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Increasing the Efficacy of Treatment of Staphylococcus aureus- Candida albicans Mixed Infections with Myrtenol. Antibiotics (Basel) 2022; 11:antibiotics11121743. [PMID: 36551400 PMCID: PMC9774912 DOI: 10.3390/antibiotics11121743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 11/27/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Infectious diseases caused by various nosocomial microorganisms affect worldwide both immunocompromised and relatively healthy persons. Bacteria and fungi have different tools to evade antimicrobials, such as hydrolysis damaging the drug, efflux systems, and the formation of biofilm that significantly complicates the treatment of the infection. Here, we show that myrtenol potentiates the antimicrobial and biofilm-preventing activity of conventional drugs against S. aureus and C. albicans mono- and dual-species cultures. In our study, the two optical isomers, (-)-myrtenol and (+)-myrtenol, have been tested as either antibacterials, antifungals, or enhancers of conventional drugs. (+)-Myrtenol demonstrated a synergistic effect with amikacin, fluconazole, and benzalkonium chloride on 64-81% of the clinical isolates of S. aureus and C. albicans, including MRSA and fluconazole-resistant fungi, while (-)-myrtenol increased the properties of amikacin and fluconazole to repress biofilm formation in half of the S. aureus and C. albicans isolates. Furthermore, myrtenol was able to potentiate benzalkonium chloride up to sixteen-fold against planktonic cells in an S. aureus-C. albicans mixed culture and repressed the adhesion of S. aureus. The mechanism of both (-)-myrtenol and (+)-myrtenol synergy with conventional drugs was apparently driven by membrane damage since the treatment with both terpenes led to a significant drop in membrane potential similar to the action of benzalkonium chloride. Thus, due to the low toxicity of myrtenol, it seems to be a promising agent to increase the efficiency of the treatment of infections caused by bacteria and be fungi of the genus Candida as well as mixed fungal-bacterial infections, including resistant strains.
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Are Efficient-Dose Mixtures a Solution to Reduce Fungicide Load and Delay Evolution of Resistance? An Experimental Evolutionary Approach. Microorganisms 2021; 9:microorganisms9112324. [PMID: 34835451 PMCID: PMC8622124 DOI: 10.3390/microorganisms9112324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 10/31/2021] [Indexed: 11/17/2022] Open
Abstract
Pesticide resistance poses a critical threat to agriculture, human health and biodiversity. Mixtures of fungicides are recommended and widely used in resistance management strategies. However, the components of the efficiency of such mixtures remain unclear. We performed an experimental evolutionary study on the fungal pathogen Z. tritici to determine how mixtures managed resistance. We compared the effect of the continuous use of single active ingredients to that of mixtures, at the minimal dose providing full control of the disease, which we refer to as the "efficient" dose. We found that the performance of efficient-dose mixtures against an initially susceptible population depended strongly on the components of the mixture. Such mixtures were either as durable as the best mixture component used alone, or worse than all components used alone. Moreover, efficient dose mixture regimes probably select for generalist resistance profiles as a result of the combination of selection pressures exerted by the various components and their lower doses. Our results indicate that mixtures should not be considered a universal strategy. Experimental evaluations of specificities for the pathogens targeted, their interactions with fungicides and the interactions between fungicides are crucial for the design of sustainable resistance management strategies.
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Mandal MK, Ghosh S, Bhat HR, Naesens L, Singh UP. Synthesis and biological evaluation of substituted phenyl azetidine-2-one sulphonyl derivatives as potential antimicrobial and antiviral agents. Bioorg Chem 2020; 104:104320. [PMID: 33142428 DOI: 10.1016/j.bioorg.2020.104320] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/22/2020] [Accepted: 09/24/2020] [Indexed: 10/23/2022]
Abstract
In the present study, we intend to synthesize a series of novel substituted phenyl azetidine-2-one sulphonyl derivatives. The entire set of derivatives 5 (a-t) were screened for in-vitro antibacterial, and antifungal activity, and among them eleven compounds were further screened for the antiviral activity to predict their efficacy against pathogenic viruses. Interestingly, compound 5d, 5e, 5f, 5h, 5i, and 5j showed similar or better antibacterial activity as compared to ampicillin (standard). Moreover, compounds 5h, 5i, 5j, and 5q showed good inhibitory activity against fungal strains whereas other derivatives had mild or diminished activity in comparison with standard drug clotrimazole. The antimicrobial study indicated that compounds having electron-withdrawing groups showed the highest activity. Interestingly, these tested compounds showed weak antiviral activity against Vaccinia virus, Human Coronavirus (229E), Reovirus-1, Herpes simplex virus, Sindbis virus, Coxsackievirus B4, Yellow Fever virus, and Influenza B virus in HEL cell, Vero cell, and MDCK cell cultures. The findings of the present study might open new avenues to target human disease-causing deadly microbes and viruses.
