Thomas Salles Dias

Prof. Dr. Thomas Salles Dias

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Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 December 2020 in British Poultry Science
Verified
Journal Article
Closed access
TDThomas Salles Dias
Thomas Salles Dias
RNR. J. Nascimento
R. J. Nascimento
LML. S. Machado
L. S. Machado
DADayse Lima da Costa Abreu
Dayse Lima da Costa Abreu
ENE. R. Do Nascimento
E. R. Do Nascimento
MAM. H. C. de Aquino
M. H. C. de Aquino
1. The aim of this study was to compare the resistance pattern of thermophilic Campylobacter spp. isolated from conventional production (n = 34) and backyard poultry flocks (n = 36) from Rio de Janeiro State, Brazil. The disc diffusion method and statistical tests were used for investigation and analysis of the resistance pattern of Campylobacter spp. isolated from different rearing systems. 2. Antimicrobial resistance percentages to amoxycillin with clavulanic acid (AMC), ampicillin (AMP), ceftiofur (CTF), ciprofloxacin (CIP), enrofloxacin (ENO), erythromycin (ERI), gentamicin (GEN) and tetracycline (TET) were 32.4%, 44.1%, 67.6%, 97.1%, 82.4%, 26.5%, 5.9% and 38.2% in conventional production flocks respectively, while the backyard flock’s resistance levels were 0.0%, 13.9%, 69.4%, 100.0%, 91.7%, 5.6%, 0.0% and 16.7%, respectively. 3. Campylobacter spp. from conventional poultry production was more resistant to AMC, AMO, ERI and TET (P > 0.05) when compared to strains from backyard poultry. A higher frequency of resistance to fluoroquinolones (FLQ), CIP and ENO, was observed in strains from both systems, demonstrating the spread of resistant strains among poultry production environments.

6 June 2022 in Research, Society and Development
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Journal Article
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ASAndré Felipe das Mercês Santos
André Felipe das Mercês Santos
LALaura Fabiana Vieira Amparo
Laura Fabiana Vieira Amparo
SMSimone Costa Alves Machado
Simone Costa Alves Machado
TDThomas Salles Dias
Thomas Salles Dias
LBLucia Helena Berto
Lucia Helena Berto
VPVirginia Léo de Almeida Pereira
Virginia Léo de Almeida Pereira
Salmonella is one of the major foodborne pathogens worldwide. Domestic, wild animals, and a variety of food matrices can transmit Salmonella spp. to humanS. Here, we report the top 10 Salmonella serovars isolated from human sources between 2011 and 2020 and received in the National Reference Laboratory for Enteric DiseaseS. Serotyping was performed according to the Kauffman-White scheme. 3113 isolates related to human cases belonging to 61 serogroups were received in the NRL between 2011 and 2020. The purpose of this article is the identification of circulating serotypes as the first step to understanding the epidemiology, and then, with this information, take actions to mitigate and control this pathogen.

