Phylogenetic Analysis of Multi-Drug Resistant Klebsiella pneumoniae Strains From Duodenoscope Biofilm: Microbiological Surveillance and Reprocessing Improvements for Infection Prevention

Duodenoscopes have been described as potential vehicles of patient-to-patient transmission of multi-drug resistant organisms. Carbapenem-resistant Enterobacteriaceae duodenoscope related infections have been described by the Center for Disease Control and the US Food and Drug Administration consequently to outbreaks occurring in the United States. These evidences suggested that improved microbiological surveillance and endoscope design optimization could represent valid tools to improve infection control. At this aim, in this study an example of duodenoscope microbiological surveillance and reprocessing improvement analyzing strains component of bacterial biofilm by phylogenetic analysis has been proposed. From September 2016 to December 2017, duodenoscope instruments were subjected to microbial surveillance by post-reprocessing cultures of liquid collected by internal channels of instruments after injection and aspiration cycles and membrane filtration. During surveillance seventeen Klebsiella pneumoniae, of which 10/17 (58.8%) MDR and KPC strains were collected from duodenoscope instruments plus one MDR Klebsiella pneumoniae strain from the rectal swab performed before ERCP procedure in an inpatient. The surveillance allowed evidencing potential failure of reprocessing procedure and performing consequent reprocessing improvements including the contaminated instruments quarantine until their negativity. Phylogenetic analysis of whole genome sequence of duodenoscope strains plus inpatients MDR strains, showed intermixing between duodenoscopes and inpatients, as evidenced by minimum spanning tree and time-scale Maximum Clade Credibility tree. In minimum spanning tree, three groups have been evidenced. Group I including Klebsiella pneumoniae strains, isolated from inpatients before microbiological surveillance adoption; group II including intermixed Klebsiella pneumoniae strains isolated from inpatients and Klebsiella pneumoniae strains isolated from duedonoscopes and group III including Klebsiella pneumoniae strains exclusively from duedonoscope instruments. In the Maximum Credibility Tree, a statistically supported cluster including two Klebsiella pneumoniae strains from duedonoscope instruments and one strains isolated from an inpatient was showed. From the first microbiologic surveillance performed on September 2016 and after the reprocessing improvement adoption, none MDR or susceptible Klebsiella pneumoniae strain was isolated in the following surveillance periods. In conclusion, these results should encourage hospital board to perform microbiological surveillance of duodenoscopes as well as of patients, by rectal swabs culture, and rapid molecular testing for antimicrobial resistance before any endoscopic invasive procedure.

A case of methicillin-resistant Staphylococcus aureus wound infection: phylogenetic analysis to establish if nosocomial or community acquired

Methicillin‐resistant Staphylococcus aureus (MRSA) infection is rapidly increasing in both hospital and community settings. A 71‐year‐old man admitted at the Department of Orthopaedics and Trauma Surgery, University Campus Bio‐Medico of Rome, with MRSA wound infection consequent to orthopedic surgery was studied and the MRSA transmission evaluated by phylogenetic analysis.

The role of procalcitonin in the diagnosis of bacterial infection after major abdominal surgery: Advantage from daily measurement

Postsurgical infections represent an important cause of morbidity after abdominal surgery. The microbiological diagnosis is not achieved in at least 30% of culture with consequent worsening of patient outcome. In this study, procalcitonin measurement, during the first 3 days after abdominal surgery, has been evaluated for the early diagnosis of postsurgical infection.Ninety consecutive patients subjected to major abdominal surgery at the University Campus Bio-Medico of Rome, have been included. PCT concentrations were measured by time-resolved amplified cryptate emission (TRACE) assay at admission and at the first, second, and third day after surgery. PCT levels were compared using the Mann-Whitney test and by ANOVA test for variance analysis. Receiver operating characteristic (ROC) analysis was performed to define the diagnostic ability of PCT in case of postsurgical infections.PCT values resulted significantly different between patients developing or not developing postsurgical infections. PCT >1.0 ng/mL at first or second day after surgery and >0.5 ng/mL at third day resulted diagnostic for infectious complication, whereas a value <0.5 ng/mL at the fifth day after surgery was useful for early and safety discharge of patients.In conclusion, PCT daily measurement could represent a useful diagnostic tool improving health care in the postsurgical period following major abdominal surgery and should be recommended.

Susceptibility to measles in migrant population: implication for policy makers

BACKGROUND

Despite a large measles outbreak is taking place in WHO European region, currently no data are available on measles immunization coverage in the asylum seeker and migrants hosted in this area.

METHODS

Two hundred and fifty-six migrants upon their arrival in Italy on March, April and May 2016 were screened for measles virus IgG antibodies by chemiluminescence immunoassay (Liaison XL analyzer, Diasorin, Italy). The virus susceptibility in this cohort, the differences between the official country reported and the observed measles immunization coverage and the impact of current measles outbreak on the asylum seekers hosted in the largest Asylum Seeker centres of Italy, were evaluated.

RESULTS

The prevalence of subjects with positive result for measles IgG antibodies ranged between 79.9% and 100%. In Senegal, Mali, Nigeria, Pakistan and Bangladesh, the measles IgG seroprevalence observed was greater than the vaccinal coverage reported by WHO after I dose of vaccine. Based on data regarding the II dose coverage, the ASs population presented a seroprevalence greater to that expected.

CONCLUSION

On the basis of the results obtained, extraordinary screening and vaccination campaigns in the migrant population, especially in the course of large outbreaks, could represent a resource to reach an adequate measles immunization coverage and to control this infectious disease.

