Comparison of the Incidence and Clinical Characteristics of Gram-positive and Gram-negative Surgical Site Infections after Gastric Surgery / 감염과화학요법

BACKGROUND: Surgical site infection (SSI) is prominent among the total incidence of healthcare-associated infections, and is a major contributing factor in the trend of increasing medical costs. There have been numerous efforts to analyze the conditions and causes of SSI for the purpose of prevention. In this study of SSI development after gastric surgery, we evaluated the prevalence of specific pathogens and compared the clinical characteristics observed between gram-positive (GPB) and gram-negative bacteria (GNB). MATERIALS AND METHODS: We conducted a retrospective study of patients who developed SSI within 30 days after gastric surgery at 13 clinics in Korea, between January 2007 and December 2008. Only those cases of SSI which included confirmed pathogen were included in this study. RESULTS: Among the 121 patients who developed SSI, GPB were observed in 32 patients and 36 cases, and GNB were isolated in 32 patients and 36 cases. Methicillin resistant Staphylococcus aureus (MRSA) was the most frequently isolated pathogen in this analysis. There were no differences observed between the GPB and GNB group in terms of baseline characteristics, patient or procedure related risk factors, or factors associated with prophylactic antibiotics. CONCLUSIONS: In the previous studies of the occurrence of SSI after gastric surgery, it was reported that the majority of observed pathogens were enteric GNB. Further studies of the incidence of SSI after gastric surgery, particularly those related to MRSA infection, are necessary.

The Characteristics of Metallo-beta-Lactamase-Producing Gram-Negative Bacilli Isolated from Sputum and Urine: A Single Center Experience in Korea

Metallo-beta-lactamase (MBL) production usually results in high-level resistance to most beta-lactams, and a rapid spread of MBL producing major gram-negative pathogens is a matter of particular concern worldwide. However, clinical data are scarce and most studies compared MBL producer (MP) with MBL non-producer (MNP) strains which included carbapenem susceptible isolates. Therefore, we collected clinical data of patients in whom imipenem-nonsusceptible Pseudomonas aeruginosa (PA) and Acinetobacter baumannii (AB) were isolated from sputum or urine, and investigated MBL production and the risk factors related with MBL acquisition. The antimicrobial susceptibility patterns were also compared between MPs and imipenem-nonsusceptible MNPs (INMNP). Among the 176 imipenem-nonsusceptible isolates, 12 MPs (6.8%) were identified. There was no identifiable risk factor that contributed to the acquisition of MPs when compared to INMNPs, and case-fatalities were not different between the two groups. The percentage of susceptible isolates was higher among MPs for piperacilin/tazobactam and fluoroquinolones while that of ceftazidime was higher in INMNPs (p < 0.05). As regards to aztreonam, which has been known to be a uniquely stable beta-lactam against MBLs, susceptibility was preserved in only two isolates (16.7%) among MPs, and was not higher than that of INMNPs (23.2%). In conclusion, the contribution of MBLs to imipenem non-susceptibility in PA/ABs isolated from sputum and urine was relatively limited, and there was no significant risk factor associated with acquisition of MPs compared with INMNPs. However, limited susceptibility to aztreonam implies that MPs may hold additional resistance mechanisms, such as extended spectrum beta-lactamases, AmpC beta-lactamases, or other non-enzymatic mechanisms.

Disseminated Mycobacterium kansasii Infection Associated with Skin Lesions: A Case Report and Comprehensive Review of the Literature

Mycobacteruim kansasii occasionally causes disseminated infection with poor outcome in immunocompromised patients. We report the first case of disseminated M. kansasii infection associated with multiple skin lesions in a 48-yr-old male with myelodysplastic syndrome. The patient continuously had taken glucocorticoid during 21 months and had multiple skin lesions developed before 9 months without complete resolution until admission. Skin and mediastinoscopic paratracheal lymph node (LN) biopsies showed necrotizing granuloma with many acid-fast bacilli. M. kansasii was cultured from skin, sputum, and paratracheal LNs. The patient had been treated successfully with isoniazid, rifampin, ethmabutol, and clarithromycin, but died due to small bowel obstruction. Our case emphasizes that chronic skin lesions can lead to severe, disseminated M. kansasii infection in an immunocompromised patient. All available cases of disseminated M. kansasii infection in non HIV-infected patients reported since 1953 are comprehensively reviewed.

