Expression of accessory genes in Salmonella requires the presence of the Gre factors.

Genomic studies with Salmonella enterica serovar Typhimurium reveal a crucial role of horizontal gene transfer (HGT) in the acquisition of accessory cellular functions involved in host-interaction. Many virulence genes are located in genomic islands, plasmids and prophages. GreA and GreB proteins, Gre factors, interact transiently with the RNA polymerase alleviating backtracked complexes during transcription elongation. The overall effect of Gre factors depletion in Salmonella expression profile was studied. Both proteins are functionally redundant since only when both Gre factors were depleted a major effect in gene expression was detected. Remarkably, the accessory gene pool is particularly sensitive to the lack of Gre factors, with 18.6% of accessory genes stimulated by the Gre factors versus 4.4% of core genome genes. Gre factors involvement is particularly relevant for the expression of genes located in genomic islands. Our data reveal that Gre factors are required for the expression of accessory genes.

ppGpp, the General Stress Response Alarmone, Is Required for the Expression of the α-Hemolysin Toxin in the Uropathogenic Escherichia coli Isolate, J96.

ppGpp is an intracellular sensor that, in response to different types of stress, coordinates the rearrangement of the gene expression pattern of bacteria to promote adaptation and survival to new environmental conditions. First described to modulate metabolic adaptive responses, ppGpp modulates the expression of genes belonging to very diverse functional categories. In Escherichia coli, ppGpp regulates the expression of cellular factors that are important during urinary tract infections. Here, we characterize the role of this alarmone in the regulation of the hlyCABDII operon of the UPEC isolate J96, encoding the toxin α-hemolysin that induces cytotoxicity during infection of bladder epithelial cells. ppGpp is required for the expression of the α-hemolysin encoded in hlyCABDII by stimulating its transcriptional expression. Prototrophy suppressor mutations in a ppGpp-deficient strain restore the α-hemolysin expression from this operon to wild-type levels, confirming the requirement of ppGpp for its expression. ppGpp stimulates hlyCABDII expression independently of RpoS, RfaH, Zur, and H-NS. The expression of hlyCABDII is promoted at 37 °C and at low osmolarity. ppGpp is required for the thermoregulation but not for the osmoregulation of the hlyCABDII operon. Studies in both commensal and UPEC isolates demonstrate that no UPEC specific factor is strictly required for the ppGpp-mediated regulation described. Our data further support the role of ppGpp participating in the coordinated regulation of the expression of bacterial factors required during infection.

Impact of dietary porcine blood by-products in meagre (Argyrosomus regius) physiology, evaluated by welfare biomarkers and the antibacterial properties of the skin mucus.

Tools are required for quick and easy preliminary evaluation of functional feeds efficiency on fisheries. The analysis of skin mucus biomarkers is a recent alternative approach providing a faster feed-back from the laboratory which is characterized by being less invasive, more rapid and with reduced costs. The effect of replacing fishmeal and fish protein hydrolysates by means of two porcine by-products, the porcine spray-dried plasma (SDPP) and pig protein hydrolysate (PPH), in compound diets (50.4% crude protein, 16.2% crude protein, 22.1 MJ/kg feed) was evaluated in juvenile meagre (Argyrosomus regius) during a two-months period. To determine the impact of these dietary replacements, growth and food performance were measured together with digestive enzymes activities and filet proximal composition. Additionally, skin mucus was collected and characterized by determining main mucus biomarkers (protein, glucose, lactate, cortisol, and antioxidant capacity) and its antibacterial properties, measured by the quick in vitro co-culture challenges. In comparison to the control group, the inclusion of PPH and SDPP, in meagre diets reduced growth (7.4-8.8% in body weight), increased feed conversion ratios (9.0-10.0%), results that were attributed to a reduction in feed intake values (24.2-33.0%) (P < 0.05). Porcine blood by-products did not modify the activity of gastric and pancreatic digestive enzymes as well as those involved in nutrient absorption (alkaline phosphatase) nor liver oxidative stress condition (P > 0.05). In contrast, a reduction in fillet lipid content associated to an increase in fillet protein levels were found in fish fed SDPP and PPH diets (P < 0.05). As compared to the control diet, the dietary replacement did not alter the levels of the skin mucus biomarkers related to stress (cortisol and antioxidant capacity) or nutritional status (soluble protein, glucose and lactate) (P > 0.05). Interestingly, regardless of the worst performance in somatic growth, meagre fed diets containing both tested porcine by-products showed a significantly improved antibacterial capacity of their skin mucus. This enhancement was more prominent for fish fed with the PPH diet, which may be attributed to a higher content of immunomodulatory bioactive compounds in PPH. Further research will be necessary to provide insights on how the inclusion of SDPP and PPH, at the expense of dietary fishmeal and fish protein hydrolysates, affects feed intake and growth performance in meagre. However, the use of skin mucus biomarkers has been demonstrated to be an excellent methodology for a preliminary characterization of the functional feeds, in particular for their prophylactic properties by the study of mucus antibacterial activity.

