1
|
Furugaito M, Anraku M, Kawahara R, Hisato A, Kamisako T, Yoshida K. First report of New Delhi metallo-β-lactamase-1-producing Acinetobacter soli in Japan. J Infect Chemother 2023; 29:1177-1180. [PMID: 37482191 DOI: 10.1016/j.jiac.2023.07.009] [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: 05/16/2023] [Revised: 07/13/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023]
Abstract
New Delhi metallo-β-lactamase (NDM)-producing gram-negative rods, including Acinetobacter species, are a global problem but have rarely been isolated in Japan. To our knowledge, this is the first study to isolate an NDM-1-producing Acinetobacter soli strain, KUH106, in Japan. We analyzed this strain using next-generation sequencing to examine the plasmid carrying NDM-1. This plasmid, named pKUH106_NDM1, is 41,135 bp in length and contains genetic contexts with the structure ISAba14-aph(3')-VI-ISAba125-blaNDM-1ble-MBL. Comparative analysis of the plasmid revealed that it resembled the plasmids of Acinetobacter detected in various countries, such as the A. soli isolate from Taiwan and the Acinetobacter baumannii isolate from a healthcare facility in Osaka Prefecture, Japan. These results suggest that blaNDM-1 may spread via this plasmid in Acinetobacter species. This phenomenon needs to be confirmed through the genetic analysis of A. baumannii and other carbapenem-resistant Acinetobacter species. In particular, blaNDM-1 and other resistance genes must be investigated, and the spread of these genes in the community must be cautioned.
Collapse
Affiliation(s)
- Michiko Furugaito
- Department of Clinical Laboratory, Kindai University Hospital, 377-2, Ohno-Higashi, OsakaSayama, Osaka, 589-8511, Japan.
| | - Masaki Anraku
- Division of Microbiology, Bacteriology Section, Osaka Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka-shi, Osaka, 537-0025, Japan
| | - Ryuji Kawahara
- Division of Microbiology, Bacteriology Section, Osaka Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka-shi, Osaka, 537-0025, Japan
| | - Akihiro Hisato
- Division of Infection Control and Prevention, Department of Medical safety management, Kindai University Hospital, 377-2, Ohno-Higashi, OsakaSayama, Osaka, 589-8511, Japan
| | - Toshinori Kamisako
- Department of Clinical Laboratory Medicine, Kindai University Faculty of Medicine, 377-2, Ohno-Higashi, OsakaSayama, Osaka, 589-8511, Japan
| | - Koichiro Yoshida
- Division of Infection Control and Prevention, Department of Medical safety management, Kindai University Hospital, 377-2, Ohno-Higashi, OsakaSayama, Osaka, 589-8511, Japan
| |
Collapse
|
2
|
Hamed SM, Hussein AF, Al-Agamy MH, Radwan HH, Zafer MM. Tn, a novel transposon harboring and in. J Glob Antimicrob Resist 2022; 30:414-417. [DOI: 10.1016/j.jgar.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/25/2022] Open
|
3
|
Belisario JC, Lee HH, Luknauth H, Rigel NW, Martinez LR. Acinetobacter baumannii Strains Deficient in the Clp Chaperone-Protease Genes Have Reduced Virulence in a Murine Model of Pneumonia. Pathogens 2021; 10:pathogens10020204. [PMID: 33668542 PMCID: PMC7917692 DOI: 10.3390/pathogens10020204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 01/05/2023] Open
Abstract
Acinetobacter baumannii has emerged as a significant opportunistic Gram-negative pathogen and causative agent of nosocomial pneumonia especially in immunocompromised individuals in intensive care units. Recent advances to understand the contribution and function of A. baumannii virulence factors in its pathogenesis have begun to elucidate how this bacterium interacts with immune cells and its interesting mechanisms for multi-antibiotic resistance. Taking advantage of the availability of the A. baumannii AB5075 transposon mutant library, we investigated the impact of the A. baumannii Clp genes, which encode for a chaperone-protease responsible for the degradation of misfolded proteins, on bacterial virulence in a model of pneumonia using C57BL/6 mice and survival within J774.16 macrophage-like cells. Clp-protease A. baumannii mutants exhibit decreased virulence in rodents, high phagocytic cell-mediated killing and reduced biofilm formation. Capsular staining showed evidence of encapsulation in A. baumannii AB5075 and Clp-mutant strains. Surprisingly, clpA and clpS mutants displayed irregular cell morphology, which may be important in the biofilm structural deficiencies observed in these strains. Interestingly, clpA showed apical-like growth, proliferation normally observed in filamentous fungi. These findings provide new information regarding A. baumannii pathogenesis and may be important for the development of therapies intended at reducing morbidity and mortality associated with this remarkable pathogen.
Collapse
Affiliation(s)
- J Christian Belisario
- Department of Physical Medicine and Rehabilitation, University of Pennsylvania, Philadelphia, PA 19146, USA;
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA;
| | - Hiu Ham Lee
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA;
| | - Harshani Luknauth
- Department of Biology, Hofstra University, Hempstead, NY 11549, USA; (H.L.); (N.W.R.)
| | - Nathan W. Rigel
- Department of Biology, Hofstra University, Hempstead, NY 11549, USA; (H.L.); (N.W.R.)
| | - Luis R. Martinez
- Department of Biomedical Sciences, NYIT College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY 11568, USA;
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, FL 32610, USA
- Correspondence:
| |
Collapse
|
4
|
Aris P, Boroumand MA, Douraghi M. Amikacin resistance due to the aphA6 gene in multi-antibiotic resistant Acinetobacter baumannii isolates belonging to global clone 1 from Iran. BMC Microbiol 2019; 19:221. [PMID: 31533627 PMCID: PMC6751817 DOI: 10.1186/s12866-019-1592-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 09/09/2019] [Indexed: 02/08/2023] Open
Abstract
Background TnaphA6-carrying repAci6 plasmids have been detected in Acinetobacter baumannii isolates belonging to global clones, GC1 and GC2, worldwide. Here, we examined whether RepAci6 plasmids family play a role in the dissemination of the aphA6 in GC1 A. baumannii isolates from Iran. Results We found that 22 isolates carried the repAci6 gene, suggesting that they contain a RepAci6 plasmid family. Using the primers linking the aphA6 gene to the backbone of repAci6 plasmid, it was revealed that 16 isolates from different hospitals harbored TnaphA6 on a repAci6 plasmid. Conclusions This study provides evidence for the dissemination of TnaphA6 on the plasmids encoding RepAci6 in Iranian A. baumannii isolates. Furthermore, it seems that TnaphA6 might be acquired by distinct plasmids separately as it was found to be located on the variants of repAci6 plasmids.
Collapse
Affiliation(s)
- Parisa Aris
- Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, PO Box: 14155-6446, Tehran, Iran
| | - Mohammad Ali Boroumand
- Department of Pathology, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoumeh Douraghi
- Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, PO Box: 14155-6446, Tehran, Iran. .,Food Microbiology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
5
|
Novel Aminoglycoside Resistance Transposons and Transposon-Derived Circular Forms Detected in Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates. Antimicrob Agents Chemother 2016; 60:1801-18. [PMID: 26824943 PMCID: PMC4776018 DOI: 10.1128/aac.02143-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 12/16/2015] [Indexed: 12/15/2022] Open
Abstract
Acinetobacter baumannii has emerged as an important opportunistic pathogen equipped with a growing number of antibiotic resistance genes. Our study investigated the molecular epidemiology and antibiotic resistance features of 28 consecutive carbapenem-resistant clinical isolates of A. baumannii collected throughout Sweden in 2012 and 2013. The isolates mainly belonged to clonal complexes (CCs) with an extensive international distribution, such as CC2 (n = 16) and CC25 (n = 7). Resistance to carbapenems was related to blaOXA-23 (20 isolates), blaOXA-24/40-like (6 isolates), blaOXA-467 (1 isolate), and ISAba1-blaOXA-69 (1 isolate). Ceftazidime resistance was associated with blaPER-7 in the CC25 isolates. Two classical point mutations were responsible for resistance to quinolones in all the isolates. Isolates with high levels of resistance to aminoglycosides carried the 16S rRNA methylase armA gene. The isolates also carried a variety of genes encoding aminoglycoside-modifying enzymes. Several novel structures involved in aminoglycoside resistance were identified, including Tn6279, ΔTn6279, Ab-ST3-aadB, and different assemblies of Tn6020 and TnaphA6. Importantly, a number of circular forms related to the IS26 or ISAba125 composite transposons were detected. The frequent occurrence of these circular forms in the populations of several isolates indicates a potential role of these circular forms in the dissemination of antibiotic resistance genes.
