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1.
Transbound Emerg Dis ; 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34812571

RESUMO

Porcine circovirus-2 (PCV-2) is associated with several disease syndromes in domestic pigs that have a significant impact on global pig production and health. Currently, little is known about the status of PCV-2 in Africa. In this study, a total of 408 archived DNA samples collected from pigs in Burkina Faso, Cameroon, Cape Verde, Ethiopia, the Democratic Republic of the Congo, Mozambique, Nigeria, Senegal, Tanzania, and Zambia between 2000 and 2018 were screened by PCR for the presence of PCV-2. Positive amplicons of the gene encoding the viral capsid protein (ORF2) were sequenced to determine the genotypes circulating in each country. Four of the nine currently known genotypes of PCV-2 were identified (i.e. PCV-2a, PCV-2b, PCV-2d and PCV-2g) with more than one genotype being identified in Burkina Faso, Ethiopia, Nigeria, Mozambique, Senegal and Zambia. Additionally, a phylogeographic analysis which included 38 additional ORF2 gene sequences of PCV-2s previously identified in Mozambique, Namibia and South Africa from 2014 to 2016 and 2019 to 2020 and available in public databases, demonstrated the existence of several African-specific clusters and estimated the approximate time of introduction of PCV-2s into Africa from other continents. This is the first in-depth study of PCV-2 in Africa and it has important implications for pig production at both the small-holder and commercial farm level on the continent. This article is protected by copyright. All rights reserved.

2.
Transbound Emerg Dis ; 68(5): 2842-2852, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34323385

RESUMO

African swine fever (ASF) has been endemic in sub-Saharan Africa since the 1960s. Following its introduction in Senegal, in 1957, ASF steadily progressed through West Africa, reaching Burkina Faso in 2003, and later Mali in 2016. Despite the heavy burden of disease on pig production, little information is available on the genetic diversity of Africa swine fever virus (ASFV) in Burkina Faso, Mali and Senegal. Here, we used real-time PCR ASFV to detect the ASFV genome in samples collected between 1989 and 2016, in Burkina Faso, Mali and Senegal, and conventional approaches for isolate characterization. The C-terminal end of the p72 protein gene, the full E183L gene and the central variable region (CVR) within the B602L gene in ASFV genome were sequenced and compared to publicly available sequences. ASFV genome was found in 27 samples, 19 from Burkina Faso, three from Mali and five from Senegal. The phylogenetic analyses showed that all viruses belong to genotype I, with the ASFVs from Burkina Faso and Mali grouping with genotype Ia and ASFV serogroup 4, and those from Senegal with genotype Ib and the ASFV serogroup 1. The analysis of the CVR tetrameric tandem repeat sequences (TRS) showed four TRS variants in Burkina Faso, two in Senegal and one in Mali. The three countries did not share any common TRS, and all CVRs of this study differed from previously reported CVRs in West Africa, except for Senegal. Three of the five isolates from Senegal fully matched with the CVR, p72 and p54 sequences from ASFV IC96 collected during the 1996 ASF outbreak in Ivory Coast. This study shows the spread of the same ASFV strains across countries, highlighting the importance of continuous monitoring of ASFV isolates. It also calls for an urgent need to establish a regional plan for the control and eradication of ASF in West Africa.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Doenças dos Suínos , Febre Suína Africana/epidemiologia , Vírus da Febre Suína Africana/genética , Animais , Burkina Faso/epidemiologia , Variação Genética , Genótipo , Mali/epidemiologia , Filogenia , Senegal/epidemiologia , Análise de Sequência de DNA/veterinária , Suínos
3.
Antibiotics (Basel) ; 10(4)2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33917678

RESUMO

Residues of antimicrobials used in farm can exert selective pressure and accelerate the occurrence of multidrug resistant bacteria in litter. This study aimed to investigate the resistance profile of Escherichia coli isolated from poultry litter. A total of 101 E. coli strains was isolated from 229 litter samples collected and stored for two months in the laboratory at room temperature. Antimicrobial susceptibility testing was performed using the disk diffusion method. An overall resistance prevalence of 58.4% (95% CI: 48.8-68.0) was obtained with 59 E. coli strains resistant to various antimicrobial agents. High levels of resistance were observed with ciprofloxacin (21/59: 36%), imipenem (27/59: 45%), norfloxacin (44/59: 74%), ceftriaxone (44/59: 74%), and levofloxacin (44/59: 75%). These antimicrobials classified under the Watch group by WHO are indicators of the high AMR risk to public health in Cameroon. Multivariable logistic regression analysis revealed that a greater probability of high level of E. coli multidrug resistance was associated with lack of training in poultry farming (OR = 0.13, p = 0.01), less experience in poultry farming (OR = 11.66 p = 0.04), and the high frequency of digestive tract disease (OR = 0.10; p = 0.001). This study revealed that poultry litter constitutes a potential source of dissemination of resistant germs from farm animals to the environment and humans.

