• Clinical and Experimental Pediatrics
• /
• v.48 no.5
• /
• pp.461-468
• /
• 2005

The major function of immune system is to protect infections. The immune systems are composed of innate and adaptive immunity. In adaptive immunity, the cellular and humoral components interact each other. Neonates and infants are infected frequently, because immune systems are naive and easy to expose to infectious agents. The complete history and physical examination is essential to evaluate the child with recurrent infections. The environmental risk factors of recurrent infections are day care center, cigarette smoke, and air pollution. The underlying diseases such as immunodeficiency, autoimmune diseases, allergy, and disorders of anatomy or physiology increase the susceptibility to infections. In immunodeficiency, infections are characterized by severe, chronic, recurrent, and unusual microbial agents infection. The defects of antibody production are susceptible to sinopulmonary bacterial infections. T cells defects are vulerable to numerous organisms such as virus, fungi, bacteria and etc. The screening tests for immune functions are the quantitative and qualitative measurements of each immune components. A complete blood count with white blood cell, differential, and platelet provide quantitative informations of immune components. Total complement and immunoglobulin levels represent the humoral component. Antibody levels of previously injected vaccines also provide informations of the antigen specific antibody immune responses. T cell and subsets count is quantitative measurement of cell mediated immunity. Delayed hypersensitivity skin test is a crude measurement of T cell function. The long term outcome of children with recurrent infections is completely dependent on the underlying diseases, the initial time of diagnosis and therapy, continued management, and genetic counscelling.

• BMB Reports
• /
• v.54 no.11
• /
• pp.541-544
• /
• 2021

Protein glycosylation is a common post-translational modification found in all living organisms. This modification in bacterial pathogens plays a pivotal role in their infectious processes including pathogenicity, immune evasion, and host-pathogen interactions. Importantly, many key proteins of host immune systems are also glycosylated and bacterial pathogens can notably modulate glycosylation of these host proteins to facilitate pathogenesis through the induction of abnormal host protein activity and abundance. In recent years, interest in studying the regulation of host protein glycosylation caused by bacterial pathogens is increasing to fully understand bacterial pathogenesis. In this review, we focus on how bacterial pathogens regulate remodeling of host glycoproteins during infections to promote the pathogenesis.

• Parasites, Hosts and Diseases
• /
• v.55 no.5
• /
• pp.513-521
• /
• 2017

Infectious diarrhea is endemic in most developing countries. We aimed to investigate the protozoan, viral, and bacterial causes of acute diarrhea in Taif, Saudi Arabia. A cross-sectional prospective 1-year study was conducted on 163 diarrheal patients of various ages. Stool samples were collected, 1 per patient, and tested for 3 protozoa, 3 viruses, and 9 bacteria with the Luminex Gastrointestinal Pathogen Panel. Overall, 53.4% (87/163) of samples were positives (20.8% protozoa, 19.6% viruses, 2.8% bacteria, and 9.8% mixed). Rotavirus (19.6%), Giardia duodenalis (16.5%), and Cryptosporidium spp. (8.5%) were the mostly detected pathogens. Adenovirus 40/41 (4.2%), Salmonella (3%), Shiga toxin-producing Escherichia coli (3%), and Entamoeba histolytica (2.4%) were also detected. Norovirus GI/II, Vibrio cholerae, Yersinia enterocolitica, and Clostridium difficile toxin A/B were not detected in any patients. All pathogens were involved in coinfections except E. histolytica. Giardia (5.5%) and rotavirus (3%) were the most commonly detected in co-infections. Enterotoxigenic E. coli (2.4%), Campylobacter spp. (2.4%), E. coli 0157 (1.8%), and Shigella spp. (1.2%) were detected in patients only as co-infections. Infections were more in children 0-4 years, less in adults <40 years, and least >40 years, with statistically significant differences in risk across age groups observed with rotavirus (P<0.001), Giardia (P=0.006), and Cryptosporidium (P=0.036) infections. Lastly, infections were not significantly more in the spring. This report demonstrates the high burden of various enteropathogens in the setting. Further studies are needed to define the impact of these findings on the clinical course of the disease.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.20 no.2
• /
• pp.152-157
• /
• 1998

