1
|
Williem ES, Ibrahim ABM, Elkhalik SA, Marek J, Abbas SM. In vitro biological activity of cobalt(II) complexes with salicylaldimine ligands in microbial and cancer cells. Future Med Chem 2023; 15:1415-1426. [PMID: 37584209 DOI: 10.4155/fmc-2023-0190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023] Open
Abstract
Background: More studies using cobalt complexes as drugs are needed. Results: The drug action of two cobalt salicylaldimines was determined. The complexes and amphotericin B (20 mg/ml) inhibited Candida albicans at 9-15 and 21 mm. This concentration of both ligands inhibited Staphylococcus aureus at 10 mm and one ligand inhibited Escherichia coli at 9 mm, but the complexes and ampicillin inhibited four bacteria at 9-20 and 21-26 mm. The ligands were inactive against cancer and normal cells, but the complexes and doxorubicin provided IC50 values of 28.18-54.19 and 9.66 μM against MCF-7 cells and 15.76-20.49 and 36.42 μM against BHK cells. Conclusion: The ligands' activity was much improved by complexation, although they remained substandard.
Collapse
Affiliation(s)
- Ereny S Williem
- Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef, 62521, Egypt
| | - Ahmed B M Ibrahim
- Department of Chemistry, Faculty of Science, Assiut University, Assiut, 71516, Egypt
| | - S Abd Elkhalik
- Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef, 62521, Egypt
| | - Jaromír Marek
- Core Facility Biomolecular Interactions & Crystallography, CEITEC MU, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
- Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - S M Abbas
- Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef, 62521, Egypt
| |
Collapse
|
2
|
Zhang Y, Shi J, Liu L, Su X, Peng B, Sun W, Li J, Feng Y, Geng Y, Cheng G. Improving Solubility and Avoiding Hygroscopicity of Tetrahydropalmatine by Forming a Pharmaceutical Salt Cocrystal via CAHBs. CRYSTAL RESEARCH AND TECHNOLOGY 2022. [DOI: 10.1002/crat.202200151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Yunan Zhang
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Jingwen Shi
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Lixin Liu
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Xin Su
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Bihui Peng
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Weitong Sun
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Jinjing Li
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Yanru Feng
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | - Yiding Geng
- College of Pharmacy Jiamusi University Jiamusi 154007 China
| | | |
Collapse
|
3
|
Fathy A, Ibrahim ABM, Abd Elkhalik S, Meurer F, Bodensteiner M, Abbas SM. Thiosemicarbazones and Derived Antimony Complexes: Synthesis, Structural Analysis, and In Vitro Evaluation against Bacterial, Fungal, and Cancer Cells. INORGANICS 2022; 10:172. [DOI: 10.3390/inorganics10100172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Abstract
Two antimony complexes {[Sb(L1)Cl2] C1 and [Sb(L2)Cl2] C2} with the thiosemicarbazone ligands {HL1 = 4-(2,4-dimethylphenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide and HL2 = 4-(2,5-dimethoxyphenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide} were introduced. The structures were elucidated on the basis of a CHNS analysis, spectroscopic techniques (UV-Vis and FT-IR), and DMF solution electrical conductivities. Single crystal X-ray diffraction analysis of complex C1 assigned the complex pseudo-octahedral geometry and triclinic P-1 space group. Only the ligand HL1 and its derived complex C1 displayed antifungal activities against Candida albicans and this activity was enhanced from 10 mm to 21 mm for the respective complex, which is the same activity given by the drug “Amphotericin B”. The ligands HL1 and HL2 gave inhibitions, respectively, of 14 and 10 mm against Staphylococcus aureus and 15 and 10 mm against Escherichia coli; however, complexes C1 and C2 increased these inhibitions to 36 and 32 mm against Staphylococcus aureus and 35 and 31 mm against Escherichia coli exceeding the activities given by the ampicillin standard (i.e., 21 mm against Staphylococcus aureus and 25 mm against Escherichia coli). Against MCF-7 human breast cancer cells, the IC50 values of HL1 (68.9 μM) and HL2 (145.4 μM) were notably enhanced to the values of 34.7 and 37.4 μM for both complexes, respectively. Further, the complexes induced less toxicity in normal BHK cells (HL1 (126.6 μM), HL2 (110.6 μM), C1 (>210.1 μM), and C2 (160.6 μM)). As a comparison, doxorubicin gave an IC50 value of 9.66 μM against MCF-7 cells and 36.42 μM against BHK cells.
