New molecular target for the phylogenetic identification of Leptospira species directly from clinical samples: an alternative gene to 16S rRNA

Abstract INTRODUCTION: Phylogenetic analysis of the 16S ribosomal gene initial region is used to identify Leptospira isolates at the species level from clinical samples. Unfortunately, this method cannot differentiate between some intermediates and saprophytic species. METHODS: We used comparative genomic analysis between 35 Leptospira species to find new molecular targets for Leptospira species identification. RESULTS: We proposed the use of the rpoC gene, encoding the DNA-directed RNA polymerase β-subunit, for identifying 35 Leptospira species. CONCLUSIONS: The rpoC gene can be a molecular target to identify the main species of the Leptospira genus directly from clinical samples.

Caracterización epidemiológica de la infección por Leptospira spp. en caballos de trabajo y en personas ocupacionalmente expuestas en seis unidades de la Policía Nacional de Colombia / Epidemiological characterization of Leptospira spp. infection in working horses and in an occupationally exposed population in six Colombian police stations

Resumen Introducción. Los caballos de trabajo de la Policía Nacional tienen un estrecho contacto con sus manejadores y la población en general durante las actividades recreativas y de patrullaje, lo cual puede favorecer la transmisión de la leptospirosis en los caballos y el personal ocupacionalmente expuesto. Objetivo. Caracterizar epidemiológicamente la leptospirosis mediante pruebas de serología, urocultivo y reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) en caballos de trabajo y personal con riesgo ocupacional pertenecientes a seis unidades de la Policía Nacional de Colombia. Materiales y métodos. Se evaluaron 153 caballos machos castrados y 123 personas en las seis unidades en los municipios de Manizales, Pereira, Armenia, Ibagué, Tuluá y Cali. Se utilizaron tres formatos estructurados para recabar información y se obtuvieron muestras sanguíneas de las personas y de los caballos, las cuales se procesaron con la prueba de aglutinación microscópica (Macroscopic Agglutination Test, MAT) para 24 serogrupos. Se practicó el examen clínico de los caballos y se obtuvieron muestras de orina para el urocultivo y la PCR convencional. Resultados. La seroprevalencia de Leptospira spp. fue de 3,25 % (n=4) en las personas y de 85 % (n=130) en los caballos. Entre los caballos, los serogrupos Djasiman y Shermani fueron los más prevalentes. El urocultivo fue positivo en el 64,7 % (99/153) de las muestras, en tanto que los análisis de PCR fueron negativos. Se encontró una asociación estadísticamente significativa de la frecuencia de salida de las instalaciones (p=0,009) y la presencia de fauna silvestre (p=0,051) con la infección por el serogrupo Shermani. Conclusión. Las características epidemiológicas de la leptospirosis en los caballos sugieren una presentación endémica de la infección y su papel como reservorios de la bacteria; sin embargo, debe dilucidarse la patogenia de la enfermedad con estudios complementarios.

Abstract Introduction: Police working horses are in close contact with their managers and the general population during recreational and patrol activities, which can favor the transmission of leptospirosis among the horses and the occupationally exposed personnel. Objective. To characterize epidemiologically leptospirosis through serology, urine culture and PCR in working horses and in the occupationally exposed population in six police stations in Colombia. Materials and methods. We tested 153 castrated male horses and 123 people in six police stations in the municipalities of Manizales, Pereira, Armenia, Ibagué, Tuluá, and Cali. Three structured formats were applied and blood samples were obtained from people and horses, which were processed with the Macroscopic Agglutination Test, (MAT) for 24 serogroups. Horses were subject to a clinical examination, and urine samples were obtained for urine culture and conventional PCR. Results. The seroprevalence of human Leptospira spp. was 3.25% (n=4) while in horses it was 85% (n=130). Among the horses, serogroups Djasiman and Shermani were the most prevalent. The urine culture was positive in 64.7% (99/153) of the samples, whereas PCR analyzes were negative. A statistically significant association was found between the frequency of exiting the facilities (p=0.009) and the presence of wildlife (p=0.0051) with the infection by serogroup Shermani. Conclusion. The epidemiological characteristics of leptospirosis in horses suggest an endemic presentation of the infection and its role as reservoirs of the bacteria; however, it is necessary to elucidate the pathogenesis of the disease with complementary studies.

