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Bacillus cereus is an aerobic and facultatively anaerobic, spore-forming bacterium, and it is found naturally in soil and poses a risk factor for the contamination of food and foodstuffs including cereals, vegetables, spices, ready-to-eat (RTE) foods, meats, milk, and dairy products. This study determined the prevalence of B. cereus in raw poultry meat, raw cow’s milk, cheese, spices, and RTE foods in Hatay province. The study also analysed the psychrotrophic properties, toxigenic characteristics, and pulsed-field gel electrophoresis (PFGE) profiles of the isolates. The levels of contamination with B. cereus determined for cheese, raw milk, RTE foods, spices, and raw poultry meat were 16.6%, 34.2%, 42.8%, 49%, and 55.5%, respectively. B. cereus was isolated from 84 (42%) of the 200 samples analysed and the 84 isolates were verified by PCR analysis targeting the haemolysin gene specific for B. cereus. Of the total isolates, 64 (76.1%) were psychrotrophic. The toxin gene profiling of B. cereus isolates was determined by amplifying the four genes nhe, hbl, cytK, and ces. The nhe and cytK genes were most frequently detected in the isolates, while the hbl and ces genes were not found. In addition, a high genetic relationship between the isolates was detected at a 92% similarity level by PFGE analysis. In conclusion, the occurrence of both psychrotrophic and toxigenic B. cereus strains in this study indicated a potential risk for food spoilage and food poisoning.

Background & Objective: Methicillin-resistant Staphylococcus aureus (MRSA) is reported as one of the important bacterial causes of burn wound infections. This study was carried out to investigate molecular characterization of community-associated MRSA (CA-MRSA) isolated from Iranian burn patients. Methods: A total of 31 isolates of S. aureus were collected fromthe Motahari Burns Hospital (Tehran, Iran) in 2016. All isolates were collected from outpatients and inpatients within 48 hours of admission. The mecA, pvl, tsst-1, hla-α, and psmα genes detecting, SCCmec, agr and PFGE typing were done. Results: A total of 13 (41.9%) isolates were cefoxitin-resistant and mecA-positive, which were considered as MRSA. The SCCmec typing MRSA strains revealed type II in 1 (7.7%), type III in 9 (69.2%), and other types in 3 isolates (23.7%) cases. The agrtyping of all 31 isolates showed that 14 (45.2%), 1 (3.2%), 6 (19.4%), and 10 (32.3%) strains belonged to agr groups 1, 3, 4, and unknown type, respectively. The pvl, tsst-1, hla-α, and psmα genes were positive in 3 (9.7%), 4 (12.9%), 21 (67.7%), and 31 (100%) isolates, respectively. Considering the cut-off values of ≥50%, 3 groups of related isolates (cluster A1, B1, and C1) in PFGE study were observed. Conclusion: The MRSA strains of this study were initially isolated as Community-associated S. aureus (CA-MRSA); however molecular characterization showed that a significant proportion of them had hospital-associated MRSA (HA-MRSA) features. Therefore, it is likely that the HA-MRSA strains are spread among the community.

none 11 no This work was supported by Italian Ministry of Health (grant IZSUM 10, 2011). Toxigenic and antimicrobial susceptibility patterns and genetic relatedness of 42 non-O1/O139 V. cholerae strains, the majority of them isolated from seafood and marine water of the Adriatic sea, Italy, and 9 clinical strains, two of which with seawater of the Adriatic as the source of infection, were studied. All strains had hlyA El Tor gene but lacked ctxA gene. Four and two isolates, respectively, also had stn/sto and tcpA Class genes. More than 90% of strains showed susceptibility to cefotaxime, ciprofloxacin, cloramphenicol, tetracycline, trimethoprim þ sulfamethoxazole and intermediate or full resistance to tetracycline and erythromycin. Six strains of seafood and clinical source were multi-drug resistant. PFGE analysis allowed to type all the strains with 50 banding patterns. Twenty-one strains, 11 and 8 from seafood and seawater, respectively, and 2 of clinical origin, were grouped into 9 different clusters. We report the presence of toxigenic and multidrug resistant non-O1/O139 V. cholerae strains in Adriatic, some of which genetically related, and support that they represent a potential reservoir of toxin and antibiotic resistance genes. mixed Donatella, Ottaviani; Laura, Medici; Giulia, Talevi; Maira, Napoleoni; Patrizia, Serratore; Emanuele, Zavatta; Giorgia, Bignami; Laura, Masini; Serena, Chierichetti; Stefano, Fisichella; Francesca, Leoni Donatella, Ottaviani; Laura, Medici; Giulia, Talevi; Maira, Napoleoni; Patrizia, Serratore; Emanuele, Zavatta; Giorgia, Bignami; Laura, Masini; Serena, Chierichetti; Stefano, Fisichella; Francesca, Leoni