Growth phase-dependent control of R27 conjugation is mediated by the interplay between the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA and the cAMP regulon.

Plasmids of the incompatibility group HI1 (IncHI1) have been isolated from several Gram-negative pathogens and are associated with the spread of multidrug resistance. Their conjugation is tightly regulated and it is inhibited at temperatures higher than 30°C, indicating that conjugation occurs outside warm-blooded hosts. Using R27, the prototype of IncHI1 plasmids, we report that plasmid transfer efficiency in E. coli strongly depends on the physiological state of the donor cells. Conjugation frequency is high when cells are actively growing, dropping sharply when cells enter the stationary phase of growth. Accordingly, our transcriptomic assays show significant downregulation of numerous R27 genes during the stationary phase, including several tra (transfer) genes. Growth phase-dependent regulation of tra genes transcription is independent of H-NS, a silencer of horizontal gene transfer, and ppGpp and RpoS, regulators of the stationary phase, but highly dependent on the plasmid-encoded regulatory circuit TrhR/TrhY-HtdA. The metabolic sensor cAMP, whose synthesis is chromosomally encoded, is also involved in the growth phase regulation of R27 conjugation by modulating htdA expression. Our data suggest that the involvement of regulators encoded by both chromosome and plasmid are required for efficient physiological control of IncHI1 plasmid conjugation.

A novel role for antibiotic resistance plasmids in facilitating Salmonella adaptation to non-host environments.

It is believed that the main role of plasmids that encode multiple antibiotic resistance is to confer their hosts the ability to survive in the presence of antimicrobial compounds. In the pathogenic bacterium Salmonella, plasmids of the incompatibility group HI1 account for a significant proportion of antibiotic resistance phenotypes. In this work, we show that plasmid R27 has a strong impact on the global transcriptome of Salmonella Typhimurium strain SL1344 when cells grow at low temperature and enter the stationary phase. Down-regulated genes include pathogenicity islands, anaerobic respiration and metabolism determinants. Up-regulated genes include factors involved in the response to nutrient starvation, antimicrobial resistance, iron metabolism and the heat shock response. Accordingly, cells harbouring R27 are more resistant to heat shock than plasmid-free cells. The use of a different IncHI1 plasmid, pHCM1, provided evidence that these plasmids facilitate adaptation of Salmonella to environmental conditions outside their host(s). This is consistent with the fact that conjugative transfer of IncHI1 plasmids only occurs at low temperature. A significant number of the R27-dependent alterations in gene expression could be correlated with expression of a plasmid-encoded orthologue of the global modulator H-NS, which is up-regulated when cells grow at low temperature.

H-NS is a novel transcriptional modulator of the ribonucleotide reductase genes in Escherichia coli.