Identification of pathogenic and nonpathogenic Leptospira species of Brazilian isolates by Matrix Assisted Laser Desorption/Ionization and Time Flight mass spectrometry

ABSTRACT Matrix Assisted Laser Desorption/Ionization and Time of Flight mass spectrometry (MALDI-TOF MS) is a powerful tool for the identification of bacteria through the detection and analysis of their proteins or fragments derived from ribosomes. Slight sequence variations in conserved ribosomal proteins distinguish microorganisms at the subspecies and strain levels. Characterization of Leptospira spp. by 16S RNA sequencing is costly and time-consuming, and recent studies have shown that closely related species (e.g., Leptospira interrogans and Leptospira kirschneri) may not be discriminated using this technology. Herein, we report an in-house Leptospira reference spectra database using Leptospira reference strains that were validated with a collection of well-identified Brazilian isolates kept in the Bacterial Zoonosis Laboratory at the Veterinary Preventive Medicine and Animal Health Department at Sao Paulo University. In addition, L. interrogans and L. kirschneri were differentiated using an in-depth mass spectrometry analysis with ClinProTools™ software. In conclusion, our in-house reference spectra database has the necessary accuracy to differentiate pathogenic and non-pathogenic species and to distinguish L. interrogans and L. kirschneri.

Serological and molecular detection of leptospira spp in dogs

Abstract INTRODUCTION: This study aimed to detect anti-Leptospira spp antibodies and Leptospira DNA in domestic dogs. METHODS: Blood and urine from 106 dogs were evaluated by microscopic agglutination test (MAT) and polymerase chain reaction (PCR), respectively. RESULTS: Six (5.7%) and one (1%) animals were positive by MAT and PCR, respectively. CONCLUSIONS: These results show a low prevalence of infection by Leptospira spp. The absence of positive results for the Icterohaemorrhagiae serogroup indicates the small relevance of these dogs as sources of human leptospirosis.

Genome of Leptospira borgpetersenii strain 4E, a highly virulent isolate obtained from Mus musculus in southern Brazil

A previous study by our group reported the isolation and characterisation of Leptospira borgpetersenii serogroup Ballum strain 4E. This strain is of particular interest because it is highly virulent in the hamster model. In this study, we performed whole-genome shotgun genome sequencing of the strain using the SOLiD sequencing platform. By assembling and analysing the new genome, we were able to identify novel features that have been previously overlooked in genome annotations of other strains belonging to the same species.

Genomic characterisation of Leptospira inadai serogroup Lyme isolated from captured rat in Brazil and comparative analysis with human reference strain

Leptospira inadai is classified as a species of the Leptospira intermediate group that has been poorly studied due to its apparent insignificance to human and animal health. Nevertheless, over the last two decades the species has been described in human cases in India and in carrier animals in Ecuador. Here, we present the first identification and genomic characterisation of L. inadai serogroup Lyme isolated from captured rodent in Brazil. Even though the M34/99 strain was not pathogenic for hamsters, it was able to establish renal colonisation. The M34/99 strain presented high similarity with L. inadai serogroup Lyme human reference indicating that animal strain could also infect humans, although it does not represent high risk of severe disease. An extrachromosomal sequence was also identified in M34/99 strain and presented high identity with previously described L. inadai phage LinZ_10, suggesting that phage-like extrachromosomal sequence may be another feature of this understudied species.

Human leptospirosis: occurrence of serovars of Leptospira spp. in the state of Minas Gerais, Brazil, from 2008 to 2012

