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Presence of zoonotic pathogens (Yersinia spp., Campylobacter jejuni, Salmonella spp., and Leptospira spp.) simultaneously in dogs and cats.

The purpose of this study was to determine the presence of zoonotic pathogens simultaneously in animals. The isolation of human pathogenic Yersinia enterocolitica (Ye), Yersinia pseudotuberculosis (Yp), Campylobacter jejuni (Cj), Salmonella spp. (Sal) and Leptospira spp. (Lep) in 318 cats and 252 dogs were performed in Shimane Prefecture, Japan. A total of 13 isolates of Yp (4 strains) and Sal (9 strains) were recovered from intestine and/or mesenteric lymph nodes (MLN) of 13 cats (4.1%) but not Ye, and Cj was not examined. A total of 88 isolates of Ye (15 dogs, 15 strains), Yp (16 dogs, 16 strains), Cj (10 dogs, 13 strains) and Sal (39 dogs, 44 strains) were recovered from intestine and/or MLN of 76 dogs (30.2%). Two species of Ye O3, Cj and Sal were recovered from either intestine or MLN of 4 dogs but not from cats. Lep was not detected in dogs and cats kidney. The 101 isolates from dogs and cats belonged to Ye 3B/O3/II (biotype/serotype/phage type) (2 strains), 4/O3/VIII (10 strains) and 2/O5,27 (3 strains), Yp serotypes 1b, 2b (each 3 strains), 2c (2 strains), 4a (2 strains), 4b (4 strains), 5a (5 strains) and 7 (1 strain), Cj serotypes TCK 9, 13, 26 (each 1 strain), 21 (2 strains) and untypable (8 strains) and 24 serotypes of Sal. Ye O3 and Yp were detected frequently in cold months. There was no definite seasonal variation of Ye O5,27 Cj and Sal in internal origin of dogs and cats. Ye O3, Yp and Cj were counted at 10(2) to 10(7) cells per g of the jejunal-to-rectal contents, but Sal at less than 10(2) cells per g of the intestinal contents. Ye O3, Yp and Sal were recovered from mesenteric lymph nodes, but not Ye O5,27 and Cj.

Animals↗

Comparison of immunoreactive proteins of commonly circulating serogroups of Leptospira in Andaman Islands, India.

BACKGROUND & OBJECTIVE: Early diagnosis is the key to the treatment of leptospirosis. For development of rapid diagnostic kits, a thorough knowledge about the nature of the proteins expressed by the pathogen during infection is necessary. The present study was undertaken to understand the nature of immunoreactive proteins from commonly circulating serogroups of Leptospira in the endemic Andaman and Nicobar Islands, India. METHODS: Proteins were extracted from six strains of Leptospira representing five different serogroups following four different preparation methods, viz., whole cell lysis by sonication, detergent solubilization, outer and inner membrane isolations, and were subsequently characterized on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoblots were made from the sonicated proteins using hyperimmune rabbit antisera, homologous and heterologous patient sera separately. RESULTS: The 67, 65, 45, 43, 35, 32 and 18 kDa major proteins in the whole cell lysate were common among all the five serogroups of Leptospira. The 67, 41, 35, 32, 28 and 22 kDa were the major outer membrane proteins, while 94, 32, 25 and 18 kDa protein were in inner membrane. Immunoblots with hyperimmune rabbit antisera detected 67, 65, 60, 45, 43, 41 and 32 kDa common proteins from the whole cell lysates of all strains while homologous and heterologous patient sera detected 32 kDa as the major immunoreactive protein in all pathogenic serogroups. This protein reacted against specific LipL32 antisera indicating that this protein was LipL32. INTERPRETATION & CONCLUSION: The circulating serogroups of Leptospira have common nature of expression of proteins during human infection. Among several immunoreactive proteins, three (67, 45 and 32 kDa) were recognized as major antigens by both rabbit hyperimmune sera and patients sera while the 32 kDa protein was recognized as the major immunoreactive protein by homologous and heterologous patient sera. These conserved immunoreactive proteins could be utilized in developing indigenous diagnostic tests for leptospirosis.

Animals↗

LipL21 is a novel surface-exposed lipoprotein of pathogenic Leptospira species.

