1
|
DeRose PC, Benkstein KD, Elsheikh EB, Gaigalas AK, Lehman SE, Ripple DC, Tian L, Vreeland WN, Welch EJ, York AW, Zhang YZ, Wang L. Number Concentration Measurements of Polystyrene Submicrometer Particles. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12183118. [PMID: 36144906 PMCID: PMC9501160 DOI: 10.3390/nano12183118] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/15/2022] [Accepted: 09/02/2022] [Indexed: 06/01/2023]
Abstract
The number of techniques to measure number concentrations and size distributions of submicrometer particles has recently increased. Submicrometer particle standards are needed to improve the accuracy and reproducibility of these techniques. The number concentrations of fluorescently labeled polystyrene submicrometer sphere suspensions with nominal 100 nm, 200 nm and 500 nm diameters were measured using seven different techniques. Diameter values were also measured where possible. The diameter values were found to agree within 20%, but the number concentration values differed by as much as a factor of two. Accuracy and reproducibility related with the different techniques are discussed with the goal of using number concentration standards for instrument calibration. Three of the techniques were used to determine SI-traceable number concentration values, and the three independent values were averaged to give consensus values. This consensus approach is proposed as a protocol for certifying SI-traceable number concentration standards.
Collapse
Affiliation(s)
- Paul C. DeRose
- Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Kurt D. Benkstein
- Biomolecular Measurement Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Elzafir B. Elsheikh
- Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Adolfas K. Gaigalas
- Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Sean E. Lehman
- Biomolecular Measurement Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Dean C. Ripple
- Biomolecular Measurement Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Linhua Tian
- Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Wyatt N. Vreeland
- Biomolecular Measurement Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| | - Eric J. Welch
- Protein and Cell Analysis, Thermo Fisher Scientific, Eugene, OR 97402, USA
| | - Adam W. York
- Protein and Cell Analysis, Thermo Fisher Scientific, Eugene, OR 97402, USA
| | - Yu-Zhong Zhang
- Protein and Cell Analysis, Thermo Fisher Scientific, Eugene, OR 97402, USA
| | - Lili Wang
- Biosystems and Biomaterials Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA
| |
Collapse
|
2
|
Batarilo I, Maravic-Vlahovicek G, Bedenic B, Kazazic S, Bingulac Popovic J, Slade Vitkovic M, Katic S, Jukic I. Oxacillinases and antimicrobial susceptibility of Ralstonia pickettii from pharmaceutical water systems in Croatia. Lett Appl Microbiol 2022; 75:103-113. [PMID: 35352370 DOI: 10.1111/lam.13711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/03/2022] [Accepted: 03/24/2022] [Indexed: 11/30/2022]
Abstract
This study evaluated antibiotic susceptibility and presence of blaOXA22 and blaOXA60 genes in 81 isolates of Ralstonia pickettii obtained from different purified and ultra-pure water systems in two different geographical areas of Croatia. E-test and disk diffusion test were performed to determine antibiotic susceptibility. Polymerase Chain Reaction was applied to detect genes encoding OXA-22 and OXA-60, oxacillinases previously identified in R. pickettii. The isolates were genotyped by pulsed-field gel electrophoresis. The results revealed variable susceptibility/resistance profiles. Our isolates exhibited high susceptibility rates to ceftriaxone, cefotaxime, piperacillin-tazobactam, ciprofloxacin, imipenem, cefepime and in lesser extent to ceftazidime. High rates of susceptibility were also observed for sulfamethoxazole-trimethoprim and piperacillin. High resistance rates were noticed for ticarcillin-clavulanate, aztreonam and meropenem, as well as for all aminoglycosides tested. Modified Hodge test was positive in 51,9% strains, indicating production of carbapenemases. blaOXA22 and blaOXA60 genes were detected in 37.0% and 80.3% strains, respectively. Pulsed-field gel electrophoresis identified three major clusters containing subclusters. R. pickettii should be taken seriously as a possible cause of nosocomial infections to ensure adequate therapy, to prevent the development of resistant strains and to try to reduce the possibility of R. pickettii surviving in clean and ultra clean water systems.
Collapse
Affiliation(s)
- I Batarilo
- Croatian Institute for Transfusion Medicine, Zagreb, Croatia
| | | | - B Bedenic
- School of Medicine, University of Zagreb, Croatia.,University Hospital Center Zagreb, Croatia
| | - S Kazazic
- Ruđer Bošković Institute, Zagreb, Croatia
| | | | | | - S Katic
- School of Medicine, University of Zagreb, Croatia
| | - I Jukic
- Croatian Institute for Transfusion Medicine, Zagreb, Croatia.,Josip Juraj Strossmayer University of Osijek, Croatia
| |
Collapse
|