Biological Variation in Protein C, Protein S and Antithrombin Concentrations in Plasma of Healthy Subjects

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Multicenter prospective study on the prevalence of colistin resistance in escherichia coli: Relevance of mcr-1-positive clinical isolates in Lombardy, Northern Italy

Background: The emergence of the plasmid-mediated colistin resistance mechanism in Escherichia coli has raised concern among public health experts as colistin is a last-line antimicrobial resort. The primary aim of the study was to investigate the prevalence of this resistance trait in E. coli isolates circulating in the Lombardy region, Northern Italy. The presence of mcr-type genes and their genetic relationship were also studied. Materials and methods: A prospective study was performed during a 4-month period (May to August, 2016) in six acute care Hospitals. Consecutive nonduplicate clinical isolates of E. coli from any type of clinical specimen, with the exception of rectal swabs, were included in the study. Isolates that exhibited MIC values for colistin >2 mg/L were further investigated. Bacterial identification was obtained by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Amplification of mcr-type genes (-1 to -5 variants) and microarray analysis were accomplished. Repetitive sequence-based PCR (Rep-PCR) and multilocus sequence typing (MLST) analysis were used for genotyping. Results: Overall, 3,902 consecutive E. coli isolates (2,342 from outpatients, 1,560 from inpatients) were evaluated during the study period. Of them, 18/3,902 (0.5%), collected from 4/6 centers, showed resistance to colistin. These isolates were mostly obtained from urine of both outpatients (n=12) and inpatients (n=6). Colistin MIC values ranged from 4 to 8 mg/L. The mcr-1 gene was detected in 10/18 isolates (7 from outpatients, 3 from inpatients). Rep-PCR and MLST analysis revealed the presence of nine different clusters. Further mcr-type genes were not detected. Conclusion: Resistance to colistin in E. coli clinical isolates appears low in our geographic area. With regard to mcr-1-positive isolates, they accounted for approximately 50% of colistin-resistant E. coli isolates, thus representing a relevant resistance mechanism in this context. Although overall limited, the presence of mcr-1 determinant in our region should not be ignored and great concern should be given to the continuous surveillance

the importance of an early alert from the microbiology laboratory and multidisciplinary collaboration during a suspected salmonellosis outbreak

Background and aims. Salmonellosis is one of the most common and widely distributed food-borne diseases. The increasing complexity and globalization of the food industry are causing an increase of some of these large-scale food-borne illnesses, thus there is a need for improvements in public health signal detection and communication streams between laboratories and regulatory agencies. The aim of this study is to show how the early reporting of salmonellosis cases directly from the Laboratory of Microbiology to the Local Health Service Infectious Diseases Office along with the prompt response of the ASL, and the rapid involvement of the Local Veterinary Prevention Department resulted in an improved individuation and investigation of a suspected food-borne outbreak with anomalous manifestation. Materials and methods. From August to November 2014 the early warning from the Laboratory of Microbiology regarding Salmonella spp. isolates with the identical serogroup and antibiotic resistance phenotype, allowed for prompt identification of a food-borne infection. Results and conclusions. The genotyping analysis suggested that over the period considered there was more than a single monophasic Salmonella typhimurium isolate: one responsible for the sporadic cases that occurred in September and October, and another in November

Rhamnolipid 89 Biosurfactant Is Effective against <i>Streptococcus oralis</i> Biofilm and Preserves Osteoblast Behavior: Perspectives in Dental Implantology

Biofilm-related peri-implant diseases represent the major complication for osteointegrated dental implants, requiring complex treatments or implant removal. Microbial biosurfactants emerged as new antibiofilm coating agents for implantable devices thanks to their high biocompatibility. This study aimed to assess the efficacy of the rhamnolipid 89 biosurfactant (R89BS) in limiting Streptococcus oralis biofilm formation and dislodging sessile cells from medical grade titanium, but preserving adhesion and proliferation of human osteoblasts. The inhibitory activity of a R89BS coating on S. oralis biofilm formation was assayed by quantifying biofilm biomass and microbial cells on titanium discs incubated up to 72 h. R89BS dispersal activity was addressed by measuring residual biomass of pre-formed biofilms after rhamnolipid treatment up to 24 h. Adhesion and proliferation of human primary osteoblasts on R89BS-coated titanium were evaluated by cell count and adenosine-triphosphate quantification, while cell differentiation was studied by measuring alkaline phosphatase activity and observing mineral deposition. Results showed that R89BS coating inhibited S. oralis biofilm formation by 80% at 72 h and dislodged 63–86% of pre-formed biofilms in 24 h according to concentration. No change in the adhesion of human osteoblasts was observed, whereas proliferation was reduced accompanied by an increase in cell differentiation. R89BS effectively counteracts S. oralis biofilm formation on titanium and preserves overall osteoblasts behavior representing a promising preventive strategy against biofilm-related peri-implant diseases