Collapse
|
4
|
Fathy A, Ibrahim ABM, Abd Elkhalik S, Villinger A, Abbas SM. Trivalent Cobalt Complexes with NNS Tridentate Thiosemicarbazones: Preparation, Structural Study and Investigation of Antibacterial Activity and Cytotoxicity against Human Breast Cancer Cells. INORGANICS 2022; 10:145. [DOI: 10.3390/inorganics10090145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
Abstract
New complexes of trivalent cobalt with substituted thiosemicarbazone ligands having an NNS donor system {HL1 = 4-(4-nitrophenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide and HL2 = 4-(2,5-dimethoxyphenyl)-1-((pyridin-2-yl)methylene)thiosemicarbazide} were synthesized via the in situ oxidation of divalent cobalt chloride accompanying its addition to the ligands. The complexes C1 and C2 were characterized via elemental (CHNS) analysis and 1H NMR, FT-IR and UV-Vis. spectroscopic data. Further, conductometric studies on the DMF solutions of the complexes indicated their 1:1 nature, and their diamagnetism revealed the low-spin trivalent oxidation state of the cobalt in the complexes. The X-ray diffraction analysis of complex C1 indicated that it crystallizes in the triclinic space group P-1. The metal exhibits an octahedral environment built by two anionic ligands bound via pyridine nitrogen, imine nitrogen and thiol sulfur atoms. The complex is counterbalanced by a chloride ion. In addition, two lattice water molecules were detected in the asymmetric unit of the unit cell. The ligand HL2 (20 mg/mL in DMSO) displayed inhibition zones of 10 mm against both S. aureus and E. coli, and the same concentration of the respective complex raised this activity to 15 and 12 mm against these bacterial strains, respectively. As a comparison, ampicillin inhibited these bacterial strains by 21 and 25 mm, respectively. Screening assay by HL1 on four human cancer cells revealed the most enhanced activity against the breast MCF-7 cells. The induced growth inhibitions in the MCF-7 cells by all compounds (0–100 μg/mL) have been detected. The ligands {HL1 and HL2} and complex C2 gave inhibitions with IC50 values of 52.4, 145.4 and 49.9 μM, respectively. These results are more meaningful in comparison with similar cobalt complexes, but less efficient compared with the inhibition with IC50 of 9.66 μM afforded by doxorubicin. In addition, doxorubicin, HL1 and HL2 induced cytotoxicity towards healthy BHK cells with IC50 values of 36.42, 54.8 and 110.6 μM, but surviving fractions of 66.1% and 62.7% of these cells were detected corresponding to a concentration of 100 μg/mL of the complexes (136.8 μM of C1 and 131.4 μM of C2).
