A broader perspective: Functional symptoms beyond Neurology.

•Functional (psychogenic) symptoms exist in all specialties.•They are by definition not under voluntary control, unlike factitious disorders and malingering.•The diagnostic approach to functional symptoms varies among specialties.

Kombucha, the fermented tea: microbiology, composition, and claimed health effects.

Kombucha is a slightly sweet, slightly acidic tea beverage consumed worldwide, but historically in China, Russia, and Germany. Kombucha is prepared by fermenting sweetened black tea preparations with a symbiotic culture of yeasts and bacteria. Potential health effects have created an increased interest in Kombucha. Yet, only a few research studies have shown that Kombucha has in vitro antimicrobial activity and enhances sleep and pain thresholds in rats. Furthermore, Kombucha consumption has proven to be harmful in several documented instances.

Comparison of lactococcal bacteriophage isolated in the United States and Argentina.

Bacteriophage of Lactococcus lactis ssp. lactis and ssp. cremoris, isolated in the United States and Argentina, were compared with respect to host range, adsorption, latent period, burst size and immunological cross-reactivity. Only 1 out of 13 U.S. culture isolates was sensitive to Argentinian phage. Argentinian L. lactis ssp. lactis C2 mutants were resistant to 13 U.S. phage isolates (4 prolate and 9 isometric). While Argentinian phage Stl-3 multiplied on U.S. culture isolate 59-1, low adsorption (38%) and insignificant burst size and latent period data were evident. Antisera prepared against U.S. phage D59-1 (prolate) and F4-1 (isometric) neutralized the lytic activities of all Argentinian prolate phage although the F4-1 antiserum was less effective. The data suggest homology especially between U.S. phage D59-1 and the Argentinian phage.

Microtiter plate assays for the measurement of phage adsorption and infection in Lactococcus and Enterococcus.

Three easy and rapid microtiter plate assays for determining phage sensitivity of lactococci and enterococci have been developed. In the microlysis assay, the degree of sensitivity was measured on the basis of the ability of the bacterial cells to grow in the presence of various concentrations of phage and to effect a color change of an acid-base indicator as a result of acid production. Two assays that specifically measure phage adsorption to bacterial cells have been developed on the basis of the enzyme-linked immunosorbent assay (ELISA) technique. In the direct phage adsorption ELISA, adsorption of phage particles to cells immobilized onto microtiter plate wells was measured using specific anti-phage antibody. In the competitive phage adsorption ELISA, phage adsorption was assayed by allowing phage to compete with specific antibody binding to the bacterial cell surface. All three assays were quantifiable photometrically.

Mutante de Streptococcus lactis con resistencia a bacteriófagos aislados en Argentina y Estados Unidos de América / A mutant of Streptococcus lactis with resistance to bacteriophages isolated in Argentina and the United States of America

Streptococcuslactis y S. cremoris, bacterias lácticas utilizadas para la producción de quesos, pueden reesultar infectadas por bacteriófago específicos, lo que ocasiona alteraciones en la calidad, disminución de la productividad económicas significativas. Los métodos de desinfección y control más usuales no siempre resultan en una completa protección contra la proliferación de los fagos, por los que se ha recurrido al empleo de cepas resistentes a los mismos. En el presente trabajo se ha empleado un método simple y directo para obtener mutantes espontáneas de S. lactis con resistencia a fagos. La mutante S.lacts C26 obtenida a partir de la cepa S. lactis C2 sensible a fagos exhibe propiedades bioquímicas y microbiológicas similares a las de la cepa original C2, diferenciándose de ella por una clara resistencia al fago St15, de morfología alargada, utilizado para la selección. Las curvas de la cinética de crecimiento de la mutante en ausencia y en presencia del fago resultaron semejantes. La cepa C26 fue controlada con otros dos fagos aislados en Argentina y con seis fagos de dos tipos morfológicos, aislados en la Universidad de Cornell en EE.UU. La cepa C26 que fuera aislada como mutante resistente al fafo St15, resultó también resistente a todos ellos. Por otra parte, ha sido de interés verficar que los fagos no siempre observan una especificidad estricta con respecto a la especie de la célula huésped. El fago D59-1, aislado utilizando una cepa S. cremoris, también provoca una lisis significativa en la cepa S. lactis C2, suiriendo que ambas poseen sitios receptores semejantes. La mutante C26 fue empleada con éxito en Buenos Aires, en la planta elaborada de quesos donde fuera aislado el fago St15, lo que alienta la posibilidad de emplear esta metodología en el desarrollo de fermentos lácticos

