• Korean Journal of Veterinary Research
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• v.47 no.1
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• pp.77-84
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• 2007

Helicobacter pylori (H. pylori) is an important bacterial pathogen that causes chronic gastritisand is associated with gastroduodenal ulcer disease, adenocarcinoma of the distal stomach, and gastricH. pylori infection associated with host agehave not been well-defined in human. To evaluate the difference in host susceptibility to infection in relationto age of acquisition of H. pylori infection, we designed an experiment involving inoculation of H. pyloriATC 43504 at different ages of Mongolian gerbils. H. pylori was inoculated at 5 weeks and 18 monthsof age, as representatives of early and late infection, respectively. Animals were sacrificed 1 week and 4weeks after challenge, and the stomach was removed from each animal for bacterial culture, histologicalexamination, and polymerase chain reaction test. 5 week-old gerbils revealed infection andmaintained continuously its infection until 4 weeks. However, old gerbils did not maintained H. pyloriinfection. These data suggest the insusceptibility of H. pylori in old Mongolian gerbils and the importanceof animal ages for successful animal experimental infection. Also, the results demonstrated that earlyinfection of H. pylori increases its host susceptibility, as compared to the case with later infection, possiblybecause of differences in host gastric mucosal factors and imunologic responses.

• Tuberculosis and Respiratory Diseases
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• v.68 no.4
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• pp.205-211
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• 2010

Background: Procalcitonin is a well known marker in infection that plays a role in distinguishing between bacterial and viral infections in screening. The aim of the present study was to evaluate the role of procalcitonin in differentiating between 2009 H1N1 influenza pneumonia and community acquired pneumonia of bacterial origin, or mixed bacterial origin and 2009 H1N1 influenza infection. Methods: A retrospective observational study was performed over the 6-month winter period during the 2009 H1N1 influenza pandemic. Ninety-six patient-subjects were enrolled, all of whom had been diagnosed with community acquired pneumonia in emergency department during the study period. On admission, laboratory studies were performed, which included 2009 H1N1 influenza real-time polymerase chain reaction of nasal secretions and procalcitonin on serum; the laboratory values were compared between the study groups. Receiver operating characteristic curve analyses were performed on the resulting data. Results: Compared to those with bacterial or mixed infections (n=62) and bacterial pneumonia with confirmed organisms (n=30), patients with 2009 H1N1 pneumonia (n=34) were significantly more likely to have low procalcitonin levels (p=0.008, 0.001). Using cutoff of value >0.3 ng/mL, the sensitivity and specificity of procalcitonin for detection of patients with confirmed bacterial pneumonia were 76.2% and 60.6%, respectively. A significant difference in procalcitonin was found between 2009 H1N1 pneumonia and pneumonia caused by mixed influenza viral and bacterial infections (0.15 [0.05~0.84] vs. 10.3 [0.05~22.87] ng/mL, p=0.045). Conclusion: Serum procalcitonin measurement may assist in the discrimination between pneumonia of bacterial and of 2009 H1N1 influenza origin. High values of procalcitonin suggest that bacterial infection or mixed infection of bacteria and 2009 H1N1 influenza is more likely.

• Journal of Veterinary Clinics
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• v.37 no.6
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• pp.342-344
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• 2020

Bacterial osteomyelitis-or bacterial infection of the bone-is common in reptiles. Unfortunately, its treatment is challenging despite advances in diagnostic and medical technologies. Herein, we present the case of a sexually mature female bearded dragon (Pogona vitticeps) with left forelimb elbow joint stiffness. We diagnosed the reptile with a eft elbow joint traumatic structural abnormality based on gross examination and evaluation of radiographs. Treatment with clindamycin and cephalexin for bacterial infection failed and the reptile died. Necropsy revealed the causative bacteria as Morganella morganii. Treatment of osteomyelitis is typically focused against Staphylococcus aureus as it the most common cause of traumatic bone infection. However, M. morganii, the causative bacterium in this case, has a natural resistance to clindamycin and cephalexin. Recently, these bacteria have begun to appear in clinical reports, more commonly as the causative organisms of bone infections. M. morganii should be considered as a potential cause of infection. Furthermore, antibiotic treatment in such cases should be based on bacterial culture and susceptibility tests.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.1
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• pp.41-51
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• 2022

