Human Campylobacter spp. infections in Italy.

PURPOSE: Campylobacter is a frequent cause of enteric infections with common antimicrobial resistance issues. The most recent reports of campylobacteriosis in Italy include data from 2013 to 2016. We aimed to provide national epidemiological and microbiological data on human Campylobacter infections in Italy during the period 2017-2021. METHODS: Data was collected from 19 Hospitals in 13 Italian Regions. Bacterial identification was performed by mass spectrometry. Antibiograms were determined with Etest or Kirby-Bauer (EUCAST criteria). RESULTS: In total, 5419 isolations of Campylobacter spp. were performed. The most common species were C. jejuni (n = 4535, 83.7%), followed by C. coli (n = 732, 13.5%) and C. fetus (n = 34, 0.6%). The mean age of patients was 34.61 years and 57.1% were males. Outpatients accounted for 54% of the cases detected. Campylobacter were isolated from faeces in 97.3% of cases and in 2.7% from blood. C. fetus was mostly isolated from blood (88.2% of cases). We tested for antimicrobial susceptibility 4627 isolates (85.4%). Resistance to ciprofloxacin and tetracyclines was 75.5% and 54.8%, respectively; resistance to erythromycin was 4.8%; clarithromycin 2% and azithromycin 2%. 50% of C. jejuni and C. coli were resistant to ≥ 2 antibiotics. Over the study period, resistance to ciprofloxacin and tetracyclines significantly decreased (p < 0.005), while resistance to macrolides remained stable. CONCLUSION: Campylobacter resistance to fluoroquinolones and tetracyclines in Italy is decreasing but is still high, while macrolides retain good activity.

Characterization of Verona Integron-Encoded Metallo-ß-Lactamase-Type Carbapenemase-Producing Escherichia coli Isolates Collected over a 16-Year Period in Bolzano (Northern Italy).

Multidrug-resistant Escherichia coli, particularly carbapenemase producers, are a major source of concern. This study aims to investigate the long-term epidemiology of Verona integron-encoded metallo-ß-lactamase (VIM)-producing E. coli in the health district of Bolzano, Northern Italy, by examining the phenotypic and genotypic characteristics of 26 isolates obtained during 2005-2020. Isolates were identified with matrix-assisted laser desorption/ionization time-of-flight, susceptibility testing was by Vitek 2, Sensititre, and Etest; carbapenemase activity was confirmed by Etest and Carbapenemase Inactivation Method (CIM) test; and the VIM-antigen was identified by the NG-Test CARBA 5. Genome sequencing was performed on an Illumina MiSeq platform. Carbapenem minimum inhibitory concentrations varied across methodologies, and overall category agreement between phenotypic methods was low. All 23 sequenced isolates contained blaVIM-1. Eleven (47.8%) isolates belonged to the clonal lineage ST131, with fimH30 being the most common subclone. In Bolzano ST131-fimH30 was present as early as 2005. While the ST131 clonal lineage predominated for the first 10 years, various clonal lineages were present, especially in subsequent years, indicating the concurrent circulation of multiple clonal lineages. Future efforts should focus on the implementation of surveillance methods, including genomic analysis, as well as the use of updated infection control strategies and antibiotic stewardship programs to prevent the spread of these carbapenem-resistant strains.

Current Uses and Future Perspectives of Genomic Technologies in Clinical Microbiology.

Recent advancements in sequencing technology and data analytics have led to a transformative era in pathogen detection and typing. These developments not only expedite the process, but also render it more cost-effective. Genomic analyses of infectious diseases are swiftly becoming the standard for pathogen analysis and control. Additionally, national surveillance systems can derive substantial benefits from genomic data, as they offer profound insights into pathogen epidemiology and the emergence of antimicrobial-resistant strains. Antimicrobial resistance (AMR) is a pressing global public health issue. While clinical laboratories have traditionally relied on culture-based antimicrobial susceptibility testing, the integration of genomic data into AMR analysis holds immense promise. Genomic-based AMR data can furnish swift, consistent, and highly accurate predictions of resistance phenotypes for specific strains or populations, all while contributing invaluable insights for surveillance. Moreover, genome sequencing assumes a pivotal role in the investigation of hospital outbreaks. It aids in the identification of infection sources, unveils genetic connections among isolates, and informs strategies for infection control. The One Health initiative, with its focus on the intricate interconnectedness of humans, animals, and the environment, seeks to develop comprehensive approaches for disease surveillance, control, and prevention. When integrated with epidemiological data from surveillance systems, genomic data can forecast the expansion of bacterial populations and species transmissions. Consequently, this provides profound insights into the evolution and genetic relationships of AMR in pathogens, hosts, and the environment.

