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e. leoni, g. de luca, p.p. legnani, r. sacchetti, s. stampi and f. zanetti. 2004.An evaluation was made of the prevalence ofLegionellaspecies in hot water distribution systems in the city of Bologna (Italy) and their possible association with bacterial contamination (total counts and Pseudomonadaceae) and the chemical characteristics of the water (pH, Ca, Mg, Fe, Mn, Cu, Zn and Total Organic Carbon, TOC).A total of 137 hot water samples were analysed: 59 from the same number of private apartments, 46 from 11 hotels and 32 from five hospitals, all using the same water supply.Legionellaspecies were detected in 40·0% of the distribution systems,L. pneumophilain 33·3%. The highest colonization was found in the hot water systems of hospitals (93·7% of samples positive forL. pneumophila, geometric mean: 2·4 × 103 CFU l−1), followed by the hotels (60·9%, geometric mean: 127·3 CFU l−1) and the apartments with centralized heating (41·9%, geometric mean: 30·5 CFU l−1). The apartments with independent heating systems showed a lower level of colonization (3·6% forLegionellaspecies), with no evidence ofL. pneumophila. Correlation analysis suggests that copper exerts an inhibiting action, while the TOC tends to favour the development ofL. pneumophila. No statistically significant association was seen with Pseudomonadaceae, which were found at lower water temperatures than legionellae and in individual distribution points rather than in the whole network.The water recirculation system used by centralized boilers enhances the spreading of legionellae throughout the whole network, both in terms of the number of colonized sites and in terms of CFU count.Differences inLegionellacolonization between types of buildings are not due to a variation in water supply but to other factors. Besides the importance of water recirculation, the study demonstrates the inhibiting action of copper and the favourable action of TOC on the development ofL. pneumophila. [ABSTRACT FROM AUTHOR]

Aims Epidemiology of melioidosis is poorly understood because its occurrence is influenced by complex interaction of environmental, climatic, physicochemical and host factors. We investigated the potential risk factors for the exposure to Burkholderia pseudomallei in small ruminants' farms in Peninsular Malaysia. Methods and Results Melioidosis-positive ( n = 33) and negative ( n = 27) farms were selected and visited for interviews and environmental samples collection. The characteristics and putative disease risk factors were compared between the case and the control farms using Chi-square test and logistic regression analysis. The multivariable logistic regression analysis showed that the odds of melioidosis were significantly higher in farms that had bush clearing around farms (odds ratio ( OR) = 6·61, 95% confidence interval ( CI) = 1·12-38·84, P = 0·037), in farms with B. pseudomallei present in the soil ( OR = 6·23, 95% CI = 1·03-37·68, P = 0·046), in farms that have other animal species present ( OR = 7·96, 95% CI = 1·14-55·99, P = 0·037) and in farms that had flooding or waterlogging conditions ( OR = 11·95, 95% CI = 1·39-102·6, P = 0·024) when compared to the odds of the disease in farms that did not have the above conditions. The odds of the disease in farms that treated their soils with lime were significantly lower ( OR = 0·028, 95% CI = 0·003-0·29, P = 0·003) compared to the odds in those that did not. Conclusions The risk factors for the exposure to B. pseudomallei highlighted above may have contributed to the occurrence of melioidosis in animals in the study farms. Significance and Impact of the Study Information from the study may be helpful in planning control measures against melioidosis and have improved understanding of the epidemiology of the disease in livestock farms. [ABSTRACT FROM AUTHOR]

Aims This study aimed to investigate the prevalence of Simkania negevensis in the chlorinated water of spa swimming pools and domestic network systems. Methods and Results A total of 10 and 36 samples were collected from two domestic water supplies and four spa facilities, respectively. Simkania negevensis was isolated in Acanthamoeba castellanii monolayers and detected by Gimenez staining and immunofluorescence test. Simkania negevensis DNA, extracted from the positive samples, was confirmed by a nested PCR assay followed by sequencing. Simkania negevensis was detected in 41·3% of samples (domestic water: 50%; untreated spa supply water: 25%; chlorinated spa pool water: 42·9%) from all the examined water systems in successive samplings performed in 1 year. The presence of S. negevensis was not correlated with the counts of Heterotrophic Bacteria and Pseudomonas aeruginosa. Unlike Legionella spp., which were never isolated from the swimming-pool water samples, S. negevensis was also detected in chlorinated spa water. Conclusions This investigation shows that Simkania is widespread in natural and man-made aquatic environments, which may represent possible sources of infection: in the swimming pools, in particular, the aerosol generated by the water movement could increase the risk of inhalation of infected particles. Significance and Impact of the Study This study represents the first evidence of the presence of S. negevensis in spa pool water. Sero-epidemiological surveys on spa users could help to clarify its transmission in this environment. [ABSTRACT FROM AUTHOR]

