Optimization and comparative analysis of LAMP and PCR techniques for the detection of leptospiral DNA in Golden Syrian hamsters.

Leptospirosis is a zoonotic disease with significant public health and economic impact worldwide. Rapid and accurate diagnosis is essential for effective prevention and treatment. This study optimized a loop-mediated isothermal amplification (LAMP) assay using BFo isothermal DNA polymerase with different colorimetric indicators. LAMP was able to detect DNA from pathogenic and intermediate leptospires, while non-pathogenic leptospires and other non-leptospiral microorganisms were negative. LAMP assay combined with calcein showed a tenfold higher limit of detection (1 ng of leptospiral DNA per reaction) than LAMP combined with hydroxynaphthol blue or end-point PCR lipL32 (10 ng of DNA per reaction). Animal samples were collected from infected and non-infected Golden Syrian hamsters (Mesocricetus auratus) to evaluate and compare the performance of LAMP and PCR. These techniques showed a substantial agreement according to Cohen's kappa statistic, being both useful techniques for detecting leptospiral DNA in clinical samples. Overall, this study demonstrates that the LAMP assay is a sensitive, specific, rapid, and simple tool for the detection of leptospiral DNA. It has the potential to facilitate the diagnosis of leptospirosis, particularly in low-income regions with limited diagnosis resources.

First report of pathogenic Leptospira spp. in Tadaridabrasiliensis bats (family Molossidae) and Eptesicus furinalis (family Vespertilionidae) of Argentina. New host species in this country? / Primer reporte de Leptospira spp. patógena en murciélagos Tadaridabrasiliensis (familia: Molossidae) y Eptesicusfurinalis (familia: Vespertilionidae) en Argentina. ¿Nuevas especies hospedadoras en el país?

ABSTRACT Leptospirosis is an endemic disease caused byLeptospiraspp., a bacterium that affects animals and humans. In recent years, the number of reports of leptospirosis in wild animals has increased, which highlights the need to study the infectious agents in these animals. In this study, a duplex PCR for the detection of leptospiral DNA was performed on 50 kidney samples from bats, and a MAT (Microscopic Agglutination Test) for serological detection of anti-leptospiral antibodies was applied to 47 serum samples from bats from different regions of Buenos Aires Province, Argentina. DNA was extracted using Chelex-100 and duplex PCR was performed by targeting the detection of genessecYandflaB, of pathogenicLeptospiraspp. Of the 50 kidney samples, 3 were positive forEumopssp. andTadaridabrasiliensisby duplex PCR. Of the 47 serum samples, 12 were positive for different serovars:Leptospira interrogansserovars Icterohaemorrhagiae, Cynopteri and Bataviae, andLeptospira borgpeterseniiserovar Ballum. This is the first report of the detection of pathogenic leptospires by serology in bats belonging to theT. brasiliensisandEptesicus furinalisspecies in Argentina. In addition, this is the first report of the detection of pathogenic leptospiral DNA by PCR inT. brasiliensisspecies. The detection ofLeptospiraspp. in these wild animals shows that they may play an important role as wildlife reservoirs of leptospires.

RESUMEN La leptospirosis es una enfermedad endémica causada porLeptospiraspp., una bacteria que afecta a animales y a humanos. En los últimos años, el número de reportes de leptospirosis en animales silvestres ha aumentado, lo que resalta la necesidad de analizar los agentes infecciosos en estos animales. En este estudio, se aplicó una reacción en cadena de la polimerasa (PCR) dúplex para la identificación del ADN leptospiral en 50 muestras de riñones de murciélagos y la prueba de aglutinación microscópica (MAT) para la detección serológica de anticuerpos antileptospira en 47 muestras de suero de murciélagos de diferentes regiones de la provincia de Buenos Aires, Argentina. El ADN fue extraído usando Chelex-100 y la PCR dúplex estuvo dirigida a la detección de los genessecYyflaBdeLeptospiraspp. patógena. De las 50 muestras de riñón, tres resultaron positivas por PCR dúplex paraEumopssp. yTadaridabrasiliensis. De las 47 muestras de suero, 12 fueron positivas a diferentes serovares:LeptospirainterrogansserovaresIcterohaemorrhagiae, Cynopteri y Bataviae, yLeptospiraborgpeterseniiserovarBallum. Este es el primer reporte de detección de leptospiras patógenas por serología en murciélagos pertenecientes a las especiesT. brasiliensisyEptesicusfurinalisen Argentina. Además, también es el primero en la localización de ADN leptospiral por PCR en la especieT. brasiliensis.La identificación deLeptospiraspp. en estos animales silvestres muestra que pueden desempeñar un papel importante como reservorios de leptospiras en la fauna silvestre.

