De Novo Superinfection of Hepatitis B Virus in an Anti-HBs Positive Patient with Recurrent Hepatitis C Following Liver Transplantation

A 60-year-old woman with end stage liver cirrhosis caused by genotype 2 hepatitis C virus (HCV) infection received an orthotopic liver transplantation (OLT). The patient was negative for the hepatitis B surface antigen (HBsAg) and positive for the anti-hepatitis B surface antibody (anti-HBs) prior to and one and a half months following the OLT. Due to reactivation of hepatitis C, treatment with interferon-alpha and Ribavirin started two months following the OLT and resulted in a sustained virological response. We performed a liver biopsy because a biochemical response was not achieved. Surprisingly, liver pathology showed HBsAg-positive hepatocytes with a lobular hepatitis feature, which had been negative in the liver biopsy specimen obtained one and a half months post-OLT. High titers of both HBsAg and HBeAg were detected, while anti-HBs antibodies were not found. Tests for IgM anti-hepatitis B core antibody and anti-delta virus antibodies were negative. The serum HBV DNA titer was over 1×107 copies/mL. A sequencing analysis showed no mutation in the "a" determinant region, but revealed a mixture of wild and mutant strains at an overlapping region of the S and P genes (S codon 213 (Leu/Ile); P codons 221 (Phe/Tyr) and 222 (Ala/Thr)). These findings suggest that de novo hepatitis B can develop in patients with HCV infection during the post-OLT period despite the presence of protective anti-HBs

Community-Acquired versus Nosocomial Klebsiella pneumoniae Bacteremia: Clinical Features, Treatment Outcomes, and Clinical Implication of Antimicrobial Resistance

We conducted this study to compare clinical features, outcomes, and clinical implication of antimicrobial resistance in Klebsiella pneumoniae bacteremia acquired as community vs. nosocomial infection. A total of 377 patients with K. pneumoniae bacteremia (191 community-acquired and 186 nosocomial) were retrospectively analyzed. Neoplastic diseases (hematologic malignancy and solid tumor, 56%) were the most commonly associated conditions in patients with nosocomial bacteremia, whereas chronic liver disease (35%) and diabetes mellitus (20%) were the most commonly associated conditions in patients with community-acquired bacteremia. Bacteremic liver abscess occurred almost exclusively in patients with community-acquired infection. The overall 30-day mortality was 24% (91/377), and the mortality of nosocomial bacteremia was significantly higher than that of community-acquired bacteremia (32% vs. 16%, p<0.001). Of all community-acquired and nosocomial isolates, 4% and 33%, respectively, were extended-spectrum cephalosporin (ESC)-resistant, and 4% and 21%, respectively, were ciprofloxacin (CIP)-resistant. In nosocomial infections, prior uses of ESC and CIP were found to be independent risk factors for ESC and CIP resistance, respectively. Significant differences were identified between community-acquired and nosocomial K. pneumoniae bacteremia, and the mortality of nosocomial infections was more than twice than that of community-acquired infections. Antimicrobial resistance was a widespread nosocomial problem and also identified in community-acquired infections

Usefulness of the procalcitonin test in young febrile infants between 1 and 3 months of age

Purpose To study the usefulness of the procalcitonin (PCT) test in young febrile infants between 1 and 3 months of age. Methods We evaluated the medical records of 336 febrile infants between 1 and 3 months of age who visited the Emergency Department or outpatient department of Samsung Changwon Hospital from May 2015 to February 2017, and analyzed the clinical characteristics between infants in the serious bacterial infection (SBI) group and non-SBI group. Results Among the 336 infants, 38 (11.3%) had definitive SBI (bacteremia, n=3; meningitis, n=1; urinary tract infection, n=34). The mean PCT (6.4±11.9 ng/mL) and C-reactive protein (CRP) level (3.8±2.6 mg/dL), and the absolute neutrophil count (ANC) (6,984±4,675) for patients in the SBI group were significantly higher than those for patients in the non-SBI group (PCT, 0.3±1.2 ng/mL; CRP, 1.3±1.6 mg/dL; ANC, 4,888±3,661). PCT had lower sensitivity (43.6%), but higher specificity (92.6%) and accuracy (86.9%) than CRP (92.3%, 25.3%, and 33.0%) for identifying SBI. The area under the receiver operating characteristic curves (AUCs) for definitive SBI were PCT 77.0%, CRP 80.8%, WBC 56.8%, ANC 67.8%, and PLT 48.1%. The AUCs for definitive SBI were PCT+CRP 85.4%, PCT+WBC 77.2%, PCT+ANC 81.3%, CRP+WBC 80.1%, and CRP+ANC 81.6%. Conclusion Our results suggest that the PCT test or a combination of PCT and CRP tests is a more accurate and specific biomarker to detect and rule out SBIs

In vitro ability of Staphylococcus aureus isolates from bacteraemic patients with and without metastatic complications to invade vascular endothelial cells

