A novel group of IncQ1 plasmids conferring multidrug resistance.

The IncQ is a group of non-conjugative but mobilisable plasmids that are found and stably maintained in a wide range of bacteria contributing to the spread of antimicrobial resistance genes and to the insurgence of multidrug resistant bacteria. Here we report the identification, in clinical Salmonella Typhimurium strains, of an IncQ1 plasmid (pNUC) which confers resistance to sulfamethoxazole, streptomycin and tetracycline through the presence of sul2, strAB and tetA genes, respectively. pNUC was detected in five multidrug resistant S. Typhimurium strains collected in Southern Italy from various hospitals and years of isolation. Bioinformatics analyses highlighted the presence of pNUC-like plasmids in pathogenic bacteria of various Enterobacteriaceae genera or species. Taken as a whole, these plasmids constitute a novel group of IncQ1 plasmids that might have originated through recombination events between a tetR-tetA gene cluster (possibly derived from a Tn1721) and a recipient IncQ1 plasmid related to RSF1010. Our findings raise concerns regarding the possible contribution of the newly identified group of IncQ1 plasmids to the spread of tetracycline resistance.

Molecular characterization and antibiotic resistance of salmonella serovars isolated in the Apulia region of Italy.

During the period January 2013-December 2015, 175 cases of human salmonellosis were reported in the Apulia Region of Italy. The aim of this study was to characterize salmonella strains from the standpoints of serovars prevalence, antimicrobial resistance and clonal origin. The serological typing was performed by agglutination against antisera followed by a multiplex polymerase chain reaction (m-PCR). The obtained results were analyzed following the Kauffmann-White scheme. Susceptibility to antimicrobial agents was tested using the disk diffusion method on Muller-Hinton agar plates. All strains were tested by pulsed-field gel electrophoresis (PFGE) according to the PulseNet protocol, and cluster analysis was performed using BioNumerics software. It was found that the most prevalent isolated serovars were in order: i) S.Enteritidis, ii) S.Typhimurium and iii) S. 4,[5],12:i:–. The most common resistances were: i) Ampicillin (A) (38%), ii) Amoxicillin/Clavulanic Acid (AmC) (11%), iii) Streptomycin (S) (19%), iv) Sulphonamides (Su) (19%), v) Tetracycline (T) (30%), and vi) Piperacillin (Pip) (25%). Ten multidrugresistant (MDR) patterns were identified among the isolates, and the two most diffused ones were ASSuT and ASSuTPip, respectively. MDR patterns were predominantly expressed by Salmonella Typhimurium and Salmonella 4,[5],12:i:-. Molecular typing by PFGE yielded 60 different macrorestriction profiles among 33 serotypes.

Characterisation of Yersinia pseudotuberculosis isolated from animals with yersiniosis during 1996-2013 indicates the presence of pathogenic and Far Eastern strains in Italy.

Yersinia pseudotuberculosis is a pathogen that infects both animals and humans worldwide. The epidemiology of infection caused by Y. pseudotuberculosis is poorly understood; however, its outbreaks have been traced back to a probable source in wildlife. This study aimed to characterise Y. pseudotuberculosis isolates collected from animals with yersiniosis. This study included 90 isolates of Y. pseudotuberculosis collected from different animals with yersiniosis between 1996 and 2013 in Italy. The isolates were tested for antimicrobial susceptibility and were biotyped. Genes associated with virulence plasmid pYV and those encoding O-antigen, high pathogenicity island (HPI), and superantigenic toxin (YPM) were determined by performing PCR. Pulsed-field gel electrophoresis (PFGE) was performed using NotI and SpeI enzymes, and 3 dendrograms were generated. No antibiotic resistance was found. The presence of pYV was shown in 57 out of 90 isolates. Virulence profiles of majority of the isolates indicated that they belonged to O:1a and O:1b serotypes, biotype 1, and genetic type 2. Isolates belonging to O:2a serotype were detected in sheep and cattle and were found to be associated (for the first time) with septicemia in hares. Y. pseudotuberculosis isolates belonging to O:5a and O:12-O13 serotypes were also detected in hares. To our knowledge, this is the first study to detect Y. pseudotuberculosis isolates belonging to the O:12-O13 serotype from a clinical case in Europe. Results of PFGE indicated that it was a reliable method for investigating the genetic relatedness of Y. pseudotuberculosis isolates. Thus, characterisation of Y. pseudotuberculosis infection in animals should be considered a possible tool for the surveillance of pseudotuberculosis.

