1
|
Abouelhassan Y, Kuti JL, Nicolau DP, Abdelraouf K. Ampicillin-sulbactam against Acinetobacter baumannii infections: pharmacokinetic/pharmacodynamic appraisal of current susceptibility breakpoints and dosing recommendations. J Antimicrob Chemother 2024:dkae218. [PMID: 39031073 DOI: 10.1093/jac/dkae218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 06/11/2024] [Indexed: 07/22/2024] Open
Abstract
BACKGROUND Sulbactam dosing for Acinetobacter baumannii infections has not been standardized due to limited available pharmacokinetics/pharmacodynamics (PK/PD) data. Herein, we report a comprehensive PK/PD analysis of ampicillin-sulbactam against A. baumannii pneumonia. METHODS Twenty-one A. baumannii clinical isolates were tested in the neutropenic murine pneumonia model. For dose-ranging studies, groups of mice were administered escalating doses of ampicillin-sulbactam. Changes in log10cfu/lungs relative to 0 h were assessed. Dose-fractionation studies were performed. Estimates of the percentage of of time during which the unbound plasma sulbactam concentrations exceeded the MIC (%fT > MIC) required for different efficacy endpoints were calculated. The probabilities of target attainment (PTA) for the 1-log kill plasma targets were estimated following clinically utilized sulbactam regimens. RESULTS Dose-fractionation studies demonstrated time-dependent kill. Isolates resistant to both sulbactam and meropenem required three times the exposures to achieve 1-log kill; median [IQR] %fT > MIC of 60.37% [51.6-66.8] compared with other phenotypes (21.17 [16.0-32.9] %fT > MIC). Sulbactam standard dose (1 g q6h, 0.5 h infusion) provided >90% PTA up to MIC of 4 mg/L. Sulbactam 3 g q8h, 4 h inf provided greater PTA for isolates with sulbactam-intermediate susceptibility (8 mg/L, 100% versus 86% following the standard dose). Despite the higher exposure following 3 g q8h, 4 h inf, PTA was ≤57% among sulbactam-resistant/meropenem-resistant isolates. CONCLUSION Sulbactam standard dose is a valuable regimen across sulbactam-susceptible isolates while the high-dose extended-infusion provides additional benefit against sulbactam-intermediate isolates. Given that most of the sulbactam-resistant A. baumannii isolates are meropenem-resistant, high-dose prolonged-infusion regimens are not expected to be effective as monotherapy against infections due to these isolates.
Collapse
Affiliation(s)
- Yasmeen Abouelhassan
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA
| | - Joseph L Kuti
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA
| | - David P Nicolau
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA
- Division of Infectious Diseases, Hartford Hospital, Hartford, CT, USA
| | - Kamilia Abdelraouf
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA
| |
Collapse
|
2
|
Abouelhassan Y, Nicolau DP, Abdelraouf K. Defining optimal sulbactam regimens for treatment of Acinetobacter baumannii pneumonia and impact of blaOXA-23 on efficacy. J Antimicrob Chemother 2024:dkae229. [PMID: 38997215 DOI: 10.1093/jac/dkae229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 06/19/2024] [Indexed: 07/14/2024] Open
Abstract
OBJECTIVES We evaluated the efficacies of human-simulated regimens (HSRs) of two clinically utilized sulbactam regimens: 1 g q6h 0.5 h infusion (maximum FDA-approved dosage) and 3 g q8h 4 h infusion (high-dose, prolonged-infusion regimen), against Acinetobacter baumannii in a translational murine model. METHODS Thirty-two clinical A. baumannii isolates were investigated, of which 16 were sulbactam resistant (MIC ≥ 16 mg/L), 6 were sulbactam intermediate (MIC = 8 mg/L) and 10 were sulbactam susceptible (MIC ≤ 4 mg/L). Efficacies of the two sulbactam HSRs were assessed in the neutropenic murine pneumonia model. Changes in log10 cfu/lungs at 24 h compared with 0 h controls were measured, and efficacy was defined as achieving 1 log kill relative to baseline. WGS of the isolates and bioinformatics analysis were performed to explore potential associations between the genomic backgrounds and the in vivo responses. RESULTS Eleven isolates harboured blaOXA-23, of which 10 were sulbactam resistant, 1 was sulbactam intermediate while none was sulbactam susceptible. Both sulbactam HSRs achieved >1 log kill against sulbactam-susceptible isolates. Against sulbactam-intermediate and sulbactam-resistant isolates, lack of efficacy correlated with the presence of the blaOXA-23 gene; sulbactam 1 g HSR and 3 g HSR did not show efficacy against 11/11 and 9/11 blaOXA-23-positive isolates, respectively, while efficacy was observed against all 11 blaOXA-23-negative sulbactam-intermediate and sulbactam-resistant isolates (i.e. harbouring other resistance genes). CONCLUSIONS A sulbactam high-dose prolonged-infusion regimen provides comparable activity to the standard dose against isolates currently considered sulbactam susceptible. However, the activity against isolates with intermediate and resistant susceptibility could be predicted by the detection of blaOXA-23. Enhancing detection capabilities of common diagnostic modalities to include OXA-23 can improve patient outcome.
Collapse
Affiliation(s)
- Yasmeen Abouelhassan
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA
| | - David P Nicolau
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA
- Division of Infectious Diseases, Hartford Hospital, Hartford, CT, USA
| | - Kamilia Abdelraouf
- Center for Anti-Infective Research and Development, Hartford Hospital, Hartford, CT, USA
| |
Collapse
|
3
|
August B, Matlob A, Kale-Pradhan PB. Sulbactam-Durlobactam in the Treatment of Carbapenem-Resistant Acinetobacter baumannii Infections. Ann Pharmacother 2024; 58:735-741. [PMID: 37817550 DOI: 10.1177/10600280231204566] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/12/2023] Open
Abstract
OBJECTIVE To review the pharmacology, efficacy, and safety of intravenous sulbactam-durlobactam (SUL-DUR) in the treatment of carbapenem-resistant Acinetobacter baumannii (CRAB) infections. DATA SOURCES PubMed databases and ClinicalTrials.gov were searched using the following terms: Sulbactam Durlobactam, ETX2514, Xacduro, Sulbactam-ETX2514, ETX2514SUL. STUDY SELECTION AND DATA EXTRACTION Articles published in English between January 1985 and September 13, 2023, related to pharmacology, safety, efficacy, and clinical trials were reviewed. DATA SYNTHESIS A phase II trial compared SUL-DUR with placebo with imipenem and cilastatin in both groups. Overall treatment success in the microbiological intention-to-treat analysis was reported in 76.6% of patients in the SUL-DUR group compared with 81% patients in the placebo group. A phase III trial compared SUL-DUR with colistin in adults with confirmed CRAB infections. Patients received either SUL-DUR or colistin and background therapy with imipenem-cilastatin. SUL-DUR was noninferior to colistin for 28-day all-cause mortality (19% vs 32.3%, treatment difference -13.2%; 95% CI [-30.0 to 3.5]). RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING DRUGS Clinicians have limited options to treat CRAB infections. SUL-DUR has demonstrated efficacy against CRAB in patients with pneumonia and may be considered a viable treatment option. Nonetheless, potential impact of concomitant imipenem-cilastatin as background therapy on clinical trial findings is unclear. Further studies are needed to elucidate the role of SUL-DUR alone or in combination with other active antimicrobials for the treatment of CRAB infections. CONCLUSIONS SUL-DUR has shown to be predominantly noninferior to alternative antibiotics in the treatment of pneumonias caused by CRAB, making it a viable treatment option. Further postmarketing data is needed to ascertain its role in other infections.
Collapse
Affiliation(s)
- Benjamin August
- Department of Pharmacy Practice, Henry Ford Hospital, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA
| | - Andrew Matlob
- Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA
| | - Pramodini B Kale-Pradhan
- Department of Pharmacy Practice, Ascension St. John Hospital, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI, USA
| |
Collapse
|
4
|
Plasencia-Rebata S, Levy-Blitchtein S, Del Valle-Mendoza J, Silva-Caso W, Peña-Tuesta I, Vicente Taboada W, Barreda Bolaños F, Aguilar-Luis MA. Effect of Phenylalanine-Arginine Beta-Naphthylamide on the Values of Minimum Inhibitory Concentration of Quinolones and Aminoglycosides in Clinical Isolates of Acinetobacter baumannii. Antibiotics (Basel) 2023; 12:1071. [PMID: 37370390 DOI: 10.3390/antibiotics12061071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/06/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
(1) Background: Acinetobacter baumannii has become the most important pathogen responsible for nosocomial infections in health systems. It expresses several resistance mechanisms, including the production of β-lactamases, changes in the cell membrane, and the expression of efflux pumps. (2) Methods: A. baumannii was detected by PCR amplification of the blaOXA-51-like gene. Antimicrobial susceptibility to fluoroquinolones and aminoglycosides was assessed using the broth microdilution technique according to 2018 CLSI guidelines. Efflux pump system activity was assessed by the addition of a phenylalanine-arginine beta-naphthylamide (PAβN) inhibitor. (3) Results: A total of nineteen A. baumannii clinical isolates were included in the study. In an overall analysis, in the presence of PAβN, amikacin susceptibility rates changed from 84.2% to 100%; regarding tobramycin, they changed from 68.4% to 84.2%; for nalidixic acid, they changed from 73.7% to 79.0%; as per ciprofloxacin, they changed from 68.4% to 73.7%; and, for levofloxacin, they stayed as 79.0% in both groups. (4) Conclusions: The addition of PAβN demonstrated a decrease in the rates of resistance to antimicrobials from the family of quinolones and aminoglycosides. Efflux pumps play an important role in the emergence of multidrug-resistant A. baumannii strains, and their inhibition may be useful as adjunctive therapy against this pathogen.
