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Anthony RM, Davidson S, MacLeay JM, Brejda J, Werness P, Jewell DE. Comparison of two software programs used to determine the relative supersaturation of urine ions. Front Vet Sci 2023; 10:1146945. [PMID: 37332737 PMCID: PMC10274322 DOI: 10.3389/fvets.2023.1146945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/11/2023] [Indexed: 06/20/2023] Open
Abstract
Introduction Relative supersaturation (RSS) values for urine crystals are a measure of the risk of urinary stone formation and have been shown to be lowered in foods shown to aid in the management of urolithiasis. In order to calculate RSS in pets, computer programs have been developed to calculate RSS and aid in the understanding of stone formation in veterinary medicine. However, some older programs have not been updated for use in animals, and the specific coefficients used are not publically available. One of the first RSS programs was developed in BASIC computer language and published in 1985 which was called EQUIL2. The EQUIL2 program was updated to a compiled version compatible with a PC platform. However, the formulas could not be read or altered. Methods This study evaluates a new program with known coefficients to the original EQUIL2 program. The RSS values of the two programs were compared through a t-test, calculating the r2 from correlation analysis, Lin's concordance correlation coefficient, and by a Bland-Altman analysis of outputs from the two programs using urine samples from healthy dogs and cats. Results and Discussion Our results show that for both magnesium ammonium phosphate (struvite) and calcium oxalate, the RSS values of the original program could be calculated from the new programs RSS values. Although the actual RSS values were different (as might be expected through the use of the updated coefficients and different thermodynamic stability constants in the calculations) the results were highly correlated, finding elevations and reductions in RSS proportionally in the same urine samples. The current work creates a foundation for using the modernized program to calculate RSS and provides a shared method for understanding the risk of struvite and calcium oxalate stone formation.
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Affiliation(s)
| | | | | | - John Brejda
- Alpha Statistical Consulting, Lincoln, NE, United States
| | - Peter Werness
- Consultant for Hill’s Pet Nutrition, Inc, Topeka, KS, United States
| | - Dennis E. Jewell
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS, United States
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Anthony RM, MacLeay JM, Gross KL. Alpha-Lipoic Acid as a Nutritive Supplement for Humans and Animals: An Overview of Its Use in Dog Food. Animals (Basel) 2021; 11:ani11051454. [PMID: 34069383 PMCID: PMC8158713 DOI: 10.3390/ani11051454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary A review of human and animal studies involving alpha-lipoic acid supplementation was conducted to determine the utility of alpha-lipoic acid in dog food. The present literature shows that alpha-lipoic acid has utility as a nutritive additive at concentrations of 2.7–4.94 mg/kg body weight/day and improves antioxidant capacity in dogs. Abstract Alpha-lipoic acid (a-LA) is used as a nutritive additive in dog food. Therefore, we performed a systematic review of studies published to date in PubMed, Google Scholar, Cochrane Library and MedlinePlus involving alpha-lipoic acid supplementation, which included human clinical trials as well as animal studies, to evaluate its utility as a supplement in foods for healthy, adult dogs. While an upper limit of alpha-lipoic acid intake in humans has not been conclusively determined, the levels for oral intake of a-LA have been better defined in animals, and distinct differences based on species have been described. The maximum tolerated oral dose of a-LA in dogs has been reported as 126 mg/kg body weight and the LD50 as 400 to 500 mg/kg body weight. The antioxidant, anti-inflammatory and neuro-protective benefits of alpha-lipoic acid in dogs were observed at concentrations much lower than the maximum tolerated dose or proposed LD50. At concentrations of 2.7–4.94 mg/kg body weight/day, alpha-lipoic acid is well tolerated and posed no health risks to dogs while providing improved antioxidant capacity. This review thereby supports the utility of alpha-lipoic acid as an effective nutritive additive in dog food.
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Anthony RM, MacLeay JM, Jewell DE, Brejda JJ, Gross KL. Alpha-Lipoic Acid Is an Effective Nutritive Antioxidant for Healthy Adult Dogs. Animals (Basel) 2021; 11:ani11020274. [PMID: 33499039 PMCID: PMC7912130 DOI: 10.3390/ani11020274] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/10/2021] [Accepted: 01/11/2021] [Indexed: 01/28/2023] Open
Abstract
Simple Summary A 6 month prospective, controlled clinical trial was conducted to determine the nutritive antioxidant activity of alpha-lipoic acid as a maintenance food for healthy adult (non-gestational, non-lactating) dogs. The results of the study showed that increasing concentrations of alpha-lipoic acid induced a significant increase in the concentrations of intracellular glutathione, an important biomarker of the antioxidant system. Abstract This study was designed to determine the effect of alpha-lipoic acid on the glutathione status in healthy adult dogs. Following a 15 month baseline period during which dogs were fed a food containing no alpha-lipoic acid, dogs were randomly allocated into four groups. Groups were then fed a nutritionally complete and balanced food with either 0, 75, 150 or 300 ppm of alpha-lipoic acid added for 6 months. Evaluations included physical examination, body weight, food intake, hematology, serum biochemistry profile and measurements of glutathione in plasma and erythrocyte lysates. Throughout, blood parameters remained within reference ranges, dogs were healthy and body weight did not change significantly. A significant increase of 0.05 ng/mL of total glutathione in red blood cell (RBC) lysate for each 1 mg/kg bodyweight/day increase in a-LA intake was observed. In addition, a significant increase was observed for GSH, GSSG and total glutathione in RBC lysate at Month 6. We conclude that alpha-lipoic acid, as part of a complete and balanced food, was associated with increasing glutathione activity in healthy adult dogs.
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Affiliation(s)
- Reshma M. Anthony
- Hill’s Pet Nutrition, Inc., 1035 NE 43rd Street, Topeka, KS 66617, USA; (J.M.M.); (K.L.G.)
- Correspondence: ; Tel.: +1-785-286-8063; Fax: +1-785-286-8664
| | - Jennifer M. MacLeay
- Hill’s Pet Nutrition, Inc., 1035 NE 43rd Street, Topeka, KS 66617, USA; (J.M.M.); (K.L.G.)
| | - Dennis E. Jewell
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS 66506, USA;
| | - John J. Brejda
- Alpha Statistical Consulting, 1220 South 25th, Lincoln, NE 68502, USA;
| | - Kathy L. Gross
- Hill’s Pet Nutrition, Inc., 1035 NE 43rd Street, Topeka, KS 66617, USA; (J.M.M.); (K.L.G.)