Ribonucleotide reductases (RNRs) are essential enzymes for DNA synthesis because they are responsible for the production of the four deoxyribonucleotides (dNTPs) from their corresponding ribonucleotides. Escherichia coli contains two classes of aerobic RNRs, encoded by the nrdAB (class Ia) and nrdHIEF (class Ib) operons, and a third RNR class, which is functional under anaerobic conditions and is encoded by the nrdDG (class III) operon. Because cellular imbalances in the amounts of the four dNTPs cause an increase in the rate of mutagenesis, the activity and the expression of RNRs must be tightly regulated during bacterial chromosome replication. The transcriptional regulation of these genes requires several transcription factors (including DnaA, IciA, FIS [factor for inversion stimulation], Fnr, Fur, and NrdR), depending on the RNR class; however, the factors that dictate the expression of some RNR genes in response to different environmental conditions are not known. We show that H-NS modulates the expression of the nrdAB and nrdDG operons. H-NS represses expression both in aerobically and in anaerobically growing cells. Under aerobic conditions, repression occurs at the exponential phase of growth as well as at the transition from the exponential to the stationary phase, a period when no dNTPs are needed. Under anoxic conditions, repression occurs mainly in exponentially growing cells. Electrophoretic mobility assays performed with two DNA fragments from the regulatory region of the nrdAB operon demonstrated the direct interaction of H-NS with these sequences.

Indirect DNA readout by an H-NS related protein: structure of the DNA complex of the C-terminal domain of Ler.

Ler, a member of the H-NS protein family, is the master regulator of the LEE pathogenicity island in virulent Escherichia coli strains. Here, we determined the structure of a complex between the DNA-binding domain of Ler (CT-Ler) and a 15-mer DNA duplex. CT-Ler recognizes a preexisting structural pattern in the DNA minor groove formed by two consecutive regions which are narrower and wider, respectively, compared with standard B-DNA. The compressed region, associated with an AT-tract, is sensed by the side chain of Arg90, whose mutation abolishes the capacity of Ler to bind DNA. The expanded groove allows the approach of the loop in which Arg90 is located. This is the first report of an experimental structure of a DNA complex that includes a protein belonging to the H-NS family. The indirect readout mechanism not only explains the capacity of H-NS and other H-NS family members to modulate the expression of a large number of genes but also the origin of the specificity displayed by Ler. Our results point to a general mechanism by which horizontally acquired genes may be specifically recognized by members of the H-NS family.

New insights in the role of HtdA in the regulation of R27 conjugation.

R27 is the prototype of the IncHI group of conjugative plasmids, which are associated with multidrug resistance in several relevant pathogens. The transfer of this plasmid is thermodependent and all transfer-related genes are encoded in six operons (tra operons). Very little is known about the factors involved in the regulation of the R27 conjugation. This report describes transcriptional studies of the six tra operons. Our results indicate that HtdA, encoded in the R27 plasmid, is involved in the transcriptional repression of four tra operons (F, H, AC and Z). Although HtdA plays a pivotal role in the transcriptional regulation of those operons, it does not exert its effect as a classical repressor. The data indicate the existence of a crosstalk between HtdA and other unknown regulatory factors. The HtdA-mediated regulation of conjugation is independent of the R27 H-NS protein.

Effect of Heat Treatment on Osteoblast Performance and Bactericidal Behavior of Ti6Al4V(ELI)-3at.%Cu Fabricated by Laser Powder Bed Fusion.

Cu addition to alloys for biomedical applications has been of great interest to reduce bacterial growth. In situ-alloyed Ti6Al4V(ELI)-3at.%Cu was successfully manufactured by laser powder bed fusion (L-PBF). Even so, post-heat treatments are required to avoid distortions and/or achieve required/desired mechanical and fatigue properties. The present study is focused on the investigation of microstructural changes in L-PBF Ti6Al4V(ELI)-3at.%Cu after stress relieving and annealing treatments, as well as their influence on osteoblast and bactericidal behavior. After the stress relieving treatment, a homogenously distributed ß phase and CuTi2 intermetallic precipitates were observed over the α' matrix. The annealing treatment led to the increase in amount and size of both types of precipitates, but also to phase redistribution along α lamellas. Although microstructural changes were not statistically significant, such increase in ß and CuTi2 content resulted in an increase in osteoblast proliferation after 14 days of cell culture. A significant bactericidal behavior of L-PBF Ti6Al4V(ELI)-3at.%Cu by means of ion release was found after the annealing treatment, provably due to the easier release of Cu ions from ß phase. Biofilm formation was inhibited in all on Cu-alloyed specimens with stress relieving but also annealing treatment.

