1
|
Schroeder TH, Hansen M, Stephan M, Hoffmann E, Unertl K, Krueger WA. Elimination of Linezolid by an in vitro Extracorporeal Circuit Model. Int J Artif Organs 2018; 27:473-9. [PMID: 15293354 DOI: 10.1177/039139880402700605] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Linezolid is an oxazolidinone antibiotic with activity against important grampositive aerobic bacteria, including nosocomial pathogens. It is not known whether dosage adjustments are necessary in patients treated with continuous renal replacement therapies. This in vitro study was conducted to investigate the elimination of linezolid in an in vitro continuous hemo(dia)filtration model using different filter materials (polysulfone, polyacrylonitrile, polyamide), surface areas, and different modes of renal replacement therapies. Linezolid was measured using HPLC with UV-detection. No adsorption of linezolid to any of the tested membranes was detected. Recovery of linezolid in the ultrafiltrate was 98.2 ± 10.5% in the filtration mode. During dialysis, recovery was significantly less (87.6 ± 16.1%; p = 0.02). Linezolid elimination was not altered by filter size, when polysulfone filters with surface areas of 0.7 m2 and 1.3 m2 were tested. In conclusion, the dosage recommendations for linezolid are independent of the filter materials. However, the elimination is significantly higher during hemofiltration compared to dialysis.
Collapse
Affiliation(s)
- T H Schroeder
- Department of Anesthesiology and Intensive Care Medicine, Tuebingen University Hospital, Tuebingen, Germany.
| | | | | | | | | | | |
Collapse
|
2
|
Mayers DL, Sobel JD, Ouellette M, Kaye KS, Marchaim D. Antibiotic Resistance of Non-pneumococcal Streptococci and Its Clinical Impact. ANTIMICROBIAL DRUG RESISTANCE 2017. [PMCID: PMC7123568 DOI: 10.1007/978-3-319-47266-9_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The taxonomy of streptococci has undergone major changes during the last two decades. The present classification is based on both phenotypic and genotypic data. Phylogenetic classification of streptococci is based on 16S rRNA sequences [1], and it forms the backbone of the overall classification system of streptococci. Phenotypic properties are also important, especially for clinical microbiologists. The type of hemolysis on blood agar, reaction with Lancefield grouping antisera, resistance to optochin, and bile solubility remain important for grouping of clinical Streptococcus isolates and therefore treatment options [2]. In the following chapter, two phenotypic classification groups, viridans group streptococci (VGS) and beta-hemolytic streptococci, will be discussed.
Collapse
Affiliation(s)
| | - Jack D. Sobel
- Wayne State University School of Medicine, Detroit Medical Center, Detroit, Michigan USA
| | - Marc Ouellette
- Canada Research Chair in Antimicrobial Resistance, Centre de recherche en Infectiologie, University of Laval, Quebec City, Canada
| | - Keith S. Kaye
- Division of Infectious Diseases, University of Michigan Medical School, Ann Arbor, Michigan USA
| | - Dror Marchaim
- Infection Control and Prevention Unit of Infectious Diseases, Assaf Harofeh Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| |
Collapse
|
3
|
Zhanel GG, Fontaine S, Adam H, Schurek K, Mayer M, Noreddin AM, Gin AS, Rubinstein E, Hoban DJ. A Review of New Fluoroquinolones : Focus on their Use in Respiratory Tract Infections. ACTA ACUST UNITED AC 2016; 5:437-65. [PMID: 17154673 DOI: 10.2165/00151829-200605060-00009] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The new respiratory fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, and on the horizon, garenoxacin) offer many improved qualities over older agents such as ciprofloxacin. These include retaining excellent activity against Gram-negative bacilli, with improved Gram-positive activity (including Streptococcus pneumoniae and Staphylococcus aureus). In addition, gatifloxacin, moxifloxacin and garenoxacin all demonstrate increased anaerobic activity (including activity against Bacteroides fragilis). The new fluoroquinolones possess greater bioavailability and longer serum half-lives compared with ciprofloxacin. The new fluoroquinolones allow for once-daily administration, which may improve patient adherence. The high bioavailability allows for rapid step down from intravenous administration to oral therapy, minimizing unnecessary hospitalization, which may decrease costs and improve quality of life of patients. Clinical trials involving the treatment of community-acquired respiratory infections (acute exacerbations of chronic bronchitis, acute sinusitis, and community-acquired pneumonia) demonstrate high bacterial eradication rates and clinical cure rates. In the treatment of community-acquired respiratory tract infections, the various new fluoroquinolones appear to be comparable to each other, but may be more effective than macrolide or cephalosporin-based regimens. However, additional data are required before it can be emphatically stated that the new fluoroquinolones as a class are responsible for better outcomes than comparators in community-acquired respiratory infections. Gemifloxacin (except for higher rates of hypersensitivity), levofloxacin, and moxifloxacin have relatively mild adverse effects that are more or less comparable to ciprofloxacin. In our opinion, gatifloxacin should not be used, due to glucose alterations which may be serious. Although all new fluoroquinolones react with metal ion-containing drugs (antacids), other drug interactions are relatively mild compared with ciprofloxacin. The new fluoroquinolones gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin have much to offer in terms of bacterial eradication, including activity against resistant respiratory pathogens such as penicillin-resistant, macrolide-resistant, and multidrug-resistant S. pneumoniae. However, ciprofloxacin-resistant organisms, including ciprofloxacin-resistant S. pneumoniae, are becoming more prevalent, thus prudent use must be exercised when prescribing these valuable agents.
Collapse
Affiliation(s)
- George G Zhanel
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, CanadaDepartment of Clinical Microbiology, Health Sciences Centre, Winnipeg, Manitoba, CanadaDepartment of Medicine, Health Sciences Centre, Winnipeg, Manitoba, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Ager S, Gould K. Clinical update on linezolid in the treatment of Gram-positive bacterial infections. Infect Drug Resist 2012; 5:87-102. [PMID: 22787406 PMCID: PMC3392139 DOI: 10.2147/idr.s25890] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Gram-positive pathogens are a significant cause of morbidity and mortality in both community and health care settings. Glycopeptides have traditionally been the antibiotics of choice for multiresistant Gram-positive pathogens but there are problems with their use, including the emergence of glycopeptide-resistant strains, tissue penetration, and achieving and monitoring adequate serum levels. Newer antibiotics such as linezolid, a synthetic oxazolidinone, are available for the treatment of resistant Gram-positive bacteria. Linezolid is active against a wide range of Gram-positive bacteria and has been generally available for the treatment of Gram-positive infections since 2000. There are potential problems with linezolid use, including its bacteriostatic action and the relatively high incidence of reported adverse effects, particularly with long-term use. Long-term use may also be complicated by the development of resistance. However, linezolid has been shown to be clinically useful in the treatment of several serious infections where traditionally bacteriocidal agents have been required and many of its adverse effects are reversible on cessation. It has also been shown to be a cost-effective treatment option in several studies, with its high oral bioavailability allowing an early change from intravenous to oral formulations with consequent earlier patient discharge and lower inpatient costs.