Collapse
|
6
|
Esterly JS, Richardson CL, Eltoukhy NS, Qi C, Scheetz MH. Genetic Mechanisms of Antimicrobial Resistance of Acinetobacter baumannii. Ann Pharmacother 2015; 45:218-28. [PMID: 21304033 DOI: 10.1345/aph.1p084] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To summarize published data identifying known genetic mechanisms of antibiotic resistance in Acinetobacter baumannii and the correlating phenotypic expression of antibiotic resistance. DATA SOURCES MEDLINE databases (1966-July 15, 2010) were searched to identify original reports of genetic mechanisms of antibiotic resistance in A. baumannii. DATA SYNTHESIS Numerous genetic mechanisms of resistance to multiple classes of antibiotics are known to exist in A. baumannii, a gram-negative bacterium increasingly implicated in nosocomial infections. Mechanisms may be constitutive or acquired via plasmids, integrons, and transposons. Methods of resistance include enzymatic modification of antibiotic molecules, modification of antibiotic target sites, expression of efflux pumps, and downregulation of cell membrane porin channel expression. Resistance to β-lactams appears to be primarily caused by β-lactamase production, including extended spectrum β-lactamases (b/aTEM, blaSHV, b/aTX-M,b/aKPC), metallo-β-lactamases (blaMP, blaVIM, bla, SIM), and most commonly, oxacillinases (blaOXA). Antibiotic target site alterations confer resistance to fluoroquinolones (gyrA, parC) and aminoglycosides (arm, rmt), and to a much lesser extent, β-lactams. Efflux pumps (tet, ade, abe) contribute to resistance against β-lactams, tetracyclines, fluoroquinolones, and aminoglycosides. Finally, porin channel deletion (carO, oprD) appears to contribute to β-lactam resistance and may contribute to rarely seen polymyxin resistance. Of note, efflux pumps and porin deletions as solitary mechanisms may not render clinical resistance to A. baumannii. CONCLUSIONS A. baumannii possesses copious genetic resistance mechanisms. Knowledge of local genotypes and expressed phenotypes for A. baumannii may aid clinicians more than phenotypic susceptibilities reported in large epidemiologic studies.
Collapse
Affiliation(s)
- John S Esterly
- John S Esterly PharmD BCPS, at time of writing, Infectious Diseases Pharmacotherapy Fellow, Department of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago, Downers Grove, IL; now, Assistant Professor of Pharmacy Practice, College of Pharmacy, Chicago State University, Chicago, IL; Infectious Diseases Pharmacist, Northwestern Memorial Hospital, Chicago
| | - Chad L Richardson
- Chad L Richardson PharmD, at time of writing, Infectious Diseases Pharmacotherapy Resident, Department of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago; now, Solid Organ Transplant Pharmacist, Northwestern Memorial Hospital
| | - Noha S Eltoukhy
- Noha S Eltoukhy PharmD BCPS, at time of writing, Infectious Diseases Pharmacy Resident, Department of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago; Rush University Medical Center, Chicago; now, Infectious DIseases Clinical Pharmacy Specialist, St. Mary Medical Center, Langhorne, PA
| | - Chao Qi
- Chao Qi PhD, Assistant Professor of Pathology, Feinberg School of Medicine, Northwestern University; Assistant Director, Clinical Microbiology Laboratory, Northwestern Memorial Hospital, Chicago
| | - Marc H Scheetz
- Marc H Scheetz PharmD MSc BCPS, Assistant Professor of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago; Infectious Diseases Pharmacist, Northwestern Memorial Hospital
| |
Collapse
|
7
|
Contribution of resistance-nodulation-cell division efflux systems to antibiotic resistance and biofilm formation in Acinetobacter baumannii. mBio 2015; 6:mBio.00309-15. [PMID: 25805730 PMCID: PMC4453527 DOI: 10.1128/mbio.00309-15] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Acinetobacter baumannii is a nosocomial pathogen of increasing importance due to its multiple resistance to antibiotics and ability to survive in the hospital environment linked to its capacity to form biofilms. To fully characterize the contribution of AdeABC, AdeFGH, and AdeIJK resistance-nodulation-cell division (RND)-type efflux systems to acquired and intrinsic resistance, we constructed, from an entirely sequenced susceptible A. baumannii strain, a set of isogenic mutants overexpressing each system following introduction of a point mutation in their cognate regulator or a deletion for the pump by allelic replacement. Pairwise comparison of every derivative with the parental strain indicated that AdeABC and AdeFGH are tightly regulated and contribute to acquisition of antibiotic resistance when overproduced. AdeABC had a broad substrate range, including β-lactams, fluoroquinolones, tetracyclines-tigecycline, macrolides-lincosamides, and chloramphenicol, and conferred clinical resistance to aminoglycosides. Importantly, when combined with enzymatic resistance to carbapenems and aminoglycosides, this pump contributed in a synergistic fashion to the level of resistance of the host. In contrast, AdeIJK was expressed constitutively and was responsible for intrinsic resistance to the same major drug classes as AdeABC as well as antifolates and fusidic acid. Surprisingly, overproduction of AdeABC and AdeIJK altered bacterial membrane composition, resulting in decreased biofilm formation but not motility. Natural transformation and plasmid transfer were diminished in recipients overproducing AdeABC. It thus appears that alteration in the expression of efflux systems leads to multiple changes in the relationship between the host and its environment, in addition to antibiotic resistance. Increased expression of chromosomal genes for RND-type efflux systems plays a major role in bacterial multidrug resistance. Acinetobacter baumannii has recently emerged as an important human pathogen responsible for epidemics of hospital-acquired infections. Besides its remarkable ability to horizontally acquire resistance determinants, it has a broad intrinsic resistance due to low membrane permeability, endogenous resistance genes, and antibiotic efflux. The study of isogenic mutants from a susceptible A. baumannii clinical isolate overproducing or deleted for each of the three major RND-type pumps demonstrated their major contribution to intrinsic resistance and to the synergism between overproduction of an efflux system and acquisition of a resistance gene. We have also shown that modulation of expression of the structural genes for the efflux systems results in numerous alterations in membrane-associated cellular functions, in particular, in a decrease in biofilm formation and resistance gene acquisition.
Collapse
|
8
|
Origin in Acinetobacter guillouiae and dissemination of the aminoglycoside-modifying enzyme Aph(3')-VI. mBio 2014; 5:e01972-14. [PMID: 25336457 PMCID: PMC4212838 DOI: 10.1128/mbio.01972-14] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The amikacin resistance gene aphA6 was first detected in the nosocomial pathogen Acinetobacter baumannii and subsequently in other genera. Analysis of 133 whole-genome sequences covering the taxonomic diversity of Acinetobacter spp. detected aphA6 in the chromosome of 2 isolates of A. guillouiae, which is an environmental species, 1 of 8 A. parvus isolates, and 5 of 34 A. baumannii isolates. The gene was also present in 29 out of 36 A. guillouiae isolates screened by PCR, indicating that it is ancestral to this species. The Pnative promoter for aphA6 in A. guillouiae and A. parvus was replaced in A. baumannii by PaphA6, which was generated by use of the insertion sequence ISAba125, which brought a −35 sequence. Study of promoter strength in Escherichia coli and A. baumannii indicated that PaphA6 was four times more potent than Pnative. There was a good correlation between aminoglycoside MICs and aphA6 transcription in A. guillouiae isolates that remained susceptible to amikacin. The marked topology differences of the phylogenetic trees of aphA6 and of the hosts strongly support its recent direct transfer within Acinetobacter spp. and also to evolutionarily remote bacterial genera. Concomitant expression of aphA6 must have occurred because, contrary to the donors, it can confer resistance to the new hosts. Mobilization and expression of aphA6 via composite transposons and the upstream IS-generating hybrid PaphA6, followed by conjugation, seems the most plausible mechanism. This is in agreement with the observation that, in the recipients, aphA6 is carried by conjugative plasmids and flanked by IS that are common in Acinetobacter spp. Our data indicate that resistance genes can also be found in susceptible environmental bacteria. We speculated that the aphA6 gene for an enzyme that confers resistance to amikacin, the most active aminoglycoside for the treatment of nosocomial infections due to Acinetobacter spp., originated in this genus before disseminating to phylogenetically distant genera pathogenic for humans. Using a combination of whole-genome sequencing of a collection of Acinetobacter spp. covering the breadth of the known taxonomic diversity of the genus, gene cloning, detailed promoter analysis, study of heterologous gene expression, and comparative analysis of the phylogenetic trees of aphA6 and of the bacterial hosts, we found that aphA6 originated in Acinetobacter guillouiae, an amikacin-susceptible environmental species. The gene conferred, upon mobilization, high-level resistance to the new hosts. This work stresses that nonpathogenic bacteria can act as reservoirs of resistance determinants, and it provides an example of the use of a genomic library to study the origin and dissemination of an antibiotic resistance gene to human pathogens.
