Bratisl Lek Listy 2010; 111 (4) '" ` '' Indexed and abstracted in Science Citation Index Expanded and in Journal Citation Reports/Science Edition EXPERIMENTAL STUDY Bacterial translocation in experimental stroke: what happens to the gut barrier? Nida Tascilar 1 , Oktay Irkorucu 2 , Oge Tascilar 2 , Fusun Comert 3 , Ozlem Eroglu 3 , Burak Bahadir 4 , Guldeniz Karadeniz Cakmak 2 , Handan Ankarali 5 , Hale Sayan 6 1 Department of Neurology, Zonguldak Karaelmas University Medical Faculty, Zonguldak, Turkey, 2 Department of General Surgery, Zonguldak Karaelmas University Medical Faculty, Zonguldak, Turkey, 3 Department of Microbiology, Zonguldak Karaelmas University Medical Faculty, Zonguldak, Turkey, 4 Department of Pathology, Zonguldak Karaelmas University Medical Faculty, Zonguldak, Turkey, 5 Department of Biosta- tistics, Zonguldak Karaelmas University Medical Faculty, Zonguldak, Turkey, and 6 Department of Physiology, Zonguldak Karaelmas Univer- sity Medical Faculty, Zonguldak, Turkey Address for correspondence: Oktay Irkorucu, MD, Dept of General Surgery, Zonguldak Karaelmas University Medical Faculty, 67600, Zonguldak, Turkey Phone: +903.722667375, Fax: +903.722610155 Stroke is one of the most frequently encountered problems in neurology clinics. Infections and sepsis are the major compli- cations that determine the morbidity and mortality in these pa- tients (15) The incidence of infections, which are a leading cause of death in patients with stroke varies from 21 % to 65 % in the literature (1, 2). Although old age, diabetes mellitus, severe neu- rologic impairment, immunity disorders, malnutrition, unsafe swallowing with dysphagia, subsequent aspiration, and presence of oral pathogens are considered to be major contributors to the high incidence of infections and sepsis after stroke (3, 4), the reasons for the high incidence of infections and sepsis in pa- tients sustaining a stroke are still incompletely understood and the mechanisms of infections complicating the clinical course of acute stroke have received limited investigation (58). Damage to intestinal mucosa in inflammatory and metabolic responses to critical illnesses has been increasingly recognized Department of General Surgery, Zonguldak Karaelmas University Medical Faculty, Zonguldak, Turkey. oktaytip@yahoo.com Abstract: The reasons of post-stroke infections are still incompletely understood. Bacterial translocation (BT), the passage of viable microbes across an even anatomically intact intestinal barrier, has been described in many critical illnesses. To date, it has not been studied as a source of infection in an animal stroke model. To address this, a permanent left middle cerebral artery occlusion (MCAO) model in rats was used. After 24, 48, and 72 hours (h), sham and experimental groups were sacrificed and samples were taken for BT. Similarity between bacteria detected in tissues (blood, mesenteric lymph node, liver, spleen, and lung) and intestinal microflora was shown with phenotypic methods and antibiotyping. Possible ileum tissue injuries were shown by histopathologic examination (including morphometric analysis). Although there was no bacterial proliferation in the sham groups, 55.5 %, 45.4 %, and 30 % bacterial proliferation was detected in MCAO groups at post- operative hour 24, 48, and 72, respectively. In MCAO groups the bacterial proliferation in tissues and ileum tissue injury scores were higher over time compared to sham groups (p<0.05). Our findings support the view that stroke, itself leads to mucosal damage and bacterial translocation (Tab. 5, Fig. 2, Ref. 27). Full Text (Free, PDF) www.bmj.sk. Key words: stroke, bacterial translocation, ICAM-1, infection, inflammation, gut barrier. (69). Bacterial translocation (BT) was defined as the invasion of indigenous intestinal bacteria through the gut mucosa into normal sterile tissue, causing disease (911). To date, it has not been studied as a source of infection in an animal stroke model. However, despite decades of research and clinical trials, there is inadequate information about the effects of stroke on gut barrier function and bacterial translocation (519). To the best of our knowledge, the role of stroke, leading to bacterial translocation in an animal model, has not been investi- gated before. Therefore, in the study reported here, we investi- gated the effects of stroke on gut barrier and bacterial transloca- tion in rats. Materials and methods Experimental design and Focal Brain Ischemia Fiftyseven male Wistar rats weighing 220 to 250 g were anes- thetized with ketamine hydrochloride (50 mg/kg intramuscularly). The animals were randomly assigned to either the left middle cerebral artery occlusion (MCAO) or sham group. The surgical procedure of permanent MCAO was performed as described else- where (14). Briefly, a 4-0 polypropylene (Ethicon, USA) mono- filament suture was introduced into the common carotid artery under ketamine hydrochloride anesthesia, while body tempera- ture was kept constant (37 °C) with heating pad. The filament was prepared by blunting the tip near a flame under 10x magni- fication. MCAO was accomplished by further advancing the fila- ment in the internal carotid artery until a faint resistance was