Colonization of Residents and Staff of an Italian Long-Term Care Facility and an Adjacent Acute Care Hospital Geriatrics Unit by Multidrug-Resistant Bacteria.

In 2022, we undertook a point prevalence screening study for Enterobacterales with extended-spectrum ß-lactamases (ESBLs), high-level AmpC cephalosporinases and carbapenemases, and also methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) in a long-term care facility (LTCF) and the associated acute-care hospital Geriatrics unit in Bolzano, Northern Italy. Urine samples and rectal, inguinal, oropharyngeal, and nasal swabs were plated on selective agar plates. Metadata of the patients, including demographic data, were collected, and risk factors for colonization were determined. ESBL, AmpC, carbapenemase, and quinolone resistance genes were investigated by the HybriSpot 12 PCR AUTO System. The following colonization percentages by multidrug-resistant (MDR) bacteria have been found in LTCF residents: all MDR organisms, 59.5%; ESBL producers, 46.0% (mainly CTX-M-type enzymes); carbapenemase producers, 1.1% (one Klebsiella pneumoniae with KPC-type); MRSA, 4.5%; VRE, 6.7%. Colonization by MDR bacteria was 18.9% for LTCF staff and 45.0% for Geriatrics unit patients. Peripheral vascular disease, the presence of any medical device, cancer, and a Katz Index of 0 were significant risk factors for colonization of LTCF residents by MDR bacteria in univariate and/or multivariate regression analysis. To conclude, the ongoing widespread diffusion of MDR bacteria in the LTCF suggests that efforts should be strengthened on MDR screening, implementation of infection control strategies, and antibiotic stewardship programs targeting the unique aspects of LTCFs. ClinicalTrials.gov ID: 0530250-BZ Reg01 30/08/2022.

Time to reconsider moxifloxacin anti-anaerobic activity?

Large data on moxifloxacin activity on anaerobes are old. Moxifloxacin is often used for empiric therapy therefore the knowledge of current epidemiologic data is fundamental. We analyzed 69 anaerobic strains, from a recent multicenter Italian study, for moxifloxacin susceptibility. Using EUCAST criteria 81% of Bacteroides spp. and 48% of anaerobes other than Bacteroides were resistant to moxifloxacin. Using CLSI criteria moxifloxacin resistance rates decrease to 35% for all anaerobes, and to 41% for Bacteroides spp. We reported an alarming increase in moxifloxacin resistance among anaerobes in Italy.

Effect of Fluoroquinolone Use in Primary Care on the Development and Gradual Decay of Escherichia coli Resistance to Fluoroquinolones: A Matched Case-Control Study.

The reversibility of bacterial resistance to antibiotics is poorly understood. Therefore, the aim of this study was to determine, over a period of five years, the effect of fluoroquinolone (FQ) use in primary care on the development and gradual decay of Escherichia coli resistance to FQ. In this matched case−control study, we linked three sources of secondary data of the Health Service of the Autonomous Province of Bolzano, Italy. Cases were all those with an FQ-resistant E. coli (QREC)-positive culture from any site during a 2016 hospital stay. Data were analyzed using conditional logistic regression. A total of 409 cases were matched to 993 controls (FQ-sensitive E. coli) by the date of the first isolate. Patients taking one or more courses of FQ were at higher risk of QREC colonization/infection. The risk was highest during the first year after FQ was taken (OR 2.67, 95%CI 1.92−3.70, p < 0.0001), decreased during the second year (OR 1.54, 95%CI 1.09−2.17, p = 0.015) and became undetectable afterwards (OR 1.09, 95%CI 0.80−1.48, p = 0.997). In the first year, the risk of resistance was highest after greater cumulative exposure to FQs. Moreover, older age, male sex, longer hospital stays, chronic obstructive pulmonary disease (COPD) and diabetes mellitus were independent risk factors for QREC colonization/infection. A single FQ course significantly increases the risk of QREC colonization/infection for no less than two years. This risk is higher in cases of multiple courses, longer hospital stays, COPD and diabetes; in males; and in older patients. These findings may inform public campaigns and courses directed to prescribers to promote rational antibiotic use.

