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Ranta K, Skurnik M, Kiljunen S. fENko-Kae01 is a flagellum-specific jumbo phage infecting Klebsiella aerogenes. BMC Microbiol 2024; 24:234. [PMID: 38951769 PMCID: PMC11218385 DOI: 10.1186/s12866-024-03387-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 06/19/2024] [Indexed: 07/03/2024] Open
Abstract
BACKGROUND Klebsiella aerogenes is an opportunistic pathogen that causes a wide variety of infections. Due to the rising problem of antibiotic resistance, novel antibiotics and strategies to combat bacterial infections are needed. Host-specific bacteriophages are natural enemies of bacteria and can be used in phage therapy as an alternative form of treatment against bacterial infections. Jumbo phages are defined as phages with genomes larger than 200 kb. Relatively few studies have been done on jumbo phages compared to smaller phages. RESULTS A novel phage, fENko-Kae01, was isolated from a commercial phage cocktail. Genomic analysis revealed that fENko-Kae01 is a lytic jumbo phage with a 360 kb genome encoding 578 predicted genes. No highly similar phage genomes were identified and fENko-Kae01 may be a completely new genus representative. No known genes associated with lysogenic life cycle, bacterial virulence, or antibiotic resistance were identified. The phage had myovirus morphology and a narrow host range. Phage resistant bacterial mutants emerged under phage selection. Whole genome sequencing revealed that the biogenesis of the flagellum was affected in four mutants and the lack of functional flagellum was confirmed in motility assays. Furthermore, phage fENKo-Kae01 failed to adsorb on the non-motile mutants indicating that the bacterial flagellum is the phage-binding receptor. CONCLUSIONS fENko-Kae01 is a novel jumbo bacteriophage that is considered safe for phage therapy. fENko-Kae01 uses the flagellum as the phage-binding receptor and may represent a completely novel genus.
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Affiliation(s)
- Kira Ranta
- HUS Diagnostic Center, Clinical Microbiology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Human Microbiome Research Program, Research Program Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Mikael Skurnik
- Human Microbiome Research Program, Research Program Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Saija Kiljunen
- Human Microbiome Research Program, Research Program Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
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Molecular characterization of Enterobacter aerogenes isolated from urinary tract infections in Iran. Acta Trop 2022; 232:106485. [PMID: 35487296 DOI: 10.1016/j.actatropica.2022.106485] [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: 01/05/2022] [Revised: 04/20/2022] [Accepted: 04/24/2022] [Indexed: 11/24/2022]
Abstract
The prevalence of multidrug-resistant Enterobacter aerogenes strains in UTIs is increasing. Therefore, the purpose of this study was to examine the mechanisms of resistance in Enterobacter aerogenes strains isolated from the urinary tract of infected patients. To achieve this goal, 786 urine samples from Shahrekord, Iran, were collected from June 2019 to February 2020. After isolating and identifying E. aerogenes samples, antibiotic susceptibility testing was done on the strains using Kirby-Bauer's disk diffusion method. The biofilm formation assays were performed to study the link between antibiotic resistance and biofilm formation and virulence genes. As a result, amongst the 786 urine samples, 50 strains were identified as E. aerogenes. The lowest rate of resistance was observed with imipenem (30%). This study also reports that all the strains of E. aerogenes are biofilm producers, with 50% of isolates producing a large amount, 30% a moderate amount, and 20% a small amount of biofilm. 42% were identified in the phenotypic study of ESBLs. In the PCR test, (64%) produced broad-spectrum beta-lactamases. Prevalence of qnrC, qnrB, qnrA, tetA, tet B, acc(3)IIa, acc(2)IIa, ant(2)Ia and Sul1 in strong producing isolates reported 100%, 80.95%,% 58.14, 87.5%, 81.58%, 86.67%, 82.14, 81.48% and 90% respectively. In the statistical analysis based on the chi-square test, a statistically significant relationship was reported between qnrA, qnrB, tetA, tetB, Sul1, ant(2)Ia, ant(3)I, aac(3)II, and biofilm formation. Resistance to cephalothin, ceftriaxone, cefotaxime and ceftazidime were reported 40%, 34%, 30% and 30%, respectively. Out of 50 Enterobacter aerogenes, 32 isolates (64%) were identified in the phenotypic study of ESBLS, prevalence of blaCTX-M, blaTEM and blaSHV reported 30%, 20% and 14% respectively. There is a significant relationship between resistance to ceftriaxone and blaCTX-M. Prevalence of csgA, ybtS, markD, rmpA, csgD and fimH in strong biofilm formation isolates reported 84%, 83.33%, 80%, 80%, 80% and 66% respectively. The chi-square test showed a statistically significant relationship between biofilm production and resistance genes fimH, csgA, csgD, ybtS, and mrkD. The findings of this study indicate that the ability to produce biofilms is associated with the increase of antibiotic resistance and virulence genes. These agents enable bacteria to produce biofilms that ultimately lead to colonization and bacterial survival in the body.
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D'Souza R, Nguyen LP, Pinto NA, Lee H, Vu TN, Kim H, Cho HS, Yong D. Role of AmpG in the resistance to β-lactam agents, including cephalosporins and carbapenems: candidate for a novel antimicrobial target. Ann Clin Microbiol Antimicrob 2021; 20:45. [PMID: 34134705 PMCID: PMC8207665 DOI: 10.1186/s12941-021-00446-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 05/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A complex cascade of genes, enzymes, and transcription factors regulates AmpC β-lactamase overexpression. We investigated the network of AmpC β-lactamase overexpression in Klebsiella aerogenes and identified the role of AmpG in resistance to β-lactam agents, including cephalosporins and carbapenems. METHODS A transposon mutant library was created for carbapenem-resistant K. aerogenes YMC2008-M09-943034 (KE-Y1) to screen for candidates with increased susceptibility to carbapenems, which identified the susceptible mutant derivatives KE-Y3 and KE-Y6. All the strains were subjected to highly contiguous de novo assemblies using PacBio sequencing to investigate the loss of resistance due to transposon insertion. Complementation and knock-out experiments using lambda Red-mediated homologous recombinase and CRISPR-Cas9 were performed to confirm the role of gene of interest. RESULTS In-depth analysis of KE-Y3 and KE-Y6 revealed the insertion of a transposon at six positions in each strain, at which truncation of the AmpG permease gene was common in both. The disruption of the AmpG permease leads to carbapenem susceptibility, which was further confirmed by complementation. We generated an AmpG permease gene knockout using lambda Red-mediated recombineering in K. aerogenes KE-Y1 and a CRISPR-Cas9-mediated gene knockout in multidrug-resistant Klebsiella pneumoniae-YMC/2013/D to confer carbapenem susceptibility. CONCLUSIONS These findings suggest that inhibition of the AmpG is a potential strategy to increase the efficacy of β-lactam agents against Klebsiella aerogenes.
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Affiliation(s)
- Roshan D'Souza
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea.,J. Craig Venter Institute, Rockville, MD, USA
| | - Le Phuong Nguyen
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea.,Brain Korea 21+ Project for Medical Science, Yonsei University, Seoul, Korea
| | - Naina A Pinto
- Brain Korea 21+ Project for Medical Science, Yonsei University, Seoul, Korea
| | - Hyunsook Lee
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea.,Brain Korea 21+ Project for Medical Science, Yonsei University, Seoul, Korea
| | - Thao Nguyen Vu
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea.,Brain Korea 21+ Project for Medical Science, Yonsei University, Seoul, Korea
| | - Hoyoung Kim
- Department of Systems Biology, Yonsei University, Seoul, Korea
| | - Hyun Soo Cho
- Department of Systems Biology, Yonsei University, Seoul, Korea
| | - Dongeun Yong
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Korea.
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Chakkyarath V, Shanmugam A, Natarajan J. Prioritization of potential drug targets and antigenic vaccine candidates against Klebsiella aerogenes using the computational subtractive proteome-driven approach. JOURNAL OF PROTEINS AND PROTEOMICS 2021; 12:201-211. [PMID: 34305354 PMCID: PMC8284688 DOI: 10.1007/s42485-021-00068-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/14/2021] [Accepted: 07/05/2021] [Indexed: 02/07/2023]
Abstract
Klebsiella aerogenes is a multidrug-resistant Gram-negative bacterium that causes nosocomial infections. The organism showed resistance to most of the conventional antibiotics available. Because of the high resistance of the species, the treatment of K. aerogenes is difficult. These species are resistant to third-generation cephalosporins due to the production of chromosomal beta-lactams with cephalosporin activity. The lack of better treatment and the development of therapeutic resistance in hospitals hinders better/new broad-spectrum-based treatment against this pathogen. This study identifies potential drug targets/vaccine candidates through a computational subtractive proteome-driven approach. This method is used to predict proteins that are not homologous to humans and human symbiotic intestinal flora. The resultant proteome of K. aerogenes was further searched for proteins, which are essential, virulent, and determinants of antibiotic/drug resistance. Subsequently, their druggability properties were also studied. The data set was reduced based on its presence in the pathogen-specific metabolic pathways. The subtractive proteome analysis predicted 13 proteins as potential drug targets for K. aerogenes. Furthermore, these target proteins were annotated based on their spectrum of activity, cellular localization, and antigenicity properties, which ensured that they are potent candidates for broad-spectrum antibiotic and vaccine design. The results open up new opportunities for designing and manufacturing powerful antigenic vaccines against K. aerogenes and the detection and release of new and active drugs against K. aerogenes without altering the gut microbiome. Supplementary Information The online version contains supplementary material available at 10.1007/s42485-021-00068-9.
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Affiliation(s)
- Vijina Chakkyarath
- grid.411677.20000 0000 8735 2850Data Mining and Text Mining Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, 641046 India
| | - Anusuya Shanmugam
- grid.444708.b0000 0004 1799 6895Department of Pharmaceutical Engineering, Vinayaka Mission’s Kirupananda Variyar Engineering College, Vinayaka Mission’s Research Foundation (Deemed to be University), Salem, Tamil Nadu 636308 India
| | - Jeyakumar Natarajan
- grid.411677.20000 0000 8735 2850Data Mining and Text Mining Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, 641046 India
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Davin-Regli A, Lavigne JP, Pagès JM. Enterobacter spp.: Update on Taxonomy, Clinical Aspects, and Emerging Antimicrobial Resistance. Clin Microbiol Rev 2019; 32:e00002-19. [PMID: 31315895 PMCID: PMC6750132 DOI: 10.1128/cmr.00002-19] [Citation(s) in RCA: 250] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The genus Enterobacter is a member of the ESKAPE group, which contains the major resistant bacterial pathogens. First described in 1960, this group member has proven to be more complex as a result of the exponential evolution of phenotypic and genotypic methods. Today, 22 species belong to the Enterobacter genus. These species are described in the environment and have been reported as opportunistic pathogens in plants, animals, and humans. The pathogenicity/virulence of this bacterium remains rather unclear due to the limited amount of work performed to date in this field. In contrast, its resistance against antibacterial agents has been extensively studied. In the face of antibiotic treatment, it is able to manage different mechanisms of resistance via various local and global regulator genes and the modulation of the expression of different proteins, including enzymes (β-lactamases, etc.) or membrane transporters, such as porins and efflux pumps. During various hospital outbreaks, the Enterobacter aerogenes and E. cloacae complex exhibited a multidrug-resistant phenotype, which has stimulated questions about the role of cascade regulation in the emergence of these well-adapted clones.
