Genome characterization of a Klebsiella pneumoniae co-producing OXA-181 and KPC-121 resistant to ceftazidime/avibactam, meropenem/vaborbactam, imipenem/relebactam and cefiderocol isolated from a critically ill patient

Objectives: : Carbapenemase-producing Enterobacterales (CPE) represent a public health concern. The limited antimicrobial options against CPE have led to the development of novel antimicrobial molecules. In the present study, we characterized the genetic determinants associated with the resistance to cef tazidime/avibactam (CAZ-AVI), meropenem/vaborbactam (MER-VAB), imipenem/relebactam (IMI-REL) and cefiderocol (CFD) in a carbapenemase-producing Klebsiella pneumoniae strain isolated from a critically ill patient. Methods: : Genomic DNA was sequenced using Illumina iSeq 100 and Minion Oxford Nanopore plat forms. Assemblies were performed with a de novo approach using short-read, hybrid and long-lead as sembly approaches. Final assembly was manually curated and carefully verified. Circular elements were screened for antimicrobial-resistance genes, porins, virulence factors and prophage regions. Results: : KPC-Kp (KPC-producing Klebsiella pneumoniae) BO743 was resistant to all novel β-lactams including CAZ-AVI, MER-VAB, IMI-REL and CFD. The genome of strain BO743 is composed of a single chromosome of 5 347 606 bp and three circular plasmids of 363 634 bp (pBO743-363Kb), 120 290 bp (pBO743-120Kb) and 54 339 bp (pBO743-54Kb). Sequence analysis demonstrated that KPC-Kp BO743 co harboured blaOXA-181 and novel blaKPC-121 located, respectively, on the pBO743-54Kb and pBO743-120Kb plasmids. KPC-121 differed by a serine insertion at position 181 than KPC-3. Conclusion: : The description of the genome of KPC-Kp cross-resistant to novel βL-βLICs and cefiderocol reveals the presence of numerous antimicrobial resistance genes including blaOXA-181 and novel variant blaKPC-121. The characterization of this multidrug-resistant phenotype provides evidence that needs further attention and monitoring of such MDR clinical isolate

Respiratory Syncytial Virus Infections in Infants Affected by Primary Immunodeficiency

Primary immunodeficiencies are rare inherited disorders that may lead to frequent and often severe acute respiratory infections. Respiratory syncytial virus (RSV) is one of the most frequent pathogens during early infancy and the infection is more severe in immunocompromised infants than in healthy infants, as a result of impaired T- and B-cell immune response unable to efficaciously neutralize viral replication, with subsequent increased viral shedding and potentially lethal lower respiratory tract infection. Several authors have reported a severe clinical course after RSV infections in infants and children with primary and acquired immunodeficiencies. Environmental prophylaxis is essential in order to reduce the infection during the epidemic season in hospitalized immunocompromised infants. Prophylaxis with palivizumab, a humanized monoclonal antibody against the RSV F protein, is currently recommended in high-risk infants born prematurely, with chronic lung disease or congenital heart disease. Currently however the prophylaxis is not routinely recommended in infants with primary immunodeficiency, although some authors propose the extension of prophylaxis to this high risk population

Real-Life Assessment of the Ability of an Ultraviolet C Lamp (SanificaAria 200, Beghelli) to Inactivate Airborne Microorganisms in a Healthcare Environment

Airborne-mediated microbial diseases represent one of the major challenges to public health. Ultraviolet C radiation (UVC) is among the different sanitation techniques useful to reduce the risk of infection in healthcare facilities. Previous studies about the germicidal activity of UVC were mainly performed in artificial settings or in vitro models. This study aimed to assess the sanitizing effectiveness of a UVC device (SanificaAria 200, Beghelli, Valsamoggia, Bologna, Italy) in 'real-life' conditions by evaluating its ability to reduce microbial loads in several hospital settings during routine daily activities. The efficacy of the UVC lamp in reducing the bacterial component was evaluated by microbial culture through the collection of air samples in different healthcare settings at different times (30 min-24 h) after turning on the device. To assess the anti-viral activity, air samplings were carried out in a room where a SARS-CoV-2-positive subject was present. The UVC device showed good antibacterial properties against a wide range of microbial species after 6 h of activity. It was effective against possible multi-drug resistant microorganisms (e.g., Pseudomonas spp., Acinetobacter spp.) and spore-forming bacteria (e.g., Bacillus spp.). In addition, the UVC lamp was able to inactivate SARS-CoV-2 in just one hour. Thanks to its effectiveness and safety, SanificaAria 200 could be useful to inactivate airborne pathogens and reduce health risks

Humoral immune response to proteins of human cytomegalovirus latency-associated transcripts

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Whole Genome Sequencing of a Chlamydia trachomatis Strain Responsible for a Case of Rectal Lymphogranuloma Venereum in Italy

