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Fernando VAK, Weerasena J, Lakraj GP, Perera IC, Dangalle CD, Handunnetti S, Premawansa S, Wijesinghe MR. Lethal and sub-lethal effects on the Asian common toad Duttaphrynus melanostictus from exposure to hexavalent chromium. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 177:98-105. [PMID: 27262939 DOI: 10.1016/j.aquatox.2016.05.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/16/2016] [Accepted: 05/21/2016] [Indexed: 06/05/2023]
Abstract
Chromium discharged in industrial effluents frequently occurs as an environmental pollutant, but the lethal and sub-lethal effects the heavy metal might cause in animals exposed to it have been insufficiently investigated. Selecting the amphibian Duttaphrynus melanostictus, we carried out laboratory tests to investigate the effects of short and long term exposure to hexavalent chromium (Cr(VI)) in both tadpoles and adult toads. The concentrations used were 0.002, 0.02, 0.2, 1.0 and 2.0mg/L, the first three corresponding to field levels. In vitro exposures were also carried out using toad erythrocytes and Cr(VI) concentrations of 0.0015, 0.003, 0.015, 0.03, 0.15mg/L. Mortality, growth retardation, developmental delays and structural aberrations were noted in the metal-treated tadpoles, with increasing incidence corresponding to increase in Cr(VI) level and duration of exposure. Many of the sub-lethal effects were evident with long term exposure to environmentally relevant levels of the toxicant. Changes in selected blood parameters and erythrocyte morphometry were also detected in Cr(VI) exposed toads, indicating anaemic and leucopenic conditions. In the genotoxicity study, DNA damage indicated by comet assay and increased micronuclei frequency, occurred at the low Cr(VI) concentrations tested. The multiple deleterious effects of exposure to chromium signal the need for monitoring and controlling the discharge of chromium to the environment. The dose-dependency and genotoxic effects observed in this widely distributed Asian toad indicates its suitability for monitoring heavy metal pollution in aquatic systems.
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Affiliation(s)
- Vindhya A K Fernando
- Department of Zoology and Environment Sciences, University of Colombo, Colombo 03, Sri Lanka.
| | - Jagathpriya Weerasena
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo 03, Sri Lanka.
| | - G Pemantha Lakraj
- Department of Statistics, University of Colombo, Colombo 03, Sri Lanka.
| | - Inoka C Perera
- Department of Zoology and Environment Sciences, University of Colombo, Colombo 03, Sri Lanka.
| | - Chandima D Dangalle
- Department of Zoology and Environment Sciences, University of Colombo, Colombo 03, Sri Lanka.
| | - Shiroma Handunnetti
- Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo, Colombo 03, Sri Lanka.
| | - Sunil Premawansa
- Department of Zoology and Environment Sciences, University of Colombo, Colombo 03, Sri Lanka.
| | - Mayuri R Wijesinghe
- Department of Zoology and Environment Sciences, University of Colombo, Colombo 03, Sri Lanka.
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Hoelzle LE, Zeder M, Felder KM, Hoelzle K. Pathobiology of Mycoplasma suis. Vet J 2014; 202:20-5. [PMID: 25128978 DOI: 10.1016/j.tvjl.2014.07.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 07/20/2014] [Accepted: 07/26/2014] [Indexed: 01/25/2023]
Abstract
Mycoplasma suis is an uncultivable bacterium lacking a cell wall that attaches to and may invade the red blood cells of pigs. M. suis infections occur worldwide and cause the pig industry serious economic losses due to the disease known as infectious anaemia of pigs or, historically, porcine eperythrozoonosis. Infectious anaemia of pigs is characterised predominantly by acute haemolytic or chronic anaemia, along with non-specific manifestations, such as growth retardation in feeder pigs and poor reproductive performance in sows. The fastidious nature of M. suis, as well as the lack of an in vitro cultivation system, has hampered the understanding of the biology and pathogenicity of this organism. Pathogenetic mechanisms of M. suis include direct destruction of red blood cells by adhesion, invasion, nutrient scavenging, immune-mediated lysis and eryptosis, as well as endothelial targeting. Recently published genome sequences, in combination with proteome analyses, have generated new insights into the pathogenicity of M. suis. The present review combines these data with the knowledge provided by experimental M. suis infections.
