Cloning, nucleotide sequencing, and analysis of the AcrAB-TolC efflux pump of Enterobacter cloacae and determination of its involvement in antibiotic resistance in a clinical isolate

Enterobacter cloacae is an emerging clinical pathogen that may be responsible for nosocomial infections. Management of these infections is often difficult, owing to the high frequency of strains that are resistant to disinfectants and antimicrobial agents in the clinical setting. Multidrug efflux pumps, especially those belonging to the resistance-nodulation-division family, play a major role as a mechanism of antimicrobial resistance in gram-negative pathogens. In the present study, we cloned and sequenced the genes encoding an AcrAcB-TolC-like efflux pump from an E. cloacae clinical isolate (isolate EcDC64) showing a broad antibiotic resistance profile. Sequence analysis showed that the acrR, acrA, acrB, and tolC genes encode proteins that display 79.8%, 84%, 88%, and 82% amino acid identities with the respective homologues of Enterobacter aerogenes and are arranged in a similar pattern. Deletion of the acrA gene to yield an AcrA-deficient EcDC64 mutant (EcDeltaacrA) showed the involvement of AcrAB-TolC in multidrug resistance in E. cloacae. However, experiments with an efflux pump inhibitor suggested that additional efflux systems also play a role in antibiotic resistance. Investigation of several unrelated isolates of E. cloacae by PCR analysis revealed that the AcrAB system is apparently ubiquitous in this species.     

Regionalization in Neonatal Congenital Heart Surgery: The Impact of Distance on Outcome After Discharge

Studies have shown improved perioperative outcomes after neonatal heart surgery at centers with greater surgical volumes. The impact of increasing distance from such centers on outcome after discharge has not yet been reported. Chart review and cross-sectional survey were performed on children discharged or transferred after undergoing neonatal congenital heart surgery as neonates (<30 days of age) from January 2005 to June 2006. The association of distance from center with mortality and adverse events was analyzed by univariate and multivariate regression and stratified by the Risk Adjustment for Congenital Heart Surgery-1 for complexity. Among 217 patients, those living further from the surgical center were smaller and older at surgery and more likely to be RACHS-1 class 6. Overall mortality was 8% (16 of 202) and was not associated with distance. Surveys were completed by 109 (54%) families with mean follow-up of 24 (±3) months. Unplanned admissions after discharge and unplanned interventions occurred in 45% and 40% of patients, respectively. After adjusting for case complexity, living 90–300 min away from the surgical center was associated with fewer unplanned admissions compared with those living <90 min away. After neonatal cardiac surgery, adverse events were common. Distance from the surgical center was not associated with mortality, but it was associated with morbidity in a nonlinear fashion. This relation, its mediators, and its possible impact on mortality and later outcomes warrant further study to aid in planning appropriate patient follow-up.     

Component-resolved immunologic modifications, efficacy, and tolerance of latex sublingual immunotherapy in children

BackgroundAs the frequency of natural rubber latex (NRL) allergy has increased, attempts have been made to diminish exposure in high-risk patients. Despite some good results, complete NRL avoidance was not possible, so latex immunotherapy was developed.ObjectiveTo examine variations in immunologic parameters, clinical efficacy, and safety of NRL sublingual immunotherapy (SLIT).MethodsThis prospective, observational, open, case-control study included 23 patients (18 patients receiving NRL SLIT and 5 controls). Skin prick, conjunctival provocation, and in-use tests with NRL, specific IgE and specific IgG4 to NRL, specific IgE to recombinant NRL allergens, and basophil activation test (BAT) with whole latex, natural, and recombinant allergens were performed before immunotherapy (T0) and at 6 (T1) and 12 months (T2) of treatment.ResultsPatients were sensitized to Hev b 5, Hev b 6.01, and Hev b 6.02 proteins, optimal for SLIT. Changes in specific IgE were not significant. Increases in specific IgG4 between T1 and T2 were larger in the active group. BAT determinations showed significant decreases in recombinant Hev b 6.01 and natural Hev b 6.02 in the active group at T1 but not at T2. Both groups had new sensitizations at T1 but not at T2. The active group had significant increases in the response threshold in the in vivo tests at T1 and T2. Adverse effects were limited to local reactions.ConclusionNRL SLIT is effective and safe in children with latex allergy. Our results suggest that specific IgE determinations and BAT measurements to natural and recombinant latex allergens may allow obtaining an allergen-based diagnosis to help determine specific immunotherapy.     

Attachment representations and stress in mothers of very low birth weight preterm infants at two years of age

IntroductionThere is a consensus that prematurity could affect the risk of attachment impairment.Material and methodsWe studied 90 very low birth weights preterm children (<1500 g) with follow-ups at Cruces Hospital (Bizkaia) and 96 healthy children born at term with similar age and sociodemographic characteristics. Our objective is to assess maternal stress and link model in accordance to attachment representations of mothers on both groups by using R Interview for Maternal Representations.ResultsPreterm infants had a medium-to-severe degree of immaturity and biological risk: mean gestational age of 29.9 weeks and birth weight 1159.76 gr, with 57% staying in the ICU ≥ 1 week. Mothers of preterm infants reported higher levels of stress during their first year of life (61%) than controls (39%), but no significant differences were found in link model (attachment representations) between the two groups.Discussion and conclusionsThe results confirm that preterm birth has a great influence on maternal emotional responses, and indicate that stress responses in parents and alarm signs for attachment problems should be assessed as early as possible.     

硝苯吡啶对急进高原现场幼猪血流动力学及血气的影响

目的 :了解硝苯吡啶 (Nifedipine ,NF)对高原急性缺氧的治疗作用。方法 :利用右心导管法对急进高原现场急性缺氧幼猪应用NF前后的血流动力学及血气各时相点的变化情况进行观察。结果 :急进高原现场幼猪应用NF后肺动脉压 (PAP)及肺血管阻力 (PVR)显著下降 (各时相点分别为P <0 .0 5～ 0 .0 1 ) ,心输出量 (CO)及动脉血SaO2 、PaO2 显著升高 (P <0 .0 5～ 0 .0 0 1 ) ;而心率 (HR)、肺动脉楔压 (PAWP)、平均体动脉压 (mSAP)、PH、HCO3- 、PaCO2 变化无统计学意义。结论 :NF可明显降低急进高原现场幼猪的肺动脉压 (PAP) ,提高CO和动脉血SaO2 、PaO2 ,有利于急性缺氧的治疗。