Anaerobic bloodstream infections in Italy (ITANAEROBY): A 5-year retrospective nationwide survey.

INTRODUCTION: A lack of updated data on the burden and profile of anaerobic bloodstream infections (ABIs) exists. We assessed the incidence of ABIs and trends in antimicrobial resistance in anaerobes isolated from blood in Italy. MATERIAL AND METHODS: We conducted a retrospective study on 17 Italian hospitals (2016-2020). Anaerobes isolated from blood culture and their in vitro susceptibility profiles (EUCAST-interpreted) were registered and analyzed. RESULTS: A total of 1960 ABIs were identified. The mean age of ABIs patients was 68.6 ± 18.5 years, 57.6% were males. The overall incidence rate of ABIs was 1.01 per 10.000 patient-days. Forty-seven% of ABIs occurred in medical wards, 17% in ICUs, 14% in surgical wards, 7% in hemato-oncology, 14% in outpatients. The three most common anti-anaerobic tested drugs were metronidazole (92%), clindamycin (89%) and amoxicillin/clavulanate (83%). The three most common isolated anaerobes were Bacteroides fragilis (n = 529), Cutibacterium acnes (n = 262) and Clostridium perfringens (n = 134). The lowest resistance rate (1.5%) was to carbapenems, whereas the highest rate (51%) was to penicillin. Clindamycin resistance was >20% for Bacteroides spp., Prevotella spp. and Clostridium spp. Metronidazole resistance was 9.2% after excluding C. acnes and Actinomyces spp. Bacteroides spp. showed an increased prevalence of clindamycin resistance through the study period: 19% in 2016, 33% in 2020 (p ≤ 0.001). CONCLUSIONS: Our data provide a comprehensive overview of the epidemiology of ABIs in Italy, filling a gap that has existed since 1995. Caution is needed when clindamycin is used as empirical anti-anaerobic drug.

Impact of Prior Antibiotic Use in Primary Care on Escherichia coli Resistance to Third Generation Cephalosporins: A Case-Control Study.

Research is lacking on the reversibility of antimicrobial resistance (AMR). Thus, we aimed to determine the influence of previous antibiotic use on the development and decay over time of third generation cephalosporin (3GC)-resistance of E. coli. Using the database of hospital laboratories of the Autonomous Province of Bolzano/Bozen (Italy), anonymously linked to the database of outpatient pharmaceutical prescriptions and the hospital discharge record database, this matched case-control study was conducted including as cases all those who have had a positive culture from any site for 3GC resistant E. coli (3GCREC) during a 2016 hospital stay. Data were analyzed by conditional logistic regression. 244 cases were matched to 1553 controls by the date of the first isolate. Male sex (OR 1.49, 95% CI 1.10-2.01), older age (OR 1.11, 95% CI 1.02-1.21), the number of different antibiotics taken in the previous five years (OR 1.20, 95% CI 1.08-1.33), at least one antibiotic prescription in the previous year (OR 1.92, 95% CI 1.36-2.71), and the diagnosis of diabetes (OR 1.57, 95% CI 1.08-2.30) were independent risk factors for 3GCREC colonization/infection. Patients who last received an antibiotic prescription two years or three to five years before hospitalization showed non-significant differences with controls (OR 0.97, 95% CI 0.68-1.38 and OR 0.85, 95% CI 0.59-1.24), compared to an OR of 1.92 (95% CI 1.36-2.71) in those receiving antibiotics in the year preceding hospitalization. The effect of previous antibiotic use on 3GC-resistance of E. coli is highest after greater cumulative exposure to any antibiotic as well as to 3GCs and in the first 12 months after antibiotics are taken and then decreases progressively.

Country Income Is Only One of the Tiles: The Global Journey of Antimicrobial Resistance among Humans, Animals, and Environment.