Collapse
Affiliation(s)
- Stefany Plasencia-Rebata
- Escuela de Medicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
| | - Saul Levy-Blitchtein
- Escuela de Medicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Microbiology Department, Vall d'Hebron University Hospital, 08034 Barcelona, Spain
| | - Juana Del Valle-Mendoza
- Escuela de Medicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Laboratorio de Biomedicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Instituto de Investigación Nutricional, Lima 15024, Peru
| | - Wilmer Silva-Caso
- Escuela de Medicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Laboratorio de Biomedicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Instituto de Investigación Nutricional, Lima 15024, Peru
| | - Isaac Peña-Tuesta
- Laboratorio de Biomedicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Instituto de Investigación Nutricional, Lima 15024, Peru
| | | | | | - Miguel Angel Aguilar-Luis
- Escuela de Medicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Laboratorio de Biomedicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima 15023, Peru
- Instituto de Investigación Nutricional, Lima 15024, Peru
| |
Collapse
|
5
|
Morrisette T, Stamper KC, Lev KL, Kebriaei R, Holger DJ, Abdul-Mutakabbir JC, Kunz Coyne AJ, Rybak MJ. Evaluation of Omadacycline Alone and in Combination with Rifampin against Staphylococcus aureus and Staphylococcus epidermidis in an In Vitro Pharmacokinetic/Pharmacodynamic Biofilm Model. Antimicrob Agents Chemother 2023; 67:e0131722. [PMID: 37222591 PMCID: PMC10269082 DOI: 10.1128/aac.01317-22] [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: 09/30/2022] [Accepted: 03/27/2023] [Indexed: 05/25/2023] Open
Abstract
Biofilm-associated infections lead to substantial morbidity. Omadacycline (OMC) is a novel aminomethylcycline with potent in vitro activity against Staphylococcus aureus and Staphylococcus epidermidis, but data surrounding its use in biofilm-associated infections are lacking. We investigated the activity of OMC alone and in combination with rifampin (RIF) against 20 clinical strains of staphylococci in multiple in vitro biofilm analyses, including an in vitro pharmacokinetic/pharmacodynamic (PK/PD) CDC biofilm reactor (CBR) model (simulating human exposures). The observed MICs for OMC demonstrated potent activity against the evaluated strains (0.125 to 1 mg/L), with an increase of MICs generally observed in the presence of biofilm (0.25 to >64 mg/L). Furthermore, RIF was shown to reduce OMC biofilm MICs (bMICs) in 90% of strains, and OMC plus RIF combination in biofilm time-kill analyses (TKAs) exhibited synergistic activity in most of the strains. Within the PK/PD CBR model, OMC monotherapy primarily displayed bacteriostatic activity, while RIF monotherapy generally exhibited initial bacterial eradication, followed by rapid regrowth likely due to the emergence of RIF resistance (RIF bMIC, >64 mg/L). However, the combination of OMC plus RIF produced rapid and sustained bactericidal activity in nearly all the strains (3.76 to 4.03 log10 CFU/cm2 reductions from starting inoculum in strains in which bactericidal activity was reached). Furthermore, OMC was shown to prevent the emergence of RIF resistance. Our data provide preliminary evidence that OMC in combination with RIF could be a viable option for biofilm-associated infections with S. aureus and S. epidermidis. Further research involving OMC in biofilm-associated infections is warranted.
Collapse
Affiliation(s)
- Taylor Morrisette
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Kyle C. Stamper
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Katherine L. Lev
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Razieh Kebriaei
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Dana J. Holger
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Jacinda C. Abdul-Mutakabbir
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Ashlan J. Kunz Coyne
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Michael J. Rybak
- Anti-Infective Research Laboratory, Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, USA
- Division of Infectious Diseases, Department of Medicine, Wayne State University, Detroit, Michigan, USA
- Department of Pharmacy, Detroit Receiving Hospital, Detroit, Michigan, USA
| |
Collapse
|
6
|
Evasion of Antimicrobial Activity in Acinetobacter baumannii by Target Site Modifications: An Effective Resistance Mechanism. Int J Mol Sci 2022; 23:ijms23126582. [PMID: 35743027 PMCID: PMC9223528 DOI: 10.3390/ijms23126582] [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: 05/03/2022] [Revised: 06/05/2022] [Accepted: 06/10/2022] [Indexed: 11/17/2022] Open
Abstract
Acinetobacter baumannii is a Gram-negative bacillus that causes multiple infections that can become severe, mainly in hospitalized patients. Its high ability to persist on abiotic surfaces and to resist stressors, together with its high genomic plasticity, make it a remarkable pathogen. Currently, the isolation of strains with high antimicrobial resistance profiles has gained relevance, which complicates patient treatment and prognosis. This resistance capacity is generated by various mechanisms, including the modification of the target site where antimicrobial action is directed. This mechanism is mainly generated by genetic mutations and contributes to resistance against a wide variety of antimicrobials, such as β-lactams, macrolides, fluoroquinolones, aminoglycosides, among others, including polymyxin resistance, which includes colistin, a rescue antimicrobial used in the treatment of multidrug-resistant strains of A. baumannii and other Gram-negative bacteria. Therefore, the aim of this review is to provide a detailed and up-to-date description of antimicrobial resistance mediated by the target site modification in A. baumannii, as well as to detail the therapeutic options available to fight infections caused by this bacterium.
Collapse
|
7
|
Mellouli A, Maamar B, Bouzakoura F, Messadi A, Thabet L. [Not Available]. ANNALS OF BURNS AND FIRE DISASTERS 2021; 34:218-225. [PMID: 34744536 PMCID: PMC8534301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/14/2021] [Indexed: 06/13/2023]
Abstract
Acinetobacter baumannii is a feared pathogen in the burn center due to its opportunistic nature and its multidrug resistance. Our purpose was to study the incidence density of Acinetobacter baumannii colonization and infection and to determine the antibiotic susceptibility of the strains isolated in patients hospitalized in the Trauma and Burn Center Burn Unit in Tunisia. Our retrospective study included 1517 non-repetitive strains of Acinetobacter baumannii, between January 2012 and September 2020, with an average rate of 12.2% of the service's bacterial ecology. The incidence density of Acinetobacter baumannii colonization and infection was 13.7‰ days of in-patient stay and 14.1‰ days of in-patient stay, respectively. A positive and statistically significant correlation between Acinetobacter baumannii colonization and infection (rs=0,7; p=0.005) was noted in our study. The colonization strains were mainly isolated from central catheters (71.2%) and skin swab samples (22.9%). Infections were dominated by bacteremia (47.6%) and respiratory tract infections (25.4%). Bacteremia was microbiologically documented in 53% of cases. The most common source of bacteremia was central catheters (60.8%), skin (22.2%) and respiratory tract (15.5%). The rates of resistance inAcinetobacter baumannii to the antimicrobial agents tested were high: ceftazidime (85.2%), pipéracillin-tazobactam (95.6%), imipenem (95.3%), amikacine (91.1%), ciprofloxacin (93.5%), rifampicin (36.4%) and cotrimoxazole (88.1%). The resistance of colistin was noted in 1.8% of cases.
Collapse
Affiliation(s)
- A. Mellouli
- Laboratoire de Biologie Médicale et Banque du Sang, Centre de Traumatologie et des Grands Brûlés de Ben Arous, Tunisie
- Faculté de Médecine de Tunis, Tunisie
- Université Tunis El Manar, Tunis, Tunisie
| | - B. Maamar
- Laboratoire de Biologie Médicale et Banque du Sang, Centre de Traumatologie et des Grands Brûlés de Ben Arous, Tunisie
- Faculté de Médecine de Tunis, Tunisie
| | - F. Bouzakoura
- Laboratoire de Biologie Médicale et Banque du Sang, Centre de Traumatologie et des Grands Brûlés de Ben Arous, Tunisie
- Faculté de Médecine de Tunis, Tunisie
| | - A.A. Messadi
- Service de Réanimation des Brûlés, Centre de Traumatologie et des Grands Brûlés de Ben Arous, Tunisie
- Faculté de Médecine de Tunis, Tunisie
| | - L. Thabet
- Service de Réanimation des Brûlés, Centre de Traumatologie et des Grands Brûlés de Ben Arous, Tunisie
- Faculté de Médecine de Tunis, Tunisie
| |
Collapse
|
8
|
Semi-mechanistic PK/PD modelling of fosfomycin and sulbactam combination against carbapenem-resistant Acinetobacter baumannii. Antimicrob Agents Chemother 2021; 65:AAC.02472-20. [PMID: 33685901 PMCID: PMC8092884 DOI: 10.1128/aac.02472-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Due to limited treatment options for carbapenem-resistant Acinetobacter baumannii (CR-AB) infections, antibiotic combinations are now considered potential treatments for CR-AB. This study aimed to explore the utility of fosfomycin-sulbactam combination (FOS/SUL) therapy against CR-AB isolates.Synergism of FOS/SUL against 50 clinical CR-AB isolates were screened using the checkerboard method. Thereafter, time-kill studies against two CR-AB isolates were performed. The time-kill data were described using a semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model. Monte Carlo simulations were then performed to estimate the probability of stasis, 1-log kill and 2-log kill after 24-hours with combination therapy.The FOS/SUL combination demonstrated a synergistic effect against 74% of isolates. No antagonism was observed. The MIC50 and MIC90 of FOS/SUL were decreased four- to eight-fold, compared to the monotherapy MIC50 and MIC90 In the time-kill studies, the combination displayed bactericidal activity against both isolates and synergistic activity against one isolate, at the highest clinically achievable concentrations. Our PK/PD model was able to describe the interaction between fosfomycin and sulbactam in vitro Bacterial kill was mainly driven by sulbactam, with fosfomycin augmentation. FOS/SUL regimens that included sulbactam 4 g every 8 hours, demonstrated a probability of target attainment of 1-log10 kill at 24 h of ∼69-76%, as compared to ∼15-30% with monotherapy regimens at the highest doses.The reduction in the MIC values and the achievement of a moderate PTA of a 2-log10 reduction in bacterial burden demonstrated that FOS/SUL may potentially be effective against some CR-AB infections.
Collapse
|
9
|
Ayoub Moubareck C, Hammoudi Halat D. Insights into Acinetobacter baumannii: A Review of Microbiological, Virulence, and Resistance Traits in a Threatening Nosocomial Pathogen. Antibiotics (Basel) 2020; 9:antibiotics9030119. [PMID: 32178356 PMCID: PMC7148516 DOI: 10.3390/antibiotics9030119] [Citation(s) in RCA: 201] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/12/2022] Open
Abstract
Being a multidrug-resistant and an invasive pathogen, Acinetobacter baumannii is one of the major causes of nosocomial infections in the current healthcare system. It has been recognized as an agent of pneumonia, septicemia, meningitis, urinary tract and wound infections, and is associated with high mortality. Pathogenesis in A. baumannii infections is an outcome of multiple virulence factors, including porins, capsules, and cell wall lipopolysaccharide, enzymes, biofilm production, motility, and iron-acquisition systems, among others. Such virulence factors help the organism to resist stressful environmental conditions and enable development of severe infections. Parallel to increased prevalence of infections caused by A. baumannii, challenging and diverse resistance mechanisms in this pathogen are well recognized, with major classes of antibiotics becoming minimally effective. Through a wide array of antibiotic-hydrolyzing enzymes, efflux pump changes, impermeability, and antibiotic target mutations, A. baumannii models a unique ability to maintain a multidrug-resistant phenotype, further complicating treatment. Understanding mechanisms behind diseases, virulence, and resistance acquisition are central to infectious disease knowledge about A. baumannii. The aims of this review are to highlight infections and disease-producing factors in A. baumannii and to touch base on mechanisms of resistance to various antibiotic classes.
