Small bowel perforation secondary to enteric Salmonella paratyphi A infection

Salmonella enterica serovar Paratyphi A-induced immune response in Caenorhabditis elegans depends on MAPK pathways and DAF-16

Salmonella enterica serovar Paratyphi A (S. Paratyphi A) is a pathogen that can cause enteric fever. According to the recent epidemic trends of typhoid fever, S. Paratyphi A has been the major important causative factor in paratyphoid fever. An effective vaccine for S. Paratyphi A has not been developed, which made it a tricky public health concern. Until now, how S. Paratyphi A interacts with organisms remain unknown. Here using lifespan assay, we found that S. Paratyphi A could infect Caenorhabditis elegans (C. elegans) at 25°C, and attenuate thermotolerance. The immune response of C. elegans was mediated by tir-1, nsy-1, sek-1, pmk-1, mpk-1, skn-1, daf-2 and daf-16, suggesting that S. Paratyphi A could regulate the MAPK and insulin pathways. Furthermore, we observed several phenotypical changes when C. elegans were fed S. Paratyphi A, including an accelerated decline in body movement, reduced the reproductive capacity, shortened spawning cycle, strong preference for OP50, arrested pharyngeal pumping and colonization of the intestinal lumen. The virulence of S. Paratyphi A requires living bacteria and is not mediated by secreting toxin. Using hydrogen peroxide analysis and quantitative RT-PCR, we discovered that S. Paratyphi A could increase oxidative stress and regulate the immune response in C. elegans. Our results sheds light on the infection mechanisms of S. Paratyphi A and lays a foundation for drugs and vaccine development.

A rare presentation of an acute abdomen: an ileal diverticular perforation

Background

This case report highlights the value of prompt intervention of diagnostic laparoscopy in a patient suspects of having an acute abdomen due to an intestinal perforation, where there is a limitation of performing Contrast Enhanced Computed Tomography of abdomen. A previously healthy young adult presenting with an acute abdomen due to a spontaneous ileal perforation, without any associated risk factors is a rare clinical entity in a developing country. Therefore, entertaining an early diagnosis will possibly prevent a fatal consequence.

Case presentation

A male patient, 29 years old, recently diagnosed as a young hypertensive without any associated factors, currently on antihypertensive treatment, was admitted to our hospital presenting with an acute severe abdominal pain. During initial assessment, the patient was febrile (101 °F), ill looking, tachycardic (pulse rate 121 bpm) with rapid shallow breathing. Abdominal examination reviled diffuse guarding and rigidity, more severe on right iliac fossa. Following history and clinical examination probable clinical diagnosis was made as an acute appendicitis with perforation. However, ultrasonography was found to have normal appendix. Contrast Enhanced Computed Tomography was not performed as a subsequent investigation because of the impairment of renal functions of this patient. Though, non-contrast CT would have been ascertained more diagnostic yield, given the critically ill status of this patient we decided to perform urgent diagnostic laparoscopy. It reviled pus in several abdominal cavities and dense adhesions. Therefore, the procedure was converted to a laparotomy and found to have an ileal perforation with diffuse peritoneal contamination. Diseased ileal segment was resected and anastomosed. Followed by peritoneal lavage.

Conclusion

Ileal perforation due to diverticular disease in a healthy young adult is rare. This case report highlights the importance of considering this clinical entity as a differential diagnosis, the value of early diagnostic laparoscopy, especially in clinical settings with limitations to CT scan, since late diagnosis can give rise to fatal outcome.

Spontaneous free perforation of the small intestine in adults

Spontaneous free perforation of the small intestine is uncommon, especially if there is no prior history of visceral trauma. However, free, even recurrent, perforation may complicate a defined and established clinical disorder, such as Crohn’s disease. In addition, free perforation may be the initial clinical presentation of an occult intestinal disorder, such as a lymphoma complicating celiac disease, causing diffuse peritonitis and an acute abdomen. Initial diagnosis of the precise cause may be difficult, but now has been aided by computerized tomographic imaging. The site of perforation may be helpful in defining a cause (e.g., ileal perforation in Crohn’s disease, jejunal perforation in celiac disease, complicated by lymphoma or collagenous sprue). Urgent surgical intervention, however, is usually required for precise diagnosis and treatment. During evaluation, an expanding list of other possible causes should be considered, even after surgery, as subsequent management may be affected. Free perforation may not only complicate an established intestinal disorder, but also a new acute process (e.g., caused by different infectious agents) or a longstanding and unrecognized disorder (e.g., congenital, metabolic and vascular causes). Moreover, new endoscopic therapeutic and medical therapies, including use of emerging novel biological agents, have been complicated by intestinal perforation. Recent studies also support the hypothesis that perforation of the small intestine may be genetically-based with different mutations causing altered connective tissue structure, synthesis and repair.