Antimicrobial resistance (AMR) is one of the most complex global health challenges today: decades of overuse and misuse in human medicine, animal health, agriculture, and dispersion into the environment have produced the dire consequence of infections to become progressively untreatable. Infection control and prevention (IPC) procedures, the reduction of overuse, and the misuse of antimicrobials in human and veterinary medicine are the cornerstones required to prevent the spreading of resistant bacteria. Purified drinking water and strongly improved sanitation even in remote areas would prevent the pollution from inadequate treatment of industrial, residential, and farm waste, as all these situations are expanding the resistome in the environment. The One Health concept addresses the interconnected relationships between human, animal, and environmental health as a whole: several countries and international agencies have now included a One Health Approach within their action plans to address AMR. Improved antimicrobial usage, coupled with regulation and policy, as well as integrated surveillance, infection control and prevention, along with antimicrobial stewardship, sanitation, and animal husbandry should all be integrated parts of any new action plan targeted to tackle AMR on the Earth. Since AMR is found in bacteria from humans, animals, and in the environment, we briefly summarize herein the current concepts of One Health as a global challenge to enable the continued use of antibiotics.

Recommendations for the surveillance of multidrug-resistant bacteria in Italian long-term care facilities by the GLISTer working group of the Italian Association of Clinical Microbiologists (AMCLI).

Long-term care facilities (LTCFs) are an important reservoir of multidrug-resistant organisms (MDROs). Colonization of LTCF residents by MDROs is generally higher in Italy compared to other European countries. The present review by the working group for the study of infections in LTCFs (GLISTer) of the Italian Association of Clinical Microbiologists (AMCLI) aims to propose criteria for a laboratory-based surveillance of MDROs in Italian LTCFs.We recommend the adhesion to three levels of laboratory-based MDROs surveillance in LTCFs: i) mandatory MDRO surveillance by cumulative retrospective analysis of antimicrobial susceptibility data, obtained as part of routine care of clinical specimens. ii) strongly recommended surveillance by active rectal swab cultures or molecular screening to determine colonization with carbapenemase-producing Enterobacterales, should a resident be proven infected. iii) voluntary surveillance by prospective MDRO surveys, mainly based on point prevalence colonization studies, allowing to determine the MDROs baseline prevalence in the facility.Laboratory-based surveillance of MDROs in LTCFs is aimed at providing useful epidemiological information to healthcare providers operating in the facility, but it is only effective if the collected data are used for infection prevention and control purposes, targeting the peculiar aspects of LTCFs.

Colonization of long-term care facility residents in three Italian Provinces by multidrug-resistant bacteria.

Background: Rationale and aims of the study were to compare colonization frequencies with MDR bacteria isolated from LTCF residents in three different Northern Italian regions, to investigate risk factors for colonization and the genotypic characteristics of isolates. The screening included Enterobacteriaceae expressing extended-spectrum ß-lactamases (ESßLs) and high-level AmpC cephalosporinases, carbapenemase-producing Enterobacteriaceae, Pseudomonas aeruginosa or Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Methods: Urine samples and rectal, inguinal, oropharyngeal and nasal swabs were plated on selective agar; resistance genes were sought by PCR and sequencing. Demographic and clinical data were collected. Results: Among the LTCF residents, 75.0% (78/104), 69.4% (84/121) and 66.1% (76/115) were colonized with at least one of the target organisms in LTCFs located in Milan, Piacenza and Bolzano, respectively. ESßL producers (60.5, 66.1 and 53.0%) were highly predominant, mainly belonging to Escherichia coli expressing CTX-M group-1 enzymes. Carbapenemase-producing enterobacteria were found in 7.6, 0.0 and 1.6% of residents; carbapemenase-producing P. aeruginosa and A. baumannii were also detected. Colonization by MRSA (24.0, 5.7 and 14.8%) and VRE (20.2, 0.8 and 0.8%) was highly variable. Several risk factors for colonization by ESßL-producing Enterobacteriaceae and MRSA were found and compared among LTCFs in the three Provinces. Colonization differences among the enrolled LTCFs can be partially explained by variation in risk factors, resident populations and staff/resident ratios, applied hygiene measures and especially the local antibiotic resistance epidemiology. Conclusions: The widespread diffusion of MDR bacteria in LTCFs within three Italian Provinces confirms that LTCFs are an important reservoir of MDR organisms in Italy and suggests that future efforts should focus on MDR screening, improved implementation of infection control strategies and antibiotic stewardship programs targeting the complex aspects of LTCFs.