Collapse
Affiliation(s)
- Carole Ayoub Moubareck
- College of Natural and Health Sciences, Zayed University, Dubai P.O. Box 144534, UAE
- Correspondence: ; Tel.: +971-4-402-1745
| | - Dalal Hammoudi Halat
- Department of Pharmaceutical Sciences, School of Pharmacy, Lebanese International University, Beirut, Bekaa Campuses 1103, Lebanon;
| |
Collapse
|
10
|
Ali S. Acinetobacter infections: Overview and treatment dilemma. CHRISMED JOURNAL OF HEALTH AND RESEARCH 2020. [DOI: 10.4103/cjhr.cjhr_30_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
11
|
Jaśkiewicz M, Neubauer D, Kazor K, Bartoszewska S, Kamysz W. Antimicrobial Activity of Selected Antimicrobial Peptides Against Planktonic Culture and Biofilm of Acinetobacter baumannii. Probiotics Antimicrob Proteins 2019; 11:317-324. [PMID: 30043322 PMCID: PMC6449538 DOI: 10.1007/s12602-018-9444-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Acinetobacter baumannii is one of the most challenging pathogens, on account of its predisposition to develop resistance leading to severe, difficult-to-treat infections. As these bacteria are more usually isolated from nosocomial infections, the new therapeutic options are demanded. Antimicrobial peptides (AMPs) are compounds likely to find application in the treatment of A. baumannii. These compounds exhibit a wide spectrum of antimicrobial activity and were found to be effective against biofilm. In this study, eight AMPs, namely aurein 1.2, CAMEL, citropin 1.1., LL-37, omiganan, r-omiganan, pexiganan, and temporin A, were tested for their antimicrobial activity. A reference strain of A. baumannii ATCC 19606 was used. Antimicrobial assays included determination of the minimum inhibitory concentration and the minimum biofilm eradication concentration. Considering the fact that the majority of A. baumannii infections are associated with mechanical ventilation and the use of indwelling devices, the activity against biofilm was assessed on both a polystyrene surface and tracheal tube fragments. In addition, cytotoxicity (HaCaT) was determined and in vitro selectivity index was calculated.
Collapse
Affiliation(s)
- Maciej Jaśkiewicz
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland.
| | - Damian Neubauer
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | - Kamil Kazor
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | - Sylwia Bartoszewska
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| | - Wojciech Kamysz
- Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Gdansk, Poland
| |
Collapse
|
12
|
Meskini M, Esmaeili D. The study of formulated Zoush ointment against wound infection and gene expression of virulence factors Pseudomonas aeruginosa. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 18:185. [PMID: 29903005 PMCID: PMC6003004 DOI: 10.1186/s12906-018-2251-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 06/07/2018] [Indexed: 01/29/2023]
Abstract
BACKGROUND The outbreak of MDR and XDR strains of Pseudomonas aeruginosa and increased resistance to infection in burn patients recommend the issue of infection control. In this research, we study ZOUSH herbal ointment for gene silencing of Pseudomonas aeruginosa. METHODS The herbal ZOUSH ointment was formulated by alcoholic extracts of plants Satureja khuzestaniea, Zataria multiflora, Mentha Mozaffariani Jamzad, honey, and polyurethane. The MIC and disk diffusion tests were examined by single, binary, tertiary and five compounds. Three-week-old mice were considered to be second-degree infections by Pseudomonas aeruginosa. During the interval of 5 days, cultures were done from the liver, blood, and wound by four consecutive quarters and counting of Pseudomonas aeruginosa was reported in the liver. In this study, silver sulfadiazine ointments and Akbar were used as a positive control. The gene gyrA reference was used as the control. Real-time RT-PCR results were evaluated based on Livak as the comparative Ct method. RESULTS The In vitro results indicated that wound infection was improved by healing wound size in the treatment groups compared to control treatment group. In this research, the changes in gene expression were evaluated by molecular technique Real-time RT-PCR. The results showed downregulation exoS, lasA, and lasB after treatment with ZOUSH ointment. SPSS Analyses showed that reduction of expressions in genes exoS, lasA and lasB after treatment with ZOUSH ointment were significantly meaningful (p < 0.05). CONCLUSION Our study showed that ZOUSH ointment has the positive effect for gene silencing Pseudomonas aeruginosa in the mouse model with the second-degree burn. The positive effects decreased in the number of bacteria by reducing the expression of virulence bacteria genes as exoS, lasA and lasB and improvement of wound healing.
Collapse
Affiliation(s)
- Maryam Meskini
- Department of Microbiology and Applied Microbiology Research Center, Systems Biology and Poisonings Institute and Department Of Microbiology, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Davoud Esmaeili
- Department of Microbiology and Applied Microbiology Research Center, Systems Biology and Poisonings Institute and Department Of Microbiology, Baqiyatallah University of Medical Sciences, Tehran, Iran
| |
Collapse
|
13
|
Park GC, Choi JA, Jang SJ, Jeong SH, Kim CM, Choi IS, Kang SH, Park G, Moon DS. In Vitro Interactions of Antibiotic Combinations of Colistin, Tigecycline, and Doripenem Against Extensively Drug-Resistant and Multidrug-Resistant Acinetobacter baumannii. Ann Lab Med 2017; 36:124-30. [PMID: 26709259 PMCID: PMC4713845 DOI: 10.3343/alm.2016.36.2.124] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/01/2015] [Accepted: 11/11/2015] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Acinetobacter baumannii infections are difficult to treat owing to the emergence of various antibiotic resistant isolates. Because treatment options are limited for multidrug-resistant (MDR) A. baumannii infection, the discovery of new therapies, including combination therapy, is required. We evaluated the synergistic activity of colistin, doripenem, and tigecycline combinations against extensively drug-resistant (XDR) A. baumannii and MDR A. baumannii. METHODS Time-kill assays were performed for 41 XDR and 28 MDR clinical isolates of A. baumannii by using colistin, doripenem, and tigecycline combinations. Concentrations representative of clinically achievable levels (colistin 2 μg/mL, doripenem 8 μg/mL) and achievable tissue levels (tigecycline 2 μg/mL) for each antibiotic were used in this study. RESULTS The colistin-doripenem combination displayed the highest rate of synergy (53.6%) and bactericidal activity (75.4%) in 69 clinical isolates of A. baumannii. Among them, the-doripenem-tigecycline combination showed the lowest rate of synergy (14.5%) and bactericidal activity (24.6%). The doripenem-tigecycline combination showed a higher antagonistic interaction (5.8%) compared with the colistin-tigecycline (1.4%) combination. No antagonism was observed for the colistin-doripenem combination. CONCLUSIONS The colistin-doripenem combination is supported in vitro by the high rate of synergy and bactericidal activity and lack of antagonistic reaction in XDR and MDR A. baumannii. It seems to be necessary to perform synergy tests to determine the appropriate combination therapy considering the antagonistic reaction found in several isolates against the doripenem-tigecycline and colistin-tigecycline combinations. These findings should be further examined in clinical studies.
Collapse
Affiliation(s)
- Gyun Cheol Park
- Department of Laboratory Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Ji Ae Choi
- Research Center for Resistant Cells, College of Medicine, Chosun University, Gwangju, Korea
| | - Sook Jin Jang
- Department of Laboratory Medicine, College of Medicine, Chosun University, Gwangju, Korea.,Research Center for Resistant Cells, College of Medicine, Chosun University, Gwangju, Korea.
| | - Seok Hoon Jeong
- Department of Laboratory Medicine and Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.
| | - Choon-Mee Kim
- Premedical Science, College of Medicine, Chosun University, Gwangju, Korea
| | - In Sun Choi
- Department of Laboratory Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Seong Ho Kang
- Department of Laboratory Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Geon Park
- Department of Laboratory Medicine, College of Medicine, Chosun University, Gwangju, Korea
| | - Dae Soo Moon
- Department of Laboratory Medicine, College of Medicine, Chosun University, Gwangju, Korea
| |
Collapse
|
14
|
Holloway KP, Rouphael NG, Wells JB, King MD, Blumberg HM. Polymyxin B and Doxycycline Use in Patients with Multidrug-Resistant Acinetobacter baumannii Infections in the Intensive Care Unit. Ann Pharmacother 2016; 40:1939-45. [PMID: 17018688 DOI: 10.1345/aph.1h353] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Background: Multidrug-resistant Acinetobacter baumannii (MDR-Ab) has emerged as an increasingly problematic cause of hospital-acquired infections in the intensive care unit (ICU). MDR-Ab is resistant to most standard antimicrobials but often retains susceptibility to polymyxin B and doxycycline. Objective: To evaluate the efficacy and toxicity of polymyxin B and doxycycline in the treatment of MDR-Ab infections. Methods: A retrospective chart review was conducted between March 2002 and May 2005 in patients who received doxycycline or polymyxin B for treatment of MDR-Ab infections in ICUs within Grady Memorial Hospital, Atlanta, GA. Results: Thirty-seven patients with MDR-Ab infections were treated with polymyxin B or doxycycline. Median age was 41 years and median ICU length of stay was 18 days prior to acquisition of MDR-Ab. Clinical cure was observed in 22 of 29 (76%) evaluable patients treated with polymyxin B and 2 of 4 (50%) patients treated with doxycycline. In patients with follow-up cultures, microbiological cure was observed in 17 of 21 (81%) patients treated with polymyxin B and 2 of 3 (67%) patients treated with doxycycline. Nephrotoxicity developed in 21% (7 of 33) of patients who received polymyxin B. Neurotoxicity was observed in 2 (6%) patients who received polymyxin B. No adverse reactions were observed with doxycycline. Overall, crude mortality was 27% (9 of 33) and 75% (3 of 4) among those who received polymyxin B and doxycycline, respectively. Three (9%) deaths were attributed to polymyxin B treatment failure, and no deaths were attributed to doxycycline treatment failure. Conclusions: Polymyxin B was effectively used to treat a substantial proportion of critically ill patients with MDR-Ab infection and was associated with a similar rate of nephrotoxicity as previously reported. Doxycycline monotherapy was used in a limited number of patients for the treatment of MDR-Ab; further evaluation of its efficacy in larger numbers of patients is warranted.
