FLT3-targeted therapy restores GATA1 pathway function in NPM1/FLT3-ITD mutated acute myeloid leukaemia

One-third of newly diagnosed adult acute myeloid leukaemia (AML) carry FLT3 mutations, which frequently occur together with nucleophosmin (NPM1) mutations and are associated with worse prognosis. FLT3 inhibitors are widely used in clinics with limitations due to drug resistance. AML cells carrying FLT3 mutations in both mouse models and patients present low expression of GATA1, a gene involved in haematopoietic changes preceding AML. Here, we show that FLT3 inhibition induces cellular responses and restores the GATA1 pathway and functions in NPM1/FLT3-ITD mutated AML, thus providing a new mechanism of action for this drug.

Venous thromboembolism in critically ill patients affected by ARDS related to COVID-19 in Northern-West Italy

OBJECTIVE

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that was first reported in Wuhan, China, and has subsequently spread worldwide. An association between increased venous thromboembolism in patients with pneumonia-related to COVID-19 has not yet been well described.

PATIENTS AND METHODS

We aimed to illustrate cases of pulmonary thromboembolism in patients with acute respiratory distress syndrome related to COVID-19 treated in our intensive care unit. The medical records of patients affected by COVID-19 with acute respiratory distress syndrome in our institute from 1/3/2020 to 31/3/2020 were retrospectively reviewed.

RESULTS

Our center registered a high prevalence of thromboembolic events among 62 patients affected by acute respiratory distress syndrome related to COVID-19 despite a regular antithrombotic prophylaxis. Out of these, 32 patients were transferred to other hospitals, and 30 were treated in our center. Venous thromboembolism was registered in 12 (19.3%) cases. In particular, 11 diagnoses of pulmonary embolism and 1 diagnosis of deep vein thrombosis were formulated. We described a case series of venous thromboembolism in nine patients treated in our Intensive Care Unit (ICU). Main pulmonary arteries were always involved in these patients. None of them died.

CONCLUSIONS

In conclusion, critically ill patients with ARDS related to COVID-19 may have an increased risk of VTE that could be a leading cause of mortality. These patients require a high index of clinical suspicion and an accurate diagnostic approach, in order to immediately start an appropriate anticoagulant treatment.

0156 Activation of Glutamatergic PPT Neurons and Their Projections Promotes Arousal, and Distinct Wake Behaviors

Introduction

The pedunculopontine tegmental (PPT) region in the brainstem is crucial for the regulation of sleep/wake states. We recently showed that chemogenetic activation of glutamatergic PPT neurons promotes wakefulness for several hours. Here we used optogenetic activation of these neurons to further investigate the mechanisms and pathways through which PPT glutamatergic neurons produce wakefulness.

Methods

Using vGlut2-cre mice, we transfected neurons in the PPT region with a viral vector coding for cre-dependent ChR2 tagged with fluorescent mCherry and implanted bilateral optical fibers above the PPT nuclei as well as EEG/EMG leads. Two weeks later, we administered blue laser light to activate ChR2-expressing neurons and recorded sleep/wake states.

Results

Activation of ChR2-expressing glutamatergic neurons during NREM sleep rapidly elicited wakefulness in a stimulation-frequency dependent manner, with higher frequencies producing wake more quickly and with longer duration. Random, automated stimulation for 10 s at 5 Hz over 24 h revealed that activation of glutamatergic PPT neurons produces rapid arousals form NREM sleep. Importantly, stimulation did not wake mice from REM sleep, suggesting that glutamatergic PPT signaling does not interfere with REM sleep. To map the target areas through which PPT glut neurons produce wakefulness, we used a viral tracer to visualize PPT glutamatergic projections, and then optogenetically stimulated terminals in 1) basal forebrain, 2) lateral hypothalamus, 3) thalamus, and 4) substantia nigra. We found that stimulating terminals in all of these regions woke mice from NREM sleep, and stimulating terminals in the basal forebrain and lateral hypothalamus produced a number of active wake behaviors such as locomotion. In contrast, stimulation of PPT glut soma and terminals in the thalamus and substantia nigra results mainly in quiet wakefulness.

Conclusion

Glutamatergic PPT neurons potently promote arousal from NREM sleep but not REM sleep, and the resulting wake behavior is modulated by different projection targets.