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Affiliation(s)
- Milan Kumar Mandal
- Drug Design & Discovery Laboratory, Department of Pharmaceutical Sciences, Sam Higginbottom University of Agriculture, Technology & Sciences, Allahabad, Uttar Pradesh 211007, India
| | - Swagatika Ghosh
- Food Saftey and Drug Administration, Government of Uttar Pradesh, Lucknow, Uttar Pradesh 226018, India
| | - Hans Raj Bhat
- Department of Pharmaceutical Sciences, Dibrugarh University, Dibrugarh, Assam 786004, India
| | - Lieve Naesens
- Rega Institute of Medical Research, KU Leuven, B-3000 Leuven, Belgium
| | - Udaya Pratap Singh
- Drug Design & Discovery Laboratory, Department of Pharmaceutical Sciences, Sam Higginbottom University of Agriculture, Technology & Sciences, Allahabad, Uttar Pradesh 211007, India.
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Said HS, Abdelmegeed ES. Emergence of multidrug resistance and extensive drug resistance among enterococcal clinical isolates in Egypt. Infect Drug Resist 2019; 12:1113-1125. [PMID: 31118713 PMCID: PMC6510230 DOI: 10.2147/idr.s189341] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
INTRODUCTION Enterococci commonly inhabit the gastrointestinal tract of both human and animals; however, they have emerged as a leading cause of several infections with substantial morbidity and mortality. Their ability to acquire resistance combined with intrinsic resistance to various antimicrobials makes treatment of enterococcal infections challenging. MATERIALS AND METHODS The aim of the study was to evaluate the antimicrobial resistance pattern, and assess the prevalence of multidrug resistance (MDR) and extensive drug resistance (XDR) among enterococcal isolates, collected from different clinical sources, in Mansoura University Hospitals, Egypt. RESULTS Antibiotic sensitivity testing revealed elevated levels of resistance among enterococcal clinical isolates (N=103). All E. faecium (N=32) and 74.6% of E. faecalis isolates(N=71) were MDR, while two E. faecalis and four E. faecium isolates were XDR. High level gentamicin resistance was detected in 79.6%, most of them carried the aac(6')-Ie-aph(2'')-Ia gene. High level streptomycin resistance was seen in 36.9%, of which 52.6% carried the ant(6')-Ia gene. Resistance to macrolides and lincosamides were mediated by ermB (92.2%) and msrA/B (42.7%). tetK, tetL, andtetM genes were detected among tetracyclines resistant isolates. Resistance to vancomycin was detected in 15.5%, where vanB and vanC1 gene clusters were detected in VRE isolates. Ten isolates (9.7%) were resistant to linezolid, eight of which harbored the optrA gene. Vancomycin and linezolid resistant enterococci were more likely to exhibit strong/moderate biofilm formation than vancomycin and linezolid sensitive ones. CONCLUSION Elevated levels of resistance to different classes of antimicrobial agents and emergence of MDR and XDR strains pose a major threat with limited therapeutic options for infections caused by this emerging pathogen.
