Distribution of human Cytomegalovirus gB genotypes in samples from pediatric patients in Parma during the period 1995-2003

Background. Human Cytomegalovirus (HCMV) infection is a leading cause of developmental disability and late neurological sequelae in children. Several literature data indicate that HCMV pericapsidic glycoprotein B (gB) is highly immunogenic and is involved in virus-cell interaction.The gB gene has hypervariable regions producing four genotypes (gB1, gB2, gB3, gB4); however, the correlation between gB genotypes and HCMV infection outcome remains unclear. Objectives. The main goal of this study was that of evaluating the distribution of HCMV gB genotypes in samples from pediatric population in Parma with congenital, perinatal or post-natal infections, in order to find a correlation between viral gB genotypes and the clinical outcome of the infection. Study design. Forty eight urine samples, selected between 1999 and 2003 and stored at -80°C, underwent DNA extraction, nested PCR amplification of a gB gene region and restriction polymorphism analysis (RFLP). Results. The gB genotypes distribution in the considered pediatric population was as follows: gB1 was the most diffused (45.83%) followed by gB2 (22.92%), gB3 (16.67%) and gB4 (14.58%). Conclusions. In the considered population, gB1 was the most represented genotype and was often found in congenital and perinatal symptomatic infections, as well as in post-natal, asymptomatic infections

Active surveillance for carbapenemaseproducing Klebsiella pneumoniae and correlation with infection in subjects attending an Italian tertiary-care hospital: a 7-year retrospective study

Objectives The distribution of carbapenemase-producing Klebsiella pneumoniae (CPKP) phenotypes and genotypes in samples collected during 2011–2018 was evaluated. The association between patients with CPKP-positive rectal swab and those with CPKP infection, as well as the overall analysis of CPKP-infected patients, was performed. Setting The study was performed in a tertiary-care hospital located in Northern Italy. Participants Two groups were considered: 22 939 ‘atrisk’ patients submitted to active surveillance for CPKP detection in rectal swabs/stools and 1094 CPKP-infected patients in which CPKP was detected in samples other than rectal swabs. Results CPKP-positive rectal swabs were detected in 5% (1150/22 939). A CPKP infection was revealed in 3.1% (719/22 939) of patients: 582 with CPKP-positive rectal swab (50.6% of the 1150 CPKP-positive rectal swabs) and 137 with CPKP-negative rectal swab. The 49.4% (568/1150) of the patients with CPKP-positive rectal swab were carriers. The overall frequency of CPKP-positive patients (carriers and infected) was almost constant from 2012 to 2016 (excluding the 2015 peak) and then increased in 2017–2018. blaKPC was predominant followed by blaVIM. No difference was observed in the frequency of CPKP-positive rectal swab patients among the different material groups. Among the targeted carbapenemase genes, blaVIM was more significantly detected from urine than from other samples. Conclusions The high prevalence of carriers without evidence of infection, representing a potential reservoir of CPKP, suggests to maintain the guard about this problem, emphasising the importance of active surveillance for timely detection and separation of carriers, activation of contact precautions and antibiotic treatment guidance on suspicion of infection

MIGHTEE-HI: HI galaxy properties in the large scale structure environment at z ∼ 0.37 from a stacking experiment

We present the first measurement of HI mass of star-forming galaxies in different large scale structure environments from a blind survey at z ∼ 0.37. In particular, we carry out a spectral line stacking analysis considering 2875 spectra of colour-selected star-forming galaxies undetected in HI at 0.23 < z < 0.49 in the COSMOS field, extracted from the MIGHTEE-HI Early Science datacubes, acquired with the MeerKAT radio telescope. We stack galaxies belonging to different subsamples depending on three different definitions of large scale structure environment: local galaxy overdensity, position inside the host dark matter halo (central, satellite, or isolated), and cosmic web type (field, filament, or knot). We first stack the full star-forming galaxy sample and find a robust HI detection yielding an average galaxy HI mass of MHI = (8.12 ± 0.75) × 109 M⊙ at ∼11.8σ. Next, we investigate the different subsamples finding a negligible difference in MHI as a function of the galaxy overdensity. We report an HI excess compared to the full sample in satellite galaxies (MHI = (11.31 ± 1.22) × 109, at ∼10.2σ) and in filaments (MHI = (11.62 ± 0.90) × 109. Conversely, we report non-detections for the central and knot galaxies subsamples, which appear to be HI-deficient. We find the same qualitative results also when stacking in units of HI fraction (fHI). We conclude that the HI amount in star-forming galaxies at the studied redshifts correlates with the large scale structure environment

