ABSTRACT
The laborious microscopic agglutination test (MAT) is the gold standard serologic test for laboratory diagnosis of leptospirosis. We developed EIA based serologic assays using recombinant proteins (rLigA, rLigB, rLipL32) and whole-cell extracts from eight Leptospira serovars as antigen and assessed the diagnostic performance of the new assay within each class, against MAT positive (MAT+) human sera panels from Portugal/PT (n = 143) and Angola/AO (n = 100). We found that a combination of recombinant proteins rLigA, rLigB and rLipL32 correctly identified antigen-specific IgG from patients with clinical and laboratory confirmed leptospirosis (MAT+) with 92% sensitivity and ~ 97% specificity (AUC 0.974) in serum from the provinces of Luanda (LDA) and Huambo (HBO) in Angola. A combination of whole cell extracts of L. interrogans sv Copenhageni (LiC), L. kirschneri Mozdok (LkM), L. borgpetersenii Arborea (LbA) and L. biflexa Patoc (LbP) accurately identified patients with clinical and laboratory confirmed leptospirosis (MAT+) with 100% sensitivity and ~ 98% specificity for all provinces of Angola and Portugal (AUC: 0.997 for AO/LDA/HBO, 1.000 for AO/HLA, 0.999 for PT/AZ and 1.000 for PT/LIS). Interestingly, we found that MAT+ IgG+ serum from Angola had a significantly higher presence of IgD and that IgG3/IgG1 isotypes were significantly increased in the MAT+ IgG+ serum from Portugal. Given that IgM/IgD class and IgG3/IgG1 specific isotypes are produced in the earliest course of infection, immunoglobulin G isotyping may be used to inform diagnosis of acute leptospirosis. The speed, ease of use and accuracy of EIA tests make them excellent alternatives to the laborious and expensive MAT for screening acute infection in areas where circulating serovars of pathogenic Leptospira are well defined.
Subject(s)
Leptospira , Leptospirosis , Acute Disease , Agglutination Tests , Antibodies, Bacterial , Antigens, Bacterial , Cell Extracts , Enzyme-Linked Immunosorbent Assay , Humans , Immunoenzyme Techniques , Immunoglobulin D , Immunoglobulin G , Recombinant Proteins , Serologic TestsABSTRACT
The utility of mitochondrial cytochrome oxidase subunit I (COX1) and 16S ribosomal DNA (16S-rDNA) sequence analyses as a complementary/alternative tool to classical taxonomy, for the identification of some of the most prevalent hard tick species from Portugal was evaluated using BOLD-ID (COX1 only), BLASTn and phylogenetic tree reconstruction based on multiple nucleotide sequence alignments. Both molecular markers proved suitable for identifying ticks to a species level, but specific aspects that limit their resolving power must be considered. Their accuracy of tick identification in all life stages and of the other tick species described in the South of Europe is required.
Subject(s)
Ticks , Animals , DNA, Ribosomal/genetics , Electron Transport Complex IV/genetics , Phylogeny , Portugal , RNA, Ribosomal, 16S/genetics , Ticks/geneticsABSTRACT
The large diversity of new tick-borne phleboviruses, and the negative impacts of the virulent viruses on human/animal health have led to a growing interest in their analysis. In this report, new insights are brought out into the diversity of putative phleboviruses circulating in Portugal (both the continental territory and the islands of São Miguel, in the Azores, and Madeira), as well as in the Spanish western regions of Extremadura and Castilla and León. Phlebovirus sequences were frequently detected (L-segment) from both questing and feeding ticks, but especially in Rhipicephalus sanguineus sensu lato (s.l.) specimens. These sequences were detected in adult ticks, as well as nymphs and eggs, supporting the hypothesis of viral maintenance by vertical transmission. Though multiple genetic groups could be identified in phylogenetic trees (AnLuc, KarMa, RiPar virus 1, and Spanish group 1 and 2), all the sequences from Portugal and Spain shared common ancestry with other viral sequence obtained from samples collected over a large geographic coverage. Spatiotemporal analysis placed Middle-East as the geographic origin of the most recent common ancestor (MRCA) of all phleboviruses analysed in the present study. More recent viral transitions might include migrations from Spain to continental Portugal, and from there to the Portuguese Islands. Our findings suggest that the time of the MRCA of phleboviruses was dated around 225 years ago [95% HPD: 124-387 year before the last sampling date].