Collapse
Affiliation(s)
- Katherine P Holloway
- Internal Medicine, Department of Clinical and Administrative Sciences, Mercer University College of Pharmacy and Health Sciences, Atlanta, GA 30341-4155, USA.
| | | | | | | | | |
Collapse
|
15
|
Esterly JS, Richardson CL, Eltoukhy NS, Qi C, Scheetz MH. Genetic Mechanisms of Antimicrobial Resistance of Acinetobacter baumannii. Ann Pharmacother 2015; 45:218-28. [PMID: 21304033 DOI: 10.1345/aph.1p084] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE To summarize published data identifying known genetic mechanisms of antibiotic resistance in Acinetobacter baumannii and the correlating phenotypic expression of antibiotic resistance. DATA SOURCES MEDLINE databases (1966-July 15, 2010) were searched to identify original reports of genetic mechanisms of antibiotic resistance in A. baumannii. DATA SYNTHESIS Numerous genetic mechanisms of resistance to multiple classes of antibiotics are known to exist in A. baumannii, a gram-negative bacterium increasingly implicated in nosocomial infections. Mechanisms may be constitutive or acquired via plasmids, integrons, and transposons. Methods of resistance include enzymatic modification of antibiotic molecules, modification of antibiotic target sites, expression of efflux pumps, and downregulation of cell membrane porin channel expression. Resistance to β-lactams appears to be primarily caused by β-lactamase production, including extended spectrum β-lactamases (b/aTEM, blaSHV, b/aTX-M,b/aKPC), metallo-β-lactamases (blaMP, blaVIM, bla, SIM), and most commonly, oxacillinases (blaOXA). Antibiotic target site alterations confer resistance to fluoroquinolones (gyrA, parC) and aminoglycosides (arm, rmt), and to a much lesser extent, β-lactams. Efflux pumps (tet, ade, abe) contribute to resistance against β-lactams, tetracyclines, fluoroquinolones, and aminoglycosides. Finally, porin channel deletion (carO, oprD) appears to contribute to β-lactam resistance and may contribute to rarely seen polymyxin resistance. Of note, efflux pumps and porin deletions as solitary mechanisms may not render clinical resistance to A. baumannii. CONCLUSIONS A. baumannii possesses copious genetic resistance mechanisms. Knowledge of local genotypes and expressed phenotypes for A. baumannii may aid clinicians more than phenotypic susceptibilities reported in large epidemiologic studies.
Collapse
Affiliation(s)
- John S Esterly
- John S Esterly PharmD BCPS, at time of writing, Infectious Diseases Pharmacotherapy Fellow, Department of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago, Downers Grove, IL; now, Assistant Professor of Pharmacy Practice, College of Pharmacy, Chicago State University, Chicago, IL; Infectious Diseases Pharmacist, Northwestern Memorial Hospital, Chicago
| | - Chad L Richardson
- Chad L Richardson PharmD, at time of writing, Infectious Diseases Pharmacotherapy Resident, Department of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago; now, Solid Organ Transplant Pharmacist, Northwestern Memorial Hospital
| | - Noha S Eltoukhy
- Noha S Eltoukhy PharmD BCPS, at time of writing, Infectious Diseases Pharmacy Resident, Department of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago; Rush University Medical Center, Chicago; now, Infectious DIseases Clinical Pharmacy Specialist, St. Mary Medical Center, Langhorne, PA
| | - Chao Qi
- Chao Qi PhD, Assistant Professor of Pathology, Feinberg School of Medicine, Northwestern University; Assistant Director, Clinical Microbiology Laboratory, Northwestern Memorial Hospital, Chicago
| | - Marc H Scheetz
- Marc H Scheetz PharmD MSc BCPS, Assistant Professor of Pharmacy Practice, College of Pharmacy, Midwestern University Chicago; Infectious Diseases Pharmacist, Northwestern Memorial Hospital
| |
Collapse
|
16
|
Rosales-Reyes R, Alcántar-Curiel MD, Jarillo-Quijada MD, Gayosso-Vázquez C, Morfin-Otero MDR, Rodríguez-Noriega E, Santos-Preciado JI. Biofilm Formation and Susceptibility to Polymyxin B by a Highly Prevalent Clone of Multidrug-Resistant Acinetobacter baumannii from a Mexican Tertiary Care Hospital. Chemotherapy 2015; 61:8-14. [PMID: 26536333 DOI: 10.1159/000440605] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 08/24/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND Acinetobacter baumannii has emerged as a major cause of hospital-associated infections with increased morbidity and mortality among those affected. METHODS A total of 85 isolates of a highly prevalent multidrug-resistant clone, identified during the period 2007-2011, were analyzed for biofilm formation on a polystyrene surface. The minimal inhibitory concentration was determined by the Sensititre System, the agar disk diffusion method and then read by means of the BIOMIC system and serial dilutions on Müller-Hinton agar. RESULTS In this study, covering a period of 5 years (2007-2011), we demonstrate that a particular clone emerged as the most prevalent, with an associated lethality of 28.2%. We demonstrate that 92.9% of strains corresponding to this clone are biofilm producers. Our results also demonstrate that all isolates were 100% susceptible to polymyxin B. CONCLUSION Our study suggests that the high prevalence and lethality of this multidrug-resistant clone of A. baumannii and its persistence over close to 5 years in a Mexican tertiary hospital environment can be explained in part by the ability of these clinical isolates of A. baumannii to form biofilms.
Collapse
|
17
|
In vitro antimicrobial synergy studies of carbapenem-resistant Acinetobacter baumannii isolated from intensive care units of a tertiary care hospital in Egypt. J Infect Public Health 2015; 8:593-602. [DOI: 10.1016/j.jiph.2015.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 04/21/2015] [Accepted: 05/02/2015] [Indexed: 11/23/2022] Open
|
18
|
Lin L, Nonejuie P, Munguia J, Hollands A, Olson J, Dam Q, Kumaraswamy M, Rivera H, Corriden R, Rohde M, Hensler ME, Burkart MD, Pogliano J, Sakoulas G, Nizet V. Azithromycin Synergizes with Cationic Antimicrobial Peptides to Exert Bactericidal and Therapeutic Activity Against Highly Multidrug-Resistant Gram-Negative Bacterial Pathogens. EBioMedicine 2015; 2:690-8. [PMID: 26288841 PMCID: PMC4534682 DOI: 10.1016/j.ebiom.2015.05.021] [Citation(s) in RCA: 201] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 05/21/2015] [Accepted: 05/21/2015] [Indexed: 12/22/2022] Open
Abstract
Antibiotic resistance poses an increasingly grave threat to the public health. Of pressing concern, rapid spread of carbapenem-resistance among multidrug-resistant (MDR) Gram-negative rods (GNR) is associated with few treatment options and high mortality rates. Current antibiotic susceptibility testing guiding patient management is performed in a standardized manner, identifying minimum inhibitory concentrations (MIC) in bacteriologic media, but ignoring host immune factors. Lacking activity in standard MIC testing, azithromycin (AZM), the most commonly prescribed antibiotic in the U.S., is never recommended for MDR GNR infection. Here we report a potent bactericidal action of AZM against MDR carbapenem-resistant isolates of Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. This pharmaceutical activity is associated with enhanced AZM cell penetration in eukaryotic tissue culture media and striking multi-log-fold synergies with host cathelicidin antimicrobial peptide LL-37 or the last line antibiotic colistin. Finally, AZM monotherapy exerts clear therapeutic effects in murine models of MDR GNR infection. Our results suggest that AZM, currently ignored as a treatment option, could benefit patients with MDR GNR infections, especially in combination with colistin. Standard MIC testing conditions overlook a potent activity of azithromycin vs. multidrug-resistant Gram-negative bacteria. Colistin and endogenous host defense peptide LL-37 markedly potentiate azithromycin penetration into bacterial cells. Azithromycin reduced bacterial load and mortality in mouse models of multidrug-resistant Gram-negative infection.
Collapse
Affiliation(s)
- Leo Lin
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Poochit Nonejuie
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jason Munguia
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew Hollands
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joshua Olson
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Quang Dam
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Monika Kumaraswamy
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Heriberto Rivera
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla CA 92093, USA
| | - Ross Corriden
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Mary E Hensler
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael D Burkart
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla CA 92093, USA
| | - Joe Pogliano
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - George Sakoulas
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA ; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA ; Rady Children's Hospital, San Diego, CA 92123, USA
| |
Collapse
|
19
|
Valencia R, Arroyo LA, Conde M, Aldana JM, Torres MJ, Fernández-Cuenca F, Garnacho-Montero J, Cisneros JM, Ortiz C, Pachón J, Aznar J. Nosocomial Outbreak of Infection With Pan–Drug-ResistantAcinetobacter baumanniiin a Tertiary Care University Hospital. Infect Control Hosp Epidemiol 2015; 30:257-63. [DOI: 10.1086/595977] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Objective.TO describe what is, to our knowledge, the first nosocomial outbreak of infection with pan–drug-resistant (including colistin-resistant)Acinetobacter baumannii,to determine the risk factors associated with these types of infections, and to determine their clinical impact.Design.Nested case-control cohort study and a clinical-microbiological study.Setting.A 1,521-bed tertiary care university hospital in Seville, Spain.Patients.Case patients were inpatients who had a pan-drug-resistantA. baumanniiisolate recovered from a clinical or surveillance sample obtained at least 48 hours after admission to an intensive care unit (ICU) during the time of the epidemic outbreak. Control patients were patients who were admitted to any of the “boxes” (ie, rooms that partition off a distinct area for a patient's bed and the equipment needed to care for the patient) of an ICU for at least 48 hours during the time of the epidemic outbreak.Results.All the clinical isolates had similar antibiotic susceptibility patterns (ie, they were resistant to all the antibiotics tested, including Colistin), and, on the basis of repetitive extragenic palindromic-polymerase chain reaction, it was determined that all of them were of the same clone. The previous use of quinolones and glycopeptides and an ICU stay were associated with the acquisition of infection or colonization with pan-drug-resistant A.baumannii.To control this outbreak, we implemented the following multicomponent intervention program: the performance of environmental decontamination of the ICUs involved, an environmental survey, a revision of cleaning protocols, active surveillance for colonization with pan-drug-resistantA. baumannii,educational programs for the staff, and the display of posters that illustrate contact isolation measures and antimicrobial use recommendations.Conclusions.We were not able to identify the common source for these cases of infection, but the adopted measures have proven to be effective at controlling the outbreak.
