Group B streptococci (GBS) strains evading molecular diagnostics showed novel chromosomal deletions encompassing the CAMP-factor (cfb) encoding gene.

A highly conserved fragment adjacent to the cfb gene encoding the CAMP factor is the target of PCR-based molecular diagnostic systems for the identification of S. agalactiae (group B streptococci (GBS)). Six PCR-negative, culture-positive GBS strains were whole genome sequenced to assess why they escaped molecular diagnostics. GBS strains did not constitute a clonal cluster and presented variably sized chromosomal deletions (from 7 to 33 kb) which always included the cfb gene, a finding never described before. GBS strains that escape molecular diagnostics are considered rare; however, they can cause false-negative results using molecular diagnostics alone, affecting medical decisions.

Severe Streptococcus equi Subspecies zooepidemicus Outbreak from Unpasteurized Dairy Product Consumption, Italy.

During November 2021-May 2022, we identified 37 clinical cases of Streptococcus equi subspecies zooepidemicus infections in central Italy. Epidemiologic investigations and whole-genome sequencing showed unpasteurized fresh dairy products were the outbreak source. Early diagnosis by using sequencing technology prevented the spread of life-threatening S. equi subsp. zooepidemicus infections.

Neutralizing Antibodies against SARS-CoV-2 Beta and Omicron Variants Inhibition Comparison after BNT162b2 mRNA Booster Doses with a New PETIA sVNT Assay.

BACKGROUND: Monitoring antibody response following SARS-CoV-2 vaccination is strategic, and neutralizing antibodies represent the gold standard. The neutralizing response to Beta and Omicron VOCs was evaluated versus the gold standard by a new commercial automated assay. METHODS: Serum samples from 100 healthcare workers from the Fondazione Policlinico Universitario Campus Biomedico and the Pescara Hospital were collected. IgG levels were determined by chemiluminescent immunoassay (Abbott Laboratories, Wiesbaden, Germany) and serum neutralization assay as the gold standard. Moreover, a new commercial immunoassay, the PETIA test Nab (SGM, Rome, Italy), was used for neutralization evaluation. Statistical analysis was performed with R software, version 3.6.0. RESULTS: Anti-SARS-CoV-2 IgG titers decayed during the first ninety days after the vaccine second dose. The following booster dose significantly (p < 0.001) increased IgG levels. A correlation between IgG expression and neutralizing activity modulation was found with a significant increase after the second and the third booster dose (p < 0.05. Compared to the Beta variant of the virus, the Omicron VOC was associated with a significantly larger quantity of IgG antibodies needed to achieve the same degree of neutralization. The best Nab test cutoff for high neutralization titer (≥1:80) was set for both Beta and Omicron variants. CONCLUSION: This study correlates vaccine-induced IgG expression and neutralizing activity using a new PETIA assay, suggesting its usefulness for SARS-CoV2 infection management.

Multicenter Italian Study on "In Vitro Activities" of Isavuconazole, Voriconazole, Amphotericin B, and Caspofungin for Aspergillus Species: Comparison between SensititreTM YeastOneTM and MIC Test Strip.

In this study the activity of Isavuconazole, Voriconazole, Amphotericin B, and Caspofungin against 224 clinical isolates of Aspergillus spp. originating from seven Italian hospitals, was comparatively evaluated with two commercial antifungal susceptibility tests (AST): SensititreTM YeastOneTM (SYO) and MIC Test Strip. More attention was focused on Isavuconazole activity, given the new introduction of the drug in widely distributed antifungal susceptibilities methods in the clinical microbiology lab. The minimum inhibitory concentrations of antifungal drug that can inhibit the growth of pathogen by 90% (MIC90) for Isavuconazole detected by SYO were 0.5, 1, 0.25, and 2 µg/mL for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, and Aspergillus niger, respectively, whilst they were 0.25, 0.25, 0.5, and 0.75 µg/mL by MIC Test Strip. Essential agreement between the two tested methods for Isavuconazole is 70% for all the species tested, 75.7% for A. fumigatus, 45.2% for A. flavus, 90.6% for A. terreus, and 40% for A. niger. Although the tested strains do not express any phenotypic resistance, MIC results were quite different if tested with microdilution broth or gradient agar method. This is the first Italian multicenter report on Isavuconazole MIC obtained employing the widely used SensititreTM Yeast OneTM (SYO) and MIC Test Strip on clinical isolates of Aspergillus.

