Genome-wide association mapping for heading date in oats under subtropical environments

Selection for heading date has been a decisive factor to increase areas cropped with oats in Brazil. Although important to oat breeders, genomic regions controlling heading date have not been completely identified. The objective of this study was to identify genomic regions controlling oat heading date in subtropical environments. A set of 412 oat genotypes, developed from 1974 to 2015, was assessed for heading date in contrasting environments and genotyped using genotyping-by-sequencing (GBS). Phenotypic and genotypic data were used in single and multi-environment association models. Quantitative trait loci (QTL) associated to heading date were identified on oat consensus groups Mrg02, Mrg05, Mrg06, Mrg12, and Mrg21. Some of the findings confirmed the association of genomic regions with heading date, while others emerge as new candidate regions associated to the trait. The genomic regions identified on Mrg02 and Mrg12 were associated to Vernalization 3 (Vrn3), while the genomic region identified on Mrg21 is associated with Vernalization 1 (Vrn1). The Vrn1 region was detected in Londrina, an environment with reduced vernalization condition, and in the multi-environment model. The results reveal that some genotypes of the panel are responsive to vernalization, increasing the days to heading without this environmental stimulus. Our results provide important contribution for a better understanding of heading date in subtropical environments and a strong basis for marker-assisted selection in oats.

Genetic diversity and heterotic grouping of sorghum lines using SNP markers

Sorghum breeding programs are based predominantly on developing homozygous lines to produce single cross hybrids, frequently with relatively narrow genetic bases. The adoption of complementary strategies, such as genetic diversity study, enables a broader vision of the genetic structure of the breeding germplasm. The purpose of this study was to evaluate the genetic diversity of sorghum breeding lines using structure analysis, principal components (PC) and clustering analyses. A total of 160 sorghum lines were genotyped with 29,649 SNP markers generated by genotyping-by-sequencing (GBS). The PC and clustering analyses consistently divided the R (restorer) and B (maintainer) lines based on their pedigree, generating four groups. Thirty-two B and 21 R lines were used to generate 121 single-cross hybrids, whose performances were compared based on the diversity clustering of each parental line. The genetic divergence of B and R lines indicated a potential for increasing heterotic response in the development of hybrids. The genetic distance was correlated to heterosis, allowing for the use of markers to create heterotic groups in sorghum.(AU)

Genetic diversity and heterotic grouping of sorghum lines using SNP markers

Sorghum breeding programs are based predominantly on developing homozygous lines to produce single cross hybrids, frequently with relatively narrow genetic bases. The adoption of complementary strategies, such as genetic diversity study, enables a broader vision of the genetic structure of the breeding germplasm. The purpose of this study was to evaluate the genetic diversity of sorghum breeding lines using structure analysis, principal components (PC) and clustering analyses. A total of 160 sorghum lines were genotyped with 29,649 SNP markers generated by genotyping-by-sequencing (GBS). The PC and clustering analyses consistently divided the R (restorer) and B (maintainer) lines based on their pedigree, generating four groups. Thirty-two B and 21 R lines were used to generate 121 single-cross hybrids, whose performances were compared based on the diversity clustering of each parental line. The genetic divergence of B and R lines indicated a potential for increasing heterotic response in the development of hybrids. The genetic distance was correlated to heterosis, allowing for the use of markers to create heterotic groups in sorghum.

Association mapping of drought tolerance indices in wheat: QTL-rich regions on chromosome 4A

Drought is likely the main abiotic stress that affects wheat yield. The identification of drought-tolerant genotypes represents an effective way of dealing with the continuous decrease in water resources as well as the increase in world population. The aim of this study was to identify single nucleotide polymorphisms (SNP) associated with drought tolerance indices in wheat by using a genome-wide association study (GWAS) under fully irrigated and rain-fed conditions. The drought tolerance indices (i.e., Stress Susceptibility Index, Stress Tolerance Index, Tolerance Index and Yield Stability Index) were calculated based on grain yield, 1,000-kernel weight and kernels per spike. The association panel was genotyped using genotyping-by-sequencing (GBS). A total of 175 SNPs exhibited statistical evidence of association with at least one drought tolerance index, explaining up to 6 % of the phenotypic variation. Forty-five SNPs were associated with more than one tolerance index (up to 4 agronomic traits). Most associations were located on chromosome 4A, supporting the hypothesis that this chromosome has a key role in drought tolerance which should be exploited for wheat improvement. In addition, statistical analysis detected SNPs associated with tolerance indices in both growing seasons, providing information about genetic regions with stable effects under different environmental conditions. This GWAS experiment serves as one of the few studies on association mapping for drought tolerance indices in wheat, which could increase the efficiency of rain-fed and irrigated crop production.

Association mapping of drought tolerance indices in wheat: QTL-rich regions on chromosome 4A

Drought is likely the main abiotic stress that affects wheat yield. The identification of drought-tolerant genotypes represents an effective way of dealing with the continuous decrease in water resources as well as the increase in world population. The aim of this study was to identify single nucleotide polymorphisms (SNP) associated with drought tolerance indices in wheat by using a genome-wide association study (GWAS) under fully irrigated and rain-fed conditions. The drought tolerance indices (i.e., Stress Susceptibility Index, Stress Tolerance Index, Tolerance Index and Yield Stability Index) were calculated based on grain yield, 1,000-kernel weight and kernels per spike. The association panel was genotyped using genotyping-by-sequencing (GBS). A total of 175 SNPs exhibited statistical evidence of association with at least one drought tolerance index, explaining up to 6 % of the phenotypic variation. Forty-five SNPs were associated with more than one tolerance index (up to 4 agronomic traits). Most associations were located on chromosome 4A, supporting the hypothesis that this chromosome has a key role in drought tolerance which should be exploited for wheat improvement. In addition, statistical analysis detected SNPs associated with tolerance indices in both growing seasons, providing information about genetic regions with stable effects under different environmental conditions. This GWAS experiment serves as one of the few studies on association mapping for drought tolerance indices in wheat, which could increase the efficiency of rain-fed and irrigated crop production.(AU)

Phenotypic and molecular characterization of erythromycin resistance in Campylobacter jejuni and Campylobacter coli strains isolated from swine and broiler chickens / Caracterização fenotípica e molecular da resistência à eritromicina em cepas de Campylobacter jejuni e Campylobacter coli isoladas de suínos e frangos de corte

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.(AU)