4.
Trop Anim Health Prod ; 53(2): 214, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33742284

RESUMO

The present study was carried out to establish the spatiotemporal distribution of ASF between 2010 and 2017 in the Adamawa, North, and Far North regions of Cameroon. A retrospective study with data relating to the northern regions from epidemiological reports from target organizations in Cameroon was used to analyze outbreaks of ASF from 2010 to 2016. A prospective study consisting of risk factor analysis and serological investigation of anti-ASF antibodies and ASF RT-PCR antigen detection test in pig farms in the study regions with clinical suspicion of ASF was carried out in 2017. During the period 2010 to 2016, a total of 53 ASF outbreaks were reported and confirmed in the three northern regions of Cameroon and involved 4905 pigs (2232 deaths and 2673 slaughtered for sanitary measures). The seroprevalence for the 2017 serology survey was 5.23% (95% CI [3.57-6.89]) at the individual and 10.81% (95% CI [6.34-15.28]) at herd level. Region, management of farms system, on-farm slaughter by the owner (OR = 4.60; 95% CI [0.34-46.20]; p = 0.014), and selling of animals to community or to butchers (OR = 4.82; 95% CI [0.51-62.15]; p = 0.010) had significant effect on individual level seropositivity of ASF. The viral antigen was not detected by PCR. This study showed that ASF cases have decreased significantly in the northern regions of Cameroon following the epizootic 2010 outbreaks. The findings predict a better future for the pork farming in the regions through the enforcement of strategic measures.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Febre Suína Africana/epidemiologia , Criação de Animais Domésticos , Animais , Camarões/epidemiologia , Surtos de Doenças/veterinária , Estudos Prospectivos , Estudos Retrospectivos , Estudos Soroepidemiológicos , Análise Espaço-Temporal , Suínos
5.
PLoS One ; 15(9): e0239854, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32986759

RESUMO

Brucellosis is a zoonotic disease known to be endemic to parts of western and sub-Saharan Africa. However, the epidemiology for humans and animals remains largely unknown in many of these countries with Cameroon being a typical example. Despite common knowledge that brucellosis affects livestock, the actual number of infected animals remains unknown. Through a scoping review, the current known status of the disease is described. The aim is to ascertain relevant and publicly accessible research and knowledge of human and animal brucellosis in the country, and to provide an overview of the factors associated with its known persistence. Seroprevalence has been estimated and published in 12 separate instances (1 human; 9 cattle; 1 human and cattle; and 1 that includes cattle, pigs, and small ruminants), between 1982 and 2020, in 9 of the country's 10 geopolitical regions. In 1983, Brucella abortus and B. melitensis were isolated in cattle, but no further bacterial isolation has been published since. The seroprevalence from 196 total humans has ranged between 5.6% and 28.1%, and between 3.0% and 30.8% for 14,044 total cattle. As there is no ongoing surveillance program, it is not currently possible to identify the specific Brucella spp. that are endemic to the country and its regions. There are sufficient agricultural systems of cattle, pigs, goats, and sheep to sustain the presence of multiple Brucella spp. Surveillance information is the cornerstone of epidemiologic decision making, and is needed to direct policy makers, public health authorities, and veterinary services to appropriate actions. A combination of serological and molecular based diagnostics for surveillance is necessary to identify, quantify, and direct the appropriate public health interventions. Cameroon has an opportunity to build public and animal health infrastructure, leading the way for central Africa in the management and future eradication of brucellosis.