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Anthony RM, den Hertog AL, van Soolingen D. 'Happy the man, who, studying nature's laws, Thro' known effects can trace the secret cause.' Do we have enough pieces to solve the pyrazinamide puzzle? J Antimicrob Chemother 2019. [PMID: 29528413 DOI: 10.1093/jac/dky060] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A low pH was assumed to be required for the activity of pyrazinoic acid (the active form of pyrazinamide) against Mycobacterium tuberculosis, but recently activity has been demonstrated at neutral pH. Renewed interest in pyrazinamide has led to an increasing number of potential targets and the suspicion that pyrazinamide is a 'dirty drug'. However, it is our opinion that the recent demonstration that pyrazinoic acid is active against PanD provides an alternative explanation for the secret of pyrazinamide's unusual activity. In this article we propose that PanD is the primary target of pyrazinoic acid but expression of pyrazinoic acid susceptibility requires an intact stress response. As the mycobacterial stress response requires the interaction of a number of genes, disruption of any could result in an inability to enter the susceptible phenotype. We believe this model can explain most of the recent observations of the seemingly diverse spectrum of activity of pyrazinamide.
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Affiliation(s)
- R M Anthony
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - A L den Hertog
- Institute for Life Sciences and Chemistry, HU University of Applied Sciences Utrecht, Utrecht, The Netherlands
| | - D van Soolingen
- National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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Van't Hoog AH, Bergval I, Tukvadze N, Sengstake S, Aspindzelashvili R, Anthony RM, Cobelens F. The potential of a multiplex high-throughput molecular assay for early detection of first and second line tuberculosis drug resistance mutations to improve infection control and reduce costs: a decision analytical modeling study. BMC Infect Dis 2015; 15:473. [PMID: 26503434 PMCID: PMC4624169 DOI: 10.1186/s12879-015-1205-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 10/12/2015] [Indexed: 11/17/2022] Open
Abstract
Background Molecular resistance detection (MRD) of resistance to second-line anti-tuberculous drugs provides faster results than phenotypic tests, may shorten treatment and allow earlier separation among patients with and without second-line drug resistance. Methods In a decision-analytical model we simulated a cohort of patients diagnosed with TB in a setting where drug resistant TB is highly prevalent and requires initial hospitalization, to explore the potential benefits of a high-throughput MRD-assay for reducing potential nosocomial transmission of highly resistant strains, and total costs for diagnosis of drug resistance, treatment and hospitalization. In the base case scenario first-line drug resistance was diagnosed with WHO-endorsed molecular tests, and second-line drug resistance with culture and phenotypic methods. Three alternative scenarios were explored, each deploying high-throughput MRD allowing either detection of second-line mutations in cultured isolates, directly on sputum, or MRD with optimized markers. Results Compared to a base case scenario, deployment of high-throughput MRD reduced total costs by 17-21 %. The period during which nosocomial transmission may take place increased by 15 % compared to the base case if MRD had currently reported suboptimal sensitivity and required cultured isolates; increased by 7 % if direct sputum analysis were possible including in patients with smear-negative TB, and reduced by 24 % if the assay had improved markers, but was still performed on cultured isolates. Improved clinical sensitivity of the assay (additional markers) by more than 35 % would be needed to avoid compromising infection control. Conclusions Further development of rapid second-line resistance testing should prioritize investment in optimizing markers above investments in a platform for direct analysis of sputum. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-1205-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- A H Van't Hoog
- Department of Global Health, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. .,Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands.
| | - I Bergval
- KIT Biomedical Research, Royal Tropical Institute, Amsterdam, The Netherlands.
| | - N Tukvadze
- National Tuberculosis Reference Laboratory, National Center for Tuberculosis and Lung Diseases, Tbilisi, Georgia.
| | - S Sengstake
- KIT Biomedical Research, Royal Tropical Institute, Amsterdam, The Netherlands.
| | - R Aspindzelashvili
- National Tuberculosis Reference Laboratory, National Center for Tuberculosis and Lung Diseases, Tbilisi, Georgia.
| | - R M Anthony
- KIT Biomedical Research, Royal Tropical Institute, Amsterdam, The Netherlands.
| | - F Cobelens
- Department of Global Health, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands. .,Amsterdam Institute for Global Health and Development, Amsterdam, The Netherlands. .,KNCV Tuberculosis Foundation, The Hague, The Netherlands.
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den Hertog AL, Daher S, Straetemans M, Scholing M, Anthony RM. No added value of performing Ziehl-Neelsen on auramine-positive samples for tuberculosis diagnostics. Int J Tuberc Lung Dis 2013; 17:1094-9. [PMID: 23827035 DOI: 10.5588/ijtld.12.0773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
SETTING Regional Laboratory for Tuberculosis, Amsterdam, The Netherlands. BACKGROUND There is a push to switch from Ziehl-Neelsen (ZN) to auramine microscopy. Despite World Health Organization guidelines that one staining method is sufficient, in some countries national guidelines prescribe that auramine-positive samples should be confirmed by ZN. OBJECTIVE To investigate the added value of confirming auramine-positive samples using ZN. DESIGN Using diagnostic data from 10 276 respiratory samples collected from 5525 patients tested for tuberculosis (TB) at the Municipal Health Service of Amsterdam between May 2006 and October 2011, we determined the diagnostic accuracy of auramine alone and of confirmation of auramine-positive samples using ZN. RESULTS Of 141 M. tuberculosis complex-positive samples detected using auramine on which ZN was performed, 32 (22.7%) were ZN-negative. A similar percentage (6/25, 24.0%) of negatives was found for samples containing non-tuberculous mycobacteria (NTM) species, thus making it impossible to distinguish between TB and NTM on the basis of ZN results. CONCLUSIONS A positive auramine result followed by a negative ZN result could not be used to exclude TB or to indicate the presence of NTM species. Confirming auramine-positive samples using ZN in this setting thus provided no clinically informative information and was a waste of resources.
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Affiliation(s)
- A L den Hertog
- Royal Tropical Institute, KIT, KIT Biomedical Research, Amsterdam, The Netherlands.
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Abstract
The aim of gene therapy for cystic fibrosis (CF) lung disease is to efficiently and safely express the CF transmembrane conductance regulator (CFTR) in the appropriate pulmonary cell types. Although CF patients experience multi-organ disease, the chronic bacterial lung infections and associated inflammation are the primary cause of shortened life expectancy. Gene transfer-based therapeutic approaches are feasible, in part, because the airway epithelium is directly accessible by aerosol delivery or instillation. Improvements in standard delivery vectors and the development of novel vectors, as well as emerging technologies and new animal models, are propelling exciting new research forward. Here, we review recent developments that are advancing this field of investigation.