Support

NIH grant P01 - HL095491

Signatures of de-domestication in autochthonous pig breeds and of domestication in wild boar populations from MC1R and NR6A1 allele distribution

Autochthonous pig breeds are usually reared in extensive or semi-extensive production systems that might facilitate contact with wild boars and, thus, reciprocal genetic exchanges. In this study, we analysed variants in the melanocortin 1 receptor (MC1R) gene (which cause different coat colour phenotypes) and in the nuclear receptor subfamily 6 group A member 1 (NR6A1) gene (associated with increased vertebral number) in 712 pigs of 12 local pig breeds raised in Italy (Apulo-Calabrese, Casertana, Cinta Senese, Mora Romagnola, Nero Siciliano and Sarda) and south-eastern European countries (Krškopolje from Slovenia, Black Slavonian and Turopolje from Croatia, Mangalitsa and Moravka from Serbia and East Balkan Swine from Bulgaria) and compared the data with the genetic variability at these loci investigated in 229 wild boars from populations spread in the same macro-geographic areas. None of the autochthonous pig breeds or wild boar populations were fixed for one allele at both loci. Domestic and wild-type alleles at these two genes were present in both domestic and wild populations. Findings of the distribution of MC1R alleles might be useful for tracing back the complex genetic history of autochthonous breeds. Altogether, these results indirectly demonstrate that bidirectional introgression of wild and domestic alleles is derived and affected by the human and naturally driven evolutionary forces that are shaping the Sus scrofa genome: autochthonous breeds are experiencing a sort of 'de-domestication' process, and wild resources are challenged by a 'domestication' drift. Both need to be further investigated and managed.

Epidemiology and Microbiology of Skin and Soft Tissue Infections: Preliminary Results of a National Registry

Skin and soft tissue infections (SSTIs) represent a wide range of clinical conditions characterized by a considerable variety of clinical presentations and severity. Their aetiology can also vary, with numerous possible causative pathogens. While other authors previously published analyses on several types of SSTI and on restricted types of patients, we conducted a large nationwide surveillance programme on behalf of the Italian Society of Infectious and Tropical Diseases to assess the clinical and microbiological characteristics of the whole SSTI spectrum, from mild to severe life-threatening infections, in both inpatients and outpatients. Twenty-five Infectious Diseases (ID) Centres throughout Italy collected prospectively data concerning both the clinical and microbiological diagnosis of patients affected by SSTIs via an electronic case report form. All the cases included in our database, independently from their severity, have been managed by ID specialists joining the study while SSTIs from other wards/clinics have been excluded from this analysis. Here, we report the preliminary results of our study, referring to a 12-month period (October 2016-September 2017). During this period, the study population included 254 adult patients and a total of 291 SSTI diagnoses were posed, with 36 patients presenting more than one SSTIs. The type of infection diagnosed, the aetiological micro-organisms involved and some notes on their antimicrobial susceptibilities were collected and are reported herein. The enrichment of our registry is ongoing, but these preliminary results suggest that further analysis could soon provide useful information to better understand the national epidemiologic data and the current clinical management of SSTIs in Italy.

Encuesta de datos demográficos y fenotípicos de razas locales de cerdos del proyecto TREASURE

Este trabajo presenta los resultados de una encuesta de datos demográficos y fenotípicos de 20 razas locales de cerdos en estudio en el proyecto H2020 TREASURE y incluí información de: parámetros demográficos, características morfológicas principales, parámetros reproductivos, informaciones adicionales a nivel de los efectivos (ex. Temperamento, instalaciones, prácticas de cubrición), orígenes y desarrollo de las razas. Casi todas las razas (18 de 20) tienen libro genealógico, aunque su fecha de inicio varía mucho (de 1980 a 2006). El número de hembras reproductoras varía de 24 (Moravka) a más de 200 mil cabezas (Ibérico). La relación macho/hembra varía mucho con los valores más altos verificados en las razas italianas muy probablemente debido a una política diferente relativamente al registro de animales. Casi todas las razas tienen programas de conservación, aunque pocas están interesadas en otras técnicas de conservación y sólo en menos que 5 razas los datos relativos a número de efectivos y de coeficiente de consanguinidad están fácilmente disponibles. Los valores medios para números de pezones, tamaño de camada y lechones destetados son de 12, 8 y 6, respectivamente con un grande potencial para mejora. El escenario descrito es altamente diversificado y esta colecta de datos representa el punto de partida para una marca colectiva debajo del parasol del proyecto TREASURE.

