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Dive into the research topics where Maria Gabriela Xavier de Oliveira is active.

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Featured researches published by Maria Gabriela Xavier de Oliveira.


The Scientific World Journal | 2014

Virulence Profiles, Phylogenetic Background, and Antibiotic Resistance of Escherichia coli Isolated from Turkeys with Airsacculitis

Marcos Paulo Vieira Cunha; Maria Gabriela Xavier de Oliveira; Mirela Caroline Vilela de Oliveira; Ketrin C. Silva; Cleise Ribeiro Gomes; Andrea Micke Moreno; Terezinha Knöbl

Avian Pathogenic Escherichia coli (APEC) has been studied for decades because of its economic impact on the poultry industry. Recently, the zoonotic potential of APEC and multidrug-resistant strains have emerged. The aim of this study was to characterize 225 APEC isolated from turkeys presenting airsacculitis. The results showed that 92% of strains presented a multidrug-resistance (MDR), and the highest levels of resistance were to sulfamethazine (94%) and tetracycline (83%). Half of these strains were classified in phylogenetic group B2, followed by B1 (28.6%), A (17.1%), and D (4.8%). The prevalence of virulence genes was as follows: salmochelin (iroN, 95%), increased serum survival (iss, 93%), colicin V (cvi/cva, 67%), aerobactin (iucD, 67%), temperature-sensitive haemagglutinin (tsh, 56%), iron-repressible protein (irp2, 51%), invasion brain endothelium (ibeA, 31%), vacuolating autotransporter toxin (vat, 24%), K1 antigen (neuS, 19%), enteroaggregative heat-stable cytotoxin (astA, 17%), and pilus associated with pyelonephritis (papC, 15%). These results demonstrate that the majority of the investigated strains belonged to group B2 and were MDR. These data suggest that turkeys may serve as a reservoir of pathogenic and multidrug-resistance strains, reinforcing the idea that poultry plays a role in the epidemiological chain of ExPEC.


Diagnostic Microbiology and Infectious Disease | 2017

High-virulence CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from commercial turkeys

Ketrin C. Silva; Marcos Paulo Vieira Cunha; Louise Cerdeira; Maria Gabriela Xavier de Oliveira; Mirela Caroline Vilela de Oliveira; Cleise Ribeiro Gomes; Nilton Lincopan; Terezinha Knöbl; Andrea Micke Moreno

This study reports the high-virulence phylogenetic backgrounds of CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from turkeys sent to slaughter and condemned by airsacculitis in Brazil. Among 300 air sac samples, seven E. coli strains produced plasmid-mediated CMY-2-type AmpC, of which three carried also the blaCTX-M-2 Extended Spectrum Beta-Lactamase encoding gene. Interestingly, the transfer of the blaCMY-2 gene was positive for three E. coli strains, being associated with the presence of IncI1 plasmids. The complete sequence of the representative pJB10 plasmid revealed that the blaCMY-2 gene was within a transposon-like element in the classical genetic environment consisting of tnpA-blaCMY-2-blc-sugE structure. This plasmid with 94-kb belonged to the sequence type (ST) 12 among IncI1 plasmids, which has been associated with the worldwide spread of blaCMY-2 among Salmonella enterica and E. coli. Furthermore, to the best of our knowledge, this is the first complete sequence of a CMY-2-encoding plasmid derived from an Escherichia coli isolated from food-producing animals in Latin America.


Brazilian Journal of Microbiology | 2017

Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC)

Lilian Aparecida Sanches; Marcelo da Silva Gomes; Rodrigo Hidalgo Friciello Teixeira; Marcos Paulo Vieira Cunha; Maria Gabriela Xavier de Oliveira; Mônica A. M. Vieira; Tânia A. T. Gomes; Terezinha Knöbl

Psittacine birds have been identified as reservoirs of diarrheagenic Escherichia coli, a subset of pathogens associated with mortality of children in tropical countries. The role of other orders of birds as source of infection is unclear. The aim of this study was to perform the molecular diagnosis of infection with diarrheagenic E. coli in 10 different orders of captive wild birds in the state of São Paulo, Brazil. Fecal samples were analyzed from 516 birds belonging to 10 orders: Accipitriformes, Anseriformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Pelecaniformes, Piciformes, Psittaciformes and Strigiformes. After isolation, 401 E. coli strains were subjected to multiplex PCR system with amplification of genes eae and bfp (EPEC), stx1 and stx2 for STEC. The results of these tests revealed 23/401 (5.74%) positive strains for eae gene, 16/401 positive strains for the bfp gene (3.99%) and 3/401 positive for stx2 gene (0.75%) distributed among the orders of Psittaciformes, Strigiformes and Columbiformes. None of strains were positive for stx1 gene. These data reveal the infection by STEC, typical and atypical EPEC in captive birds. The frequency of these pathotypes is low and restricted to few orders, but the data suggest the potential public health risk that these birds represent as reservoirs of diarrheagenic E. coli.


