Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
103
result(s) for
"Langoni, Hélio"
Sort by:
Spatial serosurvey of anti-Toxoplasma gondii antibodies in individuals with animal hoarding disorder and their dogs in Southern Brazil
by
Langoni, Hélio
,
Cunha, Graziela Ribeiro da
,
Yamakawa, Ana Carolina
in
Antibodies
,
Biology and Life Sciences
,
Blood
2020
Despite vulnerability and unsanitary conditions of animal hoarding may predispose environmental contamination and spread of vectors and pathogens, no study to date has focused on their impact on public health and zoonotic diseases. Accordingly, this study aimed to assess the seroprevalence of anti-Toxoplasma gondii antibodies and associated factors in individuals with animal hoarding disorder (AHD) and their dogs in Curitiba, Southern Brazil. Blood samples were obtained from 264 dogs (21 households) and 19 individuals with AHD (11 households). Their blood was tested by indirect fluorescent antibody test (IFAT). Overall, anti-Toxoplasma gondii seropositivity was found in 21/264 dogs (7.95%; 95% CI: 4.69-11.22) with titers ranging from 16 to 4096, and in 7/19 individuals with AHD (36.84%; CI: 15.15-58.53) with titers ranging from 16 to 64. Serological analysis for anti-T. gondii antibodies were considered positive in at least one individual or dog in 9/11 (81.82%; 95% CI: 59.03-100.00) cases that were thoroughly assessed. Surprisingly, the seropositivity of individuals with AHD and their dogs was among the lowest reportedly observed in human and dog populations of Brazil. There was no significant association between positive owners and positive dogs or the presence of cats in the household. Regard epidemiological variables, a significant association was found between dog's seropositivity and the type of dog food. To the authors' knowledge, the present study represents the first investigation of T. gondii seroprevalence in individuals with hoarding disorder and their dogs. In conclusion, despite low sanitary conditions, anti-Toxoplasma gondii antibodies frequency in individuals with AHD and their dogs are lower than the general population likely due to low protozoan load in such isolated households.
Journal Article
The Emergence of Antimicrobial Resistance and Virulence Characteristics in Enterococcus Species Isolated from Bovine Milk
by
Langoni, Hélio
,
Gebara, Clarice
,
Paschoalini, Beatriz Rizzo
in
Antibiotics
,
Antimicrobial agents
,
Antimicrobial resistance
2023
Enterococcus spp., including E. faecalis and E. faecium, pose risks to dairy farms as opportunistic pathogens. The study evaluates antimicrobial resistance (AMR) and virulence characteristics of Enterococcus spp. isolated from bovine milk. Bile esculin agar was used to assess 1471 milk samples, followed by colony identification, gram staining, catalase tests, and 45 °C incubation. PCR analysis targeted E. faecalis and E. faecium in characteristic Enterococcus spp. colonies, with MALDI-TOF used for negative samples. Multiple tests, including disk diffusion, chromogenic VRE agar for vancomycin resistance, Vancomycin Etest® for MIC determination, and PCR for virulence factors (cylA, esp, efaA, ace, asa1, gelE, and hyl genes), were performed. Out of 100 identified strains, E. durans (30.66%), E. faecium (26.28%), and E. faecalis (18.25%) were predominant. AMR in Enterococcus spp. varied, with the highest rates against rifampicin (27%), tetracycline (20%), and erythromycin (18%). Linezolid (5%), vancomycin, ciprofloxacin, and teicoplanin (3% each) had lower prevalence. E. faecium and E. faecalis showed high AMR to rifampicin, erythromycin, and tetracycline. Thirty-two strains (18.98%) grew on VRE Chromoselect agar, while 4 (2 E. faecalis and 2 E. faecium) showed vancomycin resistance by MIC values. E. faecalis carried gelE (45.5%) and asa1 (36%), and E. gallinarum had 9.1% with the asa1 gene. Detecting resistant Enterococcus in bovine milk supports control strategies for enterococci on dairy farms, highlighting AMR concerns in the food chain.
