Plain Broth Research Articles

Sensitive period in flavor learning: Effects of duration of exposure to formula flavors on food likes during infancy

Emerging research has revealed the existence of periods in which the developing brain has heightened sensitivity to environmental influences. We discovered a sensitive period, <4 months of age, when exposure to the flavor of extensively hydrolyzed protein hydrolysate formulas (ePHF) determines its hedonic tone. This formula has pronounced bitter, sour, and savory tastes compared to cow-milk-based formulas (CMF). This study aimed to determine the effects of duration of exposure during the sensitive period on a food containing an exemplar of the savory flavor. Formula-fed infants were randomized into four groups at age 0.5 months: one control group fed the CMF for 8 months, and three groups fed ePHF for 1, 3, or 8 months and CMF otherwise. When infants were 8.5 months, their acceptance of a savory and plain broth was measured. Infants fed hydrolysate formula for 3 or 8 months, but not 1 month, showed greater acceptance of the savory broth relative to the plain broth (p<0.01) and consumed it at a faster rate (p=0.01). The duration of flavor exposure affects infants' earliest responses to foods: a 3-month exposure to ePHF shifted the hedonic tone for savory flavor.

Haemorrhagic septicaemia vaccines

Haemorrhagic septicaemia (HS), an economically important disease of cattle and buffaloes, is caused by Pasteurella multocida (6:B). Vaccination against this disease is widely practised. Plain broth bacterins, or alum precipitated and aluminium hydroxide gel vaccines are administered twice a year since these vaccines offer an immunity of 4–6 months. Many countries use oil adjuvant vaccine (OAV), which gives both a higher degree and a longer duration of immunity up to 1 year. A double emulsion and multiple emulsion vaccine consisting of a thin viscosity have also been experimentally developed that gave an immunity parallel to OAV. Recently, a live vaccine developed from a fallow deer strain (B:3,4) has been used in Myanmar that offers an immunity for more than a year but is not free from constraints. The present review provides information on HS vaccines developed from time to time using whole bacteria or their components. The kinetics and isotype of antibody and cell-mediated immune responses have also been poorly understood so far, and hence information on their role in protection against HS is reviewed

Correlation of growth of aerobic blood cultures in hypertonic broth with antibiotic therapy.

The aim of this study was to elucidate the mechanisms by which sucrose improves growth in a hypertonic medium for isolating aerobes from blood. Clinical blood cultures were made routinely in duplicate in plain broth consisting of brain heart infusion broth with sodium polyanetholesulfonate, gelatin, and penicillinase and the same broth with 20% sucrose added. The growth patterns of Staphylococcus aureus and Enterobacteriaceae from plain and from hypertonic broth were correlated with the presence or absence of antimicrobial therapy in patients when the blood cultures were collected. In S. aureus bacteremias, 58.7% of the positive cultures collected during treatment of patients with beta-lactam antibiotics showed earlier growth or growth only in hypertonic broth, compared with 16.7% of the cultures taken during treatment with other antimicrobial agents (P less than 0.05) and 17.6% of the cultures made in antibiotic-free intervals (P less than 0.01). In the group of cultures yielding growth of Enterobacteriaceae, growth occurred earlier or solely in hypertonic broth in 28.9% of the cultures taken during treatment with beta-lactam antibiotics, compared with 15.7% of the cultures taken during treatment with other antimicrobial agents and 21.6% of the cultures collected in antibiotic-free intervals (differences not statistically significant). It is concluded that treatment with beta-lactam antibiotics is an important reason for the improved growth of S. aureus from hypertonic broth, but other factors are also involved.

A Quantitative Evaluation of Three Blood Culture Systems

Three separate blood culture systems were evaluated by parallel culture technic using clinical blood specimens. The three systems under study were a plain brucella broth, the same base medium with polyanethol sulfonate * added in a final concentration of 0.05%, and the same base broth with the polyanethol sulfonate plus sucrose in a final concentration of 30%. After the test media had been inoculated and allowed to incubate for 4 hr., pour plates were prepared from each. The purpose of this step was to determine whether there was a differenc in a blood culture system employing either polyanethol sulfonate or sucrose, or both. The results indicated that specimens from only 74 of 121 patients demonstrated positive culture results in the flask containing only the base broth, whereas 106 were positive when polyanethol sulfonate was added, and 121 were positive when both polyanethol sulfonate and sucrose were incorporated in the base medium. The quantitative results indicated that there were 15 patients from whom recovery of organisms was accomplished only from the polyanethol sulfonate/sucrose medium and an additional 33 patients from whom the total number of organisms recovered from the polyanethol sulfonate/sucrose medium was at least 30% greater than from either the plain broth or the polyanethol sulfonate broth. The results of this study indicate clearly that polyanethol sulfonate has a beneficial effect on the recovery of organisms, possibly by preventing phagocytosis and lessening the inhibitory action of nonspecific antibodies present in the blood specimen. The results also indicate the value of using an osmotic stabilizer such as sucrose to create a better environment for bacterial cells with cell wall damage.

