Bacterial Emboli Research Articles

Anaerobic bacterial metabolism responsive microspheres for bacterial embolization cancer therapy

Anaerobic bacteriolytic cancer therapy, whether delivered locally or systemically, frequently encounters challenges related to limited colonization within hypoxic pockets of central tumors and activation of innate immunity. Herein we have developed trans-arterial bacteria embolization therapy using bacterial embolic microspheres. C. novyi-NT spores loaded calcium alginate embolic microspheres demonstrated C. novyi-NT metabolites-mediated microsphere degradation, releasing vegetative C. novyi-NT bacterial in hypoxic condition. Transcatheter directed bacterial microsphere embolization therapy occludes tumor feeding vessels with infused bacterial embolic microspheres and enhances tumoral hypoxia. Notably, anaerobic bacterial metabolism responsive microsphere-bacterial embolization therapy achieved a complete tumor response with enhanced tumor-specific bacterial delivery and colonization, resulting in cancer cell killing across the entire tumor. In vivo tumor response and immunological profiling revealed that bacterial embolization uniquely enhances anti-cancer response, effectively engaging direct anaerobic bacterial oncolysis and adaptive and innate immune responses in a cooperative manner.

Infective endocarditis with systemic bacterial embolism caused by Staphylococcus aureus in a free-ranging Amami rabbit (Pentalagus furnessi)

The Amami rabbit (Pentalagus furnessi) is found only on the two islands of Amami-Ōshima and Tokunoshima in southwest Japan. It has a primitive appearance and ecology, is an evolutionarily valuable animal and has been assigned to the International Union for Conservation of Nature Red List of Threatened Species. We describe a case with mild purulent wounds on the distal digital skin of both forelimbs and multiple nodular lesions in various organs, including the heart and kidney. Microscopically, the heart lesions were characterized by disruption of the mitral valve and multifocal myocardial necrosis and abscesses due to infection with gram-positive cocci. Similar bacterial infarctions were also found in other organs, including the kidneys. The bacteria were identified as Staphylococcus aureus by immunohistochemical and molecular biological examinations. This first report of infective endocarditis and systemic infarctions caused by S.aureus in an Amami rabbit indicates the importance of monitoring purulent injuries, even if mild, to prevent secondary infections in this species.

Clinical and Pathological Findings Associated with Mycobacteriosis in Captive Syngnathids

Mycobacteriosis is an important disease that affects captive and wild aquatic fish. Syngnathids are susceptible to infection by non-tuberculous mycobacteria. The aim of this study was to describe clinical signs, and macroscopic and histological lesions in 25 syngnathids and the molecular characterization of the causative mycobacteria. Clinical presentation ranged from sudden death to non-specific signs, including anorexia, poor body condition, weight loss and marked dyspnea with increased respiratory effort and rate. Gross lesions were mostly ulcers on the tail and small white nodules in the liver, coelomic cavity and inside the eye. The most affected organs were gills, liver, intestine and coelomic mesentery. Microscopic lesions consisted of areas of multifocal to diffuse granulomatous inflammation and bacterial emboli with numerous intralesional acid-fast bacilli. Epithelioid cells, multinucleated giant cells, lymphocytes and fibrous connective tissue, which are commonly observed in granulomatous inflammation, were not observed here. In the real-time PCR, M. fortuitum, M. chelonae and M. marinum common primers, Mycobacterium spp. were detected in 4, 7 and 14 individuals, respectively. In addition, this is the first description of mycobacteriosis found in Syngnathus acus.

Severe Klebsiella pneumoniae pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism: A case report

