Leptospira Serovars Research Articles

Discovery of Leptospira spp. seroreactive peptides using ORFeome phage display.

BackgroundLeptospirosis is the most common zoonotic disease worldwide. The diagnostic performance of a serological test for human leptospirosis is mainly influenced by the antigen used in the test assay. An ideal serological test should cover all serovars of pathogenic leptospires with high sensitivity and specificity and use reagents that are relatively inexpensive to produce and can be used in tropical climates. Peptide-based tests fulfil at least the latter two requirements, and ORFeome phage display has been successfully used to identify immunogenic peptides from other pathogens.Methodology/Principal findingsTwo ORFeome phage display libraries of the entire Leptospira spp. genomes from five local strains isolated in Malaysia and seven WHO reference strains were constructed. Subsequently, 18 unique Leptospira peptides were identified in a screen using a pool of sera from patients with acute leptospirosis. Five of these were validated by titration ELISA using different pools of patient or control sera. The diagnostic performance of these five peptides was then assessed against 16 individual sera from patients with acute leptospirosis and 16 healthy donors and was compared to that of two recombinant reference proteins from L. interrogans. This analysis revealed two peptides (SIR16-D1 and SIR16-H1) from the local isolates with good accuracy for the detection of acute leptospirosis (area under the ROC curve: 0.86 and 0.78, respectively; sensitivity: 0.88 and 0.94; specificity: 0.81 and 0.69), which was close to that of the reference proteins LipL32 and Loa22 (area under the ROC curve: 0.91 and 0.80; sensitivity: 0.94 and 0.81; specificity: 0.75 and 0.75).Conclusions/SignificanceThis analysis lends further support for using ORFeome phage display to identify pathogen-associated immunogenic peptides, and it suggests that this technique holds promise for the development of peptide-based diagnostics for leptospirosis and, possibly, of vaccines against this pathogen.

Alteration of the Reproductive Indicators by the Presence of Leptospira spp. in Sows of Swine Farms

Background: Leptospirosis is a worldwide disease that impacts health, welfare and animal production. Manifestations in swine range from subclinical to severe cases of reproductive failure, generating abortions, embryonic resorption, litters with few piglets, and piglets born weak or dead, which causes great economic losses. Tropical conditions in Colombia favor transmission and maintenance of Leptospira, highlighting the importance of implementing direct diagnostic techniques such as isolation through culture to reach a definitive diagnosis. The objective of the present study was to relate reproductive indicators behavior with the presence of Leptospira spp. in two pig farms in Cundinamarca, Colombia.Materials, Methods & Results: Sows in reproductive stage in two pig farms were selected. A clinical examination of the animals was performed to demonstrate the presence of signs suggestive of Leptospirosis, also the sow records were reviewed to find reports of any of these clinical manifestations, and the average of the reproductive indicators was calculated to set which were altered in the sows. Blood and urine samples were obtained and analyzed by microscopic agglutination test (MAT) and isolation through culture, respectively. Among the altered reproductive indicators were identified: total pigs born (TPB) in 72.5%, stillbirths (SB) by 70%, mummified pigs (MUM) in a 52.5%, pre-weaning death (PWD) by 40% and the 24 h mortality (M24h) in the 20%. The 77.5% of the sows were positive by MAT. The predominant serovars of Leptospira spp. included Grippotyphosa (67.5%), Canicola (22.5%), Icterohaemorrhagiae (20%), Hardjo (17.5%) and Pomona (12.5%). The bacterium was isolated in 32.5% of the analyzed urine samples. There is increased risk of alteration in the indicators M24h (1.27), TPB (1.08), SB (1.15) and MUM (1.27) with the presence of Leptospira by isolation through culture.Discussion: The birth of weak piglets and the alteration of indicators such as SB were the most common findings in this study, which are of the major alterations caused by the bacteria because Leptospira can be located in the uterus. Positive cultures, 32.5% (13/40), indicate a high percentage of positive animals in the population. The total of positive culture results reveal that humans, pigs and other animal species from the farms and surrounding areas, are at risk of exposure to the bacteria, because these positive sows are eliminating the microorganism through urine to the environment, representing a problem for public health. This is why it is important to perform the identification of bacteria in urine. It establishes whether the animal is a carrier, although the non-detection of the microorganism in the urine does not rule out that this is a chronic renal carrier because it may indicate that at the moment of the test the animal was not excreting detectable amounts of the bacteria. The total of positive sera (77.5%) indicates a high seropositivity of swine leptospirosis in the population. Regarding serovars of Leptospira spp. identified, Grippotyphosa has the largest presentation (67.5%), therefore, as pigs are not maintenance hosts of this serovar, the results of this study suggest that synanthropic rodents that are found on farms may be transmitting the bacteria to pigs. The reproductive indicators related to the Leptospira serovars by X2 test, demonstrated significant association between the average of SB and the serovar Pomona, which has as reservoir the swine species and it is related with the production of piglets born dead, while through the Pearson correlation coefficient it was found that the greater the number of positive samples to serovar Pomona there is a greater presentation of weak piglets, and also was demonstrated that animals with Leptospira spp. have a higher risk to present alterations of the M24h, the average of TPB, SB and MUM.