Molecular Characterization by Whole-Genome Sequencing of Clinical and Environmental Serratia marcescens Strains Isolated during an Outbreak in a Neonatal Intensive Care Unit (NICU).

The whole-genome sequencing (WGS) of eighteen S. marcescens clinical strains isolated from 18 newborns hospitalized in the Neonatal Intensive Care Unit (NICU) at Pescara Public Hospital, Italy, was compared with that of S. marcescens isolated from cradles surfaces in the same ward. The identical antibiotic resistance genes (ARGs) and virulence factors were found in both clinical and environmental S. marcescens strains. The aac(6')-Ic, tetA(41), blaSRT-3, adeFGH, rsmA, and PBP3 (D350N) genes were identified in all strains. The SRT-3 enzyme, which exhibited 10 amino acid substitutions with respect to SST-1, the constitutive AmpC ß-lactamase in S. marcescens, was partially purified and tested against some ß-lactams. It showed a good activity against cefazolin. Both clinical and environmental S. marcescens strains exhibited susceptibility to all antibiotics tested, with the exception of amoxicillin/clavulanate.

In Vitro Activity of Sulbactam-Durlobactam against Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates: A Multicentre Report from Italy.

In the present study, the in vitro activity of the sulbactam-durlobactam (SUL-DUR) combination was evaluated against 141 carbapenem-resistant A. baumannii (CRAb) clinical strains collected from six Italian laboratories. Over half (54.6%) of these isolates were resistant to colistin. The SUL-DUR combination was active against these CRAb isolates with MIC50 and MIC90 values of 0.5 mg/L and 4 mg/L, respectively. Only eleven isolates were resistant to SUL-DUR with MIC values ranging from 8 to 128 mg/L. The SUL-DUR resistant A. baumannii exhibited several antimicrobial resistance genes (ARGs) such as blaOXA-20, blaOXA-58, blaOXA-66, blaADC-25, aac(6')-Ib3 and aac(6')-Ib-cr and mutations in gyrA (S81L) and parC (V104I, D105E). However, in these isolates, mutations Q488K and Y528H were found in PBP3. Different determinants were also identified in these CRAb isolates, including adeABC, adeFGH, adeIJK, abeS, abaQ and abaR, which encode multidrug efflux pumps associated with resistance to multiple antibacterial agents. This is the first report on the antimicrobial activity of SUL-DUR against carbapenem-resistant A. baumannii isolates selected from multiple regions in Italy.

Whole-Genome Sequencing of ST2 A. baumannii Causing Bloodstream Infections in COVID-19 Patients.

A total of 43 A. baumannii strains, isolated from 43 patients affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and by bacterial sepsis, were analyzed by antimicrobial susceptibility testing. All strains were resistant to almost three different classes of antibiotics, including carbapenems and colistin. The whole-genome sequencing (WGS) of eight selected A. baumannii isolates showed the presence of different insertion sequences (ISs), such as ISAba13, ISAba26, IS26, ISVsa3, ISEc29, IS6100 and IS17, giving to A. baumannii a high ability to capture and mobilize antibiotic resistance genes. Resistance to carbapenems is mainly mediated by the presence of OXA-23, OXA-66 and OXA-82 oxacillinases belonging to OXA-51-like enzymes. The presence of AmpC cephalosporinase, ADC-25, was identified in all A. baumannii. The pathogenicity of A. baumannii was exacerbated by the presence of several virulence factors. The multi-locus sequence typing (MLST) analysis showed that all strains belong to sequence type 2 (ST) international clone.

Molecular Identification of New Cases of Human Dirofilariosis (Dirofilaria repens) in Italy.