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Affiliation(s)
- Heba Shehta Said
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt,
| | - Eman Salama Abdelmegeed
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt,
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Sachs J, Döhl K, Weber A, Bonus M, Ehlers F, Fleischer E, Klinger A, Gohlke H, Pietruszka J, Schmitt L, Teusch N. Novel 3,4-Dihydroisocoumarins Inhibit Human P-gp and BCRP in Multidrug Resistant Tumors and Demonstrate Substrate Inhibition of Yeast Pdr5. Front Pharmacol 2019; 10:400. [PMID: 31040786 PMCID: PMC6476959 DOI: 10.3389/fphar.2019.00400] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 04/01/2019] [Indexed: 12/15/2022] Open
Abstract
Multidrug resistance (MDR) in tumors and pathogens remains a major problem in the efficacious treatment of patients by reduction of therapy options and subsequent treatment failure. Various mechanisms are described to be involved in the development of MDR with overexpression of ATP-binding cassette (ABC) transporters reflecting the most extensively studied. These membrane transporters translocate a wide variety of substrates utilizing energy from ATP hydrolysis leading to decreased intracellular drug accumulation and impaired drug efficacy. One treatment strategy might be inhibition of transporter-mediated efflux by small molecules. Isocoumarins and 3,4-dihydroisocoumarins are a large group of natural products derived from various sources with great structural and functional variety, but have so far not been in the focus as potential MDR reversing agents. Thus, three natural products and nine novel 3,4-dihydroisocoumarins were designed and analyzed regarding cytotoxicity induction and inhibition of human ABC transporters P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP) in a variety of human cancer cell lines as well as the yeast ABC transporter Pdr5 in Saccharomyces cerevisiae. Dual inhibitors of P-gp and BCRP and inhibitors of Pdr5 were identified, and distinct structure-activity relationships for transporter inhibition were revealed. The strongest inhibitor of P-gp and BCRP, which inhibited the transporters up to 80 to 90% compared to the respective positive controls, demonstrated the ability to reverse chemotherapy resistance in resistant cancer cell lines up to 5.6-fold. In the case of Pdr5, inhibitors were identified that prevented substrate transport and/or ATPase activity with IC50 values in the low micromolar range. However, cell toxicity was not observed. Molecular docking of the test compounds to P-gp revealed that differences in inhibition capacity were based on different binding affinities to the transporter. Thus, these small molecules provide novel lead structures for further optimization.
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Affiliation(s)
- Julia Sachs
- Bio-Pharmaceutical Chemistry and Molecular Pharmacology, Faculty of Applied Natural Sciences, Technische Hochschule Köln, Leverkusen, Germany
| | - Katja Döhl
- Institute of Biochemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Anja Weber
- Institute of Bioorganic Chemistry, Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, Jülich, Germany
| | - Michele Bonus
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Ferdinand Ehlers
- Bio-Pharmaceutical Chemistry and Molecular Pharmacology, Faculty of Applied Natural Sciences, Technische Hochschule Köln, Leverkusen, Germany
| | | | | | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.,John von Neumann Institute for Computing, Jülich Supercomputing Centre and Institute for Complex Systems - Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Jörg Pietruszka
- Institute of Bioorganic Chemistry, Heinrich-Heine-Universität Düsseldorf im Forschungszentrum Jülich, Jülich, Germany.,IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Nicole Teusch
- Bio-Pharmaceutical Chemistry and Molecular Pharmacology, Faculty of Applied Natural Sciences, Technische Hochschule Köln, Leverkusen, Germany
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Heidari H, Emaneini M, Dabiri H, Jabalameli F. Virulence factors, antimicrobial resistance pattern and molecular analysis of Enterococcal strains isolated from burn patients. Microb Pathog 2015; 90:93-7. [PMID: 26620079 DOI: 10.1016/j.micpath.2015.11.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/10/2015] [Accepted: 11/19/2015] [Indexed: 11/17/2022]
Abstract
The enterococci are emerging as a significant cause of hospital acquired infections. The pathogenesis of enterococci is attributed to the production of virulence factors and resistance to antibiotics. The purpose of the study was to assess the prevalence of genes encoding virulence factor, antimicrobial resistance determinant and molecular characteristic of enterococci isolated from burn patients. A total of 57 enterococci isolated from wound specimens of patients with burn injury were characterized by phenotypic and genotypic methods. The efaA was the most frequently detected gene (100%), followed by ace (89.1%), asa1 (54.3%), gelE (50%), cylA (30.4%), esp (23.9%) and hyl (8.7%) among Enterococcus faecalis isolates. The Enterococcus faecium strains carried asa1 and ace genes. All isolates were susceptible to tigecycline and vancomycin. Inducible resistance to clindamycin was not observed and 64% of isolates had resistance to erythromycin. High-level gentamicin resistance (HLGR) was seen in 65.2% of E. faecalis strains. The aac(6')-Ie-aph(2″)-Ia gene was found in 47.8% of E. faecalis isolates. Our data indicated that the efaA, ace and asa1 were most frequent genes encoding virulence factors among Enterococci isolated from burn wound infection and the incidence of virulence factor genes was higher in E. faecalis rather than other isolates. The molecular analysis demonstrated high genetic diversity among Enterococcus populations from burn patients.