Collapse
Affiliation(s)
- Sally Ager
- Department of Microbiology, Newcastle upon Tyne Hospitals Trust, Freeman Hospital, High Heaton, Newcastle upon Tyne, UK
| | | |
Collapse
|
5
|
Does linezolid modulate lung innate immunity in a murine model of methicillin-resistant Staphylococcus aureus pneumonia? Crit Care Med 2011; 39:1944-52. [PMID: 21532475 DOI: 10.1097/ccm.0b013e31821bd79e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Methicillin-resistant Staphylococcus aureus is an important cause of mortality among nosocomial infections. Recent investigations suggest that linezolid is superior to vancomycin in achieving clinical cure in patients with nosocomial pneumonia. We hypothesized that linezolid may exhibit anti-inflammatory properties in vivo model of pneumonia. DESIGN Prospective interventional study. SETTING University affiliated laboratory. SUBJECTS BALB/c mice. INTERVENTIONS Three groups of BALB/c mice were inoculated with methicillin-resistant S. aureus American Type Culture Collection 33,591 to induce pneumonia. Each group (n = 6) underwent bronchoalveolar lavage at 24 hrs, 48 hrs, and 72 hrs after inoculation after treatment with vancomycin, linezolid, or no antibiotic. Bronchoalveolar lavage fluid levels of monocyte chemotactic protein-5 and interleukin-6 were quantified using cytometric bead array. Metalloproteinase-9 was detected by enzyme-linked immunosorbent assay and gelatin zymography. Neutrophil apoptosis in bronchoalveolar lavage was assessed by annexin V and 7-aminoactinomycin D staining. Neutrophil activity was determined by myeloperoxidase enzyme activity. Phagocytosis of apoptotic neutrophils by linezolid- vs. vancomycin treated-alveolar macrophages was examined in vitro. MEASUREMENTS AND MAIN RESULTS Infected mice had a significant reduction in lung bacterial titers compared with controls (p < .05) after treatment with linezolid or vancomycin. There was no difference in bronchoalveolar lavage levels of monocyte chemotactic protein-5 or interleukin-6 between vancomycin- and linezolid-treated groups. Both antimicrobials were comparable in modulating the expression of matrix metalloproteinase-9 in bronchoalveolar lavage. Neutrophil apoptosis was comparable in both vancomycin- and linezolid-treated groups at all three time points. Vancomycin showed lower myeloperoxidase activity compared with linezolid in the first 24 hrs after inoculation (p = .03), but the difference was undetectable at 48 hrs and 72 hrs. Neither compound had an impact on the process of removal of apoptotic neutrophils by alveolar macrophages. CONCLUSIONS Linezolid did not display an advantage over vancomycin in modulating pulmonary innate immune response in a murine model of methicillin-resistant S. aureus pneumonia.
Collapse
|
6
|
Immunoasssay chromatographic antigen test for rapid diagnosis of Group A beta hemolytic Streptococcus pharyngitis in children: A cross/ sectional study. IRANIAN JOURNAL OF MICROBIOLOGY 2011; 3:99-103. [PMID: 22347590 PMCID: PMC3279809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND AND OBJECTIVE Group A beta-hemolytic streptococcus (GABHS) is an important pharyngotonsillitis etiologic agent in children. The objective of this study was diagnosis of streptococcal pharyngitis based on rapid antigen detection test and conventional pharyngeal culture. MATERIALS AND METHODS The rapid GABHS antigen detection test was compared to culture on blood agar, the gold standard for the diagnosis of this etiologic agent. RESULTS Streptococcal antigen was detected in pharyngeal specimens of 34.5% of cases by rapid strip test. We detected group A Streptococcus in 17.2% of pharyngeal culture. There was no agreement between two methods ( PV < 0.1). The negative pharyngeal culture results are probably due to antibiotic usage in 43.2% of patients. Positive rapid test results in pharyngeal swab was age dependent ( P < 0.05). There was good correlation between observing the "petechia in pharynx of patients" and positive rapid test in pharyngeal swab (P < 0.004). Throat culture results were relatated to previous antibiotic usage ( P < 0.03). CONCLUSION The rapid test in pharyngeal swab is helpful for rapid diagnosis and treatment of GABHS pharyngitis. Diagnosis of GABHS pharyngitis based on soley clinical findings is misleading in the majority of cases. Petechia observed in pharynx of the cases was highly predictive of streptococcal pharyngitis.
Collapse
|
7
|
Antibiotic Resistance of Non-Pneumococcal Streptococci and Its Clinical Impact. ANTIMICROBIAL DRUG RESISTANCE 2009. [PMCID: PMC7122742 DOI: 10.1007/978-1-60327-595-8_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Viridans streptococci (VGS) form a phylogenetically heterogeneous group of species belonging to the genus Streptococcus (1). However, they have some common phenotypic properties. They are alfa- or non-haemolytic. They can be differentiated from S. pneumoniae by resistance to optochin and the lack of bile solubility (2). They can be differentiated from the Enterococcus species by their inability to grow in a medium containing 6.5% sodium chloride (2). Earlier, so-called nutritionally variant streptococci were included in the VGS but based on the molecular data they have now been removed to a new genus Abiotrophia (3) and are not included in the discussion below. VGS belong to the normal microbiota of the oral cavities and upper respiratory tracts of humans and animals. They can also be isolated from the female genital tract and all regions of the gastrointestinal tract (2, 3). Several species are included in VGS and are listed elsewhere (2, 3). Clinically the most important species belonging to the VGS are S. mitis, S. sanguis and S. oralis.
Collapse
|
8
|
Genetic elements responsible for erythromycin resistance in streptococci. Antimicrob Agents Chemother 2008; 53:343-53. [PMID: 19001115 DOI: 10.1128/aac.00781-08] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
9
|
Lambertsen L, Ekelund K, Hansen DS, Kaltoft M, Christensen JJ, Hammerum AM. Erythromycin resistance caused by erm(A) subclass erm(TR) in a Danish invasive pneumococcal isolate: are erm(A) pneumococcal isolates overlooked? ACTA ACUST UNITED AC 2008; 40:584-7. [PMID: 18584554 DOI: 10.1080/00365540701854717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Erm(A) is rarely reported as erythromycin resistance determinant in pneumococci. One invasive erm(A) isolate was initially tested intermediate erythromycin resistant using E-test. However, upon re-testing it was resistant, thus close to the breakpoint value. This may be a reason why erm(A) only rarely is reported to cause resistance in pneumococci.
Collapse
Affiliation(s)
- Lotte Lambertsen
- Neisseria and Streptococcus Reference, Department for Bacteriology, Mycology and Parasitology, Statens Serum Institute, Copenhagen, Denmark.
| | | | | | | | | | | |
Collapse
|
10
|
New genetic element carrying the erythromycin resistance determinant erm(TR) in Streptococcus pneumoniae. Antimicrob Agents Chemother 2007; 52:619-25. [PMID: 18070957 DOI: 10.1128/aac.01081-07] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
erm(A) subclass erm(TR), a common macrolide resistance determinant in Streptococcus pyogenes but quite rare in Streptococcus pneumoniae, was found in a clinical S. pneumoniae isolate (AP200) from Italy. In this isolate, erm(TR) was found included in a genetic element approximately 56 kb in size that did not appear to be conjugative but could be transferred by transformation. An erm(TR)-containing DNA fragment of approximately 10 kb was sequenced and 12 open reading frames (ORFs) were identified. Upstream of erm(TR), a regulatory protein of the TetR family and the two components of an efflux pump of the ABC type were found. Downstream of erm(TR), there were ORFs homologous to a spectinomycin phosphotransferase, transposases, and a relaxase. Since the genomic sequence of S. pyogenes MGAS10750 carrying erm(TR) became available, comparison between the erm(TR)-containing genetic elements in AP200 and in MGAS10750 was performed. The region flanking erm(TR) in MGAS10750 showed identity with AP200 for 10 ORFs out of 12. PCR mapping using primers designed on the sequence of MGAS10750 confirmed that AP200 carries a genetic element similar to that of MGAS10750. In AP200 the genetic element was inserted inside an ORF homologous to spr0790 of S. pneumoniae R6, coding for a type I restriction modification system. Homologies between the insertion sites in AP200 and MGAS10750 consisted of eight conserved nucleotides, of which three were duplicated, likely representing target site duplication. The structure of the erm(TR)-carrying genetic element shows characteristics of a transposon/prophage remnant chimera. In AP200 this genetic element was designated Tn1806.
