Region-Specific Decellularization of Porcine Uterine Tube Extracellular Matrix: A New Approach for Reproductive Tissue-Engineering Applications.

The uterine tube extracellular matrix is a key component that regulates tubal tissue physiology, and it has a region-specific structural distribution, which is directly associated to its functions. Considering this, the application of biological matrices in culture systems is an interesting strategy to develop biomimetic tubal microenvironments and enhance their complexity. However, there are no established protocols to produce tubal biological matrices that consider the organ morphophysiology for such applications. Therefore, this study aimed to establish region-specific protocols to obtain decellularized scaffolds derived from porcine infundibulum, ampulla, and isthmus to provide suitable sources of biomaterials for tissue-engineering approaches. Porcine uterine tubes were decellularized in solutions of 0.1% SDS and 0.5% Triton X-100. The decellularization efficiency was evaluated by DAPI staining and DNA quantification. We analyzed the ECM composition and structure by optical and scanning electronic microscopy, FTIR, and Raman spectroscopy. DNA and DAPI assays validated the decellularization, presenting a significative reduction in cellular content. Structural and spectroscopy analyses revealed that the produced scaffolds remained well structured and with the ECM composition preserved. YS and HEK293 cells were used to attest cytocompatibility, allowing high cell viability rates and successful interaction with the scaffolds. These results suggest that such matrices are applicable for future biotechnological approaches in the reproductive field.

Decellularized Bovine Skeletal Muscle Scaffolds: Structural Characterization and Preliminary Cytocompatibility Evaluation.

Skeletal muscle degeneration is responsible for major mobility complications, and this muscle type has little regenerative capacity. Several biomaterials have been proposed to induce muscle regeneration and function restoration. Decellularized scaffolds present biological properties that allow efficient cell culture, providing a suitable microenvironment for artificial construct development and being an alternative for in vitro muscle culture. For translational purposes, biomaterials derived from large animals are an interesting and unexplored source for muscle scaffold production. Therefore, this study aimed to produce and characterize bovine muscle scaffolds to be applied to muscle cell 3D cultures. Bovine muscle fragments were immersed in decellularizing solutions for 7 days. Decellularization efficiency, structure, composition, and three-dimensionality were evaluated. Bovine fetal myoblasts were cultured on the scaffolds for 10 days to attest cytocompatibility. Decellularization was confirmed by DAPI staining and DNA quantification. Histological and immunohistochemical analysis attested to the preservation of main ECM components. SEM analysis demonstrated that the 3D structure was maintained. In addition, after 10 days, fetal myoblasts were able to adhere and proliferate on the scaffolds, attesting to their cytocompatibility. These data, even preliminary, infer that generated bovine muscular scaffolds were well structured, with preserved composition and allowed cell culture. This study demonstrated that biomaterials derived from bovine muscle could be used in tissue engineering.

Heat stress reduces Eimeria spp. infection and interferes with C. perfringens infection via activation of the hypothalamic-pituitary-adrenal axis.

Heat stress has a relevant effect on animal health and productivity. Stress and environmental changes can contribute to disease development, such as avian necrotic enteritis (NE). The goal of this study was to analyze the effects of heat stress applied to broiler chickens in an experimental model of co-infection with Clostridium perfringens and Eimeria spp. Therefore, the current study was designed to analyze the effect of heat stress to broiler chickens in an experimental model of infection or co-infection with Clostridium perfringens and Eimeria spp. C. perfringens was given in the poultry feed and the Eimeria infection was induced by gavage with a live oocysts vaccine dose 30 times higher than the manufacturer recommendation. We observed a reduction in the secretory IgA concentration in the jejunum and ileum in heat-stressed chickens compared to non-stressed chickens. Decreased maximum scores of intestinal necrosis, crypt abscesses and transmural lesions were observed in the heat-stressed chickens co-infected and infected with Eimeria compared to the respective unstressed groups. Heat stress caused an increase the intestinal lesion scores in chickens infected with C. perfringens only. The crypt depth was greater in chickens from the heat-stressed groups compared to the non-stressed groups. We also demonstrated that HS decreased infection and/or Eimeria development in the intestinal epithelium, reducing the harmful potential of C. perfringens.