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Affiliation(s)
- Hamid Heidari
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences Tehran, Iran
| | - Mohammad Emaneini
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences Tehran, Iran
| | - Hossein Dabiri
- Department of Medical Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences Tehran, Iran
| | - Fereshteh Jabalameli
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences Tehran, Iran.
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Tuli HS, Chaudhary P, Beniwal V, Sharma AK. Microbial pigments as natural color sources: current trends and future perspectives. Journal of Food Science and Technology 2014; 52:4669-78. [PMID: 26243889 DOI: 10.1007/s13197-014-1601-6] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 07/31/2014] [Accepted: 10/02/2014] [Indexed: 02/07/2023]
Abstract
Synthetic colors have been widely used in various industries including food, textile, cosmetic and pharmaceuticals. However toxicity problems caused by synthetic pigments have triggered intense research in natural colors and dyes. Among the natural Sources, pigment producing microorganisms hold a promising potential to meet present day challenges. Furthermore natural colors not only improve the marketability of the product but also add extra features like anti oxidant, anti cancer properties etc. In this review, we present various sources of microbial pigments and to explore their biological and clinical properties like antimicrobial, antioxidant, anticancer and anti inflammatory. The study also emphasizes upon key parameters to improve the bioactivity and production of microbial pigments for their commercial use in pharmacological and medical fields.
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Affiliation(s)
- Hardeep S Tuli
- Department of Biotechnology, M.M.E.C. Maharishi Markandeshwar University, Mullana, Ambala, 133207 Haryana India
| | - Prachi Chaudhary
- Department of Biotechnology, M.M.E.C. Maharishi Markandeshwar University, Mullana, Ambala, 133207 Haryana India
| | - Vikas Beniwal
- Department of Biotechnology, M.M.E.C. Maharishi Markandeshwar University, Mullana, Ambala, 133207 Haryana India
| | - Anil K Sharma
- Department of Biotechnology, M.M.E.C. Maharishi Markandeshwar University, Mullana, Ambala, 133207 Haryana India
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Thiyagarajan D, Goswami S, Kar C, Das G, Ramesh A. A prospective antibacterial for drug-resistant pathogens: a dual warhead amphiphile designed to track interactions and kill pathogenic bacteria by membrane damage and cellular DNA cleavage. Chem Commun (Camb) 2014; 50:7434-6. [DOI: 10.1039/c4cc02354d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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Phillips PL, Yang Q, Davis S, Sampson EM, Azeke JI, Hamad A, Schultz GS. Antimicrobial dressing efficacy against mature Pseudomonas aeruginosa biofilm on porcine skin explants. Int Wound J 2013; 12:469-83. [PMID: 24028432 PMCID: PMC7950379 DOI: 10.1111/iwj.12142] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 07/24/2013] [Indexed: 12/11/2022] Open
Abstract
An ex vivo porcine skin explant biofilm model that preserves key properties of biofilm attached to skin at different levels of maturity (0–3 days) was used to assess the efficacy of commercially available antimicrobial dressings and topical treatments. Assays were also performed on the subpopulation of antibiotic tolerant biofilm generated by 24 hours of pre‐treatment with gentamicin (120× minimal inhibitory concentration) prior to agent exposure. Five types of antimicrobial agents (iodine, silver, polyhexamethylene biguanide, honey and ethanol) and four types of moisture dressings (cotton gauze, sodium carboxymethylcellulose fibre, calcium alginate fibre and cadexomer beads) were assessed. Time‐release silver gel and cadexomer iodine dressings were the most effective in reducing mature biofilm [between 5 and 7 logarithmic (log) of 7‐log total], whereas all other dressing formulations reduced biofilm between 0·3 and 2 log in 24 or 72 hours with a single exposure. Similar results were found after 24‐hour exposure to silver release dressings using an in vivo pig burn wound model, demonstrating correlation between the ex vivo and in vivo models. Results of this study indicate that commonly used microbicidal wound dressings vary widely in their ability to kill mature biofilm and the efficacy is influenced by time of exposure, number of applications, moisture level and agent formulation (sustained release).