Identification of Pathogenic Leptospiral Serovars by Detection of the ompl37 Gene Using PCR

Identification of Pathogenic Leptospiral Serovars by Detection of the ompl37 Gene Using PCR

Antibodies produced by dogs successfully challenged with live Leptospira spp. did not cross-react to Brucella antigen in a commercial rapid slide agglutination test that detects antibodies to Brucella canis.

Brucella canis is a cause of canine infertility and abortion. Veterinarians and veterinary laboratorians screen for antibodies to B. canis with serologic tests including a rapid slide agglutination test (RSAT; D-Tec CB, Zoetis, San Diego, CA). False-positive results are possible because of cross-reactivity to antibodies to some gram-negative bacteria. Cross-reactivity has been reported between antibodies of Brucella abortus and Leptospira spp. with serologic tests for bovine brucellosis; however, this has not been documented with serologic tests for canine brucellosis, to the author's knowledge. The RSAT was evaluated with the sera from dogs experimentally challenged with 1 of 4 serovars of Leptospira spp.: L. kirschneri serovar Grippotyphosa, or L. interrogans serovars Canicola, Icterohaemorrhagiae, or Pomona. Experimental infections were confirmed through results of microscopic agglutination testing and/or lateral flow immunochromatography testing. The sera of 32 dogs collected at day 0 and days 7, 10, and 14 yielded negative results with the RSAT. Antibodies produced through experimental infections to these 4 serovars of Leptospira spp. did not cross-react with Brucella antigen with the RSAT; therefore, cross-reactivity of anti-leptospiral antibodies may not be of concern for B. canis rapid slide agglutination testing of dogs.

Serological evidence of anti-Leptospira antibodies in goats in various agro climatic zones of India

Leptospirosis is an infectious disease which causes reproductive disorders in goats and is considered as one of the important factors responsible for hampering the productivity of Indian goat husbandry. Microscopic Agglutination Test (MAT) was employed in the present study to detect anti-leptospira antibodies in suspected serum samples of goats. The caprine sera analyzed in the present study were collected from different states of India representing twelve agro-climatic zones. Out of 2075 caprine sera screened, we found agglutinins against various leptospiral serovars in 371 goats (seropositivity 17.88%).The present study indicates proclivity of leptospiral serovars to thrive in specific agro-climatic zones of India (Spatial Variation). The serovar Icterohaemorrhagiae was predominantly reported from sera collected from landlocked regions of Northern India (Upper and Middle Gangetic plains, Western and Eastern Himalayan region, Western dry region, Central and southern plateau and Hills). This lack of serovar diversity observed in landlocked regions is in stark contrast to the serovar epidemiology observed in peninsular and coastal belts of India (Gujarat, West and East coast plains and hills). The peninsular and coastal belts were bastions for a wide diversity of serovars such as Javanica, Australis, Autumnalis, Hardjoprajitno, Pyrogenes, Hebdomadis, Pomona and Djasiman which were encountered along with Icterohaemorrhagiae and Grippotyphosa. The vast majority of caprine sera screened from Andaman and Nicobar Islands, an archipelago located in Bay of Bengal, were positive for serovar Pyrogenes whereas serovars Icterohaemorrhagiae and Grippotyphosa which were predominantly reported from mainland India were restricted to a few positive sera samples. Thus, our study clearly suggests differences in geographic distribution of leptospiral serovars between agro-climatic zones. All the caprine sera subjected to MAT were further (n = 2075) screened using recombinant LipL41 based Latex Agglutination Test. The sensitivity of rLipL41 based LAT for 371 MAT positive sera was 88.40% and the specificity with 1704 MAT negative sera was 94.40%. Further, Kappa value of 0.828 for rLipL41 based LAT indicates high agreement with MAT. The results obtained with LipL41 based LAT indicates that this test has direct field applicability in resource poor settings as it yielded high sensitivity and specificity for detection of anti-Leptospira antibodies in serum samples from goats.