Quality of life in children with skin disease: A Spanish sample.

INTRODUCTION: The impact of skin diseases on quality of life varies widely, and some can have an impact similar to that of asthma or cystic fibrosis. MATERIAL AND METHODS: We conducted a cross-sectional, observational and descriptive study with the aim of describing the degree to which quality of life was affected in paediatric patients managed in a dermatology clinic by means of the Children's Dermatology Life Quality Index (CDLQI). RESULTS: In our study, the skin disease with the greatest impact on quality of life was atopic dermatitis, chiefly on account of symptoms like pruritus and insomnia. It was followed by acne, mainly due to the associated negative feelings (shame, sadness, etc.). Quality of life in patients with viral warts and molluscum contagiosum was mostly affected by the treatment, chiefly based on cryotherapy. Most patients with nevi or café-au-lait spots did not have a decreased quality of life, although up to one third of them had negative feelings in relation to their skin disease. DISCUSSION: Atopic dermatitis was the common skin disease that caused the greatest impairment in quality of life in our sample, although other diseases also had an impact on different dimensions of quality of life. We ought to underscore the recommendation to use less painful treatments than cryotherapy for viral warts and molluscum contagiosum, as the impairment in quality of life in paediatric patients with these conditions was mainly due to the treatment.

Differential regulation of horizontally acquired and core genome genes by the bacterial modulator H-NS.

Horizontal acquisition of DNA by bacteria dramatically increases genetic diversity and hence successful bacterial colonization of several niches, including the human host. A relevant issue is how this newly acquired DNA interacts and integrates in the regulatory networks of the bacterial cell. The global modulator H-NS targets both core genome and HGT genes and silences gene expression in response to external stimuli such as osmolarity and temperature. Here we provide evidence that H-NS discriminates and differentially modulates core and HGT DNA. As an example of this, plasmid R27-encoded H-NS protein has evolved to selectively silence HGT genes and does not interfere with core genome regulation. In turn, differential regulation of both gene lineages by resident chromosomal H-NS requires a helper protein: the Hha protein. Tight silencing of HGT DNA is accomplished by H-NS-Hha complexes. In contrast, core genes are modulated by H-NS homoligomers. Remarkably, the presence of Hha-like proteins is restricted to the Enterobacteriaceae. In addition, conjugative plasmids encoding H-NS variants have hitherto been isolated only from members of the family. Thus, the H-NS system in enteric bacteria presents unique evolutionary features. The capacity to selectively discriminate between core and HGT DNA may help to maintain horizontally transmitted DNA in silent form and may give these bacteria a competitive advantage in adapting to new environments, including host colonization.

In Situ Monitoring and Quantitative Determination of R27 Plasmid Conjugation.

Horizontal gene transfer (HGT) by plasmid conjugation is a major driving force in the spread of antibiotic resistance among Enterobacteriaceae. Most of the conjugation studies are based on calculation of conjugation ratios (number of transconjugants/number of donors) after viable counting of transconjugant and donor cells. The development of robust, fast and reliable techniques for in situ monitoring and quantification of conjugation ratios might accelerate progress in understanding the impact of this cellular process in the HGT. The IncHI1 plasmids, involved in multiresistance phenotypes of relevant pathogens such as Salmonella and E. coli, are distinguished by the thermosensitivity of their conjugative transfer. Conjugation mediated by IncHI1 plasmids is more efficient at temperatures lower than 30 °C, suggesting that the transfer process takes place during the environmental transit of the bacteria. In this report, we described a methodology to monitor in situ the conjugation process during agar surface matings of the IncHI1 plasmid R27 and its derepressed derivative drR27 at different temperatures. A three-color-labeling strategy was used to visualize the spatial distribution of transconjugants within the heterogeneous environment by epifluorescence and confocal microscopy. Moreover, the fluorescent labelling was also used to quantify conjugation frequencies in liquid media by flow cytometry.