Design, synthesis and antibacterial evaluation of a polycationic calix[4]arene derivative alone and in combination with antibiotics

The growing antibiotic resistance phenomenon continues to stimulate the search for new compounds and strategies to combat bacterial infections. In this study, we designed and synthesized a new polycationic macrocyclic compound (2) bearing four N-methyldiethanol ammonium groups clustered and circularly organized by a calix[4]arene scaffold. The in vitro activity of compound 2, alone and in combination with known antibiotics (ofloxacin, chloramphenicol or tetracycline), was assessed against strains of Staphylococcus aureus (ATCC 6538 and methicillin-resistant isolate 15), S. epidermidis (ATCC 35984 and methicillin-resistant isolate 57), and Pseudomonas aeruginosa (ATCC 9027 and antibiotic-resistant isolate 1). Calix[4]arene derivative 2 showed significant antibacterial activity against ATCC and methicillin-resistant Gram positive Staphylococci, improved the stability of tetracycline in water, and in combination with antibiotics enhanced the antibiotic efficacy against Gram negative P. aeruginosa by an additive effect.

Renal haemodynamics and severity of carotid atherosclerosis in hypertensive patients with and without impaired renal function

BACKGROUND AND AIM

Renal resistance index (RRI), assessed by Duplex-Doppler sonography, has been classically considered as a mere expression of intrarenal vascular resistance. Recent studies, however, have showed that RRI is also influenced by upstream factors, especially arterial compliance, confirming its possible role as a marker of systemic vascular alterations. Several studies have shown that carotid intima-media thickness (cIMT) and carotid plaques (cP), assessed by ultrasonography, are documented markers of subclinical organ damage as well as expression of progressive atherosclerotic disease, and that they get worse with the progressive deterioration of renal function. The study was aimed to evaluate the relationship between RRI and severity of carotid atherosclerosis in hypertensive subjects with and without impaired renal function.

METHODS AND RESULTS

The study population, including 263 hypertensive patients (30-70 years), was split into 3 groups based on cIMT and presence of cP (cIMT ≤ 0.9 mm and no cP; cIMT > 0.9 mm and no cP; cP). All patients were also divided into 2 subgroups (normal renal function; CKD stage I-IV). A stepwise increase in RRI corresponding to the groups of progressive severity of carotid atherosclerosis was observed (respectively 0.61 ± 0.07, 0.65 ± 0.06, 0.68 ± 0.06; p < 0.001). A strong positive correlation was observed between RRI and cIMT in the whole population (r = 0.43; p < 0.001) and in the subgroups with (r = 0.42; p < 0.001) and without (r = 0.39; p < 0.001) CKD. These associations remained statistically significant even after adjustment for various confounding factors.

CONCLUSION

Showing a close association between RRI and severity of carotid atherosclerosis, our results strengthen the concept that RRI is a marker of systemic vascular changes.

Evaluation of the potential airborne release of carbon nanofibers during the preparation, grinding, and cutting of epoxy-based nanocomposite material

The National Institute for Occupational Safety and Health conducted an initial, task-based comparative assessment to determine the potential for release of carbon nanofibers (CNFs) during dry material handling, wet cutting, grinding, and sanding (by machine and hand) of plastic composite material containing CNFs. Using a combination of direct-reading instruments and filter-based air sampling methods for airborne mass and transmission electron microscopy (TEM), concentrations were measured and characterized near sources of particle generation, in the breathing zone of the workers, and in the general work area. Tasks such as surface grinding of composite material and manually transferring dry CNFs produced substantial increases in particle number concentration (range = 20,000-490,000 1-cm(-3)). Concomitant increases in mass concentration were also associated with most tasks. Nearly 90% of all samples examined via TEM indicated that releases of CNFs do occur and that the potential for exposure exists. These findings also indicate that improperly designed, maintained, or installed engineering controls may not be completely effective in controlling releases. Unprotected skin exposure to CNFs was noted in two instances and indicated the need for educating workers on the need for personal protective equipment. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF file containing information on materials, evaluated processes, personal protective equipment, and existing ventilation/engineering controls.].