Seroprevalence of Leptospira spp., Toxoplasma gondii, and Dirofilaria immitis in Free-Roaming Cats in Iowa.

By the nature of their environment and behavior, free-roaming cats are at increased risk of exposure to a wide range of pathogens compared with client-owned cats. Consequently, free-roaming cats can act as a reservoir for possible zoonotic infections. In this study, 140 cats were prospectively recruited over a 12-month period from a free-roaming cat spay and neuter clinic and a local animal shelter in the state of Iowa. The presence of antileptospiral antibodies was measured using a microscopic agglutination test against six leptospiral serovars (canicola, pomona, icterhemorrhagiae, bratislava, hardjo, and grippotyphosa). In addition, serum samples were tested for the presence of antibodies against Toxoplasma gondii and Dirofilaria immitis using an ELISA and lateral flow immunoassay, respectively. Serum samples from 12/139 cats (8.6%) were positive for the leptospiral serovars tested, with bratislava having the highest prevalence. Cats were more likely to be positive in the spring than in the fall or summer. Positive titers to T. gondii and D. immitis were present in 42/140 cats (30%) and 9/140 cats (6.4%), respectively. Cats >72 months of age were more likely to be seropositive to T. gondii than cats in younger age groups. Feline Leptospira spp. seroprevalence was higher in this Midwestern location than has previously been reported elsewhere in the United States. Contrary to previously reported seasonal trends, this population was more likely to be Leptospira spp. seropositive in the spring rather than fall or summer. Seroprevalence of D. immitis in this geographical location was substantially lower than previous reports of free-roaming cats in the United States.

A 3-year retrospective analysis on the prevalence of antileptospiral antibodies among children in Chennai City, India.

Leptospirosis is a re-emerging infectious disease that has been reported from all over the world, including South India. Several studies have documented the prevalence of Leptospira in the general population. However, the data on leptospirosis in children were limited. We evaluated the prevalence of antileptospiral antibodies and the distribution of Leptospira serovars in children and adolescents. In this retrospective study, details for a total of 5407 children who presented with fever and whose test results for antileptospiral antibodies available were recorded. A microscopic agglutination test (MAT) was performed to detect the presence of anti-leptospiral antibodies and a titre of more than 1 : 80 was considered positive. The antigen panel included the following six serovars: Icterohaemorrhagiae, Canicola, Autumnalis, Australis, Grippotyphosa and Patoc. Demographics such as age and gender were recorded. An overall seropositivity rate of 30.8 % (95 % CI: 21.54-25.81) was observed. More male children (59 %) were infected than female children (41 %). Leptospirosis occurs throughout the year among children. Cases peak in the summer time and during the months of November and December. The most prevalent serovar in this study was L. Canicola followed by L. Australis and L. Autumnalis. This seroprevalence study suggested that leptospirosis occurs among children throughout the year in Chennai, India. This makes it almost mandatory to include it in the differential diagnosis for febrile illnesses in children. Early detection and treatment, together with control measures, may significantly reduce the spread of this endemic pathogen in this city.