Aims The objective of this study was to evaluate the bactericidal efficacy of hydrogen peroxide administered in combination with 17 mineral and organic acids authorized for use in the food industry. Methods and Results The assays were performed on a 96-well microplate using a microdilution technique based on the checkerboard titration method. The six selected strains were reference strains and strains representative of contaminating bacteria in the food industry. Each synergistic hydrogen peroxide/acid combination found after 5-min contact time at 20°C in distilled water was then tested in conditions simulating four different use conditions. Thirty-two combinations were synergistic in distilled water; twenty-five of these remained synergistic with one or more of the four mineral and organic interfering substances selected. Hydrogen peroxide/formic acid combination was synergistic for all six bacterial strains in distilled water and remained synergistic with interfering substances. Six other combinations maintained their synergistic effect in the presence of an organic load but only for one or two bacterial strains. Conclusions Synergistic combinations of disinfectants were revealed, among them the promising hydrogen peroxide/formic acid combination. Significance and Impact of the Study A rapid screening method was proposed and used to reveal the synergistic potential of disinfectant and/or sanitizer combinations. [ABSTRACT FROM AUTHOR]

Aims: This study was designed to define the extent of water contamination by Legionella pneumophila of certain Italian hotels and to compare quantitative real-time PCR with the conventional culture method. Methods and Results: Nineteen Italian hotels of different sizes were investigated. In each hotel three hot water samples (boiler, room showers, recycling) and one cold water sample (inlet) were collected. Physico-chemical parameters were also analysed. Legionella pneumophila was detected in 42% and 74% of the hotels investigated by the culture method and by real-time PCR, respectively. In 21% of samples analysed by the culture method, a concentration of >104 CFU l−1 was found, and Leg. pneumophila serogroup 1 was isolated from 10·5% of the hotels. The presence of Leg. pneumophila was significantly influenced by water sample temperature, while no association with water hardness or residual-free chlorine was found. Conclusions: This study showed a high percentage of buildings colonized by Leg. pneumophila. Moreover, real-time PCR proved to be sensitive enough to detect lower levels of contamination than the culture method. Significance and Impact of the Study: This study indicates that the Italian hotels represent a possible source of risk for Legionnaires’ disease and confirms the sensitivity of the molecular method. To our knowledge, this is the first report to demonstrate Legionella contamination in Italian hotels using real-time PCR and culture methods. [ABSTRACT FROM AUTHOR]

Aim: To investigate the aerobiology of the environment around mechanically ventilated broiler sheds with the aim of understanding dispersion in the surrounding environment. Methods and Results: Aerosol samples were collected weekly on four different commercial broiler farms through the cycle of 55 days from 2005 to 2007. Samples were collected inside the shed and at varying distances from the sheds. Litter and dust from within the shed were also examined. Members of the genera Staphylococcus (and to a lesser extent Corynebacterium) dominated (106 CFU m−3) in the outside air at 20 m from the fan and were shown to decrease with distance. At distances of around 400 m, the levels of staphylococci/coryneforms returned to levels typical of those present before the placement of chickens. Escherichia coli levels were low (maximum 100 CFU m−3) at 20 m. Fungi were present at uniform levels across the broiler cycle. Conclusions: Staphylococci are the dominant organisms present in the air around mechanically ventilated broiler sheds and have the potential to act as an airborne ‘marker organism’. Significant Impact of the Study: The outcomes of this study suggest that the impact of aerosols emitted from broiler sheds could be monitored and managed by examining the levels of staphylococci/coryneforms. [ABSTRACT FROM AUTHOR]

Aims: To study the diversity and virulence of Listeria monocytogenes isolated from sludge. Methods and Results: A total of 60 isolates of L.  monocytogenes from sludge were characterized by serotyping, PFGE typing and using in vitro and in vivo virulence assays. The PFGE patterns were compared with those of food and human isolates to determine whether specific group clones are associated with environmental samples. The 60 isolates gave 44 different combined ApaI/ AscI PFGE patterns. The PFGE patterns of most isolates were similar or very similar to those of epidemic isolates. The majority (93%) of isolates were found to be virulent by plaque-forming assay and by mouse virulence assay. Conclusions: Our findings suggest that L. monocytogenes strains found in non-sanitized sludge are virulent and represent a potential health hazard. Although no case of listeriosis related to sludge spread onto agricultural land has been reported, particular attention to this pathogen is needed. Significance and Impact of the study: This is the first study dealing with the characterization of L. monocytogenes isolates from non-sanitized sludge samples by molecular typing methods and in vitro and in vivo virulence assays. Our findings provide relevant information for evaluating the health risks associated with spreading sludge onto agricultural land. [ABSTRACT FROM AUTHOR]