Campylobacter spp. é um agente bacteriano causador de gastroenterite em humanos e associado à síndrome de Guillain-Barré, sendo a campilobacteriose considerada uma das principais enfermidades de origem alimentar. Aves e suínos são importantes reservatórios desses microrganismos e seus produtos derivados crus ou mal cozidos são muitas vezes incriminados como fonte de infecção humana. A primeira escolha para o tratamento em casos humanos são os antimicrobianos da classe dos macrolídeos como à eritromicina. Dentro desse contexto, o objetivo deste estudo foi isolar Campylobacter jejuni e C. coli a partir de 20 amostras de conteúdo intestinal de frangos de corte e de 30 de suínos ao abate e investigar a resistência à eritromicina das estirpes obtidas e os possíveis mecanismos moleculares envolvidos nesta resistência. A concentração inibitória mínima foi determinada pela diluição em ágar e a técnica MAMA-PCR foi utilizada para detecção de mutações nas posições 2074 e 2075 da região 23s rRNA, foi pesquisado também a presença do gene erm(B) pela PCR. A partir do conteúdo intestinal de frangos de corte foram isoladas 18 estirpes de C. jejuni e duas de C. coli, enquanto de suínos foram obtidas 14 estirpes de C. coli e nenhuma estirpe de C. jejuni. Todas as estirpes de C. coli de suínos foram identificadas como resistentes e três estirpes de C. jejuni de frangos foram caracterizadas com resistência intermediária. A CIM das estirpes variou de ≤0,5mg/μL a ≥128mg/μL. Todas as estirpes resistentes tinham a mutação A2075G e uma cepa com resistência intermediária também apresentou a mutação A2075G. Não foi detectada a mutação A2074C ou a presença do gene erm(B) em nenhuma das estirpes obtidas. Os resultados revelam um alto nível de resistência em estirpes de C. coli isoladas de suínos frente a eritromicina. A técnica MAMA PCR utilizada se constitui em uma ferramenta prática para detecção da resistência à eritromicina em estirpes de C. jejuni e C. coli.(AU)

Phenotypic and molecular characterization of erythromycin resistance in Campylobacter jejuni and Campylobacter coli strains isolated from swine and broiler chickens / Caracterização fenotípica e molecular da resistência à eritromicina em cepas de Campylobacter jejuni e Campylobacter coli isoladas de suínos e frangos de corte

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.(AU)

Campylobacter spp. é um agente bacteriano causador de gastroenterite em humanos e associado à síndrome de Guillain-Barré, sendo a campilobacteriose considerada uma das principais enfermidades de origem alimentar. Aves e suínos são importantes reservatórios desses microrganismos e seus produtos derivados crus ou mal cozidos são muitas vezes incriminados como fonte de infecção humana. A primeira escolha para o tratamento em casos humanos são os antimicrobianos da classe dos macrolídeos como à eritromicina. Dentro desse contexto, o objetivo deste estudo foi isolar Campylobacter jejuni e C. coli a partir de 20 amostras de conteúdo intestinal de frangos de corte e de 30 de suínos ao abate e investigar a resistência à eritromicina das estirpes obtidas e os possíveis mecanismos moleculares envolvidos nesta resistência. A concentração inibitória mínima foi determinada pela diluição em ágar e a técnica MAMA-PCR foi utilizada para detecção de mutações nas posições 2074 e 2075 da região 23s rRNA, foi pesquisado também a presença do gene erm(B) pela PCR. A partir do conteúdo intestinal de frangos de corte foram isoladas 18 estirpes de C. jejuni e duas de C. coli, enquanto de suínos foram obtidas 14 estirpes de C. coli e nenhuma estirpe de C. jejuni. Todas as estirpes de C. coli de suínos foram identificadas como resistentes e três estirpes de C. jejuni de frangos foram caracterizadas com resistência intermediária. A CIM das estirpes variou de ≤0,5mg/μL a ≥128mg/μL. Todas as estirpes resistentes tinham a mutação A2075G e uma cepa com resistência intermediária também apresentou a mutação A2075G. Não foi detectada a mutação A2074C ou a presença do gene erm(B) em nenhuma das estirpes obtidas. Os resultados revelam um alto nível de resistência em estirpes de C. coli isoladas de suínos frente a eritromicina. A técnica MAMA PCR utilizada se constitui em uma ferramenta prática para detecção da resistência à eritromicina em estirpes de C. jejuni e C. coli.(AU)

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds / Suscetibilidade in vitro a antimicrobianos e determinantes genéticos de resistência em Streptococcus agalactiae isolados de mastite em rebanhos bovinos brasileiros

Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%), tetO in 23 (19.5%), and tetM in 24 (20.3%). The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%), tetracycline (35.6%), gentamicin (9.3%), clindamycin (20.3%), penicillin (3.4%), and amikacin (38.1%); conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health.

Streptococcus agalactiae é um dos principais agentes causadores de mastite em bovinos e de consequentes perdas econômicas aos produtores. Poucos estudos que avaliaram a susceptibilidade a antimicrobianos e a presença de determinantes genéticos de resistência para este agente em bovinos leiteiros do Brasil. Este trabalho teve por objetivo avaliar a frequência dos genes de resistência a antimicrobianos ermA, ermB, mefA, tetO, tetM, aphA3, aad-6, bem como a susceptibilidade in vitro aos antimicrobianos amicacina, eritromicina, clindamicina, tetraciclina, gentamicina, penicilina, ceftiofur e cefalotina, e as associações entre genótipos e fenótipos de resistência em 118 isolados de S. agalactiae provenientes de casos de mastite em rebanhos bovinos brasileiros. Dentre os genes de resistência pesquisados, ermB foi encontrado em 19 isolados (16,1%), tetO em 23 (19,5%) e tetM em 24 (20,3%). Os genes ermA, mefA, apha3 e aad6 não foram detectados. Verificou-se associação entre a presença dos genes ermB, tetM e tetO e os fenótipos de resistência à eritromicina, clindamicina e tetraciclina. Foram encontrados diferentes índices de resistência aos antibióticos testados: Eritromicina (19,5%), tetraciclina (35,6%), gentamicina (9,3%), clindamicina (20,3%), penicilina (3,4%) e amicacina (38,1%). Todos os isolados foram susceptíveis ceftiofur e cefalotina. Os testes de resistência aos antimicrobianos auxiliam na tomadade decisões relacionadas aos tratamentos, permitindo a escolha mais criteriosa dos antimicrobianos e oacompanhamento espaço-temporal da dinâmica de resistência para este patógeno tão relevante na saúdehumana e animal.