Disturbances of the interrelationship among the host, environment, microorganism will cause the infection clinically. Infection can be classified into bacterial, viral, fungal origin, Bacterial infection is most common due to dental caries, periodontal disease. These infections have the potential to spread via the fascial spaces in the head and neck region. We have undertaken clinical studies on infections in the oral and maxillofacial regions by analyzing 78 hospitalized patients in the Dept. of Oral and Maxillofacial Surgery, Dong-A University Hospital from 1994 to 1997. The results were as fellows; l. Odontogenic infections were most common with the incidence of 84.6%. 2. Considering the number of involved space, single space was 83.3%, double or more space was 16.6%. The most common fascial space involved was submandibular space and followed by buccal space, 3. The most causative organism isolated from the pus cultures was streptococci group 35.4%. 4. Antibiotics were administrated in all cases, and surgical incision and drainage was performed in 87.2%. 5. Combined administration of penicillin and aminoglycoside was most common in 34.6%.. 6. 7 cases were diagnosed as Ludwig's angina and tracheostomy was done in 2 cases of them.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.10
• /
• pp.1730-1735
• /
• 2018

Bacterial pneumonia is one of the most common causes of mortality in Korea. In 2016, the mortality rate from pneumonia was 16,476 deaths per 100,000, which was an 11% increase from the previous year. The aim of our study was to determine the distribution of the bacterial pathogens causing respiratory symptoms in different age groups over a 10-year period. Between January 2008 and September 2017, 1,861 specimens from 1,664 patients admitted to Dankook University Hospital with respiratory symptoms were examined. We used multiplex polymerase chain reaction (PCR) to detect six bacterial pneumonia pathogens: Bordetella pertussis, Chlamydophila pneumoniae, Haemophilus influenzae, Legionella pneumophila, Mycoplasma pneumoniae, and Streptococcus pneumoniae. We detected bacterial pneumonia pathogens in 1,281 (68.83%) specimens. Of the 1,709 pathogens detected, S. pneumoniae was the most common (48.57%; n = 830) followed by H. influenzae (40.08%; n = 685). Most infections were found among children younger than 10 years (92.69%; n = 1,584). Although S. pneumoniae was the most common pathogen detected in all age groups, M. pneumoniae infection increased in prevalence with age (p < 0.05). The rate of co-infection was also high among these patients (31.1%; n = 399), which peaked in 2015 (54.55%; n = 42/77). The prevalence of bacterial pneumonia in Cheonan, along with the proportion of co-infections among patients increased over the 10-year study period. The findings will aid the development of treatment and prevention guidelines.

• Neonatal Medicine
• /
• v.15 no.1
• /
• pp.61-66
• /
• 2008

Purpose : The purpose of this study was to describe the epidemiologic features of febrile illnesses in newborns and to predict the risk of serious infections in this population. Methods : A retrospective study was conducted on 123 full-term infants <30 days of age with an axillary temperature >38$^{\circ}C$ who were hospitalized between 2000 and 2006. Neonates with prenatal risk factors, congenital anomalies, antibiotic administration prior to admission to the hospital, or suspected hospital-acquired infections were excluded. We evaluated the symptoms, physical examination findings, laboratory data, and clinical course between the high- and low-risk groups for serious infections. Results : The high-risk group included 30 infants with the following diagnoses in order of frequency: aseptic meningitis, urinary tract infection, bacterial meningitis, infectious enteritis, sepsis concomitant with disseminated intravascular coagulopathy, bacteremia, pneumonia, cellulitis, and omphalitis. Leukocytosis and thrombocytopenia were statistically different between the two groups. Factors, such as moaning signs, seizures, body temperature, and pulse rate were statistically significant. Conclusion : Unlike previous studies, we included newborns with clinical bacterial infections and aseptic meningitis as the high-risk group. Leukocytosis, thrombocytopenia, moaning signs, seizures, and changes in vital signs were considered useful predictors for identifying febrile neonates at high-risk for serious infections in spite of a difference in the definition of serious infection.