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Affiliation(s)
- Patrick L Sinn
- Program in Gene Therapy, Department of Pediatrics, Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA
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Anthony RM, Cobelens FGJ, Gebhard A, Klatser PR, Lumb R, Rüsch-Gerdes S, van Soolingen D. Liquid culture for Mycobacterium tuberculosis: proceed, but with caution. Int J Tuberc Lung Dis 2009; 13:1051-1053. [PMID: 19723391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Attempts to improve the diagnosis of tuberculosis (TB) in high-burden countries has resulted in significant funding and initiatives to change the method of diagnosis of TB from light microscopy supplemented with X-ray to a sophisticated diagnostic algorithm based on the latest technological innovations. Such activities are overdue and should be welcomed, but the lack of skills and support available to interpret and use the results represents a danger. The introduction of new diagnostic methods, particularly liquid culture, should be carefully structured according to the local situation, failing which frustration and the disruption of previously underdeveloped but adequately functioning laboratories may result.
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Affiliation(s)
- R M Anthony
- Royal Tropical Institute, KIT Biomedical Research, Amsterdam, The Netherlands.
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den Hertog AL, Klatser PR, Anthony RM. Buoyant density of Mycobacterium tuberculosis: implications for sputum processing. Int J Tuberc Lung Dis 2009; 13:466-471. [PMID: 19335952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
SETTING A tuberculosis (TB) research laboratory in the Netherlands. OBJECTIVE The concentration of Mycobacterium tuberculosis cells from sputum is almost universally performed by centrifugation after chemical liquefaction. These methods are thus dependent on the effective sedimentation of mycobacterial cells, and the buoyant density of these cells relative to sputum is therefore of critical importance. DESIGN We cultured M. tuberculosis in different systems and measured their buoyant density. We also calculated the centrifuge times and speeds needed to effectively pellet the mycobacteria. RESULTS In contrast to earlier reports, we were unable to identify cells with a buoyant density <1 g/cm(3). The measured buoyant density of the cells ranged from 1.13 to 1.02 g/cm(3), and we suspect that the less dense cells are more likely to reflect clinically derived mycobacterial cells. CONCLUSION Based on our results, this means that for effective sedimentation in a typical universal centrifuge, centrifugation for 22 min at 3200 x g would be required. A limitation of this study is that cultured M. tuberculosis was studied. The data from this study should be confirmed in clinical samples. However, based on our results, centrifugation at lower speed for less time is unlikely to result in effective recovery.
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Affiliation(s)
- A L den Hertog
- KIT Biomedical Research, Royal Tropical Institute, Amsterdam, The Netherlands.
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Maeder ML, Thibodeau-Beganny S, Osiak A, Wright DA, Anthony RM, Eichtinger M, Jiang T, Foley JE, Winfrey RJ, Townsend JA, Unger-Wallace E, Sander JD, Müller-Lerch F, Fu F, Pearlberg J, Göbel C, Dassie JP, Pruett-Miller SM, Porteus MH, Sgroi DC, Iafrate AJ, Dobbs D, McCray PB, Cathomen T, Voytas DF, Joung JK. Rapid "open-source" engineering of customized zinc-finger nucleases for highly efficient gene modification. Mol Cell 2008; 31:294-301. [PMID: 18657511 PMCID: PMC2535758 DOI: 10.1016/j.molcel.2008.06.016] [Citation(s) in RCA: 507] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Revised: 05/16/2008] [Accepted: 06/04/2008] [Indexed: 11/17/2022]
Abstract
Custom-made zinc-finger nucleases (ZFNs) can induce targeted genome modifications with high efficiency in cell types including Drosophila, C. elegans, plants, and humans. A bottleneck in the application of ZFN technology has been the generation of highly specific engineered zinc-finger arrays. Here we describe OPEN (Oligomerized Pool ENgineering), a rapid, publicly available strategy for constructing multifinger arrays, which we show is more effective than the previously published modular assembly method. We used OPEN to construct 37 highly active ZFN pairs which induced targeted alterations with high efficiencies (1%-50%) at 11 different target sites located within three endogenous human genes (VEGF-A, HoxB13, and CFTR), an endogenous plant gene (tobacco SuRA), and a chromosomally integrated EGFP reporter gene. In summary, OPEN provides an "open-source" method for rapidly engineering highly active zinc-finger arrays, thereby enabling broader practice, development, and application of ZFN technology for biological research and gene therapy.
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Affiliation(s)
- Morgan L Maeder
- Molecular Pathology Unit and Center for Cancer Research, Massachusetts General Hospital, Charlestown, MA 02129, USA
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Baird HA, Gao Y, Galetto R, Lalonde M, Anthony RM, Giacomoni V, Abreha M, Destefano JJ, Negroni M, Arts EJ. Influence of sequence identity and unique breakpoints on the frequency of intersubtype HIV-1 recombination. Retrovirology 2006; 3:91. [PMID: 17164002 PMCID: PMC1764423 DOI: 10.1186/1742-4690-3-91] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2006] [Accepted: 12/12/2006] [Indexed: 11/20/2022] Open
Abstract
Background HIV-1 recombination between different subtypes has a major impact on the global epidemic. The generation of these intersubtype recombinants follows a defined set of events starting with dual infection of a host cell, heterodiploid virus production, strand transfers during reverse transcription, and then selection. In this study, recombination frequencies were measured in the C1-C4 regions of the envelope gene in the presence (using a multiple cycle infection system) and absence (in vitro reverse transcription and single cycle infection systems) of selection for replication-competent virus. Ugandan subtypes A and D HIV-1 env sequences (115-A, 120-A, 89-D, 122-D, 126-D) were employed in all three assay systems. These subtypes co-circulate in East Africa and frequently recombine in this human population. Results Increased sequence identity between viruses or RNA templates resulted in increased recombination frequencies, with the exception of the 115-A virus or RNA template. Analyses of the recombination breakpoints and mechanistic studies revealed that the presence of a recombination hotspot in the C3/V4 env region, unique to 115-A as donor RNA, could account for the higher recombination frequencies with the 115-A virus/template. Single-cycle infections supported proportionally less recombination than the in vitro reverse transcription assay but both systems still had significantly higher recombination frequencies than observed in the multiple-cycle virus replication system. In the multiple cycle assay, increased replicative fitness of one HIV-1 over the other in a dual infection dramatically decreased recombination frequencies. Conclusion Sequence variation at specific sites between HIV-1 isolates can introduce unique recombination hotspots, which increase recombination frequencies and skew the general observation that decreased HIV-1 sequence identity reduces recombination rates. These findings also suggest that the majority of intra- or intersubtype A/D HIV-1 recombinants, generated with each round of infection, are not replication-competent and do not survive in the multiple-cycle system. Ability of one HIV-1 isolate to outgrow the other leads to reduced co-infections, heterozygous virus production, and recombination frequencies.