Klebsiella pneumoniae (K. pneumoniae) is a clinically common Gram-negative bacillus that can cause community- and hospital-acquired infections and lead to pneumonia, liver abscesses, bloodstream infections, and other infectious diseases; however, severe pneumonia caused by hypervirulent K. pneumoniae (hvKp) complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism is rarely seen in the clinical setting and has not been reported in the literature. A 51-year-old man was hospitalized with fever and dyspnea. Persistent mild pain in the middle and upper abdomen began at dawn on the 3rd day following admission and developed into persistent severe pain in the left upper abdomen 8 h later. Based on chest computed tomography (CT), bronchoscopy, bronchoalveolar lavage fluid metagenomic next-generation sequencing, abdominal aortic CT angiography (CTA), and culture of the superior mesenteric artery embolus, adult community-acquired severe hvKp pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism was diagnosed. Notably, he recovered and was discharged from the hospital after receiving effective meropenem anti-infection, endovascular contact thrombolytic, and systemic anticoagulant therapies and undergoing percutaneous thrombus aspiration. Ten days later, the patient returned to the hospital for abdominal CTA examination, which indicated blocked initial common pathway of the celiac trunk and superior mesenteric artery, and local stenosis. Therefore, celiac trunk artery stenting was performed in Chongqing Hospital, and postoperative recovery was good. We report a case of hvKp severe pneumonia complicated by acute intra-abdominal multiple arterial thrombosis and bacterial embolism and suggest that clinicians should consider the possibility of a Gram-negative bacillus infection and conduct effective pathogen detection in a timely fashion when managing patients with severe community-acquired pneumonia before obtaining bacteriologic and drug sensitivity results. At the same time, when patients have severe pulmonary infection complicated by severe abdominal pain, an acute mesenteric artery embolism should be considered to avoid delays in treatment.

The Role of Pectobacterium atrosepticum Exopolysaccharides in Plant–Pathogen Interactions

The phytopathogenic bacterium Pectobacterium atrosepticum (Pba), one of the members of the soft rot Pectobacteriaceae, forms biofilm-like structures known as bacterial emboli when colonizing the primary xylem vessels of the host plants. The initial extracellular matrix of the bacterial emboli is composed of the host plant’s pectic polysaccharides, which are gradually substituted by the Pba-produced exopolysaccharides (Pba EPS) as the bacterial emboli “mature”. No information about the properties of Pba EPS and their possible roles in Pba-plant interactions has so far been obtained. We have shown that Pba EPS possess physical properties that can promote the maintenance of the structural integrity of bacterial emboli. These polymers increase the viscosity of liquids and form large supramolecular aggregates. The formation of Pba EPS aggregates is provided (at least partly) by the acetyl groups of the Pba EPS molecules. Besides, Pba EPS scavenge reactive oxygen species (ROS), the accumulation of which is known to be associated with the formation of bacterial emboli. In addition, Pba EPS act as suppressors of the quantitative immunity of plants, repressing PAMP-induced reactions; this property is partly lost in the deacetylated form of Pba EPS. Overall, our study shows that Pba EPS play structural, protective, and immunosuppressive roles during Pba–plant interactions and thus should be considered as virulence factors of these bacteria.

The Modification of Plant Cell Wall Polysaccharides in Potato Plants during Pectobacterium atrosepticum-Caused Infection

Our study is the first to consider the changes in the entire set of matrix plant cell wall (PCW) polysaccharides in the course of a plant infectious disease. We compared the molecular weight distribution, monosaccharide content, and the epitope distribution of pectic compounds and cross-linking glycans in non-infected potato plants and plants infected with Pectobacterium atrosepticum at the initial and advanced stages of plant colonization by the pathogen. To predict the gene products involved in the modification of the PCW polysaccharide skeleton during the infection, the expression profiles of potato and P. atrosepticum PCW-related genes were analyzed by RNA-Seq along with phylogenetic analysis. The assemblage of P. atrosepticum biofilm-like structures—the bacterial emboli—and the accumulation of specific fragments of pectic compounds that prime the formation of these structures were demonstrated within potato plants (a natural host of P. atrosepticum). Collenchyma was shown to be the most “vulnerable” tissue to P. atrosepticum among the potato stem tissues. The infection caused by the representative of the Soft Rot Pectobacteriaceae was shown to affect not only pectic compounds but also cross-linking glycans; the content of the latter was increased in the infected plants compared to the non-infected ones.

Systemic Erysipelothrix rhusiopathiae in seven free-ranging delphinids stranded in England and Wales.

