Nontyphoidal cardiac salmonellosis: two case reports and a review of the literature

An Update on Myocarditis in Forensic Pathology

In forensic medicine, myocarditis is a complicated topic in the context of sudden death and medical malpractice. A good knowledge of the etiopathology, histopathology, and available literature are both indispensable and essential for the correct management and evaluation of the causal link. Some agents, which are rarely lethal for humans, are not necessarily related to death from myocarditis, even if an infection in other organs such as the gastrointestinal tract is documented. The diagnosis of the causes of death is often difficult and confusing. In some cases, the hypothetical diagnosis of myocarditis as the cause of death is formulated by deduction, causing error and misleading the correct temporal evaluation of pathological events. We reviewed the literature realizing that histomorphological data are scarce and often poorly documented. Only after COVID-19 have the histomorphological aspects of myocarditis been better documented. This is due to poor autopsy practice and poor accuracy in identifying the specific histotype of myocarditis with identification of the responsible agent. We believe that four points are essential for a better understanding and complete diagnosis of the disease: (1) clinical classification of myocarditis; (2) etiological classification of myocarditis; (3) pathophysiology of viral and bacterial infections with host response; and (4) histopathological diagnosis with precise identification of the histotype and pathogen. In the review we provide histological images from authoritative scientific references with the aim of providing useful information and food for thought to readers.

Non-typhoidal Salmonella enteritidis prosthetic valve endocarditis

In this case, we present a rare cause of prosthetic valve endocarditis. A man in his 80s presented to the emergency department with fever and diarrhoea. The patient underwent a transcatheter aortic valve replacement 17 years earlier. A negative PCR result in faeces for Salmonella and positive blood cultures with Salmonella gave rise to the suspicion of an intravascular Salmonella infection, which was confirmed with a positron emission tomography. Due to the low prevalence of Salmonella endocarditis, there is no consensus on the most effective treatment. Guidelines recommend early surgery and long-term antimicrobial treatment in endocarditis with Gram-negative bacteria. In this case, surgery was not deemed feasible given the patient his advanced age and multiple comorbidities. Despite treatment with intravenous antibiotics, the patient succumbed to progression of endocarditis 37 days after admission.

Salmonella Bacteremia in an Older Patient With No Specific Entry: A Case Report

In this case report, we describe a rare case of non-typhoidal Salmonella bacteremia in an 87-year-old woman with no apparent history of daily Salmonella exposure. The patient presented with fever, body discomfort, and diarrhea. Medical examinations ruled out usual sources of Salmonella, including raw food consumption and pet contact. Her medical history included postoperative sigmoid colon cancer, left breast cancer, and other ailments. Although Salmonella infection typically stems from oral intake, this case suggests that bacterial translocation from the gastrointestinal tract could be the primary cause, potentially exacerbated by the patient's age and medical history. Another hypothesis is an ascending infection from diarrhea to the urinary tract, which might have led to pyelonephritis and subsequent bacteremia. This case highlights the importance of recognizing the potential for severe infections such as sepsis in older individuals presenting with diverse symptoms. Therefore, this case further underscores the need for heightened clinical vigilance, especially in community hospitals, to ensure timely and appropriate management of such severe conditions in the older population.

High-throughput sequencing-based metagenomic and transcriptomic analysis of intestine in piglets infected with salmonella

Salmonella enterica serovar Typhimurium isolate HJL777 is a virulent bacterial strain in pigs. The high rate of salmonella infection are at high risk of non-typhoidal salmonella gastroenteritis development. Salmonellosis is most common in young pigs. We investigated changes in gut microbiota and biological function in piglets infected with salmonella via analysis of rectal fecal metagenome and intestinal transcriptome using 16S rRNA and RNA sequencing. We identified a decrease in Bacteroides and increase in harmful bacteria such as Spirochaetes and Proteobacteria by microbial community analysis. We predicted that reduction of Bacteroides by salmonella infection causes proliferation of salmonella and harmful bacteria that can cause an intestinal inflammatory response. Functional profiling of microbial communities in piglets with salmonella infection showed increasing lipid metabolism associated with proliferation of harmful bacteria and inflammatory responses. Transcriptome analysis identified 31 differentially expressed genes. Using gene ontology and Innate Immune Database analysis, we identified that BGN, DCN, ZFPM2 and BPI genes were involved in extracellular and immune mechanisms, specifically salmonella adhesion to host cells and inflammatory responses during infection. We confirmed alterations in gut microbiota and biological function during salmonella infection in piglets. Our findings will help prevent disease and improve productivity in the swine industry.