Mutante de Streptococcus lactis con resistencia a bacteriófagos aislados en Argentina y Estados Unidos de América / A mutant of Streptococcus lactis with resistance to bacteriophages isolated in Argentina and the United States of America

Streptococcuslactis y S. cremoris, bacterias lácticas utilizadas para la producción de quesos, pueden reesultar infectadas por bacteriófago específicos, lo que ocasiona alteraciones en la calidad, disminución de la productividad económicas significativas. Los métodos de desinfección y control más usuales no siempre resultan en una completa protección contra la proliferación de los fagos, por los que se ha recurrido al empleo de cepas resistentes a los mismos. En el presente trabajo se ha empleado un método simple y directo para obtener mutantes espontáneas de S. lactis con resistencia a fagos. La mutante S.lacts C26 obtenida a partir de la cepa S. lactis C2 sensible a fagos exhibe propiedades bioquímicas y microbiológicas similares a las de la cepa original C2, diferenciándose de ella por una clara resistencia al fago St15, de morfología alargada, utilizado para la selección. Las curvas de la cinética de crecimiento de la mutante en ausencia y en presencia del fago resultaron semejantes. La cepa C26 fue controlada con otros dos fagos aislados en Argentina y con seis fagos de dos tipos morfológicos, aislados en la Universidad de Cornell en EE.UU. La cepa C26 que fuera aislada como mutante resistente al fafo St15, resultó también resistente a todos ellos. Por otra parte, ha sido de interés verficar que los fagos no siempre observan una especificidad estricta con respecto a la especie de la célula huésped. El fago D59-1, aislado utilizando una cepa S. cremoris, también provoca una lisis significativa en la cepa S. lactis C2, suiriendo que ambas poseen sitios receptores semejantes. La mutante C26 fue empleada con éxito en Buenos Aires, en la planta elaborada de quesos donde fuera aislado el fago St15, lo que alienta la posibilidad de emplear esta metodología en el desarrollo de fermentos lácticos (AU)

[A mutant of Streptococcus lactis with resistance to bacteriophages isolated in Argentina and the United States of America]. / Mutante de Streptococcus lactis con resistencia a bacteriófagos aislados en Argentina y Estados Unidos de América.

Streptococcus lactis and Streptococcus cremoris have an important role in the fermentation of milk during the manufacturing of lactic products. Bacteriophages are spread in the plant environment and they may infect the starters causing technical and economic problems to the dairy industry. It is now known that the usual methods of control are not completely safe against the proliferation of phages. It is necessary therefore to include resistant strains to the phages which infect the plant. This study introduces a simple and direct method to obtain spontaneous mutants which have performed clear resistance to a certain phage. The prolate (ARG) phages used in this work St11, St13 and St15 were isolated in Argentina, on S. lactis C2 while the prolate and isometric (AM) phages phi C2, D59-1, I16-1, and G72-1, F4-1, I37-1 respectively, were isolated in Cornell University. on the corresponding S. lactis strains except the phage D59-1 isolated on an S. cremoris strain. The propagation of phages was performed using M and M17 broth. The phage sensitivity was tested through spot test and overlay plaque plating method expressing the titre of phage suspension. as PFU/ml. In order to obtain spontaneous resistant mutants of S. lactis C2 to phage St15, and active culture of S. lactis C2 (sensitive) was spread on agar M plates, inoculated with drops of a suspension of phage St15 (10(8)PFU/ml) and incubated at 30 degrees C for 48 h. Colonies of mutants grown in the lytic areas caused by the phage were isolated and selected.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutante de Streptococcus lactis con resistencia a bacteriófagos aislados en Argentina y Estados Unidos de América. / [A mutant of Streptococcus lactis with resistance to bacteriophages isolated in Argentina and the United States of America]