A Case of Guillain-Barre Syndrome Following Plasmodium vivax infection / 감염과화학요법

A 28-year-old male was admitted to our medical center with general myalgia and fever. After a series of tests, he was diagnosed with P. vivax malaria. On the 5th hospital day, the patient complained of tingling sensation on both hands and feet, which acutely progressed to ascending symmetric motor paralysis. Nerve conduction velocity test and cerebrospinal fluid analysis showed albumino-cytologic dissociation, suggesting polyradiculopathy, and thus he was diagnosed with Guillain-Barre syndrome. After 5-day treatment with intravenous immunoglobulin, and antificial ventilator therapy the patient fully recovered. In the literature, only 22 cases of Guillain-Barre syndrome associated with Plasmodium have been reported; 19 cases were caused by Plasmodium falciparum and 3 were by P. vivax. Herein, we report the first case of Guillain-Barre Syndrome associated with P. vivax malaria in Korea.

A Case of Pyelonephritis Accompanied by Enterococcus hirae Bacteremia / 감염과화학요법

Enterococcus hirae infection is rare in humans. We describe a case of pyelonephritis that was caused by Enterococcus hirae in a 57-year-old woman. E. hirae was isolated from both blood and urine. This is the 2nd case report on bacteremia caused by E. hirae in Korea.

A Case of Pyelonephritis Accompanied by Enterococcus hirae Bacteremia / 감염과화학요법

Enterococcus hirae infection is rare in humans. We describe a case of pyelonephritis that was caused by Enterococcus hirae in a 57-year-old woman. E. hirae was isolated from both blood and urine. This is the 2nd case report on bacteremia caused by E. hirae in Korea.

Blood Stream Infections by Candida glabrata and Candida krusei: A Single-Center Experience

BACKGROUND/AIMS: The increasing incidence of Candida glabrata and Candida krusei infections is a significant problem because they are generally more resistant to fluconazole. We compared the risk factors associated with C. glabrata and C. krusei fungemia with Candida albicans fungemia and examined the clinical manifestations and prognostic factors associated with candidemia. METHODS: We retrospectively reviewed demographic data, risk factors, clinical manifestations, and outcomes associated with C. glabrata and C. krusei fungemia at a tertiary-care teaching hospital during a 10-years period from 1997 to 2006. RESULTS: During the study period, there were 497 fungemia episodes. C. glabrata fungemia accounted for 23 episodes and C. krusei fungemia accounted for 8. Complete medical records were available for 27 of these episodes and form the basis of this study. Compared to 54 episodes of C. albicans fungemia, renal insufficiency and prior fluconazole prophylaxis were associated with development of C. glabrata or C. krusei fungemia. The overall mortality was 67%. The fungemia-related mortality of C. glabrata and C. krusei was higher than that of C. albicans (52 vs. 26%, p=0.021). Empirical antifungal therapy did not decrease the crude mortality. Multiple logistic regression analysis showed that high APACHE II scores, catheter maintenance, and shock were independently associated with an increased risk of death. CONCLUSIONS: Renal insufficiency and prior fluconazole prophylaxis were associated with the development of C. glabrata or C. krusei fungemia. Fungemia-related mortality of C. glabrata or C. krusei was higher than that of C. albicans. Outcomes appeared to be related to catheter removal, APACHE II scores, and shock.

Diagnosis and Species Identification of Mycobacterial Infections by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Analysis of Sterile Body Fluids

BACKGROUND/AIMS: The development of effective, accurate, and rapid diagnostic methods for Mycobacterium infection and mycobacterial species identification is required. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is an easy, rapid and inexpensive technique for identifying Mycobacterium spp. METHODS: We performed PCR-RFLP to detect and identify Mycobacterium spp. from 10 sterile body fluids, including ascites, cerebrospinal fluid, pleural fluid, synovial fluid, and peritoneal dialysis fluid. Clinical samples were collected from patients with diagnoses of definite, probable or suspected mycobacterial infection. The conserved RNA polymerase genes of Mycobacterium spp. were amplified by PCR. RESULTS: The amplified 360-bp region of rpoB was digested with the restriction enzyme MspI or HaeIII. The PCRRFLP results for the clinical samples were identical to those for M. tuberculosis, M. fortuitum, M. intracellulare, and M. avium. In addition, the results of the PCR-RFLP were identical to those obtained by DNA sequencing. CONCLUSIONS: PCR-RFLP analysis of sterile body fluids may be a useful method for the diagnosis of mycobacterial infections and for the differentiation of mycobacterial species.