Collapse
|
5
|
Teja C, Roshini H, Thiyagamurthy P, Daniel JA, Devi SA, Vidya R, Nawaz Khan FR. Tetrabutylammonium-salt, a novel ionic medium for the synthesis of quinoline–hybrid chalcones, and its biological evaluation. Polycycl Aromat Compd 2022. [DOI: 10.1080/10406638.2021.2020308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Chitrala Teja
- Organic and Medicinal Chemistry Research Laboratory, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Hanumanthu Roshini
- Organic and Medicinal Chemistry Research Laboratory, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Pandurangan Thiyagamurthy
- Organic and Medicinal Chemistry Research Laboratory, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - J. Arul Daniel
- Department of Biomedical Sciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - S. Asha Devi
- Department of Biomedical Sciences, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - R. Vidya
- VIT School of Agricultural Innovations and Advanced Learning, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Fazlur Rahman Nawaz Khan
- Organic and Medicinal Chemistry Research Laboratory, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| |
Collapse
|
6
|
Bio-Mechanism of Catechin as Pheromone Signal Inhibitor: Prediction of Antibacterial Agent Action Mode by In Vitro and In Silico Study. Molecules 2021; 26:molecules26216381. [PMID: 34770790 PMCID: PMC8587927 DOI: 10.3390/molecules26216381] [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: 09/17/2021] [Revised: 10/13/2021] [Accepted: 10/19/2021] [Indexed: 11/24/2022] Open
Abstract
The utilization of medicinal plants has long been explored for the discovery of antibacterial agents and the most effective mechanisms or new targets that can prevent and control the spread of antibiotic resistance. One kind of bacterial cell wall inhibition is the inactivation of the MurA enzyme that contributes to the formation of peptidoglycan. Another approach is to interfere with the cell–cell communication of bacteria called the Quorum sensing (QS) system. The blocking of auto-inducer such as gelatinase biosynthesis-activating pheromone (GBAP) can also suppress the virulence factors of gelatinase and serine protease. This research, in particular, aims to analyze lead compounds as antibacterial and anti-QS agents from Gambir (Uncaria gambir Roxburgh) through protein inhibition by in silico study. Antibacterial agents were isolated by bioactivity-guided isolation using a combination of chromatographic methods, and their chemical structures were determined by spectroscopic analysis methods. The in vitro antibacterial activity was evaluated by disc diffusion methods to determine inhibitory values. Meanwhile, in the in silico analysis, the compound of Uncaria gambir was used as ligand and compared with fosfomycin, ambuic acid, quercetin, and taxifolin as the standard ligand. These ligands were attached to MurA, GBAP, gelatinase, and serine proteases using Autodock Vina in PyRx 0.8 followed by PYMOL for combining the ligand conformation and proteins. plus programs to explore the complex, and visualized by Discovery Studio 2020 Client program. The antibacterial agent was identified as catechin that showed inhibitory activity against Enterococcus faecalis ATCC 29212 with inhibition zones of 11.70 mm at 10%, together with MIC and MBC values of 0.63 and 1.25 μg/mL, respectively. In the in silico study, the molecular interaction of catechin with MurA, GBAP, and gelatinase proteins showed good binding energy compared with two positive controls, namely fosfomycin and ambuic acid. It is better to use catechin–MurA (−8.5 Kcal/mol) and catechin–gelatinase (−7.8 Kcal/mol), as they have binding energies which are not marginally different from quercetin and taxifolin. On the other hand, the binding energy of serine protease is lower than quercetin, taxifolin, and ambuic acid. Based on the data, catechin has potency as an antibacterial through the inhibition of GBAP proteins, gelatinase, and serine protease that play a role in the QS system. This is the first discovery of the potential of catechin as an alternative antibacterial agent with an effective mechanism to prevent and control oral disease affected by antibiotic resistance.
Collapse
|
7
|
Vargas-Sinisterra AF, Ramírez-Castrillón M. Yeast carotenoids: production and activity as antimicrobial biomolecule. Arch Microbiol 2020; 203:873-888. [PMID: 33151382 DOI: 10.1007/s00203-020-02111-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/18/2020] [Accepted: 10/23/2020] [Indexed: 10/23/2022]
Abstract
Carotenoids are a large group of organic, pigmented, isoprenoid-type compounds that play biological activities in plants and microorganisms (yeasts, bacteria, and microalgae). Literature reported it as vitamin A precursors and antioxidant activity. Carotenoids also can act as antimicrobial agents and few reports showed quantitative measurements of Minimal Inhibitory Concentrations against different pathogens. In this sense, some carotenoids were added to medical-surgical materials. The demand for scale-up of different naturally obtained carotenoids has increased due to the concern about the detrimental health effects caused by synthetic molecules and antimicrobial resistance. In this review, we reported the variability in pigment production and culture conditions, extraction methods used in laboratory, and we discussed the antimicrobial activity carried out by these molecules and the promising acting as new molecules to be scaled-up to industry.