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds / Suscetibilidade in vitro a antimicrobianos e determinantes genéticos de resistência em Streptococcus agalactiae isolados de mastite em rebanhos bovinos brasileiros

Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%), tetO in 23 (19.5%), and tetM in 24 (20.3%). The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%), tetracycline (35.6%), gentamicin (9.3%), clindamycin (20.3%), penicillin (3.4%), and amikacin (38.1%); conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health.(AU)

Streptococcus agalactiae é um dos principais agentes causadores de mastite em bovinos e de consequentes perdas econômicas aos produtores. Poucos estudos que avaliaram a susceptibilidade a antimicrobianos e a presença de determinantes genéticos de resistência para este agente em bovinos leiteiros do Brasil. Este trabalho teve por objetivo avaliar a frequência dos genes de resistência a antimicrobianos ermA, ermB, mefA, tetO, tetM, aphA3, aad-6, bem como a susceptibilidade in vitro aos antimicrobianos amicacina, eritromicina, clindamicina, tetraciclina, gentamicina, penicilina, ceftiofur e cefalotina, e as associações entre genótipos e fenótipos de resistência em 118 isolados de S. agalactiae provenientes de casos de mastite em rebanhos bovinos brasileiros. Dentre os genes de resistência pesquisados, ermB foi encontrado em 19 isolados (16,1%), tetO em 23 (19,5%) e tetM em 24 (20,3%). Os genes ermA, mefA, apha3 e aad6 não foram detectados. Verificou-se associação entre a presença dos genes ermB, tetM e tetO e os fenótipos de resistência à eritromicina, clindamicina e tetraciclina. Foram encontrados diferentes índices de resistência aos antibióticos testados: Eritromicina (19,5%), tetraciclina (35,6%), gentamicina (9,3%), clindamicina (20,3%), penicilina (3,4%) e amicacina (38,1%). Todos os isolados foram susceptíveis ceftiofur e cefalotina. Os testes de resistência aos antimicrobianos auxiliam na tomadade decisões relacionadas aos tratamentos, permitindo a escolha mais criteriosa dos antimicrobianos e oacompanhamento espaço-temporal da dinâmica de resistência para este patógeno tão relevante na saúdehumana e animal.(AU)

Efeito da Inclusão de Tortas da Amazônia no Consumo, Digestibilidade, Metabólitos séricos, Desempenho e Emissão de Metano em Ovinos Confinados. Estratégias de Conservação, Extração e Sequenciamento de DNA para Avaliação de Perfil Microbiano Ruminal.

Dois estudos distintos foram conduzidos em momentos e locais diferentes. No primeiro, 3 realizado em Castanhal, Pará, Brasil, avaliou-se os efeitos de dietas contendo tortas 4 Amazônicas (TA) sobre o consumo, digestibilidade, metabólitos séricos, desempenho e 5 emissão de metano em ovinos Dorper-Santa Inês, castrados. Vinte e oito animais foram 6 distribuídos em gaiolas metabólicas, em delineamento inteiramente casualizado, com 7 quatro tratamentos e sete repetições. Cada grupo de animais recebeu dieta composta por 8 silagem de milho (400 g/kg com base na matéria seca (MS)) e concentrado (600 g/kg 9 MS). Os tratamentos foram: controle (CON40), sem adição de torta amazônica e com 40 10 g/kg de extrato etéreo (EE) na MS da dieta total; cupuaçu (Theobroma grandiflorum) 11 (CUP), com inclusão de torta de cupuaçu e 70 g/kg de EE; tucumã (Astrocaryum vulgare 12 Mart.) (TUC), com inclusão de torta de tucumã e 70 g/kg de EE; controle (CON80), sem 13 adição de torta amazônica e com 80 g/kg de EE. As tortas de cupuaçu e tucumã, ao serem 14 incluídas às dietas de ovinos confinados apresentaram efeitos diferentes sobre o consumo, 15 desempenho e emissão de metano. A inclusão de 450 g/kg de cupuaçu em substituição ao 16 milho e ao farelo de soja possibilita consumo e desempenho mais interessantes, inferiores 17 aos tratamentos controle, porém superiores ao observado na inclusão de 309 g/kg de 18 tucumã. No segundo, conduzido em Mosgiel, no Instituto de Pesquisa AgResearch, Nova 19 Zelândia, investigou-se o uso de soluções (solução A, B e C) como métodos alternativos 20 de conservação e extração de DNA ruminal de ovinos para investigação do perfil 21 microbiano, através da técnica genotyping by sequencing (GBS). A qualidade e 22 integridade do DNA e a composição da comunidade microbiana ruminal foram 23 verificadas nos métodos propostos e comparados à um método controle. Amostras 24 ruminais de 151 ovelhas foram coletadas, via tubo estomacal, em dois períodos, com 25 intervalo de duas semanas entre elas (n=302), para determinar a repetibilidade dos 26 métodos. O rendimento, qualidade e integridade do DNA ruminal conservados e extraídos 27 pelos quatro métodos variaram (p < 0,0001), sendo as maiores médias observadas no 28 método controle, Solução B e A. O número de leitura por amostra, da mesma forma, foi 29 influenciado pelo método usado (p < 0,0001). A abundância relativa também foi 30 influenciada pelo método utilizado, no entanto observou-se um padrão na 31 representatividade entre os 61 táxons investigados. A partir dos métodos de conservação 32 e extração de DNA testados neste estudo, foi possível eliminar a etapa de preparação de 33 amostras ruminais utilizada no método controle e obter, com exceção da Solução C, DNA 34 com rendimentos e de qualidades satisfatórias para análises subsequentes.