INTRODUCTION. Since the first report of vancomycin-resistant enterococci (VRE) in Poland, in 1996, these strains have spread in Polish hospitals, mainly due to selective pressure associated with increased use of vancomycin in the treatment of infections caused by methicillin-resistant staphylococci and Clostridium difficile. At the beginning of 2016 a growing number of patients colonized with VRE in the gastrointestinal tract was observed in the Children’s Memorial Health Institute (IPCZD). Some of these patients were transferred from other hospitals, and VRE colonization was found on admission. AIM. To analyze genetic similarity of VRE strains isolated from patients hospitalized in IPCZD and two other hospitals in Mazovian district, genetic typing by pulsed field gel electrophoresis (PFGE) was performed. MATERIALS AND METHODS. VRE strains were isolated from rectal swabs, and other clinical samples such as blood, cerebrospinal fluid, other body fluids, and environmental samples. A total of 56 VRE strains from IPCZD, 20 strains from Siedlce and 4 strains from patients from Grochowski Hospital in Warsaw were typed by PFGE. RESULTS. PFGE typing revealed 4 VRE clones containing several strains with identical restriction patterns. Among VRE strains isolated from neonates hospitalized in IPCZD, two clones with 24 and 20 identical strains were found. Respectively, 16 (67%) and 12 (60%) isolates were originated from rectal swabs from patients at admission to the hospital. Clonal strains were identified in all three hospitals included in the study. CONCLUSIONS. Our results showed that VRE strains had spread in the region. Isolation of clonal strains on admission to the hospital suggested independent VRE introductions from environment or other hospitals. Identification of clonal strains obtained from rectal swabs and other clinical samples during hospitalization indicated horizontal transmission.

Stenotrophomonas can survive in a wide range of environments and is considered an opportunistic pathogen. Because of its intrinsic resistance to beta-lactams, this genus is considered irrelevant in studies addressing the environmental spread of antimicrobial resistance genes of medical importance. Consequently, studies on environmental Stenotrophomonas carrying acquired carbapenemase-encoding genes are scarce, though not inexistent. Here, we investigated the frequency and diversity of Stenotrophomonas spp. carrying genes encoding carbapenemases of medical relevance in coastal waters with distinct pollution degrees over one year. Among 319 isolates recovered, 220 (68.9%) showed blaKPC. The frequency of blaKPC-positive Stenotrophomonas spp. was not correlated with thermotolerant counts in coastal waters evaluated. All isolates were susceptible to minocycline, levofloxacin, and trimethoprim-sulfamethoxazole. PFGE typing of 101 blaKPC-positive isolates revealed 55 pulsotypes with 5 subtypes, all of which carried the blaKPC-2 variant. Interspecies differentiation of pulsotypes' representatives revealed 55 isolates belonging to the S. maltophilia complex (91.7%) and 5 S. acidaminiphila (8.3%). The blaKPC-2 gene was more frequently harbored on transposable elements found in enterobacteria of clinical origin, especially Tn4401b. Even though beta-lactams are no therapeutic options to treat Stenotrophomonas infections, the occurrence of a highly relevant antimicrobial resistance determinant harbored on mobile genetic elements in a diverse collection of these ubiquitous microorganisms is noteworthy. Therefore, Stenotrophomonas may act as acceptor, stable reservoirs, and potential vectors of antimicrobial resistance in environmental settings, especially aquatic matrices, and should not be neglected.