Field application of the Nanoparticle Emission Assessment Technique (NEAT): task-based air monitoring during the processing of engineered nanomaterials (ENM) at four facilities

In early 2006, the National Institute for Occupational Safety and Health created a field research team whose mission is to visit a variety of facilities engaged in the production, handling, or use of engineered nanomaterials (ENMs) and to conduct initial emission and exposure assessments to identify candidate sites for further study. To conduct the assessments, the team developed the Nanoparticle Emission Assessment Technique (NEAT), which has been used at numerous facilities to sample multiple engineered nanomaterials. Data collected at four facilities, which volunteered to serve as test sites, indicate that specific tasks can release ENMs to the workplace atmosphere and that traditional controls such as ventilation can be used to limit exposure. Metrics such as particle number concentration (adjusted for background), airborne mass concentration, and qualitative transmission electron microscopy were used to determine the presence, nature, and magnitude of emissions and whether engineered nanomaterials migrated to the workers' breathing zone. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a PDF file containing information on facilities, a description of processes/tasks, existing controls, and sampling strategy, and a PDF file containing TEM images according to facility and task.].

Nanoparticle Emission Assessment Technique (NEAT) for the identification and measurement of potential inhalation exposure to engineered nanomaterials--Part B: Results from 12 field studies

The National Institute for Occupational Safety and Health (NIOSH) conducted field studies at 12 sites using the Nanoparticle Emission Assessment Technique (NEAT) to characterize emissions during processes where engineered nanomaterials were produced or used. A description of the NEAT appears in Part A of this issue. Field studies were conducted in research and development laboratories, pilot plants, and manufacturing facilities handling carbon nanotubes (single-walled and multi-walled), carbon nanofibers, fullerenes, carbon nanopearls, metal oxides, electrospun nylon, and quantum dots. The results demonstrated that the NEAT was useful in evaluating emissions and that readily available engineering controls can be applied to minimize nanomaterial emissions.

Nanoparticle emission assessment technique (NEAT) for the identification and measurement of potential inhalation exposure to engineered nanomaterials--part A

There are currently no exposure limits specific to engineered nanomaterial nor any national or international consensus standards on measurement techniques for nanomaterials in the workplace. However, facilities engaged in the production and use of engineered nanomaterials have expressed an interest in learning whether the potential for worker exposure exists. To assist with answering this question, the National Institute for Occupational Safety and Health established a nanotechnology field research team whose primary goal was to visit facilities and evaluate the potential for release of nanomaterials and worker exposure. The team identified numerous techniques to measure airborne nanomaterials with respect to particle size, mass, surface area, number concentration, and composition. However, some of these techniques lack specificity and field portability and are difficult to use and expensive when applied to routine exposure assessment. This article describes the nanoparticle emission assessment technique (NEAT) that uses a combination of measurement techniques and instruments to assess potential inhalation exposures in facilities that handle or produce engineered nanomaterials. The NEAT utilizes portable direct-reading instrumentation supplemented by a pair of filter-based air samples (source-specific and personal breathing zone). The use of the filter-based samples are crucial for identification purposes because particle counters are generally insensitive to particle source or composition and make it difficult to differentiate between incidental and process-related nanomaterials using number concentration alone. Results from using the NEAT at 12 facilities are presented in the companion article (Part B) in this issue.

Clinical correlates of renal dysfunction in hypertensive patients without cardiovascular complications: the REDHY study

Our study was aimed to assess the clinical correlates of different degrees of renal dysfunction in a wide group of non-diabetic hypertensive patients, free from cardiovascular (CV) complications and known renal diseases, participating to the REDHY (REnal Dysfunction in HYpertension) study. A total of 1856 hypertensive subjects (mean age: 47+/-14 years), attending our hypertension centre, were evaluated. The glomerular filtration rate (GFR) was estimated by the simplified Modification of Diet in Renal Disease Study prediction equation. A 24-h urine sample was collected to determine albumin excretion rate (AER). Albuminuria was defined as an AER greater than 20 microg min(-1). We used the classification proposed by the US National Kidney Foundation's guidelines for chronic kidney disease (CKD) to define the stages of renal function impairment. In multiple logistic regression analysis, the probability of having stage 1 and stage 2 CKD was significantly higher in subjects with greater values of systolic blood pressure (SBP) and with larger waist circumference. SBP was also positively related to stage 3 CKD. Stage 3 and stages 4-5 CKD were inversely associated with waist circumference and directly associated with serum uric acid. Age was inversely related to stage 1 CKD and directly related to stage 3 CKD. The factors associated with milder forms of kidney dysfunction are, in part, different from those associated with more advanced stages of renal function impairment.

Relationships between metabolic syndrome and left ventricular mass in hypertensive patients: does sex matter?