Massive purulent pericardial effusion with ultrasound features of tamponade secondary to non-typhoid Salmonella infection

Purulent pericardial effusions are rare and represent the most severe form of bacterial pericarditis. The authors present a case of a male in his 40s with a massive purulent pericardial effusion due to non-typhoid Salmonella, who presented with ultrasound features of a cardiac tamponade. Invasive non-typhoid Salmonella cardiac infection is a rare but important consideration in immunocompromised individuals. This of particular concern in sub-Saharan Africa, where there is a high prevalence of HIV-infected individuals.

Community-associated Methicillin-resistant Staphylococcus aureus pericarditis in an immunocompetent patient

Background

Pericarditis caused by Methicillin-resistant Staphylococcus aureus (MRSA) is a rare infection, often seen in patients with chronic kidney disease, immunosuppression, or previous pericardial disease. The presentation can be dramatic with acute illness leading to septic and/or obstructive shock due to pericardial tamponade. Occasionally disease can have a more protracted, indolent, subacute clinical course.

Case report

We report a case of a 57-year-old male patient with a previous history of smoking and moderate alcohol use who presented with progressive dyspnea and cough. He was found to have a disseminated MRSA infection with pericarditis complicated by pericardial tamponade. Urgent pericardiocentesis yielded 1.1 liters of purulent fluid that grew MRSA. MRSA was also isolated from the blood and pleural fluid. The patient underwent left thoracotomy, decortication, and pericardial window and completed 3 weeks of intravenous vancomycin therapy, concluding in an excellent outcome.

Conclusion

Bacterial pericarditis is an exceptionally rare form of pericarditis which been traditionally associated with chronic medical conditions requiring a prolonged healthcare stay. However, it has lately been observed in healthy individuals with social habits such as smoking and alcohol consumption. Bacterial pericarditis must be recognized in a timely fashion and managed aggressively to prevent a devastating outcome. A multidisciplinary approach is advised, which includes a combination of pericardial drainage and aggressive antibiotic therapy. Such treatment often yields a positive outcome and good long-term prognosis.

An Extremely Rare Case of Upper Thoracic Salmonella Infection

Background

Vertebral osteomyelitis is rare. Finding the right etiological agent is important to administer antibiotic regimen accordingly. The occurrence of this disease in endemic countries raises the susceptibility of a more common infection such as tuberculosis and pyogenic bacteria. Salmonella spp. infection is also common in endemic countries; however, extra-intestinal manifestation is very rare.

Methods

We present an extremely rare case of salmonella vertebral osteomyelitis (SVO) in the upper thoracic vertebrae of a 64-year-old patient with history of cardiac surgery and other pre-existing comorbidities. SVO was treated by antibiotics, surgical debridement and spinal stabilization.

Results

Three weeks after surgery and intravenous antibiotics, the patient recovered and was discharged without fever and back pain, with excellent motoric improvement.

Conclusion

Salmonella infection must be considered to be one of possible etiological agents in patients with suggestive spondylitis in emerging countries, especially in those with comorbidities.

Acute myopericarditis caused by Salmonella enterica serovar Enteritidis: a case report

BACKGROUND

Acute myopericarditis can be caused by a myriad of infectious and non-infectious aetiologies, however, it is often considered to be due to self-limiting viral infection. Salmonella spp. myopericarditis is rare and the few cases in the literature suggest significant associated morbidity and mortality.

CASE SUMMARY

A 44-year-old man presented with fever, dyspnoea, and chest pain. He was found to have a large pericardial effusion with clinical signs of tamponade and sepsis. Therapeutic pericardiocentesis was performed and ceftriaxone and levofloxacin were administered. Fully sensitive Salmonella enterica serovar Enteritidis (S. Enteritidis) was isolated in his pericardial fluid and he made a full recovery after a 4-week course of ciprofloxacin. A new diagnosis of type 2 diabetes mellitus was made on admission. A follow-up cardiac magnetic resonance (CMR) scan was suggestive of myocarditis which was unexpected given a normal Troponin T level on presentation.

