Moraxella catarrhalis AcrAB-OprM efflux pump contributes to antimicrobial resistance and is enhanced during cold shock response

Moraxella catarrhalis is a common pathogen of the human respiratory tract. Multidrug efflux pumps play a major role in antibiotic resistance and virulence in many Gram-negative organisms. In the present study, the role of the AcrAB-OprM efflux pump in antibiotic resistance was investigated by constructing mutants that lack the acrA, acrB, and oprM genes in M. catarrhalis strain O35E. We observed a moderate (1.5-fold) decrease in the MICs of amoxicillin and cefotaxime and a marked (4.7-fold) decrease in the MICs of clarithromycin for acrA, acrB, and oprM mutants in comparison with the wild-type O35E strain. Exposure of the M. catarrhalis strains O35E and 300 to amoxicillin triggered an increased transcription of all AcrAB-OprM pump genes, and exposure of strains O35E, 300, and 415 to clarithromycin enhanced the expression of acrA and oprM mRNA. Inactivation of the AcrAB-OprM efflux pump genes demonstrated a decreased ability to invade epithelial cells compared to the parental strain, suggesting that acrA, acrB, and oprM are required for efficient invasion of human pharyngeal epithelial cells. Cold shock increases the expression of AcrAB-OprM efflux pump genes in all three M. catarrhalis strains tested. Increased expression of AcrAB-OprM pump genes after cold shock leads to a lower accumulation of Hoechst 33342 (H33342), a substrate of AcrAB-OprM efflux pumps, indicating that cold shock results in increased efflux activity. In conclusion, the AcrAB-OprM efflux pump appears to play a role in the antibiotic resistance and virulence of M. catarrhalis and is involved in the cold shock response.

Pelvic Fractures in Children Results from the German Pelvic Trauma Registry: A Cohort Study.

As pelvic fractures in children and adolescents are very rare, the surgical management is not well delineated nor are the postoperative complications. The aim of this study using the prospective data from German Pelvic Trauma Registry study was to evaluate the various treatment approaches compared to adults and delineated the differences in postoperative complications after pelvic injuries.Using the prospective pelvic trauma registry established by the German Society of Traumatology and the German Section of the Arbeitsgemeinschaft für Osteosynthesefragen (AO), International in 1991, patients with pelvic fractures over a 12-year time frame submitted by any 1 of the 23 member level I trauma centers were reviewed.We identified a total of 13,525 patients including pelvic fractures in 13,317 adults and 208 children aged ≤14 years and compared these 2 groups. The 2 groups' Injury Severitiy Score (ISS) did not differ statistically. Lethality in the pediatric group was 6.3%, not statistically different from the adults' 4.6%. In all, 18.3% of the pediatric pelvic fractures were treated surgically as compared to 22.7% in the adult group. No child suffered any thrombosis/embolism, acute respiratory distress syndrome (ARDS), multiorgan failure (MOF), or neurologic deficit, nor was any septic MOF detected. The differences between adults and children were statistically significant in that the children suffered less frequently from thrombosis/embolism (P = 0.041) and ARDS and MOF (P = 0.006).This prospective multicenter study addressing patients with pelvic fractures reveals that the risk for a thrombosis/embolism, ARDS, and MOF is significant lower in pediatric patients than in adults. No statistical differences could be found in the ratios of operative therapy of the pelvic fractures in children compared to adults.

Does exhaled nitric oxide predict asthma exacerbation in children?

Asthma is a chronic complex disorder of the respiratory tract that affects millions of people globally, a large percentage of which are children. Triggered by a host of factors such as allergens and changes in temperature, the pathophysiologic and clinical indices vary among patients and have contributed to difficulties in overall management of asthma. Shortly after exhaled nitric oxide (eNO) was discovered in higher concentrations in asthma patients, it was shown to be superior to other markers such as PEFR, FEV1 and sputum eosinophils in screening asthma patients. Studies have also noted promising results regarding the use of eNO to predict asthma exacerbation in adults while in children, asthma symptoms have been observed to be good predictors of asthma exacerbation. Currently however, the potential of eNO as a predictor of asthma exacerbation in children is yet to be examined. The objective of this study was to assess eNO potential to predict asthma exacerbation in children by examining the relationship between eNO and changes in pulmonary function, asthma symptoms and rescue medication use.^ The primary study "Air Toxics and Asthma in Children" (ATAC), recruited children aged 9 to 14 years with labile persistent asthma diagnosed at least one year earlier. The data obtained from 30 study participants, included exhaled nitric oxide concentration, PEFR, FEV1, asthma symptoms and frequency of emergency medication use.^ Descriptive statistics, Pearson's and Spearman's correlation tests were followed by a simple linear regression in which eNO was the independent (predictor) variable while FEV1, PEFR, asthma symptoms and frequency of emergency medication use were the dependent (outcome) variables.^ Results showed that eNO was associated with percent change in FEV1, day time wheeze, night time shortness of breath, but correlated only weakly with PEFR, amplitude percent of mean PEFR, FEV1, percent change in FEV1 and asthma symptoms.^ Further research is imperative to better define the role of eNO and understand intrinsic pathologic mechanisms towards asthma management in children.^

