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Rivas L, Duncan D, Wang J, Miller H, Wright J. Using CHROMagar™ STEC medium exclusively does not recover all clinically relevant Shiga toxin-producing Escherichia coli in Aotearoa, New Zealand. Lett Appl Microbiol 2024; 77:ovae033. [PMID: 38569656 DOI: 10.1093/lambio/ovae033] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/28/2024] [Accepted: 04/02/2024] [Indexed: 04/05/2024]
Abstract
Diagnostic laboratories in Aotearoa, New Zealand (NZ) refer cultures from faecal samples positive for Shiga toxin genes to the national Enteric Reference Laboratory for isolation of Shiga toxin-producing Escherichia coli (STEC) for epidemiological typing. As there was variation in the culture media being referred, a panel of 75 clinical isolates of STEC, representing 28 different serotypes, was used to assess six commercially available media and provide guidance to clinical laboratories. Recommendations were subsequently tested for a 3-month period, where STEC isolations and confirmations were assessed by whole genome sequencing analysis against the culture media referred. CHROMagar™ STEC (CH-STEC; CHROMagar Microbiology, Paris, France) or CH-STEC plus cefixime-tellurite sorbitol MacConkey agar was confirmed inferior to CH-STEC plus blood agar with vancomycin, cefsulodin, and cefixime (BVCC). The former resulted in fewer STEC types (n = 18) being confirmed compared to those from a combination of CH-STEC and BVCC (n = 42). A significant (P < .05) association with an STEC's ability to grow on CH-STEC and the presence of the ter gene cluster, and eae was observed. Culturing screen positive STEC samples onto both CH-STEC and BVCC ensures a consistently higher recovery of STEC from all clinical samples in NZ than CH-STEC alone.
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Affiliation(s)
- Lucia Rivas
- Institute of Environmental Science and Research (ESR), Christchurch Science Centre, 27 Creyke Road, Ilam, Christchurch 8041, New Zealand
| | - David Duncan
- Institute of Environmental Science and Research (ESR), Wallaceville Science Centre, 66 Ward Street, Wallaceville, Upper Hutt 5018, New Zealand
| | - Jing Wang
- Institute of Environmental Science and Research (ESR), Kenepuru Science Centre, 34 Kenepuru Drive, Kenepuru, Porirua 5022, New Zealand
| | - Hilary Miller
- Institute of Environmental Science and Research (ESR), Kenepuru Science Centre, 34 Kenepuru Drive, Kenepuru, Porirua 5022, New Zealand
| | - Jackie Wright
- Institute of Environmental Science and Research (ESR), Christchurch Science Centre, 27 Creyke Road, Ilam, Christchurch 8041, New Zealand
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Rubio S, Molinuevo R, Sanz-Gomez N, Zomorrodinia T, Cockrum CS, Luong E, Rivas L, Cadle K, Menendez J, Hinck L. Nuclear VANGL2 Inhibits Lactogenic Differentiation. Cells 2024; 13:222. [PMID: 38334614 PMCID: PMC10854645 DOI: 10.3390/cells13030222] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/10/2024] [Accepted: 01/14/2024] [Indexed: 02/10/2024] Open
Abstract
Planar cell polarity (PCP) proteins coordinate tissue morphogenesis by governing cell patterning and polarity. Asymmetrically localized on the plasma membrane of cells, transmembrane PCP proteins are trafficked by endocytosis, suggesting they may have intracellular functions that are dependent or independent of their extracellular role, but whether these functions extend to transcriptional control remains unknown. Here, we show the nuclear localization of transmembrane, PCP protein, VANGL2, in the HCC1569 breast cancer cell line, and in undifferentiated, but not differentiated, HC11 cells that serve as a model for mammary lactogenic differentiation. The loss of Vangl2 function results in upregulation of pathways related to STAT5 signaling. We identify DNA binding sites and a nuclear localization signal in VANGL2, and use CUT&RUN to demonstrate recruitment of VANGL2 to specific DNA binding motifs, including one in the Stat5a promoter. Knockdown (KD) of Vangl2 in HC11 cells and primary mammary organoids results in upregulation of Stat5a, Ccnd1 and Csn2, larger acini and organoids, and precocious differentiation; phenotypes are rescued by overexpression of Vangl2, but not Vangl2ΔNLS. Together, these results advance a paradigm whereby PCP proteins coordinate tissue morphogenesis by keeping transcriptional programs governing differentiation in check.
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Affiliation(s)
- Stefany Rubio
- Institute for the Biology of Stem Cells, University of California, Santa Cruz, CA 95064, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Rut Molinuevo
- Institute for the Biology of Stem Cells, University of California, Santa Cruz, CA 95064, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Natalia Sanz-Gomez
- Department of Cancer Biology, Institute for Biomedical Research “Alberto Sols”, 28029 Madrid, Spain
| | - Talieh Zomorrodinia
- Institute for the Biology of Stem Cells, University of California, Santa Cruz, CA 95064, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Chad S. Cockrum
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Elina Luong
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Lucia Rivas
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Kora Cadle
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Julien Menendez
- Institute for the Biology of Stem Cells, University of California, Santa Cruz, CA 95064, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Lindsay Hinck
- Institute for the Biology of Stem Cells, University of California, Santa Cruz, CA 95064, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
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Rubio S, Molinuevo R, Sanz-Gomez N, Zomorrodinia T, Cockrum CS, Luong E, Rivas L, Cadle K, Menendez J, Hinck L. Nuclear VANGL2 Inhibits Lactogenic Differentiation. bioRxiv 2023:2023.12.07.570706. [PMID: 38106173 PMCID: PMC10723439 DOI: 10.1101/2023.12.07.570706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Planar cell polarity (PCP) proteins coordinate tissue morphogenesis by governing cell patterning and polarity. Asymmetrically localized on the plasma membrane of cells, PCP proteins are also trafficked by endocytosis, suggesting they may have intracellular functions that are dependent or independent of their extracellular role, but whether these functions extend to transcriptional control remains unknown. Here, we show the nuclear localization of transmembrane, PCP protein, VANGL2, in undifferentiated, but not differentiated, HC11 cells, which serve as a model for mammary lactogenic differentiation. Loss of Vangl2 function results in upregulation of pathways related to STAT5 signaling. We identify DNA binding sites and a nuclear localization signal in VANGL2, and use CUT&RUN to demonstrate direct binding of VANGL2 to specific DNA binding motifs, including one in the Stat5a promoter. Knockdown (KD) of Vangl2 in HC11 cells and primary mammary organoids results in upregulation of Stat5a , Ccnd1 and Csn2 , larger acini and organoids, and precocious differentiation; phenotypes rescued by overexpression of Vangl2 , but not Vangl2 ΔNLS . Together, these results advance a paradigm whereby PCP proteins coordinate tissue morphogenesis by keeping transcriptional programs governing differentiation in check.
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4
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Leiva-Sabadini C, Tiozzo-Lyon P, Hidalgo-Galleguillos L, Rivas L, Robles AI, Fierro A, Barrera NP, Bozec L, Schuh CMAP, Aguayo S. Nanoscale Dynamics of Streptococcal Adhesion to AGE-Modified Collagen. J Dent Res 2023:220345231166294. [PMID: 37203151 DOI: 10.1177/00220345231166294] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
The adhesion of initial colonizers such as Streptococcus mutans to collagen is critical for dentinal and root caries progression. One of the most described pathological and aging-associated changes in collagen-including dentinal collagen-is the generation of advanced glycation end-products (AGEs) such as methylglyoxal (MGO)-derived AGEs. Despite previous reports suggesting that AGEs alter bacterial adhesion to collagen, the biophysics driving oral streptococcal attachment to MGO-modified collagen remains largely understudied. Thus, the aim of this work was to unravel the dynamics of the initial adhesion of S. mutans to type I collagen in the presence and absence of MGO-derived AGEs by employing bacterial cell force spectroscopy with atomic force microscopy (AFM). Type I collagen gels were treated with 10 mM MGO to induce AGE formation, which was characterized with microscopy and enzyme-linked immunosorbent assay. Subsequently, AFM cantilevers were functionalized with living S. mutans UA 159 or Streptococcus sanguinis SK 36 cells and probed against collagen surfaces to obtain force curves displaying bacterial attachment in real time, from which the adhesion force, number of events, Poisson analysis, and contour and rupture lengths for each individual detachment event were computed. Furthermore, in silico computer simulation docking studies between the relevant S. mutans UA 159 collagen-binding protein SpaP and collagen were computed, in the presence and absence of MGO. Overall, results showed that MGO modification increased both the number and adhesion force of single-unbinding events between S. mutans and collagen, without altering the contour or rupture lengths. Both experimental and in silico simulations suggest that this effect is due to increased specific and nonspecific forces and interactions between S. mutans UA 159 and MGO-modified collagen substrates. In summary, these results suggest that collagen alterations due to aging and glycation may play a role in early bacterial adherence to oral tissues, associated with conditions such as aging or chronic hyperglycemia, among others.