SEVERE PULMONARY LEPTOSPIROSIS REQUIRING ECMO

SESSION TITLE: Chest Infections 3 SESSION TYPE: Fellow Case Reports PRESENTED ON: 10/08/2018 11:00 AM - 12:00 PM INTRODUCTION: Severe pulmonary disease due to Leptospira spp. is an infrequent complication of systemic infection and may be under-recognized in endemic areas. It can be manifested by pulmonary hemorrhage and ARDS with associated multisystem organ failure to include hepatic, renal and CNS manifestations. In patients with pulmonary leptospirosis in endemic areas, the mortality may be over 75%. We report the use of extracorporeal membrane oxygenation (ECMO) for a patient with severe leptospirosis infection. CASE PRESENTATION: The patient was a 47-year-old male who traveled to Jamaica for his honeymoon and returned with general malaise. He was admitted to an outside facility where he was found to have hyperbilirubinemia, thrombocytopenia, and acute kidney injury. His course progressed and he developed massive hemoptysis for which he was intubated and required high ventilatory support to maintain oxygenation. Due to progressive renal failure, he was initiated on CRRT; however, despite attempts at ultrafiltration, he became volume overloaded over several days. He was transferred to our facility and placed on ECMO due to worsening oxygenation. Infectious Disease consultation confirmed the diagnosis of leptospirosis-induced vasculitis. Initial head CT imaging after transfer demonstrated bilateral subarachnoid hemorrhages and subgaleal hemorrhage with later development of large left frontal intracerebral hemorrhage following EVD placement for elevated CSF pressures. In addition to ECMO, he required plasma exchange due to liver failure for hyperbilirubinemia and as well as CRRT for anuric renal failure. Over the next two weeks, he developed worsening CNS changes consistent with uncal herniation. MRI was obtained and demonstrated diffuse axonal injury with greater than right anterior frontal intraparenchymal hemorrhage extending into both lateral ventricles and layering within both occipital horns. Due to progressive uncal hernation, hypotension, and worsening hypoxemia, the patient expired several days later. DISCUSSION: Massive pulmonary hemorrhage and vasculitis due to leptospirosis is uncommon and often associated with multi-organ system failure. Several case reports have described the successful use of ECMO in the setting of massive pulmonary hemorrhage. These cases were also complicated by thrombocytopenia, hepatic, and renal failure but did not report CNS involvement. An important adjunct in these cases was maintaining airway patency with use of bronchoscopy. CONCLUSIONS: Clinicians should consider ECMO as a possible rescue therapy for patients with pulmonary leptospirosis. Reference #1: Hery G, Letheulle J, Flecher E, et al. Massive intra-alveolar hemorrhage caused by leptospira serovar Djasiman in a traveler returning from Laos. J Travel Medicine 2015; 22 (3):212–214. Reference #2: Arokianathan D, Trower K, Pooboni S, et al. Leptospirosis: a case report of a patient with pulmonary haemorrhage successfully managed with extra corporeal membrane oxygenation. J Infection 2005; 50(2):158-162. Reference #3: Liao CY, Ben RJ, Wu HM, et al. Acute respiratory distress syndrome manifested by leptospirosis successfully treated by ECMO. Int Med (Japan) 2015; 54 (22):2943-46. DISCLOSURES: No relevant relationships by Mauer Biscotti, source=Web Response No relevant relationships by Andrew Hersh, source=Web Response No relevant relationships by Matthew Koroscil, source=Web Response Speaker/Speaker's Bureau relationship with Janssen Pharmaceuticals Please note: $1001 - $5000 Added 11/27/2017 by Michael Morris, source=Web Response, value=Consulting fee Speaker/Speaker's Bureau relationship with Vyaire Medical Please note: $1001 - $5000 Added 11/27/2017 by Michael Morris, source=Web Response, value=Consulting fee No relevant relationships by Robert Walter, source=Web Response

Apparently high Leptospira antibody seropositivity in donkeys for slaughter in three municipalities in Durango, Mexico.

We determined the seropositive percentage and the determinants of Leptospira exposure in domestic donkeys presented for slaughter in the State of Durango, Mexico. We examined 194 donkeys in 4 gathering premises. Sera of donkeys were analyzed for anti- Leptospira IgG antibodies using a microscopic agglutination assay with a panel of 7 Leptospira antigens. The association between Leptospira seropositivity and general characteristics of donkeys was assessed by bivariate and multivariate analyses. Antibodies against Leptospira (for at least 1 of the 7 Leptospira serovars examined) were found in 151 of 194 (77.8%) donkeys. Seropositive donkeys were found in all regions, municipalities, and premises examined. The predominant serovar was L. interrogans Icterohaemorrhagiae ( n = 117; 60.3%), followed by L. interrogans Sejroe ( n = 96; 49.5%), L. interrogans Canicola ( n = 10; 5.2%), L. kirschneri Grippotyphosa ( n = 6; 3.1%), L. borgpetersenii Ballum ( n = 5; 2.6 %), L. biflexa Semaranga ( n = 3; 1.5%), and L. noguchii Panama ( n = 2; 1%). Leptospira seropositivity was associated with gathering premises (OR = 2.64; 95% CI: 1.27-5.46; p = 0.009) and municipalities (OR = 0.11; 95% CI: 0.01-0.78; p = 0.02). Our results demonstrate an apparently high seropositive percentage of Leptospira infection in the donkeys studied in Mexico.

Isolation of pathogenic Leptospira strains from naturally infected cattle in Uruguay reveals high serovar diversity, and uncovers a relevant risk for human leptospirosis.

