Inactivation of Salmonella during microwave cooking.

Sixty meat loaves were experimentally infected with a strain of Salmonella serovar mbandaka to give approximately 10(7) cells/g. Thirty contaminated loaves were cooked in a microwave oven for 4 min, and 30 other samples for 3 min 30 s, both followed by a standing time of 2 min. No viable experimental contaminants were recovered from both core and surface samples of the 30 loaves cooked for 4 min. Loaves cooked for the short time were often Salmonella positive. These results point out that infection hazard linked to microwave cooked food can be avoided by following adequate procedures concerning exposure time, temperature and post-heating holding time. A standardization of microwave ovens for domestic use is desirable, making it easier to give users correct instructions based on careful and strict experimentations approved by Public Health Authorities.

[Stationary and migratory avifauna as reservoirs of Salmonella, Yersinia and Campylobacter]. / Avifauna stanziale e migratoria come riserva di Salmonella, Yersinia e Campylobacter.

Domestic and wild animals have been always considered very important as reservoir of agents of human infections. Particularly birds, because of their great mobility from a continent to another or within the limits of the same ecosystem may transfer pathogenic micro-organisms. The present survey was undertaken in order to evaluate the presence of Campylobacter, Yersinia and Salmonella in migratory and permanent birds. During the period October 1986 to March 1988 intestinal loops were collected from a total of 217 birds representing 17 different species shot, during hunting seasons, in the inland of Versilia in the district of Lucca. Each sample was divided into three parts and examined for the presence of Campylobacter, Yersinia and Salmonella. Campylobacter was isolated from 74 of the 217 birds examined (34.10%). Yersinia was recovered from 26 birds (11.98%), while only 8 birds (3.68%) harboured Salmonella. Most of the samples carried only one of the three bacterial genera investigated while 9 harboured at the same time Yersinia and Campylobacter, 1 Salmonella and Campylobacter, and 1 Salmonella, Yersinia and Campylobacter. Campylobacter spp.: On the ground of Lior's biotyping scheme, the 74 strains, isolated from 16 of the 17 species of birds examined, have assigned to three biochemically different species. C. coli was the most commonly isolated followed by C. jejuni and C. laridis. Of the 54 isolates of C. coli 30 belonged to biotype I and 24 to biotype II. 19 C. jejuni organisms were differentiated into 5 belonging to biotype I and 14 to biotype II. The only C. laridis isolated belonged to biotype I. Yersinia spp.: 37 strains belonging to the genus Yersinia were isolated from 26 birds. In 10 samples different types of Yersinia were identified. Most of the strains could be ascribed to Yersinia enterocolitica (28 strains), 3 to Yersinia frederiksenii, 3 to Yersinia intermedia and 1 to Yersinia pseudotuberculosis. 2 strains were identified as atypical Yersinia. Salmonella spp.: 8 strains belonging to the genus Salmonella were isolated from 3 different species of birds. The isolates were identified as Salmonella typhi-murium (7 strains) and Salmonella blockley (1 strain). Salmonella has been isolated from 8 birds, six of which were pheasants shot during the same day in the same area and probably coming from the same breeding. In fact, in Tuscany, pheasants are bred and then set free in many hunting areas.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacterial species detected in some bottled mineral waters sold in Italy.

A total of 51 samples from 32 different kinds of mineral water were examined to investigate their microbial facies in view of a possible relationship with ionic composition. No difference was found between mineral and oligomineral waters. The genera most represented were Pseudomonas, Flavobacterium and Alcaligenes; only rarely could members of these genera be assigned precisely to a defined species, because many strains showed intermediate patterns. The authors suggest widening the microbiological examination of mineral waters and improving ecological and taxonomic knowledge of the autochthonous species in all processing phases in order to evaluate not only their compliance with the law, but also the variations imposed on microflora by different conditions related to container materials, time and temperature of storage.

Molecular study on Salmonella enteritidis strains from a nosocomial gastroenteritis outbreak.

A molecular epidemiological analysis was carried out on S. enteritidis isolates identified at the Central Italy Enterobacteriaceae Center during 1986. 26 of these were from a diarrhoeal disease outbreak, which occurred in the period April-June at the "S. Chiara" Hospital, Pisa. All S. enteritidis strains harboured a virulence-encoding 39 MDa plasmid. The nosocomial isolates made in June 1986 carried an additional non-conjugative plasmid of 75 MDa, associated with the streptomycin-resistance. In contrast, the nosocomial S. enteritidis strains isolated during the period April-May and 16 isolates from the same geographic area were susceptible to antibiotics and showed a different plasmid pattern. According to the plasmid profile and antibiotic resistance pattern analysis, it could be argued that the hospital cases of S. enteritidis infection occurring after May 1986 are attributable to a strain having different origin from the strain circulating in April-May 1986.