Factors Associated with HIV-1 Proviral DNA Loads in Patients with Undetectable Plasma RNA Load

To evaluate factors associated with human immunodeficiency virus type 1 (HIV-1) proviral DNA load, we conducted a cross-sectional study of 36 chronically HIV-1- infected individuals with undetectable plasma viral RNA. We used real-time polymerase chain reaction to determine the number of HIV-1 proviral DNA copies per 10(6) peripheral blood mononuclear cells. The mean level of plasma viral RNA when the CD4+ T cell count was above 500 cells/microliter without highly active antiretroviral therapy (HAART) was significantly associated with proviral DNA load at the time of undetectable plasma HIV RNA with HAART. Strategies to reduce the level of plasma viral RNA when patients' CD4+ T cell counts are above 500 cells/microliter without HAART could help reduce HIV-1 proviral DNA load.

Utility of QuantiFERON-TB In-Tube Test for Differentiating Active Tuberculosis from Latent Tuberculosis Infection in an Intermediate Burden Country / 감염과화학요법

BACKGROUND: The aim of the present study was to assess the contribution of a QuantiFERON-TB Gold In-Tube test (QFT-IT) in differentiating active tuberculosis (TB) from latent tuberculosis infection (LTBI) by quantifying interferon-gamma levels. MATERIALS AND METHODS: We retrospectively reviewed clinical records of 314 patients older than 15 years who had performed QFT-IT between July 2006 and August 2007 at a tertiary care teaching hospital. RESULTS: Subjects with active TB (n=81, culture confirmed active TB in 40 subjects) and LTBI (n=76) were included. Mean+/-SD IFN-gamma levels were 4.96+/-3.98 IU/mL (range -0.08-10) for all subjects with active TB, 4.54+/-4.05 IU/mL (range -0.08-10) for culture confirmed active TB, and 4.11+/-3.57 IU/mL (range 0.35-10) for subjects with LTBI. The quantitative results of QFT-IT on IFN-gamma levels between all the subjects with active TB and those with LTBI were not statistically significant (P=0.16). The result was similar when compared between those with culture confirmed active TB and those with LTBI, showing little statistical significance (P=0.554). CONCLUSION: The production of IFN-gamma measured by QFT-IT showed no correlation between its level and the activity of Mycobacterium tuberculosis infection. These results suggest that measuring IFN-gamma using QFT-IT might not be useful for distinguishing active TB from LTBI.

Efficacy of the Arbekacin and Teicoplanin Combination on Glycopeptide Intermediate Staphylococcus aureus in a Rabbit Model of Endocarditis / 감염과화학요법

BACKGROUND: There have been no reports to evaluate the usefulness of combination therapy with glycopeptide and arbekacin in endocarditis by in vivo model. MATERIALS AND METHODS: We investigated the efficacy of the arbekacin and teicoplanin combination on glycopeptide intermediate Staphylococcus aureus (GISA) in rabbit model of endocardits. GISA Mu50 strain was used for the experiment. The rabbit model of aortic valve endocarditis as described previously was used. Treatment was started 20h later inoculation with teicoplanin alone (at 20 mg/kg of body weight intramuscularly every 12 hours for 4 days after loading dose of 40 mg/kg of body weight intramuscularly), arbekacin alone (5 mg/kg of body weight intramuscularly every 12h for 4 days), or teicoplanin plus arbekacin. The results of therapy for experimental endocarditis due to Mu50 showed that teicoplanin and arbekacin combination was more effective than the administration of both drugs alone in reducing the log10CFU/g of aortic vegetation (P<0.05). CONCLUSION: The combination of teicoplanin and arbekacin was more effective against GISA (Mu50) than both drugs alone in vivo endocarditis model.

Efficacy of the Arbekacin and Teicoplanin Combination on Glycopeptide Intermediate Staphylococcus aureus in a Rabbit Model of Endocarditis / 감염과화학요법

BACKGROUND: There have been no reports to evaluate the usefulness of combination therapy with glycopeptide and arbekacin in endocarditis by in vivo model. MATERIALS AND METHODS: We investigated the efficacy of the arbekacin and teicoplanin combination on glycopeptide intermediate Staphylococcus aureus (GISA) in rabbit model of endocardits. GISA Mu50 strain was used for the experiment. The rabbit model of aortic valve endocarditis as described previously was used. Treatment was started 20h later inoculation with teicoplanin alone (at 20 mg/kg of body weight intramuscularly every 12 hours for 4 days after loading dose of 40 mg/kg of body weight intramuscularly), arbekacin alone (5 mg/kg of body weight intramuscularly every 12h for 4 days), or teicoplanin plus arbekacin. The results of therapy for experimental endocarditis due to Mu50 showed that teicoplanin and arbekacin combination was more effective than the administration of both drugs alone in reducing the log10CFU/g of aortic vegetation (P<0.05). CONCLUSION: The combination of teicoplanin and arbekacin was more effective against GISA (Mu50) than both drugs alone in vivo endocarditis model.