DISCUSSION

We report a rare case of S. Enteritidis myopericarditis. Our case is notable as the patient was immunocompetent apart from newly diagnosed diabetes. This case highlights the value of CMR imaging in assessing for myocarditis and ventricular function.

Salmonella typhimurium myopericarditis: A case report and review of literature

BACKGROUND

Non-typhoidal salmonella (NTS) is a rare, but well-established cause of myopericarditis. Presenting symptoms may be varied, however often revolve around the dual presentation of both myopericarditis and infectious diarrhoea. Given the rarity of NTS related myopericarditis, we conducted a systematic review of the literature, identifying 41 previously reported cases.

CASE SUMMARY

We present the case of an otherwise healthy 39-year old male, presenting with chest pain in the setting of documented Salmonella typhimurium infection. After further investigation with echocardiogram and laboratory blood tests, a diagnosis of NTS associated myopericarditis was made, and the patient received antibiotic treatment with an excellent clinical outcome. Overall, myopericarditis is rare in NTS. Although treatment for myopericarditis has not been well established, there are guidelines for the treatment of NTS infection. In our review, we found that the majority of NTS cases has been pericarditis (27/42, 64.3%), with an average age of 48.3 years, and 71.4% being male. The average mortality across all cases was 31%.

CONCLUSION

Myopericarditis is a rare, but potentially serious complication of NTS infection, associated with an increased morbidity and mortality.

Evaluation of a Salmonella Strain Isolated from Honeybee Gut as a Potential Live Oral Vaccine Against Lethal Infection of Salmonella Typhimurium

In this research, Salmonella species were isolated from the animal, insect and human enteric sources in Faisalabad, Punjab, Pakistan. These species were characterized by different microbiological and molecular techniques including polymerase chain reaction (PCR) by amplification of the 16S rRNA gene. Furthermore, sequencing of the amplicons confirmed all ten isolates as Salmonella strains. The antigenic cross-reactivity was found maximum between the HB1 (strain isolated from honeybee) antiserum and its antigen with an antibody titer of 1:128, while the HB1 antiserum showed a cross-reactive titer range of 1:8 to 1:64. On the basis of the highest geometric mean titer (GMT) shown by the antiserum of the HB1 antigen, it was selected as the best candidate for a cross-reactive live Salmonella oral antigen. Moreover, the HB1 antigen was used a live oral antigen (1 × 10¹⁰ CFU/ml) in a safety test in rabbits and proved to be avirulent. During the animal trial, three different oral doses of the HB1 live oral antigen were evaluated in four different rabbits' groups (R1, R2, R3, and R4). The dose number 2 of 0.5 ml (two drops orally and repeated after one week) gave the best GMT measured by indirect hemagglutination (IHA) as compared to the other two doses, while R4 group was kept as control. Results of the challenge protection test also validated the efficacy of the double dose of the HB1 live vaccine, which gave the highest survival percentage. Results of this study lay the foundation for a potential cross-reactive live oral Salmonella vaccine that has proved to be immunogenic in rabbits.

In this research, Salmonella species were isolated from the animal, insect and human enteric sources in Faisalabad, Punjab, Pakistan. These species were characterized by different microbiological and molecular techniques including polymerase chain reaction (PCR) by amplification of the 16S rRNA gene. Furthermore, sequencing of the amplicons confirmed all ten isolates as Salmonella strains. The antigenic cross-reactivity was found maximum between the HB1 (strain isolated from honeybee) antiserum and its antigen with an antibody titer of 1:128, while the HB1 antiserum showed a cross-reactive titer range of 1:8 to 1:64. On the basis of the highest geometric mean titer (GMT) shown by the antiserum of the HB1 antigen, it was selected as the best candidate for a cross-reactive live Salmonella oral antigen. Moreover, the HB1 antigen was used a live oral antigen (1 × 10¹⁰ CFU/ml) in a safety test in rabbits and proved to be avirulent. During the animal trial, three different oral doses of the HB1 live oral antigen were evaluated in four different rabbits’ groups (R1, R2, R3, and R4). The dose number 2 of 0.5 ml (two drops orally and repeated after one week) gave the best GMT measured by indirect hemagglutination (IHA) as compared to the other two doses, while R4 group was kept as control. Results of the challenge protection test also validated the efficacy of the double dose of the HB1 live vaccine, which gave the highest survival percentage. Results of this study lay the foundation for a potential cross-reactive live oral Salmonella vaccine that has proved to be immunogenic in rabbits.