Leptospira is the etiologic agent of leptospirosis, a bacterial zoonosis distributed worldwide. Leptospiral lipopolysaccharide is a protective immunogen, but the extensive serological diversity of leptospires has inspired a search for conserved outer membrane proteins (OMPs) that may stimulate heterologous immunity. Previously, a global analysis of leptospiral OMPs (P. A. Cullen, S. J. Cordwell, D. M. Bulach, D. A. Haake, and B. Adler, Infect. Immun. 70:2311-2318, 2002) identified pL21, a novel 21-kDa protein that is the second most abundant constituent of the Leptospira interrogans serovar Lai outer membrane proteome. In this study, we identified the gene encoding pL21 and found it to encode a putative lipoprotein; accordingly, the protein was renamed LipL21. Southern hybridization analysis revealed the presence of lipL21 in all of the pathogenic species but in none of the saprophytic species examined. Alignment of the LipL21 sequence from six strains of Leptospira revealed 96 to 100% identity. When specific polyclonal antisera to recombinant LipL21 were used, LipL21 was isolated together with other known leptospiral OMPs by both Triton X-114 extraction and sucrose density gradient membrane fractionation. All nine strains of pathogenic leptospires investigated by Western blotting, whether culture attenuated or virulent, were found to express LipL21. In contrast, the expression of LipL21 or an antigenically related protein could not be detected in nonpathogenic L. biflexa. Infected hamster sera and two of eight human leptospirosis sera tested were found to react with recombinant LipL21. Native LipL21 was found to incorporate tritiated palmitic acid, consistent with the prediction of a lipoprotein signal peptidase cleavage site. Biotinylation of the leptospiral surface resulted in selective labeling of LipL21 and the previously known OMPs LipL32 and LipL41. These findings show that LipL21 is a surface-exposed, abundant outer membrane lipoprotein that is expressed during infection and conserved among pathogenic Leptospira species.

Animals↗

Characterization of the cheY genes from Leptospira interrogans and their effects on the behavior of Escherichia coli.

The motility and chemotaxis system are critical for the virulence of pathogenic leptospire, which enable them to penetrate host tissue barriers during infection. The completed genome sequence of a representative virulent serovar type strain (Lai) of Leptospira interrogans serogroups Icterohaemorrhagiae (L. interrogans strain Lai) suggested that there were multiple copies of putative chemotaxis homologues located at its large chromosome. In order to verify the function of these proteins, the putative cheY genes were cloned into pQE31 vector and then expressed, respectively, in wild-type Escherichia coli strain RP437 and cheY defective strain RP5232. The results showed that all the five cheYs could restore the swarming of RP5232 strain to some extend. Overexpression of CheYs in RP437 showed inhibited swarming of RP437. To investigate the mechanism of chemotaxis signaling in L. interrogans strain Lai, certain aspartates (Asp-53, Asp-61, Asp-70, Asp-62, and Asp-66 for L. interrogans strain Lai CheY1, CheY2, CheY3, CheY4, and CheY5, respectively) were mutated. Expression of these mutated cheYs manifested neither restoration of the swarming ability of RP5232 nor inhibition on swarming ability of RP437. Multiple amino acid sequence alignment predicted ternary structures and the result of mutation experiment suggested that these conserved aspartate residues of L. interrogans were analogous to that in E. coli CheY in function and structure. So, L. interrogans and E. coli may have similar mechanisms of activation of the chemotaxis phosphorelay pathway, but there are differences in their control by signal terminator.

Amino Acid Sequence↗

Prevalence of leptospira antibodies in U.S. Army blood bank donors in Hawaii.

Leptospirosis is a zoonotic infection of worldwide distribution that is commonly endemic in tropical regions. In the United States, the annual incidence rate in the state of Hawaii is approximately 30 times higher than that reported nationally. U.S. troops deployed to disease-endemic tropical environments and those training in the state of Hawaii are potentially at high risk for acquiring leptospirosis. Serum and risk factor data were obtained from 488 blood donors attending military-sponsored blood drives on the island of Oahu. Testing of sera for the presence of Leptospira-specific antibodies was performed with microscopic agglutination testing (MAT). Seven active duty U.S. Army soldiers were found to be seropositive by MAT (seroprevalence, 1.4%), 2 of 76 newly arrived residents (2.6%) and 5 of 412 established residents (1.2%). Positive MAT results were statistically more common among female subjects and those 18 to 30 years old. Seropositivity was not associated with specific exposures or prolonged residence in the state of Hawaii.

Adolescent↗

Cross-reactivity between B. burgdorferi and other spirochetes affects specificity of serotests for detection of antibodies to the Lyme disease agent in dogs.