Subject(s)
Genetic Variation , Phlebovirus/genetics , Phylogeny , Rhipicephalus sanguineus/virology , Animals , Geography , Infectious Disease Transmission, Vertical , Nymph/virology , Ovum/virology , Phlebovirus/physiology , Portugal , RNA Viruses/genetics , RNA, Viral/genetics , Sequence Analysis, DNA , Spain , Spatio-Temporal AnalysisABSTRACT
Ticks are vectors of many human and animal pathogens. The aim of this study was to screen bacteria and protozoa from ticks infesting domestic animals and wildlife collected in central and southern Portugal. A total of 593 ticks, comprising 465 (78.4%) adults, 122 (20.6%) nymphs, and six (1.0%) larvae, were collected from 283 hosts of 25 different species (4 domestic and 21 wild). Overall, the analysis of DNA extracts prepared from ticks collected from hosts of 11 different species in the districts of Castelo Branco, Portalegre, Lisboa, Setúbal, Beja and Faro, revealed the presence of genomic sequences from Anaplasma sp., A. ovis, Babesia sp., relapsing fever-like Borrelia sp., Ehrlichia spp., Rickettsia aeschlimannii, Ri. helvetica, Ri. massiliae, Ri. raoultii, Ri. slovaca, Candidatus Ri. barbariae, Theileria annulata and T. ovis, in specimens of Dermacentor marginatus, Hyalomma lusitanicum, Hy. marginatum, Rhipicephalus bursa and Rh. sanguineus sensu lato. The obtained results suggest the circulation of a wide variety of infectious agents, some of zoonotic concern, in hard ticks from Portugal. Further studies should be conducted to better characterize (both genetically and phenotypically) the putative novel microorganisms detected, both in what regards their potential pathogenity towards vertebrates, and to assist the implementation of effective control strategies for the management of ticks and human and animal tick-borne pathogens.
Subject(s)
Babesia/isolation & purification , Bacteria/isolation & purification , Ixodidae/microbiology , Ixodidae/parasitology , Theileria/isolation & purification , Animals , Animals, Domestic/parasitology , Animals, Wild/parasitology , Portugal , Tick Infestations/veterinaryABSTRACT
Nowadays, at least four clinically important B. burgdorferi sensu lato (s.l.) genospecies (B. afzelii, B. garinii, B. burgdorferi sensu stricto (s.s.) and B. lusitaniae) circulate in Portugal. Each genospecies has a different tropism that resuls in a diverse array of clinical manifestations. The standard diagnostic procedure used is normally simple, nevertheless, during the "window-period" phase, in which specific antibodies cannot yet be detected, diagnosis becomes difficult, and calls for reliable, sensitive and specific laboratory methods, such as molecular tests. The aim of this study was to develop and evaluate a multiplex TaqMan real-time PCR assay to infer the presence of B. burgdorferi s.l. genospecies in clinical and vector-derived samples. The assay consists of two steps: (i) a first duplex real-time PCR targeting both flaB of B. burgdorferi s.l., and an internal control (18S rDNA for tick samples or the mammal ß-actin gene for clinical samples); and (ii) a second tetraplex real-time PCR targeting the flaB gene of B. afzelii, B. garinii, B. burgdorferi s.s. and B. lusitaniae. The first step revealed a high specificity and sensitivity, allowing the detection of as low as 20 genome equivalents (GE) of B. burgdorferi s.l. from isolated cultures, clinical samples and ticks. The second step revealed high specificity, but a slightly lower sensitivity (2×102 GE) for detection of B. afzelii, B. garinii, B. burgdorferi s.s. and B. lusitaniae in purified DNA extracts, and particularly when testing cerebrospinal fluid (CSF) samples. Nonetheless, both real-time PCR protocols were developed to be applied at the beginning of the infection, to improve early diagnosis of Lyme borreliosis (LB), where detection of Borrelia should not rely on the use of CSF samples. The assay here described is of special interest for the analysis of both environmental and clinical samples, being advantageous in the former phase screening of Lyme borreliosis, when the efficiency of serologically based diagnoses may be seriously compromised.