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Affiliation(s)
- Ludwig E Hoelzle
- Institute of Environmental and Animal Hygiene (with Animal Clinic), University of Hohenheim, Stuttgart, Germany.
| | | | | | - Katharina Hoelzle
- Institute of Animal Nutrition, University of Hohenheim, Stuttgart, Germany
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Nanotransformation of the haemotrophic Mycoplasma suis during in vitro cultivation attempts using modified cell free Mycoplasma media. Vet Microbiol 2012; 160:227-32. [PMID: 22682998 DOI: 10.1016/j.vetmic.2012.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 05/12/2012] [Accepted: 05/16/2012] [Indexed: 11/20/2022]
Abstract
Mycoplasma suis belongs to haemotrophic mycoplasmas (HMs) which cause infectious anaemia in a large variety of mammals. To date, no in vitro cultivation system for M. suis or other HMs has been established. We hypothesised that M. suis could grow in classical Mycoplasma media supplemented with nutrients (e.g. glucose, iron-binding proteins) which are naturally available from its host environment, the porcine blood. Blood from experimentally M. suis-infected pigs was used to inoculate either standard SP-4 Mycoplasma medium supplemented with iron-binding proteins (transferrin, haemin, and haemoglobin) or glucose-enriched Hayflick Mycoplasma medium. A quantitative M. suis-specific real-time PCR assay was applied to determine and quantify M. suis loads weekly during 12 week-incubation. The first 2 weeks after inoculation M. suis loads decreased remarkably and then persisted at a stationary level over the observation time of 12 weeks in iron-binding protein- or glucose supplemented media variants. Scanning electron microscopic analysis of liquid M. suis sub-cultures on Hayflick agar showed small, densely-packed microcolonies of irregular M. suis cells of reduced size (0.2-0.6μm) indicating nanotransformation. The partial 16S rDNA sequence of these cultured M. suis nanocells was 99.9% identical to M. suis. M. suis cells derived from liquid cultures interact in vitro with porcine erythrocytes by fibril-like structures. We conclude, that the modified Mycoplasma media used for M. suis cultivation are obviously unfavourable for growth but lead to culture persistence. M. suis adapt to inappropriate culture conditions by alteration into nanoforms.
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Hoelzle K, Peter S, Sidler M, Kramer MM, Wittenbrink MM, Felder KM, Hoelzle LE. Inorganic pyrophosphatase in uncultivable hemotrophic mycoplasmas: identification and properties of the enzyme from Mycoplasma suis. BMC Microbiol 2010; 10:194. [PMID: 20646294 PMCID: PMC2916918 DOI: 10.1186/1471-2180-10-194] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 07/20/2010] [Indexed: 11/10/2022] Open
Abstract
Background Mycoplasma suis belongs to a group of highly specialized hemotrophic bacteria that attach to the surface of host erythrocytes. Hemotrophic mycoplasmas are uncultivable and the genomes are not sequenced so far. Therefore, there is a need for the clarification of essential metabolic pathways which could be crucial barriers for the establishment of an in vitro cultivation system for these veterinary significant bacteria. Inorganic pyrophosphatases (PPase) are important enzymes that catalyze the hydrolysis of inorganic pyrophosphate PPi to inorganic phosphate Pi. PPases are essential and ubiquitous metal-dependent enzymes providing a thermodynamic pull for many biosynthetic reactions. Here, we describe the identification, recombinant production and characterization of the soluble (s)PPase of Mycoplasma suis. Results Screening of genomic M. suis libraries was used to identify a gene encoding the M. suis inorganic pyrophosphatase (sPPase). The M. suis sPPase consists of 164 amino acids with a molecular mass of 20 kDa. The highest identity of 63.7% was found to the M. penetrans sPPase. The typical 13 active site residues as well as the cation binding signature could be also identified in the M. suis sPPase. The activity of the M. suis enzyme was strongly dependent on Mg2+ and significantly lower in the presence of Mn2+ and Zn2+. Addition of Ca2+ and EDTA inhibited the M. suis sPPase activity. These characteristics confirmed the affiliation of the M. suis PPase to family I soluble PPases. The highest activity was determined at pH 9.0. In M. suis the sPPase builds tetramers of 80 kDa which were detected by convalescent sera from experimentally M. suis infected pigs. Conclusion The identification and characterization of the sPPase of M. suis is an additional step towards the clarification of the metabolism of hemotrophic mycoplasmas and, thus, important for the establishment of an in vitro cultivation system. As an antigenic and conserved protein the M. suis sPPase could in future be further analyzed as a diagnostic antigen.