Characterization of an unusual Salmonella phage type DT7a and report of a foodborne outbreak of salmonellosis.

Salmonella enterica subsp. enterica serovar 4,[5],12,i:- is a monophasic variant of Salmonella Typhimurium and its occurrence has markedly increased in several European countries in the last ten years. In June 2011, an outbreak of Salmonella 4,[5],12,i:- was reported among attendees of a wedding reception in the North-East of Italy. The source of this outbreak was identified as a cooked pork product served during the wedding reception. All Salmonella isolates from humans and the contaminated pork products were identified as Salmonella 4,[5],12,i:- and phage typed as DT7a. Afterwards, the farm where the pigs were raised was identified and sampled, and Salmonella Typhimurium was isolated from swine fecal samples. Despite the difference in serovar, these Salmonella Typhimurium isolates were also phage typed as DT7a. In the present study, Salmonella isolates from animals, humans and pork products during the outbreak investigation were subtyped by pulsed-field gel electrophoresis (PFGE), Multiple-Locus Variable number tandem repeats Analysis (MLVA), and resistance patterns, aiming to identify the most suitable subtyping methods to characterize isolates associated with this outbreak. In addition, a collection of epidemiologically unrelated strains of Salmonella 4,[5],12,i:- and Salmonella Typhimurium sharing the same phage type (DT7a) was similarly characterized in order to investigate their genetic relationship. This study provides a first snapshot of a rare Salmonella phage type, DT7a, associated with both Salmonella 4,[5],12,i:- and Salmonella Typhimurium. Moreover, the study demonstrated that in this specific context MLVA could be a reliable tool to support outbreak investigations as well as to assess the genetic relatedness among Salmonella isolates.

Attribution of human Salmonella infections to animal and food sources in Italy (2002-2010): adaptations of the Dutch and modified Hald source attribution models.

The Dutch and modified Hald source attribution models were adapted to Italian Salmonella data to attribute human infections caused by the top 30 serotypes between 2002 and 2010 to four putative sources (Gallus gallus, turkeys, pigs, ruminants), at the points of animal reservoir (farm), exposure (food), and both combined. Attribution estimates were thus compared between different models, time periods and sampling points. All models identified pigs as the main source of human salmonellosis in Italy, accounting for 43-60% of infections, followed by G. gallus (18-34%). Attributions to turkeys and ruminants were minor. An increasing temporal trend in attributions to pigs and a decreasing one in those to G. gallus was also observed. Although the outcomes of the two models applied at farm and food levels essentially agree, they can be refined once more information becomes available, providing valuable insights about potential targets along the production chain.

Cholera with severe renal failure in an Italian tourist returning from Cuba, July 2013.

In July 2013, an Italian tourist returning from Cuba was hospitalised in Trieste, Italy, for cholera caused by Vibrio cholerae O1 serotype Ogawa with severe renal failure. An outbreak of cholera was reported in Cuba in January 2013. Physicians should consider the diagnosis of cholera in travellers returning from Cuba presenting with acute watery diarrhoea.

A multistate epidemic outbreak of Salmonella Goldcoast infection in humans, June 2009 to March 2010: the investigation in Italy.

After an urgent inquiry into a suspected international outbreak of Salmonella Goldcoast infection was launched by Hungary in October 2009 a nationwide multidisciplinary investigation was carried out in Italy. The aims were to verify whether the higher than expected number of cases of S. Goldcoast infection that had occurred in Italy in the previous months were linked to the outbreak in Hungary and to determine their origin. Between June 2009 and March 2010, 79 confirmed cases of S. Goldcoast infection were identified. Of these, 17 were part of three different point-source outbreaks probably associated with the consumption of salami. Eating salami was also reported by 20 of the 39 sporadic cases that could be interviewed. Fifteen strains of S. Goldcoast isolated from the cases were typed by pulsed-field gel electrophoresis. They shared more than 90% homology with the Hungarian epidemic strain and were also highly similar to S. Goldcoast strains that had been isolated in Italy from pigs and pork-containing food items in 2009 and 2010. Although the origin of the outbreak and the common source linking the Hungarian and the Italian cases could not be definitively identified, our results suggest a possible zoonotic connection of the outbreak cases with the pork production chain.

[Vibrio spp. infections of clinical significance and implication for public health]. / Infezioni da Vibrio spp. di interesse clinico e problematiche di Sanitå Pubblica.