Evaluation of a Salmonella Strain Isolated from Honeybee Gut as a Potential Live Oral Vaccine Against Lethal Infection of Salmonella Typhimurium

In this research, Salmonella species were isolated from the animal, insect and human enteric sources in Faisalabad, Punjab, Pakistan. These species were characterized by different microbiological and molecular techniques including polymerase chain reaction (PCR) by amplification of the 16S rRNA gene. Furthermore, sequencing of the amplicons confirmed all ten isolates as Salmonella strains. The antigenic cross-reactivity was found maximum between the HB1 (strain isolated from honeybee) antiserum and its antigen with an antibody titer of 1:128, while the HB1 antiserum showed a cross-reactive titer range of 1:8 to 1:64. On the basis of the highest geometric mean titer (GMT) shown by the antiserum of the HB1 antigen, it was selected as the best candidate for a cross-reactive live Salmonella oral antigen. Moreover, the HB1 antigen was used a live oral antigen (1 × 10¹⁰ CFU/ml) in a safety test in rabbits and proved to be avirulent. During the animal trial, three different oral doses of the HB1 live oral antigen were evaluated in four different rabbits’ groups (R1, R2, R3, and R4). The dose number 2 of 0.5 ml (two drops orally and repeated after one week) gave the best GMT measured by indirect hemagglutination (IHA) as compared to the other two doses, while R4 group was kept as control. Results of the challenge protection test also validated the efficacy of the double dose of the HB1 live vaccine, which gave the highest survival percentage. Results of this study lay the foundation for a potential cross-reactive live oral Salmonella vaccine that has proved to be immunogenic in rabbits.

Disseminated Salmonella infection

A 47-year-old Malay man who presented with fever, poor oral intake and loss of weight for 1 month duration. Further work-up revealed evidence of disseminated Salmonella infection that was further complicated with pericardial and pleural empyema. Cultures from pericardial and pleural fluids grew Salmonella species with negative serial blood cultures. Contrast enhanced CT thorax showed pleural effusion with large pericardial effusion. The patient was treated with antibiotics and drainage of pericardial and pleural empyema was done and he was discharged well.

Endocarditis following Consumption of Cereal Associated with Salmonella enterica Subtype Mbandaka Outbreak

A 69-year-old immunocompromised man developed mitral valve endocarditis due to Salmonella enterica serotype Mbandaka, contracted from the cereal outbreak. The patient had a history of HLA-matched related hematopoietic stem cell transplant with persistent graft-versus-host disease (GVHD). This case report discusses prior international outbreaks that occurred due to Salmonella enterica subtype Mbandaka, the risks of developing endovascular infections from salmonellosis, and persistent infections that may develop more frequently with S. enterica serotype Mbandaka. The patient received a six-week course of intravenous antibiotics and remains on oral suppressive antibiotics, with his length of therapy to be determined based on his GVHD treatment.

Correlates of non-typhoidal Salmonella bacteraemia: A case-control study

OBJECTIVE

Limited up-to-date evidence exists on host-related characteristics of non-typhoidal Salmonella (NTS) bacteraemia in high-income countries. Correlates of NTS bacteraemia in Israel were examined in this study.

METHODS

A case-control study was conducted using the medical records of patients hospitalized with NTS bacteraemia in Jerusalem during 1997-2016 (n=106; 57 children, 49 adults). Two control groups were included: (1) randomly selected controls (n=101), who were patients hospitalized due to bacteraemia with other pathogens; (2) patients with salmonellosis without bacteraemia (n=112). Age-stratified logistic regression models were constructed.