Microbiology records for 1127 cetaceans stranded on English and Welsh beaches and examined at the Institute of Zoology between 1990 and 2019 were reviewed to identify cases of Erysipelothrix rhusiopathiae, an uncommon but potentially fatal zoonotic pathogen. Once cases were identified, prevalence was calculated, corresponding postmortem reports were reviewed, common gross and histopathological findings were identified, and antibiotic susceptibilities were determined. Overall prevalence for E. rhusiopathiae was 0.62% (7/1127; 95% CI: 0.30-1.28%). It was isolated from 3 bottlenose dolphins Tursiops truncatus, 3 harbor porpoises Phocoena phocoena, and 1 short-beaked common dolphin Delphinus delphis, with a prevalence of 21.4% (3/14; 95% CI: 7.6-47.9%), 0.39% (3/779; 95% CI: 0.13-1.13%), and 0.47% (1/212; 95% CI: 0.08-2.62%) for each species, respectively. E. rhusiopathiae resulted in septicemia in all cases from which it was isolated. Gross necropsy findings included pulmonary edema (5/7), hemorrhage (5/7) and/or congestion of various organs (4/7), and serosanguineous effusion (3/7; pericardial: 3/7, pleural: 2/6, abdominal: 2/6). Congestion (5/5), bacterial emboli (4/5), and hemorrhage (4/5) were commonly observed on histopathology, and acute renal tubular injury (2/5) and pulmonary edema (2/5) were occasionally observed. Routine bacterial cultures were vital in identifying E. rhusiopathiae, since gross lesions were often subtle and nonspecific. The liver, kidney, and brain were key organs from which E. rhusiopathiae was consistently isolated. Antibiotic resistance was uncommon and was only observed for amikacin and trimethoprim sulfonamide. Penicillins were consistently effective, along with fluoroquinolones, macrolides, clindamycin, cephalexin, and oxytetracycline.

Clinical analysis of 14 infective endocarditis in patients with obstructive hypertrophic cardiomyopathy

Objective: This observational study was aimed to analyze the clinical characteristics of infective endocarditis (IE) in patients with hypertrophic cardiomyopathy (HCM). Methods: A total of 668 patients with IE, and 7 427 patients with HCM were treated in Fuwai Hospital from August 2006 to December 2018. Among them, 14 patients were diagnosed with HCM and IE. The clinical characteristics of these patients including clinical manifestations, pathogen distribution, echocardiography features, in-hospital treatment and outcomes were analyzed retrospectively. Results: The proportion of HCM patients with IE was 0.19%,with the estimated incidence of 0.15/1 000 person-years in HCM patients. Of the 14 patients, 11 patients were male. The most common clinical manifestations were fever and heart murmur, and the main complications were heart failure (12/14) and bacterial embolism (8/14). There were 8 cases (8/14) with positive blood culture, and all causative bacteria were gram positive coccus, in which 5/8 were Streptococcus. The median interventricular septum thickness was (21.2±2.7) mm, and left ventricular outflow obstruction was severe based on echocardiography (Echo) examination. The Echo showed that vegetation was found in all 14 patients and most of the vegetation attached at the anterior leaflet of mitral valve (12/14). The proportions of patients with circulatory embolism (8/14) and valve lesions (12/14) were relatively high. Most cases (10/14) were cured, especially those underwent cardiac surgery (8 cases). The rest 4 cases died with 2 in hospital and 2 after auto-discharge. Conclusions: HCM patients complicated with IE are rare. Septic embolization and valve lesions are common in these patients. IE patients with HCM might have a poor prognosis compared to those without HCM and should receive cardiac surgery as early as possible.

Causes of death in growing-finishing pigs in two technified farms in southern Brazil

ABSTRACT: The aim of this study was to investigate the main causes of death in growing-finishing pigs in southern Brazil. During a one-year period (from 2018 to 2019), two industrial pig herds (18 and 20 thousand pigs each farm) in southern Brazil were monitored along the four seasons of the year (12 days per season on each farm), in order to perform necropsies of all pigs that died in that period. The two farms had an average monthly mortality rate ranging from 0.94 to 3.93% in the evaluated months. At necropsy, tissues were collected, fixed in 10% formalin solution and processed routinely for histopathological examination. When necessary, samples were sent for bacterial culture and PCR to identify etiologic agents. A total of 601 necropsies were performed, with 94.9% of conclusive diagnoses. Infectious diseases corresponded to 64.4% of conclusive diagnosis and non-infectious diseases to 35.6%. The most prevalent causes of death were: pneumonia (33%), gastric ulcers (15.4%), circovirosis (9.9%), systemic bacterial embolism (5.4%), polyserositis (4.4%), dilated cardiomyopathy and torsion of abdominal organs (4.3% each), and bacterial pericarditis (3.4%). Regarding pneumonias (199/601), the main agents identified in these cases were Pasteurella multocida, Influenza A virus and Mycoplasma hyopneumoniae, mainly in associations.