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Affiliation(s)
- Anne Davin-Regli
- INSERM, SSA, IRBA, MCT, Aix Marseille University, Marseille, France
| | - Jean-Philippe Lavigne
- Department of Microbiology, U1047, INSERM, University Montpellier and University Hospital Nîmes, Nîmes, France
| | - Jean-Marie Pagès
- INSERM, SSA, IRBA, MCT, Aix Marseille University, Marseille, France
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Matinyi S, Enoch M, Akia D, Byaruhanga V, Masereka E, Ekeu I, Atuheire C. Contamination of microbial pathogens and their antimicrobial pattern in operating theatres of peri-urban eastern Uganda: a cross-sectional study. BMC Infect Dis 2018; 18:460. [PMID: 30200891 PMCID: PMC6131813 DOI: 10.1186/s12879-018-3374-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/04/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Microbial contamination of hospital environment, especially in operating theatres (OT) and other specialized units has greatly contributed to continuous and multiple exposure to nosocomial infections by patients and the public. We purposed to assess microbial contamination of operating theatres and antibacterial sensitivity pattern of bacteria isolated from theatres of Mbale Regional Referral Hospital, Eastern Uganda. METHODS We employed a laboratory based cross-sectional study design. Swabbing of different surfaces and settle plate establishment in 4 various operating theatres was carried out. A total of 109 samples were collected, 31 air samples and 78 swabs from four operating theatres. Samples were collected in the mornings after disinfection prior to start of daily operations. Antibacterial sensitivity testing of isolated bacterial pathogens was performed by Kirby Bauer disc diffusion method following standard operating procedure. Colony counts for the settle plates were carried out using a colony counter. RESULTS All the four theatres had their mean colony counts exceeding the acceptable limit of 5 cfu/dm2/h. Gynaecology theatre had up to 261 cfu/dm2/h and Ophthalmology operating theatre had approximately 43 cfu/dm2/h. A total of 14 different organisms were isolated with Pseudomonas spp. [23.9%]; Bacillus spp. [17.5%] and Aspergillus spp. [15.8%] being the most common contaminants respectively. Other isolates included Enterococcus spp., Rhizopus spp. and Coagulate Negative Staphylococcus isolates especially from settle plates. Most bacterial isolates showed considerable resistance to antibacterial agents. Pseudomonas spp. was resistant to chloramphenicol (53.6%) and cotrimoxazole (57.1%). Most of the bacterial pathogens were sensitive to imipenem [83.3%]. CONCLUSIONS There is moderate contamination of operating theatres of Mbale Regional Referral Hospital. Common organisms were Pseudomonas, Bacillus, and Aspergillus spps. Resistance was observed against chloramphenicol and cotrimoxazole. More caution is necessary to carefully disinfect the operating theatres at Regional referral settings and similar tertiary health care centres with more emphasis on obstetrics and gynecology theatres. Diagnosis and care of patients at such clinical settings should consider the possibility of antibiotic resistance.
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Affiliation(s)
- Sandra Matinyi
- Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara of Science and Technology, (MUST), Mbarara, Uganda
| | - Muwanguzi Enoch
- Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara of Science and Technology, (MUST), Mbarara, Uganda
| | - Deborah Akia
- Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara of Science and Technology, (MUST), Mbarara, Uganda
| | - Valentine Byaruhanga
- Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara of Science and Technology, (MUST), Mbarara, Uganda
| | - Edson Masereka
- Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara of Science and Technology, (MUST), Mbarara, Uganda
| | - Isaac Ekeu
- Department of Medical Laboratory Sciences, Faculty of Medicine, Mbarara of Science and Technology, (MUST), Mbarara, Uganda
| | - Collins Atuheire
- Department of Biosecurity, Ecosystems and Veterinary Public Health, College of Veterinary Medicine, Animal Resources & Biosecurity, Makerere University, Kampala, P.O Box 7076, Uganda
- Department of Public Health, School of Allied Health Sciences, Kampala International University, Western Campus, Bushenyi, Uganda
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Bedenić B, Vranić-Ladavac M, Venditti C, Tambić-Andrašević A, Barišić N, Gužvinec M, Karčić N, Petrosillo N, Ladavac R, di Caro A. Emergence of colistin resistance in Enterobacter aerogenes from Croatia. J Chemother 2017; 30:120-123. [PMID: 29063811 DOI: 10.1080/1120009x.2017.1382121] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A colistin-resistant Enterobacter aerogenes [study code 12264] was isolated from the tracheal aspirate of a 71-year-old male patient in the General Hospital [GH] in Pula, Croatia. The patient was previously treated in University Hospital Centre in Rijeka with colistin in order to eradicate Acinetobacter baumannii isolate, susceptible only to colistin and tigecycline. Genes encoding ESBLs [blaTEM, blaSHV, blaCTX-M, blaPER-1] were screened by PCR. The strain was shown to possess blaCTX-M-15 and blaTEM-1 genes. To asses genes possibly involved in resistance to colistin the chromosomal enconding mgrB gene and the plasmid-mediated mcr-1 and mcr-2 genes were screened as described previously. Mcr-1 and mcr-2 genes were not detected and mgrB gene presented a wild-type sequence. PCR-based Replicon typing method [PBRT] conducted on an E. aerogenes isolate, showed that the strain carried an IncN plasmid. Adaptive mechanisms such as changes of the bacterial cell outer membrane that cause porin decrease or presence of an efflux pump, due to selection pressure exerted by the therapeutic administration of colistin, could be responsible for the development of colistin resistance in our strain, as recently reported in E. aerogenes from France. Due to effective infection control measures, the colistin-resistant strain did not spread to other patients or hospital wards. This is the first report of an ESBL-producing, colistin-resistant E. aerogenes in clinically relevant samples such as endotracheal aspirate and blood culture, showing the presence of this rare resistance profile among Gram-negative bacteria.
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Affiliation(s)
- Branka Bedenić
- a Department of Microbiology, School of Medicine , University of Zagreb , Zagreb , Croatia.,b Clinical Department of Clinical and Molecular Microbiology , University Hospital Center Zagreb , Zagreb , Croatia
| | | | - Carolina Venditti
- d National Institute for Infectious Diseases, Spallanzani , Rome , Italy
| | | | - Nada Barišić
- c Public Health Institute of Istria County , Pula , Croatia
| | - Marija Gužvinec
- e University Hospital for Infectious Diseases , Zagreb , Croatia
| | - Natalie Karčić
- c Public Health Institute of Istria County , Pula , Croatia
| | - Nicola Petrosillo
- d National Institute for Infectious Diseases, Spallanzani , Rome , Italy
| | | | - Antonino di Caro
- d National Institute for Infectious Diseases, Spallanzani , Rome , Italy
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Liakopoulos A, Mevius D, Ceccarelli D. A Review of SHV Extended-Spectrum β-Lactamases: Neglected Yet Ubiquitous. Front Microbiol 2016; 7:1374. [PMID: 27656166 PMCID: PMC5011133 DOI: 10.3389/fmicb.2016.01374] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 08/19/2016] [Indexed: 12/29/2022] Open
Abstract
β-lactamases are the primary cause of resistance to β-lactams among members of the family Enterobacteriaceae. SHV enzymes have emerged in Enterobacteriaceae causing infections in health care in the last decades of the Twentieth century, and they are now observed in isolates in different epidemiological settings both in human, animal and the environment. Likely originated from a chromosomal penicillinase of Klebsiella pneumoniae, SHV β-lactamases currently encompass a large number of allelic variants including extended-spectrum β-lactamases (ESBL), non-ESBL and several not classified variants. SHV enzymes have evolved from a narrow- to an extended-spectrum of hydrolyzing activity, including monobactams and carbapenems, as a result of amino acid changes that altered the configuration around the active site of the β -lactamases. SHV-ESBLs are usually encoded by self-transmissible plasmids that frequently carry resistance genes to other drug classes and have become widespread throughout the world in several Enterobacteriaceae, emphasizing their clinical significance.
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Affiliation(s)
- Apostolos Liakopoulos
- Department of Bacteriology and Epidemiology, Central Veterinary Institute of Wageningen UR Lelystad, Netherlands
| | - Dik Mevius
- Department of Bacteriology and Epidemiology, Central Veterinary Institute of Wageningen URLelystad, Netherlands; Faculty of Veterinary Medicine, Utrecht UniversityUtrecht, Netherlands
| | - Daniela Ceccarelli
- Department of Bacteriology and Epidemiology, Central Veterinary Institute of Wageningen UR Lelystad, Netherlands
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Hicks RP. Antibacterial and anticancer activity of a series of novel peptides incorporating cyclic tetra-substituted Cα amino acids. Bioorg Med Chem 2016; 24:4056-4065. [DOI: 10.1016/j.bmc.2016.06.048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/20/2016] [Accepted: 06/23/2016] [Indexed: 11/26/2022]
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Pitout JD, Chan WW, Church DL. Tackling antimicrobial resistance in lower urinary tract infections: treatment options. Expert Rev Anti Infect Ther 2016; 14:621-32. [DOI: 10.1080/14787210.2016.1188004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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In Vivo Evolution of Bacterial Resistance in Two Cases of Enterobacter aerogenes Infections during Treatment with Imipenem. PLoS One 2015; 10:e0138828. [PMID: 26398358 PMCID: PMC4580588 DOI: 10.1371/journal.pone.0138828] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 09/03/2015] [Indexed: 11/24/2022] Open
Abstract
Infections caused by multidrug resistant (MDR) bacteria are a major concern worldwide. Changes in membrane permeability, including decreased influx and/or increased efflux of antibiotics, are known as key contributors of bacterial MDR. Therefore, it is of critical importance to understand molecular mechanisms that link membrane permeability to MDR in order to design new antimicrobial strategies. In this work, we describe genotype-phenotype correlations in Enterobacter aerogenes, a clinically problematic and antibiotic resistant bacterium. To do this, series of clinical isolates have been periodically collected from two patients during chemotherapy with imipenem. The isolates exhibited different levels of resistance towards multiple classes of antibiotics, consistently with the presence or the absence of porins and efflux pumps. Transport assays were used to characterize membrane permeability defects. Simultaneous genome-wide analysis allowed the identification of putative mutations responsible for MDR. The genome of the imipenem-susceptible isolate G7 was sequenced to closure and used as a reference for comparative genomics. This approach uncovered several loci that were specifically mutated in MDR isolates and whose products are known to control membrane permeability. These were omp35 and omp36, encoding the two major porins; rob, encoding a global AraC-type transcriptional activator; cpxA, phoQ and pmrB, encoding sensor kinases of the CpxRA, PhoPQ and PmrAB two-component regulatory systems, respectively. This report provides a comprehensive analysis of membrane alterations relative to mutational steps in the evolution of MDR of a recognized nosocomial pathogen.
