Effects of feeding a multivalent polyclonal antibody preparation on feedlot performance, carcass characteristics, rumenitis, and blood gas profile in Bos indicus biotype yearling bulls

The objective of this study was to evaluate effects of feeding monensin (MON) or a multivalent polyclonal antibody preparation (PAP) against several rumen microorganisms on feedlot performance, carcass characteristics, blood gas profile, and rumenitis of Bos indicus biotype (BT) yearling bulls. The study was designed as a completely randomized design with a 3 x 2 factorial arrangement, replicated 4 times, in which 32 yearling bulls of each of 3 BT evaluated (3-way-cross, TC; Canchim, CC; and Nellore, NE) were fed diets containing either MON at 300 mg.d(-1) or PAP at 10 mL.d(-1) across 3 different periods. No significant (P > 0.10) feed additive (FA) main effects were observed for any of the feedlot performance variables and carcass characteristics with the exception of dressing percentage. Yearling bulls receiving PAP had a decreased (P = 0.047) dressing percentage when compared with yearling bulls receiving MON. Significant (P < 0.05) BT main effects were observed for all feedlot performance variables and carcass characteristics with the exception of kidney-pelvic fat expressed in kilograms (P = 0.49) and LM lipids content (P = 0.45). Crossbred yearling bulls (TC and CC) had greater (P < 0.001) ADG, DMI in kilograms, DMI as % of BW, and improved (P = 0.001) G: F when compared with NE yearling bulls. A tendency (P = 0.072) for a FA main effect was observed for rumenitis scores, in which yearling bulls receiving PAP had lesser rumenitis scores than those receiving MON. When the data were disposed as frequency percentage, 55.6% and 45.7% of the rumens from yearling bulls fed PAP and MON were scored between 0 and 1, respectively (0 = no lesions, 10 = severe lesions). Likewise, a significant BT main effect was observed (P = 0.008), where NE yearling bulls had greater rumenitis scores than those of crossbred yearling bulls (TC and CC). No signifi cant FA main effects were observed (P > 0.10) for any of the fatty acids measured in the subcutaneous adipose tissue, with the exception that yearling bulls receiving MON had greater (P < 0.05) concentrations of palmitic acid (16: 0), margaric acid (17: 0), docosapentaenoic acid (22: 5), and docosahexaenoic acid (22: 6) than those yearling bulls receiving PAP. Feeding PAP tended to decrease incidence of rumen lesions and led to similar feedlot performance compared with feeding MON. Thus, PAP is a new technology that presents a possible alternative for ionophores.

Infantile Encephaloneuromyopathy and Defective Mitochondrial Translation Are Due to a Homozygous RMND1 Mutation

Defects of mitochondrial protein synthesis are clinically and genetically heterogeneous. We previously described a male infant who was born to consanguineous parents and who presented with severe congenital encephalopathy, peripheral neuropathy, myopathy, and lactic acidosis associated with deficiencies of multiple mitochondrial respiratory-chain enzymes and defective mitochondrial translation. In this work, we have characterized four additional affected family members, performed homozygosity mapping, and identified a homozygous splicing mutation in the splice donor site of exon 2 (c.504+1G>A) of RMND1 (required for meiotic nuclear division-1) in the affected individuals. Fibroblasts from affected individuals expressed two aberrant transcripts and had decreased wild-type mRNA and deficiencies of mitochondrial respiratory-chain enzymes. The RMND1 mutation caused haploinsufficiency that was rescued by overexpression of the wild-type transcript in mutant fibroblasts; this overexpression increased the levels and activities of mitochondrial respiratory-chain proteins. Knockdown of RMND1 via shRNA recapitulated the biochemical defect of the mutant fibroblasts, further supporting a loss-of-function pathomechanism in this disease. RMND1 belongs to the sif2 family, an evolutionary conserved group of proteins that share the DUF155 domain, have unknown function, and have never been associated with human disease. We documented that the protein localizes to mitochondria in mammalian and yeast cells. Further studies are necessary for understanding the function of this protein in mitochondrial protein translation.