Suitability of Various Species of Microorganisms as Food for the Free-Living Stages of Trichostrongylus colubriformis

Twelve species of bacteria and 8 of yeasts and fungi were tested for their suitability as food for the free-living stages of Trichostrongylus colubriformis. The percentages of infective larvae developing from eggs placed on cultures of the several microbial species, or on fecal cultures, were as follows: Alcaligenes faecalis, 96; Escherichia coli B, 96; Salmonella poona, 94; Salmonella sp., 92; Sarcina lutea, 93; Staphylococcus aureus, 92; Areobacter aerogenes, 85; Pseudomonas fluorescens, 85; Proteus vulgaris, 73; Arizona sp., 55; feces, 46; Bacillus cereus, 23; Pseudomonas aeruginosa, 0; Candida albicans < 1; C. guilliermondi, < 1; Keratinomyces ajelloi, 0; Mucor sp., < 1; Rhodotorula minuta, < 1; Scopulariopsis sp., 0; Torulopsis glabrata, < 1; and Trichosporon cutaneum, < 1. Infective larvae recovered from suitable species of bacterial cultures were able to exsheath in vitro or to infect guinea pigs. The life cycle of Trichostrongylus colubriformis has two phases. The adults inhabit the small intestine of a variety of hosts, mostly herbivores. The free-living stages develop to infectivity outside the host; here they live on microorganisms in the feces. The per cent of infective larvae recovered from fecal cultures is often low and varies greatly at different times. Many factors contribute to this variation. Among these are temperature, relative humidity, the type of microbe present, pH, availability of oxygen, etc. The effects of temperature and relative humidity on the development and survival of the free-living stages of this nematode were studied by Monnig (1930), Wang (1964, 1967), Andersen, Wang, and Levine (1966), and Hsu (1967). Little is known about the effects of concomitant microorganisms. Although it is generally recognized that the preinfective larvae of trichostrongyles will develop to the infective stage in Escherichia coli cultures, the effects of other enteric and soil bacteria, fungi, and yeasts are still unkown. HowReceived for publication 20 January 1970. * From part of a dissertation submitted to the University of Illinois in 1968 for the Ph.D degree in Veterinary Medical Science under the direction of Dr. N. D. Levine to whom the author expresses his appreciation. This research was supported in part by NIH Grant AI06197 to Dr. Levine. t Present address: American Cyanamid Company, P. 0. Box 400, Princeton, New Jersey 08540. ever, even if the larvae develop to the third (infective) stage, this does not assure that they will actually infect natural hosts. The first systematic experiments in which larvae of gastrointestinal nematodes developed in a medium other than feces were carried out by McCoy (1929a, b). He studied the development of Ancylostoma caninum eggs on 25 species of bacteria and one species of yeast. Growth of the larvae was best on seven species of bacteria including the common enteric bacteria E. coli, Alcaligenes faecalis, and Aerobacter aerogenes. Lapage (1933) was the first person to use E. coli plain broth cultures for cultivation of Trichostrongylus from egg to infective stage. E. coli cultures were later employed as a basic medium to determine the optimum and the highest and the lowest temperature limits for the development and survival of the free-living stages of T. retortaeformis (Gupta, 1961) and T. colubriformis (Wang, 1964, 1967). Since Herlich, Douvres, and Isenstein (1956) reported that guinea pigs could be infected with T. colubriformis, this host-parasite system has been used for testing immunity (Gordon, Mulligan, and Reinecke, 1960; Herlich, 1966b), and studying the effects of culture temperature or cold storage on the infectivity of this parasite (Ciordia et al., 1966; Herlich, 1966a). Guinea pigs were also used in the present study to determine the infectivity of the third-stage larvae (L3 's) grown on various

Effect of Polysorbate (Tween) 80 on the resistance of Pseudomonas aeruginosa to chemical inactivation

Abstract Log phase cultures of Pseudomonas aeruginosa in nutrient broth containing polysorbate 80 were much less resistant to the action of benzalkonium chloride, chlorhexidine diacetate and polymyxin B sulphate than cells grown in plain broth.