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Davin-Regli A, Pagès JM. Enterobacter aerogenes and Enterobacter cloacae; versatile bacterial pathogens confronting antibiotic treatment. Front Microbiol 2015; 6:392. [PMID: 26042091 PMCID: PMC4435039 DOI: 10.3389/fmicb.2015.00392] [Citation(s) in RCA: 300] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/16/2015] [Indexed: 12/14/2022] Open
Abstract
Enterobacter aerogenes and E. cloacae have been reported as important opportunistic and multiresistant bacterial pathogens for humans during the last three decades in hospital wards. These Gram-negative bacteria have been largely described during several outbreaks of hospital-acquired infections in Europe and particularly in France. The dissemination of Enterobacter sp. is associated with the presence of redundant regulatory cascades that efficiently control the membrane permeability ensuring the bacterial protection and the expression of detoxifying enzymes involved in antibiotic degradation/inactivation. In addition, these bacterial species are able to acquire numerous genetic mobile elements that strongly contribute to antibiotic resistance. Moreover, this particular fitness help them to colonize several environments and hosts and rapidly and efficiently adapt their metabolism and physiology to external conditions and environmental stresses. Enterobacter is a versatile bacterium able to promptly respond to the antibiotic treatment in the colonized patient. The balance of the prevalence, E. aerogenes versus E. cloacae, in the reported hospital infections during the last period, questions about the horizontal transmission of mobile elements containing antibiotic resistance genes, e.g., the efficacy of the exchange of resistance genes Klebsiella pneumoniae to Enterobacter sp. It is also important to mention the possible role of antibiotic use in the treatment of bacterial infectious diseases in this E. aerogenes/E. cloacae evolution.
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Affiliation(s)
- Anne Davin-Regli
- Transporteurs Membranaires, Chimiorésistance et Drug Design, Facultés de Médecine et Pharmacie, UMR-MD1, IRBA - Aix-Marseille Université, Marseille France
| | - Jean-Marie Pagès
- Transporteurs Membranaires, Chimiorésistance et Drug Design, Facultés de Médecine et Pharmacie, UMR-MD1, IRBA - Aix-Marseille Université, Marseille France
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Acanthamoeba castellanii of the T4 genotype is a potential environmental host for Enterobacter aerogenes and Aeromonas hydrophila. Parasit Vectors 2013; 6:169. [PMID: 23742105 PMCID: PMC3682894 DOI: 10.1186/1756-3305-6-169] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 05/27/2013] [Indexed: 11/15/2022] Open
Abstract
Background Acanthamoeba can interact with a wide range of microorganisms such as viruses, algae, yeasts, protists and bacteria including Legionella pneumophila, Pseudomonas aeruginosa, Vibrio cholerae, Helicobacter pylori, Listeria monocytogenes, Mycobacterium spp., and Escherichia coli. In this capacity, Acanthamoeba has been suggested as a vector in the transmission of bacterial pathogens to the susceptible hosts. Methods Here, we used a keratitis isolate of A. castellanii of the T4 genotype and studied its interactions with two bacterial genera which have not been tested before, Enterobacter aerogenes, and Aeromonas hydrophila, as well as E. coli. Assays were performed to determine bacterial association with and invasion of A. castellanii. Additionally, bacterial survival intracellular of A. castellanii trophozoites as well as cysts was determined. Results All three bacterial isolates tested, associated, invaded, and survived inside A. castellanii trophozoites as well as A. castellanii cysts. However, E. aerogenes and E. coli exhibited significantly reduced association with and invasion of A. castellanii as compared with A. hydrophila (P < 0.01 using paired T-test, one tail distribution). In the long term survival assays, all three bacterial isolates tested remained viable inside A. castellanii trophozoites, while amoeba remained intact; however A. hydrophila exhibited higher survival inside amoebae (14.54 ± 3.3 bacteria:amoeba ratio) compared with E. aerogenes (3.96 ± 0.7 bacteria:amoeba ratio) and E. coli (5.85 ± 1.1 bacteria:amoeba ratio). A. hydrophila, E. coli, and E. aerogenes remained viable during the encystment process and exhibited higher levels of recovery from mature cysts (14.13 ± 0.89 A. hydrophila:amoeba ratio, 10.13 ± 1.17 E. aerogenes:amoeba ratio, and 11.95 ± 0.7 E. coli:amoeba ratio). Conclusions A. hydrophila and E. aerogenes also joined the ranks of other bacteria that could benefit from A. castellanii. Because cysts can be airborne, these findings suggest that Acanthamoeba is a potential vector in the transmission of A. hydrophila and E. aerogenes to susceptible hosts.
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Diene SM, Merhej V, Henry M, El Filali A, Roux V, Robert C, Azza S, Gavory F, Barbe V, La Scola B, Raoult D, Rolain JM. The rhizome of the multidrug-resistant Enterobacter aerogenes genome reveals how new "killer bugs" are created because of a sympatric lifestyle. Mol Biol Evol 2012; 30:369-83. [PMID: 23071100 DOI: 10.1093/molbev/mss236] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Here, we sequenced the 5,419,609 bp circular genome of an Enterobacter aerogenes clinical isolate that killed a patient and was resistant to almost all current antibiotics (except gentamicin) commonly used to treat Enterobacterial infections, including colistin. Genomic and phylogenetic analyses explain the discrepancies of this bacterium and show that its core genome originates from another genus, Klebsiella. Atypical characteristics of this bacterium (i.e., motility, presence of ornithine decarboxylase, and lack of urease activity) are attributed to genomic mosaicism, by acquisition of additional genes, such as the complete 60,582 bp flagellar assembly operon acquired "en bloc" from the genus Serratia. The genealogic tree of the 162,202 bp multidrug-resistant conjugative plasmid shows that it is a chimera of transposons and integrative conjugative elements from various bacterial origins, resembling a rhizome. Moreover, we demonstrate biologically that a G53S mutation in the pmrA gene results in colistin resistance. E. aerogenes has a large RNA population comprising 8 rRNA operons and 87 cognate tRNAs that have the ability to translate transferred genes that use different codons, as exemplified by the significantly different codon usage between genes from the core genome and the "mobilome." On the basis of our findings, the evolution of this bacterium to become a "killer bug" with new genomic repertoires was from three criteria that are "opportunity, power, and usage" to indicate a sympatric lifestyle: "opportunity" to meet other bacteria and exchange foreign sequences since this bacteria was similar to sympatric bacteria; "power" to integrate these foreign sequences such as the acquisition of several mobile genetic elements (plasmids, integrative conjugative element, prophages, transposons, flagellar assembly system, etc.) found in his genome; and "usage" to have the ability to translate these sequences including those from rare codons to serve as a translator of foreign languages.
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Affiliation(s)
- Seydina M Diene
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergents (URMITE), UMR7278 CNRS-IRD-INSERM, IHU Méditerranée Infection, Aix-Marseille Université, Marseille, France
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15
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Falagas ME, Kastoris AC, Kapaskelis AM, Karageorgopoulos DE. Fosfomycin for the treatment of multidrug-resistant, including extended-spectrum beta-lactamase producing, Enterobacteriaceae infections: a systematic review. THE LANCET. INFECTIOUS DISEASES 2010; 10:43-50. [PMID: 20129148 DOI: 10.1016/s1473-3099(09)70325-1] [Citation(s) in RCA: 348] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Rising rates of resistance to antimicrobial drugs among Enterobacteriaceae limit the choice of reliably active forms of these drugs. We evaluated the evidence on fosfomycin as a treatment option for infections caused by members of the family Enterobacteriaceae with advanced resistance to antimicrobial drugs, including producers of extended-spectrum beta-lactamase (ESBL). We systematically reviewed studies evaluating the antimicrobial activity, or the clinical effectiveness of fosfomycin. 17 antimicrobial-susceptibility studies were found and included in our Review, accounting for 5057 clinical isolates of Enterobacteriaceae with advanced resistance to antimicrobial drugs (4448 were producers of ESBL); 11 of the 17 studies reported that at least 90% of the isolates were susceptible to fosfomycin. Using a provisional minimum inhibitory concentration susceptibility breakpoint of 64 mg/L or less, 1604 (96.8%) of 1657 Escherichia coli isolates producing ESBL were susceptible to fosfomycin. Similarly, 608 (81.3%) of 748 Klebsiella pneumoniae isolates producing ESBL were susceptible to fosfomycin. In two clinical studies, oral treatment with fosfomycin-trometamol was clinically effective against complicated or uncomplicated lower urinary tract infections caused by ESBL-producing E coli in, cumulatively, 75 (93.8%) of the 80 patients evaluated. Initial clinical data support the use of fosfomycin for the treatment of urinary tract infections caused by these pathogens, although further research is needed.