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Affiliation(s)
- Katharina Hoelzle
- Institute of Veterinary Bacteriology, University Zurich, Zurich, Switzerland.
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Tasker S, Peters IR, Papasouliotis K, Cue SM, Willi B, Hofmann-Lehmann R, Gruffydd-Jones TJ, Knowles TG, Day MJ, Helps CR. Description of outcomes of experimental infection with feline haemoplasmas: copy numbers, haematology, Coombs' testing and blood glucose concentrations. Vet Microbiol 2009; 139:323-32. [PMID: 19615832 PMCID: PMC2771275 DOI: 10.1016/j.vetmic.2009.06.028] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2008] [Revised: 06/10/2009] [Accepted: 06/15/2009] [Indexed: 11/26/2022]
Abstract
The aim of this study was to compare blood copy, haematological and glucose values between cats experimentally infected with either Mycoplasma haemofelis (Group HF: 10 cats), 'Candidatus M. haemominutum' (Group HM: 3 cats) or 'Candidatus M. turicensis' (Group TU: 3 cats). Blood samples were collected regularly up to 85 days post-infection (DPI) for haemoplasma real-time quantitative PCR, haematology, Coombs' testing and blood glucose measurement. Statistical analysis was performed using a general linear model (ANOVA) appropriate for a repeated measures experiment with significance set as P<0.05. Cats in Group TU had significantly lower blood copy numbers than cats in Group HF (P<0.001) and HM (P<0.001). All Group HF cats developed anaemia (often severe), macrocytosis and evidence of erythrocyte-bound antibodies whereas Groups HM and TU cats did not. Group HF had significantly lower PCVs, haemoglobin concentrations and red blood cell counts, and significantly higher mean cell volumes, than Groups HM and TU. In Group HF, erythrocyte-bound antibodies reactive at 4 degrees C (both IgM and IgG) appeared between 8 and 22 DPI and persisted for two to four weeks, whereas those reactive at 37 degrees C (primarily IgG) appeared between 22 and 29 DPI and persisted for one to five weeks. In most cats antibodies appeared after the fall in haemoglobin started. Although Group TU had significantly lower glucose concentrations than Groups HF (P=0.006) and HM (P=0.027), mean blood glucose concentrations remained within the reference range in all groups. This study demonstrates that M. haemofelis infection, in contrast to 'Candidatus M. haemominutum' and 'Candidatus M. turicensis' infection, can result in a severe macrocytic anaemia and the development of cold and warm reactive erythrocyte-bound antibodies.
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Affiliation(s)
- Séverine Tasker
- School of Clinical Veterinary Science, University of Bristol, Langford, Bristol BS40 5DU, United Kingdom.
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Lascola K, Vandis M, Bain P, Bedenice D. Concurrent Infection withAnaplasma phagocytophilumandMycoplasma haemolamaein a Young Alpaca. J Vet Intern Med 2009; 23:379-82. [DOI: 10.1111/j.1939-1676.2008.0268.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Li W, Du N, Xu B, Dong W, Qu Z, Wang Y, Sui Y. Alteration of integrin-associated protein (CD47) on experimental porcine eperythrozoonosis. Vet Res Commun 2008; 32:411-8. [PMID: 18297407 DOI: 10.1007/s11259-008-9038-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2007] [Accepted: 01/14/2008] [Indexed: 11/29/2022]
Abstract
To evaluate the alteration of CD47 on RBCs of pigs infected with M. suis, we induced the experimental porcine eperythrozoonosis and collected the blood samples at the different time points. The result of analysis by flow cytometry after reaction with mouse-anti-human CD47 and caprine-anti-mouse IgG-FITC reagents indicated that the CD47 quantity on RBCs changed correlatively with the course of PE. The lowest value of M1 (percentage of the positive cells in fluorescence intensity) occurred on day 7 post inoculation at the peak of parasitemia and decreased 82% compared with the control sample. And then, the values of M1 on day 14 and 21 rised slowly but were still significantly different with the controls (p < 0.01). These suggested that the quantity of CD47 on RBCs altered progressively with the phases of the PE disease. The decrease of CD47 on RBCs maybe weaken the inhibitory CD47-SIRPalpha interaction and provide positive signals for phagocytosis of macrophages resulting in the removal of the RBCs from the circulation. In conclusion, CD47, a marker on RBCs, maybe play an important role on the mechanism of hemolysis caused by infection of M. suis.