Collapse
|
11
|
ABD EL-ATY AM, GOUDAH A, SHAH SS, SHIN HC, SHIMODA M, SHIM JH. Pharmacokinetic variables of moxifloxacin in healthy male camels following intravenous and intramuscular administration. J Vet Pharmacol Ther 2007; 30:586-91. [DOI: 10.1111/j.1365-2885.2007.00908.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
12
|
Betriu C, Rodríguez-Avial I, Gómez M, Culebras E, López F, Alvarez J, Picazo JJ. Antimicrobial activity of tigecycline against clinical isolates from Spanish medical centers. Second multicenter study. Diagn Microbiol Infect Dis 2006; 56:437-44. [PMID: 16949245 DOI: 10.1016/j.diagmicrobio.2006.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 07/02/2006] [Accepted: 07/10/2006] [Indexed: 11/27/2022]
Abstract
The antimicrobial activity of tigecycline, a novel glycylcycline, was evaluated against 1102 bacterial isolates from 20 centers in Spain. The MIC of tigecycline at which 90% (MIC(90)) of the pneumococci tested were inhibited was the lowest (0.06 microg/mL) of all the antibiotics tested. The MICs of tigecycline against enterococci ranged from 0.03 to 0.125 microg/mL. All staphylococci were inhibited by < or =0.25 microg/mL of tigecycline, and 99.6% of Enterobacteriaceae isolates were inhibited by < or =2 microg/mL of tigecycline. Tigecycline demonstrated good activity against Bacteroides fragilis group organisms with an MIC(90) of 4 microg/mL. The results of this study confirm the excellent activity of tigecycline against multiresistant Gram-positive and Gram-negative pathogens.
Collapse
Affiliation(s)
- Carmen Betriu
- Department of Clinical Microbiology, Hospital Clínico San Carlos, 28040 Madrid, Spain
| | | | | | | | | | | | | |
Collapse
|
13
|
Gosbell IB, Fernandes LA, Fernandes CJ. In vitro antibacterial activity of beta-lactams and non-beta-lactams against Streptococcus pneumoniae isolates from Sydney, Australia. Pathology 2006; 38:343-8. [PMID: 16916725 DOI: 10.1080/00313020600820732] [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: 10/24/2022]
Abstract
AIMS This study was undertaken to determine the antimicrobial resistance patterns of strains of Streptococcus pneumoniae from Sydney, Australia, comparing penicillin-susceptible, -intermediate and -resistant isolates. METHODS Non-duplicate cultures of S. pneumoniae were collected from 1 January to 31 December 2002 in the three penicillin-susceptibility categories. Minimum inhibitory concentrations (MICs) of 19 antibacterial agents were determined by agar dilution based on the National Committee for Clinical Laboratory Standards (NCCLS) methodology. Overall for 2002, 687 non-duplicate isolates were obtained, of which 190 (28%) were intermediate or resistant to penicillin. From this set, 183 isolates were selected for study: 88 (48%) in the penicillin-susceptible group (MIC <or= 0.06 mg/L), 25 (14%) in the penicillin-intermediate group (MIC 0.125-1.0 mg/L) and 70 (38%) in the penicillin-resistant group (MIC >or= 2.0 mg/L). RESULTS Resistance to non-beta-lactams was more common in penicillin-intermediate or -resistant strains. Multidrug resistance (resistance to >or= 2 non-beta-lactams) was found in 3% of penicillin-susceptible, 52% of penicillin-intermediate and 87% of penicillin-resistant isolates. Erythromycin resistance was seen in 22% of the penicillin-susceptible strains but increased significantly to 60% and 89% in the penicillin-intermediate and resistant strains, respectively. Clindamycin, tetracycline and trimethoprim/sulfamethoxazole showed similar diminished activity in penicillin-intermediate and -resistant strains; 64, 84 and 91% of the penicillin-resistant isolates were resistant to clindamycin, tetracycline and to trimethoprim/sulfamethoxazole, respectively. Chloramphenicol resistance was comparatively low level except 19% of the penicillin-resistant strains were resistant. Ciprofloxacin MICs for 14 strains were raised (MICs 4-16 mg/L); three of these were penicillin-susceptible, one penicillin-intermediate and 10 penicillin-resistant. Only one isolate was resistant to moxifloxacin and to gatifloxacin. Resistance to rifampicin, vancomycin, oritavancin, or linezolid was not detected. Twenty-three isolates were intermediate and one resistant to quinupristin/dalfopristin - 22 of these were penicillin resistant. CONCLUSIONS Streptococcus pneumoniae isolates from Sydney are commonly resistant to beta-lactams and available non-beta-lactam agents, especially if they are penicillin non-susceptible. Resistance to moxifloxacin and gatifloxacin is still rare, but some isolates were non-susceptible to quinupristin/dalfopristin. It is important to continue to survey resistance patterns to recognise emerging resistances which affect the selection of empirical antimicrobials to treat infections with S. pneumoniae.
Collapse
Affiliation(s)
- Iain B Gosbell
- Department of Microbiology, South Western Area Pathology Service, Liverpool, Australia.
| | | | | |
Collapse
|
14
|
Dobay O, Rozgonyi F, Amyes SGB. Molecular characterisation of Hungarian macrolide-resistant Streptococcus pneumoniae isolates, including three highly resistant strains with the mef gene. Int J Antimicrob Agents 2005; 25:488-95. [PMID: 15878263 DOI: 10.1016/j.ijantimicag.2005.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Accepted: 02/09/2005] [Indexed: 10/25/2022]
Abstract
The macrolide resistance of 304 Hungarian Streptococcus pneumoniae isolates was investigated. Antibiotic sensitivity testing was performed in air and in 5% CO(2). More erythromycin resistance was noted when growth was in CO(2). A resistance determinant was found in almost all isolates: erm(B) gene (87.4%), mef genes (9.2%) and one strain with the erm(TR) gene. This indicates that screening for carriage of resistance determinants should always be done in the presence of 5% CO(2). We found three isolates with mef(E), which were highly resistant to erythromycin. These contained multiple and some novel, ribosomal mutations. The most prevalent serogroups were 6, 19 and 14. Based on the PFGE pattern, we found identity between the Hungarian isolates and two PMEN clones.
