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1.
Semina ciênc. agrar ; 43(5): 2093-2108, jun. 2022. tab, graf
Artigo em Inglês | VETINDEX | ID: biblio-1395635

Resumo

Antimicrobial resistance (AMR) is a growing concern in human and animal health. Public discussions on these issues have contributed to an increased demand for antibiotic-free food. Studies comparing the antimicrobial resistance profiles of bacteria in foodstuffs originating from farming systems with restrictions on the use of antimicrobials are scarce. This study aimed to assess the antimicrobial resistance profiles of generic Escherichia coli isolated from whole chickens originating from farming systems with and without restrictions on the use of antimicrobials. For this purpose, three groups of E. coli strains were formed: (GC) from chickens reared in conventional production systems, without restriction on the use of antimicrobials (n=72); (GL) from chickens reared in farming systems certified as free of any antibiotic use (n=72); and (GO) from chickens from an organic farming system (n=72). Whole chicken units were individually rinsed as recommended by ISO 17604:2015, and E. coli was isolated from the rinse suspension. To evaluate the resistance profile, E. coli strains were tested against 12 antimicrobials using broth microdilution or disk diffusion tests. Eighty strains (40.7%) were found to be fully susceptible to the tested antimicrobials, and 23.6% were multidrug resistant. The highest frequencies of resistance were observed to tetracycline (GC=37,5%; GL=34,7%; GO=25%) and trimethoprim (GC=27,8%; GL=34,7%; GO=22,2%). In the case of multidrug resistant strains, GC presented 32% (n=23) of strains with multidrug resistance characteristics whereas the GL and GO groups presented 22% (n=16) and 17% (n=12), respectively. As for the totally susceptible strains, a frequency of 56% of Tsus strains was observed in the organic group, whereas this frequency was 33% in the GC and GL groups. Using GC as a reference, the Poisson regression model showed a higher occurrence of fully susceptible E. coli strains, as well as lower frequencies of multidrug resistance and resistance to ampicillin and nalidixic acid in GO. The GL group exhibited the lowest frequency of ampicillin resistance. These observations suggest that the lower selection pressure for antimicrobial use in the farming system may be reflected in the resistance profile of bacteria present in foodstuffs purchased by consumers.(AU)


A resistência antimicrobiana (AMR) é uma preocupação crescente para a saúde humana e animal. A discussão pública dessas questões tem contribuído para o aumento da demanda por alimentos produzidos sem o uso de antibióticos. No entanto, estudos que comparem os perfis de resistência antimicrobiana de bactérias em alimentos oriundos de sistemas agrícolas com restrição ao uso de antimicrobianos ainda são escassos. O objetivo deste estudo foi avaliar o perfil de resistência antimicrobiana em Escherichia coli genérica isolada de carcaças de frangos inteiros oriundos de sistemas de criação com e sem restrições ao uso de antimicrobianos. Para tanto, três grupos de cepas de E. coli foram formados: (GC) isolados de carcaças de frangos criados no sistema convencional - sem restrição de uso de antimicrobianos (n=72); (GL) isolados de frangos de sistemas certificados sem uso de antimicrobianos (n=72); (GO) de frangos originados de produção orgânica (n=72). As unidades de frango inteiro foram submetidas à lavagem conforme recomendado pela ISO 17604: 2015 e E. coli foi isolada da suspensão de enxágue. Para avaliar o perfil de resistência, as cepas de E. coli foram testadas frente à 12 antimicrobianos pelos testes de microdiluição em caldo ou difusão em disco. Oitenta cepas (40,7%) foram totalmente suscetíveis aos antimicrobianos testados e 23,6% multirresistentes. As maiores frequências de resistência foram observadas frente a tetraciclina (GC=37,5%; GL=34,7%; GO=25%) e trimetoprima (GC=27,8%; GL=34,7%; GO=22,2%). No caso de cepas multirresistentes, GC apresentou 32% (n=23) das cepas com características de multirresistência enquanto os grupos GL e GO apresentaram 22% (n=16) e 17% (n=12), respectivamente. Quanto às cepas totalmente suscetíveis, foi observada uma frequência de 56% de cepas Tsus no grupo orgânico enquanto tal frequência foi de 33% nos grupos GC e GL. Utilizando GC como referência, o modelo de regressão de Poisson demonstrou maior ocorrência de cepas de E. coli totalmente suscetíveis, bem como menores frequências de multirresistência e resistência à ampicilina e ácido nalidíxico no GO. Em GL, apenas a frequência mais baixa de resistência à ampicilina pôde ser demonstrada. Essas observações sugerem que a menor pressão de seleção do uso de antimicrobianos no sistema de cultivo pode se refletir no perfil de resistência das bactérias presentes nos alimentos adquiridos pelo consumidor.(AU)


