Genomic characterisation of Escherichia coli isolates co-producing NDM-5 and OXA-1 from hospitalised patients with invasive infections.

OBJECTIVES: Carbapenems are one of the last-report therapeutic choices to treat infections due to multidrug-resistant (MDR) micro-organisms. For this reason, the spread of carbapenemase-producing Enterobacteriaceae represents a serious health-public problem. Here we describe isolates co-producing blaNDM-5 and blaOXA-1. METHODS: Three Escherichia coli isolates obtained from patients with invasive infections were analysed by phenotypic antibiotic susceptibility testing and whole-genome sequencing (WGS). RESULTS: All of the isolates were resistant to carbapenems, most ß-lactam antibiotics, piperacillin/tazobactam, amoxicillin/clavulanic acid and ciprofloxacin, remaining susceptible to amikacin, fosfomycin, colistin and tigecycline. The isolates belonged to sequence types ST44, ST405 and ST167 and co-harboured the blaNDM-5 and blaOXA-1 genes. Two of the isolates also harboured extended-spectrum ß-lactamase (ESBL) genes (blaCTX-M-15 and blaTEM-1b). The blaNDM-5 gene was probably carried chromosomally even if different plasmids were identified. Various virulence genes were also identified. CONCLUSION: Our results highlight that continuous surveillance is essential to monitor the spread of clinically important MDR pathogens.

In vitro inhibitory effect of two commercial probiotics on chromogenic actinomycetes.

PURPOSE: Black extrinsic discoloration is a common clinical and aesthetic problem. This study aims to evaluate the potential in vitro antagonistic activity of two commercial probiotics, Streptococcus salivarius M18 and Lactobacillus reuteri ProDentis, against microorganisms associated with black stains. METHODS: Streptococcus salivarius M18 and Lactobacillus reuteri were tested against Aggregatibacter actinomycetemcomitans and Actinomyces naeslundiiusing their cell-free fermentative broth in a planktonic growth inhibition test. RESULTS: Both probiotic cell-free supernatants showed the ability to reduce the pathogenic bacteria growth in a dose-dependent way. Streptococcus salivarius M18 showed a stronger antimicrobial activity than Lactobacillus reuteri ProDentis against the two indicator strains used. A. naeslundi was less susceptible to the probiotic activity of both S. salivarius and L. reuteri compared to A. actinomycetemcomitans. CONCLUSIONS: The obtained results demonstrate a potent antagonistic ability of probiotics to reduce the growth of microorganisms associated with black tooth stains. Therefore, these strains could be evaluated for a therapeutic use against dental pigmentations.

Correlation between tcdB gene PCR cycle threshold and severe Clostridium difficile disease.

A retrospective study, including all samples tested for Clostridium difficile from 2015 to 2018, was conducted. 222 and 199 patients were respectively classified as having a mild/moderate or severe disease. A CT ≤ 26 was significantly associated with severe disease. Furthermore, low CT values were significantly associated to older patients and leukocytosis.

Circulating endothelial cell count: a reliable marker of endothelial damage in patients undergoing hematopoietic stem cell transplantation.

The physio-pathologic interrelationships between endothelium and GvHD have been better elucidated and have led to definition of the entity 'endothelial GvHD' as an essential early phase prior to the clinical presentation of acute GvHD. Using the CellSearch system, we analyzed circulating endothelial cells (CEC) in 90 allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients at the following time-points: T1 (pre-conditioning), T2 (pre-transplant), T3 (engraftment), T4 (onset of GvHD) and T5 (1 week after steroid treatment). Although CEC changes in allo-HSCT represent a dynamic phenomenon influenced by many variables (that is, conditioning, immunosuppressive treatments, engraftment syndrome and infections), we showed that CEC peaks were constantly seen at onset of acute GvHD and invariably returned to pre-transplant values after treatment response. Since we showed that CEC changes during allo-HSCT has rapid kinetics that may be easily missed if blood samples are drawn at pre-fixed time-points, we rather suggest an 'on demand' evaluation of CEC counts right at onset of GvHD clinical symptoms to possibly help differentiate GvHD from other non-endothelial complications. We confirm that CEC changes are a suitable biomarker to monitor endothelial damage in patients undergoing allo-transplantation and hold the potential to become a useful tool to support GvHD diagnosis (ClinicalTrials.gov NCT02064972).

Invasive Candidiasis in Brescia, Italy: Analysis of Species Distribution and Antifungal Susceptibilities During Seven Years.

The aims of this study were to evaluate the epidemiology of nosocomial candidemia in a large teaching hospital in Brescia, Italy, and the in vitro antifungal susceptibility of isolates. We analyzed 196 isolates causing fungemia in patients admitted in our hospital, between January 2009 and December 2015. Strains were identified by VITEK 2 and MALDI-TOF MS. MICs were determined by Sensititre Yeast OneTM. The resistance was defined by using the revised CLSI breakpoints/epidemiological cutoff values to assign susceptibility or wild type to systemic antifungal agents. Most infections were caused by Candida albicans (60%), Candida parapsilosis (15%), Candida glabrata (12%) and Candida tropicalis (6%). The susceptibility rate for fluconazole was 96.5%. Non-Candida species isolates exhibited full susceptibilities to echinocandins according to CLSI breakpoints. Amphotericin B demonstrated excellent activity against all Candida species. Local epidemiological and antifungal susceptibility studies are necessary in order to improve empirical treatment guidelines.

Emergence of the first levofloxacin-resistant strains of Streptococcus agalactiae isolated in Italy.

