Browsing by Author "Misinzo, G."

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Antigenic differences among porcine circovirus type 2 strains, as demonstrated by the use of monoclonal antibodies
(Journal of General Virology) Lefebvre, D. J.; Costers, S.; Doorsselaere, J. V.; Misinzo, G.; Delputte, P. L.; Nauwynck, H. J.
Antigenic differences among porcine circovirus type 2 strains, as demonstrated by the use of monoclonal antibodies
(Journal of General Virology, 2008) Lefebvre, D. J.; Costers, S.; Doorsselaere, J. V.; Misinzo, G.; Delputte, P. L.; Nauwynck, H. J.
This study examined whether antigenic differences among porcine circovirus type 2 (PCV-2) strains could be detected using monoclonal antibodies (mAbs). A subtractive immunization protocol was used for the genotype 2 post-weaning multisystemic wasting syndrome (PMWS)-associated PCV-2 strain Stoon-1010. Sixteen stable hybridomas that produced mAbs with an immunoperoxidase monolayer assay (IPMA) titre of 1000 or more to Stoon-1010 were obtained. Staining of recombinant PCV-2 virus-like particles demonstrated that all mAbs were directed against the PCV-2 capsid protein. Cross-reactivity of mAbs was tested by IPMA and neutralization assay for genotype 1 strains 48285, 1206, VC2002 and 1147, and genotype 2 strains 1121 and 1103. Eleven mAbs (9C3, 16G12, 21C12, 38C1, 43E10, 55B1, 63H3, 70A7, 94H8, 103H7 and 114C8) recognized all strains in the IPMA and demonstrated neutralization of Stoon-1010, 48285, 1206 and 1103, but not VC2002, 1147 and 1121. mAbs 31D5, 48B5, 59C6 and 108E8 did not react with genotype 1 strains or had a reduced affinity compared with genotype 2 strains in the IPMA and neutralization assay. mAb 13H4 reacted in the IPMA with PMWS-associated strains Stoon-1010, 48285, 1206 and VC2002, and the porcine dermatitis and nephropathy syndrome-associated strain 1147, but not with reproductive failure-associated strains 1121 and 1103. mAb 13H4 did not neutralize any of the tested strains. It was concluded that, despite the high amino acid identity of the capsid protein (¢91 %), antigenic differences at the capsid protein level are present among PCV-2 strains with a different genetic and clinical background.
Binding and entry characteristics of porcine circovirus 2 in cells of the porcine monocytic line 3D4/31
Misinzo, G.; Meerts, P.; Bublot, M.; Mast, J.; Weingartl, H. M.; Nauwynck, H. J.
Cell tropism and entry of porcine circovirus 2
(Elsevier) Nauwynck, H.J.; Sanchez, R.; Meerts, P.; Lefebvre, D.J.; Saha, D.; Huang, L.; Misinzo, G.
Cell tropism and entry of porcine circovirus 2
(Elsevier, 2011-11-11) Nauwynck, H.J.; Sanchez, R.; Meerts, P.; Lefebvre, D.J.; Saha, D.; Huang, L.; Misinzo, G.
Porcine circovirus 2 (PCV2) may induce reproductive failure (return to oestrus, embryonic death, mum- mification, weak- and stillborn piglets) and postweaning multisystemic wasting syndrome (PMWS). Furthermore, it may modulate the immunity in such a way that it aggravates the outcome of many bacterial and viral infections. In the present paper, the cellular tropism and entry of PCV2 are described and linked with the pathological and clinical consequences.
Clinico-pathological findings of the 2011 outbreak of peste des petits ruminants (PPR) in Tandahimba district, southern Tanzania
(Research Opinions in Animal and Veterinary Sciences) Matondo, R. B.; Muse, E. A.; Karimuribo, E. D.; Misinzo, G.; Albano, M. O.; Gitao, G. C.
Clinico-pathological findings of the 2011 outbreak of peste des petits ruminants (PPR) in Tandahimba district, southern Tanzania
(Research Opinions in Animal and Veterinary Sciences, 2012) Matondo, R. B.; Muse, E. A.; Karimuribo, E. D.; Misinzo, G.; Albano, M. O.; Gitao, G. C.