Abstract Background: Leptospirosis is an infectious and acute disease caused by Leptospira spp. that have high epidemic potential. This study verified the main Leptospira spp. serovars detected by MAT from serum of patients with suspicion of leptospirosis from 2008 to 2012 in Minas Gerais State. Methods: The laboratory received sera from 4654 patients. All serum were screened by IgM-ELISA according to the manufacturer's instructions. Each sample reactive or indeterminate were tested against twenty-four serovars of Leptospira by MAT. Results: In this study, 597 patients were classified as reactive on MAT. Only 301 patients were confirmed by laboratory test. It was not possible confirmation by laboratory diagnosis of 296 patients. Among the samples classified as reactive on MAT, 273 patients exhibited titers bigger than 800 for one or more serovars; seroconversion was detected in 28 cases. Percentage of 85.1% of the samples reactive on MAT corresponded to males, 39.4% corresponded to patients aged between 20 and 39 years old. The most common serovars found were Icterohaemorrhagiae, Andamana, Patoc, Tarassovi, Copenhageni, Hardjo and Australis. Concerning the samples that exhibited titers bigger than 800, serovar Icterohaemorrhagiae was also the most common, followed by Copenhageni, Andamana, Patoc, Tarassovi, Grippotyphosa and Canicola. In this study, 40% of the cases occurred to the metropolitan area, state capital and 34 neighboring towns. Conclusion: Our results show the possibly spreading serovars in Minas Gerais State and contribute to knowledge of human leptospirosis, aiming at improving the prevention, control of the disease, as well as the treatment of infected patients.

Molecular and serological characterization of Leptospira kirschneri serogroup Pomona isolated from a human case in a Brazilian rural area

Abstract INTRODUCTION: Leptospirosis is an important health concern in Brazil. Currently, information on the epidemiology of the disease in the rural areas of the country is lacking. METHODS: Serological and molecular techniques were used to characterize a clinical isolate of Leptospira. RESULTS: The strain CLEP 00060, isolated from a 59-year-old man in a rural area of Rio Grande do Sul state, Brazil, was identified as belonging to L. kirschneri serogroup Pomona serovar Mozdok. CONCLUSIONS: This study contributes to the local epidemiological knowledge of leptospirosis, prevention of the disease by vaccines, and improvements in its diagnosis.

A duplex endpoint PCR assay for rapid detection and differentiation of leptospira strains

Abstract INTRODUCTION: This study aimed to develop a duplex endpoint PCR assay for rapid detection and differentiation of Leptospira strains. METHODS: Primers were designed to target the rrs (LG1/LG2) and ligB (LP1/LP2) genes to confirm the presence of the Leptospira genus and the pathogenic species, respectively. RESULTS: The assay showed 100% specificity against 17 Leptospira strains with a limit of detection of 23.1pg/µl of leptospiral DNA and sensitivity of 103 leptospires/ml in both spiked urine and water. CONCLUSIONS: Our duplex endpoint PCR assay is suitable for rapid early detection of Leptospira with high sensitivity and specificity.

Genetic diversity of Leptospira in northwestern Colombia: first report of Leptospira santarosai as a recognised leptospirosis agent

The region of Antioquia in northeastern Colombia has the highest number of reported leptospirosis cases in the country. It also shows high seroprevalence indexes in the general population and socio-environmental conditions favourable for the transmission of the disease between humans and animals. In this study, 25 Leptospira isolates from Colombia’s Antioquia department were identified to the species level as L. santarosai (12), L. interrogans (9) and L. meyeri (4) using phylogenetic analysis of the Amidohydrolase gene. Typing at the serovar level was performed using multilocus sequence typing (MLST) and monoclonal antibodies. The serovars Canalzonae, Babudieri, Alice, Beye, and Copenhageni have been identified as causing human or animal infections in Antioquia, Colombia. The four environmental isolates were not identified to the serovar level. L. santarosai serovar Canalzonae and Alice were identified as new etiologic agents of human leptospirosis in Antioquia, Colombia. This paper reports species and serovars that were previously unknown in the region.

Evaluación de un panel reducido de cepas de leptospiras para el diagnóstico en humanos por microaglutinación (MAT) / Evaluation of a reduced panel of leptospira strains for microagglutination

Objetivo. Evaluar si el uso del panel de 19 cepas de leptospiras, sugerido por la Sociedad Internacional de Leptospirosis para la microaglutinación (MAT, por sus siglas en inglés), permite mayor confirmación de casos que el de 12 cepas. Material y métodos. Estudio observacional de corte transversal. Se estudiaron 441 muestras de sueros de pacientes de Argentina, derivadas para el diagnóstico de leptospirosis en los periodos de julio de 2009 a diciembre de 2010 y enero a octubre de 2013. Resultados. Se obtuvo el mismo resultado con el panel reducido que con el ampliado. En seis casos resultó presumiblemente infectante algún serovar del panel ampliado, aunque siempre coaglutinando con cepas del reducido. Conclusión. En Argentina, el diagnóstico de leptospirosis por MAT podría continuar realizándose con el panel reducido, lo que reduciría el costo y tiempo de diagnóstico. La información adicional que aportaría el panel ampliado está relacionada con la epidemiología, mediante un mejor conocimiento del serogrupo presumiblemente infectante.