Leptospirosis is a neglected zoonosis with worldwide distribution. The causative agents are spirochete bacteria of the Leptospira genus, displaying huge diversity of serovars, the identity of which is critical for effective diagnosis and vaccination purposes. Among many other mammalian species, Leptospira infects cattle, eliciting acute signs in calves, and chronic disease in adult animals often leading to abortions. In South America, and including in Uruguay, beef and dairy export are leading sources of national income. Despite the importance of bovine health, food safety, and bovine-related dissemination of leptospirosis to humans, extremely limited information is available as to the identity of Leptospira species and serovars infecting cattle in Uruguay and the South American subcontinent. Here we report a multicentric 3-year study resulting in the isolation and detailed characterization of 40 strains of Leptospira spp. obtained from infected cattle. Combined serologic and molecular typing identified these isolates as L. interrogans serogroup Pomona serovar Kennewicki (20 strains), L. interrogans serogroup Canicola serovar Canicola (1 strain), L. borgpetersenii serogroup Sejroe serovar Hardjo (10 strains) and L. noguchii (9 strains). The latter showed remarkable phenotypic and genetic variability, belonging to 6 distinct serogroups, including 3 that did not react with a large panel of reference serogrouping antisera. Approximately 20% of cattle sampled in the field were found to be shedding pathogenic Leptospira in their urine, uncovering a threat for public health that is being largely neglected. The two L. interrogans serovars that we isolated from cattle displayed identical genetic signatures to those of human isolates that had previously been obtained from leptospirosis patients. This report of local Leptospira strains shall improve diagnostic tools and the understanding of leptospirosis epidemiology in South America. These strains could also be used as new components within bacterin vaccines to protect against the pathogenic Leptospira strains that are actually circulating, a direct measure to reduce the risk of human leptospirosis.

SEROEPIDEMIOLOGIC SURVEY OF CANINE LEPTOSPIROSIS IN NORTHERN TAIWAN DURING 2008–2015

Leptospirosis is an important infectious zoonosis that may cause life-threatening illness in both humans and animals. This study aimed to identify the serovars of Leptospira using the microscopic agglutination test (MAT) and the effect of season on serum-positive cases detected in National Taiwan University Veterinary Hospital from August 2008 to September 2015. This study also compared the characteristics of serum-positive and serum-negative cases. Among 159 suspected cases, 78 serum-positive (MAT titer [Formula: see text]) and 81 serum-negative cases were identified. In serum-positive cases, the most common pathogenic serovars were Canicola (18.2%), Icterohaemorrhagiae (23.6%), and Shermani (20.0%). Significantly more serum-positive cases were identified in fall (September to November) than other seasons ([Formula: see text]). Dogs aged 1–5 years (odds ratio [Formula: see text] 1.7) were more likely to be identified as being serum-positive cases of canine leptospirosis than serum-negative cases. However, no significant difference was observed regarding breed, gender, and regional distribution. The serum concentrations of liver enzymes, total bilirubin, blood urea nitrogen, and creatinine were elevated in both serum-positive and serum-negative cases, with no significance. White blood cell (WBC) counts of serum-positive cases were statistically higher than those of serum-negative cases ([Formula: see text]). In conclusion, more precaution must be taken with dogs aged 1–5 years because of their higher risk of leptospirosis; additionally, significantly elevated WBC count may be a suitable indicator in suspected cases of canine leptospirosis.

Molecular characterization of pathogenic Leptospira sp. in small mammals captured from the human leptospirosis suspected areas of Selangor state, Malaysia

Leptospirosis is caused by the spirochetal bacterium Leptospira of which rodents are considered the most important reservoir. This study aims to determine and characterize virulent Leptospira species among rodents and small mammals found in human settlements and recreational spots within the Hulu Langat and Gombak districts of Selangor, Malaysia; regions that frequently report probable human leptospirosis cases. Molecular analysis revealed an overall Leptospira detection rate of 14.3% among the 266 small mammals captured, and the human settlements were found to have the highest number of isolates (15.1%), followed by recreational sites (14.5%). The molecular characterization conducted based on the lipL32, secY genes and MLST revealed that the strains belonged to four different species, including; Leptospira interrogans (29; 76.3%; ST50, ST238, ST243), L. kirschneri (5; 13.15%; ST110), L. borgpetersenii (3; 8%; ST143) and L. weilii (1; 2.63%; ST242). The study revealed genotypes of circulating strains among small mammals in Malaysia, which include Leptospira locus ST110 L. kirschneri, ST 50 L. interrogans, ST143 L. borgpetersenii and ST242 L. weilii. Among the small mammals studied, 17/105 (16.2%) Rattus norvegicus, 7/59 (11.9%) of Rattus rattus, 5/24 (20.8%) of Maxomys whiteheadi, 4/18 (22.2%) of Sundamys muelleri, 2/22 (9%), Tupaia gliss, 2/16 (12.5%) Rattus tiomanicus and 1/4 (25%) of Suncus murinus carried pathogenic leptospires. The data from the present study may imply that, in addition to rodents, other small mammals also serve as maintenance hosts for Leptospira. Hence, much remains unknown about Leptospira maintenance hosts, and there is need for further investigation to ascertain the prevailing serovars of pathogenic Leptospira in Malaysia. This will assist in the development of efficient diagnostic assays with improved microscopic agglutination test (MAT) panels, and in the implementation of suitable prevention and control measures.