Assuntos
Brucella abortus/isolamento & purificação , Brucella melitensis/isolamento & purificação , Brucelose/epidemiologia , Brucelose/veterinária , Animais , Brucella abortus/imunologia , Brucella melitensis/imunologia , Brucelose/diagnóstico , Brucelose/microbiologia , Camarões/epidemiologia , Doenças Endêmicas/veterinária , Monitoramento Epidemiológico/veterinária , Humanos , Gado/microbiologia , Estudos Soroepidemiológicos , Zoonoses/epidemiologia , Zoonoses/microbiologia
6.
Antibiotics (Basel) ; 10(1)2020 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-33383622

RESUMO

We conducted a pilot study to assess microbiological safety of chicken litter, an affordable organic and main fertilizer used in Cameroon and worldwide. A convenience sampling of 26 farms was done and a questionnaire was administered. Samples of litter were aseptically collected. E. coli and Salmonella spp. were isolated using CLSI standards. Antibiotic susceptibility testing was performed using the disc diffusion method and a micro broth dilution method for colistin. In broiler farms, 90% of participating farmers gave antibiotic prophylaxis. The prevalence of E. coli and Salmonella spp. was 59.1% and 15.5%, respectively. All E. coli isolates were multidrug resistant as well as 36.4% for Salmonella spp. No resistance was found against cefepime and imipenem. All Salmonella spp. tested were found sensitive to colistin while 26.7% of E. coli spp. were colistin resistant. Contamination of chicken litter may be an underestimated source of antimicrobial resistance (AMR) transmission towards animals, humans and the environment with multidrug resistant E. coli and Salmonella spp. This shows the need and opportunity for a One Health approach in AMR surveillance and control in Cameroon. Continued surveillance in chicken litter would enable monitoring of AMR risks and trends.

7.
Nat Commun ; 10(1): 5310, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757953

RESUMO

The role of Africa in the dynamics of the global spread of a zoonotic and economically-important virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD lineage, remains unexplored. Here we characterise the spatiotemporal patterns of virus diffusion during three HPAI H5Nx intercontinental epidemic waves and demonstrate that Africa mainly acted as an ecological sink of the HPAI H5Nx viruses. A joint analysis of host dynamics and continuous spatial diffusion indicates that poultry trade as well as wild bird migrations have contributed to the virus spreading into Africa, with West Africa acting as a crucial hotspot for virus introduction and dissemination into the continent. We demonstrate varying paths of avian influenza incursions into Africa as well as virus spread within Africa over time, which reveal that virus expansion is a complex phenomenon, shaped by an intricate interplay between avian host ecology, virus characteristics and environmental variables.


Assuntos
Influenza Aviária/transmissão , Influenza Humana/transmissão , Doenças das Aves Domésticas/transmissão , África , África Ocidental , Animais , Humanos , Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A/genética , Influenza Aviária/economia , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Influenza Humana/economia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/economia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia
8.
BMC Public Health ; 19(1): 1135, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31426792

RESUMO

BACKGROUND: Antimicrobial resistance (AMR) is widely acknowledged as a global health problem, yet in many parts of the world its magnitude is not well elucidated. A baseline assessment of the AMR prevalence is a priority for implementation of laboratory-based AMR surveillance This review, focused on a One health approach, aimed at describing the current status of AMR in Cameroon. METHODS: PubMed, Google Scholar and African Journals Online databases were searched for articles published in English and French in accordance with the PRISMA guidelines. Retrieval and screening of article was done using a structured search string with strict inclusion/exclusion criteria. Free-text and grey literature were obtained by contacting the authors directly. The pooled prevalence and 95% confidence intervals were calculated for each pathogen-antibiotic pairs using random-effects models. RESULT: Amongst 97 full-text articles reviewed, 66 met the eligibility criteria. The studies originated from the Centre (24; 36.4%), South-West (16; 24.2%), West (13; 19.7%), Littoral (9; 13.6%) and other (4; 6.1%) regions of Cameroon. These studies reported AMR in human (45; 68.2%), animals (9; 13.6%) and the environment (12; 18.2%). Overall, 19 species of bacteria were tested against 48 antibiotics. These organisms were resistant to all classes of antibiotics and showed high levels of multidrug resistance. Escherichia coli, Klebsiella pneumoniae and Staphylococcus spp were reported in 23, 19 and 18 of the human studies and revealed multidrug resistance (MDR) rates of 47.1% [95% CI (37.3-57.2%)], 51.0% [95% CI (42.0-59.9)] and 45.2% [95% CI (38.0-54.7)], respectively. Salmonella spp was reported in 6 of the animal studies and showed a MDR rate of 46.2% [95% CI (39.2-53.5%)] while Staphylococcus spp in 8 of environment studies showed MDR rate of 67.1% [95% CI (55.2-77.2%)]. CONCLUSION: This review shows that resistance to commonly prescribed antibiotics in Cameroon is high. The findings emphasize the urgent need to address gaps in the standardization of AMR diagnostics, reporting and use of available information to optimize treatment guidelines for the arsenal of antibiotics. Effective AMR surveillance through continued data sharing, large-scale collaboration, and coordination of all stakeholders is essential to understand and manage the AMR national burden.


