Time-related action of Lactobacillus plantarum in the bacterial microbiota of shrimp digestive tract and its action as immunostimulant

The objective of this work was to assess the time-related action of probiotic Lactobacillus plantarum in the bacterial microbiota of the digestive tract of Litopenaeus vannamei, and the relation of total haemocyte count and serum phenol oxidase activity of shrimp challenged with Vibrio harveyi. Shrimps were fed with a probiotic-supplemented diet, for eight days, then shifted to a commercial diet. Shrimps fed only with the commercial diet served as control. Evaluations were made on the 8th day of experiment and repeated two, four, six and eight days later. Total lactic bacteria in the digestive tract was higher until the 4th day of evaluation in the probiotic-supplemented group. Vibrio spp. counts were higher in the control at days zero and two. Until the 4th day of evaluation, the total haemocyte counts in shrimps after challenge with V. harveyi were higher in probiotic-supplemented group than in control group. Significant difference was not observed in phenol oxidase activity. On the 6th day after shifting from supplemented to control diet, all parameters were equal in both groups, suggesting that the time-related action of L. plantarum in shrimp is short.

In vitro selection of bacteria with potential for use as probiotics in marine shrimp culture

The objective of this work was to isolate strains of lactic acid bacteria with probiotic potential from the digestive tract of marine shrimp (Litopenaeus vannamei), and to carry out in vitro selection based on multiple characters. The ideotype (ideal proposed strain) was defined by the highest averages for the traits maximum growth velocity, final count of viable cells, and inhibition halo against nine freshwater and marine pathogens, and by the lowest averages for the traits duplication time and resistance of strains to NaCl (1.5 and 3%), pH (6, 8, and 9), and biliary salts (5%). Mahalanobis distance (D²) was estimated among the evaluated strains, and the best ones were those with the shortest distances to the ideotype. Ten bacterial strains were isolated and biochemically identified as Lactobacillus plantarum (3), L. brevis (3), Weissella confusa (2), Lactococcus lactis (1), and L. delbrueckii (1). Lactobacillus plantarum strains showed a wide spectrum of action and the largest inhibition halos against pathogens, both Gram-positive and negative, high growth rate, and tolerance to all evaluated parameters. In relation to ideotype, L. plantarum showed the lowest Mahalanobis (D²) distance, followed by the strains of W. confusa, L. brevis, L. lactis, and L. delbrueckii. Among the analyzed bacterial strains, those of Lactobacillus plantarum have the greatest potential for use as a probiotic for marine shrimp.

Detecção de adulterações em produtos alimentares contendo leite e/ou proteínas lácteas

A critical review of the most relevant analytical methodologies for quality and authenticity control of dairy products and foods containing milk proteins is presented. Chromatographic, electrophoretic and immunological methods are used for: detection of cow's milk in ewe and goat milks, detection of whey added to milk, detection of caseins and/or whey proteins in non-lactic foods and study compounds resulting from milk proteins degradation. Techniques based on polimerase chain reaction are also suitable for detection of cow's milk on cheeses of ewe and goat milks.

Otimização e validação de método para determinação de ácidos orgânicos em vinhos por cromatografia líquida de alta eficiência

The organic acids (tartaric, malic, citric, lactic and succinic) are de main components responsible for the acidity in the wine. This method for simultaneous determination of organic acids and interfering peaks in wines can be achieved in 16 min. The sample preceded by a dilution and filtration step. The chromatographic separation required one reversed phase column, isocratic mobile phase (acetonitrila, formic acid in water) and detection wavelength was set at 212 nm. The validation confirmed good repeatability, recovery and application in red and white wines.

CARACTERIZAÇÃO E AVALIAÇÃO IN VITRO DE NANOCOMPÓSITOS DE POLI (L-ÁCIDO LÁTICO) E NANOTUBOS DE CARBONO DE PAREDES MÚLTIPLAS PURIFICADOS

Carbon nanotubes (CNT) have been studied for biomedical applications due to their unique properties. However, pristine CNT have structural features and impurities that can cause toxicity to biological systems. In this work, we describe a method to purify multiwalled carbon nanotubes (MWCNT) by chemical modification and subsequent attachment of hydroxyl and carboxyl groups to improve dispersion and to decrease toxic effects. Nanocomposites from poly (L-lactic acid) (PLLA) and nanotubes were produced by the solvent casting method and characterized and evaluated for cytocompatibility with Vero cells. The nanocomposite interactions with Vero cells demonstrated that the cells were able to adhere and sustain proliferation and showed favorable cytocompatibility. In vitro studies also revealed an increase in fibroblast cell viability in the nanocomposites, compared with neat PLLA.