Journal Article
Genetic and histopathological characterization of Toxoplasma gondii genotypes isolated from free-range chickens reared in the metropolitan region of Rio de Janeiro state, Brazil
by
Casartelli-Alves, Luciana
,
de Macedo Couto, Rodrigo
,
Langoni, Hélio
in
Bioassays
,
Dyspnea
,
Gene polymorphism
2021
This study aimed to genetically characterize Toxoplasma gondii isolates obtained from free-range chickens reared in the metropolitan region of the state of Rio de Janeiro, Brazil, and to evaluate the morbidity and histological changes associated with these isolates in mice. A mouse bioassay was used to isolate T. gondii from a pool of tissue samples (brain, heart, and thigh muscles) collected from 163 chickens. The 36 isolates obtained were genetically characterized by restriction fragment polymorphism (PCR-RFLP) analysis of the SAG1, 5′-3′SAG2, aSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3 genomic regions. Seventeen atypical genotypes were identified and nine of them were reported for the first time. All identified genotypes caused clinical signs and histological changes in mice, with the majority being associated with high cumulative morbidity (65%) and severe or very severe histological changes (76%). The exclusive identification of atypical genotypes, with a predominance of new genotypes, indicates great genetic diversity of T. gondii in the region studied. In addition, the finding that all identified genotypes caused clinical signs and often severe histological changes in mice suggests potentially relevant virulence of these strains.
Journal Article
Seropositivity of anti-'Toxoplasma gondii' antibodies in owners and their dogs living on Island and mainland seashore areas of Southern Brazil
by
Aaronson Ramathan Freitas
,
Andrea Pires Dos Santos
,
Alexander Welker Biondo
in
Antibodies
,
Brazil
,
Diagnosis
2022
Although toxoplasmosis has been considered among the most neglected zoonoses worldwide, no study has focused on the frequency and associated risk factors of owners and their dogs living on an island and mainland seashore areas. Accordingly, anti-'Toxoplasma gondii' IgG antibodies were screened by indirect fluorescent antibody test (IFAT) in owners and dogs from three oceanic islands and two nearby mainland harbor areas, with associated risk factors for toxoplasmosis assessed by univariable and multivariable logistic regression models. Overall, anti-T. gondii seropositivity was observed in 59/328 (18.0%) owners and 66/283 (23.3%) dogs, with no statistical difference between owners (p = 0.360) and dogs (p = 0.655) from islands and mainland areas. Consumption of local water springs (p = 0.016; OR = 2.11) was an associated risk factor for 'T. gondii' seropositivity, and owners with the habit of spring water intake were twice more likely seropositive (p = 0.014; OR = 2.14). Presence of anti-'T. gondii' antibodies in dogs was associated with seropositive owners (p = 0.008; OR = 2.81), household consumption of beef meat (p = 0.042; OR = 1.7) and chicken (p = 0.026; OR = 2.9). Despite being lower than the worldwide prevalence, toxoplasmosis seropositivity in owners and their dogs in southern Brazil was influenced by the positive owner, water source, and meat consumption, and not by inhabiting islands or seashore mainland areas, presence of dogs, cats, or both. In addition, drinking water quality should always be considered a critical risk factor for toxoplasmosis on islands.
Journal Article
Feasibility of replacing the viral isolation technique in mice with RT-qPCR for the diagnosis of rabies
by
Magalhães Júnior, Cássio Alexandre Costa
,
Tobias, Fernando Luiz
,
Langoni, Hélio
in
AGRONOMY
,
Bats
,
Brain
2024
Rabies is a viral encephalitis that affects mammals, including humans. Rapid and effective laboratory diagnosis of the rabies virus is critical for public health. This study evaluated the operational, technical, and financial viability of the RT-qPCR in replacement of inoculation in mice for diagnosing rabies in the laboratory routine. A total of 316 samples of mammalian brains were analyzed, 121 positives and 195 negatives, previously diagnosed by direct immunofluorescence (DIF) and mouse inoculation test (MIT). The samples were submitted to the duplex TaqMan RT-qPCR technique. The accuracy, sensitivity, and specificity of RT-qPCR were analyzed. We analyzed the costs for performing the RT-qPCR technique and compared it with the cost of MIT. The results showed 99.37% accuracy, 99.17% sensitivity, and 99.49% specificity by RT-qPCR when related to DIF and MIT results, which proved to be a robust and repeatable