Objective. To evaluate if the use of the 19 Leptospira strains panel suggested by the International Leptospirosis Society of World Health Organization for microagglutination allows confirmation of more cases that the 12 strains panel used in Argentina. Materials and methods. Cross-sectional observational study. We studied 441 serum samples corresponding to Argentinean patients with suspected leptospirosis derived during from July to December, 2009 and from January to October, 2013. Results. The same number of positive samples was obtained using the MAT with the 19 or 12 strains. In six cases a serovar of the expanded collection was presumably infecting, but always coagglutinated with strains of the reduced panel. Conclusion. In Argentina, the diagnosis of leptospirosis by MAT could be made using the reduced 12 strains panel, obtaining the same result in case detection as using the 19 strains panel. Additional information provided by the use of all strains could be the presumably infecting serogroup.

Molecular characterisation and disease severity of leptospirosis in Sri Lanka

Leptospirosis is a re-emerging zoonotic disease all over the world, important in tropical and subtropical areas. A majority of leptospirosis infected patients present as subclinical or mild disease while 5-10% may develop severe infection requiring hospitalisation and critical care. It is possible that several factors, such as the infecting serovar, level of leptospiraemia, host genetic factors and host immune response, may be important in predisposition towards severe disease. Different Leptospira strains circulate in different geographical regions contributing to variable disease severity. Therefore, it is important to investigate the circulating strains at geographical locations during each outbreak for epidemiological studies and to support the clinical management of the patients. In this study immunochromatography, microscopic agglutination test and polymerase chain reaction were used to diagnose leptospirosis. Further restriction fragment length polymorphism and DNA sequencing methods were used to identify the circulating strains in two selected geographical regions of Sri Lanka. Leptospira interrogans, Leptospira borgpetersenii and Leptospira kirschneri strains were identified to be circulating in western and southern provinces. L. interrogans was the predominant species circulating in western and southern provinces in 2013 and its presence was mainly associated with renal failure.

Identification of Leptospira serovars by RFLP of the RNA polymerase beta subunit gene (rpoB)

Leptospires are usually classified by methods based on DNA-DNA hybridization and the conventional cross-agglutination absorption test, which uses polyclonal antibodies against lipopolysaccharides. In this study, the amplification of the rpoB gene, which encodes the beta-subunit of RNA polymerase, was used as an alternative tool to identify Leptospira. DNA extracts from sixty-eight serovars were obtained, and the hypervariable region located between 1990 and 2500-bp in the rpoB gene was amplified by polymerase chain reaction (PCR). The 600-bp amplicons of the rpoB gene were digested with the restriction endonucleases TaqI, Tru1I, Sau3AI and MslI, and the restriction fragments were separated by 6% polyacrylamide gel electrophoresis. Thirty-five fragment patters were obtained from the combined data of restriction fragment length polymorphism (PCR-RFLP) analysis and used to infer the phylogenetic relationships among the Leptospira species and serovars. The species assignments obtained were in full agreement with the established taxonomic classifications. Twenty-two serovars were effectively identified based on differences in their molecular profiles. However, the other 46 serovars remained clustered in groups that included more than one serovar of different species. This study demonstrates the value of RFLP analysis of PCR-amplified rpoB as an initial method for identifying Leptospira species and serovars.

Molecular characterization of the first leptospires isolated from goats in Brazil

Two Leptospira sp. isolates were obtained by the first time from goats in Brazil and characterized by sequencing rrs, rpoB and secY genes, PFGE and typing with monoclonal antibodies. Both isolates are identical and belong to Leptospira santarosai. Analysis of the rrs and the rpoB genes sequences revealed 100% identity between the goat isolates and the Bananal reference strain. When secY sequences of the two isolates were compared to each other, it was observed that they had identical sequences. However, when compared to that of the Bananal reference strain, there were 15 mismatches along the 549 bp secY sequence. In conclusion, molecular methods are increasingly useful for the characterization of leptospires and allowed to identify those isolates of caprine origin as closely related but not identical to serovar Bananal, and constitute a new type named Carioca.