Current models to study Legionella pathogenesis include the use of primary macrophages and monocyte cell lines, various free-living protozoan species and murine models of pneumonia. However, there are very few studies of Legionella spp. pathogenesis aimed at associating the role of biofilm colonization and parasitization of biofilm microbiota and release of virulent bacterial cell/vacuoles in drinking water distribution systems. Moreover, the implications of these environmental niches for drinking water exposure to pathogenic legionellae are poorly understood. This review summarizes the known mechanisms of Legionella spp. proliferation within Acanthamoeba and mammalian cells and advocates the use of the amoeba model to study Legionella pathogenicity because of their close association with Legionella spp. in the aquatic environment. The putative role of biofilms and amoebae in the proliferation, development and dissemination of potentially pathogenic Legionella spp. is also discussed. Elucidating the mechanisms of Legionella pathogenicity development in our drinking water systems will aid in elimination strategies and procedural designs for drinking water systems and in controlling exposure to Legionella spp. and similar pathogens. [ABSTRACT FROM AUTHOR]

Dental chair units (DCUs) contain integrated systems that provide the instruments and services for a wide range of dental procedures. DCUs use water to cool and irrigate DCU-supplied instruments and tooth surfaces during dental treatment. Water is supplied to these instruments by a network of interconnected narrow-bore (2–3 mm) plastic tubes called dental unit waterlines (DUWLs). Many studies over the last 40 years demonstrated that DUWL output water is often contaminated with high densities of micro-organisms, predominantly Gram-negative aerobic heterotropic environmental bacteria, including Legionella and Pseudomonas species. Untreated DUWLs host biofilms that permit micro-organisms to multiply and disperse through the water network and which are aerosolized by DCU instrument use, thus exposing patients and staff to these micro-organisms, to fragments of biofilm and bacterial endotoxins. This review concentrates on how practical developments and innovations in specific areas can contribute to effective DUWL biofilm control. These include the use of effective DUWL treatment agents, improvements to DCU supply water quality, DCU design changes, development of automated DUWL treatment procedures that are effective at controlling biofilm in the long-term and require minimal human intervention, are safe for patients and staff, and which do not cause deterioration of DCU components following prolonged use. [ABSTRACT FROM AUTHOR]

Aims: To determine Legionella pollution prevalence, describe the amount of Legionellae with respect to temperature in Shanghai cooling tower water (CTWs) in various types of public sites. Methods and Results: Six urban districts were selected as the study fields, adopting multiple-phase sampling methods. Routine culture was used to identify Legionellae. Of the samples, 58·9% (189/321) were observed to be positive, 19·9% were isolated over 100 CFU ml−1. Legionella pneumophila serogroup 1 was the most frequently isolated species (155/189, 82·0%), followed by Leg. micdadei that was at the second place (44/189, 23·3%). The mean CFU ml−1 of Legionellae in CTWs reached its peak from July to September. Over all 15·4% of the samples exceeding 100 CFU ml−1 were observed in a hospital setting. Conclusions: The prevalence of Legionella pollution in CTWs, especially in CTWs of subway stations and hospitals, is worrying, and the positive rate and CFU ml−1 of Legionellae in CTWs have a close relationship with air temperature. Significance and Impact of the Study: The study demonstrates pollution prevalence rates in different types of sites and various seasons, and provides a proportion of different serogroups of Legionellae. It illuminates an urgent need for dealing with the potential risk of legionellosis in Shanghai, through improved control and prevention strategies. [ABSTRACT FROM AUTHOR]

Aims: To assess chlorine susceptibility of Legionella pneumophila grown from two amoebic hosts, Acanthamoeba castellanii and Hartmannella vermiformis. Methods and Results: After being released from amoebae, Leg. pneumophila were chlorinated at 2 and 5 mg l−1 for 5 min–24 h. Bacterial culturability and cytoplasmic membrane deterioration were quantified by culture assay on BCYEα agar and BacLight stains coupled with a fluorescent microscope, respectively. Chlorination reduced the culturability of Leg. pneumophila by 2·93–4·59 log CFU ml−1 and damaged cellular membrane by 53·8–99·2%. Moreover, cells released from H. vermiformis exhibited significantly lower degrees in culturability reduction ( P = 0·0008) and membrane deterioration ( P < 0·0001) when compared with those from A. castellanii. The amoebic genus is the most significant parameter affecting cytoplasmic membrane integrity of chlorinated Legionella ( P < 0·0001), followed by free chlorine concentration ( P = 0·042). Conclusions: Legionella pneumophila replicated from H. vermiformis possess greater chlorine resistance than the cells from A. castellanii. Significance and Impact of the Study: This study shows the heterogeneity of amoebae-grown Leg. pneumophila in chlorine susceptibility, which should be considered in the control of legionellae proliferation, particularly in the systems where H. vermiformis is dominant, e.g. hot water plumbing. [ABSTRACT FROM AUTHOR]

