Clonal dissemination of multilocus sequence type ST15 KPC‐2‐producing Klebsiella pneumoniae in Bulgaria

A total of 36 consecutive clinical and two fecal‐screening carbapenem‐resistant Klebsiella pneumoniae isolates from two Bulgarian university hospitals (Varna and Pleven) were investigated. Susceptibility testing, conjugation experiments, and plasmid replicon typing were carried out. Beta‐lactamases were characterized by isoelectric focusing, PCR, and sequencing. Clonal relatedness was investigated by RAPD and multilocus sequence typing (MLST). Most of the isolates demonstrated multidrug resistance profile. Amikacin and tigecycline retained good activity with susceptibility rates of 95 and 87%, respectively. The resistance rate to colistin was 63%. Six RAPD‐ and MLST‐types were identified: the dominating MLST‐type was ST15 (27 isolates), followed by ST76 (six isolates), and ST1350 (two isolates). ST101, ST258, and ST151 were detected once. All except one of the K. pneumoniae produced KPC‐2, mostly in combination with CTX‐M‐15, while for one isolate (ST101) the enzymes OXA‐48 and CTX‐M‐14 were found. All KPC‐2‐producing transconjugants revealed the presence of IncFII plasmid. The OXA‐48‐ and CTX‐M‐14‐producing isolate showed the presence of L/M replicon type. The dissemination of KPC‐2‐producing K.pneumoniae in Bulgaria is mainly due to the sustained spread of successful ST15 clone and to a lesser extent of ST76 clone. This is the first report of OXA‐48 producing ST101 K. pneumoniae in Bulgaria.     

Influence of volatile organic compounds emitted by Pseudomonas and Serratia strains on Agrobacterium tumefaciens biofilms

The ability to form biofilms plays an important role in bacteria‐host interactions, including plant pathogenicity. In this work, we investigated the action of volatile organic compounds (VOCs) produced by rhizospheric strains of Pseudomonas chlororaphis 449, Pseudomonas fluorescens B‐4117, Serratia plymuthica IC1270, as well as Serratia proteamaculans strain 94, isolated from spoiled meat, on biofilms formation by three strains of Agrobacterium tumefaciens which are causative agents of crown‐gall disease in a wide range of plants. In dual culture assays, the pool of volatiles emitted by the tested Pseudomonas and Serratia strains suppressed the formation of biofilms of A. tumefaciens strains grown on polycarbonate membrane filters and killed Agrobacterium cells in mature biofilms. The individual VOCs produced by the tested Pseudomonas strains, that is, ketones (2‐nonanone, 2‐heptanone, 2‐undecanone), and dimethyl disulfide (DMDS) produced by Serratia strains, were shown to kill A. tumefaciens cells in mature biofilms and suppress their formation. The data obtained in this study suggest an additional potential of some ketones and DMDS as protectors of plants against A. tumefaciens strains, whose virulence is associated with the formation of biofilms on the infected plants.     

Characteristics of negative pressure inspiration effect on the cardiorespiratory system of humans in the conditions of 5-day dry immersion

Changes in external respiration and central hemodynamics induced by negative (relative to atmospheric) inspiration pressure were studied in supine subjects before and on day-4 of a dry immersion (DI) experiment. Changes in the cardiorespiratory system as a result of negative inspiration pressure included rise of the amplitude of breathing motions and reduction of their frequency, and distinct breathing-related HR fluctuations. Combination of immersion and altered pressure in the mask caused breathing-related variations of systolic pressure and plethysmogram signal, and improved arterial blood oxygenation. These results can be useful for developing pressure-gradient methods of counteracting the adverse effects of blood redistribution toward the cranial-end.     

Effect of alpha-tocopherol on activity of free-radical processes and erythron in a rat fetus with chronic nitrite intoxication

The condition of erythron and the activity of free-radical processes in fetuses of rats with chronic nitrite intoxication were studied and the effects of alpha-tocopherol injection (150 mg/kg, i.m.) were evaluated. A long-term introduction of nitrites (0.2% solution of sodium nitrite, p.o.) led to an increase in the erythrocyte count, hemoglobin content, and free radical concentration and a decrease in the antioxidant potential. The injection of alpha-tocopherol on the background of nitrite intoxication made these negative changes less expressed than in the case of separate administration of sodium nitrite. The amount of free radicals in the blood serum of fetuses of rats treated with alpha-tocopherol decreased, while the activity of the antioxidant system increased.     

A literature review of cost-benefit analyses for the treatment of alcohol dependence

The purpose of this study was to conduct a literature review of cost-benefit studies on pharmacotherapy and psychotherapy treatments of alcohol dependence (AD). A literature search was performed in multiple electronic bibliographic databases. The search identified seven psychotherapy studies from the USA and two pharmacotherapy studies from Europe. In the psychotherapy studies, major benefits are typically seen within the first six months of treatment. The benefit-cost ratio ranged from 1.89 to 39.0. Treatment with acamprosate was found to accrue a net benefit of 21,301 BEF (528 ? per patient over a 24-month period in Belgium and lifetime benefit for each patient in Spain was estimated to be Pta. 3,914,680 (23,528 ?. To date, only a few studies exist that have examined the cost-benefit of psychotherapy or pharmacotherapy treatment of AD. Most of the available treatment options for AD appear to produce marked economic benefits.     

Substantiating the blood concentrations of phenol and alkylphenols (o-, m-, and p-cresols) providing the acceptable risk to human health

The paper considers the current nontraditional approaches to revealing the causal effects and criteria for significance of an exposure-response relationship. The study has used the elements of methodology for assessing the risk and the techniques of environmental epidemiology to examine causal effects. A blood toxicant-response marker relationship was assessed and the quantitative characteristics of the association between the concentrations of the test compounds and the risk of noxious effects were ascertained. On the basis of exposure marker-response marker models, the authors revealed the priority types of functional changes and established the blood concentrations of phenol and m- and n-cresols at an acceptable risk level.     

Immediate and long-lasting effects of chronic stress in the prepubertal age on the startle reflex

The immediate and long-lasting effects of two models of chronic stress during the prepubertal period of life (21-32 days) on the acoustic startle response (ASR) were studied in outbred Wistar normotensives and rats with inherited stress-induced arterial hypertension (ISIAH) derived from them. Chronic variable stress (CVS) and repeated handling were used as chronic treatment. The obtained data showed a significantly attenuated ASR and a greater magnitude of prepulse inhibition (PPI) in juvenile and adult ISIAH compared to Wistar rats. The immediate effects of prolonged stress on the ASR were genotype-dependent. Young ISIAH rats exposed to both types of prepubertal stimulation had higher ASR than the age-matched controls. No significant stress-induced changes in the ASR were found in young Wistar rats. The long-lasting consequences of prolonged prepubertal stress were similar in the two strains and were determined by the specificity of stress stimulation: chronic handling had no effect on the ASR, while CVS enhanced it. The long-lasting effect of CVS experienced in prepubertal life appears to produce ASR changes similar to those seen in patients with posttraumatic stress disorder (PTSD). The magnitude of PPI increased from early age to adulthood and it was tolerant to environmental influences. The two rat strains did not differ in the rate of short-term habituation to repeated acoustic stimuli, which was unaffected by prepubertal stress. Evidence was obtained indicating that genetic and environmental background in childhood may contribute to the truncation of the startle response.