Assuntos
Farmacorresistência Bacteriana , Saúde Única , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Camarões , Humanos
9.
J Microbiol ; 57(4): 316-324, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30929230

RESUMO

African swine fever (ASF) is a highly lethal haemorrhagic disease in domestic and wild swine that has acquired great importance in sub-Saharan Africa since 1997. ASF was first reported in Cameroon in 1982 and was detected only in Southern Cameroon (South, West, East, Northwest, Southwest, Littoral, and Centre regions) until February 2010 when suspected ASF outbreaks were reported in the North and Far North regions. We investigated those outbreaks by analysing samples that were collected from sick pigs between 2010 and 2018. We confirmed 428 positive samples by ELISA and real-time PCR and molecularly characterized 48 representative isolates. All the identified virus isolates were classified as ASFV genotype I based on the partial B646L gene (C-terminal end of VP72 gene) and the full E183L gene encoding p54 protein analysis. Furthermore, analysis of the central variable region (CVR) within the B602L gene demonstrated that there were 3 different variants of ASFV genotype I, with 19, 20, and 21 tetrameric tandem repeat sequences (TRSs), that were involved in the 2010-2018 outbreaks in Cameroon. Among them, only variant A (19 TRSs) was identical to the Cam/82 isolate found in the country during the first outbreaks in 1981-1982. This study demonstrated that the three variants of ASFV isolates involved in these outbreaks were similar to those of neighbouring countries, suggesting a movement of ASFV strains across borders. Designing common control measures in affected regions and providing a compensation programme for farmers will help reduce the incidence and spread of this disease.


Assuntos
Vírus da Febre Suína Africana/genética , Vírus da Febre Suína Africana/isolamento & purificação , Febre Suína Africana/virologia , Febre Suína Africana/epidemiologia , Vírus da Febre Suína Africana/classificação , Animais , Camarões/epidemiologia , Surtos de Doenças , Variação Genética , Genótipo , Filogenia , Sus scrofa , Suínos
10.
Vector Borne Zoonotic Dis ; 19(7): 455-465, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30985268

RESUMO

Nipah virus (NiV) and Hendra virus (HeV) are closely related members within the genus Henipavirus, family Paramyxoviridae, for which fruit bats serve as the reservoir. The initial emergence of NiV infections in pigs and humans in Malaysia, and HeV infections in horses and humans in Australia, posed severe impacts on human and animal health, and continues threatening lives of humans and livestock within Southeast Asia and Australia. Recently, henipavirus-specific antibodies have also been detected in fruit bats in a number of sub-Saharan African countries and in Brazil, thereby considerably increasing the known geographic distribution of henipaviruses. Africa is progressively being recognized as a new high prevalence zone for henipaviruses, as deduced from serological and molecular evidence of past infections in Madagascar, Ghana, Republic of Congo, Gulf of Guinea, Zambia, Tanzania, Cameroon, and Nigeria lately. Serological data suggest henipavirus spillover from bats to livestock and human populations in Africa without reported clinical disease in any of these species. All virus isolation attempts have been abortive, highlighting the need for further investigations. The genome of the Ghanaian bat henipavirus designated Ghana virus (GhV), which was detected in a pteropid Eidolon helvum bat, is the only African henipavirus that has been completely sequenced limiting our current knowledge on the genetic diversity and pathogenesis of African henipaviruses. In this review, we summarize the available data on the circulation of henipaviruses in Africa, discuss potential sources for virus spillover, and highlight existing research gaps.