Utility of QuantiFERON-TB In-Tube Test for Differentiating Active Tuberculosis from Latent Tuberculosis Infection in an Intermediate Burden Country / 감염과화학요법

BACKGROUND: The aim of the present study was to assess the contribution of a QuantiFERON-TB Gold In-Tube test (QFT-IT) in differentiating active tuberculosis (TB) from latent tuberculosis infection (LTBI) by quantifying interferon-gamma levels. MATERIALS AND METHODS: We retrospectively reviewed clinical records of 314 patients older than 15 years who had performed QFT-IT between July 2006 and August 2007 at a tertiary care teaching hospital. RESULTS: Subjects with active TB (n=81, culture confirmed active TB in 40 subjects) and LTBI (n=76) were included. Mean+/-SD IFN-gamma levels were 4.96+/-3.98 IU/mL (range -0.08-10) for all subjects with active TB, 4.54+/-4.05 IU/mL (range -0.08-10) for culture confirmed active TB, and 4.11+/-3.57 IU/mL (range 0.35-10) for subjects with LTBI. The quantitative results of QFT-IT on IFN-gamma levels between all the subjects with active TB and those with LTBI were not statistically significant (P=0.16). The result was similar when compared between those with culture confirmed active TB and those with LTBI, showing little statistical significance (P=0.554). CONCLUSION: The production of IFN-gamma measured by QFT-IT showed no correlation between its level and the activity of Mycobacterium tuberculosis infection. These results suggest that measuring IFN-gamma using QFT-IT might not be useful for distinguishing active TB from LTBI.

Clinical manifestations for diabetes mellitus in HIV-infected Koreans on highly active antiretroviral therapy / 대한내과학회지

BACKGROUND/AIMS: The introduction of highly active antiretroviral therapy (HAART) has significantly modified the course of HIV infection. However, the HAART regimens, and especially those including protease inhibitors (PIs), have been shown to cause diabetes mellitus. We evaluated the incidence and clinical manifestations of HIV-infected Koreans who received HAART and the risk factors for diabetes mellitus in those patients. METHODS: We conducted a retrospective cohort study and a case-control study to evaluate the clinical manifestations, the incidence and the risk factors for diabetes mellitus in 215 HIV-infected patients who were on HAART at Yonsei University College of Medicine from 1991 to 2006. RESULTS: 215 patients were analyzed and the total duration of follow up was 1079 person-years. The incidences of diabetes mellitus and impaired fasting glucose were 1.39 case/100person-years and 6.02 case/100person-years. Most of the cases were non-obese type II diabetes and these patients showed insulin resistance and impaired beta cell function. On the risk factor analysis, the factors contributing to the development of diabetes were age, a decrease of the viral load and indinavir use. CONCLUSIONS: In our study, the incidence of diabetes among Korean HIV-positive patients on HAART was 1.39case/100person-years. Age, a decrease of the viral load and indinavir use were the risk factors for development of diabetes mellitus.

Two Cases of Multidrug-Resistant Human Immunodeficiency Virus Infection Treated with Atazanavir and Lopinavir/Ritonavir Combination Therapy

The combination of atazanavir (ATV) and lopinavir/ritonavir (LPV/RTV) with nucleoside reverse transcriptase inhibitors (NRTI) has been used as a salvage regimen for human immunodeficiency virus (HIV)-positive patients. In this paper, we discuss two cases of HIV-positive patients who had long histories of virological failure following a heavy treatment of antiretroviral drugs, but then achieved virological suppression with double-boosted protease inhibitor (PI) regimens. In patients with multiple genotypic resistance to PIs and NRTIs, virological suppression can be achieved with a combination of ATV plus LPV/RTV with an NRTI backbone. The two cases in this report suggest that a combination of ATV plus LPV/RTV could be a useful salvage regimen for the subset of HIV-positive patients with limited treatment options.

