Bacterial translocation and mortality on rat model of intestinal ischemia and obstruction

Abstract Purpose: To develop an experimental model of intestinal ischemia and obstruction followed by surgical resection of the damaged segment and reestablishment of intestinal transit, looking at bacterial translocation and survival. Methods: After anesthesia, Wistar rats was subject to laparotomy, intestinal ischemia and obstruction through an ileal ligature 1.5cm of ileum cecal valve; and the mesenteric vessels that irrigate upstream of the obstruction site to approximately 7 to 10 cm were ligated. Abdominal wall was closed. Three, six or twenty-four hours after, rats were subject to enterectomy followed by an end to end anastomosis. After 24h, mesenteric lymph nodes, liver, spleen and lung tissues were surgically removed. It was studied survival rate and bacterial translocation. GraphPadPrism statistical program was used. Results: Animals with intestinal ischemia and obstruction for 3 hours survived 24 hours after enterectomy; 6hx24h: survival was 70% at 24 hours; 24hx24h: survival was 70% and 40%, before and after enterectomy, respectively. Culture of tissues showed positivity on the 6hx24h and negativity on the 3hx24h. Conclusion: The model that best approached the clinic was the one of 6x24h of ischemia and intestinal obstruction, in which it was observed bacterial translocation and low mortality rate.

Bacterial translocation in an experimental intestinal obstruction model: C-reactive protein reliability? / Translocação bacteriana no modelo experimental de obstrução intestinal: A proteína C-reativa é confiável?

BACKGROUND: Bacterial translocation occurs in preseptic conditions such as intestinal obstruction through unclear mechanism. The C-reactive protein is an acute phase reactant and a marker of ischemia. METHODS: 45 albino male rats were divided into 3 groups each 15 rats. GI control, GII simple intestinal-obstruction and GIII strangulated obstruction. Outcome measures were: (1) Bacteriologic count and typing for intestinal contents, intestinal wall, liver, mesenteric lymph nodes and blood (cardiac and portal) (2) Histopathologic: mucosal injury score, inflammatory cell infiltrate in the wall, MLN, liver, (3) Biochemical: serum CRP, IL-10, mucosal stress pattern (glutathione peroxidase-malonyldialdhyde tissue levels). RESULTS: (1) Intestinal obstruction associates with BT precursors (Bact-overgrowth, mucosal-acidosis, immuno-incomptence), (2) Bacterial translocation (frequency and density) was found higher in strangulated I.O, that was mainly enteric (aerobic and anaerobic) and mostly E.coli, (3) The pathogen commonality supports the gut origin hypothesis but the systemic inflammatory response goes with the cytokine generating one. (4) The CRP median values for GI, II, III were 0.5, 6.9, 8.5 mg/L, for BT +ve 8 mg/L and 0.75 mg/L for BT -ve rats. CONCLUSION: Bacterial translocation occurs bi-directional (systemic-portal) in intestinal obstruction and the resultant inflammatory response pathogenesis is mostly 3 hit model. The CRP is a non selective marker of suspected I.O cases. However, it is a reliable marker of BT, BT density and vascular compromise during I.O.

OBJETIVO: Translocação bacteriana ocorre em condições pré-sépticas como na obstrução intestinal por mecanismo não esclarecido. A proteína C-reativa é um marcador de ischemia em fase aguda. A proposição é investigar os possíveis efeitos da obstrução intestinal no equilíbrio ecológico microbiano. MÉTODOS: 45 ratos machos albinos foram distribuídos em três grupos de 15 ratos. GI controle, GII obstrução intestinal simples e GIII obstrução estrangulada. As medidas adotadas foram: (1) Contagem bacteriológica do conteúdo intestinal, parede intestinal, fígado, linfonodos mesentéricos e sangue (coração e portal) (2) Avaliação histopatológica da lesão da mucosa, infiltrado celular inflamatório da parede, linfonodos mesentéricos, fígado, (3) Avaliação bioquímica. RESULTADOS: (1) Obstrução intestinal está associada a precursora translocação bacteriana (crescimento bacteriano, acidose da mucosa, imuno-incompetência), (2) Translocação bacteriana (freqüência e densidade) foi maior na obstrução intestinal estrangulada, principalmente entérica (aeróbios e anaeróbios), sobretudo E.coli, (3) A ocorrência comum é de origem intestinal. CONCLUSÃO: A translocação bacteriana na obstrução intestinal é bi-direcional (sistêmica e portal) A proteina C-reativa não é um marcador seletivo na suspeita de obstrução intestinal. Contudo é marcador confiável da translocação bacteriana, na densidade e comprometimento durante a obstrução intestinal.

