Lucia Cannova

Microbial environmental contamination in Italian dental clinics: A multicenter study yielding recommendations for standardized sampling methods and threshold values.

A microbiological environmental investigation was carried out in ten dental clinics in Italy. Microbial contamination of water, air and surfaces was assessed in each clinic during the five working days, for one week per month, for a three-month period. Water and surfaces were sampled before and after clinical activity; air was sampled before, after, and during clinical activity. A wide variation was found in microbial environmental contamination, both within the participating clinics and for the different sampling times. Before clinical activity, microbial water contamination in tap water reached 51,200cfu/mL (colony forming units per milliliter), and that in Dental Unit Water Systems (DUWSs) reached 872,000cfu/mL. After clinical activity, there was a significant decrease in the Total Viable Count (TVC) in tap water and in DUWSs. Pseudomonas aeruginosa was found in 2.38% (7/294) of tap water samples and in 20.06% (59/294) of DUWS samples; Legionella spp. was found in 29.96% (89/297) of tap water samples and 15.82% (47/297) of DUWS samples, with no significant difference between pre- and post-clinical activity. Microbial air contamination was highest during dental treatments, and decreased significantly at the end of the working activity (p<0.05). The microbial buildup on surfaces increased significantly during the working hours. This study provides data for the establishment of standardized sampling methods, and threshold values for contamination monitoring in dentistry. Some very critical situations have been observed which require urgent intervention. Furthermore, the study emphasizes the need for research aimed at defining effective managing strategies for dental clinics.

Drug resistances in salmonella isolates from animal foods, Italy 1998-2000

We investigated the distribution of serotypes and patterns of drug resistance of 206 strains of salmonella isolated in southern Italy in the years 1998-2000 from raw food of animal origin, faeces of food animals and animal feed. To improve knowledge of mobile genetic elements carrying the resistance genes, some molecular features were also investigated within isolates resistant to three or more antibiotics. A high proportion of isolates, 52.2% and 37.7%, respectively, belonging to both Typhimurium and other serotypes of animal origin, proved to be multidrug resistant. The DT104 complex specific multidrug pattern of resistance was quite infrequent among isolates other than Typhimurium, but resistances to nalidixic acid and kanamycin were more frequent within these last ones (36.9% vs. 11.4% and 56.5% vs. 2.2%, respectively). Class I integrons were detected in isolates of Typhimurium and seven different serotypes. The relevance of food animal environment as a drug resistance reservoir and animal food as a potential resistance gene vehicle between the farm and human ecological niches is confirmed by our findings.

Influenza vaccination among healthcare workers and absenteeism from work due to influenza-like illness in a teaching hospital in Palermo

Background : Annual flu vaccination of healthcare workers (HCWs) is recommended worldwide as the best way to prevent influenza and to avoid its transmission. However, in several European Countries, vaccination rate among HCWs is still less than 25%. The aim of this study was to determine the HCW vaccination coverage during a three year period in a large University Hospital, identifying socio demographic and occupational variables involved in the decision to accept influenza vaccination. Moreover, for the 2007-2008 season, we also assessed the effectiveness of influenza vaccination in reducing influenza-related absenteeism. Methods : During three consecutive influenza seasons (from 2005-2006 to 2007-2008), a cross-sectional study was carried out on all HCWs employed in the “Azienda Ospedaliera Universitaria Policlinico” (AOUP) of Palermo (Italy). Socio-demographic and occupational data of HCWs were collected from administrative hospital personnel records and included gender, age, birthplace, residence, profession and the workplace unit. In addition, during the 2007-2008 season, a retrospective study was conducted to evaluate absence from work due to influenza–like illness (ILI) in vaccinated versus unvaccinated personnel. Results : A total of 7,848 HCW-years were observed and 881 vaccines were administered during the study period. Vaccination rate declined from 14.7% in 2005-2006 to 8.2% in 2007-2008 (Chi-square for trend=53.6, p<0.001). Coverage was generally higher among older and male HCWs whereas nurses and workers in surgical areas had lower vaccination rates. In the 2007-2008 season, absenteeism due to ILI in the vaccinated group was significantly less common than unvaccinated HCWs (3.3% vs 7.1%; p=0.04). Conclusions : Our experience encourages flu vaccination of HCWs and accentuates the importance of annual influenza vaccination programs for healthcare personnel.

Serological and molecular identification of Legionella spp. isolated from water and surrounding air samples in Italian healthcare facilities