Subject(s)
Borrelia burgdorferi Group/isolation & purification , DNA, Bacterial/analysis , Flagellin/analysis , Lyme Disease/diagnosis , Real-Time Polymerase Chain Reaction/methods , Animals , Ixodidae/microbiology , Portugal , RNA, Ribosomal, 18S/analysisABSTRACT
INTRODUCTION: Leptospirosis is a neglected zoonotic disease caused by a bacteria of the genus Leptospira. In Africa it is frequently mistaken for frequently occurring conditions such as malaria. The aim of this study was to identify rodent species involved in the transmission of the disease, the prevalence of pathogenic Leptospira spp. in selected rodent species and risk factors for human leptospirosis. MATERIAL AND METHODS: We conducted a descriptive and exploratory epidemiological and molecular study in Mozambique Island city in 2015. Six neighborhoods, comprising 30 households each were randomly selected. People from the selected 180 households were interviewed regarding their awareness of the disease, the presence of rodents in their houses, chemicals used to eliminate them, sewage disposal, water supply system, and other key issues related to the disease. In each neighborhood we trapped 10 rodents for morphometric study to identify their species and for molecular isolation of Leptospira DNA. We extracted kidneys from 57/60 of rodents trapped, and performed nested polymerase chain reaction targeting rrs 16S ribosomal DNA and lipL32 genes for identification of Leptospira genus and pathogenic Leptospira spp. respectively. RESULTS: Of the 180 participants 92 (51%) reported having heard of leptospirosis; 107 (59%) have had the disease; 151 (83%) reported the existence of rats in their house; 100 (56%) had latrines; 118 (66%) used chemicals to kill the rats; 102 (57%) used well water and 114 (63%) used trash containers. The most prevalent rodent species captured was Rattus norvegicus 36/60 (60%), followed by Rattus rattus 19/60 (31.67%) and Mus musculus 3/60 (5%). rrs 16S ribosomal DNA was identified in 20/57 (35.%) rodents. Out these two were positive for lipL32 gene, giving an overall pathogenic Leptospira infection of 3.5% (2/57). The rodent species identified as carriers of pathogenic Leptospira were Rattus norvegicus (1) and R. rattus (1). CONCLUSION: This is the first study in Mozambique to identify the presence of pathogenic species of Leptospira using molecular tools. Leptospirosis risk factors in Mozambique Island city are rodent's infestation, limited disease awareness, lack of access to clean water, insufficient resources for waste collection, greater clustering of households, poor sanitation environment and degradation of living conditions. Pathogenic Leptospira spp. are present in the area studied and at least two species of rodents, the R. rattus and R. norvegi-cus are potentially involved in the transmission of the causal agents of the disease.
ABSTRACT
In the last decade, various research groups have reported a large diversity of new tick-borne phleboviruses, mostly prompted by the discovery of important human pathogens such as the Heartland and severe fever with thrombocytopenia syndrome viruses. Since these analyses have rarely been conducted using ticks collected from Southern Europe, this study was carried out so as to bring new insights into the diversity of phleboviruses circulating in Southern Portugal. Tick specimens were collected from the vegetation (questing ticks) or directly from animals (feeding ticks), and the majority analysed in pools using a detection strategy targeting the large (L) viral genomic segment. A high number of pools revealed the presence of phebovirus sequences, regardless of gender (male/female), origin (questing/feeding) or even species of the tick analysed. These sequences apparently formed three different groups in phylogenetic trees, and encoded L proteins characterized by group-specific amino acid residues. Furthermore, under the conditions used, these viruses failed to replicate in both Vero and DH82 cells. The impact these viruses may have on human/animal health will be addressed in the future.
Subject(s)
Ixodidae/virology , Phlebovirus/genetics , Animals , Cell Line , Phlebovirus/isolation & purification , PortugalABSTRACT
The aims of the present study were to serosurvey dogs, horses, and humans highly exposed to tick bites for anti-Borrelia burgdorferi s.l. antibodies, identify tick species present, and determine risk factors associated with seropositivity in a rural settlement of Paraná State, southern Brazil. Eighty-seven residents were sampled, along with their 83 dogs and 18 horses, and individual questionnaires were administered. Immunofluorescence antibody test (IFAT) was performed on serum samples and positive samples were subjected to western blot (WB) analysis. Anti-B. burgdorferi antibodies were found in 4/87 (4.6%) humans, 26/83 (31.3%) dogs, and 7/18 (38.9%) horses by IFAT, with 4/4 humans also positive by WB. Ticks identified were mostly from dogs and included 45/67 Rhipicephalus sanguineus, 21/67 Amblyomma ovale, and 1/67 A. cajennense sensu lato. All (34/34) horse ticks were identified as A. cajennense s.l.. No significant association was found when age, gender, or presence of ticks was correlated to seropositivity to Borrelia sp. In conclusion, although anti-Borrelia antibodies have been found in dogs, horses and their owners from the rural settlement, the lack of isolation, molecular characterization, absence of competent vectors and the low specificity of the commercial WB kit used herein may have impaired risk factor analysis.