Although PPR outbreaks were reported in Northern Tanzania since 2008, there has been no description of the clinical or pathological manifestation of the disease, an important criterion in guiding veterinarians and farmers on proper recognition and diagnosis of the disease. A study was therefore conducted to investigate and describe clinical signs and pathological lesions associated with 2011 Peste des petits ruminants (PPR) outbreak in goats and sheep in Tandahimba district located in Southern Tanzania. The investigation involved taking history and conducting clinical examination of PPR suspected cases (25 goats and 3 sheep) in the study district which had neither a history of vaccination against PPR nor previous illness due to PPR. This work was complemented by collection of pathological samples and specimens for laboratory examination. A detailed post-mortem was performed on three sacrificed animals followed by collection of specimens including lungs, liver, spleen and lymph nodes for histopathological examination. Clinical samples from 30 animals which included swabs from ocular, nasal and mouth lesions were also collected for confirmation of PPR through detection of PPR ribonucleic acid using reverse transcription polymerase chain reaction (RT-PCR). Clinical examinations of the cases showed signs suggestive of PPR including severe depression, high fever (41oC), anorexia, muco-pulurent nasal discharge, erosive and necrotic stomatitis, mild diarrhoea and skin nodules. Post mortem examination showed evidence of pneumonia including lung congestion and consolidation, increased thickness of inter-alveolar walls, moderate infiltration of inflammatory cells in bronchiolar subepithelial and perivascular layers. Overall 56.7% of the samples (n=30) tested were positive for PPR by RTPCR. This study has confirmed and described the presence of PPR in southern Tanzania. A more detailed study including other districts is recommended to provide more information regarding the magnitude and factors associated with PPR in Southern Tanzania.
Correlation between the presence of neutralizing antibodies against porcine circovirus 2 (PCV2) and protection against replication of the virus and development of PCV2-associated disease
Meerts, P.; Misinzo, G.; Lefebvre, D.; Nielsen, J.; Bøtner, A.; Kristensen, C. S.; Nauwynck, H. J.
Correlation between the presence of neutralizing antibodies against porcine circovirus 2 (PCV2) and protection against replication of the virus and development of PCV2-associated disease
(2006-01-30) Meerts, P.; Misinzo, G.; Lefebvre, D.; Nielsen, J.; Bøtner, A.; Kristensen, C. S.; Nauwynck, H. J.
Background: In a previous study, it was demonstrated that high replication of Porcine circovirus 2 (PCV2) in a gnotobiotic pig was correlated with the absence of PCV2-neutralizing antibodies. The aim of the present study was to investigate if this correlation could also be found in SPF pigs in which PMWS was experimentally reproduced and in naturally PMWS-affected pigs. Results: When looking at the total anti-PCV2 antibody titres, PMWS-affected and healthy animals seroconverted at the same time point, and titres in PMWS-affected animals were only slightly lower compared to those in healthy animals. In healthy animals, the evolution of PCV2-neutralizing antibodies coincided with that of total antibodies. In PMWS-affected animals, neutralizing antibodies could either not be found (sera from field studies) or were detected in low titres between 7 and 14 DPI only (sera from experimentally inoculated SPF pigs). Differences were also found in the evolution of specific antibody isotypes titres against PCV2. In healthy pigs, IgM antibodies persisted until the end of the study, whereas in PMWS-affected pigs they quickly decreased or remained present at low titres. The mean titres of other antibody isotypes (IgG1, IgG2 and IgA), were slightly lower in PMWS-affected pigs compared to their healthy group mates at the end of each study. Conclusion: This study describes important differences in the development of the humoral immune response between pigs that get subclinically infected with PCV2 and pigs that experience a high level of PCV2-replication which in 3 of 4 experiments led to the development of PMWS. These observations may contribute to a better understanding of the pathogenesis of a PCV2- infection.