Several studies documented an association between metabolic syndrome (MetS) and left ventricular (LV) hypertrophy. However, only in a few of these studies the impact of MetS on left ventricular mass (LVM) was separately analysed by gender, with conflicting results. The aim of our study was to verify, in a wide sample of essential hypertensive patients, the influence of gender, if any, on the relationship between MetS and LVM. We enrolled 475 non-diabetic subjects (mean age: 46 +/- 11 years), with mild-to-moderate essential hypertension, of whom 40% had MetS, defined on the basis of Adult Treatment Panel III (ATPIII) criteria. All the patients underwent a 24-h ambulatory blood pressure monitoring and an echocardiogram. LVM indexed for height (2.7) (LVMH (2.7)) was significantly (P < 0.001) higher in women with MetS (n=83) than in those without it (n=97; 54+/-17 vs 42+/-11 g m(-2.7)). An equally significant difference in LVMH (2.7) was documented also in male gender between the two groups with (n=105) and without MetS (n=190; 51+/-14 vs 43+/-11 g m(-2.7); P < 0.001). The relationship between MetS and LVMH (2.7) remained statistically significant (P < 0.001) in both sexes, in multiple regression analyses, even after adjustment for potential confounding factors. Our results seem to suggest that the relationship between MetS and LVM is not significantly affected by gender, being LVM increased in both hypertensive women and men with MetS.

Inverse relationship between ambulatory arterial stiffness index and glomerular filtration rate in arterial hypertension

BACKGROUND

Arterial stiffness and mild-to-moderate renal dysfunction are predictors of cardiovascular (CV) morbidity and mortality. Recently, the ambulatory arterial stiffness index (AASI) has been proposed as a surrogate index of arterial stiffness. It has been associated with an enhanced risk of stroke. The aim of our study was to assess the relationship between AASI and glomerular filtration rate (GFR) in a group of hypertensive patients with no CV complications.

METHODS

A total of 143 untreated hypertensive subjects (mean age: 44 +/- 12 years; men 57%), with serum creatinine <1.5 mg/dl, were enrolled. AASI was calculated as one minus the regression slope of diastolic on systolic blood pressure (BP) obtained by individual 24-h BP recordings. GFR was computed from the scintigraphic determination of the technetium-99m diethylenetriaminepentaacetic acid uptake within the kidneys, by the Gates' method.

RESULTS

Hypertensive patients with AASI above the median value (n = 71) had lower GFR than those with AASI below the median (n = 72) (98.3 +/- 31 vs. 122.4 +/- 32 ml/min/1.73 m(2); P < 0.001). This difference held even after adjustment for age and gender. The linear regression analysis disclosed a significant inverse correlation between GFR and AASI (r = -0.30; P < 0.001), that was replicated (beta = -0.19; P = 0.02) in a multiple regression model including, as independent variables (besides AASI), age, gender, high-density lipoprotein cholesterol, body mass index, 24-h pulse pressure (PP) and nocturnal reduction in BP.

CONCLUSIONS

AASI is inversely related to GFR in arterial hypertension. This may help to explain the increased CV risk associated with mild-to-moderate renal dysfunction.

Metabolic syndrome in subjects with white-coat hypertension: impact on left ventricular structure and function

Some reports have suggested that white-coat hypertension (WCH) is associated with some features of the metabolic syndrome (MetS). These metabolic disturbances, instead of WCH per se, may potentially explain the greater extent of end-organ damage sometimes observed in WCH subjects (WCHs) when compared to normotensive individuals (NTs). The aim of the present cross-sectional study was to compare left ventricular (LV) structure and function in three groups of subjects: WCHs with MetS, WCHs without MetS and NTs. A total of 145 WCHs, 35% of whom had MetS, were enrolled. As controls, 35 NTs were also studied. In all subjects, routine blood chemistry, echocardiographic examination and 24-h ambulatory blood pressure monitoring were performed. When compared with WCHs without MetS, those with MetS showed higher LV mass indexed by height elevated by a power of 2.7 (LVMH(2.7)) (49.6+/-14.8 vs 38.9+/-9.8 g/m(2.7); P<0.0001). The same parameter was greater in WCHs without MetS than in NTs (32+/-8 g/m(2.7); P=0.004). Moreover, the E-wave deceleration time was longer in WCHs with MetS than in those without it (236.2+/-66.4 vs 200.5+/-30.8 ms; P<0.0001). The relationship of MetS with LVMH(2.7) was confirmed in multivariate regression models. Our results seem to suggest that MetS may have a deleterious influence on LV structure and function in WCH. However, WCH, being associated with an increased LV mass, also in subjects without MetS, may not be considered as an innocuous phenomenon.

