Aggregatibacter aphrophilus and Eikenella corrodens: a case of brain abscess.

We report a case of a 26-year-old female who developed a brain abscess that was strongly suspected to be caused by Staphylococcus epidermidis, A. aphrophilus, and E. corrodens species. In general, A. aphrophilus and E. corrodens, members of the HACEK group (Haemophilus spp., Aggregatibacter spp., C. hominis, E. corrodens, and K. kingae), have been associated with the development of endocarditis, meningitis, sinusitis, otitis media, pneumonia, osteomyelitis, peritonitis, and wound infections. Cerebral abscesses are a rare manifestation of these bacteria; only a few cases are described in the literature, generally related to the diffusion of these organisms through the bloodstream after a dental procedure or a heart disease. Our case is unique because the rarity of the infection site appeared apparently in absence of risk factors. The patient underwent surgery to drain the abscess and was subsequently put on intravenous antibiotic treatment with ceftriaxone, vancomycin, and metronidazole. After 6 months, brain imaging revealed that the lesion had disappeared. The patient achieved excellent results with this approach.

Helicobacter pylori and Epstein-Barr Virus Co-Infection in Gastric Disease: What Is the Correlation with p53 Mutation, Genes Methylation and Microsatellite Instability in a Cohort of Sicilian Population?

Genetic predisposition, environmental factors, and infectious agents interact in the development of gastric diseases. Helicobacter pylori (Hp) and Epstein-Barr virus (EBV) infection has recently been shown to be correlated with these diseases. A cross-sectional study was performed on 100 hospitalized Italian patients with and without gastric diseases. The patients were stratified into four groups. Significant methylation status differences among CDH1, DAPK, COX2, hMLH1 and CDKN2A were observed for coinfected (Hp-EBV group) patients; particularly, a significant presence of COX2 (p = 0.0179) was observed. For microsatellite instability, minor stability was described in the Hp-HBV group (69.23%, p = 0.0456). Finally, for p53 mutation in the EBV group, exon 6 was, significantly, most frequent in comparison to others (p = 0.0124), and in the Hp-EBV group exon 8 was, significantly, most frequent in comparison to others (p < 0.0001). A significant positive relationship was found between patients with infection (Hp, EBV or both) and p53 mutation (rho = 0.383, p = 0.0001), methylation status (rho = 0.432, p < 0.0001) and microsatellite instability (rho = 0.285, p = 0.004). Finally, we observed among infection and methylation status, microsatellite instability, and p53 mutation a significant positive relationship only between infection and methylation status (OR = 3.78, p = 0.0075) and infection and p53 mutation (OR = 6.21, p = 0.0082). According to our analysis, gastric disease in the Sicilian population has different pathways depending on the presence of various factors, including infectious agents such as Hp and EBV and genetic factors of the subject.

Co-existence of virulence factors and antibiotic resistance in new Klebsiella pneumoniae clones emerging in south of Italy.

BACKGROUND: Endemic presence of Klebsiella pneumoniae resistant to carbapenem in Italy has been due principally to the clonal expansion of CC258 isolates; however, recent studies suggest an ongoing epidemiological change in this geographical area. METHODS: 50 K. pneumoniae strains, 25 carbapenem-resistant (CR-Kp) and 25 susceptible (CS-Kp), collected from march 2014 to march 2016 at the Laboratory of Bacteriology of the Paolo Giaccone Polyclinic University hospital of Palermo, Italy, were characterized for antibiotic susceptibility and fully sequenced by next generation sequencing (NGS) for the in silico analysis of resistome, virulome, multi-locus sequence typing (MLST) and core single nucleotide polymorphism (SNP) genotypes RESULTS: MLST in silico analysis of CR-Kp showed that 52% of isolates belonged to CC258, followed by ST395 (12%), ST307 (12%), ST392 (8%), ST348 (8%), ST405 (4%) and ST101 (4%). In the CS-Kp group, the most represented isolate was ST405 (20%), followed by ST392 and ST15 (12%), ST395, ST307 and ST1727 (8%). The in silico ß-lactamase analysis of the CR-Kp group showed that the most detected gene was blaSHV (100%), followed by blaTEM (92%), blaKPC (88%), blaOXA (88%) and blaCTX-M (32%). The virulome analysis detected mrk operon in all studied isolates, and wzi-2 was found in three CR-Kp isolates (12%). Furthermore, the distribution of virulence genes encoding for the yersiniabactin system, its receptor fyuA and the aerobactin system did not show significant distribution differences between CR-Kp and CS-Kp, whereas the Klebsiella ferrous iron uptake system (kfuA, kfuB and kfuC genes), the two-component system kvgAS and the microcin E495 were significantly (p < 0.05) prevalent in the CS-Kp group compared to the CR-Kp group. Core SNP genotyping, correlating with the MLST data, allowed greater strain tracking and discrimination than MLST analysis. CONCLUSIONS: Our data support the idea that an epidemiological change is ongoing in the Palermo area (Sicily, Italy). In addition, our analysis revealed the co-existence of antibiotic resistance and virulence factors in CR-Kp isolates; this characteristic should be considered for future genomic surveillance studies.