Molecular Imaging of Cardiovascular Device Infection: Targeting the Bacteria or the Host–Pathogen Immune Response?

Rapid and accurate diagnosis of cardiovascular device infection remains a challenge in the clinic. Anatomic imaging tools such as echocardiography and cardiac CT or CT angiography are the first-line modalities for clinically suspected endocarditis given their ability to detect vegetation and perivalvular complications. Accumulating data suggest that functional imaging with 18F-FDG PET/CT has unique merits over anatomic imaging and could potentially diagnose early cardiac device infection before morphologic damage ensues and identify infection sources or bacterial emboli in the rest of the body. Although an abnormal finding on 18F-FDG PET/CT was added to the 2015 guidelines of the European Society of Cardiology as a major criterion for the diagnosis of device-related and prosthetic valve endocarditis, that addition has not been incorporated in the U.S. guidelines. Beyond these clinically available imaging tools, attempts have been made to develop bacteria-targeting tracers for specific infection imaging, which include tracers of bacterial maltodextrin transporter, bacterial thymidine kinase, antibiotics, antimicrobial peptides, bacterial antibodies, bacteriophages, and bacterial DNA/RNA hybrid nucleotide oligomers. Most of the tracers have been studied only in experimental animals, except for radiolabeled antibiotics, which have been examined in humans without success in clinical translation for infection imaging. In this article, we compare the roles of anatomic and functional imaging for cardiac device infection and discuss the pros and cons of 18F-FDG and bacteria-targeting tracers. While anticipating continued investigations for bacteria-specific tracers in the future, we recommend that 18F-FDG PET/CT, which represents the host-pathogen immune response to infection, be used clinically for identifying cardiovascular device infection.

Group A streptococcus endocarditis in children: 2 cases and a review of the literature

BackgroundInfective endocarditis (IE) is defined as endocarditis caused by microorganisms (bacteria or fungi) involving either the heart or great vessels. The clinical course of IE can be complicated by cardiac dysfunction and bacterial embolization to virtually any organ. Staphylococcus aureus and viridans group streptococci are the most common causative organisms, whereas group A Streptococcus (GAS) is less common. Although some GAS serotypes have been associated with severe disease, there are few reports of IE associated with GAS serotypes. Here, we report two cases of GAS endocarditis and review the associated literature.Case presentationsPatient 1 was a previously healthy 14-year-old girl who developed bacteremia and disseminated intravascular coagulation secondary to left foot cellulitis. She was administered intravenous antibiotics. Two of three blood cultures grew Streptococcus pyogenes (T6 M6, emm6.104). Three days later, a new systolic ejection murmur was heard and echocardiography showed mitral regurgitation with mitral valve vegetation. Because of the resultant severity of the mitral regurgitation, she underwent mitral valve repair after 10 weeks of antibiotic treatment. Patient 2 was a 17-month old boy who presented with a fever. He had a history of spontaneous closure of a ventricular septal defect (VSD). He was started on intravenous antibiotics for possible bacteremia. Two consecutive blood cultures with an interval of more than 12 h grew S. pyogenes (T4 M4, emm4.0). Five days later, echocardiography showed vegetation on a membranous ventricular septal aneurysm. The patient responded well to antibiotics, and recovered fully with no complications.ConclusionsAlthough both patients developed GAS endocarditis, patient 1 did not have any predisposing conditions for IE, and patient 2 had a only a low-risk predisposing condition, a VSD that had closed spontaneously at five months of age. We found twelve reports in the literature of GAS endocarditis with information on serotypes. All patients in these reports had GAS endocarditis caused by serotypes generally associated with milder infections, but no specific risk trends were identified. A greater accumulation of cases is necessary to more clearly elucidate the association between GAS IE and specific serotypes.