(1) Dirofilariosis is a vector-borne parasitic disease mainly in domestic and wild carnivores caused by Dirofilaria (Noctiella) repens, which is endemic in many countries of the Old World, and D. immitis, which has a worldwide distribution. In recent years, an increase in the number of human cases has been reported, suggesting that dirofilariosis is an emergent zoonosis. Here, we describe further cases (N = 8), observed in Central Italy during the years 2018-2019. (2) Molecular diagnosis was performed on: (i) live worms extracted from ocular conjunctiva, cheek, and calf muscle; (ii) histological sections of surgically removed nodules from parenchymal lung, coccyx, and breast. (3) Sequence analysis (650-bp) of the mitochondrial cytochrome oxidase subunit I gene (mtDNA cox1) showed a match of 100% with the sequences of D. repens previously deposited in GenBank. ELISA test to detect IgG against filarial antigens was performed on four patients' sera and resulted positive in two patients who showed ocular and subcutaneous dirofilariosis, respectively. Microfilariae have been never detected in the peripheral blood of the patients. (4) The occurrence of N = 8 new cases of human D. repens-infections observed in a two-year period suggests an increased circulation of the parasite in Italy. Therefore, dirofilariosis should be included in differential diagnosis in patients presenting subcutaneous and/or pulmonary nodules. Molecular diagnosis of the etiological agents is fundamental. Specific serological diagnosis needs to be improved in future research work.

A large food-borne outbreak of campylobacteriosis in kindergartens and primary schools in Pescara, Italy, May-June 2018.

Introduction. In May-June 2018, an outbreak of campylobacteriosis involved students and school staff from kindergartens and primary schools in Pescara, southern Italy.Aim. We present details of the epidemiological and microbiological investigation, and the findings of the analytical study, as well as the implemented control measures.Methodology. To identify possible risk factors associated with the observed outbreak, a case control study was conducted using a questionnaire to collect information on the date of symptoms onset, type and duration of symptoms, type of healthcare contact, school attendance, and food items consumed at school lunches during the presumed days of exposure. Attack rates were calculated for each date and school. Logistic regression models were used to estimate the odds ratios of being a case and the odds of illness by food items consumed, respectively. Moreover, we carried out a comparative genomic analysis using whole genome multilocus sequence typing (wgMLST) of Campylobacter jejuni strains isolated during the outbreak investigation to identify the source of the outbreak.Results. Overall, 222 probable cases from 21 schools were identified, and C. jejuni was successfully isolated from 60 patients. The meals in the schools involved were provided by two cooking centres managed by a joint venture between two food companies. Environmental and food sampling, epidemiological and microbiological analyses, as well as a case control study with 176 cases and 62 controls from the same schools were performed to identify the source of the outbreak. The highest attack rate was recorded among those having lunch at school on 29 May (7.8 %), and the most likely exposure was 'caciotta' cheese (odds ratio 2.40, 95 % confidence interval 1.10-5.26, P=0.028). C. jejuni was isolated from the cheese, and wgMLST showed that the human and cheese isolates belonged to the same genomic cluster, confirming that the cheese was the vehicle of the infection.Conclusion. It is plausible that a failure of the pasteurization process contributed to the contamination of the cheese batches. Timely suspension of the catering service and summer closure of the schools prevented further spread.

A "One-Health" approach for diagnosis and molecular characterization of SARS-CoV-2 in Italy.

The current pandemic is caused by a novel coronavirus (CoV) called SARS-CoV-2 (species Severe acute respiratory syndrome-related coronavirus, subgenus Sarbecovirus, genus Betacoronavirus, family Coronaviridae). In Italy, up to the 2nd of April 2020, overall 139,422 confirmed cases and 17,669 deaths have been notified, while 26,491 people have recovered. Besides the overloading of hospitals, another issue to face was the capacity to perform thousands of tests per day. In this perspective, to support the National Health Care System and to minimize the impact of this rapidly spreading virus, the Italian Ministry of Health involved the Istituti Zooprofilattici Sperimentali (IZSs), Veterinary Public Health Institutes, in the diagnosis of SARS-CoV-2 by testing human samples. The Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise is currently testing more than 600 samples per day and performing whole genome sequencing from positive samples. Sequence analysis of these samples suggested that different viral variants may be circulating in Italy, and so in Abruzzo region. CoVs, and related diseases, are well known to veterinarians since decades. The experience that veterinarians operating within the Public Health system gained in the control and characterization of previous health issues of livestock and poultry including avian flu, bluetongue, foot and mouth disease, responsible for huge economic losses, is certainly of great help to minimize the impact of this global crisis.

Control of Gram-negative multi-drug resistant microorganisms in an Italian ICU: Rapid decline as a result of a multifaceted intervention, including conservative use of antibiotics.