Collapse
|
9
|
Nigro SJ, Hall RM. Amikacin resistance plasmids in extensively antibiotic-resistant GC2 Acinetobacter baumannii from two Australian hospitals. J Antimicrob Chemother 2014; 69:3435-7. [PMID: 25103493 DOI: 10.1093/jac/dku310] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Steven J Nigro
- School of Molecular Bioscience, The University of Sydney, NSW 2006, Australia
| | - Ruth M Hall
- School of Molecular Bioscience, The University of Sydney, NSW 2006, Australia
| |
Collapse
|
10
|
Saranathan R, Sudhakar P, Karthika RU, Singh SK, Shashikala P, Kanungo R, Prashanth K. Multiple drug resistant carbapenemases producing Acinetobacter baumannii isolates harbours multiple R-plasmids. Indian J Med Res 2014; 140:262-70. [PMID: 25297360 PMCID: PMC4216501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND & OBJECTIVES The nosocomial human pathogen Acinetobacter baumannii has high propensity to develop resistance to antimicrobials and to become multidrug resistant (MDR), consequently complicating the treatment. This study was carried out to investigate the presence of resistant plasmids (R-plasmids) among the clinical isolates of A. baumannii. In addition, the study was performed to check the presence of common β-lactamases encoding genes on these plasmids. METHODS A total of 55 clinical isolates of A. baumannii were included in the study and all were subjected to plasmid DNA isolation, followed by PCR to check the presence of resistance gene determinants such as blaOXA-23, blaOXA-51, blaOXA-58 and blaIMP-1 on these plasmids that encode for oxacillinase (OXA) and metallo-β-lactamase (MBL) type of carbapenemases. Plasmid curing experiments were carried out on selected isolates using ethidium bromide and acridine orange as curing agents and the antibiotic resistance profiles were evaluated before and after curing. RESULTS All the isolates were identified as A. baumannii by 16SrDNA amplification and sequencing. Plasmid DNA isolated from these isolates showed the occurrence of multiple plasmids with size ranging from 500bp to ≥25 kb. The percentage of blaOXA-51 and blaOXA-23 on plasmids were found to be 78 and 42 per cent, respectively and 20 isolates (36%) carried blaIMP-1 gene on plasmids. Significant difference was observed in the antibiograms of plasmid cured isolates when compared to their parental ones. The clinical isolates became susceptible to more than two antibiotic classes after curing of plasmids indicating plasmid borne resistance. INTERPRETATION & CONCLUSIONS Our study determined the plasmid mediated resistance mechanisms and occurrence of different resistance genes on various plasmids isolated from MDR A. baumannii. The present findings showed the evidence for antibiotic resistance mediated through multiple plasmids in A. baumannii clinical isolates. This indicates towards a need for preventive measures to avert the dissemination of plasmid resistance determinants in clinical environments.
Collapse
Affiliation(s)
- Rajagopalan Saranathan
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Pagal Sudhakar
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - R. Uma Karthika
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - Santosh Kumar Singh
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, India
| | - P. Shashikala
- Department of Clinical Microbiology, Pondicherry Institute of Medical Sciences, Puducherry, India
| | - Reba Kanungo
- Department of Clinical Microbiology, Pondicherry Institute of Medical Sciences, Puducherry, India
| | - K. Prashanth
- Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry, India,Reprint requests: Dr Prashanth K, Assistant Professor, Department of Biotechnology, School of Life Sciences Pondicherry University, R. Venkataraman Nagar, Kalapet, Puducherry 605 014, India e-mail:
| |
Collapse
|
11
|
Hamidian M, Hall RM. pACICU2 is a conjugative plasmid of Acinetobacter carrying the aminoglycoside resistance transposon TnaphA6. J Antimicrob Chemother 2013; 69:1146-8. [DOI: 10.1093/jac/dkt488] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
12
|
Hamidian M, Holt KE, Pickard D, Dougan G, Hall RM. A GC1 Acinetobacter baumannii isolate carrying AbaR3 and the aminoglycoside resistance transposon TnaphA6 in a conjugative plasmid. J Antimicrob Chemother 2013; 69:955-8. [PMID: 24235096 PMCID: PMC3956371 DOI: 10.1093/jac/dkt454] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Objectives To locate the acquired antibiotic resistance genes, including the amikacin resistance transposon TnaphA6, in the genome of an Australian isolate belonging to Acinetobacter baumannii global clone 1 (GC1). Methods A multiply antibiotic-resistant GC1 isolate harbouring TnaphA6 was sequenced using Illumina HiSeq, and reads were used to generate a de novo assembly and determine multilocus sequence types (STs). PCR was used to assemble the AbaR chromosomal resistance island and a large plasmid carrying TnaphA6. Plasmid DNA sequences were compared with ones available in GenBank. Conjugation experiments were conducted. Results The A. baumannii GC1 isolate G7 was shown to include the AbaR3 antibiotic resistance island. It also contains an 8.7 kb cryptic plasmid, pAb-G7-1, and a 70 100 bp plasmid, pAb-G7-2, carrying TnaphA6. pAb-G7-2 belongs to the Aci6 Acinetobacter plasmid family. It encodes transfer functions and was shown to conjugate. Plasmids related to pAb-G7-2 were detected in further amikacin-resistant GC1 isolates using PCR. From the genome sequence, isolate G7 was ST1 (Institut Pasteur scheme) and ST231 (Oxford scheme). Using Oxford scheme PCR-based methods, the isolate was ST109 and this difference was traced to a single base difference resulting from the inclusion of the original primers in the gpi segment analysed. Conclusions The multiply antibiotic-resistant GC1 isolate G7 carries most of its resistance genes in AbaR3 located in the chromosome. However, TnaphA6 is on a conjugative plasmid, pAb-G7-2. Primers developed to locate TnaphA6 in pAb-G7-2 will simplify the detection of plasmids related to pAb-G7-2 in A. baumannii isolates.
Collapse
Affiliation(s)
- Mohammad Hamidian
- School of Molecular Bioscience, The University of Sydney, NSW 2006, Australia
| | | | | | | | | |
Collapse
|
13
|
Diene SM, Rolain JM. Investigation of antibiotic resistance in the genomic era of multidrug-resistant Gram-negative bacilli, especially Enterobacteriaceae, Pseudomonas and Acinetobacter. Expert Rev Anti Infect Ther 2013; 11:277-96. [PMID: 23458768 DOI: 10.1586/eri.13.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The increase and spread of multidrug-resistant (MDR) Gram-negative bacteria, including Enterobacteriaceae, Pseudomonas and Acinetobacter species, have become major concerns worldwide. Although the frequent misuse of antibiotic drugs has greatly contributed to worldwide antibiotic resistance by causing a large dispersal of resistance determinants, recent studies demonstrate that these resistance determinants could have emerged from ancient or environmental sources. Moreover, during the last 10 years, we have been witnessing the emergence and development of technologies for high-throughput sequencing, coinciding with an exponential increase in the number of bacterial genomes sequenced. These sequencing technologies allow a complete study of MDR bacterial genomes and are the best way to investigate the genetic determinants of antimicrobial resistance. Accordingly, studies using genome sequencing to decipher resistance determinants in Enterobacteriaceae, Pseudomonas and Acinetobacter species have demonstrated several advantages including, among others: an exhaustive identification of resistance determinants from any clinical, epidemiological or environmental MDR bacterium; identification of the acquisition mechanisms for resistance determinants exchanged between bacterial species through mobile genetic elements and elucidation and understanding, in record time (less than 1 week), of some critical or epidemic events caused by particular pathogenic bacteria. Therefore, it is clear today that the bacterial genome sequencing approach has revolutionized all fields of scientific research and represents a powerful tool to explore the world of microorganisms.
Collapse
Affiliation(s)
- Seydina M Diene
- Aix-Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | | |
Collapse
|
14
|
Shi K, Caldwell SJ, Fong DH, Berghuis AM. Prospects for circumventing aminoglycoside kinase mediated antibiotic resistance. Front Cell Infect Microbiol 2013; 3:22. [PMID: 23805415 PMCID: PMC3691515 DOI: 10.3389/fcimb.2013.00022] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 06/04/2013] [Indexed: 01/10/2023] Open
Abstract
Aminoglycosides are a class of antibiotics with a broad spectrum of antimicrobial activity. Unfortunately, resistance in clinical isolates is pervasive, rendering many aminoglycosides ineffective. The most widely disseminated means of resistance to this class of antibiotics is inactivation of the drug by aminoglycoside-modifying enzymes (AMEs). There are two principal strategies to overcoming the effects of AMEs. The first approach involves the design of novel aminoglycosides that can evade modification. Although this strategy has yielded a number of superior aminoglycoside variants, their efficacy cannot be sustained in the long term. The second approach entails the development of molecules that interfere with the mechanism of AMEs such that the activity of aminoglycosides is preserved. Although such a molecule has yet to enter clinical development, the search for AME inhibitors has been greatly facilitated by the wealth of structural information amassed in recent years. In particular, aminoglycoside phosphotransferases or kinases (APHs) have been studied extensively and crystal structures of a number of APHs with diverse regiospecificity and substrate specificity have been elucidated. In this review, we present a comprehensive overview of the available APH structures and recent progress in APH inhibitor development, with a focus on the structure-guided strategies.
Collapse
Affiliation(s)
- Kun Shi
- Groupe de Recherche Axé sur la Structure des Protéines, Department of Biochemistry, McGill UniversityMontreal, QC, Canada
| | - Shane J. Caldwell
- Groupe de Recherche Axé sur la Structure des Protéines, Department of Biochemistry, McGill UniversityMontreal, QC, Canada
| | - Desiree H. Fong
- Groupe de Recherche Axé sur la Structure des Protéines, Department of Biochemistry, McGill UniversityMontreal, QC, Canada
| | - Albert M. Berghuis
- Groupe de Recherche Axé sur la Structure des Protéines, Department of Biochemistry, McGill UniversityMontreal, QC, Canada
- Department of Microbiology and Immunology, McGill UniversityMontreal, QC, Canada
| |
Collapse
|
15
|
García DC, Catalano M, Piñeiro S, Woloj M, Kaufman S, Sordelli DO. The emergence of resistance to amikacin in Serratia marcescens isolates from patients with nosocomial infection. Int J Antimicrob Agents 2012; 7:203-10. [PMID: 18611757 DOI: 10.1016/s0924-8579(96)00322-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/1996] [Indexed: 11/19/2022]
Abstract
Administration of either amikacin (1985) or gentamicin (1984, 1986-1991) as first-choice aminoglycoside did not decrease the high incidence of amikacin-resistant Serratia marcescens (ARSm) isolates responsible for nosocomial infections at the J.A. Fernández Hospital of Buenos Aires (42% in 1984, 31% in 1985 and 41% in 1987, differences not significant). In addition, a significant peak (P = 0.003) was detected in 1986, with an ARSm incidence of 70%. The incidence of ARSm decreased by 1988-1991 for reasons not related to aminoglycoside use. In the period 1984-1987 all S. marcescens isolates carried the 6'-aminoglycoside-acetyltransferase-Ic [aac(6')-Ic] gene, while in addition 20% of the isolates contained the plasmid-encoded 3'-aminoglycoside-phosphotransferase-VIa[aph(3')-VIa] and 2% the 6'-aminoglycoside-acetyltransferase-Ib [aac(6')-Ib] genes. From 1988 to 1992 resistance to amikacin was associated with only 4 ARSm isolates and correlated with the appearance of Tn1331-related sequences in these isolates. This transposon or related sequences, however, was not widely spread in the S. marcescens population under investigation. Combined use of restriction fragment length polymorphism (RFLP), ribotyping and plasmid profile analysis revealed that S. marcescens strains of the same genotype, including isolates either expressing or not the aac(6')-Ic gene, were involved in outbreaks occurring in May 1984, May 1985 and May 1986. Furthermore, these epidemiological tools permitted discrimination of different S. marcescens clones, each bearing a particular amikacin-resistance marker.
