Bacteriophages of lactobacilli.

Lactobacilli are members of the bacterial flora of lactic starter cultures used to generate lactic acid fermentation in a number of animal or plant products used as human or animals foods. They can be affected by phage outbreaks, which can result in faulty and depreciated products. Two groups of phages specific of Lactobacillus casei have been thoroughly studied. 1. The first group is represented by phage PL-1. This phage behaves as lytic in its usual host L. casei ATCC 27092, but can lysogenize another strain, L. casei ATCC 334. Bacterial receptors of this phage are located in a cell-wall polysaccharide and rhamnose is the main component of the receptors. Ca2+ and adenosine triphosphate (ATP) are indispensable to ensure the injection of the phage DNA into the bacterial cell. The phage DNA is double-stranded, mostly linear, but with cohesive ends which enables it to be circularized. The vegetative growth of PL-1 proceeds according to the classical mode. Cell lysis is produced by an N-acetyl-muramidase at the end of vegetative growth. 2. The second group is represented by the temperate phage phi FSW of L. casei ATCC27139. It has been shown how virulent phages originate from this temperate phage in Japanese dairy plants. The lysogenic state of phi FSW can be altered either by point mutations or by the insertion of a mobile genetic element called ISL 1, which comes from the bacterial chromosome. This is the first transposable element that has been described in lactobacilli. Lysogeny appears to be widespread among lactobacilli since one study showed that 27% of 148 strains studied, representing 15 species, produced phage particles after induction by mitomycin C. Similarly, 23 out of 30 strains of Lactobacillus salivarius are lysogenic and produce, after induction by mitomycin C, temperate phages, killer particles, or defective phages. Temperate phages have also been found in 10 out of 105 strains of Lactobacillus bulgaricus or Lactobacillus lactis after induction by mitomycin C. Phages so far studied of the latter 2 and closely related lactobacilli, either temperate or isolated as lytic, may be divided into 4 unrelated groups called a, b, c and d. Most of these phages are found in group a and an unquestionable relationship has already been shown between lytic phages and temperate phages that belong to this group. Lytic phage LL-H of L. lactis LL 23, isolated in Finland, is one of the most representative of those of group a and has been extensively studied on the molecular level.

Do physicians modify their prehospital management of patients in response to a public campaign on chest pain?

The goals of this study were to analyze the impact of a public campaign on chest pain on physicians involved in the prehospital care of patients with this symptom, in terms of physician delay, rates of immediate hospitalization, and of transportation by ambulance. Prehospital delays and decisions for all 866 patients with chest pain managed by the community and generalist physicians or by emergency physicians, who presented to the emergency department of a teaching hospital during the 12 months of the campaign, were compared with those of all 749 patients with similar presentations during the 12 months before it. When community and generalist physicians were involved, median (110 minutes) physician delay did not decrease during the campaign, whereas it decreased from 65 to 56 minutes (p <0.003) when emergency physicians were involved. Rates of immediate hospitalization (73%) and of transportation by ambulance (47%) of patients managed by community and generalist physicians were unaffected by the campaign, whereas they increased from 96% and 89%, respectively, to 98% (p = 0.09) and 94% (p <0.02) when emergency physicians were involved. Similar observations were made in patients with confirmed acute myocardial infarction and unstable angina and remained highly significant after adjustment for differences in clinical characteristics. Thus, community and generalist physicians did not significantly modify their prehospital management of patients with chest pain despite a public campaign. To be successful, guidelines on the matter have to be developed with the active participation of these physicians.

Impact of a public campaign on pre-hospital delay in patients reporting chest pain.

OBJECTIVE: To decrease pre-hospital delay in patients with chest pain. DESIGN: Population based, prospective observational study. SETTING: A province of Switzerland with 380000 inhabitants. SUBJECTS: All 1337 patients who presented with chest pain to the emergency department of the Hôpital Cantonal Universitaire of Geneva during the 12 months of a multimedia public campaign, and the 1140 patients who came with similar symptoms during the 12 months before the campaign started. MAIN OUTCOME MEASURES: Pre-hospital time delay and number of patients admitted to the hospital for acute myocardial infarction (AMI) and unstable angina. RESULTS: Mean pre-hospital delay decreased from 7h 50 min before the campaign to 4 h 54 min during it, and median delay from 180 min to 155 min (P < 0.001). For patients with a final diagnosis of AMI, mean delay decreased from 9 h 10 min to 5 h 10 min and median delay from 195 min to 155 min (P < 0.002). Emergency department visits per week for AMI and unstable angina increased from 11.2 before the campaign to 13.2 during it (P < 0.02), with an increase to 27 (P < 0.01) during the first week of the campaign; visits per week for non-cardiac chest pain increased from 7.6 to 8.1 (P = NS) during the campaign, with an increase to 17 (P < 0.05) during its first week. CONCLUSIONS: Public campaigns may significantly reduce pre-hospital delay in patients with chest pain. Despite transient increases in emergency department visits for non-cardiac chest pain, such campaigns may significantly increase hospital visits for AMI and unstable angina and thus be cost effective.

