Morphological alterations of the abdominal wall after open incisional hernia repair with endoscopic anterior and open posterior component separation.

PURPOSE: Effects of component separation (CS) on abdominal wall morphology have only been investigated in smaller case series or cadavers. This study aimed to compare abdominal wall alterations following endoscopic anterior CS (EACS) or open transverse abdominis release (TAR). METHODS: Computed tomography scans were evaluated in patients who had undergone open incisional hernia repair with EACS or TAR. Abdominal wall circumference, lateral abdominal wall muscle thickness, and displacement were compared with (1) preoperative images after bilateral CS and (2) the undivided side postoperatively after unilateral CS. RESULTS: In total, 105 patients were included. Fifty-five (52%) and 15 (14%) underwent bilateral and unilateral EACS, respectively. Five (5%) and 14 (13%) underwent bilateral and unilateral TAR, respectively. Sixteen (15%) underwent unilateral EACS and contralateral TAR. The external oblique and transverse abdominis muscles were significantly laterally displaced with a mean of 2.74 cm (95% CI 2.29-3.19 cm, P < 0.001) and 0.82 cm (0.07-1.57 cm, P = 0.032) after EACS and TAR, respectively. The combined thickness of the lateral muscles was significantly decreased after EACS (mean decrease 10.5% (5.8-15.6%, P < 0.001)) and insignificantly decreased after TAR (mean decrease 2.6% (- 4.8 to 9.5%, P = 0.50)). The abdominal wall circumference was unchanged after bilateral (mean reduction 0.90 cm (- 0.77 to 2.58 cm), P = 0.29) and unilateral CS (mean increase 0.03 cm (- 1.01 to 1.08 cm), P = 0.95). CONCLUSION: Postoperative changes in the lateral abdominal wall musculature were different following EACS and open TAR. Either technique seems not to compromise the overall integrity of the lateral abdominal wall.

Abdominal wound dehiscence is dangerous: a nationwide study of 14,169 patients undergoing elective open resection for colonic cancer.

PURPOSE: The potential impact of abdominal wound dehiscence on long-term survival after elective abdominal surgery is largely unknown. The aim of this study was to examine the impact of abdominal wound dehiscence on survival and incisional hernia repair after elective, open colonic cancer resection. METHODS: This was a nationwide cohort study based on merged data from Danish national registries, comprising patients subjected to elective, open resection for colonic cancer between May 1, 2001 and January 1, 2016. Multivariable Cox Regression analysis and propensity score matching was applied to adjust for confounding. The associations of abdominal wound dehiscence with 90-day mortality and subsequent incisional hernia repair were also examined. RESULTS: A total of 14,169 patients were included in the cohort, of which 549 (3.9%) developed abdominal wound dehiscence. The 5-year survival was significantly decreased in patients with abdominal wound dehiscence (42.4%, 95% CI 38.1-46.7 vs. 53.4%, 52.6-54.3, P < 0.001), which was confirmed in the multivariable analysis (HR 1.22, CI 1.06-1.39, P = 0.004). Abdominal wound dehiscence was significantly associated with increased risk of 90-day mortality (OR 1.60, CI 1.12-2.27, P = 0.009) as well as subsequent incisional hernia repair (HR 1.80, CI 1.07-3.01, P = 0.026). CONCLUSIONS: Abdominal wound dehiscence was significantly associated with decreased survival. Fascial closure after open colonic cancer resection should be given high priority to improve the long-term survival.

Changes in the abdominal wall after anterior, posterior, and combined component separation.