Physical-chemical characterization and wet milling yield of four maize hybrids

The influence of physical-chemical characteristics of maize grains and lactic acid concentrations on byproduct yields, generated by conventional wet milling, was studied during steeping, for four maize hybrids and two lactic acid concentrations (0.55 and 1.00%). For physical-chemical characterization, grain dimensions (length, thickness, and width) were determined, as well as mass of 100 grains, percentage of floating grains, volumetric mass, and centesimal composition. Statistical differences were found for percentage of floating grains (2.33 to 24.67%), volumetric mass (0.814 to 0.850 kg.L-1), mass of 100 grains (0.033 to 0.037 kg), water content (11.86 to 12.20%), proteins (8.21 to 9.06%), lipids (3.00 to 4.77%), and ashes (1.07 to 1.26%). There were no relationships of wet milling yields with maize appearance and physical-chemical characteristics. The addition of 1.00% lactic acid did not statistically improve byproduct yields; however, it favored separation of the grain components.

Cirurgia para controle do dano: uma revisão

Damage control surgery is one of the major advances in surgical practice in the last 20 years. The indications for damage control surgery are: the need to terminate a laparotomy rapidly in an exsanguinating, hypothermic patient who had developed a coagulopathy and who is about to die on the operating table; inability to control bleeding by direct hemostasis; and inability to close the abdomen without tension because of massive visceral edema and a tense abdominal wall. Damage control surgery has three phases: 1) laparotomy to control hemorrhage by packing, shunting, or balloon tamponade, or both; control of intestinal spillage by resection or ligation of damaged bowel, or both; 2) physiological resuscitation to correct hypothermia, metabolic acidosis, and coagulopathy. 3) planned reoperation for definitive repair. Damage control surgery is appropriate in a small number of critically ill patients who are likely to require substantial hospital resources. However, there are many questions that need to be answered. Who is the patient elected for this surgery? When is the ideal time to make the decision? Which are the parameters that indicate to the surgeons the moment to re-operate the patient? How to treat the long-term complications? In the present review we described some historical aspects, indications, technical aspects, advantages and disadvantages of this procedure, as well as its physiological consequences and morbidity and mortality rates of damage control surgery. Damage control surgery offers a simple effective alternative to the traditional surgical management of complex or multiple injuries in critically injured patients.

Health management practices and disease prevalence in dairy sheep systems in Argentina

A cross-sectional survey of 19 dairy sheep farms in Argentina was carried out with the purpose to know farm management, health practices, and occurrence and mortality of diseases. The survey comprised 40% of all sheep milking farms in Argentina. A questionnaire was conducted by way of personal interviews with sheep owners during farm visits. The proportions of farms reporting routine vaccination for clostridial diseases, contagious ecthyma, pneumonia and mineral and vitamin parenteral administration were 63%, 47.3%, 16.6% and 42.1% respectively. Regular treatment against lice was used in 37.5% of the farms, and 89.5% o the farmers treated against gastrointestinal nematodes (GIN). The mean number of GIN drenches per farm was 2.26±1.78 annually. In 68.4% of the milking flocks the California Mastitis Test was regularly done and 55.6% of the farmer managers had sampled their flocks once a year for Brucella ovis antibodies. During the pre-mating period respectively 68.4% and 50% of farmers clinically examined their rams and ewe for general health and teeth condition. The udders of ewes were frequently inspected at the start of each milking period. The most important parasite problems noticed were GIN (reported by 57.9% of farmers), lice (57.9%) and scabies (10.5%) and the most frequent infectious diseases were ecthyma (73.7%), pneumonia and other respiratory problems (57.9%), clinical mastitis (55.6%), clostridial diseases (36.9%) and foot lameness (35.2%). Photosensitivity (47.4%) and ruminal acidosis (42.1%) were reported as other frequent toxic or metabolic disorders. Owners mentioned that the mean lifespan or milk productive time per ewe was 4.5±1.4 years. Perinatal lamb mortality was 8.5% and the total flock mortality rates, above the first 24 h of life was 6.9%. The high rates of lamb mortality during the pre-weaning (10.3%) and post-weaning (5.9%) periods indicate that this problem, as well as the most prevalent diseases, should be the subject of further studies.