MIGHTEE-HI: HI galaxy properties in the large scale structure environment at z~0.37 from a stacking experiment

We present the first measurement of HI mass of star-forming galaxies in different large scale structure environments from a blind survey at $z\sim 0.37$. In particular, we carry out a spectral line stacking analysis considering $2875$ spectra of colour-selected star-forming galaxies undetected in HI at $0.23 < z < 0.49$ in the COSMOS field, extracted from the MIGHTEE-HI Early Science datacubes, acquired with the MeerKAT radio telescope. We stack galaxies belonging to different subsamples depending on three different definitions of large scale structure environment: local galaxy overdensity, position inside the host dark matter halo (central, satellite, or isolated), and cosmic web type (field, filament, or knot). We first stack the full star-forming galaxy sample and find a robust HI detection yielding an average galaxy HI mass of $M_{\rm HI}=(8.12\pm 0.75)\times 10^9\, {\rm M}_\odot$ at $\sim 11.8\sigma$. Next, we investigate the different subsamples finding a negligible difference in $M_{\rm HI}$ as a function of the galaxy overdensity. We report an HI excess compared to the full sample in satellite galaxies ($M_{\rm HI}=(11.31\pm1.22)\times 10^9$, at $\sim 10.2 \sigma$) and in filaments ($M_{\rm HI}=(11.62\pm 0.90)\times 10^9$. Conversely, we report non-detections for the central and knot galaxies subsamples, which appear to be HI-deficient. We find the same qualitative results also when stacking in units of HI fraction ($f_{\rm HI}$). We conclude that the HI amount in star-forming galaxies at the studied redshifts correlates with the large scale structure environment.Comment: Accepted for publication in MNRAS. 15 figures, 3 table

MIGHTEE-Hi: Evolution of Hi Scaling Relations of Star-forming Galaxies at z &lt; 0.5*

We present the first measurements of H I galaxy scaling relations from a blind survey at z > 0.15. We perform spectral stacking of 9023 spectra of star-forming galaxies undetected in H I at 0.23 < z < 0.49, extracted from MIGHTEE-H I Early Science data cubes, acquired with the MeerKAT radio telescope. We stack galaxies in bins of galaxy properties (stellar mass M *, star formation rateSFR, and specific star formation rate sSFR, with sSFR ≡ M */SFR), obtaining ≳5σ detections in most cases, the strongest H I-stacking detections to date in this redshift range. With these detections, we are able to measure scaling relations in the probed redshift interval, finding evidence for a moderate evolution from the median redshift of our sample z med ~ 0.37 to z ~ 0. In particular, low-M * galaxies ( {\mathrm{log}}_{10}({M}_{* }/{M}_{\odot })\sim 9 )experienceastrongHIdepletion( 0.5dexinlog10(MHI/M⊙) ), while massive galaxies ( {\mathrm{log}}_{10}({M}_{* }/{M}_{\odot })\sim 11$ ) keep their H I mass nearly unchanged. When looking at the star formation activity, highly star-forming galaxies evolve significantly in M H I (f H I, where f H I ≡ M H I/M *) at fixed SFR (sSFR), while at the lowest probed SFR (sSFR) the scaling relations show no evolution. These findings suggest a scenario in which low-M * galaxies have experienced a strong H I depletion during the last ~5 Gyr, while massive galaxies have undergone a significant H I replenishment through some accretion mechanism, possibly minor mergers. Interestingly, our results are in good agreement with the predictions of the SIMBA simulation. We conclude that this work sets novel important observational constraints on galaxy scaling relations