Assuntos
Animais , Galinhas/imunologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Carne/microbiologia , Escherichia coli/isolamento & purificação
2.
Acta sci. vet. (Impr.) ; 48: Pub.1743-Jan. 30, 2020. tab
Artigo em Inglês | VETINDEX | ID: biblio-1458266

Resumo

Background: The indiscriminate use of antibiotics in food-animal production has a major impact on public health, particularly in terms of contributing to the emergence and dissemination of antimicrobial resistant bacteria in the food-animal production chain. Although Pseudomonas species are recognized as important spoilage organisms in foodstuff, they are also known as opportunistic pathogens associated with hospital-acquired infections. Furthermore, Pseudomonas can play a role as potential reservoirs of antimicrobial resistance genes, which may be horizontally transferred to other bacteria. Considering that cephalosporins (3rd and higher generations) and carbapenems are critically important beta-lactam antimicrobials in human medicine, this study reports the occurrence and genomic characterization of a meropenem-nonsusceptible Pseudomonas otitidis strain recovered from a chicken carcass in Brazil. Materials, Methods & Results: During the years 2018-2019, 72 frozen chicken carcasses were purchased on the retail market from different regions in Brazil. Aliquots from individual carcass rinses were screened for Extended Spectrum Beta-lactamase (ESBL)-producing bacteria in MacConkey agar supplemented with 1mg.L-1 cefotaxime. Phenotypically resistant isolates were further tested for resistance to other antimicrobials and confirmed as ESBL-producers by means of disk-diffusion method using Müller-Hinton agar. Only one meropenen-nonsusceptible isolate was detected and submitted to whole genome sequencing (WGS) in Illumina Miseq. The strain was identified as Pseudomonas otitidis by local alignment of the 16S rRNA sequence using BLASTn and confirmed by Average Nucleotide Identity (ANI) analysis using JspeciesWS database. Genes encoding for antimicrobial resistance were detected by means...


Assuntos
Animais , Carbapenêmicos/agonistas , Carne/microbiologia , Farmacorresistência Bacteriana , Impressão Genômica/genética , Meropeném/antagonistas & inibidores , Pseudomonas/genética , Galinhas/microbiologia , Uso Excessivo de Medicamentos Prescritos
3.
Ci. Rural ; 50(12): e20200264, 2020. ilus
Artigo em Inglês | VETINDEX | ID: vti-29590

Resumo

This paper reports the abortion of a male Aberdeen Angus bovine by a vaccine strain of Bacillus anthracis, describing the pathological and microbiological findings and the genome sequence. Necropsy findings included multifocal areas of hemorrhage in different organs. Histologically, various organs showed hemorrhage, fibrin exudation, necrosis associated with countless bacillary bacterial clumps and severe neutrophilic inflammatory infiltrate. In the microbiological examination, numerous rough, nonhemolytic, gray and dry colonies with irregular edges were isolated from liver, lung and abomasum content samples. Gram staining revealed square-ended Gram-positive rods arranged in chains. B. anthracis identification was confirmed by detection of the molecular chromosomal marker Ba813. The genomes from the isolated B. anthracis (named SPV842_15) and from the isolated vaccinal strain (Brazilian vaccinal strain), which was recovered from a commercial vaccine used in the pregnant cow, were sequenced. Genomic comparisons displayed a high level of nucleotide identity in the comparisons between B. anthracis SPV842_15 and the B. anthracis Brazilian vaccinal strain (98,2%). Furthermore, in both strains, only the plasmid pX01 sequence was detected. Although, vaccination against anthrax is characterized by an elevated protective profile and very low residual virulence, immunization with Sterne strains can cause abortion in cattle, presumably by the plasmid pX01 toxins in rare or special situations.(AU)