A Case of Agrobacterium radiobacter Sepsis following Oral Surgery in a Patient of Oral Cancer / 감염과화학요법

Agrobacterium is an aerobic, motile, oxidase-positive, and non-spore-forming gram-negative bacillus. Under laboratory conditions, Agrobacterium can genetically transform a wide range of other eukaryotic species. A plant-pathogenic soil inhabitant, Agrobacterium radiobacter is not characterized as a true human pathogen. It is an opportunistic pathogen of minor clinical significance and has been substantiated as a rare cause of bacteremia, endocarditis, urinary tract infection and peritonitis mostly in catheterized immunocompromised patients. The authors report a case of a 41-year-old female patient with sepsis caused by A. radiobacter bacteremia following wide excisional biopsy of adenoid-cystic carcinoma involving oral cavity. She was suffering from fever and chilling that developed on second post-operation day. Blood cultures yielded a gram-negative bacillus identified as A. radiobacter. She completely recovered with appropriate antibiotics treatment; levofloxacin and isepamicin. We experienced a case of sepsis due to A. radiobacter bacteremia without indwelling foreign body, which was treated successfully with antibiotics therapy.

A Case of Agrobacterium radiobacter Sepsis following Oral Surgery in a Patient of Oral Cancer / 감염과화학요법

Agrobacterium is an aerobic, motile, oxidase-positive, and non-spore-forming gram-negative bacillus. Under laboratory conditions, Agrobacterium can genetically transform a wide range of other eukaryotic species. A plant-pathogenic soil inhabitant, Agrobacterium radiobacter is not characterized as a true human pathogen. It is an opportunistic pathogen of minor clinical significance and has been substantiated as a rare cause of bacteremia, endocarditis, urinary tract infection and peritonitis mostly in catheterized immunocompromised patients. The authors report a case of a 41-year-old female patient with sepsis caused by A. radiobacter bacteremia following wide excisional biopsy of adenoid-cystic carcinoma involving oral cavity. She was suffering from fever and chilling that developed on second post-operation day. Blood cultures yielded a gram-negative bacillus identified as A. radiobacter. She completely recovered with appropriate antibiotics treatment; levofloxacin and isepamicin. We experienced a case of sepsis due to A. radiobacter bacteremia without indwelling foreign body, which was treated successfully with antibiotics therapy.

A Case of Progressive Multifocal Leukoencephalopathy in a Patient with Acquired Immune Deficiency Syndrome / 감염과화학요법

In Korea, as the prevalence of acquired immune deficiency syndrome (AIDS) increases, various opportunistic infections are becoming a problem. Progressive multifocal leukoencephalopathy (PML) is postulated to be associated with impaired cellular immunity and can be more frequently encountered these days primarily due to increasing incidence of AIDS. Neurologic deficits and brain imaging study together strongly suggest PML, but confirmatory diagnosis can be made only by cerebrospinal fluid study or tissue biopsy. In Korea few cases of confirmed PML in AIDS patients have been reported, and herein we offer our experience of a case of PML who underwent brain biopsy for confirmative diagnosis.

A Case of Progressive Multifocal Leukoencephalopathy in a Patient with Acquired Immune Deficiency Syndrome / 감염과화학요법

In Korea, as the prevalence of acquired immune deficiency syndrome (AIDS) increases, various opportunistic infections are becoming a problem. Progressive multifocal leukoencephalopathy (PML) is postulated to be associated with impaired cellular immunity and can be more frequently encountered these days primarily due to increasing incidence of AIDS. Neurologic deficits and brain imaging study together strongly suggest PML, but confirmatory diagnosis can be made only by cerebrospinal fluid study or tissue biopsy. In Korea few cases of confirmed PML in AIDS patients have been reported, and herein we offer our experience of a case of PML who underwent brain biopsy for confirmative diagnosis.

A Case of Lactic Acidosis Caused by Stavudine in an AIDS Patient

Nucleoside reverse transcriptase inhibitors (NRTIs), which are used for the treatment of human immunodeficiency virus (HIV) infection have been associated with a wide spectrum of clinical manifestations, including hepatic steatosis, lipodystrophy, myopathy, and lactic acidosis. Such adverse effects are postulated to result from the inhibition of mitochondrial DNA gamma polymerase, which causes the depletion of mitochondrial DNA and eventual the disruption of oxidative phosphorylation. Although cases of severe decompensated lactic acidosis are rare, this syndrome is associated with a high mortality rate. We report upon the first Korean case, of severe lactic acidosis in an acquired immunodeficiency syndrome (AIDS) patient receiving stavudine, an anti-HIV drug.