KEY MESSAGE: Knowledge of the changes that occur in the abdominal wall after component separation (CS) is essential for understanding the mechanisms of action of the various CS techniques, the changes observed on computed tomography images, and, perhaps most importantly, the anatomic and physiologic changes observed in patients who have undergone CS. Purpose Component separation (CS) techniques are essential adjuncts during most abdominal wall reconstructions. They allow the fulfillment of most modern abdominal wall reconstruction principles, especially primary closure of defects and linea alba restoration under physiologic tension. Knowledge of the post-CS abdominal wall changes is essential to understanding the mechanism of action of the various types of CS, the changes observed on computed tomographic images, and, perhaps most importantly, the anatomic and physiologic changes following CS techniques. Methods A systematic review of the literature was conducted using the PubMed database and other sources to identify articles describing abdominal wall changes after CS Results After excluding non-pertinent articles, 14 articles constituted the basis for this review.  Conclusions After reviewing the literature on post CS abdominal wall changes, we conclude the following: (1)The external oblique muscle is significantly displaced laterally after anterior CS, the transversus abdominis muscle shifts very little after posterior CS, and muscle trophism is generally maintained after both techniques. These findings are consistent for both open and minimally invasive CS. (2) The anatomy and physiology of abdominal wall muscles are preserved mainly by the muscles' overlapping function and their ability to undergo compensatory trophism after midline restoration (reloading). (3) Well-performed CS techniques have a low risk of producing bulging and semilunar line hernias. (4) Anterior and posterior CS techniques probably have different mechanisms of action. (5) Current studies on how the nutritional status and postoperative conditioning can alter abdominal wall changes after CS and the mechanisms of the actions involved in anterior and posterior CS are underway.

Prophylactic negative pressure wound therapy after open ventral hernia repair: a systematic review and meta-analysis.

PURPOSE: Negative pressure wound therapy on closed incisions (iNPWT) is a wound dressing system developed to promote wound healing and avoid complications after surgical procedures. The effect of iNPWT is well established in various surgical fields, however, the effect on postoperative wound complications after ventral hernia repair remains unknown. The aim of this systematic review and meta-analysis was to investigate the effect of iNPWT on patients undergoing open ventral hernia repair (VHR) compared with conventional wound dressing. MATERIALS AND METHODS: This systematic review and meta-analysis followed the PRISMA guidelines. The databases PubMed, Embase, Cochrane Library, Web of science and Cinahl were searched for original studies comparing iNPWT to conventional wound dressing in patients undergoing VHR. The primary outcome was surgical site occurrence (SSO), secondary outcomes included surgical site infection (SSI) and hernia recurrence. RESULTS: The literature search identified 373 studies of which 10 were included in the meta-analysis including a total of 1087 patients. Eight studies were retrospective cohort studies, one was a cross-sectional pilot study, and one was a randomized controlled trial. The meta-analysis demonstrated that iNPWT was associated with a decreased risk of SSO (OR 0.27 [0.19, 0.38]; P < 0.001) and SSI (OR 0.32 [0.17, 0.55]; P < 0.001). There was no statistically significant association with the risk of hernia recurrence (OR 0.62 [0.27, 1.43]; P = 0.26). CONCLUSION: Based on the findings of this systematic review and meta-analysis iNPWT following VHR was found to significantly reduce the incidence of SSO and SSI, compared with standard wound dressing. INPWT should be considered for patients undergoing VHR.

Should simultaneous stoma closure and incisional hernia repair be avoided?

PURPOSE: Patients scheduled for stoma closure may also have an incisional hernia. Studies have reported acceptable outcomes after contaminated ventral hernia repair, but whether stoma closure and incisional hernia repair should be performed as a combined procedure is unknown. This study examined combined stoma closure and incisional hernia repair compared with incisional hernia repair only. METHODS: This was a nationwide propensity-score matched study. Patients who underwent elective incisional hernia repair from 2007-2017 were identified in the Danish Hernia Database. All patients who underwent concurrent stoma closure were matched 1:3 with patients who underwent incisional hernia repair only. The primary outcome was reoperation for hernia recurrence, whereas secondary outcomes included anastomotic leakage, length of hospital stay, and 30-day reoperation and readmission rates. RESULTS: In total, 516 patients were included. The risk of reoperation for recurrence was increased after concurrent stoma closure compared with incisional hernia repair only (hazard ratio 1.69, 95% confidence interval 1.01-2.82, p = 0.044). Seven (5.4%) patients who underwent incisional hernia repair concurrent to stoma closure were reoperated for anastomotic leakage. Length of hospital stay and reoperation rates within 30 days were increased after concurrent stoma closure compared with incisional hernia repair only (median 8 versus 3 days, p < 0.001 and 29.5% versus 18.6%, p = 0.013), whereas there was no difference in 30-day readmission rates (p = 0.251). CONCLUSIONS: Stoma closure and incisional hernia repair should be performed as a dual-stage procedure to decrease the risk of hernia recurrence.