Distinct mechanisms underlie adaptation of proximal tubule Na+/H+ exchanger isoform 3 in response to chronic metabolic and respiratory acidosis

The Na+/H+ exchanger isoform 3 (NHE3) is essential for HCO3- reabsorption in renal proximal tubules. The expression and function of NHE3 must adapt to acid-base conditions. The goal of this study was to elucidate the mechanisms responsible for higher proton secretion in proximal tubules during acidosis and to evaluate whether there are differences between metabolic and respiratory acidosis with regard to NHE3 modulation and, if so, to identify the relevant parameters that may trigger these distinct adaptive responses. We achieved metabolic acidosis by lowering HCO3- concentration in the cell culture medium and respiratory acidosis by increasing CO2 tension in the incubator chamber. We found that cell-surface NHE3 expression was increased in response to both forms of acidosis. Mild (pH 7.21 +/- 0.02) and severe (6.95 +/- 0.07) metabolic acidosis increased mRNA levels, at least in part due to up-regulation of transcription, whilst mild (7.11 +/- 0.03) and severe (6.86 +/- 0.01) respiratory acidosis did not up-regulate NHE3 expression. Analyses of the Nhe3 promoter region suggested that the regulatory elements sensitive to metabolic acidosis are located between -466 and -153 bp, where two consensus binding sites for SP1, a transcription factor up-regulated in metabolic acidosis, were localised. We conclude that metabolic acidosis induces Nhe3 promoter activation, which results in higher mRNA and total protein level. At the plasma membrane surface, NHE3 expression was increased in metabolic and respiratory acidosis alike, suggesting that low pH is responsible for NHE3 displacement to the cell surface.

In vitro and in vivo evaluation of the biocompatibility of a calcium phosphate/poly(lactic-co-glycolic acid) composite

This study assess the effects of bioceramic and poly(lactic-co-glycolic acid) composite (BCP/PLGA) on the viability of cultured macrophages and human dental pulp fibroblasts, and we sought to elucidate the temporal profile of the reaction of pulp capping with a composite of bioceramic of calcium phosphate and biodegradable polymer in the progression of delayed dentine bridge after (30 and 60 days) in vivo. Histological evaluation of inflammatory infiltrate and dentin bridge formation were performed after 30 and 60 days. There was similar progressive fibroblast growth in all groups and the macrophages showed viability. The in vivo study showed that of the three experimental groups: BCP/PLGA composite, BCP and calcium hydroxide (Ca(OH)(2)) dentin bridging was the most prevalent (90 %) in the BCP/PLGA composite after 30 days, mild to moderate inflammatory response was present throughout the pulp after 30 days. After 60 days was observed dentine bridging in 60 % and necrosis in 40 %, in both groups. The results indicate that understanding BCP/PLGA composite is biocompatible and by the best tissue response as compared to calcium hydroxide in direct pulp capping may be important in the mechanism of delayed dentine bridge after 30 and 60 days.

Gas-producing and spoilage potential of Enterobacteriaceae and lactic acid bacteria isolated from chilled vacuum-packaged beef

This study aimed to enumerate and identify lactic acid bacteria and Enterobacteriaceae from spoiled and nonspoiled chilled vacuum-packaged beef and determine their potential to cause blown pack spoilage. These microbial groups were also enumerated in nonspoiled samples and detected in abattoir samples. The potential of isolates to cause blown pack spoilage of vacuum-packaged beef stored at chilled temperature (4 degrees C) and abuse temperature (15 degrees C) was investigated. Populations of lactic acid bacteria in exudate of spoiled and nonspoiled samples were not significantly different (P > 0.05), whereas the number of lactic acid bacteria on the surface was significantly higher (P < 0.05) in spoiled samples as compared to nonspoiled samples. The population of Enterobacteriaceae species in exudate and on the surface of samples were significantly higher (P < 0.05) in spoiled packs in comparison with nonspoiled packs. Results of the deterioration potential showed that blown pack spoilage was noticeable after 7 days at 15 degrees C and after 6 weeks at 4 degrees C for samples inoculated with Hafnia alvei.

