Don W. Micks

Free amino acids in adult mosquitoes.

Summary The free amino acids of adult, female mosquitoes (Culex pipiens, Culex quinquejasciatus, Culex salinarius, Aedes aegypti, Aedes sollicitans, Culiseta inornata and Anopheles quadrimaculatus) were extracted with ethanol and identified by paper chromatography. Extracts of all species of mosquitoes contained 18 amino acids: Alanine, glutamic acid; beta-alanine, isoleucine, leucine, taurine, proline, histidine, serine, valine, methionine, threonine, lysine, arginine, aspartic acid, glycine, tyrosine and tryptophan. Extracts of C. quinquejasciatus and A. aegypti exhibited relatively larger amounts of most amino acids than those of A. quadrimaculatus as indicated by the size and intensity of spots on the ehromatograms. Such differences between 3 species of Culex mosquitoes and 2 species of Aedes were practically negligible.

Free amino acids in the developmental stages of the mosquito.

Summary (1) The free amino acids of mosquito eggs, larvae (4th-stage), pupae and adults (males and females) were extracted with ethanol and identified by paper chromatography. The following amino acids were found in the various stages studied: alanine, glutamic acid, β-alanine, isoleucine, leucine, taurine, proline, histidine, serine, valine, methionine, threonine, lysine, arginine, aspar-tic acid, glycine, tyrosine, and tryptophan. (2) Extracts of pupae contained lower concentrations of most amino acids than the other stages, with the greatest drop occurring shortly before emergence of the adults. Other quantitative variations from one stage to another involved only 2 or 3 amino acids.

Antibacterial activity of hydrolyzed red blood cells in vitro.

Summary Red blood cells of various animals were submitted to enzymatic hydrolysis in alkaline medium, the resulting products exhibiting in vitro marked antibacterial activities. The latter covered a relatively wide spectrum of most gram-positive and a few gram-negative organisms. The highest activity was displayed by hydrolysates of human and bovine hemoproteins. Hydrolyzed bovine hemoglobin powder likewise exhibited antibacterial properties. These antibacterial products are heat-resistant and water-soluble. Their optimum activity lies in the pH range of 7.0 to 8.0. It is assumed that the active principle of the crude substance is a peptide-amino acid complex. This complex proved to be nontoxic to guinea pigs and albino mice. Its relation to other antibiotics is discussed.

Infrared Spectrophotometry as a Means for Identification of Mosquitoes.

Summary Crude aqueous extracts of Culex molestus, Culex quinquefasciatus, and Aedes aegypti adult mosquitoes were identified by infrared spectrophotometry. The most important differences were the relative intensities of the peaks at about 6.95 and 7.2 μ, and the relative depth and shape of the broad band from about 8.6 to 10 μ.

Effect of Sanguinin, an Antibacterial Agent from Blood,∗ on Streptococcal Infection in Mice

Summary and Conclusions The blood hydrolysate Sanguinin was tested in vivo in 268 albino mice accompanied by 221 untreated controls for its effectiveness against the beta-hemolytic Streptococcus zooepidemicus. Sanguinin solution (20 mg/ml) was inoculated subcutaneously (0.25 to 1.0 mg/mouse daily, usually for 4-6 days) either prior or after infection. Suppressive effect on the course of the infection was noted in all series of treated mice. A significant increase in survival time was noted in the pretreated series with an average survival percentage of 38.9 compared with 6.0 of the total of untreated controls. It does not appear that a direct correlation can be established between the survival rates and the intake of Sanguinin or the length of its administration, however, pretreatment seems to be of decisive value.