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Seventy-six halophilic vibrio strains were isolated from different marine sources such as coastal waters, fishes and mussels. Twenty strains were identified as Vibrio parahaemolyticus, 44 as Vibrio alginolyticus and 12 other strains could not be classified because of their atypical biochemical activities. Further investigations are necessary in order to assess if the present strains of V. parahaemolyticus can have a role in food poisoning outbreaks or human sporadic enteritis in our geographic area.

A new Salmonella serotype with the antigenic formula 16:i:l,w and named S. pisa is described. The strain was recovered from the feces of a healthy person who had suffered enteritis during a previous sojourn in Ghana. The W.H.O. Salmonella Centre of Paris confirmed the antigenic structure and agreed with this designation.

After a review of the taxonomic history of the genus Arizona culminated in the insertion of these bacteria in the Kauffmann-White schema, the most significant references concerning their pathogenicity and occurrence are related. In this paper, the outbreaks and sporadic cases by S. arizonae which occurred in Tuscan area during 1969-1978 are reported; between several animal species, turkeys were found frequently infect and the same serotype (S. arizonae 18:Z4,Z32:-) was identified. The epidemiological connections with the infection of turkeys and of other animals, humans inclusive, are discussed.

A series of cases of postoperative gastroenteritis by Salmonella bredeney in a general surgical ward has been described. The particular serotype of Salmonella in question, the widerange of drug-resistance of the strains, the epidemiological stages of the outbreak and the kind of the ward interested have been considered of uncommon occurrence.

Two outbreaks of Cl. perfringens food poisoning which occurred in Florence during 1976 have been described. The first one involved three hundred primary school children; processed re-heated turkey meat was thought to have been the vehicle of infection in the school meal. The clinical symptoms consisted of mild diarrhoea in all cases and the duration of the illness was about 12 hours. The possible part played by food storage temperature, post-cooking periods and food trolleys in the spread of infection is discussed. The other outbreak interested three people who ate a dish with gravy in a restaurant; one of these suffered severe haemorrhagic enteritis and died after two weeks. Necroscopy was performed and the results of post-mortem examination as well as histological and bacteriological findings certified that the cause of death was severe enteritis (Necrotizing enteritis) in elderly debilitated patient (with diabetes, chronic bronchitis, arteriosclerosis and previously gastroresected).

Comparative experiments were carried out on samples of sea water at different degrees of natural pollution. The aim of such experiments was the quantitative estimation of coliforms and salmonellae and their respective phages. The results obtained show that it is thus possible to get better informations regarding the nature and degree of water pollution, than these obtained by the E. coli count alone.

The distribution of Salmonella agglutinins among 390 normal sera from people living in the district of Pisa is described, and the relation of these findings with the Salmonella serotypes occurring in the same area is discussed. Clusters of agglutinins for several O and H antigens were found at or above a titre of 1:20, in many samples. In order to explain the significance of such antibodies and their origin an identical survey was carried out on some sera from patients with chronic liver disease, using the same antigens suspensions. The results from healthy persons compared with the increased antibody titres detected in liver patients support the hypothesis that the anti-Salmonella agglutinins may be originate by various antigenic stimuli which may be specific or most frequently non-specific, since it is well established the cross-reactivity between both the somatic and flagellar antigens of Salmonella and those of other organisms.

A survey was carried out in order to ascertain the reliable conditions for the recovery of E. coli K12 after acquisition of extrachromosomial resistance from polyresistant strains of Salmonella bredeney, responsible for a hospital outbreak of gastroenteritis. In particular in this study the length of mating, the amounts of partners in the cross-cultures, the availability of different media for selection of recipient E. coli, were controlled. It was possible to conclude that the incubation of cross-cultures during 18 hours at 37 degrees C was suitable for a greater transfer, whereas the amount of donor and recipient cells in the starting cultures was of little importance. Attempts to use synthetic media for the selective recovery of E. coli which had been made drug-resistant were not successful; instead some of lactosate media which are classically employed for the diagnosis of enterobacteria (Endo agar, Mac Conkey agar, Desoxycholate Lactose agar, Brilliant Green Bile agar, Eosin Methylene Blue agar, Violet Red Bile agar, Wurtz agar) gave satisfactory results. Among these media the two last were the best because they provided good differentiation between the prevalent Salmonella colonies and the few lactose-fermenting colonies, even in the crowded growth areas of the plates.