Avian Pathology | 2016

Virulence and antimicrobial resistance of Klebsiella pneumoniae isolated from passerine and psittacine birds

Marcos Paulo Vieira Cunha; Maria Gabriela Xavier de Oliveira; M. C. V. Oliveira; N. Philadelpho; D.C. Romero; L. Milanelo; Marta Brito Guimarães; Antonio J. Piantino Ferreira; Andrea Micke Moreno; L. R. M. Sá; Terezinha Knöbl

ABSTRACT Klebsiella pneumoniae is considered one of the most important Gram-negative opportunistic pathogens. The contact between humans and birds poses health risks to both. The aim of this study was to investigate the resistance and virulence of K. pneumoniae isolates from psittacines and passerines, seized from illegal trade in Brazil. We analysed 32 strains isolated from birds of the orders Psittaciformes and Passeriformes by polymerase chain reaction (PCR) for virulence factor genes. Antibiotic resistance was assessed by disk diffusion assay and PCR. The results indicated that fimH (100%), uge (96.8%), kfu (81.2%) and irp-2 (68.7%) were the most common virulence genes, followed by kpn (46.8%), K2 (43.7%), mrkD (34.3%) and iroN (15.6%). The combination of virulence genes resulted in a great diversity of genotypes and the heterogeneity of the strains is also confirmed in the analysis by amplified fragment length polymorphism. The susceptibility profiles of the K. pneumoniae showed 25% of multiple antibiotic resistance strains. We identified seven strains that presented non-extended spectrum beta lactamase blaSHV variants SHV-1 and SHV-11 and one strain positive to the blaTEM-1 gene. Plasmid-mediated quinolone resistance was present in 10 strains (10/32). The data obtained in this study reveal the pathogenic potential of this pathogen and highlight the need for surveillance and monitoring.


Genome Announcements | 2015

Draft Genome Sequence of Bordetella avium Nh1210, an Outbreak Strain of Lockjaw Syndrome.

Luisa Zanolli Moreno; Terezinha Knöbl; André Grespan; Maria Roberta Felizardo; Cleise Ribeiro Gomes; Thais Sebastiana Porfida Ferreira; Maria Gabriela Xavier de Oliveira; Livia Myriantheus; Andrea Micke Moreno

ABSTRACT Bordetella avium is a highly contagious bacterium that infects the upper respiratory tract of birds. B. avium Nh1210 is an outbreak strain of lockjaw syndrome in juvenile cockatiel chicks (Nymphicus hollandicus). Here, we report the draft genome sequence of strain Nh1210.


Tropical Animal Health and Production | 2017

Arcobacter spp. in fecal samples from Brazilian farmed caimans (Caiman yacare, Daudin 1802)

Maria Gabriela Xavier de Oliveira; Leandro Nogueira Pressinotti; Giovane Spínola de Carvalho; Mirela Caroline Vilela de Oliveira; Luisa Zanolli Moreno; Carlos E.C. Matajira; Alessandro Spínola Bergamo; Victor Manuel Aleixo; Alexandre Caixeta Veiga; Elvis de Souza Corsino; Ana Paula G. Christ; Maria Inês Zanolli Sato; Andrea Micke Moreno; Terezinha Knöbl

The aim of this study was to perform the identification and molecular characterization of Arcobacter cryaerophilus and Arcobacter butzleri isolated from caiman (Caiman yacare), kept at a production farm, in Brazil. Forty fecal samples were analyzed. After isolation and identification, 21/40 strains of A. butzleri and 19/40 strains of A. cryaerophilus were subjected to PCR for potential virulence gene detection. The results of the PCR showed 38/40 strains positive for the cadF, cj1349, ciaB, and tlyA genes, 39/40 strains positive for the pldA gene, and 40/40 strains positive for the mviN gene. None of the strains presented the irgA gene. Hemagglutinin (hecA gene) and hemolysin (hecB) genes were detected in 21/40 and 16/40 strains, respectively. The SE-AFLP showed a great genetic diversity, but some clonally groups were disseminated in various tanks. These data reveal that the strains presented the same virulence traits described from Arcobacter isolated from food-borne disease in humans.