Mesh versus suture in elective repair of umbilical hernia: systematic review and meta-analysis.

BACKGROUND: Mesh repair of umbilical hernia has been associated with a reduced recurrence rate compared with suture closure, but potentially at the expense of increased postoperative complications and chronic pain. The objective of this systematic review and meta-analysis was to examine the outcomes after elective open mesh and suture repair for umbilical hernia in adults. METHODS: A literature search was conducted to identify studies presenting original data on elective open mesh and suture repair of umbilical hernia. The primary outcome was hernia recurrence. Secondary outcomes included surgical-site infection (SSI), seroma, haematoma and chronic pain. Meta-analyses were undertaken. RESULTS: The search resulted in 5353 hits and led to 14 studies being included (6 RCTs and 8 observational studies) describing a total of 2361 patients. Compared with suture, mesh repair was associated with a lower risk of recurrence (risk ratio (RR) 0·48, 95 per cent c.i. 0·30 to 0·77), with number needed to treat 19 (95 per cent c.i. 14 to 31). Mesh repair was associated with a higher risk of seroma (RR 2·37, 1·45 to 3·87), with number needed to harm 30 (17 to 86). There was no significant difference in the risk of SSI, haematoma or chronic pain. CONCLUSION: The use of mesh in elective repair of umbilical hernia reduced the risk of recurrence compared with suture closure without altering the risk of chronic pain.

ANTECEDENTES: La reparación con malla de la hernia umbilical se ha asociado con una tasa menor de recidivas en comparación con el cierre con suturas, pero potencialmente a expensas de un aumento de complicaciones postoperatorias y dolor crónico. El objetivo de esta revisión sistemática y metaanálisis fue examinar los resultados después de reparación abierta electiva con malla o suturas para la reparación de una hernia umbilical en adultos. MÉTODOS: Se llevó a cabo una búsqueda en la literatura para identificar estudios que presentaban datos originales sobre la reparación abierta electiva con malla y sutura de la hernia umbilical. El resultado primario fue la recidiva herniaria. Los resultados secundarios incluyeron la infección del sitio quirúrgico (surgical site infection, SSI), seroma, hematoma y dolor crónico. Se realizaron metaanálisis. RESULTADOS: En la búsqueda identificaron 5.353 documentos, incluyéndose 14 estudios (6 ensayos clínicos aleatorizados, 8 estudios observacionales) que presentaban datos de un total de 2.361 pacientes. En comparación con la sutura, la reparación con malla se asoció con un menor riesgo de recidiva (tasa de riesgo, risk ratio, RR 0,48, i.c. del 95% 0,30 a 0,77) y número necesario para tratar de 19 (i.c. del 95% 14 a 31). La reparación con malla se asoció con un mayor riesgo de seroma (RR 2,37, i.c. del 95% 1,45 a 3,87) y número necesario para provocar daño de 30 (i.c. del 95% 17 a 86). No hubo diferencia significativa en el riesgo de SSI, hematoma o dolor crónico. CONCLUSIÓN: El uso de malla en la reparación electiva de la hernia umbilical redujo el riesgo de recidiva en comparación con el cierre con sutura, sin modificar el riesgo de dolor crónico.

Diverse biological processes coordinate the transcriptional response to nutritional changes in a Drosophila melanogaster multiparent population.