Este trabalho relata um aborto de um bovino, macho, Aberdeen Angus, por uma cepa vacinal de Bacillus anthracis, descreve os achados patológicos, microbiológicos e o sequenciamento do genoma. Os achados de necropsia incluíram áreas multifocais de hemorragias em diferentes órgãos. Histologicamente, órgãos afetados apresentaram hemorragia, exsudação de fibrina, necrose associada a miríades bacterianas bacilares e intenso infiltrado inflamatório neutrofílico. No exame microbiológico, foram isoladas numerosas colônias rugosas, não hemolíticas, cinzas e secas, com bordas irregulares a partir de amostras de fígado, pulmão e conteúdo do abomaso. A coloração de Gram revelou bastonetes Gram-positivos dispostos em cadeias. A identificação do B. anthracis foi confirmada pela detecção do marcador cromossômico molecular Ba813. Os genomas do isolado B. anthracis (SPV842_15) e do isolado vacinal (cepa vacinal brasileira), recuperado de uma vacina comercial utilizada na vaca prenhe, foram sequenciados. Comparações genômicas mostraram um elevado nível de identidade de nucleotídeos entre B. anthracis SPV842_15 e cepa vacinal brasileira (98,2%). Além disso, em ambas as estirpes foi detectada apenas a sequência do plasmídeo pX01. Embora a vacinação contra o antraz seja caracterizada por um perfil protetor elevado e uma virulência residual muito baixa, a imunização com estirpes de Sterne pode causar aborto em bovinos, presumivelmente pelas toxinas do plasmídeo pX01 em situações raras ou específicas.(AU)


Assuntos
Animais , Bovinos , Doenças dos Bovinos , Bacillus anthracis , Aborto Animal , Antraz/veterinária
4.
Braz. J. Microbiol. ; 49(1): 18-19, jan.-mar. 2018.
Artigo em Inglês | VETINDEX | ID: vti-19069

Resumo

Bacillus anthracis strain SPV842_15 was isolated from bovine fetus, while B. anthracis strain Brazilian vaccinal was recovered from a commercial vaccine. We report here the genome sequences of both strains. The SPV842_15 genome is composed of a single circular chromosome with a length of 5,228,664 base pairs, and comprises 5911 coding sequences. In turn, the Brazilian vaccinal genome remains in 201 contigs with 5733 coding sequences. Both genomes have an overall C + G content of 35.4%, and 11 genes encoding the ribosomal RNAs (rRNAs) 5S, 16S and 23S. Only the plasmid pX01 sequence, which carries genes for toxins synthesis, was detected and completely assembled for both strains. These plasmids have a length of 181,684 base pairs and a C + G content of 32.5%. These genomic data generate insights about vaccinal B. anthracis virulence.(AU)


Assuntos
Bacillus anthracis/genética , Bacillus anthracis/patogenicidade , Genoma Bacteriano , Vacinas contra Antraz/análise
5.
Acta sci. vet. (Impr.) ; 41: Pub. 1099, 2013. tab
Artigo em Inglês | SES-SP, VETINDEX, SES SP - Instituto Pasteur, SES-SP | ID: biblio-1059362