A New Variant of the aadE-sat4-aphA-3 Gene Cluster Found in a Conjugative Plasmid from a MDR Campylobacter jejuni Isolate.

Campylobacter jejuni is a foodborne pathogen causing bacterial gastroenteritis, with the highest incidence reported in Europe. The prevalence of antibiotic resistance in C. jejuni, as well as in many other bacterial pathogens, has increased over the last few years. In this report, we describe the presence of a plasmid in a multi-drug-resistant C. jejuni strain isolated from a gastroenteritis patient. Mating experiments demonstrated the transference of this genetic element (pCjH01) among C. jejuni by plasmid conjugation. The pCjH01 plasmid was sequenced and assembled, revealing high similarity (97% identity) with pTet, a described tetracycline resistance encoding plasmid. pCjH01 (47.7 kb) is a mosaic plasmid composed of a pTet backbone that has acquired two discrete DNA regions. Remarkably, one of the acquired sequences carried an undescribed variant of the aadE-sat4-aphA-3 gene cluster, providing resistance to at least kanamycin and gentamycin. Aside from the antibiotic resistance genes, the cluster also carries genes coding for putative regulators, such as a sigma factor of the RNA polymerase and an antisigma factor. Homology searches suggest that Campylobacter exchanges genetic material with distant G-positive bacterial genera.

Host-associated variability of the cdtABC operon, coding for the cytolethal distending toxin, in Campylobacter jejuni.

Campylobacter, a major cause of food-borne gastroenteritis worldwide, colonize the gastrointestinal tract of a wide range of animals, being birds the main reservoir. The mechanisms involved in the interaction of Campylobacter with the different hosts are poorly understood. The cytolethal distending toxin, encoded in the cdtABC operon, is considered a pivotal virulence factor during human infection. Differences in the prevalence of cdtABC genes in Campylobacter isolates from three distinct origins (wild birds, broiler chickens and humans) prompted us to further characterize their allelic variability. The sequence of cdtABC is highly conserved among broiler and human isolates. A high diversity of cdtABC alleles was found among wild bird isolates, including several alleles that do not produce any functional CDT. These results suggest that specific variants of the cdtABC operon might define the host range of specific Campylobacter jejuni isolates. Moreover, our data indicate that PCR methodology is inaccurate to characterize the prevalence of the cdt genes, since negative PCR detection can be the result of divergences in the sequence used for primer design rather than indicating the absence of a specific gene.

Gre Factors Are Required for Biofilm Formation in Salmonella enterica Serovar Typhimurium by Targeting Transcription of the csgD Gene.

Rdar biofilm formation of Salmonella typhimurium and Escherichia coli is a common ancient multicellular behavior relevant in cell-cell and inter-organism interactions equally, as in interaction with biotic and abiotic surfaces. With the expression of the characteristic extracellular matrix components amyloid curli fimbriae and the exopolysaccharide cellulose, the central hub for the delicate regulation of rdar morphotype expression is the orphan transcriptional regulator CsgD. Gre factors are ubiquitously interacting with RNA polymerase to selectively overcome transcriptional pausing. In this work, we found that GreA/GreB are required for expression of the csgD operon and consequently the rdar morphotype. The ability of the Gre factors to suppress transcriptional pausing and the 147 bp 5'-UTR of csgD are required for the stimulatory effect of the Gre factors on csgD expression. These novel mechanism(s) of regulation for the csgD operon might be relevant under specific stress conditions.

Evaluating the Functional Properties of Spray-Dried Porcine Plasma in Gilthead Seabream (Sparus aurata) Fed Low Fish Meal Diets.