Visceral leishmaniasis triggering an adult-onset Still's disease: a unique case

Adult‐onset Still's disease (AOSD) due to visceral leishmaniasis (VL) has not been previously reported. This case report analyzes a single episode of AOSD probably due to a visceral leishmaniasis successfully treated with pentamidine isethionate and prednisone.

Phylogenetic Analysis of Human Immunodeficiency Virus Type 2 Group B

CONTEXT

Human immunodeficiency virus type 2 (HIV-2) infections are mainly restricted to West Africa; however, in the recent years, the prevalence of HIV-2 is a growing concern in some European countries and the Southwestern region of India. Despite the presence of different HIV-2 groups, only A and B Groups have established human-to-human transmission chains.

AIMS

This work aimed to evaluate the phylogeographic inference of HIV-2 Group B worldwide to estimate their data of origin and the population dynamics.

MATERIALS AND METHODS

The evolutionary rates, the demographic history for HIV-2 Group B dataset, and the phylogeographic analysis were estimated using a Bayesian approach. The viral gene flow analysis was used to count viral gene out/in flow among different locations.

RESULTS

The root of the Bayesian maximum clade credibility tree of HIV-2 Group B dated back to 1957. The demographic history of HIV-2 Group B showed that the epidemic remained constant up to 1970 when started an exponential growth. From 1985 to early 2000s, the epidemic reached a plateau, and then it was characterized by two bottlenecks and a new plateau at the end of 2000s. Phylogeographic reconstruction showed that the most probable location for the root of the tree was Ghana. Regarding the viral gene flow of HIV-2 Group B, the only observed viral gene flow was from Africa to France, Belgium, and Luxembourg.

CONCLUSIONS

The study gives insights into the origin, history, and phylogeography of HIV-2 Group B epidemic. The growing number of infections of HIV-2 worldwide indicates the need for strengthening surveillance.

Unusual microorganisms and antimicrobial resistances in a group of Syrian migrants: Sentinel surveillance data from an asylum seekers centre in Italy

BACKGROUND

Three years of civil war in Syria have caused death and increase of communicable diseases. The suffering population has been forced to migrate creating a fertile condition for epidemic spread of infection within the refugee camps.

METHODS

Forty-eight Syrian migrants, upon their arrival in Italy, were accommodated at the asylum seekers centre of Castelnuovo di Porto. They received a physical examination and were subjected to microbiological surveillance by blood, rectal, pharyngeal and nasal swabs collection and delivering to the Clinical Pathology and Microbiology Laboratory of the University Campus Bio-Medico of Rome.

RESULTS

All refugees resulted negative for HBV, HCV and HIV infections. In swabs a large number of unusual gram-negative bacteria species were isolated, such as Pseudomonas putida, Pseudomonas monteilii, Pseudomonas fulva, Pseudomonas moselii, Aeromonas veronii, Aeromonas caviae, Aeromonas hydrophila, Acinteobacter guilloviae, Acinteobacter lowffii; Acinetobacter johnsonii; Acinteobacter tjernbergae; Pantoea agglomerans; Pantoea calida. Among isolates, strains resistant to carbapenems, ESBL producers and methicillin resistant were found.

CONCLUSIONS

The microbiological surveillance performed represents a useful action to understand refugees health status and to trace unusual microorganisms movement even carriers of antimicrobial resistance during migrants traveling.

Cronobacter sakazakii DNA Detection in Cerebrospinal Fluid of a Patient with Amyotrophic Lateral Sclerosis Mimic Syndrome

A 45-year-old male noticed progressive weakness of the right lower limb with gait disturbance. Over the following months, motor deficits worsened, spreading to the right upper limb. Electromyography showed active denervation in the upper and lower limb muscles. A diagnosis of amyotrophic lateral sclerosis (ALS) was made. About 2 years after symptom onset, gradual improvement occurred. Cerebrospinal fluid analysis performed about 3 years after the beginning of symptoms identified Cronobacter sakazakii. Since no other possible causes were identified, we suggest that an almost completely reversible ALS-like syndrome had been triggered by Cronobacter infection in our immunocompetent patient.

Phylogeny of Murray Valley encephalitis virus in Australia and Papua New Guinea

OBJECTIVE

To study the genetic diversity of Murray Valley encephalitis virus (MVEV) in Australia and Papua New Guinea.

METHODS

MVEV envelope gene sequences were aligned using Clustal X and manual editing was performed with Bioedit. ModelTest v. 3.7 was used to select the simplest evolutionary model that adequately fitted the sequence data. Maximum likelihood analysis was performed using PhyML. The phylogenetic signal of the dataset was investigated by the likelihood mapping analysis. The Bayesian phylogenetic tree was built using BEAST.

RESULTS

The phylogenetic trees showed two main clades. The clade Ⅰ including eight strains isolated from West Australia. The clade Ⅱ was characterized by at least four epidemic entries, three of which localized in Northern West Australia and one in Papua New Guinea. The estimated mean evolutionary rate value of the MVEV envelope gene was 0.407 × 10(-3) substitution/site/year (95% HPD: 0.623 × 10(-4)-0.780 × 10(-3)). Population dynamics defines a relative constant population until the year 2000, when a reduction occurred, probably due to a bottleneck.

CONCLUSIONS

This study has been useful in supporting the probable connection between climate changes and viral evolution also by the vector point of view; multidisciplinary monitoring studies are important to prevent new viral epidemics inside and outside new endemic areas.