Purpose: Community-acquired bacterial enteritis (CABE) is a common problem in developed countries. It is important to understand the epidemiologic changes in bacterial pathogens for prevention and treatment. Therefore, we studied the epidemiologic changes in CABE in Korean children. Methods: A total of 197 hospitalized pediatric patients aged <19 years that presented with dysentery symptoms and showed positive polymerase chain reaction results for bacterial species in stool samples, were enrolled in this study for 10 years (June 2010 to June 2020). We classified patients in phase I (06, 2010-06, 2015) and phase II (07, 2015-06, 2020) and analyzed their epidemiologic and clinical characteristics. Results: The most common pathogens were Campylobacter species (42.6%) and Salmonella species were the second most common pathogens (23.9%). The abundance of pathogens decreased in the following order: Clostridium difficile (9.6%), Shigella (5.6%), and Clostridium perfringens (5.6%). Escherichia coli O157:H7 was found to be the rarest pathogen (2.0%). Campylobacter species showed an increase in the infection rate from 32.1% in phase I to 49.6% in phase II (p=0.0011). Shigella species showed a decline in the infection rate in phase I from 14.1% to 0.0% in phase II (p<0.001). C. difficile and C. perfringens showed an increase in infection rate in phase II compared to phase I, but the difference was not statistically significant. Conclusion: The infection rate of Campylobacter species in CABE has been rising more recently, reaching almost 50%. This study may help establish policies for prevention and treatment of CABE in Korean children.

• Research in Plant Disease
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• v.22 no.3
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• pp.168-177
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• 2016

A forecast model for estimating the infection risk of bacterial canker caused by Pseudomonas syringae pv. actinidiae on kiwifruit leaves in Korea was developed using the generic infection model of Magarey et al. (2005). Two-way contingency table analysis was carried out to evaluate accuracy of forecast models including the model developed in this study for estimating the infection of bacterial canker on kiwifruit using the weather and disease data collected from three kiwifruit orchards at Seogwipo in 2015. All the tested models had more than 80% of probability of detection indicating that all the tested models could be effective to manage the disease. The model developed in this study showed the highest values in proportion of correct (51.1%), probability of detection (90.9%), and critical success index (47.6%). It indicated that the model developed in this study would be the best model for estimating the infection of bacterial wilt on kiwifruit leaves in Korea. The model developed in this study could be used for a part of decision support system for managing bacterial wilt on kiwifruit leaves and help growers to reduce the loss caused by the disease in Korea.

• IMMUNE NETWORK
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• v.22 no.4
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• pp.32.1-32.20
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• 2022

Sjögren syndrome (SS) is a chronic autoimmune disorder that primarily targets the salivary and lacrimal glands. The pathology of these exocrine glands is characterized by periductal focal lymphocytic infiltrates, and both T cell-mediated tissue injury and autoantibodies that interfere with the secretion process underlie glandular hypofunction. In addition to these adaptive mechanisms, multiple innate immune pathways are dysregulated, particularly in the salivary gland epithelium. Our understanding of the pathogenetic mechanisms of SS has substantially improved during the past decade. In contrast to viral infection, bacterial infection has never been considered in the pathogenesis of SS. In this review, oral dysbiosis associated with SS and evidence for bacterial infection of the salivary glands in SS were reviewed. In addition, the potential contributions of bacterial infection to innate activation of ductal epithelial cells, plasmacytoid dendritic cells, and B cells and to the breach of tolerance via bystander activation of autoreactive T cells and molecular mimicry were discussed. The added roles of bacteria may extend our understanding of the pathogenetic mechanisms and therapeutic approaches for this autoimmune exocrinopathy.

• Clinical and Experimental Pediatrics
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• v.46 no.8
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• pp.758-762
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• 2003

Purpose : Our examination was designed to determine the diagnostic properties of the cutoff point for the prediction of bacteremia in febrile children less than 3 years of age. Cutoff point is the value that simultaneously maximizes both sensitivity and specificity. Methods : We conducted a retrospective study of febrile children, less than 3 years of age, who clinically have no identifiable source of fever. Peripheral blood leukocyte count(WBC), absolute neutrophil count(ANC), erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) were measured at the same time. All patients received blood culture, urine culture and/or CSF culture. Bacterial infection was defined as single pathogen isolated from the CSF or blood or a urinary tract infection (UTI). Patients were dichotomized into two groups : those with bacterial infection and no bacterial infection. We analyzed the characteristics of the children in the two groups. Results : Seventy-one patients(44 males; 27 females) were enrolled in the study. Twenty patients (28%) had a serious bacterial infection(twelve urinary tract infection, five bacteremia, three meningitis) and fifty-one(72%) had no serious bacterial infection. WBC, ESR and CRP were significantly different between the two groups(P<0.05). The cutoff point of WBC, ESR and CRP were $20,000/mm^3$, 30 mm/hr and 3.0 mg/dL, respectively. The sensitivity and specificity of each cutoff point were WBC(75%, 75%), ESR(79%, 68%) and CRP(83%, 77%), respectively. Conclusion : These data show the ability of predictors to identify febrile children less than 3 years of age with bacterial infection. Febrile children who reach the cutoff point must be treated intensively and those who do not reach the cutoff point can be carefully managed without administering antimicrobial agents.