New enzyme-linked immunoassay for the detection of specific antibodies against multiple Leptospira serogroups in bovine sera.

Leptospirosis is a zoonotic disease with worldwide endemicity in Argentina, it is a significant public health problem in low-income populations. Bovine leptospirosis is a serious economic problem for cattle production, causing abortions, reduced milk yield, mortality in calves and decreased daily weight gain. We developed an enzyme-linked immunosorbent assay (ELISA) with sonicated Leptospira interrogans serogroup Icterohaemorrhagiae serovar Copenhageni M 20. We evaluated its performance for the detection of specific antibodies against multiple Leptospira serogroups in bovine. The microscopic agglutination test (MAT) was used as the gold standard. The performance of this ELISA was evaluated with a panel of sera (118 MAT confirmed positive and 97 MAT negative). The overall sensitivity was close to 85.6 % and the specificity was 83.5 %, according to the MAT reference method. Analytical specificity of the IgG-ELISA was evaluated using 50 bovine serum samples from animals showing serum antibodies against other pathogens that cause abortion in bovine, such as Brucella sp., Neospora sp. and Bovine Viral Diarrhea (BVD), and no cross-reaction was observed. This IgG-ELISA can be an alternative to the MAT for diagnosis of leptospiral infection in bovine.

First report of pathogenic Leptospira spp. in Tadarida brasiliensis bats (family Molossidae) and Eptesicus furinalis (family Vespertilionidae) of Argentina. New host species in this country?

Leptospirosis is an endemic disease caused by Leptospira spp., a bacterium that affects animals and humans. In recent years, the number of reports of leptospirosis in wild animals has increased, which highlights the need to study the infectious agents in these animals. In this study, a duplex PCR for the detection of leptospiral DNA was performed on 50 kidney samples from bats, and a MAT (Microscopic Agglutination Test) for serological detection of anti-leptospiral antibodies was applied to 47 serum samples from bats from different regions of Buenos Aires Province, Argentina. DNA was extracted using Chelex-100 and duplex PCR was performed by targeting the detection of genes secY and flaB, of pathogenic Leptospira spp. Of the 50 kidney samples, 3 were positive for Eumops sp. and Tadarida brasiliensis by duplex PCR. Of the 47 serum samples, 12 were positive for different serovars: Leptospira interrogans serovars Icterohaemorrhagiae, Cynopteri and Bataviae, and Leptospira borgpetersenii serovar Ballum. This is the first report of the detection of pathogenic leptospires by serology in bats belonging to the T. brasiliensis and Eptesicus furinalis species in Argentina. In addition, this is the first report of the detection of pathogenic leptospiral DNA by PCR in T. brasiliensis species. The detection of Leptospira spp. in these wild animals shows that they may play an important role as wildlife reservoirs of leptospires.

[Identification of new mutations in TCIRG1 as a cause of infantile malignant osteopetrosis in two Mexican patients]. / Identificación de nuevas mutaciones en TCIRG1 como causa de osteopetrosis maligna infantil en dos pacientes mexicanos.

