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In a bacterium like Helicobacter pylori, which is characterized by a recombinant population structure, the associated presence of genes encoding virulence factors might be considered an expression of a selective advantage conferred to strains with certain genotypes and, therefore, a potentially useful tool for predicting the clinical outcome of infections. However, differences in the geographical and ethnic prevalence of the H. pylori virulence-associated genotypes can affect their clinical predictive value and need to be considered in advance. In this study we carried out such an evaluation in a group of patients living in Sicily, the largest and most populous island in the Mediterranean Sea. cagA, vacA, babA2, hopQ, oipA, sabA, and hopZ were the H. pylori virulence-associated genes assayed; their presence, expression status or allelic homologs were detected in H. pylori DNA samples and/or isolated strains, obtained by gastric biopsy from 90 Sicilian patients with chronic gastritis, inactive (n = 37), active (n = 26), or active with peptic ulcer (n = 27). Genotypes cagA (+), vacAs1, vacAm1, babA2 (+), and hopQ I, I/II were identified in 51.8, 80.4, 35.2, 47.3, and 67.7% of the different samples respectively. Only these genotypes were associated with each other and with the active form of chronic gastritis, irrespective of the presence of a peptic ulcer. In our isolates their prevalence was more similar to values observed in the north of Italy and France than to those observed in Spain or other Mediterranean countries that are closer and climatically more similar to western Sicily.

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Despite recent developments in microbiological biomolecular techniques, blood culture remains the most practical and reliable method in the diagnosis of bloodstream infections and one of the most important tools in the clinical microbiology laboratory, taking into account the role played by systemic infections as a major cause of mortality and morbidity, especially within the hospital environment. Various continuously monitoring blood culture systems are extensively used in order to increase the rapidity of isolation and identification of microorganisms in blood samples, and paired aerobic and anaerobic blood culture bottles are commonly used in order to obtain better overall recovery of microorganisms, as well as the recovery of specific types of bacteria. The traditional aerobic and anaerobic bacteriological media also detect episodes of candidemia, although the sensitivity in this case is estimated to be only 50% (12). The efficiency of yeast detection in blood samples can be increased by terminal subcultures, but the practice is time-consuming and the risk of underestimating yeast infections remains high. This is unacceptable if we take into account the expanding role of yeasts as agents of nosocomial infections, particularly in intensive-care units (ICUs) (4, 18, 23), and candidemia-associated mortality (40%), the highest of all hospital bloodstream infections (4). In order to facilitate faster and more efficient isolation of fungi from blood, the Bactec automated blood culture system (Becton Dickinson Diagnostic Systems, Sparks, MD) has media specifically formulated for this purpose. In addition to the traditional aerobicanaerobic bacteriological set, their use has been recommended when blood culture is required for patients at risk of fungal infections (7, 16) and when a concomitant bloodstream bacterial infection is suspected of inhibiting yeast detection (16).Nevertheless, fungal media are not routinely employed by many hospitals, as they require additional blood from patients, an increased amount of incubator space, and the additional costs of processing and purchasing bottles (10). Moreover, even the routine use of anaerobic bacteriological bottles in blood culture has been (21), and still is (13), a subject of discussion because of the reportedly declining rates of anaerobic bloodstream infections (2) and the possibility of recognizing them clinically and treating affected patients empirically for such infections (17,19,22).

Serological typing of P. aeruginosa is the most simple and reliable procedure recommended for "in-house" investigations and for studies of suspected outbreaks of infection by this microorganism. It is also a useful procedure in order to know serotype prevalence in a definite geographical area and to obtain indications about the more appropriate composition of polyvalent anti-Pseudomonas vaccines. In the present report, we describe the relatively high frequency of isolation of serogroup 12 from patients in Palermo, Italy. Serogroup 12 is very rare in north-Europe and in the USA, and, as a consequence, it is not included in some vaccine preparations. In Palermo, strains belonging to this serogroup, resistant to a large number of antibiotics, were on the contrary isolated, during more than six years, in different hospitals and from three out-patients. In a Burns Unit, they were in particular responsible for extensive and life-threatening outbreaks.

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In 1988 in Palermo, Italy, the prevalence of antibodies to hepatitis A virus (anti-HAV) in a sample of 490 children 6-13 years old was 10.6%; it increased from 6.3% among children 6-10 years old to 14.7% in children 11-13 years old (P less than 0.01). Compared with findings from a survey conducted in 1978 in the same area, the results of the present study show a significant (P less than 0.01) reduction in the anti-HAV prevalence in both age groups. Anti-HAV prevalence was inversely related to the father's years of education and positively related to the family size. Children of fathers with less than 6 years of schooling had a 3.2-fold risk (C.I. 95% = 1.3-8.1), and children with five or more members in their households had a 2.7-fold risk (C.I. 95% = 1.1-6.4) of previous exposure to hepatitis A virus (HAV) infection. Our findings indicate that exposure of children in Palermo to HAV is decreasing significantly, probably because of improvements in socio-economic conditions during recent years; however socio-demographic factors appear to be important determinants of infection.