The Salmonella genus comprises over 1700 serotypes of pathogenic enteric bacteria. These microorganisms colonize in the intestinal tracts and mesenteric lymph nodes of man and lower vertebrates. Intra-and intergenus transfer of the lnfection(s) is common. Salmonellosls is highly contagious, and is frequently a cause of "food poisoning" in man. Estimates of 100,000 to 2 million human cases with 500 deaths occur annually in the U.S. The disease in man and animals has not decreased during the last decade. Fecal contamination, by either symptomatic or occult carriers and shedders, is the primary transmission source of aalmonellosis. The salmonellae problem and its possible resolution are intimately associated with the environment: waste disposal, including water and land use; food and feed processing, transportation and storage; livestock, poultry and dairy production; freeliving and captive wildlife hosts as infection reservoirs; household pets and companion animals; various stress factors affecting man and food-producing animals; wholesale and retail marketing of fresh and frozen foods, and ultimately the consumer, including restaurants, involved in handling, preparation and storage of foods destined for the dinner table. Salmonellosis cannot be eradicated in the U.S. due to the environmental complexities of the problem. We can only hope for better preventive and control measures through greater efforts in research, surveillance and education as well as awareness of the national problem. 755

The activities against the eggs and young mites of the glasshouse red spider (Tetvanychus telavzus L.) have been determined for a series of benzyl phenyl sulphides containing only halogen nuclear substituents. The results, together with the results from some of the corresponding sulphoxides and sulphones, are tabulated and discussed. Introductiona description has been given of the activities against the red spider mite, in laboratory tests, of a series of SS'-disubstituted alkane-am-dithiols and, also, of a series of compounds consisting of two benzene nuclei linked by various sulphur-containing bridges. During the preparation of the latter series of compounds, benzyl phenyl sulphide was synthesized and, although the activity of this unsubstituted parent compound was low, it soon became apparent that substitution by halogens in either or both of the benzene nuclei had a profound effect on the activity. As, in addition, these compounds had little or no phytotoxicity, a series of benzyl phenyl sulphides containing only halogen nuclear substituents was prepared and tested.Many of the sulphides were oxidized to the corresponding sulphoxides and sulphones which were also tested for activity, since there was evidence to indicate that oxidation of 9-chlorobenzyl p-chlorophenyl sulphide (chlorbenside) could occur after application on leaf surfaces. 3

Many aryl N-methylcarbamates and their N-acyl derivatives have been prepared and tested against larvae of the sheep blowfly, Lucilia sericata. Mammalian toxicities and persistences on sheep fleece were also determined. The factors which led to the selection of Butacarb (3,5-di-t-butylphenyl N-methylcarbamate) as a new veterinary insecticide are discussed.

Two selective enrichment media were developed for the isolation of salmonellae from foods. The first, experimental broth 1, contained magnesium chloride and sodium cholate as the selective ingredients.

Laboratory and field test methods are described for assessing the activity of chemicals for the control of sheep blowfly Luciliu sericatu (Meig.). The essential properties for a sheep blowfly insecticide are discussed. Screening results for several series of sulphonamides and disulphonamides, with and without N-substituents, are presented. Although some disulphonamides showed high activity, none had the necessary persistence for use in a sheep-dip.