MALDI-TOF mass spectrometry and blakpc gene phylogenetic analysis of an outbreak of carbapenem-resistant K. pneumoniae strains

Carbapenem-resistant Klebsiella pneumoniae isolates are an important cause of nosocomial infections. This study evaluated a rapid cost-saving method based on MALDI-TOF technology, was and compared it with phenotypic, genotypic and epidemiological data for characterization of KPC-Kp strains consecutively isolated during a supposed outbreak. Twenty-five consecutive KPC Klebsiella pneumoniae isolates were identified and clustered by the MALDI Biotyper (Bruker, Daltonics). To display and rank the variance within a data set, principal component analysis (PCA) was performed. ClinProTools models were generated to investigate the highest sum of recognition capability and cross-validation. A Class dendrogram of isolates was constructed using ClinproTool. MLST was performed sequencing gapA, infB, mdh, pgi, rpoB, phoE and tonB genes. blakpc and cps genes were typed. Phylogenetic analysis and genetic distance of the KPC gene were performed using the MEGA6 software. PCA analysis defined two clusters, I and II, which were identified in a dendrogram by both temporal split and different antimicrobial susceptibility profiles. These clusters were composed mostly of strains of the same sequence type (ST512), the most prevalent ST in Italy, and the same cps (type 2). In cluster II, blakpc genotype resulted more variable than in cluster I. Phylogenetic analysis confirmed the genetic diversity in both clusters supported by the epidemiological data. Our study confirms that MALDI-TOF can be a rapid and cost-saving method for epidemiological clustering of KPC K. pneumoniae isolates and its association with blakpc genotyping represents a reliable method to recognize possible clonal strains in nosocomial settings.

Turnaround time of positive blood cultures after the introduction of matrix-assisted laser desorption-ionization time-of-flight mass spectrometry

A comparative evaluation of the turnaround time (TAT) of positive blood culture before and after matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) introduction in the laboratory routine was performed. A total of 643 positive blood cultures, of which 310 before and 333 after MALDI-TOF technique introduction, were collected. In the post MALDI-TOF period, blood culture median TAT decreased from 73.53 hours to 71.73 for Gram-positive, from 64.09 hours to 63.59 for Gram-negative and from 115.7 hours to 47.62 for anaerobes. MALDI-TOF significantly decreased the TAT of anaerobes, for which antimicrobial susceptibility test is not routinely performed. Furthermore, the major advantage of MALDI-TOF introduction was the decrease of the time for pathogen identification (TID) independently from the species with an improvement of 93% for Gram-positive, 86% for Gram-negative and 95% for anaerobes. In addition, high species-level identification rates and cost savings than conventional methods were achieved after MALDI-TOF introduction.

Diagnostic and prognostic role of procalcitonin (PCT) and MR-pro-Adrenomedullin (MR-proADM) in bacterial infections

Rapid diagnosis of bacterial infections is crucial for adequate antibiotic treatment. Serum molecules such as Procalcitonin (PCT) have been used as biomarkers of infection. Recently, the mid-regional pro-Adrenomedullin (MR-proADM) has been evaluated in combination with PCT for sepsis diagnosis. The diagnostic role of PCT and MR-proADM both in sepsis and in localized infections together with their contribution to effective antibiotic therapy has been evaluated. One hundred and eighty-two patients with bacterial infection has been enrolled: PCT and MR-proADM were measured at admission (T = 0), at 12-24 h (T = 1) and in the third or fifth day of antibiotic therapy (T = 3-5). ROC curve (receiver operating characteristic) and post-test probability were calculated. MR-proADM increased with the severity of the infection. PCT resulted significantly higher in sepsis than localized infection. After antibiotic therapy, PCT significantly decreased in localized respiratory infections and in sepsis, while MR-proADM decreased significantly after antibiotic therapy only in patients with severe sepsis/septic shock. The threshold values of PCT and MR-proADM were >0.1 ng/mL and >0.8 nmol/L, respectively. The combined use of PCT and MR-proADM increased the post-test probability of the diagnosis of bacterial infections compared to PCT alone. In conclusion, PCT and MR-proADM combination improves the diagnosis of bacterial infection and contribute to prognosis and antibiotic therapy effectiveness.

Viridans Group Streptococci clinical isolates: MALDI-TOF mass spectrometry versus gene sequence-based identification

Viridans Group Streptococci (VGS) species-level identification is fundamental for patients management. Matrix-assisted laser desorption ionization—time of flight mass spectrometry (MALDI-TOF MS) has been used for VGS identification but discrimination within the Mitis group resulted difficult. In this study, VGS identifications with two MALDI-TOF instruments, the Biotyper (Bruker) and the VITEK MS (bioMérieux) have been compared to those derived from tuf, soda and rpoB genes sequencing. VGS isolates were clustered and a dendrogram constructed using the Biotyper 3.0 software (Bruker). RpoB gene sequencing resulted the most sensitive and specific molecular method for S. pneumonia identification and was used as reference method. The sensitivity and the specificity of the VITEK MS in S. pneumonia identification were 100%, while the Biotyper resulted less specific (92.4%). In non pneumococcal VGS strains, the group-level correlation between rpoB and the Biotyper was 100%, while the species-level correlation was 61% after database upgrading (than 37% before upgrading). The group-level correlation between rpoB and the VITEK MS was 100%, while the species-level correlation was 36% and increases at 69% if isolates identified as S. mitis/S. oralis are included. The less accurate performance of the VITEK MS in VGS identification within the Mitis group was due to the inability to discriminate between S. mitis and S. oralis. Conversely, the Biotyper, after the release of the upgraded database, was able to discriminate between the two species. In the dendrogram, VGS strains from the same group were grouped into the same cluster and had a good correspondence with the gene-based clustering reported by other authors, thus confirming the validity of the upgraded version of the database. Data from this study demonstrated that MALDI-TOF technique can represent a rapid and cost saving method for VGS identification even within the Mitis group but improvements of spectra database are still recommended.