BACKGROUND Legionella is an intracellular microorganism living in natural and artificial aquatic environments. Although its transmission to humans is linked to the inhalation of contaminated aerosols, there is no validated air sampling method for the control and prevention of the disease. The aim of the present study was to provide more information on the distribution of Legionella spp. in indoor environments and to determine whether the same Legionella strains are isolated from air and water samples. METHODS Ten healthcare facilities located in seven regions of Italy were enrolled. The serological typing of Legionella spp. from water samples and the surrounding air by active and passive sampling was assessed using polyvalent and monovalent antisera. Subsequently, the strains identified as Legionella pneumophila (Lpn) underwent molecular typing by sequence-based typing (SBT) using seven genes (flaA, pilE, asd, mip, mompS, proA, and neuA). The allelic profile number was assigned using the European Working Group for Legionella Infections-SBT database. RESULTS Lpn serogroup 6 was the most prevalent serogroup; it was found simultaneously in the air and water samples of three different healthcare facilities. In the remaining seven hospitals, Lpn serogroups 1, 6, 7, 9, and 12 were isolated exclusively from water samples. The molecular investigation showed that Lpn strains in the water and air samples of each positive healthcare facility had the same allelic profile. Strains, identified as sequence types (STs) 728 and ST 1638+ST 1324, were isolated in two respective healthcare facilities, and a new strain, identified as ST 1989, was obtained in one healthcare facility. CONCLUSION The application of the SBT method allowed to verify the homology among Legionella strains from water samples and the surrounding air. The results showed that the same Lpn strains were present in the air and water samples, and a new Legionella strain was identified.

Analytical Performance Issues

Contaminated hospital surfaces have been demonstrated to be an important environmental reservoir of microorganisms that can increase the risk of nosocomial infection in exposed patients. As a consequence, cleaning and disinfecting hospital environments play an important role among strategies for preventing healthcare-associated colonization and infections. The aim of the present study was to evaluate whether adenosine triphosphate (ATP) presence, measured by bioluminescence methods, can predict microbiological contamination of hospital surfaces. The study was carried out between September and December 2012 at the University Hospital “P. Giaccone” of Palermo. A total of 193 randomly selected surfaces (tables, lockers, furnishings) were sampled and analyzed in order to assess ATP levels (expressed as relative light units or RLU) and aerobic colony count (ACC) or presence of S. aureus. ACC had median values of 1.85 cfu/cm2 (interquartile range = 4.16) whereas ATP median was 44.6 RLU/cm2 (interquartile range = 92.3). Overall, 85 (44.0%) surfaces exceeded the established microbial benchmark: 73 (37.8%) exceeded the 2.5 cfu/cm2 ACC standard, 5 (2.6%) surfaces were positive for S. aureus and 7 (3.6%) showed both the presence of S. aureus and an ACC of more than 2.5 cfu/cm2. ACC and bioluminescence showed significant differences in the different surface sites (p < 0.001). A significant correlation was found between ACC and RLU values (p-value < 0.001; R2 = 0.29) and increasing RLU values were significantly associated with a higher risk of failing the benchmark (p < 0.001). Our data suggest that bioluminescence could help in measuring hygienic quality of hospital surfaces using a quick and sensitive test that can be an useful proxy of microbial contamination; however, further analysis will be necessary to assess the cost-efficacy of this methodology before requiring incorporation in hospital procedures.Contaminated hospital surfaces have been demonstrated to be an important environmental reservoir of microorganisms that can increase the risk of nosocomial infection in exposed patients. As a consequence, cleaning and disinfecting hospital environments play an important role among strategies for preventing healthcare-associated colonization and infections. The aim of the present study was to evaluate whether adenosine triphosphate (ATP) presence, measured by bioluminescence methods, can predict microbiological contamination of hospital surfaces. The study was carried out between September and December 2012 at the University Hospital “P. Giaccone” of Palermo. A total of 193 randomly selected surfaces (tables, lockers, furnishings) were sampled and analyzed in order to assess ATP levels (expressed as relative light units or RLU) and aerobic colony count (ACC) or presence of S. aureus. ACC had median values of 1.85 cfu/cm2(interquartile range = 4.16) whereas ATP median was 44.6 RLU/cm2(interquartile range = 92.3). Overall, 85 (44.0%) surfaces exceeded the established microbial benchmark: 73 (37.8%) exceeded the 2.5 cfu/cm2ACC standard, 5 (2.6%) surfaces were positive for S. aureus and 7 (3.6%) showed both the presence of S. aureus and an ACC of more than 2.5 cfu/cm2. ACC and bioluminescence showed significant differences in the different surface sites (p < 0.001). A significant correlation was found between ACC and RLU values (p-value < 0.001; R2= 0.29) and increasing RLU values were significantly associated with a higher risk of failing the benchmark (p < 0.001). Our data suggest that bioluminescence could help in measuring hygienic quality of hospital surfaces using a quick and sensitive test that can be an useful proxy of microbial contamination; however, further analysis will be necessary to assess the cost-efficacy of this methodology before requiring incorporation in hospital procedures.

Salmonella serovars identified at the Centre for Enterobacteriaceae of Palermo over the 5-year period 1983-87.

Salmonellosis is become an increasing public health problem in many countries. Serotyping and assessment of antibiotic resistance are useful tools, which assist in understanding the epidemiology of Salmonella infections. In this respect, the Centre of Enterobacteriaceae of Southern Italy provides helpful information on the changing pattern of Salmonella serovars in this geographic area.This paper reports the distribution of serovars and their antibiotic susceptibility in the years 1983–1987. In particular, because of their peculiar trends during this 5-year period, epidemiological features of Mbandaka, Corvallis, Dublin, Infantis and Wien serovars are described.