A molecular study of Salmonella strains identified from two food-poisoning outbreaks.

A molecular epidemiology study was carried out on Salmonella mbandaka and Salmonella corvallis strains identified from two food-poisoning outbreaks which occurred in August 1985 in Pistoia and in October 1985 in Sant'Ilario d'Enza (RE). All the Salmonella mbandaka strains were plasmid-free; all the epidemic Salmonella corvallis strains, in contrast to the non epidemic isolates, carried a small plasmid of approximately 2 MDa molecular weight. Restriction enzyme cleavage pattern analysis revealed that the plasmids of the epidemic strains were closely related.

Search for acid-fast bacilli in bottled mineral waters.

Samples of bottled mineral water sold in Italy in accordance with the law on microbiological standards were examined for the presence of acid-fast bacilli. Eighty-four samples were tested, 11 with added carbon dioxide and 73 without. Acid-fast bacilli were found in 1 of the former samples and in 8 of the latter, a total of 10.7%. The mycobacterial count was always very low (2-3 cfu/litre) except for one sample which showed large numbers of Mycobacterium sphagni. This finding was not confirmed in two following samplings of the same water. The other acid-fast bacilli isolated were: M. gordonae (four strains), M. flavescens (one strain), M. phlei (one strain) and Nocardia sp. (two strains) in two samples of different water. These bacilli are not thought to be a normal component of the waters but are the result of incidental contamination. The risk of infection from drinking such waters can be regarded as irrelevant in hospitalized or immunologically compromised subjects who fact a greater risk when using tap water for drinking or washing.

[Epidemiological remarks on the "S. Arizonae" strains isolated from various animals in tuscany during 1969-1978 (author's transl)]. / Osservazioni epidemiologiche su isolamenti di "Salmonella arizonae" da animali vari in Toscana nel periodo 1969-1978.

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 new serotype of Salmonella: "Salmonella pisa (16:i:l,w)" (author's transl)]. / Identificazione di un nuovo sierotipo di Salmonella: "Salmonella pisa (16:i:l,w)".

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.

[Serological recognition of agglutinins against O and H antigens of various Salmonellae in "normal" adult subjects]. / Ricognizione sierologica di agglutinine verso antigeni "O" e "H" di varie salmonelle in soggetti adulti "normali".

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.

[Drug resistance of Shigella strains isolated in Central Italy during 1969-1976 (author's transl)]. / Antibiotico-resistenza di stipiti di Shigella isolati nel periodo 1969-1976 nell'Italia Centrale.

Only ninety-three strains of Shigella, eightyseven of which have been identified as S. sonnei and six as S. flexneri were collected during 1969-1976 at the Pathogen Enterobacteria Centre of Pisa in Central Italy, as evidence of an epidemiological situation marked by a rare occurrence of syndromes related to these organisms. The collected strains were tested with disks of nine antibacterial drugs in common use: the survey detected sensitivity of all the strains to cephaloridine, ampicillin, carbenicillin, kanamycin and gentamicin, whereas a fair percentage of resistance appeared to streptomycin, tetracycline, chloramphenicol and cotrimoxazole. Both within multiresistant strains and those characterized by single resistances (forty-three of them in all), were present strains capable of transferring different drug resistance patterns to E. coli K-12, as evidence of being under extrachromosomial genetic control.

["S. wien" and "S. bredeney" plasmidic resistance to disinfectant agents and antibiotics (author's transl)]. / Resistenza plasmidica a disinfettanti ed antibiotici in S. wien e S. bredeney.

Several antiseptic and disinfectant compounds have been investigated for their minimal inhibitory concentration (MIC) against antibiotic multiresistant strains of S. wien and S. bredeney as well as S. typhi and S. typhimurium strains characterized by wide spectrum of antibiotic sensitivity. The MICs of AgNO3, merthiolate, NaN3, phenol, Zephiran and Desogen were not substantially different for the former and the latter strains; on the contrary, the HgCl2 minimal inhibitory concentration was significantly higher against S. wien and S. bredeney than against the other strains. The mercury resistance appeared plasmid controlled and transferable to E. coli K-12, always associated with antibiotic resistance. The findings, which confirm the results of other AA., seem unrestrictive of the use of HgCl2, because its not probable selective role in the hospital environment.