technique. The minimum time for a positive diagnosis was reduced in RT-qPCR (1 day) if compared to MIT (9.64 days), with a 17.7% reduction in the cost of the molecular technique. The present study demonstrated that the molecular biology technique is an efficient tool to diagnose rabies in the laboratory routine, being able to replace MIT. RESUMO: A raiva é uma encefalite viral que acomete os mamíferos, incluindo humanos. O diagnóstico laboratorial rápido e eficaz do vírus da raiva é importante para a saúde pública. Este estudo teve como objetivo avaliar a viabilidade operacional, técnica e financeira da RT-qPCR em substituição à inoculação em camundongos para o diagnóstico da raiva na rotina laboratorial. Foram analisadas 316 amostras de cérebros de mamíferos, 121 positivas e 195 negativas, previamente diagnosticadas por imunofluorescência direta (IFD) e isolamento viral em camundongos, por inoculação intracerebral em camundongos. As amostras foram submetidas à técnica duplex TaqMan RT-qPCR. A precisão, sensibilidade e especificidade da RT-qPCR foram analisadas. Os custos para realizar a técnica de RT-qPCR foram analisados e comparados com o custo do isolamento viral em camundongos. Os resultados demostraram 99,37% de acurácia, 99,17% de sensibilidade e 99,49% de especificidade pela RT-qPCR quando relacionada aos resultados de IFD e isolamento viral em camundongos, que se mostrou uma técnica robusta e com repetibilidade. O tempo mínimo para diagnóstico positivo foi reduzido na RT-qPCR (1 dia) quando comparado ao isolamento viral em camundongos (9,64 dias), e com redução de 17,7% no custo pela técnica molecular. O presente estudo demonstrou que a técnica de biologia molecular é uma ferramenta eficiente para o diagnóstico da raiva na rotina laboratorial, podendo substituir o isolamento viral em camundongos.
Journal Article
Seroprevalence of anti-Toxoplasma gondii antibodies in wild boars (Sus scrofa), hunting dogs, and hunters of Brazil
by
de Barros-Filho, Ivan Roque
,
Langoni, Hélio
,
Yamakawa, Ana Carolina
in
Agglutination
,
Agricultural land
,
Analysis
2019
Seroprevalence of Toxoplasma gondii has been extensively studied in wild boars worldwide due to the emerging risk for human infection through meat consumption. However, this is the first study that reports toxoplasmosis seroprevalence in wild boars, wild boar hunters and their hunting dogs. The aim of the present study was to evaluate the seroprevalence of anti-T. gondii antibodies in the complex wild boars, hunting dogs and hunters, and to determine the risk factors associated with seropositivity in southern and central-western Brazil. Overall, anti-T. gondii seropositivity was observed in 15/71 (21.1%) wild boars by modified agglutination test (MAT); and 49/157 (31.2%) hunting dogs and 15/49 (32.7%) hunters by indirect immunofluorescent antibody test (IFAT). Seroprevalence of toxoplasmosis in Brazilian wild boars was within the national and international range, posting wild boars as potential environmental sentinels for T. gondii presence. In addition, the findings have comparatively shown that wild boars have been less exposed to infection than hunting dogs or hunters in both Brazilian regions. Seropositivity for T. gondii was statistically higher in 12/14 (85.7%) captured wild boars when compared to 5/57 (7.0%) free-range wild boars (p = 0.000001). Similarly, captured wild boars from anthropized areas were more likely to be seropositive than of natural regions (p = 0.000255). When in multiple regression model, dogs with the habit of wild boar hunting had significant more chance to be positive (adjusted-OR 4.62 CI 95% 1.16-18.42). Despite potential as sentinels of environmental toxoplasmosis, seroprevalence in wild boars alone may provide a biased basis for public health concerns; thus, hunters and hunting dogs should be always be included in such studies. Although hunters should be aware of potential T. gondii infection, wild boars from natural and agricultural areas may present lower protozoa load when compared to wild boars from anthropized areas, likely by the higher presence of domestic cats as definitive hosts.
Journal Article
First investigation of Staphylococcus argenteus in a Brazilian collections of S. aureus isolated from bovine mastitis
by
Dantas, Stéfani T. A.
,
Rall, Vera L. M.
,
Langoni, Hélio
in
agar
,
Animals
,
Bacteriology and mycology
2020
Background
Staphylococcus argenteus
is a new specie positive coagulase staphylococci. We investigate the presence of
S. argenteus
in isolates previously classified as
S. aureus,
obtained from the milk of cows with mastitis in Brazil.