Collapse
Affiliation(s)
- D C García
- Laboratorio BioSidus, Buenos Aires, Argentina; Departamento de Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | | | | | | | | |
Collapse
|
16
|
GES-11, a novel integron-associated GES variant in Acinetobacter baumannii. Antimicrob Agents Chemother 2009; 53:3579-81. [PMID: 19451292 DOI: 10.1128/aac.00072-09] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
New extended-spectrum beta-lactamase GES-11 was detected in Acinetobacter baumannii BM4674. The enzyme conferred resistance to beta-lactams, including aztreonam, and reduced susceptibility to carbapenems. The structural gene was part of a class 1 integron borne by self-transferable plasmid pIP847. GES-type beta-lactamases have not been reported previously in A. baumannii.
Collapse
|
17
|
Dijkshoorn L, Nemec A, Seifert H. An increasing threat in hospitals: multidrug-resistant Acinetobacter baumannii. Nat Rev Microbiol 2007; 5:939-51. [PMID: 18007677 DOI: 10.1038/nrmicro1789] [Citation(s) in RCA: 1274] [Impact Index Per Article: 74.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Since the 1970s, the spread of multidrug-resistant (MDR) Acinetobacter strains among critically ill, hospitalized patients, and subsequent epidemics, have become an increasing cause of concern. Reports of community-acquired Acinetobacter infections have also increased over the past decade. A recent manifestation of MDR Acinetobacter that has attracted public attention is its association with infections in severely injured soldiers. Here, we present an overview of the current knowledge of the genus Acinetobacter, with the emphasis on the clinically most important species, Acinetobacter baumannii.
Collapse
Affiliation(s)
- Lenie Dijkshoorn
- Department of Infectious Diseases C5-P, Leiden University Medical Centre, Albinusdreef 2, P.O. BOX 9600, 2300 RC Leiden, The Netherlands.
| | | | | |
Collapse
|
18
|
Mantengoli E, Rossolini GM. Tn5393d, a complex Tn5393 derivative carrying the PER-1 extended-spectrum beta-lactamase gene and other resistance determinants. Antimicrob Agents Chemother 2005; 49:3289-96. [PMID: 16048938 PMCID: PMC1196282 DOI: 10.1128/aac.49.8.3289-3296.2005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Alcaligenes faecalis FL-424/98, a clinical isolate that produces the PER-1 extended-spectrum beta-lactamase, the bla(PER-1) gene was found to be carried on a 44-kb nonconjugative plasmid, named pFL424, that was transferred to Escherichia coli by electroporation. Investigation of the genetic context of the bla(PER-1) gene in pFL424 by means of a combined cloning and PCR mapping approach revealed that the gene is associated with a transposonlike element of the Tn3 family. This 14-kb element is a Tn5393 derivative of original structure, named Tn5393d, which contains the transposition module and the strAB genes typical of other members of the Tn5393 lineage plus additional resistance determinants, including the bla(PER-1) gene and a new allelic variant of the aphA6 aminoglycoside phosphotransferase gene, named aphA6b, whose product is active against kanamycin, streptomycin, and amikacin. Tn5393d apparently originated from the consecutive insertion of two composite transposons into a Tn5393 backbone carrying the aphA6b and the bla(PER-1) genes, respectively. The putative composite transposon carrying bla(PER-1), named Tn4176, is made of two original and nonidentical insertion sequences of the IS4 family, named IS1387a and IS1387b, of which one is interrupted by the insertion of an original insertion sequence of the IS30 family, named IS1066. In pFL424, Tn5393d is inserted into a Tn501-like mercury resistance transposon. Transposition of Tn5393d or modules thereof containing the bla(PER-1) gene from pFL424 to small multicopy plasmids or to a bacterial artificial chromosome was not detected in an E. coli host harboring both replicons.
Collapse
Affiliation(s)
- Elisabetta Mantengoli
- Dipartimento di Biologia Molecolare, Laboratorio di Fisiologia e Biotecnologia dei Microrganismi, Università di Siena, Policlinico Santa Maria alle Scotte, 53100 Siena, Italy
| | | |
Collapse
|
19
|
Abstract
Politicians and public health officials have joined specialist professionals in recognising antibiotic resistance as a threat to modern medicine. Their response has centred on minimising unnecessary antibiotic prescribing, aiming to reduce selection pressure for resistance. Despite a few hopeful trends (e.g., declining penicillin resistance among pneumococci in the UK), established resistance is proving hard to displace; moreover, new resistances continue to emerge and to proliferate at new sites. There consequently remains a strong need for new antibiotics, particularly those directed against multiresistant Gram-negative bacteria in hospitals. Already some nonfermenters of the genera Acinetobacter and Pseudomonas are resistant to all good antibiotics and many Enterobacteriaceae are resistant to all except carbapenems. There is also a growing need for new agents against community-acquired pathogens, including the agents of tuberculosis, gonorrhoea and urinary tract infections. Unless antibacterial development is re-energised, there is a serious risk that a growing proportion of infections, especially in hospitals, will become effectively untreatable.
Collapse
Affiliation(s)
- D M Livermore
- Antibiotic Resistance Monitoring & Reference Laboratory, Specialist & Reference Microbiology Division, Health Protection Agency, London, UK.
| |
Collapse
|
20
|
Abstract
Aminoglycoside antibiotics have had a major impact on our ability to treat bacterial infections for the past half century. Whereas the interest in these versatile antibiotics continues to be high, their clinical utility has been compromised by widespread instances of resistance. The multitude of mechanisms of resistance is disconcerting but also illuminates how nature can manifest resistance when bacteria are confronted by antibiotics. This article reviews the most recent knowledge about the mechanisms of aminoglycoside action and the mechanisms of resistance to these antibiotics.
Collapse
Affiliation(s)
- Sergei B Vakulenko
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | | |
Collapse
|
21
|
Takahashi A, Yomoda S, Kobayashi I, Okubo T, Tsunoda M, Iyobe S. Detection of carbapenemase-producing Acinetobacter baumannii in a hospital. J Clin Microbiol 2000; 38:526-9. [PMID: 10655339 PMCID: PMC86139 DOI: 10.1128/jcm.38.2.526-529.2000] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii strains resistant to both imipenem (IPM) and ceftazidime (CAZ) were isolated from 1994 through 1996 at Gunma University Hospital. Nine isolates from different inpatients were examined for carbapenem-hydrolyzing activity and for the carbapemase gene bla(IMP) by the PCR method. All nine isolates were carbapenemase-producing strains that hydrolyzed IPM and that harbored bla(IMP). The bla(IMP) gene was transmissible by conjugation to an IPM-susceptible recipient strain of A. baumannii and conferred resistance to IPM, CAZ, cefotaxime (CTX), ampicillin (AMP), and piperacillin (PIP). Either intermediate or high-level resistance to amikacin (AMK) was transferred from two and five strains, respectively, concomitantly with bla(IMP), and gentamicin (GEN) resistance was also transferred in one instance of high-level AMK resistance. Comparative examination of clinical isolates for resistance patterns to nine drugs, IPM, CAZ, CTX, aztreonam, AMP, PIP, AMK, GEN, and norfloxacin, in addition to pulsed-field gel electrophoresis patterns with NotI-digested genomic DNA, confirmed nosocomial transmission of infections involving carbapenemase-producing A. baumannii strains.
