Efficacy of safety catheter devices in the prevention of occupational needlestick injuries: applied research in the Liguria Region (Italy).

Healthcare workers who use or may be exposed to needles are at risk of needlestick injuries, which can lead to serious infections by bloodborne pathogens. These injuries can be avoided by eliminating the unnecessary use of needles and using safety devices. The present study was aimed at evaluating the impact of a safety-engineered device, with passive fully automatic needlestick protection, on the rate of needlestick injuries among healthcare workers. The setting of the study was a network of five public healthcare institutions situated in a Northern Italian Region. Data on the type of device, the number of employees and the number of catheter devices used per year were collected through regular meetings with healthcare workers over a period of five years. The most notable result of this study was the huge risk reduction associated with safety devices. Indeed, the risk of needlestick injuries due to conventional devices was found to be 25-fold higher than that observed for safety devices. However, it is noteworthy that a considerable part of this excess can be explained by the different background number of devices used. Moreover, descriptive analysis suggested that individuals with a poor/moderate training level had a lower risk than those with good/high training, though the difference was not statistically significant. In conclusion, there is convincing evidence of a causal connection between the introduction of safety devices and the reduction in needlestick injuries. This consideration should prompt the introduction of safety devices into daily clinical practice.

Synthesis and biological evaluation of 2-, 3-, and 4-acylaminocinnamyl-N-hydroxyamides as novel synthetic HDAC inhibitors.

A new series of 2-, 3-, and 4-acylaminocinnamyl-N-hydroxyamides 1-3 have been prepared, and their anti-HDAC (against maize HD2, HD1-B, and HD1-A enzymes) activities have been assessed. Cinnamyl-hydroxyamides bearing acylamino substituents at the C2 position of the benzene ring (compounds 1a-g) showed very low HDAC inhibiting activities, with IC(50) values in the high micromolar range. By shifting the same acylamino groups from C2 to C3 (compounds 2a-g) as well as C4 (compounds 3a-f) position of the benzene ring, a number of highly potent HDAC inhibitors have been obtained. In the anti-HD2 assay 3c (IC(50) = 11 nM) was the most potent compound, being >11600-, 4.5-, and 10-fold more potent than sodium valproate, SAHA, and HC-toxin, respectively, and showing the same activity as trapoxin. HD1-B and HD1-A assays have been performed to screen the inhibitory action of 1-3 against mammalian class I (HD1-B) and class II (HD1-A) HDAC homologous enzymes. From the corresponding IC(50) data, a selectivity ratio has been calculated. In general, compounds 1-3 showed no or little selectivity towards the class II homologue HD1-A, the most selective being 2a with class II selectivity ratio = 4.3. About the inhibitory potency, the 4-(2-naphthoylamino)cinnamyl-N-hydroxyamide 3f showed the highest inhibiting effect against the two enzymes (IC(50-HD1-B) = 36 nM; IC(50-HD1-A) = 42 nM). Selected 2 and 3 compounds will be evaluated to determine their antiproliferative and cyto differentiating activities on HL-60 cells.

Restoration-related salivary Streptococcus mutans level: a dental caries risk factor?

OBJECTIVES: The salivary level of Streptococcus mutans related to filled teeth was compared with the levels related to decayed and sound teeth, in order to establish whether the presence of restorations may increase the risk of infection of other teeth by Streptococcus mutans. METHODS: The sound, decayed and filled teeth were recorded in 809, 6-7-year-old school-children. Salivary Streptococcus mutans detection (i.e. more than 1 x 10(4) CFU/ml) and counts were evaluated. Streptococcus mutans log count means and prevalence values of subjects with only sound teeth (group 1), with filled, without decayed teeth (group 2), with decayed, without filled teeth (group 3), were calculated and compared using the Student's t-test and the chi-square test. The effect of filled, decayed and sound teeth on Streptococcus mutans level was also evaluated using logistic regression. RESULTS: Log count means and prevalence values of group 2 subjects were significantly lower than values of group 3 subjects (means, 0.92 vs 1.66: prevalence, 73.17% vs 94.63%) and statistically not-different from values of group 1 subjects (mean. 0.75: prevalence, 70.06%). The logistic regression analysis showed that the factors significantly increasing the risk of Streptococcus mutans being detected in saliva were only primary and/or permanent decayed teeth. The risk of Streptococcus mutans being detected in saliva was not affected by filled teeth more than sound teeth. CONCLUSIONS: In the present study population, the salivary Streptococcus mutans level attributable to filled teeth was low; this suggests that treatment of a carious lesion would cause a lowering of Streptococcus mutans concentration to the same levels as those shown by healthy subjects, thus reducing the risk of infection to other teeth.

Production of bacteriolytic enzymes as a tool for characterizing enterococci.

Bacteriolytic enzymes secreted by log-phase cultures of enterococci (Enterococcus faecalis, Ent. faecium, Ent. durans, Ent. hirae, Ent. casseliflavus, Ent. avium, Ent. mundtii) were analysed by means of a zymogram technique to resolve activities according to the size of their polypeptide component and their specificities towards different substrates. Heterogeneous patterns of lytic activity were observed with different species. For each test substrate, homogeneous patterns of lytic activities were observed with strains of the same species, except for Ent. faecalis strains, which showed heterogeneous lytic patterns even towards the same substrate, and could be divided into at least four different groups according to their lytic pattern. No lytic activity was common to all strains tested. Results of zymogram analysis of Enterococcus bacteriolytic enzymes were consistent with current knowledge on enterococcal taxonomy, indicating that this analytical approach may be a useful tool for fine-tuned characterization of different enterococcal strains.