Laboratory Automation and Intra-Laboratory Turnaround Time: Experience at the University Hospital Campus Bio-Medico of Rome

Intra-laboratory turnaround time (TAT) is a key indicator of laboratory performance. Improving TAT is a complex task requiring staff education, equipment acquisition, and adequate TAT monitoring. The aim of the present study was to evaluate the intra-laboratory TAT after laboratory automation implementation (June 2013-June 2014) and to compare it to that in the preautomation period (July 2012-May 2013). Intra-laboratory TAT was evaluated both as the mean TAT registered and the percentage of outlier (OP) exams. The mean TAT was 36, 38, and 34 min during the study periods, respectively. These values respected the goal TAT established at 45 min. The OP, calculated at 45 min as well as at 60 min, decreased from 26 to 21 and from 11 to 5, respectively. From a focused analysis on blood count cell, troponin I, and prothrombin (PT) test, TAT improvement was more evident for tests requiring longer preanalytical process. The follow-up of TAT from June 2013 to June 2014 revealed the reduction of the mean TAT as well as of the OP exams after automation implementation and that automation more strongly affects the test in the preanalytical phase including centrifugation of the sample, such as troponin I and PT.

Procalcitonin and mid-regional pro-adrenomedullin test combination in sepsis diagnosis

BACKGROUND

The early diagnosis of sepsis plays a central role in patient management. Many mediators to be the cause of sepsis have been proposed. In the present study the combined measurement of procalcitonin (PCT) and mid-regional pro-adrenomedullin (MR-proADM) and their appropriate cut-off values in sepsis patients were evaluated.

METHODS

PCT and MR-proADM were measured with commercially available immunoluminometric assays (Brahms, Hennigsdorf, Germany) in 200 septic patients, 90 patients with SIRS and 30 healthy individuals. Data were analyzed with ROC curve analysis and likelihood ratios with the MedCalc 11.6.1.0 package.

RESULTS

Healthy controls and non-infectious SIRS were clearly distinguished from sepsis patients using the follow ing cut-off values: 0.30 ng/mL for PCT and 1 nmol/L for ADM. In the 200 septic patients the areas under the curve (AUCs) for PCT and MR-proADM were 0.921 and 0.977, respectively, with a statistically significant difference between the two areas of 0.0563 (p = 0.0002). Gram-positive, Gram-negative, yeast and polymicrobial sepsis patients showed different geometric means of the two biomarkers: this difference was relevant in Gram-positive sepsis and in yeast sepsis, 0.0819 (p = 0.0076) and 0.188 (p = 0.0062), respectively. The combined use of PCT and MR-proADM gave a post-test probability of 0.998 in the cohort of all septic patients. By test combination the post-test probability changed from 0.803 to 0.957 in Gram-positive sepsis and from 0.928 to 0.995 in yeast sepsis.

CONCLUSIONS

In conclusion, data from this study demonstrates that the combined use of PCT and MR-proADM, may substantially improve the early diagnosis of sepsis.

Antimicrobial Susceptibility, Biochemical and Genetic Profiles ofStaphylococcus haemolyticusStrains Isolated from the Bloodstream of Patients Hospitalized in Critical Care Units

Staphylococcus haemolyticus strains (n=20), responsible of blood stream infections, were consecutively isolated from patients hospitalized in two different wards at high risk of infection. Strains displayed high rate of resistance to oxacillin (90%). All strains but two with decreased susceptibility (MIC = 4 microg/mL), were sensitive to vancomycin. Ten strains were resistant to teicoplanin. Among the strains susceptible to glycopeptides, three displayed heteroresistance to vancomycin and seven to teicoplanin, when tested by Etest technique with 2 x McFarland inoculum. Biochemical reactions allowed to assign strains to eight biotypes, with 11 strains clustering under two main biotype A and biotype B. Pulsed-field-gel-electrophoresis (PFGE) identified 11 different PFGE-types. Seven strains grouping under the major PFGE-type 1 and three strains clustering in PFGE-type 2, closely correlated to biotype A and biotype B respectively. Seven teicoplanin-resistant isolates clustered in the PFGE-type 1, two in the PFGE-type 2 and one in PFGE-type 5. Therefore, teicoplanin-resistant strains were biochemically and genetically related and clonally distributed, despite different clones of S. haemolyticus circulated in the units during the study period.