RESULTS

In children, a recent emergency room visit was associated with an increased likelihood of NTS bacteraemia. In adults, the likelihood of NTS bacteraemia versus salmonellosis increased in relation to Charlson comorbidity score (adjusted odds ratio (aOR) 1.29, 95% confidence interval (CI) 1.00-1.66, for each 1-point increase in the score), while an inverse association was found with haemoglobin level (aOR 0.72, 95% CI 0.54-0.95). Steroid therapy increased the likelihood of NTS bacteraemia compared to patients with bacteraemia due to other pathogens (aOR 5.22, 95% CI 1.01-26.93).

CONCLUSIONS

In children, NTS bacteraemia was probably present at their prior emergency room visit. A high comorbidity burden increased the likelihood of bacteraemia in adults with Salmonella infection, while haemoglobin level might be protective.

Comparative evaluation of Salmonella Typhimurium vaccines derived from UK-1 and 14028S: Importance of inherent virulence

The initial virulence and invasiveness of a bacterial strain may play an important role in leading to a maximally efficacious attenuated live vaccine. Here we show that χ9909, derived from Salmonella Typhimurium UK-1 χ3761 (the most virulent S. Typhimurium strain known to us), is effective in protecting mice against lethal UK-1 and 14028S (less virulent S. Typhimurium strain) challenge. As opposed to this, 14028S-derived vaccine χ12359 induces suboptimal levels of protection, with survival percentages that are significantly lower when challenged with lethal UK-1 challenge doses. T-cell assays have revealed that significantly greater levels of Th1 cytokines IFN-γ and TNF-α were secreted by stimulated T-lymphocytes obtained from UK-1(ΔaroA) immunized mice than those from mice immunized with 14028S(ΔaroA). In addition, UK-1(ΔaroA) showed markedly higher colonizing ability in the spleen, liver, and cecum when compared to 14028S(ΔaroA). Enumeration of bacteria in fecal pellets has also revealed that UK-1(ΔaroA) can persist in the host for over 10 days whereas 14028S(ΔaroA) titers dropped significantly by day 10. Moreover, co-infection of parent strains UK-1 and 14028S resulted in considerably greater recovery of the former in multiple mucosal and gut associated lymphatic tissues. Mice immunized with UK-1(ΔaroA) were also able to clear UK-1 infection remarkably more efficiently from the target organs than 14028S(ΔaroA). Together, these results provide ample evidence to support the hypothesis that attenuated derivatives of parent strains with higher initial virulence make better vaccines.

Salmonella enterica serovar Typhimurium isolated from the urine of a dog undergoing treatment for immune-mediated polyarthritis

INTRODUCTION

In people, Salmonella is a common agent of gastroenteritis, but it can also cause extraintestinal disease such as urinary tract infections. In addition, Salmonella is often linked to the post-infection development of reactive arthritis. In canines, cases that document extraintestinal Salmonella infections or diseases similar to reactive arthritis have not been thoroughly described.

CASE PRESENTATION

A case of a 5-year-old German shepherd dog with Salmonella bacteriuria during treatment for immune-mediated polyarthritis (IMPA) is described. The patient first suffered from a 3 month period of diarrhoea and presented for evaluation of a 2 month history of shifting-leg lameness. A diagnosis of IMPA was made based on cytological examination and negative synovial fluid culture. Treatment with immunosuppressive doses of prednisone lead to clinical resolution of lameness, but on a recheck abnormal urine was noted. Salmonella enterica serovar Typhimurium was isolated using standard culture methods. The patient was treated with enrofloxacin to control the bacteriuria.

CONCLUSION

This case report is, to the best of our knowledge, the first to describe Salmonella bacteriuria in a dog and suggests that Salmonella infection may be a potential inciting factor for IMPA.

Purulent constrictive pericarditis caused by Salmonella enteritidis in a patient with adult-onset Still's disease: A case report

RATIONALE

Purulent pericarditis is a rare and usually fatal disease. Immunodeficiency state and preexisting pericardial effusion can predispose patients to infections. However, we are not aware of similar cases in patients with adult-onset Still's disease (AOSD). In addition, it is seldom caused by Salmonella bacteria.