Antigenic potential of a recombinant polyvalent DNA vaccine against pathogenic leptospiral infection

Leptospirosis is a serious epidemic disease caused by pathogenic Leptospira species. The disease is endemic in most tropical and sub-tropical regions of the world. Currently, there is no effective polyvalent vaccine for prevention against most of the circulating serovars. Moreover, development of an efficient leptospiral vaccine capable of stimulating cross-protective immune responses against a wide range of serovars remains a daunting challenge. This, in part, is associated with the extensive diversity and variation of leptospiral serovars from region to region. In this study, a multi-epitope DNA vaccine encoding highly immunogenic epitopes from LipL32 and LipL41 was designed using in-silico approach. The DNA encoding antigenic epitopes was constructed from conserved pathogenic Leptospira genes (LipL32 and LipL41). Immunization of golden Syrian hamsters with the multi-epitope chimeric DNA vaccine resulted in the production of both agglutinating and neutralizing antibodies as evidence by MAT and in-vitro growth inhibition tests respectively. The antibodies produced reacted against eight different serovars and significantly reduced renal colonization following in vivo challenge. The vaccine was also able to significantly reduce renal colonization which is a very important factor responsible for persistence of leptospires among susceptible and reservoir animal hosts. In conclusion, the leptospiral multi-epitope chimeric DNA vaccine can serve as a potentially effective and safe vaccine against infection with different pathogenic leptospiral serovars.

Seroprevalence of Leptospira spp infection and its risk factors among domestic dogs in Bogotá, Colombia

Different analytical tools were used to determine the seroprevalence of and risk factors associated with Leptospira spp infection in 192 domestic dogs (Canis familiaris) in Bogotá, Colombia. Using the microscopic agglutination test (MAT), a battery of 16 Leptospira serovars were tested. The seroprevalence of Leptospira spp was calculated as 36.46% (95% CI 0.30-0.43). A questionnaire was applied to the dogs’ owners at the time of sampling and the variables “Water sources near home” and “Dog hunting rodents” were identified as risk factors for leptospirosis occurrence in the urban area of Bogotá. Geographical coordinates relating to the dogs’ households were obtained in order to map out the spatial distribution of reactive and unreactive dogs. Additionally, we found that the mean annual precipitation was higher at geographical locations with reactive animals than at those with unreactive dogs (p < 0.05). Preventing exposure of dogs to rodents and waste-water bodies that could be contaminated with Leptospira might effectively reduce occurrences of leptospirosis. Moreover, promoting preventive programs and vaccination of dogs against leptospirosis in areas of higher precipitation and prior to rainy months could be an effective strategy for leptospirosis prevention.

Occurrence of brucellosis, leptospirosis and neosporosis in cows with retained placenta in Southwest Paraná, Brazil

ABSTRACT: The aim of this study was to measure the occurrence of brucellosis, leptospirosis and neosporosis in cows from 25 family farms milk, with semi-intensive grazing system, located in the Southwest region of Paraná, Brazil. Eighty-four cows with retained placenta, between July 2013 to July 2014, diagnosed by the presence of fetal membranes in the uterus up to 12 hours after partum, decrease of appetite and of milk production, as well increase of rectal temperature were included into the study. The animals were submitted to blood collection for evaluating the seropositivity for brucellosis, leptospirosis and neosporosis. The blood was collected at 15 to 45 days postpartum, avoiding false negative results due to immune deficiency observed in the transition period. After collection, the blood was centrifuged, the serum was packed in three aliquots, identified and subsequently frozen. Serology was performed to diagnose brucellosis (technique of buffered acidified antigen), leptospirosis (through the microscopic agglutination test - MAT) and neosporosis (indirect immunofluorescence test). Animals were considered positive when presenting titer &gt;1:100 (leptospirosis) and 1:200 (neosporosis). No animal with placenta retention presented Brucella abortus bacteria; 39% (33/84) were reactive to one or more Leptospira serovars, 15% (13/84) were positive to Neospora caninum, and 4% (4/84) had both diagnosis, being reactive for leptospirosis and neosporosis. In conclusion, data from this experiment inspires greater attention to leptospirosis and neosporosis in dairy cattle presenting placenta retention in southwest Paraná.