Assuntos
Quirópteros/virologia , Infecções por Henipavirus/epidemiologia , Henipavirus , África/epidemiologia , Animais , Anticorpos Antivirais , Infecções por Henipavirus/veterinária , Infecções por Henipavirus/virologia , Humanos , Gado/virologia , Estudos Soroepidemiológicos , Zoonoses/virologia
11.
Emerg Microbes Infect ; 8(1): 186-196, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30866772

RESUMO

From May 2016 to March 2017, 22 poultry outbreaks of avian influenza A(H5N1) were reported in Cameroon, mainly in poultry farms and live bird markets. No human cases were reported. In this study, we sought to describe the 2016 A(H5N1) outbreak strain and to investigate the risk of infection in exposed individuals. We find that highly pathogenic influenza subtype A(H5N1), clade 2.3.2.1c from Cameroon is closely related phylogenetically and antigenically to strains isolated in central and western Africa at the time. No molecular markers of increased human transmissibility were noted; however, seroconversion was detected in two poultry workers (1.5% of total screened). Therefore, the continued outbreaks of avian influenza in poultry and the risk of zoonotic human infection highlight the crucial need for continued and vigilant influenza surveillance and research in Africa, especially in areas of high poultry trade, such as Cameroon.


Assuntos
Surtos de Doenças/veterinária , Virus da Influenza A Subtipo H5N1/imunologia , Influenza Aviária/epidemiologia , Influenza Humana/epidemiologia , Adolescente , Adulto , África Central/epidemiologia , África Ocidental/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Animais , Camarões/epidemiologia , Fazendeiros , Feminino , Humanos , Virus da Influenza A Subtipo H5N1/classificação , Influenza Aviária/imunologia , Influenza Aviária/virologia , Influenza Humana/imunologia , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Filogenia , Filogeografia , Aves Domésticas , Soroconversão , Adulto Jovem , Zoonoses/virologia
12.
Avian Pathol ; 47(6): 559-575, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29985640

RESUMO

In May 2016, highly pathogenic avian influenza virus of the subtype A/H5N1 was detected in Cameroon in an industrial poultry farm at Mvog-Betsi, Yaoundé (Centre region), with a recorded sudden increase of deaths among chickens, and an overall mortality rate of 75%. The virus spread further and caused new outbreaks in some parts of the country. In total, 21 outbreaks were confirmed from May 2016 to March 2017 (six in the Centre, six in the West, eight in the South and one in the Adamaoua regions). This resulted in an estimated total loss of 138,252 birds (44,451 deaths due to infection and 93,801 stamped out). Only domestic birds (chickens, ducks and geese) were affected in farms as well as in poultry markets. The outbreaks occurred in three waves, the first from May to June 2016, the second in September 2016 and the last wave in March 2017. The topology of the phylogeny based on the haemagglutinin gene segment indicated that the causative H5N1 viruses fall within the genetic clade 2.3.2.1c, within the same group as the A/H5N1 viruses collected in Niger in 2015 and 2016. More importantly, the gene constellation of four representative viruses showed evidence of H5N1/H9N2 intra-clade reassortment. Additional epidemiological and genetic data from affected countries in West Africa are needed to better trace the origin, spread and evolution of A/H5N1 in Cameroon. RESEARCH HIGHLIGHTS HPAI A/H5N1 was detected in May 2016 in domestic chickens in Yaoundé-Cameroon. Twenty-one outbreaks in total were confirmed from May 2016 to March 2017. The causative H5N1 viruses fall within the genetic clade 2.3.2.1c. The viral gene constellation showed evidence of H5N1/H9N2 intra-clade reassortment.


Assuntos
Virus da Influenza A Subtipo H5N1/genética , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Vírus Reordenados/genética , Animais , Camarões/epidemiologia , Galinhas/virologia , Surtos de Doenças/veterinária , Patos/virologia , Gansos/virologia , Virus da Influenza A Subtipo H5N1/patogenicidade , Influenza Aviária/epidemiologia , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia , Vírus Reordenados/patogenicidade
14.
Ecohealth ; 15(1): 52-62, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29230614

RESUMO

Recent outbreaks of Ebola virus disease and Zika virus disease highlight the need for disseminating accurate predictions of emerging zoonotic viruses to national governments for disease surveillance and response. Although there are published maps for many emerging zoonotic viruses, it is unknown if there is agreement among different models or if they are concordant with national expert opinion. Therefore, we reviewed existing predictions for five high priority emerging zoonotic viruses with national experts in Cameroon to investigate these issues and determine how to make predictions more useful for national policymakers. Predictive maps relied primarily on environmental parameters and species distribution models. Rift Valley fever virus and Crimean-Congo hemorrhagic fever virus predictions differed from national expert opinion, potentially because of local livestock movements. Our findings reveal that involving national experts could elicit additional data to improve predictions of emerging pathogens as well as help repackage predictions for policymakers.