BACKGROUND: Gram-negative Multi-Drug-Resistant Organisms (GNMDROs) cause an increasing burden of disease in Intensive Care Units (ICUs). We deployed a multifaceted intervention to control selection and transmission of GNMDROs and to estimate at which rate GNMDROs would decline with our interventional bundle. METHODS: Interventions implemented in 2015: in-ward Antimicrobial-Stewardship-Program for appropriate management of antimicrobial prescription; infection monitoring with nasal/rectal swabs and repeated procalcitonin assays; 24 h microbiological support (since 2016); prevention of catheter-related infections, VAPs and in-ward GNMDROs transmission; education of ICU personnel. In May 2017, epidemiological, clinical and microbiological data were collected and retrospectively analyzed. Rates of resistance in Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii, as well as percentages of resistance among all Gram-negative bacteria were compared during the study period. RESULTS: Of 668 patients, at least one isolate was obtained from 399 patients. The proportions of patients with infection and with Gram-negative isolates were even across the 5 semesters (p = 0.8). For Klebsiella pneumoniae, the number of strains resistant to carbapenems fell from 94% to 6% (p < 0.001). Significant drops were also observed for Pseudomonas aeruginosa and Acinetobacter baumannii. Percentages of resistance for all Gram-negative isolates fell from 91% to 13% (p < 0.0001). The reduction in antibiotic prescription translated in a considerable reduction of pharmacy costs. Multivariate models confirmed that the hospitalization semester was the most relevant independent predictor of resistance among Gram-negative bacteria. CONCLUSIONS: Our experience provides further evidence that a multi-faceted intervention, aimed to reduce selection and transmission of GNMDROs with efficient microbiological support, may yield remarkable results in a short time interval.

Cure of recurring Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae septic shock episodes due to complicated soft tissue infection using a ceftazidime and avibactam-based regimen: a case report.

BACKGROUND: Infections caused by multidrug-resistant Enterobacteriaceae are hard to treat and life-threatening due to reduced therapeutic options. Systemic infections caused by Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae strains have increased in many European regions, becoming frequent in many clinical settings, and are associated with high mortality. The co-formulation of ceftazidime, a third-generation cephalosporin, with avibactam, a new suicide inhibitor beta-lactamase inhibitor able to block most Klebsiella pneumoniae carbapenemases, has been recently licensed, with promising results in patients with limited or absent therapeutic options. Little is known, however, as to the efficacy of such a combination in patients with soft tissue infections caused by multidrug-resistant Klebsiella pneumoniae carbapenemase-producing strains of Klebsiella pneumoniae. CASE PRESENTATION: A Caucasian 53-year-old man with paraplegia suffered multiple vertebral fractures due to a car crash. He was treated with external fixators that became infected early after insertion and were repeatedly and inefficiently treated with multiple antibiotics. He suffered repeated septic episodes caused by Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae strains with a multidrug-resistant profile. Meropenem, tigecycline, and colistin combinations allowed only temporary improvements, but septic shock episodes recurred, in spite of removal of infected external fixators. After approval of pre-marketing prescription by our local Ethics Committee, full clinical resolution was obtained with a compassionate treatment using meropenem and ceftazidime/avibactam in combination for 16 days. CONCLUSIONS: Our experience provides additional evidence that ceftazidime/avibactam, possibly in combination with meropenem rescued by avibactam, may be an efficacious treatment option also for complicated skin and soft tissue infections caused by multidrug-resistant strains of Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae.

Ceftolozane-tazobactam and Fosfomycin for rescue treatment of otogenous meningitis caused by XDR Pseudomonas aeruginosa: Case report and review of the literature.

Extensively drug resistant Pseudomonas aeruginosa (XDR-PA) strains with limited or absent residual antimicrobial susceptibility cause a growing burden of difficult-to treat infections. Treatment options are even more limited for patients with central nervous system (CNS) involvement, as colistin-based regimens are hampered by poor blood brain barrier penetration, being often associated with insufficient clinical and microbiological success. New treatment options are awaited, but evidence from prospective evidence-based evaluations is still lacking. Here we report a case of breakthrough otogenous meningitis caused by XDR-PA in a young patient treated with meropenem and colistin for XDR-PA bloodstream infection and pneumonia after a car-crash polytrauma. The patient was treated with off-label, high-dose ceftolozane-tazobactam and high-dose fosfomycin after characterization of CNS XDR-PA isolates, with rapid clinical and microbiological resolution of meningitis. Our experience, although based on a single case, lands preliminary support to the concept that rescue regimens including ceftolozane-tazobactam and fosfomycin may be considered for XDR-PA CNS infections in patients without alternative therapeutic options.