Subject(s)
Antibodies, Bacterial/blood , Borrelia burgdorferi Group/immunology , Ticks/microbiology , Animals , Brazil , Dogs , Horses , Humans , Ixodidae/microbiology , Rhipicephalus sanguineus/microbiology , Rural HealthABSTRACT
Abstract The aims of the present study were to serosurvey dogs, horses, and humans highly exposed to tick bites for anti-Borrelia burgdorferi s.l. antibodies, identify tick species present, and determine risk factors associated with seropositivity in a rural settlement of Paraná State, southern Brazil. Eighty-seven residents were sampled, along with their 83 dogs and 18 horses, and individual questionnaires were administered. Immunofluorescence antibody test (IFAT) was performed on serum samples and positive samples were subjected to western blot (WB) analysis. Anti-B. burgdorferi antibodies were found in 4/87 (4.6%) humans, 26/83 (31.3%) dogs, and 7/18 (38.9%) horses by IFAT, with 4/4 humans also positive by WB. Ticks identified were mostly from dogs and included 45/67 Rhipicephalus sanguineus, 21/67 Amblyomma ovale, and 1/67 A. cajennense sensu lato. All (34/34) horse ticks were identified as A. cajennense s.l.. No significant association was found when age, gender, or presence of ticks was correlated to seropositivity to Borrelia sp. In conclusion, although anti-Borrelia antibodies have been found in dogs, horses and their owners from the rural settlement, the lack of isolation, molecular characterization, absence of competent vectors and the low specificity of the commercial WB kit used herein may have impaired risk factor analysis.
Resumo Os objetivos do presente estudo foram realizar um levantamento sorológico de cães, cavalos e humanos altamente expostos a picadas de carrapatos para anticorpos anti-B. burgdorferi s.l., identificar as espécies de carrapatos presentes, e determinar os fatores de risco associados a soropositividade em um assentamento rural do Estado do Paraná, sul do Brasil. Oitenta e sete residentes foram amostrados junto com seus respectivos 83 cães e 118 cavalos e questionários individuais foram aplicados. O teste de imunofluorescência indireta (IFI) foi realizado nas amostras sorológicas e as positivas foram submetidas a análise por western blot (WB). Anticorpos anti-B. burgdorferi foram detectados em 4/87 (4,6%) humanos, 26/83 (31,3%) cães e 7/18 (38,9%) cavalos pela IFI, com 4/4 humanos também positivos pelo WB. Os carrapatos identificados foram em sua maioria de cães e incluíram 45/67 Rhipicephalus sanguineus, 21/67 Amblyomma ovale e 1/67 A. cajennense sensu lato. Todos (34/34) carrapatos dos cavalos foram identificados como A. cajennense s.l.. Não foram observadas diferenças estatísticas entre idade, sexo ou presença de carrapatos e soropositividade para Borrelia sp. Em conclusão, embora anticorpos anti-Borrelia tenham sido encontrados em cães, equinos e seus proprietários do assentamento rural, a ausência de isolamento, caracterização molecular, ausência de vetores competentes e baixa especificidade do kit comercial de WB utilizado podem ter limitado a análise de fatores de risco.
Subject(s)
Humans , Animals , Dogs , Ticks/microbiology , Borrelia burgdorferi Group/immunology , Antibodies, Bacterial/blood , Brazil , Rural Health , Ixodidae/microbiology , Rhipicephalus sanguineus/microbiology , HorsesABSTRACT
BACKGROUND: Wildlife can act as reservoir of different tick-borne pathogens, such as bacteria, parasites and viruses. The aim of the present study was to assess the presence of tick-borne bacteria and protozoa with veterinary and zoonotic importance in cervids and wild boars from the Centre and South of Portugal. METHODS: One hundred and forty one blood samples from free-ranging ungulates including 73 red deer (Cervus elaphus), 65 wild boars (Sus scrofa) and three fallow deer (Dama dama) were tested for the presence of Anaplasma marginale/A. ovis, A. phagocytophilum, Anaplasma/Ehrlichia spp., Babesia/Theileria spp., Borrelia burgdorferi (sensu lato) (s.l.), and Rickettsia spp. DNA by PCR. RESULTS: Anaplasma spp. DNA was detected in 33 (43.4 %) cervids (31 red deer and two fallow deer) and in two (3.1 %) wild boars while Theileria spp. were found in 34 (44.7 %) cervids (32 red deer and two fallow deer) and in three (4.6 %) wild boar blood samples. Sequence analysis of msp4 sequences identified A. marginale, A. ovis, while the analysis of rDNA sequence data disclosed the presence of A. platys and A. phagocytophilum and T. capreoli and Theileria sp. OT3. Anaplasma spp./Theileria spp. mixed infections were found in 17 cervids (22.4 %) and in two wild boars (3.1 %). All samples were negative for Babesia sp., B. burgdorferi (s.l.), Ehrlichia sp. or Rickettsia sp. CONCLUSIONS: This is the first detection of Anaplasma marginale, A. ovis, A. phagocytophilum, A. platys, Theileria capreoli and Theileria sp. OT3 in cervids and wild boars from Portugal. Further studies concerning the potential pathogenicity of the different species of Anaplasma and Theileria infecting wild ungulates, the identification of their vector range, and their putative infectivity to domestic livestock and humans should be undertaken.