Genotipificación y evaluación de la dinámica de infección de un aislamiento colombiano de Leptospira santarosai en el modelo experimental en hámster / Genotyping and evaluation of infection dynamics in a Colombian isolate of Leptospira santarosai in hamster as an experimental model

Introducción. Es necesario desarrollar modelos de estudio de la leptospirosis. Objetivo. Genotipificar un aislamiento de Leptospira proveniente de una persona con síndrome de Weil y evaluar, con el modelo experimental en Mesocricetus auratus , su dinámica de infección. Materiales y métodos. Se hizo la genotipificación por análisis de las secuencias génicas rrs 16S y lipL32 . Se determinó la dosis letal media en hámster inoculada por vía intraperitoneal. Se identificaron los patrones de química clínica, la duración de la leptospiremia, la leptospiruria y la histopatología, comparados con el mismo modelo inoculado con la cepa de Leptospira interrogans (Fiocruz L1-130). Resultados. Mediante análisis molecular se determinó que el aislamiento correspondía a la especie patógena Leptospira santarosai . La bacteria se recuperó a partir de tejido de riñón y de pulmón, y se detectó por medio de PCR lipL32 en el tercer día después de la infección. La proteína C reactiva aumentó en el quinto día después de la infección (3,25 mg/dl; valor normal: 0,3 mg/dl) con una disminución en el día 18 (2,60 mg/dl; valor normal: 0,8 mg/dl). Los biomarcadores de urea mostraron alteraciones indicativas de falla renal aguda (día 5 después de la infección: 49,01 mg/dl y día 18: 53,71 mg/dl). La histopatología mostró neumonía intersticial con diferentes grados de hemorragia, así como nefritis intersticial. Conclusión. Se identificó la presencia de la especie L. santarosai con capacidad patógena comparable con la cepa Fiocruz L1-130 de L. interrogans , de reconocida virulencia y tropismo pulmonar, en cuanto a los aspectos histopatológicos de tropismo a pulmón y riñón. Nunca antes se había evaluado en un modelo experimental un aislamiento de origen local bajo estos criterios biológicos.

Introduction: Is necessary to develop models for the study of leptospirosis. Objective: To genotype a Colombian strain of Leptospira isolated from a human with Weil´s syndrome and to evaluate its infection dynamics in the hamster experimental model. Materials and methods: Genotyping was performed by amplification and sequence analysis of the rrs 16S and lipL32 genes. The median lethal dose was determined in intraperitoneally inoculated hamsters. The patterns of clinical chemistry, the duration of leptospiremia, leptospiruria and pathological findings were studied and compared in the same animal model infected with L. interrogans (Fiocruz L1-130). Results: Molecular typing revealed that the isolate corresponded to the pathogenic species L. santarosai, which was recovered from hamsters´ kidneys and lungs and detected by lipL32 PCR from day 3 post-infection in these organs. There was a marked increase of C-reactive protein in animals at day 5 post-infection (3.25 mg/dl; normal value: 0.3 mg/dl) with decreases by day 18 (2.60 mg/dl: normal value: 0.8 mg/dl). Biomarkers of urea showed changes consistent with possible renal acute failure (day 5 post-infection: 49.01 mg/dl and day 18 post-infection: 53.71 mg/dl). Histopathological changes included interstitial pneumonia with varying degrees of hemorrhage and interstitial nephritis. Conclusion: The pathogenic species L. santarosai was identified in Colombia. Its pathogenicity as determined by tropism to lung and kidney was comparable to that of L. interrogans Fiocruz L1-130, well known for its virulence and pulmonar tropism. The biological aspects studied here had never before been evaluated in an autochthonous isolate.