Serum intact parathyroid hormone levels in cats with chronic kidney disease

Chronic kidney disease (CKD) is frequently observed in cats and it is characterized as a multisystemic illness, caused by several underlying metabolic changes, and secondary renal hyperparathyroidism (SRHPT) is relatively common; usually it is associated with the progression of renal disease and poor prognosis. This study aimed at determining the frequency of SRHPT, and discussing possible mechanisms that could contribute to the development of SRHPT in cats at different stages of CKD through the evaluation of calcium and phosphorus metabolism, as well as acid-base status. Forty owned cats with CKD were included and divided into three groups, according to the stages of the disease, classified according to the International Renal Interest Society (IRIS) as Stage II (n=12), Stage III (n=22) and Stage IV (n=6). Control group was composed of 21 clinically healthy cats. Increased serum intact parathyroid hormone (iPTH) concentrations were observed in most CKD cats in all stages, and mainly in Stage IV, which hyperphosphatemia and ionized hypocalcemia were detected and associated to the cause for the development of SRHPT. In Stages II and III, however, ionized hypercalcemia was noticed suggesting that the development of SRHPT might be associated with other factors, and metabolic acidosis could be involved to the increase of serum ionized calcium. Therefore, causes for the development of SRHPT seem to be multifactorial and they must be further investigated, mainly in the early stages of CKD in cats, as hyperphosphatemia and ionized hypocalcemia could not be the only factors involved.

Lactated Ringer's solution or 0.9% sodium chloride as fluid therapy in pigeons (Columba livia) submitted to humerus osteosynthesis

The study aimed to compare the effects of intraosseous infusion of lactated Ringer's and 0.9% sodium chloride solutions on the electrolytes and acid-base balance in pigeons submitted to humerus osteosynthesis. Eighteen pigeons were undergoing to isoflurane anesthesia by an avalvular circuit system. They were randomly assigned into two groups (n=9) receiving lactated Ringer's solution (LR) or 0.9% sodium chloride (SC), in a continuous infusion rate of 20mL/kg/h, by using an intraosseous catheter into the tibiotarsus during 60-minute anesthetic procedure. Heart rate (HR), and respiratory rate (RR) were measured every 10 min. Venous blood samples were collected at 0, 30 and 60 minutes to analyze blood pH, PvCO2, HCO3 -, Na+ and K+. Blood gases and electrolytes showed respiratory acidosis in both groups during induction, under physical restraint. This acidosis was evidenced by a decrease of pH since 0 min, associated with a compensatory response, observed by increasing of HCO3 - concentration, at 30 and 60 min. It was not observed any changes on Na+ and K+ serum concentrations. According to the results, there is no reason for choosing one of the two solutions, and it could be concluded that both fluid therapy solutions do not promote any impact on acid-base balance and electrolyte concentrations in pigeons submitted to humerus osteosynthesis.

Effect of Lactobacillus sp. isolates supernatant on Escherichia coli O157:H7 enhances the role of organic acids production as a factor for pathogen control

Many attempts have been made to establish the control of foodborne pathogens through Lactobacillus isolates and their metabolism products with success being obtained in several situations. The aim of this study was to investigate the antagonistic effect of eight Lactobacillusisolates, including L. caseisubsp. pseudoplantarum,L. plantarum, L. reuteri and L. delbrueckii subsp. delbrueckii, on the pathogenic Escherichia colistrain O157:H7. The inhibitory effect of pure cultures and two pooled cultures supernatants of Lactobacillus on the growth of pathogenic bacteria was evaluated by the spot agar method and by monitoring turbidity. Antimicrobial activity was confirmed for L. reuteri and L. delbrueckii subsp. delbrueckii and for a pool of lactic acid bacteria. The neutralized supernatant of the pool exerted a higher antimicrobial activity than that of the individual strains. Furthermore, D-lactic acid and acetic acid were produced during growth of the Lactobacillus isolates studied.

Monoassociation with Lactobacillus acidophilus UFV-H2b20 stimulates the immune defense mechanisms of germfree mice

Probiotics are formulations containing live microorganisms or microbial stimulants that have some beneficial influence on the maintenance of a balanced intestinal microbiota and on the resistance to infections. The search for probiotics to be used in prevention or treatment of enteric infections, as an alternative to antibiotic therapy, has gained significant impulse in the last few years. Several studies have demonstrated the beneficial effects of lactic acid bacteria in controlling infection by intestinal pathogens and in boosting the host's nonspecific immune response. Here, we studied the use of Lactobacillus acidophilus UFV-H2b20, a lactic acid bacterium isolated from a human newborn from Viçosa, Minas Gerais, Brazil, as a probiotic. A suspension containing 108 cells of Lactobacillus acidophilus UFV-H2b20 was inoculated into groups of at least five conventional and germfree Swiss mice to determine its capacity to stimulate the host mononuclear phagocytic activity. We demonstrate that this strain can survive the stressing conditions of the intestinal tract in vivo. Moreover, the monoassociation of germfree mice with this strain for seven days improved the host's macrophage phagocytic capacity, as demonstrated by the clearance of a Gram-negative bacterium inoculated intravenously. Monoassociated mice showed an undetectable number of circulating E. coli, while 0.1% of the original inoculum was still present in germfree animals. Mice treated with viable or heat-killed Lactobacillus acidophilus UFV-H2b20 presented similarly improved clearance capacity when compared with germfree controls. In addition, monoassociated mice had twice the amount of Kupffer cells, which are responsible for the clearance of circulating bacteria, compared to germfree controls. These results suggest that the L. acidophilus strain used here stimulates a nonspecific immune response and is a strong candidate to be used as a probiotic.