Two different studies were carried out at different times and locations. In the first one, 45 carried out at Castanhal, Pará, Brazil, the effects of diets containing Amazon cake (AC) 46 on intake, digestibility, serum metabolites, performance and methane emission in 47 castrated Dorper-Santa Inês sheep were evaluated. Twenty-eight animals were distributed 48 in metabolic cages, in a completely randomized design, with four treatments and seven 49 repetitions. Each group of animals received a diet composed of corn silage (400 g/kg as 50 dry matter (DM) basis and concentrate (600 g/kg DM). The treatments were: control 51 (CON40), with no Amazon cake added and with 40 g/kg of ether extract (EE) in the DM 52 of the total diet; cupuaçu (Theobroma grandiflorum) (CUP), cupuaçu cake added and 70 53 g/kg EE; tucumã (Astrocaryum vulgare Mart.) (TUC), tucumã cake added and 70 g/kg 54 EE; control (CON80), with no Amazon cake added and with 80 g/kg EE. Cupuaçu and 55 tucumã pies, when added to sheep diets, had different effects on intake, performance and 56 methane emission. The inclusion of 450 g/kg of cupuaçu to replace corn and soybean 57 meal allows more interesting consumption and performance, lower than the control 58 treatments, but higher than that observed in the inclusion of 309 g/kg of tucumã. In the 59 second, conducted in Mosgiel, at the AgResearch Research Institute, New Zealand, 60 Solutions (solution A, B and C) were investigated as alternative methods of preserving 61 and extracting ruminal sheep DNA for investigating the microbial profile, through of the 62 genotyping by sequencing technique (GBS). The DNA quality and integrity and the 63 composition of the ruminal microbial community were verified in the proposed methods 64 and compared to a control method. Rumen samples from 151 sheep were collected, via 65 stomach tube, in two periods, with an interval of two weeks between them (n = 302), to 66 determine the repeatability of the methods. The yield, quality and integrity of ruminal 67 DNA conserved and extracted by the four methods varied (p <0.0001), with the highest 68 averages observed in the control method, Solution B and A. The number of readings per 69 sample, likewise, was influenced by the method used (p <0.0001). The relative abundance 70 was also influenced by the method used, however there was a pattern in 71 representativeness among the 61 taxa investigated. From the DNA conservation and 72 extraction methods tested in this study, it was possible to eliminate the ruminal samples 73 preparation used in the control method and obtain, with the exception of Solution C, DNA 74 with satisfactory yields and qualities for subsequent analyzes.

Conjugative transfer of resistance determinants among human and bovine Streptococcus agalactiae

Streptococcus agalactiae (GBS) is a major source of human perinatal diseases and bovine mastitis. Erythromycin (Ery) and tetracycline (Tet) are usually employed for preventing human and bovine infections although resistance to such agents has become common among GBS strains. Ery and Tet resistance genes are usually carried by conjugative transposons (CTns) belonging to the Tn916 family, but their presence and transferability among GBS strains have not been totally explored. Here we evaluated the presence of Tet resistance genes (tetM and tetO) and CTns among Ery-resistant (Ery-R) and Ery-susceptible (Ery-S) GBS strains isolated from human and bovine sources; and analyzed the ability for transferring resistance determinants between strains from both origins. Tet resistance and int-Tn genes were more common among Ery-R when compared to Ery-S isolates. Conjugative transfer of all resistance genes detected among the GBS strains included in this study (ermA, ermB, mef, tetM and tetO), in frequencies between 1.10-7 and 9.10-7, was possible from bovine donor strains to human recipient strain, but not the other way around. This is, to our knowledge, the first report of in vitro conjugation of Ery and Tet resistance genes among GBS strains recovered from different hosts.

Insight into the diversity, adaptation and virulence of fish-pathogenic Streptococcus agalactiae strains through transcriptomic and proteomic analysis.

A infecção por Streptococcus agalactiae (GBS) é uma das principais doenças detectadas na piscicultura mundial. Essa bactéria é o principal patógeno de tilápias, uma commodity global do setor aquícola, causando surtos de septicemia e meningoencefalite. Os isolados brasileiros de GBS oriundos de peixes possuem diferentes genótipos quando avaliados pela técnica de MLST, predominando os ST-260, ST-927 e as linhagens não tipáveis. Considerando o relacionamento evolutivo entre esses genótipos e por eles representarem as principais linhagens que infectam peixes no país, se torna necessário entender as características de metabolismo, adaptação e patogenicidade destes grupos genéticos e o seu relacionamento com o hospedeiro aquático. Para avaliar a expressão de transcritos e proteínas dos isolados de GBS, dois experimentos foram conduzidos. O primeiro experimento avaliou o pan-proteoma destes mesmos genótipos, comparou a expressão diferencial de proteínas entre os isolados obtidos de peixes e ser humano usando LC-UDMSE e identificou in silico proteínas antigênicas conservadas que poderiam ser usadas como possíveis alvos para a produção de vacinas. Enquanto que o segundo experimento objetivou avaliar o transcriptoma e o proteoma de uma linhagem de GBS obtido de peixe no Brasil, sendo o experimento conduzido em diferentes temperaturas de cultivo e analisados usando as técnicas de microarranjos e cromatografia líquida associada com espectrometria de massa (LC-HDMSE). No primeiro experimento, um total de 1065 proteínas corresponderam ao pan-proteoma dos isolados de GBS oriundos de peixes, sendo 989 identificadas em todos os isolados simultaneamente (core proteoma), 62 compartilhadas em pelo menos 2 isolados (proteoma acessório) e 14 exclusivamente expressas entre cada amostra. O alto grau de conservação de proteínas entre os isolados avaliados com diferentes STs sugerem que utilização de vacinas monovalentes podem ser efetivas contra as diferentes variantes genéticas circulantes no país. Nós observamos que as proteínas identificadas no pan-proteoma refletem na habilidade adaptativa dos isolados de peixes em responder aos fatores estressantes impostos pelo ambiente aquático e que permitem a sobrevivência e multiplicação bacteriana em peixes. Um total de 215 e 269 proteínas foram up- e down-reguladas, respectivamente, em isolados obtidos de peixes em comparação ao isolado de ser humano. Por fim, independente da similaridade do conteúdo de proteínas, a expressão global de proteínas entre os isolados de GBS obtidos de peixes e ser humano foram diferentes, sugerindo uma distinta adaptação em mamíferos e hospedeiros aquáticos na regulação do proteoma. No segundo experimento, a análise de transcriptoma detectou um total de 107 genes diferencialmente expressos no isolado SA53 a 32 ºC quando comparado com 22 ºC. Enquanto que na análise de proteoma foram detectadas 81 proteínas diferencialmente expressas. Os resultados demonstraram que a temperatura é capaz de regular a expressão diferencial de genes e proteínas, principalmente daquelas envolvidas com a expressão de fatores de virulência, metabolismo, adaptação e resistência ao estresse térmico. Em conjunto os dois experimentos providenciaram novos conhecimentos sobre diversidade, adaptação e virulência de isolados patogênicos de GBS obtidos de peixes através das análises de transcriptoma e proteoma.