1 March 2020 in Pesquisa Veterinária Brasileira
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Journal Article
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BMBárbara S.N. Magalhães
Bárbara S.N. Magalhães
VPVirginia Léo A. Pereira
Virginia Léo A. Pereira
TDThomas Salles Dias
Thomas Salles Dias
LMLeandro S. Machado
Leandro S. Machado
MSMariane M. Silva
Mariane M. Silva
NANádia Regina P. Almosny
Nádia Regina P. Almosny
Brazil is one of the countries with the most abundant avifauna in the world. The confinement of birds associated with close contact with other animals and humans favor the spread of agents of respiratory diseases. Among them, mycoplasmas can cause asymptomatic or apparent disease that manifests in birds by coughing, sneezing, rales, conjunctivitis, ocular and nasal discharge. Several described mycoplasmas cause disease in birds, especially Mycoplasma gallisepticum(MG) andMycoplasma synoviae(MS). The diagnosis ofMycoplasmaspp. can be done by clinical observation and laboratory analysis. Molecular diagnosis by PCR was boosted by its speed, sensitivity, and low cost of agent isolation techniques that take up to 21 days to complete. This study aimed to verify the occurrence ofMycoplasmaspp. in birds of the Rio de Janeiro Zoo (Rio Zoo), by isolation and PCR. Of the total 635 birds from the Rio Zoo, 81 were studied for detection ofMycoplasmaspp., when taken for routine health assessment exams. These birds belonged to the following orders: Psittaciformes (45), Accipitriformes (18), Galliformes (7), Piciformes (5), Strigiformes (4), Falconiformes (1) and Cariamiformes (1), all individuals already identified by microchip or leg-ring. There was no isolation of mycoplasmas in any of the samples tested, whereas, in the PCR, 62.96% (51/81) were positive, with 1.96% (1/51) identified as MG and 19.61% (10/51) as MS, representing 1.23% (1/81) and 12.34% (10/81) of the total population studied. PCR was shown to be a more effective technique than isolation in the detection ofMycoplasmaspp. in birds. It was possible to detect mycoplasmas in birds from Riozoo with no clinical respiratory signs, with higher MS prevalence than MG. The positivities forMycoplasmaspp., MS, and MG were different among the orders studied, being the highest occurrence in birds of prey, followed by Galliformes and Piciformes. The presence of MG and MS in birds of Rio de Janeiro Zoo confirms the circulation of these agents and the need for further studies on the dissemination of mycoplasmas in zoos for the epidemiological analysis of these bacteria in these places.

1 January 2021 in Ciência Rural
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Journal Article
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BMBarbara Souza Neil Magalhães
Barbara Souza Neil Magalhães
LMLeandro dos Santos Machado
Leandro dos Santos Machado
AFArthur de Almeida Figueira
Arthur de Almeida Figueira
TDThomas Salles Dias
Thomas Salles Dias
TFThiago de Almeida Feijó
Thiago de Almeida Feijó
NANádia Regina Pereira Almosny
Nádia Regina Pereira Almosny
Although rare, mycoplasmas are included among the causes of respiratory diseases in reptiles and, in the order Squamata, three reports of these microorganisms causing diseases in pythons have already been reported. This study aimed to evaluate the occurrence of Mycoplasma species in captive snakes. A total of 26 snakes of the families Pythonidae (13), Boidae (7), Viperidae (5) and Colubridae (1) from RioZoo, Brazil, were evaluated. Animals were examined to determine clinical signs consistent with any infectious disease. Tracheal swab samples from snakes were collected in Frey medium and analyzed for the presence of Mycoplasma spp.by isolation and a genus-specific PCR. DNA sequencing analyses of six positive samples by PCR were carried out to identify the species. Using isolation 19.23% (5/26) was positive, while 65.38% (17/26) of the animals were positive by PCR. Based on the analyses of the six sequences obtained, there was similarity with a Mycoplasma spp. previously described in a phyton and, M. agassizii and M. testudineum reported in chelonians. This is the first report of Mycoplasma spp. in animals of the families Boidae and Viperidae. Mycoplasma spp. were detected in snakes with and without clinical signs. The mycoplasmas reported resented identity (range, 95% to 100%) to others already described in reptiles. There was no relationship between the presence of Mycoplasma spp. and clinical signs.