Results
Among 856
S. aureus
tested in chocolate agar, tryptone soya agar and salt egg yolk agar, white or colorless colonies were observed in 185 (21.6%) isolates. Regarding the
ctrOPQMN
operon, 111 (60%) presented the complete cluster. Despite some missing genes in this cluster, the remaining strains (74) were confirmed as
S. aureus
using the
nrps
gene.
Conclusions
As far as we know, this is the first review of
S. aureus
collection in Brazil and
S. argenteus
does not appear to be a significant problem in Brazilian herds.
Journal Article
Serological survey of anti‐Leptospira spp. antibodies in individuals with animal hoarding disorder and their dogs in a major city of Southern Brazil
by
Langoni, Hélio
,
Cunha, Graziela Ribeiro da
,
Yamakawa, Ana Carolina
in
Agglutination
,
Animals
,
Antibodies
2022
Background Individuals with hoarding disorder (HD) presented a persistent difficulty in detaching from objects and/or animals. Unhealthy conditions, frequently found in cases of animal HD (AHD), may favour environmental contamination and the spread of zoonotic pathogens. Despite that, only one study of zoonotic diseases in individuals with AHD and their companion animals has been conducted to date. Objectives This study aimed to assess the seroprevalence of anti‐Leptospira spp. antibodies in individuals with AHD and their dogs in a major city of Southern Brazil. Methods Blood samples were obtained from 264 dogs (21 households) and 19 individuals with AHD (11 households) and tested by microscopic agglutination test. Results All human samples were seronegative. Seropositivity was found in 16/264 (6.1%; CI 95% 3.3–9.6%) dogs from 11/21 (52.38%) households, with titres ranging from 100 up to 400, and Copenhageni (10/16; 62.5%) was the most frequent serovar. Surprisingly, seropositivity of hoarded dogs found herein was among the lowest reportedly observed in other dog populations of Brazil. Two epidemiological variables were significantly associated with seropositivity in dogs: the presence of cat hoarding (p = 0.004) and the report of flood occurrence in the household (p = 0.031). Conclusions No individuals with AHD were seropositive, and besides the lower seroprevalence of dogs, they probably had contact with Leptospira spp. at some point in their life. Since dogs can be considered potential sentinels in leptospirosis, public health programs must become aware of the risk of leptospirosis cases in households of individuals with AHD and nearby communities. To the author's knowledge, this is the first report of Leptospira spp. serological status in individuals with animal hoarding disorder and their dogs. Household of individuals with hoarding disorder generally involves unhealthy environmental conditions, which can generate several public health concerns, such as potential transmission and spread of zoonotic pathogens to individuals with hoarding disorder, their pets and the surrounding community. The One Health approach is essential in understanding the epidemiology of infectious diseases, such as leptospirosis. Serological surveys of dogs in hoarding situations may help develop policies and public health campaigns to prevent human cases of leptospirosis.
Journal Article
Concentrations of Acute-Phase Proteins in Milk from Cows with Clinical Mastitis Caused by Different Pathogens
by
Langoni, Hélio
,
Guerra, Simoni T.
,
Lopes, Bruna C.
in
Acute phase proteins
,
Amyloid
,
Bacteria
2020
Among the new diagnostic methods for mastitis detection under development, milk acute-phase proteins (APPs) are receiving special attention. The study aimed to compare the profile of milk APPs from cows with natural clinical mastitis caused by distinct pathogens. The concentrations of haptoglobin (Hp), serum amyloid A (SAA), alpha-1-acid glycoprotein (AGP), and C-reactive protein (CRP) were measured by Spatial Proximity Analyte Reagent Capture Luminescence (SPARCL). Each APP was compared across the pathogens causing mastitis. The APPs differed statistically (p < 0.05) among the pathogens causing udder infection. There were significant and positive correlations among the concentration profile, for each pathogen, in three of four APPs studied. It can be concluded that the pathogen causing mastitis could modify the profile of release of the APPs in milk. The profile of Hp, AGP, and CRP demonstrated significant correlation, indicating that the three APPs are suggested as biomarkers, in milk, for bovine mastitis.
Journal Article