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Affiliation(s)
- Priscilla L Phillips
- Institute of Wound Research, Department of Obstetrics and Gynecology, College of Medicine, University of Florida, Gainesville, FL, USA.,Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Qingping Yang
- Institute of Wound Research, Department of Obstetrics and Gynecology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Stephen Davis
- Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Edith M Sampson
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - John I Azeke
- Institute of Wound Research, Department of Obstetrics and Gynecology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Afifa Hamad
- Institute of Wound Research, Department of Obstetrics and Gynecology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Gregory S Schultz
- Institute of Wound Research, Department of Obstetrics and Gynecology, College of Medicine, University of Florida, Gainesville, FL, USA
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Adhikari MD, Goswami S, Panda BR, Chattopadhyay A, Ramesh A. Membrane-directed high bactericidal activity of (gold nanoparticle)-polythiophene composite for niche applications against pathogenic bacteria. Adv Healthc Mater 2013. [PMID: 23184755 DOI: 10.1002/adhm.201200278] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The use of nanoscale materials as bactericidal agents represents a novel paradigm in the development of therapeutics against drug-resistant pathogenic bacteria. In this paper the antimicrobial activity of a water soluble (gold nanoparticle)-polythiophene (AuNP-PTh) composite against common bacterial pathogens is reported. The nanocomposite is broad-spectrum in its bactericidal activity and exhibits a membrane-directed mode of action on target pathogens. The therapeutic potency of AuNP-PTh is demonstrated by experiments which reveal that the nanocomposite can breach the outer membrane defense barrier of Gram-negative pathogens for subsequent killing by a hydrophobic antibiotic, inhibit the growth of model gastrointestinal pathogens in simulated gastric fluid, and significantly eradicate bacterial biofilms. The high bacterial selectivity and lack of cytotoxicity on human cells augers well for future therapeutic application of the nanocomposite against clinically relevant pathogenic bacteria.
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Affiliation(s)
- Manab Deb Adhikari
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam, India
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11
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Vudumula U, Adhikari MD, Ojha B, Goswami S, Das G, Ramesh A. Tuning the bactericidal repertoire and potency of quinoline-based amphiphiles for enhanced killing of pathogenic bacteria. RSC Adv 2012. [DOI: 10.1039/c2ra20140b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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12
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Allardyce RA, Langford VS, Hill AL, Murdoch DR. Detection of volatile metabolites produced by bacterial growth in blood culture media by selected ion flow tube mass spectrometry (SIFT-MS). J Microbiol Methods 2006; 65:361-5. [PMID: 16249043 DOI: 10.1016/j.mimet.2005.09.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 08/29/2005] [Accepted: 09/02/2005] [Indexed: 10/25/2022]
Abstract
To achieve faster bacteremia diagnosis, selected ion flow tube mass spectrometry (SIFT-MS) measured metabolic gases in the headspaces of BacT/ALERT blood culture bottles. Pseudomonas aeruginosa, Streptococcus pneumoniae, Escherichia coli, Staphylococcus aureus and Neisseria meningitidis growth and trace gas patterns were detected from 10 colony forming units after 6 h.
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Affiliation(s)
- Randall A Allardyce
- Department of Surgery, Christchurch School of Medicine and Health Sciences, Christchurch, New Zealand.