Correlation of platelet reactivity and C-reactive protein levels to occurrence of peri-procedural myocardial infarction in patients undergoing percutaneous coronary intervention (from the ARMYDA-CRP study)

The incremental predictive value of high inflammatory status and high on-treatment platelet reactivity (HPR) on the occurrence of periprocedural myocardial infarction (PMI) after percutaneous coronary intervention (PCI) has not been characterized. The aim of this study was to evaluate the correlation of elevated C-reactive protein (CRP) level and/or HPR with the incidence of PMI in patients who undergo PCI. Five hundred consecutive patients treated with clopidogrel who underwent PCI had preprocedural measurement of CRP levels and platelet reactivity using the point-of-care VerifyNow P2Y12 assay. Elevated inflammatory status was defined as CRP >3 mg/L and HPR as P2Y12 reactivity units ≥240. The primary end point was the incidence of PMI in relation to platelet reactivity and/or inflammatory status. Rates of PMI were increased in patients with CRP levels >3 mg/L (10.9% vs 4.6% in those with normal levels, odds ratio 2.4, 95% confidence interval 1.2 to 4.5, p = 0.015) and in patients with HPR (11% vs 5.5% in those without HPR, odds ratio 2.2, 95% confidence interval 1.2-4.4, p = 0.018). The occurrence of PMI was highest in the subgroup with HPR and high inflammatory status (16.6% vs 3.6% in patients with CRP ≤3 mg/L and P2Y12 reactivity units <240, odds ratio 4.3, 95% confidence interval 1.5 to 12.6, p = 0.008). HPR in association with elevated CRP levels resulted in a significant increase in the discriminatory power of a model including clinical and procedural variables in predicting PMI (area under the curve 0.811, p = 0.041). In conclusion, in patients who undergo PCI, baseline stratification according to platelet reactivity and inflammatory status may identify those at higher risk for PMI.

Does anticonvulsant treatment influence pain perception in epileptic children?

BACKGROUND

The aims of our study were to evaluate pain perception in epileptic children and to establish the influence of anticonvulsant drugs on pain perception.

METHODS

The study involved 40 children, 30 with epilepsy and 10 healthy control subjects. In the group of epileptic children, 10 were not treated and 20 assumed a single drug. From all children of each group, one sample of saliva was collected through a noninvasive device 15 minutes before (t0), during (t1), and 15 minutes after (t2) blood withdrawal, and salivary α-amylase activity was then determined.

RESULTS

No statistically significant difference was found at t0 and at t1, indicating that in both groups venipuncture equally induced a state of stress. Conversely, at t2 a statistically significant difference (p = 0.0195) was found, suggesting that epileptic children presented a greater sensitization to pain and a slower recovery from stress. Comparing furthermore data obtained in children with epilepsy not treated with those registered in treated ones, we found a statistically significant difference at t0 (p = 0.012), at t1 (p = 0.037), and at t2 (p = 0.011).

CONCLUSIONS

Anticonvulsant drugs do not seem to influence pain perception and enzymatic activity levels in epileptic patients.

Insights into airway infections by enterococci: a review

Enterococcus is an uncommon but emerging agent of upper and lower airway diseases, including sinuses, trachea, bronchi, lung and pleural infections. In particular, pneumonia and thoracic empyema may jeopardize the clinical outcome of compromised, hospitalized hosts, as well as affect outpatients. Treatment may feel the effects of inherent and acquired resistances such organisms show to commonly used drugs, with the spread of glycopeptide/vancomycin resistant enterococci (GRE/VRE, respectively) being of serious concern. With this work, we want to unearth the impact of members of the genus in the ambit of respiratory infections, and to increase the consciousness of their role as resourceful pathogens for human airways. Also, we are revising patents of interest aiming to timely screen GRE and soon provide clinicians with speciation and glycopeptide resistances.

About a bloodstream Corynebacterium striatum isolate

Corynebacterium striatum is often dismissed as a contaminant when cultivated from blood samples; indeed, it is a skin saprophyte that may therefore be introduced into the clinical specimen accidentally. Nevertheless, the organism can be responsible for true bacteraemias, and multidrug resistance spread among nosocomial strains is of increasing concern. Specific criteria for testing have not been defined yet, but we however suggest to report clear resistances (i.e. absence of any inhibition zones with the disc test), in order to try to understand this species behaviour under antibiotic exposure. In this context, features of a blood isolate (strain DSM 45711) are here depicted.

Real-time polymerase chain reaction with melting analysis of positive blood culture specimens in bloodstream infections: diagnostic value and turnaround time

A Real-time polymerase chain reaction (PCR) with melting analysis was devised to target bacterial and fungal genes together with the most prevalent antimicrobial resistance genes in 250 positive blood culture broths. This method allowed the blood culture cultivated pathogens to be classified into clinically relevant groups such as Enterobacteriaceae, oxidase-positive bacilli, oxidase-positive coccobacilli, S. aureus and yeast. Enterococci and streptococci could be distinguished from CoNS only by the Gram stain. Gram-positive bacilli were discriminated from Gram-positive cocci by Gram stain. Furthermore, the most important antimicrobial resistant genes such as mecA, vanA, bla TEM , bla SHV and bla CTX-M could be identified. All results were obtained with a turnaround time of three hours from the moment of blood culture positivity compared to 24-72 hours for phenotypic methods. In conclusion, the proposed approach can allow the clinician to implement proper early management of sepsis patients.

Increased carotid thickness in subjects with recently-diagnosed diabetes from rural Cameroon

BACKGROUND

We have recently shown a high prevalence of diabetes and obesity in rural Cameroon, despite an improved lifestyle. Diabetes in rural Africa remains underdiagnosed and its role in increasing risk of atherosclerosis in these populations is unknown. We investigated the prevalence of carotid atherosclerosis and cardiovascular risk factors in a population of subjects with recently-diagnosed diabetes from rural Cameroon.