Differentiation of Listeria monocytogenes and Erysipelothrix rhusiopathiae with triphenyl-tetrazolium chloride

Experiências foram realizadas com bactérias dos gêneros Listeria e Erysipelothrix, em meios líquido e sólido, utilizando o clorêto de 2, 3, 5 - trifeniltetrazólio. A atividade enzimática redutora das listérias para o TTC foi diferente da do E. rhusiopathiae, principalmente em meio líquido e nas horas iniciais de observação. Preparações feitas para microscopia ótica e electrônica dos germes tratados com TTC revelaram a presença de granulações polares, bipolares e centrais dentro do corpo das listérias. A evidenciação de granulações coradas de formazana, intracelulares nas listérias, confirma estudos anteriores quanto à possibilidade da existência de mitocôndrias nas bactérias.

Electron microscopy of granulation in the Proteus vulgaris treated with triphenyltetrazolium chloride

Zonas citoplasmáticas de atividade redutora de TTC foram evidenciadas em células de Proteus vulgaris examinadas ao microscópio eletrõnico. As experiências foram realizadas em vários intervalos de tempo, sendo a reação, em alguns casos, estabilizada por meio de formol. Verificou-se que as granulações de formazana podiam ser removidas no interior do corpo bacteriano por meio de tratamento com acetona. O bombardeamento pelos eléctrons, quando os germes não tinham sido fixados com formol, determinou a saída das granulações do interior dos bacilos, deixando vestígios de sua presença (rompimento das membranas celulares nos pontos onde estavam localizados). A fixação com formol evitava a saída dos grânulos. O acúmulo dos cristais de formazana, internamente, nos pólos ou ao longo do corpo bacteriano, provoca sérias alterações morfológicas.

鳥型結核菌の変異に関する研究

A large quantity of avian tubercle bacillus, avian A strain which could not multiply on the plain broth agar media, was trans-inoculated on the plain broth agar media and was successively cultivated on them. By this procedure a variant strain was obtained which could multiply on the plain broth agar media. The author tried the comparative studies on the various natures of the original and varient strains, and obtained the following results:1) The multiplying rate of the variant strain on the plain broth agar media is worse than that of the original strain on the glycerine media.2) The shape of the variant is full of diversity, and coccoid ones were particularly observed in large numbers.3) The acid-fastness of the variant strain is remarkably diminished.4) The variant strain showed a marked fall of resistance to phenol and caustic soda.5) In the absence of any subatrate, the reduction rate of methylene blue is consistently speedier in the variant strain, while, as for the oxygen consumption, the endogenous respiration of the variant strain is remarkably lower than that of the original strain.

The influence of duration of pantothenate deprivation upon natural resistance of rats to a Corynebacterium.

a concentration of 4 mg per 100 g of diet. The animals were divided into 4 groups, each group being composed of about equal numbers of the 2 strains. The 4 groups were injected with corynebacterium 197 (our strain 197, the same one used previously2) after 10, 20, 30 and 40 days on experiment. Injections were all intraperitoneal. Fifteen-hundredths cc of a 24-hour plain broth culture was administered. Survivors were autopsied 20 days after injection. Several of the circumstances in the

INHIBITION OF THE BACTERIOSTATIC ACTION OF LAURYLAMINE SACCHARINATE BY ORGANIC MATTER

Laurylamine saccharinate has been tested for its bacteriostatic powers against 30 species of bacteria, namely, 6 Gram-positive micrococci, 12 Gram-positive and 12 Gram-negative 'rods'. The compound was used in concentrations of 0.0005, 0.001, and 0.005% in plain broth, broth with glycerol, and broth with glycerol and skim milk, these adjuncts representing progressively increasing amounts of organic matter. The Gram-negative bacteria were the most resistant. The bacteriostatic action of the laurylamine was progressively reduced by the organic matter. Staphylococcus aureus was not killed by 0.005% laurylamine in the medium containing skim milk. Media containing phenol were used as a measure of comparison, and similar effects of organic matter were observed. Agar also reduced the bacteriostatic power of the laurylamine.