PATIENT CONCERNS

We report a 30-year-old woman with dyspnea on exertion and epigastric fullness. She was newly diagnosed with AOSD 4 months previously and medicated with prednisolone.

DIAGNOSES

Transthoracic echocardiography (TTE) and computed tomography revealed a thickened pericardium with loculations in the pericardial space, consistent with purulent constrictive pericarditis. Subsequent cultures of blood and pericardial fluid yielded S enteritidis.

INTERVENTIONS

She underwent subtotal pericardiectomy through a limited median sternotomy, and antibiotic therapy (ceftriaxone) for 1 month.

OUTCOMES

The New York Heart Association functional classification downgraded from class III to class I. There was no recurrence during the 1-year follow-up.

LESSONS

This case presents an opportunity to highlight the importance of considering purulent pericarditis in patients previously diagnosed with AOSD. High clinical suspicion, early diagnosis, and prompt management can result in a better outcome in purulent pericarditis.

Purulent Pericarditis with Salmonella enterica Subspecies arizona in a Patient with Type 2 Diabetes Mellitus

Purulent pericarditis is a life-threatening disorder, even in the modern antibiotic era. Although diabetes mellitus is known to be associated with an increased risk of multiple types of infections, purulent pericarditis is extremely rare. We herein report an unusual case of pericarditis caused by Salmonella enterica subspecies arizona that was not associated with any evident underlying immunosuppressive disorder apart from uncontrolled type 2 diabetes mellitus. Because a pet snake was suspected as being the source of infection in the present case, patient education and a detailed review of exposure history could play an important role in treating patients with diabetes mellitus.

Salmonella enteritidis primary bacteremia in previously healthy patient from Taiwan: case report

BACKGROUND

Diseases caused by invasive nontyphoidal Salmonella strains present with various extraintestinal manifestations, including bacteremia. Factors affecting the incidence include Salmonella serotype, geographic location, and host factors.

CASE

We present an unusual case of Salmonella enteritidis primary bacteremia in a patient without any risk factors and originating from a region with the lowest burden of invasive nontyphoidal Salmonella infections. We observed an incomplete clinical response to the treatment with a third-generation cephalosporin, despite the in vitro susceptibility of the strain.

DISCUSSION

The diagnosis of Salmonella bacteremia was far from expected in our previously healthy patient from Taiwan, without any preceding diarrhea and the lack of marked response to therapy with ceftriaxone. Making the diagnosis was a challenge, requiring wide range of laboratory, imaging, and consultative work to rule out alternative diagnoses and complications.

CONCLUSION

Invasive Salmonella infections are uncommon in our clinical practice at the present. Air transportation, intensive migration processes, and changes in climate are able to change the burden of infectious diseases dramatically in the near future. That fact along with the raising antibacterial resistance among invasive nontyphoidal Salmonella strains make imperative the profound understanding of the epidemiology and pathophysiology of those infections.

Pleural empyema due to Salmonella enterica serovar Enteritidis in an immunocompetent elderly patient: a case report

INTRODUCTION

Pleural empyema as a focal infection due to Salmonella enterica serovar Enteritidis is rare and most commonly described among immunosuppressed patients or patients who suffer from sickle cell anaemia and lung malignancies.

CASE PRESENTATION

Here, we present an 81-year-old immunocompetent Greek woman with bacteraemia and pleural empyema due to Salmonella Enteritidis without any gastrointestinal symptoms.

CONCLUSION

In our case, we suggest that patient's pleural effusion secondary to heart failure was complicated by empyema and that focal intravascular infection was the cause of bacteraemia.

First Case of Lung Abscess due to Salmonella enterica Serovar Abony in an Immunocompetent Adult Patient

In healthy individuals, nontyphoidal Salmonella species predominantly cause a self-limited form of gastroenteritis, while they infrequently invade or cause fatal disease. Extraintestinal manifestations of nontyphoidal Salmonella infections are not common and mainly occur among individuals with specific risk factors; among them, focal lung infection is a rare complication caused by nontyphoidal Salmonella strains typically occurring in immunocompromised patients with prior lung disease. We describe the first case of a localized lung abscess formation in an immunocompetent healthy female adult due to Salmonella enterica serovar Abony. The patient underwent lobectomy and was discharged after full clinical recovery. This case report highlights nontyphoidal Salmonellae infections as a potential causative agent of pleuropulmonary infections even in immunocompetent healthy adults.