Contaminated chicken products have been recognized as the primary vehicles of Campylobacter transmission to human. Pulsed-field gel electrophoresis (PFGE) and antimicrobial resistance of Campylobacter isolates from fresh chicken products at retail were studied. A total of 512 samples including: thigh, breast, marinated and minced chicken were purchased from different retail stores. Half of the samples were packed and the other half were unpacked. The 39.4% of the samples were Campylobacter positive; being unpacked chicken products (45.3%) more contaminated than packed chicken (33.6%). PFGE typing showed a high diversity among isolates; clustering 204 isolates into 76 PFGE types: 55 clusters of C. jejuni, 19 of C. coli and 2 of C. lari. C. coli genotypes showed higher resistance than other Campylobacter species. Although modified atmosphere packaging can reduce the prevalence of Campylobacter spp., it does not avoid their presence in at least 33.6% of packed chicken products analyzed. Some pulsotypes might persist in the processing plant or butcher shops environment for longer than previously thought. More stringent control measures are needed in previous steps of the chicken food chain, in order to avoid the presence of Campylobacter spp. strains at retail that can compromise consumer's safety., Ministerio de Economía y Competitividad” from the Spanish Government (AGL 2013–47694-R) and by “Junta de Castilla y Leon” (BU159U14)

We evaluated and critically assessed the performance and discriminatory power of a rep-PCR based commercial test DiversiLab® Enterococcus kit (bioMerieux) for typing a set of 65 representative isolates of Enterococcus faecium/VRE and compared it to state-of-the-art typing techniques such as PFGE and MLST.

Cross-contamination via equipment and the food-processing environment has been implicated as the main cause of Listeria monocytogenes transmission. The aim of this study, therefore, was to determine the occurrence and potential persistence of L. monocytogenes in 19 European cheese-processing facilities. A sampling approach in 2007-2008 included, respectively, 11 and two industrial cheese producers in Austria and the Czech Republic, as well as six Irish on-farm cheese producers. From some of the producers, isolates were available from sampling before 2007. All isolates from both periods were included in a strain collection consisting of 226 L. monocytogenes isolates, which were then typed by serotyping and pulsed-field gel electrophoresis (PFGE). In addition, metabolic fingerprints from a subset of isolates were obtained by means of Fourier-transform infrared (FTIR) spectroscopy. PFGE typing showed that six processing environments were colonized with seven persistent PFGE types of L. monocytogenes. Multilocus sequence typing undertaken on representatives of the seven persisting PFGE types grouped them into distinct clades on the basis of country and origin; however, two persistent strains from an Austrian and an Irish food processor were shown to be clonal. It was concluded that despite the fact that elaborate Hazard Analysis and Critical Control Point concepts and cleaning programs are applied, persistent occurrence of L. monocytogenes can take place during cheese making. L. monocytogenes sanitation programs could be strengthened by including rapid analytical tools, such as FTIR, which allow prescreening of potentially persistent L. monocytogenes contaminants.