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Affiliation(s)
- Wei Li
- College of Veterinary Medicine, China Agricultural University, Haidian District, Beijing 100094, China
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Hoelzle LE. Haemotrophic mycoplasmas: recent advances in Mycoplasma suis. Vet Microbiol 2008; 130:215-26. [PMID: 18358641 DOI: 10.1016/j.vetmic.2007.12.023] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Revised: 12/07/2007] [Accepted: 12/11/2007] [Indexed: 10/22/2022]
Abstract
Haemotrophic mycoplasmas (haemoplasmas) are uncultivable, small epicellular, cell wall less, tetracycline-sensitive bacteria that attach to the surface of host erythrocytes. Today, haemotrophic mycoplasmas are found in a large number of animals, with Mycoplasma suis being the porcine pathogen. Haemoplasmas can cause infections which are clinically marked, either by an overt life-threatening haemolytic anaemia or a mild chronic anaemia, by illthrift, infertility, and immune suppression. The life cycle of haemoplasmas on the surface of nucleus-less red blood cells is unique for mycoplasma and therefore, it is evident that these haemotrophic pathogens must have features that allow them to colonise and replicate on red blood cells. However, the mechanisms of adhesion and replication of M. suis on erythrocytes, for instance, as well as the significance of metabolic interchanges between the agent and the target cells, are completely unknown to date. Far from having gained clear insight into the clinical significance of the haemoplasmas, our knowledge about the physiology, genetics, and host-pathogen interaction of this novel group of bacteria within the Mollicutes order is rather limited. This can be explained primarily by the unculturability of these bacteria. The enormous advances in molecular biology witnessed in recent years have had a major impact on several areas of biological sciences, i.e. the fields of modern medical bacteriology and infectious diseases. This review describes progress made in research of the pathobiology of M. suis these past few years.
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Affiliation(s)
- L E Hoelzle
- Institute of Veterinary Bacteriology, University of Zurich, Winterthurerstrasse 270, Zurich, Switzerland.
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Hoelzle LE, Hoelzle K, Helbling M, Aupperle H, Schoon HA, Ritzmann M, Heinritzi K, Felder KM, Wittenbrink MM. MSG1, a surface-localised protein of Mycoplasma suis is involved in the adhesion to erythrocytes. Microbes Infect 2007; 9:466-74. [PMID: 17336568 DOI: 10.1016/j.micinf.2007.01.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 12/21/2006] [Accepted: 01/10/2007] [Indexed: 10/23/2022]
Abstract
Mycoplasma suis is a member of the group of uncultivable haemoplasmas which colonise erythrocytes of a wide range of vertebrates. Adhesion to erythrocytes is the crucial step in the unique haemoplasma life cycle. Due to the lack of a cultivation system, no adhesion structures have been identified so far. In order to determine potential adhesion molecules of M. suis, we screened genomic M. suis libraries. The protein MSG1 with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) similarity was identified. The encoding gene msg1 is 1011bp in size. The overall homology of the deduced amino acid sequence to GAPDHs of other pathogenic mycoplasmas ranged from 52.6% to 54.5%. Recombinant MSG1 expressed in Escherichia coli exhibited GAPDH activity. Immunoblot and immunoelectron microscopy analyses using antibodies against rMSG1 verified the membrane and surface localisation of native MSG1 in M. suis. Furthermore, we showed that rMSG1 binds to erythrocyte lysate in a dose-dependent manner. E. coli transformants which express MSG1 on their surface acquire the ability to adhere to porcine erythrocytes. This adhesion could be specifically and significantly inhibited by rMSG1 and antibodies to MSG1. In conclusion, our studies indicate that the membrane-associated MSG1 represents the first putative adhesion protein identified in the group of haemoplasmas.