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Affiliation(s)
- Heather A Baird
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Yong Gao
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Román Galetto
- Unité des Regulation Enzymatique et Activités Cellulaires, Institut Pasteur, Paris, Cedex 15, 75724, France
| | - Matthew Lalonde
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
- Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Reshma M Anthony
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Véronique Giacomoni
- Unité des Regulation Enzymatique et Activités Cellulaires, Institut Pasteur, Paris, Cedex 15, 75724, France
| | - Measho Abreha
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Jeffrey J Destefano
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Matteo Negroni
- Unité des Regulation Enzymatique et Activités Cellulaires, Institut Pasteur, Paris, Cedex 15, 75724, France
| | - Eric J Arts
- Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Anthony RM, DeStefano JJ. In vitro synthesis of long DNA products in reactions with HIV-RT and nucleocapsid protein. J Mol Biol 2006; 365:310-24. [PMID: 17070544 PMCID: PMC2493291 DOI: 10.1016/j.jmb.2006.10.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 09/29/2006] [Accepted: 10/02/2006] [Indexed: 10/24/2022]
Abstract
In vitro reaction conditions using HIV reverse transcriptase (RT) and nucleocapsid protein (NC) that allowed efficient synthesis of single-stranded DNA products over a thousand nucleotides in length from genomic HIV RNA were characterized. Consistent with previous reports, the reactions required high concentrations of NC and RT. Long products were produced as a result of frequent strand transfer between RNA templates, averaging at least one transfer per 300 nucleotides synthesized. No change in RT processivity was observed in the reactions in the presence versus absence of NC. Synthesis of long products required formation of a high molecular mass aggregate between NC and nucleic acids. The aggregate formed rapidly and pelleted with low speed centrifugation. The aggregate was accessible to RT as pre-formed aggregates synthesized long products when RT was added. NC finger mutants lacking either finger one or two or with the finger positions switched were all effective in promoting long products. This suggests that the aggregation/condensation but not helix-destabilizing activity of NC was required. We propose that these high molecular mass aggregates promote synthesis of long reverse transcription products in vitro by concentrating nucleic acids, RT enzyme and NC to close proximity, thereby mimicking the role of the capsid environment within the host cell.
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13
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Anthony RM, Kolk AHJ, Kuijper S, Klatser PR. Light emitting diodes for auramine O fluorescence microscopic screening of Mycobacterium tuberculosis. Int J Tuberc Lung Dis 2006; 10:1060-2. [PMID: 16964802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
We describe the simple adaptation of a standard fluorescent microscope for illumination using a 'Royal Blue' Luxeon light emitting diode (LED) and demonstrate that this form of illumination is suitable for the detection of auramine O stained Mycobacterium spp. The low cost, low power consumption, safety and reliability of LEDs makes them attractive alternatives to mercury vapour lamps.
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Affiliation(s)
- R M Anthony
- Department of Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, The Netherlands.
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Brown TJ, Herrera-Leon L, Anthony RM, Drobniewski FA. The use of macroarrays for the identification of MDR Mycobacterium tuberculosis. J Microbiol Methods 2006; 65:294-300. [PMID: 16153726 DOI: 10.1016/j.mimet.2005.08.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Revised: 08/05/2005] [Accepted: 08/15/2005] [Indexed: 10/25/2022]
Abstract
The emergence of Mycobacterium tuberculosis (Mtb), resistant to both isoniazid (INH) and rifampicin (RIF) (MDR-TB), is an increasing threat to tuberculosis control programs. Susceptibility testing of Mtb complex isolates by phenotypic methods requires a minimum of 14 days from a primary specimen. This can be reduced significantly if molecular analysis is used. Low density oligonucleotide arrays (macroarrays) have been used successfully for the detection of RIF resistance in Mtb. We describe the use of macroarray technology to identify Mtb complex isolates resistant to INH and/or RIF. The macroarray MDR-Mtb screen has been designed to detect mutations in the RIF resistance determining region (RRDR) of Mtb rpoB and loci in katG and mabA-inhA associated with INH resistance. A panel of Mtb isolates containing 38 different RRDR genotypes, 4 different genotypes within codon 315 of katG and 2 genotypes at mabA-inhA was used to validate the macroarray. The wild type (WT) genotype was correctly identified at all three loci. Of the 37 mutant rpoB genotypes, 36 were correctly detected; the single mutant not detected contained a 9 base insertion. All mutations within katG and mabA-inhA were correctly identified. We conclude that this low cost, rapid system can usefully detect the mutations associated with the vast majority of MDR-Mtb.
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Affiliation(s)
- T J Brown
- Health Protection Agency Mycobacterium Reference Unit, Kings College Hospital (Dulwich), East Dulwich Grove, London SE22 8QF, UK.
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Anthony RM, Schuitema ARJ, Oskam L, Klatser PR. Direct detection of Staphylococcus aureus mRNA using a flow through microarray. J Microbiol Methods 2005; 60:47-54. [PMID: 15567224 DOI: 10.1016/j.mimet.2004.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Revised: 08/10/2004] [Accepted: 08/23/2004] [Indexed: 11/26/2022]
Abstract
The direct detection of mRNAs from bacterial cultures on a DNA array without amplification and labelling would greatly extend the range of applications suitable for microarray analysis. Here we describe the direct detection of 23S rRNA and seven mRNA species from total Staphylococcus aureus RNA prepared using commercially available RNA purification columns followed by fluorescent detection on a flow through microarray. RNA hybridisation was detected using paired secondary labelled probes directly 5' and 3' to immobilised 60 mers. In this way, we were able to detect the effect of 30-min exposure to antimicrobials on mRNA levels within 3 h after column purification of total RNA without the need for enzymatic manipulation. Specifically the expression of mecA was confirmed in a highly resistant strain and induction of katA and ile-tRNA synthetase genes after exposure to mupirocin could be detected.