Collapse
Affiliation(s)
- Orsolya Dobay
- Medical Microbiology, Medical School, University of Edinburgh, Teviot Place, Edinburgh EH8 9AG, Scotland, UK
| | | | | |
Collapse
|
15
|
Kim NJ, Park SJ, Choi SH, Lee MS, Choo EJ, Kwak YG, Woo JH, Ryu J, Jeong JY, Kim YS. Characterization of Erythromycin-ResistantStreptococcus pneumoniaein Korea, andIn VitroActivity of Telithromycin against Erythromycin-ResistantStreptococcus pneumoniae. Microb Drug Resist 2005; 11:260-5. [PMID: 16201929 DOI: 10.1089/mdr.2005.11.260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To characterize the phenotypes and genotypes of erythromycin-resistant clinical isolates of Streptococcus pneumoniae in Korea and to evaluate the in vitro activity of telithromycin against these erythromycin-resistant isolates, we tested a total of 676 isolates of S. pneumoniae collected from 1997 to 2002 in a tertiary hospital in Seoul, Republic of Korea. MICs for erythromycin and telithromycin were determined by the agar dilution method. The macrolide resistance phenotypes of erythromycin-resistant isolates were determined by the erythromycin- clindamycin-rokitamycin triple disk (ECRTD) and MIC induction tests, whereas their macrolide resistance genotypes were determined by PCR for the erm(B), erm(A), subclass erm(TR), and mef genes. To discriminate between mef(A) and mef(E), PCR-restriction fragment length polymorphism (RFLP) analyses were performed. Of the 676 S. pneumoniae isolates, 459 (67.9%) were resistant to erythromycin. Of the 459 erythromycin-resistant isolates, 343 (74.7%) were assigned to the cMLS phenotype, 48 (10.4%) to the iMcLS phenotype, 4 (0.9%) to the iMLS phenotype, and 64 (14.0%) to the M phenotype. The erm(B) gene was detected in 251 (54.6%) isolates, the mef gene was detected in 64 (14.0%), and both the erm(B) and mef genes were detected in 144 (31.4%) isolates. All of the mef genes detected were identified as mef(E). Of the 459 erythromycin- resistant isolates, all but one were susceptible to telithromycin. The MIC(50)/MIC(90) to telithromycin of isolates carrying erm(B), mef(E), and both genes was 0.06/0.5 microg/ml, 0.03/0.125 microg/ml, and 0.5/1.0 microg/ml, respectively. Although the MICs of telithromycin for the erythromycin-resistant isolates varied according to genotype, telithromycin was very active against these erythromycin-resistant S. pneumoniae.
Collapse
Affiliation(s)
- Nam Joong Kim
- Division of Infectious Disease, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Van Eldere J, Meekers E, Lagrou K, Massonet C, Canu A, Devenyns I, Verhaegen J, Syrogiannopoulos G, Leclercq R. Macrolide-resistance mechanisms in Streptococcus pneumoniae isolates from Belgium. Clin Microbiol Infect 2005; 11:332-4. [PMID: 15760433 DOI: 10.1111/j.1469-0691.2005.01077.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Of 233 erythromycin-resistant pneumococcal isolates collected in Belgium in 1999-2000, 89.7% carried the erm(B) gene, 6% the mef(A) gene, and 3.5%erm(B) plus mef(A). Two isolates contained neither erm(B) nor mef(A); one contained an erm(A) subclass erm(TR) gene, while the other contained an A2058G mutation in domain V of the 23S rRNA gene. Of 209 erm(B)-positive isolates, 191 had clindamycin MICs > 16 mg/L and 18 had MICs < or = 16 mg/L. Mef(A)-positive isolates all displayed the M resistance phenotype. Telithromycin remained active against erythromycin-resistant isolates, with the highest telithromycin MIC50 being found in mef(A)-positive isolates. No difference in the prevalence of different resistance mechanisms was observed compared to isolates collected in 1995-1997.
Collapse
Affiliation(s)
- J Van Eldere
- Department of Microbiology and Immunology, Katholieke Universiteit Leuven, Leuven, Belgium.
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
Moxifloxacin (Avelox) is a fluoroquinolone antibacterial with a methoxy group in the C-8 position and a bulky C-7 side chain. Moxifloxacin is approved for use in the treatment of acute exacerbations of chronic bronchitis (AECB), community-acquired pneumonia (CAP), acute bacterial sinusitis and uncomplicated skin and skin structure infections (approved indications may differ between countries). Moxifloxacin has a broad spectrum of antibacterial activity, including activity against penicillin-resistant Streptococcus pneumoniae. It achieves good tissue penetration and has a convenient once-daily administration schedule, as well as being available in both intravenous and oral formulations in some markets. Moxifloxacin has good efficacy in the treatment of patients with AECB, CAP, acute bacterial sinusitis and uncomplicated skin and skin structure infections, and is generally well tolerated. Thus, moxifloxacin is an important option in the treatment of bacterial infections.
Collapse
|
18
|
Tiemei Z, Xiangqun F, Youning L. Resistance phenotypes and genotypes of erythromycin-resistant Streptococcus pneumoniae isolates in Beijing and Shenyang, China. Antimicrob Agents Chemother 2004; 48:4040-1. [PMID: 15388475 PMCID: PMC521870 DOI: 10.1128/aac.48.10.4040-4041.2004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2004] [Revised: 04/13/2004] [Accepted: 06/21/2004] [Indexed: 11/20/2022] Open
Abstract
Of a total of 192 Streptococcus pneumoniae isolates, 149 (77.6%) were not susceptible to erythromycin. Of these 149 isolates, 117 (79.1%) contained the erm(B) gene, 16 (10.8%) contained the mef(A) gene, and 15 (10.1%) harbored both the erm(B) and mef(A) genes.
Collapse
Affiliation(s)
- Zhao Tiemei
- Department of Respiratory Diseases, Chinese PLA General Hospital, Beijing 100853, People's Republic of China
| | | | | |
Collapse
|
19
|
Cerdá Zolezzi P, Rubio Calvo MC, Millán L, Goñi P, Canales M, Capilla S, Durán E, Gómez-Lus R. Macrolide resistance phenotypes of commensal viridans group streptococci and Gemella spp. and PCR detection of resistance genes. Int J Antimicrob Agents 2004; 23:582-9. [PMID: 15194129 DOI: 10.1016/j.ijantimicag.2003.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2003] [Accepted: 10/29/2003] [Indexed: 11/23/2022]
Abstract
One hundred and sixty viridans group streptococci (VGS) and 26 Gemella spp. resistant to erythromycin were studied to detect macrolide lincosamide and streptogramin B (MLS(B)) phenotypes and to investigate resistance rates to other antibiotics. The M phenotype was most prevalent in both bacterial groups (59.6% in VGS, 69.2% in gemellae) and the iMLS(B) phenotype was found least often (9.3 and 13.9%, respectively). All isolates with M phenotype had the mef(A/E) gene, being prevalent the mef(E) subclass. cMLS(B) and iMLS(B) strains contained the erm(B) gene, alone or in combination with the mef(A/E) gene. Thirteen isolates were intermediately resistant to quinupristin/dalfopristin and 11 strains showed low susceptibility to telithromycin. Linezolid was active against all the isolates tested and tetracycline resistance was the major one in VGS (41.6%) and Gemella spp. (46.2%).
Collapse
Affiliation(s)
- P Cerdá Zolezzi
- Department of Microbiology, Faculty of Medicine, Clinical University Hospital "Lozano Blesa", University of Zaragoza, c/Domingo Miral s/n, 50009 Zaragoza, Spain
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Muller-Serieys C, Drugeon HB, Etienne J, Lascols C, Leclercq R, Nguyen J, Soussy CJ. Activity of linezolid against Gram-positive cocci isolated in French hospitals as determined by three in-vitro susceptibility testing methods. Clin Microbiol Infect 2004; 10:242-6. [PMID: 15008946 DOI: 10.1111/j.1198-743x.2004.00751.x] [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: 11/30/2022]
Abstract
In total, 844 strains of Gram-positive cocci were collected from six university hospitals in France between September 1999 and January 2000. MICs of linezolid were determined: (i) for all strains by agar dilution (method A); (ii) by broth microdilution (method B) for staphylococci and enterococci; (iii) by Etest (method E) for beta-haemolytic streptococci and Streptococcus pneumoniae. Susceptibility to other antibiotics was determined by the disk diffusion method. MIC50 and MIC90 values were identical (2 mg/L) for methicillin-susceptible Staphylococcus aureus (n = 179) by methods A and B. Linezolid was active against methicillin-resistant S. aureus (n = 117), with an MIC90 of 2 mg/L (methods A and B), but with a lower MIC50 of 1 mg/L by method A. Of the 200 coagulase-negative staphylococci, 56.5% were methicillin-resistant and 43.5% were methicillin-susceptible. Linezolid had similar in-vitro activity by methods A and B (MIC50 and MIC90 values of 1-2 mg/L), irrespective of methicillin susceptibility. The MIC90 of linezolid for all enterococci (150 Enterococcus faecalis and 50 Enterococcus faecium) was 2 mg/L by both methods. MICs of linezolid for beta-haemolytic streptococci had a narrow range of 0.5-2 mg/L (method A) and 0.125-2 mg/L (method E). Pneumococci (n = 118), including 67 penicillin G-intermediate and -resistant strains, were all inhibited by linezolid 2 mg/L (MIC90 of 2 mg/L by methods A and E). No strain had an MIC of > 2 mg/L by agar dilution or Etest, or of > 4 mg/L by broth microdilution. Overall, the study confirmed the good in-vitro activity of linezolid and the very narrow range of MICs for Gram-positive cocci susceptible or resistant to other antibiotics, irrespective of the method used.