METHODOLOGY/PRINCIPAL FINDINGS

In a case-control study, carotid intima-media thickness (IMT) was measured in 74 subjects with diabetes (diagnosed <2 years), aged 47-85 and 109 controls comparable for age and sex. Subjects were recruited during a health campaign conducted in April 2009. Blood glucose control (HbA1c, fasting blood glucose) and major cardiovascular risk factors (complete lipid panel, blood pressure) were also measured. Mean carotid IMT was higher in subjects with diabetes than healthy controls at each scanned segment (common, internal carotid and bulb) (P<0.05), except the near wall of the left bulb. Vascular stiffness tended to be higher and pressure-strain elastic modulus of the left carotid was increased in subjects with diabetes than controls (P<0.05), but distensibility was similar between the two groups. At least one plaque >0.9 mm was found in 4%, 45.9% and 20% of diabetic subjects at the common, bulb or internal carotid, respectively. Only 25% of patients had an HbA1c<7%, while over 41.6% presented with marked hyperglycemia (HbA1c>9%). The prevalence of diabetic subjects with abnormal levels of LDL-cholesterol, triglycerides, HDL-cholesterol or blood pressure was 45%, 16.6%, 15% and 65.7%, respectively.

CONCLUSIONS

Carotid thickness is increased in subjects with diabetes from a rural area of Cameroon, despite the relatively recent diagnosis. These findings and the high rate of uncontrolled diabetes in this population support the increasing concern of diabetes and cardiovascular diseases in African countries and indicate the need for multifaceted health interventions in urban and rural settings.

Comparison of safety and efficacy of bivalirudin versus unfractionated heparin in high-risk patients undergoing percutaneous coronary intervention (from the Anti-Thrombotic Strategy for Reduction of Myocardial Damage During Angioplasty-Bivalirudin vs Heparin study)

Bivalirudin, a direct thrombin inhibitor, is as effective as unfractionated heparin (UFH), with decreased bleeding in patients with acute coronary syndromes who undergo percutaneous coronary intervention (PCI). The aim of this study was to evaluate the effectiveness of bivalirudin versus UFH in selected PCI patients at high bleeding risk. Four hundred one consecutive patients who underwent PCI fulfilling ≥ 1 enrollment criterion (age >75 years, chronic renal failure, and diabetes mellitus) were randomized to bivalirudin (bolus 0.75 mg/kg followed by infusion during the procedure; n = 198) or UFH (75 IU/kg; n = 203). In the overall population, 39% were aged >75 years, 22% had renal failure, 63% had diabetes, and 29% had acute coronary syndromes. The primary efficacy end point was the 30-day incidence of major adverse cardiac events (cardiac death, myocardial infarction, stent thrombosis, or target vessel revascularization). The primary safety end point was the occurrence of any bleeding or entry-site complications after PCI. All patients were preloaded with clopidogrel 600 mg. Glycoprotein IIb/IIIa inhibitors were used at the operators' discretion. Thirty-day major adverse cardiac event rates were 11.1% in the bivalirudin group and 8.9% in the UFH group (p = 0.56); the primary efficacy end point was reached mainly because of periprocedural myocardial infarction; 1 patient in the bivalirudin group had stent thrombosis. Occurrence of the primary safety end point was 1.5% in the bivalirudin group and 9.9% in the UFH group (p = 0.0001); this benefit was essentially driven by the prevention of entry-site hematomas >10 cm (0.5% vs 6.9%, p = 0.002). In conclusion, Anti-Thrombotic Strategy for Reduction of Myocardial Damage During Angioplasty-Bivalirudin vs Heparin (ARMYDA-7 BIVALVE) indicates that bivalirudin, compared with UFH, causes significantly lower bleeding and has a similar incidence of major adverse cardiac events in patients with older age, diabetes mellitus, or chronic renal failure who undergo PCI.

Potential novel therapeutic strategies in cystic fibrosis: antimicrobial and anti-biofilm activity of natural and designed α-helical peptides against Staphylococcus aureus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia

BACKGROUND

Treatment of cystic fibrosis-associated lung infections is hampered by the presence of multi-drug resistant pathogens, many of which are also strong biofilm producers. Antimicrobial peptides, essential components of innate immunity in humans and animals, exhibit relevant in vitro antimicrobial activity although they tend not to select for resistant strains.

RESULTS

Three α-helical antimicrobial peptides, BMAP-27 and BMAP-28 of bovine origin, and the artificial P19(9/B) peptide were tested, comparatively to Tobramycin, for their in vitro antibacterial and anti-biofilm activity against 15 Staphylococcus aureus, 25 Pseudomonas aeruginosa, and 27 Stenotrophomonas maltophilia strains from cystic fibrosis patients. All assays were carried out in physical-chemical experimental conditions simulating a cystic fibrosis lung. All peptides showed a potent and rapid bactericidal activity against most P. aeruginosa, S. maltophilia and S. aureus strains tested, at levels generally higher than those exhibited by Tobramycin and significantly reduced biofilm formation of all the bacterial species tested, although less effectively than Tobramycin did. On the contrary, the viability-reducing activity of antimicrobial peptides against preformed P. aeruginosa biofilms was comparable to and, in some cases, higher than that showed by Tobramycin.

CONCLUSIONS

The activity shown by α-helical peptides against planktonic and biofilm cells makes them promising "lead compounds" for future development of novel drugs for therapeutic treatment of cystic fibrosis lung disease.