Comparative analysis of incidence of leptospirosis among farm animals and humans in Ukraine

Leptospirosis remains one of the most widespread natural-focal, zoonotic infectious diseases in the world and in Ukraine. Leptospirosis is enzootic in the entire territory of Ukraine. Cases of diseases are registered in all regions of Ukraine. We initiated a study of comparative analysis of territorial distribution of leptospirosis outbreaks among animals and incidence in humans in Ukraine covering the years 2009–2016 inclusive. This study of the incidence of leptospirosis in Ukraine shows a significant circulation of leptospirosis both among humans and animals. Among cattle herds in Ukraine the percentage of positive animals was found to be 4.2% of the surveyed population. The dominant serovars of Leptospira were kabura (12.4%) and polonica (9.5%). Positive reactions with other serovars were observed less frequently: tarassovi – 5.1%, bratislava – 4.9%, copenhageni – 4.1%, grippotyphosa – 2.4%, pomona – 1.1%, canicola – 1.0%. In pigs, the percentage of positive animals amounted to 3.2%, the dominant serovars of Leptospira were bratislava (29.1%) and copenhageni (25.1%). Positive reactions with other serovars were observed less frequently: tarassovi – 4.3%, canicola – 3.0%, pomona – 2.7%, grippotyphosa – 1.3%, polonica – 1.2%, kabura – 0.6%. In horses, the percentage of positive animals amounted to 9.5% of the surveyed population. The serological range of Leptospira in horses was as follows: copenhageni – 14.2%, bratislava – 12.1%, canicola – 6.8%, grippotyphosa – 4.8%, tarassovi – 4.7%, pomona – 2.1%, kabura – 1.4%, polonica – 1.3%. Analysis of the results of research indicates extensive circulation of leptospirosis among humans in Ukraine as evidenced by the percentage of humans positively responding to MAT – 12.1% of the studied samples. The etiological structure of leptospirosis cases includes all the 14 serovars of the diagnostic set. The basis of the etiological spectrum was the serovar copenhageni – 37.3%. The share of other serovars as the etiological factor of leptospirosis in humans was different in different spans of the considered period. Most frequently, those were kabura – 12.3%, grippotyphosa – 11.7%, canicola – 9.5%, pomona – 9.1%. We mapped annual incidence of leptospirosis in animals and humans. Choropleth maps of annual leptospirosis incidence and cluster maps show opposite spatial patterns for animals and humans. The highest human rates were in the western and central parts of the country while the highest animal rates were mainly in the eastern part.

Heterologous protection elicited by a live, attenuated, Leptospira vaccine

A previously-described live, attenuated vaccine (M1352, serovar Manilae, serogroup Pyrogenes) was tested in the hamster model of infection for cross-protective immunity. The vaccine elicited strong, significant cross-protection against lethal infection by strains representing four serologically distinct leptospiral serovars (Grippotyphosa, Australis, Canicola, and Autumnalis). Combined with our previously reported protection against serovars Pomona and Manilae, this work demonstrates unequivocal proof of concept for cross-protective immunity in leptospirosis.

Seroepidemiology of Leptospira Infection in Backyard Pigs in Durango State, Mexico.

PurposeThis study aimed to determine the seroprevalence and correlates of Leptospira IgG antibodies in backyard pigs in the northern Mexican state of Durango. We performed a cross-sectional study of 305 backyard pigs. Anti-Leptospira IgG antibodies were detected using microscopic agglutination assay (MAT) with a panel of 12 Leptospira antigens.ResultsOverall, antibodies against Leptospira (any of the 12 Leptospira serovars examined) were found in 186 (61.0%) of the 305 pigs studied. Seropositive pigs were found on 80 (70.2%) of the 114 properties surveyed. The predominant serovar was Leptospira interrogans Pomona (n = 55); followed by Leptospira noguchii Lousiana and Leptospira santarosai Tarassovi (n = 53 each); L. interrogans Bataviae (n = 47); Leptospira biflexa Semaranga and L. interrogans Hebdomadis (n = 36 each); L. interrogans Pyrogenes (n = 30); L. interrogans Djasiman (n = 20); Leptospira borgpetersenii Ballum (n = 11); L. noguchii Panama and L. interrogans Canicola (n = 5 each); and L. borgpetersenii Mini (n = 2). Logistic regression showed that seropositivity was associated with low (<1000 m above sea level) altitude (odds ratio [OR] = 3.24; 95% confidence interval [CI]: 2.01–5.20; P < 0.001).ConclusionsThis is the first report of Leptospira exposure in backyard pigs in Mexico and of an association between Leptospira exposure in pigs and altitude. Backyard pigs represent a high-risk group for Leptospira exposure.