BACKGROUND: Environmental variation in the amount of resources available to populations challenge individuals to optimize the allocation of those resources to key fitness functions. This coordination of resource allocation relative to resource availability is commonly attributed to key nutrient sensing gene pathways in laboratory model organisms, chiefly the insulin/TOR signaling pathway. However, the genetic basis of diet-induced variation in gene expression is less clear. RESULTS: To describe the natural genetic variation underlying nutrient-dependent differences, we used an outbred panel derived from a multiparental population, the Drosophila Synthetic Population Resource. We analyzed RNA sequence data from multiple female tissue samples dissected from flies reared in three nutritional conditions: high sugar (HS), dietary restriction (DR), and control (C) diets. A large proportion of genes in the experiment (19.6% or 2471 genes) were significantly differentially expressed for the effect of diet, and 7.8% (978 genes) for the effect of the interaction between diet and tissue type (LRT, Padj. < 0.05). Interestingly, we observed similar patterns of gene expression relative to the C diet, in the DR and HS treated flies, a response likely reflecting diet component ratios. Hierarchical clustering identified 21 robust gene modules showing intra-modularly similar patterns of expression across diets, all of which were highly significant for diet or diet-tissue interaction effects (FDR Padj. < 0.05). Gene set enrichment analysis for different diet-tissue combinations revealed a diverse set of pathways and gene ontology (GO) terms (two-sample t-test, FDR < 0.05). GO analysis on individual co-expressed modules likewise showed a large number of terms encompassing many cellular and nuclear processes (Fisher exact test, Padj. < 0.01). Although a handful of genes in the IIS/TOR pathway including Ilp5, Rheb, and Sirt2 showed significant elevation in expression, many key genes such as InR, chico, most insulin peptide genes, and the nutrient-sensing pathways were not observed. CONCLUSIONS: Our results suggest that a more diverse network of pathways and gene networks mediate the diet response in our population. These results have important implications for future studies focusing on diet responses in natural populations.

Incisional hernia repair in women of childbearing age: A nationwide propensity-score matched study.

BACKGROUND & AIMS: Although incisional hernia repair in women of childbearing age is not rare, hernia disease in this group of patients is sparsely documented. The aim of this study was to examine long-term clinical results after incisional hernia repair in women of childbearing age. MATERIAL AND METHODS: This nationwide cohort study examined incisional hernia repair from 2007 to 2013 in women of childbearing age, registered prospectively in the Danish Ventral Hernia Database. All women with a subsequent pregnancy were included, and a 1:3 propensity-score matched group of women with an incisional hernia repair without a subsequent pregnancy. A prospective follow-up was conducted, including a validated questionnaire. The primary outcome was recurrence, and the secondary outcome was chronic pain from the operated site. RESULTS: In total, 124 (70.5%) women responded, 47 and 77 women with and without a subsequent pregnancy, respectively. The 5-year cumulative incidence of recurrence was 41.0% (95% confidence interval 32.0%-49.9%). After adjustment for potential confounders, subsequent pregnancy was independently associated with recurrence (hazard ratio 1.83, 95% confidence interval 1.02-3.29, p = 0.044). Twenty-six (21.0%) women reported chronic pain (moderate, n = 21; severe, n = 5) with no difference between women with and without a subsequent pregnancy. Hernia recurrence, higher body mass index, and smoking were associated with chronic pain. CONCLUSION: Pregnancy following incisional hernia repair was associated with an increased risk of recurrence, but not with chronic pain.

Clinical outcomes after parastomal hernia repair with a polyester monofilament composite mesh: a cohort study of 79 consecutive patients.