Multidrug-resistant infections in long-term care facilities: extended-spectrum ß-lactamase-producing Enterobacteriaceae and hypervirulent antibiotic resistant Clostridium difficile.

Infections due to multidrug-resistant (MDR) organisms in long-term care facilities (LTCFs) residents constitute a public health concern. This multicenter study investigated the frequency of ESBL-producing pathogens and MDR Clostridium difficile in clinical specimens from LTCF residents in Italy. During October 2014-March 2015, all urine and diarrheic fecal samples from LTCF residents (≥65 years) with suspected urinary tract infection or C. difficile infection, respectively, received for diagnosis by 4 hospital laboratories located in different cities were analyzed. Antibiotic susceptibility testing, characterization of resistance genes, and molecular typing of pathogens were performed. Of 806 urine cultures collected from 626 residents at 44 different LTCFs, 492 were positive for microbial infection. Of these, 158 were positive for at least an ESBL-producing Enterobacteriaceae species (32.1%), with Escherichia coli as the most frequent ESBL pathogen (23.4%) followed by Klebsiella pneumoniae (4.5%). Furthermore, 4 carbapenemase producers (0.8%) (1 E. coli with VIM-1and 3 K. pneumoniae with KPC-3) were detected. The CTX-M-15 type ESBL predominated in both E. coli (71.3%) and K. pneumoniae (77.3%). Most E. coli isolates (82.6%) belonged to the ST131/H30 clone/subclone. For K. pneumoniae, ST307 and ST15 were frequent (31.8% and 22.7%, respectively), but isolates harboring blaKPC-3 belonged to CC258. Of 136 diarrheic fecal samples collected from 111 residents at 26 different LTCFs, 21 (15.4%) were positive for toxigenic C. difficile; of these, 13 (62%) were MDR (resistant to 3 or more antimicrobial agents of different classes). The predominant C. difficile polymerase chain reaction ribotype was 356/607 (42.9%), followed by 018, 449, and 078 (14% each). Public health efforts are needed to contain the diffusion of CTX-M-producing Enterobacteriaceae and MDR C. difficile in LTCF settings.

Invasive anisakiasis by the parasite Anisakis pegreffii (Nematoda: Anisakidae): diagnosis by real-time PCR hydrolysis probe system and immunoblotting assay.

BACKGROUND: Anisakiasis is a fish-borne zoonosis caused by Anisakis spp. larvae. One challenging issue in the diagnosis of anisakiasis is the molecular detection of the etiological agent even at very low quantity, such as in gastric or intestinal biopsy and granulomas. Aims of this study were: 1) to identify three new cases of invasive anisakiasis, by a species-specific Real-time PCR probe assay; 2) to detect immune response of the patients against the pathogen. METHODS: Parasite DNA was extracted from parasites removed in the three patients. The identification of larvae removed at gastric and intestinal level from two patients was first obtained by sequence analysis of mtDNA cox2 and EF1 α-1 of nDNA genes. This was not possible in the third patient, because of the very low DNA quantity obtained from a single one histological section of a surgically removed granuloma. Real-time PCR species-specific hydrolysis probe system, based on mtDNA cox2 gene, was performed on parasites tissue of the three cases. IgE, IgG4 and IgG immune response against antigens A. pegreffii by Immunoblotting assay was also studied. RESULTS: According to the mtDNA cox2 and the EF1 α - 1 nDNA sequence analysis, the larvae from stomach and intestine of two patients were assigned to A. pegreffii. The Real-time PCR primers/probe system, showed a fluorescent signal at 510 nm for A. pegreffii, in all the three cases. In Immunoblotting assay, patient CC1 showed IgE, IgG4 reactivity against Ani s 13-like and Ani s 7-like; patient CC2 revealed only IgG reactivity against Ani s 13-like and Ani s 7-like; while, the third patient showed IgE and IgG reactivity against Ani s 13-like, Ani s 7-like and Ani s 1-like. CONCLUSION: The Real-time PCR assay, a more sensitive method than direct DNA sequencing for the accurate and rapid identification of etiological agent of human anisakiasis, was successfully assessed for the first time. The study also highlights the importance to use both molecular and immunological tools in the diagnosis of human anisakiasis, in order to increase our knowledge about the pathological findings and immune response related to the infection by zoonotic species of the genus Anisakis.