Collapse
Affiliation(s)
- C Muller-Serieys
- Laboratoire de Bactériologie, Groupe Hospitalier Bichat-Claide Bernard, Paris, France.
| | | | | | | | | | | | | |
Collapse
|
21
|
Virulence factors, antibiotic resistance mechanisms and the prevalence of resistance worldwide in Streptococcus pneumoniae. ACTA ACUST UNITED AC 2004. [DOI: 10.1097/01.revmedmi.0000131429.20976.8f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
22
|
Montanari MP, Cochetti I, Mingoia M, Varaldo PE. Phenotypic and molecular characterization of tetracycline- and erythromycin-resistant strains of Streptococcus pneumoniae. Antimicrob Agents Chemother 2003; 47:2236-41. [PMID: 12821474 PMCID: PMC161878 DOI: 10.1128/aac.47.7.2236-2241.2003] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sixty-five clinical isolates of Streptococcus pneumoniae, all collected in Italy between 1999 and 2002 and resistant to both tetracycline (MIC, >or=8 microg/ml) and erythromycin (MIC, >or=1 microg/ml), were investigated. Of these strains, 11% were penicillin resistant and 23% were penicillin intermediate. With the use of the erythromycin-clindamycin-rokitamycin triple-disk test, 14 strains were assigned to the constitutive (cMLS) phenotype of macrolide resistance, 44 were assigned to the partially inducible (iMcLS) phenotype, 1 was assigned to the inducible (iMLS) phenotype, and 6 were assigned to the efflux-mediated (M) phenotype. In PCR assays, 64 of the 65 strains were positive for the tetracycline resistance gene tet(M), the exception being the one M isolate susceptible to kanamycin, whereas tet(K), tet(L), and tet(O) were never found. All cMLS, iMcLS, and iMLS isolates had the erythromycin resistance gene erm(B), and all M phenotype isolates had the mef(A) or mef(E) gene. No isolate had the erm(A) gene. The int-Tn gene, encoding the integrase of the Tn916-Tn1545 family of conjugative transposons, was detected in 62 of the 65 test strains. Typing assays showed the strains to be to a great extent unrelated. Of 16 different serotypes detected, the most numerous were 23F (n = 13), 19A (n = 10), 19F (n = 9), 6B (n = 8), and 14 (n = 6). Of 49 different pulsed-field gel electrophoresis types identified, the majority (n = 39) were represented by a single isolate, while the most numerous type included five isolates. By high-resolution restriction analysis of PCR amplicons with four endonucleases, the tet(M) loci from the 64 tet(M)-positive pneumococci were classified into seven distinct restriction types. Overall, a Tn1545-like transposon could reasonably account for tetracycline and erythromycin resistance in the vast majority of the pneumococci of cMLS, iMcLS, and iMLS phenotypes, whereas a Tn916-like transposon could account for tetracycline resistance in most M phenotype strains.
Collapse
Affiliation(s)
- Maria P Montanari
- Department of Microbiology and Biomedical Sciences, University of Ancona Medical School, 60131 Ancona, Italy
| | | | | | | |
Collapse
|
23
|
Butler JC, Lennox JL, McDougal LK, Sutcliffe JA, Tait-Kamradt A, Tenover FC. Macrolide-resistant pneumococcal endocarditis and epidural abscess that develop during erythromycin therapy. Clin Infect Dis 2003; 36:e19-25. [PMID: 12522763 DOI: 10.1086/344965] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2002] [Accepted: 09/12/2002] [Indexed: 11/04/2022] Open
Abstract
Suppurative complications of Streptococcus pneumoniae infections have become uncommon in the antibiotic era. We report a case of pneumococcal bacteremia and pneumonia complicated with epidural abscess and endocarditis in which macrolide resistance (the MLS(B) phenotype) emerged during erythromycin therapy. Genetic determinants known to mediate the most common mechanisms of macrolide resistance (methylation of the 23S rRNA and antibiotic efflux) were not detected by polymerase chain reaction or DNA hybridization. Sequence analysis of the DNA encoding the 23S rRNA of the macrolide-resistant isolate from the patient demonstrated the replacement of adenine by thymine at position 2058 (A2058T) in 2 of 4 alleles. Clinicians should be alert to the possibility of the emergence of resistance during macrolide therapy for community-acquired pneumonia, particularly if suppurative complications of pneumococcal infection are suspected.
Collapse
Affiliation(s)
- Jay C Butler
- Arctic Investigations Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, Alaska 99508, USA.
| | | | | | | | | | | |
Collapse
|
24
|
Montanari MP, Mingoia M, Cochetti I, Varaldo PE. Phenotypes and genotypes of erythromycin-resistant pneumococci in Italy. J Clin Microbiol 2003; 41:428-31. [PMID: 12517885 PMCID: PMC149635 DOI: 10.1128/jcm.41.1.428-431.2003] [Citation(s) in RCA: 52] [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
Of 120 erythromycin-resistant pneumococci isolated in Italian hospitals, 39 (32.5%) were M-type isolates, carrying the mef gene alone. The mef gene was also detected, together with erm(AM), in one constitutively resistant isolate and in five isolates of the partially inducible phenotype. Among the 45 mef-positive isolates, 25 (55.6%) carried mef(A) and 20 (44.4%) carried mef(E) as observed from PCR-restriction fragment length polymorphism analysis of a 1,743-bp amplicon. The same result was obtained by a similar method applied to a more common 348-bp amplicon.
Collapse
Affiliation(s)
- Maria Pia Montanari
- Department of Microbiology and Biomedical Sciences, University of Ancona Medical School, 60131 Ancona, Italy
| | | | | | | |
Collapse
|
25
|
Carmona PM, Romá E, Monte E, García J, Gobernado M. [Role of linezolid in antimicrobial therapy]. Enferm Infecc Microbiol Clin 2003; 21:30-41. [PMID: 12550042 DOI: 10.1016/s0213-005x(03)72872-9] [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: 10/27/2022]
Abstract
The progressive emergence of multi-resistant gram-positive strains has prompted the search for new molecules (quinolones, streptogramins, oxazolidinones, ketolides, glycopeptides, daptomycin) to add to the current therapeutic arsenal. Linezolid, the first commercially available member of the oxazolidinone family, has evidenced activity against multi-resistant gram-positive strains (methicillin-resistant Staphylococcus aureus, S. aureus with decreased glycopeptide sensitivity, vancomycin-resistant Enterococcus spp., Streptococcus pneumoniae with decreased sensitivity to penicillin and cephalosporins), thereby providing a new option for treating infections by these microorganisms. This work reviews the microbiologic and pharmacologic aspects of this agent in order to establish its position among the available options for antimicrobial chemotherapy.
