bebyk
- Department of Microbiology, Virology and Immunology, National Pirogov Memorial Medical University, Vinnytsya, Ukraine
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4
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Meng Q, Lin F, Ling B. In Vitro Activity of Peptide Antibiotics in Combination With Other Antimicrobials on Extensively Drug-Resistant Acinetobacter baumannii in the Planktonic and Biofilm Cell. Front Pharmacol 2022; 13:890955. [PMID: 35645826 PMCID: PMC9130746 DOI: 10.3389/fphar.2022.890955] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/28/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii is one of the most dangerous opportunistic pathogens in the global health care setup. Its drug resistance and biofilm-forming capability are often associated with chronic infections that are difficult to treat. Therefore, the clinical treatments for highly drug-resistant A. baumannii are limited. Antimicrobial peptides are broad-spectrum antibacterial agents combined with antibiotics that minimize selective bacterial resistance and enhance antibacterial efficacy. The current study evaluated the synergistic antibacterial activities of clinically important peptide antibiotics combined with other antimicrobials against nine extensively drug-resistant A. baumannii strains in planktonic and biofilm cells in vitro. Polymyxin B and E combined with imipenem showed 100% synergy in the planktonic cell with the checkerboard. Moreover, polymyxin E with rifampicin and bacitracin with imipenem or meropenem showed 100% additive effects. In the biofilm cell, polymyxin B and E combined with azithromycin showed 100% synergy, when vancomycin with azithromycin, rifampicin, and bacitracin with azithromycin or rifampicin, and teicoplanin with tigecycline or rifampicin, all showed 100% additive effects. Therefore, peptide antibiotics combined with other antimicrobials have synergistic or additive effects on extensively drug-resistant A. baumannii in planktonic and biofilm cells. In addition, the combination of polymyxins with carbapenems or azithromycin could be an ideal therapy against extensively drug-resistant A. baumannii infections.
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Affiliation(s)
- Qianlin Meng
- Sichuan Province College Key Laboratory of Structure-Specific Small Molecule Drugs, Chengdu Medical College, Chengdu, China
- School of Pharmacy, Chengdu Medical College, Chengdu, China
| | - Fei Lin
- Sichuan Province College Key Laboratory of Structure-Specific Small Molecule Drugs, Chengdu Medical College, Chengdu, China
- Department of Pharmacy, The First Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | - Baodong Ling
- Sichuan Province College Key Laboratory of Structure-Specific Small Molecule Drugs, Chengdu Medical College, Chengdu, China
- School of Pharmacy, Chengdu Medical College, Chengdu, China
- *Correspondence: Baodong Ling,
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5
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Search for a Shared Genetic or Biochemical Basis for Biofilm Tolerance to Antibiotics across Bacterial Species. Antimicrob Agents Chemother 2022; 66:e0002122. [PMID: 35266829 DOI: 10.1128/aac.00021-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Is there a universal genetically programmed defense providing tolerance to antibiotics when bacteria grow as biofilms? A comparison between biofilms of three different bacterial species by transcriptomic and metabolomic approaches uncovered no evidence of one. Single-species biofilms of three bacterial species (Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii) were grown in vitro for 3 days and then challenged with respective antibiotics (ciprofloxacin, daptomycin, and tigecycline) for an additional 24 h. All three microorganisms displayed reduced susceptibility in biofilms compared to planktonic cultures. Global transcriptomic profiling of gene expression comparing biofilm to planktonic and antibiotic-treated biofilm to untreated biofilm was performed. Extracellular metabolites were measured to characterize the utilization of carbon sources between biofilms, treated biofilms, and planktonic cells. While all three bacteria exhibited a species-specific signature of stationary phase, no conserved gene, gene set, or common functional pathway could be identified that changed consistently across the three microorganisms. Across the three species, glucose consumption was increased in biofilms compared to planktonic cells, and alanine and aspartic acid utilization were decreased in biofilms compared to planktonic cells. The reasons for these changes were not readily apparent in the transcriptomes. No common shift in the utilization pattern of carbon sources was discerned when comparing untreated to antibiotic-exposed biofilms. Overall, our measurements do not support the existence of a common genetic or biochemical basis for biofilm tolerance against antibiotics. Rather, there are likely myriad genes, proteins, and metabolic pathways that influence the physiological state of individual microorganisms in biofilms and contribute to antibiotic tolerance.