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13
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Huang B, Martin SJ, Bachmann KA, He X, Reese JH, Wei Y, Iwuagwu C. A nationwide survey of physician office visits found that inappropriate antibiotic prescriptions were issued for bacterial respiratory tract infections in ambulatory patients. J Clin Epidemiol 2005; 58:414-20. [PMID: 15862728 DOI: 10.1016/j.jclinepi.2004.09.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2003] [Revised: 09/11/2004] [Accepted: 09/19/2004] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Correlations between probabilities of resistance and the frequencies with which antibiotics were prescribed for treating bacterial respiratory infections were examined in a nationwide ambulatory population. STUDY DESIGN AND SETTING The data of a nationwide probability sample survey of visits to physician offices in the United States in 1999 were used to conduct this study of drug use. A clinical pharmacologist identified antibiotics prescribed during those visits using a large online database. The participating physicians diagnosed the bacterial respiratory infections. An infectious disease expert determined the probabilities of bacterial resistance from a nationwide antibiotic surveillance database. RESULTS Various bacterial respiratory infections were diagnosed during 6.5% of physician office visits in 1999. One or more antibiotics were prescribed during 51.0% of those visits. The probabilities of resistance to the most frequently prescribed antibiotics varied from 20% to 40% and showed a weak positive correlation with the frequencies of antibiotic prescriptions. CONCLUSION A significant number of inappropriate antibiotic prescriptions were issued for infections with a high probability of bacterial resistance to the prescribed antibiotics.
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Affiliation(s)
- Boji Huang
- Department of Health Evaluation Sciences, Penn State College of Medicine, 600 Centerview Drive, Hershey, PA 17022-0855, USA.
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Safdar N, Handelsman J, Maki DG. Does combination antimicrobial therapy reduce mortality in Gram-negative bacteraemia? A meta-analysis. THE LANCET. INFECTIOUS DISEASES 2004; 4:519-27. [PMID: 15288826 DOI: 10.1016/s1473-3099(04)01108-9] [Citation(s) in RCA: 258] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The use of combination antimicrobial therapy for bacteraemia caused by Gram-negative bacilli is controversial. We did a meta-analysis of published studies to determine whether a combination of two or more antimicrobials reduces mortality in patients with Gram-negative bacteraemia. Criteria for inclusion were: analytic studies of patients with documented Gram-negative bacteraemia that included patients receiving a single antibiotic (monotherapy) and patients receiving two or more antibiotics (combination therapy). Data on mortality (outcome) had to be provided. A pooled odds ratio was calculated with the random effects model of DerSimonian and Laird. Assessment of heterogeneity was done with the Breslow-Day test and reasons for heterogeneity were explored. 17 studies met the inclusion criteria, five prospective cohort studies, two prospective randomised trials, and ten retrospective cohort studies. Most studies used beta-lactams or aminoglycosides alone and in combination. The summary odds ratio was 0.96 (95% CI 0.70-1.32), indicating no mortality benefit with combination therapy. Subgroup analyses adjusting for year of publication, study design, and severity of illness did not change the results. Considerable heterogeneity was present in the main analyses. Analysis of only Pseudomonas aeruginosa bacteraemias showed a significant mortality benefit (OR 0.50, 95% CI 0.30-0.79). Our analysis does not support the routine use of combination antimicrobial therapy for Gram-negative bacteraemia, beyond settings where infection by P aeruginosa is strongly suspected or more than one drug would be desirable to assure in-vitro efficacy.
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Affiliation(s)
- Nasia Safdar
- Section of Infectious Diseases, Department of Medicine, University of Wisconsin Medical School, Madison, USA
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Abstract
Through billions of years of evolution, microbes have developed myriad defense mechanisms designed to ensure their survival. This protection is readily transferred to their fellow life forms via transposable elements. Despite very early warnings, humans have chosen to abuse the gift of antibiotics and have created a situation where all microorganisms are resistant to some antibiotics and some microorganisms are resistant to all antibiotics. When antibiotics are used, six events may occur with only one being beneficial: when the antibiotic aids the host defenses to gain control and eliminate the infection. Alternatively, the antibiotic may cause toxicity or allergy, initiate a superinfection with resistant bacteria, promote microbial chromosomal mutations to resistance, encourage resistance gene transfer to susceptible species, or promote the expression of dormant resistance genes.
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Affiliation(s)
- Thomas J Pallasch
- School of Dentistry, University of Southern California, Los Angeles, CA, USA.