Remarkable alkali cation template effect in 1,5-bridged calix[8]arenes

Treatment of 1,5-bridged calix[8]arenes 2-4 with alkali metal carbonates produces salts in which an included cation acts as a conformational template. This induces the folding of calix[8]arene skeleton in a conformation in which the triads of contiguous OH-bearing rings adopt a 3/4-cone conformation with all hydroxyls converging toward the same center. The template effect requires the presence of short bridges (ethylene, tetramethylene, diethylene glycol) and became stronger by increasing the cation dimension up to that of Cs(+).

An unusual nitrogenous terphenyl derivative from fruiting bodies of the basidiomycete Sarcodon leucopus

A new nitrogenous metabolite with a p-terphenyl core, sarcodonin (3), has been isolated from fruiting bodies of the basidiomycete Sarcodon leucopus. The structure of 3 was determined through a careful study of its peracetate 4, by use of an array of spectroscopic techniques (including (15)N NMR, gradient-enhanced, and reverse-detected 2D NMR experiments) and chemical degradation. ROESY data and molecular mechanics (MM+) calculations led to assignment of the absolute configuration of 4. Compound 3 exhibited moderate cytotoxicity against KB and P-388 tumor cell cultures.

Crenuladial, an antimicrobial diterpenoid from the brown alga Dilophus ligulatus

From the brown alga Dilophus ligulatus a new secondary metabolite with antimicrobial activity, crenuladial 4, has been isolated and its structure determined.

Previously unreported p-terphenyl derivatives with antibiotic properties from the fruiting bodies of Sarcodonleucopus (Basidiomycetes). A two-dimensional nuclear magnetic resonance study

Two previously unreported antibiotic metabolites, 2′,3′,4″-triacetoxy-3,4,5′,6′-tetrahydroxy-p-terphenyl (10) and 2′,3′-diacetoxy-3,4,5′,6′,4″-pentahydroxy-p-terphenyl (11), have been isolated from the basidiomycete Sarcodonleucopus. Their structures have been determined by chemical transformations and spectral analysis, including heteronuclear two-dimensional nuclear magnetic resonance methods.

Epidemiology of resistance to netilmicin and other aminoglycosides

The authors carried out a study to evaluate the epidemiology and resistance of netilmicin, gentamicin, tobramycin and amikacin during the 1984-1985 period. Clinical specimens of different origin, drawn both from hospitalized and outpatients were used in the study. The strains were tested for their sensitivity to aminoglycosides. In particular the degree of resistance in both fermentative and non-fermentative gram-negative strains was determined. As previously pointed out in other works, netilmicin showed good antimicrobial activity in respect to other aminoglycosides.

Susceptibility of some Staphylococcus species to aminoglycosides

The Staphylococcal strains, identified by "The Simplified Lyogroups System" were tested for their susceptibility to methicillin and some aminoglycosides. The results, besides showing a higher ratio of susceptibility against aminoglycosides in methicillin-susceptible (MS) strains, show a different trend within each lyogroup. A total of 1616 wild Staphylococcus strains were isolated in microbiological units in Catania, Messina, Rome and Genoa. The results show a high susceptibility to aminoglycosides, both in MS and methicillin-resistant (MR) groups but with different trends among lyogroups.

Identification, clinical distribution, and susceptibility to methicillin and 18 additional antibiotics of clinical Staphylococcus isolates: nationwide investigation in Italy