Diagnostic procedure after abortions in sows after simultaneous infection with leptospira and chlamydia

In a farrowing farm 2 first parity sows aborted on day 95 and day 110 of gestation due to an infection with leptospira and chlamydia. The double infection was diagnosed by PCR examination of abortion material. Serum samples of both sows and additional 8 sows taken three weeks after abortions were sent to two different labs for serological examination for antibodies against leptospira and chlamydia using a microagglutination test and a complement fixation test, respectively. In both labs the tests for antibodies against chlamydia were negative. Titers against diverse leptospira serovars varied between both labs and were low, so that they were not indicative for the involvement of the two pathogens regarding abortion. This case report indicates the diagnostic difficulties of direct and indirect detection methods for leptospira and chlamydia to assess the impact of these pathogens on observed reproductive failure.

Trypanosoma vivax in Dairy Cattle

Background: Trypanosoma vivax is a protozoan that causes reproductive disorders and decreased production in domestic and wild ungulate animals. The bovine are the main hosts of the disease and the transmission occurs by the bite of hematophagous insects, mainly tabanids. Several diagnostic techniques can be used to detect the parasite, both in parasitologicalform and by serological kits. In Brazil, the disease has been reported in bovines, goats and sheep of some states, with high morbidity and mortality and due to the scarcity of results on the epidemiology of the disease, this work had the objective to report the presence of T. vivax in a female bovine of a dairy herd in Parnaíba county, Piauí.Case: The animal naturally infected by Trypanosoma vivax, was a three-year-old cow from a dairy farm in the Parnaíba county, located in the north of Piauí state. The farm had a herd whith 62.20% of young Girolando breed cows and the breeding system used was semi-confinement, with two mechanical milking per day. At the time of a Veterinarian’s technicalvisit to the property, it was observed the occurrence of abortions, mastitis, estrus repetitions and cows with hematuria, leading to the suspicion of the bovine leptospirosis occurrence. Blood samples were collected from 78 cows from the herd for hematological, biochemical and serological tests, and 72 (92.30%) were reactive to some Leptospira serovars. All the exams were carried out at the Federal University of Piauí (UFPI). In the group of animals negative for leptospirosis, a female was diagnosed positive for bovine trypanosomiasis, confirming the result in the blood smear. This animal had no clinical signs characteristic of the disease at the time of the evaluation.Discussion: Blood trypomastigote forms of Trypanosoma vivax were visualized on several slides of the animal smear and all the morphological structures of the parasite found were clearly seen under microscopyas described in the literature. The hematological alterations observed were normochromic normocytic anemia, thrombocytopenia, leukocytosis due tolymphocytosis, monocytosis and eosinophilia. The anemia and leukocytosis clinical condition found in the specific animal is commonly found in bovines naturally infected by trypanosomiasis in the chronic phase of the disease. The results of the serum biochemistry revealed decreased blood glucose and increased renal and hepatic parameters, as well as the inversion of the albumin-globulin ratio. Similar laboratory results were also described previously. The animal had a good body score, a good diet and showed no clinical signs of the disease. A good nutrition may have controlled the T. vivax parasitaemia, avoiding the characterization of the clinical condition. This fact can be attributed to the differences in pathogenicity of the parasite and/or susceptibility of a particular host. In the area of the farm where the cattle were housed the presence ofseveral tabanids was noticed and the increase of these insects in the environment is considered a risk factor, predisposing, even, the occurrence of new outbreaks. The epidemiological situation of the disease in Brazil is described, for the most part, by reports of outbreaks or specific events, revealing the lack of more consistent studies. With this result it is knownthat trypanosomiasis exists in the dairy herd of the state of Piauí, being important to carry out new work to diagnose the epidemiological situation of the disease within the productive context of our region.Keywords: bovine, dairy herd, trypanosomiasis.