654. Biofilm Forming Methicillin-Resistant Staphylococcus aureus Induces Renal Deterioration and Severe Virulence in a Mouse Bacteraemic Model

BackgroundMethicillin-resistant S. aureus (MRSA), a responsible bacterium to nosocomial infection, induces biofilm (BF) infection. We previously indicated that individual MRSA manifests a various BF forming ability, and high BF formers infused in the blood can survive even after phagocytosis by Kupffer cells. In this study, we advance the research to examine the development of BF formation in tissues during 96 h after infusion.MethodsOut of 172 clinical isolates of MRSA, highest BF former (H-BF) and lowest BF former (L-BF) were used. Bacteria were infused via tail vain. Mice were checked for general status and bacterial distribution in the organs (liver, lung, spleen and kidney) at histological and bacteriological levels. BF was also histologically detected by stains for polysaccharides.ResultsAfter MRSA infusion, general status in L-BF maintained in normal range during the study, H-BF however revealed poor status, which was aggravated in accordance with time. After infusion, bacteria started to reappear in the blood after 24 h of the study, and, on 96 hour, H-BF exhibited an eight times greater extent than L-BF. Bacterial colonies were formed in the kidney in both of the groups, and colonies in the liver were only noted in H-BF. In the kidney, CFU in both of the groups increased by time, and its number on 96 h was significant greater in H-BF than L-BF. In H-BF, bacterial embolism accompanied with BF was histologically found in medullary capillaries in the kidney on 24 hours. Growing BF aggressively penetrated into the stroma and tubular lumen forming a wedge-like renal necrosis.ConclusionThese results indicate that BF forming MRSA in the blood preferably settle and form BF in the kidney in mice, which leads to a biofilm infection and a severe deterioration. Although the mechanisms of kidney specific lesions formed by MRSA are still unclear, BF forming ability in MRSA might be crucially important for bacterial virulence in vivo.Disclosures All authors: No reported disclosures.

Transcriptome profiling helps to identify potential and true molecular switches of stealth to brute force behavior in Pectobacterium atrosepticum during systemic colonization of tobacco plants

In the present study, we have monitored the process of systemic plant colonization by the plant pathogenic bacterium Pectobacterium atrosepticum (Pba) using RNA-Seq analysis in order to compare bacterial traits under in planta and in vitro conditions and to reveal potential players that participate in switching from stealth to brute force strategy of the pathogen. Two stages of tobacco plant colonization have been assayed: i) the initial one associated with visually symptomless spread of bacteria throughout the host body via primary xylem vessels where bacterial emboli were formed (stealth strategy), and ii) the advanced stage coupled with an extensive colonization of core parenchyma and manifestation of soft rot symptoms (brute force strategy). Plant-inducible genes in Pba and potential players switching the pathogen’s behavior were revealed. Genes from the cfa locus responsible for the production of coronafacic acid displayed the strongest induction in the asymptomatic zone relative to the symptomatic one and were shown experimentally to act as the true strategy “switchers” of Pba behavior in planta. Surprisingly, cfa genes appeared to be unnecessary for establishment of the asymptomatic stage of plant colonization but were required for the transition to soft-rot-associated symptomatic stage coupled with over-induction of jasmonate-mediated pathway in the plant.

Immunobiological and morphofunctional indicators with dysbacteriosis of the intestine of rabbits