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Affiliation(s)
- C Leiva-Sabadini
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - P Tiozzo-Lyon
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - L Hidalgo-Galleguillos
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - L Rivas
- Genomics & Resistant Microbes group (GeRM), Instituto de Ciencias e Innovación en Medicina (ICIM), Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Concepción, Chile
- Millennium Initiative for Collaborative Research on Bacterial Resistance (MICROB-R)
| | - A I Robles
- Departamento de Química Orgánica, Escuela de Química, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - A Fierro
- Departamento de Química Orgánica, Escuela de Química, Facultad de Química y de Farmacia, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - N P Barrera
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - L Bozec
- Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada
| | - C M A P Schuh
- Centro de Medicina Regenerativa, Facultad de Medicina, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile
| | - S Aguayo
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
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5
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Billington C, Kingsbury JM, Rivas L. Metagenomics Approaches for Improving Food Safety: A Review. J Food Prot 2022; 85:448-464. [PMID: 34706052 DOI: 10.4315/jfp-21-301] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/21/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT Advancements in next-generation sequencing technology have dramatically reduced the cost and increased the ease of microbial whole genome sequencing. This approach is revolutionizing the identification and analysis of foodborne microbial pathogens, facilitating expedited detection and mitigation of foodborne outbreaks, improving public health outcomes, and limiting costly recalls. However, next-generation sequencing is still anchored in the traditional laboratory practice of the selection and culture of a single isolate. Metagenomic-based approaches, including metabarcoding and shotgun and long-read metagenomics, are part of the next disruptive revolution in food safety diagnostics and offer the potential to directly identify entire microbial communities in a single food, ingredient, or environmental sample. In this review, metagenomic-based approaches are introduced and placed within the context of conventional detection and diagnostic techniques, and essential considerations for undertaking metagenomic assays and data analysis are described. Recent applications of the use of metagenomics for food safety are discussed alongside current limitations and knowledge gaps and new opportunities arising from the use of this technology. HIGHLIGHTS
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Affiliation(s)
- Craig Billington
- Institute of Environmental Science and Research, 27 Creyke Road, Ilam, Christchurch 8041, New Zealand
| | - Joanne M Kingsbury
- Institute of Environmental Science and Research, 27 Creyke Road, Ilam, Christchurch 8041, New Zealand
| | - Lucia Rivas
- Institute of Environmental Science and Research, 27 Creyke Road, Ilam, Christchurch 8041, New Zealand
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6
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Mohan V, Cruz CD, van Vliet AHM, Pitman AR, Visnovsky SB, Rivas L, Gilpin B, Fletcher GC. Genomic diversity of Listeria monocytogenes isolates from seafood, horticulture and factory environments in New Zealand. Int J Food Microbiol 2021; 347:109166. [PMID: 33838478 DOI: 10.1016/j.ijfoodmicro.2021.109166] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 02/28/2021] [Accepted: 03/06/2021] [Indexed: 11/28/2022]
Abstract
Listeria monocytogenes is a foodborne human pathogen that causes systemic infection, fetal-placental infection in pregnant women causing abortion and stillbirth and meningoencephalitis in elderly and immunocompromised individuals. This study aimed to analyse L. monocytogenes from different sources from New Zealand (NZ) and to compare them with international strains. We used pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and whole-genome single nucleotide polymorphisms (SNP) to study the population structure of the NZ L. monocytogenes isolates and their relationship with the international strains. The NZ isolates formed unique clusters in PFGE, MLST and whole-genome SNP comparisons compared to the international isolates for which data were available. PFGE identified 31 AscI and 29 ApaI PFGE patterns with indistinguishable pulsotypes being present in seafood, horticultural products and environmental samples. Apart from the Asc0002:Apa0002 pulsotype which was distributed across different sources, other pulsotypes were site or factory associated. Whole-genome analysis of 200 randomly selected L. monocytogenes isolates revealed that lineage II dominated the NZ L. monocytogenes populations. MLST comparison of international and NZ isolates with lineage II accounted for 89% (177 of 200) of the total L. monocytogenes population, while the international representation was 45.3% (1674 of 3473). Rarefaction analysis showed that sequence type richness was greater in NZ isolates compared to international trend, however, it should be noted that NZ isolates predominantly came from seafood, horticulture and their respective processing environments or factories, unlike international isolates where there was a good mixture of clinical, food and environmental isolates.
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Affiliation(s)
- Vathsala Mohan
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand.
| | - Cristina D Cruz
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Arnoud H M van Vliet
- Department of Pathology and Infectious Diseases, School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Daphne Jackson Road, Guildford GU2 7AL, Surrey, United Kingdom
| | - Andrew R Pitman
- The New Zealand Institute for Plant & Food Research Limited, Lincoln, New Zealand.
| | - Sandra B Visnovsky
- The New Zealand Institute for Plant & Food Research Limited, Lincoln, New Zealand
| | - Lucia Rivas
- Institute of Environmental Science and Research Limited, Christchurch, New Zealand
| | - Brent Gilpin
- Institute of Environmental Science and Research Limited, Christchurch, New Zealand
| | - Graham C Fletcher
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
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7
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Abstract
The rate of yersiniosis in New Zealand (NZ) is high compared with other developed countries, and rates have been increasing over recent years. Typically, >99% of human cases in NZ are attributed to Yersinia enterocolitica (YE), although in 2014, a large outbreak of 220 cases was caused by Yersinia pseudotuberculosis. Up until 2012, the most common NZ strain was YE biotype 4. The emergent strain since this time is YE biotype 2/3 serotype O:9. The pathogenic potential of some YE biotypes remains unclear. Most human cases of yersiniosis are considered sporadic without an identifiable source. Key restrictions in previous investigations included insufficient sensitivity for the isolation of Yersinia spp. from foods, although foodborne transmission is the most likely route of infection. In NZ, YE has been isolated from a variety of sick and healthy domestic and farm animals but the pathways from zoonotic reservoir to human remain unproven. Whole-genome sequencing provides unprecedented discriminatory power for typing Yersinia and is now being applied to NZ epidemiological investigations. A "One-Health" approach is necessary to elucidate the routes of transmission of Yersinia and consequently inform targeted interventions for the prevention and management of yersiniosis in NZ.
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Affiliation(s)
- Lucia Rivas
- Christchurch Science Centre, Institute of Environmental Science and Research Limited, Ilam, Christchurch 8041, New Zealand;
| | - Hugo Strydom
- National Centre for Biosecurity and Infectious Disease, Institute of Environmental Science and Research Limited, Upper Hutt, Wellington 5018, New Zealand;
| | - Shevaun Paine
- Kenepuru Science Centre, Institute of Environmental Science and Research Limited, Porirua, Wellington 5022, New Zealand; (S.P.); (J.W.)
| | - Jing Wang
- Kenepuru Science Centre, Institute of Environmental Science and Research Limited, Porirua, Wellington 5022, New Zealand; (S.P.); (J.W.)
| | - Jackie Wright
- National Centre for Biosecurity and Infectious Disease, Institute of Environmental Science and Research Limited, Upper Hutt, Wellington 5018, New Zealand;
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Rivas L, Dupont PY, Gilpin B, Withers H. Prevalence and Genotyping of Campylobacter jejuni and Campylobacter coli from Ovine Carcasses in New Zealand. J Food Prot 2021; 84:14-22. [PMID: 32766835 DOI: 10.4315/jfp-20-220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/03/2020] [Indexed: 02/03/2023]
Abstract
ABSTRACT A pilot survey was performed to determine the prevalence of Campylobacter jejuni and Campylobacter coli on three age classes (lamb, hogget, and mutton) of ovine carcass trim postdressing and prechill. Sampling of hogget carcasses was undertaken 6 months before sampling of lamb and mutton carcasses. A total of 120 trim samples were collected from 11 processing plants across New Zealand. All samples were enriched and screened using PCR for the presence of C. jejuni and C. coli, and isolation was attempted for all screen-positive samples. Enumeration of Campylobacter from lamb trim samples showed that Campylobacter bacteria were present in very low numbers (<10 CFU/g). The overall prevalence of Campylobacter for ovine trim based on PCR detection was 33% (39 of 120 samples), with prevalences for hogget, lamb, and mutton carcass trim of 56% (28 of 50), 11% (4 of 35), and 20% (7 of 35), respectively. Whole genome sequencing was performed on a selection of C. jejuni and C. coli isolates, and the data were used to subtype using multilocus sequence typing (MLST) and whole genome MLST. Twenty-five MLST sequence types (STs) were identified among 44 isolates, including ST42, ST50, ST3222, and ST3072, which have been previously reported to be associated with ruminant sources. Four novel STs were also identified. Whole genome MLST analysis further discriminated isolates within a single ST type and demonstrated a genetic diversity among the ovine isolates collected. Genes associated with the oxacillinase class of β-lactamase enzymes were identified in 41 of 44 Campylobacter isolates. This study provides preliminary data that can be incorporated into existing source attribution models to assist in determining the potential contribution of ovine sources to the burden of campylobacteriosis in New Zealand. HIGHLIGHTS
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Affiliation(s)
- Lucia Rivas
- Institute of Environmental Science and Research, P.O. Box 29181, Christchurch, 8053, New Zealand (ORCID: https://orcid.org/0000-0001-9666-495X [L.R.])
| | - Pierre-Yves Dupont
- Institute of Environmental Science and Research, P.O. Box 29181, Christchurch, 8053, New Zealand (ORCID: https://orcid.org/0000-0001-9666-495X [L.R.])
| | - Brent Gilpin
- Institute of Environmental Science and Research, P.O. Box 29181, Christchurch, 8053, New Zealand (ORCID: https://orcid.org/0000-0001-9666-495X [L.R.])