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16
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17
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Chevalier J, Mulfinger C, Garnotel E, Nicolas P, Davin-Régli A, Pagès JM. Identification and evolution of drug efflux pump in clinical Enterobacter aerogenes strains isolated in 1995 and 2003. PLoS One 2008; 3:e3203. [PMID: 18787654 PMCID: PMC2527680 DOI: 10.1371/journal.pone.0003203] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 07/23/2008] [Indexed: 11/19/2022] Open
Abstract
Background The high mortality impact of infectious diseases will increase due to accelerated evolution of antibiotic resistance in important human pathogens. Development of antibiotic resistance is a evolutionary process inducing the erosion of the effectiveness of our arsenal of antibiotics. Resistance is not necessarily limited to a single class of antibacterial agents but may affect many unrelated compounds; this is termed ‘multidrug resistance’ (MDR). The major mechanism of MDR is the active expulsion of drugs by bacterial pumps; the treatment of Gram negative bacterial infections is compromised due to resistance mechanisms including the expression of efflux pumps that actively expel various usual antibiotics (ß-lactams, quinolones, …). Methodology/Principal Findings Enterobacter aerogenes has emerged among Enterobacteriaceae associated hospital infections during the last twenty years due to its faculty of adaptation to antibiotic stresses. Clinical isolates of E. aerogenes belonging to two strain collections isolated in 1995 and 2003 respectively, were screened to assess the involvement of efflux pumps in antibiotic resistance. Drug susceptibility assays were performed on all bacterial isolates and an efflux pump inhibitor (PAßN) previously characterized allowed to decipher the role of efflux in the resistance. Accumulation of labelled chloramphenicol was monitored in the presence of an energy poison to determine the involvement of active efflux on the antibiotic intracellular concentrations. The presence of the PAßN-susceptible efflux system was also identified in resistant E. aerogenes strains. Conclusions/Significance For the first time a noticeable increase in clinical isolates containing an efflux mechanism susceptible to pump inhibitor is report within an 8 year period. After the emergence of extended spectrum ß-lactamases in E. aerogenes and the recent characterisation of porin mutations in clinical isolates, this study describing an increase in inhibitor-susceptible efflux throws light on a new step in the evolution of mechanism in E. aerogenes.
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Affiliation(s)
| | - Céline Mulfinger
- UMR-MD1, IFR 48, Facultés de Médecine et de Pharmacie, Marseille, France
| | - Eric Garnotel
- UMR-MD1, IFR 48, Facultés de Médecine et de Pharmacie, Marseille, France
- Service de Biologie, H.I.A. Laveran, Marseille, France
| | - Pierre Nicolas
- UMR-MD1, IFR 48, Facultés de Médecine et de Pharmacie, Marseille, France
- IMTSSA, Marseille, France
| | - Anne Davin-Régli
- UMR-MD1, IFR 48, Facultés de Médecine et de Pharmacie, Marseille, France
| | - Jean-Marie Pagès
- UMR-MD1, IFR 48, Facultés de Médecine et de Pharmacie, Marseille, France
- * E-mail:
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18
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Successive emergence of extended-spectrum beta-lactamase-producing and carbapenemase-producing Enterobacter aerogenes isolates in a university hospital. J Clin Microbiol 2008; 46:1037-44. [PMID: 18234876 DOI: 10.1128/jcm.00197-07] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sixty-two clinical isolates of Enterobacter aerogenes resistant to expanded-spectrum cephalosporins were collected between July 2003 and May 2005. Among these isolates, 23 (37.1%) were imipenem (IPM) susceptible, and 39 (62.9%) were IPM insusceptible, of which 89.7% (35/39) were resistant and 10.3% (4/39) were intermediate. Isolate genotypes were compared by pulsed-field gel electrophoresis. Of 62 isolates, 48 belonged to epidemic pulsotype A (77.4%). This pulsotype included 37.5% and 58.4% of beta-lactam phenotypes b and a, respectively. Nine isolates (14.5%) belonged to pulsotype E, which included 22.3% and 77.7% of phenotypes b and a, respectively. The beta-lactamases with pIs of 5.4, 6.5, 8.2, and 8.2 corresponded to extended-spectrum beta-lactamases (ESBLs) TEM-20, TEM-24, SHV-5, and SHV-12, respectively. Of 39 IPM-insusceptible E. aerogenes isolates, 26 (66.6%) were determined to be metallo-beta-lactamase producers, by using a phenotypic method. Of these isolates, 24 harbored a bla(IMP-1) gene encoding a protein with a pI of >9.5, and two carried the bla(VIM-2) gene encoding a protein with a pI of 5.3, corresponding to beta-lactamases IMP-1 and VIM-2, respectively. The remaining 13 (33.4%) isolates were negative for the bla(IMP-1) and bla(VIM-2) genes but showed an alteration of their outer membrane proteins (OMPs). Ten of these isolates produced the two possible OMPs (32 and 42 kDa), with IPM MICs between 8 and 32 microg/ml, and three others produced only a 32-kDa OMP with IPM MICs >32 microg/ml. This work demonstrates that, in addition to resistance to expanded-spectrum cephalosporins, IPM resistance can occur in ESBL-producing E. aerogenes isolates by carbapenemase production or by the loss of porin in the outer membrane.
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Arpin C, Coulange L, Dubois V, André C, Fischer I, Fourmaux S, Grobost F, Jullin J, Dutilh B, Couture JF, Noury P, Lagrange I, Ducastaing A, Doermann HP, Quentin C. Extended-spectrum-beta-lactamase-producing Enterobacteriaceae strains in various types of private health care centers. Antimicrob Agents Chemother 2007; 51:3440-4. [PMID: 17591853 PMCID: PMC2043178 DOI: 10.1128/aac.01431-06] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During a 2004 survey, 49 extended-spectrum-beta-lactamase-producing enterobacteria were collected in 20 French private health care centers and one local hospital. They included 12 CTX-M-producing Escherichia coli strains (1.8% versus 0.3% in a 1999 survey). Most of them belonged to the same clone and contained a bla(CTX-M-15) gene on similar conjugative plasmids.
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Affiliation(s)
- Corinne Arpin
- UMR 5234 CNRS, Université de Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France.
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20
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Padhi A, Verghese B, Otta SK. Detecting the form of selection in the outer membrane protein C of Enterobacter aerogenes strains and Salmonella species. Microbiol Res 2007; 164:282-9. [PMID: 17418551 DOI: 10.1016/j.micres.2006.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Accepted: 12/13/2006] [Indexed: 11/22/2022]
Abstract
The types of selective pressure operating on the outer membrane protein C (ompC) of Enterobacter aerogenes strains, the causative agent for nosocomial infections, and Salmonella sp., the hazardous pathogen are investigated using the maximum likelihood-based codon substitution models. Although the rate of amino acid replacement to the silent substitution (omega) across the entire codon sites of ompC of E. aerogenes (omega=0.3194) and Salmonella sp. (omega=0.2047) indicate that the gene is subjected to purifying selection (i.e. omega<1), approximately 3.7% of ompC codon sites in E. aerogenes (omega=21.52) are under the influence of positive Darwinian selection (i.e. omega>1). Such contrast in the intensity of selective pressures in both pathogens could be associated with the differential response to the adverse environmental changes. In E. aerogenes, majority of the positively selected sites are located in the hypervariable cell-surface-exposed domains whereas the trans-membrane domains are functionally highly constrained.
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Affiliation(s)
- Abinash Padhi
- Department of Biological Science, University of Tulsa, Tulsa, OK-74104, USA.
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21
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Arpin C, Dubois V, Maugein J, Jullin J, Dutilh B, Brochet JP, Larribet G, Fischer I, Quentin C. Clinical and molecular analysis of extended-spectrum {beta}-lactamase-producing enterobacteria in the community setting. J Clin Microbiol 2005; 43:5048-54. [PMID: 16207960 PMCID: PMC1248438 DOI: 10.1128/jcm.43.10.5048-5054.2005] [Citation(s) in RCA: 36] [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
During a previous survey, five extended-spectrum beta-lactamase (ESBL)-producing enterobacteria (ESBLE) (two Enterobacter aerogenes isolates expressing TEM-24 b, two Escherichia coli isolates expressing TEM-21 or TEM-24 b, and one Klebsiella pneumoniae isolate expressing SHV-4/TEM-15) responsible for urinary tract infections (UTIs) were found among 1,584 strains collected from community patients. The aim of the present study was to elucidate the route of emergence of these typically nosocomial organisms in the community. Thus, the files of the five patients were analyzed over at least a decade, and potentially related ESBLE from hospitals or clinics were examined. Their enzymes were characterized at a molecular level, and the strains were typed by amplified-primed PCR, enterobacterial repetitive intergenic consensus PCR, and restriction plasmid profile. All patients (C1 to C5) had risk factors for ESBLE acquisition, including past history of hospitalization (2.5 to 23 months before). Four (C1 and C3 to C5) had previously received antibiotics (concomitantly to 35 months earlier), two (C1 and C3) had indwelling urinary catheters and recurrent UTIs, and three (C2, C3, and C5) formerly experienced ESBLE-induced UTIs (2 to 11 months before). The same ESBLE and/or an identical or similar ESBL-encoding plasmid was identified in the hospital ward (C1 to C4) or in a clinic (C5) where the patients had previously resided. Patients C1 and C4, infected with different ESBLE carrying a closely related plasmid, were hospitalized in the same unit. Persistence of ESBLE over at least a 5-year period was demonstrated for patient C3. Thus, community-acquired UTIs in these patients likely resulted from nosocomially acquired ESBLE or an ESBL-encoding plasmid followed by a prolonged digestive carriage.
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Affiliation(s)
- Corinne Arpin
- EA525, Laboratoire de Microbiologie, Faculté de Pharmacie, Université de Bordeaux 2, Bordeaux, France
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22
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Jiang X, Ni Y, Jiang Y, Yuan F, Han L, Li M, Liu H, Yang L, Lu Y. Outbreak of infection caused by Enterobacter cloacae producing the novel VEB-3 beta-lactamase in China. J Clin Microbiol 2005; 43:826-31. [PMID: 15695687 PMCID: PMC548041 DOI: 10.1128/jcm.43.2.826-831.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over a 4-month period from November 2002 to February 2003, 27 ceftazidime-resistant or cefotaxime-resistant nonrepetitive Enterobacter cloacae isolates were collected from 27 patients hospitalized at HuaShan Hospital, Shanghai, People's Republic of China. The Etest did not detect extended-spectrum beta-lactamases (ESBLs) in those 27 isolates; however, screening by the NCCLS ESBL disk test and confirmatory tests detected ESBLs in 4 of 27 isolates and PCR detected ESBLs in 23 of 27 isolates. The majority of ESBL producers exhibited the same repetitive extragenic palindromic PCR pattern but harbored different ESBL genes. CTX-M-3 was the most prevalent ESBL in our study. Interestingly, 12 clonally related E. cloacae isolates possessed a novel bla(VEB)-type beta-lactamase, bla(VEB-3). Bla(VEB-3) was encoded by the chromosome and was located in an integron. Nine of the 12 isolates harbored both the bla(VEB-3) and the bla(CTX-M-3)-like ESBLs. This is the first report of a VEB-1-like ESBL in China and the first report of the simultaneous presence of VEB-1 and CTX-M-3-like ESBLs in an isolate.