Genotypes of pathogenic Leptospira spp isolated from rodents in Argentina

Leptospirosis is the most widespread zoonosis in the world and significant efforts have been made to determine and classify pathogenic Leptospira strains. This zoonosis is maintained in nature through chronic renal infections of carrier animals, with rodents and other small mammals serving as the most important reservoirs. Additionally, domestic animals, such as livestock and dogs, are significant sources of human infection. In this study, a multiple-locus variable-number tandem repeat analysis (MLVA) was applied to genotype 22 pathogenic Leptospira strains isolated from urban and periurban rodent populations from different regions of Argentina. Three MLVA profiles were identified in strains belonging to the species Leptospira interrogans (serovars Icterohaemorrhagiae and Canicola); one profile was observed in serovar Icterohaemorrhagiae and two MLVA profiles were observed in isolates of serovars Canicola and Portlandvere. All strains belonging to Leptospira borgpetersenii serovar Castellonis exhibited the same MLVA profile. Four different genotypes were isolated from urban populations of rodents, including both mice and rats and two different genotypes were isolated from periurban populations.

Frequência de anticorpos anti-Leptospira spp. Em cães atendidos no hospital veterinário da Universidade Estadual Do Norte Do Paraná - UENP / Frequency of antibodies anti- Leptospira spp. In dogs treated at the veterinary hospital of Northern Paraná State University - UENP / Frecuencia de anticuerpos anti- Leptospira spp. En perros tratados en el hospital veterinario de la Universidad Estadual Del Norte De Paraná - UENP

A leptospirose é uma enfermidade bacteriana causada por espécies patogênicas do gênero Leptospira. Os roedores são considerados como principal reservatório, mas o cão, assim como outros animais domésticos, pode desenvolver a doença e se tornar carreadores assintomáticos. O objetivo desse trabalho foi conhecer a frequência de aglutininas anti-Leptospira spp. em cães atendidos no Hospital Veterinário da Universidade Estadual do Norte do Paraná (UENP), no município de Bandeirantes-Paraná. Foram testados, pela prova de soroaglutinação microscópica (SAM), 70 cães adultos assintomáticos para leptospirose, 27 machos e 43 fêmeas, de diferentes raças e idades. A frequência de animais positivos foi de 26,47%, 33,33% dos machos e 25,58% das fêmeas. Os sorovares Canicola (33,33%) e Autumnalis (27,78%) foram os mais frequentes, seguidos pelo Icterohaemorrhagiae (11%) e Grippotyphosa (11%). Conclui-se que a bactéria Leptospira está circulante em animais assintomáticos, podendo dispersar a doença para outros animais e inclusive para o homem...

Leptospirosis is a bacterial disease caused by pathogenic species of Leptospira. Rodents are considered the main reservoir, but dogs and other domestic animals may develop the disease and become asymptomatic carriers. The aim of this study was to determine the frequency of anti-Leptospira spp. agglutinins in dogs examined at the Veterinary Hospital of the Northern Paraná State University in Bandeirantes, Paraná, Brazil. A total of 70 asymptomatic adult dogs (27 male and 43 female), of different breeds and ages, were tested for leptospirosis by microscopic agglutination test. The frequency of positive animals was 26.47%, with 33.33% males and 25.58% females. Canicola (33.33%) and Autumnalis (27.78%) were the most frequent serovars, followed by Icterohaemorrhagiae (11%) and Grippotyphosa (11%). The authors concluded that the Leptospira bacterium is circulating in asymptomatic animals and can spread the disease to other animals and even to human beings...

La leptospirosis es una enfermedad bacteriana causada por especies patógenas del género Leptospira. Los roedores son considerados como reservorio principal, pero en el perro, así como otros animales domésticos, la enfermedad puede desarrollarse y convertirse en portadores asintomáticos. El objetivo de este estudio ha sido determinar la frecuencia de aglutininas anti-Leptospira spp. en perros atendidos en el Hospital Veterinario de la Universidad Estadual del Norte de Paraná (UENP), en el municipio de Bandeirantes-Paraná. Se realizó la prueba de suero aglutinación microscópica (SAM), en 70 perros adultos asintomáticos para leptospirosis, 27 machos y 43 hembras, de diferentes razas y edades. La frecuencia de animales positivos fue de 26,47%, 33,33% machos y 25,58% hembras. Los serovares Canicola (33,33%) y Autumnalis (27.78%) fueron los más frecuentes, seguidos por Icterohaemorrhagiae (11%) y Grippotyphosa (11%). Llegamos a la conclusión de que la bacteria Leptospira está circulante en animales asintomáticos, pudiendo dispersar la enfermedad a otros animales e incluso a los seres humanos...

