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1. Circumstantial evidence suggests that the ability of the host to prevent the uptake of iron by pathogenic bacteria may constitute an important means of defence. A detailed biochemical study of the way antisera exert theft antibacterial effects and the possible involvement of iron has now been initiated. 2. Work with Pasteurella septica antiserum has revealed a totally unsuspected way in which antiserum and complement exert their antibacterial effects. The process is very quick arid specific and resets in the cessation of bacterial multiplication; cells in stasis then appear to be killed by the operation of a secondary event. The inhibitory process operates by affecting the biochemistry of the bacterial cell leading first to an inhibition of net RNA synthesis and then to an inhibition of all macromolecular synthesis. 3. The presence of free iron in the serum did not prevent the initiation of the inhibition but it did allow macromolecular synthesis, cell multiplication and rapid growth to be resumed later. In contrast, the presence of haematin in the serum allowed the cells to continue multiplying in the presence of antiserum without delay. Addition of haematin to bacteria which had been inhibited by antiserum restored net RNA synthesis immediately. Net protein synthesis and multiplication were restarted within 15-20 min and DNA synthesis in 40 min. [ABSTRACT FROM AUTHOR]

Focuses on the vaccination trial of dogs against infections of Echinococcus granulosus. Vaccination with freeze-dried preparations from either tapeworm tissue of scolices of E. granulosus; Failure of crude antigen complex to prevent worms developing from a subsequent challenge with scolices; Number of segments and lengths of the subterminal and terminal segments of E. granulosus.

The effect of conglutinin and immuno­conglutinin preparations on the resistance of animals has been studied in seven bacterial infections. In six infections —Salmonella typhimurium, Pasteurella septica, Klebsiella pneumoniae, Listeria monocytogenes, Streptococcus pneumoniae and Streptococcus pyogenes—higher survival rates were demonstrated in mice previously injected with the conglutinin preparations. Infection with avirulent strains or non-pathogenic organisms in numbers large enough to cause death led to severe toxaemia against which the injection of conglufinin preparations failed to protect. Although the conglutinin preparations failed to protect against avirulent or unadapted strains, they did protect against virulent or adapted strains of the organisms. Experiments undertaken to define the protective factor in the serum preparations indicate that the protective factor probably is the same as that which is responsible for the conglutinating activity, conglufinin. [ABSTRACT FROM AUTHOR]

Some interrelations between the conglutinating activity of the serum of an animal and experimental bacterial infection were investigated. The passive transfer of conglutinating activity was demonstrated. The level of this activity reaches a peak within 2 days after subcutaneous injection, then declines until no significant titres are demonstrable in 12 to 14 days. It is shown that infection of animals with Salmonella typhimurium causes a rapid reduction in the conglutinating activity of the serum immediately after challenge. Evidence is presented which indicates that the previous injection of conglutinin preparations enhances bactericidal activity of the mouse against Salm. typhimurium. [ABSTRACT FROM AUTHOR]

A bacteriological study was made to see whether selected contents of public health nursing bags were contaminated by pathogens common in a "normal" environment. No pathogenic bacteria were identified, but three nonpathogenic organisms were found. More attention was given to protection from contamination. [ABSTRACT FROM AUTHOR]

The article presents a study that aims to analyze the effects of active policy of inquiry, follow-up and disposition of investigation initiated by the Office of Tuberculosis Control (OTC) of Nassau County, New York. The study was conducted during the calendar year 1970, for the newly reported cases of tuberculosis which were classified by the source of the information to assess the impact of routine investigative work. The study revealed that about 25 percent of newly reported cases of tuberculosis in the county resulted from the direct investigation conducted by OTC, which is the result of an active approach of obtaining disposition for all suspicious reports received.