Aims: To investigate the prevalence of culturable and nonculturable Legionella species in hot water systems of public buildings in Japan and assess the risk factors associated with Legionella contamination in hot water systems. Methods and Results: Legionella species were detected by conventional culture and molecular methods in 130 water samples collected from 40 buildings. A total of 26 (20·0%) water samples from 17 (42·5%) buildings were positive by culture, qualitative PCR or both methods: Legionella pneumophila and Leg. anisa were detected in four samples by a culture method, whereas 23 samples were positive by qualitative PCR, with the presence of various Legionella species confirmed by sequencing. Of these 23 samples, bacterial counts were quantifiable in 21 by real-time PCR (from 1·7 × 105 to 2·6 × 1011 cells per litre). Phylogenetic analysis of amplified partial 16S rRNA gene showed close relations to various species of Legionella, including Leg. anisa and Leg. micdadei, all of which have been associated with respiratory diseases or increased antibody titres in human sera. Assessment of risk factors showed that turbidity, free chlorine concentration, iron concentration and heterotrophic plate count (HPC) were significantly associated with Legionella contamination ( P < 0·05). Conclusions: Contamination of hot water systems of public buildings with culturable and nonculturable Legionella species may be a potential risk factor for Legionella infection in Japan. Adequate levels of chlorine, low levels of iron and HPC are important maintenance measures in the reduction of Legionella contamination in hot water systems. Significance and Impact of the Study: More than 40% of hot water systems in the Japanese public buildings examined were contaminated by not only culturable Leg. pneumophila and Leg. anisa but also by nonculturable pathogenic species. To our knowledge, this is the first report of both culturable and nonculturable Legionella contamination in hot water systems of public buildings in Japan. [ABSTRACT FROM AUTHOR]

Aim: To determine the effect of sodium bicarbonate (SB), sodium metaperiodate (SMP) and sodium dodecyl sulfate (SDS) combination on biofilm formation and dispersal in dental unit waterline (DUWL)-associated bacteria and yeast. Methods and Results: The in vitro effect of SB, SMP and SDS alone and in combination on biofilm formation and dispersal in Pseudomonas aeruginosa, Klebsiella pneumoniae, Actinomyces naeslundii, and Candida albicans was investigated using a 96-well microtitre plate biofilm assay. The combination showed a broad-spectrum inhibitory effect on growth as well as biofilm formation of both gram-negative and gram-positive bacteria, and yeast. In addition, the SB + SMP + SDS combination was significantly more effective in dispersing biofilm than the individual compounds. The combination dispersed more than 90% of P. aeruginosa biofilm whereas the commercial products, Oxygenal 6, Sterilex Ultra, and PeraSafe showed no biofilm dispersal activity. Conclusion: The composition comprising SB, SMP, and SDS was effective in inhibiting as well as dispersing biofilms in DUWL-associated bacteria and yeast. Significance and Impact of the Study: This study shows that a composition comprising environmentally friendly and biologically safe compounds such as SB, SMP, and SDS has a potential application in reducing DUWL-associated acquired infections in dental clinics. [ABSTRACT FROM AUTHOR]

Aims: To study the persistence of Legionella over time in different disinfected facilities and analysing whether failures in bacterial eradication could be the result of a decrease in the susceptibility of the persistent strains to subsequent treatments. Methods and Results: A long-term environmental surveillance was carried out in three different facilities associated with cases of Legionnaires’ disease (a hospital, a fishing boat and a hotel). Despite several hyperchlorination episodes, amplified fragment length polymorphism, pulsed field gel electrophoresis- SfiI and arbitrarily primed polymerase chain reaction methods demonstrated that a specific clone of L. pneumophila serogroup 1 was able to survive for 17, 5 and 10 years in the hospital, fishing boat and the hotel, respectively. Isolates from different years from the same facility showed similar minimal inhibitory concentration and minimal bactericidal concentration values against eight different disinfectants. Conclusions: Hyperchlorination over long periods of time did not prevent the persistence of L. pneumophila. The lack of effectiveness did not appear to be the result of a decreased susceptibility of Legionella to chlorine. Hyperchlorination did not modify in vitro susceptibility of Legionella to other disinfectants to which the bacteria had not previously been exposed. Significance and Impact of the Study: Persistent Legionella in treated installations remain sensitive to disinfectants; hence, new strategies of treatment, different from hyperchlorination, should be developed to achieve bacterial eradication. [ABSTRACT FROM AUTHOR]