Recurring septic shock in a patient with blunt abdominal and pelvic trauma: how mandatory is source control surgery?: a case report.

BACKGROUND: In critically ill patients with colonization/infection of multidrug-resistant organisms, source control surgery is one of the major determinants of clinical success. In more complex cases, the use of different tools for sepsis management may allow survival until complete source control. CASE PRESENTATION: A 42-year-old white man presented with traumatic hemorrhagic shock. Unstable pelvic fractures led to emergency stabilization surgery. Fever ensued with diarrhea, followed by septic shock. Two weeks later, an abdominal computed tomography scan revealed suprapubic and ischiatic abscesses at surgical sites, as well as dilated bowel. Debridement of both surgical sites, performed with vacuum-assisted closure therapy, yielded isolates of carbapenem and colistin-resistant Klebsiella pneumoniae. Antibiotic treatment was de-escalated after 21 days; 4 days later fever, leukocytosis, hypotension and acute renal failure relapsed. Blood purification techniques were started, for the removal of endotoxin and inflammatory mediators, with sequential hemodialysis. Clinical improvement ensued; blood cultures yielded Candida albicans and multidrug-resistant Acinetobacter baumannii; panresistant carbapenemase-producing Klebsiella pneumoniae grew from wound swabs. In spite of shock reversal, our patient remained febrile, with diarrhea. Control blood cultures yielded Candida albicans, Acinetobacter baumannii and carbapenem-resistant Klebsiella pneumoniae. His abdominal pain increased, paralleled by a right flank palpable mass. Colonoscopy revealed patchy serpiginous ulcers. At exploratory laparotomy, an inflammatory post-traumatic pseudotumor of his right colon was removed. Blood cultures turned negative after surgery. Septic shock, however, relapsed 4 days later. A blood purification cycle was repeated and combination antimicrobial therapy continued. Surgical wounds and blood cultures were persistently positive for carbapenem-resistant Klebsiella pneumoniae. Removal of pelvic synthesis media was therefore anticipated. Three weeks later, clinical, microbiological, and biochemical evidence of infection resolved. CONCLUSIONS: High quality intensive assistance for sepsis episodes needs a clear plan of cure, aimed to complete infection source control, in a complex multidisciplinary interplay of specialists and intensive care physicians.

Candida species isolated from different body sites and their antifungal susceptibility pattern: Cross-analysis of Candida albicans and Candida glabrata biofilms.

Candida species are regular commensal in humans, but-especially in immunocompromised patients-they represent opportunistic pathogens giving rise to systemic infection. The aim of the present work was to isolate and characterize for their antifungal profile Candida species from different body sites and to analyze the biofilms produced by C. albicans and C. glabrata isolates. Eighty-one strains of Candida species from 77 patients were identified. Epidemiological study showed that the most isolated species were C. albicans (44), C. glabrata (13) and C. parapsilosis (13) mainly from Hematology, Infectious Diseases, Medicine, Neonatology and Oncology Divisions, the majority of the biological samples were swabs (44) and blood cultures (16). The analysis of the biofilm formation was performed at 24 and 48-hours comparing resistant and susceptible strains of C. albicans to resistant and susceptible strains of C. glabrata. Candida albicans has a greater ability to form biofilm compared to C. glabrata, both in the susceptible and resistant strains reaching maturity after 24 hours with a complex structure composed of blastospores, pseudohyphae, and hyphae embedded in a matrix. On the contrary, C. glabrata biofilm was composed exclusively of blastospores that in the resistant strain, after 24 hours, were organized in a compact multilayer different to the discontinuous structure observed in the susceptible analyzed strains. In conclusion, the increasing of the incidence of Candida species infection together with their emerging drug resistance also related to the biofilm forming capability underline the need to monitor their distribution and susceptibility patterns for improving the surveillance and for a correct management of the infection.

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.