Assuntos
Zoonoses/epidemiologia , Animais , Animais Selvagens/virologia , Camarões/epidemiologia , Mapeamento Geográfico , Febre Hemorrágica da Crimeia/epidemiologia , Febre Hemorrágica da Crimeia/prevenção & controle , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Febre Lassa/epidemiologia , Febre Lassa/prevenção & controle , Doença do Vírus de Marburg/epidemiologia , Doença do Vírus de Marburg/prevenção & controle , Formulação de Políticas , Febre do Vale de Rift/epidemiologia , Febre do Vale de Rift/prevenção & controle , Zoonoses/prevenção & controle
15.
PLoS One ; 11(4): e0153688, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27123588

RESUMO

Respiratory infections, although showing common clinical symptoms like pneumonia, are caused by bacterial, viral or parasitic agents. These are often reported in sheep and goats populations and cause huge economic losses to the animal owners in developing countries. Detection of these diseases is routinely done using ELISA or microbiological methods which are being reinforced or replaced by molecular based detection methods including multiplex assays, where detection of different pathogens is carried out in a single reaction. In the present study, a one-step multiplex RT-qPCR assay was developed for simultaneous detection of Capripoxvirus (CaPV), Peste de petits ruminants virus (PPRV), Pasteurella multocida (PM) and Mycoplasma capricolum ssp. capripneumonia (Mccp) in pathological samples collected from small ruminants with respiratory disease symptoms. The test performed efficiently without any cross-amplification. The multiplex PCR efficiency was 98.31%, 95.48%, 102.77% and 91.46% whereas the singleplex efficiency was 93.43%, 98.82%, 102.55% and 92.0% for CaPV, PPRV, PM and Mccp, respectively. The correlation coefficient was greater than 0.99 for all the targets in both multiplex and singleplex. Based on cycle threshold values, intra and inter assay variability, ranged between the limits of 2%-4%, except for lower concentrations of Mccp. The detection limits at 95% confidence interval (CI) were 12, 163, 13 and 23 copies/reaction for CaPV, PPRV, PM and Mccp, respectively. The multiplex assay was able to detect CaPVs from all genotypes, PPRV from the four lineages, PM and Mccp without amplifying the other subspecies of mycoplasmas. The discriminating power of the assay was proven by accurate detection of the targeted pathogen (s) by screening 58 viral and bacterial isolates representing all four targeted pathogens. Furthermore, by screening 81 pathological samples collected from small ruminants showing respiratory disease symptoms, CaPV was detected in 17 samples, PPRV in 45, and PM in six samples. In addition, three samples showed a co-infection of PPRV and PM. Overall, the one-step multiplex RT-qPCR assay developed will be a valuable tool for rapid detection of individual and co-infections of the targeted pathogens with high specificity and sensitivity.


Assuntos
Capripoxvirus/genética , Coinfecção/virologia , Mycoplasma capricolum/genética , Pasteurella multocida/crescimento & desenvolvimento , Vírus da Peste dos Pequenos Ruminantes/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Doenças das Cabras/virologia , Cabras/virologia , Infecções por Pasteurella/virologia , Peste dos Pequenos Ruminantes/virologia , Pleuropneumonia Contagiosa/virologia , Infecções por Poxviridae/virologia , RNA Viral/genética , Sensibilidade e Especificidade , Ovinos/virologia , Doenças dos Ovinos/virologia
16.
BMC Vet Res ; 9: 108, 2013 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-23710975