Intravenous Hypertonic Saline Solution (7.5%) and Oral Electrolytes to Treat of Calves with Noninfectious Diarrhea and Metabolic Acidosis

Objective The aim of this study was to compare the efficacy of treating osmotic diarrhea and dehydration in calves with hypertonic saline solution (HSS) IV, isotonic electrolyte solution (IES) PO, and a combination of these 2 solutions (HSS + IES). Experimental Design Eighteen male calves 830 days of age were used to evaluate the efficacy of 3 methods of fluid therapy after induction of osmotic diarrhea and dehydration. The diarrhea and dehydration were induced by administration of saccharose, spironolactone, and hydrochlorothiazide for 48 hours. The animals were randomly divided into 3 experimental groups: Group 1: 7.2% hypertonic saline solution-HSS (5 mL/kg IV); Group 2: oral isotonic electrolyte solution IES (60 mL/kg PO); or Group 3: HSS+IES. Clinical signs and laboratory finding observed 48 hours post-induction (Time 0) included diarrhea, dehydration, lethargy, and metabolic acidosis. Results Calves treated with HSS + IES experienced decreases in hematocrit, total protein concentration, albumin concentration, urea nitrogen concentration, and plasma volume as well as increases in blood pH, blood bicarbonate concentration, and central venous pressure between 1 and 3 hours post-treatment. These findings also were observed in animals treated with IES, however, at a slower rate than in the HSS + IES-treated animals. Animals treated with HSS continued to display signs of dehydration, lethargy, and metabolic acidosis 24 hours post-treatment. Conclusion Treatment with a combination of HSS and IES produced rapid and sustainable correction of hypovolemia and metabolic acidosis in calves with noninfections diarrhea and dehydration.

Multi-Walled Carbon Nanotubes and Poly(lactic acid) Nanocomposite Fibrous Membranes Prepared by Solution Blow Spinning

Nanocomposite fibers based on multi-walled carbon nanotubes (MWCNT) and poly(lactic acid) (PLA) were prepared by solution blow spinning (SBS). Fiber morphology was characterized by scanning electron microscopy (SEM) and optical microscopy (OM). Electrical, thermal, surface and crystalline properties of the spun fibers were evaluated, respectively, by conductivity measurements (4-point probe), thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), contact angle and X-ray diffraction (XRD). OM analysis of the spun mats showed a poor dispersion of MWCNT in the matrix, however dispersion in solution was increased during spinning where droplets of PLA in solution loaded with MWCNT were pulled by the pressure drop at the nozzle, producing PLA fibers filled with MWCNT. Good electrical conductivity and hydrophobicity can be achieved at low carbon nanotube contents. When only 1 wt% MWCNT was added to low-crystalline PLA, surface conductivity of the composites increased from 5 x 10(-8) to 0.46 S/cm. Addition of MWCNT can slightly influence the degree of crystallinity of PLA fibers as studied by XRD and DSC. Thermogravimetric analyses showed that MWCNT loading can decrease the onset degradation temperature of the composites which was attributed to the catalytic effect of metallic residues in MWCNT. Moreover, it was demonstrated that hydrophilicity slightly increased with an increase in MWCNT content. These results show that solution blow spinning can also be used to produce nanocomposite fibers with many potential applications such as in sensors and biosensors.