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6
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Lazar V, Holban AM, Curutiu C, Chifiriuc MC. Modulation of Quorum Sensing and Biofilms in Less Investigated Gram-Negative ESKAPE Pathogens. Front Microbiol 2021; 12:676510. [PMID: 34394026 PMCID: PMC8359898 DOI: 10.3389/fmicb.2021.676510] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/30/2021] [Indexed: 01/20/2023] Open
Abstract
Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral changes both to the external reservoirs and the infected host, which, in response to microbial colonization, mobilizes equally sophisticated anti-infectious strategies. One of the most important adaptive processes is the ability of pathogenic bacteria to turn from the free, floating, or planktonic state to the adherent one and to develop biofilms on alive and inert substrata; this social lifestyle, based on very complex communication networks, namely, the quorum sensing (QS) and response system, confers them an increased phenotypic or behavioral resistance to different stress factors, including host defense mechanisms and antibiotics. As a consequence, biofilm infections can be difficult to diagnose and treat, requiring complex multidrug therapeutic regimens, which often fail to resolve the infection. One of the most promising avenues for discovering novel and efficient antibiofilm strategies is targeting individual cells and their QS mechanisms. A huge amount of data related to the inhibition of QS and biofilm formation in pathogenic bacteria have been obtained using the well-established gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa models. The purpose of this paper was to revise the progress on the development of antibiofilm and anti-QS strategies in the less investigated gram-negative ESKAPE pathogens Klebsiella pneumoniae, Acinetobacter baumannii, and Enterobacter sp. and identify promising leads for the therapeutic management of these clinically significant and highly resistant opportunistic pathogens.
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Affiliation(s)
- Veronica Lazar
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
| | - Alina Maria Holban
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
| | - Carmen Curutiu
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
| | - Mariana Carmen Chifiriuc
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
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7
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Nocera FP, Attili AR, De Martino L. Acinetobacter baumannii: Its Clinical Significance in Human and Veterinary Medicine. Pathogens 2021; 10:pathogens10020127. [PMID: 33513701 PMCID: PMC7911418 DOI: 10.3390/pathogens10020127] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/13/2021] [Accepted: 01/24/2021] [Indexed: 02/06/2023] Open
Abstract
Acinetobacter baumannii is a Gram-negative, opportunistic pathogen, causing severe infections difficult to treat. The A. baumannii infection rate has increased year by year in human medicine and it is also considered as a major cause of nosocomial infections worldwide. This bacterium, also well known for its ability to form biofilms, has a strong environmental adaptability and the characteristics of multi-drug resistance. Indeed, strains showing fully resistant profiles represent a worrisome problem in clinical therapeutic treatment. Furthermore, A. baumannii-associated veterinary nosocomial infections has been reported in recent literature. Particularly, carbapenem-resistant A. baumannii can be considered an emerging opportunistic pathogen in human medicine as well as in veterinary medicine.
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Affiliation(s)
- Francesca Paola Nocera
- Department of Veterinary Medicine and Animal Production, University of Naples “Federico II”, 80137 Naples, Italy;
| | - Anna-Rita Attili
- School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy;
| | - Luisa De Martino
- Department of Veterinary Medicine and Animal Production, University of Naples “Federico II”, 80137 Naples, Italy;
- Correspondence:
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8
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Ušjak D, Dinić M, Novović K, Ivković B, Filipović N, Stevanović M, Milenković MT. Methoxy-Substituted Hydroxychalcone Reduces Biofilm Production, Adhesion and Surface Motility of Acinetobacter baumannii by Inhibiting ompA Gene Expression. Chem Biodivers 2020; 18:e2000786. [PMID: 33188577 DOI: 10.1002/cbdv.202000786] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/13/2020] [Indexed: 12/22/2022]
Abstract
An increasing lack of available therapeutic options against Acinetobacter baumannii urged researchers to seek alternative ways to fight this extremely resistant nosocomial pathogen. Targeting its virulence appears to be a promising strategy, as it offers considerably reduced selection of resistant mutants. In this study, we tested antibiofilm potential of four synthetic chalcone derivatives against A. baumannii. Compound that showed the greatest activity was selected for further evaluation of its antivirulence properties. Real-time PCR was used to evaluate mRNA expression of biofilm-associated virulence factor genes (ompA, bap, abaI) in treated A. baumannii strains. Also, we examined virulence properties related to the expression of these genes, such as fibronectin- and collagen-mediated adhesion, surface motility, and quorum-sensing activity. The results revealed that the expression of all tested genes is downregulated together with the reduction of adhesion and motility. The conclusion is that 2'-hydroxy-2-methoxychalcone exhibits antivirulence activity against A. baumannii by inhibiting the expression of ompA and bap genes, which is reflected in reduced biofilm formation, adhesion, and surface motility.