Heterologous protein secretion in Lactococcus lactis: a novel antigen delivery system

Lactic acid bacteria (LAB) are Gram-positive bacteria and are generally regarded as safe (GRAS) organisms. Therefore, LAB could be used for heterologous protein secretion and they are good potential candidates as antigen delivery vehicles. To develop such live vaccines, a better control of protein secretion is required. We developed an efficient secretion system in the model LAB, Lactococcus lactis. Staphylococcal nuclease (Nuc) was used as the reporter protein. We first observed that the quantity of secreted Nuc correlated with the copy number of the cloning vector. The nuc gene was cloned on a high-copy number cloning vector and no perturbation of the metabolism of the secreting strain was observed. Replacement of nuc native promoter by a strong lactococcal one led to a significant increase of nuc expression. Secretion efficiency (SE) of Nuc in L. lactis was low, i.e., only 60% of the synthesized Nuc was secreted. Insertion of a synthetic propeptide between the signal peptide and the mature moiety of Nuc increased the SE of Nuc. On the basis of these results, we developed a secretion system and we applied it to the construction of an L. lactis strain which secretes a bovine coronavirus (BCV) epitope-protein fusion (BCV-Nuc). BCV-Nuc was recognized by both anti-BCV and anti-Nuc antibodies. Secretion of this antigenic fusion is the first step towards the development of a novel antigen delivery system based on LAB-secreting strains.

Study of urinary acidification in patients with idiopathic hypocitraturia

Hypocitraturia (HCit) is one of the most remarkable features of renal tubular acidosis, but an acidification defect is not seen in the majority of hypocitraturic patients, whose disease is denoted idiopathic hypocitraturia. In order to assess the integrity of urinary acidification mechanisms in hypocitraturic idiopathic calcium stone formers, we studied two groups of patients, hypocitraturic (HCit, N = 21, 39.5 ± 11.5 years, 11 females and 10 males) and normocitraturic (NCit, N = 23, 40.2 ± 11.7 years, 16 females and 7 males) subjects, during a short ammonium chloride loading test lasting 8 h. During the baseline period HCit patients showed significantly higher levels of titratable acid (TA). After the administration of ammonium chloride, mean urinary pH (3rd to 8th hour) and TA and ammonium excretion did not differ significantly between groups. Conversely, during the first hour mean urinary pH was lower and TA and ammonium excretion was higher in HCit. The enhanced TA excretion by HCit during the baseline period and during the first hour suggests that the phosphate buffer mechanism is activated. The earlier response in ammonium excretion by HCit further supports other evidence that acidification mechanisms react promptly. The present results suggest that in the course of lithiasic disease, hypocitraturia coexists with subtle changes in the excretion of hydrogen ions in basal situations.

Acute and chronic effects of cadmium on blood homeostasis of an estuarine crab, Chasmagnathus granulata, and the modifying effect of salinity

Whole body oxygen consumption and some hemolymph parameters such as pH, partial pressure of gases, level of ions and lactate were measured in the estuarine crab Chasmagnathus granulata after both acute (96 h) and chronic (2 weeks) exposure to cadmium at concentrations ranging from 0.4 to 6.3 mg/l. In all instances, the crabs developed hemolymph acidosis, but no respiratory (increased PCO2) or lactate increases were evident. Hemolymph levels of sodium and calcium were always increased by cadmium exposure. The chronic toxicity of cadmium was enhanced at 12‰ salinity, even causing a significantly higher mortality in comparison with the higher salinity (30‰) used. A general metabolic arrest took place at 12‰ salinity in the crabs chronically exposed to cadmium, as indicated by decreases of oxygen consumption and PCO2, an increase of PO2, along with no changes in lactate levels. These imbalances were associated with severe necrosis and telangiectasia in the respiratory gills, probably leading to respiratory impairment and finally histotoxic hypoxia and death of the animals.