Collapse
Affiliation(s)
- A Takahashi
- Department of Laboratory Medicine and Clinical Laboratory Center, Gunma University School of Medicine, 3-39-22, Showa-machi, Maebashi 371-8511, Japan
| | | | | | | | | | | |
Collapse
|
22
|
Vila J, Ruiz J, Navia M, Becerril B, Garcia I, Perea S, Lopez-Hernandez I, Alamo I, Ballester F, Planes AM, Martinez-Beltran J, de Anta TJ. Spread of amikacin resistance in Acinetobacter baumannii strains isolated in Spain due to an epidemic strain. J Clin Microbiol 1999; 37:758-61. [PMID: 9986846 PMCID: PMC84544 DOI: 10.1128/jcm.37.3.758-761.1999] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sixteen amikacin-resistant clinical Acinetobacter baumannii isolates from nine different hospitals in Spain were investigated to determine whether the high incidence of amikacin-resistant A. baumannii was due to the dissemination of an amikacin-resistant strain or to the spread of an amikacin resistance gene. The epidemiological relationship studied by repetitive extragenic palindromic PCR and low-frequency restriction analysis of chromosomal DNA showed that the same clone was isolated in eight of nine hospitals, although other clones were also found. The strains were studied for the presence of the aph(3')-VIa and aac(6')-I genes, which encode enzymes which inactivate amikacin, by PCR. All 16 clinical isolates had positive PCRs with primers specific for the amplification of the aph(3')-VIa gene, whereas none had a positive reaction for the amplification of the aac(6')-I gene. Therefore, the high incidence of amikacin resistance among clinical A. baumannii isolates in Spain was mainly due to an epidemic strain, although the spread of the aph(3')-VI gene cannot be ruled out.
Collapse
Affiliation(s)
- J Vila
- Department de Microbiologia, Institut d' Investigació Biomèdica August Pi i Sunyer, Hospital Clínic, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Daniel C, Haentjens S, Bissinger MC, Courcol RJ. Characterization of the Acinetobacter baumannii Fur regulator: cloning and sequencing of the fur homolog gene. FEMS Microbiol Lett 1999; 170:199-209. [PMID: 9919669 DOI: 10.1111/j.1574-6968.1999.tb13375.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Growth kinetics, siderophore activity and iron-regulated bacterial proteins of Acinetobacter baumannii BM2580 were studied in iron-restricted and iron-supplemented chemically defined media. Iron-regulated outer membrane proteins of 75 kDa and 80 kDa were expressed under iron-restricted conditions. Cloning and sequencing of the complete iron-uptake regulatory (fur) gene from A. baumannii BM2580 is reported for the first time. This gene is preceded by a single autoregulated promoter whose -10 region overlaps the Fur binding site. The open reading frame identified encodes a polypeptide consisting of 145 amino acids. The fur gene is followed by a divergent open reading frame coding for the C-terminus of a putative PilU protein. Sequence analysis indicates that the Fur protein of A. baumannii was 63% identical to the Escherichia coli Fur protein.
Collapse
Affiliation(s)
- C Daniel
- Bacteriology Laboratory, A. Calmette Hospital, Centre Hospitalier Régional et Universitaire, Lille, France.
| | | | | | | |
Collapse
|
24
|
Affiliation(s)
- J A Orsini
- Sections of Surgery, Clinical Studies, University of Pennsylvania, School of Veterinary Medicine, New Bolton Center, Kennett Square, Pennsylvania 19348, USA
| | | |
Collapse
|
25
|
Bergogne-Bérézin E, Towner KJ. Acinetobacter spp. as nosocomial pathogens: microbiological, clinical, and epidemiological features. Clin Microbiol Rev 1996; 9:148-65. [PMID: 8964033 PMCID: PMC172888 DOI: 10.1128/cmr.9.2.148] [Citation(s) in RCA: 1062] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
- E Bergogne-Bérézin
- Department of Microbiology, Bichat-Claude Bernard University Hospital, Paris, France
| | | |
Collapse
|
26
|
Ploy MC, Giamarellou H, Bourlioux P, Courvalin P, Lambert T. Detection of aac(6')-I genes in amikacin-resistant Acinetobacter spp. by PCR. Antimicrob Agents Chemother 1994; 38:2925-8. [PMID: 7695286 PMCID: PMC188310 DOI: 10.1128/aac.38.12.2925] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The distribution of aac(6')-I genes in 62 strains of Acinetobacter spp. resistant to amikacin, netilmicin, and tobramycin and susceptible to gentamicin, a phenotype compatible with synthesis of an AAC(6')-I enzyme, was studied by PCR and by DNA hybridization. Both methods gave similar results. Among the 51 Acinetobacter baumannii strains, aac(6')-Ib was found in 19 isolates and aac(6')-Ih was found in the remaining strains. The aac(6')-Ig gene was present in all 10 A. haemolyticus strains studied and was detected only in this species. A pair of degenerate oligonucleotides complementary to conserved regions of aac(6')-Ic, -Id, -If, -Ig, and -Ih enabled detection of these genes and also of aac(6')-Ij, recently recognized in Acinetobacter sp. strain 13.
Collapse
Affiliation(s)
- M C Ploy
- Unité des Agents Antibactériens, Institut Pasteur, Centre National de la Recherche Scientifique, Paris, France
| | | | | | | | | |
Collapse
|
27
|
Bergogne-Bérézin E. Acinetobacter spp., saprophytic organisms of increasing pathogenic importance. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1994; 281:389-405. [PMID: 7727888 DOI: 10.1016/s0934-8840(11)80326-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Acinetobacter spp. are Gram-negative non-fermentative bacteria commonly present in soil and water as free-living saprophytes; they are isolated as commensals from skin, throat and various secretions of healthy people. There have been frequent changes in their taxonomy so that their pathogenic role in humans has been understood only recently: Acinetobacter has emerged as an important nosocomial pathogen involved in outbreaks of hospital infections. This ubiquitous organism can be recovered from the hospital environment, from colonized or infected patients or from staff (hand carriage). Acinetobacter as an opportunistic pathogen is involved in nosocomial urinary tract infections, bacteremia, wound and burn infections. Its predominant role is observed in nosocomial pneumonia, particularly in fan-associated pneumonia. Acinetobacters are responsible for difficult-to-treat infections due to their frequent multiple resistance to major antibiotics available for the treatment of nosocomial infections. Various mechanisms of resistance to beta-lactams and aminoglycosides have been recognized in these bacteria. Combination therapy is usually recommended for the treatment of nosocomial infections. The increasing pathogenic importance of Acinetobacter spp. and the increasing frequency of hospital outbreaks of acinetobacter infections has made the development of reliable typing methods imperative. Beside conventional "phenotypic" methods (serology, phage typing), genotypic systems (ribotyping, plasmid profiles, pulse-field gel electrophoresis) are currently advancing.
Collapse
Affiliation(s)
- E Bergogne-Bérézin
- Bichat-Claude Bernard University-Hospital, Department of Microbiology, Paris, France
| |
Collapse
|
28
|
Lambert T, Gerbaud G, Courvalin P. Characterization of the chromosomal aac(6')-Ij gene of Acinetobacter sp. 13 and the aac(6')-Ih plasmid gene of Acinetobacter baumannii. Antimicrob Agents Chemother 1994; 38:1883-9. [PMID: 7810994 PMCID: PMC284657 DOI: 10.1128/aac.38.9.1883] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The amikacin resistance genes aac(6')-Ih of Acinetobacter baumannii BM2686 and aac(6')-Ij of Acinetobacter sp. 13 BM2689 encoding aminoglycoside 6'-N-acetyltransferases were characterized. The 441-bp coding sequences predict proteins with calculated masses of 16,698 and 16,677 Da, respectively. Analysis of the deduced amino acid sequences indicated that the proteins belonged to a subfamily of 6'-aminoglycoside acetyltransferase type I enzymes from gram-negative bacteria. The aac(6')-Ih gene of BM2686 was located on a 13.7-kb nonconjugative plasmid. The aac(6')-Ij gene from BM2689 was not transferable either by conjugation to Escherichia coli or A. baumannii or by transformation to Acinetobacter calcoaceticus. Plasmid DNA from BM2689 did not hybridize with an intragenic aac(6')-Ij probe. These results suggest a chromosomal location for this gene. The aac(6')-Ij gene was detected by DNA hybridization in all 28 strains of Acinetobacter sp. 13 tested but not in other Acinetobacter strains, including A. baumannii, proteolytic genospecies 4, 6, 14, 15, 16, and 17, and ungrouped strains. The aac(6')-Ih and -Ij probes did not hybridize in dot blot assays with DNA from members of the families Enterobacteriaceae and Pseudomonadaceae that produced 6'-N-acetyltransferases. These data suggest that the genes are confined to the Acinetobacter genus and that the aac(6')-Ij gene is species specific and may be used to identify Acinetobacter sp. 13.
Collapse
Affiliation(s)
- T Lambert
- Centre d'Etudes Pharmaceutiques, Chatenay-Malabry, France
| | | | | |
Collapse
|
29
|
Lambert T, Gerbaud G, Courvalin P. Characterization of transposon Tn1528, which confers amikacin resistance by synthesis of aminoglycoside 3'-O-phosphotransferase type VI. Antimicrob Agents Chemother 1994; 38:702-6. [PMID: 8031033 PMCID: PMC284528 DOI: 10.1128/aac.38.4.702] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Providencia stuartii BM2667, which was isolated from an abdominal abscess, was resistant to amikacin by synthesis of aminoglycoside 3'-O-phosphotransferase type VI. The corresponding gene, aph(3')-VIa, was carried by a 30-kb self-transferable plasmid of incompatibility group IncN. The resistance gene was cloned into pUC18, and the recombinant plasmid, pAT246, was transformed into Escherichia coli DH1 (recA) harboring pOX38Gm. The resulting clones were mixed with E. coli HB101 (recA), and transconjugants were used to transfer pAT246 by plasmid conduction to E. coli K802N (rec+). Analysis of plasmid DNAs from the transconjugants of K802N by agarose gel electrophoresis and Southern hybridization indicated the presence of a transposon, designated Tn1528, in various sites of pOX38Gm. This 5.2-kb composite element consisted of aph(3')-VIa flanked by two direct copies of IS15-delta and transposed at a frequency of 4 x 10(-5). It therefore appears that IS15-delta, an insertion sequence widely spread in gram-negative bacteria, is likely responsible for dissemination to members of the family Enterobacteriaceae of aph(3')-VIa, a gene previously confined to Acinetobacter spp.
