Larissa Pickler

Avaliação microbiológica, histológica e imunológica de frangos de corte desafiados com Salmonella Enteritidis e Minnesota e tratados com ácidos orgânicos

Two experiments were carried out to evaluate effectiveness of organic acids against Salmonella enterica enterica serovars Enteritidis (SE) and Minnesota (SM) in broilers. In the first experiment three treatments were evaluated: T1 - feeding with organic acids, T2 - feeding with organic acids and organic acids in drink water, and T3 - control group. All animals were oral challenged with SE. Organic acids in diet (T1) and organic acids in diet and drink water (T2) reduced the shadding of Salmonella in crop and cecum 7 days post challenged with SE and reduced the CD3+ cells in jejunal mucosa of broilers. In the second experiment four treatments were evaluated, T1 - control group, T2 - control group oral challenged with Salmonella Minnesota (SM); T3 - oral challenged animals with SM and treated with organic acids in diet; T4 - oral challenged animals with SM and treated with organic acids in diet and in drink water. Organic acids in diet (T3) and organic acids in diet and in drink water (T4) reduced the shadding of SM in crop of challenged broilers, 7 days post inoculation The use of organic acids in diet and in water was more effective to control SE than SM.

Óleo essencial de orégano, alecrim, canela e extrato de pimenta no controle de Salmonella, Eimeria e Clostridium em frangos de corte

The efficiency of a product in broiler feed containing essential oil of oregano, rosemary, cinnamon and extract of red pepper (plant compost) in the control of Salmonella, Eimeria and Clostridium was evaluated. Two experiments were carried out to evaluate the product. In the first experiment the efficiency of this product to control Clostridium perfringens after challenge with Eimeria acervulina, E. maxima and E. tenella was assessed. Day old chicks were allotted into three groups: T1 - control diet without growth promoter, T2 - diet with avilamycin (10ppm), and T3 - diet with addition of the plant compost (100ppm). The use of the plant compost in broiler diets reduced specific lesions of E. maxima and E. tenella at 14 days after inoculation and reduced the count of colony forming units (CFU) of Clostridium perfringens in the ceca comparing to the control group. In the second trial the efficiency of the same product in birds challenged with Salmonella Enteritidis was evaluated. Day old birds were submitted to three experimental diets: T1 - control diet without antibiotics growth promoter, T2 - diet with 10ppm Avilamycin, T3 - diet with 100ppm of the plant compost mentioned above. At 21 days of age all birds were inoculated with 105 CFU of Salmonella Enteritidis. The use of the plant compost and avilamycin decreased the excretion of Salmonella in poultry 72 hours after the inoculation. The use of the plant compost increased villous/CD3+ cells in the duodenum, compared to group avilamycin and control, but had no effect on the expression of these cells in the cecum.

Identification of strain-specific sequences that distinguish a Mycoplasma gallisepticum vaccine strain from field isolates

ABSTRACT Despite attempts to control avian mycoplasmosis through management, vaccination, and surveillance, Mycoplasma gallisepticum continues to cause significant morbidity, mortality, and economic losses in poultry production. Live attenuated vaccines are commonly used in the poultry industry to control avian mycoplasmosis; unfortunately, some vaccines may revert to virulence and vaccine strains are generally difficult to distinguish from natural field isolates. In order to identify genome differences among vaccine revertants, vaccine strains, and field isolates, whole-genome sequencing of the M. gallisepticum vaccine strain ts-11 and several “ts-11-like” strains isolated from commercial flocks was performed using Illumina and 454 pyrosequencing and the sequenced genomes compared to the M. gallisepticum Rlow reference genome. The collective contigs for each strain were annotated using the fully annotated Mycoplasma reference genome. The analysis revealed genetic differences among vlhA alleles, as well as among genes annotated as coding for a cell wall surface anchor protein (mg0377) and a hypothetical protein gene, mg0359, unique to M. gallisepticum ts-11 vaccine strain. PCR protocols were designed to target 5 sequences unique to the M. gallisepticum ts-11 strain: vlhA3.04a, vlhA3.04b, vlhA3.05, mg0377, and mg0359. All ts-11 isolates were positive for the five gene alleles tested by PCR; however, 5 to 36% of field isolates were also positive for at least one of the alleles tested. A combination of PCR tests for vlhA3.04a, vlhA3.05, and mg0359 was able to distinguish the M. gallisepticum ts-11 vaccine strain from field isolates. This method will further supplement current approaches to quickly distinguish M. gallisepticum vaccine strains from field isolates.

Avaliação da resposta imunológica da mucosa intestinal de frangos de corte desafiados com diferentes sorovares de Salmonella

The study was designed to compare the effect of different Salmonella serovars in immune response across the count of CD8+ cells, CD4+ cells, goblet cells and macrophages in the gut mucosa of broilers. During the experimental inoculation at 7 day-old were used Salmonella enterica subspecies enterica sorovars Enteritidis, Typhimurium, Senftenberg, Mbandaka and Minnesota. It was observed that all serovars tested were capable of contaminating the poultry being possible counts of Salmonella in cloacal swabs, 48 h after inoculation and into the crop and cecum, at 14 and 20 day-old. Serovars tested had different effects on broiler performance assessed at 20 days. In the mucosa of the ileum and cecum of broilers, it was observed that some of the serotypes increased CD8 + cells, CD4 + cells, goblet cells and macrophages compared to the negative control group both at 14 and at 20 day-old. S. Enteritidis and S. Typhimurium are the serovars that showed the more intense effect in live performance and in the immune system of birds showing pathogenic characteristic; generally the broilers of the negative control showed significantly less immune cells on the intestinal mucosa than broilers inoculated experimentally. However, it was found that the Salmonella serovars used in this study had different effects on the cellular dynamics of the mucosa of the ileum and cecum and differently affect weight gain and average daily gain of poultry showing different levels of pathogenicity.

Uso de probiótico sobre a ativação de células T e controle de Salmonella Minnesota em frangos de corte

Para avaliar o efeito do probiotico sobre a resposta imunologica de frangos de corte desafiados com Salmonella Minnesota (SM), 60 frangos foram divididos em tres grupos: CN- (controle negativo) aves que nao foram inoculadas com SM, CP- (controle positivo) aves inoculadas com SM e Probiotico- aves suplementadas na racao com probiotico composto de Lactobacillus acidophilus, L. plantarium, L. rhamnosus, L. bulgaricus, Enterococcus faecium, Streptococcus thermophilus e Bifidobacterium bifidum e desafiadas com SM. Aos 14 dias foi realizada a inoculacao com SM e aos 7 e 35 dias foram quantificadas celulas caliciformes, CD4+ e CD8+ na mucosa intestinal do ileo e ceco. Aves suplementadas com probioticos aos 7 dias de idade apresentaram aumento significativo (P≤0,05) de celulas caliciformes e CD4+ no ileo e de celulas CD8+ no ceco. Aos 35 dias houve aumento significativo (P≤0,05) das celulas CD8+ nas aves inoculadas do CN e Probiotico. A utilizacao de probioticos proporcionou reducao significativa (P≤0,05) da contagem de Salmonella sp.