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MESH Headings
- Humans
- Oligonucleotide Array Sequence Analysis/methods
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/isolation & purification
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/isolation & purification
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- Staphylococcus aureus/genetics
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Affiliation(s)
- R M Anthony
- KIT Biomedical Research, Meibergdreef 39, 1105 AZ Amsterdam, The Netherlands.
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16
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Anthony RM, Schuitema ARJ, Chan AB, Boender PJ, Klatser PR, Oskam L. Effect of secondary structure on single nucleotide polymorphism detection with a porous microarray matrix; implications for probe selection. Biotechniques 2003; 34:1082-6, 1088-9. [PMID: 12765035 DOI: 10.2144/03345dd05] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Oligonucleotide arrays capable of detecting single nucleotide polymorphisms (SNPs) from amplified nucleic acid have many applications. The expected SNP is usually placed approximately in the center of the probe to ensure the maximum shift in Tm between complementary and SNP sequences. Unfortunately, different short probes (< 30 bases) selected using widely accepted criteria do not perform consistently in this type of assay. Here we present a systematic study on the effect of secondary structure on the ability of oligonucleotide probes to detect an SNP, using real-time array monitoring of a porous microarray substrate that incorporates a novel intra-array mixing system. These results demonstrate that, although positioning of an SNP in the middle of the probe is highly destabilizing, the effect of stable secondary structure on the signal obtained is so dramatic that such probes may be very insensitive. Therefore, if the SNP flanking sequence contains significant secondary structure, then more sensitive probes with good specificity may be obtained by positioning the mutation towards one end of the probe.
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Affiliation(s)
- R M Anthony
- KIT Biomedical Research, Amsterdam, The Netherlands.
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17
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Tansel O, Kuloglu F, Mutlu B, Anthony RM, Uyar A, Vahaboglu H, French GL. A methicillin-resistant Staphylococcus aureus outbreak in a new University hospital due to a strain transferred with an infected patient from another city six months previously. New Microbiol 2003; 26:175-80. [PMID: 12737200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Kocaeli University Medical School was established in 1995. The first methicillin resistant Staphylococcus aureus isolate was detected two years later in a patient transferred from a different city. Six months after this, we detected a small MRSA outbreak in the intensive care unit involving four patients, two of whom had bacteremia, and a staff nasal carrier. All isolates, including the first, appeared to be a single outbreak strain, demonstrated by pulsed field gel electrophoresis profiles which different by at most two bands, identical randomly amplified polymorphic DNA profiles, and identical coagulase gene types by PCR. Antibiogram were identical except that one isolate was additionally resistant to cotrimoxazole. These results show that MRSA isolates can spread between hospitals with infected or colonized patients and can apparently persist in the hospital for six months without causing infection. Screening of asymptomatic patients on wards affected by MRSA or transferred from other hospitals may be helpful in controlling these infections.
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Affiliation(s)
- O Tansel
- Medical Faculty of Trakya University, Department of Clinical Microbiology and Infectious Diseases, Edirne, Turkey
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18
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Pinter L, Anthony RM, Glumac N, Hajsig D, Pogacnik M, Drobnic-Kosorok M. Apparent cross-infection with a single strain of Malassezia pachydermatis on a pig farm. Acta Vet Hung 2002; 50:151-6. [PMID: 12113169 DOI: 10.1556/avet.50.2002.2.3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Twenty-nine isolates of Malassezia pachydermatis were recovered from a single farm of 100 pigs in Croatia. In contrast, 290 farm pigs from other locations (northern parts of Croatia and Slovenia) yielded only two non-lipid dependent isolates of M. pachydermatis using the same swabbing procedure. Ten of the 29 isolates from a single farm had their identity confirmed by karyotyping, and were typed by restriction fragment length polymorphism (RFLP) analysis. All but one of these isolates sub-typed were indistinguishable, one isolate produced a slightly different RFLP profile. Control isolates recovered from dog skin gave RFLP profiles that were easily distinguished from those produced by the pig isolates. These results suggest that a single strain of M. pachydermatis had colonised this pig herd.
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Affiliation(s)
- Ljiljana Pinter
- Department of Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, University of Zagreb, Zagreb 10000, P.O. Box 190, Croatia.
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19
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Witney AA, Doolan DL, Anthony RM, Weiss WR, Hoffman SL, Carucci DJ. Determining liver stage parasite burden by real time quantitative PCR as a method for evaluating pre-erythrocytic malaria vaccine efficacy. Mol Biochem Parasitol 2001; 118:233-45. [PMID: 11738713 DOI: 10.1016/s0166-6851(01)00372-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The detection and quantitation of blood stage parasitaemia is typically used as a surrogate endpoint for estimating the efficacy of vaccines targeted against the hepatic stage, as well as the erythrocytic stage, of the parasite. However, this does not provide an adequate means of evaluating the efficacy of vaccines, which may be only partially effective at the liver-stage. This is a particular concern for effective evaluation of immune enhancement strategies for candidate pre-erythrocytic stage vaccines. Here, we have developed and validated a method for detecting and quantitating liver stage parasites, using the TaqMan fluorescent real-time quantitative PCR system (PE Applied Biosystems). This method uses TaqMan primers designed to the Plasmodium yoelii 18S rRNA gene and rodent GAPDH to amplify products from infected mouse liver cDNA. The technique is highly reproducible as demonstrated with plasmid controls and capable of efficiently quantitating liver-stage parasite burden following a range of sporozoite challenge doses in strains of mice, which differ in their susceptibility to sporozoite infection. We have further demonstrated the capacity of this technique to evaluate the efficacy of a range of pre-erythrocytic stage vaccines. Our data establish this quantitative real-time PCR assay to be a fast and reproducible way of accurately assessing liver stage parasite burden and vaccine efficacy in rodent malaria models.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- DNA, Ribosomal/analysis
- Erythrocytes/parasitology
- Female
- Genes, rRNA
- Immunization, Passive
- Liver/parasitology
- Malaria/parasitology
- Malaria/prevention & control
- Malaria Vaccines/administration & dosage
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Molecular Sequence Data
- Plasmodium yoelii/genetics
- Plasmodium yoelii/growth & development
- Plasmodium yoelii/immunology
- Plasmodium yoelii/pathogenicity
- RNA, Ribosomal, 18S/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Analysis, DNA
- Taq Polymerase/metabolism
- Vaccination
- Vaccines, DNA/administration & dosage
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Affiliation(s)
- A A Witney
- Malaria Program, Naval Medical Research Center, 503 Robert Grant Avenue, Room 3A4O, Silver Spring, MD 20910-7500, USA
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20
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Abstract
Near instantaneous detection of pathogens from clinical material, combined with simultaneous prediction of their antimicrobial resistance profiles, would revolutionize the impact of microbiology on the management of infection. Array-based assays allow a range of characteristics to be rapidly and simultaneously determined. At present these systems have found their primary role as research tools for the monitoring of mRNA expression in the form of DNA microarrays or 'chips'. As fabrication costs reduce and validated targeted arrays are developed, it is inevitable they will be used for more routine applications. Microfluidics offers the exciting possibility of combining purification, amplification and detection in a single disposable device; microarrays are particularly suitable for use within these systems. Arrays will become an important tool for clinical diagnostics.