| | - Helen Withers
- New Zealand Food Safety, Ministry for Primary Industries, P.O. Box 2526, Wellington, 6140, New Zealand
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Gilpin BJ, Walker T, Paine S, Sherwood J, Mackereth G, Wood T, Hambling T, Hewison C, Brounts A, Wilson M, Scholes P, Robson B, Lin S, Cornelius A, Rivas L, Hayman DT, French NP, Zhang J, Wilkinson DA, Midwinter AC, Biggs PJ, Jagroop A, Eyre R, Baker MG, Jones N. A large scale waterborne Campylobacteriosis outbreak, Havelock North, New Zealand. J Infect 2020; 81:390-395. [DOI: 10.1016/j.jinf.2020.06.065] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/19/2020] [Accepted: 06/26/2020] [Indexed: 12/17/2022]
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Rivas L, Dupont PY, Gilpin BJ, Cornelius AJ. Isolation and characterization of Clostridium difficile from a small survey of wastewater, food and animals in New Zealand. Lett Appl Microbiol 2019; 70:29-35. [PMID: 31631350 DOI: 10.1111/lam.13238] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 10/17/2019] [Accepted: 10/17/2019] [Indexed: 11/29/2022]
Abstract
The objective of this study was to undertake a microbiological survey of foods, animal faeces and wastewater samples for Clostridium difficile, and determine the genotypes and antimicrobial susceptibilities of isolates. A total of 211 samples were tested for C. difficile using culture methods. Thirteen toxigenic C. difficile isolates were obtained; ten from wastewater samples, one each from pig and duck faeces and another from a raw meat product. Eight PCR-ribotypes (RTs) were identified, including two novel RTs (878 and 879). Single-nucleotide polymorphism analysis using WGS data for all isolates provided greater discrimination between C. difficile isolates within the same RT and multilocus sequence typing (MLST) profiles. All C. difficile isolates were found to be susceptible to the first-line human antimicrobials used to treat C. difficile infection. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study to report the isolation of Clostridium difficile from animals, food and wastewater in New Zealand (NZ) and provides important data with respect to ribotypes and multilocus sequence typing profiles, whole genome sequence and antimicrobial susceptibilities. The results highlight the need for further investigations into the epidemiology of C. difficile in NZ and to elucidate the role of the environmental and food sources as transmission routes of human infection.
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Affiliation(s)
- L Rivas
- Health and Environment, Institute of Environmental Science and Research, Christchurch Science Centre, Christchurch, New Zealand
| | - P-Y Dupont
- Health and Environment, Institute of Environmental Science and Research, Christchurch Science Centre, Christchurch, New Zealand
| | - B J Gilpin
- Health and Environment, Institute of Environmental Science and Research, Christchurch Science Centre, Christchurch, New Zealand
| | - A J Cornelius
- Health and Environment, Institute of Environmental Science and Research, Christchurch Science Centre, Christchurch, New Zealand
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Rivas L, Dupont P, Wilson M, Rohleder M, Gilpin B. An outbreak of multiple genotypes of
Listeria monocytogenes
in New Zealand linked to contaminated ready‐to‐eat meats—a retrospective analysis using whole‐genome sequencing. Lett Appl Microbiol 2019; 69:392-398. [DOI: 10.1111/lam.13227] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 12/18/2022]
Affiliation(s)
- L. Rivas
- Institute of Environmental Science and Research Christchurch New Zealand
| | - P.‐Y. Dupont
- Institute of Environmental Science and Research Christchurch New Zealand
| | - M. Wilson
- Institute of Environmental Science and Research Christchurch New Zealand
| | - M. Rohleder
- Hawke’s Bay District Health Board Hastings New Zealand
| | - B. Gilpin
- Institute of Environmental Science and Research Christchurch New Zealand
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12
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López-García JS, García-Lozano I, Rivas L, Giménez C, Suárez-Cortés T, Acera A. Changes in Corneal Expression of MUC5AC after Autologous Serum Eyedrop Treatment in Patients with Limbal Stem Cell Deficiency. Curr Eye Res 2019; 44:934-940. [DOI: 10.1080/02713683.2019.1607394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
| | | | - L Rivas
- Dry Eye Unit, Research Laboratory, Ophthalmology Service, Hospital Ramón y Cajal, Madrid, Spain
| | - C Giménez
- Ophthalmology Service, Hospital de Parla, Madrid, Spain
| | | | - A Acera
- Applied Research, Vizcaya, Spain
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Abstract
Purpose This work describes the snake-like chromatin cells in the conjunctiva of patients with keratoconjunctivitis sicca (KCS), assessing the relationship between tear function parameters and the severity of the disease, and searching for any differential pattern that could lead to early and diagnosis help clarify the etiology of KCS. Methods The conjunctiva of 366 eyes from 187 patients with KCS, and 30 eyes from 15 controls, were classified according to the results of the Schirmer I test, break-up time, rose Bengal staining, osmolarity, ferning tests and electrophoresis; they were then studied by impression cytology and electron microscopy. Results Snake-like chromatin cells, other nuclear changes, and a decreased number of goblet cells were found by impression cytology in different areas of the KCS conjunctiva. The presence of snake-like chromatin was significantly correlated with the severity of the disease. No nuclear changes were found in the control group. Conclusions We assume these findings can be attributed to a natural regeneration of conjunctival cells and to resistance to a pathological reaction to KCS.
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Affiliation(s)
- L Rivas
- Department of Ophthalmology, Dacryology Laboratory, Ramón y Cajal Hospital, Madrid, Spain
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14
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Rivas L, Toledano A, Alvarez MI, Sanz AI, Oroza MA, Murube J. Ultrastructural Study of the Conjunctiva in Patients with Keratoconjunctivitis Sicca not Associated with Systemic Disorders. Eur J Ophthalmol 2018; 8:131-6. [PMID: 9793764 DOI: 10.1177/112067219800800302] [Citation(s) in RCA: 9] [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: 11/17/2022]
Abstract
Purpose The aim of this work was to evaluate ultrastructural alterations of the conjunctiva during the clinical course of keratoconjunctivitis sicca (KCS), and to detect its earliest and most characteristic morphological changes. Methods The conjunctiva was studied in biopsies from 75 patients and 10 controls. Patients were classified according to the results of the Schirmer I test, break-up time, rose Bengal staining, osmolarity and impression cytology. Results The conjunctiva in these KCS patients showed progressive hyperplasia, hypertrophy and cellular flattening, with diminution of goblet cell density and microvilli. In the severe cases, the epithelial cells lost their organelles, and fibrous material increased. From the early phases of KCS, clear nuclear alterations (indentation, binucleation) were found, but pyknotic nuclei or anucleated cells were only observed in the most severe cases. From the earliest stages to the most severe cases of KCS, decreases in cell membrane interdigitations were observed parallel to increases in the number and size of desmosomes. There were also increases in the number of inflammatory cells. Alterations in blood vessels were only observed in the most severe cases. Conclusions Morphological studies alone were able even in the earliest phases of KCS, to detect the squamous metaplasia that progresses from the surface of the epithelium to the connective tissue. This degenerative or adaptative cellular process was characterized mainly by marked proliferation of the cytoskeleton and a general loss of organelles, mitochondria being the least affected.
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Affiliation(s)
- L Rivas
- Department of Ophthalmology, Ramón y Cajal Hospital, Madrid, Spain
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Díaz-Delgado J, Coimbra AAC, Dos Santos-Cirqueira C, Sanches TC, Guerra JM, de Oliveira AS, Di Loretto C, Zwarg T, Ressio R, Rivas L, Sansone M, Nagamori FO, Kanamura C, Gonçalves PS, Fernandes NCCA, Groch KR, Catão-Dias JL. Parotid Salivary Gland Basal Cell Adenocarcinoma in a Big-eared Opossum (Didelphis aurita). J Comp Pathol 2018; 159:21-25. [PMID: 29599001 DOI: 10.1016/j.jcpa.2017.12.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 12/24/2017] [Accepted: 12/27/2017] [Indexed: 11/18/2022]
Abstract
The opossum (family Didelphidae) is a marsupial endemic to the Americas. Apart from the South American short-tailed opossum (Monodelphis domestica) and the Virginia opossum (Didelphis virginiana), there is considerable lack of knowledge about the health and diseases of most opossum species. Among these, the big-eared opossum (Didelphis aurita) is found in Argentina, Brazil and Paraguay. Natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic potential and the animals may play a role in transmission of such agents. However, neoplasia appears to be uncommon in this species. We describe the gross, microscopical and immunohistochemical features of a parotid salivary gland basal cell adenocarcinoma in a free-living big-eared opossum. This case represents the first report of salivary gland neoplasia in opossums.