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Affiliation(s)
- Dušan Ušjak
- Department of Microbiology and Immunology, University of Belgrade - Faculty of Pharmacy, Vojvode Stepe 450, 11221, Belgrade, Serbia
| | - Miroslav Dinić
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444/a, 11010, Belgrade, Serbia
| | - Katarina Novović
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444/a, 11010, Belgrade, Serbia
| | - Branka Ivković
- Department of Pharmaceutical Chemistry, University of Belgrade - Faculty of Pharmacy, Vojvode Stepe 450, 11221, Belgrade, Serbia
| | - Nenad Filipović
- Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11000, Belgrade, Serbia
| | - Magdalena Stevanović
- Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11000, Belgrade, Serbia
| | - Marina T Milenković
- Department of Microbiology and Immunology, University of Belgrade - Faculty of Pharmacy, Vojvode Stepe 450, 11221, Belgrade, Serbia
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9
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Yero D, Huedo P, Conchillo-Solé O, Martínez-Servat S, Mamat U, Coves X, Llanas F, Roca I, Vila J, Schaible UE, Daura X, Gibert I. Genetic Variants of the DSF Quorum Sensing System in Stenotrophomonas maltophilia Influence Virulence and Resistance Phenotypes Among Genotypically Diverse Clinical Isolates. Front Microbiol 2020; 11:1160. [PMID: 32582100 PMCID: PMC7283896 DOI: 10.3389/fmicb.2020.01160] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 05/06/2020] [Indexed: 12/16/2022] Open
Abstract
The pathogenicity of Stenotrophomonas maltophilia is regulated in part by its quorum sensing (QS) system. The main QS signaling molecule in S. maltophilia is known as diffusible signal factor (DSF), and the rpf gene cluster is responsible for its synthesis and perception. Two cluster variants have been previously described, rpf-1 and rpf-2, which differ basically in the conditions under which DSF is produced. Here, correlations between the rpf variant and antibiotic susceptibility, LPS electrophoretic profiles and virulence-related phenotypes were evaluated for a collection of 78 geographically and genetically diverse clinical strains of S. maltophilia. In general there were associations between previously established genogroups and the genetic variant of the rpf cluster. However, only few genotype-phenotype correlations could be observed. Resistance to the β-lactam antibiotics ceftazidime and ticarcillin was associated with strains carrying the rpf-1 variant, whereas strains of variant rpf-2, particularly those of genogroup C, showed higher resistance levels to colistin. Strains of variant rpf-2 were also significantly more virulent to Galleria mellonella larvae than those of rpf-1, most likely due to an increased ability of rpf-2 strains to form biofilms. A comparative genomic analysis revealed the presence of proteins unique to individual genogroups. In particular, the strains of genogroup C share an operon that encodes for a new virulence determinant in S. maltophilia related to the synthesis of an alternative Flp/Tad pilus. Overall, this study establishes a link between the DSF-based QS system and the virulence and resistance phenotypes in this species, and identifies potential high-risk clones circulating in European hospitals.