Streptococcus agalactiae (GBS) infection is one the main diseases diagnosed in worldwide fish farming. This bacterium is a major pathogen for the Nile tilapia, a global commodity of the aquaculture sector, causing outbreaks of septicemia and meningoencephalitis. The Brazilian GBS fish strains have distinct known genotypes, when evaluated by the MLST technique, predominantly the ST-260, ST-927 and the non-typeable lineage. Considering the evolutionary relationship between these genotypes and for representing the major lineages that infects fish in Brazil, it becomes necessary to understand the specific characteristics of metabolism, adaptation and pathogenicity of these genetic groups as well as their relationships with the aquatic host. In order to evaluate the transcript and protein expression on GBS strains, two experiment trials were performed. The first trial evaluated the pan-proteome of these same genotypes, compared the differential expression of proteins identified between isolates from fish and human using a LC-UDMSE, and identified in silico conserved antigenic proteins that can be used as target in vaccine design. The second trial aimed to evaluate the transcriptome and proteome of a Brazilian fish-adapted GBS strain, being cultured in vitro under different temperatures and analyzed using microarray and liquid chromatography-mass spectrometry label-free shotgun (LC-HDMSE) approaches. In the first trial, a total of 1,065 protein clusters corresponded to pan-proteome of GBS fish strains, being 989 identified in all GBS fish strains (core proteome), 62 shared by at least two strains (accessory proteome) and 14 were exclusively expressed to each strain. The high degree of conservation among strains with different STs suggests that monovalent vaccines may be effective against different genetic variants. We also observed that the identified proteins in pan-proteome reflect the adaptive ability of the GBS fish strains in the response to stress factors imposed by the aquatic environment allowing the bacterial survival and multiplication in the fish host. A total of 215 and 269 proteins from GBS fish strains were up- and down-regulated, respectively, in comparison to human isolate. Regardless of the similarities in protein content, the global protein expression of the GBS human strain was different from the GBS fish strains suggesting distinct adaptations to mammal and fish host at the proteome level. In the second trial, the transcriptomic analysis detected 107 genes as being differentially expressed in SA53 at 32 ºC when compared with 22 ºC. While in proteomic analysis were detected 81 differentially expressed proteins. The results demonstrated that the temperature regulates the differential expression of genes and proteins, mainly those involved with the expression of virulence factors, metabolism, adaptation and bacterial resistance to thermal stress. Together, the two experiments provided news insights into the diversity, adaptation and virulence of fish-pathogenic GBS strains through transcriptomic and proteomic analysis.

Phenotypic and genotypic characterization of Streptococcus agalactiae in pregnant women: first study in a province of Argentina

Group B Streptococcus (GBS) is the leading cause of neonatal infections. Our purpose was to characterize GBS colonization in pregnant women, current serotypes, resistance phenotypes and genes associated with virulence. In Misiones, Argentina, there are no previous data on this topic. Vaginal-rectal swabs from 3125 pregnant women were studied between 2004 and 2010. GBS strains were identified by conventional and serological methods (Phadebact Strep B Test, ETC International, Bactus AB, Sweden). Serotypes were detected using Strep-B Latex (Statens Serum Institut, Denmark). Resistance phenotypes were determined by the double-disk test. Genes were studied by PCR. Maternal colonization was 9.38%. Resistance to erythromycin was 11.6%, and the constitutive phenotype was the predominant one. Serotype Ia was the most frequent, whereas serotypes IV, VI, VII and VIII were not detected. The lmb, bca and hylB genes were detected in more than 79% of the strains. In this study, the colonization rate with GBS and the serotype distribution were compared with studies reported in other areas of the country. The high resistance to erythromycin in Misiones justifies performing antibiotic susceptibility testing. The serotype distribution, the genes encoding putative virulence factors, and the patterns of resistance phenotypes of GBS may vary in different areas. They thus need to be evaluated in each place to devise strategies for prevention.(AU)

Prevalence of Group B Streptococcus serotypes III and V in pregnant women of Rio de Janeiro, Brazil

GBS serotypes III and V were the most prevalent in pregnant women and exhibited resistance to tetracycline, clindamycin and sulfamethoxazole/trimethoprim. Serotype III showed high sialic acid content and PFGE analysis discerned 33 heterogeneous profiles. Phenotypic and genotypic characterization could be relevant to control GBS infections unaffected by intra-partum chemoprophylaxis.(AU)

A combined enrichment/polymerase chain reaction based method for the routine screening of Streptococcus agalactiae in pregnant women

Group B Streptococcus (GBS) is the most common cause of life-threatening infection in neonates. Guidelines from CDC recommend universal screening of pregnant women for rectovaginal GBS colonization. The objective of this study was to compare the performance of a combined enrichment/PCR based method targeting the atr gene in relation to culture using enrichment with selective broth medium (standard method) to identify the presence of GBS in pregnant women. Rectovaginal GBS samples from women at 36 weeks of pregnancy were obtained with a swab and analyzed by the two methods. A total of 89 samples were evaluated. The prevalence of positive results for GBS detection was considerable higher when assessed by the combined enrichment/PCR method than with the standard method (35.9% versus 22.5%, respectively). The results demonstrated that the use of selective enrichment broth followed by PCR targeting the atr gene is a highly sensitive, specific and accurate test for GBS screening in pregnant women, allowing the detection of the bacteria even in lightly colonized patients. This PCR methodology may provide a useful diagnostic tool for GBS detection and contributes for a more accurate and effective intrapartum antibiotic and lower newborn mortality and morbidity.

Descoberta de SNP, construção de mapa genético de alta densidade e identificação de genes associados com adaptação climática e ausência da espinha intermuscular em tambaqui (Colossoma macropomum)

O tambaqui (Colossoma macropomum) é a maior espécie nativa de Characiforme da América do Sul e é encontrado nas bacias do rio Amazonas e Orinoco. O cultivo do tambaqui está crescendo rapidamente no Brasil, sua produção atingiu 139.209 toneladas em 2014, o que corresponde a 57,7% de aumento em relação a 2013. No entanto, poucos estudos genéticos realizados com o tambaqui estão disponíveis atualmente. Estudos genéticos em tambaqui, tanto em populações cultivadas quanto em populações selvagens, necessitam de uma abordagem holística para uma ação racional frente aos desafios ecológicos e mercadológicos na aquicultura. Abordagens baseadas em estudos genéticos têm fornecido ferramentas importantes para se entender a dinâmica populacional, adaptação local e função gênica visando melhorar as estratégias de seleção a serem aplicadas em programas de melhoramento genético. O sequenciamento de nova geração (NGS) permitiu um grande avanço nas abordagens genômicas e transcriptômicas, especialmente relacionadas a espécies não-modelo. A genotipagem por sequenciamento (GBS) é uma dessas abordagens que utilizam enzimas de restrição (REs) para reduzir a complexidade do genoma. Esta tese apresenta a aplicação desta abordagem objetivando proporcionar avanços significativos nos estudos genéticos de base para tambaqui. A técnica de GBS forneceu um painel de SNPs de alta densidade que nos permitiu desenvolver o primeiro mapa de ligação e estudos de associação com variáveis ambientais, adaptação local e ausência de ossos intermusculares no tambaqui. Este trabalho pode nos dar muitas referências teóricas a serem aplicadas em programas de melhoramento genético do tambaqui, permitindo uma melhor compreensão dos processos genéticos relacionados a traços de interesse na aquicultura.