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Affiliation(s)
- J Díaz-Delgado
- Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, São Paulo, Brazil; Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil.
| | - A A C Coimbra
- Divisão Técnica de Medicina Veterinária e Manejo da Fauna Silvestre, IV Portão 7A, Av. Quarto Centenário, Parque Ibirapuera, São Paulo, São Paulo, Brazil
| | - C Dos Santos-Cirqueira
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - T C Sanches
- Divisão Técnica de Medicina Veterinária e Manejo da Fauna Silvestre, IV Portão 7A, Av. Quarto Centenário, Parque Ibirapuera, São Paulo, São Paulo, Brazil
| | - J M Guerra
- Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, São Paulo, Brazil
| | - A S de Oliveira
- Divisão Técnica de Medicina Veterinária e Manejo da Fauna Silvestre, IV Portão 7A, Av. Quarto Centenário, Parque Ibirapuera, São Paulo, São Paulo, Brazil
| | - C Di Loretto
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - T Zwarg
- Divisão Técnica de Medicina Veterinária e Manejo da Fauna Silvestre, IV Portão 7A, Av. Quarto Centenário, Parque Ibirapuera, São Paulo, São Paulo, Brazil
| | - R Ressio
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - L Rivas
- Divisão Técnica de Medicina Veterinária e Manejo da Fauna Silvestre, IV Portão 7A, Av. Quarto Centenário, Parque Ibirapuera, São Paulo, São Paulo, Brazil
| | - M Sansone
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - F O Nagamori
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - C Kanamura
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - P S Gonçalves
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - N C C A Fernandes
- Instituto Adolfo Lutz, Centro de Patologia, Brasil, Av. Dr. Arnaldo, 351 - 7 Andar, Sala 706, Pacaembú, São Paulo, São Paulo, Brazil
| | - K R Groch
- Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, São Paulo, Brazil
| | - J L Catão-Dias
- Departamento de Patologia, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Orlando Marques de Paiva 87, São Paulo, São Paulo, Brazil
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Rivas L, Horn B, Cook R, Castle M. Microbiological Survey of Packaged Ready-to-Eat Red Meats at Retail in New Zealand. J Food Prot 2017; 80:1806-1814. [PMID: 28981376 DOI: 10.4315/0362-028x.jfp-17-179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/21/2017] [Indexed: 11/11/2022]
Abstract
A microbiological survey was undertaken on packaged ready-to-eat red meats available at retail in New Zealand. A total of 1,485 samples (297 lots of five samples each) were collected according to a sampling plan based on market share and regulatory regimes (Animal Products Act 1999 and Food Act 1981) and were tested against the microbiological limits specified in Food Standards Code (FSC) 1.6.1 applicable at the time of sampling. Each lot was tested as a composite for the presence or absence of Salmonella spp., coagulase-producing staphylococci, Listeria monocytogenes, and other Listeria spp. at the end of the manufacturer's stated shelf life. Individual samples within a positive lot were subsequently enumerated for L. monocytogenes. None of the samples contained Salmonella spp. or had coagulase-producing staphylococci counts above the acceptable level specified in FSC 1.6.1 (>100 CFU/g). Data showed that 93.6% (278 of 297 lots) of ready-to-eat red meat complied with the FSC 1.6.1 criteria applicable at the time of the survey. The failure of 19 lots (6.4%) was due to the presence of L. monocytogenes from product obtained from 8 of 33 producers tested. Thirteen samples of 95 positive samples were found to contain between 50 and 500 CFU/g L. monocytogenes, but all of these samples were manufactured by the same operator. Pulsed-field gel electrophoresis typing of all of the L. monocytogenes isolates obtained from the survey identified 12 different pulsotypes. Different pulsotypes were often identified in samples from the same operator sampled on separate occasions. A total of 46 lots (15.5%) contained Listeria spp. (including L. monocytogenes). The detection of Listeria in samples may highlight the existence of problems in operator processing and/or packaging processes and suggests that improvements in good hygienic practice and implementation of more effective risk mitigation strategies are needed.
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Affiliation(s)
- Lucia Rivas
- Institute of Environmental Science and Research, Christchurch Science Centre, 27 Creyke Road, Ilam, Christchurch 8041, New Zealand; and
| | - Beverley Horn
- Institute of Environmental Science and Research, Christchurch Science Centre, 27 Creyke Road, Ilam, Christchurch 8041, New Zealand; and
| | - Roger Cook
- Ministry for Primary Industries, Pastoral House, P.O. Box 2526, Wellington 6140, New Zealand
| | - Marion Castle
- Ministry for Primary Industries, Pastoral House, P.O. Box 2526, Wellington 6140, New Zealand
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Herruzo R, Ruiz G, Vizcaino M, Rivas L, Pérez-Blanco V, Sanchez M. Microbial competition in environmental nosocomial reservoirs and diffusion capacity of OXA48- Klebsiella pneumoniae: potential impact on patients and possible control methods. J Prev Med Hyg 2017; 58:E34-E41. [PMID: 28515629 PMCID: PMC5432776] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND We have found clusters of Klebsiella pneumoniae with OXA48-carbepenemase cases in some hospital rooms, and decided to investigate whether bathroom siphons could be a reservoir for OXA48 bacteria, as occurs with K. oxytoca with other types of carbepenemases. METHODS We evaluated the microbial competition between strains with OXA48 and VIM carbepenemases, in diluted nutrient-broth, on a slime germ-carrier. We compared the number of colonies at 5 and 10 days on the contaminated carriers with one or two strains. We evaluated the dissemination of K. pneumoniae with carbepenemase OXA48 or VIM from thumbs and index fingers of volunteers, to standard surfaces (20 glass germ-carrier by each volunteer). After, we counted the number of microorganisms on each carrier. Microbiological weekly studies of faecal microbiota of all patients were obtained in Traumatology and Oncology. Moreover, we studied samples of the sink in their rooms. PCR and MLST sequence-type was determined in all K. pneumoniae diagnosed from patients and sinks. RESULTS A large possibility of diffusion from contaminated hands, which continue to transmit high numbers of microorganisms after more than 10 successive surface contacts, was highlighted; OXA bacteria were more persistent than VIM bacteria. Microbial competition studies showed that VIM bacteria are inhibited by OXA ones. These observations can explain the concentration of cases of K. pneumoniae OXA48 in some rooms in Traumatology and Oncology, producing a significant OR between rooms with OXA48-bacteria-contaminated siphons and other rooms (3.1 and 3.3 respectively). Risk was lowered after changing or disinfecting (heat plus chlorinated disinfectant) the contaminated siphons. Siphon colonization by VIM bacteria was not related with human infections by similar microorganisms. CONCLUSIONS Bathroom siphons can be a reservoir for K. pneumoniae OXA48 and lead to outbreaks. Outbreaks can be controlled by replacement or heat plus chemical treatment of the sink-siphons.
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Affiliation(s)
- R. Herruzo
- Departamento de Medicina Preventiva y Salud Pública y Microbiologia, UAM, Madrid;,Correspondence: Rafael Herruzo, Department of Preventive Medicine and Public Health and Microbiology. School of Medicine. Universidad Autónoma de Madrid C/Arzobispo Morcillo 4, 28029 Madrid, Spain - E-mail:
| | - G. Ruiz
- Servicio de Microbiología Hospital Universitario La Paz, Madrid
| | - M.J. Vizcaino
- Departamento de Medicina Preventiva y Salud Pública y Microbiologia, UAM, Madrid
| | - L. Rivas
- Servicio de Medicina Preventiva, HU La Paz, Madrid
| | | | - M. Sanchez
- Unidad de Cuidados Intensivos, HU La Paz, Madrid, Spain
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Ravalli A, Rivas L, De la Escosura-Muñiz A, Pons J, Merkoçi A, Marrazza G. A DNA Aptasensor for Electrochemical Detection of Vascular Endothelial Growth Factor. J Nanosci Nanotechnol 2015; 15:3411-3416. [PMID: 26504959 DOI: 10.1166/jnn.2015.10037] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Electrochemical aptasensors can detect different cancer biomarkers to provide point-of-care diagnosis that is low cost, rapid, specific and sensitive. In this work, we described the development of an electrochemical single-use aptasensor for detection and analysis of vascular endothelial growth factor (VEGF). Gold nanostructured graphite screen-printed electrodes were firstly modified with a mixed monolayer of a primary thiolated DNA aptamer and a spacer thiol, 6-mercapto-1-hexanol. VEGF protein was then incubated with the aptasensor. An enzyme-amplified detection scheme, based on the coupling of a streptavidin-alkaline phosphatase conjugate and secondary biotinylated aptamer was then applied. The enzyme catalyzed the hydrolysis of the electroinactive 1 -naphthyl-phosphate to 1 -naphthol; this product is electroactive and has been detected by means of differential pulse voltammetry (DPV). The aptasensor response was found to be linearly related to the target concentration between 0 and 250 nmol L(-1); the detection limit was 30 nmol L(-1). The performance of the immunoassay in terms of reproducibility and selectivity has been also studied.
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Tiwari U, Walsh D, Rivas L, Jordan K, Duffy G. Modelling the interaction of storage temperature, pH, and water activity on the growth behaviour of Listeria monocytogenes in raw and pasteurised semi-soft rind washed milk cheese during storage following ripening. Food Control 2014. [DOI: 10.1016/j.foodcont.2014.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Rivas L, Blázquez A, Muñoz-Negrete FJ, López S, Rebolleda G, Domínguez F, Pérez-Esteban A. [Characterization of epithelial primary culture from human conjunctiva]. ACTA ACUST UNITED AC 2013; 89:10-6. [PMID: 24269413 DOI: 10.1016/j.oftal.2013.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 07/26/2013] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To evaluate primary cultures from human conjunctiva supplemented with fetal bovine serum, autologous serum, and platelet-rich autologous serum, over human amniotic membrane and lens anterior capsules. METHODS One-hundred and forty-eight human conjunctiva explants were cultured in CnT50(®) supplemented with 1, 2.5, 5 and 10% fetal bovine serum, autologous serum and platelet-rich autologous serum. Conjunctival samples were incubated at 37°C, 5% CO2 and 95% HR, for 3 weeks. RESULTS The typical phenotype corresponding to conjunctival epithelial cells was present in all primary cultures. Conjunctival cultures had MUC5AC-positive secretory cells, K19-positive conjunctival cells, and MUC4-positive non-secretory conjunctival cells, but were not corneal phenotype (cytokeratin K3-negative) and fibroblasts (CD90-negative). CONCLUSIONS Conjunctiva epithelial progenitor cells were preserved in all cultures; thus, a cell culture in CnT50(®) supplemented with 1 to 5% autologous serum over human amniotic membrane can provide better information of epithelial cell differentiation for the conjunctival surface reconstruction.