Collapse
|
26
|
Leclercq R, Courvalin P. Resistance to macrolides and related antibiotics in Streptococcus pneumoniae. Antimicrob Agents Chemother 2002; 46:2727-34. [PMID: 12183222 PMCID: PMC127415 DOI: 10.1128/aac.46.9.2727-2734.2002] [Citation(s) in RCA: 168] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
27
|
Odenholt I, Löwdin E, Gustafsson I, Cars O. Pharmacodynamics of moxifloxacin against Streptococcus pyogenes in an in vitro kinetic model. Antimicrob Agents Chemother 2002; 46:2046-8. [PMID: 12019138 PMCID: PMC127214 DOI: 10.1128/aac.46.6.2046-2048.2002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aim of the present study was to investigate the pharmacodynamics of moxifloxacin against strains of Streptococcus pyogenes with different susceptibilities to erythromycin by using an in vitro kinetic model simulating human pharmacokinetics of moxifloxacin at oral doses of 400 and 200 mg, respectively. When the different strains of S. pyogenes were exposed to the higher dose, the number of bacteria was reduced below the detection limit after 12 h and no regrowth was noted during the following 12 h. At the lower dose there was regrowth of the strains with constitutive and inducible erythromycin resistance of the MLS(B) phenotype. Replication assays of the regrowing bacteria indicated that the failure of moxifloxacin to kill the MLS(B) strains at the lower dose was likely caused by the emergence of preexisting resistant subpopulations. Thus, the present study indicates that the presently used 400-mg dose seems to have an advantage over the lower dose in that the risk for selection of resistant subpopulations is minimized.
Collapse
Affiliation(s)
- Inga Odenholt
- Antibiotic Research Unit, Department of Infectious Diseases and Clinical Microbiology, University Hospital, Uppsala, Sweden.
| | | | | | | |
Collapse
|
28
|
Conte JE, Golden JA, Kipps J, Zurlinden E. Intrapulmonary pharmacokinetics of linezolid. Antimicrob Agents Chemother 2002; 46:1475-80. [PMID: 11959585 PMCID: PMC127139 DOI: 10.1128/aac.46.5.1475-1480.2002] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, our objective was to determine the steady-state intrapulmonary concentrations and pharmacokinetic parameters of orally administered linezolid in healthy volunteers. Linezolid (600 mg every 12 h for a total of five doses) was administered orally to 25 healthy adult male subjects. Each subgroup contained five subjects, who underwent bronchoscopy and bronchoalveolar lavage (BAL) 4, 8, 12, 24, or 48 h after administration of the last dose. Blood was obtained for drug assay prior to administration of the first dose and fifth dose and at the completion of bronchoscopy and BAL. Standardized bronchoscopy was performed without systemic sedation. The volume of epithelial lining fluid (ELF) recovered was calculated by the urea dilution method, and the total number of alveolar cells (AC) was counted in a hemocytometer after cytocentrifugation. Linezolid was measured in plasma by a high-pressure liquid chromatography (HPLC) technique and in BAL specimens and AC by a combined HPLC-mass spectrometry technique. Areas under the concentration-time curves (AUCs) for linezolid in plasma, ELF, and AC were derived by noncompartmental analysis. Half-lives for linezolid in plasma, ELF, and AC were calculated from the elimination rate constants derived from a monoexponential fit of the means of the observed concentrations at each time point. Concentrations (means +/- standard deviations) in plasma, ELF, and AC, respectively, were 7.3 +/- 4.9, 64.3 +/- 33.1, and 2.2 +/- 0.6 microg/ml at the 4-h BAL time point and 7.6 +/- 1.7, 24.3 +/- 13.3, and 1.4 +/- 1.3 microg/ml at the 12-h BAL time point. Linezolid concentrations in plasma, ELF, and AC declined monoexponentially, with half-lives of 6.9, 7.0, and 5.7 h, respectively. For a MIC of 4, the 12-h plasma AUC/MIC and maximum concentration/MIC ratios were 34.6 and 3.9, respectively, and the percentage of time the drug remained above the MIC for the 12-h dosing interval was 100%; the corresponding ratios in ELF were 120 and 16.1, respectively, and the percentage of time the drug remained above the MIC was 100%. The long plasma and intrapulmonary linezolid half-lives and the percentage of time spent above the MIC of 100% of the dosing interval provide a pharmacokinetic rationale for drug administration every 12 h and indicate that linezolid is likely to be an effective agent for the treatment of pulmonary infections.
Collapse
Affiliation(s)
- John E Conte
- Infectious Diseases Research Group, Department of Epidemiology & Biostatistics, University of California, San Francisco, San Francisco, California 94143-0919, USA.
| | | | | | | |
Collapse
|
29
|
Abstract
The oxazolidinones are a new chemical class of synthetic antmicrobials characterized by a unique mechanism of protein synthesis inhibition. Linezolid is the first compound of this class and has recently received approval for the treatment of community- and hospital-acquired pneumonia and skin and skin structure infections. In vitro tests demonstrate that linezolid possesses a significant activity against Gram-positive pathogens including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), vancomycin-intermediate strains (VISA) and penicillin-resistant pneumococci (PRPN). Combined with other drugs linezolid interacts favourably against many important pathogens and it is able to affect some bacterial virulence factors as well as produce a postantibiotic effect. Results from experimental models of infection reveal linezolid to be highly active in vivo against infections due to Gram-positive pathogens. Linezolid may be administered either intravenously or orally with oral bioavailability of approximately 100% and limited adverse effects. The clinical efficacy of linezolid has been investigated in several phase II and III trials. Linezolid has been proved to be useful in severe infections sustained by multiresistant Gram-positive micro-organisms. Synthesis of the second-generation oxazolidinones with improved potency against Gram-positive and negative bacteria is currently under way.
Collapse
Affiliation(s)
- A Marchese
- Institute of Microbiology, Genoa, Italy.
| | | |
Collapse
|
30
|
Brandt CM, Honscha M, Truong ND, Holland R, Hövener B, Bryskier A, Lütticken R, Reinert RR. Macrolide resistance in Streptococcus pyogenes isolates from throat infections in the region of Aachen, Germany. Microb Drug Resist 2002; 7:165-70. [PMID: 11442342 DOI: 10.1089/10766290152045039] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Macrolide-resistance was assessed in 216 consecutive Streptococcus pyogenes isolates from throat infections in the region of Aachen, Germany. Seventeen isolates were resistant to erythromycin: 12 isolates revealed a macrolide (M) phenotype and harbored mefA, and five strains expressed an inducible macrolide-lincosamide-streptogramin B (MLSB) phenotype of which four strains harbored ermA(TR) and one strain contained ermB(AM). Telithromycin (HMR 3647) and quinupristin/dalfopristin remained active particularly against the ermA(TR)-containing S. pyogenes isolates studied. Random amplified polymorphic DNA analysis identified multiple clones among erythromycin-resistant strains, but did not discriminate beyond the emm-type. mefA was present in three isolates either with emm2, emm12, or emm75, and in nine isolates with emm4. All four strains with ermA(TR) contained emm77, and the single strain with ermB(AM) harbored emm1. Despite the relative low rate of macrolide-resistance, these data suggest that at least three different macrolide-resistance determinants are prevalent in Germany and that mefA has spread rapidly into multiple clones of S. pyogenes.