Acid-base and biochemical stabilization and quality of recovery in male cats with urethral obstruction and anesthetized with propofol or a combination of ketamine and diazepam

This study compared acid-base and biochemical changes and quality of recovery in male cats with experimentally induced urethral obstruction and anesthetized with either propofol or a combination of ketamine and diazepam for urethral catheterization. Ten male cats with urethral obstruction were enrolled for urethral catheterization and anesthetized with either ketamine-diazepam (KD) or propofol (P). Lactated Ringer's solution was administered by intravenous (IV) beginning 15 min before and continuing for 48 h after relief of urethral obstruction. Quality of recovery and time to standing were evaluated. The urethral catheter was maintained to measure urinary output. Hematocrit (Hct), total plasma protein (TPP), albumin, total protein (TP), blood urea nitrogen (BUN), creatinine, pH, bicarbonate (HCO3-), chloride, base excess, anion gap, sodium, potassium, and partial pressure of carbon dioxide in mixed venous blood (pvCO(2)) were measured before urethral obstruction, at start of fluid therapy (0 h), and at subsequent intervals. The quality of recovery and time to standing were respectively 4 and 75 min in the KD group and 5 and 16 min in the P group. The blood urea nitrogen values were increased at 0, 2, and 8 h in both groups. Serum creatinine increased at 0 and 2 h in cats administered KD and at 0, 2, and 8 h in cats receiving P, although the values were above the reference range in both groups until 8 h. Acidosis occurred for up to 2 h in both groups. Acid-base and biochemical stabilization were similar in cats anesthetized with propofol or with ketamine-diazepam. Cats that received propofol recovered much faster, but the ketamine-diazepam combination was shown to be more advantageous when treating uncooperative cats as it can be administered by intramuscular (IM) injection.

Growth potential of Salmonella spp. and Listeria monocytogenes in nine types of ready-to-eat vegetables stored at variable temperature conditions during shelf-life

Growth potential (delta) is defined as the difference between the population of a microorganism at the end of shelf-life of specific food and its initial population. The determination of 6 of Salmonella and Listeria monocytogenes in RTE vegetables can be very useful to determine likely threats to food safety. However, little is known on the behavior of these microorganisms in several RTE vegetables. Therefore, the aim of this study was to determine the delta of both pathogens in nine different types of RTE vegetables (escarole, collard green, spinach, watercress, arugula, grated carrot, green salad, and mix for yakisoba) stored at refrigeration (7 degrees C) and abuse temperature (15 degrees C). The population of aerobic microorganisms and lactic acid bacteria, including those showing antimicrobial activity has been also determined. Results indicated that L monocytogenes was able to grow (delta >= 0.5 log(10)) in more storage conditions and vegetables than Salmonella. Both microorganisms were inhibited in carrots, although a more pronounced effect has been observed against L monocytogenes. The highest 5 values were obtained when the RTE vegetables were stored 15 degrees C/6 days in collard greens (delta=3.3) and arugula (delta=3.2) (L monocytogenes) and arugula (delta=4.1) and escarole (delta=2.8) (Salmonella). In most vegetables and storage conditions studied, the counts of total aerobic microorganisms raised significantly independent of the temperature of storage (p<0.05). Counts of lactic acid bacteria were higher in vegetables partially or fully stored at abuse temperature with recovery of isolates showing antimicrobial activity. In conclusion, the results of this study show that Salmonella and L monocytogenes may grow and reach high populations in RTE vegetables depending on storage conditions and the definition of effective intervention strategies are needed to control their growth in these products. (C) 2012 Elsevier B.V. All rights reserved.

Growth, organic acids profile and sugar metabolism of Bifidobacterium lactis in co-culture with Streptococcus thermophilus: the inulin effect

The organic acids profile, sugar metabolism and biomass growth of Streptococcus thermophilus (St) and Bifidobacterium lactis (BI) have been studied in pure cultures or binary co-culture (St-BI) in skim milk either containing 40 mg/g of inulin or not. With inulin, the time required by St. BI and St-BI to complete fermentation (i.e., when the pH reached 4.5) was about 14, 8 and 49% shorter than without inulin, respectively. This prebiotic also enhanced the levels of lactic and acetic acids and volatile compounds, showing a positive synbiotic effect between pre- and probiotics. In particular, the St-BI co-culture showed final concentrations of both microorganisms about 15 and 38% higher than in their respective pure cultures, thus highlighting a clear synergistic effect between these microorganisms due to mutual interactions. In addition, the well-known bifidogenic effect of inulin was confirmed. (c) 2012 Elsevier Ltd. All rights reserved.