Resumo

Background: Rabies has long been recognized as the major cause of encephalitis in cattle in Latin American countries. It has been estimated that nearly 50.000 cattle heads per year are lost due to encephalitis in that subcontinent, with a significant economic impact on cattle productive chains. In Brazil only, 2.500 to 3.000 cattle heads are estimated to be lost every year due to rabies. However, it is believed that rabies incidence in cattle is much larger, since usually only a few samples from affected animals in disease outbreaks are submitted to diagnostic laboratories. Rabies encephalitis is promptly and accurately diagnosed; however, particularly when rabies is excluded as causa mortis, the agent responsible for neurological disease of infectious origin often remains undetermined. Two bovine herpesviruses (BoHVs), bovine herpesvirus type 1 (BoHV-1) and bovine herpesvirus type 5 (BoHV-5) are major pathogens of cattle which are widely disseminated in Brazil. As usual in herpesvirus' biology, these tend to infect a large number of hosts and establish lifelong latent infections which may occasionally be reactivated. Both viruses, particularly BoHV-5, are often recovered from cases of neurological disease in cattle. The participation of BoHVs in the differential diagnosis of rabies must be evaluated. Besides, there might be associations between the occurrence of rabies and BoHV infections that deserve investigation. The aim of this study was to investigate whether bovine herpesvirus 1 and 5 would play a significant role in cases of neurological disease where rabies was the presumptive clinical diagnosis. In addition, associations between the occurrence of rabies and BoHV infections were searched for. The approach adopted for conducting such investigations was based on the search for viral nucleic acids as well as classical virus isolation on tissues of cattle submitted to rabies diagnosis over a two-year period, including rabies-positive and rabies-negative specimens. Materials, Methods & Results: Brain tissue samples of 101 cattle originally submitted to rabies diagnosis were collected over a two year period (2009-2010) from various municipalities within the state of Rio Grande do Sul, Brazil. Thirty nine of these samples had the diagnosis of rabies confirmed by standard laboratory diagnostic methods. Aliquots of tissues were submitted to DNA extraction and examined in search for genomes of bovine herpesviruses (BoHV) types 1 (BoHV-1) and 5 (BoHV-5) by as well as for infectious virus. Bovine herpesvirus genomes were detected in 78/101 (77.2%) samples, in which BoHV-1 genomes were detected in 26/78 (25.7%), BoHV-5 genomes in 22/78 (21.8%) and mixed BoHV infections (BoHV-1 and BoHV-5 genomes) were detected in 30/101 (29.7%) samples. In the 39 samples with confirmed rabies diagnosis, BoHV-1 DNA was detected in 9/39 (23%), BoHV-5 DNA in 6/39 (15.4%) and mixed infections with both BoHV types in 16/39 (41%) samples. However, no infectious herpesvirus was recovered from any of the specimens examined. Discussion: The high prevalence of BoHV1 and BoHV-5 infections was evidenced in the sampled population, but the absence of infectious BoHVs indicate that these were not associated to the occurrence of the cases of encephalitis where rabies was the primary suspicion. In addition, no association was detected between occurrence of rabies and detection of BoHVs, since the frequency of detection of herpesvirus genomes did not significantly differ between rabies-positive and rabies-negative samples. The detection of BoHV DNA in scattered areas of the brain with no infectious virus suggests that latency may take place in different regions of the brain.


Assuntos
Animais , Bovinos , Doenças dos Bovinos , Infecções por Herpesviridae/veterinária , Encefalite Viral/veterinária , Herpesvirus Bovino 1 , Raiva/diagnóstico , Reação em Cadeia da Polimerase
6.
Pesqui. vet. bras ; 30(7): 515-522, 2010. ilus, tab
Artigo em Inglês | VETINDEX | ID: vti-14247

Resumo

The serum neutralization (SN) test is the gold standard method to measure neutralizing antibodies to bovine herpesviruses. However, in view of the further subdivisions of bovine herpesviruses in types/subtypes, defining which virus to use at challenge in SN tests may be difficult. In view of that, this study was carried out to re-evaluate (SN) sensitivity with different types/subtypes of bovine herpesviruses types 1 (BoHV-1) and 5 (BoHV-5) as challenge viruses. Bovine sera (n=810) were collected from two distinct geographic regions and tested by SN with three type 1 viruses (BoHV-1.1 strains "Los Angeles" and "EVI123/98"; BoHV-1.2a strain "SV265/96") and three type 5 viruses (BoHV-5a strain "EVI88/95"; BoHV-5b strain "A663" and BoHV-5c "ISO97/95"). SN tests were performed with a 1 hour incubation of the serum-virus mixtures at 37ºC against 100 TCID50 of each of the viruses. SN sensitivity varied greatly depending on the challenge virus used in the test. The highest sensitivity (327 positive/810 total sera tested; 40.37 percent) was attained when the positive results to the six viruses were added together. No association could be found between any particular type or subtype of virus and the sensitivity of the test. When positive results to each single strain were considered, SN sensitivity varied from 41.7 percent to 81.7 percent, depending on the virus and the geographic region of origin of the sera. Variation was detected even when challenge viruses belonged to the same subtype, where disagreement between positive results reached 41 percent. These results indicate that one hour incubation SN tests against single viruses, as performed here, may display a significantly low sensitivity (p=0.05); performing SN tests against a number of different viruses may increase considerably SN sensitivity. Furthermore, the choice of virus used for challenge is critical in SN tests. In addition, sera from different geographic regions may give rise to disagreeing results with different strains of BoHV-1 and BoHV-5. This might be particularly relevant for control programs and in international trade, were maximum sensitivity should be targeted.(AU)