Colonization of residents and staff of an Italian long-term care facility and an adjacent acute care hospital geriatric unit by multidrug-resistant bacteria.

In 2016, we undertook a point prevalence screening study for Enterobacteriaceae with extended-spectrum ß-lactamases (ESBLs), high-level AmpC cephalosporinases and carbapenemases, and also methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE) in a long-term care facility (LTCF) and the associated acute care hospital geriatric unit in Bolzano, Northern Italy. Urine samples and rectal, inguinal, oropharyngeal and nasal swabs were plated on selective agars. Demographic data were collected. ESBL and carbapenemase genes were sought by PCR. We found the following colonization percentages with multidrug-resistant (MDR) bacteria in 2016 in LTCF residents: all MDR organisms, 66.1%; ESBL producers, 53.0%; carbapenemase-producers, 1.7%; MRSA, 14.8%; VRE, 0.8%. Colonization by all MDR bacteria was 19.4% for LTCF staff and 26.0% for geriatric unit patients. PCR showed that 80.3% of Escherichia coli isolates from LTCF residents, all E. coli isolates from LTCF staff, 62.5% and 100% of Klebsiella pneumoniae from LTCF residents and geriatric unit patients, respectively, had a blaCTX-M-type gene. All carbapenemase-producing Enterobacteriaceae harboured a blaVIM-type gene. To conclude, the ongoing widespread diffusion of MDR bacteria in the LTCF suggests that efforts should be strengthened on MDR screening, implementation of infection control strategies and antibiotic stewardship programs targeting the unique aspects of LTCFs.

Predominance of Clostridium difficile 027 during a five-year period in Bolzano, Northern Italy.

Toxigenic Clostridium difficile is responsible for antibiotic-associated diarrhoea and other diseases. The increasing frequency and severity is attributed to highly-virulent ribotypes such as 027. The aim of the study was to collect epidemiological and molecular data for C. difficile isolates during 2009-2013 in the Central Hospital of Bolzano, Northern Italy. Stool samples from inpatients of the Bolzano Central Hospital were screened for toxins A and B, and C. difficile was cultured and tested for antibiotic susceptibility. PCRs were performed for genes of toxin A, toxin B, binary toxin and ribotyping. During the period 2009-13 from 320 patients (9% of patients tested) at least one stool sample proved positive for C. difficile toxins, and incidences for all hospital inpatients per 10,000 patient days (per 1,000 admissions) varied between 2.2 (1.5) and 4.3 (3.0). Out of 138 isolates (43% of total isolates were studied), 24 different ribotypes were identified. Isolates with ribotype 027 were predominant (38%), followed by 018 (13%) and 607 (10%). Whereas for ribotype 018 a significant decrease was seen during the five-year period, ribotype 027 increased significantly from 0% in 2009 to 64% in 2012, decreasing then to 10% in 2013. Isolates were sensitive to metronidazole and vancomycin, whereas isolates of the three major ribotypes were resistant to moxifloxacin. Our data indicates a significant change in C. difficile incidence rates and ribotype frequencies during the five-year period in the Central Hospital in Bolzano.

Review on colonization of residents and staff in Italian long-term care facilities by multidrug-resistant bacteria compared with other European countries.