A multicentric study of clinical Staphylococcus isolates was performed by seven operative units working in different areas of Italy. Over a 6-month period, a total of 3,226 staphylococci, isolated from in- and outpatients, were identified and tested for antimicrobial susceptibility by a protocol agreed upon by all units. On the basis of their bacteriolytic-activity patterns and other conventional tests, the isolates were identified by lyogroups , which closely correlate with human Staphylococcus species. Lyogroup I (Staphylococcus aureus) and lyogroup III (Staphylococcus capitis) were the most and the least frequently isolated staphylococci, respectively. Significant differences depending on strain origin from in- or outpatients were only observed with lyogroup IV (i.e., novobiocin- resistant staphylococci), whose isolation from outpatients was three times greater than from inpatients. Lyogroup I was predominant among isolates from most clinical sources. Lyogroup IV predominated in strains isolated from the urinary tract; lyogroup V (Staphylococcus epidermidis) predominated in strains from blood, cerebrospinal fluid, and indwelling artificial devices; and lyogroup VI ( Staphylococcus hominis, Staphylococcus haemolyticus, and Staphylococcus warneri ) predominated in strains from bile and the male genital tract. The incidence of methicillin resistance within the different lyogroups varied from unit to unit, suggesting epidemiological differences among different hospitals and different geographical areas. On the whole, methicillin resistance was more frequent in coagulase-negative staphylococci than in S. aureus and ranged from 19% for lyogroups I and III to 30% for lyogroup II (Staphylococcus simulans). Laboratory testing with 18 additional antibiotics suggested the occurrence of some specific differences in susceptibility among the different lyogroups . The rate of organisms resistant to the various antibiotics was greater among methicillin-resistant than among methicillin -susceptible staphylococci; particularly marked differences occurred with cephalosporins, rifampin, gentamicin, and tobramycin. The results suggested an increasing spread in Italy, during the last few years, of staphylococcal resistance to methicillin and to many other antibiotics. Some questions about the actual reliability of laboratory tests for the determination of staphylococcal susceptibility to methicillin and other beta-lactam antibiotics were raised by parallel test performances in which both unsupplemented and 5% NaCl-supplemented Mueller-Hinton agars were used. The presence of NaCl heightened, on the whole, the number of resistant strains detected; however, a few isolates resistant in the unsupplemented medium and susceptible in the salt-supplemented medium were also encountered. This was true not only for methicillin but also for all other beta-lactam antibiotics tested except cefamandole. With cefamandole, the presence of 5% NaCl reduced the number of resistant strains detected.

[Incidence and antibiotic resistance of various species of staphylococci in a hospital environment in eastern Sicily]

In this work we carry out an epidemiologic investigation of the incidence of Staphylococci in some hospitals of east Sicily, in relation with hospitalized patients. The tests were performed every ten days for a period of four months, by using Fisher technique. The strains were isolated from clinical specimens from hospitalized patients, and after identification, we made antibiotics-resistance essays. The results show a correlation between Staphylococcus strains isolated from patients and that of environmental origin, also for the antibiotics resistance spectrum.

[Evaluation of a new system for the simultaneous identification and antibiotic sensitivity testing of gram-negative bacilli by automation]

ABAC- IDENTIBIOGRAMMA II is a new system allowing the carry out of antimicrobial susceptibility testing on various bacterial groups and also the fully automatic simultaneous susceptibility testing and identification of Gram-negative bacilli (urinary and not). Particularly most species of Enterobacteriaceae and Aeromonas hydrophila, Acinetobacter sp., Pseudomonas sp. can be identified. This system has two important characteristics, due to a computerized program: that is the possibility of using sensitivity data as complement of the biochemical assays to obtain identification and the directions for use transmitted through the display. The validity of system and the reliability of its results have been verified.

[Choice of criteria in the revision of the ABAC system for the determination of sensitivity to antibiotics]

The limitation of the ABAC system for the automated antibiotic sensitivity test is the fixed number of antibiotics to be assayed. This limit is partially overcome by the up-dating of ABAC disposables necessary both for bacterial infectious pathology (considerably various and dinamic) and bacterial resistance to antibiotics. Accordingly, research is constantly producing new antibiotics particularly in the beta-lactamine and aminoglycoside fields. In these groups new antibiotics must be found to substitute the old ones in the ABAC disposables, in particular in relation to Gram-negative bacteria (urinary or not). The preparation of a rotor for experimental use containing new antibiotics not present on the market is proposed to evaluate their validity through a rapid and standardized method.

[Evaluation of a new system for simultaneous identification and antibiograms of enterobacteria from urine]

A new rotor for the ABAC system has been investigated that allows the main enterobacteria of urinary source to be identified (this is performed manually) and simultaneously the relative antibiogram (this is automatically carried out). The precision of this identification has been shown using control strains previously identified by three miniaturized kits: API 20 E, MICRO-ID and ENTEROPLATE. The accuracy of the ten identification tests present in the new "Identibiogramma" rotor has also been shown. Finally, the correspondence has been shown between the antibiogram performed with the automatized method and that with the KirbyBauer method. The data obtained evidence the validity of the new rotor and of the ABAC system.