Vibrio spp. infections still are a Public Health concern. Vibrio spp. can be found in marine, estuarine, and freshwater environments, and can be able to cause diseases in fish, shellfish, mammals, as well as in humans. Since '80 to date, the number of species within the genus increased from 21 to more than 100. The most important is Vibrio cholerae, the etiological agent of the cholera, responsible of seven pandemics; serotypes O1 and O139 can produce cholera toxin, while serotypes non-O1/non-O139 are generally associated with sporadic cholera cases and extraintestinal infections. Vibrio parahaemolyticus is an important cause of gastroenteritis associated with contaminated seafood consumption, whereas Vibrio vulnificus and V. alginolyticus can be related to wound infections or seafoodborne primary septicemia in immunocompromised patients. Disease prevention is mainly based on the application of proper individual or collective preventive measures.

Ciprofloxacin-resistant, CTX-M-15-producing Escherichia coli ST131 clone in extraintestinal infections in Italy.

Quinolone and ß-lactam resistance mechanisms and clonal relationships were characterized among Escherichia coli isolates resistant to ciprofloxacin and extended-spectrum cephalosporins associated with human extra-intestinal infections in Rome. The E. coli. ST131 clone was found to be prevalent. This clone invariably carried a specific pattern of substitutions in the topoisomerase genes and all isolates but one produced CTX-M-15. One ST131 isolate produced SHV-12. The new ST131 variant described here is of particular concern because it combines fluoroquinolone resistance and chromosomally encoded CTX-M-15.

Antimicrobial resistance in Salmonella enterica serovar Typhimurium from human and animal sources in Italy.

Salmonella Typhimurium strains isolated in Italy in the period 2002-2004 from human and animal sources were examined for their antimicrobial susceptibility. Resistance to tetracycline (T, 73.6%), sulfonamides (Su, 73.3%), ampicillin (A, 67.6%), streptomycin (S, 65.4%) and chloramphenicol (C, 32.3%) were frequently observed. Resistance to ciprofloxacin was only observed in a swine strain, but most human strains resistant to nalidixic acid showed reduced susceptibility to that drug (MIC > or = 0.125 mg/l). Overall, 64% of the strains were resistant to four or more drugs. The most common resistance profiles were ACSSuT, prevalent in strains belonging phage type DT104 and ASSuT, prevalently associated with strains unable to be typed.

An Easter outbreak of Salmonella Typhimurium DT 104A associated with traditional pork salami in Italy.

Salmonella enterica is a common cause of gastrointestinal illness in Italy. S. Typhimurium accounts for approximately 40% of isolates, and most of these strains belong to the phage type DT104. We describe the investigation of an outbreak of S. Typhimurium DT104A, a subtype never observed before in Italy, which occurred in Rome during spring 2004.We conducted a matched case control study between 24 July and 9 September 2004. Controls were matched for age and area of residence. Each case had between one and four controls. Odds of exposure to potential risk factors and vehicles for the outbreak were compared between cases and controls. A multivariate analysis was conducted to estimate adjusted Odds Ratios.Sixty-three cases of S. Typhimurium DT 104A infection with onset between 1 April and 5 May 2004 were identified. Sixty-one were residents of Rome and two were residents of a neighbouring region. Twenty-six cases (43%) were enrolled in the study. Their median age was 7.5 years. Fourteen of 26 cases and 16 of 62 controls had eaten pork salami (OR= 25.5; 95% CI 1.6- 416.8). No food samples were available for testing. In northern Italy, two months prior to the outbreak, the veterinary surveillance system identified the first isolation of S. Typhimurium DT104A in a pig isolate. Both human and pig isolates showed indistinguishable PFGE patterns. It was not possible to trace the pig after the sample was taken at slaughter. The epidemiological evidence on the implication of pork salami in this outbreak suggests that pork products can also be a vehicle for salmonella in Italy and underlines the importance of good manufacturing practices for ready-to-eat foods. This investigation highlights the value of laboratory-based surveillance in identifying community-wide outbreaks of uncommon pathogens. It also underlines the need to improve surveillance timeliness, for promptly detecting outbreaks, undergoing field investigation, and implementing control measures. Moreover, our study shows the usefulness of integrated human and animal surveillance in tracing the possible source of infection.

Relationship of pulsed-field profiles with key phage types of Salmonella enterica serotype Enteritidis in Europe: results of an international multi-centre study.