Collapse
|
20
|
Karaoglan I, Zer Y, Bosnak VK, Mete AO, Namiduru M. In vitro synergistic activity of colistin with tigecycline or β-lactam antibiotic/β-lactamase inhibitor combinations against carbapenem-resistant Acinetobacter baumannii. J Int Med Res 2014; 41:1830-7. [PMID: 24265334 DOI: 10.1177/0300060513496172] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE Nosocomial infection caused by carbapenem-resistant Acinetobacter baumannii is a worldwide problem and treatment options remain controversial. This study investigated the in vitro effect of various antibiotic combinations against carbapenem-resistant A. baumannii strains. METHODS Antibiotic susceptibility of A. baumannii strains was analysed. In vitro synergistic efficacy of colistin combined with tigecycline, cefoperazone/sulbactam or piperacillin/tazobactam was tested against carbapenem-resistant A. baumannii strains. Synergy studies were performed using an eplisometer test-strip method. RESULTS Of the 50 carbapenem-resistant A. baumannii strains tested, 96% were susceptible to colistin and 64% were susceptible to tigecycline. Colistin-tigecycline, colistin-cefoperazone/sulbactam and colistin-piperacillin/tazobactam combinations were found to have synergistic effects against six (12%), two (4%), and one (2%), respectively, of the strains tested. CONCLUSIONS Colistin combined with tigecycline, cefoperazone/sulbactam or piperacillin/tazobactam revealed synergistic effects in some carbapenem-resistant A. baumannii strains. These results, together with the shortage of treatment options and the risk of developing resistance to colistin, suggest that clinicians should use colistin combined with other antibiotics or β-lactamase inhibitors when treating carbapenem-resistant A. baumannii infection.
Collapse
Affiliation(s)
- Ilkay Karaoglan
- Department of Infectious Diseases and Clinical Microbiology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey
| | | | | | | | | |
Collapse
|
21
|
Perween N, Sehgal S, Prakash SK. Geographical patterns in antimicrobial resistance of acinetobacter in clinical isolates. J Clin Diagn Res 2014; 8:DC10-2. [PMID: 24959441 DOI: 10.7860/jcdr/2014/8590.4235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 02/26/2014] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Acinetobacter spp. has emerged as a threat to the healthcare workers throughout the globe, owing to its property of multidrug resistance. The aim of the present study was to evaluate the antimicrobial resistance patterns of Acinetobacter spp. among indoor and out patients in our hospital and compare the resistance patterns in India and abroad. MATERIALS AND METHODS In this retrospective study, which was carried out between Over a period of one year, a total of 5593 clinical specimens of pus and purulent fluids were examined and antimicrobial resistance pattern for Acinetobacter spp. using Modified Stoke's were evaluated. Also a comparison was done with the other similar studies. STATISTICAL ANALYSIS Using the proportions of sensitive and resistant, the statistical analysis was done. The total, mean and percentage were calculated by using SPSS. RESULTS A high level of antimicrobial multidrug-resistance was found in almost all the clinical isolate. Our study was also found to be concordant with the results of other studies. CONCLUSION There is an emerging need for identification of the genes and mechanisms for multidrug resistance among Acinetobacter spp.
Collapse
Affiliation(s)
- Naz Perween
- Senior Resident, Department of Microbiology, Maulana Azad Medical College , New Delhi, India
| | - Sonal Sehgal
- Post Graduate Student,Department of Microbiology, Maulana Azad Medical College , New Delhi, India
| | - S Krishna Prakash
- Director Professor, Department of Microbiology, Maulana Azad Medical College , New Delhi, India
| |
Collapse
|
22
|
Dash M, Padhi S, Pattnaik S, Mohanty I, Misra P. Frequency, risk factors, and antibiogram of Acinetobacter species isolated from various clinical samples in a tertiary care hospital in Odisha, India. Avicenna J Med 2013; 3:97-102. [PMID: 24327968 PMCID: PMC3841484 DOI: 10.4103/2231-0770.120501] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND For the past two decades, Acinetobacter spp. have emerged as an important pathogen globally in various infections. OBJECTIVES This study was conducted to determine the frequency, risk factors, and antibiotic resistance pattern of Acinetobacter spp. from various clinical samples. MATERIALS AND METHODS This retrospective, hospital record-based, cross-sectional study included a total of 8749 clinical samples collected from patients at a tertiary care hospital in Odisha, India from July 2010 to December 2012. The samples were processed and identified by standard protocol. The Acinetobacter isolates were tested for antibiotic resistance by Kirby-Bauer disk diffusion method [according to the Clinical and Laboratory Standards Institute (CLSI) guidelines]. RESULTS From 8749 clinical samples, 4589 (52.5%) yielded significant growth and only 137 (3%, 137/4589) Acinetobacter spp. were isolated. Maximum (56.9%) isolates were obtained from pus/swab, followed by blood (13.1%) and urine (12.4%). Elderly age, being inpatients, longer duration of stay in the hospital, associated co-morbidity, and invasive procedure were found to be significant risk factors in the setup investigated (P is less than 0.05). Out of 137 isolates, 75 (54.7%) were resistant to more than three classes of antibiotics (multidrug resistant) and 8 (5.8%) were resistant to all commonly used antibiotics (pan-drug resistant). Majority of the isolates were sensitive to imipenem, meropenem, and piperacillin/tazobactam, and showed resistance rates of 19%, 22%, and 23%, respectively. All eight pan-drug resistant isolates were 100% sensitive to colistin. CONCLUSION This hospital-based epidemiological data will help to implement better infection control strategies and improve the knowledge of antibiotic resistance patterns in our region.
Collapse
Affiliation(s)
- Muktikesh Dash
- Department of Microbiology, Maharaja Krushna Chandra Gajapati Medical College and Hospital, Berhampur University, Odisha, India
| | - Sanghamitra Padhi
- Department of Microbiology, Maharaja Krushna Chandra Gajapati Medical College and Hospital, Berhampur University, Odisha, India
| | - Swetlana Pattnaik
- Department of Microbiology, Maharaja Krushna Chandra Gajapati Medical College and Hospital, Berhampur University, Odisha, India
| | - Indrani Mohanty
- Department of Microbiology, Maharaja Krushna Chandra Gajapati Medical College and Hospital, Berhampur University, Odisha, India
| | - Pooja Misra
- Department of Radiodiagnosis, Maharaja Krushna Chandra Gajapati Medical College and Hospital, Berhampur University, Odisha, India
| |
Collapse
|
23
|
Adnan S, Paterson DL, Lipman J, Roberts JA. Ampicillin/sulbactam: its potential use in treating infections in critically ill patients. Int J Antimicrob Agents 2013; 42:384-9. [PMID: 24041466 DOI: 10.1016/j.ijantimicag.2013.07.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 07/23/2013] [Accepted: 07/23/2013] [Indexed: 01/21/2023]
Abstract
The purpose of this paper was to review the potential utility of ampicillin/sulbactam (SAM) as a therapy for serious infections in critically ill patients. Data for this review were identified by searches of PubMed and of the reference lists of the included articles. We found that SAM appears to have a number of characteristics that support its use in the treatment of serious infections in critically ill patients. SAM demonstrates extensive penetration into many infection sites, supporting its use in a wide range of infection types. Microbiologically, sulbactam has strong intrinsic antibiotic activity against multidrug-resistant (MDR) bacteria, including Acinetobacter baumannii, which supports its use for the treatment of infections mediated by this pathogen. Of some concern, there have been reports showing a decline in susceptibility of some bacteria to SAM. As such, use of lower doses (4/2g/day), particularly for MDR A. baumannii, has been linked with a 30% reduced success rate in critically ill patients. The therapeutic challenges for ensuring achievement of optimal dosing of SAM result partly from bacterial susceptibility but also from the pharmacokinetic (PK) alterations common to β-lactam agents in critical illness. These PK changes are likely to reduce the ability of standard dosing to achieve the concentrations observed in non-critically ill patients. Optimisation of therapy may be more likely with the use of higher doses, administration by 4h infusion or by combination therapy, particularly for the treatment of infections caused by MDR pathogens.
Collapse
Affiliation(s)
- Syamhanin Adnan
- Burns, Trauma and Critical Care Research Centre, The University of Queensland, Brisbane, Australia; University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia.
| | | | | | | |
Collapse
|
24
|
Cation concentration variability of four distinct Mueller-Hinton agar brands influences polymyxin B susceptibility results. J Clin Microbiol 2012; 50:2414-8. [PMID: 22553247 DOI: 10.1128/jcm.06686-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polymyxins have been the only alternative therapeutic option for the treatment of serious infections caused by multidrug-resistant Acinetobacter baumannii or Pseudomonas aeruginosa isolates. For this reason, it is of crucial importance that susceptibility tests provide accurate results when testing these drug-pathogen combinations. In this study, the effect of cation concentration variability found on different commercial brands of Mueller-Hinton agar (MHA) for testing polymyxin B susceptibility was evaluated. The polymyxin B susceptibilities determined using Etest and disk diffusion were compared to those determined by the CLSI reference broth microdilution method. In general, the polymyxin B MIC values were higher when determined by Etest than when determined by broth microdilution against both A. baumannii and P. aeruginosa isolates. A high very major error rate (10%) was observed, as well as a trend toward lower MICs, compared to those determined by broth microdilution when the Merck MHA was tested by Etest. Poor essential agreement rates (10 to 70%) were observed for P. aeruginosa when all MHA brands were tested by Etest. Although an excellent categorical agreement rate (100%) was seen between the disk diffusion and broth microdilution methods for P. aeruginosa, larger zones of inhibition were shown obtained using the Merck MHA. The high cation concentration variability found for the MHA brands tested correlated to the low accuracy, and discrepancies in the polymyxin B MICs were determined by Etest method, particularly for P. aeruginosa isolates.
Collapse
|
25
|
Mohamed NM, Youssef AA. In VitroActivity of Tigecycline and Comparators Against Gram-Negative Bacteria Isolated from a Tertiary Hospital in Alexandria, Egypt. Microb Drug Resist 2011; 17:489-95. [DOI: 10.1089/mdr.2010.0195] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Nelly M. Mohamed
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Alaa A.F. Youssef
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| |
Collapse
|
26
|
Smani Y, Domínguez-Herrera J, Pachón J. Rifampin Protects Human Lung Epithelial Cells Against Cytotoxicity Induced by Clinical Multi and Pandrug-resistant Acinetobacter baumannii. J Infect Dis 2011; 203:1110-9. [DOI: 10.1093/infdis/jiq159] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
27
|
Neonakis IK, Spandidos DA, Petinaki E. Confronting multidrug-resistant Acinetobacter baumannii: a review. Int J Antimicrob Agents 2010; 37:102-9. [PMID: 21130607 DOI: 10.1016/j.ijantimicag.2010.10.014] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 10/08/2010] [Indexed: 11/27/2022]
Abstract
Multidrug-resistant Acinetobacter baumannii (MDR-AB) infections are difficult to treat owing to the extremely limited armamentarium. The present review reports all available treatment options against MDR-AB, including single molecules, combination schemes, and alternative modes of antimicrobial administration. Additionally, a group of recently reported peptides with anti-MDR-AB activity is described.