The first plasmid-mediated AmpC β-lactamase-producing Klebsiella pneumoniae (pAmpC KP) isolate was detected in December 2009 in Hungary. Hungarian microbiological laboratories were asked to send all KP strains showing cefoxitin resistance and decreased susceptibility or resistance to any third-generation cephalosporins to the Reference Laboratories at the National Center for Epidemiology. Investigation was conducted in order to outline spatio-temporal distribution and genetic characterization of pAmpC-KP isolates in Hungary. Between December 2009 and December 2013, 312 consecutive KP clinical isolates were confirmed as producing pAmpCs. All isolates showed resistance to third-generation cephalosporins, aminoglycosides and fluoroquinolones, and 77 % were non-susceptible to at least one carbapenem. Analysis of β-lactamase genes showed bla DHA-1 in all and additionally bla CTX-M-15 in 90 % of isolates. PFGE typing revealed 12 pulsotypes; of these, KP053 (262/312) and KP070 (38/312) belonged to sequence type ST11 and comprised 96 % of the isolates. The bla DHA-1 and bla CTX-M-15 co-producing KP053/ST11 clone affected 234 patients and spread to 55 healthcare centres across Hungary during the study period. Three KP053 isolates were also resistant to colistin. In two of these, the mgrB gene was truncated by IS10R, while in the third isolate, insertional inactivation of mgrB by ISKPn14 was identified. Hungary is the first European country showing endemic spread of bla DHA-1 facilitated by the international high-risk clone ST11. The rapid countrywide spread of this multidrug-resistant clone seriously endangers Hungarian healthcare facilities and warrants strengthening of infection control practices and prudent use of carbapenems and colistin.

Pulsed-field gel electrophoresis (PFGE) is considered a "gold standard" for the molecular characterization of a number of bacterial strains. Its strength relies on its high discriminatory power, together with its high reproducibility. For many years, an international network, PulseNet International, allows the rapid comparison of PFGE data obtained all over the world, and it provides a valuable tool to promptly recognize the epidemiological dynamics of many pathogens, including Salmonella enterica. Here we describe the laboratory procedure to perform the standardized protocol for the PFGE typing of S. enterica strains.

This study aims to determine the presence of extended-spectrum (ESBL) and plasmidic class C beta-lactamase-producing Enterobacteriaceae in poultry, pig and rabbit farms of Catalonia (Spain). PFGE typing showed a low clonal relationship among strains carrying these mechanisms of resistance. Ninety-three percent of them were resistant to two or more of the non-beta-lactam antimicrobials tested and harboured ESBL and plasmidic class C beta-lactamases. Greater diversity of these enzymes was found in strains from poultry farms, the CTX-M-9 family, especially CTX-M-14, with CMY-2 being the most frequent. The isolation of TEM-52 and SHV-2-producing Escherichia coli strains from these animal farms is noteworthy. In contrast, 73% of the strains from pig farms had CTX-M-1, and neither the CMY-type nor CTX-M-9 family enzyme was found. Likewise, it is the first time that CTX-M-1 and SHV-5 encoding strains have been isolated in pigs. On the other hand, in rabbit farms CTX-M-9 family was also the most frequent, being detected in three of a total of four strains. The last one showed a CMY-2, for the first time detected in these animals, too. In conclusion, commensal E. coli strains of food-producing animal farms are a reservoir of ESBL and plasmidic class C beta-lactamases.

Pulsed-field gel electrophoresis (PFGE) is currently considered the gold standard for genotyping of enterococci. However, PFGE is both expensive and time-consuming. The purpose of this study was to investigate whether the PhP system can be used as a reliable clinical screening method for detection of genetically related isolates of enterococci. If so, it should be possible to minimize the number of isolates subjected to PFGE typing, which would save time and money. Ninety-nine clinical enterococcal isolates were analysed by PhP (similarity levels 0.90-0.975) and PFGE (similarity levels < or =3 and < or =6 bands) and all possible pairs of isolates were cross-classified as matched or mismatched. We found that the probability that a pair of isolates (A and B) belonging to the same type according to PhP also belong to the same cluster according to PFGE, i.e. p(A(PFGE)=B(PFGE) * A(PhP)=B(PhP)), and the probability that a pair of isolates of different types according to PhP also belong to different clusters according to PFGE, i.e. p(A(PFGE) not equalB(PFGE) * A(PhP) not equalB(PhP)), was relatively high for E. faecalis (0.86 and 0.96, respectively), but was lower for E. faecium (0.51 and 0.77, respectively). The concordance which shows the probability that PhP and PFGE agree on match or mismatch was 86%-93% for E. faecalis and 54%-66% for E. faecium, which indicates that the PhP method may be useful for epidemiological typing of E. faecalis in the current settings but not for E. faecium.