Cocirculation of Hajj and non-Hajj strains among serogroup W meningococci in Italy, 2000 to 2016.

In Italy, B and C are the predominant serogroups among meningococci causing invasive diseases. Nevertheless, in the period from 2013 to 2016, an increase in serogroup W Neisseria meningitidis (MenW) was observed. This study intends to define the main characteristics of 63 MenW isolates responsible of invasive meningococcal disease (IMD) in Italy from 2000 to 2016. We performed whole genome sequencing on bacterial isolates or single gene sequencing on culture-negative samples to evaluate molecular heterogeneity. Our main finding was the cocirculation of the Hajj and the South American sublineages belonging to MenW/clonal complex (cc)11, which gradually surpassed the MenW/cc22 in Italy. All MenW/cc11 isolates were fully susceptible to cefotaxime, ceftriaxone, ciprofloxacin, penicillin G and rifampicin. We identified the full-length NadA protein variant 2/3, present in all the MenW/cc11. We also identified the fHbp variant 1, which we found exclusively in the MenW/cc11/Hajj sublineage. Concern about the epidemic potential of MenW/cc11 has increased worldwide since the year 2000. Continued surveillance, supported by genomic characterisation, allows high-resolution tracking of pathogen dissemination and the detection of epidemic-associated strains.

Bactibilia in diseases of the biliary tract and pancreatic gland in patients older than 80 years: a STROBE-retrospective cohort study in a teaching hospital in Italy.

Bile is a lipid-rich sterile solution produced in the liver that can be infected resulting in bactibilia. A higher incidence of postoperative infectious complications has been seen in patients with bactibilia. Recently, gram-negative bacteria have been linked to a tumor-associated inflammatory status. This study is a retrospective cohort study of 39 patients, who are over 80 years of age only (53.85% males and 46.15% females), hospitalized with diseases of the biliopancreatic system in one teaching hospital in Italy from January 2011 to December 2012 with a follow-up of 5 years. The most common biliary diseases after surgery were pancreatic head cancer (p < 0.0001) and gallbladder cancer (p = 0.0051), while the most common bacteria in the bile were E. coli (p = 0.0180) and Pseudomonas spp. (p < 0.0001). Uni- and multivariate linear correlation analysis revealed that patients with pancreatic head cancer had low survival times compared to patients with other diseases. Moreover, the bacterium type was a positive predictor of survival time compared to other variables. Our data confirm E. coli as a pathogen in patients with gallbladder and pancreatic cancer. Although the influence of bactibilia in developing surgical complications is limited, we consider that its composition is crucial to properly address the antibiotic treatment in biliary tract infections, especially in the elderly.

Genotyping and Antifungal Susceptibility of Dipodascus capitatus Isolated in a Neonatal Intensive Care Unit of a Sicilian Hospital.

In August 2015, Dipodascus capitatus was isolated from two patients admitted to the neonatal intensive care unit. Nosocomial acquisition of the fungus was suspected and epidemiological studies were undertaken. The patients were simultaneously hospitalized, and the comparison of the two isolates by two independent molecular typing methods have confirmed clonal dissemination of a single strain of D. capitatus. Antimicrobial susceptibility testing was useful for identifying the appropriated antifungal therapy in micafungin. To our knowledge these are the first described cases of neonatal D. capitatus infection and also the first report of successful treatment by micafungin.

Imported and Indigenous cases of Invasive Meningocococcal Disease W:P1.5,2:F1-1: ST-11 in migrants' reception centers. Italy, June-November 2014.

We report about three unliked cases of meningococcal meningitis caused by the ST-11/ET-37 strain of Neisseria meningitidis serogroup W. Two of the three cases, detected in Sicily on June and July 2014, were migrants from Mali and Eritrea. The third case was a fatal meningitis occurred on November 2014 in a 37 years old man, working in an immigrant center in Calabria. This report suggests that tetravalent conjugate vaccines (ACYW) should be actively offered to the staff of migrants' reception centers.

Biofilm production in Staphylococcus epidermidis strains, isolated from the skin of hospitalized patients: genetic and phenotypic characteristics.