Collapse
Affiliation(s)
- Andrés Felipe Vargas-Sinisterra
- Maestría en Ciencias Biomédicas, Grupo de Investigación BIOSALUD, Facultad de Ciencias para la salud, Universidad de Caldas, Calle 65 # 26-10, Manizales, Colombia.,Grupo de Investigación iCUBO, Facultad de Ingeniería, Departamento de Ingeniería Bioquímica, Universidad Icesi, Calle 18 # 122-135, Cali, Colombia
| | - Mauricio Ramírez-Castrillón
- Research Group in Mycology (GIM/CICBA), Facultad de Ciencias Básicas, Universidad Santiago de Cali, Calle 5 # 62-00, Cali, Colombia.
| |
Collapse
|
8
|
Kumar MS, Das AP. Molecular identification of multi drug resistant bacteria from urinary tract infected urine samples. Microb Pathog 2016; 98:37-44. [PMID: 27354209 DOI: 10.1016/j.micpath.2016.06.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/16/2016] [Accepted: 06/24/2016] [Indexed: 10/21/2022]
Abstract
Urinary tract infections (UTIs) are of great concern in both developing and developed countries all over the world. Even though the infections are more common in women and children, they are at a considerable rate in men and of all ages. The uropathogens causing the infections are spread through various routes. The treatment generally recommended by the physicians is antibiotic usage. But, most of the uropathogens have evolved antibiotic resistance mechanisms. This makes the present situation hectic in control and prevention of UTIs. The present study aims to illustrate the multidrug resistance patterns among isolated bacterial strains from infected urine samples in Odisha state, India. Four bacterial strains were isolated and identified as Proteus sp. SK3, Pseudomonas sp. ADMK77, Proteus sp. BLKB2 and Enterobacter hormaechei strain CW-3 by 16S rRNA gene sequencing. Phylogenetc analysis indicated the strains belong to three various genera namely, Proteus, Pseudomonas and Enterobacter. The evolutionary timeline of the bacteria was studied by constructing phylogenetic trees by Neighborhood Joining method. The presence of ESBL gene and biofilm forming capability were studied for the four strains. Antibiotic susceptibility patterns of the isolates were studied toward the commonly recommended antibiotics. Both the Proteus strains were found commonly susceptible to aminoglycoside and sulphonamide groups. Pseudomonas strain was found to be susceptible to cephems, aminoglycosides and fluoroquinolones. Enterobacter sp was found to be resistant to almost all antibiotic groups and susceptible to only sulphonamides group. The antibiotic susceptibility patterns of the bacteria help in choosing the empirical antibiotic treatment for UTI.
Collapse
Affiliation(s)
- M S Kumar
- Bioengineering & Biomineral Processing Laboratory, Centre of Biotechnology, Siksha O Anusandhan University, Khandagiri Square, Bhubaneswar, Odisha, India
| | - A P Das
- Bioengineering & Biomineral Processing Laboratory, Centre of Biotechnology, Siksha O Anusandhan University, Khandagiri Square, Bhubaneswar, Odisha, India.
| |
Collapse
|
9
|
O'Mahony T, Rekhif N, Cavadini C, Fitzgerald GF. The application of a fermented food ingredient containing 'variacin', a novel antimicrobial produced by Kocuria varians, to control the growth of Bacillus cereus in chilled dairy products. J Appl Microbiol 2001; 90:106-14. [PMID: 11155129 DOI: 10.1046/j.1365-2672.2001.01222.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The feasibility of applying variacin, a lantibiotic produced by Kocuria varians in the form of a spray-dried fermented ingredient to control the growth of psychrotrophic Bacillus cereus strains in chilled dairy foods, was evaluated. METHODS AND RESULTS A range of chilled dairy food formulations modelling commercially-available products were fabricated, to which were added varying amounts of active ingredient. These were subsequently challenged with a B. cereus spore cocktail over a range of abuse temperatures. This work was validated by the inclusion of the fermented ingredient to commercial products. CONCLUSION Results demonstrate the functionality of the bacteriocin at refrigeration abuse temperatures, and indicate the robust nature of the proteinaceous antimicrobial agent with regard to processing. SIGNIFICANCE AND IMPACT OF THE STUDY This study indicates the applicability of fermented food ingredients containing naturally-occurring antimicrobials as additional hurdles in food preservation.