Bisphosphonates: from preclinical evidence to survival data in the oncologic setting

Bisphosphonate therapy has become a standard of therapy for patients with malignant bone disease. In vivo pre-clinical data suggest that bisphosphonates may exert an antitumor effect and preliminary clinical data show promising activity on metastatic disease in cancer patients. This review will describe the pre-clinical evidence of action of bisphosphonates on osteoclasts and tumor cells, in both in vitro and animal models. In addition, the effects of principal bisphosphonates on skeletal disease progression in patients with cancers in different sites, including breast cancer, prostate cancer and non-small cell lung cancer will be reported. The preliminary clinical data from retrospective trials on the effect of bisphosphonates on survival will be described and the ongoing adjuvant phase III trial will be analyzed. This review will describe the preliminary clinical evidences from prospective studies on the effect of zoledronic acid treatment on the prevention of bone metastases.

Comparative evaluation of the Vitek-2 Compact and Phoenix systems for rapid identification and antibiotic susceptibility testing directly from blood cultures of Gram-negative and Gram-positive isolates

We performed a comparative evaluation of the Vitek-2 Compact and Phoenix systems for direct identification and antimicrobial susceptibility testing (AST) from positive blood culture bottles in comparison to the standard methods. Overall, 139 monomicrobial blood cultures, comprising 91 Gram-negative and 48 Gram-positive isolates, were studied. Altogether, 100% and 92.3% of the Gram-negative isolates and 75% and 43.75% of the Gram-positive isolates showed concordant identification between the direct and the standard methods with Vitek and Phoenix, respectively. AST categorical agreements of 98.7% and 99% in Gram-negative and of 96.2% and 99.5% in Gram-positive isolates with Vitek and Phoenix, respectively, were observed. In conclusion, direct inoculation procedures for Gram-negative isolates showed an excellent performance with both automated systems, while for identification of Gram-positive isolates they proved to be less reliable, although Vitek provided acceptable results. This approach contributes to reducing the turnaround time to result of blood cultures, with a positive impact on patient care.

Phenotypic and genotypic characterization of Stenotrophomonas maltophilia isolates from patients with cystic fibrosis: genome diversity, biofilm formation, and virulence

Background

Stenotrophomonas maltophilia is emerging as one of the most frequently found bacteria in cystic fibrosis (CF) patients. In the present study, phenotypic and genotypic traits of a set of 98 isolates of S. maltophilia obtained from clinical (CF and non-CF patients) and environmental sources were comparatively evaluated.

Results

S. maltophilia exhibited a high level of genomic diversity in both CF and non-CF group, thus possibly allowing this bacterium to expand its pathogenic potentials. Strains sharing the same pulsotype infected different patients, thus likely indicating the occurrence of clonal spread or acquisition by a common source. CF isolates differed greatly in some phenotypic traits among each other and also when compared with non-CF isolates, demonstrating increased mean generation time and susceptibility to oxidative stress, but reduced ability in forming biofilm. Furthermore, in CF isolates flagella- and type IV pili-based motilities were critical for biofilm development, although not required for its initiation. Sequential isogenic strains isolated from the same CF patient displayed heterogeneity in biofilm and other phenotypic traits during the course of chronic infection. CF and non-CF isolates showed comparable virulence in a mouse model of lung infection.

Conclusions

Overall, the phenotypic differences observed between CF and non-CF isolates may imply different selective conditions and persistence (adaptation) mechanisms in a hostile and heterogeneous environment such as CF lung. Molecular elucidation of these mechanisms will be essential to better understand the selective adaptation in CF airways in order to design improved strategies useful to counteract and eradicate S. maltophilia infection.

Early magnesium modifications as a surrogate marker of efficacy of cetuximab-based anticancer treatment in KRAS wild-type advanced colorectal cancer patients

BACKGROUND

KRAS wild-type mutational status is necessary but not sufficient to get benefit from epidermal growth factor receptor inhibition. Predictive markers are currently being evaluated. In this study, we investigated early hypomagnesemia as a predictor of efficacy and outcome in terms of time to progression (TtP) and overall survival (OS) in a cohort of patients affected by advanced colorectal adenocarcinoma KRAS wild-type cetuximab-treated.

PATIENTS AND METHODS

One hundred and forty-three patients affected by stage IV colorectal adenocarcinoma KRAS wild type receiving cetuximab + irinotecan (CTX+IRI) as third-line anticancer treatment and resistant to oxaliplatin- and irinotecan-based chemotherapy were retrospectively included. Magnesium plasma levels were measured before the first day and 7, 14, 21 and 28 days after CTX+IRI infusion.

RESULTS

The median magnesium basal value showed a statistically significant decrease after the start of CTX+IRI treatment (at 28 days, P < 0.0001). Patients with an early decrease of magnesium levels >50% compared with the basal level had a higher tumor response rate (55.8% versus 16.7%, P < 0.0001), a longer TtP (6.3 versus 3.6, P < 0.0001) and a longer median OS (11.0 versus 8.1, P = 0.002).

CONCLUSIONS

We have shown that early hypomagnesemia could be a predictor of efficacy and outcome in those patients. Magnesium circulating level is an easy and inexpensive biomarker to routinely be detected in patients treated with cetuximab.