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Affiliation(s)
- R M Anthony
- NH Swellengrebel Laboratorium, voor Tropical Hygiene, Mibergdreef 39, 1105 AZ, Amsterdam, The Netherlands
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21
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Kalasinsky KS, Bosy TZ, Schmunk GA, Reiber G, Anthony RM, Furukawa Y, Guttman M, Kish SJ. Regional distribution of methamphetamine in autopsied brain of chronic human methamphetamine users. Forensic Sci Int 2001; 116:163-9. [PMID: 11182268 DOI: 10.1016/s0379-0738(00)00368-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We measured levels of methamphetamine and those of its metabolite amphetamine in 15 autopsied brain regions of 14 human methamphetamine users. Only slight regional differences were observed in drug concentrations among the brain areas. Although, some redistribution of the drugs probably occurred postmortem, these data suggest that methamphetamine might not be preferentially retained in dopamine-rich brain areas but is heterogenously distributed in brain of chronic human users of the drug. The possible pharmacological actions of methamphetamine in both dopamine-rich and poor brain areas of chronic drug users need to be considered.
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Affiliation(s)
- K S Kalasinsky
- Office of the Armed Forces Medical Examiner, Division of Forensic Toxicology, Armed Forces institute of Pathology, Washington, DC, USA
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22
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Brown TJ, Anthony RM. The addition of low numbers of 3' thymine bases can be used to improve the hybridization signal of oligonucleotides for use within arrays on nylon supports. J Microbiol Methods 2000; 42:203-7. [PMID: 11018277 DOI: 10.1016/s0167-7012(00)00175-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Oligonucleotide arrays can be used for the analysis of microbial nucleic acid. The addition of high numbers of dTTP to the 3' ends of oligonucleotides using terminal transferase has been shown to facilitate membrane binding. This paper demonstrates low numbers of thymine bases added to the 3' end of oligonucleotides during synthesis can improve hybridisation signal intensity where the signal seen with the unmodified oligonucleotides is poor. Thus, the addition of variable numbers of thymine bases to different oligonucleotides allows the production of oligonucleotide arrays producing strong interpretable hybridisation signals.
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Affiliation(s)
- T J Brown
- Department of Microbiology, St. Thomas Hospital, Guy's and St. Thomas' Hospital Trust, London SE1 7EH, UK.
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23
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Anthony RM, Brown TJ, French GL. Rapid diagnosis of bacteremia by universal amplification of 23S ribosomal DNA followed by hybridization to an oligonucleotide array. J Clin Microbiol 2000; 38:781-8. [PMID: 10655385 PMCID: PMC86203 DOI: 10.1128/jcm.38.2.781-788.2000] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/1999] [Accepted: 10/29/1999] [Indexed: 11/20/2022] Open
Abstract
The rapid identification of bacteria in blood cultures and other clinical specimens is important for patient management and antimicrobial therapy. We describe a rapid (<4 h) detection and identification system that uses universal PCR primers to amplify a variable region of bacterial 23S ribosomal DNA, followed by reverse hybridization of the products to a panel of oligonucleotides. This procedure was successful in discriminating a range of bacteria in pure cultures. When this procedure was applied directly to 158 unselected positive blood culture broths on the day when growth was detected, 125 (79.7%) were correctly identified, including 4 with mixed cultures. Nine (7.2%) yielded bacteria for which no oligonucleotide targets were present in the oligonucleotide panel, and 16 culture-positive broths (10.3%) produced no PCR product. In seven of the remaining eight broths, streptococci were identified but not subsequently grown, and one isolate of Staphylococcus aureus was misidentified as a coagulase-negative staphylococcus. The accuracy, range, and discriminatory power of the assay can be continually extended by adding further oligonucleotides to the panel without significantly increasing complexity or cost.
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Affiliation(s)
- R M Anthony
- Department of Microbiology, King's College St. Thomas' Campus, St. Thomas' Hospital, London SE1 7EH, United Kingdom
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24
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Andrasevic AT, Power EG, Anthony RM, Kalenic S, French GL. Failure of bacteriophage typing to detect an inter-hospital outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in Zagreb subsequently identified by random amplification of polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE). Clin Microbiol Infect 1999; 5:634-42. [PMID: 11851695 DOI: 10.1111/j.1469-0691.1999.tb00421.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To establish the extent of inter-hospital spread of methicillin-resistant Staphylococcus aureus (MRSA) in Zagreb and to determine the most suitable method for typing local strains. METHODS We analyzed a collection of 33 MRSA isolates from three Zagreb hospitals together with five unrelated British MRSA isolates by antibiogram typing, bacteriophage typing, randomly amplified polymorphic DNA (RAPD) analysis and pulsed-field gel electrophoresis (PFGE) after digestion with Smal restriction endonuclease. Bacteriophage typing was done with the international set of S. aureus typing phages. RAPD and PFGE profiles were analyzed visually and by using the 'GelCompar' computer program. RESULTS Antibiogram typing provided eight profiles. Thirty (91%) of the 33 Croatian strains of MRSA were non-typable by phage typing. Visual analysis of RAPD products identified six, and visual analysis of PFGE fragments nine, distinct profiles. Computer analysis of RAPD data separated British isolates from the Croatian ones, but did not cluster the visually determined RAPD types. PFGE computer analysis separated British isolates and clustered isolates in concordance with visual interpretation. Thirty-one of the 38 isolates (82%) were visually grouped in the same clusters by both molecular methods. The dominant strain was present in each of the three hospitals. CONCLUSIONS Bacteriophage typing was unhelpful for the analysis of Croatian MRSA, since most strains were untypable with the international set of bacteriophages. RAPD and PFGE were more successful in typing the organisms and showed evidence of inter-hospital spread of one predominant MRSA strain in all three Zagreb hospitals. Thus RAPD and PFGE proved to be a useful aid in elucidating the epidemiology of MRSA infection in Zagreb hospitals and should be established in Croatia for typing MRSA.