Effect of sucrose consumption on level of Streptococcus mutans in saliva.

The aim of the present paper was to study whether sucrose consumption may affect the level of salivary Streptococcus mutans. The study was justified by the disagreement between results of "in vitro", animal and human experiments and results of epidemiological studies made on study-populations. According to experimental research, sucrose availability promotes Streptococcus mutans selection and development in the oral cavity. On the other hand, the results of epidemiological studies run counter to these experiments. In the present study, the main reasons for this disagreement were investigated and identified. From this, an epidemiological study was performed, taking into account these potentially confounding factors. The results show that sucrose consumption is actually able to promote Streptococcus mutans selection and development in the oral cavity, thus increasing the risk of dental caries.

A rapid staining procedure to demonstrate glycocalyx production and bacterial biofilms.

A novel staining procedure to demonstrate glycocalyx production by clinical isolates is presented. The short times required, specificity and sensitivity suggest that the staining could be applied to routine in vitro diagnostic procedures.

Identification of an Escherichia coli periplasmic acid phosphatase containing of a 27 kDa-polypeptide component.

An acid phosphatase containing a 27-kDa polypeptide component has been identified in Escherichia coli by means of a zymogram technique. The enzyme is secreted in the periplasmic space and is able to hydrolyze several organic phosphate esters, but not diesters, showing preferential activity on p-nitrophenyl phosphate and other phenolic phosphate esters. Production of the enzyme apparently occurs only in cells growing on carbon sources other than glucose.

Double sugar-tyrosine medium improves O-1 phage Salmonella screening.

A modification of the procedure for O-1 phage Salmonella screening is presented. The novel method is based on the use of two media, i.e., a new medium (double sugar-tyrosine [DST]), which permits the combination of adonitol and sucrose fermentation and tyrosine clearing tests, and the previously described o-nitrophenyl-beta-D-galactopyranoside urease indole medium. In comparative trials, the new procedure and the conventional one were used to screen for Salmonella isolates from 553 lactose-negative strains of members of the family Enterobacteriaceae. The O-1 phage test, performed on DST medium, recognized the same number of phage-susceptible Salmonella strains as did the standardized method; however, it permitted the correct identification of a greater number of phage-resistant strains for discard (95.6 versus 85.3%). In particular, DST medium presented a higher efficacy than triple sugar iron agar (which is the corresponding medium in the reference procedure) in correctly identifying phage-negative cultures for discard (69.1 versus 28.5%).

T-mod pathway, a reduced sequence for identification of gram-negative urinary tract pathogens.

In this paper, we describe a reduced sequence of identification that includes T-mod medium, a selective and differential isolation medium which allows accurate presumptive identification of the most common gram-negative bacteria encountered in urine samples. The present study, performed on bacteria isolated from 1,762 independent urine samples, has shown that a few selected tests (lysine and ornithine decarboxylase, urease and trehalose fermentation tests) improve the identification accuracy of T-mod, making it possible both to identify the less frequent species and to prevent some misidentifications of Klebsiella pneumoniae and Proteus mirabilis. The proposed work flow agreed with conventional identification protocols to a 99.3% extent and allowed identification of 87.4% of the isolates directly from the primary plate, 11.4% after 1 to 3 additional tests, and 1.2% after an identification gallery.

New plate medium for screening and presumptive identification of gram-negative urinary tract pathogens.

A new selective, differential plating medium to screen the common gram-negative urinary tract pathogens is described. The medium combines adonitol fermentation, phenylalanine deaminase, and beta-glucuronidase tests and allows the indole and cytochrome oxidase tests to be performed directly from the plates. High-level agreement with individual conventional tests was recorded in comparative studies with 504 cultures of gram-negative rods. There was 100% agreement, except for the Providencia spp. indole spot test (61.6% agreement). Adonitol fermentation by Providencia species could not be determined. Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa were identified with a high efficiency (100, 85.7, 83.5, and 100% agreement, respectively) without further testing. There was 96% overall agreement for the 267 infected urine samples tested.

Unusual behaviour of Klebsiella rhinoscleromatis strains on API 20E strips.

Seven Klebsiella rhinoscleromatis standard cultures and two wild isolates were examined for their responses to Api 20E (API System, S.A.) strips. Several strains yield incostant results for arabinose fermentation test in Api strips and, when positive, they were not identified. The arabinose positive test indeed, led to the numerical profiles 0004773 (not mentioned in the analytical catalogue), or 0004553 (two strains) corresponding to a Klebsiella ozaenae identification. The mathematical analysis of the biochemical results confirmed the identity of the strains as K. rhinoscleromatis.

[A new diagnostic scheme for the identification of bacterial species belonging to the Enterobacteriaceae family]. / Utilizzazione di un nuovo schema diagnostico per l'identificazione di specie di germi appartenenti alla famiglia delle Enterobacteriaceae.

A new diagnostic two-steps scheme for the species identification of enterobacteria was employed with 703 strains. The diagnoses were compared with those obtained by employing Api 20 E and Enterotube II. On the basis of the reported results this new scheme is shown to be reliable (99.71% right diagnosis) and easy to perform.

[Up-to-date diagnostic method for the diagnosis of environmental species of the Enterobacteriaceae family]. / Schema diagnostico aggiornato per la diagnosi di specie nell'ambito della famiglia delle Enterobacteriaceae.

The Authors propose a new two-steps key for the identification of the species belonging to the Enterobacteriaceae Family. This key can be employed both with standard tube methods and most commercial kits. The proposed method is a simple, easy and rapid one; moreover it considers each genus and species of Enterobacteriaceae Family, associated with human pathology, which has been defined within the month May, 1984.