Western immunoblots, the kinetics-based enzyme-linked immunosorbent assay (KELA), and the microagglutination test were used to evaluate cross-reactivity among antibodies to serovars of Leptospira interrogans (leptospiral serovars), and B. burgdorferi from naturally infected dogs, and to Serpulina (Treponema) hyodysenteriae from vaccinated rabbits. Whole-cell lysates from Borrelia spp., leptospiral serovars, and Serpulina spp. were used for SDS-PAGE, western blots, and KELA. Crossreactivity occurred between the antibodies to B. burgdorferi and leptospiral serovars when tested on the heterologous antigens. Antibodies to leptospiral serovars tended to cross-react more strongly with antigens of B. burgdorferi spp. than did antibodies to B. burgdorferi when tested against antigens of leptospiral serovars. The antibodies against B. burgdorferi showed a lesser degree of cross-reactivity to the antigens of S. hyodysenteriae and S. innocens than they did to leptospiral serovars. We conclude that cross-reactivity occurs between B. burgdorferi and leptospiral serovars. Validation and interpretation of ELISA tests for detection of antibody activity to whole cell lysates of the Lyme agent must take this cross-reactivity into consideration. Conversely, dogs infected with the Lyme agent do not show significant cross-reactivity in the microagglutination test for antibody to the leptospiral serovars.

Agglutination Tests↗

Frequency-pulsed electron capture gas-liquid chromatography and the tryptophan color test for rapid diagnosis of tuberculous and other forms of lymphocytic meningitis.

A total of 260 samples of cerebrospinal fluid received from Egypt, the United States, Canada, and South America were examined by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC) for tuberculous and other forms of lymphocytic meningitis. Thirty-four of the specimens were culture positive for M. tuberculosis, and four cerebrospinal fluid specimens of herpes meningitis were established by immunological techniques. The compound, 3-(2'-ketohexyl)-indoline, was found in about 60% of the Egyptian tuberculous specimens and none of the culture-positive American specimens. the carboxylic and hydroxy acid FPEC-GLC profiles were used effectively in conjunction with other clinical data to make the diagnosis even in the absence of 3-(2'-ketohexyl)indoline. Herpes meningitis and mixed infections of Myeobacterium tuberculosis-herpes, M. tuberculosis-leptospira, and M. tuberculosis-Haemophilus influenzae produced profiles different from each other and from pure culture cases. The color test for tuberculous meningitis was evaluated, and free tryptophan was eliminated as the source of color reaction. Indications are that 3-(2'-ketohexyl)indoline, in most cases, is not responsible for the positive color reaction. Differences in the clinical and FPEC-GLC data obtained from samples from different geographical regions are discussed.

Cerebrospinal Fluid↗

Clinical aspects of ocular leptospirosis in New Caledonia (South Pacific).

PURPOSE: The incidence of leptospirosis is very high in New Caledonia (average annual incidence rate: 180/100 000 of the population). To investigate the role of pathogenic leptospires as an aetiological agent of ocular diseases, we report the results of a 5-year survey in New Caledonia. METHODS: We reviewed 13 patients (corresponding to 17 investigated pathologic eyes) retrospectively. The selection of patients was based on epidemiological data, initial clinical examination, biological confirmation of leptospirosis according to reference procedures and a specific polymerase chain reaction assay. The anatomic criteria of uveitis and the criteria describing the evolution of the disease were those recommended by the International Uveitis Study Group. RESULTS: Consequent rates of optic neuritis (65%), posterior uveitis (35%), secluded pupil (24%), interstitial keratitis (18%) and pars planitis (12%) were found. Our rates of recurrence (46%) and of ophthalmic complications (82%) were substantial; some symptoms indicated brain involvement.The final visual damage was severe in 35% of eyes. CONCLUSIONS: Microagglutination and polymerase chain reaction hybridization are complementary tests for the diagnosis of Leptospira-induced ophthalmic lesions. Before deciding on treatment, one must consider the ability of virulent leptospires to persist in immunologically privileged sites such as aqueous humor, cerebrospinal fluid and eukaryotic cells. Polymerase chain reaction is a useful tool for the diagnosis of Leptospira-induced ocular complications, which are probably misdiagnosed if based only on routine laboratory tests. It enables early diagnosis and early specific treatment that now consists of quinolone and cyclines.

Adult↗

Identification and characterization of the protein antigens of Leptospira interrogans serovar hardjo.