Pericardial salmonella with cardiac tamponade and ventricular wall rupture: A case report

Introduction

Non-typhoidal Salmonella (NTS) is mostly restricted to gastroenteritis; however, we report a case of Salmonella pericarditis complicated by tamponade and spontaneous ventricular wall rupture.

Case presentation

A 67-year-old male presents to the Emergency Department with complaints of fevers, chills and body aches. A chest radiograph displayed an infiltrate and an electrocardiogram suggested acute pericarditis. An echocardiogram revealed a small pericardial effusion without tamponade. Broad-spectrum antibiotics were initiated until Salmonella was discovered in blood cultures. The hospital course was complicated by sudden decompensation, and a repeat echocardiogram displayed a large effusion with constrictive physiology. During a pericardial window, the tissue was noted to have a thickened appearance with a complex effusion. The following day, the patient developed increased chest tube drainage, hypotension and acidosis, requiring an emergent sternotomy. The right ventricle was friable and had spontaneously ruptured. After ventricular repair and pericardiectomy, the tissue was sent for cultures and pathology. The specimen revealed Salmonella enteriditis. Treatment with ceftriaxone and ciprofloxacin was initiated. On postoperative day four, the patient was successfully extubated. Repeat blood cultures were negative.

Discussion

In our review of literature, only 19 cases of NTS pericarditis have been reported. Prior to our case, salmonellosis resulting in ventricular rupture has been reported once. Early diagnosis and treatment is crucial in minimizing morbidity and mortality. Clinical suspicion based on electrocardiogram and hemodynamic assessment is critical in suspecting pericardial effusion in a patient with nonspecific symptoms and Salmonella bacteremia. The key to recovery involves aggressive treatment, including pericardiectomy and antibiotic treatment.

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Patient with Salmonella pericarditis complicated by tamponade and ventricle rupture.

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Salmonella enteriditis bacteremia secondary to a cardiac source.

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Promptly diagnose and treat patients with hemodynamic compromise from tamponade.

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Consider a cardiac etiology when faced with Salmonella bacteremia.

Immunogenicity and Cross-Protective Efficacy Induced by Outer Membrane Proteins from Salmonella Typhimurium Mutants with Truncated LPS in Mice

Lipopolysaccharide (LPS) is a major virulence factor present in the outer membrane of Salmonella enterica serovar Typhimurium (S. Typhimurium). Outer membrane proteins (OMPs) from Salmonella show high immunogenicity and provide protection against Salmonella infection, and truncated LPS alters the outer membrane composition of the cell wall. In our previous study, we demonstrated that Salmonella mutants carrying truncated LPS failed to induce strong immune responses and cross-reaction to other enteric bacteria, due to their high attenuation and low colonization in the host. Therefore, we plan to investigate whether outer membrane proteins from Salmonella mutants with truncated LPS resulting from a series of nonpolar mutations, including ∆waaC12, ∆waaF15, ∆waaG42, ∆rfaH49, ∆waaI43, ∆waaJ44, ∆waaL46, ∆wbaP45 and ∆wzy-48, affect immunogenicity and provide protection against diverse Salmonella challenge. In this study, the immunogenicity and cross-protection efficiency of purified OMPs from all mutants were investigated to explore a potential OMP vaccine to protect against homologous or heterologous serotype Salmonella challenge. The results demonstrated that OMPs from three Salmonella mutants (∆waaC12, ∆waaJ44 and ∆waaL46) induced higher immune responses and provided good protection against homologous S. Typhimurium. The OMPs from these three mutants were also selected to determine the cross-protective efficacy against homologous and heterologous serotype Salmonella. Our results indicated that the mutant ∆waaC12 can elicit higher cross-reactivity and can provide good protection against S. Choleraesuis and S. Enteritidis infection and that the cross-reactivity may be ascribed to an antigen of approximately 18.4–30 kDa.