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Affiliation(s)
- A T Andrasevic
- Department of Clinical Microbiology, University Hospital of Infectious Diseases, Zagreb, CroatiaDepartment of Microbiology, King's College St Thomas' Hospital Campus, London, UKDepartment of Clinical Microbiology, Clinical Hospital Center Rebro, Zagreb, Croatia
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25
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Abstract
While lying down, a 23-year-old man detonated an improvised explosive device placed behind his head. The posterior neck and shoulders were singed, and much of the brain was avulsed. Death was due to laceration and partial avulsion of the cerebrum, midbrain, and brain stem. The injuries had a directional nature. Facts derived from the scene investigation and gross dissection, including nature, distribution, and extent of the wounds, in conjunction with preceding medical and social history, allowed for a reasonable reconstruction of the circumstances.
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Affiliation(s)
- E B Davis
- Department of Pathology, University of California, Davis, Sacramento, USA
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26
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Anthony RM, Connor AM, Power EG, French GL. Use of the polymerase chain reaction for rapid detection of high-level mupirocin resistance in staphylococci. Eur J Clin Microbiol Infect Dis 1999; 18:30-4. [PMID: 10192711 DOI: 10.1007/s100960050222] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The minimum inhibitory concentrations (MICs) of mupirocin were determined by the E test (AB Biodisk, Sweden) and the agar dilution method for 107 staphylococci. The organisms consisted of 34 coagulase-negative staphylococci and 73 methicillin-resistant Staphylococcus aureus. Polymerase chain reaction (PCR) primers designed to amplify a 456 bp region of the plasmid-borne isoleucyl tRNA synthetase gene (ileS-2), responsible for high-level mupirocin resistance in staphylococci, were used on DNA preparations from these isolates. Isolates with high-level mupirocin resistance due to the ileS-2 gene should be PCR positive. There was close correlation between the E test and agar dilution MIC values, with only two strains differing by more than two serial dilutions. Most (51 of 54 strains) of the high-level resistant strains (MIC>256 microg/ml) were resistant to the highest concentration of mupirocin tested (1024 microg/ml). PCR correctly classified all but four (96%) of the isolates in accordance with the results of agar dilution. All four isolates that gave discrepant results were methicillin-resistant Staphylococcus aureus. Two of these were PCR positive, yet the MIC of mupirocin for these strains was <0.06 microg/ml; on prolonged incubation they produced halos within the inhibition zone on agar diffusion testing, suggesting that the phenotypic results may have been erroneous. One of 54 isolates for which the MIC exceeded 256 microg/ml was PCR negative when tested by the original methodology, but a 456 bp product was produced when retested using a lowered annealing temperature. One isolate for which the MIC of mupirocin was 16 microg/ml by agar dilution and 8 microg/ml by the E test was positive by PCR. PCR of the ileS-2 gene is a useful, rapid method for detecting high-level mupirocin resistance in staphylococci.
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Affiliation(s)
- R M Anthony
- Department of Microbiology, University Medical and Dental School, St. Thomas' Hospital, London, UK
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27
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Tambic A, Power EG, Talsania H, Anthony RM, French GL. Analysis of an outbreak of non-phage-typeable methicillin-resistant Staphylococcus aureus by using a randomly amplified polymorphic DNA assay. J Clin Microbiol 1997; 35:3092-7. [PMID: 9399500 PMCID: PMC230128 DOI: 10.1128/jcm.35.12.3092-3097.1997] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A cluster of methicillin-resistant Staphylococcus aureus (MRSA) infections among patients on an intensive care unit (ICU) was detected by routine infection control surveillance. In the period from 5 January to 22 June 1995, 10 patients on the ICU and a further 6 patients (5 on one ward that had received colonized patients transferred from the ICU) were affected by MRSA strains with the same antibiotic susceptibility patterns. Seven (44%) of these 16 colonized patients developed MRSA bacteremia. MRSA isolates with the same characteristics were also found on the hands of one member of the ICU staff. The isolates were untypeable by phage typing, but 15 of 17 outbreak strains analyzed genetically had identical randomly amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) profiles. A single strain of MRSA that was nontypeable by phage typing and that was isolated on the ICU on 1 January and six nontypeable and epidemiologically unrelated MRSA isolates all had RAPD profiles distinct from that of the outbreak strain. Implementation of strict infection control measures stopped the further spread of MRSA on the ICU, the affected general ward, and seven other wards that received MRSA carriers from the ICU. Although nontypeable by phage typing and not previously recognized as an epidemic strain, this strain of MRSA was readily transmissible and highly virulent. RAPD typing was found to be a simple, rapid, and effective method for the epidemiological investigation of this outbreak, and performance of typing by this method was simpler and less time-consuming than that of typing by PFGE. RAPD typing may have more general application for the study of S. aureus infections in hospitals.
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Affiliation(s)
- A Tambic
- Department of Microbiology, UMDS of Guy's and St. Thomas's Hospitals, London, United Kingdom
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28
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Abstract
Venlafaxine is a phenethylamine derivative that has recently been approved for use in the treatment of depression. It is chemically unrelated to tricyclic, tetracyclic, or other available antidepressant agents. Anticholinergic, hypotensive, hypertensive, and cardiotoxic side effects are rare. Two fatal cases encountered at separate laboratories are discussed, both involve high levels of venlafaxine. Concentrations of the drug in peripheral blood, heart blood, urine, vitreous humor, and liver are reported. Descriptions of extraction and gas chromatographic methods for confirmation and quantitation are included.