PURPOSE: Different techniques and mesh materials are used in parastomal hernia repair with recently reported recurrence rates ranging from 10 to 28%. The aim of this cohort study was to examine the risk of recurrence and chronic pain after Sugarbaker or keyhole parastomal hernia repair with intraperitoneal placement of a polyester monofilament macroporous composite mesh. METHODS: Data on all patients undergoing parastomal hernia repair with Parietex™ Composite Parastomal Mesh at our institution during a 4-year period were examined. Patients with urostomy were excluded. A team of three experienced surgeons performed all repairs. Follow-up including physical examination was done after 10 days, 6 and 12 months, and hereafter as annual structured telephone interviews. Patients suspected of hernia recurrence were offered computed tomography scan. Chronic pain was defined as pain requiring out-patient visit(s) and/or regular use of analgesics. RESULTS: 79 patients (Sugarbaker, n = 69; keyhole, n = 10) were included. Of those, 72 procedures were performed laparoscopically and seven by open technique. Two patients were reoperated within 30 days with removal of the mesh. In total, seven (9%) patients had parastomal hernia recurrence (reoperation, n = 3; conservative management, n = 4) during follow-up of median 12 months (range 0-49 months). In univariable logistic analyses, type of stoma was associated with recurrence (ileostomy 28% vs colostomy 3%, p = 0.007). Three patients (4%) reported chronic pain. CONCLUSION: In this study, we found low rates of recurrence and chronic pain following parastomal hernia repair using intraperitoneal reinforcement with a polyester monofilament composite mesh.

Insuffisance cardiaque de l'adulte : Une étude sur 130 cas à l'hôpital au Service de cardiologie de l'hôpital national de Niamey au Niger

Nous rapportons dans cette étude les aspects épidémiologiques, diagnostiques, évolutifs et pronostiques de l'insuffisance cardiaque du sujet âgé de plus de 15 ans en milieu hospitalier nigérien. C'est une étude prospective menée en quatre (4) mois. Elle a concerné des sujets des deux sexes âgés de plus de 15 ans, admis dans un tableau d'insuffisance cardiaque. Nous avons inclus 103 cas soit 35,15% des 293 patients: 59 hommes (57,30%), 44 femmes (42,70%) (p =1,34) âgés en moyenne de 55,05 ans (extrêmes : 17 et 96 ans), la tranche d'âge la plus touchée était celle de plus de 65 ans (n= 36, soit 34,96%). Les facteurs de risque les plus fréquents étaient l'HTA (n=59, soit 49,50%), le tabac (n=13, soit 12,62%), le diabète (n=9, soit 8,73%).L'insuffisance cardiaque était globale (n = 79, soit 76,70%), gauche (n=21, soit 20,38%), et droite exclusive (n=3, soit 2,91%). Les cardiopathies en cause étaient, ischémiques (n=37, soit 35,92%), hypertensives (n = 32, soit 31,06%), les valvulopathies (n=12, soit 11,65%), CMPP (n=8, soit 7,76%), un cœur pulmonaire chronique a été objectivé dans 4 cas (3,88%) de même qu'une péricardite dans 4 cas (3,88%), les cardiomyopathies hypertrophiques (n=3, soit 2,77%). Une endocardite dans 1 cas et une cardiothyréose chez un seul patient. Le traitement a été exclusivement médical avec les diurétiques dans 94,17%, les inhibiteurs de l'enzyme de conversion (IEC) dans 94,20%, les bétabloquants (BB) dans 52,42% et les dérivés nitrés dans 18,44%. La létalité a été de 5,82% (n=6). La prévention consiste à lutter contre l'ensemble des facteurs de risque notamment l'HTA dont la prévention primaire s'avère ainsi nécessaire

Primary ventral or groin hernia in pregnancy: a cohort study of 20,714 women.

BACKGROUND: Prevalence, management, and risk of emergency operation for primary ventral or groin hernia in pregnancy are unknown. The objective of this study was to estimate the prevalences of primary ventral or groin hernia in pregnancy and the potential risks for elective and emergency repair. METHODS: This single-institutional retrospective study included all pregnant women attending one or more prenatal consultations at Hvidovre Hospital, Denmark, during a 3-year period. Patients' medical records were electronically retrieved. A free-text search algorithm and subsequent manual review was conducted to identify patients registered with a primary ventral or groin hernia in pregnancy. Follow-up was conducted by review of medical record notes within the Capital Region of Denmark supplemented with structured telephone interviews on indication. RESULTS: In total, 20,714 pregnant women were included in the study cohort. Seventeen (0.08%) and 25 (0.12%) women were registered with a primary ventral and groin hernia, respectively. None underwent elective or emergency repair in pregnancy, and all had uncomplicated childbirth. In 10 women, the groin bulge disappeared spontaneously after delivery. During postpartum follow-up of median 4.4 years (range 0.2-6.0 years), five (0.02%) and four (0.02%) underwent elective primary ventral and groin hernia repair, respectively. CONCLUSION: Primary ventral or groin hernia seems rare in pregnancy, and the incidence of emergency repair is extremely low. Watchful waiting strategy is recommended during pregnancy in women suspected for a primary ventral or groin hernia.

Colonic diverticulosis is associated with abdominal wall hernia.

PURPOSE: Colonic diverticulosis and abdominal wall hernia are common pathologies. Studies have suggested that connective tissue alterations play a role in the formation of both diverticulosis and abdominal wall hernia. The aim of this cohort study was to evaluate the association between diverticulosis and abdominal wall hernia in a large cohort of patients undergoing colonoscopy. METHODS: All consecutive patients who underwent colonoscopy between 2001 and 2013 at Bispebjerg Hospital were eligible for inclusion. The endoscopists prospectively registered the findings of diverticulosis in a database. Data were merged with the Danish Hernia Database identifying patients who underwent groin and ventral hernia repair. Calculated odds ratios (ORs) were used to describe the extent of association and multivariable logistic regression models were utilized to adjust for age and gender. RESULTS: A total of 13,855 patients were included, 3685 (26.6%) of whom were diagnosed with diverticulosis. Diverticulosis was independently associated with direct inguinal, OR 1.33, 95% CI 1.00-1.76, P = 0.049, and umbilical/epigastric hernia repair, OR 1.74, 95% CI 1.16-2.63, P = 0.008. CONCLUSIONS: Colonic diverticulosis was associated with direct inguinal and umbilical/epigastric hernia repair suggesting that connective tissue alterations, herniosis, could be a common etiologic factor of colonic diverticulosis and these abdominal wall hernias.

Genetic and morphological studies of Nothobranchius (Cyprinodontiformes) from Malawi with description of Nothobranchius wattersi sp. nov.

Molecular and morphological data were used to explore evolutionary differentiation among populations of Nothobranchius in the Lake Malawi-upper Shire River and the Lakes Chilwa-Chiuta drainage systems in Malawi. The aim of the study was to test the hypothesis that Nothobranchius of the Malawi-Shire system constitute a separate evolutionary group from Nothobranchius kirki. Mitochondrial and nuclear sequence data show a strongly supported phylogenetic split into two monophyletic groups separating the Lake Malawi basin fish from N. kirki. Unlike N. kirki, Lake Malawi-Shire fish do not deviate from neutrality and express an excess of rare haplotypes and mutations in terminal branches, characteristic of recently expanded populations. Further, the two groups significantly differ in morphology. Two body characters (dorsal-fin base length and pre-pelvic-pre-anal distance) are significantly different between the two species in both sexes. Several other characters are significantly different in either male or female comparisons with respect to both standard and head lengths, and robust morphological differentiation is detected by multivariate analysis. The two groups are readily distinguished on the basis of male colouration, especially in scale centres and the caudal fin. On the basis of this differentiation at the molecular and morphological levels, in addition to colouration, the Lake Malawi-Shire fish are hereby formally recognized as constituting a new species, Nothobranchius wattersi. This distinction is in agreement with the geomorphologic and recent climatic history in the region.

Fracture union following internal fixation in the HIV population.

INTRODUCTION: HIV is thought to be associated with increased rates of fracture non-union. We report on a prospective cohort of 96 HIV positive patients with 107 fractures that required internal fixation. The CD4 count was measured and patients were reviewed until eventual clinical or radiological union or non-union was established. RESULTS: Four percent of fractures (4 out of 100) failed to unite. Three patients required one further procedure to induce union, and two developed avascular necrosis. The CD4 count was not related to fracture union. CONCLUSION: Contrary to previous assumptions, this study suggests that HIV infection does not increase rates of non-union in surgically managed fractures.

Phylogeny, genetic variability and colour polymorphism of an emerging animal model: the short-lived annual Nothobranchius fishes from southern Mozambique.