THE EFFECT OF SODIUM CHLORIDE ON PHAGE FORMATION BY STAPHYLOCOCCI AT ELEVATED TEMPERATURES

In experiments with the K strain of Staphylococcus aureus and the K race of bacteriophage suspended in tryptose phosphate broth and maintained at 42 degrees C. it was found that the presence of 1 M NaCl produced certain drastic changes in the relationship between the host cells and the infecting virus: 1. Staphylococci grown at 42 degrees C. in plain broth or in NaCl-broth are "activated," i.e. when growth is stopped by lowering the temperature to 5 degrees C. and phage is added, the activity titre immediately displays a rise of 15- to 16-fold. 2. 1 M NaCl tends to prevent the sorption of phage by cocci and this effect is more pronounced at 42 degrees C. than at 5 degrees C. When the activation test is conducted at 5 degrees C. (the usual temperature) most of the phage is picked up by the cells and the described increase in activity titre follows. If the test takes place at 42 degrees C. there is little sorption and correspondingly little rise in phage titre. 3. Mixtures of staphylococci and phage incubated at 42 degrees C. in NaCl-broth fail to produce phage; the final plaque and activity titres are identical with the initial titres. Here, also, the influence of 1 M NaCl in preventing contact of phage with cocci appears to account for the results. 4. Similar mixtures held at 42 degrees C. in plain broth exhibit a drop of about 60 per cent in activity and plaque titres. The loss of phage may be due to adsorption on dead cells accumulating in the suspension or to the thermolability of the bacterium-phage complex, or to both.

A Salmonella Strain Isolated from Camels in Palestine

Summary A Salmonella strain, which showed the serological structure of S. kentucky but did not attack glycerol and inositol in plain broth, was isolated from the blood and organs of three camels showing enteritis and cachexia. The sera from 19 camels were examined; nine contained H- and O-agglutinins for S. kentucky and the camel strain, while the remaining 10 showed only O-agglutinis. Four camel sera, which contained H- and O-agglutinins for S. kentucky and the camel strains which do not share a common H-antigen with S. kentucky , contained only O-agglutinins for other Salmonella strains. With both strains the mortality in mice infected by the mouth was low, but residual infections of the abdominal organs and the mesenteric glands varying from about 20 to 40 per cent. of the infected animals were found three weeks after infection.

Meios de cultura econômicos preparados pela digestão tríptica da carne, segundo Hottinger

The author described the technic of the preparation of the Hottinger's broth and agar, stablishing the method for their standardization. By the cultivation of numerous species of bacteria he verified the media has high nutrient value. The fluid medium is excellent for the indol test. After 22 successive transfers on the solid medium, in presence of specific immune serum, the agglutination of the E. typhosa has not undergone alteration. The media may, with advantage, replace the plain broth and agar.

FUSOSPIROCHETOSIS

Although a large number of spirochetal diseases have been described, in only a few have the causative organisms been cultured from the blood. Larson and Barron 1 observed a patient with Vincent's stomatitis and osteomyelitis who died after seven weeks of a severe febrile illness. Two days before death a sample of the patient's blood was cultured on ascitic agar in a Novy anaerobic jar at 37 C. After a few days fusiform bacilli appeared in the culture. Attempts were made to subculture these organisms on plain agar, ascitic broth, plain broth, ascitic agar and Loffler's blood serum. No aerobic growth was observed. Growth occurred in all of the anaerobic cultures except the one containing plain agar only. Optimum growth occurred on ascitic agar. When horse blood agar was used some of the organisms exhibited a few spirals. Larson and Barron expressed the belief that the spiral organisms were modified

Utilization of Amino-Acids by Clostridium botulinum.

Our knowledge of the metabolism of Clostridium botulinum is at present scanty. Wagner, Meyer and Dozier analyzed the products of the action of Cl. botulinum on complex media but obtained little information as to the reactions by which the products had been formed. Knight, summarizing the growth-requirements of Cl. botulinum, reports that the simplest medium which will support growth contains the amino-acids proline, glycine, leucine, alanine, lysine, and cystine, together probably with traces of tryptophan and of the “sporogenes growth factor.” He suggests that Cl. botulinum may obtain its energy through the “Stickland reaction,” a coupled oxido-reduction between pairs of amino-acids. Glycine and proline act as hydrogen acceptors while alanine and leucine act as hydrogen donators in the case of Cl. sporogenes (Stickland). Therefore these amino-acids were tested to determine whether or not they are attacked directly as is true for Cl. tetanomorphum with various amino-acids (Woods and Clifton) or by coupled reactions between pairs of amino-acids. All the experiments reported below were carried out with washed suspensions of Cl. botulinum, Type B (E-44). 800 ml of plain broth plus 0.1% yeast extract were inoculated with 0.5 ml of a beef-brain culture of this organism and incubated for 20 hours at 37°C in a McIntosh and Fildes anaërobic jar. The culture was then centrifuged, the cells were washed in saline and finally suspended in phosphate buffer of pH 7.4. The suspension so prepared was immediately deaërated in vacuo. The usual Thunberg-tube method was employed for the detection of hydrogen donators and it was found that alanine and leucine were the only amino-acids of those essential for growth which reduced methylene blue readily.