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Trull TJ, Widiger TA, Lynam DR, Costa PT. Borderline personality disorder from the perspective of general personality functioning. JOURNAL OF ABNORMAL PSYCHOLOGY 2003; 112:193-202. [PMID: 12784828 DOI: 10.1037/0021-843x.112.2.193] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The authors extended previous work on the hypothesis that borderline personality disorder (BPD) can be understood as a maladaptive variant of personality traits included within the 5-factor model (FFM) of personality. In each of 3 samples, an empirically derived prototypic FFM borderline profile was correlated with individuals' FFM profiles to yield a similarity score, an FFM borderline index. Results across all samples indicated that the FFM borderline index correlated as highly with existing borderline measures as they correlated with one another, and the FFM borderline index correlated as highly with measures of dysfunction, history of childhood abuse, and parental psychopathology as did traditional measures of BPD. Findings support the hypothesis that BPD is a maladaptive variant of FFM personality traits.
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Affiliation(s)
- Timothy J Trull
- Department of Psychological Sciences, University of Missouri-Columbia, 65211, USA.
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Oncul O, Yüksel F, Altunay H, Açikel C, Celiköz B, Cavuşlu S. The evaluation of nosocomial infection during 1-year-period in the burn unit of a training hospital in Istanbul, Turkey. Burns 2002; 28:738-44. [PMID: 12464471 DOI: 10.1016/s0305-4179(02)00106-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An analysis of the burned patients, admitted to our eight bed burn unit and treated between 1 January and 31 December 2000, was performed. Prevalence, etiologic agents, length of hospitalization, cost of treatment and mortality rates caused by nosocomial infections (NIs) were studied. The study included 63 patients. Eighteen of these (Group-A) had 24 NI episodes. The most common NI observed was burn-wound infection (58.3%), followed by bacteraemia-sepsis (16.7%). NIs were not detected in the rest at all (Group B). The mean length of hospitalization was 38.5+/-19.7 days in Group A, and 20.3+/-7.6 days in Group B. The mean total burned surface area (TBSA) was 43+/-21 in Group A and 29+/-18 in Group B, while the most important independent risk factor for NI was TBSA in burned patients (OR, 1.08; CI(95), 0.93-1.24). NI prolonged the mean hospital stay to 18 days and increased the cost of treatment by 502 US dollars. The most common bacteria isolated was Pseudomonas aeruginosa (41.7%) and the second was methicillin resistant Staphylococcus aureus (MRSA-25.0%). All of the NI-free patients survived, while, five (28.5%) patients with NI died (P<0.01). These findings emphasized the need for careful disinfection and conscientious contact control procedures in areas that serve immunosupressed individuals, such as burned patients.
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Affiliation(s)
- Oral Oncul
- Department of Infectious Diseases and Clinical Microbiology, Gülhane Military Medical Academy, HaydarpaşaTraining Hospital, 81327 Usküdar, Istanbul, Turkey.
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Scheld WM, Koedel U, Nathan B, Pfister HW. Pathophysiology of bacterial meningitis: mechanism(s) of neuronal injury. J Infect Dis 2002; 186 Suppl 2:S225-33. [PMID: 12424702 DOI: 10.1086/344939] [Citation(s) in RCA: 221] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
No bacterial disease has undergone a more dramatic change in epidemiology during the past decade than acute bacterial meningitis. This review describes the changing epidemiology and considers some important recent observations that contribute to our understanding of the pathogenesis and pathophysiology of meningitis. The major focus is on the mechanisms of neuronal injury and the pathophysiologic concepts responsible for death and neurologic sequelae. In recent years, experimental studies have amplified our understanding of the substantial body of evidence that now implicates cytokines and chemokines, proteolytic enzymes, and oxidants in the inflammatory cascade leading to tissue destruction in bacterial meningitis. The molecular mechanisms responsible for oxidant-induced neuronal injury in meningitis are explored in some depth. Genetic targeting and/or pharmacologic blockade of the implicated pathways may be a future strategy for therapeutic adjunctive measures to improve outcome and may hold substantial promise, in concert with antimicrobial agents, in humans with acute bacterial meningitis.
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Affiliation(s)
- W Michael Scheld
- Division of Infectious Diseases, Department of Internal Medicine, University of Virginia School of Medicine, PO Box 801342, Charlottesville, VA 22908, USA.
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