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Affiliation(s)
- Daniel Yero
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Pol Huedo
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Oscar Conchillo-Solé
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Sònia Martínez-Servat
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Uwe Mamat
- Cellular Microbiology, Priority Research Area Infections, Research Center Borstel - Leibniz Lung Center, Borstel, Germany
| | - Xavier Coves
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Ferran Llanas
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Ignasi Roca
- Department of Clinical Microbiology-ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Jordi Vila
- Department of Clinical Microbiology-ISGlobal, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Ulrich E Schaible
- Cellular Microbiology, Priority Research Area Infections, Research Center Borstel - Leibniz Lung Center, Borstel, Germany
| | - Xavier Daura
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Isidre Gibert
- Institut de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
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10
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Lin MF, Lin YY, Lan CY. Characterization of biofilm production in different strains of Acinetobacter baumannii and the effects of chemical compounds on biofilm formation. PeerJ 2020; 8:e9020. [PMID: 32523805 PMCID: PMC7261477 DOI: 10.7717/peerj.9020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/28/2020] [Indexed: 12/23/2022] Open
Abstract
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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Affiliation(s)
- Ming-Feng Lin
- Department of Medicine, National Taiwan University Hospital Chu-Tung Branch, Hsinchu County, Taiwan
| | - Yun-You Lin
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Chung-Yu Lan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan.,Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
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11
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Martínez-Servat S, Yero D, Huedo P, Marquez R, Molina G, Daura X, Gibert I. Heterogeneous Colistin-Resistance Phenotypes Coexisting in Stenotrophomonas maltophilia Isolates Influence Colistin Susceptibility Testing. Front Microbiol 2018; 9:2871. [PMID: 30524420 PMCID: PMC6262003 DOI: 10.3389/fmicb.2018.02871] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 11/08/2018] [Indexed: 11/21/2022] Open
Abstract
The polymyxin antibiotic colistin shows in vitro activity against Stenotrophomonas maltophilia. However, an increased incidence of colistin-resistant isolates has been recently observed. In addition, in vitro evaluation of colistin susceptibility for this organism has been problematic. The aims of this study were to investigate the colistin-resistance phenotypes displayed by S. maltophilia and their potential association with the challenging determination of colistin susceptibilities for this organism by even the recommended method. Colistin-resistance phenotypes were inferred by use of the recommended broth microdilution method in different clinical isolates of S. maltophilia. Most of the strains showed non-interpretable minimum inhibitory concentrations (MICs) for colistin due to an incomplete growth inhibition in wells of the microdilution plate. In addition, the subpopulation of bacteria resistant to colistin showed an increased ability to form biofilms on the plastic surface of MIC plates. The observed incomplete growth inhibition in the microdilution plates is compatible with a progressive adaptation to colistin or a heterogeneous susceptibility to this antibiotic. Therefore, to determine the existence of heteroresistance or adaptive resistance, four colistin-resistant clinical isolates were subjected to serial Etest assays, growth rate analyses, and the population analysis profile test. The experiments indicated that these S. maltophilia isolates display a colistin-resistant sub-population that survives and multiplies in the presence of the antibiotic. Interestingly, this phenomenon might not be explainable by the natural background mutation rate alone since the development of a resistant sub-population occurred upon the contact with the antibiotic and it was reversible. This complex colistin-resistance phenotype is exhibited differently by the different isolates and significantly affected colistin susceptibility testing. Furthermore, it can coexist with adaptive resistance to colistin as response to pre-incubation with sub-inhibitory concentrations of the antibiotic. Overall, the combined action of heterogeneous colistin-resistance mechanisms in S. maltophilia isolates, including colistin-induced biofilm formation, may hamper the correct interpretation of colistin susceptibility tests, thus having potentially serious implications on antimicrobial-therapy decision making.
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Affiliation(s)
- Sònia Martínez-Servat
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Daniel Yero
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Pol Huedo
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Roser Marquez
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Gara Molina
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Xavier Daura
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,Catalan Institution for Research and Advanced Studies, Barcelona, Spain
| | - Isidre Gibert
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Barcelona, Spain.,Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Barcelona, Spain
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12
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Eze EC, Chenia HY, El Zowalaty ME. Acinetobacter baumannii biofilms: effects of physicochemical factors, virulence, antibiotic resistance determinants, gene regulation, and future antimicrobial treatments. Infect Drug Resist 2018; 11:2277-2299. [PMID: 30532562 PMCID: PMC6245380 DOI: 10.2147/idr.s169894] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Acinetobacter baumannii is a leading cause of nosocomial infections due to its increased antibiotic resistance and virulence. The ability of A. baumannii to form biofilms contributes to its survival in adverse environmental conditions including hospital environments and medical devices. A. baumannii has undoubtedly propelled the interest of biomedical researchers due to its broad range of associated infections especially in hospital intensive care units. The interplay among microbial physicochemistry, alterations in the phenotype and genotypic determinants, and the impact of existing ecological niche and the chemistry of antimicrobial agents has led to enhanced biofilm formation resulting in limited access of drugs to their specific targets. Understanding the triggers to biofilm formation is a step towards limiting and containing biofilm-associated infections and development of biofilm-specific countermeasures. The present review therefore focused on explaining the impact of environmental factors, antimicrobial resistance, gene alteration and regulation, and the prevailing microbial ecology in A. baumannii biofilm formation and gives insights into prospective anti-infective treatments.