Current epidemiological assessment of Bancroftian Filariasis in Tanga region, Northeastern Tanzania
(Hindawi Publishing Corporation) Mshana, H. J.; Baraka, V.; Misinzo, G.; Makunde, W. H.
Distribution and diversity of mosquitoes and the role of Aedes in the transmission of arboviruses in selected districts of Tanzania
Patrick, N. P.; Kinimi, E.; Shayo, M/ J.; Ang eenyi, S. O.; Weyer, P.; van Vuren, P. J.; Paweska, J. T.; Mboera, L. E. G.; Rweyemamu, M. M.; Misinzo, G.; Kasanga, C. J.
Epidemiological investigation into the introduction and factors for spread of Peste des Petits Ruminants, southern Tanzania
Muse, E. A.; Karimuribo, E. D.; Gitao, G. C.; Misinzo, G.; Mellau, L. S. B.; Msoffe, P. L. M.; Swai, E. S.; Albano, M. O.
Evidence of chikungunya virus infection among febrile patients seeking healthcare in selected districts of Tanzania
(Taylor & Francis) Kinimi, E.; Shayo, M. J.; Patrick, B. N.; Angwenyi, S. O.; Kasanga, C. J.; Weyer, J.; Vuren, P. J.; Paweska, J. T.; Mboera, L. E.G.; Misinzo, G.
Evidence of chikungunya virus infection among febrile patients seeking healthcare in selected districts of Tanzania
(Taylor & Francis, 2018) Kinimi, E.; Shayo, M. J.; Patrick, B. N.; Angwenyi, S. O.; Kasanga, C. J.; Weyer, J.; Vuren, P. J.; Paweska, J. T.; Mboera, L. E.G.; Misinzo, G.
Introduction: Chikungunya virus (CHIKV) infection is an emerging mosquito-borne disease that has been associated with frequent epidemics in the world. However, there is a dearth of information on its magnitude and associated risk factors in Tanzania. Objective: A study was conducted to determine seroprevalence of CHIKV among febrile patients seeking medical care at health facilities in Karagwe, Sengerema, Kilombero and Kyela districts. Methods: Structured questionnaires were administered and 728 serum samples were col- lected between May and June, 2015 and tested for the presence of CHIKV-IgM and IgG- specific antibodies using Enzyme-linked immunosorbent assay. Results and discussion: The common clinical characteristics exhibited by outpatients were fever, headache and joint pains (100%, 70%, and 68.3% respectively). Out of 728 outpatients screened for CHIKV, 105 (14%) tested CHIKV IgG positive whilst 11 (1.5%) tested CHIKV IgM positive. Chikungunya seropositivity was significantly higher than previously reported in Tanzania. The most affected age group was 20–29 years. Our results indicate that CHIKV infection is prevalent and contributes to the burden of febrile illnesses in Tanzania. The seroprevalence varies between districts, reflecting variation in mosquito vector transmission dynamics in different parts of the country. Received 23 September 2018 Accepted 19 November 2018 KEYWORDS Chikungunya; seroprevalence; febrile illness; mosquito-borne; Tanzania Abbreviations: CHIKV: Chikungunya virus; EDTA: Ethylenediaminetetraacetic acid; ELISA: Enzyme-linked immunosorbent assay; IgG: Immunoglobulin G; IgM: Immunoglobulin M; NIMR: National Institute for Medical Research; RU: Relative Units; SACIDS: Southern African Centre for Infectious Disease Surveillance; USA: United States of America
Genetic characterization of African swine fever viruses from a 2008 outbreak in Tanzania
Misinzo, G.; Magambo, J.; Masambu, J.; Yongolo, M. G.; Doorsselaere, J. V.; Nauwynck, H. J.
Genetic characterization of African swine fever viruses from a 2008 outbreak in Tanzania
(2011-02) Misinzo, G.; Magambo, J.; Masambu, J.; Yongolo, M. G.; Doorsselaere, J. V.; Nauwynck, H. J.