Comportamiento de la vigilancia epidemiológica de la leptospirosis humana en Colombia, 2007-2011 / Epidemiological surveillance of human leptospirosis in Colombia, 2007-2011

Introducción. La leptospirosis es una zoonosis reemergente de distribución mundial causada por una espiroqueta del género Leptospira. Durante los últimos años en Colombia aumentó el número de casos en humanos y animales. Objetivo. Caracterizar epidemiológicamente los casos de leptospirosis notificados al Sistema Nacional de Vigilancia en Salud Pública de Colombia y hacer una aproximación para conocer los serogrupos que circulan en el país. Materiales y métodos. Se diseñó un estudio observacional de corte retrospectivo, con registros del proceso de vigilancia de los casos reportados por el software Sivigila y muestras enviadas al Grupo de Microbiología de la Red Nacional de Laboratorios, durante el periodo 2007 a 2011. Se registraron variables de tipo sociodemográficas y se analizaron 17 serogrupos de Leptospira . En el análisis se utilizaron medidas de frecuencia, tendencia central y dispersión. Resultados. Se procesaron 11.786 registros, confirmándose 4.621 casos de leptospirosis. Las entidades territoriales con mayor registro fueron Valle del Cauca, Antioquia, Risaralda, Atlántico y Barranquilla; y las de incidencia más alta fueron Guaviare, Risaralda, San Andrés, Santa Marta y Barranquilla. El mayor número de casos reportados perteneció al área urbana, con mayor frecuencia de hombres (77 %), estudiantes (19,4 %) y amas de casas (13,6 %), con una mediana por edad de 29 años (rango intercuartílico: 45-19). Se evidenció la circulación de 17 serogrupos en el país; los más frecuentes fueron Australis (24,89 %), Hebdomadis (9,33 %) y Sejroe (8,0 %). Conclusión. En Colombia se ha mejorado la notificación y clasificación final de los casos, lo que ha permitido identificar al serogrupo Australis como el de mayor circulación.

Introduction: Leptospirosis is a reemerging zoonosis of worldwide distribution, caused by a spirochete of the genus Leptospira . In Colombia, the disease represents a major public health issue, and there has been an increased number of cases in humans and animals. Objective: To characterize epidemiologically cases of leptospirosis reported to the National Public Health Surveillance in Colombia, and to make an approach to determine the serogroups circulating in the country. Materials and methods: A retrospective observational study was designed using a process of monitoring records, which included cases reported by the software SIVIGILA and samples sent to the Microbiology Group of the National Laboratory Network (GM-RNL), for the period 2007-2011. We registered socio-demographic variables and analyzed 17 serogroups of Leptospira . Results: A total of 11,786 records were processed, with 4,621 confirmed cases of leptospirosis. The geographic places which reported the highest number of cases were: Valle del Cauca, Antioquia, Risaralda, Atlántico and Barranquilla, and those with the highest incidence were Guaviare, Risaralda, San Andres, Santa Marta and Barranquilla. The largest number of cases was from urban areas, and more commonly in men (77%), students (19.4%) and housewives (13.6%). A median age of 29 years (IQR 45-19) was observed. There was evidence of 17 serogroups circulating in the country, from which the three most frequent were Australis (24.89%), Hebdomadis (9.33%) and Sejroe (8.0%). Conclusions: In Colombia, the reported cases have improved as well as their final classification, allowing us to determine the Australis serogroup as the most widely circulating one.