Blood by-products are an untapped source of high-quality ingredients for aquafeeds, containing a broad variety of cytokines, hormones, growth factors, proteins, bioactive peptides, and amino acids. The effects of the spray-dried porcine plasma (SDPP), a type of processed animal protein on several immune parameters, were evaluated in sea bream using ex vivo and in vitro assays. In this study, fish were fed with two isoproteic, isolipidic, and isoenergetic diets: control diet (7% fish meal, FM) and SDPP diet (2% FM and 5% SDPP). At the end of the 92-days trial, those fed the SDPP diet were larger in body weight (p < 0.05) without differences in feed conversion ratio (p > 0.05). The ex vivo immune stimulation of splenocytes indicated that SDPP had a beneficial effect in promoting systemic immunity, since the surface cell marker (cd4), pro- (il-1ß), and anti-inflammatory (tgf-ß1) cytokines, and genes involved in humoral immunity (IgM) were up-regulated. The co-culture assays of skin mucus corroborated that SDPP enhanced the antibacterial capacity of mucus against V. anguillarum. In addition, main mucus biomarkers did not show significant differences, except for cortisol levels which were lower in the SDPP diet. The present study indicated that SDPP may be considered a functional ingredient in aquafeeds formulated with low FM levels.

Integration host factor alleviates H-NS silencing of the Salmonella enterica serovar Typhimurium master regulator of SPI1, hilA.

Coordination of the expression of Salmonella enterica invasion genes on Salmonella pathogenicity island 1 (SPI1) depends on a complex circuit involving several regulators that converge on expression of the hilA gene, which encodes a transcriptional activator (HilA) that modulates expression of the SPI1 virulence genes. Two of the global regulators that influence hilA expression are the nucleoid-associated proteins Hha and H-NS. They interact and form a complex that modulates gene expression. A chromosomal transcriptional fusion was constructed to assess the effects of these modulators on hilA transcription under several environmental conditions as well as at different stages of growth. The results obtained showed that these proteins play a role in silencing hilA expression at both low temperature and low osmolarity, irrespective of the growth phase. H-NS accounts for the main repressor activity. At high temperature and osmolarity, H-NS-mediated silencing completely ceases when cells enter the stationary phase, and hilA expression is induced. Mutants lacking IHF did not induce hilA in cells entering the stationary phase, and this lack of induction was dependent on the presence of H-NS. Band-shift assays and in vitro transcription data showed that for hilA induction under certain growth conditions, IHF is required to alleviate H-NS-mediated silencing.

Does Clinical Photography Influence Satisfaction With Surgery in Adult Patients Operated on for Spinal Deformity?

BACKGROUND: Recently published data suggest that showing patients operated on for adolescent idiopathic scoliosis or kyphosis their preoperative and postoperative photographs may enhance their satisfaction and self-image as measured by Scoliosis Research Society Health-Related Quality of Life Questionnaire (SRS-22) scores. No data exist for adult spinal deformity (ASD) surgery. The aim of this study is to determine the effect on patient postoperative satisfaction and self-image of showing adult deformity patients their preoperative and postoperative whole body photographs. METHODS: This was a nonconcurrent prospective study. Patients operated on for ASD with a minimum 2-year postoperative follow-up who had preoperative full-body photographs taken by a professional photographer were included. Two follow-up visits were arranged 7 days apart. In the first visit, patients completed the SRS-22 questionnaire, and full-body standing photographs were taken. In the second visit, patients were asked to complete again questions 4, 6, 10, 14, 19 (self-image), 21, and 22 (satisfaction) of the SRS-22 after seeing their preoperative and postoperative full-body photographs. RESULTS: Thirty patients (28 female) were included. The median age at surgery was 50 years (26-76). The median follow-up was 51 months (24-120). SRS-22 results at first visit were: activity 2.79 ± 0.75; self-image 2.71 ± 0.82; pain 2.53 ± 1.10; mental health 3.08 ± 0.77; satisfaction 3.46 ± 1.20; global 2.74 ± 0.72. SRS22 results at second visit were: self-image 2.9 ± 0.75; satisfaction 4.02 ± 0.97. After seeing the preoperative and final follow-up photographs, patients experienced an improvement in SRS-22 self-image (P = .000) and satisfaction domains (P = .011). CONCLUSIONS: In patients operated on for ASD, showing preoperative and postoperative photographs improves patient satisfaction with surgery and self-image. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: Our results could be a starting point for introducing full-body clinical photographs as a routine clinical tool in adult deformity patients undergoing surgery.

Photographic sagittal plane analysis and its clinical correlation after surgery for adult spinal deformity: a preliminary study.