The article presents results of research of dynamics of morphological, biochemical, haematological and immunological parameters when changing the quantity and species of microorganisms of intestinal microbiocenosis of the rabbits. With the dominance of pathogenic bacteria in rabbit intestinal microbiocenoses, the titer of bifidumbacteria was 10-5-10-4, a decrease in the number of lactobacilli, an increase in the number of enterobacteria, a correlation between the colonization index and the degree of adhesion of bacteria was revealed; an increase in the total number of leukocytes, lymphocytes, erythrocytes, hematocrit, alanine aminotransferase level, aspartate aminotransferase, lactate dehydrogenase, total bilirubin, -amylase, albumin, alkaline phosphatase, T-killer level, NK cells, concentration of C-reactive protein. We observed a decrease in the concentration of hemoglobin, monocytes, total protein level, T-lymphocytes, T-helpers, B-lymphocytes, phagocytic index, phagocytic activity of leukocytes, NST-spontaneous, NST-stimulated. Dynamics of morphological indicators was characterized by a disorder of the circulation of organs, a predominance of dystrophic and necrotic processes in the tissues and organs of the cardiovascular, respiratory, digestive, excretory system. Infiltration with mononuclear and segmented leukocytes was noted, diffuse lymphoid proliferation of the mucous membranes of the organs, hyperemia, edema, multiple hemorrhages, accumulation of hemorrhagic exudate in the lumen of the respiratory, digestive and urogenital tracts. Observed catarrhal-hemorrhagic inflammation of the gastrointestinal tract; mucous membrane of the stomach, small and large intestines edematic, hyperemic, with hemorrhages, covered with mucus, fibrinous films, with necrotic areas. The signs of acute diffuse interstitial nephritis, characterized by proliferation of connective tissue cells with a predominance of lipoblast and epithelioid cells, are revealed. In the presence of bacterial cells in the lumen of the tubules, the parenchyma of the cortical and medullar layers was marked by microabscesses. Accidental transformation of the thymus was observed, characterized by signs of a circulatory disorder, a decrease in the area of the cortex, the formation of cysts; signs of diffuse hyperplasia of the spleen with necrobiotic changes in the foci of proliferation, reduction of the area of lymphoid follicles, expansion of the area occupied by the red pulp of follicles, hyperplasia of follicles of white pulp with foci of necrosis. Identified multiple bacterial embolism of blood vessels, developed signs of hemorrhagic Diathesis, watched the development of sign infiltrative itch processes.

Pectobacterium atrosepticum exopolysaccharides: identification, molecular structure, formation under stress and in planta conditions.

In the present study, we identified exopolysaccharides of the harmful phytopathogenic bacterium Pectobacterium atrosepticum SCRI1043 and characterized the molecular structure of these polymers. The synthesis of the target polysaccharides was shown to be induced under starvation conditions. Moreover, intensive accumulation of exopolysaccharides occurred during the colonization by bacteria of the xylem vessels of infected plants, where microorganisms formed specific 3D "multicellular" structures-bacterial emboli. Thus, the identified polymers are likely to be involved in the adaptation and virulence of bacteria of Pectobacterium genus.

PATHOLOGICAL AND BACTERIOLOGICAL STUDIES ON SOME RECORDED INTERNAL ABSCESSES IN SLAUGHTERED CATTLE

Internal microbial infection may lead to abscesses formation in cattle. This study was conducted on 1500 slaughtered cattle from Mansoura abattoir and Damietta local dairy farms to screen out the presence of internal abscesses. Of 1500 slaughtered cattle, 160 animals (10.67%) were affected with lung abscesses (n=140) (87.5%), lung abscesses with tonsillar involvement (n=3) (1.87%), liver abscesses (n=15) (9.37%), bacterial endocarditis with systemic lodgment of bacterial emboli (n=1) (0.62%) and spinal epidural abscess (n=1) (0.62%). Younger animals less than 1 year were more susceptible. A variety of bacterial species including, Pasteurella multocida (P. multocida) 132 (70.58%), Arcanobacterium pyogenes (A. pyogenes) 30 (16.04%), Pseudomonas aeruginosa 12 (6.41%), Staphylococcus aureus 8 (4.27%) and Streptococcus spp. 5 (2.67%) were isolated. The histopathological changes associated with the internal abscesses formation were described in this study. In conclusion, the frequency of bovine abscesses was the highest in lungs. The most common isolate was P. multocida followed by A. pyogenes.

Pathogen-induced conditioning of the primary xylem vessels - a prerequisite for the formation of bacterial emboli by Pectobacterium atrosepticum.