THE EFFECTS OF ACIDITY UPON THE GROWTH OF PNEUMOCOCCUS IN CULTURE MEDIA CONTAINING PROTEINS

In the presence of animal fluids or their protein constituents, Type I Pneumococcus survived and multiplied at acid hydrogen ion concentrations which in the plain broth were bactericidal for these organisms. Minimal numbers of these cells readily produced pneumococcus growth in serum broth when adjusted at hydrogen ion concentration as great as pH 5.5 with hydrochloric, or to pH 6.5 with acetic acid. Growth of the pneumococci could be demonstrated in serum broth adjusted to pH 5.0 with hydrochloric, or to pH 5.5 with acetic acid although at these hydrogen ion concentrations, large amounts of inoculum were necessary. Similar results were obtained with broth to which certain animal proteins were added and in serum broth which was previously heated by autoclave at 20 pounds pressure for 20 minutes. Pneumococcus growth proceeded at a more rapid rate in serum dextrose broth at pH 6.5 than in dextrose broth alone at the optimal hydrogen ion concentration of pH 7.8. At pH 6.0 large numbers of pneumococci failed to produce the same amount of growth in serum dextrose broth as at pH 6.5 or in dextrose broth alone at pH 7.8. It is of interest that in serum dextrose broth cultures, the stationary and decline phases of pneumococcus growth were prolonged and cell death delayed in comparison with cultures in dextrose broth alone.

Action of Ultra-violet on Members of the Pseudomonas fluorescens Group

The early theory of the destructive action of ultra-violet rays on bacteria was that hydrogen peroxide was produced in the medium. Oker-Blom1 proved that the death of the bacteria was not caused by hydrogen peroxide, but by the direct action of the rays on the protoplasm of the organism. Burge and Neill2 found fluorescent organisms to be more resistant to ultra-violet than colon organisms. They attributed the superior resistance of the members of the fluorescent group to their power of converting the short waves into long ones, and thereby escaping the coagulative action of the short waves on the protoplasm.The investigation reported in this paper was undertaken to determine whether the pigment produced by organisms of the genus Pseudomonas protects these organisms from radiant energy furnished by a quartz mercury-vapor lamp.A suitable medium for irradiation was first considered. Both plain broth and lactose broth were found unsuitable because they protected the organism from the effects of the ultra-viol...

Production of Small-Colony Variants of Staphylococcus aureus.

We have previously reported the production of small-colony variants, or G forms, after prolonged serial transfer of S. aureus in lithium chloride broth or plain broth media.1, 2 Swingle3 subsequently confirmed these results and also obtained these forms after extended growth in nutrient broth or casein-digest medium. Under these conditions the variants occur only rarely and in small numbers, seldom exceeding 1.0% of the colonies on a plate. Chinn4 in a study of the metabolic activity of the small colony variants of S. paradysenterio Sonne and S. aureus found them to be metabolically far less active than the normal forms, having a reduced generation-time, reduced fermentative powers, lessened ability to reduce methylene blue and a slower cataphoretic velocity. This lowered metabolic activity and the ability to revert to forms identical with the parent culture furnishes some evidence that small-colony variants may be forms whose metabolism has been greatly reduced by some unknown factor.Quastel and Woolridg...

Typhoid Leukocidin

Typhoid leukocidin may readily be demonstrated in the filtrate of a 24-hour culture of Eberthella typhosa grown in plain sodium chloride veal infusion broth, pH 7.4–7.6, without addition of peptone. Typhoid leukocidin passes readily through Berkefeld N, Chamberland L3, and Seitz EK filters. The leukocidin may be adsorbed by the filter unless suitable precaution is taken. The demonstration of leukocidal activity may be accomplished by the Neisser-Wechsberg method as used by Gay and Oram, but we have used a method of direct determination which is simple in principle and has yielded more satisfactory quantitative and qualitative data than the older method. For this purpose we have utilized normal rabbit's blood and non-immune human blood. The blood is collected directly into heparin, mixed, and distributed to tubes before there has been any opportunity for the leukocytes to settle out. Equal volumes of varying dilutions of the toxic filtrate are quickly added to the tubes of blood; appropriate control tubes of blood plus plain broth are always included. The tubes are sealed with paraffined corks and incubated at 37°C. in a rotating box for one hour. Following incubation, the tubes are transferred immediately to a mechanical blood-pipette shaking device and agitation is maintained until total white cell counts and films for differential counts can be obtained. It is necessary to have as many pipettes and counting chambers as there are tubes, to insure a minimal difference of time between the taking of the different counts. Tubes for counting are selected at random rather than in the order of dilution of the filtrate. Counts of control tubes are essential. After the differential counts have been completed, the total number of leukocytes of each type is calculated and the data plotted in order of dilution of the filtrate.