Collapse
Affiliation(s)
- T Lambert
- Centre d'Etudes Pharmaceutiques, Chatenay-Malabry, Paris, France
| | | | | |
Collapse
|
30
|
Lambert T, Gerbaud G, Galimand M, Courvalin P. Characterization of Acinetobacter haemolyticus aac(6')-Ig gene encoding an aminoglycoside 6'-N-acetyltransferase which modifies amikacin. Antimicrob Agents Chemother 1993; 37:2093-100. [PMID: 8257129 PMCID: PMC192234 DOI: 10.1128/aac.37.10.2093] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The amikacin resistance gene acc(6')-Ig of Acinetobacter haemolyticus BM2685 encoding an aminoglycoside 6'-N-acetyltransferase was characterized. The gene was identified as a coding sequence of 438 bp corresponding to a protein with a calculated mass of 16,522 Da. Analysis of the deduced amino acid sequence suggested that it was the fourth member of a subfamily of aminoglycoside 6'-N-acetyltransferases. The resistance gene was not transferable either by conjugation to Escherichia coli or to Acinetobacter baumannii or by transformation into Acinetobacter calcoaceticus. Plasmid DNA from strain BM2685 did not hybridize with an intragenic aac(6')-Ig probe. These results suggest a chromosomal location for this gene. The gene was detected by DNA hybridization in all 20 strains of A. haemolyticus tested but not in 179 other Acinetobacter strains, including A. baumannii, A. lwoffii, A. junii, and A. johnsonii and genospecies 3, 6, 11, 13, 14, 15, 16, and 17, of which 162 were amikacin resistant. The probe did not hybridize in dot blot assays with DNAs purified from members of the families Enterobacteriaceae and Pseudomonadaceae that encode 6'-N-acetyltransferases. These data suggest that the aac(6')-Ig gene is species specific and may be used to identify A. haemolyticus.
Collapse
Affiliation(s)
- T Lambert
- Centre d'Etudes Pharmaceutiques, Chatenay-Malabry, France
| | | | | | | |
Collapse
|
31
|
Struelens MJ, Carlier E, Maes N, Serruys E, Quint WG, van Belkum A. Nosocomial colonization and infection with multiresistant Acinetobacter baumannii: outbreak delineation using DNA macrorestriction analysis and PCR-fingerprinting. J Hosp Infect 1993; 25:15-32. [PMID: 7901273 DOI: 10.1016/0195-6701(93)90005-k] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The prevalence of nosocomial acinetobacter colonization and infection in a university hospital was reviewed and multiresistant Acinetobacter baumannii infections in an intensive care unit (ICU) were investigated using epidemiological typing and a case-control study. Acinetobacter colonization at various body sites was found in 3.2 to 10.8 per 1000 patients. Acinetobacter infection accounted for 0.3% of endemic nosocomial infections in critically ill patients and for 1% of nosocomial bacteraemia hospitalwide. Over a three-week period, four ventilated patients developed colonization, followed by pneumonia in two patients, with A. baumannii resistant to multiple antimicrobials. Cultures of samples from respiratory equipment and ICU surfaces (n = 27) as well as from hands of personnel (n = 14) failed to yield A. baumannii, except for one sample of respiratory tubing. Antibiogram, biotype, chromosomal DNA macrorestriction profiles and polymerase chain reaction (PCR) mediated fingerprints of A. baumannii isolates (n = 31) indicated that this outbreak was caused by two strains, one of which later spread to another hospital where it caused a second outbreak. Both strains were clearly discriminated from control strains from cases of sporadic infection. Risk factors for cross-colonization that were identified by a case-control comparison were neurosurgery, mechanical ventilation and treatment with broad-spectrum antibiotics. Transmission was controlled by implementing contact isolation precautions and routine sterilization of ventilator tubing. Wider use of sensitive genotypic methods like DNA macrorestriction analysis and PCR-mediated fingerprinting for typing nosocomial pathogens should improve the detection of micro-epidemics amenable to early control.
Collapse
Affiliation(s)
- M J Struelens
- Department of Microbiology, Hospital Epidemiology, Bruxelles, Belgium
| | | | | | | | | | | |
Collapse
|
32
|
Galimand M, Lambert T, Gerbaud G, Courvalin P. Characterization of the aac(6')-Ib gene encoding an aminoglycoside 6'-N-acetyltransferase in Pseudomonas aeruginosa BM2656. Antimicrob Agents Chemother 1993; 37:1456-62. [PMID: 8363376 PMCID: PMC187994 DOI: 10.1128/aac.37.7.1456] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Pseudomonas aeruginosa BM2656 was resistant to tobramycin and susceptible to gentamicin and amikacin by disk diffusion testing. This unusual resistance was not transferable by conjugation to Escherichia coli or P. aeruginosa PAO38, and plasmid DNA was not detected in this strain. A 0.9-kb fragment harboring the tobramycin resistance gene was cloned from BM2656 into pUC18, generating pAT129. Analysis for aminoglycoside-modifying activity in extracts of BM2656 and E. coli harboring pAT129 indicated that tobramycin resistance was due to synthesis of an aminoglycoside 6'-N-acetyltransferase type I [AAC(6')-I] enzyme which modified amikacin and tobramycin. Although amikacin was acetylated, the bactericidal synergism of this aminoglycoside with ceftazidime against BM2656 was minimally affected. The sequence of the DNA fragment was determined. It contained an aac (6')-Ib-like gene and was located downstream from a conserved region related to Tn21. The translated sequence of this aac(6')-Ib gene possessed 99.2% identity with the putative products of the aac(6')-Ib gene cassettes from Serratia marcescens and Klebsiella pneumoniae and 69% identity with the putative aacA(6')-II gene product from P. aeruginosa. We conclude that an aac(6')-Ib gene has spread to the chromosome of P. aeruginosa, probably by transposition.
Collapse
Affiliation(s)
- M Galimand
- Unité des Agents Antibactériens, Centre National de la Recherche Scientifique, Institut Pasteur, Paris, France
| | | | | | | |
Collapse
|
33
|
Seifert H, Baginski R, Schulze A, Pulverer G. Antimicrobial susceptibility of Acinetobacter species. Antimicrob Agents Chemother 1993; 37:750-3. [PMID: 8494371 PMCID: PMC187751 DOI: 10.1128/aac.37.4.750] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The in vitro activities of 16 antimicrobial agents against 180 Acinetobacter strains isolated from blood cultures (n = 162), central venous catheters (n = 11), and cerebrospinal fluids (n = 7) were studied. MICs were determined by a microtiter broth dilution method. Considerable differences in antimicrobial drug susceptibility against strains belonging to different species could be demonstrated. Acinetobacter baumannii isolates (n = 108) were generally more resistant than isolates identified as species other than A. baumannii. Multidrug resistance was common among A. baumannii isolates. Of the antimicrobial agents tested, imipenem was highly active against all A. baumannii isolates, and the other agents tested were only moderately active or inactive. Good activity against Acinetobacter species strain 3 was demonstrated for imipenem, amikacin, and ciprofloxacin. Most of the strains belonging to other species were susceptible to imipenem, ciprofloxacin, expanded-spectrum cephalosporins, amoxicillin-clavulanate, and the aminoglycosides but were resistant to ampicillin and older cephalosporins.
Collapse
Affiliation(s)
- H Seifert
- Institut für Medizinische Mikrobiologie und Hygiene, Universität Köln, Germany
| | | | | | | |
Collapse
|
34
|
Shaw KJ, Rather PN, Hare RS, Miller GH. Molecular genetics of aminoglycoside resistance genes and familial relationships of the aminoglycoside-modifying enzymes. Microbiol Rev 1993; 57:138-63. [PMID: 8385262 PMCID: PMC372903 DOI: 10.1128/mr.57.1.138-163.1993] [Citation(s) in RCA: 516] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The three classes of enzymes which inactivate aminoglycosides and lead to bacterial resistance are reviewed. DNA hybridization studies have shown that different genes can encode aminoglycoside-modifying enzymes with identical resistance profiles. Comparisons of the amino acid sequences of 49 aminoglycoside-modifying enzymes have revealed new insights into the evolution and relatedness of these proteins. A preliminary assessment of the amino acids which may be important in binding aminoglycosides was obtained from these data and from the results of mutational analysis of several of the genes encoding aminoglycoside-modifying enzymes. Recent studies have demonstrated that aminoglycoside resistance can emerge as a result of alterations in the regulation of normally quiescent cellular genes or as a result of acquiring genes which may have originated from aminoglycoside-producing organisms or from other resistant organisms. Dissemination of these genes is aided by a variety of genetic elements including integrons, transposons, and broad-host-range plasmids. As knowledge of the molecular structure of these enzymes increases, progress can be made in our understanding of how resistance to new aminoglycosides emerges.