Subject(s)
Anaplasma/isolation & purification , Deer , Swine Diseases/epidemiology , Theileria/isolation & purification , Tick-Borne Diseases/veterinary , Ticks , Anaplasma/genetics , Animals , Babesia/genetics , Babesia/isolation & purification , Borrelia burgdorferi/genetics , Borrelia burgdorferi/isolation & purification , Deer/microbiology , Deer/parasitology , Disease Reservoirs/veterinary , Ehrlichia/genetics , Ehrlichia/isolation & purification , Female , Male , Phylogeny , Portugal/epidemiology , Rickettsia/genetics , Rickettsia/isolation & purification , Sequence Analysis, DNA/veterinary , Sus scrofa , Swine , Swine Diseases/microbiology , Swine Diseases/parasitology , Theileria/genetics , Tick-Borne Diseases/epidemiology , Tick-Borne Diseases/microbiology , Tick-Borne Diseases/parasitology , Ticks/microbiology , Ticks/parasitologyABSTRACT
Rodents play an important role in the transmission of pathogenic Leptospira spp. However, in Angola, neither the natural reservoirs of these spirochetes nor leptospirosis diagnosis has been considered. Regarding this gap, we captured rodents in Luanda and Huambo provinces to identify circulating Leptospira spp. Rodent kidney tissue was cultured and DNA amplified and sequenced. Culture isolates were evaluated for pathogenic status and typing with rabbit antisera; polymerase chain reaction (PCR) and sequencing were also performed. A total of 37 rodents were captured: Rattus rattus (15, 40.5%), Rattus norvegicus (9, 24.3%), and Mus musculus (13, 35.2%). Leptospiral DNA was amplified in eight (21.6%) kidney samples. From the cultures, we obtained four (10.8%) Leptospira isolates belonging to the Icterohaemorrhagiae and Ballum serogroups of Leptospira interrogans and Leptospira borgpetersenii genospecies, respectively. This study provides information about circulating leptospires spread by rats and mice in Angola.
Subject(s)
Leptospira/classification , Leptospirosis/veterinary , Rodent Diseases/microbiology , Angola/epidemiology , Animals , Leptospira/genetics , Leptospirosis/epidemiology , Leptospirosis/microbiology , Mice , Phylogeny , Polymerase Chain Reaction , Rats , Rodent Diseases/epidemiologyABSTRACT
This study describes the detection of Borrelia garinii and Borrelia burgdorferi sensu stricto (s.s.) in Brazilian individuals using PCR and DNA sequencing. Our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in Brazil.
Subject(s)
Borrelia burgdorferi Group/classification , Borrelia burgdorferi Group/isolation & purification , Communicable Diseases, Emerging/microbiology , Lyme Disease/microbiology , Adolescent , Adult , Aged , Base Sequence , Brazil/epidemiology , Communicable Diseases, Emerging/epidemiology , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Female , Humans , Lyme Disease/epidemiology , Male , Middle Aged , Molecular Sequence Data , Polymerase Chain Reaction , Rural Population , Sequence Alignment , Sequence Analysis, DNA , Young AdultABSTRACT
This study describes the detection of Borrelia garinii and Borrelia burgdorferi sensu stricto (s.s.) in Brazilian individuals using PCR and DNA sequencing. Our results suggest that these species are emerging pathogens in this country, and additional studies are necessary to determine the epidemiological characteristics of this disease in Brazil.