[Prevalence of smoking in hospital personnel and future teachers]. / Prévalence du tabagisme chez le personnel hospitalier et les futurs enseignants.

We have surveyed the prevalence of smoking habits and the opinions about it's regulation among 192 students in two different schools (a teachers' and a nursing school) and among 320 employees of the University Hospital of Geneva. Smoking prevalence varies depending on the profession and sex, and remains high considering the level of education of the surveyed population. Among the future school teachers 23% are smokers. In the hospital, the smoking prevalence is 25% in the health professionals and 32% in the administrative and technical staff. As many as 46% of the future nurses are smoking. Obviously much still needs to be done in order to decrease the number of smokers among the health professionals. The majority of the employees questioned, both smokers and non-smokers, were in favor of regulating smoking in the workplace. 91% of the hospital staff, and 86% of the smokers among them, favored a smoke free hospital policy. Restriction of tobacco use in the workplace should be implemented particularly when it is the wish of a majority of employees.

[Integration of new nurses in nursing units in a university hospital]. / L'intégration des nouvelles infirmières dans les unités de soins d'un hôpital universitaire.

The study presented in this article raises the problems of the integration of recently graduated nurses in the hospital from the point of view of a culture difference between the two socialisation worlds: more reflexive standards of behaviour and culture in the schools (emphasis on analysis, knowledge, care actions argumentation...) and more instrumental ones in the hospitals (emphasis on efficiency, work organisation, operationality...). An enquiry by means of interviews with recent graduates from different schools (open, semi-open and closed questions) enables to successively analyse the skills they consider to have acquired at school, the ones they consider as required by the hospital and the differences they feel between hospital and school concerning the enhanced skills. The results show a significant discrepancy between the ideal of the interviewed nurses and the reality of their work within the institutional constraints of the hospital.

Comparative Study of 35 Bacteriophages of Lactobacillus helveticus: Morphology and Host Range.

This survey included 23 phages isolated from cheese whey and 12 temperate phages induced with mitomycin from their lysogenic host strains. All of the phages had an isometric head and a tail with a contractile sheath. In addition, short-tailed (160-nm-long) and long-tailed (260-nm-long) phages were distinguished. Short-tailed phages were by far the most widespread in French cheese factories (32 of the 35 phages studied). The study of phage relationships enabled two large groups of strains to be distinguished: those not or slightly sensitive to phages and those very sensitive to phages. There was an obvious relationship in the first group between phage sensitivity (or resistance) and the geographic origin of the strains. The second group contained primarily strains from large international collections and those isolated from commercial starters. The relationships among short-tailed phages, either temperate or isolated as lytic, suggest that lysogenic strains could be the major source of phages in French cheese factories.

Evidence for a Plasmid-Linked Restriction-Modification System in Lactobacillus helveticus.

The presence of a restriction-modification (R/M) system against two bacteriophages, 328-B1 and hv, was demonstrated in three Lactobacillus helveticus strains, CNRZ 1094, CNRZ 1095, and CNRZ 1096. In addition, the burst size of phage 328-B1 in the three restrictive strains CNRZ 1094, CNRZ 1095, and CNRZ 1096 was reduced with respect to the values obtained in its propagating strain, CNRZ 328. Heating at 60 degrees C did not inactivate the R/M system. Nonrestrictive variants from CNRZ 1094 were easily obtained under several culture conditions, but treatment with novobiocin at 42 degrees C followed by storage at -20 degrees C resulted in drastic elimination of the R/M phenotype from all clones tested. Electrophoretic analysis of CNRZ 1094 nonrestrictive variants revealed the concomitant loss of a 34-kb plasmid. Four EcoRI fragments from the 34-kb plasmid were cloned in the Escherichia coli vector pACYC184. The use of one or several of these fragments as probes confirmed the plasmidic location of the genes responsible for the R/M system. These probes also showed the presence of R/M plasmids in the two other restrictive strains, CNRZ 1095 and CNRZ 1096. Lactose-fermenting ability and/or proteolytic capacity was not linked to the 34-kb plasmid.

A Lactobacillus helveticus-Specific DNA Probe Detects Restriction Fragment Length Polymorphisms in This Species.

A cloned 2-kb EcoRI fragment (fragment f) from a 34-kb plasmid of Lactobacillus helveticus CNRZ 1094 was shown by dot blot to specifically hybridize to total DNAs of 75 L. helveticus strains. No hybridization was found with L. acidophilus, L. crispatus, L. delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, L. gasseri, or L. intestinalis strains. When Southern blots of EcoRI digests of L. helveticus strains were probed with fragment f, these strains displayed restriction fragment length polymorphisms on the basis of which they could be grouped into several clusters.