Aim: The current study investigated the prevalence and molecular relatedness between Escherichia coli O157:H7 isolated from water, meat and meat products and vegetables and from stools of confirmed and non-confirmed Human Immune Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) patients with diarrhoea. Methods and Results: Culture-based and polymerase chain reaction techniques were used to identify E. coli O157:H7. Thirty-five per cent of meat products, 25·5% of water, 21·7% of vegetables as well as 56·5% and 43·5% of stools of confirmed and non-confirmed HIV/AIDS patients, respectively, were presumptively positive with E. coli O157. Molecular results indicated that 10·3%, 8·6% and 7·8% of the vegetables, water and meat products examined carried E. coli O157:H7, which had homologous fliC H7, rfbE O157 and eaeA genetic loci to the genes of some E. coli O157:H7 isolated from 12·2% and 8·8% of the stools of confirmed and non-confirmed HIV/AIDS patients, respectively. Conclusions: Water, meat and meat products and vegetables are potential sources of E. coli O157:H7 that are potentially capable of causing diarrhoea in humans especially HIV/AIDS patients. Significance and Impact of the Study: Great care should be exercised to ensure that water and foods consumed by HIV/AIDS patients are safe, as contaminated water and foods can cause secondary infections in these patients. [ABSTRACT FROM AUTHOR]

Aims: To determine if contamination levels of Escherichia coli O157 and generic E. coli in retail-minced meat products are greater in rural shops compared with urban shops in Grampian, NE Scotland. We also investigated whether meat from supermarkets and meat from local butcher shops had a similar bacteriological quality. Methods and Results: Minced beef and minced lamb were tested from November 2004 to August 2006. Escheichia coli O157 was found at low levels in four samples out of 530 tested samples (0·75%). Generic E. coli were present in 11% of the samples tested, of which 67% came from supermarkets. We observed no significant difference in the prevalence of generic E. coli between rural and urban areas. Conclusions: Low levels of contamination with E. coli O157 and generic E. coli in retail meat suggest that meat is not a major route of infection in NE Scotland. Significance and Impact of the Study: The study does not suggest that the high incidence of E. coli O157 human infection in the rural areas of Grampian is because of meat consumption – this provides further evidence of contact with animals or water being the routes of infection. Hence, risk mitigation should be focussed more on environmental pathways of infection. [ABSTRACT FROM AUTHOR]

Aims: To investigate the presence of viable but non-culturable Listeria monocytogenes during survival on parsley leaves under low relative humidity (RH) and to evaluate the ability of L. monocytogenes to recover from VBNC to culturable state under satured humidity. Methods and Results: Under low RH (47–69%) on parsley leaves, the initial number of L. monocytogenes populations counted on non selective media (109 L. monocytogenes per leaf on TSA) was reduced by 6 log10 scales in 15 days, whereas number of viable L. monocytogenes counted under the microscope was reduced by 3–4 log10 scales, indicating the presence of VBNC cells. This was demonstrated on three L. monocytogenes strains (EGDe, Bug 1995 and LmP60). Changing from low to 100% RH permitted an increase of the culturable counts of L. monocytogenes and this growth was observed only when residual culturable cells were present. Moreover, VBNC L. monocytogenes inoculated on parsley leaves did not become culturable after incubation under 100% RH. Conclusions: Dry conditions induced VBNC L. monocytogenes on parsley leaves but these VBNC were likely unable to recover culturability after transfer to satured humidity. Significance and Impact of Study: Enumeration on culture media presumably under-estimates the number of viable L. monocytogenes on fresh produce after exposure to low RH. [ABSTRACT FROM AUTHOR]

Aims: To investigate the occurrence and levels of Arcobacter spp. in pig effluent ponds and effluent-treated soil. Methods and Results: A Most Probable Number (MPN) method was developed to assess the levels of Arcobacter spp. in seven pig effluent ponds and six effluent-treated soils, immediately after effluent irrigation. Arcobacter spp. levels in the effluent ponds varied from 6·5 × 105 to 1·1 × 108 MPN 100 ml−1 and in freshly irrigated soils from 9·5 × 102 to 2·8 × 104 MPN g−1 in all piggery environments tested. Eighty-three Arcobacter isolates were subjected to an abbreviated phenotypic test scheme and examined using a multiplex polymerase chain reaction (PCR). The PCR identified 35% of these isolates as Arcobacter butzleri, 49% as Arcobacter cryaerophilus while 16% gave no band. All 13 nonreactive isolates were subjected to partial 16S rDNA sequencing and showed a high similarity (>99%) to Arcobacter cibarius. Conclusions: A. butzleri, A. cryaerophilus and A. cibarius were isolated from both piggery effluent and effluent-irrigated soil, at levels suggestive of good survival in the effluent pond. Significance and Impact of the Study: This is the first study to provide quantitative information on Arcobacter spp. levels in piggery effluent and to associate A. cibarius with pigs and piggery effluent environments. [ABSTRACT FROM AUTHOR]