Invasion of vascular endothelial cells is thought to be a critical step in the development of metastatic infections in patients with Staphylococcus aureus bacteraemia. This study was designed to evaluate the association between the ability to invade endothelial cells and metastatic infection by S. aureus. Patients with metastatic infection were identified among those with community-acquired S. aureus bacteraemia in a tertiary referral hospital. Patients with simple bacteraemia caused by S. aureus over the same period served as the control group. The ability of each clinical isolate to invade endothelial cells was evaluated by counting the number of intracellular organisms 1 h after inoculation onto human umbilical vein endothelial cells in vitro. The cytotoxic activity of intracellular S. aureus was determined 24 h after internalization, and expressed as the percentage of cells killed. The clinical isolates varied in invasiveness and cytotoxicity. The median invasiveness, relative to S. aureus reference strain ATCC 29213, was 145 % in the cases (n=10) [interquartile range (IQR) 103-160] and 153 % (IQR 111-173) in the controls (n=11; P=0.44). The median cytotoxicity was 59.4 % (IQR 47-68) in the cases and 65.2 % (IQR 50-74) in the controls (P=0.44). Differences in the ability of S. aureus to invade and destroy vascular endothelial cells in vitro were not associated with the development of metastatic complications in patients with S. aureus bacteraemia. This implies that the invasiveness and toxicity of S. aureus for endothelial cells may not be major determinants of metastatic infection.The work was supported by grant no. 02-05-026 from the research fund of Seoul National University Bundang Hospital

Genetic Traceability of Black Pig Meats Using Microsatellite Markers

Pork from Jeju black pig (population J) and Berkshire (population B) has a unique market share in Korea because of their high meat quality. Due to the high demand of this pork, traceability of the pork to its origin is becoming an important part of the consumer demand. To examine the feasibility of such a system, we aim to provide basic genetic information of the two black pig populations and assess the possibility of genetically distinguishing between the two breeds. Muscle samples were collected from slaughter houses in Jeju Island and Namwon, Chonbuk province, Korea, for populations J and B, respectively. In total 800 Jeju black pigs and 351 Berkshires were genotyped at thirteen microsatellite (MS) markers. Analyses on the genetic diversity of the two populations were carried out in the programs MS toolkit and FSTAT. The population structure of the two breeds was determined by a Bayesian clustering method implemented in structure and by a phylogenetic analysis in Phylip. Population J exhibited higher mean number of alleles, expected heterozygosity and observed heterozygosity value, and polymorphism information content, compared to population B. The FIS values of population J and population B were 0.03 and −0.005, respectively, indicating that little or no inbreeding has occurred. In addition, genetic structure analysis revealed the possibility of gene flow from population B to population J. The expected probability of identify value of the 13 MS markers was 9.87×10−14 in population J, 3.17×10−9 in population B, and 1.03×10−12 in the two populations. The results of this study are useful in distinguishing between the two black pig breeds and can be used as a foundation for further development of DNA markers

Salvage Treatment for Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia: Efficacy of Linezolid With or Without Carbapenem

Background. Persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is associated with high mortality rates, but no treatment strategy has yet been established. We performed this study to evaluate the efficacy of linezolid with or without carbapenem in salvage treatment for persistent MRSA bacteremia. Methods. All adult patients with persistent MRSA bacteremia for >= 7 days from January 2006 through March 2008 who were treated at Seoul National University Hospital were studied. The results of linezolid salvage therapy with or without carbapenem were compared with those of salvage therapy with vancomycin plus aminoglycosides or rifampicin. Results. Thirty-five patients with persistent MRSA bacteremia were studied. The early microbiological response (ie, negative results for follow-up blood culture within 72 hours) was significantly higher in the linezolid-based salvage therapy group than the comparison group (75% vs 17%; P = .006). Adding aminoglycosides or rifampicin to vancomycin was not successful in treating any of the patients, whereas linezolid-based therapy gave an 88% salvage success rate (P < .001). The S. aureus-related mortality rate was lower for patients treated with a linezolid salvage regimen than for patients continually treated with a vancomycin-based regimen (13% vs 53%; P = .030). Conclusions. Linezolid-based salvage therapy effectively eradicated S. aureus from the blood for patients with persistent MRSA bacteremia. The salvage success rate was higher for linezolid therapy than for vancomycin-based combination therapy.Jenkins TC, 2008, CLIN INFECT DIS, V46, P1000, DOI 10.1086/529190Falagas ME, 2008, LANCET INFECT DIS, V8, P53, DOI 10.1016/S1473-3099(07)70312-2Hawkins C, 2007, ARCH INTERN MED, V167, P1861Kollef MH, 2007, CLIN INFECT DIS, V45, pS191, DOI 10.1086/519470Micek ST, 2007, CLIN INFECT DIS, V45, pS184, DOI 10.1086/519471*CLIN LAB STAND I, 2007, M100S17 CLIN LAB STAHidayat LK, 2006, ARCH INTERN MED, V166, P2138Howden BP, 2006, ANTIMICROB AGENTS CH, V50, P3039, DOI 10.1128/AAC.00422-06Hageman JC, 2006, CLIN INFECT DIS, V43, pE42Jacqueline C, 2006, ANTIMICROB AGENTS CH, V50, P2547, DOI 10.1128/AAC.01501-05Sakoulas G, 2006, CLIN INFECT DIS, V42, pS40Jones RN, 2006, CLIN INFECT DIS, V42, pS13Khatib R, 2006, SCAND J INFECT DIS, V38, P7, DOI 10.1080/00365540500372846Wu VC, 2006, CLIN INFECT DIS, V42, P66Jacqueline C, 2005, ANTIMICROB AGENTS CH, V49, P45, DOI 10.1128/AAC.49.1.45-51.2005*CDCP, 2005, CA MRSA CLIN FAQS CDFowler VG, 2004, J INFECT DIS, V190, P1140Wisplinghoff H, 2004, CLIN INFECT DIS, V39, P309, DOI 10.1086/421946Khosrovaneh A, 2004, CLIN INFECT DIS, V38, P1328Howden BP, 2004, CLIN INFECT DIS, V38, P521KIM SH, 2004, 42 ANN M INF DIS SOC, P142Fowler VG, 2003, ARCH INTERN MED, V163, P2066Kim SH, 2003, CLIN INFECT DIS, V37, P794Moise PA, 2002, J ANTIMICROB CHEMOTH, V50, P1017, DOI 10.1093/jac/dkf215Li JS, 2000, CLIN INFECT DIS, V30, P633You I, 2000, DIAGN MICR INFEC DIS, V36, P37Lowy FD, 1998, NEW ENGL J MED, V339, P520Hiramatsu K, 1997, LANCET, V350, P1670LIBMAN H, 1984, ARCH INTERN MED, V144, P5411