Collapse
Affiliation(s)
- C M Brandt
- Institute of Medical Microbiology, National Reference Center for Streptococci, University Hospital RWTH Aachen, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Abstract
Many common gram-positive pathogens (eg, Staphylococcus aureus, Enterococcus spp, and Streptococcus pneumoniae) have become increasingly resistant to antimicrobial agents, and new drugs with activity against gram-positive bacteria are urgently needed. The oxazolidinones, a new chemical class of synthetic antimicrobial agent, have a unique mechanism of inhibiting bacterial protein synthesis. Linezolid, the first oxazolidinone to be approved for clinical use, displays in-vitro activity (generally bacteriostatic) against many important resistant pathogens, including meticillin-resistant Staph aureus, vancomycin-resistant enterococci, and penicillin-resistant Strep pneumoniae. Linezolid is a parenteral agent that also possesses near-complete oral bioavailability plus favourable pharmacokinetic and toxic effect profiles. Clinical trials confirm the activity of linezolid in the setting of pneumonia, skin and soft-tissue infections, and infections due to vancomycin-resistant enterococci. Linezolid shows promise as an alternative to glycopeptides and streptogramins to treat serious infections due to resistant gram-positive organisms. New agents with greater potency and new spectra of activity could arise from further modification of the oxazolidinone nucleus.
Collapse
Affiliation(s)
- D J Diekema
- Division of Infectious Diseases, Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
| | | |
Collapse
|
32
|
Thornsberry C, Karlowsky JA, Kelly LJ, Draghi DC, Critchley IA, Jones ME, Sahm DF. Comparative activity of cefditoren and other oral beta-lactams against nonpneumococcal streptococci. Chemotherapy 2001; 47:332-43. [PMID: 11561135 DOI: 10.1159/000048540] [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: 11/19/2022]
Abstract
BACKGROUND In vitro studies of cefditoren activity have focused primarily on Streptococcus pneumoniae and other bacterial species isolated from patients with respiratory infections, but relatively few reports have been published describing the activity of cefditoren against clinical isolates of nonpneumococcal streptococci. METHODS Cefditoren activity was determined by broth microdilution (M7-A5, NCCLS, 2000) for 450 viridans group streptococci, 917 Streptococcus pyogenes and 800 other beta-hemolytic streptococci collected throughout the US during 1999-2000. RESULTS Against viridans group streptococci, cefditoren (MIC(90), 0.5 microg/ml) was 4- to 32-fold more active than the other beta-lactams tested (penicillin ampicillin, amoxicillin-clavulanate, cefprozil and cefuroxime). The difference in activity between cefditoren and the other beta-lactams was greater for penicillin-nonsusceptible isolates (MIC(90s), 1 microg/ml versus 8-32 microg/ml) than among penicillin-susceptible isolates (MIC(90s), 0.12 versus 0.25- 1 microg/ml). Cefditoren also demonstrated potent activity against S. pyogenes (MIC(90), 0.015 microg/ml) and other beta-hemolytic streptococci (MIC(90), 0.06 microg/ml), comparable to that of the other beta-lactams. CONCLUSIONS The activity demonstrated by cefditoren against nonpneumococcal streptococci, including beta-lactam- and macrolide-resistant isolates, suggests that this agent holds promise as therapy for infections caused by all clinically significant species of streptococci.
Collapse
Affiliation(s)
- C Thornsberry
- Focus Technologies, Inc. (formerly MRL), Brentwood, TN, USA
| | | | | | | | | | | | | |
Collapse
|
33
|
Pantosti A, D'Ambrosio F, Bordi E, Scotto D'Abusco A, Del Grosso M. Activity of quinupristin-dalfopristin in invasive isolates of Streptococcus pneumoniae from Italy. Clin Microbiol Infect 2001; 7:503-6. [PMID: 11678935 DOI: 10.1046/j.1198-743x.2001.00298.x] [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: 11/20/2022]
Abstract
Eighty-five recent isolates of Streptococcus pneumoniae from patients with invasive disease were examined for their susceptibility to erythromycin, clindamycin, penicillin and quinupristin-dalfopristin by E test. A novel duplex PCR assay was used to detect the presence of the erm(B) or mef(A) genes in all of the erythromycin-resistant isolates. All of the strains tested were susceptible to the combination quinupristin-dalfopristin, regardless of their susceptibility to penicillin or to erythromycin. By duplex PCR, two-thirds of the erythromycin-resistant strains harbored erm, and one-third harbored mef. The activity of quinupristin-dalfopristin was not influenced by the genetic determinant of erythromycin resistance. The in vitro susceptibility of S. pneumoniae to quinupristin-dalfopristin is promising for future use; however, it is important to monitor the possible emergence of resistance.
Collapse
Affiliation(s)
- A Pantosti
- Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
| | | | | | | | | |
Collapse
|
34
|
De Mouy D, Cavallo JD, Leclercq R, Fabre R. Antibiotic susceptibility and mechanisms of erythromycin resistance in clinical isolates of Streptococcus agalactiae: French multicenter study. Antimicrob Agents Chemother 2001; 45:2400-2. [PMID: 11451709 PMCID: PMC90666 DOI: 10.1128/aac.45.8.2400-2402.2001] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Among 126 Streptococcus agalactiae isolates collected in 10 French laboratories in 1999, 27 (21.4%) had macrolide resistance related to the presence of erm(B) (11 strains), erm(A) subclass erm(TR) (10 strains), and mef(A) genes (2 strains) and the presence of combinations of erm(B) and erm(A) genes or mef(A) genes (3 strains).
Collapse
Affiliation(s)
- D De Mouy
- Association de Formation Continue en Pathologie Infectieuse des Biologistes, 75005 Paris, France
| | | | | | | |
Collapse
|
35
|
Kennedy MJ, Abdel-Rahman SM, Kearns GL. Oxazolidinones: Clinical pharmacology and use in the treatment of infections caused by resistant gram-positive pathogens. ACTA ACUST UNITED AC 2001. [DOI: 10.1053/spid.2001.24094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
36
|
Andes D. Pharmacokinetic and pharmacodynamic properties of antimicrobials in the therapy of respiratory tract infections. Curr Opin Infect Dis 2001; 14:165-72. [PMID: 11979128 DOI: 10.1097/00001432-200104000-00010] [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: 11/25/2022]
Abstract
Antimicrobial pharmacodynamics examines the relationship between the pharmacokinetics of a drug over time and its treatment effect. Pharmacokinetic/pharmacodynamic parameters have been shown to be predictors of the antimicrobial activity of a variety of drugs. The pharmacodynamic parameter linked to efficacy has been demonstrated to vary for different antimicrobial classes. Within an antimicrobial class, the magnitude of the pharmacodynamic parameter predictive of efficacy has been shown to be similar, as long as free-drug levels in serum are considered. Treatment outcome predictions based upon parameter magnitudes have correlated well and have been useful for assessing the future course of both susceptible and resistant pathogens of the respiratory tract. This has been useful for the development of susceptibility breakpoints and antimicrobial treatment guidelines. Recent studies have begun to investigate the relationship between antimicrobial pharmacodynamics and the prevention of drug resistance.