The burden of parainfluenza virus infection in patients with hematological malignancy and hematopoietic stem cell transplant (HSCT) recipients in the absence of active immunization and approved therapy: The role of infection control

Background. Community respiratory viruses, mainly RSV and influenza, are significant causes of morbidity and mortality in patients with leukemia and HSCT recipients. The data on impact of PIV infections in these patients is lacking. Methods. We reviewed the records of patients with leukemia and HSCT recipients who developed PIV infection from Oct'02–Nov'07 to determine the outcome of such infections. Results. We identified 200 patients with PIV infections including 80(40%) patients with leukemia and 120 (60%) recipients of HSCT. Median age was 55 y (17-84 y). As compared to HSCT recipients, patients with leukemia had higher APACHE II score (14 vs. 10, p<0.0001); were more likely to have ANC<500 (48% vs. 10%, p<0.0001) and ALC<200 (45% vs. 23.5%, p=0.02). PIV type III was the commonest isolate (172/200, 86%). Most patients 141/200 (70%) had upper respiratory infection (URI), and 59/200 (30%) had pneumonia at presentation. Patients in leukemia group were more likely to require hospitalization due to PIV infection (77% vs. 36% p=0.0001) and were more likely to progress to pneumonia (61% vs. 39%, p=0.002). Fifty five patients received aerosolized ribavirin and/or IVIG. There were no significant differences in the duration of symptoms, length of hospitalization, progression to pneumonia or mortality between the treated verses untreated group. The clinical outcome was unknown in 13 (6%) patients. Complete resolution of symptoms was noted in 91% (171/187) patients and 9% (16/187) patients died. Mortality rate was 17% (16/95) among patients who had PIV pneumonia, with no significant difference between leukemia and HSCT group (16% vs. 17%). The cause of death was acute respiratory failure and/or multi-organ failure in (13, 81%) patients. Conclusions. Patients with leukemia and HSCT could be at high risk for serious PIV infections including PIV pneumonia. Treatment with aerosolized ribavirin and/or IVIG may not have significant effect on the outcome of PIV infection.^

Scanned Ion Beam Therapy for Thoracic Tumors

Although frequently cured of Hodgkin lymphoma, adolescents and young adults can develop radiation induced second cancers. These patients could potentially benefit from scanned ion radiotherapy yet likely would require motion mitigation strategies. In theory, four-dimensional (4D) optimization of ion beam fields for individual motion states of respiration can enable superior sparing of healthy tissue near moving targets, compared to other motion mitigation strategies. Furthermore, carbon-ion therapy can sometimes provide greater relative biological effectiveness (RBE) for cell sterilization in a target but nearly equivalent RBE in tissue upstream of the target, compared to proton therapy. Thus, we expected that for some patients with Hodgkin lymphoma, carbon-ion therapy would reduce the predicted risk of second cancer incidence in the breast compared with proton therapy. The purpose of this work was to determine whether 4D-optimized carbon-ion therapy would significantly reduce the predicted risk of radiation induced second cancers in the breast for female Hodgkin lymphoma patients while preserving tumor control compared with proton therapy. To achieve our goals, we first investigated whether 4D-optimized carbon beam tracking could reduce dose to volumes outside a moving target compared with 3D-optimized carbon beam tracking while preserving target dose coverage. To understand the reliability of scanned carbon beam tracking, we studied the robustness of dose distributions in thoracic targets to uncertainties in patient motion. Finally, we investigated whether using carbon-ion therapy instead of proton therapy would significantly reduce the predicted risk of second cancer in the breast for a sample of Hodgkin lymphoma patients. We found that 4D-optimized ion beam tracking therapy can reduce the maximum dose to critical structures near a moving target by as much as 53%, compared to 3D-optimized ion beam tracking therapy. We validated these findings experimentally using a scanned carbon ion synchrotron and a motion phantom. We found scanned carbon beam tracking to be sensitive to a number of motion uncertainties, most notably phase delays in tracking, systematic spatial errors, and interfractional motion changes. Our findings indicate that a lower risk of second cancer in the breast might be expected for some Hodgkin lymphoma patients using carbon-ion therapy instead of proton therapy. For our reference scenario, we found the ratio of risk to be 0.77 ± 0.35 for radiogenic breast cancer after carbon-ion therapy versus proton therapy. Our findings were dependent on the RBE values for tumor induction and the radiosensitivity of breast tissue, as well as the physical dose distribution.