Collapse
Affiliation(s)
- K J Shaw
- Schering-Plough Research Institute, Kenilworth, New Jersey 07033
| | | | | | | |
Collapse
|
35
|
Vila J, Marcos A, Marco F, Abdalla S, Vergara Y, Reig R, Gomez-Lus R, Jimenez de Anta T. In vitro antimicrobial production of beta-lactamases, aminoglycoside-modifying enzymes, and chloramphenicol acetyltransferase by and susceptibility of clinical isolates of Acinetobacter baumannii. Antimicrob Agents Chemother 1993; 37:138-41. [PMID: 8431011 PMCID: PMC187622 DOI: 10.1128/aac.37.1.138] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Antimicrobial susceptibility testing was performed on 54 epidemiologically unrelated clinical isolates of Acinetobacter baumannii by using a standard agar dilution technique. On the basis of the in vitro activities, imipenem and doxycycline were the most active agents, whereas amikacin, isepamicin, and the new fluorquinolones ciprofloxacin and ofloxacin presented moderate activity. Cephalosporinase activity was found in 98% of the strains, whereas lactamases of TEM type 1 and one with a pI of 7 to 7.5 were present in 16 and 11% of the strains, respectively. Resistance to aminoglycosides was explained by the production of the three classes of aminoglycoside-modifying enzymes, with predominance of aminoglycoside-3'-phosphotransferase VI in 28% of the strains.
Collapse
Affiliation(s)
- J Vila
- Department de Microbiologia, Facultat de Medicina, Hospital Clinic, Universitat de Barcelona, Spain
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Xirouchaki E, Giamarellou H. In vitro interactions of aminoglycosides with imipenem or ciprofloxacin against aminoglycoside resistant Acinetobacter baumannii. J Chemother 1992; 4:263-7. [PMID: 1479414 DOI: 10.1080/1120009x.1992.11739174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The in vitro interactions between gentamicin, tobramycin, netilmicin and amikacin with imipenem and ciprofloxacin were evaluated by the killing curve technique against 20 clinical isolates of Acinetobacter baumannii highly resistant to aminoglycosides which were susceptible or moderately susceptible to imipenem and resistant or moderately susceptible to ciprofloxacin. Imipenem enhanced killing by gentamicin, tobramycin, netilmicin and amikacin in tests with 9, 12, 10 and 15 strains (45-75%) while ciprofloxacin with 3, 7, 5 and 6 strains (15-35%) respectively. Interaction results were influenced by the height of aminoglycoside minimum bactericidal concentrations (MBCs) but were independent of imipenem or ciprofloxacin MBCs and the presence of aminoglycoside modifying enzymes. It is concluded that enhanced killing after aminoglycoside interaction with imipenem or ciprofloxacin versus A. baumannii cannot be predicted but it should be carefully tested in vitro. The in vivo significance of the reported findings mandates clinical studies in humans.
Collapse
Affiliation(s)
- E Xirouchaki
- First Department of Propedeutic Medicine, Laiko General Hospital, Athens University School of Medicine, Greece
| | | |
Collapse
|
37
|
Alvarez M, Mendoza MC. Epidemiological survey of genes encoding aminoglycoside phosphotransferases APH (3') I and APH (3') II using DNA probes. J Chemother 1992; 4:203-10. [PMID: 1328557 DOI: 10.1080/1120009x.1992.11739165] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The epidemiological survey of APH (3') I and APH (3') II genes, at a time when the specific antibiotic pressure was very low, was carried out by DNA-DNA hybridization. The sample included 334 aminoglycoside resistant Gram-negative bacteria collected from patients of a General Hospital. Of these, 251 hybridized with the APH (3') I-probe and 19 with the APH (3') II-probe but only 190 strains showed high resistance levels (CIM greater than 64 micrograms/ml) for kanamycin, neomycin and paromomycin. These strains were isolated both from inpatients and outpatients with different infectious diseases. The APH (3') I-gene was dispersed among all the bacterial species and clinical specimens tested but the APH (3') II-gene was not found in Pseudomonas spp, Escherichia coli, Citrobacter freundii and Enterobacter cloacae, nor in infected catheters. Several plasmids of different sizes carrying APH (3') genes were detected among different bacteria. Plasmids along with transposable elements (the probes used in this work were developed from Tn906 and Tn5) and the high consumption of other antibiotics whose resistance is carried by these bacteria might be playing an important role in the maintenance and dispersion of APH (3') genes.
Collapse
Affiliation(s)
- M Alvarez
- Facultad de Medicina, Departamento de Biología Funcional, Universidad de Oviedo, Spain
| | | |
Collapse
|
38
|
Kocabiyik S, Perlin MH. Site-specific mutations of conserved C-terminal residues in aminoglycoside 3'-phosphotransferase II: phenotypic and structural analysis of mutant enzymes. Biochem Biophys Res Commun 1992; 185:925-31. [PMID: 1320880 DOI: 10.1016/0006-291x(92)91715-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In order to test the biological importance of amino acids in the C-terminal quarter of aminoglycoside 3'-phosphotransferase II enzyme, seven of the highly conserved residues in this region, His-188, Asp-190, Asp-208, Gly-210, Arg-211, Asp-216 and Asp-220, were changed via site-directed mutagenesis. The phenotype of each mutant was compared to wildtype in terms of antibiotic susceptibilities and enzymatic activities. All of the substitutions either abolished or significantly reduced the resistance of the resulting strains to kanamycin, neomycin, butirosin, ribostamycin, paromomycin, gentamicin A, and G-418. Similarly, enzyme activities in crude extracts were substantially reduced for the mutant strains. Affinity of the enzyme for Mg+2-ATP decreased with His-188, Asp-190, Asp-216 and Asp-220 substitutions as revealed by Km measurements. Secondary structure analysis predicted that substitutions at the conserved residues caused severe conformational distortions at the corresponding regions of the protein.
Collapse
Affiliation(s)
- S Kocabiyik
- Department of Biology, University of Louisville, KY 40292
| | | |
Collapse
|
39
|
Kocabiyik S, Perlin MH. Altered substrate specificity by substitutions at Tyr218 in bacterial aminoglycoside 3â²-phosphotransferase-II. FEMS Microbiol Lett 1992. [DOI: 10.1111/j.1574-6968.1992.tb05090.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
40
|
Shaw KJ, Hare RS, Sabatelli FJ, Rizzo M, Cramer CA, Naples L, Kocsi S, Munayyer H, Mann P, Miller GH. Correlation between aminoglycoside resistance profiles and DNA hybridization of clinical isolates. Antimicrob Agents Chemother 1991; 35:2253-61. [PMID: 1803998 PMCID: PMC245368 DOI: 10.1128/aac.35.11.2253] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
DNA hybridization data and aminoglycoside resistance profiles (AGRPs) were determined for 4,088 clinical isolates from three studies (United States, Belgium, and Argentina). The correlation between susceptibility profiles and hybridization results was determined with nine DNA probes. For each of the seven aminoglycoside resistance profiles which we were able to test, the data suggested at least two distinct genes could encode enzymes which lead to identical resistance profiles. Furthermore, the DNA hybridization data showed that individual strains carried up to six unique aminoglycoside resistance genes. DNA hybridization revealed interesting differences in the frequencies of these genes by organism and by country.
Collapse
Affiliation(s)
- K J Shaw
- Schering-Plough Research, Bloomfield, New Jersey 07003
| | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Hopkins JD, Flores A, del Pilar Pla M, Lester S, O'Brien TF. Nosocomial spread of an amikacin resistance gene on both a mobilized, nonconjugative plasmid and a conjugative plasmid. Antimicrob Agents Chemother 1991; 35:1605-11. [PMID: 1656868 PMCID: PMC245227 DOI: 10.1128/aac.35.8.1605] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Resistance to amikacin among members of the family Enterobacteriaceae at a hospital in Venezuela rose from 2% in 1979 to 5% in 1984 and 10% in 1985 as amikacin usage rose 20-fold to exceed gentamicin usage. Resistance to gentamicin remained at 25 to 27%. We examined the plasmids from 21 isolates obtained in 1984 and 1985. Nine of eleven in 1984 and three of ten in 1985 carried aacA and sul on a 3.8-kb BamHI fragment of pBWH300, a 10.4-kb nonconjugative plasmid that had been mobilized into strains of six species by at least two different coresident conjugative plasmids. Six 1985 isolates of two species carried these genes on a similar BamHI fragment of the 104-kb conjugative plasmid pBWH303. One isolate in 1984 and one in 1985 carried the 69-kb conjugative plasmid pBWH301, which had aacA as the promoter-proximal gene of an operon that also encompassed the cat and aadB resistance genes. Another conjugative plasmid, pBWH302, was found in a single isolate. It carried a different aacA allele on the functional transposon Tn654, which appeared to be closely related to Tn1331, a transposon previously isolated in Argentina and Chile. Increased selection may thus have led to dissemination of an endemic aacA allele on two endemic plasmids, one spread by mobilization, with occasional intrusion of additional aacA alleles from outside.