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Affiliation(s)
- Xiaofei Jiang
- Center of Laboratory Medicine of Huashan Hospital, Fudan University, 12 Central Urumqi Rd., Shanghai 200040, People's Republic of China
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23
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Thiolas A, Bollet C, La Scola B, Raoult D, Pagès JM. Successive emergence of Enterobacter aerogenes strains resistant to imipenem and colistin in a patient. Antimicrob Agents Chemother 2005; 49:1354-8. [PMID: 15793111 PMCID: PMC1068582 DOI: 10.1128/aac.49.4.1354-1358.2005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterobacter aerogenes is an agent of hospital-acquired infection that exhibits a remarkable resistance to beta-lactam antibiotics during therapy. Five successive isolates of E. aerogenes infecting a patient and exhibiting a multiresistance phenotype to beta-lactam antibiotics and fluoroquinolones were investigated. Among these clinical strains, four presented resistant phenotypes during successive imipenem and colistin treatments. The involved resistance mechanisms exhibited by the successive isolates were associated with alterations of the outer membrane that caused a porin decrease and lipopolysaccharide modifications.
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Affiliation(s)
- Aurélie Thiolas
- Enveloppe Bactérienne, Perméabilité et Antibiotiques, EA2197, IFR48, Faculté de Médecine, 27 Blvd. Jean Moulin, 13385 Marseille Cedex 05, France
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24
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Ghisalberti D, Masi M, Pagès JM, Chevalier J. Chloramphenicol and expression of multidrug efflux pump in Enterobacter aerogenes. Biochem Biophys Res Commun 2005; 328:1113-8. [PMID: 15707992 DOI: 10.1016/j.bbrc.2005.01.069] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Indexed: 10/25/2022]
Abstract
Chloramphenicol has been reported to act as an inducer of the multidrug resistance in Escherichia coli. A resistant variant able to grow on plates containing 64 microg/ml chloramphenicol was obtained from the Enterobacter aerogenes ATCC 13048-type strain. Chloramphenicol resistance was due to an active efflux of this antibiotic and it was associated with resistance to fluoroquinolones and tetracycline, but not to aminoglycoside or beta-lactam antibiotics. MDR in the chloramphenicol-resistant variant is linked to the overexpression of the major AcrAB-TolC efflux system. This overexpression seems unrelated to the global Mar and the local AcrR regulatory pathways.
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Affiliation(s)
- Didier Ghisalberti
- Enveloppe Bactérienne, Perméabilité et Antibiotiques, EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France
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25
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Lavigne JP, Bouziges N, Chanal C, Mahamat A, Michaux-Charachon S, Sotto A. Molecular epidemiology of Enterobacteriaceae isolates producing extended-spectrum beta-lactamases in a French hospital. J Clin Microbiol 2004; 42:3805-8. [PMID: 15297534 PMCID: PMC497652 DOI: 10.1128/jcm.42.8.3805-3808.2004] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In 2002, 80 isolates of Enterobacteriaceae producing extended-spectrum beta-lactamases (ESBLs) were collected from infected patients in our hospital. Enterobacter aerogenes was the most common bacterium isolated from all specimens (36.5%). The ESBLs were predominantly (90%) TEM derivatives (TEM-24, TEM-3). Pulsed-field gel electrophoresis highlighted that E. aerogenes, Klebsiella pneumoniae, and Citrobacter koseri had a clonal propagation.
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Affiliation(s)
- Jean-Philippe Lavigne
- Laboratoire Universitaire d'Antibiologie, Faculté de Médecine, Ave. Kennedy, 30900 Nîmes, France.
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26
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Bornet C, Saint N, Fetnaci L, Dupont M, Davin-Régli A, Bollet C, Pagès JM. Omp35, a new Enterobacter aerogenes porin involved in selective susceptibility to cephalosporins. Antimicrob Agents Chemother 2004; 48:2153-8. [PMID: 15155215 PMCID: PMC415628 DOI: 10.1128/aac.48.6.2153-2158.2004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Enterobacter aerogenes, beta-lactam resistance often involves a decrease in outer membrane permeability induced by modifications of porin synthesis. In ATCC 15038 strain, we observed a different pattern of porin production associated with a variable antibiotic susceptibility. We purified Omp35, which is expressed under conditions of low osmolality and analyzed its pore-forming properties in artificial membranes. This porin was found to be an OmpF-like protein with high conductance values. It showed a noticeably higher conductance compared to Omp36 and a specific location of WNYT residues in the L3 loop. The importance of the constriction region in the porin function suggests that this organization is involved in the level of susceptibility to negative large cephalosporins such as ceftriaxone by bacteria producing the Omp35 porin subfamily.
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Affiliation(s)
- Charléric Bornet
- Enveloppe Bactérienne, Perméabilité et Antibiotiques, EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
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27
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Arpin C, Dubois V, Coulange L, André C, Fischer I, Noury P, Grobost F, Brochet JP, Jullin J, Dutilh B, Larribet G, Lagrange I, Quentin C. Extended-spectrum beta-lactamase-producing Enterobacteriaceae in community and private health care centers. Antimicrob Agents Chemother 2004; 47:3506-14. [PMID: 14576109 PMCID: PMC253776 DOI: 10.1128/aac.47.11.3506-3514.2003] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In 1999, 39 of 2,599 isolates of the family Enterobacteriaceae (1.5%) collected by eight private laboratories in the Aquitaine region in France produced an extended-spectrum beta-lactamase (ESBL). Among these were 19 Enterobacter aerogenes isolates; 8 Klebsiella pneumoniae isolates; 6 Escherichia coli isolates; 3 Proteus mirabilis isolates; and 1 isolate each of Serratia marcescens, Morganella morganii, and Providencia stuartii. ESBL producers were isolated from 38 patients, including 33 residents of 11 clinics or nursing homes and 5 ambulatory patients. Seven different ESBLs were characterized. These mainly consisted of TEM-24 (25 isolates) and TEM-21 (9 isolates), but TEM-15 (2 isolates) and TEM-3, TEM-19, SHV-4, and CTX-M-1 (1 isolate each) were also characterized. Seven strains showed the coexistence of different TEM- and/or SHV-encoding genes, including a new SHV-1 variant, SHV-44, defined by the substitution R205L previously reported for SHV-3 in association with S238G. The epidemiology of the ESBL producers was investigated by random amplification of polymorphic DNA, typing by enterobacterial repetitive intergenic consensus PCR, analysis of resistance cotransferred with the ESBL, and analysis of the restriction profiles of the ESBL-encoding plasmids. Of the TEM-24-expressing strains, 18 were E. aerogenes isolates, including 9 from the same clinic, that were representatives of the epidemic clone disseminating in France. Of the TEM-21-producing strains that belonged to different species of the family Enterobacteriaceae (E. coli, K. pneumoniae, and P. mirabilis), 8 were isolated in the same nursing home. Outbreaks due to strain and/or plasmid dissemination in these clinic and nursing home were demonstrated. The presence of ESBL producers in five ambulatory patients probably resulted from nosocomial acquisition. Our data highlight the serious need to monitor patients for ESBL-producing Enterobacteriaceae in general practice.
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Affiliation(s)
- Corinne Arpin
- Laboratoire de Microbiologie, Université de Bordeaux 2, 33076 Bordeaux Cedex, France.
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28
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Chevalier J, Bredin J, Mahamoud A, Malléa M, Barbe J, Pagès JM. Inhibitors of antibiotic efflux in resistant Enterobacter aerogenes and Klebsiella pneumoniae strains. Antimicrob Agents Chemother 2004; 48:1043-6. [PMID: 14982806 PMCID: PMC353160 DOI: 10.1128/aac.48.3.1043-1046.2004] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Enterobacter aerogenes and Klebsiella pneumoniae, efflux provides efficient extrusion of antibiotics and contributes to the multidrug resistance phenotype. One of the alkoxyquinoline derivatives studied here, 2,8-dimethyl-4-(2'-pyrrolidinoethyl)-oxyquinoline, restores noticeable drug susceptibility to resistant clinical strains. Analyses of energy-dependent chloramphenicol efflux indicate that this compound inhibits the efflux pump mechanism and improves the activity of structurally unrelated antibiotics on multidrug-resistant E. aerogenes and K. pneumoniae isolates.
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Affiliation(s)
- Jacqueline Chevalier
- EA2197, Faculté de Médecine, Université de la Méditerranée, 13385 Marseille Cedex 05, France
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Burnichon G, Le Floch MF, Virmaux M, Baron R, Tandé D, Lejeune B. Épidémie à Enterobacter aerogenes en pédiatrie. Med Mal Infect 2004; 34:166-70. [PMID: 15619887 DOI: 10.1016/j.medmal.2003.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Within the framework of breast milk control the hygiene laboratory of Brest hospital isolates, on 3 January 1996 a strain of Enterobacter aerogenes secretory of cephalosporinase in the breast milk of a mother whose child was hospitalized in neonatalogy. On 15 April 1996 a new strain of E. aerogenes is isolated from another mother's breast milk. Until 18 August 1997, 21 samples of breast milk were tested positive to this bacteria. During the same period, E. aerogenes was isolated in 26 children under 1 year of age, 11 of which were infected and 15 colonized. The breast milk did not correspond to those of the mothers of the infected or colonized children. All the strains presented the same antibioresistance. The pulsed-field gel electrophoresis showed that the children's strains, those colonized or infected as well as those isolated in breast milk had the same restriction profile. The epidemiological study concerned the biberonnery-lactarium. The biberonnery's staff is the same as the staff of the lactarium. A portage was searched for among the members of the staff of these units, but without success. The search for E. aerogenes in the environment and in baby-food, others than breast milk was negative. Finally, we did not find any source for these contagions. The only hypothesis we have retained is that of a common source from the biberonnery-lactarium, but without being able to bring any proof to it. Following this epidemic, we have revised all the working modalities and practices with the staff of the biberonnery-lactarium.
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Affiliation(s)
- G Burnichon
- Service de santé publique, hygiène hospitalière et evaluation, CHU Morvan, 5, avenue Foch, 29609 Brest , France.