Arquivo Brasileiro De Medicina Veterinaria E Zootecnia | 2017

Utilização do yacon ( Smallanthus sonchifolius ) na proteção contra colonização intestinal de frangos de corte infectados por Salmonella Enteritidis

Maria Gabriela Xavier de Oliveira; M.C. Porretta; N.M. Itaya; Mirela Caroline Vilela de Oliveira; J.N. Reple; M.P.V. Cunha; L.A. Sanches; Y.M. Davies; M.C. Menão; J.C.S. Borges; L.E.M. Polaquini; Terezinha Knöbl

ABSTRACT The fructan inulin-type oligosaccharides favor the multiplication of some bacterial genera in the intestine, promoting a prebiotic effect. This study evaluated the effect of inulin extracted from yacon roots (Smallanthus sonchifolius) on intestinal colonization of broilers experimentally infected with Salmonella Enteritidis. Sixty-one day old chicks were grouped into three treatments, with two replicates, and reared until 21 days. Birds in the yacon group received 100mg of inulin/day orally for three consecutive days. On the seventh day of life the treated birds and the positive control were challenged orally with a culture of S . Enteritidis . There were no differences between groups in live performance. The infectivity index of the chicks supplemented with yacon was lower until the sixth day after the challenge, but at the end of the experiment it was higher than the positive control. Data from this study show that the use of inulin during the first 3 days of life caused a reduction of intestinal colonization of chickens by


Journal of Medical Primatology | 2016

Suppurative peritonitis by Klebsiella pneumoniae in captive gold‐handed tamarin (Saguinus midas midas)

Maria Flávia Lopes Guerra; Rodrigo Hidalgo Fricielle Teixeira; Vanessa Lanes Ribeiro; Marcos P. V. Cunha; Maria Gabriela Xavier de Oliveira; Ketrin C. Silva; Ana Silva; Nilton Lincopan; Andrea Micke Moreno; Terezinha Knöbl

This report describes an outbreak of suppurative peritonitis caused by Klebsiella pneumoniae in an adult female of captive golden‐handed tamarin (Saguinus midas midas). Two virulent and multidrug‐resistant strains were isolated and classified through MLST as ST60 and ST1263. The microbiological diagnosis works as a support tool for preventive measures.


Brazilian Journal of Veterinary Research and Animal Science | 2016

Pesquisa de bactérias gram-negativas em canários-da-terra (Sicalis flaveola) resgatados do tráfico ilegal de aves no Brasil

Marta Brito Guimarães; Liliane Milanelo; Maria Gabriela Xavier de Oliveira; Vasco T.M. Gomes; Natalia Philadelpho Azevedo; Marcos Paulo Vieira Cunha; Luisa Zanolli Moreno; Débora Cristina Romero; Ana Paula G. Christ; Maria Inês Zanoli Sato; Andrea Micke Moreno; Antonio J. Piantino Ferreira; L. R. M. Sá; Terezinha Knöbl

Passerines such as canaries or finches are the most unlawfully captured species that are sent to wildlife centers in São Paulo, Brazil. Captured birds may have infection by opportunistic bacteria in stressful situations. This fact becomes relevant when seized passerine are reintroduced. The aim of this study was to evaluate the health state of finches from illegal wildlife trade using microbiological approaches. Microbiological samples were collected by cloacal and tracheal swabs of 100 birds, captured during 2012 and 2013. The results indicate high frequency of gram-negative bacteria in feces and oropharynx, especially from the Enterobacteriaceae family (97.5%). The most frequent genera were Escherichia coli (46.5%) and Klebsiella pneumoniae (10.4%). Enterobacter cloacae, Serratia liquefaciens, Serratia spp. Klebsiella oxytoca and Citrobacter freundii were isolated with lower frequency from asymptomatic birds. The presence of enteropathogenic Escherichia coli (EPEC) and Shiga toxinproducing strain (STEC) confirm the zoonotic risks and public health concern.


XII Latin American Congress on Food Microbiology and Hygiene | 2014

Detecção de Cepas Virulentas de Arcobacter Butzleri em Carnes de Frangos e Suínos Provenientes de Açougues no Município de São Paulo

Maria Gabriela Xavier de Oliveira; Andrea Micke Moreno; Maria Garcia Spindola; Vasco T.M. Gomes; Pedro Henrique Nogueira de Lima Filsner; Thais Sebastiana Porfida Ferreira; Terezinha Knöbl

Maria Gabriela Xavier de Oliveira, Andrea Micke Moreno, Maria Garcia Spindola, Vasco Tulio de Moura Gomes, Pedro Henrique de Lima Filsner, Thais Sebastiana Porfida Ferreira, Terezinha Knobl. Deteccao de Cepas Virulentas de Arcobacter Butzleri em Carnes de Frangos e Suinos Provenientes de Acougues no Municipio de Sao Paulo. In: Anais do 12o Congresso Latinoamericano de Microbiologia e Higiene de Alimentos MICROAL 2014 [= Blucher Food Science Proceedings, num.1, vol.1]. Sao Paulo: Editora Blucher, 2014. DOI 10.5151/foodsci-microal-172 Deteccao de Cepas Virulentas de Arcobacter Butzleri em Carnes de Frangos e Suinos Provenientes de Acougues no Municipio de Sao Paulo

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