A clinical and hemogasometric survey of neonatal lambs

In order to provide adequate medical assistance to neonates, the extent of vitality impairment has to be investigated through complementary exams, as well as clinical assessment. This investigation aimed to identify the physiological changes that occur during neonatal adaptation and to develop a clinical approach that can be performed during the first hour of life in neonatal lambs born through vaginal eutocic labor. The neonatal vitality of 14 Santa Ines lambs was verified using the Apgar system and rectal temperature at birth and after 5 and 60 min after birth. From the total number of neonates, 7 lambs were randomly selected for blood gas analysis and glucose immediately at birth and 1 h after birth. The lambs had hypoglycemia immediately after birth, as well as acidosis due to metabolic and respiratory causes. Given their hypoxemia at birth, lambs immediately exhibit tachycardia and tachypnea. However, neonatal lambs reached Apgar score superior than 7 after 5 min of birth. Ovine neonates are relatively mature at birth, with adequate thermoregulation and active mechanisms to compensate for physiological acid-base imbalances. In conclusion, a systematic clinical examination of newborn sheep should include the implementation of the Apgar score coupled with the confirmation of any acid-base imbalances. Further research should evaluate neonatal adaptation to this critical period over a longer period of time. (C) 2012 Elsevier B.V. All rights reserved.

Resistência de bactérias ácido-láticas a bacteriófagos provenientes de unidades de processamento de queijo Coalho

Este trabalho teve como objetivos isolar bacteriófagos de amostras de leite, soro e queijo de Coalho e avaliar a resistência de cepas de Lactobacillus paracasei, pertencentes à Coleção de Micro-organismos de Interesse para a Agroindústria Tropical da Embrapa Agroindústria Tropical, aos fagos isolados. Posteriormente, a resistência destas cepas a fagos específicos para L. paracasei, da Coleção do Instituto de Lactología Industrial - INLAIN (Santa Fe, Argentina), também foi avaliada. As amostras para isolamento dos fagos foram obtidas em quatro unidades de processamento de queijo de Coalho, sendo duas artesanais e duas industriais, localizadas no Estado do Ceará. Para o isolamento dos bacteriófagos, foi empregado o teste de lise celular (spot), enquanto que a resistência das culturas aos fagos foi avaliada pelos testes de capacidade de produção de ácido e avaliação da turbidez. As cepas avaliadas foram resistentes aos bacteriófagos provenientes das unidades de processamento de queijo de Coalho e aos bacteriófagos da Coleção do INLAIN. Os resultados obtidos indicaram que as culturas láticas testadas, resistentes aos bacteriófagos, podem ser utilizadas na composição de fermento lático destinado à elaboração de queijo de Coalho, a partir de leite pasteurizado.

Bacteriocinogenic and virulence potential of Enterococcus isolates obtained from raw milk and cheese

Aims To provide molecular and phenotypical characterization of Enterococcus isolates obtained from raw milk and cheese, regarding their bacteriocinogenic and virulence activity. Methods and Results Forty-three bacteriocinogenic enterococci isolates were identified by 16s rDNA, fingerprinted by RAPD-PCR analysis and tested by PCR for the presence of genes for lantibiotics (lanM, lanB and lanC) and enterocins (entA, entB, entP, entL50AB and entAS48) and by phenotypical methods for bacteriocin production and inhibitory spectrum. Also, the virulence of the isolates was evaluated by PCR for genes gelE, hyl, asa1, esp, cylA, efaA, ace, vanA, vanB, hdc1, hdc2, tdc and odc and by phenotypical tests for gelatinase, lipase, DNAse and a- and beta-haemolysis. Most isolates (93.0%) harboured at least one lantibiotic or enterocin gene and were positive for several tested virulence genes, mainly asa1 (100%), gelE (93.0%) and efaA (83.7%). 53.5% of the isolates presented beta-haemolysis. Conclusions Enterococcus spp. isolates presented an interesting potential application for food preservation because of bacteriocin production; however, virulence-related genes were identified in all RAPD profiles. Significance and Impact of the Study The study demonstrated the contradictory characteristics of the tested Enterococcus isolates: they presented a good potential for application in food biopreservation but contained several virulence factors.