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Quentin C, Arpin C, Dubois V, André C, Lagrange I, Fischer I, Brochet JP, Grobost F, Jullin J, Dutilh B, Larribet G, Noury P. Antibiotic resistance rates and phenotypes among isolates of Enterobacteriaceae in French extra-hospital practice. Eur J Clin Microbiol Infect Dis 2004; 23:185-93. [PMID: 14986156 DOI: 10.1007/s10096-003-1081-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Antibiotic resistance among members of the family Enterobacteriaceae was prospectively surveyed by eight French private laboratories over a 5-month period in 1999. A total of 2,599 consecutive and nonduplicate strains were collected, mainly (60.9%) from patients in the community. Most strains (82.9%) derived from urine. Escherichia coli was the predominant (73.9%) organism isolated. The overall rates of antibiotic resistance were as follows: amoxicillin, 53.4%; amoxicillin-clavulanic acid, 27.3%; ticarcillin, 44.2%; piperacillin-tazobactam, 3.2%; cephalothin, 29.2%; cefuroxime, 14.7%; cefoxitin, 11.5%; ceftazidime, 3.6%; cefotaxime, 2.8%; cefepime, 0.3%; imipenem, 0.1%; gentamicin (G), 3.8%; tobramycin (T), 5.0%; netilmicin (Nt), 3.7%; amikacin (A), 0.7%; nalidixic acid, 14.3%; ofloxacin, 10.4%; cotrimoxazole, 21.1%; nitrofurantoin, 12.7%; fosfomycin, 5.2%; tetracycline, 50.1%; and colistin, 12.5%. Beta-lactam resistance phenotypes essentially comprised penicillinase production (33.9%), overexpression of chromosomal cephalosporinase (4.6%), and synthesis of inhibitor-resistant TEM/OXA enzymes (1.5%) or extended-spectrum beta-lactamases (1.5%). Aminoglycoside resistance phenotypes consisted of GTNt (93 strains), TNtA (68 strains), GTNtA (14 strains), T (4 strains), GT (3 strains), G (1 strain), and reduced uptake/permeability (3 strains). Most of the nalidixic acid-resistant strains were resistant to ofloxacin (72.8%). Antibiotic resistance rates and phenotypes varied widely according to the bacterial group and the source of the strains. Significantly higher rates were observed in private healthcare centers than in the community, due to a higher proportion of both resistant species and resistant strains. However, multidrug-resistant isolates, including five extended-spectrum beta-lactamase-producing strains, were also recovered from the community.
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Affiliation(s)
- C Quentin
- Laboratoire de Microbiologie, Faculté de Pharmacie, Université de Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France.
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31
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MOLDOVAN C, CRISTEA C, A.SILBERG L, MARAMOUD A, DELEANU C, BARBE J. A CONVENIENT ROUTE TO 1,4-DIHYDRO-3-CYANO-10-METHYL-PYRIDO[3,2-g)-QUINOLINE DERIVATIVES AS KEY-INTERMEDIATES FOR THE SYNTHESIS OF NOVEL MDR REVERSAL AGENTS. HETEROCYCL COMMUN 2004. [DOI: 10.1515/hc.2004.10.1.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Malléa M, Mahamoud A, Chevalier J, Alibert-Franco S, Brouant P, Barbe J, Pagès JM. Alkylaminoquinolines inhibit the bacterial antibiotic efflux pump in multidrug-resistant clinical isolates. Biochem J 2003; 376:801-5. [PMID: 12959639 PMCID: PMC1223807 DOI: 10.1042/bj20030963] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2003] [Revised: 08/26/2003] [Accepted: 09/05/2003] [Indexed: 11/17/2022]
Abstract
Over the last decade, MDR (multidrug resistance) has increased worldwide in microbial pathogens by efflux mechanisms, leading to treatment failures in human infections. Several Gram-negative bacteria efflux pumps have been described. These proteinaceous channels are capable of expelling structurally different drugs across the envelope and conferring antibiotic resistance in various bacterial pathogens. Combating antibiotic resistance is an urgency and the blocking of efflux pumps is an attractive response to the emergence of MDR phenotypes in infectious bacteria. In the present study, various alkylaminoquinolines were tested as potential inhibitors of drug transporters. We showed that alkylaminoquinolines are capable of restoring susceptibilities to structurally unrelated antibiotics in clinical isolates of MDR Gram-negative bacteria. Antibiotic efflux studies indicated that 7-nitro-8-methyl-4-[2'-(piperidino)ethyl]aminoquinoline acts as an inhibitor of the AcrAB-TolC efflux pump and restores a high level of intracellular drug concentration. Inhibitory activity of this alkylaminoquinoline is observed on clinical isolates showing different resistance phenotypes.
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Affiliation(s)
- Monique Malléa
- EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France
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Aibinu IE, Ohaegbulam VC, Adenipekun EA, Ogunsola FT, Odugbemi TO, Mee BJ. Extended-spectrum beta-lactamase enzymes in clinical isolates of Enterobacter species from Lagos, Nigeria. J Clin Microbiol 2003; 41:2197-200. [PMID: 12734278 PMCID: PMC154721 DOI: 10.1128/jcm.41.5.2197-2200.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over a 9-month period, 8 of 40 nonduplicate isolates of Enterobacter spp. producing extended-spectrum beta-lactamase (ESBL) were detected for the first time from two hospitals in Lagos, Nigeria. Microbiologic and molecular analysis confirmed the presence of ESBL. Only four isolates transferred ESBL resistance as determined by the conjugation test, and pulsed-field gel electrophoresis showed genetically unrelated isolates.
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Affiliation(s)
- I E Aibinu
- Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, P.M.B 12003, Lagos, Nigeria.
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Gayet S, Chollet R, Molle G, Pagès JM, Chevalier J. Modification of outer membrane protein profile and evidence suggesting an active drug pump in Enterobacter aerogenes clinical strains. Antimicrob Agents Chemother 2003; 47:1555-9. [PMID: 12709321 PMCID: PMC153306 DOI: 10.1128/aac.47.5.1555-1559.2003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two clinical strains of Enterobacter aerogenes that exhibited phenotypes of multiresistance to beta-lactam antibiotics, fluoroquinolones, chloramphenicol, tetracycline, and kanamycin were investigated. Both strains showed a porin pattern different from that of a susceptible strain, with a drastic reduction in the amount of the major porin but with an apparently conserved normal structure (size and immunogenicity), together with overproduction of two known outer membrane proteins, OmpX and LamB. In addition, the full-length O-polysaccharide phenotype was replaced by a semirough Ra phenotype. Moreover, in one isolate the intracellular accumulation of chloramphenicol was increased in the presence of the energy uncoupler carbonyl cyanide m-chlorophenylhydrazone, suggesting an energy-dependent efflux of chloramphenicol in this strain. The resistance strategies used by these isolates appear to be similar to that induced by stress in Escherichia coli cells.
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Affiliation(s)
- Stéphane Gayet
- EA2197-IFR 48, Faculté de Médecine, 13385 Marseille Cedex 05. UMR 5048, CNRS, U554 INSERM, 34090 Montpellier, France
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35
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Bornet C, Chollet R, Malléa M, Chevalier J, Davin-Regli A, Pagès JM, Bollet C. Imipenem and expression of multidrug efflux pump in Enterobacter aerogenes. Biochem Biophys Res Commun 2003; 301:985-90. [PMID: 12589810 DOI: 10.1016/s0006-291x(03)00074-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Imipenem is often used to treat intensive care unit patients infected by Enterobacter aerogenes, but it is leading to an increasing number of antibiotic resistant strains. Clinical isolates and imipenem resistant variants presented a high level of resistance to beta-lactam antibiotic group and to chemically unrelated drugs. We report here that imipenem selects strains which contain active efflux pumps ejecting various unrelated antibiotics including quinolones, tetracycline, and chloramphenicol. An increase of AcrA, an efflux pump component, was observed in the imipenem resistant variants. The overexpression of marA, involved in the genetic control of membrane permeability via porin and efflux pump expression, indicated the activation of the resistance genetic cascade in imipenem resistant variants.
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Affiliation(s)
- Charléric Bornet
- Enveloppe Bactérienne, Perméabilité et Antibiotiques, EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 05, Marseille cedex, France
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36
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Yigit H, Anderson GJ, Biddle JW, Steward CD, Rasheed JK, Valera LL, McGowan JE, Tenover FC. Carbapenem resistance in a clinical isolate of Enterobacter aerogenes is associated with decreased expression of OmpF and OmpC porin analogs. Antimicrob Agents Chemother 2002; 46:3817-22. [PMID: 12435682 PMCID: PMC132746 DOI: 10.1128/aac.46.12.3817-3822.2002] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2002] [Revised: 04/09/2002] [Accepted: 08/13/2002] [Indexed: 11/20/2022] Open
Abstract
We investigated the mechanism of imipenem resistance in Enterobacter aerogenes strain 810, a clinical isolate from the United States for which the imipenem MIC was 16 micro g/ml and the meropenem MIC was 8 micro g/ml. An imipenem-susceptible revertant, strain 810-REV, was obtained after multiple passages of the strain on nonselective media. For the revertant, the imipenem MIC was =1 micro g/ml and the meropenem MIC was =0.25 micro g/ml. Cefepime MICs also decreased from 8 to 1 micro g/ml; however, the MICs of ceftazidime (>/=128 micro g/ml), cefoxitin (>/=32 micro g/ml), and cefotaxime (>/=64 micro g/ml) remained the same. The beta-lactamase and porin profiles of the parent, the revertant, and carbapenem-susceptible type strain E. aerogenes ATCC 13048 were determined. Strains 810 and 810-REV each produced two beta-lactamases with pIs of 8.2 and 5.4. The beta-lactamase activities of the parent and revertant were similar, even after induction with subinhibitory concentrations of imipenem. While 810-REV produced two major outer membrane proteins of 42 and 39 kDa that corresponded to Escherichia coli porins OmpC and OmpF, respectively, the parent strain appeared to produce similar quantities of the 39-kDa protein (OmpF) but decreased amounts of the 42-kDa protein (OmpC). When the parent strain was grown in the presence of imipenem, the 42-kDa protein was not detectable by gel electrophoresis. However, Western blot analysis of the outer membrane proteins of the parent and revertant with polyclonal antisera raised to the OmpC and OmpF analogs of Klebsiella pneumoniae (anti-OmpK36 and anti-OmpK35, respectively) showed that strain 810 expressed only the 42-kDa OmpC analog in the absence of imipenem (the 39-kDa protein was not recognized by the anti-OmpF antisera) and neither the OmpC nor the OmpF analog in the presence of imipenem. The OmpC analog is apparently down-regulated in the presence of imipenem; however, 810-REV expressed both OmpC and OmpF analogs. These data suggest that imipenem resistance in E. aerogenes 810 is primarily associated with the lack of expression of the analogs of the OmpC (42-kDa) and OmpF (39-kDa) outer membrane proteins, which also results in decreased susceptibility to meropenem and cefepime.