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Affiliation(s)
- Ludwig E Hoelzle
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 270, 8057 Zurich, Switzerland.
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Hoelzle LE, Hoelzle K, Ritzmann M, Heinritzi K, Wittenbrink MM. Mycoplasma suis antigens recognized during humoral immune response in experimentally infected pigs. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 13:116-22. [PMID: 16426008 PMCID: PMC1356629 DOI: 10.1128/cvi.13.1.116-122.2006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Today, serodiagnostic tests for Mycoplasma suis infections in pigs have low accuracies. The development of novel serodiagnostic strategies requires a detailed analysis of the humoral immune response elicited by M. suis and, in particular, the identification of antigenic proteins of the agent. For this study, indirect enzyme-linked immunosorbent assay (ELISA) and immunoblot analyses were performed using pre- and sequential postinoculation sera from M. suis-infected and mock-infected control pigs. M. suis purified from porcine blood served as the antigen. Eight M. suis-specific antigens (p33, p40, p45, p57, p61, p70, p73, and p83) were identified as targets of the immunoglobulin G (IgG) antibody response during experimental infection, with p40, p45, and p70 being the preferentially recognized M. suis antigens. Besides the M. suis-specific antigens, porcine immunoglobulins were identified in blood-derived M. suis preparations. By immunoglobulin depletion, the specificity of the M. suis antigen for use in indirect ELISA was significantly improved. M. suis-specific Western blot and ELISA reactions were observed in all infected pigs by 14 days postinfection at the latest and until week 14, the end of the experiments. During acute clinical attacks of eperythrozoonosis, a derailment of the antibody response, determined by decreases in both the M. suis net ELISA values and the numbers of M. suis-specific immunoblot bands, was accompanied by peaking levels of autoreactive IgG antibodies. In conclusion, the M. suis-specific antigens found to stimulate specific IgG antibodies are potentially useful for the development of novel serodiagnostic tests.
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Affiliation(s)
- L E Hoelzle
- Institute of Veterinary Bacteriology, University of Zurich, Winterthurerstrasse 270, 8057 Zurich, Switzerland.
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Burkhard MJ, Garry F. Artifactual hypoglycemia associated with hemotrophic mycoplasma infection in a lamb. Vet Clin Pathol 2004; 33:244-8. [PMID: 15570563 DOI: 10.1111/j.1939-165x.2004.tb00381.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND A 35-day-old male lamb with Mycoplasma ovis infection (previously Eperythrozoon ovis) was evaluated because of severe hypoglycemia (serum glucose 4 mg/dL, Hitachi 704 automated chemistry analyzer) inconsistent with the animal's condition. Whole blood glucose concentration measured with a glucometer was 74 mg/dL. OBJECTIVE The purpose of this study was to investigate this discrepancy through in vitro evaluation of the patient's blood. METHODS Blood was incubated alone, with increasing concentrations of plasma, or with equine serum of known glucose concentration for 0, 15, 30, and 60 minutes at room temperature; end-point glucose concentrations were compared with blood from a control sheep handled similarly. RESULTS A rapid decline in glucose concentration was observed in heparinized or EDTA anticoagulated whole blood from the infected lamb incubated alone or with the equine serum. Glucose concentrations in incubated samples from a control sheep remained stable. Incubation of increasing concentrations of heparinized blood with autologous plasma resulted in decreased glucose concentrations in patient, but not control, blood. As parasitemia decreased after treatment, serum glucose concentration increased, serum lactate concentration decreased, and in vitro glucose concentration stabilized. CONCLUSIONS These findings are consistent with parasite-associated in vitro glucose consumption. An increase in the lamb's plasma glucose concentration associated with reduction of parasite load suggested excess glucose consumption also may have occurred in vivo.
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Affiliation(s)
- Mary Jo Burkhard
- Department of Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
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