Heat Stress Modulates Brain Monoamines and Their Metabolites Production in Broiler Chickens Co-Infected with Clostridium perfringens Type A and Eimeria spp.

Heat stress has been related to the impairment of behavioral and immunological parameters in broiler chickens. However, the literature is not clear on the involvement of neuroimmune interactions in a heat stress situation associated with bacterial and parasitic infections. The present study evaluated the production of monoamines and their metabolites in brain regions (rostral pallium, hypothalamus, brain stem, and midbrain) in broiler chickens submitted to chronic heat stress and/or infection and co-infection with Eimeria spp. and Clostridium perfringens type A. The heat stress and avian necrotic enteritis (NE) modulated the neurochemical profile of monoamines in different areas of the central nervous system, in particular, those related to the activity of the hypothalamus-hypophysis-adrenal (HPA) axis that is responsible for sickness behavior. C. perfringens and/or Eimeria infection, heat stress increased 5-hydroxytryptamine (5-HT), 4,4 dihydroxyphenylacetic acid (DOPAC), and DOPAC/dopamine (DA) in the rostral pallium; 3-methoxy-4-hydroxyphenylethylene glycol (MHPG), homovanillic acid (HVA), HVA/DA, DOPAC/DA, and 5-hydroxyindoleacetic acid (5-HIAA)/5-HT in the hypothalamus; MHPG, 5-HIAA/5-HT, DOPAC/DA, and HVA/DA in the midbrain; and MHPG, DOPAC, HVA, HVA/DA, DOPAC/DA, and 5-HIAA/5-HT in the brainstem. Heat stress decreased noradrenaline + norepinephrine (NOR + AD) in all brain regions analyzed; 5-HT in the hypothalamus, midbrain, and brainstem; and DA in the midbrain. The results also showed the existence and activity of the brain-gut axis in broiler chickens. The brain neurochemical profile and corticosterone production are consistent with those observed in chronic stressed mammals, in animals with sickness behavior, and an overloading of the HPA axis.

Pandemic extra-intestinal pathogenic Escherichia coli (ExPEC) clonal group O6-B2-ST73 as a cause of avian colibacillosis in Brazil.

Extra-intestinal pathogenic Escherichia coli (ExPEC) represent an emerging pathogen, with pandemic strains increasingly involved in cases of urinary tract infections (UTIs), bacteremia, and meningitis. In addition to affecting humans, the avian pathotype of ExPEC, avian pathogenic E. coli (APEC), causes severe economic losses to the poultry industry. Several studies have revealed overlapping characteristics between APEC and human ExPEC, leading to the hypothesis of a zoonotic potential of poultry strains. However, the description of certain important pandemic clones, such as Sequence Type 73 (ST73), has not been reported in food sources. We characterized 27 temporally matched APEC strains from diverse poultry farms in Brazil belonging to the O6 serogroup because this serogroup is frequently described as a causal factor in UTI and septicemia in humans in Brazil and worldwide. The isolates were genotypically characterized by identifying ExPEC virulence factors, phylogenetically tested by phylogrouping and multilocus sequence type (MLST) analysis, and compared to determine their similarity employing the pulsed field gel electrophoresis (PFGE) technique. The strains harbored a large number of virulence determinants that are commonly described in uropathogenic E. coli (UPEC) and sepsis associated E. coli (SEPEC) strains and, to a lesser extent in neonatal meningitis associated E. coli (NMEC), such as pap (85%), sfa (100%), usp (100%), cnf1 (22%), kpsMTII (66%), hlyA (52%), and ibeA (4%). These isolates also yielded a low prevalence of some genes that are frequently described in APEC, such as iss (37%), tsh, ompT, and hlyF (8% each), and cvi/cva (0%). All strains were classified as part of the B2 phylogroup and sequence type 73 (ST73), with a cluster of 25 strains showing a clonal profile by PFGE. These results further suggest the zoonotic potential of some APEC clonal lineages and their possible role in the epidemiology of human ExPEC, in addition to providing the first description of the O6-B2-ST73 clonal group in poultry.