Distribution of human Cytomegalovirus gB genotypes in samples from pediatric patients in Parma during the period 1995-2003

Background. Human Cytomegalovirus (HCMV) infection is a leading cause of developmental disability and late neurological sequelae in children. Several literature data indicate that HCMV pericapsidic glycoprotein B (gB) is highly immunogenic and is involved in virus-cell interaction.The gB gene has hypervariable regions producing four genotypes (gB1, gB2, gB3, gB4); however, the correlation between gB genotypes and HCMV infection outcome remains unclear. Objectives. The main goal of this study was that of evaluating the distribution of HCMV gB genotypes in samples from pediatric population in Parma with congenital, perinatal or post-natal infections, in order to find a correlation between viral gB genotypes and the clinical outcome of the infection. Study design. Forty eight urine samples, selected between 1999 and 2003 and stored at -80°C, underwent DNA extraction, nested PCR amplification of a gB gene region and restriction polymorphism analysis (RFLP). Results. The gB genotypes distribution in the considered pediatric population was as follows: gB1 was the most diffused (45.83%) followed by gB2 (22.92%), gB3 (16.67%) and gB4 (14.58%). Conclusions. In the considered population, gB1 was the most represented genotype and was often found in congenital and perinatal symptomatic infections, as well as in post-natal, asymptomatic infections

An innovative application of MALDI-TOF MS in clinical virology

Introduction. Virus detection and/or identification is traditionally performed using cell culture, electron microscopy and antigen or nucleic acid detection. In this study, Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS), commonly used in clinical microbiology, was developed and tested as an innovative tool to be applied to virus identification by using two different approaches. Materials and Methods. In the first approach, human polioviruses were selected as a model to evaluate the ability of MALDI-TOF MS to identify specific viral protein to be used as biomarkers of purified virus particles, followed by the serotypes identification. To this aim the Sabin reference strains (I, II, III) were firstly analysed and, subsequently, the results were then confirmed by a blind application of the assay to clinically isolated strains. In the second approach, a protein profiles library was newly create to discriminate between uninfected and respiratory virus infected cell cultures after a viral proteins enrichment method. The library was built using different reference strains after an extensive modification of the MALDI- TOF MS pre-processing, MSP creation, subtyping MSP creation and identification default parameters setting. Results. The very efficient technique adopted to obtain highly purified poliovirus allowed us to discriminate viral protein peaks from uninfected cells peaks and to detect specific poliovirus protein biomarkers. Moreover, MALDI-TOF MS analysis applied to the three Sabin poliovirus serotypes revealed characteristic peak profiles for each of them showing three independent clusters for the three serotypes. After a proper statistical investigation, the VP4 was used as a potential biomarker to identify poliovirus strains at the serotype level. On the bases of VP4 all clinical isolates were identified at the serotype level. In the second approach, the spectra generated from virus infected cell cultures revealed the presence of some different peaks not overlap- ping those of uninfected cell cultures for all the reference virus infected cell cultures. The parameters for the creation of the Main Spectrum Profile (MSP) for each of the reference virus infected cell cultures were set on the basis of these peaks. The obtained MSP spectra were used to create a new respiratory viruses library in our Bruker Daltonics database in order to blind identify viruses isolated from biological samples aster a cell culture step. The spectra obtained by 58 additional cultured strains correctly match with the new database demonstrating its reliability. Discussion and Conclusions. In conclusion, this study could be considered a starting point for further evolutions of the developed system, since the differences observed comparing the spectra obtained from virus infected cell culture suggest the possibility to apply these approaches to the identification of other viruses including other picornavirus such as enterovirus and coxsackievirus and viruses responsible for respiratory infections, as well as to viral agents causing infections of other body sites