We radiolabeled Leptospira proteins with [35S]methionine. Solubilized extracts of radiolabeled L. interrogans serovar hardjo strain hardjoprajitno were analyzed by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. We compared the protein profile obtained in this manner to the protein profiles of various [35S]methionine-labeled Leptospira spp. The profiles of the pathogenic L. interrogans strains were very similar but not identical and exhibited no obvious relationship to those of the two nonpathogenic species. We used solubilized, radiolabeled hardjoprajitno extracts and a sensitive radioimmunoprecipitation procedure to identify protein antigens recognized by immunoglobulin G antibodies present in various rabbit anti-hardjo sera. Homologous hyperimmune rabbit serum efficiently precipitated a large subset of proteins, the majority of which were between 30,000 and 66,500 daltons. Radioimmunoprecipitations with sera prepared against each of four recent hardjo isolates cultured from infected cattle produced similar results. Immunoprecipitations done with various radiolabeled Leptospira extracts and anti-hardjoprajitno serum demonstrated that the pathogenic leptospires possessed a number of cross-reactive major and minor protein antigens. By cell fractionation procedures, we found that most of the major protein antigens were present in the outer envelope. These proteins were exposed on the leptospiral cell surface because intact radiolabeled leptospires bound antibodies directed against them.

Antigens, Bacterial↗

Metabolic sequelae of experimental leptospirosis in grivet monkeys.

Leptospira interrogans serovars balcanica and tarassovi both induced mild subclinical infections in grivet monkeys. The activities in serum of lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and creatine phosphokinase and the level of alpha 1-antichymotrypsin increased in a few days after infection. Concomitant decreases in serum iron levels were observed in some cases. These changes occurred in the absence of any observable clinical signs though there were histopathological lesions in some organs. No haematological changes or alterations in other sreum components were detected.

Alanine Transaminase↗

Prevalence of pseudorabies virus infection and associated infections in six large swine herds in Illinois.

Sera were collected from 6 large farrow-to-finish swine herds infected with pseudorabies virus (PRV) in Illinois. All herds were participating in the Large Herd Cleanup Study, a USDA-initiated project to evaluate the feasibility of eradicating pseudorabies from large farms (greater than 400 sows) by use of a combination of vaccination and management changes. Herd size ranged between 425 and 1,500 breeding females. Between April and July 1990, sera for measurement of PRV antibodies were obtained from 113 to 156 sows and 112 to 162 finishing pigs (body weight greater than 70 kg)/herd. Duplicate sera from 30 sows and 30 market-weight pigs/herd were obtained for measurement of serum antibodies to the following associated organisms: swine influenza virus, transmissible gastroenteritis virus, encephalomyocarditis virus, Actinobacillus pleuropneumoniae, Eperythrozoon suis, and 6 serovars of Leptospira interrogans. Prevalence of PRV antibodies attributable to field virus infection ranged between 53.8 and 100% for sows and between 0.7 and 97.3% for finishing pigs, as determined by the appropriate differential test for the vaccine being used on each farm. In only 1 herd, PRV seroprevalence was increased with higher sow parity. For associated infections, the risk of seropositivity attributable to PRV was not significant (for most infections) on all farms and varied among farms. Thus, pseudorabies did not appear, in general, to increase susceptibility to infection with other disease agents.

Animals↗

Diagnosis and seroprevalence of leptospirosis in California sea lions from coastal California.

The sensitivity and specificity of the microscopic agglutination test (MAT) as a method for detection of exposure to Leptospira spp. in California sea lions (Zalophus californianus) were determined. Sera came from individuals that demonstrated clinical signs of renal disease, had lesions suggestive of leptospirosis at necropsy, and had visible leptospires in silver stained kidney sections as positive controls. Sera from unexposed captive individuals were used as negative controls. The test was 100% sensitive at 1:3,200 for confirming renal infection and 100% specific at negative < 1:100 for detection of Leptospira interrogans scrovar pomona antibodies by MAT in California sea lions. Leptospira interrogans serovar pomona was used as a screening serovar because it has been isolated previously from the kidneys and placentas of California sea lions, and there appears to be cross-reactivity between serovar pomona and other serovars. Sera from 225 free-ranging California sea lions presented to one of three participating California (USA) coastal marine mammal rehabilitation centers in 1996 were then evaluated for antibodies to serovar pomona using the MAT. The overall seroprevalence was 38.2% (86/225), although the prevalence varied among locations from 100% (38/38) in animals at the Marine Mammal Care Center (Fort MacArthur, California, USA) to 0% (0/14) at SeaWorld California (San Diego, California). At The Marine Mammal Center (Sausalito, California) [prevalence 27.8% (48/173)], the majority of seropositive animals were subadults and adults, and males were 4.7 times more likely to be seropositive to serovar pomona than females. When combining results from all three centers, subadult and adult animals were more likely to be seropositive than pups and juvenile sea lions, and the highest proportion of seropositive animals presented during the autumn months. Serum elevations of blood urea nitrogen, creatinine, phosphorus, and/or calcium were associated with seropositivity to serovar pomona. We found no association between potassium or sodium levels and seropositivity.

Agglutination Tests↗

Disease survey of free-ranging grey brocket deer (Mazama gouazoubira) in the Gran Chaco, Bolivia.