BACKGROUND: Osteopetrosis is a heterogeneous group of diseases that are characterized by increased bone density due to abnormalities in osteoclast differentiation or function, which result in a lack of bone resorption. CASE REPORTS: Two patients with osteopetrosis onset since the first months of life, with facial dysmorphia, blindness, deafness, hepatosplenomegaly, hypotonia, neurodevelopmental retardation and bicytopenia. Bone radiographs showed osteosclerosis. They were assessed by different specialists prior to definitive diagnosis. Genetic analysis determined mutations in the TCIRG1 gene. Patient 1 had a homozygous mutation for p.Ile720Alafs*14 identified, which hasn't been previously reported. Patient 2 had a compound heterozygous mutation: the first one, p.Phe459Leufs*79, and the second one, p.Gly159Argfs*68, none of which has been previously reported as far as we know. CONCLUSION: The only therapeutic option for patients with osteopetrosis is hematopoietic stem cell transplantation (HSCT), which should be carried out in the course of the first 3 months of life, before neurological damage occurs. Although osteopetrosis diagnosis is relatively simple, it is delayed owing to the lack of clinical suspicion.

Antecedentes: La osteopetrosis es un grupo heterogéneo de enfermedades que se caracterizan por aumento de la densidad ósea debido a anomalías en la diferenciación o función de los osteoclastos, lo que se traduce en falta de reabsorción ósea. Reporte de casos: Dos pacientes con osteopetrosis quienes iniciaron su padecimiento desde los primeros meses de vida, con dismorfia facial, ceguera, sordera, hepatoesplenomegalia, hipotonía, retraso del neurodesarrollo y bicitopenia. Las radiografías óseas mostraron osteoesclerosis. Fueron valorados por diversos especialistas antes del diagnóstico definitivo. El análisis genético determinó mutaciones en el gen TCIRG1. En el paciente 1 se identificó una mutación homocigota para p.Ile720Alafs*14, la cual no ha sido reportada. En el paciente 2 se registró una mutación heterocigota compuesta: la primera p.Phe459Leufs*79 y la segunda p.Gly159Argfs*68, ninguna de las cuales han sido descritas hasta donde tenemos conocimiento. Conclusión: La única opción terapéutica de los pacientes con osteopetrosis es el trasplante de células progenitoras hematopoyéticas (TCPH), que se debe realizar en el transcurso de los primeros tres meses de vida, antes de que se origine daño neurológico. Si bien el diagnóstico de osteopetrosis es relativamente sencillo, se retrasa debido a la falta de sospecha clínica.

[Differentiation of pathogenic leptospires spp by PCR of ligB gene and sequencing]. / Diferenciación de serovares de leptospiras patógenas mediante PCR del gen ligB y secuenciación.

Leptospirosis is a zoonosis having worldwide distribution. The objective of this work was to develop a molecular technique to differentiate pathogenic Leptospira spp. A region of adhesin ligB, present only in the pathogenic species was amplified by PCR and sequenced. ligBRpet and ligBFpet primers were used, which amplified the target DNA from pathogenic L. interrogans reference strains serovars Pomona strain Pomona, Canicola strain Hond Utrecht IV, Copenhageni strain M 20, Wolffi strain 3705, Pyrogenes strain Salinem, Hardjo strain Hardjoprajitmo, L. borgpetersenii serovar Castellonis strain Castellon 3 and 4 pathogenic strains isolated from bovines, pigs, rats and opossums. L. biflexa serovars Patoc strain Patoc I and Andamana strain Andamana were not amplified. Sequencing of the amplified products exhibited sufficient variation among serovars, which differentiates them.

Isolation of a Seawater Tolerant Leptospira spp. from a Southern Right Whale (Eubalaena australis).