Angiogenic cytokines in patients undergoing antiviral treatment for chronic hepatitis C virus infection

During chronic liver disease (CLD), angiogenesis participates in the fibrogenic process. Herein, we aimed at verifying the on-treatment kinetics of serum vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) in hepatitis C virus (HCV) patients undergoing antiviral therapy. Forty-three HCV patients treated with pegylated-interferon/ribavirin and 26 controls were studied. Serum VEGF and Ang-2 were determined before treatment, at different time points during treatment, and at follow-up after treatment. Thirty and 13 patients were sustained virological responder (SVR) and No-SVR, respectively. Patients showed increased Ang-2 levels [504 (368-720) versus 449 (389-483) pg/mL, P < 0.05], and equivalent VEGF levels [271 (193-377) versus 274 (199-324) pg/mL, P = 0.6], with respect to controls. By univariate analysis, stage of fibrosis was associated with Ang-2 levels (odds ratio 4.25, P < 0.05). In SVR patients VEGF levels showed a progressive reduction (P < 0.05) but returned to pretherapy levels at follow-up, and Ang-2 levels showed an opposite progressive increase, being significantly reduced at follow-up (P < 0.01). No significant modifications in VEGF and Ang-2 levels were observed in No-SVR. We conclude that, in patients with HCV-CLD, Ang-2 serum levels are associated with fibrosis and reduced at follow-up in SVR patients. On-treatment, VEGF and Ang-2 serum levels undergo different-sided modifications only in SVR patients, possibly expressing the vascular remodeling occurring early after viral clearance.

Analysis of methods commonly used for glycopeptide and oxazolidinone susceptibility testing in Enterococcus faecium isolates

The susceptibility to teicoplanin, vancomycin and linezolid of 30 clinical isolates of Enterococcus faecium was tested by Vitek 2, Phoenix, Etest, broth microdilution and disc diffusion tests. The vanA and vanB resistance genes and the 23S rRNA gene G2576T mutation were detected by PCR and PCR-RFLP, respectively. Resistance rates to teicoplanin ranged from 3 % for Vitek 2 to 57.6 % for the Phoenix test, and those to vancomycin ranged from 56.7 % for Vitek 2 to 86.7 % for the Phoenix test. Only two out of 25 strains carrying the vanA gene were univocally recognized as the VanA phenotype. The only strain with the G2576T mutation did not carry the vanA gene and showed resistance to linezolid by the disc diffusion, Vitek 2 and broth dilution methods (MIC >8 μg ml−1), but was susceptible when tested with the Phoenix test and Etest (MIC ≤4 μg ml−1). Therefore, the resistance to glycopeptides and linezolid was not univocally detected by the susceptibility testing methods used in this study.

A case of Lactobacillus casei bacteraemia associated with aortic dissection: is there a link?

We describe an unusual case of Lactobacillus casei bacteraemia in a heavy dairy consumer woman, with a one month history of low grade fever and admitted to our hospital for sudden onset of severe thoracic pain due to dissection of the aortic arch and ascending aorta. The patient underwent four weeks of intravenous ampicillin (2 g every 4 hours) followed by 2 weeks of oral amoxicillin (1 g every 8 hours) with resolution of fever, thoracic pain and progression of aortic disease. On the basis of the patient's symptoms, a possible penetration of L. casei in an aortic wall defect with development of aortic dissection is hypothesized.

NOD2/CARD15 polymorphisms impair innate immunity and increase susceptibility to gastric cancer in an Italian population

In the present case-control study we investigated the potential role of CARD15 R702W, G908R, and 1007fs polymorphisms in Italian gastric cancer patients. The study population consisted of 170 gastric cancer patients and 156 controls. Unconditional regression (odds ratios and 95% confidence interval) was used to investigate the association of the studied polymorphisms with gastric cancer. Higher allele frequencies of R702W and 1007fs polymorphisms were observed in patients with gastric cancer compared with controls (8.53 vs 2.3 and 9.4 vs 0.7, respectively). CARD15 R702W and 1007fs polymorphisms were significantly correlated with gastric cancer incidence (p < 0.0001, p < 0.0001, respectively). No correlation was found upon analyzing the G908R single nucleotide polymorphism (SNP). Our study reports an increased susceptibility to gastric cancer in Italian populations when R702W and 1007fs polymorphisms in the coding region of CARD15 are present. The interaction between NOD-induced proinflammatory cytokines on gastric mucosa and environmental carcinogens could represent one of the mechanisms by which CARD15 polymorphisms increase the susceptibility to gastric cancer. Meta-analyses of these SNPs and further analyses of additional polymorphisms/haplotypes in NOD genes will help determine their role in carcinogenesis.

Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms in gastric cancer of intestinal and diffuse histotypes

In the present study we investigated the potential role of Toll-like receptor 4 (TLR-4) Asp299Gly and Thr399Ile polymorphisms as risk factors in the development of gastric cancer. TLR-4 Asp299Gly and Thr399Ile polymorphisms were investigated in 171 Italian patients with sporadic gastric cancer and in 151 controls. Unconditional regression (odds ratio and 95% confidence intervals) were used to investigate the association of the studied polymorphisms with gastric cancer. TLR-4 Thr399Ile polymorphism is linked with an increased susceptibility to gastric cancer (P = 0.023 and hazard ratio = 3.62). No significant association for TLR-4 Asp299Gly polymorphism was found. In the subgroup of patients with intestinal-type gastric cancer, a significant risk of gastric cancer was associated with TLR-4 Thr399Ile genotype (P = 0.006). Our results demonstrated that TLR-4 Thr399Ile polymorphism is linked with an increased susceptibility to gastric cancer. An increased risk for intestinal gastric cancer in carriers of the TLR4 Thr399Ile allele was observed. Future epidemiological studies should consider the possible interactions between proinflammatory genotypes (such as TLR and interleukin-1R polymorphisms) and other risk factors for cancer such as dietary habits and/or exposure to environmental carcinogens.