Mesenteric microcirculatory dysfunctions and translocation of indigenous bacteria in a rat model of strangulated small bowel obstruction

PRUPOSE: Bacterial translocation has been shown to occur in critically ill patients after extensive trauma, shock, sepsis, or thermal injury. The present study investigates mesenteric microcirculatory dysfunctions, the bacterial translocation phenomenon, and hemodynamic/metabolic disturbances in a rat model of intestinal obstruction and ischemia. METHODS: Anesthetized (pentobarbital 50 mg/kg, i.p.) male Wistar rats (250-350 g) were submitted to intestinal obstruction or laparotomy without intestinal obstruction (Sham) and were evaluated 24 hours later. Bacterial translocation was assessed by bacterial culture of the mesenteric lymph nodes (MLN), liver, spleen, and blood. Leukocyte-endothelial interactions in the mesenteric microcirculation were assessed by intravital microscopy, and P-selectin and intercellular adhesion molecule (ICAM)-1 expressions were quantified by immunohistochemistry. Hematocrit, blood gases, lactate, glucose, white blood cells, serum urea, creatinine, bilirubin, and hepatic enzymes were measured. RESULTS: About 86 percent of intestinal obstruction rats presented positive cultures for E. coli in samples of the mesenteric lymph nodes, liver, and spleen, and 57 percent had positive hemocultures. In comparison to the Sham rats, intestinal obstruction induced neutrophilia and increased the number of rolling (~2-fold), adherent (~5-fold), and migrated leukocytes (~11-fold); this increase was accompanied by an increased expression of P-selectin (~2-fold) and intercellular adhesion molecule-1 (~2-fold) in the mesenteric microcirculation. Intestinal obstruction rats exhibited decreased PaCO2, alkalosis, hyperlactatemia, and hyperglycemia, and increased blood potassium, hepatic enzyme activity, serum urea, creatinine, and bilirubin. A high mortality rate was observed after intestinal obstruction (83 percent at 72 h vs. 0 percent in Sham rats). CONCLUSION: Intestinal obstruction and ischemia in rats is a relevant model for ...

Frequency of intestinal tuberculosis in operated cases intestinal obstruction

To review the cases of intestinal tuberculosis in operated cases of intestinal obstruction. Prospective/retrospective descriptive study. Surgical ward-2, Jinnah Postgraduate Medical Centre, Karachi from 1st March, 2000 to 28th February, 2002. Total 246 patients of intestinal obstruction were operated in this period, amongst them 62 patients were found to be intestinal tuberculosis. All these patients were admitted through Accident and Emergency Department. Intestinal tuberculosis as a cause of intestinal obstruction was found in 62 [25.2%]patients. Mean age was 27.36 years. There were 32 [51%] male and30 [49%] female. Symptoms and signs of intestinal obstruction were found in all patients while peritonitis secondary to intestinal obstruction was found in 18 [29.03%] patients. Other symptoms of tuberculosis such fever, night sweats, weight loss was also present in significant number of these patients. After relevant investigations exploratory laparotomy was performed. Small intestinal stricture was commonest cause of intestinal obstruction found in 38 [61.29%] patients Mass in right iliac fossa found in 18 [29.03%] patients Six [9.67%] pa- tients had adhesions as a cause of intestinal obstruction with strictures as an incidental finding. Perforation of the small bowel secondary to intestinal obstruction was found in 18 [29,03%] patients. Stricturoplasty was the commonest procedure performed in 20 [32.25%] patients. Right hemicolectomy was second commonest procedure after stricture-plasty performed in 16 [25.80%n] patients. Other procedures performed include resection of the strictured or perforated segment followed either by end to end anastomosis or by end ileostomy. Me- senteric lymph nodes found enlarged in all patients and taken for biopsy. Antituberculous therapy was given to all patients. Frequency of intestinal tuberculosis is significantly high in our population and it is increasing at alarming rate

Translocaçäo bacteriana na obstruçäo aguda do cólon esquerdo / Bacterial translocation in the acute obstruction of left colon

O cólon esquerdo é sede freqüente de obstruçäo intestinal e os resultados do tratamento cirúrgico nessa situaçäo estäo associados a maior morbi-mortalidade pós-operatória. O objetivo deste trabalho foi o de investigar experimentalmente a ocorrência de translocaçäo bacteriana na obstruçäo aguda do cólon esquerdo. 26 ratos Wistar foram submetidos a laparotomia mediana sendo obstruídos no cólon esquerdo com um nó de linho a 2,5 cm acima da reflexäo peritoneal (grupo obstruçäo; n=13) ou näo (grupo controle; n=13). 24h após, foram novamente reoperados para coleta dos linfonodos mesentéricos, fígado, baço e de uma amostra de sangue caval. As peças foram homogeneizadas e enviadas para cultura. Observou-se uma maior incidência de culturas positivas nos animais do grupo obstruçäo tanto nos linfonodos (8/10 vs. 3/13; p<0.01) quanto no fígado (7/10 vs. 1/13; p<0.01) e no baço (8/10 vs. 4/13; p<0.05). No sangue, 6 dos 10 ratos obstruídos apresentaram cultura positiva enquanto que isso näo ocorreu em nenhum rato do grupo controle (p<0.01). As bactérias mais freqüentes nas culturas foram a Escherichia coli, Proteus vulgaris e Klebsiella pneumoniae. A obstruçäo aguda do cólon esquerdo neste modelo animal determina a ocorrência de translocaçäo bacteriana