Outbreaks of African swine fever (ASF) have been reported in the past from several countries in sub-Saharan Africa. The aim of this study was to genotype ASF viruses (ASFVs) from the 2008 outbreak in Morogoro and Dar es Salaam regions of Tanzania. Tissue samples from domestic pigs that died as a result of severe haemorrhagic disease were collected and analysed with PCR and genome sequencing methods using ASFV-specific primer sets. Nucleotide sequence data were obtained for the B646L (p72), E183L (p54) and the variable region of the B602L gene sequences. Phylogenetic analyses based on DNA sequences showed that the 2008 Tanzanian isolates belonged to p72 genotype XV and clustered together with those derived from the 2001 outbreak in Tanzania. Analysis of the tetrameric amino acid repeat regions within the variable region of the B602L gene showed that the repeat signature of the 2008 Tanzanian ASFV was unique and contained three novel tetramers (U = NIDT/NTDT and X = NTDI). Epidemiological investigation suggested that transportation of live pigs continues to play an active role in the epidemiology of ASF in Tanzania. It is recommended that future control of ASF spread in Tanzania should focus on the early detection and confirmation of the disease, prompt institution of quarantine measures, culling and proper disposal of infected and in-contact animals and decontamination of affected premises.
Increased porcine circovirus type 2 replication in porcine leukocytes in vitro and in vivo by concanavalin A stimulation
(Veterinary Microbiolog) Lefebvre, D. J.; Meerts, P.; Costers, S.; Misinzo, G.; Barbe, F.; Reeth, K. V.; Nauwynck, H. J.
Increased porcine circovirus type 2 replication in porcine leukocytes in vitro and in vivo by concanavalin A stimulation
(Veterinary Microbiolog, 2008-05-05) Lefebvre, D. J.; Meerts, P.; Costers, S.; Misinzo, G.; Barbe, F.; Reeth, K. V.; Nauwynck, H. J.
Previously, it was shown that modulation of the immune system enhances porcine circovirus type 2 (PCV2) replication in pigs. In the present study, the effect of the mitogen concanavalin A (ConA) on PCV2 replication was investigated. Since ConA induces T-lymphocyte activation and initiates the production of interferon-gamma (IFN-g), a cytokine that enhances PCV2 replication in porcine epithelial and monocytic cell lines in vitro, it was examined if the effects observed with ConA were mediated by IFN-g. In an in vitro study, ConA but not IFN-g enhanced PCV2 replication in peripheral blood mononuclear cells (PBMC). Up to 2.08% and 0.96% of PBMC were antigen positive for PCV2 strains 1121 and Stoon-1010, respectively, and a low virus production was observed. PCV2-infected PBMC were identified as CD4+ (40%), CD8+ (54%) and IgM+ (11%). In a subsequent in vivo study, caesarean-derived colostrum-deprived piglets were injected with ConA or IFN-g 12 h before inoculation and every 3 days for 9 days after inoculation with strain 1121. PCV2 was isolated from inguinal lymph node biopsies from 10 days post-inoculation (dpi) in ConA-treated pigs and from 15 dpi in non-treated and IFN-g-treated pigs. ConA increased PCV2 replication levels, but disease was not observed. Half of the ConA-treated and IFN-g-treated pigs showed a delayed humoral immune response, but this delay did not result in increased PCV2 replication in these pigs. These experiments demonstrated that ConA enhances PCV2 replication in PBMC in vitro and in lymphoid tissues in vivo. # 2008 Elsevier B.V. All rights reserved.
Increased yield of porcine circovirus-2 by a combined treatment of PK-15 cells with interferon-gamma and inhibitors of endosomallysosomal system acidification
Misinzo, G.; Delputte, P. L.; Lefebvre, D. J.; Nauwynck, H. J.
Partial genetic characterization of peste des petits ruminants virus from goats in northern and eastern Tanzania
(Transboundary and Emerging Diseases) Kgotlele, T.; Macha, E. S.; Kasanga, C. J.; Kusiluka, L. J. M.; Karimuribo, E. D.; Doorsselaere, J. V.; Wensman, J. J.; Munir, M.; Misinzo, G.