Lesiones estomatológicas del VPH genotipo 16 en la pre-adolescencia

El virus del Papiloma Humano infecta de manera selectiva al epitelio de la piel y las mucosas. Cuando se producen las infecciones, éstas pueden ser asintomáticas, provocando lesiones de tipos verrugosos o asociados a diversas neoplasias, benignos o malignos del tracto respiratorio superior y la cavidad bucal principalmente. Se presenta el caso de una niña con lesiones orales producidas por el VPH. Las lesiones se manifiestan clínicamente: elevadas, pediculadas y de superficie papilar; otras son planas y difusas sobre una base sésil.

Characteristics of virus-specific CD8+ T cells in the liver during the control and resolution phases of influenza pneumonia

Dissection of the primary and secondary response to an influenza A virus established that the liver contains a substantial population of CD8+ T cells specific for the immunodominant epitope formed by H-2Db and the influenza virus nucleoprotein peptide fragment NP366–374 (DbNP366). The numbers of CD8+ DbNP366+ cells in the liver reflected the magnitude of the inflammatory process in the pneumonic lung, though replication of this influenza virus is limited to the respiratory tract. Analysis of surface phenotypes indicated that the liver CD8+ DbNP366+ cells tended to be more “activated” than the set recovered from lymphoid tissue but generally less so than those from the lung. The distinguishing characteristic of the lymphocytes from the liver was that the prevalence of the CD8+ DbNP366+ set was always much higher than the percentage of CD8+ T cells that could be induced to synthesize interferon γ after short-term, in vitro stimulation with the NP366–374 peptide, whereas these values were generally comparable for virus-specific CD8+ T cells recovered from other tissue sites. Also, the numbers of apoptotic CD8+ T cells were higher in the liver. The results overall are consistent with the idea that antigen-specific CD8+ T cells are destroyed in the liver during the control and resolution phases of this viral infection, though this destruction is not necessarily an immediate process.

Engineering the largest RNA virus genome as an infectious bacterial artificial chromosome

The construction of cDNA clones encoding large-size RNA molecules of biological interest, like coronavirus genomes, which are among the largest mature RNA molecules known to biology, has been hampered by the instability of those cDNAs in bacteria. Herein, we show that the application of two strategies, cloning of the cDNAs into a bacterial artificial chromosome and nuclear expression of RNAs that are typically produced within the cytoplasm, is useful for the engineering of large RNA molecules. A cDNA encoding an infectious coronavirus RNA genome has been cloned as a bacterial artificial chromosome. The rescued coronavirus conserved all of the genetic markers introduced throughout the sequence and showed a standard mRNA pattern and the antigenic characteristics expected for the synthetic virus. The cDNA was transcribed within the nucleus, and the RNA translocated to the cytoplasm. Interestingly, the recovered virus had essentially the same sequence as the original one, and no splicing was observed. The cDNA was derived from an attenuated isolate that replicates exclusively in the respiratory tract of swine. During the engineering of the infectious cDNA, the spike gene of the virus was replaced by the spike gene of an enteric isolate. The synthetic virus replicated abundantly in the enteric tract and was fully virulent, demonstrating that the tropism and virulence of the recovered coronavirus can be modified. This demonstration opens up the possibility of employing this infectious cDNA as a vector for vaccine development in human, porcine, canine, and feline species susceptible to group 1 coronaviruses.

Lipophosphoglycan from Leishmania suppresses agonist-induced interleukin 1β gene expression in human monocytes via a unique promoter sequence

Leishmania are parasites that survive within macrophages by mechanism(s) not entirely known. Depression of cellular immunity and diminished production of interleukin 1β (IL-1β) and tumor necrosis factor α are potential ways by which the parasite survives within macrophages. We examined the mechanism(s) by which lipophosphoglycan (LPG), a major glycolipid of Leishmania, perturbs cytokine gene expression. LPG treatment of THP-1 monocytes suppressed endotoxin induction of IL-1β steady-state mRNA by greater than 90%, while having no effect on the expression of a control gene. The addition of LPG 2 h before or 2 h after endotoxin challenge significantly suppressed steady-state IL-1β mRNA by 90% and 70%, respectively. LPG also inhibited tumor necrosis factor α and Staphylococcus induction of IL-1β gene expression. The inhibitory effect of LPG is agonist-specific because LPG did not suppress the induction of IL-1β mRNA by phorbol 12-myristate 13-acetate. A unique DNA sequence located within the −310 to −57 nucleotide region of the IL-1β promoter was found to mediate LPG’s inhibitory activity. The requirement for the −310 to −57 promoter gene sequence for LPG’s effect is demonstrated by the abrogation of LPG’s inhibitory activity by truncation or deletion of the −310 to −57 promoter gene sequence. Furthermore, the minimal IL-1β promoter (positions −310 to +15) mediated LPG’s inhibitory activity with dose and kinetic profiles that were similar to LPG’s suppression of steady-state IL-1β mRNA. These findings delineated a promoter gene sequence that responds to LPG to act as a “gene silencer,” a function, to our knowledge, not previously described. LPG’s inhibitory activity for several mediators of inflammation and the persistence of significant inhibitory activity 2 h after endotoxin challenge suggest that LPG has therapeutic potential and may be exploited for therapy of sepsis, acute respiratory distress syndrome, and autoimmune diseases.