Leptospirosis is the most widespread zoonotic disease in the world. It is caused by pathogenic spirochetes of the genus Leptospira spp. and is maintained in nature through chronic renal infection of carrier animals. Rodents and other small mammals are the main reservoirs. Information on leptospirosis in marine mammals is scarce; however, cases of leptospirosis have been documented in pinniped populations from the Pacific coast of North America from southern California to British Columbia. We report the isolation of a Leptospira spp. strain, here named Manara, from a kidney sample obtained from a Southern Right Whale (Eubalaena australis) calf, which stranded dead in Playa Manara, Península Valdés, Argentina. This strain showed motility and morphology typical of the genus Leptospira spp. under dark-field microscopy; and grew in Ellinghausen-McCullough-Johnson-Harris (EMJH) medium and Fletcher medium after 90 days of incubation at 28°C. Considering the source of this bacterium, we tested its ability to grow in Fletcher medium diluted with seawater at different percentages (1%, 3%, 5%, 7% and 10% v/v). Bacterial growth was detected 48 h after inoculation of Fletcher medium supplemented with 5% sea water, demonstrating the halophilic nature of the strain Manara. Phylogenetic analysis of 16S rRNA gene sequences placed this novel strain within the radiation of the pathogenic species of the genus Leptospira spp., with sequence similarities within the range 97-100%, and closely related to L. interrogans. Two different PCR protocols targeting genus-specific pathogenic genes (G1-G2, B64I-B64II and LigB) gave positive results, which indicates that the strain Manara is likely pathogenic. Further studies are needed to confirm this possibility as well as determine its serogroup. These results could modify our understanding of the epidemiology of this zoonosis. Until now, the resistance and ability to grow in seawater for long periods of time had been proven for the strain Muggia of L. biflexa, a saprophytic species. To the best of our knowledge, this is the first isolation of a Leptospira sp. from cetaceans. Our phenotypic data indicate that strain Manara represents a novel species of the genus Leptospira, for which the name Leptospira brihuegai sp. nov. is proposed.

[Morphological and molecular identification of Cysticercus fasciolaris isolated from rodent hosts (Rattus norvegicus) in Buenos Aires province (Argentina)]. / Identificación morfológica y molecular de Cysticercus fasciolaris aislado de un roedor (Rattus norvegicus) de la provincia de Buenos Aires (Argentina).

In a rodent (Rattus norvegicus) survey in Buenos Aires province, metacestodes of tapeworms were found encysted in the liver of the host. The aim of this work was the morphological and molecular identification of this parasite. To achieve the molecular characterization of the parasite, ribosomal (28S) and mitochondrial (COI) DNA were amplified and sequenced. Based on both morphological and molecular data using bioinformatic tools, the metacestode was identified as Cysticercus fasciolaris. The adult form of this tapeworm (Taenia taeniaeformis) commonly infects felid and canid mammalian hosts. This is the first report on the molecular identification of Cysticercus fasciolaris in Buenos Aires province (Argentina).

Identificación morfológica y molecular de Cysticercus fasciolaris aislado de un roedor (Rattus norvegicus) de la provincia de Buenos Aires (Argentina) / [Morphological and molecular identification of Cysticercus fasciolaris isolated from rodent hosts (Rattus norvegicus) in Buenos Aires province (Argentina)].

In a rodent (Rattus norvegicus) survey in Buenos Aires province, metacestodes of tapeworms were found encysted in the liver of the host. The aim of this work was the morphological and molecular identification of this parasite. To achieve the molecular characterization of the parasite, ribosomal (28S) and mitochondrial (COI) DNA were amplified and sequenced. Based on both morphological and molecular data using bioinformatic tools, the metacestode was identified as Cysticercus fasciolaris. The adult form of this tapeworm (Taenia taeniaeformis) commonly infects felid and canid mammalian hosts. This is the first report on the molecular identification of Cysticercus fasciolaris in Buenos Aires province (Argentina).

Identificación morfológica y molecular de Cysticercus fasciolaris aislado de un roedor (Rattus norvegicus) de la provincia de Buenos Aires (Argentina). / [Morphological and molecular identification of Cysticercus fasciolaris isolated from rodent hosts (Rattus norvegicus) in Buenos Aires province (Argentina)].

In a rodent (Rattus norvegicus) survey in Buenos Aires province, metacestodes of tapeworms were found encysted in the liver of the host. The aim of this work was the morphological and molecular identification of this parasite. To achieve the molecular characterization of the parasite, ribosomal (28S) and mitochondrial (COI) DNA were amplified and sequenced. Based on both morphological and molecular data using bioinformatic tools, the metacestode was identified as Cysticercus fasciolaris. The adult form of this tapeworm (Taenia taeniaeformis) commonly infects felid and canid mammalian hosts. This is the first report on the molecular identification of Cysticercus fasciolaris in Buenos Aires province (Argentina).