Collapse
Affiliation(s)
- J D Hopkins
- Department of Medical Microbiology & Immunology, School of Medicine, University of California, Davis 95616
| | | | | | | | | |
Collapse
|
42
|
Gay Elisha B, Steyn LM. Cloning of AAC(3) and AAD(2″) genes fromAcinetobacter: differential expression in the host strain. Curr Microbiol 1991. [DOI: 10.1007/bf02092319] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
43
|
Terán FJ, Suárez JE, Mendoza MC. Cloning, sequencing, and use as a molecular probe of a gene encoding an aminoglycoside 6'-N-acetyltransferase of broad substrate profile. Antimicrob Agents Chemother 1991; 35:714-9. [PMID: 2069376 PMCID: PMC245084 DOI: 10.1128/aac.35.4.714] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A gene coding for an aminoglycoside 6'-N-acetyltransferase that was able to modify amikacin was cloned from a plasmid isolated from a clinical strain of Enterobacter cloacae. Sequencing of a 955-bp segment which mediates the modifying activity revealed a single open reading frame of 432 nucleotides that predicted a polypeptide of 144 amino acid residues with a molecular weight of 16,021. Putative ribosomal binding sites and -10 and -35 sequences were located at the 5' end of the gene. The size of the polypeptide was confirmed through minicell analysis of the expression products of plasmids containing the sequence. The use of the gene as a molecular probe revealed its specificity toward strains harboring genes coding for related enzymes. This probe is therefore useful for epidemiological studies.
Collapse
Affiliation(s)
- F J Terán
- Departamento de Biología Funcional, Universidad de Oviedo, Spain
| | | | | |
Collapse
|
44
|
Elisha BG, Steyn LM. Identification of an Acinetobacter baumannii gene region with sequence and organizational similarity to Tn2670. Plasmid 1991; 25:96-104. [PMID: 1650008 DOI: 10.1016/0147-619x(91)90020-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A chloramphenicol resistance gene was cloned from chromosomal DNA prepared from a clinical Acinetobacter baumannii isolate. Sequence analysis of this gene (cat) and the flanking DNA regions shows that this gene is linked to Tn21 and to IS1 in a manner similar to that found in Tn2670.
Collapse
Affiliation(s)
- B G Elisha
- Department of Medical Microbiology, University of Cape Town Medical School, South Africa
| | | |
Collapse
|
45
|
Affiliation(s)
- G A Jacoby
- Infectious Disease Unit, Massachusetts General Hospital, Boston 02114
| | | |
Collapse
|
46
|
Jacoby GA, Blaser MJ, Santanam P, Hächler H, Kayser FH, Hare RS, Miller GH. Appearance of amikacin and tobramycin resistance due to 4'-aminoglycoside nucleotidyltransferase [ANT(4')-II] in gram-negative pathogens. Antimicrob Agents Chemother 1990; 34:2381-6. [PMID: 1965106 PMCID: PMC172065 DOI: 10.1128/aac.34.12.2381] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Following the use of amikacin as the principal aminoglycoside at a Denver hospital, amikacin resistance appeared first in Pseudomonas aeruginosa and then in Escherichia coli, Klebsiella pneumoniae, and other enteric organisms from debilitated and compromised patients who had spent time in intensive care units and who had been treated with multiple antibiotics, usually including amikacin. In a P. aeruginosa isolate, resistance to amikacin and tobramycin was transferable by the IncP-2 plasmid pMG77, while in E. coli and K. pneumoniae resistance was carried by the transmissible plasmids pMG220, pMG221, and pMG222 belonging to the IncM group. Isolates and transconjugants produced an enzyme with adenyltransferase activity with substrates having a 4'-hydroxyl group, such as amikacin, kanamycin, neomycin, Sch 21768, isepamicin (Sch 21420), or tobramycin, but not with aminoglycosides lacking this target, such as dibekacin, netilmicin, sisomicin, or gentamicin C components. Genes encoding the 4'-aminoglycoside nucleotidyltransferase [ANT(4')] activity were cloned from pMG77, pMG221, and pMG222. A DNA probe prepared from the ANT(4') found in P. aeruginosa hybridized with the ANT(4') determinant found in E. coli. A probe for the ANT(4') from Staphylococcal spp., which differs in its modification of substrates, like dibekacin, that have a 4"- but not a 4'-hydroxyl group, failed to hybridize with the gram-negative ANT(4') determinant, which consequently has been termed ANT(4')-II.
Collapse
Affiliation(s)
- G A Jacoby
- Massachusetts General Hospital, Boston 02114
| | | | | | | | | | | | | |
Collapse
|
47
|
Joly-Guillou ML, Bergogne-Berezin E, Vieu JF. A study of the relationships between antibiotic resistance phenotypes, phage-typing and biotyping of 117 clinical isolates of Acinetobacter spp. J Hosp Infect 1990; 16:49-58. [PMID: 1974906 DOI: 10.1016/0195-6701(90)90048-s] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Two typing systems were used to conduct an epidemiological study of Acinetobacter and to establish their relationship to antibiotic resistance phenotypes. Biotyping was performed with biochemical tests according to the new definition of Acinetobacter baumannii (18 biotypes). Phage typing included two complementary systems: 125 phage-types and 25 subtypes. Resistance phenotype analysis included 11 antibiotics. The results of the study showed that: (1) nine phage-types or subtypes (67%) and two groups of atypical phage-types (5%) or of untypable strains (28%), could be defined; (2) all strains that were resistant to carboxy/ureido-penicillins and cephalosporins (62%) belonged to biotypes 6 or 9; among them 70% belonged to phage-types 17 or 124; (3) imipenem resistance was observed in five isolates of biotype 9 and one of biotype 6; (4) a phenotype including resistance to third generation cephalosporins (but not carboxypenicillins) and to amikacin (but not tobramycin) represented 8.5% of the isolates; 90% of them belonged to biotype 1 and were not phage-typable; (5) 15% of the isolates were not identified as A. baumannii; among them five Acinetobacter haemolyticus strains all had the same resistance phenotype: amikacin-tobramycin-kanamycin-netilmicin resistant; they were however, susceptible to beta-lactams and to gentamicin. There was a clear relationship between biotypes 6 and 9 and phage-types 17 and 124 which were the strains most resistant to beta-lactams and aminoglycosides and were predominant in the survey. The three typing systems were complementary but it seems that antibiotic resistance phenotypes and one of the two other typing systems would be required in parallel to provide suitable information for epidemiological purposes.
Collapse
|
48
|
Lambert T, Gerbaud G, Bouvet P, Vieu JF, Courvalin P. Dissemination of amikacin resistance gene aphA6 in Acinetobacter spp. Antimicrob Agents Chemother 1990; 34:1244-8. [PMID: 2168146 PMCID: PMC171792 DOI: 10.1128/aac.34.6.1244] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The distribution of the aphA6 gene, encoding a 3'-aminoglycoside phosphotransferase type VI, was studied by dot blot hybridization with 115 amikacin-resistant Acinetobacter strains from various geographical areas. Nucleotide sequences related to aphA6 were found in 109 strains belonging to seven species. As inferred from results of Southern hybridization, dissemination of amikacin resistance in Acinetobacter spp. is due to a gene rather than a strain or plasmid epidemic.
Collapse
Affiliation(s)
- T Lambert
- Unité des Agents Antibactériens, Institut Pasteur, Paris, France
| | | | | | | | | |
Collapse
|
49
|
Vliegenthart JS, Ketelaar-van Gaalen PA, van de Klundert JA. Nucleotide sequence of the aacC2 gene, a gentamicin resistance determinant involved in a hospital epidemic of multiply resistant members of the family Enterobacteriaceae. Antimicrob Agents Chemother 1989; 33:1153-9. [PMID: 2552900 PMCID: PMC172616 DOI: 10.1128/aac.33.8.1153] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A gentamicin resistance determinant of a conjugative plasmid from Enterobacter cloacae was cloned on a 3.2-kilobase fragment in the PstI site of pBR322. Substrate profiles for eight aminoglycosides at three concentrations showed that the resistance was due to aminoglycoside-(3)-N-acetyltransferase isoenzyme II. Insertion mapping by the gamma-delta transposon revealed that the size of the gene was approximately 1 kilobase. Nucleotide sequencing of the aacC2 gene identified an open reading frame of 858 base pairs, preceded by a promoter and a ribosome-binding site. From these data the molecular mass of the protein was calculated to be 30.6 kilodaltons. A comparison of the nucleotide sequence of the aacC2 gene with those published for the aacC3 and aacC4 genes showed complete homology of the aacC2 gene and the presumed aacC3 gene. An internal restriction fragment of the gene used as a probe in colony hybridization demonstrated the presence of the aacC2 gene in 86% of 86 multiply resistant isolates of the family Enterobacteriaceae obtained during an 18-month hospital epidemic. This corroborates our earlier data on the enzyme identification by the susceptibility profiling method.
Collapse
Affiliation(s)
- J S Vliegenthart
- Department of Medical Microbiology, University Hospital, Leiden, The Netherlands
| | | | | |
Collapse
|
50
|
Taylor DE, Yan W, Ng LK, Manavathu EK, Courvalin P. Genetic characterization of kanamycin resistance in Campylobacter coli. ANNALES DE L'INSTITUT PASTEUR. MICROBIOLOGY 1988; 139:665-76. [PMID: 2855308 DOI: 10.1016/0769-2609(88)90071-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The restriction map of plasmid pIP1433 from Campylobacter coli BM2509, isolated in France, was constructed and the location of the kanamycin (Km) and tetracycline (Tc) resistance markers determined using probes for aphA-3 and tetO genes, respectively. These DNA probes were used to study a second Km- and Tc-resistant strain C. coli UA696, isolated in Canada. In this strain, the Km resistance determinant was located in the chromosome. Like pIP1433, the Km resistance determinant in C. coli UA696 specified a 3'-aminoglycoside phosphotransferase of type III whereas the tetO gene was located on a non-transmissible plasmid.
Collapse
Affiliation(s)
- D E Taylor
- Department of Microbiology, University of Alberta, Edmonton, Canada
| | | | | | | | | |
Collapse
|