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author:("quero, adrian")
1.  Association between an Emerging Disseminated form of Leishmaniasis and Leishmania (Viannia) braziliensis Strain Polymorphisms 
Journal of Clinical Microbiology  2012;50(12):4028-4034.
Leishmania (Viannia) braziliensis causes three main types of American tegumentary leishmaniasis (ATL), localized cutaneous leishmaniasis (CL), mucosal leishmaniasis (ML), and disseminated leishmaniasis (DL). All forms are observed among individuals of Corte de Pedra, Brazil. We previously used random amplified markers to identify a multiclonal population among L. (V.) braziliensis isolates from ATL patients, defining parasite clades associated with different clinical syndromes. Herein we compared sequences of random amplified markers to identify genotypes of L. (V.) braziliensis recovered from lesions of CL, ML, and DL patients. Six polymorphic genomic loci were sequenced from 35 parasite isolates. Single-nucleotide polymorphisms (SNPs) and insertions-deletions (indels) at each locus allowed us to segregate the L. (V.) braziliensis population according to haplotypes. Several SNPs, indels, and haplotypes were significantly associated with an increased risk of DL. Molecular genotyping may provide markers to identify L. (V.) braziliensis strains likely to cause this emerging, hard-to-treat form of ATL.
doi:10.1128/JCM.02064-12
PMCID: PMC3503016  PMID: 23035200
2.  Monitoring Leptospira Strain Collections: The Need for Quality Control 
The purpose of this study was to perform a 16S sequence-based quality control of two Leptospira strain collections. 16S rRNA gene sequencing was used to verify two Leptospira reference collections provided by the World Health Organization and maintained at a reference laboratory for leptospirosis in Brazil. Among the 89 serovars evaluated, four conflicting strains were identified in one of the collections. Although 16S rRNA gene sequencing cannot identify Leptospira beyond the species level, it is suitable for the identification of contamination and quality control of leptospiral reference collections. This study highlights the importance of the availability of high-quality 16S rRNA sequences in public databases. In addition, it emphasizes the need for periodical verifications and quality control of Leptospira reference collections.
doi:10.4269/ajtmh.2010.09-0558
PMCID: PMC2803514  PMID: 20065000
3.  Leptospira noguchii and Human and Animal Leptospirosis, Southern Brazil 
Emerging Infectious Diseases  2009;15(4):621-623.
doi:10.3201/eid1504.071669
PMCID: PMC2671420  PMID: 19331754
Zoonoses; Leptospira noguchii; leptospirosis; isolation; taxonomy; letter
4.  Impact of Environment and Social Gradient on Leptospira Infection in Urban Slums 
Background
Leptospirosis has become an urban health problem as slum settlements have expanded worldwide. Efforts to identify interventions for urban leptospirosis have been hampered by the lack of population-based information on Leptospira transmission determinants. The aim of the study was to estimate the prevalence of Leptospira infection and identify risk factors for infection in the urban slum setting.
Methods and Findings
We performed a community-based survey of 3,171 slum residents from Salvador, Brazil. Leptospira agglutinating antibodies were measured as a marker for prior infection. Poisson regression models evaluated the association between the presence of Leptospira antibodies and environmental attributes obtained from Geographical Information System surveys and indicators of socioeconomic status and exposures for individuals. Overall prevalence of Leptospira antibodies was 15.4% (95% confidence interval [CI], 14.0–16.8). Households of subjects with Leptospira antibodies clustered in squatter areas at the bottom of valleys. The risk of acquiring Leptospira antibodies was associated with household environmental factors such as residence in flood-risk regions with open sewers (prevalence ratio [PR] 1.42, 95% CI 1.14–1.75) and proximity to accumulated refuse (1.43, 1.04–1.88), sighting rats (1.32, 1.10–1.58), and the presence of chickens (1.26, 1.05–1.51). Furthermore, low income and black race (1.25, 1.03–1.50) were independent risk factors. An increase of US$1 per day in per capita household income was associated with an 11% (95% CI 5%–18%) decrease in infection risk.
Conclusions
Deficiencies in the sanitation infrastructure where slum inhabitants reside were found to be environmental sources of Leptospira transmission. Even after controlling for environmental factors, differences in socioeconomic status contributed to the risk of Leptospira infection, indicating that effective prevention of leptospirosis may need to address the social factors that produce unequal health outcomes among slum residents, in addition to improving sanitation.
Author Summary
Leptospirosis, a life-threatening zoonotic disease, has become an important urban slum health problem. Epidemics of leptospirosis now occur in cities throughout the developing world, as the growth of slum settlements has produced conditions for rat-borne transmission of this disease. In this prevalence survey of more than 3,000 residents from a favela slum community in Brazil, Geographical Information System (GIS) and modeling approaches identified specific deficiencies in the sanitation infrastructure of slum environments—open sewers, refuse, and inadequate floodwater drainage—that serve as sources for Leptospira transmission. In addition to the environmental attributes of the slum environment, low socioeconomic status was found to independently contribute to the risk of infection. These findings indicate that effective prevention of leptospirosis will need to address the social factors that produce unequal health outcomes among slum residents, in addition to improving sanitation.
doi:10.1371/journal.pntd.0000228
PMCID: PMC2292260  PMID: 18431445
5.  Isolation of Leptospira noguchii from sheep 
Veterinary microbiology  2006;121(1-2):144-149.