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Borrelia burgdorferi Group/classification , Borrelia burgdorferi Group/isolation & purification , Communicable Diseases, Emerging/microbiology , Lyme Disease/microbiology , Base Sequence , Brazil/epidemiology , Communicable Diseases, Emerging/epidemiology , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Lyme Disease/epidemiology , Molecular Sequence Data , Polymerase Chain Reaction , Rural Population , Sequence Alignment , Sequence Analysis, DNAABSTRACT
BACKGROUND: The so-called canine vector-borne diseases (CVBD) are caused by a wide range of pathogens transmitted by arthropods. In addition to their veterinary importance, many of these canine vector-borne pathogens can also affect the human population due to their zoonotic potential, a situation that requires a One Health approach. As the prevalence of vector-borne pathogens in cats from southern Portugal has been recently evaluated, the aim of the present study was to assess if the same agents were present in dogs living in the same area, and to assess positivity-associated risk factors. METHODS: One thousand and ten dogs (521 domestic and 489 stray) from veterinary medical centres and animal shelters in southern Portugal were enrolled. Anaplasma spp./Ehrlichia spp., Bartonella spp., Borrelia burgdorferi sensu lato, Babesia spp., Hepatozoon spp. and Leishmania infantum infections were evaluated by polymerase chain reaction (PCR) assays in blood samples. RESULTS: Sixty-eight (6.7%) dogs were PCR-positive to at least one of the tested CVBD agent species, genera or complex, including one dog found positive to two different genera. Nineteen (1.9%) dogs were positive to Anaplasma spp./Ehrlichia spp., eight (0.8%) to B. burgdorferi s.l., 31 (3.1%) to Hepatozoon spp. and 11 (1.1%) to L. infantum. Anaplasma platys, Ehrlichia canis, B. burgdorferis.l. and Hepatozoon canis were identified by DNA sequencing, including one animal confirmed with both A. platys and H. canis. Furthermore, Wolbachia spp. was amplified in blood from four dogs. None of the tested dogs was positive by PCR for Bartonella spp. or Babesia spp. CONCLUSIONS: The molecular identification of CVBD agents in southern Portugal, some of them with zoonotic concern, reinforces the importance to alert the veterinary community, owners and public health authorities to prevent the risk of transmission of vector-borne pathogens among dogs and to other vertebrate hosts including humans. The prevalence of the selected pathogens was lower than that previously found in cats from the same region, probably because veterinarians and owners are more aware of them in the canine population and control measures are used more often.
Subject(s)
Bacteria/isolation & purification , Bacterial Infections/veterinary , Blood/microbiology , Blood/parasitology , Dog Diseases/epidemiology , Parasites/isolation & purification , Protozoan Infections, Animal/parasitology , Animals , Bacteria/classification , Bacterial Infections/epidemiology , Bacterial Infections/microbiology , Disease Transmission, Infectious , Dog Diseases/microbiology , Dog Diseases/parasitology , Dogs , Molecular Diagnostic Techniques , Parasites/classification , Polymerase Chain Reaction , Portugal/epidemiology , Protozoan Infections, Animal/epidemiology , Risk Assessment , Zoonoses/transmissionABSTRACT
Leptospirosis is a growing public and veterinary health concern caused by pathogenic species of Leptospira. Rapid and reliable laboratory tests for the direct detection of leptospiral infections in animals are in high demand not only to improve diagnosis but also for understanding the epidemiology of the disease. In this work we describe a novel and simple TaqMan-based multi-gene targeted real-time PCR approach able to detect and differentiate Leptospira interrogans, L. kirschneri, L. borgpeteresenii and L. noguchii, which constitute the veterinary most relevant pathogenic species of Leptospira. The method uses sets of species-specific probes, and respective flanking primers, designed from ompL1 and secY gene sequences. To monitor the presence of inhibitors, a duplex amplification assay targeting both the mammal ß-actin and the leptospiral lipL32 genes was implemented. The analytical sensitivity of all primer and probe sets was estimated to be <10 genome equivalents (GE) in the reaction mixture. Application of the amplification reactions on genomic DNA from a variety of pathogenic and non-pathogenic Leptospira strains and other non-related bacteria revealed a 100% analytical specificity. Additionally, pathogenic leptospires were successfully detected in five out of 29 tissue samples from animals (Mus spp., Rattus spp., Dolichotis patagonum and Sus domesticus). Two samples were infected with L. borgpetersenii, two with L. interrogans and one with L. kirschneri. The possibility to detect and identify these pathogenic agents to the species level in domestic and wildlife animals reinforces the diagnostic information and will enhance our understanding of the epidemiology of leptopirosis.
Subject(s)
Genes, Bacterial , Leptospira/genetics , Real-Time Polymerase Chain Reaction/methods , Animals , DNA Primers/metabolism , DNA Probes/metabolism , Leptospira/isolation & purification , Mice , Rats , Sensitivity and Specificity , Species SpecificityABSTRACT
BACKGROUND: Leptospirosis is a worldwide zoonotic and recognized neglected infectious disease. It has been observed that only a proportion of individuals exposed to pathogenic species of Leptospira become infected and develop clinically evident disease. Moreover, little information is available in subsequent reinfections. In the present study, we determine if a first infection with leptospirosis protects against subsequent reinfection, and investigate which of the host genetic factors are involved in the susceptibility and resistance to leptospirosis. METHODOLOGY AND FINDINGS: We conducted, in 2011, a retrospective hospital-based case-control study in the São Miguel Island population (Azores archipelago). In order to determine the seropositivity against pathogenic Leptospira after the first episode of leptospirosis, we performed a serological evaluation in 97 unrelated participants diagnosed with leptospirosis between 1992 and 2011. The results revealed that 46.4% of the 97 participants have circulating anti-Leptospira antibodies, and from these participants 35.6% maintained the seroprevalence for the same serogroup. Moreover, three of them were reinfected with unrelated Leptospira serovars. The genetic study was carried out by adding a control group composed of 470 unrelated healthy blood donors, also from São Miguel Island. Twenty five SNPs among twelve innate immune genes - IL1α, IL1ß, IL6, IL10, IL12RB1, TLR2, TLR4, TLR9, CD14, CISH, LTA and TNF - were genotyped, as well as HLA class I (-A and -B) genes. Association analysis indicates that genotypes -511GG (OR=1.6, 95%CI 1.01-2.56, p=0.04) in IL1ß, +1196CG (OR=2.0, 95%CI 1.26-3.27, p=0.003) in IL12RB1, -292TA (OR=1.8, 95% CI 1.06-2.1, p=0.03) and +3415CG (OR=1.8, 95% CI 1.08-3.08, p=0.02), both in CISH confer susceptibility to pathogenic Leptospira. CONCLUSION: The present study suggests some degree of long-term protection against leptospires with an attenuation of symptoms in case of reinfection. Moreover, our data supports the genetic influence of IL1ß, IL12RB1 and CISH genes and the susceptibility to leptospirosis infection.