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Affiliation(s)
- Hesna Yigit
- Division of Healthcare Quality Promotion, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
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Goshi S, Taneike I, Nakagawa S, Kojio S, Tamura Y, Ohara T, Ozaki K, Tsukada H, Aoki Y, Asakura H, Gejyo F, Itoh M, Yamamoto T. DNA analysis of nosocomial infection by Enterobacter aerogenes in three cases of septicaemia in Japan. J Hosp Infect 2002; 51:221-5. [PMID: 12144802 DOI: 10.1053/jhin.2002.1255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ceftazidime-resistant Enterobacter aerogenes was isolated from blood cultures of three patients with fever. DNA analysis using pulsed-field gel electrophoresis and ribosomal RNA gene restriction digest pattern analysis revealed that the strains were clonally similar to each other with a 79.3-96.0% homology. The same strain of E. aerogenes was isolated from a three-way stopcock connected to the indwelling catheter in one of the patients at a concentration of 45 cfu/mL. A similar strain was also isolated from the urine of one other patient on the same floor. The data suggest that E. aerogenes caused septicaemia via low bacterial contamination of a three-way stopcock in a peripheral drip intravenous infusion system in at least one patient, and that the outbreak of E. aerogenes infections was due to clonally-related strains.
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Affiliation(s)
- S Goshi
- Division of Bacteriology, Department of Infectious Disease Control and International Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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38
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Malléa M, Chevalier J, Eyraud A, Pagès JM. Inhibitors of antibiotic efflux pump in resistant Enterobacter aerogenes strains. Biochem Biophys Res Commun 2002; 293:1370-3. [PMID: 12054665 DOI: 10.1016/s0006-291x(02)00404-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enterobacter aerogenes, a nosocomial pathogen, is frequently exhibiting multidrug resistance mechanisms associated with a change in membrane permeability. In clinical isolates, active efflux plays a prominent role in antibiotic resistance. We report here the effect of three unrelated compounds that are able to restore a noticeable antibiotic susceptibility to resistant strains. The targeting of various parameters which contribute to the efficacy of the efflux mechanism, such as energy, flux selectivity, or functional assembly of the membrane complex, increases the intracellular chloramphenicol concentration in resistant isolates.
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Affiliation(s)
- Monique Malléa
- EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France
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39
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Stürenburg E, Sobottka I, Mack D, Laufs R. Cloning and sequencing of Enterobacter aerogenes OmpC-type osmoporin linked to carbapenem resistance. Int J Med Microbiol 2002; 291:649-54. [PMID: 12008919 DOI: 10.1078/1438-4221-00175] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Using outbreak-related strains of Enterobacter aerogenes, we cloned and sequenced ompK39, the structural gene coding for outer membrane protein OmpK39. Its lack of expression was closely associated with a phenotype exhibiting low-level carbapenem resistance. Detailed alignment of the predicted amino acid sequence revealed that OmpK39 is a member of the OmpC subclass of enterobacterial porins, with the highest degree of homology to Klebsiella pneumoniae OmpK36. Based on a computerized alignment including Escherichia coli PhoE and OmpF, the 3D structures of which are known from X-ray studies, OmpK39 can be assumed to form the typical beta-barrel structure which is common to all enterobacterial porins. Since no inhibitory DNA sequences could be detected in ompk39 in the resistant strains, porin deficiency leading to carbapenem resistance seems to involve alterations in key regulatory genes and/or the promotor sequence rather than a direct mutation in the structural gene.
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Affiliation(s)
- Enno Stürenburg
- Institut für Meidzinische Mikrobiologie und Immunologie, Universitäts-Klinikum Eppendorf, Universität Hamburg, Germany.
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40
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Les bactéries productrices de bêtalactamases à spectre étendu : étude au centre hospitalo-universitaire de Strasbourg. Med Mal Infect 2002. [DOI: 10.1016/s0399-077x(02)00361-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Baraniak A, Fiett J, Sulikowska A, Hryniewicz W, Gniadkowski M. Countrywide spread of CTX-M-3 extended-spectrum beta-lactamase-producing microorganisms of the family Enterobacteriaceae in Poland. Antimicrob Agents Chemother 2002; 46:151-9. [PMID: 11751126 PMCID: PMC126981 DOI: 10.1128/aac.46.1.151-159.2002] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eighty-four clinical isolates of the family Enterobacteriaceae, recovered from 1998 to 2000 in 15 hospitals in 10 Polish cities, were analyzed. All the isolates produced beta-lactamases with pIs of 8.4 and 5.4, and the pI 8.4 enzymes were demonstrated to hydrolyze cefotaxime but not ceftazidime in the in vitro bioassay. PCR analysis and DNA sequencing have revealed that in all cases the pI 8.4 beta-lactamase was probably the CTX-M-3 extended-spectrum beta-lactamase (ESBL) variant, which was originally identified in 1996 in Praski Hospital in Warsaw. In the majority of isolates, bla(CTX-M-3) genes resided within large conjugative plasmids with similar fingerprints, which, in the context of the high degree of diversity of the randomly amplified polymorphic DNA types of the isolates, suggested that horizontal transfer of plasmids was likely the main mechanism of CTX-M-3 spread. The dissemination of plasmids was probably preceded by the center-to-center transmission of several strains, as indicated by the identification by pulsed-field gel electrophoresis of closely related or possibly related Klebsiella pneumoniae, Escherichia coli, and Citrobacter freundii isolates in five different hospitals. CTX-M-3-producing organisms revealed a very high degree of diversity in beta-lactam resistance levels and patterns. This was attributed to several factors, such as the production of other beta-lactamases including additional ESBLs, possible quantitative variations in CTX-M-3 expression, segregation of AmpC derepressed mutants, and permeability alterations.
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Affiliation(s)
- Anna Baraniak
- Sera & Vaccines Central Research Laboratory, 00-725 Warsaw, Poland
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42
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Chevalier J, Atifi S, Eyraud A, Mahamoud A, Barbe J, Pagès JM. New pyridoquinoline derivatives as potential inhibitors of the fluoroquinolone efflux pump in resistant Enterobacter aerogenes strains. J Med Chem 2001; 44:4023-6. [PMID: 11689091 DOI: 10.1021/jm010911z] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enterobacter aerogenes, one of the most frequently isolated nosocomial pathogens in France, is exhibiting increasing multidrug resistance mechanisms associated with a change in membrane permeability. For drugs of the quinolone family, mutations in the target and active efflux play a prominent role in the resistance. We report here the effect of several pyridoquinoline derivatives that restore a noticeable fluoroquinolone accumulation to resistant strains that overexpress the MarA activator. Studies of the energy-dependent quinolone efflux indicate that the most efficient derivatives tested probably inhibit the resistance process by acting as substrate competitors on the pump extruding intracellular norfloxacin.
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Affiliation(s)
- J Chevalier
- CJF9606-EA2197, Faculté de Médecine, Université de la Méditerranée, 13385 Marseille, Cedex 05, France
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43
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Vanhoof R, Bérin C, Carpentier M, Fagnart O, Glupczynski Y, Mans I, Nyssen HJ, Surmont I, Van Nimmen L. Comparative in vitro activity of temocillin and other antimicrobial agents against Enterobacteriaceae isolated from patients admitted to five Belgian hospitals. Acta Clin Belg 2001; 56:354-9. [PMID: 11881320 DOI: 10.1179/acb.2001.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Temocillin, a methoxy-derivative of the broad-spectrum penicillin, ticarcillin, has been introduced into clinical practice in Belgium in 1988. Since then, not many surveys of its in vitro activity have been published. This study addresses this issue in a prospective collection of 300 consecutive Gram-negative isolates originating from in-patients in five general hospitals throughout Belgium. In addition to temocillin, seven common antibiotics were tested: amoxicillin-clavulanate, piperacillin-tazobactam, cefotaxime, aztreonam, meropenem, ciprofloxacin and amikacin. Meropenem appeared to exhibit the best activity overall, whereas amoxicillin-clavulanate scored the worst. Cumulative MIC plot for two subsets of organisms are given: temocillin, meropenem and cefotaxime are the most active on E. coli and Klebsiella spp., while a significant percentage is resistant to ciprofloxacin and amoxicillin-clavulanate. In the group of inducible Enterobacteriaceae, temocillin, meropenem and amikacin are the most active drugs, while the activity of amoxicillin-clavulanate, piperacillin-tazobactam, cefotaxime and ciprofloxacin is largely decreased. Taking this well preserved in vitro activity of temocillin into account, and looking at its convenient pharmacokinetics and low cost of acquisition, this drug may prove a useful alternative in the treatment of severe nosocomial infections.
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Affiliation(s)
- R Vanhoof
- Pasteurinstituut-Brussel, Eenheid Antibiotica-onderzoek, Engelandstraat 642, B-1180 Brussel
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Gniadkowski M. Evolution and epidemiology of extended-spectrum beta-lactamases (ESBLs) and ESBL-producing microorganisms. Clin Microbiol Infect 2001; 7:597-608. [PMID: 11737084 DOI: 10.1046/j.1198-743x.2001.00330.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The rapid and irrepressible increase in antimicrobial resistance of pathogenic bacteria that has been observed over the last two decades is widely accepted to be one of the major problems of human medicine today. Several aspects of this situation are especially worrying. There are resistance mechanisms that eliminate the use of last-choice antibiotics in the treatment of various kinds of infection. Many resistance mechanisms that emerge and spread in bacterial populations are those of wide activity spectra, which compromise all or a majority of drugs belonging to a given therapeutic group. Some mechanisms of great clinical importance require specific detection procedures, as they may not confer clear resistance in vitro on the basis of the interpretive criteria used in standard susceptibility testing. Finally, multiple mechanisms affecting the same and/or different groups of antimicrobials coexist and are even co-selected in more and more strains of pathogenic bacteria. The variety of beta-lactamases with wide spectra of substrate specificity illustrates very well all the phenomena mentioned above. Being able to hydrolyze the majority of beta-lactams that are currently in use, together they constitute the most important resistance mechanism of Gram-negative rods. Three major groups of these enzymes are usually distinguished, class C cephalosporinases (AmpC), extended-spectrum beta-lactamases (ESBLs) and different types of beta-lactamases with carbapenemase activity, of which the so-called class B metallo-beta-lactamases (MBLs) are of the greatest concern. This review is focused on various aspects of the evolution and epidemiology of ESBLs; it does not cover the problems of ESBL detection and clinical relevance of infections caused by ESBL-producing organisms.
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Affiliation(s)
- M Gniadkowski
- Sera & Vaccines Central Research Laboratory, ul. Chelmska 30/34, 00-725 Warsaw, Poland.