SUMMARY. Fifty cases submitted between 2000 and 2002 were selected for retrospective analysis to evaluate possible relationships between Salmonella arizonae isolated from breeder flocks, hatching eggs, and meat bird flocks belonging to a single turkey integrator. In all the meat bird cases selected for this study, arizonosis was the primary diagnosis. In birds under 1 month of age, clinical signs and pathologic changes were observed in older birds. The Salmonella arizonae isolates were analyzed by antibiotic resistance pattern and serotype and genotyped by pulsed-field gel electrophoresis (PFGE). Serotyping and PFGE yielded similar results, but the antibiotic resistance patterns did not correspond to either serotyping or PFGE typing. The presence of common pulsed-field patterns in breeder flocks, eggs, and meat bird flocks suggested that S. arizonae was being transmitted vertically from the breeder flock.

Background: The Liverpool epidemic strain (LES) of Pseudomonas aeruginosa is widespread among patients with cystic fibrosis (CF) in specialist centers around Liverpool and elsewhere in the UK. This study evaluates a new diagnostic PCR assay based on a unique DNA sequence (PS21) of LES, for its identification of colonies directly from sputum. Methods: One hundred and fifty-eight sputum samples from 92 patients were cultured and P. aeruginosa isolates were typed by PS21 PCR and pulsed-field gel electrophoresis (PFGE). Subsequently, PS21 PCR was performed directly on sputum and the results were compared with culture, PFGE, and PS21 PCR typing. Results: Eighty patients were colonized with P. aeruginosa, 63 by LES (79%). There was 100% concordance between PS21 PCR on colonies and PFGE typing. The sensitivity and specificity of PS21 PCR directly on sputum was 98.2% and 93.6%, respectively. Conclusions: This study shows that PS21 PCR can be used for simple and rapid screening of LES colonization in CF patients.

The aim of this investigation was to study the molecular epidemiology of Stenotrophomonas maltophilia in a university hospital in Italy. Sixty-one clinical isolates were collected from 43 patients during a two-year period. The majority of specimens were from the respiratory tract (41 of 43) of patients in the adult intensive care unit (ICU) (19 of 43) or cystic fibrosis (CF) patients (13 of 43). Genotypic analysis by pulsed-field gel electrophoresis (PFGE) of clinical isolates identified 31 different PFGE patterns. Although most patients were infected or colonized by different S. maltophilia clones, clones with identical genotype were isolated in patients from ICU, where two separate outbreaks were identified. Antimicrobial susceptibility identified a multi-resistant phenotype in all S. maltophilia PFGE clones. The majority of PFGE clones identified (six of seven clones from patients in the ICU) were susceptible to fluoroquinolones. Mechanical ventilation was associated with S. maltophilia acquisition in the ICU.

Objective: Pulsed-field gel electrophoresis (PFGE) was used to investigate an outbreak of gastroenteritis caused by Salmonella enteritidis . The outbreak occurred among university undergraduates who consumed contaminated food. Method: Molecular typing was done by analyzing DNA band patterns of isolates of S. enteritidis after digestion of chromosomal DNA with infrequently-cutting restriction endonucleases Xba I, Avr II, and Spe I and separation of DNA fragments using PFGE. Results: Twenty-nine outbreak isolates of S. enteritidis had identical or highly similar PFGE patterns, whereas different PFGE patterns were observed among three epidemiologically unrelated isolates obtained during the same period. Conclusion: The data obtained confirm the value of PFGE in epidemiologic investigations of outbreaks caused by S. enteritidis .