A major virulence factor of Staphylococcus epidermidis is its ability to form biofilms, permitting it to adhere to a surface and, in turn, to form a mucoid layer on polymer surfaces. Multiple factors have been found to influence bacterial attachment. Currently, this bacterium is commonly associated with hospital infections as a consequence of its ability to colonize, albeit accidentally, medical devices. This study investigated the genetic and phenotypic formation of biofilm in 105 S. epidermidis strains isolated from the skin of hospitalized patients. Fifty-eight of these patients were positive for the mecA gene (MRSE) and 47 were found to be negative (MSSE). Genetic characterizations were performed for the detection of the mecA, icaADBC, atlE, aap, bhp, IS256 and agr groups by PCR. Biofilm production was examined by culturing the strains in TBS medium and TBS with 0.5 and 1% respectively of glucose, and a semiquantitative assay on tissue culture plates was used. Although a molecular analysis estimate of detailed biofilm formation is costly in terms of time and complexity, a semiquantitative assay can be proposed as a rapid and cheap diagnostic method for initial screening to discover virulent strains. We confirmed a close correlation between genetic and phenotypic characteristics, highlighting the fact that, when S. epidermidis isolates were cultured in TSB with 1% of glucose, an increase in biofilm production was observed, as confirmed by positivity for the ica locus by molecular analysis.

Molecular epidemiology of Acinetobacter baumannii in Iran: endemic and epidemic spread of multiresistant isolates.

OBJECTIVES: We examined the molecular epidemiology of Acinetobacter baumannii clinical isolates from two cities (Tehran and Tabriz) of Iran. METHODS: DiversiLab repetitive extragenic palindromic PCR (rep-PCR), multilocus sequence typing and sequence group multiplex PCR were performed. The presence of resistance mechanisms including metallo-ß-lactamases, extended-spectrum ß-lactamases, OXA carbapenemases, aminoglycoside-modifying enzymes and RNA methylases was also investigated. RESULTS: DiversiLab rep-PCR identified 11 clusters and 11 singleton isolates. Twelve sequence types (STs), including six novel types, were identified. Sequence groups (SGs) 1-3 as well as five additional banding patterns were detected by multiplex PCR. A local outbreak in a general hospital in Tabriz with an SG1/ST2 profile was identified. Isolates of international clone II showed the highest prevalence and the most heterogeneous combination of resistance determinants. CONCLUSIONS: Several different multiresistant strains of A. baumannii were shown to circulate in Iran. The selection and spread of the SG1/ST2 clone might have been favoured by the acquisition of resistance genes in the absence of adequate infection control measures.

Molecular epidemiology of tuberculosis in Sicily, Italy: what has changed after a decade?

BACKGROUND: We aimed to investigate the molecular epidemiology of Mycobacterium tuberculosis complex (MTBC) isolates in the province of Palermo, Sicily, Italy, by characterizing 183 isolates identified in the years 2004-2012. A comparison with 104 MTBC strains identified in the same geographic area in the years 1994-2000 was also carried out. METHODS: One hundred eighty-three MTBC isolates identified in Palermo, Italy, in the years 2004-2012 were analyzed by spoligotyping and the 24 mycobacterial interspersed repetitive unit (MIRU)-variable-number tandem-repeat (VNTR) method typing. Susceptibility testing to streptomycin, isoniazid, rifampin and ethambutol was also performed. Furthermore, the spoligotyping dataset obtained from 104 MTBC isolates identified from 1994 to 2000 was reanalyzed. Distribution into lineages and clustering of isolates in the two periods was compared. RESULTS: One hundred seventy-seven out of the 183 isolates of MTBC submitted to molecular typing were fully characterized. Of these, 108 were from Italian-born and 69 from foreign-born individuals. Eleven different lineages and 35 families-subfamilies were identified with the most represented lineages being Haarlem (26.5%), T (19.2%), LAM (13.6%) and S (8.5%). Except for the Haarlem lineage, where isolates from foreign-born patients were overrepresented, the distribution of isolates in the families belonging to the Euro-American clone reflected the proportions of the two subpopulations. A total of 27 (15.2%) strains were clustered and three clusters were mixed. Approximately 25% of the 183 MTBC isolates under study proved to be resistant to at least one antiTB drug, with only three isolates categorized as multidrug resistant (MDR). When MTBC isolates identified in the years 1994-2000 were reanalyzed, lineages T (30.8%), LAM (29.8%), Haarlem (16.3%) and S (13.5%) proved to be predominant. No MTBC isolates belonging to CAM, U, CAS, Turkish and Ural lineages were identified. CONCLUSIONS: A wide heterogeneity was detected among the MTBC strains isolated in the years 2004-2012. Six lineages were not present among the isolates of the period 1994-2000. Comparison between distribution of lineages in the two consecutive periods depicts rapid and deep changes in the TB epidemiology in Palermo, Italy. An universal and continued laboratory-based surveillance of TB in Sicily is required.