• Childhood Kidney Diseases
• /
• v.19 no.2
• /
• pp.79-88
• /
• 2015

Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as one of the most promising biomarkers of renal epithelial injury. Numerous studies have presented the diagnostic and prognostic utility of urinary and plasma NGAL in patients with acute kidney injury, chronic kidney disease, renal injury after kidney transplantation, and other renal diseases. NGAL is a member of the lipocalin family that is abundantly expressed in neutrophils and monocytes/macrophages and is a mediator of the innate immune response. The biological significance of NGAL to hamper bacterial growth by sequestering iron-binding siderophores has been studied in a knock-out mouse model. Besides neutrophils, NGAL is detectable in most tissues normally encountered by microorganisms, and its expression is upregulated in epithelial cells during inflammation. A growing number of studies have supported the clinical utility of NAGL for detecting invasive bacterial infections. Several investigators including our group have reported that measuring NGAL can be used to help predict and manage urinary tract infections and acute pyelonephritis. This article summarizes the biology and pathophysiology of NGAL and reviews studies on the implications of NGAL in various renal diseases from acute kidney injury to acute pyelonephritis.

• Natural Product Sciences
• /
• v.23 no.4
• /
• pp.286-290
• /
• 2017

Multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa are highly dangerous nosocomial pathogens, cause the symptoms of skin infections, pressure sores, sepsis, blood stream and wound infections. Unfortunately, these pathogens are immune to the most common antibiotics, such as, carbapenem, aminoglycoside and fluoroquinolone. Therefore, it is imperative that new and effective antibiotics be developed. In the present study, the antimicrobial effects of Aloe vera MAP (modified Aloe polysaccharide) on Staphylococcus aureus and Bacillus subtilis, Escherichia coli and Enterobacter aerogenes, and clinical Pseudomonas aeruginosa and clinical Acinetobacter baumannii were comprehensibly investigated. Prior to the growth inhibition effect measurement and antibiotic disc diffusion assay on gram-positive and gram-negative bacteria and selected multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii, antimicrobial resistance screening was performed for the multidrug-resistant bacteria obtained from clinical isolates. The results for showed the Aloe vera MAP had a concentration-dependent effect on all of examined bacteria, particularly on Pseudomonas aeruginosa. Anti-inflammatory and anti-oxidant experiments were also performed dose dependently effects to confirm the beneficial physiological effects of Aloe vera MAP.

• Clinical and Experimental Pediatrics
• /
• v.64 no.11
• /
• pp.543-551
• /
• 2021

The human microbiome, which consists of a collective cluster of commensal, symbiotic, and pathogenic microorganisms living in the human body, plays a key role in host health and immunity. The human nasal cavity harbors commensal bacteria that suppress the colonization of opportunistic pathogens. However, dysbiosis of the nasal microbial community is associated with many diseases, such as acute respiratory infections including otitis media, sinusitis and bronchitis and allergic respiratory diseases including asthma. The nasopharyngeal acquisition of pneumococcus, which exists as a pathobiont in the nasal cavity, is the initial step in virtually all pneumococcal diseases. Although the factors influencing nasal colonization and elimination are not fully understood, the adhesion of opportunistic pathogens to nasopharyngeal mucosa receptors and the eliciting of immune responses in the host are implicated in addition to bacterial microbiota properties and colonization resistance dynamics. Probiotics or synbiotic interventions may show promising and effective roles in the adjunctive treatment of dysbiosis; however, more studies are needed to characterize how these interventions can be applied in clinical practice in the future.

• Parasites, Hosts and Diseases
• /
• v.55 no.2
• /
• pp.129-135
• /
• 2017

A total of 60 samples were collected from 35 swimming pools in Beijing, China, and the presence of Cryptosporidium and Giardia were investigated. The results showed that 16.7% and 15.0% of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively, with a mean concentration of 0.30 oocysts/10 L and 0.27 cysts/10 L. The oocysts and cysts were found to have higher rates of occurrence in August than in May. Genotyping confirmed the presence of Cryptosporidium hominis, C. parvum, and Giardia assemblages A and B, all of which were associated with human infections. The predominant species/assemblages were C. hominis and Giardia assemblage A. Analyses of the relationships between parasite oocysts/cysts, indicator bacteria, and physical-chemical parameters revealed that there was no correlation between 2 parasites and fecal bacterial indicators, whilst there was a significant correlation between protozoa and urea concentration, which indicates that urea concentration rather than fecal bacterial indicators might be an appropriate index for chlorine-resistant protozoa in swimming pools. This study provides useful information to improve the safety of swimming pool water and deduce the risk of protozoan infections.