Representatives of Pectobacterium genus are some of the most harmful phytopathogens in the world. In the present study, we have elucidated novel aspects of plant-Pectobacterium atrosepticum interactions. This bacterium was recently demonstrated to form specific 'multicellular' structures - bacterial emboli in the xylem vessels of infected plants. In our work, we showed that the process of formation of these structures includes the pathogen-induced reactions of the plant. The colonisation of the plant by P.atrosepticum is coupled with the release of a pectic polysaccharide, rhamnogalacturonan I, into the vessel lumen from the plant cell wall. This polysaccharide gives rise to a gel that serves as a matrix for bacterial emboli. P.atrosepticum-caused infection involves an increase of reactive oxygen species (ROS) levels in the vessels, creating the conditions for the scission of polysaccharides and modification of plant cell wall composition. Both the release of rhamnogalacturonan I and the increase in ROS precede colonisation of the vessels by bacteria and occur only in the primary xylem vessels, the same as the subsequent formation of bacterial emboli. Since the appearance of rhamnogalacturonan I and increase in ROS levels do not hamper the bacterial cells and form a basis for the assembly of bacterial emboli, these reactions may be regarded as part of the susceptible response of the plant. Bacterial emboli thus represent the products of host-pathogen integration, since the formation of these structures requires the action of both partners.

Fatal Erysipelothrix rhusiopathiae septicemia in two Atlantic dolphins (Stenella frontalis and Tursiops truncatus)

We describe gross, histopathologic, ultrastructural, immunohistochemical, and microbiologic features of acute septicemia by Erysipelothrix rhusiopathiae in an Atlantic spotted dolphin Stenella frontalis and an Atlantic bottlenose dolphin Tursiops truncatus. Generalized lymphadenomegaly and widespread hemorrhages were the most consistent macroscopic findings. Tricavitary effusion and icterus were noted in one individual. Histologically, all organs examined showed numerous variably sized bacillary bacterial emboli (Gram-positive; Ziehl-Neelsen-negative), typically associated with systemic congestion, edema, hemorrhages, and fibrinocellular thrombi. These bacteria were frequently intravascular, either extracellular or intramonocytic/macrophagic, and to a lesser extent, free within the interstitium of parenchymal organs. In both cases, microbiological analysis yielded E. rhusiopathiae. A primary anti-E. rhusiopathiae antibody created in mice from one of the strains isolated allowed positive immunohistochemical detection. Electron microscopy and dual immunohistochemistry with lysozyme and MAC387 antibodies confirmed the intramacrophagic location of the bacilli. E. rhusiopathiae, a known multispecies and zoonotic agent, should be considered as a potential etiologic agent in septicemia cases in free-ranging individuals of these dolphin species.

Mycotic aneurysm detection rates with cerebral angiography in patients with infective endocarditis

BackgroundCerebral angiography remains the gold standard for the detection of mycotic aneurysms, and it has been estimated that ruptured mycotic aneurysms result in 5% of the neurological complications of patients...

Lethal cervical abscess following bisphosphonate related osteonecrosis of the jaw

ContextBisphosphonates are common drugs used in the management of bone metabolic diseases. Because of their recently increased use, their adverse effects, especially bisphosphonate-related osteonecrosis of the jaw (BRONJ), are monitored more frequently. BRONJ is a critical challenge in craniofacial surgery and is difficult to treat. Its occurrence is either spontaneous or follows dentoalveolar surgery. Typical complications of BRONJ are painful exposed bone, pathological fractures, extra-oral fistula, and local infections. ObjectiveThe aim of this paper is to report a rare case of bacterial embolism in the internal jugular vein after a BRONJ-induced submandibular abscess resulting in bacterial sepsis, multi-organ failure syndrome, and death. Case illustrationA 59-year-old female patient developed severe BRONJ (stage II) with recurrent abscesses after oral osteoporosis therapy with alendronic acid. A subsequent submandibular abscess led to bacterial embolism of the left internal jugular vein, causing sepsis and death. DiscussionPrevention, early detection and management of BRONJ remain a crucial challenge in craniofacial clinical practice. Despite several therapeutic approaches described in the current literature, none have undergone bedside application. ConclusionConsidering this report of death after recurrent abscesses following BRONJ, the use of bisphosphonates should be carefully monitored in order to prevent such severe complications.