Collapse
Affiliation(s)
- Ioannis K Neonakis
- Department of Microbiology, Medical School, University of Thessaly, Larissa, Greece.
| | | | | |
Collapse
|
28
|
Kiratisin P, Apisarnthanarak A, Kaewdaeng S. Synergistic activities between carbapenems and other antimicrobial agents against Acinetobacter baumannii including multidrug-resistant and extensively drug-resistant isolates. Int J Antimicrob Agents 2010; 36:243-6. [DOI: 10.1016/j.ijantimicag.2010.04.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 04/07/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
|
29
|
Urban C, Mariano N, Rahal JJ, Tay E, Ponio C, Koprivnjak T, Weiss J. Polymyxin B-Resistant Acinetobacter baumannii Clinical Isolate Susceptible to Recombinant BPI and Cecropin P1. Antimicrob Agents Chemother 2010; 45:994-5. [PMID: 16557680 PMCID: PMC90414 DOI: 10.1128/aac.45.3.994-995.2001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- C Urban
- Infectious Diseases Section The New York Hospital Medical Center of Queens Flushing, New York
| | | | | | | | | | | | | |
Collapse
|
30
|
Hernan RC, Karina B, Gabriela G, Marcela N, Carlos V, Angela F. Selection of colistin-resistant Acinetobacter baumannii isolates in postneurosurgical meningitis in an intensive care unit with high presence of heteroresistance to colistin. Diagn Microbiol Infect Dis 2009; 65:188-91. [DOI: 10.1016/j.diagmicrobio.2009.05.019] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2009] [Revised: 05/16/2009] [Accepted: 05/31/2009] [Indexed: 10/20/2022]
|
31
|
Sung H, Choi SJ, Yoo S, Kim MN. [In vitro antimicrobial synergy against imipenem-resistant Acinetobacter baumannii]. Korean J Lab Med 2008; 27:111-7. [PMID: 18094561 DOI: 10.3343/kjlm.2007.27.2.111] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Most imipenem-resistant Acinetobacter baumannii (IRAB) isolates are multiresistant, leaving few options for an effective antimicrobial therapy. We purposed to select possible candidates for the combinations of antimicrobials that are synergistic in vitro for inhibitory or bactericidal activities against IRAB and evaluate the usefulness of double disk synergy test (DDS) in predicting synergistic bactericidal activity. METHODS Fifty-five IRAB isolates recovered from patients during the period from August 1999 to November 2000 were tested for susceptibilities to amikacin, gentamicin, tobramycin, piperacillin, piperacillin/tazobactam, cefotaxime, cefepime, cefoperazone/sulbactam (C/S), imipenem, meropenem, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole, chloramphenicol, minocycline, and colistin by the Clinical and Laboratory Standard Institute agar dilution method. Three isolates showing different susceptibility profiles were tested for antimicrobial synergy by DDS and then by timekill study (TKS) using DDS-positive combinations. RESULTS Colistin, C/S, and minocycline were active in 50 (90.9%), 50, and 44 (80.0%) isolates, respectively, and all the other drugs were active in less than 20% of isolates. Minocycline-imipenem, minocycline-C/S, minocycline-amikacin, imipenem-tobramycin, C/S-amikacin, and C/S-tobramycin combinations showed synergistic inhibitory or bactericidal activity by TKS when the same combinations were synergistic in DDS; however, C/S-imipenem was found synergistic on DDS, but not by TKS. CONCLUSIONS Colistin, C/S, and minocycline were relatively active against IRAB. DDS might help predict the synergistic antimicrobial effect of TKS if one of the combinations was susceptible.
Collapse
Affiliation(s)
- Heungsup Sung
- Department of Laboratory Medicine, University of Ulsan College of Medicine and Asan Medical Center, Seoul, Korea
| | | | | | | |
Collapse
|
32
|
Abstract
Acinetobacter baumannii has emerged as a highly troublesome pathogen for many institutions globally. As a consequence of its immense ability to acquire or upregulate antibiotic drug resistance determinants, it has justifiably been propelled to the forefront of scientific attention. Apart from its predilection for the seriously ill within intensive care units, A. baumannii has more recently caused a range of infectious syndromes in military personnel injured in the Iraq and Afghanistan conflicts. This review details the significant advances that have been made in our understanding of this remarkable organism over the last 10 years, including current taxonomy and species identification, issues with susceptibility testing, mechanisms of antibiotic resistance, global epidemiology, clinical impact of infection, host-pathogen interactions, and infection control and therapeutic considerations.
Collapse
|
33
|
Bantar C, Schell C, Posse G, Limansky A, Ballerini V, Mobilia L. Comparative time-kill study of doxycycline, tigecycline, sulbactam, and imipenem against several clones of Acinetobacter baumannii. Diagn Microbiol Infect Dis 2008; 61:309-14. [PMID: 18375084 DOI: 10.1016/j.diagmicrobio.2008.02.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Revised: 02/08/2008] [Accepted: 02/24/2008] [Indexed: 02/06/2023]
Abstract
To assess potential alternative options for the treatment of infections caused by Acinetobacter baumannii, we performed time-kill studies of doxycycline and tigecycline using several isolates recovered from patients residing in 10 different cities in Argentina. Imipenem and sulbactam were also included for comparison purposes. Eleven isolates representing 5 distinctive clones, or isolates with different susceptibility patterns within the same clone, were selected. Tubes containing cation-supplemented Mueller-Hinton broth with and without antibiotics were seeded with a log-phase inoculum of roughly 5 x 10(5) CFU/mL. By using the viable counts determined at 2-, 4-, 6-, 8-, and 24-h intervals after inoculation, a 24-h time-kill curve was constructed for each isolate. No bactericidal activity (defined as a >or=3-log(10) CFU/mL decrease in the viable cell counts with respect to the original inoculum) was observed at any time with sulbactam (4 microg/mL) or tigecycline (1 microg/mL), whereas low bactericidal rate (18% of the isolates) was shown for doxycycline (1 microg/mL) and sulbactam (16 microg/mL) after 24 h of incubation. Doxycycline (4 microg/mL) and tigecycline (8 microg/mL) displayed bactericidal activity at 24 h of incubation against 36% and 54% of the isolates, respectively, including the carbapenem-resistant isolate. Corresponding values for imipenem (1 and 4 microg/mL) against the 10 carbapenem-susceptible isolates were 60% and 90%, respectively. The present study confirms the in vitro efficacy of imipenem against A. baumannii, suggests that doxycycline could be a suitable, cost-effective, alternative option in some instances, and sheds light on the potential role of tigecycline in the treatment of infections with this organism.
Collapse
Affiliation(s)
- Carlos Bantar
- Laboratorio Domingo I. Nanni, Paraná, Entre Ríos, Argentina.
| | | | | | | | | | | |
Collapse
|
34
|
|
35
|
van der Heijden IM, Levin AS, De Pedri EH, Fung L, Rossi F, Duboc G, Barone AA, Costa SF. Comparison of disc diffusion, Etest and broth microdilution for testing susceptibility of carbapenem-resistant P. aeruginosa to polymyxins. Ann Clin Microbiol Antimicrob 2007; 6:8. [PMID: 17697363 PMCID: PMC2018696 DOI: 10.1186/1476-0711-6-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2007] [Accepted: 08/15/2007] [Indexed: 11/24/2022] Open
Abstract
Background Considering the increasing use of polymyxins to treat infections due to multidrug resistant Gram-negative in many countries, it is important to evaluate different susceptibility testing methods to this class of antibiotic. Methods Susceptibility of 109 carbapenem-resistant P. aeruginosa to polymyxins was tested comparing broth microdilution (reference method), disc diffusion, and Etest using the new interpretative breakpoints of Clinical and Laboratory Standards Institute. Results Twenty-nine percent of isolates belonged to endemic clone and thus, these strains were excluded of analysis. Among 78 strains evaluated, only one isolate was resistant to polymyxin B by the reference method (MIC: 8.0 μg/mL). Very major and major error rates of 1.2% and 11.5% were detected comparing polymyxin B disc diffusion with the broth microdilution (reference method). Agreement within 1 twofold dilution between Etest and the broth microdilution were 33% for polymyxin B and 79.5% for colistin. One major error and 48.7% minor errors were found comparing polymyxin B Etest with broth microdilution and only 6.4% minor errors with colistin. The concordance between Etest and the broth microdilution (reference method) was respectively 100% for colistin and 90% for polymyxin B. Conclusion Resistance to polymyxins seems to be rare among hospital carbapenem-resistant P. aeruginosa isolates over a six-year period. Our results showed, using the new CLSI criteria, that the disc diffusion susceptibility does not report major errors (false-resistant results) for colistin. On the other hand, showed a high frequency of minor errors and 1 very major error for polymyxin B. Etest presented better results for colistin than polymyxin B. Until these results are reproduced with a large number of polymyxins-resistant P. aeruginosa isolates, susceptibility to polymyxins should be confirmed by a reference method.
Collapse
Affiliation(s)
- Inneke M van der Heijden
- Laboratory of Medical Investigation 54, Hospital das Clinicas, University of São Paulo, Brazil
- Department of Infectious, Diseases of University of São Paulo, Brazil
| | - Anna S Levin
- Laboratory of Medical Investigation 54, Hospital das Clinicas, University of São Paulo, Brazil
- Department of Infectious, Diseases of University of São Paulo, Brazil
| | - Ewerton H De Pedri
- Laboratory of Medical Investigation 54, Hospital das Clinicas, University of São Paulo, Brazil
- Department of Infectious, Diseases of University of São Paulo, Brazil
| | - Liang Fung
- Laboratory of Medical Investigation 54, Hospital das Clinicas, University of São Paulo, Brazil
- Department of Infectious, Diseases of University of São Paulo, Brazil
| | - Flavia Rossi
- Laboratory of Microbiology of Hospital das Clínicas, University of São Paulo, Brazil
| | - Gisele Duboc
- Laboratory of Microbiology of Hospital das Clínicas, University of São Paulo, Brazil
| | - Antonio A Barone
- Laboratory of Microbiology of Hospital das Clínicas, University of São Paulo, Brazil
| | - Silvia F Costa
- Laboratory of Medical Investigation 54, Hospital das Clinicas, University of São Paulo, Brazil
- Department of Infectious, Diseases of University of São Paulo, Brazil
- Fernão Dias 158 apt 71, Pinheiros, São Paulo, SP, Brazil
| |
Collapse
|
36
|
Lahsoune M, Boutayeb H, Zerouali K, Belabbes H, El Mdaghri N. [Prevalence and in vitro antimicrobial susceptibility patterns of Acinetobacter baumannii strains in a Moroccan university hospital]. Med Mal Infect 2007; 37:828-31. [PMID: 17669611 DOI: 10.1016/j.medmal.2007.05.006] [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] [Received: 02/25/2007] [Accepted: 05/29/2007] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The aim of this study was to identify the clinical presentations and the current antimicrobial susceptibility of Acinetobacter baumannii. RESULTS We identified 754 strains especially from intensive care units (50.53%) between January 2003 and December 2005. Bronchial swabs and blood culture were prevalent. High-level resistance to betalactamines was noted: 91% to cefotaxime, 50.3% to ceftazidime, and 42.6% to imipenem. Aminoside resistance varied from 17.9% for netilmicine to 72.1% for gentamycin. The resistance rate to ciprofloxacine was 65.8%, and to trimethoprime-sulfamethoxazole 75.8%. In intensive care units, the antimicrobial resistance rate of A. baumannii was higher (p<0.05). CONCLUSION The resistance of A. baumannii to current antibiotics is alarming especially in intensive care units. An effective strategy against nosocomial infection is still necessary.