ambaqui (Colossoma macropomum) is the largest native Characiform species from the Amazon and Orinoco river basins of South America. Tambaqui farming is growing rapidly in Brazil, its production reached 139.209 tons in 2014, what corresponds to 57.7% of increase compared with 2013. However, few genetic studies of tambaqui are currently available. The tambaqui genetic studies for cultured and wild populations need a holistic approach for a rational action facing ecological and market challenges in aquaculture. Approaches based on genetic studies have provided important tools to understand population dynamics, local adaptation, and gene function to improve selection strategies to be applied in breeding programs. The next-generation sequencing (NGS) allowed a great advance in genomic and transcriptomic approaches, especially related to non-model species. The genotype-by-sequencing (GBS) is one of this approaches based on genome complexity reduction using restriction enzymes (REs). This thesis presents the application of these approaches to provide advances in the genetic background for tambaqui studies. The GBS approach provided a high-density SNPs panel that allowed us to develop the first linkage map, and association studies with environmental variables, local adaptation, and lack of intermuscular bones, both using tambaqui as a model. This work can give us many theoretical references to be applied in genetic breeding programs for tambaqui, allowing a better understanding of genetic processes related to traits of interest in aquaculture.

EMERGÊNCIA DE Campylobacter jejuni NO SETOR AVÍCOLA E NA SAÚDE PÚBLICA DO BRASIL

Campylobacter jejuni é frequentemente associado a gastroenterites humanas no mundo todo, sendo transmitida pelo consumo de alimentos contaminados, principalmente os de origem animal, com destaque para a carne de frango. A tese foi fracionada em quatro capítulos, sendo o primeiro referente às considerações gerais dos tópicos abordados nos demais capítulos. O segundo capítulo objetivou avaliar as alterações na prevalência, nas características de virulência, na resistência antimicrobiana e na similaridade genética de 99 cepas de C. jejuni isoladas de carcaças de frangos, provenientes de três unidades distintas de uma empresa avícola brasileira exportadora, durante os períodos de 2011-2012 e 2015-2016. O terceiro capítulo teve por objetivo investigar em 30 cepas de C. jejuni isoladas de carcaças de frangos (2015) o potencial para produzir biofilmes isoladamente e em associação a outros agentes nos meios Mueller Hinton e Chicken juice, identificar fatores genéticos ligados à formação de biofilmes, verificar a eficácia de agentes químicos na remoção de estruturas sésseis, analisar a estrutura e composição das matrizes de biofilmes simples e mistos e comparar a similaridade genética entre as cepas. O quarto capítulo objetivou realizar uma análise comparativa relacionada aos genes de virulência e de resistência adaptativa, além da avaliação da homologia genética em 64 cepas de C. jejuni, sendo 44 de origem avícola (2015-2016) e 20 oriundas de pacientes humanos com sintomatologia clínica (2000-2006). A determinação da prevalência restrita ao segundo capítulo foi realizada a partir da análise tradicional de 1070 amostras de carcaças de frangos. A confirmação de C. jejuni foi feita por PCR-multiplex. Para a avaliação da sensibilidade antimicrobiana nas 99 cepas de origem avícola foi realizado o teste de disco difusão. Foi investigada a presença dos genes flaA (motilidade), ciaB (invasão intracelular), cadF (colonização intracelular), pldA (colonização/invasão), cdtABC (citotoxina), luxS (mecanismo quorum-sensing), dnaJ (termotolerância), htrA (auxilia no crescimento sob estresse), cbrA (resistência ao choque osmótico), sodB (tolerância ao estresse oxidativo), cstII e neuA (Síndrome de Guillain-Barré) pela técnica de PCR. A relação filogenética entre os isolados foi determinada pelo método de RAPD-PCR no segundo capítulo e por PFGE no terceiro e quarto capítulos. As análises de formação de biofilmes foram feitas por meio de técnicas de microbiologia tradicional utilizando os meios Mueller Hinton e chicken juice para quantificar, classificar e determinar a constituição da biomassa de biofilmes simples e mistos de 30 cepas de C. jejuni (2015). A morfologia dos biofilmes foi verificada por meio de microscopia eletrônica de varredura. Os testes de inibição das formas sésseis de C. jejuni foram feitos com agentes desinfetantes usualmente utilizados na indústria e com nanopartículas de óxido de zinco. O estudo permitiu concluir que C. jejuni sofre modificações genotípicas e fenotípicas ao longo do tempo de maneira a tornarem-se mais especializadas e com maior virulência. Independente da origem, humana ou avícola, as cepas apresentaram elevado potencial de causar SGB. No ambiente industrial o problema se agrava na persistência de C. jejuni por meio da formação de biofilmes altamente estáveis e resistentes. Os testes de susceptibilidade aos antibióticos e aos desinfetantes na indústria mostram que a exposição constante a esses agentes seleciona cepas mais adaptadas. Logo, há necessidade de implementação de medidas criteriosas de monitoramento dentro da indústria e na saúde pública para o controle de C. jejuni.