Molecular serovar characterization of Leptospira isolates from animals and water in Colombia / Caracterización molecular de serovariedades de Leptospira spp. aisladas de muestras de animales y agua en Colombia

Introduction: Leptospirosis is a bacterial disease transmitted directly or indirectly from animals to humans that may result in severe hemorrhagic, hepatic/renal and pulmonary disease. There are 20 known Leptospira species and hundreds of serovars, some of which belong to different species. It is essential to identify pathogenic Leptospira serovars and their potential reservoirs to prepare adequate control strategies. Objective: To characterize the Leptospira serovars isolated from rodents, dogs, pigs and water samples in Colombia. Materials and methods: Leptospira organisms were isolated and cultured, and pathogenic strains were identified using a polymerase chain-reaction (PCR). Leptospira DNA and Salmonella Braenderup H9812 (molecular weight standard) DNA were cleaved using NotI and subjected to pulsed-field gel electrophoresis (PFGE). The PFGE patterns were analyzed based on bacterial strain-typing criteria and Dice coefficients (DCs) between these isolates and over 200 Leptospira organisms isolated from other parts of the world. Results: All of the isolates were pathogenic strains, and five were genetically characterized. The P275 (84% DC) and P282 (95% DC) pig isolates were related to the Leptospira interrogans Pomona serovar; the I15 (DC: 100%) rat isolate was identical to the Leptospira interrogans Icterohameorrhagiae or Copenhageni serovars, while the C67 (64% DC) dog and A42 (60% DC) water isolates were not related (< 73.7% DC) to any of the 200 reference serovars; the closest serovars were the Leptospira noguchii Nicaragua and Orleans serovars, respectively. Conclusion: This was the first molecular characterization of Colombian Leptospira spp isolates; these isolates will be used to develop a Colombian diagnostic panel.

Introducción. La leptospirosis es una infección bacteriana transmitida directa o indirectamente de animales a humanos, la cual puede resultar en una enfermedad hemorrágica grave, hepática o renal y pulmonar. Hay 20 especies de Leptospira conocidas y cientos de serovariedades, algunas de las cuales pertenecen a diferentes especies. Es esencial identificar las serovariedades patógenas y sus reservorios potenciales para enfocar estrategias de control. Objetivo. Caracterizar las serovariedades de Leptospira aisladas de muestras de roedores, perros, cerdos y agua en Colombia. Materiales y métodos. Las cepas de leptospiras aisladas fueron identificadas como patógenas usando la reacción en cadena de la polimerasa (PRC). Sus ADN y el ADN de Salmonella Braenderup H9812 (marcador de peso molecular) fueron cortados con NotI y corridos en electroforesis de campo pulsado. Los patrones de la ECP se analizaron con base en los criterios de tipificación para cepas bacterianas y el coeficiente de Dice, cuando se compararon con 200 cepas aisladas en otras partes del mundo. Los perfiles de ADN con un coeficiente de Dice entre 73,7 % y 100 % se consideraron pertenecientes a la misma especie. Resultados. Todos los aislamientos fueron cepas patógenas y cinco se caracterizaron genéticamente. El aislamiento P275 (coeficiente de Dice: 84 %) y el P282 (coeficiente de Dice: 95 %) de cerdos, se relacionaron con Leptospira interrogans de serovariedad Pomona; el aislamiento de rata (I15) fue indistinguible de Leptospira interrogans de serovariedades Icterohaemorrhagiae o Copenhageni (coeficiente de Dice: 100 %), mientras que los aislamientos de perro (C67) y agua (A42) no se relacionaron (coeficiente de Dice <73,7 %) con ninguna de las 200 cepas de referencia; las más cercanas fueron Leptospira noguchii de serovariedades Nicaragua (coeficiente de Dice: 63 %) y Orleans (coeficiente de Dice: 60 %). Conclusiones. Esta fue la primera caracterización molecular de serotipos de aislamientos colombianos, los cuales serían los primeros miembros de un panel diagnóstico colombiano.

Haemoglobin and red cell counts in leptospirosis patients infected with different serovars

Introduction The aim of the study was to compare haemoglobin and red cell counts between patients known to be infected with a range of leptospiral serovars. Methods The study retrospectively compared the haemoglobin and red cell count results from the first blood samples taken from 207 patients at presentation to a Queensland Health hospital. Results Significant differences were observed in haemoglobin and red cell counts in those infected with Leptospira interrogans serovars Szwajizak and Canicola when compared with most of the other serovars. Conclusions These findings suggest that haemoglobin and red cell counts may be useful in differentiating leptospiral serovars in leptospirosis patients. .