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Affiliation(s)
- A T Parsons
- Laboratory of Forensic Services, Sacramento, California 95820, USA
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29
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Wilson JM, Kalasinsky KS, Levey AI, Bergeron C, Reiber G, Anthony RM, Schmunk GA, Shannak K, Haycock JW, Kish SJ. Striatal dopamine nerve terminal markers in human, chronic methamphetamine users. Nat Med 1996; 2:699-703. [PMID: 8640565 DOI: 10.1038/nm0696-699] [Citation(s) in RCA: 553] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Methamphetamine is a drug that is significantly abused worldwide, Although long-lasting depletion of dopamine and other dopamine nerve terminal markers has been reported in striatum of nonhuman primates receiving very high doses of the psychostimulant, no information is available for humans. We found reduced levels of three dopamine nerve terminal markers (dopamine, tyrosine hydroxylase and the dopamine transporter) in post-mortem striatum (nucleus accumbens, caudate, putamen) of chronic methamphetamine users. However, levels of DOPA decarboxylase and the vesicular monoamine transporter, known to be reduced in Parkinson's disease, were normal. This suggests that chronic exposure to methamphetamine does not cause permanent degeneration of striatal dopamine nerve terminals at the doses used by the young subjects in our study. However, the dopamine reduction might explain some of the dysphoric effects of the drug, whereas the decreased dopamine transporter could provide the basis for dose escalation occurring in some methamphetamine users.
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Affiliation(s)
- J M Wilson
- Human Neurochemical Pathology Laboratory, Clarke Institute of Psychiatry, Toronto, Ontario, Canada
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30
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Bond R, Anthony RM, Dodd M, Lloyd DH. Isolation of Malassezia sympodialis from feline skin. J Med Vet Mycol 1996; 34:145-147. [PMID: 8732361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Carriage of Malassezia yeasts was investigated in 17 cats in two colonies using a lipid-supplemented culture medium. Malassezia pachydermatis was isolated from one cat. Lipid-dependent Malassezia yeasts with electrophoretic karyotypes consistent with M. sympodialis were isolated from all six cats in one group and from one of 11 in the second group. To our knowledge, this is the first report of the isolation of lipid-dependent yeasts from cats.
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Affiliation(s)
- R Bond
- Department of Small Animal Medicine and Surgery, Royal Veterinary College, University of London, North Mimms, Hatfield, UK
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31
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Abstract
The genetic similarity of nineteen isolates of Candida albicans from four patients were compared by restriction fragment length polymorphism (RFLP) using EcoRI or HinfI, which both detected five types, and by random amplification of polymorphic DNA (RAPD), which detected three types. Phenotypically unusual isolates also produced distinct patterns with both typing systems demonstrating the carriage of two groups of C. albicans as well as the presence of more than one type in some subjects. Methods of DNA preparation were compared for the production of reproducible patterns; including using the supernatant fluid of boiled intact or spheroplasted cells for RAPD, and DNA precipitated from chloroform extracted cell lysate for RFLP and RAPD. Consistent patterns were produced from the DNA precipitate by RAPD and after an additional precipitation by RFLP, thus removing the necessity for lengthy extraction procedures or the use of toxic chemicals for purification.
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Affiliation(s)
- S A Howell
- Department of Microbial Diseases, St John's Institute of Dermatology, London, UK
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32
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Abstract
When 244 Malassezia colonies which had been isolated from a colony of Beagle dogs using modified Dixon's agar were sub-cultured on Sabouraud's dextrose agar to determine their lipid dependence, 30 showed poor growth resembling M. furfur, whereas the remainder were typical of M. pachydermatis. Eight of the 10 poor growing isolates selected for further study formed colonies typical of M. pachydermatis after five passages on Sabouraud's dextrose agar at 4 d intervals and two continued to show poor growth. Nine isolates had enzyme profiles identical to those of typical M. pachydermatis isolates, and one resembled M. furfur. However, seven of the poor growing isolates which were karyotyped had patterns typical of M. pachydermatis. Poor growing isolates and their non-lipid-dependent 'revertants' had identical restriction fragment length polymorphism patterns and poly(GT) hybridization profiles. These observations show that some M. pachydermatis isolates grow poorly when sub-cultured onto Sabouraud's dextrose agar and may be incorrectly identified as M. furfur if further studies are not performed.
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Affiliation(s)
- R Bond
- Department of Small Animal Medicine and Surgery, Royal Veterinary College, University of London, Hatfield, Herts, UK
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33
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34
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Abstract
Aerobic coryneform bacteria from human feet have been studied by analysis of the cell-wall sugars, lipids and diamino acids and by phenotypic tests. Although many isolates studied fall into the established genus Brevibacterium at least two previously unreported taxa of coryneform have been identified bringing the number of aerobic, non-lipophilic taxa known on skin to four. Simple tests can be used to distinguish between these taxa. Studies on the human skin flora continue to reveal the diversity of organisms present.
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Affiliation(s)
- R M Anthony
- Department of Microbial Diseases, St Thomas's Hospital, London, UK
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35
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Abstract
This report describes a headspace procedure suitable for the gas chromatographic assay of acetaldehyde, methanol, ethanol and various other volatile substances in biological samples. Carbopack B coated with 5% Carbowax 20-M is compared to Carbopack C coated with 0.2% Carbowax 1500. Assay range, linearity and precision are reported for the Carbopack B material.
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36
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Kelly RC, Anthony RM, Krent L, Thompson WL, Sunshine I. Toxicological determination of benzodiazepines in serum: methods and concentrations associated with high-dose intravenous therapy with diazepam. Clin Toxicol (Phila) 1979; 14:445-57. [PMID: 38030 DOI: 10.3109/15563657909010606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This paper describes a rapid and simple procedure for the determination of benzodiazepines in biological samples. Five common benzodiazepines (diazepam, oxazepam, clorazepate, flurazepam, and chlordiazepoxide) and/or their major metabolites are extracted from a buffered serum sample at pH 9.2 by a mixture of toluene, hexane, and isoamyl alcohol. The phases are separated by centrifugation, and a small aliquot of the organic layer is injected into a gas chromatograph equipped with an electron-capture detector. The drugs are identified and quantitated by comparison with standards simultaneously processed similarly. A sample can be analyzed in about 30 min. The technique is illustrated by its application to sequential samples from a patient being treated for delirium tremens with large intravenous doses of diazepam. Serum diazepam, N-desmethyldiazepam, and oxazepam concentrations several times higher than usually encountered therapeutically were observed.
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Abstract
An enzyme that mediates the decarboxylation of L-glutamic acid is endogenous to Physarum polycephalum. The enzyme is similar to mouse brain glutamate decarboxylase with respect to its Michaelis–Menton constant (2.1 × 10−3 M), pattern of response to increasing substrate concentrations, and the influence of halide anions on its activity. Its optimum pH range (5.6–6.0) is nearer the values reported by a variety of workers for preparations obtained from higher plants. The enzyme exhibits a thermal stability greater than that reported for the glutamate decarboxylase from any other organism, retaining full activity when heat-treated at temperatures as high as 60 °C.
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