Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> Isolates
In order to understand the role of biofilm in the emergence of antibiotic resistance, a total of 104 clinical <i>Acinetobacter baumannii</i> strains were investigated for their biofilm-forming capacities and genes associated with biofilm formation. Selected biofilm-formers were tested fo...
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| Format: | Article |
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MDPI AG
2020-11-01
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| Series: | Antibiotics |
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| Online Access: | https://www.mdpi.com/2079-6382/9/11/817 |
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| author | Abebe Mekuria Shenkutie Mian Zhi Yao Gilman Kit-hang Siu Barry Kin Chung Wong Polly Hang-mei Leung |
| author_facet | Abebe Mekuria Shenkutie Mian Zhi Yao Gilman Kit-hang Siu Barry Kin Chung Wong Polly Hang-mei Leung |
| author_sort | Abebe Mekuria Shenkutie |
| collection | DOAJ |
| description | In order to understand the role of biofilm in the emergence of antibiotic resistance, a total of 104 clinical <i>Acinetobacter baumannii</i> 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 <i>bap</i>, <i>csuE</i>, and <i>abaI</i> 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 <i>Acinetobacter baumannii</i> 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. |
| first_indexed | 2024-03-10T14:47:50Z |
| format | Article |
| id | doaj.art-7dbfa6fa0ea74597822e7cf7d9bec2be |
| institution | Directory Open Access Journal |
| issn | 2079-6382 |
| language | English |
| last_indexed | 2024-03-10T14:47:50Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Antibiotics |
| spelling | doaj.art-7dbfa6fa0ea74597822e7cf7d9bec2be2023-11-20T21:13:04ZengMDPI AGAntibiotics2079-63822020-11-0191181710.3390/antibiotics9110817Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> IsolatesAbebe Mekuria Shenkutie0Mian Zhi Yao1Gilman Kit-hang Siu2Barry Kin Chung Wong3Polly Hang-mei Leung4Department of Health Technology and Informatics, the Hong Kong Polytechnic University, Hong Kong, ChinaDepartment of Health Technology and Informatics, the Hong Kong Polytechnic University, Hong Kong, ChinaDepartment of Health Technology and Informatics, the Hong Kong Polytechnic University, Hong Kong, ChinaDepartment of Pathology, United Christian Hospital, Hong Kong, ChinaDepartment of Health Technology and Informatics, the Hong Kong Polytechnic University, Hong Kong, ChinaIn order to understand the role of biofilm in the emergence of antibiotic resistance, a total of 104 clinical <i>Acinetobacter baumannii</i> 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 <i>bap</i>, <i>csuE</i>, and <i>abaI</i> 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 <i>Acinetobacter baumannii</i> 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.https://www.mdpi.com/2079-6382/9/11/817<i>Acinetobacter baumannii</i>biofilmantibiotic resistanceantibiotic tolerancepersister |
| spellingShingle | Abebe Mekuria Shenkutie Mian Zhi Yao Gilman Kit-hang Siu Barry Kin Chung Wong Polly Hang-mei Leung Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> Isolates Antibiotics <i>Acinetobacter baumannii</i> biofilm antibiotic resistance antibiotic tolerance persister |
| title | Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> Isolates |
| title_full | Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> Isolates |
| title_fullStr | Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> Isolates |
| title_full_unstemmed | Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> Isolates |
| title_short | Biofilm-Induced Antibiotic Resistance in Clinical <i>Acinetobacter baumannii</i> Isolates |
| title_sort | biofilm induced antibiotic resistance in clinical i acinetobacter baumannii i isolates |
| topic | <i>Acinetobacter baumannii</i> biofilm antibiotic resistance antibiotic tolerance persister |
| url | https://www.mdpi.com/2079-6382/9/11/817 |
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