Evaluation of carbapenem-resistant Enterobacteriaceae in an Italian setting: report from the trench.

The spread of carbapenem resistant Enterobacteriaceae (CRE) has recently become a matter of concern in public health, mainly due to the wide distribution of carbapenemase genes. Italy is a country considered endemic for the spread of blaKPC Klebsiella pneumoniae (KP). The aim of this study was to depict the epidemiological trend of CRE in one Italian hospital over a long period (3 years surveillance, from May 2011 to April 2014). Based on defined MIC cut-off for specific carbapenems, 164 strains isolated from 146 different patients were analyzed both phenotypically and genotypically to establish the resistance genes. Molecular typing was performed using the RAPD technique. 77 strains were demonstrated to harbor the blaKPC gene (73 KP, 4 Escherichia coli - EC), 51 strains the blaVIM gene (44 KP, 3 EC, 2 Enterobacter cloacae and 2 Klebsiella oxytoca), 8 the blaNDM gene (3 KP, 4 EC and one Providencia stuartii), 3 the blaOXA-48 gene (2 KP, 1 EC), whereas 25 out of the 164 isolates (of different genera and species) had a negative multiplex-PCR amplification for all the targets tested. 39 out of the 164 strains analyzed (23.8%) revealed discrepancies between the MICs obtained with automated instrument and gradient MICs of more than two logs of difference; the broth microdilution provided a better agreement with the results obtained with the gradient MIC. The use of RAPD allowed to distinguish different clusters, closely related, both for blaKPC and for blaVIM KP.

Comparison of the Staphylococcus QuickFISH BC test with the tube coagulase test performed on positive blood cultures for evaluation and application in a clinical routine setting.

Many studies demonstrate that delayed proper therapy in bloodstream infections caused by Staphylococcus aureus increases the mortality rate, emphasizing the need to shorten the turnaround time for positive blood cultures. Different techniques are currently available, from phenotypic methods to more complex tests such as matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF), real-time PCR (RT-PCR), and fluorescence in situ hybridization using peptide nucleic acid probes (PNA FISH). This study evaluated the performance of the Staphylococcus QuickFISH BC test (QFT), a novel FISH methodology, compared with the direct tube coagulase test (DTCT) on blood cultures exhibiting Gram-positive cocci in clusters. A total of 173 blood cultures collected from 128 different patients were analyzed using the DTCT, evaluated after both 4 and 24 h, and the QFT. A total of 179 isolates were identified using the Vitek2 system. Thirty-five out of 35 Staphylococcus aureus were correctly identified by the QFT (sensitivity = 100%), with a specificity of 100% (no green fluorescence was detected for strains different from S. aureus). The DTCT was positive after 4 h for 28 out of the 35 samples (sensitivity = 80%) and after 24 h for 31 out of the 35 samples (sensitivity = 88.57%). Among the remaining 144 isolates, one was then identified as Corynebacterium striatum and two as Micrococcus luteus. QFT identified 139 out of the 141 coagulase-negative staphylococci (CoNS) (sensitivity = 98.58%), showing again a specificity of 100% (no fluorescent red signals were detected for strains different from CoNS). We also discuss also the implementation process of this methodology in our setting, with particular emphasis on the workflow and the cost-effectiveness.

Comparative study of the in vitro activity of various antifungal drugs against Scedosporium spp. in aerobic and hyperbaric atmosphere versus normal atmosphere.

INTRODUCTION: Scedosporium spp. have been observed with increasing frequency over the last decade in immunocompromised patients and trauma patients. This mould is often multi-drug resistant and its mortality rate remains very high. AIM: The primary goal of this study was to obtain data concerning the in vitro susceptibility of 13 Scedosporium strains comparing the in vitro incubation in aerobic versus hyperbaric conditions. MATERIALS AND METHODS: Chemosensitivity of thirteen Scedosporium strains was evaluated after a 72h-incubation in a normoxic (21% O2) normobaric (1 ATA) atmosphere versus a hyperoxic (100% O2) hyperbaric (2-3 ATA), and after a re-incubation at room temperature for an additional 72h. RESULTS: All S. apiospermum and S. prolificans strains showed no growth after incubation in hyperbaric hyperoxic atmosphere. However, when plates were then maintained at room temperature in aerobic conditions, growth was systematically observed from 36 to 96h, and Minimal inhibitory concentration (MIC) values were the same obtained after incubation in aerobic conditions. CONCLUSIONS: These results suggest impressive in vitro fungistatic activity of the hyperoxic hyperbaric atmosphere, even if its effect is strictly time-dependent. This preliminary in vitro study has potential clinical relevance because it focuses on examining in vitro combination therapy using hyperoxic hyperbaric conditions plus a single antifungal agent, rather than using combinations of different antifungal drugs, to potentially increase the antifungal activity.

In vitro activity effects of twelve antibiotics alone and in association against twenty-seven Enterococcus faecalis strains isolated from Italian patients with infective endocarditis: high in vitro synergistic effect of the association ceftriaxone-fosfomycin.

BACKGROUND: In 2004-2008, the epidemiological and clinical Infective Endocarditis Study Group (SEI) evaluated 852 cases of infective endocarditis. Staphylococcus aureus was the main involved pathogen (24.5%) and Enterococcus faecalis etiology was described in 11% of the cases. The aim of this study was to evaluate the in vitro activity of 12 antibiotics alone and in association against 27 strains of E. faecalis isolated from blood cultures of patients with infective endocarditis. RESULTS: The results showed high in vitro activity of tigecycline, daptomycin and linezolid. A high synergistic effect was obtained with the association ceftriaxone-fosfomycin [fractional inhibitory concentration (FIC)(50) = 0.34, FIC(90) = 0.78]. Furthermore, ceftriaxone plus ampicillin presented additive results (FIC(50) = 0.66, FIC(90) = 1.00), and ceftriaxone plus fosfomycin and ceftriaxone plus ampicillin were significantly more active in vitro than each drug alone. The efficacy of ceftriaxone plus fosfomycin was confirmed by the association testing using the broth dilution technique. CONCLUSION: Fosfomycin seems particularly significant and its association with ceftriaxone could be considered as a useful therapeutic option in medical treatment of E. faecalis infective endocarditis.

Two-dimensional and Doppler echocardiographic findings in healthy non-sedated red-eared slider terrapins (Trachemys scripta elegans).

Echocardiographic evaluation was performed in six healthy young adult non-sedated terrapins (Trachemys scripta elegans). The best imaging quality was obtained through the right cervical window. Base-apex inflow and outflow views were recorded, ventricular size, ventricular wall thickness and ventricular outflow tract were measured, and fractional shortening was calculated. Pulsed-wave Doppler interrogation enabled the diastolic biphasic atrio-ventricular flow and the systolic ventricular outflow patterns to be recorded. The following Doppler-derived functional parameters were calculated: early diastolic (E) and late diastolic (A) wave peak velocities, E/A ratio, ventricular outflow systolic peak and mean velocities and gradients, Velocity-Time Integral, acceleration and deceleration times, and Ejection Time. For each parameter the mean, standard deviation and 95% confidence interval were calculated. Echocardiography resulted as a useful and easy-to-perform diagnostic tool in this poorly known species that presents difficulties during evaluation.