The European Union Reference Laboratory ( EURL ) for Listeria monocytogenes ( Lm ) collaborates with a network of 35 National Reference Laboratories (NRLs) throughout Europe. Most of these NRLs are in charge of detecting and typing Lm strains from food, environment and animals, which are isolated nationally. The past few years EURL activities have enabled NRLs to reinforce typing capabilities according to standardised protocols. Consequently the need to exchange typing data within the NRL network has emerged. That is why the EURL has recently set up a EURL Lm Database (EURL Lm DB). Each NRL contributes data, which is then shared within the network. Data include strain-typing-results (PFGE and serotyping) and epidemiological information on the strains. This article describes (1) the EURL typing activities that led to the creation of the EURL Lm DB, (2) the different steps involved in developing the EURL Lm DB, and (3) the usefulness of this database for public health. The combined use of this database, with databases on human strains, is being integrated into the European surveillance system of Lm strains circulating throughout Europe. It should improve the detection of this pathogen and provide support for outbreak investigations.

To genotypically characterize methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from medical and surgical wards in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) in 2009.MRSA strains were collected and molecularly typed by pulsed-field gel electrophoresis (PFGE).PFGE typing on 180 MRSA isolated in UKMMC identified 5 pulsotypes (A-E) and 6 singletons, where pulsotypes B and C were suspected to be divergent clones originating from a single ancestor. This study also showed that most MRSA strains were isolated from swab (119 isolates), followed by blood (22 isolates), tracheal aspirate (11 isolates) and sputum (10 isolates). On the other hand, urine and bone isolates were less, which were 4 and 1 isolates, respectively. The distribution of different pulsotypes of MRSA among wards suggested that MRSA was communicated in surgical and medical wards in UKMMC, with pulsotype B MRSA as the dominant strain. Besides, it was found that most deceased patients were infected by pulsotype B MRSA, however, no particular pulsotype could be associated with patient age, underlying disease, or ward of admittance.Five pulsotypes of MRSA and 6 singletons were identified, with pulsotype B MRSA as the endemic strains circulating in these wards, which is useful in establishment of preventive measures against MRSA transmission.

Escherichia coli clonal group A (CgA) causes disease in humans. This is the first study investigating the prevalence of CgA among E. coli from non-urine, extraintestinal infections in a northern European country. E. coli blood (n = 196) and paired urine (n = 195) isolates from the same patients with bacteraemia of urinary tract origin were analysed. The isolates were collected from January 2003 through May 2005 at four hospitals in Copenhagen, Denmark. Pulsed-field gel electrophoresis (PFGE) patterns, antimicrobial resistance and patient characteristics were determined for all CgA isolates; presence of virulence-associated genes (VAGs) and serotypes were determined for the blood CgA isolates. Thirty blood isolates (15%) belonged to CgA. CgA blood isolates were associated with female patients and sulfamethoxazole-trimethoprim resistance and they harboured a distinctive VAG profile. The blood and urine isolates from each pair were found to be related in 26 of 27 CgA blood/urine pairs, confirming a urinary tract origin of infection. Furthermore, a relationship between the PFGE patterns of CgA blood/urine isolates and CgA isolates from UTI patients in general practice and a CgA isolate from a community-dwelling human reported previously, was found, suggesting a community origin of CgA. The finding of CgA strains in 15% of the E. coli bloodstream infections with a urinary tract origin in Denmark suggests that CgA constitutes an important clonal lineage among extraintestinal pathogenic E. coli. A reservoir of this pathogenic E. coli group in the community causing not only UTI but also more severe infections such as bacteraemia has implications for public health.

Clostridium difficile strains of toxinotypes III (n = 13) and V (n = 45) were typed by agarose gel-based PCR ribotyping, capillary gel electrophoresis-based PCR ribotyping and PFGE using two different restriction enzymes, SmaI and SacII. With conventional agarose gel-based PCR ribotyping, toxinotype III strains were distributed among six different PCR ribotypes and toxinotype V strains into three different PCR ribotypes. Capillary gel electrophoresis-based ribotyping was more discriminatory for toxinotype V strains, with six different ribotypes found. With PFGE using SmaI, all toxinotype III strains grouped together into a single pulsotype. Using SacII, ribotype 027 strains grouped together with >90 % similarity and were

An increased number of Salmonella Typhimurium cases were reported in Switzerland between May and June 2008. Investigations involved 72 cases. Results of PFGE typing identified several outbreak strains, the dominating one present in 43 of the 72 isolates. Strains affecting one third of the cases were also found in animal samples, in particular pork. However, no specific food source could be identified. Outbreaks described in this paper highlight the importance of food safety regulations such as those on minced meat and meat preparations issued by the European Commission and adopted by Switzerland into the national law.