Collapse
Affiliation(s)
- T O'Mahony
- Department of Microbiology, University College Cork, Ireland
| | | | | | | |
Collapse
|
10
|
Massengale AR, Ollar RA, Giordano SJ, Felder MS, Aronoff SC. Use of the paraffin wax baiting system for identification of Pseudomonas aeruginosa clinical isolates. Diagn Microbiol Infect Dis 1999; 35:177-83. [PMID: 10626126 DOI: 10.1016/s0732-8893(99)00075-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pseudomonas aeruginosa is the primary pathogen among the Pseudomonads and is known for its minimal nutritional requirements, capacity to use paraffin as a sole carbon source, and biofilm formation. Because the ability of Pseudomonads to grow on paraffin is not commonly found among human pathogens and the primary Pseudomonas human pathogen is P. aeruginosa, we studied the adaptation of the paraffin baiting system for the growth and identification of clinical isolates of P. aeruginosa. We also studied the effectiveness of combining a fluorescence assay measuring fluorescein (pyoverdin) production and oxidase test with the paraffin baiting assay for P. aeruginosa speciation. Strains were tested for the capacity to use paraffin as a sole carbon source using the paraffin baiting system with Czapek's minimal salt medium. Of 111 P. aeruginosa clinical isolates tested for using paraffin as a sole carbon source, 45% exhibited growth on paraffin at 24 h and 76.6% exhibited growth on paraffin at 48 h. The ability of the reference strains and clinical isolates were then tested for their ability to associate with the paraffin slide in the presence of an additional carbon source. Of 111 P. aeruginosa clinical isolates tested, 85 strains (76.6%), and 102 (93%) were associated with the paraffin surface at 24 and 48 h. We successfully combined fluorescence and oxidase assays with the paraffin baiting system for identification of P. aeruginosa. The simple and inexpensive paraffin baiting system is a useful method for the identification and study of P. aeruginosa suitable for both the clinical and research laboratory.
Collapse
Affiliation(s)
- A R Massengale
- Department of Pediatrics, West Virginia University School of Medicine, Morgantown 26506, USA
| | | | | | | | | |
Collapse
|
11
|
Opalchenova G, Obreshkova D. Antibacterial action of extracts of Clinopodium vulgare L. curative plant. Drug Dev Ind Pharm 1999; 25:323-8. [PMID: 10071825 DOI: 10.1081/ddc-100102177] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Clinopodium vulgare L. is one of the curative plants used in Bulgarian folk medicine, mainly during wars for the purposes of healing wounds. The antibacterial activity was studied based on its phytochemical properties. By colony forming unit (CFU)/ml values obtained in different intervals after inoculation of 5% extracts of Clinopodium vulgare L. in ethanol and propylene glycol, it has been proved that the plant showed a very strong action on bacteria. The effects of this action are on gram-positive and gram-negative microorganisms and also on isolated microorganisms at laboratory conditions from significant urocultures with multiple resistance. These results are very important as a basis for searching possibilities for utilizing the antibacterial properties of this plant pharmaceutically.