Lymphogranuloma venereum (LGV) is a systemic sexually transmitted infection caused by Chlamydia trachomatis serovars L1 to L3. The current LGV cases in Europe are mainly characterized by an anorectal syndrome, spreading within men who have sex with men (MSM). Whole-genome sequencing of LGV strains is crucial to the study of bacterial genomic variants and to improve strategies for contact tracing and prevention. In this study, we described the whole genome of a C. trachomatis strain (LGV/17) responsible for a case of rectal LGV. LGV/17 strain was isolated in 2017 in Bologna (North of Italy) from a HIV-positive MSM, presenting a symptomatic proctitis. After the propagation in LLC-MK2 cells, the strain underwent whole-genome sequencing by means of two platforms. Sequence type was determined using the tool MLST 2.0, whereas the genovariant was characterized by an ompA sequence evaluation. A phylogenetic tree was generated by comparing the LGV/17 sequence with a series of L2 genomes, downloaded from the NCBI website. LGV/17 belonged to sequence type ST44 and to the genovariant L2f. Nine ORFs encoding for polymorphic membrane proteins A-I and eight encoding for glycoproteins Pgp1-8 were detected in the chromosome and in the plasmid, respectively. LGV/17 was closely related to other L2f strains, even in the light of a not-negligible variability. The LGV/17 strain showed a genomic structure similar to reference sequences and was phylogenetically related to isolates from disparate parts of the world, indicative of the long-distance dynamics of transmission

Successful Treatment of Bloodstream Infection due to a KPC-Producing Klebsiella Pneumoniae Resistant to Imipenem/Relebactam in a Hematological Patient

Novel carbapenem-β-lactamase inhibitor combination, imipenem/relebactam (IMI-REL), has been recently approved for treatment of infections with limited or no alternative treatment options. In this study, we described the emergence of the IMI-REL-resistance in a KPC-producing Klebsiella pneumoniae (KPC-Kp) strain collected from a hematological patient with no evidence of prior colonization. Interestingly, IMI-REL-resistance was associated with meropenem/vaborbactam (MER-VAB) cross-resistance but was not associated with cross-resistance to ceftazidime/avibactam (CAZ-AVI). Although treatment with CAZ-AVI and gentamicin completely eradicated the infection due KPC-Kp cross-resistance to IMI-REL and MER-VAB, the patient became colonized subsequently by KPC-Kp strains susceptible to IMI-REL and MER-VAB. Whole-genome sequencing performed by hybrid approach using Illumina and Oxford Nanopore platforms demonstrated that all KPC-Kp strains isolated from hematological patient belonged to the ST512 and were clonally related. Analysis of antimicrobial and porins genes demonstrated that cross-resistance to IMI-REL and MER-VAB was associated with increased blaKPC-3 copy number and truncated OmpK35 and OmpK36 with GD134-135 insertion. Phylogenetic analysis demonstrated that KPC-Kp cross-resistance to IMI-REL and MER-VAB was clonally related to a KPC-Kp resistant to IMI-REL as previously described, demonstrating the spread of this multidrug resistant clone in the hematological unit. In conclusion, the results presented in this study reported the emergence of cross-resistance to MER-VAB and IMI-REL in a KPC-Kp strain isolated from a hematological patient and highlight the potential development and diffusion of new multidrug resistance traits

2300. Neonates born to mothers with SARS-CoV-2 infection in pregnancy: a follow-up and serological study

Abstract Background To evaluate the early and late clinical outcomes of neonates born to mothers with SARS-CoV-2 infection in pregnancy, the dynamics of maternal IgG trans placental transfer and its persistence during the first month of life. Methods Prospective study enrolling neonates born to mothers with SARS-CoV-2 infection in pregnancy at IRCCS Azienda Ospedaliero Universitaria di Bologna, Italy, between April 2020 and September 2021. Neonates born to women with infection onset before 2 weeks prior to delivery were enrolled in a 12-month follow-up, including clinical and laboratory evaluations, cranial ultrasound, fundoscopy evaluation. Quantitative IgG to S1/S2 subunits of spike protein were assessed in mother-neonate dyads within 48 hours post-delivery and during follow-up until negative. Transplacental IgG transfer ratio was assessed in relation to the type and trimester of maternal infection. Results One hundred and forty-five neonates were included. the rate of preterm delivery was similar between women with and without SARS-CoV-2 infection (6.2% versus 8.7%, P=0.53). No clinical, laboratory, cerebral and fundoscopy abnormalities were detected at birth or during follow-up, through 11 months (range 8–12). MedianIgG level at birth was not different between neonates born to asymptomatic or symptomatic mothers (18.5 AU/mL, IQR 12–49, versus 31.5 AU/mL, IQR 15–71, P=0.07) nor in relation to the trimester of maternal infection (Table 1), even though mothers with third trimester infections had higher IgG level at birth. Transplacental transfer ratio was higher following second trimester maternal infections and was the lowest following third trimester infections (Table 1). Maternally derived IgG were rapidly weaned, with most infants (115/140, 82%) seronegative by 4 months of age. Conclusion Early and later outcomes of infants born to SARS-CoV-2 infected mothers were favorable. IgG trans placental transfer was higher following second trimester maternal infections, which could be relevant to inform studies on appropriate vaccination strategies aimed at neonatal protection. Maternally derived IgG are rapidly weaned in the first months of life. Disclosures All Authors: No reported disclosures

Virological and histological evaluation of intestinal samples in COVID-19 patients

BACKGROUNDSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the pathogen responsible for pandemic coronavirus disease 2019 (COVID-19). It is a highly contagious virus which primarily affects the respiratory tract, nevertheless, the lungs are not the only target organs of the virus. The intestinal tract could represent an additional tropism site for SARS-CoV-2. Several observations have collectively suggested that enteric infections can occur in COVID-19 patients. However, the detection of viral RNA in gastrointestinal (GI) tissue samples has not been adequately investigated and results are conflicting.AIMTo detect the presence of SARS-CoV-2 RNA in intestinal mucosa samples and to evaluate histological features.METHODSThe COVID-19 patients hospitalized at an Italian tertiary hospital from April 2020 to March 2021 were evaluated for enrollment in an observational, monocentric trial. The study population was composed of two groups of adult patients. In the first group (biopsy group, 30 patients), patients were eligible for inclusion if they had mild to moderate disease and if they agreed to have a rectal biopsy; in the second group (surgical specimen group, 6 patients), patients were eligible for inclusion if they underwent intestinal resection during index hospitalization. Fifty-nine intestinal mucosal samples were analyzed.RESULTSViral RNA was not detectable in any of the rectal biopsies performed (0/53). Histological examination showed no enterocyte damage, but slight edema of the lamina propria with mild inflammatory lymphoplasmacytic infiltration. There was no difference in inflammatory infiltrates in patients with and without GI symptoms. SARS-CoV-2 RNA was detected in fecal samples in 6 cases out of 14 cases examined (42.9%). In the surgical specimen group, all patients underwent emergency intestinal resection. Viral RNA was detected in 2 surgical specimens of the 6 examined, both of which were from patients with active neoplastic disease. Histological examination also pointed out abundant macrophages, granulocytes and plasma cells infiltrating the muscular layer and adipose tissue, and focal vasculitis.CONCLUSIONMild-moderate COVID-19 may not be associated with rectal infection by the virus. More comprehensive autopsies or surgical specimens are needed to provide histological evidence of intestinal infection

Altered intracellular ATP production by activated CD4+ T-cells in very preterm infants

Background. The neonatal immune system is not fully developed at birth; newborns have adequate lymphocytes counts but these cells lack function. Objective. To assess the activity of T-cells and the influence of the main perinatal factors in very preterm infants (birth weight < 1500 g). Design. Blood samples from 59 preterm infants (21/59 were dizygotic twins) were collected at birth and at 30 days of life to measure CD4+ T-cell activity using the ImmuKnow\u2122 assay. Fifteen healthy adults were included as a control group. Results. CD4+ T-cell activity was lower in VLBW infants compared with adults (p<0.001). Twins showed lower immune activity compared to singletons (p=0.005). Infants born vaginally showed higher CD4+ T-cell activity compared to those born by C-section (p=0.031); infants born after prolonged Premature Rupture of Membranes (pPROM) showed higher CD4+ T-cell activity at birth (p=0.002) compared to infants born without pPROM. Low CD4+ T-cell activity at birth is associated with necrotizing enterocolitis (NEC) in the first week of life (p=0.049). Conclusions. Preterm infants show a lack in CD4+ T-cell activity at birth. Perinatal factors such as intrauterine inflammation, mode of delivery, and zygosity can influence the adaptive immune activation capacity at birth and can contribute to exposing these infants to serious complications such as NEC

Non-pathogenic Neisseria species of the oropharynx as a reservoir of antimicrobial resistance: a cross-sectional study

Commensal Neisseria species of the oropharynx represent a significant reservoir of antimicrobial resistance determinants that can be transferred to Neisseria gonorrhoeae. This aspect is particularly crucial in ‘men having sex with men’ (MSM), a key population in which pharyngeal co-colonization by N. gonorrhoeae and non-pathogenic Neisseria species is frequent and associated with the emergence of antimicrobial resistance. Here, we explored the antimicrobial susceptibility of a large panel of non-pathogenic Neisseria species isolated from the oropharynx of two populations: a group of MSM attending a ‘sexually transmitted infection’ clinic in Bologna (Italy) (n=108) and a group of males representing a ‘general population’ (n=119). We collected 246 strains, mainly belonging to N. subflava (60%) and N. flavescens (28%) species. Their antimicrobial susceptibility was evaluated assessing the minimum inhibitory concentrations (MICs) for azithromycin, ciprofloxacin, cefotaxime, and ceftriaxone using E-test strips. Overall, commensal Neisseria spp. showed high rates of resistance to azithromycin (90%; median MICs: 4.0 mg/L), and ciprofloxacin (58%; median MICs: 0.12 mg/L), whereas resistance to cephalosporins was far less common (<15%). Neisseria strains from MSM were found to have significantly higher MICs for azithromycin (p=0.0001) and ciprofloxacin (p<0.0001) compared to those from the general population. However, there was no significant difference in cephalosporin MICs between the two groups. The surveillance of the antimicrobial resistance of non-pathogenic Neisseria spp. could be instrumental in predicting the risk of the spread of multi-drug resistant gonorrhea. This information could be an early predictor of an excessive use of antimicrobials, paving the way to innovative screening and prevention policies