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Affiliation(s)
- L Rivas
- Servicio de Oftalmología, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, España.
| | - A Blázquez
- Laboratorio de Ingeniería Celular, Hospital Universitario La Paz, Madrid, España
| | - F J Muñoz-Negrete
- Servicio de Oftalmología, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, España
| | - S López
- Servicio de Oftalmología, Hospital Central de la Cruz Roja, Madrid, España
| | - G Rebolleda
- Servicio de Oftalmología, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, España
| | - F Domínguez
- Laboratorio de Ingeniería Celular, Hospital Universitario La Paz, Madrid, España
| | - A Pérez-Esteban
- Servicio de Oftalmología, Hospital Universitario La Paz, Madrid, España
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McDonnell MJ, Rivas L, Burgess CM, Fanning S, Duffy G. Evaluation of Carvacrol for the Control of Escherichia coli O157 on Cattle Hide and Carcass Cuts. Foodborne Pathog Dis 2012; 9:1049-52. [DOI: 10.1089/fpd.2012.1224] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Mary J. McDonnell
- Teagasc Food Research Centre, Ashtown, Dublin, Ireland
- UCD Centre for Food Safety, School of Public Health, Physiotherapy and Population Science, Veterinary Sciences Centre, University College Dublin, Belfield, Dublin, Ireland
| | - Lucia Rivas
- Teagasc Food Research Centre, Ashtown, Dublin, Ireland
| | | | - Séamus Fanning
- UCD Centre for Food Safety, School of Public Health, Physiotherapy and Population Science, Veterinary Sciences Centre, University College Dublin, Belfield, Dublin, Ireland
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McDonnell MJ, Rivas L, Burgess CM, Fanning S, Duffy G. Inhibition of verocytotoxigenic Escherichia coli by antimicrobial peptides caseicin A and B and the factors affecting their antimicrobial activities. Int J Food Microbiol 2011; 153:260-8. [PMID: 22177226 DOI: 10.1016/j.ijfoodmicro.2011.10.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 08/11/2011] [Accepted: 10/01/2011] [Indexed: 11/16/2022]
Abstract
The antimic robial activities of caseicin A and B antimicrobial peptides (AMPs) were assessed against a selection of verocytotoxigenic Escherichia coli (VTEC) strains (n=11), other bacterial pathogenic and spoilage bacteria (n=7), using a model broth system. The ability of the AMPs to retain their antimicrobial activities against a strain of E. coli O157:H7 380-94 under various test conditions (pH, temperature, water activity, sodium chloride concentrations, inoculum size and the presence of competitive microflora) was assessed and the minimum inhibitory concentrations (MIC) and number of surviving E. coli O157:H7 calculated. The mean number of VTEC surviving after exposure to 2 mg/ml caseicin A and B was reduced by 4.96 and 4.19 log(10) cfu/ml compared to the respective controls. The susceptibility of E. coli O157:H7 to the caseicin AMPs decreased as temperature, pH, water activity and inoculum size were reduced. The presence of sodium chloride (0.5-2.5%) did not affect the activity of caseicin A (p>0.05), however it did inhibit the activity of caseicin B. The presence of a competitive microflora cocktail did not significantly (p>0.05) affect the activities of the AMPs for the majority of the concentrations tested. Using a quantitative PCR assay, the levels of verotoxins (vt1 and vt2) expressed by E. coli O157:H7 following exposure to a sub-inhibitory concentration (0.5 mg/ml) of caseicin A showed that the verotoxin levels did not differ from the levels produced by the control cultures. The antimicrobial activity of caseicin A against E. coli O157:H7 was also tested in a model rumen system, however concentrations of ≥2 mg/ml did not significantly (p>0.05) reduce E. coli O157:H7 numbers in the model system over a 24 h period. The application of caseicin AMPs in food and/or animal production may be valuable in combination with other antimicrobials although further research is required.
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Coffey B, Rivas L, Duffy G, Coffey A, Ross RP, McAuliffe O. Assessment of Escherichia coli O157:H7-specific bacteriophages e11/2 and e4/1c in model broth and hide environments. Int J Food Microbiol 2011; 147:188-94. [DOI: 10.1016/j.ijfoodmicro.2011.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 03/28/2011] [Accepted: 04/05/2011] [Indexed: 10/18/2022]
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López-Rojas R, Docobo-Pérez F, Pachón-Ibáñez ME, de la Torre BG, Fernández-Reyes M, March C, Bengoechea JA, Andreu D, Rivas L, Pachón J. Efficacy of cecropin A-melittin peptides on a sepsis model of infection by pan-resistant Acinetobacter baumannii. Eur J Clin Microbiol Infect Dis 2011; 30:1391-8. [PMID: 21479973 DOI: 10.1007/s10096-011-1233-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 03/19/2011] [Indexed: 02/02/2023]
Abstract
Pan-resistant Acinetobacter baumannii have prompted the search for therapeutic alternatives. We evaluate the efficacy of four cecropin A-melittin hybrid peptides (CA-M) in vivo. Toxicity was determined in mouse erythrocytes and in mice (lethal dose parameters were LD(0), LD(50), LD(100)). Protective dose 50 (PD(50)) was determined by inoculating groups of ten mice with the minimal lethal dose of A. baumannii (BMLD) and treating with doses of each CA-M from 0.5 mg/kg to LD(0). The activity of CA-Ms against A. baumannii was assessed in a peritoneal sepsis model. Mice were sacrificed at 0 and 1, 3, 5, and 7-h post-treatment. Spleen and peritoneal fluid bacterial concentrations were measured. CA(1-8)M(1-18) was the less haemolytic on mouse erythrocytes. LD(0) (mg/kg) was 32 for CA(1-8)M(1-18), CA(1-7)M(2-9), and Oct-CA(1-7)M(2-9), and 16 for CA(1-7)M(5-9). PD(50) was not achieved with non-toxic doses (≤ LD(0)). In the sepsis model, all CA-Ms were bacteriostatic in spleen, and decreased bacterial concentration (p < 0.05) in peritoneal fluid, at 1-h post-treatment; at later times, bacterial regrowth was observed in peritoneal fluid. CA-Ms showed local short-term efficacy in the peritoneal sepsis model caused by pan-resistant Acinetobacter baumannii.
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Affiliation(s)
- R López-Rojas
- Unidad Clínica de Enfermedades Infecciosas, Instituto de Biomedicina de Sevilla, IBIS/Hospital Universitario Virgen del Rocío/Universidad de Sevilla/CSIC Sevilla, 41013 Sevilla, Spain.
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Nguyen VT, Flanagan B, Mikkelsen D, Ramirez S, Rivas L, Gidley MJ, Dykes GA. Spontaneous mutation results in lower cellulose production by a Gluconacetobacter xylinus strain from Kombucha. Carbohydr Polym 2010. [DOI: 10.1016/j.carbpol.2009.11.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lozano N, Pérez L, Pons R, Luque-Ortega J, Fernández-Reyes M, Rivas L, Pinazo A. Erratum to “Interaction studies of diacyl glycerol arginine-based surfactants with DPPC and DMPC monolayers, relation with antimicrobial activity” [Colloids Surf. A: Physicochem. Eng. Aspects 319 (2008) 196–203]. Colloids Surf A Physicochem Eng Asp 2009. [DOI: 10.1016/j.colsurfa.2009.08.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Saavedra N, Riquelme I, Rivas L, Jaramillo P, Caamaño J, Lanas C, Lanas F, Salazar LA. D 014 A148g Variant of Pon2 Gene in Chilean Individuals with Coronary Disease Confirmed by Angiography and Controls. ATHEROSCLEROSIS SUPP 2009. [DOI: 10.1016/s1567-5688(09)71708-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Oroza MA, Calcicedo L, Sanchez-Franco F, Rivas L. Hormonal, Hematological and Serum Chemistry Effects of Weak Pulsed Electromagnetic Fields on Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/15368378709027734] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Rivas L, Fegan N, Dykes GA. Expression and Putative Roles in Attachment of Outer Membrane Proteins ofEscherichia coliO157 from Planktonic and Sessile Culture. Foodborne Pathog Dis 2008; 5:155-64. [DOI: 10.1089/fpd.2007.0052] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Lucia Rivas
- Food Science Australia, Brisbane, Queensland, Australia
- School of Land, Crop and Food Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Narelle Fegan
- Food Science Australia, Brisbane, Queensland, Australia
| | - Gary A. Dykes
- Food Science Australia, Brisbane, Queensland, Australia
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López-García JS, Rivas L, García-Lozano I, Murube J. Autologous Serum Eyedrops in the Treatment of Aniridic Keratopathy. Ophthalmology 2008; 115:262-7. [PMID: 17675158 DOI: 10.1016/j.ophtha.2007.03.087] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [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: 08/25/2006] [Revised: 03/30/2007] [Accepted: 03/30/2007] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To study the effect of autologous serum eyedrop application in aniridic keratopathy. DESIGN Prospective, consecutive, comparative, interventional case series. PARTICIPANTS Twenty-six eyes from 13 patients (7 males and 6 females) with aniridic keratopathy treated with autologous serum eyedrops. METHODS All patients underwent a complete ophthalmic examination. The ocular surface examinations included corneal impression cytologic analysis and tear film evaluation. The eyes were divided into 4 groups according to the Mackman classification. Ocular surface photography was used to evaluate the corneal surface and tear film before treatment and every 2 or 3 days until serum drops were stopped. Tear films were evaluated by tear film break-up time (BUT) (normal, 10 seconds or more), Schirmer's test with anesthesia (normal, 10 mm/5 minutes or more), tear meniscus level (normal, 0.5 mm or more), and rose bengal and fluorescein staining pattern of the cornea. Impression cytologic analysis was carried out both before starting the serum eyedrops treatment and a few days after its finalization. MAIN OUTCOMES MEASURES Tear film production and stability, corneal epithelialization, and corneal epithelium squamous metaplasia. RESULTS There were no local side effects from autologous serum treatment. Clinical manifestations and slit-lamp findings were in relation to the severity of keratopathy. All patients showed a subjective improvement of keratopathy symptoms after the autologous serum applications. The corneal epithelialization, corneal epithelial cell squamous metaplasia, and tear stability improved significantly with the treatment, but visual acuity, regression of vascular pannus, and subepithelial scarring showed only slight improvement with treatment. CONCLUSIONS Autologous serum eyedrops improved the aniridic keratopathy in all patients, particularly in patients with light or moderate severity. In these patients, use of autologous serum eyedrops was superior to conventional therapy with substitute tears for improving the ocular surface and subjective comfort.