Collapse
Affiliation(s)
- M Lahsoune
- Laboratoire de microbiologie, faculté de médecine et de pharmacie, 19, rue Tarik-Bnou-Zyad, Casablanca, Maroc
| | | | | | | | | |
Collapse
|
37
|
Perez F, Hujer AM, Hujer KM, Decker BK, Rather PN, Bonomo RA. Global challenge of multidrug-resistant Acinetobacter baumannii. Antimicrob Agents Chemother 2007; 51:3471-84. [PMID: 17646423 PMCID: PMC2043292 DOI: 10.1128/aac.01464-06] [Citation(s) in RCA: 830] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Federico Perez
- Division of Infectious Diseases and HIV Medicine, University Hospitals, Case Medical Centers, Cleveland, OH, USA
| | | | | | | | | | | |
Collapse
|
38
|
Falagas ME, Bliziotis IA. Pandrug-resistant Gram-negative bacteria: the dawn of the post-antibiotic era? Int J Antimicrob Agents 2007; 29:630-6. [PMID: 17306965 DOI: 10.1016/j.ijantimicag.2006.12.012] [Citation(s) in RCA: 257] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Accepted: 12/11/2006] [Indexed: 10/23/2022]
Abstract
The evolving problem of antimicrobial resistance in Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae has led to the emergence of clinical isolates susceptible to only one class of antimicrobial agents and eventually to pandrug-resistant (PDR) isolates, i.e. resistant to all available antibiotics. We reviewed the available evidence from laboratory and clinical studies that reported on polymyxin-resistant and/or PDR P. aeruginosa, A. baumannii or K. pneumoniae clinical isolates. Eleven laboratory studies reported on isolates with resistance to polymyxins, three of which (including two surveillance studies) also included data regarding PDR isolates. In addition, two clinical studies (from Central and Southern Europe) reported on the clinical characteristics and outcomes of patients infected with PDR isolates. These data suggest that polymyxin-resistant or PDR P. aeruginosa, A. baumannii and K. pneumoniae clinical isolates are currently relatively rare. However, they have important global public health implications because of the therapeutic problems they pose. The fears for the dawn of a post-antibiotic era appear to be justified, at least for these three Gram-negative bacteria. We must increase our efforts to preserve the activity of available antibiotics, or at least expand as much as possible the period of their use, whilst intense research efforts should be focused on the development and introduction into clinical practice of new antimicrobial agents.
Collapse
Affiliation(s)
- Matthew E Falagas
- Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, 151 23 Marousi, Athens, Greece.
| | | |
Collapse
|
39
|
Falagas ME, Koletsi PK, Bliziotis IA. The diversity of definitions of multidrug-resistant (MDR) and pandrug-resistant (PDR) Acinetobacter baumannii and Pseudomonas aeruginosa. J Med Microbiol 2006; 55:1619-1629. [PMID: 17108263 DOI: 10.1099/jmm.0.46747-0] [Citation(s) in RCA: 295] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Different definitions of the terms multidrug-resistant (MDR) and pandrug-resistant (PDR) Acinetobacter baumannii and Pseudomonas aeruginosa have been used in the biomedical literature. The authors searched for relevant studies indexed in the PubMed database (01/2000-09/2005) to systematically examine the various definitions of MDR and PDR for these bacteria. Initially 107 retrieved relevant studies were reviewed. Ninety-two studies were further analysed, 50 of which focused on A. baumannii and 42 on P. aeruginosa. A considerable diversity of definitions of the terms MDR and PDR A. baumannii and P. aeruginosa was found. Of note, the term PDR was inappropriately used in all five studies that used it. The review reveals that various definitions have been used for the terms MDR and PDR A. baumannii and P. aeruginosa, a fact that causes confusion to researchers and clinicians. The authors believe that at least a widely accepted definition for PDR A. baumannii and P. aeruginosa should be uniformly used worldwide.
Collapse
Affiliation(s)
- Matthew E Falagas
- Department of Medicine, Tufts University School of Medicine, Boston, Massachusetts, USA
- Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, 151 23 Marousi, Athens, Greece
| | - Patra K Koletsi
- Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, 151 23 Marousi, Athens, Greece
| | - Ioannis A Bliziotis
- Alfa Institute of Biomedical Sciences (AIBS), 9 Neapoleos Street, 151 23 Marousi, Athens, Greece
| |
Collapse
|
40
|
Tong W, Wang R, Chai D, Li Z, Pei F. In vitro activity of cefepime combined with sulbactam against clinical isolates of carbapenem-resistant Acinetobacter spp. Int J Antimicrob Agents 2006; 28:454-6. [PMID: 16987639 DOI: 10.1016/j.ijantimicag.2006.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 06/26/2006] [Accepted: 06/28/2006] [Indexed: 10/24/2022]
Abstract
The aim of this study was to assess the in vitro activity of cefepime combined with sulbactam against carbapenem-resistant clinical isolates of Acinetobacter spp. The checkerboard method was used to determine whether combinations act synergistically against these strains. Twenty-three Acinetobacter baumannii and one Acinetobacter junii found to be carbapenem resistant were included in the study. The susceptibility results for cefepime and sulbactam were interpreted according to the guidelines of the Clinical and Laboratory Standards Institute. Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922 were used as quality control strains. The combination of cefepime and sulbactam demonstrated the following interactions: 33.3% (8/24) synergism; 58.3% (14/24) partial synergism; 4.2% (1/24) additive; 4.2% (1/24) indifference; and no antagonism (minimum and maximum fractional inhibitory concentration index 0.25 and 1.5, respectively). According to our in vitro study results, combinations of cefepime with sulbactam have moderate synergistic activity against some carbapenem-resistant strains of Acinetobacter spp., which could be beneficial for the treatment of infections due to multidrug-resistant strains of Acinetobacter spp.
Collapse
Affiliation(s)
- WeiHang Tong
- Department of Clinical Pharmacology, PLA General Hospital, 28 Fuxing Road, Beijing 100853, PR China
| | | | | | | | | |
Collapse
|
41
|
Rahal JJ. Novel Antibiotic Combinations against Infections with Almost Completely Resistant Pseudomonas aeruginosa and Acinetobacter Species. Clin Infect Dis 2006; 43 Suppl 2:S95-9. [PMID: 16894522 DOI: 10.1086/504486] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
For infections with antibiotic-susceptible strains of Pseudomonas aeruginosa, most studies have suggested that combination therapy, usually with a beta -lactam antibiotic plus an aminoglycoside, is preferable for patients with bacteremia and neutropenia. Against infections with Pseudomonas aeruginosa or Acinetobacter baumannii isolates that are resistant to all antibiotics except the polymyxins, several novel antibiotic combinations demonstrate increased activity in vitro compared with that of any single agent. Whether these combinations yield outcomes that are improved over those seen with a polymyxin or other agent alone remains to be determined. However, against infections with species resistant to all antibiotics, including polymyxins, novel combinations are the only remaining therapeutic option.
Collapse
Affiliation(s)
- James J Rahal
- Infectious Disease Section and Lang Research Center, New York Hospital Queens, and Department of Medicine, Weill College of Medicine, Cornell University, New York, New York 11355-5095, USA.
| |
Collapse
|
42
|
Motaouakkil S, Charra B, Hachimi A, Nejmi H, Benslama A, Elmdaghri N, Belabbes H, Benbachir M. Colistin and rifampicin in the treatment of nosocomial infections from multiresistant Acinetobacter baumannii. J Infect 2006; 53:274-8. [PMID: 16442632 DOI: 10.1016/j.jinf.2005.11.019] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 11/09/2005] [Accepted: 11/18/2005] [Indexed: 01/02/2023]
Abstract
INTRODUCTION The increased incidence of nosocomial infections by multi-drug resistant Acinetobacter baumannii creates demand on the application of some combinations of older antimicrobials on that species. We conducted the present observational study to evaluate the efficacy of intravenous and aerosolized colistin combined with rifampicin in the treatment of critically patients with nosocomial infections caused by multiresistant A. baumannii. PATIENTS AND METHODS Critically ill patients with nosocomial infections caused by A. baumannii resistant to all antibiotics except colistin in a medical intensive care unit. Diagnosis of infection was based on clinical data and isolation of bacteria. The bacterial susceptibilities to colistin were tested. Clinical response to colistin+rifampicin was evaluated. RESULTS Twenty-six patients (43.58+/-18.29 years, Acute Physiology and Chronic Health Evaluation II Score (APACHE II): 6.35+/-2.99), of whom 16 cases of nosocomial pneumonia treated by aerosolized colistin (1x10(6) IU three times/day) associated with intravenous rifampicin (10 mg/kg every 12h), nine cases of bacteraemia treated by intravenous colistin (2x10(6)IU three times/day) associated with intravenous rifampicin (10 mg/kg every 12h) in which three cases associated with ventilator associated pneumonia and one case of nosocomial meningitis treated by intrathecal use of colistin associated with intravenous rifampicin. The clinical evolution was favourable for all ill patients. Concerning side effects, we have noticed a moderate hepatic cytolysis in three patients. CONCLUSION This is the first clinical report of colistin combined with rifampicin for treatment of A. baumannii infection. Despite the lack of a control group and the limited number of patients, the results seem to be encouraging.
Collapse
Affiliation(s)
- Said Motaouakkil
- Medical Intensive Care Unit, Ibn Rochd University Hosptial, Casablanca, Morocco.