RESUMO

BACKGROUND: Contagious Bovine Pleuropneumonia (CBPP) is the most important chronic pulmonary disease of cattle on the African continent causing severe economic losses. The disease, caused by infection with Mycoplasma mycoides subsp. mycoides is transmitted by animal contact and develops slowly into a chronic form preventing an early clinical diagnosis. Because available vaccines confer a low protection rate and short-lived immunity, the rapid diagnosis of infected animals combined with traditional curbing measures is seen as the best way to control the disease. While traditional labour-intensive bacteriological methods for the detection of M. mycoides subsp. mycoides have been replaced by molecular genetic techniques in the last two decades, these latter approaches require well-equipped laboratories and specialized personnel for the diagnosis. This is a handicap in areas where CBPP is endemic and early diagnosis is essential. RESULTS: We present a rapid, sensitive and specific diagnostic tool for M. mycoides subsp. mycoides detection based on isothermal loop-mediated amplification (LAMP) that is applicable to field conditions. The primer set developed is highly specific and sensitive enough to diagnose clinical cases without prior cultivation of the organism. The LAMP assay detects M. mycoides subsp. mycoides DNA directly from crude samples of pulmonary/pleural fluids and serum/plasma within an hour using a simple dilution protocol. A photometric detection of LAMP products allows the real-time visualisation of the amplification curve and the application of a melting curve/re-association analysis presents a means of quality assurance based on the predetermined strand-inherent temperature profile supporting the diagnosis. CONCLUSION: The CBPP LAMP developed in a robust kit format can be run on a battery-driven mobile device to rapidly detect M. mycoides subsp. mycoides infections from clinical or post mortem samples. The stringent innate quality control allows a conclusive on-site diagnosis of CBPP such as during farm or slaughter house inspections.


Assuntos
Doenças dos Bovinos/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/veterinária , Pleuropneumonia Contagiosa/diagnóstico , Animais , Sequência de Bases , Líquido da Lavagem Broncoalveolar/microbiologia , Bovinos , Doenças dos Bovinos/microbiologia , DNA Bacteriano/genética , Dados de Sequência Molecular , Mycoplasma mycoides/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Pleuropneumonia Contagiosa/microbiologia , Kit de Reagentes para Diagnóstico/veterinária , Sensibilidade e Especificidade
17.
PLoS One ; 8(2): e57509, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23469008

RESUMO

A better understanding of how T1 vaccination confers immunity would facilitate the rational design of improved vaccines against contagious bovine pleuropneumonia (CBPP). We show here that mycoplasmas-induced recall proliferation and IFN-γ responses are detected in cattle that received multiple shots of T1 vaccines. These anamnestic responses were under the strict control of CD4(+) T lymphocytes. Moreover, CD62L expression indicated that both CD4(+) effector memory (Tem) and central memory (Tcm) T lymphocytes are elicited in these animals. Comparative analysis with data from cattle that completely recovered from CBPP infection revealed similar anamnestic T-cell responses albeit at a lower magnitude for T1-vaccinated animals, particularly in the Tcm compartment. In conclusion, we discuss how our current understanding of T-cell responses will contribute to ongoing efforts for the improvement of future CBPP vaccines.


Assuntos
Vacinas Bacterianas/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Doenças dos Bovinos/prevenção & controle , Memória Imunológica , Pleuropneumonia Contagiosa/prevenção & controle , Animais , Vacinas Bacterianas/imunologia , Bovinos , Doenças dos Bovinos/imunologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Pleuropneumonia Contagiosa/imunologia
18.
J Med Virol ; 66(2): 269-75, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11782939

RESUMO

In a survey on the etiology of acute gastroenteritis in infants and young children in Nigeria, group C human rotaviruses were detected in two of 112 rotavirus positive stool specimens collected between 1999 and 2000. The VP7, VP6, and VP4 genes of the two Nigerian human group C rotavirus strains (Jajeri and Moduganari) were sequenced in this study. Comparative sequence analysis with other published human group C rotaviruses showed that the genes encoding the three structural proteins were remarkably conserved in primary structure with few mutations. The VP4 and VP7 genes from the two Nigerian strains were related more closely to each other than to those of other published strains, and formed a separate cluster on the phylogenetic tree. In contrast, it was of note that VP6 gene of strain Moduganari was related more closely to the Brazilian strain Belem than to the other Nigerian strain Jajeri. This is the first report of identification of human group C rotavirus in Nigeria and constitutes the first sequence data of human group C rotaviruses in the African continent.


Assuntos
Antígenos Virais , Proteínas do Capsídeo , Capsídeo/genética , Infecções por Rotavirus/epidemiologia , Rotavirus/classificação , Rotavirus/isolamento & purificação , Análise de Sequência de DNA , Criança , Diarreia/virologia , Fezes/virologia , Humanos , Dados de Sequência Molecular , Nigéria/epidemiologia , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/genética , Infecções por Rotavirus/virologia
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