Samples from 17 free-ranging hunter-killed grey brocket deer (Mazama gouazoubira) in the Gran Chaco, Bolivia, were collected during June-August 1999. All 17 deer appeared to be in good condition at the time of death. Gross necropsies were performed, serum was collected for serologic evaluation of selected infectious disease agents, and feces and ectoparasites were collected for evaluation of internal and external parasites. Serologic tests were positive for antibodies against bovine respiratory syncytial virus and four Leptospira interrogans serovars, with questionable results for epizootic hemorrhagic disease virus serotypes 1 and 2. No antibodies were detected to Anaplasma marginale, Babesia bigemina, Babesia bovis, Babesia odocoilei, bluetongue virus (serotypes 2, 10, 11, 13, and 17), bovine viral diarrhea virus, Brucella abortus, foot-and-mouth disease virus, infectious bovine rhinotracheitis virus, Mycobacterium avium subsp. paratuberculosis, and parainfluenza-3 virus. Sixty-four percent (7/11) of the deer had endoparasites. Amblyomma spp. ticks were found on seven deer, flies of the family Hippoboscidae on six deer, and lice on six deer.

Animals↗

Unique physiological and pathogenic features of Leptospira interrogans revealed by whole-genome sequencing.

Leptospirosis is a widely spread disease of global concern. Infection causes flu-like episodes with frequent severe renal and hepatic damage, such as haemorrhage and jaundice. In more severe cases, massive pulmonary haemorrhages, including fatal sudden haemoptysis, can occur. Here we report the complete genomic sequence of a representative virulent serovar type strain (Lai) of Leptospira interrogans serogroup Icterohaemorrhagiae consisting of a 4.33-megabase large chromosome and a 359-kilobase small chromosome, with a total of 4,768 predicted genes. In terms of the genetic determinants of physiological characteristics, the facultatively parasitic L. interrogans differs extensively from two other strictly parasitic pathogenic spirochaetes, Treponema pallidum and Borrelia burgdorferi, although similarities exist in the genes that govern their unique morphological features. A comprehensive analysis of the L. interrogans genes for chemotaxis/motility and lipopolysaccharide synthesis provides a basis for in-depth studies of virulence and pathogenesis. The discovery of a series of genes possibly related to adhesion, invasion and the haematological changes that characterize leptospirosis has provided clues about how an environmental organism might evolve into an important human pathogen.

Bacterial Adhesion↗

Identification of Leptospira species in the pathogenesis of uveitis and determination of clinical ocular characteristics in south India.

Uveitis is considered a rare complication of leptospirosis. This report describes an epidemic of uveitis among patients with leptospirosis and provides data, using polymerase chain reaction (PCR) amplification of Leptospira DNA, that the pathogenesis is associated with anterior chamber spirochetes. Forty-six uveitis patients, 49 uveitis controls, and 54 cataract controls were enrolled at Aravind Eye Hospital (Madurai, India). Leptospiral DNA was detected by PCR of aqueous humor; serum antibody titers were determined by ELISA and microagglutination (MAT). Thirty-seven uveitis patients (80%) demonstrated leptospiral DNA compared with 5 controls (8%; P < .001). Thirty-three uveitis patients (72%) had positive serology compared with 10 uveitis controls (20%) and 13 cataract controls (24%; P < .001). This report describes the largest cluster of patients with leptospiral uveitis and identifies six clinical characteristics that provide a diagnostic profile for leptospiral uveitis. This profile will be important for determining treatment regimens in countries where PCR and MAT are not available.

Adolescent↗

[Detection of leptospira in the vitreous body of horses without ocular diseases and of horses with equine recurrent uveitis (ERU) using transmission-electron microscopy].

Equine recurrent uveitis (ERU) is caused by persistent intraocular leptospira, which appear to use the vitreous body as a refuge. The detection of leptospira in the vitreous body of horses with spontaneous ERU by histological methods has not yet been described. Thirty eight vitreous body samples from 36 horses with ERU (collected during vitrectomy), and 10 vitreous body samples obtained from 5 horses without ocular disease (control group) were examined by transmission electron microscopy. Prior to sample collection, 2 ml of a leptospira culture suspension were injected into the vitreous body of 2 eyes enucleated from horses of the control group. The detection of leptospira in samples, experimentally inoculated with these bacteria was uncomplicated; in vitreous body samples from horses with spontaneous ERU the detection was successful in only a few cases (3/38). The morphologically varying envelope of leptospira in vitreous body samples of horses which developed ERU spontaneously suggests the existence of a bacterial masquerade in vivo.

Animals↗