Effects of heat stress on the formation of splenic germinal centres and immunoglobulins in broilers infected by Clostridium perfringens type A.

Avian necrotic enteritis (NE) induced by Clostridium perfringens is a disease that affects mainly the first weeks of poultry's life. The pathogenesis of NE is complex and involves the combination of several factors, such as co-infection with different species of coccidia, immunosuppression and stress. Stress is one of the main limiting factors in poultry production. Although several studies emphasized the effects of stress on immunity, few works analyzed these effects on immunoglobulins and on germinal centres (GCs), which are specialized microenvironments, responsible for generating immune cells with high affinity antibodies and memory B-lymphocytes. Thus, the effects of heat stress associated or not with thioglycolate broth culture medium intake and/or C. perfringens infection on corticosterone serum levels, spleen GCs development and immunoglobulin production in broilers were evaluated. Results showed that heat stress, thioglycolate and C. perfringens per se increased corticosterone serum levels, although this was not observed in heat stressed and thioglycolate and C. perfringens-treated chickens. The serum levels of IgA, IgM and IgY were differently affected by heat stress and/or infection/thioglycolate. Heat stress decreased the duodenal concentrations of sIgA, which was accompanied by a reduction in GCs number in the duodenal lamina propria; a trend to similar findings of sIgA concentrations was observed in the chickens' jejunum. Changes in spleen and Bursa of Fabricius relative weights as well as in spleen morphometry were also noted in heat stressed animals, infected or not. Together, these data suggest that heat stress change GCs formation in chickens infected or not, which that may lead to failures in vaccination protocols as well as in the poultries' host resistance to infectious diseases during periods of exposure to heat stress.

A survey on gram-negative bacteria in saffron finches (Sicalis flaveola) from illegal wildlife tradein Brazil / Pesquisa de bactérias gram-negativas em canários-da-terra (Sicalis flaveola) resgatados do tráfico ilegal de aves no Brasil

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

No Estado de São Paulo, Brasil, os pássaros como os canários-da-terra têm sido uma das espécies mais frequentemente resgatadas do tráfico ilegal e enviadas aos centros de vida selvagem. Em situações de estresse estas aves podem ser acometidas por infecções causadas por bactérias oportunistas. Este fato é de grande importância quando é planejada da reintrodução das aves na natureza. O presente trabalho foi delineado para avaliar o estado de saúde de canários-da-terra resgatados do tráfico ilegal. Foram colhidas soabes da traqueia e da cloaca de 100 aves resgatadas durante os anos de 2012 e 2013. Os resultados obtidos revelaram alta frequência de bactérias gram-negativas nas fezes e no orofaringe dos animais, com maior frequência para os membros da família Enterobacteriaceae (97,5%). Os gêneros mais frequentes foram Escherichia coli (46,55) e Klebsiella pneumoniae (10,4%). Outros microorganismos incluindo Enterobacter cloacae, Serratia liquefaciens, Serratia spp, Klebsiella oxytoca e Citrobacter freundii também foram isolados em menor frequencia de aves assintomáticas. A presença de estirpes de Escherichia coli enteropagênicas (EPEC) e as produtoras da toxina de Shiga confirmam o risco de zoonose e a importância para saúde pública deste tipo de ave.(AU)

Effects of cold stress and Salmonella Heidelberg infection on bacterial load and immunity of chickens.

We analysed the effects of cold stress (19 ± 1°C, 6 h /day, from the first to the seventh day of life) applied to specific pathogen free (SPF) chickens. On experimental Day 1 (ED1), chicks were divided into four groups: C (not infected and kept under thermoneutral condition); CS (not infected and cold stressed); PC (Salmonella Heidelberg (SH) infected and kept under thermoneutral condition) and PCS (SH infected and cold stressed). High concentrations of corticosterone were found in the cold stressed birds on ED7 and ED21, with a greater increase in birds of the PCS group. Stress or non-stressed SH-infected birds had high levels of norepinephrine on ED21. On ED21, an increased percentage and number of SH were found in birds of the PCS group. On ED7, a decrease in macrophages presenting MHCII, CD8(+) and CD8(+) γδ cells was observed in the chickens of the CS group. Decrease was observed in CD3(+) cells in the birds of the PCS group and increase in macrophages presenting MHCII cells and of the CD4(+)/CD8(+) ratio in chickens of the CS group on ED21. There was a decrease in CD8(+) γδ cells in birds of the CS group on ED21 and in the CD3(+) and CD8(+)cell numbers in chickens of the PCS group on ED21. Our results suggest that cold stress applied to chickens in the first 7 days of life increases both the hypothalamus pituitary adrenal axis and the sympathetic nervous system activities, leading to long-term immune cell dysfunction, thus allowing increased SH invasion and persistence within the birds' body.

Persistence and spreading of field and vaccine strains of infectious laryngotracheitis virus (ILTV) in vaccinated and unvaccinated geographic regions, in Brazil.

Infectious laryngotracheitis (ILT) is a highly infectious respiratory disease that causes morbidity and mortality in commercial chickens. Despite the use of attenuated vaccines, ILT outbreaks have been described in broiler and long-lived birds. Molecular approaches, including polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, are used to characterize ILT viruses (ILTVs) detected in vaccinated and unvaccinated geographical regions. As part of an ILT control program implemented in a region of commercial layer production, samples of conjunctiva, trachea, and trigeminal ganglia were collected from chickens in a vaccinated and quarantined region over a period of 8 years after initiation of vaccination. To determine the origin of new ILT outbreaks in unvaccinated regions, samples collected from ill chickens were also analyzed. Chicken embryo origin (CEO) vaccine viruses and the Bastos field strain were detected circulating in healthy chickens in the vaccinated region. CEO strains and field viruses molecularly related to the Bastos strain were also detected outside of the quarantined region in chickens showing clinical signs of ILT. This study reveals the persistence and circulation of a wild field strain, despite the intensive use of tissue culture origin (TCO) and CEO vaccines in a quarantined region. Spreading of CEO viruses to unvaccinated regions and the capacity of this virus to establish latent infections and cause severe outbreaks were also observed.

Clostridium perfringens type A enteritis in blue and yellow macaw (Ara ararauna).

This study describes an outbreak of necrotic enteritis caused by Clostridium perfringens type A in captive macaws (Ara ararauna). Two psittacine birds presented a history of prostration and died 18 hr after manifestation of clinical signs. The necropsy findings and histopathologic lesions were indicative of necrotic enteritis. Microbiologic assays resulted in the growth of large gram-positive bacilli that were identified as C. perfringens. PCR was used to identify clostridium toxinotypes and confirmed the identification of isolated strains as C pefringens type A, positive to gene codifying beta 2 toxin. The infection source and predisposing factors could not be ascertained.

Prevalence of avian pathogenic Escherichia coli (APEC) clone harboring sfa gene in Brazil.

Escherichia coli sfa+ strains isolated from poultry were serotyped and characterized by polymerase chain reaction (PCR) and amplified fragment length polymorphism (AFLP). Isolates collected from 12 Brazilian poultry farms mostly belonged to serogroup O6, followed by serogroups O2, O8, O21, O46, O78, O88, O106, O111, and O143. Virulence genes associated were: iuc 90%, fim 86% neuS 60%, hly 34%, tsh 28%, crl/csg 26%, iss 26%, pap 18%, and 14% cnf. Strains from the same farm presented more than one genotypic pattern belonging to different profiles in AFLP. AFLP showed a clonal relation between Escherichia coli sfa+ serogroup O6. The virulence genes found in these strains reveal some similarity with extraintestinal E. coli (ExPEC), thus alerting for potential zoonotic risk.

Detection of chicken anemia virus and infectious bursal disease virus co-infection in broilers / Detecção do virus da anemia das galinhas em coinfecção com o vírus doença infecciosa bursal em frangos

This survey aimed to investigate chicken anemia virus (CAV) in broilers flocks experimenting retarded growth and increasing mortality since the fourth day of age. Clinically, chickens presented depression, paleness, depigmentation and retarded growth. At necropsy, chickens presented CAV-compatible lesions. Samples from liver, spleen and thymus were tested by PCR for a 675-bp fragment of the CAV VP-1 gene, and all tested samples were positive. Serological and molecular techniques did not detect other pathogens, such as adenovirus, reovirus, astrovirus, infectious bursal disease and avian infectious bronchitis virus. These results showed that chicken anemia virus (CAV) may occur since the first few days of life in broilers - a fact not as yet reported -, associated with high pathogenic Infectious Bursal Disease Virus (IBDV) vaccine strain may induce a persistent growth retarded for several weeks in broilers.

Este estudo investigou a manifestação do vírus da Anemia Infecciosa das Aves (VAIA) em lotes de frangos que apresentavam retardo no crescimento e aumento da mortalidade observado a partir do quarto dia de idade. Clinicamente, as aves apresentavam depresão, palidez, despigmentação e retardo de crescimento. À necropsia, as aves apresentavam lesões compatíveis com a infecção pelo vírus da Anemia infecciosa das aves (VAIA). Amostras de fígado, baço e timo foram examinadas por PCR que amplifica um frangmento de 675 pb do gene VP-1 do VAIA. Todos os órgãos examinados foram positivos para o vírus da Anemia Infecciosa das Aves. Os demais patógenos, como adenovírus, reovírus, astrovírus, vírus da doença infecciosa bursal e coronavírus aviário não foram detectados pelas diferentes técnicas laboratoriais, como sorologia, PCR ou PAGE. Os resultados mostraram que o vírus da Anemia Infecciosa das Aves (VAIA) pode manifestar-se clinicamente nos primeiros dias de vida dos frangos – um fato ainda não reportado – associado ao vírus vacinal da doença infecciosa bursal (DIB) cepa forte pode induzir um persistente retardo de crescimento, por várias semanas, em frangos.

Caracterização molecular dos fatores de virulência de estirpes de Escherichia coli isoladas de papagaios com colibacilose aviária / Molecular characterization of virulence factors in Escherichia coli strains isolated from parrots with colibacilosis

Oito amostras de Escherichia coli isoladas de papagaios com colibacilose aviária foram sorogrupadas e investigadas para a presença dos fatores de virulência: pili associado a pielonefrite (pap), fímbria S (sfa), adesina afimbrial (afa), cápsula K1 (neu), curli (crl, csgA), hemaglutinina termosensível(tsh), enterotoxinas termo-lábil (LT) e termo-estável (STa eSTb), Shiga-like toxinas (Stx1 e Stx2), Fator citotóxico necrotizante(cnf1), hemolisina (hly), aerobactina (iuc) e resistência sérica (iss). Os resultados mostraram que os isolados pertenciam a seis sorogrupos:O23; O54; O64; O76; O128 e O152. Os genes de virulência detectados foram: crl+ em todos os isolados; pap+; iss+ e iuc+ em três isolados, tsh+em dois isolados. Todas as amostras foram negativas para os genes neu, csgA, sfa, afa, hly, cnf e para as toxinas LT, STa, STb, Stx1 e Stx2.Estes resultados sugerem que amostras de E. coli isoladas de papagaios apresentam alguns fatores de virulência das amostras do patotipo de E. coli patogênica para aves (APEC).

A total of eight Escherichia. coli isolates from psittacine birds were serogrouping and investigated for the virulence factors: pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afa), capsule K1 (neu), curli fibers (crl, csgA), temperature-sensitive hemagglutinin (tsh), heat labile (LT) and heat stable (STa and STb)enterotoxins, Shiga-like toxins (Stx1 and Stx2), Cytotoxic necrotizing factor (cnf1), haemolysin (hly), aerobactin production (iuc) and serum resistance (iss). The results showed that the isolates belonged to six serogroups: O23; O54; O64; O76; O128 and O152. The found virulence genes were: crl+ in all isolates, pap+, iuc+ and iss+ in three isolates; tsh+ in two isolates. All strains were negative for genes neu,csgA, sfa, afa, hly, cnf and LT, STa, STb, Stx1, Stx2 toxins. Our findings suggested that some E. coli isolated from psittacine birds present some virulence factors of avian pathogenic E. coli (APEC) pathotype.

Some adhesins of avian pathogenic Escherichia coli (APEC) isolated from septicemic poultry in Brazil

Three hundred and fifty strains of E. coli isolated from septicemic poultry from seven states of Brazil were examined for presence of nine adhesion-encoding genes, hemagglutination and adherence to chicken tracheal cells (in vitro). Analysis of the strains by colony hybridization tests demonstrated that 93.7 percent of the isolates were fim +, 17 percent pap+ and 5.7 percent were sfa+. The mannose sensitive fimbriae occur with similar frequency in APEC isolated from all Brazilians states, while significant differences among pap and sfa genes distributions were observed. The results showed that 0.85 percent and 0.28 percent of APEC were positive for genes that encoded enteroaggregative adhesins and EPEC adherence factor, respectively. None of APEC was positive for DA, afa, Bfp and Eae probes. The adherence to chicken tracheal cells showed 96 percent positive strains, while hemagglutination assays showed 26.5 percent of the isolates were mannose sensitive and 21.7 percent were mannose resistant.

Trezentas e cinqüenta amostras de E. coli isoladas de aves com septicemia em sete estados do Brasil foram examinadas para a presença de nove genes codificadores de adesinas, hemaglutinação e aderência em células da traquéia (in vitro). A análise das amostras pela hibridização de colônias demonstrou que 93,7 por cento dos isolados eram fim +, 17 por cento pap+ e 5,7 por cento eram sfa+. As fímbrias manose sensíveis apresentaram uma distribuição uniforme em todos os estados do Brasil. No entanto, diferenças significativas na distribuição dos genes pap e sfa foram observadas. Os resultados mostraram que 0,85 por cento e 0,28 por cento das APEC foram positivas para os genes que codificam as adesinas enteroagregativas e o fator de aderência de EPEC, respectivamente. Nenhuma amostra foi positiva para as sondas DA, afa, Bfp e Eae. A aderência em células de traquéia de aves revelou 96 por cento de amostras positivas, enquanto os testes de hemaglutinação mostraram 26,5 por cento dos isolados mannose sensíveis e 21,7 por cento manose resistentes.

Distribution of virulence genes sefC, pefA and spvC in Salmonella Enteritidis phage type 4 strains isolated in Brazil

A distribuição dos genes de virulência sefC, pefA e spvC foi investigada em 110 amostras de Salmonella Enteritidis pertencentes ao fagotipo 4 através da reação em cadeia da polimerase. A influência destes genes na colonização do ceco e invasão do fígado e baço em pintinhos de um dia de idade foi avaliada. Oito amostras foram negativas para o gene spvC, três para o gene pefA e uma amostra para o gene sefC. Estes resultados permitiram a classificação das amostras em quatro genótipos. A presença destes genes não influenciou a invasão da bactéria no fígado e baço das aves dez dias após a infecção, entretanto, a presença de mais de um gene fimbrial pode ter relação com a colonização cecal.

Comparison of experimental competitive-exclusion cultures for controlling Salmonella colonization in broiler chicks

Esse estudo avaliou a eficácia de três diferentes tipos de culturas de exclusão competitiva (EC-A, EC-B e EC-C) contra Salmonella Kedougou (SK), amostra NCTC 12173, resistente ao ácido Nalidíxico (NalR), em pintos de um dia de idade, utilizando-se 4 tratamentos, em três repeticões. A média logarítmica de Salmonella por gramas de fezes foi de 0,41 para o grupo tratado com a EC-A, contendo uma mistura de culturas bacterianas aeróbias e anaeróbias, derivada de conteúdo cecal de uma ave adulta; 1,22 no grupo tratado com a EC-B, contendo culturas bacterianas aeróbias; 1,00 no grupo tratado com a EC-C, contendo culturas bacterianas anaeróbias e 6,64 no grupo controle positivo. A porcentagem de aves colonizadas variou de 10 a 23,33 per center nos grupos tratados e foi de 63,33 per center no grupo controle. Uma boa protecão (76,66 a 90 per center) foi obtida em todos os tratamentos, sendo que a menor protecão foi verificada com os produtos experimentais contendo somente culturas de bactérias aeróbias ou anaeróbias. Os resultados sugerem que o uso de misturas de culturas aeróbias e anaeróbias pode ser efetivo para o uso na exclusão competitiva contra SK em frangos de corte.

Identification of Lactobacillus spp. from broiler litter in Brazil

Foram identificadas cepas de Lactobacillus spp. de 100 amostras de camas de frango coletadas de diferentes regiões de producão avícola do Brasil. Foram isoladas dez espécies diferentes de Lactobacillus: L. plantarum, L. casei subsp. pseudoplantarum, L. delbrueckii subsp. delbrueckii, L. reuteri, L. murinus, L. agilis, L.delbrueckii subsp. lactis, L. salivarus subsp. salicinus, L. viridenscens, L. amylophilus.

Lethal factor to mice produced by Escherichia coli isolated from chickens with swollen head syndrome.

A lethal toxin similar to Bacillus cererus lethal toxin was detected in the culture supernatants of Escherichia coli isolated from chickens with swollen head syndrome. The lethal activity was heat-labile, protease-sensitive and killed mice within 10 min. The light microscopy of the histopathological studies revealed that the principal organ affected by this toxin was the lung but the liver and kidneys also showed lesions. The relevance of this lethal activity from E. coli remains to be determined.

Glycopeptides susceptibility among enterococci isolated from a poultry farm in São Paulo, Brazil (1996/1997)

Entrococci resistance to glycopeptides was evaluated in Brazilian poultry feed with feed supplemented with avoparcin as growth promoter. The susceptibility to the glycopeptides avoparcin, teicoplanin and vancomycin was determined for 217 enterococci isolated from cloacal swabes (one swab per bird) in tests and controls groups. Tests group comprised three groups (A, B and C) of Hubbard broiler-chickens 14, 21 and 35 days old, respectively. These birds were from one single farm, with a common feed source supplemented with avoparcin (10 mg/kg of feed). Controls groups (1 and 2) comprised 25 and 42 days old broilers, respectively, obtained from the faculty of Veterinary Medicine's aviary (University of São Paulo) where avoparcin was never used. No glycopeptide resistant enterococci strain was found, but and increase of Enterococcus faecium in faeces of chickens fed with avoparcin, independent of the age of the bird, was detected.

Isolamento de yersinia pseudotuberculosis de bezerros, na regiäo de Londrina, Paraná, Brasil / Isolation of yersinia psudotuberculosis from calves, in Londrina, Paraná, Brazil

Säo relatados o isolamento, características bioquímicas e sensibilidade a drogas antimicrobianas de 3 cepas de Yersinia pseudotuberculosis pertencentes ao grupo O-III. As cepas foram isoladas de bezerros com diarréia, na regiäo de Londrina, Paraná, Brazil