O teste de soroneutralização (SN) é o método padrão para a mensuração de anticorpos neutralizantes para herpesvírus bovinos. Entretanto, com as subdivisões propostas destes agentes em tipos e subtipos, a definição de qual amostra utilizar como virus de desafio à SN pode ser difícil. Em vista disso, este estudo foi realizado para re-avaliar a sensibilidade de testes de SN utilizando diferentes tipos e subtipos de herpesvírus bovinos tipos 1 (BoHV-1) e 5 (BoHV-5) como amostras de desafio. Soros bovinos (n=810) foram coletados de duas regiões geográficas distintas e testados frente a amostras do tipo 1 (BoHV-1.1: amostras "Los Angeles" e "EVI123/98", BoHV-1.2a: amostra "SV265/96") e três amostras do tipo 5 (BoHV-5a: "EVI88/95"; BoHV-5b: "A663" e BoHV-5c "ISO97/95"). Os testes de SN foram realizados com incubação de 1 hora a 37ºC da mistura soro-vírus, frente a 100 doses infectantes para 50 por cento dos cultivos celulares (DICC50) de cada um dos vírus. A sensibilidade da SN variou grandemente em função do vírus utilizado no teste. A maior sensibilidade (327 soros positivos/810 soros testados; 40.37 por cento) foi alcançada quando os resultados positivos frente aos seis diferentes vírus foram somados. Nenhuma associação foi detectada entre determinado tipo/subtipo de vírus e a sensibilidade do teste. Quando resultados positivos frente a cada vírus foram considerados isoladamente, a sensibilidade da SN variou entre 41,7 por cento a 81,7 por cento, dependendo do vírus de desafio e da região geográfica de origem das amostras de soro. Variação foi detectada mesmo quando as amostras de desafio pertenciam a um mesmo subtipo; a discrepância entre os resultados positivos atingiu até 41 por cento. Estes resultados indicam que testes de SN contra amostras isoladas de vírus podem apresentar uma sensibilidade notadamente baixa; o emprego de diferentes amostras de vírus de desafio pode aumentar consideravelmente a sensibilidade da prova. Além disso, a escolha da amostra de vírus para a realização do teste é crítica. Outro achado importante é que sorors de diferentes regiões geográficas podem dar resultados discordantes frente a diferentes amostras de BoHV-1 e BoHV-5. Estes achados são particularmente relevantes para programas de controle destas infecções e para o comércio internacional, onde a sensibilidade deve ser maximizada.(AU)


Assuntos
Animais , Bovinos , Testes de Neutralização/instrumentação , Herpesvirus Bovino 1 , Herpesvirus Bovino 5 , Controle de Doenças Transmissíveis
7.
Tese em Português | VETTESES | ID: vtt-1999