Enterococcus faecium isolated from Lombo, a Portuguese traditional meat product: characterisation of antibacterial compounds and factors affecting bacteriocin production

Strain ST211CH, identified as a strain of Enterococcus faecium, isolated from Lombo produced a bacteriocin that inhibited the growth of Enterococcus spp., Listeria spp., Klebsiella spp., Lactobacillus spp., Pseudomonas spp., Staphylococcus spp. and Streptococcus spp. The mode of action of the bacteriocin named as bacteriocin ST211Ch was bactericidal against Enterococcus faecalis ATCC19443. As determined by Tricine-SDS-PAGE, the approximate molecular mass of the bacteriocin was 8.0 kDa. Loss in antimicrobial activity was recorded after treatment with proteolytic enzymes. Maximum activity of bacteriocin ST211Ch was measured in broth cultures of E. faecium strain ST211Ch after 24 h; thereafter, the activity was reduced. Bacteriocin ST211Ch remained active after exposure to various temperatures and pHs, as well as to Triton X-100, Tween-80, Tween-20, sodium dodecyl sulfate, NaCl, urea and EDTA. Effect of media components on production of bacteriocin ST211Ch was also studied. On the basis of PCR reactions targeting different bacteriocin genes, i.e. enterocins, curvacins and sakacins, no evidences for the presence of these genes in the total DNA of E. faecium strain ST211Ch was obtained. The bacterium most probably produced a bacteriocin different from those mentioned above. Based on the antimicrobial spectrum, stability and mode of action of bacteriocin ST211CH, E. faecium strain ST211Ch might be considered as a potential candidate with beneficial properties for use in biopreservation to control food spoilage bacteria.

Sardinian goat's milk as source of bacteriocinogenic potential protective cultures

Goat breeding in Sardinia constitutes an important source of income for farming and shepherding activities. In this study 170 LAB strains were isolated from Sardinian goat's milk and tested for bacteriocins production against several food-borne pathogenic microorganisms. Four isolates (SD1, SD2, SD3 and SD4) were selected for their effective inhibition on Listeria monocytogenes. The strains were classified as members of Enterococcus genus, according to their biochemical and physiological characteristics, and then genetically identified as Enterococcus faecium. In MRS broth at 37 degrees C, bacteriocins SD1 and SD2 were produced at much higher levels (51200 AU/ml) compared to bacteriocin SD3 (3200 AU/ml) and bacteriocin SD4 (800 AU/ml). Their peptides were inactivated by proteolytic enzymes, but not when treated with alpha-amylase, catalase and lipase. The four bacteriocins remained stable at pH from 2.0 to 12.0, after exposure to 100 degrees C for 120 min and were not affected by the presence of surfactants and salts (N-Laourylsarcosine, NaCl, SDS, Triton X-100, Tween 20, Tween 80 and urea). Their molecular size was determined to be approximately 5 kDa by tricine-SDS-PAGE. Since the strains exhibited a strong antimicrobial activity against 21 L monocytogenes strains and 6 Salmonella spp. isolates, they should be considered as potential bio-preservatives cultures for fermented food productions. Moreover, due to their technological features, the four strains could be taken in account for using as adjunct NSLAB (non-starter lactic acid bacteria) rather than as starter culture. (C) 2011 Elsevier Ltd. All rights reserved.