Risk factors for and clinical outcomes of carbapenem non-susceptible gram negative bacilli bacteremia in patients with acute myelogenous leukemia

Background Carbapenem is frequently used when gram negative bacilli (GNB) bacteremia is detected especially in neutropenic patients. Consequently, appropriate treatment could be delayed in GNB bacteremia cases involving organisms which are not susceptible to carbapenem (carba-NS), resulting in a poor clinical outcomes. Here, we explored risk factors for carba-NS GNB bacteremia and its clinical outcomes in patients with acute myelogenous leukemia (AML) that underwent chemotherapy. Methods We reviewed all GNB bacteremia cases that occurred during induction or consolidation chemotherapy, over a 15-year period, in a tertiary-care hospital. Results Among 489 GNB bacteremia cases from 324 patients, 45 (9.2%) were carba-NS and 444 (90.8%) were carbapenem susceptible GNB. Independent risk factors for carba-NS GNB bacteremia were: carbapenem use at bacteremia onset (adjusted odds ratio [aOR]: 91.2; 95% confidence interval [95%CI]: 29.3–284.1; P < 0.001); isolation of carbapenem-resistant Acinetobacter baumannii (aOR: 19.4, 95%CI: 3.4–112.5; P = 0.001) in the prior year; and days from chemotherapy to GNB bacteremia (aOR: 1.1 per day, 95%CI: 1.1–1.2; P < 0.001). Carba-NS bacteremia was independently associated with in-hospital mortality (aOR: 6.6, 95%CI: 3.0–14.8; P < 0.001). Conslusion Carba-NS organisms should be considered for antibiotic selection in AML patients having these risk factors

Toll-like receptor 2 downregulation and cytokine dysregulation predict mortality in patients with Staphylococcus aureus bacteremia

Background Staphylococcus aureus bacteremia (SAB) presents heterogeneously, owing to the differences in underlying host conditions and immune responses. Although Toll-like receptor 2 (TLR2) is important in recognizing S. aureus, its function during S. aureus infection remains controversial. We aimed to examine the association of TLR2 expression and associated cytokine responses with clinical SAB outcomes. Methods Patients from a prospective SAB cohort at two tertiary-care medical centers were enrolled. Blood was sampled at several timepoints (≤5 d, 6–9 d, 10–13 d, 14–19 d, and ≥ 20 d) after SAB onset. TLR2 mRNA levels were determined via real-time PCR and serum tumor necrosis factor [TNF]-α, interleukin [IL]-6, and IL-10 levels were analyzed with multiplex-high-sensitivity electrochemiluminescent ELISA. Results TLR2 levels varied among 59 SAB patients. On days 2–5, TLR2 levels were significantly higher in SAB survivors than in healthy controls (p = 0.040) and slightly but not significantly higher than non-survivors (p = 0.120), and SAB patients dying within 7 d had lower TLR2 levels than survivors (P = 0.077) although statistically insignificant. IL-6 and IL-10 levels were significantly higher in non-survivors than in survivors on days 2–5 post-bacteremia (P = 0.010 and P = 0.021, respectively), and those dying within 7 d of SAB (n = 3) displayed significantly higher IL-10/TNF-α ratios than the survivors did (P = 0.007). Conclusion TLR2 downregulation and IL-6 and IL-10 concentrations suggestive of immune dysregulation during early bacteremia may be associated with mortality from SAB. TLR2 expression levels and associated cytokine reactions during early-phase SAB may be potential prognostic factors in SAB, although larger studies are warranted.This study was supported by a research grant (13–2014-002) from Seoul National University Bundang Hospital (Seongnam, South Korea). The funder had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript