The value of Wound, Ischemia and foot Infection classification in patients undergoing endovascular therapy.

OBJECTIVE: This study aimed to evaluate the correlation between the Society for Vascular Surgery (SVS) Wound, Ischemia and foot infection (WIfI) classification system and clinical outcomes for 1-year limb amputation-free survival (AFS), freedom from reintervention, and wound healing rate in a cohort of patients affected by chronic limb-threatening ischemia treated exclusively by endovascular procedures. METHODS: We analyzed a prospective, consecutive cohort of 203 patients (203 limbs) who underwent infrainguinal endovascular revascularization at a single center between March 2018 and January 2021. These patients were stratified into clinical stages 1 to 4 based on the SVS WIfI classification and categorized into two groups: WIfI 1 to 3 (n = 101 limbs) and WIfI 4 (n = 102 limbs). The SVS objective performance goals of 1-year limb AFS, freedom from reintervention, and wound healing were compared between the groups and assessed using the Kaplan-Meier method. Angiographic lesion characteristics and angioplasty details were compared. RESULTS: The average age was 72.4 years (44.3% male, 85.2% had hypertension, 80.3% had diabetes, and 87.7% had tissue loss). There were statistical differences between the groups in 1-year limb AFS Kaplan-Meier rate between WIfI clinical stages 1 to 3 group and WIfI clinical stage 4 group (82% vs 66%, respectively; P < .001), but there was no statistical difference in freedom from reintervention and wound healing rates between the groups (70% vs 64% [P = .62] and 74% vs 79% [P = .90], respectively). Owing to angiographic lesion characteristics, femoropopliteal and infrapopliteal segment distributions were similar between the groups, but there was a statistical difference in target lesion location to tibial vessels (55.4% vs 71.6%, respectively; P = .025). CONCLUSIONS: In this cohort of patients with chronic limb-threatening ischemia, SVS WIfI clinical stage 4 had worse results in the 1-year limb AFS rate, but there was no statistical difference in freedom from reintervention and wound healing rates between the groups.

Efficacy and safety of iliofemoral bypass using arm veins as an alternative conduit for chronic limb-threatening ischemia.

OBJECTIVE: The use of basilic vein in iliofemoral revascularizations was previously described in the literature as an autologous option for the treatment of vascular prosthesis infection and as a primary conduit in patients at high risk of infectious surgical complications. However, the publications available include several different indications and are limited to case reports. Therefore, the aim of this study was to evaluate the outcomes of the use of arm veins as a safe and effective autologous alternative for iliofemoral reconstruction in patients with chronic limb-threatening ischemia (CLTI) and at high risk of prosthesis infection. METHODS: We performed a multicenter, retrospective cohort study with 53 consecutive iliofemoral bypasses using arm veins as an alternative conduit. The procedures were performed between November 2013 and November 2021, exclusively for patients with CLTI classified as TASC aortoiliac C or D with increased risk of postoperative surgical infection. Demographic, clinical variables, and outcomes were collected from a prospective database. Main endpoints were amputation-free survival (AFS) and major adverse cardiovascular events. Secondary endpoints included primary and secondary patencies and overall survival. Cox regression analysis was used to identify the predictors of AFS. Postoperative surgical complications and 30-day mortality were also assessed. RESULTS: The mean age was 64.2 ± 8.4 years, with a predominance of male gender. The median follow-up period was 615 days. All patients had CLTI, with a predominance of tissue loss (n = 51; 96.2%) and a median ankle-brachial index of 0.28. The basilic vein was utilized in most procedures (69.8%). Thirty-day major adverse cardiovascular events occurred in five cases (9.4%), and the 30-day mortality rate was 3.8%. The AFS, primary patency, secondary patency, and overall survival in 720 days were 71%, 72%, 89%, and 75%, respectively. Cox regression analysis revealed no association between the variables analyzed for AFS. There was no graft late infection nor pseudoaneurysmal degeneration. CONCLUSIONS: Iliofemoral bypass using arm veins as an autologous conduit proved to be an effective and safe procedure with low incidence of postoperative cardiovascular complications and high rates of AFS in patients with CLTI. Also, this suggests that arm veins can be an interesting and suitable autologous alternative conduit for iliofemoral reconstructions, especially in cases in which a prosthesis should be avoided or when it is not available.

Late Outcomes of Elective Endovascular Abdominal Aortic Aneurysm Repair in a Tertiary Low-Volume Hospital in Brazil.

BACKGROUND: The aim of this study is to report early and long-term results of elective endovascular aneurysm repair (EVAR) in a tertiary low-volume hospital in Brazil. METHODS: Between October 2006 and May 2017, 120 patients underwent elective EVAR for infrarenal aortic aneurysm. The interventions were reviewed retrospectively, focusing on 30-day mortality, long-term survival, and freedom from reintervention. Late outcomes were assessed by the Kaplan-Meier method and Cox regression. RESULTS: The follow-up's median and interquartile range was 3 (1-5) years. Overall, most patients were males (75%) and the median age was 74 years. Mostly patients were at a high risk for intervention (79.1%) and the majority was classified as American Society of Anesthesiologists III (53.3%). Preoperative aneurysm diameter median was 60 mm, interquartile range was 52.7-69. As per the postoperative aneurysm sac evolution, the number of patients with a reduction, stabilization, or an increase was 93 (77.5%), 18 (15%), and 9 (7.5%), respectively. The 30-day mortality was 6.6% and no late aneurysm-related deaths were identified. The overall incidence of late endoleaks was 24.1%, with the predominance of type II (23.3%), followed by type IA (0.8 %). Secondary interventions were necessary for 9 patients (7.5%). The 6-year analyses revealed freedom from reintervention and overall survival of 87.9% and 57.7%, respectively. The Cox regression analyses identified age > 75 years as an adverse factor for overall survival (hazard ratio = 2.5; P = 0.021). CONCLUSIONS: In the present study, EVAR in a low-volume center was associated with high 30-day mortality, but satisfactory long-term results were identified.

Cardiovascular Risk Assessment in Women With Rheumatoid Arthritis Through Carotid and Femoral Artery Doppler Ultrasound.

OBJECTIVE: The aims of this study were to assess cardiovascular risk in patients with rheumatoid arthritis (RA) classified as low-risk by the Framingham score, before and after the multiplication by 1.5 recommended by the European League Against Rheumatism (EULAR), and to stratify them using carotid and femoral Doppler ultrasound (DUS) in order to optimize the assessment of the asymptomatic cardiovascular disease incidence. METHODS: Thirty-five female patients with RA and 35 healthy women (control group), both with low cardiovascular risk by Framingham score, were enrolled in the study (randomized). All of them underwent carotid and femoral DUS studies. RESULTS: The mean age at diagnosis was 44.57 years, the mean disease duration was 12.11 years and the mean disease activity score according to the Disease Activity Score 28 was 1.91, whereas according to the Clinical Disease Activity Index, it was 6.176. The sample was homogeneous. Within the RA group, 46% showed changes in the carotid and/or femoral DUS, compared with 14% in the control group (p = 0.004). Of the DUS with abnormalities, in the RA group, 31% of the carotid DUS and 81% of the femoral DUS (p = 0.005) showed intima-media thickness and/or atherosclerotic plaques. After EULAR 1.5 multiplication factor, 66% remained low cardiovascular risk. Of these, 35% of the patients showed changes in the carotid and/or femoral DUS, compared with 14% of the control group (p = 0.07). CONCLUSIONS: The EULAR criteria are effective at identifying patients with high cardiovascular risk. Carotid DUS and, especially, femoral DUS are tools that can be used in clinical practice as ways to detect CVD even in its asymptomatic form.

Whole-Genome sequencing and comparative genomics of Mycobacterium spp. from farmed Atlantic and coho salmon in Chile.

Several members of the Mycobacterium genus cause invasive infections in humans and animals. According to a recent phylogenetic analysis, some strains of Mycobacterium salmoniphilum (Msal), which are the main culprit in bacterial outbreaks in freshwater fish aquaculture, have been assigned to a separate branch containing Mycobacterium franklinii (Mfra), another species that causes infections in humans. However, this genus is little studied in an aquaculture context. Here, we isolated four Mycobacterium spp. strains from freshwater cultures of Atlantic and coho salmon in Chile and performed whole-genome sequencing for deep genomic characterization. In addition, we described the gross pathology and histopathology of the outbreaks. Several bioinformatic analyses were performed using the genomes of these four Mycobacterium isolates in conjunction with those of Msal strains, four Msal-like strains, and one Mfra strains, plus 17 other publicly available Mycobacterium genomes. We found that three isolates are clustered into the Msal branch, whereas one isolate clustered with the Mfra/Msal-like strains. We further evaluated the presence of virulence and antimicrobial resistance genes and observed that the four isolates were closely related to the Msal and Msal-like taxa and carried several antimicrobial resistance and virulence genes that are similar to those of other pathogenic members of the Mycobacterium clade. Altogether, our characterization Msal and Msal-like presented here shed new light on the basis of mycobacteriosis provides quantitative evidence that Mycobacterium strains are a potential risk for aquaculture asetiological agents of emerging diseases, and highlight their biological scopes in the aquaculture industry.

WIfI Classification Versus Angiosome Concept: A Change in the Infrapopliteal Angioplasties Paradigm.

OBJECTIVE: The objective of this study was to determine whether the angiosome concept and WIfI classification in patients undergoing endovascular treatment is associated with the limb salvage rate and wound healing rate in patients with critical limb ischemia(CLI). METHODS: This was a retrospective, consecutive cohort study of CLI patients who underwent infrapopliteal angioplasty at the Vascular and Endovascular Surgery Service of the Hospital do Servidor Público Estadual, São Paulo, between January 2013 and January 2019. The primary outcome variable was the limb salvage rate and wound healing rate. The secondary outcome variables were patency, survival, time free from reintervention, and operative mortality rate. RESULTS: Overall, 95 infrapopliteal endovascular procedures were performed in 95 patients. The initial technical success rate was 100%. The mean ± standard deviation outpatient follow-up time was 775 ± 107.5 days. The analyses were performed at 360 days for wound healing rate and 720 days for limb salvage rates, overall survival, and time freedom from reintervention. According to the angiosome concept, there were 54 patients (56.8%) classified in the direct group and 41 patients (43.2%) in the indirect group. Regarding the WIfI classification subanalysis, there were 22 patients WIfI 0-1 (23.2%) and 73 patients WIfI 2-3 (76.8%). Furthermore, the indirect group had a higher ulcer healing rate than the direct group; however, it was not statistically significant (82.9%; 66.7%%, respectively, P = 0.059). However, the time to heal the ulcer was faster in the WIfI 0-1 groups than WIfI 2-3 groups (164.82 days versus 251,48; P = 0.017). The limb salvage rates at 720 days were similar among indirect and direct Groups (92.6% and 85.4%, P = 0.79). Likewise, the freedom from reintervention rates at 720 days were also similar in Indirect and direct groups (74.6% and 64%, P = 0.23). The survival rates at 720 days were similar in both indirect and direct groups (86.8 and 85.6%, respectively; P = 0.82). The amputation free survival rate at 720 days by the Kaplan-Meier method was 91.3% in the indirect group and 85.9% in the direct group, but with no statistical significance between the groups (P = 0.37) CONCLUSIONS: This study concluded that, in endovascular treatment, the angiosome concept is no longer important to limb salvage rates, nor ulcer/wound healing rates. Moreover, the WIfI classification 0-1 is associated with faster and higher wound/ulcer healing rates than WIfI classification 2-3.

SARS-CoV-2 transmission via aquatic food animal species or their products: A review.

Outbreaks of COVID-19 (coronavirus disease 2019) have been reported in workers in fish farms and fish processing plants arising from person-to-person transmission, raising concerns about aquatic animal food products' safety. A better understanding of such incidents is important for the aquaculture industry's sustainability, particularly with the global trade in fresh and frozen aquatic animal food products where contaminating virus could survive for some time. Despite a plethora of COVID-19-related scientific publications, there is a lack of reports on the risk of contact with aquatic food animal species or their products. This review aimed to examine the potential for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) contamination and the potential transmission via aquatic food animals or their products and wastewater effluents. The extracellular viability of SARS-CoV-2 and how the virus is spread are reviewed, supporting the understanding that contaminated cold-chain food sources may introduce SAR-CoV-2 via food imports although the virus is unlikely to infect humans through consumption of aquatic food animals or their products or drinking water; i.e., SARS-CoV-2 is not a foodborne virus and should not be managed as such but instead through strong, multifaceted public health interventions including physical distancing, rapid contact tracing, and testing, enhanced hand and respiratory hygiene, frequent disinfection of high-touch surfaces, isolation of infected workers and their contacts, as well as enhanced screening protocols for international seafood trade.

[Potentially inappropriate prescribing in older Spanish population according to STOPP/START criteria (STARTREC study)]. / Análisis poblacional de la prescripción potencialmente inadecuada en ancianos según criterios STOPP/START (estudio STARTREC).

OBJECTIVE: Rational prescribing in older people is a priority for health care organizations. The STOPP/START screening tool has been developed to identify potentially inappropriate prescribing (PIP) in individuals. In a primary care setting, STOPP/START can estimate PIP prevalence and related factors at population level. The aim of this study is to measure the prevalence rates of PPI in elderly population using clinical and prescription claim databases. DESIGN: Cross-sectional population study. SETTINGS: Primary Care, Lleida Health Region, Spain. PARTICIPANTS: 45.408 patients 70 years old and over, attended in the primary health care centers at least once the last year. METHODS: 43 STOPP and 12 START criteria are applied to their 2012 clinical and prescription records. Logistic regression models are adjusted to determine PIP association with several factors. RESULTS: 45,408 patients are included. The mean age is 79.7 years, 58% being female. The overall prevalence of PPI is 58.1%. According to STOPP, the most common drugs identified are benzodiazepines, non-steroidal anti-inflammatory drugs and proton pump inhibitors; according to START, osteoporosis treatments, antiplatelet agents, statins, metformin and beta blockers. PIP increases with age and polypharmacy and it is higher in long-term care facilities residents and patients receiving home health care. CONCLUSIONS: In our Health Region, at least 50% of the population aged 70 or older has one or more PIP, according to STOPP/START criteria.

First description of clinical presentation of piscine orthoreovirus (PRV) infections in salmonid aquaculture in Chile and identification of a second genotype (Genotype II) of PRV.

BACKGROUND: Heart and skeletal muscle inflammation (HSMI) is an emerging disease of marine-farmed Atlantic salmon Salmo salar, first recognized in 1999 in Norway, and recently associated with piscine orthoreovirus (PRV) infection. To date, HSMI lesions with presence of PRV have only been described in marine-farmed Atlantic salmon in Norway. A new HSMI-like disease in rainbow trout Oncorhynchus mykiss associated with a PRV-related virus has also been reported in Norway. METHODS: Sampling of Atlantic salmon and coho salmon was done during potential disease outbreaks, targeting lethargic/moribund fish. Fish were necropsied and tissues were taken for histopathologic analysis and testing for PRV by RT-qPCR assay for segment L1 and conventional RT-PCR for PRV segment S1. The PCR products were sequenced and their relationship to PRV strains in GenBank was determined using phylogenetic analysis and nucleotide and amino acid homology comparisons. RESULTS: The Atlantic salmon manifested the classical presentation of HSMI with high PRV virus loads (low Ct values) as described in Norway. The coho salmon with low Ct values had myocarditis but only in the spongy layer, the myositis of red muscle in general was mild, and the hepatic necrosis was severe. Upon phylogenetic analysis of PRV segment S1 sequences, all the Chilean PRV strains from Atlantic salmon grouped as sub-genotype Ib, whereas the Chilean PRV strains from coho salmon were more diversified, grouping in both sub-genotypes Ia and Ib and others forming a distinct new phylogenetic cluster, designated Genotype II that included the Norwegian PRV-related virus. CONCLUSIONS: To our knowledge the present work constitutes the first published report of HSMI lesions with presence of PRV in farmed Atlantic salmon outside of Europe, and the first report of HSMI-like lesions with presence of PRV in coho salmon in Chile. The Chilean PRV strains from coho salmon are more genetically diversified than those from Atlantic salmon, and some form a distinct new phylogenetic cluster, designated Genotype II.

Concept of Angiosome Does Not Affect Limb Salvage in Infrapopliteal Angioplasty.

BACKGROUND: The purpose of this study was to evaluate the importance of the "angiosome" concept in patients with critical limb ischemia treated with infrapopliteal angioplasty, analyzing limb salvage, secondary function, and survival rates between those treated with and without reference to the concept of the angiosome (groups 1 and 2, respectively). METHODS: This was a retrospective, consecutive cohort study that evaluated 95 patients with critical limb ischemia who underwent infrapopliteal angioplasty at the Division of Vascular and Endovascular Surgery, São Paulo State Public Servants' Hospital, Brazil, between January 2009 and January 2013. Of the total 92 patients (109 limbs) who underwent angioplasty, 48 (52.2%) patients were in group 1 and 44 (47.8%) patients were in group 2. RESULTS: There was no difference between groups 1 and 2 in terms of the location, lesion severity, or active infection of the infrapopliteal angioplasty. However, groups 1 and 2 differed in their postoperative ankle-brachial indices, which were 0.95 ± 0.18 and 0.85 ± 0.18, respectively (P = 0.001). The estimates of limb salvage were similar in groups 1 and 2 (87% and 92.3%, respectively, at 360 days; P = 0.241). The analysis of secondary function did not differ between the 2 groups (65.1% and 58.3%, respectively, within 360 days; P = 0.92). Operative mortality was 8.3% in group 1 and 8% in group 2 (P = 0.60), and survival at 360 days was 78.5% in group 1 and 78.3% in group 2 (P = 0.86), which were not significantly different. CONCLUSIONS: In this study, we found no evidence to support revascularization based on the concept of the angiosome in preference to revascularization of the artery that is most amenable to endovascular treatment for limb salvage and secondary function.

Advantages of contrast-enhanced ultrasonography over computed tomography for the detection of persistent type II endoleak after embolization: A case report.

The aim of this case report is to describe the use of contrast-enhanced ultrasonography in the detection of a type II endoleak after prior embolization with Onyx. A 74-year-old male patient with hypertension previously underwent endovascular repair of a 7.1-cm infrarenal aortic aneurysm. CT angiography surveillance revealed a type II endoleak associated with aneurysm sac expansion. Selective transarterial embolization of the endoleak was performed, but it was not possible to detect the persistent endoleak using CT angiography because of image artifacts caused by Onyx. Contrast-enhanced ultrasonography enabled us to detect the persistent endoleak in this patient. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:522-526, 2016.

Genetic analysis and comparative virulence of infectious salmon anemia virus (ISAV) types HPR7a and HPR7b from recent field outbreaks in Chile.

BACKGROUND: Infectious salmon anemia (ISA) is a serious disease of marine farmed Atlantic salmon, Salmo salar L. caused by ISA virus (ISAV). ISAV genomic segments 5 and 6 encode surface glycoproteins hemagglutinin-esterase (HE) and F protein important for the pathogenicity of ISAV. In this study, we describe the genetic characteristics and relationship between ISAV-HPR7a and ISAV-HPR7b strains that caused the ISA outbreaks in Chile in 2013 and 2014, respectively, and the evolution of the ISAV clades since 2009 based on segment 5 and 6 sequences. METHODS: The study material included samples from six ISA cases in Chile. RNA was extracted from salmon tissues and ISAV isolated from cell culture; segments 5 and 6 were amplified by RT-PCR and compared by alignment with ISAV sequences from the GenBank database. RESULTS: ISAV-HPR7a and ISAV-HPR7b belong to the European Genotype I strains only found in Europe and Chile, and in both cases, show high similarity in segments 5 and 6 with identity between 95-96%. Our data confirm the hypothesis that the original virus was introduced to Chile in 1996. Compared to the 2007 ISAV-HPR7b isolate, the 2014 ISAV-HPR7b does not have an insertion in segment 5 and was associated with low mortality, which suggests that ISAV virulence was attenuated by the absence of the insertion in segment 5. In contrast, the highly virulent ISAV-HPR14 from April 2013 outbreak did not have the insertion in segment 5 either. CONCLUSION: Variability in the ISAV virulence markers supports the quasispecies theory that multiple evolution forces are likely to shape ISAV genetic diversity. Our findings provide evidence of continuing evolution of ISAV in the Chilean aquaculture industry.

Whole-genome analysis of piscine reovirus (PRV) shows PRV represents a new genus in family Reoviridae and its genome segment S1 sequences group it into two separate sub-genotypes.

BACKGROUND: Piscine reovirus (PRV) is a newly discovered fish reovirus of anadromous and marine fish ubiquitous among fish in Norwegian salmon farms, and likely the causative agent of heart and skeletal muscle inflammation (HSMI). HSMI is an increasingly economically significant disease in Atlantic salmon (Salmo salar) farms. The nucleotide sequence data available for PRV are limited, and there is no genetic information on this virus outside of Norway and none from wild fish. METHODS: RT-PCR amplification and sequencing were used to obtain the complete viral genome of PRV (10 segments) from western Canada and Chile. The genetic diversity among the PRV strains and their relationship to Norwegian PRV isolates were determined by phylogenetic analyses and sequence identity comparisons. RESULTS: PRV is distantly related to members of the genera Orthoreovirus and Aquareovirus and an unambiguous new genus within the family Reoviridae. The Canadian and Norwegian PRV strains are most divergent in the segment S1 and S4 encoded proteins. Phylogenetic analysis of PRV S1 sequences, for which the largest number of complete sequences from different "isolates" is available, grouped Norwegian PRV strains into a single genotype, Genotype I, with sub-genotypes, Ia and Ib. The Canadian PRV strains matched sub-genotype Ia and Chilean PRV strains matched sub-genotype Ib. CONCLUSIONS: PRV should be considered as a member of a new genus within the family Reoviridae with two major Norwegian sub-genotypes. The Canadian PRV diverged from Norwegian sub-genotype Ia around 2007 ± 1, whereas the Chilean PRV diverged from Norwegian sub-genotype Ib around 2008 ± 1.

Infectious salmon anaemia virus (ISAV) in Chilean Atlantic salmon (Salmo salar) aquaculture: emergence of low pathogenic ISAV-HPR0 and re-emergence of virulent ISAV-HPR∆: HPR3 and HPR14.

ABSTACT: Infectious salmon anaemia (ISA) is a serious disease of marine-farmed Atlantic salmon (Salmo salar) caused by ISA virus (ISAV), which belongs to the genus Isavirus, family Orthomyxoviridae. ISA is caused by virulent ISAV strains with deletions in a highly polymorphic region (HPR) of the hemagglutinin-esterase (HE) protein (designated virulent ISAV-HPR∆). This study shows the historic dynamics of ISAV-HPR∆ and ISAV-HPR0 in Chile, the genetic relationship among ISAV-HPR0 reported worldwide and between ISAV-HPR0 and ISAV-HPR∆ in Chile, and reports the 2013 ISA outbreak in Chile. The first ISA outbreak in Chile occurred from mid-June 2007 to 2010 and involved the virulent ISAV-HPR7b, which was then replaced by a low pathogenic ISAV-HPR0 variant. We analyzed this variant in 66 laboratory-confirmed ISAV-HPR0 cases in Chile in comparison to virulent ISAV-HPR∆ that caused two new ISA outbreaks in April 2013. Multiple alignment and phylogenetic analysis of HE sequences from all ISAV-HPR0 viruses allowed us to identify three genomic clusters, which correlated with three residue patterns of ISAV-HPR0 (360PST362, 360PAN362 and 360PAT362) in HPR. The virus responsible for the 2013 ISAV-HPR∆ cases in Chile belonged to ISAV-HPR3 and ISAV-HPR14, and in phylogenetic analyses, both clustered with the ISAV-HPR0 found in Chile. The ISAV-HPR14 had the ISAV-HPR0 residue pattern 360PAT362, which is the only type of ISAV-HPR0 variant found in Chile. This suggested to us that the 2013 ISAV-HPR∆ re-emerged from ISAV-HPR0 that is enzootic in Chilean salmon aquaculture and were not new introductions of virulent ISAV-HPR∆ to Chile. The clinical presentations and diagnostic evidence of the 2013 ISA cases indicated a mixed infection of ISAV with the ectoparasite Caligus rogercresseyi and the bacterium Piscirickettsia salmonis, which underscores the need for active ISAV surveillance in areas where ISAV-HPR0 is enzootic, to ensure early detection and control of new ISA outbreaks, as it is considered a risk factor. This is the first report of ISA linked directly to the presence of ISAV-HPR0, and provides strong evidence supporting the contention that ISAV-HPR0 shows a strong relationship to virulent ISAV-HPR∆ viruses and the possibility that it could mutate to virulent ISAV-HPR∆.

Evolution and Current Status of Influenza A Virus in Chile: A Review.

The influenza A virus (IAV) poses a significant global threat to public health and food security. Particularly concerning is the avian influenza virus (AIV) subtype H5N1, which has spread from Europe to North and Central/South America. This review presents recent developments in IAV evolution in birds, mammals, and humans in Chile. Chile's encounter with IAV began in 2002, with the highly pathogenic avian influenza (HPAI) H7N3 virus, derived from a unique South American low pathogenic avian influenza (LPAI) virus. In 2016-2017, LPAI H7N6 caused outbreaks in turkey, linked to wild birds in Chile and Bolivia. The pandemic influenza A (H1N1) 2009 (H1N1pdm09) virus in 2009 decreased egg production in turkeys. Since 2012, diverse IAV subtypes have emerged in backyard poultry and pigs. Reassortant AIVs, incorporating genes from both North and South American isolates, have been found in wild birds since 2007. Notably, from December 2022, HPAI H5N1 was detected in wild birds, sea lions, and a human, along Chile's north coast. It was introduced through Atlantic migratory flyways from North America. These findings emphasize the need for enhanced biosecurity on poultry farms and ongoing genomic surveillance to understand and manage AIVs in both wild and domestic bird populations in Chile.

Live and inactivated Piscirickettsia salmonis activated nutritional immunity in Atlantic salmon (Salmo salar).

Nutritional immunity regulates the homeostasis of micronutrients such as iron, manganese, and zinc at the systemic and cellular levels, preventing the invading microorganisms from gaining access and thereby limiting their growth. Therefore, the objective of this study was to evaluate the activation of nutritional immunity in specimens of Atlantic salmon (Salmo salar) that are intraperitoneally stimulated with both live and inactivated Piscirickettsia salmonis. The study used liver tissue and blood/plasma samples on days 3, 7, and 14 post-injections (dpi) for the analysis. Genetic material (DNA) of P. salmonis was detected in the liver tissue of fish stimulated with both live and inactivated P. salmonis at 14 dpi. Additionally, the hematocrit percentage decreased at 3 and 7 dpi in fish stimulated with live P. salmonis, unchanged in fish challenged with inactivated P. salmonis. On the other hand, plasma iron content decreased during the experimental course in fish stimulated with both live and inactivated P. salmonis, although this decrease was statistically significant only at 3 dpi. Regarding the immune-nutritional markers such as tfr1, dmt1, and ireg1 were modulated in the two experimental conditions, compared to zip8, ft-h, and hamp, which were down-regulated in fish stimulated with live and inactivated P. salmonis during the course experimental. Finally, the intracellular iron content in the liver increased at 7 and 14 dpi in fish stimulated with live and inactivated P. salmonis, while the zinc content decreased at 14 dpi under both experimental conditions. However, stimulation with live and inactivated P. salmonis did not alter the manganese content in the fish. The results suggest that nutritional immunity does not distinguish between live and inactivated P. salmonis and elicits a similar immune response. Probably, this immune mechanism would be self-activated with the detection of PAMPs, instead of a sequestration and/or competition of micronutrients by the living microorganism.

Bacterial networks in Atlantic salmon with Piscirickettsiosis.

An unbalanced composition of gut microbiota in fish is hypothesized to play a role in promoting bacterial infections, but the synergistic or antagonistic interactions between bacterial groups in relation to fish health are not well understood. We report that pathogenic species in the Piscirickettsia, Aeromonas, Renibacterium and Tenacibaculum genera were all detected in the digesta and gut mucosa of healthy Atlantic salmon without clinical signs of disease. Although Piscirickettsia salmonis (and other pathogens) occurred in greater frequencies of fish with clinical Salmonid Rickettsial Septicemia (SRS), the relative abundance was about the same as that observed in healthy fish. Remarkably, the SRS-positive fish presented with a generalized mid-gut dysbiosis and positive growth associations between Piscirickettsiaceae and members of other taxonomic families containing known pathogens. The reconstruction of metabolic phenotypes based on the bacterial networks detected in the gut and mucosa indicated the synthesis of Gram-negative virulence factors such as colanic acid and O-antigen were over-represented in SRS positive fish. This evidence indicates that cooperative interactions between organisms of different taxonomic families within localized bacterial networks might promote an opportunity for P. salmonis to cause clinical SRS in the farm environment.

Genomics of Re-Emergent Aeromonas salmonicida in Atlantic Salmon Outbreaks.

Furunculosis, caused by Aeromonas salmonicida, poses a significant threat to both salmonid and non-salmonid fish in diverse aquatic environments. This study explores the genomic intricacies of re-emergent A. salmonicida outbreaks in Atlantic salmon (Salmo salar). Previous clinical cases have exhibited pathological characteristics, such as periorbital hemorrhages and gastrointestinal abnormalities. Genomic sequencing of three Chilean isolates (ASA04, ASA05, and CIBA_5017) and 25 previously described genomes determined the pan-genome, phylogenomics, insertion sequences, and restriction-modification systems. Unique gene families have contributed to an improved understanding of the psychrophilic and mesophilic clades, while phylogenomic analysis has been used to identify mesophilic and psychrophilic strains, thereby further differentiating between typical and atypical psychrophilic isolates. Diverse insertion sequences and restriction-modification patterns have highlighted genomic structural differences, and virulence factor predictions can emphasize exotoxin disparities, especially between psychrophilic and mesophilic strains. Thus, a novel plasmid was characterized which emphasized the role of plasmids in virulence and antibiotic resistance. The analysis of antibiotic resistance factors revealed resistance against various drug classes in Chilean strains. Overall, this study elucidates the genomic dynamics of re-emergent A. salmonicida and provides novel insights into their virulence, antibiotic resistance, and population structure.

Salmo salar Skin and Gill Microbiome during Piscirickettsia salmonis Infection.

Maintaining the high overall health of farmed animals is a central tenant of their well-being and care. Intense animal crowding in aquaculture promotes animal morbidity especially in the absence of straightforward methods for monitoring their health. Here, we used bacterial 16S ribosomal RNA gene sequencing to measure bacterial population dynamics during P. salmonis infection. We observed a complex bacterial community consisting of a previously undescribed core pathobiome. Notably, we detected Aliivibrio wodanis and Tenacibaculum dicentrarchi on the skin ulcers of salmon infected with P. salmonis, while Vibrio spp. were enriched on infected gills. The prevalence of these co-occurring networks indicated that coinfection with other pathogens may enhance P. salmonis pathogenicity.