1 September 2019 in Pesquisa Veterinária Brasileira
Verified
Journal Article
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RNRegina J. Nascimento
Regina J. Nascimento
BFBeatriz S. Frasão
Beatriz S. Frasão
TDThomas Salles Dias
Thomas Salles Dias
ENElmiro R. Nascimento
Elmiro R. Nascimento
LTLouise S.B. Tavares
Louise S.B. Tavares
MAMaria Helena C. Aquino
Maria Helena C. Aquino
Fowls are the main reservoirs of the highly important food-originating pathogen called Campylobacter spp. and broilers’ meat and byproducts are the main vehicles of this microorganism. Increasing of Campylobacter spp. resistant strains to fluorquinolones, an antimicrobial class often employed in poultry farming and in human medicine has become a great concern to poultry breeders. In fact, several studies evaluated increasing bacterial resistance against these antimicrobial agents. The role of CmeABC efflux system has been underscored among the resistance mechanisms in Campylobacter spp. to fluorquinolones. This study investigated the occurrence of CmeABC efflux pump in 81 and 78 enrofloxacin resistant strains of Campylobacter jejuni and C. coli respectively, isolated from broilers collected from six abattoirs situated at São José do Vale do Rio Preto/RJ poultry center and from two commercial abattoirs situated at Metropolitan Region of Rio de Janeiro, from 2013 to 2016. The resistance to enrofloxacin was assessed by agar dilution to determine minimum inhibitory concentration (MIC). The CmeABC efflux system was investigated through the detection of genes genes cmeA, cmeB and cmeC by PCR. The activity of CmeABC efflux pump was investigated in 20 strains by using the efflux pump inhibitor Phenylalanine-Arginine β-Naphthylamide (PAβN). The three genes cmeA, cmeB and cmeC were detected in 94.3% of the strains (C. jejuni = 80 and C. coli = 70), whereas the system was absent or incomplete in 5.7% of strains (C. jejuni = 1 and C. coli = 8). MIC varied between 0.5μg/ml and 64μg/ml, and 88.7% of strains were enrofloxacin resistant and 11.3% featuring intermediate resistance. The inhibition of the efflux pump by PAβN reduced the MIC to enrofloxacin up to eight times in fifteen strains (75%). These results indicate that this system is frequent and active in Campylobacter spp. Resistant strains in the presence of enrofloxacin.

1 August 2020 in Pesquisa Veterinária Brasileira
Verified
Journal Article
Open access
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TDThomas Salles Dias
Thomas Salles Dias
LMLeandro S. Machado
Leandro S. Machado
JVJulia A. Vignoli
Julia A. Vignoli
NCNathalie C. Cunha
Nathalie C. Cunha
ENElmiro R. Nascimento
Elmiro R. Nascimento
MAMaria Helena C. Aquino
Maria Helena C. Aquino
Campylobacter spp. is a bacterial agent that causes gastroenteritis in humans and may trigger Guillain-Barré Syndrome (GBS) and is also considered one of the main foodborne diseases in developed countries. Poultry and pigs are considered reservoirs of these microorganisms, as well as raw or undercooked by-products are often incriminated as a source of human infection. Treatment in human cases is with macrolide, such erythromycin, that inhibits the protein synthesis of the microorganism. This study aimed to isolate Campylobacter jejuni and Campylobacter coli from intestinal content samples of broiler chickens (n=20) and swine (n=30) to characterize the erythromycin resistance profile of the strains and to detect molecular mechanisms involved in this resistance. The minimum inhibitory concentration was determined by agar dilution. The Mismatch Amplification Mutation Assay-Polymerase Chain Reaction (MAMA-PCR) was performed to detect mutations at positions 2074 and 2075 of 23S rRNA region, in addition to PCR test to detect the erm(B) gene. From the intestinal content of broiler chickens, 18 strains of C. jejuni and two strains of C. coli were isolated, whereas, from swine samples, no C. jejuni strain and 14 strains of C. coli were isolated. All C. coli strains were resistant, and three C. jejuni strains from broilers chickens were characterized with intermediate resistance to erythromycin. The MIC of the strains ranged from ≤0.5mg/μL to ≥128mg/μL. All resistant strains had the A2075G mutation, and one strain with intermediate resistance had the A2075G mutation. However, the A2074C mutation and the erm(B) gene were not detected. High resistance levels were detected in C. coli strains isolated from swine. The MAMA-PCR is a practical tool for detecting the erythromycin resistance in Campylobacter strains.