Effectiveness of antibiotic prophylaxis in critically ill adult patients: systematic review of randomised controlled trials

Objective: To determine whether antibiotic prophylaxis reduces respiratory tract infections and overall mortality in unselected critically ill adult patients.

Measuring the diaspora for virus-specific CD8+ T cells

The CD8+ T cell diaspora has been analyzed after secondary challenge with an influenza A virus that replicates only in the respiratory tract. Numbers of DbNP366- and DbPA224-specific CD8+ T cells were measured by tetramer staining at the end of the recall response, then followed sequentially in the lung, lymph nodes, spleen, blood, and other organs. The extent of clonal expansion did not reflect the sizes of the preexisting memory T cell pools. Although the high-frequency CD8+ tetramer+ populations in the pneumonic lung and mediastinal lymph nodes fell rapidly from peak values, the “whole mouse” virus-specific CD8+ T cell counts decreased only 2-fold over the 4 weeks after infection, then subsided at a fairly steady rate to reach a plateau at about 2 months. The largest numbers were found throughout in the spleen, then the bone marrow. The CD8+DbNP366+ and CD8+DbPA224+ sets remained significantly enlarged for at least 4 months, declining at equivalent rates while retaining the nucleoprotein > acid polymerase immunodominance hierarchy characteristic of the earlier antigen-driven phase. Lowest levels of the CD69 “activation marker” were detected consistently on virus-specific CD8+ T cells in the blood, then the spleen. Those in the bone marrow and liver were intermediate, and CD69hi T cells were very prominent in the regional lymph nodes and the nasal-associated lymphoid tissue. Any population of “resting” CD8+ memory T cells is thus phenotypically heterogeneous, widely dispersed, and subject to broad homeostatic and local environmental effects irrespective of epitope specificity or magnitude.

Effectiveness of influenza vaccination programme in preventing hospital admissions, Valencia, 2014/15 early results

Preliminary results for the 2014/15 season indicate low to null effect of vaccination against influenza A(H3N2)-related disease. As of week 5 2015, there have been 1,136 hospital admissions, 210 were due to influenza and 98% of subtype A strains were H3. Adjusted influenza vaccine effectiveness was 33% (range: 6–53%) overall and 40% (range: 13% to 59%) in those 65 years and older. Vaccination reduced by 44% (28–68%) the probability of admission with influenza.

Doença de Addison no adulto

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Genetic variability and limited clonality of Mycoplasma hyorhinis in pig herds

Mycoplasma hyorhinis is a common inhabitant of the upper respiratory tract and tonsils of pigs. Its role as a possible pathogen remains controversial. In order to gain more insight into the epidemiology and population structure of M. hyorhinis we genetically characterized 60 isolates by multi locus sequence typing (MLST). The M. hyorhinis strains originated from Swiss and German pig herds with knowledge on the clinical background. The MLST scheme of Tocqueville et al. (J. Clin. Microbiol. 2014) was optimized, primers for the six MLST gene fragments were newly designed to allow amplification and sequencing with a single protocol. A total of 27 ST were observed with the 60 strains, 26 of those were previously unknown types. Generally identical genotypes were observed within a farm but they differed between farms. The identical genotype was also observed in three different Swiss farms. On the other Hand different genotypes within a farm were found with three German farms. The Swiss isolates formed a distinct cluster but otherwise there was no geographical nor a clinical association with specific Clusters observed. Data shows a high variability of M. hyorhinis comparable to what is observed for Mycoplasma hyopneumoniae. Similar to this pathogen the population structure of M. hyorhinis also shows some limited clonality with predominant genotypes within an animal and a single farm but different ones between farms. The comparable population structure of M. hyopneumoniae and M. hyorhinis could indicate a similar evolution of the two species in the common pig host.

Health effects of a wastewater treatment system /

Issued Oct. 1978.