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Affiliation(s)
- Emmanuel C Eze
- Virology and Microbiology Research Group, School of Health Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa,
| | - Hafizah Y Chenia
- Discipline of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Mohamed E El Zowalaty
- Virology and Microbiology Research Group, School of Health Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa,
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13
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Mangal S, Xu R, Park H, Zemlyanov D, Shetty N, Lin YW, Morton D, Chan HK, Li J, Zhou QT. Understanding the Impacts of Surface Compositions on the In-Vitro Dissolution and Aerosolization of Co-Spray-Dried Composite Powder Formulations for Inhalation. Pharm Res 2018; 36:6. [PMID: 30406281 DOI: 10.1007/s11095-018-2527-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/17/2018] [Indexed: 01/26/2023]
Abstract
PURPOSE Dissolution behavior of dry powder inhaler (DPI) antibiotic formulations in the airways may affect their efficacy especially for poorly-soluble antibiotics such as azithromycin. The main objective of this study was to understand the effects of surface composition on the dissolution of spray dried azithromycin powders by itself and in combination with colistin. METHODS Composite formulations of azithromycin (a poorly water-soluble molecule) and colistin (a water-soluble molecule) were produced by spray drying. The resultant formulations were characterized for particle size, morphology, surface composition, solid-state properties, solubility and dissolution. RESULTS The results demonstrate that surfaces composition has critical impacts on the dissolution of composite formulations. Colistin was shown to increase the solubility of azithromycin. For composite formulations with no surface colistin, azithromycin released at a similar dissolution rate as the spray-dried azithromycin alone. An increase in surface colistin concentration was shown to accelerate the dissolution of azithromycin. The dissolution of colistin from the composite formulations was significantly slower than the spray-dried pure colistin. In addition, FTIR spectrum showed intermolecular interactions between azithromycin and colistin in the composite formulations, which could contribute to the enhanced solubility and dissolution of azithromycin. CONCLUSIONS Our study provides fundamental understanding of the effects of surface concentration of colistin on azithromycin dissolution of co-spray-dried composite powder formulations.
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Affiliation(s)
- Sharad Mangal
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana, 47907, USA
| | - Rongkun Xu
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana, 47907, USA
| | - Heejun Park
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana, 47907, USA
| | - Dmitry Zemlyanov
- Birck Nanotechnology Center, Purdue University, 1205 West State Street, West Lafayette, Indiana, 47907, USA
| | - Nivedita Shetty
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana, 47907, USA
| | - Yu-Wei Lin
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia
| | - David Morton
- Drug Delivery, Dynamics & Deposition, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC, 3052, Australia
| | - Hak-Kim Chan
- Advanced Drug Delivery Group, Faculty of Pharmacy, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Jian Li
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, VIC, 3800, Australia
| | - Qi Tony Zhou
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana, 47907, USA.