The main goal of this study was to obtain new isolates of Leptospira spp. from sheep. A total of ten kidney samples and 44 blood samples were collected from sheep slaughtered in Pelotas, Southern Brazil. One isolate was obtained which was identified by 16S rRNA gene sequencing and serogrouping to be Leptospira noguchii serogroup Autumnalis. Microscopic agglutination test (MAT) evaluation revealed that 4.5% of the sheep sera reacted against the Autumnalis serogroup. This is the first report of isolation of L. noguchii from sheep. Together these findings indicate that L. noguchii infections may be a potentially important veterinary problem in this domestic animal species.
doi:10.1016/j.vetmic.2006.11.010
PMCID: PMC1868676  PMID: 17222993
leptospirosis; Leptospira noguchii; isolation; serogrouping; sheep; Brazil
6.  High serum nitric oxide levels in patients with severe leptospirosis 
Acta tropica  2007;100(3):256-260.
Leptospirosis is a globally distributed zoonosis of major public health importance and is associated with severe disease manifestations such as acute renal failure and pulmonary haemorrhage syndrome. However, the extent to which the pathogenesis of leptospirosis mimics sepsis caused by Gram-negative bacteria remains unknown. The aim of this study was to evaluate serum levels of nitric oxide (NO) in patients diagnosed with severe leptospirosis. Sera from 35 confirmed cases of severe leptospirosis and 13 healthy subjects were analysed. Patients with severe leptospirosis had significantly higher NO levels compared to healthy individuals (30.82 ± 10.90 μM versus 3.86 ± 1.34 μM, P<0.001), indicating that this immune mediator plays a role in the underlying systemic inflammatory response.
doi:10.1016/j.actatropica.2006.11.006
PMCID: PMC1805659  PMID: 17196920
Leptospirosis; Nitric Oxide; Acute renal failure; Pulmonary haemorrhage
7.  Evaluation of Four Whole-Cell Leptospira-Based Serological Tests for Diagnosis of Urban Leptospirosis▿  
Four serologic assays for leptospirosis had sensitivities of 72 to 88% and specificities of 88 to 100% in the setting of highly endemic urban transmission, indicating that assays using enzyme-linked immunosorbency and rapid formats may be used as alternatives to the microscopic agglutination test for diagnosing urban leptospirosis. Testing a second sample will be required in cases with an initial negative result, since sensitivity was low (46 to 68%) during the first week of illness.
doi:10.1128/CVI.00217-07
PMCID: PMC2043306  PMID: 17652521
8.  Leptospira Immunoglobulin-Like Proteins as a Serodiagnostic Marker for Acute Leptospirosis▿  
Journal of Clinical Microbiology  2007;45(5):1528-1534.
There is an urgent need for improved diagnosis of leptospirosis, an emerging infectious disease which imparts a large disease burden in developing countries. We evaluated the use of Leptospira immunoglobulin (Ig)-like (Lig) proteins as a serodiagnostic marker for leptospirosis. Lig proteins have bacterial immunoglobulin-like (Big) tandem repeat domains, a moiety found in virulence factors in other pathogens. Sera from patients identified during urban outbreaks in Brazil reacted strongly with immunoblots of a recombinant fragment comprised of the second to sixth Big domains of LigB from L. interrogans serovar Copenhageni, the principal agent for transmission in this setting. Furthermore, the sera recognized an analogous LigB fragment derived from L. kirschneri serovar Grippotyphosa, a pathogenic serovar which is not endemic to the study area. The immunoblot assay detected anti-LigB IgM antibodies in sera from 92% (95% confidence interval, 85 to 96%) of patients during acute-phase leptospirosis. The assay had a sensitivity of 81% for sera from patients with less than 7 days of illness. Anti-LigB antibodies were found in sera from 57% of the patients who did not have detectable anti-whole-Leptospira responses as detected by IgM enzyme-linked immunosorbent assay and microagglutination test. The specificities of the assay were 93 to 100% and 90 to 97% among sera from healthy individuals and patients with diseases that have clinical presentations that overlap with those of leptospirosis, respectively. These findings indicate that the antibody response to this putative virulence determinant is a sensitive and specific marker for acute infection. The use of this marker may aid the prompt and timely diagnosis required to reduce the high mortality associated with severe forms of the disease.
doi:10.1128/JCM.02344-06
PMCID: PMC1865864  PMID: 17360842

Results 1-8 (8)