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Abstract
OBJECTIVE To establish a protocol for the use of autologous serum in the ophthalmic practice. METHODS Personal experience and a literature review. RESULTS The use of autologous serum, in eye drop form, has been reported as a new treatment for several ocular surfaces diseases. These products have biomechanical and biochemical properties similar to normal tears. They contain components such as fibronectin, vitamin A and growth factors that have an epitheliotrophic effect on the ocular surface epithelial cells. CONCLUSIONS The clinical studies performed showed a variable efficacy, with the preparative process and use of the autologous serum eye drops varying considerably between different studies.
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Rivas L, López-García JS, Murube J, García-Lozano I. Different conjunctival adaptive response in patients with aqueous-deficient and with mucous-deficient dry eyes. Eur J Ophthalmol 2007; 17:160-70. [PMID: 17415687 DOI: 10.1177/112067210701700203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [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: 11/15/2022]
Abstract
PURPOSE To describe the different cellular adaptive patterns found in the conjunctival epithelium from patients with aqueous-deficient and mucous-deficient dry eyes. METHODS The authors studied different conjunctival areas, by impression cytology and by biopsy, 50 eyes with facial nerve paralysis (FNP), 50 eyes with ocular cicatricial pemphigoid (OCP), and 50 eyes from patients with primarily Sjögren syndrome (1SS). RESULTS Eyes with FNP from the first clinical grade showed a progressive alteration of the nonsecretory cells, with a significant decrease in density goblet cells, generally with a PAS-positive staining. Eyes with OCP, during clinical grades 1 and 2, showed a slow deterioration of the nonsecretory cells; but from clinical grade 3, there was a significant increase of the cellular size and the thickness of the conjunctiva. Goblet cells showed a significant decrease in density from clinical grade 1, generally with a PAS-negative staining. Eyes with 1SS during clinical grades 1 and 2 showed a progressive alteration of the nonsecretory cells, with a significant decrease in density goblet cells, and a PAS-positive staining. From clinical grade 3 appeared a significant increase of nonsecretory cellular size and thickness of conjunctiva, with a significant decrease in goblet cell counts, and a PAS-negative staining. CONCLUSIONS Patients with FNP (a primarily aqueous-deficient alteration) follow completely the squamous metaplasia process. Patients with OCP (a primarily mucous-deficient syndrome) have a hypertrophy and hyperplasia process along the ocular surface. Patients with 1SS (a primarily aqueous-deficient and mucin-deficient alteration) have a squamous metaplasia process, but from clinical grade 3 also appears a hypertrophy and hyperplasia process.
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Affiliation(s)
- L Rivas
- Ocular Surface Unit, Research Laboratory, Service of Ophthalmology, University Hospital Ramon y Cajal, Ctra. de Colmenar, km. 9, 28034 Madrid, Spain.
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Torres-Suarez E, Rebolleda G, Munoz Negrete FJ, Cabarga C, Rivas L. Influence of deep scleral flap size on intraocular pressure after deep sclerectomy. Eur J Ophthalmol 2007; 17:350-6. [PMID: 17534815 DOI: 10.1177/112067210701700312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 11/17/2022]
Abstract
PURPOSE To study the effect of several morphometric characteristics of the deep scleral flap on intraocular pressure (IOP) control after deep sclerectomy. METHODS The authors conducted a nonrandomized prospective study of 56 eyes of 51 patients who underwent deep sclerectomy alone or combined with phacoemulsification. A reticulated hyaluronic acid implant was used in all cases. The surface, volume, and weight of the dissected deep scleral flap were measured and recorded. The correlation between these parameters and the postoperative IOP was evaluated at 6 and 12 months postoperatively. RESULTS Forty-nine eyes (87.50%) achieved an IOP of 21 mmHg or less without treatment, and the need for medication was decreased significantly (p<0.001) at 12 months postoperatively. The authors found a significant inverse correlation between the mean postoperative IOP at 6 months and the surface, volume, and weight of the deep scleral flap, but not at 12 months postoperatively. CONCLUSIONS Greater weight, surface area, and volume of the deep scleral flap dissected during deep sclerectomy achieve significantly lower postoperative IOPs in the early postoperative period.
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Affiliation(s)
- E Torres-Suarez
- Glaucoma Unit, Ophthalmology Department, Hospital Ramon y Cajal, University of Alcala, Madrid, Spain
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Rivas L, Dykes GA, Fegan N. A comparative study of biofilm formation by Shiga toxigenic Escherichia coli using epifluorescence microscopy on stainless steel and a microtitre plate method. J Microbiol Methods 2007; 69:44-51. [PMID: 17239460 DOI: 10.1016/j.mimet.2006.11.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [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: 07/31/2006] [Revised: 11/13/2006] [Accepted: 11/22/2006] [Indexed: 11/22/2022]
Abstract
Attachment of Shiga toxigenic Escherichia coli (STEC) to surfaces and the formation of biofilms may enhance persistence in a food processing environment and present a risk of contaminating products. Seven strains of STEC and three non-STEC strains were selected to compare two biofilm quantification methods; epifluorescence microscopy on stainless steel (SS) and a microtitre plate assay. The influence of prior growth in planktonic (nutrient broth) and sessile (nutrient agar) culture on biofilm production, as well as expression of surface structures and the possession of antigen 43 (encoded by agn43) on biofilm formation were also investigated. Biofilms were produced in diluted nutrient broth at 25 degrees C for 24 and 48 h. Curli expression was determined using congo red indicator agar, while the presence of agn43 was determined using polymerase chain reaction. No correlation was found between counts for epifluorescence microscopy on SS and the absorbance values obtained with the microtitre plate method for planktonic and sessile grown cultures. Different abilities of individual STEC strains to attach to SS and microtitre plates were found with some strains attaching better to each surface following growth in either planktonic or sessile culture. All O157 STEC strains had low biofilm counts on SS for planktonic and sessile grown cultures; however, one STEC O157:H- strain (EC516) had significantly greater (p<0.05) biofilm production on microtitre plates compared to the other O157 STEC strains. EC516 and other STEC (O174:H21 and O91:H21) strains expressing curli fimbriae were found to produce significantly greater (p<0.05) biofilms on microtitre plates compared to the non-curli expressing strains. No relationship was found between the production of type-I fimbriae, motility, agn43 and bacterial physicochemical properties (previously determined) and biofilm formation on SS or microtitre plates. Variations between the two biofilm determination methods may suggest that the biofilm production on microtitre plates may not be appropriate to represent other surfaces such as SS and that caution should be taken when selecting a method to quantify biofilm production on a surface.
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Affiliation(s)
- Lucia Rivas
- Food Science Australia, Brisbane, QLD. 4173, Australia
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Rivas L, Fegan N, Dykes GA. Attachment of Shiga toxigenic Escherichia coli to stainless steel. Int J Food Microbiol 2007; 115:89-94. [PMID: 17207875 DOI: 10.1016/j.ijfoodmicro.2006.10.027] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2006] [Revised: 08/14/2006] [Accepted: 10/08/2006] [Indexed: 11/12/2022]
Abstract
Shiga toxigenic Escherichia coli (STEC) are important foodborne pathogens causing gastrointestinal disease worldwide. Bacterial attachment to food surfaces, such as stainless steel may lead to cross contamination of foods and subsequent foodborne disease. A variety of STEC isolates, including E. coli O157:H7/H- strains, were grown in planktonic (broth) and sessile (agar) culture, following which initial attachment to stainless steel was determined using epifluorescence microscopy. Experiments were performed to determine whether the number of bacteria attached to stainless steel differed between STEC strains and between the two modes of growth. No relationship was found between STEC strains and the number of bacteria attached to stainless steel. Five STEC strains, including one non-toxigenic O157 isolate, attached in significantly greater (p<0.05) numbers to stainless steel following growth in planktonic culture compared to sessile culture. In contrast, two clinical strains of O157:H7 attached in significantly greater (p<0.05) numbers following growth in sessile culture compared to planktonic culture. Thirteen out of twenty E. coli strains showed no significant difference (p>0.05) in attachment when grown in planktonic or sessile culture. The change of interfacial free energy between the bacterial strains and stainless steel was calculated and the influence of free energy in attachment was determined. Although a significant variation (p<0.05) in free energy values was found between STEC strains, no correlation was found between free energy values and bacterial counts on stainless steel. In addition, no correlation was also found between bacterial hydrophobicity and surface charge values or production of surface structures (type I fimbriae or flagella) (previously determined) with the number of bacteria attached to stainless steel. The results of this study suggest that different growth conditions (planktonic and sessile) can influence the attachment of STEC to stainless steel. Factors other than bacterial physicochemical properties and these surface structures may also influence STEC attachment to stainless steel.