BACKGROUND: Rates of colonization and infection with multidrug-resistant (MDR) bacteria are increasing worldwide, in both acute care hospitals and long-term care facilities (LTCFs). Italy has one of the highest prevalence of MDR bacteria in European countries, especially with regard to methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum ß-lactamase (ESBL) or carbapenemase producing Enterobacteriaceae (CPE). METHOD: Review of studies on colonization by MDR bacteria from Italian LTCFs, risk factors for colonization and molecular characteristics of surveillance and clinical isolates, compared with other European countries. RESULTS: High variability of MDR colonization has been reported within and especially between European countries. Only a few surveillance studies have been performed in Italian LTCFs; these show MRSA colonization prevalence of 7.8-38.7 % for residents and 5.2-7.0 % for staff members, ESBL prevalence of 49.0-64.0 % for residents and 5.2-14.5 % for staff and prevalence of CPE of 1.0-6.3 % for residents and 0.0-1.5 % for staff. In Italian LTCFs, as well as in other European countries, the most prevalent ESBLs from surveillance or clinical Escherichia coli isolates were found to be CTX-M-type enzymes, particularly CTX-M-15, expressed by the pandemic ST131 clonal group; this lineage also expresses carbapenemase genes of the blaVIM and blaKPC types. Various risk factors for colonization of residents by MDR bacteria were identified. CONCLUSIONS: The limited data from Italian LTCFs confirms these settings as important reservoirs for MDR organisms, allowing important considerations regarding the infection risk by these organisms. Nevertheless, more extended and countrywide screening studies for MDR colonization in Italian LTCFs are required. To promote further studies of various microbiological aspects related to LTCFs, the Association of Italian Clinical Microbiologists (Associazione Microbiologi Clinici Italiani; AMCLI) in 2016 has set up a new Working Group for the Study of Infections in LTCFs (Gruppo di Lavoro per lo Studio delle Infezioni nelle Residenze Sanitarie Assistite e Strutture Territoriali assimilabili; GLISTer), consisting of Clinical Microbiologists represented by the authors of this review article.

Occurrence of Clostridium difficile infections due to PCR ribotype 027 in Bucharest, Romania.

INTRODUCTION: Little is known about prevailing ribotypes of Clostridium difficile infection in Romania where CDI is not a mandatory notifiable disease. METHODOLOGY: We studied 64 non-duplicate C. difficile isolates from patients hospitalised at the National Institute of Infectious Diseases, Bucharest, Romania between March 2011 and March 2012. RESULTS: Sixty-three of the 64 C. difficile isolates produced toxins A and B whereas 44 (69%) isolates produced a binary toxin. Ribotype 027 accounted for 43 (68%) of the 63 toxigenic strains. The remaining 20 isolates belonged to ribotypes 018 (n = 9), 012 (n = 3), and, with one isolate each, 014, 031, 081, 416, 433, 500, 507 and PR03035 (new ribotype). Information on hospital mortality was available for 62 of the 64 patients; among these 62 cases, 4 (6.4%) ended fatal. Recurrence was documented for 11 (18.3%) of the 60 patients for whom this information was available. Multilocus variable-number tandem repeat analysis of the 43 isolates of ribotype 027 yielded a unique cluster for the Romanian isolates when compared to Austrian or Italian isolates. CONCLUSION: Our findings sustain the hypothesis of a recent emerged outbreak of C. difficile PCR ribotype 027 infections in the area of Bucharest.

Antibiotic susceptibility and molecular epidemiology of Panton-Valentine leukocidin-positive meticillin-resistant Staphylococcus aureus: An international survey.

The antibiotic susceptibility and molecular epidemiology of Panton-Valentine leukocidin (PVL)-positive meticillin-resistant Staphylococcus aureus (MRSA) isolates reported from 17 countries in the Americas, Europe and, Australia-Asia were analysed. Among a total of 3236 non-duplicate isolates, the lowest susceptibility was observed to erythromycin in all regions. Susceptibility to ciprofloxacin showed large variation (25%, 75% and 84% in the Americas, Europe and Australia-Asia, respectively). Two vancomycin-intermediate PVL-positive MRSA isolates were reported, one from Hong Kong and the other from The Netherlands. Resistance to trimethoprim/sulfamethoxazole and linezolid was <1%. Among 1798 MRSA isolates from 13 countries that were tested for the requested 10 non-ß-lactam antibiotics, 49.4% were multisusceptible. However, multiresistant isolates (resistant to at least three classes of non-ß-lactam antibiotics) were reported from all regions. Sequence type 30 (ST30) was reported worldwide, whereas ST80 and ST93 were exclusive to Europe and Australia, respectively. USA300 and related clones (ST8) are progressively replacing the ST80 clone in several European countries. Eight major clusters were discriminated by multilocus variable-number tandem repeat assay (MLVA), showing a certain geographic specificity. PVL-positive MRSA isolates frequently remain multisusceptible to non-ß-lactam agents, but multiresistance is already prevalent in all regions. Surveillance of MRSA susceptibility patterns should be monitored to provide clinicians with the most current information regarding changes in resistance patterns.