Salmonella is one of the most common causes of foodborne infection in Europe with Salmonella enterica serovar Enteritidis (S. Enteritidis) being the most commonly identified serovar. The predominant phage type for S. Enteritidis is phage type (PT) 4, although PT 8 has increased in incidence. Within these phage types, pulsed-field gel electrophoresis (PFGE) provides a method of further subdivision. The international project, Salm-gene, was established in 2001 to develop a database of PFGE profiles within nine European countries and to establish criteria for real-time pattern recognition. It uses DNA fingerprints of salmonellas to investigate outbreaks and to evaluate trends and emerging issues of foodborne infection within Europe. The Salm-gene database contains details of about 11 700 S. Enteritidis isolates, demonstrating more than 65 unique PFGE profiles. The clonal nature of S. Enteritidis is evidenced by the high similarity and distribution of PFGE profiles. Over 56% (6603/11 716) of the submitted isolates of several different phage types were profile SENTXB.0001, although this profile is most closely associated with PT 4. The next most common profiles, SENTXB.0002 and SENTXB.0005, were closely associated with PT 8 and PT 21 respectively. Studies to investigate the relationship of profile types with outbreaks and possible vehicles of infection suggest that the incidence of PFGE profile SENTXB.0002, and thus PT 8, in some countries may be due to importation of foods or food production animals from Eastern Europe, where PT 8 is amongst the most frequently identified phage types. Collation of subtyping data, especially in the commonly recognized phage types, is necessary in order to evaluate trends and emerging issues in salmonella infection.

Distribution of molecular subtypes within Salmonella enterica serotype Enteritidis phage type 4 and S. Typhimurium definitive phage type 104 in nine European countries, 2000-2004: results of an international multi-centre study.

This study investigates the distribution of pulsed-field gel electrophoresis (PFGE) profiles within Salmonella enterica serotype Enteritidis phage type (PT) 4 and S. Typhimurium definitive phage type (DT) 104, from cases of human infection in nine European countries from 2000 to 2004. Isolates were subtyped using standardized methods and gel images submitted by each participating country to the coordinating centre (Health Protection Agency Centre for Infections, London, UK), where they were entered into a central database, developed within BioNumerics software, and designated using an agreed nomenclature. S. Enteritidis PT4 (n=3637) was differentiated into 38 different profiles. Simpson's index of diversity (D) of profiles ranged from 0.2 to 0.4. Profile SENTXB.0001 represented at least 80% of all profiles in each country. S. Typhimurium DT104 (n=1202) was differentiated into 28 different profile types. Simpson's D was at least 0.6 in all countries except in Austria and Italy. In both these countries over 74% of S. Typhimurium DT104 profiles were STYMXB.0013. Profile STYMXB.0061, was predominant in Denmark, Spain, Finland and England and Wales where it represented between 36% and 45% of profiles. Profile STYMXB.0001 represented nearly half of all profiles in Scotland and 23% in England and Wales. PFGE is proving useful for further discrimination within S. Enteritidis PT4 and S. Typhimurium DT104. Ascertainment of international outbreaks involving common serotypes and phage types may be increased by the timely pooling of PFGE profiles within a central database readily accessible to all participating countries.

Interleukin-1 gene polymorphisms and gastric cancer risk in a high-risk Italian population.

OBJECTIVES: Host genetic factors, including the IL1 gene cluster, play a key role in determining the long-term outcome of Helicobacter pylori infection. The aim of the study was to investigate the relationship between selected IL1 loci polymorphisms and gastric cancer risk in an Italian population. METHODS: In a case-control study we compared the IL1B-31 and IL1B+3954 biallelic and IL1RN pentaallelic variable number of tandem repeats (VNTR) polymorphisms in 185 gastric cancer patients and 546 controls randomly sampled from the general population of an area at high gastric cancer risk (Tuscany, Central Italy). RESULTS: Genotype frequencies of the IL1B-31 T/C, IL1B+3954 C/T, and IL1RN polymorphisms among our population controls were in Hardy-Weinberg equilibrium. In multivariate analyses, no increase in gastric cancer risk was observed for the IL1B-31*C- and IL1B+3954*T- carriers; a significant 50% increase emerged for IL1RN*2 allele carriers (OR = 1.49; 95% CI: 1.01-2.21). Analyses based on combined genotypes showed also that the association with IL1RN*2 allele was limited to two-variant allele carriers who were also homozygous for the IL1B-31*T allele (OR = 2.23; 95% CI: 1.18-4.23) with a statistically significant interaction between these two genotypes (p= 0.043). Haplotype analysis showed an increased risk for the haplotype IL1RN*2/IL1B-31*T. CONCLUSIONS: Our results suggest that host genetic factors (such as the IL1RN and the IL1B-31 polymorphisms) interact in the complex process of gastric carcinogenesis in this high-risk Italian population. Overall, this effect appears more modest than previously reported in other populations, supporting the hypothesis that other still-to-be-defined factors are important in gastric carcinogenesis. These findings might be due to a haplotype effect.