PURPOSE: The aim of this study is to determine the correlation between photographic sagittal parameters and patient-reported outcome measures (PROM) results in adult patients operated on spinal deformity. METHODS: Non-concurrent prospective study. INCLUSION CRITERIA: age at surgery older than 25, minimum 2-year follow-up after a 5 or more level fusion for adult spinal deformity (ASD). Full body lateral standing photographs were taken with adhesive markers placed on ten bony landmarks. SRS-22 and SF-36 questionnaires were completed for every patient. The following photographic parameters were measured: lumbar angle, lumbar curve, thoracic inclination (TI), trunk angle, pelvic tilt, head angle, neck angle, cervicothoracic angle, lumbar vector angle (LVA), dorsal vector angle (DVA), cervical vector angle (CVA), cranial pelvic angle (CrPA), cranial sacral angle (CrSA), fibular inclination angle (FIA) and cranial sagittal vertical axis measured to sacrum (Cr-S), greater trochanter (Cr-GT), knee (Cr-K) and ankle (Cr-A). RESULTS: 65 patients (58 female) operated on ASD in a single institution were included. Age at surgery was 61 years (26-67). Postoperative follow-up was 53 months (24-120). Spearman rank order test showed several significant (p ≤ 0.01) correlations. After multivariate linear regression analysis age, LVA and TI remained as predictors for SRS image scores (corrected r2 0.41), LVA for SRS satisfaction (corrected r2 0.27), CrPA and age for SRS total scores (corrected r2 0.33), FIA and age for SF36 physical functioning (corrected r2 0.36) and CrSA for SF36 role physical (corrected r2 0.14). CONCLUSIONS: Some sagittal photographic parameters may predict mid-term clinical results after ASD surgery.

Is the Cranial Sagittal Vertical Axis (Cr-SVA) a Better Midterm Predictor of Clinical Results Than C7-SVA in Adult Patients Operated on Spinal Deformity After a Minimum 2-Year Follow-Up?

STUDY DESIGN: This is nonconcurrent prospective study approved by the Institutional Research Ethics Committee. OBJECTIVE: The purpose of this study is to determine if the cranial sagittal vertical axis (Cr-SVA) measured in full spine standing radiographs is a better predictor of clinical results than the C7 sagittal vertical axis (C7-SVA) in adult patients operated on spinal deformity with a minimum 2-year follow-up after surgery. SUMMARY OF BACKGROUND DATA: The Cr-SVA has recently been described as a better predictor of health-related quality of life outcomes than the C7-SVA for patients with adult spinal deformity (ASD) before undergoing surgery. This has not been confirmed in patients after ASD surgery. METHODS: Inclusion criteria were age at surgery more than 25 years and a minimum 2-year follow-up after a ≥5 level fusion for ASD. Full-length standing lateral radiographs (including nasion-inion line, spine, and femoral heads) and Scoliosis Research Society 22 Questionnaire and SF36 questionnaires were available for every patient at the final follow-up. The distance from the Cr-SVA to the posterior corner of S1 (Cr-SVA-S) and to the centers of the hip (Cr-SVA-H) was measured and also the C7-SVA, lumbar lordosis, pelvic incidence, pelvic tilt, and PI-LL. RESULTS: Sixty-five patients (58 female individuals) operated on ASD in a single institution were included. Age at surgery was 61 years (26-67). The mean follow-up was 53 months (24-120). Spearman rank-order test showed several significant correlations. After multivariable analysis, only Cr-SVA-S and age persisted as predictors for Scoliosis Research Society (SRS) image scores, Cr-SVA-H for SRS satisfaction, Cr-SVA-H and age for SRS total scores, Cr-SVA-H and age for SF36 Physical Function, Cr-SVA-S for SF36 Role Physical, Cr-SVA-H for SF36 Bodily Pain, and Cr-SVA-H for SF36 Role Emotional. CONCLUSIONS: The Cr-SVA measured in full spine standing radiographs seems to be a better predictor of health-related quality of life outcomes than the C7-SVA for adults operated on spinal deformity >2 years after surgery.