Collapse
|
12
|
Doern GV, Brueggemann AB, Perla R, Daly J, Halkias D, Jones RN, Saubolle MA. Multicenter laboratory evaluation of the bioMérieux Vitek antimicrobial susceptibility testing system with 11 antimicrobial agents versus members of the family Enterobacteriaceae and Pseudomonas aeruginosa. J Clin Microbiol 1997; 35:2115-9. [PMID: 9230393 PMCID: PMC229914 DOI: 10.1128/jcm.35.8.2115-2119.1997] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A four-center study in which a total of 1,082 recent clinical isolates of members of the family Enterobacteriaceae and Pseudomonas aeruginosa were examined versus 11 antimicrobial agents with the bioMérieux Vitek susceptibility test system (Hazelwood, Mo.) and the GNS-F6 card was conducted. In addition, a challenge set consisting of the same 200 organisms was examined in each of the four participating laboratories. Results obtained with the Vitek system were compared to MICs determined by a standardized broth microdilution method. For purposes of comparison, susceptibility categories (susceptible, intermediate, or resistant) were assigned on the basis of the results of both methods. The result of the broth microdilution test was considered definitive. The total category error rate with the Vitek system and the recent clinical isolates (11,902 organism-antimicrobial comparisons) was 4.5%, i.e., 1.7% very major errors, 0.9% major errors, and 1.9% minor errors. The total category error rate calculated from tests performed with the challenge set (i.e., 8,800 organism-antimicrobial comparisons) was 5.9%, i.e., 2.2% very major errors, 1.1% major errors, and 2.6% minor errors. Very major error rates higher than the totals were noted with Enterobacter cloacae versus ampicillin-sulbactam, aztreonam, ticarcillin, and ticarcillin-clavulanate and with P. aeruginosa versus mezlocillin, ticarcillin, and ticarcillin-clavulanate. Major error rates higher than the averages were observed with Proteus mirabilis versus imipenem and with Klebsiella pneumoniae versus ofloxacin. Excellent overall interlaboratory reproducibility was observed with the Vitek system. The importance of inoculum size as a primary determinant in the accuracy of susceptibility test results with the Vitek system was clearly demonstrated in this study. Specifically, when an inoculum density fourfold higher than that recommended by the manufacturer was used, high rates of false resistance results were obtained with cell wall-active antimicrobial agents versus both the Enterobacteriaceae and P. aeruginosa.
Collapse
Affiliation(s)
- G V Doern
- University of Massachusetts Medical Center, Worcester 01655, USA
| | | | | | | | | | | | | |
Collapse
|
13
|
Rittenhouse SF, Miller LA, Utrup LJ, Poupard JA. Evaluation of 500 gram negative isolates to determine the number of major susceptibility interpretation discrepancies between the Vitek and MicroScan Walkaway for 9 antimicrobial agents. Diagn Microbiol Infect Dis 1996; 26:1-6. [PMID: 8950521 DOI: 10.1016/s0732-8893(96)00144-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Although the Vitek and MicroScan Walkaway are two of the most commonly used automated antimicrobial susceptibility test systems, few studies have been performed comparing discrepancies between these systems. In this study, 500 Gram negative clinical isolates were tested against ampicillin, ampicillin/sulbactam, ticarcillin, ticarcillin/clavulanate, imipenem, ciprofloxacin, norfloxacin, mezlocillin, and piperacillin to determine the number of major interpretation discrepancies between the two systems. The 500 isolates consisted of 100 isolates each of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Enterobacter species. Each isolate was tested simultaneously in both systems using the same standardized inoculum. Eighty-four major discrepancies occurred, of which 48 were reproducible. The reproducible discrepancy rate, for the 4,500 isolate/antimicrobic combinations tested, was 48 of 4500 (1.06%). The rate for individual antimicrobics varied from 17 of 500 (3.4%) for ampicillin to no discrepancies for ticarcillin or ciprofloxacin. Of the 48 reproducible discrepancies, 44 (92%) were Vitek resistant, MicroScan susceptible. Fifteen (31%) of the Vitek and 21 (44%) of the MicroScan results were confirmed by broth microdilution. Disk diffusion results were in agreement with 15 (31%) of the Vitek and 21 (44%) of the MicroScan results. Twelve (25%) of the broth microdilution and 12 (25%) of the disk diffusion results were intermediate. The broth microdilution and disk diffusion results for the 48 isolates with reproducible discrepancies were in agreement more often with MicroScan. However, there was less very major error comparing the Vitek results for these isolates to the broth microdilution and disk diffusion. Overall, the result of this evaluation indicate that the number of major interpretation discrepancies between the two systems is minimal for the isolate/antimicrobic combinations tested.
Collapse
Affiliation(s)
- S F Rittenhouse
- Department of Antimicrobial Profiling/Clinical Microbiology, SmithKline Beecham Pharmaceuticals, Collegeville, Pennsylvania 19426, USA
| | | | | | | |
Collapse
|