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Affiliation(s)
- Lucia Rivas
- Food Science Australia, Brisbane, QLD. 4173, Australia
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Abstract
OBJECTIVE To attempt to review the aniridia keratopathy pathogenesis and establish a treatment protocol according to the severity of the symptoms. METHODS Personal experience in aniridic keratopathy management and a bibliography review. RESULTS The ocular manifestations of this anomaly include defects of the cornea, glaucoma, lens subluxation, cataracts, hypoplasia of the iris, fovea and optic nerve, amblyopia and nystagmus. The keratopathy occurs in a 20% of patients with aniridia. The correct PAX6 expression is necessary for normal corneal development, limbal stem cell activity and correct corneal epithelial cell migration and adhesion. CONCLUSIONS The management of ocular surface diseases due to limbal stem cell deficiency in aniridia is complex but has changed in recent years, as an understanding of the limbal stem cells and their microenvironment has modified the therapeutic approach. The use of autologous serum eye drops, amniotic membrane transplantation, limbal transplantation or cultivated limbal cell transplantation have all been reported as a treatment for several ocular surface diseases.
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Rivas L. [Low use of laboratory tests in the diagnosis of the ocular surface]. Arch Soc Esp Oftalmol 2006; 81:499-500. [PMID: 17016781 DOI: 10.4321/s0365-66912006000900002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
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Abstract
PURPOSE To compare corneal surface evolution after moderate alkaline burns by impression cytology in patients treated with medical therapy or with amniotic membrane transplantation (AMT). METHODS A prospective study of 24 eyes from 18 patients (13 men and 5 women) with moderate alkaline burns was performed. All patients were divided according to the clinical ocular severity and the therapy used. Twelve eyes were treated surgically with AMT and the other 12 eyes received only medical therapy. Corneal cytology was obtained immediately after the burns, and 1, 2, 5, and 9 months later. We differentiated between samples obtained from affected areas and areas not affected by the burns. Cellular size, nuclear size, and nuclear-cytoplasmic (N:C) ratio were examined in corneal epithelial cells, as was the presence of goblet cells in corneal epithelium. RESULTS Nuclear size, cellular size, and N:C ratio in non-burn-affected corneal areas had no significant alterations in comparison with normal eyes. In contrast, in burn-affected corneal areas, these parameters were significantly worse, and the presence of goblet cells in corneal epithelium was frequent 1 month after severe burns. Cellular size, nuclear size, N:C ratio, and corneal conjunctivalization improved during the study in all patients, but corneal reepithelialization occurred earlier in patients treated with AMT than in patients with only medical therapy. CONCLUSION Morphologic and morphometric analysis of corneal cells by impression cytology after ocular burns permits the establishment of cellular reepithelialization patterns in relation with limbal deficiency level and with clinical ocular severity. AMT improves corneal reepithelialization earlier than medical therapy in moderate alkaline burns.
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Abstract
Shiga toxigenic Escherichia coli (STEC) serotypes are important foodborne pathogens that cause gastrointestinal disease worldwide. An understanding of how STEC strains attach to surfaces may provide insight into the potential persistence of and contamination with STEC in food environments. The initial attachment of a selection of STEC serotypes to beef muscle and adipose tissue was evaluated for isolates grown in planktonic and sessile culture. Initial experiments were performed to determine whether attachment differed among STEC strains and between the two modes of growth. Viable counts were obtained for loosely and strongly attached cells, and the strength of attachment (Sr) was calculated. All bacterial isolates grown in sessile culture attached in higher numbers to muscle and adipose tissue than did bacteria in planktonic cultures. For all attachment assays performed, mean concentrations for loosely attached cells were consistently higher than concentrations for strongly attached cells. The mean concentrations for strongly attached bacteria for planktonic and sessile cultures were significantly higher (P < 0.05) on adipose than on muscle tissue. However, some strains of STEC, particularly those from sessile culture, did not differ in their attachment to muscle or adipose tissue. Sr values were not significantly different (P > 0.05) among STEC isolates for all assays. No correlation was found between bacterial hydrophobicity and surface charge values (previously determined) and production of surface structures, viable counts, and Sr values. STEC grown in planktonic and sessile culture seems to behave differently with respect to attachment to muscle and adipose tissue. Cells in sessile culture may have a greater potential to strongly attach to meat surfaces.
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Affiliation(s)
- Lucia Rivas
- Food Science Australia, Brisbane, Queensland 4173, Australia.
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López-García JS, Rivas L, García-Lozano I. [Corneal epithelium squamous metaplasia determination as diagnostic factor in limbal deficiency]. Arch Soc Esp Oftalmol 2006; 81:281-8. [PMID: 16752320 DOI: 10.4321/s0365-66912006000500007] [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] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
PURPOSE To determine the correlation between the squamous metaplasia grade of the corneal surface and the clinical severity of the limbal deficiency in patients with this disorder. METHODS We studied 98 eyes of patients with limbal deficiency by impression cytology. These patients were divided into four groups in relation to their clinical severity: 14 eyes had no symptoms, 34 eyes showed a mild grade of limbal deficiency, 28 eyes had a moderate grade and 22 eyes had severe limbal deficiency. Corneal cytology was performed in each patient. Cellular size, nuclear size, nuclear changes and the nuclear-cytoplasmic (N:C) ratio were defined in corneal epithelial cells, in addition to evaluation for the presence of goblet cells in the corneal epithelium. RESULTS In patients with limbal deficiency without symptoms, we found that the cellular size was 477 (SD140) microm2 and the N:C ratio was 1:5.25 (SD1.5). In patients with mild limbal deficiency, the cellular size was 764 (SD122.6) microm2 and the N:C ratio was 1:8.2 (SD1.4). These patients did not show corneal conjunctivalization. In patients with moderate limbal deficiency the cellular size was 1,162 (SD340.2) microm2 and the N:C ratio was 1:13.2 (SD3.6). Some patients showed corneal conjunctivalization that was defined by the presence of goblet cells in the corneal epithelium. In patients with severe limbal deficiency, the cellular size was 2,036 (SD382) microm2 and the N:C ratio was 1:23.6 (SD4.0). Corneal conjunctivalization was present in all of these patients. CONCLUSIONS There was a correlation between limbal deficiency severity and squamous metaplasia grade defined by impression cytology. Impression cytology was very useful for the diagnosis of cases of mild or subclinical limbal deficiency.
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Affiliation(s)
- J S López-García
- Servicio de Oftalmología, Hospital Central de Cruz Roja, Madrid, España.
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Abstract
AIMS To investigate the physicochemical surface properties, such as cellular surface charge, hydrophobicity and electron donor/acceptor potential of a selection of Shiga toxigenic Escherichia coli (STEC) isolates grown in broth and agar culture. METHODS AND RESULTS Cellular surface charge was determined using zeta potential measurements. Hydrophobicity of the isolates was determined using bacterial adhesion to hydrocarbons assay, hydrophobic interaction chromatography and contact angle measurements. Microbial adhesion to solvents was used to determine the electron donor/acceptor characteristics. No differences of surface charge measurements were found between broth and agar grown cultures. Isolates belonging to serogroup O157 and serotypes O26:H11 and O111:H- were significantly (P < 0.05) less negatively charged than other STEC serotypes tested. All strains were hydrophilic with most methods and demonstrated a lower hydrophobicity in agar culture compared with broth culture. All strains demonstrated a strong microbial adhesion to chloroform indicating that STEC possess an electron donor and basic character. A relationship between serogroup O157 and other STEC serotypes was apparent using principal-component analysis (PCA). CONCLUSIONS Combining the results for physicochemical properties using PCA differentiated between strains belonging to the O157 serogroup and other STEC/non-STEC strains. PCA found similar results for broth and agar grown cultures. SIGNIFICANCE AND IMPACT OF THE STUDY Particular serotypes of STEC possess similar physicochemical properties which may play a role in their pathogenicity or potential attachment to various surfaces.
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Affiliation(s)
- L Rivas
- Food Science Australia, Brisbane, Queensland, Australia.
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López-García JS, Rivas L, García-Lozano I. [Moderate limbal deficiency in patients with congenital aniridia treated with amniotic membrane transplantation]. ACTA ACUST UNITED AC 2005; 80:517-23. [PMID: 16193434 DOI: 10.4321/s0365-66912005000900005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [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: 11/11/2022]
Abstract
PURPOSE To study the ocular surface evolution by impression cytology and limbal biopsy in patients with congenital aniridia treated with amniotic membrane transplantation (AMT). METHODS We studied 14 eyes of patients with congenital aniridia and moderate limbal deficiency that were treated with AMT. The morphology of the limbocorneal epithelium and stroma was examined by impression cytology and limbal biopsy. Impression cytology was performed prior to surgery and 3, 6, 9, 12 and 24 months after treatment. Limbal biopsy was performed before surgery and 9 months after AMT. RESULTS Visual acuity showed a mean improvement of 0.3 at 24 months of follow-up. Corneal reepithelialization was completed by 2 months in all patients, however, after 9 months some patients showed persistent epithelial defects and chronic ulceration. Corneal clarity and peripheral neovascularization was markedly improved after 2 months. Impression cytology showed an improvement in squamous metaplasia at 3 and 6 months, however after nine months, until as late as 24 months, a progressive worsening was seen in epithelial cell metaplasia then being similar in extent to that before surgery. Limbal biopsy nine months after surgery showed a nearly normal epithelium and limbocorneal stroma. CONCLUSIONS AMT is a very effective procedure, although its effect is transitory, for restoring the ocular surface integrity in patients with congenital aniridia and moderate limbal deficiency.