Intestinal bleeding and occlusion associated with shiga toxin-producing Escherichia coli 0127: H21

We report a case of a nine-year old boy with vomiting, abdominal pain and fever, who underwent surgery with a diagnosis of appendicitis in Mendonza and from whom a Shiga toxin-producing Escherichia coli (STEC) 0127:H21 strain was recovered. Forty-eight hours after surgery he presented bilious vomiting and two episodes of intestinal bleeding. Loboratory findings included: hematocrit, 35 per cent; blood urea nitrogen, 0.22 g/L. The urinary output was normal. The following day physical examination showed an alert mildy hydrated child, without fever but with distended and painful abdomen. The patient was again submitted to surgery with a diagnosis of intestinal occlusion. Bleeding and multiple adhesions in jejunum and ileum were found. The patient still had tense and painful abdomen and presented two bowel movements with blood; hematocrit fell to 29 per cent and blood urea nitrogen rose to 0.32 g/L. STEC 0127:H21 eae(-)/Stx2/Stx2vh-b(+)/E-Hly(+) was isolated from a stool sample. He was discharged after 10 days of hospitalization and no long-term complications such as HUS or TTP were observed. This is the first report, to our knoweledge, on the isolation of E.coli 0127:H21, carrying the virulence factors that characterize STEC strains, associated to an enterohemorrhagic colitis case. This serotype was previously characterized as a non-classic enteropathogenic E. coli (EPEC). STEC infections can mimic infectious or noninfectious pathologies. Therefore an important aspect of clinical managements is making the diagnosis using different criteria thereby avoiding misdiagnoses which have occasionally led to invasive diagnostic and therapeutic procedures or the inappropriate use of antibiotics.

Factores involucrados en la translocación bacteriana en un modelo experimental de obstrucción intestinal / Involucrate factors in bacterial translocation in a experimental model of intestinal obstruction

Se deseño un modelo experimental de obstrucción intestinal (OI) a fin de estudiar las alteraciones histológicas a nivel de la pared intestinal y nódulos linfáticos mesntéricos (NLM). Para tal efecto se utilizaron 32 ratas Sprague-Darley las cuales bajo anestesia con tiopental sódico les fue practicada una laparotomía + ligadura del íleon con seda 3-0 causando oclusión completa de su luz. A diferentes intervalos de producirse la OI (24, 48, 72 y 96 horas), posterior a su sacrificio mediante dislocación cervical se analizaron histológicamete los diferentes grupos. A las 24 horas post OI se apreció congestión y edema de la pared intestinal, presencia de infiltrado celular inflamatorio a nivel de la lámina propia y reactividad de los NLM. A las 48 horas se incrementó el edema y la congestión, se evidenció fragmentación de la mucosa y translocación fragmentación de la mucosa y translocacióy translocación de bacterias a través de ella, las cuales alcanzaron los nódulos linfáticos de la pared. A nivel de los NLM la histiocitosis era mayor. La constatación de TB en la OI amplía aún más el conjunto de alteraciones observadas en esta patología donde no sólo se produce la absorción de productos tóxicos y endotoxinas a nivel del segmento comprometimento y que pudiesen explicar la bacteriemia y la sepsis en este tipo de pacientes

Obstrucción intestinal por ascaris en el niño / Intestinal obstruction by ascaris in the child

La obstrucción intestinal por el Ascaris en el niño, además de su frecuencia, plantea algunas consideraciones especiales muy peculiares, por cuya razón hemos realizado este trabajo de investigación. Se encasillaron todas las historias clínicas con el diagnóstico de obstrucción intestinal por Ascaris en un período de 10 años (1975-1984), siendo el total de los casos en un número de 18, se tuvieron en cuenta parámetros clínicos y/o radiológicos. De la totalidad de niños ingresados en la Cátedra de Pediatría en el lapso de 10 años (1975-1984), que suman 19.583, hubo 63 casos de obstrucciones intestinales por diversas causas, constituyendo un 0,31% del total de ingresados. Pero del total de 63 casos 18 correspondieron a una obstrucción por el ascaris, representando un 28,5% del total de las obstrucciones, cifra considerada muy elevada, ya que la bibliografía internacional apenas menciona 1 - 2 casos en el período que abarcó nuestra investigación. La mortalidad fue de 2 casos (11%), teniendo como causa principal a la peritonitis por perforación intestinal debida al ascaris