Aims: To confirm the presence of viable Legionella spp. in dental unit waterlines (DUWL) using fluorescent in situ hybridization (FISH) and compare this method with culture approach and also to validate the utility of an enrichment to increase FISH sensitivity. Methods and Results: Water samples from 40 dental units were analysed. Three different techniques for detecting Legionella spp. were compared: (i) culture approach, (ii) direct FISH and (iii) FISH with a previous R2A medium enrichment (R2A/FISH). The FISH detection was confirmed by PCR. The use of the direct FISH does not improve significantly the detection of legionellae when compared with the culture. On the contrary, when R2A/FISH was performed, sensitivity was, respectively, two- and threefold higher than that with the direct FISH and culture approach. Using R2A/FISH, 63% of water samples analysed showed a contamination by legionellae. Conclusions: Legionellae detection by direct FISH and R2A/FISH in dental unit water is possible but is more rapid and more sensitive (R2A/FISH) than the culture approach. Significance and Impact of the Study: R2A/FISH showed that several pathogens present in DUWL are viable but may not be culturable. Unlike PCR, R2A/FISH is designed to detect only metabolically active cells and therefore provides more pertinent information on infectious risk. [ABSTRACT FROM AUTHOR]

Aims: To compare the sensitivities of two nested PCR assays for the detection of Legionella pneumophila to each other and to the plate counting technique (ISO 11731) in a wide range of aquatic samples. Methods and Results: The nested PCR assay with the primer set LEG 225-LEG 858 revealed 56% of the 46 analysed aquatic samples as being positive for Legionella spp., while the primer set JFP-JRP yielded 98% positive samples. The detection was confirmed by sequencing the PCR products. These results are considerably higher than the result obtained with the plate counting technique (41%), indicating the higher sensitivity of PCR-based diagnostic methods. As the PCR assay with the LEG 225-LEG 858 primer set resulted in a lower number of positive samples, it is considered not sensitive enough for aquatic samples. Similar results for the respective primer sets were obtained for the detection of the species L. pneumophila, responsible for 90% of all human Legionella infections, in the aquatic samples analysed. Both microbial community analysis by PCR-denaturing gradient gel electrophoresis and the analysis of biotic and abiotic water quality parameters revealed no relation between L. pneumophila-positive and -negative samples and the physico-chemical and bacteriological characteristics of the aquatic samples. Conclusions: The results show the additional value of the PCR assay with the JFP-JRP primer set compared with the plate counting technique, as well as its applicability in a wide range of aquatic samples. Significance and Impact of the Study: This study shows the importance of comparing different primer sets for nested PCR assays for the detection of L. pneumophila in aquatic samples, as well as the lower sensitivity of the widely accepted plate counting technique (ISO 11731). [ABSTRACT FROM AUTHOR]

a.-m. pourcher, p. morand, f. picard-bonnaud, s. billaudel, s. monpoeho, m. federighi, v. ferré and g. moguedet. 2005. To study the decrease of enteric micro-organisms including viable nematode eggs, enteroviruses, faecal indicators ( Escherichia coli and enterococci) and pathogenic bacteria ( Listeria monocytogenes, Salmonella sp. and Clostridium perfringens) of a rural sewage sludge when it is composted for 7 months in mixture with straw. Numbers of the test organisms and the physico-chemical parameters were measured on a monthly basis on the mixture, on the compost after being turned, and on the pile in three positions representing the part by which air is incoming, the bottom of the pile and the part through which air is outgoing. The lowest temperature in the pile was observed at the bottom, where it did not exceed 50°C against 66°C in the two other areas. There were no significant differences between the three areas in terms of micro-organism survival. Infectious enteroviruses were inactivated rapidly and were not found after the first turning whereas some genomes were detected until after the third turning. Escherichia coli and enterococci presented a similar survival rate and their number decreased by 4 log10 whereas Salmonella decayed at a greater rate than L. monocytogenes. The numbers of C. perfringens decreased gradually to reach a final concentration in the mature compost of about 102 CFU g−1 dry matter (d.m.), which was similar to that of the faecal indicators. The hygienic effect of sludge composting in mixture with straw results in a significant reduction of enteric micro-organisms, the concentration of the faecal indicators in the final product being <64 most probable number g−1 d.m. The concentrations of Salmonella, enteroviruses and viable nematode eggs in the final product were not detectable which is in accordance with the French legislation. The results which pointed out the different behaviour of the test micro-organisms reflect the difficulty to propose a relevant indicator of hygienization. Otherwise, they show that composting is an efficient means for hygienization of sludge of rural wastewater treatment, where the straw is available close to their place of production. [ABSTRACT FROM AUTHOR]