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45
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Glupczynski Y, Delmée M, Goossens H, Struelens M. Distribution and prevalence of antimicrobial resistance among gram-negative isolates in intensive care units (ICU) in Belgian hospitals between 1996 and 1999. Acta Clin Belg 2001; 56:297-306. [PMID: 11770225 DOI: 10.1179/acb.2001.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE To assess the distribution and prevalence of resistance rates among Gram-negative isolates in Belgian intensive care units (ICUs) between 1996 and 1999. METHODS During 1996-1997 and 1998-1999, over a total period of 10 and 9 months respectively, members of the NPRS Belgian Study group collected, on clinical indications, 3029 consecutive initial isolates of Gram-negative bacteria from patients admitted to 26 Belgian hospitals and performed minimal inhibitory concentration (MIC) determinations by means of the E-test. Break-points were defined according to the criteria of the NCCLS. RESULTS The overall distribution of bacterial species was, in decreasing order of frequency: Pseudomonas aeruginosa > E. coli > E. aerogenes > K. pneumoniae > P. mirabilis > S. marcescens > E. cloacae > K. oxytoca > M. morganii > Stenotrophomonas maltophilia > Acinetobacter spp. All together these species and genera constituted about 90% of all isolates. The frequency of resistance for all the initial Gram-negative isolates in 1998-9 were: amoxicillin-clavulanic acid 60%, piperacillin 31%, piperacillin-tazobactam 20%, cefuroxime 58%, ceftriaxone 31%, ceftazidime 17%, aztreonam 23%, cefepime 10%, imipenem 13%, gentamicin 12%, amikacin 12% and ciprofloxacin 21%. Apart for an increase in multiple drug resistance among P. aeruginosa isolates, no significant trends were observed neither in species distribution nor in the overall prevalence of antimicrobial resistance among Gram-negative isolates from Belgian ICUs between 1996-7 and 1998-9. CONCLUSIONS Among Gram-negative isolates in Belgian ICUs, a very high frequency of resistance was seen to amoxicillin-clavulanic acid and cefuroxime, and rather high frequencies of resistance to piperacillin, ceftriaxone and aztreonam. Taking into account the species distribution and the prevalence of resistance, cefepime, imipenem, amikacin and gentamicin appeared generally suitable for empirical therapeutic use in severe ICU-acquired Gram-negative infections in Belgium. However, the therapeutic strategy should be adapted according to the local ecology of resistance.
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46
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Mammeri H, Laurans G, Eveillard M, Castelain S, Eb F. Coexistence of SHV-4- and TEM-24-producing Enterobacter aerogenes strains before a large outbreak of TEM-24-producing strains in a French hospital. J Clin Microbiol 2001; 39:2184-90. [PMID: 11376055 PMCID: PMC88109 DOI: 10.1128/jcm.39.6.2184-2190.2001] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In 1996, a monitoring program was initiated at the teaching hospital of Amiens, France, and carried out for 3 years. All extended-spectrum beta-lactamase (ESBL)-producing Enterobacter aerogenes isolates recovered from clinical specimens were collected for investigation of their epidemiological relatedness by pulsed-field gel electrophoresis and enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) and determination of the type of ESBL harbored by isoelectric focusing and DNA sequencing. Molecular typing revealed the endemic coexistence, during the first 2 years, of two clones expressing, respectively, SHV-4 and TEM-24 ESBLs, while an outbreak of the TEM-24-producing strain raged in the hospital during the third year, causing the infection or colonization of 165 patients. Furthermore, this strain was identified as the prevalent clone responsible for outbreaks in many French hospitals since 1996. This study shows that TEM-24-producing E. aerogenes is an epidemic clone that is well established in the hospital's ecology and able to spread throughout wards. The management of the outbreak at the teaching hospital of Amiens, which included the reinforcement of infection control measures, failed to obtain complete eradication of the clone, which has become an endemic pathogen.
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Affiliation(s)
- H Mammeri
- Laboratory of Bacteriology-Hygiene, University Hospital Nord, 80054 Amiens Cédex 01, France.
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47
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Dé E, Baslé A, Jaquinod M, Saint N, Malléa M, Molle G, Pagès JM. A new mechanism of antibiotic resistance in Enterobacteriaceae induced by a structural modification of the major porin. Mol Microbiol 2001; 41:189-98. [PMID: 11454211 DOI: 10.1046/j.1365-2958.2001.02501.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Enterobacter aerogenes, multidrug resistance involves a decrease in outer membrane permeability associated with changes in an as yet uncharacterized porin. We purified the major porin from the wild-type strain and a resistant strain. We characterized this porin, which was found to be an OmpC/OmpF-like protein and analysed its pore-forming properties in lipid bilayers. The porin from the resistant strain was compared with the wild-type protein and we observed (i) that its single-channel conductance was 70% lower than that of the wild type; (ii) that it was three times more selective for cations; (iii) a lack of voltage sensitivity. These results indicate that the clinical strain is able to synthesize a modified porin that decreases the permeability of the outer membrane. Mass spectrometry experiments identified a G to D mutation in the putative loop 3 of the porin. Given the known importance of this loop in determining the pore properties of porins, we suggest that this mutation is responsible for the novel resistance mechanism developed by this clinical strain, with changes in porin channel function acting as a new bacterial strategy for controlling beta-lactam diffusion via porins.
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Affiliation(s)
- E Dé
- UMR 6522, CNRS, IFRMP 23, Faculté des Sciences, 76821 Mont-Saint-Aignan Cedex, France
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48
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De Gheldre Y, Struelens MJ, Glupczynski Y, De Mol P, Maes N, Nonhoff C, Chetoui H, Sion C, Ronveaux O, Vaneechoutte M. National epidemiologic surveys of Enterobacter aerogenes in Belgian hospitals from 1996 to 1998. J Clin Microbiol 2001; 39:889-96. [PMID: 11230400 PMCID: PMC87846 DOI: 10.1128/jcm.39.3.889-896.2001] [Citation(s) in RCA: 58] [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
Two national surveys were conducted to describe the incidence and prevalence of Enterobacter aerogenes in 21 Belgian hospitals in 1996 and 1997 and to characterize the genotypic diversity and the antimicrobial resistance profiles of clinical strains of E. aerogenes isolated from hospitalized patients in Belgium in 1997 and 1998. Twenty-nine hospitals collected 10 isolates of E. aerogenes, which were typed by arbitrarily primed PCR (AP-PCR) using two primers and pulsed-field gel electrophoresis. MICs of 10 antimicrobial agents were determined by the agar dilution method. Beta-lactamases were detected by the double-disk diffusion test and characterized by isoelectric point. The median incidence of E. aerogenes colonization or infection increased from 3.3 per 1,000 admissions in 1996 to 4.2 per 1000 admissions in the first half of 1997 (P < 0.01). E. aerogenes strains (n = 260) clustered in 25 AP-PCR types. Two major types, BE1 and BE2, included 36 and 38% of strains and were found in 21 and 25 hospitals, respectively. The BE1 type was indistinguishable from a previously described epidemic strain in France. Half of the strains produced an extended-spectrum beta-lactamase, either TEM-24 (in 86% of the strains) or TEM-3 (in 14% of the strains). Over 75% of the isolates were resistant to ceftazidime, piperacillin-tazobactam, and ciprofloxacin. Over 90% of the strains were susceptible to cefepime, carbapenems, and aminoglycosides. In conclusion, these data suggest a nationwide dissemination of two epidemic multiresistant E. aerogenes strains in Belgian hospitals. TEM-24 beta-lactamase was frequently harbored by one of these epidemic strains, which appeared to be genotypically related to a TEM-24-producing epidemic strain from France, suggesting international dissemination.
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Affiliation(s)
- Y De Gheldre
- Service de Microbiologie, Laboratoire de Bacteriologie, Université Libre de Bruxelles-Hôpital Erasme, 808 route de Lennik, 1070 Brussels, Belgium.
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49
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Abstract
Infection caused by organisms resistant to conventional antimicrobial therapy is an emerging problem of global proportions. This article describes the epidemiology of infections caused by resistant organisms in chronically critically ill patients and explores factors and mechanisms that lead to the development of resistance. Specific organisms and strategies for the treatment and control of these resistance organisms are discussed.
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Affiliation(s)
- D D Poutsiaka
- Division of Geographic Medicine and Infectious Diseases, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts, USA
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Berends BR, van den Bogaard AE, Van Knapen F, Snijders JM. Human health hazards associated with the administration of antimicrobials to slaughter animals. Part II. An assessment of the risks of resistant bacteria in pigs and pork. Vet Q 2001; 23:10-21. [PMID: 11205995 DOI: 10.1080/01652176.2001.9695069] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
Abstract
Risks for the consumer regarding the acquisition of resistant bacteria and/or resistance genes via the consumption of pork are discussed. In general, Salmonella spp. and Escherichia coli that originate from animals do not easily transfer their resistance genes to the resident intestinal flora of humans. The prevalence of resistant E. coli in humans seems more associated with being a vegetarian (odds ratio (OR) 1.89) than with the consumption of meat and meat products. Other risk factors are treatment with antimicrobials (OR 2-5), becoming hospitalized (OR 5.93), or working in a health setting (OR 4.38). In the Netherlands, annually an estimated 45,000 people (0-150,000) become a carrier of resistant E. coli and/or resistance genes that ori ginate from pigs, while an estimated 345,000 persons (175,000-600,000) become a carrier of resistant E. coli and/or resistance genes that originate from hospitals, e.g. other patients. Any problems with resistant Salmonella spp. that stem from pigs are, in fact, an integral part of the total problem of food-borne salmonellosis. Sometimes there are outbreaks of a specific multi-resistant clone of S. typhimurium that causes problems in both farm animals and humans. The probability that in the next 30 years there is no or maximally one outbreak of a specific clone that originates from pig herds is estimated at about 75%. Antimicrobials used as a growth promoter can have a measurable influence on the prevalence of resistant bacteria. The likely chain of events regarding avoparcin and the selection and dissemination of resistance against vancomycin in the enterococci gives the impression that the impact of the use of antimicrobials in animals on the prevalence of resistance in humans is largely determined by whether resistance genes are, or become, located on a self-transferable transposon. Furthermore, consumer health risks of antimicrobials used in slaughter pigs are mainly determined by the selection and dissemination of bacterial resistance and much less by the toxicological properties of any residues in pork. It is also concluded that most of the problems with resistant bacteria in humans are associated with the medical use of antimicrobials, and that the impact of particularly the veterinary use of antimicrobials is limited. However, the impact of antimicrobials used as a feed additive appears to be much greater than that of antimicrobials used for strictly veterinary purposes. The use of antimicrobials as a feed additive should therefore be seriously reconsidered.
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Affiliation(s)
- B R Berends
- Department of the Science of Food of Animal Origin, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
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