Streptococcus lactis and Streptococcus cremoris have an important role in the fermentation of milk during the manufacturing of lactic products. Bacteriophages are spread in the plant environment and they may infect the starters causing technical and economic problems to the dairy industry. It is now known that the usual methods of control are not completely safe against the proliferation of phages. It is necessary therefore to include resistant strains to the phages which infect the plant. This study introduces a simple and direct method to obtain spontaneous mutants which have performed clear resistance to a certain phage. The prolate (ARG) phages used in this work St11, St13 and St15 were isolated in Argentina, on S. lactis C2 while the prolate and isometric (AM) phages phi C2, D59-1, I16-1, and G72-1, F4-1, I37-1 respectively, were isolated in Cornell University. on the corresponding S. lactis strains except the phage D59-1 isolated on an S. cremoris strain. The propagation of phages was performed using M and M17 broth. The phage sensitivity was tested through spot test and overlay plaque plating method expressing the titre of phage suspension. as PFU/ml. In order to obtain spontaneous resistant mutants of S. lactis C2 to phage St15, and active culture of S. lactis C2 (sensitive) was spread on agar M plates, inoculated with drops of a suspension of phage St15 (10(8)PFU/ml) and incubated at 30 degrees C for 48 h. Colonies of mutants grown in the lytic areas caused by the phage were isolated and selected.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification of cell wall antigens associated with a large conjugative plasmid encoding phage resistance and lactose fermentation ability in lactic streptococci.

In order to begin to analyze the gene products encoded by phage resistance plasmids in lactic streptococci, we identified phage-resistance plasmids by screening resistant strains from commercial starter cultures for the ability to carry out unselected cotransfer, by conjugation, of phage resistance with lactose fermentation ability (lac+). In this fashion, we identified a large (90 kilobases) plasmid, pCLP51R, that encodes the lac+ marker, resistance to a lytic phage called LP10G (1pr+), high-frequency conjugal donor ability (hft+), and clumpy growth of host bacteria in broth culture (clu+). The mechanism of resistance conferred by this plasmid appears to involve interference with a step in the phage replication cycle that occurs after the initial attachment of the phage. Polyacrylamide gel electrophoresis of cell surface extracts of isogenic strains, carrying or lacking pCLP51R, combined with immunoblotting analysis, showed that there were several plasmid-related differences in the banding pattern of low molecular weight proteins and that the plasmid resulted in production of several unique antigenic polypeptides in the size range of 15-30 kd, as well as modification of chromosomally encoded antigens to different molecular weight forms.

Shelf-Life Extension of Vacuum Packaged Frankfurters Made from Beef Inoculated with Streptococcus lactis.

Fresh beef, containing .5% dextrose, was inoculated with Streptococcus lactis , incubated for 3, 5 and 7 d at 7±1°C, and then used to manufacture frankfurters. The frankfurters were vacuum-packaged and stored for 1, 2, 4 and 6 weeks at 3±1°C. Microbial quality was evaluated by examining frankfurters for aerobic and psychrotrophic counts at the end of each storage period. The level of nisin, an antibiotic substance produced by this strain of S. lactis , was also monitored in fresh meat and processed products. During the incubation period, no appreciable reduction in pH occurred in fresh meat. Growth of psychrotrophs was slower in treated than untreated fresh meat, but whether this was due to presence of nisin or competition resulting from the heavy inoculation with S. lactis is unclear. Before and after processing, nisin levels in the 5- and 7-d incubation-treated groups were higher than in the 3-d group, and all treated groups had higher nisin levels than untreated groups. Little difference in aerobic and psychrotrophic growth was noted with storage time between treated and untreated groups for the 3-d incubation period, but well defined differences were noted in the 5- and 7-d incubation groups, with aerobic growth in treated groups being significantly slowed through the 6-week storage period, and psychrotrophs being 1 to 1.5 log cycles lower at the 6-week evaluation. The growth patterns suggest that nisin played a role in the reduced growth rate of bacteria in treated groups.

Influence of Milk Aeration on Growth of Psychrotrophic Pseudomonads.

The psychrotrophic microflora of raw milk from a Cornell University herd was examined and the three most frequently occurring isolates ( Pseudomonas species) were subjected to oxygen concentrations of 1 to 12 ppm and temperatures of 3 to 9°C in growth studies in raw milk. At 3°C, a reduction in oxygen level from 9-12 to 1-3 ppm resulted in a 63% increase in generation time for Pseudomonas fluorescens . However, the reduction in growth temperature from 9 to 3°C at 9-12 ppm oxygen produced a 280% generation time increase for P. fluorescens . Similar observations were made for the other isolates. An analysis of variance revealed a significant interaction between the effects of oxygen and temperature on growth of the isolates.

Proteolytic Inactivation of Thermonuclease Activity of Staphylococcus aureus During Recovery from Thermal Injury.