• Pediatric Infection and Vaccine
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• v.23 no.1
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• pp.40-45
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• 2016

Purpose: The purpose of this study was to investigate the etiology of acute pharygotonsillitis in pediatric patients. Methods: Pharyngeal swabs from patients with acute pharyngotonsillitis were evaluated for viruses and bacterial organisms from March 2010 through March 2011. Results: Of 615 patients, potentially pathogenic bacteria were isolated in 40 (6.5%), viruses were isolated in 310 (50.4%), and no pathogens were isolated in 267 patients (43.4%). Both viral and bacterial pathogens were found in 2 (0.3%). Of 40 patients with bacterial pathogens, group A streptococci were found in 31 (77.5%). Among 310 patients with virus infection, adenovirus was the most frequently recovered (203 patients; 65.5%), followed by rhinovirus (65 patients; 21.0%), enterovirus (43 patients; 13.9%) and coronavirus (18 patients; 5.8%). There were 25 patients who had been coinfected with 2 viruses. In viral pharyngotonsillitis, cough, rhinorrhea, conjunctivitis and diarrhea were prominent. On the other hand, pharyngeal injection and pharyngeal petechiae were prominent in bacterial pharyngotonsillitis. Conclusions: Virus infection was a big part of acute pharyngotonsillitis and there were differences in clinical manifestations among viral and bacterial infections. Therefore, we need to distinguish between virus infection and bacterial infection using clinical signs for preventing the abuse of antibiotics.

• Archives of Craniofacial Surgery
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• v.20 no.5
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• pp.324-328
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• 2019

Intraorbital infection shows a low incidence, but it might cause blindness or even death. This case is unusual in that its origin from a craniofacial bone fracture prior to infection of the maxillary sinus. A 33-year-old female patient was referred for right cheek swelling. When she visited the emergency room, we removed right cheek hematoma and bacterial examination was done. In the past, she had craniofacial bone surgical history due to a traffic accident 6 years ago. Next day, the swelling had remained with proptosis and pus was recognized in the conjunctiva. We planned an emergency operation and removed the pus which was already spread inside the orbit. And the evaluation for sinusitis was consulted to the otorhinolaryngology department simultaneously. There were Prevotella oralis and methicillin-resistant Staphylococcus epidermidis bacterial infection in the intraorbital and sinus respectively. Afterwards, the vigorous dressing was done for over a month with intravenous antibiotics. Though the intraorbital infection was resolved, blindness and extraocular movement limitation were inevitable. In conclusion, close follow up of the maxillary sinus in facial bone fracture patients is important and aggressive treatment is needed when an infection is diagnosed.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.197-210
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• 1994

This experiment was carried out to study the cause of degeneration and rot of cultivated mushroom. Among 597 bacterial isolates derived from the rots of Button mushroom (Agaricus bisporus), Oyster mushroom (Pleurotus ostreatus) and Oak mushroom (Lentinus edodes) collected from markets of 5 cities (Seoul, Suwon, Taegu, Pohang and Pusan) in Korea (1991~1993), 111 bacterial isolates (18.5%) were proved as pathogenic bacteria. These pathogenic bacteria causing bacterial rots of cultivated mushrooms were identified as Pseudomonas tolasii, P. agarici, and Eriwinia sp., and the main causal bacteria were P. tolaasii. P. fluorescens and Klebsiella plenticola were confirmed as saprophytic non-pathogenic bacteria. One hundred fifty nine isolates (Group No. 39) of the 486 saprophytic bacterial isolates were classified as P. fluorescens, and this species was most often found rot area of cultivated mushrooms. P. tolaasii, the causal organism of bacterial blotch, was classified into two groups; One group can be differentiated from the other by the formation of white precipitation band by white line reacting organisms of Pseudomonas Agar F media. P. tolaasii attacked the cultivated mushrooms relatively well at lower incubation temperature such as 5$^{\circ}C$, but P. agarici rarely attack at below 1$0^{\circ}C$. The temperature for the infection commercial cultivated mushrooms by P. agarici was higher than that of P. tolaasii. Optimum temperature for the infection of mushrooms by P. tolaasii and P. agarici were 2$0^{\circ}C$ and $25^{\circ}C$, respectively.