m. moreau, m.g.j. feuilloley, n.orange and j.-l. brisset. 2005.To compare the decontamination performances of glidarc on strains ofErwiniaof industrial interest.Cultures ofErwinia carotovora carotovora,Erwinia carotovora atrosepticaandErwinia chrysanthemitaken in stationary phase were exposed to the plasma generated by electric discharges in a gliding arc reactor prototype. The kinetics of destruction of bacteria were followed by direct platting. All bacterial strains presented a three-phase destruction kinetics leading to an apparent sterilization within 10 min. Epifluorescent observations using life/dead probes revealed the absence of viable but not cultivable resistant forms. Measurement of the physical parameters of the medium confirmed that the technique was nonthermal but that reactive species responsible for a decrease of the pH were generated. However, even after neutralization the medium did not allow bacterial growth.The results demonstrate that glidarc allows a rapid and complete destruction of planctonic strains ofErwiniaswithout formation of resistant forms.The reduction rate obtained by this technique shows the great industrial interest of glidarc for decontamination and suggests that it can be used for sterilization of industrial water effluents. [ABSTRACT FROM AUTHOR]

g. blaiotta, d. ercolini, c. pennacchia, v. fusco, a. casaburi, o. pepe and f. villani. 2004.Evaluation of the occurrence of most known staphylococcal enterotoxin (SE) genes,egc(enterotoxin gene cluster) and TSST1 (toxic shock syndrome toxin 1) gene in both coagulase-positive (CPS) and coagulase-negative (CNS) staphylococcal strains isolated from meat and dairy products.Specificity and reliability of the PCR detection methods used were ascertained by using nine reference strains ofStaphylococcus(S. aureus) harbouring SE genes (seA toseE;seG,seH,seI,seM, seJ,seN andseO) andegc(containing the following sequence of genes: seO,seM,seI,ϕ ent1,ϕ ent2,seN andseG). Of 109 wildStaphylococcusspp. strains analysed, only 11S. aureusstrains were SE and/or TSST1 PCR-positive. The last 11 strains also appeared to harbour theegc. Restriction endonuclease analysis of part of theegcof both reference and wild strains showed that different variants of theegcexist. Moreover, nucleotide sequences ofseG andseI indicate that theegcof the strain AB-8802 is characterized by the presence of variants of these enterotoxins (seGv andseIv).The occurrence of SE genes in CNS and other non-S. aureusspecies isolated from Napoli-type salami, raw water buffalo milk and natural whey cultures used for mozzarella cheese manufacturing is very rare.During this study it was shown that at least five differentegcmay exist inS. aureus. A thorough study ofegcpolymorphism should provide further insight into the phylogenetics of theegc. [ABSTRACT FROM AUTHOR]

Abstract Aim: The primary aim of this study was to determine the incidence of Campylobacter spp. on turkey, presented for processing at participating production plants located in the midwest region of the United States. Methods and Results: The two participating plants were visited on a monthly basis for a period of 1 year. Sampling of carcasses was carried out using a surface swab technique. Swabs were obtained from carcasses at two points on the production line – prechill and postchill. In addition, samples of chill water were also obtained for examination. Isolation and detection of Campylobacter was carried out using enrichment in Preston broth with recovery of the organism on blood free Campylobacter selective agar (CCDA). Isolates recovered were screened and identified using the API Campy® identification system. The study found that 34·9% of all samples tested were positive for Campylobacter spp. The overall, contamination rates observed for both plants were relatively similar (39·2% for plant A and 30·6% for plant B). Differences were observed in the incidence of Campylobacter spp. on prechill vs postchill carcasses (i.e. 40·8% prechill vs 37·6% postchill for plant A and 41·8% prechill vs 19·8% postchill for plant B). Campylobacter species most often isolated included Camp. jejuni and Camp. coli . Other species recovered were Camp. fetus fetus , Camp. upsaliensis and Camp. lari . Conclusions: The incidence of Campylobacter spp. on processed poultry was relatively common. Factors such as the processing plant examined, season and the farms presenting birds for processing influenced the incidence of the pathogen. Significance and Impact of the Study: Differences were observed in the prevalence of Campylobacter spp. isolated from the two plants examined. The study suggests a seasonal prevalence of Campylobacter in the cooler months with processing conditions also influencing the overall occurrence of... [ABSTRACT FROM AUTHOR]

Investigates the natural campylobacter colonization and transmission among livestocks in dairy farm environment. General features of campylobacter; Relationship between human infection and ruminant animals; Potential sources of campylobacter infection among adult cattles; Needs to understand role of dairy farm in environmental cycle of the infection to devise intervention strategies.