Of 901 group B streptococcus strains analyzed, 13 (1.4%) were resistant to levofloxacin (MICs of >32 µg/ml for seven isolates, 2 µg/ml for four isolates, and 1.5 µg/ml for four isolates). Mutations in the quinolone resistance-determining regions (QRDRs) of gyrase and topoisomerase IV were identified. A double mutation involving the Ser-81 change to Leu for gyrA and the Ser-79 change to Phe or to Tyr for parC was linked to a high level of fluoroquinolone resistance. In addition, two other mutational positions in parC were observed, resulting in an Asp-83-to-Tyr substitution and an Asp-83-to-Asn substitution. Different mutations were also observed in gyrB, with unknown significance. Most levofloxacin-resistant GBS strains were of serotype Ib and belonged to sequence type 19 (ST19) and clonal complex 19 (CC-19). Most of them exhibited the epsilon gene.

HLA antigenic and haplotype frequencies estimated in hematopoietic progenitor cell donors from Argentina.

BACKGROUND: Hematopoietic progenitor cell transplantation is considered a standard-of-care treatment for defined hematological and non-hematological conditions affecting bone marrow-derived cells. METHODS: Patients and potential donors are HLA typed for their HLA-A, -B, -C, -DRB1, and -DQB1 alleles. The best allogeneic donor is one for which each allele matches the patient at HLA-A, -B, -C, and -DRB1 (8/8). For patients with no related donor, the transplant physician will start a search for unrelated donors. The search is performed through a local registry and often includes the search for donors worldwide. The Argentinean HPC Donors Registry was established in 2003. Our National HPC Donor Registry has already typed more than 31,000 donors for HLA-A, -B, and -DR. RESULTS: We present the analysis of HLA frequencies and haplotypes estimates for the subset of our donor database that is additionally typed for HLA-C. We analyzed HLA data from 2657 donors. Antigen and haplotype frequencies were estimated through the use of expectation maximization. CONCLUSIONS: Our analysis showed for the first time the antigenic HLA frequency distribution from HPC donors in Argentina. Knowing haplotype frequencies in our population will help us to select potential donors for high-resolution typing for the patients.

Bloodstream cells phenotypically identical to human mesenchymal bone marrow stem cells circulate in large amounts under the influence of acute large skin damage: new evidence for their use in regenerative medicine.

OBJECTIVES: Recent work has shown that human bone marrow contains mesenchymal stem cells (MSCs). However, little is known about their presence in peripheral blood. Since these cells are potentially responsible for tissue repair after injury, their number should be increased during these situations. To demonstrate their number during these situations, we measured MSCs in the peripheral blood of healthy donors and burn patients. MATERIALS AND METHODS: Blood samples were obtained from 15 acute burn patients and 15 healthy donors. We performed flow cytometric analysis, using a large monoclonal antibody panel: CD44, CD45, CD14, DR, CD34, CD19, CD13, CD29, CD105, CD1a, CD90, CD38, CD25. MSC phenotype was considered positive for CD44, CD13, CD29, CD90, and CD105, and negative for the other monoclonals. The testing was performed on day 3 after injury. We correlated the results with the age, sex, and size and type of burns. RESULTS: Cells expressing the MSC phenotype were detected in the peripheral blood of both groups. Noteworthy, compared with samples from healthy donors (0.0078 +/- 0.0044), blood obtained from burn patients showed a higher MSC percentage (0.1643 +/- 0.115; P < .001). The percentage of MSCs correlated with the size and severity of the burn. Increased values were also observed among younger patients. CONCLUSIONS: MSCs have an important role in regenerative processes of human tissues. We found cells phenotypically identical to MSCs circulating in physiological number in normal subjects, but in significantly higher amounts during acute large burns. Therefore, they may represent a previously unrecognized circulatory component to the process of skin regeneration.

Human mesenchymal stem cells are tolerized by mice and improve skin and spinal cord injuries.

INTRODUCTION: We sought to use human mesenchymal stem cells (HMSC) for skin and spinal cord repair in mice. MATERIALS AND METHODS: Human bone marrow obtained from a young healthy donor was used to separate and culture human mesenchymal stem cells (HMSC). Ten mice were included in each of four groups. A full-thickness skin defect was surgically performed on all mice in groups 1 and 2. A transverse complete medullar section was performed in groups 3 and 4. Groups 1 and 3 received HMSC IV infusion and local HMSC polymer implant. Groups 2 and 4 received only the IV HMSC infusion. Five control animals from each group went through the same lesions but they didn't receive treatment. RESULTS: After local administration of HMSC into the fibrin polymer combined with the IV infusion of HMSC, there was no immune rejection; all skin defects healed without scar or retraction at a median time of 14 days. Sixty percent of the animals treated with IV infusion and polymer with HMSC simultaneously had improved neurological activities, while all control mice with spinal cord injury experiments died or perpetuated their paralysis with worsening muscular atrophy and increasing propensity to skin damage. CONCLUSIONS: HMSC are not immunologically reactive and can trespass species defense barriers. Animals treated with these cells repaired injuries better than controls. In this way we propose that universal HMSC from donors can be cultured, expanded, and cryopreserved to be used in human organ or tissue regeneration.

Antígenos HLA en alcoholismo / HLA antigens in alcoholism

Se estudiaron antígenos de histocompatibilidad, sistema HLA-loci ABC y DR en una muestra de 30 pacientes alcohólicos. El criterio de inclusión de los pacientes fue muy riguroso, y referido a la presencia de signos y síntomas del síndrome de abstinencia. Los valores encontrados se compararon con los determinados en la población general. Se encontró un aumento de los antígenos B-40 y DR4, y una disminución del DR3 en la población alcohólica. Se determinó riesgo relativo, fracción etiológica y fracción preventiva para desarrollar el síndrome de abstinencia en sujetos alcohólicos que presentaban los citados antígenos