Collapse
Affiliation(s)
- D Andes
- Department of Medicine, Section of Infectious Disease, University of Wisconsin School of Medicine, Madison, Wisconsin 53792, USA.
| |
Collapse
|
37
|
Montanari MP, Mingoia M, Giovanetti E, Varaldo PE. Differentiation of resistance phenotypes among erythromycin-resistant Pneumococci. J Clin Microbiol 2001; 39:1311-5. [PMID: 11283047 PMCID: PMC87930 DOI: 10.1128/jcm.39.4.1311-1315.2001] [Citation(s) in RCA: 44] [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
Laboratory differentiation of erythromycin resistance phenotypes is poorly standardized for pneumococci. In this study, 85 clinical isolates of erythromycin-resistant (MIC > or = 1 microg/ml) Streptococcus pneumoniae were tested for the resistance phenotype by the erythromycin-clindamycin double-disk test (previously used to determine the macrolide resistance phenotype in Streptococcus pyogenes strains) and by MIC induction tests, i.e., by determining the MICs of macrolide antibiotics without and with pre-exposure to 0.05 microg of erythromycin per ml. By the double-disk test, 65 strains, all carrying the erm(AM) determinant, were assigned to the constitutive macrolide, lincosamide, and streptogramin B resistance (cMLS) phenotype, and the remaining 20, all carrying the mef(E) gene, were assigned to the recently described M phenotype; an inducible MLS resistance (iMLS) phenotype was not found. The lack of inducible resistance to clindamycin was confirmed by determining clindamycin MICs without and with pre-exposure to subinhibitory concentrations of erythromycin. In macrolide MIC and MIC-induction tests, whereas homogeneous susceptibility patterns were observed among the 20 strains assigned to the M phenotype by the double-disk test, two distinct patterns were recognized among the 65 strains assigned to the cMLS phenotype by the same test; one pattern (n = 10; probably that of the true cMLS isolates) was characterized by resistance to rokitamycin also without induction, and the other pattern (n = 55; designated the iMcLS phenotype) was characterized by full or intermediate susceptibility to rokitamycin without induction turning to resistance after induction, with an MIC increase by more than three dilutions. A triple-disk test, set up by adding a rokitamycin disk to the erythromycin and clindamycin disks of the double-disk test, allowed the easy differentiation not only of pneumococci with the M phenotype from those with MLS resistance but also, among the latter, of those of the true cMLS phenotype from those of the iMcLS phenotype. While distinguishing MLS from M resistance in pneumococci is easily and reliably achieved, the differentiation of constitutive from inducible MLS resistance is far more uncertain and is strongly affected by the antibiotic used to test inducibility.
Collapse
Affiliation(s)
- M P Montanari
- Institute of Microbiology, University of Ancona Medical School, 60131 Ancona, Italy
| | | | | | | |
Collapse
|
38
|
Abstract
BACKGROUND Linezolid is the first oxazolidinone anti-infective agent marketed in the United States. It is indicated for the treatment of nosocomial pneumonia, complicated skin and skin-structure infections caused by methicillin-sensitive or methicillin-resistant Staphylococcus aureus and other susceptible organisms, and vancomycin-resistant Enterococcus faecium infections. It also is indicated for the treatment of uncomplicated skin and skin-structure infections caused by methicillin-sensitive S. aureus or Streptococcus pyogenes, and community-acquired pneumonia caused by penicillin-sensitive Streptococcus pneumoniae. OBJECTIVE This article reviews the pharmacologic properties and clinical usefulness of linezolid. METHODS Using the terms linezolid, PNU-100766, and oxazolidinone, we performed a literature search of the following databases: MEDLINE (1966 to September 2000), HealthSTAR (1993 to September 2000), Iowa Drug Information Service (1966 to September 2000), International Pharmaceutical Abstracts (1970 to September 2000), PharmaProjects (January 2000 version), and meeting abstracts of the Infectious Diseases Society of America and the Interscience Conference on Antimicrobial Agents and Chemotherapy (1996 to 2000). RESULTS Linezolid has a unique structure and mechanism of action, which targets protein synthesis at an exceedingly early stage. Consequently, cross-resistance with other commercially available antimicrobial agents is unlikely. It is primarily effective against gram-positive bacteria. To date, resistance to linezolid has been reported in patients infected with enterococci. The pharmacokinetic parameters of linezolid in adults are not altered by hepatic or renal function, age, or sex to an extent requiring dose adjustment. Linezolid is metabolized via morpholine ring oxidation, which is independent of the cytochrome P450 (CYP450) enzyme system; as a result, linezolid is unlikely to interact with medications that stimulate or inhibit CYP450 enzymes. Compassionate-use trials and other clinical studies involving mainly adult hospitalized patients with gram-positive infections have shown that linezolid administered intravenously or orally is effective in a variety of nosocomial and community-acquired infections, including those caused by resistant gram-positive organisms. Reported adverse effects include thrombocytopenia. diarrhea, headache, nausea, vomiting, insomnia, constipation, rash, and dizziness. Preliminary pharmacoeconomic data indicate that a significantly higher percentage of patients receiving linezolid therapy versus comparator could be discharged from the hospital by day 7 (P = 0.005). CONCLUSIONS Linezolid appears to be effective while maintaining an acceptable tolerability profile. Due to the risk of bacterial resistance, linezolid should be reserved for the treatment of documented serious vancomycin-resistant enterococcal infections.
Collapse
Affiliation(s)
- H B Fung
- Critical Care Center, Veterans Affairs Medical Center, Bronx, New York 10468, USA.
| | | | | |
Collapse
|
39
|
Fitoussi F, Doit C, Geslin P, Brahimi N, Bingen E. Mechanisms of macrolide resistance in clinical pneumococcal isolates in France. Antimicrob Agents Chemother 2001; 45:636-8. [PMID: 11158772 PMCID: PMC90344 DOI: 10.1128/aac.45.2.636-638.2001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genetic basis of macrolide resistance was investigated in a collection of 48 genotypically unrelated clinical isolates of Streptococcus pneumoniae obtained between 1987 and 1997 in France. All strains were resistant to erythromycin, clindamycin, and streptogramin B, exhibiting a macrolide-lincosamide-streptogramin B resistance phenotype, and harbored the erm(B) gene. None of the strains carried the mef(A) or erm(A) subclass erm(TR) gene.
Collapse
Affiliation(s)
- F Fitoussi
- Service de Microbiologie, Hôpital Robert Debré, 75019 Paris, France
| | | | | | | | | |
Collapse
|
40
|
Syrogiannopoulos GA, Grivea IN, Tait-Kamradt A, Katopodis GD, Beratis NG, Sutcliffe J, Appelbaum PC, Davies TA. Identification of an erm(A) erythromycin resistance methylase gene in Streptococcus pneumoniae isolated in Greece. Antimicrob Agents Chemother 2001; 45:342-4. [PMID: 11120994 PMCID: PMC90289 DOI: 10.1128/aac.45.1.342-344.2001] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In a serotype 11A clone of erythromycin-resistant pneumococci isolated from young Greek carriers, we identified the nucleotide sequence of erm(A), a methylase gene previously described as erm(TR) in Streptococcus pyogenes. The erm(A) pneumococci were resistant to 14- and 15-member macrolides, inducibly resistant to clindamycin, and susceptible to streptogramin B. To our knowledge, this is the first identification of resistance to erythromycin in S. pneumoniae attributed solely to the carriage of the erm(A) gene.
Collapse
Affiliation(s)
- G A Syrogiannopoulos
- Department of Pediatrics, General University Hospital, University of Patras, School of Medicine, Patras, Greece.
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
Synercid (RP 59500), the first injectable streptogramin antibiotic, is composed of two semisynthetic pristinamycin derivatives, quinupristin and dalfopristin. Individually, each component has bacteriostatic activity against staphylococci and streptococci, but together, the agents exhibit synergy, leading to bactericidal activity. The combination drug, however, is bacteriostatic against Enterococcus faecium and has poor activity against Enterococcus faecalis. Despite a short half-life, an extended postantibiotic effect allows the agent to be dosed every 8-12 hours. Both drugs are largely hepatically metabolized and excreted in bile. Although not metabolized by cytochrome P450 3A4, quinupristin-dalfopristin can inhibit agents that are metabolized through this pathway. Dosage adjustments may be necessary in patients with hepatic dysfunction. Alterations in renal function have minimal effects on the agent's pharmacokinetics. Adverse events include arthralgia, myalgias, and infusion-related pain. Based on available data, quinupristin-dalfopristin appears to have a role in treating severely ill patients with infections due to multiresistant gram-positive pathogens.
Collapse
Affiliation(s)
- G Delgado
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, 60612, USA
| | | | | | | |
Collapse
|