Presents various index of authors as of December 2001. Name of authors; Pages of the publication; Title of the topics.

Various sample pre-treatment techniques and different growth media for the isolation of Legionellae from hot water supplies in public buildings were compared. A total of 102 hot water samples from taps and showers was examined. The highest recovery frequency was obtained with the heat pre-treatment method and using the selective medium GVPC. However, the results differed according to the concentration of legionellas. In the case of low plate counts (≤5000 cfu 1[sub -1]), the heat pre-treatment technique gave a significantly higher percentage of positive samples compared with other techniques (P < 0.05). With increasing concentration, the differences between the procedures decreased until they became statistically not significant for concentrations above 50 000 cfu 1[sup -1]. The direct inoculum method allowed a significantly higher detection of concentrations (P < 0.001) compared with heat and acid decontamination methods, which brought about a 67-68% reduction in detectable Legionellae. Heat decontamination techniques show greater sensitivity and specificity. However, they underestimate the number of legionellas. In environmental surveillance programmes, this underestimate must be taken into consideration when assessing the health risk. [ABSTRACT FROM AUTHOR]

The epidemiology of clinical cases of campylobacter in temperate climates shows a striking seasonality. In the search for a seasonal environmental reservoir changes in the carriage rate and population size of campylobacters in bovine hosts with time have been measured. Most probable number (MPN) methodology was used to enumerate thermophilic campylobacters in samples taken from the small intestines of beef cattle at slaughter and the fresh faeces of four dairy herds and new-born calves. Statistical analyses revealed significant evidence for seasonal periodicity in the data from dairy herds (P = 0·044). Not only was there a departure from constancy within a 12-month interval but these data revealed a true seasonality, that is, the same periodicity in numbers from one year to the next. Each herd had two peaks per year, in approximately spring and autumn. Peaks coincided in herds on neighbouring farms but those on farms in the north preceded those on farms in the south by 2 and 1 months, respectively (P = 0·0057). Intestinal carriage by beef cattle at slaughter was 89·4% (n = 360) with an average MPN campylobacters per gram fresh weight (MPN gfw-1) of 6·1 × 102. Average MPN gfw-1 in faeces from the dairy herds and calves were 69·9 (S.D. 3) and 3·3 × 104 (S.D. 1·7 × 102). There was no evidence of seasonal periodicity in the size of the campylobacter population in beef cattle at slaughter. Calves were campylobacter free at birth but became colonized within a few days. [ABSTRACT FROM AUTHOR]

Members of the genus Campylobacter have established themselves as the most common human gastro-enteric pathogens throughout much of the developed world. The ubiquitous distribution of Campylobacter spp. in animal reservoirs and food products derived thereof make such vehicles primary risk factors in contracting campylobacteriosis. The contamination rates, identification of common pathogenic serotypes and extended survival of Campylobacter in surface waters illustrates the potential, but yet to be quantified, campylobacteriosis risk associated with untreated water. The existence and potential pathogenicity of viable but nonculturable forms of Campylobacter remains a contentious subject. Furthermore, the role of such forms in the epidemiology of Campylobacter related disease and their involvement in the large number of waterborne gastroenteritis outbreaks from which a disease agent cannot be isolated remains to be fully clarified. This article presents a survey of current perspectives with regard to the survival and epidemiology of Campylobacter spp. in natural water systems. [ABSTRACT FROM AUTHOR]

Ninety-nine strains of Arcobacter spp., isolated from 10 chicken carcasses purchased from a supermarket and 15 chicken carcasses collected from a poultry abattoir, were speciated using a variety of phenotypic identification methods. All were tested using API Campy test strips and the 16-test (Preston) identification scheme developed for campylobacters. Fifty strains were selected for examination using a more comprehensive probabilistic identification scheme, and the identity of representative strains confirmed by protein profiling using SDS-PAGE. All 25 carcasses yielded Arcobacter butzleri . Three supermarket and 10 abattoir carcasses also carried A. cryaerophilus , and two abattoir carcasses carried A. skirrowii . The API Campy scheme proved unsatisfactory for identifying these strains: only 20 of 99 strains were accurately identified, all of which were A. cryaerophilus , the only Arcobacter sp. included in the database. Moreover, 76 of 99 strains were misidentified. The 16-test scheme identified all the arcobacter strains as A. cryaerophilus, since neither A. butzleri nor A. skirrowii had been described when the scheme was developed. The computer-assisted probabilistic scheme succeeded in identifying all but one strain, the identity of which was clarified by the use of SDS-PAGE. To our knowledge this is the first time that arcobacters other than A. butzleri have been reported in poultry meat or any other food of animal origin. Their high prevalence in poultry products may be of significance to public health. [ABSTRACT FROM AUTHOR]