Campylobacter jejuni is often associated with human gastroenteritis worldwide, being transmitted by the consumption of contaminated foods, mainly those of animal origin, especially chicken. The thesis was divided in four chapters, the first referring to the general considerations of the topics covered in the other chapters. The second chapter aimed to evaluate the changes in the prevalence, virulence characteristics, antimicrobial resistance and genetic similarity of 99 strains of C. jejuni isolated from chicken carcasses from three different units of a Brazilian export poultry company during the periods between 2011-2012 and 2015-2016. The aim of the third chapter was to investigate the potential to produce biofilms separately and in association with other agents in the Mueller Hinton and Chicken juice media, in 30 strains of C. jejuni isolated from chicken carcasses (2015), identify genetic factors related to the formation of biofilms, verify the effectiveness of chemical agents in the removal of sessile structures, analyze the structure and composition of simple and mixed biofilm matrices, and compare the genetic similarity between the strains. The fourth chapter aimed to perform a comparative analysis related to the genes of virulence and adaptive resistance, in addition to the evaluation of the genetic homology in 64 strains of C. jejuni, 44 of poultry origin (2015-2016) and 20 from human patients with symptomatology (2000-2006). The determination of the prevalence restricted to the second chapter was carried out from the traditional analysis of 1070 samples of chicken carcasses. The confirmation of C. jejuni was done by PCR-multiplex. For the evaluation of antimicrobial susceptibility in the 99 strains of poultry origin, the disc diffusion test was performed. The presence of the genes flaA (motility), ciaB (intracellular invasion), cadF (intracellular colonization), pldA (colonization/invasion), cdtABC (cytotoxin), luxS (quorum-sensing mechanism), dnaJ (thermotolerance), htrA (assistance in growth under stress), cbrA (resistance to osmotic shock), sodB (tolerance to oxidative stress), cstII and neuA (Guillain-Barré Sindrom) by the PCR technique. The phylogenetic relationship between the isolates was determined by the RAPD-PCR method in the second chapter and by PFGE in the third and fourth chapters. Biofilm formation analyzes were performed using traditional microbiology techniques using the Mueller Hinton and Chicken Juice media to quantify, classify and determine the biomass composition of single and mixed biofilms of 30 strains of C. jejuni (2015). The morphology of the biofilms was verified by means of scanning electron microscopy. The inhibition tests of the sessile forms of C. jejuni were made with disinfectants commonly used in industry and with zinc oxide nanoparticles. The study allowed concluding that C. jejuni undergoes genotypic and phenotypic modifications over time in order to become more specialized and with greater virulence. Regardless of human or poultry origin, the strains present a high potential to cause GBS. In the industrial environment the problem is aggravated by the persistence of C. jejuni through the formation of highly stable and resistant biofilms. Antibiotic and disinfectant susceptibilitytests in the industry had shown that constant exposure to these agents selects more adapted strains. Therefore, there is a necessity for the implementation of careful monitoring measures within the industry and in public health for the control of C. jejuni.

DESEMPENHO E CARACTERÍSTICAS DE CARCAÇA DE CORDEIROS ½ DORPER +½ SANTA INÊS ABATIDOS COM DIFERENTES ESPESSURAS DE GORDURA SUBCUTÂNEA

Objetivou-se avaliar o efeito de diferentes espessuras de gordura subcutânea ao abate em cordeiros ½ Dorper + ½ Santa Inês sobre o desempenho (dias de confinamento, idade ao abate, peso corporal inicial, peso corporal final, ganho de peso total, ganho de peso diário, peso corporal ao abate, escore da condição corporal), as características quantitativas da carcaça (peso do corpo vazio, peso da carcaça quente, peso da carcaça fria, perdas por resfriamento, pH da carcaça 0 e 24 horas após o abate, rendimento da carcaça na origem, rendimento da carcaça no frigorifico, rendimento comercial da carcaça, rendimento verdadeiro da carcaça, espessura de gordura subcutânea, índice de compacidade da carcaça, largura da garupa, comprimento da perna e índice de compacidade da perna) e as características dos cortes comerciais (pesos, rendimentos e composição tecidual). Os animais tiveram a espessura de gordura subcutânea avaliada por ultrassonografia, à altura da 12ª costela do antímero esquerdo ao desmame e a cada 15 dias. Após a desmama os cordeiros foram alocados em três grupos experimentais, tendo a espessura de gordura subcutânea ao abate como tratamento (2mm, 3mm e 4mm). Os cordeiros foram alimentados com silagem de milho à vontade e 2% do peso corporal de uma mistura com 75% de milho moído 19% de farelo de soja 1% de ureia e 5% de núcleo comercial. Uma vez atingida espessura de gordura pré-determinada, os animais foram novamente pesados para a obtenção do peso vivo na origem, calculados os dias de confinamento e mensurado o escore de condição corporal, sendo encaminhados ao abatedouro. Após 18 horas em jejum de sólidos foram novamente pesados para a obtenção do peso corporal ao abate. O delineamento experimental utilizado foi o inteiramente casualizado, com três tratamentos e oito repetições. Para realização das análises estatísticas foi utilizado o procedimento GLM do SPSS e as médias comparadas pelo teste Tukey com nível de significância de 5. Não houve efeito dos tratamentos (p>0,05) sobre o peso corporal inicial, pH da carcaça imediatamente após abate e 24 horas após, comprimento interno da carcaça e índice de compacidade da perna. Contudo diferiram (p<0,05) para os dias de confinamento, idade ao abate, peso corporal final, ganho de peso total, ganho de peso diário, peso corporal ao abate, escore da condição corporal, peso do conteúdo gastrintestinal, peso do corpo vazio, peso da carcaça quente, peso da carcaça fria, perdas de peso por resfriamento, rendimento da carcaça na origem, rendimento na carcaça no frigorifico, rendimento comercial da carcaça, rendimento verdadeiro da carcaça, índice de compacidade da carcaça, largura da garupa, comprimento da perna. A porcentagem dos cortes em relação a meia carcaça; pescoço (5,62%); paleta (18,49%), costilhar (29,16%), lombo (12,15%) e perna (34,91%) não diferiam entre as EGS (p<0,05). Os pesos dos cortes apresentaram diferenças estatísticas entre os tratamentos (p<0,05). Quanto a composição tecidual dos cortes, apenas a musculatura do pescoço, osso do pescoço, ossos do lombo e de ossos da perna, apresentaram diferença estatística entre as espessuras de gordura subcutânea (p<0,05), sendo que os demais tecidos (gordura, ossos, resíduo e músculo) não ii apresentaram diferenças nos outros cortes. Devido a apresentarem melhores rendimentos de cortes e carcaça, além de ganho de peso médio diário satisfatório, recomenda-se o abate dos cordeiros ½ Dorper + ½ Santa Inês com 4mm de espessura de gordura subcutânea.