Laboratory predictors of death from coronavirus disease 2019 (COVID-19) in the area of Valcamonica, Italy

Background Comprehensive information has been published on laboratory tests which may predict worse outcome in Asian populations with coronavirus disease 2019 (COVID-19). The aim of this study is to describe laboratory findings in a group of Italian COVID-19 patients in the area of Valcamonica, and correlate abnormalities with disease severity. Methods The final study population consisted of 144 patients diagnosed with COVID-19 (70 who died during hospital stay and 74 who survived and could be discharged) between March 1 and 30, 2020, in Valcamonica Hospital. Demographical, clinical and laboratory data were collected upon hospital admission and were then correlated with outcome (i.e. in-hospital death vs. discharge). Results Compared to patients who could be finally discharged, those who died during hospital stay displayed significantly higher values of serum glucose, aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), urea, creatinine, high-sensitivity cardiac troponin I (hscTnI), prothrombin time/international normalized ratio (PT/INR), activated partial thromboplastin time (APTT), D-dimer, C reactive protein (CRP), ferritin and leukocytes (especially neutrophils), whilst values of albumin, hemoglobin and lymphocytes were significantly decreased. In multiple regression analysis, LDH, CRP, neutrophils, lymphocytes, albumin, APTT and age remained significant predictors of in-hospital death. A regression model incorporating these variables explained 80% of overall variance of in-hospital death. Conclusions The most important laboratory abnormalities described here in a subset of European COVID-19 patients residing in Valcamonica are highly predictive of in-hospital death and may be useful for guiding risk assessment and clinical decision-making

Prevalence of colistin resistance in Escherichia coli: mcr-1-positive clinical isolates in Lombardy, Northern Italy

Background: The recent emergence of the plasmid-mediated colistin resistance mechanism in Escherichia coli, Klebsiella pneumoniae and Salmonella spp. has raised concern among public health experts as colistin is a last-line antibiotic for the treatment of infections by carbapenem resistant Enterobacteriaceae. The aim of the study was to investigate i) the prevalence of this resistance trait in E. coli, and ii) the presence of mcr-1 and mcr-2 genes among colistin-resistant isolates in the Lombardy region, Northern Italy. Material/methods: The study was performed during a 4-month period (May-August 2016) in six acute care Hospitals. Non duplicated E. coli isolates from clinical samples of both outpatients and inpatients were included in the study (surveillance rectal swabs were excluded). Bacterial species identification was obtained by MALDI-TOF mass spectrometry. Colistin resistance (MIC > 2 mg/L) was first evaluated by routine automated systems and then confirmed by the reference broth microdilution method (EUCAST, 2016). Amplification of mcr-type genes, and microarray analysis were accomplished. Phylogroup identification, rep-PCR (DiversiLab) and PFGE (XbaI) were used for genotyping. The mcr-1-positive plasmids were characterized by PBRT kit and PCR (IncX). Results: Overall, 3902 E. coli isolates were evaluated (1560 from inpatients, 2342 from outpatients). Of them, 18/3902 (0.5%), collected from 4/6 centers, showed resistance to colistin. These isolates were obtained from both inpatients (n=6) and outpatients (n=12). In particular, hospitalized patients were from medical (3/6), rehabilitation (2/6), and surgical (1/6) wards. The great majority of colistinresistant isolates were from urine (16/18) but two of them were from blood cultures. Colistin MIC values ranged from 4 to 16 mg/L (as assessed by the reference method). The mcr-1 gene was detected in 10/18 isolates, all of which from urine cultures (7 from outpatients, 3 from inpatients). In these cases, colistin MIC values ranged from 4 to 8 mg/L. Of note, 6/10 mcr-1-positive E. coli isolates were also resistant to ciprofloxacin and trimethoprim-sulfamethoxazole, and 2 of them were also positive for the SHV-12 ESBL enzyme. All mcr-1-positive E. coli strains resulted unrelated by PFGE analysis, while rep-PCR showed eight different clusters. The identified phylogroups were A and D (in four cases each), B1 and B2 (in one case each). The incompatibility groups were IncX4 in 7/10 strains, IncHI2 in the remaining 3/10. The mcr-2 gene was never detected. Conclusions: According to most recent surveillances, our study demonstrates a low prevalence of colistin resistance among E. coli isolates also in the Lombardy region. In addition, our data show that the mcr-1 gene plays a prominent role in this context. Of particular concern, it appears the frequent detection of mcr-1 gene among isolates from urine cultures of outpatients, thus suggesting the opportunity of routine testing the antimicrobial susceptibility for colistin in these cases