Subject(s)
Leptospira/classification , Leptospirosis/epidemiology , Leptospirosis/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Alleles , Azores/epidemiology , Case-Control Studies , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Retrospective Studies , Seroepidemiologic Studies , Young AdultABSTRACT
Ticks are important vector arthropods of human and animal pathogens. As information about agents of disease circulating in vectors in Portugal is limited, the aim of the present study was to detect bacteria and parasites with veterinary and zoonotic importance in ticks collected from dogs, cats, and field vegetation. A total of 925 ticks, comprising 888 (96.0%) adults, 8 (0.9%) nymphs, and 29 (3.1%) larvae, were collected in 4 geographic areas (districts) of Portugal. Among those, 620 (67.0%) were removed from naturally infested dogs, 42 (4.5%) from cats, and 263 (28.4%) were questing ticks obtained from field vegetation. Rhipicephalus sanguineus was the predominant tick species, and the only one collected from dogs and vegetation, while all Ixodes ricinus specimens (n=6) were recovered from cats. Rickettsia massiliae and Rickettsia conorii were identified in 35 ticks collected from cats and dogs and in 3 ticks collected from dogs. Among ticks collected from cats or dogs, 4 Rh. sanguineus specimens were detected with Hepatozoon felis, 3 with Anaplasma platys, 2 with Hepatozoon canis, one with Anaplasma phagocytophilum, one with Babesia vogeli, one with Borrelia burgdorferi sensu lato and one with Cercopithifilaria spp. Rickettsia helvetica was detected in one I. ricinus tick collected from a cat. To the best of our knowledge, this was the first time that Cercopithifilaria spp., Ba. vogeli, H. canis, and H. felis have been detected in ticks from Portugal. The wide range of tick-borne pathogens identified, some of zoonotic concern, suggests a risk for the emergence of tick-borne diseases in domestic animals and humans in Portugal. Further studies on these and other tick-borne agents should be performed to better understand their epidemiological and clinical importance, and to support the implementation of effective control measures.
Subject(s)
Arachnid Vectors/classification , Cat Diseases/epidemiology , Dog Diseases/epidemiology , Ixodes/classification , Rhipicephalus sanguineus/classification , Tick-Borne Diseases/veterinary , Anaplasma/genetics , Anaplasma/isolation & purification , Animals , Arachnid Vectors/microbiology , Arachnid Vectors/parasitology , Babesia/genetics , Babesia/isolation & purification , Borrelia/genetics , Borrelia/isolation & purification , Cat Diseases/microbiology , Cat Diseases/parasitology , Cats , Coccidia/genetics , Coccidia/isolation & purification , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Dog Diseases/microbiology , Dog Diseases/parasitology , Dogs , Female , Filarioidea/genetics , Filarioidea/isolation & purification , Geography , Ixodes/microbiology , Ixodes/parasitology , Larva , Male , Nymph , Portugal/epidemiology , Rhipicephalus sanguineus/microbiology , Rhipicephalus sanguineus/parasitology , Rickettsia/genetics , Rickettsia/isolation & purification , Sequence Analysis, DNA , Tick-Borne Diseases/epidemiology , Tick-Borne Diseases/microbiology , Tick-Borne Diseases/parasitologyABSTRACT
BACKGROUND: Feline vector-borne diseases (FVBD) have emerged in recent years, showing a wider geographic distribution and increased global prevalence. In addition to their veterinary importance, domestic cats play a central role in the transmission cycles of some FVBD agents by acting as reservoirs and sentinels, a circumstance that requires a One Health approach. The aim of the present work was to molecularly detect feline vector-borne bacteria and protozoa with veterinary and zoonotic importance, and to assess associated risk factors in cats from southern Portugal. METHODS: Six hundred and forty-nine cats (320 domestic and 329 stray), from veterinary medical centres and animal shelters in southern Portugal, were studied. Anaplasma spp./Ehrlichia spp., Babesia spp., Bartonella spp., Borrelia burgdorferi sensu lato, Hepatozoon spp. and Leishmania spp. infections were evaluated by polymerase chain reaction (PCR) in blood samples. RESULTS: One hundred and ninety-four (29.9%) cats were PCR-positive to at least one of the tested genera or complex of FVBD agents. Sixty-four (9.9%) cats were positive to Leishmania spp., 56 (8.6%) to Hepatozoon spp., 43 (6.6%) to Babesia spp., 35 (5.4%) to Anaplasma spp./Ehrlichia spp., 19 (2.9%) to Bartonella spp. and 14 (2.2%) to B. burgdorferi s.l. Thirty-three (5.1%) cats were positive to two (n = 29) or three (n = 4) genera/complex. Babesia vogeli, Bartonella clarridgeiae, Bartonella henselae, Ehrlichia canis, Hepatozoon felis and Leishmania infantum were identified by DNA sequencing. CONCLUSIONS: The occurrence of FVBD agents in southern Portugal, some of them with zoonotic character, emphasizes the need to alert the veterinary community, owners and public health authorities for the risk of infection. Control measures should be implemented to prevent the infection of cats, other vertebrate hosts and people.
Subject(s)
Bacterial Infections/veterinary , Cat Diseases/epidemiology , Protozoan Infections, Animal/parasitology , Anaplasma/isolation & purification , Animals , Babesia/isolation & purification , Bacterial Infections/epidemiology , Bacterial Infections/microbiology , Bartonella/isolation & purification , Borrelia burgdorferi/isolation & purification , Cat Diseases/microbiology , Cat Diseases/parasitology , Cats , Ehrlichia/isolation & purification , Female , Leishmania infantum/isolation & purification , Male , Portugal/epidemiology , Protozoan Infections, Animal/epidemiologyABSTRACT
The aim of this study was to conduct a serological survey for Lyme diseases, brucellosis, leptospirosis and toxoplasmosis and identify the risk variables related to these zoonoses in humans living in the rural area of Jataizinho, state of Parana, Brazil. A total of 63 rural properties were surveyed. Additionally, 207 serum samples collected from these rural area inhabitants were tested for indirect immunofluorescence (IFI) and western blots (WB) were performed to detect Borrelia burgdorferi (sensu lato); a tamponated acidified antigen test (AAT) and 2-mercaptoethanol (2-ME) were used to detect antibodies of Brucella abortus; the microscopic agglutination test (MAT) was carried out to detect antibodies anti-Leptospira spp. and IFI was used to find antibodies of Toxoplasma gondii. Two of the samples (0.96%) were reactive for Lyme borreliosis, three (1.4%) for brucellosis, 25 (12.1%) for leptospirosis and 143 (69.1%) for toxoplasmosis. Although the town of Jataizinho has a human development index (IDH) that was considered to be average (0.733) in the state of Parana, the low social, economic and cultural conditions of the population from small rural properties have resulted in lack of basic information on animal health and direct or indirect contact with the various species of domestic animals, wildlife and ticks have probably contributed to the prevalence levels found. These results show the need for additional regional studies in order to determine the epidemiological characteristics of these diseases as well as their respective vectors and reservoirs so that effective prophylaxis can be administered in the human population.
ABSTRACT
The aim of this study was to investigate the presence of DNA of Borrelia burgdorferi sensu lato (s.l.) in ticks that feed on horses used for animal traction in rural Jataizinho, Parana, Brazil. Between February and June 2008, a total of 224 ticks was collected of which 75% were identified as Dermacentor nitens and 25% as Amblyomma cajenense. To amplify B. burgdorferi s.l. DNA, the intergenic space region (ISR) between the 5S (rrf) 23S (rrl) rRNA genes was used as targets for nested-PCR. Two ticks of the D. nitens species were positive for B. burgdorferi s.l. Both species showed a fragment of 184 bp, but the sequencing revealed 99.9% homology with the B. burgdorferi sensu stricto (s.s.) strain B31. These results showed, for the first time, the presence of spirochete DNA infecting ticks that parasitize horses used for animal traction, in the rural municipality mentioned. In conclusion, this study opens up promising prospects for determining the infection rate of B. burgdorferi s.s. genospecies or other species in the equine population, as well as the impact of the infection rate on Lyme disease in the state of Parana.