The objective of this study was to evaluate the effect of different subcutaneous fat thicknesses on slaughter in ½ Dorper + ½ Santa Inês lambs on performance (days of confinement, age at slaughter, initial live weight, final live weight, total weight gain, weight gain daily, live weight at slaughter, body condition score), the quantitative characteristics of the carcass (empty body weight, warm carcass weight, cold carcass weight, cooling losses, carcass pH 0 and 24 hours after slaughter, yield carcass yield in the refrigerator, commercial carcass yield, true carcass yield, subcutaneous fat thickness, carcass compatability index, croup width, leg length and leg compatability index) and the characteristics of the carcass. commercial cuts (weights, yields and tissue composition). Twenty-four recently weaned lambs with a mean age of 86 days were used. In the work the animals had their thickness of subcutaneous fat evaluated by ultrasonography at the height of the 12th rib of the left antimer of the animal. After weaning the lambs were allocated in three experimental groups, with the subcutaneous fat thickness at slaughter as treatment (2mm, 3mm and 4mm). After division of the groups the lambs were fed corn silage at will and 2% of the body weight of a mixture with 75% ground corn, 19% soybean meal, 1% urea and 5% commercial core. After the treatment was started, the animals were evaluated biweekly with the aid of an ultrasound device, until they reached the predetermined fat thickness for slaughter. Once this fat thickness was reached, the animals were again weighed to obtain the live weight at the origin, calculated the days of confinement and measured the body condition score, being sent to the slaughterhouse. After 18 hours in solids fasting the animals were again weighed to obtain live weight at slaughter. The experimental design was a completely randomized design with three treatments and eight replicates. Statistical analysis was performed using the SPM GLM procedure. For comparison of means the significance level of 5% was considered by the Tukey test. There was no effect of the treatments (p> 0.05) on the initial live weight, carcass pH immediately after slaughter and 24 hours afterwards, internal carcass length and leg compactness index. However, the confinement days, age at slaughter, final live weight, total weight gain, daily weight gain, live weight at slaughter (p <0.05) as a function of fat thickness for subcutaneous fat thickness by ultrasonography differed , body condition score, weight of the gastrointestinal content, empty body weight, warm carcass weight, cold carcass weight, cooling weight losses, carcass yield at the iv origin, carcass yield in the refrigerator, commercial yield of the carcass, yield true of carcass, carcass compactness index, croup width, leg length. The percentage of cuts in relation to half carcass; neck (5.62%); shoulder (18.49%), ribs (29.16%), loin (12.15%) and leg (34.91%) did not differ between the GBS (p <0.05). The weights of the cuts presented statistical differences between treatments (p <0.05). As for the tissue composition of the cuts, only the neck muscles, neck bone, loin bones and leg bones presented a statistical difference between the thicknesses of subcutaneous fat (p <0.05). Other tissues (fat, bones, residue and muscle) showed no differences in other cuts. Due to better yields of cuts and carcass, in addition to satisfactory average daily weight gain, it is recommended to slaughter ½ Dorper + ½ Santa Inês lambs with 4mm thick subcutaneous fat.

PREVALÊNCIA E RESISTÊNCIA AOS ANTIMICROBIANOS DE Campylobacter ISOLADAS DE CARCAÇAS DE FRANGOS COMERCIALIZADAS NO BRASIL

Campylobacter é o agente zoonótico mais envolvido na gastroenterite humana de causa bacteriana nos países desenvolvidos. Além do quadro diarreico, consequente da infecção por esse micro-organismo, algumas complicações graves podem acometer indivíduos infectados como sepse, aborto, meningite, abscessos e a Síndrome de Guillain-Barré (SGB). Esse dado é de importância significativa na saúde pública, sendo este micro-organismo reconhecido como patógeno emergente, amplamente distribuído pela carne de aves. A alta incidência de enfermidades relacionadas a este micro-organismo em humanos na Europa e nos Estados Unidos da América remete à necessidade de conhecimento mais amplo referente à importância desse agente como patógeno alimentar no Brasil. O primeiro capítulo apresenta considerações gerais e suporte teórico para o melhor entendimento do segundo capítulo. O segundo capítulo objetivou determinar a prevalência de Campylobacter em carcaças de frango comercializadas no Brasil. Foram analisadas 246 carcaças de frango, congeladas e resfriadas, representativas das marcas comercializadas no país, sob diferentes tipos de inspeção sanitária, habilitadas para o comércio interno e/ou exportação. Os isolados do gênero foram identificados como C. jejuni, C. coli ou Campylobacter spp., e após, verificada a suscetibilidade aos antimicrobianos e discutido o perigo potencial que representam à saúde pública. Os resultados obtidos foram utilizados para criação de perfis de resistência e para estabelecer determinantes para a alta positividade de Campylobacter nas carcaças de frango analisadas.

Campylobacter is the most involved zoonotic agent in human bacterial gastroenterite in developed countries. Besides diarrheal framework, resulting from infection by this microorganism, some serious complications can affect population as sepsis, abortion, meningitis, abscesses and Guillain-Barré syndrome (GBS). This information is significant in public health, and this micro-organism is recognized as an emerging pathogen, widely distributed by poultry. The high incidence of diseases related to this micro-organism in humans in Europe and at United States refers to the broader need for knowledge concerning the importance of this agent as a foodborne pathogen in Brazil. The first chapter presents general considerations and theoretical support for understanding the second chapter. The second chapter aimed to determine the prevalence of Campylobacter in poultry carcasses commercialized in Brazil. We analyzed 246 carcasses, frozen and chilled, representative of brands made in the country by different types of sanitary inspection, qualified to internal trade or export. Isolates of gender were identified as C. jejuni, C. coli or Campylobacter spp. The antimicrobial susceptibility was checked and discussed the potential they represent to public health. The results were used to create profiles and resistance determinants to establish a higher positivity of Campylobacter in analyzed poultry carcasses.

Detection of Group B Streptococcus in Brazilian pregnant women and antimicrobial susceptibility patterns

Group B Streptococcus (GBS) is still not routinely screened during pregnancy in Brazil, being prophylaxis and empirical treatment based on identification of risk groups. This study aimed to investigate GBS prevalence in Brazilian pregnant women by culture or polymerase chain reaction (PCR) associated to the enrichment culture, and to determine the antimicrobial susceptibility patterns of isolated bacteria, so as to support public health policies and empirical prophylaxis. After an epidemiological survey, vaginal and anorectal specimens were collected from 221 consenting laboring women. Each sample was submitted to enrichment culture and sheep blood agar was used to isolate suggestive GBS. Alternatively, specific PCR was performed from enrichment cultures. Antimicrobial susceptibility patterns were determined for isolated bacteria by agar diffusion method. No risk groups were identified. Considering the culture-based methodology, GBS was detected in 9.5% of the donors. Twenty five bacterial strains were isolated and identified. Through the culture-PCR methodology, GBS was detected in 32.6% specimens. Bacterial resistance was not detected against ampicillin, cephazolin, vancomycin and ciprofloxacin, whereas 22.7% were resistant to erythromycin and 50% were resistant to clindamycin. GBS detection may be improved by the association of PCR and enrichment culture. Considering that colony selection in agar plates may be laboring and technician-dependent, it may not reflect the real prevalence of streptococci. As in Brazil prevention strategies to reduce the GBS associated diseases have not been adopted, prospective studies are needed to anchor public health policies especially considering the regional GBS antimicrobial susceptibility patterns.