Resumo

Com os avanços recentes nos métodos de detecção de patógenos, a importância das doenças polimicrobianas tornou-se mais evidente e a identificação de interações de patógenos e seus mecanismos de potenciação de enfermidades se tornou um tema de grande interesse. O circovírus suíno tipo 2 (PCV2) está associado a várias síndromes, tais como a síndrome multissistêmica do definhamento dos suínos (SMDS), a síndrome da dermatite e nefropatia dos suínos (SDNS), o complexo das doenças respiratórias dos suínos (CDRS), falhas reprodutivas e tremores congênitos, coletivamente chamadas ¿doenças associadas ao circovírus suíno tipo 2¿ (PCVAD), e que, além do PCV2, podem apresentar diferentes graus de envolvimento de outros agentes. Dentre estas, a SMDS é a que apresenta maior impacto na cadeia produtiva de suínos. Sendo a SMDS uma doença multifatorial e polimicrobiana, estudos buscando identificar associações do PCV2 com outros patógenos são importantes. No presente trabalho foram desenvolvidos ensaios moleculares para a detecção de alguns agentes cuja potencial participação nas PCVAD não havia ainda sido estudada com maior profundidade. Dessa forma, o citomegalovírus suíno (PCMV) e os recém-identificados bocavírus suínos do tipo 1, 2, 3 e 4 (PBoV1-4) foram pesquisados em amostras de animais afetados ou não pela SMDS, em diferentes faixas etárias. O PCMV foi detectado em altas taxas em ambos os grupos de animais, afetados ou não pela SMDS, sendo que nenhum tipo de associação com a SMDS pode ser inferida quanto à detecção de genomas de PCMV e o desenvolvimento da síndrome. A detecção de genomas de PBoV2 e 3 foi associada com animais afetados pela SMDS, enquanto nenhum tipo de associação foi inferida com a detecção de genomas de PBoV1 e do PBoV4. Animais afetados pela síndrome apresentam frequência de detecção e carga viral de PBoV2 significantemente superior à frequência encontrada em animais saudáveis com idade equivalente, revelando uma associação positiva entre PBoV2 e a SMDS. Por outro lado, animais adultos possuem uma carga viral significativamente superior a dos animais jovens sem sinais clínicos de SMDS. Os resultados obtidos possibilitaram detectar, pela primeira vez, os quatro tipos PBoV em amostras de suínos no Brasil. Paralelamente, esse estudo mostrou, pela primeira vez, a presença de genomas circulantes de PBoV1, PBoV2 e PBoV4 em animais adultos clinicamente saudáveis. Além disso, permitiu sugerir uma possível associação entre SMDS e PBoV2 e PBoV3, mostrando que mais estudos devem ser realizados para elucidar tal associação


With recent advances in pathogen detection methods, the importance of polymicrobial diseases has become more evident, and identification of pathogen interactions and their disease potentiation mechanisms has become a topic of great interest. The porcine circovirus type 2 (PCV2) is associated with several syndromes, such as Postweaning multisystemic wasting syndrome (PMWS), Porcine dermatitis and nephropathy syndrome (PDNS), Porcine respiratory disease complex (PRDC), reproductive failures and congenital tremors, collectively called "Porcine circovirus type 2 associated diseases" (PCVAD), that beyond PCV2, may have different degrees of involvement of other agents. Among these, PMWS have the main impact on pig production chain. As PMWS is a multifactorial and polymicrobial disease, studies attempting to identify associations of PCV2 with other pathogens are important. In the present work, we developed molecular assays for detection of some agents whose potential role in PCVAD had not yet been studied in greater depth. Thus, porcine cytomegalovirus (PCMV) and newly identified porcine bocavirus type 1, 2, 3 and 4 (PBoV1-4) were investigated in samples of animals with or without PMWS, in different age groups. PCMV was detected at high rates in both groups of animals, and any type of association with PMWS could be inferred regarding detection of PCMV genomes and syndrome development. The PBoV2 and PBoV3 genomes detection was associated with animals affected by PMWS, while no association could be inferred from detection of genomes PBoV1 and PBoV4. Animals affected by the syndrome had significantly higher PBoV2 frequency of detection and viral load than the healthy animals with equivalent age, showing a positive association between PBoV2 and PMWS. Moreover, adult animals had significantly higher viral load than young animals without clinical signs of PMWS. Obtained results showed, for the first time, the four types of PBoV in Brazilian pig samples and the presence of circulating genomes of PBoV1, PBoV2 and PBoV4 in clinically healthy adult animals. It also allowed suggesting a possible association between PBoV2 and PBoV3 with PMWS, showing that more studies are needed to elucidate this association

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