Staphylococcus aureus cells were injured thermally by exposure to 55°C for 15 min and allowed to recover for various lengths of time at 37°C in Trypticase Soy Broth. During recovery, thermostable nuclease (TNase) production was measured using a turbidimetric-spectrophotometric method. Production increased during recovery until approximately 2 h after injury when the amount of TNase began to decrease unexpectedly. Protease(s) was thought to be degrading the TNase, and positive results of gelatin agar diffusion tests and heat inactivation experiments supported this hypothesis. Protease inhibitor studies with ethylene diamine tetraacetate (EDTA) and phenyl methyl sulfonyl fluoride (PMSF) confirmed the involvement of protease(s) in the observed decrease in TNase activity. Implications of TNase inactivation in screening of foods for enterotoxigenic staphylococci are discussed.

Self-report as a validity check for the Lüscher Color Test.

20 college students, in a single-group design, participated in a study of the validity of the Lüscher Color Test. The objective was to determine whether personality descriptions based on the test would significantly match written statements the subjects selected as self-descriptive. Each subject took the test twice and data from the second testing were analyzed. Later, the same subjects took a self-report test on which they rated 32 statements on a continuum from "characteristics I identify with most" to "characteristics I identify with least." The results of comparing the two tests showed a greater than chance correspondence between the test descriptions and self-report descriptions. Observed social desirability appears to account for the correlation.

Deamination of glumatic and aspartic acids by Geotrichum candidum.

Strains of Geotrichum candidum were isolated from the surface of a commercial sample of Limburger cheese and from raw milk. Growth of the isolates in an acidified tryptone-yeast extract medium was accompanied by a rise in the pH of the medium from 3.5 to above 7.0 Ammonia production, as indicated by Nesslerization, was associated with the deamination of glutamic and aspartic acids. The first reaction in the production of ammonia from glutamic acid, isomerization to beta-methylaspartic acid, required vitamin B12 and the second reaction, the deamination of beta-methylaspartic acid to mesaconic acid and ammonia, was dependent on magnesium and potassium. The conversion of aspartic acid to fumaric acid and ammonia required magnesium. These minerals were in sufficient amounts in the Limburger cheese for optimum deaminase activity.

Characterization of groups N and D streptococci isolated from rumen fluids.

Twelve strains of streptococci of serological groups N and D were isolated from rumen fluids of nine cows on four rations although both groups were not isolated from the same animal. The twelve were representative of a larger number of streptococci isolated by enrichment in milk. Generally, the physiological characteristics of the isolates indicated members of the lactic or enterococcus groups; however, several were atypical in one or more of the tolerance tests. Physiologically typical Streptococcus lactis but not S. cremoris, were isolated.

Optimum Cultural Conditions for Induction of Temperate Bacteriophages in Lactic Streptococci.

Nineteen strains of lactic-group streptococci were examined for lysogeny by treatment with ultraviolet light; eight were inducible. The effectiveness of lysogenic induction with ultraviolet light or mitomycin C depended on the dose of inducing agent, temperature of incubation, and age of the culture. Strain-specific differences in responses to all of these factors were observed; however, in general induction was most effective at temperatures of 30 C or less and when cultures were in mid-exponential growth. No single ultraviolet or mitomycin C dose would induce all eight strains. Cultures which had been frozen and thawed were generally not inducible immediately after thawing. This was attributed to inhibition of bacterial growth by freezing. Cultures which had been chilled without freezing remained inducible. Lysogenic induction was not affected by either calcium or phosphate.

Potential for Non-Specific Inhibition in the Sarcina lutea Test.

A survey of commercial milk samples for antibiotic residues, tested by the Sarcina lutea cylinder plate method, revealed a high incidence (72%) of non-specific inhibiton. Penicillin was detected by penicillinase assay in 3.1% of the samples. The method was found to be non-quantitative for residual levels of sanitizers in protein media. Apparently, substances inhibitory to S. lutea develop normally in some milks during marketing.

Microbial penicillinase in soft types of cheese.

Penicillinase activity was found in commercial samples of Limburger, Liederkranz, and Brick, as well as in Roquefort and Danish Blue cheeses. The numbers of penicillinase-producing bacteria in the cheese flora were estimated by use of the most probable numbers technique coupled with penicillinase determinations on the individual cultures. Although streptococci constituted the predominant flora in most of the samples, significant numbers of penicillinase-producing bacteria were also observed. Six of seven penicillinase-producing isolates that were studied in detail were micrococci; the other was an unidentified gram-positive, catalase-positive rod. The results suggest the widespread occurrence of penicillinase-forming micrococci on the surfaces of soft types of cheese.