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Abstract
PURPOSE To study the ocular surface evolution in patients with severe limbal deficiency treated with limbal allograft transplantation (LT) combined with amniotic membrane transplantation (AMT). METHODS We studied 14 eyes with severe limbal deficiency, treated with LT combined with AMT (LT + AMT). We studied the morphology of the limbocorneal epithelium and stroma by impression cytology and limbal biopsy. RESULTS Visual acuity showed a mean improvement of 0.4 at 24 months of follow-up. Corneal clarity and loss of neovascularization were markedly improved after 3 and 6 months, respectively. We did not find corneal conjuntivalization on cytology performed 6 months after surgery, except in a patient with chemical burn. Cytology and limbal biopsy performed nine months after surgery showed an epithelium and limbocorneal stroma near to normality. Squamous metaplasia was worse in patients with Stevens-Johnson syndrome and ocular cicatricial pemphigoid after 12 months, but was similar in patients with chemical burns and improved in patients with aniridia. CONCLUSIONS LT + AMT is a very effective procedure for restoring the ocular surface integrity in patients with severe limbal deficiency. This combination improves the outcomes obtained with LT alone.
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Alberola J, Rodríguez A, Francino O, Roura X, Rivas L, Andreu D. Safety and efficacy of antimicrobial peptides against naturally acquired leishmaniasis. Antimicrob Agents Chemother 2004; 48:641-3. [PMID: 14742227 PMCID: PMC321547 DOI: 10.1128/aac.48.2.641-643.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [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: 11/20/2022] Open
Abstract
Leishmaniases, which are important causes of morbidity and mortality in humans and dogs, are extremely difficult to treat. Antimicrobial peptides are rarely used as alternative treatments for naturally acquired parasitic diseases. Here we report that the acylated synthetic antimicrobial peptide Oct-CA(1-7)M(2-9) is safe and effective for treating naturally acquired canine leishmaniasis.
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Affiliation(s)
- J Alberola
- Departament de Farmacologia, Terapèutica i Toxicologia, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Rivas L, Murube J, Rivas A, Shalaby O. [The contribution of impression cytology towards the diagnosis of cicatricial ocular pemphigoid in its primary stages]. Arch Soc Esp Oftalmol 2004; 79:67-74. [PMID: 14988785 DOI: 10.4321/s0365-66912004000200006] [Citation(s) in RCA: 5] [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] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
PURPOSE To study the conjunctival epithelium by means of impression cytology in the cicatricial ocular pemphigoid (COP) in search of a possible relation between the degree of squamous metaplasia and clinical severity of the disease, in order to facilitate the earliest possible diagnosis. METHODS Impression cytology specimens were collected from 20 patients with varying degrees of active COP. A clinical ophthalmologic examination was performed by biomicroscopy, impression cytology, conjunctival biopsy, study of direct (IFd) and of indirect immunofluorescence (IFi). RESULTS Patients with COP grade I had a normal distribution of non-secretory epithelial cells with a decrease in goblet cell density of around 85% compared to control and mucin content was decrease. Patients with grade II showed a slight degree of squamous metaplasia. Goblet cell density decreased by around 95% and mucin content was scarce. Patients with clinical grade III had a moderate degree of squamous metaplasia in non-secretory cells whilst goblet cell density decreased by around 99%; mucin content was almost zero. Patients with clinical grade IV showed a moderate to severe degree of squamous metaplasia in non-secretory cells; there was a total absence of goblet cells. CONCLUSIONS Conjunctival impression cytology in COP showed a significant decrease in goblet cells from the early stages of disease without significant alterations in non-secretory epithelial cells. In patients with negative IFd impression cytology could enable the identification of a possible COP.
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Affiliation(s)
- L Rivas
- Servicio de Oftalmología, Hospital Universitario Ramón y Cajal, Madrid, Spain
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Rivas L, Fegan N, Vanderlinde P. Isolation and characterisation of Arcobacter butzleri from meat. Int J Food Microbiol 2004; 91:31-41. [PMID: 14967558 DOI: 10.1016/s0168-1605(03)00328-3] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [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: 12/20/2002] [Revised: 05/23/2003] [Accepted: 05/30/2003] [Indexed: 11/16/2022]
Abstract
A survey was conducted to determine the prevalence of Arcobacter in ground chicken, pork, beef and lamb meats. Meat samples were enriched in Arcobacter broth (AB) containing cefoperazone, amphotericin and teicoplanin (CAT) supplement. Samples were screened for the presence of Arcobacter spp. using a multiplex polymerase chain reaction (PCR) followed by isolation on blood and selective agar. Arcobacter butzleri was the only species of Arcobacter isolated from 35% of 88 samples of ground meats. A. butzleri was more frequently isolated from poultry (73%) than pork (29%), beef (22%) or lamb (15%) samples. No significant differences were found in the isolation rates and from the different regions sampled. Isolates were characterised by pulsed-field gel electrophoresis (PFGE) using SacII, EagI and SmaI restriction endonucleases. A number of isolates with indistinguishable PFGE fingerprints were found to be epidemiologically related, which may indicate cross-contamination of common types of Arcobacter from different meat species or between meat species. The public health significance of Arcobacter in ground meat needs to be determined.
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Affiliation(s)
- Lucia Rivas
- Food Science Australia, Food Safety and Quality, PO Box 3312, Tingalpa DC, CANNON HILL, QLD, 4173, Australia.
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Rivas L, Murube J, Rivas A, Murube E. [Impression cytology study of dry eyes in patients with congenital aniridia]. Arch Soc Esp Oftalmol 2003; 78:615-22. [PMID: 14648368] [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: 04/27/2023]
Abstract
PURPOSE To evaluate the long-term results of ocular surface reconstruction by means of medical treatment, limbal transplantation or amniotic membrane transplantation in patients with congenital aniridia. MATERIAL AND METHODS Thirty-six eyes from 18 consecutive patients with aniridia were studied by clinical tests (Schirmer test, break-up time and vital rose bengal staining) and impression cytology. Thirteen patients were treated with lubricant drops for ocular dryness. Two eyes from 2 patients also received limbal transplantation, and other 4 eyes underwent amniotic membrane transplantation. RESULTS Corneal and conjunctival epithelium improved in all patients treated with lubricant drops. Ocular surface epithelium condition was worse in those patients not receiving artificial tears. After 12 months of limbal transplantation, clinical and morphological results showed a significant corneal recovery of at least two grades of squamous metaplasia in comparison with the previous situation. We also carried out amniotic membrane transplantation in patients with aniridia. The improvement was initially observed after 2 months and by the sixth month there was a significant improvement in clinical signs and symptoms, with normal corneal cells next to altered ones. CONCLUSIONS All the aniridic patients showed dry eye. Treatment with lubricant drops is necessary to decrease the squamous metaplasia process. Limbal transplantation and amniotic membrane implantation are needed for effective corneal surface reconstruction in patients with aniridia, which is followed by a significant improvement of the dry eye.
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Affiliation(s)
- L Rivas
- Servicio de Oftalmología, Hospital Universitario Ramón y Cajal, Madrid, Spain
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Rivas L, López García JS. [Lacunar folds and dry eye]. Arch Soc Esp Oftalmol 2003; 78:297; author reply 297-8. [PMID: 12838461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
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Murube J, Rivas L. Biopsy of the conjunctiva in dry eye patients establishes a correlation between squamous metaplasia and dry eye clinical severity. Eur J Ophthalmol 2003; 13:246-56. [PMID: 12747645 DOI: 10.1177/112067210301300302] [Citation(s) in RCA: 31] [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: 11/16/2022]
Abstract
PURPOSE The aim of this work was to evaluate the different grades of squamous metaplasia of the conjunctiva during the clinical course of dry eye syndrome, detecting the most characteristic morphological and morphometric changes by biopsy in order to provide a diagnostic classification. METHODS The conjunctiva was studied under light microscopy by conventional histological methods and by morphometric analysis in 165 patients and in 33 controls. Patients were classified according to the Schirmer 1 test, break-up time, rose Bengal staining, osmolarity and impression cytology. The epithelium and connective tissue, with their different cells and other structures, were studied. RESULTS The conjunctiva in dry eye patients showed progressive stratification, hyperplasia, hypertrophy and cellular flattening, with loss of goblet cell density and mucous layer. We found five pathological grades of squamous metaplasia and one normal grade. Clear nuclear alterations (indentation and binucleation) were found in the early grades of dry eye syndrome, but pyknotic nuclei and anucleated cells were only seen in the most severe grades. The smallest epithelial cells were found in the control group and their size increased with the severity of the dry eye syndrome. From the earliest stages to the most severe cases, increases in cellular separation were observed. There was also an increase in the number of inflammatory cells. Blood and lymphatic vessels showed alterations only in the most severe cases. CONCLUSIONS This is the first grading system proposed for biopsy evaluation of the ocular surface in dry eye patients. These morphological and morphometric studies alone were able, even in the earliest phases of dry eye, to detect the squamous metaplasia that progresses from the surface of the epithelium to the connective tissue. This degenerative or adaptative cellular process was characterized mainly by marked increases in the stratification, epithelial cellular size and a general loss of goblet cells.
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Affiliation(s)
- J Murube
- School of Medicine, Alcalá de Henares University, Madrid, Spain
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