Helicobacter pylori duodenal colonization is a strong risk factor for the development of duodenal ulcer.

AIM: To test the hypothesis that duodenal colonization represents the final crucial step in the development of Helicobacter pylori related duodenal ulcer. METHODS: Patients with non-ulcer dyspepsia who had gastric colonization by H. pylori were included in the study. At baseline endoscopy, we evaluated the prevalence of duodenal colonization (culture, urease testing and histology), and cytotoxin-associated gene A status (polymerase chain reaction). No patients received eradication during 1 year follow-up. At this time, endoscopy was repeated and the incidence of duodenal ulcer was assessed. RESULTS: Among 181 patients completing follow-up, 53 (29%) had duodenal colonization: 72% of them were cytotoxin-associated gene A positive, versus 37% patients without duodenal colonization (P < 0.001). Duodenal ulcer developed in 12 (22.6%) patients with duodenal colonization and in two (1.6%) without duodenal colonization (odds ratio for duodenal ulcer: 6.29, 95% confidence intervals 2.44-17.45). The incidence of duodenal ulcer was similar among cytotoxin-associated gene A positive and cytotoxin-associated gene A negative subjects with duodenal colonization: 21.05% versus 26.6%. CONCLUSIONS: The assessment of duodenal colonization by H. pylori in patients with non-ulcer dyspepsia is strongly predictive for the subsequent development of duodenal ulcer and may help to stratify patients at risk for this disease.

Campylobacter fetus bacteremia in an immunocompromised patient: case report and review of the literature.

A 33-year-old woman underwent a liver transplantation and splenectomy in 1985 and had followed immunosuppressive therapy until 1995. Afterwards a non-Hodgkin lymphoma was diagnosed and chemotherapy was started. In January 2000, because of suspect transplantation rejection she was treated with steroid and immunosuppressive therapy. Fever occurred after two months and Cytomegalovirus (CMV) infection was diagnosed. Ganciclovir was started with clinical remission. In November 2000 fever recurred without clinical symptoms. Lymphoma recurrence was excluded and CMV was detected by PCR in several biological fluids. Blood cultures were positive for a bacterium that was identified as Campylobacter fetus. The patient was successfully treated with intravenous ciprofloxacin. For persistent CMV viremia therapy with gancyclovir was stopped and foscarnet was used (60mg/Kg/tid i.v. for two weeks). Bacteremia due to C. fetus is rare, occurring mainly in immunocompromised patients. In our patient the immunosuppressive therapy, chemotherapy for lymphoma and CMV infection had made the patient susceptible to bacteremia with this infrequently found bacterium. The clinical microbiologist should be aware of this infection in immunocompromised hosts.

Antibiotic resistance in Salmonella enterica serotypes Typhimurium, Enteritidis and Infantis from human infections, foodstuffs and farm animals in Italy.

The antimicrobial susceptibility of isolates of Salmonella enterica serotypes Typhimurium, Enteritidis, and Infantis isolated from humans, foodstuffs and farm animals in Italy between 1999 and 2001 was examined. All the isolates were susceptible to cefotaxime and ciprofloxacin, but high rates of resistance were observed for several other drugs, especially for S. Typhimurium. The rates of resistance and multiresistance were generally higher among animal and food isolates than in human strains; conversely, no significant difference was observed between animal and food isolates. Among S. Typhimurium, multiresistance was more common in bovine, poultry and rabbit strains than in swine isolates, and was rare in strains from pigeon. Resistance to trimethoprim sulphamethoxazole was mainly found in isolates of swine and human origin. This study confirms the role of livestock as a reservoir of drug-resistant Salmonella spp. and underlines the need for integrated surveillance systems of antibiotic resistance that consider isolates not only from human disease but also from the animal reservoirs and the food vehicles.