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Aparicio I, Bello MA, Callejón M, Guiraúm A. Simultaneous determination of rifampicin and sulbactam in mouse plasma by high-performance liquid chromatography. Biomed Chromatogr 2006; 20:748-52. [PMID: 16252264 DOI: 10.1002/bmc.591] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A simple and rapid high-performance liquid chromatographic (HPLC) method with ultraviolet detection has been developed and validated for the simultaneous determination of rifampicin and sulbactam in mouse plasma. Plasma samples were deproteinized with acetonitrile and separated by HPLC on a RP-18 (125 x 4 mm, 5 microm) column and gradient elution with potassium dihydrogen phosphate solution (pH 4.5; 50 mm) and acetonitrile at a flow-rate of 1.0 mL/min. Rifampicin and sulbactam were monitored at 230 nm and confirmed by means of their UV spectra using a diode-array detector. The method was linear at plasma levels from 1 to 100 microg/mL for rifampicin and from 5 to 200 microg/mL for sulbactam. The limits of quantification were 0.6 microg/mL for rifampicin and 4.2 microg/mL for sulbactam. The intra- and inter-day precisions of the method (RSD) were lower than 5% for both compounds. Average recoveries of rifampicin and sulbactam from mice plasma were 98.2 and 89.3%, respectively. The developed method was successfully applied to the determination of the pharmacokinetic profile of both compounds in mice.
Collapse
Affiliation(s)
- Irene Aparicio
- Department of Analytical Chemistry, University of Seville, 41011 Seville, Spain.
| | | | | | | |
Collapse
|
44
|
Gleeson T, Petersen K, Mascola J. Successful treatment of Acinetobacter meningitis with meropenem and rifampicin. J Antimicrob Chemother 2005; 56:602-3. [PMID: 16046467 DOI: 10.1093/jac/dki274] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
45
|
Reina R, Estenssoro E, Sáenz G, Canales HS, Gonzalvo R, Vidal G, Martins G, Das Neves A, Santander O, Ramos C. Safety and efficacy of colistin in Acinetobacter and Pseudomonas infections: a prospective cohort study. Intensive Care Med 2005; 31:1058-65. [PMID: 15983759 DOI: 10.1007/s00134-005-2691-4] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2004] [Accepted: 05/27/2005] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To assess renal dysfunction and outcome in patients treated exclusively with colistin vs. other antibiotics. DESIGN AND SETTING Prospective cohort study in a mixed ICU in a university-affiliated hospital. PATIENTS 185 patients infected with Acinetobacter baumannii and Pseudomonas aeruginosa after an ICU stay longer than 48 h: 55 in the colistin group and 130 in the noncolistin group, similar in age, APACHE II, medical status, and SOFA score. MEASUREMENTS AND RESULTS We recorded data on epidemiology and severity of illness, site of infection, renal function before and after treatment, clinical cure, and mortality. Clinical cure was defined as simultaneous normalization of central temperature (< or = 38 degrees), leukocyte count (< or = 10,000/mm3), and PaO2/FIO2 ratio (>187). Before treatment creatinine was 0.9+/-0.2 in the colistin group and 0.9+/-0.1 in the noncolistin group; after treatment the value was 1.0+/-0.3 in both groups. The most frequent infection was ventilator-associated pneumonia: 53% vs. 66% in colistin and noncolistin groups, respectively, Acinetobacter was the cause in 65% and 60% and Pseudomonas in 35% and 53%. In the noncolistin group 81% of patients were treated with carbapenems. Inadequate empirical antimicrobial treatment was more frequent in the colistin group (100% vs. 8%), but there were no differences in the frequency of clinical cure on day 6 of treatment (15% and 17%) or in mortality (29% and 24%). CONCLUSIONS Colistin appears to be as safe and as effective as other antimicrobials for treatment of sepsis caused by Acinetobacter and Pseudomonas in critically ill patients.
Collapse
Affiliation(s)
- Rosa Reina
- Intensive Care Unit, Hospital Interzonal de Agudos General San Martín, 1 y 70, 1900 La Plata, Argentina.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Arroyo LA, García-Curiel A, Pachón-Ibañez ME, Llanos AC, Ruiz M, Pachón J, Aznar J. Reliability of the E-test method for detection of colistin resistance in clinical isolates of Acinetobacter baumannii. J Clin Microbiol 2005; 43:903-5. [PMID: 15695701 PMCID: PMC548043 DOI: 10.1128/jcm.43.2.903-905.2005] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We compared the E-test to the broth microdilution method for testing the susceptibility of 115 clinical isolates of Acinetobacter baumannii to colistin. Twenty-two (19.1%) strains were resistant to colistin and 93 (80.8%) strains were susceptible according to the reference broth microdilution method. A categorical agreement of 98.2% was found, with only two (1.7%) very major errors. Agreement within 1 twofold dilution between the E-test and the broth microdilution was 16.5%. Complete agreement was found for the strains for which MICs fell within the range of 0.25 to 1 microg of colistin/ml. However, there was poor concordance, particularly in extreme dilutions with higher MICs by the E-test method.
Collapse
Affiliation(s)
- L A Arroyo
- Clinical Microbiology, University Hospitals Vírgen del Rocío, Seville, Spain.
| | | | | | | | | | | | | |
Collapse
|
47
|
Sader HS, Jones RN. Comprehensive in vitro evaluation of cefepime combined with aztreonam or ampicillin/sulbactam against multi-drug resistant Pseudomonas aeruginosa and Acinetobacter spp. Int J Antimicrob Agents 2005; 25:380-4. [PMID: 15848291 DOI: 10.1016/j.ijantimicag.2005.01.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Accepted: 01/12/2005] [Indexed: 11/16/2022]
Abstract
Pseudomonas aeruginosa and Acinetobacter spp. are becoming increasingly resistant to antimicrobial agents, and serious infections caused by these organisms often require combination therapy. Interactions of cefepime with either aztreonam (P. aeruginosa; n=46) or ampicillin/sulbactam (Acinetobacter spp.; n=34) were investigated by the chequerboard synergy method against isolates with various resistance phenotypes, including resistance to imipenem (36 P. aeruginosa and 19 Acinetobacter spp.). Synergy or partial synergy interactions occurred with 56.5% of P. aeruginosa and 88.2% of Acinetobacter spp. strains examined. Among the imipenem-resistant strains, synergy or partial synergy interactions were observed in 47.2% of P. aeruginosa and 84.2% of Acinetobacter spp. strains. In addition, the vast majority of impenem-resistant strains showed MIC values within achievable concentrations in plasma for at least one of the antimicrobials evaluated in the combination. The role of combination antimicrobial therapy in the treatment of severe infections caused by multidrug-resistant P. aeruginosa and Acinetobacter spp. should be further evaluated to maximize favourable clinical outcomes.
Collapse
Affiliation(s)
- Helio S Sader
- JMI Laboratories Inc., 345 Beaver Kreek Centre, Suite A, North Liberty, IA 52317, USA.
| | | |
Collapse
|
48
|
Abstract
BACKGROUND The bacterial genus Acinetobacter, once viewed as inconsequential, has been increasingly implicated as a significant pathogen. Acinetobacter is becoming progressively more resistant to older and newer-generation antibiotics. The primary species encountered in infections is Acinetobacter baumannii. CASE REPORT A 39-year-old woman came in for treatment of a preseptal cellulitis and conjunctivitis. She was referred to W.W. Hastings Optometry Clinic eleven days after first being diagnosed with a hordeolum that developed into a preseptal cellulitis, despite the use of oral cephalexin anazithromycin. After being referred, the patient was placed on oral regimen of gatifloxacin and topical ciprofloxacin. The patient gradually improved over the next 10 days, with full resolution occurring 21 days after the first presentation. Culturing revealed the offending organism to be Acinetobacter. DISCUSSION Most ocular infections are still caused by common organisms such as Staphylococcus. However, atypical bacteria such as Acinetobacter are responsible for a minority of infections. Careful consideration of patient history and clinical signs must be made to differentiate preseptal cellulitis and orbital cellulitis. CONCLUSION This case emphasizes that clinicians need to be aware of emerging and resistant bacteria in ocular infections. Infections that do not respond to traditional therapy should be treated aggressively with the latest-generation antibiotics. Ocular infections that do not resolve in a timely manner should be cultured for the offending organism and these organisms should be tested for susceptibility to anti-microbial drugs.
Collapse
Affiliation(s)
- Jeff Miller
- Northeastern State University, College of Optometry, Tahlequah, Oklahoma 74464, USA.
| |
Collapse
|
49
|
Vatcheva-Dobrevsky R, Savov E, Bernards A, van den Barselaar M, Dijkshoorn L. Molecular Characterization and Determination of Antibiotic Resistance of Acinetobacter Baumanii Isolates from a Bulgarian Hospital. BIOTECHNOL BIOTEC EQ 2005. [DOI: 10.1080/13102818.2005.10817246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
50
|
Dueñas Díez AI, Bratos Pérez MA, Eiros Bouza JM, Almaraz Gómez A, Gutiérrez Rodríguez P, Miguel Gómez MA, Orduña Domingo A, Rodríguez-Torres A. Susceptibility of the Acinetobacter calcoaceticus–A. baumannii complex to imipenem, meropenem, sulbactam and colistin. Int J Antimicrob Agents 2004; 23:487-93. [PMID: 15120728 DOI: 10.1016/j.ijantimicag.2003.09.026] [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] [Received: 06/10/2003] [Accepted: 09/26/2003] [Indexed: 11/30/2022]
Abstract
The Acinetobacter calcoaceticus-Acinetobacter baumannii complex includes some of the most clinically relevant species of the genus Acinetobacter due to their capacity to cause epidemic nosocomial outbreaks as well as their increasing resistance to antibiotics. Susceptibility of Acinetobacter strains varies greatly depending on origin, thus highlighting the importance of local analyses of susceptibility profiles. Two hundred twenty-one strains of the A. calcoaceticus-A. baumannii complex were identified using biochemical tests and were biotyped. Strain susceptibility to imipenem, meropenem, colistin and sulbactam was studied using agar dilution. Eight different biotypes were found, type 1 accounting for 69.2% of the strains. MIC(50) and MIC(90) to imipenem, meropenem, colistin and sulbactam were 4 and 8 mg/l, 16 and 32 mg/l, 0.5 and 1mg/l, and 8 and 16 mg/l, with susceptibility rates of 64.3, 22.6, 98.2 and 73.8%, respectively. Biotype 1 was the most resistant. A statistically significant difference was observed for the mean MIC of the four predominant biotypes to imipenem, meropenem and sulbactam but not to colistin.
Collapse
Affiliation(s)
- Ana Isabel Dueñas Díez
- Departamento de Microbiología, Facultad de Medicina de Valladolid, Hospital Universitario de Valladolid, Avda. Ramón y Cajal 7, 47005 Valladolid, Spain
| | | | | | | | | | | | | | | |
Collapse
|