Changes in colonization of residents and staff of a long-term care facility and an adjacent acute-care hospital geriatric unit by multidrug-resistant bacteria over a four-year period.

BACKGROUND: In 2012 we undertook a screening study for Enterobacteriaceae with extended-spectrum ß-lactamases (ESBLs), derepressed or acquired high-level AmpC cephalosporinases, and metallo-ß-lactamases (MBLs), and also methicillin-resistant Staphylococcus aureus (MRSA), in a long-term care facility (LTCF1) and the associated acute care hospital geriatric ward in Bolzano, northern Italy. The study followed up an initial survey carried out in LTCF1 in 2008. For comparison, screening in 2012 was extended to a second LTCF. METHODS: Urine samples and rectal, inguinal, oropharyngeal, and nasal swabs were plated on selective agars. Isolates were typed by pulsed-field gel electrophoresis. Resistance genes and Escherichia coli belonging to ST131 were sought by PCR. Demographic data were collected. RESULTS: Fewer residents of LTCF1 were colonized with multidrug-resistant (MDR) bacteria in 2012: all MDR organisms, 53.8% vs 74.8% in 2008; ESBL producers, 49.0% vs 64.0% in 2008; MRSA, 13.2% vs 38.7% in 2008; only 2 MBL-producers were isolated in 2012 vs 8 in 2008. Colonization of staff in LTCF1 by MDR bacteria had also decreased (overall 10.5% in 2012 vs 27.5% in 2008). Changed case mixes and risk factors, together with strengthened hygiene measures probably underlie the changes. Colonization proportions in 2012 in LTCF2 were similar to those in LTCF1. By contrast there was no significant change in the proportion of patients colonized by MDR bacteria in the geriatric ward (22.2% in 2008 vs 22.7% in 2012). CONCLUSIONS: A significant decrease in the proportions of staff and residents of an LTCF colonized by MDR bacteria was observed over a 4-y interval.

Carbapenemase-producing Enterobacteriaceae during 2011-12 in the Bolzano area (Northern Italy): increasing diversity in a low-endemicity setting.

The recent (2011-2012) distribution of carbapenemase determinants in Enterobacteriaceae was studied in the Bolzano area (Northern Italy). Low proportions of carbapenemase producers were found for Escherichia coli (0.2%), Citrobacter freundii (1.1%), Klebsiella pneumoniae (1.3%), Klebsiella oxytoca (1.6%) and Enterobacter spp (1.8%). Although VIM-1 remained the most common carbapenemase, the emergence of K. pneumoniae producing KPC-3 and of E. coli producing OXA-48 was observed. Of concern is the spread of the hyperepidemic strains E. coli ST131 producing VIM-1 and K. pneumoniae ST258 producing KPC-3. Low essential and category agreements between the reference broth microdilution and commercial methods were observed for carbapenems.

High clonal heterogeneity of Panton-Valentine leukocidin-positive meticillin-resistant Staphylococcus aureus strains from skin and soft-tissue infections in the Province of Bolzano, Northern Italy.

Panton-Valentine leukocidin (PVL)-positive community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) isolates are widespread in many countries, with varying distribution and epidemiology. The aim of this study was to characterise 10 PVL-positive MRSA isolates collected during February 2010 to January 2011 from skin and soft-tissue infections in the North Italian Province of Bolzano. Accessory gene regulator (agr) typing, staphylococcal cassette chromosome mec (SCCmec) typing, staphylococcal protein A (spa) gene typing, multilocus sequence typing, toxin gene profiling, polymerase chain reaction for type I arginine catabolic mobile element (ACME) and antimicrobial resistance typing were applied to the isolates. Eight different CA-MRSA clones were identified, including ST30-IVc, ST772-V, ST80-IVc, ST5-IVc, ST88-IVa, ST93-IVa, ST8-IVc and the type I ACME-positive ST8-IVa. The high heterogeneity of PVL-positive MRSA probably reflects the introduction of different clones by international travellers or immigrants.