The emergence of acinetobacters, withAcinetobacter baumannii in particular, as nosocomial pathogens has raised questions about their diversity, and the sources and mode of spread of particular strains. These questions cannot be answered without the availability of methods for strain typing. Over the past decades, there has been an explosive development of typing methods and many of these have been instrumental in the study of acinetobacters, not only for outbreak analysis but also for other purposes. The present paper provides an overview of applications of methods in the study of these organisms.

The subtypes of Campylobacter isolates from human infections in two Danish counties were compared to isolates from retail food samples and faecal samples from chickens, pigs and cattle. During a 1-year period, 1285 Campylobacter isolates from these sources were typed by two methods: ‘Penner’ heat-stable serotyping and automated ribotyping (RiboPrinting). C. jejuni was the dominating species, but C. coli was more prevalent among food and chicken isolates (16%) compared to human isolates (4%). In total, 356 different combined sero-ribotypes (subtypes) were found. A large subtype overlap was seen between human isolates and isolates from food (66%), chickens (59%) and cattle (83%). This was verified by PFGE typing of 212 isolates representing selected subtypes. All frequent (n>3) subtypes found in food were also present in humans. Sixty-one per cent of the isolates from domestically acquired infections had subtypes that were also found in food as opposed to 31% of travel-associated infections. The results showed differences in the various Campylobacter populations, e.g. the Danish population as reflected in the domestically acquired infections and the Danish-produced food was more uniform than the isolates originating from outside the country. The study shows that most C. jejuni subtypes found in poultry food samples, broiler chickens, and cattle were represented in the domestically acquired cases, indicating that C. jejuni from these reservoirs are likely sources of human infections in Denmark.

The molecular epidemiology of Legionella pneumophila in the 'V. Monaldi' University Hospital was studied. Seven cases of nosocomial Legionnaires' disease were diagnosed between 1999 and 2003. Two clinical legionella strains obtained from two patients in the adult cardiac surgery unit (CSU) and 30 environmental legionella strains from the paediatric and adult CSUs, neonatal intensive care unit (NICU) and the cardiorespiratory intensive care unit (CR-ICU) were serotyped and genotyped. L. pneumophila serogroup 1/Philadelphia with an identical pulsed-field gel electrophoresis (PFGE) profile A was isolated from two patients in the adult CSU, and from three and one water samples taken in the adult CSU and the paediatric CSU, respectively, from 2001 to 2002. Furthermore, L. pneumophila serogroup 3 with an identical PFGE profile B was identified in 20 environmental strains from all wards, L. pneumophila serogroup 3 with PFGE profile C was identified in a single environmental strain from the CR-ICU, and non-pneumophila Legionella with identical PFGE profile D was identified in five environmental strains from the adult CSU, paediatric CSU and NICU. Ultraviolet irradiation was effective in disinfection of the hospital water supplies in the adult and paediatric CSUs contaminated by L. pneumophila clone associated with nosocomial Legionnaires' disease. In conclusion, these data demonstrate that two cases of nosocomial legionellosis were caused by the persistence of a single clone of L. pneumophila serogroup 1/Philadelphia in the hospital environment, and that disinfection by ultraviolet irradiation may represent an effective measure to prevent nosocomial Legionnaires' disease. © 2005 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