Nothobranchius are a group of small, extremely short-lived killifishes living in temporary savannah pools in Eastern Africa and that survive annual desiccation of their habitat as dormant eggs encased in dry mud. One mitochondrial (COI) and three nuclear (CX32.2, GHITM, PNP) loci were used to investigate the phylogenetic relationship of Nothobranchius species from southern and central Mozambique. This group shows marked variation in captive lifespan at both the inter- and intraspecific levels; lifespan varies from a few months to over a year. As their distribution encompasses a steep gradient between semi-arid and humid habitats, resulting in contrasting selection pressures on evolution of lifespan and associated life history traits, Mozambican Nothobranchius spp. have recently become a model group in studies of ageing, age-related disorders and life history evolution. Consequently, intraspecific genetic variation and male colour morph distribution was also examined in the recovered clades. Using Bayesian species tree reconstruction and single loci analyses, three large clades were apparent and their phylogenetic substructure was revealed at the inter- and intra-specific levels within those clades. The Nothobranchius furzeri and Nothobranchius orthonotus clades were strongly geographically structured. Further, it was demonstrated that male colour has no phylogenetic signal in N. furzeri, where colour morphs are sympatric, but is associated with two reciprocally monophyletic groups in Nothobranchius rachovii clade, where colour morphs are parapatric. Finally, our analysis showed that a polymorphism in the Melanocortin1 receptor gene (which controls pigmentation in many vertebrates and was a candidate gene of male colouration in N. furzeri) is unrelated to colour phenotypes of the study species. Our results raise significant implications for future comparative studies of the species and populations analysed in the present work.

The genome of Melanoplus sanguinipes entomopoxvirus.

The family Poxviridae contains two subfamilies: the Entomopoxvirinae (poxviruses of insects) and the Chordopoxvirinae (poxviruses of vertebrates). Here we present the first characterization of the genome of an entomopoxvirus (EPV) which infects the North American migratory grasshopper Melanoplus sanguinipes and other important orthopteran pests. The 236-kbp M. sanguinipes EPV (MsEPV) genome consists of a central coding region bounded by 7-kbp inverted terminal repeats and contains 267 open reading frames (ORFs), of which 107 exhibit similarity to previously described genes. The presence of genes not previously described in poxviruses, and in some cases in any other known virus, suggests significant viral adaptation to the arthropod host and the external environment. Genes predicting interactions with host cellular mechanisms include homologues of the inhibitor of apoptosis protein, stress response protein phosphatase 2C, extracellular matrixin metalloproteases, ubiquitin, calcium binding EF-hand protein, glycosyltransferase, and a triacylglyceride lipase. MsEPV genes with putative functions in prevention and repair of DNA damage include a complete base excision repair pathway (uracil DNA glycosylase, AP endonuclease, DNA polymerase beta, and an NAD+-dependent DNA ligase), a photoreactivation repair pathway (cyclobutane pyrimidine dimer photolyase), a LINE-type reverse transcriptase, and a mutT homologue. The presence of these specific repair pathways may represent viral adaptation for repair of environmentally induced DNA damage. The absence of previously described poxvirus enzymes involved in nucleotide metabolism and the presence of a novel thymidylate synthase homologue suggest that MsEPV is heavily reliant on host cell nucleotide pools and the de novo nucleotide biosynthesis pathway. MsEPV and lepidopteran genus B EPVs lack genome colinearity and exhibit a low level of amino acid identity among homologous genes (20 to 59%), perhaps reflecting a significant evolutionary distance between lepidopteran and orthopteran viruses. Divergence between MsEPV and the Chordopoxvirinae is indicated by the presence of only 49 identifiable chordopoxvirus homologues, low-level amino acid identity among these genes (20 to 48%), and the presence in MsEPV of 43 novel ORFs in five gene families. Genes common to both poxvirus subfamilies, which include those encoding enzymes involved in RNA transcription and modification, DNA replication, protein processing, virion assembly, and virion structural proteins, define the genetic core of the Poxviridae.