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14
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Feng J, Liu B, Xu J, Wang Q, Huang L, Ou W, Gu J, Wu J, Li S, Zhuo C, Zhou Y. In vitro effects of N-acetylcysteine alone and combined with tigecycline on planktonic cells and biofilms of Acinetobacter baumannii. J Thorac Dis 2018; 10:212-218. [PMID: 29600051 DOI: 10.21037/jtd.2017.11.130] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Acinetobacter baumannii (A. baumannii), as a common opportunistic pathogen, has strong ability to form biofilms, which has led to drug resistance and chronic infections. The combination of N-acetylcysteine (NAC) and tigecycline (TGC) was demonstrated to synergistically inhibit biofilm-associated bacterial infections, including methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. The purpose of this study is to investigate the effect of NAC and TGC on planktonic cells and biofilms of A. baumannii. Methods Minimum inhibitory concentrations (MICs) of NAC were determined by broth microdilution method. Biofilm susceptibility was assessed by crystal violet stain. Interactive effects of NAC and TGC on planktonic cells were determined by checkerboard MIC assay. Viable cell count was used to evaluate the combined effect of NAC and TGC on biofilm-embedded bacteria. Results MICs of NAC against 25 A. baumannii isolates ranged from 16 to 128 mg/mL. NAC alone (0.5-128 mg/mL) significantly inhibited biofilm formation and disrupted preformed biofilms. The combination of NAC and TGC induced a partial synergistic effect (60%) and additive effect (28%) on planktonic bacteria. For biofilm-embedded bacteria, treatment with 16 mg/mL NAC alone or 2 µg/mL TGC alone resulted in significant bactericidal effects (P<0.01 and P<0.05, respectively); synergistic bactericidal effect was found at 4 mg/mL NAC combined with 0.5 µg/mL TGC (P<0.01). Conclusions NAC alone significantly inhibited biofilm formation of A. baumannii. The combination of NAC and TGC induced partial synergistic effect against planktonic cells and synergistic effect against biofilm-embedded A. baumannii, which might be a therapeutic option for biofilm-related infections of A. baumannii.
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Affiliation(s)
- Jinlun Feng
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Baomo Liu
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Junwen Xu
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Qinqin Wang
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Lixia Huang
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Weijun Ou
- Center of Organ Transplantation, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Jincui Gu
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Jian Wu
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Shaoli Li
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Chao Zhuo
- State Key Laboratory of Respiratory Diseases, Guangzhou Medical College, Guangzhou 511436, China
| | - Yanbin Zhou
- Department of Respiratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
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15
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Ryu SY, Baek WK, Kim HA. Association of biofilm production with colonization among clinical isolates of Acinetobacter baumannii. Korean J Intern Med 2017; 32:345-351. [PMID: 27653617 PMCID: PMC5339464 DOI: 10.3904/kjim.2015.287] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 11/03/2015] [Accepted: 04/05/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND/AIMS The pathogen Acinetobacter baumannii is increasingly causing healthcare-associated infections worldwide, particularly in intensive care units. Biofilm formation, a factor contributing to the virulence of A. baumannii, is associated with long-term persistence in hospital environments. The present study investigates the clinical impact of biofilm production on colonization and acquisition after patient admission. METHODS Forty-nine A. baumannii isolates were obtained between August and November 2013 from Keimyung University Dongsan Medical Center, Daegu, Korea. All isolates were obtained from sputum samples of new patients infected or colonized by A. baumannii. The microtiter plate assay was used to determine biofilm formation. RESULTS Twenty-four A. baumannii isolates (48%) demonstrated enhanced biofilm formation capacity than that of the standard A. baumannii strain (ATCC 19606). All isolates were resistant to carbapenem, 38 isolates (77%) were collected from patients in an intensive care unit, and 47 isolates (95%) were from patients who had been exposed to antibiotics in the previous month. The median duration of colonization was longer for biofilm-producing isolates than that of the biofilm non-biofilm producing isolates (18 days vs. 12 days, p < 0.05). Simultaneous colonization with other bacteria was more common for biofilm-producing isolates than that for the non-biofilm producing isolates. The most prevalent co-colonizing bacteria was Staphylococcus aureus. CONCLUSIONS Biofilm-producing isolates seem to colonize the respiratory tract for longer durations than the non-biofilm producing isolates. During colonization, biofilm producers promote co-colonization by other bacteria, particularly S. aureus. Additional research is required to determine possible links between biofilm formation and nosocomial infection.
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Affiliation(s)
- Seong Yeol Ryu
- Department of Infectious Diseases, Keimyung University Dongsan Medical Center, Daegu, Korea
| | - Won-Ki Baek
- Department of Microbiology, Keimyung University School of Medicine, Daegu, Korea
| | - Hyun Ah Kim
- Department of Infectious Diseases, Keimyung University Dongsan Medical Center, Daegu, Korea
- Correspondence to Hyun Ah Kim, M.D. Department of Infectious Disease, Keimyung University Dongsan Medical Center, 56 Dalseong-ro, Jung-gu, Daegu 41931, Korea Tel: +82-53-250-7892 Fax: +82-53-250-7434 E-mail:
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