Summary Some dental procedures initiate a bacteraemia. In certain compromised patients, this bacteraemia may lead to distant site infections, most notably infective endocarditis. Objective. To investigate whether a detectable bacteraemia was produced during non-surgical root canal therapy. Methods. Thirty patients receiving non-surgical root canal therapy were studied. Three blood samples were taken per patient: pre-operatively, peri-operatively and post-operatively. In addition, a paper point sample was collected from the root canal. The blood samples were cultured by pour plate and blood bottle methods. The isolated organisms were identified by standard techniques. Blood samples were analysed for the presence of bacterial DNA by the polymerase chain reaction (PCR). In two cases where the same species of organism was identified in the root canal and the bloodstream, the isolates were typed by pulsed field gel electrophoresis (PFGE). Results. By conventional culturing, a detectable bacteraemia was present in 9 (30%) of the 30 patients who had no positive pre-operative control blood sample. In 7 (23.3%) patients, the same species of organism was identified in both the bloodstream and in the paper point sample from the root canal system. Overall, PCR gave lower detection rates compared with conventional culture, with 10 of 90 (11%) of the blood samples displaying bacterial DNA. PFGE typing was undertaken for two pairs of culture isolates from blood and paper points; these were found to be genetically identical. Conclusions. Non-surgical root canal treatment may invoke a detectable bacteraemia.

Escherichia coli is a normal host of intestinal flora. Thus, for food industry, it is a good indicator of feco-oral contaminations. However, some serotypes (defined by the combination of somatic O and flagellar H antigens), or serogroups, (just defined by the antigen O alone) of this species can be pathogenic: it is the case for O157:H7, O26, or O111. They can be potentially responsible for collective food toxi-infections and more seriously for the Haemolytic and Uraemic Syndrome (HUS) due to enterohemorhagic Escherichia coli (EHEC) The Reference National Center for E. coli and Shigella is in charge of characterizing pathogenic E coli and detecting their pathogenicity genes, and participating to epidemic investigation. This is done, first of all, by using serotyping with sera, molecular serotyping which can determine the serotype, then by the detection of pathogenicity genes which can define pathovars of E. coli. Ribotyping and PFGETyping techniques, which are epidemiological markers, allow a more precise molecular identification, and contribute to epidemic analysis. The molecular characterization of the serogroup O111 of E. coli and the pathogenicity factor detection showed there were a great antigenic and pathogenic diversity among these strains, and a good correlation between serotypes and pathovars. This study demonstrated that serotyping is not sufficient and pathogenicity genes should be searched for. PFGEtyping, being highly discriminative, showed a large diversity within serogroup O111., Escherichia coli est un hôte normal de la flore intestinale. De ce fait, pour l’industrie agroalimentaire, c’est un bon indicateur de contaminations feco-orales. Cependant certains sérotypes (définis par la combinaison des antigènes somatiques O et flagellaires H) ou sérogroupes (définis par l’antigène somatique seul) de cette espèce peuvent être pathogènes, c’est le cas pour des O157 : H7, O26, ou O111. Ils peuvent être responsables de toxi-infections alimentaires collectives et plus gravement du Syndrome Hémolytique et Urémique (SHU) lorsque la bactérie incriminée d’après ses gènes de pathogénicité est un Escherichia coli entérohémoragique ou EHEC. Le Centre National de Référence des E. coli et Shigella est chargé de caractériser les E. coli pathogènes, de détecter leurs gènes de pathogénicité, et de participer à l’investigation de phénomènes épidémiques. Celà s’effectue, tout d’abord, grâce à la sérotypie à l’aide de sérums, au sérotypage moléculaire permettant de déterminer le sérotype, puis par la recherche de gènes de pathogénicité qui permet de définir le pathovar de E. coli. Les techniques de ribotypie et de pulsotypie, qui sont des marqueurs épidémiologiques, permettent une identification moléculaire plus précise, contribuant à des analyses épidémiques plus poussées. La caractérisation moléculaire des E. coli du sérogroupe O111 et la détection desfacteurs de pathogénicité ont montré qu’il existait parmi les souches une grande diversité antigénique et pathogénique, une bonne corrélation entre sérotypes et pathovars. Cette étude démontre que le sérotypage ne suffit pas et qu’il faut rechercher aussi les gènes de pathogénicité. La pulsotypie par une forte discrimination montre aussi une très grande diversité au sein du sérogroupe O111.